Date: Mon, 29 Oct 2007 10:10:01 -0400
From: Chris Mason <chris.mason@oracle.com>
To: Anton Altaparmakov <aia21@cam.ac.uk>
Cc: Mike Waychison <mikew@google.com>, linux-fsdevel@vger.kernel.org,
       linux-kernel@vger.kernel.org
Subject: Re: [patch 0/6][RFC] Cleanup FIBMAP
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	<E579083F-FED3-4990-8E24-275ED38E9E3B@cam.ac.uk>
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On Sat, 27 Oct 2007 18:57:06 +0100
Anton Altaparmakov <aia21@cam.ac.uk> wrote:

> Hi,
> 
> ->bmap is ugly and horrible!  If you have to do this at the very
> least please cause ->bmap64 to be able to return error values in case
> the file system failed to get the information or indeed such
> information does not exist as is the case for compressed and
> encrypted files for example and also for small files that are inside
> the on-disk inode (NTFS resident files and reiserfs packed tails are
> examples of this).
> 
> And another of my pet peeves with ->bmap is that it uses 0 to mean  
> "sparse" which causes a conflict on NTFS at least as block zero is  
> part of the $Boot system file so it is a real, valid block...  NTFS  
> uses -1 to denote sparse blocks internally.

Reiserfs and Btrfs also use 0 to mean packed.  It would be nice if there
was a way to indicate your-data-is-here-but-isn't-alone.  But that's
more of a feature for the FIEMAP stuff.

-chris
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