From: Jan Kara <jack@suse.cz>
Subject: Re: [RFC] do you want jbd2 interface of ext3?
Date: Tue, 16 Feb 2010 19:54:52 +0100
Message-ID: <20100216185452.GE3153@quack.suse.cz>
References: <20100216164123.b10b00e5.toshi.okajima@jp.fujitsu.com>
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Cc: akpm@linux-foundation.org, adilger@sun.com, jack@suse.cz,
	linux-ext4@vger.kernel.org
To: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
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Sender: linux-ext4-owner@vger.kernel.org

  Hello,

On Tue 16-02-10 16:41:23, Toshiyuki Okajima wrote:
> I will try to change the journaling interface of ext3 from jbd into jbd2.
> 
> jbd2 has new features from jbd. For example, it includes the integrity 
> improvement features. The body of ext3 is already enough quality. If ext3 
> changes the journaling interface from jbd into jbd2, ext3 filesystem with jbd2
> interface may get better integrity than with the jbd interface.
> (jbd2 is aggressively being developed now, so I think we are glad if we can 
> get the effect of the development of jbd2 for ext3.)
> 
> And ext3 is as de facto standard filesystem, so jbd2 component will be used 
> by more people than now if ext3 has the jbd2 interface. If many people used 
> the jbd2 interface of ext3, the jbd2 component would get more chances to 
> improve the quality and performance and so on. 
> 
> Besides, ext3 is now the only user of jbd. 
> (ocfs2 which was the user of jbd is now the user of jbd2.)
> 
> Do you want the jbd2 interface of ext3?
> If you want the jbd2 interface, I will try to implement one.
  Yes, as Ted pointed out, the main reason why we have a separate codebase for
ext3 and ext4 and similarly jbd and jbd2 is that we didn't want the changes
in ext4/jbd2 to influence (and possibly destabilize) ext3 filesystem. So
switching ext3 to jbd2 would be directly against this logic...

								Honza
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR