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 48983C6369E for ; Thu, 3 Dec 2020 02:25:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DFED621D91 for ; Thu, 3 Dec 2020 02:25:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729466AbgLCCZ2 (ORCPT ); Wed, 2 Dec 2020 21:25:28 -0500 Received: from mout.gmx.net ([212.227.15.18]:45155 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727774AbgLCCZ1 (ORCPT ); Wed, 2 Dec 2020 21:25:27 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1606962232; bh=FdH57odpug8bXpgL7sdwGPw/5NzxFWEwLc05MePe6L0=; h=X-UI-Sender-Class:Subject:To:References:From:Date:In-Reply-To; b=YuLplsP58GirRylw+G+yuqu/R5fAyqEuVnRzq37TF3bRcNSd1m7T0Hxebdr3ar/7P zgo38Jx9OmHc7wUqW4x/QqPeuKnBpNvr4txxB0rFpK4zRB6OVk3bplSKMUc1PlNUTw XPScy6qGr6em19j33J6p2Retrl6vSscq0ycjzdSg= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([149.28.201.231]) by mail.gmx.com (mrgmx004 [212.227.17.184]) with ESMTPSA (Nemesis) id 1MUGi9-1kcdwS3Yax-00RIHd; Thu, 03 Dec 2020 03:23:52 +0100 Subject: Re: [PATCH v3 13/54] btrfs: handle errors from select_reloc_root() To: Josef Bacik , linux-btrfs@vger.kernel.org, kernel-team@fb.com References: <871fea9cea530b626f0f253c00d53a3e7a1ea531.1606938211.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: <811a4ef0-72a4-c1d3-566a-60c09cda53ef@gmx.com> Date: Thu, 3 Dec 2020 10:23:48 +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: <871fea9cea530b626f0f253c00d53a3e7a1ea531.1606938211.git.josef@toxicpanda.com> Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="hEq4Wy2qqo2DY7l8i8EcBiEXn9FwkjYHy" X-Provags-ID: V03:K1:Jub9OlOHV9HGWylf6s8YMzxtttG3DfOq8JGCJy2b7vUe9PSqzUt eCnebRCWGa5udFnwYkW2LnSjPTTMMl6Ke7xy2iYDiJVOsQni8XDtNh8jTnyePhTVTBuuDqR TgqJklAWQH5VEXoDAznoqwTRTmar0txHfxOO2QV8bEc0nHcq4ribf3UcYYFpllvIhAXWsBa BSjf4PxPhEN9aQYApiljg== X-UI-Out-Filterresults: notjunk:1;V03:K0:EgI0kx4I0yY=:giNYgdk5TNfmiVoS/2KDWQ XxK/b8+QKAQTJqH6XIeN05WGZs5uUU29Ys5ub3R2CEqcQkICE7XIZn6pACI2dPXj7Y/JExzzp 6CMvLfyJei8MurN/E5kehPRWIPr/jYmGQqy/kBwneEknr2d9+nlGY0WvQpzApUmUpCx1ibwta quSNUcfDnI/P8tAfMdumyvL714pFoD+mwaVd4zf5pmPNvvMG4oZHOAaqZ/4FD1FtVQNWgff+q 36sTJsC4tihf02GhFxEhBMN0ofSAMAphsY1pIGQdjMwJNZKcuGJrg6AR0TzVdcQmP36QoOYW2 OMtulIqqINzL/4uz0Aoqy/dPiRZO6pXu7TQAGzt+jTJ0+TFtO3Jm7bkPYP2xHDSkfuvF49Uss KQa8zourkzWOdTuiT+up3URNsFsIKmJ9JpvmOKP1q9uEfwR7WVQnYvwTfAKqTQJ6AtjK5HWWD WovydmYieyzV/P5m6PFRjVgp3mLYMq0eYPzhyUd88sLaHSOxBRJMmS2i55v+Ge5bzWCxuyp5S vhkgTgRsWdbhSsTi0IaULzHtGG62DTw0hWIHwQSYEwcat3zf4h5NC5Fjs77RdCidNAdpo7oem ssVEcs/tclfvwxAkLu9sEDMMImm3WYokZkCij8ibwCHGdwy+eWa0iZlwwEAm4lSRthE8T7anY NDLSmFy9/eqzcdSbcm3XjpHLyXJ4/DYYIxIApwODxa3QTu1f9k2v/q4F3Pqrw3sNy3ywrVcAA qK6kWlz5pKie+n/JH4m+QUe1ziCXcUjlX+MtDE39K7hqoALAA5u4sytgsdWGyxSU444NGBqaF oGXo2FhqNRo9eZ71w0a6nSrXna5X+mdBFU98663e08LtObbH/OV1OtHrGD+xUwkw9VrJ+oGCC KL75AuJK88XgR+Eg78Pw== Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --hEq4Wy2qqo2DY7l8i8EcBiEXn9FwkjYHy Content-Type: multipart/mixed; boundary="iWA52XQp1nJd3BOFUTTpjxHc3hZJJtRX2" --iWA52XQp1nJd3BOFUTTpjxHc3hZJJtRX2 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=883:50, Josef Bacik wrote: > Currently select_reloc_root() doesn't return an error, but followup > patches will make it possible for it to return an error. We do have > proper error recovery in do_relocation however, so handle the > possibility of select_reloc_root() having an error properly instead of > BUG_ON(!root). I've also adjusted select_reloc_root() to return > ERR_PTR(-ENOENT) if we don't find a root, instead of NULL, to make the > error case easier to deal with. I've replaced the BUG_ON(!root) with a= n > ASSERT(ret !=3D -ENOENT), as this indicates we messed up the backref > walking code, but could indicate corruption so we do not want to have a= > BUG_ON() here. >=20 > Signed-off-by: Josef Bacik Reviewed-by: Qu Wenruo Thanks, Qu > --- > fs/btrfs/relocation.c | 15 +++++++++++++-- > 1 file changed, 13 insertions(+), 2 deletions(-) >=20 > diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c > index 4333ee329290..66515ccc04fe 100644 > --- a/fs/btrfs/relocation.c > +++ b/fs/btrfs/relocation.c > @@ -2027,7 +2027,7 @@ struct btrfs_root *select_reloc_root(struct btrfs= _trans_handle *trans, > break; > } > if (!root) > - return NULL; > + return ERR_PTR(-ENOENT); > =20 > next =3D node; > /* setup backref node path for btrfs_reloc_cow_block */ > @@ -2198,7 +2198,18 @@ static int do_relocation(struct btrfs_trans_hand= le *trans, > =20 > upper =3D edge->node[UPPER]; > root =3D select_reloc_root(trans, rc, upper, edges); > - BUG_ON(!root); > + if (IS_ERR(root)) { > + ret =3D PTR_ERR(root); > + > + /* > + * This can happen if there's fs corruption, but if we > + * have ASSERT()'s on then we're developers and we > + * likely made a logic mistake in the backref code, so > + * check for this error condition. > + */ > + ASSERT(ret !=3D -ENOENT); > + goto next; > + } > =20 > if (upper->eb && !upper->locked) { > if (!lowest) { >=20 --iWA52XQp1nJd3BOFUTTpjxHc3hZJJtRX2-- --hEq4Wy2qqo2DY7l8i8EcBiEXn9FwkjYHy Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEELd9y5aWlW6idqkLhwj2R86El/qgFAl/ITDQACgkQwj2R86El /qgpPAgApGybEksHTQcFOydywdLsx24+ugxDrKUj9c3dFi93Y4ARvvZFc6QA0738 aLJpv4S+B383tdYgBo9IhtjKqNPPHV7/8Mj4DhdeufMrblvLGS480OVPtCDZL1Ms ynNSdDsZ1shzM1rwDW3CDNfm/vJmhxXJaj99aOchL4SmkRZwTn/WhYGNpDM/O1a7 hyvSIODuRpV1eiXbpID4AuQa4jpVIYnykNdqhY+Md6phbDLObrj/oPeKFcgVdWMo 1Yl6Iz6lV7gJIn24VAbkggf+6ccrUWREBYZFD7p5DU/HuU50J104FHK8pCG7BVfN p18QXyUG0KIHsgCsBd6DfuTasfR9wg== =A9Bf -----END PGP SIGNATURE----- --hEq4Wy2qqo2DY7l8i8EcBiEXn9FwkjYHy--