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

Jan Kara
2025-06-17T10:08:19Z

On Tue 17-06-25 06:25:34, Lorenzo Stoakes wrote:
> 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()?

I like this name more as well :). With this patch looks good to me. Again a
note that Fixes tag would be probably appropriate for this patch...

Honza

--
Jan Kara <jack@suse.com>
SUSE Labs, CR