[PATCH v2 0/4] vfs: clean up SETFLAGS and FSSETXATTR option processing

[Darrick J. Wong]

Hi all,

The FS_IOC_SETFLAGS and FS_IOC_FSSETXATTR ioctls were promoted from ext4
and XFS, respectively, into the VFS.  However, we didn't promote any of
the parameter checking code from those filesystems, which lead to a mess
where each filesystem open-codes whatever parameter checks they want and
the behavior across filesystems is no longer consistent.

Therefore, create some generic checking functions in the VFS and remove
all the open-coded pieces in each filesystem.  This preserves the
current behavior where a filesystem can choose to ignore fields it
doesn't understand.

If you're going to start using this mess, you probably ought to just
pull from my git trees, which are linked below.

This has been lightly tested with fstests.  Enjoy!
Comments and questions are, as always, welcome.

--D

kernel git tree:
https://git.kernel.org/cgit/linux/kernel/git/djwong/xfs-linux.git/log/?h=file-ioctl-cleanups