1 files changed, 95 insertions, 266 deletions

diff --git a/fs/dlm/lowcomms-tcp.c b/fs/dlm/lowcomms-tcp.c
index 9be3a440c42a..f1efd17b2614 100644
--- a/fs/dlm/lowcomms-tcp.c
+++ b/fs/dlm/lowcomms-tcp.c
@@ -2,7 +2,7 @@
 *******************************************************************************
 **
 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
-**  Copyright (C) 2004-2006 Red Hat, Inc.  All rights reserved.
+**  Copyright (C) 2004-2007 Red Hat, Inc.  All rights reserved.
 **
 **  This copyrighted material is made available to anyone wishing to use,
 **  modify, copy, or redistribute it subject to the terms and conditions
@@ -96,10 +96,7 @@ static bool cbuf_empty(struct cbuf *cb)
 struct connection {
 	struct socket *sock;	/* NULL if not connected */
 	uint32_t nodeid;	/* So we know who we are in the list */
-	struct rw_semaphore sock_sem; /* Stop connect races */
-	struct list_head read_list;   /* On this list when ready for reading */
-	struct list_head write_list;  /* On this list when ready for writing */
-	struct list_head state_list;  /* On this list when ready to connect */
+	struct mutex sock_mutex;
 	unsigned long flags;	/* bit 1,2 = We are on the read/write lists */
 #define CF_READ_PENDING 1
 #define CF_WRITE_PENDING 2
@@ -112,9 +109,10 @@ struct connection {
 	struct page *rx_page;
 	struct cbuf cb;
 	int retries;
-	atomic_t waiting_requests;
 #define MAX_CONNECT_RETRIES 3
 	struct connection *othercon;
+	struct work_struct rwork; /* Receive workqueue */
+	struct work_struct swork; /* Send workqueue */
 };
 #define sock2con(x) ((struct connection *)(x)->sk_user_data)
 
@@ -131,14 +129,9 @@ struct writequeue_entry {
 
 static struct sockaddr_storage dlm_local_addr;
 
-/* Manage daemons */
-static struct task_struct *recv_task;
-static struct task_struct *send_task;
-
-static wait_queue_t lowcomms_send_waitq_head;
-static DECLARE_WAIT_QUEUE_HEAD(lowcomms_send_waitq);
-static wait_queue_t lowcomms_recv_waitq_head;
-static DECLARE_WAIT_QUEUE_HEAD(lowcomms_recv_waitq);
+/* Work queues */
+static struct workqueue_struct *recv_workqueue;
+static struct workqueue_struct *send_workqueue;
 
 /* An array of pointers to connections, indexed by NODEID */
 static struct connection **connections;
@@ -146,17 +139,8 @@ static DECLARE_MUTEX(connections_lock);
 static struct kmem_cache *con_cache;
 static int conn_array_size;
 
-/* List of sockets that have reads pending */
-static LIST_HEAD(read_sockets);
-static DEFINE_SPINLOCK(read_sockets_lock);
-
-/* List of sockets which have writes pending */
-static LIST_HEAD(write_sockets);
-static DEFINE_SPINLOCK(write_sockets_lock);
-
-/* List of sockets which have connects pending */
-static LIST_HEAD(state_sockets);
-static DEFINE_SPINLOCK(state_sockets_lock);
+static void process_recv_sockets(struct work_struct *work);
+static void process_send_sockets(struct work_struct *work);
 
 static struct connection *nodeid2con(int nodeid, gfp_t allocation)
 {
@@ -186,9 +170,11 @@ static struct connection *nodeid2con(int nodeid, gfp_t allocation)
 			goto finish;
 
 		con->nodeid = nodeid;
-		init_rwsem(&con->sock_sem);
+		mutex_init(&con->sock_mutex);
 		INIT_LIST_HEAD(&con->writequeue);
 		spin_lock_init(&con->writequeue_lock);
+		INIT_WORK(&con->swork, process_send_sockets);
+		INIT_WORK(&con->rwork, process_recv_sockets);
 
 		connections[nodeid] = con;
 	}
@@ -203,41 +189,22 @@ static void lowcomms_data_ready(struct sock *sk, int count_unused)
 {
 	struct connection *con = sock2con(sk);
 
-	atomic_inc(&con->waiting_requests);
-	if (test_and_set_bit(CF_READ_PENDING, &con->flags))
-		return;
-
-	spin_lock_bh(&read_sockets_lock);
-	list_add_tail(&con->read_list, &read_sockets);
-	spin_unlock_bh(&read_sockets_lock);
-
-	wake_up_interruptible(&lowcomms_recv_waitq);
+	if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
+		queue_work(recv_workqueue, &con->rwork);
 }
 
 static void lowcomms_write_space(struct sock *sk)
 {
 	struct connection *con = sock2con(sk);
 
-	if (test_and_set_bit(CF_WRITE_PENDING, &con->flags))
-		return;
-
-	spin_lock_bh(&write_sockets_lock);
-	list_add_tail(&con->write_list, &write_sockets);
-	spin_unlock_bh(&write_sockets_lock);
-
-	wake_up_interruptible(&lowcomms_send_waitq);
+	if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags))
+		queue_work(send_workqueue, &con->swork);
 }
 
 static inline void lowcomms_connect_sock(struct connection *con)
 {
-	if (test_and_set_bit(CF_CONNECT_PENDING, &con->flags))
-		return;
-
-	spin_lock_bh(&state_sockets_lock);
-	list_add_tail(&con->state_list, &state_sockets);
-	spin_unlock_bh(&state_sockets_lock);
-
-	wake_up_interruptible(&lowcomms_send_waitq);
+	if (!test_and_set_bit(CF_CONNECT_PENDING, &con->flags))
+		queue_work(send_workqueue, &con->swork);
 }
 
 static void lowcomms_state_change(struct sock *sk)
@@ -279,7 +246,7 @@ static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
 /* Close a remote connection and tidy up */
 static void close_connection(struct connection *con, bool and_other)
 {
-	down_write(&con->sock_sem);
+	mutex_lock(&con->sock_mutex);
 
 	if (con->sock) {
 		sock_release(con->sock);
@@ -294,7 +261,7 @@ static void close_connection(struct connection *con, bool and_other)
 		con->rx_page = NULL;
 	}
 	con->retries = 0;
-	up_write(&con->sock_sem);
+	mutex_unlock(&con->sock_mutex);
 }
 
 /* Data received from remote end */
@@ -308,10 +275,13 @@ static int receive_from_sock(struct connection *con)
 	int r;
 	int call_again_soon = 0;
 
-	down_read(&con->sock_sem);
+	mutex_lock(&con->sock_mutex);
+
+	if (con->sock == NULL) {
+		ret = -EAGAIN;
+		goto out_close;
+	}
 
-	if (con->sock == NULL)
-		goto out;
 	if (con->rx_page == NULL) {
 		/*
 		 * This doesn't need to be atomic, but I think it should
@@ -359,6 +329,9 @@ static int receive_from_sock(struct connection *con)
 
 	if (ret <= 0)
 		goto out_close;
+	if (ret == -EAGAIN)
+		goto out_resched;
+
 	if (ret == len)
 		call_again_soon = 1;
 	cbuf_add(&con->cb, ret);
@@ -381,24 +354,26 @@ static int receive_from_sock(struct connection *con)
 		con->rx_page = NULL;
 	}
 
-out:
 	if (call_again_soon)
 		goto out_resched;
-	up_read(&con->sock_sem);
+	mutex_unlock(&con->sock_mutex);
 	return 0;
 
 out_resched:
-	lowcomms_data_ready(con->sock->sk, 0);
-	up_read(&con->sock_sem);
-	cond_resched();
-	return 0;
+	if (!test_and_set_bit(CF_READ_PENDING, &con->flags))
+		queue_work(recv_workqueue, &con->rwork);
+	mutex_unlock(&con->sock_mutex);
+	return -EAGAIN;
 
 out_close:
-	up_read(&con->sock_sem);
+	mutex_unlock(&con->sock_mutex);
 	if (ret != -EAGAIN && !test_bit(CF_IS_OTHERCON, &con->flags)) {
 		close_connection(con, false);
 		/* Reconnect when there is something to send */
 	}
+	/* Don't return success if we really got EOF */
+	if (ret == 0)
+		ret = -EAGAIN;
 
 	return ret;
 }
@@ -412,6 +387,7 @@ static int accept_from_sock(struct connection *con)
 	int len;
 	int nodeid;
 	struct connection *newcon;
+	struct connection *addcon;
 
 	memset(&peeraddr, 0, sizeof(peeraddr));
 	result = sock_create_kern(dlm_local_addr.ss_family, SOCK_STREAM,
@@ -419,7 +395,7 @@ static int accept_from_sock(struct connection *con)
 	if (result < 0)
 		return -ENOMEM;
 
-	down_read(&con->sock_sem);
+	mutex_lock_nested(&con->sock_mutex, 0);
 
 	result = -ENOTCONN;
 	if (con->sock == NULL)
@@ -445,7 +421,7 @@ static int accept_from_sock(struct connection *con)
 	if (dlm_addr_to_nodeid(&peeraddr, &nodeid)) {
 		printk("dlm: connect from non cluster node\n");
 		sock_release(newsock);
-		up_read(&con->sock_sem);
+		mutex_unlock(&con->sock_mutex);
 		return -1;
 	}
 
@@ -462,7 +438,7 @@ static int accept_from_sock(struct connection *con)
 		result = -ENOMEM;
 		goto accept_err;
 	}
-	down_write(&newcon->sock_sem);
+	mutex_lock_nested(&newcon->sock_mutex, 1);
 	if (newcon->sock) {
 		struct connection *othercon = newcon->othercon;
 
@@ -470,41 +446,45 @@ static int accept_from_sock(struct connection *con)
 			othercon = kmem_cache_zalloc(con_cache, GFP_KERNEL);
 			if (!othercon) {
 				printk("dlm: failed to allocate incoming socket\n");
-				up_write(&newcon->sock_sem);
+				mutex_unlock(&newcon->sock_mutex);
 				result = -ENOMEM;
 				goto accept_err;
 			}
 			othercon->nodeid = nodeid;
 			othercon->rx_action = receive_from_sock;
-			init_rwsem(&othercon->sock_sem);
+			mutex_init(&othercon->sock_mutex);
+			INIT_WORK(&othercon->swork, process_send_sockets);
+			INIT_WORK(&othercon->rwork, process_recv_sockets);
 			set_bit(CF_IS_OTHERCON, &othercon->flags);
 			newcon->othercon = othercon;
 		}
 		othercon->sock = newsock;
 		newsock->sk->sk_user_data = othercon;
 		add_sock(newsock, othercon);
+		addcon = othercon;
 	}
 	else {
 		newsock->sk->sk_user_data = newcon;
 		newcon->rx_action = receive_from_sock;
 		add_sock(newsock, newcon);
-
+		addcon = newcon;
 	}
 
-	up_write(&newcon->sock_sem);
+	mutex_unlock(&newcon->sock_mutex);
 
 	/*
 	 * Add it to the active queue in case we got data
 	 * beween processing the accept adding the socket
 	 * to the read_sockets list
 	 */
-	lowcomms_data_ready(newsock->sk, 0);
-	up_read(&con->sock_sem);
+	if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags))
+		queue_work(recv_workqueue, &addcon->rwork);
+	mutex_unlock(&con->sock_mutex);
 
 	return 0;
 
 accept_err:
-	up_read(&con->sock_sem);
+	mutex_unlock(&con->sock_mutex);
 	sock_release(newsock);
 
 	if (result != -EAGAIN)
@@ -525,7 +505,7 @@ static void connect_to_sock(struct connection *con)
 		return;
 	}
 
-	down_write(&con->sock_sem);
+	mutex_lock(&con->sock_mutex);
 	if (con->retries++ > MAX_CONNECT_RETRIES)
 		goto out;
 
@@ -548,7 +528,7 @@ static void connect_to_sock(struct connection *con)
 	sock->sk->sk_user_data = con;
 	con->rx_action = receive_from_sock;
 
-	make_sockaddr(&saddr, dlm_config.tcp_port, &addr_len);
+	make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len);
 
 	add_sock(sock, con);
 
@@ -577,7 +557,7 @@ out_err:
 		result = 0;
 	}
 out:
-	up_write(&con->sock_sem);
+	mutex_unlock(&con->sock_mutex);
 	return;
 }
 
@@ -616,10 +596,10 @@ static struct socket *create_listen_sock(struct connection *con,
 	con->sock = sock;
 
 	/* Bind to our port */
-	make_sockaddr(saddr, dlm_config.tcp_port, &addr_len);
+	make_sockaddr(saddr, dlm_config.ci_tcp_port, &addr_len);
 	result = sock->ops->bind(sock, (struct sockaddr *) saddr, addr_len);
 	if (result < 0) {
-		printk("dlm: Can't bind to port %d\n", dlm_config.tcp_port);
+		printk("dlm: Can't bind to port %d\n", dlm_config.ci_tcp_port);
 		sock_release(sock);
 		sock = NULL;
 		con->sock = NULL;
@@ -638,7 +618,7 @@ static struct socket *create_listen_sock(struct connection *con,
 
 	result = sock->ops->listen(sock, 5);
 	if (result < 0) {
-		printk("dlm: Can't listen on port %d\n", dlm_config.tcp_port);
+		printk("dlm: Can't listen on port %d\n", dlm_config.ci_tcp_port);
 		sock_release(sock);
 		sock = NULL;
 		goto create_out;
@@ -709,6 +689,7 @@ void *dlm_lowcomms_get_buffer(int nodeid, int len,
 	if (!con)
 		return NULL;
 
+	spin_lock(&con->writequeue_lock);
 	e = list_entry(con->writequeue.prev, struct writequeue_entry, list);
 	if ((&e->list == &con->writequeue) ||
 	    (PAGE_CACHE_SIZE - e->end < len)) {
@@ -747,6 +728,7 @@ void dlm_lowcomms_commit_buffer(void *mh)
 	struct connection *con = e->con;
 	int users;
 
+	spin_lock(&con->writequeue_lock);
 	users = --e->users;
 	if (users)
 		goto out;
@@ -754,12 +736,8 @@ void dlm_lowcomms_commit_buffer(void *mh)
 	kunmap(e->page);
 	spin_unlock(&con->writequeue_lock);
 
-	if (test_and_set_bit(CF_WRITE_PENDING, &con->flags) == 0) {
-		spin_lock_bh(&write_sockets_lock);
-		list_add_tail(&con->write_list, &write_sockets);
-		spin_unlock_bh(&write_sockets_lock);
-
-		wake_up_interruptible(&lowcomms_send_waitq);
+	if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) {
+		queue_work(send_workqueue, &con->swork);
 	}
 	return;
 
@@ -783,7 +761,7 @@ static void send_to_sock(struct connection *con)
 	struct writequeue_entry *e;
 	int len, offset;
 
-	down_read(&con->sock_sem);
+	mutex_lock(&con->sock_mutex);
 	if (con->sock == NULL)
 		goto out_connect;
 
@@ -800,6 +778,7 @@ static void send_to_sock(struct connection *con)
 		offset = e->offset;
 		BUG_ON(len == 0 && e->users == 0);
 		spin_unlock(&con->writequeue_lock);
+		kmap(e->page);
 
 		ret = 0;
 		if (len) {
@@ -828,18 +807,18 @@ static void send_to_sock(struct connection *con)
 	}
 	spin_unlock(&con->writequeue_lock);
 out:
-	up_read(&con->sock_sem);
+	mutex_unlock(&con->sock_mutex);
 	return;
 
 send_error:
-	up_read(&con->sock_sem);
+	mutex_unlock(&con->sock_mutex);
 	close_connection(con, false);
 	lowcomms_connect_sock(con);
 	return;
 
 out_connect:
-	up_read(&con->sock_sem);
-	lowcomms_connect_sock(con);
+	mutex_unlock(&con->sock_mutex);
+	connect_to_sock(con);
 	return;
 }
 
@@ -872,7 +851,6 @@ int dlm_lowcomms_close(int nodeid)
 	if (con) {
 		clean_one_writequeue(con);
 		close_connection(con, true);
-		atomic_set(&con->waiting_requests, 0);
 	}
 	return 0;
 
@@ -880,102 +858,29 @@ out:
 	return -1;
 }
 
-/* API send message call, may queue the request */
-/* N.B. This is the old interface - use the new one for new calls */
-int lowcomms_send_message(int nodeid, char *buf, int len, gfp_t allocation)
-{
-	struct writequeue_entry *e;
-	char *b;
-
-	e = dlm_lowcomms_get_buffer(nodeid, len, allocation, &b);
-	if (e) {
-		memcpy(b, buf, len);
-		dlm_lowcomms_commit_buffer(e);
-		return 0;
-	}
-	return -ENOBUFS;
-}
-
 /* Look for activity on active sockets */
-static void process_sockets(void)
+static void process_recv_sockets(struct work_struct *work)
 {
-	struct list_head *list;
-	struct list_head *temp;
-	int count = 0;
-
-	spin_lock_bh(&read_sockets_lock);
-	list_for_each_safe(list, temp, &read_sockets) {
+	struct connection *con = container_of(work, struct connection, rwork);
+	int err;
 
-		struct connection *con =
-			list_entry(list, struct connection, read_list);
-		list_del(&con->read_list);
-		clear_bit(CF_READ_PENDING, &con->flags);
-
-		spin_unlock_bh(&read_sockets_lock);
-
-		/* This can reach zero if we are processing requests
-		 * as they come in.
-		 */
-		if (atomic_read(&con->waiting_requests) == 0) {
-			spin_lock_bh(&read_sockets_lock);
-			continue;
-		}
-
-		do {
-			con->rx_action(con);
-
-			/* Don't starve out everyone else */
-			if (++count >= MAX_RX_MSG_COUNT) {
-				cond_resched();
-				count = 0;
-			}
-
-		} while (!atomic_dec_and_test(&con->waiting_requests) &&
-			 !kthread_should_stop());
-
-		spin_lock_bh(&read_sockets_lock);
-	}
-	spin_unlock_bh(&read_sockets_lock);
+	clear_bit(CF_READ_PENDING, &con->flags);
+	do {
+		err = con->rx_action(con);
+	} while (!err);
 }
 
-/* Try to send any messages that are pending
- */
-static void process_output_queue(void)
-{
-	struct list_head *list;
-	struct list_head *temp;
-
-	spin_lock_bh(&write_sockets_lock);
-	list_for_each_safe(list, temp, &write_sockets) {
-		struct connection *con =
-			list_entry(list, struct connection, write_list);
-		clear_bit(CF_WRITE_PENDING, &con->flags);
-		list_del(&con->write_list);
-
-		spin_unlock_bh(&write_sockets_lock);
-		send_to_sock(con);
-		spin_lock_bh(&write_sockets_lock);
-	}
-	spin_unlock_bh(&write_sockets_lock);
-}
 
-static void process_state_queue(void)
+static void process_send_sockets(struct work_struct *work)
 {
-	struct list_head *list;
-	struct list_head *temp;
-
-	spin_lock_bh(&state_sockets_lock);
-	list_for_each_safe(list, temp, &state_sockets) {
-		struct connection *con =
-			list_entry(list, struct connection, state_list);
-		list_del(&con->state_list);
-		clear_bit(CF_CONNECT_PENDING, &con->flags);
-		spin_unlock_bh(&state_sockets_lock);
+	struct connection *con = container_of(work, struct connection, swork);
 
+	if (test_and_clear_bit(CF_CONNECT_PENDING, &con->flags)) {
 		connect_to_sock(con);
-		spin_lock_bh(&state_sockets_lock);
 	}
-	spin_unlock_bh(&state_sockets_lock);
+
+	clear_bit(CF_WRITE_PENDING, &con->flags);
+	send_to_sock(con);
 }
 
 
@@ -992,109 +897,33 @@ static void clean_writequeues(void)
 	}
 }
 
-static int read_list_empty(void)
+static void work_stop(void)
 {
-	int status;
-
-	spin_lock_bh(&read_sockets_lock);
-	status = list_empty(&read_sockets);
-	spin_unlock_bh(&read_sockets_lock);
-
-	return status;
-}
-
-/* DLM Transport comms receive daemon */
-static int dlm_recvd(void *data)
-{
-	init_waitqueue_entry(&lowcomms_recv_waitq_head, current);
-	add_wait_queue(&lowcomms_recv_waitq, &lowcomms_recv_waitq_head);
-
-	while (!kthread_should_stop()) {
-		set_current_state(TASK_INTERRUPTIBLE);
-		if (read_list_empty())
-			cond_resched();
-		set_current_state(TASK_RUNNING);
-
-		process_sockets();
-	}
-
-	return 0;
+	destroy_workqueue(recv_workqueue);
+	destroy_workqueue(send_workqueue);
 }
 
-static int write_and_state_lists_empty(void)
+static int work_start(void)
 {
-	int status;
-
-	spin_lock_bh(&write_sockets_lock);
-	status = list_empty(&write_sockets);
-	spin_unlock_bh(&write_sockets_lock);
-
-	spin_lock_bh(&state_sockets_lock);
-	if (list_empty(&state_sockets) == 0)
-		status = 0;
-	spin_unlock_bh(&state_sockets_lock);
-
-	return status;
-}
-
-/* DLM Transport send daemon */
-static int dlm_sendd(void *data)
-{
-	init_waitqueue_entry(&lowcomms_send_waitq_head, current);
-	add_wait_queue(&lowcomms_send_waitq, &lowcomms_send_waitq_head);
-
-	while (!kthread_should_stop()) {
-		set_current_state(TASK_INTERRUPTIBLE);
-		if (write_and_state_lists_empty())
-			cond_resched();
-		set_current_state(TASK_RUNNING);
-
-		process_state_queue();
-		process_output_queue();
-	}
-
-	return 0;
-}
-
-static void daemons_stop(void)
-{
-	kthread_stop(recv_task);
-	kthread_stop(send_task);
-}
-
-static int daemons_start(void)
-{
-	struct task_struct *p;
 	int error;
-
-	p = kthread_run(dlm_recvd, NULL, "dlm_recvd");
-	error = IS_ERR(p);
+	recv_workqueue = create_workqueue("dlm_recv");
+	error = IS_ERR(recv_workqueue);
 	if (error) {
-		log_print("can't start dlm_recvd %d", error);
+		log_print("can't start dlm_recv %d", error);
 		return error;
 	}
-	recv_task = p;
 
-	p = kthread_run(dlm_sendd, NULL, "dlm_sendd");
-	error = IS_ERR(p);
+	send_workqueue = create_singlethread_workqueue("dlm_send");
+	error = IS_ERR(send_workqueue);
 	if (error) {
-		log_print("can't start dlm_sendd %d", error);
-		kthread_stop(recv_task);
+		log_print("can't start dlm_send %d", error);
+		destroy_workqueue(recv_workqueue);
 		return error;
 	}
-	send_task = p;
 
 	return 0;
 }
 
-/*
- * Return the largest buffer size we can cope with.
- */
-int lowcomms_max_buffer_size(void)
-{
-	return PAGE_CACHE_SIZE;
-}
-
 void dlm_lowcomms_stop(void)
 {
 	int i;
@@ -1107,7 +936,7 @@ void dlm_lowcomms_stop(void)
 			connections[i]->flags |= 0xFF;
 	}
 
-	daemons_stop();
+	work_stop();
 	clean_writequeues();
 
 	for (i = 0; i < conn_array_size; i++) {
@@ -1159,7 +988,7 @@ int dlm_lowcomms_start(void)
 	if (error)
 		goto fail_unlisten;
 
-	error = daemons_start();
+	error = work_start();
 	if (error)
 		goto fail_unlisten;