RBD images and exclusive locking

[Peter Lieven]

Hi,


following the thread on the ceph ml about rbd and exclusive locks I was 
wondering if we should rewrite the rbd driver to

try to acquire an exclusive lock on open and not magically on the first write. 
This way we could directly terminate qemu

if the rbd image is in use like it is done with ordinary image files on a 
filesystem for some time now.


Peter