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Date: Mon, 10 Dec 2001 13:13:53 +0100
From: Pavel Machek <pavel@suse.cz>
To: "Albert D. Cahalan" <acahalan@cs.uml.edu>
Cc: Quinn Harris <quinn@nmt.edu>, linux-kernel@vger.kernel.org
Subject: Re: File copy system call proposal
Message-ID: <20011210131353.C19142@atrey.karlin.mff.cuni.cz>
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Hi!

> >> I would like to propose implementing a file copy system call.
> >> I expect the initial reaction to such a proposal would be "feature
> >> bloat" but I believe some substantial benefits can be seen possibly
> >> making it worthwhile, primarily the following:
> >>
> >> Copy on write:
> >
> > You want cowlink() syscall, not copy() syscall. If they are on different
> > partitions, let userspace do the job.
> 
> That looks like a knee-jerk reaction to stuff going in the kernel.
> I want maximum survival of non-UNIX metadata and maximum performance
> for this common operation. Let's say you are telecommuting, and...

It would be very ugly if cp -a started behaving differently after you
upgrade it to use copyfile(). Better preserve only metadata you
"know".
								Pavel
-- 
Casualities in World Trade Center: 6453 dead inside the building,
cryptography in U.S.A. and free speech in Czech Republic.
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