linux-ext4 - Re: [PATCH] make ext4_valid_block

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Message-ID: <4CE186EF.2090508@ddn.com>
Date:	Mon, 15 Nov 2010 20:15:59 +0100
From:	Bernd Schubert <bschubert@....com>
To:	Andreas Dilger <adilger.kernel@...ger.ca>
CC:	Bernd Schubert <bs_lists@...ef.fastmail.fm>,
	"linux-ext4@...r.kernel.org" <linux-ext4@...r.kernel.org>
Subject: Re: [PATCH] make ext4_valid_block_bitmap() more verbose

On 11/13/2010 12:56 AM, Andreas Dilger wrote:
> On 2010-11-12, at 16:26, Bernd Schubert wrote:
>> The real issue we want to debug with the patch below actually came
>> up while stress testing Lustre using the RHEL5.5 kernel (so
>> 2.6.32'ish ext4), but a more verbose error function should not hurt
>> for vanilla ext4 either.
>> 
>> make ext4_valid_block_bitmap() more verbose
>> 
>> While running our stress test suite, ext4_valid_block_bitmap() 
>> frequently complains about an invalid block bitmap. However, e2fsck
>> does not find anything. So in oder to be able to better debug this
>> issue, make the function more verbose and let it complain about the
>> two possible invalid bitmaps.
> 
> Bernd, thanks for sending this in.  I like the idea of making these
> messages more verbose, since they should rarely be hit and when they
> are it would be good to know why these checks failed.

Andreas, thanks for your helpful review, I will send an updated patch on
Wednesday.

>> +	if (!valid) +		ext4_error(sb, "Invalid block bitmap - block_group
>> = %d", +			   block_group);
> 
> It would probably be worthwhile to also print the block number of the
> bitmap itself.

I guess you mean bitmap_blk here? But that changes for every of the
possible checks, so I already printed it above. Is it worth to print it
again? And what if more than one problem is found, might become a bit
confusing then?


Thanks,
Bernd


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