Re: [PATCH] zerocopy NFS updated

Mike Fedyk
2002-04-16T00:15:41Z

On Thu, Apr 11, 2002 at 03:16:16PM +0200, Andi Kleen wrote:
> On Thu, Apr 11, 2002 at 04:00:37PM -0200, Denis Vlasenko wrote:
> > On 11 April 2002 09:36, David S. Miller wrote:
> > > No, you must block truncate operations on the file until the client
> > > ACK's the nfsd read request if you wish to use sendfile() with
> > > nfsd.
> >
> > Which shouldn't be a big performance problem unless I am unaware
> > of some real-life applications doing heavy truncates.
>
> Every unlink does a truncate. There are applications that delete files
> a lot.

Is this true at the filesystem level or only in memory? If so, I could
immagine that it would make it much harder to undelete a file when you don't
even know how big it was (file set to 0 size)...

Why is this required? Could someone say quickly (as I'm sure it's probably
quite complex) or point me to some references?