From: David Jander Subject: Re: ext4: journal has aborted Date: Fri, 4 Jul 2014 11:40:31 +0200 Message-ID: <20140704114031.2915161a@archvile> References: <20140701082619.1ac77f1d@archvile> <20140701084206.GG9743@birch.djwong.org> <20140703134338.GE2374@thunk.org> <20140703161551.5fd13245@archvile> <87tx6yzdxz.fsf@openvz.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: "Theodore Ts'o" , Matteo Croce , "Darrick J. Wong" , linux-ext4@vger.kernel.org To: Dmitry Monakhov Return-path: Received: from protonic.xs4all.nl ([83.163.252.89]:8998 "EHLO protonic.xs4all.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751537AbaGDJkY (ORCPT ); Fri, 4 Jul 2014 05:40:24 -0400 In-Reply-To: <87tx6yzdxz.fsf@openvz.org> Sender: linux-ext4-owner@vger.kernel.org List-ID: Hi Dmitry, On Thu, 03 Jul 2014 18:58:48 +0400 Dmitry Monakhov wrote: > On Thu, 3 Jul 2014 16:15:51 +0200, David Jander wrote: > > > > Hi Ted, > > > > On Thu, 3 Jul 2014 09:43:38 -0400 > > "Theodore Ts'o" wrote: > > > > > On Tue, Jul 01, 2014 at 10:55:11AM +0200, Matteo Croce wrote: > > > > 2014-07-01 10:42 GMT+02:00 Darrick J. Wong : > > > > > > > > I have a Samsung SSD 840 PRO > > > > > > Matteo, > > > > > > For you, you said you were seeing these problems on 3.15. Was it > > > *not* happening for you when you used an older kernel? If so, that > > > would help us try to provide the basis of trying to do a bisection > > > search. > > > > I also tested with 3.15, and there too I see the same problem. > > > > > Using the kvm-xfstests infrastructure, I've been trying to reproduce > > > the problem as follows: > > > > > > ./kvm-xfstests --no-log -c 4k generic/075 ; e2fsck -p /dev/heap/test-4k ; e2fsck -f /dev/heap/test-4k > > > > > > xfstests geneeric/075 runs fsx which does a fair amount of block > > > allocation deallocations, and then after the test finishes, it first > > > replays the journal (e2fsck -p) and then forces a fsck run on the > > > test disk that I use for the run. > > > > > > After I launch this, in a separate window, I do this: > > > > > > sleep 60 ; killall qemu-system-x86_64 > > > > > > This kills the qemu process midway through the fsx test, and then I > > > see if I can find a problem. I haven't had a chance to automate this > > > yet, and it is my intention to try to set this up where I can run this > > > on a ramdisk or a SSD, so I can more closely approximate what people > > > are reporting on flash-based media. > > > > > > So far, I haven't been able to reproduce the problem. If after doing > > > a large number of times, it can't be reproduced (especially if it > > > can't be reproduced on an SSD), then it would lead us to believe that > > > one of two things is the cause. (a) The CACHE FLUSH command isn't > > > properly getting sent to the device in some cases, or (b) there really > > > is a hardware problem with the flash device in question. > > > > Could (a) be caused by a bug in the mmc subsystem or in the MMC peripheral > > driver? Can you explain why I don't see any problems with EXT3? > > > > I can't discard the possibility of (b) because I cannot prove it, but I will > > try to see if I can do the same test on a SSD which I happen to have on that > > platform. That should be able to rule out problems with the eMMC chip and > > -driver, right? > > > > Do you know a way to investigate (a) (CACHE FLUSH not being sent correctly)? > > > > I left the system running (it started from a dirty EXT4 partition), and I am > > seen the following error pop up after a few minutes. The system is not doing > > much (some syslog activity maybe, but not much more): > > > > [ 303.072983] EXT4-fs (mmcblk1p2): error count: 4 > > [ 303.077558] EXT4-fs (mmcblk1p2): initial error at 1404216838: ext4_mb_generate_buddy:756 > > [ 303.085690] EXT4-fs (mmcblk1p2): last error at 1404388969: ext4_mb_generate_buddy:757 > > > > What does that mean? > This means that it found previous error in internal ext4's log. Which is > normal because your fs was corrupted before. It is reasonable to > recreate filesystem from very beginning. > > In order to understand whenever it is regression in eMMC driver it is > reasonable to run integrity test for a device itself. You can run > any integrity test you like, For example just run a fio's job > "fio disk-verify2.fio" (see attachment), IMPORTANT this script will > destroy data on test partition. If it failed with errors like > follows "verify: bad magic header XXX" than it is definitely a drivers issue. I have been trying to run fio on my board with your configuration file, but I am having problems, and since I am not familiar with fio at all, I can't really figure out what's wrong. My eMMC device is only 916MiB in size, so I edited the last part to be: offset_increment=100M size=100M Is that ok? I still get error messages complaining about blocksize though. Here is the output I get (can't really make sense of it): # ./fio ../disk-verify2.fio Multiple writers may overwrite blocks that belong to other jobs. This can cause verification failures. /dev/mmcblk1p2: (g=0): rw=randwrite, bs=4K-4K/4K-4K/4K-4K, ioengine=libaio, iodepth=32 ... fio-2.1.10-49-gf302 Starting 4 processes fio: blocksize too large for data set fio: blocksize too large for data set fio: blocksize too large for data set fio: io_u.c:1315: __get_io_u: Assertion `io_u->flags & IO_U_F_FREE' failed.ta 00m:00s] fio: pid=7612, got signal=6 /dev/mmcblk1p2: (groupid=0, jobs=1): err= 0: pid=7612: Fri Jul 4 09:31:15 2014 lat (msec) : 4=0.19%, 10=0.19%, 20=0.19%, 50=0.85%, 100=1.23% lat (msec) : 250=56.01%, 500=37.18%, 750=1.14% cpu : usr=0.00%, sys=0.00%, ctx=0, majf=0, minf=0 IO depths : 1=0.1%, 2=0.2%, 4=0.4%, 8=0.8%, 16=1.5%, 32=97.1%, >=64=0.0% submit : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0% complete : 0=0.0%, 4=100.0%, 8=0.0%, 16=0.0%, 32=0.0%, 64=0.0%, >=64=0.0% issued : total=r=33/w=1024/d=0, short=r=0/w=0/d=0 latency : target=0, window=0, percentile=100.00%, depth=32 Run status group 0 (all jobs): Disk stats (read/write): mmcblk1: ios=11/1025, merge=0/0, ticks=94/6671, in_queue=7121, util=96.12% fio: file hash not empty on exit This assertion bugs me. Is it due to the previous errors ("blocksize too large for data set") or is is because my eMMC drive/kernel is seriously screwed? Help please! > If my theory is true and it is storage's driver issue than JBD complain > simply because it do care about it's data (it does integrity checks). > Can you also create btrfs on that partition and performs some io > activity and run fsck after that. You likely will see similar corruption Best regards, -- David Jander Protonic Holland.