i_e2fs_gen
ip->i_e2fs_gen = ext2gennumber;
ufhp->ufid_gen = ip->i_e2fs_gen;
if (ip->i_e2fs_gen == 0) {
ip->i_e2fs_gen = ext2gennumber;
ip->i_e2fs_gen != ufhp->ufid_gen) {
vap->va_gen = ip->i_e2fs_gen;