Commit 0c6af1cc authored Nov 08, 2017 by Ming Lei Committed by Jens Axboe Nov 10, 2017

blk-mq: put driver tag if dispatch budget can't be got



We have to put the driver tag if dispatch budget can't be got, otherwise
it might cause IO deadlock, especially in case that size of tags is very
small.

Fixes: de148297(blk-mq: introduce .get_budget and .put_budget in blk_mq_ops)
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent f00c4d80

block/blk-mq.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -1080,8 +1080,10 @@ bool blk_mq_dispatch_rq_list(struct request_queue q, struct list_head list,
		}
		}

		if (!got_budget && !blk_mq_get_dispatch_budget(hctx))
		if (!got_budget && !blk_mq_get_dispatch_budget(hctx)) {
		blk_mq_put_driver_tag(rq);
		break;
		}

		list_del_init(&rq->queuelist);

Admin message