bio: add bvec_length(), like iov_length()

Signed-off-by: Zach Brown <zab@zabbo.net>
Signed-off-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com>

diff --git a/include/linux/bio.h b/include/linux/bio.h
index ec48bac5b039d25cd74829b1ba4c6a1506412dec..4fd52534259697abc49023fe28a7b30cbaf1cc23 100644 (file)
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -307,6 +307,14 @@ extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
 extern void bvec_free(mempool_t *, 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;
+}
+
 #ifdef CONFIG_BLK_CGROUP
 int bio_associate_current(struct bio *bio);
 void bio_disassociate_task(struct bio *bio);