Hi,

This patch introduces a new "online" node for backend drivers.

Driver changes:  Make backend drivers check it when entering Closed
state, only unregister devices when the "online" node is either "0" or
not present.  The later maintains backward compatibility.

Tools changes:  Update "online" node when creating and hot-unplugging
devices.

Background: When kexec'ing a new kernel, the old kernel's frontend
driver will shutdown, but the backend device should *NOT* disappear
due to that, so the new kernel instance can reconnect.

please apply,

  Gerd

-- 
Gerd Hoffmann <kraxel@suse.de>
http://www.suse.de/~kraxel/julika-dora.jpeg