Re: [PATCH net] ice: Fix race condition during interface enslave

[Tony Nguyen]

On 3/10/2022 1:59 PM, Jakub Kicinski wrote:
> On Thu, 10 Mar 2022 18:16:41 +0100 Ivan Vecera wrote:
> > Commit 5dbbbd01cbba83 ("ice: Avoid RTNL lock when re-creating
> > auxiliary device") changes a process of re-creation of aux device
> > so ice_plug_aux_dev() is called from ice_service_task() context.
> > This unfortunately opens a race window that can result in dead-lock
> > when interface has left LAG and immediately enters LAG again.
> >
> > Reproducer:
> > ```
> > #!/bin/sh
> >
> > ip link add lag0 type bond mode 1 miimon 100
> > ip link set lag0
> >
> > for n in {1..10}; do
> >          echo Cycle: $n
> >          ip link set ens7f0 master lag0
> >          sleep 1
> >          ip link set ens7f0 nomaster
> > done
> What's the priority on this one? The loop max of 10 seems a little
> worrying.
>
> Tony, Jesse, is it important enough to push into 5.17 or do you prefer
> to take it via the normal path and do full QA? The blamed patch come
> in to 5.17-rc it seems.

Hi Jakub,

Yea, it'd be preferred to make it into 5.17. Feel free to take it directly.

Thanks,

Tony