[PATCH V12 08/20] block: introduce bio_for_each_bvec() and rq_for_each_bvec()
From: Ming Lei <hidden>
Date: 2018-11-26 02:17:08
Also in:
dm-devel, linux-bcache, linux-block, linux-btrfs, linux-ext4, linux-fsdevel, linux-mm, linux-xfs, lkml
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
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: Omar Sandoval <redacted> Signed-off-by: Ming Lei <redacted> --- include/linux/bio.h | 10 ++++++++++ include/linux/blkdev.h | 4 ++++ include/linux/bvec.h | 7 +++++++ 3 files changed, 21 insertions(+)
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 6a0ff02f4d1c..46fd0e03233b 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 = 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 399a7a415609..fa263de3f1d1 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h@@ -799,6 +799,10 @@ 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))
diff --git a/include/linux/bvec.h b/include/linux/bvec.h
index babc6316c117..d441486db605 100644
--- a/include/linux/bvec.h
+++ b/include/linux/bvec.h@@ -65,6 +65,13 @@ struct bvec_iter { #define bvec_iter_page_idx(bvec, iter) \ (bvec_iter_offset((bvec), (iter)) / PAGE_SIZE) +#define bvec_iter_bvec(bvec, iter) \ +((struct bio_vec) { \ + .bv_page = bvec_iter_page((bvec), (iter)), \ + .bv_len = bvec_iter_len((bvec), (iter)), \ + .bv_offset = bvec_iter_offset((bvec), (iter)), \ +}) + /* For building single-page bvec(segment) in flight */ #define segment_iter_offset(bvec, iter) \ (bvec_iter_offset((bvec), (iter)) % PAGE_SIZE)
--
2.9.5