blk-mq: Put driver tag in blk_mq_dispatch_rq_list() when no budget

[ Upstream commit 5fe56de799ad03e92d794c7936bf363922b571df ]

If in blk_mq_dispatch_rq_list() we find no budget, then we break of the
dispatch loop, but the request may keep the driver tag, evaulated
in 'nxt' in the previous loop iteration.

Fix by putting the driver tag for that request.

Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index a8c1a45cedde092969ae92da5a347a60c5044f63..757c0fd9f0cc22d5cb5f473dadb5c2581c3baee6 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1232,8 +1232,10 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list,
                rq = list_first_entry(list, struct request, queuelist);
 
                hctx = rq->mq_hctx;
-               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;
+               }
 
                if (!blk_mq_get_driver_tag(rq)) {
                        /*