Comment 3 for bug 1581230

Reviewed: https://review.openstack.org/335358
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=63805735c25a54ad1b9b97e05080c1a6153d8e22
Submitter: Jenkins
Branch: master

commit 63805735c25a54ad1b9b97e05080c1a6153d8e22
Author: Ildiko Vancsa <email address hidden>
Date: Tue Jun 28 16:05:53 2016 +0200

    Remove check_attach

    This patch finishes to remove the 'check_attach' call from Nova
    completely. As Cinder already performs the required checks as part
    of the 'reserve_volume' (os-reserve) call it is unnecessary to check the
    statemachine in Nova also and it can lead to race conditions.

    The missing 'reserve_volume' call is added to the BFV flow. In case of
    build failure the volume will be locked in 'attaching' state until the
    instance in ERROR state is cleaned up.

    We also check AZ for each volume attach operation which we haven't
    done for unshelve. A release note is added to enable 'cross_az_attach'
    in case the user does not care about AZ.

    The compute service version had to be bumped as the old computes still
    perform 'check_attach', which will fail when the API reserves the
    volume and the volume state moves to 'attaching'. If the computes
    are not new enough the old check will be called as opposed to
    'reserve_volume'.

    Closes-Bug: #1581230
    Change-Id: I3a3caa4c566ecc132aa2699f8c7e5987bbcc863a