Storwize/SVC: fix attach bug for live migration.

Add force flag for mkvdiskhostmap command to allow multi host mapping

Change-Id: I290a5986b213a0aaeae0d0ea0ad57350c9dee3c9
Fixes: bug #1179773

cinder/tests/test_storwize_svc.py

@@ -884,9 +884,17 @@ def _cmd_mkvdiskhostmap(self, **kwargs):
                     (v['lun'] == mapping_info['lun'])):
                 return self._errors['CMMVC5879E']
 
-        self._mappings_list[mapping_info['vol']] = mapping_info
-        return ('Virtual Disk to Host map, id [%s], successfully created'
-                % (mapping_info['id']), '')
+        if kwargs.get('host', '').startswith('duplicate_mapping'):
+            if 'force' in kwargs:
+                self._mappings_list[mapping_info['vol']] = mapping_info
+                return ('Virtual Disk to Host map, id [%s], '
+                        'successfully created' % (mapping_info['id']), '')
+            else:
+                return self._errors['CMMVC6071E']
+        else:
+            self._mappings_list[mapping_info['vol']] = mapping_info
+            return ('Virtual Disk to Host map, id [%s], successfully created'
+                    % (mapping_info['id']), '')
 
     # Delete a vdisk-host mapping
     def _cmd_rmvdiskhostmap(self, **kwargs):
@@ -1777,6 +1785,37 @@ def test_storwize_svc_host_maps(self):
         ret = self.driver._get_host_from_connector(conn)
         self.assertEqual(ret, None)
 
+    def test_storwize_svc_multi_host_maps(self):
+        # Create a volume to be used in mappings
+        ctxt = context.get_admin_context()
+        volume = self._generate_vol_info(None, None)
+        self.driver.create_volume(volume)
+
+        # Create volume types that we created
+        types = {}
+        for protocol in ['FC', 'iSCSI']:
+            opts = {'storage_protocol': '<in> ' + protocol}
+            types[protocol] = volume_types.create(ctxt, protocol, opts)
+
+        conn = {'initiator': self._iscsi_name,
+                'ip': '11.11.11.11',
+                'host': 'duplicate_mapping'}
+
+        for protocol in ['FC', 'iSCSI']:
+            volume['volume_type_id'] = types[protocol]['id']
+
+            # Make sure that the volumes have been created
+            self._assert_vol_exists(volume['name'], True)
+
+            self.driver.initialize_connection(volume, conn)
+            self.driver.terminate_connection(volume, conn)
+
+            self._set_flag('storwize_svc_multihostmap_enabled', False)
+            self.assertRaises(exception.CinderException,
+                              self.driver.initialize_connection, volume, conn)
+            self.driver.terminate_connection(volume, conn)
+            self._reset_flags()
+
     def test_storwize_svc_delete_volume_snapshots(self):
         # Create a volume with two snapshots
         master = self._generate_vol_info(None, None)

cinder/volume/drivers/storwize_svc.py

@@ -95,6 +95,9 @@
     cfg.BoolOpt('storwize_svc_multipath_enabled',
                 default=False,
                 help='Connect with multipath (currently FC-only)'),
+    cfg.BoolOpt('storwize_svc_multihostmap_enabled',
+                default=True,
+                help='Allows vdisk to multi host mapping'),
 ]
 
 
@@ -600,10 +603,25 @@ def _map_vol_to_host(self, volume_name, host_name):
                        {'host_name': host_name,
                         'result_lun': result_lun,
                         'volume_name': volume_name})
-            out, err = self._run_ssh(ssh_cmd)
-            self._assert_ssh_return('successfully created' in out,
-                                    '_map_vol_to_host', ssh_cmd, out, err)
-
+            out, err = self._run_ssh(ssh_cmd, check_exit_code=False)
+            if err and err.startswith('CMMVC6071E'):
+                if not self.configuration.storwize_svc_multihostmap_enabled:
+                    LOG.error(_('storwize_svc_multihostmap_enabled is set '
+                                'to Flase, Not allow multi host mapping'))
+                    exception_msg = 'CMMVC6071E The VDisk-to-host mapping '\
+                                    'was not created because the VDisk is '\
+                                    'already mapped to a host.\n"'
+                    raise exception.CinderException(data=exception_msg)
+                ssh_cmd = ssh_cmd.replace('mkvdiskhostmap',
+                                          'mkvdiskhostmap -force')
+                # try to map one volume to multiple hosts
+                out, err = self._run_ssh(ssh_cmd)
+                LOG.warn(_('volume %s mapping to multi host') % volume_name)
+                self._assert_ssh_return('successfully created' in out,
+                                        '_map_vol_to_host', ssh_cmd, out, err)
+            else:
+                self._assert_ssh_return('successfully created' in out,
+                                        '_map_vol_to_host', ssh_cmd, out, err)
         LOG.debug(_('leave: _map_vol_to_host: LUN %(result_lun)s, volume '
                     '%(volume_name)s, host %(host_name)s') %
                   {'result_lun': result_lun,