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review.shift-gmbh.com / SHIFTPHONES / kernel / common / 8d6c90c9d68b985fa809626d12f8c9aff3c9dcb1
commit8d6c90c9d68b985fa809626d12f8c9aff3c9dcb1[log] [tgz]
authorEric Biggers <ebiggers@google.com>Tue May 19 16:11:59 2020 -0700
committerEric Biggers <ebiggers@google.com>Thu May 21 10:09:43 2020 -0700
tree356a6a02def72e1550a69c3f779319f575356fdf
parent06a813d6df5848148953d110326c099ebe2205fc [diff]
ANDROID: fscrypt: handle direct I/O with IV_INO_LBLK_32

With the existing fscrypt IV generation methods, each file's data blocks
have contiguous DUNs.  Therefore the direct I/O code "just worked"
because it only submits logically contiguous bios.  But with
IV_INO_LBLK_32, the direct I/O code breaks because the DUN can wrap from
0xffffffff to 0.  We can't submit bios across such boundaries.

This is especially difficult to handle when block_size != PAGE_SIZE,
since in that case the DUN can wrap in the middle of a page.  Punt on
this case for now and just handle block_size == PAGE_SIZE.

Add and use a new function fscrypt_dio_supported() to check whether a
direct I/O request is unsupported due to encryption constraints.

Then, update fs/direct-io.c (used by f2fs, and by ext4 in kernel v5.4
and earlier) and fs/iomap/direct-io.c (used by ext4 in kernel v5.5 and
later) to avoid submitting I/O across a DUN discontinuity.

(This is needed in ACK now because ACK already supports direct I/O with
inline crypto.  I'll be sending this upstream along with the encrypted
direct I/O support itself once its prerequisites are closer to landing.)

Test: For now, just manually tested direct I/O on ext4 and f2fs in the
      DUN discontinuity case.
Bug: 144046242
Change-Id: I0c0b0b20a73ade35c3660cc6f9c09d49d3853ba5
Signed-off-by: Eric Biggers <ebiggers@google.com>
7 files changed
tree: 356a6a02def72e1550a69c3f779319f575356fdf
  1. arch/
  2. block/
  3. certs/
  4. crypto/
  5. Documentation/
  6. drivers/
  7. fs/
  8. include/
  9. init/
  10. ipc/
  11. kernel/
  12. lib/
  13. LICENSES/
  14. mm/
  15. net/
  16. samples/
  17. scripts/
  18. security/
  19. sound/
  20. tools/
  21. usr/
  22. virt/
  23. .clang-format
  24. .cocciconfig
  25. .get_maintainer.ignore
  26. .gitattributes
  27. .gitignore
  28. .mailmap
  29. build.config.aarch64
  30. build.config.allmodconfig
  31. build.config.allmodconfig.aarch64
  32. build.config.allmodconfig.arm
  33. build.config.allmodconfig.x86_64
  34. build.config.arm
  35. build.config.common
  36. build.config.db845c
  37. build.config.gki
  38. build.config.gki.aarch64
  39. build.config.gki.x86_64
  40. build.config.gki_kasan
  41. build.config.gki_kasan.aarch64
  42. build.config.gki_kasan.x86_64
  43. build.config.x86_64
  44. COPYING
  45. CREDITS
  46. Kbuild
  47. Kconfig
  48. MAINTAINERS
  49. Makefile
  50. README
  51. README.md
README.md

How do I submit patches to Android Common Kernels

  1. BEST: Make all of your changes to upstream Linux. If appropriate, backport to the stable releases. These patches will be merged automatically in the corresponding common kernels. If the patch is already in upstream Linux, post a backport of the patch that conforms to the patch requirements below.

    • Do not send patches upstream that contain only symbol exports. To be considered for upstream Linux, additions of EXPORT_SYMBOL_GPL() require an in-tree modular driver that uses the symbol -- so include the new driver or changes to an existing driver in the same patchset as the export.
    • When sending patches upstream, the commit message must contain a clear case for why the patch is needed and beneficial to the community. Enabling out-of-tree drivers or functionality is not not a persuasive case.

  2. LESS GOOD: Develop your patches out-of-tree (from an upstream Linux point-of-view). Unless these are fixing an Android-specific bug, these are very unlikely to be accepted unless they have been coordinated with kernel-team@android.com. If you want to proceed, post a patch that conforms to the patch requirements below.

Common Kernel patch requirements

  • All patches must conform to the Linux kernel coding standards and pass script/checkpatch.pl
  • Patches shall not break gki_defconfig or allmodconfig builds for arm, arm64, x86, x86_64 architectures (see https://source.android.com/setup/build/building-kernels)
  • If the patch is not merged from an upstream branch, the subject must be tagged with the type of patch: UPSTREAM:, BACKPORT:, FROMGIT:, FROMLIST:, or ANDROID:.
  • All patches must have a Change-Id: tag (see https://gerrit-review.googlesource.com/Documentation/user-changeid.html)
  • If an Android bug has been assigned, there must be a Bug: tag.
  • All patches must have a Signed-off-by: tag by the author and the submitter

Additional requirements are listed below based on patch type

Requirements for backports from mainline Linux: UPSTREAM:, BACKPORT:

  • If the patch is a cherry-pick from Linux mainline with no changes at all
    • tag the patch subject with UPSTREAM:.
    • add upstream commit information with a (cherry picked from commit ...) line
    • Example:
      • if the upstream commit message is
        important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>
  • then Joe Smith would upload the patch for the common kernel as
        UPSTREAM: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

        Bug: 135791357
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        (cherry picked from commit c31e73121f4c1ec41143423ac6ce3ce6dafdcec1)
        Signed-off-by: Joe Smith <joe.smith@foo.org>
  • If the patch requires any changes from the upstream version, tag the patch with BACKPORT: instead of UPSTREAM:.
    • use the same tags as UPSTREAM:
    • add comments about the changes under the (cherry picked from commit ...) line
    • Example:
        BACKPORT: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

        Bug: 135791357
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        (cherry picked from commit c31e73121f4c1ec41143423ac6ce3ce6dafdcec1)
        [joe: Resolved minor conflict in drivers/foo/bar.c ]
        Signed-off-by: Joe Smith <joe.smith@foo.org>

Requirements for other backports: FROMGIT:, FROMLIST:,

  • If the patch has been merged into an upstream maintainer tree, but has not yet been merged into Linux mainline
    • tag the patch subject with FROMGIT:
    • add info on where the patch came from as (cherry picked from commit <sha1> <repo> <branch>). This must be a stable maintainer branch (not rebased, so don't use linux-next for example).
    • if changes were required, use BACKPORT: FROMGIT:
    • Example:
      • if the commit message in the maintainer tree is
        important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>
  • then Joe Smith would upload the patch for the common kernel as
        FROMGIT: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

        Bug: 135791357
        (cherry picked from commit 878a2fd9de10b03d11d2f622250285c7e63deace
         https://git.kernel.org/pub/scm/linux/kernel/git/foo/bar.git test-branch)
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        Signed-off-by: Joe Smith <joe.smith@foo.org>
  • If the patch has been submitted to LKML, but not accepted into any maintainer tree
    • tag the patch subject with FROMLIST:
    • add a Link: tag with a link to the submittal on lore.kernel.org
    • add a Bug: tag with the Android bug (required for patches not accepted into a maintainer tree)
    • if changes were required, use BACKPORT: FROMLIST:
    • Example:
        FROMLIST: important patch from upstream

        This is the detailed description of the important patch

        Signed-off-by: Fred Jones <fred.jones@foo.org>

        Bug: 135791357
        Link: https://lore.kernel.org/lkml/20190619171517.GA17557@someone.com/
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        Signed-off-by: Joe Smith <joe.smith@foo.org>

Requirements for Android-specific patches: ANDROID:

  • If the patch is fixing a bug to Android-specific code
    • tag the patch subject with ANDROID:
    • add a Fixes: tag that cites the patch with the bug
    • Example:
        ANDROID: fix android-specific bug in foobar.c

        This is the detailed description of the important fix

        Fixes: 1234abcd2468 ("foobar: add cool feature")
        Change-Id: I4caaaa566ea080fa148c5e768bb1a0b6f7201c01
        Signed-off-by: Joe Smith <joe.smith@foo.org>
  • If the patch is a new feature
    • tag the patch subject with ANDROID:
    • add a Bug: tag with the Android bug (required for android-specific features)