Re: calling vif hotplug scripts more than once

[Olaf Hering <olaf@aepfle.de>]

On Tue, Jul 08, Ian Jackson wrote:

> Olaf Hering writes ("Re: calling vif hotplug scripts more than once"):
> > On Tue, Jul 08, Ian Jackson wrote:
> > > Surely the problem is just that the backend isn't going back to the
> > > operational state.  I don't see why this would need the hotplug script
> > > to run again.
> > 
> > Something needs to reconnect the device to the bridge. There is also
> > that hotplug-status thing, which netback reads. I have to check what it
> > does with that.
> 
> Why is the device removed from the bridge ?  What does that ?

Looks like netback does that, because the interface disappears.
Before "disable":

# brctl show
bridge name     bridge id               STP enabled     interfaces
br0             8000.00265523e546       no              eth0
                                                        vif1.0
                                                        vif1.0-emu
After "disable":
# brctl show
bridge name     bridge id               STP enabled     interfaces
br0             8000.00265523e546       no              eth0
                                                        vif1.0-emu

dmesg has:
[50367.178364] br0: port 2(vif1.0) entering forwarding state
[50367.178510] device vif1.0 left promiscuous mode
[50367.178516] br0: port 2(vif1.0) entering disabled state
[50367.227599] frontend_changed: backend/vif/1/0: prepare for reconnect

The last message appears when the frontend is in XenbusStateInitialising and
the backend is in XenbusStateClosed, then the backend changes to
XenbusStateInitWait.

It looks like the backend goes back into XenbusStateConnected when I write
/local/domain/0/backend/vif/1/0/hotplug-status connected, but nothing puts
vif1.0 back into br0.


Olaf