From: Ming Lei <ming.lei@redhat.com>
Date: Wed, 8 Nov 2017 09:11:22 +0800
Subject: [PATCH] blk-mq: put driver tag if dispatch budget can't be got
Git-commit: 0c6af1ccd5fd9ac640aef01c8de0043837451a04
Patch-mainline: v4.15-rc1
References: bsc#1104967,FATE#325924
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>
Acked-by: Hannes Reinecke <hare@suse.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 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);
--
2.16.4