From Murillo Fernandes Bernardes <mfb@br.ibm.com>:

From Murillo Fernandes Bernardes <mfb@br.ibm.com>:

The problem is: There is no mechanism to detect block device setup failure

Network devices have the same problem, and are fixed with this too.

I handling this problem in the way suggested by aliguori:
- hotplug scripts write a "hotplug-status" node on store
- Xend DevController.createDevice() check verify this node and return success
or throw an exception on failure.
- If no changes in "hotplug-status" node after DEVICE_CREATE_TIMEOUT seconds
Xend throw an exception showing the problem with hotplug scripts.

Signed-off-by: Ewan Mellor <ewan@xensource.com>