From 839ec5452ebfd5905b9c69b20ceb640903a8ea1a Mon Sep 17 00:00:00 2001 From: Paul Menage Date: Thu, 29 Jan 2009 14:25:22 -0800 Subject: cgroup: fix root_count when mount fails due to busy subsystem root_count was being incremented in cgroup_get_sb() after all error checking was complete, but decremented in cgroup_kill_sb(), which can be called on a superblock that we gave up on due to an error. This patch changes cgroup_kill_sb() to only decrement root_count if the root was previously linked into the list of roots. Signed-off-by: Paul Menage Tested-by: Serge Hallyn Cc: Ingo Molnar Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cgroup.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 492215d67fa5..5a54ff42874e 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -1115,8 +1115,10 @@ static void cgroup_kill_sb(struct super_block *sb) { } write_unlock(&css_set_lock); - list_del(&root->root_list); - root_count--; + if (!list_empty(&root->root_list)) { + list_del(&root->root_list); + root_count--; + } mutex_unlock(&cgroup_mutex); -- cgit v1.2.3-59-g8ed1b