Re: [PATCH v2] tests/xfs: test COW writeback failure when overlapping non-shared blocks

On Mon, Oct 25, 2021 at 09:10:22AM -0700, Darrick J. Wong wrote:

On Mon, Oct 25, 2021 at 09:00:53AM -0400, Brian Foster wrote:

quoted

Test that COW writeback that overlaps non-shared delalloc blocks
does not leave around stale delalloc blocks on I/O failure. This
triggers assert failures and free space accounting corruption on
XFS.

Signed-off-by: Brian Foster <redacted>

LGTM.  Thanks for the patch + reproducer!

At some point this test ought to grow a link to the upstream fix patch,
which is currently in the 5.16 merge branch, e.g.:

# Regression test for kernel commit:
#
# 5ca5916b6bc9 ("xfs: punch out data fork delalloc blocks on COW
# writeback failure")

And this test triggers an ASSERT (though it won't crash the kernel
unless XFS_ASSERT_FATAL is set), I'd like wait for the fix to land so we
could have the correct commit ID by then.

...but as Sunday afternoon came and went with neither -rc7 nor a final
release being tagged, I'm not sure when that commit will appear
upstream.  It's entirely possible that Linus is sitting in the dark
right now, since I came back from my long weekend to a noticeable
amount of downed trees around town.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>

Thanks for the review, and for all the other reviews!

Eryu