lfs_update_iaddr
lfs_update_iaddr(fs, ip, LFS_UNUSED_DADDR);
void lfs_update_iaddr(struct lfs *, struct inode *, daddr_t);
lfs_update_iaddr(fs, ip, offset);
lfs_update_iaddr(fs, ip, LFS_DBTOFSB(fs, bp->b_blkno));