[Stable Only] Remove soft-deleted instances from quota_usages

The resources in quota_usages table will minus 1 while
soft deleting an instance. But the soft-deleted instances
are counted when synchronizing quota_usages using command
"nova-manage project quota_usage_refresh". So we filter
out soft-deleted instances when synchronizing quota_usage.

We didn't need to do this on master as the quota_usage_refresh
command has been removed in 17.0.0 (Queens). And the
_instance_data_get_for_user function is already removed
in commit c881e77819.
https://review.openstack.org/#/c/570865/

Change-Id: I8dcbe1e5f3f70ddd7067fed1125ef3379044ab0f
Closes-bug: #1773542
(cherry picked from commit 58538ace35)

nova/db/sqlalchemy/api.py

@@ -1833,11 +1833,15 @@ def instance_create(context, values):
 
 
 def _instance_data_get_for_user(context, project_id, user_id):
+    not_soft_deleted = or_(
+        models.Instance.vm_state != vm_states.SOFT_DELETED,
+        models.Instance.vm_state == null()
+    )
     result = model_query(context, models.Instance, (
         func.count(models.Instance.id),
         func.sum(models.Instance.vcpus),
         func.sum(models.Instance.memory_mb))).\
-        filter_by(project_id=project_id)
+        filter_by(project_id=project_id).filter(not_soft_deleted)
     if user_id:
         result = result.filter_by(user_id=user_id).first()
     else:

nova/tests/unit/db/test_db_api.py

@@ -1347,6 +1347,24 @@ class SqlAlchemyDbApiTestCase(DbTestCase):
                               filters={},
                               sort_keys=keys)
 
+    def test_instance_data_get_for_user(self):
+        ctxt = context.get_admin_context()
+        instance_1 = self.create_instance_with_args(project_id='project-HHD')
+        self.create_instance_with_args(project_id='project-HHD')
+
+        @sqlalchemy_api.pick_context_manager_reader
+        def test(context):
+            return sqlalchemy_api._instance_data_get_for_user(
+                context, 'project-HHD', None)
+
+        inst_num, _, _ = test(ctxt)
+        self.assertEqual(2, inst_num)
+
+        db.instance_update(ctxt, instance_1['uuid'],
+                           {"vm_state": vm_states.SOFT_DELETED})
+        inst_num_2, _, _ = test(ctxt)
+        self.assertEqual(1, inst_num_2)
+
 
 class ProcessSortParamTestCase(test.TestCase):