diff --git a/fs/mount.h b/fs/mount.h
index 68bb03e..f82c628 100644
--- a/fs/mount.h
+++ b/fs/mount.h
@@ -87,6 +87,15 @@
 
 extern bool legitimize_mnt(struct vfsmount *, unsigned);
 
+extern void __detach_mounts(struct dentry *dentry);
+
+static inline void detach_mounts(struct dentry *dentry)
+{
+	if (!d_mountpoint(dentry))
+		return;
+	__detach_mounts(dentry);
+}
+
 static inline void get_mnt_ns(struct mnt_namespace *ns)
 {
 	atomic_inc(&ns->count);