[PATCH v1 31/54] block: introduce bio_segments_all()

From: Ming Lei
Date: Tue Dec 27 2016 - 11:11:02 EST


There are still several direct access to .bi_vcnt, so
introduce this helper to replace that usage for supporting
multipage bvec.

Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx>
---
include/linux/bio.h | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)

diff --git a/include/linux/bio.h b/include/linux/bio.h
index efa0b3627735..b0929cf8c7fe 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -391,6 +391,27 @@ static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
bv->bv_len = iter.bi_bvec_done;
}

+/*
+ * Return how many singlepage bvecs included in this bio,
+ * and this helper is only used for some fs to replace
+ * bio->bi_vcnt.
+ */
+static inline unsigned bio_segments_all(struct bio *bio)
+{
+ unsigned segs = 0;
+ int i;
+ struct bio_vec *bv;
+ struct bvec_iter_all bia;
+
+ WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
+
+ bio_for_each_segment_all_sp(bv, bio, i, bia)
+ segs++;
+
+ return segs;
+}
+
+
enum bip_flags {
BIP_BLOCK_INTEGRITY = 1 << 0, /* block layer owns integrity data */
BIP_MAPPED_INTEGRITY = 1 << 1, /* ref tag has been remapped */
--
2.7.4