releases/3.13.6/cgroup-fix-error-return-value-in-cgroup_mount.patch

From eb46bf89696972b856a9adb6aebd5c7b65c266e4 Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Sat, 8 Feb 2014 10:26:33 -0500
Subject: cgroup: fix error return value in cgroup_mount()

From: Tejun Heo <tj@kernel.org>

commit eb46bf89696972b856a9adb6aebd5c7b65c266e4 upstream.

When cgroup_mount() fails to allocate an id for the root, it didn't
set ret before jumping to unlock_drop ending up returning 0 after a
failure.  Fix it.

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 kernel/cgroup.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1580,10 +1580,10 @@ static struct dentry *cgroup_mount(struc
 		mutex_lock(&cgroup_mutex);
 		mutex_lock(&cgroup_root_mutex);
 
-		root_cgrp->id = idr_alloc(&root->cgroup_idr, root_cgrp,
-					   0, 1, GFP_KERNEL);
-		if (root_cgrp->id < 0)
+		ret = idr_alloc(&root->cgroup_idr, root_cgrp, 0, 1, GFP_KERNEL);
+		if (ret < 0)
 			goto unlock_drop;
+		root_cgrp->id = ret;
 
 		/* Check for name clashes with existing mounts */
 		ret = -EBUSY;