From d18d91740ad22e9d7998884c4d80523d0ba95ddf Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Fri, 15 Feb 2019 19:13:11 +0800 Subject: [PATCH] block: introduce bio_for_each_bvec() and rq_for_each_bvec() bio_for_each_bvec() is used for iterating over multi-page bvec for bio split & merge code. rq_for_each_bvec() can be used for drivers which may handle the multi-page bvec directly, so far loop is one perfect use case. Reviewed-by: Christoph Hellwig Reviewed-by: Omar Sandoval Signed-off-by: Ming Lei Signed-off-by: Jens Axboe --- include/linux/bio.h | 10 ++++++++++ include/linux/blkdev.h | 4 ++++ 2 files changed, 14 insertions(+) diff --git a/include/linux/bio.h b/include/linux/bio.h index 72b4f7be2106..7ef8a7505c0a 100644 --- a/include/linux/bio.h +++ b/include/linux/bio.h @@ -156,6 +156,16 @@ static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter, #define bio_for_each_segment(bvl, bio, iter) \ __bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter) +#define __bio_for_each_bvec(bvl, bio, iter, start) \ + for (iter = (start); \ + (iter).bi_size && \ + ((bvl = mp_bvec_iter_bvec((bio)->bi_io_vec, (iter))), 1); \ + bio_advance_iter((bio), &(iter), (bvl).bv_len)) + +/* iterate over multi-page bvec */ +#define bio_for_each_bvec(bvl, bio, iter) \ + __bio_for_each_bvec(bvl, bio, iter, (bio)->bi_iter) + #define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len) static inline unsigned bio_segments(struct bio *bio) diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 3603270cb82d..b6292d469ea4 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -792,6 +792,10 @@ struct req_iterator { __rq_for_each_bio(_iter.bio, _rq) \ bio_for_each_segment(bvl, _iter.bio, _iter.iter) +#define rq_for_each_bvec(bvl, _rq, _iter) \ + __rq_for_each_bio(_iter.bio, _rq) \ + bio_for_each_bvec(bvl, _iter.bio, _iter.iter) + #define rq_iter_last(bvec, _iter) \ (_iter.bio->bi_next == NULL && \ bio_iter_last(bvec, _iter.iter)) -- 2.30.2