diff --git a/include/linux/namespace.h b/include/linux/namespace.h
new file mode 100644
index 0000000..9eca155
--- /dev/null
+++ b/include/linux/namespace.h
@@ -0,0 +1,42 @@
+#ifndef _NAMESPACE_H_
+#define _NAMESPACE_H_
+#ifdef __KERNEL__
+
+#include <linux/mount.h>
+#include <linux/sched.h>
+
+struct namespace {
+	atomic_t		count;
+	struct vfsmount *	root;
+	struct list_head	list;
+	struct rw_semaphore	sem;
+};
+
+extern void umount_tree(struct vfsmount *);
+extern int copy_namespace(int, struct task_struct *);
+extern void __put_namespace(struct namespace *namespace);
+
+static inline void put_namespace(struct namespace *namespace)
+{
+	if (atomic_dec_and_test(&namespace->count))
+		__put_namespace(namespace);
+}
+
+static inline void exit_namespace(struct task_struct *p)
+{
+	struct namespace *namespace = p->namespace;
+	if (namespace) {
+		task_lock(p);
+		p->namespace = NULL;
+		task_unlock(p);
+		put_namespace(namespace);
+	}
+}
+
+static inline void get_namespace(struct namespace *namespace)
+{
+	atomic_inc(&namespace->count);
+}
+
+#endif
+#endif