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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-03 17:40:04 +00:00
ip6tnl: convert hash tables locking to RCU
ip6_tunnels use one rwlock to protect their hash tables. This locking scheme can be converted to RCU for free, since netdevice already must wait for a RCU grace period at dismantle time. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
parent
8f95dd63a2
commit
2922bc8aed
1 changed files with 25 additions and 19 deletions
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@ -88,8 +88,10 @@ struct ip6_tnl_net {
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struct ip6_tnl **tnls[2];
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};
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/* lock for the tunnel lists */
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static DEFINE_RWLOCK(ip6_tnl_lock);
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/*
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* Locking : hash tables are protected by RCU and a spinlock
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*/
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static DEFINE_SPINLOCK(ip6_tnl_lock);
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static inline struct dst_entry *ip6_tnl_dst_check(struct ip6_tnl *t)
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{
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@ -130,6 +132,9 @@ static inline void ip6_tnl_dst_store(struct ip6_tnl *t, struct dst_entry *dst)
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* else %NULL
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**/
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#define for_each_ip6_tunnel_rcu(start) \
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for (t = rcu_dereference(start); t; t = rcu_dereference(t->next))
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static struct ip6_tnl *
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ip6_tnl_lookup(struct net *net, struct in6_addr *remote, struct in6_addr *local)
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{
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@ -138,13 +143,14 @@ ip6_tnl_lookup(struct net *net, struct in6_addr *remote, struct in6_addr *local)
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struct ip6_tnl *t;
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struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
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for (t = ip6n->tnls_r_l[h0 ^ h1]; t; t = t->next) {
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for_each_ip6_tunnel_rcu(ip6n->tnls_r_l[h0 ^ h1]) {
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if (ipv6_addr_equal(local, &t->parms.laddr) &&
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ipv6_addr_equal(remote, &t->parms.raddr) &&
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(t->dev->flags & IFF_UP))
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return t;
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}
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if ((t = ip6n->tnls_wc[0]) != NULL && (t->dev->flags & IFF_UP))
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t = rcu_dereference(ip6n->tnls_wc[0]);
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if (t && (t->dev->flags & IFF_UP))
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return t;
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return NULL;
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@ -186,10 +192,10 @@ ip6_tnl_link(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
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{
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struct ip6_tnl **tp = ip6_tnl_bucket(ip6n, &t->parms);
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spin_lock_bh(&ip6_tnl_lock);
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t->next = *tp;
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write_lock_bh(&ip6_tnl_lock);
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*tp = t;
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write_unlock_bh(&ip6_tnl_lock);
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rcu_assign_pointer(*tp, t);
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spin_unlock_bh(&ip6_tnl_lock);
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}
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/**
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@ -204,9 +210,9 @@ ip6_tnl_unlink(struct ip6_tnl_net *ip6n, struct ip6_tnl *t)
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for (tp = ip6_tnl_bucket(ip6n, &t->parms); *tp; tp = &(*tp)->next) {
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if (t == *tp) {
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write_lock_bh(&ip6_tnl_lock);
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spin_lock_bh(&ip6_tnl_lock);
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*tp = t->next;
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write_unlock_bh(&ip6_tnl_lock);
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spin_unlock_bh(&ip6_tnl_lock);
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break;
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}
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}
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@ -313,9 +319,9 @@ ip6_tnl_dev_uninit(struct net_device *dev)
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struct ip6_tnl_net *ip6n = net_generic(net, ip6_tnl_net_id);
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if (dev == ip6n->fb_tnl_dev) {
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write_lock_bh(&ip6_tnl_lock);
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spin_lock_bh(&ip6_tnl_lock);
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ip6n->tnls_wc[0] = NULL;
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write_unlock_bh(&ip6_tnl_lock);
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spin_unlock_bh(&ip6_tnl_lock);
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} else {
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ip6_tnl_unlink(ip6n, t);
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}
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@ -409,7 +415,7 @@ ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
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in trouble since we might need the source address for further
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processing of the error. */
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read_lock(&ip6_tnl_lock);
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rcu_read_lock();
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if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->daddr,
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&ipv6h->saddr)) == NULL)
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goto out;
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@ -482,7 +488,7 @@ ip6_tnl_err(struct sk_buff *skb, __u8 ipproto, struct inet6_skb_parm *opt,
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*msg = rel_msg;
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out:
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read_unlock(&ip6_tnl_lock);
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rcu_read_unlock();
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return err;
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}
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@ -693,23 +699,23 @@ static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol,
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struct ip6_tnl *t;
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struct ipv6hdr *ipv6h = ipv6_hdr(skb);
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read_lock(&ip6_tnl_lock);
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rcu_read_lock();
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if ((t = ip6_tnl_lookup(dev_net(skb->dev), &ipv6h->saddr,
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&ipv6h->daddr)) != NULL) {
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if (t->parms.proto != ipproto && t->parms.proto != 0) {
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read_unlock(&ip6_tnl_lock);
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rcu_read_unlock();
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goto discard;
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}
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if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb)) {
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read_unlock(&ip6_tnl_lock);
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rcu_read_unlock();
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goto discard;
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}
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if (!ip6_tnl_rcv_ctl(t)) {
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t->dev->stats.rx_dropped++;
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read_unlock(&ip6_tnl_lock);
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rcu_read_unlock();
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goto discard;
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}
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secpath_reset(skb);
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@ -727,10 +733,10 @@ static int ip6_tnl_rcv(struct sk_buff *skb, __u16 protocol,
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t->dev->stats.rx_packets++;
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t->dev->stats.rx_bytes += skb->len;
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netif_rx(skb);
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read_unlock(&ip6_tnl_lock);
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rcu_read_unlock();
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return 0;
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}
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read_unlock(&ip6_tnl_lock);
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rcu_read_unlock();
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return 1;
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discard:
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