Re: [PATCH v6 0/5] io_uring: add xattr support

[Jens Axboe <axboe@kernel.dk>]

On 12/23/21 4:04 AM, Christian Brauner wrote:
> On Wed, Dec 22, 2021 at 01:01:22PM -0800, Stefan Roesch wrote:
>> This adds the xattr support to io_uring. The intent is to have a more
>> complete support for file operations in io_uring.
>>
>> This change adds support for the following functions to io_uring:
>> - fgetxattr
>> - fsetxattr
>> - getxattr
>> - setxattr
>>
>> Patch 1: fs: split off do_user_path_at_empty from user_path_at_empty()
>>   This splits off a new function do_user_path_at_empty from
>>   user_path_at_empty that is based on filename and not on a
>>   user-specified string.
>>
>> Patch 2: fs: split off setxattr_setup function from setxattr
>>   Split off the setup part of the setxattr function.
>>
>> Patch 3: fs: split off do_getxattr from getxattr
>>   Split of the do_getxattr part from getxattr. This will
>>   allow it to be invoked it from io_uring.
>>
>> Patch 4: io_uring: add fsetxattr and setxattr support
>>   This adds new functions to support the fsetxattr and setxattr
>>   functions.
>>
>> Patch 5: io_uring: add fgetxattr and getxattr support
>>   This adds new functions to support the fgetxattr and getxattr
>>   functions.
>>
>>
>> There are two additional patches:
>>   liburing: Add support for xattr api's.
>>             This also includes the tests for the new code.
>>   xfstests: Add support for io_uring xattr support.
>>
>>
>> V6: - reverted addition of kname array to xattr_ctx structure
>>       Adding the kname array increases the io_kiocb beyond 64 bytes
>>       (increases it to 224 bytes). We try hard to limit it to 64 bytes.
>>       Keeping the original interface also is a bit more efficient.
>>     - rebased on for-5.17/io_uring-getdents64
>> V5: - add kname array to xattr_ctx structure
>> V4: - rebased patch series
>> V3: - remove req->file checks in prep functions
>>     - change size parameter in do_xattr
>> V2: - split off function do_user_path_empty instead of changing
>>       the function signature of user_path_at
>>     - Fix datatype size problem in do_getxattr
>>
>>
>>
>> Stefan Roesch (5):
>>   fs: split off do_user_path_at_empty from user_path_at_empty()
>>   fs: split off setxattr_setup function from setxattr
>>   fs: split off do_getxattr from getxattr
>>   io_uring: add fsetxattr and setxattr support
>>   io_uring: add fgetxattr and getxattr support
>>
>>  fs/internal.h                 |  23 +++
>>  fs/io_uring.c                 | 318 ++++++++++++++++++++++++++++++++++
>>  fs/namei.c                    |  10 +-
>>  fs/xattr.c                    | 107 ++++++++----
>>  include/linux/namei.h         |   2 +
>>  include/uapi/linux/io_uring.h |   8 +-
>>  6 files changed, 428 insertions(+), 40 deletions(-)
>>
>>
>> base-commit: b4518682080d3a1cdd6ea45a54ff6772b8b2797a
> 
> Jens, please keep me in the loop once this series lands.

You bet, and thanks for the reviews!

> I maintain a large vfs testsuite for idmapped mounts (It's actually a
> generic testsuite which also tests idmapped mounts.) and it currently
> already has tests for io_uring:
> 
> https://git.kernel.org/pub/scm/fs/xfs/xfstests-dev.git/tree/src/idmapped-mounts/idmapped-mounts.c#n6942
> 
> Once this lands we need to expand it to test xattr support for io_uring
> as well (It should probably also include mkdir/link/mknod that we added
> last cycle.).

There are a few basic tests here:

https://git.kernel.dk/cgit/liburing/log/?h=xattr

as well, but more of a sanity kind of checking, would be great if tests
were added to the VFS suite as well.

With the last few kinks ironed out, I hope to queue the next version
posted for 5.17.

-- 
Jens Axboe