blk-mq: return when hctx is stopped in blk_mq_run_work_fn

Jianchao Wang · axboe · commit 0196d6b4088f · 2018-06-04T12:10:40.000-06:00
If a hardware queue is stopped, it should not be run again before explicitly started. Ignore stopped queues in blk_mq_run_work_fn(), fixing a regression recently introduced when the START_ON_RUN bit was removed. Fixes: 15fe8a9 ("blk-mq: remove blk_mq_delay_queue()") Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Jianchao Wang <jianchao.w.wang@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/block/blk-mq.c b/block/blk-mq.c
@@ -1475,7 +1475,7 @@ static void blk_mq_run_work_fn(struct work_struct *work)
 	 * If we are stopped, don't run the queue.
 	 */
 	if (test_bit(BLK_MQ_S_STOPPED, &hctx->state))
-		clear_bit(BLK_MQ_S_STOPPED, &hctx->state);
+		return;
 
 	__blk_mq_run_hw_queue(hctx);
 }

Original file line number	Diff line number	Diff line change
`@@ -1475,7 +1475,7 @@ static void blk_mq_run_work_fn(struct work_struct *work)`
`1475`	`1475`	`* If we are stopped, don't run the queue.`
`1476`	`1476`	`*/`
`1477`	`1477`	`if (test_bit(BLK_MQ_S_STOPPED, &hctx->state))`
`1478`		`- clear_bit(BLK_MQ_S_STOPPED, &hctx->state);`
	`1478`	`+ return;`
`1479`	`1479`
`1480`	`1480`	`__blk_mq_run_hw_queue(hctx);`
`1481`	`1481`	`}`