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=-12.3 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,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 69D8BC07E96 for ; Thu, 15 Jul 2021 08:13:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 540A461106 for ; Thu, 15 Jul 2021 08:13:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240529AbhGOIQV (ORCPT ); Thu, 15 Jul 2021 04:16:21 -0400 Received: from mout.gmx.net ([212.227.17.21]:56711 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234408AbhGOIQU (ORCPT ); Thu, 15 Jul 2021 04:16:20 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1626336804; bh=4gskJI/LX3XGmnr5QK8PP3ShwEGMJndl6Y/nd9GlhJQ=; h=X-UI-Sender-Class:Subject:To:Cc:References:From:Date:In-Reply-To; b=kg7X/N62krtZy4X52JB9v76713svLpzgJukeHH8XorL9WuPUOi0xnzwrEb7COeKzZ 6NCeAGZbTTIiY3as20e+GNV601UYqNTfgC2zUP+LkgjWS+mjAFo9wpmb/p9Cw3qy9T sfitgLJpsTyZlKXexX4sinpQ90v3qXNrdScv2IO4= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([149.28.201.231]) by mail.gmx.net (mrgmx104 [212.227.17.174]) with ESMTPSA (Nemesis) id 1MHoNC-1lxrwz2aqU-00Ex7c; Thu, 15 Jul 2021 10:13:24 +0200 Subject: Re: [PATCH v3] btrfs: rescue: allow ibadroots to skip bad extent tree when reading block group items To: Su Yue , Qu Wenruo Cc: linux-btrfs@vger.kernel.org, Zhenyu Wu References: <20210715050036.30369-1-wqu@suse.com> From: Qu Wenruo Message-ID: Date: Thu, 15 Jul 2021 16:13:20 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.12.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:TPXBoQ53porCNXS2bHxiUOdUf0iU7koFaC/5zUxAg4HmIxnlTyP /IF5l8whqg3Fo7boo3BYbEHdONpTx7195m+3REH0DxHqsf4zX2c/zAuvGW7uzXf741q8p4V C3ieJJKlKfhw9BzoJBa+z03SkkXE3sqZD+SeOQkW1bRH8l1yi73mKEPgk2Juc8xVTavskJA Z37FvYL3u6vrExIyjQejw== X-UI-Out-Filterresults: notjunk:1;V03:K0:frJBhAouIzk=:4KV6yIHRrSuU+0xU9j11+A GxBRx3+l1xJEN/td6AAKL1J7Gtk8wyvt1g6cNyZUhdWyJsTkS5uDACeiFjr68jeftMR+7fcav +MVkEwVv6XmP3qY1UB1uel81zwde7mIgZA3e8xJfaHX1s3gFt6HKWu7wCZmPdxbIgD5hh7twN qiqO+UTvHKdChHrodbWBYgrduBz/hI50MYfD+qjFoYL92Tz6n+dALp7PmyaUMvQGTg+6Nsf+T nKl6jUlnq2kh97ufejtmSoPMZgf2kR5ZHSMC+77IlnsEdLcAW85k9LJGKDz4mij+EdmSk1XfH yKdQssDMRqrjbOj1MvGiWs6ympqCYH7tOMVKcFVnsS3YyJrOs1Gh8NIJBOVVwrZxtPzBHRKwi 2LdUOmJMKgmNO6pQM+5CUXISXhDbWVHF0hgKXMj+b+JwJtAEQaABqCMzW9dGYbiM5cEb1NAbs V4SlxzGTnmqTxVnsXKYiPYtmcsFGjaE1IxFURn4NVu/9I07wofPrLzNo0MWBKSmNymSCzyYX6 G5ynhHgLwt9CPwPAJVWTxn+CjGSSCVjo+L12a26rqR4RGzbTBk5VDaBiC+S/4euLDTE7Rcvt1 Klc5RKGK6TXNIPHPd9051A5MxDIRqi0cLyV3DAM9igkBCWcNjXpfILSljAkSH4+Ll3BEW1JVr sTvt3zzzOtZih93gG0tLyMjZDu7VsMnIYtX1jRXSSeOokyX18y3J8TfCsYCy14sgauK9MHTjA 8QhJd3O0m/CaAB3MnLa0Gcx73lsQVBddBtiLSlAMK2jfBjvmHo5+xd3NeIV6v0iMV9nzdnjDv KzTbndxDf69LCioZNTPffwfa61ccgOByvBctTDAEY9Jv2uXPvn2hxodRAJ1IH+1z3MGi4CwJF E7ppX9N/c8iVPqi1s1rp/M8MLyVZFHllsINqL5Fs9bkj2LvC/4Icb5ujqsnHuN+Zut3slHkjd Xs6hovk9iuMdiOkEDTYEQf8p0rcLcFj6RoLdYA+Awcj524P9vjwZejZ3S1TP734n3iNsORNkk DPDbclZaYoeuH1Gq+lZsZkNIlO4vj8LOdE3SbdNcB7+i9ndIfRntZfdaNJe/WYWqk9w4AYZIc lrw1v6HLvy4ml/fhr1rw7OJzh96GqQMJJh2n+XUVFZ0oM/iJcZpfAdNbw== Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 2021/7/15 =E4=B8=8B=E5=8D=883:50, Su Yue wrote: > > On Thu 15 Jul 2021 at 13:00, Qu Wenruo wrote: > >> When extent tree gets corrupted, normally it's not extent tree root, bu= t >> one toasted tree leaf/node. >> >> In that case, rescue=3Dibadroots mount option won't help as it can only >> handle the extent tree root corruption. >> >> This patch will enhance the behavior by: >> >> - Allow fill_dummy_bgs() to ignore -EEXIST error >> >> =C2=A0 This means we may have some block group items read from disk, = =C2=A0 but >> =C2=A0 then hit some error halfway. >> >> - Fallback to fill_dummy_bgs() if any error gets hit in >> =C2=A0 btrfs_read_block_groups() >> >> =C2=A0 Of course, this still needs rescue=3Dibadroots mount option. >> >> With that, rescue=3Dibadroots can handle extent tree corruption more >> gracefully and allow a better recover chance. >> >> Reported-by: Zhenyu Wu >> Link: https://www.spinics.net/lists/linux-btrfs/msg114424.html >> Signed-off-by: Qu Wenruo >> --- >> Changelog: >> v2: >> - Don't try to fill with dummy block groups when we hit ENOMEM >> v3: >> - Remove a dead condition >> =C2=A0 The empty fs_info->extent_root case has already been handled. >> --- >> =C2=A0fs/btrfs/block-group.c | 15 ++++++++++++++- >> =C2=A01 file changed, 14 insertions(+), 1 deletion(-) >> >> diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c >> index 5bd76a45037e..9bc68515bc4a 100644 >> --- a/fs/btrfs/block-group.c >> +++ b/fs/btrfs/block-group.c >> @@ -2105,11 +2105,16 @@ static int fill_dummy_bgs(struct btrfs_fs_info >> *fs_info) >> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 bg->used =3D em->len; >> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 bg->flags =3D map->typ= e; >> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 ret =3D btrfs_add_bloc= k_group_cache(fs_info, bg); >> -=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 if (ret) { >> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 /* >> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 * We may have some bl= ock groups filled already, thus ignore >> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 * the -EEXIST error. >> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 */ >> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 if (ret && ret !=3D -EEXIST= ) { >> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0 btrfs_remove_free_space_cache(bg); >> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0 btrfs_put_block_group(bg); >> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0 break; >> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 } >> > So we continue to link_block_group() bellow even -EEXIST. The new > allocated bg will be inserted into &space_info->block_groups[index]. > Then while calling close_ctree(), it only frees bgs not allocated by > fill_dummy_bgs(). The bgs still exist in > &space_info->block_groups[index]. Memory leaks! Right, when -EEXIST is hit, we should skip to next chunk, not continuing the remaining works. Thanks, Qu > > -- > Su > >> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 ret =3D 0; >> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 btrfs_update_space_inf= o(fs_info, bg->flags, em->len, =C2=A0em->len, >> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2= =A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 0, 0, &space_info); >> =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 bg->space_info =3D spa= ce_info; >> @@ -2212,6 +2217,14 @@ int btrfs_read_block_groups(struct >> btrfs_fs_info *info) >> =C2=A0=C2=A0=C2=A0=C2=A0 ret =3D check_chunk_block_group_mappings(info)= ; >> =C2=A0error: >> =C2=A0=C2=A0=C2=A0=C2=A0 btrfs_free_path(path); >> +=C2=A0=C2=A0=C2=A0 /* >> +=C2=A0=C2=A0=C2=A0=C2=A0 * We hit some error reading the extent tree, = and have >> rescue=3Dibadroots >> +=C2=A0=C2=A0=C2=A0=C2=A0 * mount option. >> +=C2=A0=C2=A0=C2=A0=C2=A0 * Try to fill using dummy block groups so tha= t the user can >> continue >> +=C2=A0=C2=A0=C2=A0=C2=A0 * to mount and grab their data. >> +=C2=A0=C2=A0=C2=A0=C2=A0 */ >> +=C2=A0=C2=A0=C2=A0 if (ret && btrfs_test_opt(info, IGNOREBADROOTS)) >> +=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 ret =3D fill_dummy_bgs(info= ); >> =C2=A0=C2=A0=C2=A0=C2=A0 return ret; >> =C2=A0}