Re: tunnels: Don't apply GRO to multiple layers of encapsulation.

Re: tunnels: Don't apply GRO to multiple layers of encapsulation.

[joe.korty]

[ resend due to mail problems at my end ]

Hi Jesse,

The backport of fac8e0f579695a3ecbc4d3cac369139d7f819971,
"tunnels: Don't apply GRO to multiple layers of encapsulation",
to linux-4.1.y seems to have missed a line.

The 4.1 commit is 066b300e5be43cb61697539e2a3a9aac5afb422f.

The potentially missing line is:

-               .gro_receive    = ipv6_gro_receive,
+               .gro_receive    = sit_gro_receive,


I am not experiencing any bad symptoms.  I simply noticed
that the patch introduced a new function, sit_gro_receive,
without introducing any users, and that same patch in  
linux-4.4.y does have a user.

Regards,
Joe

Re: tunnels: Don't apply GRO to multiple layers of encapsulation.

[Jesse Gross]

On Thu, Aug 31, 2017 at 6:58 AM,  <joe.korty@concurrent-rt.com> wrote:
> [ resend due to mail problems at my end ]
>
> Hi Jesse,
>
> The backport of fac8e0f579695a3ecbc4d3cac369139d7f819971,
> "tunnels: Don't apply GRO to multiple layers of encapsulation",
> to linux-4.1.y seems to have missed a line.
>
> The 4.1 commit is 066b300e5be43cb61697539e2a3a9aac5afb422f.
>
> The potentially missing line is:
>
> -               .gro_receive    = ipv6_gro_receive,
> +               .gro_receive    = sit_gro_receive,
>
>
> I am not experiencing any bad symptoms.  I simply noticed
> that the patch introduced a new function, sit_gro_receive,
> without introducing any users, and that same patch in
> linux-4.4.y does have a user.

Thanks for pointing that out. The line you mentioned should indeed be
there and seems to have been missed in the backport.

The backport was actually done by Sasha, not by me - would you mind
sending a patch to him or working with him to fix it?

Re: tunnels: Don't apply GRO to multiple layers of encapsulation.

[joe.korty]

Hi Sasha,
The backport of

   fac8e0f579695a3ecbc4d3cac369139d7f819971
   tunnels: Don't apply GRO to multiple layers of encapsulation

into 4.1 missed a hunk.  The same backport into 3.18 was done
correctly.  This patch introduces the missing hunk into 4.1.
Excepts from some emails:

Joe Korty wrote:
> I am not experiencing any bad symptoms.  I simply noticed
> that the patch introduced a new function, sit_gro_receive,
> without introducing any users, and that same patch in
> linux-4.4.y does have a user.

Jesse gross wrote:
> Thanks for pointing that out. The line you mentioned
> should indeed be there and seems to have been missed in
> the backport.
> 
> The backport was actually done by Sasha, not by me -
> would you mind sending a patch to him or working with him
> to fix it?

Could you review this and run it through your tests and
send it along to Greg if appropriate?

Thanks,
Joe

Signed-off-by: Joe Korty <joe.korty@concurrent-rt.com>

Index: b/net/ipv6/ip6_offload.c
===================================================================
--- a/net/ipv6/ip6_offload.c
+++ b/net/ipv6/ip6_offload.c
@@ -300,7 +300,7 @@ static struct packet_offload ipv6_packet
 	.type = cpu_to_be16(ETH_P_IPV6),
 	.callbacks = {
 		.gso_segment = ipv6_gso_segment,
-		.gro_receive = ipv6_gro_receive,
+		.gro_receive = sit_gro_receive,
 		.gro_complete = ipv6_gro_complete,
 	},
 };