Instead of writing errors to

/local/domain/0/backend/<devclass>/<dom>/<devid>/error, write them instead to
/local/domain/0/error/backend/<yada>.  This is not the best place for them
perhaps, but it moves them out of the backend directory, on which the drivers
have a watch.  This fixes the problem whereby writing an error will trigger a
watch, causing the error message to be written again, and repeat.  Fixes bug
#286.
 
Signed-off-by: Ewan Mellor <ewan@xensource.com>

tools/python/xen/util/diagnose.py

@@ -107,7 +107,9 @@ def diagnose_devices():
                 print ("Cannot find backend path for device %s, %s." %
                        (deviceClass, device))
             else:
-                backend_error = xstransact.Read(backendPath, 'error')
+                backend_error = xstransact.Read(
+                    backendPath.replace('backend/', 'error/backend/'),
+                    'error')
 
                 if backend_error:
                     diagnose_device_error(backend_error)