Merge "RBD: Improve IOWrapper's close & flush methods"

os_brick/initiator/linuxrbd.py

@@ -226,6 +226,8 @@ class RBDVolumeIOWrapper(io.RawIOBase):
         return self._offset
 
     def flush(self):
+        # Raise ValueError if already closed
+        super().flush()
         try:
             self._rbd_volume.image.flush()
         except AttributeError:
@@ -240,4 +242,8 @@ class RBDVolumeIOWrapper(io.RawIOBase):
         raise IOError(_("fileno() not supported by RBD()"))
 
     def close(self):
-        self.rbd_image.close()
+        if not self.closed:
+            # Can't set closed attribute ourselves, call parent to flush and
+            # change it.
+            super().close()
+            self.rbd_image.close()

os_brick/tests/initiator/test_linuxrbd.py

@@ -194,6 +194,14 @@ class RBDVolumeIOWrapperTestCase(base.TestCase):
             self.assertEqual(1, self.mock_volume.image.flush.call_count)
             self.assertEqual(1, mock_logger.warning.call_count)
 
+    def test_flush_on_closed(self):
+        self.mock_volume_wrapper.close()
+        self.mock_volume.image.flush.assert_called_once_with()
+        self.assertTrue(self.mock_volume_wrapper.closed)
+        self.mock_volume.image.flush.reset_mock()
+        self.assertRaises(ValueError, self.mock_volume_wrapper.flush)
+        self.mock_volume.image.flush.assert_not_called()
+
     def test_fileno(self):
         self.assertRaises(IOError, self.mock_volume_wrapper.fileno)
 
@@ -207,6 +215,12 @@ class RBDVolumeIOWrapperTestCase(base.TestCase):
             linuxrbd.RBDImageMetadata(rbd_volume, 'pool', 'user', None))
         rbd_handle.close()
         self.assertEqual(1, rbd_disconnect.call_count)
+        # Confirm the handle now reports that is closed (this attribute cannot
+        # be modified directly)
+        self.assertTrue(rbd_handle.closed)
+        # New call to close shouldn't create additional calls
+        rbd_handle.close()
+        self.assertEqual(1, rbd_disconnect.call_count)
 
 
 class RBDVolumeTestCase(base.TestCase):