btree_last
val = btree_last(&head->h, &btree_geo128, (unsigned long *)&key[0]);
return btree_last(&head->h, BTREE_TYPE_GEO, (unsigned long *)key);
void *val = btree_last(&head->h, BTREE_TYPE_GEO, &_key);
void *btree_last(struct btree_head *head, struct btree_geo *geo,
EXPORT_SYMBOL_GPL(btree_last);
val = btree_last(victim, geo, key);