bio: add bvec_length(), like iov_length()

Signed-off-by: Zach Brown <zach.brown@oracle.com>

diff --git a/include/linux/bio.h b/include/linux/bio.h
index ce33e6868a2f57116ae76510f4dc5de183c2b8fd..428058f6cb953e89ce4be21431a52b60cdce8088 100644 (file)
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -268,6 +268,14 @@ extern struct bio_vec *bvec_alloc_bs(gfp_t, int, unsigned long *, struct bio_set
 extern void bvec_free_bs(struct bio_set *, struct bio_vec *, unsigned int);
 extern unsigned int bvec_nr_vecs(unsigned short idx);
 
+static inline ssize_t bvec_length(const struct bio_vec *bvec, unsigned long nr)
+{
+       ssize_t bytes = 0;
+       while (nr--)
+               bytes += (bvec++)->bv_len;
+       return bytes;
+}
+
 /*
  * Allow queuer to specify a completion CPU for this bio
  */