ffs_getdb
error = ffs_realloccg(ip, nb, ffs_getdb(fs, ip, nb),
ffs_getdb(fs, ip, lbn),
error = ffs_realloccg(ip, nb, ffs_getdb(fs, ip, lbn),
ffs_getdb(fs, ip, lbn),
bn = ffs_getdb(fs, oip, i);
bn = ffs_getdb(fs, oip, lastblock);