int sysctl_tcp_nometrics_save __read_mostly;
+static struct tcp_metrics_block *__tcp_get_metrics(const struct inetpeer_addr *addr,
+ struct net *net, unsigned int hash);
+
struct tcp_fastopen_metrics {
u16 mss;
u16 syn_loss:10; /* Recurring Fast Open SYN losses */
}
}
+#define TCP_METRICS_TIMEOUT (60 * 60 * HZ)
+
+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);
+}
+
+#define TCP_METRICS_RECLAIM_DEPTH 5
+#define TCP_METRICS_RECLAIM_PTR (struct tcp_metrics_block *) 0x1UL
+
static struct tcp_metrics_block *tcpm_new(struct dst_entry *dst,
struct inetpeer_addr *addr,
- unsigned int hash,
- bool reclaim)
+ 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(addr, 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;
return tm;
}
-#define TCP_METRICS_TIMEOUT (60 * 60 * HZ)
-
-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);
-}
-
-#define TCP_METRICS_RECLAIM_DEPTH 5
-#define TCP_METRICS_RECLAIM_PTR (struct tcp_metrics_block *) 0x1UL
-
static struct tcp_metrics_block *tcp_get_encode(struct tcp_metrics_block *tm, int depth)
{
if (tm)
struct inetpeer_addr addr;
unsigned int hash;
struct net *net;
- bool reclaim;
addr.family = sk->sk_family;
switch (addr.family) {
hash = hash_32(hash, net->ipv4.tcp_metrics_hash_log);
tm = __tcp_get_metrics(&addr, net, hash);
- reclaim = false;
- if (tm == TCP_METRICS_RECLAIM_PTR) {
- reclaim = true;
+ if (tm == TCP_METRICS_RECLAIM_PTR)
tm = NULL;
- }
if (!tm && create)
- tm = tcpm_new(dst, &addr, hash, reclaim);
+ tm = tcpm_new(dst, &addr, hash);
else
tcpm_check_stamp(tm, dst);
void tcp_fastopen_cache_set(struct sock *sk, u16 mss,
struct tcp_fastopen_cookie *cookie, bool syn_lost)
{
+ struct dst_entry *dst = __sk_dst_get(sk);
struct tcp_metrics_block *tm;
+ if (!dst)
+ return;
rcu_read_lock();
- tm = tcp_get_metrics(sk, __sk_dst_get(sk), true);
+ tm = tcp_get_metrics(sk, dst, true);
if (tm) {
struct tcp_fastopen_metrics *tfom = &tm->tcpm_fastopen;