Merge tag 'spi-v4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

[firefly-linux-kernel-4.4.55.git] / net / ipv4 / tcp_fastopen.c

diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
index f69f436fcbccf701ae0785b77ba18fbeaa5dee02..55be6ac70cff3679cd7a80aa9aaac48ac156a203 100644 (file)
--- a/net/ipv4/tcp_fastopen.c
+++ b/net/ipv4/tcp_fastopen.c
@@ -133,12 +133,14 @@ static struct sock *tcp_fastopen_create_child(struct sock *sk,
        struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue;
        struct sock *child;
        u32 end_seq;
+       bool own_req;
 
        req->num_retrans = 0;
        req->num_timeout = 0;
        req->sk = NULL;
 
-       child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL);
+       child = inet_csk(sk)->icsk_af_ops->syn_recv_sock(sk, skb, req, NULL,
+                                                        NULL, &own_req);
        if (!child)
                return NULL;
 
@@ -161,15 +163,13 @@ static struct sock *tcp_fastopen_create_child(struct sock *sk,
        tp->snd_wnd = ntohs(tcp_hdr(skb)->window);
 
        /* Activate the retrans timer so that SYNACK can be retransmitted.
-        * The request socket is not added to the SYN table of the parent
+        * The request socket is not added to the ehash
         * because it's been added to the accept queue directly.
         */
        inet_csk_reset_xmit_timer(child, ICSK_TIME_RETRANS,
                                  TCP_TIMEOUT_INIT, TCP_RTO_MAX);
 
-       atomic_set(&req->rsk_refcnt, 1);
-       /* Add the child socket directly into the accept queue */
-       inet_csk_reqsk_queue_add(sk, req, child);
+       atomic_set(&req->rsk_refcnt, 2);
 
        /* Now finish processing the fastopen child socket. */
        inet_csk(child)->icsk_af_ops->rebuild_header(child);
@@ -178,12 +178,10 @@ static struct sock *tcp_fastopen_create_child(struct sock *sk,
        tcp_init_metrics(child);
        tcp_init_buffer_space(child);
 
-       /* Queue the data carried in the SYN packet. We need to first
-        * bump skb's refcnt because the caller will attempt to free it.
-        * Note that IPv6 might also have used skb_get() trick
-        * in tcp_v6_conn_request() to keep this SYN around (treq->pktopts)
-        * So we need to eventually get a clone of the packet,
-        * before inserting it in sk_receive_queue.
+       /* Queue the data carried in the SYN packet.
+        * We used to play tricky games with skb_get().
+        * With lockless listener, it is a dead end.
+        * Do not think about it.
         *
         * XXX (TFO) - we honor a zero-payload TFO request for now,
         * (any reason not to?) but no need to queue the skb since
@@ -191,12 +189,7 @@ static struct sock *tcp_fastopen_create_child(struct sock *sk,
         */
        end_seq = TCP_SKB_CB(skb)->end_seq;
        if (end_seq != TCP_SKB_CB(skb)->seq + 1) {
-               struct sk_buff *skb2;
-
-               if (unlikely(skb_shared(skb)))
-                       skb2 = skb_clone(skb, GFP_ATOMIC);
-               else
-                       skb2 = skb_get(skb);
+               struct sk_buff *skb2 = skb_clone(skb, GFP_ATOMIC);
 
                if (likely(skb2)) {
                        skb_dst_drop(skb2);
@@ -214,12 +207,9 @@ static struct sock *tcp_fastopen_create_child(struct sock *sk,
                }
        }
        tcp_rsk(req)->rcv_nxt = tp->rcv_nxt = end_seq;
-       sk->sk_data_ready(sk);
-       bh_unlock_sock(child);
-       /* Note: sock_put(child) will be done by tcp_conn_request()
-        * after SYNACK packet is sent.
+       /* tcp_conn_request() is sending the SYNACK,
+        * and queues the child into listener accept queue.
         */
-       WARN_ON(!req->sk);
        return child;
 }