SUNRPC: Use shutdown() instead of close() when disconnecting a TCP socket
[safe/jmp/linux-2.6] / net / sunrpc / xprtsock.c
index 7a154e4..a4c0690 100644 (file)
@@ -20,6 +20,7 @@
 
 #include <linux/types.h>
 #include <linux/slab.h>
+#include <linux/module.h>
 #include <linux/capability.h>
 #include <linux/pagemap.h>
 #include <linux/errno.h>
@@ -31,6 +32,7 @@
 #include <linux/tcp.h>
 #include <linux/sunrpc/clnt.h>
 #include <linux/sunrpc/sched.h>
+#include <linux/sunrpc/xprtsock.h>
 #include <linux/file.h>
 
 #include <net/sock.h>
@@ -337,6 +339,10 @@ static void xs_format_ipv4_peer_addresses(struct rpc_xprt *xprt)
                                ntohs(addr->sin_port) & 0xff);
        }
        xprt->address_strings[RPC_DISPLAY_UNIVERSAL_ADDR] = buf;
+
+       xprt->address_strings[RPC_DISPLAY_NETID] =
+               kstrdup(xprt->prot == IPPROTO_UDP ?
+                       RPCBIND_NETID_UDP : RPCBIND_NETID_TCP, GFP_KERNEL);
 }
 
 static void xs_format_ipv6_peer_addresses(struct rpc_xprt *xprt)
@@ -398,6 +404,10 @@ static void xs_format_ipv6_peer_addresses(struct rpc_xprt *xprt)
                                ntohs(addr->sin6_port) & 0xff);
        }
        xprt->address_strings[RPC_DISPLAY_UNIVERSAL_ADDR] = buf;
+
+       xprt->address_strings[RPC_DISPLAY_NETID] =
+               kstrdup(xprt->prot == IPPROTO_UDP ?
+                       RPCBIND_NETID_UDP6 : RPCBIND_NETID_TCP6, GFP_KERNEL);
 }
 
 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
@@ -577,12 +587,13 @@ static int xs_udp_send_request(struct rpc_task *task)
        dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
                        xdr->len - req->rq_bytes_sent, status);
 
-       if (likely(status >= (int) req->rq_slen))
-               return 0;
-
-       /* Still some bytes left; set up for a retry later. */
-       if (status > 0)
+       if (status >= 0) {
+               task->tk_bytes_sent += status;
+               if (status >= req->rq_slen)
+                       return 0;
+               /* Still some bytes left; set up for a retry later. */
                status = -EAGAIN;
+       }
 
        switch (status) {
        case -ENETUNREACH:
@@ -603,6 +614,22 @@ static int xs_udp_send_request(struct rpc_task *task)
        return status;
 }
 
+/**
+ * xs_tcp_shutdown - gracefully shut down a TCP socket
+ * @xprt: transport
+ *
+ * Initiates a graceful shutdown of the TCP socket by calling the
+ * equivalent of shutdown(SHUT_WR);
+ */
+static void xs_tcp_shutdown(struct rpc_xprt *xprt)
+{
+       struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
+       struct socket *sock = transport->sock;
+
+       if (sock != NULL)
+               kernel_sock_shutdown(sock, SHUT_WR);
+}
+
 static inline void xs_encode_tcp_record_marker(struct xdr_buf *buf)
 {
        u32 reclen = buf->len - sizeof(rpc_fraghdr);
@@ -680,7 +707,7 @@ static int xs_tcp_send_request(struct rpc_task *task)
        default:
                dprintk("RPC:       sendmsg returned unrecognized error %d\n",
                        -status);
-               xprt_disconnect(xprt);
+               xs_tcp_shutdown(xprt);
                break;
        }
 
@@ -747,7 +774,9 @@ static void xs_close(struct rpc_xprt *xprt)
        sock_release(sock);
 clear_close_wait:
        smp_mb__before_clear_bit();
+       clear_bit(XPRT_CONNECTED, &xprt->state);
        clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
+       clear_bit(XPRT_CLOSING, &xprt->state);
        smp_mb__after_clear_bit();
 }
 
@@ -769,6 +798,7 @@ static void xs_destroy(struct rpc_xprt *xprt)
        xs_free_peer_addresses(xprt);
        kfree(xprt->slot);
        kfree(xprt);
+       module_put(THIS_MODULE);
 }
 
 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
@@ -826,8 +856,12 @@ static void xs_udp_data_ready(struct sock *sk, int len)
                copied = repsize;
 
        /* Suck it into the iovec, verify checksum if not done by hw. */
-       if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb))
+       if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
+               UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
                goto out_unlock;
+       }
+
+       UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
 
        /* Something worked... */
        dst_confirm(skb->dst);
@@ -1102,15 +1136,30 @@ static void xs_tcp_state_change(struct sock *sk)
                }
                spin_unlock_bh(&xprt->transport_lock);
                break;
-       case TCP_SYN_SENT:
-       case TCP_SYN_RECV:
+       case TCP_FIN_WAIT1:
+               /* The client initiated a shutdown of the socket */
+               set_bit(XPRT_CLOSING, &xprt->state);
+               smp_mb__before_clear_bit();
+               clear_bit(XPRT_CONNECTED, &xprt->state);
+               clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
+               smp_mb__after_clear_bit();
                break;
        case TCP_CLOSE_WAIT:
-               /* Try to schedule an autoclose RPC calls */
-               set_bit(XPRT_CLOSE_WAIT, &xprt->state);
-               if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
-                       queue_work(rpciod_workqueue, &xprt->task_cleanup);
-       default:
+               /* The server initiated a shutdown of the socket */
+               set_bit(XPRT_CLOSING, &xprt->state);
+               xprt_force_disconnect(xprt);
+               break;
+       case TCP_LAST_ACK:
+               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(xprt);
        }
  out:
@@ -1263,34 +1312,53 @@ static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
        }
 }
 
+static unsigned short xs_get_srcport(struct sock_xprt *transport, struct socket *sock)
+{
+       unsigned short port = transport->port;
+
+       if (port == 0 && transport->xprt.resvport)
+               port = xs_get_random_port();
+       return port;
+}
+
+static unsigned short xs_next_srcport(struct sock_xprt *transport, struct socket *sock, unsigned short port)
+{
+       if (transport->port != 0)
+               transport->port = 0;
+       if (!transport->xprt.resvport)
+               return 0;
+       if (port <= xprt_min_resvport || port > xprt_max_resvport)
+               return xprt_max_resvport;
+       return --port;
+}
+
 static int xs_bind4(struct sock_xprt *transport, struct socket *sock)
 {
        struct sockaddr_in myaddr = {
                .sin_family = AF_INET,
        };
        struct sockaddr_in *sa;
-       int err;
-       unsigned short port = transport->port;
+       int err, nloop = 0;
+       unsigned short port = xs_get_srcport(transport, sock);
+       unsigned short last;
 
-       if (!transport->xprt.resvport)
-               port = 0;
        sa = (struct sockaddr_in *)&transport->addr;
        myaddr.sin_addr = sa->sin_addr;
        do {
                myaddr.sin_port = htons(port);
                err = kernel_bind(sock, (struct sockaddr *) &myaddr,
                                                sizeof(myaddr));
-               if (!transport->xprt.resvport)
+               if (port == 0)
                        break;
                if (err == 0) {
                        transport->port = port;
                        break;
                }
-               if (port <= xprt_min_resvport)
-                       port = xprt_max_resvport;
-               else
-                       port--;
-       } while (err == -EADDRINUSE && port != transport->port);
+               last = port;
+               port = xs_next_srcport(transport, sock, port);
+               if (port > last)
+                       nloop++;
+       } while (err == -EADDRINUSE && nloop != 2);
        dprintk("RPC:       %s "NIPQUAD_FMT":%u: %s (%d)\n",
                        __FUNCTION__, NIPQUAD(myaddr.sin_addr),
                        port, err ? "failed" : "ok", err);
@@ -1303,28 +1371,27 @@ static int xs_bind6(struct sock_xprt *transport, struct socket *sock)
                .sin6_family = AF_INET6,
        };
        struct sockaddr_in6 *sa;
-       int err;
-       unsigned short port = transport->port;
+       int err, nloop = 0;
+       unsigned short port = xs_get_srcport(transport, sock);
+       unsigned short last;
 
-       if (!transport->xprt.resvport)
-               port = 0;
        sa = (struct sockaddr_in6 *)&transport->addr;
        myaddr.sin6_addr = sa->sin6_addr;
        do {
                myaddr.sin6_port = htons(port);
                err = kernel_bind(sock, (struct sockaddr *) &myaddr,
                                                sizeof(myaddr));
-               if (!transport->xprt.resvport)
+               if (port == 0)
                        break;
                if (err == 0) {
                        transport->port = port;
                        break;
                }
-               if (port <= xprt_min_resvport)
-                       port = xprt_max_resvport;
-               else
-                       port--;
-       } while (err == -EADDRINUSE && port != transport->port);
+               last = port;
+               port = xs_next_srcport(transport, sock, port);
+               if (port > last)
+                       nloop++;
+       } while (err == -EADDRINUSE && nloop != 2);
        dprintk("RPC:       xs_bind6 "NIP6_FMT":%u: %s (%d)\n",
                NIP6(myaddr.sin6_addr), port, err ? "failed" : "ok", err);
        return err;
@@ -1338,7 +1405,7 @@ static inline void xs_reclassify_socket4(struct socket *sock)
 {
        struct sock *sk = sock->sk;
 
-       BUG_ON(sk->sk_lock.owner != NULL);
+       BUG_ON(sock_owned_by_user(sk));
        sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
                &xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
 }
@@ -1347,7 +1414,7 @@ static inline void xs_reclassify_socket6(struct socket *sock)
 {
        struct sock *sk = sock->sk;
 
-       BUG_ON(sk->sk_lock.owner != NULL);
+       BUG_ON(sock_owned_by_user(sk));
        sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
                &xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
 }
@@ -1586,8 +1653,7 @@ static void xs_tcp_connect_worker4(struct work_struct *work)
                                break;
                        default:
                                /* get rid of existing socket, and retry */
-                               xs_close(xprt);
-                               break;
+                               xs_tcp_shutdown(xprt);
                }
        }
 out:
@@ -1646,8 +1712,7 @@ static void xs_tcp_connect_worker6(struct work_struct *work)
                                break;
                        default:
                                /* get rid of existing socket, and retry */
-                               xs_close(xprt);
-                               break;
+                               xs_tcp_shutdown(xprt);
                }
        }
 out:
@@ -1694,6 +1759,19 @@ static void xs_connect(struct rpc_task *task)
        }
 }
 
+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;
+       xs_connect(task);
+}
+
 /**
  * xs_udp_print_stats - display UDP socket-specifc stats
  * @xprt: rpc_xprt struct containing statistics
@@ -1764,17 +1842,18 @@ static struct rpc_xprt_ops xs_tcp_ops = {
        .release_xprt           = xs_tcp_release_xprt,
        .rpcbind                = rpcb_getport_async,
        .set_port               = xs_set_port,
-       .connect                = xs_connect,
+       .connect                = xs_tcp_connect,
        .buf_alloc              = rpc_malloc,
        .buf_free               = rpc_free,
        .send_request           = xs_tcp_send_request,
        .set_retrans_timeout    = xprt_set_retrans_timeout_def,
-       .close                  = xs_close,
+       .close                  = xs_tcp_shutdown,
        .destroy                = xs_destroy,
        .print_stats            = xs_tcp_print_stats,
 };
 
-static struct rpc_xprt *xs_setup_xprt(struct rpc_xprtsock_create *args, unsigned int slot_table_size)
+static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
+                                     unsigned int slot_table_size)
 {
        struct rpc_xprt *xprt;
        struct sock_xprt *new;
@@ -1805,7 +1884,6 @@ static struct rpc_xprt *xs_setup_xprt(struct rpc_xprtsock_create *args, unsigned
        xprt->addrlen = args->addrlen;
        if (args->srcaddr)
                memcpy(&new->addr, args->srcaddr, args->addrlen);
-       new->port = xs_get_random_port();
 
        return xprt;
 }
@@ -1815,7 +1893,7 @@ static struct rpc_xprt *xs_setup_xprt(struct rpc_xprtsock_create *args, unsigned
  * @args: rpc transport creation arguments
  *
  */
-struct rpc_xprt *xs_setup_udp(struct rpc_xprtsock_create *args)
+static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
 {
        struct sockaddr *addr = args->dstaddr;
        struct rpc_xprt *xprt;
@@ -1868,7 +1946,12 @@ struct rpc_xprt *xs_setup_udp(struct rpc_xprtsock_create *args)
        dprintk("RPC:       set up transport to address %s\n",
                        xprt->address_strings[RPC_DISPLAY_ALL]);
 
-       return xprt;
+       if (try_module_get(THIS_MODULE))
+               return xprt;
+
+       kfree(xprt->slot);
+       kfree(xprt);
+       return ERR_PTR(-EINVAL);
 }
 
 /**
@@ -1876,7 +1959,7 @@ struct rpc_xprt *xs_setup_udp(struct rpc_xprtsock_create *args)
  * @args: rpc transport creation arguments
  *
  */
-struct rpc_xprt *xs_setup_tcp(struct rpc_xprtsock_create *args)
+static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
 {
        struct sockaddr *addr = args->dstaddr;
        struct rpc_xprt *xprt;
@@ -1926,11 +2009,32 @@ struct rpc_xprt *xs_setup_tcp(struct rpc_xprtsock_create *args)
        dprintk("RPC:       set up transport to address %s\n",
                        xprt->address_strings[RPC_DISPLAY_ALL]);
 
-       return xprt;
+       if (try_module_get(THIS_MODULE))
+               return xprt;
+
+       kfree(xprt->slot);
+       kfree(xprt);
+       return ERR_PTR(-EINVAL);
 }
 
+static struct xprt_class       xs_udp_transport = {
+       .list           = LIST_HEAD_INIT(xs_udp_transport.list),
+       .name           = "udp",
+       .owner          = THIS_MODULE,
+       .ident          = IPPROTO_UDP,
+       .setup          = xs_setup_udp,
+};
+
+static struct xprt_class       xs_tcp_transport = {
+       .list           = LIST_HEAD_INIT(xs_tcp_transport.list),
+       .name           = "tcp",
+       .owner          = THIS_MODULE,
+       .ident          = IPPROTO_TCP,
+       .setup          = xs_setup_tcp,
+};
+
 /**
- * init_socket_xprt - set up xprtsock's sysctls
+ * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
  *
  */
 int init_socket_xprt(void)
@@ -1940,11 +2044,14 @@ int init_socket_xprt(void)
                sunrpc_table_header = register_sysctl_table(sunrpc_table);
 #endif
 
+       xprt_register_transport(&xs_udp_transport);
+       xprt_register_transport(&xs_tcp_transport);
+
        return 0;
 }
 
 /**
- * cleanup_socket_xprt - remove xprtsock's sysctls
+ * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
  *
  */
 void cleanup_socket_xprt(void)
@@ -1955,4 +2062,7 @@ void cleanup_socket_xprt(void)
                sunrpc_table_header = NULL;
        }
 #endif
+
+       xprt_unregister_transport(&xs_udp_transport);
+       xprt_unregister_transport(&xs_tcp_transport);
 }