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=-2.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 2071CC3A5A2 for ; Tue, 3 Sep 2019 14:24:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DD8382077B for ; Tue, 3 Sep 2019 14:24:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=gmx.net header.i=@gmx.net header.b="k3/zBYcu" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729533AbfICOYe (ORCPT ); Tue, 3 Sep 2019 10:24:34 -0400 Received: from mout.gmx.net ([212.227.15.18]:53573 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727005AbfICOYd (ORCPT ); Tue, 3 Sep 2019 10:24:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1567520670; bh=BAAM1wemEGh68n3MKw13DBo1eA1Ix5beu8S4K9A20ss=; h=X-UI-Sender-Class:Subject:To:References:From:Date:In-Reply-To; b=k3/zBYcuP1M+MEX+B6dx9LBkCXpo6SqYkUmhN6kEqCG1xzGYCo/F9sc4aT4qbIk5B BPORcOdK7JrFL1lu/qngASG9AXsvO/B/Njbyi+PCznUpeVKCF5WBUO/WXN+DBSXH3D GXhbX2rLjxIX7c0iUfNxrg8QamIxgJsLGAdfCViY= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [0.0.0.0] ([13.231.109.76]) by mail.gmx.com (mrgmx001 [212.227.17.184]) with ESMTPSA (Nemesis) id 0M8NBi-1iQead1WxG-00vvNK; Tue, 03 Sep 2019 16:24:30 +0200 Subject: Re: btrfs and checksum To: Jorge Fernandez Monteagudo , "linux-btrfs@vger.kernel.org" References: From: Qu Wenruo Openpgp: preference=signencrypt Autocrypt: addr=quwenruo.btrfs@gmx.com; prefer-encrypt=mutual; keydata= mQENBFnVga8BCACyhFP3ExcTIuB73jDIBA/vSoYcTyysFQzPvez64TUSCv1SgXEByR7fju3o 8RfaWuHCnkkea5luuTZMqfgTXrun2dqNVYDNOV6RIVrc4YuG20yhC1epnV55fJCThqij0MRL 1NxPKXIlEdHvN0Kov3CtWA+R1iNN0RCeVun7rmOrrjBK573aWC5sgP7YsBOLK79H3tmUtz6b 9Imuj0ZyEsa76Xg9PX9Hn2myKj1hfWGS+5og9Va4hrwQC8ipjXik6NKR5GDV+hOZkktU81G5 gkQtGB9jOAYRs86QG/b7PtIlbd3+pppT0gaS+wvwMs8cuNG+Pu6KO1oC4jgdseFLu7NpABEB AAG0IlF1IFdlbnJ1byA8cXV3ZW5ydW8uYnRyZnNAZ214LmNvbT6JAVQEEwEIAD4CGwMFCwkI BwIGFQgJCgsCBBYCAwECHgECF4AWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCWdWCnQUJCWYC bgAKCRDCPZHzoSX+qAR8B/94VAsSNygx1C6dhb1u1Wp1Jr/lfO7QIOK/nf1PF0VpYjTQ2au8 ihf/RApTna31sVjBx3jzlmpy+lDoPdXwbI3Czx1PwDbdhAAjdRbvBmwM6cUWyqD+zjVm4RTG rFTPi3E7828YJ71Vpda2qghOYdnC45xCcjmHh8FwReLzsV2A6FtXsvd87bq6Iw2axOHVUax2 FGSbardMsHrya1dC2jF2R6n0uxaIc1bWGweYsq0LXvLcvjWH+zDgzYCUB0cfb+6Ib/ipSCYp 3i8BevMsTs62MOBmKz7til6Zdz0kkqDdSNOq8LgWGLOwUTqBh71+lqN2XBpTDu1eLZaNbxSI ilaVuQENBFnVga8BCACqU+th4Esy/c8BnvliFAjAfpzhI1wH76FD1MJPmAhA3DnX5JDORcga CbPEwhLj1xlwTgpeT+QfDmGJ5B5BlrrQFZVE1fChEjiJvyiSAO4yQPkrPVYTI7Xj34FnscPj /IrRUUka68MlHxPtFnAHr25VIuOS41lmYKYNwPNLRz9Ik6DmeTG3WJO2BQRNvXA0pXrJH1fN GSsRb+pKEKHKtL1803x71zQxCwLh+zLP1iXHVM5j8gX9zqupigQR/Cel2XPS44zWcDW8r7B0 q1eW4Jrv0x19p4P923voqn+joIAostyNTUjCeSrUdKth9jcdlam9X2DziA/DHDFfS5eq4fEv ABEBAAGJATwEGAEIACYWIQQt33LlpaVbqJ2qQuHCPZHzoSX+qAUCWdWBrwIbDAUJA8JnAAAK CRDCPZHzoSX+qA3xB/4zS8zYh3Cbm3FllKz7+RKBw/ETBibFSKedQkbJzRlZhBc+XRwF61mi f0SXSdqKMbM1a98fEg8H5kV6GTo62BzvynVrf/FyT+zWbIVEuuZttMk2gWLIvbmWNyrQnzPl mnjK4AEvZGIt1pk+3+N/CMEfAZH5Aqnp0PaoytRZ/1vtMXNgMxlfNnb96giC3KMR6U0E+siA 4V7biIoyNoaN33t8m5FwEwd2FQDG9dAXWhG13zcm9gnk63BN3wyCQR+X5+jsfBaS4dvNzvQv h8Uq/YGjCoV1ofKYh3WKMY8avjq25nlrhzD/Nto9jHp8niwr21K//pXVA81R2qaXqGbql+zo Message-ID: <3930ddc8-f4e9-1db4-dc6a-d8945cda0e10@gmx.com> Date: Tue, 3 Sep 2019 22:24:25 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="eZlStbhfZgzqTxyrIwc9BT5c8HOjkgMns" X-Provags-ID: V03:K1:/UrsnNHeWs3LXGVz6mKOJnp77XEkUNAKTFCiiWVbLIJfuxw301E jVVCOB8abz+LtRUJtYtL459KsVZOYYf/ngtS6jnJ54pDB0MmSD/HMxXptgALbXZCz5lqB17 RwuoR0wVTWj6a0yL9UADbM+oiajpK1WayGQYVcux8GGq8G/4Nv4ounsbP0ASM6h9Nma4ums KS74yUrD1OvCcsLDKkldw== X-UI-Out-Filterresults: notjunk:1;V03:K0:DZdRnwk7ljU=:SDU8+oWFqVMY/TILs3iCtQ fXbJDDSo5VjB4Ftxt3HaW11EVlEO2icmrLEf/y6Vlne8FXWNV9TPefWwrOnVauwNfjWsMI7OH haJvDIQhwEGVFeuOr9tKLOdU6GgBAs4SToWRBbQznxHDeoRmYOtkb2bX6FFbV6lMeLerpLwGJ qBVS3olPAGU40Dx1nHcaqBWdc4rPdA5XGHG5gZ0VtFXCRadqHpY6xXuP+tJp9SaU6oq6xvt08 NjCQxfqFl0kummdBQkkB0B1Q7E1b6KVE+kcJwWaKa894J1j8KsMoare421dDg0+FYwEvOJgnA E+J/rpB9vOyMU7bJeM3uPWePwP5p1EchsqYLjjy7UcL6ZXVPVjNVAG30M6m2AYLud/f0eZSX7 M1+YCnCQ5KyUUVLjtBPj2+Pc5Bh1metnmyxDEw10JLHxfR3T5dcsLkoS2vXV7jp+wCMYq1Xay /92+iqQEj2OHMCwY7NeAf6WxUBrQKsn5RhkqlSauDCTouN46JxBnvmAkqecJjDrXpneCU0oJa XTtTYbx/ZtjNDLhWfFl2QDyyF1QrIKeMRpWZpOK5cngM1vGUBD6rVpwMKTi1JBikdPpN1tp2H ywRV35/Xn0nqJ7hh8+eaKG4e6+nHFy7zKcRWVwj0ctT0lJ/kh8Obcbkgs4o3RYaSnErHbcXPY cgYiFckfuTOxwiJrHbungS2UcY0RzO4jbv8KWoprIgsXbDy0j9Va4qDYs2h+z8FZlI6HVB1nC Zwg4k5SgwIcbFTDrvbTzEB47IUFsGyO0AMGQpGAT3sztKORwfMbLSXnMQt0AX9tWOoOhvVx5R mJDq+UKI3UVqjHdW4GvOnl2u4Zj0zTYibuCrHROYTLtTYsTuNOgnwi++JFgweGvnzj0L6yuJ8 /nYSM7Ep3HEEY1Lw5FSb0bW3aAtsuJVIyn/m1ugZpsInX59YmRVVoWrHcqKUX5MjuOxcDhCv9 I60YJOVIZzBO4eqZHpnIGJZLbR4xI7GZa7vVPZ7ZSX7XnmNoizAb5BFPk/w6qWjKAJxp/0zUc w/lo6x+4BvJz2QAs+c1IB1d0Hd0ByiMhOX9B1sFcjs/ZrfHZkvJ1VmqBDB2i2UiUx51yQkMOG ye1qJx+sdhN8gIluE4RImGDDylRSESiI1gTmIoyKYFrs5jpM0hWlyNp4A/qebUM7ZUBN1xN5W +M1p7oSMj9+AYljhC9HWJ4oja6mURR7O4nHWgHPbFwM9oOwPg5ricPvyRwTwb1Fx2jMEEMy2F 4G3kvGy4EvKUDgQr9 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --eZlStbhfZgzqTxyrIwc9BT5c8HOjkgMns Content-Type: multipart/mixed; boundary="QMQpIBV1zVGCVA9og8kvX22cIttmKtvGl"; protected-headers="v1" From: Qu Wenruo To: Jorge Fernandez Monteagudo , "linux-btrfs@vger.kernel.org" Message-ID: <3930ddc8-f4e9-1db4-dc6a-d8945cda0e10@gmx.com> Subject: Re: btrfs and checksum References: In-Reply-To: --QMQpIBV1zVGCVA9og8kvX22cIttmKtvGl Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 2019/9/3 =E4=B8=8B=E5=8D=889:50, Jorge Fernandez Monteagudo wrote: > Hi all, >=20 > This is my first message in this list. I'm looking for advice because I= have a weird silent data corruption and maybe with btrfs and the checksu= m capability this could be, at least, notified to the system, and detecte= d using some btrfs-utils tool or dmesg. >=20 > Imagine you have an SSD with an EXT4 partition in READ ONLY mode and in= side several files. RO of the ext4, and still get corruption? Definitely looks like a hardware problem to me. > Every file is an ISO filesystem crypted with cryptsetup. Then first, th= e EXT4 partition in mounted then every file is mounted using losetup and = crytpsetup. We have found, sometimes reading a PNG or WAV file from any o= f the ISO filesystems mounted, we get an error because the data is incorr= ect. Flushing caches and trying again don't solve the error. Maybe we hav= e a faulty disk controller and changing the filesystem could be useful, o= r a RAM with some error... For btrfs, as long as you're using data csum (default), btrfs can detect such corruption. For v5.2 kernel, btrfs can even detects some easy to expose memory corruption. But please keep in mind that, due to the fact btrfs (at least least version) is very picky about corrupted on-disk data or memory, if you find something wrong, you need to check dmesg to see what's going wrong. Furthermore, if your ssd is not reliable, especially when it lies about FLUSH/FUA, btrfs can be easier to be corrupted, as btrfs completely relies on FLUSH/FUA and metadata COW to ensure its safety against powerloss, it's way easier to get corrupted if FLUSH/FUA is not implemented corrected. (On the other hand, btrfs is more robust against data corruption, so as long as your SSD is OK, you may find a better experience using btrfs) Thanks, Qu >=20 > Changing the EXT4 to btrfs is enough to enable the checksum property or= we have to change every ISO file to btrfs to enable the checksum? >=20 > Thanks! > Jorge >=20 --QMQpIBV1zVGCVA9og8kvX22cIttmKtvGl-- --eZlStbhfZgzqTxyrIwc9BT5c8HOjkgMns Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQEzBAEBCAAdFiEELd9y5aWlW6idqkLhwj2R86El/qgFAl1ud5kACgkQwj2R86El /qhJTgf9H0bSAO4DizmQcbCITRP92F1i4JV4MW57nxjizTU2XDMULTmbgIc+aD+e 51RBRbFzka5ble2YQPz3QdyAsfrKRU4CQAT8Bt7h/vxCVfW34WeWE68WjLQD/opQ AU13PqkX/8rmDOoTvf7MF6KPUGqJO6TGgmf1/WObOSQjDruhyU9Fq5dRA8HjB+l7 czUqHSxInh3NOxP76Kj2/khSAFzaXTPPsjjGlYfsraO7nGUStODBX9ga18t4mv/T HPLxdRX45Be3LfuOkQLjnIXuMlacNuxuk/nSNwdInJDEmTWOUzN/R2FfZj9b3P0+ dwaetqehydNOWnECSk+8E2MoNCwk/w== =Po4V -----END PGP SIGNATURE----- --eZlStbhfZgzqTxyrIwc9BT5c8HOjkgMns--