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>

block/blk-mq.c

@@ -697,8 +697,8 @@ void blk_mq_start_request(struct request *rq)
 	preempt_disable();
 	write_seqcount_begin(&rq->gstate_seq);
 
-	blk_mq_rq_update_state(rq, MQ_RQ_IN_FLIGHT);
 	blk_add_timer(rq);
+	blk_mq_rq_update_state(rq, MQ_RQ_IN_FLIGHT);
 
 	write_seqcount_end(&rq->gstate_seq);
 	preempt_enable();