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 3738EC6369E for ; Thu, 3 Dec 2020 02:41:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C732522203 for ; Thu, 3 Dec 2020 02:41:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727375AbgLCClC (ORCPT ); Wed, 2 Dec 2020 21:41:02 -0500 Received: from mout.gmx.net ([212.227.15.19]:32775 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727315AbgLCClB (ORCPT ); Wed, 2 Dec 2020 21:41:01 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1606963165; bh=SP/6IED8LmWASJfQYw9PAH/XnAYv8keg+qUPYC7GwpE=; h=X-UI-Sender-Class:Subject:To:References:From:Date:In-Reply-To; b=cRbuplnjdGJUroswbhh5KCKaH7bwEwZLKWBoskGBDLe2fekIjmQt30+Fu4nQo69ep HVroUN8TKbKbkOk0Dq1GmVgyKi5tOc1PQblphT064ZQylAkrHndlZQH05jBG9wE/TD 6CvZvwvlPKHwkFNP/8dxTahJ7vtbFkBtjyG0N6Es= 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 1MiacH-1kHvTf3FpP-00fiWy; Thu, 03 Dec 2020 03:39:25 +0100 Subject: Re: [PATCH v3 16/54] btrfs: do proper error handling in record_reloc_root_in_trans To: Josef Bacik , linux-btrfs@vger.kernel.org, kernel-team@fb.com References: 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 10:39:21 +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: Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="CSOx0JFt5JEUzitkV7hguVq0noYUSIwfk" X-Provags-ID: V03:K1:0JJiLdvH6c0YmMlyDHlrCKh08a25CuRDYagzsC6Op2F9c7mEG8s wUlMLICF+lv7IO4jp2RR3H9cmwHv0knr8wUq8RyRYLRRvXHneaO54Ddo+RnWPTyoc6g+PdZ MPHpxOs2ynSND51b1QnDSYudwUG0JtxSKnPifgZ3z/sgCFhey+kZRmqA5l0d0AXbBIGGCuf rX8TOCZe8gWVpYAjyW9qg== X-UI-Out-Filterresults: notjunk:1;V03:K0:5vTvH5F2kew=:rl/XHppTXJRlRMGxlGZrNp TFm9rccbsHv6kevjrfTmITnZVAdcpSY5lUg8axFIS7P6rB2PC8LjEIYm+ZCAuI+z801qJAtXd FSmeMbPl6b/ihSdS+PQDp3cdDn6r+KWttd6E+Sm2OqpLuXzLV+Mw5ro05zHh+/hQcDNP7NhzB lrQGIVQCii1ZmAjUPMBhRSK7g6Ge0kSlFmcsVTqqtvf+N8NwKDrOG0y89Z61EAgeGsWgVgqSx cw5rxAd5QUIZn/A95hj0i2nLEDLx6Kg+Thq2UO/9tBWC/ayIyBottrcsNz5PJDclvAsX5NXn8 HC3Xzpm9nKeUu6YphZYyIhXUwHbINLxiHG4oMwCpxzYxPlZZCXeYpLi4CaxRys5wiAlXeg1+c u6gfSL3GoX9zrPCG+T3lkE+FsdHQLgxGG/r7rk864Oy7E2CL/SdVd/XFBfPdq09iRDv6xjy2x nULMhtW4Khh3BkmwnBkcYQBEdcYZPjKwe5rKvwIyk7mNCVNtb6XJMDMrATmzfNmvIXHgSPv6U SFjgUcru9pg94gtQWtIa2Y26xPWw9SAM5lkCFBazfv+GbGuuVA3uN/bngxNy15ZEvMJtiIzgU jRqWrGBy/d4oKUgwElvUgfP4AtREJkMIIvF3porK5+8GdazOkpTrzou/H8FcnS/hCDZDf+lbq ElIOoWsmOkm/ZnAiRZEmBDvals0cJLAVX32Ne/mrrQekktMifKopQAZEBMOmcQEFCpskwRH3a v+4KNdgP5DJfDHnUt3jisAsqnxtBhMWY2KDYJBLTJ/QY6tGEC7+QFZdQKkJ8OktIINIBDVDzZ VwgB7Lsx0nlw4gJsPtwCxSBnmw1tKW1vlfhMPKndJrsm5k3Bhj08CVhnY0nLQGiXvh3V+mLgv TvT0UbqHsBLf5d/JRN9g== Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --CSOx0JFt5JEUzitkV7hguVq0noYUSIwfk Content-Type: multipart/mixed; boundary="uloQj5DbPchvZzPNxdVtpl8PknHzGHlza" --uloQj5DbPchvZzPNxdVtpl8PknHzGHlza 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: > Generally speaking this shouldn't ever fail, the corresponding fs root > for the reloc root will already be in memory, so we won't get -ENOMEM > here. >=20 > However if there is no corresponding root for the reloc root then we > could get -ENOMEM when we try to allocate it or we could get -ENOENT > when we look it up and see that it doesn't exist. >=20 > Convert these BUG_ON()'s into ASSERT()'s + proper error handling for th= e > case of corruption. >=20 > Signed-off-by: Josef Bacik > --- > fs/btrfs/relocation.c | 26 ++++++++++++++++++++++++-- > 1 file changed, 24 insertions(+), 2 deletions(-) >=20 > diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c > index d663d8fc085d..5a4b44857522 100644 > --- a/fs/btrfs/relocation.c > +++ b/fs/btrfs/relocation.c > @@ -1973,8 +1973,30 @@ static int record_reloc_root_in_trans(struct btr= fs_trans_handle *trans, > return 0; > =20 > root =3D btrfs_get_fs_root(fs_info, reloc_root->root_key.offset, fals= e); > - BUG_ON(IS_ERR(root)); > - BUG_ON(root->reloc_root !=3D reloc_root); > + > + /* > + * This should succeed, since we can't have a reloc root without havi= ng > + * already looked up the actual root and created the reloc root for t= his > + * root. > + * > + * However if there's some sort of corruption where we have a ref to = a > + * reloc root without a corresponding root this could return -ENOENT.= > + * > + * The ASSERT()'s are to catch this case in testing, because it could= > + * indicate a bug, but for non-developers it indicates corruption and= we > + * should error out. The same mention of ASSERT() now looks really overkilled. > + */ > + ASSERT(!IS_ERR(root)); > + ASSERT(root->reloc_root =3D=3D reloc_root); > + if (IS_ERR(root)) > + return PTR_ERR(root); > + if (root->reloc_root !=3D reloc_root) { ASSERT(0) would be easier to read here IMHO. Despite that looks good to me. Thanks, Qu > + btrfs_err(fs_info, > + "root %llu has two reloc roots associated with it", > + reloc_root->root_key.offset); > + btrfs_put_root(root); > + return -EUCLEAN; > + } > ret =3D btrfs_record_root_in_trans(trans, root); > btrfs_put_root(root); > =20 >=20 --uloQj5DbPchvZzPNxdVtpl8PknHzGHlza-- --CSOx0JFt5JEUzitkV7hguVq0noYUSIwfk Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEELd9y5aWlW6idqkLhwj2R86El/qgFAl/IT9kACgkQwj2R86El /qgrSwgAl0TLGZS4cC+XAXci+e5cTIUSNf/1298g9CHA47bCH2ndRedc3zgjwTbE vLJ4IC5nIyzk7wdMntynsh6MtXSn6HzCnJPmal1I2i6NXpyrHKAkWwaxLslTUBiT CPl1GnvcPWyHO1QqCdjabVmjsUjGOCejNrcjCsDigvwqS1mSuKqvkXlZ8a9z7FxG AYeWcu8ZFmSOtw9xIP2hB5NvPWhMSOyaRlCnjN5eQ8IF3C8lWLczSEKwCZ/NORqH nEiezUp7WxMltaCGgcsuInIG/P4LT/N8L2g2fclTi1Mu0+105jWzFD5CTb8YoBa1 g3t52dyYfHxaLGpz84WvaexXULB8mw== =cLt5 -----END PGP SIGNATURE----- --CSOx0JFt5JEUzitkV7hguVq0noYUSIwfk--