Merge "iSCSI detect multipath DM with no WWN" into stable/train

os_brick/initiator/connectors/iscsi.py

@@ -738,10 +738,10 @@ class ISCSIConnector(base.BaseLinuxConnector, base_iscsi.BaseISCSIConnector):
             # We have devices but we don't know the wwn yet
             if not wwn and found:
                 wwn = self._linuxscsi.get_sysfs_wwn(found)
-            # We have the wwn but not a multipath
-            if wwn and not mpath:
+            if not mpath and found:
                 mpath = self._linuxscsi.find_sysfs_multipath_dm(found)
-                if not (mpath or wwn_added):
+                # We have the wwn but not a multipath
+                if wwn and not(mpath or wwn_added):
                     # Tell multipathd that this wwn is a multipath and hint
                     # multipathd to recheck all the devices we have just
                     # connected.  We only do this once, since for any new

os_brick/tests/initiator/connectors/test_iscsi.py

@@ -1211,6 +1211,42 @@ Setting up iSCSI targets: unused
         self.assertGreaterEqual(find_dm_mock.call_count, 2)
         self.assertEqual(4, connect_mock.call_count)
 
+    @mock.patch.object(linuxscsi.LinuxSCSI, 'find_sysfs_multipath_dm',
+                       side_effect=[None, 'dm-0'])
+    @mock.patch.object(linuxscsi.LinuxSCSI, 'get_sysfs_wwn', return_value='')
+    @mock.patch.object(linuxscsi.LinuxSCSI, 'multipath_add_path')
+    @mock.patch.object(linuxscsi.LinuxSCSI, 'multipath_add_wwid')
+    @mock.patch.object(iscsi.ISCSIConnector, '_connect_vol')
+    @mock.patch('time.sleep')
+    def test_connect_multipath_volume_no_wwid(self, sleep_mock, connect_mock,
+                                              add_wwid_mock, add_path_mock,
+                                              get_wwn_mock, find_dm_mock):
+        # Even if we don't have the wwn we'll be able to find the multipath
+        def my_connect(rescans, props, data):
+            devs = {'tgt1': 'sda', 'tgt2': 'sdb', 'tgt3': 'sdc', 'tgt4': 'sdd'}
+            data['stopped_threads'] += 1
+            data['num_logins'] += 1
+            dev = devs[props['target_iqn']]
+            data['found_devices'].append(dev)
+            data['just_added_devices'].append(dev)
+
+        connect_mock.side_effect = my_connect
+
+        res = self.connector._connect_multipath_volume(self.CON_PROPS)
+
+        expected = {'type': 'block', 'scsi_wwn': '', 'multipath_id': '',
+                    'path': '/dev/dm-0'}
+        self.assertEqual(expected, res)
+
+        self.assertGreaterEqual(get_wwn_mock.call_count, 2)
+        result = list(get_wwn_mock.call_args[0][0])
+        result.sort()
+        self.assertEqual(['sda', 'sdb', 'sdc', 'sdd'], result)
+        add_wwid_mock.assert_not_called()
+        add_path_mock.assert_not_called()
+        self.assertGreaterEqual(find_dm_mock.call_count, 2)
+        self.assertEqual(4, connect_mock.call_count)
+
     @mock.patch.object(linuxscsi.LinuxSCSI, 'find_sysfs_multipath_dm',
                        side_effect=[None, 'dm-0'])
     @mock.patch.object(linuxscsi.LinuxSCSI, 'get_sysfs_wwn',

releasenotes/notes/improve-iscsi-multipath-detection-f36f28a993f61936.yaml

@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Improve iSCSI multipath detection to work even if we cannot find the
+    volume's WWN in sysfs.
+    (bug 1881619).