+/* This optional item might follow an F_HL_*() item.
+ * (Note: a device doesn't need to check LEN64_BUMP(f).) */
+#define F_RDEV_P(f) (&OPT_EXTRA(f, HLINK_BUMP(f) + 2 - 1)->unum)
+
+/* The sum is only present on regular files. */
+#define F_SUM(f) ((const char*)OPT_EXTRA(f, LEN64_BUMP(f) + HLINK_BUMP(f) \
+ + SUM_EXTRA_CNT - 1))
+
+/* Some utility defines: */
+#define F_IS_ACTIVE(f) (f)->basename[0]
+#define F_IS_HLINKED(f) ((f)->flags & FLAG_HLINKED)
+
+#define F_HLINK_NOT_FIRST(f) BITS_SETnUNSET((f)->flags, FLAG_HLINKED, FLAG_HLINK_FIRST)
+#define F_HLINK_NOT_LAST(f) BITS_SETnUNSET((f)->flags, FLAG_HLINKED, FLAG_HLINK_LAST)
+
+#define F_UID(f) ((uid_t)F_OWNER(f))
+#define F_GID(f) ((gid_t)F_GROUP(f))
+
+#define DEV_MAJOR(a) (a)[0]
+#define DEV_MINOR(a) (a)[1]
+
+#define DIR_PARENT(a) (a)[0]
+#define DIR_FIRST_CHILD(a) (a)[1]
+#define DIR_NEXT_SIBLING(a) (a)[2]
+
+/*
+ * Start the flist array at FLIST_START entries and grow it
+ * by doubling until FLIST_LINEAR then grow by FLIST_LINEAR
+ */
+#define FLIST_START (32 * 1024)
+#define FLIST_LINEAR (FLIST_START * 512)