tcp: use limited socket backlog

[ Upstream commit 6b03a53a5ab7ccf2d5d69f96cf1c739c4d2a8fb9 ]

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 8 insertions, 4 deletions

diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 65b8ebfd078a..febfe1586e19 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -1677,8 +1677,10 @@ 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);
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index febfd595a40d..d89f405528c2 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1732,8 +1732,10 @@ process:
                         if (!tcp_prequeue(sk, skb))
                                 ret = tcp_v6_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);