From 59978bf02691a64008d045c898c870df550dfe41 Mon Sep 17 00:00:00 2001
From: Li Zefan <lizf@cn.fujitsu.com>
Date: Sun, 4 Jan 2009 12:00:45 -0800
Subject: [PATCH] --- yaml --- r: 125728 b: refs/heads/master c:
 7b574b7b0124ed344911f5d581e9bc2d83bbeb19 h: refs/heads/master v: v3

---
 [refs]                | 2 +-
 trunk/kernel/cgroup.c | 6 +++++-
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/[refs] b/[refs]
index dc4ffdd9cbae..91ecaf25ddc7 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 7d3b56ba37a95f1f370f50258ed3954c304c524b
+refs/heads/master: 7b574b7b0124ed344911f5d581e9bc2d83bbeb19
diff --git a/trunk/kernel/cgroup.c b/trunk/kernel/cgroup.c
index 48348dde6d81..891a84eb9d30 100644
--- a/trunk/kernel/cgroup.c
+++ b/trunk/kernel/cgroup.c
@@ -2945,7 +2945,11 @@ int cgroup_clone(struct task_struct *tsk, struct cgroup_subsys *subsys,
 	parent = task_cgroup(tsk, subsys->subsys_id);
 
 	/* Pin the hierarchy */
-	atomic_inc(&parent->root->sb->s_active);
+	if (!atomic_inc_not_zero(&parent->root->sb->s_active)) {
+		/* We race with the final deactivate_super() */
+		mutex_unlock(&cgroup_mutex);
+		return 0;
+	}
 
 	/* Keep the cgroup alive */
 	get_css_set(cg);