From mboxrd@z Thu Jan 1 00:00:00 1970 From: Greg KH Subject: Re: Filesystem Mutation Tool Date: Fri, 4 Aug 2006 23:48:41 -0700 Message-ID: <20060805064841.GA26458@kroah.com> References: <44D3FD46.7070805@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel Return-path: Received: from mx2.suse.de ([195.135.220.15]:21648 "EHLO mx2.suse.de") by vger.kernel.org with ESMTP id S1161578AbWHEGs5 (ORCPT ); Sat, 5 Aug 2006 02:48:57 -0400 To: "Darrick J. Wong" Content-Disposition: inline In-Reply-To: <44D3FD46.7070805@us.ibm.com> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Fri, Aug 04, 2006 at 07:07:02PM -0700, Darrick J. Wong wrote: > Hi all, > > As I might've mentioned to a few of you at OLS, I've hacked up a quick > and dirty program to study the effects of what happens to a filesystem > when certain blocks mutate underneath it (think malice, your RAID5 > controller goes berserk, etc). Said program is now posted in a crude > form here: > > http://sweaglesw.net/~djwong/programs/fs_mutate/ > > I've run this program against ext3 and reiserfs; so far, ext3 seems to > be the stability winner, as it tends to stay up the longest (about 30-35 > minutes) even with destroy mode turned on. reiserfs lasts a few minutes > under such a beating. Of course, "stays up" is a long way from "works > properly" -- overwriting things like indirect blocks has the rather > amusing effect of generating lots of messages about falling off the end > of a drive. As with the folks who used carefully crafted ISO9660 > filesystems to crash arbitrary machines demonstrated last year, it's not > so hard to get Linux to automount filesystems. To my knowledge, > nobody's tried a similar thing against the other filesystems, though I > could just be ignorant. People have done it in the past, and found lots of bugs that have hopefully been fixed (although the iso issues have not been fixed...) > What do you think? Useful tool? Or am I the one being the tool? ;) I think it's useful, especially if it causes things to be fixed up in the kernel :) Try running it against a vfat filesystem and see if you can create some good oopses. That would be a good place to start, as USB flash sticks are more common these days than cdroms... thanks, greg k-h