On Wed, May 29, 2024 at 03:45:01PM +0200, Pankaj Raghav (Samsung) wrote:
> @@ -1919,8 +1921,10 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index,
> folio_wait_stable(folio);
> no_page:
> if (!folio && (fgp_flags & FGP_CREAT)) {
> - unsigned order = FGF_GET_ORDER(fgp_flags);
> + unsigned int min_order = mapping_min_folio_order(mapping);
> + unsigned int order = max(min_order, FGF_GET_ORDER(fgp_flags));
> int err;
> + index = mapping_align_start_index(mapping, index);
>
> if ((fgp_flags & FGP_WRITE) && mapping_can_writeback(mapping))
> gfp |= __GFP_WRITE;
> @@ -1958,7 +1962,7 @@ struct folio *__filemap_get_folio(struct address_space *mapping, pgoff_t index,
> break;
> folio_put(folio);
> folio = NULL;
> - } while (order-- > 0);
> + } while (order-- > min_order);
I'd argue you also need to change:
- if (order > 0)
+ if (order > min_order)
alloc_gfp |= __GFP_NORETRY | __GFP_NOWARN;
since that is the last point at which we can fall back. If we can't
immediately allocate a min_order folio, we want to retry, and we
want to warn if we can't get it.
