Re: [PATCH 02/10] mm/nommu: use file_has_valid_mmap_hooks() helper

From: Jan Kara
Date: Tue Jun 17 2025 - 06:06:15 EST


On Mon 16-06-25 20:33:21, 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().
>
> Therefore, update the check for file operations supporting mmap() by using
> the file_has_valid_mmap_hooks() helper function, which checks for either
> f_op->mmap or f_op->mmap_prepare rather than checking only for f_op->mmap
> directly.
>
> Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

Maybe Fixes tag would be appropriate here?

Honza

> ---
> mm/nommu.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/nommu.c b/mm/nommu.c
> index b624acec6d2e..38c22ea0a95c 100644
> --- a/mm/nommu.c
> +++ b/mm/nommu.c
> @@ -719,7 +719,7 @@ static int validate_mmap_request(struct file *file,
>
> if (file) {
> /* files must support mmap */
> - if (!file->f_op->mmap)
> + if (!file_has_valid_mmap_hooks(file))
> return -ENODEV;
>
> /* work out if what we've got could possibly be shared
> --
> 2.49.0
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR