diff --git a/fs/ocfs2/stack_user.c b/fs/ocfs2/stack_user.c
index b503772..cd12001 100644
--- a/fs/ocfs2/stack_user.c
+++ b/fs/ocfs2/stack_user.c
@@ -21,6 +21,7 @@
 #include <linux/fs.h>
 #include <linux/miscdevice.h>
 #include <linux/mutex.h>
+#include <linux/smp_lock.h>
 #include <linux/reboot.h>
 #include <asm/uaccess.h>
 
@@ -619,10 +620,12 @@
 		return -ENOMEM;
 	p->op_this_node = -1;
 
+	lock_kernel();
 	mutex_lock(&ocfs2_control_lock);
 	file->private_data = p;
 	list_add(&p->op_list, &ocfs2_control_private_list);
 	mutex_unlock(&ocfs2_control_lock);
+	unlock_kernel();
 
 	return 0;
 }