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,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 A18DCC4361A for ; Fri, 4 Dec 2020 08:06:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4DF0122573 for ; Fri, 4 Dec 2020 08:06:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728827AbgLDIGX (ORCPT ); Fri, 4 Dec 2020 03:06:23 -0500 Received: from mout.gmx.net ([212.227.17.22]:58793 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726669AbgLDIGX (ORCPT ); Fri, 4 Dec 2020 03:06:23 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1607069087; bh=NuTkFQXu+8OtBGrs1YStnbJ8In6451ZW9xySq1+zPug=; h=X-UI-Sender-Class:Subject:To:References:From:Date:In-Reply-To; b=lRvT10o+gL835tHjTpMSWscahunt9CXAWFglzMsPEwrcZmuF7X309rsCBTCbOxWSW TH61Aa0muCaI+MgrAdM8KPyn84W6ZmidhH87z3qVfBybinAO4AqmXssPeEwhYI1GCl xiHQElAY+ZsW7kZkT2zoikcKu+sBLdmdDb0xZtbs= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([149.28.201.231]) by mail.gmx.com (mrgmx104 [212.227.17.174]) with ESMTPSA (Nemesis) id 1M5QJJ-1klutX4BKX-001SJH; Fri, 04 Dec 2020 09:04:47 +0100 Subject: Re: [PATCH v4 15/53] btrfs: convert BUG_ON()'s in select_reloc_root() to proper errors To: Josef Bacik , linux-btrfs@vger.kernel.org, kernel-team@fb.com References: <6f12922c8edd64c9df4b09068a1ac15159523d3a.1607019557.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: <8b9ddc7e-2b75-9bc3-5bbd-b9691903b9c3@gmx.com> Date: Fri, 4 Dec 2020 16:04:44 +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: <6f12922c8edd64c9df4b09068a1ac15159523d3a.1607019557.git.josef@toxicpanda.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="Sa25ZEhiL4m4bHt0vhf57KpCOz9Cp5sLh" X-Provags-ID: V03:K1:LlhqtZ0VaHz6B/KLNn+rVutAklLaqonqUwh6WPv/edbMAuzL5mn 2jm0iyE/7qEyGpxue1t4Pwj1qomLyjUpvpNo/zQClWvLPSZQJFnQXaDp46/7bStFltBk2CY vstKHlQUWbziMzV1lNLiBycphONBJCMmdq4sbUFRjZU3cwV/fwwxcfMiQVECemYpHBtUHIE 3ifiRUiC5fSp+7OOysT8Q== X-UI-Out-Filterresults: notjunk:1;V03:K0:2dQbTxZABLw=:KMI+obtb31jrKZ0X00t+Kf m6QO1Jy29reVjiuoKvc53OVTTU2nPD60ZNPwIJZVEGOlVYFsNF7i9ehzT0XdtIbCxAylM/eTh HuzR8g5lbn2x4Hx4s5KGMxRf37S4Uj0daNd1zZeY3WI5Aiu6rxFDTMnhh/xXC+gLcRi2TbXVh GoUts895kxoIQtumHRzk/czCmXE3nGbzRhpUDvViNPxgDgTrRrIrAvdUI4DwRddLZXwgBLjbr +KyjjRy7AZbIRHVlMfrVBUuKybaeM8MSzD5KfyhqMVIv3K5gGWQdrBH9U/tbTrrHvfS6NHeID B4h4Bb9xCjZ91/8sSZksfnzrg2v28FfXbXOdbDas2l6PPLMRysx2tEZaH56UHY5gkBTDb02rT NuUQuz7Yp1o4b1jn0DME3Ca0Yv/NS04Dq2BKa2h7iy1CrcexeXjY+0BAx+ZUqOL009WUoRRPU nSwhTj9dmJ4zUBGHlMTg/zJOVjUHIkNzpU0mSRHcPpf9kpMBaOrkxMXBjSVyZbeDjsbWasBBS yRUMInTXUmyY4lJSli639ozXvViZhoD9HhMZeOVkImnWr3iBv1OAhqi7yNCpYnPv1J9nr/ACB v5KIX1XFxgdhxs+aqiSboAkH4m4SkRH9FjrNaeOaR0iFsHQkdeDa+n+m+yNg+L6IE2LxJ8Xoh S/OvlYz6NPHEjmXDF+g2ckebe+vcNjThjgKVzDeFLV98w2z4BniGWHnhg10czKtVimwWSOedT SZz+LqDOU5MY5yPLGZI8+8MSZ4BVpQz3vYc2QickxNvXQkMrDyV6/TVO597pIHAS6g7kbPfM9 xvU8vbXvJC8AUHSIw4GCiqmWbzNdt1OV6Uw91RLVqnR3QiauCgGhwy52LUTdr4fxV4eewUdDP /axJgExe7HjiILsdXFog== Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --Sa25ZEhiL4m4bHt0vhf57KpCOz9Cp5sLh Content-Type: multipart/mixed; boundary="N7TLBTIVW7PjNLUHxpZinWuk1vRuFXkhF" --N7TLBTIVW7PjNLUHxpZinWuk1vRuFXkhF Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 2020/12/4 =E4=B8=8A=E5=8D=882:22, Josef Bacik wrote: > We have several BUG_ON()'s in select_reloc_root() that can be tripped i= f > you have extent tree corruption. Convert these to ASSERT()'s, because > if we hit it during testing it really is bad, or could indicate a > problem with the backref walking code. >=20 > However if users hit these problems it generally indicates corruption, > I've hit a few machines in the fleet that trip over these with clearly > corrupted extent trees, so be nice and spit out an error message and > return an error instead of bringing the whole box down. >=20 > Signed-off-by: Josef Bacik Reviewed-by: Qu Wenruo Thanks, Qu > --- > fs/btrfs/relocation.c | 47 +++++++++++++++++++++++++++++++++++++++----= > 1 file changed, 43 insertions(+), 4 deletions(-) >=20 > diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c > index 66515ccc04fe..05b80b9ab1e1 100644 > --- a/fs/btrfs/relocation.c > +++ b/fs/btrfs/relocation.c > @@ -1996,8 +1996,33 @@ struct btrfs_root *select_reloc_root(struct btrf= s_trans_handle *trans, > cond_resched(); > next =3D walk_up_backref(next, edges, &index); > root =3D next->root; > - BUG_ON(!root); > - BUG_ON(!test_bit(BTRFS_ROOT_SHAREABLE, &root->state)); > + > + /* > + * If there is no root, then our references for this block are > + * incomplete, as we should be able to walk all the way up to a > + * block that is owned by a root. > + * > + * This path is only for SHAREABLE roots, so if we come upon a > + * non-SHAREABLE root then we have backrefs that resolve > + * improperly. > + * > + * Both of these cases indicate file system corruption, or a bug > + * in the backref walking code. > + */ > + if (!root) { > + ASSERT(0); > + btrfs_err(trans->fs_info, > + "bytenr %llu doesn't have a backref path ending in a root", > + node->bytenr); > + return ERR_PTR(-EUCLEAN); > + } > + if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) { > + ASSERT(0); > + btrfs_err(trans->fs_info, > +"bytenr %llu has multiple refs with one ending in a non shareable root= ", > + node->bytenr); > + return ERR_PTR(-EUCLEAN); > + } > =20 > if (root->root_key.objectid =3D=3D BTRFS_TREE_RELOC_OBJECTID) { > record_reloc_root_in_trans(trans, root); > @@ -2008,8 +2033,22 @@ struct btrfs_root *select_reloc_root(struct btrf= s_trans_handle *trans, > root =3D root->reloc_root; > =20 > if (next->new_bytenr !=3D root->node->start) { > - BUG_ON(next->new_bytenr); > - BUG_ON(!list_empty(&next->list)); > + /* > + * We just created the reloc root, so we shouldn't have > + * ->new_bytenr set and this shouldn't be in the changed > + * list. If it is then we have multiple roots pointing > + * at the same bytenr which indicates corruption, or > + * we've made a mistake in the backref walking code. > + */ > + ASSERT(next->new_bytenr =3D=3D 0); > + ASSERT(list_empty(&next->list)); > + if (next->new_bytenr || !list_empty(&next->list)) { > + btrfs_err(trans->fs_info, > +"bytenr %llu possibly has multiple roots pointing at the same bytenr %= llu", > + node->bytenr, next->bytenr); > + return ERR_PTR(-EUCLEAN); > + } > + > next->new_bytenr =3D root->node->start; > btrfs_put_root(next->root); > next->root =3D btrfs_grab_root(root); >=20 --N7TLBTIVW7PjNLUHxpZinWuk1vRuFXkhF-- --Sa25ZEhiL4m4bHt0vhf57KpCOz9Cp5sLh Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEELd9y5aWlW6idqkLhwj2R86El/qgFAl/J7ZwACgkQwj2R86El /qiXlQf7B7tSEN9/QcllKCPVByv4aRAy/pxa745ai025p1YXkovgG+ebzLJ7UdwA j5ncTfGfXobm7IPp0gJ7s2rCDOQwXpL95SZiF+d0tL1FzPkrVbY2AGti6G7rU0aI 4npkgUoqLvYcvsLq0I3jeDNC1ANAZLikwo3zW8A+gHPruVijZjrYQIhE5tZ+IEJE fnJD3h7B1DFaciB5n5DPr/eDtL4ZrgmfEu43JFbeN1cDtMCG1s/cAagMYQH7l1t3 bXn9Mw8iWNbRuwA0BGBGNmRshZ4xPvkgDJxXDi4tyihBmKsJ2pPgUkI+WTY4db9l bkrB2N9A7awazdE+nSnAta3vPHu4Jg== =WTaq -----END PGP SIGNATURE----- --Sa25ZEhiL4m4bHt0vhf57KpCOz9Cp5sLh--