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

Christian Brauner
2025-06-17T11:48:36Z

On Tue, Jun 17, 2025 at 12:08:13PM +0200, Jan Kara wrote:
> 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

Fixed in-tree.