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authorMing Lei <ming.lei@redhat.com>2017-11-08 09:11:22 +0800
committerJens Axboe <axboe@kernel.dk>2017-11-10 19:53:25 -0700
commit0c6af1ccd5fd9ac640aef01c8de0043837451a04 (patch)
treee367c79457485a183e6231868fa5fb8fce2b2e40
parentf00c4d80ffdac9e3a64947ebd57489f3232d5a74 (diff)
blk-mq: put driver tag if dispatch budget can't be got
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>
-rw-r--r--block/blk-mq.c4
1 files changed, 3 insertions, 1 deletions
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);