From: Ursula Braun <ubr...@linux.vnet.ibm.com>

TCP sockopt setting of TCP_DEFER_ACCEPT should just be applied
to the SMC socket, but not to the internal CLC socket.

If set, the accept is delayed till data is available.

Signed-off-by: Ursula Braun <ubr...@linux.vnet.ibm.com>
---
 net/smc/af_smc.c | 36 +++++++++++++++++++++++++++++++++++-
 net/smc/smc.h    |  4 ++++
 net/smc/smc_rx.c |  2 +-
 net/smc/smc_rx.h |  1 +
 4 files changed, 41 insertions(+), 2 deletions(-)

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 27d3aa8d0181..c5ece2b28179 100644
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1098,9 +1098,29 @@ static int smc_accept(struct socket *sock, struct socket 
*new_sock,
 
        if (!rc)
                rc = sock_error(nsk);
+       release_sock(sk);
+       if (rc)
+               goto out;
+
+       if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
+               /* wait till data arrives on the socket */
+               timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
+                                                               MSEC_PER_SEC);
+               if (smc_sk(nsk)->use_fallback) {
+                       struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
+
+                       lock_sock(clcsk);
+                       if (skb_queue_empty(&clcsk->sk_receive_queue))
+                               sk_wait_data(clcsk, &timeo, NULL);
+                       release_sock(clcsk);
+               } else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
+                       lock_sock(nsk);
+                       smc_rx_wait_data(smc_sk(nsk), &timeo);
+                       release_sock(nsk);
+               }
+       }
 
 out:
-       release_sock(sk);
        sock_put(sk); /* sock_hold above */
        return rc;
 }
@@ -1367,6 +1387,14 @@ static int smc_setsockopt(struct socket *sock, int 
level, int optname,
                else
                        smc->deferred_cork_set = 0;
                break;
+       case TCP_DEFER_ACCEPT:
+               if (sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) {
+                       release_sock(sk);
+                       goto clcsock;
+               }
+               /* for the CLC-handshake TCP_DEFER_ACCEPT is not desired */
+               smc->sockopt_defer_accept = val;
+               break;
        case TCP_FASTOPEN:
        case TCP_FASTOPEN_CONNECT:
        case TCP_FASTOPEN_KEY:
@@ -1429,6 +1457,12 @@ static int smc_getsockopt(struct socket *sock, int 
level, int optname,
                else
                        goto clcsock;
                break;
+       case TCP_DEFER_ACCEPT:
+               if (smc->sockopt_defer_accept)
+                       val = smc->sockopt_defer_accept;
+               else
+                       goto clcsock;
+               break;
        default:
                goto clcsock;
        }
diff --git a/net/smc/smc.h b/net/smc/smc.h
index 38888da5a5ea..11f869d1f28a 100644
--- a/net/smc/smc.h
+++ b/net/smc/smc.h
@@ -180,6 +180,10 @@ struct smc_sock {                          /* smc sock 
container */
        struct list_head        accept_q;       /* sockets to be accepted */
        spinlock_t              accept_q_lock;  /* protects accept_q */
        bool                    use_fallback;   /* fallback to tcp */
+       int                     sockopt_defer_accept;
+                                               /* sockopt TCP_DEFER_ACCEPT
+                                                * value
+                                                */
        u8                      wait_close_tx_prepared : 1;
                                                /* shutdown wr or close
                                                 * started, waiting for unsent
diff --git a/net/smc/smc_rx.c b/net/smc/smc_rx.c
index eff4e0d0bb31..af851d8df1f8 100644
--- a/net/smc/smc_rx.c
+++ b/net/smc/smc_rx.c
@@ -51,7 +51,7 @@ static void smc_rx_data_ready(struct sock *sk)
  * 1 if at least 1 byte available in rcvbuf or if socket error/shutdown.
  * 0 otherwise (nothing in rcvbuf nor timeout, e.g. interrupted).
  */
-static int smc_rx_wait_data(struct smc_sock *smc, long *timeo)
+int smc_rx_wait_data(struct smc_sock *smc, long *timeo)
 {
        DEFINE_WAIT_FUNC(wait, woken_wake_function);
        struct smc_connection *conn = &smc->conn;
diff --git a/net/smc/smc_rx.h b/net/smc/smc_rx.h
index 3a32b59bf06c..0b75a6b470e6 100644
--- a/net/smc/smc_rx.h
+++ b/net/smc/smc_rx.h
@@ -20,5 +20,6 @@
 void smc_rx_init(struct smc_sock *smc);
 int smc_rx_recvmsg(struct smc_sock *smc, struct msghdr *msg, size_t len,
                   int flags);
+int smc_rx_wait_data(struct smc_sock *smc, long *timeo);
 
 #endif /* SMC_RX_H */
-- 
2.13.5

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