LDL_USABLE_BSIZE
LDL_USABLE_BSIZE);
ul->un_maxresv = btodb(ul->un_logsize) * LDL_USABLE_BSIZE;
st = (sect_trailer_t *)(bp->b_un.b_addr + LDL_USABLE_BSIZE);
#define NB_LEFT_IN_SECTOR(off) (LDL_USABLE_BSIZE - ((off) - dbtob(btodb(off))))