static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst,
struct inetpeer_addr *saddr,
struct inetpeer_addr *daddr,
unsigned int hash)
{
struct tcp_metrics_block *tm;
struct net *net;
bool reclaim = false;
spin_lock_bh(&tcp_metrics_lock);
net = dev_net(dst->dev);
/* While waiting for the spin-lock the cache might have been populated
* with this entry and so we have to check again.
*/
tm = __tcp_get_metrics(saddr, daddr, net, hash);
if (tm == TCP_METRICS_RECLAIM_PTR) {
reclaim = true;
tm = NULL;
}
if (tm) {
tcpm_check_stamp(tm, dst);
goto out_unlock;
}
if (unlikely(reclaim)) {
struct tcp_metrics_block *oldest;
oldest = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain);
for (tm = rcu_dereference(oldest->tcpm_next); tm;
tm = rcu_dereference(tm->tcpm_next)) {
if (time_before(tm->tcpm_stamp, oldest->tcpm_stamp))
oldest = tm;
}
tm = oldest;
} else {
tm = kmalloc(sizeof(*tm), GFP_ATOMIC);
if (!tm)
goto out_unlock;
}
tm->tcpm_saddr = *saddr;
tm->tcpm_daddr = *daddr;
tcpm_suck_dst(tm, dst, true);
if (likely(!reclaim)) {
tm->tcpm_next = net->ipv4.tcp_metrics_hash[hash].chain;
rcu_assign_pointer(net->ipv4.tcp_metrics_hash[hash].chain, tm);
}
out_unlock:
spin_unlock_bh(&tcp_metrics_lock);
return tm;
}
static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst,
struct inetpeer_addr *addr,
unsigned int hash,
bool reclaim)
{
struct tcp_metrics_block *tm;
struct net *net;
spin_lock_bh(&tcp_metrics_lock);
net = dev_net(dst->dev);
if (unlikely(reclaim)) {
struct tcp_metrics_block *oldest;
oldest = rcu_dereference(net->ipv4.tcp_metrics_hash[hash].chain);
for (tm = rcu_dereference(oldest->tcpm_next); tm;
tm = rcu_dereference(tm->tcpm_next)) {
if (time_before(tm->tcpm_stamp, oldest->tcpm_stamp))
oldest = tm;
}
tm = oldest;
} else {
tm = kmalloc(sizeof(*tm), GFP_ATOMIC);
if (!tm)
goto out_unlock;
}
tm->tcpm_addr = *addr;
tcpm_suck_dst(tm, dst, true);
if (likely(!reclaim)) {
tm->tcpm_next = net->ipv4.tcp_metrics_hash[hash].chain;
rcu_assign_pointer(net->ipv4.tcp_metrics_hash[hash].chain, tm);
}
out_unlock:
spin_unlock_bh(&tcp_metrics_lock);
return tm;
}
static void tcpm_check_stamp(struct tcp_metrics_block *tm, struct dst_entry *dst)
{
if (tm && unlikely(time_after(jiffies, tm->tcpm_stamp + TCP_METRICS_TIMEOUT)))
tcpm_suck_dst(tm, dst, false);
}