lnet/lnet/net_fault.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, write to the
  18  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19  * Boston, MA 021110-1307, USA
  20  *
  21  * GPL HEADER END
  22  */
  23 /*
  24  * Copyright (c) 2014, Intel Corporation.
  25  */
  26 /*
  27  * This file is part of Lustre, http://www.lustre.org/
  28  * Lustre is a trademark of Sun Microsystems, Inc.
  29  *
  30  * lnet/lnet/net_fault.c
  31  *
  32  * Lustre network fault simulation
  33  *
  34  * Author: liang.zhen@intel.com
  35  */
  36
  37 #define DEBUG_SUBSYSTEM S_LNET
  38
  39 #include <lnet/lib-lnet.h>
  40 #include <lnet/lnetctl.h>
  41
  42 #define LNET_MSG_MASK           (LNET_PUT_BIT | LNET_ACK_BIT | \
  43                                  LNET_GET_BIT | LNET_REPLY_BIT)
  44
  45 struct lnet_drop_rule {
  46         /** link chain on the_lnet.ln_drop_rules */
  47         struct list_head        dr_link;
  48         /** attributes of this rule */
  49         struct lnet_fault_attr  dr_attr;
  50         /** lock to protect \a dr_drop_at and \a dr_stat */
  51         spinlock_t              dr_lock;
  52         /**
  53          * the message sequence to drop, which means message is dropped when
  54          * dr_stat.drs_count == dr_drop_at
  55          */
  56         unsigned long           dr_drop_at;
  57         /**
  58          * seconds to drop the next message, it's exclusive with dr_drop_at
  59          */
  60         cfs_time_t              dr_drop_time;
  61         /** baseline to caculate dr_drop_time */
  62         cfs_time_t              dr_time_base;
  63         /** statistic of dropped messages */
  64         struct lnet_fault_stat  dr_stat;
  65 };
  66
  67 static bool
  68 lnet_fault_nid_match(lnet_nid_t nid, lnet_nid_t msg_nid)
  69 {
  70         if (nid == msg_nid || nid == LNET_NID_ANY)
  71                 return true;
  72
  73         if (LNET_NIDNET(nid) != LNET_NIDNET(msg_nid))
  74                 return false;
  75
  76         /* 255.255.255.255@net is wildcard for all addresses in a network */
  77         return LNET_NIDADDR(nid) == LNET_NIDADDR(LNET_NID_ANY);
  78 }
  79
  80 static bool
  81 lnet_fault_attr_match(struct lnet_fault_attr *attr, lnet_nid_t src,
  82                       lnet_nid_t dst, unsigned int type, unsigned int portal)
  83 {
  84         if (!lnet_fault_nid_match(attr->fa_src, src) ||
  85             !lnet_fault_nid_match(attr->fa_dst, dst))
  86                 return false;
  87
  88         if (!(attr->fa_msg_mask & (1 << type)))
  89                 return false;
  90
  91         /* NB: ACK and REPLY have no portal, but they should have been
  92          * rejected by message mask */
  93         if (attr->fa_ptl_mask != 0 && /* has portal filter */
  94             !(attr->fa_ptl_mask & (1ULL << portal)))
  95                 return false;
  96
  97         return true;
  98 }
  99
 100 static int
 101 lnet_fault_attr_validate(struct lnet_fault_attr *attr)
 102 {
 103         if (attr->fa_msg_mask == 0)
 104                 attr->fa_msg_mask = LNET_MSG_MASK; /* all message types */
 105
 106         if (attr->fa_ptl_mask == 0) /* no portal filter */
 107                 return 0;
 108
 109         /* NB: only PUT and GET can be filtered if portal filter has been set */
 110         attr->fa_msg_mask &= LNET_GET_BIT | LNET_PUT_BIT;
 111         if (attr->fa_msg_mask == 0) {
 112                 CDEBUG(D_NET, "can't find valid message type bits %x\n",
 113                        attr->fa_msg_mask);
 114                 return -EINVAL;
 115         }
 116         return 0;
 117 }
 118
 119 static void
 120 lnet_fault_stat_inc(struct lnet_fault_stat *stat, unsigned int type)
 121 {
 122         /* NB: fs_counter is NOT updated by this function */
 123         switch (type) {
 124         case LNET_MSG_PUT:
 125                 stat->fs_put++;
 126                 return;
 127         case LNET_MSG_ACK:
 128                 stat->fs_ack++;
 129                 return;
 130         case LNET_MSG_GET:
 131                 stat->fs_get++;
 132                 return;
 133         case LNET_MSG_REPLY:
 134                 stat->fs_reply++;
 135                 return;
 136         }
 137 }
 138
 139 /**
 140  * LNet message drop simulation
 141  */
 142
 143 /**
 144  * Add a new drop rule to LNet
 145  * There is no check for duplicated drop rule, all rules will be checked for
 146  * incoming message.
 147  */
 148 static int
 149 lnet_drop_rule_add(struct lnet_fault_attr *attr)
 150 {
 151         struct lnet_drop_rule *rule;
 152         ENTRY;
 153
 154         if (!((attr->u.drop.da_rate == 0) ^ (attr->u.drop.da_interval == 0))) {
 155                 CDEBUG(D_NET,
 156                        "please provide either drop rate or drop interval, "
 157                        "but not both at the same time %d/%d\n",
 158                        attr->u.drop.da_rate, attr->u.drop.da_interval);
 159                 RETURN(-EINVAL);
 160         }
 161
 162         if (lnet_fault_attr_validate(attr) != 0)
 163                 RETURN(-EINVAL);
 164
 165         CFS_ALLOC_PTR(rule);
 166         if (rule == NULL)
 167                 RETURN(-ENOMEM);
 168
 169         spin_lock_init(&rule->dr_lock);
 170
 171         rule->dr_attr = *attr;
 172         if (attr->u.drop.da_interval != 0) {
 173                 rule->dr_time_base = cfs_time_shift(attr->u.drop.da_interval);
 174                 rule->dr_drop_time = cfs_time_shift(cfs_rand() %
 175                                                     attr->u.drop.da_interval);
 176         } else {
 177                 rule->dr_drop_at = cfs_rand() % attr->u.drop.da_rate;
 178         }
 179
 180         lnet_net_lock(LNET_LOCK_EX);
 181         list_add(&rule->dr_link, &the_lnet.ln_drop_rules);
 182         lnet_net_unlock(LNET_LOCK_EX);
 183
 184         CDEBUG(D_NET, "Added drop rule: src %s, dst %s, rate %d, interval %d\n",
 185                libcfs_nid2str(attr->fa_src), libcfs_nid2str(attr->fa_src),
 186                attr->u.drop.da_rate, attr->u.drop.da_interval);
 187         RETURN(0);
 188 }
 189
 190 /**
 191  * Remove matched drop rules from lnet, all rules that can match \a src and
 192  * \a dst will be removed.
 193  * If \a src is zero, then all rules have \a dst as destination will be remove
 194  * If \a dst is zero, then all rules have \a src as source will be removed
 195  * If both of them are zero, all rules will be removed
 196  */
 197 static int
 198 lnet_drop_rule_del(lnet_nid_t src, lnet_nid_t dst)
 199 {
 200         struct lnet_drop_rule *rule;
 201         struct lnet_drop_rule *tmp;
 202         struct list_head       zombies;
 203         int                    n = 0;
 204         ENTRY;
 205
 206         INIT_LIST_HEAD(&zombies);
 207
 208         lnet_net_lock(LNET_LOCK_EX);
 209         list_for_each_entry_safe(rule, tmp, &the_lnet.ln_drop_rules, dr_link) {
 210                 if (rule->dr_attr.fa_src != src && src != 0)
 211                         continue;
 212
 213                 if (rule->dr_attr.fa_dst != dst && dst != 0)
 214                         continue;
 215
 216                 list_move(&rule->dr_link, &zombies);
 217         }
 218         lnet_net_unlock(LNET_LOCK_EX);
 219
 220         list_for_each_entry_safe(rule, tmp, &zombies, dr_link) {
 221                 CDEBUG(D_NET, "Remove drop rule: src %s->dst: %s (1/%d, %d)\n",
 222                        libcfs_nid2str(rule->dr_attr.fa_src),
 223                        libcfs_nid2str(rule->dr_attr.fa_dst),
 224                        rule->dr_attr.u.drop.da_rate,
 225                        rule->dr_attr.u.drop.da_interval);
 226
 227                 list_del(&rule->dr_link);
 228                 CFS_FREE_PTR(rule);
 229                 n++;
 230         }
 231
 232         RETURN(n);
 233 }
 234
 235 /**
 236  * List drop rule at position of \a pos
 237  */
 238 static int
 239 lnet_drop_rule_list(int pos, struct lnet_fault_attr *attr,
 240                     struct lnet_fault_stat *stat)
 241 {
 242         struct lnet_drop_rule *rule;
 243         int                    cpt;
 244         int                    i = 0;
 245         int                    rc = -ENOENT;
 246         ENTRY;
 247
 248         cpt = lnet_net_lock_current();
 249         list_for_each_entry(rule, &the_lnet.ln_drop_rules, dr_link) {
 250                 if (i++ < pos)
 251                         continue;
 252
 253                 spin_lock(&rule->dr_lock);
 254                 *attr = rule->dr_attr;
 255                 *stat = rule->dr_stat;
 256                 spin_unlock(&rule->dr_lock);
 257                 rc = 0;
 258                 break;
 259         }
 260
 261         lnet_net_unlock(cpt);
 262         RETURN(rc);
 263 }
 264
 265 /**
 266  * reset counters for all drop rules
 267  */
 268 static void
 269 lnet_drop_rule_reset(void)
 270 {
 271         struct lnet_drop_rule *rule;
 272         int                    cpt;
 273         ENTRY;
 274
 275         cpt = lnet_net_lock_current();
 276
 277         list_for_each_entry(rule, &the_lnet.ln_drop_rules, dr_link) {
 278                 struct lnet_fault_attr *attr = &rule->dr_attr;
 279
 280                 spin_lock(&rule->dr_lock);
 281
 282                 memset(&rule->dr_stat, 0, sizeof(rule->dr_stat));
 283                 if (attr->u.drop.da_rate != 0) {
 284                         rule->dr_drop_at = cfs_rand() % attr->u.drop.da_rate;
 285                 } else {
 286                         rule->dr_drop_time = cfs_time_shift(cfs_rand() %
 287                                                 attr->u.drop.da_interval);
 288                         rule->dr_time_base = cfs_time_shift(attr->u.drop.
 289                                                                   da_interval);
 290                 }
 291                 spin_unlock(&rule->dr_lock);
 292         }
 293
 294         lnet_net_unlock(cpt);
 295         EXIT;
 296 }
 297
 298 /**
 299  * check source/destination NID, portal, message type and drop rate,
 300  * decide whether should drop this message or not
 301  */
 302 static bool
 303 drop_rule_match(struct lnet_drop_rule *rule, lnet_nid_t src,
 304                 lnet_nid_t dst, unsigned int type, unsigned int portal)
 305 {
 306         struct lnet_fault_attr  *attr = &rule->dr_attr;
 307         bool                     drop;
 308
 309         if (!lnet_fault_attr_match(attr, src, dst, type, portal))
 310                 return false;
 311
 312         /* match this rule, check drop rate now */
 313         spin_lock(&rule->dr_lock);
 314         if (rule->dr_drop_time != 0) { /* time based drop */
 315                 cfs_time_t now = cfs_time_current();
 316
 317                 rule->dr_stat.fs_count++;
 318                 drop = cfs_time_aftereq(now, rule->dr_drop_time);
 319                 if (drop) {
 320                         if (cfs_time_after(now, rule->dr_time_base))
 321                                 rule->dr_time_base = now;
 322
 323                         rule->dr_drop_time = rule->dr_time_base +
 324                                              cfs_time_seconds(cfs_rand() %
 325                                                 attr->u.drop.da_interval);
 326                         rule->dr_time_base += cfs_time_seconds(attr->u.drop.
 327                                                                da_interval);
 328
 329                         CDEBUG(D_NET, "Drop Rule %s->%s: next drop : "
 330                                       CFS_TIME_T"\n",
 331                                       libcfs_nid2str(attr->fa_src),
 332                                       libcfs_nid2str(attr->fa_dst),
 333                                       rule->dr_drop_time);
 334                 }
 335
 336         } else { /* rate based drop */
 337                 drop = rule->dr_stat.fs_count++ == rule->dr_drop_at;
 338
 339                 if (rule->dr_stat.fs_count % attr->u.drop.da_rate == 0) {
 340                         rule->dr_drop_at = rule->dr_stat.fs_count +
 341                                            cfs_rand() % attr->u.drop.da_rate;
 342                         CDEBUG(D_NET, "Drop Rule %s->%s: next drop: %lu\n",
 343                                libcfs_nid2str(attr->fa_src),
 344                                libcfs_nid2str(attr->fa_dst), rule->dr_drop_at);
 345                 }
 346         }
 347
 348         if (drop) { /* drop this message, update counters */
 349                 lnet_fault_stat_inc(&rule->dr_stat, type);
 350                 rule->dr_stat.u.drop.ds_dropped++;
 351         }
 352
 353         spin_unlock(&rule->dr_lock);
 354         return drop;
 355 }
 356
 357 /**
 358  * Check if message from \a src to \a dst can match any existed drop rule
 359  */
 360 bool
 361 lnet_drop_rule_match(lnet_hdr_t *hdr)
 362 {
 363         struct lnet_drop_rule   *rule;
 364         lnet_nid_t               src = le64_to_cpu(hdr->src_nid);
 365         lnet_nid_t               dst = le64_to_cpu(hdr->dest_nid);
 366         unsigned int             typ = le32_to_cpu(hdr->type);
 367         unsigned int             ptl = -1;
 368         bool                     drop = false;
 369         int                      cpt;
 370
 371         /* NB: if Portal is specified, then only PUT and GET will be
 372          * filtered by drop rule */
 373         if (typ == LNET_MSG_PUT)
 374                 ptl = le32_to_cpu(hdr->msg.put.ptl_index);
 375         else if (typ == LNET_MSG_GET)
 376                 ptl = le32_to_cpu(hdr->msg.get.ptl_index);
 377
 378         cpt = lnet_net_lock_current();
 379         list_for_each_entry(rule, &the_lnet.ln_drop_rules, dr_link) {
 380                 drop = drop_rule_match(rule, src, dst, typ, ptl);
 381                 if (drop)
 382                         break;
 383         }
 384
 385         lnet_net_unlock(cpt);
 386         return drop;
 387 }
 388
 389 /**
 390  * LNet Delay Simulation
 391  */
 392 /** timestamp (second) to send delayed message */
 393 #define msg_delay_send           msg_ev.hdr_data
 394
 395 struct lnet_delay_rule {
 396         /** link chain on the_lnet.ln_delay_rules */
 397         struct list_head        dl_link;
 398         /** link chain on delay_dd.dd_sched_rules */
 399         struct list_head        dl_sched_link;
 400         /** attributes of this rule */
 401         struct lnet_fault_attr  dl_attr;
 402         /** lock to protect \a below members */
 403         spinlock_t              dl_lock;
 404         /** refcount of delay rule */
 405         atomic_t                dl_refcount;
 406         /**
 407          * the message sequence to delay, which means message is delayed when
 408          * dl_stat.fs_count == dl_delay_at
 409          */
 410         unsigned long           dl_delay_at;
 411         /**
 412          * seconds to delay the next message, it's exclusive with dl_delay_at
 413          */
 414         cfs_time_t              dl_delay_time;
 415         /** baseline to caculate dl_delay_time */
 416         cfs_time_t              dl_time_base;
 417         /** jiffies to send the next delayed message */
 418         unsigned long           dl_msg_send;
 419         /** delayed message list */
 420         struct list_head        dl_msg_list;
 421         /** statistic of delayed messages */
 422         struct lnet_fault_stat  dl_stat;
 423         /** timer to wakeup delay_daemon */
 424         struct timer_list       dl_timer;
 425 };
 426
 427 struct delay_daemon_data {
 428         /** serialise rule add/remove */
 429         struct mutex            dd_mutex;
 430         /** protect rules on \a dd_sched_rules */
 431         spinlock_t              dd_lock;
 432         /** scheduled delay rules (by timer) */
 433         struct list_head        dd_sched_rules;
 434         /** deamon thread sleeps at here */
 435         wait_queue_head_t       dd_waitq;
 436         /** controler (lctl command) wait at here */
 437         wait_queue_head_t       dd_ctl_waitq;
 438         /** deamon is running */
 439         unsigned int            dd_running;
 440         /** deamon stopped */
 441         unsigned int            dd_stopped;
 442 };
 443
 444 static struct delay_daemon_data delay_dd;
 445
 446 static cfs_time_t
 447 round_timeout(cfs_time_t timeout)
 448 {
 449         return cfs_time_seconds((unsigned int)
 450                         cfs_duration_sec(cfs_time_sub(timeout, 0)) + 1);
 451 }
 452
 453 static void
 454 delay_rule_decref(struct lnet_delay_rule *rule)
 455 {
 456         if (atomic_dec_and_test(&rule->dl_refcount)) {
 457                 LASSERT(list_empty(&rule->dl_sched_link));
 458                 LASSERT(list_empty(&rule->dl_msg_list));
 459                 LASSERT(list_empty(&rule->dl_link));
 460
 461                 CFS_FREE_PTR(rule);
 462         }
 463 }
 464
 465 /**
 466  * check source/destination NID, portal, message type and delay rate,
 467  * decide whether should delay this message or not
 468  */
 469 static bool
 470 delay_rule_match(struct lnet_delay_rule *rule, lnet_nid_t src,
 471                 lnet_nid_t dst, unsigned int type, unsigned int portal,
 472                 struct lnet_msg *msg)
 473 {
 474         struct lnet_fault_attr  *attr = &rule->dl_attr;
 475         bool                     delay;
 476
 477         if (!lnet_fault_attr_match(attr, src, dst, type, portal))
 478                 return false;
 479
 480         /* match this rule, check delay rate now */
 481         spin_lock(&rule->dl_lock);
 482         if (rule->dl_delay_time != 0) { /* time based delay */
 483                 cfs_time_t now = cfs_time_current();
 484
 485                 rule->dl_stat.fs_count++;
 486                 delay = cfs_time_aftereq(now, rule->dl_delay_time);
 487                 if (delay) {
 488                         if (cfs_time_after(now, rule->dl_time_base))
 489                                 rule->dl_time_base = now;
 490
 491                         rule->dl_delay_time = rule->dl_time_base +
 492                                              cfs_time_seconds(cfs_rand() %
 493                                                 attr->u.delay.la_interval);
 494                         rule->dl_time_base += cfs_time_seconds(attr->u.delay.
 495                                                                la_interval);
 496
 497                         CDEBUG(D_NET, "Delay Rule %s->%s: next delay : "
 498                                       CFS_TIME_T"\n",
 499                                       libcfs_nid2str(attr->fa_src),
 500                                       libcfs_nid2str(attr->fa_dst),
 501                                       rule->dl_delay_time);
 502                 }
 503
 504         } else { /* rate based delay */
 505                 delay = rule->dl_stat.fs_count++ == rule->dl_delay_at;
 506                 /* generate the next random rate sequence */
 507                 if (rule->dl_stat.fs_count % attr->u.delay.la_rate == 0) {
 508                         rule->dl_delay_at = rule->dl_stat.fs_count +
 509                                             cfs_rand() % attr->u.delay.la_rate;
 510                         CDEBUG(D_NET, "Delay Rule %s->%s: next delay: %lu\n",
 511                                libcfs_nid2str(attr->fa_src),
 512                                libcfs_nid2str(attr->fa_dst), rule->dl_delay_at);
 513                 }
 514         }
 515
 516         if (!delay) {
 517                 spin_unlock(&rule->dl_lock);
 518                 return false;
 519         }
 520
 521         /* delay this message, update counters */
 522         lnet_fault_stat_inc(&rule->dl_stat, type);
 523         rule->dl_stat.u.delay.ls_delayed++;
 524
 525         list_add_tail(&msg->msg_list, &rule->dl_msg_list);
 526         msg->msg_delay_send = round_timeout(
 527                         cfs_time_shift(attr->u.delay.la_latency));
 528         if (rule->dl_msg_send == -1) {
 529                 rule->dl_msg_send = msg->msg_delay_send;
 530                 mod_timer(&rule->dl_timer, rule->dl_msg_send);
 531         }
 532
 533         spin_unlock(&rule->dl_lock);
 534         return true;
 535 }
 536
 537 /**
 538  * check if \a msg can match any Delay Rule, receiving of this message
 539  * will be delayed if there is a match.
 540  */
 541 bool
 542 lnet_delay_rule_match_locked(lnet_hdr_t *hdr, struct lnet_msg *msg)
 543 {
 544         struct lnet_delay_rule  *rule;
 545         lnet_nid_t               src = le64_to_cpu(hdr->src_nid);
 546         lnet_nid_t               dst = le64_to_cpu(hdr->dest_nid);
 547         unsigned int             typ = le32_to_cpu(hdr->type);
 548         unsigned int             ptl = -1;
 549
 550         /* NB: called with hold of lnet_net_lock */
 551
 552         /* NB: if Portal is specified, then only PUT and GET will be
 553          * filtered by delay rule */
 554         if (typ == LNET_MSG_PUT)
 555                 ptl = le32_to_cpu(hdr->msg.put.ptl_index);
 556         else if (typ == LNET_MSG_GET)
 557                 ptl = le32_to_cpu(hdr->msg.get.ptl_index);
 558
 559         list_for_each_entry(rule, &the_lnet.ln_delay_rules, dl_link) {
 560                 if (delay_rule_match(rule, src, dst, typ, ptl, msg))
 561                         return true;
 562         }
 563
 564         return false;
 565 }
 566
 567 /** check out delayed messages for send */
 568 static void
 569 delayed_msg_check(struct lnet_delay_rule *rule, bool all,
 570                   struct list_head *msg_list)
 571 {
 572         struct lnet_msg *msg;
 573         struct lnet_msg *tmp;
 574         unsigned long    now = cfs_time_current();
 575
 576         if (!all && rule->dl_msg_send > now)
 577                 return;
 578
 579         spin_lock(&rule->dl_lock);
 580         list_for_each_entry_safe(msg, tmp, &rule->dl_msg_list, msg_list) {
 581                 if (!all && msg->msg_delay_send > now)
 582                         break;
 583
 584                 msg->msg_delay_send = 0;
 585                 list_move_tail(&msg->msg_list, msg_list);
 586         }
 587
 588         if (list_empty(&rule->dl_msg_list)) {
 589                 del_timer(&rule->dl_timer);
 590                 rule->dl_msg_send = -1;
 591
 592         } else if (!list_empty(msg_list)) {
 593                 /* dequeued some timedout messages, update timer for the
 594                  * next delayed message on rule */
 595                 msg = list_entry(rule->dl_msg_list.next,
 596                                  struct lnet_msg, msg_list);
 597                 rule->dl_msg_send = msg->msg_delay_send;
 598                 mod_timer(&rule->dl_timer, rule->dl_msg_send);
 599         }
 600         spin_unlock(&rule->dl_lock);
 601 }
 602
 603 static void
 604 delayed_msg_process(struct list_head *msg_list, bool drop)
 605 {
 606         struct lnet_msg *msg;
 607
 608         while (!list_empty(msg_list)) {
 609                 struct lnet_ni *ni;
 610                 int             cpt;
 611                 int             rc;
 612
 613                 msg = list_entry(msg_list->next, struct lnet_msg, msg_list);
 614                 LASSERT(msg->msg_rxpeer != NULL);
 615
 616                 ni = msg->msg_rxpeer->lp_ni;
 617                 cpt = msg->msg_rx_cpt;
 618
 619                 list_del_init(&msg->msg_list);
 620                 if (drop) {
 621                         rc = -ECANCELED;
 622
 623                 } else if (!msg->msg_routing) {
 624                         rc = lnet_parse_local(ni, msg);
 625                         if (rc == 0)
 626                                 continue;
 627
 628                 } else {
 629                         lnet_net_lock(cpt);
 630                         rc = lnet_parse_forward_locked(ni, msg);
 631                         lnet_net_unlock(cpt);
 632
 633                         switch (rc) {
 634                         case LNET_CREDIT_OK:
 635                                 lnet_ni_recv(ni, msg->msg_private, msg, 0,
 636                                              0, msg->msg_len, msg->msg_len);
 637                         case LNET_CREDIT_WAIT:
 638                                 continue;
 639                         default: /* failures */
 640                                 break;
 641                         }
 642                 }
 643
 644                 lnet_drop_message(ni, cpt, msg->msg_private, msg->msg_len);
 645                 lnet_finalize(ni, msg, rc);
 646         }
 647 }
 648
 649 /**
 650  * Process delayed messages for scheduled rules
 651  * This function can either be called by delay_rule_daemon, or by lnet_finalise
 652  */
 653 void
 654 lnet_delay_rule_check(void)
 655 {
 656         struct lnet_delay_rule  *rule;
 657         struct list_head         msgs;
 658
 659         INIT_LIST_HEAD(&msgs);
 660         while (1) {
 661                 if (list_empty(&delay_dd.dd_sched_rules))
 662                         break;
 663
 664                 spin_lock_bh(&delay_dd.dd_lock);
 665                 if (list_empty(&delay_dd.dd_sched_rules)) {
 666                         spin_unlock_bh(&delay_dd.dd_lock);
 667                         break;
 668                 }
 669
 670                 rule = list_entry(delay_dd.dd_sched_rules.next,
 671                                   struct lnet_delay_rule, dl_sched_link);
 672                 list_del_init(&rule->dl_sched_link);
 673                 spin_unlock_bh(&delay_dd.dd_lock);
 674
 675                 delayed_msg_check(rule, false, &msgs);
 676                 delay_rule_decref(rule); /* -1 for delay_dd.dd_sched_rules */
 677         }
 678
 679         if (!list_empty(&msgs))
 680                 delayed_msg_process(&msgs, false);
 681 }
 682
 683 /** deamon thread to handle delayed messages */
 684 static int
 685 lnet_delay_rule_daemon(void *arg)
 686 {
 687         delay_dd.dd_running = 1;
 688         wake_up(&delay_dd.dd_ctl_waitq);
 689
 690         while (delay_dd.dd_running) {
 691                 wait_event_interruptible(delay_dd.dd_waitq,
 692                                          !delay_dd.dd_running ||
 693                                          !list_empty(&delay_dd.dd_sched_rules));
 694                 lnet_delay_rule_check();
 695         }
 696
 697         /* in case more rules have been enqueued after my last check */
 698         lnet_delay_rule_check();
 699         delay_dd.dd_stopped = 1;
 700         wake_up(&delay_dd.dd_ctl_waitq);
 701
 702         return 0;
 703 }
 704
 705 static void
 706 delay_timer_cb(unsigned long arg)
 707 {
 708         struct lnet_delay_rule *rule = (struct lnet_delay_rule *)arg;
 709
 710         spin_lock_bh(&delay_dd.dd_lock);
 711         if (list_empty(&rule->dl_sched_link) && delay_dd.dd_running) {
 712                 atomic_inc(&rule->dl_refcount);
 713                 list_add_tail(&rule->dl_sched_link, &delay_dd.dd_sched_rules);
 714                 wake_up(&delay_dd.dd_waitq);
 715         }
 716         spin_unlock_bh(&delay_dd.dd_lock);
 717 }
 718
 719 /**
 720  * Add a new delay rule to LNet
 721  * There is no check for duplicated delay rule, all rules will be checked for
 722  * incoming message.
 723  */
 724 int
 725 lnet_delay_rule_add(struct lnet_fault_attr *attr)
 726 {
 727         struct lnet_delay_rule *rule;
 728         int                     rc = 0;
 729         ENTRY;
 730
 731         if (!((attr->u.delay.la_rate == 0) ^
 732               (attr->u.delay.la_interval == 0))) {
 733                 CDEBUG(D_NET,
 734                        "please provide either delay rate or delay interval, "
 735                        "but not both at the same time %d/%d\n",
 736                        attr->u.delay.la_rate, attr->u.delay.la_interval);
 737                 RETURN(-EINVAL);
 738         }
 739
 740         if (attr->u.delay.la_latency == 0) {
 741                 CDEBUG(D_NET, "delay latency cannot be zero\n");
 742                 RETURN(-EINVAL);
 743         }
 744
 745         if (lnet_fault_attr_validate(attr) != 0)
 746                 RETURN(-EINVAL);
 747
 748         CFS_ALLOC_PTR(rule);
 749         if (rule == NULL)
 750                 RETURN(-ENOMEM);
 751
 752         mutex_lock(&delay_dd.dd_mutex);
 753         if (!delay_dd.dd_running) {
 754                 struct task_struct *task;
 755
 756                 /* NB: although LND threads will process delayed message
 757                  * in lnet_finalize, but there is no guarantee that LND
 758                  * threads will be waken up if no other message needs to
 759                  * be handled.
 760                  * Only one daemon thread, performance is not the concern
 761                  * of this simualation module.
 762                  */
 763                 task = kthread_run(lnet_delay_rule_daemon, NULL, "lnet_dd");
 764                 if (IS_ERR(task)) {
 765                         rc = PTR_ERR(task);
 766                         GOTO(failed, rc);
 767                 }
 768                 wait_event(delay_dd.dd_ctl_waitq, delay_dd.dd_running);
 769         }
 770
 771         init_timer(&rule->dl_timer);
 772         rule->dl_timer.function = delay_timer_cb;
 773         rule->dl_timer.data = (unsigned long)rule;
 774
 775         spin_lock_init(&rule->dl_lock);
 776         INIT_LIST_HEAD(&rule->dl_msg_list);
 777         INIT_LIST_HEAD(&rule->dl_sched_link);
 778
 779         rule->dl_attr = *attr;
 780         if (attr->u.delay.la_interval != 0) {
 781                 rule->dl_time_base = cfs_time_shift(attr->u.delay.la_interval);
 782                 rule->dl_delay_time = cfs_time_shift(cfs_rand() %
 783                                                      attr->u.delay.la_interval);
 784         } else {
 785                 rule->dl_delay_at = cfs_rand() % attr->u.delay.la_rate;
 786         }
 787
 788         rule->dl_msg_send = -1;
 789
 790         lnet_net_lock(LNET_LOCK_EX);
 791         atomic_set(&rule->dl_refcount, 1);
 792         list_add(&rule->dl_link, &the_lnet.ln_delay_rules);
 793         lnet_net_unlock(LNET_LOCK_EX);
 794
 795         CDEBUG(D_NET, "Added delay rule: src %s, dst %s, rate %d\n",
 796                libcfs_nid2str(attr->fa_src), libcfs_nid2str(attr->fa_src),
 797                attr->u.delay.la_rate);
 798
 799         mutex_unlock(&delay_dd.dd_mutex);
 800         RETURN(0);
 801  failed:
 802         mutex_unlock(&delay_dd.dd_mutex);
 803         CFS_FREE_PTR(rule);
 804         return rc;
 805 }
 806
 807 /**
 808  * Remove matched Delay Rules from lnet, if \a shutdown is true or both \a src
 809  * and \a dst are zero, all rules will be removed, otherwise only matched rules
 810  * will be removed.
 811  * If \a src is zero, then all rules have \a dst as destination will be remove
 812  * If \a dst is zero, then all rules have \a src as source will be removed
 813  *
 814  * When a delay rule is removed, all delayed messages of this rule will be
 815  * processed immediately.
 816  */
 817 int
 818 lnet_delay_rule_del(lnet_nid_t src, lnet_nid_t dst, bool shutdown)
 819 {
 820         struct lnet_delay_rule *rule;
 821         struct lnet_delay_rule  *tmp;
 822         struct list_head        rule_list;
 823         struct list_head        msg_list;
 824         int                     n = 0;
 825         bool                    cleanup;
 826         ENTRY;
 827
 828         INIT_LIST_HEAD(&rule_list);
 829         INIT_LIST_HEAD(&msg_list);
 830
 831         if (shutdown)
 832                 src = dst = 0;
 833
 834         mutex_lock(&delay_dd.dd_mutex);
 835         lnet_net_lock(LNET_LOCK_EX);
 836
 837         list_for_each_entry_safe(rule, tmp, &the_lnet.ln_delay_rules, dl_link) {
 838                 if (rule->dl_attr.fa_src != src && src != 0)
 839                         continue;
 840
 841                 if (rule->dl_attr.fa_dst != dst && dst != 0)
 842                         continue;
 843
 844                 CDEBUG(D_NET, "Remove delay rule: src %s->dst: %s (1/%d, %d)\n",
 845                        libcfs_nid2str(rule->dl_attr.fa_src),
 846                        libcfs_nid2str(rule->dl_attr.fa_dst),
 847                        rule->dl_attr.u.delay.la_rate,
 848                        rule->dl_attr.u.delay.la_interval);
 849                 /* refcount is taken over by rule_list */
 850                 list_move(&rule->dl_link, &rule_list);
 851         }
 852
 853         /* check if we need to shutdown delay_daemon */
 854         cleanup = list_empty(&the_lnet.ln_delay_rules) &&
 855                   !list_empty(&rule_list);
 856         lnet_net_unlock(LNET_LOCK_EX);
 857
 858         list_for_each_entry_safe(rule, tmp, &rule_list, dl_link) {
 859                 list_del_init(&rule->dl_link);
 860
 861                 del_timer_sync(&rule->dl_timer);
 862                 delayed_msg_check(rule, true, &msg_list);
 863                 delay_rule_decref(rule); /* -1 for the_lnet.ln_delay_rules */
 864                 n++;
 865         }
 866
 867         if (cleanup) { /* no more delay rule, shutdown delay_daemon */
 868                 LASSERT(delay_dd.dd_running);
 869                 delay_dd.dd_running = 0;
 870                 wake_up(&delay_dd.dd_waitq);
 871
 872                 while (!delay_dd.dd_stopped)
 873                         wait_event(delay_dd.dd_ctl_waitq, delay_dd.dd_stopped);
 874         }
 875         mutex_unlock(&delay_dd.dd_mutex);
 876
 877         if (!list_empty(&msg_list))
 878                 delayed_msg_process(&msg_list, shutdown);
 879
 880         RETURN(n);
 881 }
 882
 883 /**
 884  * List Delay Rule at position of \a pos
 885  */
 886 int
 887 lnet_delay_rule_list(int pos, struct lnet_fault_attr *attr,
 888                     struct lnet_fault_stat *stat)
 889 {
 890         struct lnet_delay_rule *rule;
 891         int                     cpt;
 892         int                     i = 0;
 893         int                     rc = -ENOENT;
 894         ENTRY;
 895
 896         cpt = lnet_net_lock_current();
 897         list_for_each_entry(rule, &the_lnet.ln_delay_rules, dl_link) {
 898                 if (i++ < pos)
 899                         continue;
 900
 901                 spin_lock(&rule->dl_lock);
 902                 *attr = rule->dl_attr;
 903                 *stat = rule->dl_stat;
 904                 spin_unlock(&rule->dl_lock);
 905                 rc = 0;
 906                 break;
 907         }
 908
 909         lnet_net_unlock(cpt);
 910         RETURN(rc);
 911 }
 912
 913 /**
 914  * reset counters for all Delay Rules
 915  */
 916 void
 917 lnet_delay_rule_reset(void)
 918 {
 919         struct lnet_delay_rule *rule;
 920         int                     cpt;
 921         ENTRY;
 922
 923         cpt = lnet_net_lock_current();
 924
 925         list_for_each_entry(rule, &the_lnet.ln_delay_rules, dl_link) {
 926                 struct lnet_fault_attr *attr = &rule->dl_attr;
 927
 928                 spin_lock(&rule->dl_lock);
 929
 930                 memset(&rule->dl_stat, 0, sizeof(rule->dl_stat));
 931                 if (attr->u.delay.la_rate != 0) {
 932                         rule->dl_delay_at = cfs_rand() % attr->u.delay.la_rate;
 933                 } else {
 934                         rule->dl_delay_time = cfs_time_shift(cfs_rand() %
 935                                                 attr->u.delay.la_interval);
 936                         rule->dl_time_base = cfs_time_shift(attr->u.delay.
 937                                                                   la_interval);
 938                 }
 939                 spin_unlock(&rule->dl_lock);
 940         }
 941
 942         lnet_net_unlock(cpt);
 943         EXIT;
 944 }
 945
 946 int
 947 lnet_fault_ctl(int opc, struct libcfs_ioctl_data *data)
 948 {
 949         struct lnet_fault_attr *attr;
 950         struct lnet_fault_stat *stat;
 951
 952         attr = (struct lnet_fault_attr *)data->ioc_inlbuf1;
 953
 954         switch (opc) {
 955         default:
 956                 return -EINVAL;
 957
 958         case LNET_CTL_DROP_ADD:
 959                 if (attr == NULL)
 960                         return -EINVAL;
 961
 962                 return lnet_drop_rule_add(attr);
 963
 964         case LNET_CTL_DROP_DEL:
 965                 if (attr == NULL)
 966                         return -EINVAL;
 967
 968                 data->ioc_count = lnet_drop_rule_del(attr->fa_src,
 969                                                      attr->fa_dst);
 970                 return 0;
 971
 972         case LNET_CTL_DROP_RESET:
 973                 lnet_drop_rule_reset();
 974                 return 0;
 975
 976         case LNET_CTL_DROP_LIST:
 977                 stat = (struct lnet_fault_stat *)data->ioc_inlbuf2;
 978                 if (attr == NULL || stat == NULL)
 979                         return -EINVAL;
 980
 981                 return lnet_drop_rule_list(data->ioc_count, attr, stat);
 982
 983         case LNET_CTL_DELAY_ADD:
 984                 if (attr == NULL)
 985                         return -EINVAL;
 986
 987                 return lnet_delay_rule_add(attr);
 988
 989         case LNET_CTL_DELAY_DEL:
 990                 if (attr == NULL)
 991                         return -EINVAL;
 992
 993                 data->ioc_count = lnet_delay_rule_del(attr->fa_src,
 994                                                       attr->fa_dst, false);
 995                 return 0;
 996
 997         case LNET_CTL_DELAY_RESET:
 998                 lnet_delay_rule_reset();
 999                 return 0;
1000
1001         case LNET_CTL_DELAY_LIST:
1002                 stat = (struct lnet_fault_stat *)data->ioc_inlbuf2;
1003                 if (attr == NULL || stat == NULL)
1004                         return -EINVAL;
1005
1006                 return lnet_delay_rule_list(data->ioc_count, attr, stat);
1007         }
1008 }
1009
1010 int
1011 lnet_fault_init(void)
1012 {
1013         CLASSERT(LNET_PUT_BIT == 1 << LNET_MSG_PUT);
1014         CLASSERT(LNET_ACK_BIT == 1 << LNET_MSG_ACK);
1015         CLASSERT(LNET_GET_BIT == 1 << LNET_MSG_GET);
1016         CLASSERT(LNET_REPLY_BIT == 1 << LNET_MSG_REPLY);
1017
1018         mutex_init(&delay_dd.dd_mutex);
1019         spin_lock_init(&delay_dd.dd_lock);
1020         init_waitqueue_head(&delay_dd.dd_waitq);
1021         init_waitqueue_head(&delay_dd.dd_ctl_waitq);
1022         INIT_LIST_HEAD(&delay_dd.dd_sched_rules);
1023
1024         return 0;
1025 }
1026
1027 void
1028 lnet_fault_fini(void)
1029 {
1030         lnet_drop_rule_del(0, 0);
1031         lnet_delay_rule_del(0, 0, true);
1032
1033         LASSERT(list_empty(&the_lnet.ln_drop_rules));
1034         LASSERT(list_empty(&the_lnet.ln_delay_rules));
1035         LASSERT(list_empty(&delay_dd.dd_sched_rules));
1036 }