diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index a7267bf..3fb789f 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -46,6 +46,7 @@
 #include <linux/cgroupstats.h>
 #include <linux/hash.h>
 #include <linux/namei.h>
+#include <linux/smp_lock.h>
 
 #include <asm/atomic.h>
 
@@ -900,6 +901,7 @@
 	struct cgroup *cgrp = &root->top_cgroup;
 	struct cgroup_sb_opts opts;
 
+	lock_kernel();
 	mutex_lock(&cgrp->dentry->d_inode->i_mutex);
 	mutex_lock(&cgroup_mutex);
 
@@ -927,6 +929,7 @@
 	kfree(opts.release_agent);
 	mutex_unlock(&cgroup_mutex);
 	mutex_unlock(&cgrp->dentry->d_inode->i_mutex);
+	unlock_kernel();
 	return ret;
 }