fix _get_bdm_image_metadata and semantics

[Christopher Lefelhocz]

There are two issues to potentially address:

1) _get_bdm_image_metadata currently returns a subset of metadata depending on which block device mapping is being examined. For instance if the block is an image then return the properties metadata. if the bdm is a volume, then we return the volume_image_metadata. These should either be refactored out or the name should change somehow.
2) The semantics are different between two types. An image will return an empty dictionary if no properties exist (which makes sense because customers could have not metadata defined). The volume will fail with an exception if no volume_image_metadata exists. This should be addressed in some fashion.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/46221

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/46221
Committed: http://github.com/openstack/nova/commit/1b1921f5f0cb4c5cb565af222b4c2d6a6531a717
Submitter: Jenkins
Branch: master

commit 1b1921f5f0cb4c5cb565af222b4c2d6a6531a717
Author: Xavier Queralt <email address hidden>
Date: Thu Sep 12 10:57:43 2013 +0200

    Don't fail if volume has no image metadata

    In the same way that nova shouldn't fail when booting an instance if the
    image has no metadata, when booting from a volume it should accept the
    fact that it has no image_metadata and return an empty dict.

    Fixes bug #1220814

    Change-Id: Idc0ff2106415a0662e57021e918dc5c6bf9a9a92

[PraveenKumar (praveenkumar-2608)]

I am facing the same issue with Icehouse. Could you please give me detail procedure on how to apply this fix

[PraveenKumar (praveenkumar-2608)]

I am facing the same issue with Icehouse. Could you please give me detail procedure on how to apply this fix