[PATCH v9 0/5] io_uring: add xattr support

[Stefan Roesch <shr@fb.com>]

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_copy and do_setxattr function from setxattr
  Split off the setup part of the setxattr function in the setxattr_copy
  function. Split off the processing part in do_setxattr.

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.


V9: - keep kvalue in struct xattr_ctx
V8: - introduce xattr_name struct as advised by Linus
    - remove kname_sz field in xattr_ctx
V7: - split off setxattr in two functions as recommeneded by
      Christian.
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.
    - addressed Pavel's reordering comment
    - addressed Pavel's putname comment
    - addressed Pavel's kvfree comment
    - 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_copy and do_setxattr 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                 |  28 +++
 fs/io_uring.c                 | 314 ++++++++++++++++++++++++++++++++++
 fs/namei.c                    |  10 +-
 fs/xattr.c                    | 114 ++++++++----
 include/linux/namei.h         |   2 +
 include/uapi/linux/io_uring.h |   8 +-
 6 files changed, 438 insertions(+), 38 deletions(-)


base-commit: b4518682080d3a1cdd6ea45a54ff6772b8b2797a
-- 
2.30.2