From: sho@tnes.nec.co.jp
Subject: Re: [RFC] Ext3 online defrag
Date: Fri, 27 Oct 2006 16:23:26 +0900
Message-ID: <20061027162326sho@rifu.tnes.nec.co.jp>
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Cc: tytso@mit.edu, jack@suse.cz, linux-fsdevel@vger.kernel.org,
	linux-ext4@vger.kernel.org
To: alex@clusterfs.com
Sender: linux-ext4-owner@vger.kernel.org


Hi,

> TT> On Mon, Oct 23, 2006 at 02:27:10PM +0200, Jan Kara wrote:
> >> Hello,
> >>
> >> I've written a simple patch implementing ext3 ioctl for file
> >> relocation. Basically you call ioctl on a file, give it list of blocks
> >> and it relocates the file into given blocks (provided they are still
> >> free). The idea is to use it as a kernel part of ext3 online
> >> defragmenter (or generally disk access optimizer).
>
>isn't that a kernel responsbility to find/allocate target blocks?
>wouldn't it better to specify desirable target group and minimal
>acceptable chunk of free blocks?

Agreed.

I am considering the online defrag function for ext4 and thinking
that your following patch set for multi-block allocation is useful
to search contiguous free blocks for the defragmentation.

"[RFC] extents,mballoc,delalloc for 2.6.16.8" 
http://marc.theaimsgroup.com/?l=linux-ext4&m=114669168616780&w=2

I will send the patch of simple defrag implementation for ext4 later.

Cheers, Takashi