Comment 18 for bug 1371677

Pulling this together, the update_available_resource periodic task is using the resource tracker to update host stats, and that rt method is locking on the 'compute_resource' lock, which is also what the resize_claim and drop_resize_claim methods in the resource tracker are locked on, and that's where we hit the timeout in the resize test - it's waiting to make a resize claim but the blockdev blocking call in the update_available_resource periodic task is taking too long, causing the 60 second RPC messaging timeout for the resize claim in the test run.