Volume operations should set task state

[Phil Day]

Volume attach/detach/swap should set task_state so that conflicting operations such as migrate can be blocked via the check_instance_state decorator.

This would also allow users can see slow operations are still in progress.

[Phil Day (philip-day)]

https://review.openstack.org/#/c/71165/

[OpenStack Infra (hudson-openstack)]

Change abandoned by Sean Dague (<email address hidden>) on branch: master
Review: https://review.openstack.org/71165
Reason: This has been in merge conflict since April, abandoning. Please restore and rebase if this is still a thing.

[Paul Murray (pmurray)]

Should have unassigned that before - sorry.

After discussion we decided not to address this immediately. The issue is that using task states will serialize volume attach/detach operations. At the moment multiple volume detach or attach operations can be done in parallel. We need to decide if we want to keep that or not.

Another solution would be to check running actions/tasks instead of a single task state.

[Markus Zoeller (markus_z) (mzoeller)]

This is an automated cleanup. This bug report has been closed because it
is older than 18 months and there is no open code change to fix this.
After this time it is unlikely that the circumstances which lead to
the observed issue can be reproduced.

If you can reproduce the bug, please:
* reopen the bug report (set to status "New")
* AND add the detailed steps to reproduce the issue (if applicable)
* AND leave a comment "CONFIRMED FOR: <RELEASE_NAME>"
  Only still supported release names are valid (LIBERTY, MITAKA, OCATA, NEWTON).
  Valid example: CONFIRMED FOR: LIBERTY