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, 3 insertions, 8 deletions

diff --git a/drivers/s390/block/dasd_diag.c b/drivers/s390/block/dasd_diag.c
index d32c60dbdd82..6bb9676f203e 100644
--- a/drivers/s390/block/dasd_diag.c
+++ b/drivers/s390/block/dasd_diag.c
@@ -472,14 +472,13 @@ dasd_diag_build_cp(struct dasd_device * device, struct request *req)
         struct dasd_ccw_req *cqr;
         struct dasd_diag_req *dreq;
         struct dasd_diag_bio *dbio;
-        struct bio *bio;
+        struct req_iterator iter;
         struct bio_vec *bv;
         char *dst;
         unsigned int count, datasize;
         sector_t recid, first_rec, last_rec;
         unsigned int blksize, off;
         unsigned char rw_cmd;
-        int i;
 
         if (rq_data_dir(req) == READ)
                 rw_cmd = MDSK_READ_REQ;
@@ -493,13 +492,11 @@ dasd_diag_build_cp(struct dasd_device * device, struct request *req)
         last_rec = (req->sector + req->nr_sectors - 1) >> device->s2b_shift;
         /* Check struct bio and count the number of blocks for the request. */
         count = 0;
-        rq_for_each_bio(bio, req) {
-                bio_for_each_segment(bv, bio, i) {
+        rq_for_each_segment(bv, req, iter) {
                         if (bv->bv_len & (blksize - 1))
                                 /* Fba can only do full blocks. */
                                 return ERR_PTR(-EINVAL);
                         count += bv->bv_len >> (device->s2b_shift + 9);
-                }
         }
         /* Paranoia. */
         if (count != last_rec - first_rec + 1)
@@ -516,8 +513,7 @@ dasd_diag_build_cp(struct dasd_device * device, struct request *req)
         dreq->block_count = count;
         dbio = dreq->bio;
         recid = first_rec;
-        rq_for_each_bio(bio, req) {
-                bio_for_each_segment(bv, bio, i) {
+        rq_for_each_segment(bv, req, iter) {
                         dst = page_address(bv->bv_page) + bv->bv_offset;
                         for (off = 0; off < bv->bv_len; off += blksize) {
                                 memset(dbio, 0, sizeof (struct dasd_diag_bio));
@@ -528,7 +524,6 @@ dasd_diag_build_cp(struct dasd_device * device, struct request *req)
                                 dst += blksize;
                                 recid++;
                         }
-                }
         }
         cqr->retries = DIAG_MAX_RETRIES;
         cqr->buildclk = get_clock();