On Thu, 18 Aug 2005 16:40:36 -0500
Ryan Harper <ryanh@xxxxxxxxxx> wrote:
> I've encountered several oops when adding and removing interfaces from
> bridges while using Xen. Most of the details are available here.
> The short of it is the following sequence:
Doesn't the mutex in RTNL work right? or are you calling
routines with out asserting it?
> CPU0 CPU1
> add_del_if() unregister_netdevice()
> br_del_if() notifier_call_chain(NETDEV_UNREGISTER)
> br_stp_disable_port() // port->state == BR_STATE_DISABLED
> br_device_event() // dev->br_port != NULL yet
> // event is NETDEV_UNREGISTER
> This sequence doesn't happen all of the time. In many cases, CPU0 moves
> along right into destroy_nbp() which sets dev->br_port = NULL, and
> be_device_event check (p == NULL) hits and a second br_del_if() isn't
> The attached patch is a workaround for the double case, but I'm not sure
> if is the right way to deal with this issue, or if it any issue at all.
> 1. http://bugzilla.xensource.com/bugzilla/show_bug.cgi?id=90