Re: [PATCH v6 04/20] fs: buffer: use __bio_add_page to add single page to bio

[Gou Hao <gouhao@uniontech.com>]

On 5/30/23 23:49, Johannes Thumshirn wrote:

> The buffer_head submission code uses bio_add_page() to add a page to a
> newly created bio. bio_add_page() can fail, but the return value is never
> checked.
>
> Use __bio_add_page() as adding a single page to a newly created bio is
> guaranteed to succeed.
>
> This brings us a step closer to marking bio_add_page() as __must_check.
>
> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>


Reviewed-by: Gou Hao <gouhao@uniontech.com>

> ---
>   fs/buffer.c | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/fs/buffer.c b/fs/buffer.c
> index a7fc561758b1..63da30ce946a 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -2760,8 +2760,7 @@ static void submit_bh_wbc(blk_opf_t opf, struct buffer_head *bh,
>   
>   	bio->bi_iter.bi_sector = bh->b_blocknr * (bh->b_size >> 9);
>   
> -	bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh));
> -	BUG_ON(bio->bi_iter.bi_size != bh->b_size);
> +	__bio_add_page(bio, bh->b_page, bh->b_size, bh_offset(bh));
>   
>   	bio->bi_end_io = end_bio_bh_io_sync;
>   	bio->bi_private = bh;