create_disk_from_image hangs compute process

[Eric Berglund]

The disk driver code that creates a new disk from a glance image will hang the compute process. This is due to a problem with threading. Python contains a Global Interpreter Lock which will run only one thread, causing all of the others to stop. This is normally fine because threads can yield and allow other threads to run. The problem is that the thread is blocking on the open() syscall in nova.image.glance.download which doesn't yield, causing all of the other threads to be frozen.

The solution will come in two parts. First a new version of pypowervm will be created that will avoid threading altogether. Second, FUNC needs to be disabled in nova-powervm.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/453233

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/ocata
Review: https://review.openstack.org/453905

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/newton
Review: https://review.openstack.org/453907

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/453233
Committed: https://git.openstack.org/cgit/openstack/nova-powervm/commit/?id=6c8658088e5d6a86d6f57bd005a326e63aef4353
Submitter: Jenkins
Branch: master

commit 6c8658088e5d6a86d6f57bd005a326e63aef4353
Author: Eric Fried <email address hidden>
Date: Tue Apr 4 10:41:48 2017 -0500

    create_disk_from_image: IO_STREAM instead of FUNC

    Due to incompatibilities between threads and greenlets, uploads with
    UploadType.FUNC can hang the compute process (see bug).

    This change set replaces use of FUNC with IO_STREAM, and requires a new
    release of pypowervm which gets rid of coordinated upload (which also
    suffers from the threading incompatibility problems).

    Change-Id: If819f31f753ae37cabd8dc5cd91fbffacbfbe955
    Partial-Bug: #1679720
    Depends-On: If3ae23ac55acd56d758bc10e4c825882e2b11f01

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/453905
Committed: https://git.openstack.org/cgit/openstack/nova-powervm/commit/?id=55c0edab38bf128dc8cf4a601f9779be3ac87e24
Submitter: Jenkins
Branch: stable/ocata

commit 55c0edab38bf128dc8cf4a601f9779be3ac87e24
Author: Eric Fried <email address hidden>
Date: Wed Apr 5 16:36:09 2017 -0500

    create_disk_from_image: IO_STREAM instead of FUNC

    Due to incompatibilities between threads and greenlets, uploads with
    UploadType.FUNC can hang the compute process (see bug).

    This change set replaces use of FUNC with IO_STREAM, and requires a new
    release of pypowervm which gets rid of coordinated upload (which also
    suffers from the threading incompatibility problems).

    Change-Id: If819f31f753ae37cabd8dc5cd91fbffacbfbe955
    Closes-Bug: #1679720

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/453907
Committed: https://git.openstack.org/cgit/openstack/nova-powervm/commit/?id=eedc5959cc93efb2af5b5f32448f1f38860cea20
Submitter: Jenkins
Branch: stable/newton

commit eedc5959cc93efb2af5b5f32448f1f38860cea20
Author: Eric Fried <email address hidden>
Date: Wed Apr 5 16:36:09 2017 -0500

    create_disk_from_image: IO_STREAM instead of FUNC

    Due to incompatibilities between threads and greenlets, uploads with
    UploadType.FUNC can hang the compute process (see bug).

    This change set replaces use of FUNC with IO_STREAM, and requires a new
    release of pypowervm which gets rid of coordinated upload (which also
    suffers from the threading incompatibility problems).

    Change-Id: If819f31f753ae37cabd8dc5cd91fbffacbfbe955
    Closes-Bug: #1679720

[Eric Fried (efried)]

pypowervm 1.1.8 via
https://github.com/powervm/pypowervm/commit/6a154374997603e89272f4c8f035aea03941ec3e
and
https://github.com/powervm/pypowervm/commit/9d25f41d2908419f7bb070f2a461acc03d07af3f