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=-12.2 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,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 475B0C63777 for ; Thu, 3 Dec 2020 05:42:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E4F02206A4 for ; Thu, 3 Dec 2020 05:42:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726491AbgLCFma (ORCPT ); Thu, 3 Dec 2020 00:42:30 -0500 Received: from mout.gmx.net ([212.227.15.18]:52005 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725872AbgLCFm3 (ORCPT ); Thu, 3 Dec 2020 00:42:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1606974054; bh=Xh7L/lLXZoUsPSVBKx/efU/vaxt8BSH4cGY5nepQ8R4=; h=X-UI-Sender-Class:Subject:To:References:From:Date:In-Reply-To; b=OeFA+b+h6n0miqOimLd8D8kk3nM0tVXnqrNG9LhDTB+xZn2Iq8e+KvJ3bJ1OzYIkK 4AqaoWEt3pObK7QMjT08NIEh0FkQ2s2ogmSR1mLaA4KkpZVGeHcCyLG34Tlv2u0XgO 0GBhzFKgp6LWTdKkSOoibcfMcXFDWqLKNjNk1nV0= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([149.28.201.231]) by mail.gmx.com (mrgmx005 [212.227.17.184]) with ESMTPSA (Nemesis) id 1M1Ycr-1kjJWA3pHv-0034KN; Thu, 03 Dec 2020 06:40:54 +0100 Subject: Re: [PATCH v3 48/54] btrfs: handle extent corruption with select_one_root properly To: Josef Bacik , linux-btrfs@vger.kernel.org, kernel-team@fb.com References: <6570c4cd1433a02a9d84e6fcd93f9a971d7f42fd.1606938211.git.josef@toxicpanda.com> 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: Date: Thu, 3 Dec 2020 13:40:49 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.12.0 MIME-Version: 1.0 In-Reply-To: <6570c4cd1433a02a9d84e6fcd93f9a971d7f42fd.1606938211.git.josef@toxicpanda.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="3pdgsYZPgPBb2ZE3ABpTu61GjVqi5nyIc" X-Provags-ID: V03:K1:2ISiCW0R2cVbuuKgA/scj34nouOC2AssqSb39G8VD/TBcNToVRa uIFRiX91NmQPpJN0QYp1jNNin+30ki3taBRboe5YCx9v8NF8K79X7zLt4YL8CJjEUjCAMGN AB+U/ih12GD8SWQSINb7/qUGTqZOh10ISlvY+OuCpjyovVqOrPi8VTfqqUxyWj+YlJ7Vq6i zinMYr4lIP8dUuUPJaB2g== X-UI-Out-Filterresults: notjunk:1;V03:K0:7fEKDEPNgD0=:ZhneuJplPtwTdqVkjwGz+f LQFT9uCFJzDQpuhysrvm6vtPuSEcP/vX4ziQkDbc7iUX1U2g76ucezzWNL4fiCr6rK8uCM/Ed 8s063YXqh9tPXW/4MHVdgc26wOLEvK6G+uyfN1PwSLFDp3cQEYMxmoikZJ92xAEuvIlhorJgL S8sbdnmjPBiXSYKln39lH0X82rs8yMtOMzhAG4HGr/96OHfgh55kbFeZEnLgGOCt5UUB23HOO 9pf8SyA/YFYBDua8vI4CxYg3YxhRwypjN9Qie4P9WlnMOG9wwXBToSJGct5ptZ1biRgofsumV 81oFZXQvwDqb4kKlLW22HMF7gRtKtY+PJs0hAe3LeOEXg5NF5CWMQBjRg+RfoUdrO8hrYzizN Cl032bOma/4qEKZKiSyRy4FTwNHtqDeG7ZlpWLv0puU7Xumx5csWs+W0pIW5AhYf9iawDcDAa R/U1bVDEOzxNun9oixnJaQRuBfK/w0Vr8E6nY3fT37coJI1H4IzG25PTwom+6A3D1EWkk0+sx tq4zB85CIPNkjiqh1mRzlDQ1HbpFFNYoFMveB1Z61ovDV7I9x57KKhbsZHeQZLys3VeIx4PMn FSIGbBE8hgsed6USU40mSgPQelLc1KB5dHcFGEkyaQ5rFlPPdGd8IjTmABekXckH3IlaBvZyd +/9NEIHZKoRunJ78CfpLO0+Z73OMyrpzaqZt1CtjhaWpeQ8DCq8HQi7cxUSw1/bADpuy6PLby 4u67jC1qFUDMxFhepj0Nga6vaW2Y0TiEY+Fr67sE3gGaLjANqgs/8czfgmuu+wQ1HyJqWtgGy faPWku20CQDtIBPKpGPedAKrPXzqsgfMtpRP0jtHtbBTk68ad0o53sfM/B+gLjtIsr1sk825E 4R+Nytt+eheT7kIiiES+OQzOeIp95p5s6GRUfVyp8= Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --3pdgsYZPgPBb2ZE3ABpTu61GjVqi5nyIc Content-Type: multipart/mixed; boundary="N6BjLtBGKFAkPycyZJQlwXmJv3jxtuhWa" --N6BjLtBGKFAkPycyZJQlwXmJv3jxtuhWa Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 2020/12/3 =E4=B8=8A=E5=8D=883:51, Josef Bacik wrote: > In corruption cases we could have paths from a block up to no root at > all, and thus we'll BUG_ON(!root) in select_one_root. Handle this by > adding an ASSERT() for developers, and returning an error for normal > users. >=20 > Signed-off-by: Josef Bacik > --- > fs/btrfs/relocation.c | 19 ++++++++++++++++--- > 1 file changed, 16 insertions(+), 3 deletions(-) >=20 > diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c > index d4656a8f507d..91479979d2a7 100644 > --- a/fs/btrfs/relocation.c > +++ b/fs/btrfs/relocation.c > @@ -2200,7 +2200,16 @@ struct btrfs_root *select_one_root(struct btrfs_= backref_node *node) > cond_resched(); > next =3D walk_up_backref(next, edges, &index); > root =3D next->root; > - BUG_ON(!root); > + > + /* > + * This can occur if we have incomplete extent refs leading all > + * the way up a particular path, in this case return -EUCLEAN. > + * However leave as an ASSERT() for developers, because it could > + * indicate a bug in the backref code. > + */ > + ASSERT(root); > + if (!root) > + return ERR_PTR(-EUCLEAN); Just the same comment on using ASSERT(0) in the error branch. Despite that looks OK to me. Thanks, Qu > =20 > /* No other choice for non-shareable tree */ > if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) > @@ -2598,8 +2607,12 @@ static int relocate_tree_block(struct btrfs_tran= s_handle *trans, > =20 > BUG_ON(node->processed); > root =3D select_one_root(node); > - if (root =3D=3D ERR_PTR(-ENOENT)) { > - update_processed_blocks(rc, node); > + if (IS_ERR(root)) { > + ret =3D PTR_ERR(root); > + if (ret =3D=3D -ENOENT) { > + ret =3D 0; > + update_processed_blocks(rc, node); > + } > goto out; > } > =20 >=20 --N6BjLtBGKFAkPycyZJQlwXmJv3jxtuhWa-- --3pdgsYZPgPBb2ZE3ABpTu61GjVqi5nyIc Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEELd9y5aWlW6idqkLhwj2R86El/qgFAl/IemEACgkQwj2R86El /qgt0Af/Vpa8JTSd9FjQSTbG46UhZ/qWhlZAoe4XW7URaEWzosoMpIGaYMhfMp0y aMI/yHphaLaNeu7sA2ZQsewrFoM6fBtVp2JPRR5As+VcN55uXXs8OIBKHrgf9Jd4 N5J5cDjvjYQuZmp2VRnXeQ2SDvYXUyhaYGFbr0GqDiyd2vzpfSy53DUTiPY+r+bh jRRRjrlG9hysoNouYbAE0B4hwSEQ66h1zGpEvGn0J19giaZNaBmuJ1O7NKENy4Fb lWjdfGmO7GUD3BfdDiz+J1OE/obkxHx+te6QTqmka6BLurGy1l7y0OtnxZV7WohI Yl1KRRHo6tMjaqio1JiNeVMYUM8xsQ== =ft3C -----END PGP SIGNATURE----- --3pdgsYZPgPBb2ZE3ABpTu61GjVqi5nyIc--