sometimes instances stay in DELETE vm_state but are not marked as deleted

[Andrea Rosa]

This is not a common case, but I verified that we can have a kind of partial deletion of instances.
What I saw is that instances have vm_state = DELETED but are not marked (in the DB) as deleted.

Looking at the code it's clear that the combination of vm_sate=DELETED and deleted=0 is a valid combination even if it should be a short lived one.
I think that if we find instances in that state during the _init_instance method we have to complete the deletion calling the self.conductor_api.instance_destroy(context, instance).
At this moment in the _init_instance method we are ignoring instances in that state:

def _init_instance(self, context, instance):
        '''Initialize this instance during service init.'''
        closing_vm_states = (vm_states.DELETED,
                             vm_states.SOFT_DELETED)

        # instance was supposed to shut down - don't attempt
        # recovery in any case
        if instance['vm_state'] in closing_vm_states:
            return

[Andrea Rosa (andrea-rosa-m)]

I think we need to perform the following actions to get to the point where we can consider the deletion completed:
- call the instance_destroy
- create the quota reservations for instnces, ram and cores quota usages
- commit the quota changes (quota_commit passing the reservations created at the previous step)
- call the block_device_mapping_destroy
- call the notify_about_instance_usage
- if vnc or spice are enabled, procced to the deletion of tokens

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/33265

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/33265
Committed: http://github.com/openstack/nova/commit/6e8737c3aa52889394e843272f3a7e5a3a5935c1
Submitter: Jenkins
Branch: master

commit 6e8737c3aa52889394e843272f3a7e5a3a5935c1
Author: Andrea Rosa <email address hidden>
Date: Mon Jun 10 15:35:53 2013 +0100

    Complete deletion when compute manager start-up.

    Sometimes instances stay in DELETED state (vm_state) but are not
    marked as deleted in the DB.
    The combination of vm_state=DELETED and deleted=0 is a valid
    combination but if we found it during the compute manager start-up that is
    an indication that something went wrong while we were deleting an instance.
    The aim of this change is just to complete the deletion during the compute
    mangager start-up for instances found in that state.

    bug 1187422
    Change-Id: I52efa07b4d98106214fc54aee3af9de6eacb58d9