Hyper-V volume attach issue: wrong SCSI slot is selected

[Lucian Petrut]

When attaching volumes, the Hyper-V driver selects the slot on the SCSI controller by using the number of drives attached to that controller.

This leads to exceptions when detaching volumes having lower numbered slots and then attaching a new volume.

Take for example 2 volumes attached which will have 0 and 1 as controller addresses. If the first one gets detached, the next time we'll try to attach a volume the controller address 1 will be used (as it's the number of drives attached to the controller at that time) but that slot is actually uesd, so it will raise an exception.

[Lucian Petrut (petrutlucian94)]

https://review.openstack.org/#/c/99962/

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/99962
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=a73e31022c9fef532cc2d66462d13f4ab2358565
Submitter: Jenkins
Branch: master

commit a73e31022c9fef532cc2d66462d13f4ab2358565
Author: Lucian Petrut <email address hidden>
Date: Fri Jun 13 18:53:51 2014 +0300

    Fixes Hyper-V SCSI slot selection

    Currently, when attaching volumes, the Hyper-V driver selects the
    slot on the SCSI controller by using the number of drives
    attached to that controller.

    This leads to exceptions when detaching volumes having lower
    numbered slots and then attaching a new volume, as Hyper-V will
    then try to use an occupied slot.

    This patch fixes the issue by simply getting a list of used slots
    and getting a slot that it's not among those. It also checks
    for the slot number to be smaller than the maximum number of slots
    per SCSI controller.

    Fixes bug: #1329764

    Change-Id: Id0c09c4debc848004a78971670cc3caef2f77ce3

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/icehouse
Review: https://review.openstack.org/111789

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/111789
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=e874ee231bc8a98c476731e043574a0c00e12a29
Submitter: Jenkins
Branch: stable/icehouse

commit e874ee231bc8a98c476731e043574a0c00e12a29
Author: Denis Denes <email address hidden>
Date: Fri Jun 13 18:53:51 2014 +0300

    Fixes Hyper-V SCSI slot selection

    Currently, when attaching volumes, the Hyper-V driver selects the
    slot on the SCSI controller by using the number of drives
    attached to that controller.

    This leads to exceptions when detaching volumes having lower
    numbered slots and then attaching a new volume, as Hyper-V will
    then try to use an occupied slot.

    This patch fixes the issue by simply getting a list of used slots
    and getting a slot that it's not among those. It also checks
    for the slot number to be smaller than the maximum number of slots
    per SCSI controller.

    Fixes bug: #1329764

    (cherry-picked from commit a73e31022c9fef532cc2d66462d13f4ab2358565)

    Change-Id: Id0c09c4debc848004a78971670cc3caef2f77ce3