From: Tejun Heo <tj@kernel.org>
Date: Sat, 8 Feb 2014 15:26:33 +0000 (-0500)
Subject: cgroup: fix error return value in cgroup_mount()
X-Git-Tag: v3.12.14~79
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=7737f595e8f566d41ef9f91246816bfbed4b7a87;p=thirdparty%2Fkernel%2Fstable.git

cgroup: fix error return value in cgroup_mount()

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: Jiri Slaby <jslaby@suse.cz>
---

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index b6fd78344c53c..8ea46f2c4b515 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1612,10 +1612,10 @@ static struct dentry *cgroup_mount(struct file_system_type *fs_type,
 		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;