manager.c

   1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <assert.h>
  23 #include <errno.h>
  24 #include <string.h>
  25 #include <sys/epoll.h>
  26 #include <signal.h>
  27 #include <sys/signalfd.h>
  28 #include <sys/wait.h>
  29 #include <unistd.h>
  30 #include <utmpx.h>
  31 #include <sys/poll.h>
  32 #include <sys/reboot.h>
  33 #include <sys/ioctl.h>
  34 #include <linux/kd.h>
  35 #include <libcgroup.h>
  36 #include <termios.h>
  37 #include <fcntl.h>
  38 #include <sys/types.h>
  39 #include <sys/stat.h>
  40
  41 #include "manager.h"
  42 #include "hashmap.h"
  43 #include "macro.h"
  44 #include "strv.h"
  45 #include "log.h"
  46 #include "util.h"
  47 #include "ratelimit.h"
  48 #include "cgroup.h"
  49 #include "mount-setup.h"
  50 #include "utmp-wtmp.h"
  51 #include "unit-name.h"
  52 #include "dbus-unit.h"
  53 #include "dbus-job.h"
  54
  55 static int enable_special_signals(Manager *m) {
  56         char fd;
  57
  58         assert(m);
  59
  60         /* Enable that we get SIGINT on control-alt-del */
  61         if (reboot(RB_DISABLE_CAD) < 0)
  62                 log_warning("Failed to enable ctrl-alt-del handling: %m");
  63
  64         if ((fd = open_terminal("/dev/tty0", O_RDWR)) < 0)
  65                 log_warning("Failed to open /dev/tty0: %m");
  66         else {
  67                 /* Enable that we get SIGWINCH on kbrequest */
  68                 if (ioctl(fd, KDSIGACCEPT, SIGWINCH) < 0)
  69                         log_warning("Failed to enable kbrequest handling: %s", strerror(errno));
  70
  71                 close_nointr_nofail(fd);
  72         }
  73
  74         return 0;
  75 }
  76
  77 static int manager_setup_signals(Manager *m) {
  78         sigset_t mask;
  79         struct epoll_event ev;
  80         struct sigaction sa;
  81
  82         assert(m);
  83
  84         /* We are not interested in SIGSTOP and friends. */
  85         zero(sa);
  86         sa.sa_handler = SIG_DFL;
  87         sa.sa_flags = SA_NOCLDSTOP|SA_RESTART;
  88         assert_se(sigaction(SIGCHLD, &sa, NULL) == 0);
  89
  90         assert_se(sigemptyset(&mask) == 0);
  91         assert_se(sigaddset(&mask, SIGCHLD) == 0);
  92         assert_se(sigaddset(&mask, SIGTERM) == 0);
  93         assert_se(sigaddset(&mask, SIGHUP) == 0);
  94         assert_se(sigaddset(&mask, SIGUSR1) == 0);
  95         assert_se(sigaddset(&mask, SIGUSR2) == 0);
  96         assert_se(sigaddset(&mask, SIGINT) == 0);   /* Kernel sends us this on control-alt-del */
  97         assert_se(sigaddset(&mask, SIGWINCH) == 0); /* Kernel sends us this on kbrequest (alt-arrowup) */
  98         assert_se(sigaddset(&mask, SIGPWR) == 0);   /* Some kernel drivers and upsd send us this on power failure */
  99         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
 100
 101         m->signal_watch.type = WATCH_SIGNAL;
 102         if ((m->signal_watch.fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
 103                 return -errno;
 104
 105         zero(ev);
 106         ev.events = EPOLLIN;
 107         ev.data.ptr = &m->signal_watch;
 108
 109         if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_watch.fd, &ev) < 0)
 110                 return -errno;
 111
 112         if (m->running_as == MANAGER_INIT)
 113                 return enable_special_signals(m);
 114
 115         return 0;
 116 }
 117
 118 static char** session_dirs(void) {
 119         const char *home, *e;
 120         char *config_home = NULL, *data_home = NULL;
 121         char **config_dirs = NULL, **data_dirs = NULL;
 122         char **r = NULL, **t;
 123
 124         /* Implement the mechanisms defined in
 125          *
 126          * http://standards.freedesktop.org/basedir-spec/basedir-spec-0.6.html
 127          *
 128          * We look in both the config and the data dirs because we
 129          * want to encourage that distributors ship their unit files
 130          * as data, and allow overriding as configuration.
 131          */
 132
 133         home = getenv("HOME");
 134
 135         if ((e = getenv("XDG_CONFIG_HOME"))) {
 136                 if (asprintf(&config_home, "%s/systemd/session", e) < 0)
 137                         goto fail;
 138
 139         } else if (home) {
 140                 if (asprintf(&config_home, "%s/.config/systemd/session", home) < 0)
 141                         goto fail;
 142         }
 143
 144         if ((e = getenv("XDG_CONFIG_DIRS")))
 145                 config_dirs = strv_split(e, ":");
 146         else
 147                 config_dirs = strv_new("/etc/xdg", NULL);
 148
 149         if (!config_dirs)
 150                 goto fail;
 151
 152         if ((e = getenv("XDG_DATA_HOME"))) {
 153                 if (asprintf(&data_home, "%s/systemd/session", e) < 0)
 154                         goto fail;
 155
 156         } else if (home) {
 157                 if (asprintf(&data_home, "%s/.local/share/systemd/session", home) < 0)
 158                         goto fail;
 159         }
 160
 161         if ((e = getenv("XDG_DATA_DIRS")))
 162                 data_dirs = strv_split(e, ":");
 163         else
 164                 data_dirs = strv_new("/usr/local/share", "/usr/share", NULL);
 165
 166         if (!data_dirs)
 167                 goto fail;
 168
 169         /* Now merge everything we found. */
 170         if (config_home) {
 171                 if (!(t = strv_append(r, config_home)))
 172                         goto fail;
 173                 strv_free(r);
 174                 r = t;
 175         }
 176
 177         if (!(t = strv_merge_concat(r, config_dirs, "/systemd/session")))
 178                 goto finish;
 179         strv_free(r);
 180         r = t;
 181
 182         if (!(t = strv_append(r, SESSION_CONFIG_UNIT_PATH)))
 183                 goto fail;
 184         strv_free(r);
 185         r = t;
 186
 187         if (data_home) {
 188                 if (!(t = strv_append(r, data_home)))
 189                         goto fail;
 190                 strv_free(r);
 191                 r = t;
 192         }
 193
 194         if (!(t = strv_merge_concat(r, data_dirs, "/systemd/session")))
 195                 goto fail;
 196         strv_free(r);
 197         r = t;
 198
 199         if (!(t = strv_append(r, SESSION_DATA_UNIT_PATH)))
 200                 goto fail;
 201         strv_free(r);
 202         r = t;
 203
 204         if (!strv_path_make_absolute_cwd(r))
 205             goto fail;
 206
 207 finish:
 208         free(config_home);
 209         strv_free(config_dirs);
 210         free(data_home);
 211         strv_free(data_dirs);
 212
 213         return r;
 214
 215 fail:
 216         strv_free(r);
 217         r = NULL;
 218         goto finish;
 219 }
 220
 221 static int manager_find_paths(Manager *m) {
 222         const char *e;
 223         char *t;
 224
 225         assert(m);
 226
 227         /* First priority is whatever has been passed to us via env
 228          * vars */
 229         if ((e = getenv("SYSTEMD_UNIT_PATH")))
 230                 if (!(m->unit_path = split_path_and_make_absolute(e)))
 231                         return -ENOMEM;
 232
 233         if (strv_isempty(m->unit_path)) {
 234
 235                 /* Nothing is set, so let's figure something out. */
 236                 strv_free(m->unit_path);
 237
 238                 if (m->running_as == MANAGER_SESSION) {
 239                         if (!(m->unit_path = session_dirs()))
 240                                 return -ENOMEM;
 241                 } else
 242                         if (!(m->unit_path = strv_new(
 243                                               SYSTEM_CONFIG_UNIT_PATH,  /* /etc/systemd/system/ */
 244                                               SYSTEM_DATA_UNIT_PATH,    /* /lib/systemd/system/ */
 245                                               NULL)))
 246                                 return -ENOMEM;
 247         }
 248
 249         if (m->running_as == MANAGER_INIT) {
 250                 /* /etc/init.d/ compativility does not matter to users */
 251
 252                 if ((e = getenv("SYSTEMD_SYSVINIT_PATH")))
 253                         if (!(m->sysvinit_path = split_path_and_make_absolute(e)))
 254                                 return -ENOMEM;
 255
 256                 if (strv_isempty(m->sysvinit_path)) {
 257                         strv_free(m->sysvinit_path);
 258
 259                         if (!(m->sysvinit_path = strv_new(
 260                                               SYSTEM_SYSVINIT_PATH,     /* /etc/init.d/ */
 261                                               NULL)))
 262                                 return -ENOMEM;
 263                 }
 264
 265                 if ((e = getenv("SYSTEMD_SYSVRCND_PATH")))
 266                         if (!(m->sysvrcnd_path = split_path_and_make_absolute(e)))
 267                                 return -ENOMEM;
 268
 269                 if (strv_isempty(m->sysvrcnd_path)) {
 270                         strv_free(m->sysvrcnd_path);
 271
 272                         if (!(m->sysvrcnd_path = strv_new(
 273                                               SYSTEM_SYSVRCND_PATH,     /* /etc/rcN.d/ */
 274                                               NULL)))
 275                                 return -ENOMEM;
 276                 }
 277         }
 278
 279         strv_uniq(m->unit_path);
 280         strv_uniq(m->sysvinit_path);
 281         strv_uniq(m->sysvrcnd_path);
 282
 283         assert(!strv_isempty(m->unit_path));
 284         if (!(t = strv_join(m->unit_path, "\n\t")))
 285                 return -ENOMEM;
 286         log_debug("Looking for unit files in:\n\t%s", t);
 287         free(t);
 288
 289         if (!strv_isempty(m->sysvinit_path)) {
 290
 291                 if (!(t = strv_join(m->sysvinit_path, "\n\t")))
 292                         return -ENOMEM;
 293
 294                 log_debug("Looking for SysV init scripts in:\n\t%s", t);
 295                 free(t);
 296         } else
 297                 log_debug("Ignoring SysV init scripts.");
 298
 299         if (!strv_isempty(m->sysvrcnd_path)) {
 300
 301                 if (!(t = strv_join(m->sysvrcnd_path, "\n\t")))
 302                         return -ENOMEM;
 303
 304                 log_debug("Looking for SysV rcN.d links in:\n\t%s", t);
 305                 free(t);
 306         } else
 307                 log_debug("Ignoring SysV rcN.d links.");
 308
 309         return 0;
 310 }
 311
 312 int manager_new(ManagerRunningAs running_as, bool confirm_spawn, Manager **_m) {
 313         Manager *m;
 314         int r = -ENOMEM;
 315
 316         assert(_m);
 317         assert(running_as >= 0);
 318         assert(running_as < _MANAGER_RUNNING_AS_MAX);
 319
 320         if (!(m = new0(Manager, 1)))
 321                 return -ENOMEM;
 322
 323         m->boot_timestamp = now(CLOCK_REALTIME);
 324
 325         m->running_as = running_as;
 326         m->confirm_spawn = confirm_spawn;
 327         m->name_data_slot = -1;
 328         m->exit_code = _MANAGER_EXIT_CODE_INVALID;
 329
 330         m->signal_watch.fd = m->mount_watch.fd = m->udev_watch.fd = m->epoll_fd = m->dev_autofs_fd = -1;
 331         m->current_job_id = 1; /* start as id #1, so that we can leave #0 around as "null-like" value */
 332
 333         if (!(m->units = hashmap_new(string_hash_func, string_compare_func)))
 334                 goto fail;
 335
 336         if (!(m->jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
 337                 goto fail;
 338
 339         if (!(m->transaction_jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
 340                 goto fail;
 341
 342         if (!(m->watch_pids = hashmap_new(trivial_hash_func, trivial_compare_func)))
 343                 goto fail;
 344
 345         if (!(m->cgroup_bondings = hashmap_new(string_hash_func, string_compare_func)))
 346                 goto fail;
 347
 348         if (!(m->watch_bus = hashmap_new(string_hash_func, string_compare_func)))
 349                 goto fail;
 350
 351         if ((m->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0)
 352                 goto fail;
 353
 354         if ((r = manager_find_paths(m)) < 0)
 355                 goto fail;
 356
 357         if ((r = manager_setup_signals(m)) < 0)
 358                 goto fail;
 359
 360         if ((r = manager_setup_cgroup(m)) < 0)
 361                 goto fail;
 362
 363         /* Try to connect to the busses, if possible. */
 364         if ((r = bus_init_system(m)) < 0 ||
 365             (r = bus_init_api(m)) < 0)
 366                 goto fail;
 367
 368         *_m = m;
 369         return 0;
 370
 371 fail:
 372         manager_free(m);
 373         return r;
 374 }
 375
 376 static unsigned manager_dispatch_cleanup_queue(Manager *m) {
 377         Meta *meta;
 378         unsigned n = 0;
 379
 380         assert(m);
 381
 382         while ((meta = m->cleanup_queue)) {
 383                 assert(meta->in_cleanup_queue);
 384
 385                 unit_free(UNIT(meta));
 386                 n++;
 387         }
 388
 389         return n;
 390 }
 391
 392 static void manager_clear_jobs_and_units(Manager *m) {
 393         Job *j;
 394         Unit *u;
 395
 396         assert(m);
 397
 398         while ((j = hashmap_first(m->transaction_jobs)))
 399                 job_free(j);
 400
 401         while ((u = hashmap_first(m->units)))
 402                 unit_free(u);
 403 }
 404
 405 void manager_free(Manager *m) {
 406         UnitType c;
 407
 408         assert(m);
 409
 410         manager_clear_jobs_and_units(m);
 411
 412         for (c = 0; c < _UNIT_TYPE_MAX; c++)
 413                 if (unit_vtable[c]->shutdown)
 414                         unit_vtable[c]->shutdown(m);
 415
 416         /* If we reexecute ourselves, we keep the root cgroup
 417          * around */
 418         manager_shutdown_cgroup(m, m->exit_code != MANAGER_REEXECUTE);
 419
 420         bus_done_api(m);
 421         bus_done_system(m);
 422
 423         hashmap_free(m->units);
 424         hashmap_free(m->jobs);
 425         hashmap_free(m->transaction_jobs);
 426         hashmap_free(m->watch_pids);
 427         hashmap_free(m->watch_bus);
 428
 429         if (m->epoll_fd >= 0)
 430                 close_nointr_nofail(m->epoll_fd);
 431         if (m->signal_watch.fd >= 0)
 432                 close_nointr_nofail(m->signal_watch.fd);
 433
 434         strv_free(m->unit_path);
 435         strv_free(m->sysvinit_path);
 436         strv_free(m->sysvrcnd_path);
 437
 438         free(m->cgroup_controller);
 439         free(m->cgroup_hierarchy);
 440
 441         hashmap_free(m->cgroup_bondings);
 442
 443         free(m);
 444 }
 445
 446 int manager_enumerate(Manager *m) {
 447         int r = 0, q;
 448         UnitType c;
 449
 450         assert(m);
 451
 452         /* Let's ask every type to load all units from disk/kernel
 453          * that it might know */
 454         for (c = 0; c < _UNIT_TYPE_MAX; c++)
 455                 if (unit_vtable[c]->enumerate)
 456                         if ((q = unit_vtable[c]->enumerate(m)) < 0)
 457                                 r = q;
 458
 459         manager_dispatch_load_queue(m);
 460         return r;
 461 }
 462
 463 int manager_coldplug(Manager *m) {
 464         int r = 0, q;
 465         Iterator i;
 466         Unit *u;
 467         char *k;
 468
 469         assert(m);
 470
 471         /* Then, let's set up their initial state. */
 472         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
 473
 474                 /* ignore aliases */
 475                 if (u->meta.id != k)
 476                         continue;
 477
 478                 if (UNIT_VTABLE(u)->coldplug)
 479                         if ((q = UNIT_VTABLE(u)->coldplug(u)) < 0)
 480                                 r = q;
 481         }
 482
 483         return r;
 484 }
 485
 486 int manager_startup(Manager *m, FILE *serialization, FDSet *fds) {
 487         int r, q;
 488
 489         assert(m);
 490
 491         /* First, enumerate what we can from all config files */
 492         r = manager_enumerate(m);
 493
 494         /* Second, deserialize if there is something to deserialize */
 495         if (serialization)
 496                 if ((q = manager_deserialize(m, serialization, fds)) < 0)
 497                         r = q;
 498
 499         /* Third, fire things up! */
 500         if ((q = manager_coldplug(m)) < 0)
 501                 r = q;
 502
 503         /* Now that the initial devices are available, let's see if we
 504          * can write the utmp file */
 505         manager_write_utmp_reboot(m);
 506
 507         return r;
 508 }
 509
 510 static void transaction_delete_job(Manager *m, Job *j, bool delete_dependencies) {
 511         assert(m);
 512         assert(j);
 513
 514         /* Deletes one job from the transaction */
 515
 516         manager_transaction_unlink_job(m, j, delete_dependencies);
 517
 518         if (!j->installed)
 519                 job_free(j);
 520 }
 521
 522 static void transaction_delete_unit(Manager *m, Unit *u) {
 523         Job *j;
 524
 525         /* Deletes all jobs associated with a certain unit from the
 526          * transaction */
 527
 528         while ((j = hashmap_get(m->transaction_jobs, u)))
 529                 transaction_delete_job(m, j, true);
 530 }
 531
 532 static void transaction_clean_dependencies(Manager *m) {
 533         Iterator i;
 534         Job *j;
 535
 536         assert(m);
 537
 538         /* Drops all dependencies of all installed jobs */
 539
 540         HASHMAP_FOREACH(j, m->jobs, i) {
 541                 while (j->subject_list)
 542                         job_dependency_free(j->subject_list);
 543                 while (j->object_list)
 544                         job_dependency_free(j->object_list);
 545         }
 546
 547         assert(!m->transaction_anchor);
 548 }
 549
 550 static void transaction_abort(Manager *m) {
 551         Job *j;
 552
 553         assert(m);
 554
 555         while ((j = hashmap_first(m->transaction_jobs)))
 556                 if (j->installed)
 557                         transaction_delete_job(m, j, true);
 558                 else
 559                         job_free(j);
 560
 561         assert(hashmap_isempty(m->transaction_jobs));
 562
 563         transaction_clean_dependencies(m);
 564 }
 565
 566 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
 567         JobDependency *l;
 568
 569         assert(m);
 570
 571         /* A recursive sweep through the graph that marks all units
 572          * that matter to the anchor job, i.e. are directly or
 573          * indirectly a dependency of the anchor job via paths that
 574          * are fully marked as mattering. */
 575
 576         if (j)
 577                 l = j->subject_list;
 578         else
 579                 l = m->transaction_anchor;
 580
 581         LIST_FOREACH(subject, l, l) {
 582
 583                 /* This link does not matter */
 584                 if (!l->matters)
 585                         continue;
 586
 587                 /* This unit has already been marked */
 588                 if (l->object->generation == generation)
 589                         continue;
 590
 591                 l->object->matters_to_anchor = true;
 592                 l->object->generation = generation;
 593
 594                 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
 595         }
 596 }
 597
 598 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
 599         JobDependency *l, *last;
 600
 601         assert(j);
 602         assert(other);
 603         assert(j->unit == other->unit);
 604         assert(!j->installed);
 605
 606         /* Merges 'other' into 'j' and then deletes j. */
 607
 608         j->type = t;
 609         j->state = JOB_WAITING;
 610         j->override = j->override || other->override;
 611
 612         j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
 613
 614         /* Patch us in as new owner of the JobDependency objects */
 615         last = NULL;
 616         LIST_FOREACH(subject, l, other->subject_list) {
 617                 assert(l->subject == other);
 618                 l->subject = j;
 619                 last = l;
 620         }
 621
 622         /* Merge both lists */
 623         if (last) {
 624                 last->subject_next = j->subject_list;
 625                 if (j->subject_list)
 626                         j->subject_list->subject_prev = last;
 627                 j->subject_list = other->subject_list;
 628         }
 629
 630         /* Patch us in as new owner of the JobDependency objects */
 631         last = NULL;
 632         LIST_FOREACH(object, l, other->object_list) {
 633                 assert(l->object == other);
 634                 l->object = j;
 635                 last = l;
 636         }
 637
 638         /* Merge both lists */
 639         if (last) {
 640                 last->object_next = j->object_list;
 641                 if (j->object_list)
 642                         j->object_list->object_prev = last;
 643                 j->object_list = other->object_list;
 644         }
 645
 646         /* Kill the other job */
 647         other->subject_list = NULL;
 648         other->object_list = NULL;
 649         transaction_delete_job(m, other, true);
 650 }
 651
 652 static int delete_one_unmergeable_job(Manager *m, Job *j) {
 653         Job *k;
 654
 655         assert(j);
 656
 657         /* Tries to delete one item in the linked list
 658          * j->transaction_next->transaction_next->... that conflicts
 659          * whith another one, in an attempt to make an inconsistent
 660          * transaction work. */
 661
 662         /* We rely here on the fact that if a merged with b does not
 663          * merge with c, either a or b merge with c neither */
 664         LIST_FOREACH(transaction, j, j)
 665                 LIST_FOREACH(transaction, k, j->transaction_next) {
 666                         Job *d;
 667
 668                         /* Is this one mergeable? Then skip it */
 669                         if (job_type_is_mergeable(j->type, k->type))
 670                                 continue;
 671
 672                         /* Ok, we found two that conflict, let's see if we can
 673                          * drop one of them */
 674                         if (!j->matters_to_anchor)
 675                                 d = j;
 676                         else if (!k->matters_to_anchor)
 677                                 d = k;
 678                         else
 679                                 return -ENOEXEC;
 680
 681                         /* Ok, we can drop one, so let's do so. */
 682                         log_debug("Trying to fix job merging by deleting job %s/%s", d->unit->meta.id, job_type_to_string(d->type));
 683                         transaction_delete_job(m, d, true);
 684                         return 0;
 685                 }
 686
 687         return -EINVAL;
 688 }
 689
 690 static int transaction_merge_jobs(Manager *m) {
 691         Job *j;
 692         Iterator i;
 693         int r;
 694
 695         assert(m);
 696
 697         /* First step, check whether any of the jobs for one specific
 698          * task conflict. If so, try to drop one of them. */
 699         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 700                 JobType t;
 701                 Job *k;
 702
 703                 t = j->type;
 704                 LIST_FOREACH(transaction, k, j->transaction_next) {
 705                         if ((r = job_type_merge(&t, k->type)) >= 0)
 706                                 continue;
 707
 708                         /* OK, we could not merge all jobs for this
 709                          * action. Let's see if we can get rid of one
 710                          * of them */
 711
 712                         if ((r = delete_one_unmergeable_job(m, j)) >= 0)
 713                                 /* Ok, we managed to drop one, now
 714                                  * let's ask our callers to call us
 715                                  * again after garbage collecting */
 716                                 return -EAGAIN;
 717
 718                         /* We couldn't merge anything. Failure */
 719                         return r;
 720                 }
 721         }
 722
 723         /* Second step, merge the jobs. */
 724         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 725                 JobType t = j->type;
 726                 Job *k;
 727
 728                 /* Merge all transactions */
 729                 LIST_FOREACH(transaction, k, j->transaction_next)
 730                         assert_se(job_type_merge(&t, k->type) == 0);
 731
 732                 /* If an active job is mergeable, merge it too */
 733                 if (j->unit->meta.job)
 734                         job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
 735
 736                 while ((k = j->transaction_next)) {
 737                         if (j->installed) {
 738                                 transaction_merge_and_delete_job(m, k, j, t);
 739                                 j = k;
 740                         } else
 741                                 transaction_merge_and_delete_job(m, j, k, t);
 742                 }
 743
 744                 assert(!j->transaction_next);
 745                 assert(!j->transaction_prev);
 746         }
 747
 748         return 0;
 749 }
 750
 751 static void transaction_drop_redundant(Manager *m) {
 752         bool again;
 753
 754         assert(m);
 755
 756         /* Goes through the transaction and removes all jobs that are
 757          * a noop */
 758
 759         do {
 760                 Job *j;
 761                 Iterator i;
 762
 763                 again = false;
 764
 765                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 766                         bool changes_something = false;
 767                         Job *k;
 768
 769                         LIST_FOREACH(transaction, k, j) {
 770
 771                                 if (!job_is_anchor(k) &&
 772                                     job_type_is_redundant(k->type, unit_active_state(k->unit)))
 773                                         continue;
 774
 775                                 changes_something = true;
 776                                 break;
 777                         }
 778
 779                         if (changes_something)
 780                                 continue;
 781
 782                         log_debug("Found redundant job %s/%s, dropping.", j->unit->meta.id, job_type_to_string(j->type));
 783                         transaction_delete_job(m, j, false);
 784                         again = true;
 785                         break;
 786                 }
 787
 788         } while (again);
 789 }
 790
 791 static bool unit_matters_to_anchor(Unit *u, Job *j) {
 792         assert(u);
 793         assert(!j->transaction_prev);
 794
 795         /* Checks whether at least one of the jobs for this unit
 796          * matters to the anchor. */
 797
 798         LIST_FOREACH(transaction, j, j)
 799                 if (j->matters_to_anchor)
 800                         return true;
 801
 802         return false;
 803 }
 804
 805 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation) {
 806         Iterator i;
 807         Unit *u;
 808         int r;
 809
 810         assert(m);
 811         assert(j);
 812         assert(!j->transaction_prev);
 813
 814         /* Does a recursive sweep through the ordering graph, looking
 815          * for a cycle. If we find cycle we try to break it. */
 816
 817         /* Did we find a cycle? */
 818         if (j->marker && j->generation == generation) {
 819                 Job *k;
 820
 821                 /* So, we already have been here. We have a
 822                  * cycle. Let's try to break it. We go backwards in
 823                  * our path and try to find a suitable job to
 824                  * remove. We use the marker to find our way back,
 825                  * since smart how we are we stored our way back in
 826                  * there. */
 827
 828                 log_debug("Found ordering cycle on %s/%s", j->unit->meta.id, job_type_to_string(j->type));
 829
 830                 for (k = from; k; k = (k->generation == generation ? k->marker : NULL)) {
 831
 832                         log_debug("Walked on cycle path to %s/%s", k->unit->meta.id, job_type_to_string(k->type));
 833
 834                         if (!k->installed &&
 835                             !unit_matters_to_anchor(k->unit, k)) {
 836                                 /* Ok, we can drop this one, so let's
 837                                  * do so. */
 838                                 log_debug("Breaking order cycle by deleting job %s/%s", k->unit->meta.id, job_type_to_string(k->type));
 839                                 transaction_delete_unit(m, k->unit);
 840                                 return -EAGAIN;
 841                         }
 842
 843                         /* Check if this in fact was the beginning of
 844                          * the cycle */
 845                         if (k == j)
 846                                 break;
 847                 }
 848
 849                 log_debug("Unable to break cycle");
 850
 851                 return -ENOEXEC;
 852         }
 853
 854         /* Make the marker point to where we come from, so that we can
 855          * find our way backwards if we want to break a cycle */
 856         j->marker = from;
 857         j->generation = generation;
 858
 859         /* We assume that the the dependencies are bidirectional, and
 860          * hence can ignore UNIT_AFTER */
 861         SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
 862                 Job *o;
 863
 864                 /* Is there a job for this unit? */
 865                 if (!(o = hashmap_get(m->transaction_jobs, u)))
 866
 867                         /* Ok, there is no job for this in the
 868                          * transaction, but maybe there is already one
 869                          * running? */
 870                         if (!(o = u->meta.job))
 871                                 continue;
 872
 873                 if ((r = transaction_verify_order_one(m, o, j, generation)) < 0)
 874                         return r;
 875         }
 876
 877         /* Ok, let's backtrack, and remember that this entry is not on
 878          * our path anymore. */
 879         j->marker = NULL;
 880
 881         return 0;
 882 }
 883
 884 static int transaction_verify_order(Manager *m, unsigned *generation) {
 885         Job *j;
 886         int r;
 887         Iterator i;
 888
 889         assert(m);
 890         assert(generation);
 891
 892         /* Check if the ordering graph is cyclic. If it is, try to fix
 893          * that up by dropping one of the jobs. */
 894
 895         HASHMAP_FOREACH(j, m->transaction_jobs, i)
 896                 if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0)
 897                         return r;
 898
 899         return 0;
 900 }
 901
 902 static void transaction_collect_garbage(Manager *m) {
 903         bool again;
 904
 905         assert(m);
 906
 907         /* Drop jobs that are not required by any other job */
 908
 909         do {
 910                 Iterator i;
 911                 Job *j;
 912
 913                 again = false;
 914
 915                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 916                         if (j->object_list)
 917                                 continue;
 918
 919                         log_debug("Garbage collecting job %s/%s", j->unit->meta.id, job_type_to_string(j->type));
 920                         transaction_delete_job(m, j, true);
 921                         again = true;
 922                         break;
 923                 }
 924
 925         } while (again);
 926 }
 927
 928 static int transaction_is_destructive(Manager *m, JobMode mode) {
 929         Iterator i;
 930         Job *j;
 931
 932         assert(m);
 933
 934         /* Checks whether applying this transaction means that
 935          * existing jobs would be replaced */
 936
 937         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 938
 939                 /* Assume merged */
 940                 assert(!j->transaction_prev);
 941                 assert(!j->transaction_next);
 942
 943                 if (j->unit->meta.job &&
 944                     j->unit->meta.job != j &&
 945                     !job_type_is_superset(j->type, j->unit->meta.job->type))
 946                         return -EEXIST;
 947         }
 948
 949         return 0;
 950 }
 951
 952 static void transaction_minimize_impact(Manager *m) {
 953         bool again;
 954         assert(m);
 955
 956         /* Drops all unnecessary jobs that reverse already active jobs
 957          * or that stop a running service. */
 958
 959         do {
 960                 Job *j;
 961                 Iterator i;
 962
 963                 again = false;
 964
 965                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 966                         LIST_FOREACH(transaction, j, j) {
 967                                 bool stops_running_service, changes_existing_job;
 968
 969                                 /* If it matters, we shouldn't drop it */
 970                                 if (j->matters_to_anchor)
 971                                         continue;
 972
 973                                 /* Would this stop a running service?
 974                                  * Would this change an existing job?
 975                                  * If so, let's drop this entry */
 976
 977                                 stops_running_service =
 978                                         j->type == JOB_STOP && UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(j->unit));
 979
 980                                 changes_existing_job =
 981                                         j->unit->meta.job && job_type_is_conflicting(j->type, j->unit->meta.job->state);
 982
 983                                 if (!stops_running_service && !changes_existing_job)
 984                                         continue;
 985
 986                                 if (stops_running_service)
 987                                         log_debug("%s/%s would stop a running service.", j->unit->meta.id, job_type_to_string(j->type));
 988
 989                                 if (changes_existing_job)
 990                                         log_debug("%s/%s would change existing job.", j->unit->meta.id, job_type_to_string(j->type));
 991
 992                                 /* Ok, let's get rid of this */
 993                                 log_debug("Deleting %s/%s to minimize impact.", j->unit->meta.id, job_type_to_string(j->type));
 994
 995                                 transaction_delete_job(m, j, true);
 996                                 again = true;
 997                                 break;
 998                         }
 999
1000                         if (again)
1001                                 break;
1002                 }
1003
1004         } while (again);
1005 }
1006
1007 static int transaction_apply(Manager *m, JobMode mode) {
1008         Iterator i;
1009         Job *j;
1010         int r;
1011
1012         /* Moves the transaction jobs to the set of active jobs */
1013
1014         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1015                 /* Assume merged */
1016                 assert(!j->transaction_prev);
1017                 assert(!j->transaction_next);
1018
1019                 if (j->installed)
1020                         continue;
1021
1022                 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
1023                         goto rollback;
1024         }
1025
1026         while ((j = hashmap_steal_first(m->transaction_jobs))) {
1027                 if (j->installed)
1028                         continue;
1029
1030                 if (j->unit->meta.job)
1031                         job_free(j->unit->meta.job);
1032
1033                 j->unit->meta.job = j;
1034                 j->installed = true;
1035
1036                 /* We're fully installed. Now let's free data we don't
1037                  * need anymore. */
1038
1039                 assert(!j->transaction_next);
1040                 assert(!j->transaction_prev);
1041
1042                 job_add_to_run_queue(j);
1043                 job_add_to_dbus_queue(j);
1044         }
1045
1046         /* As last step, kill all remaining job dependencies. */
1047         transaction_clean_dependencies(m);
1048
1049         return 0;
1050
1051 rollback:
1052
1053         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1054                 if (j->installed)
1055                         continue;
1056
1057                 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
1058         }
1059
1060         return r;
1061 }
1062
1063 static int transaction_activate(Manager *m, JobMode mode) {
1064         int r;
1065         unsigned generation = 1;
1066
1067         assert(m);
1068
1069         /* This applies the changes recorded in transaction_jobs to
1070          * the actual list of jobs, if possible. */
1071
1072         /* First step: figure out which jobs matter */
1073         transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
1074
1075         /* Second step: Try not to stop any running services if
1076          * we don't have to. Don't try to reverse running
1077          * jobs if we don't have to. */
1078         transaction_minimize_impact(m);
1079
1080         /* Third step: Drop redundant jobs */
1081         transaction_drop_redundant(m);
1082
1083         for (;;) {
1084                 /* Fourth step: Let's remove unneeded jobs that might
1085                  * be lurking. */
1086                 transaction_collect_garbage(m);
1087
1088                 /* Fifth step: verify order makes sense and correct
1089                  * cycles if necessary and possible */
1090                 if ((r = transaction_verify_order(m, &generation)) >= 0)
1091                         break;
1092
1093                 if (r != -EAGAIN) {
1094                         log_debug("Requested transaction contains an unfixable cyclic ordering dependency: %s", strerror(-r));
1095                         goto rollback;
1096                 }
1097
1098                 /* Let's see if the resulting transaction ordering
1099                  * graph is still cyclic... */
1100         }
1101
1102         for (;;) {
1103                 /* Sixth step: let's drop unmergeable entries if
1104                  * necessary and possible, merge entries we can
1105                  * merge */
1106                 if ((r = transaction_merge_jobs(m)) >= 0)
1107                         break;
1108
1109                 if (r != -EAGAIN) {
1110                         log_debug("Requested transaction contains unmergable jobs: %s", strerror(-r));
1111                         goto rollback;
1112                 }
1113
1114                 /* Seventh step: an entry got dropped, let's garbage
1115                  * collect its dependencies. */
1116                 transaction_collect_garbage(m);
1117
1118                 /* Let's see if the resulting transaction still has
1119                  * unmergeable entries ... */
1120         }
1121
1122         /* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */
1123         transaction_drop_redundant(m);
1124
1125         /* Ninth step: check whether we can actually apply this */
1126         if (mode == JOB_FAIL)
1127                 if ((r = transaction_is_destructive(m, mode)) < 0) {
1128                         log_debug("Requested transaction contradicts existing jobs: %s", strerror(-r));
1129                         goto rollback;
1130                 }
1131
1132         /* Tenth step: apply changes */
1133         if ((r = transaction_apply(m, mode)) < 0) {
1134                 log_debug("Failed to apply transaction: %s", strerror(-r));
1135                 goto rollback;
1136         }
1137
1138         assert(hashmap_isempty(m->transaction_jobs));
1139         assert(!m->transaction_anchor);
1140
1141         return 0;
1142
1143 rollback:
1144         transaction_abort(m);
1145         return r;
1146 }
1147
1148 static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool override, bool *is_new) {
1149         Job *j, *f;
1150         int r;
1151
1152         assert(m);
1153         assert(unit);
1154
1155         /* Looks for an axisting prospective job and returns that. If
1156          * it doesn't exist it is created and added to the prospective
1157          * jobs list. */
1158
1159         f = hashmap_get(m->transaction_jobs, unit);
1160
1161         LIST_FOREACH(transaction, j, f) {
1162                 assert(j->unit == unit);
1163
1164                 if (j->type == type) {
1165                         if (is_new)
1166                                 *is_new = false;
1167                         return j;
1168                 }
1169         }
1170
1171         if (unit->meta.job && unit->meta.job->type == type)
1172                 j = unit->meta.job;
1173         else if (!(j = job_new(m, type, unit)))
1174                 return NULL;
1175
1176         j->generation = 0;
1177         j->marker = NULL;
1178         j->matters_to_anchor = false;
1179         j->override = override;
1180
1181         LIST_PREPEND(Job, transaction, f, j);
1182
1183         if ((r = hashmap_replace(m->transaction_jobs, unit, f)) < 0) {
1184                 job_free(j);
1185                 return NULL;
1186         }
1187
1188         if (is_new)
1189                 *is_new = true;
1190
1191         log_debug("Added job %s/%s to transaction.", unit->meta.id, job_type_to_string(type));
1192
1193         return j;
1194 }
1195
1196 void manager_transaction_unlink_job(Manager *m, Job *j, bool delete_dependencies) {
1197         assert(m);
1198         assert(j);
1199
1200         if (j->transaction_prev)
1201                 j->transaction_prev->transaction_next = j->transaction_next;
1202         else if (j->transaction_next)
1203                 hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
1204         else
1205                 hashmap_remove_value(m->transaction_jobs, j->unit, j);
1206
1207         if (j->transaction_next)
1208                 j->transaction_next->transaction_prev = j->transaction_prev;
1209
1210         j->transaction_prev = j->transaction_next = NULL;
1211
1212         while (j->subject_list)
1213                 job_dependency_free(j->subject_list);
1214
1215         while (j->object_list) {
1216                 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
1217
1218                 job_dependency_free(j->object_list);
1219
1220                 if (other && delete_dependencies) {
1221                         log_debug("Deleting job %s/%s as dependency of job %s/%s",
1222                                   other->unit->meta.id, job_type_to_string(other->type),
1223                                   j->unit->meta.id, job_type_to_string(j->type));
1224                         transaction_delete_job(m, other, delete_dependencies);
1225                 }
1226         }
1227 }
1228
1229 static int transaction_add_job_and_dependencies(
1230                 Manager *m,
1231                 JobType type,
1232                 Unit *unit,
1233                 Job *by,
1234                 bool matters,
1235                 bool override,
1236                 Job **_ret) {
1237         Job *ret;
1238         Iterator i;
1239         Unit *dep;
1240         int r;
1241         bool is_new;
1242
1243         assert(m);
1244         assert(type < _JOB_TYPE_MAX);
1245         assert(unit);
1246
1247         if (unit->meta.load_state != UNIT_LOADED)
1248                 return -EINVAL;
1249
1250         if (!unit_job_is_applicable(unit, type))
1251                 return -EBADR;
1252
1253         /* First add the job. */
1254         if (!(ret = transaction_add_one_job(m, type, unit, override, &is_new)))
1255                 return -ENOMEM;
1256
1257         /* Then, add a link to the job. */
1258         if (!job_dependency_new(by, ret, matters))
1259                 return -ENOMEM;
1260
1261         if (is_new) {
1262                 /* Finally, recursively add in all dependencies. */
1263                 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
1264                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
1265                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
1266                                         goto fail;
1267
1268                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
1269                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !override, override, NULL)) < 0 && r != -EBADR)
1270                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
1271
1272                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
1273                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, false, NULL)) < 0)
1274                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
1275
1276                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
1277                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
1278                                         goto fail;
1279
1280                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE_OVERRIDABLE], i)
1281                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !override, override, NULL)) < 0 && r != -EBADR)
1282                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
1283
1284                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
1285                                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
1286                                         goto fail;
1287
1288                 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
1289
1290                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
1291                                 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
1292                                         goto fail;
1293                 }
1294
1295                 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
1296         }
1297
1298         if (_ret)
1299                 *_ret = ret;
1300
1301         return 0;
1302
1303 fail:
1304         return r;
1305 }
1306
1307 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool override, Job **_ret) {
1308         int r;
1309         Job *ret;
1310
1311         assert(m);
1312         assert(type < _JOB_TYPE_MAX);
1313         assert(unit);
1314         assert(mode < _JOB_MODE_MAX);
1315
1316         log_debug("Trying to enqueue job %s/%s", unit->meta.id, job_type_to_string(type));
1317
1318         if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, override, &ret)) < 0) {
1319                 transaction_abort(m);
1320                 return r;
1321         }
1322
1323         if ((r = transaction_activate(m, mode)) < 0)
1324                 return r;
1325
1326         log_debug("Enqueued job %s/%s as %u", unit->meta.id, job_type_to_string(type), (unsigned) ret->id);
1327
1328         if (_ret)
1329                 *_ret = ret;
1330
1331         return 0;
1332 }
1333
1334 int manager_add_job_by_name(Manager *m, JobType type, const char *name, JobMode mode, bool override, Job **_ret) {
1335         Unit *unit;
1336         int r;
1337
1338         assert(m);
1339         assert(type < _JOB_TYPE_MAX);
1340         assert(name);
1341         assert(mode < _JOB_MODE_MAX);
1342
1343         if ((r = manager_load_unit(m, name, NULL, &unit)) < 0)
1344                 return r;
1345
1346         return manager_add_job(m, type, unit, mode, override, _ret);
1347 }
1348
1349 Job *manager_get_job(Manager *m, uint32_t id) {
1350         assert(m);
1351
1352         return hashmap_get(m->jobs, UINT32_TO_PTR(id));
1353 }
1354
1355 Unit *manager_get_unit(Manager *m, const char *name) {
1356         assert(m);
1357         assert(name);
1358
1359         return hashmap_get(m->units, name);
1360 }
1361
1362 unsigned manager_dispatch_load_queue(Manager *m) {
1363         Meta *meta;
1364         unsigned n = 0;
1365
1366         assert(m);
1367
1368         /* Make sure we are not run recursively */
1369         if (m->dispatching_load_queue)
1370                 return 0;
1371
1372         m->dispatching_load_queue = true;
1373
1374         /* Dispatches the load queue. Takes a unit from the queue and
1375          * tries to load its data until the queue is empty */
1376
1377         while ((meta = m->load_queue)) {
1378                 assert(meta->in_load_queue);
1379
1380                 unit_load(UNIT(meta));
1381                 n++;
1382         }
1383
1384         m->dispatching_load_queue = false;
1385         return n;
1386 }
1387
1388 int manager_load_unit(Manager *m, const char *name, const char *path, Unit **_ret) {
1389         Unit *ret;
1390         int r;
1391
1392         assert(m);
1393         assert(name || path);
1394
1395         /* This will load the service information files, but not actually
1396          * start any services or anything. */
1397
1398         if (path && !is_path(path))
1399                 return -EINVAL;
1400
1401         if (!name)
1402                 name = file_name_from_path(path);
1403
1404         if (!unit_name_is_valid(name))
1405                 return -EINVAL;
1406
1407         if ((ret = manager_get_unit(m, name))) {
1408                 *_ret = ret;
1409                 return 0;
1410         }
1411
1412         if (!(ret = unit_new(m)))
1413                 return -ENOMEM;
1414
1415         if (path)
1416                 if (!(ret->meta.fragment_path = strdup(path))) {
1417                         unit_free(ret);
1418                         return -ENOMEM;
1419                 }
1420
1421         if ((r = unit_add_name(ret, name)) < 0) {
1422                 unit_free(ret);
1423                 return r;
1424         }
1425
1426         unit_add_to_load_queue(ret);
1427         unit_add_to_dbus_queue(ret);
1428
1429         manager_dispatch_load_queue(m);
1430
1431         if (_ret)
1432                 *_ret = unit_follow_merge(ret);
1433
1434         return 0;
1435 }
1436
1437 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
1438         Iterator i;
1439         Job *j;
1440
1441         assert(s);
1442         assert(f);
1443
1444         HASHMAP_FOREACH(j, s->jobs, i)
1445                 job_dump(j, f, prefix);
1446 }
1447
1448 void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
1449         Iterator i;
1450         Unit *u;
1451         const char *t;
1452
1453         assert(s);
1454         assert(f);
1455
1456         HASHMAP_FOREACH_KEY(u, t, s->units, i)
1457                 if (u->meta.id == t)
1458                         unit_dump(u, f, prefix);
1459 }
1460
1461 void manager_clear_jobs(Manager *m) {
1462         Job *j;
1463
1464         assert(m);
1465
1466         transaction_abort(m);
1467
1468         while ((j = hashmap_first(m->jobs)))
1469                 job_free(j);
1470 }
1471
1472 unsigned manager_dispatch_run_queue(Manager *m) {
1473         Job *j;
1474         unsigned n = 0;
1475
1476         if (m->dispatching_run_queue)
1477                 return 0;
1478
1479         m->dispatching_run_queue = true;
1480
1481         while ((j = m->run_queue)) {
1482                 assert(j->installed);
1483                 assert(j->in_run_queue);
1484
1485                 job_run_and_invalidate(j);
1486                 n++;
1487         }
1488
1489         m->dispatching_run_queue = false;
1490         return n;
1491 }
1492
1493 unsigned manager_dispatch_dbus_queue(Manager *m) {
1494         Job *j;
1495         Meta *meta;
1496         unsigned n = 0;
1497
1498         assert(m);
1499
1500         if (m->dispatching_dbus_queue)
1501                 return 0;
1502
1503         m->dispatching_dbus_queue = true;
1504
1505         while ((meta = m->dbus_unit_queue)) {
1506                 assert(meta->in_dbus_queue);
1507
1508                 bus_unit_send_change_signal(UNIT(meta));
1509                 n++;
1510         }
1511
1512         while ((j = m->dbus_job_queue)) {
1513                 assert(j->in_dbus_queue);
1514
1515                 bus_job_send_change_signal(j);
1516                 n++;
1517         }
1518
1519         m->dispatching_dbus_queue = false;
1520         return n;
1521 }
1522
1523 static int manager_dispatch_sigchld(Manager *m) {
1524         assert(m);
1525
1526         for (;;) {
1527                 siginfo_t si;
1528                 Unit *u;
1529
1530                 zero(si);
1531
1532                 /* First we call waitd() for a PID and do not reap the
1533                  * zombie. That way we can still access /proc/$PID for
1534                  * it while it is a zombie. */
1535                 if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG|WNOWAIT) < 0) {
1536
1537                         if (errno == ECHILD)
1538                                 break;
1539
1540                         if (errno == EINTR)
1541                                 continue;
1542
1543                         return -errno;
1544                 }
1545
1546                 if (si.si_pid <= 0)
1547                         break;
1548
1549                 if (si.si_code == CLD_EXITED || si.si_code == CLD_KILLED || si.si_code == CLD_DUMPED) {
1550                         char *name = NULL;
1551
1552                         get_process_name(si.si_pid, &name);
1553                         log_debug("Got SIGCHLD for process %llu (%s)", (unsigned long long) si.si_pid, strna(name));
1554                         free(name);
1555                 }
1556
1557                 /* And now, we actually reap the zombie. */
1558                 if (waitid(P_PID, si.si_pid, &si, WEXITED) < 0) {
1559                         if (errno == EINTR)
1560                                 continue;
1561
1562                         return -errno;
1563                 }
1564
1565                 if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
1566                         continue;
1567
1568                 log_debug("Child %llu died (code=%s, status=%i/%s)",
1569                           (long long unsigned) si.si_pid,
1570                           sigchld_code_to_string(si.si_code),
1571                           si.si_status,
1572                           strna(si.si_code == CLD_EXITED ? exit_status_to_string(si.si_status) : strsignal(si.si_status)));
1573
1574                 if (!(u = hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid))))
1575                         continue;
1576
1577                 log_debug("Child %llu belongs to %s", (long long unsigned) si.si_pid, u->meta.id);
1578
1579                 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
1580         }
1581
1582         return 0;
1583 }
1584
1585 static void manager_start_target(Manager *m, const char *name) {
1586         int r;
1587
1588         if ((r = manager_add_job_by_name(m, JOB_START, name, JOB_REPLACE, true, NULL)) < 0)
1589                 log_error("Failed to enqueue %s job: %s", name, strerror(-r));
1590 }
1591
1592 static int manager_process_signal_fd(Manager *m) {
1593         ssize_t n;
1594         struct signalfd_siginfo sfsi;
1595         bool sigchld = false;
1596
1597         assert(m);
1598
1599         for (;;) {
1600                 if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
1601
1602                         if (n >= 0)
1603                                 return -EIO;
1604
1605                         if (errno == EAGAIN)
1606                                 break;
1607
1608                         return -errno;
1609                 }
1610
1611                 switch (sfsi.ssi_signo) {
1612
1613                 case SIGCHLD:
1614                         sigchld = true;
1615                         break;
1616
1617                 case SIGINT:
1618                 case SIGTERM:
1619
1620                         if (m->running_as == MANAGER_INIT) {
1621                                 manager_start_target(m, SPECIAL_CTRL_ALT_DEL_TARGET);
1622                                 break;
1623                         }
1624
1625                         m->exit_code = MANAGER_EXIT;
1626                         return 0;
1627
1628                 case SIGWINCH:
1629
1630                         if (m->running_as == MANAGER_INIT)
1631                                 manager_start_target(m, SPECIAL_KBREQUEST_TARGET);
1632
1633                         /* This is a nop on non-init */
1634                         break;
1635
1636                 case SIGPWR:
1637                         if (m->running_as == MANAGER_INIT)
1638                                 manager_start_target(m, SPECIAL_SIGPWR_TARGET);
1639
1640                         /* This is a nop on non-init */
1641                         break;
1642
1643                 case SIGUSR1:
1644                         manager_dump_units(m, stdout, "\t");
1645                         manager_dump_jobs(m, stdout, "\t");
1646                         break;
1647
1648                 case SIGUSR2:  {
1649                         Unit *u;
1650
1651                         u = manager_get_unit(m, SPECIAL_DBUS_SERVICE);
1652
1653                         if (!u || UNIT_IS_ACTIVE_OR_RELOADING(unit_active_state(u))) {
1654                                 log_info("Trying to reconnect to bus...");
1655                                 bus_init_system(m);
1656                                 bus_init_api(m);
1657                         }
1658
1659                         if (!u || !UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u))) {
1660                                 log_info("Loading D-Bus service...");
1661                                 manager_start_target(m, SPECIAL_DBUS_SERVICE);
1662                         }
1663
1664                         break;
1665                 }
1666
1667                 case SIGHUP:
1668                         m->exit_code = MANAGER_RELOAD;
1669                         break;
1670
1671                 default:
1672                         log_info("Got unhandled signal <%s>.", strsignal(sfsi.ssi_signo));
1673                 }
1674         }
1675
1676         if (sigchld)
1677                 return manager_dispatch_sigchld(m);
1678
1679         return 0;
1680 }
1681
1682 static int process_event(Manager *m, struct epoll_event *ev) {
1683         int r;
1684         Watch *w;
1685
1686         assert(m);
1687         assert(ev);
1688
1689         assert(w = ev->data.ptr);
1690
1691         switch (w->type) {
1692
1693         case WATCH_SIGNAL:
1694
1695                 /* An incoming signal? */
1696                 if (ev->events != EPOLLIN)
1697                         return -EINVAL;
1698
1699                 if ((r = manager_process_signal_fd(m)) < 0)
1700                         return r;
1701
1702                 break;
1703
1704         case WATCH_FD:
1705
1706                 /* Some fd event, to be dispatched to the units */
1707                 UNIT_VTABLE(w->data.unit)->fd_event(w->data.unit, w->fd, ev->events, w);
1708                 break;
1709
1710         case WATCH_TIMER: {
1711                 uint64_t v;
1712                 ssize_t k;
1713
1714                 /* Some timer event, to be dispatched to the units */
1715                 if ((k = read(w->fd, &v, sizeof(v))) != sizeof(v)) {
1716
1717                         if (k < 0 && (errno == EINTR || errno == EAGAIN))
1718                                 break;
1719
1720                         return k < 0 ? -errno : -EIO;
1721                 }
1722
1723                 UNIT_VTABLE(w->data.unit)->timer_event(w->data.unit, v, w);
1724                 break;
1725         }
1726
1727         case WATCH_MOUNT:
1728                 /* Some mount table change, intended for the mount subsystem */
1729                 mount_fd_event(m, ev->events);
1730                 break;
1731
1732         case WATCH_UDEV:
1733                 /* Some notification from udev, intended for the device subsystem */
1734                 device_fd_event(m, ev->events);
1735                 break;
1736
1737         case WATCH_DBUS_WATCH:
1738                 bus_watch_event(m, w, ev->events);
1739                 break;
1740
1741         case WATCH_DBUS_TIMEOUT:
1742                 bus_timeout_event(m, w, ev->events);
1743                 break;
1744
1745         default:
1746                 assert_not_reached("Unknown epoll event type.");
1747         }
1748
1749         return 0;
1750 }
1751
1752 int manager_loop(Manager *m) {
1753         int r;
1754
1755         RATELIMIT_DEFINE(rl, 1*USEC_PER_SEC, 1000);
1756
1757         assert(m);
1758         m->exit_code = MANAGER_RUNNING;
1759
1760         while (m->exit_code == MANAGER_RUNNING) {
1761                 struct epoll_event event;
1762                 int n;
1763
1764                 if (!ratelimit_test(&rl)) {
1765                         /* Yay, something is going seriously wrong, pause a little */
1766                         log_warning("Looping too fast. Throttling execution a little.");
1767                         sleep(1);
1768                 }
1769
1770                 if (manager_dispatch_cleanup_queue(m) > 0)
1771                         continue;
1772
1773                 if (manager_dispatch_load_queue(m) > 0)
1774                         continue;
1775
1776                 if (manager_dispatch_run_queue(m) > 0)
1777                         continue;
1778
1779                 if (bus_dispatch(m) > 0)
1780                         continue;
1781
1782                 if (manager_dispatch_dbus_queue(m) > 0)
1783                         continue;
1784
1785                 if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) {
1786
1787                         if (errno == -EINTR)
1788                                 continue;
1789
1790                         return -errno;
1791                 }
1792
1793                 assert(n == 1);
1794
1795                 if ((r = process_event(m, &event)) < 0)
1796                         return r;
1797         }
1798
1799         return m->exit_code;
1800 }
1801
1802 int manager_get_unit_from_dbus_path(Manager *m, const char *s, Unit **_u) {
1803         char *n;
1804         Unit *u;
1805
1806         assert(m);
1807         assert(s);
1808         assert(_u);
1809
1810         if (!startswith(s, "/org/freedesktop/systemd1/unit/"))
1811                 return -EINVAL;
1812
1813         if (!(n = bus_path_unescape(s+31)))
1814                 return -ENOMEM;
1815
1816         u = manager_get_unit(m, n);
1817         free(n);
1818
1819         if (!u)
1820                 return -ENOENT;
1821
1822         *_u = u;
1823
1824         return 0;
1825 }
1826
1827 int manager_get_job_from_dbus_path(Manager *m, const char *s, Job **_j) {
1828         Job *j;
1829         unsigned id;
1830         int r;
1831
1832         assert(m);
1833         assert(s);
1834         assert(_j);
1835
1836         if (!startswith(s, "/org/freedesktop/systemd1/job/"))
1837                 return -EINVAL;
1838
1839         if ((r = safe_atou(s + 30, &id)) < 0)
1840                 return r;
1841
1842         if (!(j = manager_get_job(m, id)))
1843                 return -ENOENT;
1844
1845         *_j = j;
1846
1847         return 0;
1848 }
1849
1850 static bool manager_utmp_good(Manager *m) {
1851         int r;
1852
1853         assert(m);
1854
1855         if ((r = mount_path_is_mounted(m, _PATH_UTMPX)) <= 0) {
1856
1857                 if (r < 0)
1858                         log_warning("Failed to determine whether " _PATH_UTMPX " is mounted: %s", strerror(-r));
1859
1860                 return false;
1861         }
1862
1863         return true;
1864 }
1865
1866 void manager_write_utmp_reboot(Manager *m) {
1867         int r;
1868
1869         assert(m);
1870
1871         if (m->utmp_reboot_written)
1872                 return;
1873
1874         if (m->running_as != MANAGER_INIT)
1875                 return;
1876
1877         if (!manager_utmp_good(m))
1878                 return;
1879
1880         if ((r = utmp_put_reboot(m->boot_timestamp)) < 0) {
1881
1882                 if (r != -ENOENT && r != -EROFS)
1883                         log_warning("Failed to write utmp/wtmp: %s", strerror(-r));
1884
1885                 return;
1886         }
1887
1888         m->utmp_reboot_written = true;
1889 }
1890
1891 void manager_write_utmp_runlevel(Manager *m, Unit *u) {
1892         int runlevel, r;
1893
1894         assert(m);
1895         assert(u);
1896
1897         if (u->meta.type != UNIT_TARGET)
1898                 return;
1899
1900         if (m->running_as != MANAGER_INIT)
1901                 return;
1902
1903         if (!manager_utmp_good(m))
1904                 return;
1905
1906         if ((runlevel = target_get_runlevel(TARGET(u))) <= 0)
1907                 return;
1908
1909         if ((r = utmp_put_runlevel(0, runlevel, 0)) < 0) {
1910
1911                 if (r != -ENOENT && r != -EROFS)
1912                         log_warning("Failed to write utmp/wtmp: %s", strerror(-r));
1913         }
1914 }
1915
1916 void manager_dispatch_bus_name_owner_changed(
1917                 Manager *m,
1918                 const char *name,
1919                 const char* old_owner,
1920                 const char *new_owner) {
1921
1922         Unit *u;
1923
1924         assert(m);
1925         assert(name);
1926
1927         if (!(u = hashmap_get(m->watch_bus, name)))
1928                 return;
1929
1930         UNIT_VTABLE(u)->bus_name_owner_change(u, name, old_owner, new_owner);
1931 }
1932
1933 void manager_dispatch_bus_query_pid_done(
1934                 Manager *m,
1935                 const char *name,
1936                 pid_t pid) {
1937
1938         Unit *u;
1939
1940         assert(m);
1941         assert(name);
1942         assert(pid >= 1);
1943
1944         if (!(u = hashmap_get(m->watch_bus, name)))
1945                 return;
1946
1947         UNIT_VTABLE(u)->bus_query_pid_done(u, name, pid);
1948 }
1949
1950 int manager_open_serialization(FILE **_f) {
1951         char *path;
1952         mode_t saved_umask;
1953         int fd;
1954         FILE *f;
1955
1956         assert(_f);
1957
1958         if (asprintf(&path, "/dev/shm/systemd-%u.dump-XXXXXX", (unsigned) getpid()) < 0)
1959                 return -ENOMEM;
1960
1961         saved_umask = umask(0077);
1962         fd = mkostemp(path, O_RDWR|O_CLOEXEC);
1963         umask(saved_umask);
1964
1965         if (fd < 0) {
1966                 free(path);
1967                 return -errno;
1968         }
1969
1970         unlink(path);
1971
1972         log_debug("Serializing state to %s", path);
1973         free(path);
1974
1975         if (!(f = fdopen(fd, "w+")) < 0)
1976                 return -errno;
1977
1978         *_f = f;
1979
1980         return 0;
1981 }
1982
1983 int manager_serialize(Manager *m, FILE *f, FDSet *fds) {
1984         Iterator i;
1985         Unit *u;
1986         const char *t;
1987         int r;
1988
1989         assert(m);
1990         assert(f);
1991         assert(fds);
1992
1993         HASHMAP_FOREACH_KEY(u, t, m->units, i) {
1994                 if (u->meta.id != t)
1995                         continue;
1996
1997                 if (!unit_can_serialize(u))
1998                         continue;
1999
2000                 /* Start marker */
2001                 fputs(u->meta.id, f);
2002                 fputc('\n', f);
2003
2004                 if ((r = unit_serialize(u, f, fds)) < 0)
2005                         return r;
2006         }
2007
2008         if (ferror(f))
2009                 return -EIO;
2010
2011         return 0;
2012 }
2013
2014 int manager_deserialize(Manager *m, FILE *f, FDSet *fds) {
2015         int r = 0;
2016
2017         assert(m);
2018         assert(f);
2019
2020         log_debug("Deserializing state...");
2021
2022         for (;;) {
2023                 Unit *u;
2024                 char name[UNIT_NAME_MAX+2];
2025
2026                 /* Start marker */
2027                 if (!fgets(name, sizeof(name), f)) {
2028                         if (feof(f))
2029                                 break;
2030
2031                         return -errno;
2032                 }
2033
2034                 char_array_0(name);
2035
2036                 if ((r = manager_load_unit(m, strstrip(name), NULL, &u)) < 0)
2037                         return r;
2038
2039                 if ((r = unit_deserialize(u, f, fds)) < 0)
2040                         return r;
2041         }
2042
2043         if (ferror(f))
2044                 return -EIO;
2045
2046         return 0;
2047 }
2048
2049 int manager_reload(Manager *m) {
2050         int r, q;
2051         FILE *f;
2052         FDSet *fds;
2053
2054         assert(m);
2055
2056         if ((r = manager_open_serialization(&f)) < 0)
2057                 return r;
2058
2059         if (!(fds = fdset_new())) {
2060                 r = -ENOMEM;
2061                 goto finish;
2062         }
2063
2064         if ((r = manager_serialize(m, f, fds)) < 0)
2065                 goto finish;
2066
2067         if (fseeko(f, 0, SEEK_SET) < 0) {
2068                 r = -errno;
2069                 goto finish;
2070         }
2071
2072         /* From here on there is no way back. */
2073         manager_clear_jobs_and_units(m);
2074
2075         /* First, enumerate what we can from all config files */
2076         if ((q = manager_enumerate(m)) < 0)
2077                 r = q;
2078
2079         /* Second, deserialize our stored data */
2080         if ((q = manager_deserialize(m, f, fds)) < 0)
2081                 r = q;
2082
2083         fclose(f);
2084         f = NULL;
2085
2086         /* Third, fire things up! */
2087         if ((q = manager_coldplug(m)) < 0)
2088                 r = q;
2089
2090 finish:
2091         if (f)
2092                 fclose(f);
2093
2094         if (fds)
2095                 fdset_free(fds);
2096
2097         return r;
2098 }
2099
2100 static const char* const manager_running_as_table[_MANAGER_RUNNING_AS_MAX] = {
2101         [MANAGER_INIT] = "init",
2102         [MANAGER_SYSTEM] = "system",
2103         [MANAGER_SESSION] = "session"
2104 };
2105
2106 DEFINE_STRING_TABLE_LOOKUP(manager_running_as, ManagerRunningAs);