Re: [PATCH] xen-netfront: Fix hang on device removal

From: Juergen Gross
Date: Wed Feb 28 2018 - 14:21:48 EST


On 28/02/18 13:23, Jason Andryuk wrote:
> A toolstack may delete the vif frontend and backend xenstore entries
> while xen-netfront is in the removal code path. In that case, the
> checks for xenbus_read_driver_state would return XenbusStateUnknown, and
> xennet_remove would hang indefinitely. This hang prevents system
> shutdown.
>
> xennet_remove must be able to handle XenbusStateUnknown, and
> netback_changed must also wake up the wake_queue for that state as well.
>
> Fixes: 5b5971df3bc2 ("xen-netfront: remove warning when unloading module")
>
> Signed-off-by: Jason Andryuk <jandryuk@xxxxxxxxx>
> Cc: Eduardo Otubo <otubo@xxxxxxxxxx>

Committed to xen/tip for-linus-4.16a


Juergen