Open Stack

Hi, I'd like you to take a look at this patch for potential
SecurityImpact.
https://review.openstack.org/82841

Log:
commit 3ebf229abcea0c79cda0be03c7bb27d136c1f725
Author: David Ripton <dripton at redhat.com>
Date:   Tue Jan 28 16:38:51 2014 -0500

    Persist image format to a file, to prevent attacks based on changing it
    
    The attack is based on creating a raw image that looks like a qcow2
    image, and taking advantage of the code that used 'qemu-img info' to
    autodetect the image format.
    
    Now we store the image format to a 'disk.info' file, for Qcow2 and Raw
    images, and only autodetect for images that have never been written to
    that file.
    
    SecurityImpact
    
    Closes-bug: #1221190
    
    Conflicts:
    	nova/virt/libvirt/imagebackend.py
    
    Manual tweaks to some mocking in test_imagebackend.py
    
    Change-Id: I2016efdb3f49a44ec4d677ac596eacc97871f30a
    (cherry picked from commit 7fc3440cd3ad799a743797077aaffb0a3910d1e4)