DLM: Fix saving of NULL callbacks
[linux-2.6-microblaze.git] / fs / dlm / lowcomms.c
index 4813d0e..32b534f 100644 (file)
@@ -106,8 +106,6 @@ struct connection {
        struct mutex sock_mutex;
        unsigned long flags;
 #define CF_READ_PENDING 1
-#define CF_WRITE_PENDING 2
-#define CF_CONNECT_PENDING 3
 #define CF_INIT_PENDING 4
 #define CF_IS_OTHERCON 5
 #define CF_CLOSE 6
@@ -124,10 +122,6 @@ struct connection {
        struct connection *othercon;
        struct work_struct rwork; /* Receive workqueue */
        struct work_struct swork; /* Send workqueue */
-       void (*orig_error_report)(struct sock *);
-       void (*orig_data_ready)(struct sock *);
-       void (*orig_state_change)(struct sock *);
-       void (*orig_write_space)(struct sock *);
 };
 #define sock2con(x) ((struct connection *)(x)->sk_user_data)
 
@@ -150,6 +144,13 @@ struct dlm_node_addr {
        struct sockaddr_storage *addr[DLM_MAX_ADDR_COUNT];
 };
 
+static struct listen_sock_callbacks {
+       void (*sk_error_report)(struct sock *);
+       void (*sk_data_ready)(struct sock *);
+       void (*sk_state_change)(struct sock *);
+       void (*sk_write_space)(struct sock *);
+} listen_sock;
+
 static LIST_HEAD(dlm_node_addrs);
 static DEFINE_SPINLOCK(dlm_node_addrs_spin);
 
@@ -427,16 +428,15 @@ static void lowcomms_write_space(struct sock *sk)
                clear_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags);
        }
 
-       if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags))
-               queue_work(send_workqueue, &con->swork);
+       queue_work(send_workqueue, &con->swork);
 }
 
 static inline void lowcomms_connect_sock(struct connection *con)
 {
        if (test_bit(CF_CLOSE, &con->flags))
                return;
-       if (!test_and_set_bit(CF_CONNECT_PENDING, &con->flags))
-               queue_work(send_workqueue, &con->swork);
+       queue_work(send_workqueue, &con->swork);
+       cond_resched();
 }
 
 static void lowcomms_state_change(struct sock *sk)
@@ -480,7 +480,7 @@ static void lowcomms_error_report(struct sock *sk)
        if (con == NULL)
                goto out;
 
-       orig_report = con->orig_error_report;
+       orig_report = listen_sock.sk_error_report;
        if (con->sock == NULL ||
            kernel_getpeername(con->sock, (struct sockaddr *)&saddr, &buflen)) {
                printk_ratelimited(KERN_ERR "dlm: node %d: socket error "
@@ -517,22 +517,26 @@ out:
 }
 
 /* Note: sk_callback_lock must be locked before calling this function. */
-static void save_callbacks(struct connection *con, struct sock *sk)
+static void save_listen_callbacks(struct socket *sock)
 {
-       con->orig_data_ready = sk->sk_data_ready;
-       con->orig_state_change = sk->sk_state_change;
-       con->orig_write_space = sk->sk_write_space;
-       con->orig_error_report = sk->sk_error_report;
+       struct sock *sk = sock->sk;
+
+       listen_sock.sk_data_ready = sk->sk_data_ready;
+       listen_sock.sk_state_change = sk->sk_state_change;
+       listen_sock.sk_write_space = sk->sk_write_space;
+       listen_sock.sk_error_report = sk->sk_error_report;
 }
 
-static void restore_callbacks(struct connection *con, struct sock *sk)
+static void restore_callbacks(struct socket *sock)
 {
+       struct sock *sk = sock->sk;
+
        write_lock_bh(&sk->sk_callback_lock);
        sk->sk_user_data = NULL;
-       sk->sk_data_ready = con->orig_data_ready;
-       sk->sk_state_change = con->orig_state_change;
-       sk->sk_write_space = con->orig_write_space;
-       sk->sk_error_report = con->orig_error_report;
+       sk->sk_data_ready = listen_sock.sk_data_ready;
+       sk->sk_state_change = listen_sock.sk_state_change;
+       sk->sk_write_space = listen_sock.sk_write_space;
+       sk->sk_error_report = listen_sock.sk_error_report;
        write_unlock_bh(&sk->sk_callback_lock);
 }
 
@@ -545,8 +549,6 @@ static void add_sock(struct socket *sock, struct connection *con, bool save_cb)
        con->sock = sock;
 
        sk->sk_user_data = con;
-       if (save_cb)
-               save_callbacks(con, sk);
        /* Install a data_ready callback */
        sk->sk_data_ready = lowcomms_data_ready;
        sk->sk_write_space = lowcomms_write_space;
@@ -579,8 +581,6 @@ static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
 static void close_connection(struct connection *con, bool and_other,
                             bool tx, bool rx)
 {
-       clear_bit(CF_CONNECT_PENDING, &con->flags);
-       clear_bit(CF_WRITE_PENDING, &con->flags);
        if (tx && cancel_work_sync(&con->swork))
                log_print("canceled swork for node %d", con->nodeid);
        if (rx && cancel_work_sync(&con->rwork))
@@ -588,8 +588,7 @@ static void close_connection(struct connection *con, bool and_other,
 
        mutex_lock(&con->sock_mutex);
        if (con->sock) {
-               if (!test_bit(CF_IS_OTHERCON, &con->flags))
-                       restore_callbacks(con, con->sock->sk);
+               restore_callbacks(con->sock);
                sock_release(con->sock);
                con->sock = NULL;
        }
@@ -1079,7 +1078,6 @@ static void sctp_connect_to_sock(struct connection *con)
        if (result == 0)
                goto out;
 
-
 bind_err:
        con->sock = NULL;
        sock_release(sock);
@@ -1098,14 +1096,12 @@ socket_err:
                          con->retries, result);
                mutex_unlock(&con->sock_mutex);
                msleep(1000);
-               clear_bit(CF_CONNECT_PENDING, &con->flags);
                lowcomms_connect_sock(con);
                return;
        }
 
 out:
        mutex_unlock(&con->sock_mutex);
-       set_bit(CF_WRITE_PENDING, &con->flags);
 }
 
 /* Connect a new socket to its peer */
@@ -1194,13 +1190,11 @@ out_err:
                          con->retries, result);
                mutex_unlock(&con->sock_mutex);
                msleep(1000);
-               clear_bit(CF_CONNECT_PENDING, &con->flags);
                lowcomms_connect_sock(con);
                return;
        }
 out:
        mutex_unlock(&con->sock_mutex);
-       set_bit(CF_WRITE_PENDING, &con->flags);
        return;
 }
 
@@ -1236,7 +1230,7 @@ static struct socket *tcp_create_listen_sock(struct connection *con,
                log_print("Failed to set SO_REUSEADDR on socket: %d", result);
        }
        sock->sk->sk_user_data = con;
-
+       save_listen_callbacks(sock);
        con->rx_action = tcp_accept_from_sock;
        con->connect_action = tcp_connect_to_sock;
 
@@ -1320,6 +1314,7 @@ static int sctp_listen_for_all(void)
        write_lock_bh(&sock->sk->sk_callback_lock);
        /* Init con struct */
        sock->sk->sk_user_data = con;
+       save_listen_callbacks(sock);
        con->sock = sock;
        con->sock->sk->sk_data_ready = lowcomms_data_ready;
        con->rx_action = sctp_accept_from_sock;
@@ -1456,9 +1451,7 @@ void dlm_lowcomms_commit_buffer(void *mh)
        e->len = e->end - e->offset;
        spin_unlock(&con->writequeue_lock);
 
-       if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) {
-               queue_work(send_workqueue, &con->swork);
-       }
+       queue_work(send_workqueue, &con->swork);
        return;
 
 out:
@@ -1528,12 +1521,15 @@ out:
 send_error:
        mutex_unlock(&con->sock_mutex);
        close_connection(con, false, false, true);
-       lowcomms_connect_sock(con);
+       /* Requeue the send work. When the work daemon runs again, it will try
+          a new connection, then call this function again. */
+       queue_work(send_workqueue, &con->swork);
        return;
 
 out_connect:
        mutex_unlock(&con->sock_mutex);
-       lowcomms_connect_sock(con);
+       queue_work(send_workqueue, &con->swork);
+       cond_resched();
 }
 
 static void clean_one_writequeue(struct connection *con)
@@ -1593,9 +1589,9 @@ static void process_send_sockets(struct work_struct *work)
 {
        struct connection *con = container_of(work, struct connection, swork);
 
-       if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags))
+       if (con->sock == NULL) /* not mutex protected so check it inside too */
                con->connect_action(con);
-       if (test_and_clear_bit(CF_WRITE_PENDING, &con->flags))
+       if (!list_empty(&con->writequeue))
                send_to_sock(con);
 }