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Date: Thu, 6 Dec 2001 17:48:42 -0500 (EST)
From: Alexander Viro <viro@math.psu.edu>
To: Larry McVoy <lm@bitmover.com>
cc: Alan Cox <alan@lxorguk.ukuu.org.uk>,
        Daniel Phillips <phillips@bonn-fries.net>,
        "David S. Miller" <davem@redhat.com>, davidel@xmailserver.org,
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        lars.spam@nocrew.org, hps@intermeta.de, linux-kernel@vger.kernel.org
Subject: Re: SMP/cc Cluster description
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On Thu, 6 Dec 2001, Larry McVoy wrote:

> I'm not sure what the point is.  We've already agreed that the multiple OS
> instances will have synchonization to do for file operations, ftruncate
> being one of them.

That's nice.  But said operation involves serious wanking with metadata
and _that_ would better have exclusion with write(2) and some warranties
about pageouts.

You can do lockless get_block() and truncate().  And it will be a hive
of races always ready to break out.  We used to try that and it was
a fscking mess of unbelievable proportions - worse than that in full-blown
rename() support.

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