Merge "Fix regression with live migration on shared storage"

nova/compute/manager.py

@@ -9205,7 +9205,9 @@ class ComputeManager(manager.Manager):
             # vpmem must be cleaned
             do_cleanup = (not migrate_data.is_shared_instance_path or
                           has_vpmem or has_mdevs or power_management_possible)
-            destroy_disks = not migrate_data.is_shared_block_storage
+            destroy_disks = not (
+                    migrate_data.is_shared_block_storage or
+                    migrate_data.is_shared_instance_path)
         elif isinstance(migrate_data, migrate_data_obj.HyperVLiveMigrateData):
             # NOTE(claudiub): We need to cleanup any zombie Planned VM.
             do_cleanup = True

nova/tests/unit/compute/test_compute_mgr.py

@@ -11380,7 +11380,7 @@ class ComputeManagerMigrationTestCase(test.NoDBTestCase,
         do_cleanup, destroy_disks = self.compute._live_migration_cleanup_flags(
                 migrate_data, migr_ctxt)
         self.assertTrue(do_cleanup)
-        self.assertTrue(destroy_disks)
+        self.assertFalse(destroy_disks)
 
     def test_live_migration_cleanup_flags_block_migrate_libvirt(self):
         migrate_data = objects.LibvirtLiveMigrateData(
@@ -11407,7 +11407,7 @@ class ComputeManagerMigrationTestCase(test.NoDBTestCase,
         do_cleanup, destroy_disks = self.compute._live_migration_cleanup_flags(
             migrate_data)
         self.assertFalse(do_cleanup)
-        self.assertTrue(destroy_disks)
+        self.assertFalse(destroy_disks)
 
     def test_live_migration_cleanup_flags_shared_libvirt(self):
         migrate_data = objects.LibvirtLiveMigrateData(
@@ -11418,6 +11418,16 @@ class ComputeManagerMigrationTestCase(test.NoDBTestCase,
         self.assertFalse(do_cleanup)
         self.assertFalse(destroy_disks)
 
+    def test_live_migration_cleanup_flags_shared_path_libvirt_mdev(self):
+        migrate_data = objects.LibvirtLiveMigrateData(
+            is_shared_block_storage=False,
+            is_shared_instance_path=True,
+            target_mdevs={})
+        do_cleanup, destroy_disks = self.compute._live_migration_cleanup_flags(
+            migrate_data)
+        self.assertTrue(do_cleanup)
+        self.assertFalse(destroy_disks)
+
     def test_live_migration_cleanup_flags_live_migrate(self):
         do_cleanup, destroy_disks = self.compute._live_migration_cleanup_flags(
             {})

nova/tests/unit/virt/libvirt/test_driver.py

@@ -21006,7 +21006,8 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         # is_shared_block_storage=True and destroy_disks=False.
         instance = objects.Instance(self.context, **self.test_instance)
         migrate_data = objects.LibvirtLiveMigrateData(
-                is_shared_block_storage=True)
+                is_shared_block_storage=True,
+                is_shared_instance_path=False)
         drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI())
         drvr.cleanup(
             self.context, instance, network_info={}, destroy_disks=False,
@@ -21016,6 +21017,25 @@ class LibvirtConnTestCase(test.NoDBTestCase,
         self.assertTrue(instance.cleaned)
         save.assert_called_once_with()
 
+    @mock.patch.object(libvirt_driver.LibvirtDriver, 'delete_instance_files',
+                       return_value=True)
+    @mock.patch.object(objects.Instance, 'save')
+    @mock.patch.object(libvirt_driver.LibvirtDriver, '_undefine_domain')
+    def test_cleanup_migrate_data_block_storage_and_share_instance_dir(
+        self, _undefine_domain, save, delete_instance_files
+    ):
+        # Test the case when the instance directory is on shared storage
+        # (e.g. NFS) and the instance is booted form volume.
+        instance = objects.Instance(self.context, **self.test_instance)
+        migrate_data = objects.LibvirtLiveMigrateData(
+                is_shared_block_storage=True,
+                is_shared_instance_path=True)
+        drvr = libvirt_driver.LibvirtDriver(fake.FakeVirtAPI())
+        drvr.cleanup(
+            self.context, instance, network_info={}, destroy_disks=False,
+            migrate_data=migrate_data, destroy_vifs=False)
+        delete_instance_files.assert_not_called()
+
     @mock.patch.object(libvirt_driver.LibvirtDriver, 'delete_instance_files',
                        return_value=True)
     @mock.patch.object(objects.Instance, 'save')

nova/virt/libvirt/driver.py

@@ -1705,12 +1705,12 @@ class LibvirtDriver(driver.ComputeDriver):
             cleanup_instance_dir = True
             cleanup_instance_disks = True
         else:
-            # NOTE(mdbooth): I think the theory here was that if this is a
-            # migration with shared block storage then we need to delete the
-            # instance directory because that's not shared. I'm pretty sure
-            # this is wrong.
+            # NOTE(mheler): For shared block storage we only need to clean up
+            # the instance directory when it's not on a shared path.
             if migrate_data and 'is_shared_block_storage' in migrate_data:
-                cleanup_instance_dir = migrate_data.is_shared_block_storage
+                cleanup_instance_dir = (
+                        migrate_data.is_shared_block_storage and
+                        not migrate_data.is_shared_instance_path)
 
             # NOTE(lyarwood): The following workaround allows operators to
             # ensure that non-shared instance directories are removed after an

releasenotes/notes/bug-2080436-568b03b5b5ba5760.yaml

@@ -0,0 +1,8 @@
+---
+fixes:
+  - |
+    Fixes a regression for live migration on shared storage that
+    was removing the backing disk and instance folder during the
+    cleanup of a virtual machine post live migration.
+    `bug 2080436
+    <https://bugs.launchpad.net/nova/+bug/2080436>`__ for details.