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@xxxxxxxxxx>
---
V2:
add Fixes tag
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
