path: root/block
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authorJianchao Wang <jianchao.w.wang@oracle.com>2019-01-30 17:01:56 +0800
committerJens Axboe <axboe@kernel.dk>2019-01-30 08:53:54 -0700
commit85bd6e61f34dffa8ec2dc75ff3c02ee7b2f1cbce (patch)
tree62e799a9a8bf88ef4831a9ffc865fd33f3e3f36c /block
parent2e3c18d0ada16f145087b2687afcad1748c0827c (diff)
blk-mq: fix a hung issue when fsync
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>
Diffstat (limited to 'block')
1 files changed, 1 insertions, 1 deletions
diff --git a/block/blk-flush.c b/block/blk-flush.c
index a3fc7191c694..6e0f2d97fc6d 100644
--- a/block/blk-flush.c
+++ b/block/blk-flush.c
@@ -335,7 +335,7 @@ 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);