+ if (r < 0) {
+ /* The parent can't do name_to_handle_at() but the
+ * directory we are interested in can? If so, it must
+ * be a mount point */
+ if (errno == ENOTSUP)
+ return 1;
+
+ return -errno;
+ }
+
+ return mount_id != mount_id_parent;
+
+fallback:
+ if (allow_symlink)
+ r = stat(t, &a);
+ else
+ r = lstat(t, &b);
+