[PATCHBOMB v30.10] xfsprogs-6.10: filesystem properties

["Darrick J. Wong" <djwong@kernel.org>]

Hi all,

After recent discussions about how to allow sysadmins to opt in or out
of automatick fsck for XFS[1][2], I now have a patchset for xfsprogs
6.10 that implements the filesystem properties that we talked about.

As a refresher, the design I settled on is to add ATTR_ROOT (aka
"trusted") xattrs to the root directory.  ATTR_ROOT xattrs can only be
accessed by processes with CAP_SYS_ADMIN, so unprivileged userspace
can't mess with the sysadmin's configured preferences.

I decided that all fs properties should have "xfs:" in the name to make
them look distinct, and defined "trusted.xfs:autofsck" as the property
that controls the behavior of automatic fsck.  There's a new wrapper
program "xfs_property" that one can use to administer the properties.
xfs_scrub{,bed} uses the property; and mkfs.xfs can set it for you at
format time.

# mkfs.xfs -m autofsck /dev/sda

# xfs_property /dev/sda get autofsck
repair

# mount /dev/sda /mnt

# xfs_property /mnt set autofsck=check

# xfs_scrub -o autofsck /mnt
Info: /mnt: Checking per autofsck directive.

--D

[1] https://lore.kernel.org/linux-xfs/20240724213852.GA612460@frogsfrogsfrogs/
[2] https://lore.kernel.org/linux-xfs/20240730031030.GA6333@frogsfrogsfrogs/