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-rw-r--r--net/ipv4/ip_gre.c40
1 files changed, 23 insertions, 17 deletions
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 89ff9d5b1500..40f043915235 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -156,8 +156,13 @@ struct ipgre_net {
#define tunnels_r tunnels[2]
#define tunnels_l tunnels[1]
#define tunnels_wc tunnels[0]
+/*
+ * Locking : hash tables are protected by RCU and a spinlock
+ */
+static DEFINE_SPINLOCK(ipgre_lock);
-static DEFINE_RWLOCK(ipgre_lock);
+#define for_each_ip_tunnel_rcu(start) \
+ for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
/* Given src, dst and key, find appropriate for input tunnel. */
@@ -175,7 +180,7 @@ static struct ip_tunnel * ipgre_tunnel_lookup(struct net_device *dev,
ARPHRD_ETHER : ARPHRD_IPGRE;
int score, cand_score = 4;
- for (t = ign->tunnels_r_l[h0^h1]; t; t = t->next) {
+ for_each_ip_tunnel_rcu(ign->tunnels_r_l[h0 ^ h1]) {
if (local != t->parms.iph.saddr ||
remote != t->parms.iph.daddr ||
key != t->parms.i_key ||
@@ -200,7 +205,7 @@ static struct ip_tunnel * ipgre_tunnel_lookup(struct net_device *dev,
}
}
- for (t = ign->tunnels_r[h0^h1]; t; t = t->next) {
+ for_each_ip_tunnel_rcu(ign->tunnels_r[h0 ^ h1]) {
if (remote != t->parms.iph.daddr ||
key != t->parms.i_key ||
!(t->dev->flags & IFF_UP))
@@ -224,7 +229,7 @@ static struct ip_tunnel * ipgre_tunnel_lookup(struct net_device *dev,
}
}
- for (t = ign->tunnels_l[h1]; t; t = t->next) {
+ for_each_ip_tunnel_rcu(ign->tunnels_l[h1]) {
if ((local != t->parms.iph.saddr &&
(local != t->parms.iph.daddr ||
!ipv4_is_multicast(local))) ||
@@ -250,7 +255,7 @@ static struct ip_tunnel * ipgre_tunnel_lookup(struct net_device *dev,
}
}
- for (t = ign->tunnels_wc[h1]; t; t = t->next) {
+ for_each_ip_tunnel_rcu(ign->tunnels_wc[h1]) {
if (t->parms.i_key != key ||
!(t->dev->flags & IFF_UP))
continue;
@@ -276,8 +281,9 @@ static struct ip_tunnel * ipgre_tunnel_lookup(struct net_device *dev,
if (cand != NULL)
return cand;
- if (ign->fb_tunnel_dev->flags & IFF_UP)
- return netdev_priv(ign->fb_tunnel_dev);
+ dev = ign->fb_tunnel_dev;
+ if (dev->flags & IFF_UP)
+ return netdev_priv(dev);
return NULL;
}
@@ -311,10 +317,10 @@ static void ipgre_tunnel_link(struct ipgre_net *ign, struct ip_tunnel *t)
{
struct ip_tunnel **tp = ipgre_bucket(ign, t);
+ spin_lock_bh(&ipgre_lock);
t->next = *tp;
- write_lock_bh(&ipgre_lock);
- *tp = t;
- write_unlock_bh(&ipgre_lock);
+ rcu_assign_pointer(*tp, t);
+ spin_unlock_bh(&ipgre_lock);
}
static void ipgre_tunnel_unlink(struct ipgre_net *ign, struct ip_tunnel *t)
@@ -323,9 +329,9 @@ static void ipgre_tunnel_unlink(struct ipgre_net *ign, struct ip_tunnel *t)
for (tp = ipgre_bucket(ign, t); *tp; tp = &(*tp)->next) {
if (t == *tp) {
- write_lock_bh(&ipgre_lock);
+ spin_lock_bh(&ipgre_lock);
*tp = t->next;
- write_unlock_bh(&ipgre_lock);
+ spin_unlock_bh(&ipgre_lock);
break;
}
}
@@ -476,7 +482,7 @@ static void ipgre_err(struct sk_buff *skb, u32 info)
break;
}
- read_lock(&ipgre_lock);
+ rcu_read_lock();
t = ipgre_tunnel_lookup(skb->dev, iph->daddr, iph->saddr,
flags & GRE_KEY ?
*(((__be32 *)p) + (grehlen / 4) - 1) : 0,
@@ -494,7 +500,7 @@ static void ipgre_err(struct sk_buff *skb, u32 info)
t->err_count = 1;
t->err_time = jiffies;
out:
- read_unlock(&ipgre_lock);
+ rcu_read_unlock();
return;
}
@@ -573,7 +579,7 @@ static int ipgre_rcv(struct sk_buff *skb)
gre_proto = *(__be16 *)(h + 2);
- read_lock(&ipgre_lock);
+ rcu_read_lock();
if ((tunnel = ipgre_tunnel_lookup(skb->dev,
iph->saddr, iph->daddr, key,
gre_proto))) {
@@ -647,13 +653,13 @@ static int ipgre_rcv(struct sk_buff *skb)
ipgre_ecn_decapsulate(iph, skb);
netif_rx(skb);
- read_unlock(&ipgre_lock);
+ rcu_read_unlock();
return(0);
}
icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
drop:
- read_unlock(&ipgre_lock);
+ rcu_read_unlock();
drop_nolock:
kfree_skb(skb);
return(0);