From owner-freebsd-stable@FreeBSD.ORG Mon Jun 16 12:16:13 2008 Return-Path: Delivered-To: freebsd-stable@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 296C8106567B; Mon, 16 Jun 2008 12:16:13 +0000 (UTC) (envelope-from cracauer@koef.zs64.net) Received: from koef.zs64.net (koef.zs64.net [212.12.50.230]) by mx1.freebsd.org (Postfix) with ESMTP id AB5298FC25; Mon, 16 Jun 2008 12:16:12 +0000 (UTC) (envelope-from cracauer@koef.zs64.net) Received: from koef.zs64.net (koef.zs64.net [212.12.50.230]) by koef.zs64.net (8.14.3/8.14.3) with ESMTP id m5GCG9F7027079; Mon, 16 Jun 2008 14:16:09 +0200 (CEST) (envelope-from cracauer@koef.zs64.net) Received: (from cracauer@localhost) by koef.zs64.net (8.14.3/8.14.3/Submit) id m5GCG9Zp027078; Mon, 16 Jun 2008 08:16:09 -0400 (EDT) (envelope-from cracauer) Date: Mon, 16 Jun 2008 08:16:09 -0400 From: Martin Cracauer To: Kris Kennaway Message-ID: <20080616121609.GA26978@cons.org> References: <20080118120140.2a8170a0@dev> <47921931.9050606@FreeBSD.org> <47921AE2.1060004@FreeBSD.org> <20080301220924.72bf355d@dev.citybikes.cz> <47C9C912.1020700@FreeBSD.org> <20080616034258.GA94873@cons.org> <48563219.9070306@FreeBSD.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <48563219.9070306@FreeBSD.org> User-Agent: Mutt/1.4.2.3i Cc: maxim@FreeBSD.org, freebsd-stable@FreeBSD.org, Jakub Siroky , freebsd-fs@FreeBSD.org, cracauer@FreeBSD.org, Martin Cracauer Subject: Re: infinite loop when copying to ext2fs X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 16 Jun 2008 12:16:13 -0000 Kris Kennaway wrote on Mon, Jun 16, 2008 at 11:27:53AM +0200: > Martin Cracauer wrote: > >Kris Kennaway wrote on Sat, Mar 01, 2008 at 10:22:26PM +0100: > >>Jakub Siroky wrote: > >>>I've just confirmed the same situation on 6.2-RELEASE amd64/GENERIC. I > >>>did not noticed it before because I started using ext2fs extensively > >>>some months ago. > >>> > >>>Regards, > >>>Jakub > >>> > >>>On Sat, 19 Jan 2008 16:44:34 +0100 > >>>Kris Kennaway wrote: > >>> > >>>>Kris Kennaway wrote: > >>>>>Jakub Siroky wrote: > >>>>>>I have two large ext2fs partitions (368 and 313GB) to hold data > >>>>>>shared between several OSes. While there were no problems on > >>>>>>6-STABLE branch I was quite disappointed after upgrade to > >>>>>>7-STABLE. Whenever I copy/write to ext2fs partition the system > >>>>>>freezes totally without crashdump. So I set debugging settings to > >>>>>>kernel config (DEBUG,WITNESS,..) and in console I reproduced error > >>>>>>situation ending with full screen of unstoppable running text with > >>>>>>lot of memory addresses and a few recognisable words: 'new block > >>>>>>bit set for ext already' - again with no crashdump. Then I have > >>>>>>formatted 1GB partition with ext2fs and the problem on this small > >>>>>>partition appears only sometimes. > >>>>>OK, I am able to reproduce this. > >>>>> > >>>>>Kris > >>>>> > >>>>Is anyone able to look at this? I could not spot a candidate change > >>>>that has not been merged to 6.x. > >>>> > >>>>Kris > >>> > >>Sounds like it may have been broken by the change to ext2_bitops.h by > >>cracauer. Can you confirm whether backing out 1.2.2.1 fixes it? > > > >I don't think my change can cause a new endless loop. > > > >I only reversed the order of tests to ensure we don't overrun a page > >bounddary (into possibly unmapped space). > > > >- while(*p == ~0U && ofs < sz) { > >+ while(ofs < sz && *p == ~0U) { > > > >It is, however, likely that the code was buggy in the first place. > >Linux has replaced all this (the allocation code). > > > >Also note that the code I fixed is amd64 only. If the endless loop > >appears on i386 it's something else. > > > >Martin > > It is amd64 only. I am able to reproduce using the method in the > original mails, can you? Didn't try yet, but I did get a probably unrelated panic on ext2fs just last week :-) I'll fire it up this week. How big does the partition have to be to show the problem in this bug? Martin -- %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Martin Cracauer http://www.cons.org/cracauer/ FreeBSD - where you want to go, today. http://www.freebsd.org/