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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B99DAC433EF for ; Tue, 29 Mar 2022 21:06:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233254AbiC2VIX (ORCPT ); Tue, 29 Mar 2022 17:08:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41856 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233120AbiC2VIV (ORCPT ); Tue, 29 Mar 2022 17:08:21 -0400 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.220.28]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 01E1D1890EA for ; Tue, 29 Mar 2022 14:06:36 -0700 (PDT) Received: from relay2.suse.de (relay2.suse.de [149.44.160.134]) by smtp-out1.suse.de (Postfix) with ESMTP id 053E2218FF; Tue, 29 Mar 2022 21:06:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_rsa; t=1648587995; h=from:from:reply-to:reply-to:date:date:message-id:message-id:to:to: cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=vm3ovff6pN64LmLXTllNgbPVeBr42U9C0Yil8UfjHOM=; b=ORWipA0s+D324GxJ+MP4lBpAA2uzh6eil5JuFLrqvwGbhExv7KevlLjRvtLSw9ge5WDpCK ZaH/TaLO3yLzU/UUErAjdxuERMeAqeWX68ETKFdqEn7F2dcHIWefGpgALzJCrDxiCGe2N9 qintdeaLQ5UWSgg1aaKhHIOToFb3yR0= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.cz; s=susede2_ed25519; t=1648587995; h=from:from:reply-to:reply-to:date:date:message-id:message-id:to:to: cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=vm3ovff6pN64LmLXTllNgbPVeBr42U9C0Yil8UfjHOM=; b=jI1asat4WN/b6nhsCfudCDcYEC9rWNfXDHcuDJ8wXfFDjAA5jIqAqGuVqjTzKcYWgT1sUu TbgQuvgVK9xC8ICw== Received: from ds.suse.cz (ds.suse.cz [10.100.12.205]) by relay2.suse.de (Postfix) with ESMTP id F12BAA3B82; Tue, 29 Mar 2022 21:06:34 +0000 (UTC) Received: by ds.suse.cz (Postfix, from userid 10065) id 74E7CDA7F3; Tue, 29 Mar 2022 23:02:37 +0200 (CEST) Date: Tue, 29 Mar 2022 23:02:37 +0200 From: David Sterba To: Qu Wenruo Cc: linux-btrfs@vger.kernel.org Subject: Re: [PATCH 0/2] btrfs-progs: check: avoid false alerts for --check-data-csum on RAID56 Message-ID: <20220329210237.GC2237@twin.jikos.cz> Reply-To: dsterba@suse.cz Mail-Followup-To: dsterba@suse.cz, Qu Wenruo , linux-btrfs@vger.kernel.org References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23.1-rc1 (2014-03-12) Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On Tue, Mar 29, 2022 at 05:44:24PM +0800, Qu Wenruo wrote: > There is a long existing bug that btrfs-progs doesn't really support > rebuilding its data using RAID56 P/Q. > > This means any read with mirror_num > 1 for RAID56 won't work, and will > just return the P/Q raw data directly. > > The RAID56 ability in btrfs-progs is only for data write. > > This will cause tons of false alerts for "btrfs check > --check-data-csum", making it useless as an offline to verify RAID56 > data. > > The proper fix will need way more code modification (btrfs-fuse supports > that, so I believe it's possible). > > But for now, let's just disable mirror_num > 1 read repair for progs. > > Qu Wenruo (2): > btrfs-progs: avoid checking wrong RAID5/6 P/Q data > btrfs-progs: tests/fsck: add test case for data csum check on raid5 Added to devel with some fixups, thanks.