From ad48b32f708fcd382af593d2f8c1fff3fbd1db81 Mon Sep 17 00:00:00 2001 From: Pravin B Shelar Date: Thu, 6 Oct 2011 19:53:23 -0700 Subject: datapath: Fix recv path for CONFIG_PREEMPT_RCU. In case CONFIG_PREEMPT_RCU, rcu grace period waits only for RCU read-side critical sections that are delimited by rcu_read_lock() and rcu_read_unlock(). internal_dev_xmit() is called in rcu_read_lock_bh context. Therefore we need to explicitly take rcu lock to prevent race with call_rcu() in PREEMPT_RCU case. Signed-off-by: Pravin B Shelar Acked-by: Jesse Gross --- datapath/vport-internal_dev.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/datapath/vport-internal_dev.c b/datapath/vport-internal_dev.c index 5b3b2b3db..45981a87d 100644 --- a/datapath/vport-internal_dev.c +++ b/datapath/vport-internal_dev.c @@ -71,7 +71,7 @@ static int internal_dev_mac_addr(struct net_device *dev, void *p) return 0; } -/* Called with rcu_read_lock and bottom-halves disabled. */ +/* Called with rcu_read_lock_bh. */ static int internal_dev_xmit(struct sk_buff *skb, struct net_device *netdev) { if (unlikely(compute_ip_summed(skb, true))) { @@ -82,7 +82,9 @@ static int internal_dev_xmit(struct sk_buff *skb, struct net_device *netdev) vlan_copy_skb_tci(skb); OVS_CB(skb)->flow = NULL; + rcu_read_lock(); vport_receive(internal_dev_priv(netdev)->vport, skb); + rcu_read_unlock(); return 0; } -- cgit v1.2.1