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Date: Tue, 3 Sep 2002 17:53:39 +0200 (MET DST)
From: "Maciej W. Rozycki" <macro@ds2.pg.gda.pl>
To: Rik van Riel <riel@conectiva.com.br>
cc: "Peter T. Breuer" <ptb@it.uc3m.es>,
       linux kernel <linux-kernel@vger.kernel.org>
Subject: Re: [RFC] mount flag "direct"
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Organization: Technical University of Gdansk
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On Tue, 3 Sep 2002, Rik van Riel wrote:

> > Rationale:
> > No caching means that each kernel doesn't go off with its own idea of
> > what is on the disk in a file, at least. Dunno about directories and
> > metadata.
> 
> And what if they both allocate the same disk block to another
> file, simultaneously ?

 You need a mutex then.  For SCSI devices a reservation is the way to go
-- the RESERVE/RELEASE commands are mandatory for direct-access devices,
so thy should work universally for disks.

-- 
+  Maciej W. Rozycki, Technical University of Gdansk, Poland   +
+--------------------------------------------------------------+
+        e-mail: macro@ds2.pg.gda.pl, PGP key available        +

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