I think we need to just revert that patch entirely, as the approach it takes is not safe. It injects the probing into the imagebackend.py code, which means it is run in every single code path that uses the image backends.
To address the bug 1163009 safely, we would need something that only does the probing when the image is first downloaded from glance. The detected format should then be recorded (in the database?) and used for all subsequent boots of that image, whether normal start, or rescue start, or something else.
I think we need to just revert that patch entirely, as the approach it takes is not safe. It injects the probing into the imagebackend.py code, which means it is run in every single code path that uses the image backends.
To address the bug 1163009 safely, we would need something that only does the probing when the image is first downloaded from glance. The detected format should then be recorded (in the database?) and used for all subsequent boots of that image, whether normal start, or rescue start, or something else.