get_last_possible_lba
nblks_avail = get_last_possible_lba(target);
cap = get_last_possible_lba(target);
uint32_t get_last_possible_lba(cd_device *dev);
if ((blks_avail = get_last_possible_lba(target)) == 0) {
if ((cap = get_last_possible_lba(target)) <= 0) {