Whamcloud - gitweb
7a3e68e36715bd84dd922d215f80fa4e43d2c776
[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                    cfs_time_t when)
103 {
104         if (cfs_time_before(when, lp->lpni_timestamp)) { /* 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 == 0), cfs_time_current());
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         int 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:%d) 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         cfs_time_t      now = cfs_time_current();
1055         int             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             cfs_time_after(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 %d: deadline %lu ping_notsent %d alive %d "
1085                "alive_count %d lpni_ping_timestamp %lu\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             cfs_time_after(now, cfs_time_add(rtr->lpni_ping_timestamp,
1092                                              cfs_time_seconds(secs)))) {
1093                 int               rc;
1094                 struct lnet_process_id id;
1095                 struct lnet_handle_md mdh;
1096
1097                 id.nid = rtr->lpni_nid;
1098                 id.pid = LNET_PID_LUSTRE;
1099                 CDEBUG(D_NET, "Check: %s\n", libcfs_id2str(id));
1100
1101                 rtr->lpni_ping_notsent   = 1;
1102                 rtr->lpni_ping_timestamp = now;
1103
1104                 mdh = rcd->rcd_mdh;
1105
1106                 if (rtr->lpni_ping_deadline == 0) {
1107                         rtr->lpni_ping_deadline =
1108                                 cfs_time_shift(router_ping_timeout);
1109                 }
1110
1111                 lnet_net_unlock(rtr->lpni_cpt);
1112
1113                 rc = LNetGet(LNET_NID_ANY, mdh, id, LNET_RESERVED_PORTAL,
1114                              LNET_PROTO_PING_MATCHBITS, 0);
1115
1116                 lnet_net_lock(rtr->lpni_cpt);
1117                 if (rc != 0)
1118                         rtr->lpni_ping_notsent = 0; /* no event pending */
1119         }
1120
1121         lnet_peer_ni_decref_locked(rtr);
1122         return;
1123 }
1124
1125 int
1126 lnet_router_checker_start(void)
1127 {
1128         int                     rc;
1129         int                     eqsz = 0;
1130         struct task_struct     *task;
1131
1132         LASSERT(the_lnet.ln_rc_state == LNET_RC_STATE_SHUTDOWN);
1133
1134         if (check_routers_before_use &&
1135             dead_router_check_interval <= 0) {
1136                 LCONSOLE_ERROR_MSG(0x10a, "'dead_router_check_interval' must be"
1137                                    " set if 'check_routers_before_use' is set"
1138                                    "\n");
1139                 return -EINVAL;
1140         }
1141
1142         sema_init(&the_lnet.ln_rc_signal, 0);
1143
1144         rc = LNetEQAlloc(0, lnet_router_checker_event, &the_lnet.ln_rc_eqh);
1145         if (rc != 0) {
1146                 CERROR("Can't allocate EQ(%d): %d\n", eqsz, rc);
1147                 return -ENOMEM;
1148         }
1149
1150         the_lnet.ln_rc_state = LNET_RC_STATE_RUNNING;
1151         task = kthread_run(lnet_router_checker, NULL, "router_checker");
1152         if (IS_ERR(task)) {
1153                 rc = PTR_ERR(task);
1154                 CERROR("Can't start router checker thread: %d\n", rc);
1155                 /* block until event callback signals exit */
1156                 down(&the_lnet.ln_rc_signal);
1157                 rc = LNetEQFree(the_lnet.ln_rc_eqh);
1158                 LASSERT(rc == 0);
1159                 the_lnet.ln_rc_state = LNET_RC_STATE_SHUTDOWN;
1160                 return -ENOMEM;
1161         }
1162
1163         if (check_routers_before_use) {
1164                 /* Note that a helpful side-effect of pinging all known routers
1165                  * at startup is that it makes them drop stale connections they
1166                  * may have to a previous instance of me. */
1167                 lnet_wait_known_routerstate();
1168         }
1169
1170         return 0;
1171 }
1172
1173 void
1174 lnet_router_checker_stop (void)
1175 {
1176         int rc;
1177
1178         if (the_lnet.ln_rc_state == LNET_RC_STATE_SHUTDOWN)
1179                 return;
1180
1181         LASSERT (the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING);
1182         the_lnet.ln_rc_state = LNET_RC_STATE_STOPPING;
1183         /* wakeup the RC thread if it's sleeping */
1184         wake_up(&the_lnet.ln_rc_waitq);
1185
1186         /* block until event callback signals exit */
1187         down(&the_lnet.ln_rc_signal);
1188         LASSERT(the_lnet.ln_rc_state == LNET_RC_STATE_SHUTDOWN);
1189
1190         rc = LNetEQFree(the_lnet.ln_rc_eqh);
1191         LASSERT(rc == 0);
1192         return;
1193 }
1194
1195 static void
1196 lnet_prune_rc_data(int wait_unlink)
1197 {
1198         struct lnet_rc_data *rcd;
1199         struct lnet_rc_data *tmp;
1200         struct lnet_peer_ni *lp;
1201         struct list_head head;
1202         int i = 2;
1203
1204         if (likely(the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING &&
1205                    list_empty(&the_lnet.ln_rcd_deathrow) &&
1206                    list_empty(&the_lnet.ln_rcd_zombie)))
1207                 return;
1208
1209         INIT_LIST_HEAD(&head);
1210
1211         lnet_net_lock(LNET_LOCK_EX);
1212
1213         if (the_lnet.ln_rc_state != LNET_RC_STATE_RUNNING) {
1214                 /* router checker is stopping, prune all */
1215                 list_for_each_entry(lp, &the_lnet.ln_routers,
1216                                     lpni_rtr_list) {
1217                         if (lp->lpni_rcd == NULL)
1218                                 continue;
1219
1220                         LASSERT(list_empty(&lp->lpni_rcd->rcd_list));
1221                         list_add(&lp->lpni_rcd->rcd_list,
1222                                  &the_lnet.ln_rcd_deathrow);
1223                         lp->lpni_rcd = NULL;
1224                 }
1225         }
1226
1227         /* unlink all RCDs on deathrow list */
1228         list_splice_init(&the_lnet.ln_rcd_deathrow, &head);
1229
1230         if (!list_empty(&head)) {
1231                 lnet_net_unlock(LNET_LOCK_EX);
1232
1233                 list_for_each_entry(rcd, &head, rcd_list)
1234                         LNetMDUnlink(rcd->rcd_mdh);
1235
1236                 lnet_net_lock(LNET_LOCK_EX);
1237         }
1238
1239         list_splice_init(&head, &the_lnet.ln_rcd_zombie);
1240
1241         /* release all zombie RCDs */
1242         while (!list_empty(&the_lnet.ln_rcd_zombie)) {
1243                 list_for_each_entry_safe(rcd, tmp, &the_lnet.ln_rcd_zombie,
1244                                          rcd_list) {
1245                         if (LNetMDHandleIsInvalid(rcd->rcd_mdh))
1246                                 list_move(&rcd->rcd_list, &head);
1247                 }
1248
1249                 wait_unlink = wait_unlink &&
1250                               !list_empty(&the_lnet.ln_rcd_zombie);
1251
1252                 lnet_net_unlock(LNET_LOCK_EX);
1253
1254                 while (!list_empty(&head)) {
1255                         rcd = list_entry(head.next,
1256                                          struct lnet_rc_data, rcd_list);
1257                         list_del_init(&rcd->rcd_list);
1258                         lnet_destroy_rc_data(rcd);
1259                 }
1260
1261                 if (!wait_unlink)
1262                         return;
1263
1264                 i++;
1265                 CDEBUG(((i & (-i)) == i) ? D_WARNING : D_NET,
1266                        "Waiting for rc buffers to unlink\n");
1267                 set_current_state(TASK_UNINTERRUPTIBLE);
1268                 schedule_timeout(cfs_time_seconds(1) / 4);
1269
1270                 lnet_net_lock(LNET_LOCK_EX);
1271         }
1272
1273         lnet_net_unlock(LNET_LOCK_EX);
1274 }
1275
1276 /*
1277  * This function is called to check if the RC should block indefinitely.
1278  * It's called from lnet_router_checker() as well as being passed to
1279  * wait_event_interruptible() to avoid the lost wake_up problem.
1280  *
1281  * When it's called from wait_event_interruptible() it is necessary to
1282  * also not sleep if the rc state is not running to avoid a deadlock
1283  * when the system is shutting down
1284  */
1285 static inline bool
1286 lnet_router_checker_active(void)
1287 {
1288         if (the_lnet.ln_rc_state != LNET_RC_STATE_RUNNING)
1289                 return true;
1290
1291         /* Router Checker thread needs to run when routing is enabled in
1292          * order to call lnet_update_ni_status_locked() */
1293         if (the_lnet.ln_routing)
1294                 return true;
1295
1296         return !list_empty(&the_lnet.ln_routers) &&
1297                 (live_router_check_interval > 0 ||
1298                  dead_router_check_interval > 0);
1299 }
1300
1301 static int
1302 lnet_router_checker(void *arg)
1303 {
1304         struct lnet_peer_ni *rtr;
1305         struct list_head *entry;
1306
1307         cfs_block_allsigs();
1308
1309         while (the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING) {
1310                 __u64   version;
1311                 int     cpt;
1312                 int     cpt2;
1313
1314                 cpt = lnet_net_lock_current();
1315 rescan:
1316                 version = the_lnet.ln_routers_version;
1317
1318                 list_for_each(entry, &the_lnet.ln_routers) {
1319                         rtr = list_entry(entry, struct lnet_peer_ni,
1320                                          lpni_rtr_list);
1321
1322                         cpt2 = rtr->lpni_cpt;
1323                         if (cpt != cpt2) {
1324                                 lnet_net_unlock(cpt);
1325                                 cpt = cpt2;
1326                                 lnet_net_lock(cpt);
1327                                 /* the routers list has changed */
1328                                 if (version != the_lnet.ln_routers_version)
1329                                         goto rescan;
1330                         }
1331
1332                         lnet_ping_router_locked(rtr);
1333
1334                         /* NB dropped lock */
1335                         if (version != the_lnet.ln_routers_version) {
1336                                 /* the routers list has changed */
1337                                 goto rescan;
1338                         }
1339                 }
1340
1341                 if (the_lnet.ln_routing)
1342                         lnet_update_ni_status_locked();
1343
1344                 lnet_net_unlock(cpt);
1345
1346                 lnet_prune_rc_data(0); /* don't wait for UNLINK */
1347
1348                 /* Call schedule_timeout() here always adds 1 to load average
1349                  * because kernel counts # active tasks as nr_running
1350                  * + nr_uninterruptible. */
1351                 /* if there are any routes then wakeup every second.  If
1352                  * there are no routes then sleep indefinitely until woken
1353                  * up by a user adding a route */
1354                 if (!lnet_router_checker_active())
1355                         wait_event_interruptible(the_lnet.ln_rc_waitq,
1356                                                  lnet_router_checker_active());
1357                 else
1358                         wait_event_interruptible_timeout(the_lnet.ln_rc_waitq,
1359                                                          false,
1360                                                          cfs_time_seconds(1));
1361         }
1362
1363         lnet_prune_rc_data(1); /* wait for UNLINK */
1364
1365         the_lnet.ln_rc_state = LNET_RC_STATE_SHUTDOWN;
1366         up(&the_lnet.ln_rc_signal);
1367         /* The unlink event callback will signal final completion */
1368         return 0;
1369 }
1370
1371 void
1372 lnet_destroy_rtrbuf(struct lnet_rtrbuf *rb, int npages)
1373 {
1374         int sz = offsetof(struct lnet_rtrbuf, rb_kiov[npages]);
1375
1376         while (--npages >= 0)
1377                 __free_page(rb->rb_kiov[npages].kiov_page);
1378
1379         LIBCFS_FREE(rb, sz);
1380 }
1381
1382 static struct lnet_rtrbuf *
1383 lnet_new_rtrbuf(struct lnet_rtrbufpool *rbp, int cpt)
1384 {
1385         int            npages = rbp->rbp_npages;
1386         int            sz = offsetof(struct lnet_rtrbuf, rb_kiov[npages]);
1387         struct page   *page;
1388         struct lnet_rtrbuf *rb;
1389         int            i;
1390
1391         LIBCFS_CPT_ALLOC(rb, lnet_cpt_table(), cpt, sz);
1392         if (rb == NULL)
1393                 return NULL;
1394
1395         rb->rb_pool = rbp;
1396
1397         for (i = 0; i < npages; i++) {
1398                 page = cfs_page_cpt_alloc(lnet_cpt_table(), cpt,
1399                                           GFP_KERNEL | __GFP_ZERO);
1400                 if (page == NULL) {
1401                         while (--i >= 0)
1402                                 __free_page(rb->rb_kiov[i].kiov_page);
1403
1404                         LIBCFS_FREE(rb, sz);
1405                         return NULL;
1406                 }
1407
1408                 rb->rb_kiov[i].kiov_len = PAGE_SIZE;
1409                 rb->rb_kiov[i].kiov_offset = 0;
1410                 rb->rb_kiov[i].kiov_page = page;
1411         }
1412
1413         return rb;
1414 }
1415
1416 static void
1417 lnet_rtrpool_free_bufs(struct lnet_rtrbufpool *rbp, int cpt)
1418 {
1419         int npages = rbp->rbp_npages;
1420         struct lnet_rtrbuf *rb;
1421         struct list_head tmp;
1422
1423         if (rbp->rbp_nbuffers == 0) /* not initialized or already freed */
1424                 return;
1425
1426         INIT_LIST_HEAD(&tmp);
1427
1428         lnet_net_lock(cpt);
1429         list_splice_init(&rbp->rbp_msgs, &tmp);
1430         lnet_drop_routed_msgs_locked(&tmp, cpt);
1431         list_splice_init(&rbp->rbp_bufs, &tmp);
1432         rbp->rbp_req_nbuffers = 0;
1433         rbp->rbp_nbuffers = rbp->rbp_credits = 0;
1434         rbp->rbp_mincredits = 0;
1435         lnet_net_unlock(cpt);
1436
1437         /* Free buffers on the free list. */
1438         while (!list_empty(&tmp)) {
1439                 rb = list_entry(tmp.next, struct lnet_rtrbuf, rb_list);
1440                 list_del(&rb->rb_list);
1441                 lnet_destroy_rtrbuf(rb, npages);
1442         }
1443 }
1444
1445 static int
1446 lnet_rtrpool_adjust_bufs(struct lnet_rtrbufpool *rbp, int nbufs, int cpt)
1447 {
1448         struct list_head rb_list;
1449         struct lnet_rtrbuf *rb;
1450         int             num_rb;
1451         int             num_buffers = 0;
1452         int             old_req_nbufs;
1453         int             npages = rbp->rbp_npages;
1454
1455         lnet_net_lock(cpt);
1456         /* If we are called for less buffers than already in the pool, we
1457          * just lower the req_nbuffers number and excess buffers will be
1458          * thrown away as they are returned to the free list.  Credits
1459          * then get adjusted as well.
1460          * If we already have enough buffers allocated to serve the
1461          * increase requested, then we can treat that the same way as we
1462          * do the decrease. */
1463         num_rb = nbufs - rbp->rbp_nbuffers;
1464         if (nbufs <= rbp->rbp_req_nbuffers || num_rb <= 0) {
1465                 rbp->rbp_req_nbuffers = nbufs;
1466                 lnet_net_unlock(cpt);
1467                 return 0;
1468         }
1469         /* store the older value of rbp_req_nbuffers and then set it to
1470          * the new request to prevent lnet_return_rx_credits_locked() from
1471          * freeing buffers that we need to keep around */
1472         old_req_nbufs = rbp->rbp_req_nbuffers;
1473         rbp->rbp_req_nbuffers = nbufs;
1474         lnet_net_unlock(cpt);
1475
1476         INIT_LIST_HEAD(&rb_list);
1477
1478         /* allocate the buffers on a local list first.  If all buffers are
1479          * allocated successfully then join this list to the rbp buffer
1480          * list.  If not then free all allocated buffers. */
1481         while (num_rb-- > 0) {
1482                 rb = lnet_new_rtrbuf(rbp, cpt);
1483                 if (rb == NULL) {
1484                         CERROR("Failed to allocate %d route bufs of %d pages\n",
1485                                nbufs, npages);
1486
1487                         lnet_net_lock(cpt);
1488                         rbp->rbp_req_nbuffers = old_req_nbufs;
1489                         lnet_net_unlock(cpt);
1490
1491                         goto failed;
1492                 }
1493
1494                 list_add(&rb->rb_list, &rb_list);
1495                 num_buffers++;
1496         }
1497
1498         lnet_net_lock(cpt);
1499
1500         list_splice_tail(&rb_list, &rbp->rbp_bufs);
1501         rbp->rbp_nbuffers += num_buffers;
1502         rbp->rbp_credits += num_buffers;
1503         rbp->rbp_mincredits = rbp->rbp_credits;
1504         /* We need to schedule blocked msg using the newly
1505          * added buffers. */
1506         while (!list_empty(&rbp->rbp_bufs) &&
1507                !list_empty(&rbp->rbp_msgs))
1508                 lnet_schedule_blocked_locked(rbp);
1509
1510         lnet_net_unlock(cpt);
1511
1512         return 0;
1513
1514 failed:
1515         while (!list_empty(&rb_list)) {
1516                 rb = list_entry(rb_list.next, struct lnet_rtrbuf, rb_list);
1517                 list_del(&rb->rb_list);
1518                 lnet_destroy_rtrbuf(rb, npages);
1519         }
1520
1521         return -ENOMEM;
1522 }
1523
1524 static void
1525 lnet_rtrpool_init(struct lnet_rtrbufpool *rbp, int npages)
1526 {
1527         INIT_LIST_HEAD(&rbp->rbp_msgs);
1528         INIT_LIST_HEAD(&rbp->rbp_bufs);
1529
1530         rbp->rbp_npages = npages;
1531         rbp->rbp_credits = 0;
1532         rbp->rbp_mincredits = 0;
1533 }
1534
1535 void
1536 lnet_rtrpools_free(int keep_pools)
1537 {
1538         struct lnet_rtrbufpool *rtrp;
1539         int               i;
1540
1541         if (the_lnet.ln_rtrpools == NULL) /* uninitialized or freed */
1542                 return;
1543
1544         cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
1545                 lnet_rtrpool_free_bufs(&rtrp[LNET_TINY_BUF_IDX], i);
1546                 lnet_rtrpool_free_bufs(&rtrp[LNET_SMALL_BUF_IDX], i);
1547                 lnet_rtrpool_free_bufs(&rtrp[LNET_LARGE_BUF_IDX], i);
1548         }
1549
1550         if (!keep_pools) {
1551                 cfs_percpt_free(the_lnet.ln_rtrpools);
1552                 the_lnet.ln_rtrpools = NULL;
1553         }
1554 }
1555
1556 static int
1557 lnet_nrb_tiny_calculate(void)
1558 {
1559         int     nrbs = LNET_NRB_TINY;
1560
1561         if (tiny_router_buffers < 0) {
1562                 LCONSOLE_ERROR_MSG(0x10c,
1563                                    "tiny_router_buffers=%d invalid when "
1564                                    "routing enabled\n", tiny_router_buffers);
1565                 return -EINVAL;
1566         }
1567
1568         if (tiny_router_buffers > 0)
1569                 nrbs = tiny_router_buffers;
1570
1571         nrbs /= LNET_CPT_NUMBER;
1572         return max(nrbs, LNET_NRB_TINY_MIN);
1573 }
1574
1575 static int
1576 lnet_nrb_small_calculate(void)
1577 {
1578         int     nrbs = LNET_NRB_SMALL;
1579
1580         if (small_router_buffers < 0) {
1581                 LCONSOLE_ERROR_MSG(0x10c,
1582                                    "small_router_buffers=%d invalid when "
1583                                    "routing enabled\n", small_router_buffers);
1584                 return -EINVAL;
1585         }
1586
1587         if (small_router_buffers > 0)
1588                 nrbs = small_router_buffers;
1589
1590         nrbs /= LNET_CPT_NUMBER;
1591         return max(nrbs, LNET_NRB_SMALL_MIN);
1592 }
1593
1594 static int
1595 lnet_nrb_large_calculate(void)
1596 {
1597         int     nrbs = LNET_NRB_LARGE;
1598
1599         if (large_router_buffers < 0) {
1600                 LCONSOLE_ERROR_MSG(0x10c,
1601                                    "large_router_buffers=%d invalid when "
1602                                    "routing enabled\n", large_router_buffers);
1603                 return -EINVAL;
1604         }
1605
1606         if (large_router_buffers > 0)
1607                 nrbs = large_router_buffers;
1608
1609         nrbs /= LNET_CPT_NUMBER;
1610         return max(nrbs, LNET_NRB_LARGE_MIN);
1611 }
1612
1613 int
1614 lnet_rtrpools_alloc(int im_a_router)
1615 {
1616         struct lnet_rtrbufpool *rtrp;
1617         int     nrb_tiny;
1618         int     nrb_small;
1619         int     nrb_large;
1620         int     rc;
1621         int     i;
1622
1623         if (!strcmp(forwarding, "")) {
1624                 /* not set either way */
1625                 if (!im_a_router)
1626                         return 0;
1627         } else if (!strcmp(forwarding, "disabled")) {
1628                 /* explicitly disabled */
1629                 return 0;
1630         } else if (!strcmp(forwarding, "enabled")) {
1631                 /* explicitly enabled */
1632         } else {
1633                 LCONSOLE_ERROR_MSG(0x10b, "'forwarding' not set to either "
1634                                    "'enabled' or 'disabled'\n");
1635                 return -EINVAL;
1636         }
1637
1638         nrb_tiny = lnet_nrb_tiny_calculate();
1639         if (nrb_tiny < 0)
1640                 return -EINVAL;
1641
1642         nrb_small = lnet_nrb_small_calculate();
1643         if (nrb_small < 0)
1644                 return -EINVAL;
1645
1646         nrb_large = lnet_nrb_large_calculate();
1647         if (nrb_large < 0)
1648                 return -EINVAL;
1649
1650         the_lnet.ln_rtrpools = cfs_percpt_alloc(lnet_cpt_table(),
1651                                                 LNET_NRBPOOLS *
1652                                                 sizeof(struct lnet_rtrbufpool));
1653         if (the_lnet.ln_rtrpools == NULL) {
1654                 LCONSOLE_ERROR_MSG(0x10c,
1655                                    "Failed to initialize router buffe pool\n");
1656                 return -ENOMEM;
1657         }
1658
1659         cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
1660                 lnet_rtrpool_init(&rtrp[LNET_TINY_BUF_IDX], 0);
1661                 rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_TINY_BUF_IDX],
1662                                               nrb_tiny, i);
1663                 if (rc != 0)
1664                         goto failed;
1665
1666                 lnet_rtrpool_init(&rtrp[LNET_SMALL_BUF_IDX],
1667                                   LNET_NRB_SMALL_PAGES);
1668                 rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_SMALL_BUF_IDX],
1669                                               nrb_small, i);
1670                 if (rc != 0)
1671                         goto failed;
1672
1673                 lnet_rtrpool_init(&rtrp[LNET_LARGE_BUF_IDX],
1674                                   LNET_NRB_LARGE_PAGES);
1675                 rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_LARGE_BUF_IDX],
1676                                               nrb_large, i);
1677                 if (rc != 0)
1678                         goto failed;
1679         }
1680
1681         lnet_net_lock(LNET_LOCK_EX);
1682         the_lnet.ln_routing = 1;
1683         lnet_net_unlock(LNET_LOCK_EX);
1684         return 0;
1685
1686  failed:
1687         lnet_rtrpools_free(0);
1688         return rc;
1689 }
1690
1691 static int
1692 lnet_rtrpools_adjust_helper(int tiny, int small, int large)
1693 {
1694         int nrb = 0;
1695         int rc = 0;
1696         int i;
1697         struct lnet_rtrbufpool *rtrp;
1698
1699         /* If the provided values for each buffer pool are different than the
1700          * configured values, we need to take action. */
1701         if (tiny >= 0) {
1702                 tiny_router_buffers = tiny;
1703                 nrb = lnet_nrb_tiny_calculate();
1704                 cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
1705                         rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_TINY_BUF_IDX],
1706                                                       nrb, i);
1707                         if (rc != 0)
1708                                 return rc;
1709                 }
1710         }
1711         if (small >= 0) {
1712                 small_router_buffers = small;
1713                 nrb = lnet_nrb_small_calculate();
1714                 cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
1715                         rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_SMALL_BUF_IDX],
1716                                                       nrb, i);
1717                         if (rc != 0)
1718                                 return rc;
1719                 }
1720         }
1721         if (large >= 0) {
1722                 large_router_buffers = large;
1723                 nrb = lnet_nrb_large_calculate();
1724                 cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
1725                         rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_LARGE_BUF_IDX],
1726                                                       nrb, i);
1727                         if (rc != 0)
1728                                 return rc;
1729                 }
1730         }
1731
1732         return 0;
1733 }
1734
1735 int
1736 lnet_rtrpools_adjust(int tiny, int small, int large)
1737 {
1738         /* this function doesn't revert the changes if adding new buffers
1739          * failed.  It's up to the user space caller to revert the
1740          * changes. */
1741
1742         if (!the_lnet.ln_routing)
1743                 return 0;
1744
1745         return lnet_rtrpools_adjust_helper(tiny, small, large);
1746 }
1747
1748 int
1749 lnet_rtrpools_enable(void)
1750 {
1751         int rc = 0;
1752
1753         if (the_lnet.ln_routing)
1754                 return 0;
1755
1756         if (the_lnet.ln_rtrpools == NULL)
1757                 /* If routing is turned off, and we have never
1758                  * initialized the pools before, just call the
1759                  * standard buffer pool allocation routine as
1760                  * if we are just configuring this for the first
1761                  * time. */
1762                 rc = lnet_rtrpools_alloc(1);
1763         else
1764                 rc = lnet_rtrpools_adjust_helper(0, 0, 0);
1765         if (rc != 0)
1766                 return rc;
1767
1768         lnet_net_lock(LNET_LOCK_EX);
1769         the_lnet.ln_routing = 1;
1770
1771         the_lnet.ln_ping_target->pb_info.pi_features &=
1772                 ~LNET_PING_FEAT_RTE_DISABLED;
1773         lnet_net_unlock(LNET_LOCK_EX);
1774
1775         return rc;
1776 }
1777
1778 void
1779 lnet_rtrpools_disable(void)
1780 {
1781         if (!the_lnet.ln_routing)
1782                 return;
1783
1784         lnet_net_lock(LNET_LOCK_EX);
1785         the_lnet.ln_routing = 0;
1786         the_lnet.ln_ping_target->pb_info.pi_features |=
1787                 LNET_PING_FEAT_RTE_DISABLED;
1788
1789         tiny_router_buffers = 0;
1790         small_router_buffers = 0;
1791         large_router_buffers = 0;
1792         lnet_net_unlock(LNET_LOCK_EX);
1793         lnet_rtrpools_free(1);
1794 }
1795
1796 int
1797 lnet_notify(struct lnet_ni *ni, lnet_nid_t nid, int alive, cfs_time_t when)
1798 {
1799         struct lnet_peer_ni *lp = NULL;
1800         cfs_time_t now = cfs_time_current();
1801         int cpt = lnet_cpt_of_nid(nid, ni);
1802
1803         LASSERT (!in_interrupt ());
1804
1805         CDEBUG (D_NET, "%s notifying %s: %s\n",
1806                 (ni == NULL) ? "userspace" : libcfs_nid2str(ni->ni_nid),
1807                 libcfs_nid2str(nid),
1808                 alive ? "up" : "down");
1809
1810         if (ni != NULL &&
1811             LNET_NIDNET(ni->ni_nid) != LNET_NIDNET(nid)) {
1812                 CWARN("Ignoring notification of %s %s by %s (different net)\n",
1813                       libcfs_nid2str(nid), alive ? "birth" : "death",
1814                       libcfs_nid2str(ni->ni_nid));
1815                 return -EINVAL;
1816         }
1817
1818         /* can't do predictions... */
1819         if (cfs_time_after(when, now)) {
1820                 CWARN("Ignoring prediction from %s of %s %s "
1821                       "%ld seconds in the future\n",
1822                       (ni == NULL) ? "userspace" : libcfs_nid2str(ni->ni_nid),
1823                       libcfs_nid2str(nid), alive ? "up" : "down",
1824                       cfs_duration_sec(cfs_time_sub(when, now)));
1825                 return -EINVAL;
1826         }
1827
1828         if (ni != NULL && !alive &&             /* LND telling me she's down */
1829             !auto_down) {                       /* auto-down disabled */
1830                 CDEBUG(D_NET, "Auto-down disabled\n");
1831                 return 0;
1832         }
1833
1834         lnet_net_lock(cpt);
1835
1836         if (the_lnet.ln_state != LNET_STATE_RUNNING) {
1837                 lnet_net_unlock(cpt);
1838                 return -ESHUTDOWN;
1839         }
1840
1841         lp = lnet_find_peer_ni_locked(nid);
1842         if (lp == NULL) {
1843                 /* nid not found */
1844                 lnet_net_unlock(cpt);
1845                 CDEBUG(D_NET, "%s not found\n", libcfs_nid2str(nid));
1846                 return 0;
1847         }
1848
1849         /*
1850          * It is possible for this function to be called for the same peer
1851          * but with different NIs. We want to synchronize the notification
1852          * between the different calls. So we will use the lpni_cpt to
1853          * grab the net lock.
1854          */
1855         if (lp->lpni_cpt != cpt) {
1856                 lnet_net_unlock(cpt);
1857                 cpt = lp->lpni_cpt;
1858                 lnet_net_lock(cpt);
1859         }
1860
1861         /* We can't fully trust LND on reporting exact peer last_alive
1862          * if he notifies us about dead peer. For example ksocklnd can
1863          * call us with when == _time_when_the_node_was_booted_ if
1864          * no connections were successfully established */
1865         if (ni != NULL && !alive && when < lp->lpni_last_alive)
1866                 when = lp->lpni_last_alive;
1867
1868         lnet_notify_locked(lp, ni == NULL, alive, when);
1869
1870         if (ni != NULL)
1871                 lnet_ni_notify_locked(ni, lp);
1872
1873         lnet_peer_ni_decref_locked(lp);
1874
1875         lnet_net_unlock(cpt);
1876         return 0;
1877 }
1878 EXPORT_SYMBOL(lnet_notify);