net: devlink: remove redundant rtnl lock assert

It is enough for caller of devlink_compat_switch_id_get() to hold the net device to guarantee that devlink port is not destroyed concurrently. Remove rtnl lock assertion and modify comment to warn user that they must hold either rtnl lock or reference to net device. This is necessary to accommodate future implementation of rtnl-unlocked TC offloads driver callbacks. Signed-off-by: Vlad Buslov <[email protected]> Acked-by: Jiri Pirko <[email protected]> Signed-off-by: Jakub Kicinski <[email protected]>
adn770 · Aug 13, 2019 · 043b841 · 043b841
1 parent 708852d
commit 043b841
Showing 1 changed file with 2 additions and 3 deletions.
diff --git a/net/core/devlink.c b/net/core/devlink.c
@@ -6939,11 +6939,10 @@ int devlink_compat_switch_id_get(struct net_device *dev,
 {
 	struct devlink_port *devlink_port;
 
-	/* RTNL mutex is held here which ensures that devlink_port
-	 * instance cannot disappear in the middle. No need to take
+	/* Caller must hold RTNL mutex or reference to dev, which ensures that
+	 * devlink_port instance cannot disappear in the middle. No need to take
 	 * any devlink lock as only permanent values are accessed.
 	 */
-	ASSERT_RTNL();
 	devlink_port = netdev_to_devlink_port(dev);
 	if (!devlink_port || !devlink_port->attrs.switch_port)
 		return -EOPNOTSUPP;