From: Theodore Tso <tytso@mit.edu>
Subject: Re: data corruption with ext4 (from 2.6.27.4) exposed by rtorrent
Date: Mon, 3 Nov 2008 08:40:08 -0500
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Cc: Cryptooctoploid <cryptooctoploid@gmail.com>,
	linux-ext4@vger.kernel.org
To: Roc Valles <vallesroc@gmail.com>
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On Mon, Nov 03, 2008 at 12:42:11PM +0000, Roc Valles wrote:
> Some person already reported this. I'm having the same problem.
> http://marc.info/?l=linux-ext4&m=122557056518246&w=2
>
> rtorrent is a bittorrent client that makes heavy use of mmap instead
> of read/write to avoid needless duplication of data. It has exposed
> other bugs in the past (mmap bug in 2.6.19).
> http://libtorrent.rakshasa.no
> Downloading a big torrent (>2GB) with rtorrent triggers it more times
> than not. The bigger the torrent, the higher the likeliness of
> failure. When the torrent is finished, if a hash check is forced by
> pressing control-r on the torrent, some blocks will fail.

Can both of you send the output of "dumpe2fs -h /dev/<disk device>" of
the filesystem in question?  The thing which I'm most interested in is
whether the extents feature was enabled or not.  (i.e., was this a
freshly made ext4 filesystem, or a ext3 filesystem mounted under ext4,
and with which features eanbled?)

Thanks,

						- Ted