Yes, xfstests exists. I've used it myself and it's actually pretty good for a suite that doesn't include error injection. But part of today's story is that xfst

Yes, xfstests exists. I've used it myself and it's actually pretty good for a suite that doesn't include error injection. But part of today's story is that xfstests wasn't being updated to cover the last several features that were added to XFS. The result is exactly the kind of brittleness that is characteristic of poorly tested software. Something else changed, and previously latent bugs started popping out of the rotten woodwork.