UnboundLocalError: local variable 'volume' referenced before assignment

[ugvddm]

When the driver was not initialized, I uploaded a volume as image into glance, I got some error as follow:

[01;31mException during message handling: local variable 'volume' referenced before assignment^[[00m
^[[01;31m2014-05-25 00:09:40.599 TRACE oslo.messaging.rpc.dispatcher ^[[01;35m^[[00mTraceback (most recent call last):
^[[01;31m2014-05-25 00:09:40.599 TRACE oslo.messaging.rpc.dispatcher ^[[01;35m^[[00m File "/usr/local/lib/python2.7/dist-packages/oslo/messaging/rpc/dispatcher.py", line 133, in _dispatch_and_reply
^[[01;31m2014-05-25 00:09:40.599 TRACE oslo.messaging.rpc.dispatcher ^[[01;35m^[[00m incoming.message))
^[[01;31m2014-05-25 00:09:40.599 TRACE oslo.messaging.rpc.dispatcher ^[[01;35m^[[00m File "/usr/local/lib/python2.7/dist-packages/oslo/messaging/rpc/dispatcher.py", line 176, in _dispatch
^[[01;31m2014-05-25 00:09:40.599 TRACE oslo.messaging.rpc.dispatcher ^[[01;35m^[[00m return self._do_dispatch(endpoint, method, ctxt, args)
^[[01;31m2014-05-25 00:09:40.599 TRACE oslo.messaging.rpc.dispatcher ^[[01;35m^[[00m File "/usr/local/lib/python2.7/dist-packages/oslo/messaging/rpc/dispatcher.py", line 122, in _do_dispatch
^[[01;31m2014-05-25 00:09:40.599 TRACE oslo.messaging.rpc.dispatcher ^[[01;35m^[[00m result = getattr(endpoint, method)(ctxt, **new_args)
^[[01;31m2014-05-25 00:09:40.599 TRACE oslo.messaging.rpc.dispatcher ^[[01;35m^[[00m File "/opt/stack/cinder/cinder/volume/manager.py", line 721, in copy_volume_to_image
^[[01;31m2014-05-25 00:09:40.599 TRACE oslo.messaging.rpc.dispatcher ^[[01;35m^[[00m if (volume['instance_uuid'] is None and
^[[01;31m2014-05-25 00:09:40.599 TRACE oslo.messaging.rpc.dispatcher ^[[01;35m^[[00mUnboundLocalError: local variable 'volume' referenced before assignment

As we can see the code from cinder/volume/manager.py, the method require_driver_initialized occurs exception so that the method volume_get will be not executed, and the variable 'volume' is not defined.

 def copy_volume_to_image(self, context, volume_id, image_meta):
        payload = {'volume_id': volume_id, 'image_id': image_meta['id']}
        try:
            # NOTE(flaper87): Verify the driver is enabled
            # before going forward. The exception will be caught
            # and the volume status updated.
            utils.require_driver_initialized(self.driver)

            volume = self.db.volume_get(context, volume_id)
            image_service, image_id = \
                glance.get_remote_image_service(context, image_meta['id'])
            self.driver.copy_volume_to_image(context, volume, image_service,
                                             image_meta)
            LOG.debug(_("Uploaded volume %(volume_id)s to "
                        "image (%(image_id)s) successfully"),
                      {'volume_id': volume_id, 'image_id': image_id})
        except Exception as error:
            with excutils.save_and_reraise_exception():
                payload['message'] = unicode(error)
        finally:
            if (volume['instance_uuid'] is None and
                    volume['attached_host'] is None):
                self.db.volume_update(context, volume_id,
                                      {'status': 'available'})
            else:
                self.db.volume_update(context, volume_id,
                                      {'status': 'in-use'})

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/95371

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/95371
Committed: https://git.openstack.org/cgit/openstack/cinder/commit/?id=c08211b19e2b9c38e537e155d11ffced37af0e85
Submitter: Jenkins
Branch: master

commit c08211b19e2b9c38e537e155d11ffced37af0e85
Author: Zhengguang--reset-author <email address hidden>
Date: Tue May 6 09:05:34 2014 +0800

    Add exception handling for copy_volume_to_image()

    The method require_driver_initialized occurs exception so that the
    method volume_get will be not executed, and the variable 'volume'
    will be not defined. In the "finally" code segment, the
    volume['instance_uuid'] will get the UnboundLocalError, this patch
    gets volume before require_driver_initialized to avoid the above
    problem.

    Change-Id: Ic8167383eb67c5016c9853da274455e0f202dc4d
    Closes-Bug: #1322958