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[34.48.33.21]) by smtp.gmail.com with UTF8SMTPSA id 00721157ae682-7943b2b9bfcsm49990507b3.38.2026.01.26.08.49.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 26 Jan 2026 08:49:26 -0800 (PST) Date: Mon, 26 Jan 2026 11:49:26 -0500 From: Willem de Bruijn To: Jibin Zhang , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Neal Cardwell , Kuniyuki Iwashima , David Ahern , Matthias Brugger , AngeloGioacchino Del Regno , bpf@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, steffen.klassert@secunet.com Cc: wsd_upstream@mediatek.com, Jibin Zhang Message-ID: In-Reply-To: <20260126152114.1211-1-jibin.zhang@mediatek.com> References: <20260126152114.1211-1-jibin.zhang@mediatek.com> Subject: Re: [PATCH v4] net: fix segmentation of forwarding fraglist GRO Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit [PATCH net v4] Jibin Zhang wrote: > This patch enhances GSO segment handling by properly checking > the SKB_GSO_DODGY flag for frag_list GSO packets, addressing > low throughput issues observed when a station accesses IPv4 > servers via hotspots with an IPv6-only upstream interface. > > Specifically, it fixes a bug in GSO segmentation when forwarding > GRO packets containing a frag_list. The function skb_segment_list > cannot correctly process GRO skbs that have been converted by XLAT, > since XLAT only translates the header of the head skb. Consequently, > skbs in the frag_list may remain untranslated, resulting in protocol > inconsistencies and reduced throughput. > > To address this, the patch explicitly sets the SKB_GSO_DODGY flag > for GSO packets in XLAT's IPv4/IPv6 protocol translation helpers > (bpf_skb_proto_4_to_6 and bpf_skb_proto_6_to_4). This marks GSO > packets as potentially modified after protocol translation. As a > result, GSO segmentation will avoid using skb_segment_list and > instead falls back to skb_segment for packets with the SKB_GSO_DODGY > flag. This ensures that only safe and fully translated frag_list > packets are processed by skb_segment_list, resolving protocol > inconsistencies and improving throughput when forwarding GRO packets > converted by XLAT. Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.") Cc: stable@vger.kernel.org