@@ -460,10 +460,11 @@ static int __switchdev_handle_port_obj_add(struct net_device *dev,
extack = switchdev_notifier_info_to_extack(&port_obj_info->info);
if (check_cb(dev)) {
- /* This flag is only checked if the return value is success. */
- port_obj_info->handled = true;
- return add_cb(dev, port_obj_info->obj, port_obj_info->trans,
- extack);
+ err = add_cb(dev, port_obj_info->obj, port_obj_info->trans,
+ extack);
+ if (err != -EOPNOTSUPP)
+ port_obj_info->handled = true;
+ return err;
}
/* Switch ports might be stacked under e.g. a LAG. Ignore the
@@ -515,9 +516,10 @@ static int __switchdev_handle_port_obj_del(struct net_device *dev,
int err = -EOPNOTSUPP;
if (check_cb(dev)) {
- /* This flag is only checked if the return value is success. */
- port_obj_info->handled = true;
- return del_cb(dev, port_obj_info->obj);
+ err = del_cb(dev, port_obj_info->obj);
+ if (err != -EOPNOTSUPP)
+ port_obj_info->handled = true;
+ return err;
}
/* Switch ports might be stacked under e.g. a LAG. Ignore the
@@ -568,9 +570,10 @@ static int __switchdev_handle_port_attr_set(struct net_device *dev,
int err = -EOPNOTSUPP;
if (check_cb(dev)) {
- port_attr_info->handled = true;
- return set_cb(dev, port_attr_info->attr,
- port_attr_info->trans);
+ err = set_cb(dev, port_attr_info->attr, port_attr_info->trans);
+ if (err != -EOPNOTSUPP)
+ port_attr_info->handled = true;
+ return err;
}
/* Switch ports might be stacked under e.g. a LAG. Ignore the
It's not true that switchdev_port_obj_notify() only inspects the ->handled field of "struct switchdev_notifier_port_obj_info" if call_switchdev_blocking_notifiers() returns 0 - there's a WARN_ON() triggering for a non-zero return combined with ->handled not being true. But the real problem here is that -EOPNOTSUPP is not being properly handled. The wrapper functions switchdev_handle_port_obj_add() et al change a return value of -EOPNOTSUPP to 0, and the treatment of ->handled in switchdev_port_obj_notify() seems to be designed to change that back to -EOPNOTSUPP in case nobody actually acted on the notifier (i.e., everybody returned -EOPNOTSUPP). Currently, as soon as some device down the stack passes the check_cb() check, ->handled gets set to true, which means that switchdev_port_obj_notify() cannot actually ever return -EOPNOTSUPP. This, for example, means that the detection of hardware offload support in the MRP code is broken: switchdev_port_obj_add() used by br_mrp_switchdev_send_ring_test() always returns 0, so since the MRP code thinks the generation of MRP test frames has been offloaded, no such frames are actually put on the wire. Similarly, br_mrp_switchdev_set_ring_role() also always returns 0, causing mrp->ring_role_offloaded to be set to 1. To fix this, continue to set ->handled true if any callback returns success or any error distinct from -EOPNOTSUPP. But if all the callbacks return -EOPNOTSUPP, make sure that ->handled stays false, so the logic in switchdev_port_obj_notify() can propagate that information. Fixes: f30f0601eb93 ("switchdev: Add helpers to aid traversal through lower devices") Reviewed-by: Petr Machata <petrm@nvidia.com> Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk> --- v2: reword commit message to make it more accurate; include Petr's R-b. net/switchdev/switchdev.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-)