Date: Thu, 4 Sep 2003 08:55:37 -0700
From: Andrew Morton <akpm@osdl.org>
To: Hans Reiser <reiser@namesys.com>
Cc: reiserfs-list@namesys.com, linux-kernel@vger.kernel.org
Subject: Re: precise characterization of ext3 atomicity
Message-Id: <20030904085537.78c251b3.akpm@osdl.org>
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Hans Reiser <reiser@namesys.com> wrote:
>
> Is it correct to say of ext3 that it guarantees and only guarantees 
> atomicity of writes that do not cross page boundaries?

Yes.

>     By contrast, ext3 only guarantees the atomicity of a single write 
> that does not span a page boundary, and it guarantees that its internal 
> metadata will not be corrupted even if your applications data is 
> corrupted after the crash.

Not sure that I understand this.  In data=writeback mode, metadata
integrity is preserved but data writes may be lost.  In data=journal and
data=ordered modes the data and the metadata which refers to it are always
in sync on-disk.

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