Hi, [This basically is a resend of https://www.spinics.net/lists/fio/msg08165.html.] I've run into a verify issue with fio in xfstest generic/300 [*]: The filesystem I'm running this on has a block size of 1k, on a current mainline kernel and with current fio. The aio-dio-verifier thread in that test case writes 4k buffers and then reads them back in. The test case is designed to run the filesystem out of space. When that happens, some writes can end up short. That doesn't seem to happen on ext4 or xfs filesystems with a block size of 1k, possibly just because the test always runs on a scratch filesystem, but it does happen on gfs2. When the aio-dio-verifier thread reads the buffer of such a short write back in, part of the buffer will lie in a hole and be zero-filled, so verification will fail. Any thoughts? Thanks, Andreas [*] https://git.kernel.org/pub/scm/fs/xfs/xfstests-dev.git/tree/tests/generic/300