ocfs2: Fix NULL pointer dereferences in o2net
[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 <linux/net.h>
62 #include <net/tcp.h>
63
64 #include <asm/uaccess.h>
65
66 #include "heartbeat.h"
67 #include "tcp.h"
68 #include "nodemanager.h"
69 #define MLOG_MASK_PREFIX ML_TCP
70 #include "masklog.h"
71 #include "quorum.h"
72
73 #include "tcp_internal.h"
74
75 #define SC_NODEF_FMT "node %s (num %u) at %u.%u.%u.%u:%u"
76 #define SC_NODEF_ARGS(sc) sc->sc_node->nd_name, sc->sc_node->nd_num,    \
77                           NIPQUAD(sc->sc_node->nd_ipv4_address),        \
78                           ntohs(sc->sc_node->nd_ipv4_port)
79
80 /*
81  * In the following two log macros, the whitespace after the ',' just
82  * before ##args is intentional. Otherwise, gcc 2.95 will eat the
83  * previous token if args expands to nothing.
84  */
85 #define msglog(hdr, fmt, args...) do {                                  \
86         typeof(hdr) __hdr = (hdr);                                      \
87         mlog(ML_MSG, "[mag %u len %u typ %u stat %d sys_stat %d "       \
88              "key %08x num %u] " fmt,                                   \
89              be16_to_cpu(__hdr->magic), be16_to_cpu(__hdr->data_len),   \
90              be16_to_cpu(__hdr->msg_type), be32_to_cpu(__hdr->status),  \
91              be32_to_cpu(__hdr->sys_status), be32_to_cpu(__hdr->key),   \
92              be32_to_cpu(__hdr->msg_num) ,  ##args);                    \
93 } while (0)
94
95 #define sclog(sc, fmt, args...) do {                                    \
96         typeof(sc) __sc = (sc);                                         \
97         mlog(ML_SOCKET, "[sc %p refs %d sock %p node %u page %p "       \
98              "pg_off %zu] " fmt, __sc,                                  \
99              atomic_read(&__sc->sc_kref.refcount), __sc->sc_sock,       \
100             __sc->sc_node->nd_num, __sc->sc_page, __sc->sc_page_off ,   \
101             ##args);                                                    \
102 } while (0)
103
104 static DEFINE_RWLOCK(o2net_handler_lock);
105 static struct rb_root o2net_handler_tree = RB_ROOT;
106
107 static struct o2net_node o2net_nodes[O2NM_MAX_NODES];
108
109 /* XXX someday we'll need better accounting */
110 static struct socket *o2net_listen_sock = NULL;
111
112 /*
113  * listen work is only queued by the listening socket callbacks on the
114  * o2net_wq.  teardown detaches the callbacks before destroying the workqueue.
115  * quorum work is queued as sock containers are shutdown.. stop_listening
116  * tears down all the node's sock containers, preventing future shutdowns
117  * and queued quroum work, before canceling delayed quorum work and
118  * destroying the work queue.
119  */
120 static struct workqueue_struct *o2net_wq;
121 static struct work_struct o2net_listen_work;
122
123 static struct o2hb_callback_func o2net_hb_up, o2net_hb_down;
124 #define O2NET_HB_PRI 0x1
125
126 static struct o2net_handshake *o2net_hand;
127 static struct o2net_msg *o2net_keep_req, *o2net_keep_resp;
128
129 static int o2net_sys_err_translations[O2NET_ERR_MAX] =
130                 {[O2NET_ERR_NONE]       = 0,
131                  [O2NET_ERR_NO_HNDLR]   = -ENOPROTOOPT,
132                  [O2NET_ERR_OVERFLOW]   = -EOVERFLOW,
133                  [O2NET_ERR_DIED]       = -EHOSTDOWN,};
134
135 /* can't quite avoid *all* internal declarations :/ */
136 static void o2net_sc_connect_completed(struct work_struct *work);
137 static void o2net_rx_until_empty(struct work_struct *work);
138 static void o2net_shutdown_sc(struct work_struct *work);
139 static void o2net_listen_data_ready(struct sock *sk, int bytes);
140 static void o2net_sc_send_keep_req(struct work_struct *work);
141 static void o2net_idle_timer(unsigned long data);
142 static void o2net_sc_postpone_idle(struct o2net_sock_container *sc);
143 static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc);
144
145 /*
146  * FIXME: These should use to_o2nm_cluster_from_node(), but we end up
147  * losing our parent link to the cluster during shutdown. This can be
148  * solved by adding a pre-removal callback to configfs, or passing
149  * around the cluster with the node. -jeffm
150  */
151 static inline int o2net_reconnect_delay(struct o2nm_node *node)
152 {
153         return o2nm_single_cluster->cl_reconnect_delay_ms;
154 }
155
156 static inline int o2net_keepalive_delay(struct o2nm_node *node)
157 {
158         return o2nm_single_cluster->cl_keepalive_delay_ms;
159 }
160
161 static inline int o2net_idle_timeout(struct o2nm_node *node)
162 {
163         return o2nm_single_cluster->cl_idle_timeout_ms;
164 }
165
166 static inline int o2net_sys_err_to_errno(enum o2net_system_error err)
167 {
168         int trans;
169         BUG_ON(err >= O2NET_ERR_MAX);
170         trans = o2net_sys_err_translations[err];
171
172         /* Just in case we mess up the translation table above */
173         BUG_ON(err != O2NET_ERR_NONE && trans == 0);
174         return trans;
175 }
176
177 static struct o2net_node * o2net_nn_from_num(u8 node_num)
178 {
179         BUG_ON(node_num >= ARRAY_SIZE(o2net_nodes));
180         return &o2net_nodes[node_num];
181 }
182
183 static u8 o2net_num_from_nn(struct o2net_node *nn)
184 {
185         BUG_ON(nn == NULL);
186         return nn - o2net_nodes;
187 }
188
189 /* ------------------------------------------------------------ */
190
191 static int o2net_prep_nsw(struct o2net_node *nn, struct o2net_status_wait *nsw)
192 {
193         int ret = 0;
194
195         do {
196                 if (!idr_pre_get(&nn->nn_status_idr, GFP_ATOMIC)) {
197                         ret = -EAGAIN;
198                         break;
199                 }
200                 spin_lock(&nn->nn_lock);
201                 ret = idr_get_new(&nn->nn_status_idr, nsw, &nsw->ns_id);
202                 if (ret == 0)
203                         list_add_tail(&nsw->ns_node_item,
204                                       &nn->nn_status_list);
205                 spin_unlock(&nn->nn_lock);
206         } while (ret == -EAGAIN);
207
208         if (ret == 0)  {
209                 init_waitqueue_head(&nsw->ns_wq);
210                 nsw->ns_sys_status = O2NET_ERR_NONE;
211                 nsw->ns_status = 0;
212         }
213
214         return ret;
215 }
216
217 static void o2net_complete_nsw_locked(struct o2net_node *nn,
218                                       struct o2net_status_wait *nsw,
219                                       enum o2net_system_error sys_status,
220                                       s32 status)
221 {
222         assert_spin_locked(&nn->nn_lock);
223
224         if (!list_empty(&nsw->ns_node_item)) {
225                 list_del_init(&nsw->ns_node_item);
226                 nsw->ns_sys_status = sys_status;
227                 nsw->ns_status = status;
228                 idr_remove(&nn->nn_status_idr, nsw->ns_id);
229                 wake_up(&nsw->ns_wq);
230         }
231 }
232
233 static void o2net_complete_nsw(struct o2net_node *nn,
234                                struct o2net_status_wait *nsw,
235                                u64 id, enum o2net_system_error sys_status,
236                                s32 status)
237 {
238         spin_lock(&nn->nn_lock);
239         if (nsw == NULL) {
240                 if (id > INT_MAX)
241                         goto out;
242
243                 nsw = idr_find(&nn->nn_status_idr, id);
244                 if (nsw == NULL)
245                         goto out;
246         }
247
248         o2net_complete_nsw_locked(nn, nsw, sys_status, status);
249
250 out:
251         spin_unlock(&nn->nn_lock);
252         return;
253 }
254
255 static void o2net_complete_nodes_nsw(struct o2net_node *nn)
256 {
257         struct o2net_status_wait *nsw, *tmp;
258         unsigned int num_kills = 0;
259
260         assert_spin_locked(&nn->nn_lock);
261
262         list_for_each_entry_safe(nsw, tmp, &nn->nn_status_list, ns_node_item) {
263                 o2net_complete_nsw_locked(nn, nsw, O2NET_ERR_DIED, 0);
264                 num_kills++;
265         }
266
267         mlog(0, "completed %d messages for node %u\n", num_kills,
268              o2net_num_from_nn(nn));
269 }
270
271 static int o2net_nsw_completed(struct o2net_node *nn,
272                                struct o2net_status_wait *nsw)
273 {
274         int completed;
275         spin_lock(&nn->nn_lock);
276         completed = list_empty(&nsw->ns_node_item);
277         spin_unlock(&nn->nn_lock);
278         return completed;
279 }
280
281 /* ------------------------------------------------------------ */
282
283 static void sc_kref_release(struct kref *kref)
284 {
285         struct o2net_sock_container *sc = container_of(kref,
286                                         struct o2net_sock_container, sc_kref);
287         BUG_ON(timer_pending(&sc->sc_idle_timeout));
288
289         sclog(sc, "releasing\n");
290
291         if (sc->sc_sock) {
292                 sock_release(sc->sc_sock);
293                 sc->sc_sock = NULL;
294         }
295
296         o2nm_node_put(sc->sc_node);
297         sc->sc_node = NULL;
298
299         kfree(sc);
300 }
301
302 static void sc_put(struct o2net_sock_container *sc)
303 {
304         sclog(sc, "put\n");
305         kref_put(&sc->sc_kref, sc_kref_release);
306 }
307 static void sc_get(struct o2net_sock_container *sc)
308 {
309         sclog(sc, "get\n");
310         kref_get(&sc->sc_kref);
311 }
312 static struct o2net_sock_container *sc_alloc(struct o2nm_node *node)
313 {
314         struct o2net_sock_container *sc, *ret = NULL;
315         struct page *page = NULL;
316
317         page = alloc_page(GFP_NOFS);
318         sc = kzalloc(sizeof(*sc), GFP_NOFS);
319         if (sc == NULL || page == NULL)
320                 goto out;
321
322         kref_init(&sc->sc_kref);
323         o2nm_node_get(node);
324         sc->sc_node = node;
325
326         INIT_WORK(&sc->sc_connect_work, o2net_sc_connect_completed);
327         INIT_WORK(&sc->sc_rx_work, o2net_rx_until_empty);
328         INIT_WORK(&sc->sc_shutdown_work, o2net_shutdown_sc);
329         INIT_DELAYED_WORK(&sc->sc_keepalive_work, o2net_sc_send_keep_req);
330
331         init_timer(&sc->sc_idle_timeout);
332         sc->sc_idle_timeout.function = o2net_idle_timer;
333         sc->sc_idle_timeout.data = (unsigned long)sc;
334
335         sclog(sc, "alloced\n");
336
337         ret = sc;
338         sc->sc_page = page;
339         sc = NULL;
340         page = NULL;
341
342 out:
343         if (page)
344                 __free_page(page);
345         kfree(sc);
346
347         return ret;
348 }
349
350 /* ------------------------------------------------------------ */
351
352 static void o2net_sc_queue_work(struct o2net_sock_container *sc,
353                                 struct work_struct *work)
354 {
355         sc_get(sc);
356         if (!queue_work(o2net_wq, work))
357                 sc_put(sc);
358 }
359 static void o2net_sc_queue_delayed_work(struct o2net_sock_container *sc,
360                                         struct delayed_work *work,
361                                         int delay)
362 {
363         sc_get(sc);
364         if (!queue_delayed_work(o2net_wq, work, delay))
365                 sc_put(sc);
366 }
367 static void o2net_sc_cancel_delayed_work(struct o2net_sock_container *sc,
368                                          struct delayed_work *work)
369 {
370         if (cancel_delayed_work(work))
371                 sc_put(sc);
372 }
373
374 static atomic_t o2net_connected_peers = ATOMIC_INIT(0);
375
376 int o2net_num_connected_peers(void)
377 {
378         return atomic_read(&o2net_connected_peers);
379 }
380
381 static void o2net_set_nn_state(struct o2net_node *nn,
382                                struct o2net_sock_container *sc,
383                                unsigned valid, int err)
384 {
385         int was_valid = nn->nn_sc_valid;
386         int was_err = nn->nn_persistent_error;
387         struct o2net_sock_container *old_sc = nn->nn_sc;
388
389         assert_spin_locked(&nn->nn_lock);
390
391         if (old_sc && !sc)
392                 atomic_dec(&o2net_connected_peers);
393         else if (!old_sc && sc)
394                 atomic_inc(&o2net_connected_peers);
395
396         /* the node num comparison and single connect/accept path should stop
397          * an non-null sc from being overwritten with another */
398         BUG_ON(sc && nn->nn_sc && nn->nn_sc != sc);
399         mlog_bug_on_msg(err && valid, "err %d valid %u\n", err, valid);
400         mlog_bug_on_msg(valid && !sc, "valid %u sc %p\n", valid, sc);
401
402         /* we won't reconnect after our valid conn goes away for
403          * this hb iteration.. here so it shows up in the logs */
404         if (was_valid && !valid && err == 0)
405                 err = -ENOTCONN;
406
407         mlog(ML_CONN, "node %u sc: %p -> %p, valid %u -> %u, err %d -> %d\n",
408              o2net_num_from_nn(nn), nn->nn_sc, sc, nn->nn_sc_valid, valid,
409              nn->nn_persistent_error, err);
410
411         nn->nn_sc = sc;
412         nn->nn_sc_valid = valid ? 1 : 0;
413         nn->nn_persistent_error = err;
414
415         /* mirrors o2net_tx_can_proceed() */
416         if (nn->nn_persistent_error || nn->nn_sc_valid)
417                 wake_up(&nn->nn_sc_wq);
418
419         if (!was_err && nn->nn_persistent_error) {
420                 o2quo_conn_err(o2net_num_from_nn(nn));
421                 queue_delayed_work(o2net_wq, &nn->nn_still_up,
422                                    msecs_to_jiffies(O2NET_QUORUM_DELAY_MS));
423         }
424
425         if (was_valid && !valid) {
426                 printk(KERN_INFO "o2net: no longer connected to "
427                        SC_NODEF_FMT "\n", SC_NODEF_ARGS(old_sc));
428                 o2net_complete_nodes_nsw(nn);
429         }
430
431         if (!was_valid && valid) {
432                 o2quo_conn_up(o2net_num_from_nn(nn));
433                 /* this is a bit of a hack.  we only try reconnecting
434                  * when heartbeating starts until we get a connection.
435                  * if that connection then dies we don't try reconnecting.
436                  * the only way to start connecting again is to down
437                  * heartbeat and bring it back up. */
438                 cancel_delayed_work(&nn->nn_connect_expired);
439                 printk(KERN_INFO "o2net: %s " SC_NODEF_FMT "\n",
440                        o2nm_this_node() > sc->sc_node->nd_num ?
441                                 "connected to" : "accepted connection from",
442                        SC_NODEF_ARGS(sc));
443         }
444
445         /* trigger the connecting worker func as long as we're not valid,
446          * it will back off if it shouldn't connect.  This can be called
447          * from node config teardown and so needs to be careful about
448          * the work queue actually being up. */
449         if (!valid && o2net_wq) {
450                 unsigned long delay;
451                 /* delay if we're withing a RECONNECT_DELAY of the
452                  * last attempt */
453                 delay = (nn->nn_last_connect_attempt +
454                          msecs_to_jiffies(o2net_reconnect_delay(NULL)))
455                         - jiffies;
456                 if (delay > msecs_to_jiffies(o2net_reconnect_delay(NULL)))
457                         delay = 0;
458                 mlog(ML_CONN, "queueing conn attempt in %lu jiffies\n", delay);
459                 queue_delayed_work(o2net_wq, &nn->nn_connect_work, delay);
460         }
461
462         /* keep track of the nn's sc ref for the caller */
463         if ((old_sc == NULL) && sc)
464                 sc_get(sc);
465         if (old_sc && (old_sc != sc)) {
466                 o2net_sc_queue_work(old_sc, &old_sc->sc_shutdown_work);
467                 sc_put(old_sc);
468         }
469 }
470
471 /* see o2net_register_callbacks() */
472 static void o2net_data_ready(struct sock *sk, int bytes)
473 {
474         void (*ready)(struct sock *sk, int bytes);
475
476         read_lock(&sk->sk_callback_lock);
477         if (sk->sk_user_data) {
478                 struct o2net_sock_container *sc = sk->sk_user_data;
479                 sclog(sc, "data_ready hit\n");
480                 do_gettimeofday(&sc->sc_tv_data_ready);
481                 o2net_sc_queue_work(sc, &sc->sc_rx_work);
482                 ready = sc->sc_data_ready;
483         } else {
484                 ready = sk->sk_data_ready;
485         }
486         read_unlock(&sk->sk_callback_lock);
487
488         ready(sk, bytes);
489 }
490
491 /* see o2net_register_callbacks() */
492 static void o2net_state_change(struct sock *sk)
493 {
494         void (*state_change)(struct sock *sk);
495         struct o2net_sock_container *sc;
496
497         read_lock(&sk->sk_callback_lock);
498         sc = sk->sk_user_data;
499         if (sc == NULL) {
500                 state_change = sk->sk_state_change;
501                 goto out;
502         }
503
504         sclog(sc, "state_change to %d\n", sk->sk_state);
505
506         state_change = sc->sc_state_change;
507
508         switch(sk->sk_state) {
509                 /* ignore connecting sockets as they make progress */
510                 case TCP_SYN_SENT:
511                 case TCP_SYN_RECV:
512                         break;
513                 case TCP_ESTABLISHED:
514                         o2net_sc_queue_work(sc, &sc->sc_connect_work);
515                         break;
516                 default:
517                         o2net_sc_queue_work(sc, &sc->sc_shutdown_work);
518                         break;
519         }
520 out:
521         read_unlock(&sk->sk_callback_lock);
522         state_change(sk);
523 }
524
525 /*
526  * we register callbacks so we can queue work on events before calling
527  * the original callbacks.  our callbacks our careful to test user_data
528  * to discover when they've reaced with o2net_unregister_callbacks().
529  */
530 static void o2net_register_callbacks(struct sock *sk,
531                                      struct o2net_sock_container *sc)
532 {
533         write_lock_bh(&sk->sk_callback_lock);
534
535         /* accepted sockets inherit the old listen socket data ready */
536         if (sk->sk_data_ready == o2net_listen_data_ready) {
537                 sk->sk_data_ready = sk->sk_user_data;
538                 sk->sk_user_data = NULL;
539         }
540
541         BUG_ON(sk->sk_user_data != NULL);
542         sk->sk_user_data = sc;
543         sc_get(sc);
544
545         sc->sc_data_ready = sk->sk_data_ready;
546         sc->sc_state_change = sk->sk_state_change;
547         sk->sk_data_ready = o2net_data_ready;
548         sk->sk_state_change = o2net_state_change;
549
550         mutex_init(&sc->sc_send_lock);
551
552         write_unlock_bh(&sk->sk_callback_lock);
553 }
554
555 static int o2net_unregister_callbacks(struct sock *sk,
556                                    struct o2net_sock_container *sc)
557 {
558         int ret = 0;
559
560         write_lock_bh(&sk->sk_callback_lock);
561         if (sk->sk_user_data == sc) {
562                 ret = 1;
563                 sk->sk_user_data = NULL;
564                 sk->sk_data_ready = sc->sc_data_ready;
565                 sk->sk_state_change = sc->sc_state_change;
566         }
567         write_unlock_bh(&sk->sk_callback_lock);
568
569         return ret;
570 }
571
572 /*
573  * this is a little helper that is called by callers who have seen a problem
574  * with an sc and want to detach it from the nn if someone already hasn't beat
575  * them to it.  if an error is given then the shutdown will be persistent
576  * and pending transmits will be canceled.
577  */
578 static void o2net_ensure_shutdown(struct o2net_node *nn,
579                                    struct o2net_sock_container *sc,
580                                    int err)
581 {
582         spin_lock(&nn->nn_lock);
583         if (nn->nn_sc == sc)
584                 o2net_set_nn_state(nn, NULL, 0, err);
585         spin_unlock(&nn->nn_lock);
586 }
587
588 /*
589  * This work queue function performs the blocking parts of socket shutdown.  A
590  * few paths lead here.  set_nn_state will trigger this callback if it sees an
591  * sc detached from the nn.  state_change will also trigger this callback
592  * directly when it sees errors.  In that case we need to call set_nn_state
593  * ourselves as state_change couldn't get the nn_lock and call set_nn_state
594  * itself.
595  */
596 static void o2net_shutdown_sc(struct work_struct *work)
597 {
598         struct o2net_sock_container *sc =
599                 container_of(work, struct o2net_sock_container,
600                              sc_shutdown_work);
601         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
602
603         sclog(sc, "shutting down\n");
604
605         /* drop the callbacks ref and call shutdown only once */
606         if (o2net_unregister_callbacks(sc->sc_sock->sk, sc)) {
607                 /* we shouldn't flush as we're in the thread, the
608                  * races with pending sc work structs are harmless */
609                 del_timer_sync(&sc->sc_idle_timeout);
610                 o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
611                 sc_put(sc);
612                 kernel_sock_shutdown(sc->sc_sock, SHUT_RDWR);
613         }
614
615         /* not fatal so failed connects before the other guy has our
616          * heartbeat can be retried */
617         o2net_ensure_shutdown(nn, sc, 0);
618         sc_put(sc);
619 }
620
621 /* ------------------------------------------------------------ */
622
623 static int o2net_handler_cmp(struct o2net_msg_handler *nmh, u32 msg_type,
624                              u32 key)
625 {
626         int ret = memcmp(&nmh->nh_key, &key, sizeof(key));
627
628         if (ret == 0)
629                 ret = memcmp(&nmh->nh_msg_type, &msg_type, sizeof(msg_type));
630
631         return ret;
632 }
633
634 static struct o2net_msg_handler *
635 o2net_handler_tree_lookup(u32 msg_type, u32 key, struct rb_node ***ret_p,
636                           struct rb_node **ret_parent)
637 {
638         struct rb_node **p = &o2net_handler_tree.rb_node;
639         struct rb_node *parent = NULL;
640         struct o2net_msg_handler *nmh, *ret = NULL;
641         int cmp;
642
643         while (*p) {
644                 parent = *p;
645                 nmh = rb_entry(parent, struct o2net_msg_handler, nh_node);
646                 cmp = o2net_handler_cmp(nmh, msg_type, key);
647
648                 if (cmp < 0)
649                         p = &(*p)->rb_left;
650                 else if (cmp > 0)
651                         p = &(*p)->rb_right;
652                 else {
653                         ret = nmh;
654                         break;
655                 }
656         }
657
658         if (ret_p != NULL)
659                 *ret_p = p;
660         if (ret_parent != NULL)
661                 *ret_parent = parent;
662
663         return ret;
664 }
665
666 static void o2net_handler_kref_release(struct kref *kref)
667 {
668         struct o2net_msg_handler *nmh;
669         nmh = container_of(kref, struct o2net_msg_handler, nh_kref);
670
671         kfree(nmh);
672 }
673
674 static void o2net_handler_put(struct o2net_msg_handler *nmh)
675 {
676         kref_put(&nmh->nh_kref, o2net_handler_kref_release);
677 }
678
679 /* max_len is protection for the handler func.  incoming messages won't
680  * be given to the handler if their payload is longer than the max. */
681 int o2net_register_handler(u32 msg_type, u32 key, u32 max_len,
682                            o2net_msg_handler_func *func, void *data,
683                            o2net_post_msg_handler_func *post_func,
684                            struct list_head *unreg_list)
685 {
686         struct o2net_msg_handler *nmh = NULL;
687         struct rb_node **p, *parent;
688         int ret = 0;
689
690         if (max_len > O2NET_MAX_PAYLOAD_BYTES) {
691                 mlog(0, "max_len for message handler out of range: %u\n",
692                         max_len);
693                 ret = -EINVAL;
694                 goto out;
695         }
696
697         if (!msg_type) {
698                 mlog(0, "no message type provided: %u, %p\n", msg_type, func);
699                 ret = -EINVAL;
700                 goto out;
701
702         }
703         if (!func) {
704                 mlog(0, "no message handler provided: %u, %p\n",
705                        msg_type, func);
706                 ret = -EINVAL;
707                 goto out;
708         }
709
710         nmh = kzalloc(sizeof(struct o2net_msg_handler), GFP_NOFS);
711         if (nmh == NULL) {
712                 ret = -ENOMEM;
713                 goto out;
714         }
715
716         nmh->nh_func = func;
717         nmh->nh_func_data = data;
718         nmh->nh_post_func = post_func;
719         nmh->nh_msg_type = msg_type;
720         nmh->nh_max_len = max_len;
721         nmh->nh_key = key;
722         /* the tree and list get this ref.. they're both removed in
723          * unregister when this ref is dropped */
724         kref_init(&nmh->nh_kref);
725         INIT_LIST_HEAD(&nmh->nh_unregister_item);
726
727         write_lock(&o2net_handler_lock);
728         if (o2net_handler_tree_lookup(msg_type, key, &p, &parent))
729                 ret = -EEXIST;
730         else {
731                 rb_link_node(&nmh->nh_node, parent, p);
732                 rb_insert_color(&nmh->nh_node, &o2net_handler_tree);
733                 list_add_tail(&nmh->nh_unregister_item, unreg_list);
734
735                 mlog(ML_TCP, "registered handler func %p type %u key %08x\n",
736                      func, msg_type, key);
737                 /* we've had some trouble with handlers seemingly vanishing. */
738                 mlog_bug_on_msg(o2net_handler_tree_lookup(msg_type, key, &p,
739                                                           &parent) == NULL,
740                                 "couldn't find handler we *just* registerd "
741                                 "for type %u key %08x\n", msg_type, key);
742         }
743         write_unlock(&o2net_handler_lock);
744         if (ret)
745                 goto out;
746
747 out:
748         if (ret)
749                 kfree(nmh);
750
751         return ret;
752 }
753 EXPORT_SYMBOL_GPL(o2net_register_handler);
754
755 void o2net_unregister_handler_list(struct list_head *list)
756 {
757         struct o2net_msg_handler *nmh, *n;
758
759         write_lock(&o2net_handler_lock);
760         list_for_each_entry_safe(nmh, n, list, nh_unregister_item) {
761                 mlog(ML_TCP, "unregistering handler func %p type %u key %08x\n",
762                      nmh->nh_func, nmh->nh_msg_type, nmh->nh_key);
763                 rb_erase(&nmh->nh_node, &o2net_handler_tree);
764                 list_del_init(&nmh->nh_unregister_item);
765                 kref_put(&nmh->nh_kref, o2net_handler_kref_release);
766         }
767         write_unlock(&o2net_handler_lock);
768 }
769 EXPORT_SYMBOL_GPL(o2net_unregister_handler_list);
770
771 static struct o2net_msg_handler *o2net_handler_get(u32 msg_type, u32 key)
772 {
773         struct o2net_msg_handler *nmh;
774
775         read_lock(&o2net_handler_lock);
776         nmh = o2net_handler_tree_lookup(msg_type, key, NULL, NULL);
777         if (nmh)
778                 kref_get(&nmh->nh_kref);
779         read_unlock(&o2net_handler_lock);
780
781         return nmh;
782 }
783
784 /* ------------------------------------------------------------ */
785
786 static int o2net_recv_tcp_msg(struct socket *sock, void *data, size_t len)
787 {
788         int ret;
789         mm_segment_t oldfs;
790         struct kvec vec = {
791                 .iov_len = len,
792                 .iov_base = data,
793         };
794         struct msghdr msg = {
795                 .msg_iovlen = 1,
796                 .msg_iov = (struct iovec *)&vec,
797                 .msg_flags = MSG_DONTWAIT,
798         };
799
800         oldfs = get_fs();
801         set_fs(get_ds());
802         ret = sock_recvmsg(sock, &msg, len, msg.msg_flags);
803         set_fs(oldfs);
804
805         return ret;
806 }
807
808 static int o2net_send_tcp_msg(struct socket *sock, struct kvec *vec,
809                               size_t veclen, size_t total)
810 {
811         int ret;
812         mm_segment_t oldfs;
813         struct msghdr msg = {
814                 .msg_iov = (struct iovec *)vec,
815                 .msg_iovlen = veclen,
816         };
817
818         if (sock == NULL) {
819                 ret = -EINVAL;
820                 goto out;
821         }
822
823         oldfs = get_fs();
824         set_fs(get_ds());
825         ret = sock_sendmsg(sock, &msg, total);
826         set_fs(oldfs);
827         if (ret != total) {
828                 mlog(ML_ERROR, "sendmsg returned %d instead of %zu\n", ret,
829                      total);
830                 if (ret >= 0)
831                         ret = -EPIPE; /* should be smarter, I bet */
832                 goto out;
833         }
834
835         ret = 0;
836 out:
837         if (ret < 0)
838                 mlog(0, "returning error: %d\n", ret);
839         return ret;
840 }
841
842 static void o2net_sendpage(struct o2net_sock_container *sc,
843                            void *kmalloced_virt,
844                            size_t size)
845 {
846         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
847         ssize_t ret;
848
849         while (1) {
850                 mutex_lock(&sc->sc_send_lock);
851                 ret = sc->sc_sock->ops->sendpage(sc->sc_sock,
852                                                  virt_to_page(kmalloced_virt),
853                                                  (long)kmalloced_virt & ~PAGE_MASK,
854                                                  size, MSG_DONTWAIT);
855                 mutex_unlock(&sc->sc_send_lock);
856                 if (ret == size)
857                         break;
858                 if (ret == (ssize_t)-EAGAIN) {
859                         mlog(0, "sendpage of size %zu to " SC_NODEF_FMT
860                              " returned EAGAIN\n", size, SC_NODEF_ARGS(sc));
861                         cond_resched();
862                         continue;
863                 }
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                 break;
868         }
869 }
870
871 static void o2net_init_msg(struct o2net_msg *msg, u16 data_len, u16 msg_type, u32 key)
872 {
873         memset(msg, 0, sizeof(struct o2net_msg));
874         msg->magic = cpu_to_be16(O2NET_MSG_MAGIC);
875         msg->data_len = cpu_to_be16(data_len);
876         msg->msg_type = cpu_to_be16(msg_type);
877         msg->sys_status = cpu_to_be32(O2NET_ERR_NONE);
878         msg->status = 0;
879         msg->key = cpu_to_be32(key);
880 }
881
882 static int o2net_tx_can_proceed(struct o2net_node *nn,
883                                 struct o2net_sock_container **sc_ret,
884                                 int *error)
885 {
886         int ret = 0;
887
888         spin_lock(&nn->nn_lock);
889         if (nn->nn_persistent_error) {
890                 ret = 1;
891                 *sc_ret = NULL;
892                 *error = nn->nn_persistent_error;
893         } else if (nn->nn_sc_valid) {
894                 kref_get(&nn->nn_sc->sc_kref);
895
896                 ret = 1;
897                 *sc_ret = nn->nn_sc;
898                 *error = 0;
899         }
900         spin_unlock(&nn->nn_lock);
901
902         return ret;
903 }
904
905 int o2net_send_message_vec(u32 msg_type, u32 key, struct kvec *caller_vec,
906                            size_t caller_veclen, u8 target_node, int *status)
907 {
908         int ret, error = 0;
909         struct o2net_msg *msg = NULL;
910         size_t veclen, caller_bytes = 0;
911         struct kvec *vec = NULL;
912         struct o2net_sock_container *sc = NULL;
913         struct o2net_node *nn = o2net_nn_from_num(target_node);
914         struct o2net_status_wait nsw = {
915                 .ns_node_item = LIST_HEAD_INIT(nsw.ns_node_item),
916         };
917
918         if (o2net_wq == NULL) {
919                 mlog(0, "attempt to tx without o2netd running\n");
920                 ret = -ESRCH;
921                 goto out;
922         }
923
924         if (caller_veclen == 0) {
925                 mlog(0, "bad kvec array length\n");
926                 ret = -EINVAL;
927                 goto out;
928         }
929
930         caller_bytes = iov_length((struct iovec *)caller_vec, caller_veclen);
931         if (caller_bytes > O2NET_MAX_PAYLOAD_BYTES) {
932                 mlog(0, "total payload len %zu too large\n", caller_bytes);
933                 ret = -EINVAL;
934                 goto out;
935         }
936
937         if (target_node == o2nm_this_node()) {
938                 ret = -ELOOP;
939                 goto out;
940         }
941
942         ret = wait_event_interruptible(nn->nn_sc_wq,
943                                        o2net_tx_can_proceed(nn, &sc, &error));
944         if (!ret && error)
945                 ret = error;
946         if (ret)
947                 goto out;
948
949         veclen = caller_veclen + 1;
950         vec = kmalloc(sizeof(struct kvec) * veclen, GFP_ATOMIC);
951         if (vec == NULL) {
952                 mlog(0, "failed to %zu element kvec!\n", veclen);
953                 ret = -ENOMEM;
954                 goto out;
955         }
956
957         msg = kmalloc(sizeof(struct o2net_msg), GFP_ATOMIC);
958         if (!msg) {
959                 mlog(0, "failed to allocate a o2net_msg!\n");
960                 ret = -ENOMEM;
961                 goto out;
962         }
963
964         o2net_init_msg(msg, caller_bytes, msg_type, key);
965
966         vec[0].iov_len = sizeof(struct o2net_msg);
967         vec[0].iov_base = msg;
968         memcpy(&vec[1], caller_vec, caller_veclen * sizeof(struct kvec));
969
970         ret = o2net_prep_nsw(nn, &nsw);
971         if (ret)
972                 goto out;
973
974         msg->msg_num = cpu_to_be32(nsw.ns_id);
975
976         /* finally, convert the message header to network byte-order
977          * and send */
978         mutex_lock(&sc->sc_send_lock);
979         ret = o2net_send_tcp_msg(sc->sc_sock, vec, veclen,
980                                  sizeof(struct o2net_msg) + caller_bytes);
981         mutex_unlock(&sc->sc_send_lock);
982         msglog(msg, "sending returned %d\n", ret);
983         if (ret < 0) {
984                 mlog(0, "error returned from o2net_send_tcp_msg=%d\n", ret);
985                 goto out;
986         }
987
988         /* wait on other node's handler */
989         wait_event(nsw.ns_wq, o2net_nsw_completed(nn, &nsw));
990
991         /* Note that we avoid overwriting the callers status return
992          * variable if a system error was reported on the other
993          * side. Callers beware. */
994         ret = o2net_sys_err_to_errno(nsw.ns_sys_status);
995         if (status && !ret)
996                 *status = nsw.ns_status;
997
998         mlog(0, "woken, returning system status %d, user status %d\n",
999              ret, nsw.ns_status);
1000 out:
1001         if (sc)
1002                 sc_put(sc);
1003         if (vec)
1004                 kfree(vec);
1005         if (msg)
1006                 kfree(msg);
1007         o2net_complete_nsw(nn, &nsw, 0, 0, 0);
1008         return ret;
1009 }
1010 EXPORT_SYMBOL_GPL(o2net_send_message_vec);
1011
1012 int o2net_send_message(u32 msg_type, u32 key, void *data, u32 len,
1013                        u8 target_node, int *status)
1014 {
1015         struct kvec vec = {
1016                 .iov_base = data,
1017                 .iov_len = len,
1018         };
1019         return o2net_send_message_vec(msg_type, key, &vec, 1,
1020                                       target_node, status);
1021 }
1022 EXPORT_SYMBOL_GPL(o2net_send_message);
1023
1024 static int o2net_send_status_magic(struct socket *sock, struct o2net_msg *hdr,
1025                                    enum o2net_system_error syserr, int err)
1026 {
1027         struct kvec vec = {
1028                 .iov_base = hdr,
1029                 .iov_len = sizeof(struct o2net_msg),
1030         };
1031
1032         BUG_ON(syserr >= O2NET_ERR_MAX);
1033
1034         /* leave other fields intact from the incoming message, msg_num
1035          * in particular */
1036         hdr->sys_status = cpu_to_be32(syserr);
1037         hdr->status = cpu_to_be32(err);
1038         hdr->magic = cpu_to_be16(O2NET_MSG_STATUS_MAGIC);  // twiddle the magic
1039         hdr->data_len = 0;
1040
1041         msglog(hdr, "about to send status magic %d\n", err);
1042         /* hdr has been in host byteorder this whole time */
1043         return o2net_send_tcp_msg(sock, &vec, 1, sizeof(struct o2net_msg));
1044 }
1045
1046 /* this returns -errno if the header was unknown or too large, etc.
1047  * after this is called the buffer us reused for the next message */
1048 static int o2net_process_message(struct o2net_sock_container *sc,
1049                                  struct o2net_msg *hdr)
1050 {
1051         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1052         int ret = 0, handler_status;
1053         enum  o2net_system_error syserr;
1054         struct o2net_msg_handler *nmh = NULL;
1055         void *ret_data = NULL;
1056
1057         msglog(hdr, "processing message\n");
1058
1059         o2net_sc_postpone_idle(sc);
1060
1061         switch(be16_to_cpu(hdr->magic)) {
1062                 case O2NET_MSG_STATUS_MAGIC:
1063                         /* special type for returning message status */
1064                         o2net_complete_nsw(nn, NULL,
1065                                            be32_to_cpu(hdr->msg_num),
1066                                            be32_to_cpu(hdr->sys_status),
1067                                            be32_to_cpu(hdr->status));
1068                         goto out;
1069                 case O2NET_MSG_KEEP_REQ_MAGIC:
1070                         o2net_sendpage(sc, o2net_keep_resp,
1071                                        sizeof(*o2net_keep_resp));
1072                         goto out;
1073                 case O2NET_MSG_KEEP_RESP_MAGIC:
1074                         goto out;
1075                 case O2NET_MSG_MAGIC:
1076                         break;
1077                 default:
1078                         msglog(hdr, "bad magic\n");
1079                         ret = -EINVAL;
1080                         goto out;
1081                         break;
1082         }
1083
1084         /* find a handler for it */
1085         handler_status = 0;
1086         nmh = o2net_handler_get(be16_to_cpu(hdr->msg_type),
1087                                 be32_to_cpu(hdr->key));
1088         if (!nmh) {
1089                 mlog(ML_TCP, "couldn't find handler for type %u key %08x\n",
1090                      be16_to_cpu(hdr->msg_type), be32_to_cpu(hdr->key));
1091                 syserr = O2NET_ERR_NO_HNDLR;
1092                 goto out_respond;
1093         }
1094
1095         syserr = O2NET_ERR_NONE;
1096
1097         if (be16_to_cpu(hdr->data_len) > nmh->nh_max_len)
1098                 syserr = O2NET_ERR_OVERFLOW;
1099
1100         if (syserr != O2NET_ERR_NONE)
1101                 goto out_respond;
1102
1103         do_gettimeofday(&sc->sc_tv_func_start);
1104         sc->sc_msg_key = be32_to_cpu(hdr->key);
1105         sc->sc_msg_type = be16_to_cpu(hdr->msg_type);
1106         handler_status = (nmh->nh_func)(hdr, sizeof(struct o2net_msg) +
1107                                              be16_to_cpu(hdr->data_len),
1108                                         nmh->nh_func_data, &ret_data);
1109         do_gettimeofday(&sc->sc_tv_func_stop);
1110
1111 out_respond:
1112         /* this destroys the hdr, so don't use it after this */
1113         mutex_lock(&sc->sc_send_lock);
1114         ret = o2net_send_status_magic(sc->sc_sock, hdr, syserr,
1115                                       handler_status);
1116         mutex_unlock(&sc->sc_send_lock);
1117         hdr = NULL;
1118         mlog(0, "sending handler status %d, syserr %d returned %d\n",
1119              handler_status, syserr, ret);
1120
1121         if (nmh) {
1122                 BUG_ON(ret_data != NULL && nmh->nh_post_func == NULL);
1123                 if (nmh->nh_post_func)
1124                         (nmh->nh_post_func)(handler_status, nmh->nh_func_data,
1125                                             ret_data);
1126         }
1127
1128 out:
1129         if (nmh)
1130                 o2net_handler_put(nmh);
1131         return ret;
1132 }
1133
1134 static int o2net_check_handshake(struct o2net_sock_container *sc)
1135 {
1136         struct o2net_handshake *hand = page_address(sc->sc_page);
1137         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1138
1139         if (hand->protocol_version != cpu_to_be64(O2NET_PROTOCOL_VERSION)) {
1140                 mlog(ML_NOTICE, SC_NODEF_FMT " advertised net protocol "
1141                      "version %llu but %llu is required, disconnecting\n",
1142                      SC_NODEF_ARGS(sc),
1143                      (unsigned long long)be64_to_cpu(hand->protocol_version),
1144                      O2NET_PROTOCOL_VERSION);
1145
1146                 /* don't bother reconnecting if its the wrong version. */
1147                 o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1148                 return -1;
1149         }
1150
1151         /*
1152          * Ensure timeouts are consistent with other nodes, otherwise
1153          * we can end up with one node thinking that the other must be down,
1154          * but isn't. This can ultimately cause corruption.
1155          */
1156         if (be32_to_cpu(hand->o2net_idle_timeout_ms) !=
1157                                 o2net_idle_timeout(sc->sc_node)) {
1158                 mlog(ML_NOTICE, SC_NODEF_FMT " uses a network idle timeout of "
1159                      "%u ms, but we use %u ms locally.  disconnecting\n",
1160                      SC_NODEF_ARGS(sc),
1161                      be32_to_cpu(hand->o2net_idle_timeout_ms),
1162                      o2net_idle_timeout(sc->sc_node));
1163                 o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1164                 return -1;
1165         }
1166
1167         if (be32_to_cpu(hand->o2net_keepalive_delay_ms) !=
1168                         o2net_keepalive_delay(sc->sc_node)) {
1169                 mlog(ML_NOTICE, SC_NODEF_FMT " uses a keepalive delay of "
1170                      "%u ms, but we use %u ms locally.  disconnecting\n",
1171                      SC_NODEF_ARGS(sc),
1172                      be32_to_cpu(hand->o2net_keepalive_delay_ms),
1173                      o2net_keepalive_delay(sc->sc_node));
1174                 o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1175                 return -1;
1176         }
1177
1178         if (be32_to_cpu(hand->o2hb_heartbeat_timeout_ms) !=
1179                         O2HB_MAX_WRITE_TIMEOUT_MS) {
1180                 mlog(ML_NOTICE, SC_NODEF_FMT " uses a heartbeat timeout of "
1181                      "%u ms, but we use %u ms locally.  disconnecting\n",
1182                      SC_NODEF_ARGS(sc),
1183                      be32_to_cpu(hand->o2hb_heartbeat_timeout_ms),
1184                      O2HB_MAX_WRITE_TIMEOUT_MS);
1185                 o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1186                 return -1;
1187         }
1188
1189         sc->sc_handshake_ok = 1;
1190
1191         spin_lock(&nn->nn_lock);
1192         /* set valid and queue the idle timers only if it hasn't been
1193          * shut down already */
1194         if (nn->nn_sc == sc) {
1195                 o2net_sc_reset_idle_timer(sc);
1196                 o2net_set_nn_state(nn, sc, 1, 0);
1197         }
1198         spin_unlock(&nn->nn_lock);
1199
1200         /* shift everything up as though it wasn't there */
1201         sc->sc_page_off -= sizeof(struct o2net_handshake);
1202         if (sc->sc_page_off)
1203                 memmove(hand, hand + 1, sc->sc_page_off);
1204
1205         return 0;
1206 }
1207
1208 /* this demuxes the queued rx bytes into header or payload bits and calls
1209  * handlers as each full message is read off the socket.  it returns -error,
1210  * == 0 eof, or > 0 for progress made.*/
1211 static int o2net_advance_rx(struct o2net_sock_container *sc)
1212 {
1213         struct o2net_msg *hdr;
1214         int ret = 0;
1215         void *data;
1216         size_t datalen;
1217
1218         sclog(sc, "receiving\n");
1219         do_gettimeofday(&sc->sc_tv_advance_start);
1220
1221         if (unlikely(sc->sc_handshake_ok == 0)) {
1222                 if(sc->sc_page_off < sizeof(struct o2net_handshake)) {
1223                         data = page_address(sc->sc_page) + sc->sc_page_off;
1224                         datalen = sizeof(struct o2net_handshake) - sc->sc_page_off;
1225                         ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1226                         if (ret > 0)
1227                                 sc->sc_page_off += ret;
1228                 }
1229
1230                 if (sc->sc_page_off == sizeof(struct o2net_handshake)) {
1231                         o2net_check_handshake(sc);
1232                         if (unlikely(sc->sc_handshake_ok == 0))
1233                                 ret = -EPROTO;
1234                 }
1235                 goto out;
1236         }
1237
1238         /* do we need more header? */
1239         if (sc->sc_page_off < sizeof(struct o2net_msg)) {
1240                 data = page_address(sc->sc_page) + sc->sc_page_off;
1241                 datalen = sizeof(struct o2net_msg) - sc->sc_page_off;
1242                 ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1243                 if (ret > 0) {
1244                         sc->sc_page_off += ret;
1245                         /* only swab incoming here.. we can
1246                          * only get here once as we cross from
1247                          * being under to over */
1248                         if (sc->sc_page_off == sizeof(struct o2net_msg)) {
1249                                 hdr = page_address(sc->sc_page);
1250                                 if (be16_to_cpu(hdr->data_len) >
1251                                     O2NET_MAX_PAYLOAD_BYTES)
1252                                         ret = -EOVERFLOW;
1253                         }
1254                 }
1255                 if (ret <= 0)
1256                         goto out;
1257         }
1258
1259         if (sc->sc_page_off < sizeof(struct o2net_msg)) {
1260                 /* oof, still don't have a header */
1261                 goto out;
1262         }
1263
1264         /* this was swabbed above when we first read it */
1265         hdr = page_address(sc->sc_page);
1266
1267         msglog(hdr, "at page_off %zu\n", sc->sc_page_off);
1268
1269         /* do we need more payload? */
1270         if (sc->sc_page_off - sizeof(struct o2net_msg) < be16_to_cpu(hdr->data_len)) {
1271                 /* need more payload */
1272                 data = page_address(sc->sc_page) + sc->sc_page_off;
1273                 datalen = (sizeof(struct o2net_msg) + be16_to_cpu(hdr->data_len)) -
1274                           sc->sc_page_off;
1275                 ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1276                 if (ret > 0)
1277                         sc->sc_page_off += ret;
1278                 if (ret <= 0)
1279                         goto out;
1280         }
1281
1282         if (sc->sc_page_off - sizeof(struct o2net_msg) == be16_to_cpu(hdr->data_len)) {
1283                 /* we can only get here once, the first time we read
1284                  * the payload.. so set ret to progress if the handler
1285                  * works out. after calling this the message is toast */
1286                 ret = o2net_process_message(sc, hdr);
1287                 if (ret == 0)
1288                         ret = 1;
1289                 sc->sc_page_off = 0;
1290         }
1291
1292 out:
1293         sclog(sc, "ret = %d\n", ret);
1294         do_gettimeofday(&sc->sc_tv_advance_stop);
1295         return ret;
1296 }
1297
1298 /* this work func is triggerd by data ready.  it reads until it can read no
1299  * more.  it interprets 0, eof, as fatal.  if data_ready hits while we're doing
1300  * our work the work struct will be marked and we'll be called again. */
1301 static void o2net_rx_until_empty(struct work_struct *work)
1302 {
1303         struct o2net_sock_container *sc =
1304                 container_of(work, struct o2net_sock_container, sc_rx_work);
1305         int ret;
1306
1307         do {
1308                 ret = o2net_advance_rx(sc);
1309         } while (ret > 0);
1310
1311         if (ret <= 0 && ret != -EAGAIN) {
1312                 struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1313                 sclog(sc, "saw error %d, closing\n", ret);
1314                 /* not permanent so read failed handshake can retry */
1315                 o2net_ensure_shutdown(nn, sc, 0);
1316         }
1317
1318         sc_put(sc);
1319 }
1320
1321 static int o2net_set_nodelay(struct socket *sock)
1322 {
1323         int ret, val = 1;
1324         mm_segment_t oldfs;
1325
1326         oldfs = get_fs();
1327         set_fs(KERNEL_DS);
1328
1329         /*
1330          * Dear unsuspecting programmer,
1331          *
1332          * Don't use sock_setsockopt() for SOL_TCP.  It doesn't check its level
1333          * argument and assumes SOL_SOCKET so, say, your TCP_NODELAY will
1334          * silently turn into SO_DEBUG.
1335          *
1336          * Yours,
1337          * Keeper of hilariously fragile interfaces.
1338          */
1339         ret = sock->ops->setsockopt(sock, SOL_TCP, TCP_NODELAY,
1340                                     (char __user *)&val, sizeof(val));
1341
1342         set_fs(oldfs);
1343         return ret;
1344 }
1345
1346 static void o2net_initialize_handshake(void)
1347 {
1348         o2net_hand->o2hb_heartbeat_timeout_ms = cpu_to_be32(
1349                 O2HB_MAX_WRITE_TIMEOUT_MS);
1350         o2net_hand->o2net_idle_timeout_ms = cpu_to_be32(
1351                 o2net_idle_timeout(NULL));
1352         o2net_hand->o2net_keepalive_delay_ms = cpu_to_be32(
1353                 o2net_keepalive_delay(NULL));
1354         o2net_hand->o2net_reconnect_delay_ms = cpu_to_be32(
1355                 o2net_reconnect_delay(NULL));
1356 }
1357
1358 /* ------------------------------------------------------------ */
1359
1360 /* called when a connect completes and after a sock is accepted.  the
1361  * rx path will see the response and mark the sc valid */
1362 static void o2net_sc_connect_completed(struct work_struct *work)
1363 {
1364         struct o2net_sock_container *sc =
1365                 container_of(work, struct o2net_sock_container,
1366                              sc_connect_work);
1367
1368         mlog(ML_MSG, "sc sending handshake with ver %llu id %llx\n",
1369               (unsigned long long)O2NET_PROTOCOL_VERSION,
1370               (unsigned long long)be64_to_cpu(o2net_hand->connector_id));
1371
1372         o2net_initialize_handshake();
1373         o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
1374         sc_put(sc);
1375 }
1376
1377 /* this is called as a work_struct func. */
1378 static void o2net_sc_send_keep_req(struct work_struct *work)
1379 {
1380         struct o2net_sock_container *sc =
1381                 container_of(work, struct o2net_sock_container,
1382                              sc_keepalive_work.work);
1383
1384         o2net_sendpage(sc, o2net_keep_req, sizeof(*o2net_keep_req));
1385         sc_put(sc);
1386 }
1387
1388 /* socket shutdown does a del_timer_sync against this as it tears down.
1389  * we can't start this timer until we've got to the point in sc buildup
1390  * where shutdown is going to be involved */
1391 static void o2net_idle_timer(unsigned long data)
1392 {
1393         struct o2net_sock_container *sc = (struct o2net_sock_container *)data;
1394         struct timeval now;
1395
1396         do_gettimeofday(&now);
1397
1398         printk(KERN_INFO "o2net: connection to " SC_NODEF_FMT " has been idle for %u.%u "
1399              "seconds, shutting it down.\n", SC_NODEF_ARGS(sc),
1400                      o2net_idle_timeout(sc->sc_node) / 1000,
1401                      o2net_idle_timeout(sc->sc_node) % 1000);
1402         mlog(ML_NOTICE, "here are some times that might help debug the "
1403              "situation: (tmr %ld.%ld now %ld.%ld dr %ld.%ld adv "
1404              "%ld.%ld:%ld.%ld func (%08x:%u) %ld.%ld:%ld.%ld)\n",
1405              sc->sc_tv_timer.tv_sec, (long) sc->sc_tv_timer.tv_usec, 
1406              now.tv_sec, (long) now.tv_usec,
1407              sc->sc_tv_data_ready.tv_sec, (long) sc->sc_tv_data_ready.tv_usec,
1408              sc->sc_tv_advance_start.tv_sec,
1409              (long) sc->sc_tv_advance_start.tv_usec,
1410              sc->sc_tv_advance_stop.tv_sec,
1411              (long) sc->sc_tv_advance_stop.tv_usec,
1412              sc->sc_msg_key, sc->sc_msg_type,
1413              sc->sc_tv_func_start.tv_sec, (long) sc->sc_tv_func_start.tv_usec,
1414              sc->sc_tv_func_stop.tv_sec, (long) sc->sc_tv_func_stop.tv_usec);
1415
1416         o2net_sc_queue_work(sc, &sc->sc_shutdown_work);
1417 }
1418
1419 static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc)
1420 {
1421         o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
1422         o2net_sc_queue_delayed_work(sc, &sc->sc_keepalive_work,
1423                       msecs_to_jiffies(o2net_keepalive_delay(sc->sc_node)));
1424         do_gettimeofday(&sc->sc_tv_timer);
1425         mod_timer(&sc->sc_idle_timeout,
1426                jiffies + msecs_to_jiffies(o2net_idle_timeout(sc->sc_node)));
1427 }
1428
1429 static void o2net_sc_postpone_idle(struct o2net_sock_container *sc)
1430 {
1431         /* Only push out an existing timer */
1432         if (timer_pending(&sc->sc_idle_timeout))
1433                 o2net_sc_reset_idle_timer(sc);
1434 }
1435
1436 /* this work func is kicked whenever a path sets the nn state which doesn't
1437  * have valid set.  This includes seeing hb come up, losing a connection,
1438  * having a connect attempt fail, etc. This centralizes the logic which decides
1439  * if a connect attempt should be made or if we should give up and all future
1440  * transmit attempts should fail */
1441 static void o2net_start_connect(struct work_struct *work)
1442 {
1443         struct o2net_node *nn =
1444                 container_of(work, struct o2net_node, nn_connect_work.work);
1445         struct o2net_sock_container *sc = NULL;
1446         struct o2nm_node *node = NULL, *mynode = NULL;
1447         struct socket *sock = NULL;
1448         struct sockaddr_in myaddr = {0, }, remoteaddr = {0, };
1449         int ret = 0, stop;
1450
1451         /* if we're greater we initiate tx, otherwise we accept */
1452         if (o2nm_this_node() <= o2net_num_from_nn(nn))
1453                 goto out;
1454
1455         /* watch for racing with tearing a node down */
1456         node = o2nm_get_node_by_num(o2net_num_from_nn(nn));
1457         if (node == NULL) {
1458                 ret = 0;
1459                 goto out;
1460         }
1461
1462         mynode = o2nm_get_node_by_num(o2nm_this_node());
1463         if (mynode == NULL) {
1464                 ret = 0;
1465                 goto out;
1466         }
1467
1468         spin_lock(&nn->nn_lock);
1469         /* see if we already have one pending or have given up */
1470         stop = (nn->nn_sc || nn->nn_persistent_error);
1471         spin_unlock(&nn->nn_lock);
1472         if (stop)
1473                 goto out;
1474
1475         nn->nn_last_connect_attempt = jiffies;
1476
1477         sc = sc_alloc(node);
1478         if (sc == NULL) {
1479                 mlog(0, "couldn't allocate sc\n");
1480                 ret = -ENOMEM;
1481                 goto out;
1482         }
1483
1484         ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
1485         if (ret < 0) {
1486                 mlog(0, "can't create socket: %d\n", ret);
1487                 goto out;
1488         }
1489         sc->sc_sock = sock; /* freed by sc_kref_release */
1490
1491         sock->sk->sk_allocation = GFP_ATOMIC;
1492
1493         myaddr.sin_family = AF_INET;
1494         myaddr.sin_addr.s_addr = mynode->nd_ipv4_address;
1495         myaddr.sin_port = htons(0); /* any port */
1496
1497         ret = sock->ops->bind(sock, (struct sockaddr *)&myaddr,
1498                               sizeof(myaddr));
1499         if (ret) {
1500                 mlog(ML_ERROR, "bind failed with %d at address %u.%u.%u.%u\n",
1501                      ret, NIPQUAD(mynode->nd_ipv4_address));
1502                 goto out;
1503         }
1504
1505         ret = o2net_set_nodelay(sc->sc_sock);
1506         if (ret) {
1507                 mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret);
1508                 goto out;
1509         }
1510
1511         o2net_register_callbacks(sc->sc_sock->sk, sc);
1512
1513         spin_lock(&nn->nn_lock);
1514         /* handshake completion will set nn->nn_sc_valid */
1515         o2net_set_nn_state(nn, sc, 0, 0);
1516         spin_unlock(&nn->nn_lock);
1517
1518         remoteaddr.sin_family = AF_INET;
1519         remoteaddr.sin_addr.s_addr = node->nd_ipv4_address;
1520         remoteaddr.sin_port = node->nd_ipv4_port;
1521
1522         ret = sc->sc_sock->ops->connect(sc->sc_sock,
1523                                         (struct sockaddr *)&remoteaddr,
1524                                         sizeof(remoteaddr),
1525                                         O_NONBLOCK);
1526         if (ret == -EINPROGRESS)
1527                 ret = 0;
1528
1529 out:
1530         if (ret) {
1531                 mlog(ML_NOTICE, "connect attempt to " SC_NODEF_FMT " failed "
1532                      "with errno %d\n", SC_NODEF_ARGS(sc), ret);
1533                 /* 0 err so that another will be queued and attempted
1534                  * from set_nn_state */
1535                 if (sc)
1536                         o2net_ensure_shutdown(nn, sc, 0);
1537         }
1538         if (sc)
1539                 sc_put(sc);
1540         if (node)
1541                 o2nm_node_put(node);
1542         if (mynode)
1543                 o2nm_node_put(mynode);
1544
1545         return;
1546 }
1547
1548 static void o2net_connect_expired(struct work_struct *work)
1549 {
1550         struct o2net_node *nn =
1551                 container_of(work, struct o2net_node, nn_connect_expired.work);
1552
1553         spin_lock(&nn->nn_lock);
1554         if (!nn->nn_sc_valid) {
1555                 mlog(ML_ERROR, "no connection established with node %u after "
1556                      "%u.%u seconds, giving up and returning errors.\n",
1557                      o2net_num_from_nn(nn),
1558                      o2net_idle_timeout(NULL) / 1000,
1559                      o2net_idle_timeout(NULL) % 1000);
1560
1561                 o2net_set_nn_state(nn, NULL, 0, -ENOTCONN);
1562         }
1563         spin_unlock(&nn->nn_lock);
1564 }
1565
1566 static void o2net_still_up(struct work_struct *work)
1567 {
1568         struct o2net_node *nn =
1569                 container_of(work, struct o2net_node, nn_still_up.work);
1570
1571         o2quo_hb_still_up(o2net_num_from_nn(nn));
1572 }
1573
1574 /* ------------------------------------------------------------ */
1575
1576 void o2net_disconnect_node(struct o2nm_node *node)
1577 {
1578         struct o2net_node *nn = o2net_nn_from_num(node->nd_num);
1579
1580         /* don't reconnect until it's heartbeating again */
1581         spin_lock(&nn->nn_lock);
1582         o2net_set_nn_state(nn, NULL, 0, -ENOTCONN);
1583         spin_unlock(&nn->nn_lock);
1584
1585         if (o2net_wq) {
1586                 cancel_delayed_work(&nn->nn_connect_expired);
1587                 cancel_delayed_work(&nn->nn_connect_work);
1588                 cancel_delayed_work(&nn->nn_still_up);
1589                 flush_workqueue(o2net_wq);
1590         }
1591 }
1592
1593 static void o2net_hb_node_down_cb(struct o2nm_node *node, int node_num,
1594                                   void *data)
1595 {
1596         o2quo_hb_down(node_num);
1597
1598         if (node_num != o2nm_this_node())
1599                 o2net_disconnect_node(node);
1600
1601         BUG_ON(atomic_read(&o2net_connected_peers) < 0);
1602 }
1603
1604 static void o2net_hb_node_up_cb(struct o2nm_node *node, int node_num,
1605                                 void *data)
1606 {
1607         struct o2net_node *nn = o2net_nn_from_num(node_num);
1608
1609         o2quo_hb_up(node_num);
1610
1611         /* ensure an immediate connect attempt */
1612         nn->nn_last_connect_attempt = jiffies -
1613                 (msecs_to_jiffies(o2net_reconnect_delay(node)) + 1);
1614
1615         if (node_num != o2nm_this_node()) {
1616                 /* heartbeat doesn't work unless a local node number is
1617                  * configured and doing so brings up the o2net_wq, so we can
1618                  * use it.. */
1619                 queue_delayed_work(o2net_wq, &nn->nn_connect_expired,
1620                                    msecs_to_jiffies(o2net_idle_timeout(node)));
1621
1622                 /* believe it or not, accept and node hearbeating testing
1623                  * can succeed for this node before we got here.. so
1624                  * only use set_nn_state to clear the persistent error
1625                  * if that hasn't already happened */
1626                 spin_lock(&nn->nn_lock);
1627                 if (nn->nn_persistent_error)
1628                         o2net_set_nn_state(nn, NULL, 0, 0);
1629                 spin_unlock(&nn->nn_lock);
1630         }
1631 }
1632
1633 void o2net_unregister_hb_callbacks(void)
1634 {
1635         o2hb_unregister_callback(NULL, &o2net_hb_up);
1636         o2hb_unregister_callback(NULL, &o2net_hb_down);
1637 }
1638
1639 int o2net_register_hb_callbacks(void)
1640 {
1641         int ret;
1642
1643         o2hb_setup_callback(&o2net_hb_down, O2HB_NODE_DOWN_CB,
1644                             o2net_hb_node_down_cb, NULL, O2NET_HB_PRI);
1645         o2hb_setup_callback(&o2net_hb_up, O2HB_NODE_UP_CB,
1646                             o2net_hb_node_up_cb, NULL, O2NET_HB_PRI);
1647
1648         ret = o2hb_register_callback(NULL, &o2net_hb_up);
1649         if (ret == 0)
1650                 ret = o2hb_register_callback(NULL, &o2net_hb_down);
1651
1652         if (ret)
1653                 o2net_unregister_hb_callbacks();
1654
1655         return ret;
1656 }
1657
1658 /* ------------------------------------------------------------ */
1659
1660 static int o2net_accept_one(struct socket *sock)
1661 {
1662         int ret, slen;
1663         struct sockaddr_in sin;
1664         struct socket *new_sock = NULL;
1665         struct o2nm_node *node = NULL;
1666         struct o2net_sock_container *sc = NULL;
1667         struct o2net_node *nn;
1668
1669         BUG_ON(sock == NULL);
1670         ret = sock_create_lite(sock->sk->sk_family, sock->sk->sk_type,
1671                                sock->sk->sk_protocol, &new_sock);
1672         if (ret)
1673                 goto out;
1674
1675         new_sock->type = sock->type;
1676         new_sock->ops = sock->ops;
1677         ret = sock->ops->accept(sock, new_sock, O_NONBLOCK);
1678         if (ret < 0)
1679                 goto out;
1680
1681         new_sock->sk->sk_allocation = GFP_ATOMIC;
1682
1683         ret = o2net_set_nodelay(new_sock);
1684         if (ret) {
1685                 mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret);
1686                 goto out;
1687         }
1688
1689         slen = sizeof(sin);
1690         ret = new_sock->ops->getname(new_sock, (struct sockaddr *) &sin,
1691                                        &slen, 1);
1692         if (ret < 0)
1693                 goto out;
1694
1695         node = o2nm_get_node_by_ip(sin.sin_addr.s_addr);
1696         if (node == NULL) {
1697                 mlog(ML_NOTICE, "attempt to connect from unknown node at "
1698                      "%u.%u.%u.%u:%d\n", NIPQUAD(sin.sin_addr.s_addr),
1699                      ntohs(sin.sin_port));
1700                 ret = -EINVAL;
1701                 goto out;
1702         }
1703
1704         if (o2nm_this_node() > node->nd_num) {
1705                 mlog(ML_NOTICE, "unexpected connect attempted from a lower "
1706                      "numbered node '%s' at " "%u.%u.%u.%u:%d with num %u\n",
1707                      node->nd_name, NIPQUAD(sin.sin_addr.s_addr),
1708                      ntohs(sin.sin_port), node->nd_num);
1709                 ret = -EINVAL;
1710                 goto out;
1711         }
1712
1713         /* this happens all the time when the other node sees our heartbeat
1714          * and tries to connect before we see their heartbeat */
1715         if (!o2hb_check_node_heartbeating_from_callback(node->nd_num)) {
1716                 mlog(ML_CONN, "attempt to connect from node '%s' at "
1717                      "%u.%u.%u.%u:%d but it isn't heartbeating\n",
1718                      node->nd_name, NIPQUAD(sin.sin_addr.s_addr),
1719                      ntohs(sin.sin_port));
1720                 ret = -EINVAL;
1721                 goto out;
1722         }
1723
1724         nn = o2net_nn_from_num(node->nd_num);
1725
1726         spin_lock(&nn->nn_lock);
1727         if (nn->nn_sc)
1728                 ret = -EBUSY;
1729         else
1730                 ret = 0;
1731         spin_unlock(&nn->nn_lock);
1732         if (ret) {
1733                 mlog(ML_NOTICE, "attempt to connect from node '%s' at "
1734                      "%u.%u.%u.%u:%d but it already has an open connection\n",
1735                      node->nd_name, NIPQUAD(sin.sin_addr.s_addr),
1736                      ntohs(sin.sin_port));
1737                 goto out;
1738         }
1739
1740         sc = sc_alloc(node);
1741         if (sc == NULL) {
1742                 ret = -ENOMEM;
1743                 goto out;
1744         }
1745
1746         sc->sc_sock = new_sock;
1747         new_sock = NULL;
1748
1749         spin_lock(&nn->nn_lock);
1750         o2net_set_nn_state(nn, sc, 0, 0);
1751         spin_unlock(&nn->nn_lock);
1752
1753         o2net_register_callbacks(sc->sc_sock->sk, sc);
1754         o2net_sc_queue_work(sc, &sc->sc_rx_work);
1755
1756         o2net_initialize_handshake();
1757         o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
1758
1759 out:
1760         if (new_sock)
1761                 sock_release(new_sock);
1762         if (node)
1763                 o2nm_node_put(node);
1764         if (sc)
1765                 sc_put(sc);
1766         return ret;
1767 }
1768
1769 static void o2net_accept_many(struct work_struct *work)
1770 {
1771         struct socket *sock = o2net_listen_sock;
1772         while (o2net_accept_one(sock) == 0)
1773                 cond_resched();
1774 }
1775
1776 static void o2net_listen_data_ready(struct sock *sk, int bytes)
1777 {
1778         void (*ready)(struct sock *sk, int bytes);
1779
1780         read_lock(&sk->sk_callback_lock);
1781         ready = sk->sk_user_data;
1782         if (ready == NULL) { /* check for teardown race */
1783                 ready = sk->sk_data_ready;
1784                 goto out;
1785         }
1786
1787         /* ->sk_data_ready is also called for a newly established child socket
1788          * before it has been accepted and the acceptor has set up their
1789          * data_ready.. we only want to queue listen work for our listening
1790          * socket */
1791         if (sk->sk_state == TCP_LISTEN) {
1792                 mlog(ML_TCP, "bytes: %d\n", bytes);
1793                 queue_work(o2net_wq, &o2net_listen_work);
1794         }
1795
1796 out:
1797         read_unlock(&sk->sk_callback_lock);
1798         ready(sk, bytes);
1799 }
1800
1801 static int o2net_open_listening_sock(__be32 addr, __be16 port)
1802 {
1803         struct socket *sock = NULL;
1804         int ret;
1805         struct sockaddr_in sin = {
1806                 .sin_family = PF_INET,
1807                 .sin_addr = { .s_addr = addr },
1808                 .sin_port = port,
1809         };
1810
1811         ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
1812         if (ret < 0) {
1813                 mlog(ML_ERROR, "unable to create socket, ret=%d\n", ret);
1814                 goto out;
1815         }
1816
1817         sock->sk->sk_allocation = GFP_ATOMIC;
1818
1819         write_lock_bh(&sock->sk->sk_callback_lock);
1820         sock->sk->sk_user_data = sock->sk->sk_data_ready;
1821         sock->sk->sk_data_ready = o2net_listen_data_ready;
1822         write_unlock_bh(&sock->sk->sk_callback_lock);
1823
1824         o2net_listen_sock = sock;
1825         INIT_WORK(&o2net_listen_work, o2net_accept_many);
1826
1827         sock->sk->sk_reuse = 1;
1828         ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
1829         if (ret < 0) {
1830                 mlog(ML_ERROR, "unable to bind socket at %u.%u.%u.%u:%u, "
1831                      "ret=%d\n", NIPQUAD(addr), ntohs(port), ret);
1832                 goto out;
1833         }
1834
1835         ret = sock->ops->listen(sock, 64);
1836         if (ret < 0) {
1837                 mlog(ML_ERROR, "unable to listen on %u.%u.%u.%u:%u, ret=%d\n",
1838                      NIPQUAD(addr), ntohs(port), ret);
1839         }
1840
1841 out:
1842         if (ret) {
1843                 o2net_listen_sock = NULL;
1844                 if (sock)
1845                         sock_release(sock);
1846         }
1847         return ret;
1848 }
1849
1850 /*
1851  * called from node manager when we should bring up our network listening
1852  * socket.  node manager handles all the serialization to only call this
1853  * once and to match it with o2net_stop_listening().  note,
1854  * o2nm_this_node() doesn't work yet as we're being called while it
1855  * is being set up.
1856  */
1857 int o2net_start_listening(struct o2nm_node *node)
1858 {
1859         int ret = 0;
1860
1861         BUG_ON(o2net_wq != NULL);
1862         BUG_ON(o2net_listen_sock != NULL);
1863
1864         mlog(ML_KTHREAD, "starting o2net thread...\n");
1865         o2net_wq = create_singlethread_workqueue("o2net");
1866         if (o2net_wq == NULL) {
1867                 mlog(ML_ERROR, "unable to launch o2net thread\n");
1868                 return -ENOMEM; /* ? */
1869         }
1870
1871         ret = o2net_open_listening_sock(node->nd_ipv4_address,
1872                                         node->nd_ipv4_port);
1873         if (ret) {
1874                 destroy_workqueue(o2net_wq);
1875                 o2net_wq = NULL;
1876         } else
1877                 o2quo_conn_up(node->nd_num);
1878
1879         return ret;
1880 }
1881
1882 /* again, o2nm_this_node() doesn't work here as we're involved in
1883  * tearing it down */
1884 void o2net_stop_listening(struct o2nm_node *node)
1885 {
1886         struct socket *sock = o2net_listen_sock;
1887         size_t i;
1888
1889         BUG_ON(o2net_wq == NULL);
1890         BUG_ON(o2net_listen_sock == NULL);
1891
1892         /* stop the listening socket from generating work */
1893         write_lock_bh(&sock->sk->sk_callback_lock);
1894         sock->sk->sk_data_ready = sock->sk->sk_user_data;
1895         sock->sk->sk_user_data = NULL;
1896         write_unlock_bh(&sock->sk->sk_callback_lock);
1897
1898         for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
1899                 struct o2nm_node *node = o2nm_get_node_by_num(i);
1900                 if (node) {
1901                         o2net_disconnect_node(node);
1902                         o2nm_node_put(node);
1903                 }
1904         }
1905
1906         /* finish all work and tear down the work queue */
1907         mlog(ML_KTHREAD, "waiting for o2net thread to exit....\n");
1908         destroy_workqueue(o2net_wq);
1909         o2net_wq = NULL;
1910
1911         sock_release(o2net_listen_sock);
1912         o2net_listen_sock = NULL;
1913
1914         o2quo_conn_err(node->nd_num);
1915 }
1916
1917 /* ------------------------------------------------------------ */
1918
1919 int o2net_init(void)
1920 {
1921         unsigned long i;
1922
1923         o2quo_init();
1924
1925         o2net_hand = kzalloc(sizeof(struct o2net_handshake), GFP_KERNEL);
1926         o2net_keep_req = kzalloc(sizeof(struct o2net_msg), GFP_KERNEL);
1927         o2net_keep_resp = kzalloc(sizeof(struct o2net_msg), GFP_KERNEL);
1928         if (!o2net_hand || !o2net_keep_req || !o2net_keep_resp) {
1929                 kfree(o2net_hand);
1930                 kfree(o2net_keep_req);
1931                 kfree(o2net_keep_resp);
1932                 return -ENOMEM;
1933         }
1934
1935         o2net_hand->protocol_version = cpu_to_be64(O2NET_PROTOCOL_VERSION);
1936         o2net_hand->connector_id = cpu_to_be64(1);
1937
1938         o2net_keep_req->magic = cpu_to_be16(O2NET_MSG_KEEP_REQ_MAGIC);
1939         o2net_keep_resp->magic = cpu_to_be16(O2NET_MSG_KEEP_RESP_MAGIC);
1940
1941         for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
1942                 struct o2net_node *nn = o2net_nn_from_num(i);
1943
1944                 spin_lock_init(&nn->nn_lock);
1945                 INIT_DELAYED_WORK(&nn->nn_connect_work, o2net_start_connect);
1946                 INIT_DELAYED_WORK(&nn->nn_connect_expired,
1947                                   o2net_connect_expired);
1948                 INIT_DELAYED_WORK(&nn->nn_still_up, o2net_still_up);
1949                 /* until we see hb from a node we'll return einval */
1950                 nn->nn_persistent_error = -ENOTCONN;
1951                 init_waitqueue_head(&nn->nn_sc_wq);
1952                 idr_init(&nn->nn_status_idr);
1953                 INIT_LIST_HEAD(&nn->nn_status_list);
1954         }
1955
1956         return 0;
1957 }
1958
1959 void o2net_exit(void)
1960 {
1961         o2quo_exit();
1962         kfree(o2net_hand);
1963         kfree(o2net_keep_req);
1964         kfree(o2net_keep_resp);
1965 }