multipathd/main.c

   1 #include <string.h>
   2 #include <pthread.h>
   3 #include <stdio.h>
   4 #include <unistd.h>
   5 #include <linux/unistd.h>
   6 #include <stdlib.h>
   7 #include <sys/types.h>
   8 #include <sys/stat.h>
   9 #include <fcntl.h>
  10 #include <libdevmapper.h>
  11 #include <signal.h>
  12 #include <wait.h>
  13 #include <sched.h>
  14 #include <errno.h>
  15 #include <sys/mount.h>
  16 #include <sys/mman.h>
  17
  18 /*
  19  * libsysfs
  20  */
  21 #include <sysfs/libsysfs.h>
  22 #include <sysfs/dlist.h>
  23
  24 /*
  25  * libcheckers
  26  */
  27 #include <checkers.h>
  28 #include <path_state.h>
  29
  30 /*
  31  * libmultipath
  32  */
  33 #include <parser.h>
  34 #include <vector.h>
  35 #include <memory.h>
  36 #include <config.h>
  37 #include <callout.h>
  38 #include <util.h>
  39 #include <blacklist.h>
  40 #include <hwtable.h>
  41 #include <defaults.h>
  42 #include <structs.h>
  43 #include <dmparser.h>
  44 #include <devmapper.h>
  45 #include <dict.h>
  46 #include <discovery.h>
  47 #include <debug.h>
  48 #include <propsel.h>
  49 #include <uevent.h>
  50 #include <switchgroup.h>
  51 #include <path_state.h>
  52
  53 #include "main.h"
  54 #include "copy.h"
  55 #include "pidfile.h"
  56 #include "uxlsnr.h"
  57 #include "uxclnt.h"
  58 #include "cli.h"
  59 #include "cli_handlers.h"
  60
  61 #define FILE_NAME_SIZE 256
  62 #define CMDSIZE 160
  63
  64 #define LOG_MSG(a,b) \
  65         if (strlen(b)) { \
  66                 condlog(a, "%s: %s", pp->dev_t, b); \
  67                 memset(b, 0, MAX_CHECKER_MSG_SIZE); \
  68         }
  69
  70 #ifdef LCKDBG
  71 #define lock(a) \
  72         fprintf(stderr, "%s:%s(%i) lock %p\n", __FILE__, __FUNCTION__, __LINE__, a); \
  73         pthread_mutex_lock(a)
  74 #define unlock(a) \
  75         fprintf(stderr, "%s:%s(%i) unlock %p\n", __FILE__, __FUNCTION__, __LINE__, a); \
  76         pthread_mutex_unlock(a)
  77 #else
  78 #define lock(a) pthread_mutex_lock(a)
  79 #define unlock(a) pthread_mutex_unlock(a)
  80 #endif
  81
  82 pthread_cond_t exit_cond = PTHREAD_COND_INITIALIZER;
  83 pthread_mutex_t exit_mutex = PTHREAD_MUTEX_INITIALIZER;
  84
  85 /*
  86  * structs
  87  */
  88 struct event_thread {
  89         struct dm_task *dmt;
  90         pthread_t thread;
  91         int event_nr;
  92         char mapname[WWID_SIZE];
  93         struct paths *allpaths;
  94 };
  95
  96 static struct event_thread *
  97 alloc_waiter (void)
  98 {
  99
 100         struct event_thread * wp;
 101
 102         wp = (struct event_thread *)MALLOC(sizeof(struct event_thread));
 103
 104         return wp;
 105 }
 106
 107 static void
 108 cleanup_lock (void * data)
 109 {
 110         unlock((pthread_mutex_t *)data);
 111 }
 112
 113 static void
 114 set_paths_owner (struct paths * allpaths, struct multipath * mpp)
 115 {
 116         int i;
 117         struct path * pp;
 118
 119         if (!mpp)
 120                 return;
 121
 122         vector_foreach_slot (allpaths->pathvec, pp, i) {
 123                 if (!strncmp(mpp->wwid, pp->wwid, WWID_SIZE)) {
 124                         condlog(4, "%s ownership set", pp->dev_t);
 125                         pp->mpp = mpp;
 126                 }
 127         }
 128 }
 129
 130 static void
 131 unset_paths_owner (struct paths * allpaths, struct multipath * mpp)
 132 {
 133         int i;
 134         struct path * pp;
 135
 136         vector_foreach_slot (allpaths->pathvec, pp, i) {
 137                 if (pp->mpp == mpp) {
 138                         condlog(4, "%s is orphaned", pp->dev_t);
 139                         pp->mpp = NULL;
 140                 }
 141         }
 142 }
 143
 144 static int
 145 update_multipath_table (struct multipath *mpp, vector pathvec)
 146 {
 147         if (!mpp)
 148                 return 1;
 149
 150         if (dm_get_map(mpp->alias, &mpp->size, mpp->params))
 151                 return 1;
 152
 153         if (disassemble_map(pathvec, mpp->params, mpp))
 154                 return 1;
 155
 156         return 0;
 157 }
 158
 159 static int
 160 update_multipath_status (struct multipath *mpp)
 161 {
 162         if (!mpp)
 163                 return 1;
 164
 165         if(dm_get_status(mpp->alias, mpp->status))
 166                 return 1;
 167
 168         if (disassemble_status(mpp->status, mpp))
 169                 return 1;
 170
 171         return 0;
 172 }
 173
 174 static int
 175 update_multipath_strings (struct multipath *mpp, vector pathvec)
 176 {
 177         if (mpp->selector) {
 178                 FREE(mpp->selector);
 179                 mpp->selector = NULL;
 180         }
 181
 182         if (mpp->features) {
 183                 FREE(mpp->features);
 184                 mpp->features = NULL;
 185         }
 186
 187         if (mpp->hwhandler) {
 188                 FREE(mpp->hwhandler);
 189                 mpp->hwhandler = NULL;
 190         }
 191
 192         free_pgvec(mpp->pg, KEEP_PATHS);
 193         mpp->pg = NULL;
 194
 195         if (update_multipath_table(mpp, pathvec))
 196                 return 1;
 197
 198         if (update_multipath_status(mpp))
 199                 return 1;
 200
 201         return 0;
 202 }
 203
 204 static int
 205 setup_multipath (struct paths * allpaths, struct multipath * mpp)
 206 {
 207         char * wwid;
 208         int i;
 209
 210         wwid = get_mpe_wwid(mpp->alias);
 211
 212         if (wwid) {
 213                 strncpy(mpp->wwid, wwid, WWID_SIZE);
 214                 wwid = NULL;
 215         } else
 216                 strncpy(mpp->wwid, mpp->alias, WWID_SIZE);
 217
 218         condlog(4, "discovered map %s", mpp->alias);
 219
 220         if (update_multipath_strings(mpp, allpaths->pathvec))
 221                 goto out;
 222
 223         set_paths_owner(allpaths, mpp);
 224         mpp->mpe = find_mpe(mpp->wwid);
 225         select_pgfailback(mpp);
 226
 227         return 0;
 228 out:
 229         /*
 230          * purge the multipath vector
 231          */
 232         if ((i = find_slot(allpaths->mpvec, (void *)mpp)) != -1)
 233                 vector_del_slot(allpaths->mpvec, i);
 234
 235         free_multipath(mpp, KEEP_PATHS);
 236         condlog(0, "failed to setup multipath");
 237         return 1;
 238 }
 239
 240 static void
 241 switch_pathgroup (struct multipath * mpp)
 242 {
 243         struct pathgroup * pgp;
 244         struct path * pp;
 245         int i, j;
 246
 247         if (!mpp || mpp->pgfailback == FAILBACK_MANUAL)
 248                 return;
 249         /*
 250          * Refresh path priority values
 251          */
 252         vector_foreach_slot (mpp->pg, pgp, i)
 253                 vector_foreach_slot (pgp->paths, pp, j)
 254                         pathinfo(pp, conf->hwtable, DI_PRIO);
 255
 256         select_path_group(mpp); /* sets mpp->nextpg */
 257         pgp = VECTOR_SLOT(mpp->pg, mpp->nextpg - 1);
 258
 259         if (pgp && pgp->status != PGSTATE_ACTIVE) {
 260                 dm_switchgroup(mpp->alias, mpp->nextpg);
 261                 condlog(2, "%s: switch to path group #%i",
 262                          mpp->alias, mpp->nextpg);
 263         }
 264 }
 265
 266 static int
 267 update_multipath (struct paths *allpaths, char *mapname)
 268 {
 269         struct multipath *mpp;
 270         struct pathgroup  *pgp;
 271         struct path *pp;
 272         int i, j;
 273         int r = 1;
 274
 275         mpp = find_mp(allpaths->mpvec, mapname);
 276
 277         if (!mpp)
 278                 goto out;
 279
 280         free_pgvec(mpp->pg, KEEP_PATHS);
 281         mpp->pg = NULL;
 282
 283         if (setup_multipath(allpaths, mpp))
 284                 goto out; /* mpp freed in setup_multipath */
 285
 286         /*
 287          * compare checkers states with DM states
 288          */
 289         vector_foreach_slot (mpp->pg, pgp, i) {
 290                 vector_foreach_slot (pgp->paths, pp, j) {
 291                         if (pp->dmstate != PSTATE_FAILED)
 292                                 continue;
 293
 294                         if (pp->state != PATH_DOWN) {
 295                                 condlog(2, "%s: mark as failed", pp->dev_t);
 296                                 pp->state = PATH_DOWN;
 297
 298                                 /*
 299                                  * if opportune,
 300                                  * schedule the next check earlier
 301                                  */
 302                                 if (pp->tick > conf->checkint)
 303                                         pp->tick = conf->checkint;
 304                         }
 305                 }
 306         }
 307         r = 0;
 308 out:
 309         if (r)
 310                 condlog(0, "failed to update multipath");
 311
 312         return r;
 313 }
 314
 315 static void
 316 free_waiter (void * data)
 317 {
 318         struct event_thread * wp = (struct event_thread *)data;
 319
 320         if (wp->dmt)
 321                 dm_task_destroy(wp->dmt);
 322         FREE(wp);
 323 }
 324
 325 static sigset_t unblock_sigusr1(void)
 326 {
 327         sigset_t set, old;
 328
 329         sigemptyset(&set);
 330         sigaddset(&set, SIGUSR1);
 331         pthread_sigmask(SIG_UNBLOCK, &set, &old);
 332         return old;
 333 }
 334
 335 /*
 336  * returns the reschedule delay
 337  * negative means *stop*
 338  */
 339 static int
 340 waiteventloop (struct event_thread * waiter)
 341 {
 342         sigset_t set;
 343         int event_nr;
 344         int r;
 345
 346         if (!waiter->event_nr)
 347                 waiter->event_nr = dm_geteventnr(waiter->mapname);
 348
 349         if (!(waiter->dmt = dm_task_create(DM_DEVICE_WAITEVENT)))
 350                 return 1;
 351
 352         if (!dm_task_set_name(waiter->dmt, waiter->mapname))
 353                 return 1;
 354
 355         if (waiter->event_nr && !dm_task_set_event_nr(waiter->dmt,
 356                                                       waiter->event_nr))
 357                 return 1;
 358
 359         dm_task_no_open_count(waiter->dmt);
 360
 361         set = unblock_sigusr1();
 362         dm_task_run(waiter->dmt);
 363         pthread_sigmask(SIG_SETMASK, &set, NULL);
 364         pthread_testcancel();
 365         dm_task_destroy(waiter->dmt);
 366         waiter->dmt = NULL;
 367
 368         waiter->event_nr++;
 369
 370         /*
 371          * upon event ...
 372          */
 373         while (1) {
 374                 condlog(2, "devmap event (%i) on %s",
 375                                 waiter->event_nr, waiter->mapname);
 376
 377                 /*
 378                  * event might be :
 379                  *
 380                  * 1) a table reload, which means our mpp structure is
 381                  *    obsolete : refresh it through update_multipath()
 382                  * 2) a path failed by DM : mark as such through
 383                  *    update_multipath()
 384                  * 3) map has gone away : stop the thread.
 385                  * 4) a path reinstate : nothing to do
 386                  * 5) a switch group : nothing to do
 387                  */
 388                 pthread_cleanup_push(cleanup_lock, waiter->allpaths->lock);
 389                 lock(waiter->allpaths->lock);
 390
 391                 r = update_multipath(waiter->allpaths, waiter->mapname);
 392                 pthread_cleanup_pop(1);
 393
 394                 if (r)
 395                         return -1; /* stop the thread */
 396
 397                 event_nr = dm_geteventnr(waiter->mapname);
 398
 399                 if (waiter->event_nr == event_nr)
 400                         return 1; /* upon problem reschedule 1s later */
 401
 402                 waiter->event_nr = event_nr;
 403         }
 404         return -1; /* never reach there */
 405 }
 406
 407 static void *
 408 waitevent (void * et)
 409 {
 410         int r;
 411         struct event_thread *waiter;
 412
 413         mlockall(MCL_CURRENT | MCL_FUTURE);
 414
 415         waiter = (struct event_thread *)et;
 416         pthread_cleanup_push(free_waiter, et);
 417
 418         while (1) {
 419                 r = waiteventloop(waiter);
 420
 421                 if (r < 0)
 422                         break;
 423
 424                 pthread_testcancel();
 425                 sleep(r);
 426                 pthread_testcancel();
 427         }
 428
 429         pthread_cleanup_pop(1);
 430         return NULL;
 431 }
 432
 433 static int
 434 stop_waiter_thread (struct multipath * mpp, struct paths * allpaths)
 435 {
 436         struct event_thread * wp = (struct event_thread *)mpp->waiter;
 437         pthread_t thread = wp->thread;
 438         int r;
 439
 440         if (!wp)
 441                 return 1;
 442
 443         condlog(2, "%s: reap event checker", wp->mapname);
 444
 445         if ((r = pthread_cancel(thread)))
 446                 return r;
 447
 448         pthread_kill(thread, SIGUSR1);
 449         return 0;
 450 }
 451
 452 static int
 453 start_waiter_thread (struct multipath * mpp, struct paths * allpaths)
 454 {
 455         pthread_attr_t attr;
 456         struct event_thread * wp;
 457
 458         if (!mpp)
 459                 return 0;
 460
 461         if (pthread_attr_init(&attr))
 462                 goto out;
 463
 464         pthread_attr_setstacksize(&attr, 32 * 1024);
 465         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
 466
 467         wp = alloc_waiter();
 468
 469         if (!wp)
 470                 goto out;
 471
 472         mpp->waiter = (void *)wp;
 473         strncpy(wp->mapname, mpp->alias, WWID_SIZE);
 474         wp->allpaths = allpaths;
 475
 476         if (pthread_create(&wp->thread, &attr, waitevent, wp)) {
 477                 condlog(0, "%s: cannot create event checker", wp->mapname);
 478                 goto out1;
 479         }
 480         condlog(2, "%s: event checker started", wp->mapname);
 481
 482         return 0;
 483 out1:
 484         free_waiter(wp);
 485         mpp->waiter = NULL;
 486 out:
 487         condlog(0, "failed to start waiter thread");
 488         return 1;
 489 }
 490
 491 static void
 492 remove_map (struct multipath * mpp, struct paths * allpaths)
 493 {
 494         int i;
 495
 496         /*
 497          * stop the DM event waiter thread
 498          */
 499         if (stop_waiter_thread(mpp, allpaths)) {
 500                 condlog(0, "%s: error canceling waiter thread", mpp->alias);
 501                 /*
 502                  * warrior mode
 503                  */
 504                 free_waiter(mpp->waiter);
 505         }
 506
 507         /*
 508          * clear references to this map
 509          */
 510         unset_paths_owner(allpaths, mpp);
 511
 512         /*
 513          * purge the multipath vector
 514          */
 515         i = find_slot(allpaths->mpvec, (void *)mpp);
 516         vector_del_slot(allpaths->mpvec, i);
 517
 518         /*
 519          * final free
 520          */
 521         free_multipath(mpp, KEEP_PATHS);
 522         mpp = NULL;
 523 }
 524
 525 static void
 526 remove_maps (struct paths * allpaths)
 527 {
 528         int i;
 529         struct multipath * mpp;
 530
 531         vector_foreach_slot (allpaths->mpvec, mpp, i)
 532                 remove_map(mpp, allpaths);
 533
 534         vector_free(allpaths->mpvec);
 535         allpaths->mpvec = NULL;
 536 }
 537
 538 int
 539 uev_add_map (char * devname, struct paths * allpaths)
 540 {
 541         int major, minor, i;
 542         char dev_t[BLK_DEV_SIZE];
 543         char * alias;
 544         struct multipath * mpp;
 545
 546         if (sysfs_get_dev(sysfs_path, devname, dev_t, BLK_DEV_SIZE))
 547                 return 1;
 548
 549         if (sscanf(dev_t, "%d:%d", &major, &minor) != 2)
 550                 return 1;
 551
 552         alias = dm_mapname(major, minor);
 553
 554         if (!alias)
 555                 return 1;
 556
 557         if (!dm_type(alias, DEFAULT_TARGET)) {
 558                 condlog(4, "%s: not a multipath map", alias);
 559                 FREE(alias);
 560                 return 0;
 561         }
 562
 563         mpp = find_mp(allpaths->mpvec, alias);
 564
 565         if (mpp) {
 566                 /*
 567                  * this should not happen,
 568                  * we missed a remove map event (not sent ?)
 569                  */
 570                 condlog(2, "%s: already registered", alias);
 571                 remove_map(mpp, allpaths);
 572         }
 573
 574         /*
 575          * now we can allocate
 576          */
 577         mpp = alloc_multipath();
 578
 579         if (!mpp)
 580                 return 1;
 581
 582         mpp->minor = minor;
 583         mpp->alias = alias;
 584
 585         if (setup_multipath(allpaths, mpp))
 586                 return 1; /* mpp freed in setup_multipath */
 587
 588         if (!vector_alloc_slot(allpaths->mpvec))
 589                 goto out;
 590
 591         vector_set_slot(allpaths->mpvec, mpp);
 592         set_paths_owner(allpaths, mpp);
 593
 594         if (start_waiter_thread(mpp, allpaths))
 595                 goto out;
 596
 597         condlog(2, "add %s devmap", mpp->alias);
 598
 599         return 0;
 600 out:
 601         condlog(2, "add %s devmap failed", mpp->alias);
 602         /*
 603          * purge the multipath vector
 604          */
 605         if ((i = find_slot(allpaths->mpvec, (void *)mpp)) != -1)
 606                 vector_del_slot(allpaths->mpvec, i);
 607
 608         free_multipath(mpp, KEEP_PATHS);
 609         return 1;
 610 }
 611
 612 int
 613 uev_remove_map (char * devname, struct paths * allpaths)
 614 {
 615         int minor;
 616         struct multipath * mpp;
 617
 618         if (sscanf(devname, "dm-%d", &minor) != 1)
 619                 return 1;
 620
 621         mpp = find_mp_by_minor(allpaths->mpvec, minor);
 622
 623         if (!mpp) {
 624                 condlog(3, "%s: devmap not registered, can't remove",
 625                         devname);
 626                 return 1;
 627         }
 628
 629         condlog(2, "remove %s devmap", mpp->alias);
 630         remove_map(mpp, allpaths);
 631
 632         return 0;
 633 }
 634
 635 int
 636 uev_add_path (char * devname, struct paths * allpaths)
 637 {
 638         struct path * pp;
 639
 640         pp = find_path_by_dev(allpaths->pathvec, devname);
 641
 642         if (pp) {
 643                 condlog(3, "%s: already in pathvec");
 644                 return 1;
 645         }
 646         pp = store_pathinfo(allpaths->pathvec, conf->hwtable,
 647                        devname, DI_SYSFS | DI_WWID);
 648
 649         if (!pp) {
 650                 condlog(0, "%s: failed to store path info", devname);
 651                 return 1;
 652         }
 653
 654         condlog(2, "%s: path checker registered", devname);
 655         pp->mpp = find_mp_by_wwid(allpaths->mpvec, pp->wwid);
 656
 657         if (pp->mpp)
 658                 condlog(4, "%s: ownership set to %s",
 659                                 pp->dev_t, pp->mpp->alias);
 660         else
 661                 condlog(4, "%s: orphaned", pp->dev_t);
 662
 663         return 0;
 664 }
 665
 666 int
 667 uev_remove_path (char * devname, struct paths * allpaths)
 668 {
 669         int i;
 670         struct path * pp;
 671
 672         pp = find_path_by_dev(allpaths->pathvec, devname);
 673
 674         if (!pp) {
 675                 condlog(3, "%s: not in pathvec");
 676                 return 1;
 677         }
 678         condlog(2, "remove %s path checker", devname);
 679         i = find_slot(allpaths->pathvec, (void *)pp);
 680         vector_del_slot(allpaths->pathvec, i);
 681         free_path(pp);
 682
 683         return 0;
 684 }
 685
 686 char *
 687 show_paths (struct paths * allpaths)
 688 {
 689         int i, j, k;
 690         struct path * pp;
 691         char * c;
 692         char * reply;
 693
 694         reply = MALLOC(MAX_REPLY_LEN);
 695
 696         if (!reply)
 697                 return NULL;
 698
 699         c = reply;
 700         c += sprintf(c, "\n");
 701
 702         vector_foreach_slot(allpaths->pathvec, pp, i) {
 703                 c += sprintf(c, "%10s: ", pp->dev);
 704
 705                 if (!pp->mpp) {
 706                         c += sprintf(c, "[orphan]\n");
 707                         continue;
 708                 }
 709
 710                 if (MAX_REPLY_LEN - MAX_PSTATE_LEN < 0) {
 711                         FREE(reply);
 712                         return NULL;
 713                 }
 714
 715                 j = pstate_snprintf(c, MAX_PSTATE_LEN, pp->state);
 716                 c += j;
 717                 j = MAX_PSTATE_LEN - j;
 718
 719                 while (j--)
 720                         sprintf(c, " ");
 721
 722                 j = pp->tick;
 723                 k = pp->checkint - pp->tick;
 724                 c += sprintf(c, "%3i/%3i ", j, pp->checkint);
 725
 726                 while (j-- > 0)
 727                         c += sprintf(c, "X");
 728
 729
 730                 while (k-- > 0)
 731                         c += sprintf(c, ".");
 732
 733                 c += sprintf(c, "\n");
 734         }
 735
 736         reply[MAX_REPLY_LEN - 1] = 0;
 737         return reply;
 738 }
 739
 740 char *
 741 show_maps (struct paths * allpaths)
 742 {
 743         int i, j, k;
 744         struct multipath * mpp;
 745         char * c;
 746         char * reply;
 747
 748         reply = MALLOC(MAX_REPLY_LEN);
 749
 750         if (!reply)
 751                 return NULL;
 752
 753         c = reply;
 754         c += sprintf(c, "\n");
 755
 756         vector_foreach_slot(allpaths->mpvec, mpp, i) {
 757                 c += sprintf(c, "%20s: ", mpp->alias);
 758
 759                 if (!mpp->failback_tick) {
 760                         c += sprintf(c, "[no scheduled failback]\n");
 761                         continue;
 762                 }
 763
 764                 j = mpp->failback_tick;
 765                 k = mpp->pgfailback - mpp->failback_tick;
 766                 c += sprintf(c, "%3i/%3i ", j, mpp->pgfailback);
 767
 768                 while (j-- > 0)
 769                         c += sprintf(c, "X");
 770
 771
 772                 while (k-- > 0)
 773                         c += sprintf(c, ".");
 774
 775                 c += sprintf(c, "\n");
 776         }
 777
 778         reply[MAX_REPLY_LEN - 1] = 0;
 779         return reply;
 780 }
 781
 782 char *
 783 uxsock_trigger (char * str, void * trigger_data)
 784 {
 785         struct paths * allpaths;
 786         char * reply = NULL;
 787
 788         allpaths = (struct paths *)trigger_data;
 789
 790         pthread_cleanup_push(cleanup_lock, allpaths->lock);
 791         lock(allpaths->lock);
 792
 793         reply = parse_cmd(str, allpaths);
 794
 795         if (!reply)
 796                 reply = STRDUP("fail\n");
 797
 798         else if (strlen(reply) == 0)
 799                 reply = STRDUP("ok\n");
 800
 801         pthread_cleanup_pop(1);
 802
 803         return reply;
 804 }
 805
 806 int
 807 uev_trigger (struct uevent * uev, void * trigger_data)
 808 {
 809         int r = 0;
 810         char devname[32];
 811         struct paths * allpaths;
 812
 813         allpaths = (struct paths *)trigger_data;
 814         pthread_cleanup_push(cleanup_lock, allpaths->lock);
 815         lock(allpaths->lock);
 816
 817         if (strncmp(uev->devpath, "/block", 6))
 818                 goto out;
 819
 820         basename(uev->devpath, devname);
 821
 822         /*
 823          * device map add/remove event
 824          */
 825         if (!strncmp(devname, "dm-", 3)) {
 826                 if (!strncmp(uev->action, "add", 3)) {
 827                         r = uev_add_map(devname, allpaths);
 828                         goto out;
 829                 }
 830                 if (!strncmp(uev->action, "remove", 6)) {
 831                         r = uev_remove_map(devname, allpaths);
 832                         goto out;
 833                 }
 834                 goto out;
 835         }
 836
 837         /*
 838          * path add/remove event
 839          */
 840         if (blacklist(conf->blist, devname))
 841                 goto out;
 842
 843         if (!strncmp(uev->action, "add", 3)) {
 844                 r = uev_add_path(devname, allpaths);
 845                 goto out;
 846         }
 847         if (!strncmp(uev->action, "remove", 6)) {
 848                 r = uev_remove_path(devname, allpaths);
 849                 goto out;
 850         }
 851
 852 out:
 853         FREE(uev);
 854         pthread_cleanup_pop(1);
 855         return r;
 856 }
 857
 858 static void *
 859 ueventloop (void * ap)
 860 {
 861         uevent_listen(&uev_trigger, ap);
 862
 863         return NULL;
 864 }
 865
 866 static void *
 867 uxlsnrloop (void * ap)
 868 {
 869         if (load_keys())
 870                 return NULL;
 871
 872         if (alloc_handlers())
 873                 return NULL;
 874
 875         add_handler(LIST+PATHS, list_paths);
 876         add_handler(LIST+MAPS, list_maps);
 877         add_handler(ADD+PATH, add_path);
 878         add_handler(DEL+PATH, del_path);
 879         add_handler(ADD+MAP, add_map);
 880         add_handler(DEL+MAP, del_map);
 881         add_handler(SWITCH+MAP+GROUP, switch_group);
 882
 883         uxsock_listen(&uxsock_trigger, ap);
 884
 885         return NULL;
 886 }
 887
 888 static int
 889 exit_daemon (int status)
 890 {
 891         if (status != 0)
 892                 fprintf(stderr, "bad exit status. see daemon.log\n");
 893
 894         condlog(3, "unlink pidfile");
 895         unlink(DEFAULT_PIDFILE);
 896
 897         condlog(2, "--------shut down-------");
 898
 899         lock(&exit_mutex);
 900         pthread_cond_signal(&exit_cond);
 901         unlock(&exit_mutex);
 902
 903         return status;
 904 }
 905
 906 /*
 907  * caller must have locked the path list before calling that function
 908  */
 909 static int
 910 get_dm_mpvec (struct paths * allpaths)
 911 {
 912         int i;
 913         struct multipath * mpp;
 914
 915         if (dm_get_maps(allpaths->mpvec, "multipath"))
 916                 return 1;
 917
 918         vector_foreach_slot (allpaths->mpvec, mpp, i) {
 919                 if (setup_multipath(allpaths, mpp))
 920                         return 1;
 921                 mpp->minor = dm_get_minor(mpp->alias);
 922                 start_waiter_thread(mpp, allpaths);
 923         }
 924
 925         return 0;
 926 }
 927
 928 static void
 929 fail_path (struct path * pp)
 930 {
 931         if (!pp->mpp)
 932                 return;
 933
 934         condlog(2, "checker failed path %s in map %s",
 935                  pp->dev_t, pp->mpp->alias);
 936
 937         dm_fail_path(pp->mpp->alias, pp->dev_t);
 938 }
 939
 940 /*
 941  * caller must have locked the path list before calling that function
 942  */
 943 static void
 944 reinstate_path (struct path * pp)
 945 {
 946         if (pp->mpp) {
 947                 if (dm_reinstate(pp->mpp->alias, pp->dev_t))
 948                         condlog(0, "%s: reinstate failed", pp->dev_t);
 949                 else
 950                         condlog(2, "%s: reinstated", pp->dev_t);
 951         }
 952 }
 953
 954 static void
 955 enable_group(struct path * pp)
 956 {
 957         struct pathgroup * pgp;
 958
 959         pgp = VECTOR_SLOT(pp->mpp->pg, pp->pgindex - 1);
 960
 961         if (pgp->status == PGSTATE_DISABLED) {
 962                 condlog(2, "%s: enable group #%i", pp->mpp->alias, pp->pgindex);
 963                 dm_enablegroup(pp->mpp->alias, pp->pgindex);
 964         }
 965 }
 966
 967 static void
 968 mpvec_garbage_collector (struct paths * allpaths)
 969 {
 970         struct multipath * mpp;
 971         int i;
 972
 973         vector_foreach_slot (allpaths->mpvec, mpp, i) {
 974                 if (!dm_map_present(mpp->alias)) {
 975                         condlog(2, "%s: remove dead map", mpp->alias);
 976                         remove_map(mpp, allpaths);
 977                 }
 978         }
 979 }
 980
 981 static void
 982 defered_failback_tick (vector mpvec)
 983 {
 984         struct multipath * mpp;
 985         int i;
 986
 987         vector_foreach_slot (mpvec, mpp, i) {
 988                 /*
 989                  * defered failback getting sooner
 990                  */
 991                 if (mpp->pgfailback > 0 && mpp->failback_tick > 0) {
 992                         mpp->failback_tick--;
 993
 994                         if (!mpp->failback_tick)
 995                                 switch_pathgroup(mpp);
 996                 }
 997         }
 998 }
 999
1000 static void *
1001 checkerloop (void *ap)
1002 {
1003         struct paths *allpaths;
1004         struct path *pp;
1005         int i, count = 0;
1006         int newstate;
1007         char checker_msg[MAX_CHECKER_MSG_SIZE];
1008
1009         mlockall(MCL_CURRENT | MCL_FUTURE);
1010
1011         memset(checker_msg, 0, MAX_CHECKER_MSG_SIZE);
1012         allpaths = (struct paths *)ap;
1013
1014         condlog(2, "path checkers start up");
1015
1016         while (1) {
1017                 pthread_cleanup_push(cleanup_lock, allpaths->lock);
1018                 lock(allpaths->lock);
1019                 condlog(4, "tick");
1020
1021                 vector_foreach_slot (allpaths->pathvec, pp, i) {
1022                         if (!pp->mpp)
1023                                 continue;
1024
1025                         if (pp->tick) {
1026                                 /*
1027                                  * don't check this path yet
1028                                  */
1029                                 pp->tick--;
1030                                 continue;
1031                         }
1032
1033                         /*
1034                          * provision a next check soonest,
1035                          * in case we exit abnormaly from here
1036                          */
1037                         pp->tick = conf->checkint;
1038
1039                         if (!pp->checkfn) {
1040                                 pathinfo(pp, conf->hwtable, DI_SYSFS);
1041                                 select_checkfn(pp);
1042                         }
1043
1044                         if (!pp->checkfn) {
1045                                 condlog(0, "%s: checkfn is void", pp->dev);
1046                                 continue;
1047                         }
1048                         newstate = pp->checkfn(pp->fd, checker_msg,
1049                                                &pp->checker_context);
1050
1051                         if (newstate != pp->state) {
1052                                 pp->state = newstate;
1053                                 LOG_MSG(1, checker_msg);
1054
1055                                 /*
1056                                  * upon state change, reset the checkint
1057                                  * to the shortest delay
1058                                  */
1059                                 pp->checkint = conf->checkint;
1060
1061                                 if (newstate == PATH_DOWN ||
1062                                     newstate == PATH_SHAKY) {
1063                                         /*
1064                                          * proactively fail path in the DM
1065                                          */
1066                                         fail_path(pp);
1067
1068                                         /*
1069                                          * cancel scheduled failback
1070                                          */
1071                                         pp->mpp->failback_tick = 0;
1072
1073                                         continue;
1074                                 }
1075
1076                                 /*
1077                                  * reinstate this path
1078                                  */
1079                                 reinstate_path(pp);
1080
1081                                 /*
1082                                  * need to switch group ?
1083                                  */
1084                                 update_multipath_strings(pp->mpp,
1085                                                          allpaths->pathvec);
1086
1087                                 /*
1088                                  * schedule defered failback
1089                                  */
1090                                 if (pp->mpp->pgfailback > 0)
1091                                         pp->mpp->failback_tick =
1092                                                 pp->mpp->pgfailback;
1093
1094                                 if (pp->mpp->pgfailback == FAILBACK_IMMEDIATE)
1095                                         switch_pathgroup(pp->mpp);
1096
1097                                 /*
1098                                  * if at least one path is up in a group, and
1099                                  * the group is disabled, re-enable it
1100                                  */
1101                                 if (newstate == PATH_UP)
1102                                         enable_group(pp);
1103                         }
1104                         else if (newstate == PATH_UP || newstate == PATH_GHOST) {
1105                                 LOG_MSG(4, checker_msg);
1106                                 /*
1107                                  * double the next check delay.
1108                                  * max at conf->max_checkint
1109                                  */
1110                                 if (pp->checkint < (conf->max_checkint / 2))
1111                                         pp->checkint = 2 * pp->checkint;
1112                                 else
1113                                         pp->checkint = conf->max_checkint;
1114
1115                                 pp->tick = pp->checkint;
1116                                 condlog(4, "%s: delay next check %is",
1117                                                 pp->dev_t, pp->tick);
1118
1119                         }
1120                         pp->state = newstate;
1121                 }
1122                 defered_failback_tick(allpaths->mpvec);
1123
1124                 if (count)
1125                         count--;
1126                 else {
1127                         condlog(4, "map garbage collection");
1128                         mpvec_garbage_collector(allpaths);
1129                         count = MAPGCINT;
1130                 }
1131
1132                 pthread_cleanup_pop(1);
1133                 sleep(1);
1134         }
1135         return NULL;
1136 }
1137
1138 static struct paths *
1139 init_paths (void)
1140 {
1141         struct paths * allpaths;
1142
1143         allpaths = (struct paths *)MALLOC(sizeof(struct paths));
1144
1145         if (!allpaths)
1146                 return NULL;
1147
1148         allpaths->lock =
1149                 (pthread_mutex_t *)MALLOC(sizeof(pthread_mutex_t));
1150
1151         if (!allpaths->lock)
1152                 goto out;
1153
1154         allpaths->pathvec = vector_alloc();
1155
1156         if (!allpaths->pathvec)
1157                 goto out1;
1158
1159         allpaths->mpvec = vector_alloc();
1160
1161         if (!allpaths->mpvec)
1162                 goto out2;
1163
1164         pthread_mutex_init(allpaths->lock, NULL);
1165
1166         return allpaths;
1167
1168 out2:
1169         vector_free(allpaths->pathvec);
1170 out1:
1171         FREE(allpaths->lock);
1172 out:
1173         FREE(allpaths);
1174         condlog(0, "failed to init paths");
1175         return NULL;
1176 }
1177
1178 static void *
1179 signal_set(int signo, void (*func) (int))
1180 {
1181         int r;
1182         struct sigaction sig;
1183         struct sigaction osig;
1184
1185         sig.sa_handler = func;
1186         sigemptyset(&sig.sa_mask);
1187         sig.sa_flags = 0;
1188
1189         r = sigaction(signo, &sig, &osig);
1190
1191         if (r < 0)
1192                 return (SIG_ERR);
1193         else
1194                 return (osig.sa_handler);
1195 }
1196
1197 static void
1198 sighup (int sig)
1199 {
1200         condlog(2, "SIGHUP received");
1201
1202 #ifdef _DEBUG_
1203         dbg_free_final(NULL);
1204 #endif
1205 }
1206
1207 static void
1208 sigend (int sig)
1209 {
1210         exit_daemon(0);
1211 }
1212
1213 static void
1214 signal_init(void)
1215 {
1216         signal_set(SIGHUP, sighup);
1217         signal_set(SIGINT, sigend);
1218         signal_set(SIGTERM, sigend);
1219         signal_set(SIGKILL, sigend);
1220 }
1221
1222 static void
1223 setscheduler (void)
1224 {
1225         int res;
1226         static struct sched_param sched_param = {
1227                 sched_priority: 99
1228         };
1229
1230         res = sched_setscheduler (0, SCHED_RR, &sched_param);
1231
1232         if (res == -1)
1233                 condlog(LOG_WARNING, "Could not set SCHED_RR at priority 99");
1234         return;
1235 }
1236
1237 static void
1238 set_oom_adj (int val)
1239 {
1240         FILE *fp;
1241
1242         fp = fopen("/proc/self/oom_adj", "w");
1243
1244         if (!fp)
1245                 return;
1246
1247         fprintf(fp, "%i", val);
1248         fclose(fp);
1249 }
1250
1251 static int
1252 child (void * param)
1253 {
1254         pthread_t check_thr, uevent_thr, uxlsnr_thr;
1255         pthread_attr_t attr;
1256         struct paths * allpaths;
1257
1258         mlockall(MCL_CURRENT | MCL_FUTURE);
1259
1260         if (logsink)
1261                 log_thread_start();
1262
1263         condlog(2, "--------start up--------");
1264         condlog(2, "read " DEFAULT_CONFIGFILE);
1265
1266         if (load_config(DEFAULT_CONFIGFILE))
1267                 exit(1);
1268
1269         setlogmask(LOG_UPTO(conf->verbosity + 3));
1270
1271         /*
1272          * fill the voids left in the config file
1273          */
1274         if (!conf->checkint) {
1275                 conf->checkint = CHECKINT;
1276                 conf->max_checkint = MAX_CHECKINT;
1277         }
1278
1279         if (pidfile_create(DEFAULT_PIDFILE, getpid())) {
1280                 if (logsink)
1281                         log_thread_stop();
1282
1283                 exit(1);
1284         }
1285         signal_init();
1286         setscheduler();
1287         set_oom_adj(-17);
1288         allpaths = init_paths();
1289
1290         if (!allpaths)
1291                 exit(1);
1292
1293         if (sysfs_get_mnt_path(sysfs_path, FILE_NAME_SIZE)) {
1294                 condlog(0, "can not find sysfs mount point");
1295                 exit(1);
1296         }
1297
1298         /*
1299          * fetch paths and multipaths lists
1300          * no paths and/or no multipaths are valid scenarii
1301          * vectors maintenance will be driven by events
1302          */
1303         path_discovery(allpaths->pathvec, conf, DI_SYSFS | DI_WWID);
1304         get_dm_mpvec(allpaths);
1305
1306         /*
1307          * start threads
1308          */
1309         pthread_attr_init(&attr);
1310         pthread_attr_setstacksize(&attr, 64 * 1024);
1311         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
1312
1313         pthread_create(&check_thr, &attr, checkerloop, allpaths);
1314         pthread_create(&uevent_thr, &attr, ueventloop, allpaths);
1315         pthread_create(&uxlsnr_thr, &attr, uxlsnrloop, allpaths);
1316
1317         pthread_cond_wait(&exit_cond, &exit_mutex);
1318
1319         /*
1320          * exit path
1321          */
1322         lock(allpaths->lock);
1323         remove_maps(allpaths);
1324         free_pathvec(allpaths->pathvec, FREE_PATHS);
1325
1326         pthread_cancel(check_thr);
1327         pthread_cancel(uevent_thr);
1328         pthread_cancel(uxlsnr_thr);
1329
1330         free_keys(keys);
1331         free_handlers(handlers);
1332         free_polls();
1333
1334         unlock(allpaths->lock);
1335         pthread_mutex_destroy(allpaths->lock);
1336         FREE(allpaths->lock);
1337         FREE(allpaths);
1338         free_config(conf);
1339
1340         if (logsink)
1341                 log_thread_stop();
1342
1343 #ifdef _DEBUG_
1344         dbg_free_final(NULL);
1345 #endif
1346
1347         exit(0);
1348 }
1349
1350 int
1351 main (int argc, char *argv[])
1352 {
1353         extern char *optarg;
1354         extern int optind;
1355         int arg;
1356         int err;
1357
1358         logsink = 1;
1359
1360         if (getuid() != 0) {
1361                 fprintf(stderr, "need to be root\n");
1362                 exit(1);
1363         }
1364
1365         /* make sure we don't lock any path */
1366         chdir("/");
1367         umask(umask(077) | 022);
1368
1369         conf = alloc_config();
1370
1371         if (!conf)
1372                 exit(1);
1373
1374         while ((arg = getopt(argc, argv, ":dv:k::")) != EOF ) {
1375         switch(arg) {
1376                 case 'd':
1377                         logsink = 0;
1378                         //debug=1; /* ### comment me out ### */
1379                         break;
1380                 case 'v':
1381                         if (sizeof(optarg) > sizeof(char *) ||
1382                             !isdigit(optarg[0]))
1383                                 exit(1);
1384
1385                         conf->verbosity = atoi(optarg);
1386                         break;
1387                 case 'k':
1388                         uxclnt(optarg);
1389                         exit(0);
1390                 default:
1391                         ;
1392                 }
1393         }
1394
1395         err = fork();
1396
1397         if (err < 0)
1398                 /* error */
1399                 exit(1);
1400         else if (err > 0)
1401                 /* parent dies */
1402                 exit(0);
1403         else
1404                 /* child lives */
1405                 return (child(NULL));
1406 }