Merge "SMBFS: allow snapshot ro attach"

cinder/tests/unit/windows/test_smbfs.py

@@ -178,6 +178,35 @@ class WindowsSmbFsTestCase(test.TestCase):
 
         self.assertEqual(expected, ret_val)
 
+    @mock.patch.object(smbfs.WindowsSmbfsDriver, '_get_snapshot_backing_file')
+    @mock.patch.object(smbfs.WindowsSmbfsDriver, 'get_volume_format')
+    @mock.patch.object(smbfs.WindowsSmbfsDriver, '_get_mount_point_base')
+    def test_initialize_connection_snapshot(self, mock_get_mount_base,
+                                            mock_get_volume_format,
+                                            mock_get_snap_by_backing_file):
+        self._smbfs_driver.shares = {self._FAKE_SHARE: self._FAKE_SHARE_OPTS}
+        mock_get_snap_by_backing_file.return_value = self._FAKE_VOLUME_NAME
+        mock_get_volume_format.return_value = 'vhdx'
+        mock_get_mount_base.return_value = self._FAKE_MNT_BASE
+
+        exp_data = {'export': self._FAKE_SHARE,
+                    'format': 'vhdx',
+                    'name': self._FAKE_VOLUME_NAME,
+                    'options': self._FAKE_SHARE_OPTS,
+                    'access_mode': 'ro'}
+        expected = {
+            'driver_volume_type': 'smbfs',
+            'data': exp_data,
+            'mount_point_base': self._FAKE_MNT_BASE}
+        ret_val = self._smbfs_driver.initialize_connection_snapshot(
+            self.snapshot, mock.sentinel.connector)
+
+        self.assertEqual(expected, ret_val)
+
+        mock_get_snap_by_backing_file.assert_called_once_with(self.snapshot)
+        mock_get_volume_format.assert_called_once_with(self.snapshot.volume)
+        mock_get_mount_base.assert_called_once_with()
+
     def test_setup(self):
         self._test_setup(config=self._FAKE_SMBFS_CONFIG)
 

cinder/volume/drivers/windows/smbfs.py

@@ -194,6 +194,25 @@ class WindowsSmbfsDriver(remotefs_drv.RevertToSnapshotMixin,
             'mount_point_base': self._get_mount_point_base()
         }
 
+    @coordination.synchronized('{self.driver_prefix}-{snapshot.volume.id}')
+    def initialize_connection_snapshot(self, snapshot, connector):
+        backing_file = self._get_snapshot_backing_file(snapshot)
+        volume = snapshot.volume
+        fmt = self.get_volume_format(volume)
+
+        data = {'export': volume.provider_location,
+                'format': fmt,
+                'name': backing_file,
+                'access_mode': 'ro'}
+
+        if volume.provider_location in self.shares:
+            data['options'] = self.shares[volume.provider_location]
+        return {
+            'driver_volume_type': self.driver_volume_type,
+            'data': data,
+            'mount_point_base': self._get_mount_point_base()
+        }
+
     def _check_os_platform(self):
         if sys.platform != 'win32':
             _msg = _("This system platform (%s) is not supported. This "

releasenotes/notes/smbfs-snapshot-attach-14742fe8f5864ac6.yaml

@@ -0,0 +1,6 @@
+---
+features:
+  - |
+    The SMBFS driver now supports the 'snapshot attach' feature. Special care
+    must be taken when attaching snapshots though, as writing to a snapshot
+    will corrupt the differencing image chain.