[NetApp] Fix CIFS promote back issue

This change fixes the NetApp promote back issue when using CIFS
protocol. When promoting a replica, the NetApp ONTAP driver
attempts to create a new CIFS share entity (an access point as
defined in [1]) for the new active replica. This behavior
causes a failure since the storage identifies that a current
backend CIFS share with the same name exists, considering
that the reffered replica was once the active one.

This issue is addressed by removing the related CIFS share
entity when the replica gets promoted.

[1] https://library.netapp.com/ecmdocs/ECMP1401220/html/GUID-1898D717-A510-4B3D-B2E3-CCDDD5BD0089.html

Closes-Bug: #1879368
Change-Id: Id9bdd5df0ff05ea08881dd2c83397f0a367d9945

manila/share/drivers/netapp/dataontap/cluster_mode/lib_base.py

@@ -1960,9 +1960,29 @@ class NetAppCmodeFileStorageLibrary(object):
                                                      replica_list)
                 new_replica_list.append(r)
 
-        # Unmount the original active replica.
         orig_active_vserver = dm_session.get_vserver_from_share(
             orig_active_replica)
+
+        # Cleanup the original active share if necessary
+        orig_active_replica_backend = (
+            share_utils.extract_host(orig_active_replica['host'],
+                                     level='backend_name'))
+        orig_active_replica_name = self._get_backend_share_name(
+            orig_active_replica['id'])
+        orig_active_vserver_client = data_motion.get_client_for_backend(
+            orig_active_replica_backend, vserver_name=orig_active_vserver)
+
+        orig_active_replica_helper = self._get_helper(orig_active_replica)
+        orig_active_replica_helper.set_client(orig_active_vserver_client)
+
+        try:
+            orig_active_replica_helper.cleanup_demoted_replica(
+                orig_active_replica, orig_active_replica_name)
+        except exception.StorageCommunicationException:
+            LOG.exception("Could not cleanup the original active replica %s.",
+                          orig_active_replica['id'])
+
+        # Unmount the original active replica.
         self._unmount_orig_active_replica(orig_active_replica,
                                           orig_active_vserver)
 

manila/share/drivers/netapp/dataontap/protocols/base.py

@@ -71,3 +71,7 @@ class NetAppBaseHelper(object):
     @abc.abstractmethod
     def get_share_name_for_share(self, share):
         """Returns the flexvol name that hosts a share."""
+
+    @abc.abstractmethod
+    def cleanup_demoted_replica(self, share, share_name):
+        """Do some cleanup regarding the former active replica"""

manila/share/drivers/netapp/dataontap/protocols/cifs_cmode.py

@@ -163,3 +163,13 @@ class NetAppCmodeCIFSHelper(base.NetAppBaseHelper):
             return match.group('host_ip'), match.group('share_name')
         else:
             return '', ''
+
+    @na_utils.trace
+    def cleanup_demoted_replica(self, share, share_name):
+        """Cleans up some things regarding a demoted replica."""
+        # NOTE(carloss): This is necessary due to bug 1879368. If we do not
+        # remove this CIFS share, in case the demoted replica is promoted
+        # back, the promotion will fail due to a duplicated entry for the
+        # share, since a create share request is sent to the backend every
+        # time a promotion occurs.
+        self._client.remove_cifs_share(share_name)

manila/share/drivers/netapp/dataontap/protocols/nfs_cmode.py

@@ -182,3 +182,7 @@ class NetAppCmodeNFSHelper(base.NetAppBaseHelper):
         else:
             self._client.rename_nfs_export_policy(actual_export_policy,
                                                   expected_export_policy)
+
+    @na_utils.trace
+    def cleanup_demoted_replica(self, share, share_name):
+        return

manila/tests/share/drivers/netapp/dataontap/cluster_mode/test_lib_base.py

@@ -3513,9 +3513,10 @@ class NetAppFileStorageLibraryTestCase(test.TestCase):
                          '_get_vserver',
                          mock.Mock(return_value=(fake.VSERVER1,
                                                  mock.Mock())))
+        protocol_helper = mock.Mock()
         self.mock_object(self.library,
                          '_get_helper',
-                         mock.Mock(return_value=mock.Mock()))
+                         mock.Mock(return_value=protocol_helper))
         self.mock_object(self.library, '_create_export',
                          mock.Mock(return_value='fake_export_location'))
         self.mock_object(self.library, '_unmount_orig_active_replica')
@@ -3526,6 +3527,7 @@ class NetAppFileStorageLibraryTestCase(test.TestCase):
                          mock.Mock(return_value=mock_dm_session))
         self.mock_object(mock_dm_session, 'get_vserver_from_share',
                          mock.Mock(return_value=fake.VSERVER1))
+        self.mock_object(self.client, 'cleanup_demoted_replica')
 
         replicas = self.library.promote_replica(
             None, [self.fake_replica, self.fake_replica_2],
@@ -3551,6 +3553,44 @@ class NetAppFileStorageLibraryTestCase(test.TestCase):
         self.library._unmount_orig_active_replica.assert_called_once_with(
             self.fake_replica, fake.VSERVER1)
         self.library._handle_qos_on_replication_change.assert_called_once()
+        protocol_helper.cleanup_demoted_replica.assert_called_once_with(
+            self.fake_replica, fake.SHARE['name'])
+
+    def test_promote_replica_cleanup_demoted_storage_error(self):
+        self.mock_object(self.library,
+                         '_get_vserver',
+                         mock.Mock(return_value=(fake.VSERVER1,
+                                                 mock.Mock())))
+        protocol_helper = mock.Mock()
+        self.mock_object(self.library,
+                         '_get_helper',
+                         mock.Mock(return_value=protocol_helper))
+        self.mock_object(self.library, '_create_export',
+                         mock.Mock(return_value='fake_export_location'))
+        self.mock_object(self.library, '_unmount_orig_active_replica')
+        self.mock_object(self.library, '_handle_qos_on_replication_change')
+
+        mock_dm_session = mock.Mock()
+        self.mock_object(data_motion, "DataMotionSession",
+                         mock.Mock(return_value=mock_dm_session))
+        self.mock_object(mock_dm_session, 'get_vserver_from_share',
+                         mock.Mock(return_value=fake.VSERVER1))
+        self.mock_object(
+            protocol_helper, 'cleanup_demoted_replica',
+            mock.Mock(side_effect=exception.StorageCommunicationException))
+        mock_log = self.mock_object(lib_base.LOG, 'exception')
+
+        self.library.promote_replica(
+            None, [self.fake_replica, self.fake_replica_2],
+            self.fake_replica_2, [], share_server=None)
+
+        mock_dm_session.change_snapmirror_source.assert_called_once_with(
+            self.fake_replica, self.fake_replica, self.fake_replica_2,
+            mock.ANY
+        )
+        protocol_helper.cleanup_demoted_replica.assert_called_once_with(
+            self.fake_replica, fake.SHARE['name'])
+        mock_log.assert_called_once()
 
     def test_promote_replica_destination_unreachable(self):
         self.mock_object(self.library,

manila/tests/share/drivers/netapp/dataontap/protocols/test_cifs_cmode.py

@@ -214,3 +214,9 @@ class NetAppClusteredCIFSHelperTestCase(test.TestCase):
 
         self.assertEqual(ip, result_ip)
         self.assertEqual(share_name, result_share_name)
+
+    def test_cleanup_demoted_replica(self):
+        self.helper.cleanup_demoted_replica(fake.CIFS_SHARE, fake.SHARE_NAME)
+
+        self.mock_client.remove_cifs_share.assert_called_once_with(
+            fake.SHARE_NAME)

releasenotes/notes/bug-1879368-netapp-fix-cifs-promote-back-issue-d8fe28466f9dde49.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    Fixed an issue while promoting back share replicas created using CIFS
+    protocol. Please refer to the
+    `Launchpad bug #1879368 <https://bugs.launchpad.net/manila/+bug/1879368>`_
+    for more details.