On Fri, May 25, 2018 at 11:46:00AM +0800, Ming Lei wrote:
> There are still cases in which we need to use bio_segments() for get the
> number of segment, so introduce it.
>
> Signed-off-by: Ming Lei <ming....@redhat.com>
> ---
> include/linux/bio.h | 25 ++++++++++++++++++++-----
> 1 file changed, 20 insertions(+), 5 deletions(-)
>
> diff --git a/include/linux/bio.h b/include/linux/bio.h
> index 08af9272687f..b24c00f99c9c 100644
> --- a/include/linux/bio.h
> +++ b/include/linux/bio.h
> @@ -227,9 +227,9 @@ static inline bool bio_rewind_iter(struct bio *bio,
> struct bvec_iter *iter,
>
> #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
>
> -static inline unsigned bio_pages(struct bio *bio)
> +static inline unsigned __bio_elements(struct bio *bio, bool seg)
This is a rather silly helper function, there isn't any actual code that's
shared, everything's behind an if () statement. Just open code it in bio_pages()
and bio_segments()
> {
> - unsigned segs = 0;
> + unsigned elems = 0;
> struct bio_vec bv;
> struct bvec_iter iter;
>
> @@ -249,10 +249,25 @@ static inline unsigned bio_pages(struct bio *bio)
> break;
> }
>
> - bio_for_each_page(bv, bio, iter)
> - segs++;
> + if (!seg) {
> + bio_for_each_page(bv, bio, iter)
> + elems++;
> + } else {
> + bio_for_each_segment(bv, bio, iter)
> + elems++;
> + }
> +
> + return elems;
> +}
> +
> +static inline unsigned bio_pages(struct bio *bio)
> +{
> + return __bio_elements(bio, false);
> +}
>
> - return segs;
> +static inline unsigned bio_segments(struct bio *bio)
> +{
> + return __bio_elements(bio, true);
> }
>
> /*
> --
> 2.9.5
>
