Comment 5 for bug 1246327

Reviewed: https://review.openstack.org/54634
Committed: http://github.com/openstack/nova/commit/482dfeb113f1e0ff814aa1fc980d67e0c8b06d76
Submitter: Jenkins
Branch: master

commit 482dfeb113f1e0ff814aa1fc980d67e0c8b06d76
Author: Xavier Queralt <email address hidden>
Date: Wed Oct 30 21:25:55 2013 +0100

    Process image BDM earlier to avoid duplicates

    If the block device mapping from the image properties are not handled at
    the same time as the ones defined from the API, we might make the false
    assumption that the instance has no root and failing or, in the case
    we're booting from an image that only defines a BDM and has no disk,
    creating a local disk BDM as root and ending up with two root devices
    which is forbidden.

    This patch moves the handling of the image block device mappings to the
    same method were we check the ones provided throught the API. This
    allows nova to decide wether the instance needs a local disk from an
    image if no root device is defined in any of the block device mappings.

    Change-Id: Ide95357895ab4dd1338ab5ee3ec25294af1d010b
    Closes-Bug: #1246327