udf_bmap_internal
error = udf_bmap_internal(up, offset, §or, &max_size);
int udf_bmap_internal(struct unode *, off_t, daddr_t *, uint32_t *);
if (udf_bmap_internal(up, bp->b_lblkno * up->u_ump->um_bsize,
error = udf_bmap_internal(up, ap->a_bn * up->u_ump->um_bsize,