cd9660_lblkno
if (cd9660_lblkno(imp, dp->i_offset) !=
cd9660_lblkno(imp, saveoffset)) {
lbn = cd9660_lblkno(imp, offset);
lbn = cd9660_lblkno(imp, ino);
lbn = cd9660_lblkno(imp, uio->uio_offset);