From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262187AbTJFTIe (ORCPT ); Mon, 6 Oct 2003 15:08:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262156AbTJFTId (ORCPT ); Mon, 6 Oct 2003 15:08:33 -0400 Received: from mion.elka.pw.edu.pl ([194.29.160.35]:11147 "EHLO mion.elka.pw.edu.pl") by vger.kernel.org with ESMTP id S262187AbTJFTH4 (ORCPT ); Mon, 6 Oct 2003 15:07:56 -0400 From: Bartlomiej Zolnierkiewicz To: "Daniel B." Subject: Re: IDE DMA errors, massive disk corruption: Why? Fixed Yet? Why not re-do failed op? Date: Mon, 6 Oct 2003 21:11:17 +0200 User-Agent: KMail/1.5.4 References: <3F81B790.B8AF7136@smart.net> In-Reply-To: <3F81B790.B8AF7136@smart.net> Cc: "linux-kernel@vger.kernel.org" MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-2" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200310062111.17006.bzolnier@elka.pw.edu.pl> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org There are different IDE DMA errors. Please post error, dmesg and .config. On Monday 06 of October 2003 20:42, Daniel B. wrote: > I just got bitten _again_ by IDE DMA timeout errors and massive > filesystem corruption in kernel 2.4.22 (on an Asus A7M266-D dual-Athlon > XP motherboard (AMD 768 chip / amd7441 IDE controller)). > > (I had turned DMA off in my init scripts, but apparently Debian > unstable's k7-smp configuration enables DMA by default before my init > scripts get control. Ext3 journal "recovery" trashed my system > partition.) > > What's going on with the IDE DMA bugs? They have existed since 2.2 > (right?), and even at .22 in the 2.4 series they still exist. Why > have they been around so long? Is it that few kernel developers use > the combinations of hardware or configuration options that expose > the bugs (like my dual-CPU box with IDE, not SCSI, disks)? Well, yes, I have no problems for example :-). > Are the DMA bugs believed to be fixed (for real) yet? IF so, in which > version? > > Is there any consolidated documentation of the combinations of factors > that cause corruption, or of how to reliably avoid corruption (like > all the things to check to make sure your kernel never even tries to > enable DMA)? > > > Also, why does a DMA timeout cause such corruption? Doesn't the kernel > keep track of uncompleted operations, retain the information needed to > try again, and try again if there's a failure? If not, why not? > > If it can't try again, shouldn't the kernel at least abort after one > disk-write failure instead of performing additional writes, which > frequently depend on the previous writes? (E.g., if I try to read > block 1's data and write it to block 2, and then write something new > to block 1, if the first write fails but continue and do the second > write, data gets destroyed. If the first write fails and I stop right > away, less is destroyed.) Are you sure you don't have faulty drive? --bartlomiej