From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Subject: Re: mballoc errors
Date: Tue, 1 Apr 2008 01:48:19 +0530
Message-ID: <20080331201819.GA30646@skywalker>
References: <47EAC302.5040109@redhat.com> <47ECFAC7.3050404@bull.net> <20080331065802.GA19456@skywalker> <47F0FBFE.7060404@bull.net>
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Cc: linux-ext4 <linux-ext4@vger.kernel.org>
To: Valerie Clement <valerie.clement@bull.net>
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Sender: linux-ext4-owner@vger.kernel.org

On Mon, Mar 31, 2008 at 04:58:06PM +0200, Valerie Clement wrote:
> Aneesh Kumar K.V wrote:
>> I looked at the code. Nothing appears straight. I am now running tests.
>> meanwhile you can dump the block ee_pblock in the ext4_ext_zeroout
>> and see if we are zeroing some wrong blocks that would be great.
>>
> I didn't see anything incorrect here for the moment, but adding traces
> in the code often changes the behavior so that I can't reproduce the problem
> running the same test.
>
>>
>>> How I reproduce the problem:
>>> # mkfs.ext3 -I256 -E test_fs -b 1024 /dev/sdc1
>>> # mount -t ext4dev /dev/sdc1 /mnt/test
>>> # fsstress -d /mnt/test -n1000 -p1000
>>>
>>
>> Does the fsstress you are using have fallocate support ?. If so can you 
>> send me the patch so that i can run the same test. 
> No, the fsstress I'm using doesn't support fallocate.

That means it is not due to ext4_ext_zeroout. Which implies we have a
generic file system corruption.

>
>> Also can you disable delalloc and try.
> OK, done. The tests are still running.
>
>> ENOSPC handling with delalloc is not yet done
> I often got the problem when the disk is filled to 10% of its capacity.
>
>

I actually added fallocate to fsstress and created the file filesystem
as you suggested. I am able to reproduce the problem once. Currently
doing a code audit. Will let you know if i make any progress.


-aneesh
>