INOCNT
if (ipbuf == NULL || ino < last || ino >= last + INOCNT(super)) {
last = rounddown(ino, INOCNT(super));
&((struct ufs1_dinode *)ipbuf)[ino % INOCNT(super)]);
di2 = &((struct ufs2_dinode *)ipbuf)[ino % INOCNT(super)];
sizeof(struct ufs2_dinode)) * INOCNT(fs))