A general purpose distributed lock manager for kernel or userspace
applications.
+choice
+ prompt "Select DLM communications protocol"
+ depends on DLM
+ default DLM_TCP
+ help
+ The DLM Can use TCP or SCTP for it's network communications.
+ SCTP supports multi-homed operations whereas TCP doesn't.
+ However, SCTP seems to have stability problems at the moment.
+
+config DLM_TCP
+ bool "TCP/IP"
+
+config DLM_SCTP
+ bool "SCTP"
+
+endchoice
+
config DLM_DEBUG
bool "DLM debugging"
depends on DLM
dir.o \
lock.o \
lockspace.o \
- lowcomms.o \
main.o \
member.o \
memory.o \
util.o
dlm-$(CONFIG_DLM_DEBUG) += debug_fs.o
+dlm-$(CONFIG_DLM_TCP) += lowcomms-tcp.o
+
+dlm-$(CONFIG_DLM_SCTP) += lowcomms-sctp.o
\ No newline at end of file
--- /dev/null
+/******************************************************************************
+*******************************************************************************
+**
+** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
+** Copyright (C) 2004-2005 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 (well, hardly ever) waits.
+ *
+ */
+
+#include <asm/ioctls.h>
+#include <net/sock.h>
+#include <net/tcp.h>
+#include <net/sctp/user.h>
+#include <linux/pagemap.h>
+#include <linux/socket.h>
+#include <linux/idr.h>
+
+#include "dlm_internal.h"
+#include "lowcomms.h"
+#include "config.h"
+#include "midcomms.h"
+
+static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT];
+static int dlm_local_count;
+static int dlm_local_nodeid;
+
+/* One of these per connected node */
+
+#define NI_INIT_PENDING 1
+#define NI_WRITE_PENDING 2
+
+struct nodeinfo {
+ spinlock_t lock;
+ sctp_assoc_t assoc_id;
+ unsigned long flags;
+ struct list_head write_list; /* nodes with pending writes */
+ struct list_head writequeue; /* outgoing writequeue_entries */
+ spinlock_t writequeue_lock;
+ int nodeid;
+};
+
+static DEFINE_IDR(nodeinfo_idr);
+static struct rw_semaphore nodeinfo_lock;
+static int max_nodeid;
+
+struct cbuf {
+ unsigned base;
+ unsigned len;
+ unsigned mask;
+};
+
+/* Just the one of these, now. But this struct keeps
+ the connection-specific variables together */
+
+#define CF_READ_PENDING 1
+
+struct connection {
+ struct socket *sock;
+ unsigned long flags;
+ struct page *rx_page;
+ atomic_t waiting_requests;
+ struct cbuf cb;
+ int eagain_flag;
+};
+
+/* 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 nodeinfo *ni;
+};
+
+#define CBUF_ADD(cb, n) do { (cb)->len += n; } while(0)
+#define CBUF_EMPTY(cb) ((cb)->len == 0)
+#define CBUF_MAY_ADD(cb, n) (((cb)->len + (n)) < ((cb)->mask + 1))
+#define CBUF_DATA(cb) (((cb)->base + (cb)->len) & (cb)->mask)
+
+#define CBUF_INIT(cb, size) \
+do { \
+ (cb)->base = (cb)->len = 0; \
+ (cb)->mask = ((size)-1); \
+} while(0)
+
+#define CBUF_EAT(cb, n) \
+do { \
+ (cb)->len -= (n); \
+ (cb)->base += (n); \
+ (cb)->base &= (cb)->mask; \
+} while(0)
+
+
+/* List of nodes which have writes pending */
+static struct list_head write_nodes;
+static spinlock_t write_nodes_lock;
+
+/* Maximum number of incoming messages to process before
+ * doing a schedule()
+ */
+#define MAX_RX_MSG_COUNT 25
+
+/* Manage daemons */
+static struct task_struct *recv_task;
+static struct task_struct *send_task;
+static wait_queue_head_t lowcomms_recv_wait;
+static atomic_t accepting;
+
+/* The SCTP connection */
+static struct connection sctp_con;
+
+
+static int nodeid_to_addr(int nodeid, struct sockaddr *retaddr)
+{
+ struct sockaddr_storage addr;
+ int error;
+
+ if (!dlm_local_count)
+ return -1;
+
+ error = dlm_nodeid_to_addr(nodeid, &addr);
+ if (error)
+ return error;
+
+ if (dlm_local_addr[0]->ss_family == AF_INET) {
+ struct sockaddr_in *in4 = (struct sockaddr_in *) &addr;
+ struct sockaddr_in *ret4 = (struct sockaddr_in *) retaddr;
+ ret4->sin_addr.s_addr = in4->sin_addr.s_addr;
+ } else {
+ struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &addr;
+ struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) retaddr;
+ memcpy(&ret6->sin6_addr, &in6->sin6_addr,
+ sizeof(in6->sin6_addr));
+ }
+
+ return 0;
+}
+
+static struct nodeinfo *nodeid2nodeinfo(int nodeid, gfp_t alloc)
+{
+ struct nodeinfo *ni;
+ int r;
+ int n;
+
+ down_read(&nodeinfo_lock);
+ ni = idr_find(&nodeinfo_idr, nodeid);
+ up_read(&nodeinfo_lock);
+
+ if (!ni && alloc) {
+ down_write(&nodeinfo_lock);
+
+ ni = idr_find(&nodeinfo_idr, nodeid);
+ if (ni)
+ goto out_up;
+
+ r = idr_pre_get(&nodeinfo_idr, alloc);
+ if (!r)
+ goto out_up;
+
+ ni = kmalloc(sizeof(struct nodeinfo), alloc);
+ if (!ni)
+ goto out_up;
+
+ r = idr_get_new_above(&nodeinfo_idr, ni, nodeid, &n);
+ if (r) {
+ kfree(ni);
+ ni = NULL;
+ goto out_up;
+ }
+ if (n != nodeid) {
+ idr_remove(&nodeinfo_idr, n);
+ kfree(ni);
+ ni = NULL;
+ goto out_up;
+ }
+ memset(ni, 0, sizeof(struct nodeinfo));
+ spin_lock_init(&ni->lock);
+ INIT_LIST_HEAD(&ni->writequeue);
+ spin_lock_init(&ni->writequeue_lock);
+ ni->nodeid = nodeid;
+
+ if (nodeid > max_nodeid)
+ max_nodeid = nodeid;
+ out_up:
+ up_write(&nodeinfo_lock);
+ }
+
+ return ni;
+}
+
+/* Don't call this too often... */
+static struct nodeinfo *assoc2nodeinfo(sctp_assoc_t assoc)
+{
+ int i;
+ struct nodeinfo *ni;
+
+ for (i=1; i<=max_nodeid; i++) {
+ ni = nodeid2nodeinfo(i, 0);
+ if (ni && ni->assoc_id == assoc)
+ return ni;
+ }
+ return NULL;
+}
+
+/* Data or notification available on socket */
+static void lowcomms_data_ready(struct sock *sk, int count_unused)
+{
+ atomic_inc(&sctp_con.waiting_requests);
+ if (test_and_set_bit(CF_READ_PENDING, &sctp_con.flags))
+ return;
+
+ wake_up_interruptible(&lowcomms_recv_wait);
+}
+
+
+/* Add the port number to an IP6 or 4 sockaddr and return the address length.
+ Also padd out the struct with zeros to make comparisons meaningful */
+
+static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
+ int *addr_len)
+{
+ struct sockaddr_in *local4_addr;
+ struct sockaddr_in6 *local6_addr;
+
+ if (!dlm_local_count)
+ return;
+
+ if (!port) {
+ if (dlm_local_addr[0]->ss_family == AF_INET) {
+ local4_addr = (struct sockaddr_in *)dlm_local_addr[0];
+ port = be16_to_cpu(local4_addr->sin_port);
+ } else {
+ local6_addr = (struct sockaddr_in6 *)dlm_local_addr[0];
+ port = be16_to_cpu(local6_addr->sin6_port);
+ }
+ }
+
+ saddr->ss_family = dlm_local_addr[0]->ss_family;
+ if (dlm_local_addr[0]->ss_family == AF_INET) {
+ struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr;
+ in4_addr->sin_port = cpu_to_be16(port);
+ memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero));
+ memset(in4_addr+1, 0, sizeof(struct sockaddr_storage) -
+ sizeof(struct sockaddr_in));
+ *addr_len = sizeof(struct sockaddr_in);
+ } else {
+ struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr;
+ in6_addr->sin6_port = cpu_to_be16(port);
+ memset(in6_addr+1, 0, sizeof(struct sockaddr_storage) -
+ sizeof(struct sockaddr_in6));
+ *addr_len = sizeof(struct sockaddr_in6);
+ }
+}
+
+/* Close the connection and tidy up */
+static void close_connection(void)
+{
+ if (sctp_con.sock) {
+ sock_release(sctp_con.sock);
+ sctp_con.sock = NULL;
+ }
+
+ if (sctp_con.rx_page) {
+ __free_page(sctp_con.rx_page);
+ sctp_con.rx_page = NULL;
+ }
+}
+
+/* We only send shutdown messages to nodes that are not part of the cluster */
+static void send_shutdown(sctp_assoc_t associd)
+{
+ static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
+ struct msghdr outmessage;
+ struct cmsghdr *cmsg;
+ struct sctp_sndrcvinfo *sinfo;
+ int ret;
+
+ outmessage.msg_name = NULL;
+ outmessage.msg_namelen = 0;
+ outmessage.msg_control = outcmsg;
+ outmessage.msg_controllen = sizeof(outcmsg);
+ outmessage.msg_flags = MSG_EOR;
+
+ cmsg = CMSG_FIRSTHDR(&outmessage);
+ cmsg->cmsg_level = IPPROTO_SCTP;
+ cmsg->cmsg_type = SCTP_SNDRCV;
+ cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
+ outmessage.msg_controllen = cmsg->cmsg_len;
+ sinfo = (struct sctp_sndrcvinfo *)CMSG_DATA(cmsg);
+ memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
+
+ sinfo->sinfo_flags |= MSG_EOF;
+ sinfo->sinfo_assoc_id = associd;
+
+ ret = kernel_sendmsg(sctp_con.sock, &outmessage, NULL, 0, 0);
+
+ if (ret != 0)
+ log_print("send EOF to node failed: %d", ret);
+}
+
+
+/* INIT failed but we don't know which node...
+ restart INIT on all pending nodes */
+static void init_failed(void)
+{
+ int i;
+ struct nodeinfo *ni;
+
+ for (i=1; i<=max_nodeid; i++) {
+ ni = nodeid2nodeinfo(i, 0);
+ if (!ni)
+ continue;
+
+ if (test_and_clear_bit(NI_INIT_PENDING, &ni->flags)) {
+ ni->assoc_id = 0;
+ if (!test_and_set_bit(NI_WRITE_PENDING, &ni->flags)) {
+ spin_lock_bh(&write_nodes_lock);
+ list_add_tail(&ni->write_list, &write_nodes);
+ spin_unlock_bh(&write_nodes_lock);
+ }
+ }
+ }
+ wake_up_process(send_task);
+}
+
+/* Something happened to an association */
+static void process_sctp_notification(struct msghdr *msg, char *buf)
+{
+ union sctp_notification *sn = (union sctp_notification *)buf;
+
+ if (sn->sn_header.sn_type == SCTP_ASSOC_CHANGE) {
+ switch (sn->sn_assoc_change.sac_state) {
+
+ case SCTP_COMM_UP:
+ case SCTP_RESTART:
+ {
+ /* Check that the new node is in the lockspace */
+ struct sctp_prim prim;
+ mm_segment_t fs;
+ int nodeid;
+ int prim_len, ret;
+ int addr_len;
+ struct nodeinfo *ni;
+
+ /* This seems to happen when we received a connection
+ * too early... or something... anyway, it happens but
+ * we always seem to get a real message too, see
+ * receive_from_sock */
+
+ if ((int)sn->sn_assoc_change.sac_assoc_id <= 0) {
+ log_print("COMM_UP for invalid assoc ID %d",
+ (int)sn->sn_assoc_change.sac_assoc_id);
+ init_failed();
+ return;
+ }
+ memset(&prim, 0, sizeof(struct sctp_prim));
+ prim_len = sizeof(struct sctp_prim);
+ prim.ssp_assoc_id = sn->sn_assoc_change.sac_assoc_id;
+
+ fs = get_fs();
+ set_fs(get_ds());
+ ret = sctp_con.sock->ops->getsockopt(sctp_con.sock,
+ IPPROTO_SCTP, SCTP_PRIMARY_ADDR,
+ (char*)&prim, &prim_len);
+ set_fs(fs);
+ if (ret < 0) {
+ struct nodeinfo *ni;
+
+ log_print("getsockopt/sctp_primary_addr on "
+ "new assoc %d failed : %d",
+ (int)sn->sn_assoc_change.sac_assoc_id, ret);
+
+ /* Retry INIT later */
+ ni = assoc2nodeinfo(sn->sn_assoc_change.sac_assoc_id);
+ if (ni)
+ clear_bit(NI_INIT_PENDING, &ni->flags);
+ return;
+ }
+ make_sockaddr(&prim.ssp_addr, 0, &addr_len);
+ if (dlm_addr_to_nodeid(&prim.ssp_addr, &nodeid)) {
+ log_print("reject connect from unknown addr");
+ send_shutdown(prim.ssp_assoc_id);
+ return;
+ }
+
+ ni = nodeid2nodeinfo(nodeid, GFP_KERNEL);
+ if (!ni)
+ return;
+
+ /* Save the assoc ID */
+ spin_lock(&ni->lock);
+ ni->assoc_id = sn->sn_assoc_change.sac_assoc_id;
+ spin_unlock(&ni->lock);
+
+ log_print("got new/restarted association %d nodeid %d",
+ (int)sn->sn_assoc_change.sac_assoc_id, nodeid);
+
+ /* Send any pending writes */
+ clear_bit(NI_INIT_PENDING, &ni->flags);
+ if (!test_and_set_bit(NI_WRITE_PENDING, &ni->flags)) {
+ spin_lock_bh(&write_nodes_lock);
+ list_add_tail(&ni->write_list, &write_nodes);
+ spin_unlock_bh(&write_nodes_lock);
+ }
+ wake_up_process(send_task);
+ }
+ break;
+
+ case SCTP_COMM_LOST:
+ case SCTP_SHUTDOWN_COMP:
+ {
+ struct nodeinfo *ni;
+
+ ni = assoc2nodeinfo(sn->sn_assoc_change.sac_assoc_id);
+ if (ni) {
+ spin_lock(&ni->lock);
+ ni->assoc_id = 0;
+ spin_unlock(&ni->lock);
+ }
+ }
+ break;
+
+ /* We don't know which INIT failed, so clear the PENDING flags
+ * on them all. if assoc_id is zero then it will then try
+ * again */
+
+ case SCTP_CANT_STR_ASSOC:
+ {
+ log_print("Can't start SCTP association - retrying");
+ init_failed();
+ }
+ break;
+
+ default:
+ log_print("unexpected SCTP assoc change id=%d state=%d",
+ (int)sn->sn_assoc_change.sac_assoc_id,
+ sn->sn_assoc_change.sac_state);
+ }
+ }
+}
+
+/* Data received from remote end */
+static int receive_from_sock(void)
+{
+ int ret = 0;
+ struct msghdr msg;
+ struct kvec iov[2];
+ unsigned len;
+ int r;
+ struct sctp_sndrcvinfo *sinfo;
+ struct cmsghdr *cmsg;
+ struct nodeinfo *ni;
+
+ /* These two are marginally too big for stack allocation, but this
+ * function is (currently) only called by dlm_recvd so static should be
+ * OK.
+ */
+ static struct sockaddr_storage msgname;
+ static char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
+
+ if (sctp_con.sock == NULL)
+ goto out;
+
+ if (sctp_con.rx_page == NULL) {
+ /*
+ * This doesn't need to be atomic, but I think it should
+ * improve performance if it is.
+ */
+ sctp_con.rx_page = alloc_page(GFP_ATOMIC);
+ if (sctp_con.rx_page == NULL)
+ goto out_resched;
+ CBUF_INIT(&sctp_con.cb, PAGE_CACHE_SIZE);
+ }
+
+ memset(&incmsg, 0, sizeof(incmsg));
+ memset(&msgname, 0, sizeof(msgname));
+
+ memset(incmsg, 0, sizeof(incmsg));
+ msg.msg_name = &msgname;
+ msg.msg_namelen = sizeof(msgname);
+ msg.msg_flags = 0;
+ msg.msg_control = incmsg;
+ msg.msg_controllen = sizeof(incmsg);
+ msg.msg_iovlen = 1;
+
+ /* I don't see why this circular buffer stuff is necessary for SCTP
+ * which is a packet-based protocol, but the whole thing breaks under
+ * load without it! The overhead is minimal (and is in the TCP lowcomms
+ * anyway, of course) so I'll leave it in until I can figure out what's
+ * really happening.
+ */
+
+ /*
+ * 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 = sctp_con.cb.base - CBUF_DATA(&sctp_con.cb);
+ iov[0].iov_base = page_address(sctp_con.rx_page) +
+ CBUF_DATA(&sctp_con.cb);
+ iov[1].iov_len = 0;
+
+ /*
+ * 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(&sctp_con.cb) >= sctp_con.cb.base) {
+ iov[0].iov_len = PAGE_CACHE_SIZE - CBUF_DATA(&sctp_con.cb);
+ iov[1].iov_len = sctp_con.cb.base;
+ iov[1].iov_base = page_address(sctp_con.rx_page);
+ msg.msg_iovlen = 2;
+ }
+ len = iov[0].iov_len + iov[1].iov_len;
+
+ r = ret = kernel_recvmsg(sctp_con.sock, &msg, iov, msg.msg_iovlen, len,
+ MSG_NOSIGNAL | MSG_DONTWAIT);
+ if (ret <= 0)
+ goto out_close;
+
+ msg.msg_control = incmsg;
+ msg.msg_controllen = sizeof(incmsg);
+ cmsg = CMSG_FIRSTHDR(&msg);
+ sinfo = (struct sctp_sndrcvinfo *)CMSG_DATA(cmsg);
+
+ if (msg.msg_flags & MSG_NOTIFICATION) {
+ process_sctp_notification(&msg, page_address(sctp_con.rx_page));
+ return 0;
+ }
+
+ /* Is this a new association ? */
+ ni = nodeid2nodeinfo(le32_to_cpu(sinfo->sinfo_ppid), GFP_KERNEL);
+ if (ni) {
+ ni->assoc_id = sinfo->sinfo_assoc_id;
+ if (test_and_clear_bit(NI_INIT_PENDING, &ni->flags)) {
+
+ if (!test_and_set_bit(NI_WRITE_PENDING, &ni->flags)) {
+ spin_lock_bh(&write_nodes_lock);
+ list_add_tail(&ni->write_list, &write_nodes);
+ spin_unlock_bh(&write_nodes_lock);
+ }
+ wake_up_process(send_task);
+ }
+ }
+
+ /* INIT sends a message with length of 1 - ignore it */
+ if (r == 1)
+ return 0;
+
+ CBUF_ADD(&sctp_con.cb, ret);
+ ret = dlm_process_incoming_buffer(cpu_to_le32(sinfo->sinfo_ppid),
+ page_address(sctp_con.rx_page),
+ sctp_con.cb.base, sctp_con.cb.len,
+ PAGE_CACHE_SIZE);
+ if (ret < 0)
+ goto out_close;
+ CBUF_EAT(&sctp_con.cb, ret);
+
+ out:
+ ret = 0;
+ goto out_ret;
+
+ out_resched:
+ lowcomms_data_ready(sctp_con.sock->sk, 0);
+ ret = 0;
+ schedule();
+ goto out_ret;
+
+ out_close:
+ if (ret != -EAGAIN)
+ log_print("error reading from sctp socket: %d", ret);
+ out_ret:
+ return ret;
+}
+
+/* Bind to an IP address. SCTP allows multiple address so it can do multi-homing */
+static int add_bind_addr(struct sockaddr_storage *addr, int addr_len, int num)
+{
+ mm_segment_t fs;
+ int result = 0;
+
+ fs = get_fs();
+ set_fs(get_ds());
+ if (num == 1)
+ result = sctp_con.sock->ops->bind(sctp_con.sock,
+ (struct sockaddr *) addr, addr_len);
+ else
+ result = sctp_con.sock->ops->setsockopt(sctp_con.sock, SOL_SCTP,
+ SCTP_SOCKOPT_BINDX_ADD, (char *)addr, addr_len);
+ set_fs(fs);
+
+ if (result < 0)
+ log_print("Can't bind to port %d addr number %d",
+ dlm_config.tcp_port, num);
+
+ return result;
+}
+
+static void init_local(void)
+{
+ struct sockaddr_storage sas, *addr;
+ int i;
+
+ dlm_local_nodeid = dlm_our_nodeid();
+
+ for (i = 0; i < DLM_MAX_ADDR_COUNT - 1; i++) {
+ if (dlm_our_addr(&sas, i))
+ break;
+
+ addr = kmalloc(sizeof(*addr), GFP_KERNEL);
+ if (!addr)
+ break;
+ memcpy(addr, &sas, sizeof(*addr));
+ dlm_local_addr[dlm_local_count++] = addr;
+ }
+}
+
+/* Initialise SCTP socket and bind to all interfaces */
+static int init_sock(void)
+{
+ mm_segment_t fs;
+ struct socket *sock = NULL;
+ struct sockaddr_storage localaddr;
+ struct sctp_event_subscribe subscribe;
+ int result = -EINVAL, num = 1, i, addr_len;
+
+ if (!dlm_local_count) {
+ init_local();
+ if (!dlm_local_count) {
+ log_print("no local IP address has been set");
+ goto out;
+ }
+ }
+
+ result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_SEQPACKET,
+ IPPROTO_SCTP, &sock);
+ if (result < 0) {
+ log_print("Can't create comms socket, check SCTP is loaded");
+ goto out;
+ }
+
+ /* Listen for events */
+ memset(&subscribe, 0, sizeof(subscribe));
+ subscribe.sctp_data_io_event = 1;
+ subscribe.sctp_association_event = 1;
+ subscribe.sctp_send_failure_event = 1;
+ subscribe.sctp_shutdown_event = 1;
+ subscribe.sctp_partial_delivery_event = 1;
+
+ fs = get_fs();
+ set_fs(get_ds());
+ result = sock->ops->setsockopt(sock, SOL_SCTP, SCTP_EVENTS,
+ (char *)&subscribe, sizeof(subscribe));
+ set_fs(fs);
+
+ if (result < 0) {
+ log_print("Failed to set SCTP_EVENTS on socket: result=%d",
+ result);
+ goto create_delsock;
+ }
+
+ /* Init con struct */
+ sock->sk->sk_user_data = &sctp_con;
+ sctp_con.sock = sock;
+ sctp_con.sock->sk->sk_data_ready = lowcomms_data_ready;
+
+ /* Bind to all interfaces. */
+ for (i = 0; i < dlm_local_count; i++) {
+ memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr));
+ make_sockaddr(&localaddr, dlm_config.tcp_port, &addr_len);
+
+ result = add_bind_addr(&localaddr, addr_len, num);
+ if (result)
+ goto create_delsock;
+ ++num;
+ }
+
+ result = sock->ops->listen(sock, 5);
+ if (result < 0) {
+ log_print("Can't set socket listening");
+ goto create_delsock;
+ }
+
+ return 0;
+
+ create_delsock:
+ sock_release(sock);
+ sctp_con.sock = NULL;
+ out:
+ return result;
+}
+
+
+static struct writequeue_entry *new_writequeue_entry(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;
+
+ return entry;
+}
+
+void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc)
+{
+ struct writequeue_entry *e;
+ int offset = 0;
+ int users = 0;
+ struct nodeinfo *ni;
+
+ if (!atomic_read(&accepting))
+ return NULL;
+
+ ni = nodeid2nodeinfo(nodeid, allocation);
+ if (!ni)
+ return NULL;
+
+ spin_lock(&ni->writequeue_lock);
+ e = list_entry(ni->writequeue.prev, struct writequeue_entry, list);
+ if (((struct list_head *) e == &ni->writequeue) ||
+ (PAGE_CACHE_SIZE - e->end < len)) {
+ e = NULL;
+ } else {
+ offset = e->end;
+ e->end += len;
+ users = e->users++;
+ }
+ spin_unlock(&ni->writequeue_lock);
+
+ if (e) {
+ got_one:
+ if (users == 0)
+ kmap(e->page);
+ *ppc = page_address(e->page) + offset;
+ return e;
+ }
+
+ e = new_writequeue_entry(allocation);
+ if (e) {
+ spin_lock(&ni->writequeue_lock);
+ offset = e->end;
+ e->end += len;
+ e->ni = ni;
+ users = e->users++;
+ list_add_tail(&e->list, &ni->writequeue);
+ spin_unlock(&ni->writequeue_lock);
+ goto got_one;
+ }
+ return NULL;
+}
+
+void dlm_lowcomms_commit_buffer(void *arg)
+{
+ struct writequeue_entry *e = (struct writequeue_entry *) arg;
+ int users;
+ struct nodeinfo *ni = e->ni;
+
+ if (!atomic_read(&accepting))
+ return;
+
+ spin_lock(&ni->writequeue_lock);
+ users = --e->users;
+ if (users)
+ goto out;
+ e->len = e->end - e->offset;
+ kunmap(e->page);
+ spin_unlock(&ni->writequeue_lock);
+
+ if (!test_and_set_bit(NI_WRITE_PENDING, &ni->flags)) {
+ spin_lock_bh(&write_nodes_lock);
+ list_add_tail(&ni->write_list, &write_nodes);
+ spin_unlock_bh(&write_nodes_lock);
+ wake_up_process(send_task);
+ }
+ return;
+
+ out:
+ spin_unlock(&ni->writequeue_lock);
+ return;
+}
+
+static void free_entry(struct writequeue_entry *e)
+{
+ __free_page(e->page);
+ kfree(e);
+}
+
+/* Initiate an SCTP association. In theory we could just use sendmsg() on
+ the first IP address and it should work, but this allows us to set up the
+ association before sending any valuable data that we can't afford to lose.
+ It also keeps the send path clean as it can now always use the association ID */
+static void initiate_association(int nodeid)
+{
+ struct sockaddr_storage rem_addr;
+ static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
+ struct msghdr outmessage;
+ struct cmsghdr *cmsg;
+ struct sctp_sndrcvinfo *sinfo;
+ int ret;
+ int addrlen;
+ char buf[1];
+ struct kvec iov[1];
+ struct nodeinfo *ni;
+
+ log_print("Initiating association with node %d", nodeid);
+
+ ni = nodeid2nodeinfo(nodeid, GFP_KERNEL);
+ if (!ni)
+ return;
+
+ if (nodeid_to_addr(nodeid, (struct sockaddr *)&rem_addr)) {
+ log_print("no address for nodeid %d", nodeid);
+ return;
+ }
+
+ make_sockaddr(&rem_addr, dlm_config.tcp_port, &addrlen);
+
+ outmessage.msg_name = &rem_addr;
+ outmessage.msg_namelen = addrlen;
+ outmessage.msg_control = outcmsg;
+ outmessage.msg_controllen = sizeof(outcmsg);
+ outmessage.msg_flags = MSG_EOR;
+
+ iov[0].iov_base = buf;
+ iov[0].iov_len = 1;
+
+ /* Real INIT messages seem to cause trouble. Just send a 1 byte message
+ we can afford to lose */
+ cmsg = CMSG_FIRSTHDR(&outmessage);
+ cmsg->cmsg_level = IPPROTO_SCTP;
+ cmsg->cmsg_type = SCTP_SNDRCV;
+ cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
+ sinfo = (struct sctp_sndrcvinfo *)CMSG_DATA(cmsg);
+ memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
+ sinfo->sinfo_ppid = cpu_to_le32(dlm_local_nodeid);
+
+ outmessage.msg_controllen = cmsg->cmsg_len;
+ ret = kernel_sendmsg(sctp_con.sock, &outmessage, iov, 1, 1);
+ if (ret < 0) {
+ log_print("send INIT to node failed: %d", ret);
+ /* Try again later */
+ clear_bit(NI_INIT_PENDING, &ni->flags);
+ }
+}
+
+/* Send a message */
+static int send_to_sock(struct nodeinfo *ni)
+{
+ int ret = 0;
+ struct writequeue_entry *e;
+ int len, offset;
+ struct msghdr outmsg;
+ static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
+ struct cmsghdr *cmsg;
+ struct sctp_sndrcvinfo *sinfo;
+ struct kvec iov;
+
+ /* See if we need to init an association before we start
+ sending precious messages */
+ spin_lock(&ni->lock);
+ if (!ni->assoc_id && !test_and_set_bit(NI_INIT_PENDING, &ni->flags)) {
+ spin_unlock(&ni->lock);
+ initiate_association(ni->nodeid);
+ return 0;
+ }
+ spin_unlock(&ni->lock);
+
+ outmsg.msg_name = NULL; /* We use assoc_id */
+ outmsg.msg_namelen = 0;
+ outmsg.msg_control = outcmsg;
+ outmsg.msg_controllen = sizeof(outcmsg);
+ outmsg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL | MSG_EOR;
+
+ cmsg = CMSG_FIRSTHDR(&outmsg);
+ cmsg->cmsg_level = IPPROTO_SCTP;
+ cmsg->cmsg_type = SCTP_SNDRCV;
+ cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
+ sinfo = (struct sctp_sndrcvinfo *)CMSG_DATA(cmsg);
+ memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
+ sinfo->sinfo_ppid = cpu_to_le32(dlm_local_nodeid);
+ sinfo->sinfo_assoc_id = ni->assoc_id;
+ outmsg.msg_controllen = cmsg->cmsg_len;
+
+ spin_lock(&ni->writequeue_lock);
+ for (;;) {
+ if (list_empty(&ni->writequeue))
+ break;
+ e = list_entry(ni->writequeue.next, struct writequeue_entry,
+ list);
+ len = e->len;
+ offset = e->offset;
+ BUG_ON(len == 0 && e->users == 0);
+ spin_unlock(&ni->writequeue_lock);
+ kmap(e->page);
+
+ ret = 0;
+ if (len) {
+ iov.iov_base = page_address(e->page)+offset;
+ iov.iov_len = len;
+
+ ret = kernel_sendmsg(sctp_con.sock, &outmsg, &iov, 1,
+ len);
+ if (ret == -EAGAIN) {
+ sctp_con.eagain_flag = 1;
+ goto out;
+ } else if (ret < 0)
+ goto send_error;
+ } else {
+ /* Don't starve people filling buffers */
+ schedule();
+ }
+
+ spin_lock(&ni->writequeue_lock);
+ e->offset += ret;
+ e->len -= ret;
+
+ if (e->len == 0 && e->users == 0) {
+ list_del(&e->list);
+ free_entry(e);
+ continue;
+ }
+ }
+ spin_unlock(&ni->writequeue_lock);
+ out:
+ return ret;
+
+ send_error:
+ log_print("Error sending to node %d %d", ni->nodeid, ret);
+ spin_lock(&ni->lock);
+ if (!test_and_set_bit(NI_INIT_PENDING, &ni->flags)) {
+ ni->assoc_id = 0;
+ spin_unlock(&ni->lock);
+ initiate_association(ni->nodeid);
+ } else
+ spin_unlock(&ni->lock);
+
+ return ret;
+}
+
+/* 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_nodes_lock);
+ list_for_each_safe(list, temp, &write_nodes) {
+ struct nodeinfo *ni =
+ list_entry(list, struct nodeinfo, write_list);
+ clear_bit(NI_WRITE_PENDING, &ni->flags);
+ list_del(&ni->write_list);
+
+ spin_unlock_bh(&write_nodes_lock);
+
+ send_to_sock(ni);
+ spin_lock_bh(&write_nodes_lock);
+ }
+ spin_unlock_bh(&write_nodes_lock);
+}
+
+/* Called after we've had -EAGAIN and been woken up */
+static void refill_write_queue(void)
+{
+ int i;
+
+ for (i=1; i<=max_nodeid; i++) {
+ struct nodeinfo *ni = nodeid2nodeinfo(i, 0);
+
+ if (ni) {
+ if (!test_and_set_bit(NI_WRITE_PENDING, &ni->flags)) {
+ spin_lock_bh(&write_nodes_lock);
+ list_add_tail(&ni->write_list, &write_nodes);
+ spin_unlock_bh(&write_nodes_lock);
+ }
+ }
+ }
+}
+
+static void clean_one_writequeue(struct nodeinfo *ni)
+{
+ struct list_head *list;
+ struct list_head *temp;
+
+ spin_lock(&ni->writequeue_lock);
+ list_for_each_safe(list, temp, &ni->writequeue) {
+ struct writequeue_entry *e =
+ list_entry(list, struct writequeue_entry, list);
+ list_del(&e->list);
+ free_entry(e);
+ }
+ spin_unlock(&ni->writequeue_lock);
+}
+
+static void clean_writequeues(void)
+{
+ int i;
+
+ for (i=1; i<=max_nodeid; i++) {
+ struct nodeinfo *ni = nodeid2nodeinfo(i, 0);
+ if (ni)
+ clean_one_writequeue(ni);
+ }
+}
+
+
+static void dealloc_nodeinfo(void)
+{
+ int i;
+
+ for (i=1; i<=max_nodeid; i++) {
+ struct nodeinfo *ni = nodeid2nodeinfo(i, 0);
+ if (ni) {
+ idr_remove(&nodeinfo_idr, i);
+ kfree(ni);
+ }
+ }
+}
+
+int dlm_lowcomms_close(int nodeid)
+{
+ struct nodeinfo *ni;
+
+ ni = nodeid2nodeinfo(nodeid, 0);
+ if (!ni)
+ return -1;
+
+ spin_lock(&ni->lock);
+ if (ni->assoc_id) {
+ ni->assoc_id = 0;
+ /* Don't send shutdown here, sctp will just queue it
+ till the node comes back up! */
+ }
+ spin_unlock(&ni->lock);
+
+ clean_one_writequeue(ni);
+ clear_bit(NI_INIT_PENDING, &ni->flags);
+ return 0;
+}
+
+static int write_list_empty(void)
+{
+ int status;
+
+ spin_lock_bh(&write_nodes_lock);
+ status = list_empty(&write_nodes);
+ spin_unlock_bh(&write_nodes_lock);
+
+ return status;
+}
+
+static int dlm_recvd(void *data)
+{
+ DECLARE_WAITQUEUE(wait, current);
+
+ while (!kthread_should_stop()) {
+ int count = 0;
+
+ set_current_state(TASK_INTERRUPTIBLE);
+ add_wait_queue(&lowcomms_recv_wait, &wait);
+ if (!test_bit(CF_READ_PENDING, &sctp_con.flags))
+ schedule();
+ remove_wait_queue(&lowcomms_recv_wait, &wait);
+ set_current_state(TASK_RUNNING);
+
+ if (test_and_clear_bit(CF_READ_PENDING, &sctp_con.flags)) {
+ int ret;
+
+ do {
+ ret = receive_from_sock();
+
+ /* Don't starve out everyone else */
+ if (++count >= MAX_RX_MSG_COUNT) {
+ schedule();
+ count = 0;
+ }
+ } while (!kthread_should_stop() && ret >=0);
+ }
+ schedule();
+ }
+
+ return 0;
+}
+
+static int dlm_sendd(void *data)
+{
+ DECLARE_WAITQUEUE(wait, current);
+
+ add_wait_queue(sctp_con.sock->sk->sk_sleep, &wait);
+
+ while (!kthread_should_stop()) {
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (write_list_empty())
+ schedule();
+ set_current_state(TASK_RUNNING);
+
+ if (sctp_con.eagain_flag) {
+ sctp_con.eagain_flag = 0;
+ refill_write_queue();
+ }
+ process_output_queue();
+ }
+
+ remove_wait_queue(sctp_con.sock->sk->sk_sleep, &wait);
+
+ 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);
+ if (error) {
+ log_print("can't start dlm_recvd %d", error);
+ return error;
+ }
+ recv_task = p;
+
+ p = kthread_run(dlm_sendd, NULL, "dlm_sendd");
+ error = IS_ERR(p);
+ if (error) {
+ log_print("can't start dlm_sendd %d", error);
+ kthread_stop(recv_task);
+ return error;
+ }
+ send_task = p;
+
+ return 0;
+}
+
+/*
+ * This is quite likely to sleep...
+ */
+int dlm_lowcomms_start(void)
+{
+ int error;
+
+ error = init_sock();
+ if (error)
+ goto fail_sock;
+ error = daemons_start();
+ if (error)
+ goto fail_sock;
+ atomic_set(&accepting, 1);
+ return 0;
+
+ fail_sock:
+ close_connection();
+ return error;
+}
+
+/* Set all the activity flags to prevent any socket activity. */
+
+void dlm_lowcomms_stop(void)
+{
+ atomic_set(&accepting, 0);
+ sctp_con.flags = 0x7;
+ daemons_stop();
+ clean_writequeues();
+ close_connection();
+ dealloc_nodeinfo();
+ max_nodeid = 0;
+}
+
+int dlm_lowcomms_init(void)
+{
+ init_waitqueue_head(&lowcomms_recv_wait);
+ spin_lock_init(&write_nodes_lock);
+ INIT_LIST_HEAD(&write_nodes);
+ init_rwsem(&nodeinfo_lock);
+ return 0;
+}
+
+void dlm_lowcomms_exit(void)
+{
+ int i;
+
+ for (i = 0; i < dlm_local_count; i++)
+ kfree(dlm_local_addr[i]);
+ dlm_local_count = 0;
+ dlm_local_nodeid = 0;
+}
+
--- /dev/null
+/******************************************************************************
+*******************************************************************************
+**
+** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
+** Copyright (C) 2004-2006 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 base;
+ unsigned len;
+ unsigned mask;
+};
+
+#ifndef FALSE
+#define FALSE 0
+#define TRUE 1
+#endif
+#define NODE_INCREMENT 32
+
+#define CBUF_INIT(cb, size) do { (cb)->base = (cb)->len = 0; (cb)->mask = ((size)-1); } while(0)
+#define CBUF_ADD(cb, n) do { (cb)->len += n; } while(0)
+#define CBUF_EMPTY(cb) ((cb)->len == 0)
+#define CBUF_MAY_ADD(cb, n) (((cb)->len + (n)) < ((cb)->mask + 1))
+#define CBUF_EAT(cb, n) do { (cb)->len -= (n); \
+ (cb)->base += (n); (cb)->base &= (cb)->mask; } while(0)
+#define CBUF_DATA(cb) (((cb)->base + (cb)->len) & (cb)->mask)
+
+/* Maximum number of incoming messages to process before
+ doing a schedule()
+*/
+#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 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 */
+ 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;
+ atomic_t waiting_requests;
+#define MAX_CONNECT_RETRIES 3
+ struct connection *othercon;
+};
+#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;
+
+/* Manage daemons */
+static struct task_struct *recv_task;
+static struct task_struct *send_task;
+
+static wait_queue_t lowcomms_send_waitq_head;
+static wait_queue_head_t lowcomms_send_waitq;
+static wait_queue_t lowcomms_recv_waitq_head;
+static wait_queue_head_t lowcomms_recv_waitq;
+
+/* An array of pointers to connections, indexed by NODEID */
+static struct connection **connections;
+static struct semaphore connections_lock;
+static kmem_cache_t *con_cache;
+static int conn_array_size;
+static atomic_t accepting;
+
+/* List of sockets that have reads pending */
+static struct list_head read_sockets;
+static spinlock_t read_sockets_lock;
+
+/* List of sockets which have writes pending */
+static struct list_head write_sockets;
+static spinlock_t write_sockets_lock;
+
+/* List of sockets which have connects pending */
+static struct list_head state_sockets;
+static spinlock_t state_sockets_lock;
+
+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 = kmalloc(sizeof(struct connection *) *
+ new_size, allocation);
+ if (!new_conns)
+ goto finish;
+
+ memset(new_conns, 0, sizeof(struct connection *) * new_size);
+ 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_alloc(con_cache, allocation);
+ if (!con)
+ goto finish;
+
+ memset(con, 0, sizeof(*con));
+ con->nodeid = nodeid;
+ init_rwsem(&con->sock_sem);
+ INIT_LIST_HEAD(&con->writequeue);
+ spin_lock_init(&con->writequeue_lock);
+
+ 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);
+
+ 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);
+}
+
+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);
+}
+
+static inline void lowcomms_connect_sock(struct connection *con)
+{
+ if (test_and_set_bit(CF_CONNECT_PENDING, &con->flags))
+ return;
+ if (!atomic_read(&accepting))
+ 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);
+}
+
+static void lowcomms_state_change(struct sock *sk)
+{
+/* struct connection *con = sock2con(sk); */
+
+ switch (sk->sk_state) {
+ case TCP_ESTABLISHED:
+ lowcomms_write_space(sk);
+ break;
+
+ case TCP_FIN_WAIT1:
+ case TCP_FIN_WAIT2:
+ case TCP_TIME_WAIT:
+ case TCP_CLOSE:
+ case TCP_CLOSE_WAIT:
+ case TCP_LAST_ACK:
+ case TCP_CLOSING:
+ /* FIXME: I think this causes more trouble than it solves.
+ lowcomms wil reconnect anyway when there is something to
+ send. This just attempts reconnection if a node goes down!
+ */
+ /* lowcomms_connect_sock(con); */
+ break;
+
+ default:
+ printk("dlm: lowcomms_state_change: state=%d\n", sk->sk_state);
+ break;
+ }
+}
+
+/* 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, int and_other)
+{
+ down_write(&con->sock_sem);
+
+ if (con->sock) {
+ sock_release(con->sock);
+ con->sock = NULL;
+ }
+ if (con->othercon && and_other) {
+ /* Argh! recursion in kernel code!
+ Actually, this isn't a list so it
+ 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;
+ up_write(&con->sock_sem);
+}
+
+/* Data received from remote end */
+static int receive_from_sock(struct connection *con)
+{
+ int ret = 0;
+ struct msghdr msg;
+ struct iovec iov[2];
+ mm_segment_t fs;
+ unsigned len;
+ int r;
+ int call_again_soon = 0;
+
+ down_read(&con->sock_sem);
+
+ if (con->sock == NULL)
+ goto out;
+ 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);
+ }
+
+ msg.msg_control = NULL;
+ msg.msg_controllen = 0;
+ msg.msg_iovlen = 1;
+ msg.msg_iov = iov;
+ msg.msg_name = NULL;
+ msg.msg_namelen = 0;
+ msg.msg_flags = 0;
+
+ /*
+ * 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);
+ iov[1].iov_len = 0;
+
+ /*
+ * 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);
+ msg.msg_iovlen = 2;
+ }
+ len = iov[0].iov_len + iov[1].iov_len;
+
+ fs = get_fs();
+ set_fs(get_ds());
+ r = ret = sock_recvmsg(con->sock, &msg, len,
+ MSG_DONTWAIT | MSG_NOSIGNAL);
+ set_fs(fs);
+
+ if (ret <= 0)
+ goto out_close;
+ 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;
+ }
+
+ out:
+ if (call_again_soon)
+ goto out_resched;
+ up_read(&con->sock_sem);
+ ret = 0;
+ goto out_ret;
+
+ out_resched:
+ lowcomms_data_ready(con->sock->sk, 0);
+ up_read(&con->sock_sem);
+ ret = 0;
+ schedule();
+ goto out_ret;
+
+ out_close:
+ up_read(&con->sock_sem);
+ if (ret != -EAGAIN && !test_bit(CF_IS_OTHERCON, &con->flags)) {
+ close_connection(con, FALSE);
+ /* Reconnect when there is something to send */
+ }
+
+ out_ret:
+ 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;
+
+ memset(&peeraddr, 0, sizeof(peeraddr));
+ result = sock_create_kern(dlm_local_addr.ss_family, SOCK_STREAM, IPPROTO_TCP, &newsock);
+ if (result < 0)
+ return -ENOMEM;
+
+ down_read(&con->sock_sem);
+
+ 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);
+ up_read(&con->sock_sem);
+ 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;
+ }
+ down_write(&newcon->sock_sem);
+ if (newcon->sock) {
+ struct connection *othercon = newcon->othercon;
+
+ if (!othercon) {
+ othercon = kmem_cache_alloc(con_cache, GFP_KERNEL);
+ if (!othercon) {
+ printk("dlm: failed to allocate incoming socket\n");
+ up_write(&newcon->sock_sem);
+ result = -ENOMEM;
+ goto accept_err;
+ }
+ memset(othercon, 0, sizeof(*othercon));
+ othercon->nodeid = nodeid;
+ othercon->rx_action = receive_from_sock;
+ init_rwsem(&othercon->sock_sem);
+ set_bit(CF_IS_OTHERCON, &othercon->flags);
+ newcon->othercon = othercon;
+ }
+ othercon->sock = newsock;
+ newsock->sk->sk_user_data = othercon;
+ add_sock(newsock, othercon);
+ }
+ else {
+ newsock->sk->sk_user_data = newcon;
+ newcon->rx_action = receive_from_sock;
+ add_sock(newsock, newcon);
+
+ }
+
+ up_write(&newcon->sock_sem);
+
+ /*
+ * 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);
+
+ return 0;
+
+ accept_err:
+ up_read(&con->sock_sem);
+ 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 int 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 0;
+ }
+
+ down_write(&con->sock_sem);
+ 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.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_err;
+
+ out:
+ up_write(&con->sock_sem);
+ /*
+ * Returning an error here means we've given up trying to connect to
+ * a remote node, otherwise we return 0 and reschedule the connetion
+ * attempt
+ */
+ return result;
+
+ 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;
+ }
+ goto out;
+}
+
+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.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);
+ 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.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 */
+ memset(con, 0, sizeof(*con));
+ init_rwsem(&con->sock_sem);
+ spin_lock_init(&con->writequeue_lock);
+ INIT_LIST_HEAD(&con->writequeue);
+ 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;
+
+ if (!atomic_read(&accepting))
+ return NULL;
+
+ con = nodeid2con(nodeid, allocation);
+ if (!con)
+ return NULL;
+
+ spin_lock(&con->writequeue_lock);
+ e = list_entry(con->writequeue.prev, struct writequeue_entry, list);
+ if (((struct list_head *) e == &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;
+
+ if (!atomic_read(&accepting))
+ return;
+
+ 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) == 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);
+ }
+ 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 int 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;
+
+ down_read(&con->sock_sem);
+ 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);
+
+ 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 */
+ schedule();
+ }
+
+ spin_lock(&con->writequeue_lock);
+ e->offset += ret;
+ e->len -= ret;
+
+ if (e->len == 0 && e->users == 0) {
+ list_del(&e->list);
+ free_entry(e);
+ continue;
+ }
+ }
+ spin_unlock(&con->writequeue_lock);
+ out:
+ up_read(&con->sock_sem);
+ return ret;
+
+ send_error:
+ up_read(&con->sock_sem);
+ close_connection(con, FALSE);
+ lowcomms_connect_sock(con);
+ return ret;
+
+ out_connect:
+ up_read(&con->sock_sem);
+ lowcomms_connect_sock(con);
+ return 0;
+}
+
+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);
+ atomic_set(&con->waiting_requests, 0);
+ }
+ return 0;
+
+ 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)
+{
+ 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 =
+ 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) {
+ schedule();
+ 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);
+}
+
+/* Try to send any messages that are pending
+ */
+static void process_output_queue(void)
+{
+ struct list_head *list;
+ struct list_head *temp;
+ int ret;
+
+ 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);
+
+ ret = send_to_sock(con);
+ if (ret < 0) {
+ }
+ spin_lock_bh(&write_sockets_lock);
+ }
+ spin_unlock_bh(&write_sockets_lock);
+}
+
+static void process_state_queue(void)
+{
+ struct list_head *list;
+ struct list_head *temp;
+ int ret;
+
+ 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);
+
+ ret = connect_to_sock(con);
+ if (ret < 0) {
+ }
+ spin_lock_bh(&state_sockets_lock);
+ }
+ spin_unlock_bh(&state_sockets_lock);
+}
+
+
+/* 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 int read_list_empty(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_head(&lowcomms_recv_waitq);
+ 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())
+ schedule();
+ set_current_state(TASK_RUNNING);
+
+ process_sockets();
+ }
+
+ return 0;
+}
+
+static int write_and_state_lists_empty(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_head(&lowcomms_send_waitq);
+ 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())
+ schedule();
+ 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);
+ if (error) {
+ log_print("can't start dlm_recvd %d", error);
+ return error;
+ }
+ recv_task = p;
+
+ p = kthread_run(dlm_sendd, NULL, "dlm_sendd");
+ error = IS_ERR(p);
+ if (error) {
+ log_print("can't start dlm_sendd %d", error);
+ kthread_stop(recv_task);
+ 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;
+
+ atomic_set(&accepting, 0);
+
+ /* Set all the activity flags to prevent any
+ socket activity.
+ */
+ for (i = 0; i < conn_array_size; i++) {
+ if (connections[i])
+ connections[i]->flags |= 0x7;
+ }
+ daemons_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 = -ENOTCONN;
+
+ /*
+ * Temporarily initialise the waitq head so that lowcomms_send_message
+ * doesn't crash if it gets called before the thread is fully
+ * initialised
+ */
+ init_waitqueue_head(&lowcomms_send_waitq);
+
+ error = -ENOMEM;
+ connections = kmalloc(sizeof(struct connection *) *
+ NODE_INCREMENT, GFP_KERNEL);
+ if (!connections)
+ goto out;
+
+ memset(connections, 0,
+ sizeof(struct connection *) * NODE_INCREMENT);
+
+ 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 = daemons_start();
+ if (error)
+ goto fail_unlisten;
+
+ atomic_set(&accepting, 1);
+
+ return 0;
+
+ fail_unlisten:
+ close_connection(connections[0], 0);
+ kmem_cache_free(con_cache, connections[0]);
+ kmem_cache_destroy(con_cache);
+
+ fail_free_conn:
+ kfree(connections);
+
+ out:
+ return error;
+}
+
+int dlm_lowcomms_init(void)
+{
+ INIT_LIST_HEAD(&read_sockets);
+ INIT_LIST_HEAD(&write_sockets);
+ INIT_LIST_HEAD(&state_sockets);
+
+ spin_lock_init(&read_sockets_lock);
+ spin_lock_init(&write_sockets_lock);
+ spin_lock_init(&state_sockets_lock);
+ init_MUTEX(&connections_lock);
+
+ return 0;
+}
+
+void dlm_lowcomms_exit(void)
+{
+}
+
+/*
+ * 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:
+ */
+++ /dev/null
-/******************************************************************************
-*******************************************************************************
-**
-** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
-** Copyright (C) 2004-2005 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 (well, hardly ever) waits.
- *
- */
-
-#include <asm/ioctls.h>
-#include <net/sock.h>
-#include <net/tcp.h>
-#include <net/sctp/user.h>
-#include <linux/pagemap.h>
-#include <linux/socket.h>
-#include <linux/idr.h>
-
-#include "dlm_internal.h"
-#include "lowcomms.h"
-#include "config.h"
-#include "midcomms.h"
-
-static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT];
-static int dlm_local_count;
-static int dlm_local_nodeid;
-
-/* One of these per connected node */
-
-#define NI_INIT_PENDING 1
-#define NI_WRITE_PENDING 2
-
-struct nodeinfo {
- spinlock_t lock;
- sctp_assoc_t assoc_id;
- unsigned long flags;
- struct list_head write_list; /* nodes with pending writes */
- struct list_head writequeue; /* outgoing writequeue_entries */
- spinlock_t writequeue_lock;
- int nodeid;
-};
-
-static DEFINE_IDR(nodeinfo_idr);
-static struct rw_semaphore nodeinfo_lock;
-static int max_nodeid;
-
-struct cbuf {
- unsigned base;
- unsigned len;
- unsigned mask;
-};
-
-/* Just the one of these, now. But this struct keeps
- the connection-specific variables together */
-
-#define CF_READ_PENDING 1
-
-struct connection {
- struct socket *sock;
- unsigned long flags;
- struct page *rx_page;
- atomic_t waiting_requests;
- struct cbuf cb;
- int eagain_flag;
-};
-
-/* 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 nodeinfo *ni;
-};
-
-#define CBUF_ADD(cb, n) do { (cb)->len += n; } while(0)
-#define CBUF_EMPTY(cb) ((cb)->len == 0)
-#define CBUF_MAY_ADD(cb, n) (((cb)->len + (n)) < ((cb)->mask + 1))
-#define CBUF_DATA(cb) (((cb)->base + (cb)->len) & (cb)->mask)
-
-#define CBUF_INIT(cb, size) \
-do { \
- (cb)->base = (cb)->len = 0; \
- (cb)->mask = ((size)-1); \
-} while(0)
-
-#define CBUF_EAT(cb, n) \
-do { \
- (cb)->len -= (n); \
- (cb)->base += (n); \
- (cb)->base &= (cb)->mask; \
-} while(0)
-
-
-/* List of nodes which have writes pending */
-static struct list_head write_nodes;
-static spinlock_t write_nodes_lock;
-
-/* Maximum number of incoming messages to process before
- * doing a schedule()
- */
-#define MAX_RX_MSG_COUNT 25
-
-/* Manage daemons */
-static struct task_struct *recv_task;
-static struct task_struct *send_task;
-static wait_queue_head_t lowcomms_recv_wait;
-static atomic_t accepting;
-
-/* The SCTP connection */
-static struct connection sctp_con;
-
-
-static int nodeid_to_addr(int nodeid, struct sockaddr *retaddr)
-{
- struct sockaddr_storage addr;
- int error;
-
- if (!dlm_local_count)
- return -1;
-
- error = dlm_nodeid_to_addr(nodeid, &addr);
- if (error)
- return error;
-
- if (dlm_local_addr[0]->ss_family == AF_INET) {
- struct sockaddr_in *in4 = (struct sockaddr_in *) &addr;
- struct sockaddr_in *ret4 = (struct sockaddr_in *) retaddr;
- ret4->sin_addr.s_addr = in4->sin_addr.s_addr;
- } else {
- struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &addr;
- struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) retaddr;
- memcpy(&ret6->sin6_addr, &in6->sin6_addr,
- sizeof(in6->sin6_addr));
- }
-
- return 0;
-}
-
-static struct nodeinfo *nodeid2nodeinfo(int nodeid, gfp_t alloc)
-{
- struct nodeinfo *ni;
- int r;
- int n;
-
- down_read(&nodeinfo_lock);
- ni = idr_find(&nodeinfo_idr, nodeid);
- up_read(&nodeinfo_lock);
-
- if (!ni && alloc) {
- down_write(&nodeinfo_lock);
-
- ni = idr_find(&nodeinfo_idr, nodeid);
- if (ni)
- goto out_up;
-
- r = idr_pre_get(&nodeinfo_idr, alloc);
- if (!r)
- goto out_up;
-
- ni = kmalloc(sizeof(struct nodeinfo), alloc);
- if (!ni)
- goto out_up;
-
- r = idr_get_new_above(&nodeinfo_idr, ni, nodeid, &n);
- if (r) {
- kfree(ni);
- ni = NULL;
- goto out_up;
- }
- if (n != nodeid) {
- idr_remove(&nodeinfo_idr, n);
- kfree(ni);
- ni = NULL;
- goto out_up;
- }
- memset(ni, 0, sizeof(struct nodeinfo));
- spin_lock_init(&ni->lock);
- INIT_LIST_HEAD(&ni->writequeue);
- spin_lock_init(&ni->writequeue_lock);
- ni->nodeid = nodeid;
-
- if (nodeid > max_nodeid)
- max_nodeid = nodeid;
- out_up:
- up_write(&nodeinfo_lock);
- }
-
- return ni;
-}
-
-/* Don't call this too often... */
-static struct nodeinfo *assoc2nodeinfo(sctp_assoc_t assoc)
-{
- int i;
- struct nodeinfo *ni;
-
- for (i=1; i<=max_nodeid; i++) {
- ni = nodeid2nodeinfo(i, 0);
- if (ni && ni->assoc_id == assoc)
- return ni;
- }
- return NULL;
-}
-
-/* Data or notification available on socket */
-static void lowcomms_data_ready(struct sock *sk, int count_unused)
-{
- atomic_inc(&sctp_con.waiting_requests);
- if (test_and_set_bit(CF_READ_PENDING, &sctp_con.flags))
- return;
-
- wake_up_interruptible(&lowcomms_recv_wait);
-}
-
-
-/* Add the port number to an IP6 or 4 sockaddr and return the address length.
- Also padd out the struct with zeros to make comparisons meaningful */
-
-static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port,
- int *addr_len)
-{
- struct sockaddr_in *local4_addr;
- struct sockaddr_in6 *local6_addr;
-
- if (!dlm_local_count)
- return;
-
- if (!port) {
- if (dlm_local_addr[0]->ss_family == AF_INET) {
- local4_addr = (struct sockaddr_in *)dlm_local_addr[0];
- port = be16_to_cpu(local4_addr->sin_port);
- } else {
- local6_addr = (struct sockaddr_in6 *)dlm_local_addr[0];
- port = be16_to_cpu(local6_addr->sin6_port);
- }
- }
-
- saddr->ss_family = dlm_local_addr[0]->ss_family;
- if (dlm_local_addr[0]->ss_family == AF_INET) {
- struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr;
- in4_addr->sin_port = cpu_to_be16(port);
- memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero));
- memset(in4_addr+1, 0, sizeof(struct sockaddr_storage) -
- sizeof(struct sockaddr_in));
- *addr_len = sizeof(struct sockaddr_in);
- } else {
- struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr;
- in6_addr->sin6_port = cpu_to_be16(port);
- memset(in6_addr+1, 0, sizeof(struct sockaddr_storage) -
- sizeof(struct sockaddr_in6));
- *addr_len = sizeof(struct sockaddr_in6);
- }
-}
-
-/* Close the connection and tidy up */
-static void close_connection(void)
-{
- if (sctp_con.sock) {
- sock_release(sctp_con.sock);
- sctp_con.sock = NULL;
- }
-
- if (sctp_con.rx_page) {
- __free_page(sctp_con.rx_page);
- sctp_con.rx_page = NULL;
- }
-}
-
-/* We only send shutdown messages to nodes that are not part of the cluster */
-static void send_shutdown(sctp_assoc_t associd)
-{
- static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
- struct msghdr outmessage;
- struct cmsghdr *cmsg;
- struct sctp_sndrcvinfo *sinfo;
- int ret;
-
- outmessage.msg_name = NULL;
- outmessage.msg_namelen = 0;
- outmessage.msg_control = outcmsg;
- outmessage.msg_controllen = sizeof(outcmsg);
- outmessage.msg_flags = MSG_EOR;
-
- cmsg = CMSG_FIRSTHDR(&outmessage);
- cmsg->cmsg_level = IPPROTO_SCTP;
- cmsg->cmsg_type = SCTP_SNDRCV;
- cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
- outmessage.msg_controllen = cmsg->cmsg_len;
- sinfo = (struct sctp_sndrcvinfo *)CMSG_DATA(cmsg);
- memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
-
- sinfo->sinfo_flags |= MSG_EOF;
- sinfo->sinfo_assoc_id = associd;
-
- ret = kernel_sendmsg(sctp_con.sock, &outmessage, NULL, 0, 0);
-
- if (ret != 0)
- log_print("send EOF to node failed: %d", ret);
-}
-
-
-/* INIT failed but we don't know which node...
- restart INIT on all pending nodes */
-static void init_failed(void)
-{
- int i;
- struct nodeinfo *ni;
-
- for (i=1; i<=max_nodeid; i++) {
- ni = nodeid2nodeinfo(i, 0);
- if (!ni)
- continue;
-
- if (test_and_clear_bit(NI_INIT_PENDING, &ni->flags)) {
- ni->assoc_id = 0;
- if (!test_and_set_bit(NI_WRITE_PENDING, &ni->flags)) {
- spin_lock_bh(&write_nodes_lock);
- list_add_tail(&ni->write_list, &write_nodes);
- spin_unlock_bh(&write_nodes_lock);
- }
- }
- }
- wake_up_process(send_task);
-}
-
-/* Something happened to an association */
-static void process_sctp_notification(struct msghdr *msg, char *buf)
-{
- union sctp_notification *sn = (union sctp_notification *)buf;
-
- if (sn->sn_header.sn_type == SCTP_ASSOC_CHANGE) {
- switch (sn->sn_assoc_change.sac_state) {
-
- case SCTP_COMM_UP:
- case SCTP_RESTART:
- {
- /* Check that the new node is in the lockspace */
- struct sctp_prim prim;
- mm_segment_t fs;
- int nodeid;
- int prim_len, ret;
- int addr_len;
- struct nodeinfo *ni;
-
- /* This seems to happen when we received a connection
- * too early... or something... anyway, it happens but
- * we always seem to get a real message too, see
- * receive_from_sock */
-
- if ((int)sn->sn_assoc_change.sac_assoc_id <= 0) {
- log_print("COMM_UP for invalid assoc ID %d",
- (int)sn->sn_assoc_change.sac_assoc_id);
- init_failed();
- return;
- }
- memset(&prim, 0, sizeof(struct sctp_prim));
- prim_len = sizeof(struct sctp_prim);
- prim.ssp_assoc_id = sn->sn_assoc_change.sac_assoc_id;
-
- fs = get_fs();
- set_fs(get_ds());
- ret = sctp_con.sock->ops->getsockopt(sctp_con.sock,
- IPPROTO_SCTP, SCTP_PRIMARY_ADDR,
- (char*)&prim, &prim_len);
- set_fs(fs);
- if (ret < 0) {
- struct nodeinfo *ni;
-
- log_print("getsockopt/sctp_primary_addr on "
- "new assoc %d failed : %d",
- (int)sn->sn_assoc_change.sac_assoc_id, ret);
-
- /* Retry INIT later */
- ni = assoc2nodeinfo(sn->sn_assoc_change.sac_assoc_id);
- if (ni)
- clear_bit(NI_INIT_PENDING, &ni->flags);
- return;
- }
- make_sockaddr(&prim.ssp_addr, 0, &addr_len);
- if (dlm_addr_to_nodeid(&prim.ssp_addr, &nodeid)) {
- log_print("reject connect from unknown addr");
- send_shutdown(prim.ssp_assoc_id);
- return;
- }
-
- ni = nodeid2nodeinfo(nodeid, GFP_KERNEL);
- if (!ni)
- return;
-
- /* Save the assoc ID */
- spin_lock(&ni->lock);
- ni->assoc_id = sn->sn_assoc_change.sac_assoc_id;
- spin_unlock(&ni->lock);
-
- log_print("got new/restarted association %d nodeid %d",
- (int)sn->sn_assoc_change.sac_assoc_id, nodeid);
-
- /* Send any pending writes */
- clear_bit(NI_INIT_PENDING, &ni->flags);
- if (!test_and_set_bit(NI_WRITE_PENDING, &ni->flags)) {
- spin_lock_bh(&write_nodes_lock);
- list_add_tail(&ni->write_list, &write_nodes);
- spin_unlock_bh(&write_nodes_lock);
- }
- wake_up_process(send_task);
- }
- break;
-
- case SCTP_COMM_LOST:
- case SCTP_SHUTDOWN_COMP:
- {
- struct nodeinfo *ni;
-
- ni = assoc2nodeinfo(sn->sn_assoc_change.sac_assoc_id);
- if (ni) {
- spin_lock(&ni->lock);
- ni->assoc_id = 0;
- spin_unlock(&ni->lock);
- }
- }
- break;
-
- /* We don't know which INIT failed, so clear the PENDING flags
- * on them all. if assoc_id is zero then it will then try
- * again */
-
- case SCTP_CANT_STR_ASSOC:
- {
- log_print("Can't start SCTP association - retrying");
- init_failed();
- }
- break;
-
- default:
- log_print("unexpected SCTP assoc change id=%d state=%d",
- (int)sn->sn_assoc_change.sac_assoc_id,
- sn->sn_assoc_change.sac_state);
- }
- }
-}
-
-/* Data received from remote end */
-static int receive_from_sock(void)
-{
- int ret = 0;
- struct msghdr msg;
- struct kvec iov[2];
- unsigned len;
- int r;
- struct sctp_sndrcvinfo *sinfo;
- struct cmsghdr *cmsg;
- struct nodeinfo *ni;
-
- /* These two are marginally too big for stack allocation, but this
- * function is (currently) only called by dlm_recvd so static should be
- * OK.
- */
- static struct sockaddr_storage msgname;
- static char incmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
-
- if (sctp_con.sock == NULL)
- goto out;
-
- if (sctp_con.rx_page == NULL) {
- /*
- * This doesn't need to be atomic, but I think it should
- * improve performance if it is.
- */
- sctp_con.rx_page = alloc_page(GFP_ATOMIC);
- if (sctp_con.rx_page == NULL)
- goto out_resched;
- CBUF_INIT(&sctp_con.cb, PAGE_CACHE_SIZE);
- }
-
- memset(&incmsg, 0, sizeof(incmsg));
- memset(&msgname, 0, sizeof(msgname));
-
- memset(incmsg, 0, sizeof(incmsg));
- msg.msg_name = &msgname;
- msg.msg_namelen = sizeof(msgname);
- msg.msg_flags = 0;
- msg.msg_control = incmsg;
- msg.msg_controllen = sizeof(incmsg);
- msg.msg_iovlen = 1;
-
- /* I don't see why this circular buffer stuff is necessary for SCTP
- * which is a packet-based protocol, but the whole thing breaks under
- * load without it! The overhead is minimal (and is in the TCP lowcomms
- * anyway, of course) so I'll leave it in until I can figure out what's
- * really happening.
- */
-
- /*
- * 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 = sctp_con.cb.base - CBUF_DATA(&sctp_con.cb);
- iov[0].iov_base = page_address(sctp_con.rx_page) +
- CBUF_DATA(&sctp_con.cb);
- iov[1].iov_len = 0;
-
- /*
- * 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(&sctp_con.cb) >= sctp_con.cb.base) {
- iov[0].iov_len = PAGE_CACHE_SIZE - CBUF_DATA(&sctp_con.cb);
- iov[1].iov_len = sctp_con.cb.base;
- iov[1].iov_base = page_address(sctp_con.rx_page);
- msg.msg_iovlen = 2;
- }
- len = iov[0].iov_len + iov[1].iov_len;
-
- r = ret = kernel_recvmsg(sctp_con.sock, &msg, iov, msg.msg_iovlen, len,
- MSG_NOSIGNAL | MSG_DONTWAIT);
- if (ret <= 0)
- goto out_close;
-
- msg.msg_control = incmsg;
- msg.msg_controllen = sizeof(incmsg);
- cmsg = CMSG_FIRSTHDR(&msg);
- sinfo = (struct sctp_sndrcvinfo *)CMSG_DATA(cmsg);
-
- if (msg.msg_flags & MSG_NOTIFICATION) {
- process_sctp_notification(&msg, page_address(sctp_con.rx_page));
- return 0;
- }
-
- /* Is this a new association ? */
- ni = nodeid2nodeinfo(le32_to_cpu(sinfo->sinfo_ppid), GFP_KERNEL);
- if (ni) {
- ni->assoc_id = sinfo->sinfo_assoc_id;
- if (test_and_clear_bit(NI_INIT_PENDING, &ni->flags)) {
-
- if (!test_and_set_bit(NI_WRITE_PENDING, &ni->flags)) {
- spin_lock_bh(&write_nodes_lock);
- list_add_tail(&ni->write_list, &write_nodes);
- spin_unlock_bh(&write_nodes_lock);
- }
- wake_up_process(send_task);
- }
- }
-
- /* INIT sends a message with length of 1 - ignore it */
- if (r == 1)
- return 0;
-
- CBUF_ADD(&sctp_con.cb, ret);
- ret = dlm_process_incoming_buffer(cpu_to_le32(sinfo->sinfo_ppid),
- page_address(sctp_con.rx_page),
- sctp_con.cb.base, sctp_con.cb.len,
- PAGE_CACHE_SIZE);
- if (ret < 0)
- goto out_close;
- CBUF_EAT(&sctp_con.cb, ret);
-
- out:
- ret = 0;
- goto out_ret;
-
- out_resched:
- lowcomms_data_ready(sctp_con.sock->sk, 0);
- ret = 0;
- schedule();
- goto out_ret;
-
- out_close:
- if (ret != -EAGAIN)
- log_print("error reading from sctp socket: %d", ret);
- out_ret:
- return ret;
-}
-
-/* Bind to an IP address. SCTP allows multiple address so it can do multi-homing */
-static int add_bind_addr(struct sockaddr_storage *addr, int addr_len, int num)
-{
- mm_segment_t fs;
- int result = 0;
-
- fs = get_fs();
- set_fs(get_ds());
- if (num == 1)
- result = sctp_con.sock->ops->bind(sctp_con.sock,
- (struct sockaddr *) addr, addr_len);
- else
- result = sctp_con.sock->ops->setsockopt(sctp_con.sock, SOL_SCTP,
- SCTP_SOCKOPT_BINDX_ADD, (char *)addr, addr_len);
- set_fs(fs);
-
- if (result < 0)
- log_print("Can't bind to port %d addr number %d",
- dlm_config.tcp_port, num);
-
- return result;
-}
-
-static void init_local(void)
-{
- struct sockaddr_storage sas, *addr;
- int i;
-
- dlm_local_nodeid = dlm_our_nodeid();
-
- for (i = 0; i < DLM_MAX_ADDR_COUNT - 1; i++) {
- if (dlm_our_addr(&sas, i))
- break;
-
- addr = kmalloc(sizeof(*addr), GFP_KERNEL);
- if (!addr)
- break;
- memcpy(addr, &sas, sizeof(*addr));
- dlm_local_addr[dlm_local_count++] = addr;
- }
-}
-
-/* Initialise SCTP socket and bind to all interfaces */
-static int init_sock(void)
-{
- mm_segment_t fs;
- struct socket *sock = NULL;
- struct sockaddr_storage localaddr;
- struct sctp_event_subscribe subscribe;
- int result = -EINVAL, num = 1, i, addr_len;
-
- if (!dlm_local_count) {
- init_local();
- if (!dlm_local_count) {
- log_print("no local IP address has been set");
- goto out;
- }
- }
-
- result = sock_create_kern(dlm_local_addr[0]->ss_family, SOCK_SEQPACKET,
- IPPROTO_SCTP, &sock);
- if (result < 0) {
- log_print("Can't create comms socket, check SCTP is loaded");
- goto out;
- }
-
- /* Listen for events */
- memset(&subscribe, 0, sizeof(subscribe));
- subscribe.sctp_data_io_event = 1;
- subscribe.sctp_association_event = 1;
- subscribe.sctp_send_failure_event = 1;
- subscribe.sctp_shutdown_event = 1;
- subscribe.sctp_partial_delivery_event = 1;
-
- fs = get_fs();
- set_fs(get_ds());
- result = sock->ops->setsockopt(sock, SOL_SCTP, SCTP_EVENTS,
- (char *)&subscribe, sizeof(subscribe));
- set_fs(fs);
-
- if (result < 0) {
- log_print("Failed to set SCTP_EVENTS on socket: result=%d",
- result);
- goto create_delsock;
- }
-
- /* Init con struct */
- sock->sk->sk_user_data = &sctp_con;
- sctp_con.sock = sock;
- sctp_con.sock->sk->sk_data_ready = lowcomms_data_ready;
-
- /* Bind to all interfaces. */
- for (i = 0; i < dlm_local_count; i++) {
- memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr));
- make_sockaddr(&localaddr, dlm_config.tcp_port, &addr_len);
-
- result = add_bind_addr(&localaddr, addr_len, num);
- if (result)
- goto create_delsock;
- ++num;
- }
-
- result = sock->ops->listen(sock, 5);
- if (result < 0) {
- log_print("Can't set socket listening");
- goto create_delsock;
- }
-
- return 0;
-
- create_delsock:
- sock_release(sock);
- sctp_con.sock = NULL;
- out:
- return result;
-}
-
-
-static struct writequeue_entry *new_writequeue_entry(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;
-
- return entry;
-}
-
-void *dlm_lowcomms_get_buffer(int nodeid, int len, gfp_t allocation, char **ppc)
-{
- struct writequeue_entry *e;
- int offset = 0;
- int users = 0;
- struct nodeinfo *ni;
-
- if (!atomic_read(&accepting))
- return NULL;
-
- ni = nodeid2nodeinfo(nodeid, allocation);
- if (!ni)
- return NULL;
-
- spin_lock(&ni->writequeue_lock);
- e = list_entry(ni->writequeue.prev, struct writequeue_entry, list);
- if (((struct list_head *) e == &ni->writequeue) ||
- (PAGE_CACHE_SIZE - e->end < len)) {
- e = NULL;
- } else {
- offset = e->end;
- e->end += len;
- users = e->users++;
- }
- spin_unlock(&ni->writequeue_lock);
-
- if (e) {
- got_one:
- if (users == 0)
- kmap(e->page);
- *ppc = page_address(e->page) + offset;
- return e;
- }
-
- e = new_writequeue_entry(allocation);
- if (e) {
- spin_lock(&ni->writequeue_lock);
- offset = e->end;
- e->end += len;
- e->ni = ni;
- users = e->users++;
- list_add_tail(&e->list, &ni->writequeue);
- spin_unlock(&ni->writequeue_lock);
- goto got_one;
- }
- return NULL;
-}
-
-void dlm_lowcomms_commit_buffer(void *arg)
-{
- struct writequeue_entry *e = (struct writequeue_entry *) arg;
- int users;
- struct nodeinfo *ni = e->ni;
-
- if (!atomic_read(&accepting))
- return;
-
- spin_lock(&ni->writequeue_lock);
- users = --e->users;
- if (users)
- goto out;
- e->len = e->end - e->offset;
- kunmap(e->page);
- spin_unlock(&ni->writequeue_lock);
-
- if (!test_and_set_bit(NI_WRITE_PENDING, &ni->flags)) {
- spin_lock_bh(&write_nodes_lock);
- list_add_tail(&ni->write_list, &write_nodes);
- spin_unlock_bh(&write_nodes_lock);
- wake_up_process(send_task);
- }
- return;
-
- out:
- spin_unlock(&ni->writequeue_lock);
- return;
-}
-
-static void free_entry(struct writequeue_entry *e)
-{
- __free_page(e->page);
- kfree(e);
-}
-
-/* Initiate an SCTP association. In theory we could just use sendmsg() on
- the first IP address and it should work, but this allows us to set up the
- association before sending any valuable data that we can't afford to lose.
- It also keeps the send path clean as it can now always use the association ID */
-static void initiate_association(int nodeid)
-{
- struct sockaddr_storage rem_addr;
- static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
- struct msghdr outmessage;
- struct cmsghdr *cmsg;
- struct sctp_sndrcvinfo *sinfo;
- int ret;
- int addrlen;
- char buf[1];
- struct kvec iov[1];
- struct nodeinfo *ni;
-
- log_print("Initiating association with node %d", nodeid);
-
- ni = nodeid2nodeinfo(nodeid, GFP_KERNEL);
- if (!ni)
- return;
-
- if (nodeid_to_addr(nodeid, (struct sockaddr *)&rem_addr)) {
- log_print("no address for nodeid %d", nodeid);
- return;
- }
-
- make_sockaddr(&rem_addr, dlm_config.tcp_port, &addrlen);
-
- outmessage.msg_name = &rem_addr;
- outmessage.msg_namelen = addrlen;
- outmessage.msg_control = outcmsg;
- outmessage.msg_controllen = sizeof(outcmsg);
- outmessage.msg_flags = MSG_EOR;
-
- iov[0].iov_base = buf;
- iov[0].iov_len = 1;
-
- /* Real INIT messages seem to cause trouble. Just send a 1 byte message
- we can afford to lose */
- cmsg = CMSG_FIRSTHDR(&outmessage);
- cmsg->cmsg_level = IPPROTO_SCTP;
- cmsg->cmsg_type = SCTP_SNDRCV;
- cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
- sinfo = (struct sctp_sndrcvinfo *)CMSG_DATA(cmsg);
- memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
- sinfo->sinfo_ppid = cpu_to_le32(dlm_local_nodeid);
-
- outmessage.msg_controllen = cmsg->cmsg_len;
- ret = kernel_sendmsg(sctp_con.sock, &outmessage, iov, 1, 1);
- if (ret < 0) {
- log_print("send INIT to node failed: %d", ret);
- /* Try again later */
- clear_bit(NI_INIT_PENDING, &ni->flags);
- }
-}
-
-/* Send a message */
-static int send_to_sock(struct nodeinfo *ni)
-{
- int ret = 0;
- struct writequeue_entry *e;
- int len, offset;
- struct msghdr outmsg;
- static char outcmsg[CMSG_SPACE(sizeof(struct sctp_sndrcvinfo))];
- struct cmsghdr *cmsg;
- struct sctp_sndrcvinfo *sinfo;
- struct kvec iov;
-
- /* See if we need to init an association before we start
- sending precious messages */
- spin_lock(&ni->lock);
- if (!ni->assoc_id && !test_and_set_bit(NI_INIT_PENDING, &ni->flags)) {
- spin_unlock(&ni->lock);
- initiate_association(ni->nodeid);
- return 0;
- }
- spin_unlock(&ni->lock);
-
- outmsg.msg_name = NULL; /* We use assoc_id */
- outmsg.msg_namelen = 0;
- outmsg.msg_control = outcmsg;
- outmsg.msg_controllen = sizeof(outcmsg);
- outmsg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL | MSG_EOR;
-
- cmsg = CMSG_FIRSTHDR(&outmsg);
- cmsg->cmsg_level = IPPROTO_SCTP;
- cmsg->cmsg_type = SCTP_SNDRCV;
- cmsg->cmsg_len = CMSG_LEN(sizeof(struct sctp_sndrcvinfo));
- sinfo = (struct sctp_sndrcvinfo *)CMSG_DATA(cmsg);
- memset(sinfo, 0x00, sizeof(struct sctp_sndrcvinfo));
- sinfo->sinfo_ppid = cpu_to_le32(dlm_local_nodeid);
- sinfo->sinfo_assoc_id = ni->assoc_id;
- outmsg.msg_controllen = cmsg->cmsg_len;
-
- spin_lock(&ni->writequeue_lock);
- for (;;) {
- if (list_empty(&ni->writequeue))
- break;
- e = list_entry(ni->writequeue.next, struct writequeue_entry,
- list);
- len = e->len;
- offset = e->offset;
- BUG_ON(len == 0 && e->users == 0);
- spin_unlock(&ni->writequeue_lock);
- kmap(e->page);
-
- ret = 0;
- if (len) {
- iov.iov_base = page_address(e->page)+offset;
- iov.iov_len = len;
-
- ret = kernel_sendmsg(sctp_con.sock, &outmsg, &iov, 1,
- len);
- if (ret == -EAGAIN) {
- sctp_con.eagain_flag = 1;
- goto out;
- } else if (ret < 0)
- goto send_error;
- } else {
- /* Don't starve people filling buffers */
- schedule();
- }
-
- spin_lock(&ni->writequeue_lock);
- e->offset += ret;
- e->len -= ret;
-
- if (e->len == 0 && e->users == 0) {
- list_del(&e->list);
- free_entry(e);
- continue;
- }
- }
- spin_unlock(&ni->writequeue_lock);
- out:
- return ret;
-
- send_error:
- log_print("Error sending to node %d %d", ni->nodeid, ret);
- spin_lock(&ni->lock);
- if (!test_and_set_bit(NI_INIT_PENDING, &ni->flags)) {
- ni->assoc_id = 0;
- spin_unlock(&ni->lock);
- initiate_association(ni->nodeid);
- } else
- spin_unlock(&ni->lock);
-
- return ret;
-}
-
-/* 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_nodes_lock);
- list_for_each_safe(list, temp, &write_nodes) {
- struct nodeinfo *ni =
- list_entry(list, struct nodeinfo, write_list);
- clear_bit(NI_WRITE_PENDING, &ni->flags);
- list_del(&ni->write_list);
-
- spin_unlock_bh(&write_nodes_lock);
-
- send_to_sock(ni);
- spin_lock_bh(&write_nodes_lock);
- }
- spin_unlock_bh(&write_nodes_lock);
-}
-
-/* Called after we've had -EAGAIN and been woken up */
-static void refill_write_queue(void)
-{
- int i;
-
- for (i=1; i<=max_nodeid; i++) {
- struct nodeinfo *ni = nodeid2nodeinfo(i, 0);
-
- if (ni) {
- if (!test_and_set_bit(NI_WRITE_PENDING, &ni->flags)) {
- spin_lock_bh(&write_nodes_lock);
- list_add_tail(&ni->write_list, &write_nodes);
- spin_unlock_bh(&write_nodes_lock);
- }
- }
- }
-}
-
-static void clean_one_writequeue(struct nodeinfo *ni)
-{
- struct list_head *list;
- struct list_head *temp;
-
- spin_lock(&ni->writequeue_lock);
- list_for_each_safe(list, temp, &ni->writequeue) {
- struct writequeue_entry *e =
- list_entry(list, struct writequeue_entry, list);
- list_del(&e->list);
- free_entry(e);
- }
- spin_unlock(&ni->writequeue_lock);
-}
-
-static void clean_writequeues(void)
-{
- int i;
-
- for (i=1; i<=max_nodeid; i++) {
- struct nodeinfo *ni = nodeid2nodeinfo(i, 0);
- if (ni)
- clean_one_writequeue(ni);
- }
-}
-
-
-static void dealloc_nodeinfo(void)
-{
- int i;
-
- for (i=1; i<=max_nodeid; i++) {
- struct nodeinfo *ni = nodeid2nodeinfo(i, 0);
- if (ni) {
- idr_remove(&nodeinfo_idr, i);
- kfree(ni);
- }
- }
-}
-
-int dlm_lowcomms_close(int nodeid)
-{
- struct nodeinfo *ni;
-
- ni = nodeid2nodeinfo(nodeid, 0);
- if (!ni)
- return -1;
-
- spin_lock(&ni->lock);
- if (ni->assoc_id) {
- ni->assoc_id = 0;
- /* Don't send shutdown here, sctp will just queue it
- till the node comes back up! */
- }
- spin_unlock(&ni->lock);
-
- clean_one_writequeue(ni);
- clear_bit(NI_INIT_PENDING, &ni->flags);
- return 0;
-}
-
-static int write_list_empty(void)
-{
- int status;
-
- spin_lock_bh(&write_nodes_lock);
- status = list_empty(&write_nodes);
- spin_unlock_bh(&write_nodes_lock);
-
- return status;
-}
-
-static int dlm_recvd(void *data)
-{
- DECLARE_WAITQUEUE(wait, current);
-
- while (!kthread_should_stop()) {
- int count = 0;
-
- set_current_state(TASK_INTERRUPTIBLE);
- add_wait_queue(&lowcomms_recv_wait, &wait);
- if (!test_bit(CF_READ_PENDING, &sctp_con.flags))
- schedule();
- remove_wait_queue(&lowcomms_recv_wait, &wait);
- set_current_state(TASK_RUNNING);
-
- if (test_and_clear_bit(CF_READ_PENDING, &sctp_con.flags)) {
- int ret;
-
- do {
- ret = receive_from_sock();
-
- /* Don't starve out everyone else */
- if (++count >= MAX_RX_MSG_COUNT) {
- schedule();
- count = 0;
- }
- } while (!kthread_should_stop() && ret >=0);
- }
- schedule();
- }
-
- return 0;
-}
-
-static int dlm_sendd(void *data)
-{
- DECLARE_WAITQUEUE(wait, current);
-
- add_wait_queue(sctp_con.sock->sk->sk_sleep, &wait);
-
- while (!kthread_should_stop()) {
- set_current_state(TASK_INTERRUPTIBLE);
- if (write_list_empty())
- schedule();
- set_current_state(TASK_RUNNING);
-
- if (sctp_con.eagain_flag) {
- sctp_con.eagain_flag = 0;
- refill_write_queue();
- }
- process_output_queue();
- }
-
- remove_wait_queue(sctp_con.sock->sk->sk_sleep, &wait);
-
- 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);
- if (error) {
- log_print("can't start dlm_recvd %d", error);
- return error;
- }
- recv_task = p;
-
- p = kthread_run(dlm_sendd, NULL, "dlm_sendd");
- error = IS_ERR(p);
- if (error) {
- log_print("can't start dlm_sendd %d", error);
- kthread_stop(recv_task);
- return error;
- }
- send_task = p;
-
- return 0;
-}
-
-/*
- * This is quite likely to sleep...
- */
-int dlm_lowcomms_start(void)
-{
- int error;
-
- error = init_sock();
- if (error)
- goto fail_sock;
- error = daemons_start();
- if (error)
- goto fail_sock;
- atomic_set(&accepting, 1);
- return 0;
-
- fail_sock:
- close_connection();
- return error;
-}
-
-/* Set all the activity flags to prevent any socket activity. */
-
-void dlm_lowcomms_stop(void)
-{
- atomic_set(&accepting, 0);
- sctp_con.flags = 0x7;
- daemons_stop();
- clean_writequeues();
- close_connection();
- dealloc_nodeinfo();
- max_nodeid = 0;
-}
-
-int dlm_lowcomms_init(void)
-{
- init_waitqueue_head(&lowcomms_recv_wait);
- spin_lock_init(&write_nodes_lock);
- INIT_LIST_HEAD(&write_nodes);
- init_rwsem(&nodeinfo_lock);
- return 0;
-}
-
-void dlm_lowcomms_exit(void)
-{
- int i;
-
- for (i = 0; i < dlm_local_count; i++)
- kfree(dlm_local_addr[i]);
- dlm_local_count = 0;
- dlm_local_nodeid = 0;
-}
-
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff