From 735d381fa57c573935d35a24ea271ec99897ac63 Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Mon, 10 Jun 2013 17:42:25 +0200 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- drivers/net/team/team.c | 20 +++++--------------- drivers/net/team/team_mode_loadbalance.c | 3 +-- drivers/net/team/team_mode_roundrobin.c | 3 ++- include/linux/if_team.h | 10 ++++++++++ 4 files changed, 18 insertions(+), 18 deletions(-) diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c index 488ed4f535e5..e46fef38685b 100644 --- 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 cdc31b5ea15e..829a9cd2b4da 100644 --- 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 d268e4de781b..90311c7375fb 100644 --- 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 705459524706..b662045a81c0 100644 --- 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) { -- GitLab