un_head_lof
head = ul->un_head_lof;
off_t head = ul->un_head_lof;
if (new_lof == ul->un_head_lof)
if (new_lof > ul->un_head_lof) {
nb = new_lof - ul->un_head_lof;
inval_range(ul, &ul->un_wrbuf, ul->un_head_lof, nb);
inval_range(ul, &ul->un_rdbuf, ul->un_head_lof, nb);
beg_blkno = btodb(ul->un_head_lof);
nb = ul->un_eol_lof - ul->un_head_lof;
inval_range(ul, &ul->un_wrbuf, ul->un_head_lof, nb);
inval_range(ul, &ul->un_rdbuf, ul->un_head_lof, nb);
beg_blkno = btodb(ul->un_head_lof);
ul->un_head_lof = new_lof;
ul->un_tail_lof = dbtob(btodb(ul->un_head_lof));
ul->un_head_lof = ul->un_tail_lof;
ASSERT(new_lof != dbtob(btodb(ul->un_head_lof)));
if (new_lof > ul->un_head_lof) {
beg_blkno = btodb(ul->un_head_lof);
beg_blkno = btodb(ul->un_head_lof);
if (bp->b_blkno >= btodb(ul->un_head_lof)) {
ident += (bp->b_blkno - btodb(ul->un_head_lof));
ident += (btodb(ul->un_eol_lof) - btodb(ul->un_head_lof));
ASSERT(ul->un_head_lof != ul->un_tail_lof);
if (ul->un_head_lof < ul->un_tail_lof) {
if (!WITHIN(*lofp, nb, ul->un_head_lof,
(ul->un_tail_lof - ul->un_head_lof))) {
(ul->un_head_lof - ul->un_tail_lof))) {
ul->un_tail_lof = dbtob(btodb(ul->un_head_lof)) - DEV_BSIZE;
head = ul->un_head_lof;
ASSERT(ul->un_tail_lof != ul->un_head_lof);
if (ul->un_head_lof <= ul->un_tail_lof)
nfb = (ul->un_head_lof - ul->un_bol_lof) +
nfb = ul->un_head_lof - ul->un_tail_lof;
lof = ul->un_head_lof;
#define ldl_empty(ul) ((ul)->un_head_lof == (ul)->un_tail_lof)