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author | Alan Jenkins <alan.christopher.jenkins@gmail.com> | 2018-04-12 19:11:58 +0100 |
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committer | Jens Axboe <axboe@kernel.dk> | 2018-04-14 13:54:33 -0600 |
commit | 1dc3039bc87ae7d19a990c3ee71cfd8a9068f428 (patch) | |
tree | 8cb8a4301b52c5838f0a5d3c05e18469079a36d2 /drivers/infiniband | |
parent | 48023102b7078a6674516b1fe0d639669336049d (diff) | |
download | op-kernel-dev-1dc3039bc87ae7d19a990c3ee71cfd8a9068f428.zip op-kernel-dev-1dc3039bc87ae7d19a990c3ee71cfd8a9068f428.tar.gz |
block: do not use interruptible wait anywhere
When blk_queue_enter() waits for a queue to unfreeze, or unset the
PREEMPT_ONLY flag, do not allow it to be interrupted by a signal.
The PREEMPT_ONLY flag was introduced later in commit 3a0a529971ec
("block, scsi: Make SCSI quiesce and resume work reliably"). Note the SCSI
device is resumed asynchronously, i.e. after un-freezing userspace tasks.
So that commit exposed the bug as a regression in v4.15. A mysterious
SIGBUS (or -EIO) sometimes happened during the time the device was being
resumed. Most frequently, there was no kernel log message, and we saw Xorg
or Xwayland killed by SIGBUS.[1]
[1] E.g. https://bugzilla.redhat.com/show_bug.cgi?id=1553979
Without this fix, I get an IO error in this test:
# dd if=/dev/sda of=/dev/null iflag=direct & \
while killall -SIGUSR1 dd; do sleep 0.1; done & \
echo mem > /sys/power/state ; \
sleep 5; killall dd # stop after 5 seconds
The interruptible wait was added to blk_queue_enter in
commit 3ef28e83ab15 ("block: generic request_queue reference counting").
Before then, the interruptible wait was only in blk-mq, but I don't think
it could ever have been correct.
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: stable@vger.kernel.org
Signed-off-by: Alan Jenkins <alan.christopher.jenkins@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/infiniband')
0 files changed, 0 insertions, 0 deletions