get rid of full-hash scan on detaching vfsmounts

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/pnode.h b/fs/pnode.h
index 19b853a3..f4357d3 100644
--- a/fs/pnode.h
+++ b/fs/pnode.h
@@ -31,14 +31,14 @@
 }
 
 void change_mnt_propagation(struct mount *, int);
-int propagate_mnt(struct mount *, struct dentry *, struct mount *,
+int propagate_mnt(struct mount *, struct mountpoint *, struct mount *,
 		struct list_head *);
 int propagate_umount(struct list_head *);
 int propagate_mount_busy(struct mount *, int);
 void mnt_release_group_id(struct mount *);
 int get_dominating_id(struct mount *mnt, const struct path *root);
 unsigned int mnt_get_count(struct mount *mnt);
-void mnt_set_mountpoint(struct mount *, struct dentry *,
+void mnt_set_mountpoint(struct mount *, struct mountpoint *,
 			struct mount *);
 void release_mounts(struct list_head *);
 void umount_tree(struct mount *, int, struct list_head *);