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 525FBC77B7A for ; Tue, 30 May 2023 01:37:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229696AbjE3BhE (ORCPT ); Mon, 29 May 2023 21:37:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59872 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229597AbjE3BhD (ORCPT ); Mon, 29 May 2023 21:37:03 -0400 X-Greylist: delayed 2586 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Mon, 29 May 2023 18:37:00 PDT Received: from out-11.mta0.migadu.com (out-11.mta0.migadu.com [IPv6:2001:41d0:1004:224b::b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 34CA9D9 for ; Mon, 29 May 2023 18:37:00 -0700 (PDT) Message-ID: <73b79a2d-95fe-dac0-9afc-8937d723ffdf@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1685410618; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=5K9sqJCgffsrxOSbEhjl0+0oxeGnqYIdW8208AD+zCU=; b=bxL7skhHMqKdnocY1hlajGhMnSbAqd3YOPwXo7szMo/CRTY522RCV3vsrP2SpmTH0cV+bc 8wl6RGSKftarWU1azMY8IiO+PE874TPocTwGOwuKKIbWv1orjat0Pq8K3sw33gVNj/uN2L hoUDPXjOjjeGc4PQP4rdDgz1hq/N3S0= Date: Tue, 30 May 2023 09:36:55 +0800 MIME-Version: 1.0 Subject: Re: The read data is wrong from raid5 when recovery happens Content-Language: en-US To: Xiao Ni Cc: "Tkaczyk, Mariusz" , Song Liu , linux-raid , Heinz Mauelshagen , Nigel Croxon References: <7e9fd8ba-aacd-3697-15fe-dc0b292bd177@linux.dev> <71c45b69-770a-0c28-3bd2-a4bd1a18bc2d@linux.dev> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Guoqing Jiang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT Precedence: bulk List-ID: X-Mailing-List: linux-raid@vger.kernel.org On 5/29/23 16:40, Xiao Ni wrote: > It's the data which customers read that can be wrong. So it's a > dangerous thing. Because customers use the data directly. If it's true > it looks like there is a race between non aligned read and recovery > process. But did you get similar report from customer from the past years? I am not sure it is reasonable to expect the md5sum should be match under such conditions (multiple processes do write/read with recovery in progress). Maybe the test launched 32 processes in parallel is another factor, not sure it still happens with only 1 process which means only do read after write. Anyway, I think io accounting is irrelevant. Thanks, Guoqing