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From: David Lang <david.lang@digitalinsight.com>
To: "Peter T. Breuer" <ptb@it.uc3m.es>
Cc: linux-kernel@vger.kernel.org
Date: Tue, 3 Sep 2002 16:05:27 -0700 (PDT)
Subject: Re: (fwd) Re: [RFC] mount flag "direct"
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On Tue, 3 Sep 2002, Peter T. Breuer wrote:

> > in addition you will have lots of potential races as one system reads a
> > block of data, modifies it, then writes it while the other system does the
>
> Uh, I am confident that there can  be no races with respect to data
> writes provided I manage to make the VFS operations atomic via
> appropriate shared locking. What one has to get rid of is cached
> metadata state. I'm open to suggestions.

well you will have to change the filesystems to attempt your new atomic
VFS operations, today the kernel ext2 driver can just aquire a lock,
diddle with whatever it wants, and write the result. it doesn't do
anything that the VFS will see as atomic.

David Lang

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