Comment 1 for bug 1826115

Some log deleting snapshot with ceph 12.2.10:
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server [req-732fd601-576e-4a22-ae0e-35f1b6e62b62 fc26707fe5254e729431d3017250949e d900ebe92343410888fcd10c6c7737fb - - -] Exception during message handling: ImageNotFound: [errno 2] error listing images
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server Traceback (most recent call last):
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/server.py", line 163, in _process_incoming
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server res = self.dispatcher.dispatch(message)
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/dispatcher.py", line 220, in dispatch
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server return self._do_dispatch(endpoint, method, ctxt, args)
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/oslo_messaging/rpc/dispatcher.py", line 190, in _do_dispatch
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server result = func(ctxt, **new_args)
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server File "<string>", line 2, in delete_snapshot
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/cinder/coordination.py", line 151, in _synchronized
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server return f(*a, **k)
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/cinder/volume/manager.py", line 1205, in delete_snapshot
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server snapshot.save()
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/oslo_utils/excutils.py", line 220, in _exit_
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server self.force_reraise()
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/oslo_utils/excutils.py", line 196, in force_reraise
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server six.reraise(self.type_, self.value, self.tb)
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/cinder/volume/manager.py", line 1195, in delete_snapshot
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server self.driver.delete_snapshot(snapshot)
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/cinder/volume/drivers/rbd.py", line 1335, in delete_snapshot
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server children_list = self._get_children_info(volume, snap_name)
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/cinder/volume/drivers/rbd.py", line 1156, in _get_children_info
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server children_list = volume.list_children()
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/eventlet/tpool.py", line 186, in doit
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server result = proxy_call(self._autowrap, f, *args, **kwargs)
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/eventlet/tpool.py", line 144, in proxy_call
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server rv = execute(f, *args, **kwargs)
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/eventlet/tpool.py", line 125, in execute
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server six.reraise(c, e, tb)
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server File "/usr/lib/python2.7/site-packages/eventlet/tpool.py", line 83, in tworker
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server rv = meth(*args, **kwargs)
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server File "rbd.pyx", line 2239, in rbd.Image.list_children (/home/jenkins-build/build/workspace/ceph-build/ARCH/x86_64/AVAILABLE_ARCH/x86_64/AVAILABLE_DIST/centos7/DIST/centos7/MACHINE_SIZE/huge/release/12.2.11/rpm/el7/BUILD/ceph-12.2.11/build/src/pybind/rbd/pyrex/rbd.c:20305)
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server ImageNotFound: [errno 2] error listing images
2019-04-11 15:00:00.720 100073 ERROR oslo_messaging.rpc.server