I just noticed this test failing on zoned xfs in current for-next. That's because for out of place overwrite file systems writing at ENOSPC will obviously fail, and I think the test acknowledges that by forcing nocow for btrfs. But that leaves "real" out of place write file systems affected, which should also include zone btrfs, but the test actually fails there in mkfs already due to some reason. Can you please rework the patch to see that setting the nocow flag works first and only try with that or something like that?