On Tue, Nov 08, 2022 at 02:30:09PM +0100, Lukas Czerner wrote:
> + err = shmem_get_folio(inode, index, &folio, SGP_WRITE);
> + if (err)
> + return err;
> +
> + page = folio_file_page(folio, index);
> + if (PageHWPoison(page)) {
> + folio_unlock(folio);
> + folio_put(folio);
> + return -EIO;
> + }
> +
> + /* Write data, or zeroout the portion of the page */
> + if (data)
> + memcpy(page_address(page) + offset, data, len);
> + else
> + memset(page_address(page) + offset, 0, len);
> +
> + SetPageUptodate(page);
This is suspicious. There is no per-page Uptodate bit, there is only a
per-folio Uptodate bit. So this should be folio_mark_uptodate().
Except that you've only done one of the pages in the folio, so you
have no business setting the uptodate bit at all.
