Subject: Re: cp(1) vs. UVM/UBC
To: None <tech-userlevel@netbsd.org>
From: Ignatios Souvatzis <is@netbsd.org>
List: tech-userlevel
Date: 07/21/2001 10:49:00
On Sat, Jul 21, 2001 at 07:53:23AM +0200, Matthias Scheler wrote:
> On Fri, Jul 20, 2001 at 10:52:42PM +0200, Ignatios Souvatzis wrote:
> > > We could always have the file system itself fail the mmap in the interim,
> > > if need be, until it is in fact fixed.  Not all filesystems necessarily
> > > *must* support mmap; just return -1 and an errno, and let smart code fall
> > > back.  8-)
> > 
> > how does it do it?
> 
> He is talking about smart userland code. "cp" e.g. would simply use the
> old read(2) loop in this case.

Thats easy. No, how do I teach adosfs to return -1 (shouldn't that be NULL?)
for some invocations of mmap()?

Regards,
	-is