On Thu, Nov 03, 2022 at 09:33:28PM +0000, David Howells wrote:
> +++ b/fs/netfs/buffered_read.c
> @@ -46,10 +46,15 @@ void netfs_rreq_unlock_folios(struct netfs_io_request *rreq)
>
> rcu_read_lock();
> xas_for_each(&xas, folio, last_page) {
> - unsigned int pgpos = (folio_index(folio) - start_page) * PAGE_SIZE;
> - unsigned int pgend = pgpos + folio_size(folio);
> + unsigned int pgpos, pgend;
"unsigned int" assumes that the number of bytes isn't going to exceed 32
bits. I tend to err on the side of safety here and use size_t.
> bool pg_failed = false;
>
> + if (xas_retry(&xas, folio))
> + continue;
> +
> + pgpos = (folio_index(folio) - start_page) * PAGE_SIZE;
> + pgend = pgpos + folio_size(folio);
What happens if start_page is somewhere inside folio? Seems to me
that pgend ends up overhanging into the next folio?
