From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8F122CA9EC2 for ; Tue, 29 Oct 2019 07:09:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 48EB620830 for ; Tue, 29 Oct 2019 07:09:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="lDEsOk+U" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726939AbfJ2HJz (ORCPT ); Tue, 29 Oct 2019 03:09:55 -0400 Received: from mout.gmx.net ([212.227.15.15]:43337 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726222AbfJ2HJz (ORCPT ); Tue, 29 Oct 2019 03:09:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1572332980; bh=E9yS9xiIohHXUUaON2izs3RtZ2M7RuDppHB441rsC0M=; h=X-UI-Sender-Class:Subject:To:Cc:References:From:Date:In-Reply-To; b=lDEsOk+UvJ6Gu5IQs6bPpER6W6jP3RUxbHc3xcES07p8z7QLwjWHE9s6eWeCgQqiF qW1SKPyPzk4AHKnk1pN2TSxJ4spHabRtWKcP3dVvq0zEoPaiX/TIS/WTzKfxtFeBqJ yTUdxb1rCpgCG+/Z380cKjbTHljuoFVcbtpK7kfg= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([13.231.109.76]) by mail.gmx.com (mrgmx005 [212.227.17.184]) with ESMTPSA (Nemesis) id 1N7iCW-1htmJF1wji-014iNM; Tue, 29 Oct 2019 08:09:40 +0100 Subject: Re: [RFC PATCH] btrfs: rescue: Introduce new rescue mount option, rescue=skipdatacsum, to skip data csum verification To: Roman Mamedov , Qu Wenruo Cc: linux-btrfs@vger.kernel.org References: <20191029062149.217995-1-wqu@suse.com> <20191029115317.03b43d94@natsu> From: Qu Wenruo Autocrypt: addr=quwenruo.btrfs@gmx.com; prefer-encrypt=mutual; keydata= mQENBFnVga8BCACyhFP3ExcTIuB73jDIBA/vSoYcTyysFQzPvez64TUSCv1SgXEByR7fju3o 8RfaWuHCnkkea5luuTZMqfgTXrun2dqNVYDNOV6RIVrc4YuG20yhC1epnV55fJCThqij0MRL 1NxPKXIlEdHvN0Kov3CtWA+R1iNN0RCeVun7rmOrrjBK573aWC5sgP7YsBOLK79H3tmUtz6b 9Imuj0ZyEsa76Xg9PX9Hn2myKj1hfWGS+5og9Va4hrwQC8ipjXik6NKR5GDV+hOZkktU81G5 gkQtGB9jOAYRs86QG/b7PtIlbd3+pppT0gaS+wvwMs8cuNG+Pu6KO1oC4jgdseFLu7NpABEB AAG0IlF1IFdlbnJ1byA8cXV3ZW5ydW8uYnRyZnNAZ214LmNvbT6JAU4EEwEIADgCGwMFCwkI BwIGFQgJCgsCBBYCAwECHgECF4AWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCXZw1oQAKCRDC PZHzoSX+qCY6CACd+mWu3okGwRKXju6bou+7VkqCaHTdyXwWFTsr+/0ly5nUdDtT3yEVggPJ 3VP70wjlrxUjNjFb6iIvGYxiPOrop1NGwGYvQktgRhaIhALG6rPoSSAhGNjwGVRw0km0PlIN D29BTj/lYEk+jVM1YL0QLgAE1AI3krihg/lp/fQT53wLhR8YZIF8ETXbClQG1vJ0cllPuEEv efKxRyiTSjB+PsozSvYWhXsPeJ+KKjFen7ebE5reQTPFzSHctCdPnoR/4jSPlnTlnEvLeqcD ZTuKfQe1gWrPeevQzgCtgBF/WjIOeJs41klnYzC3DymuQlmFubss0jShLOW8eSOOWhLRuQEN BFnVga8BCACqU+th4Esy/c8BnvliFAjAfpzhI1wH76FD1MJPmAhA3DnX5JDORcgaCbPEwhLj 1xlwTgpeT+QfDmGJ5B5BlrrQFZVE1fChEjiJvyiSAO4yQPkrPVYTI7Xj34FnscPj/IrRUUka 68MlHxPtFnAHr25VIuOS41lmYKYNwPNLRz9Ik6DmeTG3WJO2BQRNvXA0pXrJH1fNGSsRb+pK EKHKtL1803x71zQxCwLh+zLP1iXHVM5j8gX9zqupigQR/Cel2XPS44zWcDW8r7B0q1eW4Jrv 0x19p4P923voqn+joIAostyNTUjCeSrUdKth9jcdlam9X2DziA/DHDFfS5eq4fEvABEBAAGJ ATwEGAEIACYCGwwWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCXZw1rgUJCWpOfwAKCRDCPZHz oSX+qFcEB/95cs8cM1OQdE/GgOfCGxwgckMeWyzOR7bkAWW0lDVp2hpgJuxBW/gyfmtBnUai fnggx3EE3ev8HTysZU9q0h+TJwwJKGv6sUc8qcTGFDtavnnl+r6xDUY7A6GvXEsSoCEEynby 72byGeSovfq/4AWGNPBG1L61Exl+gbqfvbECP3ziXnob009+z9I4qXodHSYINfAkZkA523JG ap12LndJeLk3gfWNZfXEWyGnuciRGbqESkhIRav8ootsCIops/SqXm0/k+Kcl4gGUO/iD/T5 oagaDh0QtOd8RWSMwLxwn8uIhpH84Q4X1LadJ5NCgGa6xPP5qqRuiC+9gZqbq4Nj Message-ID: <7136fdbf-364e-8b00-c078-fb77b1b9d751@gmx.com> Date: Tue, 29 Oct 2019 15:09:34 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.0 MIME-Version: 1.0 In-Reply-To: <20191029115317.03b43d94@natsu> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="cHty9Egu3BCZwBp1OYTLnvOLE4PPaNJjM" X-Provags-ID: V03:K1:8s+ooiBKcrrmYfVgnvQRlHJ0cuNdI5qLlrEhj1XdvFEWUbXrMR0 wWtJ8gon4UiYC+Q9wWOCaZpfYH/x9Ac6TOyFGIRHbKipcmFM2pF4mmovAXynsnEbxNVT2+O Pke3OlVWQZhsZX4JcXdHvmHWbT40LyZ7qC1yNYlYT11t7icWZhzjMr8fnKHVnxlNIrJ4SIH 635VSqNs/dKdQ9vLoIdjg== X-UI-Out-Filterresults: notjunk:1;V03:K0:MdtTfVBK3zE=:zsQkcG3k+ILspoO9mW1MMw D6Yb8dxr/LeRYVuLLmSUfBVQdyV4xP9xB7EyZPPpFN3Q8HO2ueFgUFSlN/yT4LT5dOQygPE8F qxyOaQvDfMS+wXiOs/59ntjMv3mrSeSlE+3kD5AEUIqqwdeduyshwJAD/1ich5mdU/cwzdjjz sPmQJXoOuvy0WTaaVNlbD67LmJjVZ5oF5AXuGhOKxPsV+56IJc82h3hwHvcoznjIiUnBvNRWM Q4FKzlFGIDa1IhbmDzuIvGG41nbxSuV0fmN2zRDmj/OMcMVvVlRDIngYEAuPWWgHWYcSHHi4a 27VKwEKJQD9FcfyO0nw19BrKQmjXtuhHGlZ7psjB1cYSm781fCt9ZByRF3Zc14BRnWtyY6EZI CaXlpHwRCUcMsx7TmQCn5zOE3oxu7ZQ5Ip+zk6TiyREXCFsG4f6HVB/l8vXHeY5SDCD9rNlGK wPo10nr+o6vw0dPvki4/XlY70CkV2FzOLsVbSPLGBxjEd9PQdRtnv108u3eWAEOIF3aYQ36e5 6w/NdV8LfIEr2exHAtidUJl7x8iXt4/8R1iz+kfjIRV/DbnGqIiqQqOyA63tmVnSKVNG5aSCN V9kwJo0wfHcQ95elaq3vujG+JiHvZDivO2USClorPJT/wWERSBVyjBIXyeU4u33M/OEpKDsVK Oyy4atqOIeLD8lhJOopyal6M73L+5BiFG6OoYiahOwmSqgJvQgbTQl+uRognAG+uZjBbJ29W4 ED9cv7BHyn97LXpLpS1GhOFTwWdFn18l2VTJuhwqABvmmrLy+jaZ6QHHZnPEJDaYHDMa1z7Lw qGUMbItMBJMbOVtwEdmxkaax7+zfBIsowN76ypDVhZulnLGEMlEfAyQc7FJhk9uDDuO1dT+xY ai/yT89/LRj/AMo4gOSiWPLhvAWfte65ZPPL91axi1PleEMAEkCdsmve2wk+FHLLkGKolk7F9 PpUFpn7cVM1a464iITknPShrkGloqwKJfD39P0MBUjXCMTHNGWNM7Gj/XNsTsWxhfD4FCn9tJ 5Ucu9ZAy4tMUJtDJWWGmmSOjTqRrLogqqq4ExTH9cUA2RYY+t+4g5COJsV10CUzBKa5OXlkfF G9F0y+CuzLq/ZW/0NK9R5rhE3Zcsnvd6UiTkwZpc3P9ARdAfzgAI/pz8DwGrs5KX6fYDvMiLL Yy+yXIBEniMXcncLXtmkelEzMLBAzfG+kg4419kAW4t4tNv7/rEauq8M2WBBfnmJ6UfROz+7b UtrUNH1LBVX99Lg0139flGTr582vc1v/0zi8WDGD+6JbOgx+6/13+8P8sfSo= Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --cHty9Egu3BCZwBp1OYTLnvOLE4PPaNJjM Content-Type: multipart/mixed; boundary="qE3BmkCpG93t7Y1pR6quxfiAKsJ2D5cDK" --qE3BmkCpG93t7Y1pR6quxfiAKsJ2D5cDK Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 2019/10/29 =E4=B8=8B=E5=8D=882:53, Roman Mamedov wrote: > On Tue, 29 Oct 2019 14:21:49 +0800 > Qu Wenruo wrote: >=20 >> Here we introduce a new rescue=3D mount option to completely skip data= >> csum check. >> Since data csum check is completely skipped, for profiles with extra >> mirrors/copies, it will return the first copy only, which is not >> optimized, but should be good enough for rescue usage. >> >> This option only affects data csum verification, doesn't affect data >> csum calcuation, so new data write will still be protected by csum (if= >> it doesn't get affected by csum tree corruption). >=20 > Maybe just make the "nodatasum" mount option skip verification of exist= ing > checksums as well? Actually before seeing this patch I believed "nodata= sum" > already does that. Nodatasum only applies to new writes, doesn't affect existing csum verification. Normally nodatasum is just considered as a performance optimization, not something we would like to use for rescue usage. >=20 > Also for consistency note that datasum/nodatasum call it just "sum" in = the > mount option name, not "csum". That makes sense. Thanks, Qu --qE3BmkCpG93t7Y1pR6quxfiAKsJ2D5cDK-- --cHty9Egu3BCZwBp1OYTLnvOLE4PPaNJjM Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEELd9y5aWlW6idqkLhwj2R86El/qgFAl235a4ACgkQwj2R86El /qhREgf/YWRy1FY5CF7mRWHR79R/97ujpEHJu9GK/yqpOehgG2O84VfSe2um2Nps CfzcXPpRoAz+49QJsDZH7xs6Sfd5rsU7dIwzprKfsjxmiqupbJbsn3aItaPDA2nB aDNGJSrTV86yehb3JUWr30tdbz4CqFcypsc50RFQVsbwsYq9+OnbgFF9+SCJnf2+ ZpR48tUsj78LtZPhn02JfDrCeILs9sUr4SdOsjyuymXvk6QfZJbkVBGI0+fISG8R spO+BnK48Ia6CG4/YpomGGopz5G/ptwk60N782bMeCVOCqKwtjGtvNwJ0Bz4qbl+ h20UI95pt2fVtYw4yuykzbRRGLZ8jA== =KLV1 -----END PGP SIGNATURE----- --cHty9Egu3BCZwBp1OYTLnvOLE4PPaNJjM--