[PATCH] blk-cgroup: fix blkg->online set on radix_tree_insert failure

[Tao Cui <cuitao@kylinos.cn>]

In blkg_create(), blkg->online was set to true unconditionally outside
the radix_tree_insert success check. When the insertion fails, the blkg
is not in the radix tree nor the hash/list, yet it is incorrectly marked
online. This state inconsistency could cause future code paths that
depend on blkg->online to behave incorrectly.

Move blkg->online = true inside the if (likely(!ret)) block so that it
is only set when the blkg is fully initialized and inserted.

Signed-off-by: Tao Cui <cuitao@kylinos.cn>
---
 block/blk-cgroup.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/blk-cgroup.c b/block/blk-cgroup.c
index 554c87bb4a86..539301f4f645 100644
--- a/block/blk-cgroup.c
+++ b/block/blk-cgroup.c
@@ -431,8 +431,8 @@ static struct blkcg_gq *blkg_create(struct blkcg *blkcg, struct gendisk *disk,
 				blkg->pd[i]->online = true;
 			}
 		}
+		blkg->online = true;
 	}
-	blkg->online = true;
 	spin_unlock(&blkcg->lock);
 
 	if (!ret)
-- 
2.43.0