Fix mistakes introduced with QoSSpecs object

If15ea8b628a6f88211a5d5cc7aadff44f7840138 introduced some mistakes that
I was able to identify when rebasing RequestSpec object patch:

* Missing loading volume_types relationship in QualityOfServiceSpecs
  _from_db_object.
* Wrong source of qos_specs relationship in VolumeType _from_db_object.
* Inefficient loading od QoSSpecs associations in db layer.
* Use of self in classmethod.

This commit fixes the issues.

Change-Id: I3b78127791a03e1a35a30d7f84f66e97d89c7cf9
Closes-Bug: 1603472

cinder/db/sqlalchemy/api.py

@@ -3089,9 +3089,11 @@ def volume_type_qos_associations_get(context, qos_specs_id, inactive=False):
                            models.QualityOfServiceSpecs,
                            qos_specs_id):
         raise exception.QoSSpecsNotFound(specs_id=qos_specs_id)
-    return model_query(context, models.VolumeTypes,
-                       read_deleted=read_deleted). \
-        filter_by(qos_specs_id=qos_specs_id).all()
+    vts = (model_query(context, models.VolumeTypes, read_deleted=read_deleted).
+           options(joinedload('extra_specs')).
+           options(joinedload('projects')).
+           filter_by(qos_specs_id=qos_specs_id).all())
+    return vts
 
 
 @require_admin_context

cinder/objects/qos_specs.py

@@ -113,7 +113,10 @@ class QualityOfServiceSpecs(base.CinderPersistentObject,
                 self._context, self.id)
 
     @staticmethod
-    def _from_db_object(context, qos_spec, db_qos_spec):
+    def _from_db_object(context, qos_spec, db_qos_spec, expected_attrs=None):
+        if expected_attrs is None:
+            expected_attrs = []
+
         for name, field in qos_spec.fields.items():
             if name not in QualityOfServiceSpecs.OPTIONAL_FIELDS:
                 value = db_qos_spec.get(name)
@@ -123,6 +126,11 @@ class QualityOfServiceSpecs(base.CinderPersistentObject,
                     value = {}
                 setattr(qos_spec, name, value)
 
+        if 'volume_types' in expected_attrs:
+            volume_types = objects.VolumeTypeList.get_all_types_for_qos(
+                context, db_qos_spec['id'])
+            qos_spec.volume_types = volume_types
+
         qos_spec._context = context
         qos_spec.obj_reset_changes()
         return qos_spec

cinder/objects/volume_type.py

@@ -88,9 +88,7 @@ class VolumeType(base.CinderPersistentObject, base.CinderObject,
             type.projects = db_type.get('projects', [])
         if 'qos_specs' in expected_attrs:
             qos_specs = objects.QualityOfServiceSpecs(context)
-            qos_specs._from_db_object(context,
-                                      qos_specs,
-                                      type['qos_specs'])
+            qos_specs._from_db_object(context, qos_specs, db_type['qos_specs'])
             type.qos_specs = qos_specs
         type._context = context
         type.obj_reset_changes()
@@ -143,7 +141,7 @@ class VolumeTypeList(base.ObjectListBase, base.CinderObject):
                                   expected_attrs=expected_attrs)
 
     @classmethod
-    def get_all_types_for_qos(self, context, qos_id):
+    def get_all_types_for_qos(cls, context, qos_id):
         types = db.qos_specs_associations_get(context, qos_id)
-        return base.obj_make_list(context, self(context), objects.VolumeType,
+        return base.obj_make_list(context, cls(context), objects.VolumeType,
                                   types)

cinder/tests/unit/test_qos_specs.py

@@ -231,6 +231,8 @@ class QoSSpecsTestCase(test.TestCase):
             }
             self.assertIn(expected_type, res)
 
+        e = exception.QoSSpecsNotFound(specs_id='Trouble')
+        mock_qos_specs_associations_get.side_effect = e
         self.assertRaises(exception.CinderException,
                           qos_specs.get_associations, self.ctxt,
                           'Trouble')

cinder/volume/qos_specs.py

@@ -135,8 +135,8 @@ def delete_keys(context, qos_specs_id, keys):
 def get_associations(context, qos_specs_id):
     """Get all associations of given qos specs."""
     try:
-        qos_spec = objects.QualityOfServiceSpecs.get_by_id(
-            context, qos_specs_id)
+        types = objects.VolumeTypeList.get_all_types_for_qos(context,
+                                                             qos_specs_id)
     except db_exc.DBError:
         LOG.exception(_LE('DB error:'))
         msg = _('Failed to get all associations of '
@@ -145,7 +145,7 @@ def get_associations(context, qos_specs_id):
         raise exception.CinderException(message=msg)
 
     result = []
-    for vol_type in qos_spec.volume_types:
+    for vol_type in types:
         result.append({
             'association_type': 'volume_type',
             'name': vol_type.name,

tools/lintstack.py

@@ -95,6 +95,8 @@ objects_ignore_messages = [
     "Module 'cinder.objects' has no 'SnapshotList' member",
     "Module 'cinder.objects' has no 'Volume' member",
     "Module 'cinder.objects' has no 'VolumeList' member",
+    "Module 'cinder.objects' has no 'VolumeType' member",
+    "Module 'cinder.objects' has no 'VolumeTypeList' member",
 ]
 objects_ignore_modules = ["cinder/objects/"]