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TOMOYO Linux Cross Reference
Linux/fs/ocfs2/cluster/tcp.c

Version: ~ [ linux-5.0-rc6 ] ~ [ linux-4.20.10 ] ~ [ linux-4.19.23 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.101 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.158 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.174 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.134 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.63 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.39.4 ] ~ [ linux-2.6.38.8 ] ~ [ linux-2.6.37.6 ] ~ [ linux-2.6.36.4 ] ~ [ linux-2.6.35.14 ] ~ [ linux-2.6.34.15 ] ~ [ linux-2.6.33.20 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 %pI4:%u"
 76 #define SC_NODEF_ARGS(sc) sc->sc_node->nd_name, sc->sc_node->nd_num,    \
 77                           &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 #ifdef CONFIG_DEBUG_FS
146 static void o2net_init_nst(struct o2net_send_tracking *nst, u32 msgtype,
147                            u32 msgkey, struct task_struct *task, u8 node)
148 {
149         INIT_LIST_HEAD(&nst->st_net_debug_item);
150         nst->st_task = task;
151         nst->st_msg_type = msgtype;
152         nst->st_msg_key = msgkey;
153         nst->st_node = node;
154 }
155 
156 static inline void o2net_set_nst_sock_time(struct o2net_send_tracking *nst)
157 {
158         nst->st_sock_time = ktime_get();
159 }
160 
161 static inline void o2net_set_nst_send_time(struct o2net_send_tracking *nst)
162 {
163         nst->st_send_time = ktime_get();
164 }
165 
166 static inline void o2net_set_nst_status_time(struct o2net_send_tracking *nst)
167 {
168         nst->st_status_time = ktime_get();
169 }
170 
171 static inline void o2net_set_nst_sock_container(struct o2net_send_tracking *nst,
172                                                 struct o2net_sock_container *sc)
173 {
174         nst->st_sc = sc;
175 }
176 
177 static inline void o2net_set_nst_msg_id(struct o2net_send_tracking *nst,
178                                         u32 msg_id)
179 {
180         nst->st_id = msg_id;
181 }
182 
183 static inline void o2net_set_sock_timer(struct o2net_sock_container *sc)
184 {
185         sc->sc_tv_timer = ktime_get();
186 }
187 
188 static inline void o2net_set_data_ready_time(struct o2net_sock_container *sc)
189 {
190         sc->sc_tv_data_ready = ktime_get();
191 }
192 
193 static inline void o2net_set_advance_start_time(struct o2net_sock_container *sc)
194 {
195         sc->sc_tv_advance_start = ktime_get();
196 }
197 
198 static inline void o2net_set_advance_stop_time(struct o2net_sock_container *sc)
199 {
200         sc->sc_tv_advance_stop = ktime_get();
201 }
202 
203 static inline void o2net_set_func_start_time(struct o2net_sock_container *sc)
204 {
205         sc->sc_tv_func_start = ktime_get();
206 }
207 
208 static inline void o2net_set_func_stop_time(struct o2net_sock_container *sc)
209 {
210         sc->sc_tv_func_stop = ktime_get();
211 }
212 
213 #else  /* CONFIG_DEBUG_FS */
214 # define o2net_init_nst(a, b, c, d, e)
215 # define o2net_set_nst_sock_time(a)
216 # define o2net_set_nst_send_time(a)
217 # define o2net_set_nst_status_time(a)
218 # define o2net_set_nst_sock_container(a, b)
219 # define o2net_set_nst_msg_id(a, b)
220 # define o2net_set_sock_timer(a)
221 # define o2net_set_data_ready_time(a)
222 # define o2net_set_advance_start_time(a)
223 # define o2net_set_advance_stop_time(a)
224 # define o2net_set_func_start_time(a)
225 # define o2net_set_func_stop_time(a)
226 #endif /* CONFIG_DEBUG_FS */
227 
228 #ifdef CONFIG_OCFS2_FS_STATS
229 static ktime_t o2net_get_func_run_time(struct o2net_sock_container *sc)
230 {
231         return ktime_sub(sc->sc_tv_func_stop, sc->sc_tv_func_start);
232 }
233 
234 static void o2net_update_send_stats(struct o2net_send_tracking *nst,
235                                     struct o2net_sock_container *sc)
236 {
237         sc->sc_tv_status_total = ktime_add(sc->sc_tv_status_total,
238                                            ktime_sub(ktime_get(),
239                                                      nst->st_status_time));
240         sc->sc_tv_send_total = ktime_add(sc->sc_tv_send_total,
241                                          ktime_sub(nst->st_status_time,
242                                                    nst->st_send_time));
243         sc->sc_tv_acquiry_total = ktime_add(sc->sc_tv_acquiry_total,
244                                             ktime_sub(nst->st_send_time,
245                                                       nst->st_sock_time));
246         sc->sc_send_count++;
247 }
248 
249 static void o2net_update_recv_stats(struct o2net_sock_container *sc)
250 {
251         sc->sc_tv_process_total = ktime_add(sc->sc_tv_process_total,
252                                             o2net_get_func_run_time(sc));
253         sc->sc_recv_count++;
254 }
255 
256 #else
257 
258 # define o2net_update_send_stats(a, b)
259 
260 # define o2net_update_recv_stats(sc)
261 
262 #endif /* CONFIG_OCFS2_FS_STATS */
263 
264 static inline int o2net_reconnect_delay(void)
265 {
266         return o2nm_single_cluster->cl_reconnect_delay_ms;
267 }
268 
269 static inline int o2net_keepalive_delay(void)
270 {
271         return o2nm_single_cluster->cl_keepalive_delay_ms;
272 }
273 
274 static inline int o2net_idle_timeout(void)
275 {
276         return o2nm_single_cluster->cl_idle_timeout_ms;
277 }
278 
279 static inline int o2net_sys_err_to_errno(enum o2net_system_error err)
280 {
281         int trans;
282         BUG_ON(err >= O2NET_ERR_MAX);
283         trans = o2net_sys_err_translations[err];
284 
285         /* Just in case we mess up the translation table above */
286         BUG_ON(err != O2NET_ERR_NONE && trans == 0);
287         return trans;
288 }
289 
290 static struct o2net_node * o2net_nn_from_num(u8 node_num)
291 {
292         BUG_ON(node_num >= ARRAY_SIZE(o2net_nodes));
293         return &o2net_nodes[node_num];
294 }
295 
296 static u8 o2net_num_from_nn(struct o2net_node *nn)
297 {
298         BUG_ON(nn == NULL);
299         return nn - o2net_nodes;
300 }
301 
302 /* ------------------------------------------------------------ */
303 
304 static int o2net_prep_nsw(struct o2net_node *nn, struct o2net_status_wait *nsw)
305 {
306         int ret = 0;
307 
308         do {
309                 if (!idr_pre_get(&nn->nn_status_idr, GFP_ATOMIC)) {
310                         ret = -EAGAIN;
311                         break;
312                 }
313                 spin_lock(&nn->nn_lock);
314                 ret = idr_get_new(&nn->nn_status_idr, nsw, &nsw->ns_id);
315                 if (ret == 0)
316                         list_add_tail(&nsw->ns_node_item,
317                                       &nn->nn_status_list);
318                 spin_unlock(&nn->nn_lock);
319         } while (ret == -EAGAIN);
320 
321         if (ret == 0)  {
322                 init_waitqueue_head(&nsw->ns_wq);
323                 nsw->ns_sys_status = O2NET_ERR_NONE;
324                 nsw->ns_status = 0;
325         }
326 
327         return ret;
328 }
329 
330 static void o2net_complete_nsw_locked(struct o2net_node *nn,
331                                       struct o2net_status_wait *nsw,
332                                       enum o2net_system_error sys_status,
333                                       s32 status)
334 {
335         assert_spin_locked(&nn->nn_lock);
336 
337         if (!list_empty(&nsw->ns_node_item)) {
338                 list_del_init(&nsw->ns_node_item);
339                 nsw->ns_sys_status = sys_status;
340                 nsw->ns_status = status;
341                 idr_remove(&nn->nn_status_idr, nsw->ns_id);
342                 wake_up(&nsw->ns_wq);
343         }
344 }
345 
346 static void o2net_complete_nsw(struct o2net_node *nn,
347                                struct o2net_status_wait *nsw,
348                                u64 id, enum o2net_system_error sys_status,
349                                s32 status)
350 {
351         spin_lock(&nn->nn_lock);
352         if (nsw == NULL) {
353                 if (id > INT_MAX)
354                         goto out;
355 
356                 nsw = idr_find(&nn->nn_status_idr, id);
357                 if (nsw == NULL)
358                         goto out;
359         }
360 
361         o2net_complete_nsw_locked(nn, nsw, sys_status, status);
362 
363 out:
364         spin_unlock(&nn->nn_lock);
365         return;
366 }
367 
368 static void o2net_complete_nodes_nsw(struct o2net_node *nn)
369 {
370         struct o2net_status_wait *nsw, *tmp;
371         unsigned int num_kills = 0;
372 
373         assert_spin_locked(&nn->nn_lock);
374 
375         list_for_each_entry_safe(nsw, tmp, &nn->nn_status_list, ns_node_item) {
376                 o2net_complete_nsw_locked(nn, nsw, O2NET_ERR_DIED, 0);
377                 num_kills++;
378         }
379 
380         mlog(0, "completed %d messages for node %u\n", num_kills,
381              o2net_num_from_nn(nn));
382 }
383 
384 static int o2net_nsw_completed(struct o2net_node *nn,
385                                struct o2net_status_wait *nsw)
386 {
387         int completed;
388         spin_lock(&nn->nn_lock);
389         completed = list_empty(&nsw->ns_node_item);
390         spin_unlock(&nn->nn_lock);
391         return completed;
392 }
393 
394 /* ------------------------------------------------------------ */
395 
396 static void sc_kref_release(struct kref *kref)
397 {
398         struct o2net_sock_container *sc = container_of(kref,
399                                         struct o2net_sock_container, sc_kref);
400         BUG_ON(timer_pending(&sc->sc_idle_timeout));
401 
402         sclog(sc, "releasing\n");
403 
404         if (sc->sc_sock) {
405                 sock_release(sc->sc_sock);
406                 sc->sc_sock = NULL;
407         }
408 
409         o2nm_undepend_item(&sc->sc_node->nd_item);
410         o2nm_node_put(sc->sc_node);
411         sc->sc_node = NULL;
412 
413         o2net_debug_del_sc(sc);
414         kfree(sc);
415 }
416 
417 static void sc_put(struct o2net_sock_container *sc)
418 {
419         sclog(sc, "put\n");
420         kref_put(&sc->sc_kref, sc_kref_release);
421 }
422 static void sc_get(struct o2net_sock_container *sc)
423 {
424         sclog(sc, "get\n");
425         kref_get(&sc->sc_kref);
426 }
427 static struct o2net_sock_container *sc_alloc(struct o2nm_node *node)
428 {
429         struct o2net_sock_container *sc, *ret = NULL;
430         struct page *page = NULL;
431         int status = 0;
432 
433         page = alloc_page(GFP_NOFS);
434         sc = kzalloc(sizeof(*sc), GFP_NOFS);
435         if (sc == NULL || page == NULL)
436                 goto out;
437 
438         kref_init(&sc->sc_kref);
439         o2nm_node_get(node);
440         sc->sc_node = node;
441 
442         /* pin the node item of the remote node */
443         status = o2nm_depend_item(&node->nd_item);
444         if (status) {
445                 mlog_errno(status);
446                 o2nm_node_put(node);
447                 goto out;
448         }
449         INIT_WORK(&sc->sc_connect_work, o2net_sc_connect_completed);
450         INIT_WORK(&sc->sc_rx_work, o2net_rx_until_empty);
451         INIT_WORK(&sc->sc_shutdown_work, o2net_shutdown_sc);
452         INIT_DELAYED_WORK(&sc->sc_keepalive_work, o2net_sc_send_keep_req);
453 
454         init_timer(&sc->sc_idle_timeout);
455         sc->sc_idle_timeout.function = o2net_idle_timer;
456         sc->sc_idle_timeout.data = (unsigned long)sc;
457 
458         sclog(sc, "alloced\n");
459 
460         ret = sc;
461         sc->sc_page = page;
462         o2net_debug_add_sc(sc);
463         sc = NULL;
464         page = NULL;
465 
466 out:
467         if (page)
468                 __free_page(page);
469         kfree(sc);
470 
471         return ret;
472 }
473 
474 /* ------------------------------------------------------------ */
475 
476 static void o2net_sc_queue_work(struct o2net_sock_container *sc,
477                                 struct work_struct *work)
478 {
479         sc_get(sc);
480         if (!queue_work(o2net_wq, work))
481                 sc_put(sc);
482 }
483 static void o2net_sc_queue_delayed_work(struct o2net_sock_container *sc,
484                                         struct delayed_work *work,
485                                         int delay)
486 {
487         sc_get(sc);
488         if (!queue_delayed_work(o2net_wq, work, delay))
489                 sc_put(sc);
490 }
491 static void o2net_sc_cancel_delayed_work(struct o2net_sock_container *sc,
492                                          struct delayed_work *work)
493 {
494         if (cancel_delayed_work(work))
495                 sc_put(sc);
496 }
497 
498 static atomic_t o2net_connected_peers = ATOMIC_INIT(0);
499 
500 int o2net_num_connected_peers(void)
501 {
502         return atomic_read(&o2net_connected_peers);
503 }
504 
505 static void o2net_set_nn_state(struct o2net_node *nn,
506                                struct o2net_sock_container *sc,
507                                unsigned valid, int err)
508 {
509         int was_valid = nn->nn_sc_valid;
510         int was_err = nn->nn_persistent_error;
511         struct o2net_sock_container *old_sc = nn->nn_sc;
512 
513         assert_spin_locked(&nn->nn_lock);
514 
515         if (old_sc && !sc)
516                 atomic_dec(&o2net_connected_peers);
517         else if (!old_sc && sc)
518                 atomic_inc(&o2net_connected_peers);
519 
520         /* the node num comparison and single connect/accept path should stop
521          * an non-null sc from being overwritten with another */
522         BUG_ON(sc && nn->nn_sc && nn->nn_sc != sc);
523         mlog_bug_on_msg(err && valid, "err %d valid %u\n", err, valid);
524         mlog_bug_on_msg(valid && !sc, "valid %u sc %p\n", valid, sc);
525 
526         if (was_valid && !valid && err == 0)
527                 err = -ENOTCONN;
528 
529         mlog(ML_CONN, "node %u sc: %p -> %p, valid %u -> %u, err %d -> %d\n",
530              o2net_num_from_nn(nn), nn->nn_sc, sc, nn->nn_sc_valid, valid,
531              nn->nn_persistent_error, err);
532 
533         nn->nn_sc = sc;
534         nn->nn_sc_valid = valid ? 1 : 0;
535         nn->nn_persistent_error = err;
536 
537         /* mirrors o2net_tx_can_proceed() */
538         if (nn->nn_persistent_error || nn->nn_sc_valid)
539                 wake_up(&nn->nn_sc_wq);
540 
541         if (!was_err && nn->nn_persistent_error) {
542                 o2quo_conn_err(o2net_num_from_nn(nn));
543                 queue_delayed_work(o2net_wq, &nn->nn_still_up,
544                                    msecs_to_jiffies(O2NET_QUORUM_DELAY_MS));
545         }
546 
547         if (was_valid && !valid) {
548                 printk(KERN_NOTICE "o2net: no longer connected to "
549                        SC_NODEF_FMT "\n", SC_NODEF_ARGS(old_sc));
550                 o2net_complete_nodes_nsw(nn);
551         }
552 
553         if (!was_valid && valid) {
554                 o2quo_conn_up(o2net_num_from_nn(nn));
555                 cancel_delayed_work(&nn->nn_connect_expired);
556                 printk(KERN_NOTICE "o2net: %s " SC_NODEF_FMT "\n",
557                        o2nm_this_node() > sc->sc_node->nd_num ?
558                                 "connected to" : "accepted connection from",
559                        SC_NODEF_ARGS(sc));
560         }
561 
562         /* trigger the connecting worker func as long as we're not valid,
563          * it will back off if it shouldn't connect.  This can be called
564          * from node config teardown and so needs to be careful about
565          * the work queue actually being up. */
566         if (!valid && o2net_wq) {
567                 unsigned long delay;
568                 /* delay if we're within a RECONNECT_DELAY of the
569                  * last attempt */
570                 delay = (nn->nn_last_connect_attempt +
571                          msecs_to_jiffies(o2net_reconnect_delay()))
572                         - jiffies;
573                 if (delay > msecs_to_jiffies(o2net_reconnect_delay()))
574                         delay = 0;
575                 mlog(ML_CONN, "queueing conn attempt in %lu jiffies\n", delay);
576                 queue_delayed_work(o2net_wq, &nn->nn_connect_work, delay);
577 
578                 /*
579                  * Delay the expired work after idle timeout.
580                  *
581                  * We might have lots of failed connection attempts that run
582                  * through here but we only cancel the connect_expired work when
583                  * a connection attempt succeeds.  So only the first enqueue of
584                  * the connect_expired work will do anything.  The rest will see
585                  * that it's already queued and do nothing.
586                  */
587                 delay += msecs_to_jiffies(o2net_idle_timeout());
588                 queue_delayed_work(o2net_wq, &nn->nn_connect_expired, delay);
589         }
590 
591         /* keep track of the nn's sc ref for the caller */
592         if ((old_sc == NULL) && sc)
593                 sc_get(sc);
594         if (old_sc && (old_sc != sc)) {
595                 o2net_sc_queue_work(old_sc, &old_sc->sc_shutdown_work);
596                 sc_put(old_sc);
597         }
598 }
599 
600 /* see o2net_register_callbacks() */
601 static void o2net_data_ready(struct sock *sk, int bytes)
602 {
603         void (*ready)(struct sock *sk, int bytes);
604 
605         read_lock(&sk->sk_callback_lock);
606         if (sk->sk_user_data) {
607                 struct o2net_sock_container *sc = sk->sk_user_data;
608                 sclog(sc, "data_ready hit\n");
609                 o2net_set_data_ready_time(sc);
610                 o2net_sc_queue_work(sc, &sc->sc_rx_work);
611                 ready = sc->sc_data_ready;
612         } else {
613                 ready = sk->sk_data_ready;
614         }
615         read_unlock(&sk->sk_callback_lock);
616 
617         ready(sk, bytes);
618 }
619 
620 /* see o2net_register_callbacks() */
621 static void o2net_state_change(struct sock *sk)
622 {
623         void (*state_change)(struct sock *sk);
624         struct o2net_sock_container *sc;
625 
626         read_lock(&sk->sk_callback_lock);
627         sc = sk->sk_user_data;
628         if (sc == NULL) {
629                 state_change = sk->sk_state_change;
630                 goto out;
631         }
632 
633         sclog(sc, "state_change to %d\n", sk->sk_state);
634 
635         state_change = sc->sc_state_change;
636 
637         switch(sk->sk_state) {
638                 /* ignore connecting sockets as they make progress */
639                 case TCP_SYN_SENT:
640                 case TCP_SYN_RECV:
641                         break;
642                 case TCP_ESTABLISHED:
643                         o2net_sc_queue_work(sc, &sc->sc_connect_work);
644                         break;
645                 default:
646                         printk(KERN_INFO "o2net: connection to " SC_NODEF_FMT
647                               " shutdown, state %d\n",
648                               SC_NODEF_ARGS(sc), sk->sk_state);
649                         o2net_sc_queue_work(sc, &sc->sc_shutdown_work);
650                         break;
651         }
652 out:
653         read_unlock(&sk->sk_callback_lock);
654         state_change(sk);
655 }
656 
657 /*
658  * we register callbacks so we can queue work on events before calling
659  * the original callbacks.  our callbacks our careful to test user_data
660  * to discover when they've reaced with o2net_unregister_callbacks().
661  */
662 static void o2net_register_callbacks(struct sock *sk,
663                                      struct o2net_sock_container *sc)
664 {
665         write_lock_bh(&sk->sk_callback_lock);
666 
667         /* accepted sockets inherit the old listen socket data ready */
668         if (sk->sk_data_ready == o2net_listen_data_ready) {
669                 sk->sk_data_ready = sk->sk_user_data;
670                 sk->sk_user_data = NULL;
671         }
672 
673         BUG_ON(sk->sk_user_data != NULL);
674         sk->sk_user_data = sc;
675         sc_get(sc);
676 
677         sc->sc_data_ready = sk->sk_data_ready;
678         sc->sc_state_change = sk->sk_state_change;
679         sk->sk_data_ready = o2net_data_ready;
680         sk->sk_state_change = o2net_state_change;
681 
682         mutex_init(&sc->sc_send_lock);
683 
684         write_unlock_bh(&sk->sk_callback_lock);
685 }
686 
687 static int o2net_unregister_callbacks(struct sock *sk,
688                                    struct o2net_sock_container *sc)
689 {
690         int ret = 0;
691 
692         write_lock_bh(&sk->sk_callback_lock);
693         if (sk->sk_user_data == sc) {
694                 ret = 1;
695                 sk->sk_user_data = NULL;
696                 sk->sk_data_ready = sc->sc_data_ready;
697                 sk->sk_state_change = sc->sc_state_change;
698         }
699         write_unlock_bh(&sk->sk_callback_lock);
700 
701         return ret;
702 }
703 
704 /*
705  * this is a little helper that is called by callers who have seen a problem
706  * with an sc and want to detach it from the nn if someone already hasn't beat
707  * them to it.  if an error is given then the shutdown will be persistent
708  * and pending transmits will be canceled.
709  */
710 static void o2net_ensure_shutdown(struct o2net_node *nn,
711                                    struct o2net_sock_container *sc,
712                                    int err)
713 {
714         spin_lock(&nn->nn_lock);
715         if (nn->nn_sc == sc)
716                 o2net_set_nn_state(nn, NULL, 0, err);
717         spin_unlock(&nn->nn_lock);
718 }
719 
720 /*
721  * This work queue function performs the blocking parts of socket shutdown.  A
722  * few paths lead here.  set_nn_state will trigger this callback if it sees an
723  * sc detached from the nn.  state_change will also trigger this callback
724  * directly when it sees errors.  In that case we need to call set_nn_state
725  * ourselves as state_change couldn't get the nn_lock and call set_nn_state
726  * itself.
727  */
728 static void o2net_shutdown_sc(struct work_struct *work)
729 {
730         struct o2net_sock_container *sc =
731                 container_of(work, struct o2net_sock_container,
732                              sc_shutdown_work);
733         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
734 
735         sclog(sc, "shutting down\n");
736 
737         /* drop the callbacks ref and call shutdown only once */
738         if (o2net_unregister_callbacks(sc->sc_sock->sk, sc)) {
739                 /* we shouldn't flush as we're in the thread, the
740                  * races with pending sc work structs are harmless */
741                 del_timer_sync(&sc->sc_idle_timeout);
742                 o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
743                 sc_put(sc);
744                 kernel_sock_shutdown(sc->sc_sock, SHUT_RDWR);
745         }
746 
747         /* not fatal so failed connects before the other guy has our
748          * heartbeat can be retried */
749         o2net_ensure_shutdown(nn, sc, 0);
750         sc_put(sc);
751 }
752 
753 /* ------------------------------------------------------------ */
754 
755 static int o2net_handler_cmp(struct o2net_msg_handler *nmh, u32 msg_type,
756                              u32 key)
757 {
758         int ret = memcmp(&nmh->nh_key, &key, sizeof(key));
759 
760         if (ret == 0)
761                 ret = memcmp(&nmh->nh_msg_type, &msg_type, sizeof(msg_type));
762 
763         return ret;
764 }
765 
766 static struct o2net_msg_handler *
767 o2net_handler_tree_lookup(u32 msg_type, u32 key, struct rb_node ***ret_p,
768                           struct rb_node **ret_parent)
769 {
770         struct rb_node **p = &o2net_handler_tree.rb_node;
771         struct rb_node *parent = NULL;
772         struct o2net_msg_handler *nmh, *ret = NULL;
773         int cmp;
774 
775         while (*p) {
776                 parent = *p;
777                 nmh = rb_entry(parent, struct o2net_msg_handler, nh_node);
778                 cmp = o2net_handler_cmp(nmh, msg_type, key);
779 
780                 if (cmp < 0)
781                         p = &(*p)->rb_left;
782                 else if (cmp > 0)
783                         p = &(*p)->rb_right;
784                 else {
785                         ret = nmh;
786                         break;
787                 }
788         }
789 
790         if (ret_p != NULL)
791                 *ret_p = p;
792         if (ret_parent != NULL)
793                 *ret_parent = parent;
794 
795         return ret;
796 }
797 
798 static void o2net_handler_kref_release(struct kref *kref)
799 {
800         struct o2net_msg_handler *nmh;
801         nmh = container_of(kref, struct o2net_msg_handler, nh_kref);
802 
803         kfree(nmh);
804 }
805 
806 static void o2net_handler_put(struct o2net_msg_handler *nmh)
807 {
808         kref_put(&nmh->nh_kref, o2net_handler_kref_release);
809 }
810 
811 /* max_len is protection for the handler func.  incoming messages won't
812  * be given to the handler if their payload is longer than the max. */
813 int o2net_register_handler(u32 msg_type, u32 key, u32 max_len,
814                            o2net_msg_handler_func *func, void *data,
815                            o2net_post_msg_handler_func *post_func,
816                            struct list_head *unreg_list)
817 {
818         struct o2net_msg_handler *nmh = NULL;
819         struct rb_node **p, *parent;
820         int ret = 0;
821 
822         if (max_len > O2NET_MAX_PAYLOAD_BYTES) {
823                 mlog(0, "max_len for message handler out of range: %u\n",
824                         max_len);
825                 ret = -EINVAL;
826                 goto out;
827         }
828 
829         if (!msg_type) {
830                 mlog(0, "no message type provided: %u, %p\n", msg_type, func);
831                 ret = -EINVAL;
832                 goto out;
833 
834         }
835         if (!func) {
836                 mlog(0, "no message handler provided: %u, %p\n",
837                        msg_type, func);
838                 ret = -EINVAL;
839                 goto out;
840         }
841 
842         nmh = kzalloc(sizeof(struct o2net_msg_handler), GFP_NOFS);
843         if (nmh == NULL) {
844                 ret = -ENOMEM;
845                 goto out;
846         }
847 
848         nmh->nh_func = func;
849         nmh->nh_func_data = data;
850         nmh->nh_post_func = post_func;
851         nmh->nh_msg_type = msg_type;
852         nmh->nh_max_len = max_len;
853         nmh->nh_key = key;
854         /* the tree and list get this ref.. they're both removed in
855          * unregister when this ref is dropped */
856         kref_init(&nmh->nh_kref);
857         INIT_LIST_HEAD(&nmh->nh_unregister_item);
858 
859         write_lock(&o2net_handler_lock);
860         if (o2net_handler_tree_lookup(msg_type, key, &p, &parent))
861                 ret = -EEXIST;
862         else {
863                 rb_link_node(&nmh->nh_node, parent, p);
864                 rb_insert_color(&nmh->nh_node, &o2net_handler_tree);
865                 list_add_tail(&nmh->nh_unregister_item, unreg_list);
866 
867                 mlog(ML_TCP, "registered handler func %p type %u key %08x\n",
868                      func, msg_type, key);
869                 /* we've had some trouble with handlers seemingly vanishing. */
870                 mlog_bug_on_msg(o2net_handler_tree_lookup(msg_type, key, &p,
871                                                           &parent) == NULL,
872                                 "couldn't find handler we *just* registerd "
873                                 "for type %u key %08x\n", msg_type, key);
874         }
875         write_unlock(&o2net_handler_lock);
876         if (ret)
877                 goto out;
878 
879 out:
880         if (ret)
881                 kfree(nmh);
882 
883         return ret;
884 }
885 EXPORT_SYMBOL_GPL(o2net_register_handler);
886 
887 void o2net_unregister_handler_list(struct list_head *list)
888 {
889         struct o2net_msg_handler *nmh, *n;
890 
891         write_lock(&o2net_handler_lock);
892         list_for_each_entry_safe(nmh, n, list, nh_unregister_item) {
893                 mlog(ML_TCP, "unregistering handler func %p type %u key %08x\n",
894                      nmh->nh_func, nmh->nh_msg_type, nmh->nh_key);
895                 rb_erase(&nmh->nh_node, &o2net_handler_tree);
896                 list_del_init(&nmh->nh_unregister_item);
897                 kref_put(&nmh->nh_kref, o2net_handler_kref_release);
898         }
899         write_unlock(&o2net_handler_lock);
900 }
901 EXPORT_SYMBOL_GPL(o2net_unregister_handler_list);
902 
903 static struct o2net_msg_handler *o2net_handler_get(u32 msg_type, u32 key)
904 {
905         struct o2net_msg_handler *nmh;
906 
907         read_lock(&o2net_handler_lock);
908         nmh = o2net_handler_tree_lookup(msg_type, key, NULL, NULL);
909         if (nmh)
910                 kref_get(&nmh->nh_kref);
911         read_unlock(&o2net_handler_lock);
912 
913         return nmh;
914 }
915 
916 /* ------------------------------------------------------------ */
917 
918 static int o2net_recv_tcp_msg(struct socket *sock, void *data, size_t len)
919 {
920         int ret;
921         mm_segment_t oldfs;
922         struct kvec vec = {
923                 .iov_len = len,
924                 .iov_base = data,
925         };
926         struct msghdr msg = {
927                 .msg_iovlen = 1,
928                 .msg_iov = (struct iovec *)&vec,
929                 .msg_flags = MSG_DONTWAIT,
930         };
931 
932         oldfs = get_fs();
933         set_fs(get_ds());
934         ret = sock_recvmsg(sock, &msg, len, msg.msg_flags);
935         set_fs(oldfs);
936 
937         return ret;
938 }
939 
940 static int o2net_send_tcp_msg(struct socket *sock, struct kvec *vec,
941                               size_t veclen, size_t total)
942 {
943         int ret;
944         mm_segment_t oldfs;
945         struct msghdr msg = {
946                 .msg_iov = (struct iovec *)vec,
947                 .msg_iovlen = veclen,
948         };
949 
950         if (sock == NULL) {
951                 ret = -EINVAL;
952                 goto out;
953         }
954 
955         oldfs = get_fs();
956         set_fs(get_ds());
957         ret = sock_sendmsg(sock, &msg, total);
958         set_fs(oldfs);
959         if (ret != total) {
960                 mlog(ML_ERROR, "sendmsg returned %d instead of %zu\n", ret,
961                      total);
962                 if (ret >= 0)
963                         ret = -EPIPE; /* should be smarter, I bet */
964                 goto out;
965         }
966 
967         ret = 0;
968 out:
969         if (ret < 0)
970                 mlog(0, "returning error: %d\n", ret);
971         return ret;
972 }
973 
974 static void o2net_sendpage(struct o2net_sock_container *sc,
975                            void *kmalloced_virt,
976                            size_t size)
977 {
978         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
979         ssize_t ret;
980 
981         while (1) {
982                 mutex_lock(&sc->sc_send_lock);
983                 ret = sc->sc_sock->ops->sendpage(sc->sc_sock,
984                                                  virt_to_page(kmalloced_virt),
985                                                  (long)kmalloced_virt & ~PAGE_MASK,
986                                                  size, MSG_DONTWAIT);
987                 mutex_unlock(&sc->sc_send_lock);
988                 if (ret == size)
989                         break;
990                 if (ret == (ssize_t)-EAGAIN) {
991                         mlog(0, "sendpage of size %zu to " SC_NODEF_FMT
992                              " returned EAGAIN\n", size, SC_NODEF_ARGS(sc));
993                         cond_resched();
994                         continue;
995                 }
996                 mlog(ML_ERROR, "sendpage of size %zu to " SC_NODEF_FMT
997                      " failed with %zd\n", size, SC_NODEF_ARGS(sc), ret);
998                 o2net_ensure_shutdown(nn, sc, 0);
999                 break;
1000         }
1001 }
1002 
1003 static void o2net_init_msg(struct o2net_msg *msg, u16 data_len, u16 msg_type, u32 key)
1004 {
1005         memset(msg, 0, sizeof(struct o2net_msg));
1006         msg->magic = cpu_to_be16(O2NET_MSG_MAGIC);
1007         msg->data_len = cpu_to_be16(data_len);
1008         msg->msg_type = cpu_to_be16(msg_type);
1009         msg->sys_status = cpu_to_be32(O2NET_ERR_NONE);
1010         msg->status = 0;
1011         msg->key = cpu_to_be32(key);
1012 }
1013 
1014 static int o2net_tx_can_proceed(struct o2net_node *nn,
1015                                 struct o2net_sock_container **sc_ret,
1016                                 int *error)
1017 {
1018         int ret = 0;
1019 
1020         spin_lock(&nn->nn_lock);
1021         if (nn->nn_persistent_error) {
1022                 ret = 1;
1023                 *sc_ret = NULL;
1024                 *error = nn->nn_persistent_error;
1025         } else if (nn->nn_sc_valid) {
1026                 kref_get(&nn->nn_sc->sc_kref);
1027 
1028                 ret = 1;
1029                 *sc_ret = nn->nn_sc;
1030                 *error = 0;
1031         }
1032         spin_unlock(&nn->nn_lock);
1033 
1034         return ret;
1035 }
1036 
1037 int o2net_send_message_vec(u32 msg_type, u32 key, struct kvec *caller_vec,
1038                            size_t caller_veclen, u8 target_node, int *status)
1039 {
1040         int ret = 0;
1041         struct o2net_msg *msg = NULL;
1042         size_t veclen, caller_bytes = 0;
1043         struct kvec *vec = NULL;
1044         struct o2net_sock_container *sc = NULL;
1045         struct o2net_node *nn = o2net_nn_from_num(target_node);
1046         struct o2net_status_wait nsw = {
1047                 .ns_node_item = LIST_HEAD_INIT(nsw.ns_node_item),
1048         };
1049         struct o2net_send_tracking nst;
1050 
1051         o2net_init_nst(&nst, msg_type, key, current, target_node);
1052 
1053         if (o2net_wq == NULL) {
1054                 mlog(0, "attempt to tx without o2netd running\n");
1055                 ret = -ESRCH;
1056                 goto out;
1057         }
1058 
1059         if (caller_veclen == 0) {
1060                 mlog(0, "bad kvec array length\n");
1061                 ret = -EINVAL;
1062                 goto out;
1063         }
1064 
1065         caller_bytes = iov_length((struct iovec *)caller_vec, caller_veclen);
1066         if (caller_bytes > O2NET_MAX_PAYLOAD_BYTES) {
1067                 mlog(0, "total payload len %zu too large\n", caller_bytes);
1068                 ret = -EINVAL;
1069                 goto out;
1070         }
1071 
1072         if (target_node == o2nm_this_node()) {
1073                 ret = -ELOOP;
1074                 goto out;
1075         }
1076 
1077         o2net_debug_add_nst(&nst);
1078 
1079         o2net_set_nst_sock_time(&nst);
1080 
1081         wait_event(nn->nn_sc_wq, o2net_tx_can_proceed(nn, &sc, &ret));
1082         if (ret)
1083                 goto out;
1084 
1085         o2net_set_nst_sock_container(&nst, sc);
1086 
1087         veclen = caller_veclen + 1;
1088         vec = kmalloc(sizeof(struct kvec) * veclen, GFP_ATOMIC);
1089         if (vec == NULL) {
1090                 mlog(0, "failed to %zu element kvec!\n", veclen);
1091                 ret = -ENOMEM;
1092                 goto out;
1093         }
1094 
1095         msg = kmalloc(sizeof(struct o2net_msg), GFP_ATOMIC);
1096         if (!msg) {
1097                 mlog(0, "failed to allocate a o2net_msg!\n");
1098                 ret = -ENOMEM;
1099                 goto out;
1100         }
1101 
1102         o2net_init_msg(msg, caller_bytes, msg_type, key);
1103 
1104         vec[0].iov_len = sizeof(struct o2net_msg);
1105         vec[0].iov_base = msg;
1106         memcpy(&vec[1], caller_vec, caller_veclen * sizeof(struct kvec));
1107 
1108         ret = o2net_prep_nsw(nn, &nsw);
1109         if (ret)
1110                 goto out;
1111 
1112         msg->msg_num = cpu_to_be32(nsw.ns_id);
1113         o2net_set_nst_msg_id(&nst, nsw.ns_id);
1114 
1115         o2net_set_nst_send_time(&nst);
1116 
1117         /* finally, convert the message header to network byte-order
1118          * and send */
1119         mutex_lock(&sc->sc_send_lock);
1120         ret = o2net_send_tcp_msg(sc->sc_sock, vec, veclen,
1121                                  sizeof(struct o2net_msg) + caller_bytes);
1122         mutex_unlock(&sc->sc_send_lock);
1123         msglog(msg, "sending returned %d\n", ret);
1124         if (ret < 0) {
1125                 mlog(0, "error returned from o2net_send_tcp_msg=%d\n", ret);
1126                 goto out;
1127         }
1128 
1129         /* wait on other node's handler */
1130         o2net_set_nst_status_time(&nst);
1131         wait_event(nsw.ns_wq, o2net_nsw_completed(nn, &nsw));
1132 
1133         o2net_update_send_stats(&nst, sc);
1134 
1135         /* Note that we avoid overwriting the callers status return
1136          * variable if a system error was reported on the other
1137          * side. Callers beware. */
1138         ret = o2net_sys_err_to_errno(nsw.ns_sys_status);
1139         if (status && !ret)
1140                 *status = nsw.ns_status;
1141 
1142         mlog(0, "woken, returning system status %d, user status %d\n",
1143              ret, nsw.ns_status);
1144 out:
1145         o2net_debug_del_nst(&nst); /* must be before dropping sc and node */
1146         if (sc)
1147                 sc_put(sc);
1148         if (vec)
1149                 kfree(vec);
1150         if (msg)
1151                 kfree(msg);
1152         o2net_complete_nsw(nn, &nsw, 0, 0, 0);
1153         return ret;
1154 }
1155 EXPORT_SYMBOL_GPL(o2net_send_message_vec);
1156 
1157 int o2net_send_message(u32 msg_type, u32 key, void *data, u32 len,
1158                        u8 target_node, int *status)
1159 {
1160         struct kvec vec = {
1161                 .iov_base = data,
1162                 .iov_len = len,
1163         };
1164         return o2net_send_message_vec(msg_type, key, &vec, 1,
1165                                       target_node, status);
1166 }
1167 EXPORT_SYMBOL_GPL(o2net_send_message);
1168 
1169 static int o2net_send_status_magic(struct socket *sock, struct o2net_msg *hdr,
1170                                    enum o2net_system_error syserr, int err)
1171 {
1172         struct kvec vec = {
1173                 .iov_base = hdr,
1174                 .iov_len = sizeof(struct o2net_msg),
1175         };
1176 
1177         BUG_ON(syserr >= O2NET_ERR_MAX);
1178 
1179         /* leave other fields intact from the incoming message, msg_num
1180          * in particular */
1181         hdr->sys_status = cpu_to_be32(syserr);
1182         hdr->status = cpu_to_be32(err);
1183         hdr->magic = cpu_to_be16(O2NET_MSG_STATUS_MAGIC);  // twiddle the magic
1184         hdr->data_len = 0;
1185 
1186         msglog(hdr, "about to send status magic %d\n", err);
1187         /* hdr has been in host byteorder this whole time */
1188         return o2net_send_tcp_msg(sock, &vec, 1, sizeof(struct o2net_msg));
1189 }
1190 
1191 /* this returns -errno if the header was unknown or too large, etc.
1192  * after this is called the buffer us reused for the next message */
1193 static int o2net_process_message(struct o2net_sock_container *sc,
1194                                  struct o2net_msg *hdr)
1195 {
1196         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1197         int ret = 0, handler_status;
1198         enum  o2net_system_error syserr;
1199         struct o2net_msg_handler *nmh = NULL;
1200         void *ret_data = NULL;
1201 
1202         msglog(hdr, "processing message\n");
1203 
1204         o2net_sc_postpone_idle(sc);
1205 
1206         switch(be16_to_cpu(hdr->magic)) {
1207                 case O2NET_MSG_STATUS_MAGIC:
1208                         /* special type for returning message status */
1209                         o2net_complete_nsw(nn, NULL,
1210                                            be32_to_cpu(hdr->msg_num),
1211                                            be32_to_cpu(hdr->sys_status),
1212                                            be32_to_cpu(hdr->status));
1213                         goto out;
1214                 case O2NET_MSG_KEEP_REQ_MAGIC:
1215                         o2net_sendpage(sc, o2net_keep_resp,
1216                                        sizeof(*o2net_keep_resp));
1217                         goto out;
1218                 case O2NET_MSG_KEEP_RESP_MAGIC:
1219                         goto out;
1220                 case O2NET_MSG_MAGIC:
1221                         break;
1222                 default:
1223                         msglog(hdr, "bad magic\n");
1224                         ret = -EINVAL;
1225                         goto out;
1226                         break;
1227         }
1228 
1229         /* find a handler for it */
1230         handler_status = 0;
1231         nmh = o2net_handler_get(be16_to_cpu(hdr->msg_type),
1232                                 be32_to_cpu(hdr->key));
1233         if (!nmh) {
1234                 mlog(ML_TCP, "couldn't find handler for type %u key %08x\n",
1235                      be16_to_cpu(hdr->msg_type), be32_to_cpu(hdr->key));
1236                 syserr = O2NET_ERR_NO_HNDLR;
1237                 goto out_respond;
1238         }
1239 
1240         syserr = O2NET_ERR_NONE;
1241 
1242         if (be16_to_cpu(hdr->data_len) > nmh->nh_max_len)
1243                 syserr = O2NET_ERR_OVERFLOW;
1244 
1245         if (syserr != O2NET_ERR_NONE)
1246                 goto out_respond;
1247 
1248         o2net_set_func_start_time(sc);
1249         sc->sc_msg_key = be32_to_cpu(hdr->key);
1250         sc->sc_msg_type = be16_to_cpu(hdr->msg_type);
1251         handler_status = (nmh->nh_func)(hdr, sizeof(struct o2net_msg) +
1252                                              be16_to_cpu(hdr->data_len),
1253                                         nmh->nh_func_data, &ret_data);
1254         o2net_set_func_stop_time(sc);
1255 
1256         o2net_update_recv_stats(sc);
1257 
1258 out_respond:
1259         /* this destroys the hdr, so don't use it after this */
1260         mutex_lock(&sc->sc_send_lock);
1261         ret = o2net_send_status_magic(sc->sc_sock, hdr, syserr,
1262                                       handler_status);
1263         mutex_unlock(&sc->sc_send_lock);
1264         hdr = NULL;
1265         mlog(0, "sending handler status %d, syserr %d returned %d\n",
1266              handler_status, syserr, ret);
1267 
1268         if (nmh) {
1269                 BUG_ON(ret_data != NULL && nmh->nh_post_func == NULL);
1270                 if (nmh->nh_post_func)
1271                         (nmh->nh_post_func)(handler_status, nmh->nh_func_data,
1272                                             ret_data);
1273         }
1274 
1275 out:
1276         if (nmh)
1277                 o2net_handler_put(nmh);
1278         return ret;
1279 }
1280 
1281 static int o2net_check_handshake(struct o2net_sock_container *sc)
1282 {
1283         struct o2net_handshake *hand = page_address(sc->sc_page);
1284         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1285 
1286         if (hand->protocol_version != cpu_to_be64(O2NET_PROTOCOL_VERSION)) {
1287                 mlog(ML_NOTICE, SC_NODEF_FMT " advertised net protocol "
1288                      "version %llu but %llu is required, disconnecting\n",
1289                      SC_NODEF_ARGS(sc),
1290                      (unsigned long long)be64_to_cpu(hand->protocol_version),
1291                      O2NET_PROTOCOL_VERSION);
1292 
1293                 /* don't bother reconnecting if its the wrong version. */
1294                 o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1295                 return -1;
1296         }
1297 
1298         /*
1299          * Ensure timeouts are consistent with other nodes, otherwise
1300          * we can end up with one node thinking that the other must be down,
1301          * but isn't. This can ultimately cause corruption.
1302          */
1303         if (be32_to_cpu(hand->o2net_idle_timeout_ms) !=
1304                                 o2net_idle_timeout()) {
1305                 mlog(ML_NOTICE, SC_NODEF_FMT " uses a network idle timeout of "
1306                      "%u ms, but we use %u ms locally.  disconnecting\n",
1307                      SC_NODEF_ARGS(sc),
1308                      be32_to_cpu(hand->o2net_idle_timeout_ms),
1309                      o2net_idle_timeout());
1310                 o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1311                 return -1;
1312         }
1313 
1314         if (be32_to_cpu(hand->o2net_keepalive_delay_ms) !=
1315                         o2net_keepalive_delay()) {
1316                 mlog(ML_NOTICE, SC_NODEF_FMT " uses a keepalive delay of "
1317                      "%u ms, but we use %u ms locally.  disconnecting\n",
1318                      SC_NODEF_ARGS(sc),
1319                      be32_to_cpu(hand->o2net_keepalive_delay_ms),
1320                      o2net_keepalive_delay());
1321                 o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1322                 return -1;
1323         }
1324 
1325         if (be32_to_cpu(hand->o2hb_heartbeat_timeout_ms) !=
1326                         O2HB_MAX_WRITE_TIMEOUT_MS) {
1327                 mlog(ML_NOTICE, SC_NODEF_FMT " uses a heartbeat timeout of "
1328                      "%u ms, but we use %u ms locally.  disconnecting\n",
1329                      SC_NODEF_ARGS(sc),
1330                      be32_to_cpu(hand->o2hb_heartbeat_timeout_ms),
1331                      O2HB_MAX_WRITE_TIMEOUT_MS);
1332                 o2net_ensure_shutdown(nn, sc, -ENOTCONN);
1333                 return -1;
1334         }
1335 
1336         sc->sc_handshake_ok = 1;
1337 
1338         spin_lock(&nn->nn_lock);
1339         /* set valid and queue the idle timers only if it hasn't been
1340          * shut down already */
1341         if (nn->nn_sc == sc) {
1342                 o2net_sc_reset_idle_timer(sc);
1343                 atomic_set(&nn->nn_timeout, 0);
1344                 o2net_set_nn_state(nn, sc, 1, 0);
1345         }
1346         spin_unlock(&nn->nn_lock);
1347 
1348         /* shift everything up as though it wasn't there */
1349         sc->sc_page_off -= sizeof(struct o2net_handshake);
1350         if (sc->sc_page_off)
1351                 memmove(hand, hand + 1, sc->sc_page_off);
1352 
1353         return 0;
1354 }
1355 
1356 /* this demuxes the queued rx bytes into header or payload bits and calls
1357  * handlers as each full message is read off the socket.  it returns -error,
1358  * == 0 eof, or > 0 for progress made.*/
1359 static int o2net_advance_rx(struct o2net_sock_container *sc)
1360 {
1361         struct o2net_msg *hdr;
1362         int ret = 0;
1363         void *data;
1364         size_t datalen;
1365 
1366         sclog(sc, "receiving\n");
1367         o2net_set_advance_start_time(sc);
1368 
1369         if (unlikely(sc->sc_handshake_ok == 0)) {
1370                 if(sc->sc_page_off < sizeof(struct o2net_handshake)) {
1371                         data = page_address(sc->sc_page) + sc->sc_page_off;
1372                         datalen = sizeof(struct o2net_handshake) - sc->sc_page_off;
1373                         ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1374                         if (ret > 0)
1375                                 sc->sc_page_off += ret;
1376                 }
1377 
1378                 if (sc->sc_page_off == sizeof(struct o2net_handshake)) {
1379                         o2net_check_handshake(sc);
1380                         if (unlikely(sc->sc_handshake_ok == 0))
1381                                 ret = -EPROTO;
1382                 }
1383                 goto out;
1384         }
1385 
1386         /* do we need more header? */
1387         if (sc->sc_page_off < sizeof(struct o2net_msg)) {
1388                 data = page_address(sc->sc_page) + sc->sc_page_off;
1389                 datalen = sizeof(struct o2net_msg) - sc->sc_page_off;
1390                 ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1391                 if (ret > 0) {
1392                         sc->sc_page_off += ret;
1393                         /* only swab incoming here.. we can
1394                          * only get here once as we cross from
1395                          * being under to over */
1396                         if (sc->sc_page_off == sizeof(struct o2net_msg)) {
1397                                 hdr = page_address(sc->sc_page);
1398                                 if (be16_to_cpu(hdr->data_len) >
1399                                     O2NET_MAX_PAYLOAD_BYTES)
1400                                         ret = -EOVERFLOW;
1401                         }
1402                 }
1403                 if (ret <= 0)
1404                         goto out;
1405         }
1406 
1407         if (sc->sc_page_off < sizeof(struct o2net_msg)) {
1408                 /* oof, still don't have a header */
1409                 goto out;
1410         }
1411 
1412         /* this was swabbed above when we first read it */
1413         hdr = page_address(sc->sc_page);
1414 
1415         msglog(hdr, "at page_off %zu\n", sc->sc_page_off);
1416 
1417         /* do we need more payload? */
1418         if (sc->sc_page_off - sizeof(struct o2net_msg) < be16_to_cpu(hdr->data_len)) {
1419                 /* need more payload */
1420                 data = page_address(sc->sc_page) + sc->sc_page_off;
1421                 datalen = (sizeof(struct o2net_msg) + be16_to_cpu(hdr->data_len)) -
1422                           sc->sc_page_off;
1423                 ret = o2net_recv_tcp_msg(sc->sc_sock, data, datalen);
1424                 if (ret > 0)
1425                         sc->sc_page_off += ret;
1426                 if (ret <= 0)
1427                         goto out;
1428         }
1429 
1430         if (sc->sc_page_off - sizeof(struct o2net_msg) == be16_to_cpu(hdr->data_len)) {
1431                 /* we can only get here once, the first time we read
1432                  * the payload.. so set ret to progress if the handler
1433                  * works out. after calling this the message is toast */
1434                 ret = o2net_process_message(sc, hdr);
1435                 if (ret == 0)
1436                         ret = 1;
1437                 sc->sc_page_off = 0;
1438         }
1439 
1440 out:
1441         sclog(sc, "ret = %d\n", ret);
1442         o2net_set_advance_stop_time(sc);
1443         return ret;
1444 }
1445 
1446 /* this work func is triggerd by data ready.  it reads until it can read no
1447  * more.  it interprets 0, eof, as fatal.  if data_ready hits while we're doing
1448  * our work the work struct will be marked and we'll be called again. */
1449 static void o2net_rx_until_empty(struct work_struct *work)
1450 {
1451         struct o2net_sock_container *sc =
1452                 container_of(work, struct o2net_sock_container, sc_rx_work);
1453         int ret;
1454 
1455         do {
1456                 ret = o2net_advance_rx(sc);
1457         } while (ret > 0);
1458 
1459         if (ret <= 0 && ret != -EAGAIN) {
1460                 struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1461                 sclog(sc, "saw error %d, closing\n", ret);
1462                 /* not permanent so read failed handshake can retry */
1463                 o2net_ensure_shutdown(nn, sc, 0);
1464         }
1465 
1466         sc_put(sc);
1467 }
1468 
1469 static int o2net_set_nodelay(struct socket *sock)
1470 {
1471         int ret, val = 1;
1472         mm_segment_t oldfs;
1473 
1474         oldfs = get_fs();
1475         set_fs(KERNEL_DS);
1476 
1477         /*
1478          * Dear unsuspecting programmer,
1479          *
1480          * Don't use sock_setsockopt() for SOL_TCP.  It doesn't check its level
1481          * argument and assumes SOL_SOCKET so, say, your TCP_NODELAY will
1482          * silently turn into SO_DEBUG.
1483          *
1484          * Yours,
1485          * Keeper of hilariously fragile interfaces.
1486          */
1487         ret = sock->ops->setsockopt(sock, SOL_TCP, TCP_NODELAY,
1488                                     (char __user *)&val, sizeof(val));
1489 
1490         set_fs(oldfs);
1491         return ret;
1492 }
1493 
1494 static void o2net_initialize_handshake(void)
1495 {
1496         o2net_hand->o2hb_heartbeat_timeout_ms = cpu_to_be32(
1497                 O2HB_MAX_WRITE_TIMEOUT_MS);
1498         o2net_hand->o2net_idle_timeout_ms = cpu_to_be32(o2net_idle_timeout());
1499         o2net_hand->o2net_keepalive_delay_ms = cpu_to_be32(
1500                 o2net_keepalive_delay());
1501         o2net_hand->o2net_reconnect_delay_ms = cpu_to_be32(
1502                 o2net_reconnect_delay());
1503 }
1504 
1505 /* ------------------------------------------------------------ */
1506 
1507 /* called when a connect completes and after a sock is accepted.  the
1508  * rx path will see the response and mark the sc valid */
1509 static void o2net_sc_connect_completed(struct work_struct *work)
1510 {
1511         struct o2net_sock_container *sc =
1512                 container_of(work, struct o2net_sock_container,
1513                              sc_connect_work);
1514 
1515         mlog(ML_MSG, "sc sending handshake with ver %llu id %llx\n",
1516               (unsigned long long)O2NET_PROTOCOL_VERSION,
1517               (unsigned long long)be64_to_cpu(o2net_hand->connector_id));
1518 
1519         o2net_initialize_handshake();
1520         o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
1521         sc_put(sc);
1522 }
1523 
1524 /* this is called as a work_struct func. */
1525 static void o2net_sc_send_keep_req(struct work_struct *work)
1526 {
1527         struct o2net_sock_container *sc =
1528                 container_of(work, struct o2net_sock_container,
1529                              sc_keepalive_work.work);
1530 
1531         o2net_sendpage(sc, o2net_keep_req, sizeof(*o2net_keep_req));
1532         sc_put(sc);
1533 }
1534 
1535 /* socket shutdown does a del_timer_sync against this as it tears down.
1536  * we can't start this timer until we've got to the point in sc buildup
1537  * where shutdown is going to be involved */
1538 static void o2net_idle_timer(unsigned long data)
1539 {
1540         struct o2net_sock_container *sc = (struct o2net_sock_container *)data;
1541         struct o2net_node *nn = o2net_nn_from_num(sc->sc_node->nd_num);
1542 
1543 #ifdef CONFIG_DEBUG_FS
1544         ktime_t now = ktime_get();
1545 #endif
1546 
1547         printk(KERN_NOTICE "o2net: connection to " SC_NODEF_FMT " has been idle for %u.%u "
1548              "seconds, shutting it down.\n", SC_NODEF_ARGS(sc),
1549                      o2net_idle_timeout() / 1000,
1550                      o2net_idle_timeout() % 1000);
1551 
1552 #ifdef CONFIG_DEBUG_FS
1553         mlog(ML_NOTICE, "Here are some times that might help debug the "
1554              "situation: (Timer: %lld, Now %lld, DataReady %lld, Advance %lld-%lld, "
1555              "Key 0x%08x, Func %u, FuncTime %lld-%lld)\n",
1556              (long long)ktime_to_us(sc->sc_tv_timer), (long long)ktime_to_us(now),
1557              (long long)ktime_to_us(sc->sc_tv_data_ready),
1558              (long long)ktime_to_us(sc->sc_tv_advance_start),
1559              (long long)ktime_to_us(sc->sc_tv_advance_stop),
1560              sc->sc_msg_key, sc->sc_msg_type,
1561              (long long)ktime_to_us(sc->sc_tv_func_start),
1562              (long long)ktime_to_us(sc->sc_tv_func_stop));
1563 #endif
1564 
1565         /*
1566          * Initialize the nn_timeout so that the next connection attempt
1567          * will continue in o2net_start_connect.
1568          */
1569         atomic_set(&nn->nn_timeout, 1);
1570 
1571         o2net_sc_queue_work(sc, &sc->sc_shutdown_work);
1572 }
1573 
1574 static void o2net_sc_reset_idle_timer(struct o2net_sock_container *sc)
1575 {
1576         o2net_sc_cancel_delayed_work(sc, &sc->sc_keepalive_work);
1577         o2net_sc_queue_delayed_work(sc, &sc->sc_keepalive_work,
1578                       msecs_to_jiffies(o2net_keepalive_delay()));
1579         o2net_set_sock_timer(sc);
1580         mod_timer(&sc->sc_idle_timeout,
1581                jiffies + msecs_to_jiffies(o2net_idle_timeout()));
1582 }
1583 
1584 static void o2net_sc_postpone_idle(struct o2net_sock_container *sc)
1585 {
1586         /* Only push out an existing timer */
1587         if (timer_pending(&sc->sc_idle_timeout))
1588                 o2net_sc_reset_idle_timer(sc);
1589 }
1590 
1591 /* this work func is kicked whenever a path sets the nn state which doesn't
1592  * have valid set.  This includes seeing hb come up, losing a connection,
1593  * having a connect attempt fail, etc. This centralizes the logic which decides
1594  * if a connect attempt should be made or if we should give up and all future
1595  * transmit attempts should fail */
1596 static void o2net_start_connect(struct work_struct *work)
1597 {
1598         struct o2net_node *nn =
1599                 container_of(work, struct o2net_node, nn_connect_work.work);
1600         struct o2net_sock_container *sc = NULL;
1601         struct o2nm_node *node = NULL, *mynode = NULL;
1602         struct socket *sock = NULL;
1603         struct sockaddr_in myaddr = {0, }, remoteaddr = {0, };
1604         int ret = 0, stop;
1605         unsigned int timeout;
1606 
1607         /* if we're greater we initiate tx, otherwise we accept */
1608         if (o2nm_this_node() <= o2net_num_from_nn(nn))
1609                 goto out;
1610 
1611         /* watch for racing with tearing a node down */
1612         node = o2nm_get_node_by_num(o2net_num_from_nn(nn));
1613         if (node == NULL) {
1614                 ret = 0;
1615                 goto out;
1616         }
1617 
1618         mynode = o2nm_get_node_by_num(o2nm_this_node());
1619         if (mynode == NULL) {
1620                 ret = 0;
1621                 goto out;
1622         }
1623 
1624         spin_lock(&nn->nn_lock);
1625         /*
1626          * see if we already have one pending or have given up.
1627          * For nn_timeout, it is set when we close the connection
1628          * because of the idle time out. So it means that we have
1629          * at least connected to that node successfully once,
1630          * now try to connect to it again.
1631          */
1632         timeout = atomic_read(&nn->nn_timeout);
1633         stop = (nn->nn_sc ||
1634                 (nn->nn_persistent_error &&
1635                 (nn->nn_persistent_error != -ENOTCONN || timeout == 0)));
1636         spin_unlock(&nn->nn_lock);
1637         if (stop)
1638                 goto out;
1639 
1640         nn->nn_last_connect_attempt = jiffies;
1641 
1642         sc = sc_alloc(node);
1643         if (sc == NULL) {
1644                 mlog(0, "couldn't allocate sc\n");
1645                 ret = -ENOMEM;
1646                 goto out;
1647         }
1648 
1649         ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
1650         if (ret < 0) {
1651                 mlog(0, "can't create socket: %d\n", ret);
1652                 goto out;
1653         }
1654         sc->sc_sock = sock; /* freed by sc_kref_release */
1655 
1656         sock->sk->sk_allocation = GFP_ATOMIC;
1657 
1658         myaddr.sin_family = AF_INET;
1659         myaddr.sin_addr.s_addr = mynode->nd_ipv4_address;
1660         myaddr.sin_port = htons(0); /* any port */
1661 
1662         ret = sock->ops->bind(sock, (struct sockaddr *)&myaddr,
1663                               sizeof(myaddr));
1664         if (ret) {
1665                 mlog(ML_ERROR, "bind failed with %d at address %pI4\n",
1666                      ret, &mynode->nd_ipv4_address);
1667                 goto out;
1668         }
1669 
1670         ret = o2net_set_nodelay(sc->sc_sock);
1671         if (ret) {
1672                 mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret);
1673                 goto out;
1674         }
1675 
1676         o2net_register_callbacks(sc->sc_sock->sk, sc);
1677 
1678         spin_lock(&nn->nn_lock);
1679         /* handshake completion will set nn->nn_sc_valid */
1680         o2net_set_nn_state(nn, sc, 0, 0);
1681         spin_unlock(&nn->nn_lock);
1682 
1683         remoteaddr.sin_family = AF_INET;
1684         remoteaddr.sin_addr.s_addr = node->nd_ipv4_address;
1685         remoteaddr.sin_port = node->nd_ipv4_port;
1686 
1687         ret = sc->sc_sock->ops->connect(sc->sc_sock,
1688                                         (struct sockaddr *)&remoteaddr,
1689                                         sizeof(remoteaddr),
1690                                         O_NONBLOCK);
1691         if (ret == -EINPROGRESS)
1692                 ret = 0;
1693 
1694 out:
1695         if (ret) {
1696                 mlog(ML_NOTICE, "connect attempt to " SC_NODEF_FMT " failed "
1697                      "with errno %d\n", SC_NODEF_ARGS(sc), ret);
1698                 /* 0 err so that another will be queued and attempted
1699                  * from set_nn_state */
1700                 if (sc)
1701                         o2net_ensure_shutdown(nn, sc, 0);
1702         }
1703         if (sc)
1704                 sc_put(sc);
1705         if (node)
1706                 o2nm_node_put(node);
1707         if (mynode)
1708                 o2nm_node_put(mynode);
1709 
1710         return;
1711 }
1712 
1713 static void o2net_connect_expired(struct work_struct *work)
1714 {
1715         struct o2net_node *nn =
1716                 container_of(work, struct o2net_node, nn_connect_expired.work);
1717 
1718         spin_lock(&nn->nn_lock);
1719         if (!nn->nn_sc_valid) {
1720                 mlog(ML_ERROR, "no connection established with node %u after "
1721                      "%u.%u seconds, giving up and returning errors.\n",
1722                      o2net_num_from_nn(nn),
1723                      o2net_idle_timeout() / 1000,
1724                      o2net_idle_timeout() % 1000);
1725 
1726                 o2net_set_nn_state(nn, NULL, 0, -ENOTCONN);
1727         }
1728         spin_unlock(&nn->nn_lock);
1729 }
1730 
1731 static void o2net_still_up(struct work_struct *work)
1732 {
1733         struct o2net_node *nn =
1734                 container_of(work, struct o2net_node, nn_still_up.work);
1735 
1736         o2quo_hb_still_up(o2net_num_from_nn(nn));
1737 }
1738 
1739 /* ------------------------------------------------------------ */
1740 
1741 void o2net_disconnect_node(struct o2nm_node *node)
1742 {
1743         struct o2net_node *nn = o2net_nn_from_num(node->nd_num);
1744 
1745         /* don't reconnect until it's heartbeating again */
1746         spin_lock(&nn->nn_lock);
1747         atomic_set(&nn->nn_timeout, 0);
1748         o2net_set_nn_state(nn, NULL, 0, -ENOTCONN);
1749         spin_unlock(&nn->nn_lock);
1750 
1751         if (o2net_wq) {
1752                 cancel_delayed_work(&nn->nn_connect_expired);
1753                 cancel_delayed_work(&nn->nn_connect_work);
1754                 cancel_delayed_work(&nn->nn_still_up);
1755                 flush_workqueue(o2net_wq);
1756         }
1757 }
1758 
1759 static void o2net_hb_node_down_cb(struct o2nm_node *node, int node_num,
1760                                   void *data)
1761 {
1762         o2quo_hb_down(node_num);
1763 
1764         if (!node)
1765                 return;
1766 
1767         if (node_num != o2nm_this_node())
1768                 o2net_disconnect_node(node);
1769 
1770         BUG_ON(atomic_read(&o2net_connected_peers) < 0);
1771 }
1772 
1773 static void o2net_hb_node_up_cb(struct o2nm_node *node, int node_num,
1774                                 void *data)
1775 {
1776         struct o2net_node *nn = o2net_nn_from_num(node_num);
1777 
1778         o2quo_hb_up(node_num);
1779 
1780         BUG_ON(!node);
1781 
1782         /* ensure an immediate connect attempt */
1783         nn->nn_last_connect_attempt = jiffies -
1784                 (msecs_to_jiffies(o2net_reconnect_delay()) + 1);
1785 
1786         if (node_num != o2nm_this_node()) {
1787                 /* believe it or not, accept and node hearbeating testing
1788                  * can succeed for this node before we got here.. so
1789                  * only use set_nn_state to clear the persistent error
1790                  * if that hasn't already happened */
1791                 spin_lock(&nn->nn_lock);
1792                 atomic_set(&nn->nn_timeout, 0);
1793                 if (nn->nn_persistent_error)
1794                         o2net_set_nn_state(nn, NULL, 0, 0);
1795                 spin_unlock(&nn->nn_lock);
1796         }
1797 }
1798 
1799 void o2net_unregister_hb_callbacks(void)
1800 {
1801         o2hb_unregister_callback(NULL, &o2net_hb_up);
1802         o2hb_unregister_callback(NULL, &o2net_hb_down);
1803 }
1804 
1805 int o2net_register_hb_callbacks(void)
1806 {
1807         int ret;
1808 
1809         o2hb_setup_callback(&o2net_hb_down, O2HB_NODE_DOWN_CB,
1810                             o2net_hb_node_down_cb, NULL, O2NET_HB_PRI);
1811         o2hb_setup_callback(&o2net_hb_up, O2HB_NODE_UP_CB,
1812                             o2net_hb_node_up_cb, NULL, O2NET_HB_PRI);
1813 
1814         ret = o2hb_register_callback(NULL, &o2net_hb_up);
1815         if (ret == 0)
1816                 ret = o2hb_register_callback(NULL, &o2net_hb_down);
1817 
1818         if (ret)
1819                 o2net_unregister_hb_callbacks();
1820 
1821         return ret;
1822 }
1823 
1824 /* ------------------------------------------------------------ */
1825 
1826 static int o2net_accept_one(struct socket *sock)
1827 {
1828         int ret, slen;
1829         struct sockaddr_in sin;
1830         struct socket *new_sock = NULL;
1831         struct o2nm_node *node = NULL;
1832         struct o2nm_node *local_node = NULL;
1833         struct o2net_sock_container *sc = NULL;
1834         struct o2net_node *nn;
1835 
1836         BUG_ON(sock == NULL);
1837         ret = sock_create_lite(sock->sk->sk_family, sock->sk->sk_type,
1838                                sock->sk->sk_protocol, &new_sock);
1839         if (ret)
1840                 goto out;
1841 
1842         new_sock->type = sock->type;
1843         new_sock->ops = sock->ops;
1844         ret = sock->ops->accept(sock, new_sock, O_NONBLOCK);
1845         if (ret < 0)
1846                 goto out;
1847 
1848         new_sock->sk->sk_allocation = GFP_ATOMIC;
1849 
1850         ret = o2net_set_nodelay(new_sock);
1851         if (ret) {
1852                 mlog(ML_ERROR, "setting TCP_NODELAY failed with %d\n", ret);
1853                 goto out;
1854         }
1855 
1856         slen = sizeof(sin);
1857         ret = new_sock->ops->getname(new_sock, (struct sockaddr *) &sin,
1858                                        &slen, 1);
1859         if (ret < 0)
1860                 goto out;
1861 
1862         node = o2nm_get_node_by_ip(sin.sin_addr.s_addr);
1863         if (node == NULL) {
1864                 mlog(ML_NOTICE, "attempt to connect from unknown node at %pI4:%d\n",
1865                      &sin.sin_addr.s_addr, ntohs(sin.sin_port));
1866                 ret = -EINVAL;
1867                 goto out;
1868         }
1869 
1870         if (o2nm_this_node() >= node->nd_num) {
1871                 local_node = o2nm_get_node_by_num(o2nm_this_node());
1872                 mlog(ML_NOTICE, "unexpected connect attempt seen at node '%s' ("
1873                      "%u, %pI4:%d) from node '%s' (%u, %pI4:%d)\n",
1874                      local_node->nd_name, local_node->nd_num,
1875                      &(local_node->nd_ipv4_address),
1876                      ntohs(local_node->nd_ipv4_port),
1877                      node->nd_name, node->nd_num, &sin.sin_addr.s_addr,
1878                      ntohs(sin.sin_port));
1879                 ret = -EINVAL;
1880                 goto out;
1881         }
1882 
1883         /* this happens all the time when the other node sees our heartbeat
1884          * and tries to connect before we see their heartbeat */
1885         if (!o2hb_check_node_heartbeating_from_callback(node->nd_num)) {
1886                 mlog(ML_CONN, "attempt to connect from node '%s' at "
1887                      "%pI4:%d but it isn't heartbeating\n",
1888                      node->nd_name, &sin.sin_addr.s_addr,
1889                      ntohs(sin.sin_port));
1890                 ret = -EINVAL;
1891                 goto out;
1892         }
1893 
1894         nn = o2net_nn_from_num(node->nd_num);
1895 
1896         spin_lock(&nn->nn_lock);
1897         if (nn->nn_sc)
1898                 ret = -EBUSY;
1899         else
1900                 ret = 0;
1901         spin_unlock(&nn->nn_lock);
1902         if (ret) {
1903                 mlog(ML_NOTICE, "attempt to connect from node '%s' at "
1904                      "%pI4:%d but it already has an open connection\n",
1905                      node->nd_name, &sin.sin_addr.s_addr,
1906                      ntohs(sin.sin_port));
1907                 goto out;
1908         }
1909 
1910         sc = sc_alloc(node);
1911         if (sc == NULL) {
1912                 ret = -ENOMEM;
1913                 goto out;
1914         }
1915 
1916         sc->sc_sock = new_sock;
1917         new_sock = NULL;
1918 
1919         spin_lock(&nn->nn_lock);
1920         atomic_set(&nn->nn_timeout, 0);
1921         o2net_set_nn_state(nn, sc, 0, 0);
1922         spin_unlock(&nn->nn_lock);
1923 
1924         o2net_register_callbacks(sc->sc_sock->sk, sc);
1925         o2net_sc_queue_work(sc, &sc->sc_rx_work);
1926 
1927         o2net_initialize_handshake();
1928         o2net_sendpage(sc, o2net_hand, sizeof(*o2net_hand));
1929 
1930 out:
1931         if (new_sock)
1932                 sock_release(new_sock);
1933         if (node)
1934                 o2nm_node_put(node);
1935         if (local_node)
1936                 o2nm_node_put(local_node);
1937         if (sc)
1938                 sc_put(sc);
1939         return ret;
1940 }
1941 
1942 static void o2net_accept_many(struct work_struct *work)
1943 {
1944         struct socket *sock = o2net_listen_sock;
1945         while (o2net_accept_one(sock) == 0)
1946                 cond_resched();
1947 }
1948 
1949 static void o2net_listen_data_ready(struct sock *sk, int bytes)
1950 {
1951         void (*ready)(struct sock *sk, int bytes);
1952 
1953         read_lock(&sk->sk_callback_lock);
1954         ready = sk->sk_user_data;
1955         if (ready == NULL) { /* check for teardown race */
1956                 ready = sk->sk_data_ready;
1957                 goto out;
1958         }
1959 
1960         /* ->sk_data_ready is also called for a newly established child socket
1961          * before it has been accepted and the acceptor has set up their
1962          * data_ready.. we only want to queue listen work for our listening
1963          * socket */
1964         if (sk->sk_state == TCP_LISTEN) {
1965                 mlog(ML_TCP, "bytes: %d\n", bytes);
1966                 queue_work(o2net_wq, &o2net_listen_work);
1967         }
1968 
1969 out:
1970         read_unlock(&sk->sk_callback_lock);
1971         ready(sk, bytes);
1972 }
1973 
1974 static int o2net_open_listening_sock(__be32 addr, __be16 port)
1975 {
1976         struct socket *sock = NULL;
1977         int ret;
1978         struct sockaddr_in sin = {
1979                 .sin_family = PF_INET,
1980                 .sin_addr = { .s_addr = addr },
1981                 .sin_port = port,
1982         };
1983 
1984         ret = sock_create(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
1985         if (ret < 0) {
1986                 mlog(ML_ERROR, "unable to create socket, ret=%d\n", ret);
1987                 goto out;
1988         }
1989 
1990         sock->sk->sk_allocation = GFP_ATOMIC;
1991 
1992         write_lock_bh(&sock->sk->sk_callback_lock);
1993         sock->sk->sk_user_data = sock->sk->sk_data_ready;
1994         sock->sk->sk_data_ready = o2net_listen_data_ready;
1995         write_unlock_bh(&sock->sk->sk_callback_lock);
1996 
1997         o2net_listen_sock = sock;
1998         INIT_WORK(&o2net_listen_work, o2net_accept_many);
1999 
2000         sock->sk->sk_reuse = 1;
2001         ret = sock->ops->bind(sock, (struct sockaddr *)&sin, sizeof(sin));
2002         if (ret < 0) {
2003                 mlog(ML_ERROR, "unable to bind socket at %pI4:%u, "
2004                      "ret=%d\n", &addr, ntohs(port), ret);
2005                 goto out;
2006         }
2007 
2008         ret = sock->ops->listen(sock, 64);
2009         if (ret < 0) {
2010                 mlog(ML_ERROR, "unable to listen on %pI4:%u, ret=%d\n",
2011                      &addr, ntohs(port), ret);
2012         }
2013 
2014 out:
2015         if (ret) {
2016                 o2net_listen_sock = NULL;
2017                 if (sock)
2018                         sock_release(sock);
2019         }
2020         return ret;
2021 }
2022 
2023 /*
2024  * called from node manager when we should bring up our network listening
2025  * socket.  node manager handles all the serialization to only call this
2026  * once and to match it with o2net_stop_listening().  note,
2027  * o2nm_this_node() doesn't work yet as we're being called while it
2028  * is being set up.
2029  */
2030 int o2net_start_listening(struct o2nm_node *node)
2031 {
2032         int ret = 0;
2033 
2034         BUG_ON(o2net_wq != NULL);
2035         BUG_ON(o2net_listen_sock != NULL);
2036 
2037         mlog(ML_KTHREAD, "starting o2net thread...\n");
2038         o2net_wq = create_singlethread_workqueue("o2net");
2039         if (o2net_wq == NULL) {
2040                 mlog(ML_ERROR, "unable to launch o2net thread\n");
2041                 return -ENOMEM; /* ? */
2042         }
2043 
2044         ret = o2net_open_listening_sock(node->nd_ipv4_address,
2045                                         node->nd_ipv4_port);
2046         if (ret) {
2047                 destroy_workqueue(o2net_wq);
2048                 o2net_wq = NULL;
2049         } else
2050                 o2quo_conn_up(node->nd_num);
2051 
2052         return ret;
2053 }
2054 
2055 /* again, o2nm_this_node() doesn't work here as we're involved in
2056  * tearing it down */
2057 void o2net_stop_listening(struct o2nm_node *node)
2058 {
2059         struct socket *sock = o2net_listen_sock;
2060         size_t i;
2061 
2062         BUG_ON(o2net_wq == NULL);
2063         BUG_ON(o2net_listen_sock == NULL);
2064 
2065         /* stop the listening socket from generating work */
2066         write_lock_bh(&sock->sk->sk_callback_lock);
2067         sock->sk->sk_data_ready = sock->sk->sk_user_data;
2068         sock->sk->sk_user_data = NULL;
2069         write_unlock_bh(&sock->sk->sk_callback_lock);
2070 
2071         for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
2072                 struct o2nm_node *node = o2nm_get_node_by_num(i);
2073                 if (node) {
2074                         o2net_disconnect_node(node);
2075                         o2nm_node_put(node);
2076                 }
2077         }
2078 
2079         /* finish all work and tear down the work queue */
2080         mlog(ML_KTHREAD, "waiting for o2net thread to exit....\n");
2081         destroy_workqueue(o2net_wq);
2082         o2net_wq = NULL;
2083 
2084         sock_release(o2net_listen_sock);
2085         o2net_listen_sock = NULL;
2086 
2087         o2quo_conn_err(node->nd_num);
2088 }
2089 
2090 /* ------------------------------------------------------------ */
2091 
2092 int o2net_init(void)
2093 {
2094         unsigned long i;
2095 
2096         o2quo_init();
2097 
2098         if (o2net_debugfs_init())
2099                 return -ENOMEM;
2100 
2101         o2net_hand = kzalloc(sizeof(struct o2net_handshake), GFP_KERNEL);
2102         o2net_keep_req = kzalloc(sizeof(struct o2net_msg), GFP_KERNEL);
2103         o2net_keep_resp = kzalloc(sizeof(struct o2net_msg), GFP_KERNEL);
2104         if (!o2net_hand || !o2net_keep_req || !o2net_keep_resp) {
2105                 kfree(o2net_hand);
2106                 kfree(o2net_keep_req);
2107                 kfree(o2net_keep_resp);
2108                 return -ENOMEM;
2109         }
2110 
2111         o2net_hand->protocol_version = cpu_to_be64(O2NET_PROTOCOL_VERSION);
2112         o2net_hand->connector_id = cpu_to_be64(1);
2113 
2114         o2net_keep_req->magic = cpu_to_be16(O2NET_MSG_KEEP_REQ_MAGIC);
2115         o2net_keep_resp->magic = cpu_to_be16(O2NET_MSG_KEEP_RESP_MAGIC);
2116 
2117         for (i = 0; i < ARRAY_SIZE(o2net_nodes); i++) {
2118                 struct o2net_node *nn = o2net_nn_from_num(i);
2119 
2120                 atomic_set(&nn->nn_timeout, 0);
2121                 spin_lock_init(&nn->nn_lock);
2122                 INIT_DELAYED_WORK(&nn->nn_connect_work, o2net_start_connect);
2123                 INIT_DELAYED_WORK(&nn->nn_connect_expired,
2124                                   o2net_connect_expired);
2125                 INIT_DELAYED_WORK(&nn->nn_still_up, o2net_still_up);
2126                 /* until we see hb from a node we'll return einval */
2127                 nn->nn_persistent_error = -ENOTCONN;
2128                 init_waitqueue_head(&nn->nn_sc_wq);
2129                 idr_init(&nn->nn_status_idr);
2130                 INIT_LIST_HEAD(&nn->nn_status_list);
2131         }
2132 
2133         return 0;
2134 }
2135 
2136 void o2net_exit(void)
2137 {
2138         o2quo_exit();
2139         kfree(o2net_hand);
2140         kfree(o2net_keep_req);
2141         kfree(o2net_keep_resp);
2142         o2net_debugfs_exit();
2143 }
2144 

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