[PATCH] blkcg: fix memleak for iolatency

[Yufen Yu <yuyufen@huawei.com>]

Normally, blkcg_iolatency_exit() will free related memory in iolatency
when cleanup queue. But if blk_throtl_init() return error and queue init
fail, blkcg_iolatency_exit() will not do that for us. Then it cause
memory leak.

Fixes: d70675121546 ("block: introduce blk-iolatency io controller")
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
---
 block/blk-cgroup.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 619a79b51068..6f91b2ae0b27 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -1152,15 +1152,17 @@ int blkcg_init_queue(struct request_queue *q)
 	if (preloaded)
 		radix_tree_preload_end();
 
-	ret = blk_iolatency_init(q);
-	if (ret)
-		goto err_destroy_all;
-
 	ret = blk_throtl_init(q);
 	if (ret)
 		goto err_destroy_all;
 	return 0;
 
+	ret = blk_iolatency_init(q);
+	if (ret) {
+		blk_throtl_exit(q);
+		goto err_destroy_all;
+	}
+
 err_destroy_all:
 	blkg_destroy_all(q);
 	return ret;
-- 
2.25.4