rbd: assume single op in a request

We now know that every of rbd_req_sync_op() passes an array of
exactly one operation, as evidenced by all callers passing 1 as its
num_op argument.  So get rid of that argument, assuming a single op.

Similarly, we now know that all callers of rbd_do_request() pass 1
as the num_op value, so that parameter can be eliminated as well.

Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

drivers/block/rbd.c

@@ -1113,8 +1113,7 @@ static int rbd_do_request(struct request *rq,
 			  struct page **pages,
 			  int num_pages,
 			  int flags,
-			  unsigned int num_op,
-			  struct ceph_osd_req_op *ops,
+			  struct ceph_osd_req_op *op,
 			  struct rbd_req_coll *coll,
 			  int coll_index,
 			  void (*rbd_cb)(struct ceph_osd_request *,
@@ -1143,7 +1142,7 @@ static int rbd_do_request(struct request *rq,
 		(unsigned long long) len, coll, coll_index);
 
 	osdc = &rbd_dev->rbd_client->client->osdc;
-	osd_req = ceph_osdc_alloc_request(osdc, snapc, num_op, false, GFP_NOIO);
+	osd_req = ceph_osdc_alloc_request(osdc, snapc, 1, false, GFP_NOIO);
 	if (!osd_req) {
 		ret = -ENOMEM;
 		goto done_pages;
@@ -1169,10 +1168,10 @@ static int rbd_do_request(struct request *rq,
 
 	rbd_layout_init(&osd_req->r_file_layout, rbd_dev->spec->pool_id);
 	ret = ceph_calc_raw_layout(&osd_req->r_file_layout,
-				ofs, &len, &bno, osd_req, ops);
+				ofs, &len, &bno, osd_req, op);
 	rbd_assert(ret == 0);
 
-	ceph_osdc_build_request(osd_req, ofs, len, num_op, ops,
+	ceph_osdc_build_request(osd_req, ofs, len, 1, op,
 				snapc, snapid, &mtime);
 
 	if (linger_req) {
@@ -1255,8 +1254,7 @@ static void rbd_simple_req_cb(struct ceph_osd_request *osd_req,
  */
 static int rbd_req_sync_op(struct rbd_device *rbd_dev,
 			   int flags,
-			   unsigned int num_op,
-			   struct ceph_osd_req_op *ops,
+			   struct ceph_osd_req_op *op,
 			   const char *object_name,
 			   u64 ofs, u64 inbound_size,
 			   char *inbound,
@@ -1267,7 +1265,7 @@ static int rbd_req_sync_op(struct rbd_device *rbd_dev,
 	struct page **pages;
 	int num_pages;
 
-	rbd_assert(ops != NULL);
+	rbd_assert(op != NULL);
 
 	num_pages = calc_pages_for(ofs, inbound_size);
 	pages = ceph_alloc_page_vector(num_pages, GFP_KERNEL);
@@ -1278,7 +1276,7 @@ static int rbd_req_sync_op(struct rbd_device *rbd_dev,
 			  object_name, ofs, inbound_size, NULL,
 			  pages, num_pages,
 			  flags,
-			  num_op, ops,
+			  op,
 			  NULL, 0,
 			  NULL,
 			  linger_req, ver);
@@ -1348,7 +1346,7 @@ static int rbd_do_op(struct request *rq,
 			     bio,
 			     NULL, 0,
 			     flags,
-			     1, op,
+			     op,
 			     coll, coll_index,
 			     rbd_req_cb, 0, NULL);
 	if (ret < 0)
@@ -1377,7 +1375,7 @@ static int rbd_req_sync_read(struct rbd_device *rbd_dev,
 		return -ENOMEM;
 
 	ret = rbd_req_sync_op(rbd_dev, CEPH_OSD_FLAG_READ,
-			       1, op, object_name, ofs, len, buf, NULL, ver);
+			       op, object_name, ofs, len, buf, NULL, ver);
 	rbd_destroy_op(op);
 
 	return ret;
@@ -1405,7 +1403,7 @@ static int rbd_req_sync_notify_ack(struct rbd_device *rbd_dev,
 			  rbd_dev->header_name, 0, 0, NULL,
 			  NULL, 0,
 			  CEPH_OSD_FLAG_READ,
-			  1, op,
+			  op,
 			  NULL, 0,
 			  rbd_simple_req_cb, 0, NULL);
 
@@ -1457,7 +1455,7 @@ static int rbd_req_sync_watch(struct rbd_device *rbd_dev)
 
 	ret = rbd_req_sync_op(rbd_dev,
 			      CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
-			      1, op,
+			      op,
 			      rbd_dev->header_name,
 			      0, 0, NULL,
 			      &rbd_dev->watch_request, NULL);
@@ -1494,7 +1492,7 @@ static int rbd_req_sync_unwatch(struct rbd_device *rbd_dev)
 
 	ret = rbd_req_sync_op(rbd_dev,
 			      CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK,
-			      1, op,
+			      op,
 			      rbd_dev->header_name,
 			      0, 0, NULL, NULL, NULL);
 
@@ -1545,7 +1543,7 @@ static int rbd_req_sync_exec(struct rbd_device *rbd_dev,
 	op->cls.indata = outbound;
 	op->cls.indata_len = outbound_size;
 
-	ret = rbd_req_sync_op(rbd_dev, CEPH_OSD_FLAG_READ, 1, op,
+	ret = rbd_req_sync_op(rbd_dev, CEPH_OSD_FLAG_READ, op,
 			       object_name, 0, inbound_size, inbound,
 			       NULL, ver);