Re: [PATCH] zerocopy NFS updated

David S. Miller
2002-04-12T21:39:32Z

From: Jamie Lokier <lk@tantalophile.demon.co.uk>
Date: Fri, 12 Apr 2002 22:22:52 +0100

I'm not advocating more locking in read() -- there's no need, and it is
quite important that it is fast! But I would very much appreciate an
understanding of the rules that relate reading, writing and truncating
processes. How much ordering & atomicity can I depend on? Anything at all?

Basically none it appears :-)

If you need to depend upon a consistent snapshot of what some other
thread writes into a file, you must have some locking protocol to use
to synchronize with that other thread.