mlx5e throwing RTNL_ASSERT error on vxlan_get_rx_port

mlx5e throwing RTNL_ASSERT error on vxlan_get_rx_port

[Alexander Duyck]

>From what I can tell it looks like the recent commit that changed the
behavior for vxlan_get_rx_port has broken the mlx5 driver as it was
calling vxlan_get_rx_port in mlx5e_create_netdev which didn't hold the
rtnl lock.  As a result it is throwing RTNL_ASSERT errors.

I'm not sure if anyone has already seen this or not but I thought I
would bring it to your attention.  Odds are this probably something
that needs to be fixed in the mlx5e driver and if I have time I might
get to it sometime in the next several days if nobody else ends up
addressing it.

Thanks.

- Alex

Re: mlx5e throwing RTNL_ASSERT error on vxlan_get_rx_port

[Saeed Mahameed]

On Fri, Apr 22, 2016 at 10:30 PM, Alexander Duyck
<alexander.duyck@gmail.com> wrote:
> From what I can tell it looks like the recent commit that changed the
> behavior for vxlan_get_rx_port has broken the mlx5 driver as it was
> calling vxlan_get_rx_port in mlx5e_create_netdev which didn't hold the
> rtnl lock.  As a result it is throwing RTNL_ASSERT errors.
>

Nice catch Alex.

> I'm not sure if anyone has already seen this or not but I thought I
> would bring it to your attention.  Odds are this probably something
> that needs to be fixed in the mlx5e driver and if I have time I might
> get to it sometime in the next several days if nobody else ends up
> addressing it.
>

Matt will handle it, he is already preparing two fixes in mlx5 vxlan
area, one is to address the kconfig issue Arnd reported and the other
is to address the scheduling while atomic in mlx5e_vxlan_add ndo
implementation which can sleep, from vxlan module it is called under
rcu_read_lock.

Thanks,
Saeed

Re: mlx5e throwing RTNL_ASSERT error on vxlan_get_rx_port

[Hannes Frederic Sowa]

Hello,

On 22.04.2016 22:02, Saeed Mahameed wrote:
> On Fri, Apr 22, 2016 at 10:30 PM, Alexander Duyck
> <alexander.duyck@gmail.com> wrote:
>> From what I can tell it looks like the recent commit that changed the
>> behavior for vxlan_get_rx_port has broken the mlx5 driver as it was
>> calling vxlan_get_rx_port in mlx5e_create_netdev which didn't hold the
>> rtnl lock.  As a result it is throwing RTNL_ASSERT errors.
>>
> 
> Nice catch Alex.
> 
>> I'm not sure if anyone has already seen this or not but I thought I
>> would bring it to your attention.  Odds are this probably something
>> that needs to be fixed in the mlx5e driver and if I have time I might
>> get to it sometime in the next several days if nobody else ends up
>> addressing it.
>>
> 
> Matt will handle it, he is already preparing two fixes in mlx5 vxlan
> area, one is to address the kconfig issue Arnd reported and the other
> is to address the scheduling while atomic in mlx5e_vxlan_add ndo
> implementation which can sleep, from vxlan module it is called under
> rcu_read_lock.

Hm, I probably overlooked something during review or this change in
vxlan_get_rx_port or something came in during the time I was pushing
those changes at the same time. I just had a look and the fix shouldn't
be that hard.

Thanks,
Hannes