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| author | Jianchao Wang <jianchao.w.wang@oracle.com> | 2019-01-30 17:01:56 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-20 10:20:44 +0100 |
| commit | 883d561c49ebf1d540c3657892995692118afa91 (patch) | |
| tree | 732e0b005b7984196b5b845dda277ad328d38e08 /block | |
| parent | e97773ce1c9e68291332bbb757a433402a72e4a6 (diff) | |
| download | linux-rt-883d561c49ebf1d540c3657892995692118afa91.tar.gz | |
blk-mq: fix a hung issue when fsync
[ Upstream commit 85bd6e61f34dffa8ec2dc75ff3c02ee7b2f1cbce ]
Florian reported a io hung issue when fsync(). It should be
triggered by following race condition.
data + post flush a flush
blk_flush_complete_seq
case REQ_FSEQ_DATA
blk_flush_queue_rq
issued to driver blk_mq_dispatch_rq_list
try to issue a flush req
failed due to NON-NCQ command
.queue_rq return BLK_STS_DEV_RESOURCE
request completion
req->end_io // doesn't check RESTART
mq_flush_data_end_io
case REQ_FSEQ_POSTFLUSH
blk_kick_flush
do nothing because previous flush
has not been completed
blk_mq_run_hw_queue
insert rq to hctx->dispatch
due to RESTART is still set, do nothing
To fix this, replace the blk_mq_run_hw_queue in mq_flush_data_end_io
with blk_mq_sched_restart to check and clear the RESTART flag.
Fixes: bd166ef1 (blk-mq-sched: add framework for MQ capable IO schedulers)
Reported-by: Florian Stecker <m19@florianstecker.de>
Tested-by: Florian Stecker <m19@florianstecker.de>
Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'block')
| -rw-r--r-- | block/blk-flush.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/block/blk-flush.c b/block/blk-flush.c index 4938bec8cfef..6603352879e7 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -402,7 +402,7 @@ static void mq_flush_data_end_io(struct request *rq, blk_status_t error) blk_flush_complete_seq(rq, fq, REQ_FSEQ_DATA, error); spin_unlock_irqrestore(&fq->mq_flush_lock, flags); - blk_mq_run_hw_queue(hctx, true); + blk_mq_sched_restart(hctx); } /** |