From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C965AA28 for ; Tue, 29 Aug 2023 06:50:14 +0000 (UTC) Received: from mail-pg1-x531.google.com (mail-pg1-x531.google.com [IPv6:2607:f8b0:4864:20::531]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 290BC10A for ; Mon, 28 Aug 2023 23:50:13 -0700 (PDT) Received: by mail-pg1-x531.google.com with SMTP id 41be03b00d2f7-565dc391be3so3400892a12.0 for ; Mon, 28 Aug 2023 23:50:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=purestorage.com; s=google2022; t=1693291812; x=1693896612; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=Hj0zcVFcZtB73joYoqKn7u0JrXUadMG4Ol0kcC0MOws=; b=G7vM+ORsSGeTaxZm4gkEkrKjbsOpnSZH5heH7t2yOKxd3MxGmPlGbejiGdvHq2rpr9 Y+YuprTJ0yGdUYjqjPN6vyJFo3cVv3eUxI6B004p4gH5Uw3WZ6uRQeB75ZRCLTwDnRLq hiR+B4yJ7rewOJOlhP33q2FB0U6bR/DRMx2R6Oc90oTXJNzF27box2kr6Jyunx91E89P QuxbYzQRy82+gv/Q2O/roQR2sPPj3Ltv8uJFFDn5iGpUgx68pkXDqECBrz0H9HW3aZyT VptZmJHKWQJeJsTBPqRZjlkoMw9xNW7fQZ/XnN+MPqHtAeziyusFYeK6d6q9ksdQhlcC WwUw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1693291812; x=1693896612; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=Hj0zcVFcZtB73joYoqKn7u0JrXUadMG4Ol0kcC0MOws=; b=ERylmB7bPnp7Sv13q83rFqWIhh6ZBz8do7IrvdUb8X6SDtPx3lfpxL6asU5K71dV4s e4KU0eMeZmrvjehihKba+UPowfZSaapZ17OGOYPkzYfLzRMqYJ7zw8hxorPsm10Q06YU cs3i+t4Z64SC6N5mm8M3iL8HnJyPqmgnWruWfETXDEJglsefyW/Byy2adGGVOvdBI+ZU MIaG7U4sAvhpI3+F1U2QOJTNBKr2HHGhkGBMNCNNvnYPzhw1JtyxlltWVvKh+oX0xNX0 jf7GInnGueGlsC9GF/wQHiPHBAq5SNTiEZXowURafV/dDAyCCyWcJOsz0L8Jh5X66fNM qCaw== X-Gm-Message-State: AOJu0YyakH+XoW6q5ZMozBZOcZTptVUIeGIUVWtlonlQHdXma1ruKZWN Ip5mv0pwVEKgPLSaWAsKcdv1/Q== X-Google-Smtp-Source: AGHT+IG7v6u6J583NScDd5VhvnBr3oBIVYMSHf38YBYeWjzP6/MlK11DhgHCw5e34bWatr8a9yrePg== X-Received: by 2002:a17:90a:1542:b0:26d:609a:74cd with SMTP id y2-20020a17090a154200b0026d609a74cdmr2283335pja.24.1693291812530; Mon, 28 Aug 2023 23:50:12 -0700 (PDT) Received: from medusa.lab.kspace.sh (c-98-207-191-243.hsd1.ca.comcast.net. [98.207.191.243]) by smtp.googlemail.com with ESMTPSA id hi14-20020a17090b30ce00b00264044cca0fsm608631pjb.1.2023.08.28.23.50.11 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Aug 2023 23:50:12 -0700 (PDT) Date: Mon, 28 Aug 2023 23:50:10 -0700 From: Mohamed Khalfella To: willemjdebruijn Cc: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Willem de Bruijn , Alexander Duyck , David Howells , Jesper Dangaard Brouer , Kees Cook , "open list:NETWORKING [GENERAL]" , open list , "open list:BPF [MISC]" Subject: Re: [PATCH] skbuff: skb_segment, Update nfrags after calling zero copy functions Message-ID: <20230829065010.GO4091703@medusa> References: <20230828233210.36532-1-mkhalfella@purestorage.com> <64ed7188a2745_9cf208e1@penguin.notmuch> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <64ed7188a2745_9cf208e1@penguin.notmuch> X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED, SPF_HELO_NONE,T_SPF_PERMERROR autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On 2023-08-28 21:18:16 -0700, willemjdebruijn wrote: > Small point: nfrags is not the only state that needs to be refreshed > after a fags realloc, also frag. I am new to this code. Can you help me understand why frag needs to be updated too? My reading of this code is that frag points to frags array in shared info. As long as shared info pointer remain the same frag pointer should remain valid. Am I missing something? > > Thanks for the report. I'm traveling likely without internet until the > weekend. Apologies if it takes a while for me to follow up. No problem. Thanks for the quick response!