Abort disconnect if invalid udid

The vSCSI physical volume may hit an issue if there is an hdisk without
a UDID.  The connect flow handles this and will not map.  Which then
causes a revert.  However, during the revert the code tries to remove
the hdisk.  This causes a significant issue.

This change set detects this path by adding a flag to check if udid is
None.  If so, it presents a warning message to the operator.  It then
allows the revert flow to continue properly.

Change-Id: If7af35c7e7b68f9a5cf5496fdfded482b45064e0
Closes-Bug: 1505388

nova_powervm/tests/virt/powervm/volume/test_vscsi.py

@@ -253,17 +253,19 @@ class TestVSCSIAdapter(BaseVSCSITest):
         self.assertEqual(1, mock_remove_maps.call_count)
         self.assertEqual(0, self.ft_fx.patchers['update'].mock.call_count)
 
+    @mock.patch('pypowervm.tasks.hdisk.good_discovery')
     @mock.patch('pypowervm.tasks.hdisk.remove_hdisk')
     @mock.patch('pypowervm.wrappers.virtual_io_server.VIOS.hdisk_from_uuid')
     @mock.patch('pypowervm.tasks.scsi_mapper.remove_maps')
     @mock.patch('nova_powervm.virt.powervm.vm.get_vm_id')
     def test_disconnect_volume_no_udid(
             self, mock_get_vm_id, mock_remove_maps, mock_hdisk_from_uuid,
-            mock_remove_hdisk):
+            mock_remove_hdisk, mock_good_discover):
 
         # The mock return values
         mock_hdisk_from_uuid.return_value = 'device_name'
         mock_get_vm_id.return_value = 'partition_id'
+        mock_good_discover.return_value = True
 
         def validate_remove_maps(vios_w, vm_uuid, match_func):
             self.assertIsInstance(vios_w, pvm_vios.VIOS)
@@ -284,6 +286,25 @@ class TestVSCSIAdapter(BaseVSCSITest):
         mock_remove_hdisk.assert_called_once_with(
             self.adpt, mock.ANY, 'dev_name', self.vios_uuid)
 
+    @mock.patch('pypowervm.tasks.hdisk.good_discovery')
+    @mock.patch('pypowervm.tasks.hdisk.remove_hdisk')
+    @mock.patch('pypowervm.tasks.scsi_mapper.remove_maps')
+    def test_disconnect_volume_no_udid_on_discover(
+            self, mock_remove_maps, mock_remove_hdisk, mock_good_discover):
+        """Ensures that if the UDID can not be found, no disconnect."""
+        mock_good_discover.return_value = False
+        with mock.patch.object(
+            self.vol_drv, '_discover_volume_on_vios',
+            return_value=('status', 'dev_name', None)):
+
+            # Run the method
+            self.vol_drv.disconnect_volume()
+
+        # As initialized above, remove_maps returns True to trigger update.
+        self.assertEqual(0, mock_remove_maps.call_count)
+        self.assertEqual(0, self.ft_fx.patchers['update'].mock.call_count)
+        self.assertEqual(0, mock_remove_hdisk.call_count)
+
     @mock.patch('pypowervm.wrappers.virtual_io_server.VIOS.hdisk_from_uuid')
     @mock.patch('pypowervm.tasks.scsi_mapper.remove_maps')
     def test_disconnect_volume_no_valid_vio(self, mock_remove_maps,

nova_powervm/virt/powervm/volume/vscsi.py

@@ -258,6 +258,19 @@ class VscsiVolumeAdapter(v_driver.FibreChannelVolumeAdapter):
                     status, device_name, udid = self._discover_volume_on_vios(
                         vios_w, self.volume_id)
 
+                    # If we have a device name, but not a udid, at this point
+                    # we should not continue.  The hdisk is in a bad state
+                    # in the I/O Server.  Subsequent scrub code on future
+                    # deploys will clean this up.
+                    if not hdisk.good_discovery(status, device_name):
+                        LOG.warn(_LW(
+                            "Disconnect Volume: The backing hdisk for volume "
+                            "%(volume_id)s on Virtual I/O Server %(vios)s is "
+                            "not in a valid state.  No disconnect "
+                            "actions to be taken as volume is not healthy."),
+                            {'volume_id': self.volume_id, 'vios': vios_w.name})
+                        return False
+
                 if udid and not device_name:
                     device_name = vios_w.hdisk_from_uuid(udid)