Commit ad103e79 authored May 29, 2018 by Keith Busch Committed by Jens Axboe May 29, 2018

blk-mq: Fix timeout and state order



The block layer had been setting the state to in-flight prior to updating
the timer. This is the wrong order since the timeout handler could observe
the in-flight state with the older timeout, believing the request had
expired when in fact it is just getting started.

Signed-off-by: Keith Busch <keith.busch@intel.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent 01fc27d9

block/blk-mq.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -697,8 +697,8 @@ void blk_mq_start_request(struct request *rq)
	preempt_disable();		preempt_disable();
	write_seqcount_begin(&rq->gstate_seq);		write_seqcount_begin(&rq->gstate_seq);

	blk_mq_rq_update_state(rq, MQ_RQ_IN_FLIGHT);
	blk_add_timer(rq);		blk_add_timer(rq);
			blk_mq_rq_update_state(rq, MQ_RQ_IN_FLIGHT);

	write_seqcount_end(&rq->gstate_seq);		write_seqcount_end(&rq->gstate_seq);
	preempt_enable();		preempt_enable();