Unshelve can cause quota over-consumption

[Lars Erik Pedersen]

Description
===========
Unshelving a VM can cause an over consumption of a project's quota. I'm not sure if this is a bug or if it's actually intended behaviour, but in my opinion this should not be possible since this will allow users to potentially use a lot more resources than their intended quota.

Steps to reproduce
==================
* Create a project with a quota of i.e. 4 CPUs and 4GB of RAM
* Create server1 with 2 CPUs and 2GB RAM, and shelve it after it successfully spawns
* When server1 in shelved, create server2 with 4 CPUs and 4GB of RAM (effectively using up the entire CPU and RAM quota of the project)
* Unshelve server1

Expected result
===============
I would then expect that unshelving server1 would fail, since the quota was used up by server2

Actual result
=============
Unshelving server1 is completed, and I have now used 6 of 4 CPUs and 6 of 4GB RAM on my project's quota. FWIW this also works if at the time of unshelving the quota is already used up.

Environment
===========
Openstack Yoga
nova-api 3:25.1.1-0ubuntu1~cloud0
nova-scheduler 3:25.1.1-0ubuntu1~cloud0

Running KVM/libvirt on Ubuntu 20.04 and Ceph 17.x

[sean mooney (sean-k-mooney)]

this sound like you have count_usage_from_placement=true

https://docs.openstack.org/nova/latest/configuration/config.html#quota.count_usage_from_placement

in which case this is not a bug and is the intended behavior

thee was a bug related to this which i belvie was fixed recently
it may or may not be backproted to yoga