On 1/23/23 21:59, Christoph Hellwig wrote:

On Mon, Jan 23, 2023 at 06:42:28PM -0800, John Hubbard wrote:

quoted

quoted

@@ -202,7 +202,7 @@ static void iomap_dio_zero(const struct iomap_iter *iter, struct iomap_dio *dio,
  	bio->bi_private = dio;
  	bio->bi_end_io = iomap_dio_bio_end_io;
-	get_page(page);
+	bio_set_flag(bio, BIO_NO_PAGE_REF);

...is it accurate to assume that the entire bio is pointing to the zero
page? I recall working through this area earlier last year, and ended up
just letting the zero page get pinned, and then unpinning upon release,
which is harmless.

Yes, the bio is built 4 lines above what is quoted here, and submitted
right after it.  It only contains the ZERO_PAGE.

OK, yes. All good, then.

thanks,
-- 
John Hubbard
NVIDIA