ocfs2: Proper cleanup in case of error in ocfs2_register_hb_callbacks()

If ocfs2_register_hb_callbacks() succeeds on its first callback but fails
its second, it doesn't release the first on the way out. Fix that.

While we're at it, o2hb_unregister_callback() never returns anything but
0, so let's make it void.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

fs/ocfs2/cluster/heartbeat.c

@@ -1682,23 +1682,21 @@ int o2hb_register_callback(struct o2hb_callback_func *hc)
 }
 EXPORT_SYMBOL_GPL(o2hb_register_callback);
 
-int o2hb_unregister_callback(struct o2hb_callback_func *hc)
+void o2hb_unregister_callback(struct o2hb_callback_func *hc)
 {
 	BUG_ON(hc->hc_magic != O2HB_CB_MAGIC);
 
 	mlog(ML_HEARTBEAT, "on behalf of %p for funcs %p\n",
 	     __builtin_return_address(0), hc);
 
 	if (list_empty(&hc->hc_item))
-		return 0;
+		return;
 
 	down_write(&o2hb_callback_sem);
 
 	list_del_init(&hc->hc_item);
 
 	up_write(&o2hb_callback_sem);
-
-	return 0;
 }
 EXPORT_SYMBOL_GPL(o2hb_unregister_callback);
 

fs/ocfs2/cluster/heartbeat.h

@@ -70,7 +70,7 @@ void o2hb_setup_callback(struct o2hb_callback_func *hc,
 			 void *data,
 			 int priority);
 int o2hb_register_callback(struct o2hb_callback_func *hc);
-int o2hb_unregister_callback(struct o2hb_callback_func *hc);
+void o2hb_unregister_callback(struct o2hb_callback_func *hc);
 void o2hb_fill_node_map(unsigned long *map,
 			unsigned bytes);
 void o2hb_init(void);

fs/ocfs2/cluster/tcp.c

@@ -1638,17 +1638,8 @@ static void o2net_hb_node_up_cb(struct o2nm_node *node, int node_num,
 
 void o2net_unregister_hb_callbacks(void)
 {
-	int ret;
-
-	ret = o2hb_unregister_callback(&o2net_hb_up);
-	if (ret < 0)
-		mlog(ML_ERROR, "Status return %d unregistering heartbeat up "
-		     "callback!\n", ret);
-
-	ret = o2hb_unregister_callback(&o2net_hb_down);
-	if (ret < 0)
-		mlog(ML_ERROR, "Status return %d unregistering heartbeat down "
-		     "callback!\n", ret);
+	o2hb_unregister_callback(&o2net_hb_up);
+	o2hb_unregister_callback(&o2net_hb_down);
 }
 
 int o2net_register_hb_callbacks(void)

fs/ocfs2/heartbeat.c

@@ -164,27 +164,22 @@ int ocfs2_register_hb_callbacks(struct ocfs2_super *osb)
 	}
 
 	status = o2hb_register_callback(&osb->osb_hb_up);
-	if (status < 0)
+	if (status < 0) {
 		mlog_errno(status);
+		o2hb_unregister_callback(&osb->osb_hb_down);
+	}
 
 bail:
 	return status;
 }
 
 void ocfs2_clear_hb_callbacks(struct ocfs2_super *osb)
 {
-	int status;
-
 	if (ocfs2_mount_local(osb))
 		return;
 
-	status = o2hb_unregister_callback(&osb->osb_hb_down);
-	if (status < 0)
-		mlog_errno(status);
-
-	status = o2hb_unregister_callback(&osb->osb_hb_up);
-	if (status < 0)
-		mlog_errno(status);
+	o2hb_unregister_callback(&osb->osb_hb_down);
+	o2hb_unregister_callback(&osb->osb_hb_up);
 }
 
 void ocfs2_stop_heartbeat(struct ocfs2_super *osb)