diff options
| author | David S. Miller | 2021-07-23 15:59:46 +0100 |
|---|---|---|
| committer | David S. Miller | 2021-07-23 16:13:06 +0100 |
| commit | 5af84df962dd6699e3972fda7a0c8b579fb3ab04 (patch) | |
| tree | 0a66f54c99c0c0d22588304d030ecb752487dfa1 /net/ipv4/tcp_fastopen.c | |
| parent | 090597b4a9c1b81b03fd7cfb4ba458a0e7a78b31 (diff) | |
| parent | 9f42f674a89200d4f465a7db6070e079f3c6145f (diff) | |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Conflicts are simple overlapping changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/tcp_fastopen.c')
| -rw-r--r-- | net/ipv4/tcp_fastopen.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c index 1a9fbd5448a7..62ba8d0f2c60 100644 --- a/net/ipv4/tcp_fastopen.c +++ b/net/ipv4/tcp_fastopen.c @@ -496,8 +496,18 @@ void tcp_fastopen_active_disable(struct sock *sk) { struct net *net = sock_net(sk); + if (!sock_net(sk)->ipv4.sysctl_tcp_fastopen_blackhole_timeout) + return; + + /* Paired with READ_ONCE() in tcp_fastopen_active_should_disable() */ + WRITE_ONCE(net->ipv4.tfo_active_disable_stamp, jiffies); + + /* Paired with smp_rmb() in tcp_fastopen_active_should_disable(). + * We want net->ipv4.tfo_active_disable_stamp to be updated first. + */ + smp_mb__before_atomic(); atomic_inc(&net->ipv4.tfo_active_disable_times); - net->ipv4.tfo_active_disable_stamp = jiffies; + NET_INC_STATS(net, LINUX_MIB_TCPFASTOPENBLACKHOLE); } @@ -508,17 +518,27 @@ void tcp_fastopen_active_disable(struct sock *sk) bool tcp_fastopen_active_should_disable(struct sock *sk) { unsigned int tfo_bh_timeout = sock_net(sk)->ipv4.sysctl_tcp_fastopen_blackhole_timeout; - int tfo_da_times = atomic_read(&sock_net(sk)->ipv4.tfo_active_disable_times); unsigned long timeout; + int tfo_da_times; int multiplier; + if (!tfo_bh_timeout) + return false; + + tfo_da_times = atomic_read(&sock_net(sk)->ipv4.tfo_active_disable_times); if (!tfo_da_times) return false; + /* Paired with smp_mb__before_atomic() in tcp_fastopen_active_disable() */ + smp_rmb(); + /* Limit timeout to max: 2^6 * initial timeout */ multiplier = 1 << min(tfo_da_times - 1, 6); - timeout = multiplier * tfo_bh_timeout * HZ; - if (time_before(jiffies, sock_net(sk)->ipv4.tfo_active_disable_stamp + timeout)) + + /* Paired with the WRITE_ONCE() in tcp_fastopen_active_disable(). */ + timeout = READ_ONCE(sock_net(sk)->ipv4.tfo_active_disable_stamp) + + multiplier * tfo_bh_timeout * HZ; + if (time_before(jiffies, timeout)) return true; /* Mark check bit so we can check for successful active TFO |