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

Nick Piggin
2006-10-12T15:40:57Z

On Thu, Oct 12, 2006 at 08:37:39AM -0700, Linus Torvalds wrote:
>
>
> On Thu, 12 Oct 2006, Nick Piggin wrote:
> >
> > > Are you saying that something like this would be preferable?
> >
> > I think so, it is neater and clearer. I actually didn't even bother relocking
> > and checking the page again on readpage error so got rid of quite a bit of
> > code.
>
> Well, the readpage error should be rare (and for the _normal_ case we just
> do the "wait_on_page_locked()" thing). And I think we should lock the page
> in order to do the truncation check, no?

Definitely.

> But I don't have any really strong feelings. I'm certainly ok with the
> patch I sent out. How about putting it through -mm? Here's my sign-off:
>
> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
>
> if you want to send it off to Andrew (or if Andrew wants to just take it
> himself ;)

OK... maybe it can wait till the other changes, and we can think about
it then. I'll carry around the split out patct, though.

> Btw, how did you even notice this? Just by reading the source, or because
> you actually saw multiple errors reported?

Reading the source, thinking about the cleanups we can do if filemap_nopage
takes the page lock...