mt_map
struct mt_map *mtm = ul->un_logmap; /* Log map */
struct mt_map *un_deltamap; /* deltamap */
struct mt_map *un_logmap; /* logmap includes moby trans stuff */
struct mt_map *un_matamap; /* optional - matamap */
extern void logmap_make_space(struct mt_map *, ml_unit_t *,