Check path alive before get scsi wwn

In FC environment, when disconnect volume,
if the first path in the loop is failed,
it will lead get scsi wwn to failure.
So I think we need to add path validity check
before get scsi wwn

Change-Id: I9d3a9dac13dcd585330e7b891c61b2626e5aabec
Closes-Bug: 1831621

os_brick/initiator/connectors/fibre_channel.py

@@ -333,7 +333,8 @@ class FibreChannelConnector(base.BaseLinuxConnector):
         mpath_path = None
         for path in volume_paths:
             real_path = self._linuxscsi.get_name_from_path(path)
-            if self.use_multipath and not mpath_path:
+            if (self.use_multipath and not mpath_path
+                    and self.check_valid_device(path)):
                 wwn = self._linuxscsi.get_scsi_wwn(path)
                 mpath_path = self._linuxscsi.find_multipath_device_path(wwn)
                 if mpath_path:

os_brick/tests/initiator/connectors/test_fibre_channel.py

@@ -664,3 +664,65 @@ class FibreChannelConnectorTestCase(test_connector.ConnectorTestCase):
                                            was_multipath)
         remove_mock.assert_called_once_with('/dev/sda',
                                             flush=flush_mock.return_value)
+
+    @mock.patch.object(linuxscsi.LinuxSCSI, 'find_multipath_device')
+    @mock.patch.object(linuxscsi.LinuxSCSI, 'wait_for_rw')
+    @mock.patch.object(os.path, 'exists', return_value=True)
+    @mock.patch.object(os.path, 'realpath', return_value='/dev/sdb')
+    @mock.patch.object(linuxfc.LinuxFibreChannel, 'get_fc_hbas')
+    @mock.patch.object(linuxfc.LinuxFibreChannel, 'get_fc_hbas_info')
+    @mock.patch.object(linuxscsi.LinuxSCSI, 'get_scsi_wwn')
+    @mock.patch.object(linuxscsi.LinuxSCSI, 'get_device_info')
+    @mock.patch.object(linuxscsi.LinuxSCSI, 'find_multipath_device_path')
+    @mock.patch.object(base.BaseLinuxConnector, 'check_valid_device')
+    def test_disconnect_volume(self, check_valid_device_mock,
+                               find_mp_device_path_mock,
+                               get_device_info_mock,
+                               get_scsi_wwn_mock,
+                               get_fc_hbas_info_mock,
+                               get_fc_hbas_mock,
+                               realpath_mock,
+                               exists_mock,
+                               wait_for_rw_mock,
+                               find_mp_dev_mock):
+
+        check_valid_device_mock.return_value = True
+        self.connector.use_multipath = True
+        get_fc_hbas_mock.side_effect = self.fake_get_fc_hbas
+        get_fc_hbas_info_mock.side_effect = self.fake_get_fc_hbas_info
+
+        wwn = '1234567890'
+        multipath_devname = '/dev/md-1'
+        devices = {"device": multipath_devname,
+                   "id": wwn,
+                   "devices": [{'device': '/dev/sdb',
+                                'address': '1:0:0:1',
+                                'host': 1, 'channel': 0,
+                                'id': 0, 'lun': 1},
+                               {'device': '/dev/sdc',
+                                'address': '1:0:0:2',
+                                'host': 1, 'channel': 0,
+                                'id': 0, 'lun': 1}]}
+        get_device_info_mock.side_effect = devices['devices']
+        get_scsi_wwn_mock.return_value = wwn
+
+        location = '10.0.2.15:3260'
+        name = 'volume-00000001'
+        vol = {'id': 1, 'name': name}
+        initiator_wwn = ['1234567890123456', '1234567890123457']
+
+        find_mp_device_path_mock.return_value = '/dev/mapper/mpatha'
+        find_mp_dev_mock.return_value = {"device": "dm-3",
+                                         "id": wwn,
+                                         "name": "mpatha"}
+
+        connection_info = self.fibrechan_connection(vol, location,
+                                                    initiator_wwn)
+        self.connector.disconnect_volume(connection_info['data'],
+                                         devices['devices'][0])
+        expected_commands = [
+            'multipath -f ' + find_mp_device_path_mock.return_value,
+            'tee -a /sys/block/sdb/device/delete',
+            'tee -a /sys/block/sdc/device/delete',
+        ]
+        self.assertEqual(expected_commands, self.cmds)