Comment 34 for bug 1177830

Reviewed: https://review.openstack.org/54767
Committed: http://github.com/openstack/nova/commit/3cdfe894ab58f7b91bf7fb690fc5bc724e44066f
Submitter: Jenkins
Branch: stable/havana

commit 3cdfe894ab58f7b91bf7fb690fc5bc724e44066f
Author: Pádraig Brady <email address hidden>
Date: Fri Sep 27 04:07:14 2013 +0100

    ensure we don't boot oversized images

    Since we can't generally shrink incoming images, add extra checks
    to ensure oversized images are not allowed through.
    All cases when populating the libvirt image cache are now handled,
    including the initial download from glance, where we avoid
    converting to raw, as that could generate non sparse images
    much larger than the downloaded image.

    * nova/virt/libvirt/utils.py (fetch_image): Allow passing through
    of the max_size parameter.
    * nova/virt/images.py (fetch_to_raw): Accept the max_size parameter,
    and use it to discard images with larger (virtual) sizes.
    * nova/virt/libvirt/imagebackend.py (verify_base_size): A new
    refactored function to identify and raise exception to oversized images.
    (Raw.create_image): Pass the max_size to the fetch function.
    Also enforce virtual image size checking for already fetched images,
    as this class (despite the name) can be handling qcow files.
    (Qcow2.create_image): Pass the max_size to the fetch function,
    or verify the virtual size for the instance as done previously.
    (Lvm.create_image): Pass the max_size to the fetch function.
    Also check the size before transferring to the volume to improve
    efficiency by not even attempting the transfer of oversized images.
    (Rbd.create_image): Likewise.
    * nova/tests/virt/libvirt/fake_libvirt_utils.py: Support max_size arg.
    * nova/tests/virt/libvirt/test_libvirt.py (test_fetch_raw_image):
    Add a case to check oversized images are discarded.
    * nova/tests/virt/libvirt/test_imagebackend.py
    (test_create_image_too_small): Adjust to avoid the fetch size check.

    Fixes bug: 1177830
    Fixes bug: 1206081
    Change-Id: I3d47adaa2ad07434853f447feb27d7aae0e2e717