block: Clean up the code used to generate and verify integrity metadata

Instead of the "operate" parameter we pass in a seed value and a pointer
to a function that can be used to process the integrity metadata. The
generation function is changed to have a return value to fit into this
scheme.

Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 448d8c0..3fd3666 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -322,6 +322,18 @@
 	struct bio_vec		*bip_vec;
 	struct bio_vec		bip_inline_vecs[0];/* embedded bvec array */
 };
+
+static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
+{
+	return bip->bip_iter.bi_sector;
+}
+
+static inline void bip_set_seed(struct bio_integrity_payload *bip,
+				sector_t seed)
+{
+	bip->bip_iter.bi_sector = seed;
+}
+
 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 
 extern void bio_trim(struct bio *bio, int offset, int size);