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=-8.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham 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 287DFFA372A for ; Wed, 16 Oct 2019 14:18:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DEB4821925 for ; Wed, 16 Oct 2019 14:18:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="FmzWaA5t" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2393913AbfJPOSv (ORCPT ); Wed, 16 Oct 2019 10:18:51 -0400 Received: from mout.gmx.net ([212.227.17.21]:55877 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2393873AbfJPOSu (ORCPT ); Wed, 16 Oct 2019 10:18:50 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1571235522; bh=9ke3fxs+GipSOXrqULujCNcXSf7oMXsvhH4XBUW7xVE=; h=X-UI-Sender-Class:Subject:To:Cc:References:From:Date:In-Reply-To; b=FmzWaA5t2qfOo022jfIsszivnbtoKyGxTyOKeho91riEKqSHsCpkUW2m7+J7gxL4g leL/i6BMrMccEJuiPV2oPBM+XKYBi8ndxcHeRu/76qZWlp+cmS2qNAYm208E+lLSUV x7Fn6m0j7rTPlD1UrZ1KLrTYR/wxDlvMzgcSrMW0= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([13.231.109.76]) by mail.gmx.com (mrgmx104 [212.227.17.174]) with ESMTPSA (Nemesis) id 1M8hZJ-1iOt0K1rof-004loN; Wed, 16 Oct 2019 16:18:42 +0200 Subject: Re: [PATCH] btrfs-progs: warn users about the possible dangers of check --repair To: Johannes Thumshirn , David Sterba Cc: Linux BTRFS Mailinglist , rbrown@suse.de References: <20191016140533.10583-1-jthumshirn@suse.de> 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: <7914adef-b771-694f-af62-e5c4679d8203@gmx.com> Date: Wed, 16 Oct 2019 22:18:35 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: <20191016140533.10583-1-jthumshirn@suse.de> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="Q8QRPoUkJY6kSEWcwjcb0xcuZJIR2LhbF" X-Provags-ID: V03:K1:ZjXHSTfRu+wNfOTQ7sBLHgrt2woDG1PGEBZIkpft722Tp7mB7zj pfP20gU+iawHv0F2hpGC4SV6YLlZ0SiMCAbn4/y+oSwZq/DHtqdX8dFTpzINwWYZrvDTCOY sT3YRaFzVUm+17ZEqlhlqSWterfHJOFzhoJv92fEuo+SOmhjGl1Q0U9DwW8Z+pF4cT6rFSo 8QlRTkkp13ZQuT9I2aKGA== X-UI-Out-Filterresults: notjunk:1;V03:K0:HAOeK5D3ASg=:RWbBfUN8QNOmlUj3Ox5piN kXfugeOb8JGDmzkpgtr081t7pPjqBLm8ohroCx2XPWvK/fqFc99PtIVbgEB7l3hBbMtMZ3QDb OJ/2bmQ0AhMWsMeQyqBM9T4bJJOXZrliK3NHTabF4Yr8Tns/IcHMYrK/L+PK7saXwpQbAZWqh UDnzTHm5l8Qfo3Y3POR1hxiOsHwv3c3nvMI66tba/ba284K+HqjY2Y9R115j9q/IhDsuzbUSG MUIe+Rgw/BFbv8G6aoBgjq97EcBEBdg/RZYDffRjBTAoOi8BdcDX8IKlDWfXEVomyErxRLXCl pgvzLVa+JNGguen9rYeiCn2gkAO9InmE6ZlbxMUzQDPBDIzWHL9HjAsEFqdq1qfDRCzJ/tvSF wVj1/P5ZnB7E+PnZBdaEH4N7/c6FTyBPiGbveAtWoNgX1jY4i2mIr9qIUxLZeRc4Evy1r7QUg VF+oWM2AuvOYyWNQp0IeksmVsJ7R+XSoPoAQmP7PkMQd2u6OCyuPiw4vPIxAQviatXoZoVDjy U+jtNE/rl/e9NKFBk3GfxcXUbso6nESS6yEe5pjlC8cvHH8f/imkXgGmDWXs4AkkYlj2pgsaj OgtonPTlNCa5EdCn8JiKbVCFiaXztPbl9nulSGomMHvfJP4WLQexhVQ0IxJvrnB78wB2GBOjL ClA17VgGli97NiolafcTGbBPKjMmGM0qI9LWldNOjsnjMO5o3f/5Fw8pZNR4EvBXOExdAEw/b zUaxcUNuSq9FiACo39HANWdROYH9b2cyNF1Y0TinsfQ5AjEW8XNpV/0ezbOYac10IjaQ/UebC RIzcaGGRPv1YGMasFgzWq7SugLY1djtFXcfj6EORdkRRrkdXRHL7ynZc/dYEfmjV1P9qDWNXh CW3m8lpgKiiL6tkourgNTXX43zNxVzvEHioYSOkl5JIC9Y07+GFZZe0OBj6PLikaV0zXhYdEC M99cK4KBUXWJsvPa/LjhLef+40SJ4WhBq0TzKXatZwJvPmfseRtevg2B5mAgDxtjNtGUCWr1q gx1XB3b3iJSeHg7IFNLF/xCxHL8uYCLZ39URsC6pnw0TMJVcivM23uK3DwdmMJ5H3GuKh7G1O WCKOaAq6qYPqmjFu4AJMKeDeun3hUF30AJssMFo4N2BplTZGEq0tyDZ5ZDIC2NuSHaw8tU2j+ W/Ny2fDwrjYDPxp6KzzKDaXIowFSZGGlI3k8347GOAbYzkgkVS7NeNMq3IZbD1UoMZtuDa0Qe o4prANR28BIyz/aZkNJ9Q3bZsrT81K4TmEJE1RIMSgVeaChqy8hdgcdybBOk= 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) --Q8QRPoUkJY6kSEWcwjcb0xcuZJIR2LhbF Content-Type: multipart/mixed; boundary="wpxQ0M8dCziO0bSNUYwPOhsLXqQR8nQIQ" --wpxQ0M8dCziO0bSNUYwPOhsLXqQR8nQIQ Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 2019/10/16 =E4=B8=8B=E5=8D=8810:05, Johannes Thumshirn wrote: > The manual page of btrfsck clearly states 'btrfs check --repair' is a > dangerous operation. >=20 > Although this warning is in place users do not read the manual page and= /or > are used to the behaviour of fsck utilities which repair the filesystem= , > and thus potentially cause harm. >=20 > Similar to 'btrfs balance' without any filters, add a warning and a > countdown, so users can bail out before eventual corrupting the filesys= tem > more than it already is. >=20 > Signed-off-by: Johannes Thumshirn > --- > check/main.c | 17 +++++++++++++++++ > 1 file changed, 17 insertions(+) >=20 > diff --git a/check/main.c b/check/main.c > index fd05430c1f51..acded927281a 100644 > --- a/check/main.c > +++ b/check/main.c > @@ -9970,6 +9970,23 @@ static int cmd_check(const struct cmd_struct *cm= d, int argc, char **argv) > exit(1); > } > =20 > + if (repair) { > + int delay =3D 10; Any delay would make the selftest miserably slow. And in fact, recent btrfs check --repair is no longer that dangerous. Sure, it still can't handle everything yet, but at least it's not making things (that) worse. Deadly bugs like the lack of flush/fua is already solved, so I'm not 100% sure if we still need such a big warning. Thanks, Qu > + printf("WARNING:\n\n"); > + printf("\tDo not use --repair unless you are advised to do so by a d= eveloper\n"); > + printf("\tor an experienced user, and then only after having accepte= d that no\n"); > + printf("\tfsck successfully repair all types of filesystem corruptio= n. Eg.\n"); > + printf("\tsome other software or hardware bugs can fatally damage a = volume.\n"); > + printf("\tThe operation will start in %d seconds.\n", delay); > + printf("\tUse Ctrl-C to stop it.\n"); > + while (delay) { > + printf("%2d", delay--); > + fflush(stdout); > + sleep(1); > + } > + printf("\nStarting repair.\n"); > + } > + > /* > * experimental and dangerous > */ >=20 --wpxQ0M8dCziO0bSNUYwPOhsLXqQR8nQIQ-- --Q8QRPoUkJY6kSEWcwjcb0xcuZJIR2LhbF Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEELd9y5aWlW6idqkLhwj2R86El/qgFAl2nJrsACgkQwj2R86El /qgnpAgAmJzMMe6bhvgAfIpQ8IzbgBnQ+sOfs6JfGuR0+1+QyARBvfwM+amglWVo wwz73o9SB4SAsctrsBC5h/Dv3htMcxIUZJWYmRovXUZdv53A0ko7g03rut4LmKSs XCJoHoZfF6z9TE4P04w055yBdbtN+yO76Nyrc24zew5/MJQc0WZHk1+pFoBeMfWL 1azNne54OuW1Usok0Y1iUN1ys6qYlFBYbmIlpGLzu9W5XFCRrDNXwuIPeYKz0zUt J95FKPaIfuFmV9CTIkSfI6ano0QAbC5hFOb1wVL3yrIpkdOO9fFwWyJcmQIh0fZA GX8J+VsuEH5UTu+fAlYh8y+fROOQqA== =Pk9i -----END PGP SIGNATURE----- --Q8QRPoUkJY6kSEWcwjcb0xcuZJIR2LhbF--