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Message-ID: <3C5ED7A6.C28407BA@mandrakesoft.com>
Date: Mon, 04 Feb 2002 13:49:10 -0500
From: Jeff Garzik <jgarzik@mandrakesoft.com>
Organization: MandrakeSoft
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To: Joel Becker <jlbec@evilplan.org>
CC: Alan Cox <alan@lxorguk.ukuu.org.uk>, Steve Lord <lord@sgi.com>,
        Chris Wedgwood <cw@f00f.org>, Chris Mason <mason@suse.com>,
        Andrea Arcangeli <andrea@suse.de>, Andrew Morton <akpm@zip.com.au>,
        Ricardo Galli <gallir@uib.es>,
        Linux Kernel <linux-kernel@vger.kernel.org>,
        linux-fsdevel@vger.kernel.org
Subject: Re: O_DIRECT fails in some kernel and FS
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Joel Becker wrote:
> should know the caches might be inconsistent.  Large O_DIRECT users,
> such as databases, already know this.  They are happily ignorant of
> cache inconsistencies.  All they care about is hardsectsize O_DIRECT
> operations.

I have similar inclination, that is inspired from the implementation of
"NTFS TNG": hard sector size should always equal sb->blocksize.  This
allows for fine-grained operations at the O_DIRECT level, logical block
sizes > PAGE_CACHE_SIZE, easy implementation of fragments (>= hard sect
size), O_DIRECT for fragments, and other stuff.

This works right now in 2.4 and 2.5 with no modification to the VFS
core.

	Jeff



-- 
Jeff Garzik      | "I went through my candy like hot oatmeal
Building 1024    |  through an internally-buttered weasel."
MandrakeSoft     |             - goats.com
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