Subject: Re: precise characterization of ext3 atomicity
From: Chris Mason <mason@suse.com>
To: Andreas Dilger <adilger@clusterfs.com>
Cc: Hans Reiser <reiser@namesys.com>, Mike Fedyk <mfedyk@matchmail.com>,
       Andrew Morton <akpm@osdl.org>, reiserfs-list@namesys.com,
       linux-kernel@vger.kernel.org
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Date: 05 Sep 2003 09:47:20 -0400
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On Thu, 2003-09-04 at 18:03, Andreas Dilger wrote:
> On Sep 05, 2003  01:32 +0400, Hans Reiser wrote:
> > Andreas Dilger wrote:
> > >It is possible to do the same with ext3, namely exporting journal_start()
> > >and journal_stop() (or some interface to them) to userspace so the application
> > >can start a transaction for multiple operations.  We had discussed this in
> > >the past, but decided not to do so because user applications can screw up in
> > >so many ways, and if an application uses these interfaces it is possible to
> > >deadlock the entire filesystem if the application isn't well behaved.
> >
> > That's why we confine it to a (finite #defined number) set of 
> > operations within one sys_reiser4 call.  At some point we will allow 
> > trusted user space processes to span multiple system calls (mail server 
> > applicances, database appliances, etc., might find this useful).  You 
> > might consider supporting sys_reiser4 at some point.

Please rename sys_reiser4 if you want it to be a generic use syscall ;-)

-chris


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