PowerMax driver - do an rdf_group check earlier

When creating a replicated volume we first create a source volume
before checking that an rdf_group exists.  If an rdf_group does not
exist a lengthy rollback is initiated.  This fix prevents that.

Change-Id: I432cb8c904536d63c1877ee0768f2b979723bc3c

cinder/tests/unit/volume/drivers/dell_emc/powermax/test_powermax.py

@@ -8325,6 +8325,33 @@ class PowerMaxCommonReplicationTest(test.TestCase):
         self.common.create_volume(self.data.test_volume_group_member)
         mock_add.assert_called_once()
 
+    @mock.patch.object(
+        common.PowerMaxCommon, '_replicate_volume',
+        return_value=({
+            'replication_driver_data':
+                PowerMaxCommonData.test_volume.replication_driver_data}, {}))
+    @mock.patch.object(utils.PowerMaxUtils, 'is_replication_enabled',
+                       return_value=True)
+    @mock.patch.object(rest.PowerMaxRest, 'get_rdf_group_number',
+                       side_effect=['4', None])
+    def test_create_replicated_vol_side_effect(
+            self, mock_rdf_no, mock_rep_enabled, mock_rep_vol):
+        self.common.rep_config = self.utils.get_replication_config(
+            [self.replication_device])
+        ref_rep_data = {'array': six.text_type(self.data.remote_array),
+                        'device_id': self.data.device_id2}
+        ref_model_update = {
+            'provider_location': six.text_type(
+                self.data.test_volume.provider_location),
+            'replication_driver_data': six.text_type(ref_rep_data)}
+
+        model_update = self.common.create_volume(self.data.test_volume)
+        self.assertEqual(ref_model_update, model_update)
+
+        self.assertRaises(exception.VolumeBackendAPIException,
+                          self.common.create_volume,
+                          self.data.test_volume)
+
     def test_create_cloned_replicated_volume(self):
         extra_specs = deepcopy(self.extra_specs)
         extra_specs[utils.PORTGROUPNAME] = self.data.port_group_name_f

cinder/volume/drivers/dell_emc/powermax/common.py

@@ -419,6 +419,10 @@ class PowerMaxCommon(object):
         group_name = None
         group_id = None
         extra_specs = self._initial_setup(volume)
+        # Check if the RDF group is valid
+        if self.utils.is_replication_enabled(extra_specs):
+            self.get_rdf_details(extra_specs[utils.ARRAY])
+
         if 'qos' in extra_specs:
             del extra_specs['qos']