+ if (nosupp)
+ /* Neither parent nor child do name_to_handle_at()?
+ We have no choice but to fall back. */
+ goto fallback;
+ else
+ /* The parent can't do name_to_handle_at() but
+ * the directory we are interested in can?
+ * Or the other way around?
+ * If so, it must be a mount point. */
+ return 1;
+ else
+ return -errno;
+ else
+ return mount_id != mount_id_parent;