Fix mypy errors

Fix the argument type mismatches detected now.

Change-Id: I0f1b7cbee9fc64fd1dba8c488a0634cbbe23adb6

cinder/backup/manager.py

@@ -384,7 +384,7 @@ class BackupManager(manager.SchedulerDependentManager):
         self._notify_about_backup_usage(context, backup, "create.start")
 
         expected_status = "backing-up"
-        if snapshot_id:
+        if snapshot:
             actual_status = snapshot['status']
             if actual_status != expected_status:
                 err = _('Create backup aborted, expected snapshot status '
@@ -546,7 +546,7 @@ class BackupManager(manager.SchedulerDependentManager):
                                 message_field.Detail.DETACH_ERROR)
         except Exception as err:
             with excutils.save_and_reraise_exception():
-                if snapshot_id:
+                if snapshot:
                     snapshot.status = fields.SnapshotStatus.AVAILABLE
                     snapshot.save()
                 else:
@@ -838,7 +838,7 @@ class BackupManager(manager.SchedulerDependentManager):
                      {'volume_id': volume.id, 'backup_id': backup.id})
 
             key_mgr = key_manager.API(CONF)
-            if orig_key_id is not None:
+            if orig_key_id:
                 LOG.debug('Deleting original volume encryption key ID.')
                 volume_utils.delete_encryption_key(context,
                                                    key_mgr,

cinder/volume/flows/api/create_volume.py

@@ -356,11 +356,12 @@ class ExtractVolumeRequestTask(flow_utils.CinderTask):
             self,
             key_manager,
             context: context.RequestContext,
-            volume_type_id: str,
+            volume_type_id: Optional[str],
             snapshot: Optional[objects.Snapshot],
             source_volume: Optional[objects.Volume],
             image_metadata: Optional[dict[str, Any]]) -> Optional[str]:
-        if volume_types.is_encrypted(context, volume_type_id):
+        if volume_type_id and volume_types.is_encrypted(
+                context, volume_type_id):
             encryption_key_id = None
 
             if snapshot is not None:  # creating from snapshot

cinder/volume/volume_types.py

@@ -324,7 +324,7 @@ def remove_volume_type_access(context: context.RequestContext,
 
 
 def is_encrypted(context: context.RequestContext,
-                 volume_type_id: str) -> bool:
+                 volume_type_id: Optional[str]) -> bool:
     return get_volume_type_encryption(context, volume_type_id) is not None
 
 
@@ -444,7 +444,7 @@ def volume_types_diff(context: context.RequestContext,
 
 def volume_types_encryption_changed(
         context: context.RequestContext,
-        vol_type_id1: str, vol_type_id2: str) -> bool:
+        vol_type_id1: Optional[str], vol_type_id2: Optional[str]) -> bool:
     """Return whether encryptions of two volume types are same."""
     def _get_encryption(enc: dict) -> dict:
         enc = dict(enc)