un_tail_lof
off_t tail = ul->un_tail_lof;
me->me_lof = ul->un_tail_lof;
me->me_lof = ul->un_tail_lof;
new_lof = ul->un_tail_lof;
ul->un_tail_lof = dbtob(btodb(ul->un_head_lof));
ul->un_head_lof = ul->un_tail_lof;
ul->un_tail_lof = new_lof;
ASSERT(ul->un_head_lof != ul->un_tail_lof);
if (ul->un_head_lof < ul->un_tail_lof) {
(ul->un_tail_lof - ul->un_head_lof))) {
if (OVERLAP(*lofp, nb, ul->un_tail_lof,
(ul->un_head_lof - ul->un_tail_lof))) {
ul->un_tail_lof = dbtob(btodb(ul->un_head_lof)) - DEV_BSIZE;
if (ul->un_tail_lof < ul->un_bol_lof)
ul->un_tail_lof = ul->un_eol_lof - DEV_BSIZE;
if (ul->un_tail_lof >= ul->un_eol_lof)
ul->un_tail_lof = ul->un_bol_lof;
tail = ul->un_tail_lof;
inval_range(ul, cb, ul->un_tail_lof, 1);
bp->b_blkno = btodb(ul->un_tail_lof);
ASSERT(dbtob(bp->b_blkno) == ul->un_tail_lof);
rlof = ul->un_tail_lof;
ul->un_tail_lof += copy_nb;
ul->un_tail_lof += sizeof (sect_trailer_t);
if (ul->un_tail_lof == ul->un_eol_lof) {
ul->un_tail_lof = ul->un_bol_lof;
ul->un_tail_lof = dbtob(bp->b_blkno) + bcount;
if (ul->un_tail_lof == ul->un_eol_lof) {
ul->un_tail_lof = ul->un_bol_lof;
ASSERT(ul->un_tail_lof != ul->un_head_lof);
if (ul->un_head_lof <= ul->un_tail_lof)
(ul->un_eol_lof - ul->un_tail_lof);
nfb = ul->un_head_lof - ul->un_tail_lof;
while (lof != ul->un_tail_lof) {
#define ldl_empty(ul) ((ul)->un_head_lof == (ul)->un_tail_lof)