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.
Signed-off-by: Ming Lei <[email protected]> --- 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 c501cbd0de93..3d759bb8a5bb 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -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); -- 2.9.5
