team: remove synchronize_rcu() called during port disable

Check the unlikely case of team->en_port_count == 0 before modulo
operation.

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c
index 488ed4f..e46fef3 100644 (file)
--- a/drivers/net/team/team.c
+++ b/drivers/net/team/team.c
@@ -525,31 +525,26 @@ static void team_set_no_mode(struct team *team)
        team->mode = &__team_no_mode;
 }
 
-static void __team_adjust_ops(struct team *team, int en_port_count)
+static void team_adjust_ops(struct team *team)
 {
        /*
         * To avoid checks in rx/tx skb paths, ensure here that non-null and
         * correct ops are always set.
         */
 
-       if (!en_port_count || !team_is_mode_set(team) ||
+       if (!team->en_port_count || !team_is_mode_set(team) ||
            !team->mode->ops->transmit)
                team->ops.transmit = team_dummy_transmit;
        else
                team->ops.transmit = team->mode->ops->transmit;
 
-       if (!en_port_count || !team_is_mode_set(team) ||
+       if (!team->en_port_count || !team_is_mode_set(team) ||
            !team->mode->ops->receive)
                team->ops.receive = team_dummy_receive;
        else
                team->ops.receive = team->mode->ops->receive;
 }
 
-static void team_adjust_ops(struct team *team)
-{
-       __team_adjust_ops(team, team->en_port_count);
-}
-
 /*
  * We can benefit from the fact that it's ensured no port is present
  * at the time of mode change. Therefore no packets are in fly so there's no
@@ -877,14 +872,9 @@ static void team_port_disable(struct team *team,
        hlist_del_rcu(&port->hlist);
        __reconstruct_port_hlist(team, port->index);
        port->index = -1;
-       team_queue_override_port_del(team, port);
-       __team_adjust_ops(team, team->en_port_count - 1);
-       /*
-        * Wait until readers see adjusted ops. This ensures that
-        * readers never see team->en_port_count == 0
-        */
-       synchronize_rcu();
        team->en_port_count--;
+       team_queue_override_port_del(team, port);
+       team_adjust_ops(team);
 }
 
 #define TEAM_VLAN_FEATURES (NETIF_F_ALL_CSUM | NETIF_F_SG | \

diff --git a/drivers/net/team/team_mode_loadbalance.c b/drivers/net/team/team_mode_loadbalance.c
index cdc31b5..829a9cd 100644 (file)
--- a/drivers/net/team/team_mode_loadbalance.c
+++ b/drivers/net/team/team_mode_loadbalance.c
@@ -112,9 +112,8 @@ static struct team_port *lb_hash_select_tx_port(struct team *team,
                                                struct sk_buff *skb,
                                                unsigned char hash)
 {
-       int port_index;
+       int port_index = team_num_to_port_index(team, hash);
 
-       port_index = hash % team->en_port_count;
        return team_get_port_by_index_rcu(team, port_index);
 }
 

diff --git a/drivers/net/team/team_mode_roundrobin.c b/drivers/net/team/team_mode_roundrobin.c
index d268e4d..90311c7 100644 (file)
--- a/drivers/net/team/team_mode_roundrobin.c
+++ b/drivers/net/team/team_mode_roundrobin.c
@@ -30,7 +30,8 @@ static bool rr_transmit(struct team *team, struct sk_buff *skb)
        struct team_port *port;
        int port_index;
 
-       port_index = rr_priv(team)->sent_packets++ % team->en_port_count;
+       port_index = team_num_to_port_index(team,
+                                           rr_priv(team)->sent_packets++);
        port = team_get_port_by_index_rcu(team, port_index);
        port = team_get_first_port_txable_rcu(team, port);
        if (unlikely(!port))

diff --git a/include/linux/if_team.h b/include/linux/if_team.h
index 7054595..b662045 100644 (file)
--- a/include/linux/if_team.h
+++ b/include/linux/if_team.h
@@ -229,6 +229,16 @@ static inline struct team_port *team_get_port_by_index(struct team *team,
                        return port;
        return NULL;
 }
+
+static inline int team_num_to_port_index(struct team *team, int num)
+{
+       int en_port_count = ACCESS_ONCE(team->en_port_count);
+
+       if (unlikely(!en_port_count))
+               return 0;
+       return num % en_port_count;
+}
+
 static inline struct team_port *team_get_port_by_index_rcu(struct team *team,
                                                           int port_index)
 {