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  *
  31  * lnet/lnet/peer.c
  32  */
  33
  34 #define DEBUG_SUBSYSTEM S_LNET
  35
  36 #include <linux/sched.h>
  37 #ifdef HAVE_SCHED_HEADERS
  38 #include <linux/sched/signal.h>
  39 #endif
  40 #include <linux/uaccess.h>
  41
  42 #include <lnet/udsp.h>
  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_NID_NET(&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                 CFS_FREE_PTR_ARRAY(hash, LNET_PEER_HASH_SIZE);
 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(struct lnet_nid *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         INIT_LIST_HEAD(&lpni->lpni_rtr_pref_nids);
 170         LNetInvalidateMDHandle(&lpni->lpni_recovery_ping_mdh);
 171         kref_init(&lpni->lpni_kref);
 172         lpni->lpni_sel_priority = LNET_MAX_SELECTION_PRIORITY;
 173
 174         spin_lock_init(&lpni->lpni_lock);
 175
 176         if (lnet_peers_start_down())
 177                 lpni->lpni_ns_status = LNET_NI_STATUS_DOWN;
 178         else
 179                 lpni->lpni_ns_status = LNET_NI_STATUS_UP;
 180         lpni->lpni_ping_feats = LNET_PING_FEAT_INVAL;
 181         lpni->lpni_nid = *nid;
 182         lpni->lpni_cpt = cpt;
 183         atomic_set(&lpni->lpni_healthv, LNET_MAX_HEALTH_VALUE);
 184
 185         net = lnet_get_net_locked(LNET_NID_NET(nid));
 186         lpni->lpni_net = net;
 187         if (net) {
 188                 lpni->lpni_txcredits = net->net_tunables.lct_peer_tx_credits;
 189                 lpni->lpni_mintxcredits = lpni->lpni_txcredits;
 190                 lpni->lpni_rtrcredits = lnet_peer_buffer_credits(net);
 191                 lpni->lpni_minrtrcredits = lpni->lpni_rtrcredits;
 192         } else {
 193                 /*
 194                  * This peer_ni is not on a local network, so we
 195                  * cannot add the credits here. In case the net is
 196                  * added later, add the peer_ni to the remote peer ni
 197                  * list so it can be easily found and revisited.
 198                  */
 199                 /* FIXME: per-net implementation instead? */
 200                 lnet_peer_ni_addref_locked(lpni);
 201                 list_add_tail(&lpni->lpni_on_remote_peer_ni_list,
 202                               &the_lnet.ln_remote_peer_ni_list);
 203         }
 204
 205         CDEBUG(D_NET, "%p nid %s\n", lpni, libcfs_nidstr(&lpni->lpni_nid));
 206
 207         return lpni;
 208 }
 209
 210 static struct lnet_peer_net *
 211 lnet_peer_net_alloc(__u32 net_id)
 212 {
 213         struct lnet_peer_net *lpn;
 214
 215         LIBCFS_CPT_ALLOC(lpn, lnet_cpt_table(), CFS_CPT_ANY, sizeof(*lpn));
 216         if (!lpn)
 217                 return NULL;
 218
 219         INIT_LIST_HEAD(&lpn->lpn_peer_nets);
 220         INIT_LIST_HEAD(&lpn->lpn_peer_nis);
 221         lpn->lpn_net_id = net_id;
 222         lpn->lpn_sel_priority = LNET_MAX_SELECTION_PRIORITY;
 223
 224         CDEBUG(D_NET, "%p net %s\n", lpn, libcfs_net2str(lpn->lpn_net_id));
 225
 226         return lpn;
 227 }
 228
 229 void
 230 lnet_destroy_peer_net_locked(struct lnet_peer_net *lpn)
 231 {
 232         struct lnet_peer *lp;
 233
 234         CDEBUG(D_NET, "%p net %s\n", lpn, libcfs_net2str(lpn->lpn_net_id));
 235
 236         LASSERT(atomic_read(&lpn->lpn_refcount) == 0);
 237         LASSERT(list_empty(&lpn->lpn_peer_nis));
 238         LASSERT(list_empty(&lpn->lpn_peer_nets));
 239         lp = lpn->lpn_peer;
 240         lpn->lpn_peer = NULL;
 241         LIBCFS_FREE(lpn, sizeof(*lpn));
 242
 243         lnet_peer_decref_locked(lp);
 244 }
 245
 246 static struct lnet_peer *
 247 lnet_peer_alloc(struct lnet_nid *nid)
 248 {
 249         struct lnet_peer *lp;
 250
 251         LIBCFS_CPT_ALLOC(lp, lnet_cpt_table(), CFS_CPT_ANY, sizeof(*lp));
 252         if (!lp)
 253                 return NULL;
 254
 255         INIT_LIST_HEAD(&lp->lp_rtrq);
 256         INIT_LIST_HEAD(&lp->lp_routes);
 257         INIT_LIST_HEAD(&lp->lp_peer_list);
 258         INIT_LIST_HEAD(&lp->lp_peer_nets);
 259         INIT_LIST_HEAD(&lp->lp_dc_list);
 260         INIT_LIST_HEAD(&lp->lp_dc_pendq);
 261         INIT_LIST_HEAD(&lp->lp_rtr_list);
 262         init_waitqueue_head(&lp->lp_dc_waitq);
 263         spin_lock_init(&lp->lp_lock);
 264         lp->lp_primary_nid = *nid;
 265         lp->lp_disc_src_nid = LNET_ANY_NID;
 266         lp->lp_disc_dst_nid = LNET_ANY_NID;
 267         if (lnet_peers_start_down())
 268                 lp->lp_alive = false;
 269         else
 270                 lp->lp_alive = true;
 271
 272         /*
 273          * all peers created on a router should have health on
 274          * if it's not already on.
 275          */
 276         if (the_lnet.ln_routing && !lnet_health_sensitivity)
 277                 lp->lp_health_sensitivity = 1;
 278
 279         /*
 280          * Turn off discovery for loopback peer. If you're creating a peer
 281          * for the loopback interface then that was initiated when we
 282          * attempted to send a message over the loopback. There is no need
 283          * to ever use a different interface when sending messages to
 284          * myself.
 285          */
 286         if (nid_is_lo0(nid))
 287                 lp->lp_state = LNET_PEER_NO_DISCOVERY;
 288         lp->lp_cpt = lnet_nid_cpt_hash(nid, LNET_CPT_NUMBER);
 289
 290         CDEBUG(D_NET, "%p nid %s\n", lp, libcfs_nidstr(&lp->lp_primary_nid));
 291
 292         return lp;
 293 }
 294
 295 void
 296 lnet_destroy_peer_locked(struct lnet_peer *lp)
 297 {
 298         CDEBUG(D_NET, "%p nid %s\n", lp, libcfs_nidstr(&lp->lp_primary_nid));
 299
 300         LASSERT(atomic_read(&lp->lp_refcount) == 0);
 301         LASSERT(lp->lp_rtr_refcount == 0);
 302         LASSERT(list_empty(&lp->lp_peer_nets));
 303         LASSERT(list_empty(&lp->lp_peer_list));
 304         LASSERT(list_empty(&lp->lp_dc_list));
 305
 306         if (lp->lp_data)
 307                 lnet_ping_buffer_decref(lp->lp_data);
 308
 309         /*
 310          * if there are messages still on the pending queue, then make
 311          * sure to queue them on the ln_msg_resend list so they can be
 312          * resent at a later point if the discovery thread is still
 313          * running.
 314          * If the discovery thread has stopped, then the wakeup will be a
 315          * no-op, and it is expected the lnet_shutdown_lndnets() will
 316          * eventually be called, which will traverse this list and
 317          * finalize the messages on the list.
 318          * We can not resend them now because we're holding the cpt lock.
 319          * Releasing the lock can cause an inconsistent state
 320          */
 321         spin_lock(&the_lnet.ln_msg_resend_lock);
 322         spin_lock(&lp->lp_lock);
 323         list_splice(&lp->lp_dc_pendq, &the_lnet.ln_msg_resend);
 324         spin_unlock(&lp->lp_lock);
 325         spin_unlock(&the_lnet.ln_msg_resend_lock);
 326         wake_up(&the_lnet.ln_dc_waitq);
 327
 328         LIBCFS_FREE(lp, sizeof(*lp));
 329 }
 330
 331 /*
 332  * Detach a peer_ni from its peer_net. If this was the last peer_ni on
 333  * that peer_net, detach the peer_net from the peer.
 334  *
 335  * Call with lnet_net_lock/EX held
 336  */
 337 static void
 338 lnet_peer_detach_peer_ni_locked(struct lnet_peer_ni *lpni)
 339 {
 340         struct lnet_peer_table *ptable;
 341         struct lnet_peer_net *lpn;
 342         struct lnet_peer *lp;
 343
 344         /*
 345          * Belts and suspenders: gracefully handle teardown of a
 346          * partially connected peer_ni.
 347          */
 348         lpn = lpni->lpni_peer_net;
 349
 350         list_del_init(&lpni->lpni_peer_nis);
 351         /*
 352          * If there are no lpni's left, we detach lpn from
 353          * lp_peer_nets, so it cannot be found anymore.
 354          */
 355         if (list_empty(&lpn->lpn_peer_nis))
 356                 list_del_init(&lpn->lpn_peer_nets);
 357
 358         /* Update peer NID count. */
 359         lp = lpn->lpn_peer;
 360         lp->lp_nnis--;
 361
 362         /*
 363          * If there are no more peer nets, make the peer unfindable
 364          * via the peer_tables.
 365          *
 366          * Otherwise, if the peer is DISCOVERED, tell discovery to
 367          * take another look at it. This is a no-op if discovery for
 368          * this peer did the detaching.
 369          */
 370         if (list_empty(&lp->lp_peer_nets)) {
 371                 list_del_init(&lp->lp_peer_list);
 372                 ptable = the_lnet.ln_peer_tables[lp->lp_cpt];
 373                 ptable->pt_peers--;
 374         } else if (the_lnet.ln_dc_state != LNET_DC_STATE_RUNNING) {
 375                 /* Discovery isn't running, nothing to do here. */
 376         } else if (lp->lp_state & LNET_PEER_DISCOVERED) {
 377                 lnet_peer_queue_for_discovery(lp);
 378                 wake_up(&the_lnet.ln_dc_waitq);
 379         }
 380         CDEBUG(D_NET, "peer %s NID %s\n",
 381                 libcfs_nidstr(&lp->lp_primary_nid),
 382                 libcfs_nidstr(&lpni->lpni_nid));
 383 }
 384
 385 /* called with lnet_net_lock LNET_LOCK_EX held */
 386 static int
 387 lnet_peer_ni_del_locked(struct lnet_peer_ni *lpni, bool force)
 388 {
 389         struct lnet_peer_table *ptable = NULL;
 390
 391         /* don't remove a peer_ni if it's also a gateway */
 392         if (lnet_isrouter(lpni) && !force) {
 393                 CERROR("Peer NI %s is a gateway. Can not delete it\n",
 394                        libcfs_nidstr(&lpni->lpni_nid));
 395                 return -EBUSY;
 396         }
 397
 398         lnet_peer_remove_from_remote_list(lpni);
 399
 400         /* remove peer ni from the hash list. */
 401         list_del_init(&lpni->lpni_hashlist);
 402
 403         /*
 404          * indicate the peer is being deleted so the monitor thread can
 405          * remove it from the recovery queue.
 406          */
 407         spin_lock(&lpni->lpni_lock);
 408         lpni->lpni_state |= LNET_PEER_NI_DELETING;
 409         spin_unlock(&lpni->lpni_lock);
 410
 411         /* decrement the ref count on the peer table */
 412         ptable = the_lnet.ln_peer_tables[lpni->lpni_cpt];
 413
 414         /*
 415          * The peer_ni can no longer be found with a lookup. But there
 416          * can be current users, so keep track of it on the zombie
 417          * list until the reference count has gone to zero.
 418          *
 419          * The last reference may be lost in a place where the
 420          * lnet_net_lock locks only a single cpt, and that cpt may not
 421          * be lpni->lpni_cpt. So the zombie list of lnet_peer_table
 422          * has its own lock.
 423          */
 424         spin_lock(&ptable->pt_zombie_lock);
 425         list_add(&lpni->lpni_hashlist, &ptable->pt_zombie_list);
 426         ptable->pt_zombies++;
 427         spin_unlock(&ptable->pt_zombie_lock);
 428
 429         /* no need to keep this peer_ni on the hierarchy anymore */
 430         lnet_peer_detach_peer_ni_locked(lpni);
 431
 432         /* remove hashlist reference on peer_ni */
 433         lnet_peer_ni_decref_locked(lpni);
 434
 435         return 0;
 436 }
 437
 438 void lnet_peer_uninit(void)
 439 {
 440         struct lnet_peer_ni *lpni, *tmp;
 441
 442         lnet_net_lock(LNET_LOCK_EX);
 443
 444         /* remove all peer_nis from the remote peer and the hash list */
 445         list_for_each_entry_safe(lpni, tmp, &the_lnet.ln_remote_peer_ni_list,
 446                                  lpni_on_remote_peer_ni_list)
 447                 lnet_peer_ni_del_locked(lpni, false);
 448
 449         lnet_peer_tables_destroy();
 450
 451         lnet_net_unlock(LNET_LOCK_EX);
 452 }
 453
 454 static int
 455 lnet_peer_del_locked(struct lnet_peer *peer)
 456 {
 457         struct lnet_peer_ni *lpni = NULL, *lpni2;
 458         int rc = 0, rc2 = 0;
 459
 460         CDEBUG(D_NET, "peer %s\n", libcfs_nidstr(&peer->lp_primary_nid));
 461
 462         spin_lock(&peer->lp_lock);
 463         peer->lp_state |= LNET_PEER_MARK_DELETED;
 464         spin_unlock(&peer->lp_lock);
 465
 466         lpni = lnet_get_next_peer_ni_locked(peer, NULL, lpni);
 467         while (lpni != NULL) {
 468                 lpni2 = lnet_get_next_peer_ni_locked(peer, NULL, lpni);
 469                 rc = lnet_peer_ni_del_locked(lpni, false);
 470                 if (rc != 0)
 471                         rc2 = rc;
 472                 lpni = lpni2;
 473         }
 474
 475         return rc2;
 476 }
 477
 478 /*
 479  * Discovering this peer is taking too long. Cancel any Ping or Push
 480  * that discovery is waiting on by unlinking the relevant MDs. The
 481  * lnet_discovery_event_handler() will proceed from here and complete
 482  * the cleanup.
 483  */
 484 static void lnet_peer_cancel_discovery(struct lnet_peer *lp)
 485 {
 486         struct lnet_handle_md ping_mdh;
 487         struct lnet_handle_md push_mdh;
 488
 489         LNetInvalidateMDHandle(&ping_mdh);
 490         LNetInvalidateMDHandle(&push_mdh);
 491
 492         spin_lock(&lp->lp_lock);
 493         if (lp->lp_state & LNET_PEER_PING_SENT) {
 494                 ping_mdh = lp->lp_ping_mdh;
 495                 LNetInvalidateMDHandle(&lp->lp_ping_mdh);
 496         }
 497         if (lp->lp_state & LNET_PEER_PUSH_SENT) {
 498                 push_mdh = lp->lp_push_mdh;
 499                 LNetInvalidateMDHandle(&lp->lp_push_mdh);
 500         }
 501         spin_unlock(&lp->lp_lock);
 502
 503         if (!LNetMDHandleIsInvalid(ping_mdh))
 504                 LNetMDUnlink(ping_mdh);
 505         if (!LNetMDHandleIsInvalid(push_mdh))
 506                 LNetMDUnlink(push_mdh);
 507 }
 508
 509 static int
 510 lnet_peer_del(struct lnet_peer *peer)
 511 {
 512         int rc;
 513
 514         lnet_peer_cancel_discovery(peer);
 515         lnet_net_lock(LNET_LOCK_EX);
 516         rc = lnet_peer_del_locked(peer);
 517         lnet_net_unlock(LNET_LOCK_EX);
 518
 519         return rc;
 520 }
 521
 522 /*
 523  * Delete a NID from a peer. Call with ln_api_mutex held.
 524  *
 525  * Error codes:
 526  *  -EPERM:  Non-DLC deletion from DLC-configured peer.
 527  *  -ENOENT: No lnet_peer_ni corresponding to the nid.
 528  *  -ECHILD: The lnet_peer_ni isn't connected to the peer.
 529  *  -EBUSY:  The lnet_peer_ni is the primary, and not the only peer_ni.
 530  */
 531 static int
 532 lnet_peer_del_nid(struct lnet_peer *lp, lnet_nid_t nid4, unsigned int flags)
 533 {
 534         struct lnet_peer_ni *lpni;
 535         struct lnet_nid primary_nid = lp->lp_primary_nid;
 536         struct lnet_nid nid;
 537         int rc = 0;
 538         bool force = (flags & LNET_PEER_RTR_NI_FORCE_DEL) ? true : false;
 539
 540         lnet_nid4_to_nid(nid4, &nid);
 541         if (!(flags & LNET_PEER_CONFIGURED)) {
 542                 if (lp->lp_state & LNET_PEER_CONFIGURED) {
 543                         rc = -EPERM;
 544                         goto out;
 545                 }
 546         }
 547
 548         lpni = lnet_peer_ni_find_locked(&nid);
 549         if (!lpni) {
 550                 rc = -ENOENT;
 551                 goto out;
 552         }
 553         lnet_peer_ni_decref_locked(lpni);
 554         if (lp != lpni->lpni_peer_net->lpn_peer) {
 555                 rc = -ECHILD;
 556                 goto out;
 557         }
 558
 559         /*
 560          * This function only allows deletion of the primary NID if it
 561          * is the only NID.
 562          */
 563         if (nid_same(&nid, &lp->lp_primary_nid) && lp->lp_nnis != 1 && !force) {
 564                 rc = -EBUSY;
 565                 goto out;
 566         }
 567
 568         lnet_net_lock(LNET_LOCK_EX);
 569
 570         if (nid_same(&nid, &lp->lp_primary_nid) && lp->lp_nnis != 1 && force) {
 571                 struct lnet_peer_ni *lpni2;
 572                 /* assign the next peer_ni to be the primary */
 573                 lpni2 = lnet_get_next_peer_ni_locked(lp, NULL, lpni);
 574                 LASSERT(lpni2);
 575                 lp->lp_primary_nid = lpni2->lpni_nid;
 576         }
 577         rc = lnet_peer_ni_del_locked(lpni, force);
 578
 579         lnet_net_unlock(LNET_LOCK_EX);
 580
 581 out:
 582         CDEBUG(D_NET, "peer %s NID %s flags %#x: %d\n",
 583                libcfs_nidstr(&primary_nid), libcfs_nidstr(&nid),
 584                flags, rc);
 585
 586         return rc;
 587 }
 588
 589 static void
 590 lnet_peer_table_cleanup_locked(struct lnet_net *net,
 591                                struct lnet_peer_table *ptable)
 592 {
 593         int                      i;
 594         struct lnet_peer_ni     *next;
 595         struct lnet_peer_ni     *lpni;
 596         struct lnet_peer        *peer;
 597
 598         for (i = 0; i < LNET_PEER_HASH_SIZE; i++) {
 599                 list_for_each_entry_safe(lpni, next, &ptable->pt_hash[i],
 600                                          lpni_hashlist) {
 601                         if (net != NULL && net != lpni->lpni_net)
 602                                 continue;
 603
 604                         peer = lpni->lpni_peer_net->lpn_peer;
 605                         if (!nid_same(&peer->lp_primary_nid,
 606                                        &lpni->lpni_nid)) {
 607                                 lnet_peer_ni_del_locked(lpni, false);
 608                                 continue;
 609                         }
 610                         /*
 611                          * Removing the primary NID implies removing
 612                          * the entire peer. Advance next beyond any
 613                          * peer_ni that belongs to the same peer.
 614                          */
 615                         list_for_each_entry_from(next, &ptable->pt_hash[i],
 616                                                  lpni_hashlist) {
 617                                 if (next->lpni_peer_net->lpn_peer != peer)
 618                                         break;
 619                         }
 620                         lnet_peer_del_locked(peer);
 621                 }
 622         }
 623 }
 624
 625 static void
 626 lnet_peer_ni_finalize_wait(struct lnet_peer_table *ptable)
 627 {
 628         wait_var_event_warning(&ptable->pt_zombies,
 629                                ptable->pt_zombies == 0,
 630                                "Waiting for %d zombies on peer table\n",
 631                                ptable->pt_zombies);
 632 }
 633
 634 static void
 635 lnet_peer_table_del_rtrs_locked(struct lnet_net *net,
 636                                 struct lnet_peer_table *ptable)
 637 {
 638         struct lnet_peer_ni     *lp;
 639         struct lnet_peer_ni     *tmp;
 640         lnet_nid_t              gw_nid;
 641         int                     i;
 642
 643         for (i = 0; i < LNET_PEER_HASH_SIZE; i++) {
 644                 list_for_each_entry_safe(lp, tmp, &ptable->pt_hash[i],
 645                                          lpni_hashlist) {
 646                         if (net != lp->lpni_net)
 647                                 continue;
 648
 649                         if (!lnet_isrouter(lp))
 650                                 continue;
 651
 652                         /* FIXME handle large-addr nid */
 653                         gw_nid = lnet_nid_to_nid4(
 654                                 &lp->lpni_peer_net->lpn_peer->lp_primary_nid);
 655
 656                         lnet_net_unlock(LNET_LOCK_EX);
 657                         lnet_del_route(LNET_NET_ANY, gw_nid);
 658                         lnet_net_lock(LNET_LOCK_EX);
 659                 }
 660         }
 661 }
 662
 663 void
 664 lnet_peer_tables_cleanup(struct lnet_net *net)
 665 {
 666         int i;
 667         struct lnet_peer_table *ptable;
 668
 669         LASSERT(the_lnet.ln_state != LNET_STATE_SHUTDOWN || net != NULL);
 670         /* If just deleting the peers for a NI, get rid of any routes these
 671          * peers are gateways for. */
 672         cfs_percpt_for_each(ptable, i, the_lnet.ln_peer_tables) {
 673                 lnet_net_lock(LNET_LOCK_EX);
 674                 lnet_peer_table_del_rtrs_locked(net, ptable);
 675                 lnet_net_unlock(LNET_LOCK_EX);
 676         }
 677
 678         /* Start the cleanup process */
 679         cfs_percpt_for_each(ptable, i, the_lnet.ln_peer_tables) {
 680                 lnet_net_lock(LNET_LOCK_EX);
 681                 lnet_peer_table_cleanup_locked(net, ptable);
 682                 lnet_net_unlock(LNET_LOCK_EX);
 683         }
 684
 685         cfs_percpt_for_each(ptable, i, the_lnet.ln_peer_tables)
 686                 lnet_peer_ni_finalize_wait(ptable);
 687 }
 688
 689 static struct lnet_peer_ni *
 690 lnet_get_peer_ni_locked(struct lnet_peer_table *ptable, struct lnet_nid *nid)
 691 {
 692         struct list_head        *peers;
 693         struct lnet_peer_ni     *lp;
 694
 695         if (the_lnet.ln_state != LNET_STATE_RUNNING)
 696                 return NULL;
 697
 698         peers = &ptable->pt_hash[lnet_nid2peerhash(nid)];
 699         list_for_each_entry(lp, peers, lpni_hashlist) {
 700                 if (nid_same(&lp->lpni_nid, nid)) {
 701                         lnet_peer_ni_addref_locked(lp);
 702                         return lp;
 703                 }
 704         }
 705
 706         return NULL;
 707 }
 708
 709 struct lnet_peer_ni *
 710 lnet_find_peer_ni_locked(lnet_nid_t nid4)
 711 {
 712         struct lnet_peer_ni *lpni;
 713         struct lnet_peer_table *ptable;
 714         int cpt;
 715         struct lnet_nid nid;
 716
 717         lnet_nid4_to_nid(nid4, &nid);
 718
 719         cpt = lnet_nid_cpt_hash(&nid, LNET_CPT_NUMBER);
 720
 721         ptable = the_lnet.ln_peer_tables[cpt];
 722         lpni = lnet_get_peer_ni_locked(ptable, &nid);
 723
 724         return lpni;
 725 }
 726
 727 struct lnet_peer_ni *
 728 lnet_peer_ni_find_locked(struct lnet_nid *nid)
 729 {
 730         struct lnet_peer_ni *lpni;
 731         struct lnet_peer_table *ptable;
 732         int cpt;
 733
 734         cpt = lnet_nid_cpt_hash(nid, LNET_CPT_NUMBER);
 735
 736         ptable = the_lnet.ln_peer_tables[cpt];
 737         lpni = lnet_get_peer_ni_locked(ptable, nid);
 738
 739         return lpni;
 740 }
 741
 742 struct lnet_peer_ni *
 743 lnet_peer_get_ni_locked(struct lnet_peer *lp, lnet_nid_t nid)
 744 {
 745         struct lnet_peer_net *lpn;
 746         struct lnet_peer_ni *lpni;
 747
 748         lpn = lnet_peer_get_net_locked(lp, LNET_NIDNET(nid));
 749         if (!lpn)
 750                 return NULL;
 751
 752         list_for_each_entry(lpni, &lpn->lpn_peer_nis, lpni_peer_nis) {
 753                 if (lnet_nid_to_nid4(&lpni->lpni_nid) == nid)
 754                         return lpni;
 755         }
 756
 757         return NULL;
 758 }
 759
 760 struct lnet_peer_ni *
 761 lnet_peer_ni_get_locked(struct lnet_peer *lp, struct lnet_nid *nid)
 762 {
 763         struct lnet_peer_net *lpn;
 764         struct lnet_peer_ni *lpni;
 765
 766         lpn = lnet_peer_get_net_locked(lp, LNET_NID_NET(nid));
 767         if (!lpn)
 768                 return NULL;
 769
 770         list_for_each_entry(lpni, &lpn->lpn_peer_nis, lpni_peer_nis) {
 771                 if (nid_same(&lpni->lpni_nid, nid))
 772                         return lpni;
 773         }
 774
 775         return NULL;
 776 }
 777
 778 struct lnet_peer *
 779 lnet_find_peer(lnet_nid_t nid)
 780 {
 781         struct lnet_peer_ni *lpni;
 782         struct lnet_peer *lp = NULL;
 783         int cpt;
 784
 785         cpt = lnet_net_lock_current();
 786         lpni = lnet_find_peer_ni_locked(nid);
 787         if (lpni) {
 788                 lp = lpni->lpni_peer_net->lpn_peer;
 789                 lnet_peer_addref_locked(lp);
 790                 lnet_peer_ni_decref_locked(lpni);
 791         }
 792         lnet_net_unlock(cpt);
 793
 794         return lp;
 795 }
 796
 797 struct lnet_peer_net *
 798 lnet_get_next_peer_net_locked(struct lnet_peer *lp, __u32 prev_lpn_id)
 799 {
 800         struct lnet_peer_net *net;
 801
 802         if (!prev_lpn_id) {
 803                 /* no net id provided return the first net */
 804                 net = list_first_entry_or_null(&lp->lp_peer_nets,
 805                                                struct lnet_peer_net,
 806                                                lpn_peer_nets);
 807
 808                 return net;
 809         }
 810
 811         /* find the net after the one provided */
 812         list_for_each_entry(net, &lp->lp_peer_nets, lpn_peer_nets) {
 813                 if (net->lpn_net_id == prev_lpn_id) {
 814                         /*
 815                          * if we reached the end of the list loop to the
 816                          * beginning.
 817                          */
 818                         if (net->lpn_peer_nets.next == &lp->lp_peer_nets)
 819                                 return list_first_entry_or_null(&lp->lp_peer_nets,
 820                                                                 struct lnet_peer_net,
 821                                                                 lpn_peer_nets);
 822                         else
 823                                 return list_next_entry(net, lpn_peer_nets);
 824                 }
 825         }
 826
 827         return NULL;
 828 }
 829
 830 struct lnet_peer_ni *
 831 lnet_get_next_peer_ni_locked(struct lnet_peer *peer,
 832                              struct lnet_peer_net *peer_net,
 833                              struct lnet_peer_ni *prev)
 834 {
 835         struct lnet_peer_ni *lpni;
 836         struct lnet_peer_net *net = peer_net;
 837
 838         if (!prev) {
 839                 if (!net) {
 840                         if (list_empty(&peer->lp_peer_nets))
 841                                 return NULL;
 842
 843                         net = list_entry(peer->lp_peer_nets.next,
 844                                          struct lnet_peer_net,
 845                                          lpn_peer_nets);
 846                 }
 847                 lpni = list_entry(net->lpn_peer_nis.next, struct lnet_peer_ni,
 848                                   lpni_peer_nis);
 849
 850                 return lpni;
 851         }
 852
 853         if (prev->lpni_peer_nis.next == &prev->lpni_peer_net->lpn_peer_nis) {
 854                 /*
 855                  * if you reached the end of the peer ni list and the peer
 856                  * net is specified then there are no more peer nis in that
 857                  * net.
 858                  */
 859                 if (net)
 860                         return NULL;
 861
 862                 /*
 863                  * we reached the end of this net ni list. move to the
 864                  * next net
 865                  */
 866                 if (prev->lpni_peer_net->lpn_peer_nets.next ==
 867                     &peer->lp_peer_nets)
 868                         /* no more nets and no more NIs. */
 869                         return NULL;
 870
 871                 /* get the next net */
 872                 net = list_entry(prev->lpni_peer_net->lpn_peer_nets.next,
 873                                  struct lnet_peer_net,
 874                                  lpn_peer_nets);
 875                 /* get the ni on it */
 876                 lpni = list_entry(net->lpn_peer_nis.next, struct lnet_peer_ni,
 877                                   lpni_peer_nis);
 878
 879                 return lpni;
 880         }
 881
 882         /* there are more nis left */
 883         lpni = list_entry(prev->lpni_peer_nis.next,
 884                           struct lnet_peer_ni, lpni_peer_nis);
 885
 886         return lpni;
 887 }
 888
 889 /* Call with the ln_api_mutex held */
 890 int lnet_get_peer_list(u32 *countp, u32 *sizep, struct lnet_process_id __user *ids)
 891 {
 892         struct lnet_process_id id;
 893         struct lnet_peer_table *ptable;
 894         struct lnet_peer *lp;
 895         __u32 count = 0;
 896         __u32 size = 0;
 897         int lncpt;
 898         int cpt;
 899         __u32 i;
 900         int rc;
 901
 902         rc = -ESHUTDOWN;
 903         if (the_lnet.ln_state != LNET_STATE_RUNNING)
 904                 goto done;
 905
 906         lncpt = cfs_percpt_number(the_lnet.ln_peer_tables);
 907
 908         /*
 909          * Count the number of peers, and return E2BIG if the buffer
 910          * is too small. We'll also return the desired size.
 911          */
 912         rc = -E2BIG;
 913         for (cpt = 0; cpt < lncpt; cpt++) {
 914                 ptable = the_lnet.ln_peer_tables[cpt];
 915                 count += ptable->pt_peers;
 916         }
 917         size = count * sizeof(*ids);
 918         if (size > *sizep)
 919                 goto done;
 920
 921         /*
 922          * Walk the peer lists and copy out the primary nids.
 923          * This is safe because the peer lists are only modified
 924          * while the ln_api_mutex is held. So we don't need to
 925          * hold the lnet_net_lock as well, and can therefore
 926          * directly call copy_to_user().
 927          */
 928         rc = -EFAULT;
 929         memset(&id, 0, sizeof(id));
 930         id.pid = LNET_PID_LUSTRE;
 931         i = 0;
 932         for (cpt = 0; cpt < lncpt; cpt++) {
 933                 ptable = the_lnet.ln_peer_tables[cpt];
 934                 list_for_each_entry(lp, &ptable->pt_peer_list, lp_peer_list) {
 935                         if (!nid_is_nid4(&lp->lp_primary_nid))
 936                                 continue;
 937                         if (i >= count)
 938                                 goto done;
 939                         id.nid = lnet_nid_to_nid4(&lp->lp_primary_nid);
 940                         if (copy_to_user(&ids[i], &id, sizeof(id)))
 941                                 goto done;
 942                         i++;
 943                 }
 944         }
 945         rc = 0;
 946 done:
 947         *countp = count;
 948         *sizep = size;
 949         return rc;
 950 }
 951
 952 /*
 953  * Start pushes to peers that need to be updated for a configuration
 954  * change on this node.
 955  */
 956 void
 957 lnet_push_update_to_peers(int force)
 958 {
 959         struct lnet_peer_table *ptable;
 960         struct lnet_peer *lp;
 961         int lncpt;
 962         int cpt;
 963
 964         lnet_net_lock(LNET_LOCK_EX);
 965         if (lnet_peer_discovery_disabled)
 966                 force = 0;
 967         lncpt = cfs_percpt_number(the_lnet.ln_peer_tables);
 968         for (cpt = 0; cpt < lncpt; cpt++) {
 969                 ptable = the_lnet.ln_peer_tables[cpt];
 970                 list_for_each_entry(lp, &ptable->pt_peer_list, lp_peer_list) {
 971                         if (force) {
 972                                 spin_lock(&lp->lp_lock);
 973                                 if (lp->lp_state & LNET_PEER_MULTI_RAIL)
 974                                         lp->lp_state |= LNET_PEER_FORCE_PUSH;
 975                                 spin_unlock(&lp->lp_lock);
 976                         }
 977                         if (lnet_peer_needs_push(lp))
 978                                 lnet_peer_queue_for_discovery(lp);
 979                 }
 980         }
 981         lnet_net_unlock(LNET_LOCK_EX);
 982         wake_up(&the_lnet.ln_dc_waitq);
 983 }
 984
 985 /* find the NID in the preferred gateways for the remote peer
 986  * return:
 987  *      false: list is not empty and NID is not preferred
 988  *      false: list is empty
 989  *      true: nid is found in the list
 990  */
 991 bool
 992 lnet_peer_is_pref_rtr_locked(struct lnet_peer_ni *lpni,
 993                              struct lnet_nid *gw_nid)
 994 {
 995         struct lnet_nid_list *ne;
 996
 997         CDEBUG(D_NET, "%s: rtr pref emtpy: %d\n",
 998                libcfs_nidstr(&lpni->lpni_nid),
 999                list_empty(&lpni->lpni_rtr_pref_nids));
1000
1001         if (list_empty(&lpni->lpni_rtr_pref_nids))
1002                 return false;
1003
1004         /* iterate through all the preferred NIDs and see if any of them
1005          * matches the provided gw_nid
1006          */
1007         list_for_each_entry(ne, &lpni->lpni_rtr_pref_nids, nl_list) {
1008                 CDEBUG(D_NET, "Comparing pref %s with gw %s\n",
1009                        libcfs_nidstr(&ne->nl_nid),
1010                        libcfs_nidstr(gw_nid));
1011                 if (nid_same(&ne->nl_nid, gw_nid))
1012                         return true;
1013         }
1014
1015         return false;
1016 }
1017
1018 void
1019 lnet_peer_clr_pref_rtrs(struct lnet_peer_ni *lpni)
1020 {
1021         struct list_head zombies;
1022         struct lnet_nid_list *ne;
1023         struct lnet_nid_list *tmp;
1024         int cpt = lpni->lpni_cpt;
1025
1026         INIT_LIST_HEAD(&zombies);
1027
1028         lnet_net_lock(cpt);
1029         list_splice_init(&lpni->lpni_rtr_pref_nids, &zombies);
1030         lnet_net_unlock(cpt);
1031
1032         list_for_each_entry_safe(ne, tmp, &zombies, nl_list) {
1033                 list_del(&ne->nl_list);
1034                 LIBCFS_FREE(ne, sizeof(*ne));
1035         }
1036 }
1037
1038 int
1039 lnet_peer_add_pref_rtr(struct lnet_peer_ni *lpni,
1040                        struct lnet_nid *gw_nid)
1041 {
1042         int cpt = lpni->lpni_cpt;
1043         struct lnet_nid_list *ne = NULL;
1044
1045         /* This function is called with api_mutex held. When the api_mutex
1046          * is held the list can not be modified, as it is only modified as
1047          * a result of applying a UDSP and that happens under api_mutex
1048          * lock.
1049          */
1050         __must_hold(&the_lnet.ln_api_mutex);
1051
1052         list_for_each_entry(ne, &lpni->lpni_rtr_pref_nids, nl_list) {
1053                 if (nid_same(&ne->nl_nid, gw_nid))
1054                         return -EEXIST;
1055         }
1056
1057         LIBCFS_CPT_ALLOC(ne, lnet_cpt_table(), cpt, sizeof(*ne));
1058         if (!ne)
1059                 return -ENOMEM;
1060
1061         ne->nl_nid = *gw_nid;
1062
1063         /* Lock the cpt to protect against addition and checks in the
1064          * selection algorithm
1065          */
1066         lnet_net_lock(cpt);
1067         list_add(&ne->nl_list, &lpni->lpni_rtr_pref_nids);
1068         lnet_net_unlock(cpt);
1069
1070         return 0;
1071 }
1072
1073 /*
1074  * Test whether a ni is a preferred ni for this peer_ni, e.g, whether
1075  * this is a preferred point-to-point path. Call with lnet_net_lock in
1076  * shared mmode.
1077  */
1078 bool
1079 lnet_peer_is_pref_nid_locked(struct lnet_peer_ni *lpni, struct lnet_nid *nid)
1080 {
1081         struct lnet_nid_list *ne;
1082
1083         if (lpni->lpni_pref_nnids == 0)
1084                 return false;
1085         if (lpni->lpni_pref_nnids == 1)
1086                 return nid_same(&lpni->lpni_pref.nid, nid);
1087         list_for_each_entry(ne, &lpni->lpni_pref.nids, nl_list) {
1088                 if (nid_same(&ne->nl_nid, nid))
1089                         return true;
1090         }
1091         return false;
1092 }
1093
1094 /*
1095  * Set a single ni as preferred, provided no preferred ni is already
1096  * defined. Only to be used for non-multi-rail peer_ni.
1097  */
1098 int
1099 lnet_peer_ni_set_non_mr_pref_nid(struct lnet_peer_ni *lpni,
1100                                   struct lnet_nid *nid)
1101 {
1102         int rc = 0;
1103
1104         if (!nid)
1105                 return -EINVAL;
1106         spin_lock(&lpni->lpni_lock);
1107         if (LNET_NID_IS_ANY(nid)) {
1108                 rc = -EINVAL;
1109         } else if (lpni->lpni_pref_nnids > 0) {
1110                 rc = -EPERM;
1111         } else if (lpni->lpni_pref_nnids == 0) {
1112                 lpni->lpni_pref.nid = *nid;
1113                 lpni->lpni_pref_nnids = 1;
1114                 lpni->lpni_state |= LNET_PEER_NI_NON_MR_PREF;
1115         }
1116         spin_unlock(&lpni->lpni_lock);
1117
1118         CDEBUG(D_NET, "peer %s nid %s: %d\n",
1119                libcfs_nidstr(&lpni->lpni_nid), libcfs_nidstr(nid), rc);
1120         return rc;
1121 }
1122
1123 /*
1124  * Clear the preferred NID from a non-multi-rail peer_ni, provided
1125  * this preference was set by lnet_peer_ni_set_non_mr_pref_nid().
1126  */
1127 int
1128 lnet_peer_ni_clr_non_mr_pref_nid(struct lnet_peer_ni *lpni)
1129 {
1130         int rc = 0;
1131
1132         spin_lock(&lpni->lpni_lock);
1133         if (lpni->lpni_state & LNET_PEER_NI_NON_MR_PREF) {
1134                 lpni->lpni_pref_nnids = 0;
1135                 lpni->lpni_state &= ~LNET_PEER_NI_NON_MR_PREF;
1136         } else if (lpni->lpni_pref_nnids == 0) {
1137                 rc = -ENOENT;
1138         } else {
1139                 rc = -EPERM;
1140         }
1141         spin_unlock(&lpni->lpni_lock);
1142
1143         CDEBUG(D_NET, "peer %s: %d\n",
1144                libcfs_nidstr(&lpni->lpni_nid), rc);
1145         return rc;
1146 }
1147
1148 void
1149 lnet_peer_ni_set_selection_priority(struct lnet_peer_ni *lpni, __u32 priority)
1150 {
1151         lpni->lpni_sel_priority = priority;
1152 }
1153
1154 /*
1155  * Clear the preferred NIDs from a non-multi-rail peer.
1156  */
1157 void
1158 lnet_peer_clr_non_mr_pref_nids(struct lnet_peer *lp)
1159 {
1160         struct lnet_peer_ni *lpni = NULL;
1161
1162         while ((lpni = lnet_get_next_peer_ni_locked(lp, NULL, lpni)) != NULL)
1163                 lnet_peer_ni_clr_non_mr_pref_nid(lpni);
1164 }
1165
1166 int
1167 lnet_peer_add_pref_nid(struct lnet_peer_ni *lpni, struct lnet_nid *nid)
1168 {
1169         struct lnet_peer *lp = lpni->lpni_peer_net->lpn_peer;
1170         struct lnet_nid_list *ne1 = NULL;
1171         struct lnet_nid_list *ne2 = NULL;
1172         struct lnet_nid *tmp_nid = NULL;
1173         int rc = 0;
1174
1175         if (LNET_NID_IS_ANY(nid)) {
1176                 rc = -EINVAL;
1177                 goto out;
1178         }
1179
1180         if (lpni->lpni_pref_nnids == 1 &&
1181             nid_same(&lpni->lpni_pref.nid, nid)) {
1182                 rc = -EEXIST;
1183                 goto out;
1184         }
1185
1186         /* A non-MR node may have only one preferred NI per peer_ni */
1187         if (lpni->lpni_pref_nnids > 0 &&
1188             !(lp->lp_state & LNET_PEER_MULTI_RAIL)) {
1189                 rc = -EPERM;
1190                 goto out;
1191         }
1192
1193         /* add the new preferred nid to the list of preferred nids */
1194         if (lpni->lpni_pref_nnids != 0) {
1195                 size_t alloc_size = sizeof(*ne1);
1196
1197                 if (lpni->lpni_pref_nnids == 1) {
1198                         tmp_nid = &lpni->lpni_pref.nid;
1199                         INIT_LIST_HEAD(&lpni->lpni_pref.nids);
1200                 }
1201
1202                 list_for_each_entry(ne1, &lpni->lpni_pref.nids, nl_list) {
1203                         if (nid_same(&ne1->nl_nid, nid)) {
1204                                 rc = -EEXIST;
1205                                 goto out;
1206                         }
1207                 }
1208
1209                 LIBCFS_CPT_ALLOC(ne1, lnet_cpt_table(), lpni->lpni_cpt,
1210                                  alloc_size);
1211                 if (!ne1) {
1212                         rc = -ENOMEM;
1213                         goto out;
1214                 }
1215
1216                 /* move the originally stored nid to the list */
1217                 if (lpni->lpni_pref_nnids == 1) {
1218                         LIBCFS_CPT_ALLOC(ne2, lnet_cpt_table(),
1219                                 lpni->lpni_cpt, alloc_size);
1220                         if (!ne2) {
1221                                 rc = -ENOMEM;
1222                                 goto out;
1223                         }
1224                         INIT_LIST_HEAD(&ne2->nl_list);
1225                         ne2->nl_nid = *tmp_nid;
1226                 }
1227                 ne1->nl_nid = *nid;
1228         }
1229
1230         lnet_net_lock(LNET_LOCK_EX);
1231         spin_lock(&lpni->lpni_lock);
1232         if (lpni->lpni_pref_nnids == 0) {
1233                 lpni->lpni_pref.nid = *nid;
1234         } else {
1235                 if (ne2)
1236                         list_add_tail(&ne2->nl_list, &lpni->lpni_pref.nids);
1237                 list_add_tail(&ne1->nl_list, &lpni->lpni_pref.nids);
1238         }
1239         lpni->lpni_pref_nnids++;
1240         lpni->lpni_state &= ~LNET_PEER_NI_NON_MR_PREF;
1241         spin_unlock(&lpni->lpni_lock);
1242         lnet_net_unlock(LNET_LOCK_EX);
1243
1244 out:
1245         if (rc == -EEXIST && (lpni->lpni_state & LNET_PEER_NI_NON_MR_PREF)) {
1246                 spin_lock(&lpni->lpni_lock);
1247                 lpni->lpni_state &= ~LNET_PEER_NI_NON_MR_PREF;
1248                 spin_unlock(&lpni->lpni_lock);
1249         }
1250         CDEBUG(D_NET, "peer %s nid %s: %d\n",
1251                libcfs_nidstr(&lp->lp_primary_nid), libcfs_nidstr(nid), rc);
1252         return rc;
1253 }
1254
1255 int
1256 lnet_peer_del_pref_nid(struct lnet_peer_ni *lpni, struct lnet_nid *nid)
1257 {
1258         struct lnet_peer *lp = lpni->lpni_peer_net->lpn_peer;
1259         struct lnet_nid_list *ne = NULL;
1260         int rc = 0;
1261
1262         if (lpni->lpni_pref_nnids == 0) {
1263                 rc = -ENOENT;
1264                 goto out;
1265         }
1266
1267         if (lpni->lpni_pref_nnids == 1) {
1268                 if (!nid_same(&lpni->lpni_pref.nid, nid)) {
1269                         rc = -ENOENT;
1270                         goto out;
1271                 }
1272         } else {
1273                 list_for_each_entry(ne, &lpni->lpni_pref.nids, nl_list) {
1274                         if (nid_same(&ne->nl_nid, nid))
1275                                 goto remove_nid_entry;
1276                 }
1277                 rc = -ENOENT;
1278                 ne = NULL;
1279                 goto out;
1280         }
1281
1282 remove_nid_entry:
1283         lnet_net_lock(LNET_LOCK_EX);
1284         spin_lock(&lpni->lpni_lock);
1285         if (lpni->lpni_pref_nnids == 1)
1286                 lpni->lpni_pref.nid = LNET_ANY_NID;
1287         else {
1288                 list_del_init(&ne->nl_list);
1289                 if (lpni->lpni_pref_nnids == 2) {
1290                         struct lnet_nid_list *ne, *tmp;
1291
1292                         list_for_each_entry_safe(ne, tmp,
1293                                                  &lpni->lpni_pref.nids,
1294                                                  nl_list) {
1295                                 lpni->lpni_pref.nid = ne->nl_nid;
1296                                 list_del_init(&ne->nl_list);
1297                                 LIBCFS_FREE(ne, sizeof(*ne));
1298                         }
1299                 }
1300         }
1301         lpni->lpni_pref_nnids--;
1302         lpni->lpni_state &= ~LNET_PEER_NI_NON_MR_PREF;
1303         spin_unlock(&lpni->lpni_lock);
1304         lnet_net_unlock(LNET_LOCK_EX);
1305
1306         if (ne)
1307                 LIBCFS_FREE(ne, sizeof(*ne));
1308 out:
1309         CDEBUG(D_NET, "peer %s nid %s: %d\n",
1310                libcfs_nidstr(&lp->lp_primary_nid), libcfs_nidstr(nid), rc);
1311         return rc;
1312 }
1313
1314 void
1315 lnet_peer_clr_pref_nids(struct lnet_peer_ni *lpni)
1316 {
1317         struct list_head zombies;
1318         struct lnet_nid_list *ne;
1319         struct lnet_nid_list *tmp;
1320
1321         INIT_LIST_HEAD(&zombies);
1322
1323         lnet_net_lock(LNET_LOCK_EX);
1324         if (lpni->lpni_pref_nnids == 1)
1325                 lpni->lpni_pref.nid = LNET_ANY_NID;
1326         else if (lpni->lpni_pref_nnids > 1)
1327                 list_splice_init(&lpni->lpni_pref.nids, &zombies);
1328         lpni->lpni_pref_nnids = 0;
1329         lnet_net_unlock(LNET_LOCK_EX);
1330
1331         list_for_each_entry_safe(ne, tmp, &zombies, nl_list) {
1332                 list_del_init(&ne->nl_list);
1333                 LIBCFS_FREE(ne, sizeof(*ne));
1334         }
1335 }
1336
1337 lnet_nid_t
1338 lnet_peer_primary_nid_locked(lnet_nid_t nid)
1339 {
1340         /* FIXME handle large-addr nid */
1341         struct lnet_peer_ni *lpni;
1342         lnet_nid_t primary_nid = nid;
1343
1344         lpni = lnet_find_peer_ni_locked(nid);
1345         if (lpni) {
1346                 primary_nid = lnet_nid_to_nid4(
1347                         &lpni->lpni_peer_net->lpn_peer->lp_primary_nid);
1348                 lnet_peer_ni_decref_locked(lpni);
1349         }
1350
1351         return primary_nid;
1352 }
1353
1354 bool
1355 lnet_is_discovery_disabled_locked(struct lnet_peer *lp)
1356 __must_hold(&lp->lp_lock)
1357 {
1358         if (lnet_peer_discovery_disabled)
1359                 return true;
1360
1361         if (!(lp->lp_state & LNET_PEER_MULTI_RAIL) ||
1362             (lp->lp_state & LNET_PEER_NO_DISCOVERY)) {
1363                 return true;
1364         }
1365
1366         return false;
1367 }
1368
1369 /*
1370  * Peer Discovery
1371  */
1372 bool
1373 lnet_is_discovery_disabled(struct lnet_peer *lp)
1374 {
1375         bool rc = false;
1376
1377         spin_lock(&lp->lp_lock);
1378         rc = lnet_is_discovery_disabled_locked(lp);
1379         spin_unlock(&lp->lp_lock);
1380
1381         return rc;
1382 }
1383
1384 int
1385 LNetAddPeer(lnet_nid_t *nids, __u32 num_nids)
1386 {
1387         lnet_nid_t pnid = 0;
1388         bool mr;
1389         int i, rc;
1390
1391         if (!nids || num_nids < 1)
1392                 return -EINVAL;
1393
1394         rc = LNetNIInit(LNET_PID_ANY);
1395         if (rc < 0)
1396                 return rc;
1397
1398         mutex_lock(&the_lnet.ln_api_mutex);
1399
1400         mr = lnet_peer_discovery_disabled == 0;
1401
1402         rc = 0;
1403         for (i = 0; i < num_nids; i++) {
1404                 if (nids[i] == LNET_NID_LO_0)
1405                         continue;
1406
1407                 if (!pnid) {
1408                         pnid = nids[i];
1409                         rc = lnet_add_peer_ni(pnid, LNET_NID_ANY, mr, true);
1410                 } else if (lnet_peer_discovery_disabled) {
1411                         rc = lnet_add_peer_ni(nids[i], LNET_NID_ANY, mr, true);
1412                 } else {
1413                         rc = lnet_add_peer_ni(pnid, nids[i], mr, true);
1414                 }
1415
1416                 if (rc && rc != -EEXIST)
1417                         goto unlock;
1418         }
1419
1420 unlock:
1421         mutex_unlock(&the_lnet.ln_api_mutex);
1422
1423         LNetNIFini();
1424
1425         return rc == -EEXIST ? 0 : rc;
1426 }
1427 EXPORT_SYMBOL(LNetAddPeer);
1428
1429 /* FIXME support large-addr nid */
1430 lnet_nid_t
1431 LNetPrimaryNID(lnet_nid_t nid)
1432 {
1433         struct lnet_peer *lp;
1434         struct lnet_peer_ni *lpni;
1435         lnet_nid_t primary_nid = nid;
1436         int rc = 0;
1437         int cpt;
1438
1439         if (nid == LNET_NID_LO_0)
1440                 return LNET_NID_LO_0;
1441
1442         cpt = lnet_net_lock_current();
1443         lpni = lnet_nid2peerni_locked(nid, LNET_NID_ANY, cpt);
1444         if (IS_ERR(lpni)) {
1445                 rc = PTR_ERR(lpni);
1446                 goto out_unlock;
1447         }
1448         lp = lpni->lpni_peer_net->lpn_peer;
1449
1450         /* If discovery is disabled locally then we needn't bother running
1451          * discovery here because discovery will not modify whatever
1452          * primary NID is currently set for this peer. If the specified peer is
1453          * down then this discovery can introduce long delays into the mount
1454          * process, so skip it if it isn't necessary.
1455          */
1456         while (!lnet_peer_discovery_disabled && !lnet_peer_is_uptodate(lp)) {
1457                 spin_lock(&lp->lp_lock);
1458                 /* force a full discovery cycle */
1459                 lp->lp_state |= LNET_PEER_FORCE_PING | LNET_PEER_FORCE_PUSH;
1460                 spin_unlock(&lp->lp_lock);
1461
1462                 rc = lnet_discover_peer_locked(lpni, cpt, true);
1463                 if (rc)
1464                         goto out_decref;
1465                 /* The lpni (or lp) for this NID may have changed and our ref is
1466                  * the only thing keeping the old one around. Release the ref
1467                  * and lookup the lpni again
1468                  */
1469                 lnet_peer_ni_decref_locked(lpni);
1470                 lpni = lnet_find_peer_ni_locked(nid);
1471                 if (!lpni) {
1472                         rc = -ENOENT;
1473                         goto out_unlock;
1474                 }
1475                 lp = lpni->lpni_peer_net->lpn_peer;
1476
1477                 /* If we find that the peer has discovery disabled then we will
1478                  * not modify whatever primary NID is currently set for this
1479                  * peer. Thus, we can break out of this loop even if the peer
1480                  * is not fully up to date.
1481                  */
1482                 if (lnet_is_discovery_disabled(lp))
1483                         break;
1484         }
1485         primary_nid = lnet_nid_to_nid4(&lp->lp_primary_nid);
1486 out_decref:
1487         lnet_peer_ni_decref_locked(lpni);
1488 out_unlock:
1489         lnet_net_unlock(cpt);
1490
1491         CDEBUG(D_NET, "NID %s primary NID %s rc %d\n", libcfs_nid2str(nid),
1492                libcfs_nid2str(primary_nid), rc);
1493         return primary_nid;
1494 }
1495 EXPORT_SYMBOL(LNetPrimaryNID);
1496
1497 struct lnet_peer_net *
1498 lnet_peer_get_net_locked(struct lnet_peer *peer, __u32 net_id)
1499 {
1500         struct lnet_peer_net *peer_net;
1501         list_for_each_entry(peer_net, &peer->lp_peer_nets, lpn_peer_nets) {
1502                 if (peer_net->lpn_net_id == net_id)
1503                         return peer_net;
1504         }
1505         return NULL;
1506 }
1507
1508 /*
1509  * Attach a peer_ni to a peer_net and peer. This function assumes
1510  * peer_ni is not already attached to the peer_net/peer. The peer_ni
1511  * may be attached to a different peer, in which case it will be
1512  * properly detached first. The whole operation is done atomically.
1513  *
1514  * This function consumes the reference on lpni and Always returns 0.
1515  * This is the last function called from functions that do return an
1516  * int, so returning 0 here allows the compiler to do a tail call.
1517  */
1518 static int
1519 lnet_peer_attach_peer_ni(struct lnet_peer *lp,
1520                                 struct lnet_peer_net *lpn,
1521                                 struct lnet_peer_ni *lpni,
1522                                 unsigned flags)
1523 {
1524         struct lnet_peer_table *ptable;
1525         bool new_lpn = false;
1526         int rc;
1527
1528         /* Install the new peer_ni */
1529         lnet_net_lock(LNET_LOCK_EX);
1530         /* Add peer_ni to global peer table hash, if necessary. */
1531         if (list_empty(&lpni->lpni_hashlist)) {
1532                 int hash = lnet_nid2peerhash(&lpni->lpni_nid);
1533
1534                 ptable = the_lnet.ln_peer_tables[lpni->lpni_cpt];
1535                 list_add_tail(&lpni->lpni_hashlist, &ptable->pt_hash[hash]);
1536                 ptable->pt_version++;
1537                 lnet_peer_ni_addref_locked(lpni);
1538         }
1539
1540         /* Detach the peer_ni from an existing peer, if necessary. */
1541         if (lpni->lpni_peer_net) {
1542                 LASSERT(lpni->lpni_peer_net != lpn);
1543                 LASSERT(lpni->lpni_peer_net->lpn_peer != lp);
1544                 lnet_peer_detach_peer_ni_locked(lpni);
1545                 lnet_peer_net_decref_locked(lpni->lpni_peer_net);
1546                 lpni->lpni_peer_net = NULL;
1547         }
1548
1549         /* Add peer_ni to peer_net */
1550         lpni->lpni_peer_net = lpn;
1551         if (nid_same(&lp->lp_primary_nid, &lpni->lpni_nid))
1552                 list_add(&lpni->lpni_peer_nis, &lpn->lpn_peer_nis);
1553         else
1554                 list_add_tail(&lpni->lpni_peer_nis, &lpn->lpn_peer_nis);
1555         lnet_update_peer_net_healthv(lpni);
1556         lnet_peer_net_addref_locked(lpn);
1557
1558         /* Add peer_net to peer */
1559         if (!lpn->lpn_peer) {
1560                 new_lpn = true;
1561                 lpn->lpn_peer = lp;
1562                 if (nid_same(&lp->lp_primary_nid, &lpni->lpni_nid))
1563                         list_add(&lpn->lpn_peer_nets, &lp->lp_peer_nets);
1564                 else
1565                         list_add_tail(&lpn->lpn_peer_nets, &lp->lp_peer_nets);
1566                 lnet_peer_addref_locked(lp);
1567         }
1568
1569         /* Add peer to global peer list, if necessary */
1570         ptable = the_lnet.ln_peer_tables[lp->lp_cpt];
1571         if (list_empty(&lp->lp_peer_list)) {
1572                 list_add_tail(&lp->lp_peer_list, &ptable->pt_peer_list);
1573                 ptable->pt_peers++;
1574         }
1575
1576
1577         /* Update peer state */
1578         spin_lock(&lp->lp_lock);
1579         if (flags & LNET_PEER_CONFIGURED) {
1580                 if (!(lp->lp_state & LNET_PEER_CONFIGURED))
1581                         lp->lp_state |= LNET_PEER_CONFIGURED;
1582         }
1583         if (flags & LNET_PEER_MULTI_RAIL) {
1584                 if (!(lp->lp_state & LNET_PEER_MULTI_RAIL)) {
1585                         lp->lp_state |= LNET_PEER_MULTI_RAIL;
1586                         lnet_peer_clr_non_mr_pref_nids(lp);
1587                 }
1588         }
1589         spin_unlock(&lp->lp_lock);
1590
1591         lp->lp_nnis++;
1592
1593         /* apply UDSPs */
1594         if (new_lpn) {
1595                 rc = lnet_udsp_apply_policies_on_lpn(lpn);
1596                 if (rc)
1597                         CERROR("Failed to apply UDSPs on lpn %s\n",
1598                                libcfs_net2str(lpn->lpn_net_id));
1599         }
1600         rc = lnet_udsp_apply_policies_on_lpni(lpni);
1601         if (rc)
1602                 CERROR("Failed to apply UDSPs on lpni %s\n",
1603                        libcfs_nidstr(&lpni->lpni_nid));
1604
1605         CDEBUG(D_NET, "peer %s NID %s flags %#x\n",
1606                libcfs_nidstr(&lp->lp_primary_nid),
1607                libcfs_nidstr(&lpni->lpni_nid), flags);
1608         lnet_peer_ni_decref_locked(lpni);
1609         lnet_net_unlock(LNET_LOCK_EX);
1610
1611         return 0;
1612 }
1613
1614 /*
1615  * Create a new peer, with nid as its primary nid.
1616  *
1617  * Call with the lnet_api_mutex held.
1618  */
1619 static int
1620 lnet_peer_add(lnet_nid_t nid4, unsigned int flags)
1621 {
1622         struct lnet_nid nid;
1623         struct lnet_peer *lp;
1624         struct lnet_peer_net *lpn;
1625         struct lnet_peer_ni *lpni;
1626         int rc = 0;
1627
1628         LASSERT(nid4 != LNET_NID_ANY);
1629
1630         /*
1631          * No need for the lnet_net_lock here, because the
1632          * lnet_api_mutex is held.
1633          */
1634         lpni = lnet_find_peer_ni_locked(nid4);
1635         if (lpni) {
1636                 /* A peer with this NID already exists. */
1637                 lp = lpni->lpni_peer_net->lpn_peer;
1638                 lnet_peer_ni_decref_locked(lpni);
1639                 /*
1640                  * This is an error if the peer was configured and the
1641                  * primary NID differs or an attempt is made to change
1642                  * the Multi-Rail flag. Otherwise the assumption is
1643                  * that an existing peer is being modified.
1644                  */
1645                 if (lp->lp_state & LNET_PEER_CONFIGURED) {
1646                         if (lnet_nid_to_nid4(&lp->lp_primary_nid) != nid4)
1647                                 rc = -EEXIST;
1648                         else if ((lp->lp_state ^ flags) & LNET_PEER_MULTI_RAIL)
1649                                 rc = -EPERM;
1650                         goto out;
1651                 } else if (!(flags & LNET_PEER_CONFIGURED)) {
1652                         if (lnet_nid_to_nid4(&lp->lp_primary_nid) == nid4) {
1653                                 rc = -EEXIST;
1654                                 goto out;
1655                         }
1656                 }
1657                 /* Delete and recreate as a configured peer. */
1658                 rc = lnet_peer_del(lp);
1659                 if (rc)
1660                         goto out;
1661         }
1662
1663         /* Create peer, peer_net, and peer_ni. */
1664         rc = -ENOMEM;
1665         lnet_nid4_to_nid(nid4, &nid);
1666         lp = lnet_peer_alloc(&nid);
1667         if (!lp)
1668                 goto out;
1669         lpn = lnet_peer_net_alloc(LNET_NID_NET(&nid));
1670         if (!lpn)
1671                 goto out_free_lp;
1672         lpni = lnet_peer_ni_alloc(&nid);
1673         if (!lpni)
1674                 goto out_free_lpn;
1675
1676         return lnet_peer_attach_peer_ni(lp, lpn, lpni, flags);
1677
1678 out_free_lpn:
1679         LIBCFS_FREE(lpn, sizeof(*lpn));
1680 out_free_lp:
1681         LIBCFS_FREE(lp, sizeof(*lp));
1682 out:
1683         CDEBUG(D_NET, "peer %s NID flags %#x: %d\n",
1684                libcfs_nid2str(nid4), flags, rc);
1685         return rc;
1686 }
1687
1688 /*
1689  * Add a NID to a peer. Call with ln_api_mutex held.
1690  *
1691  * Error codes:
1692  *  -EPERM:    Non-DLC addition to a DLC-configured peer.
1693  *  -EEXIST:   The NID was configured by DLC for a different peer.
1694  *  -ENOMEM:   Out of memory.
1695  *  -ENOTUNIQ: Adding a second peer NID on a single network on a
1696  *             non-multi-rail peer.
1697  */
1698 static int
1699 lnet_peer_add_nid(struct lnet_peer *lp, lnet_nid_t nid4, unsigned int flags)
1700 {
1701         struct lnet_peer_net *lpn;
1702         struct lnet_peer_ni *lpni;
1703         struct lnet_nid nid;
1704         int rc = 0;
1705
1706         LASSERT(lp);
1707         LASSERT(nid4 != LNET_NID_ANY);
1708
1709         lnet_nid4_to_nid(nid4, &nid);
1710
1711         /* A configured peer can only be updated through configuration. */
1712         if (!(flags & LNET_PEER_CONFIGURED)) {
1713                 if (lp->lp_state & LNET_PEER_CONFIGURED) {
1714                         rc = -EPERM;
1715                         goto out;
1716                 }
1717         }
1718
1719         /*
1720          * The MULTI_RAIL flag can be set but not cleared, because
1721          * that would leave the peer struct in an invalid state.
1722          */
1723         if (flags & LNET_PEER_MULTI_RAIL) {
1724                 spin_lock(&lp->lp_lock);
1725                 if (!(lp->lp_state & LNET_PEER_MULTI_RAIL)) {
1726                         lp->lp_state |= LNET_PEER_MULTI_RAIL;
1727                         lnet_peer_clr_non_mr_pref_nids(lp);
1728                 }
1729                 spin_unlock(&lp->lp_lock);
1730         } else if (lp->lp_state & LNET_PEER_MULTI_RAIL) {
1731                 rc = -EPERM;
1732                 goto out;
1733         }
1734
1735         lpni = lnet_find_peer_ni_locked(nid4);
1736         if (lpni) {
1737                 /*
1738                  * A peer_ni already exists. This is only a problem if
1739                  * it is not connected to this peer and was configured
1740                  * by DLC.
1741                  */
1742                 if (lpni->lpni_peer_net->lpn_peer == lp)
1743                         goto out_free_lpni;
1744                 if (lnet_peer_ni_is_configured(lpni)) {
1745                         rc = -EEXIST;
1746                         goto out_free_lpni;
1747                 }
1748                 /* If this is the primary NID, destroy the peer. */
1749                 if (lnet_peer_ni_is_primary(lpni)) {
1750                         struct lnet_peer *rtr_lp =
1751                                 lpni->lpni_peer_net->lpn_peer;
1752                         int rtr_refcount = rtr_lp->lp_rtr_refcount;
1753                         /*
1754                          * if we're trying to delete a router it means
1755                          * we're moving this peer NI to a new peer so must
1756                          * transfer router properties to the new peer
1757                          */
1758                         if (rtr_refcount > 0) {
1759                                 flags |= LNET_PEER_RTR_NI_FORCE_DEL;
1760                                 lnet_rtr_transfer_to_peer(rtr_lp, lp);
1761                         }
1762                         lnet_peer_del(lpni->lpni_peer_net->lpn_peer);
1763                         lnet_peer_ni_decref_locked(lpni);
1764                         lpni = lnet_peer_ni_alloc(&nid);
1765                         if (!lpni) {
1766                                 rc = -ENOMEM;
1767                                 goto out_free_lpni;
1768                         }
1769                 }
1770         } else {
1771                 lpni = lnet_peer_ni_alloc(&nid);
1772                 if (!lpni) {
1773                         rc = -ENOMEM;
1774                         goto out_free_lpni;
1775                 }
1776         }
1777
1778         /*
1779          * Get the peer_net. Check that we're not adding a second
1780          * peer_ni on a peer_net of a non-multi-rail peer.
1781          */
1782         lpn = lnet_peer_get_net_locked(lp, LNET_NIDNET(nid4));
1783         if (!lpn) {
1784                 lpn = lnet_peer_net_alloc(LNET_NIDNET(nid4));
1785                 if (!lpn) {
1786                         rc = -ENOMEM;
1787                         goto out_free_lpni;
1788                 }
1789         } else if (!(lp->lp_state & LNET_PEER_MULTI_RAIL)) {
1790                 rc = -ENOTUNIQ;
1791                 goto out_free_lpni;
1792         }
1793
1794         return lnet_peer_attach_peer_ni(lp, lpn, lpni, flags);
1795
1796 out_free_lpni:
1797         lnet_peer_ni_decref_locked(lpni);
1798 out:
1799         CDEBUG(D_NET, "peer %s NID %s flags %#x: %d\n",
1800                libcfs_nidstr(&lp->lp_primary_nid), libcfs_nid2str(nid4),
1801                flags, rc);
1802         return rc;
1803 }
1804
1805 /*
1806  * Update the primary NID of a peer, if possible.
1807  *
1808  * Call with the lnet_api_mutex held.
1809  */
1810 static int
1811 lnet_peer_set_primary_nid(struct lnet_peer *lp, lnet_nid_t nid,
1812                           unsigned int flags)
1813 {
1814         struct lnet_nid old = lp->lp_primary_nid;
1815         int rc = 0;
1816
1817         if (lnet_nid_to_nid4(&lp->lp_primary_nid) == nid)
1818                 goto out;
1819
1820         lnet_nid4_to_nid(nid, &lp->lp_primary_nid);
1821
1822         rc = lnet_peer_add_nid(lp, nid, flags);
1823         if (rc) {
1824                 lp->lp_primary_nid = old;
1825                 goto out;
1826         }
1827 out:
1828         CDEBUG(D_NET, "peer %s NID %s: %d\n",
1829                libcfs_nidstr(&old), libcfs_nid2str(nid), rc);
1830
1831         return rc;
1832 }
1833
1834 /*
1835  * lpni creation initiated due to traffic either sending or receiving.
1836  */
1837 static int
1838 lnet_peer_ni_traffic_add(struct lnet_nid *nid, struct lnet_nid *pref)
1839 {
1840         struct lnet_peer *lp;
1841         struct lnet_peer_net *lpn;
1842         struct lnet_peer_ni *lpni;
1843         unsigned flags = 0;
1844         int rc = 0;
1845
1846         if (LNET_NID_IS_ANY(nid)) {
1847                 rc = -EINVAL;
1848                 goto out;
1849         }
1850
1851         /* lnet_net_lock is not needed here because ln_api_lock is held */
1852         lpni = lnet_peer_ni_find_locked(nid);
1853         if (lpni) {
1854                 /*
1855                  * We must have raced with another thread. Since we
1856                  * know next to nothing about a peer_ni created by
1857                  * traffic, we just assume everything is ok and
1858                  * return.
1859                  */
1860                 lnet_peer_ni_decref_locked(lpni);
1861                 goto out;
1862         }
1863
1864         /* Create peer, peer_net, and peer_ni. */
1865         rc = -ENOMEM;
1866         lp = lnet_peer_alloc(nid);
1867         if (!lp)
1868                 goto out;
1869         lpn = lnet_peer_net_alloc(LNET_NID_NET(nid));
1870         if (!lpn)
1871                 goto out_free_lp;
1872         lpni = lnet_peer_ni_alloc(nid);
1873         if (!lpni)
1874                 goto out_free_lpn;
1875         lnet_peer_ni_set_non_mr_pref_nid(lpni, pref);
1876
1877         return lnet_peer_attach_peer_ni(lp, lpn, lpni, flags);
1878
1879 out_free_lpn:
1880         LIBCFS_FREE(lpn, sizeof(*lpn));
1881 out_free_lp:
1882         LIBCFS_FREE(lp, sizeof(*lp));
1883 out:
1884         CDEBUG(D_NET, "peer %s: %d\n", libcfs_nidstr(nid), rc);
1885         return rc;
1886 }
1887
1888 /*
1889  * Implementation of IOC_LIBCFS_ADD_PEER_NI.
1890  *
1891  * This API handles the following combinations:
1892  *   Create a peer with its primary NI if only the prim_nid is provided
1893  *   Add a NID to a peer identified by the prim_nid. The peer identified
1894  *   by the prim_nid must already exist.
1895  *   The peer being created may be non-MR.
1896  *
1897  * The caller must hold ln_api_mutex. This prevents the peer from
1898  * being created/modified/deleted by a different thread.
1899  */
1900 int
1901 lnet_add_peer_ni(lnet_nid_t prim_nid, lnet_nid_t nid, bool mr, bool temp)
1902 {
1903         struct lnet_peer *lp = NULL;
1904         struct lnet_peer_ni *lpni;
1905         unsigned int flags = 0;
1906
1907         /* The prim_nid must always be specified */
1908         if (prim_nid == LNET_NID_ANY)
1909                 return -EINVAL;
1910
1911         if (!temp)
1912                 flags = LNET_PEER_CONFIGURED;
1913
1914         if (mr)
1915                 flags |= LNET_PEER_MULTI_RAIL;
1916
1917         /*
1918          * If nid isn't specified, we must create a new peer with
1919          * prim_nid as its primary nid.
1920          */
1921         if (nid == LNET_NID_ANY)
1922                 return lnet_peer_add(prim_nid, flags);
1923
1924         /* Look up the prim_nid, which must exist. */
1925         lpni = lnet_find_peer_ni_locked(prim_nid);
1926         if (!lpni)
1927                 return -ENOENT;
1928         lnet_peer_ni_decref_locked(lpni);
1929         lp = lpni->lpni_peer_net->lpn_peer;
1930
1931         /* Peer must have been configured. */
1932         if (!temp && !(lp->lp_state & LNET_PEER_CONFIGURED)) {
1933                 CDEBUG(D_NET, "peer %s was not configured\n",
1934                        libcfs_nid2str(prim_nid));
1935                 return -ENOENT;
1936         }
1937
1938         /* Primary NID must match */
1939         if (lnet_nid_to_nid4(&lp->lp_primary_nid) != prim_nid) {
1940                 CDEBUG(D_NET, "prim_nid %s is not primary for peer %s\n",
1941                        libcfs_nid2str(prim_nid),
1942                        libcfs_nidstr(&lp->lp_primary_nid));
1943                 return -ENODEV;
1944         }
1945
1946         /* Multi-Rail flag must match. */
1947         if ((lp->lp_state ^ flags) & LNET_PEER_MULTI_RAIL) {
1948                 CDEBUG(D_NET, "multi-rail state mismatch for peer %s\n",
1949                        libcfs_nid2str(prim_nid));
1950                 return -EPERM;
1951         }
1952
1953         return lnet_peer_add_nid(lp, nid, flags);
1954 }
1955
1956 /*
1957  * Implementation of IOC_LIBCFS_DEL_PEER_NI.
1958  *
1959  * This API handles the following combinations:
1960  *   Delete a NI from a peer if both prim_nid and nid are provided.
1961  *   Delete a peer if only prim_nid is provided.
1962  *   Delete a peer if its primary nid is provided.
1963  *
1964  * The caller must hold ln_api_mutex. This prevents the peer from
1965  * being modified/deleted by a different thread.
1966  */
1967 int
1968 lnet_del_peer_ni(lnet_nid_t prim_nid, lnet_nid_t nid)
1969 {
1970         struct lnet_peer *lp;
1971         struct lnet_peer_ni *lpni;
1972         unsigned flags;
1973
1974         if (prim_nid == LNET_NID_ANY)
1975                 return -EINVAL;
1976
1977         lpni = lnet_find_peer_ni_locked(prim_nid);
1978         if (!lpni)
1979                 return -ENOENT;
1980         lnet_peer_ni_decref_locked(lpni);
1981         lp = lpni->lpni_peer_net->lpn_peer;
1982
1983         if (prim_nid != lnet_nid_to_nid4(&lp->lp_primary_nid)) {
1984                 CDEBUG(D_NET, "prim_nid %s is not primary for peer %s\n",
1985                        libcfs_nid2str(prim_nid),
1986                        libcfs_nidstr(&lp->lp_primary_nid));
1987                 return -ENODEV;
1988         }
1989
1990         lnet_net_lock(LNET_LOCK_EX);
1991         if (lp->lp_rtr_refcount > 0) {
1992                 lnet_net_unlock(LNET_LOCK_EX);
1993                 CERROR("%s is a router. Can not be deleted\n",
1994                        libcfs_nid2str(prim_nid));
1995                 return -EBUSY;
1996         }
1997         lnet_net_unlock(LNET_LOCK_EX);
1998
1999         if (nid == LNET_NID_ANY || nid == lnet_nid_to_nid4(&lp->lp_primary_nid))
2000                 return lnet_peer_del(lp);
2001
2002         flags = LNET_PEER_CONFIGURED;
2003         if (lp->lp_state & LNET_PEER_MULTI_RAIL)
2004                 flags |= LNET_PEER_MULTI_RAIL;
2005
2006         return lnet_peer_del_nid(lp, nid, flags);
2007 }
2008
2009 void
2010 lnet_destroy_peer_ni_locked(struct kref *ref)
2011 {
2012         struct lnet_peer_ni *lpni = container_of(ref, struct lnet_peer_ni,
2013                                                  lpni_kref);
2014         struct lnet_peer_table *ptable;
2015         struct lnet_peer_net *lpn;
2016
2017         CDEBUG(D_NET, "%p nid %s\n", lpni, libcfs_nidstr(&lpni->lpni_nid));
2018
2019         LASSERT(kref_read(&lpni->lpni_kref) == 0);
2020         LASSERT(list_empty(&lpni->lpni_txq));
2021         LASSERT(lpni->lpni_txqnob == 0);
2022         LASSERT(list_empty(&lpni->lpni_peer_nis));
2023         LASSERT(list_empty(&lpni->lpni_on_remote_peer_ni_list));
2024
2025         lpn = lpni->lpni_peer_net;
2026         lpni->lpni_peer_net = NULL;
2027         lpni->lpni_net = NULL;
2028
2029         if (!list_empty(&lpni->lpni_hashlist)) {
2030                 /* remove the peer ni from the zombie list */
2031                 ptable = the_lnet.ln_peer_tables[lpni->lpni_cpt];
2032                 spin_lock(&ptable->pt_zombie_lock);
2033                 list_del_init(&lpni->lpni_hashlist);
2034                 ptable->pt_zombies--;
2035                 spin_unlock(&ptable->pt_zombie_lock);
2036         }
2037
2038         if (lpni->lpni_pref_nnids > 1) {
2039                 struct lnet_nid_list *ne, *tmp;
2040
2041                 list_for_each_entry_safe(ne, tmp, &lpni->lpni_pref.nids,
2042                                          nl_list) {
2043                         list_del_init(&ne->nl_list);
2044                         LIBCFS_FREE(ne, sizeof(*ne));
2045                 }
2046         }
2047         LIBCFS_FREE(lpni, sizeof(*lpni));
2048
2049         if (lpn)
2050                 lnet_peer_net_decref_locked(lpn);
2051 }
2052
2053 struct lnet_peer_ni *
2054 lnet_nid2peerni_ex(struct lnet_nid *nid, int cpt)
2055 {
2056         struct lnet_peer_ni *lpni = NULL;
2057         int rc;
2058
2059         if (the_lnet.ln_state != LNET_STATE_RUNNING)
2060                 return ERR_PTR(-ESHUTDOWN);
2061
2062         /*
2063          * find if a peer_ni already exists.
2064          * If so then just return that.
2065          */
2066         lpni = lnet_peer_ni_find_locked(nid);
2067         if (lpni)
2068                 return lpni;
2069
2070         lnet_net_unlock(cpt);
2071
2072         rc = lnet_peer_ni_traffic_add(nid, NULL);
2073         if (rc) {
2074                 lpni = ERR_PTR(rc);
2075                 goto out_net_relock;
2076         }
2077
2078         lpni = lnet_peer_ni_find_locked(nid);
2079         LASSERT(lpni);
2080
2081 out_net_relock:
2082         lnet_net_lock(cpt);
2083
2084         return lpni;
2085 }
2086
2087 /*
2088  * Get a peer_ni for the given nid, create it if necessary. Takes a
2089  * hold on the peer_ni.
2090  */
2091 struct lnet_peer_ni *
2092 lnet_peerni_by_nid_locked(struct lnet_nid *nid,
2093                         struct lnet_nid *pref, int cpt)
2094 {
2095         struct lnet_peer_ni *lpni = NULL;
2096         int rc;
2097
2098         if (the_lnet.ln_state != LNET_STATE_RUNNING)
2099                 return ERR_PTR(-ESHUTDOWN);
2100
2101         /*
2102          * find if a peer_ni already exists.
2103          * If so then just return that.
2104          */
2105         lpni = lnet_peer_ni_find_locked(nid);
2106         if (lpni)
2107                 return lpni;
2108
2109         /*
2110          * Slow path:
2111          * use the lnet_api_mutex to serialize the creation of the peer_ni
2112          * and the creation/deletion of the local ni/net. When a local ni is
2113          * created, if there exists a set of peer_nis on that network,
2114          * they need to be traversed and updated. When a local NI is
2115          * deleted, which could result in a network being deleted, then
2116          * all peer nis on that network need to be removed as well.
2117          *
2118          * Creation through traffic should also be serialized with
2119          * creation through DLC.
2120          */
2121         lnet_net_unlock(cpt);
2122         mutex_lock(&the_lnet.ln_api_mutex);
2123         /*
2124          * Shutdown is only set under the ln_api_lock, so a single
2125          * check here is sufficent.
2126          */
2127         if (the_lnet.ln_state != LNET_STATE_RUNNING) {
2128                 lpni = ERR_PTR(-ESHUTDOWN);
2129                 goto out_mutex_unlock;
2130         }
2131
2132         rc = lnet_peer_ni_traffic_add(nid, pref);
2133         if (rc) {
2134                 lpni = ERR_PTR(rc);
2135                 goto out_mutex_unlock;
2136         }
2137
2138         lpni = lnet_peer_ni_find_locked(nid);
2139         LASSERT(lpni);
2140
2141 out_mutex_unlock:
2142         mutex_unlock(&the_lnet.ln_api_mutex);
2143         lnet_net_lock(cpt);
2144
2145         /* Lock has been dropped, check again for shutdown. */
2146         if (the_lnet.ln_state != LNET_STATE_RUNNING) {
2147                 if (!IS_ERR(lpni))
2148                         lnet_peer_ni_decref_locked(lpni);
2149                 lpni = ERR_PTR(-ESHUTDOWN);
2150         }
2151
2152         return lpni;
2153 }
2154
2155 struct lnet_peer_ni *
2156 lnet_nid2peerni_locked(lnet_nid_t nid4, lnet_nid_t pref4, int cpt)
2157 {
2158         struct lnet_nid nid, pref;
2159
2160         lnet_nid4_to_nid(nid4, &nid);
2161         lnet_nid4_to_nid(pref4, &pref);
2162         if (pref4 == LNET_NID_ANY)
2163                 return lnet_peerni_by_nid_locked(&nid, NULL, cpt);
2164         else
2165                 return lnet_peerni_by_nid_locked(&nid, &pref, cpt);
2166 }
2167
2168 bool
2169 lnet_peer_gw_discovery(struct lnet_peer *lp)
2170 {
2171         bool rc = false;
2172
2173         spin_lock(&lp->lp_lock);
2174         if (lp->lp_state & LNET_PEER_RTR_DISCOVERY)
2175                 rc = true;
2176         spin_unlock(&lp->lp_lock);
2177
2178         return rc;
2179 }
2180
2181 bool
2182 lnet_peer_is_uptodate(struct lnet_peer *lp)
2183 {
2184         bool rc;
2185
2186         spin_lock(&lp->lp_lock);
2187         rc = lnet_peer_is_uptodate_locked(lp);
2188         spin_unlock(&lp->lp_lock);
2189         return rc;
2190 }
2191
2192 /*
2193  * Is a peer uptodate from the point of view of discovery?
2194  *
2195  * If it is currently being processed, obviously not.
2196  * A forced Ping or Push is also handled by the discovery thread.
2197  *
2198  * Otherwise look at whether the peer needs rediscovering.
2199  */
2200 bool
2201 lnet_peer_is_uptodate_locked(struct lnet_peer *lp)
2202 __must_hold(&lp->lp_lock)
2203 {
2204         bool rc;
2205
2206         if (lp->lp_state & (LNET_PEER_DISCOVERING |
2207                             LNET_PEER_FORCE_PING |
2208                             LNET_PEER_FORCE_PUSH)) {
2209                 rc = false;
2210         } else if (lp->lp_state & LNET_PEER_REDISCOVER) {
2211                 rc = false;
2212         } else if (lnet_peer_needs_push(lp)) {
2213                 rc = false;
2214         } else if (lp->lp_state & LNET_PEER_DISCOVERED) {
2215                 if (lp->lp_state & LNET_PEER_NIDS_UPTODATE)
2216                         rc = true;
2217                 else
2218                         rc = false;
2219         } else {
2220                 rc = false;
2221         }
2222
2223         return rc;
2224 }
2225
2226 /* Add the message to the peer's lp_dc_pendq and queue the peer for discovery */
2227 void
2228 lnet_peer_queue_message(struct lnet_peer *lp, struct lnet_msg *msg)
2229 {
2230         /* The discovery thread holds net_lock/EX and lp_lock when it splices
2231          * the lp_dc_pendq onto a local list for resending. Thus, we do the same
2232          * when adding to the list and queuing the peer to ensure that we do not
2233          * strand any messages on the lp_dc_pendq. This scheme ensures the
2234          * message will be resent even if the peer is already being discovered.
2235          * Therefore we needn't check the return value of
2236          * lnet_peer_queue_for_discovery(lp).
2237          */
2238         lnet_net_lock(LNET_LOCK_EX);
2239         spin_lock(&lp->lp_lock);
2240         list_add_tail(&msg->msg_list, &lp->lp_dc_pendq);
2241         spin_unlock(&lp->lp_lock);
2242         lnet_peer_queue_for_discovery(lp);
2243         lnet_net_unlock(LNET_LOCK_EX);
2244 }
2245
2246 /*
2247  * Queue a peer for the attention of the discovery thread.  Call with
2248  * lnet_net_lock/EX held. Returns 0 if the peer was queued, and
2249  * -EALREADY if the peer was already queued.
2250  */
2251 static int lnet_peer_queue_for_discovery(struct lnet_peer *lp)
2252 {
2253         int rc;
2254
2255         spin_lock(&lp->lp_lock);
2256         if (!(lp->lp_state & LNET_PEER_DISCOVERING))
2257                 lp->lp_state |= LNET_PEER_DISCOVERING;
2258         spin_unlock(&lp->lp_lock);
2259         if (list_empty(&lp->lp_dc_list)) {
2260                 lnet_peer_addref_locked(lp);
2261                 list_add_tail(&lp->lp_dc_list, &the_lnet.ln_dc_request);
2262                 wake_up(&the_lnet.ln_dc_waitq);
2263                 rc = 0;
2264         } else {
2265                 rc = -EALREADY;
2266         }
2267
2268         CDEBUG(D_NET, "Queue peer %s: %d\n",
2269                libcfs_nidstr(&lp->lp_primary_nid), rc);
2270
2271         return rc;
2272 }
2273
2274 /*
2275  * Discovery of a peer is complete. Wake all waiters on the peer.
2276  * Call with lnet_net_lock/EX held.
2277  */
2278 static void lnet_peer_discovery_complete(struct lnet_peer *lp)
2279 {
2280         struct lnet_msg *msg, *tmp;
2281         int rc = 0;
2282         LIST_HEAD(pending_msgs);
2283
2284         CDEBUG(D_NET, "Discovery complete. Dequeue peer %s\n",
2285                libcfs_nidstr(&lp->lp_primary_nid));
2286
2287         list_del_init(&lp->lp_dc_list);
2288         spin_lock(&lp->lp_lock);
2289         list_splice_init(&lp->lp_dc_pendq, &pending_msgs);
2290         spin_unlock(&lp->lp_lock);
2291         wake_up(&lp->lp_dc_waitq);
2292
2293         if (lp->lp_rtr_refcount > 0)
2294                 lnet_router_discovery_complete(lp);
2295
2296         lnet_net_unlock(LNET_LOCK_EX);
2297
2298         /* iterate through all pending messages and send them again */
2299         list_for_each_entry_safe(msg, tmp, &pending_msgs, msg_list) {
2300                 list_del_init(&msg->msg_list);
2301                 if (lp->lp_dc_error) {
2302                         lnet_finalize(msg, lp->lp_dc_error);
2303                         continue;
2304                 }
2305
2306                 CDEBUG(D_NET, "sending pending message %s to target %s\n",
2307                        lnet_msgtyp2str(msg->msg_type),
2308                        libcfs_id2str(msg->msg_target));
2309                 rc = lnet_send(msg->msg_src_nid_param, msg,
2310                                msg->msg_rtr_nid_param);
2311                 if (rc < 0) {
2312                         CNETERR("Error sending %s to %s: %d\n",
2313                                lnet_msgtyp2str(msg->msg_type),
2314                                libcfs_id2str(msg->msg_target), rc);
2315                         lnet_finalize(msg, rc);
2316                 }
2317         }
2318         lnet_net_lock(LNET_LOCK_EX);
2319         lnet_peer_decref_locked(lp);
2320 }
2321
2322 /*
2323  * Handle inbound push.
2324  * Like any event handler, called with lnet_res_lock/CPT held.
2325  */
2326 void lnet_peer_push_event(struct lnet_event *ev)
2327 {
2328         struct lnet_ping_buffer *pbuf;
2329         struct lnet_peer *lp;
2330
2331         pbuf = LNET_PING_INFO_TO_BUFFER(ev->md_start + ev->offset);
2332
2333         /* lnet_find_peer() adds a refcount */
2334         lp = lnet_find_peer(ev->source.nid);
2335         if (!lp) {
2336                 CDEBUG(D_NET, "Push Put from unknown %s (source %s). Ignoring...\n",
2337                        libcfs_nid2str(ev->initiator.nid),
2338                        libcfs_nid2str(ev->source.nid));
2339                 pbuf->pb_needs_post = true;
2340                 return;
2341         }
2342
2343         /* Ensure peer state remains consistent while we modify it. */
2344         spin_lock(&lp->lp_lock);
2345
2346         /*
2347          * If some kind of error happened the contents of the message
2348          * cannot be used. Clear the NIDS_UPTODATE and set the
2349          * FORCE_PING flag to trigger a ping.
2350          */
2351         if (ev->status) {
2352                 lp->lp_state &= ~LNET_PEER_NIDS_UPTODATE;
2353                 lp->lp_state |= LNET_PEER_FORCE_PING;
2354                 CDEBUG(D_NET, "Push Put error %d from %s (source %s)\n",
2355                        ev->status,
2356                        libcfs_nidstr(&lp->lp_primary_nid),
2357                        libcfs_nid2str(ev->source.nid));
2358                 goto out;
2359         }
2360
2361         /*
2362          * A push with invalid or corrupted info. Clear the UPTODATE
2363          * flag to trigger a ping.
2364          */
2365         if (lnet_ping_info_validate(&pbuf->pb_info)) {
2366                 lp->lp_state &= ~LNET_PEER_NIDS_UPTODATE;
2367                 lp->lp_state |= LNET_PEER_FORCE_PING;
2368                 CDEBUG(D_NET, "Corrupted Push from %s\n",
2369                        libcfs_nidstr(&lp->lp_primary_nid));
2370                 goto out;
2371         }
2372
2373         /*
2374          * Make sure we'll allocate the correct size ping buffer when
2375          * pinging the peer.
2376          */
2377         if (lp->lp_data_nnis < pbuf->pb_info.pi_nnis)
2378                 lp->lp_data_nnis = pbuf->pb_info.pi_nnis;
2379
2380         /*
2381          * A non-Multi-Rail peer is not supposed to be capable of
2382          * sending a push.
2383          */
2384         if (!(pbuf->pb_info.pi_features & LNET_PING_FEAT_MULTI_RAIL)) {
2385                 CERROR("Push from non-Multi-Rail peer %s dropped\n",
2386                        libcfs_nidstr(&lp->lp_primary_nid));
2387                 goto out;
2388         }
2389
2390         /*
2391          * The peer may have discovery disabled at its end. Set
2392          * NO_DISCOVERY as appropriate.
2393          */
2394         if (!(pbuf->pb_info.pi_features & LNET_PING_FEAT_DISCOVERY)) {
2395                 CDEBUG(D_NET, "Peer %s has discovery disabled\n",
2396                        libcfs_nidstr(&lp->lp_primary_nid));
2397                 /*
2398                  * Mark the peer for deletion if we already know about it
2399                  * and it's going from discovery set to no discovery set
2400                  */
2401                 if (!(lp->lp_state & (LNET_PEER_NO_DISCOVERY |
2402                                       LNET_PEER_DISCOVERING)) &&
2403                      lp->lp_state & LNET_PEER_DISCOVERED) {
2404                         CDEBUG(D_NET, "Marking %s:0x%x for deletion\n",
2405                                libcfs_nidstr(&lp->lp_primary_nid),
2406                                lp->lp_state);
2407                         lp->lp_state |= LNET_PEER_MARK_DELETION;
2408                 }
2409                 lp->lp_state |= LNET_PEER_NO_DISCOVERY;
2410         } else if (lp->lp_state & LNET_PEER_NO_DISCOVERY) {
2411                 CDEBUG(D_NET, "Peer %s has discovery enabled\n",
2412                        libcfs_nidstr(&lp->lp_primary_nid));
2413                 lp->lp_state &= ~LNET_PEER_NO_DISCOVERY;
2414         }
2415
2416         /*
2417          * Update the MULTI_RAIL flag based on the push. If the peer
2418          * was configured with DLC then the setting should match what
2419          * DLC put in.
2420          * NB: We verified above that the MR feature bit is set in pi_features
2421          */
2422         if (lp->lp_state & LNET_PEER_MULTI_RAIL) {
2423                 CDEBUG(D_NET, "peer %s(%p) is MR\n",
2424                        libcfs_nidstr(&lp->lp_primary_nid), lp);
2425         } else if (lp->lp_state & LNET_PEER_CONFIGURED) {
2426                 CWARN("Push says %s is Multi-Rail, DLC says not\n",
2427                       libcfs_nidstr(&lp->lp_primary_nid));
2428         } else if (lnet_peer_discovery_disabled) {
2429                 CDEBUG(D_NET, "peer %s(%p) not MR: DD disabled locally\n",
2430                        libcfs_nidstr(&lp->lp_primary_nid), lp);
2431         } else if (lp->lp_state & LNET_PEER_NO_DISCOVERY) {
2432                 CDEBUG(D_NET, "peer %s(%p) not MR: DD disabled remotely\n",
2433                        libcfs_nidstr(&lp->lp_primary_nid), lp);
2434         } else {
2435                 CDEBUG(D_NET, "peer %s(%p) is MR capable\n",
2436                        libcfs_nidstr(&lp->lp_primary_nid), lp);
2437                 lp->lp_state |= LNET_PEER_MULTI_RAIL;
2438                 lnet_peer_clr_non_mr_pref_nids(lp);
2439         }
2440
2441         /*
2442          * Check for truncation of the Put message. Clear the
2443          * NIDS_UPTODATE flag and set FORCE_PING to trigger a ping,
2444          * and tell discovery to allocate a bigger buffer.
2445          */
2446         if (ev->mlength < ev->rlength) {
2447                 if (the_lnet.ln_push_target_nnis < pbuf->pb_info.pi_nnis)
2448                         the_lnet.ln_push_target_nnis = pbuf->pb_info.pi_nnis;
2449                 lp->lp_state &= ~LNET_PEER_NIDS_UPTODATE;
2450                 lp->lp_state |= LNET_PEER_FORCE_PING;
2451                 CDEBUG(D_NET, "Truncated Push from %s (%d nids)\n",
2452                        libcfs_nidstr(&lp->lp_primary_nid),
2453                        pbuf->pb_info.pi_nnis);
2454                 goto out;
2455         }
2456
2457         /* always assume new data */
2458         lp->lp_peer_seqno = LNET_PING_BUFFER_SEQNO(pbuf);
2459         lp->lp_state &= ~LNET_PEER_NIDS_UPTODATE;
2460
2461         /*
2462          * If there is data present that hasn't been processed yet,
2463          * we'll replace it if the Put contained newer data and it
2464          * fits. We're racing with a Ping or earlier Push in this
2465          * case.
2466          */
2467         if (lp->lp_state & LNET_PEER_DATA_PRESENT) {
2468                 if (LNET_PING_BUFFER_SEQNO(pbuf) >
2469                         LNET_PING_BUFFER_SEQNO(lp->lp_data) &&
2470                     pbuf->pb_info.pi_nnis <= lp->lp_data->pb_nnis) {
2471                         memcpy(&lp->lp_data->pb_info, &pbuf->pb_info,
2472                                LNET_PING_INFO_SIZE(pbuf->pb_info.pi_nnis));
2473                         CDEBUG(D_NET, "Ping/Push race from %s: %u vs %u\n",
2474                               libcfs_nidstr(&lp->lp_primary_nid),
2475                               LNET_PING_BUFFER_SEQNO(pbuf),
2476                               LNET_PING_BUFFER_SEQNO(lp->lp_data));
2477                 }
2478                 goto out;
2479         }
2480
2481         /*
2482          * Allocate a buffer to copy the data. On a failure we drop
2483          * the Push and set FORCE_PING to force the discovery
2484          * thread to fix the problem by pinging the peer.
2485          */
2486         lp->lp_data = lnet_ping_buffer_alloc(lp->lp_data_nnis, GFP_ATOMIC);
2487         if (!lp->lp_data) {
2488                 lp->lp_state |= LNET_PEER_FORCE_PING;
2489                 CDEBUG(D_NET, "Cannot allocate Push buffer for %s %u\n",
2490                        libcfs_nidstr(&lp->lp_primary_nid),
2491                        LNET_PING_BUFFER_SEQNO(pbuf));
2492                 goto out;
2493         }
2494
2495         /* Success */
2496         memcpy(&lp->lp_data->pb_info, &pbuf->pb_info,
2497                LNET_PING_INFO_SIZE(pbuf->pb_info.pi_nnis));
2498         lp->lp_state |= LNET_PEER_DATA_PRESENT;
2499         CDEBUG(D_NET, "Received Push %s %u\n",
2500                libcfs_nidstr(&lp->lp_primary_nid),
2501                LNET_PING_BUFFER_SEQNO(pbuf));
2502
2503 out:
2504         /* We've processed this buffer. It can be reposted */
2505         pbuf->pb_needs_post = true;
2506
2507         /*
2508          * Queue the peer for discovery if not done, force it on the request
2509          * queue and wake the discovery thread if the peer was already queued,
2510          * because its status changed.
2511          */
2512         spin_unlock(&lp->lp_lock);
2513         lnet_net_lock(LNET_LOCK_EX);
2514         if (!lnet_peer_is_uptodate(lp) && lnet_peer_queue_for_discovery(lp)) {
2515                 list_move(&lp->lp_dc_list, &the_lnet.ln_dc_request);
2516                 wake_up(&the_lnet.ln_dc_waitq);
2517         }
2518         /* Drop refcount from lookup */
2519         lnet_peer_decref_locked(lp);
2520         lnet_net_unlock(LNET_LOCK_EX);
2521 }
2522
2523 /*
2524  * Clear the discovery error state, unless we're already discovering
2525  * this peer, in which case the error is current.
2526  */
2527 static void lnet_peer_clear_discovery_error(struct lnet_peer *lp)
2528 {
2529         spin_lock(&lp->lp_lock);
2530         if (!(lp->lp_state & LNET_PEER_DISCOVERING))
2531                 lp->lp_dc_error = 0;
2532         spin_unlock(&lp->lp_lock);
2533 }
2534
2535 /*
2536  * Peer discovery slow path. The ln_api_mutex is held on entry, and
2537  * dropped/retaken within this function. An lnet_peer_ni is passed in
2538  * because discovery could tear down an lnet_peer.
2539  */
2540 int
2541 lnet_discover_peer_locked(struct lnet_peer_ni *lpni, int cpt, bool block)
2542 {
2543         DEFINE_WAIT(wait);
2544         struct lnet_peer *lp;
2545         int rc = 0;
2546         int count = 0;
2547
2548 again:
2549         lnet_net_unlock(cpt);
2550         lnet_net_lock(LNET_LOCK_EX);
2551         lp = lpni->lpni_peer_net->lpn_peer;
2552         lnet_peer_clear_discovery_error(lp);
2553
2554         /*
2555          * We're willing to be interrupted. The lpni can become a
2556          * zombie if we race with DLC, so we must check for that.
2557          */
2558         for (;;) {
2559                 /* Keep lp alive when the lnet_net_lock is unlocked */
2560                 lnet_peer_addref_locked(lp);
2561                 prepare_to_wait(&lp->lp_dc_waitq, &wait, TASK_INTERRUPTIBLE);
2562                 if (signal_pending(current))
2563                         break;
2564                 if (the_lnet.ln_dc_state != LNET_DC_STATE_RUNNING)
2565                         break;
2566                 /*
2567                  * Don't repeat discovery if discovery is disabled. This is
2568                  * done to ensure we can use discovery as a standard ping as
2569                  * well for backwards compatibility with routers which do not
2570                  * have discovery or have discovery disabled
2571                  */
2572                 if (lnet_is_discovery_disabled(lp) && count > 0)
2573                         break;
2574                 if (lp->lp_dc_error)
2575                         break;
2576                 if (lnet_peer_is_uptodate(lp))
2577                         break;
2578                 lnet_peer_queue_for_discovery(lp);
2579                 count++;
2580                 CDEBUG(D_NET, "Discovery attempt # %d\n", count);
2581
2582                 /*
2583                  * If caller requested a non-blocking operation then
2584                  * return immediately. Once discovery is complete any
2585                  * pending messages that were stopped due to discovery
2586                  * will be transmitted.
2587                  */
2588                 if (!block)
2589                         break;
2590
2591                 lnet_net_unlock(LNET_LOCK_EX);
2592                 schedule();
2593                 finish_wait(&lp->lp_dc_waitq, &wait);
2594                 lnet_net_lock(LNET_LOCK_EX);
2595                 lnet_peer_decref_locked(lp);
2596                 /* Peer may have changed */
2597                 lp = lpni->lpni_peer_net->lpn_peer;
2598         }
2599         finish_wait(&lp->lp_dc_waitq, &wait);
2600
2601         lnet_net_unlock(LNET_LOCK_EX);
2602         lnet_net_lock(cpt);
2603         lnet_peer_decref_locked(lp);
2604         /*
2605          * The peer may have changed, so re-check and rediscover if that turns
2606          * out to have been the case. The reference count on lp ensured that
2607          * even if it was unlinked from lpni the memory could not be recycled.
2608          * Thus the check below is sufficient to determine whether the peer
2609          * changed. If the peer changed, then lp must not be dereferenced.
2610          */
2611         if (lp != lpni->lpni_peer_net->lpn_peer)
2612                 goto again;
2613
2614         if (signal_pending(current))
2615                 rc = -EINTR;
2616         else if (the_lnet.ln_dc_state != LNET_DC_STATE_RUNNING)
2617                 rc = -ESHUTDOWN;
2618         else if (lp->lp_dc_error)
2619                 rc = lp->lp_dc_error;
2620         else if (!block)
2621                 CDEBUG(D_NET, "non-blocking discovery\n");
2622         else if (!lnet_peer_is_uptodate(lp) && !lnet_is_discovery_disabled(lp))
2623                 goto again;
2624
2625         CDEBUG(D_NET, "peer %s NID %s: %d. %s\n",
2626                (lp ? libcfs_nidstr(&lp->lp_primary_nid) : "(none)"),
2627                libcfs_nidstr(&lpni->lpni_nid), rc,
2628                (!block) ? "pending discovery" : "discovery complete");
2629
2630         return rc;
2631 }
2632
2633 /* Handle an incoming ack for a push. */
2634 static void
2635 lnet_discovery_event_ack(struct lnet_peer *lp, struct lnet_event *ev)
2636 {
2637         struct lnet_ping_buffer *pbuf;
2638
2639         pbuf = LNET_PING_INFO_TO_BUFFER(ev->md_start);
2640         spin_lock(&lp->lp_lock);
2641         lp->lp_state &= ~LNET_PEER_PUSH_SENT;
2642         lp->lp_push_error = ev->status;
2643         if (ev->status)
2644                 lp->lp_state |= LNET_PEER_PUSH_FAILED;
2645         else
2646                 lp->lp_node_seqno = LNET_PING_BUFFER_SEQNO(pbuf);
2647         spin_unlock(&lp->lp_lock);
2648
2649         CDEBUG(D_NET, "peer %s ev->status %d\n",
2650                libcfs_nidstr(&lp->lp_primary_nid), ev->status);
2651 }
2652
2653 /* Handle a Reply message. This is the reply to a Ping message. */
2654 static void
2655 lnet_discovery_event_reply(struct lnet_peer *lp, struct lnet_event *ev)
2656 {
2657         struct lnet_ping_buffer *pbuf;
2658         int rc;
2659
2660         spin_lock(&lp->lp_lock);
2661
2662         lnet_nid4_to_nid(ev->target.nid, &lp->lp_disc_src_nid);
2663         lnet_nid4_to_nid(ev->source.nid, &lp->lp_disc_dst_nid);
2664
2665         /*
2666          * If some kind of error happened the contents of message
2667          * cannot be used. Set PING_FAILED to trigger a retry.
2668          */
2669         if (ev->status) {
2670                 lp->lp_state |= LNET_PEER_PING_FAILED;
2671                 lp->lp_ping_error = ev->status;
2672                 CDEBUG(D_NET, "Ping Reply error %d from %s (source %s)\n",
2673                        ev->status,
2674                        libcfs_nidstr(&lp->lp_primary_nid),
2675                        libcfs_nid2str(ev->source.nid));
2676                 goto out;
2677         }
2678
2679         pbuf = LNET_PING_INFO_TO_BUFFER(ev->md_start);
2680         if (pbuf->pb_info.pi_magic == __swab32(LNET_PROTO_PING_MAGIC))
2681                 lnet_swap_pinginfo(pbuf);
2682
2683         /*
2684          * A reply with invalid or corrupted info. Set PING_FAILED to
2685          * trigger a retry.
2686          */
2687         rc = lnet_ping_info_validate(&pbuf->pb_info);
2688         if (rc) {
2689                 lp->lp_state |= LNET_PEER_PING_FAILED;
2690                 lp->lp_ping_error = 0;
2691                 CDEBUG(D_NET, "Corrupted Ping Reply from %s: %d\n",
2692                        libcfs_nidstr(&lp->lp_primary_nid), rc);
2693                 goto out;
2694         }
2695
2696         /*
2697          * The peer may have discovery disabled at its end. Set
2698          * NO_DISCOVERY as appropriate.
2699          */
2700         if (!(pbuf->pb_info.pi_features & LNET_PING_FEAT_DISCOVERY) ||
2701             lnet_peer_discovery_disabled) {
2702                 CDEBUG(D_NET, "Peer %s has discovery disabled\n",
2703                        libcfs_nidstr(&lp->lp_primary_nid));
2704
2705                 /* Detect whether this peer has toggled discovery from on to
2706                  * off and whether we can delete and re-create the peer. Peers
2707                  * that were manually configured cannot be deleted by discovery.
2708                  * We need to delete this peer and re-create it if the peer was
2709                  * not configured manually, is currently considered DD capable,
2710                  * and either:
2711                  * 1. We've already discovered the peer (the peer has toggled
2712                  *    the discovery feature from on to off), or
2713                  * 2. The peer is considered MR, but it was not user configured
2714                  *    (this was a "temporary" peer created via the kernel APIs
2715                  *     that we're discovering for the first time)
2716                  */
2717                 if (!(lp->lp_state & (LNET_PEER_CONFIGURED |
2718                                       LNET_PEER_NO_DISCOVERY)) &&
2719                     (lp->lp_state & (LNET_PEER_DISCOVERED |
2720                                      LNET_PEER_MULTI_RAIL))) {
2721                         CDEBUG(D_NET, "Marking %s:0x%x for deletion\n",
2722                                libcfs_nidstr(&lp->lp_primary_nid),
2723                                lp->lp_state);
2724                         lp->lp_state |= LNET_PEER_MARK_DELETION;
2725                 }
2726                 lp->lp_state |= LNET_PEER_NO_DISCOVERY;
2727         } else {
2728                 CDEBUG(D_NET, "Peer %s has discovery enabled\n",
2729                        libcfs_nidstr(&lp->lp_primary_nid));
2730                 lp->lp_state &= ~LNET_PEER_NO_DISCOVERY;
2731         }
2732
2733         /*
2734          * Update the MULTI_RAIL flag based on the reply. If the peer
2735          * was configured with DLC then the setting should match what
2736          * DLC put in.
2737          */
2738         if (pbuf->pb_info.pi_features & LNET_PING_FEAT_MULTI_RAIL) {
2739                 if (lp->lp_state & LNET_PEER_MULTI_RAIL) {
2740                         CDEBUG(D_NET, "peer %s(%p) is MR\n",
2741                                libcfs_nidstr(&lp->lp_primary_nid), lp);
2742                 } else if (lp->lp_state & LNET_PEER_CONFIGURED) {
2743                         CWARN("Reply says %s is Multi-Rail, DLC says not\n",
2744                               libcfs_nidstr(&lp->lp_primary_nid));
2745                 } else if (lnet_peer_discovery_disabled) {
2746                         CDEBUG(D_NET,
2747                                "peer %s(%p) not MR: DD disabled locally\n",
2748                                libcfs_nidstr(&lp->lp_primary_nid), lp);
2749                 } else if (lp->lp_state & LNET_PEER_NO_DISCOVERY) {
2750                         CDEBUG(D_NET,
2751                                "peer %s(%p) not MR: DD disabled remotely\n",
2752                                libcfs_nidstr(&lp->lp_primary_nid), lp);
2753                 } else {
2754                         CDEBUG(D_NET, "peer %s(%p) is MR capable\n",
2755                                libcfs_nidstr(&lp->lp_primary_nid), lp);
2756                         lp->lp_state |= LNET_PEER_MULTI_RAIL;
2757                         lnet_peer_clr_non_mr_pref_nids(lp);
2758                 }
2759         } else if (lp->lp_state & LNET_PEER_MULTI_RAIL) {
2760                 if (lp->lp_state & LNET_PEER_CONFIGURED) {
2761                         CWARN("DLC says %s is Multi-Rail, Reply says not\n",
2762                               libcfs_nidstr(&lp->lp_primary_nid));
2763                 } else {
2764                         CERROR("Multi-Rail state vanished from %s\n",
2765                                libcfs_nidstr(&lp->lp_primary_nid));
2766                         lp->lp_state &= ~LNET_PEER_MULTI_RAIL;
2767                 }
2768         }
2769
2770         /*
2771          * Make sure we'll allocate the correct size ping buffer when
2772          * pinging the peer.
2773          */
2774         if (lp->lp_data_nnis < pbuf->pb_info.pi_nnis)
2775                 lp->lp_data_nnis = pbuf->pb_info.pi_nnis;
2776
2777         /*
2778          * Check for truncation of the Reply. Clear PING_SENT and set
2779          * PING_FAILED to trigger a retry.
2780          */
2781         if (pbuf->pb_nnis < pbuf->pb_info.pi_nnis) {
2782                 if (the_lnet.ln_push_target_nnis < pbuf->pb_info.pi_nnis)
2783                         the_lnet.ln_push_target_nnis = pbuf->pb_info.pi_nnis;
2784                 lp->lp_state |= LNET_PEER_PING_FAILED;
2785                 lp->lp_ping_error = 0;
2786                 CDEBUG(D_NET, "Truncated Reply from %s (%d nids)\n",
2787                        libcfs_nidstr(&lp->lp_primary_nid),
2788                        pbuf->pb_info.pi_nnis);
2789                 goto out;
2790         }
2791
2792         /*
2793          * Check the sequence numbers in the reply. These are only
2794          * available if the reply came from a Multi-Rail peer.
2795          */
2796         if (pbuf->pb_info.pi_features & LNET_PING_FEAT_MULTI_RAIL &&
2797             pbuf->pb_info.pi_nnis > 1 &&
2798             lnet_nid_to_nid4(&lp->lp_primary_nid) ==
2799             pbuf->pb_info.pi_ni[1].ns_nid) {
2800                 if (LNET_PING_BUFFER_SEQNO(pbuf) < lp->lp_peer_seqno)
2801                         CDEBUG(D_NET, "peer %s: seq# got %u have %u. peer rebooted?\n",
2802                                 libcfs_nidstr(&lp->lp_primary_nid),
2803                                 LNET_PING_BUFFER_SEQNO(pbuf),
2804                                 lp->lp_peer_seqno);
2805
2806                 lp->lp_peer_seqno = LNET_PING_BUFFER_SEQNO(pbuf);
2807         }
2808
2809         /* We're happy with the state of the data in the buffer. */
2810         CDEBUG(D_NET, "peer %s data present %u. state = 0x%x\n",
2811                libcfs_nidstr(&lp->lp_primary_nid), lp->lp_peer_seqno,
2812                lp->lp_state);
2813         if (lp->lp_state & LNET_PEER_DATA_PRESENT)
2814                 lnet_ping_buffer_decref(lp->lp_data);
2815         else
2816                 lp->lp_state |= LNET_PEER_DATA_PRESENT;
2817         lnet_ping_buffer_addref(pbuf);
2818         lp->lp_data = pbuf;
2819 out:
2820         lp->lp_state &= ~LNET_PEER_PING_SENT;
2821         spin_unlock(&lp->lp_lock);
2822
2823         lnet_net_lock(LNET_LOCK_EX);
2824         /*
2825          * If this peer is a gateway, call the routing callback to
2826          * handle the ping reply
2827          */
2828         if (lp->lp_rtr_refcount > 0)
2829                 lnet_router_discovery_ping_reply(lp);
2830         lnet_net_unlock(LNET_LOCK_EX);
2831 }
2832
2833 /*
2834  * Send event handling. Only matters for error cases, where we clean
2835  * up state on the peer and peer_ni that would otherwise be updated in
2836  * the REPLY event handler for a successful Ping, and the ACK event
2837  * handler for a successful Push.
2838  */
2839 static int
2840 lnet_discovery_event_send(struct lnet_peer *lp, struct lnet_event *ev)
2841 {
2842         int rc = 0;
2843
2844         if (!ev->status)
2845                 goto out;
2846
2847         spin_lock(&lp->lp_lock);
2848         if (ev->msg_type == LNET_MSG_GET) {
2849                 lp->lp_state &= ~LNET_PEER_PING_SENT;
2850                 lp->lp_state |= LNET_PEER_PING_FAILED;
2851                 lp->lp_ping_error = ev->status;
2852         } else { /* ev->msg_type == LNET_MSG_PUT */
2853                 lp->lp_state &= ~LNET_PEER_PUSH_SENT;
2854                 lp->lp_state |= LNET_PEER_PUSH_FAILED;
2855                 lp->lp_push_error = ev->status;
2856         }
2857         spin_unlock(&lp->lp_lock);
2858         rc = LNET_REDISCOVER_PEER;
2859 out:
2860         CDEBUG(D_NET, "%s Send to %s: %d\n",
2861                 (ev->msg_type == LNET_MSG_GET ? "Ping" : "Push"),
2862                 libcfs_nid2str(ev->target.nid), rc);
2863         return rc;
2864 }
2865
2866 /*
2867  * Unlink event handling. This event is only seen if a call to
2868  * LNetMDUnlink() caused the event to be unlinked. If this call was
2869  * made after the event was set up in LNetGet() or LNetPut() then we
2870  * assume the Ping or Push timed out.
2871  */
2872 static void
2873 lnet_discovery_event_unlink(struct lnet_peer *lp, struct lnet_event *ev)
2874 {
2875         spin_lock(&lp->lp_lock);
2876         /* We've passed through LNetGet() */
2877         if (lp->lp_state & LNET_PEER_PING_SENT) {
2878                 lp->lp_state &= ~LNET_PEER_PING_SENT;
2879                 lp->lp_state |= LNET_PEER_PING_FAILED;
2880                 lp->lp_ping_error = -ETIMEDOUT;
2881                 CDEBUG(D_NET, "Ping Unlink for message to peer %s\n",
2882                         libcfs_nidstr(&lp->lp_primary_nid));
2883         }
2884         /* We've passed through LNetPut() */
2885         if (lp->lp_state & LNET_PEER_PUSH_SENT) {
2886                 lp->lp_state &= ~LNET_PEER_PUSH_SENT;
2887                 lp->lp_state |= LNET_PEER_PUSH_FAILED;
2888                 lp->lp_push_error = -ETIMEDOUT;
2889                 CDEBUG(D_NET, "Push Unlink for message to peer %s\n",
2890                         libcfs_nidstr(&lp->lp_primary_nid));
2891         }
2892         spin_unlock(&lp->lp_lock);
2893 }
2894
2895 /*
2896  * Event handler for the discovery EQ.
2897  *
2898  * Called with lnet_res_lock(cpt) held. The cpt is the
2899  * lnet_cpt_of_cookie() of the md handle cookie.
2900  */
2901 static void lnet_discovery_event_handler(struct lnet_event *event)
2902 {
2903         struct lnet_peer *lp = event->md_user_ptr;
2904         struct lnet_ping_buffer *pbuf;
2905         int rc;
2906
2907         /* discovery needs to take another look */
2908         rc = LNET_REDISCOVER_PEER;
2909
2910         CDEBUG(D_NET, "Received event: %d\n", event->type);
2911
2912         switch (event->type) {
2913         case LNET_EVENT_ACK:
2914                 lnet_discovery_event_ack(lp, event);
2915                 break;
2916         case LNET_EVENT_REPLY:
2917                 lnet_discovery_event_reply(lp, event);
2918                 break;
2919         case LNET_EVENT_SEND:
2920                 /* Only send failure triggers a retry. */
2921                 rc = lnet_discovery_event_send(lp, event);
2922                 break;
2923         case LNET_EVENT_UNLINK:
2924                 /* LNetMDUnlink() was called */
2925                 lnet_discovery_event_unlink(lp, event);
2926                 break;
2927         default:
2928                 /* Invalid events. */
2929                 LBUG();
2930         }
2931         lnet_net_lock(LNET_LOCK_EX);
2932         if (event->unlinked) {
2933                 pbuf = LNET_PING_INFO_TO_BUFFER(event->md_start);
2934                 lnet_ping_buffer_decref(pbuf);
2935                 lnet_peer_decref_locked(lp);
2936         }
2937
2938         /* put peer back at end of request queue, if discovery not already
2939          * done */
2940         if (rc == LNET_REDISCOVER_PEER && !lnet_peer_is_uptodate(lp) &&
2941             lnet_peer_queue_for_discovery(lp)) {
2942                 list_move_tail(&lp->lp_dc_list, &the_lnet.ln_dc_request);
2943                 wake_up(&the_lnet.ln_dc_waitq);
2944         }
2945         lnet_net_unlock(LNET_LOCK_EX);
2946 }
2947
2948 /*
2949  * Build a peer from incoming data.
2950  *
2951  * The NIDs in the incoming data are supposed to be structured as follows:
2952  *  - loopback
2953  *  - primary NID
2954  *  - other NIDs in same net
2955  *  - NIDs in second net
2956  *  - NIDs in third net
2957  *  - ...
2958  * This due to the way the list of NIDs in the data is created.
2959  *
2960  * Note that this function will mark the peer uptodate unless an
2961  * ENOMEM is encontered. All other errors are due to a conflict
2962  * between the DLC configuration and what discovery sees. We treat DLC
2963  * as binding, and therefore set the NIDS_UPTODATE flag to prevent the
2964  * peer from becoming stuck in discovery.
2965  */
2966 static int lnet_peer_merge_data(struct lnet_peer *lp,
2967                                 struct lnet_ping_buffer *pbuf)
2968 {
2969         struct lnet_peer_net *lpn;
2970         struct lnet_peer_ni *lpni;
2971         lnet_nid_t *curnis = NULL;
2972         struct lnet_ni_status *addnis = NULL;
2973         lnet_nid_t *delnis = NULL;
2974         unsigned flags;
2975         int ncurnis;
2976         int naddnis;
2977         int ndelnis;
2978         int nnis = 0;
2979         int i;
2980         int j;
2981         int rc;
2982
2983         flags = LNET_PEER_DISCOVERED;
2984         if (pbuf->pb_info.pi_features & LNET_PING_FEAT_MULTI_RAIL)
2985                 flags |= LNET_PEER_MULTI_RAIL;
2986
2987         /*
2988          * Cache the routing feature for the peer; whether it is enabled
2989          * for disabled as reported by the remote peer.
2990          */
2991         spin_lock(&lp->lp_lock);
2992         if (!(pbuf->pb_info.pi_features & LNET_PING_FEAT_RTE_DISABLED))
2993                 lp->lp_state |= LNET_PEER_ROUTER_ENABLED;
2994         else
2995                 lp->lp_state &= ~LNET_PEER_ROUTER_ENABLED;
2996         spin_unlock(&lp->lp_lock);
2997
2998         nnis = max_t(int, lp->lp_nnis, pbuf->pb_info.pi_nnis);
2999         CFS_ALLOC_PTR_ARRAY(curnis, nnis);
3000         CFS_ALLOC_PTR_ARRAY(addnis, nnis);
3001         CFS_ALLOC_PTR_ARRAY(delnis, nnis);
3002         if (!curnis || !addnis || !delnis) {
3003                 rc = -ENOMEM;
3004                 goto out;
3005         }
3006         ncurnis = 0;
3007         naddnis = 0;
3008         ndelnis = 0;
3009
3010         /* Construct the list of NIDs present in peer. */
3011         lpni = NULL;
3012         while ((lpni = lnet_get_next_peer_ni_locked(lp, NULL, lpni)) != NULL)
3013                 curnis[ncurnis++] = lnet_nid_to_nid4(&lpni->lpni_nid);
3014
3015         /*
3016          * Check for NIDs in pbuf not present in curnis[].
3017          * The loop starts at 1 to skip the loopback NID.
3018          */
3019         for (i = 1; i < pbuf->pb_info.pi_nnis; i++) {
3020                 for (j = 0; j < ncurnis; j++)
3021                         if (pbuf->pb_info.pi_ni[i].ns_nid == curnis[j])
3022                                 break;
3023                 if (j == ncurnis)
3024                         addnis[naddnis++] = pbuf->pb_info.pi_ni[i];
3025         }
3026         /*
3027          * Check for NIDs in curnis[] not present in pbuf.
3028          * The nested loop starts at 1 to skip the loopback NID.
3029          *
3030          * But never add the loopback NID to delnis[]: if it is
3031          * present in curnis[] then this peer is for this node.
3032          */
3033         for (i = 0; i < ncurnis; i++) {
3034                 if (curnis[i] == LNET_NID_LO_0)
3035                         continue;
3036                 for (j = 1; j < pbuf->pb_info.pi_nnis; j++) {
3037                         if (curnis[i] == pbuf->pb_info.pi_ni[j].ns_nid) {
3038                                 /*
3039                                  * update the information we cache for the
3040                                  * peer with the latest information we
3041                                  * received
3042                                  */
3043                                 lpni = lnet_find_peer_ni_locked(curnis[i]);
3044                                 if (lpni) {
3045                                         lpni->lpni_ns_status = pbuf->pb_info.pi_ni[j].ns_status;
3046                                         lnet_peer_ni_decref_locked(lpni);
3047                                 }
3048                                 break;
3049                         }
3050                 }
3051                 if (j == pbuf->pb_info.pi_nnis)
3052                         delnis[ndelnis++] = curnis[i];
3053         }
3054
3055         /*
3056          * If we get here and the discovery is disabled then we don't want
3057          * to add or delete any NIs. We just updated the ones we have some
3058          * information on, and call it a day
3059          */
3060         rc = 0;
3061         if (lnet_is_discovery_disabled(lp))
3062                 goto out;
3063
3064         for (i = 0; i < naddnis; i++) {
3065                 rc = lnet_peer_add_nid(lp, addnis[i].ns_nid, flags);
3066                 if (rc) {
3067                         CERROR("Error adding NID %s to peer %s: %d\n",
3068                                libcfs_nid2str(addnis[i].ns_nid),
3069                                libcfs_nidstr(&lp->lp_primary_nid), rc);
3070                         if (rc == -ENOMEM)
3071                                 goto out;
3072                 }
3073                 lpni = lnet_find_peer_ni_locked(addnis[i].ns_nid);
3074                 if (lpni) {
3075                         lpni->lpni_ns_status = addnis[i].ns_status;
3076                         lnet_peer_ni_decref_locked(lpni);
3077                 }
3078         }
3079
3080         for (i = 0; i < ndelnis; i++) {
3081                 /*
3082                  * for routers it's okay to delete the primary_nid because
3083                  * the upper layers don't really rely on it. So if we're
3084                  * being told that the router changed its primary_nid
3085                  * then it's okay to delete it.
3086                  */
3087                 if (lp->lp_rtr_refcount > 0)
3088                         flags |= LNET_PEER_RTR_NI_FORCE_DEL;
3089                 rc = lnet_peer_del_nid(lp, delnis[i], flags);
3090                 if (rc) {
3091                         CERROR("Error deleting NID %s from peer %s: %d\n",
3092                                libcfs_nid2str(delnis[i]),
3093                                libcfs_nidstr(&lp->lp_primary_nid), rc);
3094                         if (rc == -ENOMEM)
3095                                 goto out;
3096                 }
3097         }
3098
3099         /* The peer net for the primary NID should be the first entry in the
3100          * peer's lp_peer_nets list, and the peer NI for the primary NID should
3101          * be the first entry in its peer net's lpn_peer_nis list.
3102          */
3103         lpni = lnet_find_peer_ni_locked(pbuf->pb_info.pi_ni[1].ns_nid);
3104         if (!lpni) {
3105                 CERROR("Internal error: Failed to lookup peer NI for primary NID: %s\n",
3106                        libcfs_nid2str(pbuf->pb_info.pi_ni[1].ns_nid));
3107                 goto out;
3108         }
3109
3110         lnet_peer_ni_decref_locked(lpni);
3111
3112         lpn = lpni->lpni_peer_net;
3113         if (lpn->lpn_peer_nets.prev != &lp->lp_peer_nets)
3114                 list_move(&lpn->lpn_peer_nets, &lp->lp_peer_nets);
3115
3116         if (lpni->lpni_peer_nis.prev != &lpni->lpni_peer_net->lpn_peer_nis)
3117                 list_move(&lpni->lpni_peer_nis,
3118                           &lpni->lpni_peer_net->lpn_peer_nis);
3119
3120         /*
3121          * Errors other than -ENOMEM are due to peers having been
3122          * configured with DLC. Ignore these because DLC overrides
3123          * Discovery.
3124          */
3125         rc = 0;
3126 out:
3127         CFS_FREE_PTR_ARRAY(curnis, nnis);
3128         CFS_FREE_PTR_ARRAY(addnis, nnis);
3129         CFS_FREE_PTR_ARRAY(delnis, nnis);
3130         lnet_ping_buffer_decref(pbuf);
3131         CDEBUG(D_NET, "peer %s (%p): %d\n",
3132                libcfs_nidstr(&lp->lp_primary_nid), lp, rc);
3133
3134         if (rc) {
3135                 spin_lock(&lp->lp_lock);
3136                 lp->lp_state &= ~LNET_PEER_NIDS_UPTODATE;
3137                 lp->lp_state |= LNET_PEER_FORCE_PING;
3138                 spin_unlock(&lp->lp_lock);
3139         }
3140         return rc;
3141 }
3142
3143 /*
3144  * The data in pbuf says lp is its primary peer, but the data was
3145  * received by a different peer. Try to update lp with the data.
3146  */
3147 static int
3148 lnet_peer_set_primary_data(struct lnet_peer *lp, struct lnet_ping_buffer *pbuf)
3149 {
3150         struct lnet_handle_md mdh;
3151
3152         /* Queue lp for discovery, and force it on the request queue. */
3153         lnet_net_lock(LNET_LOCK_EX);
3154         if (lnet_peer_queue_for_discovery(lp))
3155                 list_move(&lp->lp_dc_list, &the_lnet.ln_dc_request);
3156         lnet_net_unlock(LNET_LOCK_EX);
3157
3158         LNetInvalidateMDHandle(&mdh);
3159
3160         /*
3161          * Decide whether we can move the peer to the DATA_PRESENT state.
3162          *
3163          * We replace stale data for a multi-rail peer, repair PING_FAILED
3164          * status, and preempt FORCE_PING.
3165          *
3166          * If after that we have DATA_PRESENT, we merge it into this peer.
3167          */
3168         spin_lock(&lp->lp_lock);
3169         if (lp->lp_state & LNET_PEER_MULTI_RAIL) {
3170                 if (lp->lp_peer_seqno < LNET_PING_BUFFER_SEQNO(pbuf)) {
3171                         lp->lp_peer_seqno = LNET_PING_BUFFER_SEQNO(pbuf);
3172                 } else if (lp->lp_state & LNET_PEER_DATA_PRESENT) {
3173                         lp->lp_state &= ~LNET_PEER_DATA_PRESENT;
3174                         lnet_ping_buffer_decref(pbuf);
3175                         pbuf = lp->lp_data;
3176                         lp->lp_data = NULL;
3177                 }
3178         }
3179         if (lp->lp_state & LNET_PEER_DATA_PRESENT) {
3180                 lnet_ping_buffer_decref(lp->lp_data);
3181                 lp->lp_data = NULL;
3182                 lp->lp_state &= ~LNET_PEER_DATA_PRESENT;
3183         }
3184         if (lp->lp_state & LNET_PEER_PING_FAILED) {
3185                 mdh = lp->lp_ping_mdh;
3186                 LNetInvalidateMDHandle(&lp->lp_ping_mdh);
3187                 lp->lp_state &= ~LNET_PEER_PING_FAILED;
3188                 lp->lp_ping_error = 0;
3189         }
3190         if (lp->lp_state & LNET_PEER_FORCE_PING)
3191                 lp->lp_state &= ~LNET_PEER_FORCE_PING;
3192         lp->lp_state |= LNET_PEER_NIDS_UPTODATE;
3193         spin_unlock(&lp->lp_lock);
3194
3195         if (!LNetMDHandleIsInvalid(mdh))
3196                 LNetMDUnlink(mdh);
3197
3198         if (pbuf)
3199                 return lnet_peer_merge_data(lp, pbuf);
3200
3201         CDEBUG(D_NET, "peer %s\n", libcfs_nidstr(&lp->lp_primary_nid));
3202         return 0;
3203 }
3204
3205 static bool lnet_is_nid_in_ping_info(lnet_nid_t nid, struct lnet_ping_info *pinfo)
3206 {
3207         int i;
3208
3209         for (i = 0; i < pinfo->pi_nnis; i++) {
3210                 if (pinfo->pi_ni[i].ns_nid == nid)
3211                         return true;
3212         }
3213
3214         return false;
3215 }
3216
3217 /* Delete a peer that has been marked for deletion. NB: when this peer was added
3218  * to the discovery queue a reference was taken that will prevent the peer from
3219  * actually being freed by this function. After this function exits the
3220  * discovery thread should call lnet_peer_discovery_complete() which will
3221  * drop that reference as well as wake any waiters that may also be holding a
3222  * ref on the peer
3223  */
3224 static int lnet_peer_deletion(struct lnet_peer *lp)
3225 __must_hold(&lp->lp_lock)
3226 {
3227         struct list_head rlist;
3228         struct lnet_route *route, *tmp;
3229         int sensitivity = lp->lp_health_sensitivity;
3230         int rc;
3231
3232         INIT_LIST_HEAD(&rlist);
3233
3234         lp->lp_state &= ~(LNET_PEER_DISCOVERING | LNET_PEER_FORCE_PING |
3235                           LNET_PEER_FORCE_PUSH);
3236         CDEBUG(D_NET, "peer %s(%p) state %#x\n",
3237                libcfs_nidstr(&lp->lp_primary_nid), lp, lp->lp_state);
3238
3239         /* no-op if lnet_peer_del() has already been called on this peer */
3240         if (lp->lp_state & LNET_PEER_MARK_DELETED)
3241                 return 0;
3242
3243         if (the_lnet.ln_dc_state != LNET_DC_STATE_RUNNING)
3244                 return -ESHUTDOWN;
3245
3246         spin_unlock(&lp->lp_lock);
3247
3248         mutex_lock(&the_lnet.ln_api_mutex);
3249
3250         lnet_net_lock(LNET_LOCK_EX);
3251         /* remove the peer from the discovery work
3252          * queue if it's on there in preparation
3253          * of deleting it.
3254          */
3255         if (!list_empty(&lp->lp_dc_list))
3256                 list_del_init(&lp->lp_dc_list);
3257         list_for_each_entry_safe(route, tmp,
3258                                  &lp->lp_routes,
3259                                  lr_gwlist)
3260                 lnet_move_route(route, NULL, &rlist);
3261         lnet_net_unlock(LNET_LOCK_EX);
3262
3263         /* lnet_peer_del() deletes all the peer NIs owned by this peer */
3264         rc = lnet_peer_del(lp);
3265         if (rc)
3266                 CNETERR("Internal error: Unable to delete peer %s rc %d\n",
3267                         libcfs_nidstr(&lp->lp_primary_nid), rc);
3268
3269         list_for_each_entry_safe(route, tmp,
3270                                  &rlist, lr_list) {
3271                 /* re-add these routes */
3272                 lnet_add_route(route->lr_net,
3273                                route->lr_hops,
3274                                &route->lr_nid,
3275                                route->lr_priority,
3276                                sensitivity);
3277                 LIBCFS_FREE(route, sizeof(*route));
3278         }
3279
3280         mutex_unlock(&the_lnet.ln_api_mutex);
3281
3282         spin_lock(&lp->lp_lock);
3283
3284         return 0;
3285 }
3286
3287 /*
3288  * Update a peer using the data received.
3289  */
3290 static int lnet_peer_data_present(struct lnet_peer *lp)
3291 __must_hold(&lp->lp_lock)
3292 {
3293         struct lnet_ping_buffer *pbuf;
3294         struct lnet_peer_ni *lpni;
3295         lnet_nid_t nid = LNET_NID_ANY;
3296         unsigned flags;
3297         int rc = 0;
3298
3299         pbuf = lp->lp_data;
3300         lp->lp_data = NULL;
3301         lp->lp_state &= ~LNET_PEER_DATA_PRESENT;
3302         lp->lp_state |= LNET_PEER_NIDS_UPTODATE;
3303         spin_unlock(&lp->lp_lock);
3304
3305         /*
3306          * Modifications of peer structures are done while holding the
3307          * ln_api_mutex. A global lock is required because we may be
3308          * modifying multiple peer structures, and a mutex greatly
3309          * simplifies memory management.
3310          *
3311          * The actual changes to the data structures must also protect
3312          * against concurrent lookups, for which the lnet_net_lock in
3313          * LNET_LOCK_EX mode is used.
3314          */
3315         mutex_lock(&the_lnet.ln_api_mutex);
3316         if (the_lnet.ln_state != LNET_STATE_RUNNING) {
3317                 rc = -ESHUTDOWN;
3318                 goto out;
3319         }
3320
3321         /*
3322          * If this peer is not on the peer list then it is being torn
3323          * down, and our reference count may be all that is keeping it
3324          * alive. Don't do any work on it.
3325          */
3326         if (list_empty(&lp->lp_peer_list))
3327                 goto out;
3328
3329         flags = LNET_PEER_DISCOVERED;
3330         if (pbuf->pb_info.pi_features & LNET_PING_FEAT_MULTI_RAIL)
3331                 flags |= LNET_PEER_MULTI_RAIL;
3332
3333         /*
3334          * Check whether the primary NID in the message matches the
3335          * primary NID of the peer. If it does, update the peer, if
3336          * it it does not, check whether there is already a peer with
3337          * that primary NID. If no such peer exists, try to update
3338          * the primary NID of the current peer (allowed if it was
3339          * created due to message traffic) and complete the update.
3340          * If the peer did exist, hand off the data to it.
3341          *
3342          * The peer for the loopback interface is a special case: this
3343          * is the peer for the local node, and we want to set its
3344          * primary NID to the correct value here. Moreover, this peer
3345          * can show up with only the loopback NID in the ping buffer.
3346          */
3347         if (pbuf->pb_info.pi_nnis <= 1)
3348                 goto out;
3349         nid = pbuf->pb_info.pi_ni[1].ns_nid;
3350         if (nid_is_lo0(&lp->lp_primary_nid)) {
3351                 rc = lnet_peer_set_primary_nid(lp, nid, flags);
3352                 if (!rc)
3353                         rc = lnet_peer_merge_data(lp, pbuf);
3354         /*
3355          * if the primary nid of the peer is present in the ping info returned
3356          * from the peer, but it's not the local primary peer we have
3357          * cached and discovery is disabled, then we don't want to update
3358          * our local peer info, by adding or removing NIDs, we just want
3359          * to update the status of the nids that we currently have
3360          * recorded in that peer.
3361          */
3362         } else if (lnet_nid_to_nid4(&lp->lp_primary_nid) == nid ||
3363                    (lnet_is_nid_in_ping_info(lnet_nid_to_nid4(&lp->lp_primary_nid),
3364                                              &pbuf->pb_info) &&
3365                     lnet_is_discovery_disabled(lp))) {
3366                 rc = lnet_peer_merge_data(lp, pbuf);
3367         } else {
3368                 lpni = lnet_find_peer_ni_locked(nid);
3369                 if (!lpni || lp == lpni->lpni_peer_net->lpn_peer) {
3370                         rc = lnet_peer_set_primary_nid(lp, nid, flags);
3371                         if (rc) {
3372                                 CERROR("Primary NID error %s versus %s: %d\n",
3373                                        libcfs_nidstr(&lp->lp_primary_nid),
3374                                        libcfs_nid2str(nid), rc);
3375                         } else {
3376                                 rc = lnet_peer_merge_data(lp, pbuf);
3377                         }
3378                         if (lpni)
3379                                 lnet_peer_ni_decref_locked(lpni);
3380                 } else {
3381                         struct lnet_peer *new_lp;
3382                         new_lp = lpni->lpni_peer_net->lpn_peer;
3383                         /*
3384                          * if lp has discovery/MR enabled that means new_lp
3385                          * should have discovery/MR enabled as well, since
3386                          * it's the same peer, which we're about to merge
3387                          */
3388                         spin_lock(&lp->lp_lock);
3389                         spin_lock(&new_lp->lp_lock);
3390                         if (!(lp->lp_state & LNET_PEER_NO_DISCOVERY))
3391                                 new_lp->lp_state &= ~LNET_PEER_NO_DISCOVERY;
3392                         if (lp->lp_state & LNET_PEER_MULTI_RAIL)
3393                                 new_lp->lp_state |= LNET_PEER_MULTI_RAIL;
3394                         /* If we're processing a ping reply then we may be
3395                          * about to send a push to the peer that we ping'd.
3396                          * Since the ping reply that we're processing was
3397                          * received by lp, we need to set the discovery source
3398                          * NID for new_lp to the NID stored in lp.
3399                          */
3400                         if (!LNET_NID_IS_ANY(&lp->lp_disc_src_nid)) {
3401                                 new_lp->lp_disc_src_nid = lp->lp_disc_src_nid;
3402                                 new_lp->lp_disc_dst_nid = lp->lp_disc_dst_nid;
3403                         }
3404                         spin_unlock(&new_lp->lp_lock);
3405                         spin_unlock(&lp->lp_lock);
3406
3407                         rc = lnet_peer_set_primary_data(new_lp, pbuf);
3408                         lnet_consolidate_routes_locked(lp, new_lp);
3409                         lnet_peer_ni_decref_locked(lpni);
3410                 }
3411         }
3412 out:
3413         CDEBUG(D_NET, "peer %s(%p): %d. state = 0x%x\n",
3414                libcfs_nidstr(&lp->lp_primary_nid), lp, rc,
3415                lp->lp_state);
3416         mutex_unlock(&the_lnet.ln_api_mutex);
3417
3418         spin_lock(&lp->lp_lock);
3419         /* Tell discovery to re-check the peer immediately. */
3420         if (!rc)
3421                 rc = LNET_REDISCOVER_PEER;
3422         return rc;
3423 }
3424
3425 /*
3426  * A ping failed. Clear the PING_FAILED state and set the
3427  * FORCE_PING state, to ensure a retry even if discovery is
3428  * disabled. This avoids being left with incorrect state.
3429  */
3430 static int lnet_peer_ping_failed(struct lnet_peer *lp)
3431 __must_hold(&lp->lp_lock)
3432 {
3433         struct lnet_handle_md mdh;
3434         int rc;
3435
3436         mdh = lp->lp_ping_mdh;
3437         LNetInvalidateMDHandle(&lp->lp_ping_mdh);
3438         lp->lp_state &= ~LNET_PEER_PING_FAILED;
3439         lp->lp_state |= LNET_PEER_FORCE_PING;
3440         rc = lp->lp_ping_error;
3441         lp->lp_ping_error = 0;
3442         spin_unlock(&lp->lp_lock);
3443
3444         if (!LNetMDHandleIsInvalid(mdh))
3445                 LNetMDUnlink(mdh);
3446
3447         CDEBUG(D_NET, "peer %s:%d\n",
3448                libcfs_nidstr(&lp->lp_primary_nid), rc);
3449
3450         spin_lock(&lp->lp_lock);
3451         return rc ? rc : LNET_REDISCOVER_PEER;
3452 }
3453
3454 /* Active side of ping. */
3455 static int lnet_peer_send_ping(struct lnet_peer *lp)
3456 __must_hold(&lp->lp_lock)
3457 {
3458         int nnis;
3459         int rc;
3460         int cpt;
3461
3462         lp->lp_state |= LNET_PEER_PING_SENT;
3463         lp->lp_state &= ~LNET_PEER_FORCE_PING;
3464         spin_unlock(&lp->lp_lock);
3465
3466         cpt = lnet_net_lock_current();
3467         /* Refcount for MD. */
3468         lnet_peer_addref_locked(lp);
3469         lnet_net_unlock(cpt);
3470
3471         nnis = max(lp->lp_data_nnis, LNET_INTERFACES_MIN);
3472
3473         rc = lnet_send_ping(lnet_nid_to_nid4(&lp->lp_primary_nid),
3474                             &lp->lp_ping_mdh, nnis, lp,
3475                             the_lnet.ln_dc_handler, false);
3476
3477         /*
3478          * if LNetMDBind in lnet_send_ping fails we need to decrement the
3479          * refcount on the peer, otherwise LNetMDUnlink will be called
3480          * which will eventually do that.
3481          */
3482         if (rc > 0) {
3483                 lnet_net_lock(cpt);
3484                 lnet_peer_decref_locked(lp);
3485                 lnet_net_unlock(cpt);
3486                 rc = -rc; /* change the rc to negative value */
3487                 goto fail_error;
3488         } else if (rc < 0) {
3489                 goto fail_error;
3490         }
3491
3492         CDEBUG(D_NET, "peer %s\n", libcfs_nidstr(&lp->lp_primary_nid));
3493
3494         spin_lock(&lp->lp_lock);
3495         return 0;
3496
3497 fail_error:
3498         CDEBUG(D_NET, "peer %s: %d\n", libcfs_nidstr(&lp->lp_primary_nid), rc);
3499         /*
3500          * The errors that get us here are considered hard errors and
3501          * cause Discovery to terminate. So we clear PING_SENT, but do
3502          * not set either PING_FAILED or FORCE_PING. In fact we need
3503          * to clear PING_FAILED, because the unlink event handler will
3504          * have set it if we called LNetMDUnlink() above.
3505          */
3506         spin_lock(&lp->lp_lock);
3507         lp->lp_state &= ~(LNET_PEER_PING_SENT | LNET_PEER_PING_FAILED);
3508         return rc;
3509 }
3510
3511 /*
3512  * This function exists because you cannot call LNetMDUnlink() from an
3513  * event handler.
3514  */
3515 static int lnet_peer_push_failed(struct lnet_peer *lp)
3516 __must_hold(&lp->lp_lock)
3517 {
3518         struct lnet_handle_md mdh;
3519         int rc;
3520
3521         mdh = lp->lp_push_mdh;
3522         LNetInvalidateMDHandle(&lp->lp_push_mdh);
3523         lp->lp_state &= ~LNET_PEER_PUSH_FAILED;
3524         rc = lp->lp_push_error;
3525         lp->lp_push_error = 0;
3526         spin_unlock(&lp->lp_lock);
3527
3528         if (!LNetMDHandleIsInvalid(mdh))
3529                 LNetMDUnlink(mdh);
3530
3531         CDEBUG(D_NET, "peer %s\n", libcfs_nidstr(&lp->lp_primary_nid));
3532         spin_lock(&lp->lp_lock);
3533         return rc ? rc : LNET_REDISCOVER_PEER;
3534 }
3535
3536 /*
3537  * Mark the peer as discovered.
3538  */
3539 static int lnet_peer_discovered(struct lnet_peer *lp)
3540 __must_hold(&lp->lp_lock)
3541 {
3542         lp->lp_state |= LNET_PEER_DISCOVERED;
3543         lp->lp_state &= ~(LNET_PEER_DISCOVERING |
3544                           LNET_PEER_REDISCOVER);
3545
3546         lp->lp_dc_error = 0;
3547
3548         CDEBUG(D_NET, "peer %s\n", libcfs_nidstr(&lp->lp_primary_nid));
3549
3550         return 0;
3551 }
3552
3553 /* Active side of push. */
3554 static int lnet_peer_send_push(struct lnet_peer *lp)
3555 __must_hold(&lp->lp_lock)
3556 {
3557         struct lnet_ping_buffer *pbuf;
3558         struct lnet_process_id id;
3559         struct lnet_md md;
3560         int cpt;
3561         int rc;
3562
3563         /* Don't push to a non-multi-rail peer. */
3564         if (!(lp->lp_state & LNET_PEER_MULTI_RAIL)) {
3565                 lp->lp_state &= ~LNET_PEER_FORCE_PUSH;
3566                 /* if peer's NIDs are uptodate then peer is discovered */
3567                 if (lp->lp_state & LNET_PEER_NIDS_UPTODATE) {
3568                         rc = lnet_peer_discovered(lp);
3569                         return rc;
3570                 }
3571
3572                 return 0;
3573         }
3574
3575         lp->lp_state |= LNET_PEER_PUSH_SENT;
3576         lp->lp_state &= ~LNET_PEER_FORCE_PUSH;
3577         spin_unlock(&lp->lp_lock);
3578
3579         cpt = lnet_net_lock_current();
3580         pbuf = the_lnet.ln_ping_target;
3581         lnet_ping_buffer_addref(pbuf);
3582         lnet_net_unlock(cpt);
3583
3584         /* Push source MD */
3585         md.start     = &pbuf->pb_info;
3586         md.length    = LNET_PING_INFO_SIZE(pbuf->pb_nnis);
3587         md.threshold = 2; /* Put/Ack */
3588         md.max_size  = 0;
3589         md.options   = LNET_MD_TRACK_RESPONSE;
3590         md.handler   = the_lnet.ln_dc_handler;
3591         md.user_ptr  = lp;
3592
3593         rc = LNetMDBind(&md, LNET_UNLINK, &lp->lp_push_mdh);
3594         if (rc) {
3595                 lnet_ping_buffer_decref(pbuf);
3596                 CERROR("Can't bind push source MD: %d\n", rc);
3597                 goto fail_error;
3598         }
3599
3600         cpt = lnet_net_lock_current();
3601         /* Refcount for MD. */
3602         lnet_peer_addref_locked(lp);
3603         id.pid = LNET_PID_LUSTRE;
3604         if (!LNET_NID_IS_ANY(&lp->lp_disc_dst_nid))
3605                 id.nid = lnet_nid_to_nid4(&lp->lp_disc_dst_nid);
3606         else
3607                 id.nid = lnet_nid_to_nid4(&lp->lp_primary_nid);
3608         lnet_net_unlock(cpt);
3609
3610         rc = LNetPut(lnet_nid_to_nid4(&lp->lp_disc_src_nid), lp->lp_push_mdh,
3611                      LNET_ACK_REQ, id, LNET_RESERVED_PORTAL,
3612                      LNET_PROTO_PING_MATCHBITS, 0, 0);
3613
3614         /*
3615          * reset the discovery nid. There is no need to restrict sending
3616          * from that source, if we call lnet_push_update_to_peers(). It'll
3617          * get set to a specific NID, if we initiate discovery from the
3618          * scratch
3619          */
3620         lp->lp_disc_src_nid = LNET_ANY_NID;
3621         lp->lp_disc_dst_nid = LNET_ANY_NID;
3622
3623         if (rc)
3624                 goto fail_unlink;
3625
3626         CDEBUG(D_NET, "peer %s\n", libcfs_nidstr(&lp->lp_primary_nid));
3627
3628         spin_lock(&lp->lp_lock);
3629         return 0;
3630
3631 fail_unlink:
3632         LNetMDUnlink(lp->lp_push_mdh);
3633         LNetInvalidateMDHandle(&lp->lp_push_mdh);
3634 fail_error:
3635         CDEBUG(D_NET, "peer %s(%p): %d\n", libcfs_nidstr(&lp->lp_primary_nid),
3636                lp, rc);
3637         /*
3638          * The errors that get us here are considered hard errors and
3639          * cause Discovery to terminate. So we clear PUSH_SENT, but do
3640          * not set PUSH_FAILED. In fact we need to clear PUSH_FAILED,
3641          * because the unlink event handler will have set it if we
3642          * called LNetMDUnlink() above.
3643          */
3644         spin_lock(&lp->lp_lock);
3645         lp->lp_state &= ~(LNET_PEER_PUSH_SENT | LNET_PEER_PUSH_FAILED);
3646         return rc;
3647 }
3648
3649 /*
3650  * An unrecoverable error was encountered during discovery.
3651  * Set error status in peer and abort discovery.
3652  */
3653 static void lnet_peer_discovery_error(struct lnet_peer *lp, int error)
3654 {
3655         CDEBUG(D_NET, "Discovery error %s: %d\n",
3656                libcfs_nidstr(&lp->lp_primary_nid), error);
3657
3658         spin_lock(&lp->lp_lock);
3659         lp->lp_dc_error = error;
3660         lp->lp_state &= ~LNET_PEER_DISCOVERING;
3661         lp->lp_state |= LNET_PEER_REDISCOVER;
3662         spin_unlock(&lp->lp_lock);
3663 }
3664
3665 /*
3666  * Wait for work to be queued or some other change that must be
3667  * attended to. Returns non-zero if the discovery thread should shut
3668  * down.
3669  */
3670 static int lnet_peer_discovery_wait_for_work(void)
3671 {
3672         int cpt;
3673         int rc = 0;
3674
3675         DEFINE_WAIT(wait);
3676
3677         cpt = lnet_net_lock_current();
3678         for (;;) {
3679                 prepare_to_wait(&the_lnet.ln_dc_waitq, &wait,
3680                                 TASK_INTERRUPTIBLE);
3681                 if (the_lnet.ln_dc_state == LNET_DC_STATE_STOPPING)
3682                         break;
3683                 if (lnet_push_target_resize_needed() ||
3684                     the_lnet.ln_push_target->pb_needs_post)
3685                         break;
3686                 if (!list_empty(&the_lnet.ln_dc_request))
3687                         break;
3688                 if (!list_empty(&the_lnet.ln_msg_resend))
3689                         break;
3690                 lnet_net_unlock(cpt);
3691
3692                 /*
3693                  * wakeup max every second to check if there are peers that
3694                  * have been stuck on the working queue for greater than
3695                  * the peer timeout.
3696                  */
3697                 schedule_timeout(cfs_time_seconds(1));
3698                 finish_wait(&the_lnet.ln_dc_waitq, &wait);
3699                 cpt = lnet_net_lock_current();
3700         }
3701         finish_wait(&the_lnet.ln_dc_waitq, &wait);
3702
3703         if (the_lnet.ln_dc_state == LNET_DC_STATE_STOPPING)
3704                 rc = -ESHUTDOWN;
3705
3706         lnet_net_unlock(cpt);
3707
3708         CDEBUG(D_NET, "woken: %d\n", rc);
3709
3710         return rc;
3711 }
3712
3713 /*
3714  * Messages that were pending on a destroyed peer will be put on a global
3715  * resend list. The message resend list will be checked by
3716  * the discovery thread when it wakes up, and will resend messages. These
3717  * messages can still be sendable in the case the lpni which was the initial
3718  * cause of the message re-queue was transfered to another peer.
3719  *
3720  * It is possible that LNet could be shutdown while we're iterating
3721  * through the list. lnet_shudown_lndnets() will attempt to access the
3722  * resend list, but will have to wait until the spinlock is released, by
3723  * which time there shouldn't be any more messages on the resend list.
3724  * During shutdown lnet_send() will fail and lnet_finalize() will be called
3725  * for the messages so they can be released. The other case is that
3726  * lnet_shudown_lndnets() can finalize all the messages before this
3727  * function can visit the resend list, in which case this function will be
3728  * a no-op.
3729  */
3730 static void lnet_resend_msgs(void)
3731 {
3732         struct lnet_msg *msg, *tmp;
3733         LIST_HEAD(resend);
3734         int rc;
3735
3736         spin_lock(&the_lnet.ln_msg_resend_lock);
3737         list_splice(&the_lnet.ln_msg_resend, &resend);
3738         spin_unlock(&the_lnet.ln_msg_resend_lock);
3739
3740         list_for_each_entry_safe(msg, tmp, &resend, msg_list) {
3741                 list_del_init(&msg->msg_list);
3742                 rc = lnet_send(msg->msg_src_nid_param, msg,
3743                                msg->msg_rtr_nid_param);
3744                 if (rc < 0) {
3745                         CNETERR("Error sending %s to %s: %d\n",
3746                                lnet_msgtyp2str(msg->msg_type),
3747                                libcfs_id2str(msg->msg_target), rc);
3748                         lnet_finalize(msg, rc);
3749                 }
3750         }
3751 }
3752
3753 /* The discovery thread. */
3754 static int lnet_peer_discovery(void *arg)
3755 {
3756         struct lnet_peer *lp;
3757         int rc;
3758
3759         wait_for_completion(&the_lnet.ln_started);
3760
3761         CDEBUG(D_NET, "started\n");
3762
3763         for (;;) {
3764                 if (lnet_peer_discovery_wait_for_work())
3765                         break;
3766
3767                 if (lnet_push_target_resize_needed())
3768                         lnet_push_target_resize();
3769                 else if (the_lnet.ln_push_target->pb_needs_post)
3770                         lnet_push_target_post(the_lnet.ln_push_target,
3771                                               &the_lnet.ln_push_target_md);
3772
3773                 lnet_resend_msgs();
3774
3775                 lnet_net_lock(LNET_LOCK_EX);
3776                 if (the_lnet.ln_dc_state == LNET_DC_STATE_STOPPING) {
3777                         lnet_net_unlock(LNET_LOCK_EX);
3778                         break;
3779                 }
3780
3781                 /*
3782                  * Process all incoming discovery work requests.  When
3783                  * discovery must wait on a peer to change state, it
3784                  * is added to the tail of the ln_dc_working queue. A
3785                  * timestamp keeps track of when the peer was added,
3786                  * so we can time out discovery requests that take too
3787                  * long.
3788                  */
3789                 while (!list_empty(&the_lnet.ln_dc_request)) {
3790                         lp = list_first_entry(&the_lnet.ln_dc_request,
3791                                               struct lnet_peer, lp_dc_list);
3792                         list_move(&lp->lp_dc_list, &the_lnet.ln_dc_working);
3793                         /*
3794                          * set the time the peer was put on the dc_working
3795                          * queue. It shouldn't remain on the queue
3796                          * forever, in case the GET message (for ping)
3797                          * doesn't get a REPLY or the PUT message (for
3798                          * push) doesn't get an ACK.
3799                          */
3800                         lp->lp_last_queued = ktime_get_real_seconds();
3801                         lnet_net_unlock(LNET_LOCK_EX);
3802
3803                         if (lnet_push_target_resize_needed())
3804                                 lnet_push_target_resize();
3805                         else if (the_lnet.ln_push_target->pb_needs_post)
3806                                 lnet_push_target_post(the_lnet.ln_push_target,
3807                                                       &the_lnet.ln_push_target_md);
3808
3809                         /*
3810                          * Select an action depending on the state of
3811                          * the peer and whether discovery is disabled.
3812                          * The check whether discovery is disabled is
3813                          * done after the code that handles processing
3814                          * for arrived data, cleanup for failures, and
3815                          * forcing a Ping or Push.
3816                          */
3817                         spin_lock(&lp->lp_lock);
3818                         CDEBUG(D_NET, "peer %s(%p) state %#x\n",
3819                                 libcfs_nidstr(&lp->lp_primary_nid), lp,
3820                                 lp->lp_state);
3821                         if (lp->lp_state & (LNET_PEER_MARK_DELETION |
3822                                             LNET_PEER_MARK_DELETED))
3823                                 rc = lnet_peer_deletion(lp);
3824                         else if (lp->lp_state & LNET_PEER_DATA_PRESENT)
3825                                 rc = lnet_peer_data_present(lp);
3826                         else if (lp->lp_state & LNET_PEER_PING_FAILED)
3827                                 rc = lnet_peer_ping_failed(lp);
3828                         else if (lp->lp_state & LNET_PEER_PUSH_FAILED)
3829                                 rc = lnet_peer_push_failed(lp);
3830                         else if (lp->lp_state & LNET_PEER_FORCE_PING)
3831                                 rc = lnet_peer_send_ping(lp);
3832                         else if (lp->lp_state & LNET_PEER_FORCE_PUSH)
3833                                 rc = lnet_peer_send_push(lp);
3834                         else if (!(lp->lp_state & LNET_PEER_NIDS_UPTODATE))
3835                                 rc = lnet_peer_send_ping(lp);
3836                         else if (lnet_peer_needs_push(lp))
3837                                 rc = lnet_peer_send_push(lp);
3838                         else
3839                                 rc = lnet_peer_discovered(lp);
3840                         CDEBUG(D_NET, "peer %s(%p) state %#x rc %d\n",
3841                                 libcfs_nidstr(&lp->lp_primary_nid), lp,
3842                                 lp->lp_state, rc);
3843                         spin_unlock(&lp->lp_lock);
3844
3845                         lnet_net_lock(LNET_LOCK_EX);
3846                         if (rc == LNET_REDISCOVER_PEER) {
3847                                 list_move(&lp->lp_dc_list,
3848                                           &the_lnet.ln_dc_request);
3849                         } else if (rc) {
3850                                 lnet_peer_discovery_error(lp, rc);
3851                         }
3852                         if (!(lp->lp_state & LNET_PEER_DISCOVERING))
3853                                 lnet_peer_discovery_complete(lp);
3854                         if (the_lnet.ln_dc_state == LNET_DC_STATE_STOPPING)
3855                                 break;
3856
3857                 }
3858
3859                 lnet_net_unlock(LNET_LOCK_EX);
3860         }
3861
3862         CDEBUG(D_NET, "stopping\n");
3863         /*
3864          * Clean up before telling lnet_peer_discovery_stop() that
3865          * we're done. Use wake_up() below to somewhat reduce the
3866          * size of the thundering herd if there are multiple threads
3867          * waiting on discovery of a single peer.
3868          */
3869
3870         /* Queue cleanup 1: stop all pending pings and pushes. */
3871         lnet_net_lock(LNET_LOCK_EX);
3872         while (!list_empty(&the_lnet.ln_dc_working)) {
3873                 lp = list_first_entry(&the_lnet.ln_dc_working,
3874                                       struct lnet_peer, lp_dc_list);
3875                 list_move(&lp->lp_dc_list, &the_lnet.ln_dc_expired);
3876                 lnet_net_unlock(LNET_LOCK_EX);
3877                 lnet_peer_cancel_discovery(lp);
3878                 lnet_net_lock(LNET_LOCK_EX);
3879         }
3880         lnet_net_unlock(LNET_LOCK_EX);
3881
3882         /* Queue cleanup 2: wait for the expired queue to clear. */
3883         while (!list_empty(&the_lnet.ln_dc_expired))
3884                 schedule_timeout_uninterruptible(cfs_time_seconds(1));
3885
3886         /* Queue cleanup 3: clear the request queue. */
3887         lnet_net_lock(LNET_LOCK_EX);
3888         while (!list_empty(&the_lnet.ln_dc_request)) {
3889                 lp = list_first_entry(&the_lnet.ln_dc_request,
3890                                       struct lnet_peer, lp_dc_list);
3891                 lnet_peer_discovery_error(lp, -ESHUTDOWN);
3892                 lnet_peer_discovery_complete(lp);
3893         }
3894         lnet_net_unlock(LNET_LOCK_EX);
3895
3896         lnet_assert_handler_unused(the_lnet.ln_dc_handler);
3897         the_lnet.ln_dc_handler = NULL;
3898
3899         the_lnet.ln_dc_state = LNET_DC_STATE_SHUTDOWN;
3900         wake_up(&the_lnet.ln_dc_waitq);
3901
3902         CDEBUG(D_NET, "stopped\n");
3903
3904         return 0;
3905 }
3906
3907 /* ln_api_mutex is held on entry. */
3908 int lnet_peer_discovery_start(void)
3909 {
3910         struct task_struct *task;
3911         int rc = 0;
3912
3913         if (the_lnet.ln_dc_state != LNET_DC_STATE_SHUTDOWN)
3914                 return -EALREADY;
3915
3916         the_lnet.ln_dc_handler = lnet_discovery_event_handler;
3917         the_lnet.ln_dc_state = LNET_DC_STATE_RUNNING;
3918         task = kthread_run(lnet_peer_discovery, NULL, "lnet_discovery");
3919         if (IS_ERR(task)) {
3920                 rc = PTR_ERR(task);
3921                 CERROR("Can't start peer discovery thread: %d\n", rc);
3922
3923                 the_lnet.ln_dc_handler = NULL;
3924
3925                 the_lnet.ln_dc_state = LNET_DC_STATE_SHUTDOWN;
3926         }
3927
3928         CDEBUG(D_NET, "discovery start: %d\n", rc);
3929
3930         return rc;
3931 }
3932
3933 /* ln_api_mutex is held on entry. */
3934 void lnet_peer_discovery_stop(void)
3935 {
3936         if (the_lnet.ln_dc_state == LNET_DC_STATE_SHUTDOWN)
3937                 return;
3938
3939         LASSERT(the_lnet.ln_dc_state == LNET_DC_STATE_RUNNING);
3940         the_lnet.ln_dc_state = LNET_DC_STATE_STOPPING;
3941
3942         /* In the LNetNIInit() path we may be stopping discovery before it
3943          * entered its work loop
3944          */
3945         if (!completion_done(&the_lnet.ln_started))
3946                 complete(&the_lnet.ln_started);
3947         else
3948                 wake_up(&the_lnet.ln_dc_waitq);
3949
3950         wait_event(the_lnet.ln_dc_waitq,
3951                    the_lnet.ln_dc_state == LNET_DC_STATE_SHUTDOWN);
3952
3953         LASSERT(list_empty(&the_lnet.ln_dc_request));
3954         LASSERT(list_empty(&the_lnet.ln_dc_working));
3955         LASSERT(list_empty(&the_lnet.ln_dc_expired));
3956
3957         CDEBUG(D_NET, "discovery stopped\n");
3958 }
3959
3960 /* Debugging */
3961
3962 void
3963 lnet_debug_peer(lnet_nid_t nid)
3964 {
3965         char                    *aliveness = "NA";
3966         struct lnet_peer_ni     *lp;
3967         int                     cpt;
3968
3969         cpt = lnet_cpt_of_nid(nid, NULL);
3970         lnet_net_lock(cpt);
3971
3972         lp = lnet_nid2peerni_locked(nid, LNET_NID_ANY, cpt);
3973         if (IS_ERR(lp)) {
3974                 lnet_net_unlock(cpt);
3975                 CDEBUG(D_WARNING, "No peer %s\n", libcfs_nid2str(nid));
3976                 return;
3977         }
3978
3979         if (lnet_isrouter(lp) || lnet_peer_aliveness_enabled(lp))
3980                 aliveness = (lnet_is_peer_ni_alive(lp)) ? "up" : "down";
3981
3982         CDEBUG(D_WARNING, "%-24s %4d %5s %5d %5d %5d %5d %5d %ld\n",
3983                libcfs_nidstr(&lp->lpni_nid), kref_read(&lp->lpni_kref),
3984                aliveness, lp->lpni_net->net_tunables.lct_peer_tx_credits,
3985                lp->lpni_rtrcredits, lp->lpni_minrtrcredits,
3986                lp->lpni_txcredits, lp->lpni_mintxcredits, lp->lpni_txqnob);
3987
3988         lnet_peer_ni_decref_locked(lp);
3989
3990         lnet_net_unlock(cpt);
3991 }
3992
3993 /* Gathering information for userspace. */
3994
3995 int lnet_get_peer_ni_info(__u32 peer_index, __u64 *nid,
3996                           char aliveness[LNET_MAX_STR_LEN],
3997                           __u32 *cpt_iter, __u32 *refcount,
3998                           __u32 *ni_peer_tx_credits, __u32 *peer_tx_credits,
3999                           __u32 *peer_rtr_credits, __u32 *peer_min_rtr_credits,
4000                           __u32 *peer_tx_qnob)
4001 {
4002         struct lnet_peer_table          *peer_table;
4003         struct lnet_peer_ni             *lp;
4004         int                             j;
4005         int                             lncpt;
4006         bool                            found = false;
4007
4008         /* get the number of CPTs */
4009         lncpt = cfs_percpt_number(the_lnet.ln_peer_tables);
4010
4011         /* if the cpt number to be examined is >= the number of cpts in
4012          * the system then indicate that there are no more cpts to examin
4013          */
4014         if (*cpt_iter >= lncpt)
4015                 return -ENOENT;
4016
4017         /* get the current table */
4018         peer_table = the_lnet.ln_peer_tables[*cpt_iter];
4019         /* if the ptable is NULL then there are no more cpts to examine */
4020         if (peer_table == NULL)
4021                 return -ENOENT;
4022
4023         lnet_net_lock(*cpt_iter);
4024
4025         for (j = 0; j < LNET_PEER_HASH_SIZE && !found; j++) {
4026                 struct list_head *peers = &peer_table->pt_hash[j];
4027
4028                 list_for_each_entry(lp, peers, lpni_hashlist) {
4029                         if (!nid_is_nid4(&lp->lpni_nid))
4030                                 continue;
4031                         if (peer_index-- > 0)
4032                                 continue;
4033
4034                         snprintf(aliveness, LNET_MAX_STR_LEN, "NA");
4035                         if (lnet_isrouter(lp) ||
4036                                 lnet_peer_aliveness_enabled(lp))
4037                                 snprintf(aliveness, LNET_MAX_STR_LEN,
4038                                          lnet_is_peer_ni_alive(lp) ? "up" : "down");
4039
4040                         *nid = lnet_nid_to_nid4(&lp->lpni_nid);
4041                         *refcount = kref_read(&lp->lpni_kref);
4042                         *ni_peer_tx_credits =
4043                                 lp->lpni_net->net_tunables.lct_peer_tx_credits;
4044                         *peer_tx_credits = lp->lpni_txcredits;
4045                         *peer_rtr_credits = lp->lpni_rtrcredits;
4046                         *peer_min_rtr_credits = lp->lpni_mintxcredits;
4047                         *peer_tx_qnob = lp->lpni_txqnob;
4048
4049                         found = true;
4050                 }
4051
4052         }
4053         lnet_net_unlock(*cpt_iter);
4054
4055         *cpt_iter = lncpt;
4056
4057         return found ? 0 : -ENOENT;
4058 }
4059
4060 /* ln_api_mutex is held, which keeps the peer list stable */
4061 int lnet_get_peer_info(struct lnet_ioctl_peer_cfg *cfg, void __user *bulk)
4062 {
4063         struct lnet_ioctl_element_stats *lpni_stats;
4064         struct lnet_ioctl_element_msg_stats *lpni_msg_stats;
4065         struct lnet_ioctl_peer_ni_hstats *lpni_hstats;
4066         struct lnet_peer_ni_credit_info *lpni_info;
4067         struct lnet_peer_ni *lpni;
4068         struct lnet_peer *lp;
4069         lnet_nid_t nid;
4070         __u32 size;
4071         int rc;
4072
4073         lp = lnet_find_peer(cfg->prcfg_prim_nid);
4074
4075         if (!lp) {
4076                 rc = -ENOENT;
4077                 goto out;
4078         }
4079
4080         size = sizeof(nid) + sizeof(*lpni_info) + sizeof(*lpni_stats)
4081                 + sizeof(*lpni_msg_stats) + sizeof(*lpni_hstats);
4082         size *= lp->lp_nnis;
4083         if (size > cfg->prcfg_size) {
4084                 cfg->prcfg_size = size;
4085                 rc = -E2BIG;
4086                 goto out_lp_decref;
4087         }
4088
4089         cfg->prcfg_prim_nid = lnet_nid_to_nid4(&lp->lp_primary_nid);
4090         cfg->prcfg_mr = lnet_peer_is_multi_rail(lp);
4091         cfg->prcfg_cfg_nid = lnet_nid_to_nid4(&lp->lp_primary_nid);
4092         cfg->prcfg_count = lp->lp_nnis;
4093         cfg->prcfg_size = size;
4094         cfg->prcfg_state = lp->lp_state;
4095
4096         /* Allocate helper buffers. */
4097         rc = -ENOMEM;
4098         LIBCFS_ALLOC(lpni_info, sizeof(*lpni_info));
4099         if (!lpni_info)
4100                 goto out_lp_decref;
4101         LIBCFS_ALLOC(lpni_stats, sizeof(*lpni_stats));
4102         if (!lpni_stats)
4103                 goto out_free_info;
4104         LIBCFS_ALLOC(lpni_msg_stats, sizeof(*lpni_msg_stats));
4105         if (!lpni_msg_stats)
4106                 goto out_free_stats;
4107         LIBCFS_ALLOC(lpni_hstats, sizeof(*lpni_hstats));
4108         if (!lpni_hstats)
4109                 goto out_free_msg_stats;
4110
4111
4112         lpni = NULL;
4113         rc = -EFAULT;
4114         while ((lpni = lnet_get_next_peer_ni_locked(lp, NULL, lpni)) != NULL) {
4115                 if (!nid_is_nid4(&lpni->lpni_nid))
4116                         continue;
4117                 nid = lnet_nid_to_nid4(&lpni->lpni_nid);
4118                 if (copy_to_user(bulk, &nid, sizeof(nid)))
4119                         goto out_free_hstats;
4120                 bulk += sizeof(nid);
4121
4122                 memset(lpni_info, 0, sizeof(*lpni_info));
4123                 snprintf(lpni_info->cr_aliveness, LNET_MAX_STR_LEN, "NA");
4124                 if (lnet_isrouter(lpni) ||
4125                         lnet_peer_aliveness_enabled(lpni))
4126                         snprintf(lpni_info->cr_aliveness, LNET_MAX_STR_LEN,
4127                                 lnet_is_peer_ni_alive(lpni) ? "up" : "down");
4128
4129                 lpni_info->cr_refcount = kref_read(&lpni->lpni_kref);
4130                 lpni_info->cr_ni_peer_tx_credits = (lpni->lpni_net != NULL) ?
4131                         lpni->lpni_net->net_tunables.lct_peer_tx_credits : 0;
4132                 lpni_info->cr_peer_tx_credits = lpni->lpni_txcredits;
4133                 lpni_info->cr_peer_rtr_credits = lpni->lpni_rtrcredits;
4134                 lpni_info->cr_peer_min_rtr_credits = lpni->lpni_minrtrcredits;
4135                 lpni_info->cr_peer_min_tx_credits = lpni->lpni_mintxcredits;
4136                 lpni_info->cr_peer_tx_qnob = lpni->lpni_txqnob;
4137                 if (copy_to_user(bulk, lpni_info, sizeof(*lpni_info)))
4138                         goto out_free_hstats;
4139                 bulk += sizeof(*lpni_info);
4140
4141                 memset(lpni_stats, 0, sizeof(*lpni_stats));
4142                 lpni_stats->iel_send_count = lnet_sum_stats(&lpni->lpni_stats,
4143                                                             LNET_STATS_TYPE_SEND);
4144                 lpni_stats->iel_recv_count = lnet_sum_stats(&lpni->lpni_stats,
4145                                                             LNET_STATS_TYPE_RECV);
4146                 lpni_stats->iel_drop_count = lnet_sum_stats(&lpni->lpni_stats,
4147                                                             LNET_STATS_TYPE_DROP);
4148                 if (copy_to_user(bulk, lpni_stats, sizeof(*lpni_stats)))
4149                         goto out_free_hstats;
4150                 bulk += sizeof(*lpni_stats);
4151                 lnet_usr_translate_stats(lpni_msg_stats, &lpni->lpni_stats);
4152                 if (copy_to_user(bulk, lpni_msg_stats, sizeof(*lpni_msg_stats)))
4153                         goto out_free_hstats;
4154                 bulk += sizeof(*lpni_msg_stats);
4155                 lpni_hstats->hlpni_network_timeout =
4156                   atomic_read(&lpni->lpni_hstats.hlt_network_timeout);
4157                 lpni_hstats->hlpni_remote_dropped =
4158                   atomic_read(&lpni->lpni_hstats.hlt_remote_dropped);
4159                 lpni_hstats->hlpni_remote_timeout =
4160                   atomic_read(&lpni->lpni_hstats.hlt_remote_timeout);
4161                 lpni_hstats->hlpni_remote_error =
4162                   atomic_read(&lpni->lpni_hstats.hlt_remote_error);
4163                 lpni_hstats->hlpni_health_value =
4164                   atomic_read(&lpni->lpni_healthv);
4165                 lpni_hstats->hlpni_ping_count = lpni->lpni_ping_count;
4166                 lpni_hstats->hlpni_next_ping = lpni->lpni_next_ping;
4167                 if (copy_to_user(bulk, lpni_hstats, sizeof(*lpni_hstats)))
4168                         goto out_free_hstats;
4169                 bulk += sizeof(*lpni_hstats);
4170         }
4171         rc = 0;
4172
4173 out_free_hstats:
4174         LIBCFS_FREE(lpni_hstats, sizeof(*lpni_hstats));
4175 out_free_msg_stats:
4176         LIBCFS_FREE(lpni_msg_stats, sizeof(*lpni_msg_stats));
4177 out_free_stats:
4178         LIBCFS_FREE(lpni_stats, sizeof(*lpni_stats));
4179 out_free_info:
4180         LIBCFS_FREE(lpni_info, sizeof(*lpni_info));
4181 out_lp_decref:
4182         lnet_peer_decref_locked(lp);
4183 out:
4184         return rc;
4185 }
4186
4187 /* must hold net_lock/0 */
4188 void
4189 lnet_peer_ni_add_to_recoveryq_locked(struct lnet_peer_ni *lpni,
4190                                      struct list_head *recovery_queue,
4191                                      time64_t now)
4192 {
4193         /* the mt could've shutdown and cleaned up the queues */
4194         if (the_lnet.ln_mt_state != LNET_MT_STATE_RUNNING)
4195                 return;
4196
4197         if (!list_empty(&lpni->lpni_recovery))
4198                 return;
4199
4200         if (atomic_read(&lpni->lpni_healthv) == LNET_MAX_HEALTH_VALUE)
4201                 return;
4202
4203         if (!lpni->lpni_last_alive) {
4204                 CDEBUG(D_NET,
4205                        "lpni %s(%p) not eligible for recovery last alive %lld\n",
4206                        libcfs_nidstr(&lpni->lpni_nid), lpni,
4207                        lpni->lpni_last_alive);
4208                 return;
4209         }
4210
4211         if (lnet_recovery_limit &&
4212             now > lpni->lpni_last_alive + lnet_recovery_limit) {
4213                 CDEBUG(D_NET, "lpni %s aged out last alive %lld\n",
4214                        libcfs_nidstr(&lpni->lpni_nid),
4215                        lpni->lpni_last_alive);
4216                 /* Reset the ping count so that if this peer NI is added back to
4217                  * the recovery queue we will send the first ping right away.
4218                  */
4219                 lpni->lpni_ping_count = 0;
4220                 return;
4221         }
4222
4223         /* This peer NI is going on the recovery queue, so take a ref on it */
4224         lnet_peer_ni_addref_locked(lpni);
4225
4226         lnet_peer_ni_set_next_ping(lpni, now);
4227
4228         CDEBUG(D_NET, "%s added to recovery queue. ping count: %u next ping: %lld last alive: %lld health: %d\n",
4229                libcfs_nidstr(&lpni->lpni_nid),
4230                lpni->lpni_ping_count,
4231                lpni->lpni_next_ping,
4232                lpni->lpni_last_alive,
4233                atomic_read(&lpni->lpni_healthv));
4234
4235         list_add_tail(&lpni->lpni_recovery, recovery_queue);
4236 }
4237
4238 /* Call with the ln_api_mutex held */
4239 void
4240 lnet_peer_ni_set_healthv(lnet_nid_t nid, int value, bool all)
4241 {
4242         struct lnet_peer_table *ptable;
4243         struct lnet_peer *lp;
4244         struct lnet_peer_net *lpn;
4245         struct lnet_peer_ni *lpni;
4246         int lncpt;
4247         int cpt;
4248         time64_t now;
4249
4250         if (the_lnet.ln_state != LNET_STATE_RUNNING)
4251                 return;
4252
4253         now = ktime_get_seconds();
4254
4255         if (!all) {
4256                 lnet_net_lock(LNET_LOCK_EX);
4257                 lpni = lnet_find_peer_ni_locked(nid);
4258                 if (!lpni) {
4259                         lnet_net_unlock(LNET_LOCK_EX);
4260                         return;
4261                 }
4262                 lnet_set_lpni_healthv_locked(lpni, value);
4263                 lnet_peer_ni_add_to_recoveryq_locked(lpni,
4264                                              &the_lnet.ln_mt_peerNIRecovq, now);
4265                 lnet_peer_ni_decref_locked(lpni);
4266                 lnet_net_unlock(LNET_LOCK_EX);
4267                 return;
4268         }
4269
4270         lncpt = cfs_percpt_number(the_lnet.ln_peer_tables);
4271
4272         /*
4273          * Walk all the peers and reset the health value for each one to the
4274          * specified value.
4275          */
4276         lnet_net_lock(LNET_LOCK_EX);
4277         for (cpt = 0; cpt < lncpt; cpt++) {
4278                 ptable = the_lnet.ln_peer_tables[cpt];
4279                 list_for_each_entry(lp, &ptable->pt_peer_list, lp_peer_list) {
4280                         list_for_each_entry(lpn, &lp->lp_peer_nets, lpn_peer_nets) {
4281                                 list_for_each_entry(lpni, &lpn->lpn_peer_nis,
4282                                                     lpni_peer_nis) {
4283                                         lnet_set_lpni_healthv_locked(lpni,
4284                                                                      value);
4285                                         lnet_peer_ni_add_to_recoveryq_locked(lpni,
4286                                              &the_lnet.ln_mt_peerNIRecovq, now);
4287                                 }
4288                         }
4289                 }
4290         }
4291         lnet_net_unlock(LNET_LOCK_EX);
4292 }
4293