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