[PATCH V4 01/45] block: introduce bio helpers for converting to multipage bvec

Ming Lei
2017-12-18T12:23:21Z

The following helpers are introduced for converting current users of
direct access to bvec table, and prepares for supporting multipage bvec:

bio_pages_all()
bio_first_bvec_all()
bio_first_page_all()
bio_last_bvec_all()

All are named as bio_*_all() to following bio_for_each_segment_all(),
they can only be used on bio of !bio_flagged(bio, BIO_CLONED), that means
the whole bvec table is covered.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
include/linux/bio.h | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)

diff --git a/include/linux/bio.h b/include/linux/bio.h
index 82f0c8fd7be8..435ddf04e889 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -300,6 +300,29 @@ static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
bv->bv_len = iter.bi_bvec_done;
}

+static inline unsigned bio_pages_all(struct bio *bio)
+{
+ WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
+ return bio->bi_vcnt;
+}
+
+static inline struct bio_vec *bio_first_bvec_all(struct bio *bio)
+{
+ WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
+ return bio->bi_io_vec;
+}
+
+static inline struct page *bio_first_page_all(struct bio *bio)
+{
+ return bio_first_bvec_all(bio)->bv_page;
+}
+
+static inline struct bio_vec *bio_last_bvec_all(struct bio *bio)
+{
+ WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
+ return &bio->bi_io_vec[bio->bi_vcnt - 1];
+}
+
enum bip_flags {
BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */
BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */
--
2.9.5