openstack Havana create instances 调用的函数

(Pdb) bt
 /usr/lib/python2.6/site-packages/eventlet/greenpool.py(80)_spawn_n_impl()
-> func(*args, **kwargs)
 /usr/lib/python2.6/site-packages/nova/openstack/common/rpc/amqp.py(461)_process_data()
-> **args)
 /usr/lib/python2.6/site-packages/nova/openstack/common/rpc/dispatcher.py(172)dispatch()
-> result = getattr(proxyobj, method)(ctxt, **kwargs)
 /usr/lib/python2.6/site-packages/nova/exception.py(73)wrapped()
-> return f(self, context, *args, **kw)
 /usr/lib/python2.6/site-packages/nova/compute/manager.py(229)decorated_function()
-> return function(self, context, *args, **kwargs)
 /usr/lib/python2.6/site-packages/nova/compute/manager.py(294)decorated_function()
-> function(self, context, *args, **kwargs)
 /usr/lib/python2.6/site-packages/nova/compute/manager.py(258)decorated_function()
-> return function(self, context, *args, **kwargs)
 /usr/lib/python2.6/site-packages/nova/compute/manager.py(1613)run_instance()
-> do_run_instance()
 /usr/lib/python2.6/site-packages/nova/openstack/common/lockutils.py(246)inner()
-> return f(*args, **kwargs)
 /usr/lib/python2.6/site-packages/nova/compute/manager.py(1612)do_run_instance()
-> legacy_bdm_in_spec)
 /usr/lib/python2.6/site-packages/nova/compute/manager.py(946)_run_instance()
-> instance, image_meta, legacy_bdm_in_spec)
 /usr/lib/python2.6/site-packages/nova/compute/manager.py(1037)_build_instance()
-> set_access_ip=set_access_ip)
 /usr/lib/python2.6/site-packages/nova/compute/manager.py(1407)_spawn()
-> block_device_info)
 /usr/lib/python2.6/site-packages/nova/virt/libvirt/driver.py(2063)spawn()
-> admin_pass=admin_password)
 /usr/lib/python2.6/site-packages/nova/virt/libvirt/driver.py(2381)_create_image()
-> ephemeral_size=int(ephemeral_gb))
 /usr/lib/python2.6/site-packages/nova/virt/libvirt/imagebackend.py(183)cache()
-> *args, **kwargs)
> /usr/lib/python2.6/site-packages/nova/virt/libvirt/imagebackend.py(316)create_image()
-> prepare_template(target=base, max_size=size, *args, **kwargs)
 /usr/lib/python2.6/site-packages/nova/openstack/common/lockutils.py(246)inner()->None
-> return f(*args, **kwargs)
 /usr/lib64/python2.6/contextlib.py(34)__exit__()
-> self.gen.throw(type, value, traceback)
 /usr/lib/python2.6/site-packages/nova/openstack/common/lockutils.py(205)lock()
-> yield lock
 /usr/lib/python2.6/site-packages/nova/openstack/common/lockutils.py(246)inner()->None
-> return f(*args, **kwargs)
 /usr/lib/python2.6/site-packages/nova/virt/libvirt/imagebackend.py(164)call_if_not_exists()