Re: [PATCH 03/10] fs: consistently use file_has_valid_mmap_hooks() helper

Lorenzo Stoakes
2025-06-17T05:27:38Z

On Mon, Jun 16, 2025 at 10:11:28PM -0700, Christoph Hellwig wrote:
> On Mon, Jun 16, 2025 at 08:33:22PM +0100, Lorenzo Stoakes wrote:
> > Since commit c84bf6dd2b83 ("mm: introduce new .mmap_prepare() file
> > callback"), the f_op->mmap() hook has been deprecated in favour of
> > f_op->mmap_prepare().
> >
> > Additionally, commit bb666b7c2707 ("mm: add mmap_prepare() compatibility
> > layer for nested file systems") permits the use of the .mmap_prepare() hook
> > even in nested filesystems like overlayfs.
> >
> > There are a number of places where we check only for f_op->mmap - this is
> > incorrect now mmap_prepare exists, so update all of these to use the
> > general helper file_has_valid_mmap_hooks().
> >
> > Most notably, this updates the elf logic to allow for the ability to
> > execute binaries on filesystems which have the .mmap_prepare hook, but
> > additionally we update nested filesystems.
>
> Can you please give the function a better name before spreading it?
> file operations aren't hooks by any classic definition.
>

can_mmap_file()?