Re: [PATCH] mm/filemap: do not allocate cache pages beyond end of file at read

[Kirill A. Shutemov]

On Mon, Oct 28, 2019 at 01:47:16PM +0100, Linus Torvalds wrote:
> On Mon, Oct 28, 2019 at 1:42 PM Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> wrote:
> >
> > I've tried something of this sort back in 2013:
> >
> > http://lore.kernel.org/r/1377099441-2224-1-git-send-email-kirill.shutemov@xxxxxxxxxxxxxxx
> >
> > and I've got push back.
> >
> > Apparently, some filesystems may not have valid i_size before >readpage().
> > Not sure if it's still the case...
> 
> Well, I agree that there might be some network filesystem that might
> have inode sizes that are stale, but if that's the case then I don't
> think your previous patch works either.
> 
> It too will avoid the readpage() if the read position is beyond i_size.
> 
> No?

Yes. That's the reason the patch was rejected back then.

My point is that we need to make sure that this patch not break anything.

-- 
 Kirill A. Shutemov