Update InstanceNUMACell version after data migration

The data migration of InstanceNUMACell 1.4 to 1.5 only moved the data to
the new pcpuset field but does not update the ovo version string of the
object in the DB. This resulted in an 1.6 data with an 1.4 version
string in the DB which subsequently causes that an old compute running
1.4 ovo version will think it got an old ovo even though the data is
already in the new format. This leads to instance lifecycle errors and
if the nova-compute saves the instance then it also leads to permanent
data loss.

So this change modified the data migration to also update the ovo version
in the DB so that the version string in the DB matches the schema the
data uses in the DB.

Related-Bug: #2097359
Change-Id: I9a99f10526f8e466ac04b035121b24be70a23dae
(cherry picked from commit 643a6a8)
(cherry picked from commit 7ff108b)
(cherry picked from commit f6be113)
(cherry picked from commit 2ffc00c)

Author: gibizer

nova/objects/instance_numa.py

@@ -198,14 +198,23 @@ def _migrate_legacy_dedicated_instance_cpuset(cls, obj):
         for cell in obj.cells:
             if len(cell.cpuset) == 0:
                 continue
-
+            # NOTE(gibi): This data migration populates the pcpuset field that
+            # is new in version 1.5. However below we bump the object version
+            # to 1.6 directly. This is intentional. The version 1.6 introduced
+            # a new possible value 'mixed' for the cpu_policy field. As that
+            # is a forward compatible change we don't have a specific data
+            # migration for it. But we also don't have an automated way to bump
+            # old object versions from 1.5 to 1.6. So we do it here just to
+            # avoid inconsistency between data and version in the DB.
             if cell.cpu_policy == obj_fields.CPUAllocationPolicy.DEDICATED:
                 cell.pcpuset = cell.cpuset
                 cell.cpuset = set()
+                cell.VERSION = '1.6'
                 update_db = True
             else:
                 if 'pcpuset' not in cell:
                     cell.pcpuset = set()
+                    cell.VERSION = '1.6'
                     update_db = True
 
         return update_db

nova/tests/unit/objects/test_instance_numa.py

@@ -446,11 +446,8 @@ def test__migrate_legacy_dedicated_instance_cpuset(self):
         # pcpuset
         self.assertEqual(set(), topo_loaded.cells[0].cpuset)
         self.assertEqual({0, 1}, topo_loaded.cells[0].pcpuset)
-        # but the object version isn't bumped. So when the
-        # data is saved back to the DB it still has the old version 1.4, but
-        # also it has the new pcpuset field from version 1.6. This is bug
-        # https://bugs.launchpad.net/nova/+bug/2097359.
-        self.assertEqual('1.4', topo_loaded.cells[0].VERSION)
+        # and the version is bumped to 1.6
+        self.assertEqual('1.6', topo_loaded.cells[0].VERSION)
 
 
 class TestInstanceNUMATopology(