[RFC PATCH 0/2] [gs]etfsxattrat() followup patches

[Amir Goldstein <amir73il@gmail.com>]

Andrey,

These patches are based on your [gs]etfsxattrat() patcehs [1].

I think that the first patch should be enough to allow Pali to later
extend the API for new flags. Please add it to your patch series.
I have only sanotify tested the ioctls, have not tested the syscalls.

The second patch is an RFC of how the API could be extended to query
filesystems for supported flags and allow userspace to set a subset
of flags and fields.

It plumbs in the fsx_xflags_mask semantics without implementing any
filesystem that reports non-zero mask. Obviously, I did not test this
pluming with no filesystem support, so this is mainly posted as a
reference design or for Pali if he has time to add his filesystem
support patch [2] and test it.

If the semantics of zero mask meaning no mask are not acceptable,
that I had also considered changing FSXATTR_SIZE_VER0 to 20 for the
first release, so initially users will need to pass usize that does
not include fsx_pad, until we decide on the way to extend the API.

Thanks,
Amir.

[1] https://lore.kernel.org/linux-fsdevel/20250321-xattrat-syscall-v4-0-3e82e6fb3264@kernel.org/
[2]https://lore.kernel.org/linux-fsdevel/20250216164029.20673-4-pali@kernel.org/

Amir Goldstein (2):
  fs: prepare for extending [gs]etfsxattrat()
  fs: add support for custom fsx_xflags_mask

 fs/inode.c               |  4 +++-
 fs/ioctl.c               | 46 +++++++++++++++++++++++++++++++++-------
 include/linux/fileattr.h | 23 +++++++++++++++++++-
 include/uapi/linux/fs.h  |  3 ++-
 4 files changed, 65 insertions(+), 11 deletions(-)

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2.34.1