Disallow extension of attached volumes for NFS & Quobyte drivers

NFS and Quobyte drivers no longer allow extension of an attached
volume. The extend operation raises an ExtendVolumeError
in the Cinder Volume service in case the volume to be extended
is currently attached.

This should be reverted once a a more capable solution for
bug #1870367 has been found.

Partial-bug: #1870367

Change-Id: Ib2a7c1cdf269b4907ff8adff1b9d900072eedde2

cinder/tests/unit/volume/drivers/test_nfs.py

@@ -997,6 +997,28 @@ class NfsDriverTestCase(test.TestCase):
                         resize.assert_called_once_with(path, newSize,
                                                        run_as_root=True)
 
+    def test_extend_volume_attached_fail(self):
+        """Extend a volume by 1."""
+        self._set_driver()
+        drv = self._driver
+        volume = fake_volume.fake_volume_obj(
+            self.context,
+            id='80ee16b6-75d2-4d54-9539-ffc1b4b0fb10',
+            size=1,
+            provider_location='nfs_share')
+        path = 'path'
+        newSize = volume['size'] + 1
+
+        with mock.patch.object(drv, 'local_path', return_value=path):
+            with mock.patch.object(drv, '_is_share_eligible',
+                                   return_value=True):
+                with mock.patch.object(drv, '_is_file_size_equal',
+                                       return_value=True):
+                    with mock.patch.object(drv, '_is_volume_attached',
+                                           return_value=True):
+                        self.assertRaises(exception.ExtendVolumeError,
+                                          drv.extend_volume, volume, newSize)
+
     def test_extend_volume_failure(self):
         """Error during extend operation."""
         self._set_driver()

cinder/tests/unit/volume/drivers/test_quobyte.py

@@ -927,7 +927,10 @@ class QuobyteDriverTestCase(test.TestCase):
         drv._ensure_share_mounted.assert_not_called()
         drv._execute.assert_not_called()
 
-    def test_extend_volume(self):
+    @ddt.data(True, False)
+    @mock.patch.object(remotefs.RemoteFSSnapDriverDistributed,
+                       "_is_volume_attached")
+    def test_extend_volume(self, is_attached, mock_remote_attached):
         drv = self._driver
 
         volume = self._simple_volume()
@@ -948,12 +951,19 @@ class QuobyteDriverTestCase(test.TestCase):
         image_utils.qemu_img_info = mock.Mock(return_value=img_info)
         image_utils.resize_image = mock.Mock()
 
-        drv.extend_volume(volume, 3)
+        mock_remote_attached.return_value = is_attached
 
-        image_utils.qemu_img_info.assert_called_once_with(volume_path,
-                                                          force_share=True,
-                                                          run_as_root=False)
-        image_utils.resize_image.assert_called_once_with(volume_path, 3)
+        if is_attached:
+            self.assertRaises(exception.ExtendVolumeError, drv.extend_volume,
+                              volume, 3)
+        else:
+            drv.extend_volume(volume, 3)
+
+            image_utils.qemu_img_info.assert_called_once_with(volume_path,
+                                                              force_share=True,
+                                                              run_as_root=False
+                                                              )
+            image_utils.resize_image.assert_called_once_with(volume_path, 3)
 
     def test_copy_volume_from_snapshot(self):
         drv = self._driver

cinder/volume/drivers/nfs.py

@@ -363,6 +363,12 @@ class NfsDriver(remotefs.RemoteFSSnapDriverDistributed):
 
     def extend_volume(self, volume, new_size):
         """Extend an existing volume to the new size."""
+        if self._is_volume_attached(volume):
+            # NOTE(kaisers): no attached extensions until #1870367 is fixed
+            msg = (_("Cannot extend volume %s while it is attached.")
+                   % volume['id'])
+            raise exception.ExtendVolumeError(msg)
+
         LOG.info('Extending volume %s.', volume.id)
         extend_by = int(new_size) - volume.size
         if not self._is_share_eligible(volume.provider_location,

cinder/volume/drivers/quobyte.py

@@ -540,6 +540,12 @@ class QuobyteDriver(remotefs_drv.RemoteFSSnapDriverDistributed):
 
     @utils.synchronized('quobyte', external=False)
     def extend_volume(self, volume, size_gb):
+        if self._is_volume_attached(volume):
+            # NOTE(kaisers): no attached extensions until #1870367 is fixed
+            msg = (_("Cannot extend volume %s while it is attached.")
+                   % volume['id'])
+            raise exception.ExtendVolumeError(msg)
+
         volume_path = self.local_path(volume)
 
         info = self._qemu_img_info(volume_path, volume.name)

doc/source/reference/support-matrix.ini

@@ -298,12 +298,12 @@ driver.nec=complete
 driver.netapp_ontap=missing
 driver.netapp_solidfire=complete
 driver.nexenta=complete
-driver.nfs=complete
+driver.nfs=missing
 driver.nimble=complete
 driver.prophetstor=complete
 driver.pure=complete
 driver.qnap=complete
-driver.quobyte=complete
+driver.quobyte=missing
 driver.rbd=complete
 driver.sandstone=complete
 driver.seagate=complete

releasenotes/notes/bug_1870367-49b74d10a9bfcf07.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    `Bug #1870367 <https://bugs.launchpad.net/cinder/+bug/1870367>`_ :
+    Partially fixed NFS and Quobyte drivers by no longer allowing extending a
+    volume while it is attached, to prevent failures due to Qemu internal
+    locking mechanisms.