[PATCH v3 28/49] block: introduce bvec_get_last_page()

[Ming Lei]

BTRFS and guard_bio_eod() need to get the last page, so introduce
this helper to make them happy.

Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
 include/linux/bvec.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/include/linux/bvec.h b/include/linux/bvec.h
index 23d3abdf057c..ceb6292750d6 100644
--- a/include/linux/bvec.h
+++ b/include/linux/bvec.h
@@ -238,4 +238,18 @@ static inline bool bvec_iter_advance_mp(const struct bio_vec *bv,
 #define bvec_for_each_sp_bvec(sp_bvl, mp_bvec, iter)			\
 	__bvec_for_each_sp_bvec(sp_bvl, mp_bvec, iter, BVEC_ITER_ALL_INIT)
 
+/*
+ * get the last page from the multipage bvec and store it
+ * in @sp_bv
+ */
+static inline void bvec_get_last_page(struct bio_vec *mp_bv,
+				      struct bio_vec *sp_bv)
+{
+	struct bvec_iter iter;
+
+	*sp_bv = *mp_bv;
+	bvec_for_each_sp_bvec(*sp_bv, mp_bv, iter)
+		;
+}
+
 #endif /* __LINUX_BVEC_ITER_H */
-- 
2.9.4