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

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>

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 8e56884fd2e92643f1f7ecc32380ea245740c610..a7785df2c94462b9fb9d18faa2fcecb8c4fd8dfd 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -1222,8 +1222,10 @@ 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)) {
                        /*