# \[PATCH v1 04/54\] mm: page\_io.c: comment on direct access to bvec table

- From: Ming Lei \<tom.leiming@gmail.com\>
- Date: 2016-12-27 15:59:56 
- List: linux-block
- Page: https://ratatoskr.run/linux-block/2016/12/4900944
- Thread: https://ratatoskr.run/linux-block/2016/12/4900944/t.md

```text
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
---
 mm/page_io.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/page_io.c b/mm/page_io.c
index 23f6d0d3470f..368a16aa810c 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -43,6 +43,7 @@ static struct bio *get_swap_bio(gfp_t gfp_flags,
 
 void end_swap_bio_write(struct bio *bio)
 {
+	/* single page bio, safe for multipage bvec */
 	struct page *page = bio->bi_io_vec[0].bv_page;
 
 	if (bio->bi_error) {
@@ -116,6 +117,7 @@ static void swap_slot_free_notify(struct page *page)
 
 static void end_swap_bio_read(struct bio *bio)
 {
+	/* single page bio, safe for multipage bvec */
 	struct page *page = bio->bi_io_vec[0].bv_page;
 
 	if (bio->bi_error) {
-- 
2.7.4

```