i_ffs2_size
lastlbn = lblkno(fs, ip->i_ffs2_size);
if (nb != 0 && ip->i_ffs2_size >=
osize = fragroundup(fs, blkoff(fs, ip->i_ffs2_size));
if (ip->i_ffs2_size < (uint64_t)lblktosize(fs, lbn + 1))