On Wed, Mar 12, 2025 at 07:38:05PM +0800, Ming Lei wrote:
> +++ b/block/bio.c
> @@ -1026,9 +1026,17 @@ EXPORT_SYMBOL(bio_add_page);
> void bio_add_folio_nofail(struct bio *bio, struct folio *folio, size_t len,
> size_t off)
> {
> + struct page *page = &folio->page;
> +
> WARN_ON_ONCE(len > UINT_MAX);
> - WARN_ON_ONCE(off > UINT_MAX);
> - __bio_add_page(bio, &folio->page, len, off);
> + if (unlikely(off > UINT_MAX)) {
I think we should probably make this:
if (unlikely(off + len > UINT_MAX))
because I'm not sure that everything will cope well with an I/O that
crosses the 4GB boundary.
Actually, why bother with the conditional? Let's just do it always.
{
+ unsigned long nr = off / PAGE_SIZE;
WARN_ON_ONCE(len > UINT_MAX);
- WARN_ON_ONCE(off > UINT_MAX);
- __bio_add_page(bio, &folio->page, len, off);
+ off = off % PAGE_SIZE;
+ __bio_add_page(bio, folio_page(folio, nr), len, off);
}
Also you need to do bio_add_folio(), not just the _nofail variant.
