lnet/lnet/router.c

   1 /*
   2  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
   3  *
   4  * Copyright (c) 2011, 2016, 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(lnet_ni_t *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                           list_entry(pos, struct lnet_peer_ni,
 208                                      lpni_rtr_list);
 209
 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 lnet_remotenet_t *
 246 lnet_find_rnet_locked(__u32 net)
 247 {
 248         lnet_remotenet_t *rnet;
 249         struct list_head *tmp;
 250         struct list_head *rn_list;
 251
 252         LASSERT(!the_lnet.ln_shutdown);
 253
 254         rn_list = lnet_net2rnethash(net);
 255         list_for_each(tmp, rn_list) {
 256                 rnet = list_entry(tmp, lnet_remotenet_t, 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         lnet_ni_t *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(lnet_remotenet_t *rnet, lnet_route_t *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         lnet_remotenet_t        *rnet;
 326         lnet_remotenet_t        *rnet2;
 327         lnet_route_t            *route;
 328         lnet_ni_t               *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_locked(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_shutdown);
 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                 lnet_route_t *route2 = list_entry(e, lnet_route_t, lr_list);
 397
 398                 if (route2->lr_gateway == route->lr_gateway) {
 399                         add_route = 0;
 400                         break;
 401                 }
 402
 403                 /* our lookups must be true */
 404                 LASSERT(route2->lr_gateway->lpni_nid != gateway);
 405         }
 406
 407         if (add_route) {
 408                 lnet_peer_ni_addref_locked(route->lr_gateway); /* +1 for notify */
 409                 lnet_add_route_to_rnet(rnet2, route);
 410
 411                 ni = lnet_get_next_ni_locked(route->lr_gateway->lpni_net, NULL);
 412                 lnet_net_unlock(LNET_LOCK_EX);
 413
 414                 /* XXX Assume alive */
 415                 if (ni->ni_net->net_lnd->lnd_notify != NULL)
 416                         (ni->ni_net->net_lnd->lnd_notify)(ni, gateway, 1);
 417
 418                 lnet_net_lock(LNET_LOCK_EX);
 419         }
 420
 421         /* -1 for notify or !add_route */
 422         lnet_peer_ni_decref_locked(route->lr_gateway);
 423         lnet_net_unlock(LNET_LOCK_EX);
 424
 425         rc = 0;
 426
 427         if (!add_route) {
 428                 rc = -EEXIST;
 429                 LIBCFS_FREE(route, sizeof(*route));
 430         }
 431
 432         if (rnet != rnet2)
 433                 LIBCFS_FREE(rnet, sizeof(*rnet));
 434
 435         /* indicate to startup the router checker if configured */
 436         wake_up(&the_lnet.ln_rc_waitq);
 437
 438         return rc;
 439 }
 440
 441 int
 442 lnet_check_routes(void)
 443 {
 444         lnet_remotenet_t *rnet;
 445         lnet_route_t     *route;
 446         lnet_route_t     *route2;
 447         struct list_head *e1;
 448         struct list_head *e2;
 449         int               cpt;
 450         struct list_head *rn_list;
 451         int               i;
 452
 453         cpt = lnet_net_lock_current();
 454
 455         for (i = 0; i < LNET_REMOTE_NETS_HASH_SIZE; i++) {
 456                 rn_list = &the_lnet.ln_remote_nets_hash[i];
 457                 list_for_each(e1, rn_list) {
 458                         rnet = list_entry(e1, lnet_remotenet_t, lrn_list);
 459
 460                         route2 = NULL;
 461                         list_for_each(e2, &rnet->lrn_routes) {
 462                                 lnet_nid_t      nid1;
 463                                 lnet_nid_t      nid2;
 464                                 int             net;
 465
 466                                 route = list_entry(e2, lnet_route_t,
 467                                                    lr_list);
 468
 469                                 if (route2 == NULL) {
 470                                         route2 = route;
 471                                         continue;
 472                                 }
 473
 474                                 if (route->lr_gateway->lpni_net ==
 475                                     route2->lr_gateway->lpni_net)
 476                                         continue;
 477
 478                                 nid1 = route->lr_gateway->lpni_nid;
 479                                 nid2 = route2->lr_gateway->lpni_nid;
 480                                 net = rnet->lrn_net;
 481
 482                                 lnet_net_unlock(cpt);
 483
 484                                 CERROR("Routes to %s via %s and %s not "
 485                                        "supported\n",
 486                                        libcfs_net2str(net),
 487                                        libcfs_nid2str(nid1),
 488                                        libcfs_nid2str(nid2));
 489                                 return -EINVAL;
 490                         }
 491                 }
 492         }
 493
 494         lnet_net_unlock(cpt);
 495         return 0;
 496 }
 497
 498 int
 499 lnet_del_route(__u32 net, lnet_nid_t gw_nid)
 500 {
 501         struct lnet_peer_ni     *gateway;
 502         lnet_remotenet_t        *rnet;
 503         lnet_route_t            *route;
 504         struct list_head        *e1;
 505         struct list_head        *e2;
 506         int                     rc = -ENOENT;
 507         struct list_head        *rn_list;
 508         int                     idx = 0;
 509
 510         CDEBUG(D_NET, "Del route: net %s : gw %s\n",
 511                libcfs_net2str(net), libcfs_nid2str(gw_nid));
 512
 513         /* NB Caller may specify either all routes via the given gateway
 514          * or a specific route entry actual NIDs) */
 515
 516         lnet_net_lock(LNET_LOCK_EX);
 517         if (net == LNET_NIDNET(LNET_NID_ANY))
 518                 rn_list = &the_lnet.ln_remote_nets_hash[0];
 519         else
 520                 rn_list = lnet_net2rnethash(net);
 521
 522 again:
 523         list_for_each(e1, rn_list) {
 524                 rnet = list_entry(e1, lnet_remotenet_t, lrn_list);
 525
 526                 if (!(net == LNET_NIDNET(LNET_NID_ANY) ||
 527                         net == rnet->lrn_net))
 528                         continue;
 529
 530                 list_for_each(e2, &rnet->lrn_routes) {
 531                         route = list_entry(e2, lnet_route_t, lr_list);
 532
 533                         gateway = route->lr_gateway;
 534                         if (!(gw_nid == LNET_NID_ANY ||
 535                               gw_nid == gateway->lpni_nid))
 536                                 continue;
 537
 538                         list_del(&route->lr_list);
 539                         list_del(&route->lr_gwlist);
 540                         the_lnet.ln_remote_nets_version++;
 541
 542                         if (list_empty(&rnet->lrn_routes))
 543                                 list_del(&rnet->lrn_list);
 544                         else
 545                                 rnet = NULL;
 546
 547                         lnet_rtr_decref_locked(gateway);
 548                         lnet_peer_ni_decref_locked(gateway);
 549
 550                         lnet_net_unlock(LNET_LOCK_EX);
 551
 552                         LIBCFS_FREE(route, sizeof(*route));
 553
 554                         if (rnet != NULL)
 555                                 LIBCFS_FREE(rnet, sizeof(*rnet));
 556
 557                         rc = 0;
 558                         lnet_net_lock(LNET_LOCK_EX);
 559                         goto again;
 560                 }
 561         }
 562
 563         if (net == LNET_NIDNET(LNET_NID_ANY) &&
 564             ++idx < LNET_REMOTE_NETS_HASH_SIZE) {
 565                 rn_list = &the_lnet.ln_remote_nets_hash[idx];
 566                 goto again;
 567         }
 568         lnet_net_unlock(LNET_LOCK_EX);
 569
 570         return rc;
 571 }
 572
 573 void
 574 lnet_destroy_routes (void)
 575 {
 576         lnet_del_route(LNET_NIDNET(LNET_NID_ANY), LNET_NID_ANY);
 577 }
 578
 579 int lnet_get_rtr_pool_cfg(int idx, struct lnet_ioctl_pool_cfg *pool_cfg)
 580 {
 581         int i, rc = -ENOENT, j;
 582
 583         if (the_lnet.ln_rtrpools == NULL)
 584                 return rc;
 585
 586         for (i = 0; i < LNET_NRBPOOLS; i++) {
 587                 lnet_rtrbufpool_t *rbp;
 588
 589                 lnet_net_lock(LNET_LOCK_EX);
 590                 cfs_percpt_for_each(rbp, j, the_lnet.ln_rtrpools) {
 591                         if (i++ != idx)
 592                                 continue;
 593
 594                         pool_cfg->pl_pools[i].pl_npages = rbp[i].rbp_npages;
 595                         pool_cfg->pl_pools[i].pl_nbuffers = rbp[i].rbp_nbuffers;
 596                         pool_cfg->pl_pools[i].pl_credits = rbp[i].rbp_credits;
 597                         pool_cfg->pl_pools[i].pl_mincredits = rbp[i].rbp_mincredits;
 598                         rc = 0;
 599                         break;
 600                 }
 601                 lnet_net_unlock(LNET_LOCK_EX);
 602         }
 603
 604         lnet_net_lock(LNET_LOCK_EX);
 605         pool_cfg->pl_routing = the_lnet.ln_routing;
 606         lnet_net_unlock(LNET_LOCK_EX);
 607
 608         return rc;
 609 }
 610
 611 int
 612 lnet_get_route(int idx, __u32 *net, __u32 *hops,
 613                lnet_nid_t *gateway, __u32 *alive, __u32 *priority)
 614 {
 615         struct list_head *e1;
 616         struct list_head *e2;
 617         lnet_remotenet_t *rnet;
 618         lnet_route_t     *route;
 619         int               cpt;
 620         int               i;
 621         struct list_head *rn_list;
 622
 623         cpt = lnet_net_lock_current();
 624
 625         for (i = 0; i < LNET_REMOTE_NETS_HASH_SIZE; i++) {
 626                 rn_list = &the_lnet.ln_remote_nets_hash[i];
 627                 list_for_each(e1, rn_list) {
 628                         rnet = list_entry(e1, lnet_remotenet_t, lrn_list);
 629
 630                         list_for_each(e2, &rnet->lrn_routes) {
 631                                 route = list_entry(e2, lnet_route_t,
 632                                                    lr_list);
 633
 634                                 if (idx-- == 0) {
 635                                         *net      = rnet->lrn_net;
 636                                         *hops     = route->lr_hops;
 637                                         *priority = route->lr_priority;
 638                                         *gateway  = route->lr_gateway->lpni_nid;
 639                                         *alive    = lnet_is_route_alive(route);
 640                                         lnet_net_unlock(cpt);
 641                                         return 0;
 642                                 }
 643                         }
 644                 }
 645         }
 646
 647         lnet_net_unlock(cpt);
 648         return -ENOENT;
 649 }
 650
 651 void
 652 lnet_swap_pinginfo(struct lnet_ping_info *info)
 653 {
 654         int               i;
 655         struct lnet_ni_status *stat;
 656
 657         __swab32s(&info->pi_magic);
 658         __swab32s(&info->pi_features);
 659         __swab32s(&info->pi_pid);
 660         __swab32s(&info->pi_nnis);
 661         for (i = 0; i < info->pi_nnis && i < LNET_MAX_RTR_NIS; i++) {
 662                 stat = &info->pi_ni[i];
 663                 __swab64s(&stat->ns_nid);
 664                 __swab32s(&stat->ns_status);
 665         }
 666         return;
 667 }
 668
 669 /**
 670  * parse router-checker pinginfo, record number of down NIs for remote
 671  * networks on that router.
 672  */
 673 static void
 674 lnet_parse_rc_info(lnet_rc_data_t *rcd)
 675 {
 676         struct lnet_ping_info   *info = rcd->rcd_pinginfo;
 677         struct lnet_peer_ni     *gw   = rcd->rcd_gateway;
 678         lnet_route_t            *rte;
 679
 680         if (!gw->lpni_alive)
 681                 return;
 682
 683         /*
 684          * Protect gw->lpni_ping_feats. This can be set from
 685          * lnet_notify_locked with different locks being held
 686          */
 687         spin_lock(&gw->lpni_lock);
 688
 689         if (info->pi_magic == __swab32(LNET_PROTO_PING_MAGIC))
 690                 lnet_swap_pinginfo(info);
 691
 692         /* NB always racing with network! */
 693         if (info->pi_magic != LNET_PROTO_PING_MAGIC) {
 694                 CDEBUG(D_NET, "%s: Unexpected magic %08x\n",
 695                        libcfs_nid2str(gw->lpni_nid), info->pi_magic);
 696                 gw->lpni_ping_feats = LNET_PING_FEAT_INVAL;
 697                 spin_unlock(&gw->lpni_lock);
 698                 return;
 699         }
 700
 701         gw->lpni_ping_feats = info->pi_features;
 702         if ((gw->lpni_ping_feats & LNET_PING_FEAT_MASK) == 0) {
 703                 CDEBUG(D_NET, "%s: Unexpected features 0x%x\n",
 704                        libcfs_nid2str(gw->lpni_nid), gw->lpni_ping_feats);
 705                 spin_unlock(&gw->lpni_lock);
 706                 return; /* nothing I can understand */
 707         }
 708
 709         if ((gw->lpni_ping_feats & LNET_PING_FEAT_NI_STATUS) == 0) {
 710                 spin_unlock(&gw->lpni_lock);
 711                 return; /* can't carry NI status info */
 712         }
 713
 714         list_for_each_entry(rte, &gw->lpni_routes, lr_gwlist) {
 715                 int     down = 0;
 716                 int     up = 0;
 717                 int     i;
 718
 719                 if ((gw->lpni_ping_feats & LNET_PING_FEAT_RTE_DISABLED) != 0) {
 720                         rte->lr_downis = 1;
 721                         continue;
 722                 }
 723
 724                 for (i = 0; i < info->pi_nnis && i < LNET_MAX_RTR_NIS; i++) {
 725                         struct lnet_ni_status *stat = &info->pi_ni[i];
 726                         lnet_nid_t       nid = stat->ns_nid;
 727
 728                         if (nid == LNET_NID_ANY) {
 729                                 CDEBUG(D_NET, "%s: unexpected LNET_NID_ANY\n",
 730                                        libcfs_nid2str(gw->lpni_nid));
 731                                 gw->lpni_ping_feats = LNET_PING_FEAT_INVAL;
 732                                 spin_unlock(&gw->lpni_lock);
 733                                 return;
 734                         }
 735
 736                         if (LNET_NETTYP(LNET_NIDNET(nid)) == LOLND)
 737                                 continue;
 738
 739                         if (stat->ns_status == LNET_NI_STATUS_DOWN) {
 740                                 down++;
 741                                 continue;
 742                         }
 743
 744                         if (stat->ns_status == LNET_NI_STATUS_UP) {
 745                                 if (LNET_NIDNET(nid) == rte->lr_net) {
 746                                         up = 1;
 747                                         break;
 748                                 }
 749                                 continue;
 750                         }
 751
 752                         CDEBUG(D_NET, "%s: Unexpected status 0x%x\n",
 753                                libcfs_nid2str(gw->lpni_nid), stat->ns_status);
 754                         gw->lpni_ping_feats = LNET_PING_FEAT_INVAL;
 755                         spin_unlock(&gw->lpni_lock);
 756                         return;
 757                 }
 758
 759                 if (up) { /* ignore downed NIs if NI for dest network is up */
 760                         rte->lr_downis = 0;
 761                         continue;
 762                 }
 763                 /* if @down is zero and this route is single-hop, it means
 764                  * we can't find NI for target network */
 765                 if (down == 0 && rte->lr_hops == 1)
 766                         down = 1;
 767
 768                 rte->lr_downis = down;
 769         }
 770
 771         spin_unlock(&gw->lpni_lock);
 772 }
 773
 774 static void
 775 lnet_router_checker_event(lnet_event_t *event)
 776 {
 777         lnet_rc_data_t *rcd = event->md.user_ptr;
 778         struct lnet_peer_ni *lp;
 779
 780         LASSERT(rcd != NULL);
 781
 782         if (event->unlinked) {
 783                 LNetInvalidateHandle(&rcd->rcd_mdh);
 784                 return;
 785         }
 786
 787         LASSERT(event->type == LNET_EVENT_SEND ||
 788                 event->type == LNET_EVENT_REPLY);
 789
 790         lp = rcd->rcd_gateway;
 791         LASSERT(lp != NULL);
 792
 793          /* NB: it's called with holding lnet_res_lock, we have a few
 794           * places need to hold both locks at the same time, please take
 795           * care of lock ordering */
 796         lnet_net_lock(lp->lpni_cpt);
 797         if (!lnet_isrouter(lp) || lp->lpni_rcd != rcd) {
 798                 /* ignore if no longer a router or rcd is replaced */
 799                 goto out;
 800         }
 801
 802         if (event->type == LNET_EVENT_SEND) {
 803                 lp->lpni_ping_notsent = 0;
 804                 if (event->status == 0)
 805                         goto out;
 806         }
 807
 808         /* LNET_EVENT_REPLY */
 809         /* A successful REPLY means the router is up.  If _any_ comms
 810          * to the router fail I assume it's down (this will happen if
 811          * we ping alive routers to try to detect router death before
 812          * apps get burned). */
 813
 814         lnet_notify_locked(lp, 1, (event->status == 0), cfs_time_current());
 815         /* The router checker will wake up very shortly and do the
 816          * actual notification.
 817          * XXX If 'lp' stops being a router before then, it will still
 818          * have the notification pending!!! */
 819
 820         if (avoid_asym_router_failure && event->status == 0)
 821                 lnet_parse_rc_info(rcd);
 822
 823  out:
 824         lnet_net_unlock(lp->lpni_cpt);
 825 }
 826
 827 static void
 828 lnet_wait_known_routerstate(void)
 829 {
 830         struct lnet_peer_ni *rtr;
 831         struct list_head *entry;
 832         int all_known;
 833
 834         LASSERT(the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING);
 835
 836         for (;;) {
 837                 int cpt = lnet_net_lock_current();
 838
 839                 all_known = 1;
 840                 list_for_each(entry, &the_lnet.ln_routers) {
 841                         rtr = list_entry(entry, struct lnet_peer_ni,
 842                                          lpni_rtr_list);
 843
 844                         spin_lock(&rtr->lpni_lock);
 845
 846                         if (rtr->lpni_alive_count == 0) {
 847                                 all_known = 0;
 848                                 spin_unlock(&rtr->lpni_lock);
 849                                 break;
 850                         }
 851                         spin_unlock(&rtr->lpni_lock);
 852                 }
 853
 854                 lnet_net_unlock(cpt);
 855
 856                 if (all_known)
 857                         return;
 858
 859                 set_current_state(TASK_UNINTERRUPTIBLE);
 860                 schedule_timeout(cfs_time_seconds(1));
 861         }
 862 }
 863
 864 void
 865 lnet_router_ni_update_locked(struct lnet_peer_ni *gw, __u32 net)
 866 {
 867         lnet_route_t *rte;
 868
 869         if ((gw->lpni_ping_feats & LNET_PING_FEAT_NI_STATUS) != 0) {
 870                 list_for_each_entry(rte, &gw->lpni_routes, lr_gwlist) {
 871                         if (rte->lr_net == net) {
 872                                 rte->lr_downis = 0;
 873                                 break;
 874                         }
 875                 }
 876         }
 877 }
 878
 879 static void
 880 lnet_update_ni_status_locked(void)
 881 {
 882         lnet_ni_t       *ni = NULL;
 883         time64_t        now;
 884         int             timeout;
 885
 886         LASSERT(the_lnet.ln_routing);
 887
 888         timeout = router_ping_timeout +
 889                   MAX(live_router_check_interval, dead_router_check_interval);
 890
 891         now = ktime_get_real_seconds();
 892         while ((ni = lnet_get_next_ni_locked(NULL, ni))) {
 893                 if (ni->ni_net->net_lnd->lnd_type == LOLND)
 894                         continue;
 895
 896                 if (now < ni->ni_last_alive + timeout)
 897                         continue;
 898
 899                 lnet_ni_lock(ni);
 900                 /* re-check with lock */
 901                 if (now < ni->ni_last_alive + timeout) {
 902                         lnet_ni_unlock(ni);
 903                         continue;
 904                 }
 905
 906                 LASSERT(ni->ni_status != NULL);
 907
 908                 if (ni->ni_status->ns_status != LNET_NI_STATUS_DOWN) {
 909                         CDEBUG(D_NET, "NI(%s:%d) status changed to down\n",
 910                                libcfs_nid2str(ni->ni_nid), timeout);
 911                         /* NB: so far, this is the only place to set
 912                          * NI status to "down" */
 913                         ni->ni_status->ns_status = LNET_NI_STATUS_DOWN;
 914                 }
 915                 lnet_ni_unlock(ni);
 916         }
 917 }
 918
 919 static void
 920 lnet_destroy_rc_data(lnet_rc_data_t *rcd)
 921 {
 922         LASSERT(list_empty(&rcd->rcd_list));
 923         /* detached from network */
 924         LASSERT(LNetHandleIsInvalid(rcd->rcd_mdh));
 925
 926         if (rcd->rcd_gateway != NULL) {
 927                 int cpt = rcd->rcd_gateway->lpni_cpt;
 928
 929                 lnet_net_lock(cpt);
 930                 lnet_peer_ni_decref_locked(rcd->rcd_gateway);
 931                 lnet_net_unlock(cpt);
 932         }
 933
 934         if (rcd->rcd_pinginfo != NULL)
 935                 LIBCFS_FREE(rcd->rcd_pinginfo, LNET_PINGINFO_SIZE);
 936
 937         LIBCFS_FREE(rcd, sizeof(*rcd));
 938 }
 939
 940 static lnet_rc_data_t *
 941 lnet_create_rc_data_locked(struct lnet_peer_ni *gateway)
 942 {
 943         lnet_rc_data_t          *rcd = NULL;
 944         struct lnet_ping_info   *pi;
 945         int                     rc;
 946         int                     i;
 947
 948         lnet_net_unlock(gateway->lpni_cpt);
 949
 950         LIBCFS_ALLOC(rcd, sizeof(*rcd));
 951         if (rcd == NULL)
 952                 goto out;
 953
 954         LNetInvalidateHandle(&rcd->rcd_mdh);
 955         INIT_LIST_HEAD(&rcd->rcd_list);
 956
 957         LIBCFS_ALLOC(pi, LNET_PINGINFO_SIZE);
 958         if (pi == NULL)
 959                 goto out;
 960
 961         for (i = 0; i < LNET_MAX_RTR_NIS; i++) {
 962                 pi->pi_ni[i].ns_nid = LNET_NID_ANY;
 963                 pi->pi_ni[i].ns_status = LNET_NI_STATUS_INVALID;
 964         }
 965         rcd->rcd_pinginfo = pi;
 966
 967         LASSERT(!LNetHandleIsInvalid(the_lnet.ln_rc_eqh));
 968         rc = LNetMDBind((lnet_md_t){.start     = pi,
 969                                     .user_ptr  = rcd,
 970                                     .length    = LNET_PINGINFO_SIZE,
 971                                     .threshold = LNET_MD_THRESH_INF,
 972                                     .options   = LNET_MD_TRUNCATE,
 973                                     .eq_handle = the_lnet.ln_rc_eqh},
 974                         LNET_UNLINK,
 975                         &rcd->rcd_mdh);
 976         if (rc < 0) {
 977                 CERROR("Can't bind MD: %d\n", rc);
 978                 goto out;
 979         }
 980         LASSERT(rc == 0);
 981
 982         lnet_net_lock(gateway->lpni_cpt);
 983         /* router table changed or someone has created rcd for this gateway */
 984         if (!lnet_isrouter(gateway) || gateway->lpni_rcd != NULL) {
 985                 lnet_net_unlock(gateway->lpni_cpt);
 986                 goto out;
 987         }
 988
 989         lnet_peer_ni_addref_locked(gateway);
 990         rcd->rcd_gateway = gateway;
 991         gateway->lpni_rcd = rcd;
 992         gateway->lpni_ping_notsent = 0;
 993
 994         return rcd;
 995
 996 out:
 997         if (rcd != NULL) {
 998                 if (!LNetHandleIsInvalid(rcd->rcd_mdh)) {
 999                         rc = LNetMDUnlink(rcd->rcd_mdh);
1000                         LASSERT(rc == 0);
1001                 }
1002                 lnet_destroy_rc_data(rcd);
1003         }
1004
1005         lnet_net_lock(gateway->lpni_cpt);
1006         return gateway->lpni_rcd;
1007 }
1008
1009 static int
1010 lnet_router_check_interval (struct lnet_peer_ni *rtr)
1011 {
1012         int secs;
1013
1014         secs = rtr->lpni_alive ? live_router_check_interval :
1015                                dead_router_check_interval;
1016         if (secs < 0)
1017                 secs = 0;
1018
1019         return secs;
1020 }
1021
1022 static void
1023 lnet_ping_router_locked (struct lnet_peer_ni *rtr)
1024 {
1025         lnet_rc_data_t *rcd = NULL;
1026         cfs_time_t      now = cfs_time_current();
1027         int             secs;
1028         struct lnet_ni  *ni;
1029
1030         lnet_peer_ni_addref_locked(rtr);
1031
1032         if (rtr->lpni_ping_deadline != 0 && /* ping timed out? */
1033             cfs_time_after(now, rtr->lpni_ping_deadline))
1034                 lnet_notify_locked(rtr, 1, 0, now);
1035
1036         /* Run any outstanding notifications */
1037         ni = lnet_get_next_ni_locked(rtr->lpni_net, NULL);
1038         lnet_ni_notify_locked(ni, rtr);
1039
1040         if (!lnet_isrouter(rtr) ||
1041             the_lnet.ln_rc_state != LNET_RC_STATE_RUNNING) {
1042                 /* router table changed or router checker is shutting down */
1043                 lnet_peer_ni_decref_locked(rtr);
1044                 return;
1045         }
1046
1047         rcd = rtr->lpni_rcd != NULL ?
1048               rtr->lpni_rcd : lnet_create_rc_data_locked(rtr);
1049
1050         if (rcd == NULL)
1051                 return;
1052
1053         secs = lnet_router_check_interval(rtr);
1054
1055         CDEBUG(D_NET,
1056                "rtr %s %d: deadline %lu ping_notsent %d alive %d "
1057                "alive_count %d lpni_ping_timestamp %lu\n",
1058                libcfs_nid2str(rtr->lpni_nid), secs,
1059                rtr->lpni_ping_deadline, rtr->lpni_ping_notsent,
1060                rtr->lpni_alive, rtr->lpni_alive_count, rtr->lpni_ping_timestamp);
1061
1062         if (secs != 0 && !rtr->lpni_ping_notsent &&
1063             cfs_time_after(now, cfs_time_add(rtr->lpni_ping_timestamp,
1064                                              cfs_time_seconds(secs)))) {
1065                 int               rc;
1066                 lnet_process_id_t id;
1067                 lnet_handle_md_t  mdh;
1068
1069                 id.nid = rtr->lpni_nid;
1070                 id.pid = LNET_PID_LUSTRE;
1071                 CDEBUG(D_NET, "Check: %s\n", libcfs_id2str(id));
1072
1073                 rtr->lpni_ping_notsent   = 1;
1074                 rtr->lpni_ping_timestamp = now;
1075
1076                 mdh = rcd->rcd_mdh;
1077
1078                 if (rtr->lpni_ping_deadline == 0) {
1079                         rtr->lpni_ping_deadline =
1080                                 cfs_time_shift(router_ping_timeout);
1081                 }
1082
1083                 lnet_net_unlock(rtr->lpni_cpt);
1084
1085                 rc = LNetGet(LNET_NID_ANY, mdh, id, LNET_RESERVED_PORTAL,
1086                              LNET_PROTO_PING_MATCHBITS, 0);
1087
1088                 lnet_net_lock(rtr->lpni_cpt);
1089                 if (rc != 0)
1090                         rtr->lpni_ping_notsent = 0; /* no event pending */
1091         }
1092
1093         lnet_peer_ni_decref_locked(rtr);
1094         return;
1095 }
1096
1097 int
1098 lnet_router_checker_start(void)
1099 {
1100         int                     rc;
1101         int                     eqsz = 0;
1102         struct task_struct     *task;
1103
1104         LASSERT(the_lnet.ln_rc_state == LNET_RC_STATE_SHUTDOWN);
1105
1106         if (check_routers_before_use &&
1107             dead_router_check_interval <= 0) {
1108                 LCONSOLE_ERROR_MSG(0x10a, "'dead_router_check_interval' must be"
1109                                    " set if 'check_routers_before_use' is set"
1110                                    "\n");
1111                 return -EINVAL;
1112         }
1113
1114         sema_init(&the_lnet.ln_rc_signal, 0);
1115
1116         rc = LNetEQAlloc(0, lnet_router_checker_event, &the_lnet.ln_rc_eqh);
1117         if (rc != 0) {
1118                 CERROR("Can't allocate EQ(%d): %d\n", eqsz, rc);
1119                 return -ENOMEM;
1120         }
1121
1122         the_lnet.ln_rc_state = LNET_RC_STATE_RUNNING;
1123         task = kthread_run(lnet_router_checker, NULL, "router_checker");
1124         if (IS_ERR(task)) {
1125                 rc = PTR_ERR(task);
1126                 CERROR("Can't start router checker thread: %d\n", rc);
1127                 /* block until event callback signals exit */
1128                 down(&the_lnet.ln_rc_signal);
1129                 rc = LNetEQFree(the_lnet.ln_rc_eqh);
1130                 LASSERT(rc == 0);
1131                 the_lnet.ln_rc_state = LNET_RC_STATE_SHUTDOWN;
1132                 return -ENOMEM;
1133         }
1134
1135         if (check_routers_before_use) {
1136                 /* Note that a helpful side-effect of pinging all known routers
1137                  * at startup is that it makes them drop stale connections they
1138                  * may have to a previous instance of me. */
1139                 lnet_wait_known_routerstate();
1140         }
1141
1142         return 0;
1143 }
1144
1145 void
1146 lnet_router_checker_stop (void)
1147 {
1148         int rc;
1149
1150         if (the_lnet.ln_rc_state == LNET_RC_STATE_SHUTDOWN)
1151                 return;
1152
1153         LASSERT (the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING);
1154         the_lnet.ln_rc_state = LNET_RC_STATE_STOPPING;
1155         /* wakeup the RC thread if it's sleeping */
1156         wake_up(&the_lnet.ln_rc_waitq);
1157
1158         /* block until event callback signals exit */
1159         down(&the_lnet.ln_rc_signal);
1160         LASSERT(the_lnet.ln_rc_state == LNET_RC_STATE_SHUTDOWN);
1161
1162         rc = LNetEQFree(the_lnet.ln_rc_eqh);
1163         LASSERT(rc == 0);
1164         return;
1165 }
1166
1167 static void
1168 lnet_prune_rc_data(int wait_unlink)
1169 {
1170         lnet_rc_data_t          *rcd;
1171         lnet_rc_data_t          *tmp;
1172         struct lnet_peer_ni     *lp;
1173         struct list_head         head;
1174         int                      i = 2;
1175
1176         if (likely(the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING &&
1177                    list_empty(&the_lnet.ln_rcd_deathrow) &&
1178                    list_empty(&the_lnet.ln_rcd_zombie)))
1179                 return;
1180
1181         INIT_LIST_HEAD(&head);
1182
1183         lnet_net_lock(LNET_LOCK_EX);
1184
1185         if (the_lnet.ln_rc_state != LNET_RC_STATE_RUNNING) {
1186                 /* router checker is stopping, prune all */
1187                 list_for_each_entry(lp, &the_lnet.ln_routers,
1188                                     lpni_rtr_list) {
1189                         if (lp->lpni_rcd == NULL)
1190                                 continue;
1191
1192                         LASSERT(list_empty(&lp->lpni_rcd->rcd_list));
1193                         list_add(&lp->lpni_rcd->rcd_list,
1194                                  &the_lnet.ln_rcd_deathrow);
1195                         lp->lpni_rcd = NULL;
1196                 }
1197         }
1198
1199         /* unlink all RCDs on deathrow list */
1200         list_splice_init(&the_lnet.ln_rcd_deathrow, &head);
1201
1202         if (!list_empty(&head)) {
1203                 lnet_net_unlock(LNET_LOCK_EX);
1204
1205                 list_for_each_entry(rcd, &head, rcd_list)
1206                         LNetMDUnlink(rcd->rcd_mdh);
1207
1208                 lnet_net_lock(LNET_LOCK_EX);
1209         }
1210
1211         list_splice_init(&head, &the_lnet.ln_rcd_zombie);
1212
1213         /* release all zombie RCDs */
1214         while (!list_empty(&the_lnet.ln_rcd_zombie)) {
1215                 list_for_each_entry_safe(rcd, tmp, &the_lnet.ln_rcd_zombie,
1216                                          rcd_list) {
1217                         if (LNetHandleIsInvalid(rcd->rcd_mdh))
1218                                 list_move(&rcd->rcd_list, &head);
1219                 }
1220
1221                 wait_unlink = wait_unlink &&
1222                               !list_empty(&the_lnet.ln_rcd_zombie);
1223
1224                 lnet_net_unlock(LNET_LOCK_EX);
1225
1226                 while (!list_empty(&head)) {
1227                         rcd = list_entry(head.next,
1228                                          lnet_rc_data_t, rcd_list);
1229                         list_del_init(&rcd->rcd_list);
1230                         lnet_destroy_rc_data(rcd);
1231                 }
1232
1233                 if (!wait_unlink)
1234                         return;
1235
1236                 i++;
1237                 CDEBUG(((i & (-i)) == i) ? D_WARNING : D_NET,
1238                        "Waiting for rc buffers to unlink\n");
1239                 set_current_state(TASK_UNINTERRUPTIBLE);
1240                 schedule_timeout(cfs_time_seconds(1) / 4);
1241
1242                 lnet_net_lock(LNET_LOCK_EX);
1243         }
1244
1245         lnet_net_unlock(LNET_LOCK_EX);
1246 }
1247
1248 /*
1249  * This function is called to check if the RC should block indefinitely.
1250  * It's called from lnet_router_checker() as well as being passed to
1251  * wait_event_interruptible() to avoid the lost wake_up problem.
1252  *
1253  * When it's called from wait_event_interruptible() it is necessary to
1254  * also not sleep if the rc state is not running to avoid a deadlock
1255  * when the system is shutting down
1256  */
1257 static inline bool
1258 lnet_router_checker_active(void)
1259 {
1260         if (the_lnet.ln_rc_state != LNET_RC_STATE_RUNNING)
1261                 return true;
1262
1263         /* Router Checker thread needs to run when routing is enabled in
1264          * order to call lnet_update_ni_status_locked() */
1265         if (the_lnet.ln_routing)
1266                 return true;
1267
1268         return !list_empty(&the_lnet.ln_routers) &&
1269                 (live_router_check_interval > 0 ||
1270                  dead_router_check_interval > 0);
1271 }
1272
1273 static int
1274 lnet_router_checker(void *arg)
1275 {
1276         struct lnet_peer_ni *rtr;
1277         struct list_head *entry;
1278
1279         cfs_block_allsigs();
1280
1281         while (the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING) {
1282                 __u64   version;
1283                 int     cpt;
1284                 int     cpt2;
1285
1286                 cpt = lnet_net_lock_current();
1287 rescan:
1288                 version = the_lnet.ln_routers_version;
1289
1290                 list_for_each(entry, &the_lnet.ln_routers) {
1291                         rtr = list_entry(entry, struct lnet_peer_ni,
1292                                          lpni_rtr_list);
1293
1294                         cpt2 = rtr->lpni_cpt;
1295                         if (cpt != cpt2) {
1296                                 lnet_net_unlock(cpt);
1297                                 cpt = cpt2;
1298                                 lnet_net_lock(cpt);
1299                                 /* the routers list has changed */
1300                                 if (version != the_lnet.ln_routers_version)
1301                                         goto rescan;
1302                         }
1303
1304                         lnet_ping_router_locked(rtr);
1305
1306                         /* NB dropped lock */
1307                         if (version != the_lnet.ln_routers_version) {
1308                                 /* the routers list has changed */
1309                                 goto rescan;
1310                         }
1311                 }
1312
1313                 if (the_lnet.ln_routing)
1314                         lnet_update_ni_status_locked();
1315
1316                 lnet_net_unlock(cpt);
1317
1318                 lnet_prune_rc_data(0); /* don't wait for UNLINK */
1319
1320                 /* Call schedule_timeout() here always adds 1 to load average
1321                  * because kernel counts # active tasks as nr_running
1322                  * + nr_uninterruptible. */
1323                 /* if there are any routes then wakeup every second.  If
1324                  * there are no routes then sleep indefinitely until woken
1325                  * up by a user adding a route */
1326                 if (!lnet_router_checker_active())
1327                         wait_event_interruptible(the_lnet.ln_rc_waitq,
1328                                                  lnet_router_checker_active());
1329                 else
1330                         wait_event_interruptible_timeout(the_lnet.ln_rc_waitq,
1331                                                          false,
1332                                                          cfs_time_seconds(1));
1333         }
1334
1335         lnet_prune_rc_data(1); /* wait for UNLINK */
1336
1337         the_lnet.ln_rc_state = LNET_RC_STATE_SHUTDOWN;
1338         up(&the_lnet.ln_rc_signal);
1339         /* The unlink event callback will signal final completion */
1340         return 0;
1341 }
1342
1343 void
1344 lnet_destroy_rtrbuf(lnet_rtrbuf_t *rb, int npages)
1345 {
1346         int sz = offsetof(lnet_rtrbuf_t, rb_kiov[npages]);
1347
1348         while (--npages >= 0)
1349                 __free_page(rb->rb_kiov[npages].kiov_page);
1350
1351         LIBCFS_FREE(rb, sz);
1352 }
1353
1354 static lnet_rtrbuf_t *
1355 lnet_new_rtrbuf(lnet_rtrbufpool_t *rbp, int cpt)
1356 {
1357         int            npages = rbp->rbp_npages;
1358         int            sz = offsetof(lnet_rtrbuf_t, rb_kiov[npages]);
1359         struct page   *page;
1360         lnet_rtrbuf_t *rb;
1361         int            i;
1362
1363         LIBCFS_CPT_ALLOC(rb, lnet_cpt_table(), cpt, sz);
1364         if (rb == NULL)
1365                 return NULL;
1366
1367         rb->rb_pool = rbp;
1368
1369         for (i = 0; i < npages; i++) {
1370                 page = cfs_page_cpt_alloc(lnet_cpt_table(), cpt,
1371                                           GFP_KERNEL | __GFP_ZERO);
1372                 if (page == NULL) {
1373                         while (--i >= 0)
1374                                 __free_page(rb->rb_kiov[i].kiov_page);
1375
1376                         LIBCFS_FREE(rb, sz);
1377                         return NULL;
1378                 }
1379
1380                 rb->rb_kiov[i].kiov_len = PAGE_SIZE;
1381                 rb->rb_kiov[i].kiov_offset = 0;
1382                 rb->rb_kiov[i].kiov_page = page;
1383         }
1384
1385         return rb;
1386 }
1387
1388 static void
1389 lnet_rtrpool_free_bufs(lnet_rtrbufpool_t *rbp, int cpt)
1390 {
1391         int              npages = rbp->rbp_npages;
1392         lnet_rtrbuf_t    *rb;
1393         struct list_head tmp;
1394
1395         if (rbp->rbp_nbuffers == 0) /* not initialized or already freed */
1396                 return;
1397
1398         INIT_LIST_HEAD(&tmp);
1399
1400         lnet_net_lock(cpt);
1401         lnet_drop_routed_msgs_locked(&rbp->rbp_msgs, cpt);
1402         list_splice_init(&rbp->rbp_bufs, &tmp);
1403         rbp->rbp_req_nbuffers = 0;
1404         rbp->rbp_nbuffers = rbp->rbp_credits = 0;
1405         rbp->rbp_mincredits = 0;
1406         lnet_net_unlock(cpt);
1407
1408         /* Free buffers on the free list. */
1409         while (!list_empty(&tmp)) {
1410                 rb = list_entry(tmp.next, lnet_rtrbuf_t, rb_list);
1411                 list_del(&rb->rb_list);
1412                 lnet_destroy_rtrbuf(rb, npages);
1413         }
1414 }
1415
1416 static int
1417 lnet_rtrpool_adjust_bufs(lnet_rtrbufpool_t *rbp, int nbufs, int cpt)
1418 {
1419         struct list_head rb_list;
1420         lnet_rtrbuf_t   *rb;
1421         int             num_rb;
1422         int             num_buffers = 0;
1423         int             old_req_nbufs;
1424         int             npages = rbp->rbp_npages;
1425
1426         lnet_net_lock(cpt);
1427         /* If we are called for less buffers than already in the pool, we
1428          * just lower the req_nbuffers number and excess buffers will be
1429          * thrown away as they are returned to the free list.  Credits
1430          * then get adjusted as well.
1431          * If we already have enough buffers allocated to serve the
1432          * increase requested, then we can treat that the same way as we
1433          * do the decrease. */
1434         num_rb = nbufs - rbp->rbp_nbuffers;
1435         if (nbufs <= rbp->rbp_req_nbuffers || num_rb <= 0) {
1436                 rbp->rbp_req_nbuffers = nbufs;
1437                 lnet_net_unlock(cpt);
1438                 return 0;
1439         }
1440         /* store the older value of rbp_req_nbuffers and then set it to
1441          * the new request to prevent lnet_return_rx_credits_locked() from
1442          * freeing buffers that we need to keep around */
1443         old_req_nbufs = rbp->rbp_req_nbuffers;
1444         rbp->rbp_req_nbuffers = nbufs;
1445         lnet_net_unlock(cpt);
1446
1447         INIT_LIST_HEAD(&rb_list);
1448
1449         /* allocate the buffers on a local list first.  If all buffers are
1450          * allocated successfully then join this list to the rbp buffer
1451          * list.  If not then free all allocated buffers. */
1452         while (num_rb-- > 0) {
1453                 rb = lnet_new_rtrbuf(rbp, cpt);
1454                 if (rb == NULL) {
1455                         CERROR("Failed to allocate %d route bufs of %d pages\n",
1456                                nbufs, npages);
1457
1458                         lnet_net_lock(cpt);
1459                         rbp->rbp_req_nbuffers = old_req_nbufs;
1460                         lnet_net_unlock(cpt);
1461
1462                         goto failed;
1463                 }
1464
1465                 list_add(&rb->rb_list, &rb_list);
1466                 num_buffers++;
1467         }
1468
1469         lnet_net_lock(cpt);
1470
1471         list_splice_tail(&rb_list, &rbp->rbp_bufs);
1472         rbp->rbp_nbuffers += num_buffers;
1473         rbp->rbp_credits += num_buffers;
1474         rbp->rbp_mincredits = rbp->rbp_credits;
1475         /* We need to schedule blocked msg using the newly
1476          * added buffers. */
1477         while (!list_empty(&rbp->rbp_bufs) &&
1478                !list_empty(&rbp->rbp_msgs))
1479                 lnet_schedule_blocked_locked(rbp);
1480
1481         lnet_net_unlock(cpt);
1482
1483         return 0;
1484
1485 failed:
1486         while (!list_empty(&rb_list)) {
1487                 rb = list_entry(rb_list.next, lnet_rtrbuf_t, rb_list);
1488                 list_del(&rb->rb_list);
1489                 lnet_destroy_rtrbuf(rb, npages);
1490         }
1491
1492         return -ENOMEM;
1493 }
1494
1495 static void
1496 lnet_rtrpool_init(lnet_rtrbufpool_t *rbp, int npages)
1497 {
1498         INIT_LIST_HEAD(&rbp->rbp_msgs);
1499         INIT_LIST_HEAD(&rbp->rbp_bufs);
1500
1501         rbp->rbp_npages = npages;
1502         rbp->rbp_credits = 0;
1503         rbp->rbp_mincredits = 0;
1504 }
1505
1506 void
1507 lnet_rtrpools_free(int keep_pools)
1508 {
1509         lnet_rtrbufpool_t *rtrp;
1510         int               i;
1511
1512         if (the_lnet.ln_rtrpools == NULL) /* uninitialized or freed */
1513                 return;
1514
1515         cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
1516                 lnet_rtrpool_free_bufs(&rtrp[LNET_TINY_BUF_IDX], i);
1517                 lnet_rtrpool_free_bufs(&rtrp[LNET_SMALL_BUF_IDX], i);
1518                 lnet_rtrpool_free_bufs(&rtrp[LNET_LARGE_BUF_IDX], i);
1519         }
1520
1521         if (!keep_pools) {
1522                 cfs_percpt_free(the_lnet.ln_rtrpools);
1523                 the_lnet.ln_rtrpools = NULL;
1524         }
1525 }
1526
1527 static int
1528 lnet_nrb_tiny_calculate(void)
1529 {
1530         int     nrbs = LNET_NRB_TINY;
1531
1532         if (tiny_router_buffers < 0) {
1533                 LCONSOLE_ERROR_MSG(0x10c,
1534                                    "tiny_router_buffers=%d invalid when "
1535                                    "routing enabled\n", tiny_router_buffers);
1536                 return -EINVAL;
1537         }
1538
1539         if (tiny_router_buffers > 0)
1540                 nrbs = tiny_router_buffers;
1541
1542         nrbs /= LNET_CPT_NUMBER;
1543         return max(nrbs, LNET_NRB_TINY_MIN);
1544 }
1545
1546 static int
1547 lnet_nrb_small_calculate(void)
1548 {
1549         int     nrbs = LNET_NRB_SMALL;
1550
1551         if (small_router_buffers < 0) {
1552                 LCONSOLE_ERROR_MSG(0x10c,
1553                                    "small_router_buffers=%d invalid when "
1554                                    "routing enabled\n", small_router_buffers);
1555                 return -EINVAL;
1556         }
1557
1558         if (small_router_buffers > 0)
1559                 nrbs = small_router_buffers;
1560
1561         nrbs /= LNET_CPT_NUMBER;
1562         return max(nrbs, LNET_NRB_SMALL_MIN);
1563 }
1564
1565 static int
1566 lnet_nrb_large_calculate(void)
1567 {
1568         int     nrbs = LNET_NRB_LARGE;
1569
1570         if (large_router_buffers < 0) {
1571                 LCONSOLE_ERROR_MSG(0x10c,
1572                                    "large_router_buffers=%d invalid when "
1573                                    "routing enabled\n", large_router_buffers);
1574                 return -EINVAL;
1575         }
1576
1577         if (large_router_buffers > 0)
1578                 nrbs = large_router_buffers;
1579
1580         nrbs /= LNET_CPT_NUMBER;
1581         return max(nrbs, LNET_NRB_LARGE_MIN);
1582 }
1583
1584 int
1585 lnet_rtrpools_alloc(int im_a_router)
1586 {
1587         lnet_rtrbufpool_t *rtrp;
1588         int     nrb_tiny;
1589         int     nrb_small;
1590         int     nrb_large;
1591         int     rc;
1592         int     i;
1593
1594         if (!strcmp(forwarding, "")) {
1595                 /* not set either way */
1596                 if (!im_a_router)
1597                         return 0;
1598         } else if (!strcmp(forwarding, "disabled")) {
1599                 /* explicitly disabled */
1600                 return 0;
1601         } else if (!strcmp(forwarding, "enabled")) {
1602                 /* explicitly enabled */
1603         } else {
1604                 LCONSOLE_ERROR_MSG(0x10b, "'forwarding' not set to either "
1605                                    "'enabled' or 'disabled'\n");
1606                 return -EINVAL;
1607         }
1608
1609         nrb_tiny = lnet_nrb_tiny_calculate();
1610         if (nrb_tiny < 0)
1611                 return -EINVAL;
1612
1613         nrb_small = lnet_nrb_small_calculate();
1614         if (nrb_small < 0)
1615                 return -EINVAL;
1616
1617         nrb_large = lnet_nrb_large_calculate();
1618         if (nrb_large < 0)
1619                 return -EINVAL;
1620
1621         the_lnet.ln_rtrpools = cfs_percpt_alloc(lnet_cpt_table(),
1622                                                 LNET_NRBPOOLS *
1623                                                 sizeof(lnet_rtrbufpool_t));
1624         if (the_lnet.ln_rtrpools == NULL) {
1625                 LCONSOLE_ERROR_MSG(0x10c,
1626                                    "Failed to initialize router buffe pool\n");
1627                 return -ENOMEM;
1628         }
1629
1630         cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
1631                 lnet_rtrpool_init(&rtrp[LNET_TINY_BUF_IDX], 0);
1632                 rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_TINY_BUF_IDX],
1633                                               nrb_tiny, i);
1634                 if (rc != 0)
1635                         goto failed;
1636
1637                 lnet_rtrpool_init(&rtrp[LNET_SMALL_BUF_IDX],
1638                                   LNET_NRB_SMALL_PAGES);
1639                 rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_SMALL_BUF_IDX],
1640                                               nrb_small, i);
1641                 if (rc != 0)
1642                         goto failed;
1643
1644                 lnet_rtrpool_init(&rtrp[LNET_LARGE_BUF_IDX],
1645                                   LNET_NRB_LARGE_PAGES);
1646                 rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_LARGE_BUF_IDX],
1647                                               nrb_large, i);
1648                 if (rc != 0)
1649                         goto failed;
1650         }
1651
1652         lnet_net_lock(LNET_LOCK_EX);
1653         the_lnet.ln_routing = 1;
1654         lnet_net_unlock(LNET_LOCK_EX);
1655         return 0;
1656
1657  failed:
1658         lnet_rtrpools_free(0);
1659         return rc;
1660 }
1661
1662 static int
1663 lnet_rtrpools_adjust_helper(int tiny, int small, int large)
1664 {
1665         int nrb = 0;
1666         int rc = 0;
1667         int i;
1668         lnet_rtrbufpool_t *rtrp;
1669
1670         /* If the provided values for each buffer pool are different than the
1671          * configured values, we need to take action. */
1672         if (tiny >= 0) {
1673                 tiny_router_buffers = tiny;
1674                 nrb = lnet_nrb_tiny_calculate();
1675                 cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
1676                         rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_TINY_BUF_IDX],
1677                                                       nrb, i);
1678                         if (rc != 0)
1679                                 return rc;
1680                 }
1681         }
1682         if (small >= 0) {
1683                 small_router_buffers = small;
1684                 nrb = lnet_nrb_small_calculate();
1685                 cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
1686                         rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_SMALL_BUF_IDX],
1687                                                       nrb, i);
1688                         if (rc != 0)
1689                                 return rc;
1690                 }
1691         }
1692         if (large >= 0) {
1693                 large_router_buffers = large;
1694                 nrb = lnet_nrb_large_calculate();
1695                 cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
1696                         rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_LARGE_BUF_IDX],
1697                                                       nrb, i);
1698                         if (rc != 0)
1699                                 return rc;
1700                 }
1701         }
1702
1703         return 0;
1704 }
1705
1706 int
1707 lnet_rtrpools_adjust(int tiny, int small, int large)
1708 {
1709         /* this function doesn't revert the changes if adding new buffers
1710          * failed.  It's up to the user space caller to revert the
1711          * changes. */
1712
1713         if (!the_lnet.ln_routing)
1714                 return 0;
1715
1716         return lnet_rtrpools_adjust_helper(tiny, small, large);
1717 }
1718
1719 int
1720 lnet_rtrpools_enable(void)
1721 {
1722         int rc = 0;
1723
1724         if (the_lnet.ln_routing)
1725                 return 0;
1726
1727         if (the_lnet.ln_rtrpools == NULL)
1728                 /* If routing is turned off, and we have never
1729                  * initialized the pools before, just call the
1730                  * standard buffer pool allocation routine as
1731                  * if we are just configuring this for the first
1732                  * time. */
1733                 rc = lnet_rtrpools_alloc(1);
1734         else
1735                 rc = lnet_rtrpools_adjust_helper(0, 0, 0);
1736         if (rc != 0)
1737                 return rc;
1738
1739         lnet_net_lock(LNET_LOCK_EX);
1740         the_lnet.ln_routing = 1;
1741
1742         the_lnet.ln_ping_info->pi_features &= ~LNET_PING_FEAT_RTE_DISABLED;
1743         lnet_net_unlock(LNET_LOCK_EX);
1744
1745         return rc;
1746 }
1747
1748 void
1749 lnet_rtrpools_disable(void)
1750 {
1751         if (!the_lnet.ln_routing)
1752                 return;
1753
1754         lnet_net_lock(LNET_LOCK_EX);
1755         the_lnet.ln_routing = 0;
1756         the_lnet.ln_ping_info->pi_features |= LNET_PING_FEAT_RTE_DISABLED;
1757
1758         tiny_router_buffers = 0;
1759         small_router_buffers = 0;
1760         large_router_buffers = 0;
1761         lnet_net_unlock(LNET_LOCK_EX);
1762         lnet_rtrpools_free(1);
1763 }
1764
1765 int
1766 lnet_notify(lnet_ni_t *ni, lnet_nid_t nid, int alive, cfs_time_t when)
1767 {
1768         struct lnet_peer_ni *lp = NULL;
1769         cfs_time_t now = cfs_time_current();
1770         int cpt = lnet_cpt_of_nid(nid, ni);
1771
1772         LASSERT (!in_interrupt ());
1773
1774         CDEBUG (D_NET, "%s notifying %s: %s\n",
1775                 (ni == NULL) ? "userspace" : libcfs_nid2str(ni->ni_nid),
1776                 libcfs_nid2str(nid),
1777                 alive ? "up" : "down");
1778
1779         if (ni != NULL &&
1780             LNET_NIDNET(ni->ni_nid) != LNET_NIDNET(nid)) {
1781                 CWARN("Ignoring notification of %s %s by %s (different net)\n",
1782                       libcfs_nid2str(nid), alive ? "birth" : "death",
1783                       libcfs_nid2str(ni->ni_nid));
1784                 return -EINVAL;
1785         }
1786
1787         /* can't do predictions... */
1788         if (cfs_time_after(when, now)) {
1789                 CWARN("Ignoring prediction from %s of %s %s "
1790                       "%ld seconds in the future\n",
1791                       (ni == NULL) ? "userspace" : libcfs_nid2str(ni->ni_nid),
1792                       libcfs_nid2str(nid), alive ? "up" : "down",
1793                       cfs_duration_sec(cfs_time_sub(when, now)));
1794                 return -EINVAL;
1795         }
1796
1797         if (ni != NULL && !alive &&             /* LND telling me she's down */
1798             !auto_down) {                       /* auto-down disabled */
1799                 CDEBUG(D_NET, "Auto-down disabled\n");
1800                 return 0;
1801         }
1802
1803         lnet_net_lock(cpt);
1804
1805         if (the_lnet.ln_shutdown) {
1806                 lnet_net_unlock(cpt);
1807                 return -ESHUTDOWN;
1808         }
1809
1810         lp = lnet_find_peer_ni_locked(nid);
1811         if (lp == NULL) {
1812                 /* nid not found */
1813                 lnet_net_unlock(cpt);
1814                 CDEBUG(D_NET, "%s not found\n", libcfs_nid2str(nid));
1815                 return 0;
1816         }
1817
1818         /*
1819          * It is possible for this function to be called for the same peer
1820          * but with different NIs. We want to synchronize the notification
1821          * between the different calls. So we will use the lpni_cpt to
1822          * grab the net lock.
1823          */
1824         if (lp->lpni_cpt != cpt) {
1825                 lnet_net_unlock(cpt);
1826                 cpt = lp->lpni_cpt;
1827                 lnet_net_lock(cpt);
1828         }
1829
1830         /* We can't fully trust LND on reporting exact peer last_alive
1831          * if he notifies us about dead peer. For example ksocklnd can
1832          * call us with when == _time_when_the_node_was_booted_ if
1833          * no connections were successfully established */
1834         if (ni != NULL && !alive && when < lp->lpni_last_alive)
1835                 when = lp->lpni_last_alive;
1836
1837         lnet_notify_locked(lp, ni == NULL, alive, when);
1838
1839         if (ni != NULL)
1840                 lnet_ni_notify_locked(ni, lp);
1841
1842         lnet_peer_ni_decref_locked(lp);
1843
1844         lnet_net_unlock(cpt);
1845         return 0;
1846 }
1847 EXPORT_SYMBOL(lnet_notify);