On Fri, 15 Mar 2019 11:56:01 -0700
Eric Dumazet <eric.duma...@gmail.com> wrote:
> On 03/15/2019 11:02 AM, David Miller wrote:
> > From: Eric Dumazet <eric.duma...@gmail.com>
> > Date: Fri, 15 Mar 2019 09:06:25 -0700
> >
> >>
> >>
> >> On 03/15/2019 08:28 AM, Stefano Brivio wrote:
> >>> On Fri, 15 Mar 2019 23:18:52 +0800
> >>> Zhiqiang Liu <liuzhiqian...@huawei.com> wrote:
> >>>
> >>>> In vxlan_destroy_tunnels func, unregister_netdevice_queue is called after
> >>>> gro_cells_destroy func. However, in unregister_netdevice_queue func, the
> >>>> gro_cells_destroy func will also call the gro_cells_destroy func as the
> >>>> following routine:
> >>>> unregister_netdevice_many() -> rollback_registered_many()
> >>>> -> ndo_uninit() -> gro_cells_destroy()
> >>>>
> >>>> Signed-off-by: Suanming.Mou <mousuanm...@huawei.com>
> >>>> Reviewed-by: Zhiqiang Liu <liuzhiqian...@huawei.com>
> >>>> Reviewed-by: Stefano Brivio <sbri...@redhat.com>
> >>>
> >>> NACK, please read my and Eric's comments to v1 -- giving me more than 23
> >>> minutes to answer would have been a nice touch as well :)
> >>>
> >>
> >> Sorry for the confusion, I forgot to add the question marks to my
> >> sentences.
> >>
> >> In fact, this is a bug fix, that we missed in the previous fix.
> >>
> >> Technically the bug is older.
> >
> > Please elaborate.
> >
>
> Commit ad6c9986bcb62
> ("vxlan: Fix GRO cells race condition between receive and link delete")
>
> fixed a race condition for the typical case a vxlan device is dismantled from
> the
> current netns.
>
> But if a netns is dismantled, we call vxlan_destroy_tunnels()
> to schedule a unregister_netdevice_queue() of all the vxlan tunnels
> that are related to this netns.
Won't that happen via ops_exit_list() only after synchronize_rcu() is
called by cleanup_net(), though? Is there another path I missed?
--
Stefano
