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[195.231.44.239]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-482b144173csm4419412f8f.6.2026.08.19.01.50.33 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 19 Aug 2026 01:50:34 -0700 (PDT) Message-ID: Date: Wed, 19 Aug 2026 10:50:33 +0200 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 net] vlan: fix skb_under_panic and races when toggling HW VLAN offload To: Eric Dumazet , xietangxin Cc: "David S . Miller" , Jakub Kicinski , Simon Horman , netdev@vger.kernel.org, eric.dumazet@gmail.com, stable@vger.kernel.org References: <20260811085246.2267779-1-edumazet@google.com> <64a0b57c-040c-4703-95eb-886701bdf745@redhat.com> <492adef9-936e-490d-ba1e-3d026ff1223a@h-partners.com> From: Paolo Abeni Content-Language: en-US In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 8/19/26 10:07 AM, Eric Dumazet wrote: > Regarding the reorder_hdr=off finding from Sashiko: > > 1. reorder_hdr=on is the default for VLAN devices, which continues to use > __vlan_hwaccel_put_tag() and HW VLAN TX insertion offload as before. > > 2. For the rare reorder_hdr=off configuration, the intention of the flag > is specifically to produce inline Ethernet headers, unless I am mistaken. > > Previously, whether reorder_hdr=off generated an inline tag or used HW > offload depended on whether the lower device advertised VLAN offload > at device creation time. > > Using vlan_header_ops unconditionally makes the behavior consistent across > all lower devices without changing the wire format. > > If you prefer, I can send a v4 clarifying this consequence in the commit > description. IMHO it's not needed, it is enough for me that the implications are known and well understood. /P