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LU-9019 lnet: move ping and delay injection to time64_t
[fs/lustre-release.git] / lnet / lnet / router.c
1 /*
2  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
3  *
4  * Copyright (c) 2011, 2017, Intel Corporation.
5  *
6  *   This file is part of Lustre, https://wiki.hpdd.intel.com/
7  *
8  *   Portals is free software; you can redistribute it and/or
9  *   modify it under the terms of version 2 of the GNU General Public
10  *   License as published by the Free Software Foundation.
11  *
12  *   Portals 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
15  *   GNU General Public License for more details.
16  *
17  *   You should have received a copy of the GNU General Public License
18  *   along with Portals; if not, write to the Free Software
19  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20  *
21  */
22
23 #define DEBUG_SUBSYSTEM S_LNET
24 #include <lnet/lib-lnet.h>
25
26 #define LNET_NRB_TINY_MIN       512     /* min value for each CPT */
27 #define LNET_NRB_TINY           (LNET_NRB_TINY_MIN * 4)
28 #define LNET_NRB_SMALL_MIN      4096    /* min value for each CPT */
29 #define LNET_NRB_SMALL          (LNET_NRB_SMALL_MIN * 4)
30 #define LNET_NRB_SMALL_PAGES    1
31 #define LNET_NRB_LARGE_MIN      256     /* min value for each CPT */
32 #define LNET_NRB_LARGE          (LNET_NRB_LARGE_MIN * 4)
33 #define LNET_NRB_LARGE_PAGES    ((LNET_MTU + PAGE_SIZE - 1) >> \
34                                   PAGE_SHIFT)
35
36 static char *forwarding = "";
37 module_param(forwarding, charp, 0444);
38 MODULE_PARM_DESC(forwarding, "Explicitly enable/disable forwarding between networks");
39
40 static int tiny_router_buffers;
41 module_param(tiny_router_buffers, int, 0444);
42 MODULE_PARM_DESC(tiny_router_buffers, "# of 0 payload messages to buffer in the router");
43 static int small_router_buffers;
44 module_param(small_router_buffers, int, 0444);
45 MODULE_PARM_DESC(small_router_buffers, "# of small (1 page) messages to buffer in the router");
46 static int large_router_buffers;
47 module_param(large_router_buffers, int, 0444);
48 MODULE_PARM_DESC(large_router_buffers, "# of large messages to buffer in the router");
49 static int peer_buffer_credits;
50 module_param(peer_buffer_credits, int, 0444);
51 MODULE_PARM_DESC(peer_buffer_credits, "# router buffer credits per peer");
52
53 static int auto_down = 1;
54 module_param(auto_down, int, 0444);
55 MODULE_PARM_DESC(auto_down, "Automatically mark peers down on comms error");
56
57 int
58 lnet_peer_buffer_credits(struct lnet_net *net)
59 {
60         /* NI option overrides LNet default */
61         if (net->net_tunables.lct_peer_rtr_credits > 0)
62                 return net->net_tunables.lct_peer_rtr_credits;
63         if (peer_buffer_credits > 0)
64                 return peer_buffer_credits;
65
66         /* As an approximation, allow this peer the same number of router
67          * buffers as it is allowed outstanding sends */
68         return net->net_tunables.lct_peer_tx_credits;
69 }
70
71 /* forward ref's */
72 static int lnet_router_checker(void *);
73
74 static int check_routers_before_use;
75 module_param(check_routers_before_use, int, 0444);
76 MODULE_PARM_DESC(check_routers_before_use, "Assume routers are down and ping them before use");
77
78 int avoid_asym_router_failure = 1;
79 module_param(avoid_asym_router_failure, int, 0644);
80 MODULE_PARM_DESC(avoid_asym_router_failure, "Avoid asymmetrical router failures (0 to disable)");
81
82 static int dead_router_check_interval = 60;
83 module_param(dead_router_check_interval, int, 0644);
84 MODULE_PARM_DESC(dead_router_check_interval, "Seconds between dead router health checks (<= 0 to disable)");
85
86 static int live_router_check_interval = 60;
87 module_param(live_router_check_interval, int, 0644);
88 MODULE_PARM_DESC(live_router_check_interval, "Seconds between live router health checks (<= 0 to disable)");
89
90 static int router_ping_timeout = 50;
91 module_param(router_ping_timeout, int, 0644);
92 MODULE_PARM_DESC(router_ping_timeout, "Seconds to wait for the reply to a router health query");
93
94 int
95 lnet_peers_start_down(void)
96 {
97         return check_routers_before_use;
98 }
99
100 void
101 lnet_notify_locked(struct lnet_peer_ni *lp, int notifylnd, int alive,
102                    time64_t when)
103 {
104         if (lp->lpni_timestamp > when) { /* out of date information */
105                 CDEBUG(D_NET, "Out of date\n");
106                 return;
107         }
108
109         /*
110          * This function can be called with different cpt locks being
111          * held. lpni_alive_count modification needs to be properly protected.
112          * Significant reads to lpni_alive_count are also protected with
113          * the same lock
114          */
115         spin_lock(&lp->lpni_lock);
116
117         lp->lpni_timestamp = when; /* update timestamp */
118         lp->lpni_ping_deadline = 0;               /* disable ping timeout */
119
120         if (lp->lpni_alive_count != 0 &&          /* got old news */
121             (!lp->lpni_alive) == (!alive)) {      /* new date for old news */
122                 spin_unlock(&lp->lpni_lock);
123                 CDEBUG(D_NET, "Old news\n");
124                 return;
125         }
126
127         /* Flag that notification is outstanding */
128
129         lp->lpni_alive_count++;
130         lp->lpni_alive = (alive) ? 1 : 0;
131         lp->lpni_notify = 1;
132         lp->lpni_notifylnd = notifylnd;
133         if (lp->lpni_alive)
134                 lp->lpni_ping_feats = LNET_PING_FEAT_INVAL; /* reset */
135
136         spin_unlock(&lp->lpni_lock);
137
138         CDEBUG(D_NET, "set %s %d\n", libcfs_nid2str(lp->lpni_nid), alive);
139 }
140
141 /*
142  * This function will always be called with lp->lpni_cpt lock held.
143  */
144 static void
145 lnet_ni_notify_locked(struct lnet_ni *ni, struct lnet_peer_ni *lp)
146 {
147         int alive;
148         int notifylnd;
149
150         /* Notify only in 1 thread at any time to ensure ordered notification.
151          * NB individual events can be missed; the only guarantee is that you
152          * always get the most recent news */
153
154         spin_lock(&lp->lpni_lock);
155
156         if (lp->lpni_notifying || ni == NULL) {
157                 spin_unlock(&lp->lpni_lock);
158                 return;
159         }
160
161         lp->lpni_notifying = 1;
162
163         /*
164          * lp->lpni_notify needs to be protected because it can be set in
165          * lnet_notify_locked().
166          */
167         while (lp->lpni_notify) {
168                 alive     = lp->lpni_alive;
169                 notifylnd = lp->lpni_notifylnd;
170
171                 lp->lpni_notifylnd = 0;
172                 lp->lpni_notify    = 0;
173
174                 if (notifylnd && ni->ni_net->net_lnd->lnd_notify != NULL) {
175                         spin_unlock(&lp->lpni_lock);
176                         lnet_net_unlock(lp->lpni_cpt);
177
178                         /* A new notification could happen now; I'll handle it
179                          * when control returns to me */
180
181                         (ni->ni_net->net_lnd->lnd_notify)(ni, lp->lpni_nid,
182                                                           alive);
183
184                         lnet_net_lock(lp->lpni_cpt);
185                         spin_lock(&lp->lpni_lock);
186                 }
187         }
188
189         lp->lpni_notifying = 0;
190         spin_unlock(&lp->lpni_lock);
191 }
192
193 static void
194 lnet_rtr_addref_locked(struct lnet_peer_ni *lp)
195 {
196         LASSERT(atomic_read(&lp->lpni_refcount) > 0);
197         LASSERT(lp->lpni_rtr_refcount >= 0);
198
199         /* lnet_net_lock must be exclusively locked */
200         lp->lpni_rtr_refcount++;
201         if (lp->lpni_rtr_refcount == 1) {
202                 struct list_head *pos;
203
204                 /* a simple insertion sort */
205                 list_for_each_prev(pos, &the_lnet.ln_routers) {
206                         struct lnet_peer_ni *rtr;
207
208                         rtr = list_entry(pos, struct lnet_peer_ni,
209                                          lpni_rtr_list);
210                         if (rtr->lpni_nid < lp->lpni_nid)
211                                 break;
212                 }
213
214                 list_add(&lp->lpni_rtr_list, pos);
215                 /* addref for the_lnet.ln_routers */
216                 lnet_peer_ni_addref_locked(lp);
217                 the_lnet.ln_routers_version++;
218         }
219 }
220
221 static void
222 lnet_rtr_decref_locked(struct lnet_peer_ni *lp)
223 {
224         LASSERT(atomic_read(&lp->lpni_refcount) > 0);
225         LASSERT(lp->lpni_rtr_refcount > 0);
226
227         /* lnet_net_lock must be exclusively locked */
228         lp->lpni_rtr_refcount--;
229         if (lp->lpni_rtr_refcount == 0) {
230                 LASSERT(list_empty(&lp->lpni_routes));
231
232                 if (lp->lpni_rcd != NULL) {
233                         list_add(&lp->lpni_rcd->rcd_list,
234                                  &the_lnet.ln_rcd_deathrow);
235                         lp->lpni_rcd = NULL;
236                 }
237
238                 list_del(&lp->lpni_rtr_list);
239                 /* decref for the_lnet.ln_routers */
240                 lnet_peer_ni_decref_locked(lp);
241                 the_lnet.ln_routers_version++;
242         }
243 }
244
245 struct lnet_remotenet *
246 lnet_find_rnet_locked(__u32 net)
247 {
248         struct lnet_remotenet *rnet;
249         struct list_head *tmp;
250         struct list_head *rn_list;
251
252         LASSERT(the_lnet.ln_state == LNET_STATE_RUNNING);
253
254         rn_list = lnet_net2rnethash(net);
255         list_for_each(tmp, rn_list) {
256                 rnet = list_entry(tmp, struct lnet_remotenet, lrn_list);
257
258                 if (rnet->lrn_net == net)
259                         return rnet;
260         }
261         return NULL;
262 }
263
264 static void lnet_shuffle_seed(void)
265 {
266         static int seeded;
267         __u32 lnd_type;
268         __u32 seed[2];
269         struct timespec64 ts;
270         struct lnet_ni *ni = NULL;
271
272         if (seeded)
273                 return;
274
275         cfs_get_random_bytes(seed, sizeof(seed));
276
277         /* Nodes with small feet have little entropy
278          * the NID for this node gives the most entropy in the low bits */
279         while ((ni = lnet_get_next_ni_locked(NULL, ni))) {
280                 lnd_type = LNET_NETTYP(LNET_NIDNET(ni->ni_nid));
281
282                 if (lnd_type != LOLND)
283                         seed[0] ^= (LNET_NIDADDR(ni->ni_nid) | lnd_type);
284         }
285
286         ktime_get_ts64(&ts);
287         cfs_srand(ts.tv_sec ^ seed[0], ts.tv_nsec ^ seed[1]);
288         seeded = 1;
289         return;
290 }
291
292 /* NB expects LNET_LOCK held */
293 static void
294 lnet_add_route_to_rnet(struct lnet_remotenet *rnet, struct lnet_route *route)
295 {
296         unsigned int      len = 0;
297         unsigned int      offset = 0;
298         struct list_head *e;
299
300         lnet_shuffle_seed();
301
302         list_for_each(e, &rnet->lrn_routes) {
303                 len++;
304         }
305
306         /* len+1 positions to add a new entry, also prevents division by 0 */
307         offset = cfs_rand() % (len + 1);
308         list_for_each(e, &rnet->lrn_routes) {
309                 if (offset == 0)
310                         break;
311                 offset--;
312         }
313         list_add(&route->lr_list, e);
314         list_add(&route->lr_gwlist, &route->lr_gateway->lpni_routes);
315
316         the_lnet.ln_remote_nets_version++;
317         lnet_rtr_addref_locked(route->lr_gateway);
318 }
319
320 int
321 lnet_add_route(__u32 net, __u32 hops, lnet_nid_t gateway,
322                unsigned int priority)
323 {
324         struct list_head        *e;
325         struct lnet_remotenet   *rnet;
326         struct lnet_remotenet   *rnet2;
327         struct lnet_route               *route;
328         struct lnet_ni          *ni;
329         struct lnet_peer_ni     *lpni;
330         int                     add_route;
331         int                     rc;
332
333         CDEBUG(D_NET, "Add route: net %s hops %d priority %u gw %s\n",
334                libcfs_net2str(net), hops, priority, libcfs_nid2str(gateway));
335
336         if (gateway == LNET_NID_ANY ||
337             LNET_NETTYP(LNET_NIDNET(gateway)) == LOLND ||
338             net == LNET_NIDNET(LNET_NID_ANY) ||
339             LNET_NETTYP(net) == LOLND ||
340             LNET_NIDNET(gateway) == net ||
341             (hops != LNET_UNDEFINED_HOPS && (hops < 1 || hops > 255)))
342                 return -EINVAL;
343
344         if (lnet_islocalnet(net))       /* it's a local network */
345                 return -EEXIST;
346
347         /* Assume net, route, all new */
348         LIBCFS_ALLOC(route, sizeof(*route));
349         LIBCFS_ALLOC(rnet, sizeof(*rnet));
350         if (route == NULL || rnet == NULL) {
351                 CERROR("Out of memory creating route %s %d %s\n",
352                        libcfs_net2str(net), hops, libcfs_nid2str(gateway));
353                 if (route != NULL)
354                         LIBCFS_FREE(route, sizeof(*route));
355                 if (rnet != NULL)
356                         LIBCFS_FREE(rnet, sizeof(*rnet));
357                 return -ENOMEM;
358         }
359
360         INIT_LIST_HEAD(&rnet->lrn_routes);
361         rnet->lrn_net = net;
362         route->lr_hops = hops;
363         route->lr_net = net;
364         route->lr_priority = priority;
365
366         lnet_net_lock(LNET_LOCK_EX);
367
368         lpni = lnet_nid2peerni_ex(gateway, LNET_LOCK_EX);
369         if (IS_ERR(lpni)) {
370                 lnet_net_unlock(LNET_LOCK_EX);
371
372                 LIBCFS_FREE(route, sizeof(*route));
373                 LIBCFS_FREE(rnet, sizeof(*rnet));
374
375                 rc = PTR_ERR(lpni);
376                 if (rc == -EHOSTUNREACH) /* gateway is not on a local net. */
377                         return rc;       /* ignore the route entry */
378                 CERROR("Error %d creating route %s %d %s\n", rc,
379                         libcfs_net2str(net), hops,
380                         libcfs_nid2str(gateway));
381                 return rc;
382         }
383         route->lr_gateway = lpni;
384         LASSERT(the_lnet.ln_state == LNET_STATE_RUNNING);
385
386         rnet2 = lnet_find_rnet_locked(net);
387         if (rnet2 == NULL) {
388                 /* new network */
389                 list_add_tail(&rnet->lrn_list, lnet_net2rnethash(net));
390                 rnet2 = rnet;
391         }
392
393         /* Search for a duplicate route (it's a NOOP if it is) */
394         add_route = 1;
395         list_for_each(e, &rnet2->lrn_routes) {
396                 struct lnet_route *route2;
397
398                 route2 = list_entry(e, struct lnet_route, lr_list);
399                 if (route2->lr_gateway == route->lr_gateway) {
400                         add_route = 0;
401                         break;
402                 }
403
404                 /* our lookups must be true */
405                 LASSERT(route2->lr_gateway->lpni_nid != gateway);
406         }
407
408         if (add_route) {
409                 lnet_peer_ni_addref_locked(route->lr_gateway); /* +1 for notify */
410                 lnet_add_route_to_rnet(rnet2, route);
411
412                 ni = lnet_get_next_ni_locked(route->lr_gateway->lpni_net, NULL);
413                 lnet_net_unlock(LNET_LOCK_EX);
414
415                 /* XXX Assume alive */
416                 if (ni->ni_net->net_lnd->lnd_notify != NULL)
417                         (ni->ni_net->net_lnd->lnd_notify)(ni, gateway, 1);
418
419                 lnet_net_lock(LNET_LOCK_EX);
420         }
421
422         /* -1 for notify or !add_route */
423         lnet_peer_ni_decref_locked(route->lr_gateway);
424         lnet_net_unlock(LNET_LOCK_EX);
425
426         rc = 0;
427
428         if (!add_route) {
429                 rc = -EEXIST;
430                 LIBCFS_FREE(route, sizeof(*route));
431         }
432
433         if (rnet != rnet2)
434                 LIBCFS_FREE(rnet, sizeof(*rnet));
435
436         /* indicate to startup the router checker if configured */
437         wake_up(&the_lnet.ln_rc_waitq);
438
439         return rc;
440 }
441
442 int
443 lnet_check_routes(void)
444 {
445         struct lnet_remotenet *rnet;
446         struct lnet_route        *route;
447         struct lnet_route        *route2;
448         struct list_head *e1;
449         struct list_head *e2;
450         int               cpt;
451         struct list_head *rn_list;
452         int               i;
453
454         cpt = lnet_net_lock_current();
455
456         for (i = 0; i < LNET_REMOTE_NETS_HASH_SIZE; i++) {
457                 rn_list = &the_lnet.ln_remote_nets_hash[i];
458                 list_for_each(e1, rn_list) {
459                         rnet = list_entry(e1, struct lnet_remotenet, lrn_list);
460
461                         route2 = NULL;
462                         list_for_each(e2, &rnet->lrn_routes) {
463                                 lnet_nid_t      nid1;
464                                 lnet_nid_t      nid2;
465                                 int             net;
466
467                                 route = list_entry(e2, struct lnet_route,
468                                                    lr_list);
469
470                                 if (route2 == NULL) {
471                                         route2 = route;
472                                         continue;
473                                 }
474
475                                 if (route->lr_gateway->lpni_net ==
476                                     route2->lr_gateway->lpni_net)
477                                         continue;
478
479                                 nid1 = route->lr_gateway->lpni_nid;
480                                 nid2 = route2->lr_gateway->lpni_nid;
481                                 net = rnet->lrn_net;
482
483                                 lnet_net_unlock(cpt);
484
485                                 CERROR("Routes to %s via %s and %s not "
486                                        "supported\n",
487                                        libcfs_net2str(net),
488                                        libcfs_nid2str(nid1),
489                                        libcfs_nid2str(nid2));
490                                 return -EINVAL;
491                         }
492                 }
493         }
494
495         lnet_net_unlock(cpt);
496         return 0;
497 }
498
499 int
500 lnet_del_route(__u32 net, lnet_nid_t gw_nid)
501 {
502         struct lnet_peer_ni     *gateway;
503         struct lnet_remotenet   *rnet;
504         struct lnet_route               *route;
505         struct list_head        *e1;
506         struct list_head        *e2;
507         int                     rc = -ENOENT;
508         struct list_head        *rn_list;
509         int                     idx = 0;
510
511         CDEBUG(D_NET, "Del route: net %s : gw %s\n",
512                libcfs_net2str(net), libcfs_nid2str(gw_nid));
513
514         /* NB Caller may specify either all routes via the given gateway
515          * or a specific route entry actual NIDs) */
516
517         lnet_net_lock(LNET_LOCK_EX);
518         if (net == LNET_NIDNET(LNET_NID_ANY))
519                 rn_list = &the_lnet.ln_remote_nets_hash[0];
520         else
521                 rn_list = lnet_net2rnethash(net);
522
523 again:
524         list_for_each(e1, rn_list) {
525                 rnet = list_entry(e1, struct lnet_remotenet, lrn_list);
526
527                 if (!(net == LNET_NIDNET(LNET_NID_ANY) ||
528                         net == rnet->lrn_net))
529                         continue;
530
531                 list_for_each(e2, &rnet->lrn_routes) {
532                         route = list_entry(e2, struct lnet_route, lr_list);
533
534                         gateway = route->lr_gateway;
535                         if (!(gw_nid == LNET_NID_ANY ||
536                               gw_nid == gateway->lpni_nid))
537                                 continue;
538
539                         list_del(&route->lr_list);
540                         list_del(&route->lr_gwlist);
541                         the_lnet.ln_remote_nets_version++;
542
543                         if (list_empty(&rnet->lrn_routes))
544                                 list_del(&rnet->lrn_list);
545                         else
546                                 rnet = NULL;
547
548                         lnet_rtr_decref_locked(gateway);
549                         lnet_peer_ni_decref_locked(gateway);
550
551                         lnet_net_unlock(LNET_LOCK_EX);
552
553                         LIBCFS_FREE(route, sizeof(*route));
554
555                         if (rnet != NULL)
556                                 LIBCFS_FREE(rnet, sizeof(*rnet));
557
558                         rc = 0;
559                         lnet_net_lock(LNET_LOCK_EX);
560                         goto again;
561                 }
562         }
563
564         if (net == LNET_NIDNET(LNET_NID_ANY) &&
565             ++idx < LNET_REMOTE_NETS_HASH_SIZE) {
566                 rn_list = &the_lnet.ln_remote_nets_hash[idx];
567                 goto again;
568         }
569         lnet_net_unlock(LNET_LOCK_EX);
570
571         return rc;
572 }
573
574 void
575 lnet_destroy_routes (void)
576 {
577         lnet_del_route(LNET_NIDNET(LNET_NID_ANY), LNET_NID_ANY);
578 }
579
580 int lnet_get_rtr_pool_cfg(int idx, struct lnet_ioctl_pool_cfg *pool_cfg)
581 {
582         int i, rc = -ENOENT, j;
583
584         if (the_lnet.ln_rtrpools == NULL)
585                 return rc;
586
587         for (i = 0; i < LNET_NRBPOOLS; i++) {
588                 struct lnet_rtrbufpool *rbp;
589
590                 lnet_net_lock(LNET_LOCK_EX);
591                 cfs_percpt_for_each(rbp, j, the_lnet.ln_rtrpools) {
592                         if (i++ != idx)
593                                 continue;
594
595                         pool_cfg->pl_pools[i].pl_npages = rbp[i].rbp_npages;
596                         pool_cfg->pl_pools[i].pl_nbuffers = rbp[i].rbp_nbuffers;
597                         pool_cfg->pl_pools[i].pl_credits = rbp[i].rbp_credits;
598                         pool_cfg->pl_pools[i].pl_mincredits = rbp[i].rbp_mincredits;
599                         rc = 0;
600                         break;
601                 }
602                 lnet_net_unlock(LNET_LOCK_EX);
603         }
604
605         lnet_net_lock(LNET_LOCK_EX);
606         pool_cfg->pl_routing = the_lnet.ln_routing;
607         lnet_net_unlock(LNET_LOCK_EX);
608
609         return rc;
610 }
611
612 int
613 lnet_get_route(int idx, __u32 *net, __u32 *hops,
614                lnet_nid_t *gateway, __u32 *alive, __u32 *priority)
615 {
616         struct list_head *e1;
617         struct list_head *e2;
618         struct lnet_remotenet *rnet;
619         struct lnet_route        *route;
620         int               cpt;
621         int               i;
622         struct list_head *rn_list;
623
624         cpt = lnet_net_lock_current();
625
626         for (i = 0; i < LNET_REMOTE_NETS_HASH_SIZE; i++) {
627                 rn_list = &the_lnet.ln_remote_nets_hash[i];
628                 list_for_each(e1, rn_list) {
629                         rnet = list_entry(e1, struct lnet_remotenet, lrn_list);
630
631                         list_for_each(e2, &rnet->lrn_routes) {
632                                 route = list_entry(e2, struct lnet_route,
633                                                    lr_list);
634
635                                 if (idx-- == 0) {
636                                         *net      = rnet->lrn_net;
637                                         *hops     = route->lr_hops;
638                                         *priority = route->lr_priority;
639                                         *gateway  = route->lr_gateway->lpni_nid;
640                                         *alive    = lnet_is_route_alive(route);
641                                         lnet_net_unlock(cpt);
642                                         return 0;
643                                 }
644                         }
645                 }
646         }
647
648         lnet_net_unlock(cpt);
649         return -ENOENT;
650 }
651
652 void
653 lnet_swap_pinginfo(struct lnet_ping_buffer *pbuf)
654 {
655         struct lnet_ni_status *stat;
656         int nnis;
657         int i;
658
659         __swab32s(&pbuf->pb_info.pi_magic);
660         __swab32s(&pbuf->pb_info.pi_features);
661         __swab32s(&pbuf->pb_info.pi_pid);
662         __swab32s(&pbuf->pb_info.pi_nnis);
663         nnis = pbuf->pb_info.pi_nnis;
664         if (nnis > pbuf->pb_nnis)
665                 nnis = pbuf->pb_nnis;
666         for (i = 0; i < nnis; i++) {
667                 stat = &pbuf->pb_info.pi_ni[i];
668                 __swab64s(&stat->ns_nid);
669                 __swab32s(&stat->ns_status);
670         }
671         return;
672 }
673
674 /**
675  * parse router-checker pinginfo, record number of down NIs for remote
676  * networks on that router.
677  */
678 static void
679 lnet_parse_rc_info(struct lnet_rc_data *rcd)
680 {
681         struct lnet_ping_buffer *pbuf = rcd->rcd_pingbuffer;
682         struct lnet_peer_ni     *gw   = rcd->rcd_gateway;
683         struct lnet_route               *rte;
684         int                     nnis;
685
686         if (!gw->lpni_alive || !pbuf)
687                 return;
688
689         /*
690          * Protect gw->lpni_ping_feats. This can be set from
691          * lnet_notify_locked with different locks being held
692          */
693         spin_lock(&gw->lpni_lock);
694
695         if (pbuf->pb_info.pi_magic == __swab32(LNET_PROTO_PING_MAGIC))
696                 lnet_swap_pinginfo(pbuf);
697
698         /* NB always racing with network! */
699         if (pbuf->pb_info.pi_magic != LNET_PROTO_PING_MAGIC) {
700                 CDEBUG(D_NET, "%s: Unexpected magic %08x\n",
701                        libcfs_nid2str(gw->lpni_nid), pbuf->pb_info.pi_magic);
702                 gw->lpni_ping_feats = LNET_PING_FEAT_INVAL;
703                 goto out;
704         }
705
706         gw->lpni_ping_feats = pbuf->pb_info.pi_features;
707
708         /* Without NI status info there's nothing more to do. */
709         if ((gw->lpni_ping_feats & LNET_PING_FEAT_NI_STATUS) == 0)
710                 goto out;
711
712         /* Determine the number of NIs for which there is data. */
713         nnis = pbuf->pb_info.pi_nnis;
714         if (pbuf->pb_nnis < nnis) {
715                 if (rcd->rcd_nnis < nnis)
716                         rcd->rcd_nnis = nnis;
717                 nnis = pbuf->pb_nnis;
718         }
719
720         list_for_each_entry(rte, &gw->lpni_routes, lr_gwlist) {
721                 int     down = 0;
722                 int     up = 0;
723                 int     i;
724
725                 /* If routing disabled then the route is down. */
726                 if ((gw->lpni_ping_feats & LNET_PING_FEAT_RTE_DISABLED) != 0) {
727                         rte->lr_downis = 1;
728                         continue;
729                 }
730
731                 for (i = 0; i < nnis; i++) {
732                         struct lnet_ni_status *stat = &pbuf->pb_info.pi_ni[i];
733                         lnet_nid_t       nid = stat->ns_nid;
734
735                         if (nid == LNET_NID_ANY) {
736                                 CDEBUG(D_NET, "%s: unexpected LNET_NID_ANY\n",
737                                        libcfs_nid2str(gw->lpni_nid));
738                                 gw->lpni_ping_feats = LNET_PING_FEAT_INVAL;
739                                 goto out;
740                         }
741
742                         if (LNET_NETTYP(LNET_NIDNET(nid)) == LOLND)
743                                 continue;
744
745                         if (stat->ns_status == LNET_NI_STATUS_DOWN) {
746                                 down++;
747                                 continue;
748                         }
749
750                         if (stat->ns_status == LNET_NI_STATUS_UP) {
751                                 if (LNET_NIDNET(nid) == rte->lr_net) {
752                                         up = 1;
753                                         break;
754                                 }
755                                 continue;
756                         }
757
758                         CDEBUG(D_NET, "%s: Unexpected status 0x%x\n",
759                                libcfs_nid2str(gw->lpni_nid), stat->ns_status);
760                         gw->lpni_ping_feats = LNET_PING_FEAT_INVAL;
761                         goto out;
762                 }
763
764                 if (up) { /* ignore downed NIs if NI for dest network is up */
765                         rte->lr_downis = 0;
766                         continue;
767                 }
768                 /* if @down is zero and this route is single-hop, it means
769                  * we can't find NI for target network */
770                 if (down == 0 && rte->lr_hops == 1)
771                         down = 1;
772
773                 rte->lr_downis = down;
774         }
775 out:
776         spin_unlock(&gw->lpni_lock);
777 }
778
779 static void
780 lnet_router_checker_event(struct lnet_event *event)
781 {
782         struct lnet_rc_data *rcd = event->md.user_ptr;
783         struct lnet_peer_ni *lp;
784
785         LASSERT(rcd != NULL);
786
787         if (event->unlinked) {
788                 LNetInvalidateMDHandle(&rcd->rcd_mdh);
789                 return;
790         }
791
792         LASSERT(event->type == LNET_EVENT_SEND ||
793                 event->type == LNET_EVENT_REPLY);
794
795         lp = rcd->rcd_gateway;
796         LASSERT(lp != NULL);
797
798          /* NB: it's called with holding lnet_res_lock, we have a few
799           * places need to hold both locks at the same time, please take
800           * care of lock ordering */
801         lnet_net_lock(lp->lpni_cpt);
802         if (!lnet_isrouter(lp) || lp->lpni_rcd != rcd) {
803                 /* ignore if no longer a router or rcd is replaced */
804                 goto out;
805         }
806
807         if (event->type == LNET_EVENT_SEND) {
808                 lp->lpni_ping_notsent = 0;
809                 if (event->status == 0)
810                         goto out;
811         }
812
813         /* LNET_EVENT_REPLY */
814         /* A successful REPLY means the router is up.  If _any_ comms
815          * to the router fail I assume it's down (this will happen if
816          * we ping alive routers to try to detect router death before
817          * apps get burned). */
818
819         lnet_notify_locked(lp, 1, !event->status, ktime_get_seconds());
820         /* The router checker will wake up very shortly and do the
821          * actual notification.
822          * XXX If 'lp' stops being a router before then, it will still
823          * have the notification pending!!! */
824
825         if (avoid_asym_router_failure && event->status == 0)
826                 lnet_parse_rc_info(rcd);
827
828  out:
829         lnet_net_unlock(lp->lpni_cpt);
830 }
831
832 static void
833 lnet_wait_known_routerstate(void)
834 {
835         struct lnet_peer_ni *rtr;
836         struct list_head *entry;
837         int all_known;
838
839         LASSERT(the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING);
840
841         for (;;) {
842                 int cpt = lnet_net_lock_current();
843
844                 all_known = 1;
845                 list_for_each(entry, &the_lnet.ln_routers) {
846                         rtr = list_entry(entry, struct lnet_peer_ni,
847                                          lpni_rtr_list);
848
849                         spin_lock(&rtr->lpni_lock);
850
851                         if (rtr->lpni_alive_count == 0) {
852                                 all_known = 0;
853                                 spin_unlock(&rtr->lpni_lock);
854                                 break;
855                         }
856                         spin_unlock(&rtr->lpni_lock);
857                 }
858
859                 lnet_net_unlock(cpt);
860
861                 if (all_known)
862                         return;
863
864                 set_current_state(TASK_UNINTERRUPTIBLE);
865                 schedule_timeout(cfs_time_seconds(1));
866         }
867 }
868
869 void
870 lnet_router_ni_update_locked(struct lnet_peer_ni *gw, __u32 net)
871 {
872         struct lnet_route *rte;
873
874         if ((gw->lpni_ping_feats & LNET_PING_FEAT_NI_STATUS) != 0) {
875                 list_for_each_entry(rte, &gw->lpni_routes, lr_gwlist) {
876                         if (rte->lr_net == net) {
877                                 rte->lr_downis = 0;
878                                 break;
879                         }
880                 }
881         }
882 }
883
884 static void
885 lnet_update_ni_status_locked(void)
886 {
887         struct lnet_ni *ni = NULL;
888         time64_t now;
889         time64_t timeout;
890
891         LASSERT(the_lnet.ln_routing);
892
893         timeout = router_ping_timeout +
894                   MAX(live_router_check_interval, dead_router_check_interval);
895
896         now = ktime_get_real_seconds();
897         while ((ni = lnet_get_next_ni_locked(NULL, ni))) {
898                 if (ni->ni_net->net_lnd->lnd_type == LOLND)
899                         continue;
900
901                 if (now < ni->ni_last_alive + timeout)
902                         continue;
903
904                 lnet_ni_lock(ni);
905                 /* re-check with lock */
906                 if (now < ni->ni_last_alive + timeout) {
907                         lnet_ni_unlock(ni);
908                         continue;
909                 }
910
911                 LASSERT(ni->ni_status != NULL);
912
913                 if (ni->ni_status->ns_status != LNET_NI_STATUS_DOWN) {
914                         CDEBUG(D_NET, "NI(%s:%lld) status changed to down\n",
915                                libcfs_nid2str(ni->ni_nid), timeout);
916                         /* NB: so far, this is the only place to set
917                          * NI status to "down" */
918                         ni->ni_status->ns_status = LNET_NI_STATUS_DOWN;
919                 }
920                 lnet_ni_unlock(ni);
921         }
922 }
923
924 static void
925 lnet_destroy_rc_data(struct lnet_rc_data *rcd)
926 {
927         LASSERT(list_empty(&rcd->rcd_list));
928         /* detached from network */
929         LASSERT(LNetMDHandleIsInvalid(rcd->rcd_mdh));
930
931         if (rcd->rcd_gateway != NULL) {
932                 int cpt = rcd->rcd_gateway->lpni_cpt;
933
934                 lnet_net_lock(cpt);
935                 lnet_peer_ni_decref_locked(rcd->rcd_gateway);
936                 lnet_net_unlock(cpt);
937         }
938
939         if (rcd->rcd_pingbuffer != NULL)
940                 lnet_ping_buffer_decref(rcd->rcd_pingbuffer);
941
942         LIBCFS_FREE(rcd, sizeof(*rcd));
943 }
944
945 static struct lnet_rc_data *
946 lnet_update_rc_data_locked(struct lnet_peer_ni *gateway)
947 {
948         struct lnet_handle_md mdh;
949         struct lnet_rc_data *rcd;
950         struct lnet_ping_buffer *pbuf = NULL;
951         int nnis = LNET_INTERFACES_MIN;
952         int rc;
953         int i;
954
955         rcd = gateway->lpni_rcd;
956         if (rcd) {
957                 nnis = rcd->rcd_nnis;
958                 mdh = rcd->rcd_mdh;
959                 LNetInvalidateMDHandle(&rcd->rcd_mdh);
960                 pbuf = rcd->rcd_pingbuffer;
961                 rcd->rcd_pingbuffer = NULL;
962         } else {
963                 LNetInvalidateMDHandle(&mdh);
964         }
965
966         lnet_net_unlock(gateway->lpni_cpt);
967
968         if (rcd) {
969                 LNetMDUnlink(mdh);
970                 lnet_ping_buffer_decref(pbuf);
971         } else {
972                 LIBCFS_ALLOC(rcd, sizeof(*rcd));
973                 if (rcd == NULL)
974                         goto out;
975
976                 LNetInvalidateMDHandle(&rcd->rcd_mdh);
977                 INIT_LIST_HEAD(&rcd->rcd_list);
978                 rcd->rcd_nnis = nnis;
979         }
980
981         pbuf = lnet_ping_buffer_alloc(nnis, GFP_NOFS);
982         if (pbuf == NULL)
983                 goto out;
984
985         for (i = 0; i < nnis; i++) {
986                 pbuf->pb_info.pi_ni[i].ns_nid = LNET_NID_ANY;
987                 pbuf->pb_info.pi_ni[i].ns_status = LNET_NI_STATUS_INVALID;
988         }
989         rcd->rcd_pingbuffer = pbuf;
990
991         LASSERT(!LNetEQHandleIsInvalid(the_lnet.ln_rc_eqh));
992         rc = LNetMDBind((struct lnet_md){.start     = &pbuf->pb_info,
993                                     .user_ptr  = rcd,
994                                     .length    = LNET_PING_INFO_SIZE(nnis),
995                                     .threshold = LNET_MD_THRESH_INF,
996                                     .options   = LNET_MD_TRUNCATE,
997                                     .eq_handle = the_lnet.ln_rc_eqh},
998                         LNET_UNLINK,
999                         &rcd->rcd_mdh);
1000         if (rc < 0) {
1001                 CERROR("Can't bind MD: %d\n", rc);
1002                 goto out_ping_buffer_decref;
1003         }
1004         LASSERT(rc == 0);
1005
1006         lnet_net_lock(gateway->lpni_cpt);
1007         /* Check if this is still a router. */
1008         if (!lnet_isrouter(gateway))
1009                 goto out_unlock;
1010         /* Check if someone else installed router data. */
1011         if (gateway->lpni_rcd && gateway->lpni_rcd != rcd)
1012                 goto out_unlock;
1013
1014         /* Install and/or update the router data. */
1015         if (!gateway->lpni_rcd) {
1016                 lnet_peer_ni_addref_locked(gateway);
1017                 rcd->rcd_gateway = gateway;
1018                 gateway->lpni_rcd = rcd;
1019         }
1020         gateway->lpni_ping_notsent = 0;
1021
1022         return rcd;
1023
1024 out_unlock:
1025         lnet_net_unlock(gateway->lpni_cpt);
1026         rc = LNetMDUnlink(mdh);
1027         LASSERT(rc == 0);
1028 out_ping_buffer_decref:
1029         lnet_ping_buffer_decref(pbuf);
1030 out:
1031         if (rcd && rcd != gateway->lpni_rcd)
1032                 lnet_destroy_rc_data(rcd);
1033         lnet_net_lock(gateway->lpni_cpt);
1034         return gateway->lpni_rcd;
1035 }
1036
1037 static int
1038 lnet_router_check_interval(struct lnet_peer_ni *rtr)
1039 {
1040         int secs;
1041
1042         secs = rtr->lpni_alive ? live_router_check_interval :
1043                                dead_router_check_interval;
1044         if (secs < 0)
1045                 secs = 0;
1046
1047         return secs;
1048 }
1049
1050 static void
1051 lnet_ping_router_locked(struct lnet_peer_ni *rtr)
1052 {
1053         struct lnet_rc_data *rcd = NULL;
1054         time64_t now = ktime_get_seconds();
1055         time64_t secs;
1056         struct lnet_ni *ni;
1057
1058         lnet_peer_ni_addref_locked(rtr);
1059
1060         if (rtr->lpni_ping_deadline != 0 && /* ping timed out? */
1061             now >  rtr->lpni_ping_deadline)
1062                 lnet_notify_locked(rtr, 1, 0, now);
1063
1064         /* Run any outstanding notifications */
1065         ni = lnet_get_next_ni_locked(rtr->lpni_net, NULL);
1066         lnet_ni_notify_locked(ni, rtr);
1067
1068         if (!lnet_isrouter(rtr) ||
1069             the_lnet.ln_rc_state != LNET_RC_STATE_RUNNING) {
1070                 /* router table changed or router checker is shutting down */
1071                 lnet_peer_ni_decref_locked(rtr);
1072                 return;
1073         }
1074
1075         rcd = rtr->lpni_rcd;
1076         if (!rcd || rcd->rcd_nnis > rcd->rcd_pingbuffer->pb_nnis)
1077                 rcd = lnet_update_rc_data_locked(rtr);
1078         if (rcd == NULL)
1079                 return;
1080
1081         secs = lnet_router_check_interval(rtr);
1082
1083         CDEBUG(D_NET,
1084                "rtr %s %lld: deadline %lld ping_notsent %d alive %d "
1085                "alive_count %d lpni_ping_timestamp %lld\n",
1086                libcfs_nid2str(rtr->lpni_nid), secs,
1087                rtr->lpni_ping_deadline, rtr->lpni_ping_notsent,
1088                rtr->lpni_alive, rtr->lpni_alive_count, rtr->lpni_ping_timestamp);
1089
1090         if (secs != 0 && !rtr->lpni_ping_notsent &&
1091             now > rtr->lpni_ping_timestamp + secs) {
1092                 int               rc;
1093                 struct lnet_process_id id;
1094                 struct lnet_handle_md mdh;
1095
1096                 id.nid = rtr->lpni_nid;
1097                 id.pid = LNET_PID_LUSTRE;
1098                 CDEBUG(D_NET, "Check: %s\n", libcfs_id2str(id));
1099
1100                 rtr->lpni_ping_notsent   = 1;
1101                 rtr->lpni_ping_timestamp = now;
1102
1103                 mdh = rcd->rcd_mdh;
1104
1105                 if (rtr->lpni_ping_deadline == 0) {
1106                         rtr->lpni_ping_deadline = ktime_get_seconds() +
1107                                                   router_ping_timeout;
1108                 }
1109
1110                 lnet_net_unlock(rtr->lpni_cpt);
1111
1112                 rc = LNetGet(LNET_NID_ANY, mdh, id, LNET_RESERVED_PORTAL,
1113                              LNET_PROTO_PING_MATCHBITS, 0);
1114
1115                 lnet_net_lock(rtr->lpni_cpt);
1116                 if (rc != 0)
1117                         rtr->lpni_ping_notsent = 0; /* no event pending */
1118         }
1119
1120         lnet_peer_ni_decref_locked(rtr);
1121         return;
1122 }
1123
1124 int
1125 lnet_router_checker_start(void)
1126 {
1127         int                     rc;
1128         int                     eqsz = 0;
1129         struct task_struct     *task;
1130
1131         LASSERT(the_lnet.ln_rc_state == LNET_RC_STATE_SHUTDOWN);
1132
1133         if (check_routers_before_use &&
1134             dead_router_check_interval <= 0) {
1135                 LCONSOLE_ERROR_MSG(0x10a, "'dead_router_check_interval' must be"
1136                                    " set if 'check_routers_before_use' is set"
1137                                    "\n");
1138                 return -EINVAL;
1139         }
1140
1141         sema_init(&the_lnet.ln_rc_signal, 0);
1142
1143         rc = LNetEQAlloc(0, lnet_router_checker_event, &the_lnet.ln_rc_eqh);
1144         if (rc != 0) {
1145                 CERROR("Can't allocate EQ(%d): %d\n", eqsz, rc);
1146                 return -ENOMEM;
1147         }
1148
1149         the_lnet.ln_rc_state = LNET_RC_STATE_RUNNING;
1150         task = kthread_run(lnet_router_checker, NULL, "router_checker");
1151         if (IS_ERR(task)) {
1152                 rc = PTR_ERR(task);
1153                 CERROR("Can't start router checker thread: %d\n", rc);
1154                 /* block until event callback signals exit */
1155                 down(&the_lnet.ln_rc_signal);
1156                 rc = LNetEQFree(the_lnet.ln_rc_eqh);
1157                 LASSERT(rc == 0);
1158                 the_lnet.ln_rc_state = LNET_RC_STATE_SHUTDOWN;
1159                 return -ENOMEM;
1160         }
1161
1162         if (check_routers_before_use) {
1163                 /* Note that a helpful side-effect of pinging all known routers
1164                  * at startup is that it makes them drop stale connections they
1165                  * may have to a previous instance of me. */
1166                 lnet_wait_known_routerstate();
1167         }
1168
1169         return 0;
1170 }
1171
1172 void
1173 lnet_router_checker_stop (void)
1174 {
1175         int rc;
1176
1177         if (the_lnet.ln_rc_state == LNET_RC_STATE_SHUTDOWN)
1178                 return;
1179
1180         LASSERT (the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING);
1181         the_lnet.ln_rc_state = LNET_RC_STATE_STOPPING;
1182         /* wakeup the RC thread if it's sleeping */
1183         wake_up(&the_lnet.ln_rc_waitq);
1184
1185         /* block until event callback signals exit */
1186         down(&the_lnet.ln_rc_signal);
1187         LASSERT(the_lnet.ln_rc_state == LNET_RC_STATE_SHUTDOWN);
1188
1189         rc = LNetEQFree(the_lnet.ln_rc_eqh);
1190         LASSERT(rc == 0);
1191         return;
1192 }
1193
1194 static void
1195 lnet_prune_rc_data(int wait_unlink)
1196 {
1197         struct lnet_rc_data *rcd;
1198         struct lnet_rc_data *tmp;
1199         struct lnet_peer_ni *lp;
1200         struct list_head head;
1201         int i = 2;
1202
1203         if (likely(the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING &&
1204                    list_empty(&the_lnet.ln_rcd_deathrow) &&
1205                    list_empty(&the_lnet.ln_rcd_zombie)))
1206                 return;
1207
1208         INIT_LIST_HEAD(&head);
1209
1210         lnet_net_lock(LNET_LOCK_EX);
1211
1212         if (the_lnet.ln_rc_state != LNET_RC_STATE_RUNNING) {
1213                 /* router checker is stopping, prune all */
1214                 list_for_each_entry(lp, &the_lnet.ln_routers,
1215                                     lpni_rtr_list) {
1216                         if (lp->lpni_rcd == NULL)
1217                                 continue;
1218
1219                         LASSERT(list_empty(&lp->lpni_rcd->rcd_list));
1220                         list_add(&lp->lpni_rcd->rcd_list,
1221                                  &the_lnet.ln_rcd_deathrow);
1222                         lp->lpni_rcd = NULL;
1223                 }
1224         }
1225
1226         /* unlink all RCDs on deathrow list */
1227         list_splice_init(&the_lnet.ln_rcd_deathrow, &head);
1228
1229         if (!list_empty(&head)) {
1230                 lnet_net_unlock(LNET_LOCK_EX);
1231
1232                 list_for_each_entry(rcd, &head, rcd_list)
1233                         LNetMDUnlink(rcd->rcd_mdh);
1234
1235                 lnet_net_lock(LNET_LOCK_EX);
1236         }
1237
1238         list_splice_init(&head, &the_lnet.ln_rcd_zombie);
1239
1240         /* release all zombie RCDs */
1241         while (!list_empty(&the_lnet.ln_rcd_zombie)) {
1242                 list_for_each_entry_safe(rcd, tmp, &the_lnet.ln_rcd_zombie,
1243                                          rcd_list) {
1244                         if (LNetMDHandleIsInvalid(rcd->rcd_mdh))
1245                                 list_move(&rcd->rcd_list, &head);
1246                 }
1247
1248                 wait_unlink = wait_unlink &&
1249                               !list_empty(&the_lnet.ln_rcd_zombie);
1250
1251                 lnet_net_unlock(LNET_LOCK_EX);
1252
1253                 while (!list_empty(&head)) {
1254                         rcd = list_entry(head.next,
1255                                          struct lnet_rc_data, rcd_list);
1256                         list_del_init(&rcd->rcd_list);
1257                         lnet_destroy_rc_data(rcd);
1258                 }
1259
1260                 if (!wait_unlink)
1261                         return;
1262
1263                 i++;
1264                 CDEBUG(((i & (-i)) == i) ? D_WARNING : D_NET,
1265                        "Waiting for rc buffers to unlink\n");
1266                 set_current_state(TASK_UNINTERRUPTIBLE);
1267                 schedule_timeout(cfs_time_seconds(1) / 4);
1268
1269                 lnet_net_lock(LNET_LOCK_EX);
1270         }
1271
1272         lnet_net_unlock(LNET_LOCK_EX);
1273 }
1274
1275 /*
1276  * This function is called to check if the RC should block indefinitely.
1277  * It's called from lnet_router_checker() as well as being passed to
1278  * wait_event_interruptible() to avoid the lost wake_up problem.
1279  *
1280  * When it's called from wait_event_interruptible() it is necessary to
1281  * also not sleep if the rc state is not running to avoid a deadlock
1282  * when the system is shutting down
1283  */
1284 static inline bool
1285 lnet_router_checker_active(void)
1286 {
1287         if (the_lnet.ln_rc_state != LNET_RC_STATE_RUNNING)
1288                 return true;
1289
1290         /* Router Checker thread needs to run when routing is enabled in
1291          * order to call lnet_update_ni_status_locked() */
1292         if (the_lnet.ln_routing)
1293                 return true;
1294
1295         return !list_empty(&the_lnet.ln_routers) &&
1296                 (live_router_check_interval > 0 ||
1297                  dead_router_check_interval > 0);
1298 }
1299
1300 static int
1301 lnet_router_checker(void *arg)
1302 {
1303         struct lnet_peer_ni *rtr;
1304         struct list_head *entry;
1305
1306         cfs_block_allsigs();
1307
1308         while (the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING) {
1309                 __u64   version;
1310                 int     cpt;
1311                 int     cpt2;
1312
1313                 cpt = lnet_net_lock_current();
1314 rescan:
1315                 version = the_lnet.ln_routers_version;
1316
1317                 list_for_each(entry, &the_lnet.ln_routers) {
1318                         rtr = list_entry(entry, struct lnet_peer_ni,
1319                                          lpni_rtr_list);
1320
1321                         cpt2 = rtr->lpni_cpt;
1322                         if (cpt != cpt2) {
1323                                 lnet_net_unlock(cpt);
1324                                 cpt = cpt2;
1325                                 lnet_net_lock(cpt);
1326                                 /* the routers list has changed */
1327                                 if (version != the_lnet.ln_routers_version)
1328                                         goto rescan;
1329                         }
1330
1331                         lnet_ping_router_locked(rtr);
1332
1333                         /* NB dropped lock */
1334                         if (version != the_lnet.ln_routers_version) {
1335                                 /* the routers list has changed */
1336                                 goto rescan;
1337                         }
1338                 }
1339
1340                 if (the_lnet.ln_routing)
1341                         lnet_update_ni_status_locked();
1342
1343                 lnet_net_unlock(cpt);
1344
1345                 lnet_prune_rc_data(0); /* don't wait for UNLINK */
1346
1347                 /* Call schedule_timeout() here always adds 1 to load average
1348                  * because kernel counts # active tasks as nr_running
1349                  * + nr_uninterruptible. */
1350                 /* if there are any routes then wakeup every second.  If
1351                  * there are no routes then sleep indefinitely until woken
1352                  * up by a user adding a route */
1353                 if (!lnet_router_checker_active())
1354                         wait_event_interruptible(the_lnet.ln_rc_waitq,
1355                                                  lnet_router_checker_active());
1356                 else
1357                         wait_event_interruptible_timeout(the_lnet.ln_rc_waitq,
1358                                                          false,
1359                                                          cfs_time_seconds(1));
1360         }
1361
1362         lnet_prune_rc_data(1); /* wait for UNLINK */
1363
1364         the_lnet.ln_rc_state = LNET_RC_STATE_SHUTDOWN;
1365         up(&the_lnet.ln_rc_signal);
1366         /* The unlink event callback will signal final completion */
1367         return 0;
1368 }
1369
1370 void
1371 lnet_destroy_rtrbuf(struct lnet_rtrbuf *rb, int npages)
1372 {
1373         int sz = offsetof(struct lnet_rtrbuf, rb_kiov[npages]);
1374
1375         while (--npages >= 0)
1376                 __free_page(rb->rb_kiov[npages].kiov_page);
1377
1378         LIBCFS_FREE(rb, sz);
1379 }
1380
1381 static struct lnet_rtrbuf *
1382 lnet_new_rtrbuf(struct lnet_rtrbufpool *rbp, int cpt)
1383 {
1384         int            npages = rbp->rbp_npages;
1385         int            sz = offsetof(struct lnet_rtrbuf, rb_kiov[npages]);
1386         struct page   *page;
1387         struct lnet_rtrbuf *rb;
1388         int            i;
1389
1390         LIBCFS_CPT_ALLOC(rb, lnet_cpt_table(), cpt, sz);
1391         if (rb == NULL)
1392                 return NULL;
1393
1394         rb->rb_pool = rbp;
1395
1396         for (i = 0; i < npages; i++) {
1397                 page = cfs_page_cpt_alloc(lnet_cpt_table(), cpt,
1398                                           GFP_KERNEL | __GFP_ZERO);
1399                 if (page == NULL) {
1400                         while (--i >= 0)
1401                                 __free_page(rb->rb_kiov[i].kiov_page);
1402
1403                         LIBCFS_FREE(rb, sz);
1404                         return NULL;
1405                 }
1406
1407                 rb->rb_kiov[i].kiov_len = PAGE_SIZE;
1408                 rb->rb_kiov[i].kiov_offset = 0;
1409                 rb->rb_kiov[i].kiov_page = page;
1410         }
1411
1412         return rb;
1413 }
1414
1415 static void
1416 lnet_rtrpool_free_bufs(struct lnet_rtrbufpool *rbp, int cpt)
1417 {
1418         int npages = rbp->rbp_npages;
1419         struct lnet_rtrbuf *rb;
1420         struct list_head tmp;
1421
1422         if (rbp->rbp_nbuffers == 0) /* not initialized or already freed */
1423                 return;
1424
1425         INIT_LIST_HEAD(&tmp);
1426
1427         lnet_net_lock(cpt);
1428         list_splice_init(&rbp->rbp_msgs, &tmp);
1429         lnet_drop_routed_msgs_locked(&tmp, cpt);
1430         list_splice_init(&rbp->rbp_bufs, &tmp);
1431         rbp->rbp_req_nbuffers = 0;
1432         rbp->rbp_nbuffers = rbp->rbp_credits = 0;
1433         rbp->rbp_mincredits = 0;
1434         lnet_net_unlock(cpt);
1435
1436         /* Free buffers on the free list. */
1437         while (!list_empty(&tmp)) {
1438                 rb = list_entry(tmp.next, struct lnet_rtrbuf, rb_list);
1439                 list_del(&rb->rb_list);
1440                 lnet_destroy_rtrbuf(rb, npages);
1441         }
1442 }
1443
1444 static int
1445 lnet_rtrpool_adjust_bufs(struct lnet_rtrbufpool *rbp, int nbufs, int cpt)
1446 {
1447         struct list_head rb_list;
1448         struct lnet_rtrbuf *rb;
1449         int             num_rb;
1450         int             num_buffers = 0;
1451         int             old_req_nbufs;
1452         int             npages = rbp->rbp_npages;
1453
1454         lnet_net_lock(cpt);
1455         /* If we are called for less buffers than already in the pool, we
1456          * just lower the req_nbuffers number and excess buffers will be
1457          * thrown away as they are returned to the free list.  Credits
1458          * then get adjusted as well.
1459          * If we already have enough buffers allocated to serve the
1460          * increase requested, then we can treat that the same way as we
1461          * do the decrease. */
1462         num_rb = nbufs - rbp->rbp_nbuffers;
1463         if (nbufs <= rbp->rbp_req_nbuffers || num_rb <= 0) {
1464                 rbp->rbp_req_nbuffers = nbufs;
1465                 lnet_net_unlock(cpt);
1466                 return 0;
1467         }
1468         /* store the older value of rbp_req_nbuffers and then set it to
1469          * the new request to prevent lnet_return_rx_credits_locked() from
1470          * freeing buffers that we need to keep around */
1471         old_req_nbufs = rbp->rbp_req_nbuffers;
1472         rbp->rbp_req_nbuffers = nbufs;
1473         lnet_net_unlock(cpt);
1474
1475         INIT_LIST_HEAD(&rb_list);
1476
1477         /* allocate the buffers on a local list first.  If all buffers are
1478          * allocated successfully then join this list to the rbp buffer
1479          * list.  If not then free all allocated buffers. */
1480         while (num_rb-- > 0) {
1481                 rb = lnet_new_rtrbuf(rbp, cpt);
1482                 if (rb == NULL) {
1483                         CERROR("Failed to allocate %d route bufs of %d pages\n",
1484                                nbufs, npages);
1485
1486                         lnet_net_lock(cpt);
1487                         rbp->rbp_req_nbuffers = old_req_nbufs;
1488                         lnet_net_unlock(cpt);
1489
1490                         goto failed;
1491                 }
1492
1493                 list_add(&rb->rb_list, &rb_list);
1494                 num_buffers++;
1495         }
1496
1497         lnet_net_lock(cpt);
1498
1499         list_splice_tail(&rb_list, &rbp->rbp_bufs);
1500         rbp->rbp_nbuffers += num_buffers;
1501         rbp->rbp_credits += num_buffers;
1502         rbp->rbp_mincredits = rbp->rbp_credits;
1503         /* We need to schedule blocked msg using the newly
1504          * added buffers. */
1505         while (!list_empty(&rbp->rbp_bufs) &&
1506                !list_empty(&rbp->rbp_msgs))
1507                 lnet_schedule_blocked_locked(rbp);
1508
1509         lnet_net_unlock(cpt);
1510
1511         return 0;
1512
1513 failed:
1514         while (!list_empty(&rb_list)) {
1515                 rb = list_entry(rb_list.next, struct lnet_rtrbuf, rb_list);
1516                 list_del(&rb->rb_list);
1517                 lnet_destroy_rtrbuf(rb, npages);
1518         }
1519
1520         return -ENOMEM;
1521 }
1522
1523 static void
1524 lnet_rtrpool_init(struct lnet_rtrbufpool *rbp, int npages)
1525 {
1526         INIT_LIST_HEAD(&rbp->rbp_msgs);
1527         INIT_LIST_HEAD(&rbp->rbp_bufs);
1528
1529         rbp->rbp_npages = npages;
1530         rbp->rbp_credits = 0;
1531         rbp->rbp_mincredits = 0;
1532 }
1533
1534 void
1535 lnet_rtrpools_free(int keep_pools)
1536 {
1537         struct lnet_rtrbufpool *rtrp;
1538         int               i;
1539
1540         if (the_lnet.ln_rtrpools == NULL) /* uninitialized or freed */
1541                 return;
1542
1543         cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
1544                 lnet_rtrpool_free_bufs(&rtrp[LNET_TINY_BUF_IDX], i);
1545                 lnet_rtrpool_free_bufs(&rtrp[LNET_SMALL_BUF_IDX], i);
1546                 lnet_rtrpool_free_bufs(&rtrp[LNET_LARGE_BUF_IDX], i);
1547         }
1548
1549         if (!keep_pools) {
1550                 cfs_percpt_free(the_lnet.ln_rtrpools);
1551                 the_lnet.ln_rtrpools = NULL;
1552         }
1553 }
1554
1555 static int
1556 lnet_nrb_tiny_calculate(void)
1557 {
1558         int     nrbs = LNET_NRB_TINY;
1559
1560         if (tiny_router_buffers < 0) {
1561                 LCONSOLE_ERROR_MSG(0x10c,
1562                                    "tiny_router_buffers=%d invalid when "
1563                                    "routing enabled\n", tiny_router_buffers);
1564                 return -EINVAL;
1565         }
1566
1567         if (tiny_router_buffers > 0)
1568                 nrbs = tiny_router_buffers;
1569
1570         nrbs /= LNET_CPT_NUMBER;
1571         return max(nrbs, LNET_NRB_TINY_MIN);
1572 }
1573
1574 static int
1575 lnet_nrb_small_calculate(void)
1576 {
1577         int     nrbs = LNET_NRB_SMALL;
1578
1579         if (small_router_buffers < 0) {
1580                 LCONSOLE_ERROR_MSG(0x10c,
1581                                    "small_router_buffers=%d invalid when "
1582                                    "routing enabled\n", small_router_buffers);
1583                 return -EINVAL;
1584         }
1585
1586         if (small_router_buffers > 0)
1587                 nrbs = small_router_buffers;
1588
1589         nrbs /= LNET_CPT_NUMBER;
1590         return max(nrbs, LNET_NRB_SMALL_MIN);
1591 }
1592
1593 static int
1594 lnet_nrb_large_calculate(void)
1595 {
1596         int     nrbs = LNET_NRB_LARGE;
1597
1598         if (large_router_buffers < 0) {
1599                 LCONSOLE_ERROR_MSG(0x10c,
1600                                    "large_router_buffers=%d invalid when "
1601                                    "routing enabled\n", large_router_buffers);
1602                 return -EINVAL;
1603         }
1604
1605         if (large_router_buffers > 0)
1606                 nrbs = large_router_buffers;
1607
1608         nrbs /= LNET_CPT_NUMBER;
1609         return max(nrbs, LNET_NRB_LARGE_MIN);
1610 }
1611
1612 int
1613 lnet_rtrpools_alloc(int im_a_router)
1614 {
1615         struct lnet_rtrbufpool *rtrp;
1616         int     nrb_tiny;
1617         int     nrb_small;
1618         int     nrb_large;
1619         int     rc;
1620         int     i;
1621
1622         if (!strcmp(forwarding, "")) {
1623                 /* not set either way */
1624                 if (!im_a_router)
1625                         return 0;
1626         } else if (!strcmp(forwarding, "disabled")) {
1627                 /* explicitly disabled */
1628                 return 0;
1629         } else if (!strcmp(forwarding, "enabled")) {
1630                 /* explicitly enabled */
1631         } else {
1632                 LCONSOLE_ERROR_MSG(0x10b, "'forwarding' not set to either "
1633                                    "'enabled' or 'disabled'\n");
1634                 return -EINVAL;
1635         }
1636
1637         nrb_tiny = lnet_nrb_tiny_calculate();
1638         if (nrb_tiny < 0)
1639                 return -EINVAL;
1640
1641         nrb_small = lnet_nrb_small_calculate();
1642         if (nrb_small < 0)
1643                 return -EINVAL;
1644
1645         nrb_large = lnet_nrb_large_calculate();
1646         if (nrb_large < 0)
1647                 return -EINVAL;
1648
1649         the_lnet.ln_rtrpools = cfs_percpt_alloc(lnet_cpt_table(),
1650                                                 LNET_NRBPOOLS *
1651                                                 sizeof(struct lnet_rtrbufpool));
1652         if (the_lnet.ln_rtrpools == NULL) {
1653                 LCONSOLE_ERROR_MSG(0x10c,
1654                                    "Failed to initialize router buffe pool\n");
1655                 return -ENOMEM;
1656         }
1657
1658         cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
1659                 lnet_rtrpool_init(&rtrp[LNET_TINY_BUF_IDX], 0);
1660                 rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_TINY_BUF_IDX],
1661                                               nrb_tiny, i);
1662                 if (rc != 0)
1663                         goto failed;
1664
1665                 lnet_rtrpool_init(&rtrp[LNET_SMALL_BUF_IDX],
1666                                   LNET_NRB_SMALL_PAGES);
1667                 rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_SMALL_BUF_IDX],
1668                                               nrb_small, i);
1669                 if (rc != 0)
1670                         goto failed;
1671
1672                 lnet_rtrpool_init(&rtrp[LNET_LARGE_BUF_IDX],
1673                                   LNET_NRB_LARGE_PAGES);
1674                 rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_LARGE_BUF_IDX],
1675                                               nrb_large, i);
1676                 if (rc != 0)
1677                         goto failed;
1678         }
1679
1680         lnet_net_lock(LNET_LOCK_EX);
1681         the_lnet.ln_routing = 1;
1682         lnet_net_unlock(LNET_LOCK_EX);
1683         return 0;
1684
1685  failed:
1686         lnet_rtrpools_free(0);
1687         return rc;
1688 }
1689
1690 static int
1691 lnet_rtrpools_adjust_helper(int tiny, int small, int large)
1692 {
1693         int nrb = 0;
1694         int rc = 0;
1695         int i;
1696         struct lnet_rtrbufpool *rtrp;
1697
1698         /* If the provided values for each buffer pool are different than the
1699          * configured values, we need to take action. */
1700         if (tiny >= 0) {
1701                 tiny_router_buffers = tiny;
1702                 nrb = lnet_nrb_tiny_calculate();
1703                 cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
1704                         rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_TINY_BUF_IDX],
1705                                                       nrb, i);
1706                         if (rc != 0)
1707                                 return rc;
1708                 }
1709         }
1710         if (small >= 0) {
1711                 small_router_buffers = small;
1712                 nrb = lnet_nrb_small_calculate();
1713                 cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
1714                         rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_SMALL_BUF_IDX],
1715                                                       nrb, i);
1716                         if (rc != 0)
1717                                 return rc;
1718                 }
1719         }
1720         if (large >= 0) {
1721                 large_router_buffers = large;
1722                 nrb = lnet_nrb_large_calculate();
1723                 cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
1724                         rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_LARGE_BUF_IDX],
1725                                                       nrb, i);
1726                         if (rc != 0)
1727                                 return rc;
1728                 }
1729         }
1730
1731         return 0;
1732 }
1733
1734 int
1735 lnet_rtrpools_adjust(int tiny, int small, int large)
1736 {
1737         /* this function doesn't revert the changes if adding new buffers
1738          * failed.  It's up to the user space caller to revert the
1739          * changes. */
1740
1741         if (!the_lnet.ln_routing)
1742                 return 0;
1743
1744         return lnet_rtrpools_adjust_helper(tiny, small, large);
1745 }
1746
1747 int
1748 lnet_rtrpools_enable(void)
1749 {
1750         int rc = 0;
1751
1752         if (the_lnet.ln_routing)
1753                 return 0;
1754
1755         if (the_lnet.ln_rtrpools == NULL)
1756                 /* If routing is turned off, and we have never
1757                  * initialized the pools before, just call the
1758                  * standard buffer pool allocation routine as
1759                  * if we are just configuring this for the first
1760                  * time. */
1761                 rc = lnet_rtrpools_alloc(1);
1762         else
1763                 rc = lnet_rtrpools_adjust_helper(0, 0, 0);
1764         if (rc != 0)
1765                 return rc;
1766
1767         lnet_net_lock(LNET_LOCK_EX);
1768         the_lnet.ln_routing = 1;
1769
1770         the_lnet.ln_ping_target->pb_info.pi_features &=
1771                 ~LNET_PING_FEAT_RTE_DISABLED;
1772         lnet_net_unlock(LNET_LOCK_EX);
1773
1774         return rc;
1775 }
1776
1777 void
1778 lnet_rtrpools_disable(void)
1779 {
1780         if (!the_lnet.ln_routing)
1781                 return;
1782
1783         lnet_net_lock(LNET_LOCK_EX);
1784         the_lnet.ln_routing = 0;
1785         the_lnet.ln_ping_target->pb_info.pi_features |=
1786                 LNET_PING_FEAT_RTE_DISABLED;
1787
1788         tiny_router_buffers = 0;
1789         small_router_buffers = 0;
1790         large_router_buffers = 0;
1791         lnet_net_unlock(LNET_LOCK_EX);
1792         lnet_rtrpools_free(1);
1793 }
1794
1795 int
1796 lnet_notify(struct lnet_ni *ni, lnet_nid_t nid, int alive, time64_t when)
1797 {
1798         struct lnet_peer_ni *lp = NULL;
1799         time64_t now = ktime_get_seconds();
1800         int cpt = lnet_cpt_of_nid(nid, ni);
1801
1802         LASSERT (!in_interrupt ());
1803
1804         CDEBUG (D_NET, "%s notifying %s: %s\n",
1805                 (ni == NULL) ? "userspace" : libcfs_nid2str(ni->ni_nid),
1806                 libcfs_nid2str(nid),
1807                 alive ? "up" : "down");
1808
1809         if (ni != NULL &&
1810             LNET_NIDNET(ni->ni_nid) != LNET_NIDNET(nid)) {
1811                 CWARN("Ignoring notification of %s %s by %s (different net)\n",
1812                       libcfs_nid2str(nid), alive ? "birth" : "death",
1813                       libcfs_nid2str(ni->ni_nid));
1814                 return -EINVAL;
1815         }
1816
1817         /* can't do predictions... */
1818         if (when > now) {
1819                 CWARN("Ignoring prediction from %s of %s %s "
1820                       "%lld seconds in the future\n",
1821                       (ni == NULL) ? "userspace" : libcfs_nid2str(ni->ni_nid),
1822                       libcfs_nid2str(nid), alive ? "up" : "down", when - now);
1823                 return -EINVAL;
1824         }
1825
1826         if (ni != NULL && !alive &&             /* LND telling me she's down */
1827             !auto_down) {                       /* auto-down disabled */
1828                 CDEBUG(D_NET, "Auto-down disabled\n");
1829                 return 0;
1830         }
1831
1832         lnet_net_lock(cpt);
1833
1834         if (the_lnet.ln_state != LNET_STATE_RUNNING) {
1835                 lnet_net_unlock(cpt);
1836                 return -ESHUTDOWN;
1837         }
1838
1839         lp = lnet_find_peer_ni_locked(nid);
1840         if (lp == NULL) {
1841                 /* nid not found */
1842                 lnet_net_unlock(cpt);
1843                 CDEBUG(D_NET, "%s not found\n", libcfs_nid2str(nid));
1844                 return 0;
1845         }
1846
1847         /*
1848          * It is possible for this function to be called for the same peer
1849          * but with different NIs. We want to synchronize the notification
1850          * between the different calls. So we will use the lpni_cpt to
1851          * grab the net lock.
1852          */
1853         if (lp->lpni_cpt != cpt) {
1854                 lnet_net_unlock(cpt);
1855                 cpt = lp->lpni_cpt;
1856                 lnet_net_lock(cpt);
1857         }
1858
1859         /* We can't fully trust LND on reporting exact peer last_alive
1860          * if he notifies us about dead peer. For example ksocklnd can
1861          * call us with when == _time_when_the_node_was_booted_ if
1862          * no connections were successfully established */
1863         if (ni != NULL && !alive && when < lp->lpni_last_alive)
1864                 when = lp->lpni_last_alive;
1865
1866         lnet_notify_locked(lp, ni == NULL, alive, when);
1867
1868         if (ni != NULL)
1869                 lnet_ni_notify_locked(ni, lp);
1870
1871         lnet_peer_ni_decref_locked(lp);
1872
1873         lnet_net_unlock(cpt);
1874         return 0;
1875 }
1876 EXPORT_SYMBOL(lnet_notify);