Re: [patch 2/5] mm: fault vs invalidate/truncate race fix

Nick Piggin
2006-10-11T09:21:58Z

On Tue, Oct 10, 2006 at 11:00:42PM -0700, Andrew Morton wrote:
> On Wed, 11 Oct 2006 15:39:22 +1000
> Nick Piggin <nickpiggin@yahoo.com.au> wrote:
>
> > But I see that it does read twice. Do you want that behaviour retained? It
> > seems like at this level it would be logical to read it once and let lower
> > layers take care of any retries?
>
> argh. Linus has good-sounding reasons for retrying the pagefault-path's
> read a single time, but I forget what they are. Something to do with
> networked filesystems? (adds cc)

While you're there, can anyone tell me why we want an external
ptracer to be able to access pages that are outside i_size? I
haven't removed the logic of course, but I'm curious about the
history and usage of such a thing.