net/smc: replace sock_put worker by socket refcounting

Proper socket refcounting makes the sock_put worker obsolete.

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

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 90c22a854f28e73cbcefef30a3eb6537cb3bfa97..732a37ddbc21492dcb578c8322487e4625cd6ccb 100644 (file)
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -115,7 +115,6 @@ static int smc_release(struct socket *sock)
                goto out;
 
        smc = smc_sk(sk);
-       sock_hold(sk);
        if (sk->sk_state == SMC_LISTEN)
                /* smc_close_non_accepted() is called and acquires
                 * sock lock for child sockets again
@@ -124,10 +123,7 @@ static int smc_release(struct socket *sock)
        else
                lock_sock(sk);
 
-       if (smc->use_fallback) {
-               sk->sk_state = SMC_CLOSED;
-               sk->sk_state_change(sk);
-       } else {
+       if (!smc->use_fallback) {
                rc = smc_close_active(smc);
                sock_set_flag(sk, SOCK_DEAD);
                sk->sk_shutdown |= SHUTDOWN_MASK;
@@ -136,20 +132,21 @@ static int smc_release(struct socket *sock)
                sock_release(smc->clcsock);
                smc->clcsock = NULL;
        }
+       if (smc->use_fallback) {
+               sock_put(sk); /* passive closing */
+               sk->sk_state = SMC_CLOSED;
+               sk->sk_state_change(sk);
+       }
 
        /* detach socket */
        sock_orphan(sk);
        sock->sk = NULL;
-       if (smc->use_fallback) {
-               schedule_delayed_work(&smc->sock_put_work, TCP_TIMEWAIT_LEN);
-       } else if (sk->sk_state == SMC_CLOSED) {
+       if (!smc->use_fallback && sk->sk_state == SMC_CLOSED)
                smc_conn_free(&smc->conn);
-               schedule_delayed_work(&smc->sock_put_work,
-                                     SMC_CLOSE_SOCK_PUT_DELAY);
-       }
        release_sock(sk);
 
-       sock_put(sk);
+       sk->sk_prot->unhash(sk);
+       sock_put(sk); /* final sock_put */
 out:
        return rc;
 }
@@ -181,7 +178,6 @@ static struct sock *smc_sock_alloc(struct net *net, struct socket *sock)
        INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
        INIT_LIST_HEAD(&smc->accept_q);
        spin_lock_init(&smc->accept_q_lock);
-       INIT_DELAYED_WORK(&smc->sock_put_work, smc_close_sock_put_work);
        sk->sk_prot->hash(sk);
        sk_refcnt_debug_inc(sk);
 
@@ -399,6 +395,8 @@ static int smc_connect_rdma(struct smc_sock *smc)
        int rc = 0;
        u8 ibport;
 
+       sock_hold(&smc->sk); /* sock put in passive closing */
+
        if (!tcp_sk(smc->clcsock->sk)->syn_smc) {
                /* peer has not signalled SMC-capability */
                smc->use_fallback = true;
@@ -542,6 +540,8 @@ out_err_unlock:
        mutex_unlock(&smc_create_lgr_pending);
        smc_conn_free(&smc->conn);
 out_err:
+       if (smc->sk.sk_state == SMC_INIT)
+               sock_put(&smc->sk); /* passive closing */
        return rc;
 }
 
@@ -620,7 +620,7 @@ static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
                new_sk->sk_state = SMC_CLOSED;
                sock_set_flag(new_sk, SOCK_DEAD);
                new_sk->sk_prot->unhash(new_sk);
-               sock_put(new_sk);
+               sock_put(new_sk); /* final */
                *new_smc = NULL;
                goto out;
        }
@@ -637,7 +637,7 @@ static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
 {
        struct smc_sock *par = smc_sk(parent);
 
-       sock_hold(sk);
+       sock_hold(sk); /* sock_put in smc_accept_unlink () */
        spin_lock(&par->accept_q_lock);
        list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
        spin_unlock(&par->accept_q_lock);
@@ -653,7 +653,7 @@ static void smc_accept_unlink(struct sock *sk)
        list_del_init(&smc_sk(sk)->accept_q);
        spin_unlock(&par->accept_q_lock);
        sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
-       sock_put(sk);
+       sock_put(sk); /* sock_hold in smc_accept_enqueue */
 }
 
 /* remove a sock from the accept queue to bind it to a new socket created
@@ -671,7 +671,7 @@ struct sock *smc_accept_dequeue(struct sock *parent,
                smc_accept_unlink(new_sk);
                if (new_sk->sk_state == SMC_CLOSED) {
                        new_sk->sk_prot->unhash(new_sk);
-                       sock_put(new_sk);
+                       sock_put(new_sk); /* final */
                        continue;
                }
                if (new_sock)
@@ -686,14 +686,11 @@ void smc_close_non_accepted(struct sock *sk)
 {
        struct smc_sock *smc = smc_sk(sk);
 
-       sock_hold(sk);
        lock_sock(sk);
        if (!sk->sk_lingertime)
                /* wait for peer closing */
                sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
-       if (smc->use_fallback) {
-               sk->sk_state = SMC_CLOSED;
-       } else {
+       if (!smc->use_fallback) {
                smc_close_active(smc);
                sock_set_flag(sk, SOCK_DEAD);
                sk->sk_shutdown |= SHUTDOWN_MASK;
@@ -706,14 +703,15 @@ void smc_close_non_accepted(struct sock *sk)
                sock_release(tcp);
        }
        if (smc->use_fallback) {
-               schedule_delayed_work(&smc->sock_put_work, TCP_TIMEWAIT_LEN);
-       } else if (sk->sk_state == SMC_CLOSED) {
-               smc_conn_free(&smc->conn);
-               schedule_delayed_work(&smc->sock_put_work,
-                                     SMC_CLOSE_SOCK_PUT_DELAY);
+               sock_put(sk); /* passive closing */
+               sk->sk_state = SMC_CLOSED;
+       } else {
+               if (sk->sk_state == SMC_CLOSED)
+                       smc_conn_free(&smc->conn);
        }
        release_sock(sk);
-       sock_put(sk);
+       sk->sk_prot->unhash(sk);
+       sock_put(sk); /* final sock_put */
 }
 
 static int smc_serv_conf_first_link(struct smc_sock *smc)
@@ -937,6 +935,8 @@ out_err_unlock:
                smc_lgr_forget(new_smc->conn.lgr);
        mutex_unlock(&smc_create_lgr_pending);
 out_err:
+       if (newsmcsk->sk_state == SMC_INIT)
+               sock_put(&new_smc->sk); /* passive closing */
        newsmcsk->sk_state = SMC_CLOSED;
        smc_conn_free(&new_smc->conn);
        goto enqueue; /* queue new sock with sk_err set */
@@ -963,12 +963,15 @@ static void smc_tcp_listen_work(struct work_struct *work)
                sock_hold(lsk); /* sock_put in smc_listen_work */
                INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
                smc_copy_sock_settings_to_smc(new_smc);
-               schedule_work(&new_smc->smc_listen_work);
+               sock_hold(&new_smc->sk); /* sock_put in passive closing */
+               if (!schedule_work(&new_smc->smc_listen_work))
+                       sock_put(&new_smc->sk);
        }
 
 out:
        release_sock(lsk);
        lsk->sk_data_ready(lsk); /* no more listening, wake accept */
+       sock_put(&lsmc->sk); /* sock_hold in smc_listen */
 }
 
 static int smc_listen(struct socket *sock, int backlog)
@@ -1002,7 +1005,9 @@ static int smc_listen(struct socket *sock, int backlog)
        sk->sk_ack_backlog = 0;
        sk->sk_state = SMC_LISTEN;
        INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
-       schedule_work(&smc->tcp_listen_work);
+       sock_hold(sk); /* sock_hold in tcp_listen_worker */
+       if (!schedule_work(&smc->tcp_listen_work))
+               sock_put(sk);
 
 out:
        release_sock(sk);
@@ -1019,6 +1024,7 @@ static int smc_accept(struct socket *sock, struct socket *new_sock,
        int rc = 0;
 
        lsmc = smc_sk(sk);
+       sock_hold(sk); /* sock_put below */
        lock_sock(sk);
 
        if (lsmc->sk.sk_state != SMC_LISTEN) {
@@ -1053,6 +1059,7 @@ static int smc_accept(struct socket *sock, struct socket *new_sock,
 
 out:
        release_sock(sk);
+       sock_put(sk); /* sock_hold above */
        return rc;
 }
 

diff --git a/net/smc/smc.h b/net/smc/smc.h
index 0bee9d16cf29c8817b8afb898053aaa354f51702..bfbe20234105563cfc16a7f5d748a02e3c846428 100644 (file)
--- a/net/smc/smc.h
+++ b/net/smc/smc.h
@@ -178,7 +178,6 @@ struct smc_sock {                           /* smc sock container */
        struct work_struct      smc_listen_work;/* prepare new accept socket */
        struct list_head        accept_q;       /* sockets to be accepted */
        spinlock_t              accept_q_lock;  /* protects accept_q */
-       struct delayed_work     sock_put_work;  /* final socket freeing */
        bool                    use_fallback;   /* fallback to tcp */
        u8                      wait_close_tx_prepared : 1;
                                                /* shutdown wr or close

diff --git a/net/smc/smc_cdc.c b/net/smc/smc_cdc.c
index 6e8f5fbe0f0915c97501bbd3e92310f2c2e9c09a..3cd086e5bd28c10eff887d94b51358757db094be 100644 (file)
--- a/net/smc/smc_cdc.c
+++ b/net/smc/smc_cdc.c
@@ -212,6 +212,14 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc,
                smc->sk.sk_data_ready(&smc->sk);
        }
 
+       /* piggy backed tx info */
+       /* trigger sndbuf consumer: RDMA write into peer RMBE and CDC */
+       if (diff_cons && smc_tx_prepared_sends(conn)) {
+               smc_tx_sndbuf_nonempty(conn);
+               /* trigger socket release if connection closed */
+               smc_close_wake_tx_prepared(smc);
+       }
+
        if (conn->local_rx_ctrl.conn_state_flags.peer_conn_abort) {
                smc->sk.sk_err = ECONNRESET;
                conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
@@ -221,15 +229,9 @@ static void smc_cdc_msg_recv_action(struct smc_sock *smc,
                if (smc->clcsock && smc->clcsock->sk)
                        smc->clcsock->sk->sk_shutdown |= RCV_SHUTDOWN;
                sock_set_flag(&smc->sk, SOCK_DONE);
-               schedule_work(&conn->close_work);
-       }
-
-       /* piggy backed tx info */
-       /* trigger sndbuf consumer: RDMA write into peer RMBE and CDC */
-       if (diff_cons && smc_tx_prepared_sends(conn)) {
-               smc_tx_sndbuf_nonempty(conn);
-               /* trigger socket release if connection closed */
-               smc_close_wake_tx_prepared(smc);
+               sock_hold(&smc->sk); /* sock_put in close_work */
+               if (!schedule_work(&conn->close_work))
+                       sock_put(&smc->sk);
        }
 }
 

diff --git a/net/smc/smc_close.c b/net/smc/smc_close.c
index babe05d385e71f02181f72683f4e0897448975a1..4339852a8910bb241464969ab2aa0ab8ab047b2c 100644 (file)
--- a/net/smc/smc_close.c
+++ b/net/smc/smc_close.c
@@ -110,6 +110,7 @@ static void smc_close_active_abort(struct smc_sock *smc)
                release_sock(sk);
                cancel_delayed_work_sync(&smc->conn.tx_work);
                lock_sock(sk);
+               sock_put(sk); /* passive closing */
                break;
        case SMC_APPCLOSEWAIT1:
        case SMC_APPCLOSEWAIT2:
@@ -125,11 +126,13 @@ static void smc_close_active_abort(struct smc_sock *smc)
        case SMC_PEERCLOSEWAIT1:
        case SMC_PEERCLOSEWAIT2:
                if (!txflags->peer_conn_closed) {
+                       /* just SHUTDOWN_SEND done */
                        sk->sk_state = SMC_PEERABORTWAIT;
                        sock_release(smc->clcsock);
                } else {
                        sk->sk_state = SMC_CLOSED;
                }
+               sock_put(sk); /* passive closing */
                break;
        case SMC_PROCESSABORT:
        case SMC_APPFINCLOSEWAIT:
@@ -138,6 +141,8 @@ static void smc_close_active_abort(struct smc_sock *smc)
                sk->sk_state = SMC_CLOSED;
                break;
        case SMC_PEERFINCLOSEWAIT:
+               sock_put(sk); /* passive closing */
+               break;
        case SMC_PEERABORTWAIT:
        case SMC_CLOSED:
                break;
@@ -229,12 +234,14 @@ again:
                rc = smc_close_final(conn);
                if (rc)
                        break;
-               if (smc_cdc_rxed_any_close(conn))
+               if (smc_cdc_rxed_any_close(conn)) {
                        /* peer has closed the socket already */
                        sk->sk_state = SMC_CLOSED;
-               else
+                       sock_put(sk); /* postponed passive closing */
+               } else {
                        /* peer has just issued a shutdown write */
                        sk->sk_state = SMC_PEERFINCLOSEWAIT;
+               }
                break;
        case SMC_PEERCLOSEWAIT1:
        case SMC_PEERCLOSEWAIT2:
@@ -272,27 +279,33 @@ static void smc_close_passive_abort_received(struct smc_sock *smc)
        struct sock *sk = &smc->sk;
 
        switch (sk->sk_state) {
+       case SMC_INIT:
        case SMC_ACTIVE:
-       case SMC_APPFINCLOSEWAIT:
        case SMC_APPCLOSEWAIT1:
-       case SMC_APPCLOSEWAIT2:
+               sk->sk_state = SMC_PROCESSABORT;
+               sock_put(sk); /* passive closing */
+               break;
+       case SMC_APPFINCLOSEWAIT:
                sk->sk_state = SMC_PROCESSABORT;
                break;
        case SMC_PEERCLOSEWAIT1:
        case SMC_PEERCLOSEWAIT2:
                if (txflags->peer_done_writing &&
-                   !smc_close_sent_any_close(&smc->conn)) {
+                   !smc_close_sent_any_close(&smc->conn))
                        /* just shutdown, but not yet closed locally */
                        sk->sk_state = SMC_PROCESSABORT;
-               } else {
+               else
                        sk->sk_state = SMC_CLOSED;
-               }
+               sock_put(sk); /* passive closing */
                break;
+       case SMC_APPCLOSEWAIT2:
        case SMC_PEERFINCLOSEWAIT:
+               sk->sk_state = SMC_CLOSED;
+               sock_put(sk); /* passive closing */
+               break;
        case SMC_PEERABORTWAIT:
                sk->sk_state = SMC_CLOSED;
                break;
-       case SMC_INIT:
        case SMC_PROCESSABORT:
        /* nothing to do, add tracing in future patch */
                break;
@@ -336,13 +349,18 @@ static void smc_close_passive_work(struct work_struct *work)
        case SMC_INIT:
                if (atomic_read(&conn->bytes_to_rcv) ||
                    (rxflags->peer_done_writing &&
-                    !smc_cdc_rxed_any_close(conn)))
+                    !smc_cdc_rxed_any_close(conn))) {
                        sk->sk_state = SMC_APPCLOSEWAIT1;
-               else
+               } else {
                        sk->sk_state = SMC_CLOSED;
+                       sock_put(sk); /* passive closing */
+               }
                break;
        case SMC_ACTIVE:
                sk->sk_state = SMC_APPCLOSEWAIT1;
+               /* postpone sock_put() for passive closing to cover
+                * received SEND_SHUTDOWN as well
+                */
                break;
        case SMC_PEERCLOSEWAIT1:
                if (rxflags->peer_done_writing)
@@ -360,13 +378,20 @@ static void smc_close_passive_work(struct work_struct *work)
                        /* just shutdown, but not yet closed locally */
                        sk->sk_state = SMC_APPFINCLOSEWAIT;
                }
+               sock_put(sk); /* passive closing */
                break;
        case SMC_PEERFINCLOSEWAIT:
-               if (smc_cdc_rxed_any_close(conn))
+               if (smc_cdc_rxed_any_close(conn)) {
                        sk->sk_state = SMC_CLOSED;
+                       sock_put(sk); /* passive closing */
+               }
                break;
        case SMC_APPCLOSEWAIT1:
        case SMC_APPCLOSEWAIT2:
+               /* postpone sock_put() for passive closing to cover
+                * received SEND_SHUTDOWN as well
+                */
+               break;
        case SMC_APPFINCLOSEWAIT:
        case SMC_PEERABORTWAIT:
        case SMC_PROCESSABORT:
@@ -382,23 +407,11 @@ wakeup:
        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)) {
+                   (sock_flag(sk, SOCK_DEAD) || !sk->sk_socket))
                        smc_conn_free(conn);
-                       schedule_delayed_work(&smc->sock_put_work,
-                                             SMC_CLOSE_SOCK_PUT_DELAY);
-               }
        }
        release_sock(sk);
-}
-
-void smc_close_sock_put_work(struct work_struct *work)
-{
-       struct smc_sock *smc = container_of(to_delayed_work(work),
-                                           struct smc_sock,
-                                           sock_put_work);
-
-       smc->sk.sk_prot->unhash(&smc->sk);
-       sock_put(&smc->sk);
+       sock_put(sk); /* sock_hold done by schedulers of close_work */
 }
 
 int smc_close_shutdown_write(struct smc_sock *smc)

diff --git a/net/smc/smc_close.h b/net/smc/smc_close.h
index 8c498885d758f0ffc62b85a59b884bcafb12040a..19eb6a211c23cd12fad8f5077a26209bb05c3d33 100644 (file)
--- a/net/smc/smc_close.h
+++ b/net/smc/smc_close.h
@@ -21,7 +21,6 @@
 
 void smc_close_wake_tx_prepared(struct smc_sock *smc);
 int smc_close_active(struct smc_sock *smc);
-void smc_close_sock_put_work(struct work_struct *work);
 int smc_close_shutdown_write(struct smc_sock *smc);
 void smc_close_init(struct smc_sock *smc);
 

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index ed5b46d1fe41ad6df073f7a55f6e26abd05f3aa0..2424c7100aaf63cf19e9d63aaa110f25c6aefe3a 100644 (file)
--- a/net/smc/smc_core.c
+++ b/net/smc/smc_core.c
@@ -328,13 +328,13 @@ void smc_lgr_terminate(struct smc_link_group *lgr)
        while (node) {
                conn = rb_entry(node, struct smc_connection, alert_node);
                smc = container_of(conn, struct smc_sock, conn);
-               sock_hold(&smc->sk);
+               sock_hold(&smc->sk); /* sock_put in close work */
                conn->local_tx_ctrl.conn_state_flags.peer_conn_abort = 1;
                __smc_lgr_unregister_conn(conn);
                write_unlock_bh(&lgr->conns_lock);
-               schedule_work(&conn->close_work);
+               if (!schedule_work(&conn->close_work))
+                       sock_put(&smc->sk);
                write_lock_bh(&lgr->conns_lock);
-               sock_put(&smc->sk);
                node = rb_first(&lgr->conns_all);
        }
        write_unlock_bh(&lgr->conns_lock);