ceph: drop redundant r_mds field

The r_mds field is redundant, since we can find the same information at
r_session->s_mds, and when r_session is NULL then r_mds is meaningless.
Signed-off-by: Sage Weil <sage@newdream.net>

fs/ceph/debugfs.c

@@ -60,10 +60,13 @@ static int mdsc_show(struct seq_file *s, void *p)
 	for (rp = rb_first(&mdsc->request_tree); rp; rp = rb_next(rp)) {
 		req = rb_entry(rp, struct ceph_mds_request, r_node);
 
-		if (req->r_request)
-			seq_printf(s, "%lld\tmds%d\t", req->r_tid, req->r_mds);
-		else
+		if (req->r_request && req->r_session)
+			seq_printf(s, "%lld\tmds%d\t", req->r_tid,
+				   req->r_session->s_mds);
+		else if (!req->r_request)
 			seq_printf(s, "%lld\t(no request)\t", req->r_tid);
+		else
+			seq_printf(s, "%lld\t(no session)\t", req->r_tid);
 
 		seq_printf(s, "%s", ceph_mds_op_name(req->r_op));
 

fs/ceph/mds_client.c

@@ -1705,7 +1705,6 @@ static int __prepare_send_request(struct ceph_mds_client *mdsc,
 	struct ceph_msg *msg;
 	int flags = 0;
 
-	req->r_mds = mds;
 	req->r_attempts++;
 	if (req->r_inode) {
 		struct ceph_cap *cap =
@@ -2068,8 +2067,11 @@ static void handle_reply(struct ceph_mds_session *session, struct ceph_msg *msg)
 			goto out;
 		} else  {
 			struct ceph_inode_info *ci = ceph_inode(req->r_inode);
-			struct ceph_cap *cap =
-				ceph_get_cap_for_mds(ci, req->r_mds);;
+			struct ceph_cap *cap = NULL;
+
+			if (req->r_session)
+				cap = ceph_get_cap_for_mds(ci,
+						   req->r_session->s_mds);
 
 			dout("already using auth");
 			if ((!cap || cap != ci->i_auth_cap) ||

fs/ceph/mds_client.h

@@ -166,7 +166,6 @@ struct ceph_mds_request {
 	struct ceph_mds_client *r_mdsc;
 
 	int r_op;                    /* mds op code */
-	int r_mds;
 
 	/* operation on what? */
 	struct inode *r_inode;              /* arg1 */