filecore_map
return filecore_map(fcmp, ip->i_dirent.addr, lbn, ap->a_bnp);
error = filecore_map(fcmp, addr, 0, &bn);
error = filecore_map(ip->i_mnt, ip->i_dirent.addr,
int filecore_map(struct filecore_mnt *, u_int32_t, daddr_t, daddr_t *);