[PATCH] blk-mq: Fix memory leak in blk_mq_init_allocated_queue error handling

[zhengbin <zhengbin13@huawei.com>]

If blk_mq_init_allocated_queue->elevator_init_mq fails, need to release
the previously requested resources.

Fixes: d34849913 ("blk-mq-sched: allow setting of default IO scheduler")
Signed-off-by: zhengbin <zhengbin13@huawei.com>
---
 block/blk-mq.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index b038ec6..e001610 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2845,6 +2845,8 @@ static unsigned int nr_hw_queues(struct blk_mq_tag_set *set)
 struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
 						  struct request_queue *q)
 {
+	int ret = -ENOMEM;
+
 	/* mark the queue as mq asap */
 	q->mq_ops = set->ops;

@@ -2906,17 +2908,18 @@ struct request_queue *blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
 	blk_mq_map_swqueue(q);

 	if (!(set->flags & BLK_MQ_F_NO_SCHED)) {
-		int ret;
-
 		ret = elevator_init_mq(q);
 		if (ret)
-			return ERR_PTR(ret);
+			goto err_tag_set;
 	}

 	return q;

+err_tag_set:
+	blk_mq_del_queue_tag_set(q);
 err_hctxs:
 	kfree(q->queue_hw_ctx);
+	q->nr_hw_queues = 0;
 err_sys_init:
 	blk_mq_sysfs_deinit(q);
 err_poll:
--
2.7.4