Merge tag 'docs-5.8' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
"A fair amount of stuff this time around, dominated by yet another
massive set from Mauro toward the completion of the RST conversion. I
*really* hope we are getting close to the end of this. Meanwhile,
those patches reach pretty far afield to update document references
around the tree; there should be no actual code changes there. There
will be, alas, more of the usual trivial merge conflicts.
Beyond that we have more translations, improvements to the sphinx
scripting, a number of additions to the sysctl documentation, and lots
of fixes"
* tag 'docs-5.8' of git://git.lwn.net/linux: (130 commits)
Documentation: fixes to the maintainer-entry-profile template
zswap: docs/vm: Fix typo accept_threshold_percent in zswap.rst
tracing: Fix events.rst section numbering
docs: acpi: fix old http link and improve document format
docs: filesystems: add info about efivars content
Documentation: LSM: Correct the basic LSM description
mailmap: change email for Ricardo Ribalda
docs: sysctl/kernel: document unaligned controls
Documentation: admin-guide: update bug-hunting.rst
docs: sysctl/kernel: document ngroups_max
nvdimm: fixes to maintainter-entry-profile
Documentation/features: Correct RISC-V kprobes support entry
Documentation/features: Refresh the arch support status files
Revert "docs: sysctl/kernel: document ngroups_max"
docs: move locking-specific documents to locking/
docs: move digsig docs to the security book
docs: move the kref doc into the core-api book
docs: add IRQ documentation at the core-api book
docs: debugging-via-ohci1394.txt: add it to the core-api book
docs: fix references for ipmi.rst file
...
diff --git a/.mailmap b/.mailmap
index 4f906b4..c69d9c7 100644
--- a/.mailmap
+++ b/.mailmap
@@ -152,6 +152,7 @@
Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Leon Romanovsky <leon@kernel.org> <leon@leon.nu>
Leon Romanovsky <leon@kernel.org> <leonro@mellanox.com>
+Leonardo Bras <leobras.c@gmail.com> <leonardo@linux.ibm.com>
Leonid I Ananiev <leonid.i.ananiev@intel.com>
Linas Vepstas <linas@austin.ibm.com>
Linus Lüssing <linus.luessing@c0d3.blue> <linus.luessing@web.de>
@@ -234,7 +235,9 @@
Ralf Wildenhues <Ralf.Wildenhues@gmx.de>
Randy Dunlap <rdunlap@infradead.org> <rdunlap@xenotime.net>
Rémi Denis-Courmont <rdenis@simphalempin.com>
-Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
+Ricardo Ribalda <ribalda@kernel.org> <ricardo.ribalda@gmail.com>
+Ricardo Ribalda <ribalda@kernel.org> <ricardo@ribalda.com>
+Ricardo Ribalda <ribalda@kernel.org> Ricardo Ribalda Delgado <ribalda@kernel.org>
Ross Zwisler <zwisler@kernel.org> <ross.zwisler@linux.intel.com>
Rudolf Marek <R.Marek@sh.cvut.cz>
Rui Saraiva <rmps@joel.ist.utl.pt>
diff --git a/CREDITS b/CREDITS
index 032b599..0787b5872 100644
--- a/CREDITS
+++ b/CREDITS
@@ -3104,14 +3104,16 @@
D: Generic Z8530 driver, AX.25 DAMA slave implementation
D: Several AX.25 hacks
-N: Ricardo Ribalda Delgado
-E: ricardo.ribalda@gmail.com
+N: Ricardo Ribalda
+E: ribalda@kernel.org
W: http://ribalda.com
D: PLX USB338x driver
D: PCA9634 driver
D: Option GTM671WFS
D: Fintek F81216A
D: AD5761 iio driver
+D: TI DAC7612 driver
+D: Sony IMX214 driver
D: Various kernel hacks
S: Qtechnology A/S
S: Valby Langgade 142
diff --git a/Documentation/ABI/stable/sysfs-devices-node b/Documentation/ABI/stable/sysfs-devices-node
index df8413c..484fc04 100644
--- a/Documentation/ABI/stable/sysfs-devices-node
+++ b/Documentation/ABI/stable/sysfs-devices-node
@@ -54,7 +54,7 @@
Contact: Linux Memory Management list <linux-mm@kvack.org>
Description:
Provides information about the node's distribution and memory
- utilization. Similar to /proc/meminfo, see Documentation/filesystems/proc.txt
+ utilization. Similar to /proc/meminfo, see Documentation/filesystems/proc.rst
What: /sys/devices/system/node/nodeX/numastat
Date: October 2002
diff --git a/Documentation/ABI/testing/procfs-smaps_rollup b/Documentation/ABI/testing/procfs-smaps_rollup
index 274df44..0469781 100644
--- a/Documentation/ABI/testing/procfs-smaps_rollup
+++ b/Documentation/ABI/testing/procfs-smaps_rollup
@@ -11,7 +11,7 @@
Additionally, the fields Pss_Anon, Pss_File and Pss_Shmem
are not present in /proc/pid/smaps. These fields represent
the sum of the Pss field of each type (anon, file, shmem).
- For more details, see Documentation/filesystems/proc.txt
+ For more details, see Documentation/filesystems/proc.rst
and the procfs man page.
Typical output looks like this:
diff --git a/Documentation/Makefile b/Documentation/Makefile
index cc786d1..db1fc35 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -98,7 +98,11 @@
pdfdocs: latexdocs
@$(srctree)/scripts/sphinx-pre-install --version-check
- $(foreach var,$(SPHINXDIRS), $(MAKE) PDFLATEX="$(PDFLATEX)" LATEXOPTS="$(LATEXOPTS)" -C $(BUILDDIR)/$(var)/latex || exit;)
+ $(foreach var,$(SPHINXDIRS), \
+ $(MAKE) PDFLATEX="$(PDFLATEX)" LATEXOPTS="$(LATEXOPTS)" -C $(BUILDDIR)/$(var)/latex || exit; \
+ mkdir -p $(BUILDDIR)/$(var)/pdf; \
+ mv $(subst .tex,.pdf,$(wildcard $(BUILDDIR)/$(var)/latex/*.tex)) $(BUILDDIR)/$(var)/pdf/; \
+ )
endif # HAVE_PDFLATEX
diff --git a/Documentation/PCI/boot-interrupts.rst b/Documentation/PCI/boot-interrupts.rst
index d078ef3..2ec7012 100644
--- a/Documentation/PCI/boot-interrupts.rst
+++ b/Documentation/PCI/boot-interrupts.rst
@@ -32,12 +32,13 @@
Spurious Interrupts. The IRQ will be disabled by the Linux kernel after it
reaches a specific count with the error "nobody cared". This disabled IRQ
now prevents valid usage by an existing interrupt which may happen to share
-the IRQ line.
+the IRQ line::
irq 19: nobody cared (try booting with the "irqpoll" option)
CPU: 0 PID: 2988 Comm: irq/34-nipalk Tainted: 4.14.87-rt49-02410-g4a640ec-dirty #1
Hardware name: National Instruments NI PXIe-8880/NI PXIe-8880, BIOS 2.1.5f1 01/09/2020
Call Trace:
+
<IRQ>
? dump_stack+0x46/0x5e
? __report_bad_irq+0x2e/0xb0
@@ -85,15 +86,18 @@
The mitigations take the form of PCI quirks. The preference has been to
first identify and make use of a means to disable the routing to the PCH.
In such a case a quirk to disable boot interrupt generation can be
-added.[1]
+added. [1]_
- Intel® 6300ESB I/O Controller Hub
+Intel® 6300ESB I/O Controller Hub
Alternate Base Address Register:
BIE: Boot Interrupt Enable
- 0 = Boot interrupt is enabled.
- 1 = Boot interrupt is disabled.
- Intel® Sandy Bridge through Sky Lake based Xeon servers:
+ == ===========================
+ 0 Boot interrupt is enabled.
+ 1 Boot interrupt is disabled.
+ == ===========================
+
+Intel® Sandy Bridge through Sky Lake based Xeon servers:
Coherent Interface Protocol Interrupt Control
dis_intx_route2pch/dis_intx_route2ich/dis_intx_route2dmi2:
When this bit is set. Local INTx messages received from the
@@ -109,12 +113,12 @@
disabled, the Linux kernel will reroute the valid interrupt to its legacy
interrupt. This redirection of the handler will prevent the occurrence of
the spurious interrupt detection which would ordinarily disable the IRQ
-line due to excessive unhandled counts.[2]
+line due to excessive unhandled counts. [2]_
The config option X86_REROUTE_FOR_BROKEN_BOOT_IRQS exists to enable (or
disable) the redirection of the interrupt handler to the PCH interrupt
line. The option can be overridden by either pci=ioapicreroute or
-pci=noioapicreroute.[3]
+pci=noioapicreroute. [3]_
More Documentation
@@ -127,19 +131,19 @@
Example of disabling of the boot interrupt
------------------------------------------
-Intel® 6300ESB I/O Controller Hub (Document # 300641-004US)
+ - Intel® 6300ESB I/O Controller Hub (Document # 300641-004US)
5.7.3 Boot Interrupt
https://www.intel.com/content/dam/doc/datasheet/6300esb-io-controller-hub-datasheet.pdf
-Intel® Xeon® Processor E5-1600/2400/2600/4600 v3 Product Families
-Datasheet - Volume 2: Registers (Document # 330784-003)
+ - Intel® Xeon® Processor E5-1600/2400/2600/4600 v3 Product Families
+ Datasheet - Volume 2: Registers (Document # 330784-003)
6.6.41 cipintrc Coherent Interface Protocol Interrupt Control
https://www.intel.com/content/dam/www/public/us/en/documents/datasheets/xeon-e5-v3-datasheet-vol-2.pdf
Example of handler rerouting
----------------------------
-Intel® 6700PXH 64-bit PCI Hub (Document # 302628)
+ - Intel® 6700PXH 64-bit PCI Hub (Document # 302628)
2.15.2 PCI Express Legacy INTx Support and Boot Interrupt
https://www.intel.com/content/dam/doc/datasheet/6700pxh-64-bit-pci-hub-datasheet.pdf
@@ -150,6 +154,6 @@
Sean V Kelley
sean.v.kelley@linux.intel.com
-[1] https://lore.kernel.org/r/12131949181903-git-send-email-sassmann@suse.de/
-[2] https://lore.kernel.org/r/12131949182094-git-send-email-sassmann@suse.de/
-[3] https://lore.kernel.org/r/487C8EA7.6020205@suse.de/
+.. [1] https://lore.kernel.org/r/12131949181903-git-send-email-sassmann@suse.de/
+.. [2] https://lore.kernel.org/r/12131949182094-git-send-email-sassmann@suse.de/
+.. [3] https://lore.kernel.org/r/487C8EA7.6020205@suse.de/
diff --git a/Documentation/admin-guide/acpi/ssdt-overlays.rst b/Documentation/admin-guide/acpi/ssdt-overlays.rst
index da37455..5d7e259 100644
--- a/Documentation/admin-guide/acpi/ssdt-overlays.rst
+++ b/Documentation/admin-guide/acpi/ssdt-overlays.rst
@@ -63,7 +63,7 @@
ASL Input: minnomax.asl - 30 lines, 614 bytes, 7 keywords
AML Output: minnowmax.aml - 165 bytes, 6 named objects, 1 executable opcodes
-[1] http://wiki.minnowboard.org/MinnowBoard_MAX#Low_Speed_Expansion_Connector_.28Top.29
+[1] https://www.elinux.org/Minnowboard:MinnowMax#Low_Speed_Expansion_.28Top.29
The resulting AML code can then be loaded by the kernel using one of the methods
below.
diff --git a/Documentation/admin-guide/bug-hunting.rst b/Documentation/admin-guide/bug-hunting.rst
index 44b8a4e..f7c80f4 100644
--- a/Documentation/admin-guide/bug-hunting.rst
+++ b/Documentation/admin-guide/bug-hunting.rst
@@ -49,15 +49,19 @@
Despite being an **Oops** or some other sort of stack trace, the offended
line is usually required to identify and handle the bug. Along this chapter,
-we'll refer to "Oops" for all kinds of stack traces that need to be analized.
+we'll refer to "Oops" for all kinds of stack traces that need to be analyzed.
-.. note::
+If the kernel is compiled with ``CONFIG_DEBUG_INFO``, you can enhance the
+quality of the stack trace by using file:`scripts/decode_stacktrace.sh`.
- ``ksymoops`` is useless on 2.6 or upper. Please use the Oops in its original
- format (from ``dmesg``, etc). Ignore any references in this or other docs to
- "decoding the Oops" or "running it through ksymoops".
- If you post an Oops from 2.6+ that has been run through ``ksymoops``,
- people will just tell you to repost it.
+Modules linked in
+-----------------
+
+Modules that are tainted or are being loaded or unloaded are marked with
+"(...)", where the taint flags are described in
+file:`Documentation/admin-guide/tainted-kernels.rst`, "being loaded" is
+annotated with "+", and "being unloaded" is annotated with "-".
+
Where is the Oops message is located?
-------------------------------------
@@ -71,7 +75,7 @@
Sometimes ``klogd`` dies, in which case you can run ``dmesg > file`` to
read the data from the kernel buffers and save it. Or you can
``cat /proc/kmsg > file``, however you have to break in to stop the transfer,
-``kmsg`` is a "never ending file".
+since ``kmsg`` is a "never ending file".
If the machine has crashed so badly that you cannot enter commands or
the disk is not available then you have three options:
@@ -81,9 +85,9 @@
planned for a crash. Alternatively, you can take a picture of
the screen with a digital camera - not nice, but better than
nothing. If the messages scroll off the top of the console, you
- may find that booting with a higher resolution (eg, ``vga=791``)
+ may find that booting with a higher resolution (e.g., ``vga=791``)
will allow you to read more of the text. (Caveat: This needs ``vesafb``,
- so won't help for 'early' oopses)
+ so won't help for 'early' oopses.)
(2) Boot with a serial console (see
:ref:`Documentation/admin-guide/serial-console.rst <serial_console>`),
@@ -104,7 +108,7 @@
gdb
^^^
-The GNU debug (``gdb``) is the best way to figure out the exact file and line
+The GNU debugger (``gdb``) is the best way to figure out the exact file and line
number of the OOPS from the ``vmlinux`` file.
The usage of gdb works best on a kernel compiled with ``CONFIG_DEBUG_INFO``.
@@ -165,7 +169,7 @@
[<ffffffff8802770b>] :jbd:journal_stop+0x1be/0x1ee
...
-this shows the problem likely in the :jbd: module. You can load that module
+this shows the problem likely is in the :jbd: module. You can load that module
in gdb and list the relevant code::
$ gdb fs/jbd/jbd.ko
@@ -199,8 +203,9 @@
You need to be at the top level of the kernel tree for this to pick up
your C files.
-If you don't have access to the code you can also debug on some crash dumps
-e.g. crash dump output as shown by Dave Miller::
+If you don't have access to the source code you can still debug some crash
+dumps using the following method (example crash dump output as shown by
+Dave Miller)::
EIP is at +0x14/0x4c0
...
@@ -230,6 +235,9 @@
mov 0x8(%ebp), %ebx ! %ebx = skb->sk
mov 0x13c(%ebx), %eax ! %eax = inet_sk(sk)->opt
+file:`scripts/decodecode` can be used to automate most of this, depending
+on what CPU architecture is being debugged.
+
Reporting the bug
-----------------
@@ -241,7 +249,7 @@
the ``get_maintainer.pl`` script.
For example, if you find a bug at the gspca's sonixj.c file, you can get
-their maintainers with::
+its maintainers with::
$ ./scripts/get_maintainer.pl -f drivers/media/usb/gspca/sonixj.c
Hans Verkuil <hverkuil@xs4all.nl> (odd fixer:GSPCA USB WEBCAM DRIVER,commit_signer:1/1=100%)
@@ -253,16 +261,17 @@
Please notice that it will point to:
-- The last developers that touched on the source code. On the above example,
- Tejun and Bhaktipriya (in this specific case, none really envolved on the
- development of this file);
+- The last developers that touched the source code (if this is done inside
+ a git tree). On the above example, Tejun and Bhaktipriya (in this
+ specific case, none really envolved on the development of this file);
- The driver maintainer (Hans Verkuil);
- The subsystem maintainer (Mauro Carvalho Chehab);
- The driver and/or subsystem mailing list (linux-media@vger.kernel.org);
- the Linux Kernel mailing list (linux-kernel@vger.kernel.org).
Usually, the fastest way to have your bug fixed is to report it to mailing
-list used for the development of the code (linux-media ML) copying the driver maintainer (Hans).
+list used for the development of the code (linux-media ML) copying the
+driver maintainer (Hans).
If you are totally stumped as to whom to send the report, and
``get_maintainer.pl`` didn't provide you anything useful, send it to
@@ -303,9 +312,9 @@
and forwarded to the kernel developers.
Two types of address resolution are performed by ``klogd``. The first is
-static translation and the second is dynamic translation. Static
-translation uses the System.map file in much the same manner that
-ksymoops does. In order to do static translation the ``klogd`` daemon
+static translation and the second is dynamic translation.
+Static translation uses the System.map file.
+In order to do static translation the ``klogd`` daemon
must be able to find a system map file at daemon initialization time.
See the klogd man page for information on how ``klogd`` searches for map
files.
diff --git a/Documentation/admin-guide/cpu-load.rst b/Documentation/admin-guide/cpu-load.rst
index 2d01ce4..ebdecf8 100644
--- a/Documentation/admin-guide/cpu-load.rst
+++ b/Documentation/admin-guide/cpu-load.rst
@@ -105,7 +105,7 @@
----------
- http://lkml.org/lkml/2007/2/12/6
-- Documentation/filesystems/proc.txt (1.8)
+- Documentation/filesystems/proc.rst (1.8)
Thanks
diff --git a/Documentation/admin-guide/hw-vuln/l1tf.rst b/Documentation/admin-guide/hw-vuln/l1tf.rst
index f83212f..3eeeb48 100644
--- a/Documentation/admin-guide/hw-vuln/l1tf.rst
+++ b/Documentation/admin-guide/hw-vuln/l1tf.rst
@@ -268,7 +268,7 @@
/proc/irq/$NR/smp_affinity[_list] files. Limited documentation is
available at:
- https://www.kernel.org/doc/Documentation/IRQ-affinity.txt
+ https://www.kernel.org/doc/Documentation/core-api/irq/irq-affinity.rst
.. _smt_control:
diff --git a/Documentation/admin-guide/init.rst b/Documentation/admin-guide/init.rst
index e89d97f..41f06a0 100644
--- a/Documentation/admin-guide/init.rst
+++ b/Documentation/admin-guide/init.rst
@@ -1,52 +1,48 @@
-Explaining the dreaded "No init found." boot hang message
+Explaining the "No working init found." boot hang message
=========================================================
+:Authors: Andreas Mohr <andi at lisas period de>
+ Cristian Souza <cristianmsbr at gmail period com>
-OK, so you've got this pretty unintuitive message (currently located
-in init/main.c) and are wondering what the H*** went wrong.
-Some high-level reasons for failure (listed roughly in order of execution)
-to load the init binary are:
+This document provides some high-level reasons for failure
+(listed roughly in order of execution) to load the init binary.
-A) Unable to mount root FS
-B) init binary doesn't exist on rootfs
-C) broken console device
-D) binary exists but dependencies not available
-E) binary cannot be loaded
+1) **Unable to mount root FS**: Set "debug" kernel parameter (in bootloader
+ config file or CONFIG_CMDLINE) to get more detailed kernel messages.
-Detailed explanations:
+2) **init binary doesn't exist on rootfs**: Make sure you have the correct
+ root FS type (and ``root=`` kernel parameter points to the correct
+ partition), required drivers such as storage hardware (such as SCSI or
+ USB!) and filesystem (ext3, jffs2, etc.) are builtin (alternatively as
+ modules, to be pre-loaded by an initrd).
-A) Set "debug" kernel parameter (in bootloader config file or CONFIG_CMDLINE)
- to get more detailed kernel messages.
-B) make sure you have the correct root FS type
- (and ``root=`` kernel parameter points to the correct partition),
- required drivers such as storage hardware (such as SCSI or USB!)
- and filesystem (ext3, jffs2 etc.) are builtin (alternatively as modules,
- to be pre-loaded by an initrd)
-C) Possibly a conflict in ``console= setup`` --> initial console unavailable.
- E.g. some serial consoles are unreliable due to serial IRQ issues (e.g.
- missing interrupt-based configuration).
+3) **Broken console device**: Possibly a conflict in ``console= setup``
+ --> initial console unavailable. E.g. some serial consoles are unreliable
+ due to serial IRQ issues (e.g. missing interrupt-based configuration).
Try using a different ``console= device`` or e.g. ``netconsole=``.
-D) e.g. required library dependencies of the init binary such as
- ``/lib/ld-linux.so.2`` missing or broken. Use
- ``readelf -d <INIT>|grep NEEDED`` to find out which libraries are required.
-E) make sure the binary's architecture matches your hardware.
- E.g. i386 vs. x86_64 mismatch, or trying to load x86 on ARM hardware.
- In case you tried loading a non-binary file here (shell script?),
- you should make sure that the script specifies an interpreter in its shebang
- header line (``#!/...``) that is fully working (including its library
- dependencies). And before tackling scripts, better first test a simple
- non-script binary such as ``/bin/sh`` and confirm its successful execution.
- To find out more, add code ``to init/main.c`` to display kernel_execve()s
- return values.
+
+4) **Binary exists but dependencies not available**: E.g. required library
+ dependencies of the init binary such as ``/lib/ld-linux.so.2`` missing or
+ broken. Use ``readelf -d <INIT>|grep NEEDED`` to find out which libraries
+ are required.
+
+5) **Binary cannot be loaded**: Make sure the binary's architecture matches
+ your hardware. E.g. i386 vs. x86_64 mismatch, or trying to load x86 on ARM
+ hardware. In case you tried loading a non-binary file here (shell script?),
+ you should make sure that the script specifies an interpreter in its
+ shebang header line (``#!/...``) that is fully working (including its
+ library dependencies). And before tackling scripts, better first test a
+ simple non-script binary such as ``/bin/sh`` and confirm its successful
+ execution. To find out more, add code ``to init/main.c`` to display
+ kernel_execve()s return values.
Please extend this explanation whenever you find new failure causes
(after all loading the init binary is a CRITICAL and hard transition step
-which needs to be made as painless as possible), then submit patch to LKML.
+which needs to be made as painless as possible), then submit a patch to LKML.
Further TODOs:
- Implement the various ``run_init_process()`` invocations via a struct array
which can then store the ``kernel_execve()`` result value and on failure
log it all by iterating over **all** results (very important usability fix).
-- try to make the implementation itself more helpful in general,
- e.g. by providing additional error messages at affected places.
+- Try to make the implementation itself more helpful in general, e.g. by
+ providing additional error messages at affected places.
-Andreas Mohr <andi at lisas period de>
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 69ff5c4..4379c6a 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -3336,7 +3336,7 @@
See Documentation/admin-guide/sysctl/vm.rst for details.
ohci1394_dma=early [HW] enable debugging via the ohci1394 driver.
- See Documentation/debugging-via-ohci1394.txt for more
+ See Documentation/core-api/debugging-via-ohci1394.rst for more
info.
olpc_ec_timeout= [OLPC] ms delay when issuing EC commands
diff --git a/Documentation/admin-guide/kernel-per-CPU-kthreads.rst b/Documentation/admin-guide/kernel-per-CPU-kthreads.rst
index 21818ac..dc36aeb 100644
--- a/Documentation/admin-guide/kernel-per-CPU-kthreads.rst
+++ b/Documentation/admin-guide/kernel-per-CPU-kthreads.rst
@@ -10,7 +10,7 @@
References
==========
-- Documentation/IRQ-affinity.txt: Binding interrupts to sets of CPUs.
+- Documentation/core-api/irq/irq-affinity.rst: Binding interrupts to sets of CPUs.
- Documentation/admin-guide/cgroup-v1: Using cgroups to bind tasks to sets of CPUs.
diff --git a/Documentation/admin-guide/mm/userfaultfd.rst b/Documentation/admin-guide/mm/userfaultfd.rst
index c30176e..0bf49d7 100644
--- a/Documentation/admin-guide/mm/userfaultfd.rst
+++ b/Documentation/admin-guide/mm/userfaultfd.rst
@@ -12,107 +12,107 @@
memory page faults, something otherwise only the kernel code could do.
For example userfaults allows a proper and more optimal implementation
-of the PROT_NONE+SIGSEGV trick.
+of the ``PROT_NONE+SIGSEGV`` trick.
Design
======
-Userfaults are delivered and resolved through the userfaultfd syscall.
+Userfaults are delivered and resolved through the ``userfaultfd`` syscall.
-The userfaultfd (aside from registering and unregistering virtual
+The ``userfaultfd`` (aside from registering and unregistering virtual
memory ranges) provides two primary functionalities:
-1) read/POLLIN protocol to notify a userland thread of the faults
+1) ``read/POLLIN`` protocol to notify a userland thread of the faults
happening
-2) various UFFDIO_* ioctls that can manage the virtual memory regions
- registered in the userfaultfd that allows userland to efficiently
+2) various ``UFFDIO_*`` ioctls that can manage the virtual memory regions
+ registered in the ``userfaultfd`` that allows userland to efficiently
resolve the userfaults it receives via 1) or to manage the virtual
memory in the background
The real advantage of userfaults if compared to regular virtual memory
management of mremap/mprotect is that the userfaults in all their
operations never involve heavyweight structures like vmas (in fact the
-userfaultfd runtime load never takes the mmap_sem for writing).
+``userfaultfd`` runtime load never takes the mmap_sem for writing).
Vmas are not suitable for page- (or hugepage) granular fault tracking
when dealing with virtual address spaces that could span
Terabytes. Too many vmas would be needed for that.
-The userfaultfd once opened by invoking the syscall, can also be
+The ``userfaultfd`` once opened by invoking the syscall, can also be
passed using unix domain sockets to a manager process, so the same
manager process could handle the userfaults of a multitude of
different processes without them being aware about what is going on
-(well of course unless they later try to use the userfaultfd
+(well of course unless they later try to use the ``userfaultfd``
themselves on the same region the manager is already tracking, which
-is a corner case that would currently return -EBUSY).
+is a corner case that would currently return ``-EBUSY``).
API
===
-When first opened the userfaultfd must be enabled invoking the
-UFFDIO_API ioctl specifying a uffdio_api.api value set to UFFD_API (or
-a later API version) which will specify the read/POLLIN protocol
-userland intends to speak on the UFFD and the uffdio_api.features
-userland requires. The UFFDIO_API ioctl if successful (i.e. if the
-requested uffdio_api.api is spoken also by the running kernel and the
+When first opened the ``userfaultfd`` must be enabled invoking the
+``UFFDIO_API`` ioctl specifying a ``uffdio_api.api`` value set to ``UFFD_API`` (or
+a later API version) which will specify the ``read/POLLIN`` protocol
+userland intends to speak on the ``UFFD`` and the ``uffdio_api.features``
+userland requires. The ``UFFDIO_API`` ioctl if successful (i.e. if the
+requested ``uffdio_api.api`` is spoken also by the running kernel and the
requested features are going to be enabled) will return into
-uffdio_api.features and uffdio_api.ioctls two 64bit bitmasks of
+``uffdio_api.features`` and ``uffdio_api.ioctls`` two 64bit bitmasks of
respectively all the available features of the read(2) protocol and
the generic ioctl available.
-The uffdio_api.features bitmask returned by the UFFDIO_API ioctl
-defines what memory types are supported by the userfaultfd and what
+The ``uffdio_api.features`` bitmask returned by the ``UFFDIO_API`` ioctl
+defines what memory types are supported by the ``userfaultfd`` and what
events, except page fault notifications, may be generated.
-If the kernel supports registering userfaultfd ranges on hugetlbfs
-virtual memory areas, UFFD_FEATURE_MISSING_HUGETLBFS will be set in
-uffdio_api.features. Similarly, UFFD_FEATURE_MISSING_SHMEM will be
-set if the kernel supports registering userfaultfd ranges on shared
-memory (covering all shmem APIs, i.e. tmpfs, IPCSHM, /dev/zero
-MAP_SHARED, memfd_create, etc).
+If the kernel supports registering ``userfaultfd`` ranges on hugetlbfs
+virtual memory areas, ``UFFD_FEATURE_MISSING_HUGETLBFS`` will be set in
+``uffdio_api.features``. Similarly, ``UFFD_FEATURE_MISSING_SHMEM`` will be
+set if the kernel supports registering ``userfaultfd`` ranges on shared
+memory (covering all shmem APIs, i.e. tmpfs, ``IPCSHM``, ``/dev/zero``,
+``MAP_SHARED``, ``memfd_create``, etc).
-The userland application that wants to use userfaultfd with hugetlbfs
+The userland application that wants to use ``userfaultfd`` with hugetlbfs
or shared memory need to set the corresponding flag in
-uffdio_api.features to enable those features.
+``uffdio_api.features`` to enable those features.
If the userland desires to receive notifications for events other than
-page faults, it has to verify that uffdio_api.features has appropriate
-UFFD_FEATURE_EVENT_* bits set. These events are described in more
-detail below in "Non-cooperative userfaultfd" section.
+page faults, it has to verify that ``uffdio_api.features`` has appropriate
+``UFFD_FEATURE_EVENT_*`` bits set. These events are described in more
+detail below in `Non-cooperative userfaultfd`_ section.
-Once the userfaultfd has been enabled the UFFDIO_REGISTER ioctl should
-be invoked (if present in the returned uffdio_api.ioctls bitmask) to
-register a memory range in the userfaultfd by setting the
-uffdio_register structure accordingly. The uffdio_register.mode
+Once the ``userfaultfd`` has been enabled the ``UFFDIO_REGISTER`` ioctl should
+be invoked (if present in the returned ``uffdio_api.ioctls`` bitmask) to
+register a memory range in the ``userfaultfd`` by setting the
+uffdio_register structure accordingly. The ``uffdio_register.mode``
bitmask will specify to the kernel which kind of faults to track for
-the range (UFFDIO_REGISTER_MODE_MISSING would track missing
-pages). The UFFDIO_REGISTER ioctl will return the
-uffdio_register.ioctls bitmask of ioctls that are suitable to resolve
+the range (``UFFDIO_REGISTER_MODE_MISSING`` would track missing
+pages). The ``UFFDIO_REGISTER`` ioctl will return the
+``uffdio_register.ioctls`` bitmask of ioctls that are suitable to resolve
userfaults on the range registered. Not all ioctls will necessarily be
supported for all memory types depending on the underlying virtual
memory backend (anonymous memory vs tmpfs vs real filebacked
mappings).
-Userland can use the uffdio_register.ioctls to manage the virtual
+Userland can use the ``uffdio_register.ioctls`` to manage the virtual
address space in the background (to add or potentially also remove
-memory from the userfaultfd registered range). This means a userfault
+memory from the ``userfaultfd`` registered range). This means a userfault
could be triggering just before userland maps in the background the
user-faulted page.
-The primary ioctl to resolve userfaults is UFFDIO_COPY. That
+The primary ioctl to resolve userfaults is ``UFFDIO_COPY``. That
atomically copies a page into the userfault registered range and wakes
-up the blocked userfaults (unless uffdio_copy.mode &
-UFFDIO_COPY_MODE_DONTWAKE is set). Other ioctl works similarly to
-UFFDIO_COPY. They're atomic as in guaranteeing that nothing can see an
-half copied page since it'll keep userfaulting until the copy has
-finished.
+up the blocked userfaults
+(unless ``uffdio_copy.mode & UFFDIO_COPY_MODE_DONTWAKE`` is set).
+Other ioctl works similarly to ``UFFDIO_COPY``. They're atomic as in
+guaranteeing that nothing can see an half copied page since it'll
+keep userfaulting until the copy has finished.
Notes:
-- If you requested UFFDIO_REGISTER_MODE_MISSING when registering then
+- If you requested ``UFFDIO_REGISTER_MODE_MISSING`` when registering then
you must provide some kind of page in your thread after reading from
- the uffd. You must provide either UFFDIO_COPY or UFFDIO_ZEROPAGE.
+ the uffd. You must provide either ``UFFDIO_COPY`` or ``UFFDIO_ZEROPAGE``.
The normal behavior of the OS automatically providing a zero page on
an annonymous mmaping is not in place.
@@ -122,13 +122,13 @@
- You get the address of the access that triggered the missing page
event out of a struct uffd_msg that you read in the thread from the
- uffd. You can supply as many pages as you want with UFFDIO_COPY or
- UFFDIO_ZEROPAGE. Keep in mind that unless you used DONTWAKE then
+ uffd. You can supply as many pages as you want with ``UFFDIO_COPY`` or
+ ``UFFDIO_ZEROPAGE``. Keep in mind that unless you used DONTWAKE then
the first of any of those IOCTLs wakes up the faulting thread.
-- Be sure to test for all errors including (pollfd[0].revents &
- POLLERR). This can happen, e.g. when ranges supplied were
- incorrect.
+- Be sure to test for all errors including
+ (``pollfd[0].revents & POLLERR``). This can happen, e.g. when ranges
+ supplied were incorrect.
Write Protect Notifications
---------------------------
@@ -136,41 +136,42 @@
This is equivalent to (but faster than) using mprotect and a SIGSEGV
signal handler.
-Firstly you need to register a range with UFFDIO_REGISTER_MODE_WP.
-Instead of using mprotect(2) you use ioctl(uffd, UFFDIO_WRITEPROTECT,
-struct *uffdio_writeprotect) while mode = UFFDIO_WRITEPROTECT_MODE_WP
+Firstly you need to register a range with ``UFFDIO_REGISTER_MODE_WP``.
+Instead of using mprotect(2) you use
+``ioctl(uffd, UFFDIO_WRITEPROTECT, struct *uffdio_writeprotect)``
+while ``mode = UFFDIO_WRITEPROTECT_MODE_WP``
in the struct passed in. The range does not default to and does not
have to be identical to the range you registered with. You can write
protect as many ranges as you like (inside the registered range).
Then, in the thread reading from uffd the struct will have
-msg.arg.pagefault.flags & UFFD_PAGEFAULT_FLAG_WP set. Now you send
-ioctl(uffd, UFFDIO_WRITEPROTECT, struct *uffdio_writeprotect) again
-while pagefault.mode does not have UFFDIO_WRITEPROTECT_MODE_WP set.
-This wakes up the thread which will continue to run with writes. This
+``msg.arg.pagefault.flags & UFFD_PAGEFAULT_FLAG_WP`` set. Now you send
+``ioctl(uffd, UFFDIO_WRITEPROTECT, struct *uffdio_writeprotect)``
+again while ``pagefault.mode`` does not have ``UFFDIO_WRITEPROTECT_MODE_WP``
+set. This wakes up the thread which will continue to run with writes. This
allows you to do the bookkeeping about the write in the uffd reading
thread before the ioctl.
-If you registered with both UFFDIO_REGISTER_MODE_MISSING and
-UFFDIO_REGISTER_MODE_WP then you need to think about the sequence in
+If you registered with both ``UFFDIO_REGISTER_MODE_MISSING`` and
+``UFFDIO_REGISTER_MODE_WP`` then you need to think about the sequence in
which you supply a page and undo write protect. Note that there is a
difference between writes into a WP area and into a !WP area. The
-former will have UFFD_PAGEFAULT_FLAG_WP set, the latter
-UFFD_PAGEFAULT_FLAG_WRITE. The latter did not fail on protection but
-you still need to supply a page when UFFDIO_REGISTER_MODE_MISSING was
+former will have ``UFFD_PAGEFAULT_FLAG_WP`` set, the latter
+``UFFD_PAGEFAULT_FLAG_WRITE``. The latter did not fail on protection but
+you still need to supply a page when ``UFFDIO_REGISTER_MODE_MISSING`` was
used.
QEMU/KVM
========
-QEMU/KVM is using the userfaultfd syscall to implement postcopy live
+QEMU/KVM is using the ``userfaultfd`` syscall to implement postcopy live
migration. Postcopy live migration is one form of memory
externalization consisting of a virtual machine running with part or
all of its memory residing on a different node in the cloud. The
-userfaultfd abstraction is generic enough that not a single line of
+``userfaultfd`` abstraction is generic enough that not a single line of
KVM kernel code had to be modified in order to add postcopy live
migration to QEMU.
-Guest async page faults, FOLL_NOWAIT and all other GUP features work
+Guest async page faults, ``FOLL_NOWAIT`` and all other ``GUP*`` features work
just fine in combination with userfaults. Userfaults trigger async
page faults in the guest scheduler so those guest processes that
aren't waiting for userfaults (i.e. network bound) can keep running in
@@ -183,19 +184,19 @@
The implementation of postcopy live migration currently uses one
single bidirectional socket but in the future two different sockets
will be used (to reduce the latency of the userfaults to the minimum
-possible without having to decrease /proc/sys/net/ipv4/tcp_wmem).
+possible without having to decrease ``/proc/sys/net/ipv4/tcp_wmem``).
The QEMU in the source node writes all pages that it knows are missing
in the destination node, into the socket, and the migration thread of
-the QEMU running in the destination node runs UFFDIO_COPY|ZEROPAGE
-ioctls on the userfaultfd in order to map the received pages into the
-guest (UFFDIO_ZEROCOPY is used if the source page was a zero page).
+the QEMU running in the destination node runs ``UFFDIO_COPY|ZEROPAGE``
+ioctls on the ``userfaultfd`` in order to map the received pages into the
+guest (``UFFDIO_ZEROCOPY`` is used if the source page was a zero page).
A different postcopy thread in the destination node listens with
-poll() to the userfaultfd in parallel. When a POLLIN event is
+poll() to the ``userfaultfd`` in parallel. When a ``POLLIN`` event is
generated after a userfault triggers, the postcopy thread read() from
-the userfaultfd and receives the fault address (or -EAGAIN in case the
-userfault was already resolved and waken by a UFFDIO_COPY|ZEROPAGE run
+the ``userfaultfd`` and receives the fault address (or ``-EAGAIN`` in case the
+userfault was already resolved and waken by a ``UFFDIO_COPY|ZEROPAGE`` run
by the parallel QEMU migration thread).
After the QEMU postcopy thread (running in the destination node) gets
@@ -206,7 +207,7 @@
(just the time to flush the tcp_wmem queue through the network) the
migration thread in the QEMU running in the destination node will
receive the page that triggered the userfault and it'll map it as
-usual with the UFFDIO_COPY|ZEROPAGE (without actually knowing if it
+usual with the ``UFFDIO_COPY|ZEROPAGE`` (without actually knowing if it
was spontaneously sent by the source or if it was an urgent page
requested through a userfault).
@@ -219,74 +220,74 @@
over it when receiving incoming userfaults. After sending each page of
course the bitmap is updated accordingly. It's also useful to avoid
sending the same page twice (in case the userfault is read by the
-postcopy thread just before UFFDIO_COPY|ZEROPAGE runs in the migration
+postcopy thread just before ``UFFDIO_COPY|ZEROPAGE`` runs in the migration
thread).
Non-cooperative userfaultfd
===========================
-When the userfaultfd is monitored by an external manager, the manager
+When the ``userfaultfd`` is monitored by an external manager, the manager
must be able to track changes in the process virtual memory
layout. Userfaultfd can notify the manager about such changes using
the same read(2) protocol as for the page fault notifications. The
manager has to explicitly enable these events by setting appropriate
-bits in uffdio_api.features passed to UFFDIO_API ioctl:
+bits in ``uffdio_api.features`` passed to ``UFFDIO_API`` ioctl:
-UFFD_FEATURE_EVENT_FORK
- enable userfaultfd hooks for fork(). When this feature is
- enabled, the userfaultfd context of the parent process is
+``UFFD_FEATURE_EVENT_FORK``
+ enable ``userfaultfd`` hooks for fork(). When this feature is
+ enabled, the ``userfaultfd`` context of the parent process is
duplicated into the newly created process. The manager
- receives UFFD_EVENT_FORK with file descriptor of the new
- userfaultfd context in the uffd_msg.fork.
+ receives ``UFFD_EVENT_FORK`` with file descriptor of the new
+ ``userfaultfd`` context in the ``uffd_msg.fork``.
-UFFD_FEATURE_EVENT_REMAP
+``UFFD_FEATURE_EVENT_REMAP``
enable notifications about mremap() calls. When the
non-cooperative process moves a virtual memory area to a
different location, the manager will receive
- UFFD_EVENT_REMAP. The uffd_msg.remap will contain the old and
+ ``UFFD_EVENT_REMAP``. The ``uffd_msg.remap`` will contain the old and
new addresses of the area and its original length.
-UFFD_FEATURE_EVENT_REMOVE
+``UFFD_FEATURE_EVENT_REMOVE``
enable notifications about madvise(MADV_REMOVE) and
- madvise(MADV_DONTNEED) calls. The event UFFD_EVENT_REMOVE will
- be generated upon these calls to madvise. The uffd_msg.remove
+ madvise(MADV_DONTNEED) calls. The event ``UFFD_EVENT_REMOVE`` will
+ be generated upon these calls to madvise(). The ``uffd_msg.remove``
will contain start and end addresses of the removed area.
-UFFD_FEATURE_EVENT_UNMAP
+``UFFD_FEATURE_EVENT_UNMAP``
enable notifications about memory unmapping. The manager will
- get UFFD_EVENT_UNMAP with uffd_msg.remove containing start and
+ get ``UFFD_EVENT_UNMAP`` with ``uffd_msg.remove`` containing start and
end addresses of the unmapped area.
-Although the UFFD_FEATURE_EVENT_REMOVE and UFFD_FEATURE_EVENT_UNMAP
+Although the ``UFFD_FEATURE_EVENT_REMOVE`` and ``UFFD_FEATURE_EVENT_UNMAP``
are pretty similar, they quite differ in the action expected from the
-userfaultfd manager. In the former case, the virtual memory is
+``userfaultfd`` manager. In the former case, the virtual memory is
removed, but the area is not, the area remains monitored by the
-userfaultfd, and if a page fault occurs in that area it will be
+``userfaultfd``, and if a page fault occurs in that area it will be
delivered to the manager. The proper resolution for such page fault is
to zeromap the faulting address. However, in the latter case, when an
area is unmapped, either explicitly (with munmap() system call), or
implicitly (e.g. during mremap()), the area is removed and in turn the
-userfaultfd context for such area disappears too and the manager will
+``userfaultfd`` context for such area disappears too and the manager will
not get further userland page faults from the removed area. Still, the
notification is required in order to prevent manager from using
-UFFDIO_COPY on the unmapped area.
+``UFFDIO_COPY`` on the unmapped area.
Unlike userland page faults which have to be synchronous and require
explicit or implicit wakeup, all the events are delivered
asynchronously and the non-cooperative process resumes execution as
-soon as manager executes read(). The userfaultfd manager should
-carefully synchronize calls to UFFDIO_COPY with the events
-processing. To aid the synchronization, the UFFDIO_COPY ioctl will
-return -ENOSPC when the monitored process exits at the time of
-UFFDIO_COPY, and -ENOENT, when the non-cooperative process has changed
-its virtual memory layout simultaneously with outstanding UFFDIO_COPY
+soon as manager executes read(). The ``userfaultfd`` manager should
+carefully synchronize calls to ``UFFDIO_COPY`` with the events
+processing. To aid the synchronization, the ``UFFDIO_COPY`` ioctl will
+return ``-ENOSPC`` when the monitored process exits at the time of
+``UFFDIO_COPY``, and ``-ENOENT``, when the non-cooperative process has changed
+its virtual memory layout simultaneously with outstanding ``UFFDIO_COPY``
operation.
The current asynchronous model of the event delivery is optimal for
-single threaded non-cooperative userfaultfd manager implementations. A
+single threaded non-cooperative ``userfaultfd`` manager implementations. A
synchronous event delivery model can be added later as a new
-userfaultfd feature to facilitate multithreading enhancements of the
-non cooperative manager, for example to allow UFFDIO_COPY ioctls to
+``userfaultfd`` feature to facilitate multithreading enhancements of the
+non cooperative manager, for example to allow ``UFFDIO_COPY`` ioctls to
run in parallel to the event reception. Single threaded
implementations should continue to use the current async event
delivery model instead.
diff --git a/Documentation/admin-guide/nfs/nfsroot.rst b/Documentation/admin-guide/nfs/nfsroot.rst
index 82a4fda..c677207 100644
--- a/Documentation/admin-guide/nfs/nfsroot.rst
+++ b/Documentation/admin-guide/nfs/nfsroot.rst
@@ -18,7 +18,7 @@
In order to use a diskless system, such as an X-terminal or printer server for
example, it is necessary for the root filesystem to be present on a non-disk
device. This may be an initramfs (see
-Documentation/filesystems/ramfs-rootfs-initramfs.txt), a ramdisk (see
+Documentation/filesystems/ramfs-rootfs-initramfs.rst), a ramdisk (see
Documentation/admin-guide/initrd.rst) or a filesystem mounted via NFS. The
following text describes on how to use NFS for the root filesystem. For the rest
of this text 'client' means the diskless system, and 'server' means the NFS
diff --git a/Documentation/admin-guide/numastat.rst b/Documentation/admin-guide/numastat.rst
index aaf1667..08ec2c2 100644
--- a/Documentation/admin-guide/numastat.rst
+++ b/Documentation/admin-guide/numastat.rst
@@ -6,6 +6,21 @@
All units are pages. Hugepages have separate counters.
+The numa_hit, numa_miss and numa_foreign counters reflect how well processes
+are able to allocate memory from nodes they prefer. If they succeed, numa_hit
+is incremented on the preferred node, otherwise numa_foreign is incremented on
+the preferred node and numa_miss on the node where allocation succeeded.
+
+Usually preferred node is the one local to the CPU where the process executes,
+but restrictions such as mempolicies can change that, so there are also two
+counters based on CPU local node. local_node is similar to numa_hit and is
+incremented on allocation from a node by CPU on the same node. other_node is
+similar to numa_miss and is incremented on the node where allocation succeeds
+from a CPU from a different node. Note there is no counter analogical to
+numa_foreign.
+
+In more detail:
+
=============== ============================================================
numa_hit A process wanted to allocate memory from this node,
and succeeded.
@@ -14,11 +29,13 @@
but ended up with memory from this node.
numa_foreign A process wanted to allocate on this node,
- but ended up with memory from another one.
+ but ended up with memory from another node.
-local_node A process ran on this node and got memory from it.
+local_node A process ran on this node's CPU,
+ and got memory from this node.
-other_node A process ran on this node and got memory from another node.
+other_node A process ran on a different node's CPU
+ and got memory from this node.
interleave_hit Interleaving wanted to allocate from this node
and succeeded.
@@ -28,3 +45,11 @@
(http://oss.sgi.com/projects/libnuma/). Note that it only works
well right now on machines with a small number of CPUs.
+Note that on systems with memoryless nodes (where a node has CPUs but no
+memory) the numa_hit, numa_miss and numa_foreign statistics can be skewed
+heavily. In the current kernel implementation, if a process prefers a
+memoryless node (i.e. because it is running on one of its local CPU), the
+implementation actually treats one of the nearest nodes with memory as the
+preferred node. As a result, such allocation will not increase the numa_foreign
+counter on the memoryless node, and will skew the numa_hit, numa_miss and
+numa_foreign statistics of the nearest node.
diff --git a/Documentation/admin-guide/ras.rst b/Documentation/admin-guide/ras.rst
index 0310db6..7b481b2 100644
--- a/Documentation/admin-guide/ras.rst
+++ b/Documentation/admin-guide/ras.rst
@@ -156,11 +156,11 @@
ECC memory
----------
-As mentioned on the previous section, ECC memory has extra bits to be
-used for error correction. So, on 64 bit systems, a memory module
-has 64 bits of *data width*, and 74 bits of *total width*. So, there are
-8 bits extra bits to be used for the error detection and correction
-mechanisms. Those extra bits are called *syndrome*\ [#f1]_\ [#f2]_.
+As mentioned in the previous section, ECC memory has extra bits to be
+used for error correction. In the above example, a memory module has
+64 bits of *data width*, and 72 bits of *total width*. The extra 8
+bits which are used for the error detection and correction mechanisms
+are referred to as the *syndrome*\ [#f1]_\ [#f2]_.
So, when the cpu requests the memory controller to write a word with
*data width*, the memory controller calculates the *syndrome* in real time,
@@ -212,7 +212,7 @@
purposes.
When the subsystem was pushed upstream for the first time, on
- Kernel 2.6.16, for the first time, it was renamed to ``EDAC``.
+ Kernel 2.6.16, it was renamed to ``EDAC``.
Purpose
-------
@@ -351,15 +351,17 @@
+------------+-----------+-----------+
| | ``ch0`` | ``ch1`` |
+============+===========+===========+
- | ``csrow0`` | DIMM_A0 | DIMM_B0 |
- | | rank0 | rank0 |
- +------------+ - | - |
+ | |**DIMM_A0**|**DIMM_B0**|
+ +------------+-----------+-----------+
+ | ``csrow0`` | rank0 | rank0 |
+ +------------+-----------+-----------+
| ``csrow1`` | rank1 | rank1 |
+------------+-----------+-----------+
- | ``csrow2`` | DIMM_A1 | DIMM_B1 |
- | | rank0 | rank0 |
- +------------+ - | - |
- | ``csrow3`` | rank1 | rank1 |
+ | |**DIMM_A1**|**DIMM_B1**|
+ +------------+-----------+-----------+
+ | ``csrow2`` | rank0 | rank0 |
+ +------------+-----------+-----------+
+ | ``csrow3`` | rank1 | rank1 |
+------------+-----------+-----------+
In the above example, there are 4 physical slots on the motherboard
diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index 8d25892..1ebf68d 100644
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -102,6 +102,30 @@
:doc:`/x86/boot` for additional information.
+bpf_stats_enabled
+=================
+
+Controls whether the kernel should collect statistics on BPF programs
+(total time spent running, number of times run...). Enabling
+statistics causes a slight reduction in performance on each program
+run. The statistics can be seen using ``bpftool``.
+
+= ===================================
+0 Don't collect statistics (default).
+1 Collect statistics.
+= ===================================
+
+
+cad_pid
+=======
+
+This is the pid which will be signalled on reboot (notably, by
+Ctrl-Alt-Delete). Writing a value to this file which doesn't
+correspond to a running process will result in ``-ESRCH``.
+
+See also `ctrl-alt-del`_.
+
+
cap_last_cap
============
@@ -241,6 +265,40 @@
see the ``hostname(1)`` man page.
+firmware_config
+===============
+
+See :doc:`/driver-api/firmware/fallback-mechanisms`.
+
+The entries in this directory allow the firmware loader helper
+fallback to be controlled:
+
+* ``force_sysfs_fallback``, when set to 1, forces the use of the
+ fallback;
+* ``ignore_sysfs_fallback``, when set to 1, ignores any fallback.
+
+
+ftrace_dump_on_oops
+===================
+
+Determines whether ``ftrace_dump()`` should be called on an oops (or
+kernel panic). This will output the contents of the ftrace buffers to
+the console. This is very useful for capturing traces that lead to
+crashes and outputting them to a serial console.
+
+= ===================================================
+0 Disabled (default).
+1 Dump buffers of all CPUs.
+2 Dump the buffer of the CPU that triggered the oops.
+= ===================================================
+
+
+ftrace_enabled, stack_tracer_enabled
+====================================
+
+See :doc:`/trace/ftrace`.
+
+
hardlockup_all_cpu_backtrace
============================
@@ -344,6 +402,25 @@
= =========================================================
+ignore-unaligned-usertrap
+=========================
+
+On architectures where unaligned accesses cause traps, and where this
+feature is supported (``CONFIG_SYSCTL_ARCH_UNALIGN_NO_WARN``;
+currently, ``arc`` and ``ia64``), controls whether all unaligned traps
+are logged.
+
+= =============================================================
+0 Log all unaligned accesses.
+1 Only warn the first time a process traps. This is the default
+ setting.
+= =============================================================
+
+See also `unaligned-trap`_ and `unaligned-dump-stack`_. On ``ia64``,
+this allows system administrators to override the
+``IA64_THREAD_UAC_NOPRINT`` ``prctl`` and avoid logs being flooded.
+
+
kexec_load_disabled
===================
@@ -459,6 +536,15 @@
successful IPC object allocation. If an IPC object allocation syscall
fails, it is undefined if the value remains unmodified or is reset to -1.
+
+ngroups_max
+===========
+
+Maximum number of supplementary groups, _i.e._ the maximum size which
+``setgroups`` will accept. Exports ``NGROUPS_MAX`` from the kernel.
+
+
+
nmi_watchdog
============
@@ -877,7 +963,7 @@
pty
===
-See Documentation/filesystems/devpts.txt.
+See Documentation/filesystems/devpts.rst.
randomize_va_space
@@ -1173,6 +1259,65 @@
``EINVAL`` error occurs.
+traceoff_on_warning
+===================
+
+When set, disables tracing (see :doc:`/trace/ftrace`) when a
+``WARN()`` is hit.
+
+
+tracepoint_printk
+=================
+
+When tracepoints are sent to printk() (enabled by the ``tp_printk``
+boot parameter), this entry provides runtime control::
+
+ echo 0 > /proc/sys/kernel/tracepoint_printk
+
+will stop tracepoints from being sent to printk(), and::
+
+ echo 1 > /proc/sys/kernel/tracepoint_printk
+
+will send them to printk() again.
+
+This only works if the kernel was booted with ``tp_printk`` enabled.
+
+See :doc:`/admin-guide/kernel-parameters` and
+:doc:`/trace/boottime-trace`.
+
+
+.. _unaligned-dump-stack:
+
+unaligned-dump-stack (ia64)
+===========================
+
+When logging unaligned accesses, controls whether the stack is
+dumped.
+
+= ===================================================
+0 Do not dump the stack. This is the default setting.
+1 Dump the stack.
+= ===================================================
+
+See also `ignore-unaligned-usertrap`_.
+
+
+unaligned-trap
+==============
+
+On architectures where unaligned accesses cause traps, and where this
+feature is supported (``CONFIG_SYSCTL_ARCH_UNALIGN_ALLOW``; currently,
+``arc`` and ``parisc``), controls whether unaligned traps are caught
+and emulated (instead of failing).
+
+= ========================================================
+0 Do not emulate unaligned accesses.
+1 Emulate unaligned accesses. This is the default setting.
+= ========================================================
+
+See also `ignore-unaligned-usertrap`_.
+
+
unknown_nmi_panic
=================
@@ -1184,6 +1329,16 @@
example. If a system hangs up, try pressing the NMI switch.
+unprivileged_bpf_disabled
+=========================
+
+Writing 1 to this entry will disable unprivileged calls to ``bpf()``;
+once disabled, calling ``bpf()`` without ``CAP_SYS_ADMIN`` will return
+``-EPERM``.
+
+Once set, this can't be cleared.
+
+
watchdog
========
diff --git a/Documentation/arm64/amu.rst b/Documentation/arm64/amu.rst
index 036783e..452ec8b 100644
--- a/Documentation/arm64/amu.rst
+++ b/Documentation/arm64/amu.rst
@@ -24,13 +24,13 @@
Version 1 of the Activity Monitors architecture implements a counter group
of four fixed and architecturally defined 64-bit event counters.
-- CPU cycle counter: increments at the frequency of the CPU.
-- Constant counter: increments at the fixed frequency of the system
- clock.
-- Instructions retired: increments with every architecturally executed
- instruction.
-- Memory stall cycles: counts instruction dispatch stall cycles caused by
- misses in the last level cache within the clock domain.
+ - CPU cycle counter: increments at the frequency of the CPU.
+ - Constant counter: increments at the fixed frequency of the system
+ clock.
+ - Instructions retired: increments with every architecturally executed
+ instruction.
+ - Memory stall cycles: counts instruction dispatch stall cycles caused by
+ misses in the last level cache within the clock domain.
When in WFI or WFE these counters do not increment.
@@ -59,11 +59,11 @@
Firmware (code running at higher exception levels, e.g. arm-tf) support is
needed to:
-- Enable access for lower exception levels (EL2 and EL1) to the AMU
- registers.
-- Enable the counters. If not enabled these will read as 0.
-- Save/restore the counters before/after the CPU is being put/brought up
- from the 'off' power state.
+ - Enable access for lower exception levels (EL2 and EL1) to the AMU
+ registers.
+ - Enable the counters. If not enabled these will read as 0.
+ - Save/restore the counters before/after the CPU is being put/brought up
+ from the 'off' power state.
When using kernels that have this feature enabled but boot with broken
firmware the user may experience panics or lockups when accessing the
@@ -81,10 +81,10 @@
The fixed counters of AMUv1 are accessible though the following system
register definitions:
-- SYS_AMEVCNTR0_CORE_EL0
-- SYS_AMEVCNTR0_CONST_EL0
-- SYS_AMEVCNTR0_INST_RET_EL0
-- SYS_AMEVCNTR0_MEM_STALL_EL0
+ - SYS_AMEVCNTR0_CORE_EL0
+ - SYS_AMEVCNTR0_CONST_EL0
+ - SYS_AMEVCNTR0_INST_RET_EL0
+ - SYS_AMEVCNTR0_MEM_STALL_EL0
Auxiliary platform specific counters can be accessed using
SYS_AMEVCNTR1_EL0(n), where n is a value between 0 and 15.
@@ -97,9 +97,9 @@
Currently, access from userspace to the AMU registers is disabled due to:
-- Security reasons: they might expose information about code executed in
- secure mode.
-- Purpose: AMU counters are intended for system management use.
+ - Security reasons: they might expose information about code executed in
+ secure mode.
+ - Purpose: AMU counters are intended for system management use.
Also, the presence of the feature is not visible to userspace.
@@ -110,8 +110,8 @@
Currently, access from userspace (EL0) and kernelspace (EL1) on the KVM
guest side is disabled due to:
-- Security reasons: they might expose information about code executed
- by other guests or the host.
+ - Security reasons: they might expose information about code executed
+ by other guests or the host.
Any attempt to access the AMU registers will result in an UNDEFINED
exception being injected into the guest.
diff --git a/Documentation/arm64/booting.rst b/Documentation/arm64/booting.rst
index d063c05d..7552dbc 100644
--- a/Documentation/arm64/booting.rst
+++ b/Documentation/arm64/booting.rst
@@ -173,8 +173,10 @@
- Caches, MMUs
The MMU must be off.
+
The instruction cache may be on or off, and must not hold any stale
entries corresponding to the loaded kernel image.
+
The address range corresponding to the loaded kernel image must be
cleaned to the PoC. In the presence of a system cache or other
coherent masters with caches enabled, this will typically require
@@ -239,6 +241,7 @@
- The DT or ACPI tables must describe a GICv2 interrupt controller.
For CPUs with pointer authentication functionality:
+
- If EL3 is present:
- SCR_EL3.APK (bit 16) must be initialised to 0b1
@@ -250,18 +253,22 @@
- HCR_EL2.API (bit 41) must be initialised to 0b1
For CPUs with Activity Monitors Unit v1 (AMUv1) extension present:
+
- If EL3 is present:
- CPTR_EL3.TAM (bit 30) must be initialised to 0b0
- CPTR_EL2.TAM (bit 30) must be initialised to 0b0
- AMCNTENSET0_EL0 must be initialised to 0b1111
- AMCNTENSET1_EL0 must be initialised to a platform specific value
- having 0b1 set for the corresponding bit for each of the auxiliary
- counters present.
+
+ - CPTR_EL3.TAM (bit 30) must be initialised to 0b0
+ - CPTR_EL2.TAM (bit 30) must be initialised to 0b0
+ - AMCNTENSET0_EL0 must be initialised to 0b1111
+ - AMCNTENSET1_EL0 must be initialised to a platform specific value
+ having 0b1 set for the corresponding bit for each of the auxiliary
+ counters present.
+
- If the kernel is entered at EL1:
- AMCNTENSET0_EL0 must be initialised to 0b1111
- AMCNTENSET1_EL0 must be initialised to a platform specific value
- having 0b1 set for the corresponding bit for each of the auxiliary
- counters present.
+
+ - AMCNTENSET0_EL0 must be initialised to 0b1111
+ - AMCNTENSET1_EL0 must be initialised to a platform specific value
+ having 0b1 set for the corresponding bit for each of the auxiliary
+ counters present.
The requirements described above for CPU mode, caches, MMUs, architected
timers, coherency and system registers apply to all CPUs. All CPUs must
@@ -305,7 +312,8 @@
Documentation/devicetree/bindings/arm/psci.yaml.
- Secondary CPU general-purpose register settings
- x0 = 0 (reserved for future use)
- x1 = 0 (reserved for future use)
- x2 = 0 (reserved for future use)
- x3 = 0 (reserved for future use)
+
+ - x0 = 0 (reserved for future use)
+ - x1 = 0 (reserved for future use)
+ - x2 = 0 (reserved for future use)
+ - x3 = 0 (reserved for future use)
diff --git a/Documentation/conf.py b/Documentation/conf.py
index 9ae8e9a..f6a1bc0 100644
--- a/Documentation/conf.py
+++ b/Documentation/conf.py
@@ -388,44 +388,6 @@
# author, documentclass [howto, manual, or own class]).
# Sorted in alphabetical order
latex_documents = [
- ('admin-guide/index', 'linux-user.tex', 'Linux Kernel User Documentation',
- 'The kernel development community', 'manual'),
- ('core-api/index', 'core-api.tex', 'The kernel core API manual',
- 'The kernel development community', 'manual'),
- ('crypto/index', 'crypto-api.tex', 'Linux Kernel Crypto API manual',
- 'The kernel development community', 'manual'),
- ('dev-tools/index', 'dev-tools.tex', 'Development tools for the Kernel',
- 'The kernel development community', 'manual'),
- ('doc-guide/index', 'kernel-doc-guide.tex', 'Linux Kernel Documentation Guide',
- 'The kernel development community', 'manual'),
- ('driver-api/index', 'driver-api.tex', 'The kernel driver API manual',
- 'The kernel development community', 'manual'),
- ('filesystems/index', 'filesystems.tex', 'Linux Filesystems API',
- 'The kernel development community', 'manual'),
- ('admin-guide/ext4', 'ext4-admin-guide.tex', 'ext4 Administration Guide',
- 'ext4 Community', 'manual'),
- ('filesystems/ext4/index', 'ext4-data-structures.tex',
- 'ext4 Data Structures and Algorithms', 'ext4 Community', 'manual'),
- ('gpu/index', 'gpu.tex', 'Linux GPU Driver Developer\'s Guide',
- 'The kernel development community', 'manual'),
- ('input/index', 'linux-input.tex', 'The Linux input driver subsystem',
- 'The kernel development community', 'manual'),
- ('kernel-hacking/index', 'kernel-hacking.tex', 'Unreliable Guide To Hacking The Linux Kernel',
- 'The kernel development community', 'manual'),
- ('media/index', 'media.tex', 'Linux Media Subsystem Documentation',
- 'The kernel development community', 'manual'),
- ('networking/index', 'networking.tex', 'Linux Networking Documentation',
- 'The kernel development community', 'manual'),
- ('process/index', 'development-process.tex', 'Linux Kernel Development Documentation',
- 'The kernel development community', 'manual'),
- ('security/index', 'security.tex', 'The kernel security subsystem manual',
- 'The kernel development community', 'manual'),
- ('sh/index', 'sh.tex', 'SuperH architecture implementation manual',
- 'The kernel development community', 'manual'),
- ('sound/index', 'sound.tex', 'Linux Sound Subsystem Documentation',
- 'The kernel development community', 'manual'),
- ('userspace-api/index', 'userspace-api.tex', 'The Linux kernel user-space API guide',
- 'The kernel development community', 'manual'),
]
# Add all other index files from Documentation/ subdirectories
diff --git a/Documentation/debugging-via-ohci1394.txt b/Documentation/core-api/debugging-via-ohci1394.rst
similarity index 100%
rename from Documentation/debugging-via-ohci1394.txt
rename to Documentation/core-api/debugging-via-ohci1394.rst
diff --git a/Documentation/DMA-API-HOWTO.txt b/Documentation/core-api/dma-api-howto.rst
similarity index 100%
rename from Documentation/DMA-API-HOWTO.txt
rename to Documentation/core-api/dma-api-howto.rst
diff --git a/Documentation/DMA-API.txt b/Documentation/core-api/dma-api.rst
similarity index 100%
rename from Documentation/DMA-API.txt
rename to Documentation/core-api/dma-api.rst
diff --git a/Documentation/DMA-attributes.txt b/Documentation/core-api/dma-attributes.rst
similarity index 100%
rename from Documentation/DMA-attributes.txt
rename to Documentation/core-api/dma-attributes.rst
diff --git a/Documentation/DMA-ISA-LPC.txt b/Documentation/core-api/dma-isa-lpc.rst
similarity index 100%
rename from Documentation/DMA-ISA-LPC.txt
rename to Documentation/core-api/dma-isa-lpc.rst
diff --git a/Documentation/core-api/index.rst b/Documentation/core-api/index.rst
index 0897ad1..15ab861 100644
--- a/Documentation/core-api/index.rst
+++ b/Documentation/core-api/index.rst
@@ -18,6 +18,7 @@
kernel-api
workqueue
+ printk-basics
printk-formats
symbol-namespaces
@@ -30,10 +31,12 @@
:maxdepth: 1
kobject
+ kref
assoc_array
xarray
idr
circular-buffers
+ rbtree
generic-radix-tree
packing
timekeeping
@@ -50,6 +53,7 @@
atomic_ops
refcount-vs-atomic
+ irq/index
local_ops
padata
../RCU/index
@@ -78,6 +82,10 @@
:maxdepth: 1
memory-allocation
+ dma-api
+ dma-api-howto
+ dma-attributes
+ dma-isa-lpc
mm-api
genalloc
pin_user_pages
@@ -92,6 +100,7 @@
debug-objects
tracepoint
+ debugging-via-ohci1394
Everything else
===============
diff --git a/Documentation/IRQ.txt b/Documentation/core-api/irq/concepts.rst
similarity index 100%
rename from Documentation/IRQ.txt
rename to Documentation/core-api/irq/concepts.rst
diff --git a/Documentation/core-api/irq/index.rst b/Documentation/core-api/irq/index.rst
new file mode 100644
index 0000000..0d65d11
--- /dev/null
+++ b/Documentation/core-api/irq/index.rst
@@ -0,0 +1,11 @@
+====
+IRQs
+====
+
+.. toctree::
+ :maxdepth: 1
+
+ concepts
+ irq-affinity
+ irq-domain
+ irqflags-tracing
diff --git a/Documentation/IRQ-affinity.txt b/Documentation/core-api/irq/irq-affinity.rst
similarity index 100%
rename from Documentation/IRQ-affinity.txt
rename to Documentation/core-api/irq/irq-affinity.rst
diff --git a/Documentation/IRQ-domain.txt b/Documentation/core-api/irq/irq-domain.rst
similarity index 98%
rename from Documentation/IRQ-domain.txt
rename to Documentation/core-api/irq/irq-domain.rst
index 507775c..096db12 100644
--- a/Documentation/IRQ-domain.txt
+++ b/Documentation/core-api/irq/irq-domain.rst
@@ -263,7 +263,8 @@
Hierarchy irq_domain is in no way x86 specific, and is heavily used to
support other architectures, such as ARM, ARM64 etc.
-=== Debugging ===
+Debugging
+=========
Most of the internals of the IRQ subsystem are exposed in debugfs by
turning CONFIG_GENERIC_IRQ_DEBUGFS on.
diff --git a/Documentation/irqflags-tracing.txt b/Documentation/core-api/irq/irqflags-tracing.rst
similarity index 100%
rename from Documentation/irqflags-tracing.txt
rename to Documentation/core-api/irq/irqflags-tracing.rst
diff --git a/Documentation/core-api/kobject.rst b/Documentation/core-api/kobject.rst
index 1f62d4d..e93dc8c 100644
--- a/Documentation/core-api/kobject.rst
+++ b/Documentation/core-api/kobject.rst
@@ -80,11 +80,11 @@
(such as assuming that the kobject is at the beginning of the structure)
and, instead, use the container_of() macro, found in ``<linux/kernel.h>``::
- container_of(pointer, type, member)
+ container_of(ptr, type, member)
where:
- * ``pointer`` is the pointer to the embedded kobject,
+ * ``ptr`` is the pointer to the embedded kobject,
* ``type`` is the type of the containing structure, and
* ``member`` is the name of the structure field to which ``pointer`` points.
@@ -140,7 +140,7 @@
int kobject_rename(struct kobject *kobj, const char *new_name);
-kobject_rename does not perform any locking or have a solid notion of
+kobject_rename() does not perform any locking or have a solid notion of
what names are valid so the caller must provide their own sanity checking
and serialization.
@@ -210,7 +210,7 @@
If all that you want to use a kobject for is to provide a reference counter
for your structure, please use the struct kref instead; a kobject would be
overkill. For more information on how to use struct kref, please see the
-file Documentation/kref.txt in the Linux kernel source tree.
+file Documentation/core-api/kref.rst in the Linux kernel source tree.
Creating "simple" kobjects
@@ -222,17 +222,17 @@
exception where a single kobject should be created. To create such an
entry, use the function::
- struct kobject *kobject_create_and_add(char *name, struct kobject *parent);
+ struct kobject *kobject_create_and_add(const char *name, struct kobject *parent);
This function will create a kobject and place it in sysfs in the location
underneath the specified parent kobject. To create simple attributes
associated with this kobject, use::
- int sysfs_create_file(struct kobject *kobj, struct attribute *attr);
+ int sysfs_create_file(struct kobject *kobj, const struct attribute *attr);
or::
- int sysfs_create_group(struct kobject *kobj, struct attribute_group *grp);
+ int sysfs_create_group(struct kobject *kobj, const struct attribute_group *grp);
Both types of attributes used here, with a kobject that has been created
with the kobject_create_and_add(), can be of type kobj_attribute, so no
@@ -300,8 +300,10 @@
void (*release)(struct kobject *kobj);
const struct sysfs_ops *sysfs_ops;
struct attribute **default_attrs;
+ const struct attribute_group **default_groups;
const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);
const void *(*namespace)(struct kobject *kobj);
+ void (*get_ownership)(struct kobject *kobj, kuid_t *uid, kgid_t *gid);
};
This structure is used to describe a particular type of kobject (or, more
@@ -352,12 +354,12 @@
kset use::
struct kset *kset_create_and_add(const char *name,
- struct kset_uevent_ops *u,
- struct kobject *parent);
+ const struct kset_uevent_ops *uevent_ops,
+ struct kobject *parent_kobj);
When you are finished with the kset, call::
- void kset_unregister(struct kset *kset);
+ void kset_unregister(struct kset *k);
to destroy it. This removes the kset from sysfs and decrements its reference
count. When the reference count goes to zero, the kset will be released.
@@ -371,9 +373,9 @@
associated with it, it can use the struct kset_uevent_ops to handle it::
struct kset_uevent_ops {
- int (*filter)(struct kset *kset, struct kobject *kobj);
- const char *(*name)(struct kset *kset, struct kobject *kobj);
- int (*uevent)(struct kset *kset, struct kobject *kobj,
+ int (* const filter)(struct kset *kset, struct kobject *kobj);
+ const char *(* const name)(struct kset *kset, struct kobject *kobj);
+ int (* const uevent)(struct kset *kset, struct kobject *kobj,
struct kobj_uevent_env *env);
};
diff --git a/Documentation/kref.txt b/Documentation/core-api/kref.rst
similarity index 100%
rename from Documentation/kref.txt
rename to Documentation/core-api/kref.rst
diff --git a/Documentation/core-api/printk-basics.rst b/Documentation/core-api/printk-basics.rst
new file mode 100644
index 0000000..563a9ce
--- /dev/null
+++ b/Documentation/core-api/printk-basics.rst
@@ -0,0 +1,115 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===========================
+Message logging with printk
+===========================
+
+printk() is one of the most widely known functions in the Linux kernel. It's the
+standard tool we have for printing messages and usually the most basic way of
+tracing and debugging. If you're familiar with printf(3) you can tell printk()
+is based on it, although it has some functional differences:
+
+ - printk() messages can specify a log level.
+
+ - the format string, while largely compatible with C99, doesn't follow the
+ exact same specification. It has some extensions and a few limitations
+ (no ``%n`` or floating point conversion specifiers). See :ref:`How to get
+ printk format specifiers right <printk-specifiers>`.
+
+All printk() messages are printed to the kernel log buffer, which is a ring
+buffer exported to userspace through /dev/kmsg. The usual way to read it is
+using ``dmesg``.
+
+printk() is typically used like this::
+
+ printk(KERN_INFO "Message: %s\n", arg);
+
+where ``KERN_INFO`` is the log level (note that it's concatenated to the format
+string, the log level is not a separate argument). The available log levels are:
+
++----------------+--------+-----------------------------------------------+
+| Name | String | Alias function |
++================+========+===============================================+
+| KERN_EMERG | "0" | pr_emerg() |
++----------------+--------+-----------------------------------------------+
+| KERN_ALERT | "1" | pr_alert() |
++----------------+--------+-----------------------------------------------+
+| KERN_CRIT | "2" | pr_crit() |
++----------------+--------+-----------------------------------------------+
+| KERN_ERR | "3" | pr_err() |
++----------------+--------+-----------------------------------------------+
+| KERN_WARNING | "4" | pr_warn() |
++----------------+--------+-----------------------------------------------+
+| KERN_NOTICE | "5" | pr_notice() |
++----------------+--------+-----------------------------------------------+
+| KERN_INFO | "6" | pr_info() |
++----------------+--------+-----------------------------------------------+
+| KERN_DEBUG | "7" | pr_debug() and pr_devel() if DEBUG is defined |
++----------------+--------+-----------------------------------------------+
+| KERN_DEFAULT | "" | |
++----------------+--------+-----------------------------------------------+
+| KERN_CONT | "c" | pr_cont() |
++----------------+--------+-----------------------------------------------+
+
+
+The log level specifies the importance of a message. The kernel decides whether
+to show the message immediately (printing it to the current console) depending
+on its log level and the current *console_loglevel* (a kernel variable). If the
+message priority is higher (lower log level value) than the *console_loglevel*
+the message will be printed to the console.
+
+If the log level is omitted, the message is printed with ``KERN_DEFAULT``
+level.
+
+You can check the current *console_loglevel* with::
+
+ $ cat /proc/sys/kernel/printk
+ 4 4 1 7
+
+The result shows the *current*, *default*, *minimum* and *boot-time-default* log
+levels.
+
+To change the current console_loglevel simply write the the desired level to
+``/proc/sys/kernel/printk``. For example, to print all messages to the console::
+
+ # echo 8 > /proc/sys/kernel/printk
+
+Another way, using ``dmesg``::
+
+ # dmesg -n 5
+
+sets the console_loglevel to print KERN_WARNING (4) or more severe messages to
+console. See ``dmesg(1)`` for more information.
+
+As an alternative to printk() you can use the ``pr_*()`` aliases for
+logging. This family of macros embed the log level in the macro names. For
+example::
+
+ pr_info("Info message no. %d\n", msg_num);
+
+prints a ``KERN_INFO`` message.
+
+Besides being more concise than the equivalent printk() calls, they can use a
+common definition for the format string through the pr_fmt() macro. For
+instance, defining this at the top of a source file (before any ``#include``
+directive)::
+
+ #define pr_fmt(fmt) "%s:%s: " fmt, KBUILD_MODNAME, __func__
+
+would prefix every pr_*() message in that file with the module and function name
+that originated the message.
+
+For debugging purposes there are also two conditionally-compiled macros:
+pr_debug() and pr_devel(), which are compiled-out unless ``DEBUG`` (or
+also ``CONFIG_DYNAMIC_DEBUG`` in the case of pr_debug()) is defined.
+
+
+Function reference
+==================
+
+.. kernel-doc:: kernel/printk/printk.c
+ :functions: printk
+
+.. kernel-doc:: include/linux/printk.h
+ :functions: pr_emerg pr_alert pr_crit pr_err pr_warn pr_notice pr_info
+ pr_fmt pr_debug pr_devel pr_cont
diff --git a/Documentation/core-api/printk-formats.rst b/Documentation/core-api/printk-formats.rst
index 5d8f1e8..8c9aba2 100644
--- a/Documentation/core-api/printk-formats.rst
+++ b/Documentation/core-api/printk-formats.rst
@@ -2,6 +2,8 @@
How to get printk format specifiers right
=========================================
+.. _printk-specifiers:
+
:Author: Randy Dunlap <rdunlap@infradead.org>
:Author: Andrew Murray <amurray@mpc-data.co.uk>
diff --git a/Documentation/rbtree.txt b/Documentation/core-api/rbtree.rst
similarity index 100%
rename from Documentation/rbtree.txt
rename to Documentation/core-api/rbtree.rst
diff --git a/Documentation/doc-guide/maintainer-profile.rst b/Documentation/doc-guide/maintainer-profile.rst
index 5afc0dd..755d39f 100644
--- a/Documentation/doc-guide/maintainer-profile.rst
+++ b/Documentation/doc-guide/maintainer-profile.rst
@@ -6,7 +6,7 @@
The documentation "subsystem" is the central coordinating point for the
kernel's documentation and associated infrastructure. It covers the
hierarchy under Documentation/ (with the exception of
-Documentation/device-tree), various utilities under scripts/ and, at least
+Documentation/devicetree), various utilities under scripts/ and, at least
some of the time, LICENSES/.
It's worth noting, though, that the boundaries of this subsystem are rather
diff --git a/Documentation/driver-api/dma-buf.rst b/Documentation/driver-api/dma-buf.rst
index c78db28..63dec76 100644
--- a/Documentation/driver-api/dma-buf.rst
+++ b/Documentation/driver-api/dma-buf.rst
@@ -11,7 +11,7 @@
The three main components of this are: (1) dma-buf, representing a
sg_table and exposed to userspace as a file descriptor to allow passing
between devices, (2) fence, which provides a mechanism to signal when
-one device as finished access, and (3) reservation, which manages the
+one device has finished access, and (3) reservation, which manages the
shared or exclusive fence(s) associated with the buffer.
Shared DMA Buffers
@@ -31,7 +31,7 @@
- implements and manages operations in :c:type:`struct dma_buf_ops
<dma_buf_ops>` for the buffer,
- allows other users to share the buffer by using dma_buf sharing APIs,
- - manages the details of buffer allocation, wrapped int a :c:type:`struct
+ - manages the details of buffer allocation, wrapped in a :c:type:`struct
dma_buf <dma_buf>`,
- decides about the actual backing storage where this allocation happens,
- and takes care of any migration of scatterlist - for all (shared) users of
diff --git a/Documentation/driver-api/driver-model/device.rst b/Documentation/driver-api/driver-model/device.rst
index 2b868d4..b9b0223 100644
--- a/Documentation/driver-api/driver-model/device.rst
+++ b/Documentation/driver-api/driver-model/device.rst
@@ -50,10 +50,10 @@
Attributes of devices can be exported by a device driver through sysfs.
-Please see Documentation/filesystems/sysfs.txt for more information
+Please see Documentation/filesystems/sysfs.rst for more information
on how sysfs works.
-As explained in Documentation/kobject.txt, device attributes must be
+As explained in Documentation/core-api/kobject.rst, device attributes must be
created before the KOBJ_ADD uevent is generated. The only way to realize
that is by defining an attribute group.
diff --git a/Documentation/driver-api/driver-model/overview.rst b/Documentation/driver-api/driver-model/overview.rst
index d4d1e9b..e98d0ab 100644
--- a/Documentation/driver-api/driver-model/overview.rst
+++ b/Documentation/driver-api/driver-model/overview.rst
@@ -121,4 +121,4 @@
More information about the sysfs directory layout can be found in
the other documents in this directory and in the file
-Documentation/filesystems/sysfs.txt.
+Documentation/filesystems/sysfs.rst.
diff --git a/Documentation/driver-api/index.rst b/Documentation/driver-api/index.rst
index d4e78cb..20c431c 100644
--- a/Documentation/driver-api/index.rst
+++ b/Documentation/driver-api/index.rst
@@ -39,6 +39,7 @@
spi
i2c
ipmb
+ ipmi
i3c/index
interconnect
devfreq
diff --git a/Documentation/IPMI.txt b/Documentation/driver-api/ipmi.rst
similarity index 100%
rename from Documentation/IPMI.txt
rename to Documentation/driver-api/ipmi.rst
diff --git a/Documentation/driver-api/nvdimm/nvdimm.rst b/Documentation/driver-api/nvdimm/nvdimm.rst
index 08f855c..79c0fd3 100644
--- a/Documentation/driver-api/nvdimm/nvdimm.rst
+++ b/Documentation/driver-api/nvdimm/nvdimm.rst
@@ -278,8 +278,8 @@
be contiguous in DPA-space.
This bus is provided by the kernel under the device
- /sys/devices/platform/nfit_test.0 when CONFIG_NFIT_TEST is enabled and
- the nfit_test.ko module is loaded. This not only test LIBNVDIMM but the
+ /sys/devices/platform/nfit_test.0 when the nfit_test.ko module from
+ tools/testing/nvdimm is loaded. This not only test LIBNVDIMM but the
acpi_nfit.ko driver as well.
diff --git a/Documentation/driver-api/thermal/cpu-idle-cooling.rst b/Documentation/driver-api/thermal/cpu-idle-cooling.rst
index a1c3ede..b9f34ce 100644
--- a/Documentation/driver-api/thermal/cpu-idle-cooling.rst
+++ b/Documentation/driver-api/thermal/cpu-idle-cooling.rst
@@ -1,3 +1,6 @@
+================
+CPU Idle Cooling
+================
Situation:
----------
diff --git a/Documentation/driver-api/thermal/index.rst b/Documentation/driver-api/thermal/index.rst
index 5ba61d1..4cb0b9b 100644
--- a/Documentation/driver-api/thermal/index.rst
+++ b/Documentation/driver-api/thermal/index.rst
@@ -8,6 +8,7 @@
:maxdepth: 1
cpu-cooling-api
+ cpu-idle-cooling
sysfs-api
power_allocator
diff --git a/Documentation/features/core/eBPF-JIT/arch-support.txt b/Documentation/features/core/eBPF-JIT/arch-support.txt
index 9ae6e8d..9ed964f 100644
--- a/Documentation/features/core/eBPF-JIT/arch-support.txt
+++ b/Documentation/features/core/eBPF-JIT/arch-support.txt
@@ -23,7 +23,7 @@
| openrisc: | TODO |
| parisc: | TODO |
| powerpc: | ok |
- | riscv: | TODO |
+ | riscv: | ok |
| s390: | ok |
| sh: | TODO |
| sparc: | ok |
diff --git a/Documentation/features/debug/KASAN/arch-support.txt b/Documentation/features/debug/KASAN/arch-support.txt
index 304dcd4..6ff3854 100644
--- a/Documentation/features/debug/KASAN/arch-support.txt
+++ b/Documentation/features/debug/KASAN/arch-support.txt
@@ -22,9 +22,9 @@
| nios2: | TODO |
| openrisc: | TODO |
| parisc: | TODO |
- | powerpc: | TODO |
- | riscv: | TODO |
- | s390: | TODO |
+ | powerpc: | ok |
+ | riscv: | ok |
+ | s390: | ok |
| sh: | TODO |
| sparc: | TODO |
| um: | TODO |
diff --git a/Documentation/features/debug/gcov-profile-all/arch-support.txt b/Documentation/features/debug/gcov-profile-all/arch-support.txt
index 6fb2b06..210256f 100644
--- a/Documentation/features/debug/gcov-profile-all/arch-support.txt
+++ b/Documentation/features/debug/gcov-profile-all/arch-support.txt
@@ -11,7 +11,7 @@
| arm: | ok |
| arm64: | ok |
| c6x: | TODO |
- | csky: | TODO |
+ | csky: | ok |
| h8300: | TODO |
| hexagon: | TODO |
| ia64: | TODO |
diff --git a/Documentation/features/debug/kprobes-on-ftrace/arch-support.txt b/Documentation/features/debug/kprobes-on-ftrace/arch-support.txt
index 32b2972..97cd7aa 100644
--- a/Documentation/features/debug/kprobes-on-ftrace/arch-support.txt
+++ b/Documentation/features/debug/kprobes-on-ftrace/arch-support.txt
@@ -11,7 +11,7 @@
| arm: | TODO |
| arm64: | TODO |
| c6x: | TODO |
- | csky: | TODO |
+ | csky: | ok |
| h8300: | TODO |
| hexagon: | TODO |
| ia64: | TODO |
diff --git a/Documentation/features/debug/kprobes/arch-support.txt b/Documentation/features/debug/kprobes/arch-support.txt
index e68239b..8b316c6 100644
--- a/Documentation/features/debug/kprobes/arch-support.txt
+++ b/Documentation/features/debug/kprobes/arch-support.txt
@@ -11,7 +11,7 @@
| arm: | ok |
| arm64: | ok |
| c6x: | TODO |
- | csky: | TODO |
+ | csky: | ok |
| h8300: | TODO |
| hexagon: | TODO |
| ia64: | ok |
@@ -23,7 +23,7 @@
| openrisc: | TODO |
| parisc: | ok |
| powerpc: | ok |
- | riscv: | ok |
+ | riscv: | TODO |
| s390: | ok |
| sh: | ok |
| sparc: | ok |
diff --git a/Documentation/features/debug/kretprobes/arch-support.txt b/Documentation/features/debug/kretprobes/arch-support.txt
index f17131b..b805aad 100644
--- a/Documentation/features/debug/kretprobes/arch-support.txt
+++ b/Documentation/features/debug/kretprobes/arch-support.txt
@@ -11,7 +11,7 @@
| arm: | ok |
| arm64: | ok |
| c6x: | TODO |
- | csky: | TODO |
+ | csky: | ok |
| h8300: | TODO |
| hexagon: | TODO |
| ia64: | ok |
diff --git a/Documentation/features/debug/stackprotector/arch-support.txt b/Documentation/features/debug/stackprotector/arch-support.txt
index 32bbdfc..12410f6 100644
--- a/Documentation/features/debug/stackprotector/arch-support.txt
+++ b/Documentation/features/debug/stackprotector/arch-support.txt
@@ -11,7 +11,7 @@
| arm: | ok |
| arm64: | ok |
| c6x: | TODO |
- | csky: | TODO |
+ | csky: | ok |
| h8300: | TODO |
| hexagon: | TODO |
| ia64: | TODO |
diff --git a/Documentation/features/debug/uprobes/arch-support.txt b/Documentation/features/debug/uprobes/arch-support.txt
index 1c577d0..be8acbb 100644
--- a/Documentation/features/debug/uprobes/arch-support.txt
+++ b/Documentation/features/debug/uprobes/arch-support.txt
@@ -11,7 +11,7 @@
| arm: | ok |
| arm64: | ok |
| c6x: | TODO |
- | csky: | TODO |
+ | csky: | ok |
| h8300: | TODO |
| hexagon: | TODO |
| ia64: | TODO |
diff --git a/Documentation/features/io/dma-contiguous/arch-support.txt b/Documentation/features/io/dma-contiguous/arch-support.txt
index eb28b5c..895c3b0 100644
--- a/Documentation/features/io/dma-contiguous/arch-support.txt
+++ b/Documentation/features/io/dma-contiguous/arch-support.txt
@@ -16,7 +16,7 @@
| hexagon: | TODO |
| ia64: | TODO |
| m68k: | TODO |
- | microblaze: | TODO |
+ | microblaze: | ok |
| mips: | ok |
| nds32: | TODO |
| nios2: | TODO |
diff --git a/Documentation/features/locking/lockdep/arch-support.txt b/Documentation/features/locking/lockdep/arch-support.txt
index 941fd5b..98cb9d8 100644
--- a/Documentation/features/locking/lockdep/arch-support.txt
+++ b/Documentation/features/locking/lockdep/arch-support.txt
@@ -11,7 +11,7 @@
| arm: | ok |
| arm64: | ok |
| c6x: | TODO |
- | csky: | TODO |
+ | csky: | ok |
| h8300: | TODO |
| hexagon: | ok |
| ia64: | TODO |
diff --git a/Documentation/features/perf/kprobes-event/arch-support.txt b/Documentation/features/perf/kprobes-event/arch-support.txt
index d8278bf..518f352 100644
--- a/Documentation/features/perf/kprobes-event/arch-support.txt
+++ b/Documentation/features/perf/kprobes-event/arch-support.txt
@@ -11,7 +11,7 @@
| arm: | ok |
| arm64: | ok |
| c6x: | TODO |
- | csky: | TODO |
+ | csky: | ok |
| h8300: | TODO |
| hexagon: | ok |
| ia64: | TODO |
@@ -21,7 +21,7 @@
| nds32: | ok |
| nios2: | TODO |
| openrisc: | TODO |
- | parisc: | TODO |
+ | parisc: | ok |
| powerpc: | ok |
| riscv: | TODO |
| s390: | ok |
diff --git a/Documentation/features/perf/perf-regs/arch-support.txt b/Documentation/features/perf/perf-regs/arch-support.txt
index 687d049..c22cd6f 100644
--- a/Documentation/features/perf/perf-regs/arch-support.txt
+++ b/Documentation/features/perf/perf-regs/arch-support.txt
@@ -11,7 +11,7 @@
| arm: | ok |
| arm64: | ok |
| c6x: | TODO |
- | csky: | TODO |
+ | csky: | ok |
| h8300: | TODO |
| hexagon: | TODO |
| ia64: | TODO |
@@ -23,7 +23,7 @@
| openrisc: | TODO |
| parisc: | TODO |
| powerpc: | ok |
- | riscv: | TODO |
+ | riscv: | ok |
| s390: | ok |
| sh: | TODO |
| sparc: | TODO |
diff --git a/Documentation/features/perf/perf-stackdump/arch-support.txt b/Documentation/features/perf/perf-stackdump/arch-support.txt
index 90996e3..527fe4d 100644
--- a/Documentation/features/perf/perf-stackdump/arch-support.txt
+++ b/Documentation/features/perf/perf-stackdump/arch-support.txt
@@ -11,7 +11,7 @@
| arm: | ok |
| arm64: | ok |
| c6x: | TODO |
- | csky: | TODO |
+ | csky: | ok |
| h8300: | TODO |
| hexagon: | TODO |
| ia64: | TODO |
@@ -23,7 +23,7 @@
| openrisc: | TODO |
| parisc: | TODO |
| powerpc: | ok |
- | riscv: | TODO |
+ | riscv: | ok |
| s390: | ok |
| sh: | TODO |
| sparc: | TODO |
diff --git a/Documentation/features/seccomp/seccomp-filter/arch-support.txt b/Documentation/features/seccomp/seccomp-filter/arch-support.txt
index 4fe6c3c..c7b837f 100644
--- a/Documentation/features/seccomp/seccomp-filter/arch-support.txt
+++ b/Documentation/features/seccomp/seccomp-filter/arch-support.txt
@@ -23,7 +23,7 @@
| openrisc: | TODO |
| parisc: | ok |
| powerpc: | ok |
- | riscv: | TODO |
+ | riscv: | ok |
| s390: | ok |
| sh: | TODO |
| sparc: | TODO |
diff --git a/Documentation/features/vm/huge-vmap/arch-support.txt b/Documentation/features/vm/huge-vmap/arch-support.txt
index 019131c..8525f19 100644
--- a/Documentation/features/vm/huge-vmap/arch-support.txt
+++ b/Documentation/features/vm/huge-vmap/arch-support.txt
@@ -22,7 +22,7 @@
| nios2: | TODO |
| openrisc: | TODO |
| parisc: | TODO |
- | powerpc: | TODO |
+ | powerpc: | ok |
| riscv: | TODO |
| s390: | TODO |
| sh: | TODO |
diff --git a/Documentation/features/vm/pte_special/arch-support.txt b/Documentation/features/vm/pte_special/arch-support.txt
index 3d492a3..2e01738 100644
--- a/Documentation/features/vm/pte_special/arch-support.txt
+++ b/Documentation/features/vm/pte_special/arch-support.txt
@@ -17,7 +17,7 @@
| ia64: | TODO |
| m68k: | TODO |
| microblaze: | TODO |
- | mips: | TODO |
+ | mips: | ok |
| nds32: | TODO |
| nios2: | TODO |
| openrisc: | TODO |
diff --git a/Documentation/filesystems/9p.rst b/Documentation/filesystems/9p.rst
index 671fef3..2995279 100644
--- a/Documentation/filesystems/9p.rst
+++ b/Documentation/filesystems/9p.rst
@@ -192,4 +192,4 @@
http://plan9.bell-labs.com/plan9
For information on Plan 9 from User Space (Plan 9 applications and libraries
-ported to Linux/BSD/OSX/etc) check out http://swtch.com/plan9
+ported to Linux/BSD/OSX/etc) check out https://9fans.github.io/plan9port/
diff --git a/Documentation/filesystems/automount-support.txt b/Documentation/filesystems/automount-support.rst
similarity index 91%
rename from Documentation/filesystems/automount-support.txt
rename to Documentation/filesystems/automount-support.rst
index 7d9f826..430f0b4 100644
--- a/Documentation/filesystems/automount-support.txt
+++ b/Documentation/filesystems/automount-support.rst
@@ -1,3 +1,10 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=================
+Automount Support
+=================
+
+
Support is available for filesystems that wish to do automounting
support (such as kAFS which can be found in fs/afs/ and NFS in
fs/nfs/). This facility includes allowing in-kernel mounts to be
@@ -5,13 +12,12 @@
also be requested by userspace.
-======================
-IN-KERNEL AUTOMOUNTING
+In-Kernel Automounting
======================
See section "Mount Traps" of Documentation/filesystems/autofs.rst
-Then from userspace, you can just do something like:
+Then from userspace, you can just do something like::
[root@andromeda root]# mount -t afs \#root.afs. /afs
[root@andromeda root]# ls /afs
@@ -21,7 +27,7 @@
[root@andromeda root]# ls /afs/cambridge/afsdoc/
ChangeLog html LICENSE pdf RELNOTES-1.2.2
-And then if you look in the mountpoint catalogue, you'll see something like:
+And then if you look in the mountpoint catalogue, you'll see something like::
[root@andromeda root]# cat /proc/mounts
...
@@ -30,8 +36,7 @@
#afsdoc. /afs/cambridge.redhat.com/afsdoc afs rw 0 0
-===========================
-AUTOMATIC MOUNTPOINT EXPIRY
+Automatic Mountpoint Expiry
===========================
Automatic expiration of mountpoints is easy, provided you've mounted the
@@ -43,7 +48,8 @@
hung.
(2) When a new mountpoint is created in the ->d_automount method, add
- the mnt to the list using mnt_set_expiry()
+ the mnt to the list using mnt_set_expiry()::
+
mnt_set_expiry(newmnt, &afs_vfsmounts);
(3) When you want mountpoints to be expired, call mark_mounts_for_expiry()
@@ -70,8 +76,7 @@
same expiration list.
-=======================
-USERSPACE DRIVEN EXPIRY
+Userspace Driven Expiry
=======================
As an alternative, it is possible for userspace to request expiry of any
diff --git a/Documentation/filesystems/caching/backend-api.txt b/Documentation/filesystems/caching/backend-api.rst
similarity index 87%
rename from Documentation/filesystems/caching/backend-api.txt
rename to Documentation/filesystems/caching/backend-api.rst
index c418280..19fbf6b 100644
--- a/Documentation/filesystems/caching/backend-api.txt
+++ b/Documentation/filesystems/caching/backend-api.rst
@@ -1,6 +1,8 @@
- ==========================
- FS-CACHE CACHE BACKEND API
- ==========================
+.. SPDX-License-Identifier: GPL-2.0
+
+==========================
+FS-Cache Cache backend API
+==========================
The FS-Cache system provides an API by which actual caches can be supplied to
FS-Cache for it to then serve out to network filesystems and other interested
@@ -9,15 +11,14 @@
This API is declared in <linux/fscache-cache.h>.
-====================================
-INITIALISING AND REGISTERING A CACHE
+Initialising and Registering a Cache
====================================
To start off, a cache definition must be initialised and registered for each
cache the backend wants to make available. For instance, CacheFS does this in
the fill_super() operation on mounting.
-The cache definition (struct fscache_cache) should be initialised by calling:
+The cache definition (struct fscache_cache) should be initialised by calling::
void fscache_init_cache(struct fscache_cache *cache,
struct fscache_cache_ops *ops,
@@ -26,17 +27,17 @@
Where:
- (*) "cache" is a pointer to the cache definition;
+ * "cache" is a pointer to the cache definition;
- (*) "ops" is a pointer to the table of operations that the backend supports on
+ * "ops" is a pointer to the table of operations that the backend supports on
this cache; and
- (*) "idfmt" is a format and printf-style arguments for constructing a label
+ * "idfmt" is a format and printf-style arguments for constructing a label
for the cache.
The cache should then be registered with FS-Cache by passing a pointer to the
-previously initialised cache definition to:
+previously initialised cache definition to::
int fscache_add_cache(struct fscache_cache *cache,
struct fscache_object *fsdef,
@@ -44,12 +45,12 @@
Two extra arguments should also be supplied:
- (*) "fsdef" which should point to the object representation for the FS-Cache
+ * "fsdef" which should point to the object representation for the FS-Cache
master index in this cache. Netfs primary index entries will be created
here. FS-Cache keeps the caller's reference to the index object if
successful and will release it upon withdrawal of the cache.
- (*) "tagname" which, if given, should be a text string naming this cache. If
+ * "tagname" which, if given, should be a text string naming this cache. If
this is NULL, the identifier will be used instead. For CacheFS, the
identifier is set to name the underlying block device and the tag can be
supplied by mount.
@@ -58,20 +59,18 @@
is already in use. 0 will be returned on success.
-=====================
-UNREGISTERING A CACHE
+Unregistering a Cache
=====================
A cache can be withdrawn from the system by calling this function with a
-pointer to the cache definition:
+pointer to the cache definition::
void fscache_withdraw_cache(struct fscache_cache *cache);
In CacheFS's case, this is called by put_super().
-========
-SECURITY
+Security
========
The cache methods are executed one of two contexts:
@@ -89,8 +88,7 @@
This is left to the cache to handle; FS-Cache makes no effort in this regard.
-===================================
-CONTROL AND STATISTICS PRESENTATION
+Control and Statistics Presentation
===================================
The cache may present data to the outside world through FS-Cache's interfaces
@@ -101,11 +99,10 @@
and is for use by the cache as it sees fit.
-========================
-RELEVANT DATA STRUCTURES
+Relevant Data Structures
========================
- (*) Index/Data file FS-Cache representation cookie:
+ * Index/Data file FS-Cache representation cookie::
struct fscache_cookie {
struct fscache_object_def *def;
@@ -121,7 +118,7 @@
cache operations.
- (*) In-cache object representation:
+ * In-cache object representation::
struct fscache_object {
int debug_id;
@@ -150,7 +147,7 @@
initialised by calling fscache_object_init(object).
- (*) FS-Cache operation record:
+ * FS-Cache operation record::
struct fscache_operation {
atomic_t usage;
@@ -173,7 +170,7 @@
an operation needs more processing time, it should be enqueued again.
- (*) FS-Cache retrieval operation record:
+ * FS-Cache retrieval operation record::
struct fscache_retrieval {
struct fscache_operation op;
@@ -198,7 +195,7 @@
it sees fit.
- (*) FS-Cache storage operation record:
+ * FS-Cache storage operation record::
struct fscache_storage {
struct fscache_operation op;
@@ -212,16 +209,17 @@
storage.
-================
-CACHE OPERATIONS
+Cache Operations
================
The cache backend provides FS-Cache with a table of operations that can be
performed on the denizens of the cache. These are held in a structure of type:
- struct fscache_cache_ops
+ ::
- (*) Name of cache provider [mandatory]:
+ struct fscache_cache_ops
+
+ * Name of cache provider [mandatory]::
const char *name
@@ -229,7 +227,7 @@
the backend.
- (*) Allocate a new object [mandatory]:
+ * Allocate a new object [mandatory]::
struct fscache_object *(*alloc_object)(struct fscache_cache *cache,
struct fscache_cookie *cookie)
@@ -244,7 +242,7 @@
form once lookup is complete or aborted.
- (*) Look up and create object [mandatory]:
+ * Look up and create object [mandatory]::
void (*lookup_object)(struct fscache_object *object)
@@ -263,7 +261,7 @@
to abort the lookup of that object.
- (*) Release lookup data [mandatory]:
+ * Release lookup data [mandatory]::
void (*lookup_complete)(struct fscache_object *object)
@@ -271,7 +269,7 @@
using to perform a lookup.
- (*) Increment object refcount [mandatory]:
+ * Increment object refcount [mandatory]::
struct fscache_object *(*grab_object)(struct fscache_object *object)
@@ -280,7 +278,7 @@
It should return the object pointer if successful.
- (*) Lock/Unlock object [mandatory]:
+ * Lock/Unlock object [mandatory]::
void (*lock_object)(struct fscache_object *object)
void (*unlock_object)(struct fscache_object *object)
@@ -289,7 +287,7 @@
to schedule with the lock held, so a spinlock isn't sufficient.
- (*) Pin/Unpin object [optional]:
+ * Pin/Unpin object [optional]::
int (*pin_object)(struct fscache_object *object)
void (*unpin_object)(struct fscache_object *object)
@@ -299,7 +297,7 @@
enough space in the cache to permit this.
- (*) Check coherency state of an object [mandatory]:
+ * Check coherency state of an object [mandatory]::
int (*check_consistency)(struct fscache_object *object)
@@ -308,7 +306,7 @@
if they're consistent and -ESTALE otherwise. -ENOMEM and -ERESTARTSYS
may also be returned.
- (*) Update object [mandatory]:
+ * Update object [mandatory]::
int (*update_object)(struct fscache_object *object)
@@ -317,7 +315,7 @@
obtained by calling object->cookie->def->get_aux()/get_attr().
- (*) Invalidate data object [mandatory]:
+ * Invalidate data object [mandatory]::
int (*invalidate_object)(struct fscache_operation *op)
@@ -329,7 +327,7 @@
fscache_op_complete() must be called on op before returning.
- (*) Discard object [mandatory]:
+ * Discard object [mandatory]::
void (*drop_object)(struct fscache_object *object)
@@ -341,7 +339,7 @@
caller. The caller will invoke the put_object() method as appropriate.
- (*) Release object reference [mandatory]:
+ * Release object reference [mandatory]::
void (*put_object)(struct fscache_object *object)
@@ -349,7 +347,7 @@
be freed when all the references to it are released.
- (*) Synchronise a cache [mandatory]:
+ * Synchronise a cache [mandatory]::
void (*sync)(struct fscache_cache *cache)
@@ -357,7 +355,7 @@
device.
- (*) Dissociate a cache [mandatory]:
+ * Dissociate a cache [mandatory]::
void (*dissociate_pages)(struct fscache_cache *cache)
@@ -365,7 +363,7 @@
cache withdrawal.
- (*) Notification that the attributes on a netfs file changed [mandatory]:
+ * Notification that the attributes on a netfs file changed [mandatory]::
int (*attr_changed)(struct fscache_object *object);
@@ -386,7 +384,7 @@
execution of this operation.
- (*) Reserve cache space for an object's data [optional]:
+ * Reserve cache space for an object's data [optional]::
int (*reserve_space)(struct fscache_object *object, loff_t size);
@@ -404,7 +402,7 @@
size if larger than that already.
- (*) Request page be read from cache [mandatory]:
+ * Request page be read from cache [mandatory]::
int (*read_or_alloc_page)(struct fscache_retrieval *op,
struct page *page,
@@ -446,7 +444,7 @@
with. This will complete the operation when all pages are dealt with.
- (*) Request pages be read from cache [mandatory]:
+ * Request pages be read from cache [mandatory]::
int (*read_or_alloc_pages)(struct fscache_retrieval *op,
struct list_head *pages,
@@ -457,7 +455,7 @@
of pages instead of one page. Any pages on which a read operation is
started must be added to the page cache for the specified mapping and also
to the LRU. Such pages must also be removed from the pages list and
- *nr_pages decremented per page.
+ ``*nr_pages`` decremented per page.
If there was an error such as -ENOMEM, then that should be returned; else
if one or more pages couldn't be read or allocated, then -ENOBUFS should
@@ -466,7 +464,7 @@
returned.
- (*) Request page be allocated in the cache [mandatory]:
+ * Request page be allocated in the cache [mandatory]::
int (*allocate_page)(struct fscache_retrieval *op,
struct page *page,
@@ -482,7 +480,7 @@
allocated, then the netfs page should be marked and 0 returned.
- (*) Request pages be allocated in the cache [mandatory]:
+ * Request pages be allocated in the cache [mandatory]::
int (*allocate_pages)(struct fscache_retrieval *op,
struct list_head *pages,
@@ -493,7 +491,7 @@
nr_pages should be treated as for the read_or_alloc_pages() method.
- (*) Request page be written to cache [mandatory]:
+ * Request page be written to cache [mandatory]::
int (*write_page)(struct fscache_storage *op,
struct page *page);
@@ -514,7 +512,7 @@
appropriately.
- (*) Discard retained per-page metadata [mandatory]:
+ * Discard retained per-page metadata [mandatory]::
void (*uncache_page)(struct fscache_object *object, struct page *page)
@@ -523,13 +521,12 @@
maintains for this page.
-==================
-FS-CACHE UTILITIES
+FS-Cache Utilities
==================
FS-Cache provides some utilities that a cache backend may make use of:
- (*) Note occurrence of an I/O error in a cache:
+ * Note occurrence of an I/O error in a cache::
void fscache_io_error(struct fscache_cache *cache)
@@ -541,7 +538,7 @@
This does not actually withdraw the cache. That must be done separately.
- (*) Invoke the retrieval I/O completion function:
+ * Invoke the retrieval I/O completion function::
void fscache_end_io(struct fscache_retrieval *op, struct page *page,
int error);
@@ -550,8 +547,8 @@
error value should be 0 if successful and an error otherwise.
- (*) Record that one or more pages being retrieved or allocated have been dealt
- with:
+ * Record that one or more pages being retrieved or allocated have been dealt
+ with::
void fscache_retrieval_complete(struct fscache_retrieval *op,
int n_pages);
@@ -562,7 +559,7 @@
completed.
- (*) Record operation completion:
+ * Record operation completion::
void fscache_op_complete(struct fscache_operation *op);
@@ -571,7 +568,7 @@
one or more pending operations to start running.
- (*) Set highest store limit:
+ * Set highest store limit::
void fscache_set_store_limit(struct fscache_object *object,
loff_t i_size);
@@ -581,7 +578,7 @@
rejected by fscache_read_alloc_page() and co with -ENOBUFS.
- (*) Mark pages as being cached:
+ * Mark pages as being cached::
void fscache_mark_pages_cached(struct fscache_retrieval *op,
struct pagevec *pagevec);
@@ -590,7 +587,7 @@
the netfs must call fscache_uncache_page() to unmark the pages.
- (*) Perform coherency check on an object:
+ * Perform coherency check on an object::
enum fscache_checkaux fscache_check_aux(struct fscache_object *object,
const void *data,
@@ -603,29 +600,26 @@
One of three values will be returned:
- (*) FSCACHE_CHECKAUX_OKAY
-
+ FSCACHE_CHECKAUX_OKAY
The coherency data indicates the object is valid as is.
- (*) FSCACHE_CHECKAUX_NEEDS_UPDATE
-
+ FSCACHE_CHECKAUX_NEEDS_UPDATE
The coherency data needs updating, but otherwise the object is
valid.
- (*) FSCACHE_CHECKAUX_OBSOLETE
-
+ FSCACHE_CHECKAUX_OBSOLETE
The coherency data indicates that the object is obsolete and should
be discarded.
- (*) Initialise a freshly allocated object:
+ * Initialise a freshly allocated object::
void fscache_object_init(struct fscache_object *object);
This initialises all the fields in an object representation.
- (*) Indicate the destruction of an object:
+ * Indicate the destruction of an object::
void fscache_object_destroyed(struct fscache_cache *cache);
@@ -635,7 +629,7 @@
all the objects.
- (*) Indicate negative lookup on an object:
+ * Indicate negative lookup on an object::
void fscache_object_lookup_negative(struct fscache_object *object);
@@ -650,7 +644,7 @@
significant - all subsequent calls are ignored.
- (*) Indicate an object has been obtained:
+ * Indicate an object has been obtained::
void fscache_obtained_object(struct fscache_object *object);
@@ -667,7 +661,7 @@
(2) that writes may now proceed against this object.
- (*) Indicate that object lookup failed:
+ * Indicate that object lookup failed::
void fscache_object_lookup_error(struct fscache_object *object);
@@ -676,7 +670,7 @@
as possible.
- (*) Indicate that a stale object was found and discarded:
+ * Indicate that a stale object was found and discarded::
void fscache_object_retrying_stale(struct fscache_object *object);
@@ -685,7 +679,7 @@
discarded from the cache and the lookup will be performed again.
- (*) Indicate that the caching backend killed an object:
+ * Indicate that the caching backend killed an object::
void fscache_object_mark_killed(struct fscache_object *object,
enum fscache_why_object_killed why);
@@ -693,13 +687,20 @@
This is called to indicate that the cache backend preemptively killed an
object. The why parameter should be set to indicate the reason:
- FSCACHE_OBJECT_IS_STALE - the object was stale and needs discarding.
- FSCACHE_OBJECT_NO_SPACE - there was insufficient cache space
- FSCACHE_OBJECT_WAS_RETIRED - the object was retired when relinquished.
- FSCACHE_OBJECT_WAS_CULLED - the object was culled to make space.
+ FSCACHE_OBJECT_IS_STALE
+ - the object was stale and needs discarding.
+
+ FSCACHE_OBJECT_NO_SPACE
+ - there was insufficient cache space
+
+ FSCACHE_OBJECT_WAS_RETIRED
+ - the object was retired when relinquished.
+
+ FSCACHE_OBJECT_WAS_CULLED
+ - the object was culled to make space.
- (*) Get and release references on a retrieval record:
+ * Get and release references on a retrieval record::
void fscache_get_retrieval(struct fscache_retrieval *op);
void fscache_put_retrieval(struct fscache_retrieval *op);
@@ -708,7 +709,7 @@
asynchronous data retrieval and block allocation.
- (*) Enqueue a retrieval record for processing.
+ * Enqueue a retrieval record for processing::
void fscache_enqueue_retrieval(struct fscache_retrieval *op);
@@ -718,7 +719,7 @@
within the callback function.
- (*) List of object state names:
+ * List of object state names::
const char *fscache_object_states[];
diff --git a/Documentation/filesystems/caching/cachefiles.txt b/Documentation/filesystems/caching/cachefiles.rst
similarity index 89%
rename from Documentation/filesystems/caching/cachefiles.txt
rename to Documentation/filesystems/caching/cachefiles.rst
index 28aefcb..65d3db4 100644
--- a/Documentation/filesystems/caching/cachefiles.txt
+++ b/Documentation/filesystems/caching/cachefiles.rst
@@ -1,8 +1,10 @@
- ===============================================
- CacheFiles: CACHE ON ALREADY MOUNTED FILESYSTEM
- ===============================================
+.. SPDX-License-Identifier: GPL-2.0
-Contents:
+===============================================
+CacheFiles: CACHE ON ALREADY MOUNTED FILESYSTEM
+===============================================
+
+.. Contents:
(*) Overview.
@@ -27,8 +29,8 @@
(*) Debugging.
-========
-OVERVIEW
+
+Overview
========
CacheFiles is a caching backend that's meant to use as a cache a directory on
@@ -58,8 +60,8 @@
space.
-============
-REQUIREMENTS
+
+Requirements
============
The use of CacheFiles and its daemon requires the following features to be
@@ -79,84 +81,70 @@
filesystems being used as a cache.
-=============
-CONFIGURATION
+Configuration
=============
The cache is configured by a script in /etc/cachefilesd.conf. These commands
set up cache ready for use. The following script commands are available:
- (*) brun <N>%
- (*) bcull <N>%
- (*) bstop <N>%
- (*) frun <N>%
- (*) fcull <N>%
- (*) fstop <N>%
-
+ brun <N>%, bcull <N>%, bstop <N>%, frun <N>%, fcull <N>%, fstop <N>%
Configure the culling limits. Optional. See the section on culling
The defaults are 7% (run), 5% (cull) and 1% (stop) respectively.
The commands beginning with a 'b' are file space (block) limits, those
beginning with an 'f' are file count limits.
- (*) dir <path>
-
+ dir <path>
Specify the directory containing the root of the cache. Mandatory.
- (*) tag <name>
-
+ tag <name>
Specify a tag to FS-Cache to use in distinguishing multiple caches.
Optional. The default is "CacheFiles".
- (*) debug <mask>
-
+ debug <mask>
Specify a numeric bitmask to control debugging in the kernel module.
Optional. The default is zero (all off). The following values can be
OR'd into the mask to collect various information:
+ == =================================================
1 Turn on trace of function entry (_enter() macros)
2 Turn on trace of function exit (_leave() macros)
4 Turn on trace of internal debug points (_debug())
+ == =================================================
- This mask can also be set through sysfs, eg:
+ This mask can also be set through sysfs, eg::
echo 5 >/sys/modules/cachefiles/parameters/debug
-==================
-STARTING THE CACHE
+Starting the Cache
==================
The cache is started by running the daemon. The daemon opens the cache device,
configures the cache and tells it to begin caching. At that point the cache
binds to fscache and the cache becomes live.
-The daemon is run as follows:
+The daemon is run as follows::
/sbin/cachefilesd [-d]* [-s] [-n] [-f <configfile>]
The flags are:
- (*) -d
-
+ ``-d``
Increase the debugging level. This can be specified multiple times and
is cumulative with itself.
- (*) -s
-
+ ``-s``
Send messages to stderr instead of syslog.
- (*) -n
-
+ ``-n``
Don't daemonise and go into background.
- (*) -f <configfile>
-
+ ``-f <configfile>``
Use an alternative configuration file rather than the default one.
-===============
-THINGS TO AVOID
+Things to Avoid
===============
Do not mount other things within the cache as this will cause problems. The
@@ -179,8 +167,7 @@
permissions to prevent random users being able to access them directly.
-=============
-CACHE CULLING
+Cache Culling
=============
The cache may need culling occasionally to make space. This involves
@@ -192,27 +179,21 @@
percentage of files available in the underlying filesystem. There are six
"limits":
- (*) brun
- (*) frun
-
+ brun, frun
If the amount of free space and the number of available files in the cache
rises above both these limits, then culling is turned off.
- (*) bcull
- (*) fcull
-
+ bcull, fcull
If the amount of available space or the number of available files in the
cache falls below either of these limits, then culling is started.
- (*) bstop
- (*) fstop
-
+ bstop, fstop
If the amount of available space or the number of available files in the
cache falls below either of these limits, then no further allocation of
disk space or files is permitted until culling has raised things above
these limits again.
-These must be configured thusly:
+These must be configured thusly::
0 <= bstop < bcull < brun < 100
0 <= fstop < fcull < frun < 100
@@ -226,16 +207,14 @@
their atimes have changed or if the kernel module says it is still using them.
-===============
-CACHE STRUCTURE
+Cache Structure
===============
The CacheFiles module will create two directories in the directory it was
given:
- (*) cache/
-
- (*) graveyard/
+ * cache/
+ * graveyard/
The active cache objects all reside in the first directory. The CacheFiles
kernel module moves any retired or culled objects that it can't simply unlink
@@ -261,10 +240,10 @@
Immediately in the representative directory are a collection of directories
named for hash values of the child object keys with an '@' prepended. Into
this directory, if possible, will be placed the representations of the child
-objects:
+objects::
- INDEX INDEX INDEX DATA FILES
- ========= ========== ================================= ================
+ /INDEX /INDEX /INDEX /DATA FILES
+ /=========/==========/=================================/================
cache/@4a/I03nfs/@30/Ji000000000000000--fHg8hi8400
cache/@4a/I03nfs/@30/Ji000000000000000--fHg8hi8400/@75/Es0g000w...DB1ry
cache/@4a/I03nfs/@30/Ji000000000000000--fHg8hi8400/@75/Es0g000w...N22ry
@@ -275,7 +254,7 @@
it, then it will be cut into pieces, the first few of which will be used to
make a nest of directories, and the last one of which will be the objects
inside the last directory. The names of the intermediate directories will have
-'+' prepended:
+'+' prepended::
J1223/@23/+xy...z/+kl...m/Epqr
@@ -288,11 +267,13 @@
"base-64" encode ones that aren't directly suitable. The two versions of
object filenames indicate the encoding:
+ =============== =============== ===============
OBJECT TYPE PRINTABLE ENCODED
=============== =============== ===============
Index "I..." "J..."
Data "D..." "E..."
Special "S..." "T..."
+ =============== =============== ===============
Intermediate directories are always "@" or "+" as appropriate.
@@ -307,8 +288,7 @@
any file of an incorrect type (such as a FIFO file or a device file).
-==========================
-SECURITY MODEL AND SELINUX
+Security Model and SELinux
==========================
CacheFiles is implemented to deal properly with the LSM security features of
@@ -331,26 +311,26 @@
(1) Finds the security label attached to the root cache directory and uses
that as the security label with which it will create files. By default,
- this is:
+ this is::
cachefiles_var_t
(2) Finds the security label of the process which issued the bind request
- (presumed to be the cachefilesd daemon), which by default will be:
+ (presumed to be the cachefilesd daemon), which by default will be::
cachefilesd_t
and asks LSM to supply a security ID as which it should act given the
- daemon's label. By default, this will be:
+ daemon's label. By default, this will be::
cachefiles_kernel_t
SELinux transitions the daemon's security ID to the module's security ID
- based on a rule of this form in the policy.
+ based on a rule of this form in the policy::
type_transition <daemon's-ID> kernel_t : process <module's-ID>;
- For instance:
+ For instance::
type_transition cachefilesd_t kernel_t : process cachefiles_kernel_t;
@@ -370,7 +350,7 @@
http://people.redhat.com/~dhowells/fscache/cachefilesd-0.8.tar.bz2
-and later versions. In that tarball, see the files:
+and later versions. In that tarball, see the files::
cachefilesd.te
cachefilesd.fc
@@ -379,7 +359,7 @@
They are built and installed directly by the RPM.
If a non-RPM based system is being used, then copy the above files to their own
-directory and run:
+directory and run::
make -f /usr/share/selinux/devel/Makefile
semodule -i cachefilesd.pp
@@ -394,7 +374,7 @@
cache.
For instructions on how to add an auxiliary policy to enable the cache to be
-located elsewhere when SELinux is in enforcing mode, please see:
+located elsewhere when SELinux is in enforcing mode, please see::
/usr/share/doc/cachefilesd-*/move-cache.txt
@@ -402,8 +382,7 @@
in the sources.
-==================
-A NOTE ON SECURITY
+A Note on Security
==================
CacheFiles makes use of the split security in the task_struct. It allocates
@@ -445,17 +424,18 @@
files and directories with another security label.
-=======================
-STATISTICAL INFORMATION
+Statistical Information
=======================
-If FS-Cache is compiled with the following option enabled:
+If FS-Cache is compiled with the following option enabled::
CONFIG_CACHEFILES_HISTOGRAM=y
then it will gather certain statistics and display them through a proc file.
- (*) /proc/fs/cachefiles/histogram
+ /proc/fs/cachefiles/histogram
+
+ ::
cat /proc/fs/cachefiles/histogram
JIFS SECS LOOKUPS MKDIRS CREATES
@@ -465,36 +445,39 @@
between 0 jiffies and HZ-1 jiffies a variety of tasks took to run. The
columns are as follows:
+ ======= =======================================================
COLUMN TIME MEASUREMENT
======= =======================================================
LOOKUPS Length of time to perform a lookup on the backing fs
MKDIRS Length of time to perform a mkdir on the backing fs
CREATES Length of time to perform a create on the backing fs
+ ======= =======================================================
Each row shows the number of events that took a particular range of times.
Each step is 1 jiffy in size. The JIFS column indicates the particular
jiffy range covered, and the SECS field the equivalent number of seconds.
-=========
-DEBUGGING
+Debugging
=========
If CONFIG_CACHEFILES_DEBUG is enabled, the CacheFiles facility can have runtime
-debugging enabled by adjusting the value in:
+debugging enabled by adjusting the value in::
/sys/module/cachefiles/parameters/debug
This is a bitmask of debugging streams to enable:
+ ======= ======= =============================== =======================
BIT VALUE STREAM POINT
======= ======= =============================== =======================
0 1 General Function entry trace
1 2 Function exit trace
2 4 General
+ ======= ======= =============================== =======================
The appropriate set of values should be OR'd together and the result written to
-the control file. For example:
+the control file. For example::
echo $((1|4|8)) >/sys/module/cachefiles/parameters/debug
diff --git a/Documentation/filesystems/caching/fscache.rst b/Documentation/filesystems/caching/fscache.rst
new file mode 100644
index 0000000..70de869
--- /dev/null
+++ b/Documentation/filesystems/caching/fscache.rst
@@ -0,0 +1,565 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==========================
+General Filesystem Caching
+==========================
+
+Overview
+========
+
+This facility is a general purpose cache for network filesystems, though it
+could be used for caching other things such as ISO9660 filesystems too.
+
+FS-Cache mediates between cache backends (such as CacheFS) and network
+filesystems::
+
+ +---------+
+ | | +--------------+
+ | NFS |--+ | |
+ | | | +-->| CacheFS |
+ +---------+ | +----------+ | | /dev/hda5 |
+ | | | | +--------------+
+ +---------+ +-->| | |
+ | | | |--+
+ | AFS |----->| FS-Cache |
+ | | | |--+
+ +---------+ +-->| | |
+ | | | | +--------------+
+ +---------+ | +----------+ | | |
+ | | | +-->| CacheFiles |
+ | ISOFS |--+ | /var/cache |
+ | | +--------------+
+ +---------+
+
+Or to look at it another way, FS-Cache is a module that provides a caching
+facility to a network filesystem such that the cache is transparent to the
+user::
+
+ +---------+
+ | |
+ | Server |
+ | |
+ +---------+
+ | NETWORK
+ ~~~~~|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ |
+ | +----------+
+ V | |
+ +---------+ | |
+ | | | |
+ | NFS |----->| FS-Cache |
+ | | | |--+
+ +---------+ | | | +--------------+ +--------------+
+ | | | | | | | |
+ V +----------+ +-->| CacheFiles |-->| Ext3 |
+ +---------+ | /var/cache | | /dev/sda6 |
+ | | +--------------+ +--------------+
+ | VFS | ^ ^
+ | | | |
+ +---------+ +--------------+ |
+ | KERNEL SPACE | |
+ ~~~~~|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|~~~~~~|~~~~
+ | USER SPACE | |
+ V | |
+ +---------+ +--------------+
+ | | | |
+ | Process | | cachefilesd |
+ | | | |
+ +---------+ +--------------+
+
+
+FS-Cache does not follow the idea of completely loading every netfs file
+opened in its entirety into a cache before permitting it to be accessed and
+then serving the pages out of that cache rather than the netfs inode because:
+
+ (1) It must be practical to operate without a cache.
+
+ (2) The size of any accessible file must not be limited to the size of the
+ cache.
+
+ (3) The combined size of all opened files (this includes mapped libraries)
+ must not be limited to the size of the cache.
+
+ (4) The user should not be forced to download an entire file just to do a
+ one-off access of a small portion of it (such as might be done with the
+ "file" program).
+
+It instead serves the cache out in PAGE_SIZE chunks as and when requested by
+the netfs('s) using it.
+
+
+FS-Cache provides the following facilities:
+
+ (1) More than one cache can be used at once. Caches can be selected
+ explicitly by use of tags.
+
+ (2) Caches can be added / removed at any time.
+
+ (3) The netfs is provided with an interface that allows either party to
+ withdraw caching facilities from a file (required for (2)).
+
+ (4) The interface to the netfs returns as few errors as possible, preferring
+ rather to let the netfs remain oblivious.
+
+ (5) Cookies are used to represent indices, files and other objects to the
+ netfs. The simplest cookie is just a NULL pointer - indicating nothing
+ cached there.
+
+ (6) The netfs is allowed to propose - dynamically - any index hierarchy it
+ desires, though it must be aware that the index search function is
+ recursive, stack space is limited, and indices can only be children of
+ indices.
+
+ (7) Data I/O is done direct to and from the netfs's pages. The netfs
+ indicates that page A is at index B of the data-file represented by cookie
+ C, and that it should be read or written. The cache backend may or may
+ not start I/O on that page, but if it does, a netfs callback will be
+ invoked to indicate completion. The I/O may be either synchronous or
+ asynchronous.
+
+ (8) Cookies can be "retired" upon release. At this point FS-Cache will mark
+ them as obsolete and the index hierarchy rooted at that point will get
+ recycled.
+
+ (9) The netfs provides a "match" function for index searches. In addition to
+ saying whether a match was made or not, this can also specify that an
+ entry should be updated or deleted.
+
+(10) As much as possible is done asynchronously.
+
+
+FS-Cache maintains a virtual indexing tree in which all indices, files, objects
+and pages are kept. Bits of this tree may actually reside in one or more
+caches::
+
+ FSDEF
+ |
+ +------------------------------------+
+ | |
+ NFS AFS
+ | |
+ +--------------------------+ +-----------+
+ | | | |
+ homedir mirror afs.org redhat.com
+ | | |
+ +------------+ +---------------+ +----------+
+ | | | | | |
+ 00001 00002 00007 00125 vol00001 vol00002
+ | | | | |
+ +---+---+ +-----+ +---+ +------+------+ +-----+----+
+ | | | | | | | | | | | | |
+ PG0 PG1 PG2 PG0 XATTR PG0 PG1 DIRENT DIRENT DIRENT R/W R/O Bak
+ | |
+ PG0 +-------+
+ | |
+ 00001 00003
+ |
+ +---+---+
+ | | |
+ PG0 PG1 PG2
+
+In the example above, you can see two netfs's being backed: NFS and AFS. These
+have different index hierarchies:
+
+ * The NFS primary index contains per-server indices. Each server index is
+ indexed by NFS file handles to get data file objects. Each data file
+ objects can have an array of pages, but may also have further child
+ objects, such as extended attributes and directory entries. Extended
+ attribute objects themselves have page-array contents.
+
+ * The AFS primary index contains per-cell indices. Each cell index contains
+ per-logical-volume indices. Each of volume index contains up to three
+ indices for the read-write, read-only and backup mirrors of those volumes.
+ Each of these contains vnode data file objects, each of which contains an
+ array of pages.
+
+The very top index is the FS-Cache master index in which individual netfs's
+have entries.
+
+Any index object may reside in more than one cache, provided it only has index
+children. Any index with non-index object children will be assumed to only
+reside in one cache.
+
+
+The netfs API to FS-Cache can be found in:
+
+ Documentation/filesystems/caching/netfs-api.rst
+
+The cache backend API to FS-Cache can be found in:
+
+ Documentation/filesystems/caching/backend-api.rst
+
+A description of the internal representations and object state machine can be
+found in:
+
+ Documentation/filesystems/caching/object.rst
+
+
+Statistical Information
+=======================
+
+If FS-Cache is compiled with the following options enabled::
+
+ CONFIG_FSCACHE_STATS=y
+ CONFIG_FSCACHE_HISTOGRAM=y
+
+then it will gather certain statistics and display them through a number of
+proc files.
+
+/proc/fs/fscache/stats
+----------------------
+
+ This shows counts of a number of events that can happen in FS-Cache:
+
++--------------+-------+-------------------------------------------------------+
+|CLASS |EVENT |MEANING |
++==============+=======+=======================================================+
+|Cookies |idx=N |Number of index cookies allocated |
++ +-------+-------------------------------------------------------+
+| |dat=N |Number of data storage cookies allocated |
++ +-------+-------------------------------------------------------+
+| |spc=N |Number of special cookies allocated |
++--------------+-------+-------------------------------------------------------+
+|Objects |alc=N |Number of objects allocated |
++ +-------+-------------------------------------------------------+
+| |nal=N |Number of object allocation failures |
++ +-------+-------------------------------------------------------+
+| |avl=N |Number of objects that reached the available state |
++ +-------+-------------------------------------------------------+
+| |ded=N |Number of objects that reached the dead state |
++--------------+-------+-------------------------------------------------------+
+|ChkAux |non=N |Number of objects that didn't have a coherency check |
++ +-------+-------------------------------------------------------+
+| |ok=N |Number of objects that passed a coherency check |
++ +-------+-------------------------------------------------------+
+| |upd=N |Number of objects that needed a coherency data update |
++ +-------+-------------------------------------------------------+
+| |obs=N |Number of objects that were declared obsolete |
++--------------+-------+-------------------------------------------------------+
+|Pages |mrk=N |Number of pages marked as being cached |
+| |unc=N |Number of uncache page requests seen |
++--------------+-------+-------------------------------------------------------+
+|Acquire |n=N |Number of acquire cookie requests seen |
++ +-------+-------------------------------------------------------+
+| |nul=N |Number of acq reqs given a NULL parent |
++ +-------+-------------------------------------------------------+
+| |noc=N |Number of acq reqs rejected due to no cache available |
++ +-------+-------------------------------------------------------+
+| |ok=N |Number of acq reqs succeeded |
++ +-------+-------------------------------------------------------+
+| |nbf=N |Number of acq reqs rejected due to error |
++ +-------+-------------------------------------------------------+
+| |oom=N |Number of acq reqs failed on ENOMEM |
++--------------+-------+-------------------------------------------------------+
+|Lookups |n=N |Number of lookup calls made on cache backends |
++ +-------+-------------------------------------------------------+
+| |neg=N |Number of negative lookups made |
++ +-------+-------------------------------------------------------+
+| |pos=N |Number of positive lookups made |
++ +-------+-------------------------------------------------------+
+| |crt=N |Number of objects created by lookup |
++ +-------+-------------------------------------------------------+
+| |tmo=N |Number of lookups timed out and requeued |
++--------------+-------+-------------------------------------------------------+
+|Updates |n=N |Number of update cookie requests seen |
++ +-------+-------------------------------------------------------+
+| |nul=N |Number of upd reqs given a NULL parent |
++ +-------+-------------------------------------------------------+
+| |run=N |Number of upd reqs granted CPU time |
++--------------+-------+-------------------------------------------------------+
+|Relinqs |n=N |Number of relinquish cookie requests seen |
++ +-------+-------------------------------------------------------+
+| |nul=N |Number of rlq reqs given a NULL parent |
++ +-------+-------------------------------------------------------+
+| |wcr=N |Number of rlq reqs waited on completion of creation |
++--------------+-------+-------------------------------------------------------+
+|AttrChg |n=N |Number of attribute changed requests seen |
++ +-------+-------------------------------------------------------+
+| |ok=N |Number of attr changed requests queued |
++ +-------+-------------------------------------------------------+
+| |nbf=N |Number of attr changed rejected -ENOBUFS |
++ +-------+-------------------------------------------------------+
+| |oom=N |Number of attr changed failed -ENOMEM |
++ +-------+-------------------------------------------------------+
+| |run=N |Number of attr changed ops given CPU time |
++--------------+-------+-------------------------------------------------------+
+|Allocs |n=N |Number of allocation requests seen |
++ +-------+-------------------------------------------------------+
+| |ok=N |Number of successful alloc reqs |
++ +-------+-------------------------------------------------------+
+| |wt=N |Number of alloc reqs that waited on lookup completion |
++ +-------+-------------------------------------------------------+
+| |nbf=N |Number of alloc reqs rejected -ENOBUFS |
++ +-------+-------------------------------------------------------+
+| |int=N |Number of alloc reqs aborted -ERESTARTSYS |
++ +-------+-------------------------------------------------------+
+| |ops=N |Number of alloc reqs submitted |
++ +-------+-------------------------------------------------------+
+| |owt=N |Number of alloc reqs waited for CPU time |
++ +-------+-------------------------------------------------------+
+| |abt=N |Number of alloc reqs aborted due to object death |
++--------------+-------+-------------------------------------------------------+
+|Retrvls |n=N |Number of retrieval (read) requests seen |
++ +-------+-------------------------------------------------------+
+| |ok=N |Number of successful retr reqs |
++ +-------+-------------------------------------------------------+
+| |wt=N |Number of retr reqs that waited on lookup completion |
++ +-------+-------------------------------------------------------+
+| |nod=N |Number of retr reqs returned -ENODATA |
++ +-------+-------------------------------------------------------+
+| |nbf=N |Number of retr reqs rejected -ENOBUFS |
++ +-------+-------------------------------------------------------+
+| |int=N |Number of retr reqs aborted -ERESTARTSYS |
++ +-------+-------------------------------------------------------+
+| |oom=N |Number of retr reqs failed -ENOMEM |
++ +-------+-------------------------------------------------------+
+| |ops=N |Number of retr reqs submitted |
++ +-------+-------------------------------------------------------+
+| |owt=N |Number of retr reqs waited for CPU time |
++ +-------+-------------------------------------------------------+
+| |abt=N |Number of retr reqs aborted due to object death |
++--------------+-------+-------------------------------------------------------+
+|Stores |n=N |Number of storage (write) requests seen |
++ +-------+-------------------------------------------------------+
+| |ok=N |Number of successful store reqs |
++ +-------+-------------------------------------------------------+
+| |agn=N |Number of store reqs on a page already pending storage |
++ +-------+-------------------------------------------------------+
+| |nbf=N |Number of store reqs rejected -ENOBUFS |
++ +-------+-------------------------------------------------------+
+| |oom=N |Number of store reqs failed -ENOMEM |
++ +-------+-------------------------------------------------------+
+| |ops=N |Number of store reqs submitted |
++ +-------+-------------------------------------------------------+
+| |run=N |Number of store reqs granted CPU time |
++ +-------+-------------------------------------------------------+
+| |pgs=N |Number of pages given store req processing time |
++ +-------+-------------------------------------------------------+
+| |rxd=N |Number of store reqs deleted from tracking tree |
++ +-------+-------------------------------------------------------+
+| |olm=N |Number of store reqs over store limit |
++--------------+-------+-------------------------------------------------------+
+|VmScan |nos=N |Number of release reqs against pages with no |
+| | |pending store |
++ +-------+-------------------------------------------------------+
+| |gon=N |Number of release reqs against pages stored by |
+| | |time lock granted |
++ +-------+-------------------------------------------------------+
+| |bsy=N |Number of release reqs ignored due to in-progress store|
++ +-------+-------------------------------------------------------+
+| |can=N |Number of page stores cancelled due to release req |
++--------------+-------+-------------------------------------------------------+
+|Ops |pend=N |Number of times async ops added to pending queues |
++ +-------+-------------------------------------------------------+
+| |run=N |Number of times async ops given CPU time |
++ +-------+-------------------------------------------------------+
+| |enq=N |Number of times async ops queued for processing |
++ +-------+-------------------------------------------------------+
+| |can=N |Number of async ops cancelled |
++ +-------+-------------------------------------------------------+
+| |rej=N |Number of async ops rejected due to object |
+| | |lookup/create failure |
++ +-------+-------------------------------------------------------+
+| |ini=N |Number of async ops initialised |
++ +-------+-------------------------------------------------------+
+| |dfr=N |Number of async ops queued for deferred release |
++ +-------+-------------------------------------------------------+
+| |rel=N |Number of async ops released |
+| | |(should equal ini=N when idle) |
++ +-------+-------------------------------------------------------+
+| |gc=N |Number of deferred-release async ops garbage collected |
++--------------+-------+-------------------------------------------------------+
+|CacheOp |alo=N |Number of in-progress alloc_object() cache ops |
++ +-------+-------------------------------------------------------+
+| |luo=N |Number of in-progress lookup_object() cache ops |
++ +-------+-------------------------------------------------------+
+| |luc=N |Number of in-progress lookup_complete() cache ops |
++ +-------+-------------------------------------------------------+
+| |gro=N |Number of in-progress grab_object() cache ops |
++ +-------+-------------------------------------------------------+
+| |upo=N |Number of in-progress update_object() cache ops |
++ +-------+-------------------------------------------------------+
+| |dro=N |Number of in-progress drop_object() cache ops |
++ +-------+-------------------------------------------------------+
+| |pto=N |Number of in-progress put_object() cache ops |
++ +-------+-------------------------------------------------------+
+| |syn=N |Number of in-progress sync_cache() cache ops |
++ +-------+-------------------------------------------------------+
+| |atc=N |Number of in-progress attr_changed() cache ops |
++ +-------+-------------------------------------------------------+
+| |rap=N |Number of in-progress read_or_alloc_page() cache ops |
++ +-------+-------------------------------------------------------+
+| |ras=N |Number of in-progress read_or_alloc_pages() cache ops |
++ +-------+-------------------------------------------------------+
+| |alp=N |Number of in-progress allocate_page() cache ops |
++ +-------+-------------------------------------------------------+
+| |als=N |Number of in-progress allocate_pages() cache ops |
++ +-------+-------------------------------------------------------+
+| |wrp=N |Number of in-progress write_page() cache ops |
++ +-------+-------------------------------------------------------+
+| |ucp=N |Number of in-progress uncache_page() cache ops |
++ +-------+-------------------------------------------------------+
+| |dsp=N |Number of in-progress dissociate_pages() cache ops |
++--------------+-------+-------------------------------------------------------+
+|CacheEv |nsp=N |Number of object lookups/creations rejected due to |
+| | |lack of space |
++ +-------+-------------------------------------------------------+
+| |stl=N |Number of stale objects deleted |
++ +-------+-------------------------------------------------------+
+| |rtr=N |Number of objects retired when relinquished |
++ +-------+-------------------------------------------------------+
+| |cul=N |Number of objects culled |
++--------------+-------+-------------------------------------------------------+
+
+
+
+/proc/fs/fscache/histogram
+--------------------------
+
+ ::
+
+ cat /proc/fs/fscache/histogram
+ JIFS SECS OBJ INST OP RUNS OBJ RUNS RETRV DLY RETRIEVLS
+ ===== ===== ========= ========= ========= ========= =========
+
+ This shows the breakdown of the number of times each amount of time
+ between 0 jiffies and HZ-1 jiffies a variety of tasks took to run. The
+ columns are as follows:
+
+ ========= =======================================================
+ COLUMN TIME MEASUREMENT
+ ========= =======================================================
+ OBJ INST Length of time to instantiate an object
+ OP RUNS Length of time a call to process an operation took
+ OBJ RUNS Length of time a call to process an object event took
+ RETRV DLY Time between an requesting a read and lookup completing
+ RETRIEVLS Time between beginning and end of a retrieval
+ ========= =======================================================
+
+ Each row shows the number of events that took a particular range of times.
+ Each step is 1 jiffy in size. The JIFS column indicates the particular
+ jiffy range covered, and the SECS field the equivalent number of seconds.
+
+
+
+Object List
+===========
+
+If CONFIG_FSCACHE_OBJECT_LIST is enabled, the FS-Cache facility will maintain a
+list of all the objects currently allocated and allow them to be viewed
+through::
+
+ /proc/fs/fscache/objects
+
+This will look something like::
+
+ [root@andromeda ~]# head /proc/fs/fscache/objects
+ OBJECT PARENT STAT CHLDN OPS OOP IPR EX READS EM EV F S | NETFS_COOKIE_DEF TY FL NETFS_DATA OBJECT_KEY, AUX_DATA
+ ======== ======== ==== ===== === === === == ===== == == = = | ================ == == ================ ================
+ 17e4b 2 ACTV 0 0 0 0 0 0 7b 4 0 0 | NFS.fh DT 0 ffff88001dd82820 010006017edcf8bbc93b43298fdfbe71e50b57b13a172c0117f38472, e567634700000000000000000000000063f2404a000000000000000000000000c9030000000000000000000063f2404a
+ 1693a 2 ACTV 0 0 0 0 0 0 7b 4 0 0 | NFS.fh DT 0 ffff88002db23380 010006017edcf8bbc93b43298fdfbe71e50b57b1e0162c01a2df0ea6, 420ebc4a000000000000000000000000420ebc4a0000000000000000000000000e1801000000000000000000420ebc4a
+
+where the first set of columns before the '|' describe the object:
+
+ ======= ===============================================================
+ COLUMN DESCRIPTION
+ ======= ===============================================================
+ OBJECT Object debugging ID (appears as OBJ%x in some debug messages)
+ PARENT Debugging ID of parent object
+ STAT Object state
+ CHLDN Number of child objects of this object
+ OPS Number of outstanding operations on this object
+ OOP Number of outstanding child object management operations
+ IPR
+ EX Number of outstanding exclusive operations
+ READS Number of outstanding read operations
+ EM Object's event mask
+ EV Events raised on this object
+ F Object flags
+ S Object work item busy state mask (1:pending 2:running)
+ ======= ===============================================================
+
+and the second set of columns describe the object's cookie, if present:
+
+ ================ ======================================================
+ COLUMN DESCRIPTION
+ ================ ======================================================
+ NETFS_COOKIE_DEF Name of netfs cookie definition
+ TY Cookie type (IX - index, DT - data, hex - special)
+ FL Cookie flags
+ NETFS_DATA Netfs private data stored in the cookie
+ OBJECT_KEY Object key } 1 column, with separating comma
+ AUX_DATA Object aux data } presence may be configured
+ ================ ======================================================
+
+The data shown may be filtered by attaching the a key to an appropriate keyring
+before viewing the file. Something like::
+
+ keyctl add user fscache:objlist <restrictions> @s
+
+where <restrictions> are a selection of the following letters:
+
+ == =========================================================
+ K Show hexdump of object key (don't show if not given)
+ A Show hexdump of object aux data (don't show if not given)
+ == =========================================================
+
+and the following paired letters:
+
+ == =========================================================
+ C Show objects that have a cookie
+ c Show objects that don't have a cookie
+ B Show objects that are busy
+ b Show objects that aren't busy
+ W Show objects that have pending writes
+ w Show objects that don't have pending writes
+ R Show objects that have outstanding reads
+ r Show objects that don't have outstanding reads
+ S Show objects that have work queued
+ s Show objects that don't have work queued
+ == =========================================================
+
+If neither side of a letter pair is given, then both are implied. For example:
+
+ keyctl add user fscache:objlist KB @s
+
+shows objects that are busy, and lists their object keys, but does not dump
+their auxiliary data. It also implies "CcWwRrSs", but as 'B' is given, 'b' is
+not implied.
+
+By default all objects and all fields will be shown.
+
+
+Debugging
+=========
+
+If CONFIG_FSCACHE_DEBUG is enabled, the FS-Cache facility can have runtime
+debugging enabled by adjusting the value in::
+
+ /sys/module/fscache/parameters/debug
+
+This is a bitmask of debugging streams to enable:
+
+ ======= ======= =============================== =======================
+ BIT VALUE STREAM POINT
+ ======= ======= =============================== =======================
+ 0 1 Cache management Function entry trace
+ 1 2 Function exit trace
+ 2 4 General
+ 3 8 Cookie management Function entry trace
+ 4 16 Function exit trace
+ 5 32 General
+ 6 64 Page handling Function entry trace
+ 7 128 Function exit trace
+ 8 256 General
+ 9 512 Operation management Function entry trace
+ 10 1024 Function exit trace
+ 11 2048 General
+ ======= ======= =============================== =======================
+
+The appropriate set of values should be OR'd together and the result written to
+the control file. For example::
+
+ echo $((1|8|64)) >/sys/module/fscache/parameters/debug
+
+will turn on all function entry debugging.
diff --git a/Documentation/filesystems/caching/fscache.txt b/Documentation/filesystems/caching/fscache.txt
deleted file mode 100644
index 50f0a57..0000000
--- a/Documentation/filesystems/caching/fscache.txt
+++ /dev/null
@@ -1,448 +0,0 @@
- ==========================
- General Filesystem Caching
- ==========================
-
-========
-OVERVIEW
-========
-
-This facility is a general purpose cache for network filesystems, though it
-could be used for caching other things such as ISO9660 filesystems too.
-
-FS-Cache mediates between cache backends (such as CacheFS) and network
-filesystems:
-
- +---------+
- | | +--------------+
- | NFS |--+ | |
- | | | +-->| CacheFS |
- +---------+ | +----------+ | | /dev/hda5 |
- | | | | +--------------+
- +---------+ +-->| | |
- | | | |--+
- | AFS |----->| FS-Cache |
- | | | |--+
- +---------+ +-->| | |
- | | | | +--------------+
- +---------+ | +----------+ | | |
- | | | +-->| CacheFiles |
- | ISOFS |--+ | /var/cache |
- | | +--------------+
- +---------+
-
-Or to look at it another way, FS-Cache is a module that provides a caching
-facility to a network filesystem such that the cache is transparent to the
-user:
-
- +---------+
- | |
- | Server |
- | |
- +---------+
- | NETWORK
- ~~~~~|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- |
- | +----------+
- V | |
- +---------+ | |
- | | | |
- | NFS |----->| FS-Cache |
- | | | |--+
- +---------+ | | | +--------------+ +--------------+
- | | | | | | | |
- V +----------+ +-->| CacheFiles |-->| Ext3 |
- +---------+ | /var/cache | | /dev/sda6 |
- | | +--------------+ +--------------+
- | VFS | ^ ^
- | | | |
- +---------+ +--------------+ |
- | KERNEL SPACE | |
- ~~~~~|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|~~~~~~|~~~~
- | USER SPACE | |
- V | |
- +---------+ +--------------+
- | | | |
- | Process | | cachefilesd |
- | | | |
- +---------+ +--------------+
-
-
-FS-Cache does not follow the idea of completely loading every netfs file
-opened in its entirety into a cache before permitting it to be accessed and
-then serving the pages out of that cache rather than the netfs inode because:
-
- (1) It must be practical to operate without a cache.
-
- (2) The size of any accessible file must not be limited to the size of the
- cache.
-
- (3) The combined size of all opened files (this includes mapped libraries)
- must not be limited to the size of the cache.
-
- (4) The user should not be forced to download an entire file just to do a
- one-off access of a small portion of it (such as might be done with the
- "file" program).
-
-It instead serves the cache out in PAGE_SIZE chunks as and when requested by
-the netfs('s) using it.
-
-
-FS-Cache provides the following facilities:
-
- (1) More than one cache can be used at once. Caches can be selected
- explicitly by use of tags.
-
- (2) Caches can be added / removed at any time.
-
- (3) The netfs is provided with an interface that allows either party to
- withdraw caching facilities from a file (required for (2)).
-
- (4) The interface to the netfs returns as few errors as possible, preferring
- rather to let the netfs remain oblivious.
-
- (5) Cookies are used to represent indices, files and other objects to the
- netfs. The simplest cookie is just a NULL pointer - indicating nothing
- cached there.
-
- (6) The netfs is allowed to propose - dynamically - any index hierarchy it
- desires, though it must be aware that the index search function is
- recursive, stack space is limited, and indices can only be children of
- indices.
-
- (7) Data I/O is done direct to and from the netfs's pages. The netfs
- indicates that page A is at index B of the data-file represented by cookie
- C, and that it should be read or written. The cache backend may or may
- not start I/O on that page, but if it does, a netfs callback will be
- invoked to indicate completion. The I/O may be either synchronous or
- asynchronous.
-
- (8) Cookies can be "retired" upon release. At this point FS-Cache will mark
- them as obsolete and the index hierarchy rooted at that point will get
- recycled.
-
- (9) The netfs provides a "match" function for index searches. In addition to
- saying whether a match was made or not, this can also specify that an
- entry should be updated or deleted.
-
-(10) As much as possible is done asynchronously.
-
-
-FS-Cache maintains a virtual indexing tree in which all indices, files, objects
-and pages are kept. Bits of this tree may actually reside in one or more
-caches.
-
- FSDEF
- |
- +------------------------------------+
- | |
- NFS AFS
- | |
- +--------------------------+ +-----------+
- | | | |
- homedir mirror afs.org redhat.com
- | | |
- +------------+ +---------------+ +----------+
- | | | | | |
- 00001 00002 00007 00125 vol00001 vol00002
- | | | | |
- +---+---+ +-----+ +---+ +------+------+ +-----+----+
- | | | | | | | | | | | | |
-PG0 PG1 PG2 PG0 XATTR PG0 PG1 DIRENT DIRENT DIRENT R/W R/O Bak
- | |
- PG0 +-------+
- | |
- 00001 00003
- |
- +---+---+
- | | |
- PG0 PG1 PG2
-
-In the example above, you can see two netfs's being backed: NFS and AFS. These
-have different index hierarchies:
-
- (*) The NFS primary index contains per-server indices. Each server index is
- indexed by NFS file handles to get data file objects. Each data file
- objects can have an array of pages, but may also have further child
- objects, such as extended attributes and directory entries. Extended
- attribute objects themselves have page-array contents.
-
- (*) The AFS primary index contains per-cell indices. Each cell index contains
- per-logical-volume indices. Each of volume index contains up to three
- indices for the read-write, read-only and backup mirrors of those volumes.
- Each of these contains vnode data file objects, each of which contains an
- array of pages.
-
-The very top index is the FS-Cache master index in which individual netfs's
-have entries.
-
-Any index object may reside in more than one cache, provided it only has index
-children. Any index with non-index object children will be assumed to only
-reside in one cache.
-
-
-The netfs API to FS-Cache can be found in:
-
- Documentation/filesystems/caching/netfs-api.txt
-
-The cache backend API to FS-Cache can be found in:
-
- Documentation/filesystems/caching/backend-api.txt
-
-A description of the internal representations and object state machine can be
-found in:
-
- Documentation/filesystems/caching/object.txt
-
-
-=======================
-STATISTICAL INFORMATION
-=======================
-
-If FS-Cache is compiled with the following options enabled:
-
- CONFIG_FSCACHE_STATS=y
- CONFIG_FSCACHE_HISTOGRAM=y
-
-then it will gather certain statistics and display them through a number of
-proc files.
-
- (*) /proc/fs/fscache/stats
-
- This shows counts of a number of events that can happen in FS-Cache:
-
- CLASS EVENT MEANING
- ======= ======= =======================================================
- Cookies idx=N Number of index cookies allocated
- dat=N Number of data storage cookies allocated
- spc=N Number of special cookies allocated
- Objects alc=N Number of objects allocated
- nal=N Number of object allocation failures
- avl=N Number of objects that reached the available state
- ded=N Number of objects that reached the dead state
- ChkAux non=N Number of objects that didn't have a coherency check
- ok=N Number of objects that passed a coherency check
- upd=N Number of objects that needed a coherency data update
- obs=N Number of objects that were declared obsolete
- Pages mrk=N Number of pages marked as being cached
- unc=N Number of uncache page requests seen
- Acquire n=N Number of acquire cookie requests seen
- nul=N Number of acq reqs given a NULL parent
- noc=N Number of acq reqs rejected due to no cache available
- ok=N Number of acq reqs succeeded
- nbf=N Number of acq reqs rejected due to error
- oom=N Number of acq reqs failed on ENOMEM
- Lookups n=N Number of lookup calls made on cache backends
- neg=N Number of negative lookups made
- pos=N Number of positive lookups made
- crt=N Number of objects created by lookup
- tmo=N Number of lookups timed out and requeued
- Updates n=N Number of update cookie requests seen
- nul=N Number of upd reqs given a NULL parent
- run=N Number of upd reqs granted CPU time
- Relinqs n=N Number of relinquish cookie requests seen
- nul=N Number of rlq reqs given a NULL parent
- wcr=N Number of rlq reqs waited on completion of creation
- AttrChg n=N Number of attribute changed requests seen
- ok=N Number of attr changed requests queued
- nbf=N Number of attr changed rejected -ENOBUFS
- oom=N Number of attr changed failed -ENOMEM
- run=N Number of attr changed ops given CPU time
- Allocs n=N Number of allocation requests seen
- ok=N Number of successful alloc reqs
- wt=N Number of alloc reqs that waited on lookup completion
- nbf=N Number of alloc reqs rejected -ENOBUFS
- int=N Number of alloc reqs aborted -ERESTARTSYS
- ops=N Number of alloc reqs submitted
- owt=N Number of alloc reqs waited for CPU time
- abt=N Number of alloc reqs aborted due to object death
- Retrvls n=N Number of retrieval (read) requests seen
- ok=N Number of successful retr reqs
- wt=N Number of retr reqs that waited on lookup completion
- nod=N Number of retr reqs returned -ENODATA
- nbf=N Number of retr reqs rejected -ENOBUFS
- int=N Number of retr reqs aborted -ERESTARTSYS
- oom=N Number of retr reqs failed -ENOMEM
- ops=N Number of retr reqs submitted
- owt=N Number of retr reqs waited for CPU time
- abt=N Number of retr reqs aborted due to object death
- Stores n=N Number of storage (write) requests seen
- ok=N Number of successful store reqs
- agn=N Number of store reqs on a page already pending storage
- nbf=N Number of store reqs rejected -ENOBUFS
- oom=N Number of store reqs failed -ENOMEM
- ops=N Number of store reqs submitted
- run=N Number of store reqs granted CPU time
- pgs=N Number of pages given store req processing time
- rxd=N Number of store reqs deleted from tracking tree
- olm=N Number of store reqs over store limit
- VmScan nos=N Number of release reqs against pages with no pending store
- gon=N Number of release reqs against pages stored by time lock granted
- bsy=N Number of release reqs ignored due to in-progress store
- can=N Number of page stores cancelled due to release req
- Ops pend=N Number of times async ops added to pending queues
- run=N Number of times async ops given CPU time
- enq=N Number of times async ops queued for processing
- can=N Number of async ops cancelled
- rej=N Number of async ops rejected due to object lookup/create failure
- ini=N Number of async ops initialised
- dfr=N Number of async ops queued for deferred release
- rel=N Number of async ops released (should equal ini=N when idle)
- gc=N Number of deferred-release async ops garbage collected
- CacheOp alo=N Number of in-progress alloc_object() cache ops
- luo=N Number of in-progress lookup_object() cache ops
- luc=N Number of in-progress lookup_complete() cache ops
- gro=N Number of in-progress grab_object() cache ops
- upo=N Number of in-progress update_object() cache ops
- dro=N Number of in-progress drop_object() cache ops
- pto=N Number of in-progress put_object() cache ops
- syn=N Number of in-progress sync_cache() cache ops
- atc=N Number of in-progress attr_changed() cache ops
- rap=N Number of in-progress read_or_alloc_page() cache ops
- ras=N Number of in-progress read_or_alloc_pages() cache ops
- alp=N Number of in-progress allocate_page() cache ops
- als=N Number of in-progress allocate_pages() cache ops
- wrp=N Number of in-progress write_page() cache ops
- ucp=N Number of in-progress uncache_page() cache ops
- dsp=N Number of in-progress dissociate_pages() cache ops
- CacheEv nsp=N Number of object lookups/creations rejected due to lack of space
- stl=N Number of stale objects deleted
- rtr=N Number of objects retired when relinquished
- cul=N Number of objects culled
-
-
- (*) /proc/fs/fscache/histogram
-
- cat /proc/fs/fscache/histogram
- JIFS SECS OBJ INST OP RUNS OBJ RUNS RETRV DLY RETRIEVLS
- ===== ===== ========= ========= ========= ========= =========
-
- This shows the breakdown of the number of times each amount of time
- between 0 jiffies and HZ-1 jiffies a variety of tasks took to run. The
- columns are as follows:
-
- COLUMN TIME MEASUREMENT
- ======= =======================================================
- OBJ INST Length of time to instantiate an object
- OP RUNS Length of time a call to process an operation took
- OBJ RUNS Length of time a call to process an object event took
- RETRV DLY Time between an requesting a read and lookup completing
- RETRIEVLS Time between beginning and end of a retrieval
-
- Each row shows the number of events that took a particular range of times.
- Each step is 1 jiffy in size. The JIFS column indicates the particular
- jiffy range covered, and the SECS field the equivalent number of seconds.
-
-
-===========
-OBJECT LIST
-===========
-
-If CONFIG_FSCACHE_OBJECT_LIST is enabled, the FS-Cache facility will maintain a
-list of all the objects currently allocated and allow them to be viewed
-through:
-
- /proc/fs/fscache/objects
-
-This will look something like:
-
- [root@andromeda ~]# head /proc/fs/fscache/objects
- OBJECT PARENT STAT CHLDN OPS OOP IPR EX READS EM EV F S | NETFS_COOKIE_DEF TY FL NETFS_DATA OBJECT_KEY, AUX_DATA
- ======== ======== ==== ===== === === === == ===== == == = = | ================ == == ================ ================
- 17e4b 2 ACTV 0 0 0 0 0 0 7b 4 0 0 | NFS.fh DT 0 ffff88001dd82820 010006017edcf8bbc93b43298fdfbe71e50b57b13a172c0117f38472, e567634700000000000000000000000063f2404a000000000000000000000000c9030000000000000000000063f2404a
- 1693a 2 ACTV 0 0 0 0 0 0 7b 4 0 0 | NFS.fh DT 0 ffff88002db23380 010006017edcf8bbc93b43298fdfbe71e50b57b1e0162c01a2df0ea6, 420ebc4a000000000000000000000000420ebc4a0000000000000000000000000e1801000000000000000000420ebc4a
-
-where the first set of columns before the '|' describe the object:
-
- COLUMN DESCRIPTION
- ======= ===============================================================
- OBJECT Object debugging ID (appears as OBJ%x in some debug messages)
- PARENT Debugging ID of parent object
- STAT Object state
- CHLDN Number of child objects of this object
- OPS Number of outstanding operations on this object
- OOP Number of outstanding child object management operations
- IPR
- EX Number of outstanding exclusive operations
- READS Number of outstanding read operations
- EM Object's event mask
- EV Events raised on this object
- F Object flags
- S Object work item busy state mask (1:pending 2:running)
-
-and the second set of columns describe the object's cookie, if present:
-
- COLUMN DESCRIPTION
- =============== =======================================================
- NETFS_COOKIE_DEF Name of netfs cookie definition
- TY Cookie type (IX - index, DT - data, hex - special)
- FL Cookie flags
- NETFS_DATA Netfs private data stored in the cookie
- OBJECT_KEY Object key } 1 column, with separating comma
- AUX_DATA Object aux data } presence may be configured
-
-The data shown may be filtered by attaching the a key to an appropriate keyring
-before viewing the file. Something like:
-
- keyctl add user fscache:objlist <restrictions> @s
-
-where <restrictions> are a selection of the following letters:
-
- K Show hexdump of object key (don't show if not given)
- A Show hexdump of object aux data (don't show if not given)
-
-and the following paired letters:
-
- C Show objects that have a cookie
- c Show objects that don't have a cookie
- B Show objects that are busy
- b Show objects that aren't busy
- W Show objects that have pending writes
- w Show objects that don't have pending writes
- R Show objects that have outstanding reads
- r Show objects that don't have outstanding reads
- S Show objects that have work queued
- s Show objects that don't have work queued
-
-If neither side of a letter pair is given, then both are implied. For example:
-
- keyctl add user fscache:objlist KB @s
-
-shows objects that are busy, and lists their object keys, but does not dump
-their auxiliary data. It also implies "CcWwRrSs", but as 'B' is given, 'b' is
-not implied.
-
-By default all objects and all fields will be shown.
-
-
-=========
-DEBUGGING
-=========
-
-If CONFIG_FSCACHE_DEBUG is enabled, the FS-Cache facility can have runtime
-debugging enabled by adjusting the value in:
-
- /sys/module/fscache/parameters/debug
-
-This is a bitmask of debugging streams to enable:
-
- BIT VALUE STREAM POINT
- ======= ======= =============================== =======================
- 0 1 Cache management Function entry trace
- 1 2 Function exit trace
- 2 4 General
- 3 8 Cookie management Function entry trace
- 4 16 Function exit trace
- 5 32 General
- 6 64 Page handling Function entry trace
- 7 128 Function exit trace
- 8 256 General
- 9 512 Operation management Function entry trace
- 10 1024 Function exit trace
- 11 2048 General
-
-The appropriate set of values should be OR'd together and the result written to
-the control file. For example:
-
- echo $((1|8|64)) >/sys/module/fscache/parameters/debug
-
-will turn on all function entry debugging.
diff --git a/Documentation/filesystems/caching/index.rst b/Documentation/filesystems/caching/index.rst
new file mode 100644
index 0000000..033da7a
--- /dev/null
+++ b/Documentation/filesystems/caching/index.rst
@@ -0,0 +1,14 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Filesystem Caching
+==================
+
+.. toctree::
+ :maxdepth: 2
+
+ fscache
+ object
+ backend-api
+ cachefiles
+ netfs-api
+ operations
diff --git a/Documentation/filesystems/caching/netfs-api.txt b/Documentation/filesystems/caching/netfs-api.rst
similarity index 91%
rename from Documentation/filesystems/caching/netfs-api.txt
rename to Documentation/filesystems/caching/netfs-api.rst
index ba968e8..d9f14b8 100644
--- a/Documentation/filesystems/caching/netfs-api.txt
+++ b/Documentation/filesystems/caching/netfs-api.rst
@@ -1,6 +1,8 @@
- ===============================
- FS-CACHE NETWORK FILESYSTEM API
- ===============================
+.. SPDX-License-Identifier: GPL-2.0
+
+===============================
+FS-Cache Network Filesystem API
+===============================
There's an API by which a network filesystem can make use of the FS-Cache
facilities. This is based around a number of principles:
@@ -19,7 +21,7 @@
This API is declared in <linux/fscache.h>.
-This document contains the following sections:
+.. This document contains the following sections:
(1) Network filesystem definition
(2) Index definition
@@ -41,12 +43,11 @@
(18) FS-Cache specific page flags.
-=============================
-NETWORK FILESYSTEM DEFINITION
+Network Filesystem Definition
=============================
FS-Cache needs a description of the network filesystem. This is specified
-using a record of the following structure:
+using a record of the following structure::
struct fscache_netfs {
uint32_t version;
@@ -71,7 +72,7 @@
another parameter passed into the registration function.
For example, kAFS (linux/fs/afs/) uses the following definitions to describe
-itself:
+itself::
struct fscache_netfs afs_cache_netfs = {
.version = 0,
@@ -79,8 +80,7 @@
};
-================
-INDEX DEFINITION
+Index Definition
================
Indices are used for two purposes:
@@ -114,11 +114,10 @@
function is recursive. Too many layers will run the kernel out of stack.
-=================
-OBJECT DEFINITION
+Object Definition
=================
-To define an object, a structure of the following type should be filled out:
+To define an object, a structure of the following type should be filled out::
struct fscache_cookie_def
{
@@ -149,16 +148,13 @@
This is one of the following values:
- (*) FSCACHE_COOKIE_TYPE_INDEX
-
+ FSCACHE_COOKIE_TYPE_INDEX
This defines an index, which is a special FS-Cache type.
- (*) FSCACHE_COOKIE_TYPE_DATAFILE
-
+ FSCACHE_COOKIE_TYPE_DATAFILE
This defines an ordinary data file.
- (*) Any other value between 2 and 255
-
+ Any other value between 2 and 255
This defines an extraordinary object such as an XATTR.
(2) The name of the object type (NUL terminated unless all 16 chars are used)
@@ -192,9 +188,14 @@
If present, the function should return one of the following values:
- (*) FSCACHE_CHECKAUX_OKAY - the entry is okay as is
- (*) FSCACHE_CHECKAUX_NEEDS_UPDATE - the entry requires update
- (*) FSCACHE_CHECKAUX_OBSOLETE - the entry should be deleted
+ FSCACHE_CHECKAUX_OKAY
+ - the entry is okay as is
+
+ FSCACHE_CHECKAUX_NEEDS_UPDATE
+ - the entry requires update
+
+ FSCACHE_CHECKAUX_OBSOLETE
+ - the entry should be deleted
This function can also be used to extract data from the auxiliary data in
the cache and copy it into the netfs's structures.
@@ -236,32 +237,30 @@
This function is not required for indices as they're not permitted data.
-===================================
-NETWORK FILESYSTEM (UN)REGISTRATION
+Network Filesystem (Un)registration
===================================
The first step is to declare the network filesystem to the cache. This also
involves specifying the layout of the primary index (for AFS, this would be the
"cell" level).
-The registration function is:
+The registration function is::
int fscache_register_netfs(struct fscache_netfs *netfs);
It just takes a pointer to the netfs definition. It returns 0 or an error as
appropriate.
-For kAFS, registration is done as follows:
+For kAFS, registration is done as follows::
ret = fscache_register_netfs(&afs_cache_netfs);
-The last step is, of course, unregistration:
+The last step is, of course, unregistration::
void fscache_unregister_netfs(struct fscache_netfs *netfs);
-================
-CACHE TAG LOOKUP
+Cache Tag Lookup
================
FS-Cache permits the use of more than one cache. To permit particular index
@@ -270,7 +269,7 @@
FS-Cache as to which cache should be used. The problem with doing that is that
FS-Cache will always pick the first cache that was registered.
-To get the representation for a named tag:
+To get the representation for a named tag::
struct fscache_cache_tag *fscache_lookup_cache_tag(const char *name);
@@ -278,7 +277,7 @@
will never return an error. It may return a dummy tag, however, if it runs out
of memory; this will inhibit caching with this tag.
-Any representation so obtained must be released by passing it to this function:
+Any representation so obtained must be released by passing it to this function::
void fscache_release_cache_tag(struct fscache_cache_tag *tag);
@@ -286,13 +285,12 @@
operation select_cache().
-==================
-INDEX REGISTRATION
+Index Registration
==================
The third step is to inform FS-Cache about part of an index hierarchy that can
be used to locate files. This is done by requesting a cookie for each index in
-the path to the file:
+the path to the file::
struct fscache_cookie *
fscache_acquire_cookie(struct fscache_cookie *parent,
@@ -339,7 +337,7 @@
calling fscache_enable_cookie() (see below).
For example, with AFS, a cell would be added to the primary index. This index
-entry would have a dependent inode containing volume mappings within this cell:
+entry would have a dependent inode containing volume mappings within this cell::
cell->cache =
fscache_acquire_cookie(afs_cache_netfs.primary_index,
@@ -349,7 +347,7 @@
cell, 0, true);
And then a particular volume could be added to that index by ID, creating
-another index for vnodes (AFS inode equivalents):
+another index for vnodes (AFS inode equivalents)::
volume->cache =
fscache_acquire_cookie(volume->cell->cache,
@@ -359,13 +357,12 @@
volume, 0, true);
-======================
-DATA FILE REGISTRATION
+Data File Registration
======================
The fourth step is to request a data file be created in the cache. This is
identical to index cookie acquisition. The only difference is that the type in
-the object definition should be something other than index type.
+the object definition should be something other than index type::
vnode->cache =
fscache_acquire_cookie(volume->cache,
@@ -375,15 +372,14 @@
vnode, vnode->status.size, true);
-=================================
-MISCELLANEOUS OBJECT REGISTRATION
+Miscellaneous Object Registration
=================================
An optional step is to request an object of miscellaneous type be created in
the cache. This is almost identical to index cookie acquisition. The only
difference is that the type in the object definition should be something other
than index type. While the parent object could be an index, it's more likely
-it would be some other type of object such as a data file.
+it would be some other type of object such as a data file::
xattr->cache =
fscache_acquire_cookie(vnode->cache,
@@ -396,13 +392,12 @@
entries for example.
-==========================
-SETTING THE DATA FILE SIZE
+Setting the Data File Size
==========================
The fifth step is to set the physical attributes of the file, such as its size.
This doesn't automatically reserve any space in the cache, but permits the
-cache to adjust its metadata for data tracking appropriately:
+cache to adjust its metadata for data tracking appropriately::
int fscache_attr_changed(struct fscache_cookie *cookie);
@@ -417,8 +412,7 @@
to the caller. The attribute adjustment excludes read and write operations.
-=====================
-PAGE ALLOC/READ/WRITE
+Page alloc/read/write
=====================
And the sixth step is to store and retrieve pages in the cache. There are
@@ -441,7 +435,7 @@
Firstly, the netfs should ask FS-Cache to examine the caches and read the
contents cached for a particular page of a particular file if present, or else
-allocate space to store the contents if not:
+allocate space to store the contents if not::
typedef
void (*fscache_rw_complete_t)(struct page *page,
@@ -474,14 +468,14 @@
(4) When the read is complete, end_io_func() will be invoked with:
- (*) The netfs data supplied when the cookie was created.
+ * The netfs data supplied when the cookie was created.
- (*) The page descriptor.
+ * The page descriptor.
- (*) The context argument passed to the above function. This will be
+ * The context argument passed to the above function. This will be
maintained with the get_context/put_context functions mentioned above.
- (*) An argument that's 0 on success or negative for an error code.
+ * An argument that's 0 on success or negative for an error code.
If an error occurs, it should be assumed that the page contains no usable
data. fscache_readpages_cancel() may need to be called.
@@ -504,11 +498,11 @@
read any data from the cache.
-PAGE ALLOCATE
+Page Allocate
-------------
Alternatively, if there's not expected to be any data in the cache for a page
-because the file has been extended, a block can simply be allocated instead:
+because the file has been extended, a block can simply be allocated instead::
int fscache_alloc_page(struct fscache_cookie *cookie,
struct page *page,
@@ -523,12 +517,12 @@
successful.
-PAGE WRITE
+Page Write
----------
Secondly, if the netfs changes the contents of the page (either due to an
initial download or if a user performs a write), then the page should be
-written back to the cache:
+written back to the cache::
int fscache_write_page(struct fscache_cookie *cookie,
struct page *page,
@@ -566,11 +560,11 @@
Writing takes place asynchronously.
-MULTIPLE PAGE READ
+Multiple Page Read
------------------
A facility is provided to read several pages at once, as requested by the
-readpages() address space operation:
+readpages() address space operation::
int fscache_read_or_alloc_pages(struct fscache_cookie *cookie,
struct address_space *mapping,
@@ -598,7 +592,7 @@
be returned.
Otherwise, if all pages had reads dispatched, then 0 will be returned, the
- list will be empty and *nr_pages will be 0.
+ list will be empty and ``*nr_pages`` will be 0.
(4) end_io_func will be called once for each page being read as the reads
complete. It will be called in process context if error != 0, but it may
@@ -609,13 +603,13 @@
been marked appropriately and will need uncaching.
-CANCELLATION OF UNREAD PAGES
+Cancellation of Unread Pages
----------------------------
If one or more pages are passed to fscache_read_or_alloc_pages() but not then
read from the cache and also not read from the underlying filesystem then
those pages will need to have any marks and reservations removed. This can be
-done by calling:
+done by calling::
void fscache_readpages_cancel(struct fscache_cookie *cookie,
struct list_head *pages);
@@ -625,11 +619,10 @@
and any that have PG_fscache set will be uncached.
-==============
-PAGE UNCACHING
+Page Uncaching
==============
-To uncache a page, this function should be called:
+To uncache a page, this function should be called::
void fscache_uncache_page(struct fscache_cookie *cookie,
struct page *page);
@@ -644,12 +637,12 @@
Furthermore, note that this does not cancel the asynchronous read or write
operation started by the read/alloc and write functions, so the page
-invalidation functions must use:
+invalidation functions must use::
bool fscache_check_page_write(struct fscache_cookie *cookie,
struct page *page);
-to see if a page is being written to the cache, and:
+to see if a page is being written to the cache, and::
void fscache_wait_on_page_write(struct fscache_cookie *cookie,
struct page *page);
@@ -660,7 +653,7 @@
When releasepage() is being implemented, a special FS-Cache function exists to
manage the heuristics of coping with vmscan trying to eject pages, which may
conflict with the cache trying to write pages to the cache (which may itself
-need to allocate memory):
+need to allocate memory)::
bool fscache_maybe_release_page(struct fscache_cookie *cookie,
struct page *page,
@@ -676,12 +669,12 @@
in which case the page will not be stored in the cache this time.
-BULK INODE PAGE UNCACHE
+Bulk Image Page Uncache
-----------------------
A convenience routine is provided to perform an uncache on all the pages
attached to an inode. This assumes that the pages on the inode correspond on a
-1:1 basis with the pages in the cache.
+1:1 basis with the pages in the cache::
void fscache_uncache_all_inode_pages(struct fscache_cookie *cookie,
struct inode *inode);
@@ -692,12 +685,11 @@
error is returned.
-===============================
-INDEX AND DATA FILE CONSISTENCY
+Index and Data File consistency
===============================
To find out whether auxiliary data for an object is up to data within the
-cache, the following function can be called:
+cache, the following function can be called::
int fscache_check_consistency(struct fscache_cookie *cookie,
const void *aux_data);
@@ -708,7 +700,7 @@
return -ENOMEM and -ERESTARTSYS.
To request an update of the index data for an index or other object, the
-following function should be called:
+following function should be called::
void fscache_update_cookie(struct fscache_cookie *cookie,
const void *aux_data);
@@ -721,8 +713,7 @@
data blocks are added to a data file object.
-=================
-COOKIE ENABLEMENT
+Cookie Enablement
=================
Cookies exist in one of two states: enabled and disabled. If a cookie is
@@ -731,7 +722,7 @@
still possible to uncache pages and relinquish the cookie.
The initial enablement state is set by fscache_acquire_cookie(), but the cookie
-can be enabled or disabled later. To disable a cookie, call:
+can be enabled or disabled later. To disable a cookie, call::
void fscache_disable_cookie(struct fscache_cookie *cookie,
const void *aux_data,
@@ -746,7 +737,7 @@
calling fscache_uncache_all_inode_pages() afterwards to make sure all page
markings are cleared up.
-Cookies can be enabled or reenabled with:
+Cookies can be enabled or reenabled with::
void fscache_enable_cookie(struct fscache_cookie *cookie,
const void *aux_data,
@@ -771,13 +762,12 @@
that is non-NULL inside the enablement lock before proceeding.
-===============================
-MISCELLANEOUS COOKIE OPERATIONS
+Miscellaneous Cookie operations
===============================
There are a number of operations that can be used to control cookies:
- (*) Cookie pinning:
+ * Cookie pinning::
int fscache_pin_cookie(struct fscache_cookie *cookie);
void fscache_unpin_cookie(struct fscache_cookie *cookie);
@@ -790,7 +780,7 @@
-ENOSPC if there isn't enough space to honour the operation, -ENOMEM or
-EIO if there's any other problem.
- (*) Data space reservation:
+ * Data space reservation::
int fscache_reserve_space(struct fscache_cookie *cookie, loff_t size);
@@ -809,11 +799,10 @@
make space if it's not in use.
-=====================
-COOKIE UNREGISTRATION
+Cookie Unregistration
=====================
-To get rid of a cookie, this function should be called.
+To get rid of a cookie, this function should be called::
void fscache_relinquish_cookie(struct fscache_cookie *cookie,
const void *aux_data,
@@ -835,16 +824,14 @@
first.
-==================
-INDEX INVALIDATION
+Index Invalidation
==================
There is no direct way to invalidate an index subtree. To do this, the caller
should relinquish and retire the cookie they have, and then acquire a new one.
-======================
-DATA FILE INVALIDATION
+Data File Invalidation
======================
Sometimes it will be necessary to invalidate an object that contains data.
@@ -853,7 +840,7 @@
inode and reload from the server.
To indicate that a cache object should be invalidated, the following function
-can be called:
+can be called::
void fscache_invalidate(struct fscache_cookie *cookie);
@@ -868,13 +855,12 @@
Using the following function, the netfs can wait for the invalidation operation
to have reached a point at which it can start submitting ordinary operations
-once again:
+once again::
void fscache_wait_on_invalidate(struct fscache_cookie *cookie);
-===========================
-FS-CACHE SPECIFIC PAGE FLAG
+FS-cache Specific Page Flag
===========================
FS-Cache makes use of a page flag, PG_private_2, for its own purpose. This is
@@ -898,7 +884,7 @@
This bit does not overlap with such as PG_private. This means that FS-Cache
can be used with a filesystem that uses the block buffering code.
-There are a number of operations defined on this flag:
+There are a number of operations defined on this flag::
int PageFsCache(struct page *page);
void SetPageFsCache(struct page *page)
diff --git a/Documentation/filesystems/caching/object.txt b/Documentation/filesystems/caching/object.rst
similarity index 95%
rename from Documentation/filesystems/caching/object.txt
rename to Documentation/filesystems/caching/object.rst
index 100ff41..ce0e043 100644
--- a/Documentation/filesystems/caching/object.txt
+++ b/Documentation/filesystems/caching/object.rst
@@ -1,10 +1,12 @@
- ====================================================
- IN-KERNEL CACHE OBJECT REPRESENTATION AND MANAGEMENT
- ====================================================
+.. SPDX-License-Identifier: GPL-2.0
+
+====================================================
+In-Kernel Cache Object Representation and Management
+====================================================
By: David Howells <dhowells@redhat.com>
-Contents:
+.. Contents:
(*) Representation
@@ -18,8 +20,7 @@
(*) The set of events.
-==============
-REPRESENTATION
+Representation
==============
FS-Cache maintains an in-kernel representation of each object that a netfs is
@@ -38,7 +39,7 @@
Furthermore, both cookies and objects are hierarchical. The two hierarchies
correspond, but the cookies tree is a superset of the union of the object trees
-of multiple caches:
+of multiple caches::
NETFS INDEX TREE : CACHE 1 : CACHE 2
: :
@@ -89,8 +90,7 @@
those cookies are hidden from it.
-===============================
-OBJECT MANAGEMENT STATE MACHINE
+Object Management State Machine
===============================
Within FS-Cache, each active object is managed by its own individual state
@@ -124,7 +124,7 @@
fscache_enqueue_object()).
-PROVISION OF CPU TIME
+Provision of CPU Time
---------------------
The work to be done by the various states was given CPU time by the threads of
@@ -141,7 +141,7 @@
workqueues don't necessarily have the right numbers of threads.
-LOCKING SIMPLIFICATION
+Locking Simplification
----------------------
Because only one worker thread may be operating on any particular object's
@@ -151,8 +151,7 @@
requested from either end.
-=================
-THE SET OF STATES
+The Set of States
=================
The object state machine has a set of states that it can be in. There are
@@ -275,19 +274,17 @@
this state.
-THE SET OF EVENTS
+The Set of Events
-----------------
There are a number of events that can be raised to an object state machine:
- (*) FSCACHE_OBJECT_EV_UPDATE
-
+ FSCACHE_OBJECT_EV_UPDATE
The netfs requested that an object be updated. The state machine will ask
the cache backend to update the object, and the cache backend will ask the
netfs for details of the change through its cookie definition ops.
- (*) FSCACHE_OBJECT_EV_CLEARED
-
+ FSCACHE_OBJECT_EV_CLEARED
This is signalled in two circumstances:
(a) when an object's last child object is dropped and
@@ -296,20 +293,16 @@
This is used to proceed from the dying state.
- (*) FSCACHE_OBJECT_EV_ERROR
-
+ FSCACHE_OBJECT_EV_ERROR
This is signalled when an I/O error occurs during the processing of some
object.
- (*) FSCACHE_OBJECT_EV_RELEASE
- (*) FSCACHE_OBJECT_EV_RETIRE
-
+ FSCACHE_OBJECT_EV_RELEASE, FSCACHE_OBJECT_EV_RETIRE
These are signalled when the netfs relinquishes a cookie it was using.
The event selected depends on whether the netfs asks for the backing
object to be retired (deleted) or retained.
- (*) FSCACHE_OBJECT_EV_WITHDRAW
-
+ FSCACHE_OBJECT_EV_WITHDRAW
This is signalled when the cache backend wants to withdraw an object.
This means that the object will have to be detached from the netfs's
cookie.
diff --git a/Documentation/filesystems/caching/operations.txt b/Documentation/filesystems/caching/operations.rst
similarity index 89%
rename from Documentation/filesystems/caching/operations.txt
rename to Documentation/filesystems/caching/operations.rst
index d8976c4..f7ddcc0 100644
--- a/Documentation/filesystems/caching/operations.txt
+++ b/Documentation/filesystems/caching/operations.rst
@@ -1,10 +1,12 @@
- ================================
- ASYNCHRONOUS OPERATIONS HANDLING
- ================================
+.. SPDX-License-Identifier: GPL-2.0
+
+================================
+Asynchronous Operations Handling
+================================
By: David Howells <dhowells@redhat.com>
-Contents:
+.. Contents:
(*) Overview.
@@ -17,8 +19,7 @@
(*) Asynchronous callback.
-========
-OVERVIEW
+Overview
========
FS-Cache has an asynchronous operations handling facility that it uses for its
@@ -33,11 +34,10 @@
To make use of this facility, <linux/fscache-cache.h> should be #included.
-===============================
-OPERATION RECORD INITIALISATION
+Operation Record Initialisation
===============================
-An operation is recorded in an fscache_operation struct:
+An operation is recorded in an fscache_operation struct::
struct fscache_operation {
union {
@@ -50,7 +50,7 @@
};
Someone wanting to issue an operation should allocate something with this
-struct embedded in it. They should initialise it by calling:
+struct embedded in it. They should initialise it by calling::
void fscache_operation_init(struct fscache_operation *op,
fscache_operation_release_t release);
@@ -67,8 +67,7 @@
operation and waited for afterwards.
-==========
-PARAMETERS
+Parameters
==========
There are a number of parameters that can be set in the operation record's flag
@@ -87,7 +86,7 @@
If this option is to be used, FSCACHE_OP_WAITING must be set in op->flags
before submitting the operation, and the operating thread must wait for it
- to be cleared before proceeding:
+ to be cleared before proceeding::
wait_on_bit(&op->flags, FSCACHE_OP_WAITING,
TASK_UNINTERRUPTIBLE);
@@ -101,7 +100,7 @@
page to a netfs page after the backing fs has read the page in.
If this option is used, op->fast_work and op->processor must be
- initialised before submitting the operation:
+ initialised before submitting the operation::
INIT_WORK(&op->fast_work, do_some_work);
@@ -114,7 +113,7 @@
pages that have just been fetched from a remote server.
If this option is used, op->slow_work and op->processor must be
- initialised before submitting the operation:
+ initialised before submitting the operation::
fscache_operation_init_slow(op, processor)
@@ -132,8 +131,7 @@
operations running at the same time.
-=========
-PROCEDURE
+Procedure
=========
Operations are used through the following procedure:
@@ -143,7 +141,7 @@
generic op embedded within.
(2) The submitting thread must then submit the operation for processing using
- one of the following two functions:
+ one of the following two functions::
int fscache_submit_op(struct fscache_object *object,
struct fscache_operation *op);
@@ -164,7 +162,7 @@
operation of conflicting exclusivity is in progress on the object.
If the operation is asynchronous, the manager will retain a reference to
- it, so the caller should put their reference to it by passing it to:
+ it, so the caller should put their reference to it by passing it to::
void fscache_put_operation(struct fscache_operation *op);
@@ -179,12 +177,12 @@
(4) The operation holds an effective lock upon the object, preventing other
exclusive ops conflicting until it is released. The operation can be
enqueued for further immediate asynchronous processing by adjusting the
- CPU time provisioning option if necessary, eg:
+ CPU time provisioning option if necessary, eg::
op->flags &= ~FSCACHE_OP_TYPE;
op->flags |= ~FSCACHE_OP_FAST;
- and calling:
+ and calling::
void fscache_enqueue_operation(struct fscache_operation *op)
@@ -192,13 +190,12 @@
pools.
-=====================
-ASYNCHRONOUS CALLBACK
+Asynchronous Callback
=====================
When used in asynchronous mode, the worker thread pool will invoke the
processor method with a pointer to the operation. This should then get at the
-container struct by using container_of():
+container struct by using container_of()::
static void fscache_write_op(struct fscache_operation *_op)
{
diff --git a/Documentation/filesystems/cifs/cifsroot.txt b/Documentation/filesystems/cifs/cifsroot.rst
similarity index 71%
rename from Documentation/filesystems/cifs/cifsroot.txt
rename to Documentation/filesystems/cifs/cifsroot.rst
index 947b7ec..4930bb4 100644
--- a/Documentation/filesystems/cifs/cifsroot.txt
+++ b/Documentation/filesystems/cifs/cifsroot.rst
@@ -1,7 +1,11 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===========================================
Mounting root file system via SMB (cifs.ko)
===========================================
Written 2019 by Paulo Alcantara <palcantara@suse.de>
+
Written 2019 by Aurelien Aptel <aaptel@suse.com>
The CONFIG_CIFS_ROOT option enables experimental root file system
@@ -32,7 +36,7 @@
====================
To enable SMB1+UNIX extensions you will need to set these global
-settings in Samba smb.conf:
+settings in Samba smb.conf::
[global]
server min protocol = NT1
@@ -41,12 +45,16 @@
Kernel command line
===================
-root=/dev/cifs
+::
+
+ root=/dev/cifs
This is just a virtual device that basically tells the kernel to mount
the root file system via SMB protocol.
-cifsroot=//<server-ip>/<share>[,options]
+::
+
+ cifsroot=//<server-ip>/<share>[,options]
Enables the kernel to mount the root file system via SMB that are
located in the <server-ip> and <share> specified in this option.
@@ -65,33 +73,33 @@
Examples
========
-Export root file system as a Samba share in smb.conf file.
+Export root file system as a Samba share in smb.conf file::
-...
-[linux]
- path = /path/to/rootfs
- read only = no
- guest ok = yes
- force user = root
- force group = root
- browseable = yes
- writeable = yes
- admin users = root
- public = yes
- create mask = 0777
- directory mask = 0777
-...
+ ...
+ [linux]
+ path = /path/to/rootfs
+ read only = no
+ guest ok = yes
+ force user = root
+ force group = root
+ browseable = yes
+ writeable = yes
+ admin users = root
+ public = yes
+ create mask = 0777
+ directory mask = 0777
+ ...
-Restart smb service.
+Restart smb service::
-# systemctl restart smb
+ # systemctl restart smb
Test it under QEMU on a kernel built with CONFIG_CIFS_ROOT and
-CONFIG_IP_PNP options enabled.
+CONFIG_IP_PNP options enabled::
-# qemu-system-x86_64 -enable-kvm -cpu host -m 1024 \
- -kernel /path/to/linux/arch/x86/boot/bzImage -nographic \
- -append "root=/dev/cifs rw ip=dhcp cifsroot=//10.0.2.2/linux,username=foo,password=bar console=ttyS0 3"
+ # qemu-system-x86_64 -enable-kvm -cpu host -m 1024 \
+ -kernel /path/to/linux/arch/x86/boot/bzImage -nographic \
+ -append "root=/dev/cifs rw ip=dhcp cifsroot=//10.0.2.2/linux,username=foo,password=bar console=ttyS0 3"
1: https://wiki.samba.org/index.php/UNIX_Extensions
diff --git a/Documentation/filesystems/coda.rst b/Documentation/filesystems/coda.rst
new file mode 100644
index 0000000..84c860c
--- /dev/null
+++ b/Documentation/filesystems/coda.rst
@@ -0,0 +1,1670 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===========================
+Coda Kernel-Venus Interface
+===========================
+
+.. Note::
+
+ This is one of the technical documents describing a component of
+ Coda -- this document describes the client kernel-Venus interface.
+
+For more information:
+
+ http://www.coda.cs.cmu.edu
+
+For user level software needed to run Coda:
+
+ ftp://ftp.coda.cs.cmu.edu
+
+To run Coda you need to get a user level cache manager for the client,
+named Venus, as well as tools to manipulate ACLs, to log in, etc. The
+client needs to have the Coda filesystem selected in the kernel
+configuration.
+
+The server needs a user level server and at present does not depend on
+kernel support.
+
+ The Venus kernel interface
+
+ Peter J. Braam
+
+ v1.0, Nov 9, 1997
+
+ This document describes the communication between Venus and kernel
+ level filesystem code needed for the operation of the Coda file sys-
+ tem. This document version is meant to describe the current interface
+ (version 1.0) as well as improvements we envisage.
+
+.. Table of Contents
+
+ 1. Introduction
+
+ 2. Servicing Coda filesystem calls
+
+ 3. The message layer
+
+ 3.1 Implementation details
+
+ 4. The interface at the call level
+
+ 4.1 Data structures shared by the kernel and Venus
+ 4.2 The pioctl interface
+ 4.3 root
+ 4.4 lookup
+ 4.5 getattr
+ 4.6 setattr
+ 4.7 access
+ 4.8 create
+ 4.9 mkdir
+ 4.10 link
+ 4.11 symlink
+ 4.12 remove
+ 4.13 rmdir
+ 4.14 readlink
+ 4.15 open
+ 4.16 close
+ 4.17 ioctl
+ 4.18 rename
+ 4.19 readdir
+ 4.20 vget
+ 4.21 fsync
+ 4.22 inactive
+ 4.23 rdwr
+ 4.24 odymount
+ 4.25 ody_lookup
+ 4.26 ody_expand
+ 4.27 prefetch
+ 4.28 signal
+
+ 5. The minicache and downcalls
+
+ 5.1 INVALIDATE
+ 5.2 FLUSH
+ 5.3 PURGEUSER
+ 5.4 ZAPFILE
+ 5.5 ZAPDIR
+ 5.6 ZAPVNODE
+ 5.7 PURGEFID
+ 5.8 REPLACE
+
+ 6. Initialization and cleanup
+
+ 6.1 Requirements
+
+1. Introduction
+===============
+
+ A key component in the Coda Distributed File System is the cache
+ manager, Venus.
+
+ When processes on a Coda enabled system access files in the Coda
+ filesystem, requests are directed at the filesystem layer in the
+ operating system. The operating system will communicate with Venus to
+ service the request for the process. Venus manages a persistent
+ client cache and makes remote procedure calls to Coda file servers and
+ related servers (such as authentication servers) to service these
+ requests it receives from the operating system. When Venus has
+ serviced a request it replies to the operating system with appropriate
+ return codes, and other data related to the request. Optionally the
+ kernel support for Coda may maintain a minicache of recently processed
+ requests to limit the number of interactions with Venus. Venus
+ possesses the facility to inform the kernel when elements from its
+ minicache are no longer valid.
+
+ This document describes precisely this communication between the
+ kernel and Venus. The definitions of so called upcalls and downcalls
+ will be given with the format of the data they handle. We shall also
+ describe the semantic invariants resulting from the calls.
+
+ Historically Coda was implemented in a BSD file system in Mach 2.6.
+ The interface between the kernel and Venus is very similar to the BSD
+ VFS interface. Similar functionality is provided, and the format of
+ the parameters and returned data is very similar to the BSD VFS. This
+ leads to an almost natural environment for implementing a kernel-level
+ filesystem driver for Coda in a BSD system. However, other operating
+ systems such as Linux and Windows 95 and NT have virtual filesystem
+ with different interfaces.
+
+ To implement Coda on these systems some reverse engineering of the
+ Venus/Kernel protocol is necessary. Also it came to light that other
+ systems could profit significantly from certain small optimizations
+ and modifications to the protocol. To facilitate this work as well as
+ to make future ports easier, communication between Venus and the
+ kernel should be documented in great detail. This is the aim of this
+ document.
+
+2. Servicing Coda filesystem calls
+===================================
+
+ The service of a request for a Coda file system service originates in
+ a process P which accessing a Coda file. It makes a system call which
+ traps to the OS kernel. Examples of such calls trapping to the kernel
+ are ``read``, ``write``, ``open``, ``close``, ``create``, ``mkdir``,
+ ``rmdir``, ``chmod`` in a Unix ontext. Similar calls exist in the Win32
+ environment, and are named ``CreateFile``.
+
+ Generally the operating system handles the request in a virtual
+ filesystem (VFS) layer, which is named I/O Manager in NT and IFS
+ manager in Windows 95. The VFS is responsible for partial processing
+ of the request and for locating the specific filesystem(s) which will
+ service parts of the request. Usually the information in the path
+ assists in locating the correct FS drivers. Sometimes after extensive
+ pre-processing, the VFS starts invoking exported routines in the FS
+ driver. This is the point where the FS specific processing of the
+ request starts, and here the Coda specific kernel code comes into
+ play.
+
+ The FS layer for Coda must expose and implement several interfaces.
+ First and foremost the VFS must be able to make all necessary calls to
+ the Coda FS layer, so the Coda FS driver must expose the VFS interface
+ as applicable in the operating system. These differ very significantly
+ among operating systems, but share features such as facilities to
+ read/write and create and remove objects. The Coda FS layer services
+ such VFS requests by invoking one or more well defined services
+ offered by the cache manager Venus. When the replies from Venus have
+ come back to the FS driver, servicing of the VFS call continues and
+ finishes with a reply to the kernel's VFS. Finally the VFS layer
+ returns to the process.
+
+ As a result of this design a basic interface exposed by the FS driver
+ must allow Venus to manage message traffic. In particular Venus must
+ be able to retrieve and place messages and to be notified of the
+ arrival of a new message. The notification must be through a mechanism
+ which does not block Venus since Venus must attend to other tasks even
+ when no messages are waiting or being processed.
+
+ **Interfaces of the Coda FS Driver**
+
+ Furthermore the FS layer provides for a special path of communication
+ between a user process and Venus, called the pioctl interface. The
+ pioctl interface is used for Coda specific services, such as
+ requesting detailed information about the persistent cache managed by
+ Venus. Here the involvement of the kernel is minimal. It identifies
+ the calling process and passes the information on to Venus. When
+ Venus replies the response is passed back to the caller in unmodified
+ form.
+
+ Finally Venus allows the kernel FS driver to cache the results from
+ certain services. This is done to avoid excessive context switches
+ and results in an efficient system. However, Venus may acquire
+ information, for example from the network which implies that cached
+ information must be flushed or replaced. Venus then makes a downcall
+ to the Coda FS layer to request flushes or updates in the cache. The
+ kernel FS driver handles such requests synchronously.
+
+ Among these interfaces the VFS interface and the facility to place,
+ receive and be notified of messages are platform specific. We will
+ not go into the calls exported to the VFS layer but we will state the
+ requirements of the message exchange mechanism.
+
+
+3. The message layer
+=====================
+
+ At the lowest level the communication between Venus and the FS driver
+ proceeds through messages. The synchronization between processes
+ requesting Coda file service and Venus relies on blocking and waking
+ up processes. The Coda FS driver processes VFS- and pioctl-requests
+ on behalf of a process P, creates messages for Venus, awaits replies
+ and finally returns to the caller. The implementation of the exchange
+ of messages is platform specific, but the semantics have (so far)
+ appeared to be generally applicable. Data buffers are created by the
+ FS Driver in kernel memory on behalf of P and copied to user memory in
+ Venus.
+
+ The FS Driver while servicing P makes upcalls to Venus. Such an
+ upcall is dispatched to Venus by creating a message structure. The
+ structure contains the identification of P, the message sequence
+ number, the size of the request and a pointer to the data in kernel
+ memory for the request. Since the data buffer is re-used to hold the
+ reply from Venus, there is a field for the size of the reply. A flags
+ field is used in the message to precisely record the status of the
+ message. Additional platform dependent structures involve pointers to
+ determine the position of the message on queues and pointers to
+ synchronization objects. In the upcall routine the message structure
+ is filled in, flags are set to 0, and it is placed on the *pending*
+ queue. The routine calling upcall is responsible for allocating the
+ data buffer; its structure will be described in the next section.
+
+ A facility must exist to notify Venus that the message has been
+ created, and implemented using available synchronization objects in
+ the OS. This notification is done in the upcall context of the process
+ P. When the message is on the pending queue, process P cannot proceed
+ in upcall. The (kernel mode) processing of P in the filesystem
+ request routine must be suspended until Venus has replied. Therefore
+ the calling thread in P is blocked in upcall. A pointer in the
+ message structure will locate the synchronization object on which P is
+ sleeping.
+
+ Venus detects the notification that a message has arrived, and the FS
+ driver allow Venus to retrieve the message with a getmsg_from_kernel
+ call. This action finishes in the kernel by putting the message on the
+ queue of processing messages and setting flags to READ. Venus is
+ passed the contents of the data buffer. The getmsg_from_kernel call
+ now returns and Venus processes the request.
+
+ At some later point the FS driver receives a message from Venus,
+ namely when Venus calls sendmsg_to_kernel. At this moment the Coda FS
+ driver looks at the contents of the message and decides if:
+
+
+ * the message is a reply for a suspended thread P. If so it removes
+ the message from the processing queue and marks the message as
+ WRITTEN. Finally, the FS driver unblocks P (still in the kernel
+ mode context of Venus) and the sendmsg_to_kernel call returns to
+ Venus. The process P will be scheduled at some point and continues
+ processing its upcall with the data buffer replaced with the reply
+ from Venus.
+
+ * The message is a ``downcall``. A downcall is a request from Venus to
+ the FS Driver. The FS driver processes the request immediately
+ (usually a cache eviction or replacement) and when it finishes
+ sendmsg_to_kernel returns.
+
+ Now P awakes and continues processing upcall. There are some
+ subtleties to take account of. First P will determine if it was woken
+ up in upcall by a signal from some other source (for example an
+ attempt to terminate P) or as is normally the case by Venus in its
+ sendmsg_to_kernel call. In the normal case, the upcall routine will
+ deallocate the message structure and return. The FS routine can proceed
+ with its processing.
+
+
+ **Sleeping and IPC arrangements**
+
+ In case P is woken up by a signal and not by Venus, it will first look
+ at the flags field. If the message is not yet READ, the process P can
+ handle its signal without notifying Venus. If Venus has READ, and
+ the request should not be processed, P can send Venus a signal message
+ to indicate that it should disregard the previous message. Such
+ signals are put in the queue at the head, and read first by Venus. If
+ the message is already marked as WRITTEN it is too late to stop the
+ processing. The VFS routine will now continue. (-- If a VFS request
+ involves more than one upcall, this can lead to complicated state, an
+ extra field "handle_signals" could be added in the message structure
+ to indicate points of no return have been passed.--)
+
+
+
+3.1. Implementation details
+----------------------------
+
+ The Unix implementation of this mechanism has been through the
+ implementation of a character device associated with Coda. Venus
+ retrieves messages by doing a read on the device, replies are sent
+ with a write and notification is through the select system call on the
+ file descriptor for the device. The process P is kept waiting on an
+ interruptible wait queue object.
+
+ In Windows NT and the DPMI Windows 95 implementation a DeviceIoControl
+ call is used. The DeviceIoControl call is designed to copy buffers
+ from user memory to kernel memory with OPCODES. The sendmsg_to_kernel
+ is issued as a synchronous call, while the getmsg_from_kernel call is
+ asynchronous. Windows EventObjects are used for notification of
+ message arrival. The process P is kept waiting on a KernelEvent
+ object in NT and a semaphore in Windows 95.
+
+
+4. The interface at the call level
+===================================
+
+
+ This section describes the upcalls a Coda FS driver can make to Venus.
+ Each of these upcalls make use of two structures: inputArgs and
+ outputArgs. In pseudo BNF form the structures take the following
+ form::
+
+
+ struct inputArgs {
+ u_long opcode;
+ u_long unique; /* Keep multiple outstanding msgs distinct */
+ u_short pid; /* Common to all */
+ u_short pgid; /* Common to all */
+ struct CodaCred cred; /* Common to all */
+
+ <union "in" of call dependent parts of inputArgs>
+ };
+
+ struct outputArgs {
+ u_long opcode;
+ u_long unique; /* Keep multiple outstanding msgs distinct */
+ u_long result;
+
+ <union "out" of call dependent parts of inputArgs>
+ };
+
+
+
+ Before going on let us elucidate the role of the various fields. The
+ inputArgs start with the opcode which defines the type of service
+ requested from Venus. There are approximately 30 upcalls at present
+ which we will discuss. The unique field labels the inputArg with a
+ unique number which will identify the message uniquely. A process and
+ process group id are passed. Finally the credentials of the caller
+ are included.
+
+ Before delving into the specific calls we need to discuss a variety of
+ data structures shared by the kernel and Venus.
+
+
+
+
+4.1. Data structures shared by the kernel and Venus
+----------------------------------------------------
+
+
+ The CodaCred structure defines a variety of user and group ids as
+ they are set for the calling process. The vuid_t and vgid_t are 32 bit
+ unsigned integers. It also defines group membership in an array. On
+ Unix the CodaCred has proven sufficient to implement good security
+ semantics for Coda but the structure may have to undergo modification
+ for the Windows environment when these mature::
+
+ struct CodaCred {
+ vuid_t cr_uid, cr_euid, cr_suid, cr_fsuid; /* Real, effective, set, fs uid */
+ vgid_t cr_gid, cr_egid, cr_sgid, cr_fsgid; /* same for groups */
+ vgid_t cr_groups[NGROUPS]; /* Group membership for caller */
+ };
+
+
+ .. Note::
+
+ It is questionable if we need CodaCreds in Venus. Finally Venus
+ doesn't know about groups, although it does create files with the
+ default uid/gid. Perhaps the list of group membership is superfluous.
+
+
+ The next item is the fundamental identifier used to identify Coda
+ files, the ViceFid. A fid of a file uniquely defines a file or
+ directory in the Coda filesystem within a cell [1]_::
+
+ typedef struct ViceFid {
+ VolumeId Volume;
+ VnodeId Vnode;
+ Unique_t Unique;
+ } ViceFid;
+
+ .. [1] A cell is agroup of Coda servers acting under the aegis of a single
+ system control machine or SCM. See the Coda Administration manual
+ for a detailed description of the role of the SCM.
+
+ Each of the constituent fields: VolumeId, VnodeId and Unique_t are
+ unsigned 32 bit integers. We envisage that a further field will need
+ to be prefixed to identify the Coda cell; this will probably take the
+ form of a Ipv6 size IP address naming the Coda cell through DNS.
+
+ The next important structure shared between Venus and the kernel is
+ the attributes of the file. The following structure is used to
+ exchange information. It has room for future extensions such as
+ support for device files (currently not present in Coda)::
+
+
+ struct coda_timespec {
+ int64_t tv_sec; /* seconds */
+ long tv_nsec; /* nanoseconds */
+ };
+
+ struct coda_vattr {
+ enum coda_vtype va_type; /* vnode type (for create) */
+ u_short va_mode; /* files access mode and type */
+ short va_nlink; /* number of references to file */
+ vuid_t va_uid; /* owner user id */
+ vgid_t va_gid; /* owner group id */
+ long va_fsid; /* file system id (dev for now) */
+ long va_fileid; /* file id */
+ u_quad_t va_size; /* file size in bytes */
+ long va_blocksize; /* blocksize preferred for i/o */
+ struct coda_timespec va_atime; /* time of last access */
+ struct coda_timespec va_mtime; /* time of last modification */
+ struct coda_timespec va_ctime; /* time file changed */
+ u_long va_gen; /* generation number of file */
+ u_long va_flags; /* flags defined for file */
+ dev_t va_rdev; /* device special file represents */
+ u_quad_t va_bytes; /* bytes of disk space held by file */
+ u_quad_t va_filerev; /* file modification number */
+ u_int va_vaflags; /* operations flags, see below */
+ long va_spare; /* remain quad aligned */
+ };
+
+
+4.2. The pioctl interface
+--------------------------
+
+
+ Coda specific requests can be made by application through the pioctl
+ interface. The pioctl is implemented as an ordinary ioctl on a
+ fictitious file /coda/.CONTROL. The pioctl call opens this file, gets
+ a file handle and makes the ioctl call. Finally it closes the file.
+
+ The kernel involvement in this is limited to providing the facility to
+ open and close and pass the ioctl message and to verify that a path in
+ the pioctl data buffers is a file in a Coda filesystem.
+
+ The kernel is handed a data packet of the form::
+
+ struct {
+ const char *path;
+ struct ViceIoctl vidata;
+ int follow;
+ } data;
+
+
+
+ where::
+
+
+ struct ViceIoctl {
+ caddr_t in, out; /* Data to be transferred in, or out */
+ short in_size; /* Size of input buffer <= 2K */
+ short out_size; /* Maximum size of output buffer, <= 2K */
+ };
+
+
+
+ The path must be a Coda file, otherwise the ioctl upcall will not be
+ made.
+
+ .. Note:: The data structures and code are a mess. We need to clean this up.
+
+
+**We now proceed to document the individual calls**:
+
+
+4.3. root
+----------
+
+
+ Arguments
+ in
+
+ empty
+
+ out::
+
+ struct cfs_root_out {
+ ViceFid VFid;
+ } cfs_root;
+
+
+
+ Description
+ This call is made to Venus during the initialization of
+ the Coda filesystem. If the result is zero, the cfs_root structure
+ contains the ViceFid of the root of the Coda filesystem. If a non-zero
+ result is generated, its value is a platform dependent error code
+ indicating the difficulty Venus encountered in locating the root of
+ the Coda filesystem.
+
+4.4. lookup
+------------
+
+
+ Summary
+ Find the ViceFid and type of an object in a directory if it exists.
+
+ Arguments
+ in::
+
+ struct cfs_lookup_in {
+ ViceFid VFid;
+ char *name; /* Place holder for data. */
+ } cfs_lookup;
+
+
+
+ out::
+
+ struct cfs_lookup_out {
+ ViceFid VFid;
+ int vtype;
+ } cfs_lookup;
+
+
+
+ Description
+ This call is made to determine the ViceFid and filetype of
+ a directory entry. The directory entry requested carries name name
+ and Venus will search the directory identified by cfs_lookup_in.VFid.
+ The result may indicate that the name does not exist, or that
+ difficulty was encountered in finding it (e.g. due to disconnection).
+ If the result is zero, the field cfs_lookup_out.VFid contains the
+ targets ViceFid and cfs_lookup_out.vtype the coda_vtype giving the
+ type of object the name designates.
+
+ The name of the object is an 8 bit character string of maximum length
+ CFS_MAXNAMLEN, currently set to 256 (including a 0 terminator.)
+
+ It is extremely important to realize that Venus bitwise ors the field
+ cfs_lookup.vtype with CFS_NOCACHE to indicate that the object should
+ not be put in the kernel name cache.
+
+ .. Note::
+
+ The type of the vtype is currently wrong. It should be
+ coda_vtype. Linux does not take note of CFS_NOCACHE. It should.
+
+
+4.5. getattr
+-------------
+
+
+ Summary Get the attributes of a file.
+
+ Arguments
+ in::
+
+ struct cfs_getattr_in {
+ ViceFid VFid;
+ struct coda_vattr attr; /* XXXXX */
+ } cfs_getattr;
+
+
+
+ out::
+
+ struct cfs_getattr_out {
+ struct coda_vattr attr;
+ } cfs_getattr;
+
+
+
+ Description
+ This call returns the attributes of the file identified by fid.
+
+ Errors
+ Errors can occur if the object with fid does not exist, is
+ unaccessible or if the caller does not have permission to fetch
+ attributes.
+
+ .. Note::
+
+ Many kernel FS drivers (Linux, NT and Windows 95) need to acquire
+ the attributes as well as the Fid for the instantiation of an internal
+ "inode" or "FileHandle". A significant improvement in performance on
+ such systems could be made by combining the lookup and getattr calls
+ both at the Venus/kernel interaction level and at the RPC level.
+
+ The vattr structure included in the input arguments is superfluous and
+ should be removed.
+
+
+4.6. setattr
+-------------
+
+
+ Summary
+ Set the attributes of a file.
+
+ Arguments
+ in::
+
+ struct cfs_setattr_in {
+ ViceFid VFid;
+ struct coda_vattr attr;
+ } cfs_setattr;
+
+
+
+
+ out
+
+ empty
+
+ Description
+ The structure attr is filled with attributes to be changed
+ in BSD style. Attributes not to be changed are set to -1, apart from
+ vtype which is set to VNON. Other are set to the value to be assigned.
+ The only attributes which the FS driver may request to change are the
+ mode, owner, groupid, atime, mtime and ctime. The return value
+ indicates success or failure.
+
+ Errors
+ A variety of errors can occur. The object may not exist, may
+ be inaccessible, or permission may not be granted by Venus.
+
+
+4.7. access
+------------
+
+
+ Arguments
+ in::
+
+ struct cfs_access_in {
+ ViceFid VFid;
+ int flags;
+ } cfs_access;
+
+
+
+ out
+
+ empty
+
+ Description
+ Verify if access to the object identified by VFid for
+ operations described by flags is permitted. The result indicates if
+ access will be granted. It is important to remember that Coda uses
+ ACLs to enforce protection and that ultimately the servers, not the
+ clients enforce the security of the system. The result of this call
+ will depend on whether a token is held by the user.
+
+ Errors
+ The object may not exist, or the ACL describing the protection
+ may not be accessible.
+
+
+4.8. create
+------------
+
+
+ Summary
+ Invoked to create a file
+
+ Arguments
+ in::
+
+ struct cfs_create_in {
+ ViceFid VFid;
+ struct coda_vattr attr;
+ int excl;
+ int mode;
+ char *name; /* Place holder for data. */
+ } cfs_create;
+
+
+
+
+ out::
+
+ struct cfs_create_out {
+ ViceFid VFid;
+ struct coda_vattr attr;
+ } cfs_create;
+
+
+
+ Description
+ This upcall is invoked to request creation of a file.
+ The file will be created in the directory identified by VFid, its name
+ will be name, and the mode will be mode. If excl is set an error will
+ be returned if the file already exists. If the size field in attr is
+ set to zero the file will be truncated. The uid and gid of the file
+ are set by converting the CodaCred to a uid using a macro CRTOUID
+ (this macro is platform dependent). Upon success the VFid and
+ attributes of the file are returned. The Coda FS Driver will normally
+ instantiate a vnode, inode or file handle at kernel level for the new
+ object.
+
+
+ Errors
+ A variety of errors can occur. Permissions may be insufficient.
+ If the object exists and is not a file the error EISDIR is returned
+ under Unix.
+
+ .. Note::
+
+ The packing of parameters is very inefficient and appears to
+ indicate confusion between the system call creat and the VFS operation
+ create. The VFS operation create is only called to create new objects.
+ This create call differs from the Unix one in that it is not invoked
+ to return a file descriptor. The truncate and exclusive options,
+ together with the mode, could simply be part of the mode as it is
+ under Unix. There should be no flags argument; this is used in open
+ (2) to return a file descriptor for READ or WRITE mode.
+
+ The attributes of the directory should be returned too, since the size
+ and mtime changed.
+
+
+4.9. mkdir
+-----------
+
+
+ Summary
+ Create a new directory.
+
+ Arguments
+ in::
+
+ struct cfs_mkdir_in {
+ ViceFid VFid;
+ struct coda_vattr attr;
+ char *name; /* Place holder for data. */
+ } cfs_mkdir;
+
+
+
+ out::
+
+ struct cfs_mkdir_out {
+ ViceFid VFid;
+ struct coda_vattr attr;
+ } cfs_mkdir;
+
+
+
+
+ Description
+ This call is similar to create but creates a directory.
+ Only the mode field in the input parameters is used for creation.
+ Upon successful creation, the attr returned contains the attributes of
+ the new directory.
+
+ Errors
+ As for create.
+
+ .. Note::
+
+ The input parameter should be changed to mode instead of
+ attributes.
+
+ The attributes of the parent should be returned since the size and
+ mtime changes.
+
+
+4.10. link
+-----------
+
+
+ Summary
+ Create a link to an existing file.
+
+ Arguments
+ in::
+
+ struct cfs_link_in {
+ ViceFid sourceFid; /* cnode to link *to* */
+ ViceFid destFid; /* Directory in which to place link */
+ char *tname; /* Place holder for data. */
+ } cfs_link;
+
+
+
+ out
+
+ empty
+
+ Description
+ This call creates a link to the sourceFid in the directory
+ identified by destFid with name tname. The source must reside in the
+ target's parent, i.e. the source must be have parent destFid, i.e. Coda
+ does not support cross directory hard links. Only the return value is
+ relevant. It indicates success or the type of failure.
+
+ Errors
+ The usual errors can occur.
+
+
+4.11. symlink
+--------------
+
+
+ Summary
+ create a symbolic link
+
+ Arguments
+ in::
+
+ struct cfs_symlink_in {
+ ViceFid VFid; /* Directory to put symlink in */
+ char *srcname;
+ struct coda_vattr attr;
+ char *tname;
+ } cfs_symlink;
+
+
+
+ out
+
+ none
+
+ Description
+ Create a symbolic link. The link is to be placed in the
+ directory identified by VFid and named tname. It should point to the
+ pathname srcname. The attributes of the newly created object are to
+ be set to attr.
+
+ .. Note::
+
+ The attributes of the target directory should be returned since
+ its size changed.
+
+
+4.12. remove
+-------------
+
+
+ Summary
+ Remove a file
+
+ Arguments
+ in::
+
+ struct cfs_remove_in {
+ ViceFid VFid;
+ char *name; /* Place holder for data. */
+ } cfs_remove;
+
+
+
+ out
+
+ none
+
+ Description
+ Remove file named cfs_remove_in.name in directory
+ identified by VFid.
+
+
+ .. Note::
+
+ The attributes of the directory should be returned since its
+ mtime and size may change.
+
+
+4.13. rmdir
+------------
+
+
+ Summary
+ Remove a directory
+
+ Arguments
+ in::
+
+ struct cfs_rmdir_in {
+ ViceFid VFid;
+ char *name; /* Place holder for data. */
+ } cfs_rmdir;
+
+
+
+ out
+
+ none
+
+ Description
+ Remove the directory with name name from the directory
+ identified by VFid.
+
+ .. Note:: The attributes of the parent directory should be returned since
+ its mtime and size may change.
+
+
+4.14. readlink
+---------------
+
+
+ Summary
+ Read the value of a symbolic link.
+
+ Arguments
+ in::
+
+ struct cfs_readlink_in {
+ ViceFid VFid;
+ } cfs_readlink;
+
+
+
+ out::
+
+ struct cfs_readlink_out {
+ int count;
+ caddr_t data; /* Place holder for data. */
+ } cfs_readlink;
+
+
+
+ Description
+ This routine reads the contents of symbolic link
+ identified by VFid into the buffer data. The buffer data must be able
+ to hold any name up to CFS_MAXNAMLEN (PATH or NAM??).
+
+ Errors
+ No unusual errors.
+
+
+4.15. open
+-----------
+
+
+ Summary
+ Open a file.
+
+ Arguments
+ in::
+
+ struct cfs_open_in {
+ ViceFid VFid;
+ int flags;
+ } cfs_open;
+
+
+
+ out::
+
+ struct cfs_open_out {
+ dev_t dev;
+ ino_t inode;
+ } cfs_open;
+
+
+
+ Description
+ This request asks Venus to place the file identified by
+ VFid in its cache and to note that the calling process wishes to open
+ it with flags as in open(2). The return value to the kernel differs
+ for Unix and Windows systems. For Unix systems the Coda FS Driver is
+ informed of the device and inode number of the container file in the
+ fields dev and inode. For Windows the path of the container file is
+ returned to the kernel.
+
+
+ .. Note::
+
+ Currently the cfs_open_out structure is not properly adapted to
+ deal with the Windows case. It might be best to implement two
+ upcalls, one to open aiming at a container file name, the other at a
+ container file inode.
+
+
+4.16. close
+------------
+
+
+ Summary
+ Close a file, update it on the servers.
+
+ Arguments
+ in::
+
+ struct cfs_close_in {
+ ViceFid VFid;
+ int flags;
+ } cfs_close;
+
+
+
+ out
+
+ none
+
+ Description
+ Close the file identified by VFid.
+
+ .. Note::
+
+ The flags argument is bogus and not used. However, Venus' code
+ has room to deal with an execp input field, probably this field should
+ be used to inform Venus that the file was closed but is still memory
+ mapped for execution. There are comments about fetching versus not
+ fetching the data in Venus vproc_vfscalls. This seems silly. If a
+ file is being closed, the data in the container file is to be the new
+ data. Here again the execp flag might be in play to create confusion:
+ currently Venus might think a file can be flushed from the cache when
+ it is still memory mapped. This needs to be understood.
+
+
+4.17. ioctl
+------------
+
+
+ Summary
+ Do an ioctl on a file. This includes the pioctl interface.
+
+ Arguments
+ in::
+
+ struct cfs_ioctl_in {
+ ViceFid VFid;
+ int cmd;
+ int len;
+ int rwflag;
+ char *data; /* Place holder for data. */
+ } cfs_ioctl;
+
+
+
+ out::
+
+
+ struct cfs_ioctl_out {
+ int len;
+ caddr_t data; /* Place holder for data. */
+ } cfs_ioctl;
+
+
+
+ Description
+ Do an ioctl operation on a file. The command, len and
+ data arguments are filled as usual. flags is not used by Venus.
+
+ .. Note::
+
+ Another bogus parameter. flags is not used. What is the
+ business about PREFETCHING in the Venus code?
+
+
+
+4.18. rename
+-------------
+
+
+ Summary
+ Rename a fid.
+
+ Arguments
+ in::
+
+ struct cfs_rename_in {
+ ViceFid sourceFid;
+ char *srcname;
+ ViceFid destFid;
+ char *destname;
+ } cfs_rename;
+
+
+
+ out
+
+ none
+
+ Description
+ Rename the object with name srcname in directory
+ sourceFid to destname in destFid. It is important that the names
+ srcname and destname are 0 terminated strings. Strings in Unix
+ kernels are not always null terminated.
+
+
+4.19. readdir
+--------------
+
+
+ Summary
+ Read directory entries.
+
+ Arguments
+ in::
+
+ struct cfs_readdir_in {
+ ViceFid VFid;
+ int count;
+ int offset;
+ } cfs_readdir;
+
+
+
+
+ out::
+
+ struct cfs_readdir_out {
+ int size;
+ caddr_t data; /* Place holder for data. */
+ } cfs_readdir;
+
+
+
+ Description
+ Read directory entries from VFid starting at offset and
+ read at most count bytes. Returns the data in data and returns
+ the size in size.
+
+
+ .. Note::
+
+ This call is not used. Readdir operations exploit container
+ files. We will re-evaluate this during the directory revamp which is
+ about to take place.
+
+
+4.20. vget
+-----------
+
+
+ Summary
+ instructs Venus to do an FSDB->Get.
+
+ Arguments
+ in::
+
+ struct cfs_vget_in {
+ ViceFid VFid;
+ } cfs_vget;
+
+
+
+ out::
+
+ struct cfs_vget_out {
+ ViceFid VFid;
+ int vtype;
+ } cfs_vget;
+
+
+
+ Description
+ This upcall asks Venus to do a get operation on an fsobj
+ labelled by VFid.
+
+ .. Note::
+
+ This operation is not used. However, it is extremely useful
+ since it can be used to deal with read/write memory mapped files.
+ These can be "pinned" in the Venus cache using vget and released with
+ inactive.
+
+
+4.21. fsync
+------------
+
+
+ Summary
+ Tell Venus to update the RVM attributes of a file.
+
+ Arguments
+ in::
+
+ struct cfs_fsync_in {
+ ViceFid VFid;
+ } cfs_fsync;
+
+
+
+ out
+
+ none
+
+ Description
+ Ask Venus to update RVM attributes of object VFid. This
+ should be called as part of kernel level fsync type calls. The
+ result indicates if the syncing was successful.
+
+ .. Note:: Linux does not implement this call. It should.
+
+
+4.22. inactive
+---------------
+
+
+ Summary
+ Tell Venus a vnode is no longer in use.
+
+ Arguments
+ in::
+
+ struct cfs_inactive_in {
+ ViceFid VFid;
+ } cfs_inactive;
+
+
+
+ out
+
+ none
+
+ Description
+ This operation returns EOPNOTSUPP.
+
+ .. Note:: This should perhaps be removed.
+
+
+4.23. rdwr
+-----------
+
+
+ Summary
+ Read or write from a file
+
+ Arguments
+ in::
+
+ struct cfs_rdwr_in {
+ ViceFid VFid;
+ int rwflag;
+ int count;
+ int offset;
+ int ioflag;
+ caddr_t data; /* Place holder for data. */
+ } cfs_rdwr;
+
+
+
+
+ out::
+
+ struct cfs_rdwr_out {
+ int rwflag;
+ int count;
+ caddr_t data; /* Place holder for data. */
+ } cfs_rdwr;
+
+
+
+ Description
+ This upcall asks Venus to read or write from a file.
+
+
+ .. Note::
+
+ It should be removed since it is against the Coda philosophy that
+ read/write operations never reach Venus. I have been told the
+ operation does not work. It is not currently used.
+
+
+
+4.24. odymount
+---------------
+
+
+ Summary
+ Allows mounting multiple Coda "filesystems" on one Unix mount point.
+
+ Arguments
+ in::
+
+ struct ody_mount_in {
+ char *name; /* Place holder for data. */
+ } ody_mount;
+
+
+
+ out::
+
+ struct ody_mount_out {
+ ViceFid VFid;
+ } ody_mount;
+
+
+
+ Description
+ Asks Venus to return the rootfid of a Coda system named
+ name. The fid is returned in VFid.
+
+ .. Note::
+
+ This call was used by David for dynamic sets. It should be
+ removed since it causes a jungle of pointers in the VFS mounting area.
+ It is not used by Coda proper. Call is not implemented by Venus.
+
+
+4.25. ody_lookup
+-----------------
+
+
+ Summary
+ Looks up something.
+
+ Arguments
+ in
+
+ irrelevant
+
+
+ out
+
+ irrelevant
+
+
+ .. Note:: Gut it. Call is not implemented by Venus.
+
+
+4.26. ody_expand
+-----------------
+
+
+ Summary
+ expands something in a dynamic set.
+
+ Arguments
+ in
+
+ irrelevant
+
+ out
+
+ irrelevant
+
+ .. Note:: Gut it. Call is not implemented by Venus.
+
+
+4.27. prefetch
+---------------
+
+
+ Summary
+ Prefetch a dynamic set.
+
+ Arguments
+
+ in
+
+ Not documented.
+
+ out
+
+ Not documented.
+
+ Description
+ Venus worker.cc has support for this call, although it is
+ noted that it doesn't work. Not surprising, since the kernel does not
+ have support for it. (ODY_PREFETCH is not a defined operation).
+
+
+ .. Note:: Gut it. It isn't working and isn't used by Coda.
+
+
+
+4.28. signal
+-------------
+
+
+ Summary
+ Send Venus a signal about an upcall.
+
+ Arguments
+ in
+
+ none
+
+ out
+
+ not applicable.
+
+ Description
+ This is an out-of-band upcall to Venus to inform Venus
+ that the calling process received a signal after Venus read the
+ message from the input queue. Venus is supposed to clean up the
+ operation.
+
+ Errors
+ No reply is given.
+
+ .. Note::
+
+ We need to better understand what Venus needs to clean up and if
+ it is doing this correctly. Also we need to handle multiple upcall
+ per system call situations correctly. It would be important to know
+ what state changes in Venus take place after an upcall for which the
+ kernel is responsible for notifying Venus to clean up (e.g. open
+ definitely is such a state change, but many others are maybe not).
+
+
+5. The minicache and downcalls
+===============================
+
+
+ The Coda FS Driver can cache results of lookup and access upcalls, to
+ limit the frequency of upcalls. Upcalls carry a price since a process
+ context switch needs to take place. The counterpart of caching the
+ information is that Venus will notify the FS Driver that cached
+ entries must be flushed or renamed.
+
+ The kernel code generally has to maintain a structure which links the
+ internal file handles (called vnodes in BSD, inodes in Linux and
+ FileHandles in Windows) with the ViceFid's which Venus maintains. The
+ reason is that frequent translations back and forth are needed in
+ order to make upcalls and use the results of upcalls. Such linking
+ objects are called cnodes.
+
+ The current minicache implementations have cache entries which record
+ the following:
+
+ 1. the name of the file
+
+ 2. the cnode of the directory containing the object
+
+ 3. a list of CodaCred's for which the lookup is permitted.
+
+ 4. the cnode of the object
+
+ The lookup call in the Coda FS Driver may request the cnode of the
+ desired object from the cache, by passing its name, directory and the
+ CodaCred's of the caller. The cache will return the cnode or indicate
+ that it cannot be found. The Coda FS Driver must be careful to
+ invalidate cache entries when it modifies or removes objects.
+
+ When Venus obtains information that indicates that cache entries are
+ no longer valid, it will make a downcall to the kernel. Downcalls are
+ intercepted by the Coda FS Driver and lead to cache invalidations of
+ the kind described below. The Coda FS Driver does not return an error
+ unless the downcall data could not be read into kernel memory.
+
+
+5.1. INVALIDATE
+----------------
+
+
+ No information is available on this call.
+
+
+5.2. FLUSH
+-----------
+
+
+
+ Arguments
+ None
+
+ Summary
+ Flush the name cache entirely.
+
+ Description
+ Venus issues this call upon startup and when it dies. This
+ is to prevent stale cache information being held. Some operating
+ systems allow the kernel name cache to be switched off dynamically.
+ When this is done, this downcall is made.
+
+
+5.3. PURGEUSER
+---------------
+
+
+ Arguments
+ ::
+
+ struct cfs_purgeuser_out {/* CFS_PURGEUSER is a venus->kernel call */
+ struct CodaCred cred;
+ } cfs_purgeuser;
+
+
+
+ Description
+ Remove all entries in the cache carrying the Cred. This
+ call is issued when tokens for a user expire or are flushed.
+
+
+5.4. ZAPFILE
+-------------
+
+
+ Arguments
+ ::
+
+ struct cfs_zapfile_out { /* CFS_ZAPFILE is a venus->kernel call */
+ ViceFid CodaFid;
+ } cfs_zapfile;
+
+
+
+ Description
+ Remove all entries which have the (dir vnode, name) pair.
+ This is issued as a result of an invalidation of cached attributes of
+ a vnode.
+
+ .. Note::
+
+ Call is not named correctly in NetBSD and Mach. The minicache
+ zapfile routine takes different arguments. Linux does not implement
+ the invalidation of attributes correctly.
+
+
+
+5.5. ZAPDIR
+------------
+
+
+ Arguments
+ ::
+
+ struct cfs_zapdir_out { /* CFS_ZAPDIR is a venus->kernel call */
+ ViceFid CodaFid;
+ } cfs_zapdir;
+
+
+
+ Description
+ Remove all entries in the cache lying in a directory
+ CodaFid, and all children of this directory. This call is issued when
+ Venus receives a callback on the directory.
+
+
+5.6. ZAPVNODE
+--------------
+
+
+
+ Arguments
+ ::
+
+ struct cfs_zapvnode_out { /* CFS_ZAPVNODE is a venus->kernel call */
+ struct CodaCred cred;
+ ViceFid VFid;
+ } cfs_zapvnode;
+
+
+
+ Description
+ Remove all entries in the cache carrying the cred and VFid
+ as in the arguments. This downcall is probably never issued.
+
+
+5.7. PURGEFID
+--------------
+
+
+ Arguments
+ ::
+
+ struct cfs_purgefid_out { /* CFS_PURGEFID is a venus->kernel call */
+ ViceFid CodaFid;
+ } cfs_purgefid;
+
+
+
+ Description
+ Flush the attribute for the file. If it is a dir (odd
+ vnode), purge its children from the namecache and remove the file from the
+ namecache.
+
+
+
+5.8. REPLACE
+-------------
+
+
+ Summary
+ Replace the Fid's for a collection of names.
+
+ Arguments
+ ::
+
+ struct cfs_replace_out { /* cfs_replace is a venus->kernel call */
+ ViceFid NewFid;
+ ViceFid OldFid;
+ } cfs_replace;
+
+
+
+ Description
+ This routine replaces a ViceFid in the name cache with
+ another. It is added to allow Venus during reintegration to replace
+ locally allocated temp fids while disconnected with global fids even
+ when the reference counts on those fids are not zero.
+
+
+6. Initialization and cleanup
+==============================
+
+
+ This section gives brief hints as to desirable features for the Coda
+ FS Driver at startup and upon shutdown or Venus failures. Before
+ entering the discussion it is useful to repeat that the Coda FS Driver
+ maintains the following data:
+
+
+ 1. message queues
+
+ 2. cnodes
+
+ 3. name cache entries
+
+ The name cache entries are entirely private to the driver, so they
+ can easily be manipulated. The message queues will generally have
+ clear points of initialization and destruction. The cnodes are
+ much more delicate. User processes hold reference counts in Coda
+ filesystems and it can be difficult to clean up the cnodes.
+
+ It can expect requests through:
+
+ 1. the message subsystem
+
+ 2. the VFS layer
+
+ 3. pioctl interface
+
+ Currently the pioctl passes through the VFS for Coda so we can
+ treat these similarly.
+
+
+6.1. Requirements
+------------------
+
+
+ The following requirements should be accommodated:
+
+ 1. The message queues should have open and close routines. On Unix
+ the opening of the character devices are such routines.
+
+ - Before opening, no messages can be placed.
+
+ - Opening will remove any old messages still pending.
+
+ - Close will notify any sleeping processes that their upcall cannot
+ be completed.
+
+ - Close will free all memory allocated by the message queues.
+
+
+ 2. At open the namecache shall be initialized to empty state.
+
+ 3. Before the message queues are open, all VFS operations will fail.
+ Fortunately this can be achieved by making sure than mounting the
+ Coda filesystem cannot succeed before opening.
+
+ 4. After closing of the queues, no VFS operations can succeed. Here
+ one needs to be careful, since a few operations (lookup,
+ read/write, readdir) can proceed without upcalls. These must be
+ explicitly blocked.
+
+ 5. Upon closing the namecache shall be flushed and disabled.
+
+ 6. All memory held by cnodes can be freed without relying on upcalls.
+
+ 7. Unmounting the file system can be done without relying on upcalls.
+
+ 8. Mounting the Coda filesystem should fail gracefully if Venus cannot
+ get the rootfid or the attributes of the rootfid. The latter is
+ best implemented by Venus fetching these objects before attempting
+ to mount.
+
+ .. Note::
+
+ NetBSD in particular but also Linux have not implemented the
+ above requirements fully. For smooth operation this needs to be
+ corrected.
+
+
+
diff --git a/Documentation/filesystems/coda.txt b/Documentation/filesystems/coda.txt
deleted file mode 100644
index 1711ad4..0000000
--- a/Documentation/filesystems/coda.txt
+++ /dev/null
@@ -1,1676 +0,0 @@
-NOTE:
-This is one of the technical documents describing a component of
-Coda -- this document describes the client kernel-Venus interface.
-
-For more information:
- http://www.coda.cs.cmu.edu
-For user level software needed to run Coda:
- ftp://ftp.coda.cs.cmu.edu
-
-To run Coda you need to get a user level cache manager for the client,
-named Venus, as well as tools to manipulate ACLs, to log in, etc. The
-client needs to have the Coda filesystem selected in the kernel
-configuration.
-
-The server needs a user level server and at present does not depend on
-kernel support.
-
-
-
-
-
-
-
- The Venus kernel interface
- Peter J. Braam
- v1.0, Nov 9, 1997
-
- This document describes the communication between Venus and kernel
- level filesystem code needed for the operation of the Coda file sys-
- tem. This document version is meant to describe the current interface
- (version 1.0) as well as improvements we envisage.
- ______________________________________________________________________
-
- Table of Contents
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- 1. Introduction
-
- 2. Servicing Coda filesystem calls
-
- 3. The message layer
-
- 3.1 Implementation details
-
- 4. The interface at the call level
-
- 4.1 Data structures shared by the kernel and Venus
- 4.2 The pioctl interface
- 4.3 root
- 4.4 lookup
- 4.5 getattr
- 4.6 setattr
- 4.7 access
- 4.8 create
- 4.9 mkdir
- 4.10 link
- 4.11 symlink
- 4.12 remove
- 4.13 rmdir
- 4.14 readlink
- 4.15 open
- 4.16 close
- 4.17 ioctl
- 4.18 rename
- 4.19 readdir
- 4.20 vget
- 4.21 fsync
- 4.22 inactive
- 4.23 rdwr
- 4.24 odymount
- 4.25 ody_lookup
- 4.26 ody_expand
- 4.27 prefetch
- 4.28 signal
-
- 5. The minicache and downcalls
-
- 5.1 INVALIDATE
- 5.2 FLUSH
- 5.3 PURGEUSER
- 5.4 ZAPFILE
- 5.5 ZAPDIR
- 5.6 ZAPVNODE
- 5.7 PURGEFID
- 5.8 REPLACE
-
- 6. Initialization and cleanup
-
- 6.1 Requirements
-
-
- ______________________________________________________________________
- 0wpage
-
- 11.. IInnttrroodduuccttiioonn
-
-
-
- A key component in the Coda Distributed File System is the cache
- manager, _V_e_n_u_s.
-
-
- When processes on a Coda enabled system access files in the Coda
- filesystem, requests are directed at the filesystem layer in the
- operating system. The operating system will communicate with Venus to
- service the request for the process. Venus manages a persistent
- client cache and makes remote procedure calls to Coda file servers and
- related servers (such as authentication servers) to service these
- requests it receives from the operating system. When Venus has
- serviced a request it replies to the operating system with appropriate
- return codes, and other data related to the request. Optionally the
- kernel support for Coda may maintain a minicache of recently processed
- requests to limit the number of interactions with Venus. Venus
- possesses the facility to inform the kernel when elements from its
- minicache are no longer valid.
-
- This document describes precisely this communication between the
- kernel and Venus. The definitions of so called upcalls and downcalls
- will be given with the format of the data they handle. We shall also
- describe the semantic invariants resulting from the calls.
-
- Historically Coda was implemented in a BSD file system in Mach 2.6.
- The interface between the kernel and Venus is very similar to the BSD
- VFS interface. Similar functionality is provided, and the format of
- the parameters and returned data is very similar to the BSD VFS. This
- leads to an almost natural environment for implementing a kernel-level
- filesystem driver for Coda in a BSD system. However, other operating
- systems such as Linux and Windows 95 and NT have virtual filesystem
- with different interfaces.
-
- To implement Coda on these systems some reverse engineering of the
- Venus/Kernel protocol is necessary. Also it came to light that other
- systems could profit significantly from certain small optimizations
- and modifications to the protocol. To facilitate this work as well as
- to make future ports easier, communication between Venus and the
- kernel should be documented in great detail. This is the aim of this
- document.
-
- 0wpage
-
- 22.. SSeerrvviicciinngg CCooddaa ffiilleessyysstteemm ccaallllss
-
- The service of a request for a Coda file system service originates in
- a process PP which accessing a Coda file. It makes a system call which
- traps to the OS kernel. Examples of such calls trapping to the kernel
- are _r_e_a_d_, _w_r_i_t_e_, _o_p_e_n_, _c_l_o_s_e_, _c_r_e_a_t_e_, _m_k_d_i_r_, _r_m_d_i_r_, _c_h_m_o_d in a Unix
- context. Similar calls exist in the Win32 environment, and are named
- _C_r_e_a_t_e_F_i_l_e_, .
-
- Generally the operating system handles the request in a virtual
- filesystem (VFS) layer, which is named I/O Manager in NT and IFS
- manager in Windows 95. The VFS is responsible for partial processing
- of the request and for locating the specific filesystem(s) which will
- service parts of the request. Usually the information in the path
- assists in locating the correct FS drivers. Sometimes after extensive
- pre-processing, the VFS starts invoking exported routines in the FS
- driver. This is the point where the FS specific processing of the
- request starts, and here the Coda specific kernel code comes into
- play.
-
- The FS layer for Coda must expose and implement several interfaces.
- First and foremost the VFS must be able to make all necessary calls to
- the Coda FS layer, so the Coda FS driver must expose the VFS interface
- as applicable in the operating system. These differ very significantly
- among operating systems, but share features such as facilities to
- read/write and create and remove objects. The Coda FS layer services
- such VFS requests by invoking one or more well defined services
- offered by the cache manager Venus. When the replies from Venus have
- come back to the FS driver, servicing of the VFS call continues and
- finishes with a reply to the kernel's VFS. Finally the VFS layer
- returns to the process.
-
- As a result of this design a basic interface exposed by the FS driver
- must allow Venus to manage message traffic. In particular Venus must
- be able to retrieve and place messages and to be notified of the
- arrival of a new message. The notification must be through a mechanism
- which does not block Venus since Venus must attend to other tasks even
- when no messages are waiting or being processed.
-
-
-
-
-
-
- Interfaces of the Coda FS Driver
-
- Furthermore the FS layer provides for a special path of communication
- between a user process and Venus, called the pioctl interface. The
- pioctl interface is used for Coda specific services, such as
- requesting detailed information about the persistent cache managed by
- Venus. Here the involvement of the kernel is minimal. It identifies
- the calling process and passes the information on to Venus. When
- Venus replies the response is passed back to the caller in unmodified
- form.
-
- Finally Venus allows the kernel FS driver to cache the results from
- certain services. This is done to avoid excessive context switches
- and results in an efficient system. However, Venus may acquire
- information, for example from the network which implies that cached
- information must be flushed or replaced. Venus then makes a downcall
- to the Coda FS layer to request flushes or updates in the cache. The
- kernel FS driver handles such requests synchronously.
-
- Among these interfaces the VFS interface and the facility to place,
- receive and be notified of messages are platform specific. We will
- not go into the calls exported to the VFS layer but we will state the
- requirements of the message exchange mechanism.
-
- 0wpage
-
- 33.. TThhee mmeessssaaggee llaayyeerr
-
-
-
- At the lowest level the communication between Venus and the FS driver
- proceeds through messages. The synchronization between processes
- requesting Coda file service and Venus relies on blocking and waking
- up processes. The Coda FS driver processes VFS- and pioctl-requests
- on behalf of a process P, creates messages for Venus, awaits replies
- and finally returns to the caller. The implementation of the exchange
- of messages is platform specific, but the semantics have (so far)
- appeared to be generally applicable. Data buffers are created by the
- FS Driver in kernel memory on behalf of P and copied to user memory in
- Venus.
-
- The FS Driver while servicing P makes upcalls to Venus. Such an
- upcall is dispatched to Venus by creating a message structure. The
- structure contains the identification of P, the message sequence
- number, the size of the request and a pointer to the data in kernel
- memory for the request. Since the data buffer is re-used to hold the
- reply from Venus, there is a field for the size of the reply. A flags
- field is used in the message to precisely record the status of the
- message. Additional platform dependent structures involve pointers to
- determine the position of the message on queues and pointers to
- synchronization objects. In the upcall routine the message structure
- is filled in, flags are set to 0, and it is placed on the _p_e_n_d_i_n_g
- queue. The routine calling upcall is responsible for allocating the
- data buffer; its structure will be described in the next section.
-
- A facility must exist to notify Venus that the message has been
- created, and implemented using available synchronization objects in
- the OS. This notification is done in the upcall context of the process
- P. When the message is on the pending queue, process P cannot proceed
- in upcall. The (kernel mode) processing of P in the filesystem
- request routine must be suspended until Venus has replied. Therefore
- the calling thread in P is blocked in upcall. A pointer in the
- message structure will locate the synchronization object on which P is
- sleeping.
-
- Venus detects the notification that a message has arrived, and the FS
- driver allow Venus to retrieve the message with a getmsg_from_kernel
- call. This action finishes in the kernel by putting the message on the
- queue of processing messages and setting flags to READ. Venus is
- passed the contents of the data buffer. The getmsg_from_kernel call
- now returns and Venus processes the request.
-
- At some later point the FS driver receives a message from Venus,
- namely when Venus calls sendmsg_to_kernel. At this moment the Coda FS
- driver looks at the contents of the message and decides if:
-
-
- +o the message is a reply for a suspended thread P. If so it removes
- the message from the processing queue and marks the message as
- WRITTEN. Finally, the FS driver unblocks P (still in the kernel
- mode context of Venus) and the sendmsg_to_kernel call returns to
- Venus. The process P will be scheduled at some point and continues
- processing its upcall with the data buffer replaced with the reply
- from Venus.
-
- +o The message is a _d_o_w_n_c_a_l_l. A downcall is a request from Venus to
- the FS Driver. The FS driver processes the request immediately
- (usually a cache eviction or replacement) and when it finishes
- sendmsg_to_kernel returns.
-
- Now P awakes and continues processing upcall. There are some
- subtleties to take account of. First P will determine if it was woken
- up in upcall by a signal from some other source (for example an
- attempt to terminate P) or as is normally the case by Venus in its
- sendmsg_to_kernel call. In the normal case, the upcall routine will
- deallocate the message structure and return. The FS routine can proceed
- with its processing.
-
-
-
-
-
-
-
- Sleeping and IPC arrangements
-
- In case P is woken up by a signal and not by Venus, it will first look
- at the flags field. If the message is not yet READ, the process P can
- handle its signal without notifying Venus. If Venus has READ, and
- the request should not be processed, P can send Venus a signal message
- to indicate that it should disregard the previous message. Such
- signals are put in the queue at the head, and read first by Venus. If
- the message is already marked as WRITTEN it is too late to stop the
- processing. The VFS routine will now continue. (-- If a VFS request
- involves more than one upcall, this can lead to complicated state, an
- extra field "handle_signals" could be added in the message structure
- to indicate points of no return have been passed.--)
-
-
-
- 33..11.. IImmpplleemmeennttaattiioonn ddeettaaiillss
-
- The Unix implementation of this mechanism has been through the
- implementation of a character device associated with Coda. Venus
- retrieves messages by doing a read on the device, replies are sent
- with a write and notification is through the select system call on the
- file descriptor for the device. The process P is kept waiting on an
- interruptible wait queue object.
-
- In Windows NT and the DPMI Windows 95 implementation a DeviceIoControl
- call is used. The DeviceIoControl call is designed to copy buffers
- from user memory to kernel memory with OPCODES. The sendmsg_to_kernel
- is issued as a synchronous call, while the getmsg_from_kernel call is
- asynchronous. Windows EventObjects are used for notification of
- message arrival. The process P is kept waiting on a KernelEvent
- object in NT and a semaphore in Windows 95.
-
- 0wpage
-
- 44.. TThhee iinntteerrffaaccee aatt tthhee ccaallll lleevveell
-
-
- This section describes the upcalls a Coda FS driver can make to Venus.
- Each of these upcalls make use of two structures: inputArgs and
- outputArgs. In pseudo BNF form the structures take the following
- form:
-
-
- struct inputArgs {
- u_long opcode;
- u_long unique; /* Keep multiple outstanding msgs distinct */
- u_short pid; /* Common to all */
- u_short pgid; /* Common to all */
- struct CodaCred cred; /* Common to all */
-
- <union "in" of call dependent parts of inputArgs>
- };
-
- struct outputArgs {
- u_long opcode;
- u_long unique; /* Keep multiple outstanding msgs distinct */
- u_long result;
-
- <union "out" of call dependent parts of inputArgs>
- };
-
-
-
- Before going on let us elucidate the role of the various fields. The
- inputArgs start with the opcode which defines the type of service
- requested from Venus. There are approximately 30 upcalls at present
- which we will discuss. The unique field labels the inputArg with a
- unique number which will identify the message uniquely. A process and
- process group id are passed. Finally the credentials of the caller
- are included.
-
- Before delving into the specific calls we need to discuss a variety of
- data structures shared by the kernel and Venus.
-
-
-
-
- 44..11.. DDaattaa ssttrruuccttuurreess sshhaarreedd bbyy tthhee kkeerrnneell aanndd VVeennuuss
-
-
- The CodaCred structure defines a variety of user and group ids as
- they are set for the calling process. The vuid_t and vgid_t are 32 bit
- unsigned integers. It also defines group membership in an array. On
- Unix the CodaCred has proven sufficient to implement good security
- semantics for Coda but the structure may have to undergo modification
- for the Windows environment when these mature.
-
- struct CodaCred {
- vuid_t cr_uid, cr_euid, cr_suid, cr_fsuid; /* Real, effective, set, fs uid */
- vgid_t cr_gid, cr_egid, cr_sgid, cr_fsgid; /* same for groups */
- vgid_t cr_groups[NGROUPS]; /* Group membership for caller */
- };
-
-
-
- NNOOTTEE It is questionable if we need CodaCreds in Venus. Finally Venus
- doesn't know about groups, although it does create files with the
- default uid/gid. Perhaps the list of group membership is superfluous.
-
-
- The next item is the fundamental identifier used to identify Coda
- files, the ViceFid. A fid of a file uniquely defines a file or
- directory in the Coda filesystem within a _c_e_l_l. (-- A _c_e_l_l is a
- group of Coda servers acting under the aegis of a single system
- control machine or SCM. See the Coda Administration manual for a
- detailed description of the role of the SCM.--)
-
-
- typedef struct ViceFid {
- VolumeId Volume;
- VnodeId Vnode;
- Unique_t Unique;
- } ViceFid;
-
-
-
- Each of the constituent fields: VolumeId, VnodeId and Unique_t are
- unsigned 32 bit integers. We envisage that a further field will need
- to be prefixed to identify the Coda cell; this will probably take the
- form of a Ipv6 size IP address naming the Coda cell through DNS.
-
- The next important structure shared between Venus and the kernel is
- the attributes of the file. The following structure is used to
- exchange information. It has room for future extensions such as
- support for device files (currently not present in Coda).
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
- struct coda_timespec {
- int64_t tv_sec; /* seconds */
- long tv_nsec; /* nanoseconds */
- };
-
- struct coda_vattr {
- enum coda_vtype va_type; /* vnode type (for create) */
- u_short va_mode; /* files access mode and type */
- short va_nlink; /* number of references to file */
- vuid_t va_uid; /* owner user id */
- vgid_t va_gid; /* owner group id */
- long va_fsid; /* file system id (dev for now) */
- long va_fileid; /* file id */
- u_quad_t va_size; /* file size in bytes */
- long va_blocksize; /* blocksize preferred for i/o */
- struct coda_timespec va_atime; /* time of last access */
- struct coda_timespec va_mtime; /* time of last modification */
- struct coda_timespec va_ctime; /* time file changed */
- u_long va_gen; /* generation number of file */
- u_long va_flags; /* flags defined for file */
- dev_t va_rdev; /* device special file represents */
- u_quad_t va_bytes; /* bytes of disk space held by file */
- u_quad_t va_filerev; /* file modification number */
- u_int va_vaflags; /* operations flags, see below */
- long va_spare; /* remain quad aligned */
- };
-
-
-
-
- 44..22.. TThhee ppiiooccttll iinntteerrffaaccee
-
-
- Coda specific requests can be made by application through the pioctl
- interface. The pioctl is implemented as an ordinary ioctl on a
- fictitious file /coda/.CONTROL. The pioctl call opens this file, gets
- a file handle and makes the ioctl call. Finally it closes the file.
-
- The kernel involvement in this is limited to providing the facility to
- open and close and pass the ioctl message _a_n_d to verify that a path in
- the pioctl data buffers is a file in a Coda filesystem.
-
- The kernel is handed a data packet of the form:
-
- struct {
- const char *path;
- struct ViceIoctl vidata;
- int follow;
- } data;
-
-
-
- where
-
-
- struct ViceIoctl {
- caddr_t in, out; /* Data to be transferred in, or out */
- short in_size; /* Size of input buffer <= 2K */
- short out_size; /* Maximum size of output buffer, <= 2K */
- };
-
-
-
- The path must be a Coda file, otherwise the ioctl upcall will not be
- made.
-
- NNOOTTEE The data structures and code are a mess. We need to clean this
- up.
-
- We now proceed to document the individual calls:
-
- 0wpage
-
- 44..33.. rroooott
-
-
- AArrgguummeennttss
-
- iinn empty
-
- oouutt
-
- struct cfs_root_out {
- ViceFid VFid;
- } cfs_root;
-
-
-
- DDeessccrriippttiioonn This call is made to Venus during the initialization of
- the Coda filesystem. If the result is zero, the cfs_root structure
- contains the ViceFid of the root of the Coda filesystem. If a non-zero
- result is generated, its value is a platform dependent error code
- indicating the difficulty Venus encountered in locating the root of
- the Coda filesystem.
-
- 0wpage
-
- 44..44.. llooookkuupp
-
-
- SSuummmmaarryy Find the ViceFid and type of an object in a directory if it
- exists.
-
- AArrgguummeennttss
-
- iinn
-
- struct cfs_lookup_in {
- ViceFid VFid;
- char *name; /* Place holder for data. */
- } cfs_lookup;
-
-
-
- oouutt
-
- struct cfs_lookup_out {
- ViceFid VFid;
- int vtype;
- } cfs_lookup;
-
-
-
- DDeessccrriippttiioonn This call is made to determine the ViceFid and filetype of
- a directory entry. The directory entry requested carries name name
- and Venus will search the directory identified by cfs_lookup_in.VFid.
- The result may indicate that the name does not exist, or that
- difficulty was encountered in finding it (e.g. due to disconnection).
- If the result is zero, the field cfs_lookup_out.VFid contains the
- targets ViceFid and cfs_lookup_out.vtype the coda_vtype giving the
- type of object the name designates.
-
- The name of the object is an 8 bit character string of maximum length
- CFS_MAXNAMLEN, currently set to 256 (including a 0 terminator.)
-
- It is extremely important to realize that Venus bitwise ors the field
- cfs_lookup.vtype with CFS_NOCACHE to indicate that the object should
- not be put in the kernel name cache.
-
- NNOOTTEE The type of the vtype is currently wrong. It should be
- coda_vtype. Linux does not take note of CFS_NOCACHE. It should.
-
- 0wpage
-
- 44..55.. ggeettaattttrr
-
-
- SSuummmmaarryy Get the attributes of a file.
-
- AArrgguummeennttss
-
- iinn
-
- struct cfs_getattr_in {
- ViceFid VFid;
- struct coda_vattr attr; /* XXXXX */
- } cfs_getattr;
-
-
-
- oouutt
-
- struct cfs_getattr_out {
- struct coda_vattr attr;
- } cfs_getattr;
-
-
-
- DDeessccrriippttiioonn This call returns the attributes of the file identified by
- fid.
-
- EErrrroorrss Errors can occur if the object with fid does not exist, is
- unaccessible or if the caller does not have permission to fetch
- attributes.
-
- NNoottee Many kernel FS drivers (Linux, NT and Windows 95) need to acquire
- the attributes as well as the Fid for the instantiation of an internal
- "inode" or "FileHandle". A significant improvement in performance on
- such systems could be made by combining the _l_o_o_k_u_p and _g_e_t_a_t_t_r calls
- both at the Venus/kernel interaction level and at the RPC level.
-
- The vattr structure included in the input arguments is superfluous and
- should be removed.
-
- 0wpage
-
- 44..66.. sseettaattttrr
-
-
- SSuummmmaarryy Set the attributes of a file.
-
- AArrgguummeennttss
-
- iinn
-
- struct cfs_setattr_in {
- ViceFid VFid;
- struct coda_vattr attr;
- } cfs_setattr;
-
-
-
-
- oouutt
- empty
-
- DDeessccrriippttiioonn The structure attr is filled with attributes to be changed
- in BSD style. Attributes not to be changed are set to -1, apart from
- vtype which is set to VNON. Other are set to the value to be assigned.
- The only attributes which the FS driver may request to change are the
- mode, owner, groupid, atime, mtime and ctime. The return value
- indicates success or failure.
-
- EErrrroorrss A variety of errors can occur. The object may not exist, may
- be inaccessible, or permission may not be granted by Venus.
-
- 0wpage
-
- 44..77.. aacccceessss
-
-
- SSuummmmaarryy
-
- AArrgguummeennttss
-
- iinn
-
- struct cfs_access_in {
- ViceFid VFid;
- int flags;
- } cfs_access;
-
-
-
- oouutt
- empty
-
- DDeessccrriippttiioonn Verify if access to the object identified by VFid for
- operations described by flags is permitted. The result indicates if
- access will be granted. It is important to remember that Coda uses
- ACLs to enforce protection and that ultimately the servers, not the
- clients enforce the security of the system. The result of this call
- will depend on whether a _t_o_k_e_n is held by the user.
-
- EErrrroorrss The object may not exist, or the ACL describing the protection
- may not be accessible.
-
- 0wpage
-
- 44..88.. ccrreeaattee
-
-
- SSuummmmaarryy Invoked to create a file
-
- AArrgguummeennttss
-
- iinn
-
- struct cfs_create_in {
- ViceFid VFid;
- struct coda_vattr attr;
- int excl;
- int mode;
- char *name; /* Place holder for data. */
- } cfs_create;
-
-
-
-
- oouutt
-
- struct cfs_create_out {
- ViceFid VFid;
- struct coda_vattr attr;
- } cfs_create;
-
-
-
- DDeessccrriippttiioonn This upcall is invoked to request creation of a file.
- The file will be created in the directory identified by VFid, its name
- will be name, and the mode will be mode. If excl is set an error will
- be returned if the file already exists. If the size field in attr is
- set to zero the file will be truncated. The uid and gid of the file
- are set by converting the CodaCred to a uid using a macro CRTOUID
- (this macro is platform dependent). Upon success the VFid and
- attributes of the file are returned. The Coda FS Driver will normally
- instantiate a vnode, inode or file handle at kernel level for the new
- object.
-
-
- EErrrroorrss A variety of errors can occur. Permissions may be insufficient.
- If the object exists and is not a file the error EISDIR is returned
- under Unix.
-
- NNOOTTEE The packing of parameters is very inefficient and appears to
- indicate confusion between the system call creat and the VFS operation
- create. The VFS operation create is only called to create new objects.
- This create call differs from the Unix one in that it is not invoked
- to return a file descriptor. The truncate and exclusive options,
- together with the mode, could simply be part of the mode as it is
- under Unix. There should be no flags argument; this is used in open
- (2) to return a file descriptor for READ or WRITE mode.
-
- The attributes of the directory should be returned too, since the size
- and mtime changed.
-
- 0wpage
-
- 44..99.. mmkkddiirr
-
-
- SSuummmmaarryy Create a new directory.
-
- AArrgguummeennttss
-
- iinn
-
- struct cfs_mkdir_in {
- ViceFid VFid;
- struct coda_vattr attr;
- char *name; /* Place holder for data. */
- } cfs_mkdir;
-
-
-
- oouutt
-
- struct cfs_mkdir_out {
- ViceFid VFid;
- struct coda_vattr attr;
- } cfs_mkdir;
-
-
-
-
- DDeessccrriippttiioonn This call is similar to create but creates a directory.
- Only the mode field in the input parameters is used for creation.
- Upon successful creation, the attr returned contains the attributes of
- the new directory.
-
- EErrrroorrss As for create.
-
- NNOOTTEE The input parameter should be changed to mode instead of
- attributes.
-
- The attributes of the parent should be returned since the size and
- mtime changes.
-
- 0wpage
-
- 44..1100.. lliinnkk
-
-
- SSuummmmaarryy Create a link to an existing file.
-
- AArrgguummeennttss
-
- iinn
-
- struct cfs_link_in {
- ViceFid sourceFid; /* cnode to link *to* */
- ViceFid destFid; /* Directory in which to place link */
- char *tname; /* Place holder for data. */
- } cfs_link;
-
-
-
- oouutt
- empty
-
- DDeessccrriippttiioonn This call creates a link to the sourceFid in the directory
- identified by destFid with name tname. The source must reside in the
- target's parent, i.e. the source must be have parent destFid, i.e. Coda
- does not support cross directory hard links. Only the return value is
- relevant. It indicates success or the type of failure.
-
- EErrrroorrss The usual errors can occur.0wpage
-
- 44..1111.. ssyymmlliinnkk
-
-
- SSuummmmaarryy create a symbolic link
-
- AArrgguummeennttss
-
- iinn
-
- struct cfs_symlink_in {
- ViceFid VFid; /* Directory to put symlink in */
- char *srcname;
- struct coda_vattr attr;
- char *tname;
- } cfs_symlink;
-
-
-
- oouutt
- none
-
- DDeessccrriippttiioonn Create a symbolic link. The link is to be placed in the
- directory identified by VFid and named tname. It should point to the
- pathname srcname. The attributes of the newly created object are to
- be set to attr.
-
- EErrrroorrss
-
- NNOOTTEE The attributes of the target directory should be returned since
- its size changed.
-
- 0wpage
-
- 44..1122.. rreemmoovvee
-
-
- SSuummmmaarryy Remove a file
-
- AArrgguummeennttss
-
- iinn
-
- struct cfs_remove_in {
- ViceFid VFid;
- char *name; /* Place holder for data. */
- } cfs_remove;
-
-
-
- oouutt
- none
-
- DDeessccrriippttiioonn Remove file named cfs_remove_in.name in directory
- identified by VFid.
-
- EErrrroorrss
-
- NNOOTTEE The attributes of the directory should be returned since its
- mtime and size may change.
-
- 0wpage
-
- 44..1133.. rrmmddiirr
-
-
- SSuummmmaarryy Remove a directory
-
- AArrgguummeennttss
-
- iinn
-
- struct cfs_rmdir_in {
- ViceFid VFid;
- char *name; /* Place holder for data. */
- } cfs_rmdir;
-
-
-
- oouutt
- none
-
- DDeessccrriippttiioonn Remove the directory with name name from the directory
- identified by VFid.
-
- EErrrroorrss
-
- NNOOTTEE The attributes of the parent directory should be returned since
- its mtime and size may change.
-
- 0wpage
-
- 44..1144.. rreeaaddlliinnkk
-
-
- SSuummmmaarryy Read the value of a symbolic link.
-
- AArrgguummeennttss
-
- iinn
-
- struct cfs_readlink_in {
- ViceFid VFid;
- } cfs_readlink;
-
-
-
- oouutt
-
- struct cfs_readlink_out {
- int count;
- caddr_t data; /* Place holder for data. */
- } cfs_readlink;
-
-
-
- DDeessccrriippttiioonn This routine reads the contents of symbolic link
- identified by VFid into the buffer data. The buffer data must be able
- to hold any name up to CFS_MAXNAMLEN (PATH or NAM??).
-
- EErrrroorrss No unusual errors.
-
- 0wpage
-
- 44..1155.. ooppeenn
-
-
- SSuummmmaarryy Open a file.
-
- AArrgguummeennttss
-
- iinn
-
- struct cfs_open_in {
- ViceFid VFid;
- int flags;
- } cfs_open;
-
-
-
- oouutt
-
- struct cfs_open_out {
- dev_t dev;
- ino_t inode;
- } cfs_open;
-
-
-
- DDeessccrriippttiioonn This request asks Venus to place the file identified by
- VFid in its cache and to note that the calling process wishes to open
- it with flags as in open(2). The return value to the kernel differs
- for Unix and Windows systems. For Unix systems the Coda FS Driver is
- informed of the device and inode number of the container file in the
- fields dev and inode. For Windows the path of the container file is
- returned to the kernel.
- EErrrroorrss
-
- NNOOTTEE Currently the cfs_open_out structure is not properly adapted to
- deal with the Windows case. It might be best to implement two
- upcalls, one to open aiming at a container file name, the other at a
- container file inode.
-
- 0wpage
-
- 44..1166.. cclloossee
-
-
- SSuummmmaarryy Close a file, update it on the servers.
-
- AArrgguummeennttss
-
- iinn
-
- struct cfs_close_in {
- ViceFid VFid;
- int flags;
- } cfs_close;
-
-
-
- oouutt
- none
-
- DDeessccrriippttiioonn Close the file identified by VFid.
-
- EErrrroorrss
-
- NNOOTTEE The flags argument is bogus and not used. However, Venus' code
- has room to deal with an execp input field, probably this field should
- be used to inform Venus that the file was closed but is still memory
- mapped for execution. There are comments about fetching versus not
- fetching the data in Venus vproc_vfscalls. This seems silly. If a
- file is being closed, the data in the container file is to be the new
- data. Here again the execp flag might be in play to create confusion:
- currently Venus might think a file can be flushed from the cache when
- it is still memory mapped. This needs to be understood.
-
- 0wpage
-
- 44..1177.. iiooccttll
-
-
- SSuummmmaarryy Do an ioctl on a file. This includes the pioctl interface.
-
- AArrgguummeennttss
-
- iinn
-
- struct cfs_ioctl_in {
- ViceFid VFid;
- int cmd;
- int len;
- int rwflag;
- char *data; /* Place holder for data. */
- } cfs_ioctl;
-
-
-
- oouutt
-
-
- struct cfs_ioctl_out {
- int len;
- caddr_t data; /* Place holder for data. */
- } cfs_ioctl;
-
-
-
- DDeessccrriippttiioonn Do an ioctl operation on a file. The command, len and
- data arguments are filled as usual. flags is not used by Venus.
-
- EErrrroorrss
-
- NNOOTTEE Another bogus parameter. flags is not used. What is the
- business about PREFETCHING in the Venus code?
-
-
- 0wpage
-
- 44..1188.. rreennaammee
-
-
- SSuummmmaarryy Rename a fid.
-
- AArrgguummeennttss
-
- iinn
-
- struct cfs_rename_in {
- ViceFid sourceFid;
- char *srcname;
- ViceFid destFid;
- char *destname;
- } cfs_rename;
-
-
-
- oouutt
- none
-
- DDeessccrriippttiioonn Rename the object with name srcname in directory
- sourceFid to destname in destFid. It is important that the names
- srcname and destname are 0 terminated strings. Strings in Unix
- kernels are not always null terminated.
-
- EErrrroorrss
-
- 0wpage
-
- 44..1199.. rreeaaddddiirr
-
-
- SSuummmmaarryy Read directory entries.
-
- AArrgguummeennttss
-
- iinn
-
- struct cfs_readdir_in {
- ViceFid VFid;
- int count;
- int offset;
- } cfs_readdir;
-
-
-
-
- oouutt
-
- struct cfs_readdir_out {
- int size;
- caddr_t data; /* Place holder for data. */
- } cfs_readdir;
-
-
-
- DDeessccrriippttiioonn Read directory entries from VFid starting at offset and
- read at most count bytes. Returns the data in data and returns
- the size in size.
-
- EErrrroorrss
-
- NNOOTTEE This call is not used. Readdir operations exploit container
- files. We will re-evaluate this during the directory revamp which is
- about to take place.
-
- 0wpage
-
- 44..2200.. vvggeett
-
-
- SSuummmmaarryy instructs Venus to do an FSDB->Get.
-
- AArrgguummeennttss
-
- iinn
-
- struct cfs_vget_in {
- ViceFid VFid;
- } cfs_vget;
-
-
-
- oouutt
-
- struct cfs_vget_out {
- ViceFid VFid;
- int vtype;
- } cfs_vget;
-
-
-
- DDeessccrriippttiioonn This upcall asks Venus to do a get operation on an fsobj
- labelled by VFid.
-
- EErrrroorrss
-
- NNOOTTEE This operation is not used. However, it is extremely useful
- since it can be used to deal with read/write memory mapped files.
- These can be "pinned" in the Venus cache using vget and released with
- inactive.
-
- 0wpage
-
- 44..2211.. ffssyynncc
-
-
- SSuummmmaarryy Tell Venus to update the RVM attributes of a file.
-
- AArrgguummeennttss
-
- iinn
-
- struct cfs_fsync_in {
- ViceFid VFid;
- } cfs_fsync;
-
-
-
- oouutt
- none
-
- DDeessccrriippttiioonn Ask Venus to update RVM attributes of object VFid. This
- should be called as part of kernel level fsync type calls. The
- result indicates if the syncing was successful.
-
- EErrrroorrss
-
- NNOOTTEE Linux does not implement this call. It should.
-
- 0wpage
-
- 44..2222.. iinnaaccttiivvee
-
-
- SSuummmmaarryy Tell Venus a vnode is no longer in use.
-
- AArrgguummeennttss
-
- iinn
-
- struct cfs_inactive_in {
- ViceFid VFid;
- } cfs_inactive;
-
-
-
- oouutt
- none
-
- DDeessccrriippttiioonn This operation returns EOPNOTSUPP.
-
- EErrrroorrss
-
- NNOOTTEE This should perhaps be removed.
-
- 0wpage
-
- 44..2233.. rrddwwrr
-
-
- SSuummmmaarryy Read or write from a file
-
- AArrgguummeennttss
-
- iinn
-
- struct cfs_rdwr_in {
- ViceFid VFid;
- int rwflag;
- int count;
- int offset;
- int ioflag;
- caddr_t data; /* Place holder for data. */
- } cfs_rdwr;
-
-
-
-
- oouutt
-
- struct cfs_rdwr_out {
- int rwflag;
- int count;
- caddr_t data; /* Place holder for data. */
- } cfs_rdwr;
-
-
-
- DDeessccrriippttiioonn This upcall asks Venus to read or write from a file.
-
- EErrrroorrss
-
- NNOOTTEE It should be removed since it is against the Coda philosophy that
- read/write operations never reach Venus. I have been told the
- operation does not work. It is not currently used.
-
-
- 0wpage
-
- 44..2244.. ooddyymmoouunntt
-
-
- SSuummmmaarryy Allows mounting multiple Coda "filesystems" on one Unix mount
- point.
-
- AArrgguummeennttss
-
- iinn
-
- struct ody_mount_in {
- char *name; /* Place holder for data. */
- } ody_mount;
-
-
-
- oouutt
-
- struct ody_mount_out {
- ViceFid VFid;
- } ody_mount;
-
-
-
- DDeessccrriippttiioonn Asks Venus to return the rootfid of a Coda system named
- name. The fid is returned in VFid.
-
- EErrrroorrss
-
- NNOOTTEE This call was used by David for dynamic sets. It should be
- removed since it causes a jungle of pointers in the VFS mounting area.
- It is not used by Coda proper. Call is not implemented by Venus.
-
- 0wpage
-
- 44..2255.. ooddyy__llooookkuupp
-
-
- SSuummmmaarryy Looks up something.
-
- AArrgguummeennttss
-
- iinn irrelevant
-
-
- oouutt
- irrelevant
-
- DDeessccrriippttiioonn
-
- EErrrroorrss
-
- NNOOTTEE Gut it. Call is not implemented by Venus.
-
- 0wpage
-
- 44..2266.. ooddyy__eexxppaanndd
-
-
- SSuummmmaarryy expands something in a dynamic set.
-
- AArrgguummeennttss
-
- iinn irrelevant
-
- oouutt
- irrelevant
-
- DDeessccrriippttiioonn
-
- EErrrroorrss
-
- NNOOTTEE Gut it. Call is not implemented by Venus.
-
- 0wpage
-
- 44..2277.. pprreeffeettcchh
-
-
- SSuummmmaarryy Prefetch a dynamic set.
-
- AArrgguummeennttss
-
- iinn Not documented.
-
- oouutt
- Not documented.
-
- DDeessccrriippttiioonn Venus worker.cc has support for this call, although it is
- noted that it doesn't work. Not surprising, since the kernel does not
- have support for it. (ODY_PREFETCH is not a defined operation).
-
- EErrrroorrss
-
- NNOOTTEE Gut it. It isn't working and isn't used by Coda.
-
-
- 0wpage
-
- 44..2288.. ssiiggnnaall
-
-
- SSuummmmaarryy Send Venus a signal about an upcall.
-
- AArrgguummeennttss
-
- iinn none
-
- oouutt
- not applicable.
-
- DDeessccrriippttiioonn This is an out-of-band upcall to Venus to inform Venus
- that the calling process received a signal after Venus read the
- message from the input queue. Venus is supposed to clean up the
- operation.
-
- EErrrroorrss No reply is given.
-
- NNOOTTEE We need to better understand what Venus needs to clean up and if
- it is doing this correctly. Also we need to handle multiple upcall
- per system call situations correctly. It would be important to know
- what state changes in Venus take place after an upcall for which the
- kernel is responsible for notifying Venus to clean up (e.g. open
- definitely is such a state change, but many others are maybe not).
-
- 0wpage
-
- 55.. TThhee mmiinniiccaacchhee aanndd ddoowwnnccaallllss
-
-
- The Coda FS Driver can cache results of lookup and access upcalls, to
- limit the frequency of upcalls. Upcalls carry a price since a process
- context switch needs to take place. The counterpart of caching the
- information is that Venus will notify the FS Driver that cached
- entries must be flushed or renamed.
-
- The kernel code generally has to maintain a structure which links the
- internal file handles (called vnodes in BSD, inodes in Linux and
- FileHandles in Windows) with the ViceFid's which Venus maintains. The
- reason is that frequent translations back and forth are needed in
- order to make upcalls and use the results of upcalls. Such linking
- objects are called ccnnooddeess.
-
- The current minicache implementations have cache entries which record
- the following:
-
- 1. the name of the file
-
- 2. the cnode of the directory containing the object
-
- 3. a list of CodaCred's for which the lookup is permitted.
-
- 4. the cnode of the object
-
- The lookup call in the Coda FS Driver may request the cnode of the
- desired object from the cache, by passing its name, directory and the
- CodaCred's of the caller. The cache will return the cnode or indicate
- that it cannot be found. The Coda FS Driver must be careful to
- invalidate cache entries when it modifies or removes objects.
-
- When Venus obtains information that indicates that cache entries are
- no longer valid, it will make a downcall to the kernel. Downcalls are
- intercepted by the Coda FS Driver and lead to cache invalidations of
- the kind described below. The Coda FS Driver does not return an error
- unless the downcall data could not be read into kernel memory.
-
-
- 55..11.. IINNVVAALLIIDDAATTEE
-
-
- No information is available on this call.
-
-
- 55..22.. FFLLUUSSHH
-
-
-
- AArrgguummeennttss None
-
- SSuummmmaarryy Flush the name cache entirely.
-
- DDeessccrriippttiioonn Venus issues this call upon startup and when it dies. This
- is to prevent stale cache information being held. Some operating
- systems allow the kernel name cache to be switched off dynamically.
- When this is done, this downcall is made.
-
-
- 55..33.. PPUURRGGEEUUSSEERR
-
-
- AArrgguummeennttss
-
- struct cfs_purgeuser_out {/* CFS_PURGEUSER is a venus->kernel call */
- struct CodaCred cred;
- } cfs_purgeuser;
-
-
-
- DDeessccrriippttiioonn Remove all entries in the cache carrying the Cred. This
- call is issued when tokens for a user expire or are flushed.
-
-
- 55..44.. ZZAAPPFFIILLEE
-
-
- AArrgguummeennttss
-
- struct cfs_zapfile_out { /* CFS_ZAPFILE is a venus->kernel call */
- ViceFid CodaFid;
- } cfs_zapfile;
-
-
-
- DDeessccrriippttiioonn Remove all entries which have the (dir vnode, name) pair.
- This is issued as a result of an invalidation of cached attributes of
- a vnode.
-
- NNOOTTEE Call is not named correctly in NetBSD and Mach. The minicache
- zapfile routine takes different arguments. Linux does not implement
- the invalidation of attributes correctly.
-
-
-
- 55..55.. ZZAAPPDDIIRR
-
-
- AArrgguummeennttss
-
- struct cfs_zapdir_out { /* CFS_ZAPDIR is a venus->kernel call */
- ViceFid CodaFid;
- } cfs_zapdir;
-
-
-
- DDeessccrriippttiioonn Remove all entries in the cache lying in a directory
- CodaFid, and all children of this directory. This call is issued when
- Venus receives a callback on the directory.
-
-
- 55..66.. ZZAAPPVVNNOODDEE
-
-
-
- AArrgguummeennttss
-
- struct cfs_zapvnode_out { /* CFS_ZAPVNODE is a venus->kernel call */
- struct CodaCred cred;
- ViceFid VFid;
- } cfs_zapvnode;
-
-
-
- DDeessccrriippttiioonn Remove all entries in the cache carrying the cred and VFid
- as in the arguments. This downcall is probably never issued.
-
-
- 55..77.. PPUURRGGEEFFIIDD
-
-
- SSuummmmaarryy
-
- AArrgguummeennttss
-
- struct cfs_purgefid_out { /* CFS_PURGEFID is a venus->kernel call */
- ViceFid CodaFid;
- } cfs_purgefid;
-
-
-
- DDeessccrriippttiioonn Flush the attribute for the file. If it is a dir (odd
- vnode), purge its children from the namecache and remove the file from the
- namecache.
-
-
-
- 55..88.. RREEPPLLAACCEE
-
-
- SSuummmmaarryy Replace the Fid's for a collection of names.
-
- AArrgguummeennttss
-
- struct cfs_replace_out { /* cfs_replace is a venus->kernel call */
- ViceFid NewFid;
- ViceFid OldFid;
- } cfs_replace;
-
-
-
- DDeessccrriippttiioonn This routine replaces a ViceFid in the name cache with
- another. It is added to allow Venus during reintegration to replace
- locally allocated temp fids while disconnected with global fids even
- when the reference counts on those fids are not zero.
-
- 0wpage
-
- 66.. IInniittiiaalliizzaattiioonn aanndd cclleeaannuupp
-
-
- This section gives brief hints as to desirable features for the Coda
- FS Driver at startup and upon shutdown or Venus failures. Before
- entering the discussion it is useful to repeat that the Coda FS Driver
- maintains the following data:
-
-
- 1. message queues
-
- 2. cnodes
-
- 3. name cache entries
-
- The name cache entries are entirely private to the driver, so they
- can easily be manipulated. The message queues will generally have
- clear points of initialization and destruction. The cnodes are
- much more delicate. User processes hold reference counts in Coda
- filesystems and it can be difficult to clean up the cnodes.
-
- It can expect requests through:
-
- 1. the message subsystem
-
- 2. the VFS layer
-
- 3. pioctl interface
-
- Currently the _p_i_o_c_t_l passes through the VFS for Coda so we can
- treat these similarly.
-
-
- 66..11.. RReeqquuiirreemmeennttss
-
-
- The following requirements should be accommodated:
-
- 1. The message queues should have open and close routines. On Unix
- the opening of the character devices are such routines.
-
- +o Before opening, no messages can be placed.
-
- +o Opening will remove any old messages still pending.
-
- +o Close will notify any sleeping processes that their upcall cannot
- be completed.
-
- +o Close will free all memory allocated by the message queues.
-
-
- 2. At open the namecache shall be initialized to empty state.
-
- 3. Before the message queues are open, all VFS operations will fail.
- Fortunately this can be achieved by making sure than mounting the
- Coda filesystem cannot succeed before opening.
-
- 4. After closing of the queues, no VFS operations can succeed. Here
- one needs to be careful, since a few operations (lookup,
- read/write, readdir) can proceed without upcalls. These must be
- explicitly blocked.
-
- 5. Upon closing the namecache shall be flushed and disabled.
-
- 6. All memory held by cnodes can be freed without relying on upcalls.
-
- 7. Unmounting the file system can be done without relying on upcalls.
-
- 8. Mounting the Coda filesystem should fail gracefully if Venus cannot
- get the rootfid or the attributes of the rootfid. The latter is
- best implemented by Venus fetching these objects before attempting
- to mount.
-
- NNOOTTEE NetBSD in particular but also Linux have not implemented the
- above requirements fully. For smooth operation this needs to be
- corrected.
-
-
-
diff --git a/Documentation/filesystems/configfs/configfs.txt b/Documentation/filesystems/configfs.rst
similarity index 87%
rename from Documentation/filesystems/configfs/configfs.txt
rename to Documentation/filesystems/configfs.rst
index 16e606c..f894195 100644
--- a/Documentation/filesystems/configfs/configfs.txt
+++ b/Documentation/filesystems/configfs.rst
@@ -1,5 +1,6 @@
-
-configfs - Userspace-driven kernel object configuration.
+=======================================================
+Configfs - Userspace-driven Kernel Object Configuration
+=======================================================
Joel Becker <joel.becker@oracle.com>
@@ -9,7 +10,8 @@
Joel Becker <joel.becker@oracle.com>
-[What is configfs?]
+What is configfs?
+=================
configfs is a ram-based filesystem that provides the converse of
sysfs's functionality. Where sysfs is a filesystem-based view of
@@ -35,10 +37,11 @@
Both sysfs and configfs can and should exist together on the same
system. One is not a replacement for the other.
-[Using configfs]
+Using configfs
+==============
configfs can be compiled as a module or into the kernel. You can access
-it by doing
+it by doing::
mount -t configfs none /config
@@ -56,28 +59,29 @@
There are two types of configfs attributes:
* Normal attributes, which similar to sysfs attributes, are small ASCII text
-files, with a maximum size of one page (PAGE_SIZE, 4096 on i386). Preferably
-only one value per file should be used, and the same caveats from sysfs apply.
-Configfs expects write(2) to store the entire buffer at once. When writing to
-normal configfs attributes, userspace processes should first read the entire
-file, modify the portions they wish to change, and then write the entire
-buffer back.
+ files, with a maximum size of one page (PAGE_SIZE, 4096 on i386). Preferably
+ only one value per file should be used, and the same caveats from sysfs apply.
+ Configfs expects write(2) to store the entire buffer at once. When writing to
+ normal configfs attributes, userspace processes should first read the entire
+ file, modify the portions they wish to change, and then write the entire
+ buffer back.
* Binary attributes, which are somewhat similar to sysfs binary attributes,
-but with a few slight changes to semantics. The PAGE_SIZE limitation does not
-apply, but the whole binary item must fit in single kernel vmalloc'ed buffer.
-The write(2) calls from user space are buffered, and the attributes'
-write_bin_attribute method will be invoked on the final close, therefore it is
-imperative for user-space to check the return code of close(2) in order to
-verify that the operation finished successfully.
-To avoid a malicious user OOMing the kernel, there's a per-binary attribute
-maximum buffer value.
+ but with a few slight changes to semantics. The PAGE_SIZE limitation does not
+ apply, but the whole binary item must fit in single kernel vmalloc'ed buffer.
+ The write(2) calls from user space are buffered, and the attributes'
+ write_bin_attribute method will be invoked on the final close, therefore it is
+ imperative for user-space to check the return code of close(2) in order to
+ verify that the operation finished successfully.
+ To avoid a malicious user OOMing the kernel, there's a per-binary attribute
+ maximum buffer value.
When an item needs to be destroyed, remove it with rmdir(2). An
item cannot be destroyed if any other item has a link to it (via
symlink(2)). Links can be removed via unlink(2).
-[Configuring FakeNBD: an Example]
+Configuring FakeNBD: an Example
+===============================
Imagine there's a Network Block Device (NBD) driver that allows you to
access remote block devices. Call it FakeNBD. FakeNBD uses configfs
@@ -86,14 +90,14 @@
the driver about it. Here's where configfs comes in.
When the FakeNBD driver is loaded, it registers itself with configfs.
-readdir(3) sees this just fine:
+readdir(3) sees this just fine::
# ls /config
fakenbd
A fakenbd connection can be created with mkdir(2). The name is
arbitrary, but likely the tool will make some use of the name. Perhaps
-it is a uuid or a disk name:
+it is a uuid or a disk name::
# mkdir /config/fakenbd/disk1
# ls /config/fakenbd/disk1
@@ -102,7 +106,7 @@
The target attribute contains the IP address of the server FakeNBD will
connect to. The device attribute is the device on the server.
Predictably, the rw attribute determines whether the connection is
-read-only or read-write.
+read-only or read-write::
# echo 10.0.0.1 > /config/fakenbd/disk1/target
# echo /dev/sda1 > /config/fakenbd/disk1/device
@@ -111,7 +115,8 @@
That's it. That's all there is. Now the device is configured, via the
shell no less.
-[Coding With configfs]
+Coding With configfs
+====================
Every object in configfs is a config_item. A config_item reflects an
object in the subsystem. It has attributes that match values on that
@@ -130,7 +135,10 @@
subsystem is also a config_group, and can do everything a config_group
can.
-[struct config_item]
+struct config_item
+==================
+
+::
struct config_item {
char *ci_name;
@@ -168,7 +176,10 @@
Usually a subsystem wants the item to display and/or store attributes,
among other things. For that, it needs a type.
-[struct config_item_type]
+struct config_item_type
+=======================
+
+::
struct configfs_item_operations {
void (*release)(struct config_item *);
@@ -192,7 +203,10 @@
method. This method is called when the config_item's reference count
reaches zero.
-[struct configfs_attribute]
+struct configfs_attribute
+=========================
+
+::
struct configfs_attribute {
char *ca_name;
@@ -214,7 +228,10 @@
attribute is writable and provides a ->store method, that method will be
be called whenever userspace asks for a write(2) on the attribute.
-[struct configfs_bin_attribute]
+struct configfs_bin_attribute
+=============================
+
+::
struct configfs_bin_attribute {
struct configfs_attribute cb_attr;
@@ -240,11 +257,12 @@
single read/write will occur; the attributes' need not concern itself
with it.
-[struct config_group]
+struct config_group
+===================
A config_item cannot live in a vacuum. The only way one can be created
is via mkdir(2) on a config_group. This will trigger creation of a
-child item.
+child item::
struct config_group {
struct config_item cg_item;
@@ -264,7 +282,7 @@
that item means that a group can behave as an item in its own right.
However, it can do more: it can create child items or groups. This is
accomplished via the group operations specified on the group's
-config_item_type.
+config_item_type::
struct configfs_group_operations {
struct config_item *(*make_item)(struct config_group *group,
@@ -279,7 +297,8 @@
};
A group creates child items by providing the
-ct_group_ops->make_item() method. If provided, this method is called from mkdir(2) in the group's directory. The subsystem allocates a new
+ct_group_ops->make_item() method. If provided, this method is called from
+mkdir(2) in the group's directory. The subsystem allocates a new
config_item (or more likely, its container structure), initializes it,
and returns it to configfs. Configfs will then populate the filesystem
tree to reflect the new item.
@@ -296,13 +315,14 @@
the ct_group_ops->drop_item() method, and configfs will call
config_item_put() on the item on behalf of the subsystem.
-IMPORTANT: drop_item() is void, and as such cannot fail. When rmdir(2)
-is called, configfs WILL remove the item from the filesystem tree
-(assuming that it has no children to keep it busy). The subsystem is
-responsible for responding to this. If the subsystem has references to
-the item in other threads, the memory is safe. It may take some time
-for the item to actually disappear from the subsystem's usage. But it
-is gone from configfs.
+Important:
+ drop_item() is void, and as such cannot fail. When rmdir(2)
+ is called, configfs WILL remove the item from the filesystem tree
+ (assuming that it has no children to keep it busy). The subsystem is
+ responsible for responding to this. If the subsystem has references to
+ the item in other threads, the memory is safe. It may take some time
+ for the item to actually disappear from the subsystem's usage. But it
+ is gone from configfs.
When drop_item() is called, the item's linkage has already been torn
down. It no longer has a reference on its parent and has no place in
@@ -319,10 +339,11 @@
called, as the item has not been dropped. rmdir(2) will fail, as the
directory is not empty.
-[struct configfs_subsystem]
+struct configfs_subsystem
+=========================
A subsystem must register itself, usually at module_init time. This
-tells configfs to make the subsystem appear in the file tree.
+tells configfs to make the subsystem appear in the file tree::
struct configfs_subsystem {
struct config_group su_group;
@@ -332,17 +353,19 @@
int configfs_register_subsystem(struct configfs_subsystem *subsys);
void configfs_unregister_subsystem(struct configfs_subsystem *subsys);
- A subsystem consists of a toplevel config_group and a mutex.
+A subsystem consists of a toplevel config_group and a mutex.
The group is where child config_items are created. For a subsystem,
this group is usually defined statically. Before calling
configfs_register_subsystem(), the subsystem must have initialized the
group via the usual group _init() functions, and it must also have
initialized the mutex.
- When the register call returns, the subsystem is live, and it
+
+When the register call returns, the subsystem is live, and it
will be visible via configfs. At that point, mkdir(2) can be called and
the subsystem must be ready for it.
-[An Example]
+An Example
+==========
The best example of these basic concepts is the simple_children
subsystem/group and the simple_child item in
@@ -350,7 +373,8 @@
and storing an attribute, and a simple group creating and destroying
these children.
-[Hierarchy Navigation and the Subsystem Mutex]
+Hierarchy Navigation and the Subsystem Mutex
+============================================
There is an extra bonus that configfs provides. The config_groups and
config_items are arranged in a hierarchy due to the fact that they
@@ -375,7 +399,8 @@
a subsystem to trust ci_parent and cg_children while they hold the
mutex.
-[Item Aggregation Via symlink(2)]
+Item Aggregation Via symlink(2)
+===============================
configfs provides a simple group via the group->item parent/child
relationship. Often, however, a larger environment requires aggregation
@@ -403,7 +428,8 @@
can it be removed while an item links to it. Dangling symlinks are not
allowed in configfs.
-[Automatically Created Subgroups]
+Automatically Created Subgroups
+===============================
A new config_group may want to have two types of child config_items.
While this could be codified by magic names in ->make_item(), it is much
@@ -433,7 +459,8 @@
rmdir(2). They also are not considered when rmdir(2) on the parent
group is checking for children.
-[Dependent Subsystems]
+Dependent Subsystems
+====================
Sometimes other drivers depend on particular configfs items. For
example, ocfs2 mounts depend on a heartbeat region item. If that
@@ -460,9 +487,11 @@
If it fails, it was being torn down anyway, and heartbeat can gracefully
pass up an error.
-[Committable Items]
+Committable Items
+=================
-NOTE: Committable items are currently unimplemented.
+Note:
+ Committable items are currently unimplemented.
Some config_items cannot have a valid initial state. That is, no
default values can be specified for the item's attributes such that the
@@ -504,5 +533,3 @@
shutdown, or "uncommitted". Again, this is done via rename(2), this
time from the "live" directory back to the "pending" one. The subsystem
is notified by the ct_group_ops->uncommit_object() method.
-
-
diff --git a/Documentation/filesystems/dax.txt b/Documentation/filesystems/dax.txt
index 6797294..735f385 100644
--- a/Documentation/filesystems/dax.txt
+++ b/Documentation/filesystems/dax.txt
@@ -74,7 +74,7 @@
exposure of uninitialized data through mmap.
These filesystems may be used for inspiration:
-- ext2: see Documentation/filesystems/ext2.txt
+- ext2: see Documentation/filesystems/ext2.rst
- ext4: see Documentation/filesystems/ext4/
- xfs: see Documentation/admin-guide/xfs.rst
diff --git a/Documentation/filesystems/debugfs.rst b/Documentation/filesystems/debugfs.rst
index 6c032db..1da7a4b 100644
--- a/Documentation/filesystems/debugfs.rst
+++ b/Documentation/filesystems/debugfs.rst
@@ -166,16 +166,17 @@
};
struct debugfs_regset32 {
- struct debugfs_reg32 *regs;
+ const struct debugfs_reg32 *regs;
int nregs;
void __iomem *base;
+ struct device *dev; /* Optional device for Runtime PM */
};
debugfs_create_regset32(const char *name, umode_t mode,
struct dentry *parent,
struct debugfs_regset32 *regset);
- void debugfs_print_regs32(struct seq_file *s, struct debugfs_reg32 *regs,
+ void debugfs_print_regs32(struct seq_file *s, const struct debugfs_reg32 *regs,
int nregs, void __iomem *base, char *prefix);
The "base" argument may be 0, but you may want to build the reg32 array
diff --git a/Documentation/filesystems/devpts.rst b/Documentation/filesystems/devpts.rst
new file mode 100644
index 0000000..a03248d
--- /dev/null
+++ b/Documentation/filesystems/devpts.rst
@@ -0,0 +1,36 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=====================
+The Devpts Filesystem
+=====================
+
+Each mount of the devpts filesystem is now distinct such that ptys
+and their indicies allocated in one mount are independent from ptys
+and their indicies in all other mounts.
+
+All mounts of the devpts filesystem now create a ``/dev/pts/ptmx`` node
+with permissions ``0000``.
+
+To retain backwards compatibility the a ptmx device node (aka any node
+created with ``mknod name c 5 2``) when opened will look for an instance
+of devpts under the name ``pts`` in the same directory as the ptmx device
+node.
+
+As an option instead of placing a ``/dev/ptmx`` device node at ``/dev/ptmx``
+it is possible to place a symlink to ``/dev/pts/ptmx`` at ``/dev/ptmx`` or
+to bind mount ``/dev/ptx/ptmx`` to ``/dev/ptmx``. If you opt for using
+the devpts filesystem in this manner devpts should be mounted with
+the ``ptmxmode=0666``, or ``chmod 0666 /dev/pts/ptmx`` should be called.
+
+Total count of pty pairs in all instances is limited by sysctls::
+
+ kernel.pty.max = 4096 - global limit
+ kernel.pty.reserve = 1024 - reserved for filesystems mounted from the initial mount namespace
+ kernel.pty.nr - current count of ptys
+
+Per-instance limit could be set by adding mount option ``max=<count>``.
+
+This feature was added in kernel 3.4 together with
+``sysctl kernel.pty.reserve``.
+
+In kernels older than 3.4 sysctl ``kernel.pty.max`` works as per-instance limit.
diff --git a/Documentation/filesystems/devpts.txt b/Documentation/filesystems/devpts.txt
deleted file mode 100644
index 9f94fe27..0000000
--- a/Documentation/filesystems/devpts.txt
+++ /dev/null
@@ -1,26 +0,0 @@
-Each mount of the devpts filesystem is now distinct such that ptys
-and their indicies allocated in one mount are independent from ptys
-and their indicies in all other mounts.
-
-All mounts of the devpts filesystem now create a /dev/pts/ptmx node
-with permissions 0000.
-
-To retain backwards compatibility the a ptmx device node (aka any node
-created with "mknod name c 5 2") when opened will look for an instance
-of devpts under the name "pts" in the same directory as the ptmx device
-node.
-
-As an option instead of placing a /dev/ptmx device node at /dev/ptmx
-it is possible to place a symlink to /dev/pts/ptmx at /dev/ptmx or
-to bind mount /dev/ptx/ptmx to /dev/ptmx. If you opt for using
-the devpts filesystem in this manner devpts should be mounted with
-the ptmxmode=0666, or chmod 0666 /dev/pts/ptmx should be called.
-
-Total count of pty pairs in all instances is limited by sysctls:
-kernel.pty.max = 4096 - global limit
-kernel.pty.reserve = 1024 - reserved for filesystems mounted from the initial mount namespace
-kernel.pty.nr - current count of ptys
-
-Per-instance limit could be set by adding mount option "max=<count>".
-This feature was added in kernel 3.4 together with sysctl kernel.pty.reserve.
-In kernels older than 3.4 sysctl kernel.pty.max works as per-instance limit.
diff --git a/Documentation/filesystems/dnotify.txt b/Documentation/filesystems/dnotify.rst
similarity index 88%
rename from Documentation/filesystems/dnotify.txt
rename to Documentation/filesystems/dnotify.rst
index 1515688..a28a1f9 100644
--- a/Documentation/filesystems/dnotify.txt
+++ b/Documentation/filesystems/dnotify.rst
@@ -1,5 +1,8 @@
- Linux Directory Notification
- ============================
+.. SPDX-License-Identifier: GPL-2.0
+
+============================
+Linux Directory Notification
+============================
Stephen Rothwell <sfr@canb.auug.org.au>
@@ -12,6 +15,7 @@
The application decides which "events" it wants to be notified about.
The currently defined events are:
+ ========= =====================================================
DN_ACCESS A file in the directory was accessed (read)
DN_MODIFY A file in the directory was modified (write,truncate)
DN_CREATE A file was created in the directory
@@ -19,6 +23,7 @@
DN_RENAME A file in the directory was renamed
DN_ATTRIB A file in the directory had its attributes
changed (chmod,chown)
+ ========= =====================================================
Usually, the application must reregister after each notification, but
if DN_MULTISHOT is or'ed with the event mask, then the registration will
@@ -36,7 +41,7 @@
is often blocked, so it is better to use (at least) SIGRTMIN + 1.
Implementation expectations (features and bugs :-))
----------------------------
+---------------------------------------------------
The notification should work for any local access to files even if the
actual file system is on a remote server. This implies that remote
@@ -67,4 +72,4 @@
NOTE
----
Beginning with Linux 2.6.13, dnotify has been replaced by inotify.
-See Documentation/filesystems/inotify.txt for more information on it.
+See Documentation/filesystems/inotify.rst for more information on it.
diff --git a/Documentation/filesystems/efivarfs.rst b/Documentation/filesystems/efivarfs.rst
index 90ac656..0551985 100644
--- a/Documentation/filesystems/efivarfs.rst
+++ b/Documentation/filesystems/efivarfs.rst
@@ -24,3 +24,20 @@
as immutable files. This doesn't prevent removal - "chattr -i" will work -
but it does prevent this kind of failure from being accomplished
accidentally.
+
+.. warning ::
+ When a content of an UEFI variable in /sys/firmware/efi/efivars is
+ displayed, for example using "hexdump", pay attention that the first
+ 4 bytes of the output represent the UEFI variable attributes,
+ in little-endian format.
+
+ Practically the output of each efivar is composed of:
+
+ +-----------------------------------+
+ |4_bytes_of_attributes + efivar_data|
+ +-----------------------------------+
+
+*See also:*
+
+- Documentation/admin-guide/acpi/ssdt-overlays.rst
+- Documentation/ABI/stable/sysfs-firmware-efi-vars
diff --git a/Documentation/filesystems/fiemap.txt b/Documentation/filesystems/fiemap.rst
similarity index 70%
rename from Documentation/filesystems/fiemap.txt
rename to Documentation/filesystems/fiemap.rst
index ac87e6f..2a572e7 100644
--- a/Documentation/filesystems/fiemap.txt
+++ b/Documentation/filesystems/fiemap.rst
@@ -1,3 +1,5 @@
+.. SPDX-License-Identifier: GPL-2.0
+
============
Fiemap Ioctl
============
@@ -10,9 +12,9 @@
Request Basics
--------------
-A fiemap request is encoded within struct fiemap:
+A fiemap request is encoded within struct fiemap::
-struct fiemap {
+ struct fiemap {
__u64 fm_start; /* logical offset (inclusive) at
* which to start mapping (in) */
__u64 fm_length; /* logical length of mapping which
@@ -23,7 +25,7 @@
__u32 fm_extent_count; /* size of fm_extents array (in) */
__u32 fm_reserved;
struct fiemap_extent fm_extents[0]; /* array of mapped extents (out) */
-};
+ };
fm_start, and fm_length specify the logical range within the file
@@ -51,12 +53,12 @@
The following flags can be set in fm_flags:
-* FIEMAP_FLAG_SYNC
-If this flag is set, the kernel will sync the file before mapping extents.
+FIEMAP_FLAG_SYNC
+ If this flag is set, the kernel will sync the file before mapping extents.
-* FIEMAP_FLAG_XATTR
-If this flag is set, the extents returned will describe the inodes
-extended attribute lookup tree, instead of its data tree.
+FIEMAP_FLAG_XATTR
+ If this flag is set, the extents returned will describe the inodes
+ extended attribute lookup tree, instead of its data tree.
Extent Mapping
@@ -75,18 +77,18 @@
flag set (see the next section on extent flags).
Each extent is described by a single fiemap_extent structure as
-returned in fm_extents.
+returned in fm_extents::
-struct fiemap_extent {
- __u64 fe_logical; /* logical offset in bytes for the start of
- * the extent */
- __u64 fe_physical; /* physical offset in bytes for the start
- * of the extent */
- __u64 fe_length; /* length in bytes for the extent */
- __u64 fe_reserved64[2];
- __u32 fe_flags; /* FIEMAP_EXTENT_* flags for this extent */
- __u32 fe_reserved[3];
-};
+ struct fiemap_extent {
+ __u64 fe_logical; /* logical offset in bytes for the start of
+ * the extent */
+ __u64 fe_physical; /* physical offset in bytes for the start
+ * of the extent */
+ __u64 fe_length; /* length in bytes for the extent */
+ __u64 fe_reserved64[2];
+ __u32 fe_flags; /* FIEMAP_EXTENT_* flags for this extent */
+ __u32 fe_reserved[3];
+ };
All offsets and lengths are in bytes and mirror those on disk. It is valid
for an extents logical offset to start before the request or its logical
@@ -114,26 +116,27 @@
data. Note that the opposite is not true - it would be valid for
FIEMAP_EXTENT_NOT_ALIGNED to appear alone.
-* FIEMAP_EXTENT_LAST
-This is generally the last extent in the file. A mapping attempt past
-this extent may return nothing. Some implementations set this flag to
-indicate this extent is the last one in the range queried by the user
-(via fiemap->fm_length).
+FIEMAP_EXTENT_LAST
+ This is generally the last extent in the file. A mapping attempt past
+ this extent may return nothing. Some implementations set this flag to
+ indicate this extent is the last one in the range queried by the user
+ (via fiemap->fm_length).
-* FIEMAP_EXTENT_UNKNOWN
-The location of this extent is currently unknown. This may indicate
-the data is stored on an inaccessible volume or that no storage has
-been allocated for the file yet.
+FIEMAP_EXTENT_UNKNOWN
+ The location of this extent is currently unknown. This may indicate
+ the data is stored on an inaccessible volume or that no storage has
+ been allocated for the file yet.
-* FIEMAP_EXTENT_DELALLOC
- - This will also set FIEMAP_EXTENT_UNKNOWN.
-Delayed allocation - while there is data for this extent, its
-physical location has not been allocated yet.
+FIEMAP_EXTENT_DELALLOC
+ This will also set FIEMAP_EXTENT_UNKNOWN.
-* FIEMAP_EXTENT_ENCODED
-This extent does not consist of plain filesystem blocks but is
-encoded (e.g. encrypted or compressed). Reading the data in this
-extent via I/O to the block device will have undefined results.
+ Delayed allocation - while there is data for this extent, its
+ physical location has not been allocated yet.
+
+FIEMAP_EXTENT_ENCODED
+ This extent does not consist of plain filesystem blocks but is
+ encoded (e.g. encrypted or compressed). Reading the data in this
+ extent via I/O to the block device will have undefined results.
Note that it is *always* undefined to try to update the data
in-place by writing to the indicated location without the
@@ -145,32 +148,32 @@
clear; user applications must not try reading or writing to the
filesystem via the block device under any other circumstances.
-* FIEMAP_EXTENT_DATA_ENCRYPTED
- - This will also set FIEMAP_EXTENT_ENCODED
-The data in this extent has been encrypted by the file system.
+FIEMAP_EXTENT_DATA_ENCRYPTED
+ This will also set FIEMAP_EXTENT_ENCODED
+ The data in this extent has been encrypted by the file system.
-* FIEMAP_EXTENT_NOT_ALIGNED
-Extent offsets and length are not guaranteed to be block aligned.
+FIEMAP_EXTENT_NOT_ALIGNED
+ Extent offsets and length are not guaranteed to be block aligned.
-* FIEMAP_EXTENT_DATA_INLINE
+FIEMAP_EXTENT_DATA_INLINE
This will also set FIEMAP_EXTENT_NOT_ALIGNED
-Data is located within a meta data block.
+ Data is located within a meta data block.
-* FIEMAP_EXTENT_DATA_TAIL
+FIEMAP_EXTENT_DATA_TAIL
This will also set FIEMAP_EXTENT_NOT_ALIGNED
-Data is packed into a block with data from other files.
+ Data is packed into a block with data from other files.
-* FIEMAP_EXTENT_UNWRITTEN
-Unwritten extent - the extent is allocated but its data has not been
-initialized. This indicates the extent's data will be all zero if read
-through the filesystem but the contents are undefined if read directly from
-the device.
+FIEMAP_EXTENT_UNWRITTEN
+ Unwritten extent - the extent is allocated but its data has not been
+ initialized. This indicates the extent's data will be all zero if read
+ through the filesystem but the contents are undefined if read directly from
+ the device.
-* FIEMAP_EXTENT_MERGED
-This will be set when a file does not support extents, i.e., it uses a block
-based addressing scheme. Since returning an extent for each block back to
-userspace would be highly inefficient, the kernel will try to merge most
-adjacent blocks into 'extents'.
+FIEMAP_EXTENT_MERGED
+ This will be set when a file does not support extents, i.e., it uses a block
+ based addressing scheme. Since returning an extent for each block back to
+ userspace would be highly inefficient, the kernel will try to merge most
+ adjacent blocks into 'extents'.
VFS -> File System Implementation
@@ -179,23 +182,23 @@
File systems wishing to support fiemap must implement a ->fiemap callback on
their inode_operations structure. The fs ->fiemap call is responsible for
defining its set of supported fiemap flags, and calling a helper function on
-each discovered extent:
+each discovered extent::
-struct inode_operations {
+ struct inode_operations {
...
int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,
u64 len);
->fiemap is passed struct fiemap_extent_info which describes the
-fiemap request:
+fiemap request::
-struct fiemap_extent_info {
+ struct fiemap_extent_info {
unsigned int fi_flags; /* Flags as passed from user */
unsigned int fi_extents_mapped; /* Number of mapped extents */
unsigned int fi_extents_max; /* Size of fiemap_extent array */
struct fiemap_extent *fi_extents_start; /* Start of fiemap_extent array */
-};
+ };
It is intended that the file system should not need to access any of this
structure directly. Filesystem handlers should be tolerant to signals and return
@@ -203,9 +206,9 @@
Flag checking should be done at the beginning of the ->fiemap callback via the
-fiemap_check_flags() helper:
+fiemap_check_flags() helper::
-int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
+ int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
The struct fieinfo should be passed in as received from ioctl_fiemap(). The
set of fiemap flags which the fs understands should be passed via fs_flags. If
@@ -216,10 +219,10 @@
For each extent in the request range, the file system should call
-the helper function, fiemap_fill_next_extent():
+the helper function, fiemap_fill_next_extent()::
-int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical,
- u64 phys, u64 len, u32 flags, u32 dev);
+ int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical,
+ u64 phys, u64 len, u32 flags, u32 dev);
fiemap_fill_next_extent() will use the passed values to populate the
next free extent in the fm_extents array. 'General' extent flags will
diff --git a/Documentation/filesystems/files.txt b/Documentation/filesystems/files.rst
similarity index 95%
rename from Documentation/filesystems/files.txt
rename to Documentation/filesystems/files.rst
index 46dfc6b..cbf8e57 100644
--- a/Documentation/filesystems/files.txt
+++ b/Documentation/filesystems/files.rst
@@ -1,5 +1,8 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===================================
File management in the Linux kernel
------------------------------------
+===================================
This document describes how locking for files (struct file)
and file descriptor table (struct files) works.
@@ -34,7 +37,7 @@
the fdtable structure -
1. All references to the fdtable must be done through
- the files_fdtable() macro :
+ the files_fdtable() macro::
struct fdtable *fdt;
@@ -61,7 +64,8 @@
4. To look up the file structure given an fd, a reader
must use either fcheck() or fcheck_files() APIs. These
take care of barrier requirements due to lock-free lookup.
- An example :
+
+ An example::
struct file *file;
@@ -77,7 +81,7 @@
of the fd (fget()/fget_light()) are lock-free, it is possible
that look-up may race with the last put() operation on the
file structure. This is avoided using atomic_long_inc_not_zero()
- on ->f_count :
+ on ->f_count::
rcu_read_lock();
file = fcheck_files(files, fd);
@@ -106,7 +110,8 @@
holding files->file_lock. If ->file_lock is dropped, then
another thread expand the files thereby creating a new
fdtable and making the earlier fdtable pointer stale.
- For example :
+
+ For example::
spin_lock(&files->file_lock);
fd = locate_fd(files, file, start);
diff --git a/Documentation/filesystems/fuse-io.txt b/Documentation/filesystems/fuse-io.rst
similarity index 95%
rename from Documentation/filesystems/fuse-io.txt
rename to Documentation/filesystems/fuse-io.rst
index 07b8f73f..255a368 100644
--- a/Documentation/filesystems/fuse-io.txt
+++ b/Documentation/filesystems/fuse-io.rst
@@ -1,3 +1,9 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==============
+Fuse I/O Modes
+==============
+
Fuse supports the following I/O modes:
- direct-io
diff --git a/Documentation/filesystems/index.rst b/Documentation/filesystems/index.rst
index e7b46da..1779534 100644
--- a/Documentation/filesystems/index.rst
+++ b/Documentation/filesystems/index.rst
@@ -24,6 +24,22 @@
splice
locking
directory-locking
+ devpts
+ dnotify
+ fiemap
+ files
+ locks
+ mandatory-locking
+ mount_api
+ quota
+ seq_file
+ sharedsubtree
+ sysfs-pci
+ sysfs-tagging
+
+ automount-support
+
+ caching/index
porting
@@ -57,7 +73,10 @@
befs
bfs
btrfs
+ cifs/cifsroot
ceph
+ coda
+ configfs
cramfs
debugfs
dlmfs
@@ -73,6 +92,7 @@
hfsplus
hpfs
fuse
+ fuse-io
inotify
isofs
nilfs2
@@ -88,6 +108,7 @@
ramfs-rootfs-initramfs
relay
romfs
+ spufs/index
squashfs
sysfs
sysv-fs
@@ -97,4 +118,6 @@
udf
virtiofs
vfat
+ xfs-delayed-logging-design
+ xfs-self-describing-metadata
zonefs
diff --git a/Documentation/filesystems/locks.txt b/Documentation/filesystems/locks.rst
similarity index 90%
rename from Documentation/filesystems/locks.txt
rename to Documentation/filesystems/locks.rst
index 5368690..c5ae858 100644
--- a/Documentation/filesystems/locks.txt
+++ b/Documentation/filesystems/locks.rst
@@ -1,4 +1,8 @@
- File Locking Release Notes
+.. SPDX-License-Identifier: GPL-2.0
+
+==========================
+File Locking Release Notes
+==========================
Andy Walker <andy@lysaker.kvaerner.no>
@@ -6,7 +10,7 @@
1. What's New?
---------------
+==============
1.1 Broken Flock Emulation
--------------------------
@@ -25,7 +29,7 @@
---------------------------
1.2.1 Typical Problems - Sendmail
----------------------------------
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
Because sendmail was unable to use the old flock() emulation, many sendmail
installations use fcntl() instead of flock(). This is true of Slackware 3.0
for example. This gave rise to some other subtle problems if sendmail was
@@ -37,7 +41,7 @@
1.2.2 The Solution
-------------------
+^^^^^^^^^^^^^^^^^^
The solution I have chosen, after much experimentation and discussion,
is to make flock() and fcntl() locks oblivious to each other. Both can
exists, and neither will have any effect on the other.
@@ -54,7 +58,7 @@
---------------------------------------
Mandatory locking, as described in
-'Documentation/filesystems/mandatory-locking.txt' was prior to this release a
+'Documentation/filesystems/mandatory-locking.rst' was prior to this release a
general configuration option that was valid for all mounted filesystems. This
had a number of inherent dangers, not the least of which was the ability to
freeze an NFS server by asking it to read a file for which a mandatory lock
diff --git a/Documentation/filesystems/mandatory-locking.txt b/Documentation/filesystems/mandatory-locking.rst
similarity index 90%
rename from Documentation/filesystems/mandatory-locking.txt
rename to Documentation/filesystems/mandatory-locking.rst
index a251ca3..9ce7354 100644
--- a/Documentation/filesystems/mandatory-locking.txt
+++ b/Documentation/filesystems/mandatory-locking.rst
@@ -1,8 +1,13 @@
- Mandatory File Locking For The Linux Operating System
+.. SPDX-License-Identifier: GPL-2.0
+
+=====================================================
+Mandatory File Locking For The Linux Operating System
+=====================================================
Andy Walker <andy@lysaker.kvaerner.no>
15 April 1996
+
(Updated September 2007)
0. Why you should avoid mandatory locking
@@ -53,15 +58,17 @@
as candidates for mandatory locking, and using the existing fcntl()/lockf()
interface for applying locks just as if they were normal, advisory locks.
-Note 1: In saying "file" in the paragraphs above I am actually not telling
-the whole truth. System V locking is based on fcntl(). The granularity of
-fcntl() is such that it allows the locking of byte ranges in files, in addition
-to entire files, so the mandatory locking rules also have byte level
-granularity.
+.. Note::
-Note 2: POSIX.1 does not specify any scheme for mandatory locking, despite
-borrowing the fcntl() locking scheme from System V. The mandatory locking
-scheme is defined by the System V Interface Definition (SVID) Version 3.
+ 1. In saying "file" in the paragraphs above I am actually not telling
+ the whole truth. System V locking is based on fcntl(). The granularity of
+ fcntl() is such that it allows the locking of byte ranges in files, in
+ addition to entire files, so the mandatory locking rules also have byte
+ level granularity.
+
+ 2. POSIX.1 does not specify any scheme for mandatory locking, despite
+ borrowing the fcntl() locking scheme from System V. The mandatory locking
+ scheme is defined by the System V Interface Definition (SVID) Version 3.
2. Marking a file for mandatory locking
---------------------------------------
diff --git a/Documentation/filesystems/mount_api.txt b/Documentation/filesystems/mount_api.rst
similarity index 79%
rename from Documentation/filesystems/mount_api.txt
rename to Documentation/filesystems/mount_api.rst
index 87c14bb..dea22d6 100644
--- a/Documentation/filesystems/mount_api.txt
+++ b/Documentation/filesystems/mount_api.rst
@@ -1,8 +1,10 @@
- ====================
- FILESYSTEM MOUNT API
- ====================
+.. SPDX-License-Identifier: GPL-2.0
-CONTENTS
+====================
+fILESYSTEM Mount API
+====================
+
+.. CONTENTS
(1) Overview.
@@ -21,8 +23,7 @@
(8) Parameter helper functions.
-========
-OVERVIEW
+Overview
========
The creation of new mounts is now to be done in a multistep process:
@@ -43,7 +44,7 @@
(7) Destroy the context.
-To support this, the file_system_type struct gains two new fields:
+To support this, the file_system_type struct gains two new fields::
int (*init_fs_context)(struct fs_context *fc);
const struct fs_parameter_description *parameters;
@@ -57,12 +58,11 @@
that the namespaces may be adjusted first.
-======================
-THE FILESYSTEM CONTEXT
+The Filesystem context
======================
The creation and reconfiguration of a superblock is governed by a filesystem
-context. This is represented by the fs_context structure:
+context. This is represented by the fs_context structure::
struct fs_context {
const struct fs_context_operations *ops;
@@ -86,78 +86,106 @@
The fs_context fields are as follows:
- (*) const struct fs_context_operations *ops
+ * ::
+
+ const struct fs_context_operations *ops
These are operations that can be done on a filesystem context (see
below). This must be set by the ->init_fs_context() file_system_type
operation.
- (*) struct file_system_type *fs_type
+ * ::
+
+ struct file_system_type *fs_type
A pointer to the file_system_type of the filesystem that is being
constructed or reconfigured. This retains a reference on the type owner.
- (*) void *fs_private
+ * ::
+
+ void *fs_private
A pointer to the file system's private data. This is where the filesystem
will need to store any options it parses.
- (*) struct dentry *root
+ * ::
+
+ struct dentry *root
A pointer to the root of the mountable tree (and indirectly, the
superblock thereof). This is filled in by the ->get_tree() op. If this
is set, an active reference on root->d_sb must also be held.
- (*) struct user_namespace *user_ns
- (*) struct net *net_ns
+ * ::
+
+ struct user_namespace *user_ns
+ struct net *net_ns
There are a subset of the namespaces in use by the invoking process. They
retain references on each namespace. The subscribed namespaces may be
replaced by the filesystem to reflect other sources, such as the parent
mount superblock on an automount.
- (*) const struct cred *cred
+ * ::
+
+ const struct cred *cred
The mounter's credentials. This retains a reference on the credentials.
- (*) char *source
+ * ::
+
+ char *source
This specifies the source. It may be a block device (e.g. /dev/sda1) or
something more exotic, such as the "host:/path" that NFS desires.
- (*) char *subtype
+ * ::
+
+ char *subtype
This is a string to be added to the type displayed in /proc/mounts to
qualify it (used by FUSE). This is available for the filesystem to set if
desired.
- (*) void *security
+ * ::
+
+ void *security
A place for the LSMs to hang their security data for the superblock. The
relevant security operations are described below.
- (*) void *s_fs_info
+ * ::
+
+ void *s_fs_info
The proposed s_fs_info for a new superblock, set in the superblock by
sget_fc(). This can be used to distinguish superblocks.
- (*) unsigned int sb_flags
- (*) unsigned int sb_flags_mask
+ * ::
+
+ unsigned int sb_flags
+ unsigned int sb_flags_mask
Which bits SB_* flags are to be set/cleared in super_block::s_flags.
- (*) unsigned int s_iflags
+ * ::
+
+ unsigned int s_iflags
These will be bitwise-OR'd with s->s_iflags when a superblock is created.
- (*) enum fs_context_purpose
+ * ::
+
+ enum fs_context_purpose
This indicates the purpose for which the context is intended. The
available values are:
- FS_CONTEXT_FOR_MOUNT, -- New superblock for explicit mount
- FS_CONTEXT_FOR_SUBMOUNT -- New automatic submount of extant mount
- FS_CONTEXT_FOR_RECONFIGURE -- Change an existing mount
+ ========================== ======================================
+ FS_CONTEXT_FOR_MOUNT, New superblock for explicit mount
+ FS_CONTEXT_FOR_SUBMOUNT New automatic submount of extant mount
+ FS_CONTEXT_FOR_RECONFIGURE Change an existing mount
+ ========================== ======================================
The mount context is created by calling vfs_new_fs_context() or
vfs_dup_fs_context() and is destroyed with put_fs_context(). Note that the
@@ -176,11 +204,10 @@
module.
-=================================
-THE FILESYSTEM CONTEXT OPERATIONS
+The Filesystem Context Operations
=================================
-The filesystem context points to a table of operations:
+The filesystem context points to a table of operations::
struct fs_context_operations {
void (*free)(struct fs_context *fc);
@@ -195,24 +222,32 @@
These operations are invoked by the various stages of the mount procedure to
manage the filesystem context. They are as follows:
- (*) void (*free)(struct fs_context *fc);
+ * ::
+
+ void (*free)(struct fs_context *fc);
Called to clean up the filesystem-specific part of the filesystem context
when the context is destroyed. It should be aware that parts of the
context may have been removed and NULL'd out by ->get_tree().
- (*) int (*dup)(struct fs_context *fc, struct fs_context *src_fc);
+ * ::
+
+ int (*dup)(struct fs_context *fc, struct fs_context *src_fc);
Called when a filesystem context has been duplicated to duplicate the
filesystem-private data. An error may be returned to indicate failure to
do this.
- [!] Note that even if this fails, put_fs_context() will be called
+ .. Warning::
+
+ Note that even if this fails, put_fs_context() will be called
immediately thereafter, so ->dup() *must* make the
filesystem-private data safe for ->free().
- (*) int (*parse_param)(struct fs_context *fc,
- struct struct fs_parameter *param);
+ * ::
+
+ int (*parse_param)(struct fs_context *fc,
+ struct struct fs_parameter *param);
Called when a parameter is being added to the filesystem context. param
points to the key name and maybe a value object. VFS-specific options
@@ -224,7 +259,9 @@
If successful, 0 should be returned or a negative error code otherwise.
- (*) int (*parse_monolithic)(struct fs_context *fc, void *data);
+ * ::
+
+ int (*parse_monolithic)(struct fs_context *fc, void *data);
Called when the mount(2) system call is invoked to pass the entire data
page in one go. If this is expected to be just a list of "key[=val]"
@@ -236,7 +273,9 @@
finds it's the standard key-val list then it may pass it off to
generic_parse_monolithic().
- (*) int (*get_tree)(struct fs_context *fc);
+ * ::
+
+ int (*get_tree)(struct fs_context *fc);
Called to get or create the mountable root and superblock, using the
information stored in the filesystem context (reconfiguration goes via a
@@ -249,7 +288,9 @@
The phase on a userspace-driven context will be set to only allow this to
be called once on any particular context.
- (*) int (*reconfigure)(struct fs_context *fc);
+ * ::
+
+ int (*reconfigure)(struct fs_context *fc);
Called to effect reconfiguration of a superblock using information stored
in the filesystem context. It may detach any resources it desires from
@@ -259,19 +300,20 @@
On success it should return 0. In the case of an error, it should return
a negative error code.
- [NOTE] reconfigure is intended as a replacement for remount_fs.
+ .. Note:: reconfigure is intended as a replacement for remount_fs.
-===========================
-FILESYSTEM CONTEXT SECURITY
+Filesystem context Security
===========================
The filesystem context contains a security pointer that the LSMs can use for
building up a security context for the superblock to be mounted. There are a
number of operations used by the new mount code for this purpose:
- (*) int security_fs_context_alloc(struct fs_context *fc,
- struct dentry *reference);
+ * ::
+
+ int security_fs_context_alloc(struct fs_context *fc,
+ struct dentry *reference);
Called to initialise fc->security (which is preset to NULL) and allocate
any resources needed. It should return 0 on success or a negative error
@@ -283,22 +325,28 @@
non-NULL in the case of a submount (FS_CONTEXT_FOR_SUBMOUNT) in which case
it indicates the automount point.
- (*) int security_fs_context_dup(struct fs_context *fc,
- struct fs_context *src_fc);
+ * ::
+
+ int security_fs_context_dup(struct fs_context *fc,
+ struct fs_context *src_fc);
Called to initialise fc->security (which is preset to NULL) and allocate
any resources needed. The original filesystem context is pointed to by
src_fc and may be used for reference. It should return 0 on success or a
negative error code on failure.
- (*) void security_fs_context_free(struct fs_context *fc);
+ * ::
+
+ void security_fs_context_free(struct fs_context *fc);
Called to clean up anything attached to fc->security. Note that the
contents may have been transferred to a superblock and the pointer cleared
during get_tree.
- (*) int security_fs_context_parse_param(struct fs_context *fc,
- struct fs_parameter *param);
+ * ::
+
+ int security_fs_context_parse_param(struct fs_context *fc,
+ struct fs_parameter *param);
Called for each mount parameter, including the source. The arguments are
as for the ->parse_param() method. It should return 0 to indicate that
@@ -310,7 +358,9 @@
(provided the value pointer is NULL'd out). If it is stolen, 1 must be
returned to prevent it being passed to the filesystem.
- (*) int security_fs_context_validate(struct fs_context *fc);
+ * ::
+
+ int security_fs_context_validate(struct fs_context *fc);
Called after all the options have been parsed to validate the collection
as a whole and to do any necessary allocation so that
@@ -320,36 +370,43 @@
In the case of reconfiguration, the target superblock will be accessible
via fc->root.
- (*) int security_sb_get_tree(struct fs_context *fc);
+ * ::
+
+ int security_sb_get_tree(struct fs_context *fc);
Called during the mount procedure to verify that the specified superblock
is allowed to be mounted and to transfer the security data there. It
should return 0 or a negative error code.
- (*) void security_sb_reconfigure(struct fs_context *fc);
+ * ::
+
+ void security_sb_reconfigure(struct fs_context *fc);
Called to apply any reconfiguration to an LSM's context. It must not
fail. Error checking and resource allocation must be done in advance by
the parameter parsing and validation hooks.
- (*) int security_sb_mountpoint(struct fs_context *fc, struct path *mountpoint,
- unsigned int mnt_flags);
+ * ::
+
+ int security_sb_mountpoint(struct fs_context *fc,
+ struct path *mountpoint,
+ unsigned int mnt_flags);
Called during the mount procedure to verify that the root dentry attached
to the context is permitted to be attached to the specified mountpoint.
It should return 0 on success or a negative error code on failure.
-==========================
-VFS FILESYSTEM CONTEXT API
+VFS Filesystem context API
==========================
There are four operations for creating a filesystem context and one for
destroying a context:
- (*) struct fs_context *fs_context_for_mount(
- struct file_system_type *fs_type,
- unsigned int sb_flags);
+ * ::
+
+ struct fs_context *fs_context_for_mount(struct file_system_type *fs_type,
+ unsigned int sb_flags);
Allocate a filesystem context for the purpose of setting up a new mount,
whether that be with a new superblock or sharing an existing one. This
@@ -359,7 +416,9 @@
fs_type specifies the filesystem type that will manage the context and
sb_flags presets the superblock flags stored therein.
- (*) struct fs_context *fs_context_for_reconfigure(
+ * ::
+
+ struct fs_context *fs_context_for_reconfigure(
struct dentry *dentry,
unsigned int sb_flags,
unsigned int sb_flags_mask);
@@ -369,7 +428,9 @@
configured. sb_flags and sb_flags_mask indicate which superblock flags
need changing and to what.
- (*) struct fs_context *fs_context_for_submount(
+ * ::
+
+ struct fs_context *fs_context_for_submount(
struct file_system_type *fs_type,
struct dentry *reference);
@@ -382,7 +443,9 @@
Note that it's not a requirement that the reference dentry be of the same
filesystem type as fs_type.
- (*) struct fs_context *vfs_dup_fs_context(struct fs_context *src_fc);
+ * ::
+
+ struct fs_context *vfs_dup_fs_context(struct fs_context *src_fc);
Duplicate a filesystem context, copying any options noted and duplicating
or additionally referencing any resources held therein. This is available
@@ -392,14 +455,18 @@
The purpose in the new context is inherited from the old one.
- (*) void put_fs_context(struct fs_context *fc);
+ * ::
+
+ void put_fs_context(struct fs_context *fc);
Destroy a filesystem context, releasing any resources it holds. This
calls the ->free() operation. This is intended to be called by anyone who
created a filesystem context.
- [!] filesystem contexts are not refcounted, so this causes unconditional
- destruction.
+ .. Warning::
+
+ filesystem contexts are not refcounted, so this causes unconditional
+ destruction.
In all the above operations, apart from the put op, the return is a mount
context pointer or a negative error code.
@@ -407,8 +474,10 @@
For the remaining operations, if an error occurs, a negative error code will be
returned.
- (*) int vfs_parse_fs_param(struct fs_context *fc,
- struct fs_parameter *param);
+ * ::
+
+ int vfs_parse_fs_param(struct fs_context *fc,
+ struct fs_parameter *param);
Supply a single mount parameter to the filesystem context. This include
the specification of the source/device which is specified as the "source"
@@ -423,53 +492,64 @@
The parameter value is typed and can be one of:
- fs_value_is_flag, Parameter not given a value.
- fs_value_is_string, Value is a string
- fs_value_is_blob, Value is a binary blob
- fs_value_is_filename, Value is a filename* + dirfd
- fs_value_is_file, Value is an open file (file*)
+ ==================== =============================
+ fs_value_is_flag Parameter not given a value
+ fs_value_is_string Value is a string
+ fs_value_is_blob Value is a binary blob
+ fs_value_is_filename Value is a filename* + dirfd
+ fs_value_is_file Value is an open file (file*)
+ ==================== =============================
If there is a value, that value is stored in a union in the struct in one
of param->{string,blob,name,file}. Note that the function may steal and
clear the pointer, but then becomes responsible for disposing of the
object.
- (*) int vfs_parse_fs_string(struct fs_context *fc, const char *key,
- const char *value, size_t v_size);
+ * ::
+
+ int vfs_parse_fs_string(struct fs_context *fc, const char *key,
+ const char *value, size_t v_size);
A wrapper around vfs_parse_fs_param() that copies the value string it is
passed.
- (*) int generic_parse_monolithic(struct fs_context *fc, void *data);
+ * ::
+
+ int generic_parse_monolithic(struct fs_context *fc, void *data);
Parse a sys_mount() data page, assuming the form to be a text list
consisting of key[=val] options separated by commas. Each item in the
list is passed to vfs_mount_option(). This is the default when the
->parse_monolithic() method is NULL.
- (*) int vfs_get_tree(struct fs_context *fc);
+ * ::
+
+ int vfs_get_tree(struct fs_context *fc);
Get or create the mountable root and superblock, using the parameters in
the filesystem context to select/configure the superblock. This invokes
the ->get_tree() method.
- (*) struct vfsmount *vfs_create_mount(struct fs_context *fc);
+ * ::
+
+ struct vfsmount *vfs_create_mount(struct fs_context *fc);
Create a mount given the parameters in the specified filesystem context.
Note that this does not attach the mount to anything.
-===========================
-SUPERBLOCK CREATION HELPERS
+Superblock Creation Helpers
===========================
A number of VFS helpers are available for use by filesystems for the creation
or looking up of superblocks.
- (*) struct super_block *
- sget_fc(struct fs_context *fc,
- int (*test)(struct super_block *sb, struct fs_context *fc),
- int (*set)(struct super_block *sb, struct fs_context *fc));
+ * ::
+
+ struct super_block *
+ sget_fc(struct fs_context *fc,
+ int (*test)(struct super_block *sb, struct fs_context *fc),
+ int (*set)(struct super_block *sb, struct fs_context *fc));
This is the core routine. If test is non-NULL, it searches for an
existing superblock matching the criteria held in the fs_context, using
@@ -482,10 +562,12 @@
The following helpers all wrap sget_fc():
- (*) int vfs_get_super(struct fs_context *fc,
- enum vfs_get_super_keying keying,
- int (*fill_super)(struct super_block *sb,
- struct fs_context *fc))
+ * ::
+
+ int vfs_get_super(struct fs_context *fc,
+ enum vfs_get_super_keying keying,
+ int (*fill_super)(struct super_block *sb,
+ struct fs_context *fc))
This creates/looks up a deviceless superblock. The keying indicates how
many superblocks of this type may exist and in what manner they may be
@@ -515,14 +597,14 @@
=====================
Parameters are described using structures defined in linux/fs_parser.h.
-There's a core description struct that links everything together:
+There's a core description struct that links everything together::
struct fs_parameter_description {
const struct fs_parameter_spec *specs;
const struct fs_parameter_enum *enums;
};
-For example:
+For example::
enum {
Opt_autocell,
@@ -539,10 +621,12 @@
The members are as follows:
- (1) const struct fs_parameter_specification *specs;
+ (1) ::
+
+ const struct fs_parameter_specification *specs;
Table of parameter specifications, terminated with a null entry, where the
- entries are of type:
+ entries are of type::
struct fs_parameter_spec {
const char *name;
@@ -558,6 +642,7 @@
The 'type' field indicates the desired value type and must be one of:
+ ======================= ======================= =====================
TYPE NAME EXPECTED VALUE RESULT IN
======================= ======================= =====================
fs_param_is_flag No value n/a
@@ -573,19 +658,23 @@
fs_param_is_blockdev Blockdev path * Needs lookup
fs_param_is_path Path * Needs lookup
fs_param_is_fd File descriptor result->int_32
+ ======================= ======================= =====================
Note that if the value is of fs_param_is_bool type, fs_parse() will try
to match any string value against "0", "1", "no", "yes", "false", "true".
Each parameter can also be qualified with 'flags':
+ ======================= ================================================
fs_param_v_optional The value is optional
fs_param_neg_with_no result->negated set if key is prefixed with "no"
fs_param_neg_with_empty result->negated set if value is ""
fs_param_deprecated The parameter is deprecated.
+ ======================= ================================================
These are wrapped with a number of convenience wrappers:
+ ======================= ===============================================
MACRO SPECIFIES
======================= ===============================================
fsparam_flag() fs_param_is_flag
@@ -602,9 +691,10 @@
fsparam_bdev() fs_param_is_blockdev
fsparam_path() fs_param_is_path
fsparam_fd() fs_param_is_fd
+ ======================= ===============================================
all of which take two arguments, name string and option number - for
- example:
+ example::
static const struct fs_parameter_spec afs_param_specs[] = {
fsparam_flag ("autocell", Opt_autocell),
@@ -618,10 +708,12 @@
of arguments to specify the type and the flags for anything that doesn't
match one of the above macros.
- (2) const struct fs_parameter_enum *enums;
+ (2) ::
+
+ const struct fs_parameter_enum *enums;
Table of enum value names to integer mappings, terminated with a null
- entry. This is of type:
+ entry. This is of type::
struct fs_parameter_enum {
u8 opt;
@@ -630,7 +722,7 @@
};
Where the array is an unsorted list of { parameter ID, name }-keyed
- elements that indicate the value to map to, e.g.:
+ elements that indicate the value to map to, e.g.::
static const struct fs_parameter_enum afs_param_enums[] = {
{ Opt_bar, "x", 1},
@@ -648,18 +740,19 @@
userspace using the fsinfo() syscall.
-==========================
-PARAMETER HELPER FUNCTIONS
+Parameter Helper Functions
==========================
A number of helper functions are provided to help a filesystem or an LSM
process the parameters it is given.
- (*) int lookup_constant(const struct constant_table tbl[],
- const char *name, int not_found);
+ * ::
+
+ int lookup_constant(const struct constant_table tbl[],
+ const char *name, int not_found);
Look up a constant by name in a table of name -> integer mappings. The
- table is an array of elements of the following type:
+ table is an array of elements of the following type::
struct constant_table {
const char *name;
@@ -669,9 +762,11 @@
If a match is found, the corresponding value is returned. If a match
isn't found, the not_found value is returned instead.
- (*) bool validate_constant_table(const struct constant_table *tbl,
- size_t tbl_size,
- int low, int high, int special);
+ * ::
+
+ bool validate_constant_table(const struct constant_table *tbl,
+ size_t tbl_size,
+ int low, int high, int special);
Validate a constant table. Checks that all the elements are appropriately
ordered, that there are no duplicates and that the values are between low
@@ -682,16 +777,20 @@
If all is good, true is returned. If the table is invalid, errors are
logged to dmesg and false is returned.
- (*) bool fs_validate_description(const struct fs_parameter_description *desc);
+ * ::
+
+ bool fs_validate_description(const struct fs_parameter_description *desc);
This performs some validation checks on a parameter description. It
returns true if the description is good and false if it is not. It will
log errors to dmesg if validation fails.
- (*) int fs_parse(struct fs_context *fc,
- const struct fs_parameter_description *desc,
- struct fs_parameter *param,
- struct fs_parse_result *result);
+ * ::
+
+ int fs_parse(struct fs_context *fc,
+ const struct fs_parameter_description *desc,
+ struct fs_parameter *param,
+ struct fs_parse_result *result);
This is the main interpreter of parameters. It uses the parameter
description to look up a parameter by key name and to convert that to an
@@ -711,14 +810,16 @@
parameter is matched, but the value is erroneous, -EINVAL will be
returned; otherwise the parameter's option number will be returned.
- (*) int fs_lookup_param(struct fs_context *fc,
- struct fs_parameter *value,
- bool want_bdev,
- struct path *_path);
+ * ::
+
+ int fs_lookup_param(struct fs_context *fc,
+ struct fs_parameter *value,
+ bool want_bdev,
+ struct path *_path);
This takes a parameter that carries a string or filename type and attempts
to do a path lookup on it. If the parameter expects a blockdev, a check
is made that the inode actually represents one.
- Returns 0 if successful and *_path will be set; returns a negative error
- code if not.
+ Returns 0 if successful and ``*_path`` will be set; returns a negative
+ error code if not.
diff --git a/Documentation/filesystems/orangefs.rst b/Documentation/filesystems/orangefs.rst
index e413697..463e376 100644
--- a/Documentation/filesystems/orangefs.rst
+++ b/Documentation/filesystems/orangefs.rst
@@ -119,9 +119,7 @@
/opt/ofs/bin/pvfs2-genconfig /etc/pvfs2.conf
-Create an /etc/pvfs2tab file::
-
-Localhost is fine for your pvfs2tab file:
+Create an /etc/pvfs2tab file (localhost is fine)::
echo tcp://localhost:3334/orangefs /pvfsmnt pvfs2 defaults,noauto 0 0 > \
/etc/pvfs2tab
diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
index 9969bf4..06d41c0 100644
--- a/Documentation/filesystems/proc.rst
+++ b/Documentation/filesystems/proc.rst
@@ -1871,7 +1871,7 @@
For more information on mount propagation see:
- Documentation/filesystems/sharedsubtree.txt
+ Documentation/filesystems/sharedsubtree.rst
3.6 /proc/<pid>/comm & /proc/<pid>/task/<tid>/comm
diff --git a/Documentation/filesystems/quota.txt b/Documentation/filesystems/quota.rst
similarity index 80%
rename from Documentation/filesystems/quota.txt
rename to Documentation/filesystems/quota.rst
index 32874b0..a30cdd4 100644
--- a/Documentation/filesystems/quota.txt
+++ b/Documentation/filesystems/quota.rst
@@ -1,4 +1,6 @@
+.. SPDX-License-Identifier: GPL-2.0
+===============
Quota subsystem
===============
@@ -39,6 +41,7 @@
This command is used to send a notification about any of the above mentioned
events. Each message has six attributes. These are (type of the argument is
in parentheses):
+
QUOTA_NL_A_QTYPE (u32)
- type of quota being exceeded (one of USRQUOTA, GRPQUOTA)
QUOTA_NL_A_EXCESS_ID (u64)
@@ -48,20 +51,34 @@
- UID of a user who caused the event
QUOTA_NL_A_WARNING (u32)
- what kind of limit is exceeded:
- QUOTA_NL_IHARDWARN - inode hardlimit
- QUOTA_NL_ISOFTLONGWARN - inode softlimit is exceeded longer
- than given grace period
- QUOTA_NL_ISOFTWARN - inode softlimit
- QUOTA_NL_BHARDWARN - space (block) hardlimit
- QUOTA_NL_BSOFTLONGWARN - space (block) softlimit is exceeded
- longer than given grace period.
- QUOTA_NL_BSOFTWARN - space (block) softlimit
+
+ QUOTA_NL_IHARDWARN
+ inode hardlimit
+ QUOTA_NL_ISOFTLONGWARN
+ inode softlimit is exceeded longer
+ than given grace period
+ QUOTA_NL_ISOFTWARN
+ inode softlimit
+ QUOTA_NL_BHARDWARN
+ space (block) hardlimit
+ QUOTA_NL_BSOFTLONGWARN
+ space (block) softlimit is exceeded
+ longer than given grace period.
+ QUOTA_NL_BSOFTWARN
+ space (block) softlimit
+
- four warnings are also defined for the event when user stops
exceeding some limit:
- QUOTA_NL_IHARDBELOW - inode hardlimit
- QUOTA_NL_ISOFTBELOW - inode softlimit
- QUOTA_NL_BHARDBELOW - space (block) hardlimit
- QUOTA_NL_BSOFTBELOW - space (block) softlimit
+
+ QUOTA_NL_IHARDBELOW
+ inode hardlimit
+ QUOTA_NL_ISOFTBELOW
+ inode softlimit
+ QUOTA_NL_BHARDBELOW
+ space (block) hardlimit
+ QUOTA_NL_BSOFTBELOW
+ space (block) softlimit
+
QUOTA_NL_A_DEV_MAJOR (u32)
- major number of a device with the affected filesystem
QUOTA_NL_A_DEV_MINOR (u32)
diff --git a/Documentation/filesystems/ramfs-rootfs-initramfs.rst b/Documentation/filesystems/ramfs-rootfs-initramfs.rst
index 6c576e2..3fddacc 100644
--- a/Documentation/filesystems/ramfs-rootfs-initramfs.rst
+++ b/Documentation/filesystems/ramfs-rootfs-initramfs.rst
@@ -71,7 +71,7 @@
A ramfs derivative called tmpfs was created to add size limits, and the ability
to write the data to swap space. Normal users can be allowed write access to
-tmpfs mounts. See Documentation/filesystems/tmpfs.txt for more information.
+tmpfs mounts. See Documentation/filesystems/tmpfs.rst for more information.
What is rootfs?
---------------
diff --git a/Documentation/filesystems/seq_file.txt b/Documentation/filesystems/seq_file.rst
similarity index 91%
rename from Documentation/filesystems/seq_file.txt
rename to Documentation/filesystems/seq_file.rst
index d412b23..fab3020 100644
--- a/Documentation/filesystems/seq_file.txt
+++ b/Documentation/filesystems/seq_file.rst
@@ -1,6 +1,11 @@
-The seq_file interface
+.. SPDX-License-Identifier: GPL-2.0
+
+======================
+The seq_file Interface
+======================
Copyright 2003 Jonathan Corbet <corbet@lwn.net>
+
This file is originally from the LWN.net Driver Porting series at
http://lwn.net/Articles/driver-porting/
@@ -43,7 +48,7 @@
read, simply produces a set of increasing integer values, one per line. The
sequence will continue until the user loses patience and finds something
better to do. The file is seekable, in that one can do something like the
-following:
+following::
dd if=/proc/sequence of=out1 count=1
dd if=/proc/sequence skip=1 of=out2 count=1
@@ -55,16 +60,18 @@
http://lwn.net/Articles/22359/).
Deprecated create_proc_entry
+============================
Note that the above article uses create_proc_entry which was removed in
-kernel 3.10. Current versions require the following update
+kernel 3.10. Current versions require the following update::
-- entry = create_proc_entry("sequence", 0, NULL);
-- if (entry)
-- entry->proc_fops = &ct_file_ops;
-+ entry = proc_create("sequence", 0, NULL, &ct_file_ops);
+ - entry = create_proc_entry("sequence", 0, NULL);
+ - if (entry)
+ - entry->proc_fops = &ct_file_ops;
+ + entry = proc_create("sequence", 0, NULL, &ct_file_ops);
The iterator interface
+======================
Modules implementing a virtual file with seq_file must implement an
iterator object that allows stepping through the data of interest
@@ -99,7 +106,7 @@
the most recent pos used in the previous session.
For our simple sequence example,
-the start() function looks like:
+the start() function looks like::
static void *ct_seq_start(struct seq_file *s, loff_t *pos)
{
@@ -129,7 +136,7 @@
example module can simply increment the position by one; more useful
modules will do what is needed to step through some data structure. The
next() function returns a new iterator, or NULL if the sequence is
-complete. Here's the example version:
+complete. Here's the example version::
static void *ct_seq_next(struct seq_file *s, void *v, loff_t *pos)
{
@@ -141,10 +148,10 @@
The stop() function closes a session; its job, of course, is to clean
up. If dynamic memory is allocated for the iterator, stop() is the
place to free it; if a lock was taken by start(), stop() must release
-that lock. The value that *pos was set to by the last next() call
+that lock. The value that ``*pos`` was set to by the last next() call
before stop() is remembered, and used for the first start() call of
the next session unless lseek() has been called on the file; in that
-case next start() will be asked to start at position zero.
+case next start() will be asked to start at position zero::
static void ct_seq_stop(struct seq_file *s, void *v)
{
@@ -152,7 +159,7 @@
}
Finally, the show() function should format the object currently pointed to
-by the iterator for output. The example module's show() function is:
+by the iterator for output. The example module's show() function is::
static int ct_seq_show(struct seq_file *s, void *v)
{
@@ -169,7 +176,7 @@
We will look at seq_printf() in a moment. But first, the definition of the
seq_file iterator is finished by creating a seq_operations structure with
-the four functions we have just defined:
+the four functions we have just defined::
static const struct seq_operations ct_seq_ops = {
.start = ct_seq_start,
@@ -194,6 +201,7 @@
Formatted output
+================
The seq_file code manages positioning within the output created by the
iterator and getting it into the user's buffer. But, for that to work, that
@@ -203,7 +211,7 @@
Most code will simply use seq_printf(), which works pretty much like
printk(), but which requires the seq_file pointer as an argument.
-For straight character output, the following functions may be used:
+For straight character output, the following functions may be used::
seq_putc(struct seq_file *m, char c);
seq_puts(struct seq_file *m, const char *s);
@@ -213,7 +221,7 @@
expect. seq_escape() is like seq_puts(), except that any character in s
which is in the string esc will be represented in octal form in the output.
-There are also a pair of functions for printing filenames:
+There are also a pair of functions for printing filenames::
int seq_path(struct seq_file *m, const struct path *path,
const char *esc);
@@ -226,8 +234,10 @@
root is desired, it can be used with seq_path_root(). If it turns out that
path cannot be reached from root, seq_path_root() returns SEQ_SKIP.
-A function producing complicated output may want to check
+A function producing complicated output may want to check::
+
bool seq_has_overflowed(struct seq_file *m);
+
and avoid further seq_<output> calls if true is returned.
A true return from seq_has_overflowed means that the seq_file buffer will
@@ -236,6 +246,7 @@
Making it all work
+==================
So far, we have a nice set of functions which can produce output within the
seq_file system, but we have not yet turned them into a file that a user
@@ -244,7 +255,7 @@
file. The seq_file interface provides a set of canned operations which do
most of the work. The virtual file author still must implement the open()
method, however, to hook everything up. The open function is often a single
-line, as in the example module:
+line, as in the example module::
static int ct_open(struct inode *inode, struct file *file)
{
@@ -263,7 +274,7 @@
There is also a wrapper function to seq_open() called seq_open_private(). It
kmallocs a zero filled block of memory and stores a pointer to it in the
private field of the seq_file structure, returning 0 on success. The
-block size is specified in a third parameter to the function, e.g.:
+block size is specified in a third parameter to the function, e.g.::
static int ct_open(struct inode *inode, struct file *file)
{
@@ -273,7 +284,7 @@
There is also a variant function, __seq_open_private(), which is functionally
identical except that, if successful, it returns the pointer to the allocated
-memory block, allowing further initialisation e.g.:
+memory block, allowing further initialisation e.g.::
static int ct_open(struct inode *inode, struct file *file)
{
@@ -295,7 +306,7 @@
The other operations of interest - read(), llseek(), and release() - are
all implemented by the seq_file code itself. So a virtual file's
-file_operations structure will look like:
+file_operations structure will look like::
static const struct file_operations ct_file_ops = {
.owner = THIS_MODULE,
@@ -309,7 +320,7 @@
seq_file private field to kfree() before releasing the structure.
The final step is the creation of the /proc file itself. In the example
-code, that is done in the initialization code in the usual way:
+code, that is done in the initialization code in the usual way::
static int ct_init(void)
{
@@ -325,9 +336,10 @@
seq_list
+========
If your file will be iterating through a linked list, you may find these
-routines useful:
+routines useful::
struct list_head *seq_list_start(struct list_head *head,
loff_t pos);
@@ -338,15 +350,16 @@
These helpers will interpret pos as a position within the list and iterate
accordingly. Your start() and next() functions need only invoke the
-seq_list_* helpers with a pointer to the appropriate list_head structure.
+``seq_list_*`` helpers with a pointer to the appropriate list_head structure.
The extra-simple version
+========================
For extremely simple virtual files, there is an even easier interface. A
module can define only the show() function, which should create all the
output that the virtual file will contain. The file's open() method then
-calls:
+calls::
int single_open(struct file *file,
int (*show)(struct seq_file *m, void *p),
diff --git a/Documentation/filesystems/sharedsubtree.txt b/Documentation/filesystems/sharedsubtree.rst
similarity index 72%
rename from Documentation/filesystems/sharedsubtree.txt
rename to Documentation/filesystems/sharedsubtree.rst
index 8ccfbd5..d833953 100644
--- a/Documentation/filesystems/sharedsubtree.txt
+++ b/Documentation/filesystems/sharedsubtree.rst
@@ -1,7 +1,10 @@
-Shared Subtrees
----------------
+.. SPDX-License-Identifier: GPL-2.0
-Contents:
+===============
+Shared Subtrees
+===============
+
+.. Contents:
1) Overview
2) Features
3) Setting mount states
@@ -41,31 +44,38 @@
Here is an example:
- Let's say /mnt has a mount that is shared.
- mount --make-shared /mnt
+ Let's say /mnt has a mount that is shared::
+
+ mount --make-shared /mnt
Note: mount(8) command now supports the --make-shared flag,
so the sample 'smount' program is no longer needed and has been
removed.
- # mount --bind /mnt /tmp
+ ::
+
+ # mount --bind /mnt /tmp
+
The above command replicates the mount at /mnt to the mountpoint /tmp
and the contents of both the mounts remain identical.
- #ls /mnt
- a b c
+ ::
- #ls /tmp
- a b c
+ #ls /mnt
+ a b c
- Now let's say we mount a device at /tmp/a
- # mount /dev/sd0 /tmp/a
+ #ls /tmp
+ a b c
- #ls /tmp/a
- t1 t2 t3
+ Now let's say we mount a device at /tmp/a::
- #ls /mnt/a
- t1 t2 t3
+ # mount /dev/sd0 /tmp/a
+
+ #ls /tmp/a
+ t1 t2 t3
+
+ #ls /mnt/a
+ t1 t2 t3
Note that the mount has propagated to the mount at /mnt as well.
@@ -123,14 +133,15 @@
2d) A unbindable mount is a unbindable private mount
- let's say we have a mount at /mnt and we make it unbindable
+ let's say we have a mount at /mnt and we make it unbindable::
- # mount --make-unbindable /mnt
+ # mount --make-unbindable /mnt
- Let's try to bind mount this mount somewhere else.
- # mount --bind /mnt /tmp
- mount: wrong fs type, bad option, bad superblock on /mnt,
- or too many mounted file systems
+ Let's try to bind mount this mount somewhere else::
+
+ # mount --bind /mnt /tmp
+ mount: wrong fs type, bad option, bad superblock on /mnt,
+ or too many mounted file systems
Binding a unbindable mount is a invalid operation.
@@ -138,12 +149,12 @@
3) Setting mount states
The mount command (util-linux package) can be used to set mount
- states:
+ states::
- mount --make-shared mountpoint
- mount --make-slave mountpoint
- mount --make-private mountpoint
- mount --make-unbindable mountpoint
+ mount --make-shared mountpoint
+ mount --make-slave mountpoint
+ mount --make-private mountpoint
+ mount --make-unbindable mountpoint
4) Use cases
@@ -154,9 +165,10 @@
Solution:
- The system administrator can make the mount at /cdrom shared
- mount --bind /cdrom /cdrom
- mount --make-shared /cdrom
+ The system administrator can make the mount at /cdrom shared::
+
+ mount --bind /cdrom /cdrom
+ mount --make-shared /cdrom
Now any process that clones off a new namespace will have a
mount at /cdrom which is a replica of the same mount in the
@@ -172,14 +184,14 @@
Solution:
To begin with, the administrator can mark the entire mount tree
- as shareable.
+ as shareable::
- mount --make-rshared /
+ mount --make-rshared /
A new process can clone off a new namespace. And mark some part
- of its namespace as slave
+ of its namespace as slave::
- mount --make-rslave /myprivatetree
+ mount --make-rslave /myprivatetree
Hence forth any mounts within the /myprivatetree done by the
process will not show up in any other namespace. However mounts
@@ -206,13 +218,13 @@
versions of the file depending on the path used to access that
file.
- An example is:
+ An example is::
- mount --make-shared /
- mount --rbind / /view/v1
- mount --rbind / /view/v2
- mount --rbind / /view/v3
- mount --rbind / /view/v4
+ mount --make-shared /
+ mount --rbind / /view/v1
+ mount --rbind / /view/v2
+ mount --rbind / /view/v3
+ mount --rbind / /view/v4
and if /usr has a versioning filesystem mounted, then that
mount appears at /view/v1/usr, /view/v2/usr, /view/v3/usr and
@@ -224,8 +236,8 @@
filesystem is being requested and return the corresponding
inode.
-5) Detailed semantics:
--------------------
+5) Detailed semantics
+---------------------
The section below explains the detailed semantics of
bind, rbind, move, mount, umount and clone-namespace operations.
@@ -235,6 +247,7 @@
5a) Mount states
A given mount can be in one of the following states
+
1) shared
2) slave
3) shared and slave
@@ -252,7 +265,8 @@
A 'shared mount' is defined as a vfsmount that belongs to a
'peer group'.
- For example:
+ For example::
+
mount --make-shared /mnt
mount --bind /mnt /tmp
@@ -270,7 +284,7 @@
A slave mount as the name implies has a master mount from which
mount/unmount events are received. Events do not propagate from
the slave mount to the master. Only a shared mount can be made
- a slave by executing the following command
+ a slave by executing the following command::
mount --make-slave mount
@@ -290,8 +304,10 @@
peer group.
Only a slave vfsmount can be made as 'shared and slave' by
- either executing the following command
+ either executing the following command::
+
mount --make-shared mount
+
or by moving the slave vfsmount under a shared vfsmount.
(4) Private mount
@@ -307,30 +323,32 @@
State diagram:
+
The state diagram below explains the state transition of a mount,
- in response to various commands.
- ------------------------------------------------------------------------
- | |make-shared | make-slave | make-private |make-unbindab|
- --------------|------------|--------------|--------------|-------------|
- |shared |shared |*slave/private| private | unbindable |
- | | | | | |
- |-------------|------------|--------------|--------------|-------------|
- |slave |shared | **slave | private | unbindable |
- | |and slave | | | |
- |-------------|------------|--------------|--------------|-------------|
- |shared |shared | slave | private | unbindable |
- |and slave |and slave | | | |
- |-------------|------------|--------------|--------------|-------------|
- |private |shared | **private | private | unbindable |
- |-------------|------------|--------------|--------------|-------------|
- |unbindable |shared |**unbindable | private | unbindable |
- ------------------------------------------------------------------------
+ in response to various commands::
- * if the shared mount is the only mount in its peer group, making it
- slave, makes it private automatically. Note that there is no master to
- which it can be slaved to.
+ -----------------------------------------------------------------------
+ | |make-shared | make-slave | make-private |make-unbindab|
+ --------------|------------|--------------|--------------|-------------|
+ |shared |shared |*slave/private| private | unbindable |
+ | | | | | |
+ |-------------|------------|--------------|--------------|-------------|
+ |slave |shared | **slave | private | unbindable |
+ | |and slave | | | |
+ |-------------|------------|--------------|--------------|-------------|
+ |shared |shared | slave | private | unbindable |
+ |and slave |and slave | | | |
+ |-------------|------------|--------------|--------------|-------------|
+ |private |shared | **private | private | unbindable |
+ |-------------|------------|--------------|--------------|-------------|
+ |unbindable |shared |**unbindable | private | unbindable |
+ ------------------------------------------------------------------------
- ** slaving a non-shared mount has no effect on the mount.
+ * if the shared mount is the only mount in its peer group, making it
+ slave, makes it private automatically. Note that there is no master to
+ which it can be slaved to.
+
+ ** slaving a non-shared mount has no effect on the mount.
Apart from the commands listed below, the 'move' operation also changes
the state of a mount depending on type of the destination mount. Its
@@ -338,31 +356,32 @@
5b) Bind semantics
- Consider the following command
+ Consider the following command::
- mount --bind A/a B/b
+ mount --bind A/a B/b
where 'A' is the source mount, 'a' is the dentry in the mount 'A', 'B'
is the destination mount and 'b' is the dentry in the destination mount.
The outcome depends on the type of mount of 'A' and 'B'. The table
- below contains quick reference.
- ---------------------------------------------------------------------------
- | BIND MOUNT OPERATION |
- |**************************************************************************
- |source(A)->| shared | private | slave | unbindable |
- | dest(B) | | | | |
- | | | | | | |
- | v | | | | |
- |**************************************************************************
- | shared | shared | shared | shared & slave | invalid |
- | | | | | |
- |non-shared| shared | private | slave | invalid |
- ***************************************************************************
+ below contains quick reference::
+
+ --------------------------------------------------------------------------
+ | BIND MOUNT OPERATION |
+ |************************************************************************|
+ |source(A)->| shared | private | slave | unbindable |
+ | dest(B) | | | | |
+ | | | | | | |
+ | v | | | | |
+ |************************************************************************|
+ | shared | shared | shared | shared & slave | invalid |
+ | | | | | |
+ |non-shared| shared | private | slave | invalid |
+ **************************************************************************
Details:
- 1. 'A' is a shared mount and 'B' is a shared mount. A new mount 'C'
+ 1. 'A' is a shared mount and 'B' is a shared mount. A new mount 'C'
which is clone of 'A', is created. Its root dentry is 'a' . 'C' is
mounted on mount 'B' at dentry 'b'. Also new mount 'C1', 'C2', 'C3' ...
are created and mounted at the dentry 'b' on all mounts where 'B'
@@ -371,7 +390,7 @@
'B'. And finally the peer-group of 'C' is merged with the peer group
of 'A'.
- 2. 'A' is a private mount and 'B' is a shared mount. A new mount 'C'
+ 2. 'A' is a private mount and 'B' is a shared mount. A new mount 'C'
which is clone of 'A', is created. Its root dentry is 'a'. 'C' is
mounted on mount 'B' at dentry 'b'. Also new mount 'C1', 'C2', 'C3' ...
are created and mounted at the dentry 'b' on all mounts where 'B'
@@ -379,7 +398,7 @@
'C', 'C1', .., 'Cn' with exactly the same configuration as the
propagation tree for 'B'.
- 3. 'A' is a slave mount of mount 'Z' and 'B' is a shared mount. A new
+ 3. 'A' is a slave mount of mount 'Z' and 'B' is a shared mount. A new
mount 'C' which is clone of 'A', is created. Its root dentry is 'a' .
'C' is mounted on mount 'B' at dentry 'b'. Also new mounts 'C1', 'C2',
'C3' ... are created and mounted at the dentry 'b' on all mounts where
@@ -389,19 +408,19 @@
is made the slave of mount 'Z'. In other words, mount 'C' is in the
state 'slave and shared'.
- 4. 'A' is a unbindable mount and 'B' is a shared mount. This is a
+ 4. 'A' is a unbindable mount and 'B' is a shared mount. This is a
invalid operation.
- 5. 'A' is a private mount and 'B' is a non-shared(private or slave or
+ 5. 'A' is a private mount and 'B' is a non-shared(private or slave or
unbindable) mount. A new mount 'C' which is clone of 'A', is created.
Its root dentry is 'a'. 'C' is mounted on mount 'B' at dentry 'b'.
- 6. 'A' is a shared mount and 'B' is a non-shared mount. A new mount 'C'
+ 6. 'A' is a shared mount and 'B' is a non-shared mount. A new mount 'C'
which is a clone of 'A' is created. Its root dentry is 'a'. 'C' is
mounted on mount 'B' at dentry 'b'. 'C' is made a member of the
peer-group of 'A'.
- 7. 'A' is a slave mount of mount 'Z' and 'B' is a non-shared mount. A
+ 7. 'A' is a slave mount of mount 'Z' and 'B' is a non-shared mount. A
new mount 'C' which is a clone of 'A' is created. Its root dentry is
'a'. 'C' is mounted on mount 'B' at dentry 'b'. Also 'C' is set as a
slave mount of 'Z'. In other words 'A' and 'C' are both slave mounts of
@@ -409,7 +428,7 @@
mount/unmount on 'A' do not propagate anywhere else. Similarly
mount/unmount on 'C' do not propagate anywhere else.
- 8. 'A' is a unbindable mount and 'B' is a non-shared mount. This is a
+ 8. 'A' is a unbindable mount and 'B' is a non-shared mount. This is a
invalid operation. A unbindable mount cannot be bind mounted.
5c) Rbind semantics
@@ -422,7 +441,9 @@
then the subtree under the unbindable mount is pruned in the new
location.
- eg: let's say we have the following mount tree.
+ eg:
+
+ let's say we have the following mount tree::
A
/ \
@@ -430,12 +451,12 @@
/ \ / \
D E F G
- Let's say all the mount except the mount C in the tree are
- of a type other than unbindable.
+ Let's say all the mount except the mount C in the tree are
+ of a type other than unbindable.
- If this tree is rbound to say Z
+ If this tree is rbound to say Z
- We will have the following tree at the new location.
+ We will have the following tree at the new location::
Z
|
@@ -457,24 +478,26 @@
the dentry in the destination mount.
The outcome depends on the type of the mount of 'A' and 'B'. The table
- below is a quick reference.
- ---------------------------------------------------------------------------
- | MOVE MOUNT OPERATION |
- |**************************************************************************
- | source(A)->| shared | private | slave | unbindable |
- | dest(B) | | | | |
- | | | | | | |
- | v | | | | |
- |**************************************************************************
- | shared | shared | shared |shared and slave| invalid |
- | | | | | |
- |non-shared| shared | private | slave | unbindable |
- ***************************************************************************
- NOTE: moving a mount residing under a shared mount is invalid.
+ below is a quick reference::
+
+ ---------------------------------------------------------------------------
+ | MOVE MOUNT OPERATION |
+ |**************************************************************************
+ | source(A)->| shared | private | slave | unbindable |
+ | dest(B) | | | | |
+ | | | | | | |
+ | v | | | | |
+ |**************************************************************************
+ | shared | shared | shared |shared and slave| invalid |
+ | | | | | |
+ |non-shared| shared | private | slave | unbindable |
+ ***************************************************************************
+
+ .. Note:: moving a mount residing under a shared mount is invalid.
Details follow:
- 1. 'A' is a shared mount and 'B' is a shared mount. The mount 'A' is
+ 1. 'A' is a shared mount and 'B' is a shared mount. The mount 'A' is
mounted on mount 'B' at dentry 'b'. Also new mounts 'A1', 'A2'...'An'
are created and mounted at dentry 'b' on all mounts that receive
propagation from mount 'B'. A new propagation tree is created in the
@@ -483,7 +506,7 @@
propagation tree is appended to the already existing propagation tree
of 'A'.
- 2. 'A' is a private mount and 'B' is a shared mount. The mount 'A' is
+ 2. 'A' is a private mount and 'B' is a shared mount. The mount 'A' is
mounted on mount 'B' at dentry 'b'. Also new mount 'A1', 'A2'... 'An'
are created and mounted at dentry 'b' on all mounts that receive
propagation from mount 'B'. The mount 'A' becomes a shared mount and a
@@ -491,7 +514,7 @@
'B'. This new propagation tree contains all the new mounts 'A1',
'A2'... 'An'.
- 3. 'A' is a slave mount of mount 'Z' and 'B' is a shared mount. The
+ 3. 'A' is a slave mount of mount 'Z' and 'B' is a shared mount. The
mount 'A' is mounted on mount 'B' at dentry 'b'. Also new mounts 'A1',
'A2'... 'An' are created and mounted at dentry 'b' on all mounts that
receive propagation from mount 'B'. A new propagation tree is created
@@ -501,32 +524,32 @@
'A'. Mount 'A' continues to be the slave mount of 'Z' but it also
becomes 'shared'.
- 4. 'A' is a unbindable mount and 'B' is a shared mount. The operation
+ 4. 'A' is a unbindable mount and 'B' is a shared mount. The operation
is invalid. Because mounting anything on the shared mount 'B' can
create new mounts that get mounted on the mounts that receive
propagation from 'B'. And since the mount 'A' is unbindable, cloning
it to mount at other mountpoints is not possible.
- 5. 'A' is a private mount and 'B' is a non-shared(private or slave or
+ 5. 'A' is a private mount and 'B' is a non-shared(private or slave or
unbindable) mount. The mount 'A' is mounted on mount 'B' at dentry 'b'.
- 6. 'A' is a shared mount and 'B' is a non-shared mount. The mount 'A'
+ 6. 'A' is a shared mount and 'B' is a non-shared mount. The mount 'A'
is mounted on mount 'B' at dentry 'b'. Mount 'A' continues to be a
shared mount.
- 7. 'A' is a slave mount of mount 'Z' and 'B' is a non-shared mount.
+ 7. 'A' is a slave mount of mount 'Z' and 'B' is a non-shared mount.
The mount 'A' is mounted on mount 'B' at dentry 'b'. Mount 'A'
continues to be a slave mount of mount 'Z'.
- 8. 'A' is a unbindable mount and 'B' is a non-shared mount. The mount
+ 8. 'A' is a unbindable mount and 'B' is a non-shared mount. The mount
'A' is mounted on mount 'B' at dentry 'b'. Mount 'A' continues to be a
unbindable mount.
5e) Mount semantics
- Consider the following command
+ Consider the following command::
- mount device B/b
+ mount device B/b
'B' is the destination mount and 'b' is the dentry in the destination
mount.
@@ -537,9 +560,9 @@
5f) Unmount semantics
- Consider the following command
+ Consider the following command::
- umount A
+ umount A
where 'A' is a mount mounted on mount 'B' at dentry 'b'.
@@ -592,10 +615,12 @@
A. What is the result of the following command sequence?
- mount --bind /mnt /mnt
- mount --make-shared /mnt
- mount --bind /mnt /tmp
- mount --move /tmp /mnt/1
+ ::
+
+ mount --bind /mnt /mnt
+ mount --make-shared /mnt
+ mount --bind /mnt /tmp
+ mount --move /tmp /mnt/1
what should be the contents of /mnt /mnt/1 /mnt/1/1 should be?
Should they all be identical? or should /mnt and /mnt/1 be
@@ -604,23 +629,27 @@
B. What is the result of the following command sequence?
- mount --make-rshared /
- mkdir -p /v/1
- mount --rbind / /v/1
+ ::
+
+ mount --make-rshared /
+ mkdir -p /v/1
+ mount --rbind / /v/1
what should be the content of /v/1/v/1 be?
C. What is the result of the following command sequence?
- mount --bind /mnt /mnt
- mount --make-shared /mnt
- mkdir -p /mnt/1/2/3 /mnt/1/test
- mount --bind /mnt/1 /tmp
- mount --make-slave /mnt
- mount --make-shared /mnt
- mount --bind /mnt/1/2 /tmp1
- mount --make-slave /mnt
+ ::
+
+ mount --bind /mnt /mnt
+ mount --make-shared /mnt
+ mkdir -p /mnt/1/2/3 /mnt/1/test
+ mount --bind /mnt/1 /tmp
+ mount --make-slave /mnt
+ mount --make-shared /mnt
+ mount --bind /mnt/1/2 /tmp1
+ mount --make-slave /mnt
At this point we have the first mount at /tmp and
its root dentry is 1. Let's call this mount 'A'
@@ -668,7 +697,8 @@
step 1:
let's say the root tree has just two directories with
- one vfsmount.
+ one vfsmount::
+
root
/ \
tmp usr
@@ -676,14 +706,17 @@
And we want to replicate the tree at multiple
mountpoints under /root/tmp
- step2:
- mount --make-shared /root
+ step 2:
+ ::
- mkdir -p /tmp/m1
- mount --rbind /root /tmp/m1
+ mount --make-shared /root
- the new tree now looks like this:
+ mkdir -p /tmp/m1
+
+ mount --rbind /root /tmp/m1
+
+ the new tree now looks like this::
root
/ \
@@ -697,11 +730,13 @@
it has two vfsmounts
- step3:
+ step 3:
+ ::
+
mkdir -p /tmp/m2
mount --rbind /root /tmp/m2
- the new tree now looks like this:
+ the new tree now looks like this::
root
/ \
@@ -724,6 +759,7 @@
it has 6 vfsmounts
step 4:
+ ::
mkdir -p /tmp/m3
mount --rbind /root /tmp/m3
@@ -740,7 +776,8 @@
step 1:
let's say the root tree has just two directories with
- one vfsmount.
+ one vfsmount::
+
root
/ \
tmp usr
@@ -748,17 +785,20 @@
How do we set up the same tree at multiple locations under
/root/tmp
- step2:
- mount --bind /root/tmp /root/tmp
+ step 2:
+ ::
- mount --make-rshared /root
- mount --make-unbindable /root/tmp
- mkdir -p /tmp/m1
+ mount --bind /root/tmp /root/tmp
- mount --rbind /root /tmp/m1
+ mount --make-rshared /root
+ mount --make-unbindable /root/tmp
- the new tree now looks like this:
+ mkdir -p /tmp/m1
+
+ mount --rbind /root /tmp/m1
+
+ the new tree now looks like this::
root
/ \
@@ -768,11 +808,13 @@
/ \
tmp usr
- step3:
+ step 3:
+ ::
+
mkdir -p /tmp/m2
mount --rbind /root /tmp/m2
- the new tree now looks like this:
+ the new tree now looks like this::
root
/ \
@@ -782,12 +824,13 @@
/ \ / \
tmp usr tmp usr
- step4:
+ step 4:
+ ::
mkdir -p /tmp/m3
mount --rbind /root /tmp/m3
- the new tree now looks like this:
+ the new tree now looks like this::
root
/ \
@@ -801,25 +844,31 @@
8A) Datastructure
- 4 new fields are introduced to struct vfsmount
- ->mnt_share
- ->mnt_slave_list
- ->mnt_slave
- ->mnt_master
+ 4 new fields are introduced to struct vfsmount:
- ->mnt_share links together all the mount to/from which this vfsmount
+ * ->mnt_share
+ * ->mnt_slave_list
+ * ->mnt_slave
+ * ->mnt_master
+
+ ->mnt_share
+ links together all the mount to/from which this vfsmount
send/receives propagation events.
- ->mnt_slave_list links all the mounts to which this vfsmount propagates
+ ->mnt_slave_list
+ links all the mounts to which this vfsmount propagates
to.
- ->mnt_slave links together all the slaves that its master vfsmount
+ ->mnt_slave
+ links together all the slaves that its master vfsmount
propagates to.
- ->mnt_master points to the master vfsmount from which this vfsmount
+ ->mnt_master
+ points to the master vfsmount from which this vfsmount
receives propagation.
- ->mnt_flags takes two more flags to indicate the propagation status of
+ ->mnt_flags
+ takes two more flags to indicate the propagation status of
the vfsmount. MNT_SHARE indicates that the vfsmount is a shared
vfsmount. MNT_UNCLONABLE indicates that the vfsmount cannot be
replicated.
@@ -842,7 +891,7 @@
A example propagation tree looks as shown in the figure below.
[ NOTE: Though it looks like a forest, if we consider all the shared
- mounts as a conceptual entity called 'pnode', it becomes a tree]
+ mounts as a conceptual entity called 'pnode', it becomes a tree]::
A <--> B <--> C <---> D
@@ -864,14 +913,19 @@
A's ->mnt_slave_list links with ->mnt_slave of 'E', 'K', 'F' and 'G'
E's ->mnt_share links with ->mnt_share of K
- 'E', 'K', 'F', 'G' have their ->mnt_master point to struct
- vfsmount of 'A'
+
+ 'E', 'K', 'F', 'G' have their ->mnt_master point to struct vfsmount of 'A'
+
'M', 'L', 'N' have their ->mnt_master point to struct vfsmount of 'K'
+
K's ->mnt_slave_list links with ->mnt_slave of 'M', 'L' and 'N'
C's ->mnt_slave_list links with ->mnt_slave of 'J' and 'K'
+
J and K's ->mnt_master points to struct vfsmount of C
+
and finally D's ->mnt_slave_list links with ->mnt_slave of 'H' and 'I'
+
'H' and 'I' have their ->mnt_master pointing to struct vfsmount of 'D'.
@@ -903,6 +957,7 @@
Prepare phase:
for each mount in the source tree:
+
a) Create the necessary number of mount trees to
be attached to each of the mounts that receive
propagation from the destination mount.
@@ -929,11 +984,12 @@
Abort phase
delete all the newly created trees.
- NOTE: all the propagation related functionality resides in the file
- pnode.c
+ .. Note::
+ all the propagation related functionality resides in the file pnode.c
------------------------------------------------------------------------
version 0.1 (created the initial document, Ram Pai linuxram@us.ibm.com)
+
version 0.2 (Incorporated comments from Al Viro)
diff --git a/Documentation/filesystems/spufs.txt b/Documentation/filesystems/spufs.txt
deleted file mode 100644
index eb9e3aa..0000000
--- a/Documentation/filesystems/spufs.txt
+++ /dev/null
@@ -1,521 +0,0 @@
-SPUFS(2) Linux Programmer's Manual SPUFS(2)
-
-
-
-NAME
- spufs - the SPU file system
-
-
-DESCRIPTION
- The SPU file system is used on PowerPC machines that implement the Cell
- Broadband Engine Architecture in order to access Synergistic Processor
- Units (SPUs).
-
- The file system provides a name space similar to posix shared memory or
- message queues. Users that have write permissions on the file system
- can use spu_create(2) to establish SPU contexts in the spufs root.
-
- Every SPU context is represented by a directory containing a predefined
- set of files. These files can be used for manipulating the state of the
- logical SPU. Users can change permissions on those files, but not actu-
- ally add or remove files.
-
-
-MOUNT OPTIONS
- uid=<uid>
- set the user owning the mount point, the default is 0 (root).
-
- gid=<gid>
- set the group owning the mount point, the default is 0 (root).
-
-
-FILES
- The files in spufs mostly follow the standard behavior for regular sys-
- tem calls like read(2) or write(2), but often support only a subset of
- the operations supported on regular file systems. This list details the
- supported operations and the deviations from the behaviour in the
- respective man pages.
-
- All files that support the read(2) operation also support readv(2) and
- all files that support the write(2) operation also support writev(2).
- All files support the access(2) and stat(2) family of operations, but
- only the st_mode, st_nlink, st_uid and st_gid fields of struct stat
- contain reliable information.
-
- All files support the chmod(2)/fchmod(2) and chown(2)/fchown(2) opera-
- tions, but will not be able to grant permissions that contradict the
- possible operations, e.g. read access on the wbox file.
-
- The current set of files is:
-
-
- /mem
- the contents of the local storage memory of the SPU. This can be
- accessed like a regular shared memory file and contains both code and
- data in the address space of the SPU. The possible operations on an
- open mem file are:
-
- read(2), pread(2), write(2), pwrite(2), lseek(2)
- These operate as documented, with the exception that seek(2),
- write(2) and pwrite(2) are not supported beyond the end of the
- file. The file size is the size of the local storage of the SPU,
- which normally is 256 kilobytes.
-
- mmap(2)
- Mapping mem into the process address space gives access to the
- SPU local storage within the process address space. Only
- MAP_SHARED mappings are allowed.
-
-
- /mbox
- The first SPU to CPU communication mailbox. This file is read-only and
- can be read in units of 32 bits. The file can only be used in non-
- blocking mode and it even poll() will not block on it. The possible
- operations on an open mbox file are:
-
- read(2)
- If a count smaller than four is requested, read returns -1 and
- sets errno to EINVAL. If there is no data available in the mail
- box, the return value is set to -1 and errno becomes EAGAIN.
- When data has been read successfully, four bytes are placed in
- the data buffer and the value four is returned.
-
-
- /ibox
- The second SPU to CPU communication mailbox. This file is similar to
- the first mailbox file, but can be read in blocking I/O mode, and the
- poll family of system calls can be used to wait for it. The possible
- operations on an open ibox file are:
-
- read(2)
- If a count smaller than four is requested, read returns -1 and
- sets errno to EINVAL. If there is no data available in the mail
- box and the file descriptor has been opened with O_NONBLOCK, the
- return value is set to -1 and errno becomes EAGAIN.
-
- If there is no data available in the mail box and the file
- descriptor has been opened without O_NONBLOCK, the call will
- block until the SPU writes to its interrupt mailbox channel.
- When data has been read successfully, four bytes are placed in
- the data buffer and the value four is returned.
-
- poll(2)
- Poll on the ibox file returns (POLLIN | POLLRDNORM) whenever
- data is available for reading.
-
-
- /wbox
- The CPU to SPU communation mailbox. It is write-only and can be written
- in units of 32 bits. If the mailbox is full, write() will block and
- poll can be used to wait for it becoming empty again. The possible
- operations on an open wbox file are: write(2) If a count smaller than
- four is requested, write returns -1 and sets errno to EINVAL. If there
- is no space available in the mail box and the file descriptor has been
- opened with O_NONBLOCK, the return value is set to -1 and errno becomes
- EAGAIN.
-
- If there is no space available in the mail box and the file descriptor
- has been opened without O_NONBLOCK, the call will block until the SPU
- reads from its PPE mailbox channel. When data has been read success-
- fully, four bytes are placed in the data buffer and the value four is
- returned.
-
- poll(2)
- Poll on the ibox file returns (POLLOUT | POLLWRNORM) whenever
- space is available for writing.
-
-
- /mbox_stat
- /ibox_stat
- /wbox_stat
- Read-only files that contain the length of the current queue, i.e. how
- many words can be read from mbox or ibox or how many words can be
- written to wbox without blocking. The files can be read only in 4-byte
- units and return a big-endian binary integer number. The possible
- operations on an open *box_stat file are:
-
- read(2)
- If a count smaller than four is requested, read returns -1 and
- sets errno to EINVAL. Otherwise, a four byte value is placed in
- the data buffer, containing the number of elements that can be
- read from (for mbox_stat and ibox_stat) or written to (for
- wbox_stat) the respective mail box without blocking or resulting
- in EAGAIN.
-
-
- /npc
- /decr
- /decr_status
- /spu_tag_mask
- /event_mask
- /srr0
- Internal registers of the SPU. The representation is an ASCII string
- with the numeric value of the next instruction to be executed. These
- can be used in read/write mode for debugging, but normal operation of
- programs should not rely on them because access to any of them except
- npc requires an SPU context save and is therefore very inefficient.
-
- The contents of these files are:
-
- npc Next Program Counter
-
- decr SPU Decrementer
-
- decr_status Decrementer Status
-
- spu_tag_mask MFC tag mask for SPU DMA
-
- event_mask Event mask for SPU interrupts
-
- srr0 Interrupt Return address register
-
-
- The possible operations on an open npc, decr, decr_status,
- spu_tag_mask, event_mask or srr0 file are:
-
- read(2)
- When the count supplied to the read call is shorter than the
- required length for the pointer value plus a newline character,
- subsequent reads from the same file descriptor will result in
- completing the string, regardless of changes to the register by
- a running SPU task. When a complete string has been read, all
- subsequent read operations will return zero bytes and a new file
- descriptor needs to be opened to read the value again.
-
- write(2)
- A write operation on the file results in setting the register to
- the value given in the string. The string is parsed from the
- beginning to the first non-numeric character or the end of the
- buffer. Subsequent writes to the same file descriptor overwrite
- the previous setting.
-
-
- /fpcr
- This file gives access to the Floating Point Status and Control Regis-
- ter as a four byte long file. The operations on the fpcr file are:
-
- read(2)
- If a count smaller than four is requested, read returns -1 and
- sets errno to EINVAL. Otherwise, a four byte value is placed in
- the data buffer, containing the current value of the fpcr regis-
- ter.
-
- write(2)
- If a count smaller than four is requested, write returns -1 and
- sets errno to EINVAL. Otherwise, a four byte value is copied
- from the data buffer, updating the value of the fpcr register.
-
-
- /signal1
- /signal2
- The two signal notification channels of an SPU. These are read-write
- files that operate on a 32 bit word. Writing to one of these files
- triggers an interrupt on the SPU. The value written to the signal
- files can be read from the SPU through a channel read or from host user
- space through the file. After the value has been read by the SPU, it
- is reset to zero. The possible operations on an open signal1 or sig-
- nal2 file are:
-
- read(2)
- If a count smaller than four is requested, read returns -1 and
- sets errno to EINVAL. Otherwise, a four byte value is placed in
- the data buffer, containing the current value of the specified
- signal notification register.
-
- write(2)
- If a count smaller than four is requested, write returns -1 and
- sets errno to EINVAL. Otherwise, a four byte value is copied
- from the data buffer, updating the value of the specified signal
- notification register. The signal notification register will
- either be replaced with the input data or will be updated to the
- bitwise OR or the old value and the input data, depending on the
- contents of the signal1_type, or signal2_type respectively,
- file.
-
-
- /signal1_type
- /signal2_type
- These two files change the behavior of the signal1 and signal2 notifi-
- cation files. The contain a numerical ASCII string which is read as
- either "1" or "0". In mode 0 (overwrite), the hardware replaces the
- contents of the signal channel with the data that is written to it. in
- mode 1 (logical OR), the hardware accumulates the bits that are subse-
- quently written to it. The possible operations on an open signal1_type
- or signal2_type file are:
-
- read(2)
- When the count supplied to the read call is shorter than the
- required length for the digit plus a newline character, subse-
- quent reads from the same file descriptor will result in com-
- pleting the string. When a complete string has been read, all
- subsequent read operations will return zero bytes and a new file
- descriptor needs to be opened to read the value again.
-
- write(2)
- A write operation on the file results in setting the register to
- the value given in the string. The string is parsed from the
- beginning to the first non-numeric character or the end of the
- buffer. Subsequent writes to the same file descriptor overwrite
- the previous setting.
-
-
-EXAMPLES
- /etc/fstab entry
- none /spu spufs gid=spu 0 0
-
-
-AUTHORS
- Arnd Bergmann <arndb@de.ibm.com>, Mark Nutter <mnutter@us.ibm.com>,
- Ulrich Weigand <Ulrich.Weigand@de.ibm.com>
-
-SEE ALSO
- capabilities(7), close(2), spu_create(2), spu_run(2), spufs(7)
-
-
-
-Linux 2005-09-28 SPUFS(2)
-
-------------------------------------------------------------------------------
-
-SPU_RUN(2) Linux Programmer's Manual SPU_RUN(2)
-
-
-
-NAME
- spu_run - execute an spu context
-
-
-SYNOPSIS
- #include <sys/spu.h>
-
- int spu_run(int fd, unsigned int *npc, unsigned int *event);
-
-DESCRIPTION
- The spu_run system call is used on PowerPC machines that implement the
- Cell Broadband Engine Architecture in order to access Synergistic Pro-
- cessor Units (SPUs). It uses the fd that was returned from spu_cre-
- ate(2) to address a specific SPU context. When the context gets sched-
- uled to a physical SPU, it starts execution at the instruction pointer
- passed in npc.
-
- Execution of SPU code happens synchronously, meaning that spu_run does
- not return while the SPU is still running. If there is a need to exe-
- cute SPU code in parallel with other code on either the main CPU or
- other SPUs, you need to create a new thread of execution first, e.g.
- using the pthread_create(3) call.
-
- When spu_run returns, the current value of the SPU instruction pointer
- is written back to npc, so you can call spu_run again without updating
- the pointers.
-
- event can be a NULL pointer or point to an extended status code that
- gets filled when spu_run returns. It can be one of the following con-
- stants:
-
- SPE_EVENT_DMA_ALIGNMENT
- A DMA alignment error
-
- SPE_EVENT_SPE_DATA_SEGMENT
- A DMA segmentation error
-
- SPE_EVENT_SPE_DATA_STORAGE
- A DMA storage error
-
- If NULL is passed as the event argument, these errors will result in a
- signal delivered to the calling process.
-
-RETURN VALUE
- spu_run returns the value of the spu_status register or -1 to indicate
- an error and set errno to one of the error codes listed below. The
- spu_status register value contains a bit mask of status codes and
- optionally a 14 bit code returned from the stop-and-signal instruction
- on the SPU. The bit masks for the status codes are:
-
- 0x02 SPU was stopped by stop-and-signal.
-
- 0x04 SPU was stopped by halt.
-
- 0x08 SPU is waiting for a channel.
-
- 0x10 SPU is in single-step mode.
-
- 0x20 SPU has tried to execute an invalid instruction.
-
- 0x40 SPU has tried to access an invalid channel.
-
- 0x3fff0000
- The bits masked with this value contain the code returned from
- stop-and-signal.
-
- There are always one or more of the lower eight bits set or an error
- code is returned from spu_run.
-
-ERRORS
- EAGAIN or EWOULDBLOCK
- fd is in non-blocking mode and spu_run would block.
-
- EBADF fd is not a valid file descriptor.
-
- EFAULT npc is not a valid pointer or status is neither NULL nor a valid
- pointer.
-
- EINTR A signal occurred while spu_run was in progress. The npc value
- has been updated to the new program counter value if necessary.
-
- EINVAL fd is not a file descriptor returned from spu_create(2).
-
- ENOMEM Insufficient memory was available to handle a page fault result-
- ing from an MFC direct memory access.
-
- ENOSYS the functionality is not provided by the current system, because
- either the hardware does not provide SPUs or the spufs module is
- not loaded.
-
-
-NOTES
- spu_run is meant to be used from libraries that implement a more
- abstract interface to SPUs, not to be used from regular applications.
- See http://www.bsc.es/projects/deepcomputing/linuxoncell/ for the rec-
- ommended libraries.
-
-
-CONFORMING TO
- This call is Linux specific and only implemented by the ppc64 architec-
- ture. Programs using this system call are not portable.
-
-
-BUGS
- The code does not yet fully implement all features lined out here.
-
-
-AUTHOR
- Arnd Bergmann <arndb@de.ibm.com>
-
-SEE ALSO
- capabilities(7), close(2), spu_create(2), spufs(7)
-
-
-
-Linux 2005-09-28 SPU_RUN(2)
-
-------------------------------------------------------------------------------
-
-SPU_CREATE(2) Linux Programmer's Manual SPU_CREATE(2)
-
-
-
-NAME
- spu_create - create a new spu context
-
-
-SYNOPSIS
- #include <sys/types.h>
- #include <sys/spu.h>
-
- int spu_create(const char *pathname, int flags, mode_t mode);
-
-DESCRIPTION
- The spu_create system call is used on PowerPC machines that implement
- the Cell Broadband Engine Architecture in order to access Synergistic
- Processor Units (SPUs). It creates a new logical context for an SPU in
- pathname and returns a handle to associated with it. pathname must
- point to a non-existing directory in the mount point of the SPU file
- system (spufs). When spu_create is successful, a directory gets cre-
- ated on pathname and it is populated with files.
-
- The returned file handle can only be passed to spu_run(2) or closed,
- other operations are not defined on it. When it is closed, all associ-
- ated directory entries in spufs are removed. When the last file handle
- pointing either inside of the context directory or to this file
- descriptor is closed, the logical SPU context is destroyed.
-
- The parameter flags can be zero or any bitwise or'd combination of the
- following constants:
-
- SPU_RAWIO
- Allow mapping of some of the hardware registers of the SPU into
- user space. This flag requires the CAP_SYS_RAWIO capability, see
- capabilities(7).
-
- The mode parameter specifies the permissions used for creating the new
- directory in spufs. mode is modified with the user's umask(2) value
- and then used for both the directory and the files contained in it. The
- file permissions mask out some more bits of mode because they typically
- support only read or write access. See stat(2) for a full list of the
- possible mode values.
-
-
-RETURN VALUE
- spu_create returns a new file descriptor. It may return -1 to indicate
- an error condition and set errno to one of the error codes listed
- below.
-
-
-ERRORS
- EACCES
- The current user does not have write access on the spufs mount
- point.
-
- EEXIST An SPU context already exists at the given path name.
-
- EFAULT pathname is not a valid string pointer in the current address
- space.
-
- EINVAL pathname is not a directory in the spufs mount point.
-
- ELOOP Too many symlinks were found while resolving pathname.
-
- EMFILE The process has reached its maximum open file limit.
-
- ENAMETOOLONG
- pathname was too long.
-
- ENFILE The system has reached the global open file limit.
-
- ENOENT Part of pathname could not be resolved.
-
- ENOMEM The kernel could not allocate all resources required.
-
- ENOSPC There are not enough SPU resources available to create a new
- context or the user specific limit for the number of SPU con-
- texts has been reached.
-
- ENOSYS the functionality is not provided by the current system, because
- either the hardware does not provide SPUs or the spufs module is
- not loaded.
-
- ENOTDIR
- A part of pathname is not a directory.
-
-
-
-NOTES
- spu_create is meant to be used from libraries that implement a more
- abstract interface to SPUs, not to be used from regular applications.
- See http://www.bsc.es/projects/deepcomputing/linuxoncell/ for the rec-
- ommended libraries.
-
-
-FILES
- pathname must point to a location beneath the mount point of spufs. By
- convention, it gets mounted in /spu.
-
-
-CONFORMING TO
- This call is Linux specific and only implemented by the ppc64 architec-
- ture. Programs using this system call are not portable.
-
-
-BUGS
- The code does not yet fully implement all features lined out here.
-
-
-AUTHOR
- Arnd Bergmann <arndb@de.ibm.com>
-
-SEE ALSO
- capabilities(7), close(2), spu_run(2), spufs(7)
-
-
-
-Linux 2005-09-28 SPU_CREATE(2)
diff --git a/Documentation/filesystems/spufs/index.rst b/Documentation/filesystems/spufs/index.rst
new file mode 100644
index 0000000..5ed4a84
--- /dev/null
+++ b/Documentation/filesystems/spufs/index.rst
@@ -0,0 +1,13 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==============
+SPU Filesystem
+==============
+
+
+.. toctree::
+ :maxdepth: 1
+
+ spufs
+ spu_create
+ spu_run
diff --git a/Documentation/filesystems/spufs/spu_create.rst b/Documentation/filesystems/spufs/spu_create.rst
new file mode 100644
index 0000000..83108c0
--- /dev/null
+++ b/Documentation/filesystems/spufs/spu_create.rst
@@ -0,0 +1,131 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==========
+spu_create
+==========
+
+Name
+====
+ spu_create - create a new spu context
+
+
+Synopsis
+========
+
+ ::
+
+ #include <sys/types.h>
+ #include <sys/spu.h>
+
+ int spu_create(const char *pathname, int flags, mode_t mode);
+
+Description
+===========
+ The spu_create system call is used on PowerPC machines that implement
+ the Cell Broadband Engine Architecture in order to access Synergistic
+ Processor Units (SPUs). It creates a new logical context for an SPU in
+ pathname and returns a handle to associated with it. pathname must
+ point to a non-existing directory in the mount point of the SPU file
+ system (spufs). When spu_create is successful, a directory gets cre-
+ ated on pathname and it is populated with files.
+
+ The returned file handle can only be passed to spu_run(2) or closed,
+ other operations are not defined on it. When it is closed, all associ-
+ ated directory entries in spufs are removed. When the last file handle
+ pointing either inside of the context directory or to this file
+ descriptor is closed, the logical SPU context is destroyed.
+
+ The parameter flags can be zero or any bitwise or'd combination of the
+ following constants:
+
+ SPU_RAWIO
+ Allow mapping of some of the hardware registers of the SPU into
+ user space. This flag requires the CAP_SYS_RAWIO capability, see
+ capabilities(7).
+
+ The mode parameter specifies the permissions used for creating the new
+ directory in spufs. mode is modified with the user's umask(2) value
+ and then used for both the directory and the files contained in it. The
+ file permissions mask out some more bits of mode because they typically
+ support only read or write access. See stat(2) for a full list of the
+ possible mode values.
+
+
+Return Value
+============
+ spu_create returns a new file descriptor. It may return -1 to indicate
+ an error condition and set errno to one of the error codes listed
+ below.
+
+
+Errors
+======
+ EACCES
+ The current user does not have write access on the spufs mount
+ point.
+
+ EEXIST An SPU context already exists at the given path name.
+
+ EFAULT pathname is not a valid string pointer in the current address
+ space.
+
+ EINVAL pathname is not a directory in the spufs mount point.
+
+ ELOOP Too many symlinks were found while resolving pathname.
+
+ EMFILE The process has reached its maximum open file limit.
+
+ ENAMETOOLONG
+ pathname was too long.
+
+ ENFILE The system has reached the global open file limit.
+
+ ENOENT Part of pathname could not be resolved.
+
+ ENOMEM The kernel could not allocate all resources required.
+
+ ENOSPC There are not enough SPU resources available to create a new
+ context or the user specific limit for the number of SPU con-
+ texts has been reached.
+
+ ENOSYS the functionality is not provided by the current system, because
+ either the hardware does not provide SPUs or the spufs module is
+ not loaded.
+
+ ENOTDIR
+ A part of pathname is not a directory.
+
+
+
+Notes
+=====
+ spu_create is meant to be used from libraries that implement a more
+ abstract interface to SPUs, not to be used from regular applications.
+ See http://www.bsc.es/projects/deepcomputing/linuxoncell/ for the rec-
+ ommended libraries.
+
+
+Files
+=====
+ pathname must point to a location beneath the mount point of spufs. By
+ convention, it gets mounted in /spu.
+
+
+Conforming to
+=============
+ This call is Linux specific and only implemented by the ppc64 architec-
+ ture. Programs using this system call are not portable.
+
+
+Bugs
+====
+ The code does not yet fully implement all features lined out here.
+
+
+Author
+======
+ Arnd Bergmann <arndb@de.ibm.com>
+
+See Also
+========
+ capabilities(7), close(2), spu_run(2), spufs(7)
diff --git a/Documentation/filesystems/spufs/spu_run.rst b/Documentation/filesystems/spufs/spu_run.rst
new file mode 100644
index 0000000..7fdb1c3
--- /dev/null
+++ b/Documentation/filesystems/spufs/spu_run.rst
@@ -0,0 +1,138 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=======
+spu_run
+=======
+
+
+Name
+====
+ spu_run - execute an spu context
+
+
+Synopsis
+========
+
+ ::
+
+ #include <sys/spu.h>
+
+ int spu_run(int fd, unsigned int *npc, unsigned int *event);
+
+Description
+===========
+ The spu_run system call is used on PowerPC machines that implement the
+ Cell Broadband Engine Architecture in order to access Synergistic Pro-
+ cessor Units (SPUs). It uses the fd that was returned from spu_cre-
+ ate(2) to address a specific SPU context. When the context gets sched-
+ uled to a physical SPU, it starts execution at the instruction pointer
+ passed in npc.
+
+ Execution of SPU code happens synchronously, meaning that spu_run does
+ not return while the SPU is still running. If there is a need to exe-
+ cute SPU code in parallel with other code on either the main CPU or
+ other SPUs, you need to create a new thread of execution first, e.g.
+ using the pthread_create(3) call.
+
+ When spu_run returns, the current value of the SPU instruction pointer
+ is written back to npc, so you can call spu_run again without updating
+ the pointers.
+
+ event can be a NULL pointer or point to an extended status code that
+ gets filled when spu_run returns. It can be one of the following con-
+ stants:
+
+ SPE_EVENT_DMA_ALIGNMENT
+ A DMA alignment error
+
+ SPE_EVENT_SPE_DATA_SEGMENT
+ A DMA segmentation error
+
+ SPE_EVENT_SPE_DATA_STORAGE
+ A DMA storage error
+
+ If NULL is passed as the event argument, these errors will result in a
+ signal delivered to the calling process.
+
+Return Value
+============
+ spu_run returns the value of the spu_status register or -1 to indicate
+ an error and set errno to one of the error codes listed below. The
+ spu_status register value contains a bit mask of status codes and
+ optionally a 14 bit code returned from the stop-and-signal instruction
+ on the SPU. The bit masks for the status codes are:
+
+ 0x02
+ SPU was stopped by stop-and-signal.
+
+ 0x04
+ SPU was stopped by halt.
+
+ 0x08
+ SPU is waiting for a channel.
+
+ 0x10
+ SPU is in single-step mode.
+
+ 0x20
+ SPU has tried to execute an invalid instruction.
+
+ 0x40
+ SPU has tried to access an invalid channel.
+
+ 0x3fff0000
+ The bits masked with this value contain the code returned from
+ stop-and-signal.
+
+ There are always one or more of the lower eight bits set or an error
+ code is returned from spu_run.
+
+Errors
+======
+ EAGAIN or EWOULDBLOCK
+ fd is in non-blocking mode and spu_run would block.
+
+ EBADF fd is not a valid file descriptor.
+
+ EFAULT npc is not a valid pointer or status is neither NULL nor a valid
+ pointer.
+
+ EINTR A signal occurred while spu_run was in progress. The npc value
+ has been updated to the new program counter value if necessary.
+
+ EINVAL fd is not a file descriptor returned from spu_create(2).
+
+ ENOMEM Insufficient memory was available to handle a page fault result-
+ ing from an MFC direct memory access.
+
+ ENOSYS the functionality is not provided by the current system, because
+ either the hardware does not provide SPUs or the spufs module is
+ not loaded.
+
+
+Notes
+=====
+ spu_run is meant to be used from libraries that implement a more
+ abstract interface to SPUs, not to be used from regular applications.
+ See http://www.bsc.es/projects/deepcomputing/linuxoncell/ for the rec-
+ ommended libraries.
+
+
+Conforming to
+=============
+ This call is Linux specific and only implemented by the ppc64 architec-
+ ture. Programs using this system call are not portable.
+
+
+Bugs
+====
+ The code does not yet fully implement all features lined out here.
+
+
+Author
+======
+ Arnd Bergmann <arndb@de.ibm.com>
+
+See Also
+========
+ capabilities(7), close(2), spu_create(2), spufs(7)
diff --git a/Documentation/filesystems/spufs/spufs.rst b/Documentation/filesystems/spufs/spufs.rst
new file mode 100644
index 0000000..8a42859
--- /dev/null
+++ b/Documentation/filesystems/spufs/spufs.rst
@@ -0,0 +1,273 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=====
+spufs
+=====
+
+Name
+====
+
+ spufs - the SPU file system
+
+
+Description
+===========
+
+ The SPU file system is used on PowerPC machines that implement the Cell
+ Broadband Engine Architecture in order to access Synergistic Processor
+ Units (SPUs).
+
+ The file system provides a name space similar to posix shared memory or
+ message queues. Users that have write permissions on the file system
+ can use spu_create(2) to establish SPU contexts in the spufs root.
+
+ Every SPU context is represented by a directory containing a predefined
+ set of files. These files can be used for manipulating the state of the
+ logical SPU. Users can change permissions on those files, but not actu-
+ ally add or remove files.
+
+
+Mount Options
+=============
+
+ uid=<uid>
+ set the user owning the mount point, the default is 0 (root).
+
+ gid=<gid>
+ set the group owning the mount point, the default is 0 (root).
+
+
+Files
+=====
+
+ The files in spufs mostly follow the standard behavior for regular sys-
+ tem calls like read(2) or write(2), but often support only a subset of
+ the operations supported on regular file systems. This list details the
+ supported operations and the deviations from the behaviour in the
+ respective man pages.
+
+ All files that support the read(2) operation also support readv(2) and
+ all files that support the write(2) operation also support writev(2).
+ All files support the access(2) and stat(2) family of operations, but
+ only the st_mode, st_nlink, st_uid and st_gid fields of struct stat
+ contain reliable information.
+
+ All files support the chmod(2)/fchmod(2) and chown(2)/fchown(2) opera-
+ tions, but will not be able to grant permissions that contradict the
+ possible operations, e.g. read access on the wbox file.
+
+ The current set of files is:
+
+
+ /mem
+ the contents of the local storage memory of the SPU. This can be
+ accessed like a regular shared memory file and contains both code and
+ data in the address space of the SPU. The possible operations on an
+ open mem file are:
+
+ read(2), pread(2), write(2), pwrite(2), lseek(2)
+ These operate as documented, with the exception that seek(2),
+ write(2) and pwrite(2) are not supported beyond the end of the
+ file. The file size is the size of the local storage of the SPU,
+ which normally is 256 kilobytes.
+
+ mmap(2)
+ Mapping mem into the process address space gives access to the
+ SPU local storage within the process address space. Only
+ MAP_SHARED mappings are allowed.
+
+
+ /mbox
+ The first SPU to CPU communication mailbox. This file is read-only and
+ can be read in units of 32 bits. The file can only be used in non-
+ blocking mode and it even poll() will not block on it. The possible
+ operations on an open mbox file are:
+
+ read(2)
+ If a count smaller than four is requested, read returns -1 and
+ sets errno to EINVAL. If there is no data available in the mail
+ box, the return value is set to -1 and errno becomes EAGAIN.
+ When data has been read successfully, four bytes are placed in
+ the data buffer and the value four is returned.
+
+
+ /ibox
+ The second SPU to CPU communication mailbox. This file is similar to
+ the first mailbox file, but can be read in blocking I/O mode, and the
+ poll family of system calls can be used to wait for it. The possible
+ operations on an open ibox file are:
+
+ read(2)
+ If a count smaller than four is requested, read returns -1 and
+ sets errno to EINVAL. If there is no data available in the mail
+ box and the file descriptor has been opened with O_NONBLOCK, the
+ return value is set to -1 and errno becomes EAGAIN.
+
+ If there is no data available in the mail box and the file
+ descriptor has been opened without O_NONBLOCK, the call will
+ block until the SPU writes to its interrupt mailbox channel.
+ When data has been read successfully, four bytes are placed in
+ the data buffer and the value four is returned.
+
+ poll(2)
+ Poll on the ibox file returns (POLLIN | POLLRDNORM) whenever
+ data is available for reading.
+
+
+ /wbox
+ The CPU to SPU communation mailbox. It is write-only and can be written
+ in units of 32 bits. If the mailbox is full, write() will block and
+ poll can be used to wait for it becoming empty again. The possible
+ operations on an open wbox file are: write(2) If a count smaller than
+ four is requested, write returns -1 and sets errno to EINVAL. If there
+ is no space available in the mail box and the file descriptor has been
+ opened with O_NONBLOCK, the return value is set to -1 and errno becomes
+ EAGAIN.
+
+ If there is no space available in the mail box and the file descriptor
+ has been opened without O_NONBLOCK, the call will block until the SPU
+ reads from its PPE mailbox channel. When data has been read success-
+ fully, four bytes are placed in the data buffer and the value four is
+ returned.
+
+ poll(2)
+ Poll on the ibox file returns (POLLOUT | POLLWRNORM) whenever
+ space is available for writing.
+
+
+ /mbox_stat, /ibox_stat, /wbox_stat
+ Read-only files that contain the length of the current queue, i.e. how
+ many words can be read from mbox or ibox or how many words can be
+ written to wbox without blocking. The files can be read only in 4-byte
+ units and return a big-endian binary integer number. The possible
+ operations on an open ``*box_stat`` file are:
+
+ read(2)
+ If a count smaller than four is requested, read returns -1 and
+ sets errno to EINVAL. Otherwise, a four byte value is placed in
+ the data buffer, containing the number of elements that can be
+ read from (for mbox_stat and ibox_stat) or written to (for
+ wbox_stat) the respective mail box without blocking or resulting
+ in EAGAIN.
+
+
+ /npc, /decr, /decr_status, /spu_tag_mask, /event_mask, /srr0
+ Internal registers of the SPU. The representation is an ASCII string
+ with the numeric value of the next instruction to be executed. These
+ can be used in read/write mode for debugging, but normal operation of
+ programs should not rely on them because access to any of them except
+ npc requires an SPU context save and is therefore very inefficient.
+
+ The contents of these files are:
+
+ =================== ===================================
+ npc Next Program Counter
+ decr SPU Decrementer
+ decr_status Decrementer Status
+ spu_tag_mask MFC tag mask for SPU DMA
+ event_mask Event mask for SPU interrupts
+ srr0 Interrupt Return address register
+ =================== ===================================
+
+
+ The possible operations on an open npc, decr, decr_status,
+ spu_tag_mask, event_mask or srr0 file are:
+
+ read(2)
+ When the count supplied to the read call is shorter than the
+ required length for the pointer value plus a newline character,
+ subsequent reads from the same file descriptor will result in
+ completing the string, regardless of changes to the register by
+ a running SPU task. When a complete string has been read, all
+ subsequent read operations will return zero bytes and a new file
+ descriptor needs to be opened to read the value again.
+
+ write(2)
+ A write operation on the file results in setting the register to
+ the value given in the string. The string is parsed from the
+ beginning to the first non-numeric character or the end of the
+ buffer. Subsequent writes to the same file descriptor overwrite
+ the previous setting.
+
+
+ /fpcr
+ This file gives access to the Floating Point Status and Control Regis-
+ ter as a four byte long file. The operations on the fpcr file are:
+
+ read(2)
+ If a count smaller than four is requested, read returns -1 and
+ sets errno to EINVAL. Otherwise, a four byte value is placed in
+ the data buffer, containing the current value of the fpcr regis-
+ ter.
+
+ write(2)
+ If a count smaller than four is requested, write returns -1 and
+ sets errno to EINVAL. Otherwise, a four byte value is copied
+ from the data buffer, updating the value of the fpcr register.
+
+
+ /signal1, /signal2
+ The two signal notification channels of an SPU. These are read-write
+ files that operate on a 32 bit word. Writing to one of these files
+ triggers an interrupt on the SPU. The value written to the signal
+ files can be read from the SPU through a channel read or from host user
+ space through the file. After the value has been read by the SPU, it
+ is reset to zero. The possible operations on an open signal1 or sig-
+ nal2 file are:
+
+ read(2)
+ If a count smaller than four is requested, read returns -1 and
+ sets errno to EINVAL. Otherwise, a four byte value is placed in
+ the data buffer, containing the current value of the specified
+ signal notification register.
+
+ write(2)
+ If a count smaller than four is requested, write returns -1 and
+ sets errno to EINVAL. Otherwise, a four byte value is copied
+ from the data buffer, updating the value of the specified signal
+ notification register. The signal notification register will
+ either be replaced with the input data or will be updated to the
+ bitwise OR or the old value and the input data, depending on the
+ contents of the signal1_type, or signal2_type respectively,
+ file.
+
+
+ /signal1_type, /signal2_type
+ These two files change the behavior of the signal1 and signal2 notifi-
+ cation files. The contain a numerical ASCII string which is read as
+ either "1" or "0". In mode 0 (overwrite), the hardware replaces the
+ contents of the signal channel with the data that is written to it. in
+ mode 1 (logical OR), the hardware accumulates the bits that are subse-
+ quently written to it. The possible operations on an open signal1_type
+ or signal2_type file are:
+
+ read(2)
+ When the count supplied to the read call is shorter than the
+ required length for the digit plus a newline character, subse-
+ quent reads from the same file descriptor will result in com-
+ pleting the string. When a complete string has been read, all
+ subsequent read operations will return zero bytes and a new file
+ descriptor needs to be opened to read the value again.
+
+ write(2)
+ A write operation on the file results in setting the register to
+ the value given in the string. The string is parsed from the
+ beginning to the first non-numeric character or the end of the
+ buffer. Subsequent writes to the same file descriptor overwrite
+ the previous setting.
+
+
+Examples
+========
+ /etc/fstab entry
+ none /spu spufs gid=spu 0 0
+
+
+Authors
+=======
+ Arnd Bergmann <arndb@de.ibm.com>, Mark Nutter <mnutter@us.ibm.com>,
+ Ulrich Weigand <Ulrich.Weigand@de.ibm.com>
+
+See Also
+========
+ capabilities(7), close(2), spu_create(2), spu_run(2), spufs(7)
diff --git a/Documentation/filesystems/sysfs-pci.txt b/Documentation/filesystems/sysfs-pci.rst
similarity index 91%
rename from Documentation/filesystems/sysfs-pci.txt
rename to Documentation/filesystems/sysfs-pci.rst
index 06f1d64..a265f3e 100644
--- a/Documentation/filesystems/sysfs-pci.txt
+++ b/Documentation/filesystems/sysfs-pci.rst
@@ -1,8 +1,11 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+============================================
Accessing PCI device resources through sysfs
---------------------------------------------
+============================================
sysfs, usually mounted at /sys, provides access to PCI resources on platforms
-that support it. For example, a given bus might look like this:
+that support it. For example, a given bus might look like this::
/sys/devices/pci0000:17
|-- 0000:17:00.0
@@ -30,8 +33,9 @@
numbers are reproduced for convenience. Under the device directory are several
files, each with their own function.
+ =================== =====================================================
file function
- ---- --------
+ =================== =====================================================
class PCI class (ascii, ro)
config PCI config space (binary, rw)
device PCI device (ascii, ro)
@@ -40,13 +44,16 @@
local_cpus nearby CPU mask (cpumask, ro)
remove remove device from kernel's list (ascii, wo)
resource PCI resource host addresses (ascii, ro)
- resource0..N PCI resource N, if present (binary, mmap, rw[1])
+ resource0..N PCI resource N, if present (binary, mmap, rw\ [1]_)
resource0_wc..N_wc PCI WC map resource N, if prefetchable (binary, mmap)
revision PCI revision (ascii, ro)
rom PCI ROM resource, if present (binary, ro)
subsystem_device PCI subsystem device (ascii, ro)
subsystem_vendor PCI subsystem vendor (ascii, ro)
vendor PCI vendor (ascii, ro)
+ =================== =====================================================
+
+::
ro - read only file
rw - file is readable and writable
@@ -56,7 +63,7 @@
binary - file contains binary data
cpumask - file contains a cpumask type
-[1] rw for RESOURCE_IO (I/O port) regions only
+.. [1] rw for RESOURCE_IO (I/O port) regions only
The read only files are informational, writes to them will be ignored, with
the exception of the 'rom' file. Writable files can be used to perform
@@ -67,11 +74,11 @@
value from any attempted mmap. The most notable of these are I/O port
resources, which also provide read/write access.
-The 'enable' file provides a counter that indicates how many times the device
+The 'enable' file provides a counter that indicates how many times the device
has been enabled. If the 'enable' file currently returns '4', and a '1' is
echoed into it, it will then return '5'. Echoing a '0' into it will decrease
the count. Even when it returns to 0, though, some of the initialisation
-may not be reversed.
+may not be reversed.
The 'rom' file is special in that it provides read-only access to the device's
ROM file, if available. It's disabled by default, however, so applications
@@ -93,7 +100,7 @@
Legacy I/O port and ISA memory resources are also provided in sysfs if the
underlying platform supports them. They're located in the PCI class hierarchy,
-e.g.
+e.g.::
/sys/class/pci_bus/0000:17/
|-- bridge -> ../../../devices/pci0000:17
diff --git a/Documentation/filesystems/sysfs-tagging.txt b/Documentation/filesystems/sysfs-tagging.rst
similarity index 72%
rename from Documentation/filesystems/sysfs-tagging.txt
rename to Documentation/filesystems/sysfs-tagging.rst
index c7c8e64..8888a05 100644
--- a/Documentation/filesystems/sysfs-tagging.txt
+++ b/Documentation/filesystems/sysfs-tagging.rst
@@ -1,5 +1,8 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+=============
Sysfs tagging
--------------
+=============
(Taken almost verbatim from Eric Biederman's netns tagging patch
commit msg)
@@ -18,25 +21,28 @@
the network devices.
Each sysfs directory entry may be tagged with a namespace via the
-void *ns member of its kernfs_node. If a directory entry is tagged,
-then kernfs_node->flags will have a flag between KOBJ_NS_TYPE_NONE
+``void *ns member`` of its ``kernfs_node``. If a directory entry is tagged,
+then ``kernfs_node->flags`` will have a flag between KOBJ_NS_TYPE_NONE
and KOBJ_NS_TYPES, and ns will point to the namespace to which it
belongs.
-Each sysfs superblock's kernfs_super_info contains an array void
-*ns[KOBJ_NS_TYPES]. When a task in a tagging namespace
+Each sysfs superblock's kernfs_super_info contains an array
+``void *ns[KOBJ_NS_TYPES]``. When a task in a tagging namespace
kobj_nstype first mounts sysfs, a new superblock is created. It
will be differentiated from other sysfs mounts by having its
-s_fs_info->ns[kobj_nstype] set to the new namespace. Note that
+``s_fs_info->ns[kobj_nstype]`` set to the new namespace. Note that
through bind mounting and mounts propagation, a task can easily view
the contents of other namespaces' sysfs mounts. Therefore, when a
namespace exits, it will call kobj_ns_exit() to invalidate any
kernfs_node->ns pointers pointing to it.
Users of this interface:
-- define a type in the kobj_ns_type enumeration.
-- call kobj_ns_type_register() with its kobj_ns_type_operations which has
+
+- define a type in the ``kobj_ns_type`` enumeration.
+- call kobj_ns_type_register() with its ``kobj_ns_type_operations`` which has
+
- current_ns() which returns current's namespace
- netlink_ns() which returns a socket's namespace
- initial_ns() which returns the initial namesapce
+
- call kobj_ns_exit() when an individual tag is no longer valid
diff --git a/Documentation/filesystems/sysfs.rst b/Documentation/filesystems/sysfs.rst
index 290891c..ab0f779 100644
--- a/Documentation/filesystems/sysfs.rst
+++ b/Documentation/filesystems/sysfs.rst
@@ -20,7 +20,7 @@
linkages between them to userspace.
sysfs is tied inherently to the kobject infrastructure. Please read
-Documentation/kobject.txt for more information concerning the kobject
+Documentation/core-api/kobject.rst for more information concerning the kobject
interface.
diff --git a/Documentation/filesystems/xfs-delayed-logging-design.txt b/Documentation/filesystems/xfs-delayed-logging-design.rst
similarity index 96%
rename from Documentation/filesystems/xfs-delayed-logging-design.txt
rename to Documentation/filesystems/xfs-delayed-logging-design.rst
index 9a6dd28..464405d 100644
--- a/Documentation/filesystems/xfs-delayed-logging-design.txt
+++ b/Documentation/filesystems/xfs-delayed-logging-design.rst
@@ -1,8 +1,11 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+==========================
XFS Delayed Logging Design
---------------------------
+==========================
Introduction to Re-logging in XFS
----------------------------------
+=================================
XFS logging is a combination of logical and physical logging. Some objects,
such as inodes and dquots, are logged in logical format where the details
@@ -25,7 +28,7 @@
That is, if we have a sequence of changes A through to F, and the object was
written to disk after change D, we would see in the log the following series
of transactions, their contents and the log sequence number (LSN) of the
-transaction:
+transaction::
Transaction Contents LSN
A A X
@@ -85,7 +88,7 @@
bound.
Delayed Logging: Concepts
--------------------------
+=========================
The key thing to note about the asynchronous logging combined with the
relogging technique XFS uses is that we can be relogging changed objects
@@ -154,9 +157,10 @@
6. No performance regressions for synchronous transaction workloads.
Delayed Logging: Design
------------------------
+=======================
Storing Changes
+---------------
The problem with accumulating changes at a logical level (i.e. just using the
existing log item dirty region tracking) is that when it comes to writing the
@@ -194,30 +198,30 @@
formatting method and the delayed logging formatting can be seen in the
diagram below.
-Current format log vector:
+Current format log vector::
-Object +---------------------------------------------+
-Vector 1 +----+
-Vector 2 +----+
-Vector 3 +----------+
+ Object +---------------------------------------------+
+ Vector 1 +----+
+ Vector 2 +----+
+ Vector 3 +----------+
-After formatting:
+After formatting::
-Log Buffer +-V1-+-V2-+----V3----+
+ Log Buffer +-V1-+-V2-+----V3----+
-Delayed logging vector:
+Delayed logging vector::
-Object +---------------------------------------------+
-Vector 1 +----+
-Vector 2 +----+
-Vector 3 +----------+
+ Object +---------------------------------------------+
+ Vector 1 +----+
+ Vector 2 +----+
+ Vector 3 +----------+
-After formatting:
+After formatting::
-Memory Buffer +-V1-+-V2-+----V3----+
-Vector 1 +----+
-Vector 2 +----+
-Vector 3 +----------+
+ Memory Buffer +-V1-+-V2-+----V3----+
+ Vector 1 +----+
+ Vector 2 +----+
+ Vector 3 +----------+
The memory buffer and associated vector need to be passed as a single object,
but still need to be associated with the parent object so if the object is
@@ -242,6 +246,7 @@
Tracking Changes
+----------------
Now that we can record transactional changes in memory in a form that allows
them to be used without limitations, we need to be able to track and accumulate
@@ -278,6 +283,7 @@
Delayed Logging: Checkpoints
+----------------------------
When we have a log synchronisation event, commonly known as a "log force",
all the items in the CIL must be written into the log via the log buffers.
@@ -341,7 +347,7 @@
detached from the log items. That is, when the CIL is flushed the memory
buffer and log vector attached to each log item needs to be attached to the
checkpoint context so that the log item can be released. In diagrammatic form,
-the CIL would look like this before the flush:
+the CIL would look like this before the flush::
CIL Head
|
@@ -362,7 +368,7 @@
-> vector array
And after the flush the CIL head is empty, and the checkpoint context log
-vector list would look like:
+vector list would look like::
Checkpoint Context
|
@@ -411,6 +417,7 @@
is in the dev tree....
Delayed Logging: Checkpoint Sequencing
+--------------------------------------
One of the key aspects of the XFS transaction subsystem is that it tags
committed transactions with the log sequence number of the transaction commit.
@@ -474,6 +481,7 @@
behaves the same regardless of whether delayed logging is being used or not.
Delayed Logging: Checkpoint Log Space Accounting
+------------------------------------------------
The big issue for a checkpoint transaction is the log space reservation for the
transaction. We don't know how big a checkpoint transaction is going to be
@@ -491,7 +499,7 @@
of log vectors in the transaction).
An example of the differences would be logging directory changes versus logging
-inode changes. If you modify lots of inode cores (e.g. chmod -R g+w *), then
+inode changes. If you modify lots of inode cores (e.g. ``chmod -R g+w *``), then
there are lots of transactions that only contain an inode core and an inode log
format structure. That is, two vectors totaling roughly 150 bytes. If we modify
10,000 inodes, we have about 1.5MB of metadata to write in 20,000 vectors. Each
@@ -565,6 +573,7 @@
Delayed Logging: Log Item Pinning
+---------------------------------
Currently log items are pinned during transaction commit while the items are
still locked. This happens just after the items are formatted, though it could
@@ -605,6 +614,7 @@
lock to guarantee that we pin the items correctly.
Delayed Logging: Concurrent Scalability
+---------------------------------------
A fundamental requirement for the CIL is that accesses through transaction
commits must scale to many concurrent commits. The current transaction commit
@@ -683,8 +693,9 @@
Lifecycle Changes
+-----------------
-The existing log item life cycle is as follows:
+The existing log item life cycle is as follows::
1. Transaction allocate
2. Transaction reserve
@@ -729,7 +740,7 @@
and steps 1-6 are re-entered, then the item is relogged. Only when steps 8-9
are entered and completed is the object considered clean.
-With delayed logging, there are new steps inserted into the life cycle:
+With delayed logging, there are new steps inserted into the life cycle::
1. Transaction allocate
2. Transaction reserve
diff --git a/Documentation/filesystems/xfs-self-describing-metadata.txt b/Documentation/filesystems/xfs-self-describing-metadata.rst
similarity index 83%
rename from Documentation/filesystems/xfs-self-describing-metadata.txt
rename to Documentation/filesystems/xfs-self-describing-metadata.rst
index 8db0121d..51cdafe 100644
--- a/Documentation/filesystems/xfs-self-describing-metadata.txt
+++ b/Documentation/filesystems/xfs-self-describing-metadata.rst
@@ -1,8 +1,11 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+============================
XFS Self Describing Metadata
-----------------------------
+============================
Introduction
-------------
+============
The largest scalability problem facing XFS is not one of algorithmic
scalability, but of verification of the filesystem structure. Scalabilty of the
@@ -34,7 +37,7 @@
Self Describing Metadata
-------------------------
+========================
One of the problems with the current metadata format is that apart from the
magic number in the metadata block, we have no other way of identifying what it
@@ -142,7 +145,7 @@
detected.
Runtime Validation
-------------------
+==================
Validation of self-describing metadata takes place at runtime in two places:
@@ -183,18 +186,18 @@
error for the higher layers to catch.
Structures
-----------
+==========
-A typical on-disk structure needs to contain the following information:
+A typical on-disk structure needs to contain the following information::
-struct xfs_ondisk_hdr {
- __be32 magic; /* magic number */
- __be32 crc; /* CRC, not logged */
- uuid_t uuid; /* filesystem identifier */
- __be64 owner; /* parent object */
- __be64 blkno; /* location on disk */
- __be64 lsn; /* last modification in log, not logged */
-};
+ struct xfs_ondisk_hdr {
+ __be32 magic; /* magic number */
+ __be32 crc; /* CRC, not logged */
+ uuid_t uuid; /* filesystem identifier */
+ __be64 owner; /* parent object */
+ __be64 blkno; /* location on disk */
+ __be64 lsn; /* last modification in log, not logged */
+ };
Depending on the metadata, this information may be part of a header structure
separate to the metadata contents, or may be distributed through an existing
@@ -214,24 +217,24 @@
well. hence the additional metadata headers change the overall format
of the metadata.
-A typical buffer read verifier is structured as follows:
+A typical buffer read verifier is structured as follows::
-#define XFS_FOO_CRC_OFF offsetof(struct xfs_ondisk_hdr, crc)
+ #define XFS_FOO_CRC_OFF offsetof(struct xfs_ondisk_hdr, crc)
-static void
-xfs_foo_read_verify(
- struct xfs_buf *bp)
-{
- struct xfs_mount *mp = bp->b_mount;
+ static void
+ xfs_foo_read_verify(
+ struct xfs_buf *bp)
+ {
+ struct xfs_mount *mp = bp->b_mount;
- if ((xfs_sb_version_hascrc(&mp->m_sb) &&
- !xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
- XFS_FOO_CRC_OFF)) ||
- !xfs_foo_verify(bp)) {
- XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
- xfs_buf_ioerror(bp, EFSCORRUPTED);
- }
-}
+ if ((xfs_sb_version_hascrc(&mp->m_sb) &&
+ !xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
+ XFS_FOO_CRC_OFF)) ||
+ !xfs_foo_verify(bp)) {
+ XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
+ xfs_buf_ioerror(bp, EFSCORRUPTED);
+ }
+ }
The code ensures that the CRC is only checked if the filesystem has CRCs enabled
by checking the superblock of the feature bit, and then if the CRC verifies OK
@@ -239,83 +242,83 @@
The verifier function will take a couple of different forms, depending on
whether the magic number can be used to determine the format of the block. In
-the case it can't, the code is structured as follows:
+the case it can't, the code is structured as follows::
-static bool
-xfs_foo_verify(
- struct xfs_buf *bp)
-{
- struct xfs_mount *mp = bp->b_mount;
- struct xfs_ondisk_hdr *hdr = bp->b_addr;
+ static bool
+ xfs_foo_verify(
+ struct xfs_buf *bp)
+ {
+ struct xfs_mount *mp = bp->b_mount;
+ struct xfs_ondisk_hdr *hdr = bp->b_addr;
- if (hdr->magic != cpu_to_be32(XFS_FOO_MAGIC))
- return false;
+ if (hdr->magic != cpu_to_be32(XFS_FOO_MAGIC))
+ return false;
- if (!xfs_sb_version_hascrc(&mp->m_sb)) {
- if (!uuid_equal(&hdr->uuid, &mp->m_sb.sb_uuid))
- return false;
- if (bp->b_bn != be64_to_cpu(hdr->blkno))
- return false;
- if (hdr->owner == 0)
- return false;
- }
+ if (!xfs_sb_version_hascrc(&mp->m_sb)) {
+ if (!uuid_equal(&hdr->uuid, &mp->m_sb.sb_uuid))
+ return false;
+ if (bp->b_bn != be64_to_cpu(hdr->blkno))
+ return false;
+ if (hdr->owner == 0)
+ return false;
+ }
- /* object specific verification checks here */
+ /* object specific verification checks here */
- return true;
-}
+ return true;
+ }
If there are different magic numbers for the different formats, the verifier
-will look like:
+will look like::
-static bool
-xfs_foo_verify(
- struct xfs_buf *bp)
-{
- struct xfs_mount *mp = bp->b_mount;
- struct xfs_ondisk_hdr *hdr = bp->b_addr;
+ static bool
+ xfs_foo_verify(
+ struct xfs_buf *bp)
+ {
+ struct xfs_mount *mp = bp->b_mount;
+ struct xfs_ondisk_hdr *hdr = bp->b_addr;
- if (hdr->magic == cpu_to_be32(XFS_FOO_CRC_MAGIC)) {
- if (!uuid_equal(&hdr->uuid, &mp->m_sb.sb_uuid))
- return false;
- if (bp->b_bn != be64_to_cpu(hdr->blkno))
- return false;
- if (hdr->owner == 0)
- return false;
- } else if (hdr->magic != cpu_to_be32(XFS_FOO_MAGIC))
- return false;
+ if (hdr->magic == cpu_to_be32(XFS_FOO_CRC_MAGIC)) {
+ if (!uuid_equal(&hdr->uuid, &mp->m_sb.sb_uuid))
+ return false;
+ if (bp->b_bn != be64_to_cpu(hdr->blkno))
+ return false;
+ if (hdr->owner == 0)
+ return false;
+ } else if (hdr->magic != cpu_to_be32(XFS_FOO_MAGIC))
+ return false;
- /* object specific verification checks here */
+ /* object specific verification checks here */
- return true;
-}
+ return true;
+ }
Write verifiers are very similar to the read verifiers, they just do things in
-the opposite order to the read verifiers. A typical write verifier:
+the opposite order to the read verifiers. A typical write verifier::
-static void
-xfs_foo_write_verify(
- struct xfs_buf *bp)
-{
- struct xfs_mount *mp = bp->b_mount;
- struct xfs_buf_log_item *bip = bp->b_fspriv;
+ static void
+ xfs_foo_write_verify(
+ struct xfs_buf *bp)
+ {
+ struct xfs_mount *mp = bp->b_mount;
+ struct xfs_buf_log_item *bip = bp->b_fspriv;
- if (!xfs_foo_verify(bp)) {
- XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
- xfs_buf_ioerror(bp, EFSCORRUPTED);
- return;
- }
+ if (!xfs_foo_verify(bp)) {
+ XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
+ xfs_buf_ioerror(bp, EFSCORRUPTED);
+ return;
+ }
- if (!xfs_sb_version_hascrc(&mp->m_sb))
- return;
+ if (!xfs_sb_version_hascrc(&mp->m_sb))
+ return;
- if (bip) {
- struct xfs_ondisk_hdr *hdr = bp->b_addr;
- hdr->lsn = cpu_to_be64(bip->bli_item.li_lsn);
- }
- xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length), XFS_FOO_CRC_OFF);
-}
+ if (bip) {
+ struct xfs_ondisk_hdr *hdr = bp->b_addr;
+ hdr->lsn = cpu_to_be64(bip->bli_item.li_lsn);
+ }
+ xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length), XFS_FOO_CRC_OFF);
+ }
This will verify the internal structure of the metadata before we go any
further, detecting corruptions that have occurred as the metadata has been
@@ -324,7 +327,7 @@
metadata. Once this is done, we can issue the IO.
Inodes and Dquots
------------------
+=================
Inodes and dquots are special snowflakes. They have per-object CRC and
self-identifiers, but they are packed so that there are multiple objects per
@@ -347,4 +350,3 @@
the unlinked list modifications check or update CRCs, neither during unlink nor
log recovery. So, it's gone unnoticed until now. This won't matter immediately -
repair will probably complain about it - but it needs to be fixed.
-
diff --git a/Documentation/i2c/i2c.svg b/Documentation/i2c/i2c_bus.svg
similarity index 99%
rename from Documentation/i2c/i2c.svg
rename to Documentation/i2c/i2c_bus.svg
index 5979405..3170de9 100644
--- a/Documentation/i2c/i2c.svg
+++ b/Documentation/i2c/i2c_bus.svg
@@ -9,7 +9,7 @@
xmlns="http://www.w3.org/2000/svg"
xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
- sodipodi:docname="i2c.svg"
+ sodipodi:docname="i2c_bus.svg"
inkscape:version="0.92.3 (2405546, 2018-03-11)"
version="1.1"
id="svg2"
diff --git a/Documentation/i2c/summary.rst b/Documentation/i2c/summary.rst
index ce72300..136c4e3 100644
--- a/Documentation/i2c/summary.rst
+++ b/Documentation/i2c/summary.rst
@@ -34,7 +34,7 @@
Using the terminology from the official documentation, the I2C bus connects
one or more *master* chips and one or more *slave* chips.
-.. kernel-figure:: i2c.svg
+.. kernel-figure:: i2c_bus.svg
:alt: Simple I2C bus with one master and 3 slaves
Simple I2C bus
diff --git a/Documentation/ia64/irq-redir.rst b/Documentation/ia64/irq-redir.rst
index 39bf944..6bbbbe4 100644
--- a/Documentation/ia64/irq-redir.rst
+++ b/Documentation/ia64/irq-redir.rst
@@ -7,7 +7,7 @@
By writing to /proc/irq/IRQ#/smp_affinity the interrupt routing can be
controlled. The behavior on IA64 platforms is slightly different from
-that described in Documentation/IRQ-affinity.txt for i386 systems.
+that described in Documentation/core-api/irq/irq-affinity.rst for i386 systems.
Because of the usage of SAPIC mode and physical destination mode the
IRQ target is one particular CPU and cannot be a mask of several
diff --git a/Documentation/iio/iio_configfs.rst b/Documentation/iio/iio_configfs.rst
index ecbfdb3..6e38cbb 100644
--- a/Documentation/iio/iio_configfs.rst
+++ b/Documentation/iio/iio_configfs.rst
@@ -9,7 +9,7 @@
objects that could be easily configured using configfs (e.g.: devices,
triggers).
-See Documentation/filesystems/configfs/configfs.txt for more information
+See Documentation/filesystems/configfs.rst for more information
about how configfs works.
2. Usage
diff --git a/Documentation/futex-requeue-pi.txt b/Documentation/locking/futex-requeue-pi.rst
similarity index 100%
rename from Documentation/futex-requeue-pi.txt
rename to Documentation/locking/futex-requeue-pi.rst
diff --git a/Documentation/hwspinlock.txt b/Documentation/locking/hwspinlock.rst
similarity index 100%
rename from Documentation/hwspinlock.txt
rename to Documentation/locking/hwspinlock.rst
diff --git a/Documentation/locking/index.rst b/Documentation/locking/index.rst
index 5d6800a..d785878 100644
--- a/Documentation/locking/index.rst
+++ b/Documentation/locking/index.rst
@@ -16,6 +16,13 @@
rt-mutex
spinlocks
ww-mutex-design
+ preempt-locking
+ pi-futex
+ futex-requeue-pi
+ hwspinlock
+ percpu-rw-semaphore
+ robust-futexes
+ robust-futex-ABI
.. only:: subproject and html
diff --git a/Documentation/locking/locktorture.rst b/Documentation/locking/locktorture.rst
index 5bcb99b..8012a74 100644
--- a/Documentation/locking/locktorture.rst
+++ b/Documentation/locking/locktorture.rst
@@ -110,7 +110,7 @@
same period of time. Defaults to "stutter=5", so as
to run and pause for (roughly) five-second intervals.
Specifying "stutter=0" causes the test to run continuously
- without pausing, which is the old default behavior.
+ without pausing.
shuffle_interval
The number of seconds to keep the test threads affinitied
diff --git a/Documentation/percpu-rw-semaphore.txt b/Documentation/locking/percpu-rw-semaphore.rst
similarity index 100%
rename from Documentation/percpu-rw-semaphore.txt
rename to Documentation/locking/percpu-rw-semaphore.rst
diff --git a/Documentation/pi-futex.txt b/Documentation/locking/pi-futex.rst
similarity index 100%
rename from Documentation/pi-futex.txt
rename to Documentation/locking/pi-futex.rst
diff --git a/Documentation/preempt-locking.txt b/Documentation/locking/preempt-locking.rst
similarity index 100%
rename from Documentation/preempt-locking.txt
rename to Documentation/locking/preempt-locking.rst
diff --git a/Documentation/robust-futex-ABI.txt b/Documentation/locking/robust-futex-ABI.rst
similarity index 100%
rename from Documentation/robust-futex-ABI.txt
rename to Documentation/locking/robust-futex-ABI.rst
diff --git a/Documentation/robust-futexes.txt b/Documentation/locking/robust-futexes.rst
similarity index 100%
rename from Documentation/robust-futexes.txt
rename to Documentation/locking/robust-futexes.rst
diff --git a/Documentation/locking/rt-mutex.rst b/Documentation/locking/rt-mutex.rst
index c365dc3..3b5097a 100644
--- a/Documentation/locking/rt-mutex.rst
+++ b/Documentation/locking/rt-mutex.rst
@@ -4,7 +4,7 @@
RT-mutexes with priority inheritance are used to support PI-futexes,
which enable pthread_mutex_t priority inheritance attributes
-(PTHREAD_PRIO_INHERIT). [See Documentation/pi-futex.txt for more details
+(PTHREAD_PRIO_INHERIT). [See Documentation/locking/pi-futex.rst for more details
about PI-futexes.]
This technology was developed in the -rt tree and streamlined for
diff --git a/Documentation/maintainer/maintainer-entry-profile.rst b/Documentation/maintainer/maintainer-entry-profile.rst
index 11ebe36..77e43c8 100644
--- a/Documentation/maintainer/maintainer-entry-profile.rst
+++ b/Documentation/maintainer/maintainer-entry-profile.rst
@@ -7,7 +7,7 @@
(submitting-patches, submitting drivers...) with
subsystem/device-driver-local customs as well as details about the patch
submission life-cycle. A contributor uses this document to level set
-their expectations and avoid common mistakes, maintainers may use these
+their expectations and avoid common mistakes; maintainers may use these
profiles to look across subsystems for opportunities to converge on
common practices.
@@ -26,7 +26,7 @@
- Does the subsystem have a patchwork instance? Are patchwork state
changes notified?
- Any bots or CI infrastructure that watches the list, or automated
- testing feedback that the subsystem gates acceptance?
+ testing feedback that the subsystem uses to gate acceptance?
- Git branches that are pulled into -next?
- What branch should contributors submit against?
- Links to any other Maintainer Entry Profiles? For example a
@@ -54,8 +54,8 @@
sent at any time before the merge window closes and can still be
considered for the next -rc1. The reality is that most patches need to
be settled in soaking in linux-next in advance of the merge window
-opening. Clarify for the submitter the key dates (in terms rc release
-week) that patches might considered for merging and when patches need to
+opening. Clarify for the submitter the key dates (in terms of -rc release
+week) that patches might be considered for merging and when patches need to
wait for the next -rc. At a minimum:
- Last -rc for new feature submissions:
@@ -70,8 +70,8 @@
- Last -rc to merge features: Deadline for merge decisions
Indicate to contributors the point at which an as yet un-applied patch
set will need to wait for the NEXT+1 merge window. Of course there is no
- obligation to ever except any given patchset, but if the review has not
- concluded by this point the expectation the contributor should wait and
+ obligation to ever accept any given patchset, but if the review has not
+ concluded by this point the expectation is the contributor should wait and
resubmit for the following merge window.
Optional:
diff --git a/Documentation/memory-barriers.txt b/Documentation/memory-barriers.txt
index e1c355e..eaabc31 100644
--- a/Documentation/memory-barriers.txt
+++ b/Documentation/memory-barriers.txt
@@ -620,7 +620,7 @@
until they are certain (1) that the write will actually happen, (2)
of the location of the write, and (3) of the value to be written.
But please carefully read the "CONTROL DEPENDENCIES" section and the
-Documentation/RCU/rcu_dereference.txt file: The compiler can and does
+Documentation/RCU/rcu_dereference.rst file: The compiler can and does
break dependencies in a great many highly creative ways.
CPU 1 CPU 2
diff --git a/Documentation/misc-devices/index.rst b/Documentation/misc-devices/index.rst
index c1dcd26..1ecc05f 100644
--- a/Documentation/misc-devices/index.rst
+++ b/Documentation/misc-devices/index.rst
@@ -21,4 +21,5 @@
lis3lv02d
max6875
mic/index
+ uacce
xilinx_sdfec
diff --git a/Documentation/networking/scaling.rst b/Documentation/networking/scaling.rst
index f78d7bf..8f0347b 100644
--- a/Documentation/networking/scaling.rst
+++ b/Documentation/networking/scaling.rst
@@ -81,7 +81,7 @@
an IRQ may be handled on any CPU. Because a non-negligible part of packet
processing takes place in receive interrupt handling, it is advantageous
to spread receive interrupts between CPUs. To manually adjust the IRQ
-affinity of each interrupt see Documentation/IRQ-affinity.txt. Some systems
+affinity of each interrupt see Documentation/core-api/irq/irq-affinity.rst. Some systems
will be running irqbalance, a daemon that dynamically optimizes IRQ
assignments and as a result may override any manual settings.
@@ -160,7 +160,7 @@
This file implements a bitmap of CPUs. RPS is disabled when it is zero
(the default), in which case packets are processed on the interrupting
-CPU. Documentation/IRQ-affinity.txt explains how CPUs are assigned to
+CPU. Documentation/core-api/irq/irq-affinity.rst explains how CPUs are assigned to
the bitmap.
diff --git a/Documentation/nvdimm/maintainer-entry-profile.rst b/Documentation/nvdimm/maintainer-entry-profile.rst
index efe37ad..9da748e 100644
--- a/Documentation/nvdimm/maintainer-entry-profile.rst
+++ b/Documentation/nvdimm/maintainer-entry-profile.rst
@@ -4,15 +4,15 @@
Overview
--------
The libnvdimm subsystem manages persistent memory across multiple
-architectures. The mailing list, is tracked by patchwork here:
+architectures. The mailing list is tracked by patchwork here:
https://patchwork.kernel.org/project/linux-nvdimm/list/
...and that instance is configured to give feedback to submitters on
patch acceptance and upstream merge. Patches are merged to either the
-'libnvdimm-fixes', or 'libnvdimm-for-next' branch. Those branches are
+'libnvdimm-fixes' or 'libnvdimm-for-next' branch. Those branches are
available here:
https://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm.git/
-In general patches can be submitted against the latest -rc, however if
+In general patches can be submitted against the latest -rc; however, if
the incoming code change is dependent on other pending changes then the
patch should be based on the libnvdimm-for-next branch. However, since
persistent memory sits at the intersection of storage and memory there
@@ -35,12 +35,12 @@
ACPI Device Specific Methods (_DSM)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-Before patches enabling for a new _DSM family will be considered it must
+Before patches enabling a new _DSM family will be considered, it must
be assigned a format-interface-code from the NVDIMM Sub-team of the ACPI
Specification Working Group. In general, the stance of the subsystem is
-to push back on the proliferation of NVDIMM command sets, do strongly
+to push back on the proliferation of NVDIMM command sets, so do strongly
consider implementing support for an existing command set. See
-drivers/acpi/nfit/nfit.h for the set of support command sets.
+drivers/acpi/nfit/nfit.h for the set of supported command sets.
Key Cycle Dates
@@ -48,7 +48,7 @@
New submissions can be sent at any time, but if they intend to hit the
next merge window they should be sent before -rc4, and ideally
stabilized in the libnvdimm-for-next branch by -rc6. Of course if a
-patch set requires more than 2 weeks of review -rc4 is already too late
+patch set requires more than 2 weeks of review, -rc4 is already too late
and some patches may require multiple development cycles to review.
diff --git a/Documentation/powerpc/cxl.rst b/Documentation/powerpc/cxl.rst
index 920546d..d2d7705 100644
--- a/Documentation/powerpc/cxl.rst
+++ b/Documentation/powerpc/cxl.rst
@@ -133,6 +133,7 @@
========
1. AFU character devices
+^^^^^^^^^^^^^^^^^^^^^^^^
For AFUs operating in AFU directed mode, two character device
files will be created. /dev/cxl/afu0.0m will correspond to a
@@ -395,6 +396,7 @@
2. Card character device (powerVM guest only)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
In a powerVM guest, an extra character device is created for the
card. The device is only used to write (flash) a new image on the
diff --git a/Documentation/powerpc/firmware-assisted-dump.rst b/Documentation/powerpc/firmware-assisted-dump.rst
index b3f3ee1..20ea8cd 100644
--- a/Documentation/powerpc/firmware-assisted-dump.rst
+++ b/Documentation/powerpc/firmware-assisted-dump.rst
@@ -344,7 +344,7 @@
NOTE:
- Please refer to Documentation/filesystems/debugfs.txt on
+ Please refer to Documentation/filesystems/debugfs.rst on
how to mount the debugfs filesystem.
diff --git a/Documentation/process/adding-syscalls.rst b/Documentation/process/adding-syscalls.rst
index 1c3a840..a6b4a3a 100644
--- a/Documentation/process/adding-syscalls.rst
+++ b/Documentation/process/adding-syscalls.rst
@@ -33,7 +33,7 @@
to a somewhat opaque API.
- If you're just exposing runtime system information, a new node in sysfs
- (see ``Documentation/filesystems/sysfs.txt``) or the ``/proc`` filesystem may
+ (see ``Documentation/filesystems/sysfs.rst``) or the ``/proc`` filesystem may
be more appropriate. However, access to these mechanisms requires that the
relevant filesystem is mounted, which might not always be the case (e.g.
in a namespaced/sandboxed/chrooted environment). Avoid adding any API to
diff --git a/Documentation/process/index.rst b/Documentation/process/index.rst
index 6399d92..f07c925 100644
--- a/Documentation/process/index.rst
+++ b/Documentation/process/index.rst
@@ -61,6 +61,7 @@
botching-up-ioctls
clang-format
../riscv/patch-acceptance
+ unaligned-memory-access
.. only:: subproject and html
diff --git a/Documentation/process/submit-checklist.rst b/Documentation/process/submit-checklist.rst
index 8e56337..3f8e9d5 100644
--- a/Documentation/process/submit-checklist.rst
+++ b/Documentation/process/submit-checklist.rst
@@ -107,7 +107,7 @@
and why.
26) If any ioctl's are added by the patch, then also update
- ``Documentation/ioctl/ioctl-number.rst``.
+ ``Documentation/userspace-api/ioctl/ioctl-number.rst``.
27) If your modified source code depends on or uses any of the kernel
APIs or features that are related to the following ``Kconfig`` symbols,
diff --git a/Documentation/unaligned-memory-access.txt b/Documentation/process/unaligned-memory-access.rst
similarity index 100%
rename from Documentation/unaligned-memory-access.txt
rename to Documentation/process/unaligned-memory-access.rst
diff --git a/Documentation/s390/vfio-ap.rst b/Documentation/s390/vfio-ap.rst
index b5c51f7..367e27e 100644
--- a/Documentation/s390/vfio-ap.rst
+++ b/Documentation/s390/vfio-ap.rst
@@ -484,7 +484,7 @@
05.00ff CEX5A Accelerator
=========== ===== ============
-Guest2
+Guest3
------
=========== ===== ============
CARD.DOMAIN TYPE MODE
diff --git a/Documentation/scheduler/sched-domains.rst b/Documentation/scheduler/sched-domains.rst
index f750422..5c4b7f4 100644
--- a/Documentation/scheduler/sched-domains.rst
+++ b/Documentation/scheduler/sched-domains.rst
@@ -19,10 +19,12 @@
Each scheduling domain must have one or more CPU groups (struct sched_group)
which are organised as a circular one way linked list from the ->groups
pointer. The union of cpumasks of these groups MUST be the same as the
-domain's span. The intersection of cpumasks from any two of these groups
-MUST be the empty set. The group pointed to by the ->groups pointer MUST
-contain the CPU to which the domain belongs. Groups may be shared among
-CPUs as they contain read only data after they have been set up.
+domain's span. The group pointed to by the ->groups pointer MUST contain the CPU
+to which the domain belongs. Groups may be shared among CPUs as they contain
+read only data after they have been set up. The intersection of cpumasks from
+any two of these groups may be non empty. If this is the case the SD_OVERLAP
+flag is set on the corresponding scheduling domain and its groups may not be
+shared between CPUs.
Balancing within a sched domain occurs between groups. That is, each group
is treated as one entity. The load of a group is defined as the sum of the
diff --git a/Documentation/digsig.txt b/Documentation/security/digsig.rst
similarity index 100%
rename from Documentation/digsig.txt
rename to Documentation/security/digsig.rst
diff --git a/Documentation/security/index.rst b/Documentation/security/index.rst
index fc503dd..8129405 100644
--- a/Documentation/security/index.rst
+++ b/Documentation/security/index.rst
@@ -15,3 +15,4 @@
self-protection
siphash
tpm/index
+ digsig
diff --git a/Documentation/security/lsm.rst b/Documentation/security/lsm.rst
index aadf47c..6a2a2e9 100644
--- a/Documentation/security/lsm.rst
+++ b/Documentation/security/lsm.rst
@@ -35,47 +35,50 @@
migrating the Linux capabilities code into such a module.
The Linux Security Modules (LSM) project was started by WireX to develop
-such a framework. LSM is a joint development effort by several security
+such a framework. LSM was a joint development effort by several security
projects, including Immunix, SELinux, SGI and Janus, and several
individuals, including Greg Kroah-Hartman and James Morris, to develop a
-Linux kernel patch that implements this framework. The patch is
-currently tracking the 2.4 series and is targeted for integration into
-the 2.5 development series. This technical report provides an overview
-of the framework and the example capabilities security module provided
-by the LSM kernel patch.
+Linux kernel patch that implements this framework. The work was
+incorporated in the mainstream in December of 2003. This technical
+report provides an overview of the framework and the capabilities
+security module.
LSM Framework
=============
-The LSM kernel patch provides a general kernel framework to support
+The LSM framework provides a general kernel framework to support
security modules. In particular, the LSM framework is primarily focused
on supporting access control modules, although future development is
-likely to address other security needs such as auditing. By itself, the
+likely to address other security needs such as sandboxing. By itself, the
framework does not provide any additional security; it merely provides
-the infrastructure to support security modules. The LSM kernel patch
-also moves most of the capabilities logic into an optional security
-module, with the system defaulting to the traditional superuser logic.
+the infrastructure to support security modules. The LSM framework is
+optional, requiring `CONFIG_SECURITY` to be enabled. The capabilities
+logic is implemented as a security module.
This capabilities module is discussed further in
`LSM Capabilities Module`_.
-The LSM kernel patch adds security fields to kernel data structures and
-inserts calls to hook functions at critical points in the kernel code to
-manage the security fields and to perform access control. It also adds
-functions for registering and unregistering security modules, and adds a
-general :c:func:`security()` system call to support new system calls
-for security-aware applications.
+The LSM framework includes security fields in kernel data structures and
+calls to hook functions at critical points in the kernel code to
+manage the security fields and to perform access control.
+It also adds functions for registering security modules.
+An interface `/sys/kernel/security/lsm` reports a comma separated list
+of security modules that are active on the system.
-The LSM security fields are simply ``void*`` pointers. For process and
-program execution security information, security fields were added to
+The LSM security fields are simply ``void*`` pointers.
+The data is referred to as a blob, which may be managed by
+the framework or by the individual security modules that use it.
+Security blobs that are used by more than one security module are
+typically managed by the framework.
+For process and
+program execution security information, security fields are included in
:c:type:`struct task_struct <task_struct>` and
-:c:type:`struct linux_binprm <linux_binprm>`. For filesystem
-security information, a security field was added to :c:type:`struct
+:c:type:`struct cred <cred>`.
+For filesystem
+security information, a security field is included in :c:type:`struct
super_block <super_block>`. For pipe, file, and socket security
-information, security fields were added to :c:type:`struct inode
-<inode>` and :c:type:`struct file <file>`. For packet and
-network device security information, security fields were added to
-:c:type:`struct sk_buff <sk_buff>` and :c:type:`struct
-net_device <net_device>`. For System V IPC security information,
+information, security fields are included in :c:type:`struct inode
+<inode>` and :c:type:`struct file <file>`.
+For System V IPC security information,
security fields were added to :c:type:`struct kern_ipc_perm
<kern_ipc_perm>` and :c:type:`struct msg_msg
<msg_msg>`; additionally, the definitions for :c:type:`struct
@@ -84,118 +87,45 @@
``include/linux/shm.h`` as appropriate) to allow the security modules to
use these definitions.
-Each LSM hook is a function pointer in a global table, security_ops.
-This table is a :c:type:`struct security_operations
-<security_operations>` structure as defined by
-``include/linux/security.h``. Detailed documentation for each hook is
-included in this header file. At present, this structure consists of a
-collection of substructures that group related hooks based on the kernel
-object (e.g. task, inode, file, sk_buff, etc) as well as some top-level
-hook function pointers for system operations. This structure is likely
-to be flattened in the future for performance. The placement of the hook
-calls in the kernel code is described by the "called:" lines in the
-per-hook documentation in the header file. The hook calls can also be
-easily found in the kernel code by looking for the string
-"security_ops->".
+For packet and
+network device security information, security fields were added to
+:c:type:`struct sk_buff <sk_buff>` and
+:c:type:`struct scm_cookie <scm_cookie>`.
+Unlike the other security module data, the data used here is a
+32-bit integer. The security modules are required to map or otherwise
+associate these values with real security attributes.
-Linus mentioned per-process security hooks in his original remarks as a
-possible alternative to global security hooks. However, if LSM were to
-start from the perspective of per-process hooks, then the base framework
-would have to deal with how to handle operations that involve multiple
-processes (e.g. kill), since each process might have its own hook for
-controlling the operation. This would require a general mechanism for
-composing hooks in the base framework. Additionally, LSM would still
-need global hooks for operations that have no process context (e.g.
-network input operations). Consequently, LSM provides global security
-hooks, but a security module is free to implement per-process hooks
-(where that makes sense) by storing a security_ops table in each
-process' security field and then invoking these per-process hooks from
-the global hooks. The problem of composition is thus deferred to the
-module.
+LSM hooks are maintained in lists. A list is maintained for each
+hook, and the hooks are called in the order specified by CONFIG_LSM.
+Detailed documentation for each hook is
+included in the `include/linux/lsm_hooks.h` header file.
-The global security_ops table is initialized to a set of hook functions
-provided by a dummy security module that provides traditional superuser
-logic. A :c:func:`register_security()` function (in
-``security/security.c``) is provided to allow a security module to set
-security_ops to refer to its own hook functions, and an
-:c:func:`unregister_security()` function is provided to revert
-security_ops to the dummy module hooks. This mechanism is used to set
-the primary security module, which is responsible for making the final
-decision for each hook.
+The LSM framework provides for a close approximation of
+general security module stacking. It defines
+security_add_hooks() to which each security module passes a
+:c:type:`struct security_hooks_list <security_hooks_list>`,
+which are added to the lists.
+The LSM framework does not provide a mechanism for removing hooks that
+have been registered. The SELinux security module has implemented
+a way to remove itself, however the feature has been deprecated.
-LSM also provides a simple mechanism for stacking additional security
-modules with the primary security module. It defines
-:c:func:`register_security()` and
-:c:func:`unregister_security()` hooks in the :c:type:`struct
-security_operations <security_operations>` structure and
-provides :c:func:`mod_reg_security()` and
-:c:func:`mod_unreg_security()` functions that invoke these hooks
-after performing some sanity checking. A security module can call these
-functions in order to stack with other modules. However, the actual
-details of how this stacking is handled are deferred to the module,
-which can implement these hooks in any way it wishes (including always
-returning an error if it does not wish to support stacking). In this
-manner, LSM again defers the problem of composition to the module.
-
-Although the LSM hooks are organized into substructures based on kernel
-object, all of the hooks can be viewed as falling into two major
+The hooks can be viewed as falling into two major
categories: hooks that are used to manage the security fields and hooks
that are used to perform access control. Examples of the first category
-of hooks include the :c:func:`alloc_security()` and
-:c:func:`free_security()` hooks defined for each kernel data
-structure that has a security field. These hooks are used to allocate
-and free security structures for kernel objects. The first category of
-hooks also includes hooks that set information in the security field
-after allocation, such as the :c:func:`post_lookup()` hook in
-:c:type:`struct inode_security_ops <inode_security_ops>`.
-This hook is used to set security information for inodes after
-successful lookup operations. An example of the second category of hooks
-is the :c:func:`permission()` hook in :c:type:`struct
-inode_security_ops <inode_security_ops>`. This hook checks
-permission when accessing an inode.
+of hooks include the security_inode_alloc() and security_inode_free()
+These hooks are used to allocate
+and free security structures for inode objects.
+An example of the second category of hooks
+is the security_inode_permission() hook.
+This hook checks permission when accessing an inode.
LSM Capabilities Module
=======================
-The LSM kernel patch moves most of the existing POSIX.1e capabilities
-logic into an optional security module stored in the file
-``security/capability.c``. This change allows users who do not want to
-use capabilities to omit this code entirely from their kernel, instead
-using the dummy module for traditional superuser logic or any other
-module that they desire. This change also allows the developers of the
-capabilities logic to maintain and enhance their code more freely,
-without needing to integrate patches back into the base kernel.
-
-In addition to moving the capabilities logic, the LSM kernel patch could
-move the capability-related fields from the kernel data structures into
-the new security fields managed by the security modules. However, at
-present, the LSM kernel patch leaves the capability fields in the kernel
-data structures. In his original remarks, Linus suggested that this
-might be preferable so that other security modules can be easily stacked
-with the capabilities module without needing to chain multiple security
-structures on the security field. It also avoids imposing extra overhead
-on the capabilities module to manage the security fields. However, the
-LSM framework could certainly support such a move if it is determined to
-be desirable, with only a few additional changes described below.
-
-At present, the capabilities logic for computing process capabilities on
-:c:func:`execve()` and :c:func:`set\*uid()`, checking
-capabilities for a particular process, saving and checking capabilities
-for netlink messages, and handling the :c:func:`capget()` and
-:c:func:`capset()` system calls have been moved into the
-capabilities module. There are still a few locations in the base kernel
-where capability-related fields are directly examined or modified, but
-the current version of the LSM patch does allow a security module to
-completely replace the assignment and testing of capabilities. These few
-locations would need to be changed if the capability-related fields were
-moved into the security field. The following is a list of known
-locations that still perform such direct examination or modification of
-capability-related fields:
-
-- ``fs/open.c``::c:func:`sys_access()`
-
-- ``fs/lockd/host.c``::c:func:`nlm_bind_host()`
-
-- ``fs/nfsd/auth.c``::c:func:`nfsd_setuser()`
-
-- ``fs/proc/array.c``::c:func:`task_cap()`
+The POSIX.1e capabilities logic is maintained as a security module
+stored in the file ``security/commoncap.c``. The capabilities
+module uses the order field of the :c:type:`lsm_info` description
+to identify it as the first security module to be registered.
+The capabilities security module does not use the general security
+blobs, unlike other modules. The reasons are historical and are
+based on overhead, complexity and performance concerns.
diff --git a/Documentation/sphinx/requirements.txt b/Documentation/sphinx/requirements.txt
index 14e29a0..489f662 100644
--- a/Documentation/sphinx/requirements.txt
+++ b/Documentation/sphinx/requirements.txt
@@ -1,3 +1,3 @@
docutils
-Sphinx==1.7.9
+Sphinx==2.4.4
sphinx_rtd_theme
diff --git a/Documentation/trace/coresight/coresight-ect.rst b/Documentation/trace/coresight/coresight-ect.rst
index ecc1e57..a93e52a 100644
--- a/Documentation/trace/coresight/coresight-ect.rst
+++ b/Documentation/trace/coresight/coresight-ect.rst
@@ -1,4 +1,5 @@
.. SPDX-License-Identifier: GPL-2.0
+
=============================================
CoreSight Embedded Cross Trigger (CTI & CTM).
=============================================
diff --git a/Documentation/trace/events.rst b/Documentation/trace/events.rst
index 4a2ebe0..f792b19 100644
--- a/Documentation/trace/events.rst
+++ b/Documentation/trace/events.rst
@@ -527,8 +527,8 @@
See Documentation/trace/histogram.rst for details and examples.
-6.3 In-kernel trace event API
------------------------------
+7. In-kernel trace event API
+============================
In most cases, the command-line interface to trace events is more than
sufficient. Sometimes, however, applications might find the need for
@@ -560,8 +560,8 @@
- tracing synthetic events from in-kernel code
- the low-level "dynevent_cmd" API
-6.3.1 Dyamically creating synthetic event definitions
------------------------------------------------------
+7.1 Dyamically creating synthetic event definitions
+---------------------------------------------------
There are a couple ways to create a new synthetic event from a kernel
module or other kernel code.
@@ -666,8 +666,8 @@
At this point, the event object is ready to be used for tracing new
events.
-6.3.3 Tracing synthetic events from in-kernel code
---------------------------------------------------
+7.2 Tracing synthetic events from in-kernel code
+------------------------------------------------
To trace a synthetic event, there are several options. The first
option is to trace the event in one call, using synth_event_trace()
@@ -678,8 +678,8 @@
synth_event_add_next_val() or synth_event_add_val() to add the values
piecewise.
-6.3.3.1 Tracing a synthetic event all at once
----------------------------------------------
+7.2.1 Tracing a synthetic event all at once
+-------------------------------------------
To trace a synthetic event all at once, the synth_event_trace() or
synth_event_trace_array() functions can be used.
@@ -780,8 +780,8 @@
ret = synth_event_delete("schedtest");
-6.3.3.1 Tracing a synthetic event piecewise
--------------------------------------------
+7.2.2 Tracing a synthetic event piecewise
+-----------------------------------------
To trace a synthetic using the piecewise method described above, the
synth_event_trace_start() function is used to 'open' the synthetic
@@ -864,8 +864,8 @@
of whether any of the add calls failed (say due to a bad field name
being passed in).
-6.3.4 Dyamically creating kprobe and kretprobe event definitions
-----------------------------------------------------------------
+7.3 Dyamically creating kprobe and kretprobe event definitions
+--------------------------------------------------------------
To create a kprobe or kretprobe trace event from kernel code, the
kprobe_event_gen_cmd_start() or kretprobe_event_gen_cmd_start()
@@ -941,8 +941,8 @@
ret = kprobe_event_delete("gen_kprobe_test");
-6.3.4 The "dynevent_cmd" low-level API
---------------------------------------
+7.4 The "dynevent_cmd" low-level API
+------------------------------------
Both the in-kernel synthetic event and kprobe interfaces are built on
top of a lower-level "dynevent_cmd" interface. This interface is
diff --git a/Documentation/translations/it_IT/doc-guide/kernel-doc.rst b/Documentation/translations/it_IT/doc-guide/kernel-doc.rst
index a4ecd8f..524ad86 100644
--- a/Documentation/translations/it_IT/doc-guide/kernel-doc.rst
+++ b/Documentation/translations/it_IT/doc-guide/kernel-doc.rst
@@ -515,6 +515,22 @@
.. kernel-doc:: drivers/gpu/drm/i915/intel_audio.c
:internal:
+identifiers: *[ function/type ...]*
+ Include la documentazione per ogni *function* e *type* in *source*.
+ Se non vengono esplicitamente specificate le funzioni da includere, allora
+ verranno incluse tutte quelle disponibili in *source*.
+
+ Esempi::
+
+ .. kernel-doc:: lib/bitmap.c
+ :identifiers: bitmap_parselist bitmap_parselist_user
+
+ .. kernel-doc:: lib/idr.c
+ :identifiers:
+
+functions: *[ function ...]*
+ Questo è uno pseudonimo, deprecato, per la direttiva 'identifiers'.
+
doc: *title*
Include la documentazione del paragrafo ``DOC:`` identificato dal titolo
(*title*) all'interno del file sorgente (*source*). Gli spazi in *title* sono
@@ -528,15 +544,6 @@
.. kernel-doc:: drivers/gpu/drm/i915/intel_audio.c
:doc: High Definition Audio over HDMI and Display Port
-functions: *function* *[...]*
- Dal file sorgente (*source*) include la documentazione per le funzioni
- elencate (*function*).
-
- Esempio::
-
- .. kernel-doc:: lib/bitmap.c
- :functions: bitmap_parselist bitmap_parselist_user
-
Senza alcuna opzione, la direttiva kernel-doc include tutti i commenti di
documentazione presenti nel file sorgente (*source*).
diff --git a/Documentation/translations/it_IT/kernel-hacking/hacking.rst b/Documentation/translations/it_IT/kernel-hacking/hacking.rst
index 24c5928..6aab27a 100644
--- a/Documentation/translations/it_IT/kernel-hacking/hacking.rst
+++ b/Documentation/translations/it_IT/kernel-hacking/hacking.rst
@@ -627,6 +627,24 @@
:c:func:`EXPORT_SYMBOL_GPL()` quando si aggiungono nuove funzionalità o
interfacce.
+:c:func:`EXPORT_SYMBOL_NS()`
+----------------------------
+
+Definita in ``include/linux/export.h``
+
+Questa è una variate di `EXPORT_SYMBOL()` che permette di specificare uno
+spazio dei nomi. Lo spazio dei nomi è documentato in
+:doc:`../core-api/symbol-namespaces`
+
+:c:func:`EXPORT_SYMBOL_NS_GPL()`
+--------------------------------
+
+Definita in ``include/linux/export.h``
+
+Questa è una variate di `EXPORT_SYMBOL_GPL()` che permette di specificare uno
+spazio dei nomi. Lo spazio dei nomi è documentato in
+:doc:`../core-api/symbol-namespaces`
+
Procedure e convenzioni
=======================
diff --git a/Documentation/translations/it_IT/kernel-hacking/locking.rst b/Documentation/translations/it_IT/kernel-hacking/locking.rst
index b9a6be4..4615df5 100644
--- a/Documentation/translations/it_IT/kernel-hacking/locking.rst
+++ b/Documentation/translations/it_IT/kernel-hacking/locking.rst
@@ -159,17 +159,17 @@
Se avete una struttura dati che verrà utilizzata solo dal contesto utente,
allora, per proteggerla, potete utilizzare un semplice mutex
(``include/linux/mutex.h``). Questo è il caso più semplice: inizializzate il
-mutex; invocate :c:func:`mutex_lock_interruptible()` per trattenerlo e
-:c:func:`mutex_unlock()` per rilasciarlo. C'è anche :c:func:`mutex_lock()`
+mutex; invocate mutex_lock_interruptible() per trattenerlo e
+mutex_unlock() per rilasciarlo. C'è anche mutex_lock()
ma questa dovrebbe essere evitata perché non ritorna in caso di segnali.
Per esempio: ``net/netfilter/nf_sockopt.c`` permette la registrazione
-di nuove chiamate per :c:func:`setsockopt()` e :c:func:`getsockopt()`
-usando la funzione :c:func:`nf_register_sockopt()`. La registrazione e
+di nuove chiamate per setsockopt() e getsockopt()
+usando la funzione nf_register_sockopt(). La registrazione e
la rimozione vengono eseguite solamente quando il modulo viene caricato
o scaricato (e durante l'avvio del sistema, qui non abbiamo concorrenza),
e la lista delle funzioni registrate viene consultata solamente quando
-:c:func:`setsockopt()` o :c:func:`getsockopt()` sono sconosciute al sistema.
+setsockopt() o getsockopt() sono sconosciute al sistema.
In questo caso ``nf_sockopt_mutex`` è perfetto allo scopo, in particolar modo
visto che setsockopt e getsockopt potrebbero dormire.
@@ -179,19 +179,19 @@
Se un softirq condivide dati col contesto utente, avete due problemi.
Primo, il contesto utente corrente potrebbe essere interroto da un softirq,
e secondo, la sezione critica potrebbe essere eseguita da un altro
-processore. Questo è quando :c:func:`spin_lock_bh()`
+processore. Questo è quando spin_lock_bh()
(``include/linux/spinlock.h``) viene utilizzato. Questo disabilita i softirq
-sul processore e trattiene il *lock*. Invece, :c:func:`spin_unlock_bh()` fa
+sul processore e trattiene il *lock*. Invece, spin_unlock_bh() fa
l'opposto. (Il suffisso '_bh' è un residuo storico che fa riferimento al
"Bottom Halves", il vecchio nome delle interruzioni software. In un mondo
perfetto questa funzione si chiamerebbe 'spin_lock_softirq()').
-Da notare che in questo caso potete utilizzare anche :c:func:`spin_lock_irq()`
-o :c:func:`spin_lock_irqsave()`, queste fermano anche le interruzioni hardware:
+Da notare che in questo caso potete utilizzare anche spin_lock_irq()
+o spin_lock_irqsave(), queste fermano anche le interruzioni hardware:
vedere :ref:`Contesto di interruzione hardware <it_hardirq-context>`.
Questo funziona alla perfezione anche sui sistemi monoprocessore: gli spinlock
-svaniscono e questa macro diventa semplicemente :c:func:`local_bh_disable()`
+svaniscono e questa macro diventa semplicemente local_bh_disable()
(``include/linux/interrupt.h``), la quale impedisce ai softirq d'essere
eseguiti.
@@ -224,8 +224,8 @@
~~~~~~~~~~~~~~~~~~~~~~~~
Se un altro tasklet/timer vuole condividere dati col vostro tasklet o timer,
-allora avrete bisogno entrambe di :c:func:`spin_lock()` e
-:c:func:`spin_unlock()`. Qui :c:func:`spin_lock_bh()` è inutile, siete già
+allora avrete bisogno entrambe di spin_lock() e
+spin_unlock(). Qui spin_lock_bh() è inutile, siete già
in un tasklet ed avete la garanzia che nessun altro verrà eseguito sullo
stesso processore.
@@ -243,13 +243,13 @@
fino a questo punto nell'uso dei softirq, probabilmente tenete alla scalabilità
delle prestazioni abbastanza da giustificarne la complessità aggiuntiva.
-Dovete utilizzare :c:func:`spin_lock()` e :c:func:`spin_unlock()` per
+Dovete utilizzare spin_lock() e spin_unlock() per
proteggere i dati condivisi.
Diversi Softirqs
~~~~~~~~~~~~~~~~
-Dovete utilizzare :c:func:`spin_lock()` e :c:func:`spin_unlock()` per
+Dovete utilizzare spin_lock() e spin_unlock() per
proteggere i dati condivisi, che siano timer, tasklet, diversi softirq o
lo stesso o altri softirq: uno qualsiasi di essi potrebbe essere in esecuzione
su un diverso processore.
@@ -270,40 +270,40 @@
avrete due preoccupazioni. Primo, il softirq può essere interrotto da
un'interruzione hardware, e secondo, la sezione critica potrebbe essere
eseguita da un'interruzione hardware su un processore diverso. Questo è il caso
-dove :c:func:`spin_lock_irq()` viene utilizzato. Disabilita le interruzioni
-sul processore che l'esegue, poi trattiene il lock. :c:func:`spin_unlock_irq()`
+dove spin_lock_irq() viene utilizzato. Disabilita le interruzioni
+sul processore che l'esegue, poi trattiene il lock. spin_unlock_irq()
fa l'opposto.
-Il gestore d'interruzione hardware non usa :c:func:`spin_lock_irq()` perché
-i softirq non possono essere eseguiti quando il gestore d'interruzione hardware
-è in esecuzione: per questo si può usare :c:func:`spin_lock()`, che è un po'
+Il gestore d'interruzione hardware non ha bisogno di usare spin_lock_irq()
+perché i softirq non possono essere eseguiti quando il gestore d'interruzione
+hardware è in esecuzione: per questo si può usare spin_lock(), che è un po'
più veloce. L'unica eccezione è quando un altro gestore d'interruzioni
-hardware utilizza lo stesso *lock*: :c:func:`spin_lock_irq()` impedirà a questo
+hardware utilizza lo stesso *lock*: spin_lock_irq() impedirà a questo
secondo gestore di interrompere quello in esecuzione.
Questo funziona alla perfezione anche sui sistemi monoprocessore: gli spinlock
-svaniscono e questa macro diventa semplicemente :c:func:`local_irq_disable()`
+svaniscono e questa macro diventa semplicemente local_irq_disable()
(``include/asm/smp.h``), la quale impedisce a softirq/tasklet/BH d'essere
eseguiti.
-:c:func:`spin_lock_irqsave()` (``include/linux/spinlock.h``) è una variante che
+spin_lock_irqsave() (``include/linux/spinlock.h``) è una variante che
salva lo stato delle interruzioni in una variabile, questa verrà poi passata
-a :c:func:`spin_unlock_irqrestore()`. Questo significa che lo stesso codice
+a spin_unlock_irqrestore(). Questo significa che lo stesso codice
potrà essere utilizzato in un'interruzione hardware (dove le interruzioni sono
già disabilitate) e in un softirq (dove la disabilitazione delle interruzioni
è richiesta).
Da notare che i softirq (e quindi tasklet e timer) sono eseguiti al ritorno
-da un'interruzione hardware, quindi :c:func:`spin_lock_irq()` interrompe
+da un'interruzione hardware, quindi spin_lock_irq() interrompe
anche questi. Tenuto conto di questo si può dire che
-:c:func:`spin_lock_irqsave()` è la funzione di sincronizzazione più generica
+spin_lock_irqsave() è la funzione di sincronizzazione più generica
e potente.
Sincronizzazione fra due gestori d'interruzioni hardware
--------------------------------------------------------
Condividere dati fra due gestori di interruzione hardware è molto raro, ma se
-succede, dovreste usare :c:func:`spin_lock_irqsave()`: è una specificità
+succede, dovreste usare spin_lock_irqsave(): è una specificità
dell'architettura il fatto che tutte le interruzioni vengano interrotte
quando si eseguono di gestori di interruzioni.
@@ -317,11 +317,11 @@
il mutex e dormire (``copy_from_user*(`` o ``kmalloc(x,GFP_KERNEL)``).
- Altrimenti (== i dati possono essere manipolati da un'interruzione) usate
- :c:func:`spin_lock_irqsave()` e :c:func:`spin_unlock_irqrestore()`.
+ spin_lock_irqsave() e spin_unlock_irqrestore().
- Evitate di trattenere uno spinlock per più di 5 righe di codice incluse
le chiamate a funzione (ad eccezione di quell per l'accesso come
- :c:func:`readb()`).
+ readb()).
Tabella dei requisiti minimi
----------------------------
@@ -334,7 +334,7 @@
la sincronizzazione è necessaria).
Ricordatevi il suggerimento qui sopra: potete sempre usare
-:c:func:`spin_lock_irqsave()`, che è un sovrainsieme di tutte le altre funzioni
+spin_lock_irqsave(), che è un sovrainsieme di tutte le altre funzioni
per spinlock.
============== ============= ============= ========= ========= ========= ========= ======= ======= ============== ==============
@@ -378,13 +378,13 @@
trattenendo il *lock*. Potrete acquisire il *lock* più tardi se vi
serve accedere ai dati protetti da questo *lock*.
-La funzione :c:func:`spin_trylock()` non ritenta di acquisire il *lock*,
+La funzione spin_trylock() non ritenta di acquisire il *lock*,
se ci riesce al primo colpo ritorna un valore diverso da zero, altrimenti
se fallisce ritorna 0. Questa funzione può essere utilizzata in un qualunque
-contesto, ma come :c:func:`spin_lock()`: dovete disabilitare i contesti che
+contesto, ma come spin_lock(): dovete disabilitare i contesti che
potrebbero interrompervi e quindi trattenere lo spinlock.
-La funzione :c:func:`mutex_trylock()` invece di sospendere il vostro processo
+La funzione mutex_trylock() invece di sospendere il vostro processo
ritorna un valore diverso da zero se è possibile trattenere il lock al primo
colpo, altrimenti se fallisce ritorna 0. Nonostante non dorma, questa funzione
non può essere usata in modo sicuro in contesti di interruzione hardware o
@@ -506,7 +506,7 @@
caso è semplice dato che copiamo i dati dall'utente e non permettiamo
mai loro di accedere direttamente agli oggetti.
-C'è una piccola ottimizzazione qui: nella funzione :c:func:`cache_add()`
+C'è una piccola ottimizzazione qui: nella funzione cache_add()
impostiamo i campi dell'oggetto prima di acquisire il *lock*. Questo è
sicuro perché nessun altro potrà accedervi finché non lo inseriremo
nella memoria.
@@ -514,7 +514,7 @@
Accesso dal contesto utente
---------------------------
-Ora consideriamo il caso in cui :c:func:`cache_find()` può essere invocata
+Ora consideriamo il caso in cui cache_find() può essere invocata
dal contesto d'interruzione: sia hardware che software. Un esempio potrebbe
essere un timer che elimina oggetti dalla memoria.
@@ -583,15 +583,15 @@
return ret;
}
-Da notare che :c:func:`spin_lock_irqsave()` disabiliterà le interruzioni
+Da notare che spin_lock_irqsave() disabiliterà le interruzioni
se erano attive, altrimenti non farà niente (quando siamo già in un contesto
d'interruzione); dunque queste funzioni possono essere chiamante in
sicurezza da qualsiasi contesto.
-Sfortunatamente, :c:func:`cache_add()` invoca :c:func:`kmalloc()` con
+Sfortunatamente, cache_add() invoca kmalloc() con
l'opzione ``GFP_KERNEL`` che è permessa solo in contesto utente. Ho supposto
-che :c:func:`cache_add()` venga chiamata dal contesto utente, altrimenti
-questa opzione deve diventare un parametro di :c:func:`cache_add()`.
+che cache_add() venga chiamata dal contesto utente, altrimenti
+questa opzione deve diventare un parametro di cache_add().
Esporre gli oggetti al di fuori del file
----------------------------------------
@@ -610,7 +610,7 @@
mantiene un puntatore ad un oggetto, presumibilmente si aspetta che questo
puntatore rimanga valido. Sfortunatamente, questo è garantito solo mentre
si trattiene il *lock*, altrimenti qualcuno potrebbe chiamare
-:c:func:`cache_delete()` o peggio, aggiungere un oggetto che riutilizza lo
+cache_delete() o peggio, aggiungere un oggetto che riutilizza lo
stesso indirizzo.
Dato che c'è un solo *lock*, non potete trattenerlo a vita: altrimenti
@@ -710,9 +710,9 @@
}
Abbiamo incapsulato il contatore di riferimenti nelle tipiche funzioni
-di 'get' e 'put'. Ora possiamo ritornare l'oggetto da :c:func:`cache_find()`
+di 'get' e 'put'. Ora possiamo ritornare l'oggetto da cache_find()
col vantaggio che l'utente può dormire trattenendo l'oggetto (per esempio,
-:c:func:`copy_to_user()` per copiare il nome verso lo spazio utente).
+copy_to_user() per copiare il nome verso lo spazio utente).
Un altro punto da notare è che ho detto che il contatore dovrebbe incrementarsi
per ogni puntatore ad un oggetto: quindi il contatore di riferimenti è 1
@@ -727,8 +727,8 @@
in ``include/asm/atomic.h``: queste sono garantite come atomiche su qualsiasi
processore del sistema, quindi non sono necessari i *lock*. In questo caso è
più semplice rispetto all'uso degli spinlock, benché l'uso degli spinlock
-sia più elegante per casi non banali. Le funzioni :c:func:`atomic_inc()` e
-:c:func:`atomic_dec_and_test()` vengono usate al posto dei tipici operatori di
+sia più elegante per casi non banali. Le funzioni atomic_inc() e
+atomic_dec_and_test() vengono usate al posto dei tipici operatori di
incremento e decremento, e i *lock* non sono più necessari per proteggere il
contatore stesso.
@@ -820,7 +820,7 @@
- Si può togliere static da ``cache_lock`` e dire agli utenti che devono
trattenere il *lock* prima di modificare il nome di un oggetto.
-- Si può fornire una funzione :c:func:`cache_obj_rename()` che prende il
+- Si può fornire una funzione cache_obj_rename() che prende il
*lock* e cambia il nome per conto del chiamante; si dirà poi agli utenti
di usare questa funzione.
@@ -878,11 +878,11 @@
protetto da ``cache_lock`` piuttosto che dal *lock* dell'oggetto; questo
perché è logicamente parte dell'infrastruttura (come
:c:type:`struct list_head <list_head>` nell'oggetto). In questo modo,
-in :c:func:`__cache_add()`, non ho bisogno di trattenere il *lock* di ogni
+in __cache_add(), non ho bisogno di trattenere il *lock* di ogni
oggetto mentre si cerca il meno popolare.
Ho anche deciso che il campo id è immutabile, quindi non ho bisogno di
-trattenere il lock dell'oggetto quando si usa :c:func:`__cache_find()`
+trattenere il lock dell'oggetto quando si usa __cache_find()
per leggere questo campo; il *lock* dell'oggetto è usato solo dal chiamante
che vuole leggere o scrivere il campo name.
@@ -907,7 +907,7 @@
sveglio 5 notti a parlare da solo.
Un caso un pochino più complesso; immaginate d'avere una spazio condiviso
-fra un softirq ed il contesto utente. Se usate :c:func:`spin_lock()` per
+fra un softirq ed il contesto utente. Se usate spin_lock() per
proteggerlo, il contesto utente potrebbe essere interrotto da un softirq
mentre trattiene il lock, da qui il softirq rimarrà in attesa attiva provando
ad acquisire il *lock* già trattenuto nel contesto utente.
@@ -1006,12 +1006,12 @@
spin_unlock_bh(&list_lock);
Primo o poi, questo esploderà su un sistema multiprocessore perché un
-temporizzatore potrebbe essere già partiro prima di :c:func:`spin_lock_bh()`,
-e prenderà il *lock* solo dopo :c:func:`spin_unlock_bh()`, e cercherà
+temporizzatore potrebbe essere già partiro prima di spin_lock_bh(),
+e prenderà il *lock* solo dopo spin_unlock_bh(), e cercherà
di eliminare il suo oggetto (che però è già stato eliminato).
Questo può essere evitato controllando il valore di ritorno di
-:c:func:`del_timer()`: se ritorna 1, il temporizzatore è stato già
+del_timer(): se ritorna 1, il temporizzatore è stato già
rimosso. Se 0, significa (in questo caso) che il temporizzatore è in
esecuzione, quindi possiamo fare come segue::
@@ -1032,9 +1032,9 @@
spin_unlock_bh(&list_lock);
Un altro problema è l'eliminazione dei temporizzatori che si riavviano
-da soli (chiamando :c:func:`add_timer()` alla fine della loro esecuzione).
+da soli (chiamando add_timer() alla fine della loro esecuzione).
Dato che questo è un problema abbastanza comune con una propensione
-alle corse critiche, dovreste usare :c:func:`del_timer_sync()`
+alle corse critiche, dovreste usare del_timer_sync()
(``include/linux/timer.h``) per gestire questo caso. Questa ritorna il
numero di volte che il temporizzatore è stato interrotto prima che
fosse in grado di fermarlo senza che si riavviasse.
@@ -1116,7 +1116,7 @@
wmb();
list->next = new;
-La funzione :c:func:`wmb()` è una barriera di sincronizzazione delle
+La funzione wmb() è una barriera di sincronizzazione delle
scritture. Questa garantisce che la prima operazione (impostare l'elemento
``next`` del nuovo elemento) venga completata e vista da tutti i processori
prima che venga eseguita la seconda operazione (che sarebbe quella di mettere
@@ -1127,7 +1127,7 @@
il puntatore ``next`` deve puntare al resto della lista.
Fortunatamente, c'è una funzione che fa questa operazione sulle liste
-:c:type:`struct list_head <list_head>`: :c:func:`list_add_rcu()`
+:c:type:`struct list_head <list_head>`: list_add_rcu()
(``include/linux/list.h``).
Rimuovere un elemento dalla lista è anche più facile: sostituiamo il puntatore
@@ -1138,7 +1138,7 @@
list->next = old->next;
-La funzione :c:func:`list_del_rcu()` (``include/linux/list.h``) fa esattamente
+La funzione list_del_rcu() (``include/linux/list.h``) fa esattamente
questo (la versione normale corrompe il vecchio oggetto, e non vogliamo che
accada).
@@ -1146,9 +1146,9 @@
attraverso il puntatore ``next`` il contenuto dell'elemento successivo
troppo presto, ma non accorgersi che il contenuto caricato è sbagliato quando
il puntatore ``next`` viene modificato alla loro spalle. Ancora una volta
-c'è una funzione che viene in vostro aiuto :c:func:`list_for_each_entry_rcu()`
+c'è una funzione che viene in vostro aiuto list_for_each_entry_rcu()
(``include/linux/list.h``). Ovviamente, gli scrittori possono usare
-:c:func:`list_for_each_entry()` dato che non ci possono essere due scrittori
+list_for_each_entry() dato che non ci possono essere due scrittori
in contemporanea.
Il nostro ultimo dilemma è il seguente: quando possiamo realmente distruggere
@@ -1156,15 +1156,15 @@
elemento proprio ora: se eliminiamo questo elemento ed il puntatore ``next``
cambia, il lettore salterà direttamente nella spazzatura e scoppierà. Dobbiamo
aspettare finché tutti i lettori che stanno attraversando la lista abbiano
-finito. Utilizziamo :c:func:`call_rcu()` per registrare una funzione di
+finito. Utilizziamo call_rcu() per registrare una funzione di
richiamo che distrugga l'oggetto quando tutti i lettori correnti hanno
terminato. In alternative, potrebbe essere usata la funzione
-:c:func:`synchronize_rcu()` che blocca l'esecuzione finché tutti i lettori
+synchronize_rcu() che blocca l'esecuzione finché tutti i lettori
non terminano di ispezionare la lista.
Ma come fa l'RCU a sapere quando i lettori sono finiti? Il meccanismo è
il seguente: innanzi tutto i lettori accedono alla lista solo fra la coppia
-:c:func:`rcu_read_lock()`/:c:func:`rcu_read_unlock()` che disabilita la
+rcu_read_lock()/rcu_read_unlock() che disabilita la
prelazione così che i lettori non vengano sospesi mentre stanno leggendo
la lista.
@@ -1253,12 +1253,12 @@
}
Da notare che i lettori modificano il campo popularity nella funzione
-:c:func:`__cache_find()`, e ora non trattiene alcun *lock*. Una soluzione
+__cache_find(), e ora non trattiene alcun *lock*. Una soluzione
potrebbe essere quella di rendere la variabile ``atomic_t``, ma per l'uso
che ne abbiamo fatto qui, non ci interessano queste corse critiche perché un
risultato approssimativo è comunque accettabile, quindi non l'ho cambiato.
-Il risultato è che la funzione :c:func:`cache_find()` non ha bisogno di alcuna
+Il risultato è che la funzione cache_find() non ha bisogno di alcuna
sincronizzazione con le altre funzioni, quindi è veloce su un sistema
multi-processore tanto quanto lo sarebbe su un sistema mono-processore.
@@ -1271,9 +1271,9 @@
Ora, dato che il '*lock* di lettura' di un RCU non fa altro che disabilitare
la prelazione, un chiamante che ha sempre la prelazione disabilitata fra le
-chiamate :c:func:`cache_find()` e :c:func:`object_put()` non necessita
+chiamate cache_find() e object_put() non necessita
di incrementare e decrementare il contatore di riferimenti. Potremmo
-esporre la funzione :c:func:`__cache_find()` dichiarandola non-static,
+esporre la funzione __cache_find() dichiarandola non-static,
e quel chiamante potrebbe usare direttamente questa funzione.
Il beneficio qui sta nel fatto che il contatore di riferimenti no
@@ -1293,10 +1293,10 @@
Se questo dovesse essere troppo lento (solitamente non lo è, ma se avete
dimostrato che lo è devvero), potreste usare un contatore per ogni processore
e quindi non sarebbe più necessaria la mutua esclusione. Vedere
-:c:func:`DEFINE_PER_CPU()`, :c:func:`get_cpu_var()` e :c:func:`put_cpu_var()`
+DEFINE_PER_CPU(), get_cpu_var() e put_cpu_var()
(``include/linux/percpu.h``).
-Il tipo di dato ``local_t``, la funzione :c:func:`cpu_local_inc()` e tutte
+Il tipo di dato ``local_t``, la funzione cpu_local_inc() e tutte
le altre funzioni associate, sono di particolare utilità per semplici contatori
per-processore; su alcune architetture sono anche più efficienti
(``include/asm/local.h``).
@@ -1324,11 +1324,11 @@
enable_irq(irq);
spin_unlock(&lock);
-La funzione :c:func:`disable_irq()` impedisce al gestore d'interruzioni
+La funzione disable_irq() impedisce al gestore d'interruzioni
d'essere eseguito (e aspetta che finisca nel caso fosse in esecuzione su
un altro processore). Lo spinlock, invece, previene accessi simultanei.
Naturalmente, questo è più lento della semplice chiamata
-:c:func:`spin_lock_irq()`, quindi ha senso solo se questo genere di accesso
+spin_lock_irq(), quindi ha senso solo se questo genere di accesso
è estremamente raro.
.. _`it_sleeping-things`:
@@ -1336,7 +1336,7 @@
Quali funzioni possono essere chiamate in modo sicuro dalle interruzioni?
=========================================================================
-Molte funzioni del kernel dormono (in sostanza, chiamano ``schedule()``)
+Molte funzioni del kernel dormono (in sostanza, chiamano schedule())
direttamente od indirettamente: non potete chiamarle se trattenere uno
spinlock o avete la prelazione disabilitata, mai. Questo significa che
dovete necessariamente essere nel contesto utente: chiamarle da un
@@ -1354,23 +1354,23 @@
- Accessi allo spazio utente:
- - :c:func:`copy_from_user()`
+ - copy_from_user()
- - :c:func:`copy_to_user()`
+ - copy_to_user()
- - :c:func:`get_user()`
+ - get_user()
- - :c:func:`put_user()`
+ - put_user()
-- :c:func:`kmalloc(GFP_KERNEL) <kmalloc>`
+- kmalloc(GFP_KERNEL) <kmalloc>`
-- :c:func:`mutex_lock_interruptible()` and
- :c:func:`mutex_lock()`
+- mutex_lock_interruptible() and
+ mutex_lock()
- C'è anche :c:func:`mutex_trylock()` che però non dorme.
+ C'è anche mutex_trylock() che però non dorme.
Comunque, non deve essere usata in un contesto d'interruzione dato
che la sua implementazione non è sicura in quel contesto.
- Anche :c:func:`mutex_unlock()` non dorme mai. Non può comunque essere
+ Anche mutex_unlock() non dorme mai. Non può comunque essere
usata in un contesto d'interruzione perché un mutex deve essere rilasciato
dallo stesso processo che l'ha acquisito.
@@ -1380,11 +1380,11 @@
Alcune funzioni possono essere chiamate tranquillamente da qualsiasi
contesto, o trattenendo un qualsiasi *lock*.
-- :c:func:`printk()`
+- printk()
-- :c:func:`kfree()`
+- kfree()
-- :c:func:`add_timer()` e :c:func:`del_timer()`
+- add_timer() e del_timer()
Riferimento per l'API dei Mutex
===============================
@@ -1444,14 +1444,14 @@
bh
Bottom Half: per ragioni storiche, le funzioni che contengono '_bh' nel
loro nome ora si riferiscono a qualsiasi interruzione software; per esempio,
- :c:func:`spin_lock_bh()` blocca qualsiasi interuzione software sul processore
+ spin_lock_bh() blocca qualsiasi interuzione software sul processore
corrente. I *Bottom Halves* sono deprecati, e probabilmente verranno
sostituiti dai tasklet. In un dato momento potrà esserci solo un
*bottom half* in esecuzione.
contesto d'interruzione
Non è il contesto utente: qui si processano le interruzioni hardware e
- software. La macro :c:func:`in_interrupt()` ritorna vero.
+ software. La macro in_interrupt() ritorna vero.
contesto utente
Il kernel che esegue qualcosa per conto di un particolare processo (per
@@ -1461,12 +1461,12 @@
che hardware.
interruzione hardware
- Richiesta di interruzione hardware. :c:func:`in_irq()` ritorna vero in un
+ Richiesta di interruzione hardware. in_irq() ritorna vero in un
gestore d'interruzioni hardware.
interruzione software / softirq
- Gestore di interruzioni software: :c:func:`in_irq()` ritorna falso;
- :c:func:`in_softirq()` ritorna vero. I tasklet e le softirq sono entrambi
+ Gestore di interruzioni software: in_irq() ritorna falso;
+ in_softirq() ritorna vero. I tasklet e le softirq sono entrambi
considerati 'interruzioni software'.
In soldoni, un softirq è uno delle 32 interruzioni software che possono
diff --git a/Documentation/translations/it_IT/process/2.Process.rst b/Documentation/translations/it_IT/process/2.Process.rst
index 9af4d01..30dc172 100644
--- a/Documentation/translations/it_IT/process/2.Process.rst
+++ b/Documentation/translations/it_IT/process/2.Process.rst
@@ -23,18 +23,18 @@
I rilasci più recenti sono stati:
====== =================
- 4.11 Aprile 30, 2017
- 4.12 Luglio 2, 2017
- 4.13 Settembre 3, 2017
- 4.14 Novembre 12, 2017
- 4.15 Gennaio 28, 2018
- 4.16 Aprile 1, 2018
+ 5.0 3 marzo, 2019
+ 5.1 5 maggio, 2019
+ 5.2 7 luglio, 2019
+ 5.3 15 settembre, 2019
+ 5.4 24 novembre, 2019
+ 5.5 6 gennaio, 2020
====== =================
-Ciascun rilascio 4.x è un importante rilascio del kernel con nuove
+Ciascun rilascio 5.x è un importante rilascio del kernel con nuove
funzionalità, modifiche interne dell'API, e molto altro. Un tipico
-rilascio 4.x contiene quasi 13,000 gruppi di modifiche con ulteriori
-modifiche a parecchie migliaia di linee di codice. La 4.x. è pertanto la
+rilascio contiene quasi 13,000 gruppi di modifiche con ulteriori
+modifiche a parecchie migliaia di linee di codice. La 5.x. è pertanto la
linea di confine nello sviluppo del kernel Linux; il kernel utilizza un sistema
di sviluppo continuo che integra costantemente nuove importanti modifiche.
@@ -55,8 +55,8 @@
La finestra di inclusione resta attiva approssimativamente per due settimane.
Al termine di questo periodo, Linus Torvald dichiarerà che la finestra è
chiusa e rilascerà il primo degli "rc" del kernel.
-Per il kernel che è destinato ad essere 2.6.40, per esempio, il rilascio
-che emerge al termine della finestra d'inclusione si chiamerà 2.6.40-rc1.
+Per il kernel che è destinato ad essere 5.6, per esempio, il rilascio
+che emerge al termine della finestra d'inclusione si chiamerà 5.6-rc1.
Questo rilascio indica che il momento di aggiungere nuovi componenti è
passato, e che è iniziato il periodo di stabilizzazione del prossimo kernel.
@@ -76,22 +76,23 @@
il ritmo delle modifiche rallenta col tempo. Linus rilascia un nuovo
kernel -rc circa una volta alla settimana; e ne usciranno circa 6 o 9 prima
che il kernel venga considerato sufficientemente stabile e che il rilascio
-finale 2.6.x venga fatto. A quel punto tutto il processo ricomincerà.
+finale venga fatto. A quel punto tutto il processo ricomincerà.
-Esempio: ecco com'è andato il ciclo di sviluppo della versione 4.16
+Esempio: ecco com'è andato il ciclo di sviluppo della versione 5.4
(tutte le date si collocano nel 2018)
============== =======================================
- Gennaio 28 4.15 rilascio stabile
- Febbraio 11 4.16-rc1, finestra di inclusione chiusa
- Febbraio 18 4.16-rc2
- Febbraio 25 4.16-rc3
- Marzo 4 4.16-rc4
- Marzo 11 4.16-rc5
- Marzo 18 4.16-rc6
- Marzo 25 4.16-rc7
- Aprile 1 4.17 rilascio stabile
+ 15 settembre 5.3 rilascio stabile
+ 30 settembre 5.4-rc1, finestra di inclusione chiusa
+ 6 ottobre 5.4-rc2
+ 13 ottobre 5.4-rc3
+ 20 ottobre 5.4-rc4
+ 27 ottobre 5.4-rc5
+ 3 novembre 5.4-rc6
+ 10 novembre 5.4-rc7
+ 17 novembre 5.4-rc8
+ 24 novembre 5.4 rilascio stabile
============== =======================================
In che modo gli sviluppatori decidono quando chiudere il ciclo di sviluppo e
@@ -108,43 +109,44 @@
in un progetto di questa portata. Arriva un punto dove ritardare il rilascio
finale peggiora la situazione; la quantità di modifiche in attesa della
prossima finestra di inclusione crescerà enormemente, creando ancor più
-regressioni al giro successivo. Quindi molti kernel 4.x escono con una
+regressioni al giro successivo. Quindi molti kernel 5.x escono con una
manciata di regressioni delle quali, si spera, nessuna è grave.
Una volta che un rilascio stabile è fatto, il suo costante mantenimento è
affidato al "squadra stabilità", attualmente composta da Greg Kroah-Hartman.
Questa squadra rilascia occasionalmente degli aggiornamenti relativi al
-rilascio stabile usando la numerazione 4.x.y. Per essere presa in
+rilascio stabile usando la numerazione 5.x.y. Per essere presa in
considerazione per un rilascio d'aggiornamento, una modifica deve:
(1) correggere un baco importante (2) essere già inserita nel ramo principale
per il prossimo sviluppo del kernel. Solitamente, passato il loro rilascio
iniziale, i kernel ricevono aggiornamenti per più di un ciclo di sviluppo.
-Quindi, per esempio, la storia del kernel 4.13 appare così:
+Quindi, per esempio, la storia del kernel 5.2 appare così (anno 2019):
============== ===============================
- Settembre 3 4.13 rilascio stabile
- Settembre 13 4.13.1
- Settembre 20 4.13.2
- Settembre 27 4.13.3
- Ottobre 5 4.13.4
- Ottobre 12 4.13.5
+ 15 settembre 5.2 rilascio stabile FIXME settembre è sbagliato
+ 14 luglio 5.2.1
+ 21 luglio 5.2.2
+ 26 luglio 5.2.3
+ 28 luglio 5.2.4
+ 31 luglio 5.2.5
... ...
- Novembre 24 4.13.16
+ 11 ottobre 5.2.21
============== ===============================
-La 4.13.16 fu l'aggiornamento finale per la versione 4.13.
+La 5.2.21 fu l'aggiornamento finale per la versione 5.2.
Alcuni kernel sono destinati ad essere kernel a "lungo termine"; questi
riceveranno assistenza per un lungo periodo di tempo. Al momento in cui
scriviamo, i manutentori dei kernel stabili a lungo termine sono:
- ====== ====================== ==========================================
- 3.16 Ben Hutchings (kernel stabile molto più a lungo termine)
- 4.1 Sasha Levin
- 4.4 Greg Kroah-Hartman (kernel stabile molto più a lungo termine)
- 4.9 Greg Kroah-Hartman
- 4.14 Greg Kroah-Hartman
- ====== ====================== ==========================================
+ ====== ================================ ==========================================
+ 3.16 Ben Hutchings (kernel stabile molto più a lungo termine)
+ 4.4 Greg Kroah-Hartman e Sasha Levin (kernel stabile molto più a lungo termine)
+ 4.9 Greg Kroah-Hartman e Sasha Levin
+ 4.14 Greg Kroah-Hartman e Sasha Levin
+ 4.19 Greg Kroah-Hartman e Sasha Levin
+ 5.4i Greg Kroah-Hartman e Sasha Levin
+ ====== ================================ ==========================================
Questa selezione di kernel di lungo periodo sono puramente dovuti ai loro
@@ -229,12 +231,13 @@
--------------------------------------
Esiste una sola persona che può inserire le patch nel repositorio principale
-del kernel: Linus Torvalds. Ma, di tutte le 9500 patch che entrarono nella
-versione 2.6.38 del kernel, solo 112 (circa l'1,3%) furono scelte direttamente
-da Linus in persona. Il progetto del kernel è cresciuto fino a raggiungere
-una dimensione tale per cui un singolo sviluppatore non può controllare e
-selezionare indipendentemente ogni modifica senza essere supportato.
-La via scelta dagli sviluppatori per indirizzare tale crescita è stata quella
+del kernel: Linus Torvalds. Ma, per esempio, di tutte le 9500 patch
+che entrarono nella versione 2.6.38 del kernel, solo 112 (circa
+l'1,3%) furono scelte direttamente da Linus in persona. Il progetto
+del kernel è cresciuto fino a raggiungere una dimensione tale per cui
+un singolo sviluppatore non può controllare e selezionare
+indipendentemente ogni modifica senza essere supportato. La via
+scelta dagli sviluppatori per indirizzare tale crescita è stata quella
di utilizzare un sistema di "sottotenenti" basato sulla fiducia.
Il codice base del kernel è spezzato in una serie si sottosistemi: rete,
diff --git a/Documentation/translations/it_IT/process/adding-syscalls.rst b/Documentation/translations/it_IT/process/adding-syscalls.rst
index c3a3439..bff0a82 100644
--- a/Documentation/translations/it_IT/process/adding-syscalls.rst
+++ b/Documentation/translations/it_IT/process/adding-syscalls.rst
@@ -39,7 +39,7 @@
un qualche modo opaca.
- Se dovete esporre solo delle informazioni sul sistema, un nuovo nodo in
- sysfs (vedere ``Documentation/filesystems/sysfs.txt``) o
+ sysfs (vedere ``Documentation/filesystems/sysfs.rst``) o
in procfs potrebbe essere sufficiente. Tuttavia, l'accesso a questi
meccanismi richiede che il filesystem sia montato, il che potrebbe non
essere sempre vero (per esempio, in ambienti come namespace/sandbox/chroot).
diff --git a/Documentation/translations/it_IT/process/coding-style.rst b/Documentation/translations/it_IT/process/coding-style.rst
index 8725f2b..6f4f858 100644
--- a/Documentation/translations/it_IT/process/coding-style.rst
+++ b/Documentation/translations/it_IT/process/coding-style.rst
@@ -313,7 +313,7 @@
qualcosa di simile, **non** dovreste chiamarla ``cntusr()``.
Codificare il tipo di funzione nel suo nome (quella cosa chiamata notazione
-ungherese) fa male al cervello - il compilatore conosce comunque il tipo e
+ungherese) è stupido - il compilatore conosce comunque il tipo e
può verificarli, e inoltre confonde i programmatori. Non c'è da
sorprendersi che MicroSoft faccia programmi bacati.
@@ -825,8 +825,8 @@
Agli sviluppatori del kernel piace essere visti come dotti. Tenete un occhio
di riguardo per l'ortografia e farete una belle figura. In inglese, evitate
-l'uso di parole mozzate come ``dont``: usate ``do not`` oppure ``don't``.
-Scrivete messaggi concisi, chiari, e inequivocabili.
+l'uso incorretto di abbreviazioni come ``dont``: usate ``do not`` oppure
+``don't``. Scrivete messaggi concisi, chiari, e inequivocabili.
I messaggi del kernel non devono terminare con un punto fermo.
diff --git a/Documentation/translations/it_IT/process/deprecated.rst b/Documentation/translations/it_IT/process/deprecated.rst
index 776f267..e108eaf 100644
--- a/Documentation/translations/it_IT/process/deprecated.rst
+++ b/Documentation/translations/it_IT/process/deprecated.rst
@@ -34,6 +34,33 @@
deve essere rimossa dal kernel, o aggiunta a questo documento per scoraggiarne
l'uso.
+BUG() e BUG_ON()
+----------------
+Al loro posto usate WARN() e WARN_ON() per gestire le
+condizioni "impossibili" e gestitele come se fosse possibile farlo.
+Nonostante le funzioni della famiglia BUG() siano state progettate
+per asserire "situazioni impossibili" e interrompere in sicurezza un
+thread del kernel, queste si sono rivelate essere troppo rischiose
+(per esempio, in quale ordine rilasciare i *lock*? Ci sono stati che
+sono stati ripristinati?). Molto spesso l'uso di BUG()
+destabilizza il sistema o lo corrompe del tutto, il che rende
+impossibile un'attività di debug o anche solo leggere un rapporto
+circa l'errore. Linus ha un'opinione molto critica al riguardo:
+`email 1
+<https://lore.kernel.org/lkml/CA+55aFy6jNLsywVYdGp83AMrXBo_P-pkjkphPGrO=82SPKCpLQ@mail.gmail.com/>`_,
+`email 2
+<https://lore.kernel.org/lkml/CAHk-=whDHsbK3HTOpTF=ue_o04onRwTEaK_ZoJp_fjbqq4+=Jw@mail.gmail.com/>`_
+
+Tenete presente che la famiglia di funzioni WARN() dovrebbe essere
+usato solo per situazioni che si suppone siano "impossibili". Se
+volete avvisare gli utenti riguardo a qualcosa di possibile anche se
+indesiderato, usare le funzioni della famiglia pr_warn(). Chi
+amministra il sistema potrebbe aver attivato l'opzione sysctl
+*panic_on_warn* per essere sicuri che il sistema smetta di funzionare
+in caso si verifichino delle condizioni "inaspettate". (per esempio,
+date un'occhiata al questo `commit
+<https://git.kernel.org/linus/d4689846881d160a4d12a514e991a740bcb5d65a>`_)
+
Calcoli codificati negli argomenti di un allocatore
----------------------------------------------------
Il calcolo dinamico delle dimensioni (specialmente le moltiplicazioni) non
@@ -68,52 +95,81 @@
header = kzalloc(struct_size(header, item, count), GFP_KERNEL);
-Per maggiori dettagli fate riferimento a :c:func:`array_size`,
-:c:func:`array3_size`, e :c:func:`struct_size`, così come la famiglia di
-funzioni :c:func:`check_add_overflow` e :c:func:`check_mul_overflow`.
+Per maggiori dettagli fate riferimento a array_size(),
+array3_size(), e struct_size(), così come la famiglia di
+funzioni check_add_overflow() e check_mul_overflow().
simple_strtol(), simple_strtoll(), simple_strtoul(), simple_strtoull()
----------------------------------------------------------------------
-Le funzioni :c:func:`simple_strtol`, :c:func:`simple_strtoll`,
-:c:func:`simple_strtoul`, e :c:func:`simple_strtoull` ignorano volutamente
+Le funzioni simple_strtol(), simple_strtoll(),
+simple_strtoul(), e simple_strtoull() ignorano volutamente
i possibili overflow, e questo può portare il chiamante a generare risultati
-inaspettati. Le rispettive funzioni :c:func:`kstrtol`, :c:func:`kstrtoll`,
-:c:func:`kstrtoul`, e :c:func:`kstrtoull` sono da considerarsi le corrette
+inaspettati. Le rispettive funzioni kstrtol(), kstrtoll(),
+kstrtoul(), e kstrtoull() sono da considerarsi le corrette
sostitute; tuttavia va notato che queste richiedono che la stringa sia
terminata con il carattere NUL o quello di nuova riga.
strcpy()
--------
-La funzione :c:func:`strcpy` non fa controlli agli estremi del buffer
+La funzione strcpy() non fa controlli agli estremi del buffer
di destinazione. Questo può portare ad un overflow oltre i limiti del
buffer e generare svariati tipi di malfunzionamenti. Nonostante l'opzione
`CONFIG_FORTIFY_SOURCE=y` e svariate opzioni del compilatore aiutano
a ridurne il rischio, non c'è alcuna buona ragione per continuare ad usare
-questa funzione. La versione sicura da usare è :c:func:`strscpy`.
+questa funzione. La versione sicura da usare è strscpy().
strncpy() su stringe terminate con NUL
--------------------------------------
-L'utilizzo di :c:func:`strncpy` non fornisce alcuna garanzia sul fatto che
+L'utilizzo di strncpy() non fornisce alcuna garanzia sul fatto che
il buffer di destinazione verrà terminato con il carattere NUL. Questo
potrebbe portare a diversi overflow di lettura o altri malfunzionamenti
causati, appunto, dalla mancanza del terminatore. Questa estende la
terminazione nel buffer di destinazione quando la stringa d'origine è più
corta; questo potrebbe portare ad una penalizzazione delle prestazioni per
chi usa solo stringe terminate. La versione sicura da usare è
-:c:func:`strscpy`. (chi usa :c:func:`strscpy` e necessita di estendere la
-terminazione con NUL deve aggiungere una chiamata a :c:func:`memset`)
+strscpy(). (chi usa strscpy() e necessita di estendere la
+terminazione con NUL deve aggiungere una chiamata a memset())
-Se il chiamate no usa stringhe terminate con NUL, allore :c:func:`strncpy()`
+Se il chiamate no usa stringhe terminate con NUL, allore strncpy()()
può continuare ad essere usata, ma i buffer di destinazione devono essere
marchiati con l'attributo `__nonstring <https://gcc.gnu.org/onlinedocs/gcc/Common-Variable-Attributes.html>`_
per evitare avvisi durante la compilazione.
strlcpy()
---------
-La funzione :c:func:`strlcpy`, per prima cosa, legge interamente il buffer di
+La funzione strlcpy(), per prima cosa, legge interamente il buffer di
origine, magari leggendo più di quanto verrà effettivamente copiato. Questo
è inefficiente e può portare a overflow di lettura quando la stringa non è
-terminata con NUL. La versione sicura da usare è :c:func:`strscpy`.
+terminata con NUL. La versione sicura da usare è strscpy().
+
+Segnaposto %p nella stringa di formato
+--------------------------------------
+
+Tradizionalmente, l'uso del segnaposto "%p" nella stringa di formato
+esponne un indirizzo di memoria in dmesg, proc, sysfs, eccetera. Per
+evitare che questi indirizzi vengano sfruttati da malintenzionati,
+tutto gli usi di "%p" nel kernel rappresentano l'hash dell'indirizzo,
+rendendolo di fatto inutilizzabile. Nuovi usi di "%p" non dovrebbero
+essere aggiunti al kernel. Per una rappresentazione testuale di un
+indirizzo usate "%pS", l'output è migliore perché mostrerà il nome del
+simbolo. Per tutto il resto, semplicemente non usate "%p".
+
+Parafrasando la `guida
+<https://lore.kernel.org/lkml/CA+55aFwQEd_d40g4mUCSsVRZzrFPUJt74vc6PPpb675hYNXcKw@mail.gmail.com/>`_
+di Linus:
+
+- Se il valore hash di "%p" è inutile, chiediti se il puntatore stesso
+ è importante. Forse dovrebbe essere rimosso del tutto?
+- Se credi davvero che il vero valore del puntatore sia importante,
+ perché alcuni stati del sistema o i livelli di privilegi di un
+ utente sono considerati "special"? Se pensi di poterlo giustificare
+ (in un commento e nel messaggio del commit) abbastanza bene da
+ affrontare il giudizio di Linus, allora forse potrai usare "%px",
+ assicurandosi anche di averne il permesso.
+
+Infine, sappi che un cambio in favore di "%p" con hash `non verrà
+accettato
+<https://lore.kernel.org/lkml/CA+55aFwieC1-nAs+NFq9RTwaR8ef9hWa4MjNBWL41F-8wM49eA@mail.gmail.com/>`_.
Vettori a dimensione variabile (VLA)
------------------------------------
@@ -127,3 +183,47 @@
dati importanti alla fine dello stack (quando il kernel è compilato senza
`CONFIG_THREAD_INFO_IN_TASK=y`), o sovrascrivere un pezzo di memoria adiacente
allo stack (quando il kernel è compilato senza `CONFIG_VMAP_STACK=y`).
+
+Salto implicito nell'istruzione switch-case
+-------------------------------------------
+
+Il linguaggio C permette ai casi di un'istruzione `switch` di saltare al
+prossimo caso quando l'istruzione "break" viene omessa alla fine del caso
+corrente. Tuttavia questo rende il codice ambiguo perché non è sempre ovvio se
+l'istruzione "break" viene omessa intenzionalmente o è un baco. Per esempio,
+osservando il seguente pezzo di codice non è chiaro se lo stato
+`STATE_ONE` è stato progettato apposta per eseguire anche `STATE_TWO`::
+
+ switch (value) {
+ case STATE_ONE:
+ do_something();
+ case STATE_TWO:
+ do_other();
+ break;
+ default:
+ WARN("unknown state");
+ }
+
+Dato che c'è stata una lunga lista di problemi `dovuti alla mancanza dell'istruzione
+"break" <https://cwe.mitre.org/data/definitions/484.html>`_, oggigiorno non
+permettiamo più che vi sia un "salto implicito" (*fall-through*). Per
+identificare un salto implicito intenzionale abbiamo adottato la pseudo
+parola chiave 'fallthrough' che viene espansa nell'estensione di gcc
+`__attribute__((fallthrough))` `Statement Attributes
+<https://gcc.gnu.org/onlinedocs/gcc/Statement-Attributes.html>`_.
+(Quando la sintassi C17/C18 `[[fallthrough]]` sarà più comunemente
+supportata dai compilatori C, analizzatori statici, e dagli IDE,
+allora potremo usare quella sintassi per la pseudo parola chiave)
+
+Quando la sintassi [[fallthrough]] sarà più comunemente supportata dai
+compilatori, analizzatori statici, e ambienti di sviluppo IDE,
+allora potremo usarla anche noi.
+
+Ne consegue che tutti i blocchi switch/case devono finire in uno dei seguenti
+modi:
+
+* ``break;``
+* `fallthrough;``
+* ``continue;``
+* ``goto <label>;``
+* ``return [expression];``
diff --git a/Documentation/translations/it_IT/process/email-clients.rst b/Documentation/translations/it_IT/process/email-clients.rst
index 224ab03..89abf6d 100644
--- a/Documentation/translations/it_IT/process/email-clients.rst
+++ b/Documentation/translations/it_IT/process/email-clients.rst
@@ -1,12 +1,334 @@
.. include:: ../disclaimer-ita.rst
-:Original: :ref:`Documentation/process/email-clients.rst <email_clients>`
-
-.. _it_email_clients:
+:Original: :doc:`../../../process/email-clients`
+:Translator: Alessia Mantegazza <amantegazza@vaga.pv.it>
Informazioni sui programmi di posta elettronica per Linux
=========================================================
-.. warning::
+Git
+---
- TODO ancora da tradurre
+Oggigiorno, la maggior parte degli sviluppatori utilizza ``git send-email``
+al posto dei classici programmi di posta elettronica. Le pagine man sono
+abbastanza buone. Dal lato del ricevente, i manutentori utilizzano ``git am``
+per applicare le patch.
+
+Se siete dei novelli utilizzatori di ``git`` allora inviate la patch a voi
+stessi. Salvatela come testo includendo tutte le intestazioni. Poi eseguite
+il comando ``git am messaggio-formato-testo.txt`` e revisionatene il risultato
+con ``git log``. Quando tutto funziona correttamente, allora potete inviare
+la patch alla lista di discussione più appropriata.
+
+Panoramica delle opzioni
+------------------------
+
+Le patch per il kernel vengono inviate per posta elettronica, preferibilmente
+come testo integrante del messaggio. Alcuni manutentori accettano gli
+allegati, ma in questo caso gli allegati devono avere il *content-type*
+impostato come ``text/plain``. Tuttavia, generalmente gli allegati non sono
+ben apprezzati perché rende più difficile citare porzioni di patch durante il
+processo di revisione.
+
+I programmi di posta elettronica che vengono usati per inviare le patch per il
+kernel Linux dovrebbero inviarle senza alterazioni. Per esempio, non
+dovrebbero modificare o rimuovere tabulazioni o spazi, nemmeno all'inizio o
+alla fine delle righe.
+
+Non inviate patch con ``format=flowed``. Questo potrebbe introdurre
+interruzioni di riga inaspettate e indesiderate.
+
+Non lasciate che il vostro programma di posta vada a capo automaticamente.
+Questo può corrompere le patch.
+
+I programmi di posta non dovrebbero modificare la codifica dei caratteri nel
+testo. Le patch inviate per posta elettronica dovrebbero essere codificate in
+ASCII o UTF-8.
+Se configurate il vostro programma per inviare messaggi codificati con UTF-8
+eviterete possibili problemi di codifica.
+
+I programmi di posta dovrebbero generare e mantenere le intestazioni
+"References" o "In-Reply-To:" cosicché la discussione non venga interrotta.
+
+Di solito, il copia-e-incolla (o taglia-e-incolla) non funziona con le patch
+perché le tabulazioni vengono convertite in spazi. Usando xclipboard, xclip
+e/o xcutsel potrebbe funzionare, ma è meglio che lo verifichiate o meglio
+ancora: non usate il copia-e-incolla.
+
+Non usate firme PGP/GPG nei messaggi che contengono delle patch. Questo
+impedisce il corretto funzionamento di alcuni script per leggere o applicare
+patch (questo si dovrebbe poter correggere).
+
+Prima di inviare le patch sulle liste di discussione Linux, può essere una
+buona idea quella di inviare la patch a voi stessi, salvare il messaggio
+ricevuto, e applicarlo ai sorgenti con successo.
+
+
+Alcuni suggerimenti per i programmi di posta elettronica (MUA)
+--------------------------------------------------------------
+
+Qui troverete alcuni suggerimenti per configurare i vostri MUA allo scopo
+di modificare ed inviare patch per il kernel Linux. Tuttavia, questi
+suggerimenti non sono da considerarsi come un riassunto di una configurazione
+completa.
+
+Legenda:
+
+- TUI = interfaccia utente testuale (*text-based user interface*)
+- GUI = interfaccia utente grafica (*graphical user interface*)
+
+Alpine (TUI)
+************
+
+Opzioni per la configurazione:
+
+Nella sezione :menuselection:`Sending Preferences`:
+
+- :menuselection:`Do Not Send Flowed Text` deve essere ``enabled``
+- :menuselection:`Strip Whitespace Before Sending` deve essere ``disabled``
+
+Quando state scrivendo un messaggio, il cursore dev'essere posizionato
+dove volete che la patch inizi, poi premendo :kbd:`CTRL-R` vi verrà chiesto
+di selezionare il file patch da inserire nel messaggio.
+
+Claws Mail (GUI)
+****************
+
+Funziona. Alcune persone riescono ad usarlo con successo per inviare le patch.
+
+Per inserire una patch usate :menuselection:`Messaggio-->Inserisci file`
+(:kbd:`CTRL-I`) oppure un editor esterno.
+
+Se la patch che avete inserito dev'essere modificata usato la finestra di
+scrittura di Claws, allora assicuratevi che l'"auto-interruzione" sia
+disabilitata :menuselection:`Configurazione-->Preferenze-->Composizione-->Interruzione riga`.
+
+Evolution (GUI)
+***************
+
+Alcune persone riescono ad usarlo con successo per inviare le patch.
+
+Quando state scrivendo una lettera selezionate: Preformattato
+ da :menuselection:`Formato-->Stile del paragrafo-->Preformattato`
+ (:kbd:`CTRL-7`) o dalla barra degli strumenti
+
+Poi per inserire la patch usate:
+:menuselection:`Inserisci--> File di testo...` (:kbd:`ALT-N x`)
+
+Potete anche eseguire ``diff -Nru old.c new.c | xclip``, selezionare
+:menuselection:`Preformattato`, e poi usare il tasto centrale del mouse.
+
+Kmail (GUI)
+***********
+
+Alcune persone riescono ad usarlo con successo per inviare le patch.
+
+La configurazione base che disabilita la composizione di messaggi HTML è
+corretta; non abilitatela.
+
+Quando state scrivendo un messaggio, nel menu opzioni, togliete la selezione a
+"A capo automatico". L'unico svantaggio sarà che qualsiasi altra cosa scriviate
+nel messaggio non verrà mandata a capo in automatico ma dovrete farlo voi.
+Il modo più semplice per ovviare a questo problema è quello di scrivere il
+messaggio con l'opzione abilitata e poi di salvarlo nelle bozze. Riaprendo ora
+il messaggio dalle bozze le andate a capo saranno parte integrante del
+messaggio, per cui togliendo l'opzione "A capo automatico" non perderete nulla.
+
+Alla fine del vostro messaggio, appena prima di inserire la vostra patch,
+aggiungete il delimitatore di patch: tre trattini (``---``).
+
+Ora, dal menu :menuselection:`Messaggio`, selezionate :menuselection:`Inserisci file di testo...`
+quindi scegliete la vostra patch.
+Come soluzione aggiuntiva potreste personalizzare la vostra barra degli
+strumenti aggiungendo un'icona per :menuselection:`Inserisci file di testo...`.
+
+Allargate la finestra di scrittura abbastanza da evitare andate a capo.
+Questo perché in Kmail 1.13.5 (KDE 4.5.4), Kmail aggiunge andate a capo
+automaticamente al momento dell'invio per tutte quelle righe che graficamente,
+nella vostra finestra di composizione, si sono estete su una riga successiva.
+Disabilitare l'andata a capo automatica non è sufficiente. Dunque, se la vostra
+patch contiene delle righe molto lunghe, allora dovrete allargare la finestra
+di composizione per evitare che quelle righe vadano a capo. Vedere:
+https://bugs.kde.org/show_bug.cgi?id=174034
+
+Potete firmare gli allegati con GPG, ma per le patch si preferisce aggiungerle
+al testo del messaggio per cui non usate la firma GPG. Firmare le patch
+inserite come testo del messaggio le rende più difficili da estrarre dalla loro
+codifica a 7-bit.
+
+Se dovete assolutamente inviare delle patch come allegati invece di integrarle
+nel testo del messaggio, allora premete il tasto destro sull'allegato e
+selezionate :menuselection:`Proprietà`, e poi attivate
+:menuselection:`Suggerisci visualizzazione automatica` per far si che
+l'allegato sia più leggibile venendo visualizzato come parte del messaggio.
+
+Per salvare le patch inviate come parte di un messaggio, selezionate il
+messaggio che la contiene, premete il tasto destro e selezionate
+:menuselection:`Salva come`. Se il messaggio fu ben preparato, allora potrete
+usarlo interamente senza alcuna modifica.
+I messaggi vengono salvati con permessi di lettura-scrittura solo per l'utente,
+nel caso in cui vogliate copiarli altrove per renderli disponibili ad altri
+gruppi o al mondo, ricordatevi di usare ``chmod`` per cambiare i permessi.
+
+Lotus Notes (GUI)
+*****************
+
+Scappate finché potete.
+
+IBM Verse (Web GUI)
+*******************
+
+Vedi il commento per Lotus Notes.
+
+Mutt (TUI)
+**********
+
+Un sacco di sviluppatori Linux usano ``mutt``, per cui deve funzionare
+abbastanza bene.
+
+Mutt non ha un proprio editor, quindi qualunque sia il vostro editor dovrete
+configurarlo per non aggiungere automaticamente le andate a capo. Molti
+editor hanno un'opzione :menuselection:`Inserisci file` che inserisce il
+contenuto di un file senza alterarlo.
+
+Per usare ``vim`` come editor per mutt::
+
+ set editor="vi"
+
+Se per inserire la patch nel messaggio usate xclip, scrivete il comando::
+
+ :set paste
+
+prima di premere il tasto centrale o shift-insert. Oppure usate il
+comando::
+
+ :r filename
+
+(a)llega funziona bene senza ``set paste``
+
+Potete generare le patch con ``git format-patch`` e usare Mutt per inviarle::
+
+ $ mutt -H 0001-some-bug-fix.patch
+
+Opzioni per la configurazione:
+
+Tutto dovrebbe funzionare già nella configurazione base.
+Tuttavia, è una buona idea quella di impostare ``send_charset``::
+
+ set send_charset="us-ascii:utf-8"
+
+Mutt è molto personalizzabile. Qui di seguito trovate la configurazione minima
+per iniziare ad usare Mutt per inviare patch usando Gmail::
+
+ # .muttrc
+ # ================ IMAP ====================
+ set imap_user = 'yourusername@gmail.com'
+ set imap_pass = 'yourpassword'
+ set spoolfile = imaps://imap.gmail.com/INBOX
+ set folder = imaps://imap.gmail.com/
+ set record="imaps://imap.gmail.com/[Gmail]/Sent Mail"
+ set postponed="imaps://imap.gmail.com/[Gmail]/Drafts"
+ set mbox="imaps://imap.gmail.com/[Gmail]/All Mail"
+
+ # ================ SMTP ====================
+ set smtp_url = "smtp://username@smtp.gmail.com:587/"
+ set smtp_pass = $imap_pass
+ set ssl_force_tls = yes # Require encrypted connection
+
+ # ================ Composition ====================
+ set editor = `echo \$EDITOR`
+ set edit_headers = yes # See the headers when editing
+ set charset = UTF-8 # value of $LANG; also fallback for send_charset
+ # Sender, email address, and sign-off line must match
+ unset use_domain # because joe@localhost is just embarrassing
+ set realname = "YOUR NAME"
+ set from = "username@gmail.com"
+ set use_from = yes
+
+La documentazione di Mutt contiene molte più informazioni:
+
+ https://gitlab.com/muttmua/mutt/-/wikis/UseCases/Gmail
+
+ http://www.mutt.org/doc/manual/
+
+Pine (TUI)
+**********
+
+Pine aveva alcuni problemi con gli spazi vuoti, ma questi dovrebbero essere
+stati risolti.
+
+Se potete usate alpine (il successore di pine).
+
+Opzioni di configurazione:
+
+- Nelle versioni più recenti è necessario avere ``quell-flowed-text``
+- l'opzione ``no-strip-whitespace-before-send`` è necessaria
+
+Sylpheed (GUI)
+**************
+
+- funziona bene per aggiungere testo in linea (o usando allegati)
+- permette di utilizzare editor esterni
+- è lento su cartelle grandi
+- non farà l'autenticazione TSL SMTP su una connessione non SSL
+- ha un utile righello nella finestra di scrittura
+- la rubrica non comprende correttamente il nome da visualizzare e
+ l'indirizzo associato
+
+Thunderbird (GUI)
+*****************
+
+Thunderbird è un clone di Outlook a cui piace maciullare il testo, ma esistono
+modi per impedirglielo.
+
+- permettere l'uso di editor esterni:
+ La cosa più semplice da fare con Thunderbird e le patch è quello di usare
+ l'estensione "external editor" e di usare il vostro ``$EDITOR`` preferito per
+ leggere/includere patch nel vostro messaggio. Per farlo, scaricate ed
+ installate l'estensione e aggiungete un bottone per chiamarla rapidamente
+ usando :menuselection:`Visualizza-->Barra degli strumenti-->Personalizza...`;
+ una volta fatto potrete richiamarlo premendo sul bottone mentre siete nella
+ finestra :menuselection:`Scrivi`
+
+ Tenete presente che "external editor" richiede che il vostro editor non
+ faccia alcun fork, in altre parole, l'editor non deve ritornare prima di
+ essere stato chiuso. Potreste dover passare dei parametri aggiuntivi al
+ vostro editor oppure cambiargli la configurazione. Per esempio, usando
+ gvim dovrete aggiungere l'opzione -f ``/usr/bin/gvim -f`` (Se il binario
+ si trova in ``/usr/bin``) nell'apposito campo nell'interfaccia di
+ configurazione di :menuselection:`external editor`. Se usate altri editor
+ consultate il loro manuale per sapere come configurarli.
+
+Per rendere l'editor interno un po' più sensato, fate così:
+
+- Modificate le impostazioni di Thunderbird per far si che non usi
+ ``format=flowed``. Andate in :menuselection:`Modifica-->Preferenze-->Avanzate-->Editor di configurazione`
+ per invocare il registro delle impostazioni.
+
+- impostate ``mailnews.send_plaintext_flowed`` a ``false``
+
+- impostate ``mailnews.wraplength`` da ``72`` a ``0``
+
+- :menuselection:`Visualizza-->Corpo del messaggio come-->Testo semplice`
+
+- :menuselection:`Visualizza-->Codifica del testo-->Unicode`
+
+
+TkRat (GUI)
+***********
+
+Funziona. Usare "Inserisci file..." o un editor esterno.
+
+Gmail (Web GUI)
+***************
+
+Non funziona per inviare le patch.
+
+Il programma web Gmail converte automaticamente i tab in spazi.
+
+Allo stesso tempo aggiunge andata a capo ogni 78 caratteri. Comunque
+il problema della conversione fra spazi e tab può essere risolto usando
+un editor esterno.
+
+Un altro problema è che Gmail usa la codifica base64 per tutti quei messaggi
+che contengono caratteri non ASCII. Questo include cose tipo i nomi europei.
diff --git a/Documentation/translations/it_IT/process/index.rst b/Documentation/translations/it_IT/process/index.rst
index 012de0f..c4c8671 100644
--- a/Documentation/translations/it_IT/process/index.rst
+++ b/Documentation/translations/it_IT/process/index.rst
@@ -59,6 +59,7 @@
magic-number
volatile-considered-harmful
clang-format
+ ../riscv/patch-acceptance
.. only:: subproject and html
diff --git a/Documentation/translations/it_IT/process/management-style.rst b/Documentation/translations/it_IT/process/management-style.rst
index 07e68bf..c709285 100644
--- a/Documentation/translations/it_IT/process/management-style.rst
+++ b/Documentation/translations/it_IT/process/management-style.rst
@@ -1,12 +1,293 @@
.. include:: ../disclaimer-ita.rst
-:Original: :ref:`Documentation/process/management-style.rst <managementstyle>`
+:Original: :doc:`../../../process/management-style`
+:Translator: Alessia Mantegazza <amantegazza@vaga.pv.it>
-.. _it_managementstyle:
+Il modello di gestione del kernel Linux
+=======================================
-Tipo di gestione del kernel Linux
-=================================
+Questo breve documento descrive il modello di gestione del kernel Linux.
+Per certi versi, esso rispecchia il documento
+:ref:`translations/it_IT/process/coding-style.rst <it_codingstyle>`,
+ed è principalmente scritto per evitare di rispondere [#f1]_ in continuazione
+alle stesse identiche (o quasi) domande.
-.. warning::
+Il modello di gestione è qualcosa di molto personale e molto più difficile da
+qualificare rispetto a delle semplici regole di codifica, quindi questo
+documento potrebbe avere più o meno a che fare con la realtà. È cominciato
+come un gioco, ma ciò non significa che non possa essere vero.
+Lo dovrete decidere voi stessi.
- TODO ancora da tradurre
+In ogni caso, quando si parla del "dirigente del kernel", ci si riferisce
+sempre alla persona che dirige tecnicamente, e non a coloro che
+tradizionalmente hanno un ruolo direttivo all'interno delle aziende. Se vi
+occupate di convalidare acquisti o avete una qualche idea sul budget del vostro
+gruppo, probabilmente non siete un dirigente del kernel. Quindi i suggerimenti
+qui indicati potrebbero fare al caso vostro, oppure no.
+
+Prima di tutto, suggerirei di acquistare "Le sette regole per avere successo",
+e di non leggerlo. Bruciatelo, è un grande gesto simbolico.
+
+.. [#f1] Questo documento non fa molto per risponde alla domanda, ma rende
+ così dannatamente ovvio a chi la pone che non abbiamo la minima idea
+ di come rispondere.
+
+Comunque, partiamo:
+
+.. _it_decisions:
+
+1) Le decisioni
+---------------
+
+Tutti pensano che i dirigenti decidano, e che questo prendere decisioni
+sia importante. Più grande e dolorosa è la decisione, più importante deve
+essere il dirigente che la prende. Questo è molto profondo ed ovvio, ma non è
+del tutto vero.
+
+Il gioco consiste nell'"evitare" di dover prendere decisioni. In particolare
+se qualcuno vi chiede di "Decidere" tra (a) o (b), e vi dice che ha
+davvero bisogno di voi per questo, come dirigenti siete nei guai.
+Le persone che gestite devono conoscere i dettagli più di quanto li conosciate
+voi, quindi se vengono da voi per una decisione tecnica, siete fottuti.
+Non sarete chiaramente competente per prendere quella decisione per loro.
+
+(Corollario: se le persone che gestite non conoscono i dettagli meglio di voi,
+anche in questo caso sarete fregati, tuttavia per altre ragioni. Ossia state
+facendo il lavoro sbagliato, e che invece dovrebbero essere "loro" a gestirvi)
+
+Quindi il gioco si chiama "evitare" decisioni, almeno le più grandi e
+difficili. Prendere decisioni piccoli e senza conseguenze va bene, e vi fa
+sembrare competenti in quello che state facendo, quindi quello che un dirigente
+del kernel ha bisogno di fare è trasformare le decisioni grandi e difficili
+in minuzie delle quali nessuno importa.
+
+Ciò aiuta a capire che la differenza chiave tra una grande decisione ed una
+piccola sta nella possibilità di modificare tale decisione in seguito.
+Qualsiasi decisione importante può essere ridotta in decisioni meno importanti,
+ma dovete assicurarvi che possano essere reversibili in caso di errori
+(presenti o futuri). Improvvisamente, dovrete essere doppiamente dirigenti
+per **due** decisioni non sequenziali - quella sbagliata **e** quella giusta.
+
+E le persone vedranno tutto ciò come prova di vera capacità di comando
+(*cough* cavolata *cough*)
+
+Così la chiave per evitare le decisioni difficili diviene l'evitare
+di fare cose che non possono essere disfatte. Non infilatevi in un angolo
+dal quale non potrete sfuggire. Un topo messo all'angolo può rivelarsi
+pericoloso - un dirigente messo all'angolo è solo pietoso.
+
+**In ogni caso** dato che nessuno è stupido al punto da lasciare veramente ad
+un dirigente del kernel un enorme responsabilità, solitamente è facile fare
+marcia indietro. Annullare una decisione è molto facile: semplicemente dite a
+tutti che siete stati degli scemi incompetenti, dite che siete dispiaciuti, ed
+annullate tutto l'inutile lavoro sul quale gli altri hanno lavorato nell'ultimo
+anno. Improvvisamente la decisione che avevate preso un anno fa non era poi
+così grossa, dato che può essere facilmente annullata.
+
+È emerso che alcune persone hanno dei problemi con questo tipo di approccio,
+questo per due ragioni:
+
+ - ammettere di essere degli idioti è più difficile di quanto sembri. A tutti
+ noi piace mantenere le apparenze, ed uscire allo scoperto in pubblico per
+ ammettere che ci si è sbagliati è qualcosa di davvero impegnativo.
+ - avere qualcuno che ti dice che ciò su cui hai lavorato nell'ultimo anno
+ non era del tutto valido, può rivelarsi difficile anche per un povero ed
+ umile ingegnere, e mentre il **lavoro** vero era abbastanza facile da
+ cancellare, dall'altro canto potreste aver irrimediabilmente perso la
+ fiducia di quell'ingegnere. E ricordate che l'"irrevocabile" era quello
+ che avevamo cercato di evitare fin dall'inizio, e la vostra decisione
+ ha finito per esserlo.
+
+Fortunatamente, entrambe queste ragioni posso essere mitigate semplicemente
+ammettendo fin dal principio che non avete una cavolo di idea, dicendo
+agli altri in anticipo che la vostra decisione è puramente ipotetica, e che
+potrebbe essere sbagliata. Dovreste sempre riservarvi il diritto di cambiare
+la vostra opinione, e rendere gli altri ben **consapevoli** di ciò.
+Ed è molto più facile ammettere di essere stupidi quando non avete **ancora**
+fatto quella cosa stupida.
+
+Poi, quando è realmente emersa la vostra stupidità, le persone semplicemente
+roteeranno gli occhi e diranno "Uffa, no, ancora".
+
+Questa ammissione preventiva di incompetenza potrebbe anche portare le persone
+che stanno facendo il vero lavoro, a pensarci due volte. Dopo tutto, se
+**loro** non sono certi se sia una buona idea, voi, sicuro come la morte,
+non dovreste incoraggiarli promettendogli che ciò su cui stanno lavorando
+verrà incluso. Fate si che ci pensino due volte prima che si imbarchino in un
+grosso lavoro.
+
+Ricordate: loro devono sapere più cose sui dettagli rispetto a voi, e
+solitamente pensano di avere già la risposta a tutto. La miglior cosa che
+potete fare in qualità di dirigente è di non instillare troppa fiducia, ma
+invece fornire una salutare dose di pensiero critico su quanto stanno facendo.
+
+Comunque, un altro modo di evitare una decisione è quello di lamentarsi
+malinconicamente dicendo : "non possiamo farli entrambi e basta?" e con uno
+sguardo pietoso. Fidatevi, funziona. Se non è chiaro quale sia il miglior
+approccio, lo scopriranno. La risposta potrebbe essere data dal fatto che
+entrambe i gruppi di lavoro diventano frustati al punto di rinunciarvi.
+
+Questo può suonare come un fallimento, ma di solito questo è un segno che
+c'era qualcosa che non andava in entrambe i progetti, e il motivo per
+il quale le persone coinvolte non abbiano potuto decidere era che entrambe
+sbagliavano. Voi ne uscirete freschi come una rosa, e avrete evitato un'altra
+decisione con la quale avreste potuto fregarvi.
+
+
+2) Le persone
+-------------
+
+Ci sono molte persone stupide, ed essere un dirigente significa che dovrete
+scendere a patti con questo, e molto più importate, che **loro** devono avere
+a che fare con **voi**.
+
+Ne emerge che mentre è facile annullare degli errori tecnici, non è invece
+così facile rimuovere i disordini della personalità. Dovrete semplicemente
+convivere con i loro, ed i vostri, problemi.
+
+Comunque, al fine di preparavi in qualità di dirigenti del kernel, è meglio
+ricordare di non abbattere alcun ponte, bombardare alcun paesano innocente,
+o escludere troppi sviluppatori kernel. Ne emerge che escludere le persone
+è piuttosto facile, mentre includerle nuovamente è difficile. Così
+"l'esclusione" immediatamente cade sotto il titolo di "non reversibile", e
+diviene un no-no secondo la sezione :ref:`it_decisions`.
+
+Esistono alcune semplici regole qui:
+
+ (1) non chiamate le persone teste di c*** (al meno, non in pubblico)
+ (2) imparate a scusarvi quando dimenticate la regola (1)
+
+Il problema del punto numero 1 è che è molto facile da rispettare, dato che
+è possibile dire "sei una testa di c***" in milioni di modi differenti [#f2]_,
+a volte senza nemmeno pensarci, e praticamente sempre con la calda convinzione
+di essere nel giusto.
+
+E più convinti sarete che avete ragione (e diciamolo, potete chiamare
+praticamente **tutti** testa di c**, e spesso **sarete** nel giusto), più
+difficile sarà scusarvi successivamente.
+
+Per risolvere questo problema, avete due possibilità:
+
+ - diventare davvero bravi nello scusarsi
+ - essere amabili così che nessuno finirà col sentirsi preso di mira. Siate
+ creativi abbastanza, e potrebbero esserne divertiti.
+
+L'opzione dell'essere immancabilmente educati non esiste proprio. Nessuno
+si fiderà di qualcuno che chiaramente sta nascondendo il suo vero carattere.
+
+.. [#f2] Paul Simon cantava: "50 modi per lasciare il vostro amante", perché,
+ molto francamente, "Un milione di modi per dire ad uno sviluppatore
+ Testa di c***" non avrebbe funzionato. Ma sono sicuro che ci abbia
+ pensato.
+
+
+3) Le persone II - quelle buone
+-------------------------------
+
+Mentre emerge che la maggior parte delle persone sono stupide, il corollario
+a questo è il triste fatto che anche voi siete fra queste, e che mentre
+possiamo tutti crogiolarci nella sicurezza di essere migliori della media
+delle persone (diciamocelo, nessuno crede di essere nelle media o sotto di
+essa), dovremmo anche ammettere che non siamo il "coltello più affilato" del
+circondario, e che ci saranno altre persone che sono meno stupide di quanto
+lo siete voi.
+
+Molti reagiscono male davanti alle persone intelligenti. Altri le usano a
+proprio vantaggio.
+
+Assicuratevi che voi, in qualità di manutentori del kernel, siate nel secondo
+gruppo. Inchinatevi dinanzi a loro perché saranno le persone che vi renderanno
+il lavoro più facile. In particolare, prenderanno le decisioni per voi, che è
+l'oggetto di questo gioco.
+
+Quindi quando trovate qualcuno più sveglio di voi, prendetevela comoda.
+Le vostre responsabilità dirigenziali si ridurranno in gran parte nel dire
+"Sembra una buona idea - Vai", oppure "Sembra buono, ma invece circa questo e
+quello?". La seconda versione in particolare è una gran modo per imparare
+qualcosa di nuovo circa "questo e quello" o di sembrare **extra** dirigenziali
+sottolineando qualcosa alla quale i più svegli non avevano pensato. In
+entrambe i casi, vincete.
+
+Una cosa alla quale dovete fare attenzione è che l'essere grandi in qualcosa
+non si traduce automaticamente nell'essere grandi anche in altre cose. Quindi
+dovreste dare una spintarella alle persone in una specifica direzione, ma
+diciamocelo, potrebbero essere bravi in ciò che fanno e far schifo in tutto
+il resto. La buona notizia è che le persone tendono a gravitare attorno a ciò
+in cui sono bravi, quindi non state facendo nulla di irreversibile quando li
+spingete verso una certa direzione, solo non spingete troppo.
+
+
+4) Addossare le colpe
+---------------------
+
+Le cose andranno male, e le persone vogliono qualcuno da incolpare. Sarete voi.
+
+Non è poi così difficile accettare la colpa, specialmente se le persone
+riescono a capire che non era **tutta** colpa vostra. Il che ci porta
+sulla miglior strada per assumersi la colpa: fatelo per qualcun'altro.
+Vi sentirete bene nel assumervi la responsabilità, e loro si sentiranno
+bene nel non essere incolpati, e coloro che hanno perso i loro 36GB di
+pornografia a causa della vostra incompetenza ammetteranno a malincuore che
+almeno non avete cercato di fare il furbetto.
+
+Successivamente fate in modo che gli sviluppatori che in realtà hanno fallito
+(se riuscite a trovarli) sappiano **in privato** che sono "fottuti".
+Questo non per fargli sapere che la prossima volta possono evitarselo ma per
+fargli capire che sono in debito. E, forse cosa più importante, sono loro che
+devono sistemare la cosa. Perché, ammettiamolo, è sicuro non sarete voi a
+farlo.
+
+Assumersi la colpa è anche ciò che vi rendere dirigenti in prima battuta.
+È parte di ciò che spinge gli altri a fidarsi di voi, e vi garantisce
+la gloria potenziale, perché siete gli unici a dire "Ho fatto una cavolata".
+E se avete seguito le regole precedenti, sarete decisamente bravi nel dirlo.
+
+
+5) Le cose da evitare
+---------------------
+
+Esiste una cosa che le persone odiano più che essere chiamate "teste di c****",
+ed è essere chiamate "teste di c****" con fare da bigotto. Se per il primo
+caso potrete comunque scusarvi, per il secondo non ve ne verrà data nemmeno
+l'opportunità. Probabilmente smetteranno di ascoltarvi anche se tutto sommato
+state svolgendo un buon lavoro.
+
+Tutti crediamo di essere migliori degli altri, il che significa che quando
+qualcuno inizia a darsi delle arie, ci da **davvero** fastidio. Potreste anche
+essere moralmente ed intellettualmente superiore a tutti quelli attorno a voi,
+ma non cercate di renderlo ovvio per gli altri a meno che non **vogliate**
+veramente far arrabbiare qualcuno [#f3]_.
+
+Allo stesso modo evitate di essere troppo gentili e pacati. Le buone maniere
+facilmente finiscono per strabordare e nascondere i problemi, e come si usa
+dire, "su internet nessuno può sentire la vostra pacatezza". Usate argomenti
+diretti per farvi capire, non potete sperare che la gente capisca in altro
+modo.
+
+Un po' di umorismo può aiutare a smorzare sia la franchezza che la moralità.
+Andare oltre i limiti al punto d'essere ridicolo può portare dei punti a casa
+senza renderlo spiacevole per i riceventi, i quali penseranno che stavate
+facendo gli scemi. Può anche aiutare a lasciare andare quei blocchi mentali
+che abbiamo nei confronti delle critiche.
+
+.. [#f3] Suggerimento: i forum di discussione su internet, che non sono
+ collegati col vostro lavoro, sono ottimi modi per sfogare la frustrazione
+ verso altre persone. Di tanto in tanto scrivete messaggi offensivi col ghigno
+ in faccia per infiammare qualche discussione: vi sentirete purificati. Solo
+ cercate di non cagare troppo vicino a casa.
+
+6) Perché io?
+-------------
+
+Dato che la vostra responsabilità principale è quella di prendervi le colpe
+d'altri, e rendere dolorosamente ovvio a tutti che siete degli incompetenti,
+la domanda naturale che ne segue sarà : perché dovrei fare tutto ciò?
+
+Innanzitutto, potreste diventare o no popolari al punto da avere la fila di
+ragazzine (o ragazzini, evitiamo pregiudizi o sessismo) che gridano e bussano
+alla porta del vostro camerino, ma comunque **proverete** un immenso senso di
+realizzazione personale dall'essere "in carica". Dimenticate il fatto che voi
+state discutendo con tutti e che cercate di inseguirli il più velocemente che
+potete. Tutti continueranno a pensare che voi siete la persona in carica.
+
+È un bel lavoro se riuscite ad adattarlo a voi.
diff --git a/Documentation/translations/it_IT/process/submit-checklist.rst b/Documentation/translations/it_IT/process/submit-checklist.rst
index 995ee69..3e57550 100644
--- a/Documentation/translations/it_IT/process/submit-checklist.rst
+++ b/Documentation/translations/it_IT/process/submit-checklist.rst
@@ -117,7 +117,7 @@
sorgenti che ne spieghi la logica: cosa fanno e perché.
25) Se la patch aggiunge nuove chiamate ioctl, allora aggiornate
- ``Documentation/ioctl/ioctl-number.rst``.
+ ``Documentation/userspace-api/ioctl/ioctl-number.rst``.
26) Se il codice che avete modificato dipende o usa una qualsiasi interfaccia o
funzionalità del kernel che è associata a uno dei seguenti simboli
diff --git a/Documentation/translations/it_IT/riscv/patch-acceptance.rst b/Documentation/translations/it_IT/riscv/patch-acceptance.rst
new file mode 100644
index 0000000..edf6725
--- /dev/null
+++ b/Documentation/translations/it_IT/riscv/patch-acceptance.rst
@@ -0,0 +1,40 @@
+.. include:: ../disclaimer-ita.rst
+
+:Original: :doc:`../../../riscv/patch-acceptance`
+:Translator: Federico Vaga <federico.vaga@vaga.pv.it>
+
+arch/riscv linee guida alla manutenzione per gli sviluppatori
+=============================================================
+
+Introduzione
+------------
+
+L'insieme di istruzioni RISC-V sono sviluppate in modo aperto: le
+bozze in fase di sviluppo sono disponibili a tutti per essere
+revisionate e per essere sperimentare nelle implementazioni. Le bozze
+dei nuovi moduli o estensioni possono cambiare in fase di sviluppo - a
+volte in modo incompatibile rispetto a bozze precedenti. Questa
+flessibilità può portare a dei problemi di manutenzioni per il
+supporto RISC-V nel kernel Linux. I manutentori Linux non amano
+l'abbandono del codice, e il processo di sviluppo del kernel
+preferisce codice ben revisionato e testato rispetto a quello
+sperimentale. Desideriamo estendere questi stessi principi al codice
+relativo all'architettura RISC-V che verrà accettato per l'inclusione
+nel kernel.
+
+In aggiunta alla lista delle verifiche da fare prima di inviare una patch
+-------------------------------------------------------------------------
+
+Accetteremo le patch per un nuovo modulo o estensione se la fondazione
+RISC-V li classifica come "Frozen" o "Retified". (Ovviamente, gli
+sviluppatori sono liberi di mantenere una copia del kernel Linux
+contenente il codice per una bozza di estensione).
+
+In aggiunta, la specifica RISC-V permette agli implementatori di
+creare le proprie estensioni. Queste estensioni non passano
+attraverso il processo di revisione della fondazione RISC-V. Per
+questo motivo, al fine di evitare complicazioni o problemi di
+prestazioni, accetteremo patch solo per quelle estensioni che sono
+state ufficialmente accettate dalla fondazione RISC-V. (Ovviamente,
+gli implementatori sono liberi di mantenere una copia del kernel Linux
+contenente il codice per queste specifiche estensioni).
diff --git a/Documentation/translations/ko_KR/memory-barriers.txt b/Documentation/translations/ko_KR/memory-barriers.txt
index 2e831ec..e50fe65 100644
--- a/Documentation/translations/ko_KR/memory-barriers.txt
+++ b/Documentation/translations/ko_KR/memory-barriers.txt
@@ -641,7 +641,7 @@
리눅스 커널이 지원하는 CPU 들은 (1) 쓰기가 정말로 일어날지, (2) 쓰기가 어디에
이루어질지, 그리고 (3) 쓰여질 값을 확실히 알기 전까지는 쓰기를 수행하지 않기
때문입니다. 하지만 "컨트롤 의존성" 섹션과
-Documentation/RCU/rcu_dereference.txt 파일을 주의 깊게 읽어 주시기 바랍니다:
+Documentation/RCU/rcu_dereference.rst 파일을 주의 깊게 읽어 주시기 바랍니다:
컴파일러는 매우 창의적인 많은 방법으로 종속성을 깰 수 있습니다.
CPU 1 CPU 2
diff --git a/Documentation/translations/zh_CN/IRQ.txt b/Documentation/translations/zh_CN/IRQ.txt
index 956026d..9aec8dc 100644
--- a/Documentation/translations/zh_CN/IRQ.txt
+++ b/Documentation/translations/zh_CN/IRQ.txt
@@ -1,4 +1,4 @@
-Chinese translated version of Documentation/IRQ.txt
+Chinese translated version of Documentation/core-api/irq/index.rst
If you have any comment or update to the content, please contact the
original document maintainer directly. However, if you have a problem
@@ -9,7 +9,7 @@
Maintainer: Eric W. Biederman <ebiederman@xmission.com>
Chinese maintainer: Fu Wei <tekkamanninja@gmail.com>
---------------------------------------------------------------------
-Documentation/IRQ.txt 的中文翻译
+Documentation/core-api/irq/index.rst 的中文翻译
如果想评论或更新本文的内容，请直接联系原文档的维护者。如果你使用英文
交流有困难的话，也可以向中文版维护者求助。如果本翻译更新不及时或者翻
diff --git a/Documentation/translations/zh_CN/filesystems/debugfs.rst b/Documentation/translations/zh_CN/filesystems/debugfs.rst
new file mode 100644
index 0000000..f8a2879
--- /dev/null
+++ b/Documentation/translations/zh_CN/filesystems/debugfs.rst
@@ -0,0 +1,221 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+.. include:: ../disclaimer-zh_CN.rst
+
+:Original: :ref:`Documentation/filesystems/debugfs.txt <debugfs_index>`
+
+=======
+Debugfs
+=======
+
+译者
+::
+
+ 中文版维护者： 罗楚成 Chucheng Luo <luochucheng@vivo.com>
+ 中文版翻译者： 罗楚成 Chucheng Luo <luochucheng@vivo.com>
+ 中文版校译者: 罗楚成 Chucheng Luo <luochucheng@vivo.com>
+
+
+
+版权所有2020 罗楚成 <luochucheng@vivo.com>
+
+
+Debugfs是内核开发人员在用户空间获取信息的简单方法。与/proc不同，proc只提供进程
+信息。也不像sysfs,具有严格的“每个文件一个值“的规则。debugfs根本没有规则,开发
+人员可以在这里放置他们想要的任何信息。debugfs文件系统也不能用作稳定的ABI接口。
+从理论上讲，debugfs导出文件的时候没有任何约束。但是[1]实际情况并不总是那么
+简单。即使是debugfs接口，也最好根据需要进行设计,并尽量保持接口不变。
+
+
+Debugfs通常使用以下命令安装::
+
+ mount -t debugfs none /sys/kernel/debug
+
+（或等效的/etc/fstab行）。
+debugfs根目录默认仅可由root用户访问。要更改对文件树的访问，请使用“ uid”，“ gid”
+和“ mode”挂载选项。请注意，debugfs API仅按照GPL协议导出到模块。
+
+使用debugfs的代码应包含<linux/debugfs.h>。然后，首先是创建至少一个目录来保存
+一组debugfs文件::
+
+ struct dentry *debugfs_create_dir(const char *name, struct dentry *parent);
+
+如果成功，此调用将在指定的父目录下创建一个名为name的目录。如果parent参数为空，
+则会在debugfs根目录中创建。创建目录成功时，返回值是一个指向dentry结构体的指针。
+该dentry结构体的指针可用于在目录中创建文件（以及最后将其清理干净）。ERR_PTR
+（-ERROR）返回值表明出错。如果返回ERR_PTR（-ENODEV），则表明内核是在没有debugfs
+支持的情况下构建的，并且下述函数都不会起作用。
+
+在debugfs目录中创建文件的最通用方法是::
+
+ struct dentry *debugfs_create_file(const char *name, umode_t mode,
+ struct dentry *parent, void *data,
+ const struct file_operations *fops);
+
+在这里，name是要创建的文件的名称，mode描述了访问文件应具有的权限，parent指向
+应该保存文件的目录，data将存储在产生的inode结构体的i_private字段中，而fops是
+一组文件操作函数，这些函数中实现文件操作的具体行为。至少，read（）和/或
+write（）操作应提供；其他可以根据需要包括在内。同样的，返回值将是指向创建文件
+的dentry指针，错误时返回ERR_PTR（-ERROR），系统不支持debugfs时返回值为ERR_PTR
+（-ENODEV）。创建一个初始大小的文件，可以使用以下函数代替::
+
+ struct dentry *debugfs_create_file_size(const char *name, umode_t mode,
+ struct dentry *parent, void *data,
+ const struct file_operations *fops,
+ loff_t file_size);
+
+file_size是初始文件大小。其他参数跟函数debugfs_create_file的相同。
+
+在许多情况下，没必要自己去创建一组文件操作;对于一些简单的情况,debugfs代码提供
+了许多帮助函数。包含单个整数值的文件可以使用以下任何一项创建::
+
+ void debugfs_create_u8(const char *name, umode_t mode,
+ struct dentry *parent, u8 *value);
+ void debugfs_create_u16(const char *name, umode_t mode,
+ struct dentry *parent, u16 *value);
+ struct dentry *debugfs_create_u32(const char *name, umode_t mode,
+ struct dentry *parent, u32 *value);
+ void debugfs_create_u64(const char *name, umode_t mode,
+ struct dentry *parent, u64 *value);
+
+这些文件支持读取和写入给定值。如果某个文件不支持写入，只需根据需要设置mode
+参数位。这些文件中的值以十进制表示；如果需要使用十六进制，可以使用以下函数
+替代::
+
+ void debugfs_create_x8(const char *name, umode_t mode,
+ struct dentry *parent, u8 *value);
+ void debugfs_create_x16(const char *name, umode_t mode,
+ struct dentry *parent, u16 *value);
+ void debugfs_create_x32(const char *name, umode_t mode,
+ struct dentry *parent, u32 *value);
+ void debugfs_create_x64(const char *name, umode_t mode,
+ struct dentry *parent, u64 *value);
+
+这些功能只有在开发人员知道导出值的大小的时候才有用。某些数据类型在不同的架构上
+有不同的宽度，这样会使情况变得有些复杂。在这种特殊情况下可以使用以下函数::
+
+ void debugfs_create_size_t(const char *name, umode_t mode,
+ struct dentry *parent, size_t *value);
+
+不出所料，此函数将创建一个debugfs文件来表示类型为size_t的变量。
+
+同样地，也有导出无符号长整型变量的函数，分别以十进制和十六进制表示如下::
+
+ struct dentry *debugfs_create_ulong(const char *name, umode_t mode,
+ struct dentry *parent,
+ unsigned long *value);
+ void debugfs_create_xul(const char *name, umode_t mode,
+ struct dentry *parent, unsigned long *value);
+
+布尔值可以通过以下方式放置在debugfs中::
+
+ struct dentry *debugfs_create_bool(const char *name, umode_t mode,
+ struct dentry *parent, bool *value);
+
+
+读取结果文件将产生Y（对于非零值）或N，后跟换行符写入的时候，它只接受大写或小写
+值或1或0。任何其他输入将被忽略。
+
+同样，atomic_t类型的值也可以放置在debugfs中::
+
+ void debugfs_create_atomic_t(const char *name, umode_t mode,
+ struct dentry *parent, atomic_t *value)
+
+读取此文件将获得atomic_t值，写入此文件将设置atomic_t值。
+
+另一个选择是通过以下结构体和函数导出一个任意二进制数据块::
+
+ struct debugfs_blob_wrapper {
+ void *data;
+ unsigned long size;
+ };
+
+ struct dentry *debugfs_create_blob(const char *name, umode_t mode,
+ struct dentry *parent,
+ struct debugfs_blob_wrapper *blob);
+
+读取此文件将返回由指针指向debugfs_blob_wrapper结构体的数据。一些驱动使用“blobs”
+作为一种返回几行（静态）格式化文本的简单方法。这个函数可用于导出二进制信息，但
+似乎在主线中没有任何代码这样做。请注意，使用debugfs_create_blob（）命令创建的
+所有文件是只读的。
+
+如果您要转储一个寄存器块（在开发过程中经常会这么做，但是这样的调试代码很少上传
+到主线中。Debugfs提供两个函数：一个用于创建仅寄存器文件，另一个把一个寄存器块
+插入一个顺序文件中::
+
+ struct debugfs_reg32 {
+ char *name;
+ unsigned long offset;
+ };
+
+ struct debugfs_regset32 {
+ struct debugfs_reg32 *regs;
+ int nregs;
+ void __iomem *base;
+ };
+
+ struct dentry *debugfs_create_regset32(const char *name, umode_t mode,
+ struct dentry *parent,
+ struct debugfs_regset32 *regset);
+
+ void debugfs_print_regs32(struct seq_file *s, struct debugfs_reg32 *regs,
+ int nregs, void __iomem *base, char *prefix);
+
+“base”参数可能为0，但您可能需要使用__stringify构建reg32数组，实际上有许多寄存器
+名称（宏）是寄存器块在基址上的字节偏移量。
+
+如果要在debugfs中转储u32数组，可以使用以下函数创建文件::
+
+ void debugfs_create_u32_array(const char *name, umode_t mode,
+ struct dentry *parent,
+ u32 *array, u32 elements);
+
+“array”参数提供数据，而“elements”参数为数组中元素的数量。注意：数组创建后，数组
+大小无法更改。
+
+有一个函数来创建与设备相关的seq_file::
+
+ struct dentry *debugfs_create_devm_seqfile(struct device *dev,
+ const char *name,
+ struct dentry *parent,
+ int (*read_fn)(struct seq_file *s,
+ void *data));
+
+“dev”参数是与此debugfs文件相关的设备，并且“read_fn”是一个函数指针，这个函数在
+打印seq_file内容的时候被回调。
+
+还有一些其他的面向目录的函数::
+
+ struct dentry *debugfs_rename(struct dentry *old_dir,
+ struct dentry *old_dentry,
+ struct dentry *new_dir,
+ const char *new_name);
+
+ struct dentry *debugfs_create_symlink(const char *name,
+ struct dentry *parent,
+ const char *target);
+
+调用debugfs_rename()将为现有的debugfs文件重命名，可能同时切换目录。 new_name
+函数调用之前不能存在；返回值为old_dentry，其中包含更新的信息。可以使用
+debugfs_create_symlink（）创建符号链接。
+
+所有debugfs用户必须考虑的一件事是：
+
+debugfs不会自动清除在其中创建的任何目录。如果一个模块在不显式删除debugfs目录的
+情况下卸载模块，结果将会遗留很多野指针，从而导致系统不稳定。因此，所有debugfs
+用户-至少是那些可以作为模块构建的用户-必须做模块卸载的时候准备删除在此创建的
+所有文件和目录。一份文件可以通过以下方式删除::
+
+ void debugfs_remove(struct dentry *dentry);
+
+dentry值可以为NULL或错误值，在这种情况下，不会有任何文件被删除。
+
+很久以前，内核开发者使用debugfs时需要记录他们创建的每个dentry指针，以便最后所有
+文件都可以被清理掉。但是，现在debugfs用户能调用以下函数递归清除之前创建的文件::
+
+ void debugfs_remove_recursive(struct dentry *dentry);
+
+如果将对应顶层目录的dentry传递给以上函数，则该目录下的整个层次结构将会被删除。
+
+注释：
+[1] http://lwn.net/Articles/309298/
diff --git a/Documentation/translations/zh_CN/filesystems/index.rst b/Documentation/translations/zh_CN/filesystems/index.rst
index 14f155e..186501d 100644
--- a/Documentation/translations/zh_CN/filesystems/index.rst
+++ b/Documentation/translations/zh_CN/filesystems/index.rst
@@ -24,4 +24,5 @@
:maxdepth: 2
virtiofs
+ debugfs
diff --git a/Documentation/translations/zh_CN/filesystems/sysfs.txt b/Documentation/translations/zh_CN/filesystems/sysfs.txt
index ee1f37d..fcf6200 100644
--- a/Documentation/translations/zh_CN/filesystems/sysfs.txt
+++ b/Documentation/translations/zh_CN/filesystems/sysfs.txt
@@ -1,4 +1,4 @@
-Chinese translated version of Documentation/filesystems/sysfs.txt
+Chinese translated version of Documentation/filesystems/sysfs.rst
If you have any comment or update to the content, please contact the
original document maintainer directly. However, if you have a problem
@@ -10,7 +10,7 @@
Mike Murphy <mamurph@cs.clemson.edu>
Chinese maintainer: Fu Wei <tekkamanninja@gmail.com>
---------------------------------------------------------------------
-Documentation/filesystems/sysfs.txt 的中文翻译
+Documentation/filesystems/sysfs.rst 的中文翻译
如果想评论或更新本文的内容，请直接联系原文档的维护者。如果你使用英文
交流有困难的话，也可以向中文版维护者求助。如果本翻译更新不及时或者翻
@@ -40,7 +40,7 @@
数据结构及其属性，以及它们之间的关联到用户空间的方法。
sysfs 始终与 kobject 的底层结构紧密相关。请阅读
-Documentation/kobject.txt 文档以获得更多关于 kobject 接口的
+Documentation/core-api/kobject.rst 文档以获得更多关于 kobject 接口的
信息。
@@ -281,7 +281,7 @@
假定驱动没有跨越多个总线类型)。
fs/ 包含了一个为文件系统设立的目录。现在每个想要导出属性的文件系统必须
-在 fs/ 下创建自己的层次结构(参见Documentation/filesystems/fuse.txt)。
+在 fs/ 下创建自己的层次结构(参见Documentation/filesystems/fuse.rst)。
dev/ 包含两个子目录： char/ 和 block/。在这两个子目录中，有以
<major>:<minor> 格式命名的符号链接。这些符号链接指向 sysfs 目录
diff --git a/Documentation/translations/zh_CN/process/submit-checklist.rst b/Documentation/translations/zh_CN/process/submit-checklist.rst
index 8738c55..50386e0 100644
--- a/Documentation/translations/zh_CN/process/submit-checklist.rst
+++ b/Documentation/translations/zh_CN/process/submit-checklist.rst
@@ -97,7 +97,7 @@
24) 所有内存屏障例如 ``barrier()``, ``rmb()``, ``wmb()`` 都需要源代码中的注
释来解释它们正在执行的操作及其原因的逻辑。
-25) 如果补丁添加了任何ioctl，那么也要更新 ``Documentation/ioctl/ioctl-number.rst``
+25) 如果补丁添加了任何ioctl，那么也要更新 ``Documentation/userspace-api/ioctl/ioctl-number.rst``
26) 如果修改后的源代码依赖或使用与以下 ``Kconfig`` 符号相关的任何内核API或
功能，则在禁用相关 ``Kconfig`` 符号和/或 ``=m`` （如果该选项可用）的情况
diff --git a/Documentation/translations/zh_CN/video4linux/v4l2-framework.txt b/Documentation/translations/zh_CN/video4linux/v4l2-framework.txt
index 9c39ee5..a96abcd 100644
--- a/Documentation/translations/zh_CN/video4linux/v4l2-framework.txt
+++ b/Documentation/translations/zh_CN/video4linux/v4l2-framework.txt
@@ -488,7 +488,7 @@
这个函数会加载给定的模块（如果没有模块需要加载，可以为 NULL），
并用给定的 i2c 适配器结构体指针（i2c_adapter）和 器件地址（chip/address）
-作为参数调用 i2c_new_device()。如果一切顺利，则就在 v4l2_device
+作为参数调用 i2c_new_client_device()。如果一切顺利，则就在 v4l2_device
中注册了子设备。
你也可以利用 v4l2_i2c_new_subdev()的最后一个参数，传递一个可能的
diff --git a/Documentation/usb/gadget_configfs.rst b/Documentation/usb/gadget_configfs.rst
index 54fb08b..158e48d 100644
--- a/Documentation/usb/gadget_configfs.rst
+++ b/Documentation/usb/gadget_configfs.rst
@@ -24,7 +24,7 @@
Creating a gadget means deciding what configurations there will be
and which functions each configuration will provide.
-Configfs (please see `Documentation/filesystems/configfs/*`) lends itself nicely
+Configfs (please see `Documentation/filesystems/configfs.rst`) lends itself nicely
for the purpose of telling the kernel about the above mentioned decision.
This document is about how to do it.
@@ -354,7 +354,7 @@
a number of its default sub-groups created automatically.
For more information on configfs please see
-`Documentation/filesystems/configfs/*`.
+`Documentation/filesystems/configfs.rst`.
The concepts described above translate to USB gadgets like this:
diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
index f759eda..52bf584 100644
--- a/Documentation/userspace-api/ioctl/ioctl-number.rst
+++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
@@ -146,6 +146,7 @@
'H' 40-4F sound/hdspm.h conflict!
'H' 40-4F sound/hdsp.h conflict!
'H' 90 sound/usb/usx2y/usb_stream.h
+'H' 00-0F uapi/misc/habanalabs.h conflict!
'H' A0 uapi/linux/usb/cdc-wdm.h
'H' C0-F0 net/bluetooth/hci.h conflict!
'H' C0-DF net/bluetooth/hidp/hidp.h conflict!
diff --git a/Documentation/virt/kvm/amd-memory-encryption.rst b/Documentation/virt/kvm/amd-memory-encryption.rst
index c3129b9..57c01f5 100644
--- a/Documentation/virt/kvm/amd-memory-encryption.rst
+++ b/Documentation/virt/kvm/amd-memory-encryption.rst
@@ -74,7 +74,7 @@
device, if needed (see individual commands).
On output, ``error`` is zero on success, or an error code. Error codes
-are defined in ``<linux/psp-dev.h>`.
+are defined in ``<linux/psp-dev.h>``.
KVM implements the following commands to support common lifecycle events of SEV
guests, such as launching, running, snapshotting, migrating and decommissioning.
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index efbbe57..d2c1cbc 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -2572,13 +2572,15 @@
:Parameters: None
:Returns: 0 on success, -1 on error
-This signals to the host kernel that the specified guest is being paused by
-userspace. The host will set a flag in the pvclock structure that is checked
-from the soft lockup watchdog. The flag is part of the pvclock structure that
-is shared between guest and host, specifically the second bit of the flags
+This ioctl sets a flag accessible to the guest indicating that the specified
+vCPU has been paused by the host userspace.
+
+The host will set a flag in the pvclock structure that is checked from the
+soft lockup watchdog. The flag is part of the pvclock structure that is
+shared between guest and host, specifically the second bit of the flags
field of the pvclock_vcpu_time_info structure. It will be set exclusively by
the host and read/cleared exclusively by the guest. The guest operation of
-checking and clearing the flag must an atomic operation so
+checking and clearing the flag must be an atomic operation so
load-link/store-conditional, or equivalent must be used. There are two cases
where the guest will clear the flag: when the soft lockup watchdog timer resets
itself or when a soft lockup is detected. This ioctl can be called any time
diff --git a/Documentation/virt/kvm/arm/pvtime.rst b/Documentation/virt/kvm/arm/pvtime.rst
index 2357dd2..687b60d 100644
--- a/Documentation/virt/kvm/arm/pvtime.rst
+++ b/Documentation/virt/kvm/arm/pvtime.rst
@@ -76,5 +76,5 @@
these structures and not used for other purposes, this enables the guest to map
the region using 64k pages and avoids conflicting attributes with other memory.
-For the user space interface see Documentation/virt/kvm/devices/vcpu.txt
+For the user space interface see Documentation/virt/kvm/devices/vcpu.rst
section "3. GROUP: KVM_ARM_VCPU_PVTIME_CTRL".
diff --git a/Documentation/virt/kvm/devices/vcpu.rst b/Documentation/virt/kvm/devices/vcpu.rst
index 9963e68..ca374d3 100644
--- a/Documentation/virt/kvm/devices/vcpu.rst
+++ b/Documentation/virt/kvm/devices/vcpu.rst
@@ -110,5 +110,5 @@
Specifies the base address of the stolen time structure for this VCPU. The
base address must be 64 byte aligned and exist within a valid guest memory
-region. See Documentation/virt/kvm/arm/pvtime.txt for more information
+region. See Documentation/virt/kvm/arm/pvtime.rst for more information
including the layout of the stolen time structure.
diff --git a/Documentation/virt/kvm/hypercalls.rst b/Documentation/virt/kvm/hypercalls.rst
index dbaf207..ed4fddd 100644
--- a/Documentation/virt/kvm/hypercalls.rst
+++ b/Documentation/virt/kvm/hypercalls.rst
@@ -22,7 +22,7 @@
number in R1.
For further information on the S390 diagnose call as supported by KVM,
- refer to Documentation/virt/kvm/s390-diag.txt.
+ refer to Documentation/virt/kvm/s390-diag.rst.
PowerPC:
It uses R3-R10 and hypercall number in R11. R4-R11 are used as output registers.
@@ -30,7 +30,7 @@
KVM hypercalls uses 4 byte opcode, that are patched with 'hypercall-instructions'
property inside the device tree's /hypervisor node.
- For more information refer to Documentation/virt/kvm/ppc-pv.txt
+ For more information refer to Documentation/virt/kvm/ppc-pv.rst
MIPS:
KVM hypercalls use the HYPCALL instruction with code 0 and the hypercall
diff --git a/Documentation/virt/kvm/mmu.rst b/Documentation/virt/kvm/mmu.rst
index 6098188..46126ec 100644
--- a/Documentation/virt/kvm/mmu.rst
+++ b/Documentation/virt/kvm/mmu.rst
@@ -319,7 +319,7 @@
- If both P bit and R/W bit of error code are set, this could possibly
be handled as a "fast page fault" (fixed without taking the MMU lock). See
- the description in Documentation/virt/kvm/locking.txt.
+ the description in Documentation/virt/kvm/locking.rst.
- if needed, walk the guest page tables to determine the guest translation
(gva->gpa or ngpa->gpa)
diff --git a/Documentation/virt/kvm/review-checklist.rst b/Documentation/virt/kvm/review-checklist.rst
index 1f86a9d3..dc01aea 100644
--- a/Documentation/virt/kvm/review-checklist.rst
+++ b/Documentation/virt/kvm/review-checklist.rst
@@ -10,7 +10,7 @@
2. Patches should be against kvm.git master branch.
3. If the patch introduces or modifies a new userspace API:
- - the API must be documented in Documentation/virt/kvm/api.txt
+ - the API must be documented in Documentation/virt/kvm/api.rst
- the API must be discoverable using KVM_CHECK_EXTENSION
4. New state must include support for save/restore.
diff --git a/Documentation/vm/index.rst b/Documentation/vm/index.rst
index e8d943b..611140f 100644
--- a/Documentation/vm/index.rst
+++ b/Documentation/vm/index.rst
@@ -31,6 +31,7 @@
active_mm
balance
cleancache
+ free_page_reporting
frontswap
highmem
hmm
diff --git a/Documentation/vm/page_frags.rst b/Documentation/vm/page_frags.rst
index 637cc49..7d6f938 100644
--- a/Documentation/vm/page_frags.rst
+++ b/Documentation/vm/page_frags.rst
@@ -26,7 +26,7 @@
The network stack uses two separate caches per CPU to handle fragment
allocation. The netdev_alloc_cache is used by callers making use of the
-__netdev_alloc_frag and __netdev_alloc_skb calls. The napi_alloc_cache is
+netdev_alloc_frag and __netdev_alloc_skb calls. The napi_alloc_cache is
used by callers of the __napi_alloc_frag and __napi_alloc_skb calls. The
main difference between these two calls is the context in which they may be
called. The "netdev" prefixed functions are usable in any context as these
diff --git a/Documentation/vm/zswap.rst b/Documentation/vm/zswap.rst
index f8c6a79..d8d9fa4 100644
--- a/Documentation/vm/zswap.rst
+++ b/Documentation/vm/zswap.rst
@@ -140,10 +140,10 @@
special parameter has been introduced to implement a sort of hysteresis to
refuse taking pages into zswap pool until it has sufficient space if the limit
has been hit. To set the threshold at which zswap would start accepting pages
-again after it became full, use the sysfs ``accept_threhsold_percent``
+again after it became full, use the sysfs ``accept_threshold_percent``
attribute, e. g.::
- echo 80 > /sys/module/zswap/parameters/accept_threhsold_percent
+ echo 80 > /sys/module/zswap/parameters/accept_threshold_percent
Setting this parameter to 100 will disable the hysteresis.
diff --git a/Documentation/watchdog/convert_drivers_to_kernel_api.rst b/Documentation/watchdog/convert_drivers_to_kernel_api.rst
index dd934cc..a1c3f03 100644
--- a/Documentation/watchdog/convert_drivers_to_kernel_api.rst
+++ b/Documentation/watchdog/convert_drivers_to_kernel_api.rst
@@ -2,7 +2,7 @@
Converting old watchdog drivers to the watchdog framework
=========================================================
-by Wolfram Sang <w.sang@pengutronix.de>
+by Wolfram Sang <wsa@kernel.org>
Before the watchdog framework came into the kernel, every driver had to
implement the API on its own. Now, as the framework factored out the common
@@ -115,7 +115,7 @@
---------------------------
All possible callbacks are defined in 'struct watchdog_ops'. You can find it
-explained in 'watchdog-kernel-api.txt' in this directory. start(), stop() and
+explained in 'watchdog-kernel-api.txt' in this directory. start() and
owner must be set, the rest are optional. You will easily find corresponding
functions in the old driver. Note that you will now get a pointer to the
watchdog_device as a parameter to these functions, so you probably have to
diff --git a/Documentation/watchdog/watchdog-kernel-api.rst b/Documentation/watchdog/watchdog-kernel-api.rst
index 864edbe..068a55e 100644
--- a/Documentation/watchdog/watchdog-kernel-api.rst
+++ b/Documentation/watchdog/watchdog-kernel-api.rst
@@ -123,8 +123,8 @@
struct module *owner;
/* mandatory operations */
int (*start)(struct watchdog_device *);
- int (*stop)(struct watchdog_device *);
/* optional operations */
+ int (*stop)(struct watchdog_device *);
int (*ping)(struct watchdog_device *);
unsigned int (*status)(struct watchdog_device *);
int (*set_timeout)(struct watchdog_device *, unsigned int);
diff --git a/Documentation/x86/x86_64/uefi.rst b/Documentation/x86/x86_64/uefi.rst
index 88c3ba3..3b89410 100644
--- a/Documentation/x86/x86_64/uefi.rst
+++ b/Documentation/x86/x86_64/uefi.rst
@@ -36,7 +36,7 @@
elilo bootloader with x86_64 support, elilo configuration file,
kernel image built in first step and corresponding
- initrd. Instructions on building elilo and its dependencies
+ initrd. Instructions on building elilo and its dependencies
can be found in the elilo sourceforge project.
- Boot to EFI shell and invoke elilo choosing the kernel image built
diff --git a/MAINTAINERS b/MAINTAINERS
index 47341fb..ca99126 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -3742,7 +3742,7 @@
M: David Howells <dhowells@redhat.com>
L: linux-cachefs@redhat.com (moderated for non-subscribers)
S: Supported
-F: Documentation/filesystems/caching/cachefiles.txt
+F: Documentation/filesystems/caching/cachefiles.rst
F: fs/cachefiles/
CADENCE MIPI-CSI2 BRIDGES
@@ -4219,7 +4219,7 @@
L: codalist@coda.cs.cmu.edu
S: Maintained
W: http://www.coda.cs.cmu.edu/
-F: Documentation/filesystems/coda.txt
+F: Documentation/filesystems/coda.rst
F: fs/coda/
F: include/linux/coda*.h
F: include/uapi/linux/coda*.h
@@ -5012,7 +5012,7 @@
R: Amir Goldstein <amir73il@gmail.com>
L: linux-fsdevel@vger.kernel.org
S: Maintained
-F: Documentation/filesystems/dnotify.txt
+F: Documentation/filesystems/dnotify.rst
F: fs/notify/dnotify/
F: include/linux/dnotify.h
@@ -5026,7 +5026,7 @@
DISKQUOTA
M: Jan Kara <jack@suse.com>
S: Maintained
-F: Documentation/filesystems/quota.txt
+F: Documentation/filesystems/quota.rst
F: fs/quota/
F: include/linux/quota*.h
F: include/uapi/linux/quota*.h
@@ -7040,13 +7040,13 @@
L: linux-kernel@vger.kernel.org
S: Maintained
T: git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking/core
-F: Documentation/*futex*
+F: Documentation/locking/*futex*
F: include/asm-generic/futex.h
F: include/linux/futex.h
F: include/uapi/linux/futex.h
F: kernel/futex.c
F: tools/perf/bench/futex*
-F: tools/testing/selftests/futex/
+F: Documentation/locking/*futex*
GATEWORKS SYSTEM CONTROLLER (GSC) DRIVER
M: Tim Harvey <tharvey@gateworks.com>
@@ -7527,7 +7527,7 @@
S: Maintained
T: git git://git.kernel.org/pub/scm/linux/kernel/git/andersson/remoteproc.git hwspinlock-next
F: Documentation/devicetree/bindings/hwlock/
-F: Documentation/hwspinlock.txt
+F: Documentation/locking/hwspinlock.rst
F: drivers/hwspinlock/
F: include/linux/hwspinlock.h
@@ -8934,7 +8934,7 @@
L: openipmi-developer@lists.sourceforge.net (moderated for non-subscribers)
S: Supported
W: http://openipmi.sourceforge.net/
-F: Documentation/IPMI.txt
+F: Documentation/driver-api/ipmi.rst
F: Documentation/devicetree/bindings/ipmi/
F: drivers/char/ipmi/
F: include/linux/ipmi*
@@ -8976,7 +8976,7 @@
M: Marc Zyngier <maz@kernel.org>
S: Maintained
T: git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git irq/core
-F: Documentation/IRQ-domain.txt
+F: Documentation/core-api/irq/irq-domain.rst
F: include/linux/irqdomain.h
F: kernel/irq/irqdomain.c
F: kernel/irq/msi.c
@@ -15703,7 +15703,7 @@
F: include/linux/ssb/
SONY IMX214 SENSOR DRIVER
-M: Ricardo Ribalda <ricardo.ribalda@gmail.com>
+M: Ricardo Ribalda <ribalda@kernel.org>
L: linux-media@vger.kernel.org
S: Maintained
T: git git://linuxtv.org/media_tree.git
@@ -15943,7 +15943,7 @@
L: linuxppc-dev@lists.ozlabs.org
S: Supported
W: http://www.ibm.com/developerworks/power/cell/
-F: Documentation/filesystems/spufs.txt
+F: Documentation/filesystems/spufs/spufs.rst
F: arch/powerpc/platforms/cell/spufs/
SQUASHFS FILE SYSTEM
@@ -16690,7 +16690,7 @@
F: sound/soc/ti/
TEXAS INSTRUMENTS' DAC7612 DAC DRIVER
-M: Ricardo Ribalda <ricardo@ribalda.com>
+M: Ricardo Ribalda <ribalda@kernel.org>
L: linux-iio@vger.kernel.org
S: Supported
F: Documentation/devicetree/bindings/iio/dac/ti,dac7612.txt
@@ -18594,8 +18594,8 @@
T: git git://git.kernel.org/pub/scm/fs/xfs/xfs-linux.git
F: Documentation/ABI/testing/sysfs-fs-xfs
F: Documentation/admin-guide/xfs.rst
-F: Documentation/filesystems/xfs-delayed-logging-design.txt
-F: Documentation/filesystems/xfs-self-describing-metadata.txt
+F: Documentation/filesystems/xfs-delayed-logging-design.rst
+F: Documentation/filesystems/xfs-self-describing-metadata.rst
F: fs/xfs/
F: include/uapi/linux/dqblk_xfs.h
F: include/uapi/linux/fsmap.h
diff --git a/arch/powerpc/include/uapi/asm/kvm_para.h b/arch/powerpc/include/uapi/asm/kvm_para.h
index be48c22..a809b1b 100644
--- a/arch/powerpc/include/uapi/asm/kvm_para.h
+++ b/arch/powerpc/include/uapi/asm/kvm_para.h
@@ -31,7 +31,7 @@
* Struct fields are always 32 or 64 bit aligned, depending on them being 32
* or 64 bit wide respectively.
*
- * See Documentation/virt/kvm/ppc-pv.txt
+ * See Documentation/virt/kvm/ppc-pv.rst
*/
struct kvm_vcpu_arch_shared {
__u64 scratch1;
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 8071952..fd59fee 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3586,7 +3586,7 @@ static bool fast_page_fault(struct kvm_vcpu *vcpu, gpa_t cr2_or_gpa,
/*
* Currently, fast page fault only works for direct mapping
* since the gfn is not stable for indirect shadow page. See
- * Documentation/virt/kvm/locking.txt to get more detail.
+ * Documentation/virt/kvm/locking.rst to get more detail.
*/
fault_handled = fast_pf_fix_direct_spte(vcpu, sp,
iterator.sptep, spte,
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index beca5f9..69361ec 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -5209,7 +5209,7 @@ void ata_link_init(struct ata_port *ap, struct ata_link *link, int pmp)
* sata_link_init_spd - Initialize link->sata_spd_limit
* @link: Link to configure sata_spd_limit for
*
- * Initialize @link->[hw_]sata_spd_limit to the currently
+ * Initialize ``link->[hw_]sata_spd_limit`` to the currently
* configured value.
*
* LOCKING:
diff --git a/drivers/base/core.c b/drivers/base/core.c
index 0cad34f..57562e0 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1393,7 +1393,7 @@ static void device_release(struct kobject *kobj)
else if (dev->class && dev->class->dev_release)
dev->class->dev_release(dev);
else
- WARN(1, KERN_ERR "Device '%s' does not have a release() function, it is broken and must be fixed. See Documentation/kobject.txt.\n",
+ WARN(1, KERN_ERR "Device '%s' does not have a release() function, it is broken and must be fixed. See Documentation/core-api/kobject.rst.\n",
dev_name(dev));
kfree(p);
}
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index b27d0f6..615c6b0 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -147,7 +147,8 @@ EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource_byname);
* request_irq() APIs. This is the same as platform_get_irq(), except that it
* does not print an error message if an IRQ can not be obtained.
*
- * Example:
+ * For example::
+ *
* int irq = platform_get_irq_optional(pdev, 0);
* if (irq < 0)
* return irq;
@@ -226,7 +227,8 @@ EXPORT_SYMBOL_GPL(platform_get_irq_optional);
* IRQ fails. Device drivers should check the return value for errors so as to
* not pass a negative integer value to the request_irq() APIs.
*
- * Example:
+ * For example::
+ *
* int irq = platform_get_irq(pdev, 0);
* if (irq < 0)
* return irq;
diff --git a/drivers/char/ipmi/Kconfig b/drivers/char/ipmi/Kconfig
index 7dc2c3e..07847d9 100644
--- a/drivers/char/ipmi/Kconfig
+++ b/drivers/char/ipmi/Kconfig
@@ -14,7 +14,7 @@
IPMI is a standard for managing sensors (temperature,
voltage, etc.) in a system.
- See <file:Documentation/IPMI.txt> for more details on the driver.
+ See <file:Documentation/driver-api/ipmi.rst> for more details on the driver.
If unsure, say N.
diff --git a/drivers/char/ipmi/ipmi_si_hotmod.c b/drivers/char/ipmi/ipmi_si_hotmod.c
index 42a925f..4fbb4e1 100644
--- a/drivers/char/ipmi/ipmi_si_hotmod.c
+++ b/drivers/char/ipmi/ipmi_si_hotmod.c
@@ -18,7 +18,7 @@ static int hotmod_handler(const char *val, const struct kernel_param *kp);
module_param_call(hotmod, hotmod_handler, NULL, NULL, 0200);
MODULE_PARM_DESC(hotmod, "Add and remove interfaces. See"
- " Documentation/IPMI.txt in the kernel sources for the"
+ " Documentation/driver-api/ipmi.rst in the kernel sources for the"
" gory details.");
/*
diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index c7cc853..77b8d55 100644
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -968,7 +968,7 @@ static inline bool ipmi_thread_busy_wait(enum si_sm_result smi_result,
* that are not BT and do not have interrupts. It starts spinning
* when an operation is complete or until max_busy tells it to stop
* (if that is enabled). See the paragraph on kimid_max_busy_us in
- * Documentation/IPMI.txt for details.
+ * Documentation/driver-api/ipmi.rst for details.
*/
static int ipmi_thread(void *data)
{
diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c
index a5fd897..a6abb70 100644
--- a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c
+++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c
@@ -8,7 +8,7 @@
* This file add support for AES cipher with 128,192,256 bits keysize in
* CBC and ECB mode.
*
- * You could find a link for the datasheet in Documentation/arm/sunxi/README
+ * You could find a link for the datasheet in Documentation/arm/sunxi.rst
*/
#include <linux/crypto.h>
diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-core.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-core.c
index 3e4e4bb..b957061 100644
--- a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-core.c
+++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-core.c
@@ -7,7 +7,7 @@
*
* Core file which registers crypto algorithms supported by the CryptoEngine.
*
- * You could find a link for the datasheet in Documentation/arm/sunxi/README
+ * You could find a link for the datasheet in Documentation/arm/sunxi.rst
*/
#include <linux/clk.h>
#include <linux/crypto.h>
diff --git a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c
index 84d52fc..c89cb2e 100644
--- a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c
+++ b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-cipher.c
@@ -8,7 +8,7 @@
* This file add support for AES cipher with 128,192,256 bits keysize in
* CBC and ECB mode.
*
- * You could find a link for the datasheet in Documentation/arm/sunxi/README
+ * You could find a link for the datasheet in Documentation/arm/sunxi.rst
*/
#include <linux/crypto.h>
diff --git a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-core.c b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-core.c
index a1fb2fb..5d9d0fe 100644
--- a/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-core.c
+++ b/drivers/crypto/allwinner/sun8i-ss/sun8i-ss-core.c
@@ -7,7 +7,7 @@
*
* Core file which registers crypto algorithms supported by the SecuritySystem
*
- * You could find a link for the datasheet in Documentation/arm/sunxi/README
+ * You could find a link for the datasheet in Documentation/arm/sunxi.rst
*/
#include <linux/clk.h>
#include <linux/crypto.h>
diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
index 4359497..fb92be7e 100644
--- a/drivers/gpu/drm/Kconfig
+++ b/drivers/gpu/drm/Kconfig
@@ -161,7 +161,7 @@
monitor are unable to provide appropriate EDID data. Since this
feature is provided as a workaround for broken hardware, the
default case is N. Details and instructions how to build your own
- EDID data are given in Documentation/driver-api/edid.rst.
+ EDID data are given in Documentation/admin-guide/edid.rst.
config DRM_DP_CEC
bool "Enable DisplayPort CEC-Tunneling-over-AUX HDMI support"
diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index 9e41972..c2b8d2a 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -741,7 +741,7 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
* };
*
* Please make sure that you follow all the best practices from
- * ``Documentation/ioctl/botching-up-ioctls.rst``. Note that drm_ioctl()
+ * ``Documentation/process/botching-up-ioctls.rst``. Note that drm_ioctl()
* automatically zero-extends structures, hence make sure you can add more stuff
* at the end, i.e. don't put a variable sized array there.
*
diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
index 211f5de9..9aba291 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_kms.h
@@ -170,7 +170,7 @@ struct dpu_global_state
*
* Main debugfs documentation is located at,
*
- * Documentation/filesystems/debugfs.txt
+ * Documentation/filesystems/debugfs.rst
*
* @dpu_debugfs_setup_regset32: Initialize data for dpu_debugfs_create_regset32
* @dpu_debugfs_create_regset32: Create 32-bit register dump file
diff --git a/drivers/hwtracing/coresight/Kconfig b/drivers/hwtracing/coresight/Kconfig
index 83e841b..02dbb5c 100644
--- a/drivers/hwtracing/coresight/Kconfig
+++ b/drivers/hwtracing/coresight/Kconfig
@@ -107,7 +107,7 @@
can quickly get to know program counter (PC), secure state,
exception level, etc. Before use debugging functionality, platform
needs to ensure the clock domain and power domain are enabled
- properly, please refer Documentation/trace/coresight-cpu-debug.rst
+ properly, please refer Documentation/trace/coresight/coresight-cpu-debug.rst
for detailed description and the example for usage.
config CORESIGHT_CTI
diff --git a/drivers/iio/dac/ad5761.c b/drivers/iio/dac/ad5761.c
index 4fb42b7..7468fbd1 100644
--- a/drivers/iio/dac/ad5761.c
+++ b/drivers/iio/dac/ad5761.c
@@ -3,7 +3,7 @@
* AD5721, AD5721R, AD5761, AD5761R, Voltage Output Digital to Analog Converter
*
* Copyright 2016 Qtechnology A/S
- * 2016 Ricardo Ribalda <ricardo.ribalda@gmail.com>
+ * 2016 Ricardo Ribalda <ribalda@kernel.org>
*/
#include <linux/kernel.h>
#include <linux/module.h>
@@ -423,6 +423,6 @@ static struct spi_driver ad5761_driver = {
};
module_spi_driver(ad5761_driver);
-MODULE_AUTHOR("Ricardo Ribalda <ricardo.ribalda@gmail.com>");
+MODULE_AUTHOR("Ricardo Ribalda <ribalda@kernel.org>");
MODULE_DESCRIPTION("Analog Devices AD5721, AD5721R, AD5761, AD5761R driver");
MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/dac/ti-dac7612.c b/drivers/iio/dac/ti-dac7612.c
index c468051..de0c657 100644
--- a/drivers/iio/dac/ti-dac7612.c
+++ b/drivers/iio/dac/ti-dac7612.c
@@ -3,7 +3,7 @@
* DAC7612 Dual, 12-Bit Serial input Digital-to-Analog Converter
*
* Copyright 2019 Qtechnology A/S
- * 2019 Ricardo Ribalda <ricardo@ribalda.com>
+ * 2019 Ricardo Ribalda <ribalda@kernel.org>
*
* Licensed under the GPL-2.
*/
@@ -179,6 +179,6 @@ static struct spi_driver dac7612_driver = {
};
module_spi_driver(dac7612_driver);
-MODULE_AUTHOR("Ricardo Ribalda <ricardo@ribalda.com>");
+MODULE_AUTHOR("Ricardo Ribalda <ribalda@kernel.org>");
MODULE_DESCRIPTION("Texas Instruments DAC7612 DAC driver");
MODULE_LICENSE("GPL v2");
diff --git a/drivers/leds/leds-pca963x.c b/drivers/leds/leds-pca963x.c
index 66cdc00..d288acb 100644
--- a/drivers/leds/leds-pca963x.c
+++ b/drivers/leds/leds-pca963x.c
@@ -4,7 +4,7 @@
* Copyright 2013 Qtechnology/AS
*
* Author: Peter Meerwald <p.meerwald@bct-electronic.com>
- * Author: Ricardo Ribalda <ricardo.ribalda@gmail.com>
+ * Author: Ricardo Ribalda <ribalda@kernel.org>
*
* Based on leds-pca955x.c
*
diff --git a/drivers/media/i2c/imx214.c b/drivers/media/i2c/imx214.c
index 4175d06..1ef5af9 100644
--- a/drivers/media/i2c/imx214.c
+++ b/drivers/media/i2c/imx214.c
@@ -4,7 +4,7 @@
*
* Copyright 2018 Qtechnology A/S
*
- * Ricardo Ribalda <ricardo.ribalda@gmail.com>
+ * Ricardo Ribalda <ribalda@kernel.org>
*/
#include <linux/clk.h>
#include <linux/delay.h>
@@ -1120,5 +1120,5 @@ static struct i2c_driver imx214_i2c_driver = {
module_i2c_driver(imx214_i2c_driver);
MODULE_DESCRIPTION("Sony IMX214 Camera driver");
-MODULE_AUTHOR("Ricardo Ribalda <ricardo.ribalda@gmail.com>");
+MODULE_AUTHOR("Ricardo Ribalda <ribalda@kernel.org>");
MODULE_LICENSE("GPL v2");
diff --git a/drivers/media/v4l2-core/v4l2-fwnode.c b/drivers/media/v4l2-core/v4l2-fwnode.c
index 97f0f8b..8a1e1b9 100644
--- a/drivers/media/v4l2-core/v4l2-fwnode.c
+++ b/drivers/media/v4l2-core/v4l2-fwnode.c
@@ -980,7 +980,7 @@ static int v4l2_fwnode_reference_parse(struct device *dev,
*
* THIS EXAMPLE EXISTS MERELY TO DOCUMENT THIS FUNCTION. DO NOT USE IT AS A
* REFERENCE IN HOW ACPI TABLES SHOULD BE WRITTEN!! See documentation under
- * Documentation/acpi/dsd instead and especially graph.txt,
+ * Documentation/firmware-guide/acpi/dsd/ instead and especially graph.txt,
* data-node-references.txt and leds.txt .
*
* Scope (\_SB.PCI0.I2C2)
diff --git a/fs/Kconfig b/fs/Kconfig
index f08fbbf..d1ad393 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -166,7 +166,7 @@
space. If you unmount a tmpfs instance, everything stored therein is
lost.
- See <file:Documentation/filesystems/tmpfs.txt> for details.
+ See <file:Documentation/filesystems/tmpfs.rst> for details.
config TMPFS_POSIX_ACL
bool "Tmpfs POSIX Access Control Lists"
diff --git a/fs/Kconfig.binfmt b/fs/Kconfig.binfmt
index 2358368..04f86b8 100644
--- a/fs/Kconfig.binfmt
+++ b/fs/Kconfig.binfmt
@@ -78,7 +78,7 @@
The core dump behavior can be controlled per process using
the /proc/PID/coredump_filter pseudo-file; this setting is
- inherited. See Documentation/filesystems/proc.txt for details.
+ inherited. See Documentation/filesystems/proc.rst for details.
This config option changes the default setting of coredump_filter
seen at boot time. If unsure, say Y.
diff --git a/fs/adfs/Kconfig b/fs/adfs/Kconfig
index df4650d..44738fe 100644
--- a/fs/adfs/Kconfig
+++ b/fs/adfs/Kconfig
@@ -12,7 +12,7 @@
The ADFS partition should be the first partition (i.e.,
/dev/[hs]d?1) on each of your drives. Please read the file
- <file:Documentation/filesystems/adfs.txt> for further details.
+ <file:Documentation/filesystems/adfs.rst> for further details.
To compile this code as a module, choose M here: the module will be
called adfs.
diff --git a/fs/affs/Kconfig b/fs/affs/Kconfig
index 84c46b9..eb9d0ab 100644
--- a/fs/affs/Kconfig
+++ b/fs/affs/Kconfig
@@ -9,7 +9,7 @@
FFS partition on your hard drive. Amiga floppies however cannot be
read with this driver due to an incompatibility of the floppy
controller used in an Amiga and the standard floppy controller in
- PCs and workstations. Read <file:Documentation/filesystems/affs.txt>
+ PCs and workstations. Read <file:Documentation/filesystems/affs.rst>
and <file:fs/affs/Changes>.
With this driver you can also mount disk files used by Bernd
diff --git a/fs/afs/Kconfig b/fs/afs/Kconfig
index 3fb1f55..1ad211d 100644
--- a/fs/afs/Kconfig
+++ b/fs/afs/Kconfig
@@ -8,7 +8,7 @@
If you say Y here, you will get an experimental Andrew File System
driver. It currently only supports unsecured read-only AFS access.
- See <file:Documentation/filesystems/afs.txt> for more information.
+ See <file:Documentation/filesystems/afs.rst> for more information.
If unsure, say N.
@@ -18,7 +18,7 @@
help
Say Y here to make runtime controllable debugging messages appear.
- See <file:Documentation/filesystems/afs.txt> for more information.
+ See <file:Documentation/filesystems/afs.rst> for more information.
If unsure, say N.
@@ -37,6 +37,6 @@
the dmesg log if the server rotation algorithm fails to successfully
contact a server.
- See <file:Documentation/filesystems/afs.txt> for more information.
+ See <file:Documentation/filesystems/afs.rst> for more information.
If unsure, say N.
diff --git a/fs/bfs/Kconfig b/fs/bfs/Kconfig
index 3e1247f..3a75780 100644
--- a/fs/bfs/Kconfig
+++ b/fs/bfs/Kconfig
@@ -11,7 +11,7 @@
on your /stand slice from within Linux. You then also need to say Y
to "UnixWare slices support", below. More information about the BFS
file system is contained in the file
- <file:Documentation/filesystems/bfs.txt>.
+ <file:Documentation/filesystems/bfs.rst>.
If you don't know what this is about, say N.
diff --git a/fs/cachefiles/Kconfig b/fs/cachefiles/Kconfig
index ae559ed..ff9ca55 100644
--- a/fs/cachefiles/Kconfig
+++ b/fs/cachefiles/Kconfig
@@ -8,7 +8,7 @@
filesystems - primarily networking filesystems - thus allowing fast
local disk to enhance the speed of slower devices.
- See Documentation/filesystems/caching/cachefiles.txt for more
+ See Documentation/filesystems/caching/cachefiles.rst for more
information.
config CACHEFILES_DEBUG
@@ -36,5 +36,5 @@
bouncing between CPUs. On the other hand, the histogram may be
useful for debugging purposes. Saying 'N' here is recommended.
- See Documentation/filesystems/caching/cachefiles.txt for more
+ See Documentation/filesystems/caching/cachefiles.rst for more
information.
diff --git a/fs/coda/Kconfig b/fs/coda/Kconfig
index ae6759f..c3477ee 100644
--- a/fs/coda/Kconfig
+++ b/fs/coda/Kconfig
@@ -15,7 +15,7 @@
*client*. You will need user level code as well, both for the
client and server. Servers are currently user level, i.e. they need
no kernel support. Please read
- <file:Documentation/filesystems/coda.txt> and check out the Coda
+ <file:Documentation/filesystems/coda.rst> and check out the Coda
home page <http://www.coda.cs.cmu.edu/>.
To compile the coda client support as a module, choose M here: the
diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c
index fd0b5dd..8bd6a88 100644
--- a/fs/configfs/inode.c
+++ b/fs/configfs/inode.c
@@ -9,7 +9,7 @@
*
* configfs Copyright (C) 2005 Oracle. All rights reserved.
*
- * Please see Documentation/filesystems/configfs/configfs.txt for more
+ * Please see Documentation/filesystems/configfs.rst for more
* information.
*/
diff --git a/fs/configfs/item.c b/fs/configfs/item.c
index 6e0f1fc..704a435 100644
--- a/fs/configfs/item.c
+++ b/fs/configfs/item.c
@@ -9,7 +9,7 @@
*
* configfs Copyright (C) 2005 Oracle. All rights reserved.
*
- * Please see the file Documentation/filesystems/configfs/configfs.txt for
+ * Please see the file Documentation/filesystems/configfs.rst for
* critical information about using the config_item interface.
*/
diff --git a/fs/cramfs/Kconfig b/fs/cramfs/Kconfig
index c8bebb7..d98cef0 100644
--- a/fs/cramfs/Kconfig
+++ b/fs/cramfs/Kconfig
@@ -9,7 +9,7 @@
limited to 256MB file systems (with 16MB files), and doesn't support
16/32 bits uid/gid, hard links and timestamps.
- See <file:Documentation/filesystems/cramfs.txt> and
+ See <file:Documentation/filesystems/cramfs.rst> and
<file:fs/cramfs/README> for further information.
To compile this as a module, choose M here: the module will be called
diff --git a/fs/ecryptfs/Kconfig b/fs/ecryptfs/Kconfig
index 522c35d..1bdeaa6 100644
--- a/fs/ecryptfs/Kconfig
+++ b/fs/ecryptfs/Kconfig
@@ -7,7 +7,7 @@
select CRYPTO_MD5
help
Encrypted filesystem that operates on the VFS layer. See
- <file:Documentation/filesystems/ecryptfs.txt> to learn more about
+ <file:Documentation/filesystems/ecryptfs.rst> to learn more about
eCryptfs. Userspace components are required and can be
obtained from <http://ecryptfs.sf.net>.
diff --git a/fs/fat/Kconfig b/fs/fat/Kconfig
index 718163d..ca31993 100644
--- a/fs/fat/Kconfig
+++ b/fs/fat/Kconfig
@@ -69,7 +69,7 @@
The VFAT support enlarges your kernel by about 10 KB and it only
works if you said Y to the "DOS FAT fs support" above. Please read
- the file <file:Documentation/filesystems/vfat.txt> for details. If
+ the file <file:Documentation/filesystems/vfat.rst> for details. If
unsure, say Y.
To compile this as a module, choose M here: the module will be called
@@ -82,7 +82,7 @@
help
This option should be set to the codepage of your FAT filesystems.
It can be overridden with the "codepage" mount option.
- See <file:Documentation/filesystems/vfat.txt> for more information.
+ See <file:Documentation/filesystems/vfat.rst> for more information.
config FAT_DEFAULT_IOCHARSET
string "Default iocharset for FAT"
@@ -96,7 +96,7 @@
Note that "utf8" is not recommended for FAT filesystems.
If unsure, you shouldn't set "utf8" here - select the next option
instead if you would like to use UTF-8 encoded file names by default.
- See <file:Documentation/filesystems/vfat.txt> for more information.
+ See <file:Documentation/filesystems/vfat.rst> for more information.
Enable any character sets you need in File Systems/Native Language
Support.
@@ -114,4 +114,4 @@
Say Y if you use UTF-8 encoding for file names, N otherwise.
- See <file:Documentation/filesystems/vfat.txt> for more information.
+ See <file:Documentation/filesystems/vfat.rst> for more information.
diff --git a/fs/fscache/Kconfig b/fs/fscache/Kconfig
index 506c5e6..5e796e6 100644
--- a/fs/fscache/Kconfig
+++ b/fs/fscache/Kconfig
@@ -8,7 +8,7 @@
Different sorts of caches can be plugged in, depending on the
resources available.
- See Documentation/filesystems/caching/fscache.txt for more information.
+ See Documentation/filesystems/caching/fscache.rst for more information.
config FSCACHE_STATS
bool "Gather statistical information on local caching"
@@ -25,7 +25,7 @@
between CPUs. On the other hand, the stats are very useful for
debugging purposes. Saying 'Y' here is recommended.
- See Documentation/filesystems/caching/fscache.txt for more information.
+ See Documentation/filesystems/caching/fscache.rst for more information.
config FSCACHE_HISTOGRAM
bool "Gather latency information on local caching"
@@ -42,7 +42,7 @@
bouncing between CPUs. On the other hand, the histogram may be
useful for debugging purposes. Saying 'N' here is recommended.
- See Documentation/filesystems/caching/fscache.txt for more information.
+ See Documentation/filesystems/caching/fscache.rst for more information.
config FSCACHE_DEBUG
bool "Debug FS-Cache"
@@ -52,7 +52,7 @@
management module. If this is set, the debugging output may be
enabled by setting bits in /sys/modules/fscache/parameter/debug.
- See Documentation/filesystems/caching/fscache.txt for more information.
+ See Documentation/filesystems/caching/fscache.rst for more information.
config FSCACHE_OBJECT_LIST
bool "Maintain global object list for debugging purposes"
diff --git a/fs/fscache/cache.c b/fs/fscache/cache.c
index f78793f..fcc1363 100644
--- a/fs/fscache/cache.c
+++ b/fs/fscache/cache.c
@@ -172,7 +172,7 @@ struct fscache_cache *fscache_select_cache_for_object(
*
* Initialise a record of a cache and fill in the name.
*
- * See Documentation/filesystems/caching/backend-api.txt for a complete
+ * See Documentation/filesystems/caching/backend-api.rst for a complete
* description.
*/
void fscache_init_cache(struct fscache_cache *cache,
@@ -207,7 +207,7 @@ EXPORT_SYMBOL(fscache_init_cache);
*
* Add a cache to the system, making it available for netfs's to use.
*
- * See Documentation/filesystems/caching/backend-api.txt for a complete
+ * See Documentation/filesystems/caching/backend-api.rst for a complete
* description.
*/
int fscache_add_cache(struct fscache_cache *cache,
@@ -307,7 +307,7 @@ EXPORT_SYMBOL(fscache_add_cache);
* Note that an I/O error occurred in a cache and that it should no longer be
* used for anything. This also reports the error into the kernel log.
*
- * See Documentation/filesystems/caching/backend-api.txt for a complete
+ * See Documentation/filesystems/caching/backend-api.rst for a complete
* description.
*/
void fscache_io_error(struct fscache_cache *cache)
@@ -355,7 +355,7 @@ static void fscache_withdraw_all_objects(struct fscache_cache *cache,
* Withdraw a cache from service, unbinding all its cache objects from the
* netfs cookies they're currently representing.
*
- * See Documentation/filesystems/caching/backend-api.txt for a complete
+ * See Documentation/filesystems/caching/backend-api.rst for a complete
* description.
*/
void fscache_withdraw_cache(struct fscache_cache *cache)
diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c
index 0ce3965..751bc5b 100644
--- a/fs/fscache/cookie.c
+++ b/fs/fscache/cookie.c
@@ -4,7 +4,7 @@
* Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
- * See Documentation/filesystems/caching/netfs-api.txt for more information on
+ * See Documentation/filesystems/caching/netfs-api.rst for more information on
* the netfs API.
*/
diff --git a/fs/fscache/object.c b/fs/fscache/object.c
index cfeba83..cb2146e 100644
--- a/fs/fscache/object.c
+++ b/fs/fscache/object.c
@@ -4,7 +4,7 @@
* Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
- * See Documentation/filesystems/caching/object.txt for a description of the
+ * See Documentation/filesystems/caching/object.rst for a description of the
* object state machine and the in-kernel representations.
*/
@@ -295,7 +295,7 @@ static void fscache_object_work_func(struct work_struct *work)
*
* Initialise a cache object description to its basic values.
*
- * See Documentation/filesystems/caching/backend-api.txt for a complete
+ * See Documentation/filesystems/caching/backend-api.rst for a complete
* description.
*/
void fscache_object_init(struct fscache_object *object,
diff --git a/fs/fscache/operation.c b/fs/fscache/operation.c
index 1a22a55..4a5651d 100644
--- a/fs/fscache/operation.c
+++ b/fs/fscache/operation.c
@@ -4,7 +4,7 @@
* Copyright (C) 2008 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
- * See Documentation/filesystems/caching/operations.txt
+ * See Documentation/filesystems/caching/operations.rst
*/
#define FSCACHE_DEBUG_LEVEL OPERATION
diff --git a/fs/fuse/Kconfig b/fs/fuse/Kconfig
index eb2a585..774b261 100644
--- a/fs/fuse/Kconfig
+++ b/fs/fuse/Kconfig
@@ -12,7 +12,7 @@
although chances are your distribution already has that library
installed if you've installed the "fuse" package itself.
- See <file:Documentation/filesystems/fuse.txt> for more information.
+ See <file:Documentation/filesystems/fuse.rst> for more information.
See <file:Documentation/Changes> for needed library/utility version.
If you want to develop a userspace FS, or if you want to use
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index 97eec75..c7a65cf 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -2081,7 +2081,7 @@ static void end_polls(struct fuse_conn *fc)
* The same effect is usually achievable through killing the filesystem daemon
* and all users of the filesystem. The exception is the combination of an
* asynchronous request and the tricky deadlock (see
- * Documentation/filesystems/fuse.txt).
+ * Documentation/filesystems/fuse.rst).
*
* Aborting requests under I/O goes as follows: 1: Separate out unlocked
* requests, they should be finished off immediately. Locked requests will be
diff --git a/fs/hfs/Kconfig b/fs/hfs/Kconfig
index 44f6e89..129926b 100644
--- a/fs/hfs/Kconfig
+++ b/fs/hfs/Kconfig
@@ -6,7 +6,7 @@
help
If you say Y here, you will be able to mount Macintosh-formatted
floppy disks and hard drive partitions with full read-write access.
- Please read <file:Documentation/filesystems/hfs.txt> to learn about
+ Please read <file:Documentation/filesystems/hfs.rst> to learn about
the available mount options.
To compile this file system support as a module, choose M here: the
diff --git a/fs/hpfs/Kconfig b/fs/hpfs/Kconfig
index 56aa033..2b36dc6 100644
--- a/fs/hpfs/Kconfig
+++ b/fs/hpfs/Kconfig
@@ -9,7 +9,7 @@
write files to an OS/2 HPFS partition on your hard drive. OS/2
floppies however are in regular MSDOS format, so you don't need this
option in order to be able to read them. Read
- <file:Documentation/filesystems/hpfs.txt>.
+ <file:Documentation/filesystems/hpfs.rst>.
To compile this file system support as a module, choose M here: the
module will be called hpfs. If unsure, say N.
diff --git a/fs/inode.c b/fs/inode.c
index 93d9252..37226a9 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -1606,14 +1606,14 @@ EXPORT_SYMBOL(iput);
* @inode: inode owning the block number being requested
* @block: pointer containing the block to find
*
- * Replaces the value in *block with the block number on the device holding
+ * Replaces the value in ``*block`` with the block number on the device holding
* corresponding to the requested block number in the file.
* That is, asked for block 4 of inode 1 the function will replace the
- * 4 in *block, with disk block relative to the disk start that holds that
+ * 4 in ``*block``, with disk block relative to the disk start that holds that
* block of the file.
*
* Returns -EINVAL in case of error, 0 otherwise. If mapping falls into a
- * hole, returns 0 and *block is also set to 0.
+ * hole, returns 0 and ``*block`` is also set to 0.
*/
int bmap(struct inode *inode, sector_t *block)
{
diff --git a/fs/isofs/Kconfig b/fs/isofs/Kconfig
index 5e74195..08ffd37 100644
--- a/fs/isofs/Kconfig
+++ b/fs/isofs/Kconfig
@@ -8,7 +8,7 @@
long Unix filenames and symbolic links are also supported by this
driver. If you have a CD-ROM drive and want to do more with it than
just listen to audio CDs and watch its LEDs, say Y (and read
- <file:Documentation/filesystems/isofs.txt> and the CD-ROM-HOWTO,
+ <file:Documentation/filesystems/isofs.rst> and the CD-ROM-HOWTO,
available from <http://www.tldp.org/docs.html#howto>), thereby
enlarging your kernel by about 27 KB; otherwise say N.
diff --git a/fs/locks.c b/fs/locks.c
index b8a31c1..1d4f4d5 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -61,7 +61,7 @@
*
* Initial implementation of mandatory locks. SunOS turned out to be
* a rotten model, so I implemented the "obvious" semantics.
- * See 'Documentation/filesystems/mandatory-locking.txt' for details.
+ * See 'Documentation/filesystems/mandatory-locking.rst' for details.
* Andy Walker (andy@lysaker.kvaerner.no), April 06, 1996.
*
* Don't allow mandatory locks on mmap()'ed files. Added simple functions to
diff --git a/fs/namespace.c b/fs/namespace.c
index a28e4db0..5f036dc 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -3595,7 +3595,7 @@ EXPORT_SYMBOL(path_is_under);
* file system may be mounted on put_old. After all, new_root is a mountpoint.
*
* Also, the current root cannot be on the 'rootfs' (initial ramfs) filesystem.
- * See Documentation/filesystems/ramfs-rootfs-initramfs.txt for alternatives
+ * See Documentation/filesystems/ramfs-rootfs-initramfs.rst for alternatives
* in this situation.
*
* Notes:
diff --git a/fs/notify/inotify/Kconfig b/fs/notify/inotify/Kconfig
index 6736e47..7715fad 100644
--- a/fs/notify/inotify/Kconfig
+++ b/fs/notify/inotify/Kconfig
@@ -12,6 +12,6 @@
new features including multiple file events, one-shot support, and
unmount notification.
- For more information, see <file:Documentation/filesystems/inotify.txt>
+ For more information, see <file:Documentation/filesystems/inotify.rst>
If unsure, say Y.
diff --git a/fs/ntfs/Kconfig b/fs/ntfs/Kconfig
index de9fb5c..1667a7e 100644
--- a/fs/ntfs/Kconfig
+++ b/fs/ntfs/Kconfig
@@ -18,7 +18,7 @@
the Linux 2.4 kernel series is separately available as a patch
from the project web site.
- For more information see <file:Documentation/filesystems/ntfs.txt>
+ For more information see <file:Documentation/filesystems/ntfs.rst>
and <http://www.linux-ntfs.org/>.
To compile this file system support as a module, choose M here: the
diff --git a/fs/ocfs2/Kconfig b/fs/ocfs2/Kconfig
index 46bba20..1177c33 100644
--- a/fs/ocfs2/Kconfig
+++ b/fs/ocfs2/Kconfig
@@ -21,7 +21,7 @@
OCFS2 mailing lists: http://oss.oracle.com/projects/ocfs2/mailman/
For more information on OCFS2, see the file
- <file:Documentation/filesystems/ocfs2.txt>.
+ <file:Documentation/filesystems/ocfs2.rst>.
config OCFS2_FS_O2CB
tristate "O2CB Kernelspace Clustering"
diff --git a/fs/overlayfs/Kconfig b/fs/overlayfs/Kconfig
index 714c14c..dd188c7 100644
--- a/fs/overlayfs/Kconfig
+++ b/fs/overlayfs/Kconfig
@@ -9,7 +9,7 @@
'lower' filesystem is either hidden or, in the case of directories,
merged with the 'upper' object.
- For more information see Documentation/filesystems/overlayfs.txt
+ For more information see Documentation/filesystems/overlayfs.rst
config OVERLAY_FS_REDIRECT_DIR
bool "Overlayfs: turn on redirect directory feature by default"
@@ -38,7 +38,7 @@
If backward compatibility is not an issue, then it is safe and
recommended to say N here.
- For more information, see Documentation/filesystems/overlayfs.txt
+ For more information, see Documentation/filesystems/overlayfs.rst
If unsure, say Y.
@@ -103,7 +103,7 @@
If compatibility with applications that expect 32bit inodes is not an
issue, then it is safe and recommended to say Y here.
- For more information, see Documentation/filesystems/overlayfs.txt
+ For more information, see Documentation/filesystems/overlayfs.rst
If unsure, say N.
diff --git a/fs/proc/Kconfig b/fs/proc/Kconfig
index 27ef84d..971a42f 100644
--- a/fs/proc/Kconfig
+++ b/fs/proc/Kconfig
@@ -23,7 +23,7 @@
/proc" or the equivalent line in /etc/fstab does the job.
The /proc file system is explained in the file
- <file:Documentation/filesystems/proc.txt> and on the proc(5) manpage
+ <file:Documentation/filesystems/proc.rst> and on the proc(5) manpage
("man 5 proc").
This option will enlarge your kernel by about 67 KB. Several
@@ -95,7 +95,7 @@
default n
help
Provides a fast way to retrieve first level children pids of a task. See
- <file:Documentation/filesystems/proc.txt> for more information.
+ <file:Documentation/filesystems/proc.rst> for more information.
Say Y if you are running any user-space software which takes benefit from
this interface. For example, rkt is such a piece of software.
diff --git a/fs/romfs/Kconfig b/fs/romfs/Kconfig
index ad4c457..9737b8e 100644
--- a/fs/romfs/Kconfig
+++ b/fs/romfs/Kconfig
@@ -6,7 +6,7 @@
This is a very small read-only file system mainly intended for
initial ram disks of installation disks, but it could be used for
other read-only media as well. Read
- <file:Documentation/filesystems/romfs.txt> for details.
+ <file:Documentation/filesystems/romfs.rst> for details.
To compile this file system support as a module, choose M here: the
module will be called romfs. Note that the file system of your
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index aa85f28..59dffd5 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -6,7 +6,7 @@
* Copyright (c) 2007 SUSE Linux Products GmbH
* Copyright (c) 2007 Tejun Heo <teheo@suse.de>
*
- * Please see Documentation/filesystems/sysfs.txt for more information.
+ * Please see Documentation/filesystems/sysfs.rst for more information.
*/
#define pr_fmt(fmt) "sysfs: " fmt
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 26bbf96..f275fcd 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -6,7 +6,7 @@
* Copyright (c) 2007 SUSE Linux Products GmbH
* Copyright (c) 2007 Tejun Heo <teheo@suse.de>
*
- * Please see Documentation/filesystems/sysfs.txt for more information.
+ * Please see Documentation/filesystems/sysfs.rst for more information.
*/
#include <linux/module.h>
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index db81cfb..e747c135 100644
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -6,7 +6,7 @@
* Copyright (c) 2007 SUSE Linux Products GmbH
* Copyright (c) 2007 Tejun Heo <teheo@suse.de>
*
- * Please see Documentation/filesystems/sysfs.txt for more information.
+ * Please see Documentation/filesystems/sysfs.rst for more information.
*/
#include <linux/fs.h>
diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index c4deecc..5603530 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -6,7 +6,7 @@
* Copyright (c) 2007 SUSE Linux Products GmbH
* Copyright (c) 2007 Tejun Heo <teheo@suse.de>
*
- * Please see Documentation/filesystems/sysfs.txt for more information.
+ * Please see Documentation/filesystems/sysfs.rst for more information.
*/
#include <linux/fs.h>
diff --git a/fs/sysv/Kconfig b/fs/sysv/Kconfig
index d4edf7d..b4e23e0 100644
--- a/fs/sysv/Kconfig
+++ b/fs/sysv/Kconfig
@@ -28,7 +28,7 @@
tar" or preferably "info tar"). Note also that this option has
nothing whatsoever to do with the option "System V IPC". Read about
the System V file system in
- <file:Documentation/filesystems/sysv-fs.txt>.
+ <file:Documentation/filesystems/sysv-fs.rst>.
Saying Y here will enlarge your kernel by about 27 KB.
To compile this as a module, choose M here: the module will be called
diff --git a/fs/udf/Kconfig b/fs/udf/Kconfig
index 6848de5..26e1a49 100644
--- a/fs/udf/Kconfig
+++ b/fs/udf/Kconfig
@@ -9,7 +9,7 @@
compatible with standard unix file systems, it is also suitable for
removable USB disks. Say Y if you intend to mount DVD discs or CDRW's
written in packet mode, or if you want to use UDF for removable USB
- disks. Please read <file:Documentation/filesystems/udf.txt>.
+ disks. Please read <file:Documentation/filesystems/udf.rst>.
To compile this file system support as a module, choose M here: the
module will be called udf.
diff --git a/include/linux/configfs.h b/include/linux/configfs.h
index fa9490a..2e8c69b 100644
--- a/include/linux/configfs.h
+++ b/include/linux/configfs.h
@@ -13,7 +13,7 @@
*
* configfs Copyright (C) 2005 Oracle. All rights reserved.
*
- * Please read Documentation/filesystems/configfs/configfs.txt before using
+ * Please read Documentation/filesystems/configfs.rst before using
* the configfs interface, ESPECIALLY the parts about reference counts and
* item destructors.
*/
diff --git a/include/linux/fs_context.h b/include/linux/fs_context.h
index e6c3e4c..5f24fcb 100644
--- a/include/linux/fs_context.h
+++ b/include/linux/fs_context.h
@@ -85,7 +85,7 @@ struct p_log {
* Superblock creation fills in ->root whereas reconfiguration begins with this
* already set.
*
- * See Documentation/filesystems/mount_api.txt
+ * See Documentation/filesystems/mount_api.rst
*/
struct fs_context {
const struct fs_context_operations *ops;
diff --git a/include/linux/fscache-cache.h b/include/linux/fscache-cache.h
index d5ba431..ce0b5fb 100644
--- a/include/linux/fscache-cache.h
+++ b/include/linux/fscache-cache.h
@@ -6,7 +6,7 @@
*
* NOTE!!! See:
*
- * Documentation/filesystems/caching/backend-api.txt
+ * Documentation/filesystems/caching/backend-api.rst
*
* for a description of the cache backend interface declared here.
*/
@@ -454,7 +454,7 @@ static inline void fscache_object_lookup_error(struct fscache_object *object)
* Set the maximum size an object is permitted to reach, implying the highest
* byte that may be written. Intended to be called by the attr_changed() op.
*
- * See Documentation/filesystems/caching/backend-api.txt for a complete
+ * See Documentation/filesystems/caching/backend-api.rst for a complete
* description.
*/
static inline
diff --git a/include/linux/fscache.h b/include/linux/fscache.h
index ad044c0..a1c928f 100644
--- a/include/linux/fscache.h
+++ b/include/linux/fscache.h
@@ -6,7 +6,7 @@
*
* NOTE!!! See:
*
- * Documentation/filesystems/caching/netfs-api.txt
+ * Documentation/filesystems/caching/netfs-api.rst
*
* for a description of the network filesystem interface declared here.
*/
@@ -233,7 +233,7 @@ extern void __fscache_enable_cookie(struct fscache_cookie *, const void *, loff_
*
* Register a filesystem as desiring caching services if they're available.
*
- * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
@@ -253,7 +253,7 @@ int fscache_register_netfs(struct fscache_netfs *netfs)
* Indicate that a filesystem no longer desires caching services for the
* moment.
*
- * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
@@ -270,7 +270,7 @@ void fscache_unregister_netfs(struct fscache_netfs *netfs)
* Acquire a specific cache referral tag that can be used to select a specific
* cache in which to cache an index.
*
- * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
@@ -288,7 +288,7 @@ struct fscache_cache_tag *fscache_lookup_cache_tag(const char *name)
*
* Release a reference to a cache referral tag previously looked up.
*
- * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
@@ -315,7 +315,7 @@ void fscache_release_cache_tag(struct fscache_cache_tag *tag)
* that can be used to locate files. This is done by requesting a cookie for
* each index in the path to the file.
*
- * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
@@ -351,7 +351,7 @@ struct fscache_cookie *fscache_acquire_cookie(
* provided to update the auxiliary data in the cache before the object is
* disconnected.
*
- * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
@@ -394,7 +394,7 @@ int fscache_check_consistency(struct fscache_cookie *cookie,
* cookie. The auxiliary data on the cookie will be updated first if @aux_data
* is set.
*
- * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
@@ -410,7 +410,7 @@ void fscache_update_cookie(struct fscache_cookie *cookie, const void *aux_data)
*
* Permit data-storage cache objects to be pinned in the cache.
*
- * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
@@ -425,7 +425,7 @@ int fscache_pin_cookie(struct fscache_cookie *cookie)
*
* Permit data-storage cache objects to be unpinned from the cache.
*
- * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
@@ -441,7 +441,7 @@ void fscache_unpin_cookie(struct fscache_cookie *cookie)
* changed. This includes the data size. These attributes will be obtained
* through the get_attr() cookie definition op.
*
- * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
@@ -463,7 +463,7 @@ int fscache_attr_changed(struct fscache_cookie *cookie)
*
* This can be called with spinlocks held.
*
- * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
@@ -479,7 +479,7 @@ void fscache_invalidate(struct fscache_cookie *cookie)
*
* Wait for the invalidation of an object to complete.
*
- * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
@@ -498,7 +498,7 @@ void fscache_wait_on_invalidate(struct fscache_cookie *cookie)
* cookie so that a write to that object within the space can always be
* honoured.
*
- * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
@@ -533,7 +533,7 @@ int fscache_reserve_space(struct fscache_cookie *cookie, loff_t size)
* Else, if the page is unbacked, -ENODATA is returned and a block may have
* been allocated in the cache.
*
- * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
@@ -582,7 +582,7 @@ int fscache_read_or_alloc_page(struct fscache_cookie *cookie,
* regard to different pages, the return values are prioritised in that order.
* Any pages submitted for reading are removed from the pages list.
*
- * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
@@ -617,7 +617,7 @@ int fscache_read_or_alloc_pages(struct fscache_cookie *cookie,
* Else, a block will be allocated if one wasn't already, and 0 will be
* returned
*
- * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
@@ -667,7 +667,7 @@ void fscache_readpages_cancel(struct fscache_cookie *cookie,
* be cleared at the completion of the write to indicate the success or failure
* of the operation. Note that the completion may happen before the return.
*
- * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
@@ -693,7 +693,7 @@ int fscache_write_page(struct fscache_cookie *cookie,
* Note that this cannot cancel any outstanding I/O operations between this
* page and the cache.
*
- * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
@@ -711,7 +711,7 @@ void fscache_uncache_page(struct fscache_cookie *cookie,
*
* Ask the cache if a page is being written to the cache.
*
- * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
@@ -731,7 +731,7 @@ bool fscache_check_page_write(struct fscache_cookie *cookie,
* Ask the cache to wake us up when a page is no longer being written to the
* cache.
*
- * See Documentation/filesystems/caching/netfs-api.txt for a complete
+ * See Documentation/filesystems/caching/netfs-api.rst for a complete
* description.
*/
static inline
diff --git a/include/linux/kobject.h b/include/linux/kobject.h
index e2ca0a2..fc8d83e 100644
--- a/include/linux/kobject.h
+++ b/include/linux/kobject.h
@@ -7,7 +7,7 @@
* Copyright (c) 2006-2008 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (c) 2006-2008 Novell Inc.
*
- * Please read Documentation/kobject.txt before using the kobject
+ * Please read Documentation/core-api/kobject.rst before using the kobject
* interface, ESPECIALLY the parts about reference counts and object
* destructors.
*/
diff --git a/include/linux/kobject_ns.h b/include/linux/kobject_ns.h
index 069aa2e..2b5b642 100644
--- a/include/linux/kobject_ns.h
+++ b/include/linux/kobject_ns.h
@@ -8,7 +8,7 @@
*
* Split from kobject.h by David Howells (dhowells@redhat.com)
*
- * Please read Documentation/kobject.txt before using the kobject
+ * Please read Documentation/core-api/kobject.rst before using the kobject
* interface, ESPECIALLY the parts about reference counts and object
* destructors.
*/
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index 988ca0d..44d5422 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -77,7 +77,7 @@
* state. This is called immediately after commit_creds().
*
* Security hooks for mount using fs_context.
- * [See also Documentation/filesystems/mount_api.txt]
+ * [See also Documentation/filesystems/mount_api.rst]
*
* @fs_context_dup:
* Allocate and attach a security structure to sc->security. This pointer
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 3c71d1c..3468dbb 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1226,7 +1226,7 @@ void unpin_user_pages(struct page **pages, unsigned long npages);
* used to track the pincount (instead using of the GUP_PIN_COUNTING_BIAS
* scheme).
*
- * For more information, please see Documentation/vm/pin_user_pages.rst.
+ * For more information, please see Documentation/core-api/pin_user_pages.rst.
*
* @page: pointer to page to be queried.
* @Return: True, if it is likely that the page has been "dma-pinned".
@@ -2841,7 +2841,7 @@ struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
* releasing pages: get_user_pages*() pages must be released via put_page(),
* while pin_user_pages*() pages must be released via unpin_user_page().
*
- * Please see Documentation/vm/pin_user_pages.rst for more information.
+ * Please see Documentation/core-api/pin_user_pages.rst for more information.
*/
static inline int vm_fault_to_errno(vm_fault_t vm_fault, int foll_flags)
diff --git a/include/linux/platform_data/ad5761.h b/include/linux/platform_data/ad5761.h
index 02bef51..69e261e 100644
--- a/include/linux/platform_data/ad5761.h
+++ b/include/linux/platform_data/ad5761.h
@@ -3,7 +3,7 @@
* AD5721, AD5721R, AD5761, AD5761R, Voltage Output Digital to Analog Converter
*
* Copyright 2016 Qtechnology A/S
- * 2016 Ricardo Ribalda <ricardo.ribalda@gmail.com>
+ * 2016 Ricardo Ribalda <ribalda@kernel.org>
*/
#ifndef __LINUX_PLATFORM_DATA_AD5761_H__
#define __LINUX_PLATFORM_DATA_AD5761_H__
diff --git a/include/linux/printk.h b/include/linux/printk.h
index 07f2d08..15c8133 100644
--- a/include/linux/printk.h
+++ b/include/linux/printk.h
@@ -279,39 +279,116 @@ static inline void printk_safe_flush_on_panic(void)
extern int kptr_restrict;
+/**
+ * pr_fmt - used by the pr_*() macros to generate the printk format string
+ * @fmt: format string passed from a pr_*() macro
+ *
+ * This macro can be used to generate a unified format string for pr_*()
+ * macros. A common use is to prefix all pr_*() messages in a file with a common
+ * string. For example, defining this at the top of a source file:
+ *
+ * #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+ *
+ * would prefix all pr_info, pr_emerg... messages in the file with the module
+ * name.
+ */
#ifndef pr_fmt
#define pr_fmt(fmt) fmt
#endif
-/*
- * These can be used to print at the various log levels.
- * All of these will print unconditionally, although note that pr_debug()
- * and other debug macros are compiled out unless either DEBUG is defined
- * or CONFIG_DYNAMIC_DEBUG is set.
+/**
+ * pr_emerg - Print an emergency-level message
+ * @fmt: format string
+ * @...: arguments for the format string
+ *
+ * This macro expands to a printk with KERN_EMERG loglevel. It uses pr_fmt() to
+ * generate the format string.
*/
#define pr_emerg(fmt, ...) \
printk(KERN_EMERG pr_fmt(fmt), ##__VA_ARGS__)
+/**
+ * pr_alert - Print an alert-level message
+ * @fmt: format string
+ * @...: arguments for the format string
+ *
+ * This macro expands to a printk with KERN_ALERT loglevel. It uses pr_fmt() to
+ * generate the format string.
+ */
#define pr_alert(fmt, ...) \
printk(KERN_ALERT pr_fmt(fmt), ##__VA_ARGS__)
+/**
+ * pr_crit - Print a critical-level message
+ * @fmt: format string
+ * @...: arguments for the format string
+ *
+ * This macro expands to a printk with KERN_CRIT loglevel. It uses pr_fmt() to
+ * generate the format string.
+ */
#define pr_crit(fmt, ...) \
printk(KERN_CRIT pr_fmt(fmt), ##__VA_ARGS__)
+/**
+ * pr_err - Print an error-level message
+ * @fmt: format string
+ * @...: arguments for the format string
+ *
+ * This macro expands to a printk with KERN_ERR loglevel. It uses pr_fmt() to
+ * generate the format string.
+ */
#define pr_err(fmt, ...) \
printk(KERN_ERR pr_fmt(fmt), ##__VA_ARGS__)
+/**
+ * pr_warn - Print a warning-level message
+ * @fmt: format string
+ * @...: arguments for the format string
+ *
+ * This macro expands to a printk with KERN_WARNING loglevel. It uses pr_fmt()
+ * to generate the format string.
+ */
#define pr_warn(fmt, ...) \
printk(KERN_WARNING pr_fmt(fmt), ##__VA_ARGS__)
+/**
+ * pr_notice - Print a notice-level message
+ * @fmt: format string
+ * @...: arguments for the format string
+ *
+ * This macro expands to a printk with KERN_NOTICE loglevel. It uses pr_fmt() to
+ * generate the format string.
+ */
#define pr_notice(fmt, ...) \
printk(KERN_NOTICE pr_fmt(fmt), ##__VA_ARGS__)
+/**
+ * pr_info - Print an info-level message
+ * @fmt: format string
+ * @...: arguments for the format string
+ *
+ * This macro expands to a printk with KERN_INFO loglevel. It uses pr_fmt() to
+ * generate the format string.
+ */
#define pr_info(fmt, ...) \
printk(KERN_INFO pr_fmt(fmt), ##__VA_ARGS__)
-/*
- * Like KERN_CONT, pr_cont() should only be used when continuing
- * a line with no newline ('\n') enclosed. Otherwise it defaults
- * back to KERN_DEFAULT.
+
+/**
+ * pr_cont - Continues a previous log message in the same line.
+ * @fmt: format string
+ * @...: arguments for the format string
+ *
+ * This macro expands to a printk with KERN_CONT loglevel. It should only be
+ * used when continuing a log message with no newline ('\n') enclosed. Otherwise
+ * it defaults back to KERN_DEFAULT loglevel.
*/
#define pr_cont(fmt, ...) \
printk(KERN_CONT fmt, ##__VA_ARGS__)
-/* pr_devel() should produce zero code unless DEBUG is defined */
+/**
+ * pr_devel - Print a debug-level message conditionally
+ * @fmt: format string
+ * @...: arguments for the format string
+ *
+ * This macro expands to a printk with KERN_DEBUG loglevel if DEBUG is
+ * defined. Otherwise it does nothing.
+ *
+ * It uses pr_fmt() to generate the format string.
+ */
#ifdef DEBUG
#define pr_devel(fmt, ...) \
printk(KERN_DEBUG pr_fmt(fmt), ##__VA_ARGS__)
@@ -325,8 +402,19 @@ extern int kptr_restrict;
#if defined(CONFIG_DYNAMIC_DEBUG)
#include <linux/dynamic_debug.h>
-/* dynamic_pr_debug() uses pr_fmt() internally so we don't need it here */
-#define pr_debug(fmt, ...) \
+/**
+ * pr_debug - Print a debug-level message conditionally
+ * @fmt: format string
+ * @...: arguments for the format string
+ *
+ * This macro expands to dynamic_pr_debug() if CONFIG_DYNAMIC_DEBUG is
+ * set. Otherwise, if DEBUG is defined, it's equivalent to a printk with
+ * KERN_DEBUG loglevel. If DEBUG is not defined it does nothing.
+ *
+ * It uses pr_fmt() to generate the format string (dynamic_pr_debug() uses
+ * pr_fmt() internally).
+ */
+#define pr_debug(fmt, ...) \
dynamic_pr_debug(fmt, ##__VA_ARGS__)
#elif defined(DEBUG)
#define pr_debug(fmt, ...) \
diff --git a/include/linux/rbtree.h b/include/linux/rbtree.h
index 1fd61a9..d7db179 100644
--- a/include/linux/rbtree.h
+++ b/include/linux/rbtree.h
@@ -11,7 +11,7 @@
I know it's not the cleaner way, but in C (not in C++) to get
performances and genericity...
- See Documentation/rbtree.txt for documentation and samples.
+ See Documentation/core-api/rbtree.rst for documentation and samples.
*/
#ifndef _LINUX_RBTREE_H
diff --git a/include/linux/rbtree_augmented.h b/include/linux/rbtree_augmented.h
index 724b0d0..d1c53e9 100644
--- a/include/linux/rbtree_augmented.h
+++ b/include/linux/rbtree_augmented.h
@@ -21,7 +21,7 @@
* rb_insert_augmented() and rb_erase_augmented() are intended to be public.
* The rest are implementation details you are not expected to depend on.
*
- * See Documentation/rbtree.txt for documentation and samples.
+ * See Documentation/core-api/rbtree.rst for documentation and samples.
*/
struct rb_augment_callbacks {
diff --git a/include/linux/relay.h b/include/linux/relay.h
index c759f96..e13a333 100644
--- a/include/linux/relay.h
+++ b/include/linux/relay.h
@@ -141,7 +141,7 @@ struct rchan_callbacks
* cause relay_open() to create a single global buffer rather
* than the default set of per-cpu buffers.
*
- * See Documentation/filesystems/relay.txt for more info.
+ * See Documentation/filesystems/relay.rst for more info.
*/
struct dentry *(*create_buf_file)(const char *filename,
struct dentry *parent,
diff --git a/include/linux/spi/spi.h b/include/linux/spi/spi.h
index 38286de..aac57b5 100644
--- a/include/linux/spi/spi.h
+++ b/include/linux/spi/spi.h
@@ -394,6 +394,7 @@ static inline void spi_unregister_driver(struct spi_driver *sdrv)
* for example doing DMA mapping. Called from threaded
* context.
* @transfer_one: transfer a single spi_transfer.
+ *
* - return 0 if the transfer is finished,
* - return 1 if the transfer is still in progress. When
* the driver is finished with this transfer it must
diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
index 80bb865..86067db 100644
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -7,7 +7,7 @@
* Copyright (c) 2007 SUSE Linux Products GmbH
* Copyright (c) 2007 Tejun Heo <teheo@suse.de>
*
- * Please see Documentation/filesystems/sysfs.txt for more information.
+ * Please see Documentation/filesystems/sysfs.rst for more information.
*/
#ifndef _SYSFS_H_
diff --git a/include/linux/watchdog.h b/include/linux/watchdog.h
index 417d9f3..1464ce6 100644
--- a/include/linux/watchdog.h
+++ b/include/linux/watchdog.h
@@ -37,15 +37,15 @@ struct watchdog_governor;
*
* The watchdog_ops structure contains a list of low-level operations
* that control a watchdog device. It also contains the module that owns
- * these operations. The start and stop function are mandatory, all other
+ * these operations. The start function is mandatory, all other
* functions are optional.
*/
struct watchdog_ops {
struct module *owner;
/* mandatory operations */
int (*start)(struct watchdog_device *);
- int (*stop)(struct watchdog_device *);
/* optional operations */
+ int (*stop)(struct watchdog_device *);
int (*ping)(struct watchdog_device *);
unsigned int (*status)(struct watchdog_device *);
int (*set_timeout)(struct watchdog_device *, unsigned int);
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index 7fde763..1711e57 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -2,7 +2,7 @@
/*
* include/uapi/linux/ethtool_netlink.h - netlink interface for ethtool
*
- * See Documentation/networking/ethtool-netlink.txt in kernel source tree for
+ * See Documentation/networking/ethtool-netlink.rst in kernel source tree for
* doucumentation of the interface.
*/
diff --git a/include/uapi/linux/firewire-cdev.h b/include/uapi/linux/firewire-cdev.h
index 1acd2b1..7e5b5c1 100644
--- a/include/uapi/linux/firewire-cdev.h
+++ b/include/uapi/linux/firewire-cdev.h
@@ -308,7 +308,7 @@ struct fw_cdev_event_iso_interrupt_mc {
/**
* struct fw_cdev_event_iso_resource - Iso resources were allocated or freed
* @closure: See &fw_cdev_event_common;
- * set by %FW_CDEV_IOC_(DE)ALLOCATE_ISO_RESOURCE(_ONCE) ioctl
+ * set by``FW_CDEV_IOC_(DE)ALLOCATE_ISO_RESOURCE(_ONCE)`` ioctl
* @type: %FW_CDEV_EVENT_ISO_RESOURCE_ALLOCATED or
* %FW_CDEV_EVENT_ISO_RESOURCE_DEALLOCATED
* @handle: Reference by which an allocated resource can be deallocated
diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
index 428c7dd..fdd632c 100644
--- a/include/uapi/linux/kvm.h
+++ b/include/uapi/linux/kvm.h
@@ -116,7 +116,7 @@ struct kvm_irq_level {
* ACPI gsi notion of irq.
* For IA-64 (APIC model) IOAPIC0: irq 0-23; IOAPIC1: irq 24-47..
* For X86 (standard AT mode) PIC0/1: irq 0-15. IOAPIC0: 0-23..
- * For ARM: See Documentation/virt/kvm/api.txt
+ * For ARM: See Documentation/virt/kvm/api.rst
*/
union {
__u32 irq;
@@ -1107,7 +1107,7 @@ struct kvm_xen_hvm_config {
*
* KVM_IRQFD_FLAG_RESAMPLE indicates resamplefd is valid and specifies
* the irqfd to operate in resampling mode for level triggered interrupt
- * emulation. See Documentation/virt/kvm/api.txt.
+ * emulation. See Documentation/virt/kvm/api.rst.
*/
#define KVM_IRQFD_FLAG_RESAMPLE (1 << 1)
diff --git a/include/uapi/rdma/rdma_user_ioctl_cmds.h b/include/uapi/rdma/rdma_user_ioctl_cmds.h
index 7b1ec80..38ab7ac 100644
--- a/include/uapi/rdma/rdma_user_ioctl_cmds.h
+++ b/include/uapi/rdma/rdma_user_ioctl_cmds.h
@@ -36,7 +36,7 @@
#include <linux/types.h>
#include <linux/ioctl.h>
-/* Documentation/ioctl/ioctl-number.rst */
+/* Documentation/userspace-api/ioctl/ioctl-number.rst */
#define RDMA_IOCTL_MAGIC 0x1b
#define RDMA_VERBS_IOCTL \
_IOWR(RDMA_IOCTL_MAGIC, 1, struct ib_uverbs_ioctl_hdr)
diff --git a/kernel/futex.c b/kernel/futex.c
index b595328..b4b9f96 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -486,10 +486,13 @@ static u64 get_inode_sequence_number(struct inode *inode)
* The key words are stored in @key on success.
*
* For shared mappings (when @fshared), the key is:
+ *
* ( inode->i_sequence, page->index, offset_within_page )
+ *
* [ also see get_inode_sequence_number() ]
*
* For private mappings (or when !@fshared), the key is:
+ *
* ( current->mm, address, 0 )
*
* This allows (cross process, where applicable) identification of the futex
diff --git a/kernel/relay.c b/kernel/relay.c
index ade14fb..d0c9c28 100644
--- a/kernel/relay.c
+++ b/kernel/relay.c
@@ -1,7 +1,7 @@
/*
* Public API and common code for kernel->userspace relay file support.
*
- * See Documentation/filesystems/relay.txt for an overview.
+ * See Documentation/filesystems/relay.rst for an overview.
*
* Copyright (C) 2002-2005 - Tom Zanussi (zanussi@us.ibm.com), IBM Corp
* Copyright (C) 1999-2005 - Karim Yaghmour (karim@opersys.com)
diff --git a/lib/Kconfig b/lib/Kconfig
index 47667d3..df3f3da 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -433,7 +433,7 @@
See:
- Documentation/rbtree.txt
+ Documentation/core-api/rbtree.rst
for more information.
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 613ee4f..b3b05ad 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1515,7 +1515,7 @@
This code (~1k) is freed after boot. By then, the firewire stack
in charge of the OHCI-1394 controllers should be used instead.
- See Documentation/debugging-via-ohci1394.txt for more information.
+ See Documentation/core-api/debugging-via-ohci1394.rst for more information.
source "samples/Kconfig"
diff --git a/lib/bitmap.c b/lib/bitmap.c
index 89260aa..21a7640 100644
--- a/lib/bitmap.c
+++ b/lib/bitmap.c
@@ -182,21 +182,22 @@ EXPORT_SYMBOL(__bitmap_shift_left);
*
* In pictures, example for a big-endian 32-bit architecture:
*
- * @src:
- * 31 63
- * | |
- * 10000000 11000001 11110010 00010101 10000000 11000001 01110010 00010101
- * | | | |
- * 16 14 0 32
+ * The @src bitmap is::
*
- * if @cut is 3, and @first is 14, bits 14-16 in @src are cut and @dst is:
+ * 31 63
+ * | |
+ * 10000000 11000001 11110010 00010101 10000000 11000001 01110010 00010101
+ * | | | |
+ * 16 14 0 32
*
- * 31 63
- * | |
- * 10110000 00011000 00110010 00010101 00010000 00011000 00101110 01000010
- * | | |
- * 14 (bit 17 0 32
- * from @src)
+ * if @cut is 3, and @first is 14, bits 14-16 in @src are cut and @dst is::
+ *
+ * 31 63
+ * | |
+ * 10110000 00011000 00110010 00010101 00010000 00011000 00101110 01000010
+ * | | |
+ * 14 (bit 17 0 32
+ * from @src)
*
* Note that @dst and @src might overlap partially or entirely.
*
diff --git a/lib/kobject.c b/lib/kobject.c
index 83198cb..65fa7bf 100644
--- a/lib/kobject.c
+++ b/lib/kobject.c
@@ -6,7 +6,7 @@
* Copyright (c) 2006-2007 Greg Kroah-Hartman <greg@kroah.com>
* Copyright (c) 2006-2007 Novell Inc.
*
- * Please see the file Documentation/kobject.txt for critical information
+ * Please see the file Documentation/core-api/kobject.rst for critical information
* about using the kobject interface.
*/
@@ -670,7 +670,7 @@ static void kobject_cleanup(struct kobject *kobj)
kobject_name(kobj), kobj, __func__, kobj->parent);
if (t && !t->release)
- pr_debug("kobject: '%s' (%p): does not have a release() function, it is broken and must be fixed. See Documentation/kobject.txt.\n",
+ pr_debug("kobject: '%s' (%p): does not have a release() function, it is broken and must be fixed. See Documentation/core-api/kobject.rst.\n",
kobject_name(kobj), kobj);
/* send "remove" if the caller did not do it but sent "add" */
diff --git a/mm/gup.c b/mm/gup.c
index 87a6a59..a99acdc 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -2845,9 +2845,9 @@ EXPORT_SYMBOL_GPL(get_user_pages_fast);
* the arguments here are identical.
*
* FOLL_PIN means that the pages must be released via unpin_user_page(). Please
- * see Documentation/vm/pin_user_pages.rst for further details.
+ * see Documentation/core-api/pin_user_pages.rst for further details.
*
- * This is intended for Case 1 (DIO) in Documentation/vm/pin_user_pages.rst. It
+ * This is intended for Case 1 (DIO) in Documentation/core-api/pin_user_pages.rst. It
* is NOT intended for Case 2 (RDMA: long-term pins).
*/
int pin_user_pages_fast(unsigned long start, int nr_pages,
@@ -2885,9 +2885,9 @@ EXPORT_SYMBOL_GPL(pin_user_pages_fast);
* the arguments here are identical.
*
* FOLL_PIN means that the pages must be released via unpin_user_page(). Please
- * see Documentation/vm/pin_user_pages.rst for details.
+ * see Documentation/core-api/pin_user_pages.rst for details.
*
- * This is intended for Case 1 (DIO) in Documentation/vm/pin_user_pages.rst. It
+ * This is intended for Case 1 (DIO) in Documentation/core-api/pin_user_pages.rst. It
* is NOT intended for Case 2 (RDMA: long-term pins).
*/
long pin_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm,
@@ -2921,9 +2921,9 @@ EXPORT_SYMBOL(pin_user_pages_remote);
* FOLL_PIN is set.
*
* FOLL_PIN means that the pages must be released via unpin_user_page(). Please
- * see Documentation/vm/pin_user_pages.rst for details.
+ * see Documentation/core-api/pin_user_pages.rst for details.
*
- * This is intended for Case 1 (DIO) in Documentation/vm/pin_user_pages.rst. It
+ * This is intended for Case 1 (DIO) in Documentation/core-api/pin_user_pages.rst. It
* is NOT intended for Case 2 (RDMA: long-term pins).
*/
long pin_user_pages(unsigned long start, unsigned long nr_pages,
diff --git a/samples/Kconfig b/samples/Kconfig
index 9d236c3..205076c 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -171,7 +171,7 @@
config SAMPLE_ANDROID_BINDERFS
bool "Build Android binderfs example"
- depends on CONFIG_ANDROID_BINDERFS
+ depends on ANDROID_BINDERFS
help
Builds a sample program to illustrate the use of the Android binderfs
filesystem.
diff --git a/samples/binderfs/Makefile b/samples/binderfs/Makefile
index ea4c93d..a3ac547 100644
--- a/samples/binderfs/Makefile
+++ b/samples/binderfs/Makefile
@@ -1,2 +1,6 @@
# SPDX-License-Identifier: GPL-2.0-only
-obj-$(CONFIG_SAMPLE_ANDROID_BINDERFS) += binderfs_example.o
+ifndef CROSS_COMPILE
+ifdef CONFIG_SAMPLE_ANDROID_BINDERFS
+hostprogs := binderfs_example
+endif
+endif
diff --git a/scripts/kernel-doc b/scripts/kernel-doc
index f746ca8..f68d76d 100755
--- a/scripts/kernel-doc
+++ b/scripts/kernel-doc
@@ -213,7 +213,9 @@
my $type_constant2 = '\%([-_\w]+)';
my $type_func = '(\w+)\(\)';
my $type_param = '\@(\w*((\.\w+)|(->\w+))*(\.\.\.)?)';
+my $type_param_ref = '([\!]?)\@(\w*((\.\w+)|(->\w+))*(\.\.\.)?)';
my $type_fp_param = '\@(\w+)\(\)'; # Special RST handling for func ptr params
+my $type_fp_param2 = '\@(\w+->\S+)\(\)'; # Special RST handling for structs with func ptr params
my $type_env = '(\$\w+)';
my $type_enum = '\&(enum\s*([_\w]+))';
my $type_struct = '\&(struct\s*([_\w]+))';
@@ -236,6 +238,7 @@
[$type_typedef, "\\\\fI\$1\\\\fP"],
[$type_union, "\\\\fI\$1\\\\fP"],
[$type_param, "\\\\fI\$1\\\\fP"],
+ [$type_param_ref, "\\\\fI\$1\$2\\\\fP"],
[$type_member, "\\\\fI\$1\$2\$3\\\\fP"],
[$type_fallback, "\\\\fI\$1\\\\fP"]
);
@@ -249,6 +252,7 @@
[$type_member_func, "\\:c\\:type\\:`\$1\$2\$3\\\\(\\\\) <\$1>`"],
[$type_member, "\\:c\\:type\\:`\$1\$2\$3 <\$1>`"],
[$type_fp_param, "**\$1\\\\(\\\\)**"],
+ [$type_fp_param2, "**\$1\\\\(\\\\)**"],
[$type_func, "\$1()"],
[$type_enum, "\\:c\\:type\\:`\$1 <\$2>`"],
[$type_struct, "\\:c\\:type\\:`\$1 <\$2>`"],
@@ -256,7 +260,7 @@
[$type_union, "\\:c\\:type\\:`\$1 <\$2>`"],
# in rst this can refer to any type
[$type_fallback, "\\:c\\:type\\:`\$1`"],
- [$type_param, "**\$1**"]
+ [$type_param_ref, "**\$1\$2**"]
);
my $blankline_rst = "\n";
@@ -327,13 +331,14 @@
# Parser states
use constant {
- STATE_NORMAL => 0, # normal code
- STATE_NAME => 1, # looking for function name
- STATE_BODY_MAYBE => 2, # body - or maybe more description
- STATE_BODY => 3, # the body of the comment
- STATE_PROTO => 4, # scanning prototype
- STATE_DOCBLOCK => 5, # documentation block
- STATE_INLINE => 6, # gathering documentation outside main block
+ STATE_NORMAL => 0, # normal code
+ STATE_NAME => 1, # looking for function name
+ STATE_BODY_MAYBE => 2, # body - or maybe more description
+ STATE_BODY => 3, # the body of the comment
+ STATE_BODY_WITH_BLANK_LINE => 4, # the body, which has a blank line
+ STATE_PROTO => 5, # scanning prototype
+ STATE_DOCBLOCK => 6, # documentation block
+ STATE_INLINE => 7, # gathering doc outside main block
};
my $state;
my $in_doc_sect;
@@ -1953,6 +1958,12 @@
}
}
+ if ($state == STATE_BODY_WITH_BLANK_LINE && /^\s*\*\s?\S/) {
+ dump_section($file, $section, $contents);
+ $section = $section_default;
+ $contents = "";
+ }
+
if (/$doc_sect/i) { # case insensitive for supported section names
$newsection = $1;
$newcontents = $2;
@@ -2006,18 +2017,21 @@
$state = STATE_PROTO;
$brcount = 0;
} elsif (/$doc_content/) {
- # miguel-style comment kludge, look for blank lines after
- # @parameter line to signify start of description
if ($1 eq "") {
- if ($section =~ m/^@/ || $section eq $section_context) {
+ if ($section eq $section_context) {
dump_section($file, $section, $contents);
$section = $section_default;
$contents = "";
$new_start_line = $.;
+ $state = STATE_BODY;
} else {
+ if ($section ne $section_default) {
+ $state = STATE_BODY_WITH_BLANK_LINE;
+ } else {
+ $state = STATE_BODY;
+ }
$contents .= "\n";
}
- $state = STATE_BODY;
} elsif ($state == STATE_BODY_MAYBE) {
# Continued declaration purpose
chomp($declaration_purpose);
@@ -2169,7 +2183,8 @@
process_normal();
} elsif ($state == STATE_NAME) {
process_name($file, $_);
- } elsif ($state == STATE_BODY || $state == STATE_BODY_MAYBE) {
+ } elsif ($state == STATE_BODY || $state == STATE_BODY_MAYBE ||
+ $state == STATE_BODY_WITH_BLANK_LINE) {
process_body($file, $_);
} elsif ($state == STATE_INLINE) { # scanning for inline parameters
process_inline($file, $_);
diff --git a/scripts/sphinx-pre-install b/scripts/sphinx-pre-install
index fa3fb05..c680c3e 100755
--- a/scripts/sphinx-pre-install
+++ b/scripts/sphinx-pre-install
@@ -2,7 +2,7 @@
# SPDX-License-Identifier: GPL-2.0-or-later
use strict;
-# Copyright (c) 2017-2019 Mauro Carvalho Chehab <mchehab@kernel.org>
+# Copyright (c) 2017-2020 Mauro Carvalho Chehab <mchehab@kernel.org>
#
my $prefix = "./";
@@ -22,10 +22,16 @@
my $optional = 0;
my $need_symlink = 0;
my $need_sphinx = 0;
+my $need_venv = 0;
+my $need_virtualenv = 0;
my $rec_sphinx_upgrade = 0;
my $install = "";
my $virtenv_dir = "";
+my $python_cmd = "";
my $min_version;
+my $cur_version;
+my $rec_version = "1.7.9"; # PDF won't build here
+my $min_pdf_version = "2.4.4"; # Min version where pdf builds
#
# Command line arguments
@@ -142,12 +148,30 @@
}
}
+sub find_python_no_venv()
+{
+ my $prog = shift;
+
+ my $cur_dir = qx(pwd);
+ $cur_dir =~ s/\s+$//;
+
+ foreach my $dir (split(/:/, $ENV{PATH})) {
+ next if ($dir =~ m,($cur_dir)/sphinx,);
+ return "$dir/python3" if(-x "$dir/python3");
+ }
+ foreach my $dir (split(/:/, $ENV{PATH})) {
+ next if ($dir =~ m,($cur_dir)/sphinx,);
+ return "$dir/python" if(-x "$dir/python");
+ }
+ return "python";
+}
+
sub check_program($$)
{
my $prog = shift;
my $is_optional = shift;
- return if findprog($prog);
+ return $prog if findprog($prog);
add_package($prog, $is_optional);
}
@@ -168,9 +192,9 @@
my $prog = shift;
my $is_optional = shift;
- my $err = system("python3 -c 'import $prog' 2>/dev/null /dev/null");
- return if ($err == 0);
- my $err = system("python -c 'import $prog' 2>/dev/null /dev/null");
+ return if (!$python_cmd);
+
+ my $err = system("$python_cmd -c 'import $prog' 2>/dev/null /dev/null");
return if ($err == 0);
add_package($prog, $is_optional);
@@ -225,23 +249,33 @@
return $fname;
}
- if ($virtualenv) {
- my $prog = findprog("virtualenv-3");
- $prog = findprog("virtualenv-3.5") if (!$prog);
-
- check_program("virtualenv", 0) if (!$prog);
- $need_sphinx = 1;
- } else {
- add_package("python-sphinx", 0);
- }
-
return "";
}
+sub get_sphinx_version($)
+{
+ my $cmd = shift;
+ my $ver;
+
+ open IN, "$cmd --version 2>&1 |";
+ while (<IN>) {
+ if (m/^\s*sphinx-build\s+([\d\.]+)(\+\/[\da-f]+)?$/) {
+ $ver=$1;
+ last;
+ }
+ # Sphinx 1.2.x uses a different format
+ if (m/^\s*Sphinx.*\s+([\d\.]+)$/) {
+ $ver=$1;
+ last;
+ }
+ }
+ close IN;
+ return $ver;
+}
+
sub check_sphinx()
{
- my $rec_version;
- my $cur_version;
+ my $default_version;
open IN, $conf or die "Can't open $conf";
while (<IN>) {
@@ -257,45 +291,39 @@
open IN, $requirement_file or die "Can't open $requirement_file";
while (<IN>) {
if (m/^\s*Sphinx\s*==\s*([\d\.]+)$/) {
- $rec_version=$1;
+ $default_version=$1;
last;
}
}
close IN;
- die "Can't get recommended sphinx version from $requirement_file" if (!$min_version);
+ die "Can't get default sphinx version from $requirement_file" if (!$default_version);
- $virtenv_dir = $virtenv_prefix . $rec_version;
+ $virtenv_dir = $virtenv_prefix . $default_version;
my $sphinx = get_sphinx_fname();
- return if ($sphinx eq "");
-
- open IN, "$sphinx --version 2>&1 |" or die "$sphinx returned an error";
- while (<IN>) {
- if (m/^\s*sphinx-build\s+([\d\.]+)(\+\/[\da-f]+)?$/) {
- $cur_version=$1;
- last;
- }
- # Sphinx 1.2.x uses a different format
- if (m/^\s*Sphinx.*\s+([\d\.]+)$/) {
- $cur_version=$1;
- last;
- }
+ if ($sphinx eq "") {
+ $need_sphinx = 1;
+ return;
}
- close IN;
+
+ $cur_version = get_sphinx_version($sphinx);
+ die ("$sphinx returned an error") if (!$cur_version);
die "$sphinx didn't return its version" if (!$cur_version);
if ($cur_version lt $min_version) {
printf "ERROR: Sphinx version is %s. It should be >= %s (recommended >= %s)\n",
- $cur_version, $min_version, $rec_version;;
+ $cur_version, $min_version, $default_version;
$need_sphinx = 1;
return;
}
if ($cur_version lt $rec_version) {
- printf "Sphinx version %s\n", $cur_version;
- print "Warning: It is recommended at least Sphinx version $rec_version.\n";
+ $rec_sphinx_upgrade = 1;
+ return;
+ }
+ if ($cur_version lt $min_pdf_version) {
$rec_sphinx_upgrade = 1;
return;
}
@@ -336,6 +364,7 @@
my %map = (
"python-sphinx" => "python3-sphinx",
"sphinx_rtd_theme" => "python3-sphinx-rtd-theme",
+ "ensurepip" => "python3-venv",
"virtualenv" => "virtualenv",
"dot" => "graphviz",
"convert" => "imagemagick",
@@ -349,7 +378,8 @@
"fonts-dejavu", 2);
check_missing_file(["/usr/share/fonts/noto-cjk/NotoSansCJK-Regular.ttc",
- "/usr/share/fonts/opentype/noto/NotoSerifCJK-Regular.ttc"],
+ "/usr/share/fonts/opentype/noto/NotoSansCJK-Regular.ttc",
+ "/usr/share/fonts/opentype/noto/NotoSerifCJK-Regular.ttc"],
"fonts-noto-cjk", 2);
}
@@ -446,9 +476,11 @@
"convert" => "ImageMagick",
"Pod::Usage" => "perl-Pod-Usage",
"xelatex" => "texlive-xetex-bin",
- "rsvg-convert" => "rsvg-view",
);
+ # On Tumbleweed, this package is also named rsvg-convert
+ $map{"rsvg-convert"} = "rsvg-view" if (!($system_release =~ /Tumbleweed/));
+
my @suse_tex_pkgs = (
"texlive-babel-english",
"texlive-caption",
@@ -491,7 +523,7 @@
"convert" => "ImageMagick",
"Pod::Usage" => "perl-Pod-Usage",
"xelatex" => "texlive",
- "rsvg-convert" => "librsvg2-tools",
+ "rsvg-convert" => "librsvg2",
);
my @tex_pkgs = (
@@ -500,16 +532,29 @@
$map{"latexmk"} = "texlive-collection-basic";
+ my $packager_cmd;
+ my $noto_sans;
+ if ($system_release =~ /OpenMandriva/) {
+ $packager_cmd = "dnf install";
+ $noto_sans = "noto-sans-cjk-fonts";
+ @tex_pkgs = ( "texlive-collection-fontsextra" );
+ } else {
+ $packager_cmd = "urpmi";
+ $noto_sans = "google-noto-sans-cjk-ttc-fonts";
+ }
+
+
if ($pdf) {
- check_missing_file(["/usr/share/fonts/google-noto-cjk/NotoSansCJK-Regular.ttc"],
- "google-noto-sans-cjk-ttc-fonts", 2);
+ check_missing_file(["/usr/share/fonts/google-noto-cjk/NotoSansCJK-Regular.ttc",
+ "/usr/share/fonts/TTF/NotoSans-Regular.ttf"],
+ $noto_sans, 2);
}
check_rpm_missing(\@tex_pkgs, 2) if ($pdf);
check_missing(\%map);
return if (!$need && !$optional);
- printf("You should run:\n\n\tsudo urpmi $install\n");
+ printf("You should run:\n\n\tsudo $packager_cmd $install\n");
}
sub give_arch_linux_hints()
@@ -557,7 +602,8 @@
"media-fonts/dejavu", 2) if ($pdf);
if ($pdf) {
- check_missing_file(["/usr/share/fonts/noto-cjk/NotoSansCJKsc-Regular.otf"],
+ check_missing_file(["/usr/share/fonts/noto-cjk/NotoSansCJKsc-Regular.otf",
+ "/usr/share/fonts/noto-cjk/NotoSerifCJK-Regular.ttc"],
"media-fonts/noto-cjk", 2);
}
@@ -572,10 +618,10 @@
my $portage_imagemagick = "/etc/portage/package.use/imagemagick";
my $portage_cairo = "/etc/portage/package.use/graphviz";
- if (qx(cat $portage_imagemagick) ne "$imagemagick\n") {
+ if (qx(grep imagemagick $portage_imagemagick 2>/dev/null) eq "") {
printf("\tsudo su -c 'echo \"$imagemagick\" > $portage_imagemagick'\n")
}
- if (qx(cat $portage_cairo) ne "$cairo\n") {
+ if (qx(grep graphviz $portage_cairo 2>/dev/null) eq "") {
printf("\tsudo su -c 'echo \"$cairo\" > $portage_cairo'\n");
}
@@ -622,6 +668,10 @@
give_mageia_hints;
return;
}
+ if ($system_release =~ /OpenMandriva/) {
+ give_mageia_hints;
+ return;
+ }
if ($system_release =~ /Arch Linux/) {
give_arch_linux_hints;
return;
@@ -651,22 +701,58 @@
sub deactivate_help()
{
- printf "\tIf you want to exit the virtualenv, you can use:\n";
+ printf "\nIf you want to exit the virtualenv, you can use:\n";
printf "\tdeactivate\n";
}
sub check_needs()
{
- # Check for needed programs/tools
+ # Check if Sphinx is already accessible from current environment
check_sphinx();
if ($system_release) {
- print "Detected OS: $system_release.\n\n";
+ print "Detected OS: $system_release.\n";
} else {
- print "Unknown OS\n\n";
+ print "Unknown OS\n";
+ }
+ printf "Sphinx version: %s\n\n", $cur_version if ($cur_version);
+
+ # Check python command line, trying first python3
+ $python_cmd = findprog("python3");
+ $python_cmd = check_program("python", 0) if (!$python_cmd);
+
+ # Check the type of virtual env, depending on Python version
+ if ($python_cmd) {
+ if ($virtualenv) {
+ my $tmp = qx($python_cmd --version 2>&1);
+ if ($tmp =~ m/(\d+\.)(\d+\.)/) {
+ if ($1 >= 3 && $2 >= 3) {
+ $need_venv = 1; # python 3.3 or upper
+ } else {
+ $need_virtualenv = 1;
+ }
+ if ($1 < 3) {
+ # Complain if it finds python2 (or worse)
+ printf "Warning: python$1 support is deprecated. Use it with caution!\n";
+ }
+ } else {
+ die "Warning: couldn't identify $python_cmd version!";
+ }
+ } else {
+ add_package("python-sphinx", 0);
+ }
}
- print "To upgrade Sphinx, use:\n\n" if ($rec_sphinx_upgrade);
+ # Set virtualenv command line, if python < 3.3
+ my $virtualenv_cmd;
+ if ($need_virtualenv) {
+ $virtualenv_cmd = findprog("virtualenv-3");
+ $virtualenv_cmd = findprog("virtualenv-3.5") if (!$virtualenv_cmd);
+ if (!$virtualenv_cmd) {
+ check_program("virtualenv", 0);
+ $virtualenv_cmd = "virtualenv";
+ }
+ }
# Check for needed programs/tools
check_perl_module("Pod::Usage", 0);
@@ -681,46 +767,81 @@
check_program("rsvg-convert", 2) if ($pdf);
check_program("latexmk", 2) if ($pdf);
+ if ($need_sphinx || $rec_sphinx_upgrade) {
+ check_python_module("ensurepip", 0) if ($need_venv);
+ }
+
+ # Do distro-specific checks and output distro-install commands
check_distros();
+ if (!$python_cmd) {
+ if ($need == 1) {
+ die "Can't build as $need mandatory dependency is missing";
+ } elsif ($need) {
+ die "Can't build as $need mandatory dependencies are missing";
+ }
+ }
+
+ # Check if sphinx-build is called sphinx-build-3
if ($need_symlink) {
printf "\tsudo ln -sf %s /usr/bin/sphinx-build\n\n",
which("sphinx-build-3");
}
+
+ # NOTE: if the system has a too old Sphinx version installed,
+ # it will recommend installing a newer version using virtualenv
+
if ($need_sphinx || $rec_sphinx_upgrade) {
my $min_activate = "$ENV{'PWD'}/${virtenv_prefix}${min_version}/bin/activate";
my @activates = glob "$ENV{'PWD'}/${virtenv_prefix}*/bin/activate";
+ if ($cur_version lt $rec_version) {
+ print "Warning: It is recommended at least Sphinx version $rec_version.\n";
+ print " If you want pdf, you need at least $min_pdf_version.\n";
+ }
+ if ($cur_version lt $min_pdf_version) {
+ print "Note: It is recommended at least Sphinx version $min_pdf_version if you need PDF support.\n";
+ }
@activates = sort {$b cmp $a} @activates;
+ my ($activate, $ver);
+ foreach my $f (@activates) {
+ next if ($f lt $min_activate);
- if ($need_sphinx && scalar @activates > 0 && $activates[0] ge $min_activate) {
- printf "\nNeed to activate a compatible Sphinx version on virtualenv with:\n";
- printf "\t. $activates[0]\n";
- deactivate_help();
- exit (1);
+ my $sphinx_cmd = $f;
+ $sphinx_cmd =~ s/activate/sphinx-build/;
+ next if (! -f $sphinx_cmd);
+
+ $ver = get_sphinx_version($sphinx_cmd);
+ if ($need_sphinx && ($ver ge $min_version)) {
+ $activate = $f;
+ last;
+ } elsif ($ver gt $cur_version) {
+ $activate = $f;
+ last;
+ }
+ }
+ if ($activate ne "") {
+ if ($need_sphinx) {
+ printf "\nNeed to activate Sphinx (version $ver) on virtualenv with:\n";
+ printf "\t. $activate\n";
+ deactivate_help();
+ exit (1);
+ } else {
+ printf "\nYou may also use a newer Sphinx (version $ver) with:\n";
+ printf "\tdeactivate && . $activate\n";
+ }
} else {
my $rec_activate = "$virtenv_dir/bin/activate";
- my $virtualenv = findprog("virtualenv-3");
- my $rec_python3 = "";
- $virtualenv = findprog("virtualenv-3.5") if (!$virtualenv);
- $virtualenv = findprog("virtualenv") if (!$virtualenv);
- $virtualenv = "virtualenv" if (!$virtualenv);
- my $rel = "";
- if (index($system_release, "Ubuntu") != -1) {
- $rel = $1 if ($system_release =~ /Ubuntu\s+(\d+)[.]/);
- if ($rel && $rel >= 16) {
- $rec_python3 = " -p python3";
- }
- }
- if (index($system_release, "Debian") != -1) {
- $rel = $1 if ($system_release =~ /Debian\s+(\d+)/);
- if ($rel && $rel >= 7) {
- $rec_python3 = " -p python3";
- }
- }
+ print "To upgrade Sphinx, use:\n\n" if ($rec_sphinx_upgrade);
- printf "\t$virtualenv$rec_python3 $virtenv_dir\n";
+ $python_cmd = find_python_no_venv();
+
+ if ($need_venv) {
+ printf "\t$python_cmd -m venv $virtenv_dir\n";
+ } else {
+ printf "\t$virtualenv_cmd $virtenv_dir\n";
+ }
printf "\t. $rec_activate\n";
printf "\tpip install -r $requirement_file\n";
deactivate_help();
@@ -780,6 +901,24 @@
$system_release = catcheck("/etc/redhat-release") if !$system_release;
$system_release = catcheck("/etc/lsb-release") if !$system_release;
$system_release = catcheck("/etc/gentoo-release") if !$system_release;
+
+# This seems more common than LSB these days
+if (!$system_release) {
+ my %os_var;
+ if (open IN, "cat /etc/os-release|") {
+ while (<IN>) {
+ if (m/^([\w\d\_]+)=\"?([^\"]*)\"?\n/) {
+ $os_var{$1}=$2;
+ }
+ }
+ $system_release = $os_var{"NAME"};
+ if (defined($os_var{"VERSION_ID"})) {
+ $system_release .= " " . $os_var{"VERSION_ID"} if (defined($os_var{"VERSION_ID"}));
+ } else {
+ $system_release .= " " . $os_var{"VERSION"};
+ }
+ }
+}
$system_release = catcheck("/etc/issue") if !$system_release;
$system_release =~ s/\s+$//;
diff --git a/tools/include/linux/rbtree.h b/tools/include/linux/rbtree.h
index e03b1ea..30dd21f 100644
--- a/tools/include/linux/rbtree.h
+++ b/tools/include/linux/rbtree.h
@@ -11,7 +11,7 @@
I know it's not the cleaner way, but in C (not in C++) to get
performances and genericity...
- See Documentation/rbtree.txt for documentation and samples.
+ See Documentation/core-api/rbtree.rst for documentation and samples.
*/
#ifndef __TOOLS_LINUX_PERF_RBTREE_H
diff --git a/tools/include/linux/rbtree_augmented.h b/tools/include/linux/rbtree_augmented.h
index 381aa94..570bb97 100644
--- a/tools/include/linux/rbtree_augmented.h
+++ b/tools/include/linux/rbtree_augmented.h
@@ -23,7 +23,7 @@
* rb_insert_augmented() and rb_erase_augmented() are intended to be public.
* The rest are implementation details you are not expected to depend on.
*
- * See Documentation/rbtree.txt for documentation and samples.
+ * See Documentation/core-api/rbtree.rst for documentation and samples.
*/
struct rb_augment_callbacks {
diff --git a/tools/include/uapi/linux/kvm.h b/tools/include/uapi/linux/kvm.h
index 428c7dd..fdd632c 100644
--- a/tools/include/uapi/linux/kvm.h
+++ b/tools/include/uapi/linux/kvm.h
@@ -116,7 +116,7 @@ struct kvm_irq_level {
* ACPI gsi notion of irq.
* For IA-64 (APIC model) IOAPIC0: irq 0-23; IOAPIC1: irq 24-47..
* For X86 (standard AT mode) PIC0/1: irq 0-15. IOAPIC0: 0-23..
- * For ARM: See Documentation/virt/kvm/api.txt
+ * For ARM: See Documentation/virt/kvm/api.rst
*/
union {
__u32 irq;
@@ -1107,7 +1107,7 @@ struct kvm_xen_hvm_config {
*
* KVM_IRQFD_FLAG_RESAMPLE indicates resamplefd is valid and specifies
* the irqfd to operate in resampling mode for level triggered interrupt
- * emulation. See Documentation/virt/kvm/api.txt.
+ * emulation. See Documentation/virt/kvm/api.rst.
*/
#define KVM_IRQFD_FLAG_RESAMPLE (1 << 1)
diff --git a/virt/kvm/arm/vgic/vgic-mmio-v3.c b/virt/kvm/arm/vgic/vgic-mmio-v3.c
index 89a14ec..d2339a2 100644
--- a/virt/kvm/arm/vgic/vgic-mmio-v3.c
+++ b/virt/kvm/arm/vgic/vgic-mmio-v3.c
@@ -302,7 +302,7 @@ static unsigned long vgic_v3_uaccess_read_pending(struct kvm_vcpu *vcpu,
* pending state of interrupt is latched in pending_latch variable.
* Userspace will save and restore pending state and line_level
* separately.
- * Refer to Documentation/virt/kvm/devices/arm-vgic-v3.txt
+ * Refer to Documentation/virt/kvm/devices/arm-vgic-v3.rst
* for handling of ISPENDR and ICPENDR.
*/
for (i = 0; i < len * 8; i++) {
diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h
index 769e480..64fcd75 100644
--- a/virt/kvm/arm/vgic/vgic.h
+++ b/virt/kvm/arm/vgic/vgic.h
@@ -42,7 +42,7 @@
VGIC_AFFINITY_LEVEL(val, 3))
/*
- * As per Documentation/virt/kvm/devices/arm-vgic-v3.txt,
+ * As per Documentation/virt/kvm/devices/arm-vgic-v3.rst,
* below macros are defined for CPUREG encoding.
*/
#define KVM_REG_ARM_VGIC_SYSREG_OP0_MASK 0x000000000000c000
@@ -63,7 +63,7 @@
KVM_REG_ARM_VGIC_SYSREG_OP2_MASK)
/*
- * As per Documentation/virt/kvm/devices/arm-vgic-its.txt,
+ * As per Documentation/virt/kvm/devices/arm-vgic-its.rst,
* below macros are defined for ITS table entry encoding.
*/
#define KVM_ITS_CTE_VALID_SHIFT 63
