host.py 文件源码

def get_usable_luns(cls, queryset):
        """
        Get all Luns which are not used by Targets and have enough VolumeNode configuration
        to be used as a Target (i.e. have only one node or at least have a primary node set)

        Luns are usable if they have only one VolumeNode (i.e. no HA available but
        we can definitively say where it should be mounted) or if they have
        a primary VolumeNode (i.e. one or more VolumeNodes is available and we
        know at least where the primary mount should be)
        """
        queryset = cls.get_unused_luns(queryset)\
                      .filter(volumenode__host__not_deleted=True)\
                      .annotate(has_primary=BoolOr('volumenode__primary'), num_volumenodes=Count('volumenode'))\
                      .filter(Q(num_volumenodes=1) | Q(has_primary=True))

        return queryset