Introduce rq_for_each_segment replacing rq_for_each_bio

Every usage of rq_for_each_bio wraps a usage of
bio_for_each_segment, so these can be combined into
rq_for_each_segment.

We define "struct req_iterator" to hold the 'bio' and 'index' that
are needed for the double iteration.

Signed-off-by: Neil Brown <neilb@suse.de>

Various compile fixes by me...

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 5 insertions, 10 deletions

diff --git a/drivers/s390/char/tape_34xx.c b/drivers/s390/char/tape_34xx.c
index 80e7a537e7d2..ea3e6a345c89 100644
--- a/drivers/s390/char/tape_34xx.c
+++ b/drivers/s390/char/tape_34xx.c
@@ -1134,21 +1134,18 @@ tape_34xx_bread(struct tape_device *device, struct request *req)
 {
         struct tape_request *request;
         struct ccw1 *ccw;
-        int count = 0, i;
+        int count = 0;
         unsigned off;
         char *dst;
         struct bio_vec *bv;
-        struct bio *bio;
+        struct req_iterator iter;
         struct tape_34xx_block_id *     start_block;
 
         DBF_EVENT(6, "xBREDid:");
 
         /* Count the number of blocks for the request. */
-        rq_for_each_bio(bio, req) {
-                bio_for_each_segment(bv, bio, i) {
-                        count += bv->bv_len >> (TAPEBLOCK_HSEC_S2B + 9);
-                }
-        }
+        rq_for_each_segment(bv, req, iter)
+                count += bv->bv_len >> (TAPEBLOCK_HSEC_S2B + 9);
 
         /* Allocate the ccw request. */
         request = tape_alloc_request(3+count+1, 8);
@@ -1175,8 +1172,7 @@ tape_34xx_bread(struct tape_device *device, struct request *req)
         ccw = tape_ccw_cc(ccw, NOP, 0, NULL);
         ccw = tape_ccw_cc(ccw, NOP, 0, NULL);
 
-        rq_for_each_bio(bio, req) {
-                bio_for_each_segment(bv, bio, i) {
+        rq_for_each_segment(bv, req, iter) {
                         dst = kmap(bv->bv_page) + bv->bv_offset;
                         for (off = 0; off < bv->bv_len;
                              off += TAPEBLOCK_HSEC_SIZE) {
@@ -1187,7 +1183,6 @@ tape_34xx_bread(struct tape_device *device, struct request *req)
                                 ccw++;
                                 dst += TAPEBLOCK_HSEC_SIZE;
                         }
-                }
         }
 
         ccw = tape_ccw_end(ccw, NOP, 0, NULL);