Merge branch 'devel' into for-linus
[sfrench/cifs-2.6.git] / net / sunrpc / xprtsock.c
index 568330eebbfeb68e469ead8f23f8f059093850b4..d40ff50887aa468544c500de540d7b6a29108b67 100644 (file)
@@ -49,6 +49,9 @@ unsigned int xprt_tcp_slot_table_entries = RPC_DEF_SLOT_TABLE;
 unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
 unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
 
+#define XS_TCP_LINGER_TO       (15U * HZ)
+static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
+
 /*
  * We can register our own files under /proc/sys/sunrpc by
  * calling register_sysctl_table() again.  The files in that
@@ -116,6 +119,14 @@ static ctl_table xs_tunables_table[] = {
                .extra1         = &xprt_min_resvport_limit,
                .extra2         = &xprt_max_resvport_limit
        },
+       {
+               .procname       = "tcp_fin_timeout",
+               .data           = &xs_tcp_fin_timeout,
+               .maxlen         = sizeof(xs_tcp_fin_timeout),
+               .mode           = 0644,
+               .proc_handler   = &proc_dointvec_jiffies,
+               .strategy       = sysctl_jiffies
+       },
        {
                .ctl_name = 0,
        },
@@ -521,11 +532,12 @@ static void xs_nospace_callback(struct rpc_task *task)
  * @task: task to put to sleep
  *
  */
-static void xs_nospace(struct rpc_task *task)
+static int xs_nospace(struct rpc_task *task)
 {
        struct rpc_rqst *req = task->tk_rqstp;
        struct rpc_xprt *xprt = req->rq_xprt;
        struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
+       int ret = 0;
 
        dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
                        task->tk_pid, req->rq_slen - req->rq_bytes_sent,
@@ -537,6 +549,7 @@ static void xs_nospace(struct rpc_task *task)
        /* Don't race with disconnect */
        if (xprt_connected(xprt)) {
                if (test_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags)) {
+                       ret = -EAGAIN;
                        /*
                         * Notify TCP that we're limited by the application
                         * window size
@@ -548,10 +561,11 @@ static void xs_nospace(struct rpc_task *task)
                }
        } else {
                clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
-               task->tk_status = -ENOTCONN;
+               ret = -ENOTCONN;
        }
 
        spin_unlock_bh(&xprt->transport_lock);
+       return ret;
 }
 
 /**
@@ -594,6 +608,8 @@ static int xs_udp_send_request(struct rpc_task *task)
                /* Still some bytes left; set up for a retry later. */
                status = -EAGAIN;
        }
+       if (!transport->sock)
+               goto out;
 
        switch (status) {
        case -ENOTSOCK:
@@ -601,21 +617,19 @@ static int xs_udp_send_request(struct rpc_task *task)
                /* Should we call xs_close() here? */
                break;
        case -EAGAIN:
-               xs_nospace(task);
+               status = xs_nospace(task);
                break;
+       default:
+               dprintk("RPC:       sendmsg returned unrecognized error %d\n",
+                       -status);
        case -ENETUNREACH:
        case -EPIPE:
        case -ECONNREFUSED:
                /* When the server has died, an ICMP port unreachable message
                 * prompts ECONNREFUSED. */
                clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
-               break;
-       default:
-               clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
-               dprintk("RPC:       sendmsg returned unrecognized error %d\n",
-                       -status);
        }
-
+out:
        return status;
 }
 
@@ -697,6 +711,8 @@ static int xs_tcp_send_request(struct rpc_task *task)
                status = -EAGAIN;
                break;
        }
+       if (!transport->sock)
+               goto out;
 
        switch (status) {
        case -ENOTSOCK:
@@ -704,23 +720,19 @@ static int xs_tcp_send_request(struct rpc_task *task)
                /* Should we call xs_close() here? */
                break;
        case -EAGAIN:
-               xs_nospace(task);
+               status = xs_nospace(task);
                break;
+       default:
+               dprintk("RPC:       sendmsg returned unrecognized error %d\n",
+                       -status);
        case -ECONNRESET:
+       case -EPIPE:
                xs_tcp_shutdown(xprt);
        case -ECONNREFUSED:
        case -ENOTCONN:
-       case -EPIPE:
-               status = -ENOTCONN;
-               clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
-               break;
-       default:
-               dprintk("RPC:       sendmsg returned unrecognized error %d\n",
-                       -status);
                clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
-               xs_tcp_shutdown(xprt);
        }
-
+out:
        return status;
 }
 
@@ -767,23 +779,13 @@ static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *s
        sk->sk_error_report = transport->old_error_report;
 }
 
-/**
- * xs_close - close a socket
- * @xprt: transport
- *
- * This is used when all requests are complete; ie, no DRC state remains
- * on the server we want to save.
- */
-static void xs_close(struct rpc_xprt *xprt)
+static void xs_reset_transport(struct sock_xprt *transport)
 {
-       struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
        struct socket *sock = transport->sock;
        struct sock *sk = transport->inet;
 
-       if (!sk)
-               goto clear_close_wait;
-
-       dprintk("RPC:       xs_close xprt %p\n", xprt);
+       if (sk == NULL)
+               return;
 
        write_lock_bh(&sk->sk_callback_lock);
        transport->inet = NULL;
@@ -797,8 +799,25 @@ static void xs_close(struct rpc_xprt *xprt)
        sk->sk_no_check = 0;
 
        sock_release(sock);
-clear_close_wait:
+}
+
+/**
+ * xs_close - close a socket
+ * @xprt: transport
+ *
+ * This is used when all requests are complete; ie, no DRC state remains
+ * on the server we want to save.
+ */
+static void xs_close(struct rpc_xprt *xprt)
+{
+       struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
+
+       dprintk("RPC:       xs_close xprt %p\n", xprt);
+
+       xs_reset_transport(transport);
+
        smp_mb__before_clear_bit();
+       clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
        clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
        clear_bit(XPRT_CLOSING, &xprt->state);
        smp_mb__after_clear_bit();
@@ -1126,6 +1145,47 @@ out:
        read_unlock(&sk->sk_callback_lock);
 }
 
+/*
+ * Do the equivalent of linger/linger2 handling for dealing with
+ * broken servers that don't close the socket in a timely
+ * fashion
+ */
+static void xs_tcp_schedule_linger_timeout(struct rpc_xprt *xprt,
+               unsigned long timeout)
+{
+       struct sock_xprt *transport;
+
+       if (xprt_test_and_set_connecting(xprt))
+               return;
+       set_bit(XPRT_CONNECTION_ABORT, &xprt->state);
+       transport = container_of(xprt, struct sock_xprt, xprt);
+       queue_delayed_work(rpciod_workqueue, &transport->connect_worker,
+                          timeout);
+}
+
+static void xs_tcp_cancel_linger_timeout(struct rpc_xprt *xprt)
+{
+       struct sock_xprt *transport;
+
+       transport = container_of(xprt, struct sock_xprt, xprt);
+
+       if (!test_bit(XPRT_CONNECTION_ABORT, &xprt->state) ||
+           !cancel_delayed_work(&transport->connect_worker))
+               return;
+       clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
+       xprt_clear_connecting(xprt);
+}
+
+static void xs_sock_mark_closed(struct rpc_xprt *xprt)
+{
+       smp_mb__before_clear_bit();
+       clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
+       clear_bit(XPRT_CLOSING, &xprt->state);
+       smp_mb__after_clear_bit();
+       /* Mark transport as closed and wake up all pending tasks */
+       xprt_disconnect_done(xprt);
+}
+
 /**
  * xs_tcp_state_change - callback to handle TCP socket state changes
  * @sk: socket whose state has changed
@@ -1158,7 +1218,7 @@ static void xs_tcp_state_change(struct sock *sk)
                        transport->tcp_flags =
                                TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
 
-                       xprt_wake_pending_tasks(xprt, 0);
+                       xprt_wake_pending_tasks(xprt, -EAGAIN);
                }
                spin_unlock_bh(&xprt->transport_lock);
                break;
@@ -1171,10 +1231,10 @@ static void xs_tcp_state_change(struct sock *sk)
                clear_bit(XPRT_CONNECTED, &xprt->state);
                clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
                smp_mb__after_clear_bit();
+               xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
                break;
        case TCP_CLOSE_WAIT:
                /* The server initiated a shutdown of the socket */
-               set_bit(XPRT_CLOSING, &xprt->state);
                xprt_force_disconnect(xprt);
        case TCP_SYN_SENT:
                xprt->connect_cookie++;
@@ -1187,40 +1247,35 @@ static void xs_tcp_state_change(struct sock *sk)
                        xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
                break;
        case TCP_LAST_ACK:
+               set_bit(XPRT_CLOSING, &xprt->state);
+               xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
                smp_mb__before_clear_bit();
                clear_bit(XPRT_CONNECTED, &xprt->state);
                smp_mb__after_clear_bit();
                break;
        case TCP_CLOSE:
-               smp_mb__before_clear_bit();
-               clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
-               clear_bit(XPRT_CLOSING, &xprt->state);
-               smp_mb__after_clear_bit();
-               /* Mark transport as closed and wake up all pending tasks */
-               xprt_disconnect_done(xprt);
+               xs_tcp_cancel_linger_timeout(xprt);
+               xs_sock_mark_closed(xprt);
        }
  out:
        read_unlock(&sk->sk_callback_lock);
 }
 
 /**
- * xs_tcp_error_report - callback mainly for catching RST events
+ * xs_error_report - callback mainly for catching socket errors
  * @sk: socket
  */
-static void xs_tcp_error_report(struct sock *sk)
+static void xs_error_report(struct sock *sk)
 {
        struct rpc_xprt *xprt;
 
        read_lock(&sk->sk_callback_lock);
-       if (sk->sk_err != ECONNRESET || sk->sk_state != TCP_ESTABLISHED)
-               goto out;
        if (!(xprt = xprt_from_sock(sk)))
                goto out;
        dprintk("RPC:       %s client %p...\n"
                        "RPC:       error %d\n",
                        __func__, xprt, sk->sk_err);
-
-       xprt_force_disconnect(xprt);
+       xprt_wake_pending_tasks(xprt, -EAGAIN);
 out:
        read_unlock(&sk->sk_callback_lock);
 }
@@ -1494,6 +1549,7 @@ static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
                sk->sk_user_data = xprt;
                sk->sk_data_ready = xs_udp_data_ready;
                sk->sk_write_space = xs_udp_write_space;
+               sk->sk_error_report = xs_error_report;
                sk->sk_no_check = UDP_CSUM_NORCV;
                sk->sk_allocation = GFP_ATOMIC;
 
@@ -1526,9 +1582,10 @@ static void xs_udp_connect_worker4(struct work_struct *work)
                goto out;
 
        /* Start by resetting any existing state */
-       xs_close(xprt);
+       xs_reset_transport(transport);
 
-       if ((err = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) {
+       err = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock);
+       if (err < 0) {
                dprintk("RPC:       can't create UDP transport socket (%d).\n", -err);
                goto out;
        }
@@ -1545,8 +1602,8 @@ static void xs_udp_connect_worker4(struct work_struct *work)
        xs_udp_finish_connecting(xprt, sock);
        status = 0;
 out:
-       xprt_wake_pending_tasks(xprt, status);
        xprt_clear_connecting(xprt);
+       xprt_wake_pending_tasks(xprt, status);
 }
 
 /**
@@ -1567,9 +1624,10 @@ static void xs_udp_connect_worker6(struct work_struct *work)
                goto out;
 
        /* Start by resetting any existing state */
-       xs_close(xprt);
+       xs_reset_transport(transport);
 
-       if ((err = sock_create_kern(PF_INET6, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) {
+       err = sock_create_kern(PF_INET6, SOCK_DGRAM, IPPROTO_UDP, &sock);
+       if (err < 0) {
                dprintk("RPC:       can't create UDP transport socket (%d).\n", -err);
                goto out;
        }
@@ -1586,18 +1644,17 @@ static void xs_udp_connect_worker6(struct work_struct *work)
        xs_udp_finish_connecting(xprt, sock);
        status = 0;
 out:
-       xprt_wake_pending_tasks(xprt, status);
        xprt_clear_connecting(xprt);
+       xprt_wake_pending_tasks(xprt, status);
 }
 
 /*
  * We need to preserve the port number so the reply cache on the server can
  * find our cached RPC replies when we get around to reconnecting.
  */
-static void xs_tcp_reuse_connection(struct rpc_xprt *xprt)
+static void xs_abort_connection(struct rpc_xprt *xprt, struct sock_xprt *transport)
 {
        int result;
-       struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
        struct sockaddr any;
 
        dprintk("RPC:       disconnecting xprt %p to reuse port\n", xprt);
@@ -1609,11 +1666,24 @@ static void xs_tcp_reuse_connection(struct rpc_xprt *xprt)
        memset(&any, 0, sizeof(any));
        any.sa_family = AF_UNSPEC;
        result = kernel_connect(transport->sock, &any, sizeof(any), 0);
-       if (result)
+       if (!result)
+               xs_sock_mark_closed(xprt);
+       else
                dprintk("RPC:       AF_UNSPEC connect return code %d\n",
                                result);
 }
 
+static void xs_tcp_reuse_connection(struct rpc_xprt *xprt, struct sock_xprt *transport)
+{
+       unsigned int state = transport->inet->sk_state;
+
+       if (state == TCP_CLOSE && transport->sock->state == SS_UNCONNECTED)
+               return;
+       if ((1 << state) & (TCPF_ESTABLISHED|TCPF_SYN_SENT))
+               return;
+       xs_abort_connection(xprt, transport);
+}
+
 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
 {
        struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
@@ -1629,7 +1699,7 @@ static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
                sk->sk_data_ready = xs_tcp_data_ready;
                sk->sk_state_change = xs_tcp_state_change;
                sk->sk_write_space = xs_tcp_write_space;
-               sk->sk_error_report = xs_tcp_error_report;
+               sk->sk_error_report = xs_error_report;
                sk->sk_allocation = GFP_ATOMIC;
 
                /* socket options */
@@ -1657,37 +1727,42 @@ static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
 }
 
 /**
- * xs_tcp_connect_worker4 - connect a TCP socket to a remote endpoint
- * @work: RPC transport to connect
+ * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
+ * @xprt: RPC transport to connect
+ * @transport: socket transport to connect
+ * @create_sock: function to create a socket of the correct type
  *
  * Invoked by a work queue tasklet.
  */
-static void xs_tcp_connect_worker4(struct work_struct *work)
+static void xs_tcp_setup_socket(struct rpc_xprt *xprt,
+               struct sock_xprt *transport,
+               struct socket *(*create_sock)(struct rpc_xprt *,
+                       struct sock_xprt *))
 {
-       struct sock_xprt *transport =
-               container_of(work, struct sock_xprt, connect_worker.work);
-       struct rpc_xprt *xprt = &transport->xprt;
        struct socket *sock = transport->sock;
-       int err, status = -EIO;
+       int status = -EIO;
 
        if (xprt->shutdown)
                goto out;
 
        if (!sock) {
-               /* start from scratch */
-               if ((err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
-                       dprintk("RPC:       can't create TCP transport socket (%d).\n", -err);
+               clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
+               sock = create_sock(xprt, transport);
+               if (IS_ERR(sock)) {
+                       status = PTR_ERR(sock);
                        goto out;
                }
-               xs_reclassify_socket4(sock);
+       } else {
+               int abort_and_exit;
 
-               if (xs_bind4(transport, sock) < 0) {
-                       sock_release(sock);
-                       goto out;
-               }
-       } else
+               abort_and_exit = test_and_clear_bit(XPRT_CONNECTION_ABORT,
+                               &xprt->state);
                /* "close" the socket, preserving the local port */
-               xs_tcp_reuse_connection(xprt);
+               xs_tcp_reuse_connection(xprt, transport);
+
+               if (abort_and_exit)
+                       goto out_eagain;
+       }
 
        dprintk("RPC:       worker connecting xprt %p to address: %s\n",
                        xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
@@ -1696,83 +1771,104 @@ static void xs_tcp_connect_worker4(struct work_struct *work)
        dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
                        xprt, -status, xprt_connected(xprt),
                        sock->sk->sk_state);
-       if (status < 0) {
-               switch (status) {
-                       case -EINPROGRESS:
-                       case -EALREADY:
-                               goto out_clear;
-                       case -ECONNREFUSED:
-                       case -ECONNRESET:
-                               /* retry with existing socket, after a delay */
-                               break;
-                       default:
-                               /* get rid of existing socket, and retry */
-                               xs_tcp_shutdown(xprt);
-               }
+       switch (status) {
+       case -ECONNREFUSED:
+       case -ECONNRESET:
+       case -ENETUNREACH:
+               /* retry with existing socket, after a delay */
+       case 0:
+       case -EINPROGRESS:
+       case -EALREADY:
+               xprt_clear_connecting(xprt);
+               return;
        }
+       /* get rid of existing socket, and retry */
+       xs_tcp_shutdown(xprt);
+       printk("%s: connect returned unhandled error %d\n",
+                       __func__, status);
+out_eagain:
+       status = -EAGAIN;
 out:
-       xprt_wake_pending_tasks(xprt, status);
-out_clear:
        xprt_clear_connecting(xprt);
+       xprt_wake_pending_tasks(xprt, status);
+}
+
+static struct socket *xs_create_tcp_sock4(struct rpc_xprt *xprt,
+               struct sock_xprt *transport)
+{
+       struct socket *sock;
+       int err;
+
+       /* start from scratch */
+       err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
+       if (err < 0) {
+               dprintk("RPC:       can't create TCP transport socket (%d).\n",
+                               -err);
+               goto out_err;
+       }
+       xs_reclassify_socket4(sock);
+
+       if (xs_bind4(transport, sock) < 0) {
+               sock_release(sock);
+               goto out_err;
+       }
+       return sock;
+out_err:
+       return ERR_PTR(-EIO);
 }
 
 /**
- * xs_tcp_connect_worker6 - connect a TCP socket to a remote endpoint
+ * xs_tcp_connect_worker4 - connect a TCP socket to a remote endpoint
  * @work: RPC transport to connect
  *
  * Invoked by a work queue tasklet.
  */
-static void xs_tcp_connect_worker6(struct work_struct *work)
+static void xs_tcp_connect_worker4(struct work_struct *work)
 {
        struct sock_xprt *transport =
                container_of(work, struct sock_xprt, connect_worker.work);
        struct rpc_xprt *xprt = &transport->xprt;
-       struct socket *sock = transport->sock;
-       int err, status = -EIO;
 
-       if (xprt->shutdown)
-               goto out;
+       xs_tcp_setup_socket(xprt, transport, xs_create_tcp_sock4);
+}
 
-       if (!sock) {
-               /* start from scratch */
-               if ((err = sock_create_kern(PF_INET6, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
-                       dprintk("RPC:       can't create TCP transport socket (%d).\n", -err);
-                       goto out;
-               }
-               xs_reclassify_socket6(sock);
+static struct socket *xs_create_tcp_sock6(struct rpc_xprt *xprt,
+               struct sock_xprt *transport)
+{
+       struct socket *sock;
+       int err;
+
+       /* start from scratch */
+       err = sock_create_kern(PF_INET6, SOCK_STREAM, IPPROTO_TCP, &sock);
+       if (err < 0) {
+               dprintk("RPC:       can't create TCP transport socket (%d).\n",
+                               -err);
+               goto out_err;
+       }
+       xs_reclassify_socket6(sock);
 
-               if (xs_bind6(transport, sock) < 0) {
-                       sock_release(sock);
-                       goto out;
-               }
-       } else
-               /* "close" the socket, preserving the local port */
-               xs_tcp_reuse_connection(xprt);
+       if (xs_bind6(transport, sock) < 0) {
+               sock_release(sock);
+               goto out_err;
+       }
+       return sock;
+out_err:
+       return ERR_PTR(-EIO);
+}
 
-       dprintk("RPC:       worker connecting xprt %p to address: %s\n",
-                       xprt, xprt->address_strings[RPC_DISPLAY_ALL]);
+/**
+ * xs_tcp_connect_worker6 - connect a TCP socket to a remote endpoint
+ * @work: RPC transport to connect
+ *
+ * Invoked by a work queue tasklet.
+ */
+static void xs_tcp_connect_worker6(struct work_struct *work)
+{
+       struct sock_xprt *transport =
+               container_of(work, struct sock_xprt, connect_worker.work);
+       struct rpc_xprt *xprt = &transport->xprt;
 
-       status = xs_tcp_finish_connecting(xprt, sock);
-       dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
-                       xprt, -status, xprt_connected(xprt), sock->sk->sk_state);
-       if (status < 0) {
-               switch (status) {
-                       case -EINPROGRESS:
-                       case -EALREADY:
-                               goto out_clear;
-                       case -ECONNREFUSED:
-                       case -ECONNRESET:
-                               /* retry with existing socket, after a delay */
-                               break;
-                       default:
-                               /* get rid of existing socket, and retry */
-                               xs_tcp_shutdown(xprt);
-               }
-       }
-out:
-       xprt_wake_pending_tasks(xprt, status);
-out_clear:
-       xprt_clear_connecting(xprt);
+       xs_tcp_setup_socket(xprt, transport, xs_create_tcp_sock6);
 }
 
 /**
@@ -1817,9 +1913,6 @@ static void xs_tcp_connect(struct rpc_task *task)
 {
        struct rpc_xprt *xprt = task->tk_xprt;
 
-       /* Initiate graceful shutdown of the socket if not already done */
-       if (test_bit(XPRT_CONNECTED, &xprt->state))
-               xs_tcp_shutdown(xprt);
        /* Exit if we need to wait for socket shutdown to complete */
        if (test_bit(XPRT_CLOSING, &xprt->state))
                return;