Implement update_migrated_volume for NFS driver

After the migration of an available volume to an NFS driver,
the back-end name can be renamed back to its original volume id
or name.

Change-Id: I2ef339f3a67088587199a1da825ec67529a9ec57
Closes-Bug: #1499151

diff --git a/cinder/tests/unit/test_nfs.py b/cinder/tests/unit/test_nfs.py
index 4432c7b1bb73c146a8ac8b17c56fd74b4c0550b2..6af7f772f426670c6b4ce826381f5186959ded69 100644 (file)
--- a/cinder/tests/unit/test_nfs.py
+++ b/cinder/tests/unit/test_nfs.py
@@ -1317,20 +1317,67 @@ class NfsDriverDoSetupTestCase(test.TestCase):
                        check_exit_code=False,
                        run_as_root=False)])
 
-    def test_update_migrated_volume_is_there(self):
-        """Ensure that driver.update_migrated_volume() is there."""
+    @mock.patch.object(os, 'rename')
+    def test_update_migrated_available_volume(self, rename_volume):
+        self._test_update_migrated_volume('available', rename_volume)
 
-        drv = nfs.NfsDriver(configuration=self.configuration)
+    @mock.patch.object(os, 'rename')
+    def test_update_migrated_available_volume_rename_fail(self, rename_volume):
+        self._test_update_migrated_volume('available', rename_volume,
+                                          rename_exception=True)
 
-        v1 = DumbVolume()
-        v2 = DumbVolume()
-
-        self.assertRaises(NotImplementedError,
-                          drv.update_migrated_volume,
-                          self.context,
-                          v1,
-                          v2,
-                          mock.sentinel)
+    @mock.patch.object(os, 'rename')
+    def test_update_migrated_in_use_volume(self, rename_volume):
+        self._test_update_migrated_volume('in-use', rename_volume)
+
+    def _test_update_migrated_volume(self, volume_status, rename_volume,
+                                     rename_exception=False):
+        drv = nfs.NfsDriver(configuration=self.configuration)
+        fake_volume_id = 'vol1'
+        fake_new_volume_id = 'vol2'
+        fake_provider_source = 'fake_provider_source'
+        fake_provider = 'fake_provider'
+        base_dir = '/dir_base/'
+        volume_name_template = 'volume-%s'
+        original_volume_name = volume_name_template % fake_volume_id
+        current_name = volume_name_template % fake_new_volume_id
+        original_volume_path = base_dir + original_volume_name
+        current_path = base_dir + current_name
+        fake_volume = {'size': 1, 'id': fake_volume_id,
+                       'provider_location': fake_provider_source,
+                       '_name_id': None}
+        fake_new_volume = {'size': 1, 'id': fake_new_volume_id,
+                           'provider_location': fake_provider,
+                           '_name_id': None}
+
+        with mock.patch.object(drv, 'local_path') as local_path:
+            local_path.return_value = base_dir + current_name
+            if volume_status == 'in-use':
+                update = drv.update_migrated_volume(self.context,
+                                                    fake_volume,
+                                                    fake_new_volume,
+                                                    volume_status)
+                self.assertEqual({'_name_id': fake_new_volume_id,
+                                  'provider_location': fake_provider}, update)
+            elif rename_exception:
+                rename_volume.side_effect = OSError
+                update = drv.update_migrated_volume(self.context,
+                                                    fake_volume,
+                                                    fake_new_volume,
+                                                    volume_status)
+                rename_volume.assert_called_once_with(current_path,
+                                                      original_volume_path)
+                self.assertEqual({'_name_id': fake_new_volume_id,
+                                  'provider_location': fake_provider}, update)
+            else:
+                update = drv.update_migrated_volume(self.context,
+                                                    fake_volume,
+                                                    fake_new_volume,
+                                                    volume_status)
+                rename_volume.assert_called_once_with(current_path,
+                                                      original_volume_path)
+                self.assertEqual({'_name_id': None,
+                                  'provider_location': fake_provider}, update)
 
     def test_retype_is_there(self):
         "Ensure that driver.retype() is there."""

diff --git a/cinder/volume/drivers/nfs.py b/cinder/volume/drivers/nfs.py
index bda7f6a62deb0bbc14be069a5fa8f2ef6d2bab91..9aea7337f921107eee87003a5e8ad8e4039dd4e9 100644 (file)
--- a/cinder/volume/drivers/nfs.py
+++ b/cinder/volume/drivers/nfs.py
@@ -378,6 +378,45 @@ class NfsDriver(driver.ExtendVD, remotefs.RemoteFSDriver):
                             "for information on a secure NAS configuration."),
                         doc_html)
 
+    def update_migrated_volume(self, ctxt, volume, new_volume,
+                               original_volume_status):
+        """Return the keys and values updated from NFS for migrated volume.
+
+        This method should rename the back-end volume name(id) on the
+        destination host back to its original name(id) on the source host.
+
+        :param ctxt: The context used to run the method update_migrated_volume
+        :param volume: The original volume that was migrated to this backend
+        :param new_volume: The migration volume object that was created on
+                           this backend as part of the migration process
+        :param original_volume_status: The status of the original volume
+        :return model_update to update DB with any needed changes
+        """
+        # TODO(vhou) This method may need to be updated after
+        # NFS snapshots are introduced.
+        name_id = None
+        if original_volume_status == 'available':
+            current_name = CONF.volume_name_template % new_volume['id']
+            original_volume_name = CONF.volume_name_template % volume['id']
+            current_path = self.local_path(new_volume)
+            # Replace the volume name with the original volume name
+            original_path = current_path.replace(current_name,
+                                                 original_volume_name)
+            try:
+                os.rename(current_path, original_path)
+            except OSError:
+                LOG.error(_LE('Unable to rename the logical volume '
+                              'for volume: %s'), volume['id'])
+                # If the rename fails, _name_id should be set to the new
+                # volume id and provider_location should be set to the
+                # one from the new volume as well.
+                name_id = new_volume['_name_id'] or new_volume['id']
+        else:
+            # The back-end will not be renamed.
+            name_id = new_volume['_name_id'] or new_volume['id']
+        return {'_name_id': name_id,
+                'provider_location': new_volume['provider_location']}
+
     def _update_volume_stats(self):
         """Retrieve stats info from volume group."""