Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfashe...
[linux-2.6.git] / fs / ocfs2 / cluster / tcp.c
1 /* -*- mode: c; c-basic-offset: 8; -*-
2  *
3  * vim: noexpandtab sw=8 ts=8 sts=0:
4  *
5  * Copyright (C) 2004 Oracle.  All rights reserved.
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public
9  * License as published by the Free Software Foundation; either
10  * version 2 of the License, or (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public
18  * License along with this program; if not, write to the
19  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
20  * Boston, MA 021110-1307, USA.
21  *
22  * ----
23  *
24  * Callers for this were originally written against a very simple synchronus
25  * API.  This implementation reflects those simple callers.  Some day I'm sure
26  * we'll need to move to a more robust posting/callback mechanism.
27  *
28  * Transmit calls pass in kernel virtual addresses and block copying this into
29  * the socket's tx buffers via a usual blocking sendmsg.  They'll block waiting
30  * for a failed socket to timeout.  TX callers can also pass in a poniter to an
31  * 'int' which gets filled with an errno off the wire in response to the
32  * message they send.
33  *
34  * Handlers for unsolicited messages are registered.  Each socket has a page
35  * that incoming data is copied into.  First the header, then the data.
36  * Handlers are called from only one thread with a reference to this per-socket
37  * page.  This page is destroyed after the handler call, so it can't be
38  * referenced beyond the call.  Handlers may block but are discouraged from
39  * doing so.
40  *
41  * Any framing errors (bad magic, large payload lengths) close a connection.
42  *
43  * Our sock_container holds the state we associate with a socket.  It's current
44  * framing state is held there as well as the refcounting we do around when it
45  * is safe to tear down the socket.  The socket is only finally torn down from
46  * the container when the container loses all of its references -- so as long
47  * as you hold a ref on the container you can trust that the socket is valid
48  * for use with kernel socket APIs.
49  *
50  * Connections are initiated between a pair of nodes when the node with the
51  * higher node number gets a heartbeat callback which indicates that the lower
52  * numbered node has started heartbeating.  The lower numbered node is passive
53  * and only accepts the connection if the higher numbered node is heartbeating.
54  */
55
56 #include <linux/kernel.h>
57 #include <linux/jiffies.h>
58 #include <linux/slab.h>
59 #include <linux/idr.h>
60 #include <linux/kref.h>
61 #include <net/tcp.h>
62
63 #include <asm/uaccess.h>
64
65 #include "heartbeat.h"
66 #include "tcp.h"
67 #include "nodemanager.h"
68 #define MLOG_MASK_PREFIX ML_TCP
69 #include "masklog.h"
70 #include "quorum.h"
71
72 #include "tcp_internal.h"
73
74 /* 
75  * The linux network stack isn't sparse endian clean.. It has macros like
76  * ntohs() which perform the endian checks and structs like sockaddr_in
77  * which aren't annotated.  So __force is found here to get the build
78  * clean.  When they emerge from the dark ages and annotate the code
79  * we can remove these.
80  */
81
82 #define SC_NODEF_FMT "node %s (num %u) at %u.%u.%u.%u:%u"
83 #define SC_NODEF_ARGS(sc) sc->sc_node->nd_name, sc->sc_node->nd_num,    \
84                           NIPQUAD(sc->sc_node->nd_ipv4_address),        \
85                           ntohs(sc->sc_node->nd_ipv4_port)
86
87 /*
88  * In the following two log macros, the whitespace after the ',' just
89  * before ##args is intentional. Otherwise, gcc 2.95 will eat the
90  * previous token if args expands to nothing.
91  */
92 #define msglog(hdr, fmt, args...) do {                                  \
93         typeof(hdr) __hdr = (hdr);                                      \
94         mlog(ML_MSG, "[mag %u len %u typ %u stat %d sys_stat %d "       \
95              "key %08x num %u] " fmt,                                   \
96              be16_to_cpu(__hdr->magic), be16_to_cpu(__hdr->data_len),   \
97              be16_to_cpu(__hdr->msg_type), be32_to_cpu(__hdr->status),  \
98              be32_to_cpu(__hdr->sys_status), be32_to_cpu(__hdr->key),   \
99              be32_to_cpu(__hdr->msg_num) ,  ##args);                    \
100 } while (0)
101
102 #define sclog(sc, fmt, args...) do {                                    \
103         typeof(sc) __sc = (sc);                                         \
104         mlog(ML_SOCKET, "[sc %p refs %d sock %p node %u page %p "       \
105              "pg_off %zu] " fmt, __sc,                                  \
106              atomic_read(&__sc->sc_kref.refcount), __sc->sc_sock,       \
107             __sc->sc_node->nd_num, __sc->sc_page, __sc->sc_page_off ,   \
108             ##args);                                                    \
109 } while (0)
110
111 static DEFINE_RWLOCK(o2net_handler_lock);
112 static struct rb_root o2net_handler_tree = RB_ROOT;
113
114 static struct o2net_node o2net_nodes[O2NM_MAX_NODES];
115
116 /* XXX someday we'll need better accounting */
117 static struct socket *o2net_listen_sock = NULL;
118
119 /*
120  * listen work is only queued by the listening socket callbacks on the
121  * o2net_wq.  teardown detaches the callbacks before destroying the workqueue.
122  * quorum work is queued as sock containers are shutdown.. stop_listening
123  * tears down all the node's sock containers, preventing future shutdowns
124  * and queued quroum work, before canceling delayed quorum work and
125  * destroying the work queue.
126  */
127 static struct workqueue_struct *o2net_wq;
128 static struct work_struct o2net_listen_work;
129
130 static struct o2hb_callback_func o2net_hb_up, o2net_hb_down;
131 #define O2NET_HB_PRI 0x1
132
133 static struct o2net_handshake *o2net_hand;
134 static struct o2net_msg *o2net_keep_req, *o2net_keep_resp;
135
136 static int o2net_sys_err_translations[O2NET_ERR_MAX] =
137                 {[O2NET_ERR_NONE]       = 0,
138                  [O2NET_ERR_NO_HNDLR]   = -ENOPROTOOPT,
139                  [O2NET_ERR_OVERFLOW]   = -EOVERFLOW,
140                  [O2NET_ERR_DIED]       = -EHOSTDOWN,};
141
142 /* can't quite avoid *all* internal declarations :/ */
143 static void o2net_sc_connect_completed(struct work_struct *work);
144 static void o2net_rx_until_empty(struct work_struct *work);
145 static void o2net_shutdown_sc(struct work_struct *work);
146 static void o2net_listen_data_ready(struct sock *sk, int bytes);
147 static void o2net_sc_send_keep_req(struct work_struct *work);
148 static void o2net_idle_timer(unsigned long data);
149 static void o2net_sc_postpone_idle(struct o2net_sock_container *sc);
150 static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc);
151
152 /*
153  * FIXME: These should use to_o2nm_cluster_from_node(), but we end up
154  * losing our parent link to the cluster during shutdown. This can be
155  * solved by adding a pre-removal callback to configfs, or passing
156  * around the cluster with the node. -jeffm
157  */
158 static inline int o2net_reconnect_delay(struct o2nm_node *node)
159 {
160         return o2nm_single_cluster->cl_reconnect_delay_ms;
161 }
162
163 static inline int o2net_keepalive_delay(struct o2nm_node *node)
164 {
165         return o2nm_single_cluster->cl_keepalive_delay_ms;
166 }
167
168 static inline int o2net_idle_timeout(struct o2nm_node *node)
169 {
170         return o2nm_single_cluster->cl_idle_timeout_ms;
171 }
172
173 static inline int o2net_sys_err_to_errno(enum o2net_system_error err)
174 {
175         int trans;
176         BUG_ON(err >= O2NET_ERR_MAX);
177         trans = o2net_sys_err_translations[err];
178
179         /* Just in case we mess up the translation table above */
180         BUG_ON(err != O2NET_ERR_NONE && trans == 0);
181         return trans;
182 }
183
184 static struct o2net_node * o2net_nn_from_num(u8 node_num)
185 {
186         BUG_ON(node_num >= ARRAY_SIZE(o2net_nodes));
187         return &o2net_nodes[node_num];
188 }
189
190 static u8 o2net_num_from_nn(struct o2net_node *nn)
191 {
192         BUG_ON(nn == NULL);
193         return nn - o2net_nodes;
194 }
195
196 /* ------------------------------------------------------------ */
197
198 static int o2net_prep_nsw(struct o2net_node *nn, struct o2net_status_wait *nsw)
199 {
200         int ret = 0;
201
202         do {
203                 if (!idr_pre_get(&nn->nn_status_idr, GFP_ATOMIC)) {
204                         ret = -EAGAIN;
205                         break;
206                 }
207                 spin_lock(&nn->nn_lock);
208                 ret = idr_get_new(&nn->nn_status_idr, nsw, &nsw->ns_id);
209                 if (ret == 0)
210                         list_add_tail(&nsw->ns_node_item,
211                                       &nn->nn_status_list);
212                 spin_unlock(&nn->nn_lock);
213         } while (ret == -EAGAIN);
214
215         if (ret == 0)  {
216                 init_waitqueue_head(&nsw->ns_wq);
217                 nsw->ns_sys_status = O2NET_ERR_NONE;
218                 nsw->ns_status = 0;
219         }
220
221         return ret;
222 }
223
224 static void o2net_complete_nsw_locked(struct o2net_node *nn,
225                                       struct o2net_status_wait *nsw,
226                                       enum o2net_system_error sys_status,
227                                       s32 status)
228 {
229         assert_spin_locked(&nn->nn_lock);
230
231         if (!list_empty(&nsw->ns_node_item)) {
232                 list_del_init(&nsw->ns_node_item);
233                 nsw->ns_sys_status = sys_status;
234                 nsw->ns_status = status;
235                 idr_remove(&nn->nn_status_idr, nsw->ns_id);
236                 wake_up(&nsw->ns_wq);
237         }
238 }
239
240 static void o2net_complete_nsw(struct o2net_node *nn,
241                                struct o2net_status_wait *nsw,
242                                u64 id, enum o2net_system_error sys_status,
243                                s32 status)
244 {
245         spin_lock(&nn->nn_lock);
246         if (nsw == NULL) {
247                 if (id > INT_MAX)
248                         goto out;
249
250                 nsw = idr_find(&nn->nn_status_idr, id);
251                 if (nsw == NULL)
252                         goto out;
253         }
254
255         o2net_complete_nsw_locked(nn, nsw, sys_status, status);
256
257 out:
258         spin_unlock(&nn->nn_lock);
259         return;
260 }
261
262 static void o2net_complete_nodes_nsw(struct o2net_node *nn)
263 {
264         struct list_head *iter, *tmp;
265         unsigned int num_kills = 0;
266         struct o2net_status_wait *nsw;
267
268         assert_spin_locked(&nn->nn_lock);
269
270         list_for_each_safe(iter, tmp, &nn->nn_status_list) {
271                 nsw = list_entry(iter, struct o2net_status_wait, ns_node_item);
272                 o2net_complete_nsw_locked(nn, nsw, O2NET_ERR_DIED, 0);
273                 num_kills++;
274         }
275
276         mlog(0, "completed %d messages for node %u\n", num_kills,
277              o2net_num_from_nn(nn));
278 }
279
280 static int o2net_nsw_completed(struct o2net_node *nn,
281                                struct o2net_status_wait *nsw)
282 {
283         int completed;
284         spin_lock(&nn->nn_lock);
285         completed = list_empty(&nsw->ns_node_item);
286         spin_unlock(&nn->nn_lock);
287         return completed;
288 }
289
290 /* ------------------------------------------------------------ */
291
292 static void sc_kref_release(struct kref *kref)
293 {
294         struct o2net_sock_container *sc = container_of(kref,
295                                         struct o2net_sock_container, sc_kref);
296         BUG_ON(timer_pending(&sc->sc_idle_timeout));
297
298         sclog(sc, "releasing\n");
299
300         if (sc->sc_sock) {
301                 sock_release(sc->sc_sock);
302                 sc->sc_sock = NULL;
303         }
304
305         o2nm_node_put(sc->sc_node);
306         sc->sc_node = NULL;
307
308         kfree(sc);
309 }
310
311 static void sc_put(struct o2net_sock_container *sc)
312 {
313         sclog(sc, "put\n");
314         kref_put(&sc->sc_kref, sc_kref_release);
315 }
316 static void sc_get(struct o2net_sock_container *sc)
317 {
318         sclog(sc, "get\n");
319         kref_get(&sc->sc_kref);
320 }
321 static struct o2net_sock_container *sc_alloc(struct o2nm_node *node)
322 {
323         struct o2net_sock_container *sc, *ret = NULL;
324         struct page *page = NULL;
325
326         page = alloc_page(GFP_NOFS);
327         sc = kcalloc(1, sizeof(*sc), GFP_NOFS);
328         if (sc == NULL || page == NULL)
329                 goto out;
330
331         kref_init(&sc->sc_kref);
332         o2nm_node_get(node);
333         sc->sc_node = node;
334
335         INIT_WORK(&sc->sc_connect_work, o2net_sc_connect_completed);
336         INIT_WORK(&sc->sc_rx_work, o2net_rx_until_empty);
337         INIT_WORK(&sc->sc_shutdown_work, o2net_shutdown_sc);
338         INIT_DELAYED_WORK(&sc->sc_keepalive_work, o2net_sc_send_keep_req);
339
340         init_timer(&sc->sc_idle_timeout);
341         sc->sc_idle_timeout.function = o2net_idle_timer;
342         sc->sc_idle_timeout.data = (unsigned long)sc;
343
344         sclog(sc, "alloced\n");
345
346         ret = sc;
347         sc->sc_page = page;
348         sc = NULL;
349         page = NULL;
350
351 out:
352         if (page)
353                 __free_page(page);
354         kfree(sc);
355
356         return ret;
357 }
358
359 /* ------------------------------------------------------------ */
360
361 static void o2net_sc_queue_work(struct o2net_sock_container *sc,
362                                 struct work_struct *work)
363 {
364         sc_get(sc);
365         if (!queue_work(o2net_wq, work))
366                 sc_put(sc);
367 }
368 static void o2net_sc_queue_delayed_work(struct o2net_sock_container *sc,
369                                         struct delayed_work *work,
370                                         int delay)
371 {
372         sc_get(sc);
373         if (!queue_delayed_work(o2net_wq, work, delay))
374                 sc_put(sc);
375 }
376 static void o2net_sc_cancel_delayed_work(struct o2net_sock_container *sc,
377                                          struct delayed_work *work)
378 {
379         if (cancel_delayed_work(work))
380                 sc_put(sc);
381 }
382
383 static atomic_t o2net_connected_peers = ATOMIC_INIT(0);
384
385 int o2net_num_connected_peers(void)
386 {
387         return atomic_read(&o2net_connected_peers);
388 }
389
390 static void o2net_set_nn_state(struct o2net_node *nn,
391                                struct o2net_sock_container *sc,
392                                unsigned valid, int err)
393 {
394         int was_valid = nn->nn_sc_valid;
395         int was_err = nn->nn_persistent_error;
396         struct o2net_sock_container *old_sc = nn->nn_sc;
397
398         assert_spin_locked(&nn->nn_lock);
399
400         if (old_sc && !sc)
401                 atomic_dec(&o2net_connected_peers);
402         else if (!old_sc && sc)
403                 atomic_inc(&o2net_connected_peers);
404
405         /* the node num comparison and single connect/accept path should stop
406          * an non-null sc from being overwritten with another */
407         BUG_ON(sc && nn->nn_sc && nn->nn_sc != sc);
408         mlog_bug_on_msg(err && valid, "err %d valid %u\n", err, valid);
409         mlog_bug_on_msg(valid && !sc, "valid %u sc %p\n", valid, sc);
410
411         /* we won't reconnect after our valid conn goes away for
412          * this hb iteration.. here so it shows up in the logs */
413         if (was_valid && !valid && err == 0)
414                 err = -ENOTCONN;
415
416         mlog(ML_CONN, "node %u sc: %p -> %p, valid %u -> %u, err %d -> %d\n",
417              o2net_num_from_nn(nn), nn->nn_sc, sc, nn->nn_sc_valid, valid,
418              nn->nn_persistent_error, err);
419
420         nn->nn_sc = sc;
421         nn->nn_sc_valid = valid ? 1 : 0;
422         nn->nn_persistent_error = err;
423
424         /* mirrors o2net_tx_can_proceed() */
425         if (nn->nn_persistent_error || nn->nn_sc_valid)
426                 wake_up(&nn->nn_sc_wq);
427
428         if (!was_err && nn->nn_persistent_error) {
429                 o2quo_conn_err(o2net_num_from_nn(nn));
430                 queue_delayed_work(o2net_wq, &nn->nn_still_up,
431                                    msecs_to_jiffies(O2NET_QUORUM_DELAY_MS));
432         }
433
434         if (was_valid && !valid) {
435                 printk(KERN_INFO "o2net: no longer connected to "
436                        SC_NODEF_FMT "\n", SC_NODEF_ARGS(old_sc));
437                 o2net_complete_nodes_nsw(nn);
438         }
439
440         if (!was_valid && valid) {
441                 o2quo_conn_up(o2net_num_from_nn(nn));
442                 /* this is a bit of a hack.  we only try reconnecting
443                  * when heartbeating starts until we get a connection.
444                  * if that connection then dies we don't try reconnecting.
445                  * the only way to start connecting again is to down
446                  * heartbeat and bring it back up. */
447                 cancel_delayed_work(&nn->nn_connect_expired);
448                 printk(KERN_INFO "o2net: %s " SC_NODEF_FMT "\n",
449                        o2nm_this_node() > sc->sc_node->nd_num ?
450                                 "connected to" : "accepted connection from",
451                        SC_NODEF_ARGS(sc));
452         }
453
454         /* trigger the connecting worker func as long as we're not valid,
455          * it will back off if it shouldn't connect.  This can be called
456          * from node config teardown and so needs to be careful about
457          * the work queue actually being up. */
458         if (!valid && o2net_wq) {
459                 unsigned long delay;
460                 /* delay if we're withing a RECONNECT_DELAY of the
461                  * last attempt */
462                 delay = (nn->nn_last_connect_attempt +
463                          msecs_to_jiffies(o2net_reconnect_delay(sc->sc_node)))
464                         - jiffies;
465                 if (delay > msecs_to_jiffies(o2net_reconnect_delay(sc->sc_node)))
466                         delay = 0;
467                 mlog(ML_CONN, "queueing conn attempt in %lu jiffies\n", delay);
468                 queue_delayed_work(o2net_wq, &nn->nn_connect_work, delay);
469         }
470
471         /* keep track of the nn's sc ref for the caller */
472         if ((old_sc == NULL) && sc)
473                 sc_get(sc);
474         if (old_sc && (old_sc != sc)) {
475                 o2net_sc_queue_work(old_sc, &old_sc->sc_shutdown_work);
476                 sc_put(old_sc);
477         }
478 }
479
480 /* see o2net_register_callbacks() */
481 static void o2net_data_ready(struct sock *sk, int bytes)
482 {
483         void (*ready)(struct sock *sk, int bytes);
484
485         read_lock(&sk->sk_callback_lock);
486         if (sk->sk_user_data) {
487                 struct o2net_sock_container *sc = sk->sk_user_data;
488                 sclog(sc, "data_ready hit\n");
489                 do_gettimeofday(&sc->sc_tv_data_ready);
490                 o2net_sc_queue_work(sc, &sc->sc_rx_work);
491                 ready = sc->sc_data_ready;
492         } else {
493                 ready = sk->sk_data_ready;
494         }
495         read_unlock(&sk->sk_callback_lock);
496
497         ready(sk, bytes);
498 }
499
500 /* see o2net_register_callbacks() */
501 static void o2net_state_change(struct sock *sk)
502 {
503         void (*state_change)(struct sock *sk);
504         struct o2net_sock_container *sc;
505
506         read_lock(&sk->sk_callback_lock);
507         sc = sk->sk_user_data;
508         if (sc == NULL) {
509                 state_change = sk->sk_state_change;
510                 goto out;
511         }
512
513         sclog(sc, "state_change to %d\n", sk->sk_state);
514
515         state_change = sc->sc_state_change;
516
517         switch(sk->sk_state) {
518                 /* ignore connecting sockets as they make progress */
519                 case TCP_SYN_SENT:
520                 case TCP_SYN_RECV:
521                         break;
522                 case TCP_ESTABLISHED:
523                         o2net_sc_queue_work(sc, &sc->sc_connect_work);
524                         break;
525                 default:
526                         o2net_sc_queue_work(sc, &sc->sc_shutdown_work);
527                         break;
528         }
529 out:
530         read_unlock(&sk->sk_callback_lock);
531         state_change(sk);
532 }
533
534 /*
535  * we register callbacks so we can queue work on events before calling
536  * the original callbacks.  our callbacks our careful to test user_data
537  * to discover when they've reaced with o2net_unregister_callbacks().
538  */
539 static void o2net_register_callbacks(struct sock *sk,
540                                      struct o2net_sock_container *sc)
541 {
542         write_lock_bh(&sk->sk_callback_lock);
543
544         /* accepted sockets inherit the old listen socket data ready */
545         if (sk->sk_data_ready == o2net_listen_data_ready) {
546                 sk->sk_data_ready = sk->sk_user_data;
547                 sk->sk_user_data = NULL;
548         }
549
550         BUG_ON(sk->sk_user_data != NULL);
551         sk->sk_user_data = sc;
552         sc_get(sc);
553
554         sc->sc_data_ready = sk->sk_data_ready;
555         sc->sc_state_change = sk->sk_state_change;
556         sk->sk_data_ready = o2net_data_ready;
557         sk->sk_state_change = o2net_state_change;
558
559         write_unlock_bh(&sk->sk_callback_lock);
560 }
561
562 static int o2net_unregister_callbacks(struct sock *sk,
563                                    struct o2net_sock_container *sc)
564 {
565         int ret = 0;
566
567         write_lock_bh(&sk->sk_callback_lock);
568         if (sk->sk_user_data == sc) {
569                 ret = 1;
570                 sk->sk_user_data = NULL;
571                 sk->sk_data_ready = sc->sc_data_ready;
572                 sk->sk_state_change = sc->sc_state_change;
573         }
574         write_unlock_bh(&sk->sk_callback_lock);
575
576         return ret;
577 }
578
579 /*
580  * this is a little helper that is called by callers who have seen a problem
581  * with an sc and want to detach it from the nn if someone already hasn't beat
582  * them to it.  if an error is given then the shutdown will be persistent
583  * and pending transmits will be canceled.
584  */
585 static void o2net_ensure_shutdown(struct o2net_node *nn,
586                                    struct o2net_sock_container *sc,
587                                    int err)
588 {
589         spin_lock(&nn->nn_lock);
590         if (nn->nn_sc == sc)
591                 o2net_set_nn_state(nn, NULL, 0, err);
592         spin_unlock(&nn->nn_lock);
593 }
594
595 /*
596  * This work queue function performs the blocking parts of socket shutdown.  A
597  * few paths lead here.  set_nn_state will trigger this callback if it sees an
598  * sc detached from the nn.  state_change will also trigger this callback
599  * directly when it sees errors.  In that case we need to call set_nn_state
600  * ourselves as state_change couldn't get the nn_lock and call set_nn_state
601  * itself.
602  */
603 static void o2net_shutdown_sc(struct work_struct *work)
604 {
605         struct o2net_sock_container *sc =
606                 container_of(work, struct o2net_sock_container,
607                              sc_shutdown_work);
608         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
609
610         sclog(sc, "shutting down\n");
611
612         /* drop the callbacks ref and call shutdown only once */
613         if (o2net_unregister_callbacks(sc->sc_sock->sk, sc)) {
614                 /* we shouldn't flush as we're in the thread, the
615                  * races with pending sc work structs are harmless */
616                 del_timer_sync(&sc->sc_idle_timeout);
617                 o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
618                 sc_put(sc);
619                 sc->sc_sock->ops->shutdown(sc->sc_sock,
620                                            RCV_SHUTDOWN|SEND_SHUTDOWN);
621         }
622
623         /* not fatal so failed connects before the other guy has our
624          * heartbeat can be retried */
625         o2net_ensure_shutdown(nn, sc, 0);
626         sc_put(sc);
627 }
628
629 /* ------------------------------------------------------------ */
630
631 static int o2net_handler_cmp(struct o2net_msg_handler *nmh, u32 msg_type,
632                              u32 key)
633 {
634         int ret = memcmp(&nmh->nh_key, &key, sizeof(key));
635
636         if (ret == 0)
637                 ret = memcmp(&nmh->nh_msg_type, &msg_type, sizeof(msg_type));
638
639         return ret;
640 }
641
642 static struct o2net_msg_handler *
643 o2net_handler_tree_lookup(u32 msg_type, u32 key, struct rb_node ***ret_p,
644                           struct rb_node **ret_parent)
645 {
646         struct rb_node **p = &o2net_handler_tree.rb_node;
647         struct rb_node *parent = NULL;
648         struct o2net_msg_handler *nmh, *ret = NULL;
649         int cmp;
650
651         while (*p) {
652                 parent = *p;
653                 nmh = rb_entry(parent, struct o2net_msg_handler, nh_node);
654                 cmp = o2net_handler_cmp(nmh, msg_type, key);
655
656                 if (cmp < 0)
657                         p = &(*p)->rb_left;
658                 else if (cmp > 0)
659                         p = &(*p)->rb_right;
660                 else {
661                         ret = nmh;
662                         break;
663                 }
664         }
665
666         if (ret_p != NULL)
667                 *ret_p = p;
668         if (ret_parent != NULL)
669                 *ret_parent = parent;
670
671         return ret;
672 }
673
674 static void o2net_handler_kref_release(struct kref *kref)
675 {
676         struct o2net_msg_handler *nmh;
677         nmh = container_of(kref, struct o2net_msg_handler, nh_kref);
678
679         kfree(nmh);
680 }
681
682 static void o2net_handler_put(struct o2net_msg_handler *nmh)
683 {
684         kref_put(&nmh->nh_kref, o2net_handler_kref_release);
685 }
686
687 /* max_len is protection for the handler func.  incoming messages won't
688  * be given to the handler if their payload is longer than the max. */
689 int o2net_register_handler(u32 msg_type, u32 key, u32 max_len,
690                            o2net_msg_handler_func *func, void *data,
691                            struct list_head *unreg_list)
692 {
693         struct o2net_msg_handler *nmh = NULL;
694         struct rb_node **p, *parent;
695         int ret = 0;
696
697         if (max_len > O2NET_MAX_PAYLOAD_BYTES) {
698                 mlog(0, "max_len for message handler out of range: %u\n",
699                         max_len);
700                 ret = -EINVAL;
701                 goto out;
702         }
703
704         if (!msg_type) {
705                 mlog(0, "no message type provided: %u, %p\n", msg_type, func);
706                 ret = -EINVAL;
707                 goto out;
708
709         }
710         if (!func) {
711                 mlog(0, "no message handler provided: %u, %p\n",
712                        msg_type, func);
713                 ret = -EINVAL;
714                 goto out;
715         }
716
717         nmh = kcalloc(1, sizeof(struct o2net_msg_handler), GFP_NOFS);
718         if (nmh == NULL) {
719                 ret = -ENOMEM;
720                 goto out;
721         }
722
723         nmh->nh_func = func;
724         nmh->nh_func_data = data;
725         nmh->nh_msg_type = msg_type;
726         nmh->nh_max_len = max_len;
727         nmh->nh_key = key;
728         /* the tree and list get this ref.. they're both removed in
729          * unregister when this ref is dropped */
730         kref_init(&nmh->nh_kref);
731         INIT_LIST_HEAD(&nmh->nh_unregister_item);
732
733         write_lock(&o2net_handler_lock);
734         if (o2net_handler_tree_lookup(msg_type, key, &p, &parent))
735                 ret = -EEXIST;
736         else {
737                 rb_link_node(&nmh->nh_node, parent, p);
738                 rb_insert_color(&nmh->nh_node, &o2net_handler_tree);
739                 list_add_tail(&nmh->nh_unregister_item, unreg_list);
740
741                 mlog(ML_TCP, "registered handler func %p type %u key %08x\n",
742                      func, msg_type, key);
743                 /* we've had some trouble with handlers seemingly vanishing. */
744                 mlog_bug_on_msg(o2net_handler_tree_lookup(msg_type, key, &p,
745                                                           &parent) == NULL,
746                                 "couldn't find handler we *just* registerd "
747                                 "for type %u key %08x\n", msg_type, key);
748         }
749         write_unlock(&o2net_handler_lock);
750         if (ret)
751                 goto out;
752
753 out:
754         if (ret)
755                 kfree(nmh);
756
757         return ret;
758 }
759 EXPORT_SYMBOL_GPL(o2net_register_handler);
760
761 void o2net_unregister_handler_list(struct list_head *list)
762 {
763         struct list_head *pos, *n;
764         struct o2net_msg_handler *nmh;
765
766         write_lock(&o2net_handler_lock);
767         list_for_each_safe(pos, n, list) {
768                 nmh = list_entry(pos, struct o2net_msg_handler,
769                                  nh_unregister_item);
770                 mlog(ML_TCP, "unregistering handler func %p type %u key %08x\n",
771                      nmh->nh_func, nmh->nh_msg_type, nmh->nh_key);
772                 rb_erase(&nmh->nh_node, &o2net_handler_tree);
773                 list_del_init(&nmh->nh_unregister_item);
774                 kref_put(&nmh->nh_kref, o2net_handler_kref_release);
775         }
776         write_unlock(&o2net_handler_lock);
777 }
778 EXPORT_SYMBOL_GPL(o2net_unregister_handler_list);
779
780 static struct o2net_msg_handler *o2net_handler_get(u32 msg_type, u32 key)
781 {
782         struct o2net_msg_handler *nmh;
783
784         read_lock(&o2net_handler_lock);
785         nmh = o2net_handler_tree_lookup(msg_type, key, NULL, NULL);
786         if (nmh)
787                 kref_get(&nmh->nh_kref);
788         read_unlock(&o2net_handler_lock);
789
790         return nmh;
791 }
792
793 /* ------------------------------------------------------------ */
794
795 static int o2net_recv_tcp_msg(struct socket *sock, void *data, size_t len)
796 {
797         int ret;
798         mm_segment_t oldfs;
799         struct kvec vec = {
800                 .iov_len = len,
801                 .iov_base = data,
802         };
803         struct msghdr msg = {
804                 .msg_iovlen = 1,
805                 .msg_iov = (struct iovec *)&vec,
806                 .msg_flags = MSG_DONTWAIT,
807         };
808
809         oldfs = get_fs();
810         set_fs(get_ds());
811         ret = sock_recvmsg(sock, &msg, len, msg.msg_flags);
812         set_fs(oldfs);
813
814         return ret;
815 }
816
817 static int o2net_send_tcp_msg(struct socket *sock, struct kvec *vec,
818                               size_t veclen, size_t total)
819 {
820         int ret;
821         mm_segment_t oldfs;
822         struct msghdr msg = {
823                 .msg_iov = (struct iovec *)vec,
824                 .msg_iovlen = veclen,
825         };
826
827         if (sock == NULL) {
828                 ret = -EINVAL;
829                 goto out;
830         }
831
832         oldfs = get_fs();
833         set_fs(get_ds());
834         ret = sock_sendmsg(sock, &msg, total);
835         set_fs(oldfs);
836         if (ret != total) {
837                 mlog(ML_ERROR, "sendmsg returned %d instead of %zu\n", ret,
838                      total);
839                 if (ret >= 0)
840                         ret = -EPIPE; /* should be smarter, I bet */
841                 goto out;
842         }
843
844         ret = 0;
845 out:
846         if (ret < 0)
847                 mlog(0, "returning error: %d\n", ret);
848         return ret;
849 }
850
851 static void o2net_sendpage(struct o2net_sock_container *sc,
852                            void *kmalloced_virt,
853                            size_t size)
854 {
855         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
856         ssize_t ret;
857
858
859         ret = sc->sc_sock->ops->sendpage(sc->sc_sock,
860                                          virt_to_page(kmalloced_virt),
861                                          (long)kmalloced_virt & ~PAGE_MASK,
862                                          size, MSG_DONTWAIT);
863         if (ret != size) {
864                 mlog(ML_ERROR, "sendpage of size %zu to " SC_NODEF_FMT 
865                      " failed with %zd\n", size, SC_NODEF_ARGS(sc), ret);
866                 o2net_ensure_shutdown(nn, sc, 0);
867         }
868 }
869
870 static void o2net_init_msg(struct o2net_msg *msg, u16 data_len, u16 msg_type, u32 key)
871 {
872         memset(msg, 0, sizeof(struct o2net_msg));
873         msg->magic = cpu_to_be16(O2NET_MSG_MAGIC);
874         msg->data_len = cpu_to_be16(data_len);
875         msg->msg_type = cpu_to_be16(msg_type);
876         msg->sys_status = cpu_to_be32(O2NET_ERR_NONE);
877         msg->status = 0;
878         msg->key = cpu_to_be32(key);
879 }
880
881 static int o2net_tx_can_proceed(struct o2net_node *nn,
882                                 struct o2net_sock_container **sc_ret,
883                                 int *error)
884 {
885         int ret = 0;
886
887         spin_lock(&nn->nn_lock);
888         if (nn->nn_persistent_error) {
889                 ret = 1;
890                 *sc_ret = NULL;
891                 *error = nn->nn_persistent_error;
892         } else if (nn->nn_sc_valid) {
893                 kref_get(&nn->nn_sc->sc_kref);
894
895                 ret = 1;
896                 *sc_ret = nn->nn_sc;
897                 *error = 0;
898         }
899         spin_unlock(&nn->nn_lock);
900
901         return ret;
902 }
903
904 int o2net_send_message_vec(u32 msg_type, u32 key, struct kvec *caller_vec,
905                            size_t caller_veclen, u8 target_node, int *status)
906 {
907         int ret, error = 0;
908         struct o2net_msg *msg = NULL;
909         size_t veclen, caller_bytes = 0;
910         struct kvec *vec = NULL;
911         struct o2net_sock_container *sc = NULL;
912         struct o2net_node *nn = o2net_nn_from_num(target_node);
913         struct o2net_status_wait nsw = {
914                 .ns_node_item = LIST_HEAD_INIT(nsw.ns_node_item),
915         };
916
917         if (o2net_wq == NULL) {
918                 mlog(0, "attempt to tx without o2netd running\n");
919                 ret = -ESRCH;
920                 goto out;
921         }
922
923         if (caller_veclen == 0) {
924                 mlog(0, "bad kvec array length\n");
925                 ret = -EINVAL;
926                 goto out;
927         }
928
929         caller_bytes = iov_length((struct iovec *)caller_vec, caller_veclen);
930         if (caller_bytes > O2NET_MAX_PAYLOAD_BYTES) {
931                 mlog(0, "total payload len %zu too large\n", caller_bytes);
932                 ret = -EINVAL;
933                 goto out;
934         }
935
936         if (target_node == o2nm_this_node()) {
937                 ret = -ELOOP;
938                 goto out;
939         }
940
941         ret = wait_event_interruptible(nn->nn_sc_wq,
942                                        o2net_tx_can_proceed(nn, &sc, &error));
943         if (!ret && error)
944                 ret = error;
945         if (ret)
946                 goto out;
947
948         veclen = caller_veclen + 1;
949         vec = kmalloc(sizeof(struct kvec) * veclen, GFP_ATOMIC);
950         if (vec == NULL) {
951                 mlog(0, "failed to %zu element kvec!\n", veclen);
952                 ret = -ENOMEM;
953                 goto out;
954         }
955
956         msg = kmalloc(sizeof(struct o2net_msg), GFP_ATOMIC);
957         if (!msg) {
958                 mlog(0, "failed to allocate a o2net_msg!\n");
959                 ret = -ENOMEM;
960                 goto out;
961         }
962
963         o2net_init_msg(msg, caller_bytes, msg_type, key);
964
965         vec[0].iov_len = sizeof(struct o2net_msg);
966         vec[0].iov_base = msg;
967         memcpy(&vec[1], caller_vec, caller_veclen * sizeof(struct kvec));
968
969         ret = o2net_prep_nsw(nn, &nsw);
970         if (ret)
971                 goto out;
972
973         msg->msg_num = cpu_to_be32(nsw.ns_id);
974
975         /* finally, convert the message header to network byte-order
976          * and send */
977         ret = o2net_send_tcp_msg(sc->sc_sock, vec, veclen,
978                                  sizeof(struct o2net_msg) + caller_bytes);
979         msglog(msg, "sending returned %d\n", ret);
980         if (ret < 0) {
981                 mlog(0, "error returned from o2net_send_tcp_msg=%d\n", ret);
982                 goto out;
983         }
984
985         /* wait on other node's handler */
986         wait_event(nsw.ns_wq, o2net_nsw_completed(nn, &nsw));
987
988         /* Note that we avoid overwriting the callers status return
989          * variable if a system error was reported on the other
990          * side. Callers beware. */
991         ret = o2net_sys_err_to_errno(nsw.ns_sys_status);
992         if (status && !ret)
993                 *status = nsw.ns_status;
994
995         mlog(0, "woken, returning system status %d, user status %d\n",
996              ret, nsw.ns_status);
997 out:
998         if (sc)
999                 sc_put(sc);
1000         if (vec)
1001                 kfree(vec);
1002         if (msg)
1003                 kfree(msg);
1004         o2net_complete_nsw(nn, &nsw, 0, 0, 0);
1005         return ret;
1006 }
1007 EXPORT_SYMBOL_GPL(o2net_send_message_vec);
1008
1009 int o2net_send_message(u32 msg_type, u32 key, void *data, u32 len,
1010                        u8 target_node, int *status)
1011 {
1012         struct kvec vec = {
1013                 .iov_base = data,
1014                 .iov_len = len,
1015         };
1016         return o2net_send_message_vec(msg_type, key, &vec, 1,
1017                                       target_node, status);
1018 }
1019 EXPORT_SYMBOL_GPL(o2net_send_message);
1020
1021 static int o2net_send_status_magic(struct socket *sock, struct o2net_msg *hdr,
1022                                    enum o2net_system_error syserr, int err)
1023 {
1024         struct kvec vec = {
1025                 .iov_base = hdr,
1026                 .iov_len = sizeof(struct o2net_msg),
1027         };
1028
1029         BUG_ON(syserr >= O2NET_ERR_MAX);
1030
1031         /* leave other fields intact from the incoming message, msg_num
1032          * in particular */
1033         hdr->sys_status = cpu_to_be32(syserr);
1034         hdr->status = cpu_to_be32(err);
1035         hdr->magic = cpu_to_be16(O2NET_MSG_STATUS_MAGIC);  // twiddle the magic
1036         hdr->data_len = 0;
1037
1038         msglog(hdr, "about to send status magic %d\n", err);
1039         /* hdr has been in host byteorder this whole time */
1040         return o2net_send_tcp_msg(sock, &vec, 1, sizeof(struct o2net_msg));
1041 }
1042
1043 /* this returns -errno if the header was unknown or too large, etc.
1044  * after this is called the buffer us reused for the next message */
1045 static int o2net_process_message(struct o2net_sock_container *sc,
1046                                  struct o2net_msg *hdr)
1047 {
1048         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1049         int ret = 0, handler_status;
1050         enum  o2net_system_error syserr;
1051         struct o2net_msg_handler *nmh = NULL;
1052
1053         msglog(hdr, "processing message\n");
1054
1055         o2net_sc_postpone_idle(sc);
1056
1057         switch(be16_to_cpu(hdr->magic)) {
1058                 case O2NET_MSG_STATUS_MAGIC:
1059                         /* special type for returning message status */
1060                         o2net_complete_nsw(nn, NULL,
1061                                            be32_to_cpu(hdr->msg_num),
1062                                            be32_to_cpu(hdr->sys_status),
1063                                            be32_to_cpu(hdr->status));
1064                         goto out;
1065                 case O2NET_MSG_KEEP_REQ_MAGIC:
1066                         o2net_sendpage(sc, o2net_keep_resp,
1067                                        sizeof(*o2net_keep_resp));
1068                         goto out;
1069                 case O2NET_MSG_KEEP_RESP_MAGIC:
1070                         goto out;
1071                 case O2NET_MSG_MAGIC:
1072                         break;
1073                 default:
1074                         msglog(hdr, "bad magic\n");
1075                         ret = -EINVAL;
1076                         goto out;
1077                         break;
1078         }
1079
1080         /* find a handler for it */
1081         handler_status = 0;
1082         nmh = o2net_handler_get(be16_to_cpu(hdr->msg_type),
1083                                 be32_to_cpu(hdr->key));
1084         if (!nmh) {
1085                 mlog(ML_TCP, "couldn't find handler for type %u key %08x\n",
1086                      be16_to_cpu(hdr->msg_type), be32_to_cpu(hdr->key));
1087                 syserr = O2NET_ERR_NO_HNDLR;
1088                 goto out_respond;
1089         }
1090
1091         syserr = O2NET_ERR_NONE;
1092
1093         if (be16_to_cpu(hdr->data_len) > nmh->nh_max_len)
1094                 syserr = O2NET_ERR_OVERFLOW;
1095
1096         if (syserr != O2NET_ERR_NONE)
1097                 goto out_respond;
1098
1099         do_gettimeofday(&sc->sc_tv_func_start);
1100         sc->sc_msg_key = be32_to_cpu(hdr->key);
1101         sc->sc_msg_type = be16_to_cpu(hdr->msg_type);
1102         handler_status = (nmh->nh_func)(hdr, sizeof(struct o2net_msg) +
1103                                              be16_to_cpu(hdr->data_len),
1104                                         nmh->nh_func_data);
1105         do_gettimeofday(&sc->sc_tv_func_stop);
1106
1107 out_respond:
1108         /* this destroys the hdr, so don't use it after this */
1109         ret = o2net_send_status_magic(sc->sc_sock, hdr, syserr,
1110                                       handler_status);
1111         hdr = NULL;
1112         mlog(0, "sending handler status %d, syserr %d returned %d\n",
1113              handler_status, syserr, ret);
1114
1115 out:
1116         if (nmh)
1117                 o2net_handler_put(nmh);
1118         return ret;
1119 }
1120
1121 static int o2net_check_handshake(struct o2net_sock_container *sc)
1122 {
1123         struct o2net_handshake *hand = page_address(sc->sc_page);
1124         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1125
1126         if (hand->protocol_version != cpu_to_be64(O2NET_PROTOCOL_VERSION)) {
1127                 mlog(ML_NOTICE, SC_NODEF_FMT " advertised net protocol "
1128                      "version %llu but %llu is required, disconnecting\n",
1129                      SC_NODEF_ARGS(sc),
1130                      (unsigned long long)be64_to_cpu(hand->protocol_version),
1131                      O2NET_PROTOCOL_VERSION);
1132
1133                 /* don't bother reconnecting if its the wrong version. */
1134                 o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1135                 return -1;
1136         }
1137
1138         /*
1139          * Ensure timeouts are consistent with other nodes, otherwise
1140          * we can end up with one node thinking that the other must be down,
1141          * but isn't. This can ultimately cause corruption.
1142          */
1143         if (be32_to_cpu(hand->o2net_idle_timeout_ms) !=
1144                                 o2net_idle_timeout(sc->sc_node)) {
1145                 mlog(ML_NOTICE, SC_NODEF_FMT " uses a network idle timeout of "
1146                      "%u ms, but we use %u ms locally.  disconnecting\n",
1147                      SC_NODEF_ARGS(sc),
1148                      be32_to_cpu(hand->o2net_idle_timeout_ms),
1149                      o2net_idle_timeout(sc->sc_node));
1150                 o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1151                 return -1;
1152         }
1153
1154         if (be32_to_cpu(hand->o2net_keepalive_delay_ms) !=
1155                         o2net_keepalive_delay(sc->sc_node)) {
1156                 mlog(ML_NOTICE, SC_NODEF_FMT " uses a keepalive delay of "
1157                      "%u ms, but we use %u ms locally.  disconnecting\n",
1158                      SC_NODEF_ARGS(sc),
1159                      be32_to_cpu(hand->o2net_keepalive_delay_ms),
1160                      o2net_keepalive_delay(sc->sc_node));
1161                 o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1162                 return -1;
1163         }
1164
1165         if (be32_to_cpu(hand->o2hb_heartbeat_timeout_ms) !=
1166                         O2HB_MAX_WRITE_TIMEOUT_MS) {
1167                 mlog(ML_NOTICE, SC_NODEF_FMT " uses a heartbeat timeout of "
1168                      "%u ms, but we use %u ms locally.  disconnecting\n",
1169                      SC_NODEF_ARGS(sc),
1170                      be32_to_cpu(hand->o2hb_heartbeat_timeout_ms),
1171                      O2HB_MAX_WRITE_TIMEOUT_MS);
1172                 o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1173                 return -1;
1174         }
1175
1176         sc->sc_handshake_ok = 1;
1177
1178         spin_lock(&nn->nn_lock);
1179         /* set valid and queue the idle timers only if it hasn't been
1180          * shut down already */
1181         if (nn->nn_sc == sc) {
1182                 o2net_sc_reset_idle_timer(sc);
1183                 o2net_set_nn_state(nn, sc, 1, 0);
1184         }
1185         spin_unlock(&nn->nn_lock);
1186
1187         /* shift everything up as though it wasn't there */
1188         sc->sc_page_off -= sizeof(struct o2net_handshake);
1189         if (sc->sc_page_off)
1190                 memmove(hand, hand + 1, sc->sc_page_off);
1191
1192         return 0;
1193 }
1194
1195 /* this demuxes the queued rx bytes into header or payload bits and calls
1196  * handlers as each full message is read off the socket.  it returns -error,
1197  * == 0 eof, or > 0 for progress made.*/
1198 static int o2net_advance_rx(struct o2net_sock_container *sc)
1199 {
1200         struct o2net_msg *hdr;
1201         int ret = 0;
1202         void *data;
1203         size_t datalen;
1204
1205         sclog(sc, "receiving\n");
1206         do_gettimeofday(&sc->sc_tv_advance_start);
1207
1208         if (unlikely(sc->sc_handshake_ok == 0)) {
1209                 if(sc->sc_page_off < sizeof(struct o2net_handshake)) {
1210                         data = page_address(sc->sc_page) + sc->sc_page_off;
1211                         datalen = sizeof(struct o2net_handshake) - sc->sc_page_off;
1212                         ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1213                         if (ret > 0)
1214                                 sc->sc_page_off += ret;
1215                 }
1216
1217                 if (sc->sc_page_off == sizeof(struct o2net_handshake)) {
1218                         o2net_check_handshake(sc);
1219                         if (unlikely(sc->sc_handshake_ok == 0))
1220                                 ret = -EPROTO;
1221                 }
1222                 goto out;
1223         }
1224
1225         /* do we need more header? */
1226         if (sc->sc_page_off < sizeof(struct o2net_msg)) {
1227                 data = page_address(sc->sc_page) + sc->sc_page_off;
1228                 datalen = sizeof(struct o2net_msg) - sc->sc_page_off;
1229                 ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1230                 if (ret > 0) {
1231                         sc->sc_page_off += ret;
1232                         /* only swab incoming here.. we can
1233                          * only get here once as we cross from
1234                          * being under to over */
1235                         if (sc->sc_page_off == sizeof(struct o2net_msg)) {
1236                                 hdr = page_address(sc->sc_page);
1237                                 if (be16_to_cpu(hdr->data_len) >
1238                                     O2NET_MAX_PAYLOAD_BYTES)
1239                                         ret = -EOVERFLOW;
1240                         }
1241                 }
1242                 if (ret <= 0)
1243                         goto out;
1244         }
1245
1246         if (sc->sc_page_off < sizeof(struct o2net_msg)) {
1247                 /* oof, still don't have a header */
1248                 goto out;
1249         }
1250
1251         /* this was swabbed above when we first read it */
1252         hdr = page_address(sc->sc_page);
1253
1254         msglog(hdr, "at page_off %zu\n", sc->sc_page_off);
1255
1256         /* do we need more payload? */
1257         if (sc->sc_page_off - sizeof(struct o2net_msg) < be16_to_cpu(hdr->data_len)) {
1258                 /* need more payload */
1259                 data = page_address(sc->sc_page) + sc->sc_page_off;
1260                 datalen = (sizeof(struct o2net_msg) + be16_to_cpu(hdr->data_len)) -
1261                           sc->sc_page_off;
1262                 ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1263                 if (ret > 0)
1264                         sc->sc_page_off += ret;
1265                 if (ret <= 0)
1266                         goto out;
1267         }
1268
1269         if (sc->sc_page_off - sizeof(struct o2net_msg) == be16_to_cpu(hdr->data_len)) {
1270                 /* we can only get here once, the first time we read
1271                  * the payload.. so set ret to progress if the handler
1272                  * works out. after calling this the message is toast */
1273                 ret = o2net_process_message(sc, hdr);
1274                 if (ret == 0)
1275                         ret = 1;
1276                 sc->sc_page_off = 0;
1277         }
1278
1279 out:
1280         sclog(sc, "ret = %d\n", ret);
1281         do_gettimeofday(&sc->sc_tv_advance_stop);
1282         return ret;
1283 }
1284
1285 /* this work func is triggerd by data ready.  it reads until it can read no
1286  * more.  it interprets 0, eof, as fatal.  if data_ready hits while we're doing
1287  * our work the work struct will be marked and we'll be called again. */
1288 static void o2net_rx_until_empty(struct work_struct *work)
1289 {
1290         struct o2net_sock_container *sc =
1291                 container_of(work, struct o2net_sock_container, sc_rx_work);
1292         int ret;
1293
1294         do {
1295                 ret = o2net_advance_rx(sc);
1296         } while (ret > 0);
1297
1298         if (ret <= 0 && ret != -EAGAIN) {
1299                 struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1300                 sclog(sc, "saw error %d, closing\n", ret);
1301                 /* not permanent so read failed handshake can retry */
1302                 o2net_ensure_shutdown(nn, sc, 0);
1303         }
1304
1305         sc_put(sc);
1306 }
1307
1308 static int o2net_set_nodelay(struct socket *sock)
1309 {
1310         int ret, val = 1;
1311         mm_segment_t oldfs;
1312
1313         oldfs = get_fs();
1314         set_fs(KERNEL_DS);
1315
1316         /*
1317          * Dear unsuspecting programmer,
1318          *
1319          * Don't use sock_setsockopt() for SOL_TCP.  It doesn't check its level
1320          * argument and assumes SOL_SOCKET so, say, your TCP_NODELAY will
1321          * silently turn into SO_DEBUG.
1322          *
1323          * Yours,
1324          * Keeper of hilariously fragile interfaces.
1325          */
1326         ret = sock->ops->setsockopt(sock, SOL_TCP, TCP_NODELAY,
1327                                     (char __user *)&val, sizeof(val));
1328
1329         set_fs(oldfs);
1330         return ret;
1331 }
1332
1333 static void o2net_initialize_handshake(void)
1334 {
1335         o2net_hand->o2hb_heartbeat_timeout_ms = cpu_to_be32(
1336                 O2HB_MAX_WRITE_TIMEOUT_MS);
1337         o2net_hand->o2net_idle_timeout_ms = cpu_to_be32(
1338                 o2net_idle_timeout(NULL));
1339         o2net_hand->o2net_keepalive_delay_ms = cpu_to_be32(
1340                 o2net_keepalive_delay(NULL));
1341         o2net_hand->o2net_reconnect_delay_ms = cpu_to_be32(
1342                 o2net_reconnect_delay(NULL));
1343 }
1344
1345 /* ------------------------------------------------------------ */
1346
1347 /* called when a connect completes and after a sock is accepted.  the
1348  * rx path will see the response and mark the sc valid */
1349 static void o2net_sc_connect_completed(struct work_struct *work)
1350 {
1351         struct o2net_sock_container *sc =
1352                 container_of(work, struct o2net_sock_container,
1353                              sc_connect_work);
1354
1355         mlog(ML_MSG, "sc sending handshake with ver %llu id %llx\n",
1356               (unsigned long long)O2NET_PROTOCOL_VERSION,
1357               (unsigned long long)be64_to_cpu(o2net_hand->connector_id));
1358
1359         o2net_initialize_handshake();
1360         o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
1361         sc_put(sc);
1362 }
1363
1364 /* this is called as a work_struct func. */
1365 static void o2net_sc_send_keep_req(struct work_struct *work)
1366 {
1367         struct o2net_sock_container *sc =
1368                 container_of(work, struct o2net_sock_container,
1369                              sc_keepalive_work.work);
1370
1371         o2net_sendpage(sc, o2net_keep_req, sizeof(*o2net_keep_req));
1372         sc_put(sc);
1373 }
1374
1375 /* socket shutdown does a del_timer_sync against this as it tears down.
1376  * we can't start this timer until we've got to the point in sc buildup
1377  * where shutdown is going to be involved */
1378 static void o2net_idle_timer(unsigned long data)
1379 {
1380         struct o2net_sock_container *sc = (struct o2net_sock_container *)data;
1381         struct timeval now;
1382
1383         do_gettimeofday(&now);
1384
1385         printk(KERN_INFO "o2net: connection to " SC_NODEF_FMT " has been idle for %u.%u "
1386              "seconds, shutting it down.\n", SC_NODEF_ARGS(sc),
1387                      o2net_idle_timeout(sc->sc_node) / 1000,
1388                      o2net_idle_timeout(sc->sc_node) % 1000);
1389         mlog(ML_NOTICE, "here are some times that might help debug the "
1390              "situation: (tmr %ld.%ld now %ld.%ld dr %ld.%ld adv "
1391              "%ld.%ld:%ld.%ld func (%08x:%u) %ld.%ld:%ld.%ld)\n",
1392              sc->sc_tv_timer.tv_sec, (long) sc->sc_tv_timer.tv_usec, 
1393              now.tv_sec, (long) now.tv_usec,
1394              sc->sc_tv_data_ready.tv_sec, (long) sc->sc_tv_data_ready.tv_usec,
1395              sc->sc_tv_advance_start.tv_sec,
1396              (long) sc->sc_tv_advance_start.tv_usec,
1397              sc->sc_tv_advance_stop.tv_sec,
1398              (long) sc->sc_tv_advance_stop.tv_usec,
1399              sc->sc_msg_key, sc->sc_msg_type,
1400              sc->sc_tv_func_start.tv_sec, (long) sc->sc_tv_func_start.tv_usec,
1401              sc->sc_tv_func_stop.tv_sec, (long) sc->sc_tv_func_stop.tv_usec);
1402
1403         o2net_sc_queue_work(sc, &sc->sc_shutdown_work);
1404 }
1405
1406 static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc)
1407 {
1408         o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
1409         o2net_sc_queue_delayed_work(sc, &sc->sc_keepalive_work,
1410                       msecs_to_jiffies(o2net_keepalive_delay(sc->sc_node)));
1411         do_gettimeofday(&sc->sc_tv_timer);
1412         mod_timer(&sc->sc_idle_timeout,
1413                jiffies + msecs_to_jiffies(o2net_idle_timeout(sc->sc_node)));
1414 }
1415
1416 static void o2net_sc_postpone_idle(struct o2net_sock_container *sc)
1417 {
1418         /* Only push out an existing timer */
1419         if (timer_pending(&sc->sc_idle_timeout))
1420                 o2net_sc_reset_idle_timer(sc);
1421 }
1422
1423 /* this work func is kicked whenever a path sets the nn state which doesn't
1424  * have valid set.  This includes seeing hb come up, losing a connection,
1425  * having a connect attempt fail, etc. This centralizes the logic which decides
1426  * if a connect attempt should be made or if we should give up and all future
1427  * transmit attempts should fail */
1428 static void o2net_start_connect(struct work_struct *work)
1429 {
1430         struct o2net_node *nn =
1431                 container_of(work, struct o2net_node, nn_connect_work.work);
1432         struct o2net_sock_container *sc = NULL;
1433         struct o2nm_node *node = NULL, *mynode = NULL;
1434         struct socket *sock = NULL;
1435         struct sockaddr_in myaddr = {0, }, remoteaddr = {0, };
1436         int ret = 0, stop;
1437
1438         /* if we're greater we initiate tx, otherwise we accept */
1439         if (o2nm_this_node() <= o2net_num_from_nn(nn))
1440                 goto out;
1441
1442         /* watch for racing with tearing a node down */
1443         node = o2nm_get_node_by_num(o2net_num_from_nn(nn));
1444         if (node == NULL) {
1445                 ret = 0;
1446                 goto out;
1447         }
1448
1449         mynode = o2nm_get_node_by_num(o2nm_this_node());
1450         if (mynode == NULL) {
1451                 ret = 0;
1452                 goto out;
1453         }
1454
1455         spin_lock(&nn->nn_lock);
1456         /* see if we already have one pending or have given up */
1457         stop = (nn->nn_sc || nn->nn_persistent_error);
1458         spin_unlock(&nn->nn_lock);
1459         if (stop)
1460                 goto out;
1461
1462         nn->nn_last_connect_attempt = jiffies;
1463
1464         sc = sc_alloc(node);
1465         if (sc == NULL) {
1466                 mlog(0, "couldn't allocate sc\n");
1467                 ret = -ENOMEM;
1468                 goto out;
1469         }
1470
1471         ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
1472         if (ret < 0) {
1473                 mlog(0, "can't create socket: %d\n", ret);
1474                 goto out;
1475         }
1476         sc->sc_sock = sock; /* freed by sc_kref_release */
1477
1478         sock->sk->sk_allocation = GFP_ATOMIC;
1479
1480         myaddr.sin_family = AF_INET;
1481         myaddr.sin_addr.s_addr = (__force u32)mynode->nd_ipv4_address;
1482         myaddr.sin_port = (__force u16)htons(0); /* any port */
1483
1484         ret = sock->ops->bind(sock, (struct sockaddr *)&myaddr,
1485                               sizeof(myaddr));
1486         if (ret) {
1487                 mlog(ML_ERROR, "bind failed with %d at address %u.%u.%u.%u\n",
1488                      ret, NIPQUAD(mynode->nd_ipv4_address));
1489                 goto out;
1490         }
1491
1492         ret = o2net_set_nodelay(sc->sc_sock);
1493         if (ret) {
1494                 mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret);
1495                 goto out;
1496         }
1497
1498         o2net_register_callbacks(sc->sc_sock->sk, sc);
1499
1500         spin_lock(&nn->nn_lock);
1501         /* handshake completion will set nn->nn_sc_valid */
1502         o2net_set_nn_state(nn, sc, 0, 0);
1503         spin_unlock(&nn->nn_lock);
1504
1505         remoteaddr.sin_family = AF_INET;
1506         remoteaddr.sin_addr.s_addr = (__force u32)node->nd_ipv4_address;
1507         remoteaddr.sin_port = (__force u16)node->nd_ipv4_port;
1508
1509         ret = sc->sc_sock->ops->connect(sc->sc_sock,
1510                                         (struct sockaddr *)&remoteaddr,
1511                                         sizeof(remoteaddr),
1512                                         O_NONBLOCK);
1513         if (ret == -EINPROGRESS)
1514                 ret = 0;
1515
1516 out:
1517         if (ret) {
1518                 mlog(ML_NOTICE, "connect attempt to " SC_NODEF_FMT " failed "
1519                      "with errno %d\n", SC_NODEF_ARGS(sc), ret);
1520                 /* 0 err so that another will be queued and attempted
1521                  * from set_nn_state */
1522                 if (sc)
1523                         o2net_ensure_shutdown(nn, sc, 0);
1524         }
1525         if (sc)
1526                 sc_put(sc);
1527         if (node)
1528                 o2nm_node_put(node);
1529         if (mynode)
1530                 o2nm_node_put(mynode);
1531
1532         return;
1533 }
1534
1535 static void o2net_connect_expired(struct work_struct *work)
1536 {
1537         struct o2net_node *nn =
1538                 container_of(work, struct o2net_node, nn_connect_expired.work);
1539
1540         spin_lock(&nn->nn_lock);
1541         if (!nn->nn_sc_valid) {
1542                 struct o2nm_node *node = nn->nn_sc->sc_node;
1543                 mlog(ML_ERROR, "no connection established with node %u after "
1544                      "%u.%u seconds, giving up and returning errors.\n",
1545                      o2net_num_from_nn(nn),
1546                      o2net_idle_timeout(node) / 1000,
1547                      o2net_idle_timeout(node) % 1000);
1548
1549                 o2net_set_nn_state(nn, NULL, 0, -ENOTCONN);
1550         }
1551         spin_unlock(&nn->nn_lock);
1552 }
1553
1554 static void o2net_still_up(struct work_struct *work)
1555 {
1556         struct o2net_node *nn =
1557                 container_of(work, struct o2net_node, nn_still_up.work);
1558
1559         o2quo_hb_still_up(o2net_num_from_nn(nn));
1560 }
1561
1562 /* ------------------------------------------------------------ */
1563
1564 void o2net_disconnect_node(struct o2nm_node *node)
1565 {
1566         struct o2net_node *nn = o2net_nn_from_num(node->nd_num);
1567
1568         /* don't reconnect until it's heartbeating again */
1569         spin_lock(&nn->nn_lock);
1570         o2net_set_nn_state(nn, NULL, 0, -ENOTCONN);
1571         spin_unlock(&nn->nn_lock);
1572
1573         if (o2net_wq) {
1574                 cancel_delayed_work(&nn->nn_connect_expired);
1575                 cancel_delayed_work(&nn->nn_connect_work);
1576                 cancel_delayed_work(&nn->nn_still_up);
1577                 flush_workqueue(o2net_wq);
1578         }
1579 }
1580
1581 static void o2net_hb_node_down_cb(struct o2nm_node *node, int node_num,
1582                                   void *data)
1583 {
1584         o2quo_hb_down(node_num);
1585
1586         if (node_num != o2nm_this_node())
1587                 o2net_disconnect_node(node);
1588
1589         BUG_ON(atomic_read(&o2net_connected_peers) < 0);
1590 }
1591
1592 static void o2net_hb_node_up_cb(struct o2nm_node *node, int node_num,
1593                                 void *data)
1594 {
1595         struct o2net_node *nn = o2net_nn_from_num(node_num);
1596
1597         o2quo_hb_up(node_num);
1598
1599         /* ensure an immediate connect attempt */
1600         nn->nn_last_connect_attempt = jiffies -
1601                 (msecs_to_jiffies(o2net_reconnect_delay(node)) + 1);
1602
1603         if (node_num != o2nm_this_node()) {
1604                 /* heartbeat doesn't work unless a local node number is
1605                  * configured and doing so brings up the o2net_wq, so we can
1606                  * use it.. */
1607                 queue_delayed_work(o2net_wq, &nn->nn_connect_expired,
1608                                    msecs_to_jiffies(o2net_idle_timeout(node)));
1609
1610                 /* believe it or not, accept and node hearbeating testing
1611                  * can succeed for this node before we got here.. so
1612                  * only use set_nn_state to clear the persistent error
1613                  * if that hasn't already happened */
1614                 spin_lock(&nn->nn_lock);
1615                 if (nn->nn_persistent_error)
1616                         o2net_set_nn_state(nn, NULL, 0, 0);
1617                 spin_unlock(&nn->nn_lock);
1618         }
1619 }
1620
1621 void o2net_unregister_hb_callbacks(void)
1622 {
1623         int ret;
1624
1625         ret = o2hb_unregister_callback(&o2net_hb_up);
1626         if (ret < 0)
1627                 mlog(ML_ERROR, "Status return %d unregistering heartbeat up "
1628                      "callback!\n", ret);
1629
1630         ret = o2hb_unregister_callback(&o2net_hb_down);
1631         if (ret < 0)
1632                 mlog(ML_ERROR, "Status return %d unregistering heartbeat down "
1633                      "callback!\n", ret);
1634 }
1635
1636 int o2net_register_hb_callbacks(void)
1637 {
1638         int ret;
1639
1640         o2hb_setup_callback(&o2net_hb_down, O2HB_NODE_DOWN_CB,
1641                             o2net_hb_node_down_cb, NULL, O2NET_HB_PRI);
1642         o2hb_setup_callback(&o2net_hb_up, O2HB_NODE_UP_CB,
1643                             o2net_hb_node_up_cb, NULL, O2NET_HB_PRI);
1644
1645         ret = o2hb_register_callback(&o2net_hb_up);
1646         if (ret == 0)
1647                 ret = o2hb_register_callback(&o2net_hb_down);
1648
1649         if (ret)
1650                 o2net_unregister_hb_callbacks();
1651
1652         return ret;
1653 }
1654
1655 /* ------------------------------------------------------------ */
1656
1657 static int o2net_accept_one(struct socket *sock)
1658 {
1659         int ret, slen;
1660         struct sockaddr_in sin;
1661         struct socket *new_sock = NULL;
1662         struct o2nm_node *node = NULL;
1663         struct o2net_sock_container *sc = NULL;
1664         struct o2net_node *nn;
1665
1666         BUG_ON(sock == NULL);
1667         ret = sock_create_lite(sock->sk->sk_family, sock->sk->sk_type,
1668                                sock->sk->sk_protocol, &new_sock);
1669         if (ret)
1670                 goto out;
1671
1672         new_sock->type = sock->type;
1673         new_sock->ops = sock->ops;
1674         ret = sock->ops->accept(sock, new_sock, O_NONBLOCK);
1675         if (ret < 0)
1676                 goto out;
1677
1678         new_sock->sk->sk_allocation = GFP_ATOMIC;
1679
1680         ret = o2net_set_nodelay(new_sock);
1681         if (ret) {
1682                 mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret);
1683                 goto out;
1684         }
1685
1686         slen = sizeof(sin);
1687         ret = new_sock->ops->getname(new_sock, (struct sockaddr *) &sin,
1688                                        &slen, 1);
1689         if (ret < 0)
1690                 goto out;
1691
1692         node = o2nm_get_node_by_ip((__force __be32)sin.sin_addr.s_addr);
1693         if (node == NULL) {
1694                 mlog(ML_NOTICE, "attempt to connect from unknown node at "
1695                      "%u.%u.%u.%u:%d\n", NIPQUAD(sin.sin_addr.s_addr),
1696                      ntohs((__force __be16)sin.sin_port));
1697                 ret = -EINVAL;
1698                 goto out;
1699         }
1700
1701         if (o2nm_this_node() > node->nd_num) {
1702                 mlog(ML_NOTICE, "unexpected connect attempted from a lower "
1703                      "numbered node '%s' at " "%u.%u.%u.%u:%d with num %u\n",
1704                      node->nd_name, NIPQUAD(sin.sin_addr.s_addr),
1705                      ntohs((__force __be16)sin.sin_port), node->nd_num);
1706                 ret = -EINVAL;
1707                 goto out;
1708         }
1709
1710         /* this happens all the time when the other node sees our heartbeat
1711          * and tries to connect before we see their heartbeat */
1712         if (!o2hb_check_node_heartbeating_from_callback(node->nd_num)) {
1713                 mlog(ML_CONN, "attempt to connect from node '%s' at "
1714                      "%u.%u.%u.%u:%d but it isn't heartbeating\n",
1715                      node->nd_name, NIPQUAD(sin.sin_addr.s_addr),
1716                      ntohs((__force __be16)sin.sin_port));
1717                 ret = -EINVAL;
1718                 goto out;
1719         }
1720
1721         nn = o2net_nn_from_num(node->nd_num);
1722
1723         spin_lock(&nn->nn_lock);
1724         if (nn->nn_sc)
1725                 ret = -EBUSY;
1726         else
1727                 ret = 0;
1728         spin_unlock(&nn->nn_lock);
1729         if (ret) {
1730                 mlog(ML_NOTICE, "attempt to connect from node '%s' at "
1731                      "%u.%u.%u.%u:%d but it already has an open connection\n",
1732                      node->nd_name, NIPQUAD(sin.sin_addr.s_addr),
1733                      ntohs((__force __be16)sin.sin_port));
1734                 goto out;
1735         }
1736
1737         sc = sc_alloc(node);
1738         if (sc == NULL) {
1739                 ret = -ENOMEM;
1740                 goto out;
1741         }
1742
1743         sc->sc_sock = new_sock;
1744         new_sock = NULL;
1745
1746         spin_lock(&nn->nn_lock);
1747         o2net_set_nn_state(nn, sc, 0, 0);
1748         spin_unlock(&nn->nn_lock);
1749
1750         o2net_register_callbacks(sc->sc_sock->sk, sc);
1751         o2net_sc_queue_work(sc, &sc->sc_rx_work);
1752
1753         o2net_initialize_handshake();
1754         o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
1755
1756 out:
1757         if (new_sock)
1758                 sock_release(new_sock);
1759         if (node)
1760                 o2nm_node_put(node);
1761         if (sc)
1762                 sc_put(sc);
1763         return ret;
1764 }
1765
1766 static void o2net_accept_many(struct work_struct *work)
1767 {
1768         struct socket *sock = o2net_listen_sock;
1769         while (o2net_accept_one(sock) == 0)
1770                 cond_resched();
1771 }
1772
1773 static void o2net_listen_data_ready(struct sock *sk, int bytes)
1774 {
1775         void (*ready)(struct sock *sk, int bytes);
1776
1777         read_lock(&sk->sk_callback_lock);
1778         ready = sk->sk_user_data;
1779         if (ready == NULL) { /* check for teardown race */
1780                 ready = sk->sk_data_ready;
1781                 goto out;
1782         }
1783
1784         /* ->sk_data_ready is also called for a newly established child socket
1785          * before it has been accepted and the acceptor has set up their
1786          * data_ready.. we only want to queue listen work for our listening
1787          * socket */
1788         if (sk->sk_state == TCP_LISTEN) {
1789                 mlog(ML_TCP, "bytes: %d\n", bytes);
1790                 queue_work(o2net_wq, &o2net_listen_work);
1791         }
1792
1793 out:
1794         read_unlock(&sk->sk_callback_lock);
1795         ready(sk, bytes);
1796 }
1797
1798 static int o2net_open_listening_sock(__be16 port)
1799 {
1800         struct socket *sock = NULL;
1801         int ret;
1802         struct sockaddr_in sin = {
1803                 .sin_family = PF_INET,
1804                 .sin_addr = { .s_addr = (__force u32)htonl(INADDR_ANY) },
1805                 .sin_port = (__force u16)port,
1806         };
1807
1808         ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
1809         if (ret < 0) {
1810                 mlog(ML_ERROR, "unable to create socket, ret=%d\n", ret);
1811                 goto out;
1812         }
1813
1814         sock->sk->sk_allocation = GFP_ATOMIC;
1815
1816         write_lock_bh(&sock->sk->sk_callback_lock);
1817         sock->sk->sk_user_data = sock->sk->sk_data_ready;
1818         sock->sk->sk_data_ready = o2net_listen_data_ready;
1819         write_unlock_bh(&sock->sk->sk_callback_lock);
1820
1821         o2net_listen_sock = sock;
1822         INIT_WORK(&o2net_listen_work, o2net_accept_many);
1823
1824         sock->sk->sk_reuse = 1;
1825         ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
1826         if (ret < 0) {
1827                 mlog(ML_ERROR, "unable to bind socket to port %d, ret=%d\n",
1828                      ntohs(port), ret);
1829                 goto out;
1830         }
1831
1832         ret = sock->ops->listen(sock, 64);
1833         if (ret < 0) {
1834                 mlog(ML_ERROR, "unable to listen on port %d, ret=%d\n",
1835                      ntohs(port), ret);
1836         }
1837
1838 out:
1839         if (ret) {
1840                 o2net_listen_sock = NULL;
1841                 if (sock)
1842                         sock_release(sock);
1843         }
1844         return ret;
1845 }
1846
1847 /*
1848  * called from node manager when we should bring up our network listening
1849  * socket.  node manager handles all the serialization to only call this
1850  * once and to match it with o2net_stop_listening().  note,
1851  * o2nm_this_node() doesn't work yet as we're being called while it
1852  * is being set up.
1853  */
1854 int o2net_start_listening(struct o2nm_node *node)
1855 {
1856         int ret = 0;
1857
1858         BUG_ON(o2net_wq != NULL);
1859         BUG_ON(o2net_listen_sock != NULL);
1860
1861         mlog(ML_KTHREAD, "starting o2net thread...\n");
1862         o2net_wq = create_singlethread_workqueue("o2net");
1863         if (o2net_wq == NULL) {
1864                 mlog(ML_ERROR, "unable to launch o2net thread\n");
1865                 return -ENOMEM; /* ? */
1866         }
1867
1868         ret = o2net_open_listening_sock(node->nd_ipv4_port);
1869         if (ret) {
1870                 destroy_workqueue(o2net_wq);
1871                 o2net_wq = NULL;
1872         } else
1873                 o2quo_conn_up(node->nd_num);
1874
1875         return ret;
1876 }
1877
1878 /* again, o2nm_this_node() doesn't work here as we're involved in
1879  * tearing it down */
1880 void o2net_stop_listening(struct o2nm_node *node)
1881 {
1882         struct socket *sock = o2net_listen_sock;
1883         size_t i;
1884
1885         BUG_ON(o2net_wq == NULL);
1886         BUG_ON(o2net_listen_sock == NULL);
1887
1888         /* stop the listening socket from generating work */
1889         write_lock_bh(&sock->sk->sk_callback_lock);
1890         sock->sk->sk_data_ready = sock->sk->sk_user_data;
1891         sock->sk->sk_user_data = NULL;
1892         write_unlock_bh(&sock->sk->sk_callback_lock);
1893
1894         for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
1895                 struct o2nm_node *node = o2nm_get_node_by_num(i);
1896                 if (node) {
1897                         o2net_disconnect_node(node);
1898                         o2nm_node_put(node);
1899                 }
1900         }
1901
1902         /* finish all work and tear down the work queue */
1903         mlog(ML_KTHREAD, "waiting for o2net thread to exit....\n");
1904         destroy_workqueue(o2net_wq);
1905         o2net_wq = NULL;
1906
1907         sock_release(o2net_listen_sock);
1908         o2net_listen_sock = NULL;
1909
1910         o2quo_conn_err(node->nd_num);
1911 }
1912
1913 /* ------------------------------------------------------------ */
1914
1915 int o2net_init(void)
1916 {
1917         unsigned long i;
1918
1919         o2quo_init();
1920
1921         o2net_hand = kcalloc(1, sizeof(struct o2net_handshake), GFP_KERNEL);
1922         o2net_keep_req = kcalloc(1, sizeof(struct o2net_msg), GFP_KERNEL);
1923         o2net_keep_resp = kcalloc(1, sizeof(struct o2net_msg), GFP_KERNEL);
1924         if (!o2net_hand || !o2net_keep_req || !o2net_keep_resp) {
1925                 kfree(o2net_hand);
1926                 kfree(o2net_keep_req);
1927                 kfree(o2net_keep_resp);
1928                 return -ENOMEM;
1929         }
1930
1931         o2net_hand->protocol_version = cpu_to_be64(O2NET_PROTOCOL_VERSION);
1932         o2net_hand->connector_id = cpu_to_be64(1);
1933
1934         o2net_keep_req->magic = cpu_to_be16(O2NET_MSG_KEEP_REQ_MAGIC);
1935         o2net_keep_resp->magic = cpu_to_be16(O2NET_MSG_KEEP_RESP_MAGIC);
1936
1937         for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
1938                 struct o2net_node *nn = o2net_nn_from_num(i);
1939
1940                 spin_lock_init(&nn->nn_lock);
1941                 INIT_DELAYED_WORK(&nn->nn_connect_work, o2net_start_connect);
1942                 INIT_DELAYED_WORK(&nn->nn_connect_expired,
1943                                   o2net_connect_expired);
1944                 INIT_DELAYED_WORK(&nn->nn_still_up, o2net_still_up);
1945                 /* until we see hb from a node we'll return einval */
1946                 nn->nn_persistent_error = -ENOTCONN;
1947                 init_waitqueue_head(&nn->nn_sc_wq);
1948                 idr_init(&nn->nn_status_idr);
1949                 INIT_LIST_HEAD(&nn->nn_status_list);
1950         }
1951
1952         return 0;
1953 }
1954
1955 void o2net_exit(void)
1956 {
1957         o2quo_exit();
1958         kfree(o2net_hand);
1959         kfree(o2net_keep_req);
1960         kfree(o2net_keep_resp);
1961 }