Re: [PATCH 3/8] iov_iter: Convert iter_xarray_populate_pages() to use folios

[David Hildenbrand <david@redhat.com>]

On 02.04.25 23:06, Matthew Wilcox (Oracle) wrote:
> ITER_XARRAY is exclusively used with xarrays that contain folios,
> not pages, so extract folio pointers from it, not page pointers.
> Removes a hidden call to compound_head() and a use of find_subpage().
> 
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
> ---
>   lib/iov_iter.c | 14 +++++++-------
>   1 file changed, 7 insertions(+), 7 deletions(-)
> 
> diff --git a/lib/iov_iter.c b/lib/iov_iter.c
> index 8c7fdb7d8c8f..7c50691fc5bb 100644
> --- a/lib/iov_iter.c
> +++ b/lib/iov_iter.c
> @@ -1059,22 +1059,22 @@ static ssize_t iter_xarray_populate_pages(struct page **pages, struct xarray *xa
>   					  pgoff_t index, unsigned int nr_pages)
>   {
>   	XA_STATE(xas, xa, index);
> -	struct page *page;
> +	struct folio *folio;
>   	unsigned int ret = 0;
>   
>   	rcu_read_lock();
> -	for (page = xas_load(&xas); page; page = xas_next(&xas)) {
> -		if (xas_retry(&xas, page))
> +	for (folio = xas_load(&xas); folio; folio = xas_next(&xas)) {
> +		if (xas_retry(&xas, folio))
>   			continue;
>   
> -		/* Has the page moved or been split? */
> -		if (unlikely(page != xas_reload(&xas))) {
> +		/* Has the folio moved or been split? */
> +		if (unlikely(folio != xas_reload(&xas))) {
>   			xas_reset(&xas);
>   			continue;
>   		}
>   
> -		pages[ret] = find_subpage(page, xas.xa_index);
> -		get_page(pages[ret]);
> +		pages[ret] = folio_file_page(folio, xas.xa_index);
> +		folio_get(folio);
>   		if (++ret == nr_pages)
>   			break;
>   	}

Reviewed-by: David Hildenbrand <david@redhat.com>

-- 
Cheers,

David / dhildenb