Re: [GIT PULL] ext4 changes for the 6.4 merge window

[Nick Desaulniers <ndesaulniers@google.com>]

On Wed, Apr 26, 2023 at 10:34 AM Nick Desaulniers
<ndesaulniers@google.com> wrote:
>
> On Wed, Apr 26, 2023 at 10:03 AM Linus Torvalds
> <torvalds@linux-foundation.org> wrote:
> >
> > On Mon, Apr 24, 2023 at 9:18 PM Theodore Ts'o <tytso@mit.edu> wrote:
> > >
> > > Please note that after merging the mm and ext4 trees you will need to
> > > apply the patch found here[1].
> > >
> > > [1] https://lore.kernel.org/r/20230419120923.3152939-1-willy@infradead.org
> > >
> > > This is due to a patch in the mm tree, "mm: return an ERR_PTR from
> > > __filemap_get_folio" changing that function to returning an ERR_PTR
> > > instead of returning NULL on an error.
> >
> > Side note, itr would be wonderful if we could mark the places that
> > return an error pointer as returning "nonnull", and catch things like
> > this automatically at build time where people compare an error pointer
> > to NULL.
>
> That's what clang's _Nonnull attribute does (with -Wnullability-extension).
> https://godbolt.org/z/6jo1zbMd9

Ah sorry, I _thought_ that's how _Nonnull worked on return types. Let
me dig some more and see how that's supposed to work...

-- 
Thanks,
~Nick Desaulniers