rbd: separate initialization of osd data

The osd data for a request is currently initialized inside
rbd_osd_req_create(), but that assumes an object request's data
belongs in the osd request's data in or data out field.

There are only three places where requests with data are set up, and
it turns out it's easier to call just the osd data init routines
directly there rather than handling it in rbd_osd_req_create().

(The real motivation here is moving toward getting rid of the
osd request in and out data fields.)

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

drivers/block/rbd.c

@@ -1344,8 +1344,6 @@ static struct ceph_osd_request *rbd_osd_req_create(
 	struct ceph_snap_context *snapc = NULL;
 	struct ceph_osd_client *osdc;
 	struct ceph_osd_request *osd_req;
-	struct ceph_osd_data *osd_data;
-	u64 offset = obj_request->offset;
 
 	if (img_request) {
 		rbd_assert(img_request->write_request == write_request);
@@ -1359,23 +1357,6 @@ static struct ceph_osd_request *rbd_osd_req_create(
 	osd_req = ceph_osdc_alloc_request(osdc, snapc, 1, false, GFP_ATOMIC);
 	if (!osd_req)
 		return NULL;	/* ENOMEM */
-	osd_data = write_request ? &osd_req->r_data_out : &osd_req->r_data_in;
-
-	rbd_assert(obj_request_type_valid(obj_request->type));
-	switch (obj_request->type) {
-	case OBJ_REQUEST_NODATA:
-		break;		/* Nothing to do */
-	case OBJ_REQUEST_BIO:
-		rbd_assert(obj_request->bio_list != NULL);
-		ceph_osd_data_bio_init(osd_data, obj_request->bio_list,
-					obj_request->length);
-		break;
-	case OBJ_REQUEST_PAGES:
-		ceph_osd_data_pages_init(osd_data, obj_request->pages,
-				obj_request->length, offset & ~PAGE_MASK,
-				false, false);
-		break;
-	}
 
 	if (write_request)
 		osd_req->r_flags = CEPH_OSD_FLAG_WRITE | CEPH_OSD_FLAG_ONDISK;
@@ -1596,6 +1577,8 @@ static int rbd_img_request_fill_bio(struct rbd_img_request *img_request,
 					 : &osd_req->r_data_in;
 		osd_req_op_extent_init(osd_req, 0, opcode, offset, length,
 						0, 0);
+		ceph_osd_data_bio_init(osd_data, obj_request->bio_list,
+					obj_request->length);
 		osd_req_op_extent_osd_data(osd_req, 0, osd_data);
 		rbd_osd_req_format(obj_request, write_request);
 
@@ -1874,6 +1857,8 @@ static int rbd_obj_method_sync(struct rbd_device *rbd_dev,
 	osd_req_op_cls_init(obj_request->osd_req, 0, CEPH_OSD_OP_CALL,
 					class_name, method_name,
 					outbound, outbound_size);
+	ceph_osd_data_pages_init(osd_data, obj_request->pages, inbound_size,
+					0, false, false);
 	osd_req_op_cls_response_data(obj_request->osd_req, 0, osd_data);
 	rbd_osd_req_format(obj_request, false);
 
@@ -2082,6 +2067,10 @@ static int rbd_obj_read_sync(struct rbd_device *rbd_dev,
 	osd_data = &obj_request->osd_req->r_data_in;
 	osd_req_op_extent_init(obj_request->osd_req, 0, CEPH_OSD_OP_READ,
 					offset, length, 0, 0);
+	ceph_osd_data_pages_init(osd_data, obj_request->pages,
+					obj_request->length,
+					obj_request->offset & ~PAGE_MASK,
+					false, false);
 	osd_req_op_extent_osd_data(obj_request->osd_req, 0, osd_data);
 	rbd_osd_req_format(obj_request, false);