cinder.quota.QuotaEngine.get_default function using unexpected argument

[Yang Zhang]

The get_default function in cinder.quota.QuotaEngine calls the _driver's
get_default function, but neither DbQuotaDriver nor NestedDbQuotaDriver
actually takes parent_project_id as an argument; see the code below.

    def get_default(self, context, resource, parent_project_id=None):
        """Get a specific default quota for a resource.

        :param parent_project_id: The id of the current project's parent,
                                  if any.
        """

        return self._driver.get_default(context, resource,
                                        parent_project_id=parent_project_id)

The NestedDbQuotaDriver get_default function is like this:

    def get_default(self, context, resource, project_id):
        """Get a specific default quota for a resource."""
        resource = super(NestedDbQuotaDriver, self).get_default(
            context, resource, project_id)

        return 0 if quota_utils.get_parent_project_id(
            context, project_id) else resource.default

The DbQuotaDriver get_default function is like this:

    def get_default(self, context, resource, project_id):
        """Get a specific default quota for a resource."""
        default_quotas = db.quota_class_get_defaults(context)
        return default_quotas.get(resource.name, resource.default)

I used the get_default function while adding a new quota item,
and the unit tests failed a lot. So I read these codes and find this part
being weired. I think this can be easily fixed, since no one seems using
this function and no unit test runs this part too.

[Deepak Mourya (mourya007)]

Hi Yang, So do you want to write a test for this also or just change in the get_default method.?

[Yang Zhang (wosunoozzy)]

Hi Deepak, if it is indeed a bug, then we have to fix it and add some tests for the code I think :)
Or maybe we can just remove this part if is really usless.

[Deepak Mourya (mourya007)]

I believe updating it to parent_id would be sufficient. What do you think?

[Yang Zhang (wosunoozzy)]

I'm not sure what exactly the author intended to do with "get_default" function in the drivers.
I think maybe we should change the code where the driver's function is called.

self._driver.get_default(context, resource, project_id)

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/cinder/+/819691

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.opendev.org/c/openstack/cinder/+/907152

[OpenStack Infra (hudson-openstack)]

Change abandoned by "Rajat Dhasmana <email address hidden>" on branch: master
Review: https://review.opendev.org/c/openstack/cinder/+/819691
Reason: in favor of https://review.opendev.org/c/openstack/cinder/+/907152 (since i thought doing it over master would be better, it wasn't)