ipv4: fix a dst leak in tunnels

This patch :

1) Remove a dst leak if DST_NOCACHE was set on dst
   Fix this by holding a reference only if dst really cached.

2) Remove a lockdep warning in __tunnel_dst_set()
    This was reported by Cong Wang.

3) Remove usage of a spinlock where xchg() is enough

4) Remove some spurious inline keywords.
   Let compiler decide for us.

Fixes: 7d442fab0a ("ipv4: Cache dst in tunnels")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Cong Wang <cwang@twopensource.com>
Cc: Tom Herbert <therbert@google.com>
Cc: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2014-01-16 16:41:19 -08:00 committed by David S. Miller
parent db893473d3
commit 6c7e7610ff
2 changed files with 14 additions and 21 deletions

View File

@ -40,7 +40,6 @@ struct ip_tunnel_prl_entry {
struct ip_tunnel_dst {
struct dst_entry __rcu *dst;
spinlock_t lock;
};
struct ip_tunnel {

View File

@ -68,27 +68,27 @@ static unsigned int ip_tunnel_hash(struct ip_tunnel_net *itn,
IP_TNL_HASH_BITS);
}
static inline void __tunnel_dst_set(struct ip_tunnel_dst *idst,
struct dst_entry *dst)
static void __tunnel_dst_set(struct ip_tunnel_dst *idst,
struct dst_entry *dst)
{
struct dst_entry *old_dst;
if (dst && (dst->flags & DST_NOCACHE))
dst = NULL;
spin_lock_bh(&idst->lock);
old_dst = rcu_dereference(idst->dst);
rcu_assign_pointer(idst->dst, dst);
if (dst) {
if (dst->flags & DST_NOCACHE)
dst = NULL;
else
dst_clone(dst);
}
old_dst = xchg((__force struct dst_entry **)&idst->dst, dst);
dst_release(old_dst);
spin_unlock_bh(&idst->lock);
}
static inline void tunnel_dst_set(struct ip_tunnel *t, struct dst_entry *dst)
static void tunnel_dst_set(struct ip_tunnel *t, struct dst_entry *dst)
{
__tunnel_dst_set(this_cpu_ptr(t->dst_cache), dst);
}
static inline void tunnel_dst_reset(struct ip_tunnel *t)
static void tunnel_dst_reset(struct ip_tunnel *t)
{
tunnel_dst_set(t, NULL);
}
@ -101,7 +101,7 @@ static void tunnel_dst_reset_all(struct ip_tunnel *t)
__tunnel_dst_set(per_cpu_ptr(t->dst_cache, i), NULL);
}
static inline struct dst_entry *tunnel_dst_get(struct ip_tunnel *t)
static struct dst_entry *tunnel_dst_get(struct ip_tunnel *t)
{
struct dst_entry *dst;
@ -413,7 +413,7 @@ static int ip_tunnel_bind_dev(struct net_device *dev)
if (!IS_ERR(rt)) {
tdev = rt->dst.dev;
tunnel_dst_set(tunnel, dst_clone(&rt->dst));
tunnel_dst_set(tunnel, &rt->dst);
ip_rt_put(rt);
}
if (dev->type != ARPHRD_ETHER)
@ -668,7 +668,7 @@ void ip_tunnel_xmit(struct sk_buff *skb, struct net_device *dev,
goto tx_error;
}
if (connected)
tunnel_dst_set(tunnel, dst_clone(&rt->dst));
tunnel_dst_set(tunnel, &rt->dst);
}
if (rt->dst.dev == dev) {
@ -1066,12 +1066,6 @@ int ip_tunnel_init(struct net_device *dev)
return -ENOMEM;
}
for_each_possible_cpu(i) {
struct ip_tunnel_dst *idst = per_cpu_ptr(tunnel->dst_cache, i);
idst-> dst = NULL;
spin_lock_init(&idst->lock);
}
err = gro_cells_init(&tunnel->gro_cells, dev);
if (err) {
free_percpu(tunnel->dst_cache);