From: Parag Warudkar Subject: Re: [Bug 14354] Re: ext4 increased intolerance to unclean shutdown? Date: Fri, 16 Oct 2009 18:24:18 -0400 Message-ID: References: <20091016091558.GA10184@mit.edu> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE To: Theodore Tso , Parag Warudkar , LKML , linux-ext4@vger.kernel.org, bugzilla-daemon@bugzilla.kernel.org Return-path: Received: from fg-out-1718.google.com ([72.14.220.153]:3661 "EHLO fg-out-1718.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751400AbZJPWYS convert rfc822-to-8bit (ORCPT ); Fri, 16 Oct 2009 18:24:18 -0400 In-Reply-To: <20091016091558.GA10184@mit.edu> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Fri, Oct 16, 2009 at 5:15 AM, Theodore Tso wrote: > > A number of people have reported this, and there is some discussion > and some suggestions that I've made here: > > =A0 =A0 =A0 =A0http://bugzilla.kernel.org/show_bug.cgi?id=3D14354 Ok, I went through this bug report and here are some immediately useful things to note - 1) I am not running Karmic - I am running Jaunty x86_64 clean install 2) I am not using dm/lvm or anything fancy for that matter 3) So far, I have been able to reproduce this problem by just hitting the power button on my laptop when it is doing nothing. It also happens when waking up from s2ram and the laptop wasn't doing anything when it was suspended (I mean I wasn't copying/deleting stuff, wasn't running make - laptop was > So if you can come up with a reliable reproduction case, and don't > mind doing some experiments and/or exchanging debugging correspondanc= e > with me, please let me know. =A0I'd **really** appreciate the help. My laptop is a reliable test case - for me at least! I tried just now to abruptly reset the laptop and upon reboot there was fsck followed by another reboot only to have X fail to start and NetWorkManager segfault. At this point I am pretty sure I can reproduce it just be power cycling the laptop using the power button. After another fsck and a reboot it finally comes up. > > Information that would be helpful to me would be: > > a) Detailed hardware information (what type of disk/SSD, what type of > laptop, hardware configuration, etc.) SSD is a Corsair P256 latest firmware, been used on other machine without any issues. Laptop is HP EliteBook 8530p, 4GB RAM, Intel T9400 CPU, Intel WiFi, ATI 3650 GPU. No proprietary drivers ever loaded. > > b) Detailed software information (what version of the kernel are you > using including any special patches, what distro and version are you > using, are you using LVM or dm-crypt, what partition or partitions di= d > you have mounted, was the failing partition a root partition or some > other mounted partition, etc.) It happens on current custom compiled git - both on custom and minimal localmodconfig. It also happens on Ubuntu daily kernel PPA builds. > > c) Detailed reproduction recipe (what programs were you running befor= e > the crash/failed suspend/resume, etc.) > Really nothing special - I boot to desktop, may be open FireFox for few minutes and then try reset. fsck then reports a bunch of errors and forces reboot. On reboot X fails to start, file system although mounted rw cannot be written to - vim for instance won't open any file due to write errors. Another fsck finds few more problems (or sometimes not) and reboot brings it back to desktop. So my problem is not corruption really but the amount and nature of errors fsck encounters and corrects on unclean shutdown and the write failures until another fsck -f finds more problems and reboots. None of this happens on any other filesystem including the /boot ext3 fs on the same disk. > > If you do decide to go hunting this problem, one thing I would > strongly suggest is that either to use "tune2fs -c 1 /dev/XXX" to > force a fsck after every reboot, or if you are using LVM, to use the > e2croncheck script (found as an attachment in the above bugzilla entr= y > or in the e2fsprogs sources in the contrib directory) to take a > snapshot and then check the snapshot right after you reboot and login > to your system. =A0The reported file system corruptions seem to invol= ve > the block allocation bitmaps getting corrupted, and so you will > significantly reduce the chances of data loss if you run e2fsck as > soon as possible after the file system corruption happens. =A0This he= lps > you not lose data, and it also helps us find the bug, since it helps > pinpoint the earliest possible point where the file system is getting > corrupted. I have enabled fsck on every mount but I am not certain ongoing "clean state" corruption is the problem in my case. Things have worked well without any trouble if I don't end up doing a unclean shutdown. [ snip] > I'm going to be at the kernel summit in Tokyo next week, so my e-mail > latency will be a bit longer than normal, which is one of the reason > why I've left a goodly list of potential experiments for people to > try. =A0If you can come up with a reliable regression, and are willin= g > to work with me or to try some of the above mentioned tests, I'll > definitely buy you a real (or virtual) beer. > I will try the things you mentioned - finding if this happens in pre =2E32 kernels is the first one on my list followed by reverting the specific commits you mentioned, followed if necessary by complete bisection. I am afraid however this is not a regression - at least not a recent one, as I have had this experience with ext4 and unclean shutdowns since long time. And that's on different hardware/different disks. Thanks, Parag -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html