On Fri, Sep 15, 2023 at 08:38:28PM +0200, Pankaj Raghav wrote:
> +++ b/mm/filemap.c
> @@ -1862,6 +1862,10 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index,
> fgf_t fgp_flags, gfp_t gfp)
> {
> struct folio *folio;
> + int min_order = mapping_min_folio_order(mapping);
> + int nr_of_pages = (1U << min_order);
> +
> + index = round_down(index, nr_of_pages);
>
> repeat:
> folio = filemap_get_entry(mapping, index);
> @@ -1929,8 +1933,14 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index,
> err = -ENOMEM;
> if (order == 1)
> order = 0;
> + if (order < min_order)
> + order = min_order;
... oh, you do something similar here to what I recommend in my previous
response. I don't understand why you need the previous patch.
> + if (min_order)
> + VM_BUG_ON(index & ((1UL << order) - 1));
You don't need the 'if' here; index & ((1 << 0) - 1) becomes false.
