vfs: remove lives_below_in_same_fs()

Remove lives_below_in_same_fs() since is_subdir() from fs/dcache.c is
providing the same functionality.
Signed-off-by: Jan Blunck <jblunck@suse.de>
Acked-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/namespace.c

@@ -1176,17 +1176,6 @@ static int mount_is_safe(struct nameidata *nd)
 #endif
 }
 
-static int lives_below_in_same_fs(struct dentry *d, struct dentry *dentry)
-{
-	while (1) {
-		if (d == dentry)
-			return 1;
-		if (d == NULL || d == d->d_parent)
-			return 0;
-		d = d->d_parent;
-	}
-}
-
 struct vfsmount *copy_tree(struct vfsmount *mnt, struct dentry *dentry,
 					int flag)
 {
@@ -1203,7 +1192,7 @@ struct vfsmount *copy_tree(struct vfsmount *mnt, struct dentry *dentry,
 
 	p = mnt;
 	list_for_each_entry(r, &mnt->mnt_mounts, mnt_child) {
-		if (!lives_below_in_same_fs(r->mnt_mountpoint, dentry))
+		if (!is_subdir(r->mnt_mountpoint, dentry))
 			continue;
 
 		for (s = r; s; s = next_mnt(s, r)) {