Re: [PATCH v2 net-next] net: skb_vlan_untag(): don't reset transport offset if set by GRO layer

[Jakub Kicinski]

On Mon, 09 Nov 2020 23:47:23 +0000 Alexander Lobakin wrote:
> Similar to commit fda55eca5a33f
> ("net: introduce skb_transport_header_was_set()"), avoid resetting
> transport offsets that were already set by GRO layer. This not only
> mirrors the behavior of __netif_receive_skb_core(), but also makes
> sense when it comes to UDP GSO fraglists forwarding: transport offset
> of such skbs is set only once by GRO receive callback and remains
> untouched and correct up to the xmitting driver in 1:1 case, but
> becomes junk after untagging in ingress VLAN case and breaks UDP
> GSO offload. This does not happen after this change, and all types
> of forwarding of UDP GSO fraglists work as expected.
> 
> Since v1 [1]:
>  - keep the code 1:1 with __netif_receive_skb_core() (Jakub).
> 
> [1] https://lore.kernel.org/netdev/zYurwsZRN7BkqSoikWQLVqHyxz18h4LhHU4NFa2Vw@xxxxxxxxxxxxxxxxxxxx
> 
> Signed-off-by: Alexander Lobakin <alobakin@xxxxx>

Applied, thanks!