POINTER_IS_VALID
ASSERT(!POINTER_IS_VALID(dn->dn_objset));
if (!POINTER_IS_VALID(os)) {
ASSERT(!POINTER_IS_VALID(zp->z_zfsvfs));
ASSERT(!POINTER_IS_VALID(zp->z_zfsvfs));
ASSERT(!POINTER_IS_VALID(rootzp->z_zfsvfs));
if (!POINTER_IS_VALID(zfsvfs)) {
ASSERT(!POINTER_IS_VALID(sharezp->z_zfsvfs));
ASSERT(!POINTER_IS_VALID(zp->z_zfsvfs) || (zfsvfs == zp->z_zfsvfs));
ASSERT(!POINTER_IS_VALID(zp->z_zfsvfs));