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-rw-r--r--fs/dlm/lowcomms-sctp.c1210
1 files changed, 0 insertions, 1210 deletions
diff --git a/fs/dlm/lowcomms-sctp.c b/fs/dlm/lowcomms-sctp.c
deleted file mode 100644
index dc83a9d979b5..000000000000
--- a/fs/dlm/lowcomms-sctp.c
+++ /dev/null
@@ -1,1210 +0,0 @@
-/******************************************************************************
-*******************************************************************************
-**
-** 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 (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;
- struct work_struct swork; /* Send workqueue */
- struct work_struct lwork; /* Locking workqueue */
-};
-
-static DEFINE_IDR(nodeinfo_idr);
-static DECLARE_RWSEM(nodeinfo_lock);
-static int max_nodeid;
-
-struct cbuf {
- unsigned int base;
- unsigned int len;
- unsigned int 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;
- struct work_struct work; /* Send workqueue */
-};
-
-/* 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;
-};
-
-static void cbuf_add(struct cbuf *cb, int n)
-{
- cb->len += n;
-}
-
-static int cbuf_data(struct cbuf *cb)
-{
- return ((cb->base + cb->len) & cb->mask);
-}
-
-static void cbuf_init(struct cbuf *cb, int size)
-{
- cb->base = cb->len = 0;
- cb->mask = size-1;
-}
-
-static void cbuf_eat(struct cbuf *cb, int n)
-{
- cb->len -= n;
- cb->base += n;
- cb->base &= cb->mask;
-}
-
-/* List of nodes which have writes pending */
-static LIST_HEAD(write_nodes);
-static DEFINE_SPINLOCK(write_nodes_lock);
-
-
-/* Maximum number of incoming messages to process before
- * doing a schedule()
- */
-#define MAX_RX_MSG_COUNT 25
-
-/* Work queues */
-static struct workqueue_struct *recv_workqueue;
-static struct workqueue_struct *send_workqueue;
-static struct workqueue_struct *lock_workqueue;
-
-/* The SCTP connection */
-static struct connection sctp_con;
-
-static void process_send_sockets(struct work_struct *work);
-static void process_recv_sockets(struct work_struct *work);
-static void process_lock_request(struct work_struct *work);
-
-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;
-}
-
-/* If alloc is 0 here we will not attempt to allocate a new
- nodeinfo struct */
-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)
- return ni;
-
- 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);
- INIT_WORK(&ni->lwork, process_lock_request);
- INIT_WORK(&ni->swork, process_send_sockets);
- 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)
-{
- if (test_and_set_bit(CF_READ_PENDING, &sctp_con.flags))
- queue_work(recv_workqueue, &sctp_con.work);
-}
-
-
-/* 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 = 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);
- queue_work(send_workqueue, &ni->swork);
- }
- }
- }
-}
-
-/* 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 */
- ni->assoc_id = sn->sn_assoc_change.sac_assoc_id;
-
- 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);
- queue_work(send_workqueue, &ni->swork);
- }
- }
- 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));
-
- 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 = 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);
- queue_work(send_workqueue, &ni->swork);
- }
- }
- }
-
- /* INIT sends a message with length of 1 - ignore it */
- if (r == 1)
- return 0;
-
- cbuf_add(&sctp_con.cb, ret);
- // PJC: TODO: Add to node's workqueue....can we ??
- 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;
- cond_resched();
- 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.ci_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.ci_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;
-
- ni = nodeid2nodeinfo(nodeid, allocation);
- if (!ni)
- return NULL;
-
- spin_lock(&ni->writequeue_lock);
- e = list_entry(ni->writequeue.prev, struct writequeue_entry, list);
- if ((&e->list == &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;
-
- 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);
-
- queue_work(send_workqueue, &ni->swork);
- }
- 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.ci_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 = 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 void 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;
- }
- 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 = 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 */
- cond_resched();
- }
-
- spin_lock(&ni->writequeue_lock);
- e->offset += ret;
- e->len -= ret;
-
- if (e->len == 0 && e->users == 0) {
- list_del(&e->list);
- kunmap(e->page);
- free_entry(e);
- continue;
- }
- }
- spin_unlock(&ni->writequeue_lock);
-out:
- return;
-
-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;
-}
-
-/* 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;
-}
-
-// PJC: The work queue function for receiving.
-static void process_recv_sockets(struct work_struct *work)
-{
- if (test_and_clear_bit(CF_READ_PENDING, &sctp_con.flags)) {
- int ret;
- int count = 0;
-
- do {
- ret = receive_from_sock();
-
- /* Don't starve out everyone else */
- if (++count >= MAX_RX_MSG_COUNT) {
- cond_resched();
- count = 0;
- }
- } while (!kthread_should_stop() && ret >=0);
- }
- cond_resched();
-}
-
-// PJC: the work queue function for sending
-static void process_send_sockets(struct work_struct *work)
-{
- if (sctp_con.eagain_flag) {
- sctp_con.eagain_flag = 0;
- refill_write_queue();
- }
- process_output_queue();
-}
-
-// PJC: Process lock requests from a particular node.
-// TODO: can we optimise this out on UP ??
-static void process_lock_request(struct work_struct *work)
-{
-}
-
-static void daemons_stop(void)
-{
- destroy_workqueue(recv_workqueue);
- destroy_workqueue(send_workqueue);
- destroy_workqueue(lock_workqueue);
-}
-
-static int daemons_start(void)
-{
- int error;
- recv_workqueue = create_workqueue("dlm_recv");
- error = IS_ERR(recv_workqueue);
- if (error) {
- log_print("can't start dlm_recv %d", error);
- return error;
- }
-
- send_workqueue = create_singlethread_workqueue("dlm_send");
- error = IS_ERR(send_workqueue);
- if (error) {
- log_print("can't start dlm_send %d", error);
- destroy_workqueue(recv_workqueue);
- return error;
- }
-
- lock_workqueue = create_workqueue("dlm_rlock");
- error = IS_ERR(lock_workqueue);
- if (error) {
- log_print("can't start dlm_rlock %d", error);
- destroy_workqueue(send_workqueue);
- destroy_workqueue(recv_workqueue);
- return error;
- }
-
- return 0;
-}
-
-/*
- * This is quite likely to sleep...
- */
-int dlm_lowcomms_start(void)
-{
- int error;
-
- INIT_WORK(&sctp_con.work, process_recv_sockets);
-
- error = init_sock();
- if (error)
- goto fail_sock;
- error = daemons_start();
- if (error)
- goto fail_sock;
- return 0;
-
-fail_sock:
- close_connection();
- return error;
-}
-
-void dlm_lowcomms_stop(void)
-{
- int i;
-
- sctp_con.flags = 0x7;
- daemons_stop();
- clean_writequeues();
- close_connection();
- dealloc_nodeinfo();
- max_nodeid = 0;
-
- dlm_local_count = 0;
- dlm_local_nodeid = 0;
-
- for (i = 0; i < dlm_local_count; i++)
- kfree(dlm_local_addr[i]);
-}
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