Merge branch 'bridge-mrp-Add-br_mrp_unique_ifindex-function'

Horatiu Vultur says:

====================
bridge: mrp: Add br_mrp_unique_ifindex function

This patch series adds small fixes to MRP implementation.
The following are fixed in this patch series:
- now is not allow to add the same port to multiple MRP rings
- remove unused variable
- restore the port state according to the bridge state when the MRP instance
  is deleted

v2:
 - use rtnl_dereference instead of rcu_dereference in the first patch
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/switchdev.h

@@ -62,7 +62,6 @@ struct switchdev_attr {
 #if IS_ENABLED(CONFIG_BRIDGE_MRP)
 		u8 mrp_port_state;			/* MRP_PORT_STATE */
 		u8 mrp_port_role;			/* MRP_PORT_ROLE */
-		u8 mrp_ring_state;			/* MRP_RING_STATE */
 #endif
 	} u;
 };

net/bridge/br_mrp.c

@@ -37,6 +37,26 @@ static struct br_mrp *br_mrp_find_id(struct net_bridge *br, u32 ring_id)
 	return res;
 }
 
+static bool br_mrp_unique_ifindex(struct net_bridge *br, u32 ifindex)
+{
+	struct br_mrp *mrp;
+
+	list_for_each_entry_rcu(mrp, &br->mrp_list, list,
+				lockdep_rtnl_is_held()) {
+		struct net_bridge_port *p;
+
+		p = rtnl_dereference(mrp->p_port);
+		if (p && p->dev->ifindex == ifindex)
+			return false;
+
+		p = rtnl_dereference(mrp->s_port);
+		if (p && p->dev->ifindex == ifindex)
+			return false;
+	}
+
+	return true;
+}
+
 static struct br_mrp *br_mrp_find_port(struct net_bridge *br,
 				       struct net_bridge_port *p)
 {
@@ -203,6 +223,7 @@ static void br_mrp_test_work_expired(struct work_struct *work)
 static void br_mrp_del_impl(struct net_bridge *br, struct br_mrp *mrp)
 {
 	struct net_bridge_port *p;
+	u8 state;
 
 	/* Stop sending MRP_Test frames */
 	cancel_delayed_work_sync(&mrp->test_work);
@@ -214,20 +235,24 @@ static void br_mrp_del_impl(struct net_bridge *br, struct br_mrp *mrp)
 	p = rtnl_dereference(mrp->p_port);
 	if (p) {
 		spin_lock_bh(&br->lock);
-		p->state = BR_STATE_FORWARDING;
+		state = netif_running(br->dev) ?
+				BR_STATE_FORWARDING : BR_STATE_DISABLED;
+		p->state = state;
 		p->flags &= ~BR_MRP_AWARE;
 		spin_unlock_bh(&br->lock);
-		br_mrp_port_switchdev_set_state(p, BR_STATE_FORWARDING);
+		br_mrp_port_switchdev_set_state(p, state);
 		rcu_assign_pointer(mrp->p_port, NULL);
 	}
 
 	p = rtnl_dereference(mrp->s_port);
 	if (p) {
 		spin_lock_bh(&br->lock);
-		p->state = BR_STATE_FORWARDING;
+		state = netif_running(br->dev) ?
+				BR_STATE_FORWARDING : BR_STATE_DISABLED;
+		p->state = state;
 		p->flags &= ~BR_MRP_AWARE;
 		spin_unlock_bh(&br->lock);
-		br_mrp_port_switchdev_set_state(p, BR_STATE_FORWARDING);
+		br_mrp_port_switchdev_set_state(p, state);
 		rcu_assign_pointer(mrp->s_port, NULL);
 	}
 
@@ -255,6 +280,11 @@ int br_mrp_add(struct net_bridge *br, struct br_mrp_instance *instance)
 	    !br_mrp_get_port(br, instance->s_ifindex))
 		return -EINVAL;
 
+	/* It is not possible to have the same port part of multiple rings */
+	if (!br_mrp_unique_ifindex(br, instance->p_ifindex) ||
+	    !br_mrp_unique_ifindex(br, instance->s_ifindex))
+		return -EINVAL;
+
 	mrp = kzalloc(sizeof(*mrp), GFP_KERNEL);
 	if (!mrp)
 		return -ENOMEM;