wapbl_circ_advance
wapbl_circ_advance(wr, fsblklen, offp);
wapbl_circ_advance(wr, wcn->wc_len, &saveoff);
wapbl_circ_advance(wr,
wapbl_circ_advance(wr, logblklen,
wapbl_circ_advance(wr,
wapbl_circ_advance(wr, wcn->wc_len, &saveoff);