500 error when image is in use though the backend store

When delete image from Glance and if the image is still in use in RBD, Glance will raise 500 error as below:

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2016-02-26 14:23:42.849 2190 ERROR glance.common.wsgi [req-e1ca13af-7662-4122-a3a0-f64e8d75e6c1 79f60e6ab1bf4b2fbe7987c6c2b57e63 94b566de52f9423fab80ceee8c0a4a23 - - -] Caught error: The image cannot be deleted because it is in use through the backend store outside of Glance.
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi Traceback (most recent call last):
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi File "/opt/cat/openstack/glance/local/lib/python2.7/site-packages/glance/common/wsgi.py", line 881, in __call__
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi request, **action_args)
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi File "/opt/cat/openstack/glance/local/lib/python2.7/site-packages/glance/common/wsgi.py", line 909, in dispatch
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi return method(*args, **kwargs)
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi File "/opt/cat/openstack/glance/local/lib/python2.7/site-packages/glance/common/utils.py", line 508, in wrapped
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi return func(self, req, *args, **kwargs)
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi File "/opt/cat/openstack/glance/local/lib/python2.7/site-packages/glance/api/v1/images.py", line 1099, in delete
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi {'status': ori_status})
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi File "/opt/cat/openstack/glance/local/lib/python2.7/site-packages/oslo_utils/excutils.py", line 85, in __exit__
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi six.reraise(self.type_, self.value, self.tb)
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi File "/opt/cat/openstack/glance/local/lib/python2.7/site-packages/glance/api/v1/images.py", line 1095, in delete
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi upload_utils.initiate_deletion(req, loc_data, id)
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi File "/opt/cat/openstack/glance/local/lib/python2.7/site-packages/glance/api/v1/upload_utils.py", line 46, in initiate_deletion
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi id, location_data)
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi File "/opt/cat/openstack/glance/local/lib/python2.7/site-packages/glance/common/store_utils.py", line 124, in delete_image_location_from_backend
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi safe_delete_from_backend(context, image_id, location)
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi File "/opt/cat/openstack/glance/local/lib/python2.7/site-packages/glance/common/store_utils.py", line 58, in safe_delete_from_backend
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi ret = store_api.delete_from_backend(location['url'], context=context)
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi File "/opt/cat/openstack/glance/local/lib/python2.7/site-packages/glance_store/backend.py", line 290, in delete_from_backend
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi return store.delete(loc, context=context)
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi File "/opt/cat/openstack/glance/local/lib/python2.7/site-packages/glance_store/capabilities.py", line 226, in op_checker
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi return store_op_fun(store, *args, **kwargs)
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi File "/opt/cat/openstack/glance/local/lib/python2.7/site-packages/glance_store/_drivers/rbd.py", line 410, in delete
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi self._delete_image(target_pool, loc.image, loc.snapshot)
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi File "/opt/cat/openstack/glance/local/lib/python2.7/site-packages/glance_store/_drivers/rbd.py", line 304, in _delete_image
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi raise exceptions.InUseByStore()
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi InUseByStore: The image cannot be deleted because it is in use through the backend store outside of Glance.
2016-02-26 14:23:42.849 2190 TRACE glance.common.wsgi
2016-02-26 14:23:42.902 2190 INFO eventlet.wsgi.server [req-e1ca13af-7662-4122-a3a0-f64e8d75e6c1 79f60e6ab1bf4b2fbe7987c6c2b57e63 94b566de52f9423fab80ceee8c0a4a23 - - -] 10.13.0.41 - - [26/Feb/2016 14:23:42] "DELETE /v1/images/xxxxxxxxxxxxxxxxxxxxxxx HTTP/1.1" 500 430 0.402856