| Message ID | 87d0bf7d65cb7c64a0010524e5b39466f2b79870.1680108414.git.johannes.thumshirn@wdc.com (mailing list archive) |
|---|---|
| State | Mainlined, archived |
| Headers | show |
| Series | bio: check return values of bio_add_page | expand |
On Wed, Mar 29, 2023 at 10:05:48AM -0700, Johannes Thumshirn wrote: > +++ b/drivers/block/drbd/drbd_bitmap.c > @@ -1043,9 +1043,11 @@ static void bm_page_io_async(struct drbd_bm_aio_ctx *ctx, int page_nr) __must_ho > bio = bio_alloc_bioset(device->ldev->md_bdev, 1, op, GFP_NOIO, > &drbd_md_io_bio_set); > bio->bi_iter.bi_sector = on_disk_sector; > - /* bio_add_page of a single page to an empty bio will always succeed, > - * according to api. Do we want to assert that? */ > - bio_add_page(bio, page, len, 0); > + /* > + * __bio_add_page of a single page to an empty bio will always succeed, > + * according to api. Do we want to assert that? > + */ > + __bio_add_page(bio, page, len, 0); Surely the comment should just be deleted? With no return value to check, what would you assert?
On 3/30/23 02:05, Johannes Thumshirn wrote: > The drbd code only adds a single page to a newly created bio. So use > __bio_add_page() to add the page which is guaranteed to succeed in this > case. > > This brings us closer to marking bio_add_page() as __must_check. > > Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> With Matthew comment addressed, Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
diff --git a/drivers/block/drbd/drbd_bitmap.c b/drivers/block/drbd/drbd_bitmap.c index 289876ffbc31..c542dcf8c457 100644 --- a/drivers/block/drbd/drbd_bitmap.c +++ b/drivers/block/drbd/drbd_bitmap.c @@ -1043,9 +1043,11 @@ static void bm_page_io_async(struct drbd_bm_aio_ctx *ctx, int page_nr) __must_ho bio = bio_alloc_bioset(device->ldev->md_bdev, 1, op, GFP_NOIO, &drbd_md_io_bio_set); bio->bi_iter.bi_sector = on_disk_sector; - /* bio_add_page of a single page to an empty bio will always succeed, - * according to api. Do we want to assert that? */ - bio_add_page(bio, page, len, 0); + /* + * __bio_add_page of a single page to an empty bio will always succeed, + * according to api. Do we want to assert that? + */ + __bio_add_page(bio, page, len, 0); bio->bi_private = ctx; bio->bi_end_io = drbd_bm_endio;
The drbd code only adds a single page to a newly created bio. So use __bio_add_page() to add the page which is guaranteed to succeed in this case. This brings us closer to marking bio_add_page() as __must_check. Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> --- drivers/block/drbd/drbd_bitmap.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)