libceph: clean up osd data field access functions

There are a bunch of functions defined to encapsulate getting the
address of a data field for a particular op in an osd request.
They're all defined the same way, so create a macro to take the
place of all of them.

Two of these are used outside the osd client code, so preserve them
(but convert them to use the new macro internally).  Stop exporting
the ones that aren't used elsewhere.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

net/ceph/osd_client.c

@@ -115,43 +115,25 @@ static void ceph_osd_data_bio_init(struct ceph_osd_data *osd_data,
 }
 #endif /* CONFIG_BLOCK */
 
+#define osd_req_op_data(oreq, whch, typ, fld)	\
+	({						\
+		BUG_ON(whch >= (oreq)->r_num_ops);	\
+		&(oreq)->r_ops[whch].typ.fld;		\
+	})
+
 struct ceph_osd_data *
 osd_req_op_extent_osd_data(struct ceph_osd_request *osd_req,
 			unsigned int which)
 {
-	BUG_ON(which >= osd_req->r_num_ops);
-
-	return &osd_req->r_ops[which].extent.osd_data;
+	return osd_req_op_data(osd_req, which, extent, osd_data);
 }
 EXPORT_SYMBOL(osd_req_op_extent_osd_data);
 
-struct ceph_osd_data *
-osd_req_op_cls_request_info(struct ceph_osd_request *osd_req,
-			unsigned int which)
-{
-	BUG_ON(which >= osd_req->r_num_ops);
-
-	return &osd_req->r_ops[which].cls.request_info;
-}
-EXPORT_SYMBOL(osd_req_op_cls_request_info);	/* ??? */
-
-struct ceph_osd_data *
-osd_req_op_cls_request_data(struct ceph_osd_request *osd_req,
-			unsigned int which)
-{
-	BUG_ON(which >= osd_req->r_num_ops);
-
-	return &osd_req->r_ops[which].cls.request_data;
-}
-EXPORT_SYMBOL(osd_req_op_cls_request_data);	/* ??? */
-
 struct ceph_osd_data *
 osd_req_op_cls_response_data(struct ceph_osd_request *osd_req,
 			unsigned int which)
 {
-	BUG_ON(which >= osd_req->r_num_ops);
-
-	return &osd_req->r_ops[which].cls.response_data;
+	return osd_req_op_data(osd_req, which, cls, response_data);
 }
 EXPORT_SYMBOL(osd_req_op_cls_response_data);	/* ??? */
 
@@ -162,7 +144,7 @@ void osd_req_op_extent_osd_data_pages(struct ceph_osd_request *osd_req,
 {
 	struct ceph_osd_data *osd_data;
 
-	osd_data = osd_req_op_extent_osd_data(osd_req, which);
+	osd_data = osd_req_op_data(osd_req, which, extent, osd_data);
 	ceph_osd_data_pages_init(osd_data, pages, length, alignment,
 				pages_from_pool, own_pages);
 }
@@ -173,7 +155,7 @@ void osd_req_op_extent_osd_data_pagelist(struct ceph_osd_request *osd_req,
 {
 	struct ceph_osd_data *osd_data;
 
-	osd_data = osd_req_op_extent_osd_data(osd_req, which);
+	osd_data = osd_req_op_data(osd_req, which, extent, osd_data);
 	ceph_osd_data_pagelist_init(osd_data, pagelist);
 }
 EXPORT_SYMBOL(osd_req_op_extent_osd_data_pagelist);
@@ -183,7 +165,8 @@ void osd_req_op_extent_osd_data_bio(struct ceph_osd_request *osd_req,
 			unsigned int which, struct bio *bio, size_t bio_length)
 {
 	struct ceph_osd_data *osd_data;
-	osd_data = osd_req_op_extent_osd_data(osd_req, which);
+
+	osd_data = osd_req_op_data(osd_req, which, extent, osd_data);
 	ceph_osd_data_bio_init(osd_data, bio, bio_length);
 }
 EXPORT_SYMBOL(osd_req_op_extent_osd_data_bio);
@@ -195,7 +178,7 @@ static void osd_req_op_cls_request_info_pagelist(
 {
 	struct ceph_osd_data *osd_data;
 
-	osd_data = osd_req_op_cls_request_info(osd_req, which);
+	osd_data = osd_req_op_data(osd_req, which, cls, request_info);
 	ceph_osd_data_pagelist_init(osd_data, pagelist);
 }
 
@@ -205,7 +188,7 @@ void osd_req_op_cls_request_data_pagelist(
 {
 	struct ceph_osd_data *osd_data;
 
-	osd_data = osd_req_op_cls_request_data(osd_req, which);
+	osd_data = osd_req_op_data(osd_req, which, cls, request_data);
 	ceph_osd_data_pagelist_init(osd_data, pagelist);
 }
 EXPORT_SYMBOL(osd_req_op_cls_request_data_pagelist);
@@ -216,7 +199,7 @@ void osd_req_op_cls_response_data_pages(struct ceph_osd_request *osd_req,
 {
 	struct ceph_osd_data *osd_data;
 
-	osd_data = osd_req_op_cls_response_data(osd_req, which);
+	osd_data = osd_req_op_data(osd_req, which, cls, response_data);
 	ceph_osd_data_pages_init(osd_data, pages, length, alignment,
 				pages_from_pool, own_pages);
 }
@@ -241,7 +224,6 @@ static u64 ceph_osd_data_length(struct ceph_osd_data *osd_data)
 	}
 }
 
-
 static void ceph_osd_data_release(struct ceph_osd_data *osd_data)
 {
 	if (osd_data->type == CEPH_OSD_DATA_TYPE_PAGES && osd_data->own_pages) {