Re: [PATCH v9 1/8] mm: Introduce memfd_restricted system call to create restricted user memory

[Chao Peng]

On Wed, Oct 26, 2022 at 10:31:45AM -0700, Isaku Yamahata wrote:
> On Tue, Oct 25, 2022 at 11:13:37PM +0800,
> Chao Peng <chao.p.peng@xxxxxxxxxxxxxxx> wrote:
> 
> > +int restrictedmem_get_page(struct file *file, pgoff_t offset,
> > +			   struct page **pagep, int *order)
> > +{
> > +	struct restrictedmem_data *data = file->f_mapping->private_data;
> > +	struct file *memfd = data->memfd;
> > +	struct page *page;
> > +	int ret;
> > +
> > +	ret = shmem_getpage(file_inode(memfd), offset, &page, SGP_WRITE);
> 
> shmem_getpage() was removed.
> https://lkml.kernel.org/r/20220902194653.1739778-34-willy@xxxxxxxxxxxxx

Thanks for pointing out. My current base(kvm/queue) has not included
this change yet so still use shmem_getpage().

Chao
> 
> I needed the following fix to compile.
> 
> thanks,
> 
> diff --git a/mm/restrictedmem.c b/mm/restrictedmem.c
> index e5bf8907e0f8..4694dd5609d6 100644
> --- a/mm/restrictedmem.c
> +++ b/mm/restrictedmem.c
> @@ -231,13 +231,15 @@ int restrictedmem_get_page(struct file *file, pgoff_t offset,
>  {
>         struct restrictedmem_data *data = file->f_mapping->private_data;
>         struct file *memfd = data->memfd;
> +       struct folio *folio = NULL;
>         struct page *page;
>         int ret;
>  
> -       ret = shmem_getpage(file_inode(memfd), offset, &page, SGP_WRITE);
> +       ret = shmem_get_folio(file_inode(memfd), offset, &folio, SGP_WRITE);
>         if (ret)
>                 return ret;
>  
> +       page = folio_file_page(folio, offset);
>         *pagep = page;
>         if (order)
>                 *order = thp_order(compound_head(page));
> -- 
> Isaku Yamahata <isaku.yamahata@xxxxxxxxx>