vmware driver races to create instance images

[Dan Smith]

Change Ia0ebd674345734e7cfa31ccd400fdba93646c554 traded one race condition for another. By ignoring all mkdir() calls that would otherwise fail because an instance directory already exists, two nodes racing to create a single image will corrupt or lose data, or fail in a strange way. This call should fail in that case, but doesn't after the recent patch was merged:

https://github.com/openstack/nova/blob/master/nova/virt/vmwareapi/vmops.py#L350

[Matt Riedemann (mriedem)]

Reverted here https://review.openstack.org/#/c/75989/

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/76071

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/75989
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=2190e998c9667e4d4680d87a9d1643e25175dc8d
Submitter: Jenkins
Branch: master

commit 2190e998c9667e4d4680d87a9d1643e25175dc8d
Author: Dan Smith <email address hidden>
Date: Mon Feb 24 12:45:31 2014 -0800

    Revert "VMware: fix race for datastore directory existence"

    This reverts commit 743b74d59d3279478c512a0a559642b1d05284bc,
    which introduces a race condition when creating the initial
    instance image. Since _mkdir() no longer fails if the directory
    exists, two computes racing to create the same image will
    result in either corrupted data, lost data, or a strange
    failure later on.

    Change-Id: Ic646a01b2f96b1341af38b69c372875a95263bad
    Closes-bug: #1284312

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/76071
Committed: https://git.openstack.org/cgit/openstack/nova/commit/?id=a17d38b96c4b776de8938195f86953ff26f94c2f
Submitter: Jenkins
Branch: master

commit a17d38b96c4b776de8938195f86953ff26f94c2f
Author: Shawn Hartsock <email address hidden>
Date: Mon Feb 24 20:59:16 2014 -0500

    vmware: driver races to create instance images

    Addresses race condition that occurs when multiple processes
    arrive at a fresh Datastore with no vmware_base cache directory.

    Change-Id: If1bb6804e3668a56872a653a8ea44d0c7fc70311
    Co-Authored-by: Tracy Jones <email address hidden>
    closes-bug: #1284312