--- /dev/null
+/******************************************************************************
+*******************************************************************************
+**
+** Copyright (C) Sistina Software, Inc. 1997-2003 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
+** of the GNU General Public License v.2.
+**
+*******************************************************************************
+******************************************************************************/
+
+/*
+ * lowcomms.c
+ *
+ * This is the "low-level" comms layer.
+ *
+ * It is responsible for sending/receiving messages
+ * from other nodes in the cluster.
+ *
+ * Cluster nodes are referred to by their nodeids. nodeids are
+ * simply 32 bit numbers to the locking module - if they need to
+ * be expanded for the cluster infrastructure then that is it's
+ * responsibility. It is this layer's
+ * responsibility to resolve these into IP address or
+ * whatever it needs for inter-node communication.
+ *
+ * The comms level is two kernel threads that deal mainly with
+ * the receiving of messages from other nodes and passing them
+ * up to the mid-level comms layer (which understands the
+ * message format) for execution by the locking core, and
+ * a send thread which does all the setting up of connections
+ * to remote nodes and the sending of data. Threads are not allowed
+ * to send their own data because it may cause them to wait in times
+ * of high load. Also, this way, the sending thread can collect together
+ * messages bound for one node and send them in one block.
+ *
+ * I don't see any problem with the recv thread executing the locking
+ * code on behalf of remote processes as the locking code is
+ * short, efficient and never waits.
+ *
+ */
+
+
+#include <asm/ioctls.h>
+#include <net/sock.h>
+#include <net/tcp.h>
+#include <linux/pagemap.h>
+
+#include "dlm_internal.h"
+#include "lowcomms.h"
+#include "midcomms.h"
+#include "config.h"
+
+struct cbuf {
+ unsigned int base;
+ unsigned int len;
+ unsigned int mask;
+};
+
+#define NODE_INCREMENT 32
+static void cbuf_add(struct cbuf *cb, int n)
+{
+ cb->len += n;
+}
+
+static int cbuf_data(struct cbuf *cb)
+{
+ return ((cb->base + cb->len) & cb->mask);
+}
+
+static void cbuf_init(struct cbuf *cb, int size)
+{
+ cb->base = cb->len = 0;
+ cb->mask = size-1;
+}
+
+static void cbuf_eat(struct cbuf *cb, int n)
+{
+ cb->len -= n;
+ cb->base += n;
+ cb->base &= cb->mask;
+}
+
+static bool cbuf_empty(struct cbuf *cb)
+{
+ return cb->len == 0;
+}
+
+/* Maximum number of incoming messages to process before
+ doing a cond_resched()
+*/
+#define MAX_RX_MSG_COUNT 25
+
+struct connection {
+ struct socket *sock; /* NULL if not connected */
+ uint32_t nodeid; /* So we know who we are in the list */
+ 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
+#define CF_CONNECT_PENDING 3
+#define CF_IS_OTHERCON 4
+ struct list_head writequeue; /* List of outgoing writequeue_entries */
+ struct list_head listenlist; /* List of allocated listening sockets */
+ spinlock_t writequeue_lock;
+ int (*rx_action) (struct connection *); /* What to do when active */
+ struct page *rx_page;
+ struct cbuf cb;
+ int retries;
+#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)
+
+/* An entry waiting to be sent */
+struct writequeue_entry {
+ struct list_head list;
+ struct page *page;
+ int offset;
+ int len;
+ int end;
+ int users;
+ struct connection *con;
+};
+
+static struct sockaddr_storage dlm_local_addr;
+
+/* 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;
+static DECLARE_MUTEX(connections_lock);
+static struct kmem_cache *con_cache;
+static int conn_array_size;
+
+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)
+{
+ struct connection *con = NULL;
+
+ down(&connections_lock);
+ if (nodeid >= conn_array_size) {
+ int new_size = nodeid + NODE_INCREMENT;
+ struct connection **new_conns;
+
+ new_conns = kzalloc(sizeof(struct connection *) *
+ new_size, allocation);
+ if (!new_conns)
+ goto finish;
+
+ memcpy(new_conns, connections, sizeof(struct connection *) * conn_array_size);
+ conn_array_size = new_size;
+ kfree(connections);
+ connections = new_conns;
+
+ }
+
+ con = connections[nodeid];
+ if (con == NULL && allocation) {
+ con = kmem_cache_zalloc(con_cache, allocation);
+ if (!con)
+ goto finish;
+
+ con->nodeid = nodeid;
+ 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;
+ }
+
+finish:
+ up(&connections_lock);
+ return con;
+}
+
+/* Data available on socket or listen socket received a connect */
+static void lowcomms_data_ready(struct sock *sk, int count_unused)
+{
+ struct connection *con = sock2con(sk);
+
+ 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))
+ 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))
+ queue_work(send_workqueue, &con->swork);
+}
+
+static void lowcomms_state_change(struct sock *sk)
+{
+ if (sk->sk_state == TCP_ESTABLISHED)
+ lowcomms_write_space(sk);
+}
+
+/* Make a socket active */
+static int add_sock(struct socket *sock, struct connection *con)
+{
+ con->sock = sock;
+
+ /* Install a data_ready callback */
+ con->sock->sk->sk_data_ready = lowcomms_data_ready;
+ con->sock->sk->sk_write_space = lowcomms_write_space;
+ con->sock->sk->sk_state_change = lowcomms_state_change;
+
+ return 0;
+}
+
+/* Add the port number to an IP6 or 4 sockaddr and return the address
+ length */
+static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
+ int *addr_len)
+{
+ saddr->ss_family = dlm_local_addr.ss_family;
+ if (saddr->ss_family == AF_INET) {
+ struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr;
+ in4_addr->sin_port = cpu_to_be16(port);
+ *addr_len = sizeof(struct sockaddr_in);
+ } else {
+ struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr;
+ in6_addr->sin6_port = cpu_to_be16(port);
+ *addr_len = sizeof(struct sockaddr_in6);
+ }
+}
+
+/* Close a remote connection and tidy up */
+static void close_connection(struct connection *con, bool and_other)
+{
+ mutex_lock(&con->sock_mutex);
+
+ if (con->sock) {
+ sock_release(con->sock);
+ con->sock = NULL;
+ }
+ if (con->othercon && and_other) {
+ /* Will only re-enter once. */
+ close_connection(con->othercon, false);
+ }
+ if (con->rx_page) {
+ __free_page(con->rx_page);
+ con->rx_page = NULL;
+ }
+ con->retries = 0;
+ mutex_unlock(&con->sock_mutex);
+}
+
+/* Data received from remote end */
+static int receive_from_sock(struct connection *con)
+{
+ int ret = 0;
+ struct msghdr msg = {};
+ struct kvec iov[2];
+ unsigned len;
+ int r;
+ int call_again_soon = 0;
+ int nvec;
+
+ mutex_lock(&con->sock_mutex);
+
+ if (con->sock == NULL) {
+ ret = -EAGAIN;
+ goto out_close;
+ }
+
+ if (con->rx_page == NULL) {
+ /*
+ * This doesn't need to be atomic, but I think it should
+ * improve performance if it is.
+ */
+ con->rx_page = alloc_page(GFP_ATOMIC);
+ if (con->rx_page == NULL)
+ goto out_resched;
+ cbuf_init(&con->cb, PAGE_CACHE_SIZE);
+ }
+
+ /*
+ * iov[0] is the bit of the circular buffer between the current end
+ * point (cb.base + cb.len) and the end of the buffer.
+ */
+ iov[0].iov_len = con->cb.base - cbuf_data(&con->cb);
+ iov[0].iov_base = page_address(con->rx_page) + cbuf_data(&con->cb);
+ nvec = 1;
+
+ /*
+ * iov[1] is the bit of the circular buffer between the start of the
+ * buffer and the start of the currently used section (cb.base)
+ */
+ if (cbuf_data(&con->cb) >= con->cb.base) {
+ iov[0].iov_len = PAGE_CACHE_SIZE - cbuf_data(&con->cb);
+ iov[1].iov_len = con->cb.base;
+ iov[1].iov_base = page_address(con->rx_page);
+ nvec = 2;
+ }
+ len = iov[0].iov_len + iov[1].iov_len;
+
+ r = ret = kernel_recvmsg(con->sock, &msg, iov, nvec, len,
+ MSG_DONTWAIT | MSG_NOSIGNAL);
+
+ if (ret <= 0)
+ goto out_close;
+ if (ret == -EAGAIN)
+ goto out_resched;
+
+ if (ret == len)
+ call_again_soon = 1;
+ cbuf_add(&con->cb, ret);
+ ret = dlm_process_incoming_buffer(con->nodeid,
+ page_address(con->rx_page),
+ con->cb.base, con->cb.len,
+ PAGE_CACHE_SIZE);
+ if (ret == -EBADMSG) {
+ printk(KERN_INFO "dlm: lowcomms: addr=%p, base=%u, len=%u, "
+ "iov_len=%u, iov_base[0]=%p, read=%d\n",
+ page_address(con->rx_page), con->cb.base, con->cb.len,
+ len, iov[0].iov_base, r);
+ }
+ if (ret < 0)
+ goto out_close;
+ cbuf_eat(&con->cb, ret);
+
+ if (cbuf_empty(&con->cb) && !call_again_soon) {
+ __free_page(con->rx_page);
+ con->rx_page = NULL;
+ }
+
+ if (call_again_soon)
+ goto out_resched;
+ mutex_unlock(&con->sock_mutex);
+ return 0;
+
+out_resched:
+ 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:
+ 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;
+}
+
+/* Listening socket is busy, accept a connection */
+static int accept_from_sock(struct connection *con)
+{
+ int result;
+ struct sockaddr_storage peeraddr;
+ struct socket *newsock;
+ 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,
+ IPPROTO_TCP, &newsock);
+ if (result < 0)
+ return -ENOMEM;
+
+ mutex_lock_nested(&con->sock_mutex, 0);
+
+ result = -ENOTCONN;
+ if (con->sock == NULL)
+ goto accept_err;
+
+ newsock->type = con->sock->type;
+ newsock->ops = con->sock->ops;
+
+ result = con->sock->ops->accept(con->sock, newsock, O_NONBLOCK);
+ if (result < 0)
+ goto accept_err;
+
+ /* Get the connected socket's peer */
+ memset(&peeraddr, 0, sizeof(peeraddr));
+ if (newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr,
+ &len, 2)) {
+ result = -ECONNABORTED;
+ goto accept_err;
+ }
+
+ /* Get the new node's NODEID */
+ make_sockaddr(&peeraddr, 0, &len);
+ if (dlm_addr_to_nodeid(&peeraddr, &nodeid)) {
+ printk("dlm: connect from non cluster node\n");
+ sock_release(newsock);
+ mutex_unlock(&con->sock_mutex);
+ return -1;
+ }
+
+ log_print("got connection from %d", nodeid);
+
+ /* Check to see if we already have a connection to this node. This
+ * could happen if the two nodes initiate a connection at roughly
+ * the same time and the connections cross on the wire.
+ * TEMPORARY FIX:
+ * In this case we store the incoming one in "othercon"
+ */
+ newcon = nodeid2con(nodeid, GFP_KERNEL);
+ if (!newcon) {
+ result = -ENOMEM;
+ goto accept_err;
+ }
+ mutex_lock_nested(&newcon->sock_mutex, 1);
+ if (newcon->sock) {
+ struct connection *othercon = newcon->othercon;
+
+ if (!othercon) {
+ othercon = kmem_cache_zalloc(con_cache, GFP_KERNEL);
+ if (!othercon) {
+ printk("dlm: failed to allocate incoming socket\n");
+ mutex_unlock(&newcon->sock_mutex);
+ result = -ENOMEM;
+ goto accept_err;
+ }
+ othercon->nodeid = nodeid;
+ othercon->rx_action = receive_from_sock;
+ 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;
+ }
+
+ 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
+ */
+ 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:
+ mutex_unlock(&con->sock_mutex);
+ sock_release(newsock);
+
+ if (result != -EAGAIN)
+ printk("dlm: error accepting connection from node: %d\n", result);
+ return result;
+}
+
+/* Connect a new socket to its peer */
+static void connect_to_sock(struct connection *con)
+{
+ int result = -EHOSTUNREACH;
+ struct sockaddr_storage saddr;
+ int addr_len;
+ struct socket *sock;
+
+ if (con->nodeid == 0) {
+ log_print("attempt to connect sock 0 foiled");
+ return;
+ }
+
+ mutex_lock(&con->sock_mutex);
+ if (con->retries++ > MAX_CONNECT_RETRIES)
+ goto out;
+
+ /* Some odd races can cause double-connects, ignore them */
+ if (con->sock) {
+ result = 0;
+ goto out;
+ }
+
+ /* Create a socket to communicate with */
+ result = sock_create_kern(dlm_local_addr.ss_family, SOCK_STREAM,
+ IPPROTO_TCP, &sock);
+ if (result < 0)
+ goto out_err;
+
+ memset(&saddr, 0, sizeof(saddr));
+ if (dlm_nodeid_to_addr(con->nodeid, &saddr))
+ goto out_err;
+
+ sock->sk->sk_user_data = con;
+ con->rx_action = receive_from_sock;
+
+ make_sockaddr(&saddr, dlm_config.ci_tcp_port, &addr_len);
+
+ add_sock(sock, con);
+
+ log_print("connecting to %d", con->nodeid);
+ result =
+ sock->ops->connect(sock, (struct sockaddr *)&saddr, addr_len,
+ O_NONBLOCK);
+ if (result == -EINPROGRESS)
+ result = 0;
+ if (result == 0)
+ goto out;
+
+out_err:
+ if (con->sock) {
+ sock_release(con->sock);
+ con->sock = NULL;
+ }
+ /*
+ * Some errors are fatal and this list might need adjusting. For other
+ * errors we try again until the max number of retries is reached.
+ */
+ if (result != -EHOSTUNREACH && result != -ENETUNREACH &&
+ result != -ENETDOWN && result != EINVAL
+ && result != -EPROTONOSUPPORT) {
+ lowcomms_connect_sock(con);
+ result = 0;
+ }
+out:
+ mutex_unlock(&con->sock_mutex);
+ return;
+}
+
+static struct socket *create_listen_sock(struct connection *con,
+ struct sockaddr_storage *saddr)
+{
+ struct socket *sock = NULL;
+ mm_segment_t fs;
+ int result = 0;
+ int one = 1;
+ int addr_len;
+
+ if (dlm_local_addr.ss_family == AF_INET)
+ addr_len = sizeof(struct sockaddr_in);
+ else
+ addr_len = sizeof(struct sockaddr_in6);
+
+ /* Create a socket to communicate with */
+ result = sock_create_kern(dlm_local_addr.ss_family, SOCK_STREAM, IPPROTO_TCP, &sock);
+ if (result < 0) {
+ printk("dlm: Can't create listening comms socket\n");
+ goto create_out;
+ }
+
+ fs = get_fs();
+ set_fs(get_ds());
+ result = sock_setsockopt(sock, SOL_SOCKET, SO_REUSEADDR,
+ (char *)&one, sizeof(one));
+ set_fs(fs);
+ if (result < 0) {
+ printk("dlm: Failed to set SO_REUSEADDR on socket: result=%d\n",
+ result);
+ }
+ sock->sk->sk_user_data = con;
+ con->rx_action = accept_from_sock;
+ con->sock = sock;
+
+ /* Bind to our port */
+ 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.ci_tcp_port);
+ sock_release(sock);
+ sock = NULL;
+ con->sock = NULL;
+ goto create_out;
+ }
+
+ fs = get_fs();
+ set_fs(get_ds());
+
+ result = sock_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
+ (char *)&one, sizeof(one));
+ set_fs(fs);
+ if (result < 0) {
+ printk("dlm: Set keepalive failed: %d\n", result);
+ }
+
+ result = sock->ops->listen(sock, 5);
+ if (result < 0) {
+ printk("dlm: Can't listen on port %d\n", dlm_config.ci_tcp_port);
+ sock_release(sock);
+ sock = NULL;
+ goto create_out;
+ }
+
+create_out:
+ return sock;
+}
+
+
+/* Listen on all interfaces */
+static int listen_for_all(void)
+{
+ struct socket *sock = NULL;
+ struct connection *con = nodeid2con(0, GFP_KERNEL);
+ int result = -EINVAL;
+
+ /* We don't support multi-homed hosts */
+ set_bit(CF_IS_OTHERCON, &con->flags);
+
+ sock = create_listen_sock(con, &dlm_local_addr);
+ if (sock) {
+ add_sock(sock, con);
+ result = 0;
+ }
+ else {
+ result = -EADDRINUSE;
+ }
+
+ return result;
+}
+
+
+
+static struct writequeue_entry *new_writequeue_entry(struct connection *con,
+ gfp_t allocation)
+{
+ struct writequeue_entry *entry;
+
+ entry = kmalloc(sizeof(struct writequeue_entry), allocation);
+ if (!entry)
+ return NULL;
+
+ entry->page = alloc_page(allocation);
+ if (!entry->page) {
+ kfree(entry);
+ return NULL;
+ }
+
+ entry->offset = 0;
+ entry->len = 0;
+ entry->end = 0;
+ entry->users = 0;
+ entry->con = con;
+
+ return entry;
+}
+
+void *dlm_lowcomms_get_buffer(int nodeid, int len,
+ gfp_t allocation, char **ppc)
+{
+ struct connection *con;
+ struct writequeue_entry *e;
+ int offset = 0;
+ int users = 0;
+
+ con = nodeid2con(nodeid, allocation);
+ 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)) {
+ e = NULL;
+ } else {
+ offset = e->end;
+ e->end += len;
+ users = e->users++;
+ }
+ spin_unlock(&con->writequeue_lock);
+
+ if (e) {
+ got_one:
+ if (users == 0)
+ kmap(e->page);
+ *ppc = page_address(e->page) + offset;
+ return e;
+ }
+
+ e = new_writequeue_entry(con, allocation);
+ if (e) {
+ spin_lock(&con->writequeue_lock);
+ offset = e->end;
+ e->end += len;
+ users = e->users++;
+ list_add_tail(&e->list, &con->writequeue);
+ spin_unlock(&con->writequeue_lock);
+ goto got_one;
+ }
+ return NULL;
+}
+
+void dlm_lowcomms_commit_buffer(void *mh)
+{
+ struct writequeue_entry *e = (struct writequeue_entry *)mh;
+ struct connection *con = e->con;
+ int users;
+
+ spin_lock(&con->writequeue_lock);
+ users = --e->users;
+ if (users)
+ goto out;
+ e->len = e->end - e->offset;
+ kunmap(e->page);
+ spin_unlock(&con->writequeue_lock);
+
+ if (!test_and_set_bit(CF_WRITE_PENDING, &con->flags)) {
+ queue_work(send_workqueue, &con->swork);
+ }
+ return;
+
+out:
+ spin_unlock(&con->writequeue_lock);
+ return;
+}
+
+static void free_entry(struct writequeue_entry *e)
+{
+ __free_page(e->page);
+ kfree(e);
+}
+
+/* Send a message */
+static void send_to_sock(struct connection *con)
+{
+ int ret = 0;
+ ssize_t(*sendpage) (struct socket *, struct page *, int, size_t, int);
+ const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL;
+ struct writequeue_entry *e;
+ int len, offset;
+
+ mutex_lock(&con->sock_mutex);
+ if (con->sock == NULL)
+ goto out_connect;
+
+ sendpage = con->sock->ops->sendpage;
+
+ spin_lock(&con->writequeue_lock);
+ for (;;) {
+ e = list_entry(con->writequeue.next, struct writequeue_entry,
+ list);
+ if ((struct list_head *) e == &con->writequeue)
+ break;
+
+ len = e->len;
+ offset = e->offset;
+ BUG_ON(len == 0 && e->users == 0);
+ spin_unlock(&con->writequeue_lock);
+ kmap(e->page);
+
+ ret = 0;
+ if (len) {
+ ret = sendpage(con->sock, e->page, offset, len,
+ msg_flags);
+ if (ret == -EAGAIN || ret == 0)
+ goto out;
+ if (ret <= 0)
+ goto send_error;
+ }
+ else {
+ /* Don't starve people filling buffers */
+ cond_resched();
+ }
+
+ spin_lock(&con->writequeue_lock);
+ e->offset += ret;
+ e->len -= ret;
+
+ if (e->len == 0 && e->users == 0) {
+ list_del(&e->list);
+ kunmap(e->page);
+ free_entry(e);
+ continue;
+ }
+ }
+ spin_unlock(&con->writequeue_lock);
+out:
+ mutex_unlock(&con->sock_mutex);
+ return;
+
+send_error:
+ mutex_unlock(&con->sock_mutex);
+ close_connection(con, false);
+ lowcomms_connect_sock(con);
+ return;
+
+out_connect:
+ mutex_unlock(&con->sock_mutex);
+ connect_to_sock(con);
+ return;
+}
+
+static void clean_one_writequeue(struct connection *con)
+{
+ struct list_head *list;
+ struct list_head *temp;
+
+ spin_lock(&con->writequeue_lock);
+ list_for_each_safe(list, temp, &con->writequeue) {
+ struct writequeue_entry *e =
+ list_entry(list, struct writequeue_entry, list);
+ list_del(&e->list);
+ free_entry(e);
+ }
+ spin_unlock(&con->writequeue_lock);
+}
+
+/* Called from recovery when it knows that a node has
+ left the cluster */
+int dlm_lowcomms_close(int nodeid)
+{
+ struct connection *con;
+
+ if (!connections)
+ goto out;
+
+ log_print("closing connection to node %d", nodeid);
+ con = nodeid2con(nodeid, 0);
+ if (con) {
+ clean_one_writequeue(con);
+ close_connection(con, true);
+ }
+ return 0;
+
+out:
+ return -1;
+}
+
+/* Look for activity on active sockets */
+static void process_recv_sockets(struct work_struct *work)
+{
+ struct connection *con = container_of(work, struct connection, rwork);
+ int err;
+
+ clear_bit(CF_READ_PENDING, &con->flags);
+ do {
+ err = con->rx_action(con);
+ } while (!err);
+}
+
+
+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)) {
+ connect_to_sock(con);
+ }
+
+ clear_bit(CF_WRITE_PENDING, &con->flags);
+ send_to_sock(con);
+}
+
+
+/* Discard all entries on the write queues */
+static void clean_writequeues(void)
+{
+ int nodeid;
+
+ for (nodeid = 1; nodeid < conn_array_size; nodeid++) {
+ struct connection *con = nodeid2con(nodeid, 0);
+
+ if (con)
+ clean_one_writequeue(con);
+ }
+}
+
+static void work_stop(void)
+{
+ destroy_workqueue(recv_workqueue);
+ destroy_workqueue(send_workqueue);
+}
+
+static int work_start(void)
+{
+ int error;
+ recv_workqueue = create_workqueue("dlm_recv");
+ error = IS_ERR(recv_workqueue);
+ if (error) {
+ log_print("can't start dlm_recv %d", error);
+ return error;
+ }
+
+ send_workqueue = create_singlethread_workqueue("dlm_send");
+ error = IS_ERR(send_workqueue);
+ if (error) {
+ log_print("can't start dlm_send %d", error);
+ destroy_workqueue(recv_workqueue);
+ return error;
+ }
+
+ return 0;
+}
+
+void dlm_lowcomms_stop(void)
+{
+ int i;
+
+ /* Set all the flags to prevent any
+ socket activity.
+ */
+ for (i = 0; i < conn_array_size; i++) {
+ if (connections[i])
+ connections[i]->flags |= 0xFF;
+ }
+
+ work_stop();
+ clean_writequeues();
+
+ for (i = 0; i < conn_array_size; i++) {
+ if (connections[i]) {
+ close_connection(connections[i], true);
+ if (connections[i]->othercon)
+ kmem_cache_free(con_cache, connections[i]->othercon);
+ kmem_cache_free(con_cache, connections[i]);
+ }
+ }
+
+ kfree(connections);
+ connections = NULL;
+
+ kmem_cache_destroy(con_cache);
+}
+
+/* This is quite likely to sleep... */
+int dlm_lowcomms_start(void)
+{
+ int error = 0;
+
+ error = -ENOMEM;
+ connections = kzalloc(sizeof(struct connection *) *
+ NODE_INCREMENT, GFP_KERNEL);
+ if (!connections)
+ goto out;
+
+ conn_array_size = NODE_INCREMENT;
+
+ if (dlm_our_addr(&dlm_local_addr, 0)) {
+ log_print("no local IP address has been set");
+ goto fail_free_conn;
+ }
+ if (!dlm_our_addr(&dlm_local_addr, 1)) {
+ log_print("This dlm comms module does not support multi-homed clustering");
+ goto fail_free_conn;
+ }
+
+ con_cache = kmem_cache_create("dlm_conn", sizeof(struct connection),
+ __alignof__(struct connection), 0,
+ NULL, NULL);
+ if (!con_cache)
+ goto fail_free_conn;
+
+
+ /* Start listening */
+ error = listen_for_all();
+ if (error)
+ goto fail_unlisten;
+
+ error = work_start();
+ if (error)
+ goto fail_unlisten;
+
+ return 0;
+
+fail_unlisten:
+ close_connection(connections[0], false);
+ kmem_cache_free(con_cache, connections[0]);
+ kmem_cache_destroy(con_cache);
+
+fail_free_conn:
+ kfree(connections);
+
+out:
+ return error;
+}
+
+/*
+ * Overrides for Emacs so that we follow Linus's tabbing style.
+ * Emacs will notice this stuff at the end of the file and automatically
+ * adjust the settings for this buffer only. This must remain at the end
+ * of the file.
+ * ---------------------------------------------------------------------------
+ * Local variables:
+ * c-file-style: "linux"
+ * End:
+ */
git://git.onelab.eu / linux-2.6.git / blobdiff