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, 2017, 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 <linux/random.h>
  40 #include <lnet/lib-lnet.h>
  41 #include <uapi/linux/lnet/lnetctl.h>
  42
  43 #define LNET_MSG_MASK           (LNET_PUT_BIT | LNET_ACK_BIT | \
  44                                  LNET_GET_BIT | LNET_REPLY_BIT)
  45
  46 struct lnet_drop_rule {
  47         /** link chain on the_lnet.ln_drop_rules */
  48         struct list_head        dr_link;
  49         /** attributes of this rule */
  50         struct lnet_fault_attr  dr_attr;
  51         /** lock to protect \a dr_drop_at and \a dr_stat */
  52         spinlock_t              dr_lock;
  53         /**
  54          * the message sequence to drop, which means message is dropped when
  55          * dr_stat.drs_count == dr_drop_at
  56          */
  57         unsigned long           dr_drop_at;
  58         /**
  59          * seconds to drop the next message, it's exclusive with dr_drop_at
  60          */
  61         time64_t                dr_drop_time;
  62         /** baseline to caculate dr_drop_time */
  63         time64_t                dr_time_base;
  64         /** statistic of dropped messages */
  65         struct lnet_fault_stat  dr_stat;
  66 };
  67
  68 static bool
  69 lnet_fault_nid_match(lnet_nid_t nid, lnet_nid_t msg_nid)
  70 {
  71         if (nid == msg_nid || nid == LNET_NID_ANY)
  72                 return true;
  73
  74         if (LNET_NIDNET(nid) != LNET_NIDNET(msg_nid))
  75                 return false;
  76
  77         /* 255.255.255.255@net is wildcard for all addresses in a network */
  78         return LNET_NIDADDR(nid) == LNET_NIDADDR(LNET_NID_ANY);
  79 }
  80
  81 static bool
  82 lnet_fault_attr_match(struct lnet_fault_attr *attr, lnet_nid_t src,
  83                       lnet_nid_t local_nid, lnet_nid_t dst,
  84                       unsigned int type, unsigned int portal)
  85 {
  86         if (!lnet_fault_nid_match(attr->fa_src, src) ||
  87             !lnet_fault_nid_match(attr->fa_dst, dst) ||
  88             !lnet_fault_nid_match(attr->fa_local_nid, local_nid))
  89                 return false;
  90
  91         if (!(attr->fa_msg_mask & (1 << type)))
  92                 return false;
  93
  94         /* NB: ACK and REPLY have no portal, but they should have been
  95          * rejected by message mask */
  96         if (attr->fa_ptl_mask != 0 && /* has portal filter */
  97             !(attr->fa_ptl_mask & (1ULL << portal)))
  98                 return false;
  99
 100         return true;
 101 }
 102
 103 static int
 104 lnet_fault_attr_validate(struct lnet_fault_attr *attr)
 105 {
 106         if (attr->fa_msg_mask == 0)
 107                 attr->fa_msg_mask = LNET_MSG_MASK; /* all message types */
 108
 109         if (attr->fa_ptl_mask == 0) /* no portal filter */
 110                 return 0;
 111
 112         /* NB: only PUT and GET can be filtered if portal filter has been set */
 113         attr->fa_msg_mask &= LNET_GET_BIT | LNET_PUT_BIT;
 114         if (attr->fa_msg_mask == 0) {
 115                 CDEBUG(D_NET, "can't find valid message type bits %x\n",
 116                        attr->fa_msg_mask);
 117                 return -EINVAL;
 118         }
 119         return 0;
 120 }
 121
 122 static void
 123 lnet_fault_stat_inc(struct lnet_fault_stat *stat, unsigned int type)
 124 {
 125         /* NB: fs_counter is NOT updated by this function */
 126         switch (type) {
 127         case LNET_MSG_PUT:
 128                 stat->fs_put++;
 129                 return;
 130         case LNET_MSG_ACK:
 131                 stat->fs_ack++;
 132                 return;
 133         case LNET_MSG_GET:
 134                 stat->fs_get++;
 135                 return;
 136         case LNET_MSG_REPLY:
 137                 stat->fs_reply++;
 138                 return;
 139         }
 140 }
 141
 142 /**
 143  * LNet message drop simulation
 144  */
 145
 146 /**
 147  * Add a new drop rule to LNet
 148  * There is no check for duplicated drop rule, all rules will be checked for
 149  * incoming message.
 150  */
 151 static int
 152 lnet_drop_rule_add(struct lnet_fault_attr *attr)
 153 {
 154         struct lnet_drop_rule *rule;
 155         ENTRY;
 156
 157         if (!((attr->u.drop.da_rate == 0) ^ (attr->u.drop.da_interval == 0))) {
 158                 CDEBUG(D_NET,
 159                        "please provide either drop rate or drop interval, "
 160                        "but not both at the same time %d/%d\n",
 161                        attr->u.drop.da_rate, attr->u.drop.da_interval);
 162                 RETURN(-EINVAL);
 163         }
 164
 165         if (lnet_fault_attr_validate(attr) != 0)
 166                 RETURN(-EINVAL);
 167
 168         CFS_ALLOC_PTR(rule);
 169         if (rule == NULL)
 170                 RETURN(-ENOMEM);
 171
 172         spin_lock_init(&rule->dr_lock);
 173
 174         rule->dr_attr = *attr;
 175         if (attr->u.drop.da_interval != 0) {
 176                 rule->dr_time_base = ktime_get_seconds() + attr->u.drop.da_interval;
 177                 rule->dr_drop_time = ktime_get_seconds() +
 178                                      prandom_u32_max(attr->u.drop.da_interval);
 179         } else {
 180                 rule->dr_drop_at = prandom_u32_max(attr->u.drop.da_rate);
 181         }
 182
 183         lnet_net_lock(LNET_LOCK_EX);
 184         list_add(&rule->dr_link, &the_lnet.ln_drop_rules);
 185         lnet_net_unlock(LNET_LOCK_EX);
 186
 187         CDEBUG(D_NET, "Added drop rule: src %s, dst %s, rate %d, interval %d\n",
 188                libcfs_nid2str(attr->fa_src), libcfs_nid2str(attr->fa_src),
 189                attr->u.drop.da_rate, attr->u.drop.da_interval);
 190         RETURN(0);
 191 }
 192
 193 /**
 194  * Remove matched drop rules from lnet, all rules that can match \a src and
 195  * \a dst will be removed.
 196  * If \a src is zero, then all rules have \a dst as destination will be remove
 197  * If \a dst is zero, then all rules have \a src as source will be removed
 198  * If both of them are zero, all rules will be removed
 199  */
 200 static int
 201 lnet_drop_rule_del(lnet_nid_t src, lnet_nid_t dst)
 202 {
 203         struct lnet_drop_rule *rule;
 204         struct lnet_drop_rule *tmp;
 205         LIST_HEAD(zombies);
 206         int n = 0;
 207         ENTRY;
 208
 209         lnet_net_lock(LNET_LOCK_EX);
 210         list_for_each_entry_safe(rule, tmp, &the_lnet.ln_drop_rules, dr_link) {
 211                 if (rule->dr_attr.fa_src != src && src != 0)
 212                         continue;
 213
 214                 if (rule->dr_attr.fa_dst != dst && dst != 0)
 215                         continue;
 216
 217                 list_move(&rule->dr_link, &zombies);
 218         }
 219         lnet_net_unlock(LNET_LOCK_EX);
 220
 221         list_for_each_entry_safe(rule, tmp, &zombies, dr_link) {
 222                 CDEBUG(D_NET, "Remove drop rule: src %s->dst: %s (1/%d, %d)\n",
 223                        libcfs_nid2str(rule->dr_attr.fa_src),
 224                        libcfs_nid2str(rule->dr_attr.fa_dst),
 225                        rule->dr_attr.u.drop.da_rate,
 226                        rule->dr_attr.u.drop.da_interval);
 227
 228                 list_del(&rule->dr_link);
 229                 CFS_FREE_PTR(rule);
 230                 n++;
 231         }
 232
 233         RETURN(n);
 234 }
 235
 236 /**
 237  * List drop rule at position of \a pos
 238  */
 239 static int
 240 lnet_drop_rule_list(int pos, struct lnet_fault_attr *attr,
 241                     struct lnet_fault_stat *stat)
 242 {
 243         struct lnet_drop_rule *rule;
 244         int                    cpt;
 245         int                    i = 0;
 246         int                    rc = -ENOENT;
 247         ENTRY;
 248
 249         cpt = lnet_net_lock_current();
 250         list_for_each_entry(rule, &the_lnet.ln_drop_rules, dr_link) {
 251                 if (i++ < pos)
 252                         continue;
 253
 254                 spin_lock(&rule->dr_lock);
 255                 *attr = rule->dr_attr;
 256                 *stat = rule->dr_stat;
 257                 spin_unlock(&rule->dr_lock);
 258                 rc = 0;
 259                 break;
 260         }
 261
 262         lnet_net_unlock(cpt);
 263         RETURN(rc);
 264 }
 265
 266 /**
 267  * reset counters for all drop rules
 268  */
 269 static void
 270 lnet_drop_rule_reset(void)
 271 {
 272         struct lnet_drop_rule *rule;
 273         int                    cpt;
 274         ENTRY;
 275
 276         cpt = lnet_net_lock_current();
 277
 278         list_for_each_entry(rule, &the_lnet.ln_drop_rules, dr_link) {
 279                 struct lnet_fault_attr *attr = &rule->dr_attr;
 280
 281                 spin_lock(&rule->dr_lock);
 282
 283                 memset(&rule->dr_stat, 0, sizeof(rule->dr_stat));
 284                 if (attr->u.drop.da_rate != 0) {
 285                         rule->dr_drop_at = prandom_u32_max(attr->u.drop.da_rate);
 286                 } else {
 287                         rule->dr_drop_time = ktime_get_seconds() +
 288                                              prandom_u32_max(attr->u.drop.da_interval);
 289                         rule->dr_time_base = ktime_get_seconds() + attr->u.drop.da_interval;
 290                 }
 291                 spin_unlock(&rule->dr_lock);
 292         }
 293
 294         lnet_net_unlock(cpt);
 295         EXIT;
 296 }
 297
 298 static void
 299 lnet_fault_match_health(enum lnet_msg_hstatus *hstatus, __u32 mask)
 300 {
 301         int choice;
 302         int delta;
 303         int best_delta;
 304         int i;
 305
 306         /* assign a random failure */
 307         choice = prandom_u32_max(LNET_MSG_STATUS_END - LNET_MSG_STATUS_OK);
 308         if (choice == 0)
 309                 choice++;
 310
 311         if (mask == HSTATUS_RANDOM) {
 312                 *hstatus = choice;
 313                 return;
 314         }
 315
 316         if (mask & (1 << choice)) {
 317                 *hstatus = choice;
 318                 return;
 319         }
 320
 321         /* round to the closest ON bit */
 322         i = HSTATUS_END;
 323         best_delta = HSTATUS_END;
 324         while (i > 0) {
 325                 if (mask & (1 << i)) {
 326                         delta = choice - i;
 327                         if (delta < 0)
 328                                 delta *= -1;
 329                         if (delta < best_delta) {
 330                                 best_delta = delta;
 331                                 choice = i;
 332                         }
 333                 }
 334                 i--;
 335         }
 336
 337         *hstatus = choice;
 338 }
 339
 340 /**
 341  * check source/destination NID, portal, message type and drop rate,
 342  * decide whether should drop this message or not
 343  */
 344 static bool
 345 drop_rule_match(struct lnet_drop_rule *rule, lnet_nid_t src,
 346                 lnet_nid_t local_nid, lnet_nid_t dst,
 347                 unsigned int type, unsigned int portal,
 348                 enum lnet_msg_hstatus *hstatus)
 349 {
 350         struct lnet_fault_attr  *attr = &rule->dr_attr;
 351         bool                     drop;
 352
 353         if (!lnet_fault_attr_match(attr, src, local_nid, dst, type, portal))
 354                 return false;
 355
 356         if (attr->u.drop.da_drop_all) {
 357                 CDEBUG(D_NET, "set to drop all messages\n");
 358                 drop = true;
 359                 goto drop_matched;
 360         }
 361
 362         /*
 363          * if we're trying to match a health status error but it hasn't
 364          * been set in the rule, then don't match
 365          */
 366         if ((hstatus && !attr->u.drop.da_health_error_mask) ||
 367             (!hstatus && attr->u.drop.da_health_error_mask))
 368                 return false;
 369
 370         /* match this rule, check drop rate now */
 371         spin_lock(&rule->dr_lock);
 372         if (attr->u.drop.da_random) {
 373                 int value = prandom_u32_max(attr->u.drop.da_interval);
 374                 if (value >= (attr->u.drop.da_interval / 2))
 375                         drop = true;
 376                 else
 377                         drop = false;
 378         } else if (rule->dr_drop_time != 0) { /* time based drop */
 379                 time64_t now = ktime_get_seconds();
 380
 381                 rule->dr_stat.fs_count++;
 382                 drop = now >= rule->dr_drop_time;
 383                 if (drop) {
 384                         if (now > rule->dr_time_base)
 385                                 rule->dr_time_base = now;
 386
 387                         rule->dr_drop_time = rule->dr_time_base +
 388                                              prandom_u32_max(attr->u.drop.da_interval);
 389                         rule->dr_time_base += attr->u.drop.da_interval;
 390
 391                         CDEBUG(D_NET, "Drop Rule %s->%s: next drop : %lld\n",
 392                                libcfs_nid2str(attr->fa_src),
 393                                libcfs_nid2str(attr->fa_dst),
 394                                rule->dr_drop_time);
 395                 }
 396
 397         } else { /* rate based drop */
 398                 __u64 count;
 399
 400                 drop = rule->dr_stat.fs_count++ == rule->dr_drop_at;
 401                 count = rule->dr_stat.fs_count;
 402                 if (do_div(count, attr->u.drop.da_rate) == 0) {
 403                         rule->dr_drop_at = rule->dr_stat.fs_count +
 404                                            prandom_u32_max(attr->u.drop.da_rate);
 405                         CDEBUG(D_NET, "Drop Rule %s->%s: next drop: %lu\n",
 406                                libcfs_nid2str(attr->fa_src),
 407                                libcfs_nid2str(attr->fa_dst), rule->dr_drop_at);
 408                 }
 409         }
 410
 411 drop_matched:
 412
 413         if (drop) { /* drop this message, update counters */
 414                 if (hstatus)
 415                         lnet_fault_match_health(hstatus,
 416                                 attr->u.drop.da_health_error_mask);
 417                 lnet_fault_stat_inc(&rule->dr_stat, type);
 418                 rule->dr_stat.u.drop.ds_dropped++;
 419         }
 420
 421         spin_unlock(&rule->dr_lock);
 422         return drop;
 423 }
 424
 425 /**
 426  * Check if message from \a src to \a dst can match any existed drop rule
 427  */
 428 bool
 429 lnet_drop_rule_match(struct lnet_hdr *hdr,
 430                      lnet_nid_t local_nid,
 431                      enum lnet_msg_hstatus *hstatus)
 432 {
 433         lnet_nid_t src = le64_to_cpu(hdr->src_nid);
 434         lnet_nid_t dst = le64_to_cpu(hdr->dest_nid);
 435         unsigned int typ = le32_to_cpu(hdr->type);
 436         struct lnet_drop_rule *rule;
 437         unsigned int ptl = -1;
 438         bool drop = false;
 439         int cpt;
 440
 441         /* NB: if Portal is specified, then only PUT and GET will be
 442          * filtered by drop rule */
 443         if (typ == LNET_MSG_PUT)
 444                 ptl = le32_to_cpu(hdr->msg.put.ptl_index);
 445         else if (typ == LNET_MSG_GET)
 446                 ptl = le32_to_cpu(hdr->msg.get.ptl_index);
 447
 448         cpt = lnet_net_lock_current();
 449         list_for_each_entry(rule, &the_lnet.ln_drop_rules, dr_link) {
 450                 drop = drop_rule_match(rule, src, local_nid, dst, typ, ptl,
 451                                        hstatus);
 452                 if (drop)
 453                         break;
 454         }
 455         lnet_net_unlock(cpt);
 456
 457         return drop;
 458 }
 459
 460 /**
 461  * LNet Delay Simulation
 462  */
 463 /** timestamp (second) to send delayed message */
 464 #define msg_delay_send           msg_ev.hdr_data
 465
 466 struct lnet_delay_rule {
 467         /** link chain on the_lnet.ln_delay_rules */
 468         struct list_head        dl_link;
 469         /** link chain on delay_dd.dd_sched_rules */
 470         struct list_head        dl_sched_link;
 471         /** attributes of this rule */
 472         struct lnet_fault_attr  dl_attr;
 473         /** lock to protect \a below members */
 474         spinlock_t              dl_lock;
 475         /** refcount of delay rule */
 476         atomic_t                dl_refcount;
 477         /**
 478          * the message sequence to delay, which means message is delayed when
 479          * dl_stat.fs_count == dl_delay_at
 480          */
 481         unsigned long           dl_delay_at;
 482         /**
 483          * seconds to delay the next message, it's exclusive with dl_delay_at
 484          */
 485         time64_t                dl_delay_time;
 486         /** baseline to caculate dl_delay_time */
 487         time64_t                dl_time_base;
 488         /** seconds until we send the next delayed message */
 489         time64_t                dl_msg_send;
 490         /** delayed message list */
 491         struct list_head        dl_msg_list;
 492         /** statistic of delayed messages */
 493         struct lnet_fault_stat  dl_stat;
 494         /** timer to wakeup delay_daemon */
 495         struct timer_list       dl_timer;
 496 };
 497
 498 struct delay_daemon_data {
 499         /** serialise rule add/remove */
 500         struct mutex            dd_mutex;
 501         /** protect rules on \a dd_sched_rules */
 502         spinlock_t              dd_lock;
 503         /** scheduled delay rules (by timer) */
 504         struct list_head        dd_sched_rules;
 505         /** deamon thread sleeps at here */
 506         wait_queue_head_t       dd_waitq;
 507         /** controler (lctl command) wait at here */
 508         wait_queue_head_t       dd_ctl_waitq;
 509         /** deamon is running */
 510         unsigned int            dd_running;
 511         /** deamon stopped */
 512         unsigned int            dd_stopped;
 513 };
 514
 515 static struct delay_daemon_data delay_dd;
 516
 517 static void
 518 delay_rule_decref(struct lnet_delay_rule *rule)
 519 {
 520         if (atomic_dec_and_test(&rule->dl_refcount)) {
 521                 LASSERT(list_empty(&rule->dl_sched_link));
 522                 LASSERT(list_empty(&rule->dl_msg_list));
 523                 LASSERT(list_empty(&rule->dl_link));
 524
 525                 CFS_FREE_PTR(rule);
 526         }
 527 }
 528
 529 /**
 530  * check source/destination NID, portal, message type and delay rate,
 531  * decide whether should delay this message or not
 532  */
 533 static bool
 534 delay_rule_match(struct lnet_delay_rule *rule, lnet_nid_t src,
 535                 lnet_nid_t dst, unsigned int type, unsigned int portal,
 536                 struct lnet_msg *msg)
 537 {
 538         struct lnet_fault_attr  *attr = &rule->dl_attr;
 539         bool                     delay;
 540
 541         if (!lnet_fault_attr_match(attr, src, LNET_NID_ANY,
 542                                    dst, type, portal))
 543                 return false;
 544
 545         /* match this rule, check delay rate now */
 546         spin_lock(&rule->dl_lock);
 547         if (rule->dl_delay_time != 0) { /* time based delay */
 548                 time64_t now = ktime_get_seconds();
 549
 550                 rule->dl_stat.fs_count++;
 551                 delay = now >= rule->dl_delay_time;
 552                 if (delay) {
 553                         if (now > rule->dl_time_base)
 554                                 rule->dl_time_base = now;
 555
 556                         rule->dl_delay_time = rule->dl_time_base +
 557                                               prandom_u32_max(attr->u.delay.la_interval);
 558                         rule->dl_time_base += attr->u.delay.la_interval;
 559
 560                         CDEBUG(D_NET, "Delay Rule %s->%s: next delay : %lld\n",
 561                                libcfs_nid2str(attr->fa_src),
 562                                libcfs_nid2str(attr->fa_dst),
 563                                rule->dl_delay_time);
 564                 }
 565
 566         } else { /* rate based delay */
 567                 __u64 count;
 568
 569                 delay = rule->dl_stat.fs_count++ == rule->dl_delay_at;
 570                 /* generate the next random rate sequence */
 571                 count = rule->dl_stat.fs_count;
 572                 if (do_div(count, attr->u.delay.la_rate) == 0) {
 573                         rule->dl_delay_at = rule->dl_stat.fs_count +
 574                                             prandom_u32_max(attr->u.delay.la_rate);
 575                         CDEBUG(D_NET, "Delay Rule %s->%s: next delay: %lu\n",
 576                                libcfs_nid2str(attr->fa_src),
 577                                libcfs_nid2str(attr->fa_dst), rule->dl_delay_at);
 578                 }
 579         }
 580
 581         if (!delay) {
 582                 spin_unlock(&rule->dl_lock);
 583                 return false;
 584         }
 585
 586         /* delay this message, update counters */
 587         lnet_fault_stat_inc(&rule->dl_stat, type);
 588         rule->dl_stat.u.delay.ls_delayed++;
 589
 590         list_add_tail(&msg->msg_list, &rule->dl_msg_list);
 591         msg->msg_delay_send = ktime_get_seconds() + attr->u.delay.la_latency;
 592         if (rule->dl_msg_send == -1) {
 593                 rule->dl_msg_send = msg->msg_delay_send;
 594                 mod_timer(&rule->dl_timer,
 595                           jiffies + cfs_time_seconds(rule->dl_msg_send));
 596         }
 597
 598         spin_unlock(&rule->dl_lock);
 599         return true;
 600 }
 601
 602 /**
 603  * check if \a msg can match any Delay Rule, receiving of this message
 604  * will be delayed if there is a match.
 605  */
 606 bool
 607 lnet_delay_rule_match_locked(struct lnet_hdr *hdr, struct lnet_msg *msg)
 608 {
 609         struct lnet_delay_rule  *rule;
 610         lnet_nid_t               src = le64_to_cpu(hdr->src_nid);
 611         lnet_nid_t               dst = le64_to_cpu(hdr->dest_nid);
 612         unsigned int             typ = le32_to_cpu(hdr->type);
 613         unsigned int             ptl = -1;
 614
 615         /* NB: called with hold of lnet_net_lock */
 616
 617         /* NB: if Portal is specified, then only PUT and GET will be
 618          * filtered by delay rule */
 619         if (typ == LNET_MSG_PUT)
 620                 ptl = le32_to_cpu(hdr->msg.put.ptl_index);
 621         else if (typ == LNET_MSG_GET)
 622                 ptl = le32_to_cpu(hdr->msg.get.ptl_index);
 623
 624         list_for_each_entry(rule, &the_lnet.ln_delay_rules, dl_link) {
 625                 if (delay_rule_match(rule, src, dst, typ, ptl, msg))
 626                         return true;
 627         }
 628
 629         return false;
 630 }
 631
 632 /** check out delayed messages for send */
 633 static void
 634 delayed_msg_check(struct lnet_delay_rule *rule, bool all,
 635                   struct list_head *msg_list)
 636 {
 637         struct lnet_msg *msg;
 638         struct lnet_msg *tmp;
 639         time64_t now = ktime_get_seconds();
 640
 641         if (!all && cfs_time_seconds(rule->dl_msg_send) > now)
 642                 return;
 643
 644         spin_lock(&rule->dl_lock);
 645         list_for_each_entry_safe(msg, tmp, &rule->dl_msg_list, msg_list) {
 646                 if (!all && msg->msg_delay_send > now)
 647                         break;
 648
 649                 msg->msg_delay_send = 0;
 650                 list_move_tail(&msg->msg_list, msg_list);
 651         }
 652
 653         if (list_empty(&rule->dl_msg_list)) {
 654                 del_timer(&rule->dl_timer);
 655                 rule->dl_msg_send = -1;
 656
 657         } else if (!list_empty(msg_list)) {
 658                 /* dequeued some timedout messages, update timer for the
 659                  * next delayed message on rule */
 660                 msg = list_entry(rule->dl_msg_list.next,
 661                                  struct lnet_msg, msg_list);
 662                 rule->dl_msg_send = msg->msg_delay_send;
 663                 mod_timer(&rule->dl_timer,
 664                           jiffies + cfs_time_seconds(rule->dl_msg_send));
 665         }
 666         spin_unlock(&rule->dl_lock);
 667 }
 668
 669 static void
 670 delayed_msg_process(struct list_head *msg_list, bool drop)
 671 {
 672         struct lnet_msg *msg;
 673
 674         while (!list_empty(msg_list)) {
 675                 struct lnet_ni *ni;
 676                 int             cpt;
 677                 int             rc;
 678
 679                 msg = list_entry(msg_list->next, struct lnet_msg, msg_list);
 680                 LASSERT(msg->msg_rxpeer != NULL);
 681                 LASSERT(msg->msg_rxni != NULL);
 682
 683                 ni = msg->msg_rxni;
 684                 cpt = msg->msg_rx_cpt;
 685
 686                 list_del_init(&msg->msg_list);
 687                 if (drop) {
 688                         rc = -ECANCELED;
 689
 690                 } else if (!msg->msg_routing) {
 691                         rc = lnet_parse_local(ni, msg);
 692                         if (rc == 0)
 693                                 continue;
 694
 695                 } else {
 696                         lnet_net_lock(cpt);
 697                         rc = lnet_parse_forward_locked(ni, msg);
 698                         lnet_net_unlock(cpt);
 699
 700                         switch (rc) {
 701                         case LNET_CREDIT_OK:
 702                                 lnet_ni_recv(ni, msg->msg_private, msg, 0,
 703                                              0, msg->msg_len, msg->msg_len);
 704                         case LNET_CREDIT_WAIT:
 705                                 continue;
 706                         default: /* failures */
 707                                 break;
 708                         }
 709                 }
 710
 711                 lnet_drop_message(ni, cpt, msg->msg_private, msg->msg_len,
 712                                   msg->msg_type);
 713                 lnet_finalize(msg, rc);
 714         }
 715 }
 716
 717 /**
 718  * Process delayed messages for scheduled rules
 719  * This function can either be called by delay_rule_daemon, or by lnet_finalise
 720  */
 721 void
 722 lnet_delay_rule_check(void)
 723 {
 724         struct lnet_delay_rule *rule;
 725         LIST_HEAD(msgs);
 726
 727         while (1) {
 728                 if (list_empty(&delay_dd.dd_sched_rules))
 729                         break;
 730
 731                 spin_lock_bh(&delay_dd.dd_lock);
 732                 if (list_empty(&delay_dd.dd_sched_rules)) {
 733                         spin_unlock_bh(&delay_dd.dd_lock);
 734                         break;
 735                 }
 736
 737                 rule = list_entry(delay_dd.dd_sched_rules.next,
 738                                   struct lnet_delay_rule, dl_sched_link);
 739                 list_del_init(&rule->dl_sched_link);
 740                 spin_unlock_bh(&delay_dd.dd_lock);
 741
 742                 delayed_msg_check(rule, false, &msgs);
 743                 delay_rule_decref(rule); /* -1 for delay_dd.dd_sched_rules */
 744         }
 745
 746         if (!list_empty(&msgs))
 747                 delayed_msg_process(&msgs, false);
 748 }
 749
 750 /** deamon thread to handle delayed messages */
 751 static int
 752 lnet_delay_rule_daemon(void *arg)
 753 {
 754         delay_dd.dd_running = 1;
 755         wake_up(&delay_dd.dd_ctl_waitq);
 756
 757         while (delay_dd.dd_running) {
 758                 wait_event_interruptible(delay_dd.dd_waitq,
 759                                          !delay_dd.dd_running ||
 760                                          !list_empty(&delay_dd.dd_sched_rules));
 761                 lnet_delay_rule_check();
 762         }
 763
 764         /* in case more rules have been enqueued after my last check */
 765         lnet_delay_rule_check();
 766         delay_dd.dd_stopped = 1;
 767         wake_up(&delay_dd.dd_ctl_waitq);
 768
 769         return 0;
 770 }
 771
 772 static void
 773 delay_timer_cb(cfs_timer_cb_arg_t data)
 774 {
 775         struct lnet_delay_rule *rule = cfs_from_timer(rule, data, dl_timer);
 776
 777         spin_lock_bh(&delay_dd.dd_lock);
 778         if (list_empty(&rule->dl_sched_link) && delay_dd.dd_running) {
 779                 atomic_inc(&rule->dl_refcount);
 780                 list_add_tail(&rule->dl_sched_link, &delay_dd.dd_sched_rules);
 781                 wake_up(&delay_dd.dd_waitq);
 782         }
 783         spin_unlock_bh(&delay_dd.dd_lock);
 784 }
 785
 786 /**
 787  * Add a new delay rule to LNet
 788  * There is no check for duplicated delay rule, all rules will be checked for
 789  * incoming message.
 790  */
 791 int
 792 lnet_delay_rule_add(struct lnet_fault_attr *attr)
 793 {
 794         struct lnet_delay_rule *rule;
 795         int                     rc = 0;
 796         ENTRY;
 797
 798         if (!((attr->u.delay.la_rate == 0) ^
 799               (attr->u.delay.la_interval == 0))) {
 800                 CDEBUG(D_NET,
 801                        "please provide either delay rate or delay interval, "
 802                        "but not both at the same time %d/%d\n",
 803                        attr->u.delay.la_rate, attr->u.delay.la_interval);
 804                 RETURN(-EINVAL);
 805         }
 806
 807         if (attr->u.delay.la_latency == 0) {
 808                 CDEBUG(D_NET, "delay latency cannot be zero\n");
 809                 RETURN(-EINVAL);
 810         }
 811
 812         if (lnet_fault_attr_validate(attr) != 0)
 813                 RETURN(-EINVAL);
 814
 815         CFS_ALLOC_PTR(rule);
 816         if (rule == NULL)
 817                 RETURN(-ENOMEM);
 818
 819         mutex_lock(&delay_dd.dd_mutex);
 820         if (!delay_dd.dd_running) {
 821                 struct task_struct *task;
 822
 823                 /* NB: although LND threads will process delayed message
 824                  * in lnet_finalize, but there is no guarantee that LND
 825                  * threads will be waken up if no other message needs to
 826                  * be handled.
 827                  * Only one daemon thread, performance is not the concern
 828                  * of this simualation module.
 829                  */
 830                 task = kthread_run(lnet_delay_rule_daemon, NULL, "lnet_dd");
 831                 if (IS_ERR(task)) {
 832                         rc = PTR_ERR(task);
 833                         GOTO(failed, rc);
 834                 }
 835                 wait_event(delay_dd.dd_ctl_waitq, delay_dd.dd_running);
 836         }
 837
 838         cfs_timer_setup(&rule->dl_timer, delay_timer_cb,
 839                         (unsigned long)rule, 0);
 840
 841         spin_lock_init(&rule->dl_lock);
 842         INIT_LIST_HEAD(&rule->dl_msg_list);
 843         INIT_LIST_HEAD(&rule->dl_sched_link);
 844
 845         rule->dl_attr = *attr;
 846         if (attr->u.delay.la_interval != 0) {
 847                 rule->dl_time_base = ktime_get_seconds() +
 848                                      attr->u.delay.la_interval;
 849                 rule->dl_delay_time = ktime_get_seconds() +
 850                                       prandom_u32_max(attr->u.delay.la_interval);
 851         } else {
 852                 rule->dl_delay_at = prandom_u32_max(attr->u.delay.la_rate);
 853         }
 854
 855         rule->dl_msg_send = -1;
 856
 857         lnet_net_lock(LNET_LOCK_EX);
 858         atomic_set(&rule->dl_refcount, 1);
 859         list_add(&rule->dl_link, &the_lnet.ln_delay_rules);
 860         lnet_net_unlock(LNET_LOCK_EX);
 861
 862         CDEBUG(D_NET, "Added delay rule: src %s, dst %s, rate %d\n",
 863                libcfs_nid2str(attr->fa_src), libcfs_nid2str(attr->fa_src),
 864                attr->u.delay.la_rate);
 865
 866         mutex_unlock(&delay_dd.dd_mutex);
 867         RETURN(0);
 868  failed:
 869         mutex_unlock(&delay_dd.dd_mutex);
 870         CFS_FREE_PTR(rule);
 871         return rc;
 872 }
 873
 874 /**
 875  * Remove matched Delay Rules from lnet, if \a shutdown is true or both \a src
 876  * and \a dst are zero, all rules will be removed, otherwise only matched rules
 877  * will be removed.
 878  * If \a src is zero, then all rules have \a dst as destination will be remove
 879  * If \a dst is zero, then all rules have \a src as source will be removed
 880  *
 881  * When a delay rule is removed, all delayed messages of this rule will be
 882  * processed immediately.
 883  */
 884 int
 885 lnet_delay_rule_del(lnet_nid_t src, lnet_nid_t dst, bool shutdown)
 886 {
 887         struct lnet_delay_rule *rule;
 888         struct lnet_delay_rule *tmp;
 889         LIST_HEAD(rule_list);
 890         LIST_HEAD(msg_list);
 891         int n = 0;
 892         bool cleanup;
 893         ENTRY;
 894
 895         if (shutdown)
 896                 src = dst = 0;
 897
 898         mutex_lock(&delay_dd.dd_mutex);
 899         lnet_net_lock(LNET_LOCK_EX);
 900
 901         list_for_each_entry_safe(rule, tmp, &the_lnet.ln_delay_rules, dl_link) {
 902                 if (rule->dl_attr.fa_src != src && src != 0)
 903                         continue;
 904
 905                 if (rule->dl_attr.fa_dst != dst && dst != 0)
 906                         continue;
 907
 908                 CDEBUG(D_NET, "Remove delay rule: src %s->dst: %s (1/%d, %d)\n",
 909                        libcfs_nid2str(rule->dl_attr.fa_src),
 910                        libcfs_nid2str(rule->dl_attr.fa_dst),
 911                        rule->dl_attr.u.delay.la_rate,
 912                        rule->dl_attr.u.delay.la_interval);
 913                 /* refcount is taken over by rule_list */
 914                 list_move(&rule->dl_link, &rule_list);
 915         }
 916
 917         /* check if we need to shutdown delay_daemon */
 918         cleanup = list_empty(&the_lnet.ln_delay_rules) &&
 919                   !list_empty(&rule_list);
 920         lnet_net_unlock(LNET_LOCK_EX);
 921
 922         list_for_each_entry_safe(rule, tmp, &rule_list, dl_link) {
 923                 list_del_init(&rule->dl_link);
 924
 925                 del_timer_sync(&rule->dl_timer);
 926                 delayed_msg_check(rule, true, &msg_list);
 927                 delay_rule_decref(rule); /* -1 for the_lnet.ln_delay_rules */
 928                 n++;
 929         }
 930
 931         if (cleanup) { /* no more delay rule, shutdown delay_daemon */
 932                 LASSERT(delay_dd.dd_running);
 933                 delay_dd.dd_running = 0;
 934                 wake_up(&delay_dd.dd_waitq);
 935
 936                 while (!delay_dd.dd_stopped)
 937                         wait_event(delay_dd.dd_ctl_waitq, delay_dd.dd_stopped);
 938         }
 939         mutex_unlock(&delay_dd.dd_mutex);
 940
 941         if (!list_empty(&msg_list))
 942                 delayed_msg_process(&msg_list, shutdown);
 943
 944         RETURN(n);
 945 }
 946
 947 /**
 948  * List Delay Rule at position of \a pos
 949  */
 950 int
 951 lnet_delay_rule_list(int pos, struct lnet_fault_attr *attr,
 952                     struct lnet_fault_stat *stat)
 953 {
 954         struct lnet_delay_rule *rule;
 955         int                     cpt;
 956         int                     i = 0;
 957         int                     rc = -ENOENT;
 958         ENTRY;
 959
 960         cpt = lnet_net_lock_current();
 961         list_for_each_entry(rule, &the_lnet.ln_delay_rules, dl_link) {
 962                 if (i++ < pos)
 963                         continue;
 964
 965                 spin_lock(&rule->dl_lock);
 966                 *attr = rule->dl_attr;
 967                 *stat = rule->dl_stat;
 968                 spin_unlock(&rule->dl_lock);
 969                 rc = 0;
 970                 break;
 971         }
 972
 973         lnet_net_unlock(cpt);
 974         RETURN(rc);
 975 }
 976
 977 /**
 978  * reset counters for all Delay Rules
 979  */
 980 void
 981 lnet_delay_rule_reset(void)
 982 {
 983         struct lnet_delay_rule *rule;
 984         int                     cpt;
 985         ENTRY;
 986
 987         cpt = lnet_net_lock_current();
 988
 989         list_for_each_entry(rule, &the_lnet.ln_delay_rules, dl_link) {
 990                 struct lnet_fault_attr *attr = &rule->dl_attr;
 991
 992                 spin_lock(&rule->dl_lock);
 993
 994                 memset(&rule->dl_stat, 0, sizeof(rule->dl_stat));
 995                 if (attr->u.delay.la_rate != 0) {
 996                         rule->dl_delay_at = prandom_u32_max(attr->u.delay.la_rate);
 997                 } else {
 998                         rule->dl_delay_time = ktime_get_seconds() +
 999                                               prandom_u32_max(attr->u.delay.la_interval);
1000                         rule->dl_time_base = ktime_get_seconds() +
1001                                              attr->u.delay.la_interval;
1002                 }
1003                 spin_unlock(&rule->dl_lock);
1004         }
1005
1006         lnet_net_unlock(cpt);
1007         EXIT;
1008 }
1009
1010 int
1011 lnet_fault_ctl(int opc, struct libcfs_ioctl_data *data)
1012 {
1013         struct lnet_fault_attr *attr;
1014         struct lnet_fault_stat *stat;
1015
1016         attr = (struct lnet_fault_attr *)data->ioc_inlbuf1;
1017
1018         switch (opc) {
1019         default:
1020                 return -EINVAL;
1021
1022         case LNET_CTL_DROP_ADD:
1023                 if (attr == NULL)
1024                         return -EINVAL;
1025
1026                 return lnet_drop_rule_add(attr);
1027
1028         case LNET_CTL_DROP_DEL:
1029                 if (attr == NULL)
1030                         return -EINVAL;
1031
1032                 data->ioc_count = lnet_drop_rule_del(attr->fa_src,
1033                                                      attr->fa_dst);
1034                 return 0;
1035
1036         case LNET_CTL_DROP_RESET:
1037                 lnet_drop_rule_reset();
1038                 return 0;
1039
1040         case LNET_CTL_DROP_LIST:
1041                 stat = (struct lnet_fault_stat *)data->ioc_inlbuf2;
1042                 if (attr == NULL || stat == NULL)
1043                         return -EINVAL;
1044
1045                 return lnet_drop_rule_list(data->ioc_count, attr, stat);
1046
1047         case LNET_CTL_DELAY_ADD:
1048                 if (attr == NULL)
1049                         return -EINVAL;
1050
1051                 return lnet_delay_rule_add(attr);
1052
1053         case LNET_CTL_DELAY_DEL:
1054                 if (attr == NULL)
1055                         return -EINVAL;
1056
1057                 data->ioc_count = lnet_delay_rule_del(attr->fa_src,
1058                                                       attr->fa_dst, false);
1059                 return 0;
1060
1061         case LNET_CTL_DELAY_RESET:
1062                 lnet_delay_rule_reset();
1063                 return 0;
1064
1065         case LNET_CTL_DELAY_LIST:
1066                 stat = (struct lnet_fault_stat *)data->ioc_inlbuf2;
1067                 if (attr == NULL || stat == NULL)
1068                         return -EINVAL;
1069
1070                 return lnet_delay_rule_list(data->ioc_count, attr, stat);
1071         }
1072 }
1073
1074 int
1075 lnet_fault_init(void)
1076 {
1077         BUILD_BUG_ON(LNET_PUT_BIT != 1 << LNET_MSG_PUT);
1078         BUILD_BUG_ON(LNET_ACK_BIT != 1 << LNET_MSG_ACK);
1079         BUILD_BUG_ON(LNET_GET_BIT != 1 << LNET_MSG_GET);
1080         BUILD_BUG_ON(LNET_REPLY_BIT != 1 << LNET_MSG_REPLY);
1081
1082         mutex_init(&delay_dd.dd_mutex);
1083         spin_lock_init(&delay_dd.dd_lock);
1084         init_waitqueue_head(&delay_dd.dd_waitq);
1085         init_waitqueue_head(&delay_dd.dd_ctl_waitq);
1086         INIT_LIST_HEAD(&delay_dd.dd_sched_rules);
1087
1088         return 0;
1089 }
1090
1091 void
1092 lnet_fault_fini(void)
1093 {
1094         lnet_drop_rule_del(0, 0);
1095         lnet_delay_rule_del(0, 0, true);
1096
1097         LASSERT(list_empty(&the_lnet.ln_drop_rules));
1098         LASSERT(list_empty(&the_lnet.ln_delay_rules));
1099         LASSERT(list_empty(&delay_dd.dd_sched_rules));
1100 }