On 12/21/2017 03:34 AM, Dave Chinner wrote:
On Wed, Dec 20, 2017 at 07:22:44PM +0200, Ari Sundholm wrote:
As recently discussed on the fstests mailing list, the way
generic/399 checks for the filesystem having become full only
works on filesystems that behave like ext4, and even on those,
actually only works by accident.
The problem is that xfs_io does not give a nonzero exit value
when the pwrite operation fails due to ENOSPC. However, if the
filesystem also happens to be unable to create new empty files
when it is full, the check will do its job because open() fails
with ENOSPC. Not all filesystems behave like this, however.
As it seems to be nontrivial to get xfs_io fixed for this case,
I propose simply replacing the xfs_io pwrite command with dd
for now. AFAICS, this works with all filesystems, and should also
preserve the nature of the test case.
Signed-off-by: Ari Sundholm <ari@xxxxxxxxxx>
---
tests/generic/399 | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tests/generic/399 b/tests/generic/399
index 8f5fcdc..5056b20 100755
--- a/tests/generic/399
+++ b/tests/generic/399
@@ -101,7 +101,7 @@ total_file_size=0
i=1
while true; do
file=$SCRATCH_MNT/encrypted_dir/file$i
- if ! $XFS_IO_PROG -f $file -c 'pwrite 0 1M' &> $tmp.out; then
+ if ! dd if=/dev/zero of=$file bs=4k count=256 &> $tmp.out; then
if ! grep -q 'No space left on device' $tmp.out; then
echo "FAIL: unexpected pwrite failure"
cat $tmp.out
NACK.
Please work to get xfs_io fixed - there's been some discussion, a
couple of test patches, and a direction has pretty much been decided
but neither Brian (who is on PTO) or I have had the time to
implement it. If you need it fixed right away then you need to put
the work in rather than wait for other people (who are on holiday
right now) to fit it into their own schedules and priorities.
We are not really in a hurry to get this fixed upstream, as we already
have a local fix suitable for our purposes. This problem was originally
reported to get it eventually fixed for everyone in a way deemed
suitable by upstream. I am not demanding anyone to spend any effort on
this on any timescale. I am sorry if I have somehow given that
impression. I am only trying to help.
What I have understood of the discussion on this list is that the work
to get xfs_io properly fixed is nontrivial and requires quite a lot of
plumbing, requiring familiarity with xfsprogs. Given that the problem is
limited to this test case (no one else has complained), it may not be
necessary to rush to fix it in xfsprogs in the first place. Also, the
desired semantics for failures when multiple commands have been chained
do not seem clear to me, so this may need more thought. Thus, I decided
to suggest to sidestep the problem with a simple change in the test case
itself as an option to save everyone's efforts until a more pressing
need to get xfs_io fixed arises.
Cheers,
Dave.
Thanks,
Ari Sundholm
ari@xxxxxxxxxx
--
To unsubscribe from this list: send the line "unsubscribe fstests" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
