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 /* As soon as 16 units are in our GC queue, make sure to run a gc sweep */
  56 #define GC_QUEUE_ENTRIES_MAX 16
  57
  58 /* As soon as 5s passed since a unit was added to our GC queue, make sure to run a gc sweep */
  59 #define GC_QUEUE_USEC_MAX (5*USEC_PER_SEC)
  60
  61 static int enable_special_signals(Manager *m) {
  62         char fd;
  63
  64         assert(m);
  65
  66         /* Enable that we get SIGINT on control-alt-del */
  67         if (reboot(RB_DISABLE_CAD) < 0)
  68                 log_warning("Failed to enable ctrl-alt-del handling: %m");
  69
  70         if ((fd = open_terminal("/dev/tty0", O_RDWR)) < 0)
  71                 log_warning("Failed to open /dev/tty0: %m");
  72         else {
  73                 /* Enable that we get SIGWINCH on kbrequest */
  74                 if (ioctl(fd, KDSIGACCEPT, SIGWINCH) < 0)
  75                         log_warning("Failed to enable kbrequest handling: %s", strerror(errno));
  76
  77                 close_nointr_nofail(fd);
  78         }
  79
  80         return 0;
  81 }
  82
  83 static int manager_setup_signals(Manager *m) {
  84         sigset_t mask;
  85         struct epoll_event ev;
  86         struct sigaction sa;
  87
  88         assert(m);
  89
  90         /* We are not interested in SIGSTOP and friends. */
  91         zero(sa);
  92         sa.sa_handler = SIG_DFL;
  93         sa.sa_flags = SA_NOCLDSTOP|SA_RESTART;
  94         assert_se(sigaction(SIGCHLD, &sa, NULL) == 0);
  95
  96         assert_se(sigemptyset(&mask) == 0);
  97         assert_se(sigaddset(&mask, SIGCHLD) == 0);
  98         assert_se(sigaddset(&mask, SIGTERM) == 0);
  99         assert_se(sigaddset(&mask, SIGHUP) == 0);
 100         assert_se(sigaddset(&mask, SIGUSR1) == 0);
 101         assert_se(sigaddset(&mask, SIGUSR2) == 0);
 102         assert_se(sigaddset(&mask, SIGINT) == 0);   /* Kernel sends us this on control-alt-del */
 103         assert_se(sigaddset(&mask, SIGWINCH) == 0); /* Kernel sends us this on kbrequest (alt-arrowup) */
 104         assert_se(sigaddset(&mask, SIGPWR) == 0);   /* Some kernel drivers and upsd send us this on power failure */
 105         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
 106
 107         m->signal_watch.type = WATCH_SIGNAL;
 108         if ((m->signal_watch.fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
 109                 return -errno;
 110
 111         zero(ev);
 112         ev.events = EPOLLIN;
 113         ev.data.ptr = &m->signal_watch;
 114
 115         if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_watch.fd, &ev) < 0)
 116                 return -errno;
 117
 118         if (m->running_as == MANAGER_INIT)
 119                 return enable_special_signals(m);
 120
 121         return 0;
 122 }
 123
 124 static char** session_dirs(void) {
 125         const char *home, *e;
 126         char *config_home = NULL, *data_home = NULL;
 127         char **config_dirs = NULL, **data_dirs = NULL;
 128         char **r = NULL, **t;
 129
 130         /* Implement the mechanisms defined in
 131          *
 132          * http://standards.freedesktop.org/basedir-spec/basedir-spec-0.6.html
 133          *
 134          * We look in both the config and the data dirs because we
 135          * want to encourage that distributors ship their unit files
 136          * as data, and allow overriding as configuration.
 137          */
 138
 139         home = getenv("HOME");
 140
 141         if ((e = getenv("XDG_CONFIG_HOME"))) {
 142                 if (asprintf(&config_home, "%s/systemd/session", e) < 0)
 143                         goto fail;
 144
 145         } else if (home) {
 146                 if (asprintf(&config_home, "%s/.config/systemd/session", home) < 0)
 147                         goto fail;
 148         }
 149
 150         if ((e = getenv("XDG_CONFIG_DIRS")))
 151                 config_dirs = strv_split(e, ":");
 152         else
 153                 config_dirs = strv_new("/etc/xdg", NULL);
 154
 155         if (!config_dirs)
 156                 goto fail;
 157
 158         if ((e = getenv("XDG_DATA_HOME"))) {
 159                 if (asprintf(&data_home, "%s/systemd/session", e) < 0)
 160                         goto fail;
 161
 162         } else if (home) {
 163                 if (asprintf(&data_home, "%s/.local/share/systemd/session", home) < 0)
 164                         goto fail;
 165         }
 166
 167         if ((e = getenv("XDG_DATA_DIRS")))
 168                 data_dirs = strv_split(e, ":");
 169         else
 170                 data_dirs = strv_new("/usr/local/share", "/usr/share", NULL);
 171
 172         if (!data_dirs)
 173                 goto fail;
 174
 175         /* Now merge everything we found. */
 176         if (config_home) {
 177                 if (!(t = strv_append(r, config_home)))
 178                         goto fail;
 179                 strv_free(r);
 180                 r = t;
 181         }
 182
 183         if (!(t = strv_merge_concat(r, config_dirs, "/systemd/session")))
 184                 goto finish;
 185         strv_free(r);
 186         r = t;
 187
 188         if (!(t = strv_append(r, SESSION_CONFIG_UNIT_PATH)))
 189                 goto fail;
 190         strv_free(r);
 191         r = t;
 192
 193         if (data_home) {
 194                 if (!(t = strv_append(r, data_home)))
 195                         goto fail;
 196                 strv_free(r);
 197                 r = t;
 198         }
 199
 200         if (!(t = strv_merge_concat(r, data_dirs, "/systemd/session")))
 201                 goto fail;
 202         strv_free(r);
 203         r = t;
 204
 205         if (!(t = strv_append(r, SESSION_DATA_UNIT_PATH)))
 206                 goto fail;
 207         strv_free(r);
 208         r = t;
 209
 210         if (!strv_path_make_absolute_cwd(r))
 211             goto fail;
 212
 213 finish:
 214         free(config_home);
 215         strv_free(config_dirs);
 216         free(data_home);
 217         strv_free(data_dirs);
 218
 219         return r;
 220
 221 fail:
 222         strv_free(r);
 223         r = NULL;
 224         goto finish;
 225 }
 226
 227 static int manager_find_paths(Manager *m) {
 228         const char *e;
 229         char *t;
 230
 231         assert(m);
 232
 233         /* First priority is whatever has been passed to us via env
 234          * vars */
 235         if ((e = getenv("SYSTEMD_UNIT_PATH")))
 236                 if (!(m->unit_path = split_path_and_make_absolute(e)))
 237                         return -ENOMEM;
 238
 239         if (strv_isempty(m->unit_path)) {
 240
 241                 /* Nothing is set, so let's figure something out. */
 242                 strv_free(m->unit_path);
 243
 244                 if (m->running_as == MANAGER_SESSION) {
 245                         if (!(m->unit_path = session_dirs()))
 246                                 return -ENOMEM;
 247                 } else
 248                         if (!(m->unit_path = strv_new(
 249                                               SYSTEM_CONFIG_UNIT_PATH,  /* /etc/systemd/system/ */
 250                                               SYSTEM_DATA_UNIT_PATH,    /* /lib/systemd/system/ */
 251                                               NULL)))
 252                                 return -ENOMEM;
 253         }
 254
 255         if (m->running_as == MANAGER_INIT) {
 256                 /* /etc/init.d/ compativility does not matter to users */
 257
 258                 if ((e = getenv("SYSTEMD_SYSVINIT_PATH")))
 259                         if (!(m->sysvinit_path = split_path_and_make_absolute(e)))
 260                                 return -ENOMEM;
 261
 262                 if (strv_isempty(m->sysvinit_path)) {
 263                         strv_free(m->sysvinit_path);
 264
 265                         if (!(m->sysvinit_path = strv_new(
 266                                               SYSTEM_SYSVINIT_PATH,     /* /etc/init.d/ */
 267                                               NULL)))
 268                                 return -ENOMEM;
 269                 }
 270
 271                 if ((e = getenv("SYSTEMD_SYSVRCND_PATH")))
 272                         if (!(m->sysvrcnd_path = split_path_and_make_absolute(e)))
 273                                 return -ENOMEM;
 274
 275                 if (strv_isempty(m->sysvrcnd_path)) {
 276                         strv_free(m->sysvrcnd_path);
 277
 278                         if (!(m->sysvrcnd_path = strv_new(
 279                                               SYSTEM_SYSVRCND_PATH,     /* /etc/rcN.d/ */
 280                                               NULL)))
 281                                 return -ENOMEM;
 282                 }
 283         }
 284
 285         strv_uniq(m->unit_path);
 286         strv_uniq(m->sysvinit_path);
 287         strv_uniq(m->sysvrcnd_path);
 288
 289         assert(!strv_isempty(m->unit_path));
 290         if (!(t = strv_join(m->unit_path, "\n\t")))
 291                 return -ENOMEM;
 292         log_debug("Looking for unit files in:\n\t%s", t);
 293         free(t);
 294
 295         if (!strv_isempty(m->sysvinit_path)) {
 296
 297                 if (!(t = strv_join(m->sysvinit_path, "\n\t")))
 298                         return -ENOMEM;
 299
 300                 log_debug("Looking for SysV init scripts in:\n\t%s", t);
 301                 free(t);
 302         } else
 303                 log_debug("Ignoring SysV init scripts.");
 304
 305         if (!strv_isempty(m->sysvrcnd_path)) {
 306
 307                 if (!(t = strv_join(m->sysvrcnd_path, "\n\t")))
 308                         return -ENOMEM;
 309
 310                 log_debug("Looking for SysV rcN.d links in:\n\t%s", t);
 311                 free(t);
 312         } else
 313                 log_debug("Ignoring SysV rcN.d links.");
 314
 315         return 0;
 316 }
 317
 318 int manager_new(ManagerRunningAs running_as, bool confirm_spawn, Manager **_m) {
 319         Manager *m;
 320         int r = -ENOMEM;
 321
 322         assert(_m);
 323         assert(running_as >= 0);
 324         assert(running_as < _MANAGER_RUNNING_AS_MAX);
 325
 326         if (!(m = new0(Manager, 1)))
 327                 return -ENOMEM;
 328
 329         m->boot_timestamp = now(CLOCK_REALTIME);
 330
 331         m->running_as = running_as;
 332         m->confirm_spawn = confirm_spawn;
 333         m->name_data_slot = -1;
 334         m->exit_code = _MANAGER_EXIT_CODE_INVALID;
 335
 336         m->signal_watch.fd = m->mount_watch.fd = m->udev_watch.fd = m->epoll_fd = m->dev_autofs_fd = -1;
 337         m->current_job_id = 1; /* start as id #1, so that we can leave #0 around as "null-like" value */
 338
 339         if (!(m->units = hashmap_new(string_hash_func, string_compare_func)))
 340                 goto fail;
 341
 342         if (!(m->jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
 343                 goto fail;
 344
 345         if (!(m->transaction_jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
 346                 goto fail;
 347
 348         if (!(m->watch_pids = hashmap_new(trivial_hash_func, trivial_compare_func)))
 349                 goto fail;
 350
 351         if (!(m->cgroup_bondings = hashmap_new(string_hash_func, string_compare_func)))
 352                 goto fail;
 353
 354         if (!(m->watch_bus = hashmap_new(string_hash_func, string_compare_func)))
 355                 goto fail;
 356
 357         if ((m->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0)
 358                 goto fail;
 359
 360         if ((r = manager_find_paths(m)) < 0)
 361                 goto fail;
 362
 363         if ((r = manager_setup_signals(m)) < 0)
 364                 goto fail;
 365
 366         if ((r = manager_setup_cgroup(m)) < 0)
 367                 goto fail;
 368
 369         /* Try to connect to the busses, if possible. */
 370         if ((r = bus_init_system(m)) < 0 ||
 371             (r = bus_init_api(m)) < 0)
 372                 goto fail;
 373
 374         *_m = m;
 375         return 0;
 376
 377 fail:
 378         manager_free(m);
 379         return r;
 380 }
 381
 382 static unsigned manager_dispatch_cleanup_queue(Manager *m) {
 383         Meta *meta;
 384         unsigned n = 0;
 385
 386         assert(m);
 387
 388         while ((meta = m->cleanup_queue)) {
 389                 assert(meta->in_cleanup_queue);
 390
 391                 unit_free(UNIT(meta));
 392                 n++;
 393         }
 394
 395         return n;
 396 }
 397
 398 static void unit_gc_sweep(Unit *u, int gc_marker) {
 399         Iterator i;
 400         Unit *other;
 401
 402         assert(u);
 403
 404         if (u->meta.gc_marker == gc_marker ||
 405             u->meta.gc_marker == -gc_marker)
 406                 return;
 407
 408         if (!u->meta.in_cleanup_queue)
 409                 goto bad;
 410
 411         if (unit_check_gc(u))
 412                 goto good;
 413
 414         SET_FOREACH(other, u->meta.dependencies[UNIT_REFERENCED_BY], i) {
 415                 unit_gc_sweep(other, gc_marker);
 416
 417                 if (other->meta.gc_marker == gc_marker)
 418                         goto good;
 419         }
 420
 421 bad:
 422         /* So there is no reason to keep this unit around, hence let's get rid of it */
 423         u->meta.gc_marker = -gc_marker;
 424         return;
 425
 426 good:
 427         u->meta.gc_marker = gc_marker;
 428 }
 429
 430 static unsigned manager_dispatch_gc_queue(Manager *m) {
 431         Meta *meta;
 432         unsigned n = 0;
 433         int gc_marker;
 434
 435         assert(m);
 436
 437         if ((m->n_in_gc_queue < GC_QUEUE_ENTRIES_MAX) &&
 438             (m->gc_queue_timestamp <= 0 ||
 439              (m->gc_queue_timestamp + GC_QUEUE_USEC_MAX) > now(CLOCK_MONOTONIC)))
 440                 return 0;
 441
 442         log_debug("Running GC...");
 443
 444         gc_marker = m->gc_marker;
 445         m->gc_marker = MIN(0, m->gc_marker + 1);
 446
 447         while ((meta = m->gc_queue)) {
 448                 assert(meta->in_gc_queue);
 449
 450                 LIST_REMOVE(Meta, gc_queue, m->gc_queue, meta);
 451                 meta->in_gc_queue = false;
 452
 453                 n++;
 454
 455                 unit_gc_sweep(UNIT(meta), gc_marker);
 456
 457                 if (meta->gc_marker == -gc_marker) {
 458                         log_debug("Collecting %s", meta->id);
 459                         unit_add_to_cleanup_queue(UNIT(meta));
 460                 }
 461         }
 462
 463         m->n_in_gc_queue = 0;
 464         m->gc_queue_timestamp = 0;
 465
 466         return n;
 467 }
 468
 469 static void manager_clear_jobs_and_units(Manager *m) {
 470         Job *j;
 471         Unit *u;
 472
 473         assert(m);
 474
 475         while ((j = hashmap_first(m->transaction_jobs)))
 476                 job_free(j);
 477
 478         while ((u = hashmap_first(m->units)))
 479                 unit_free(u);
 480 }
 481
 482 void manager_free(Manager *m) {
 483         UnitType c;
 484
 485         assert(m);
 486
 487         manager_clear_jobs_and_units(m);
 488
 489         for (c = 0; c < _UNIT_TYPE_MAX; c++)
 490                 if (unit_vtable[c]->shutdown)
 491                         unit_vtable[c]->shutdown(m);
 492
 493         /* If we reexecute ourselves, we keep the root cgroup
 494          * around */
 495         manager_shutdown_cgroup(m, m->exit_code != MANAGER_REEXECUTE);
 496
 497         bus_done_api(m);
 498         bus_done_system(m);
 499
 500         hashmap_free(m->units);
 501         hashmap_free(m->jobs);
 502         hashmap_free(m->transaction_jobs);
 503         hashmap_free(m->watch_pids);
 504         hashmap_free(m->watch_bus);
 505
 506         if (m->epoll_fd >= 0)
 507                 close_nointr_nofail(m->epoll_fd);
 508         if (m->signal_watch.fd >= 0)
 509                 close_nointr_nofail(m->signal_watch.fd);
 510
 511         strv_free(m->unit_path);
 512         strv_free(m->sysvinit_path);
 513         strv_free(m->sysvrcnd_path);
 514
 515         free(m->cgroup_controller);
 516         free(m->cgroup_hierarchy);
 517
 518         hashmap_free(m->cgroup_bondings);
 519
 520         free(m);
 521 }
 522
 523 int manager_enumerate(Manager *m) {
 524         int r = 0, q;
 525         UnitType c;
 526
 527         assert(m);
 528
 529         /* Let's ask every type to load all units from disk/kernel
 530          * that it might know */
 531         for (c = 0; c < _UNIT_TYPE_MAX; c++)
 532                 if (unit_vtable[c]->enumerate)
 533                         if ((q = unit_vtable[c]->enumerate(m)) < 0)
 534                                 r = q;
 535
 536         manager_dispatch_load_queue(m);
 537         return r;
 538 }
 539
 540 int manager_coldplug(Manager *m) {
 541         int r = 0, q;
 542         Iterator i;
 543         Unit *u;
 544         char *k;
 545
 546         assert(m);
 547
 548         /* Then, let's set up their initial state. */
 549         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
 550
 551                 /* ignore aliases */
 552                 if (u->meta.id != k)
 553                         continue;
 554
 555                 if (UNIT_VTABLE(u)->coldplug)
 556                         if ((q = UNIT_VTABLE(u)->coldplug(u)) < 0)
 557                                 r = q;
 558         }
 559
 560         return r;
 561 }
 562
 563 int manager_startup(Manager *m, FILE *serialization, FDSet *fds) {
 564         int r, q;
 565
 566         assert(m);
 567
 568         /* First, enumerate what we can from all config files */
 569         r = manager_enumerate(m);
 570
 571         /* Second, deserialize if there is something to deserialize */
 572         if (serialization)
 573                 if ((q = manager_deserialize(m, serialization, fds)) < 0)
 574                         r = q;
 575
 576         /* Third, fire things up! */
 577         if ((q = manager_coldplug(m)) < 0)
 578                 r = q;
 579
 580         /* Now that the initial devices are available, let's see if we
 581          * can write the utmp file */
 582         manager_write_utmp_reboot(m);
 583
 584         return r;
 585 }
 586
 587 static void transaction_delete_job(Manager *m, Job *j, bool delete_dependencies) {
 588         assert(m);
 589         assert(j);
 590
 591         /* Deletes one job from the transaction */
 592
 593         manager_transaction_unlink_job(m, j, delete_dependencies);
 594
 595         if (!j->installed)
 596                 job_free(j);
 597 }
 598
 599 static void transaction_delete_unit(Manager *m, Unit *u) {
 600         Job *j;
 601
 602         /* Deletes all jobs associated with a certain unit from the
 603          * transaction */
 604
 605         while ((j = hashmap_get(m->transaction_jobs, u)))
 606                 transaction_delete_job(m, j, true);
 607 }
 608
 609 static void transaction_clean_dependencies(Manager *m) {
 610         Iterator i;
 611         Job *j;
 612
 613         assert(m);
 614
 615         /* Drops all dependencies of all installed jobs */
 616
 617         HASHMAP_FOREACH(j, m->jobs, i) {
 618                 while (j->subject_list)
 619                         job_dependency_free(j->subject_list);
 620                 while (j->object_list)
 621                         job_dependency_free(j->object_list);
 622         }
 623
 624         assert(!m->transaction_anchor);
 625 }
 626
 627 static void transaction_abort(Manager *m) {
 628         Job *j;
 629
 630         assert(m);
 631
 632         while ((j = hashmap_first(m->transaction_jobs)))
 633                 if (j->installed)
 634                         transaction_delete_job(m, j, true);
 635                 else
 636                         job_free(j);
 637
 638         assert(hashmap_isempty(m->transaction_jobs));
 639
 640         transaction_clean_dependencies(m);
 641 }
 642
 643 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
 644         JobDependency *l;
 645
 646         assert(m);
 647
 648         /* A recursive sweep through the graph that marks all units
 649          * that matter to the anchor job, i.e. are directly or
 650          * indirectly a dependency of the anchor job via paths that
 651          * are fully marked as mattering. */
 652
 653         if (j)
 654                 l = j->subject_list;
 655         else
 656                 l = m->transaction_anchor;
 657
 658         LIST_FOREACH(subject, l, l) {
 659
 660                 /* This link does not matter */
 661                 if (!l->matters)
 662                         continue;
 663
 664                 /* This unit has already been marked */
 665                 if (l->object->generation == generation)
 666                         continue;
 667
 668                 l->object->matters_to_anchor = true;
 669                 l->object->generation = generation;
 670
 671                 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
 672         }
 673 }
 674
 675 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
 676         JobDependency *l, *last;
 677
 678         assert(j);
 679         assert(other);
 680         assert(j->unit == other->unit);
 681         assert(!j->installed);
 682
 683         /* Merges 'other' into 'j' and then deletes j. */
 684
 685         j->type = t;
 686         j->state = JOB_WAITING;
 687         j->override = j->override || other->override;
 688
 689         j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
 690
 691         /* Patch us in as new owner of the JobDependency objects */
 692         last = NULL;
 693         LIST_FOREACH(subject, l, other->subject_list) {
 694                 assert(l->subject == other);
 695                 l->subject = j;
 696                 last = l;
 697         }
 698
 699         /* Merge both lists */
 700         if (last) {
 701                 last->subject_next = j->subject_list;
 702                 if (j->subject_list)
 703                         j->subject_list->subject_prev = last;
 704                 j->subject_list = other->subject_list;
 705         }
 706
 707         /* Patch us in as new owner of the JobDependency objects */
 708         last = NULL;
 709         LIST_FOREACH(object, l, other->object_list) {
 710                 assert(l->object == other);
 711                 l->object = j;
 712                 last = l;
 713         }
 714
 715         /* Merge both lists */
 716         if (last) {
 717                 last->object_next = j->object_list;
 718                 if (j->object_list)
 719                         j->object_list->object_prev = last;
 720                 j->object_list = other->object_list;
 721         }
 722
 723         /* Kill the other job */
 724         other->subject_list = NULL;
 725         other->object_list = NULL;
 726         transaction_delete_job(m, other, true);
 727 }
 728
 729 static int delete_one_unmergeable_job(Manager *m, Job *j) {
 730         Job *k;
 731
 732         assert(j);
 733
 734         /* Tries to delete one item in the linked list
 735          * j->transaction_next->transaction_next->... that conflicts
 736          * whith another one, in an attempt to make an inconsistent
 737          * transaction work. */
 738
 739         /* We rely here on the fact that if a merged with b does not
 740          * merge with c, either a or b merge with c neither */
 741         LIST_FOREACH(transaction, j, j)
 742                 LIST_FOREACH(transaction, k, j->transaction_next) {
 743                         Job *d;
 744
 745                         /* Is this one mergeable? Then skip it */
 746                         if (job_type_is_mergeable(j->type, k->type))
 747                                 continue;
 748
 749                         /* Ok, we found two that conflict, let's see if we can
 750                          * drop one of them */
 751                         if (!j->matters_to_anchor)
 752                                 d = j;
 753                         else if (!k->matters_to_anchor)
 754                                 d = k;
 755                         else
 756                                 return -ENOEXEC;
 757
 758                         /* Ok, we can drop one, so let's do so. */
 759                         log_debug("Trying to fix job merging by deleting job %s/%s", d->unit->meta.id, job_type_to_string(d->type));
 760                         transaction_delete_job(m, d, true);
 761                         return 0;
 762                 }
 763
 764         return -EINVAL;
 765 }
 766
 767 static int transaction_merge_jobs(Manager *m) {
 768         Job *j;
 769         Iterator i;
 770         int r;
 771
 772         assert(m);
 773
 774         /* First step, check whether any of the jobs for one specific
 775          * task conflict. If so, try to drop one of them. */
 776         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 777                 JobType t;
 778                 Job *k;
 779
 780                 t = j->type;
 781                 LIST_FOREACH(transaction, k, j->transaction_next) {
 782                         if ((r = job_type_merge(&t, k->type)) >= 0)
 783                                 continue;
 784
 785                         /* OK, we could not merge all jobs for this
 786                          * action. Let's see if we can get rid of one
 787                          * of them */
 788
 789                         if ((r = delete_one_unmergeable_job(m, j)) >= 0)
 790                                 /* Ok, we managed to drop one, now
 791                                  * let's ask our callers to call us
 792                                  * again after garbage collecting */
 793                                 return -EAGAIN;
 794
 795                         /* We couldn't merge anything. Failure */
 796                         return r;
 797                 }
 798         }
 799
 800         /* Second step, merge the jobs. */
 801         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 802                 JobType t = j->type;
 803                 Job *k;
 804
 805                 /* Merge all transactions */
 806                 LIST_FOREACH(transaction, k, j->transaction_next)
 807                         assert_se(job_type_merge(&t, k->type) == 0);
 808
 809                 /* If an active job is mergeable, merge it too */
 810                 if (j->unit->meta.job)
 811                         job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
 812
 813                 while ((k = j->transaction_next)) {
 814                         if (j->installed) {
 815                                 transaction_merge_and_delete_job(m, k, j, t);
 816                                 j = k;
 817                         } else
 818                                 transaction_merge_and_delete_job(m, j, k, t);
 819                 }
 820
 821                 assert(!j->transaction_next);
 822                 assert(!j->transaction_prev);
 823         }
 824
 825         return 0;
 826 }
 827
 828 static void transaction_drop_redundant(Manager *m) {
 829         bool again;
 830
 831         assert(m);
 832
 833         /* Goes through the transaction and removes all jobs that are
 834          * a noop */
 835
 836         do {
 837                 Job *j;
 838                 Iterator i;
 839
 840                 again = false;
 841
 842                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 843                         bool changes_something = false;
 844                         Job *k;
 845
 846                         LIST_FOREACH(transaction, k, j) {
 847
 848                                 if (!job_is_anchor(k) &&
 849                                     job_type_is_redundant(k->type, unit_active_state(k->unit)))
 850                                         continue;
 851
 852                                 changes_something = true;
 853                                 break;
 854                         }
 855
 856                         if (changes_something)
 857                                 continue;
 858
 859                         log_debug("Found redundant job %s/%s, dropping.", j->unit->meta.id, job_type_to_string(j->type));
 860                         transaction_delete_job(m, j, false);
 861                         again = true;
 862                         break;
 863                 }
 864
 865         } while (again);
 866 }
 867
 868 static bool unit_matters_to_anchor(Unit *u, Job *j) {
 869         assert(u);
 870         assert(!j->transaction_prev);
 871
 872         /* Checks whether at least one of the jobs for this unit
 873          * matters to the anchor. */
 874
 875         LIST_FOREACH(transaction, j, j)
 876                 if (j->matters_to_anchor)
 877                         return true;
 878
 879         return false;
 880 }
 881
 882 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation) {
 883         Iterator i;
 884         Unit *u;
 885         int r;
 886
 887         assert(m);
 888         assert(j);
 889         assert(!j->transaction_prev);
 890
 891         /* Does a recursive sweep through the ordering graph, looking
 892          * for a cycle. If we find cycle we try to break it. */
 893
 894         /* Did we find a cycle? */
 895         if (j->marker && j->generation == generation) {
 896                 Job *k;
 897
 898                 /* So, we already have been here. We have a
 899                  * cycle. Let's try to break it. We go backwards in
 900                  * our path and try to find a suitable job to
 901                  * remove. We use the marker to find our way back,
 902                  * since smart how we are we stored our way back in
 903                  * there. */
 904
 905                 log_debug("Found ordering cycle on %s/%s", j->unit->meta.id, job_type_to_string(j->type));
 906
 907                 for (k = from; k; k = (k->generation == generation ? k->marker : NULL)) {
 908
 909                         log_debug("Walked on cycle path to %s/%s", k->unit->meta.id, job_type_to_string(k->type));
 910
 911                         if (!k->installed &&
 912                             !unit_matters_to_anchor(k->unit, k)) {
 913                                 /* Ok, we can drop this one, so let's
 914                                  * do so. */
 915                                 log_debug("Breaking order cycle by deleting job %s/%s", k->unit->meta.id, job_type_to_string(k->type));
 916                                 transaction_delete_unit(m, k->unit);
 917                                 return -EAGAIN;
 918                         }
 919
 920                         /* Check if this in fact was the beginning of
 921                          * the cycle */
 922                         if (k == j)
 923                                 break;
 924                 }
 925
 926                 log_debug("Unable to break cycle");
 927
 928                 return -ENOEXEC;
 929         }
 930
 931         /* Make the marker point to where we come from, so that we can
 932          * find our way backwards if we want to break a cycle */
 933         j->marker = from;
 934         j->generation = generation;
 935
 936         /* We assume that the the dependencies are bidirectional, and
 937          * hence can ignore UNIT_AFTER */
 938         SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
 939                 Job *o;
 940
 941                 /* Is there a job for this unit? */
 942                 if (!(o = hashmap_get(m->transaction_jobs, u)))
 943
 944                         /* Ok, there is no job for this in the
 945                          * transaction, but maybe there is already one
 946                          * running? */
 947                         if (!(o = u->meta.job))
 948                                 continue;
 949
 950                 if ((r = transaction_verify_order_one(m, o, j, generation)) < 0)
 951                         return r;
 952         }
 953
 954         /* Ok, let's backtrack, and remember that this entry is not on
 955          * our path anymore. */
 956         j->marker = NULL;
 957
 958         return 0;
 959 }
 960
 961 static int transaction_verify_order(Manager *m, unsigned *generation) {
 962         Job *j;
 963         int r;
 964         Iterator i;
 965
 966         assert(m);
 967         assert(generation);
 968
 969         /* Check if the ordering graph is cyclic. If it is, try to fix
 970          * that up by dropping one of the jobs. */
 971
 972         HASHMAP_FOREACH(j, m->transaction_jobs, i)
 973                 if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0)
 974                         return r;
 975
 976         return 0;
 977 }
 978
 979 static void transaction_collect_garbage(Manager *m) {
 980         bool again;
 981
 982         assert(m);
 983
 984         /* Drop jobs that are not required by any other job */
 985
 986         do {
 987                 Iterator i;
 988                 Job *j;
 989
 990                 again = false;
 991
 992                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 993                         if (j->object_list)
 994                                 continue;
 995
 996                         log_debug("Garbage collecting job %s/%s", j->unit->meta.id, job_type_to_string(j->type));
 997                         transaction_delete_job(m, j, true);
 998                         again = true;
 999                         break;
1000                 }
1001
1002         } while (again);
1003 }
1004
1005 static int transaction_is_destructive(Manager *m, JobMode mode) {
1006         Iterator i;
1007         Job *j;
1008
1009         assert(m);
1010
1011         /* Checks whether applying this transaction means that
1012          * existing jobs would be replaced */
1013
1014         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1015
1016                 /* Assume merged */
1017                 assert(!j->transaction_prev);
1018                 assert(!j->transaction_next);
1019
1020                 if (j->unit->meta.job &&
1021                     j->unit->meta.job != j &&
1022                     !job_type_is_superset(j->type, j->unit->meta.job->type))
1023                         return -EEXIST;
1024         }
1025
1026         return 0;
1027 }
1028
1029 static void transaction_minimize_impact(Manager *m) {
1030         bool again;
1031         assert(m);
1032
1033         /* Drops all unnecessary jobs that reverse already active jobs
1034          * or that stop a running service. */
1035
1036         do {
1037                 Job *j;
1038                 Iterator i;
1039
1040                 again = false;
1041
1042                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1043                         LIST_FOREACH(transaction, j, j) {
1044                                 bool stops_running_service, changes_existing_job;
1045
1046                                 /* If it matters, we shouldn't drop it */
1047                                 if (j->matters_to_anchor)
1048                                         continue;
1049
1050                                 /* Would this stop a running service?
1051                                  * Would this change an existing job?
1052                                  * If so, let's drop this entry */
1053
1054                                 stops_running_service =
1055                                         j->type == JOB_STOP && UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(j->unit));
1056
1057                                 changes_existing_job =
1058                                         j->unit->meta.job && job_type_is_conflicting(j->type, j->unit->meta.job->state);
1059
1060                                 if (!stops_running_service && !changes_existing_job)
1061                                         continue;
1062
1063                                 if (stops_running_service)
1064                                         log_debug("%s/%s would stop a running service.", j->unit->meta.id, job_type_to_string(j->type));
1065
1066                                 if (changes_existing_job)
1067                                         log_debug("%s/%s would change existing job.", j->unit->meta.id, job_type_to_string(j->type));
1068
1069                                 /* Ok, let's get rid of this */
1070                                 log_debug("Deleting %s/%s to minimize impact.", j->unit->meta.id, job_type_to_string(j->type));
1071
1072                                 transaction_delete_job(m, j, true);
1073                                 again = true;
1074                                 break;
1075                         }
1076
1077                         if (again)
1078                                 break;
1079                 }
1080
1081         } while (again);
1082 }
1083
1084 static int transaction_apply(Manager *m, JobMode mode) {
1085         Iterator i;
1086         Job *j;
1087         int r;
1088
1089         /* Moves the transaction jobs to the set of active jobs */
1090
1091         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1092                 /* Assume merged */
1093                 assert(!j->transaction_prev);
1094                 assert(!j->transaction_next);
1095
1096                 if (j->installed)
1097                         continue;
1098
1099                 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
1100                         goto rollback;
1101         }
1102
1103         while ((j = hashmap_steal_first(m->transaction_jobs))) {
1104                 if (j->installed)
1105                         continue;
1106
1107                 if (j->unit->meta.job)
1108                         job_free(j->unit->meta.job);
1109
1110                 j->unit->meta.job = j;
1111                 j->installed = true;
1112
1113                 /* We're fully installed. Now let's free data we don't
1114                  * need anymore. */
1115
1116                 assert(!j->transaction_next);
1117                 assert(!j->transaction_prev);
1118
1119                 job_add_to_run_queue(j);
1120                 job_add_to_dbus_queue(j);
1121         }
1122
1123         /* As last step, kill all remaining job dependencies. */
1124         transaction_clean_dependencies(m);
1125
1126         return 0;
1127
1128 rollback:
1129
1130         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1131                 if (j->installed)
1132                         continue;
1133
1134                 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
1135         }
1136
1137         return r;
1138 }
1139
1140 static int transaction_activate(Manager *m, JobMode mode) {
1141         int r;
1142         unsigned generation = 1;
1143
1144         assert(m);
1145
1146         /* This applies the changes recorded in transaction_jobs to
1147          * the actual list of jobs, if possible. */
1148
1149         /* First step: figure out which jobs matter */
1150         transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
1151
1152         /* Second step: Try not to stop any running services if
1153          * we don't have to. Don't try to reverse running
1154          * jobs if we don't have to. */
1155         transaction_minimize_impact(m);
1156
1157         /* Third step: Drop redundant jobs */
1158         transaction_drop_redundant(m);
1159
1160         for (;;) {
1161                 /* Fourth step: Let's remove unneeded jobs that might
1162                  * be lurking. */
1163                 transaction_collect_garbage(m);
1164
1165                 /* Fifth step: verify order makes sense and correct
1166                  * cycles if necessary and possible */
1167                 if ((r = transaction_verify_order(m, &generation)) >= 0)
1168                         break;
1169
1170                 if (r != -EAGAIN) {
1171                         log_debug("Requested transaction contains an unfixable cyclic ordering dependency: %s", strerror(-r));
1172                         goto rollback;
1173                 }
1174
1175                 /* Let's see if the resulting transaction ordering
1176                  * graph is still cyclic... */
1177         }
1178
1179         for (;;) {
1180                 /* Sixth step: let's drop unmergeable entries if
1181                  * necessary and possible, merge entries we can
1182                  * merge */
1183                 if ((r = transaction_merge_jobs(m)) >= 0)
1184                         break;
1185
1186                 if (r != -EAGAIN) {
1187                         log_debug("Requested transaction contains unmergable jobs: %s", strerror(-r));
1188                         goto rollback;
1189                 }
1190
1191                 /* Seventh step: an entry got dropped, let's garbage
1192                  * collect its dependencies. */
1193                 transaction_collect_garbage(m);
1194
1195                 /* Let's see if the resulting transaction still has
1196                  * unmergeable entries ... */
1197         }
1198
1199         /* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */
1200         transaction_drop_redundant(m);
1201
1202         /* Ninth step: check whether we can actually apply this */
1203         if (mode == JOB_FAIL)
1204                 if ((r = transaction_is_destructive(m, mode)) < 0) {
1205                         log_debug("Requested transaction contradicts existing jobs: %s", strerror(-r));
1206                         goto rollback;
1207                 }
1208
1209         /* Tenth step: apply changes */
1210         if ((r = transaction_apply(m, mode)) < 0) {
1211                 log_debug("Failed to apply transaction: %s", strerror(-r));
1212                 goto rollback;
1213         }
1214
1215         assert(hashmap_isempty(m->transaction_jobs));
1216         assert(!m->transaction_anchor);
1217
1218         return 0;
1219
1220 rollback:
1221         transaction_abort(m);
1222         return r;
1223 }
1224
1225 static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool override, bool *is_new) {
1226         Job *j, *f;
1227         int r;
1228
1229         assert(m);
1230         assert(unit);
1231
1232         /* Looks for an axisting prospective job and returns that. If
1233          * it doesn't exist it is created and added to the prospective
1234          * jobs list. */
1235
1236         f = hashmap_get(m->transaction_jobs, unit);
1237
1238         LIST_FOREACH(transaction, j, f) {
1239                 assert(j->unit == unit);
1240
1241                 if (j->type == type) {
1242                         if (is_new)
1243                                 *is_new = false;
1244                         return j;
1245                 }
1246         }
1247
1248         if (unit->meta.job && unit->meta.job->type == type)
1249                 j = unit->meta.job;
1250         else if (!(j = job_new(m, type, unit)))
1251                 return NULL;
1252
1253         j->generation = 0;
1254         j->marker = NULL;
1255         j->matters_to_anchor = false;
1256         j->override = override;
1257
1258         LIST_PREPEND(Job, transaction, f, j);
1259
1260         if ((r = hashmap_replace(m->transaction_jobs, unit, f)) < 0) {
1261                 job_free(j);
1262                 return NULL;
1263         }
1264
1265         if (is_new)
1266                 *is_new = true;
1267
1268         log_debug("Added job %s/%s to transaction.", unit->meta.id, job_type_to_string(type));
1269
1270         return j;
1271 }
1272
1273 void manager_transaction_unlink_job(Manager *m, Job *j, bool delete_dependencies) {
1274         assert(m);
1275         assert(j);
1276
1277         if (j->transaction_prev)
1278                 j->transaction_prev->transaction_next = j->transaction_next;
1279         else if (j->transaction_next)
1280                 hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
1281         else
1282                 hashmap_remove_value(m->transaction_jobs, j->unit, j);
1283
1284         if (j->transaction_next)
1285                 j->transaction_next->transaction_prev = j->transaction_prev;
1286
1287         j->transaction_prev = j->transaction_next = NULL;
1288
1289         while (j->subject_list)
1290                 job_dependency_free(j->subject_list);
1291
1292         while (j->object_list) {
1293                 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
1294
1295                 job_dependency_free(j->object_list);
1296
1297                 if (other && delete_dependencies) {
1298                         log_debug("Deleting job %s/%s as dependency of job %s/%s",
1299                                   other->unit->meta.id, job_type_to_string(other->type),
1300                                   j->unit->meta.id, job_type_to_string(j->type));
1301                         transaction_delete_job(m, other, delete_dependencies);
1302                 }
1303         }
1304 }
1305
1306 static int transaction_add_job_and_dependencies(
1307                 Manager *m,
1308                 JobType type,
1309                 Unit *unit,
1310                 Job *by,
1311                 bool matters,
1312                 bool override,
1313                 Job **_ret) {
1314         Job *ret;
1315         Iterator i;
1316         Unit *dep;
1317         int r;
1318         bool is_new;
1319
1320         assert(m);
1321         assert(type < _JOB_TYPE_MAX);
1322         assert(unit);
1323
1324         if (unit->meta.load_state != UNIT_LOADED)
1325                 return -EINVAL;
1326
1327         if (!unit_job_is_applicable(unit, type))
1328                 return -EBADR;
1329
1330         /* First add the job. */
1331         if (!(ret = transaction_add_one_job(m, type, unit, override, &is_new)))
1332                 return -ENOMEM;
1333
1334         /* Then, add a link to the job. */
1335         if (!job_dependency_new(by, ret, matters))
1336                 return -ENOMEM;
1337
1338         if (is_new) {
1339                 /* Finally, recursively add in all dependencies. */
1340                 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
1341                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
1342                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
1343                                         goto fail;
1344
1345                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
1346                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !override, override, NULL)) < 0 && r != -EBADR)
1347                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
1348
1349                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
1350                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, false, NULL)) < 0)
1351                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
1352
1353                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
1354                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
1355                                         goto fail;
1356
1357                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE_OVERRIDABLE], i)
1358                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !override, override, NULL)) < 0 && r != -EBADR)
1359                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
1360
1361                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
1362                                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
1363                                         goto fail;
1364
1365                 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
1366
1367                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
1368                                 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
1369                                         goto fail;
1370                 }
1371
1372                 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
1373         }
1374
1375         if (_ret)
1376                 *_ret = ret;
1377
1378         return 0;
1379
1380 fail:
1381         return r;
1382 }
1383
1384 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool override, Job **_ret) {
1385         int r;
1386         Job *ret;
1387
1388         assert(m);
1389         assert(type < _JOB_TYPE_MAX);
1390         assert(unit);
1391         assert(mode < _JOB_MODE_MAX);
1392
1393         log_debug("Trying to enqueue job %s/%s", unit->meta.id, job_type_to_string(type));
1394
1395         if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, override, &ret)) < 0) {
1396                 transaction_abort(m);
1397                 return r;
1398         }
1399
1400         if ((r = transaction_activate(m, mode)) < 0)
1401                 return r;
1402
1403         log_debug("Enqueued job %s/%s as %u", unit->meta.id, job_type_to_string(type), (unsigned) ret->id);
1404
1405         if (_ret)
1406                 *_ret = ret;
1407
1408         return 0;
1409 }
1410
1411 int manager_add_job_by_name(Manager *m, JobType type, const char *name, JobMode mode, bool override, Job **_ret) {
1412         Unit *unit;
1413         int r;
1414
1415         assert(m);
1416         assert(type < _JOB_TYPE_MAX);
1417         assert(name);
1418         assert(mode < _JOB_MODE_MAX);
1419
1420         if ((r = manager_load_unit(m, name, NULL, &unit)) < 0)
1421                 return r;
1422
1423         return manager_add_job(m, type, unit, mode, override, _ret);
1424 }
1425
1426 Job *manager_get_job(Manager *m, uint32_t id) {
1427         assert(m);
1428
1429         return hashmap_get(m->jobs, UINT32_TO_PTR(id));
1430 }
1431
1432 Unit *manager_get_unit(Manager *m, const char *name) {
1433         assert(m);
1434         assert(name);
1435
1436         return hashmap_get(m->units, name);
1437 }
1438
1439 unsigned manager_dispatch_load_queue(Manager *m) {
1440         Meta *meta;
1441         unsigned n = 0;
1442
1443         assert(m);
1444
1445         /* Make sure we are not run recursively */
1446         if (m->dispatching_load_queue)
1447                 return 0;
1448
1449         m->dispatching_load_queue = true;
1450
1451         /* Dispatches the load queue. Takes a unit from the queue and
1452          * tries to load its data until the queue is empty */
1453
1454         while ((meta = m->load_queue)) {
1455                 assert(meta->in_load_queue);
1456
1457                 unit_load(UNIT(meta));
1458                 n++;
1459         }
1460
1461         m->dispatching_load_queue = false;
1462         return n;
1463 }
1464
1465 int manager_load_unit(Manager *m, const char *name, const char *path, Unit **_ret) {
1466         Unit *ret;
1467         int r;
1468
1469         assert(m);
1470         assert(name || path);
1471
1472         /* This will load the service information files, but not actually
1473          * start any services or anything. */
1474
1475         if (path && !is_path(path))
1476                 return -EINVAL;
1477
1478         if (!name)
1479                 name = file_name_from_path(path);
1480
1481         if (!unit_name_is_valid(name))
1482                 return -EINVAL;
1483
1484         if ((ret = manager_get_unit(m, name))) {
1485                 *_ret = ret;
1486                 return 0;
1487         }
1488
1489         if (!(ret = unit_new(m)))
1490                 return -ENOMEM;
1491
1492         if (path)
1493                 if (!(ret->meta.fragment_path = strdup(path))) {
1494                         unit_free(ret);
1495                         return -ENOMEM;
1496                 }
1497
1498         if ((r = unit_add_name(ret, name)) < 0) {
1499                 unit_free(ret);
1500                 return r;
1501         }
1502
1503         unit_add_to_load_queue(ret);
1504         unit_add_to_dbus_queue(ret);
1505
1506         manager_dispatch_load_queue(m);
1507
1508         if (_ret)
1509                 *_ret = unit_follow_merge(ret);
1510
1511         return 0;
1512 }
1513
1514 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
1515         Iterator i;
1516         Job *j;
1517
1518         assert(s);
1519         assert(f);
1520
1521         HASHMAP_FOREACH(j, s->jobs, i)
1522                 job_dump(j, f, prefix);
1523 }
1524
1525 void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
1526         Iterator i;
1527         Unit *u;
1528         const char *t;
1529
1530         assert(s);
1531         assert(f);
1532
1533         HASHMAP_FOREACH_KEY(u, t, s->units, i)
1534                 if (u->meta.id == t)
1535                         unit_dump(u, f, prefix);
1536 }
1537
1538 void manager_clear_jobs(Manager *m) {
1539         Job *j;
1540
1541         assert(m);
1542
1543         transaction_abort(m);
1544
1545         while ((j = hashmap_first(m->jobs)))
1546                 job_free(j);
1547 }
1548
1549 unsigned manager_dispatch_run_queue(Manager *m) {
1550         Job *j;
1551         unsigned n = 0;
1552
1553         if (m->dispatching_run_queue)
1554                 return 0;
1555
1556         m->dispatching_run_queue = true;
1557
1558         while ((j = m->run_queue)) {
1559                 assert(j->installed);
1560                 assert(j->in_run_queue);
1561
1562                 job_run_and_invalidate(j);
1563                 n++;
1564         }
1565
1566         m->dispatching_run_queue = false;
1567         return n;
1568 }
1569
1570 unsigned manager_dispatch_dbus_queue(Manager *m) {
1571         Job *j;
1572         Meta *meta;
1573         unsigned n = 0;
1574
1575         assert(m);
1576
1577         if (m->dispatching_dbus_queue)
1578                 return 0;
1579
1580         m->dispatching_dbus_queue = true;
1581
1582         while ((meta = m->dbus_unit_queue)) {
1583                 assert(meta->in_dbus_queue);
1584
1585                 bus_unit_send_change_signal(UNIT(meta));
1586                 n++;
1587         }
1588
1589         while ((j = m->dbus_job_queue)) {
1590                 assert(j->in_dbus_queue);
1591
1592                 bus_job_send_change_signal(j);
1593                 n++;
1594         }
1595
1596         m->dispatching_dbus_queue = false;
1597         return n;
1598 }
1599
1600 static int manager_dispatch_sigchld(Manager *m) {
1601         assert(m);
1602
1603         for (;;) {
1604                 siginfo_t si;
1605                 Unit *u;
1606
1607                 zero(si);
1608
1609                 /* First we call waitd() for a PID and do not reap the
1610                  * zombie. That way we can still access /proc/$PID for
1611                  * it while it is a zombie. */
1612                 if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG|WNOWAIT) < 0) {
1613
1614                         if (errno == ECHILD)
1615                                 break;
1616
1617                         if (errno == EINTR)
1618                                 continue;
1619
1620                         return -errno;
1621                 }
1622
1623                 if (si.si_pid <= 0)
1624                         break;
1625
1626                 if (si.si_code == CLD_EXITED || si.si_code == CLD_KILLED || si.si_code == CLD_DUMPED) {
1627                         char *name = NULL;
1628
1629                         get_process_name(si.si_pid, &name);
1630                         log_debug("Got SIGCHLD for process %llu (%s)", (unsigned long long) si.si_pid, strna(name));
1631                         free(name);
1632                 }
1633
1634                 /* And now, we actually reap the zombie. */
1635                 if (waitid(P_PID, si.si_pid, &si, WEXITED) < 0) {
1636                         if (errno == EINTR)
1637                                 continue;
1638
1639                         return -errno;
1640                 }
1641
1642                 if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
1643                         continue;
1644
1645                 log_debug("Child %llu died (code=%s, status=%i/%s)",
1646                           (long long unsigned) si.si_pid,
1647                           sigchld_code_to_string(si.si_code),
1648                           si.si_status,
1649                           strna(si.si_code == CLD_EXITED ? exit_status_to_string(si.si_status) : strsignal(si.si_status)));
1650
1651                 if (!(u = hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid))))
1652                         continue;
1653
1654                 log_debug("Child %llu belongs to %s", (long long unsigned) si.si_pid, u->meta.id);
1655
1656                 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
1657         }
1658
1659         return 0;
1660 }
1661
1662 static void manager_start_target(Manager *m, const char *name) {
1663         int r;
1664
1665         if ((r = manager_add_job_by_name(m, JOB_START, name, JOB_REPLACE, true, NULL)) < 0)
1666                 log_error("Failed to enqueue %s job: %s", name, strerror(-r));
1667 }
1668
1669 static int manager_process_signal_fd(Manager *m) {
1670         ssize_t n;
1671         struct signalfd_siginfo sfsi;
1672         bool sigchld = false;
1673
1674         assert(m);
1675
1676         for (;;) {
1677                 if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
1678
1679                         if (n >= 0)
1680                                 return -EIO;
1681
1682                         if (errno == EAGAIN)
1683                                 break;
1684
1685                         return -errno;
1686                 }
1687
1688                 switch (sfsi.ssi_signo) {
1689
1690                 case SIGCHLD:
1691                         sigchld = true;
1692                         break;
1693
1694                 case SIGINT:
1695                 case SIGTERM:
1696
1697                         if (m->running_as == MANAGER_INIT) {
1698                                 manager_start_target(m, SPECIAL_CTRL_ALT_DEL_TARGET);
1699                                 break;
1700                         }
1701
1702                         m->exit_code = MANAGER_EXIT;
1703                         return 0;
1704
1705                 case SIGWINCH:
1706
1707                         if (m->running_as == MANAGER_INIT)
1708                                 manager_start_target(m, SPECIAL_KBREQUEST_TARGET);
1709
1710                         /* This is a nop on non-init */
1711                         break;
1712
1713                 case SIGPWR:
1714                         if (m->running_as == MANAGER_INIT)
1715                                 manager_start_target(m, SPECIAL_SIGPWR_TARGET);
1716
1717                         /* This is a nop on non-init */
1718                         break;
1719
1720                 case SIGUSR1:
1721                         manager_dump_units(m, stdout, "\t");
1722                         manager_dump_jobs(m, stdout, "\t");
1723                         break;
1724
1725                 case SIGUSR2:  {
1726                         Unit *u;
1727
1728                         u = manager_get_unit(m, SPECIAL_DBUS_SERVICE);
1729
1730                         if (!u || UNIT_IS_ACTIVE_OR_RELOADING(unit_active_state(u))) {
1731                                 log_info("Trying to reconnect to bus...");
1732                                 bus_init_system(m);
1733                                 bus_init_api(m);
1734                         }
1735
1736                         if (!u || !UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u))) {
1737                                 log_info("Loading D-Bus service...");
1738                                 manager_start_target(m, SPECIAL_DBUS_SERVICE);
1739                         }
1740
1741                         break;
1742                 }
1743
1744                 case SIGHUP:
1745                         m->exit_code = MANAGER_RELOAD;
1746                         break;
1747
1748                 default:
1749                         log_info("Got unhandled signal <%s>.", strsignal(sfsi.ssi_signo));
1750                 }
1751         }
1752
1753         if (sigchld)
1754                 return manager_dispatch_sigchld(m);
1755
1756         return 0;
1757 }
1758
1759 static int process_event(Manager *m, struct epoll_event *ev) {
1760         int r;
1761         Watch *w;
1762
1763         assert(m);
1764         assert(ev);
1765
1766         assert(w = ev->data.ptr);
1767
1768         switch (w->type) {
1769
1770         case WATCH_SIGNAL:
1771
1772                 /* An incoming signal? */
1773                 if (ev->events != EPOLLIN)
1774                         return -EINVAL;
1775
1776                 if ((r = manager_process_signal_fd(m)) < 0)
1777                         return r;
1778
1779                 break;
1780
1781         case WATCH_FD:
1782
1783                 /* Some fd event, to be dispatched to the units */
1784                 UNIT_VTABLE(w->data.unit)->fd_event(w->data.unit, w->fd, ev->events, w);
1785                 break;
1786
1787         case WATCH_TIMER: {
1788                 uint64_t v;
1789                 ssize_t k;
1790
1791                 /* Some timer event, to be dispatched to the units */
1792                 if ((k = read(w->fd, &v, sizeof(v))) != sizeof(v)) {
1793
1794                         if (k < 0 && (errno == EINTR || errno == EAGAIN))
1795                                 break;
1796
1797                         return k < 0 ? -errno : -EIO;
1798                 }
1799
1800                 UNIT_VTABLE(w->data.unit)->timer_event(w->data.unit, v, w);
1801                 break;
1802         }
1803
1804         case WATCH_MOUNT:
1805                 /* Some mount table change, intended for the mount subsystem */
1806                 mount_fd_event(m, ev->events);
1807                 break;
1808
1809         case WATCH_UDEV:
1810                 /* Some notification from udev, intended for the device subsystem */
1811                 device_fd_event(m, ev->events);
1812                 break;
1813
1814         case WATCH_DBUS_WATCH:
1815                 bus_watch_event(m, w, ev->events);
1816                 break;
1817
1818         case WATCH_DBUS_TIMEOUT:
1819                 bus_timeout_event(m, w, ev->events);
1820                 break;
1821
1822         default:
1823                 assert_not_reached("Unknown epoll event type.");
1824         }
1825
1826         return 0;
1827 }
1828
1829 int manager_loop(Manager *m) {
1830         int r;
1831
1832         RATELIMIT_DEFINE(rl, 1*USEC_PER_SEC, 1000);
1833
1834         assert(m);
1835         m->exit_code = MANAGER_RUNNING;
1836
1837         while (m->exit_code == MANAGER_RUNNING) {
1838                 struct epoll_event event;
1839                 int n;
1840
1841                 if (!ratelimit_test(&rl)) {
1842                         /* Yay, something is going seriously wrong, pause a little */
1843                         log_warning("Looping too fast. Throttling execution a little.");
1844                         sleep(1);
1845                 }
1846
1847                 if (manager_dispatch_cleanup_queue(m) > 0)
1848                         continue;
1849
1850                 if (manager_dispatch_gc_queue(m) > 0)
1851                         continue;
1852
1853                 if (manager_dispatch_load_queue(m) > 0)
1854                         continue;
1855
1856                 if (manager_dispatch_run_queue(m) > 0)
1857                         continue;
1858
1859                 if (bus_dispatch(m) > 0)
1860                         continue;
1861
1862                 if (manager_dispatch_dbus_queue(m) > 0)
1863                         continue;
1864
1865                 if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) {
1866
1867                         if (errno == -EINTR)
1868                                 continue;
1869
1870                         return -errno;
1871                 }
1872
1873                 assert(n == 1);
1874
1875                 if ((r = process_event(m, &event)) < 0)
1876                         return r;
1877         }
1878
1879         return m->exit_code;
1880 }
1881
1882 int manager_get_unit_from_dbus_path(Manager *m, const char *s, Unit **_u) {
1883         char *n;
1884         Unit *u;
1885
1886         assert(m);
1887         assert(s);
1888         assert(_u);
1889
1890         if (!startswith(s, "/org/freedesktop/systemd1/unit/"))
1891                 return -EINVAL;
1892
1893         if (!(n = bus_path_unescape(s+31)))
1894                 return -ENOMEM;
1895
1896         u = manager_get_unit(m, n);
1897         free(n);
1898
1899         if (!u)
1900                 return -ENOENT;
1901
1902         *_u = u;
1903
1904         return 0;
1905 }
1906
1907 int manager_get_job_from_dbus_path(Manager *m, const char *s, Job **_j) {
1908         Job *j;
1909         unsigned id;
1910         int r;
1911
1912         assert(m);
1913         assert(s);
1914         assert(_j);
1915
1916         if (!startswith(s, "/org/freedesktop/systemd1/job/"))
1917                 return -EINVAL;
1918
1919         if ((r = safe_atou(s + 30, &id)) < 0)
1920                 return r;
1921
1922         if (!(j = manager_get_job(m, id)))
1923                 return -ENOENT;
1924
1925         *_j = j;
1926
1927         return 0;
1928 }
1929
1930 static bool manager_utmp_good(Manager *m) {
1931         int r;
1932
1933         assert(m);
1934
1935         if ((r = mount_path_is_mounted(m, _PATH_UTMPX)) <= 0) {
1936
1937                 if (r < 0)
1938                         log_warning("Failed to determine whether " _PATH_UTMPX " is mounted: %s", strerror(-r));
1939
1940                 return false;
1941         }
1942
1943         return true;
1944 }
1945
1946 void manager_write_utmp_reboot(Manager *m) {
1947         int r;
1948
1949         assert(m);
1950
1951         if (m->utmp_reboot_written)
1952                 return;
1953
1954         if (m->running_as != MANAGER_INIT)
1955                 return;
1956
1957         if (!manager_utmp_good(m))
1958                 return;
1959
1960         if ((r = utmp_put_reboot(m->boot_timestamp)) < 0) {
1961
1962                 if (r != -ENOENT && r != -EROFS)
1963                         log_warning("Failed to write utmp/wtmp: %s", strerror(-r));
1964
1965                 return;
1966         }
1967
1968         m->utmp_reboot_written = true;
1969 }
1970
1971 void manager_write_utmp_runlevel(Manager *m, Unit *u) {
1972         int runlevel, r;
1973
1974         assert(m);
1975         assert(u);
1976
1977         if (u->meta.type != UNIT_TARGET)
1978                 return;
1979
1980         if (m->running_as != MANAGER_INIT)
1981                 return;
1982
1983         if (!manager_utmp_good(m))
1984                 return;
1985
1986         if ((runlevel = target_get_runlevel(TARGET(u))) <= 0)
1987                 return;
1988
1989         if ((r = utmp_put_runlevel(0, runlevel, 0)) < 0) {
1990
1991                 if (r != -ENOENT && r != -EROFS)
1992                         log_warning("Failed to write utmp/wtmp: %s", strerror(-r));
1993         }
1994 }
1995
1996 void manager_dispatch_bus_name_owner_changed(
1997                 Manager *m,
1998                 const char *name,
1999                 const char* old_owner,
2000                 const char *new_owner) {
2001
2002         Unit *u;
2003
2004         assert(m);
2005         assert(name);
2006
2007         if (!(u = hashmap_get(m->watch_bus, name)))
2008                 return;
2009
2010         UNIT_VTABLE(u)->bus_name_owner_change(u, name, old_owner, new_owner);
2011 }
2012
2013 void manager_dispatch_bus_query_pid_done(
2014                 Manager *m,
2015                 const char *name,
2016                 pid_t pid) {
2017
2018         Unit *u;
2019
2020         assert(m);
2021         assert(name);
2022         assert(pid >= 1);
2023
2024         if (!(u = hashmap_get(m->watch_bus, name)))
2025                 return;
2026
2027         UNIT_VTABLE(u)->bus_query_pid_done(u, name, pid);
2028 }
2029
2030 int manager_open_serialization(FILE **_f) {
2031         char *path;
2032         mode_t saved_umask;
2033         int fd;
2034         FILE *f;
2035
2036         assert(_f);
2037
2038         if (asprintf(&path, "/dev/shm/systemd-%u.dump-XXXXXX", (unsigned) getpid()) < 0)
2039                 return -ENOMEM;
2040
2041         saved_umask = umask(0077);
2042         fd = mkostemp(path, O_RDWR|O_CLOEXEC);
2043         umask(saved_umask);
2044
2045         if (fd < 0) {
2046                 free(path);
2047                 return -errno;
2048         }
2049
2050         unlink(path);
2051
2052         log_debug("Serializing state to %s", path);
2053         free(path);
2054
2055         if (!(f = fdopen(fd, "w+")) < 0)
2056                 return -errno;
2057
2058         *_f = f;
2059
2060         return 0;
2061 }
2062
2063 int manager_serialize(Manager *m, FILE *f, FDSet *fds) {
2064         Iterator i;
2065         Unit *u;
2066         const char *t;
2067         int r;
2068
2069         assert(m);
2070         assert(f);
2071         assert(fds);
2072
2073         HASHMAP_FOREACH_KEY(u, t, m->units, i) {
2074                 if (u->meta.id != t)
2075                         continue;
2076
2077                 if (!unit_can_serialize(u))
2078                         continue;
2079
2080                 /* Start marker */
2081                 fputs(u->meta.id, f);
2082                 fputc('\n', f);
2083
2084                 if ((r = unit_serialize(u, f, fds)) < 0)
2085                         return r;
2086         }
2087
2088         if (ferror(f))
2089                 return -EIO;
2090
2091         return 0;
2092 }
2093
2094 int manager_deserialize(Manager *m, FILE *f, FDSet *fds) {
2095         int r = 0;
2096
2097         assert(m);
2098         assert(f);
2099
2100         log_debug("Deserializing state...");
2101
2102         for (;;) {
2103                 Unit *u;
2104                 char name[UNIT_NAME_MAX+2];
2105
2106                 /* Start marker */
2107                 if (!fgets(name, sizeof(name), f)) {
2108                         if (feof(f))
2109                                 break;
2110
2111                         return -errno;
2112                 }
2113
2114                 char_array_0(name);
2115
2116                 if ((r = manager_load_unit(m, strstrip(name), NULL, &u)) < 0)
2117                         return r;
2118
2119                 if ((r = unit_deserialize(u, f, fds)) < 0)
2120                         return r;
2121         }
2122
2123         if (ferror(f))
2124                 return -EIO;
2125
2126         return 0;
2127 }
2128
2129 int manager_reload(Manager *m) {
2130         int r, q;
2131         FILE *f;
2132         FDSet *fds;
2133
2134         assert(m);
2135
2136         if ((r = manager_open_serialization(&f)) < 0)
2137                 return r;
2138
2139         if (!(fds = fdset_new())) {
2140                 r = -ENOMEM;
2141                 goto finish;
2142         }
2143
2144         if ((r = manager_serialize(m, f, fds)) < 0)
2145                 goto finish;
2146
2147         if (fseeko(f, 0, SEEK_SET) < 0) {
2148                 r = -errno;
2149                 goto finish;
2150         }
2151
2152         /* From here on there is no way back. */
2153         manager_clear_jobs_and_units(m);
2154
2155         /* First, enumerate what we can from all config files */
2156         if ((q = manager_enumerate(m)) < 0)
2157                 r = q;
2158
2159         /* Second, deserialize our stored data */
2160         if ((q = manager_deserialize(m, f, fds)) < 0)
2161                 r = q;
2162
2163         fclose(f);
2164         f = NULL;
2165
2166         /* Third, fire things up! */
2167         if ((q = manager_coldplug(m)) < 0)
2168                 r = q;
2169
2170 finish:
2171         if (f)
2172                 fclose(f);
2173
2174         if (fds)
2175                 fdset_free(fds);
2176
2177         return r;
2178 }
2179
2180 static const char* const manager_running_as_table[_MANAGER_RUNNING_AS_MAX] = {
2181         [MANAGER_INIT] = "init",
2182         [MANAGER_SYSTEM] = "system",
2183         [MANAGER_SESSION] = "session"
2184 };
2185
2186 DEFINE_STRING_TABLE_LOOKUP(manager_running_as, ManagerRunningAs);