multipathd/main.c

   1 /*
   2  * Copyright (c) 2004, 2005 Christophe Varoqui
   3  * Copyright (c) 2005 Kiyoshi Ueda, NEC
   4  * Copyright (c) 2005 Benjamin Marzinski, Redhat
   5  * Copyright (c) 2005 Edward Goggin, EMC
   6  */
   7 #include <unistd.h>
   8 #include <sys/stat.h>
   9 #include <libdevmapper.h>
  10 #include <wait.h>
  11 #include <sys/mman.h>
  12 #include <sys/types.h>
  13 #include <fcntl.h>
  14 #include <errno.h>
  15 #include <sys/time.h>
  16 #include <sys/resource.h>
  17
  18 /*
  19  * libcheckers
  20  */
  21 #include <checkers.h>
  22
  23 /*
  24  * libmultipath
  25  */
  26 #include <parser.h>
  27 #include <vector.h>
  28 #include <memory.h>
  29 #include <config.h>
  30 #include <util.h>
  31 #include <hwtable.h>
  32 #include <defaults.h>
  33 #include <structs.h>
  34 #include <callout.h>
  35 #include <blacklist.h>
  36 #include <structs_vec.h>
  37 #include <dmparser.h>
  38 #include <devmapper.h>
  39 #include <sysfs.h>
  40 #include <dict.h>
  41 #include <discovery.h>
  42 #include <debug.h>
  43 #include <propsel.h>
  44 #include <uevent.h>
  45 #include <switchgroup.h>
  46 #include <print.h>
  47 #include <configure.h>
  48 #include <prio.h>
  49
  50 #include "main.h"
  51 #include "pidfile.h"
  52 #include "uxlsnr.h"
  53 #include "uxclnt.h"
  54 #include "cli.h"
  55 #include "cli_handlers.h"
  56 #include "lock.h"
  57 #include "waiter.h"
  58
  59 #define FILE_NAME_SIZE 256
  60 #define CMDSIZE 160
  61
  62 #define LOG_MSG(a,b) \
  63         if (strlen(b)) condlog(a, "%s: %s", pp->dev, b);
  64
  65 pthread_cond_t exit_cond = PTHREAD_COND_INITIALIZER;
  66 pthread_mutex_t exit_mutex = PTHREAD_MUTEX_INITIALIZER;
  67
  68 int logsink;
  69
  70 /*
  71  * global copy of vecs for use in sig handlers
  72  */
  73 struct vectors * gvecs;
  74
  75 static int
  76 need_switch_pathgroup (struct multipath * mpp, int refresh)
  77 {
  78         struct pathgroup * pgp;
  79         struct path * pp;
  80         unsigned int i, j;
  81
  82         if (!mpp || mpp->pgfailback == -FAILBACK_MANUAL)
  83                 return 0;
  84
  85         /*
  86          * Refresh path priority values
  87          */
  88         if (refresh)
  89                 vector_foreach_slot (mpp->pg, pgp, i)
  90                         vector_foreach_slot (pgp->paths, pp, j)
  91                                 pathinfo(pp, conf->hwtable, DI_PRIO);
  92
  93         mpp->bestpg = select_path_group(mpp);
  94
  95         if (mpp->bestpg != mpp->nextpg)
  96                 return 1;
  97
  98         return 0;
  99 }
 100
 101 static void
 102 switch_pathgroup (struct multipath * mpp)
 103 {
 104         mpp->stat_switchgroup++;
 105         dm_switchgroup(mpp->alias, mpp->bestpg);
 106         condlog(2, "%s: switch to path group #%i",
 107                  mpp->alias, mpp->bestpg);
 108 }
 109
 110 static int
 111 coalesce_maps(struct vectors *vecs, vector nmpv)
 112 {
 113         struct multipath * ompp;
 114         vector ompv = vecs->mpvec;
 115         unsigned int i;
 116         int j;
 117
 118         vector_foreach_slot (ompv, ompp, i) {
 119                 if (!find_mp_by_wwid(nmpv, ompp->wwid)) {
 120                         /*
 121                          * remove all current maps not allowed by the
 122                          * current configuration
 123                          */
 124                         if (dm_flush_map(ompp->alias)) {
 125                                 condlog(0, "%s: unable to flush devmap",
 126                                         ompp->alias);
 127                                 /*
 128                                  * may be just because the device is open
 129                                  */
 130                                 if (!vector_alloc_slot(nmpv))
 131                                         return 1;
 132
 133                                 vector_set_slot(nmpv, ompp);
 134                                 setup_multipath(vecs, ompp);
 135
 136                                 if ((j = find_slot(ompv, (void *)ompp)) != -1)
 137                                         vector_del_slot(ompv, j);
 138
 139                                 continue;
 140                         }
 141                         else {
 142                                 dm_lib_release();
 143                                 condlog(2, "%s devmap removed", ompp->alias);
 144                         }
 145                 }
 146         }
 147         return 0;
 148 }
 149
 150 static void
 151 sync_map_state(struct multipath *mpp)
 152 {
 153         struct pathgroup *pgp;
 154         struct path *pp;
 155         unsigned int i, j;
 156
 157         if (!mpp->pg)
 158                 return;
 159
 160         vector_foreach_slot (mpp->pg, pgp, i){
 161                 vector_foreach_slot (pgp->paths, pp, j){
 162                         if (pp->state == PATH_UNCHECKED ||
 163                             pp->state == PATH_WILD)
 164                                 continue;
 165                         if ((pp->dmstate == PSTATE_FAILED ||
 166                              pp->dmstate == PSTATE_UNDEF) &&
 167                             (pp->state == PATH_UP || pp->state == PATH_GHOST))
 168                                 dm_reinstate_path(mpp->alias, pp->dev_t);
 169                         else if ((pp->dmstate == PSTATE_ACTIVE ||
 170                                   pp->dmstate == PSTATE_UNDEF) &&
 171                                  (pp->state == PATH_DOWN ||
 172                                   pp->state == PATH_SHAKY))
 173                                 dm_fail_path(mpp->alias, pp->dev_t);
 174                 }
 175         }
 176 }
 177
 178 static void
 179 sync_maps_state(vector mpvec)
 180 {
 181         unsigned int i;
 182         struct multipath *mpp;
 183
 184         vector_foreach_slot (mpvec, mpp, i)
 185                 sync_map_state(mpp);
 186 }
 187
 188 static int
 189 flush_map(struct multipath * mpp, struct vectors * vecs)
 190 {
 191         /*
 192          * clear references to this map before flushing so we can ignore
 193          * the spurious uevent we may generate with the dm_flush_map call below
 194          */
 195         if (dm_flush_map(mpp->alias)) {
 196                 /*
 197                  * May not really be an error -- if the map was already flushed
 198                  * from the device mapper by dmsetup(8) for instance.
 199                  */
 200                 condlog(0, "%s: can't flush", mpp->alias);
 201                 return 1;
 202         }
 203         else {
 204                 dm_lib_release();
 205                 condlog(2, "%s: devmap removed", mpp->alias);
 206         }
 207
 208         orphan_paths(vecs->pathvec, mpp);
 209         remove_map_and_stop_waiter(mpp, vecs, 1);
 210
 211         return 0;
 212 }
 213
 214 static int
 215 uev_add_map (struct sysfs_device * dev, struct vectors * vecs)
 216 {
 217         condlog(2, "%s: add map (uevent)", dev->kernel);
 218         return ev_add_map(dev, vecs);
 219 }
 220
 221 int
 222 ev_add_map (struct sysfs_device * dev, struct vectors * vecs)
 223 {
 224         char * alias;
 225         char *dev_t;
 226         int major, minor;
 227         char * refwwid;
 228         struct multipath * mpp;
 229         int map_present;
 230         int r = 1;
 231
 232         dev_t = sysfs_attr_get_value(dev->devpath, "dev");
 233
 234         if (!dev_t || sscanf(dev_t, "%d:%d", &major, &minor) != 2)
 235                 return 1;
 236
 237         alias = dm_mapname(major, minor);
 238
 239         if (!alias)
 240                 return 1;
 241
 242         map_present = dm_map_present(alias);
 243
 244         if (map_present && dm_type(alias, TGT_MPATH) <= 0) {
 245                 condlog(4, "%s: not a multipath map", alias);
 246                 return 0;
 247         }
 248
 249         mpp = find_mp_by_alias(vecs->mpvec, alias);
 250
 251         if (mpp) {
 252                 /*
 253                  * Not really an error -- we generate our own uevent
 254                  * if we create a multipath mapped device as a result
 255                  * of uev_add_path
 256                  */
 257                 condlog(0, "%s: devmap already registered",
 258                         dev->kernel);
 259                 return 0;
 260         }
 261
 262         /*
 263          * now we can register the map
 264          */
 265         if (map_present && (mpp = add_map_without_path(vecs, minor, alias))) {
 266                 sync_map_state(mpp);
 267                 condlog(2, "%s: devmap %s added", alias, dev->kernel);
 268                 return 0;
 269         }
 270         refwwid = get_refwwid(dev->kernel, DEV_DEVMAP, vecs->pathvec);
 271
 272         if (refwwid) {
 273                 r = coalesce_paths(vecs, NULL, refwwid, 0);
 274                 dm_lib_release();
 275         }
 276
 277         if (!r)
 278                 condlog(2, "%s: devmap %s added", alias, dev->kernel);
 279         else
 280                 condlog(0, "%s: uev_add_map %s failed", alias, dev->kernel);
 281
 282         FREE(refwwid);
 283         return r;
 284 }
 285
 286 static int
 287 uev_remove_map (struct sysfs_device * dev, struct vectors * vecs)
 288 {
 289         condlog(2, "%s: remove map (uevent)", dev->kernel);
 290         return ev_remove_map(dev->kernel, vecs);
 291 }
 292
 293 int
 294 ev_remove_map (char * devname, struct vectors * vecs)
 295 {
 296         struct multipath * mpp;
 297
 298         mpp = find_mp_by_str(vecs->mpvec, devname);
 299
 300         if (!mpp) {
 301                 condlog(2, "%s: devmap not registered, can't remove",
 302                         devname);
 303                 return 0;
 304         }
 305         flush_map(mpp, vecs);
 306
 307         return 0;
 308 }
 309
 310 static int
 311 uev_umount_map (struct sysfs_device * dev, struct vectors * vecs)
 312 {
 313         struct multipath * mpp;
 314
 315         condlog(2, "%s: umount map (uevent)", dev->kernel);
 316
 317         mpp = find_mp_by_str(vecs->mpvec, dev->kernel);
 318
 319         if (!mpp)
 320                 return 0;
 321
 322         update_mpp_paths(mpp, vecs->pathvec);
 323         verify_paths(mpp, vecs, NULL);
 324
 325         if (!VECTOR_SIZE(mpp->paths))
 326                 flush_map(mpp, vecs);
 327
 328         return 0;
 329 }
 330
 331 static int
 332 uev_add_path (struct sysfs_device * dev, struct vectors * vecs)
 333 {
 334         condlog(2, "%s: add path (uevent)", dev->kernel);
 335         return (ev_add_path(dev->kernel, vecs) != 1)? 0 : 1;
 336 }
 337
 338
 339 /*
 340  * returns:
 341  * 0: added
 342  * 1: error
 343  * 2: blacklisted
 344  */
 345 int
 346 ev_add_path (char * devname, struct vectors * vecs)
 347 {
 348         struct multipath * mpp;
 349         struct path * pp;
 350         char empty_buff[WWID_SIZE] = {0};
 351
 352         pp = find_path_by_dev(vecs->pathvec, devname);
 353
 354         if (pp) {
 355                 condlog(0, "%s: spurious uevent, path already in pathvec",
 356                         devname);
 357                 if (pp->mpp)
 358                         return 0;
 359         }
 360         else {
 361                 /*
 362                  * get path vital state
 363                  */
 364                 if (!(pp = store_pathinfo(vecs->pathvec, conf->hwtable,
 365                       devname, DI_ALL))) {
 366                         condlog(0, "%s: failed to store path info", devname);
 367                         return 1;
 368                 }
 369                 pp->checkint = conf->checkint;
 370         }
 371
 372         /*
 373          * need path UID to go any further
 374          */
 375         if (memcmp(empty_buff, pp->wwid, WWID_SIZE) == 0) {
 376                 condlog(0, "%s: failed to get path uid", devname);
 377                 return 1; /* leave path added to pathvec */
 378         }
 379         if (filter_path(conf, pp) > 0){
 380                 int i = find_slot(vecs->pathvec, (void *)pp);
 381                 if (i != -1)
 382                         vector_del_slot(vecs->pathvec, i);
 383                 free_path(pp);
 384                 return 2;
 385         }
 386         mpp = pp->mpp = find_mp_by_wwid(vecs->mpvec, pp->wwid);
 387 rescan:
 388         if (mpp) {
 389                 if (adopt_paths(vecs->pathvec, mpp))
 390                         return 1; /* leave path added to pathvec */
 391
 392                 verify_paths(mpp, vecs, NULL);
 393                 mpp->action = ACT_RELOAD;
 394         }
 395         else {
 396                 if ((mpp = add_map_with_path(vecs, pp, 1)))
 397                         mpp->action = ACT_CREATE;
 398                 else
 399                         return 1; /* leave path added to pathvec */
 400         }
 401
 402         /*
 403          * push the map to the device-mapper
 404          */
 405         if (setup_map(mpp)) {
 406                 condlog(0, "%s: failed to setup map for addition of new "
 407                         "path %s", mpp->alias, devname);
 408                 goto out;
 409         }
 410         /*
 411          * reload the map for the multipath mapped device
 412          */
 413         if (domap(mpp) <= 0) {
 414                 condlog(0, "%s: failed in domap for addition of new "
 415                         "path %s", mpp->alias, devname);
 416                 /*
 417                  * deal with asynchronous uevents :((
 418                  */
 419                 if (mpp->action == ACT_RELOAD) {
 420                         condlog(0, "%s: uev_add_path sleep", mpp->alias);
 421                         sleep(1);
 422                         update_mpp_paths(mpp, vecs->pathvec);
 423                         goto rescan;
 424                 }
 425                 else
 426                         goto out;
 427         }
 428         dm_lib_release();
 429
 430         /*
 431          * update our state from kernel regardless of create or reload
 432          */
 433         if (setup_multipath(vecs, mpp))
 434                 goto out;
 435
 436         sync_map_state(mpp);
 437
 438         if (mpp->action == ACT_CREATE &&
 439             start_waiter_thread(mpp, vecs))
 440                         goto out;
 441
 442         condlog(2, "%s path added to devmap %s", devname, mpp->alias);
 443         return 0;
 444
 445 out:
 446         remove_map(mpp, vecs, 1);
 447         return 1;
 448 }
 449
 450 static int
 451 uev_remove_path (struct sysfs_device * dev, struct vectors * vecs)
 452 {
 453         int retval;
 454
 455         condlog(2, "%s: remove path (uevent)", dev->kernel);
 456         retval = ev_remove_path(dev->kernel, vecs);
 457         if (!retval)
 458                 sysfs_device_put(dev);
 459
 460         return retval;
 461 }
 462
 463 int
 464 ev_remove_path (char * devname, struct vectors * vecs)
 465 {
 466         struct multipath * mpp;
 467         struct path * pp;
 468         int i, retval = 0;
 469
 470         pp = find_path_by_dev(vecs->pathvec, devname);
 471
 472         if (!pp) {
 473                 condlog(0, "%s: spurious uevent, path not in pathvec", devname);
 474                 return 1;
 475         }
 476
 477         /*
 478          * avoid referring to the map of an orphaned path
 479          */
 480         if ((mpp = pp->mpp)) {
 481                 /*
 482                  * transform the mp->pg vector of vectors of paths
 483                  * into a mp->params string to feed the device-mapper
 484                  */
 485                 if (update_mpp_paths(mpp, vecs->pathvec)) {
 486                         condlog(0, "%s: failed to update paths",
 487                                 mpp->alias);
 488                         goto out;
 489                 }
 490                 if ((i = find_slot(mpp->paths, (void *)pp)) != -1)
 491                         vector_del_slot(mpp->paths, i);
 492
 493                 /*
 494                  * remove the map IFF removing the last path
 495                  */
 496                 if (VECTOR_SIZE(mpp->paths) == 0) {
 497                         char alias[WWID_SIZE];
 498
 499                         /*
 500                          * flush_map will fail if the device is open
 501                          */
 502                         strncpy(alias, mpp->alias, WWID_SIZE);
 503                         if (!flush_map(mpp, vecs)) {
 504                                 condlog(2, "%s: removed map after"
 505                                         " removing all paths",
 506                                         alias);
 507                                 free_path(pp);
 508                                 return 0;
 509                         }
 510                         /*
 511                          * Not an error, continue
 512                          */
 513                 }
 514
 515                 if (setup_map(mpp)) {
 516                         condlog(0, "%s: failed to setup map for"
 517                                 " removal of path %s", mpp->alias,
 518                                 devname);
 519                         goto out;
 520                 }
 521                 /*
 522                  * reload the map
 523                  */
 524                 mpp->action = ACT_RELOAD;
 525                 if (domap(mpp) <= 0) {
 526                         condlog(0, "%s: failed in domap for "
 527                                 "removal of path %s",
 528                                 mpp->alias, devname);
 529                         retval = 1;
 530                 } else {
 531                         /*
 532                          * update our state from kernel
 533                          */
 534                         if (setup_multipath(vecs, mpp)) {
 535                                 goto out;
 536                         }
 537                         sync_map_state(mpp);
 538
 539                         condlog(2, "%s: path removed from map %s",
 540                                 devname, mpp->alias);
 541                 }
 542         }
 543
 544         if ((i = find_slot(vecs->pathvec, (void *)pp)) != -1)
 545                 vector_del_slot(vecs->pathvec, i);
 546
 547         free_path(pp);
 548
 549         return retval;
 550
 551 out:
 552         remove_map_and_stop_waiter(mpp, vecs, 1);
 553         return 1;
 554 }
 555
 556 static int
 557 map_discovery (struct vectors * vecs)
 558 {
 559         struct multipath * mpp;
 560         unsigned int i;
 561
 562         if (dm_get_maps(vecs->mpvec))
 563                 return 1;
 564
 565         vector_foreach_slot (vecs->mpvec, mpp, i)
 566                 if (setup_multipath(vecs, mpp))
 567                         return 1;
 568
 569         return 0;
 570 }
 571
 572 int
 573 uxsock_trigger (char * str, char ** reply, int * len, void * trigger_data)
 574 {
 575         struct vectors * vecs;
 576         int r;
 577
 578         *reply = NULL;
 579         *len = 0;
 580         vecs = (struct vectors *)trigger_data;
 581
 582         pthread_cleanup_push(cleanup_lock, vecs->lock);
 583         lock(vecs->lock);
 584
 585         r = parse_cmd(str, reply, len, vecs);
 586
 587         if (r > 0) {
 588                 *reply = STRDUP("fail\n");
 589                 *len = strlen(*reply) + 1;
 590                 r = 1;
 591         }
 592         else if (!r && *len == 0) {
 593                 *reply = STRDUP("ok\n");
 594                 *len = strlen(*reply) + 1;
 595                 r = 0;
 596         }
 597         /* else if (r < 0) leave *reply alone */
 598
 599         lock_cleanup_pop(vecs->lock);
 600         return r;
 601 }
 602
 603 static int
 604 uev_discard(char * devpath)
 605 {
 606         char *tmp;
 607         char a[10], b[10];
 608
 609         /*
 610          * keep only block devices, discard partitions
 611          */
 612         tmp = strstr(devpath, "/block/");
 613         if (tmp == NULL){
 614                 condlog(0, "no /block/ in '%s'", devpath);
 615                 return 1;
 616         }
 617         if (sscanf(tmp, "/block/%10s", a) != 1 ||
 618             sscanf(tmp, "/block/%10[^/]/%10s", a, b) == 2) {
 619                 condlog(0, "discard event on %s", devpath);
 620                 return 1;
 621         }
 622         return 0;
 623 }
 624
 625 int
 626 uev_trigger (struct uevent * uev, void * trigger_data)
 627 {
 628         int r = 0;
 629         struct sysfs_device *sysdev;
 630         struct vectors * vecs;
 631
 632         vecs = (struct vectors *)trigger_data;
 633
 634         if (uev_discard(uev->devpath))
 635                 return 0;
 636
 637         sysdev = sysfs_device_get(uev->devpath);
 638         if(!sysdev)
 639                 return 0;
 640
 641         lock(vecs->lock);
 642
 643         /*
 644          * device map event
 645          * Add events are ignored here as the tables
 646          * are not fully initialised then.
 647          */
 648         if (!strncmp(sysdev->kernel, "dm-", 3)) {
 649                 if (!strncmp(uev->action, "change", 6)) {
 650                         r = uev_add_map(sysdev, vecs);
 651                         goto out;
 652                 }
 653                 if (!strncmp(uev->action, "remove", 6)) {
 654                         r = uev_remove_map(sysdev, vecs);
 655                         goto out;
 656                 }
 657                 if (!strncmp(uev->action, "umount", 6)) {
 658                         r = uev_umount_map(sysdev, vecs);
 659                         goto out;
 660                 }
 661                 goto out;
 662         }
 663
 664         /*
 665          * path add/remove event
 666          */
 667         if (filter_devnode(conf->blist_devnode, conf->elist_devnode,
 668                            sysdev->kernel) > 0)
 669                 goto out;
 670
 671         if (!strncmp(uev->action, "add", 3)) {
 672                 r = uev_add_path(sysdev, vecs);
 673                 goto out;
 674         }
 675         if (!strncmp(uev->action, "remove", 6)) {
 676                 r = uev_remove_path(sysdev, vecs);
 677                 goto out;
 678         }
 679
 680 out:
 681         unlock(vecs->lock);
 682         return r;
 683 }
 684
 685 static void *
 686 ueventloop (void * ap)
 687 {
 688         if (uevent_listen(&uev_trigger, ap))
 689                 fprintf(stderr, "error starting uevent listener");
 690
 691         return NULL;
 692 }
 693
 694 static void *
 695 uxlsnrloop (void * ap)
 696 {
 697         if (cli_init())
 698                 return NULL;
 699
 700         set_handler_callback(LIST+PATHS, cli_list_paths);
 701         set_handler_callback(LIST+PATHS+FMT, cli_list_paths_fmt);
 702         set_handler_callback(LIST+MAPS, cli_list_maps);
 703         set_handler_callback(LIST+STATUS, cli_list_status);
 704         set_handler_callback(LIST+MAPS+STATUS, cli_list_maps_status);
 705         set_handler_callback(LIST+MAPS+STATS, cli_list_maps_stats);
 706         set_handler_callback(LIST+MAPS+FMT, cli_list_maps_fmt);
 707         set_handler_callback(LIST+MAPS+TOPOLOGY, cli_list_maps_topology);
 708         set_handler_callback(LIST+TOPOLOGY, cli_list_maps_topology);
 709         set_handler_callback(LIST+MAP+TOPOLOGY, cli_list_map_topology);
 710         set_handler_callback(LIST+CONFIG, cli_list_config);
 711         set_handler_callback(LIST+BLACKLIST, cli_list_blacklist);
 712         set_handler_callback(LIST+DEVICES, cli_list_devices);
 713         set_handler_callback(LIST+WILDCARDS, cli_list_wildcards);
 714         set_handler_callback(ADD+PATH, cli_add_path);
 715         set_handler_callback(DEL+PATH, cli_del_path);
 716         set_handler_callback(ADD+MAP, cli_add_map);
 717         set_handler_callback(DEL+MAP, cli_del_map);
 718         set_handler_callback(SWITCH+MAP+GROUP, cli_switch_group);
 719         set_handler_callback(RECONFIGURE, cli_reconfigure);
 720         set_handler_callback(SUSPEND+MAP, cli_suspend);
 721         set_handler_callback(RESUME+MAP, cli_resume);
 722         set_handler_callback(REINSTATE+PATH, cli_reinstate);
 723         set_handler_callback(FAIL+PATH, cli_fail);
 724         set_handler_callback(QUIT, cli_quit);
 725
 726         uxsock_listen(&uxsock_trigger, ap);
 727
 728         return NULL;
 729 }
 730
 731 static int
 732 exit_daemon (int status)
 733 {
 734         if (status != 0)
 735                 fprintf(stderr, "bad exit status. see daemon.log\n");
 736
 737         condlog(3, "unlink pidfile");
 738         unlink(DEFAULT_PIDFILE);
 739
 740         lock(&exit_mutex);
 741         pthread_cond_signal(&exit_cond);
 742         unlock(&exit_mutex);
 743
 744         return status;
 745 }
 746
 747 static void
 748 fail_path (struct path * pp, int del_active)
 749 {
 750         if (!pp->mpp)
 751                 return;
 752
 753         condlog(2, "checker failed path %s in map %s",
 754                  pp->dev_t, pp->mpp->alias);
 755
 756         dm_fail_path(pp->mpp->alias, pp->dev_t);
 757         if (del_active)
 758                 update_queue_mode_del_path(pp->mpp);
 759 }
 760
 761 /*
 762  * caller must have locked the path list before calling that function
 763  */
 764 static void
 765 reinstate_path (struct path * pp, int add_active)
 766 {
 767         if (!pp->mpp)
 768                 return;
 769
 770         if (dm_reinstate_path(pp->mpp->alias, pp->dev_t))
 771                 condlog(0, "%s: reinstate failed", pp->dev_t);
 772         else {
 773                 condlog(2, "%s: reinstated", pp->dev_t);
 774                 if (add_active)
 775                         update_queue_mode_add_path(pp->mpp);
 776         }
 777 }
 778
 779 static void
 780 enable_group(struct path * pp)
 781 {
 782         struct pathgroup * pgp;
 783
 784         /*
 785          * if path is added through uev_add_path, pgindex can be unset.
 786          * next update_strings() will set it, upon map reload event.
 787          *
 788          * we can safely return here, because upon map reload, all
 789          * PG will be enabled.
 790          */
 791         if (!pp->mpp->pg || !pp->pgindex)
 792                 return;
 793
 794         pgp = VECTOR_SLOT(pp->mpp->pg, pp->pgindex - 1);
 795
 796         if (pgp->status == PGSTATE_DISABLED) {
 797                 condlog(2, "%s: enable group #%i", pp->mpp->alias, pp->pgindex);
 798                 dm_enablegroup(pp->mpp->alias, pp->pgindex);
 799         }
 800 }
 801
 802 static void
 803 mpvec_garbage_collector (struct vectors * vecs)
 804 {
 805         struct multipath * mpp;
 806         unsigned int i;
 807
 808         vector_foreach_slot (vecs->mpvec, mpp, i) {
 809                 if (mpp && mpp->alias && !dm_map_present(mpp->alias)) {
 810                         condlog(2, "%s: remove dead map", mpp->alias);
 811                         remove_map_and_stop_waiter(mpp, vecs, 1);
 812                         i--;
 813                 }
 814         }
 815 }
 816
 817 static void
 818 defered_failback_tick (vector mpvec)
 819 {
 820         struct multipath * mpp;
 821         unsigned int i;
 822
 823         vector_foreach_slot (mpvec, mpp, i) {
 824                 /*
 825                  * defered failback getting sooner
 826                  */
 827                 if (mpp->pgfailback > 0 && mpp->failback_tick > 0) {
 828                         mpp->failback_tick--;
 829
 830                         if (!mpp->failback_tick && need_switch_pathgroup(mpp, 1))
 831                                 switch_pathgroup(mpp);
 832                 }
 833         }
 834 }
 835
 836 static void
 837 retry_count_tick(vector mpvec)
 838 {
 839         struct multipath *mpp;
 840         unsigned int i;
 841
 842         vector_foreach_slot (mpvec, mpp, i) {
 843                 if (mpp->retry_tick) {
 844                         mpp->stat_total_queueing_time++;
 845                         condlog(4, "%s: Retrying.. No active path", mpp->alias);
 846                         if(--mpp->retry_tick == 0) {
 847                                 dm_queue_if_no_path(mpp->alias, 0);
 848                                 condlog(2, "%s: Disable queueing", mpp->alias);
 849                         }
 850                 }
 851         }
 852 }
 853
 854 void
 855 check_path (struct vectors * vecs, struct path * pp)
 856 {
 857         int newstate;
 858
 859         if (!pp->mpp)
 860                 return;
 861
 862         if (pp->tick && --pp->tick)
 863                 return; /* don't check this path yet */
 864
 865         /*
 866          * provision a next check soonest,
 867          * in case we exit abnormaly from here
 868          */
 869         pp->tick = conf->checkint;
 870
 871         if (!checker_selected(&pp->checker)) {
 872                 pathinfo(pp, conf->hwtable, DI_SYSFS);
 873                 select_checker(pp);
 874         }
 875         if (!checker_selected(&pp->checker)) {
 876                 condlog(0, "%s: checker is not set", pp->dev);
 877                 return;
 878         }
 879         /*
 880          * Set checker in async mode.
 881          * Honored only by checker implementing the said mode.
 882          */
 883         checker_set_async(&pp->checker);
 884
 885         if (path_offline(pp))
 886                 newstate = PATH_DOWN;
 887         else
 888                 newstate = checker_check(&pp->checker);
 889
 890         if (newstate < 0) {
 891                 condlog(2, "%s: unusable path", pp->dev);
 892                 pathinfo(pp, conf->hwtable, 0);
 893                 return;
 894         }
 895         /*
 896          * Async IO in flight. Keep the previous path state
 897          * and reschedule as soon as possible
 898          */
 899         if (newstate == PATH_PENDING) {
 900                 pp->tick = 1;
 901                 return;
 902         }
 903         if (newstate != pp->state) {
 904                 int oldstate = pp->state;
 905                 pp->state = newstate;
 906                 LOG_MSG(1, checker_message(&pp->checker));
 907
 908                 /*
 909                  * upon state change, reset the checkint
 910                  * to the shortest delay
 911                  */
 912                 pp->checkint = conf->checkint;
 913
 914                 if (newstate == PATH_DOWN || newstate == PATH_SHAKY ||
 915                     update_multipath_strings(pp->mpp, vecs->pathvec)) {
 916                         /*
 917                          * proactively fail path in the DM
 918                          */
 919                         if (oldstate == PATH_UP ||
 920                             oldstate == PATH_GHOST)
 921                                 fail_path(pp, 1);
 922                         else
 923                                 fail_path(pp, 0);
 924
 925                         /*
 926                          * cancel scheduled failback
 927                          */
 928                         pp->mpp->failback_tick = 0;
 929
 930                         pp->mpp->stat_path_failures++;
 931                         return;
 932                 }
 933
 934                 /*
 935                  * reinstate this path
 936                  */
 937                 if (oldstate != PATH_UP &&
 938                     oldstate != PATH_GHOST)
 939                         reinstate_path(pp, 1);
 940                 else
 941                         reinstate_path(pp, 0);
 942
 943                 /*
 944                  * schedule [defered] failback
 945                  */
 946                 if (pp->mpp->pgfailback > 0)
 947                         pp->mpp->failback_tick =
 948                                 pp->mpp->pgfailback + 1;
 949                 else if (pp->mpp->pgfailback == -FAILBACK_IMMEDIATE &&
 950                     need_switch_pathgroup(pp->mpp, 1))
 951                         switch_pathgroup(pp->mpp);
 952
 953                 /*
 954                  * if at least one path is up in a group, and
 955                  * the group is disabled, re-enable it
 956                  */
 957                 if (newstate == PATH_UP)
 958                         enable_group(pp);
 959         }
 960         else if (newstate == PATH_UP || newstate == PATH_GHOST) {
 961                 LOG_MSG(4, checker_message(&pp->checker));
 962                 /*
 963                  * double the next check delay.
 964                  * max at conf->max_checkint
 965                  */
 966                 if (pp->checkint < (conf->max_checkint / 2))
 967                         pp->checkint = 2 * pp->checkint;
 968                 else
 969                         pp->checkint = conf->max_checkint;
 970
 971                 pp->tick = pp->checkint;
 972                 condlog(4, "%s: delay next check %is",
 973                                 pp->dev_t, pp->tick);
 974         }
 975         else if (newstate == PATH_DOWN)
 976                 LOG_MSG(2, checker_message(&pp->checker));
 977
 978         pp->state = newstate;
 979
 980         /*
 981          * path prio refreshing
 982          */
 983         condlog(4, "path prio refresh");
 984         pathinfo(pp, conf->hwtable, DI_PRIO);
 985
 986         /*
 987          * pathgroup failback policy
 988          */
 989         if (need_switch_pathgroup(pp->mpp, 0)) {
 990                 if (pp->mpp->pgfailback > 0 &&
 991                     pp->mpp->failback_tick <= 0)
 992                         pp->mpp->failback_tick =
 993                                 pp->mpp->pgfailback + 1;
 994                 else if (pp->mpp->pgfailback ==
 995                                 -FAILBACK_IMMEDIATE)
 996                         switch_pathgroup(pp->mpp);
 997         }
 998 }
 999
1000 static void *
1001 checkerloop (void *ap)
1002 {
1003         struct vectors *vecs;
1004         struct path *pp;
1005         int count = 0;
1006         unsigned int i;
1007
1008         mlockall(MCL_CURRENT | MCL_FUTURE);
1009         vecs = (struct vectors *)ap;
1010         condlog(2, "path checkers start up");
1011
1012         /*
1013          * init the path check interval
1014          */
1015         vector_foreach_slot (vecs->pathvec, pp, i) {
1016                 pp->checkint = conf->checkint;
1017         }
1018
1019         while (1) {
1020                 pthread_cleanup_push(cleanup_lock, vecs->lock);
1021                 lock(vecs->lock);
1022                 condlog(4, "tick");
1023
1024                 if (vecs->pathvec) {
1025                         vector_foreach_slot (vecs->pathvec, pp, i) {
1026                                 check_path(vecs, pp);
1027                         }
1028                 }
1029                 if (vecs->mpvec) {
1030                         defered_failback_tick(vecs->mpvec);
1031                         retry_count_tick(vecs->mpvec);
1032                 }
1033                 if (count)
1034                         count--;
1035                 else {
1036                         condlog(4, "map garbage collection");
1037                         mpvec_garbage_collector(vecs);
1038                         count = MAPGCINT;
1039                 }
1040
1041                 lock_cleanup_pop(vecs->lock);
1042                 sleep(1);
1043         }
1044         return NULL;
1045 }
1046
1047 int
1048 configure (struct vectors * vecs, int start_waiters)
1049 {
1050         struct multipath * mpp;
1051         struct path * pp;
1052         vector mpvec;
1053         int i;
1054
1055         if (!vecs->pathvec && !(vecs->pathvec = vector_alloc()))
1056                 return 1;
1057
1058         if (!vecs->mpvec && !(vecs->mpvec = vector_alloc()))
1059                 return 1;
1060
1061         if (!(mpvec = vector_alloc()))
1062                 return 1;
1063
1064         /*
1065          * probe for current path (from sysfs) and map (from dm) sets
1066          */
1067         path_discovery(vecs->pathvec, conf, DI_ALL);
1068
1069         vector_foreach_slot (vecs->pathvec, pp, i){
1070                 if (filter_path(conf, pp) > 0){
1071                         vector_del_slot(vecs->pathvec, i);
1072                         free_path(pp);
1073                         i--;
1074                 }
1075                 else
1076                         pp->checkint = conf->checkint;
1077         }
1078         if (map_discovery(vecs))
1079                 return 1;
1080
1081         /*
1082          * create new set of maps & push changed ones into dm
1083          */
1084         if (coalesce_paths(vecs, mpvec, NULL, 0))
1085                 return 1;
1086
1087         /*
1088          * may need to remove some maps which are no longer relevant
1089          * e.g., due to blacklist changes in conf file
1090          */
1091         if (coalesce_maps(vecs, mpvec))
1092                 return 1;
1093
1094         dm_lib_release();
1095
1096         sync_maps_state(mpvec);
1097
1098         /*
1099          * purge dm of old maps
1100          */
1101         remove_maps(vecs);
1102
1103         /*
1104          * save new set of maps formed by considering current path state
1105          */
1106         vector_free(vecs->mpvec);
1107         vecs->mpvec = mpvec;
1108
1109         /*
1110          * start dm event waiter threads for these new maps
1111          */
1112         vector_foreach_slot(vecs->mpvec, mpp, i) {
1113                 if (setup_multipath(vecs, mpp))
1114                         return 1;
1115                 if (start_waiters)
1116                         if (start_waiter_thread(mpp, vecs))
1117                                 return 1;
1118         }
1119         return 0;
1120 }
1121
1122 int
1123 reconfigure (struct vectors * vecs)
1124 {
1125         struct config * old = conf;
1126
1127         /*
1128          * free old map and path vectors ... they use old conf state
1129          */
1130         if (VECTOR_SIZE(vecs->mpvec))
1131                 remove_maps_and_stop_waiters(vecs);
1132
1133         if (VECTOR_SIZE(vecs->pathvec))
1134                 free_pathvec(vecs->pathvec, FREE_PATHS);
1135
1136         vecs->pathvec = NULL;
1137         conf = NULL;
1138
1139         if (load_config(DEFAULT_CONFIGFILE))
1140                 return 1;
1141
1142         conf->verbosity = old->verbosity;
1143
1144         if (!conf->checkint) {
1145                 conf->checkint = DEFAULT_CHECKINT;
1146                 conf->max_checkint = MAX_CHECKINT(conf->checkint);
1147         }
1148         configure(vecs, 1);
1149         free_config(old);
1150         return 0;
1151 }
1152
1153 static struct vectors *
1154 init_vecs (void)
1155 {
1156         struct vectors * vecs;
1157
1158         vecs = (struct vectors *)MALLOC(sizeof(struct vectors));
1159
1160         if (!vecs)
1161                 return NULL;
1162
1163         vecs->lock =
1164                 (pthread_mutex_t *)MALLOC(sizeof(pthread_mutex_t));
1165
1166         if (!vecs->lock)
1167                 goto out;
1168
1169         pthread_mutex_init(vecs->lock, NULL);
1170
1171         return vecs;
1172
1173 out:
1174         FREE(vecs);
1175         condlog(0, "failed to init paths");
1176         return NULL;
1177 }
1178
1179 static void *
1180 signal_set(int signo, void (*func) (int))
1181 {
1182         int r;
1183         struct sigaction sig;
1184         struct sigaction osig;
1185
1186         sig.sa_handler = func;
1187         sigemptyset(&sig.sa_mask);
1188         sig.sa_flags = 0;
1189
1190         r = sigaction(signo, &sig, &osig);
1191
1192         if (r < 0)
1193                 return (SIG_ERR);
1194         else
1195                 return (osig.sa_handler);
1196 }
1197
1198 static void
1199 sighup (int sig)
1200 {
1201         condlog(2, "reconfigure (SIGHUP)");
1202
1203         lock(gvecs->lock);
1204         reconfigure(gvecs);
1205         unlock(gvecs->lock);
1206
1207 #ifdef _DEBUG_
1208         dbg_free_final(NULL);
1209 #endif
1210 }
1211
1212 static void
1213 sigend (int sig)
1214 {
1215         exit_daemon(0);
1216 }
1217
1218 static void
1219 sigusr1 (int sig)
1220 {
1221         condlog(3, "SIGUSR1 received");
1222 }
1223
1224 static void
1225 signal_init(void)
1226 {
1227         signal_set(SIGHUP, sighup);
1228         signal_set(SIGUSR1, sigusr1);
1229         signal_set(SIGINT, sigend);
1230         signal_set(SIGTERM, sigend);
1231         signal(SIGPIPE, SIG_IGN);
1232 }
1233
1234 static void
1235 setscheduler (void)
1236 {
1237         int res;
1238         static struct sched_param sched_param = {
1239                 .sched_priority = 99
1240         };
1241
1242         res = sched_setscheduler (0, SCHED_RR, &sched_param);
1243
1244         if (res == -1)
1245                 condlog(LOG_WARNING, "Could not set SCHED_RR at priority 99");
1246         return;
1247 }
1248
1249 static void
1250 set_oom_adj (int val)
1251 {
1252         FILE *fp;
1253
1254         fp = fopen("/proc/self/oom_adj", "w");
1255
1256         if (!fp)
1257                 return;
1258
1259         fprintf(fp, "%i", val);
1260         fclose(fp);
1261 }
1262
1263 static int
1264 child (void * param)
1265 {
1266         pthread_t check_thr, uevent_thr, uxlsnr_thr;
1267         pthread_attr_t attr;
1268         struct vectors * vecs;
1269
1270         mlockall(MCL_CURRENT | MCL_FUTURE);
1271
1272         if (logsink)
1273                 log_thread_start();
1274
1275         condlog(2, "--------start up--------");
1276         condlog(2, "read " DEFAULT_CONFIGFILE);
1277
1278         if (load_config(DEFAULT_CONFIGFILE))
1279                 exit(1);
1280
1281         if (init_checkers()) {
1282                 condlog(0, "failed to initialize checkers");
1283                 exit(1);
1284         }
1285         if (init_prio()) {
1286                 condlog(0, "failed to initialize prioritizers");
1287                 exit(1);
1288         }
1289
1290         setlogmask(LOG_UPTO(conf->verbosity + 3));
1291
1292         /*
1293          * fill the voids left in the config file
1294          */
1295         if (!conf->checkint) {
1296                 conf->checkint = DEFAULT_CHECKINT;
1297                 conf->max_checkint = MAX_CHECKINT(conf->checkint);
1298         }
1299
1300         if (conf->max_fds) {
1301                 struct rlimit fd_limit;
1302                 if (conf->max_fds > 0) {
1303                         fd_limit.rlim_cur = conf->max_fds;
1304                         fd_limit.rlim_max = conf->max_fds;
1305                 }
1306                 else {
1307                         fd_limit.rlim_cur = RLIM_INFINITY;
1308                         fd_limit.rlim_max = RLIM_INFINITY;
1309                 }
1310                 if (setrlimit(RLIMIT_NOFILE, &fd_limit) < 0)
1311                         condlog(0, "can't set open fds limit to %d : %s\n",
1312                                 conf->max_fds, strerror(errno));
1313         }
1314
1315         if (pidfile_create(DEFAULT_PIDFILE, getpid())) {
1316                 if (logsink)
1317                         log_thread_stop();
1318
1319                 exit(1);
1320         }
1321         signal_init();
1322         setscheduler();
1323         set_oom_adj(-16);
1324         vecs = gvecs = init_vecs();
1325
1326         if (!vecs)
1327                 exit(1);
1328
1329         if (sysfs_init(conf->sysfs_dir, FILE_NAME_SIZE)) {
1330                 condlog(0, "can not find sysfs mount point");
1331                 exit(1);
1332         }
1333
1334         /*
1335          * fetch and configure both paths and multipaths
1336          */
1337         if (configure(vecs, 1)) {
1338                 condlog(0, "failure during configuration");
1339                 exit(1);
1340         }
1341
1342         /*
1343          * start threads
1344          */
1345         pthread_attr_init(&attr);
1346         pthread_attr_setstacksize(&attr, 64 * 1024);
1347         pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
1348
1349         pthread_create(&check_thr, &attr, checkerloop, vecs);
1350         pthread_create(&uevent_thr, &attr, ueventloop, vecs);
1351         pthread_create(&uxlsnr_thr, &attr, uxlsnrloop, vecs);
1352
1353         pthread_cond_wait(&exit_cond, &exit_mutex);
1354
1355         /*
1356          * exit path
1357          */
1358         lock(vecs->lock);
1359         remove_maps_and_stop_waiters(vecs);
1360         free_pathvec(vecs->pathvec, FREE_PATHS);
1361
1362         pthread_cancel(check_thr);
1363         pthread_cancel(uevent_thr);
1364         pthread_cancel(uxlsnr_thr);
1365
1366         sysfs_cleanup();
1367
1368         free_keys(keys);
1369         keys = NULL;
1370         free_handlers(handlers);
1371         handlers = NULL;
1372         free_polls();
1373
1374         unlock(vecs->lock);
1375         pthread_mutex_destroy(vecs->lock);
1376         FREE(vecs->lock);
1377         vecs->lock = NULL;
1378         FREE(vecs);
1379         vecs = NULL;
1380
1381         condlog(2, "--------shut down-------");
1382
1383         if (logsink)
1384                 log_thread_stop();
1385
1386         dm_lib_release();
1387         dm_lib_exit();
1388
1389         /*
1390          * Freeing config must be done after condlog() and dm_lib_exit(),
1391          * because logging functions like dlog() and dm_write_log()
1392          * reference the config.
1393          */
1394         free_config(conf);
1395         conf = NULL;
1396
1397 #ifdef _DEBUG_
1398         dbg_free_final(NULL);
1399 #endif
1400
1401         exit(0);
1402 }
1403
1404 static int
1405 daemonize(void)
1406 {
1407         int pid;
1408         int in_fd, out_fd;
1409
1410         if( (pid = fork()) < 0){
1411                 fprintf(stderr, "Failed first fork : %s\n", strerror(errno));
1412                 return -1;
1413         }
1414         else if (pid != 0)
1415                 return pid;
1416
1417         setsid();
1418
1419         if ( (pid = fork()) < 0)
1420                 fprintf(stderr, "Failed second fork : %s\n", strerror(errno));
1421         else if (pid != 0)
1422                 _exit(0);
1423
1424         in_fd = open("/dev/null", O_RDONLY);
1425         if (in_fd < 0){
1426                 fprintf(stderr, "cannot open /dev/null for input : %s\n",
1427                         strerror(errno));
1428                 _exit(0);
1429         }
1430         out_fd = open("/dev/console", O_WRONLY);
1431         if (out_fd < 0){
1432                 fprintf(stderr, "cannot open /dev/console for output : %s\n",
1433                         strerror(errno));
1434                 _exit(0);
1435         }
1436
1437         close(STDIN_FILENO);
1438         dup(in_fd);
1439         close(STDOUT_FILENO);
1440         dup(out_fd);
1441         close(STDERR_FILENO);
1442         dup(out_fd);
1443
1444         close(in_fd);
1445         close(out_fd);
1446         chdir("/");
1447         umask(0);
1448         return 0;
1449 }
1450
1451 int
1452 main (int argc, char *argv[])
1453 {
1454         extern char *optarg;
1455         extern int optind;
1456         int arg;
1457         int err;
1458
1459         logsink = 1;
1460         dm_init();
1461
1462         if (getuid() != 0) {
1463                 fprintf(stderr, "need to be root\n");
1464                 exit(1);
1465         }
1466
1467         /* make sure we don't lock any path */
1468         chdir("/");
1469         umask(umask(077) | 022);
1470
1471         conf = alloc_config();
1472
1473         if (!conf)
1474                 exit(1);
1475
1476         while ((arg = getopt(argc, argv, ":dv:k::")) != EOF ) {
1477         switch(arg) {
1478                 case 'd':
1479                         logsink = 0;
1480                         //debug=1; /* ### comment me out ### */
1481                         break;
1482                 case 'v':
1483                         if (sizeof(optarg) > sizeof(char *) ||
1484                             !isdigit(optarg[0]))
1485                                 exit(1);
1486
1487                         conf->verbosity = atoi(optarg);
1488                         break;
1489                 case 'k':
1490                         uxclnt(optarg);
1491                         exit(0);
1492                 default:
1493                         ;
1494                 }
1495         }
1496         if (optind < argc) {
1497                 char cmd[CMDSIZE];
1498                 char * s = cmd;
1499                 char * c = s;
1500
1501                 while (optind < argc) {
1502                         if (strchr(argv[optind], ' '))
1503                                 c += snprintf(c, s + CMDSIZE - c, "\"%s\" ", argv[optind]);
1504                         else
1505                                 c += snprintf(c, s + CMDSIZE - c, "%s ", argv[optind]);
1506                         optind++;
1507                 }
1508                 c += snprintf(c, s + CMDSIZE - c, "\n");
1509                 uxclnt(s);
1510                 exit(0);
1511         }
1512
1513         if (!logsink)
1514                 err = 0;
1515         else
1516                 err = daemonize();
1517
1518         if (err < 0)
1519                 /* error */
1520                 exit(1);
1521         else if (err > 0)
1522                 /* parent dies */
1523                 exit(0);
1524         else
1525                 /* child lives */
1526                 return (child(NULL));
1527 }
1528