lnet/lnet/peer.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2012, 2017, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  * Lustre is a trademark of Sun Microsystems, Inc.
  31  *
  32  * lnet/lnet/peer.c
  33  */
  34
  35 #define DEBUG_SUBSYSTEM S_LNET
  36
  37 #include <linux/sched.h>
  38 #ifdef HAVE_SCHED_HEADERS
  39 #include <linux/sched/signal.h>
  40 #endif
  41 #include <linux/uaccess.h>
  42
  43 #include <lnet/lib-lnet.h>
  44 #include <uapi/linux/lnet/lnet-dlc.h>
  45
  46 /* Value indicating that recovery needs to re-check a peer immediately. */
  47 #define LNET_REDISCOVER_PEER    (1)
  48
  49 static int lnet_peer_queue_for_discovery(struct lnet_peer *lp);
  50
  51 static void
  52 lnet_peer_remove_from_remote_list(struct lnet_peer_ni *lpni)
  53 {
  54         if (!list_empty(&lpni->lpni_on_remote_peer_ni_list)) {
  55                 list_del_init(&lpni->lpni_on_remote_peer_ni_list);
  56                 lnet_peer_ni_decref_locked(lpni);
  57         }
  58 }
  59
  60 void
  61 lnet_peer_net_added(struct lnet_net *net)
  62 {
  63         struct lnet_peer_ni *lpni, *tmp;
  64
  65         list_for_each_entry_safe(lpni, tmp, &the_lnet.ln_remote_peer_ni_list,
  66                                  lpni_on_remote_peer_ni_list) {
  67
  68                 if (LNET_NIDNET(lpni->lpni_nid) == net->net_id) {
  69                         lpni->lpni_net = net;
  70
  71                         spin_lock(&lpni->lpni_lock);
  72                         lpni->lpni_txcredits =
  73                                 lpni->lpni_net->net_tunables.lct_peer_tx_credits;
  74                         lpni->lpni_mintxcredits = lpni->lpni_txcredits;
  75                         lpni->lpni_rtrcredits =
  76                                 lnet_peer_buffer_credits(lpni->lpni_net);
  77                         lpni->lpni_minrtrcredits = lpni->lpni_rtrcredits;
  78                         spin_unlock(&lpni->lpni_lock);
  79
  80                         lnet_peer_remove_from_remote_list(lpni);
  81                 }
  82         }
  83 }
  84
  85 static void
  86 lnet_peer_tables_destroy(void)
  87 {
  88         struct lnet_peer_table  *ptable;
  89         struct list_head        *hash;
  90         int                     i;
  91         int                     j;
  92
  93         if (!the_lnet.ln_peer_tables)
  94                 return;
  95
  96         cfs_percpt_for_each(ptable, i, the_lnet.ln_peer_tables) {
  97                 hash = ptable->pt_hash;
  98                 if (!hash) /* not intialized */
  99                         break;
 100
 101                 LASSERT(list_empty(&ptable->pt_zombie_list));
 102
 103                 ptable->pt_hash = NULL;
 104                 for (j = 0; j < LNET_PEER_HASH_SIZE; j++)
 105                         LASSERT(list_empty(&hash[j]));
 106
 107                 LIBCFS_FREE(hash, LNET_PEER_HASH_SIZE * sizeof(*hash));
 108         }
 109
 110         cfs_percpt_free(the_lnet.ln_peer_tables);
 111         the_lnet.ln_peer_tables = NULL;
 112 }
 113
 114 int
 115 lnet_peer_tables_create(void)
 116 {
 117         struct lnet_peer_table  *ptable;
 118         struct list_head        *hash;
 119         int                     i;
 120         int                     j;
 121
 122         the_lnet.ln_peer_tables = cfs_percpt_alloc(lnet_cpt_table(),
 123                                                    sizeof(*ptable));
 124         if (the_lnet.ln_peer_tables == NULL) {
 125                 CERROR("Failed to allocate cpu-partition peer tables\n");
 126                 return -ENOMEM;
 127         }
 128
 129         cfs_percpt_for_each(ptable, i, the_lnet.ln_peer_tables) {
 130                 LIBCFS_CPT_ALLOC(hash, lnet_cpt_table(), i,
 131                                  LNET_PEER_HASH_SIZE * sizeof(*hash));
 132                 if (hash == NULL) {
 133                         CERROR("Failed to create peer hash table\n");
 134                         lnet_peer_tables_destroy();
 135                         return -ENOMEM;
 136                 }
 137
 138                 spin_lock_init(&ptable->pt_zombie_lock);
 139                 INIT_LIST_HEAD(&ptable->pt_zombie_list);
 140
 141                 INIT_LIST_HEAD(&ptable->pt_peer_list);
 142
 143                 for (j = 0; j < LNET_PEER_HASH_SIZE; j++)
 144                         INIT_LIST_HEAD(&hash[j]);
 145                 ptable->pt_hash = hash; /* sign of initialization */
 146         }
 147
 148         return 0;
 149 }
 150
 151 static struct lnet_peer_ni *
 152 lnet_peer_ni_alloc(lnet_nid_t nid)
 153 {
 154         struct lnet_peer_ni *lpni;
 155         struct lnet_net *net;
 156         int cpt;
 157
 158         cpt = lnet_nid_cpt_hash(nid, LNET_CPT_NUMBER);
 159
 160         LIBCFS_CPT_ALLOC(lpni, lnet_cpt_table(), cpt, sizeof(*lpni));
 161         if (!lpni)
 162                 return NULL;
 163
 164         INIT_LIST_HEAD(&lpni->lpni_txq);
 165         INIT_LIST_HEAD(&lpni->lpni_hashlist);
 166         INIT_LIST_HEAD(&lpni->lpni_peer_nis);
 167         INIT_LIST_HEAD(&lpni->lpni_recovery);
 168         INIT_LIST_HEAD(&lpni->lpni_on_remote_peer_ni_list);
 169         LNetInvalidateMDHandle(&lpni->lpni_recovery_ping_mdh);
 170
 171         spin_lock_init(&lpni->lpni_lock);
 172
 173         if (lnet_peers_start_down())
 174                 lpni->lpni_ns_status = LNET_NI_STATUS_DOWN;
 175         else
 176                 lpni->lpni_ns_status = LNET_NI_STATUS_UP;
 177         lpni->lpni_ping_feats = LNET_PING_FEAT_INVAL;
 178         lpni->lpni_nid = nid;
 179         lpni->lpni_cpt = cpt;
 180         atomic_set(&lpni->lpni_healthv, LNET_MAX_HEALTH_VALUE);
 181
 182         net = lnet_get_net_locked(LNET_NIDNET(nid));
 183         lpni->lpni_net = net;
 184         if (net) {
 185                 lpni->lpni_txcredits = net->net_tunables.lct_peer_tx_credits;
 186                 lpni->lpni_mintxcredits = lpni->lpni_txcredits;
 187                 lpni->lpni_rtrcredits = lnet_peer_buffer_credits(net);
 188                 lpni->lpni_minrtrcredits = lpni->lpni_rtrcredits;
 189         } else {
 190                 /*
 191                  * This peer_ni is not on a local network, so we
 192                  * cannot add the credits here. In case the net is
 193                  * added later, add the peer_ni to the remote peer ni
 194                  * list so it can be easily found and revisited.
 195                  */
 196                 /* FIXME: per-net implementation instead? */
 197                 atomic_inc(&lpni->lpni_refcount);
 198                 list_add_tail(&lpni->lpni_on_remote_peer_ni_list,
 199                               &the_lnet.ln_remote_peer_ni_list);
 200         }
 201
 202         CDEBUG(D_NET, "%p nid %s\n", lpni, libcfs_nid2str(lpni->lpni_nid));
 203
 204         return lpni;
 205 }
 206
 207 static struct lnet_peer_net *
 208 lnet_peer_net_alloc(__u32 net_id)
 209 {
 210         struct lnet_peer_net *lpn;
 211
 212         LIBCFS_CPT_ALLOC(lpn, lnet_cpt_table(), CFS_CPT_ANY, sizeof(*lpn));
 213         if (!lpn)
 214                 return NULL;
 215
 216         INIT_LIST_HEAD(&lpn->lpn_peer_nets);
 217         INIT_LIST_HEAD(&lpn->lpn_peer_nis);
 218         lpn->lpn_net_id = net_id;
 219
 220         CDEBUG(D_NET, "%p net %s\n", lpn, libcfs_net2str(lpn->lpn_net_id));
 221
 222         return lpn;
 223 }
 224
 225 void
 226 lnet_destroy_peer_net_locked(struct lnet_peer_net *lpn)
 227 {
 228         struct lnet_peer *lp;
 229
 230         CDEBUG(D_NET, "%p net %s\n", lpn, libcfs_net2str(lpn->lpn_net_id));
 231
 232         LASSERT(atomic_read(&lpn->lpn_refcount) == 0);
 233         LASSERT(list_empty(&lpn->lpn_peer_nis));
 234         LASSERT(list_empty(&lpn->lpn_peer_nets));
 235         lp = lpn->lpn_peer;
 236         lpn->lpn_peer = NULL;
 237         LIBCFS_FREE(lpn, sizeof(*lpn));
 238
 239         lnet_peer_decref_locked(lp);
 240 }
 241
 242 static struct lnet_peer *
 243 lnet_peer_alloc(lnet_nid_t nid)
 244 {
 245         struct lnet_peer *lp;
 246
 247         LIBCFS_CPT_ALLOC(lp, lnet_cpt_table(), CFS_CPT_ANY, sizeof(*lp));
 248         if (!lp)
 249                 return NULL;
 250
 251         INIT_LIST_HEAD(&lp->lp_rtrq);
 252         INIT_LIST_HEAD(&lp->lp_routes);
 253         INIT_LIST_HEAD(&lp->lp_peer_list);
 254         INIT_LIST_HEAD(&lp->lp_peer_nets);
 255         INIT_LIST_HEAD(&lp->lp_dc_list);
 256         INIT_LIST_HEAD(&lp->lp_dc_pendq);
 257         INIT_LIST_HEAD(&lp->lp_rtr_list);
 258         init_waitqueue_head(&lp->lp_dc_waitq);
 259         spin_lock_init(&lp->lp_lock);
 260         lp->lp_primary_nid = nid;
 261         if (lnet_peers_start_down())
 262                 lp->lp_alive = false;
 263         else
 264                 lp->lp_alive = true;
 265
 266         /*
 267          * all peers created on a router should have health on
 268          * if it's not already on.
 269          */
 270         if (the_lnet.ln_routing && !lnet_health_sensitivity)
 271                 lp->lp_health_sensitivity = 1;
 272
 273         /*
 274          * Turn off discovery for loopback peer. If you're creating a peer
 275          * for the loopback interface then that was initiated when we
 276          * attempted to send a message over the loopback. There is no need
 277          * to ever use a different interface when sending messages to
 278          * myself.
 279          */
 280         if (LNET_NETTYP(LNET_NIDNET(nid)) == LOLND)
 281                 lp->lp_state = LNET_PEER_NO_DISCOVERY;
 282         lp->lp_cpt = lnet_nid_cpt_hash(nid, LNET_CPT_NUMBER);
 283
 284         CDEBUG(D_NET, "%p nid %s\n", lp, libcfs_nid2str(lp->lp_primary_nid));
 285
 286         return lp;
 287 }
 288
 289 void
 290 lnet_destroy_peer_locked(struct lnet_peer *lp)
 291 {
 292         CDEBUG(D_NET, "%p nid %s\n", lp, libcfs_nid2str(lp->lp_primary_nid));
 293
 294         LASSERT(atomic_read(&lp->lp_refcount) == 0);
 295         LASSERT(lp->lp_rtr_refcount == 0);
 296         LASSERT(list_empty(&lp->lp_peer_nets));
 297         LASSERT(list_empty(&lp->lp_peer_list));
 298         LASSERT(list_empty(&lp->lp_dc_list));
 299
 300         if (lp->lp_data)
 301                 lnet_ping_buffer_decref(lp->lp_data);
 302
 303         /*
 304          * if there are messages still on the pending queue, then make
 305          * sure to queue them on the ln_msg_resend list so they can be
 306          * resent at a later point if the discovery thread is still
 307          * running.
 308          * If the discovery thread has stopped, then the wakeup will be a
 309          * no-op, and it is expected the lnet_shutdown_lndnets() will
 310          * eventually be called, which will traverse this list and
 311          * finalize the messages on the list.
 312          * We can not resend them now because we're holding the cpt lock.
 313          * Releasing the lock can cause an inconsistent state
 314          */
 315         spin_lock(&the_lnet.ln_msg_resend_lock);
 316         spin_lock(&lp->lp_lock);
 317         list_splice(&lp->lp_dc_pendq, &the_lnet.ln_msg_resend);
 318         spin_unlock(&lp->lp_lock);
 319         spin_unlock(&the_lnet.ln_msg_resend_lock);
 320         wake_up(&the_lnet.ln_dc_waitq);
 321
 322         LIBCFS_FREE(lp, sizeof(*lp));
 323 }
 324
 325 /*
 326  * Detach a peer_ni from its peer_net. If this was the last peer_ni on
 327  * that peer_net, detach the peer_net from the peer.
 328  *
 329  * Call with lnet_net_lock/EX held
 330  */
 331 static void
 332 lnet_peer_detach_peer_ni_locked(struct lnet_peer_ni *lpni)
 333 {
 334         struct lnet_peer_table *ptable;
 335         struct lnet_peer_net *lpn;
 336         struct lnet_peer *lp;
 337
 338         /*
 339          * Belts and suspenders: gracefully handle teardown of a
 340          * partially connected peer_ni.
 341          */
 342         lpn = lpni->lpni_peer_net;
 343
 344         list_del_init(&lpni->lpni_peer_nis);
 345         /*
 346          * If there are no lpni's left, we detach lpn from
 347          * lp_peer_nets, so it cannot be found anymore.
 348          */
 349         if (list_empty(&lpn->lpn_peer_nis))
 350                 list_del_init(&lpn->lpn_peer_nets);
 351
 352         /* Update peer NID count. */
 353         lp = lpn->lpn_peer;
 354         lp->lp_nnis--;
 355
 356         /*
 357          * If there are no more peer nets, make the peer unfindable
 358          * via the peer_tables.
 359          *
 360          * Otherwise, if the peer is DISCOVERED, tell discovery to
 361          * take another look at it. This is a no-op if discovery for
 362          * this peer did the detaching.
 363          */
 364         if (list_empty(&lp->lp_peer_nets)) {
 365                 list_del_init(&lp->lp_peer_list);
 366                 ptable = the_lnet.ln_peer_tables[lp->lp_cpt];
 367                 ptable->pt_peers--;
 368         } else if (the_lnet.ln_dc_state != LNET_DC_STATE_RUNNING) {
 369                 /* Discovery isn't running, nothing to do here. */
 370         } else if (lp->lp_state & LNET_PEER_DISCOVERED) {
 371                 lnet_peer_queue_for_discovery(lp);
 372                 wake_up(&the_lnet.ln_dc_waitq);
 373         }
 374         CDEBUG(D_NET, "peer %s NID %s\n",
 375                 libcfs_nid2str(lp->lp_primary_nid),
 376                 libcfs_nid2str(lpni->lpni_nid));
 377 }
 378
 379 /* called with lnet_net_lock LNET_LOCK_EX held */
 380 static int
 381 lnet_peer_ni_del_locked(struct lnet_peer_ni *lpni, bool force)
 382 {
 383         struct lnet_peer_table *ptable = NULL;
 384
 385         /* don't remove a peer_ni if it's also a gateway */
 386         if (lnet_isrouter(lpni) && !force) {
 387                 CERROR("Peer NI %s is a gateway. Can not delete it\n",
 388                        libcfs_nid2str(lpni->lpni_nid));
 389                 return -EBUSY;
 390         }
 391
 392         lnet_peer_remove_from_remote_list(lpni);
 393
 394         /* remove peer ni from the hash list. */
 395         list_del_init(&lpni->lpni_hashlist);
 396
 397         /*
 398          * indicate the peer is being deleted so the monitor thread can
 399          * remove it from the recovery queue.
 400          */
 401         spin_lock(&lpni->lpni_lock);
 402         lpni->lpni_state |= LNET_PEER_NI_DELETING;
 403         spin_unlock(&lpni->lpni_lock);
 404
 405         /* decrement the ref count on the peer table */
 406         ptable = the_lnet.ln_peer_tables[lpni->lpni_cpt];
 407
 408         /*
 409          * The peer_ni can no longer be found with a lookup. But there
 410          * can be current users, so keep track of it on the zombie
 411          * list until the reference count has gone to zero.
 412          *
 413          * The last reference may be lost in a place where the
 414          * lnet_net_lock locks only a single cpt, and that cpt may not
 415          * be lpni->lpni_cpt. So the zombie list of lnet_peer_table
 416          * has its own lock.
 417          */
 418         spin_lock(&ptable->pt_zombie_lock);
 419         list_add(&lpni->lpni_hashlist, &ptable->pt_zombie_list);
 420         ptable->pt_zombies++;
 421         spin_unlock(&ptable->pt_zombie_lock);
 422
 423         /* no need to keep this peer_ni on the hierarchy anymore */
 424         lnet_peer_detach_peer_ni_locked(lpni);
 425
 426         /* remove hashlist reference on peer_ni */
 427         lnet_peer_ni_decref_locked(lpni);
 428
 429         return 0;
 430 }
 431
 432 void lnet_peer_uninit(void)
 433 {
 434         struct lnet_peer_ni *lpni, *tmp;
 435
 436         lnet_net_lock(LNET_LOCK_EX);
 437
 438         /* remove all peer_nis from the remote peer and the hash list */
 439         list_for_each_entry_safe(lpni, tmp, &the_lnet.ln_remote_peer_ni_list,
 440                                  lpni_on_remote_peer_ni_list)
 441                 lnet_peer_ni_del_locked(lpni, false);
 442
 443         lnet_peer_tables_destroy();
 444
 445         lnet_net_unlock(LNET_LOCK_EX);
 446 }
 447
 448 static int
 449 lnet_peer_del_locked(struct lnet_peer *peer)
 450 {
 451         struct lnet_peer_ni *lpni = NULL, *lpni2;
 452         int rc = 0, rc2 = 0;
 453
 454         CDEBUG(D_NET, "peer %s\n", libcfs_nid2str(peer->lp_primary_nid));
 455
 456         lpni = lnet_get_next_peer_ni_locked(peer, NULL, lpni);
 457         while (lpni != NULL) {
 458                 lpni2 = lnet_get_next_peer_ni_locked(peer, NULL, lpni);
 459                 rc = lnet_peer_ni_del_locked(lpni, false);
 460                 if (rc != 0)
 461                         rc2 = rc;
 462                 lpni = lpni2;
 463         }
 464
 465         return rc2;
 466 }
 467
 468 static int
 469 lnet_peer_del(struct lnet_peer *peer)
 470 {
 471         lnet_net_lock(LNET_LOCK_EX);
 472         lnet_peer_del_locked(peer);
 473         lnet_net_unlock(LNET_LOCK_EX);
 474
 475         return 0;
 476 }
 477
 478 /*
 479  * Delete a NID from a peer. Call with ln_api_mutex held.
 480  *
 481  * Error codes:
 482  *  -EPERM:  Non-DLC deletion from DLC-configured peer.
 483  *  -ENOENT: No lnet_peer_ni corresponding to the nid.
 484  *  -ECHILD: The lnet_peer_ni isn't connected to the peer.
 485  *  -EBUSY:  The lnet_peer_ni is the primary, and not the only peer_ni.
 486  */
 487 static int
 488 lnet_peer_del_nid(struct lnet_peer *lp, lnet_nid_t nid, unsigned flags)
 489 {
 490         struct lnet_peer_ni *lpni;
 491         lnet_nid_t primary_nid = lp->lp_primary_nid;
 492         int rc = 0;
 493         bool force = (flags & LNET_PEER_RTR_NI_FORCE_DEL) ? true : false;
 494
 495         if (!(flags & LNET_PEER_CONFIGURED)) {
 496                 if (lp->lp_state & LNET_PEER_CONFIGURED) {
 497                         rc = -EPERM;
 498                         goto out;
 499                 }
 500         }
 501         lpni = lnet_find_peer_ni_locked(nid);
 502         if (!lpni) {
 503                 rc = -ENOENT;
 504                 goto out;
 505         }
 506         lnet_peer_ni_decref_locked(lpni);
 507         if (lp != lpni->lpni_peer_net->lpn_peer) {
 508                 rc = -ECHILD;
 509                 goto out;
 510         }
 511
 512         /*
 513          * This function only allows deletion of the primary NID if it
 514          * is the only NID.
 515          */
 516         if (nid == lp->lp_primary_nid && lp->lp_nnis != 1 && !force) {
 517                 rc = -EBUSY;
 518                 goto out;
 519         }
 520
 521         lnet_net_lock(LNET_LOCK_EX);
 522
 523         if (nid == lp->lp_primary_nid && lp->lp_nnis != 1 && force) {
 524                 struct lnet_peer_ni *lpni2;
 525                 /* assign the next peer_ni to be the primary */
 526                 lpni2 = lnet_get_next_peer_ni_locked(lp, NULL, lpni);
 527                 LASSERT(lpni2);
 528                 lp->lp_primary_nid = lpni->lpni_nid;
 529         }
 530         rc = lnet_peer_ni_del_locked(lpni, force);
 531
 532         lnet_net_unlock(LNET_LOCK_EX);
 533
 534 out:
 535         CDEBUG(D_NET, "peer %s NID %s flags %#x: %d\n",
 536                libcfs_nid2str(primary_nid), libcfs_nid2str(nid), flags, rc);
 537
 538         return rc;
 539 }
 540
 541 static void
 542 lnet_peer_table_cleanup_locked(struct lnet_net *net,
 543                                struct lnet_peer_table *ptable)
 544 {
 545         int                      i;
 546         struct lnet_peer_ni     *next;
 547         struct lnet_peer_ni     *lpni;
 548         struct lnet_peer        *peer;
 549
 550         for (i = 0; i < LNET_PEER_HASH_SIZE; i++) {
 551                 list_for_each_entry_safe(lpni, next, &ptable->pt_hash[i],
 552                                          lpni_hashlist) {
 553                         if (net != NULL && net != lpni->lpni_net)
 554                                 continue;
 555
 556                         peer = lpni->lpni_peer_net->lpn_peer;
 557                         if (peer->lp_primary_nid != lpni->lpni_nid) {
 558                                 lnet_peer_ni_del_locked(lpni, false);
 559                                 continue;
 560                         }
 561                         /*
 562                          * Removing the primary NID implies removing
 563                          * the entire peer. Advance next beyond any
 564                          * peer_ni that belongs to the same peer.
 565                          */
 566                         list_for_each_entry_from(next, &ptable->pt_hash[i],
 567                                                  lpni_hashlist) {
 568                                 if (next->lpni_peer_net->lpn_peer != peer)
 569                                         break;
 570                         }
 571                         lnet_peer_del_locked(peer);
 572                 }
 573         }
 574 }
 575
 576 static void
 577 lnet_peer_ni_finalize_wait(struct lnet_peer_table *ptable)
 578 {
 579         int     i = 3;
 580
 581         spin_lock(&ptable->pt_zombie_lock);
 582         while (ptable->pt_zombies) {
 583                 spin_unlock(&ptable->pt_zombie_lock);
 584
 585                 if (is_power_of_2(i)) {
 586                         CDEBUG(D_WARNING,
 587                                "Waiting for %d zombies on peer table\n",
 588                                ptable->pt_zombies);
 589                 }
 590                 set_current_state(TASK_UNINTERRUPTIBLE);
 591                 schedule_timeout(cfs_time_seconds(1) >> 1);
 592                 spin_lock(&ptable->pt_zombie_lock);
 593         }
 594         spin_unlock(&ptable->pt_zombie_lock);
 595 }
 596
 597 static void
 598 lnet_peer_table_del_rtrs_locked(struct lnet_net *net,
 599                                 struct lnet_peer_table *ptable)
 600 {
 601         struct lnet_peer_ni     *lp;
 602         struct lnet_peer_ni     *tmp;
 603         lnet_nid_t              gw_nid;
 604         int                     i;
 605
 606         for (i = 0; i < LNET_PEER_HASH_SIZE; i++) {
 607                 list_for_each_entry_safe(lp, tmp, &ptable->pt_hash[i],
 608                                          lpni_hashlist) {
 609                         if (net != lp->lpni_net)
 610                                 continue;
 611
 612                         if (!lnet_isrouter(lp))
 613                                 continue;
 614
 615                         gw_nid = lp->lpni_peer_net->lpn_peer->lp_primary_nid;
 616
 617                         lnet_net_unlock(LNET_LOCK_EX);
 618                         lnet_del_route(LNET_NIDNET(LNET_NID_ANY), gw_nid);
 619                         lnet_net_lock(LNET_LOCK_EX);
 620                 }
 621         }
 622 }
 623
 624 void
 625 lnet_peer_tables_cleanup(struct lnet_net *net)
 626 {
 627         int i;
 628         struct lnet_peer_table *ptable;
 629
 630         LASSERT(the_lnet.ln_state != LNET_STATE_SHUTDOWN || net != NULL);
 631         /* If just deleting the peers for a NI, get rid of any routes these
 632          * peers are gateways for. */
 633         cfs_percpt_for_each(ptable, i, the_lnet.ln_peer_tables) {
 634                 lnet_net_lock(LNET_LOCK_EX);
 635                 lnet_peer_table_del_rtrs_locked(net, ptable);
 636                 lnet_net_unlock(LNET_LOCK_EX);
 637         }
 638
 639         /* Start the cleanup process */
 640         cfs_percpt_for_each(ptable, i, the_lnet.ln_peer_tables) {
 641                 lnet_net_lock(LNET_LOCK_EX);
 642                 lnet_peer_table_cleanup_locked(net, ptable);
 643                 lnet_net_unlock(LNET_LOCK_EX);
 644         }
 645
 646         cfs_percpt_for_each(ptable, i, the_lnet.ln_peer_tables)
 647                 lnet_peer_ni_finalize_wait(ptable);
 648 }
 649
 650 static struct lnet_peer_ni *
 651 lnet_get_peer_ni_locked(struct lnet_peer_table *ptable, lnet_nid_t nid)
 652 {
 653         struct list_head        *peers;
 654         struct lnet_peer_ni     *lp;
 655
 656         if (the_lnet.ln_state != LNET_STATE_RUNNING)
 657                 return NULL;
 658
 659         peers = &ptable->pt_hash[lnet_nid2peerhash(nid)];
 660         list_for_each_entry(lp, peers, lpni_hashlist) {
 661                 if (lp->lpni_nid == nid) {
 662                         lnet_peer_ni_addref_locked(lp);
 663                         return lp;
 664                 }
 665         }
 666
 667         return NULL;
 668 }
 669
 670 struct lnet_peer_ni *
 671 lnet_find_peer_ni_locked(lnet_nid_t nid)
 672 {
 673         struct lnet_peer_ni *lpni;
 674         struct lnet_peer_table *ptable;
 675         int cpt;
 676
 677         cpt = lnet_nid_cpt_hash(nid, LNET_CPT_NUMBER);
 678
 679         ptable = the_lnet.ln_peer_tables[cpt];
 680         lpni = lnet_get_peer_ni_locked(ptable, nid);
 681
 682         return lpni;
 683 }
 684
 685 struct lnet_peer_ni *
 686 lnet_peer_get_ni_locked(struct lnet_peer *lp, lnet_nid_t nid)
 687 {
 688         struct lnet_peer_net *lpn;
 689         struct lnet_peer_ni *lpni;
 690
 691         lpn = lnet_peer_get_net_locked(lp, LNET_NIDNET(nid));
 692         if (!lpn)
 693                 return NULL;
 694
 695         list_for_each_entry(lpni, &lpn->lpn_peer_nis, lpni_peer_nis) {
 696                 if (lpni->lpni_nid == nid)
 697                         return lpni;
 698         }
 699
 700         return NULL;
 701 }
 702
 703 struct lnet_peer *
 704 lnet_find_peer(lnet_nid_t nid)
 705 {
 706         struct lnet_peer_ni *lpni;
 707         struct lnet_peer *lp = NULL;
 708         int cpt;
 709
 710         cpt = lnet_net_lock_current();
 711         lpni = lnet_find_peer_ni_locked(nid);
 712         if (lpni) {
 713                 lp = lpni->lpni_peer_net->lpn_peer;
 714                 lnet_peer_addref_locked(lp);
 715                 lnet_peer_ni_decref_locked(lpni);
 716         }
 717         lnet_net_unlock(cpt);
 718
 719         return lp;
 720 }
 721
 722 struct lnet_peer_net *
 723 lnet_get_next_peer_net_locked(struct lnet_peer *lp, __u32 prev_lpn_id)
 724 {
 725         struct lnet_peer_net *net;
 726
 727         if (!prev_lpn_id) {
 728                 /* no net id provided return the first net */
 729                 net = list_first_entry_or_null(&lp->lp_peer_nets,
 730                                                struct lnet_peer_net,
 731                                                lpn_peer_nets);
 732
 733                 return net;
 734         }
 735
 736         /* find the net after the one provided */
 737         list_for_each_entry(net, &lp->lp_peer_nets, lpn_peer_nets) {
 738                 if (net->lpn_net_id == prev_lpn_id) {
 739                         /*
 740                          * if we reached the end of the list loop to the
 741                          * beginning.
 742                          */
 743                         if (net->lpn_peer_nets.next == &lp->lp_peer_nets)
 744                                 return list_first_entry_or_null(&lp->lp_peer_nets,
 745                                                                 struct lnet_peer_net,
 746                                                                 lpn_peer_nets);
 747                         else
 748                                 return list_next_entry(net, lpn_peer_nets);
 749                 }
 750         }
 751
 752         return NULL;
 753 }
 754
 755 struct lnet_peer_ni *
 756 lnet_get_next_peer_ni_locked(struct lnet_peer *peer,
 757                              struct lnet_peer_net *peer_net,
 758                              struct lnet_peer_ni *prev)
 759 {
 760         struct lnet_peer_ni *lpni;
 761         struct lnet_peer_net *net = peer_net;
 762
 763         if (!prev) {
 764                 if (!net) {
 765                         if (list_empty(&peer->lp_peer_nets))
 766                                 return NULL;
 767
 768                         net = list_entry(peer->lp_peer_nets.next,
 769                                          struct lnet_peer_net,
 770                                          lpn_peer_nets);
 771                 }
 772                 lpni = list_entry(net->lpn_peer_nis.next, struct lnet_peer_ni,
 773                                   lpni_peer_nis);
 774
 775                 return lpni;
 776         }
 777
 778         if (prev->lpni_peer_nis.next == &prev->lpni_peer_net->lpn_peer_nis) {
 779                 /*
 780                  * if you reached the end of the peer ni list and the peer
 781                  * net is specified then there are no more peer nis in that
 782                  * net.
 783                  */
 784                 if (net)
 785                         return NULL;
 786
 787                 /*
 788                  * we reached the end of this net ni list. move to the
 789                  * next net
 790                  */
 791                 if (prev->lpni_peer_net->lpn_peer_nets.next ==
 792                     &peer->lp_peer_nets)
 793                         /* no more nets and no more NIs. */
 794                         return NULL;
 795
 796                 /* get the next net */
 797                 net = list_entry(prev->lpni_peer_net->lpn_peer_nets.next,
 798                                  struct lnet_peer_net,
 799                                  lpn_peer_nets);
 800                 /* get the ni on it */
 801                 lpni = list_entry(net->lpn_peer_nis.next, struct lnet_peer_ni,
 802                                   lpni_peer_nis);
 803
 804                 return lpni;
 805         }
 806
 807         /* there are more nis left */
 808         lpni = list_entry(prev->lpni_peer_nis.next,
 809                           struct lnet_peer_ni, lpni_peer_nis);
 810
 811         return lpni;
 812 }
 813
 814 /* Call with the ln_api_mutex held */
 815 int lnet_get_peer_list(u32 *countp, u32 *sizep, struct lnet_process_id __user *ids)
 816 {
 817         struct lnet_process_id id;
 818         struct lnet_peer_table *ptable;
 819         struct lnet_peer *lp;
 820         __u32 count = 0;
 821         __u32 size = 0;
 822         int lncpt;
 823         int cpt;
 824         __u32 i;
 825         int rc;
 826
 827         rc = -ESHUTDOWN;
 828         if (the_lnet.ln_state != LNET_STATE_RUNNING)
 829                 goto done;
 830
 831         lncpt = cfs_percpt_number(the_lnet.ln_peer_tables);
 832
 833         /*
 834          * Count the number of peers, and return E2BIG if the buffer
 835          * is too small. We'll also return the desired size.
 836          */
 837         rc = -E2BIG;
 838         for (cpt = 0; cpt < lncpt; cpt++) {
 839                 ptable = the_lnet.ln_peer_tables[cpt];
 840                 count += ptable->pt_peers;
 841         }
 842         size = count * sizeof(*ids);
 843         if (size > *sizep)
 844                 goto done;
 845
 846         /*
 847          * Walk the peer lists and copy out the primary nids.
 848          * This is safe because the peer lists are only modified
 849          * while the ln_api_mutex is held. So we don't need to
 850          * hold the lnet_net_lock as well, and can therefore
 851          * directly call copy_to_user().
 852          */
 853         rc = -EFAULT;
 854         memset(&id, 0, sizeof(id));
 855         id.pid = LNET_PID_LUSTRE;
 856         i = 0;
 857         for (cpt = 0; cpt < lncpt; cpt++) {
 858                 ptable = the_lnet.ln_peer_tables[cpt];
 859                 list_for_each_entry(lp, &ptable->pt_peer_list, lp_peer_list) {
 860                         if (i >= count)
 861                                 goto done;
 862                         id.nid = lp->lp_primary_nid;
 863                         if (copy_to_user(&ids[i], &id, sizeof(id)))
 864                                 goto done;
 865                         i++;
 866                 }
 867         }
 868         rc = 0;
 869 done:
 870         *countp = count;
 871         *sizep = size;
 872         return rc;
 873 }
 874
 875 /*
 876  * Start pushes to peers that need to be updated for a configuration
 877  * change on this node.
 878  */
 879 void
 880 lnet_push_update_to_peers(int force)
 881 {
 882         struct lnet_peer_table *ptable;
 883         struct lnet_peer *lp;
 884         int lncpt;
 885         int cpt;
 886
 887         lnet_net_lock(LNET_LOCK_EX);
 888         if (lnet_peer_discovery_disabled)
 889                 force = 0;
 890         lncpt = cfs_percpt_number(the_lnet.ln_peer_tables);
 891         for (cpt = 0; cpt < lncpt; cpt++) {
 892                 ptable = the_lnet.ln_peer_tables[cpt];
 893                 list_for_each_entry(lp, &ptable->pt_peer_list, lp_peer_list) {
 894                         if (force) {
 895                                 spin_lock(&lp->lp_lock);
 896                                 if (lp->lp_state & LNET_PEER_MULTI_RAIL)
 897                                         lp->lp_state |= LNET_PEER_FORCE_PUSH;
 898                                 spin_unlock(&lp->lp_lock);
 899                         }
 900                         if (lnet_peer_needs_push(lp))
 901                                 lnet_peer_queue_for_discovery(lp);
 902                 }
 903         }
 904         lnet_net_unlock(LNET_LOCK_EX);
 905         wake_up(&the_lnet.ln_dc_waitq);
 906 }
 907
 908 /*
 909  * Test whether a ni is a preferred ni for this peer_ni, e.g, whether
 910  * this is a preferred point-to-point path. Call with lnet_net_lock in
 911  * shared mmode.
 912  */
 913 bool
 914 lnet_peer_is_pref_nid_locked(struct lnet_peer_ni *lpni, lnet_nid_t nid)
 915 {
 916         int i;
 917
 918         if (lpni->lpni_pref_nnids == 0)
 919                 return false;
 920         if (lpni->lpni_pref_nnids == 1)
 921                 return lpni->lpni_pref.nid == nid;
 922         for (i = 0; i < lpni->lpni_pref_nnids; i++) {
 923                 if (lpni->lpni_pref.nids[i] == nid)
 924                         return true;
 925         }
 926         return false;
 927 }
 928
 929 /*
 930  * Set a single ni as preferred, provided no preferred ni is already
 931  * defined. Only to be used for non-multi-rail peer_ni.
 932  */
 933 int
 934 lnet_peer_ni_set_non_mr_pref_nid(struct lnet_peer_ni *lpni, lnet_nid_t nid)
 935 {
 936         int rc = 0;
 937
 938         spin_lock(&lpni->lpni_lock);
 939         if (nid == LNET_NID_ANY) {
 940                 rc = -EINVAL;
 941         } else if (lpni->lpni_pref_nnids > 0) {
 942                 rc = -EPERM;
 943         } else if (lpni->lpni_pref_nnids == 0) {
 944                 lpni->lpni_pref.nid = nid;
 945                 lpni->lpni_pref_nnids = 1;
 946                 lpni->lpni_state |= LNET_PEER_NI_NON_MR_PREF;
 947         }
 948         spin_unlock(&lpni->lpni_lock);
 949
 950         CDEBUG(D_NET, "peer %s nid %s: %d\n",
 951                libcfs_nid2str(lpni->lpni_nid), libcfs_nid2str(nid), rc);
 952         return rc;
 953 }
 954
 955 /*
 956  * Clear the preferred NID from a non-multi-rail peer_ni, provided
 957  * this preference was set by lnet_peer_ni_set_non_mr_pref_nid().
 958  */
 959 int
 960 lnet_peer_ni_clr_non_mr_pref_nid(struct lnet_peer_ni *lpni)
 961 {
 962         int rc = 0;
 963
 964         spin_lock(&lpni->lpni_lock);
 965         if (lpni->lpni_state & LNET_PEER_NI_NON_MR_PREF) {
 966                 lpni->lpni_pref_nnids = 0;
 967                 lpni->lpni_state &= ~LNET_PEER_NI_NON_MR_PREF;
 968         } else if (lpni->lpni_pref_nnids == 0) {
 969                 rc = -ENOENT;
 970         } else {
 971                 rc = -EPERM;
 972         }
 973         spin_unlock(&lpni->lpni_lock);
 974
 975         CDEBUG(D_NET, "peer %s: %d\n",
 976                libcfs_nid2str(lpni->lpni_nid), rc);
 977         return rc;
 978 }
 979
 980 /*
 981  * Clear the preferred NIDs from a non-multi-rail peer.
 982  */
 983 void
 984 lnet_peer_clr_non_mr_pref_nids(struct lnet_peer *lp)
 985 {
 986         struct lnet_peer_ni *lpni = NULL;
 987
 988         while ((lpni = lnet_get_next_peer_ni_locked(lp, NULL, lpni)) != NULL)
 989                 lnet_peer_ni_clr_non_mr_pref_nid(lpni);
 990 }
 991
 992 int
 993 lnet_peer_add_pref_nid(struct lnet_peer_ni *lpni, lnet_nid_t nid)
 994 {
 995         lnet_nid_t *nids = NULL;
 996         lnet_nid_t *oldnids = NULL;
 997         struct lnet_peer *lp = lpni->lpni_peer_net->lpn_peer;
 998         int size;
 999         int i;
1000         int rc = 0;
1001
1002         if (nid == LNET_NID_ANY) {
1003                 rc = -EINVAL;
1004                 goto out;
1005         }
1006
1007         if (lpni->lpni_pref_nnids == 1 && lpni->lpni_pref.nid == nid) {
1008                 rc = -EEXIST;
1009                 goto out;
1010         }
1011
1012         /* A non-MR node may have only one preferred NI per peer_ni */
1013         if (lpni->lpni_pref_nnids > 0) {
1014                 if (!(lp->lp_state & LNET_PEER_MULTI_RAIL)) {
1015                         rc = -EPERM;
1016                         goto out;
1017                 }
1018         }
1019
1020         if (lpni->lpni_pref_nnids != 0) {
1021                 size = sizeof(*nids) * (lpni->lpni_pref_nnids + 1);
1022                 LIBCFS_CPT_ALLOC(nids, lnet_cpt_table(), lpni->lpni_cpt, size);
1023                 if (!nids) {
1024                         rc = -ENOMEM;
1025                         goto out;
1026                 }
1027                 for (i = 0; i < lpni->lpni_pref_nnids; i++) {
1028                         if (lpni->lpni_pref.nids[i] == nid) {
1029                                 LIBCFS_FREE(nids, size);
1030                                 rc = -EEXIST;
1031                                 goto out;
1032                         }
1033                         nids[i] = lpni->lpni_pref.nids[i];
1034                 }
1035                 nids[i] = nid;
1036         }
1037
1038         lnet_net_lock(LNET_LOCK_EX);
1039         spin_lock(&lpni->lpni_lock);
1040         if (lpni->lpni_pref_nnids == 0) {
1041                 lpni->lpni_pref.nid = nid;
1042         } else {
1043                 oldnids = lpni->lpni_pref.nids;
1044                 lpni->lpni_pref.nids = nids;
1045         }
1046         lpni->lpni_pref_nnids++;
1047         lpni->lpni_state &= ~LNET_PEER_NI_NON_MR_PREF;
1048         spin_unlock(&lpni->lpni_lock);
1049         lnet_net_unlock(LNET_LOCK_EX);
1050
1051         if (oldnids) {
1052                 size = sizeof(*nids) * (lpni->lpni_pref_nnids - 1);
1053                 LIBCFS_FREE(oldnids, sizeof(*oldnids) * size);
1054         }
1055 out:
1056         if (rc == -EEXIST && (lpni->lpni_state & LNET_PEER_NI_NON_MR_PREF)) {
1057                 spin_lock(&lpni->lpni_lock);
1058                 lpni->lpni_state &= ~LNET_PEER_NI_NON_MR_PREF;
1059                 spin_unlock(&lpni->lpni_lock);
1060         }
1061         CDEBUG(D_NET, "peer %s nid %s: %d\n",
1062                libcfs_nid2str(lp->lp_primary_nid), libcfs_nid2str(nid), rc);
1063         return rc;
1064 }
1065
1066 int
1067 lnet_peer_del_pref_nid(struct lnet_peer_ni *lpni, lnet_nid_t nid)
1068 {
1069         lnet_nid_t *nids = NULL;
1070         lnet_nid_t *oldnids = NULL;
1071         struct lnet_peer *lp = lpni->lpni_peer_net->lpn_peer;
1072         int size;
1073         int i, j;
1074         int rc = 0;
1075
1076         if (lpni->lpni_pref_nnids == 0) {
1077                 rc = -ENOENT;
1078                 goto out;
1079         }
1080
1081         if (lpni->lpni_pref_nnids == 1) {
1082                 if (lpni->lpni_pref.nid != nid) {
1083                         rc = -ENOENT;
1084                         goto out;
1085                 }
1086         } else if (lpni->lpni_pref_nnids == 2) {
1087                 if (lpni->lpni_pref.nids[0] != nid &&
1088                     lpni->lpni_pref.nids[1] != nid) {
1089                         rc = -ENOENT;
1090                         goto out;
1091                 }
1092         } else {
1093                 size = sizeof(*nids) * (lpni->lpni_pref_nnids - 1);
1094                 LIBCFS_CPT_ALLOC(nids, lnet_cpt_table(), lpni->lpni_cpt, size);
1095                 if (!nids) {
1096                         rc = -ENOMEM;
1097                         goto out;
1098                 }
1099                 for (i = 0, j = 0; i < lpni->lpni_pref_nnids; i++) {
1100                         if (lpni->lpni_pref.nids[i] != nid)
1101                                 continue;
1102                         nids[j++] = lpni->lpni_pref.nids[i];
1103                 }
1104                 /* Check if we actually removed a nid. */
1105                 if (j == lpni->lpni_pref_nnids) {
1106                         LIBCFS_FREE(nids, size);
1107                         rc = -ENOENT;
1108                         goto out;
1109                 }
1110         }
1111
1112         lnet_net_lock(LNET_LOCK_EX);
1113         spin_lock(&lpni->lpni_lock);
1114         if (lpni->lpni_pref_nnids == 1) {
1115                 lpni->lpni_pref.nid = LNET_NID_ANY;
1116         } else if (lpni->lpni_pref_nnids == 2) {
1117                 oldnids = lpni->lpni_pref.nids;
1118                 if (oldnids[0] == nid)
1119                         lpni->lpni_pref.nid = oldnids[1];
1120                 else
1121                         lpni->lpni_pref.nid = oldnids[2];
1122         } else {
1123                 oldnids = lpni->lpni_pref.nids;
1124                 lpni->lpni_pref.nids = nids;
1125         }
1126         lpni->lpni_pref_nnids--;
1127         lpni->lpni_state &= ~LNET_PEER_NI_NON_MR_PREF;
1128         spin_unlock(&lpni->lpni_lock);
1129         lnet_net_unlock(LNET_LOCK_EX);
1130
1131         if (oldnids) {
1132                 size = sizeof(*nids) * (lpni->lpni_pref_nnids + 1);
1133                 LIBCFS_FREE(oldnids, sizeof(*oldnids) * size);
1134         }
1135 out:
1136         CDEBUG(D_NET, "peer %s nid %s: %d\n",
1137                libcfs_nid2str(lp->lp_primary_nid), libcfs_nid2str(nid), rc);
1138         return rc;
1139 }
1140
1141 lnet_nid_t
1142 lnet_peer_primary_nid_locked(lnet_nid_t nid)
1143 {
1144         struct lnet_peer_ni *lpni;
1145         lnet_nid_t primary_nid = nid;
1146
1147         lpni = lnet_find_peer_ni_locked(nid);
1148         if (lpni) {
1149                 primary_nid = lpni->lpni_peer_net->lpn_peer->lp_primary_nid;
1150                 lnet_peer_ni_decref_locked(lpni);
1151         }
1152
1153         return primary_nid;
1154 }
1155
1156 bool
1157 lnet_is_discovery_disabled_locked(struct lnet_peer *lp)
1158 __must_hold(&lp->lp_lock)
1159 {
1160         if (lnet_peer_discovery_disabled)
1161                 return true;
1162
1163         if (!(lp->lp_state & LNET_PEER_MULTI_RAIL) ||
1164             (lp->lp_state & LNET_PEER_NO_DISCOVERY)) {
1165                 return true;
1166         }
1167
1168         return false;
1169 }
1170
1171 /*
1172  * Peer Discovery
1173  */
1174 bool
1175 lnet_is_discovery_disabled(struct lnet_peer *lp)
1176 {
1177         bool rc = false;
1178
1179         spin_lock(&lp->lp_lock);
1180         rc = lnet_is_discovery_disabled_locked(lp);
1181         spin_unlock(&lp->lp_lock);
1182
1183         return rc;
1184 }
1185
1186 lnet_nid_t
1187 LNetPrimaryNID(lnet_nid_t nid)
1188 {
1189         struct lnet_peer *lp;
1190         struct lnet_peer_ni *lpni;
1191         lnet_nid_t primary_nid = nid;
1192         int rc = 0;
1193         int cpt;
1194
1195         cpt = lnet_net_lock_current();
1196         lpni = lnet_nid2peerni_locked(nid, LNET_NID_ANY, cpt);
1197         if (IS_ERR(lpni)) {
1198                 rc = PTR_ERR(lpni);
1199                 goto out_unlock;
1200         }
1201         lp = lpni->lpni_peer_net->lpn_peer;
1202
1203         while (!lnet_peer_is_uptodate(lp)) {
1204                 rc = lnet_discover_peer_locked(lpni, cpt, true);
1205                 if (rc)
1206                         goto out_decref;
1207                 lp = lpni->lpni_peer_net->lpn_peer;
1208
1209                 /* Only try once if discovery is disabled */
1210                 if (lnet_is_discovery_disabled(lp))
1211                         break;
1212         }
1213         primary_nid = lp->lp_primary_nid;
1214 out_decref:
1215         lnet_peer_ni_decref_locked(lpni);
1216 out_unlock:
1217         lnet_net_unlock(cpt);
1218
1219         CDEBUG(D_NET, "NID %s primary NID %s rc %d\n", libcfs_nid2str(nid),
1220                libcfs_nid2str(primary_nid), rc);
1221         return primary_nid;
1222 }
1223 EXPORT_SYMBOL(LNetPrimaryNID);
1224
1225 struct lnet_peer_net *
1226 lnet_peer_get_net_locked(struct lnet_peer *peer, __u32 net_id)
1227 {
1228         struct lnet_peer_net *peer_net;
1229         list_for_each_entry(peer_net, &peer->lp_peer_nets, lpn_peer_nets) {
1230                 if (peer_net->lpn_net_id == net_id)
1231                         return peer_net;
1232         }
1233         return NULL;
1234 }
1235
1236 /*
1237  * Attach a peer_ni to a peer_net and peer. This function assumes
1238  * peer_ni is not already attached to the peer_net/peer. The peer_ni
1239  * may be attached to a different peer, in which case it will be
1240  * properly detached first. The whole operation is done atomically.
1241  *
1242  * Always returns 0.  This is the last function called from functions
1243  * that do return an int, so returning 0 here allows the compiler to
1244  * do a tail call.
1245  */
1246 static int
1247 lnet_peer_attach_peer_ni(struct lnet_peer *lp,
1248                                 struct lnet_peer_net *lpn,
1249                                 struct lnet_peer_ni *lpni,
1250                                 unsigned flags)
1251 {
1252         struct lnet_peer_table *ptable;
1253
1254         /* Install the new peer_ni */
1255         lnet_net_lock(LNET_LOCK_EX);
1256         /* Add peer_ni to global peer table hash, if necessary. */
1257         if (list_empty(&lpni->lpni_hashlist)) {
1258                 int hash = lnet_nid2peerhash(lpni->lpni_nid);
1259
1260                 ptable = the_lnet.ln_peer_tables[lpni->lpni_cpt];
1261                 list_add_tail(&lpni->lpni_hashlist, &ptable->pt_hash[hash]);
1262                 ptable->pt_version++;
1263                 /* This is the 1st refcount on lpni. */
1264                 atomic_inc(&lpni->lpni_refcount);
1265         }
1266
1267         /* Detach the peer_ni from an existing peer, if necessary. */
1268         if (lpni->lpni_peer_net) {
1269                 LASSERT(lpni->lpni_peer_net != lpn);
1270                 LASSERT(lpni->lpni_peer_net->lpn_peer != lp);
1271                 lnet_peer_detach_peer_ni_locked(lpni);
1272                 lnet_peer_net_decref_locked(lpni->lpni_peer_net);
1273                 lpni->lpni_peer_net = NULL;
1274         }
1275
1276         /* Add peer_ni to peer_net */
1277         lpni->lpni_peer_net = lpn;
1278         list_add_tail(&lpni->lpni_peer_nis, &lpn->lpn_peer_nis);
1279         lnet_peer_net_addref_locked(lpn);
1280
1281         /* Add peer_net to peer */
1282         if (!lpn->lpn_peer) {
1283                 lpn->lpn_peer = lp;
1284                 list_add_tail(&lpn->lpn_peer_nets, &lp->lp_peer_nets);
1285                 lnet_peer_addref_locked(lp);
1286         }
1287
1288         /* Add peer to global peer list, if necessary */
1289         ptable = the_lnet.ln_peer_tables[lp->lp_cpt];
1290         if (list_empty(&lp->lp_peer_list)) {
1291                 list_add_tail(&lp->lp_peer_list, &ptable->pt_peer_list);
1292                 ptable->pt_peers++;
1293         }
1294
1295
1296         /* Update peer state */
1297         spin_lock(&lp->lp_lock);
1298         if (flags & LNET_PEER_CONFIGURED) {
1299                 if (!(lp->lp_state & LNET_PEER_CONFIGURED))
1300                         lp->lp_state |= LNET_PEER_CONFIGURED;
1301         }
1302         if (flags & LNET_PEER_MULTI_RAIL) {
1303                 if (!(lp->lp_state & LNET_PEER_MULTI_RAIL)) {
1304                         lp->lp_state |= LNET_PEER_MULTI_RAIL;
1305                         lnet_peer_clr_non_mr_pref_nids(lp);
1306                 }
1307         }
1308         spin_unlock(&lp->lp_lock);
1309
1310         lp->lp_nnis++;
1311         lnet_net_unlock(LNET_LOCK_EX);
1312
1313         CDEBUG(D_NET, "peer %s NID %s flags %#x\n",
1314                libcfs_nid2str(lp->lp_primary_nid),
1315                libcfs_nid2str(lpni->lpni_nid), flags);
1316
1317         return 0;
1318 }
1319
1320 /*
1321  * Create a new peer, with nid as its primary nid.
1322  *
1323  * Call with the lnet_api_mutex held.
1324  */
1325 static int
1326 lnet_peer_add(lnet_nid_t nid, unsigned flags)
1327 {
1328         struct lnet_peer *lp;
1329         struct lnet_peer_net *lpn;
1330         struct lnet_peer_ni *lpni;
1331         int rc = 0;
1332
1333         LASSERT(nid != LNET_NID_ANY);
1334
1335         /*
1336          * No need for the lnet_net_lock here, because the
1337          * lnet_api_mutex is held.
1338          */
1339         lpni = lnet_find_peer_ni_locked(nid);
1340         if (lpni) {
1341                 /* A peer with this NID already exists. */
1342                 lp = lpni->lpni_peer_net->lpn_peer;
1343                 lnet_peer_ni_decref_locked(lpni);
1344                 /*
1345                  * This is an error if the peer was configured and the
1346                  * primary NID differs or an attempt is made to change
1347                  * the Multi-Rail flag. Otherwise the assumption is
1348                  * that an existing peer is being modified.
1349                  */
1350                 if (lp->lp_state & LNET_PEER_CONFIGURED) {
1351                         if (lp->lp_primary_nid != nid)
1352                                 rc = -EEXIST;
1353                         else if ((lp->lp_state ^ flags) & LNET_PEER_MULTI_RAIL)
1354                                 rc = -EPERM;
1355                         goto out;
1356                 }
1357                 /* Delete and recreate as a configured peer. */
1358                 lnet_peer_del(lp);
1359         }
1360
1361         /* Create peer, peer_net, and peer_ni. */
1362         rc = -ENOMEM;
1363         lp = lnet_peer_alloc(nid);
1364         if (!lp)
1365                 goto out;
1366         lpn = lnet_peer_net_alloc(LNET_NIDNET(nid));
1367         if (!lpn)
1368                 goto out_free_lp;
1369         lpni = lnet_peer_ni_alloc(nid);
1370         if (!lpni)
1371                 goto out_free_lpn;
1372
1373         return lnet_peer_attach_peer_ni(lp, lpn, lpni, flags);
1374
1375 out_free_lpn:
1376         LIBCFS_FREE(lpn, sizeof(*lpn));
1377 out_free_lp:
1378         LIBCFS_FREE(lp, sizeof(*lp));
1379 out:
1380         CDEBUG(D_NET, "peer %s NID flags %#x: %d\n",
1381                libcfs_nid2str(nid), flags, rc);
1382         return rc;
1383 }
1384
1385 /*
1386  * Add a NID to a peer. Call with ln_api_mutex held.
1387  *
1388  * Error codes:
1389  *  -EPERM:    Non-DLC addition to a DLC-configured peer.
1390  *  -EEXIST:   The NID was configured by DLC for a different peer.
1391  *  -ENOMEM:   Out of memory.
1392  *  -ENOTUNIQ: Adding a second peer NID on a single network on a
1393  *             non-multi-rail peer.
1394  */
1395 static int
1396 lnet_peer_add_nid(struct lnet_peer *lp, lnet_nid_t nid, unsigned flags)
1397 {
1398         struct lnet_peer_net *lpn;
1399         struct lnet_peer_ni *lpni;
1400         int rc = 0;
1401
1402         LASSERT(lp);
1403         LASSERT(nid != LNET_NID_ANY);
1404
1405         /* A configured peer can only be updated through configuration. */
1406         if (!(flags & LNET_PEER_CONFIGURED)) {
1407                 if (lp->lp_state & LNET_PEER_CONFIGURED) {
1408                         rc = -EPERM;
1409                         goto out;
1410                 }
1411         }
1412
1413         /*
1414          * The MULTI_RAIL flag can be set but not cleared, because
1415          * that would leave the peer struct in an invalid state.
1416          */
1417         if (flags & LNET_PEER_MULTI_RAIL) {
1418                 spin_lock(&lp->lp_lock);
1419                 if (!(lp->lp_state & LNET_PEER_MULTI_RAIL)) {
1420                         lp->lp_state |= LNET_PEER_MULTI_RAIL;
1421                         lnet_peer_clr_non_mr_pref_nids(lp);
1422                 }
1423                 spin_unlock(&lp->lp_lock);
1424         } else if (lp->lp_state & LNET_PEER_MULTI_RAIL) {
1425                 rc = -EPERM;
1426                 goto out;
1427         }
1428
1429         lpni = lnet_find_peer_ni_locked(nid);
1430         if (lpni) {
1431                 /*
1432                  * A peer_ni already exists. This is only a problem if
1433                  * it is not connected to this peer and was configured
1434                  * by DLC.
1435                  */
1436                 lnet_peer_ni_decref_locked(lpni);
1437                 if (lpni->lpni_peer_net->lpn_peer == lp)
1438                         goto out;
1439                 if (lnet_peer_ni_is_configured(lpni)) {
1440                         rc = -EEXIST;
1441                         goto out;
1442                 }
1443                 /* If this is the primary NID, destroy the peer. */
1444                 if (lnet_peer_ni_is_primary(lpni)) {
1445                         struct lnet_peer *rtr_lp =
1446                           lpni->lpni_peer_net->lpn_peer;
1447                         int rtr_refcount = rtr_lp->lp_rtr_refcount;
1448                         /*
1449                          * if we're trying to delete a router it means
1450                          * we're moving this peer NI to a new peer so must
1451                          * transfer router properties to the new peer
1452                          */
1453                         if (rtr_refcount > 0) {
1454                                 flags |= LNET_PEER_RTR_NI_FORCE_DEL;
1455                                 lnet_rtr_transfer_to_peer(rtr_lp, lp);
1456                         }
1457                         lnet_peer_del(lpni->lpni_peer_net->lpn_peer);
1458                         lpni = lnet_peer_ni_alloc(nid);
1459                         if (!lpni) {
1460                                 rc = -ENOMEM;
1461                                 goto out;
1462                         }
1463                 }
1464         } else {
1465                 lpni = lnet_peer_ni_alloc(nid);
1466                 if (!lpni) {
1467                         rc = -ENOMEM;
1468                         goto out;
1469                 }
1470         }
1471
1472         /*
1473          * Get the peer_net. Check that we're not adding a second
1474          * peer_ni on a peer_net of a non-multi-rail peer.
1475          */
1476         lpn = lnet_peer_get_net_locked(lp, LNET_NIDNET(nid));
1477         if (!lpn) {
1478                 lpn = lnet_peer_net_alloc(LNET_NIDNET(nid));
1479                 if (!lpn) {
1480                         rc = -ENOMEM;
1481                         goto out_free_lpni;
1482                 }
1483         } else if (!(lp->lp_state & LNET_PEER_MULTI_RAIL)) {
1484                 rc = -ENOTUNIQ;
1485                 goto out_free_lpni;
1486         }
1487
1488         return lnet_peer_attach_peer_ni(lp, lpn, lpni, flags);
1489
1490 out_free_lpni:
1491         /* If the peer_ni was allocated above its peer_net pointer is NULL */
1492         if (!lpni->lpni_peer_net)
1493                 LIBCFS_FREE(lpni, sizeof(*lpni));
1494 out:
1495         CDEBUG(D_NET, "peer %s NID %s flags %#x: %d\n",
1496                libcfs_nid2str(lp->lp_primary_nid), libcfs_nid2str(nid),
1497                flags, rc);
1498         return rc;
1499 }
1500
1501 /*
1502  * Update the primary NID of a peer, if possible.
1503  *
1504  * Call with the lnet_api_mutex held.
1505  */
1506 static int
1507 lnet_peer_set_primary_nid(struct lnet_peer *lp, lnet_nid_t nid, unsigned flags)
1508 {
1509         lnet_nid_t old = lp->lp_primary_nid;
1510         int rc = 0;
1511
1512         if (lp->lp_primary_nid == nid)
1513                 goto out;
1514         rc = lnet_peer_add_nid(lp, nid, flags);
1515         if (rc)
1516                 goto out;
1517         lp->lp_primary_nid = nid;
1518 out:
1519         CDEBUG(D_NET, "peer %s NID %s: %d\n",
1520                libcfs_nid2str(old), libcfs_nid2str(nid), rc);
1521         return rc;
1522 }
1523
1524 /*
1525  * lpni creation initiated due to traffic either sending or receiving.
1526  */
1527 static int
1528 lnet_peer_ni_traffic_add(lnet_nid_t nid, lnet_nid_t pref)
1529 {
1530         struct lnet_peer *lp;
1531         struct lnet_peer_net *lpn;
1532         struct lnet_peer_ni *lpni;
1533         unsigned flags = 0;
1534         int rc = 0;
1535
1536         if (nid == LNET_NID_ANY) {
1537                 rc = -EINVAL;
1538                 goto out;
1539         }
1540
1541         /* lnet_net_lock is not needed here because ln_api_lock is held */
1542         lpni = lnet_find_peer_ni_locked(nid);
1543         if (lpni) {
1544                 /*
1545                  * We must have raced with another thread. Since we
1546                  * know next to nothing about a peer_ni created by
1547                  * traffic, we just assume everything is ok and
1548                  * return.
1549                  */
1550                 lnet_peer_ni_decref_locked(lpni);
1551                 goto out;
1552         }
1553
1554         /* Create peer, peer_net, and peer_ni. */
1555         rc = -ENOMEM;
1556         lp = lnet_peer_alloc(nid);
1557         if (!lp)
1558                 goto out;
1559         lpn = lnet_peer_net_alloc(LNET_NIDNET(nid));
1560         if (!lpn)
1561                 goto out_free_lp;
1562         lpni = lnet_peer_ni_alloc(nid);
1563         if (!lpni)
1564                 goto out_free_lpn;
1565         if (pref != LNET_NID_ANY)
1566                 lnet_peer_ni_set_non_mr_pref_nid(lpni, pref);
1567
1568         return lnet_peer_attach_peer_ni(lp, lpn, lpni, flags);
1569
1570 out_free_lpn:
1571         LIBCFS_FREE(lpn, sizeof(*lpn));
1572 out_free_lp:
1573         LIBCFS_FREE(lp, sizeof(*lp));
1574 out:
1575         CDEBUG(D_NET, "peer %s: %d\n", libcfs_nid2str(nid), rc);
1576         return rc;
1577 }
1578
1579 /*
1580  * Implementation of IOC_LIBCFS_ADD_PEER_NI.
1581  *
1582  * This API handles the following combinations:
1583  *   Create a peer with its primary NI if only the prim_nid is provided
1584  *   Add a NID to a peer identified by the prim_nid. The peer identified
1585  *   by the prim_nid must already exist.
1586  *   The peer being created may be non-MR.
1587  *
1588  * The caller must hold ln_api_mutex. This prevents the peer from
1589  * being created/modified/deleted by a different thread.
1590  */
1591 int
1592 lnet_add_peer_ni(lnet_nid_t prim_nid, lnet_nid_t nid, bool mr)
1593 {
1594         struct lnet_peer *lp = NULL;
1595         struct lnet_peer_ni *lpni;
1596         unsigned flags;
1597
1598         /* The prim_nid must always be specified */
1599         if (prim_nid == LNET_NID_ANY)
1600                 return -EINVAL;
1601
1602         flags = LNET_PEER_CONFIGURED;
1603         if (mr)
1604                 flags |= LNET_PEER_MULTI_RAIL;
1605
1606         /*
1607          * If nid isn't specified, we must create a new peer with
1608          * prim_nid as its primary nid.
1609          */
1610         if (nid == LNET_NID_ANY)
1611                 return lnet_peer_add(prim_nid, flags);
1612
1613         /* Look up the prim_nid, which must exist. */
1614         lpni = lnet_find_peer_ni_locked(prim_nid);
1615         if (!lpni)
1616                 return -ENOENT;
1617         lnet_peer_ni_decref_locked(lpni);
1618         lp = lpni->lpni_peer_net->lpn_peer;
1619
1620         /* Peer must have been configured. */
1621         if (!(lp->lp_state & LNET_PEER_CONFIGURED)) {
1622                 CDEBUG(D_NET, "peer %s was not configured\n",
1623                        libcfs_nid2str(prim_nid));
1624                 return -ENOENT;
1625         }
1626
1627         /* Primary NID must match */
1628         if (lp->lp_primary_nid != prim_nid) {
1629                 CDEBUG(D_NET, "prim_nid %s is not primary for peer %s\n",
1630                        libcfs_nid2str(prim_nid),
1631                        libcfs_nid2str(lp->lp_primary_nid));
1632                 return -ENODEV;
1633         }
1634
1635         /* Multi-Rail flag must match. */
1636         if ((lp->lp_state ^ flags) & LNET_PEER_MULTI_RAIL) {
1637                 CDEBUG(D_NET, "multi-rail state mismatch for peer %s\n",
1638                        libcfs_nid2str(prim_nid));
1639                 return -EPERM;
1640         }
1641
1642         return lnet_peer_add_nid(lp, nid, flags);
1643 }
1644
1645 /*
1646  * Implementation of IOC_LIBCFS_DEL_PEER_NI.
1647  *
1648  * This API handles the following combinations:
1649  *   Delete a NI from a peer if both prim_nid and nid are provided.
1650  *   Delete a peer if only prim_nid is provided.
1651  *   Delete a peer if its primary nid is provided.
1652  *
1653  * The caller must hold ln_api_mutex. This prevents the peer from
1654  * being modified/deleted by a different thread.
1655  */
1656 int
1657 lnet_del_peer_ni(lnet_nid_t prim_nid, lnet_nid_t nid)
1658 {
1659         struct lnet_peer *lp;
1660         struct lnet_peer_ni *lpni;
1661         unsigned flags;
1662
1663         if (prim_nid == LNET_NID_ANY)
1664                 return -EINVAL;
1665
1666         lpni = lnet_find_peer_ni_locked(prim_nid);
1667         if (!lpni)
1668                 return -ENOENT;
1669         lnet_peer_ni_decref_locked(lpni);
1670         lp = lpni->lpni_peer_net->lpn_peer;
1671
1672         if (prim_nid != lp->lp_primary_nid) {
1673                 CDEBUG(D_NET, "prim_nid %s is not primary for peer %s\n",
1674                        libcfs_nid2str(prim_nid),
1675                        libcfs_nid2str(lp->lp_primary_nid));
1676                 return -ENODEV;
1677         }
1678
1679         lnet_net_lock(LNET_LOCK_EX);
1680         if (lp->lp_rtr_refcount > 0) {
1681                 lnet_net_unlock(LNET_LOCK_EX);
1682                 CERROR("%s is a router. Can not be deleted\n",
1683                        libcfs_nid2str(prim_nid));
1684                 return -EBUSY;
1685         }
1686         lnet_net_unlock(LNET_LOCK_EX);
1687
1688         if (nid == LNET_NID_ANY || nid == lp->lp_primary_nid)
1689                 return lnet_peer_del(lp);
1690
1691         flags = LNET_PEER_CONFIGURED;
1692         if (lp->lp_state & LNET_PEER_MULTI_RAIL)
1693                 flags |= LNET_PEER_MULTI_RAIL;
1694
1695         return lnet_peer_del_nid(lp, nid, flags);
1696 }
1697
1698 void
1699 lnet_destroy_peer_ni_locked(struct lnet_peer_ni *lpni)
1700 {
1701         struct lnet_peer_table *ptable;
1702         struct lnet_peer_net *lpn;
1703
1704         CDEBUG(D_NET, "%p nid %s\n", lpni, libcfs_nid2str(lpni->lpni_nid));
1705
1706         LASSERT(atomic_read(&lpni->lpni_refcount) == 0);
1707         LASSERT(list_empty(&lpni->lpni_txq));
1708         LASSERT(lpni->lpni_txqnob == 0);
1709         LASSERT(list_empty(&lpni->lpni_peer_nis));
1710         LASSERT(list_empty(&lpni->lpni_on_remote_peer_ni_list));
1711
1712         lpn = lpni->lpni_peer_net;
1713         lpni->lpni_peer_net = NULL;
1714         lpni->lpni_net = NULL;
1715
1716         /* remove the peer ni from the zombie list */
1717         ptable = the_lnet.ln_peer_tables[lpni->lpni_cpt];
1718         spin_lock(&ptable->pt_zombie_lock);
1719         list_del_init(&lpni->lpni_hashlist);
1720         ptable->pt_zombies--;
1721         spin_unlock(&ptable->pt_zombie_lock);
1722
1723         if (lpni->lpni_pref_nnids > 1) {
1724                 LIBCFS_FREE(lpni->lpni_pref.nids,
1725                         sizeof(*lpni->lpni_pref.nids) * lpni->lpni_pref_nnids);
1726         }
1727         LIBCFS_FREE(lpni, sizeof(*lpni));
1728
1729         lnet_peer_net_decref_locked(lpn);
1730 }
1731
1732 struct lnet_peer_ni *
1733 lnet_nid2peerni_ex(lnet_nid_t nid, int cpt)
1734 {
1735         struct lnet_peer_ni *lpni = NULL;
1736         int rc;
1737
1738         if (the_lnet.ln_state != LNET_STATE_RUNNING)
1739                 return ERR_PTR(-ESHUTDOWN);
1740
1741         /*
1742          * find if a peer_ni already exists.
1743          * If so then just return that.
1744          */
1745         lpni = lnet_find_peer_ni_locked(nid);
1746         if (lpni)
1747                 return lpni;
1748
1749         lnet_net_unlock(cpt);
1750
1751         rc = lnet_peer_ni_traffic_add(nid, LNET_NID_ANY);
1752         if (rc) {
1753                 lpni = ERR_PTR(rc);
1754                 goto out_net_relock;
1755         }
1756
1757         lpni = lnet_find_peer_ni_locked(nid);
1758         LASSERT(lpni);
1759
1760 out_net_relock:
1761         lnet_net_lock(cpt);
1762
1763         return lpni;
1764 }
1765
1766 /*
1767  * Get a peer_ni for the given nid, create it if necessary. Takes a
1768  * hold on the peer_ni.
1769  */
1770 struct lnet_peer_ni *
1771 lnet_nid2peerni_locked(lnet_nid_t nid, lnet_nid_t pref, int cpt)
1772 {
1773         struct lnet_peer_ni *lpni = NULL;
1774         int rc;
1775
1776         if (the_lnet.ln_state != LNET_STATE_RUNNING)
1777                 return ERR_PTR(-ESHUTDOWN);
1778
1779         /*
1780          * find if a peer_ni already exists.
1781          * If so then just return that.
1782          */
1783         lpni = lnet_find_peer_ni_locked(nid);
1784         if (lpni)
1785                 return lpni;
1786
1787         /*
1788          * Slow path:
1789          * use the lnet_api_mutex to serialize the creation of the peer_ni
1790          * and the creation/deletion of the local ni/net. When a local ni is
1791          * created, if there exists a set of peer_nis on that network,
1792          * they need to be traversed and updated. When a local NI is
1793          * deleted, which could result in a network being deleted, then
1794          * all peer nis on that network need to be removed as well.
1795          *
1796          * Creation through traffic should also be serialized with
1797          * creation through DLC.
1798          */
1799         lnet_net_unlock(cpt);
1800         mutex_lock(&the_lnet.ln_api_mutex);
1801         /*
1802          * Shutdown is only set under the ln_api_lock, so a single
1803          * check here is sufficent.
1804          */
1805         if (the_lnet.ln_state != LNET_STATE_RUNNING) {
1806                 lpni = ERR_PTR(-ESHUTDOWN);
1807                 goto out_mutex_unlock;
1808         }
1809
1810         rc = lnet_peer_ni_traffic_add(nid, pref);
1811         if (rc) {
1812                 lpni = ERR_PTR(rc);
1813                 goto out_mutex_unlock;
1814         }
1815
1816         lpni = lnet_find_peer_ni_locked(nid);
1817         LASSERT(lpni);
1818
1819 out_mutex_unlock:
1820         mutex_unlock(&the_lnet.ln_api_mutex);
1821         lnet_net_lock(cpt);
1822
1823         /* Lock has been dropped, check again for shutdown. */
1824         if (the_lnet.ln_state != LNET_STATE_RUNNING) {
1825                 if (!IS_ERR(lpni))
1826                         lnet_peer_ni_decref_locked(lpni);
1827                 lpni = ERR_PTR(-ESHUTDOWN);
1828         }
1829
1830         return lpni;
1831 }
1832
1833 bool
1834 lnet_peer_gw_discovery(struct lnet_peer *lp)
1835 {
1836         bool rc = false;
1837
1838         spin_lock(&lp->lp_lock);
1839         if (lp->lp_state & LNET_PEER_RTR_DISCOVERY)
1840                 rc = true;
1841         spin_unlock(&lp->lp_lock);
1842
1843         return rc;
1844 }
1845
1846 bool
1847 lnet_peer_is_uptodate(struct lnet_peer *lp)
1848 {
1849         bool rc;
1850
1851         spin_lock(&lp->lp_lock);
1852         rc = lnet_peer_is_uptodate_locked(lp);
1853         spin_unlock(&lp->lp_lock);
1854         return rc;
1855 }
1856
1857 /*
1858  * Is a peer uptodate from the point of view of discovery?
1859  *
1860  * If it is currently being processed, obviously not.
1861  * A forced Ping or Push is also handled by the discovery thread.
1862  *
1863  * Otherwise look at whether the peer needs rediscovering.
1864  */
1865 bool
1866 lnet_peer_is_uptodate_locked(struct lnet_peer *lp)
1867 __must_hold(&lp->lp_lock)
1868 {
1869         bool rc;
1870
1871         if (lp->lp_state & (LNET_PEER_DISCOVERING |
1872                             LNET_PEER_FORCE_PING |
1873                             LNET_PEER_FORCE_PUSH)) {
1874                 rc = false;
1875         } else if (lp->lp_state & LNET_PEER_REDISCOVER) {
1876                 rc = false;
1877         } else if (lnet_peer_needs_push(lp)) {
1878                 rc = false;
1879         } else if (lp->lp_state & LNET_PEER_DISCOVERED) {
1880                 if (lp->lp_state & LNET_PEER_NIDS_UPTODATE)
1881                         rc = true;
1882                 else
1883                         rc = false;
1884         } else {
1885                 rc = false;
1886         }
1887
1888         return rc;
1889 }
1890
1891 /*
1892  * Queue a peer for the attention of the discovery thread.  Call with
1893  * lnet_net_lock/EX held. Returns 0 if the peer was queued, and
1894  * -EALREADY if the peer was already queued.
1895  */
1896 static int lnet_peer_queue_for_discovery(struct lnet_peer *lp)
1897 {
1898         int rc;
1899
1900         spin_lock(&lp->lp_lock);
1901         if (!(lp->lp_state & LNET_PEER_DISCOVERING))
1902                 lp->lp_state |= LNET_PEER_DISCOVERING;
1903         spin_unlock(&lp->lp_lock);
1904         if (list_empty(&lp->lp_dc_list)) {
1905                 lnet_peer_addref_locked(lp);
1906                 list_add_tail(&lp->lp_dc_list, &the_lnet.ln_dc_request);
1907                 wake_up(&the_lnet.ln_dc_waitq);
1908                 rc = 0;
1909         } else {
1910                 rc = -EALREADY;
1911         }
1912
1913         CDEBUG(D_NET, "Queue peer %s: %d\n",
1914                libcfs_nid2str(lp->lp_primary_nid), rc);
1915
1916         return rc;
1917 }
1918
1919 /*
1920  * Discovery of a peer is complete. Wake all waiters on the peer.
1921  * Call with lnet_net_lock/EX held.
1922  */
1923 static void lnet_peer_discovery_complete(struct lnet_peer *lp)
1924 {
1925         struct lnet_msg *msg, *tmp;
1926         int rc = 0;
1927         struct list_head pending_msgs;
1928
1929         INIT_LIST_HEAD(&pending_msgs);
1930
1931         CDEBUG(D_NET, "Discovery complete. Dequeue peer %s\n",
1932                libcfs_nid2str(lp->lp_primary_nid));
1933
1934         list_del_init(&lp->lp_dc_list);
1935         spin_lock(&lp->lp_lock);
1936         list_splice_init(&lp->lp_dc_pendq, &pending_msgs);
1937         spin_unlock(&lp->lp_lock);
1938         wake_up_all(&lp->lp_dc_waitq);
1939
1940         if (lp->lp_rtr_refcount > 0)
1941                 lnet_router_discovery_complete(lp);
1942
1943         lnet_net_unlock(LNET_LOCK_EX);
1944
1945         /* iterate through all pending messages and send them again */
1946         list_for_each_entry_safe(msg, tmp, &pending_msgs, msg_list) {
1947                 list_del_init(&msg->msg_list);
1948                 if (lp->lp_dc_error) {
1949                         lnet_finalize(msg, lp->lp_dc_error);
1950                         continue;
1951                 }
1952
1953                 CDEBUG(D_NET, "sending pending message %s to target %s\n",
1954                        lnet_msgtyp2str(msg->msg_type),
1955                        libcfs_id2str(msg->msg_target));
1956                 rc = lnet_send(msg->msg_src_nid_param, msg,
1957                                msg->msg_rtr_nid_param);
1958                 if (rc < 0) {
1959                         CNETERR("Error sending %s to %s: %d\n",
1960                                lnet_msgtyp2str(msg->msg_type),
1961                                libcfs_id2str(msg->msg_target), rc);
1962                         lnet_finalize(msg, rc);
1963                 }
1964         }
1965         lnet_net_lock(LNET_LOCK_EX);
1966         lnet_peer_decref_locked(lp);
1967 }
1968
1969 /*
1970  * Handle inbound push.
1971  * Like any event handler, called with lnet_res_lock/CPT held.
1972  */
1973 void lnet_peer_push_event(struct lnet_event *ev)
1974 {
1975         struct lnet_ping_buffer *pbuf = ev->md.user_ptr;
1976         struct lnet_peer *lp;
1977
1978         /* lnet_find_peer() adds a refcount */
1979         lp = lnet_find_peer(ev->source.nid);
1980         if (!lp) {
1981                 CDEBUG(D_NET, "Push Put from unknown %s (source %s). Ignoring...\n",
1982                        libcfs_nid2str(ev->initiator.nid),
1983                        libcfs_nid2str(ev->source.nid));
1984                 return;
1985         }
1986
1987         /* Ensure peer state remains consistent while we modify it. */
1988         spin_lock(&lp->lp_lock);
1989
1990         /*
1991          * If some kind of error happened the contents of the message
1992          * cannot be used. Clear the NIDS_UPTODATE and set the
1993          * FORCE_PING flag to trigger a ping.
1994          */
1995         if (ev->status) {
1996                 lp->lp_state &= ~LNET_PEER_NIDS_UPTODATE;
1997                 lp->lp_state |= LNET_PEER_FORCE_PING;
1998                 CDEBUG(D_NET, "Push Put error %d from %s (source %s)\n",
1999                        ev->status,
2000                        libcfs_nid2str(lp->lp_primary_nid),
2001                        libcfs_nid2str(ev->source.nid));
2002                 goto out;
2003         }
2004
2005         /*
2006          * A push with invalid or corrupted info. Clear the UPTODATE
2007          * flag to trigger a ping.
2008          */
2009         if (lnet_ping_info_validate(&pbuf->pb_info)) {
2010                 lp->lp_state &= ~LNET_PEER_NIDS_UPTODATE;
2011                 lp->lp_state |= LNET_PEER_FORCE_PING;
2012                 CDEBUG(D_NET, "Corrupted Push from %s\n",
2013                        libcfs_nid2str(lp->lp_primary_nid));
2014                 goto out;
2015         }
2016
2017         /*
2018          * Make sure we'll allocate the correct size ping buffer when
2019          * pinging the peer.
2020          */
2021         if (lp->lp_data_nnis < pbuf->pb_info.pi_nnis)
2022                 lp->lp_data_nnis = pbuf->pb_info.pi_nnis;
2023
2024         /*
2025          * A non-Multi-Rail peer is not supposed to be capable of
2026          * sending a push.
2027          */
2028         if (!(pbuf->pb_info.pi_features & LNET_PING_FEAT_MULTI_RAIL)) {
2029                 CERROR("Push from non-Multi-Rail peer %s dropped\n",
2030                        libcfs_nid2str(lp->lp_primary_nid));
2031                 goto out;
2032         }
2033
2034         /*
2035          * Check the MULTIRAIL flag. Complain if the peer was DLC
2036          * configured without it.
2037          */
2038         if (!(lp->lp_state & LNET_PEER_MULTI_RAIL)) {
2039                 if (lp->lp_state & LNET_PEER_CONFIGURED) {
2040                         CERROR("Push says %s is Multi-Rail, DLC says not\n",
2041                                libcfs_nid2str(lp->lp_primary_nid));
2042                 } else {
2043                         lp->lp_state |= LNET_PEER_MULTI_RAIL;
2044                         lnet_peer_clr_non_mr_pref_nids(lp);
2045                 }
2046         }
2047
2048         /*
2049          * The peer may have discovery disabled at its end. Set
2050          * NO_DISCOVERY as appropriate.
2051          */
2052         if (!(pbuf->pb_info.pi_features & LNET_PING_FEAT_DISCOVERY)) {
2053                 CDEBUG(D_NET, "Peer %s has discovery disabled\n",
2054                        libcfs_nid2str(lp->lp_primary_nid));
2055                 lp->lp_state |= LNET_PEER_NO_DISCOVERY;
2056         } else if (lp->lp_state & LNET_PEER_NO_DISCOVERY) {
2057                 CDEBUG(D_NET, "Peer %s has discovery enabled\n",
2058                        libcfs_nid2str(lp->lp_primary_nid));
2059                 lp->lp_state &= ~LNET_PEER_NO_DISCOVERY;
2060         }
2061
2062         /*
2063          * Check for truncation of the Put message. Clear the
2064          * NIDS_UPTODATE flag and set FORCE_PING to trigger a ping,
2065          * and tell discovery to allocate a bigger buffer.
2066          */
2067         if (pbuf->pb_nnis < pbuf->pb_info.pi_nnis) {
2068                 if (the_lnet.ln_push_target_nnis < pbuf->pb_info.pi_nnis)
2069                         the_lnet.ln_push_target_nnis = pbuf->pb_info.pi_nnis;
2070                 lp->lp_state &= ~LNET_PEER_NIDS_UPTODATE;
2071                 lp->lp_state |= LNET_PEER_FORCE_PING;
2072                 CDEBUG(D_NET, "Truncated Push from %s (%d nids)\n",
2073                        libcfs_nid2str(lp->lp_primary_nid),
2074                        pbuf->pb_info.pi_nnis);
2075                 goto out;
2076         }
2077
2078         /* always assume new data */
2079         lp->lp_peer_seqno = LNET_PING_BUFFER_SEQNO(pbuf);
2080         lp->lp_state &= ~LNET_PEER_NIDS_UPTODATE;
2081
2082         /*
2083          * If there is data present that hasn't been processed yet,
2084          * we'll replace it if the Put contained newer data and it
2085          * fits. We're racing with a Ping or earlier Push in this
2086          * case.
2087          */
2088         if (lp->lp_state & LNET_PEER_DATA_PRESENT) {
2089                 if (LNET_PING_BUFFER_SEQNO(pbuf) >
2090                         LNET_PING_BUFFER_SEQNO(lp->lp_data) &&
2091                     pbuf->pb_info.pi_nnis <= lp->lp_data->pb_nnis) {
2092                         memcpy(&lp->lp_data->pb_info, &pbuf->pb_info,
2093                                LNET_PING_INFO_SIZE(pbuf->pb_info.pi_nnis));
2094                         CDEBUG(D_NET, "Ping/Push race from %s: %u vs %u\n",
2095                               libcfs_nid2str(lp->lp_primary_nid),
2096                               LNET_PING_BUFFER_SEQNO(pbuf),
2097                               LNET_PING_BUFFER_SEQNO(lp->lp_data));
2098                 }
2099                 goto out;
2100         }
2101
2102         /*
2103          * Allocate a buffer to copy the data. On a failure we drop
2104          * the Push and set FORCE_PING to force the discovery
2105          * thread to fix the problem by pinging the peer.
2106          */
2107         lp->lp_data = lnet_ping_buffer_alloc(lp->lp_data_nnis, GFP_ATOMIC);
2108         if (!lp->lp_data) {
2109                 lp->lp_state |= LNET_PEER_FORCE_PING;
2110                 CDEBUG(D_NET, "Cannot allocate Push buffer for %s %u\n",
2111                        libcfs_nid2str(lp->lp_primary_nid),
2112                        LNET_PING_BUFFER_SEQNO(pbuf));
2113                 goto out;
2114         }
2115
2116         /* Success */
2117         memcpy(&lp->lp_data->pb_info, &pbuf->pb_info,
2118                LNET_PING_INFO_SIZE(pbuf->pb_info.pi_nnis));
2119         lp->lp_state |= LNET_PEER_DATA_PRESENT;
2120         CDEBUG(D_NET, "Received Push %s %u\n",
2121                libcfs_nid2str(lp->lp_primary_nid),
2122                LNET_PING_BUFFER_SEQNO(pbuf));
2123
2124 out:
2125         /*
2126          * Queue the peer for discovery if not done, force it on the request
2127          * queue and wake the discovery thread if the peer was already queued,
2128          * because its status changed.
2129          */
2130         spin_unlock(&lp->lp_lock);
2131         lnet_net_lock(LNET_LOCK_EX);
2132         if (!lnet_peer_is_uptodate(lp) && lnet_peer_queue_for_discovery(lp)) {
2133                 list_move(&lp->lp_dc_list, &the_lnet.ln_dc_request);
2134                 wake_up(&the_lnet.ln_dc_waitq);
2135         }
2136         /* Drop refcount from lookup */
2137         lnet_peer_decref_locked(lp);
2138         lnet_net_unlock(LNET_LOCK_EX);
2139 }
2140
2141 /*
2142  * Clear the discovery error state, unless we're already discovering
2143  * this peer, in which case the error is current.
2144  */
2145 static void lnet_peer_clear_discovery_error(struct lnet_peer *lp)
2146 {
2147         spin_lock(&lp->lp_lock);
2148         if (!(lp->lp_state & LNET_PEER_DISCOVERING))
2149                 lp->lp_dc_error = 0;
2150         spin_unlock(&lp->lp_lock);
2151 }
2152
2153 /*
2154  * Peer discovery slow path. The ln_api_mutex is held on entry, and
2155  * dropped/retaken within this function. An lnet_peer_ni is passed in
2156  * because discovery could tear down an lnet_peer.
2157  */
2158 int
2159 lnet_discover_peer_locked(struct lnet_peer_ni *lpni, int cpt, bool block)
2160 {
2161         DEFINE_WAIT(wait);
2162         struct lnet_peer *lp;
2163         int rc = 0;
2164         int count = 0;
2165
2166 again:
2167         lnet_net_unlock(cpt);
2168         lnet_net_lock(LNET_LOCK_EX);
2169         lp = lpni->lpni_peer_net->lpn_peer;
2170         lnet_peer_clear_discovery_error(lp);
2171
2172         /*
2173          * We're willing to be interrupted. The lpni can become a
2174          * zombie if we race with DLC, so we must check for that.
2175          */
2176         for (;;) {
2177                 /* Keep lp alive when the lnet_net_lock is unlocked */
2178                 lnet_peer_addref_locked(lp);
2179                 prepare_to_wait(&lp->lp_dc_waitq, &wait, TASK_INTERRUPTIBLE);
2180                 if (signal_pending(current))
2181                         break;
2182                 if (the_lnet.ln_dc_state != LNET_DC_STATE_RUNNING)
2183                         break;
2184                 /*
2185                  * Don't repeat discovery if discovery is disabled. This is
2186                  * done to ensure we can use discovery as a standard ping as
2187                  * well for backwards compatibility with routers which do not
2188                  * have discovery or have discovery disabled
2189                  */
2190                 if (lnet_is_discovery_disabled(lp) && count > 0)
2191                         break;
2192                 if (lp->lp_dc_error)
2193                         break;
2194                 if (lnet_peer_is_uptodate(lp))
2195                         break;
2196                 lnet_peer_queue_for_discovery(lp);
2197                 count++;
2198                 CDEBUG(D_NET, "Discovery attempt # %d\n", count);
2199
2200                 /*
2201                  * If caller requested a non-blocking operation then
2202                  * return immediately. Once discovery is complete any
2203                  * pending messages that were stopped due to discovery
2204                  * will be transmitted.
2205                  */
2206                 if (!block)
2207                         break;
2208
2209                 lnet_net_unlock(LNET_LOCK_EX);
2210                 schedule();
2211                 finish_wait(&lp->lp_dc_waitq, &wait);
2212                 lnet_net_lock(LNET_LOCK_EX);
2213                 lnet_peer_decref_locked(lp);
2214                 /* Peer may have changed */
2215                 lp = lpni->lpni_peer_net->lpn_peer;
2216         }
2217         finish_wait(&lp->lp_dc_waitq, &wait);
2218
2219         lnet_net_unlock(LNET_LOCK_EX);
2220         lnet_net_lock(cpt);
2221         lnet_peer_decref_locked(lp);
2222         /*
2223          * The peer may have changed, so re-check and rediscover if that turns
2224          * out to have been the case. The reference count on lp ensured that
2225          * even if it was unlinked from lpni the memory could not be recycled.
2226          * Thus the check below is sufficient to determine whether the peer
2227          * changed. If the peer changed, then lp must not be dereferenced.
2228          */
2229         if (lp != lpni->lpni_peer_net->lpn_peer)
2230                 goto again;
2231
2232         if (signal_pending(current))
2233                 rc = -EINTR;
2234         else if (the_lnet.ln_dc_state != LNET_DC_STATE_RUNNING)
2235                 rc = -ESHUTDOWN;
2236         else if (lp->lp_dc_error)
2237                 rc = lp->lp_dc_error;
2238         else if (!block)
2239                 CDEBUG(D_NET, "non-blocking discovery\n");
2240         else if (!lnet_peer_is_uptodate(lp) && !lnet_is_discovery_disabled(lp))
2241                 goto again;
2242
2243         CDEBUG(D_NET, "peer %s NID %s: %d. %s\n",
2244                (lp ? libcfs_nid2str(lp->lp_primary_nid) : "(none)"),
2245                libcfs_nid2str(lpni->lpni_nid), rc,
2246                (!block) ? "pending discovery" : "discovery complete");
2247
2248         return rc;
2249 }
2250
2251 /* Handle an incoming ack for a push. */
2252 static void
2253 lnet_discovery_event_ack(struct lnet_peer *lp, struct lnet_event *ev)
2254 {
2255         struct lnet_ping_buffer *pbuf;
2256
2257         pbuf = LNET_PING_INFO_TO_BUFFER(ev->md.start);
2258         spin_lock(&lp->lp_lock);
2259         lp->lp_state &= ~LNET_PEER_PUSH_SENT;
2260         lp->lp_push_error = ev->status;
2261         if (ev->status)
2262                 lp->lp_state |= LNET_PEER_PUSH_FAILED;
2263         else
2264                 lp->lp_node_seqno = LNET_PING_BUFFER_SEQNO(pbuf);
2265         spin_unlock(&lp->lp_lock);
2266
2267         CDEBUG(D_NET, "peer %s ev->status %d\n",
2268                libcfs_nid2str(lp->lp_primary_nid), ev->status);
2269 }
2270
2271 /* Handle a Reply message. This is the reply to a Ping message. */
2272 static void
2273 lnet_discovery_event_reply(struct lnet_peer *lp, struct lnet_event *ev)
2274 {
2275         struct lnet_ping_buffer *pbuf;
2276         int rc;
2277
2278         spin_lock(&lp->lp_lock);
2279
2280         /*
2281          * If some kind of error happened the contents of message
2282          * cannot be used. Set PING_FAILED to trigger a retry.
2283          */
2284         if (ev->status) {
2285                 lp->lp_state |= LNET_PEER_PING_FAILED;
2286                 lp->lp_ping_error = ev->status;
2287                 CDEBUG(D_NET, "Ping Reply error %d from %s (source %s)\n",
2288                        ev->status,
2289                        libcfs_nid2str(lp->lp_primary_nid),
2290                        libcfs_nid2str(ev->source.nid));
2291                 goto out;
2292         }
2293
2294         pbuf = LNET_PING_INFO_TO_BUFFER(ev->md.start);
2295         if (pbuf->pb_info.pi_magic == __swab32(LNET_PROTO_PING_MAGIC))
2296                 lnet_swap_pinginfo(pbuf);
2297
2298         /*
2299          * A reply with invalid or corrupted info. Set PING_FAILED to
2300          * trigger a retry.
2301          */
2302         rc = lnet_ping_info_validate(&pbuf->pb_info);
2303         if (rc) {
2304                 lp->lp_state |= LNET_PEER_PING_FAILED;
2305                 lp->lp_ping_error = 0;
2306                 CDEBUG(D_NET, "Corrupted Ping Reply from %s: %d\n",
2307                        libcfs_nid2str(lp->lp_primary_nid), rc);
2308                 goto out;
2309         }
2310
2311
2312         /*
2313          * The peer may have discovery disabled at its end. Set
2314          * NO_DISCOVERY as appropriate.
2315          */
2316         if ((pbuf->pb_info.pi_features & LNET_PING_FEAT_DISCOVERY) &&
2317             !lnet_peer_discovery_disabled) {
2318                 CDEBUG(D_NET, "Peer %s has discovery enabled\n",
2319                        libcfs_nid2str(lp->lp_primary_nid));
2320                 lp->lp_state &= ~LNET_PEER_NO_DISCOVERY;
2321         } else {
2322                 CDEBUG(D_NET, "Peer %s has discovery disabled\n",
2323                        libcfs_nid2str(lp->lp_primary_nid));
2324                 lp->lp_state |= LNET_PEER_NO_DISCOVERY;
2325         }
2326
2327         /*
2328          * Update the MULTI_RAIL flag based on the reply. If the peer
2329          * was configured with DLC then the setting should match what
2330          * DLC put in.
2331          */
2332         if (pbuf->pb_info.pi_features & LNET_PING_FEAT_MULTI_RAIL) {
2333                 if (lp->lp_state & LNET_PEER_MULTI_RAIL) {
2334                         CDEBUG(D_NET, "peer %s(%p) is MR\n",
2335                                libcfs_nid2str(lp->lp_primary_nid), lp);
2336                 } else if (lp->lp_state & LNET_PEER_CONFIGURED) {
2337                         CWARN("Reply says %s is Multi-Rail, DLC says not\n",
2338                               libcfs_nid2str(lp->lp_primary_nid));
2339                 } else if (lnet_peer_discovery_disabled) {
2340                         CDEBUG(D_NET,
2341                                "peer %s(%p) not MR: DD disabled locally\n",
2342                                libcfs_nid2str(lp->lp_primary_nid), lp);
2343                 } else if (lp->lp_state & LNET_PEER_NO_DISCOVERY) {
2344                         CDEBUG(D_NET,
2345                                "peer %s(%p) not MR: DD disabled remotely\n",
2346                                libcfs_nid2str(lp->lp_primary_nid), lp);
2347                 } else {
2348                         CDEBUG(D_NET, "peer %s(%p) is MR capable\n",
2349                                libcfs_nid2str(lp->lp_primary_nid), lp);
2350                         lp->lp_state |= LNET_PEER_MULTI_RAIL;
2351                         lnet_peer_clr_non_mr_pref_nids(lp);
2352                 }
2353         } else if (lp->lp_state & LNET_PEER_MULTI_RAIL) {
2354                 if (lp->lp_state & LNET_PEER_CONFIGURED) {
2355                         CWARN("DLC says %s is Multi-Rail, Reply says not\n",
2356                               libcfs_nid2str(lp->lp_primary_nid));
2357                 } else {
2358                         CERROR("Multi-Rail state vanished from %s\n",
2359                                libcfs_nid2str(lp->lp_primary_nid));
2360                         lp->lp_state &= ~LNET_PEER_MULTI_RAIL;
2361                 }
2362         }
2363
2364         /*
2365          * Make sure we'll allocate the correct size ping buffer when
2366          * pinging the peer.
2367          */
2368         if (lp->lp_data_nnis < pbuf->pb_info.pi_nnis)
2369                 lp->lp_data_nnis = pbuf->pb_info.pi_nnis;
2370
2371         /*
2372          * Check for truncation of the Reply. Clear PING_SENT and set
2373          * PING_FAILED to trigger a retry.
2374          */
2375         if (pbuf->pb_nnis < pbuf->pb_info.pi_nnis) {
2376                 if (the_lnet.ln_push_target_nnis < pbuf->pb_info.pi_nnis)
2377                         the_lnet.ln_push_target_nnis = pbuf->pb_info.pi_nnis;
2378                 lp->lp_state |= LNET_PEER_PING_FAILED;
2379                 lp->lp_ping_error = 0;
2380                 CDEBUG(D_NET, "Truncated Reply from %s (%d nids)\n",
2381                        libcfs_nid2str(lp->lp_primary_nid),
2382                        pbuf->pb_info.pi_nnis);
2383                 goto out;
2384         }
2385
2386         /*
2387          * Check the sequence numbers in the reply. These are only
2388          * available if the reply came from a Multi-Rail peer.
2389          */
2390         if (pbuf->pb_info.pi_features & LNET_PING_FEAT_MULTI_RAIL &&
2391             pbuf->pb_info.pi_nnis > 1 &&
2392             lp->lp_primary_nid == pbuf->pb_info.pi_ni[1].ns_nid) {
2393                 if (LNET_PING_BUFFER_SEQNO(pbuf) < lp->lp_peer_seqno)
2394                         CDEBUG(D_NET, "peer %s: seq# got %u have %u. peer rebooted?\n",
2395                                 libcfs_nid2str(lp->lp_primary_nid),
2396                                 LNET_PING_BUFFER_SEQNO(pbuf),
2397                                 lp->lp_peer_seqno);
2398
2399                 lp->lp_peer_seqno = LNET_PING_BUFFER_SEQNO(pbuf);
2400         }
2401
2402         /* We're happy with the state of the data in the buffer. */
2403         CDEBUG(D_NET, "peer %s data present %u. state = 0x%x\n",
2404                libcfs_nid2str(lp->lp_primary_nid), lp->lp_peer_seqno, lp->lp_state);
2405         if (lp->lp_state & LNET_PEER_DATA_PRESENT)
2406                 lnet_ping_buffer_decref(lp->lp_data);
2407         else
2408                 lp->lp_state |= LNET_PEER_DATA_PRESENT;
2409         lnet_ping_buffer_addref(pbuf);
2410         lp->lp_data = pbuf;
2411 out:
2412         lp->lp_state &= ~LNET_PEER_PING_SENT;
2413         spin_unlock(&lp->lp_lock);
2414
2415         lnet_net_lock(LNET_LOCK_EX);
2416         /*
2417          * If this peer is a gateway, call the routing callback to
2418          * handle the ping reply
2419          */
2420         if (lp->lp_rtr_refcount > 0)
2421                 lnet_router_discovery_ping_reply(lp);
2422         lnet_net_unlock(LNET_LOCK_EX);
2423 }
2424
2425 /*
2426  * Send event handling. Only matters for error cases, where we clean
2427  * up state on the peer and peer_ni that would otherwise be updated in
2428  * the REPLY event handler for a successful Ping, and the ACK event
2429  * handler for a successful Push.
2430  */
2431 static int
2432 lnet_discovery_event_send(struct lnet_peer *lp, struct lnet_event *ev)
2433 {
2434         int rc = 0;
2435
2436         if (!ev->status)
2437                 goto out;
2438
2439         spin_lock(&lp->lp_lock);
2440         if (ev->msg_type == LNET_MSG_GET) {
2441                 lp->lp_state &= ~LNET_PEER_PING_SENT;
2442                 lp->lp_state |= LNET_PEER_PING_FAILED;
2443                 lp->lp_ping_error = ev->status;
2444         } else { /* ev->msg_type == LNET_MSG_PUT */
2445                 lp->lp_state &= ~LNET_PEER_PUSH_SENT;
2446                 lp->lp_state |= LNET_PEER_PUSH_FAILED;
2447                 lp->lp_push_error = ev->status;
2448         }
2449         spin_unlock(&lp->lp_lock);
2450         rc = LNET_REDISCOVER_PEER;
2451 out:
2452         CDEBUG(D_NET, "%s Send to %s: %d\n",
2453                 (ev->msg_type == LNET_MSG_GET ? "Ping" : "Push"),
2454                 libcfs_nid2str(ev->target.nid), rc);
2455         return rc;
2456 }
2457
2458 /*
2459  * Unlink event handling. This event is only seen if a call to
2460  * LNetMDUnlink() caused the event to be unlinked. If this call was
2461  * made after the event was set up in LNetGet() or LNetPut() then we
2462  * assume the Ping or Push timed out.
2463  */
2464 static void
2465 lnet_discovery_event_unlink(struct lnet_peer *lp, struct lnet_event *ev)
2466 {
2467         spin_lock(&lp->lp_lock);
2468         /* We've passed through LNetGet() */
2469         if (lp->lp_state & LNET_PEER_PING_SENT) {
2470                 lp->lp_state &= ~LNET_PEER_PING_SENT;
2471                 lp->lp_state |= LNET_PEER_PING_FAILED;
2472                 lp->lp_ping_error = -ETIMEDOUT;
2473                 CDEBUG(D_NET, "Ping Unlink for message to peer %s\n",
2474                         libcfs_nid2str(lp->lp_primary_nid));
2475         }
2476         /* We've passed through LNetPut() */
2477         if (lp->lp_state & LNET_PEER_PUSH_SENT) {
2478                 lp->lp_state &= ~LNET_PEER_PUSH_SENT;
2479                 lp->lp_state |= LNET_PEER_PUSH_FAILED;
2480                 lp->lp_push_error = -ETIMEDOUT;
2481                 CDEBUG(D_NET, "Push Unlink for message to peer %s\n",
2482                         libcfs_nid2str(lp->lp_primary_nid));
2483         }
2484         spin_unlock(&lp->lp_lock);
2485 }
2486
2487 /*
2488  * Event handler for the discovery EQ.
2489  *
2490  * Called with lnet_res_lock(cpt) held. The cpt is the
2491  * lnet_cpt_of_cookie() of the md handle cookie.
2492  */
2493 static void lnet_discovery_event_handler(struct lnet_event *event)
2494 {
2495         struct lnet_peer *lp = event->md.user_ptr;
2496         struct lnet_ping_buffer *pbuf;
2497         int rc;
2498
2499         /* discovery needs to take another look */
2500         rc = LNET_REDISCOVER_PEER;
2501
2502         CDEBUG(D_NET, "Received event: %d\n", event->type);
2503
2504         switch (event->type) {
2505         case LNET_EVENT_ACK:
2506                 lnet_discovery_event_ack(lp, event);
2507                 break;
2508         case LNET_EVENT_REPLY:
2509                 lnet_discovery_event_reply(lp, event);
2510                 break;
2511         case LNET_EVENT_SEND:
2512                 /* Only send failure triggers a retry. */
2513                 rc = lnet_discovery_event_send(lp, event);
2514                 break;
2515         case LNET_EVENT_UNLINK:
2516                 /* LNetMDUnlink() was called */
2517                 lnet_discovery_event_unlink(lp, event);
2518                 break;
2519         default:
2520                 /* Invalid events. */
2521                 LBUG();
2522         }
2523         lnet_net_lock(LNET_LOCK_EX);
2524         if (event->unlinked) {
2525                 pbuf = LNET_PING_INFO_TO_BUFFER(event->md.start);
2526                 lnet_ping_buffer_decref(pbuf);
2527                 lnet_peer_decref_locked(lp);
2528         }
2529
2530         /* put peer back at end of request queue, if discovery not already
2531          * done */
2532         if (rc == LNET_REDISCOVER_PEER && !lnet_peer_is_uptodate(lp)) {
2533                 list_move_tail(&lp->lp_dc_list, &the_lnet.ln_dc_request);
2534                 wake_up(&the_lnet.ln_dc_waitq);
2535         }
2536         lnet_net_unlock(LNET_LOCK_EX);
2537 }
2538
2539 /*
2540  * Build a peer from incoming data.
2541  *
2542  * The NIDs in the incoming data are supposed to be structured as follows:
2543  *  - loopback
2544  *  - primary NID
2545  *  - other NIDs in same net
2546  *  - NIDs in second net
2547  *  - NIDs in third net
2548  *  - ...
2549  * This due to the way the list of NIDs in the data is created.
2550  *
2551  * Note that this function will mark the peer uptodate unless an
2552  * ENOMEM is encontered. All other errors are due to a conflict
2553  * between the DLC configuration and what discovery sees. We treat DLC
2554  * as binding, and therefore set the NIDS_UPTODATE flag to prevent the
2555  * peer from becoming stuck in discovery.
2556  */
2557 static int lnet_peer_merge_data(struct lnet_peer *lp,
2558                                 struct lnet_ping_buffer *pbuf)
2559 {
2560         struct lnet_peer_ni *lpni;
2561         lnet_nid_t *curnis = NULL;
2562         struct lnet_ni_status *addnis = NULL;
2563         lnet_nid_t *delnis = NULL;
2564         unsigned flags;
2565         int ncurnis;
2566         int naddnis;
2567         int ndelnis;
2568         int nnis = 0;
2569         int i;
2570         int j;
2571         int rc;
2572
2573         flags = LNET_PEER_DISCOVERED;
2574         if (pbuf->pb_info.pi_features & LNET_PING_FEAT_MULTI_RAIL)
2575                 flags |= LNET_PEER_MULTI_RAIL;
2576
2577         /*
2578          * Cache the routing feature for the peer; whether it is enabled
2579          * for disabled as reported by the remote peer.
2580          */
2581         spin_lock(&lp->lp_lock);
2582         if (!(pbuf->pb_info.pi_features & LNET_PING_FEAT_RTE_DISABLED))
2583                 lp->lp_state |= LNET_PEER_ROUTER_ENABLED;
2584         else
2585                 lp->lp_state &= ~LNET_PEER_ROUTER_ENABLED;
2586         spin_unlock(&lp->lp_lock);
2587
2588         nnis = MAX(lp->lp_nnis, pbuf->pb_info.pi_nnis);
2589         LIBCFS_ALLOC(curnis, nnis * sizeof(*curnis));
2590         LIBCFS_ALLOC(addnis, nnis * sizeof(*addnis));
2591         LIBCFS_ALLOC(delnis, nnis * sizeof(*delnis));
2592         if (!curnis || !addnis || !delnis) {
2593                 rc = -ENOMEM;
2594                 goto out;
2595         }
2596         ncurnis = 0;
2597         naddnis = 0;
2598         ndelnis = 0;
2599
2600         /* Construct the list of NIDs present in peer. */
2601         lpni = NULL;
2602         while ((lpni = lnet_get_next_peer_ni_locked(lp, NULL, lpni)) != NULL)
2603                 curnis[ncurnis++] = lpni->lpni_nid;
2604
2605         /*
2606          * Check for NIDs in pbuf not present in curnis[].
2607          * The loop starts at 1 to skip the loopback NID.
2608          */
2609         for (i = 1; i < pbuf->pb_info.pi_nnis; i++) {
2610                 for (j = 0; j < ncurnis; j++)
2611                         if (pbuf->pb_info.pi_ni[i].ns_nid == curnis[j])
2612                                 break;
2613                 if (j == ncurnis)
2614                         addnis[naddnis++] = pbuf->pb_info.pi_ni[i];
2615         }
2616         /*
2617          * Check for NIDs in curnis[] not present in pbuf.
2618          * The nested loop starts at 1 to skip the loopback NID.
2619          *
2620          * But never add the loopback NID to delnis[]: if it is
2621          * present in curnis[] then this peer is for this node.
2622          */
2623         for (i = 0; i < ncurnis; i++) {
2624                 if (LNET_NETTYP(LNET_NIDNET(curnis[i])) == LOLND)
2625                         continue;
2626                 for (j = 1; j < pbuf->pb_info.pi_nnis; j++) {
2627                         if (curnis[i] == pbuf->pb_info.pi_ni[j].ns_nid) {
2628                                 /*
2629                                  * update the information we cache for the
2630                                  * peer with the latest information we
2631                                  * received
2632                                  */
2633                                 lpni = lnet_find_peer_ni_locked(curnis[i]);
2634                                 if (lpni) {
2635                                         lpni->lpni_ns_status = pbuf->pb_info.pi_ni[j].ns_status;
2636                                         lnet_peer_ni_decref_locked(lpni);
2637                                 }
2638                                 break;
2639                         }
2640                 }
2641                 if (j == pbuf->pb_info.pi_nnis)
2642                         delnis[ndelnis++] = curnis[i];
2643         }
2644
2645         /*
2646          * If we get here and the discovery is disabled then we don't want
2647          * to add or delete any NIs. We just updated the ones we have some
2648          * information on, and call it a day
2649          */
2650         rc = 0;
2651         if (lnet_is_discovery_disabled(lp))
2652                 goto out;
2653
2654         for (i = 0; i < naddnis; i++) {
2655                 rc = lnet_peer_add_nid(lp, addnis[i].ns_nid, flags);
2656                 if (rc) {
2657                         CERROR("Error adding NID %s to peer %s: %d\n",
2658                                libcfs_nid2str(addnis[i].ns_nid),
2659                                libcfs_nid2str(lp->lp_primary_nid), rc);
2660                         if (rc == -ENOMEM)
2661                                 goto out;
2662                 }
2663                 lpni = lnet_find_peer_ni_locked(addnis[i].ns_nid);
2664                 if (lpni) {
2665                         lpni->lpni_ns_status = addnis[i].ns_status;
2666                         lnet_peer_ni_decref_locked(lpni);
2667                 }
2668         }
2669
2670         for (i = 0; i < ndelnis; i++) {
2671                 /*
2672                  * for routers it's okay to delete the primary_nid because
2673                  * the upper layers don't really rely on it. So if we're
2674                  * being told that the router changed its primary_nid
2675                  * then it's okay to delete it.
2676                  */
2677                 if (lp->lp_rtr_refcount > 0)
2678                         flags |= LNET_PEER_RTR_NI_FORCE_DEL;
2679                 rc = lnet_peer_del_nid(lp, delnis[i], flags);
2680                 if (rc) {
2681                         CERROR("Error deleting NID %s from peer %s: %d\n",
2682                                libcfs_nid2str(delnis[i]),
2683                                libcfs_nid2str(lp->lp_primary_nid), rc);
2684                         if (rc == -ENOMEM)
2685                                 goto out;
2686                 }
2687         }
2688         /*
2689          * Errors other than -ENOMEM are due to peers having been
2690          * configured with DLC. Ignore these because DLC overrides
2691          * Discovery.
2692          */
2693         rc = 0;
2694 out:
2695         LIBCFS_FREE(curnis, nnis * sizeof(*curnis));
2696         LIBCFS_FREE(addnis, nnis * sizeof(*addnis));
2697         LIBCFS_FREE(delnis, nnis * sizeof(*delnis));
2698         lnet_ping_buffer_decref(pbuf);
2699         CDEBUG(D_NET, "peer %s (%p): %d\n", libcfs_nid2str(lp->lp_primary_nid), lp, rc);
2700
2701         if (rc) {
2702                 spin_lock(&lp->lp_lock);
2703                 lp->lp_state &= ~LNET_PEER_NIDS_UPTODATE;
2704                 lp->lp_state |= LNET_PEER_FORCE_PING;
2705                 spin_unlock(&lp->lp_lock);
2706         }
2707         return rc;
2708 }
2709
2710 /*
2711  * The data in pbuf says lp is its primary peer, but the data was
2712  * received by a different peer. Try to update lp with the data.
2713  */
2714 static int
2715 lnet_peer_set_primary_data(struct lnet_peer *lp, struct lnet_ping_buffer *pbuf)
2716 {
2717         struct lnet_handle_md mdh;
2718
2719         /* Queue lp for discovery, and force it on the request queue. */
2720         lnet_net_lock(LNET_LOCK_EX);
2721         if (lnet_peer_queue_for_discovery(lp))
2722                 list_move(&lp->lp_dc_list, &the_lnet.ln_dc_request);
2723         lnet_net_unlock(LNET_LOCK_EX);
2724
2725         LNetInvalidateMDHandle(&mdh);
2726
2727         /*
2728          * Decide whether we can move the peer to the DATA_PRESENT state.
2729          *
2730          * We replace stale data for a multi-rail peer, repair PING_FAILED
2731          * status, and preempt FORCE_PING.
2732          *
2733          * If after that we have DATA_PRESENT, we merge it into this peer.
2734          */
2735         spin_lock(&lp->lp_lock);
2736         if (lp->lp_state & LNET_PEER_MULTI_RAIL) {
2737                 if (lp->lp_peer_seqno < LNET_PING_BUFFER_SEQNO(pbuf)) {
2738                         lp->lp_peer_seqno = LNET_PING_BUFFER_SEQNO(pbuf);
2739                 } else if (lp->lp_state & LNET_PEER_DATA_PRESENT) {
2740                         lp->lp_state &= ~LNET_PEER_DATA_PRESENT;
2741                         lnet_ping_buffer_decref(pbuf);
2742                         pbuf = lp->lp_data;
2743                         lp->lp_data = NULL;
2744                 }
2745         }
2746         if (lp->lp_state & LNET_PEER_DATA_PRESENT) {
2747                 lnet_ping_buffer_decref(lp->lp_data);
2748                 lp->lp_data = NULL;
2749                 lp->lp_state &= ~LNET_PEER_DATA_PRESENT;
2750         }
2751         if (lp->lp_state & LNET_PEER_PING_FAILED) {
2752                 mdh = lp->lp_ping_mdh;
2753                 LNetInvalidateMDHandle(&lp->lp_ping_mdh);
2754                 lp->lp_state &= ~LNET_PEER_PING_FAILED;
2755                 lp->lp_ping_error = 0;
2756         }
2757         if (lp->lp_state & LNET_PEER_FORCE_PING)
2758                 lp->lp_state &= ~LNET_PEER_FORCE_PING;
2759         lp->lp_state |= LNET_PEER_NIDS_UPTODATE;
2760         spin_unlock(&lp->lp_lock);
2761
2762         if (!LNetMDHandleIsInvalid(mdh))
2763                 LNetMDUnlink(mdh);
2764
2765         if (pbuf)
2766                 return lnet_peer_merge_data(lp, pbuf);
2767
2768         CDEBUG(D_NET, "peer %s\n", libcfs_nid2str(lp->lp_primary_nid));
2769         return 0;
2770 }
2771
2772 static bool lnet_is_nid_in_ping_info(lnet_nid_t nid, struct lnet_ping_info *pinfo)
2773 {
2774         int i;
2775
2776         for (i = 0; i < pinfo->pi_nnis; i++) {
2777                 if (pinfo->pi_ni[i].ns_nid == nid)
2778                         return true;
2779         }
2780
2781         return false;
2782 }
2783
2784 /*
2785  * Update a peer using the data received.
2786  */
2787 static int lnet_peer_data_present(struct lnet_peer *lp)
2788 __must_hold(&lp->lp_lock)
2789 {
2790         struct lnet_ping_buffer *pbuf;
2791         struct lnet_peer_ni *lpni;
2792         lnet_nid_t nid = LNET_NID_ANY;
2793         unsigned flags;
2794         int rc = 0;
2795
2796         pbuf = lp->lp_data;
2797         lp->lp_data = NULL;
2798         lp->lp_state &= ~LNET_PEER_DATA_PRESENT;
2799         lp->lp_state |= LNET_PEER_NIDS_UPTODATE;
2800         spin_unlock(&lp->lp_lock);
2801
2802         /*
2803          * Modifications of peer structures are done while holding the
2804          * ln_api_mutex. A global lock is required because we may be
2805          * modifying multiple peer structures, and a mutex greatly
2806          * simplifies memory management.
2807          *
2808          * The actual changes to the data structures must also protect
2809          * against concurrent lookups, for which the lnet_net_lock in
2810          * LNET_LOCK_EX mode is used.
2811          */
2812         mutex_lock(&the_lnet.ln_api_mutex);
2813         if (the_lnet.ln_state != LNET_STATE_RUNNING) {
2814                 rc = -ESHUTDOWN;
2815                 goto out;
2816         }
2817
2818         /*
2819          * If this peer is not on the peer list then it is being torn
2820          * down, and our reference count may be all that is keeping it
2821          * alive. Don't do any work on it.
2822          */
2823         if (list_empty(&lp->lp_peer_list))
2824                 goto out;
2825
2826         flags = LNET_PEER_DISCOVERED;
2827         if (pbuf->pb_info.pi_features & LNET_PING_FEAT_MULTI_RAIL)
2828                 flags |= LNET_PEER_MULTI_RAIL;
2829
2830         /*
2831          * Check whether the primary NID in the message matches the
2832          * primary NID of the peer. If it does, update the peer, if
2833          * it it does not, check whether there is already a peer with
2834          * that primary NID. If no such peer exists, try to update
2835          * the primary NID of the current peer (allowed if it was
2836          * created due to message traffic) and complete the update.
2837          * If the peer did exist, hand off the data to it.
2838          *
2839          * The peer for the loopback interface is a special case: this
2840          * is the peer for the local node, and we want to set its
2841          * primary NID to the correct value here. Moreover, this peer
2842          * can show up with only the loopback NID in the ping buffer.
2843          */
2844         if (pbuf->pb_info.pi_nnis <= 1)
2845                 goto out;
2846         nid = pbuf->pb_info.pi_ni[1].ns_nid;
2847         if (LNET_NETTYP(LNET_NIDNET(lp->lp_primary_nid)) == LOLND) {
2848                 rc = lnet_peer_set_primary_nid(lp, nid, flags);
2849                 if (!rc)
2850                         rc = lnet_peer_merge_data(lp, pbuf);
2851         /*
2852          * if the primary nid of the peer is present in the ping info returned
2853          * from the peer, but it's not the local primary peer we have
2854          * cached and discovery is disabled, then we don't want to update
2855          * our local peer info, by adding or removing NIDs, we just want
2856          * to update the status of the nids that we currently have
2857          * recorded in that peer.
2858          */
2859         } else if (lp->lp_primary_nid == nid ||
2860                    (lnet_is_nid_in_ping_info(lp->lp_primary_nid, &pbuf->pb_info) &&
2861                     lnet_is_discovery_disabled(lp))) {
2862                 rc = lnet_peer_merge_data(lp, pbuf);
2863         } else {
2864                 lpni = lnet_find_peer_ni_locked(nid);
2865                 if (!lpni) {
2866                         rc = lnet_peer_set_primary_nid(lp, nid, flags);
2867                         if (rc) {
2868                                 CERROR("Primary NID error %s versus %s: %d\n",
2869                                        libcfs_nid2str(lp->lp_primary_nid),
2870                                        libcfs_nid2str(nid), rc);
2871                         } else {
2872                                 rc = lnet_peer_merge_data(lp, pbuf);
2873                         }
2874                 } else {
2875                         struct lnet_peer *new_lp;
2876                         new_lp = lpni->lpni_peer_net->lpn_peer;
2877                         /*
2878                          * if lp has discovery/MR enabled that means new_lp
2879                          * should have discovery/MR enabled as well, since
2880                          * it's the same peer, which we're about to merge
2881                          */
2882                         if (!(lp->lp_state & LNET_PEER_NO_DISCOVERY))
2883                                 new_lp->lp_state &= ~LNET_PEER_NO_DISCOVERY;
2884                         if (lp->lp_state & LNET_PEER_MULTI_RAIL)
2885                                 new_lp->lp_state |= LNET_PEER_MULTI_RAIL;
2886
2887                         rc = lnet_peer_set_primary_data(new_lp, pbuf);
2888                         lnet_consolidate_routes_locked(lp, new_lp);
2889                         lnet_peer_ni_decref_locked(lpni);
2890                 }
2891         }
2892 out:
2893         CDEBUG(D_NET, "peer %s(%p): %d. state = 0x%x\n", libcfs_nid2str(lp->lp_primary_nid), lp, rc,
2894                lp->lp_state);
2895         mutex_unlock(&the_lnet.ln_api_mutex);
2896
2897         spin_lock(&lp->lp_lock);
2898         /* Tell discovery to re-check the peer immediately. */
2899         if (!rc)
2900                 rc = LNET_REDISCOVER_PEER;
2901         return rc;
2902 }
2903
2904 /*
2905  * A ping failed. Clear the PING_FAILED state and set the
2906  * FORCE_PING state, to ensure a retry even if discovery is
2907  * disabled. This avoids being left with incorrect state.
2908  */
2909 static int lnet_peer_ping_failed(struct lnet_peer *lp)
2910 __must_hold(&lp->lp_lock)
2911 {
2912         struct lnet_handle_md mdh;
2913         int rc;
2914
2915         mdh = lp->lp_ping_mdh;
2916         LNetInvalidateMDHandle(&lp->lp_ping_mdh);
2917         lp->lp_state &= ~LNET_PEER_PING_FAILED;
2918         lp->lp_state |= LNET_PEER_FORCE_PING;
2919         rc = lp->lp_ping_error;
2920         lp->lp_ping_error = 0;
2921         spin_unlock(&lp->lp_lock);
2922
2923         if (!LNetMDHandleIsInvalid(mdh))
2924                 LNetMDUnlink(mdh);
2925
2926         CDEBUG(D_NET, "peer %s:%d\n",
2927                libcfs_nid2str(lp->lp_primary_nid), rc);
2928
2929         spin_lock(&lp->lp_lock);
2930         return rc ? rc : LNET_REDISCOVER_PEER;
2931 }
2932
2933 /*
2934  * Select NID to send a Ping or Push to.
2935  */
2936 static lnet_nid_t lnet_peer_select_nid(struct lnet_peer *lp)
2937 {
2938         struct lnet_peer_ni *lpni;
2939
2940         /* Look for a direct-connected NID for this peer. */
2941         lpni = NULL;
2942         while ((lpni = lnet_get_next_peer_ni_locked(lp, NULL, lpni)) != NULL) {
2943                 if (!lnet_get_net_locked(lpni->lpni_peer_net->lpn_net_id))
2944                         continue;
2945                 break;
2946         }
2947         if (lpni)
2948                 return lpni->lpni_nid;
2949
2950         /* Look for a routed-connected NID for this peer. */
2951         lpni = NULL;
2952         while ((lpni = lnet_get_next_peer_ni_locked(lp, NULL, lpni)) != NULL) {
2953                 if (!lnet_find_rnet_locked(lpni->lpni_peer_net->lpn_net_id))
2954                         continue;
2955                 break;
2956         }
2957         if (lpni)
2958                 return lpni->lpni_nid;
2959
2960         return LNET_NID_ANY;
2961 }
2962
2963 /* Active side of ping. */
2964 static int lnet_peer_send_ping(struct lnet_peer *lp)
2965 __must_hold(&lp->lp_lock)
2966 {
2967         lnet_nid_t pnid;
2968         int nnis;
2969         int rc;
2970         int cpt;
2971
2972         lp->lp_state |= LNET_PEER_PING_SENT;
2973         lp->lp_state &= ~LNET_PEER_FORCE_PING;
2974         spin_unlock(&lp->lp_lock);
2975
2976         cpt = lnet_net_lock_current();
2977         /* Refcount for MD. */
2978         lnet_peer_addref_locked(lp);
2979         pnid = lnet_peer_select_nid(lp);
2980         lnet_net_unlock(cpt);
2981
2982         nnis = MAX(lp->lp_data_nnis, LNET_INTERFACES_MIN);
2983
2984         rc = lnet_send_ping(pnid, &lp->lp_ping_mdh, nnis, lp,
2985                             the_lnet.ln_dc_eqh, false);
2986
2987         /*
2988          * if LNetMDBind in lnet_send_ping fails we need to decrement the
2989          * refcount on the peer, otherwise LNetMDUnlink will be called
2990          * which will eventually do that.
2991          */
2992         if (rc > 0) {
2993                 lnet_net_lock(cpt);
2994                 lnet_peer_decref_locked(lp);
2995                 lnet_net_unlock(cpt);
2996                 rc = -rc; /* change the rc to negative value */
2997                 goto fail_error;
2998         } else if (rc < 0) {
2999                 goto fail_error;
3000         }
3001
3002         CDEBUG(D_NET, "peer %s\n", libcfs_nid2str(lp->lp_primary_nid));
3003
3004         spin_lock(&lp->lp_lock);
3005         return 0;
3006
3007 fail_error:
3008         CDEBUG(D_NET, "peer %s: %d\n", libcfs_nid2str(lp->lp_primary_nid), rc);
3009         /*
3010          * The errors that get us here are considered hard errors and
3011          * cause Discovery to terminate. So we clear PING_SENT, but do
3012          * not set either PING_FAILED or FORCE_PING. In fact we need
3013          * to clear PING_FAILED, because the unlink event handler will
3014          * have set it if we called LNetMDUnlink() above.
3015          */
3016         spin_lock(&lp->lp_lock);
3017         lp->lp_state &= ~(LNET_PEER_PING_SENT | LNET_PEER_PING_FAILED);
3018         return rc;
3019 }
3020
3021 /*
3022  * This function exists because you cannot call LNetMDUnlink() from an
3023  * event handler.
3024  */
3025 static int lnet_peer_push_failed(struct lnet_peer *lp)
3026 __must_hold(&lp->lp_lock)
3027 {
3028         struct lnet_handle_md mdh;
3029         int rc;
3030
3031         mdh = lp->lp_push_mdh;
3032         LNetInvalidateMDHandle(&lp->lp_push_mdh);
3033         lp->lp_state &= ~LNET_PEER_PUSH_FAILED;
3034         rc = lp->lp_push_error;
3035         lp->lp_push_error = 0;
3036         spin_unlock(&lp->lp_lock);
3037
3038         if (!LNetMDHandleIsInvalid(mdh))
3039                 LNetMDUnlink(mdh);
3040
3041         CDEBUG(D_NET, "peer %s\n", libcfs_nid2str(lp->lp_primary_nid));
3042         spin_lock(&lp->lp_lock);
3043         return rc ? rc : LNET_REDISCOVER_PEER;
3044 }
3045
3046 /* Active side of push. */
3047 static int lnet_peer_send_push(struct lnet_peer *lp)
3048 __must_hold(&lp->lp_lock)
3049 {
3050         struct lnet_ping_buffer *pbuf;
3051         struct lnet_process_id id;
3052         struct lnet_md md;
3053         int cpt;
3054         int rc;
3055
3056         /* Don't push to a non-multi-rail peer. */
3057         if (!(lp->lp_state & LNET_PEER_MULTI_RAIL)) {
3058                 lp->lp_state &= ~LNET_PEER_FORCE_PUSH;
3059                 return 0;
3060         }
3061
3062         lp->lp_state |= LNET_PEER_PUSH_SENT;
3063         lp->lp_state &= ~LNET_PEER_FORCE_PUSH;
3064         spin_unlock(&lp->lp_lock);
3065
3066         cpt = lnet_net_lock_current();
3067         pbuf = the_lnet.ln_ping_target;
3068         lnet_ping_buffer_addref(pbuf);
3069         lnet_net_unlock(cpt);
3070
3071         /* Push source MD */
3072         md.start     = &pbuf->pb_info;
3073         md.length    = LNET_PING_INFO_SIZE(pbuf->pb_nnis);
3074         md.threshold = 2; /* Put/Ack */
3075         md.max_size  = 0;
3076         md.options   = 0;
3077         md.eq_handle = the_lnet.ln_dc_eqh;
3078         md.user_ptr  = lp;
3079
3080         rc = LNetMDBind(md, LNET_UNLINK, &lp->lp_push_mdh);
3081         if (rc) {
3082                 lnet_ping_buffer_decref(pbuf);
3083                 CERROR("Can't bind push source MD: %d\n", rc);
3084                 goto fail_error;
3085         }
3086         cpt = lnet_net_lock_current();
3087         /* Refcount for MD. */
3088         lnet_peer_addref_locked(lp);
3089         id.pid = LNET_PID_LUSTRE;
3090         id.nid = lnet_peer_select_nid(lp);
3091         lnet_net_unlock(cpt);
3092
3093         if (id.nid == LNET_NID_ANY) {
3094                 rc = -EHOSTUNREACH;
3095                 goto fail_unlink;
3096         }
3097
3098         rc = LNetPut(LNET_NID_ANY, lp->lp_push_mdh,
3099                      LNET_ACK_REQ, id, LNET_RESERVED_PORTAL,
3100                      LNET_PROTO_PING_MATCHBITS, 0, 0);
3101
3102         if (rc)
3103                 goto fail_unlink;
3104
3105         CDEBUG(D_NET, "peer %s\n", libcfs_nid2str(lp->lp_primary_nid));
3106
3107         spin_lock(&lp->lp_lock);
3108         return 0;
3109
3110 fail_unlink:
3111         LNetMDUnlink(lp->lp_push_mdh);
3112         LNetInvalidateMDHandle(&lp->lp_push_mdh);
3113 fail_error:
3114         CDEBUG(D_NET, "peer %s(%p): %d\n", libcfs_nid2str(lp->lp_primary_nid), lp, rc);
3115         /*
3116          * The errors that get us here are considered hard errors and
3117          * cause Discovery to terminate. So we clear PUSH_SENT, but do
3118          * not set PUSH_FAILED. In fact we need to clear PUSH_FAILED,
3119          * because the unlink event handler will have set it if we
3120          * called LNetMDUnlink() above.
3121          */
3122         spin_lock(&lp->lp_lock);
3123         lp->lp_state &= ~(LNET_PEER_PUSH_SENT | LNET_PEER_PUSH_FAILED);
3124         return rc;
3125 }
3126
3127 /*
3128  * An unrecoverable error was encountered during discovery.
3129  * Set error status in peer and abort discovery.
3130  */
3131 static void lnet_peer_discovery_error(struct lnet_peer *lp, int error)
3132 {
3133         CDEBUG(D_NET, "Discovery error %s: %d\n",
3134                libcfs_nid2str(lp->lp_primary_nid), error);
3135
3136         spin_lock(&lp->lp_lock);
3137         lp->lp_dc_error = error;
3138         lp->lp_state &= ~LNET_PEER_DISCOVERING;
3139         lp->lp_state |= LNET_PEER_REDISCOVER;
3140         spin_unlock(&lp->lp_lock);
3141 }
3142
3143 /*
3144  * Mark the peer as discovered.
3145  */
3146 static int lnet_peer_discovered(struct lnet_peer *lp)
3147 __must_hold(&lp->lp_lock)
3148 {
3149         lp->lp_state |= LNET_PEER_DISCOVERED;
3150         lp->lp_state &= ~(LNET_PEER_DISCOVERING |
3151                           LNET_PEER_REDISCOVER);
3152
3153         CDEBUG(D_NET, "peer %s\n", libcfs_nid2str(lp->lp_primary_nid));
3154
3155         return 0;
3156 }
3157
3158
3159 /*
3160  * Discovering this peer is taking too long. Cancel any Ping or Push
3161  * that discovery is waiting on by unlinking the relevant MDs. The
3162  * lnet_discovery_event_handler() will proceed from here and complete
3163  * the cleanup.
3164  */
3165 static void lnet_peer_cancel_discovery(struct lnet_peer *lp)
3166 {
3167         struct lnet_handle_md ping_mdh;
3168         struct lnet_handle_md push_mdh;
3169
3170         LNetInvalidateMDHandle(&ping_mdh);
3171         LNetInvalidateMDHandle(&push_mdh);
3172
3173         spin_lock(&lp->lp_lock);
3174         if (lp->lp_state & LNET_PEER_PING_SENT) {
3175                 ping_mdh = lp->lp_ping_mdh;
3176                 LNetInvalidateMDHandle(&lp->lp_ping_mdh);
3177         }
3178         if (lp->lp_state & LNET_PEER_PUSH_SENT) {
3179                 push_mdh = lp->lp_push_mdh;
3180                 LNetInvalidateMDHandle(&lp->lp_push_mdh);
3181         }
3182         spin_unlock(&lp->lp_lock);
3183
3184         if (!LNetMDHandleIsInvalid(ping_mdh))
3185                 LNetMDUnlink(ping_mdh);
3186         if (!LNetMDHandleIsInvalid(push_mdh))
3187                 LNetMDUnlink(push_mdh);
3188 }
3189
3190 /*
3191  * Wait for work to be queued or some other change that must be
3192  * attended to. Returns non-zero if the discovery thread should shut
3193  * down.
3194  */
3195 static int lnet_peer_discovery_wait_for_work(void)
3196 {
3197         int cpt;
3198         int rc = 0;
3199
3200         DEFINE_WAIT(wait);
3201
3202         cpt = lnet_net_lock_current();
3203         for (;;) {
3204                 prepare_to_wait(&the_lnet.ln_dc_waitq, &wait,
3205                                 TASK_INTERRUPTIBLE);
3206                 if (the_lnet.ln_dc_state == LNET_DC_STATE_STOPPING)
3207                         break;
3208                 if (lnet_push_target_resize_needed())
3209                         break;
3210                 if (!list_empty(&the_lnet.ln_dc_request))
3211                         break;
3212                 if (!list_empty(&the_lnet.ln_msg_resend))
3213                         break;
3214                 lnet_net_unlock(cpt);
3215
3216                 /*
3217                  * wakeup max every second to check if there are peers that
3218                  * have been stuck on the working queue for greater than
3219                  * the peer timeout.
3220                  */
3221                 schedule_timeout(cfs_time_seconds(1));
3222                 finish_wait(&the_lnet.ln_dc_waitq, &wait);
3223                 cpt = lnet_net_lock_current();
3224         }
3225         finish_wait(&the_lnet.ln_dc_waitq, &wait);
3226
3227         if (the_lnet.ln_dc_state == LNET_DC_STATE_STOPPING)
3228                 rc = -ESHUTDOWN;
3229
3230         lnet_net_unlock(cpt);
3231
3232         CDEBUG(D_NET, "woken: %d\n", rc);
3233
3234         return rc;
3235 }
3236
3237 /*
3238  * Messages that were pending on a destroyed peer will be put on a global
3239  * resend list. The message resend list will be checked by
3240  * the discovery thread when it wakes up, and will resend messages. These
3241  * messages can still be sendable in the case the lpni which was the initial
3242  * cause of the message re-queue was transfered to another peer.
3243  *
3244  * It is possible that LNet could be shutdown while we're iterating
3245  * through the list. lnet_shudown_lndnets() will attempt to access the
3246  * resend list, but will have to wait until the spinlock is released, by
3247  * which time there shouldn't be any more messages on the resend list.
3248  * During shutdown lnet_send() will fail and lnet_finalize() will be called
3249  * for the messages so they can be released. The other case is that
3250  * lnet_shudown_lndnets() can finalize all the messages before this
3251  * function can visit the resend list, in which case this function will be
3252  * a no-op.
3253  */
3254 static void lnet_resend_msgs(void)
3255 {
3256         struct lnet_msg *msg, *tmp;
3257         struct list_head resend;
3258         int rc;
3259
3260         INIT_LIST_HEAD(&resend);
3261
3262         spin_lock(&the_lnet.ln_msg_resend_lock);
3263         list_splice(&the_lnet.ln_msg_resend, &resend);
3264         spin_unlock(&the_lnet.ln_msg_resend_lock);
3265
3266         list_for_each_entry_safe(msg, tmp, &resend, msg_list) {
3267                 list_del_init(&msg->msg_list);
3268                 rc = lnet_send(msg->msg_src_nid_param, msg,
3269                                msg->msg_rtr_nid_param);
3270                 if (rc < 0) {
3271                         CNETERR("Error sending %s to %s: %d\n",
3272                                lnet_msgtyp2str(msg->msg_type),
3273                                libcfs_id2str(msg->msg_target), rc);
3274                         lnet_finalize(msg, rc);
3275                 }
3276         }
3277 }
3278
3279 /* The discovery thread. */
3280 static int lnet_peer_discovery(void *arg)
3281 {
3282         struct lnet_peer *lp;
3283         int rc;
3284
3285         wait_for_completion(&the_lnet.ln_started);
3286
3287         CDEBUG(D_NET, "started\n");
3288         cfs_block_allsigs();
3289
3290         for (;;) {
3291                 if (lnet_peer_discovery_wait_for_work())
3292                         break;
3293
3294                 lnet_resend_msgs();
3295
3296                 if (lnet_push_target_resize_needed())
3297                         lnet_push_target_resize();
3298
3299                 lnet_net_lock(LNET_LOCK_EX);
3300                 if (the_lnet.ln_dc_state == LNET_DC_STATE_STOPPING)
3301                         break;
3302
3303                 /*
3304                  * Process all incoming discovery work requests.  When
3305                  * discovery must wait on a peer to change state, it
3306                  * is added to the tail of the ln_dc_working queue. A
3307                  * timestamp keeps track of when the peer was added,
3308                  * so we can time out discovery requests that take too
3309                  * long.
3310                  */
3311                 while (!list_empty(&the_lnet.ln_dc_request)) {
3312                         lp = list_first_entry(&the_lnet.ln_dc_request,
3313                                               struct lnet_peer, lp_dc_list);
3314                         list_move(&lp->lp_dc_list, &the_lnet.ln_dc_working);
3315                         /*
3316                          * set the time the peer was put on the dc_working
3317                          * queue. It shouldn't remain on the queue
3318                          * forever, in case the GET message (for ping)
3319                          * doesn't get a REPLY or the PUT message (for
3320                          * push) doesn't get an ACK.
3321                          */
3322                         lp->lp_last_queued = ktime_get_real_seconds();
3323                         lnet_net_unlock(LNET_LOCK_EX);
3324
3325                         /*
3326                          * Select an action depending on the state of
3327                          * the peer and whether discovery is disabled.
3328                          * The check whether discovery is disabled is
3329                          * done after the code that handles processing
3330                          * for arrived data, cleanup for failures, and
3331                          * forcing a Ping or Push.
3332                          */
3333                         spin_lock(&lp->lp_lock);
3334                         CDEBUG(D_NET, "peer %s(%p) state %#x\n",
3335                                 libcfs_nid2str(lp->lp_primary_nid), lp,
3336                                 lp->lp_state);
3337                         if (lp->lp_state & LNET_PEER_DATA_PRESENT)
3338                                 rc = lnet_peer_data_present(lp);
3339                         else if (lp->lp_state & LNET_PEER_PING_FAILED)
3340                                 rc = lnet_peer_ping_failed(lp);
3341                         else if (lp->lp_state & LNET_PEER_PUSH_FAILED)
3342                                 rc = lnet_peer_push_failed(lp);
3343                         else if (lp->lp_state & LNET_PEER_FORCE_PING)
3344                                 rc = lnet_peer_send_ping(lp);
3345                         else if (lp->lp_state & LNET_PEER_FORCE_PUSH)
3346                                 rc = lnet_peer_send_push(lp);
3347                         else if (!(lp->lp_state & LNET_PEER_NIDS_UPTODATE))
3348                                 rc = lnet_peer_send_ping(lp);
3349                         else if (lnet_peer_needs_push(lp))
3350                                 rc = lnet_peer_send_push(lp);
3351                         else
3352                                 rc = lnet_peer_discovered(lp);
3353                         CDEBUG(D_NET, "peer %s(%p) state %#x rc %d\n",
3354                                 libcfs_nid2str(lp->lp_primary_nid), lp,
3355                                 lp->lp_state, rc);
3356                         spin_unlock(&lp->lp_lock);
3357
3358                         lnet_net_lock(LNET_LOCK_EX);
3359                         if (rc == LNET_REDISCOVER_PEER) {
3360                                 list_move(&lp->lp_dc_list,
3361                                           &the_lnet.ln_dc_request);
3362                         } else if (rc) {
3363                                 lnet_peer_discovery_error(lp, rc);
3364                         }
3365                         if (!(lp->lp_state & LNET_PEER_DISCOVERING))
3366                                 lnet_peer_discovery_complete(lp);
3367                         if (the_lnet.ln_dc_state == LNET_DC_STATE_STOPPING)
3368                                 break;
3369                 }
3370
3371                 lnet_net_unlock(LNET_LOCK_EX);
3372         }
3373
3374         CDEBUG(D_NET, "stopping\n");
3375         /*
3376          * Clean up before telling lnet_peer_discovery_stop() that
3377          * we're done. Use wake_up() below to somewhat reduce the
3378          * size of the thundering herd if there are multiple threads
3379          * waiting on discovery of a single peer.
3380          */
3381
3382         /* Queue cleanup 1: stop all pending pings and pushes. */
3383         lnet_net_lock(LNET_LOCK_EX);
3384         while (!list_empty(&the_lnet.ln_dc_working)) {
3385                 lp = list_first_entry(&the_lnet.ln_dc_working,
3386                                       struct lnet_peer, lp_dc_list);
3387                 list_move(&lp->lp_dc_list, &the_lnet.ln_dc_expired);
3388                 lnet_net_unlock(LNET_LOCK_EX);
3389                 lnet_peer_cancel_discovery(lp);
3390                 lnet_net_lock(LNET_LOCK_EX);
3391         }
3392         lnet_net_unlock(LNET_LOCK_EX);
3393
3394         /* Queue cleanup 2: wait for the expired queue to clear. */
3395         while (!list_empty(&the_lnet.ln_dc_expired))
3396                 schedule_timeout(cfs_time_seconds(1));
3397
3398         /* Queue cleanup 3: clear the request queue. */
3399         lnet_net_lock(LNET_LOCK_EX);
3400         while (!list_empty(&the_lnet.ln_dc_request)) {
3401                 lp = list_first_entry(&the_lnet.ln_dc_request,
3402                                       struct lnet_peer, lp_dc_list);
3403                 lnet_peer_discovery_error(lp, -ESHUTDOWN);
3404                 lnet_peer_discovery_complete(lp);
3405         }
3406         lnet_net_unlock(LNET_LOCK_EX);
3407
3408         LNetEQFree(the_lnet.ln_dc_eqh);
3409         LNetInvalidateEQHandle(&the_lnet.ln_dc_eqh);
3410
3411         the_lnet.ln_dc_state = LNET_DC_STATE_SHUTDOWN;
3412         wake_up(&the_lnet.ln_dc_waitq);
3413
3414         CDEBUG(D_NET, "stopped\n");
3415
3416         return 0;
3417 }
3418
3419 /* ln_api_mutex is held on entry. */
3420 int lnet_peer_discovery_start(void)
3421 {
3422         struct task_struct *task;
3423         int rc;
3424
3425         if (the_lnet.ln_dc_state != LNET_DC_STATE_SHUTDOWN)
3426                 return -EALREADY;
3427
3428         rc = LNetEQAlloc(0, lnet_discovery_event_handler, &the_lnet.ln_dc_eqh);
3429         if (rc != 0) {
3430                 CERROR("Can't allocate discovery EQ: %d\n", rc);
3431                 return rc;
3432         }
3433
3434         the_lnet.ln_dc_state = LNET_DC_STATE_RUNNING;
3435         task = kthread_run(lnet_peer_discovery, NULL, "lnet_discovery");
3436         if (IS_ERR(task)) {
3437                 rc = PTR_ERR(task);
3438                 CERROR("Can't start peer discovery thread: %d\n", rc);
3439
3440                 LNetEQFree(the_lnet.ln_dc_eqh);
3441                 LNetInvalidateEQHandle(&the_lnet.ln_dc_eqh);
3442
3443                 the_lnet.ln_dc_state = LNET_DC_STATE_SHUTDOWN;
3444         }
3445
3446         CDEBUG(D_NET, "discovery start: %d\n", rc);
3447
3448         return rc;
3449 }
3450
3451 /* ln_api_mutex is held on entry. */
3452 void lnet_peer_discovery_stop(void)
3453 {
3454         if (the_lnet.ln_dc_state == LNET_DC_STATE_SHUTDOWN)
3455                 return;
3456
3457         LASSERT(the_lnet.ln_dc_state == LNET_DC_STATE_RUNNING);
3458         the_lnet.ln_dc_state = LNET_DC_STATE_STOPPING;
3459
3460         /* In the LNetNIInit() path we may be stopping discovery before it
3461          * entered its work loop
3462          */
3463         if (!completion_done(&the_lnet.ln_started))
3464                 complete(&the_lnet.ln_started);
3465         else
3466                 wake_up(&the_lnet.ln_dc_waitq);
3467
3468         wait_event(the_lnet.ln_dc_waitq,
3469                    the_lnet.ln_dc_state == LNET_DC_STATE_SHUTDOWN);
3470
3471         LASSERT(list_empty(&the_lnet.ln_dc_request));
3472         LASSERT(list_empty(&the_lnet.ln_dc_working));
3473         LASSERT(list_empty(&the_lnet.ln_dc_expired));
3474
3475         CDEBUG(D_NET, "discovery stopped\n");
3476 }
3477
3478 /* Debugging */
3479
3480 void
3481 lnet_debug_peer(lnet_nid_t nid)
3482 {
3483         char                    *aliveness = "NA";
3484         struct lnet_peer_ni     *lp;
3485         int                     cpt;
3486
3487         cpt = lnet_cpt_of_nid(nid, NULL);
3488         lnet_net_lock(cpt);
3489
3490         lp = lnet_nid2peerni_locked(nid, LNET_NID_ANY, cpt);
3491         if (IS_ERR(lp)) {
3492                 lnet_net_unlock(cpt);
3493                 CDEBUG(D_WARNING, "No peer %s\n", libcfs_nid2str(nid));
3494                 return;
3495         }
3496
3497         if (lnet_isrouter(lp) || lnet_peer_aliveness_enabled(lp))
3498                 aliveness = (lnet_is_peer_ni_alive(lp)) ? "up" : "down";
3499
3500         CDEBUG(D_WARNING, "%-24s %4d %5s %5d %5d %5d %5d %5d %ld\n",
3501                libcfs_nid2str(lp->lpni_nid), atomic_read(&lp->lpni_refcount),
3502                aliveness, lp->lpni_net->net_tunables.lct_peer_tx_credits,
3503                lp->lpni_rtrcredits, lp->lpni_minrtrcredits,
3504                lp->lpni_txcredits, lp->lpni_mintxcredits, lp->lpni_txqnob);
3505
3506         lnet_peer_ni_decref_locked(lp);
3507
3508         lnet_net_unlock(cpt);
3509 }
3510
3511 /* Gathering information for userspace. */
3512
3513 int lnet_get_peer_ni_info(__u32 peer_index, __u64 *nid,
3514                           char aliveness[LNET_MAX_STR_LEN],
3515                           __u32 *cpt_iter, __u32 *refcount,
3516                           __u32 *ni_peer_tx_credits, __u32 *peer_tx_credits,
3517                           __u32 *peer_rtr_credits, __u32 *peer_min_rtr_credits,
3518                           __u32 *peer_tx_qnob)
3519 {
3520         struct lnet_peer_table          *peer_table;
3521         struct lnet_peer_ni             *lp;
3522         int                             j;
3523         int                             lncpt;
3524         bool                            found = false;
3525
3526         /* get the number of CPTs */
3527         lncpt = cfs_percpt_number(the_lnet.ln_peer_tables);
3528
3529         /* if the cpt number to be examined is >= the number of cpts in
3530          * the system then indicate that there are no more cpts to examin
3531          */
3532         if (*cpt_iter >= lncpt)
3533                 return -ENOENT;
3534
3535         /* get the current table */
3536         peer_table = the_lnet.ln_peer_tables[*cpt_iter];
3537         /* if the ptable is NULL then there are no more cpts to examine */
3538         if (peer_table == NULL)
3539                 return -ENOENT;
3540
3541         lnet_net_lock(*cpt_iter);
3542
3543         for (j = 0; j < LNET_PEER_HASH_SIZE && !found; j++) {
3544                 struct list_head *peers = &peer_table->pt_hash[j];
3545
3546                 list_for_each_entry(lp, peers, lpni_hashlist) {
3547                         if (peer_index-- > 0)
3548                                 continue;
3549
3550                         snprintf(aliveness, LNET_MAX_STR_LEN, "NA");
3551                         if (lnet_isrouter(lp) ||
3552                                 lnet_peer_aliveness_enabled(lp))
3553                                 snprintf(aliveness, LNET_MAX_STR_LEN,
3554                                          lnet_is_peer_ni_alive(lp) ? "up" : "down");
3555
3556                         *nid = lp->lpni_nid;
3557                         *refcount = atomic_read(&lp->lpni_refcount);
3558                         *ni_peer_tx_credits =
3559                                 lp->lpni_net->net_tunables.lct_peer_tx_credits;
3560                         *peer_tx_credits = lp->lpni_txcredits;
3561                         *peer_rtr_credits = lp->lpni_rtrcredits;
3562                         *peer_min_rtr_credits = lp->lpni_mintxcredits;
3563                         *peer_tx_qnob = lp->lpni_txqnob;
3564
3565                         found = true;
3566                 }
3567
3568         }
3569         lnet_net_unlock(*cpt_iter);
3570
3571         *cpt_iter = lncpt;
3572
3573         return found ? 0 : -ENOENT;
3574 }
3575
3576 /* ln_api_mutex is held, which keeps the peer list stable */
3577 int lnet_get_peer_info(struct lnet_ioctl_peer_cfg *cfg, void __user *bulk)
3578 {
3579         struct lnet_ioctl_element_stats *lpni_stats;
3580         struct lnet_ioctl_element_msg_stats *lpni_msg_stats;
3581         struct lnet_ioctl_peer_ni_hstats *lpni_hstats;
3582         struct lnet_peer_ni_credit_info *lpni_info;
3583         struct lnet_peer_ni *lpni;
3584         struct lnet_peer *lp;
3585         lnet_nid_t nid;
3586         __u32 size;
3587         int rc;
3588
3589         lp = lnet_find_peer(cfg->prcfg_prim_nid);
3590
3591         if (!lp) {
3592                 rc = -ENOENT;
3593                 goto out;
3594         }
3595
3596         size = sizeof(nid) + sizeof(*lpni_info) + sizeof(*lpni_stats)
3597                 + sizeof(*lpni_msg_stats) + sizeof(*lpni_hstats);
3598         size *= lp->lp_nnis;
3599         if (size > cfg->prcfg_size) {
3600                 cfg->prcfg_size = size;
3601                 rc = -E2BIG;
3602                 goto out_lp_decref;
3603         }
3604
3605         cfg->prcfg_prim_nid = lp->lp_primary_nid;
3606         cfg->prcfg_mr = lnet_peer_is_multi_rail(lp);
3607         cfg->prcfg_cfg_nid = lp->lp_primary_nid;
3608         cfg->prcfg_count = lp->lp_nnis;
3609         cfg->prcfg_size = size;
3610         cfg->prcfg_state = lp->lp_state;
3611
3612         /* Allocate helper buffers. */
3613         rc = -ENOMEM;
3614         LIBCFS_ALLOC(lpni_info, sizeof(*lpni_info));
3615         if (!lpni_info)
3616                 goto out_lp_decref;
3617         LIBCFS_ALLOC(lpni_stats, sizeof(*lpni_stats));
3618         if (!lpni_stats)
3619                 goto out_free_info;
3620         LIBCFS_ALLOC(lpni_msg_stats, sizeof(*lpni_msg_stats));
3621         if (!lpni_msg_stats)
3622                 goto out_free_stats;
3623         LIBCFS_ALLOC(lpni_hstats, sizeof(*lpni_hstats));
3624         if (!lpni_hstats)
3625                 goto out_free_msg_stats;
3626
3627
3628         lpni = NULL;
3629         rc = -EFAULT;
3630         while ((lpni = lnet_get_next_peer_ni_locked(lp, NULL, lpni)) != NULL) {
3631                 nid = lpni->lpni_nid;
3632                 if (copy_to_user(bulk, &nid, sizeof(nid)))
3633                         goto out_free_hstats;
3634                 bulk += sizeof(nid);
3635
3636                 memset(lpni_info, 0, sizeof(*lpni_info));
3637                 snprintf(lpni_info->cr_aliveness, LNET_MAX_STR_LEN, "NA");
3638                 if (lnet_isrouter(lpni) ||
3639                         lnet_peer_aliveness_enabled(lpni))
3640                         snprintf(lpni_info->cr_aliveness, LNET_MAX_STR_LEN,
3641                                 lnet_is_peer_ni_alive(lpni) ? "up" : "down");
3642
3643                 lpni_info->cr_refcount = atomic_read(&lpni->lpni_refcount);
3644                 lpni_info->cr_ni_peer_tx_credits = (lpni->lpni_net != NULL) ?
3645                         lpni->lpni_net->net_tunables.lct_peer_tx_credits : 0;
3646                 lpni_info->cr_peer_tx_credits = lpni->lpni_txcredits;
3647                 lpni_info->cr_peer_rtr_credits = lpni->lpni_rtrcredits;
3648                 lpni_info->cr_peer_min_rtr_credits = lpni->lpni_minrtrcredits;
3649                 lpni_info->cr_peer_min_tx_credits = lpni->lpni_mintxcredits;
3650                 lpni_info->cr_peer_tx_qnob = lpni->lpni_txqnob;
3651                 if (copy_to_user(bulk, lpni_info, sizeof(*lpni_info)))
3652                         goto out_free_hstats;
3653                 bulk += sizeof(*lpni_info);
3654
3655                 memset(lpni_stats, 0, sizeof(*lpni_stats));
3656                 lpni_stats->iel_send_count = lnet_sum_stats(&lpni->lpni_stats,
3657                                                             LNET_STATS_TYPE_SEND);
3658                 lpni_stats->iel_recv_count = lnet_sum_stats(&lpni->lpni_stats,
3659                                                             LNET_STATS_TYPE_RECV);
3660                 lpni_stats->iel_drop_count = lnet_sum_stats(&lpni->lpni_stats,
3661                                                             LNET_STATS_TYPE_DROP);
3662                 if (copy_to_user(bulk, lpni_stats, sizeof(*lpni_stats)))
3663                         goto out_free_hstats;
3664                 bulk += sizeof(*lpni_stats);
3665                 lnet_usr_translate_stats(lpni_msg_stats, &lpni->lpni_stats);
3666                 if (copy_to_user(bulk, lpni_msg_stats, sizeof(*lpni_msg_stats)))
3667                         goto out_free_hstats;
3668                 bulk += sizeof(*lpni_msg_stats);
3669                 lpni_hstats->hlpni_network_timeout =
3670                   atomic_read(&lpni->lpni_hstats.hlt_network_timeout);
3671                 lpni_hstats->hlpni_remote_dropped =
3672                   atomic_read(&lpni->lpni_hstats.hlt_remote_dropped);
3673                 lpni_hstats->hlpni_remote_timeout =
3674                   atomic_read(&lpni->lpni_hstats.hlt_remote_timeout);
3675                 lpni_hstats->hlpni_remote_error =
3676                   atomic_read(&lpni->lpni_hstats.hlt_remote_error);
3677                 lpni_hstats->hlpni_health_value =
3678                   atomic_read(&lpni->lpni_healthv);
3679                 if (copy_to_user(bulk, lpni_hstats, sizeof(*lpni_hstats)))
3680                         goto out_free_hstats;
3681                 bulk += sizeof(*lpni_hstats);
3682         }
3683         rc = 0;
3684
3685 out_free_hstats:
3686         LIBCFS_FREE(lpni_hstats, sizeof(*lpni_hstats));
3687 out_free_msg_stats:
3688         LIBCFS_FREE(lpni_msg_stats, sizeof(*lpni_msg_stats));
3689 out_free_stats:
3690         LIBCFS_FREE(lpni_stats, sizeof(*lpni_stats));
3691 out_free_info:
3692         LIBCFS_FREE(lpni_info, sizeof(*lpni_info));
3693 out_lp_decref:
3694         lnet_peer_decref_locked(lp);
3695 out:
3696         return rc;
3697 }
3698
3699 void
3700 lnet_peer_ni_add_to_recoveryq_locked(struct lnet_peer_ni *lpni)
3701 {
3702         /* the mt could've shutdown and cleaned up the queues */
3703         if (the_lnet.ln_mt_state != LNET_MT_STATE_RUNNING)
3704                 return;
3705
3706         if (list_empty(&lpni->lpni_recovery) &&
3707             atomic_read(&lpni->lpni_healthv) < LNET_MAX_HEALTH_VALUE) {
3708                 CERROR("lpni %s added to recovery queue. Health = %d\n",
3709                         libcfs_nid2str(lpni->lpni_nid),
3710                         atomic_read(&lpni->lpni_healthv));
3711                 list_add_tail(&lpni->lpni_recovery, &the_lnet.ln_mt_peerNIRecovq);
3712                 lnet_peer_ni_addref_locked(lpni);
3713         }
3714 }
3715
3716 /* Call with the ln_api_mutex held */
3717 void
3718 lnet_peer_ni_set_healthv(lnet_nid_t nid, int value, bool all)
3719 {
3720         struct lnet_peer_table *ptable;
3721         struct lnet_peer *lp;
3722         struct lnet_peer_net *lpn;
3723         struct lnet_peer_ni *lpni;
3724         int lncpt;
3725         int cpt;
3726
3727         if (the_lnet.ln_state != LNET_STATE_RUNNING)
3728                 return;
3729
3730         if (!all) {
3731                 lnet_net_lock(LNET_LOCK_EX);
3732                 lpni = lnet_find_peer_ni_locked(nid);
3733                 if (!lpni) {
3734                         lnet_net_unlock(LNET_LOCK_EX);
3735                         return;
3736                 }
3737                 atomic_set(&lpni->lpni_healthv, value);
3738                 lnet_peer_ni_add_to_recoveryq_locked(lpni);
3739                 lnet_peer_ni_decref_locked(lpni);
3740                 lnet_net_unlock(LNET_LOCK_EX);
3741                 return;
3742         }
3743
3744         lncpt = cfs_percpt_number(the_lnet.ln_peer_tables);
3745
3746         /*
3747          * Walk all the peers and reset the healhv for each one to the
3748          * maximum value.
3749          */
3750         lnet_net_lock(LNET_LOCK_EX);
3751         for (cpt = 0; cpt < lncpt; cpt++) {
3752                 ptable = the_lnet.ln_peer_tables[cpt];
3753                 list_for_each_entry(lp, &ptable->pt_peer_list, lp_peer_list) {
3754                         list_for_each_entry(lpn, &lp->lp_peer_nets, lpn_peer_nets) {
3755                                 list_for_each_entry(lpni, &lpn->lpn_peer_nis,
3756                                                     lpni_peer_nis) {
3757                                         atomic_set(&lpni->lpni_healthv, value);
3758                                         lnet_peer_ni_add_to_recoveryq_locked(lpni);
3759                                 }
3760                         }
3761                 }
3762         }
3763         lnet_net_unlock(LNET_LOCK_EX);
3764 }
3765