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         lp->lpni_timestamp = when;                /* update timestamp */
 110         lp->lpni_ping_deadline = 0;               /* disable ping timeout */
 111
 112         if (lp->lpni_alive_count != 0 &&          /* got old news */
 113             (!lp->lpni_alive) == (!alive)) {      /* new date for old news */
 114                 CDEBUG(D_NET, "Old news\n");
 115                 return;
 116         }
 117
 118         /* Flag that notification is outstanding */
 119
 120         lp->lpni_alive_count++;
 121         lp->lpni_alive = !(!alive);               /* 1 bit! */
 122         lp->lpni_notify = 1;
 123         lp->lpni_notifylnd |= notifylnd;
 124         if (lp->lpni_alive)
 125                 lp->lpni_ping_feats = LNET_PING_FEAT_INVAL; /* reset */
 126
 127         CDEBUG(D_NET, "set %s %d\n", libcfs_nid2str(lp->lpni_nid), alive);
 128 }
 129
 130 static void
 131 lnet_ni_notify_locked(lnet_ni_t *ni, struct lnet_peer_ni *lp)
 132 {
 133         int        alive;
 134         int        notifylnd;
 135
 136         /* Notify only in 1 thread at any time to ensure ordered notification.
 137          * NB individual events can be missed; the only guarantee is that you
 138          * always get the most recent news */
 139
 140         if (lp->lpni_notifying || ni == NULL)
 141                 return;
 142
 143         lp->lpni_notifying = 1;
 144
 145         while (lp->lpni_notify) {
 146                 alive     = lp->lpni_alive;
 147                 notifylnd = lp->lpni_notifylnd;
 148
 149                 lp->lpni_notifylnd = 0;
 150                 lp->lpni_notify    = 0;
 151
 152                 if (notifylnd && ni->ni_net->net_lnd->lnd_notify != NULL) {
 153                         lnet_net_unlock(lp->lpni_cpt);
 154
 155                         /* A new notification could happen now; I'll handle it
 156                          * when control returns to me */
 157
 158                         (ni->ni_net->net_lnd->lnd_notify)(ni, lp->lpni_nid,
 159                                                           alive);
 160
 161                         lnet_net_lock(lp->lpni_cpt);
 162                 }
 163         }
 164
 165         lp->lpni_notifying = 0;
 166 }
 167
 168
 169 static void
 170 lnet_rtr_addref_locked(struct lnet_peer_ni *lp)
 171 {
 172         LASSERT(atomic_read(&lp->lpni_refcount) > 0);
 173         LASSERT(lp->lpni_rtr_refcount >= 0);
 174
 175         /* lnet_net_lock must be exclusively locked */
 176         lp->lpni_rtr_refcount++;
 177         if (lp->lpni_rtr_refcount == 1) {
 178                 struct list_head *pos;
 179
 180                 /* a simple insertion sort */
 181                 list_for_each_prev(pos, &the_lnet.ln_routers) {
 182                         struct lnet_peer_ni *rtr =
 183                           list_entry(pos, struct lnet_peer_ni,
 184                                      lpni_rtr_list);
 185
 186                         if (rtr->lpni_nid < lp->lpni_nid)
 187                                 break;
 188                 }
 189
 190                 list_add(&lp->lpni_rtr_list, pos);
 191                 /* addref for the_lnet.ln_routers */
 192                 lnet_peer_ni_addref_locked(lp);
 193                 the_lnet.ln_routers_version++;
 194         }
 195 }
 196
 197 static void
 198 lnet_rtr_decref_locked(struct lnet_peer_ni *lp)
 199 {
 200         LASSERT(atomic_read(&lp->lpni_refcount) > 0);
 201         LASSERT(lp->lpni_rtr_refcount > 0);
 202
 203         /* lnet_net_lock must be exclusively locked */
 204         lp->lpni_rtr_refcount--;
 205         if (lp->lpni_rtr_refcount == 0) {
 206                 LASSERT(list_empty(&lp->lpni_routes));
 207
 208                 if (lp->lpni_rcd != NULL) {
 209                         list_add(&lp->lpni_rcd->rcd_list,
 210                                  &the_lnet.ln_rcd_deathrow);
 211                         lp->lpni_rcd = NULL;
 212                 }
 213
 214                 list_del(&lp->lpni_rtr_list);
 215                 /* decref for the_lnet.ln_routers */
 216                 lnet_peer_ni_decref_locked(lp);
 217                 the_lnet.ln_routers_version++;
 218         }
 219 }
 220
 221 lnet_remotenet_t *
 222 lnet_find_rnet_locked(__u32 net)
 223 {
 224         lnet_remotenet_t *rnet;
 225         struct list_head *tmp;
 226         struct list_head *rn_list;
 227
 228         LASSERT(!the_lnet.ln_shutdown);
 229
 230         rn_list = lnet_net2rnethash(net);
 231         list_for_each(tmp, rn_list) {
 232                 rnet = list_entry(tmp, lnet_remotenet_t, lrn_list);
 233
 234                 if (rnet->lrn_net == net)
 235                         return rnet;
 236         }
 237         return NULL;
 238 }
 239
 240 static void lnet_shuffle_seed(void)
 241 {
 242         static int seeded;
 243         __u32 lnd_type;
 244         __u32 seed[2];
 245         struct timespec64 ts;
 246         lnet_ni_t *ni = NULL;
 247
 248         if (seeded)
 249                 return;
 250
 251         cfs_get_random_bytes(seed, sizeof(seed));
 252
 253         /* Nodes with small feet have little entropy
 254          * the NID for this node gives the most entropy in the low bits */
 255         while ((ni = lnet_get_next_ni_locked(NULL, ni))) {
 256                 lnd_type = LNET_NETTYP(LNET_NIDNET(ni->ni_nid));
 257
 258                 if (lnd_type != LOLND)
 259                         seed[0] ^= (LNET_NIDADDR(ni->ni_nid) | lnd_type);
 260         }
 261
 262         ktime_get_ts64(&ts);
 263         cfs_srand(ts.tv_sec ^ seed[0], ts.tv_nsec ^ seed[1]);
 264         seeded = 1;
 265         return;
 266 }
 267
 268 /* NB expects LNET_LOCK held */
 269 static void
 270 lnet_add_route_to_rnet(lnet_remotenet_t *rnet, lnet_route_t *route)
 271 {
 272         unsigned int      len = 0;
 273         unsigned int      offset = 0;
 274         struct list_head *e;
 275
 276         lnet_shuffle_seed();
 277
 278         list_for_each(e, &rnet->lrn_routes) {
 279                 len++;
 280         }
 281
 282         /* len+1 positions to add a new entry, also prevents division by 0 */
 283         offset = cfs_rand() % (len + 1);
 284         list_for_each(e, &rnet->lrn_routes) {
 285                 if (offset == 0)
 286                         break;
 287                 offset--;
 288         }
 289         list_add(&route->lr_list, e);
 290         list_add(&route->lr_gwlist, &route->lr_gateway->lpni_routes);
 291
 292         the_lnet.ln_remote_nets_version++;
 293         lnet_rtr_addref_locked(route->lr_gateway);
 294 }
 295
 296 int
 297 lnet_add_route(__u32 net, __u32 hops, lnet_nid_t gateway,
 298                unsigned int priority)
 299 {
 300         struct list_head        *e;
 301         lnet_remotenet_t        *rnet;
 302         lnet_remotenet_t        *rnet2;
 303         lnet_route_t            *route;
 304         lnet_ni_t               *ni;
 305         int                     add_route;
 306         int                     rc;
 307
 308         CDEBUG(D_NET, "Add route: net %s hops %d priority %u gw %s\n",
 309                libcfs_net2str(net), hops, priority, libcfs_nid2str(gateway));
 310
 311         if (gateway == LNET_NID_ANY ||
 312             LNET_NETTYP(LNET_NIDNET(gateway)) == LOLND ||
 313             net == LNET_NIDNET(LNET_NID_ANY) ||
 314             LNET_NETTYP(net) == LOLND ||
 315             LNET_NIDNET(gateway) == net ||
 316             (hops != LNET_UNDEFINED_HOPS && (hops < 1 || hops > 255)))
 317                 return -EINVAL;
 318
 319         if (lnet_islocalnet(net))       /* it's a local network */
 320                 return -EEXIST;
 321
 322         /* Assume net, route, all new */
 323         LIBCFS_ALLOC(route, sizeof(*route));
 324         LIBCFS_ALLOC(rnet, sizeof(*rnet));
 325         if (route == NULL || rnet == NULL) {
 326                 CERROR("Out of memory creating route %s %d %s\n",
 327                        libcfs_net2str(net), hops, libcfs_nid2str(gateway));
 328                 if (route != NULL)
 329                         LIBCFS_FREE(route, sizeof(*route));
 330                 if (rnet != NULL)
 331                         LIBCFS_FREE(rnet, sizeof(*rnet));
 332                 return -ENOMEM;
 333         }
 334
 335         INIT_LIST_HEAD(&rnet->lrn_routes);
 336         rnet->lrn_net = net;
 337         route->lr_hops = hops;
 338         route->lr_net = net;
 339         route->lr_priority = priority;
 340
 341         lnet_net_lock(LNET_LOCK_EX);
 342
 343         rc = lnet_nid2peerni_locked(&route->lr_gateway, gateway, LNET_LOCK_EX);
 344         if (rc != 0) {
 345                 lnet_net_unlock(LNET_LOCK_EX);
 346
 347                 LIBCFS_FREE(route, sizeof(*route));
 348                 LIBCFS_FREE(rnet, sizeof(*rnet));
 349
 350                 if (rc == -EHOSTUNREACH) /* gateway is not on a local net. */
 351                         return rc;       /* ignore the route entry */
 352                 CERROR("Error %d creating route %s %d %s\n", rc,
 353                         libcfs_net2str(net), hops,
 354                         libcfs_nid2str(gateway));
 355                 return rc;
 356         }
 357
 358         LASSERT(!the_lnet.ln_shutdown);
 359
 360         rnet2 = lnet_find_rnet_locked(net);
 361         if (rnet2 == NULL) {
 362                 /* new network */
 363                 list_add_tail(&rnet->lrn_list, lnet_net2rnethash(net));
 364                 rnet2 = rnet;
 365         }
 366
 367         /* Search for a duplicate route (it's a NOOP if it is) */
 368         add_route = 1;
 369         list_for_each(e, &rnet2->lrn_routes) {
 370                 lnet_route_t *route2 = list_entry(e, lnet_route_t, lr_list);
 371
 372                 if (route2->lr_gateway == route->lr_gateway) {
 373                         add_route = 0;
 374                         break;
 375                 }
 376
 377                 /* our lookups must be true */
 378                 LASSERT(route2->lr_gateway->lpni_nid != gateway);
 379         }
 380
 381         if (add_route) {
 382                 lnet_peer_ni_addref_locked(route->lr_gateway); /* +1 for notify */
 383                 lnet_add_route_to_rnet(rnet2, route);
 384
 385                 ni = lnet_get_next_ni_locked(route->lr_gateway->lpni_net, NULL);
 386                 lnet_net_unlock(LNET_LOCK_EX);
 387
 388                 /* XXX Assume alive */
 389                 if (ni->ni_net->net_lnd->lnd_notify != NULL)
 390                         (ni->ni_net->net_lnd->lnd_notify)(ni, gateway, 1);
 391
 392                 lnet_net_lock(LNET_LOCK_EX);
 393         }
 394
 395         /* -1 for notify or !add_route */
 396         lnet_peer_ni_decref_locked(route->lr_gateway);
 397         lnet_net_unlock(LNET_LOCK_EX);
 398
 399         rc = 0;
 400
 401         if (!add_route) {
 402                 rc = -EEXIST;
 403                 LIBCFS_FREE(route, sizeof(*route));
 404         }
 405
 406         if (rnet != rnet2)
 407                 LIBCFS_FREE(rnet, sizeof(*rnet));
 408
 409         /* indicate to startup the router checker if configured */
 410         wake_up(&the_lnet.ln_rc_waitq);
 411
 412         return rc;
 413 }
 414
 415 int
 416 lnet_check_routes(void)
 417 {
 418         lnet_remotenet_t *rnet;
 419         lnet_route_t     *route;
 420         lnet_route_t     *route2;
 421         struct list_head *e1;
 422         struct list_head *e2;
 423         int               cpt;
 424         struct list_head *rn_list;
 425         int               i;
 426
 427         cpt = lnet_net_lock_current();
 428
 429         for (i = 0; i < LNET_REMOTE_NETS_HASH_SIZE; i++) {
 430                 rn_list = &the_lnet.ln_remote_nets_hash[i];
 431                 list_for_each(e1, rn_list) {
 432                         rnet = list_entry(e1, lnet_remotenet_t, lrn_list);
 433
 434                         route2 = NULL;
 435                         list_for_each(e2, &rnet->lrn_routes) {
 436                                 lnet_nid_t      nid1;
 437                                 lnet_nid_t      nid2;
 438                                 int             net;
 439
 440                                 route = list_entry(e2, lnet_route_t,
 441                                                    lr_list);
 442
 443                                 if (route2 == NULL) {
 444                                         route2 = route;
 445                                         continue;
 446                                 }
 447
 448                                 if (route->lr_gateway->lpni_net ==
 449                                     route2->lr_gateway->lpni_net)
 450                                         continue;
 451
 452                                 nid1 = route->lr_gateway->lpni_nid;
 453                                 nid2 = route2->lr_gateway->lpni_nid;
 454                                 net = rnet->lrn_net;
 455
 456                                 lnet_net_unlock(cpt);
 457
 458                                 CERROR("Routes to %s via %s and %s not "
 459                                        "supported\n",
 460                                        libcfs_net2str(net),
 461                                        libcfs_nid2str(nid1),
 462                                        libcfs_nid2str(nid2));
 463                                 return -EINVAL;
 464                         }
 465                 }
 466         }
 467
 468         lnet_net_unlock(cpt);
 469         return 0;
 470 }
 471
 472 int
 473 lnet_del_route(__u32 net, lnet_nid_t gw_nid)
 474 {
 475         struct lnet_peer_ni     *gateway;
 476         lnet_remotenet_t        *rnet;
 477         lnet_route_t            *route;
 478         struct list_head        *e1;
 479         struct list_head        *e2;
 480         int                     rc = -ENOENT;
 481         struct list_head        *rn_list;
 482         int                     idx = 0;
 483
 484         CDEBUG(D_NET, "Del route: net %s : gw %s\n",
 485                libcfs_net2str(net), libcfs_nid2str(gw_nid));
 486
 487         /* NB Caller may specify either all routes via the given gateway
 488          * or a specific route entry actual NIDs) */
 489
 490         lnet_net_lock(LNET_LOCK_EX);
 491         if (net == LNET_NIDNET(LNET_NID_ANY))
 492                 rn_list = &the_lnet.ln_remote_nets_hash[0];
 493         else
 494                 rn_list = lnet_net2rnethash(net);
 495
 496 again:
 497         list_for_each(e1, rn_list) {
 498                 rnet = list_entry(e1, lnet_remotenet_t, lrn_list);
 499
 500                 if (!(net == LNET_NIDNET(LNET_NID_ANY) ||
 501                         net == rnet->lrn_net))
 502                         continue;
 503
 504                 list_for_each(e2, &rnet->lrn_routes) {
 505                         route = list_entry(e2, lnet_route_t, lr_list);
 506
 507                         gateway = route->lr_gateway;
 508                         if (!(gw_nid == LNET_NID_ANY ||
 509                               gw_nid == gateway->lpni_nid))
 510                                 continue;
 511
 512                         list_del(&route->lr_list);
 513                         list_del(&route->lr_gwlist);
 514                         the_lnet.ln_remote_nets_version++;
 515
 516                         if (list_empty(&rnet->lrn_routes))
 517                                 list_del(&rnet->lrn_list);
 518                         else
 519                                 rnet = NULL;
 520
 521                         lnet_rtr_decref_locked(gateway);
 522                         lnet_peer_ni_decref_locked(gateway);
 523
 524                         lnet_net_unlock(LNET_LOCK_EX);
 525
 526                         LIBCFS_FREE(route, sizeof(*route));
 527
 528                         if (rnet != NULL)
 529                                 LIBCFS_FREE(rnet, sizeof(*rnet));
 530
 531                         rc = 0;
 532                         lnet_net_lock(LNET_LOCK_EX);
 533                         goto again;
 534                 }
 535         }
 536
 537         if (net == LNET_NIDNET(LNET_NID_ANY) &&
 538             ++idx < LNET_REMOTE_NETS_HASH_SIZE) {
 539                 rn_list = &the_lnet.ln_remote_nets_hash[idx];
 540                 goto again;
 541         }
 542         lnet_net_unlock(LNET_LOCK_EX);
 543
 544         return rc;
 545 }
 546
 547 void
 548 lnet_destroy_routes (void)
 549 {
 550         lnet_del_route(LNET_NIDNET(LNET_NID_ANY), LNET_NID_ANY);
 551 }
 552
 553 int lnet_get_rtr_pool_cfg(int idx, struct lnet_ioctl_pool_cfg *pool_cfg)
 554 {
 555         int i, rc = -ENOENT, j;
 556
 557         if (the_lnet.ln_rtrpools == NULL)
 558                 return rc;
 559
 560         for (i = 0; i < LNET_NRBPOOLS; i++) {
 561                 lnet_rtrbufpool_t *rbp;
 562
 563                 lnet_net_lock(LNET_LOCK_EX);
 564                 cfs_percpt_for_each(rbp, j, the_lnet.ln_rtrpools) {
 565                         if (i++ != idx)
 566                                 continue;
 567
 568                         pool_cfg->pl_pools[i].pl_npages = rbp[i].rbp_npages;
 569                         pool_cfg->pl_pools[i].pl_nbuffers = rbp[i].rbp_nbuffers;
 570                         pool_cfg->pl_pools[i].pl_credits = rbp[i].rbp_credits;
 571                         pool_cfg->pl_pools[i].pl_mincredits = rbp[i].rbp_mincredits;
 572                         rc = 0;
 573                         break;
 574                 }
 575                 lnet_net_unlock(LNET_LOCK_EX);
 576         }
 577
 578         lnet_net_lock(LNET_LOCK_EX);
 579         pool_cfg->pl_routing = the_lnet.ln_routing;
 580         lnet_net_unlock(LNET_LOCK_EX);
 581
 582         return rc;
 583 }
 584
 585 int
 586 lnet_get_route(int idx, __u32 *net, __u32 *hops,
 587                lnet_nid_t *gateway, __u32 *alive, __u32 *priority)
 588 {
 589         struct list_head *e1;
 590         struct list_head *e2;
 591         lnet_remotenet_t *rnet;
 592         lnet_route_t     *route;
 593         int               cpt;
 594         int               i;
 595         struct list_head *rn_list;
 596
 597         cpt = lnet_net_lock_current();
 598
 599         for (i = 0; i < LNET_REMOTE_NETS_HASH_SIZE; i++) {
 600                 rn_list = &the_lnet.ln_remote_nets_hash[i];
 601                 list_for_each(e1, rn_list) {
 602                         rnet = list_entry(e1, lnet_remotenet_t, lrn_list);
 603
 604                         list_for_each(e2, &rnet->lrn_routes) {
 605                                 route = list_entry(e2, lnet_route_t,
 606                                                    lr_list);
 607
 608                                 if (idx-- == 0) {
 609                                         *net      = rnet->lrn_net;
 610                                         *hops     = route->lr_hops;
 611                                         *priority = route->lr_priority;
 612                                         *gateway  = route->lr_gateway->lpni_nid;
 613                                         *alive    = lnet_is_route_alive(route);
 614                                         lnet_net_unlock(cpt);
 615                                         return 0;
 616                                 }
 617                         }
 618                 }
 619         }
 620
 621         lnet_net_unlock(cpt);
 622         return -ENOENT;
 623 }
 624
 625 void
 626 lnet_swap_pinginfo(struct lnet_ping_info *info)
 627 {
 628         int               i;
 629         struct lnet_ni_status *stat;
 630
 631         __swab32s(&info->pi_magic);
 632         __swab32s(&info->pi_features);
 633         __swab32s(&info->pi_pid);
 634         __swab32s(&info->pi_nnis);
 635         for (i = 0; i < info->pi_nnis && i < LNET_MAX_RTR_NIS; i++) {
 636                 stat = &info->pi_ni[i];
 637                 __swab64s(&stat->ns_nid);
 638                 __swab32s(&stat->ns_status);
 639         }
 640         return;
 641 }
 642
 643 /**
 644  * parse router-checker pinginfo, record number of down NIs for remote
 645  * networks on that router.
 646  */
 647 static void
 648 lnet_parse_rc_info(lnet_rc_data_t *rcd)
 649 {
 650         struct lnet_ping_info   *info = rcd->rcd_pinginfo;
 651         struct lnet_peer_ni     *gw   = rcd->rcd_gateway;
 652         lnet_route_t            *rte;
 653
 654         if (!gw->lpni_alive)
 655                 return;
 656
 657         if (info->pi_magic == __swab32(LNET_PROTO_PING_MAGIC))
 658                 lnet_swap_pinginfo(info);
 659
 660         /* NB always racing with network! */
 661         if (info->pi_magic != LNET_PROTO_PING_MAGIC) {
 662                 CDEBUG(D_NET, "%s: Unexpected magic %08x\n",
 663                        libcfs_nid2str(gw->lpni_nid), info->pi_magic);
 664                 gw->lpni_ping_feats = LNET_PING_FEAT_INVAL;
 665                 return;
 666         }
 667
 668         gw->lpni_ping_feats = info->pi_features;
 669         if ((gw->lpni_ping_feats & LNET_PING_FEAT_MASK) == 0) {
 670                 CDEBUG(D_NET, "%s: Unexpected features 0x%x\n",
 671                        libcfs_nid2str(gw->lpni_nid), gw->lpni_ping_feats);
 672                 return; /* nothing I can understand */
 673         }
 674
 675         if ((gw->lpni_ping_feats & LNET_PING_FEAT_NI_STATUS) == 0)
 676                 return; /* can't carry NI status info */
 677
 678         list_for_each_entry(rte, &gw->lpni_routes, lr_gwlist) {
 679                 int     down = 0;
 680                 int     up = 0;
 681                 int     i;
 682
 683                 if ((gw->lpni_ping_feats & LNET_PING_FEAT_RTE_DISABLED) != 0) {
 684                         rte->lr_downis = 1;
 685                         continue;
 686                 }
 687
 688                 for (i = 0; i < info->pi_nnis && i < LNET_MAX_RTR_NIS; i++) {
 689                         struct lnet_ni_status *stat = &info->pi_ni[i];
 690                         lnet_nid_t       nid = stat->ns_nid;
 691
 692                         if (nid == LNET_NID_ANY) {
 693                                 CDEBUG(D_NET, "%s: unexpected LNET_NID_ANY\n",
 694                                        libcfs_nid2str(gw->lpni_nid));
 695                                 gw->lpni_ping_feats = LNET_PING_FEAT_INVAL;
 696                                 return;
 697                         }
 698
 699                         if (LNET_NETTYP(LNET_NIDNET(nid)) == LOLND)
 700                                 continue;
 701
 702                         if (stat->ns_status == LNET_NI_STATUS_DOWN) {
 703                                 down++;
 704                                 continue;
 705                         }
 706
 707                         if (stat->ns_status == LNET_NI_STATUS_UP) {
 708                                 if (LNET_NIDNET(nid) == rte->lr_net) {
 709                                         up = 1;
 710                                         break;
 711                                 }
 712                                 continue;
 713                         }
 714
 715                         CDEBUG(D_NET, "%s: Unexpected status 0x%x\n",
 716                                libcfs_nid2str(gw->lpni_nid), stat->ns_status);
 717                         gw->lpni_ping_feats = LNET_PING_FEAT_INVAL;
 718                         return;
 719                 }
 720
 721                 if (up) { /* ignore downed NIs if NI for dest network is up */
 722                         rte->lr_downis = 0;
 723                         continue;
 724                 }
 725                 /* if @down is zero and this route is single-hop, it means
 726                  * we can't find NI for target network */
 727                 if (down == 0 && rte->lr_hops == 1)
 728                         down = 1;
 729
 730                 rte->lr_downis = down;
 731         }
 732 }
 733
 734 static void
 735 lnet_router_checker_event(lnet_event_t *event)
 736 {
 737         lnet_rc_data_t          *rcd = event->md.user_ptr;
 738         struct lnet_peer_ni     *lp;
 739
 740         LASSERT(rcd != NULL);
 741
 742         if (event->unlinked) {
 743                 LNetInvalidateHandle(&rcd->rcd_mdh);
 744                 return;
 745         }
 746
 747         LASSERT(event->type == LNET_EVENT_SEND ||
 748                 event->type == LNET_EVENT_REPLY);
 749
 750         lp = rcd->rcd_gateway;
 751         LASSERT(lp != NULL);
 752
 753          /* NB: it's called with holding lnet_res_lock, we have a few
 754           * places need to hold both locks at the same time, please take
 755           * care of lock ordering */
 756         lnet_net_lock(lp->lpni_cpt);
 757         if (!lnet_isrouter(lp) || lp->lpni_rcd != rcd) {
 758                 /* ignore if no longer a router or rcd is replaced */
 759                 goto out;
 760         }
 761
 762         if (event->type == LNET_EVENT_SEND) {
 763                 lp->lpni_ping_notsent = 0;
 764                 if (event->status == 0)
 765                         goto out;
 766         }
 767
 768         /* LNET_EVENT_REPLY */
 769         /* A successful REPLY means the router is up.  If _any_ comms
 770          * to the router fail I assume it's down (this will happen if
 771          * we ping alive routers to try to detect router death before
 772          * apps get burned). */
 773
 774         lnet_notify_locked(lp, 1, (event->status == 0), cfs_time_current());
 775         /* The router checker will wake up very shortly and do the
 776          * actual notification.
 777          * XXX If 'lp' stops being a router before then, it will still
 778          * have the notification pending!!! */
 779
 780         if (avoid_asym_router_failure && event->status == 0)
 781                 lnet_parse_rc_info(rcd);
 782
 783  out:
 784         lnet_net_unlock(lp->lpni_cpt);
 785 }
 786
 787 static void
 788 lnet_wait_known_routerstate(void)
 789 {
 790         struct lnet_peer_ni *rtr;
 791         struct list_head *entry;
 792         int all_known;
 793
 794         LASSERT(the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING);
 795
 796         for (;;) {
 797                 int cpt = lnet_net_lock_current();
 798
 799                 all_known = 1;
 800                 list_for_each(entry, &the_lnet.ln_routers) {
 801                         rtr = list_entry(entry, struct lnet_peer_ni,
 802                                          lpni_rtr_list);
 803
 804                         if (rtr->lpni_alive_count == 0) {
 805                                 all_known = 0;
 806                                 break;
 807                         }
 808                 }
 809
 810                 lnet_net_unlock(cpt);
 811
 812                 if (all_known)
 813                         return;
 814
 815                 set_current_state(TASK_UNINTERRUPTIBLE);
 816                 schedule_timeout(cfs_time_seconds(1));
 817         }
 818 }
 819
 820 void
 821 lnet_router_ni_update_locked(struct lnet_peer_ni *gw, __u32 net)
 822 {
 823         lnet_route_t *rte;
 824
 825         if ((gw->lpni_ping_feats & LNET_PING_FEAT_NI_STATUS) != 0) {
 826                 list_for_each_entry(rte, &gw->lpni_routes, lr_gwlist) {
 827                         if (rte->lr_net == net) {
 828                                 rte->lr_downis = 0;
 829                                 break;
 830                         }
 831                 }
 832         }
 833 }
 834
 835 static void
 836 lnet_update_ni_status_locked(void)
 837 {
 838         lnet_ni_t       *ni = NULL;
 839         time64_t        now;
 840         int             timeout;
 841
 842         LASSERT(the_lnet.ln_routing);
 843
 844         timeout = router_ping_timeout +
 845                   MAX(live_router_check_interval, dead_router_check_interval);
 846
 847         now = ktime_get_real_seconds();
 848         while ((ni = lnet_get_next_ni_locked(NULL, ni))) {
 849                 if (ni->ni_net->net_lnd->lnd_type == LOLND)
 850                         continue;
 851
 852                 if (now < ni->ni_last_alive + timeout)
 853                         continue;
 854
 855                 lnet_ni_lock(ni);
 856                 /* re-check with lock */
 857                 if (now < ni->ni_last_alive + timeout) {
 858                         lnet_ni_unlock(ni);
 859                         continue;
 860                 }
 861
 862                 LASSERT(ni->ni_status != NULL);
 863
 864                 if (ni->ni_status->ns_status != LNET_NI_STATUS_DOWN) {
 865                         CDEBUG(D_NET, "NI(%s:%d) status changed to down\n",
 866                                libcfs_nid2str(ni->ni_nid), timeout);
 867                         /* NB: so far, this is the only place to set
 868                          * NI status to "down" */
 869                         ni->ni_status->ns_status = LNET_NI_STATUS_DOWN;
 870                 }
 871                 lnet_ni_unlock(ni);
 872         }
 873 }
 874
 875 static void
 876 lnet_destroy_rc_data(lnet_rc_data_t *rcd)
 877 {
 878         LASSERT(list_empty(&rcd->rcd_list));
 879         /* detached from network */
 880         LASSERT(LNetHandleIsInvalid(rcd->rcd_mdh));
 881
 882         if (rcd->rcd_gateway != NULL) {
 883                 int cpt = rcd->rcd_gateway->lpni_cpt;
 884
 885                 lnet_net_lock(cpt);
 886                 lnet_peer_ni_decref_locked(rcd->rcd_gateway);
 887                 lnet_net_unlock(cpt);
 888         }
 889
 890         if (rcd->rcd_pinginfo != NULL)
 891                 LIBCFS_FREE(rcd->rcd_pinginfo, LNET_PINGINFO_SIZE);
 892
 893         LIBCFS_FREE(rcd, sizeof(*rcd));
 894 }
 895
 896 static lnet_rc_data_t *
 897 lnet_create_rc_data_locked(struct lnet_peer_ni *gateway)
 898 {
 899         lnet_rc_data_t          *rcd = NULL;
 900         struct lnet_ping_info   *pi;
 901         int                     rc;
 902         int                     i;
 903
 904         lnet_net_unlock(gateway->lpni_cpt);
 905
 906         LIBCFS_ALLOC(rcd, sizeof(*rcd));
 907         if (rcd == NULL)
 908                 goto out;
 909
 910         LNetInvalidateHandle(&rcd->rcd_mdh);
 911         INIT_LIST_HEAD(&rcd->rcd_list);
 912
 913         LIBCFS_ALLOC(pi, LNET_PINGINFO_SIZE);
 914         if (pi == NULL)
 915                 goto out;
 916
 917         for (i = 0; i < LNET_MAX_RTR_NIS; i++) {
 918                 pi->pi_ni[i].ns_nid = LNET_NID_ANY;
 919                 pi->pi_ni[i].ns_status = LNET_NI_STATUS_INVALID;
 920         }
 921         rcd->rcd_pinginfo = pi;
 922
 923         LASSERT(!LNetHandleIsInvalid(the_lnet.ln_rc_eqh));
 924         rc = LNetMDBind((lnet_md_t){.start     = pi,
 925                                     .user_ptr  = rcd,
 926                                     .length    = LNET_PINGINFO_SIZE,
 927                                     .threshold = LNET_MD_THRESH_INF,
 928                                     .options   = LNET_MD_TRUNCATE,
 929                                     .eq_handle = the_lnet.ln_rc_eqh},
 930                         LNET_UNLINK,
 931                         &rcd->rcd_mdh);
 932         if (rc < 0) {
 933                 CERROR("Can't bind MD: %d\n", rc);
 934                 goto out;
 935         }
 936         LASSERT(rc == 0);
 937
 938         lnet_net_lock(gateway->lpni_cpt);
 939         /* router table changed or someone has created rcd for this gateway */
 940         if (!lnet_isrouter(gateway) || gateway->lpni_rcd != NULL) {
 941                 lnet_net_unlock(gateway->lpni_cpt);
 942                 goto out;
 943         }
 944
 945         lnet_peer_ni_addref_locked(gateway);
 946         rcd->rcd_gateway = gateway;
 947         gateway->lpni_rcd = rcd;
 948         gateway->lpni_ping_notsent = 0;
 949
 950         return rcd;
 951
 952 out:
 953         if (rcd != NULL) {
 954                 if (!LNetHandleIsInvalid(rcd->rcd_mdh)) {
 955                         rc = LNetMDUnlink(rcd->rcd_mdh);
 956                         LASSERT(rc == 0);
 957                 }
 958                 lnet_destroy_rc_data(rcd);
 959         }
 960
 961         lnet_net_lock(gateway->lpni_cpt);
 962         return gateway->lpni_rcd;
 963 }
 964
 965 static int
 966 lnet_router_check_interval (struct lnet_peer_ni *rtr)
 967 {
 968         int secs;
 969
 970         secs = rtr->lpni_alive ? live_router_check_interval :
 971                                dead_router_check_interval;
 972         if (secs < 0)
 973                 secs = 0;
 974
 975         return secs;
 976 }
 977
 978 static void
 979 lnet_ping_router_locked (struct lnet_peer_ni *rtr)
 980 {
 981         lnet_rc_data_t *rcd = NULL;
 982         cfs_time_t      now = cfs_time_current();
 983         int             secs;
 984         struct lnet_ni  *ni;
 985
 986         lnet_peer_ni_addref_locked(rtr);
 987
 988         if (rtr->lpni_ping_deadline != 0 && /* ping timed out? */
 989             cfs_time_after(now, rtr->lpni_ping_deadline))
 990                 lnet_notify_locked(rtr, 1, 0, now);
 991
 992         /* Run any outstanding notifications */
 993         ni = lnet_get_next_ni_locked(rtr->lpni_net, NULL);
 994         lnet_ni_notify_locked(ni, rtr);
 995
 996         if (!lnet_isrouter(rtr) ||
 997             the_lnet.ln_rc_state != LNET_RC_STATE_RUNNING) {
 998                 /* router table changed or router checker is shutting down */
 999                 lnet_peer_ni_decref_locked(rtr);
1000                 return;
1001         }
1002
1003         rcd = rtr->lpni_rcd != NULL ?
1004               rtr->lpni_rcd : lnet_create_rc_data_locked(rtr);
1005
1006         if (rcd == NULL)
1007                 return;
1008
1009         secs = lnet_router_check_interval(rtr);
1010
1011         CDEBUG(D_NET,
1012                "rtr %s %d: deadline %lu ping_notsent %d alive %d "
1013                "alive_count %d lpni_ping_timestamp %lu\n",
1014                libcfs_nid2str(rtr->lpni_nid), secs,
1015                rtr->lpni_ping_deadline, rtr->lpni_ping_notsent,
1016                rtr->lpni_alive, rtr->lpni_alive_count, rtr->lpni_ping_timestamp);
1017
1018         if (secs != 0 && !rtr->lpni_ping_notsent &&
1019             cfs_time_after(now, cfs_time_add(rtr->lpni_ping_timestamp,
1020                                              cfs_time_seconds(secs)))) {
1021                 int               rc;
1022                 lnet_process_id_t id;
1023                 lnet_handle_md_t  mdh;
1024
1025                 id.nid = rtr->lpni_nid;
1026                 id.pid = LNET_PID_LUSTRE;
1027                 CDEBUG(D_NET, "Check: %s\n", libcfs_id2str(id));
1028
1029                 rtr->lpni_ping_notsent   = 1;
1030                 rtr->lpni_ping_timestamp = now;
1031
1032                 mdh = rcd->rcd_mdh;
1033
1034                 if (rtr->lpni_ping_deadline == 0) {
1035                         rtr->lpni_ping_deadline =
1036                                 cfs_time_shift(router_ping_timeout);
1037                 }
1038
1039                 lnet_net_unlock(rtr->lpni_cpt);
1040
1041                 rc = LNetGet(LNET_NID_ANY, mdh, id, LNET_RESERVED_PORTAL,
1042                              LNET_PROTO_PING_MATCHBITS, 0);
1043
1044                 lnet_net_lock(rtr->lpni_cpt);
1045                 if (rc != 0)
1046                         rtr->lpni_ping_notsent = 0; /* no event pending */
1047         }
1048
1049         lnet_peer_ni_decref_locked(rtr);
1050         return;
1051 }
1052
1053 int
1054 lnet_router_checker_start(void)
1055 {
1056         int                     rc;
1057         int                     eqsz = 0;
1058         struct task_struct     *task;
1059
1060         LASSERT(the_lnet.ln_rc_state == LNET_RC_STATE_SHUTDOWN);
1061
1062         if (check_routers_before_use &&
1063             dead_router_check_interval <= 0) {
1064                 LCONSOLE_ERROR_MSG(0x10a, "'dead_router_check_interval' must be"
1065                                    " set if 'check_routers_before_use' is set"
1066                                    "\n");
1067                 return -EINVAL;
1068         }
1069
1070         sema_init(&the_lnet.ln_rc_signal, 0);
1071
1072         rc = LNetEQAlloc(0, lnet_router_checker_event, &the_lnet.ln_rc_eqh);
1073         if (rc != 0) {
1074                 CERROR("Can't allocate EQ(%d): %d\n", eqsz, rc);
1075                 return -ENOMEM;
1076         }
1077
1078         the_lnet.ln_rc_state = LNET_RC_STATE_RUNNING;
1079         task = kthread_run(lnet_router_checker, NULL, "router_checker");
1080         if (IS_ERR(task)) {
1081                 rc = PTR_ERR(task);
1082                 CERROR("Can't start router checker thread: %d\n", rc);
1083                 /* block until event callback signals exit */
1084                 down(&the_lnet.ln_rc_signal);
1085                 rc = LNetEQFree(the_lnet.ln_rc_eqh);
1086                 LASSERT(rc == 0);
1087                 the_lnet.ln_rc_state = LNET_RC_STATE_SHUTDOWN;
1088                 return -ENOMEM;
1089         }
1090
1091         if (check_routers_before_use) {
1092                 /* Note that a helpful side-effect of pinging all known routers
1093                  * at startup is that it makes them drop stale connections they
1094                  * may have to a previous instance of me. */
1095                 lnet_wait_known_routerstate();
1096         }
1097
1098         return 0;
1099 }
1100
1101 void
1102 lnet_router_checker_stop (void)
1103 {
1104         int rc;
1105
1106         if (the_lnet.ln_rc_state == LNET_RC_STATE_SHUTDOWN)
1107                 return;
1108
1109         LASSERT (the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING);
1110         the_lnet.ln_rc_state = LNET_RC_STATE_STOPPING;
1111         /* wakeup the RC thread if it's sleeping */
1112         wake_up(&the_lnet.ln_rc_waitq);
1113
1114         /* block until event callback signals exit */
1115         down(&the_lnet.ln_rc_signal);
1116         LASSERT(the_lnet.ln_rc_state == LNET_RC_STATE_SHUTDOWN);
1117
1118         rc = LNetEQFree(the_lnet.ln_rc_eqh);
1119         LASSERT(rc == 0);
1120         return;
1121 }
1122
1123 static void
1124 lnet_prune_rc_data(int wait_unlink)
1125 {
1126         lnet_rc_data_t          *rcd;
1127         lnet_rc_data_t          *tmp;
1128         struct lnet_peer_ni     *lp;
1129         struct list_head         head;
1130         int                      i = 2;
1131
1132         if (likely(the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING &&
1133                    list_empty(&the_lnet.ln_rcd_deathrow) &&
1134                    list_empty(&the_lnet.ln_rcd_zombie)))
1135                 return;
1136
1137         INIT_LIST_HEAD(&head);
1138
1139         lnet_net_lock(LNET_LOCK_EX);
1140
1141         if (the_lnet.ln_rc_state != LNET_RC_STATE_RUNNING) {
1142                 /* router checker is stopping, prune all */
1143                 list_for_each_entry(lp, &the_lnet.ln_routers,
1144                                     lpni_rtr_list) {
1145                         if (lp->lpni_rcd == NULL)
1146                                 continue;
1147
1148                         LASSERT(list_empty(&lp->lpni_rcd->rcd_list));
1149                         list_add(&lp->lpni_rcd->rcd_list,
1150                                  &the_lnet.ln_rcd_deathrow);
1151                         lp->lpni_rcd = NULL;
1152                 }
1153         }
1154
1155         /* unlink all RCDs on deathrow list */
1156         list_splice_init(&the_lnet.ln_rcd_deathrow, &head);
1157
1158         if (!list_empty(&head)) {
1159                 lnet_net_unlock(LNET_LOCK_EX);
1160
1161                 list_for_each_entry(rcd, &head, rcd_list)
1162                         LNetMDUnlink(rcd->rcd_mdh);
1163
1164                 lnet_net_lock(LNET_LOCK_EX);
1165         }
1166
1167         list_splice_init(&head, &the_lnet.ln_rcd_zombie);
1168
1169         /* release all zombie RCDs */
1170         while (!list_empty(&the_lnet.ln_rcd_zombie)) {
1171                 list_for_each_entry_safe(rcd, tmp, &the_lnet.ln_rcd_zombie,
1172                                          rcd_list) {
1173                         if (LNetHandleIsInvalid(rcd->rcd_mdh))
1174                                 list_move(&rcd->rcd_list, &head);
1175                 }
1176
1177                 wait_unlink = wait_unlink &&
1178                               !list_empty(&the_lnet.ln_rcd_zombie);
1179
1180                 lnet_net_unlock(LNET_LOCK_EX);
1181
1182                 while (!list_empty(&head)) {
1183                         rcd = list_entry(head.next,
1184                                          lnet_rc_data_t, rcd_list);
1185                         list_del_init(&rcd->rcd_list);
1186                         lnet_destroy_rc_data(rcd);
1187                 }
1188
1189                 if (!wait_unlink)
1190                         return;
1191
1192                 i++;
1193                 CDEBUG(((i & (-i)) == i) ? D_WARNING : D_NET,
1194                        "Waiting for rc buffers to unlink\n");
1195                 set_current_state(TASK_UNINTERRUPTIBLE);
1196                 schedule_timeout(cfs_time_seconds(1) / 4);
1197
1198                 lnet_net_lock(LNET_LOCK_EX);
1199         }
1200
1201         lnet_net_unlock(LNET_LOCK_EX);
1202 }
1203
1204 /*
1205  * This function is called to check if the RC should block indefinitely.
1206  * It's called from lnet_router_checker() as well as being passed to
1207  * wait_event_interruptible() to avoid the lost wake_up problem.
1208  *
1209  * When it's called from wait_event_interruptible() it is necessary to
1210  * also not sleep if the rc state is not running to avoid a deadlock
1211  * when the system is shutting down
1212  */
1213 static inline bool
1214 lnet_router_checker_active(void)
1215 {
1216         if (the_lnet.ln_rc_state != LNET_RC_STATE_RUNNING)
1217                 return true;
1218
1219         /* Router Checker thread needs to run when routing is enabled in
1220          * order to call lnet_update_ni_status_locked() */
1221         if (the_lnet.ln_routing)
1222                 return true;
1223
1224         return !list_empty(&the_lnet.ln_routers) &&
1225                 (live_router_check_interval > 0 ||
1226                  dead_router_check_interval > 0);
1227 }
1228
1229 static int
1230 lnet_router_checker(void *arg)
1231 {
1232         struct lnet_peer_ni *rtr;
1233         struct list_head *entry;
1234
1235         cfs_block_allsigs();
1236
1237         while (the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING) {
1238                 __u64   version;
1239                 int     cpt;
1240                 int     cpt2;
1241
1242                 cpt = lnet_net_lock_current();
1243 rescan:
1244                 version = the_lnet.ln_routers_version;
1245
1246                 list_for_each(entry, &the_lnet.ln_routers) {
1247                         rtr = list_entry(entry, struct lnet_peer_ni,
1248                                          lpni_rtr_list);
1249
1250                         cpt2 = rtr->lpni_cpt;
1251                         if (cpt != cpt2) {
1252                                 lnet_net_unlock(cpt);
1253                                 cpt = cpt2;
1254                                 lnet_net_lock(cpt);
1255                                 /* the routers list has changed */
1256                                 if (version != the_lnet.ln_routers_version)
1257                                         goto rescan;
1258                         }
1259
1260                         lnet_ping_router_locked(rtr);
1261
1262                         /* NB dropped lock */
1263                         if (version != the_lnet.ln_routers_version) {
1264                                 /* the routers list has changed */
1265                                 goto rescan;
1266                         }
1267                 }
1268
1269                 if (the_lnet.ln_routing)
1270                         lnet_update_ni_status_locked();
1271
1272                 lnet_net_unlock(cpt);
1273
1274                 lnet_prune_rc_data(0); /* don't wait for UNLINK */
1275
1276                 /* Call schedule_timeout() here always adds 1 to load average
1277                  * because kernel counts # active tasks as nr_running
1278                  * + nr_uninterruptible. */
1279                 /* if there are any routes then wakeup every second.  If
1280                  * there are no routes then sleep indefinitely until woken
1281                  * up by a user adding a route */
1282                 if (!lnet_router_checker_active())
1283                         wait_event_interruptible(the_lnet.ln_rc_waitq,
1284                                                  lnet_router_checker_active());
1285                 else
1286                         wait_event_interruptible_timeout(the_lnet.ln_rc_waitq,
1287                                                          false,
1288                                                          cfs_time_seconds(1));
1289         }
1290
1291         lnet_prune_rc_data(1); /* wait for UNLINK */
1292
1293         the_lnet.ln_rc_state = LNET_RC_STATE_SHUTDOWN;
1294         up(&the_lnet.ln_rc_signal);
1295         /* The unlink event callback will signal final completion */
1296         return 0;
1297 }
1298
1299 void
1300 lnet_destroy_rtrbuf(lnet_rtrbuf_t *rb, int npages)
1301 {
1302         int sz = offsetof(lnet_rtrbuf_t, rb_kiov[npages]);
1303
1304         while (--npages >= 0)
1305                 __free_page(rb->rb_kiov[npages].kiov_page);
1306
1307         LIBCFS_FREE(rb, sz);
1308 }
1309
1310 static lnet_rtrbuf_t *
1311 lnet_new_rtrbuf(lnet_rtrbufpool_t *rbp, int cpt)
1312 {
1313         int            npages = rbp->rbp_npages;
1314         int            sz = offsetof(lnet_rtrbuf_t, rb_kiov[npages]);
1315         struct page   *page;
1316         lnet_rtrbuf_t *rb;
1317         int            i;
1318
1319         LIBCFS_CPT_ALLOC(rb, lnet_cpt_table(), cpt, sz);
1320         if (rb == NULL)
1321                 return NULL;
1322
1323         rb->rb_pool = rbp;
1324
1325         for (i = 0; i < npages; i++) {
1326                 page = cfs_page_cpt_alloc(lnet_cpt_table(), cpt,
1327                                           GFP_KERNEL | __GFP_ZERO);
1328                 if (page == NULL) {
1329                         while (--i >= 0)
1330                                 __free_page(rb->rb_kiov[i].kiov_page);
1331
1332                         LIBCFS_FREE(rb, sz);
1333                         return NULL;
1334                 }
1335
1336                 rb->rb_kiov[i].kiov_len = PAGE_SIZE;
1337                 rb->rb_kiov[i].kiov_offset = 0;
1338                 rb->rb_kiov[i].kiov_page = page;
1339         }
1340
1341         return rb;
1342 }
1343
1344 static void
1345 lnet_rtrpool_free_bufs(lnet_rtrbufpool_t *rbp, int cpt)
1346 {
1347         int              npages = rbp->rbp_npages;
1348         lnet_rtrbuf_t    *rb;
1349         struct list_head tmp;
1350
1351         if (rbp->rbp_nbuffers == 0) /* not initialized or already freed */
1352                 return;
1353
1354         INIT_LIST_HEAD(&tmp);
1355
1356         lnet_net_lock(cpt);
1357         lnet_drop_routed_msgs_locked(&rbp->rbp_msgs, cpt);
1358         list_splice_init(&rbp->rbp_bufs, &tmp);
1359         rbp->rbp_req_nbuffers = 0;
1360         rbp->rbp_nbuffers = rbp->rbp_credits = 0;
1361         rbp->rbp_mincredits = 0;
1362         lnet_net_unlock(cpt);
1363
1364         /* Free buffers on the free list. */
1365         while (!list_empty(&tmp)) {
1366                 rb = list_entry(tmp.next, lnet_rtrbuf_t, rb_list);
1367                 list_del(&rb->rb_list);
1368                 lnet_destroy_rtrbuf(rb, npages);
1369         }
1370 }
1371
1372 static int
1373 lnet_rtrpool_adjust_bufs(lnet_rtrbufpool_t *rbp, int nbufs, int cpt)
1374 {
1375         struct list_head rb_list;
1376         lnet_rtrbuf_t   *rb;
1377         int             num_rb;
1378         int             num_buffers = 0;
1379         int             old_req_nbufs;
1380         int             npages = rbp->rbp_npages;
1381
1382         lnet_net_lock(cpt);
1383         /* If we are called for less buffers than already in the pool, we
1384          * just lower the req_nbuffers number and excess buffers will be
1385          * thrown away as they are returned to the free list.  Credits
1386          * then get adjusted as well.
1387          * If we already have enough buffers allocated to serve the
1388          * increase requested, then we can treat that the same way as we
1389          * do the decrease. */
1390         num_rb = nbufs - rbp->rbp_nbuffers;
1391         if (nbufs <= rbp->rbp_req_nbuffers || num_rb <= 0) {
1392                 rbp->rbp_req_nbuffers = nbufs;
1393                 lnet_net_unlock(cpt);
1394                 return 0;
1395         }
1396         /* store the older value of rbp_req_nbuffers and then set it to
1397          * the new request to prevent lnet_return_rx_credits_locked() from
1398          * freeing buffers that we need to keep around */
1399         old_req_nbufs = rbp->rbp_req_nbuffers;
1400         rbp->rbp_req_nbuffers = nbufs;
1401         lnet_net_unlock(cpt);
1402
1403         INIT_LIST_HEAD(&rb_list);
1404
1405         /* allocate the buffers on a local list first.  If all buffers are
1406          * allocated successfully then join this list to the rbp buffer
1407          * list.  If not then free all allocated buffers. */
1408         while (num_rb-- > 0) {
1409                 rb = lnet_new_rtrbuf(rbp, cpt);
1410                 if (rb == NULL) {
1411                         CERROR("Failed to allocate %d route bufs of %d pages\n",
1412                                nbufs, npages);
1413
1414                         lnet_net_lock(cpt);
1415                         rbp->rbp_req_nbuffers = old_req_nbufs;
1416                         lnet_net_unlock(cpt);
1417
1418                         goto failed;
1419                 }
1420
1421                 list_add(&rb->rb_list, &rb_list);
1422                 num_buffers++;
1423         }
1424
1425         lnet_net_lock(cpt);
1426
1427         list_splice_tail(&rb_list, &rbp->rbp_bufs);
1428         rbp->rbp_nbuffers += num_buffers;
1429         rbp->rbp_credits += num_buffers;
1430         rbp->rbp_mincredits = rbp->rbp_credits;
1431         /* We need to schedule blocked msg using the newly
1432          * added buffers. */
1433         while (!list_empty(&rbp->rbp_bufs) &&
1434                !list_empty(&rbp->rbp_msgs))
1435                 lnet_schedule_blocked_locked(rbp);
1436
1437         lnet_net_unlock(cpt);
1438
1439         return 0;
1440
1441 failed:
1442         while (!list_empty(&rb_list)) {
1443                 rb = list_entry(rb_list.next, lnet_rtrbuf_t, rb_list);
1444                 list_del(&rb->rb_list);
1445                 lnet_destroy_rtrbuf(rb, npages);
1446         }
1447
1448         return -ENOMEM;
1449 }
1450
1451 static void
1452 lnet_rtrpool_init(lnet_rtrbufpool_t *rbp, int npages)
1453 {
1454         INIT_LIST_HEAD(&rbp->rbp_msgs);
1455         INIT_LIST_HEAD(&rbp->rbp_bufs);
1456
1457         rbp->rbp_npages = npages;
1458         rbp->rbp_credits = 0;
1459         rbp->rbp_mincredits = 0;
1460 }
1461
1462 void
1463 lnet_rtrpools_free(int keep_pools)
1464 {
1465         lnet_rtrbufpool_t *rtrp;
1466         int               i;
1467
1468         if (the_lnet.ln_rtrpools == NULL) /* uninitialized or freed */
1469                 return;
1470
1471         cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
1472                 lnet_rtrpool_free_bufs(&rtrp[LNET_TINY_BUF_IDX], i);
1473                 lnet_rtrpool_free_bufs(&rtrp[LNET_SMALL_BUF_IDX], i);
1474                 lnet_rtrpool_free_bufs(&rtrp[LNET_LARGE_BUF_IDX], i);
1475         }
1476
1477         if (!keep_pools) {
1478                 cfs_percpt_free(the_lnet.ln_rtrpools);
1479                 the_lnet.ln_rtrpools = NULL;
1480         }
1481 }
1482
1483 static int
1484 lnet_nrb_tiny_calculate(void)
1485 {
1486         int     nrbs = LNET_NRB_TINY;
1487
1488         if (tiny_router_buffers < 0) {
1489                 LCONSOLE_ERROR_MSG(0x10c,
1490                                    "tiny_router_buffers=%d invalid when "
1491                                    "routing enabled\n", tiny_router_buffers);
1492                 return -EINVAL;
1493         }
1494
1495         if (tiny_router_buffers > 0)
1496                 nrbs = tiny_router_buffers;
1497
1498         nrbs /= LNET_CPT_NUMBER;
1499         return max(nrbs, LNET_NRB_TINY_MIN);
1500 }
1501
1502 static int
1503 lnet_nrb_small_calculate(void)
1504 {
1505         int     nrbs = LNET_NRB_SMALL;
1506
1507         if (small_router_buffers < 0) {
1508                 LCONSOLE_ERROR_MSG(0x10c,
1509                                    "small_router_buffers=%d invalid when "
1510                                    "routing enabled\n", small_router_buffers);
1511                 return -EINVAL;
1512         }
1513
1514         if (small_router_buffers > 0)
1515                 nrbs = small_router_buffers;
1516
1517         nrbs /= LNET_CPT_NUMBER;
1518         return max(nrbs, LNET_NRB_SMALL_MIN);
1519 }
1520
1521 static int
1522 lnet_nrb_large_calculate(void)
1523 {
1524         int     nrbs = LNET_NRB_LARGE;
1525
1526         if (large_router_buffers < 0) {
1527                 LCONSOLE_ERROR_MSG(0x10c,
1528                                    "large_router_buffers=%d invalid when "
1529                                    "routing enabled\n", large_router_buffers);
1530                 return -EINVAL;
1531         }
1532
1533         if (large_router_buffers > 0)
1534                 nrbs = large_router_buffers;
1535
1536         nrbs /= LNET_CPT_NUMBER;
1537         return max(nrbs, LNET_NRB_LARGE_MIN);
1538 }
1539
1540 int
1541 lnet_rtrpools_alloc(int im_a_router)
1542 {
1543         lnet_rtrbufpool_t *rtrp;
1544         int     nrb_tiny;
1545         int     nrb_small;
1546         int     nrb_large;
1547         int     rc;
1548         int     i;
1549
1550         if (!strcmp(forwarding, "")) {
1551                 /* not set either way */
1552                 if (!im_a_router)
1553                         return 0;
1554         } else if (!strcmp(forwarding, "disabled")) {
1555                 /* explicitly disabled */
1556                 return 0;
1557         } else if (!strcmp(forwarding, "enabled")) {
1558                 /* explicitly enabled */
1559         } else {
1560                 LCONSOLE_ERROR_MSG(0x10b, "'forwarding' not set to either "
1561                                    "'enabled' or 'disabled'\n");
1562                 return -EINVAL;
1563         }
1564
1565         nrb_tiny = lnet_nrb_tiny_calculate();
1566         if (nrb_tiny < 0)
1567                 return -EINVAL;
1568
1569         nrb_small = lnet_nrb_small_calculate();
1570         if (nrb_small < 0)
1571                 return -EINVAL;
1572
1573         nrb_large = lnet_nrb_large_calculate();
1574         if (nrb_large < 0)
1575                 return -EINVAL;
1576
1577         the_lnet.ln_rtrpools = cfs_percpt_alloc(lnet_cpt_table(),
1578                                                 LNET_NRBPOOLS *
1579                                                 sizeof(lnet_rtrbufpool_t));
1580         if (the_lnet.ln_rtrpools == NULL) {
1581                 LCONSOLE_ERROR_MSG(0x10c,
1582                                    "Failed to initialize router buffe pool\n");
1583                 return -ENOMEM;
1584         }
1585
1586         cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
1587                 lnet_rtrpool_init(&rtrp[LNET_TINY_BUF_IDX], 0);
1588                 rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_TINY_BUF_IDX],
1589                                               nrb_tiny, i);
1590                 if (rc != 0)
1591                         goto failed;
1592
1593                 lnet_rtrpool_init(&rtrp[LNET_SMALL_BUF_IDX],
1594                                   LNET_NRB_SMALL_PAGES);
1595                 rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_SMALL_BUF_IDX],
1596                                               nrb_small, i);
1597                 if (rc != 0)
1598                         goto failed;
1599
1600                 lnet_rtrpool_init(&rtrp[LNET_LARGE_BUF_IDX],
1601                                   LNET_NRB_LARGE_PAGES);
1602                 rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_LARGE_BUF_IDX],
1603                                               nrb_large, i);
1604                 if (rc != 0)
1605                         goto failed;
1606         }
1607
1608         lnet_net_lock(LNET_LOCK_EX);
1609         the_lnet.ln_routing = 1;
1610         lnet_net_unlock(LNET_LOCK_EX);
1611         return 0;
1612
1613  failed:
1614         lnet_rtrpools_free(0);
1615         return rc;
1616 }
1617
1618 static int
1619 lnet_rtrpools_adjust_helper(int tiny, int small, int large)
1620 {
1621         int nrb = 0;
1622         int rc = 0;
1623         int i;
1624         lnet_rtrbufpool_t *rtrp;
1625
1626         /* If the provided values for each buffer pool are different than the
1627          * configured values, we need to take action. */
1628         if (tiny >= 0) {
1629                 tiny_router_buffers = tiny;
1630                 nrb = lnet_nrb_tiny_calculate();
1631                 cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
1632                         rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_TINY_BUF_IDX],
1633                                                       nrb, i);
1634                         if (rc != 0)
1635                                 return rc;
1636                 }
1637         }
1638         if (small >= 0) {
1639                 small_router_buffers = small;
1640                 nrb = lnet_nrb_small_calculate();
1641                 cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
1642                         rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_SMALL_BUF_IDX],
1643                                                       nrb, i);
1644                         if (rc != 0)
1645                                 return rc;
1646                 }
1647         }
1648         if (large >= 0) {
1649                 large_router_buffers = large;
1650                 nrb = lnet_nrb_large_calculate();
1651                 cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
1652                         rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_LARGE_BUF_IDX],
1653                                                       nrb, i);
1654                         if (rc != 0)
1655                                 return rc;
1656                 }
1657         }
1658
1659         return 0;
1660 }
1661
1662 int
1663 lnet_rtrpools_adjust(int tiny, int small, int large)
1664 {
1665         /* this function doesn't revert the changes if adding new buffers
1666          * failed.  It's up to the user space caller to revert the
1667          * changes. */
1668
1669         if (!the_lnet.ln_routing)
1670                 return 0;
1671
1672         return lnet_rtrpools_adjust_helper(tiny, small, large);
1673 }
1674
1675 int
1676 lnet_rtrpools_enable(void)
1677 {
1678         int rc = 0;
1679
1680         if (the_lnet.ln_routing)
1681                 return 0;
1682
1683         if (the_lnet.ln_rtrpools == NULL)
1684                 /* If routing is turned off, and we have never
1685                  * initialized the pools before, just call the
1686                  * standard buffer pool allocation routine as
1687                  * if we are just configuring this for the first
1688                  * time. */
1689                 rc = lnet_rtrpools_alloc(1);
1690         else
1691                 rc = lnet_rtrpools_adjust_helper(0, 0, 0);
1692         if (rc != 0)
1693                 return rc;
1694
1695         lnet_net_lock(LNET_LOCK_EX);
1696         the_lnet.ln_routing = 1;
1697
1698         the_lnet.ln_ping_info->pi_features &= ~LNET_PING_FEAT_RTE_DISABLED;
1699         lnet_net_unlock(LNET_LOCK_EX);
1700
1701         return rc;
1702 }
1703
1704 void
1705 lnet_rtrpools_disable(void)
1706 {
1707         if (!the_lnet.ln_routing)
1708                 return;
1709
1710         lnet_net_lock(LNET_LOCK_EX);
1711         the_lnet.ln_routing = 0;
1712         the_lnet.ln_ping_info->pi_features |= LNET_PING_FEAT_RTE_DISABLED;
1713
1714         tiny_router_buffers = 0;
1715         small_router_buffers = 0;
1716         large_router_buffers = 0;
1717         lnet_net_unlock(LNET_LOCK_EX);
1718         lnet_rtrpools_free(1);
1719 }
1720
1721 int
1722 lnet_notify(lnet_ni_t *ni, lnet_nid_t nid, int alive, cfs_time_t when)
1723 {
1724         struct lnet_peer_ni     *lp = NULL;
1725         cfs_time_t              now = cfs_time_current();
1726         int                     cpt = lnet_cpt_of_nid(nid, ni);
1727
1728         LASSERT (!in_interrupt ());
1729
1730         CDEBUG (D_NET, "%s notifying %s: %s\n",
1731                 (ni == NULL) ? "userspace" : libcfs_nid2str(ni->ni_nid),
1732                 libcfs_nid2str(nid),
1733                 alive ? "up" : "down");
1734
1735         if (ni != NULL &&
1736             LNET_NIDNET(ni->ni_nid) != LNET_NIDNET(nid)) {
1737                 CWARN("Ignoring notification of %s %s by %s (different net)\n",
1738                       libcfs_nid2str(nid), alive ? "birth" : "death",
1739                       libcfs_nid2str(ni->ni_nid));
1740                 return -EINVAL;
1741         }
1742
1743         /* can't do predictions... */
1744         if (cfs_time_after(when, now)) {
1745                 CWARN("Ignoring prediction from %s of %s %s "
1746                       "%ld seconds in the future\n",
1747                       (ni == NULL) ? "userspace" : libcfs_nid2str(ni->ni_nid),
1748                       libcfs_nid2str(nid), alive ? "up" : "down",
1749                       cfs_duration_sec(cfs_time_sub(when, now)));
1750                 return -EINVAL;
1751         }
1752
1753         if (ni != NULL && !alive &&             /* LND telling me she's down */
1754             !auto_down) {                       /* auto-down disabled */
1755                 CDEBUG(D_NET, "Auto-down disabled\n");
1756                 return 0;
1757         }
1758
1759         lnet_net_lock(cpt);
1760
1761         if (the_lnet.ln_shutdown) {
1762                 lnet_net_unlock(cpt);
1763                 return -ESHUTDOWN;
1764         }
1765
1766         lp = lnet_find_peer_ni_locked(nid, cpt);
1767         if (lp == NULL) {
1768                 /* nid not found */
1769                 lnet_net_unlock(cpt);
1770                 CDEBUG(D_NET, "%s not found\n", libcfs_nid2str(nid));
1771                 return 0;
1772         }
1773
1774         /* We can't fully trust LND on reporting exact peer last_alive
1775          * if he notifies us about dead peer. For example ksocklnd can
1776          * call us with when == _time_when_the_node_was_booted_ if
1777          * no connections were successfully established */
1778         if (ni != NULL && !alive && when < lp->lpni_last_alive)
1779                 when = lp->lpni_last_alive;
1780
1781         lnet_notify_locked(lp, ni == NULL, alive, when);
1782
1783         if (ni != NULL)
1784                 lnet_ni_notify_locked(ni, lp);
1785
1786         lnet_peer_ni_decref_locked(lp);
1787
1788         lnet_net_unlock(cpt);
1789         return 0;
1790 }
1791 EXPORT_SYMBOL(lnet_notify);