On Wed, Feb 03, 2021 at 04:37:29AM -0800, Andres Freund wrote: > Hi, > > On 2020-06-01 19:54:21 +0200, Greg Kroah-Hartman wrote: > > From: Jens Axboe <axboe@xxxxxxxxx> > > > > [ Upstream commit b0beb28097fa04177b3769f4bb7a0d0d9c4ae76e ] > > > > This reverts commit c58c1f83436b501d45d4050fd1296d71a9760bcb. > > > > io_uring does do the right thing for this case, and we're still returning > > -EAGAIN to userspace for the cases we don't support. Revert this change > > to avoid doing endless spins of resubmits. > > > > Cc: stable@xxxxxxxxxxxxxxx # v5.6 > > Reported-by: Bijan Mottahedeh <bijan.mottahedeh@xxxxxxxxxx> > > Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> > > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > > --- > > block/blk-core.c | 11 ++++------- > > 1 file changed, 4 insertions(+), 7 deletions(-) > > > > This broke io_uring direct-io on ext4 over md. > > fallocate -l $((1024*1024*1024)) /srv/part1 > fallocate -l $((1024*1024*1024)) /srv/part2 > losetup -f /srv/part1 > losetup -f /srv/part2 > losetup -a # assuming these were loop0/1 > mdadm --create -n2 -l stripe -N fast-striped /dev/md/fast-striped /dev/loop0 /dev/loop1 > mkfs.ext4 /dev/md/fast-striped > mount /dev/md/fast-striped /mnt/t2 > fio --directory=/mnt/t2 --ioengine io_uring --rw write --filesize 1MB --overwrite=1 --name=test --direct=1 --bs=4k > > On v5.4.43-101-gbba91cdba612 this fails with > fio: io_u error on file /mnt/t2/test.0.0: Input/output error: write offset=0, buflen=4096 > fio: pid=734, err=5/file:io_u.c:1834, func=io_u error, error=Input/output error > > whereas previously it worked. libaio still works... > > I haven't checked which major kernel version fixed this again, but I did > verify that it's still broken in 5.4.94 and that 5.10.9 works. > > I would suspect it's > > commit 4503b7676a2e0abe69c2f2c0d8b03aec53f2f048 > Author: Jens Axboe <axboe@xxxxxxxxx> > Date: 2020-06-01 10:00:27 -0600 > > io_uring: catch -EIO from buffered issue request failure > > -EIO bubbles up like -EAGAIN if we fail to allocate a request at the > lower level. Play it safe and treat it like -EAGAIN in terms of sync > retry, to avoid passing back an errant -EIO. > > Catch some of these early for block based file, as non-mq devices > generally do not support NOWAIT. That saves us some overhead by > not first trying, then retrying from async context. We can go straight > to async punt instead. > > Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> > > > which isn't in stable/linux-5.4.y Can you test that if the above commit is added, all works well again? thanks, greg k-h
