Errors in volume usage audit script

[Michael Kerrin]

We are seeing the following errors from the volume usage audit in relation to snapshots:

Traceback (most recent call last):
  File "/usr/bin/cinder-volume-usage-audit", line 103, in <module>
    extra_info)
  File "/usr/lib/python2.7/dist-packages/cinder/volume/utils.py", line 139, in notify_about_snapshot_usage
    usage_info = _usage_from_snapshot(context, snapshot, **extra_usage_info)
  File "/usr/lib/python2.7/dist-packages/cinder/volume/utils.py", line 117, in _usage_from_snapshot
    'availability_zone': snapshot_ref.volume['availability_zone'],
  File "/usr/lib/python2.7/dist-packages/sqlalchemy/orm/attributes.py", line 168, in __get__
    return self.impl.get(instance_state(instance),dict_)
  File "/usr/lib/python2.7/dist-packages/sqlalchemy/orm/attributes.py", line 453, in get
    value = self.callable_(state, passive)
  File "/usr/lib/python2.7/dist-packages/sqlalchemy/orm/strategies.py", line 481, in _load_for_state
    (mapperutil.state_str(state), self.key)
DetachedInstanceError: Parent instance <Snapshot at 0x3c45050> is not bound to a Session; lazy load operation of attribute 'volume' cannot proceed

And later we found the following error:

Traceback (most recent call last):
  File "/usr/bin/cinder-volume-usage-audit", line 103, in <module>
    extra_info)
  File "/usr/lib/python2.7/dist-packages/cinder/volume/utils.py", line 139, in notify_about_snapshot_usage
    usage_info = _usage_from_snapshot(context, snapshot, **extra_usage_info)
  File "/usr/lib/python2.7/dist-packages/cinder/volume/utils.py", line 117, in _usage_from_snapshot
    'availability_zone': snapshot_ref.volume['availability_zone'],
TypeError: 'NoneType' object has no attribute '__getitem__'

These are both two issue but both relate to the query used to find active snapshots in the audit window so I am putting into the one ticket.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/44868

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/44868
Committed: http://github.com/openstack/cinder/commit/f5e4e39664a233ebe655914f280b699138c6d9b4
Submitter: Jenkins
Branch: master

commit f5e4e39664a233ebe655914f280b699138c6d9b4
Author: Michael Kerrin <email address hidden>
Date: Tue Sep 3 12:53:34 2013 +0000

    Fix errors in volume usage audit script

    The snapshot_get_active_by_window DB query was returning snapshots
    where we couldn't access the related volume object. This was due to
    a) the volume not been loaded and the join failing due to detached
    session object.
    and b) the related volume was deleted so it didn't show return from
    the join

    Fixes bug: 1220140

    Change-Id: I0de993ba0ca482fa9ab80d4d5cdb0ff5cc8e4d7a