From: Ming Lei ming.lei@redhat.com
commit 0c6af1ccd5fd9ac640aef01c8de0043837451a04 upstream
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: de1482974080(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 Signed-off-by: Jack Wang jinpu.wang@profitbricks.com --- block/blk-mq.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c index b490a1c2acc8..657cfde50cda 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -1066,8 +1066,10 @@ 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);