From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from smtp-16.italiaonline.it ([212.48.25.144]:48682 "EHLO libero.it" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753885AbcKZXQl (ORCPT ); Sat, 26 Nov 2016 18:16:41 -0500 Reply-To: kreijack@inwind.it Subject: Re: [PATCH] btrfs: raid56: Use correct stolen pages to calculate P/Q References: <20161121085016.7148-1-quwenruo@cn.fujitsu.com> <94606bda-dab0-e7c9-7fc6-1af9069b64fc@inwind.it> <20161125043119.GG8685@hungrycats.org> <20161126185402.GK8685@hungrycats.org> To: Zygo Blaxell Cc: Qu Wenruo , linux-btrfs@vger.kernel.org From: Goffredo Baroncelli Message-ID: <59e0b1c7-51a9-ede4-6571-fa0b20394145@inwind.it> Date: Sun, 27 Nov 2016 00:16:34 +0100 MIME-Version: 1.0 In-Reply-To: <20161126185402.GK8685@hungrycats.org> Content-Type: text/plain; charset=windows-1252 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 2016-11-26 19:54, Zygo Blaxell wrote: > On Sat, Nov 26, 2016 at 02:12:56PM +0100, Goffredo Baroncelli wrote: >> On 2016-11-25 05:31, Zygo Blaxell wrote: [...] >> >> BTW Btrfs in RAID1 mode corrects the data even in the read case. So > > Have you tested this? I think you'll find that it doesn't. Yes I tested it; and it does the rebuild automatically. I corrupted a disk of mirror, then I read the related file. The log says: [ 59.287748] BTRFS warning (device vdb): csum failed ino 257 off 0 csum 12813760 expected csum 3114703128 [ 59.291542] BTRFS warning (device vdb): csum failed ino 257 off 0 csum 12813760 expected csum 3114703128 [ 59.294950] BTRFS info (device vdb): read error corrected: ino 257 off 0 (dev /dev/vdb sector 2154496) ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ IIRC In case of RAID5/6 the last line is missing. However in both the case the data returned is good; but in RAID1 the data is corrected also on the disk. Where you read that the data is not rebuild automatically ? In fact I was surprised that RAID5/6 behaves differently.... > >> I am still convinced that is the RAID5/6 behavior "strange". >> >> BR >> G.Baroncelli >> -- >> gpg @keyserver.linux.it: Goffredo Baroncelli >> Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5 >> -- gpg @keyserver.linux.it: Goffredo Baroncelli Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5