'Fetches all possible quota resources.'

@property
def resources(self):

    result = {}
    argses = [('volumes', '_sync_volumes', 'quota_volumes'), ('per_volume_gigabytes', None, 'per_volume_size_limit'), ('snapshots', '_sync_snapshots', 'quota_snapshots'), ('gigabytes', '_sync_gigabytes', 'quota_gigabytes'), ('backups', '_sync_backups', 'quota_backups'), ('backup_gigabytes', '_sync_backup_gigabytes', 'quota_backup_gigabytes')]
    for args in argses:
        resource = ReservableResource(*args)
        result[resource.name] = resource
    volume_types = db.volume_type_get_all(context.get_admin_context(), False)
    for volume_type in volume_types.values():
        for part_name in ('volumes', 'gigabytes', 'snapshots'):
            resource = VolumeTypeResource(part_name, volume_type)
            result[resource.name] = resource
    return result
