v4.19.13 snapshot.
diff --git a/fs/ocfs2/cluster/tcp.c b/fs/ocfs2/cluster/tcp.c
new file mode 100644
index 0000000..7d9eea7
--- /dev/null
+++ b/fs/ocfs2/cluster/tcp.c
@@ -0,0 +1,2195 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ *
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * Copyright (C) 2004 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ *
+ * ----
+ *
+ * Callers for this were originally written against a very simple synchronus
+ * API. This implementation reflects those simple callers. Some day I'm sure
+ * we'll need to move to a more robust posting/callback mechanism.
+ *
+ * Transmit calls pass in kernel virtual addresses and block copying this into
+ * the socket's tx buffers via a usual blocking sendmsg. They'll block waiting
+ * for a failed socket to timeout. TX callers can also pass in a poniter to an
+ * 'int' which gets filled with an errno off the wire in response to the
+ * message they send.
+ *
+ * Handlers for unsolicited messages are registered. Each socket has a page
+ * that incoming data is copied into. First the header, then the data.
+ * Handlers are called from only one thread with a reference to this per-socket
+ * page. This page is destroyed after the handler call, so it can't be
+ * referenced beyond the call. Handlers may block but are discouraged from
+ * doing so.
+ *
+ * Any framing errors (bad magic, large payload lengths) close a connection.
+ *
+ * Our sock_container holds the state we associate with a socket. It's current
+ * framing state is held there as well as the refcounting we do around when it
+ * is safe to tear down the socket. The socket is only finally torn down from
+ * the container when the container loses all of its references -- so as long
+ * as you hold a ref on the container you can trust that the socket is valid
+ * for use with kernel socket APIs.
+ *
+ * Connections are initiated between a pair of nodes when the node with the
+ * higher node number gets a heartbeat callback which indicates that the lower
+ * numbered node has started heartbeating. The lower numbered node is passive
+ * and only accepts the connection if the higher numbered node is heartbeating.
+ */
+
+#include <linux/kernel.h>
+#include <linux/sched/mm.h>
+#include <linux/jiffies.h>
+#include <linux/slab.h>
+#include <linux/idr.h>
+#include <linux/kref.h>
+#include <linux/net.h>
+#include <linux/export.h>
+#include <net/tcp.h>
+
+#include <linux/uaccess.h>
+
+#include "heartbeat.h"
+#include "tcp.h"
+#include "nodemanager.h"
+#define MLOG_MASK_PREFIX ML_TCP
+#include "masklog.h"
+#include "quorum.h"
+
+#include "tcp_internal.h"
+
+#define SC_NODEF_FMT "node %s (num %u) at %pI4:%u"
+#define SC_NODEF_ARGS(sc) sc->sc_node->nd_name, sc->sc_node->nd_num, \
+ &sc->sc_node->nd_ipv4_address, \
+ ntohs(sc->sc_node->nd_ipv4_port)
+
+/*
+ * In the following two log macros, the whitespace after the ',' just
+ * before ##args is intentional. Otherwise, gcc 2.95 will eat the
+ * previous token if args expands to nothing.
+ */
+#define msglog(hdr, fmt, args...) do { \
+ typeof(hdr) __hdr = (hdr); \
+ mlog(ML_MSG, "[mag %u len %u typ %u stat %d sys_stat %d " \
+ "key %08x num %u] " fmt, \
+ be16_to_cpu(__hdr->magic), be16_to_cpu(__hdr->data_len), \
+ be16_to_cpu(__hdr->msg_type), be32_to_cpu(__hdr->status), \
+ be32_to_cpu(__hdr->sys_status), be32_to_cpu(__hdr->key), \
+ be32_to_cpu(__hdr->msg_num) , ##args); \
+} while (0)
+
+#define sclog(sc, fmt, args...) do { \
+ typeof(sc) __sc = (sc); \
+ mlog(ML_SOCKET, "[sc %p refs %d sock %p node %u page %p " \
+ "pg_off %zu] " fmt, __sc, \
+ kref_read(&__sc->sc_kref), __sc->sc_sock, \
+ __sc->sc_node->nd_num, __sc->sc_page, __sc->sc_page_off , \
+ ##args); \
+} while (0)
+
+static DEFINE_RWLOCK(o2net_handler_lock);
+static struct rb_root o2net_handler_tree = RB_ROOT;
+
+static struct o2net_node o2net_nodes[O2NM_MAX_NODES];
+
+/* XXX someday we'll need better accounting */
+static struct socket *o2net_listen_sock;
+
+/*
+ * listen work is only queued by the listening socket callbacks on the
+ * o2net_wq. teardown detaches the callbacks before destroying the workqueue.
+ * quorum work is queued as sock containers are shutdown.. stop_listening
+ * tears down all the node's sock containers, preventing future shutdowns
+ * and queued quroum work, before canceling delayed quorum work and
+ * destroying the work queue.
+ */
+static struct workqueue_struct *o2net_wq;
+static struct work_struct o2net_listen_work;
+
+static struct o2hb_callback_func o2net_hb_up, o2net_hb_down;
+#define O2NET_HB_PRI 0x1
+
+static struct o2net_handshake *o2net_hand;
+static struct o2net_msg *o2net_keep_req, *o2net_keep_resp;
+
+static int o2net_sys_err_translations[O2NET_ERR_MAX] =
+ {[O2NET_ERR_NONE] = 0,
+ [O2NET_ERR_NO_HNDLR] = -ENOPROTOOPT,
+ [O2NET_ERR_OVERFLOW] = -EOVERFLOW,
+ [O2NET_ERR_DIED] = -EHOSTDOWN,};
+
+/* can't quite avoid *all* internal declarations :/ */
+static void o2net_sc_connect_completed(struct work_struct *work);
+static void o2net_rx_until_empty(struct work_struct *work);
+static void o2net_shutdown_sc(struct work_struct *work);
+static void o2net_listen_data_ready(struct sock *sk);
+static void o2net_sc_send_keep_req(struct work_struct *work);
+static void o2net_idle_timer(struct timer_list *t);
+static void o2net_sc_postpone_idle(struct o2net_sock_container *sc);
+static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc);
+
+#ifdef CONFIG_DEBUG_FS
+static void o2net_init_nst(struct o2net_send_tracking *nst, u32 msgtype,
+ u32 msgkey, struct task_struct *task, u8 node)
+{
+ INIT_LIST_HEAD(&nst->st_net_debug_item);
+ nst->st_task = task;
+ nst->st_msg_type = msgtype;
+ nst->st_msg_key = msgkey;
+ nst->st_node = node;
+}
+
+static inline void o2net_set_nst_sock_time(struct o2net_send_tracking *nst)
+{
+ nst->st_sock_time = ktime_get();
+}
+
+static inline void o2net_set_nst_send_time(struct o2net_send_tracking *nst)
+{
+ nst->st_send_time = ktime_get();
+}
+
+static inline void o2net_set_nst_status_time(struct o2net_send_tracking *nst)
+{
+ nst->st_status_time = ktime_get();
+}
+
+static inline void o2net_set_nst_sock_container(struct o2net_send_tracking *nst,
+ struct o2net_sock_container *sc)
+{
+ nst->st_sc = sc;
+}
+
+static inline void o2net_set_nst_msg_id(struct o2net_send_tracking *nst,
+ u32 msg_id)
+{
+ nst->st_id = msg_id;
+}
+
+static inline void o2net_set_sock_timer(struct o2net_sock_container *sc)
+{
+ sc->sc_tv_timer = ktime_get();
+}
+
+static inline void o2net_set_data_ready_time(struct o2net_sock_container *sc)
+{
+ sc->sc_tv_data_ready = ktime_get();
+}
+
+static inline void o2net_set_advance_start_time(struct o2net_sock_container *sc)
+{
+ sc->sc_tv_advance_start = ktime_get();
+}
+
+static inline void o2net_set_advance_stop_time(struct o2net_sock_container *sc)
+{
+ sc->sc_tv_advance_stop = ktime_get();
+}
+
+static inline void o2net_set_func_start_time(struct o2net_sock_container *sc)
+{
+ sc->sc_tv_func_start = ktime_get();
+}
+
+static inline void o2net_set_func_stop_time(struct o2net_sock_container *sc)
+{
+ sc->sc_tv_func_stop = ktime_get();
+}
+
+#else /* CONFIG_DEBUG_FS */
+# define o2net_init_nst(a, b, c, d, e)
+# define o2net_set_nst_sock_time(a)
+# define o2net_set_nst_send_time(a)
+# define o2net_set_nst_status_time(a)
+# define o2net_set_nst_sock_container(a, b)
+# define o2net_set_nst_msg_id(a, b)
+# define o2net_set_sock_timer(a)
+# define o2net_set_data_ready_time(a)
+# define o2net_set_advance_start_time(a)
+# define o2net_set_advance_stop_time(a)
+# define o2net_set_func_start_time(a)
+# define o2net_set_func_stop_time(a)
+#endif /* CONFIG_DEBUG_FS */
+
+#ifdef CONFIG_OCFS2_FS_STATS
+static ktime_t o2net_get_func_run_time(struct o2net_sock_container *sc)
+{
+ return ktime_sub(sc->sc_tv_func_stop, sc->sc_tv_func_start);
+}
+
+static void o2net_update_send_stats(struct o2net_send_tracking *nst,
+ struct o2net_sock_container *sc)
+{
+ sc->sc_tv_status_total = ktime_add(sc->sc_tv_status_total,
+ ktime_sub(ktime_get(),
+ nst->st_status_time));
+ sc->sc_tv_send_total = ktime_add(sc->sc_tv_send_total,
+ ktime_sub(nst->st_status_time,
+ nst->st_send_time));
+ sc->sc_tv_acquiry_total = ktime_add(sc->sc_tv_acquiry_total,
+ ktime_sub(nst->st_send_time,
+ nst->st_sock_time));
+ sc->sc_send_count++;
+}
+
+static void o2net_update_recv_stats(struct o2net_sock_container *sc)
+{
+ sc->sc_tv_process_total = ktime_add(sc->sc_tv_process_total,
+ o2net_get_func_run_time(sc));
+ sc->sc_recv_count++;
+}
+
+#else
+
+# define o2net_update_send_stats(a, b)
+
+# define o2net_update_recv_stats(sc)
+
+#endif /* CONFIG_OCFS2_FS_STATS */
+
+static inline unsigned int o2net_reconnect_delay(void)
+{
+ return o2nm_single_cluster->cl_reconnect_delay_ms;
+}
+
+static inline unsigned int o2net_keepalive_delay(void)
+{
+ return o2nm_single_cluster->cl_keepalive_delay_ms;
+}
+
+static inline unsigned int o2net_idle_timeout(void)
+{
+ return o2nm_single_cluster->cl_idle_timeout_ms;
+}
+
+static inline int o2net_sys_err_to_errno(enum o2net_system_error err)
+{
+ int trans;
+ BUG_ON(err >= O2NET_ERR_MAX);
+ trans = o2net_sys_err_translations[err];
+
+ /* Just in case we mess up the translation table above */
+ BUG_ON(err != O2NET_ERR_NONE && trans == 0);
+ return trans;
+}
+
+static struct o2net_node * o2net_nn_from_num(u8 node_num)
+{
+ BUG_ON(node_num >= ARRAY_SIZE(o2net_nodes));
+ return &o2net_nodes[node_num];
+}
+
+static u8 o2net_num_from_nn(struct o2net_node *nn)
+{
+ BUG_ON(nn == NULL);
+ return nn - o2net_nodes;
+}
+
+/* ------------------------------------------------------------ */
+
+static int o2net_prep_nsw(struct o2net_node *nn, struct o2net_status_wait *nsw)
+{
+ int ret;
+
+ spin_lock(&nn->nn_lock);
+ ret = idr_alloc(&nn->nn_status_idr, nsw, 0, 0, GFP_ATOMIC);
+ if (ret >= 0) {
+ nsw->ns_id = ret;
+ list_add_tail(&nsw->ns_node_item, &nn->nn_status_list);
+ }
+ spin_unlock(&nn->nn_lock);
+ if (ret < 0)
+ return ret;
+
+ init_waitqueue_head(&nsw->ns_wq);
+ nsw->ns_sys_status = O2NET_ERR_NONE;
+ nsw->ns_status = 0;
+ return 0;
+}
+
+static void o2net_complete_nsw_locked(struct o2net_node *nn,
+ struct o2net_status_wait *nsw,
+ enum o2net_system_error sys_status,
+ s32 status)
+{
+ assert_spin_locked(&nn->nn_lock);
+
+ if (!list_empty(&nsw->ns_node_item)) {
+ list_del_init(&nsw->ns_node_item);
+ nsw->ns_sys_status = sys_status;
+ nsw->ns_status = status;
+ idr_remove(&nn->nn_status_idr, nsw->ns_id);
+ wake_up(&nsw->ns_wq);
+ }
+}
+
+static void o2net_complete_nsw(struct o2net_node *nn,
+ struct o2net_status_wait *nsw,
+ u64 id, enum o2net_system_error sys_status,
+ s32 status)
+{
+ spin_lock(&nn->nn_lock);
+ if (nsw == NULL) {
+ if (id > INT_MAX)
+ goto out;
+
+ nsw = idr_find(&nn->nn_status_idr, id);
+ if (nsw == NULL)
+ goto out;
+ }
+
+ o2net_complete_nsw_locked(nn, nsw, sys_status, status);
+
+out:
+ spin_unlock(&nn->nn_lock);
+ return;
+}
+
+static void o2net_complete_nodes_nsw(struct o2net_node *nn)
+{
+ struct o2net_status_wait *nsw, *tmp;
+ unsigned int num_kills = 0;
+
+ assert_spin_locked(&nn->nn_lock);
+
+ list_for_each_entry_safe(nsw, tmp, &nn->nn_status_list, ns_node_item) {
+ o2net_complete_nsw_locked(nn, nsw, O2NET_ERR_DIED, 0);
+ num_kills++;
+ }
+
+ mlog(0, "completed %d messages for node %u\n", num_kills,
+ o2net_num_from_nn(nn));
+}
+
+static int o2net_nsw_completed(struct o2net_node *nn,
+ struct o2net_status_wait *nsw)
+{
+ int completed;
+ spin_lock(&nn->nn_lock);
+ completed = list_empty(&nsw->ns_node_item);
+ spin_unlock(&nn->nn_lock);
+ return completed;
+}
+
+/* ------------------------------------------------------------ */
+
+static void sc_kref_release(struct kref *kref)
+{
+ struct o2net_sock_container *sc = container_of(kref,
+ struct o2net_sock_container, sc_kref);
+ BUG_ON(timer_pending(&sc->sc_idle_timeout));
+
+ sclog(sc, "releasing\n");
+
+ if (sc->sc_sock) {
+ sock_release(sc->sc_sock);
+ sc->sc_sock = NULL;
+ }
+
+ o2nm_undepend_item(&sc->sc_node->nd_item);
+ o2nm_node_put(sc->sc_node);
+ sc->sc_node = NULL;
+
+ o2net_debug_del_sc(sc);
+
+ if (sc->sc_page)
+ __free_page(sc->sc_page);
+ kfree(sc);
+}
+
+static void sc_put(struct o2net_sock_container *sc)
+{
+ sclog(sc, "put\n");
+ kref_put(&sc->sc_kref, sc_kref_release);
+}
+static void sc_get(struct o2net_sock_container *sc)
+{
+ sclog(sc, "get\n");
+ kref_get(&sc->sc_kref);
+}
+static struct o2net_sock_container *sc_alloc(struct o2nm_node *node)
+{
+ struct o2net_sock_container *sc, *ret = NULL;
+ struct page *page = NULL;
+ int status = 0;
+
+ page = alloc_page(GFP_NOFS);
+ sc = kzalloc(sizeof(*sc), GFP_NOFS);
+ if (sc == NULL || page == NULL)
+ goto out;
+
+ kref_init(&sc->sc_kref);
+ o2nm_node_get(node);
+ sc->sc_node = node;
+
+ /* pin the node item of the remote node */
+ status = o2nm_depend_item(&node->nd_item);
+ if (status) {
+ mlog_errno(status);
+ o2nm_node_put(node);
+ goto out;
+ }
+ INIT_WORK(&sc->sc_connect_work, o2net_sc_connect_completed);
+ INIT_WORK(&sc->sc_rx_work, o2net_rx_until_empty);
+ INIT_WORK(&sc->sc_shutdown_work, o2net_shutdown_sc);
+ INIT_DELAYED_WORK(&sc->sc_keepalive_work, o2net_sc_send_keep_req);
+
+ timer_setup(&sc->sc_idle_timeout, o2net_idle_timer, 0);
+
+ sclog(sc, "alloced\n");
+
+ ret = sc;
+ sc->sc_page = page;
+ o2net_debug_add_sc(sc);
+ sc = NULL;
+ page = NULL;
+
+out:
+ if (page)
+ __free_page(page);
+ kfree(sc);
+
+ return ret;
+}
+
+/* ------------------------------------------------------------ */
+
+static void o2net_sc_queue_work(struct o2net_sock_container *sc,
+ struct work_struct *work)
+{
+ sc_get(sc);
+ if (!queue_work(o2net_wq, work))
+ sc_put(sc);
+}
+static void o2net_sc_queue_delayed_work(struct o2net_sock_container *sc,
+ struct delayed_work *work,
+ int delay)
+{
+ sc_get(sc);
+ if (!queue_delayed_work(o2net_wq, work, delay))
+ sc_put(sc);
+}
+static void o2net_sc_cancel_delayed_work(struct o2net_sock_container *sc,
+ struct delayed_work *work)
+{
+ if (cancel_delayed_work(work))
+ sc_put(sc);
+}
+
+static atomic_t o2net_connected_peers = ATOMIC_INIT(0);
+
+int o2net_num_connected_peers(void)
+{
+ return atomic_read(&o2net_connected_peers);
+}
+
+static void o2net_set_nn_state(struct o2net_node *nn,
+ struct o2net_sock_container *sc,
+ unsigned valid, int err)
+{
+ int was_valid = nn->nn_sc_valid;
+ int was_err = nn->nn_persistent_error;
+ struct o2net_sock_container *old_sc = nn->nn_sc;
+
+ assert_spin_locked(&nn->nn_lock);
+
+ if (old_sc && !sc)
+ atomic_dec(&o2net_connected_peers);
+ else if (!old_sc && sc)
+ atomic_inc(&o2net_connected_peers);
+
+ /* the node num comparison and single connect/accept path should stop
+ * an non-null sc from being overwritten with another */
+ BUG_ON(sc && nn->nn_sc && nn->nn_sc != sc);
+ mlog_bug_on_msg(err && valid, "err %d valid %u\n", err, valid);
+ mlog_bug_on_msg(valid && !sc, "valid %u sc %p\n", valid, sc);
+
+ if (was_valid && !valid && err == 0)
+ err = -ENOTCONN;
+
+ mlog(ML_CONN, "node %u sc: %p -> %p, valid %u -> %u, err %d -> %d\n",
+ o2net_num_from_nn(nn), nn->nn_sc, sc, nn->nn_sc_valid, valid,
+ nn->nn_persistent_error, err);
+
+ nn->nn_sc = sc;
+ nn->nn_sc_valid = valid ? 1 : 0;
+ nn->nn_persistent_error = err;
+
+ /* mirrors o2net_tx_can_proceed() */
+ if (nn->nn_persistent_error || nn->nn_sc_valid)
+ wake_up(&nn->nn_sc_wq);
+
+ if (was_valid && !was_err && nn->nn_persistent_error) {
+ o2quo_conn_err(o2net_num_from_nn(nn));
+ queue_delayed_work(o2net_wq, &nn->nn_still_up,
+ msecs_to_jiffies(O2NET_QUORUM_DELAY_MS));
+ }
+
+ if (was_valid && !valid) {
+ if (old_sc)
+ printk(KERN_NOTICE "o2net: No longer connected to "
+ SC_NODEF_FMT "\n", SC_NODEF_ARGS(old_sc));
+ o2net_complete_nodes_nsw(nn);
+ }
+
+ if (!was_valid && valid) {
+ o2quo_conn_up(o2net_num_from_nn(nn));
+ cancel_delayed_work(&nn->nn_connect_expired);
+ printk(KERN_NOTICE "o2net: %s " SC_NODEF_FMT "\n",
+ o2nm_this_node() > sc->sc_node->nd_num ?
+ "Connected to" : "Accepted connection from",
+ SC_NODEF_ARGS(sc));
+ }
+
+ /* trigger the connecting worker func as long as we're not valid,
+ * it will back off if it shouldn't connect. This can be called
+ * from node config teardown and so needs to be careful about
+ * the work queue actually being up. */
+ if (!valid && o2net_wq) {
+ unsigned long delay;
+ /* delay if we're within a RECONNECT_DELAY of the
+ * last attempt */
+ delay = (nn->nn_last_connect_attempt +
+ msecs_to_jiffies(o2net_reconnect_delay()))
+ - jiffies;
+ if (delay > msecs_to_jiffies(o2net_reconnect_delay()))
+ delay = 0;
+ mlog(ML_CONN, "queueing conn attempt in %lu jiffies\n", delay);
+ queue_delayed_work(o2net_wq, &nn->nn_connect_work, delay);
+
+ /*
+ * Delay the expired work after idle timeout.
+ *
+ * We might have lots of failed connection attempts that run
+ * through here but we only cancel the connect_expired work when
+ * a connection attempt succeeds. So only the first enqueue of
+ * the connect_expired work will do anything. The rest will see
+ * that it's already queued and do nothing.
+ */
+ delay += msecs_to_jiffies(o2net_idle_timeout());
+ queue_delayed_work(o2net_wq, &nn->nn_connect_expired, delay);
+ }
+
+ /* keep track of the nn's sc ref for the caller */
+ if ((old_sc == NULL) && sc)
+ sc_get(sc);
+ if (old_sc && (old_sc != sc)) {
+ o2net_sc_queue_work(old_sc, &old_sc->sc_shutdown_work);
+ sc_put(old_sc);
+ }
+}
+
+/* see o2net_register_callbacks() */
+static void o2net_data_ready(struct sock *sk)
+{
+ void (*ready)(struct sock *sk);
+ struct o2net_sock_container *sc;
+
+ read_lock_bh(&sk->sk_callback_lock);
+ sc = sk->sk_user_data;
+ if (sc) {
+ sclog(sc, "data_ready hit\n");
+ o2net_set_data_ready_time(sc);
+ o2net_sc_queue_work(sc, &sc->sc_rx_work);
+ ready = sc->sc_data_ready;
+ } else {
+ ready = sk->sk_data_ready;
+ }
+ read_unlock_bh(&sk->sk_callback_lock);
+
+ ready(sk);
+}
+
+/* see o2net_register_callbacks() */
+static void o2net_state_change(struct sock *sk)
+{
+ void (*state_change)(struct sock *sk);
+ struct o2net_sock_container *sc;
+
+ read_lock_bh(&sk->sk_callback_lock);
+ sc = sk->sk_user_data;
+ if (sc == NULL) {
+ state_change = sk->sk_state_change;
+ goto out;
+ }
+
+ sclog(sc, "state_change to %d\n", sk->sk_state);
+
+ state_change = sc->sc_state_change;
+
+ switch(sk->sk_state) {
+ /* ignore connecting sockets as they make progress */
+ case TCP_SYN_SENT:
+ case TCP_SYN_RECV:
+ break;
+ case TCP_ESTABLISHED:
+ o2net_sc_queue_work(sc, &sc->sc_connect_work);
+ break;
+ default:
+ printk(KERN_INFO "o2net: Connection to " SC_NODEF_FMT
+ " shutdown, state %d\n",
+ SC_NODEF_ARGS(sc), sk->sk_state);
+ o2net_sc_queue_work(sc, &sc->sc_shutdown_work);
+ break;
+ }
+out:
+ read_unlock_bh(&sk->sk_callback_lock);
+ state_change(sk);
+}
+
+/*
+ * we register callbacks so we can queue work on events before calling
+ * the original callbacks. our callbacks our careful to test user_data
+ * to discover when they've reaced with o2net_unregister_callbacks().
+ */
+static void o2net_register_callbacks(struct sock *sk,
+ struct o2net_sock_container *sc)
+{
+ write_lock_bh(&sk->sk_callback_lock);
+
+ /* accepted sockets inherit the old listen socket data ready */
+ if (sk->sk_data_ready == o2net_listen_data_ready) {
+ sk->sk_data_ready = sk->sk_user_data;
+ sk->sk_user_data = NULL;
+ }
+
+ BUG_ON(sk->sk_user_data != NULL);
+ sk->sk_user_data = sc;
+ sc_get(sc);
+
+ sc->sc_data_ready = sk->sk_data_ready;
+ sc->sc_state_change = sk->sk_state_change;
+ sk->sk_data_ready = o2net_data_ready;
+ sk->sk_state_change = o2net_state_change;
+
+ mutex_init(&sc->sc_send_lock);
+
+ write_unlock_bh(&sk->sk_callback_lock);
+}
+
+static int o2net_unregister_callbacks(struct sock *sk,
+ struct o2net_sock_container *sc)
+{
+ int ret = 0;
+
+ write_lock_bh(&sk->sk_callback_lock);
+ if (sk->sk_user_data == sc) {
+ ret = 1;
+ sk->sk_user_data = NULL;
+ sk->sk_data_ready = sc->sc_data_ready;
+ sk->sk_state_change = sc->sc_state_change;
+ }
+ write_unlock_bh(&sk->sk_callback_lock);
+
+ return ret;
+}
+
+/*
+ * this is a little helper that is called by callers who have seen a problem
+ * with an sc and want to detach it from the nn if someone already hasn't beat
+ * them to it. if an error is given then the shutdown will be persistent
+ * and pending transmits will be canceled.
+ */
+static void o2net_ensure_shutdown(struct o2net_node *nn,
+ struct o2net_sock_container *sc,
+ int err)
+{
+ spin_lock(&nn->nn_lock);
+ if (nn->nn_sc == sc)
+ o2net_set_nn_state(nn, NULL, 0, err);
+ spin_unlock(&nn->nn_lock);
+}
+
+/*
+ * This work queue function performs the blocking parts of socket shutdown. A
+ * few paths lead here. set_nn_state will trigger this callback if it sees an
+ * sc detached from the nn. state_change will also trigger this callback
+ * directly when it sees errors. In that case we need to call set_nn_state
+ * ourselves as state_change couldn't get the nn_lock and call set_nn_state
+ * itself.
+ */
+static void o2net_shutdown_sc(struct work_struct *work)
+{
+ struct o2net_sock_container *sc =
+ container_of(work, struct o2net_sock_container,
+ sc_shutdown_work);
+ struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
+
+ sclog(sc, "shutting down\n");
+
+ /* drop the callbacks ref and call shutdown only once */
+ if (o2net_unregister_callbacks(sc->sc_sock->sk, sc)) {
+ /* we shouldn't flush as we're in the thread, the
+ * races with pending sc work structs are harmless */
+ del_timer_sync(&sc->sc_idle_timeout);
+ o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
+ sc_put(sc);
+ kernel_sock_shutdown(sc->sc_sock, SHUT_RDWR);
+ }
+
+ /* not fatal so failed connects before the other guy has our
+ * heartbeat can be retried */
+ o2net_ensure_shutdown(nn, sc, 0);
+ sc_put(sc);
+}
+
+/* ------------------------------------------------------------ */
+
+static int o2net_handler_cmp(struct o2net_msg_handler *nmh, u32 msg_type,
+ u32 key)
+{
+ int ret = memcmp(&nmh->nh_key, &key, sizeof(key));
+
+ if (ret == 0)
+ ret = memcmp(&nmh->nh_msg_type, &msg_type, sizeof(msg_type));
+
+ return ret;
+}
+
+static struct o2net_msg_handler *
+o2net_handler_tree_lookup(u32 msg_type, u32 key, struct rb_node ***ret_p,
+ struct rb_node **ret_parent)
+{
+ struct rb_node **p = &o2net_handler_tree.rb_node;
+ struct rb_node *parent = NULL;
+ struct o2net_msg_handler *nmh, *ret = NULL;
+ int cmp;
+
+ while (*p) {
+ parent = *p;
+ nmh = rb_entry(parent, struct o2net_msg_handler, nh_node);
+ cmp = o2net_handler_cmp(nmh, msg_type, key);
+
+ if (cmp < 0)
+ p = &(*p)->rb_left;
+ else if (cmp > 0)
+ p = &(*p)->rb_right;
+ else {
+ ret = nmh;
+ break;
+ }
+ }
+
+ if (ret_p != NULL)
+ *ret_p = p;
+ if (ret_parent != NULL)
+ *ret_parent = parent;
+
+ return ret;
+}
+
+static void o2net_handler_kref_release(struct kref *kref)
+{
+ struct o2net_msg_handler *nmh;
+ nmh = container_of(kref, struct o2net_msg_handler, nh_kref);
+
+ kfree(nmh);
+}
+
+static void o2net_handler_put(struct o2net_msg_handler *nmh)
+{
+ kref_put(&nmh->nh_kref, o2net_handler_kref_release);
+}
+
+/* max_len is protection for the handler func. incoming messages won't
+ * be given to the handler if their payload is longer than the max. */
+int o2net_register_handler(u32 msg_type, u32 key, u32 max_len,
+ o2net_msg_handler_func *func, void *data,
+ o2net_post_msg_handler_func *post_func,
+ struct list_head *unreg_list)
+{
+ struct o2net_msg_handler *nmh = NULL;
+ struct rb_node **p, *parent;
+ int ret = 0;
+
+ if (max_len > O2NET_MAX_PAYLOAD_BYTES) {
+ mlog(0, "max_len for message handler out of range: %u\n",
+ max_len);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (!msg_type) {
+ mlog(0, "no message type provided: %u, %p\n", msg_type, func);
+ ret = -EINVAL;
+ goto out;
+
+ }
+ if (!func) {
+ mlog(0, "no message handler provided: %u, %p\n",
+ msg_type, func);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ nmh = kzalloc(sizeof(struct o2net_msg_handler), GFP_NOFS);
+ if (nmh == NULL) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ nmh->nh_func = func;
+ nmh->nh_func_data = data;
+ nmh->nh_post_func = post_func;
+ nmh->nh_msg_type = msg_type;
+ nmh->nh_max_len = max_len;
+ nmh->nh_key = key;
+ /* the tree and list get this ref.. they're both removed in
+ * unregister when this ref is dropped */
+ kref_init(&nmh->nh_kref);
+ INIT_LIST_HEAD(&nmh->nh_unregister_item);
+
+ write_lock(&o2net_handler_lock);
+ if (o2net_handler_tree_lookup(msg_type, key, &p, &parent))
+ ret = -EEXIST;
+ else {
+ rb_link_node(&nmh->nh_node, parent, p);
+ rb_insert_color(&nmh->nh_node, &o2net_handler_tree);
+ list_add_tail(&nmh->nh_unregister_item, unreg_list);
+
+ mlog(ML_TCP, "registered handler func %p type %u key %08x\n",
+ func, msg_type, key);
+ /* we've had some trouble with handlers seemingly vanishing. */
+ mlog_bug_on_msg(o2net_handler_tree_lookup(msg_type, key, &p,
+ &parent) == NULL,
+ "couldn't find handler we *just* registered "
+ "for type %u key %08x\n", msg_type, key);
+ }
+ write_unlock(&o2net_handler_lock);
+
+out:
+ if (ret)
+ kfree(nmh);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(o2net_register_handler);
+
+void o2net_unregister_handler_list(struct list_head *list)
+{
+ struct o2net_msg_handler *nmh, *n;
+
+ write_lock(&o2net_handler_lock);
+ list_for_each_entry_safe(nmh, n, list, nh_unregister_item) {
+ mlog(ML_TCP, "unregistering handler func %p type %u key %08x\n",
+ nmh->nh_func, nmh->nh_msg_type, nmh->nh_key);
+ rb_erase(&nmh->nh_node, &o2net_handler_tree);
+ list_del_init(&nmh->nh_unregister_item);
+ kref_put(&nmh->nh_kref, o2net_handler_kref_release);
+ }
+ write_unlock(&o2net_handler_lock);
+}
+EXPORT_SYMBOL_GPL(o2net_unregister_handler_list);
+
+static struct o2net_msg_handler *o2net_handler_get(u32 msg_type, u32 key)
+{
+ struct o2net_msg_handler *nmh;
+
+ read_lock(&o2net_handler_lock);
+ nmh = o2net_handler_tree_lookup(msg_type, key, NULL, NULL);
+ if (nmh)
+ kref_get(&nmh->nh_kref);
+ read_unlock(&o2net_handler_lock);
+
+ return nmh;
+}
+
+/* ------------------------------------------------------------ */
+
+static int o2net_recv_tcp_msg(struct socket *sock, void *data, size_t len)
+{
+ struct kvec vec = { .iov_len = len, .iov_base = data, };
+ struct msghdr msg = { .msg_flags = MSG_DONTWAIT, };
+ iov_iter_kvec(&msg.msg_iter, READ | ITER_KVEC, &vec, 1, len);
+ return sock_recvmsg(sock, &msg, MSG_DONTWAIT);
+}
+
+static int o2net_send_tcp_msg(struct socket *sock, struct kvec *vec,
+ size_t veclen, size_t total)
+{
+ int ret;
+ struct msghdr msg = {.msg_flags = 0,};
+
+ if (sock == NULL) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = kernel_sendmsg(sock, &msg, vec, veclen, total);
+ if (likely(ret == total))
+ return 0;
+ mlog(ML_ERROR, "sendmsg returned %d instead of %zu\n", ret, total);
+ if (ret >= 0)
+ ret = -EPIPE; /* should be smarter, I bet */
+out:
+ mlog(0, "returning error: %d\n", ret);
+ return ret;
+}
+
+static void o2net_sendpage(struct o2net_sock_container *sc,
+ void *kmalloced_virt,
+ size_t size)
+{
+ struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
+ ssize_t ret;
+
+ while (1) {
+ mutex_lock(&sc->sc_send_lock);
+ ret = sc->sc_sock->ops->sendpage(sc->sc_sock,
+ virt_to_page(kmalloced_virt),
+ offset_in_page(kmalloced_virt),
+ size, MSG_DONTWAIT);
+ mutex_unlock(&sc->sc_send_lock);
+ if (ret == size)
+ break;
+ if (ret == (ssize_t)-EAGAIN) {
+ mlog(0, "sendpage of size %zu to " SC_NODEF_FMT
+ " returned EAGAIN\n", size, SC_NODEF_ARGS(sc));
+ cond_resched();
+ continue;
+ }
+ mlog(ML_ERROR, "sendpage of size %zu to " SC_NODEF_FMT
+ " failed with %zd\n", size, SC_NODEF_ARGS(sc), ret);
+ o2net_ensure_shutdown(nn, sc, 0);
+ break;
+ }
+}
+
+static void o2net_init_msg(struct o2net_msg *msg, u16 data_len, u16 msg_type, u32 key)
+{
+ memset(msg, 0, sizeof(struct o2net_msg));
+ msg->magic = cpu_to_be16(O2NET_MSG_MAGIC);
+ msg->data_len = cpu_to_be16(data_len);
+ msg->msg_type = cpu_to_be16(msg_type);
+ msg->sys_status = cpu_to_be32(O2NET_ERR_NONE);
+ msg->status = 0;
+ msg->key = cpu_to_be32(key);
+}
+
+static int o2net_tx_can_proceed(struct o2net_node *nn,
+ struct o2net_sock_container **sc_ret,
+ int *error)
+{
+ int ret = 0;
+
+ spin_lock(&nn->nn_lock);
+ if (nn->nn_persistent_error) {
+ ret = 1;
+ *sc_ret = NULL;
+ *error = nn->nn_persistent_error;
+ } else if (nn->nn_sc_valid) {
+ kref_get(&nn->nn_sc->sc_kref);
+
+ ret = 1;
+ *sc_ret = nn->nn_sc;
+ *error = 0;
+ }
+ spin_unlock(&nn->nn_lock);
+
+ return ret;
+}
+
+/* Get a map of all nodes to which this node is currently connected to */
+void o2net_fill_node_map(unsigned long *map, unsigned bytes)
+{
+ struct o2net_sock_container *sc;
+ int node, ret;
+
+ BUG_ON(bytes < (BITS_TO_LONGS(O2NM_MAX_NODES) * sizeof(unsigned long)));
+
+ memset(map, 0, bytes);
+ for (node = 0; node < O2NM_MAX_NODES; ++node) {
+ if (!o2net_tx_can_proceed(o2net_nn_from_num(node), &sc, &ret))
+ continue;
+ if (!ret) {
+ set_bit(node, map);
+ sc_put(sc);
+ }
+ }
+}
+EXPORT_SYMBOL_GPL(o2net_fill_node_map);
+
+int o2net_send_message_vec(u32 msg_type, u32 key, struct kvec *caller_vec,
+ size_t caller_veclen, u8 target_node, int *status)
+{
+ int ret = 0;
+ struct o2net_msg *msg = NULL;
+ size_t veclen, caller_bytes = 0;
+ struct kvec *vec = NULL;
+ struct o2net_sock_container *sc = NULL;
+ struct o2net_node *nn = o2net_nn_from_num(target_node);
+ struct o2net_status_wait nsw = {
+ .ns_node_item = LIST_HEAD_INIT(nsw.ns_node_item),
+ };
+ struct o2net_send_tracking nst;
+
+ o2net_init_nst(&nst, msg_type, key, current, target_node);
+
+ if (o2net_wq == NULL) {
+ mlog(0, "attempt to tx without o2netd running\n");
+ ret = -ESRCH;
+ goto out;
+ }
+
+ if (caller_veclen == 0) {
+ mlog(0, "bad kvec array length\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+ caller_bytes = iov_length((struct iovec *)caller_vec, caller_veclen);
+ if (caller_bytes > O2NET_MAX_PAYLOAD_BYTES) {
+ mlog(0, "total payload len %zu too large\n", caller_bytes);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (target_node == o2nm_this_node()) {
+ ret = -ELOOP;
+ goto out;
+ }
+
+ o2net_debug_add_nst(&nst);
+
+ o2net_set_nst_sock_time(&nst);
+
+ wait_event(nn->nn_sc_wq, o2net_tx_can_proceed(nn, &sc, &ret));
+ if (ret)
+ goto out;
+
+ o2net_set_nst_sock_container(&nst, sc);
+
+ veclen = caller_veclen + 1;
+ vec = kmalloc_array(veclen, sizeof(struct kvec), GFP_ATOMIC);
+ if (vec == NULL) {
+ mlog(0, "failed to %zu element kvec!\n", veclen);
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ msg = kmalloc(sizeof(struct o2net_msg), GFP_ATOMIC);
+ if (!msg) {
+ mlog(0, "failed to allocate a o2net_msg!\n");
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ o2net_init_msg(msg, caller_bytes, msg_type, key);
+
+ vec[0].iov_len = sizeof(struct o2net_msg);
+ vec[0].iov_base = msg;
+ memcpy(&vec[1], caller_vec, caller_veclen * sizeof(struct kvec));
+
+ ret = o2net_prep_nsw(nn, &nsw);
+ if (ret)
+ goto out;
+
+ msg->msg_num = cpu_to_be32(nsw.ns_id);
+ o2net_set_nst_msg_id(&nst, nsw.ns_id);
+
+ o2net_set_nst_send_time(&nst);
+
+ /* finally, convert the message header to network byte-order
+ * and send */
+ mutex_lock(&sc->sc_send_lock);
+ ret = o2net_send_tcp_msg(sc->sc_sock, vec, veclen,
+ sizeof(struct o2net_msg) + caller_bytes);
+ mutex_unlock(&sc->sc_send_lock);
+ msglog(msg, "sending returned %d\n", ret);
+ if (ret < 0) {
+ mlog(0, "error returned from o2net_send_tcp_msg=%d\n", ret);
+ goto out;
+ }
+
+ /* wait on other node's handler */
+ o2net_set_nst_status_time(&nst);
+ wait_event(nsw.ns_wq, o2net_nsw_completed(nn, &nsw));
+
+ o2net_update_send_stats(&nst, sc);
+
+ /* Note that we avoid overwriting the callers status return
+ * variable if a system error was reported on the other
+ * side. Callers beware. */
+ ret = o2net_sys_err_to_errno(nsw.ns_sys_status);
+ if (status && !ret)
+ *status = nsw.ns_status;
+
+ mlog(0, "woken, returning system status %d, user status %d\n",
+ ret, nsw.ns_status);
+out:
+ o2net_debug_del_nst(&nst); /* must be before dropping sc and node */
+ if (sc)
+ sc_put(sc);
+ kfree(vec);
+ kfree(msg);
+ o2net_complete_nsw(nn, &nsw, 0, 0, 0);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(o2net_send_message_vec);
+
+int o2net_send_message(u32 msg_type, u32 key, void *data, u32 len,
+ u8 target_node, int *status)
+{
+ struct kvec vec = {
+ .iov_base = data,
+ .iov_len = len,
+ };
+ return o2net_send_message_vec(msg_type, key, &vec, 1,
+ target_node, status);
+}
+EXPORT_SYMBOL_GPL(o2net_send_message);
+
+static int o2net_send_status_magic(struct socket *sock, struct o2net_msg *hdr,
+ enum o2net_system_error syserr, int err)
+{
+ struct kvec vec = {
+ .iov_base = hdr,
+ .iov_len = sizeof(struct o2net_msg),
+ };
+
+ BUG_ON(syserr >= O2NET_ERR_MAX);
+
+ /* leave other fields intact from the incoming message, msg_num
+ * in particular */
+ hdr->sys_status = cpu_to_be32(syserr);
+ hdr->status = cpu_to_be32(err);
+ hdr->magic = cpu_to_be16(O2NET_MSG_STATUS_MAGIC); // twiddle the magic
+ hdr->data_len = 0;
+
+ msglog(hdr, "about to send status magic %d\n", err);
+ /* hdr has been in host byteorder this whole time */
+ return o2net_send_tcp_msg(sock, &vec, 1, sizeof(struct o2net_msg));
+}
+
+/* this returns -errno if the header was unknown or too large, etc.
+ * after this is called the buffer us reused for the next message */
+static int o2net_process_message(struct o2net_sock_container *sc,
+ struct o2net_msg *hdr)
+{
+ struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
+ int ret = 0, handler_status;
+ enum o2net_system_error syserr;
+ struct o2net_msg_handler *nmh = NULL;
+ void *ret_data = NULL;
+
+ msglog(hdr, "processing message\n");
+
+ o2net_sc_postpone_idle(sc);
+
+ switch(be16_to_cpu(hdr->magic)) {
+ case O2NET_MSG_STATUS_MAGIC:
+ /* special type for returning message status */
+ o2net_complete_nsw(nn, NULL,
+ be32_to_cpu(hdr->msg_num),
+ be32_to_cpu(hdr->sys_status),
+ be32_to_cpu(hdr->status));
+ goto out;
+ case O2NET_MSG_KEEP_REQ_MAGIC:
+ o2net_sendpage(sc, o2net_keep_resp,
+ sizeof(*o2net_keep_resp));
+ goto out;
+ case O2NET_MSG_KEEP_RESP_MAGIC:
+ goto out;
+ case O2NET_MSG_MAGIC:
+ break;
+ default:
+ msglog(hdr, "bad magic\n");
+ ret = -EINVAL;
+ goto out;
+ break;
+ }
+
+ /* find a handler for it */
+ handler_status = 0;
+ nmh = o2net_handler_get(be16_to_cpu(hdr->msg_type),
+ be32_to_cpu(hdr->key));
+ if (!nmh) {
+ mlog(ML_TCP, "couldn't find handler for type %u key %08x\n",
+ be16_to_cpu(hdr->msg_type), be32_to_cpu(hdr->key));
+ syserr = O2NET_ERR_NO_HNDLR;
+ goto out_respond;
+ }
+
+ syserr = O2NET_ERR_NONE;
+
+ if (be16_to_cpu(hdr->data_len) > nmh->nh_max_len)
+ syserr = O2NET_ERR_OVERFLOW;
+
+ if (syserr != O2NET_ERR_NONE)
+ goto out_respond;
+
+ o2net_set_func_start_time(sc);
+ sc->sc_msg_key = be32_to_cpu(hdr->key);
+ sc->sc_msg_type = be16_to_cpu(hdr->msg_type);
+ handler_status = (nmh->nh_func)(hdr, sizeof(struct o2net_msg) +
+ be16_to_cpu(hdr->data_len),
+ nmh->nh_func_data, &ret_data);
+ o2net_set_func_stop_time(sc);
+
+ o2net_update_recv_stats(sc);
+
+out_respond:
+ /* this destroys the hdr, so don't use it after this */
+ mutex_lock(&sc->sc_send_lock);
+ ret = o2net_send_status_magic(sc->sc_sock, hdr, syserr,
+ handler_status);
+ mutex_unlock(&sc->sc_send_lock);
+ hdr = NULL;
+ mlog(0, "sending handler status %d, syserr %d returned %d\n",
+ handler_status, syserr, ret);
+
+ if (nmh) {
+ BUG_ON(ret_data != NULL && nmh->nh_post_func == NULL);
+ if (nmh->nh_post_func)
+ (nmh->nh_post_func)(handler_status, nmh->nh_func_data,
+ ret_data);
+ }
+
+out:
+ if (nmh)
+ o2net_handler_put(nmh);
+ return ret;
+}
+
+static int o2net_check_handshake(struct o2net_sock_container *sc)
+{
+ struct o2net_handshake *hand = page_address(sc->sc_page);
+ struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
+
+ if (hand->protocol_version != cpu_to_be64(O2NET_PROTOCOL_VERSION)) {
+ printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " Advertised net "
+ "protocol version %llu but %llu is required. "
+ "Disconnecting.\n", SC_NODEF_ARGS(sc),
+ (unsigned long long)be64_to_cpu(hand->protocol_version),
+ O2NET_PROTOCOL_VERSION);
+
+ /* don't bother reconnecting if its the wrong version. */
+ o2net_ensure_shutdown(nn, sc, -ENOTCONN);
+ return -1;
+ }
+
+ /*
+ * Ensure timeouts are consistent with other nodes, otherwise
+ * we can end up with one node thinking that the other must be down,
+ * but isn't. This can ultimately cause corruption.
+ */
+ if (be32_to_cpu(hand->o2net_idle_timeout_ms) !=
+ o2net_idle_timeout()) {
+ printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a network "
+ "idle timeout of %u ms, but we use %u ms locally. "
+ "Disconnecting.\n", SC_NODEF_ARGS(sc),
+ be32_to_cpu(hand->o2net_idle_timeout_ms),
+ o2net_idle_timeout());
+ o2net_ensure_shutdown(nn, sc, -ENOTCONN);
+ return -1;
+ }
+
+ if (be32_to_cpu(hand->o2net_keepalive_delay_ms) !=
+ o2net_keepalive_delay()) {
+ printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a keepalive "
+ "delay of %u ms, but we use %u ms locally. "
+ "Disconnecting.\n", SC_NODEF_ARGS(sc),
+ be32_to_cpu(hand->o2net_keepalive_delay_ms),
+ o2net_keepalive_delay());
+ o2net_ensure_shutdown(nn, sc, -ENOTCONN);
+ return -1;
+ }
+
+ if (be32_to_cpu(hand->o2hb_heartbeat_timeout_ms) !=
+ O2HB_MAX_WRITE_TIMEOUT_MS) {
+ printk(KERN_NOTICE "o2net: " SC_NODEF_FMT " uses a heartbeat "
+ "timeout of %u ms, but we use %u ms locally. "
+ "Disconnecting.\n", SC_NODEF_ARGS(sc),
+ be32_to_cpu(hand->o2hb_heartbeat_timeout_ms),
+ O2HB_MAX_WRITE_TIMEOUT_MS);
+ o2net_ensure_shutdown(nn, sc, -ENOTCONN);
+ return -1;
+ }
+
+ sc->sc_handshake_ok = 1;
+
+ spin_lock(&nn->nn_lock);
+ /* set valid and queue the idle timers only if it hasn't been
+ * shut down already */
+ if (nn->nn_sc == sc) {
+ o2net_sc_reset_idle_timer(sc);
+ atomic_set(&nn->nn_timeout, 0);
+ o2net_set_nn_state(nn, sc, 1, 0);
+ }
+ spin_unlock(&nn->nn_lock);
+
+ /* shift everything up as though it wasn't there */
+ sc->sc_page_off -= sizeof(struct o2net_handshake);
+ if (sc->sc_page_off)
+ memmove(hand, hand + 1, sc->sc_page_off);
+
+ return 0;
+}
+
+/* this demuxes the queued rx bytes into header or payload bits and calls
+ * handlers as each full message is read off the socket. it returns -error,
+ * == 0 eof, or > 0 for progress made.*/
+static int o2net_advance_rx(struct o2net_sock_container *sc)
+{
+ struct o2net_msg *hdr;
+ int ret = 0;
+ void *data;
+ size_t datalen;
+
+ sclog(sc, "receiving\n");
+ o2net_set_advance_start_time(sc);
+
+ if (unlikely(sc->sc_handshake_ok == 0)) {
+ if(sc->sc_page_off < sizeof(struct o2net_handshake)) {
+ data = page_address(sc->sc_page) + sc->sc_page_off;
+ datalen = sizeof(struct o2net_handshake) - sc->sc_page_off;
+ ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
+ if (ret > 0)
+ sc->sc_page_off += ret;
+ }
+
+ if (sc->sc_page_off == sizeof(struct o2net_handshake)) {
+ o2net_check_handshake(sc);
+ if (unlikely(sc->sc_handshake_ok == 0))
+ ret = -EPROTO;
+ }
+ goto out;
+ }
+
+ /* do we need more header? */
+ if (sc->sc_page_off < sizeof(struct o2net_msg)) {
+ data = page_address(sc->sc_page) + sc->sc_page_off;
+ datalen = sizeof(struct o2net_msg) - sc->sc_page_off;
+ ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
+ if (ret > 0) {
+ sc->sc_page_off += ret;
+ /* only swab incoming here.. we can
+ * only get here once as we cross from
+ * being under to over */
+ if (sc->sc_page_off == sizeof(struct o2net_msg)) {
+ hdr = page_address(sc->sc_page);
+ if (be16_to_cpu(hdr->data_len) >
+ O2NET_MAX_PAYLOAD_BYTES)
+ ret = -EOVERFLOW;
+ }
+ }
+ if (ret <= 0)
+ goto out;
+ }
+
+ if (sc->sc_page_off < sizeof(struct o2net_msg)) {
+ /* oof, still don't have a header */
+ goto out;
+ }
+
+ /* this was swabbed above when we first read it */
+ hdr = page_address(sc->sc_page);
+
+ msglog(hdr, "at page_off %zu\n", sc->sc_page_off);
+
+ /* do we need more payload? */
+ if (sc->sc_page_off - sizeof(struct o2net_msg) < be16_to_cpu(hdr->data_len)) {
+ /* need more payload */
+ data = page_address(sc->sc_page) + sc->sc_page_off;
+ datalen = (sizeof(struct o2net_msg) + be16_to_cpu(hdr->data_len)) -
+ sc->sc_page_off;
+ ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
+ if (ret > 0)
+ sc->sc_page_off += ret;
+ if (ret <= 0)
+ goto out;
+ }
+
+ if (sc->sc_page_off - sizeof(struct o2net_msg) == be16_to_cpu(hdr->data_len)) {
+ /* we can only get here once, the first time we read
+ * the payload.. so set ret to progress if the handler
+ * works out. after calling this the message is toast */
+ ret = o2net_process_message(sc, hdr);
+ if (ret == 0)
+ ret = 1;
+ sc->sc_page_off = 0;
+ }
+
+out:
+ sclog(sc, "ret = %d\n", ret);
+ o2net_set_advance_stop_time(sc);
+ return ret;
+}
+
+/* this work func is triggerd by data ready. it reads until it can read no
+ * more. it interprets 0, eof, as fatal. if data_ready hits while we're doing
+ * our work the work struct will be marked and we'll be called again. */
+static void o2net_rx_until_empty(struct work_struct *work)
+{
+ struct o2net_sock_container *sc =
+ container_of(work, struct o2net_sock_container, sc_rx_work);
+ int ret;
+
+ do {
+ ret = o2net_advance_rx(sc);
+ } while (ret > 0);
+
+ if (ret <= 0 && ret != -EAGAIN) {
+ struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
+ sclog(sc, "saw error %d, closing\n", ret);
+ /* not permanent so read failed handshake can retry */
+ o2net_ensure_shutdown(nn, sc, 0);
+ }
+
+ sc_put(sc);
+}
+
+static int o2net_set_nodelay(struct socket *sock)
+{
+ int val = 1;
+
+ return kernel_setsockopt(sock, SOL_TCP, TCP_NODELAY,
+ (void *)&val, sizeof(val));
+}
+
+static int o2net_set_usertimeout(struct socket *sock)
+{
+ int user_timeout = O2NET_TCP_USER_TIMEOUT;
+
+ return kernel_setsockopt(sock, SOL_TCP, TCP_USER_TIMEOUT,
+ (void *)&user_timeout, sizeof(user_timeout));
+}
+
+static void o2net_initialize_handshake(void)
+{
+ o2net_hand->o2hb_heartbeat_timeout_ms = cpu_to_be32(
+ O2HB_MAX_WRITE_TIMEOUT_MS);
+ o2net_hand->o2net_idle_timeout_ms = cpu_to_be32(o2net_idle_timeout());
+ o2net_hand->o2net_keepalive_delay_ms = cpu_to_be32(
+ o2net_keepalive_delay());
+ o2net_hand->o2net_reconnect_delay_ms = cpu_to_be32(
+ o2net_reconnect_delay());
+}
+
+/* ------------------------------------------------------------ */
+
+/* called when a connect completes and after a sock is accepted. the
+ * rx path will see the response and mark the sc valid */
+static void o2net_sc_connect_completed(struct work_struct *work)
+{
+ struct o2net_sock_container *sc =
+ container_of(work, struct o2net_sock_container,
+ sc_connect_work);
+
+ mlog(ML_MSG, "sc sending handshake with ver %llu id %llx\n",
+ (unsigned long long)O2NET_PROTOCOL_VERSION,
+ (unsigned long long)be64_to_cpu(o2net_hand->connector_id));
+
+ o2net_initialize_handshake();
+ o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
+ sc_put(sc);
+}
+
+/* this is called as a work_struct func. */
+static void o2net_sc_send_keep_req(struct work_struct *work)
+{
+ struct o2net_sock_container *sc =
+ container_of(work, struct o2net_sock_container,
+ sc_keepalive_work.work);
+
+ o2net_sendpage(sc, o2net_keep_req, sizeof(*o2net_keep_req));
+ sc_put(sc);
+}
+
+/* socket shutdown does a del_timer_sync against this as it tears down.
+ * we can't start this timer until we've got to the point in sc buildup
+ * where shutdown is going to be involved */
+static void o2net_idle_timer(struct timer_list *t)
+{
+ struct o2net_sock_container *sc = from_timer(sc, t, sc_idle_timeout);
+ struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
+#ifdef CONFIG_DEBUG_FS
+ unsigned long msecs = ktime_to_ms(ktime_get()) -
+ ktime_to_ms(sc->sc_tv_timer);
+#else
+ unsigned long msecs = o2net_idle_timeout();
+#endif
+
+ printk(KERN_NOTICE "o2net: Connection to " SC_NODEF_FMT " has been "
+ "idle for %lu.%lu secs.\n",
+ SC_NODEF_ARGS(sc), msecs / 1000, msecs % 1000);
+
+ /* idle timerout happen, don't shutdown the connection, but
+ * make fence decision. Maybe the connection can recover before
+ * the decision is made.
+ */
+ atomic_set(&nn->nn_timeout, 1);
+ o2quo_conn_err(o2net_num_from_nn(nn));
+ queue_delayed_work(o2net_wq, &nn->nn_still_up,
+ msecs_to_jiffies(O2NET_QUORUM_DELAY_MS));
+
+ o2net_sc_reset_idle_timer(sc);
+
+}
+
+static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc)
+{
+ o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
+ o2net_sc_queue_delayed_work(sc, &sc->sc_keepalive_work,
+ msecs_to_jiffies(o2net_keepalive_delay()));
+ o2net_set_sock_timer(sc);
+ mod_timer(&sc->sc_idle_timeout,
+ jiffies + msecs_to_jiffies(o2net_idle_timeout()));
+}
+
+static void o2net_sc_postpone_idle(struct o2net_sock_container *sc)
+{
+ struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
+
+ /* clear fence decision since the connection recover from timeout*/
+ if (atomic_read(&nn->nn_timeout)) {
+ o2quo_conn_up(o2net_num_from_nn(nn));
+ cancel_delayed_work(&nn->nn_still_up);
+ atomic_set(&nn->nn_timeout, 0);
+ }
+
+ /* Only push out an existing timer */
+ if (timer_pending(&sc->sc_idle_timeout))
+ o2net_sc_reset_idle_timer(sc);
+}
+
+/* this work func is kicked whenever a path sets the nn state which doesn't
+ * have valid set. This includes seeing hb come up, losing a connection,
+ * having a connect attempt fail, etc. This centralizes the logic which decides
+ * if a connect attempt should be made or if we should give up and all future
+ * transmit attempts should fail */
+static void o2net_start_connect(struct work_struct *work)
+{
+ struct o2net_node *nn =
+ container_of(work, struct o2net_node, nn_connect_work.work);
+ struct o2net_sock_container *sc = NULL;
+ struct o2nm_node *node = NULL, *mynode = NULL;
+ struct socket *sock = NULL;
+ struct sockaddr_in myaddr = {0, }, remoteaddr = {0, };
+ int ret = 0, stop;
+ unsigned int timeout;
+ unsigned int noio_flag;
+
+ /*
+ * sock_create allocates the sock with GFP_KERNEL. We must set
+ * per-process flag PF_MEMALLOC_NOIO so that all allocations done
+ * by this process are done as if GFP_NOIO was specified. So we
+ * are not reentering filesystem while doing memory reclaim.
+ */
+ noio_flag = memalloc_noio_save();
+ /* if we're greater we initiate tx, otherwise we accept */
+ if (o2nm_this_node() <= o2net_num_from_nn(nn))
+ goto out;
+
+ /* watch for racing with tearing a node down */
+ node = o2nm_get_node_by_num(o2net_num_from_nn(nn));
+ if (node == NULL)
+ goto out;
+
+ mynode = o2nm_get_node_by_num(o2nm_this_node());
+ if (mynode == NULL)
+ goto out;
+
+ spin_lock(&nn->nn_lock);
+ /*
+ * see if we already have one pending or have given up.
+ * For nn_timeout, it is set when we close the connection
+ * because of the idle time out. So it means that we have
+ * at least connected to that node successfully once,
+ * now try to connect to it again.
+ */
+ timeout = atomic_read(&nn->nn_timeout);
+ stop = (nn->nn_sc ||
+ (nn->nn_persistent_error &&
+ (nn->nn_persistent_error != -ENOTCONN || timeout == 0)));
+ spin_unlock(&nn->nn_lock);
+ if (stop)
+ goto out;
+
+ nn->nn_last_connect_attempt = jiffies;
+
+ sc = sc_alloc(node);
+ if (sc == NULL) {
+ mlog(0, "couldn't allocate sc\n");
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
+ if (ret < 0) {
+ mlog(0, "can't create socket: %d\n", ret);
+ goto out;
+ }
+ sc->sc_sock = sock; /* freed by sc_kref_release */
+
+ sock->sk->sk_allocation = GFP_ATOMIC;
+
+ myaddr.sin_family = AF_INET;
+ myaddr.sin_addr.s_addr = mynode->nd_ipv4_address;
+ myaddr.sin_port = htons(0); /* any port */
+
+ ret = sock->ops->bind(sock, (struct sockaddr *)&myaddr,
+ sizeof(myaddr));
+ if (ret) {
+ mlog(ML_ERROR, "bind failed with %d at address %pI4\n",
+ ret, &mynode->nd_ipv4_address);
+ goto out;
+ }
+
+ ret = o2net_set_nodelay(sc->sc_sock);
+ if (ret) {
+ mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret);
+ goto out;
+ }
+
+ ret = o2net_set_usertimeout(sock);
+ if (ret) {
+ mlog(ML_ERROR, "set TCP_USER_TIMEOUT failed with %d\n", ret);
+ goto out;
+ }
+
+ o2net_register_callbacks(sc->sc_sock->sk, sc);
+
+ spin_lock(&nn->nn_lock);
+ /* handshake completion will set nn->nn_sc_valid */
+ o2net_set_nn_state(nn, sc, 0, 0);
+ spin_unlock(&nn->nn_lock);
+
+ remoteaddr.sin_family = AF_INET;
+ remoteaddr.sin_addr.s_addr = node->nd_ipv4_address;
+ remoteaddr.sin_port = node->nd_ipv4_port;
+
+ ret = sc->sc_sock->ops->connect(sc->sc_sock,
+ (struct sockaddr *)&remoteaddr,
+ sizeof(remoteaddr),
+ O_NONBLOCK);
+ if (ret == -EINPROGRESS)
+ ret = 0;
+
+out:
+ if (ret && sc) {
+ printk(KERN_NOTICE "o2net: Connect attempt to " SC_NODEF_FMT
+ " failed with errno %d\n", SC_NODEF_ARGS(sc), ret);
+ /* 0 err so that another will be queued and attempted
+ * from set_nn_state */
+ o2net_ensure_shutdown(nn, sc, 0);
+ }
+ if (sc)
+ sc_put(sc);
+ if (node)
+ o2nm_node_put(node);
+ if (mynode)
+ o2nm_node_put(mynode);
+
+ memalloc_noio_restore(noio_flag);
+ return;
+}
+
+static void o2net_connect_expired(struct work_struct *work)
+{
+ struct o2net_node *nn =
+ container_of(work, struct o2net_node, nn_connect_expired.work);
+
+ spin_lock(&nn->nn_lock);
+ if (!nn->nn_sc_valid) {
+ printk(KERN_NOTICE "o2net: No connection established with "
+ "node %u after %u.%u seconds, check network and"
+ " cluster configuration.\n",
+ o2net_num_from_nn(nn),
+ o2net_idle_timeout() / 1000,
+ o2net_idle_timeout() % 1000);
+
+ o2net_set_nn_state(nn, NULL, 0, 0);
+ }
+ spin_unlock(&nn->nn_lock);
+}
+
+static void o2net_still_up(struct work_struct *work)
+{
+ struct o2net_node *nn =
+ container_of(work, struct o2net_node, nn_still_up.work);
+
+ o2quo_hb_still_up(o2net_num_from_nn(nn));
+}
+
+/* ------------------------------------------------------------ */
+
+void o2net_disconnect_node(struct o2nm_node *node)
+{
+ struct o2net_node *nn = o2net_nn_from_num(node->nd_num);
+
+ /* don't reconnect until it's heartbeating again */
+ spin_lock(&nn->nn_lock);
+ atomic_set(&nn->nn_timeout, 0);
+ o2net_set_nn_state(nn, NULL, 0, -ENOTCONN);
+ spin_unlock(&nn->nn_lock);
+
+ if (o2net_wq) {
+ cancel_delayed_work(&nn->nn_connect_expired);
+ cancel_delayed_work(&nn->nn_connect_work);
+ cancel_delayed_work(&nn->nn_still_up);
+ flush_workqueue(o2net_wq);
+ }
+}
+
+static void o2net_hb_node_down_cb(struct o2nm_node *node, int node_num,
+ void *data)
+{
+ o2quo_hb_down(node_num);
+
+ if (!node)
+ return;
+
+ if (node_num != o2nm_this_node())
+ o2net_disconnect_node(node);
+
+ BUG_ON(atomic_read(&o2net_connected_peers) < 0);
+}
+
+static void o2net_hb_node_up_cb(struct o2nm_node *node, int node_num,
+ void *data)
+{
+ struct o2net_node *nn = o2net_nn_from_num(node_num);
+
+ o2quo_hb_up(node_num);
+
+ BUG_ON(!node);
+
+ /* ensure an immediate connect attempt */
+ nn->nn_last_connect_attempt = jiffies -
+ (msecs_to_jiffies(o2net_reconnect_delay()) + 1);
+
+ if (node_num != o2nm_this_node()) {
+ /* believe it or not, accept and node hearbeating testing
+ * can succeed for this node before we got here.. so
+ * only use set_nn_state to clear the persistent error
+ * if that hasn't already happened */
+ spin_lock(&nn->nn_lock);
+ atomic_set(&nn->nn_timeout, 0);
+ if (nn->nn_persistent_error)
+ o2net_set_nn_state(nn, NULL, 0, 0);
+ spin_unlock(&nn->nn_lock);
+ }
+}
+
+void o2net_unregister_hb_callbacks(void)
+{
+ o2hb_unregister_callback(NULL, &o2net_hb_up);
+ o2hb_unregister_callback(NULL, &o2net_hb_down);
+}
+
+int o2net_register_hb_callbacks(void)
+{
+ int ret;
+
+ o2hb_setup_callback(&o2net_hb_down, O2HB_NODE_DOWN_CB,
+ o2net_hb_node_down_cb, NULL, O2NET_HB_PRI);
+ o2hb_setup_callback(&o2net_hb_up, O2HB_NODE_UP_CB,
+ o2net_hb_node_up_cb, NULL, O2NET_HB_PRI);
+
+ ret = o2hb_register_callback(NULL, &o2net_hb_up);
+ if (ret == 0)
+ ret = o2hb_register_callback(NULL, &o2net_hb_down);
+
+ if (ret)
+ o2net_unregister_hb_callbacks();
+
+ return ret;
+}
+
+/* ------------------------------------------------------------ */
+
+static int o2net_accept_one(struct socket *sock, int *more)
+{
+ int ret;
+ struct sockaddr_in sin;
+ struct socket *new_sock = NULL;
+ struct o2nm_node *node = NULL;
+ struct o2nm_node *local_node = NULL;
+ struct o2net_sock_container *sc = NULL;
+ struct o2net_node *nn;
+ unsigned int noio_flag;
+
+ /*
+ * sock_create_lite allocates the sock with GFP_KERNEL. We must set
+ * per-process flag PF_MEMALLOC_NOIO so that all allocations done
+ * by this process are done as if GFP_NOIO was specified. So we
+ * are not reentering filesystem while doing memory reclaim.
+ */
+ noio_flag = memalloc_noio_save();
+
+ BUG_ON(sock == NULL);
+ *more = 0;
+ ret = sock_create_lite(sock->sk->sk_family, sock->sk->sk_type,
+ sock->sk->sk_protocol, &new_sock);
+ if (ret)
+ goto out;
+
+ new_sock->type = sock->type;
+ new_sock->ops = sock->ops;
+ ret = sock->ops->accept(sock, new_sock, O_NONBLOCK, false);
+ if (ret < 0)
+ goto out;
+
+ *more = 1;
+ new_sock->sk->sk_allocation = GFP_ATOMIC;
+
+ ret = o2net_set_nodelay(new_sock);
+ if (ret) {
+ mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret);
+ goto out;
+ }
+
+ ret = o2net_set_usertimeout(new_sock);
+ if (ret) {
+ mlog(ML_ERROR, "set TCP_USER_TIMEOUT failed with %d\n", ret);
+ goto out;
+ }
+
+ ret = new_sock->ops->getname(new_sock, (struct sockaddr *) &sin, 1);
+ if (ret < 0)
+ goto out;
+
+ node = o2nm_get_node_by_ip(sin.sin_addr.s_addr);
+ if (node == NULL) {
+ printk(KERN_NOTICE "o2net: Attempt to connect from unknown "
+ "node at %pI4:%d\n", &sin.sin_addr.s_addr,
+ ntohs(sin.sin_port));
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (o2nm_this_node() >= node->nd_num) {
+ local_node = o2nm_get_node_by_num(o2nm_this_node());
+ if (local_node)
+ printk(KERN_NOTICE "o2net: Unexpected connect attempt "
+ "seen at node '%s' (%u, %pI4:%d) from "
+ "node '%s' (%u, %pI4:%d)\n",
+ local_node->nd_name, local_node->nd_num,
+ &(local_node->nd_ipv4_address),
+ ntohs(local_node->nd_ipv4_port),
+ node->nd_name,
+ node->nd_num, &sin.sin_addr.s_addr,
+ ntohs(sin.sin_port));
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* this happens all the time when the other node sees our heartbeat
+ * and tries to connect before we see their heartbeat */
+ if (!o2hb_check_node_heartbeating_from_callback(node->nd_num)) {
+ mlog(ML_CONN, "attempt to connect from node '%s' at "
+ "%pI4:%d but it isn't heartbeating\n",
+ node->nd_name, &sin.sin_addr.s_addr,
+ ntohs(sin.sin_port));
+ ret = -EINVAL;
+ goto out;
+ }
+
+ nn = o2net_nn_from_num(node->nd_num);
+
+ spin_lock(&nn->nn_lock);
+ if (nn->nn_sc)
+ ret = -EBUSY;
+ else
+ ret = 0;
+ spin_unlock(&nn->nn_lock);
+ if (ret) {
+ printk(KERN_NOTICE "o2net: Attempt to connect from node '%s' "
+ "at %pI4:%d but it already has an open connection\n",
+ node->nd_name, &sin.sin_addr.s_addr,
+ ntohs(sin.sin_port));
+ goto out;
+ }
+
+ sc = sc_alloc(node);
+ if (sc == NULL) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ sc->sc_sock = new_sock;
+ new_sock = NULL;
+
+ spin_lock(&nn->nn_lock);
+ atomic_set(&nn->nn_timeout, 0);
+ o2net_set_nn_state(nn, sc, 0, 0);
+ spin_unlock(&nn->nn_lock);
+
+ o2net_register_callbacks(sc->sc_sock->sk, sc);
+ o2net_sc_queue_work(sc, &sc->sc_rx_work);
+
+ o2net_initialize_handshake();
+ o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
+
+out:
+ if (new_sock)
+ sock_release(new_sock);
+ if (node)
+ o2nm_node_put(node);
+ if (local_node)
+ o2nm_node_put(local_node);
+ if (sc)
+ sc_put(sc);
+
+ memalloc_noio_restore(noio_flag);
+ return ret;
+}
+
+/*
+ * This function is invoked in response to one or more
+ * pending accepts at softIRQ level. We must drain the
+ * entire que before returning.
+ */
+
+static void o2net_accept_many(struct work_struct *work)
+{
+ struct socket *sock = o2net_listen_sock;
+ int more;
+ int err;
+
+ /*
+ * It is critical to note that due to interrupt moderation
+ * at the network driver level, we can't assume to get a
+ * softIRQ for every single conn since tcp SYN packets
+ * can arrive back-to-back, and therefore many pending
+ * accepts may result in just 1 softIRQ. If we terminate
+ * the o2net_accept_one() loop upon seeing an err, what happens
+ * to the rest of the conns in the queue? If no new SYN
+ * arrives for hours, no softIRQ will be delivered,
+ * and the connections will just sit in the queue.
+ */
+
+ for (;;) {
+ err = o2net_accept_one(sock, &more);
+ if (!more)
+ break;
+ cond_resched();
+ }
+}
+
+static void o2net_listen_data_ready(struct sock *sk)
+{
+ void (*ready)(struct sock *sk);
+
+ read_lock_bh(&sk->sk_callback_lock);
+ ready = sk->sk_user_data;
+ if (ready == NULL) { /* check for teardown race */
+ ready = sk->sk_data_ready;
+ goto out;
+ }
+
+ /* This callback may called twice when a new connection
+ * is being established as a child socket inherits everything
+ * from a parent LISTEN socket, including the data_ready cb of
+ * the parent. This leads to a hazard. In o2net_accept_one()
+ * we are still initializing the child socket but have not
+ * changed the inherited data_ready callback yet when
+ * data starts arriving.
+ * We avoid this hazard by checking the state.
+ * For the listening socket, the state will be TCP_LISTEN; for the new
+ * socket, will be TCP_ESTABLISHED. Also, in this case,
+ * sk->sk_user_data is not a valid function pointer.
+ */
+
+ if (sk->sk_state == TCP_LISTEN) {
+ queue_work(o2net_wq, &o2net_listen_work);
+ } else {
+ ready = NULL;
+ }
+
+out:
+ read_unlock_bh(&sk->sk_callback_lock);
+ if (ready != NULL)
+ ready(sk);
+}
+
+static int o2net_open_listening_sock(__be32 addr, __be16 port)
+{
+ struct socket *sock = NULL;
+ int ret;
+ struct sockaddr_in sin = {
+ .sin_family = PF_INET,
+ .sin_addr = { .s_addr = addr },
+ .sin_port = port,
+ };
+
+ ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
+ if (ret < 0) {
+ printk(KERN_ERR "o2net: Error %d while creating socket\n", ret);
+ goto out;
+ }
+
+ sock->sk->sk_allocation = GFP_ATOMIC;
+
+ write_lock_bh(&sock->sk->sk_callback_lock);
+ sock->sk->sk_user_data = sock->sk->sk_data_ready;
+ sock->sk->sk_data_ready = o2net_listen_data_ready;
+ write_unlock_bh(&sock->sk->sk_callback_lock);
+
+ o2net_listen_sock = sock;
+ INIT_WORK(&o2net_listen_work, o2net_accept_many);
+
+ sock->sk->sk_reuse = SK_CAN_REUSE;
+ ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
+ if (ret < 0) {
+ printk(KERN_ERR "o2net: Error %d while binding socket at "
+ "%pI4:%u\n", ret, &addr, ntohs(port));
+ goto out;
+ }
+
+ ret = sock->ops->listen(sock, 64);
+ if (ret < 0)
+ printk(KERN_ERR "o2net: Error %d while listening on %pI4:%u\n",
+ ret, &addr, ntohs(port));
+
+out:
+ if (ret) {
+ o2net_listen_sock = NULL;
+ if (sock)
+ sock_release(sock);
+ }
+ return ret;
+}
+
+/*
+ * called from node manager when we should bring up our network listening
+ * socket. node manager handles all the serialization to only call this
+ * once and to match it with o2net_stop_listening(). note,
+ * o2nm_this_node() doesn't work yet as we're being called while it
+ * is being set up.
+ */
+int o2net_start_listening(struct o2nm_node *node)
+{
+ int ret = 0;
+
+ BUG_ON(o2net_wq != NULL);
+ BUG_ON(o2net_listen_sock != NULL);
+
+ mlog(ML_KTHREAD, "starting o2net thread...\n");
+ o2net_wq = alloc_ordered_workqueue("o2net", WQ_MEM_RECLAIM);
+ if (o2net_wq == NULL) {
+ mlog(ML_ERROR, "unable to launch o2net thread\n");
+ return -ENOMEM; /* ? */
+ }
+
+ ret = o2net_open_listening_sock(node->nd_ipv4_address,
+ node->nd_ipv4_port);
+ if (ret) {
+ destroy_workqueue(o2net_wq);
+ o2net_wq = NULL;
+ } else
+ o2quo_conn_up(node->nd_num);
+
+ return ret;
+}
+
+/* again, o2nm_this_node() doesn't work here as we're involved in
+ * tearing it down */
+void o2net_stop_listening(struct o2nm_node *node)
+{
+ struct socket *sock = o2net_listen_sock;
+ size_t i;
+
+ BUG_ON(o2net_wq == NULL);
+ BUG_ON(o2net_listen_sock == NULL);
+
+ /* stop the listening socket from generating work */
+ write_lock_bh(&sock->sk->sk_callback_lock);
+ sock->sk->sk_data_ready = sock->sk->sk_user_data;
+ sock->sk->sk_user_data = NULL;
+ write_unlock_bh(&sock->sk->sk_callback_lock);
+
+ for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
+ struct o2nm_node *node = o2nm_get_node_by_num(i);
+ if (node) {
+ o2net_disconnect_node(node);
+ o2nm_node_put(node);
+ }
+ }
+
+ /* finish all work and tear down the work queue */
+ mlog(ML_KTHREAD, "waiting for o2net thread to exit....\n");
+ destroy_workqueue(o2net_wq);
+ o2net_wq = NULL;
+
+ sock_release(o2net_listen_sock);
+ o2net_listen_sock = NULL;
+
+ o2quo_conn_err(node->nd_num);
+}
+
+/* ------------------------------------------------------------ */
+
+int o2net_init(void)
+{
+ unsigned long i;
+
+ o2quo_init();
+
+ if (o2net_debugfs_init())
+ goto out;
+
+ o2net_hand = kzalloc(sizeof(struct o2net_handshake), GFP_KERNEL);
+ o2net_keep_req = kzalloc(sizeof(struct o2net_msg), GFP_KERNEL);
+ o2net_keep_resp = kzalloc(sizeof(struct o2net_msg), GFP_KERNEL);
+ if (!o2net_hand || !o2net_keep_req || !o2net_keep_resp)
+ goto out;
+
+ o2net_hand->protocol_version = cpu_to_be64(O2NET_PROTOCOL_VERSION);
+ o2net_hand->connector_id = cpu_to_be64(1);
+
+ o2net_keep_req->magic = cpu_to_be16(O2NET_MSG_KEEP_REQ_MAGIC);
+ o2net_keep_resp->magic = cpu_to_be16(O2NET_MSG_KEEP_RESP_MAGIC);
+
+ for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
+ struct o2net_node *nn = o2net_nn_from_num(i);
+
+ atomic_set(&nn->nn_timeout, 0);
+ spin_lock_init(&nn->nn_lock);
+ INIT_DELAYED_WORK(&nn->nn_connect_work, o2net_start_connect);
+ INIT_DELAYED_WORK(&nn->nn_connect_expired,
+ o2net_connect_expired);
+ INIT_DELAYED_WORK(&nn->nn_still_up, o2net_still_up);
+ /* until we see hb from a node we'll return einval */
+ nn->nn_persistent_error = -ENOTCONN;
+ init_waitqueue_head(&nn->nn_sc_wq);
+ idr_init(&nn->nn_status_idr);
+ INIT_LIST_HEAD(&nn->nn_status_list);
+ }
+
+ return 0;
+
+out:
+ kfree(o2net_hand);
+ kfree(o2net_keep_req);
+ kfree(o2net_keep_resp);
+ o2net_debugfs_exit();
+ o2quo_exit();
+ return -ENOMEM;
+}
+
+void o2net_exit(void)
+{
+ o2quo_exit();
+ kfree(o2net_hand);
+ kfree(o2net_keep_req);
+ kfree(o2net_keep_resp);
+ o2net_debugfs_exit();
+}