tcp: use limited socket backlog

Make tcp adapt to the limited socket backlog change.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Cc: "Pekka Savola (ipv6)" <pekkas@netcore.fi>
Cc: Patrick McHardy <kaber@trash.net>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 2 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index c3588b4fd979..4baf1943b1bd 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1682,8 +1682,10 @@ process:
                         if (!tcp_prequeue(sk, skb))
                                 ret = tcp_v4_do_rcv(sk, skb);
                 }
-        } else
-                sk_add_backlog(sk, skb);
+        } else if (sk_add_backlog_limited(sk, skb)) {
+                bh_unlock_sock(sk);
+                goto discard_and_relse;
+        }
         bh_unlock_sock(sk);
 
         sock_put(sk);