net/smc: guarantee ConnClosed send after shutdown SHUT_WR

State SMC_CLOSED should be reached only, if ConnClosed has been sent to
the peer. If ConnClosed is received from the peer, a socket with
shutdown SHUT_WR done, switches errorneously to state SMC_CLOSED, which
means the peer socket is dangling. The local SMC socket is supposed to
switch to state APPFINCLOSEWAIT to make sure smc_close_final() is called
during socket close.

Signed-off-by: Ursula Braun <ubraun@linux.vnet.ibm.com>
Reviewed-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/smc/smc_close.c b/net/smc/smc_close.c
index 388503b..9070720 100644 (file)
--- a/net/smc/smc_close.c
+++ b/net/smc/smc_close.c
@@ -164,6 +164,12 @@ void smc_close_active_abort(struct smc_sock *smc)
        smc->sk.sk_state_change(&smc->sk);
 }
 
+static inline bool smc_close_sent_any_close(struct smc_connection *conn)
+{
+       return conn->local_tx_ctrl.conn_state_flags.peer_conn_abort ||
+              conn->local_tx_ctrl.conn_state_flags.peer_conn_closed;
+}
+
 int smc_close_active(struct smc_sock *smc)
 {
        struct smc_cdc_conn_state_flags *txflags =
@@ -217,7 +223,7 @@ again:
        case SMC_APPFINCLOSEWAIT:
                /* socket already shutdown wr or both (active close) */
                if (txflags->peer_done_writing &&
-                   !txflags->peer_conn_closed) {
+                   !smc_close_sent_any_close(conn)) {
                        /* just shutdown wr done, send close request */
                        rc = smc_close_final(conn);
                }
@@ -247,6 +253,13 @@ again:
                break;
        case SMC_PEERCLOSEWAIT1:
        case SMC_PEERCLOSEWAIT2:
+               if (txflags->peer_done_writing &&
+                   !smc_close_sent_any_close(conn)) {
+                       /* just shutdown wr done, send close request */
+                       rc = smc_close_final(conn);
+               }
+               /* peer sending PeerConnectionClosed will cause transition */
+               break;
        case SMC_PEERFINCLOSEWAIT:
                /* peer sending PeerConnectionClosed will cause transition */
                break;
@@ -284,7 +297,7 @@ static void smc_close_passive_abort_received(struct smc_sock *smc)
        case SMC_PEERCLOSEWAIT1:
        case SMC_PEERCLOSEWAIT2:
                if (txflags->peer_done_writing &&
-                   !txflags->peer_conn_closed) {
+                   !smc_close_sent_any_close(&smc->conn)) {
                        /* just shutdown, but not yet closed locally */
                        smc_close_abort(&smc->conn);
                        sk->sk_state = SMC_PROCESSABORT;
@@ -335,7 +348,7 @@ static void smc_close_passive_work(struct work_struct *work)
        case SMC_INIT:
                if (atomic_read(&smc->conn.bytes_to_rcv) ||
                    (rxflags->peer_done_writing &&
-                    !rxflags->peer_conn_closed))
+                    !smc_cdc_rxed_any_close(conn)))
                        sk->sk_state = SMC_APPCLOSEWAIT1;
                else
                        sk->sk_state = SMC_CLOSED;
@@ -352,7 +365,7 @@ static void smc_close_passive_work(struct work_struct *work)
                if (!smc_cdc_rxed_any_close(&smc->conn))
                        break;
                if (sock_flag(sk, SOCK_DEAD) &&
-                   (sk->sk_shutdown == SHUTDOWN_MASK)) {
+                   smc_close_sent_any_close(conn)) {
                        /* smc_release has already been called locally */
                        sk->sk_state = SMC_CLOSED;
                } else {
@@ -371,16 +384,17 @@ static void smc_close_passive_work(struct work_struct *work)
        }
 
 wakeup:
-       if (old_state != sk->sk_state)
-               sk->sk_state_change(sk);
        sk->sk_data_ready(sk); /* wakeup blocked rcvbuf consumers */
        sk->sk_write_space(sk); /* wakeup blocked sndbuf producers */
 
-       if ((sk->sk_state == SMC_CLOSED) &&
-           (sock_flag(sk, SOCK_DEAD) || !sk->sk_socket)) {
-               smc_conn_free(&smc->conn);
-               schedule_delayed_work(&smc->sock_put_work,
-                                     SMC_CLOSE_SOCK_PUT_DELAY);
+       if (old_state != sk->sk_state) {
+               sk->sk_state_change(sk);
+               if ((sk->sk_state == SMC_CLOSED) &&
+                   (sock_flag(sk, SOCK_DEAD) || !sk->sk_socket)) {
+                       smc_conn_free(&smc->conn);
+                       schedule_delayed_work(&smc->sock_put_work,
+                                             SMC_CLOSE_SOCK_PUT_DELAY);
+               }
        }
        release_sock(&smc->sk);
 }