[PATCH 13/15] block: add helper function for iteration of bip's bvec

[Jinyoung CHOI]

bip_for_each_vec() performs the iteration in a page unit.

Since a bio_vec of bip is composed of multi-page in the block, a macro
that can be carried out in multi-page units has been added.

Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>

Signed-off-by: Jinyoung Choi <j-young.choi@xxxxxxxxxxx>
---
 include/linux/bio.h  | 4 ++++
 include/linux/bvec.h | 6 ++++++
 2 files changed, 10 insertions(+)

diff --git a/include/linux/bio.h b/include/linux/bio.h
index b53a595b519a..e3e437ce694c 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -695,6 +695,10 @@ static inline bool bioset_initialized(struct bio_set *bs)
 
 #if defined(CONFIG_BLK_DEV_INTEGRITY)
 
+/* iterate over multi-page bvec for integrity */
+#define bip_for_each_mp_bvec(bvl, bip, iter)				\
+	for_each_mp_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
+
 #define bip_for_each_vec(bvl, bip, iter)				\
 	for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
 
diff --git a/include/linux/bvec.h b/include/linux/bvec.h
index 555aae5448ae..9364c258513e 100644
--- a/include/linux/bvec.h
+++ b/include/linux/bvec.h
@@ -184,6 +184,12 @@ static inline void bvec_iter_advance_single(const struct bio_vec *bv,
 		((bvl = bvec_iter_bvec((bio_vec), (iter))), 1);	\
 	     bvec_iter_advance_single((bio_vec), &(iter), (bvl).bv_len))
 
+#define for_each_mp_bvec(bvl, bio_vec, iter, start)			\
+	for (iter = (start);						\
+	     (iter).bi_size &&						\
+		((bvl = mp_bvec_iter_bvec((bio_vec), (iter))), 1);	\
+	     bvec_iter_advance_single((bio_vec), &(iter), (bvl).bv_len))
+
 /* for iterating one bio from start to end */
 #define BVEC_ITER_ALL_INIT (struct bvec_iter)				\
 {									\
-- 
2.34.1