Re: attr fork related fstests failures on for-next

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

On Mon, Mar 29, 2021 at 02:16:04PM -0400, Brian Foster wrote:
> Hi,
> 
> I'm seeing a couple different fstests failures on current for-next that
> appear to be associated with e6a688c33238 ("xfs: initialise attr fork on
> inode create"). The first is xfs_check complaining about sb versionnum
> bits on various tests:
> 
> generic/003 16s ... _check_xfs_filesystem: filesystem on /dev/mapper/test-scratch is inconsistent (c)
> (see /root/xfstests-dev/results//generic/003.full for details)
> # cat results/generic/003.full
> ...
> _check_xfs_filesystem: filesystem on /dev/mapper/test-scratch is inconsistent (c)
> *** xfs_check output ***
> sb versionnum missing attr bit 10
> *** end xfs_check output

FWIW I think this because that commit sets up an attr fork without
setting ATTR and ATTR2 in sb_version like xfs_bmap_add_attrfork does...

> ...
> #
> 
> With xfs_check bypassed, repair eventually complains about some attr
> forks. The first point I hit this variant is generic/117:
> 
> generic/117 9s ... _check_xfs_filesystem: filesystem on /dev/mapper/test-scratch is inconsistent (r)
> (see /root/xfstests-dev/results//generic/117.full for details)
> # cat results//generic/117.full
> ...
> _check_xfs_filesystem: filesystem on /dev/mapper/test-scratch is inconsistent (r)
> *** xfs_repair -n output ***
> ...
> Phase 3 - for each AG...
>         - scan (but don't clear) agi unlinked lists...
>         - process known inodes and perform inode discovery...
>         - agno = 0
> bad attr fork offset 24 in dev inode 135, should be 1
> would have cleared inode 135
> bad attr fork offset 24 in dev inode 142, should be 1
> would have cleared inode 142

...and I think this is because xfs_default_attroffset doesn't set the
correct value for device files.  For those kinds of files, xfs_repair
requires the data fork to be exactly 8 bytes.

--D

> ...
> 
> Both problems disappear with e6a688c33238 reverted.
> 
> Brian
>