Fixes multi-registry config in Quobyte driver

This closes a bug concerning multi-registry configurations
for Quobyte volumes due to no longer using the is_mounted()
method that failed in that case.
Besides, this adds exception handling for the unmount call that
is issued on trying to mount an already mounted volume.

NOTE: The original commit also added a new feature (fs type
based validation) which is omitted in this backport.

Closes-Bug: #1737131

Change-Id: Ia5a23ce1123a68608ee2ec6f2ac5dca02da67c59
(cherry picked from commit 05a73c0)

Author: casusbelli

nova/exception.py

@@ -354,6 +354,10 @@ class InvalidVolumeAccessMode(Invalid):
     msg_fmt = _("Invalid volume access mode: %(access_mode)s")
 
 
+class StaleVolumeMount(InvalidVolume):
+    msg_fmt = _("The volume mount at %(mount_path)s is unusable.")
+
+
 class InvalidMetadata(Invalid):
     msg_fmt = _("Invalid metadata: %(reason)s")
 

nova/tests/unit/virt/libvirt/volume/test_quobyte.py

@@ -293,13 +293,15 @@ class LibvirtQuobyteVolumeDriverTestCase(
         test_volume.LibvirtVolumeBaseTestCase):
     """Tests the LibvirtQuobyteVolumeDriver class."""
 
+    @mock.patch.object(quobyte, 'umount_volume')
     @mock.patch.object(quobyte, 'validate_volume')
     @mock.patch.object(quobyte, 'mount_volume')
     @mock.patch.object(libvirt_utils, 'is_mounted', return_value=False)
     def test_libvirt_quobyte_driver_mount(self,
                                           mock_is_mounted,
                                           mock_mount_volume,
-                                          mock_validate_volume
+                                          mock_validate_volume,
+                                          mock_umount_volume
                                           ):
         mnt_base = '/mnt'
         self.flags(quobyte_mount_point_base=mnt_base, group='libvirt')
@@ -313,6 +315,9 @@ def test_libvirt_quobyte_driver_mount(self,
 
         connection_info = {'data': {'export': export_string,
                                     'name': self.name}}
+        mock_validate_volume.side_effect = [nova_exception.StaleVolumeMount(
+            "This shall fail."), True, True]
+
         libvirt_driver.connect_volume(connection_info, mock.sentinel.instance)
 
         conf = libvirt_driver.get_config(connection_info, self.disk_info)
@@ -324,12 +329,12 @@ def test_libvirt_quobyte_driver_mount(self,
                                                   export_mnt_base,
                                                   mock.ANY)
         mock_validate_volume.assert_called_with(export_mnt_base)
+        mock_umount_volume.assert_called_once_with(
+            libvirt_driver._get_mount_path(connection_info))
 
-    @mock.patch.object(quobyte, 'validate_volume')
+    @mock.patch.object(quobyte, 'validate_volume', return_value=True)
     @mock.patch.object(quobyte, 'umount_volume')
-    @mock.patch.object(libvirt_utils, 'is_mounted', return_value=True)
-    def test_libvirt_quobyte_driver_umount(self, mock_is_mounted,
-                                           mock_umount_volume,
+    def test_libvirt_quobyte_driver_umount(self, mock_umount_volume,
                                            mock_validate_volume):
         mnt_base = '/mnt'
         self.flags(quobyte_mount_point_base=mnt_base, group='libvirt')
@@ -352,7 +357,9 @@ def test_libvirt_quobyte_driver_umount(self, mock_is_mounted,
         libvirt_driver.disconnect_volume(connection_info,
                                          mock.sentinel.instance)
 
-        mock_validate_volume.assert_called_once_with(export_mnt_base)
+        mock_validate_volume.assert_has_calls([mock.call(export_mnt_base),
+                                               mock.call(export_mnt_base),
+                                               mock.call(export_mnt_base)])
         mock_umount_volume.assert_called_once_with(export_mnt_base)
 
     @mock.patch.object(quobyte, 'validate_volume')
@@ -385,15 +392,14 @@ def test_libvirt_quobyte_driver_already_mounted(self,
                                          mock.sentinel.instance)
 
         mock_umount_volume.assert_called_once_with(export_mnt_base)
-        mock_validate_volume.assert_called_once_with(export_mnt_base)
+        mock_validate_volume.assert_has_calls([mock.call(export_mnt_base),
+                                               mock.call(export_mnt_base)])
 
+    @mock.patch.object(quobyte, 'umount_volume')
     @mock.patch.object(quobyte, 'validate_volume')
     @mock.patch.object(quobyte, 'mount_volume')
-    @mock.patch.object(libvirt_utils, 'is_mounted', return_value=False)
-    def test_libvirt_quobyte_driver_qcow2(self, mock_is_mounted,
-                                          mock_mount_volume,
-                                          mock_validate_volume
-                                          ):
+    def test_libvirt_quobyte_driver_qcow2(self, mock_mount_volume,
+                                          mock_validate_volume, mock_umount):
         mnt_base = '/mnt'
         self.flags(quobyte_mount_point_base=mnt_base, group='libvirt')
         libvirt_driver = quobyte.LibvirtQuobyteVolumeDriver(self.fake_host)
@@ -408,6 +414,8 @@ def test_libvirt_quobyte_driver_qcow2(self, mock_is_mounted,
 
         export_mnt_base = os.path.join(mnt_base,
                                        utils.get_hash_str(quobyte_volume))
+        mock_validate_volume.side_effect = [nova_exception.StaleVolumeMount(
+            "This shall fail."), True, True]
 
         libvirt_driver.connect_volume(connection_info, mock.sentinel.instance)
         conf = libvirt_driver.get_config(connection_info, self.disk_info)
@@ -423,6 +431,8 @@ def test_libvirt_quobyte_driver_qcow2(self, mock_is_mounted,
 
         libvirt_driver.disconnect_volume(connection_info,
                                          mock.sentinel.instance)
+        mock_umount.assert_has_calls([mock.call(export_mnt_base),
+                                      mock.call(export_mnt_base)])
 
     @mock.patch.object(libvirt_utils, 'is_mounted', return_value=True)
     def test_libvirt_quobyte_driver_mount_non_quobyte_volume(self,

nova/virt/libvirt/volume/quobyte.py

@@ -13,7 +13,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import errno
 import os
 
 from oslo_concurrency import processutils
@@ -26,7 +25,6 @@
 from nova import exception as nova_exception
 from nova.i18n import _
 from nova import utils
-from nova.virt.libvirt import utils as libvirt_utils
 from nova.virt.libvirt.volume import fs
 
 LOG = logging.getLogger(__name__)
@@ -75,7 +73,10 @@ def umount_volume(mnt_base):
 
 
 def validate_volume(mount_path):
-    """Runs a number of tests to be sure this is a (working) Quobyte mount"""
+    """Determine if the volume is a valid Quobyte mount.
+
+    Runs a number of tests to be sure this is a (working) Quobyte mount
+    """
     partitions = psutil.disk_partitions(all=True)
     for p in partitions:
         if mount_path != p.mountpoint:
@@ -90,10 +91,10 @@ def validate_volume(mount_path):
                 msg = (_("The mount %(mount_path)s is not a "
                          "valid Quobyte volume. Stale mount?")
                        % {'mount_path': mount_path})
-            raise nova_exception.InvalidVolume(msg)
+            raise nova_exception.StaleVolumeMount(msg, mount_path=mount_path)
         else:
-            msg = (_("The mount %(mount_path)s is not a valid"
-                     " Quobyte volume according to partition list.")
+            msg = (_("The mount %(mount_path)s is not a valid "
+                     "Quobyte volume according to partition list.")
                    % {'mount_path': mount_path})
             raise nova_exception.InvalidVolume(msg)
     msg = (_("No matching Quobyte mount entry for %(mount_path)s"
@@ -128,39 +129,40 @@ def connect_volume(self, connection_info, instance):
         data = connection_info['data']
         quobyte_volume = self._normalize_export(data['export'])
         mount_path = self._get_mount_path(connection_info)
-        mounted = libvirt_utils.is_mounted(mount_path,
-                                           SOURCE_PROTOCOL
-                                           + '@' + quobyte_volume)
-        if mounted:
-            try:
-                os.stat(mount_path)
-            except OSError as exc:
-                if exc.errno == errno.ENOTCONN:
-                    mounted = False
-                    LOG.info('Fixing previous mount %s which was not'
-                             ' unmounted correctly.', mount_path)
-                    umount_volume(mount_path)
+        try:
+            validate_volume(mount_path)
+            mounted = True
+        except nova_exception.StaleVolumeMount:
+            mounted = False
+            LOG.info('Fixing previous mount %s which was not '
+                     'unmounted correctly.', mount_path)
+            umount_volume(mount_path)
+        except nova_exception.InvalidVolume:
+            mounted = False
 
         if not mounted:
             mount_volume(quobyte_volume,
                          mount_path,
                          CONF.libvirt.quobyte_client_cfg)
 
-        validate_volume(mount_path)
+        try:
+            validate_volume(mount_path)
+        except (nova_exception.InvalidVolume,
+                nova_exception.StaleVolumeMount) as nex:
+            LOG.error("Could not mount Quobyte volume: %s", nex)
 
     @utils.synchronized('connect_qb_volume')
     def disconnect_volume(self, connection_info, instance):
         """Disconnect the volume."""
 
-        quobyte_volume = self._normalize_export(
-                                        connection_info['data']['export'])
         mount_path = self._get_mount_path(connection_info)
-
-        if libvirt_utils.is_mounted(mount_path, 'quobyte@' + quobyte_volume):
-            umount_volume(mount_path)
+        try:
+            validate_volume(mount_path)
+        except (nova_exception.InvalidVolume,
+                nova_exception.StaleVolumeMount) as exc:
+            LOG.warning("Could not disconnect Quobyte volume mount: %s", exc)
         else:
-            LOG.info("Trying to disconnected unmounted volume at %s",
-                     mount_path)
+            umount_volume(mount_path)
 
     def _normalize_export(self, export):
         protocol = SOURCE_PROTOCOL + "://"

releasenotes/notes/qb-bug-1730933-6695470ebaee0fbd.yaml

@@ -0,0 +1,5 @@
+---
+fixes:
+  - |
+    Fixes a bug that caused Nova to fail on mounting Quobyte volumes
+    whose volume URL contained multiple registries.