On Wed, Aug 07, 2024 at 04:28:53PM GMT, Matthew Wilcox wrote:
> On Tue, Jul 30, 2024 at 01:39:06PM -0700, Andrii Nakryiko wrote:
> > + union {
> > + struct {
> > + struct address_space *mapping;
> > + struct page *page;
>
> NAK. All the page-based interfaces are deprecated. Only we can't mark
> them as deprecated because our tooling is a pile of crap.
>
> > + void *page_addr;
> > + u64 file_off;
>
> loff_t pos.
>
> > + r->page = find_get_page(r->mapping, pg_off);
>
> r->folio = read_mapping_folio(r->mapping, r->pos / PAGE_SIZE, ...)
>
> OK, for network filesystems, you're going to need to retain the struct
> file that's used to access them. So maybe this becomes
> read_mapping_folio(r->file->f_mapping, r->pos, r->file)
This code path can be called from non-sleepable context. What would be
the appropriate way to get the folio in that case?
>
> > + r->page_addr = kmap_local_page(r->page);
>
> kmap_local_folio(r->folio, offset_in_folio(r->folio, r->pos));
>
