UPSTREAM: procfs/dmabuf: add inode number to /proc/*/fdinfo
And 'ino' field to /proc/<pid>/fdinfo/<FD> and
/proc/<pid>/task/<tid>/fdinfo/<FD>.
The inode numbers can be used to uniquely identify DMA buffers in user
space and avoids a dependency on /proc/<pid>/fd/* when accounting
per-process DMA buffer sizes.
Link: https://lkml.kernel.org/r/20210308170651.919148-2-kaleshsingh@google.com
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Christian König <christian.koenig@amd.com>
Cc: Jann Horn <jannh@google.com>
Cc: Jeff Vander Stoep <jeffv@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Hridya Valsaraju <hridya@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Alexey Gladkov <gladkov.alexey@gmail.com>
Cc: Szabolcs Nagy <szabolcs.nagy@arm.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Bernd Edlinger <bernd.edlinger@hotmail.de>
Cc: Andrei Vagin <avagin@gmail.com>
Cc: Helge Deller <deller@gmx.de>
Cc: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 3845f256a8b527127bfbd4ced21e93d9e89aa6d7)
Bug: 159126739
Bug: 167141117
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Change-Id: Id07beac3edcc95c0b42805e24e5486965acbb46e
diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
index 05891a0..1b506a5 100644
--- a/Documentation/filesystems/proc.rst
+++ b/Documentation/filesystems/proc.rst
@@ -1906,18 +1906,20 @@
3.8 /proc/<pid>/fdinfo/<fd> - Information about opened file
---------------------------------------------------------------
This file provides information associated with an opened file. The regular
-files have at least three fields -- 'pos', 'flags' and 'mnt_id'. The 'pos'
-represents the current offset of the opened file in decimal form [see lseek(2)
-for details], 'flags' denotes the octal O_xxx mask the file has been
-created with [see open(2) for details] and 'mnt_id' represents mount ID of
-the file system containing the opened file [see 3.5 /proc/<pid>/mountinfo
-for details].
+files have at least four fields -- 'pos', 'flags', 'mnt_id' and 'ino'.
+The 'pos' represents the current offset of the opened file in decimal
+form [see lseek(2) for details], 'flags' denotes the octal O_xxx mask the
+file has been created with [see open(2) for details] and 'mnt_id' represents
+mount ID of the file system containing the opened file [see 3.5
+/proc/<pid>/mountinfo for details]. 'ino' represents the inode number of
+the file.
A typical output is::
pos: 0
flags: 0100002
mnt_id: 19
+ ino: 63107
All locks associated with a file descriptor are shown in its fdinfo too::
@@ -1934,6 +1936,7 @@
pos: 0
flags: 04002
mnt_id: 9
+ ino: 63107
eventfd-count: 5a
where 'eventfd-count' is hex value of a counter.
@@ -1946,6 +1949,7 @@
pos: 0
flags: 04002
mnt_id: 9
+ ino: 63107
sigmask: 0000000000000200
where 'sigmask' is hex value of the signal mask associated
@@ -1959,6 +1963,7 @@
pos: 0
flags: 02
mnt_id: 9
+ ino: 63107
tfd: 5 events: 1d data: ffffffffffffffff pos:0 ino:61af sdev:7
where 'tfd' is a target file descriptor number in decimal form,
@@ -1975,6 +1980,8 @@
pos: 0
flags: 02000000
+ mnt_id: 9
+ ino: 63107
inotify wd:3 ino:9e7e sdev:800013 mask:800afce ignored_mask:0 fhandle-bytes:8 fhandle-type:1 f_handle:7e9e0000640d1b6d
where 'wd' is a watch descriptor in decimal form, i.e. a target file
@@ -1997,6 +2004,7 @@
pos: 0
flags: 02
mnt_id: 9
+ ino: 63107
fanotify flags:10 event-flags:0
fanotify mnt_id:12 mflags:40 mask:38 ignored_mask:40000003
fanotify ino:4f969 sdev:800013 mflags:0 mask:3b ignored_mask:40000000 fhandle-bytes:8 fhandle-type:1 f_handle:69f90400c275b5b4
@@ -2021,6 +2029,7 @@
pos: 0
flags: 02
mnt_id: 9
+ ino: 63107
clockid: 0
ticks: 0
settime flags: 01
@@ -2035,6 +2044,22 @@
with TIMER_ABSTIME option which will be shown in 'settime flags', but 'it_value'
still exhibits timer's remaining time.
+DMA Buffer files
+~~~~~~~~~~~~~~~~
+
+::
+
+ pos: 0
+ flags: 04002
+ mnt_id: 9
+ ino: 63107
+ size: 32768
+ count: 2
+ exp_name: system-heap
+
+where 'size' is the size of the DMA buffer in bytes. 'count' is the file count of
+the DMA buffer file. 'exp_name' is the name of the DMA buffer exporter.
+
3.9 /proc/<pid>/map_files - Information about memory mapped files
---------------------------------------------------------------------
This directory contains symbolic links which represent memory mapped files
diff --git a/fs/proc/fd.c b/fs/proc/fd.c
index b0357e5..6157913 100644
--- a/fs/proc/fd.c
+++ b/fs/proc/fd.c
@@ -54,9 +54,10 @@ static int seq_show(struct seq_file *m, void *v)
if (ret)
return ret;
- seq_printf(m, "pos:\t%lli\nflags:\t0%o\nmnt_id:\t%i\n",
+ seq_printf(m, "pos:\t%lli\nflags:\t0%o\nmnt_id:\t%i\nino:\t%lu\n",
(long long)file->f_pos, f_flags,
- real_mount(file->f_path.mnt)->mnt_id);
+ real_mount(file->f_path.mnt)->mnt_id,
+ file_inode(file)->i_ino);
show_fd_locks(m, file, files);
if (seq_has_overflowed(m))