Comment 2 for bug 1280464

There is running process which seems like to be kernel thread [neutron-ns-meta] . I have no idea where does it come from. Based on the name a hot candidate is neutron-ns-metadata-proxy. I'm not able to reproduce it on my own environment.

I added to stop_base in grenade removal of loop device in case it's still present after unmounting swift data successfully with some additional debug information that should provide more details on hanging task.