This helper can be used to iterate each singlepage bvec from one multipage bvec. Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx> --- include/linux/bvec.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/include/linux/bvec.h b/include/linux/bvec.h index 5c51c58fe202..7addceea9828 100644 --- a/include/linux/bvec.h +++ b/include/linux/bvec.h @@ -192,4 +192,18 @@ static inline void bvec_iter_advance_mp(const struct bio_vec *bv, .bi_bvec_done = 0, \ } +/* + * This helper iterates over the multipage bvec of @mp_bvec and + * returns each singlepage bvec via @sp_bvl. + */ +#define __bvec_for_each_sp_bvec(sp_bvl, mp_bvec, iter, start) \ + for (iter = start, \ + (iter).bi_size = (mp_bvec)->bv_len - (iter).bi_bvec_done; \ + (iter).bi_size && \ + ((sp_bvl = bvec_iter_bvec((mp_bvec), (iter))), 1); \ + bvec_iter_advance((mp_bvec), &(iter), (sp_bvl).bv_len)) + +#define bvec_for_each_sp_bvec(sp_bvl, mp_bvec, iter) \ + __bvec_for_each_sp_bvec(sp_bvl, mp_bvec, iter, BVEC_ITER_ALL_INIT) + #endif /* __LINUX_BVEC_ITER_H */ -- 2.9.4
