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 enum {
 399         GC_OFFSET_IN_PATH,  /* This one is on the path we were travelling */
 400         GC_OFFSET_UNSURE,   /* No clue */
 401         GC_OFFSET_GOOD,     /* We still need this unit */
 402         GC_OFFSET_BAD,      /* We don't need this unit anymore */
 403         _GC_OFFSET_MAX
 404 };
 405
 406 static void unit_gc_sweep(Unit *u, unsigned gc_marker) {
 407         Iterator i;
 408         Unit *other;
 409         bool is_bad;
 410
 411         assert(u);
 412
 413         if (u->meta.gc_marker == gc_marker + GC_OFFSET_GOOD ||
 414             u->meta.gc_marker == gc_marker + GC_OFFSET_BAD ||
 415             u->meta.gc_marker == gc_marker + GC_OFFSET_IN_PATH)
 416                 return;
 417
 418         if (u->meta.in_cleanup_queue)
 419                 goto bad;
 420
 421         if (unit_check_gc(u))
 422                 goto good;
 423
 424         u->meta.gc_marker = gc_marker + GC_OFFSET_IN_PATH;
 425
 426         is_bad = true;
 427
 428         SET_FOREACH(other, u->meta.dependencies[UNIT_REFERENCED_BY], i) {
 429                 unit_gc_sweep(other, gc_marker);
 430
 431                 if (other->meta.gc_marker == gc_marker + GC_OFFSET_GOOD)
 432                         goto good;
 433
 434                 if (other->meta.gc_marker != gc_marker + GC_OFFSET_BAD)
 435                         is_bad = false;
 436         }
 437
 438         if (is_bad)
 439                 goto bad;
 440
 441         /* We were unable to find anything out about this entry, so
 442          * let's investigate it later */
 443         u->meta.gc_marker = gc_marker + GC_OFFSET_UNSURE;
 444         unit_add_to_gc_queue(u);
 445         return;
 446
 447 bad:
 448         /* We definitely know that this one is not useful anymore, so
 449          * let's mark it for deletion */
 450         u->meta.gc_marker = gc_marker + GC_OFFSET_BAD;
 451         unit_add_to_cleanup_queue(u);
 452         return;
 453
 454 good:
 455         u->meta.gc_marker = gc_marker + GC_OFFSET_GOOD;
 456 }
 457
 458 static unsigned manager_dispatch_gc_queue(Manager *m) {
 459         Meta *meta;
 460         unsigned n = 0;
 461         unsigned gc_marker;
 462
 463         assert(m);
 464
 465         if ((m->n_in_gc_queue < GC_QUEUE_ENTRIES_MAX) &&
 466             (m->gc_queue_timestamp <= 0 ||
 467              (m->gc_queue_timestamp + GC_QUEUE_USEC_MAX) > now(CLOCK_MONOTONIC)))
 468                 return 0;
 469
 470         log_debug("Running GC...");
 471
 472         m->gc_marker += _GC_OFFSET_MAX;
 473         if (m->gc_marker + _GC_OFFSET_MAX <= _GC_OFFSET_MAX)
 474                 m->gc_marker = 1;
 475
 476         gc_marker = m->gc_marker;
 477
 478         while ((meta = m->gc_queue)) {
 479                 assert(meta->in_gc_queue);
 480
 481                 unit_gc_sweep(UNIT(meta), gc_marker);
 482
 483                 LIST_REMOVE(Meta, gc_queue, m->gc_queue, meta);
 484                 meta->in_gc_queue = false;
 485
 486                 n++;
 487
 488                 if (meta->gc_marker == gc_marker + GC_OFFSET_BAD ||
 489                     meta->gc_marker == gc_marker + GC_OFFSET_UNSURE) {
 490                         log_debug("Collecting %s", meta->id);
 491                         meta->gc_marker = gc_marker + GC_OFFSET_BAD;
 492                         unit_add_to_cleanup_queue(UNIT(meta));
 493                 }
 494         }
 495
 496         m->n_in_gc_queue = 0;
 497         m->gc_queue_timestamp = 0;
 498
 499         return n;
 500 }
 501
 502 static void manager_clear_jobs_and_units(Manager *m) {
 503         Job *j;
 504         Unit *u;
 505
 506         assert(m);
 507
 508         while ((j = hashmap_first(m->transaction_jobs)))
 509                 job_free(j);
 510
 511         while ((u = hashmap_first(m->units)))
 512                 unit_free(u);
 513 }
 514
 515 void manager_free(Manager *m) {
 516         UnitType c;
 517
 518         assert(m);
 519
 520         manager_clear_jobs_and_units(m);
 521
 522         for (c = 0; c < _UNIT_TYPE_MAX; c++)
 523                 if (unit_vtable[c]->shutdown)
 524                         unit_vtable[c]->shutdown(m);
 525
 526         /* If we reexecute ourselves, we keep the root cgroup
 527          * around */
 528         manager_shutdown_cgroup(m, m->exit_code != MANAGER_REEXECUTE);
 529
 530         bus_done_api(m);
 531         bus_done_system(m);
 532
 533         hashmap_free(m->units);
 534         hashmap_free(m->jobs);
 535         hashmap_free(m->transaction_jobs);
 536         hashmap_free(m->watch_pids);
 537         hashmap_free(m->watch_bus);
 538
 539         if (m->epoll_fd >= 0)
 540                 close_nointr_nofail(m->epoll_fd);
 541         if (m->signal_watch.fd >= 0)
 542                 close_nointr_nofail(m->signal_watch.fd);
 543
 544         strv_free(m->unit_path);
 545         strv_free(m->sysvinit_path);
 546         strv_free(m->sysvrcnd_path);
 547
 548         free(m->cgroup_controller);
 549         free(m->cgroup_hierarchy);
 550
 551         hashmap_free(m->cgroup_bondings);
 552
 553         free(m);
 554 }
 555
 556 int manager_enumerate(Manager *m) {
 557         int r = 0, q;
 558         UnitType c;
 559
 560         assert(m);
 561
 562         /* Let's ask every type to load all units from disk/kernel
 563          * that it might know */
 564         for (c = 0; c < _UNIT_TYPE_MAX; c++)
 565                 if (unit_vtable[c]->enumerate)
 566                         if ((q = unit_vtable[c]->enumerate(m)) < 0)
 567                                 r = q;
 568
 569         manager_dispatch_load_queue(m);
 570         return r;
 571 }
 572
 573 int manager_coldplug(Manager *m) {
 574         int r = 0, q;
 575         Iterator i;
 576         Unit *u;
 577         char *k;
 578
 579         assert(m);
 580
 581         /* Then, let's set up their initial state. */
 582         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
 583
 584                 /* ignore aliases */
 585                 if (u->meta.id != k)
 586                         continue;
 587
 588                 if (UNIT_VTABLE(u)->coldplug)
 589                         if ((q = UNIT_VTABLE(u)->coldplug(u)) < 0)
 590                                 r = q;
 591         }
 592
 593         return r;
 594 }
 595
 596 int manager_startup(Manager *m, FILE *serialization, FDSet *fds) {
 597         int r, q;
 598
 599         assert(m);
 600
 601         /* First, enumerate what we can from all config files */
 602         r = manager_enumerate(m);
 603
 604         /* Second, deserialize if there is something to deserialize */
 605         if (serialization)
 606                 if ((q = manager_deserialize(m, serialization, fds)) < 0)
 607                         r = q;
 608
 609         /* Third, fire things up! */
 610         if ((q = manager_coldplug(m)) < 0)
 611                 r = q;
 612
 613         /* Now that the initial devices are available, let's see if we
 614          * can write the utmp file */
 615         manager_write_utmp_reboot(m);
 616
 617         return r;
 618 }
 619
 620 static void transaction_delete_job(Manager *m, Job *j, bool delete_dependencies) {
 621         assert(m);
 622         assert(j);
 623
 624         /* Deletes one job from the transaction */
 625
 626         manager_transaction_unlink_job(m, j, delete_dependencies);
 627
 628         if (!j->installed)
 629                 job_free(j);
 630 }
 631
 632 static void transaction_delete_unit(Manager *m, Unit *u) {
 633         Job *j;
 634
 635         /* Deletes all jobs associated with a certain unit from the
 636          * transaction */
 637
 638         while ((j = hashmap_get(m->transaction_jobs, u)))
 639                 transaction_delete_job(m, j, true);
 640 }
 641
 642 static void transaction_clean_dependencies(Manager *m) {
 643         Iterator i;
 644         Job *j;
 645
 646         assert(m);
 647
 648         /* Drops all dependencies of all installed jobs */
 649
 650         HASHMAP_FOREACH(j, m->jobs, i) {
 651                 while (j->subject_list)
 652                         job_dependency_free(j->subject_list);
 653                 while (j->object_list)
 654                         job_dependency_free(j->object_list);
 655         }
 656
 657         assert(!m->transaction_anchor);
 658 }
 659
 660 static void transaction_abort(Manager *m) {
 661         Job *j;
 662
 663         assert(m);
 664
 665         while ((j = hashmap_first(m->transaction_jobs)))
 666                 if (j->installed)
 667                         transaction_delete_job(m, j, true);
 668                 else
 669                         job_free(j);
 670
 671         assert(hashmap_isempty(m->transaction_jobs));
 672
 673         transaction_clean_dependencies(m);
 674 }
 675
 676 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
 677         JobDependency *l;
 678
 679         assert(m);
 680
 681         /* A recursive sweep through the graph that marks all units
 682          * that matter to the anchor job, i.e. are directly or
 683          * indirectly a dependency of the anchor job via paths that
 684          * are fully marked as mattering. */
 685
 686         if (j)
 687                 l = j->subject_list;
 688         else
 689                 l = m->transaction_anchor;
 690
 691         LIST_FOREACH(subject, l, l) {
 692
 693                 /* This link does not matter */
 694                 if (!l->matters)
 695                         continue;
 696
 697                 /* This unit has already been marked */
 698                 if (l->object->generation == generation)
 699                         continue;
 700
 701                 l->object->matters_to_anchor = true;
 702                 l->object->generation = generation;
 703
 704                 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
 705         }
 706 }
 707
 708 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
 709         JobDependency *l, *last;
 710
 711         assert(j);
 712         assert(other);
 713         assert(j->unit == other->unit);
 714         assert(!j->installed);
 715
 716         /* Merges 'other' into 'j' and then deletes j. */
 717
 718         j->type = t;
 719         j->state = JOB_WAITING;
 720         j->override = j->override || other->override;
 721
 722         j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
 723
 724         /* Patch us in as new owner of the JobDependency objects */
 725         last = NULL;
 726         LIST_FOREACH(subject, l, other->subject_list) {
 727                 assert(l->subject == other);
 728                 l->subject = j;
 729                 last = l;
 730         }
 731
 732         /* Merge both lists */
 733         if (last) {
 734                 last->subject_next = j->subject_list;
 735                 if (j->subject_list)
 736                         j->subject_list->subject_prev = last;
 737                 j->subject_list = other->subject_list;
 738         }
 739
 740         /* Patch us in as new owner of the JobDependency objects */
 741         last = NULL;
 742         LIST_FOREACH(object, l, other->object_list) {
 743                 assert(l->object == other);
 744                 l->object = j;
 745                 last = l;
 746         }
 747
 748         /* Merge both lists */
 749         if (last) {
 750                 last->object_next = j->object_list;
 751                 if (j->object_list)
 752                         j->object_list->object_prev = last;
 753                 j->object_list = other->object_list;
 754         }
 755
 756         /* Kill the other job */
 757         other->subject_list = NULL;
 758         other->object_list = NULL;
 759         transaction_delete_job(m, other, true);
 760 }
 761
 762 static int delete_one_unmergeable_job(Manager *m, Job *j) {
 763         Job *k;
 764
 765         assert(j);
 766
 767         /* Tries to delete one item in the linked list
 768          * j->transaction_next->transaction_next->... that conflicts
 769          * whith another one, in an attempt to make an inconsistent
 770          * transaction work. */
 771
 772         /* We rely here on the fact that if a merged with b does not
 773          * merge with c, either a or b merge with c neither */
 774         LIST_FOREACH(transaction, j, j)
 775                 LIST_FOREACH(transaction, k, j->transaction_next) {
 776                         Job *d;
 777
 778                         /* Is this one mergeable? Then skip it */
 779                         if (job_type_is_mergeable(j->type, k->type))
 780                                 continue;
 781
 782                         /* Ok, we found two that conflict, let's see if we can
 783                          * drop one of them */
 784                         if (!j->matters_to_anchor)
 785                                 d = j;
 786                         else if (!k->matters_to_anchor)
 787                                 d = k;
 788                         else
 789                                 return -ENOEXEC;
 790
 791                         /* Ok, we can drop one, so let's do so. */
 792                         log_debug("Trying to fix job merging by deleting job %s/%s", d->unit->meta.id, job_type_to_string(d->type));
 793                         transaction_delete_job(m, d, true);
 794                         return 0;
 795                 }
 796
 797         return -EINVAL;
 798 }
 799
 800 static int transaction_merge_jobs(Manager *m) {
 801         Job *j;
 802         Iterator i;
 803         int r;
 804
 805         assert(m);
 806
 807         /* First step, check whether any of the jobs for one specific
 808          * task conflict. If so, try to drop one of them. */
 809         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 810                 JobType t;
 811                 Job *k;
 812
 813                 t = j->type;
 814                 LIST_FOREACH(transaction, k, j->transaction_next) {
 815                         if ((r = job_type_merge(&t, k->type)) >= 0)
 816                                 continue;
 817
 818                         /* OK, we could not merge all jobs for this
 819                          * action. Let's see if we can get rid of one
 820                          * of them */
 821
 822                         if ((r = delete_one_unmergeable_job(m, j)) >= 0)
 823                                 /* Ok, we managed to drop one, now
 824                                  * let's ask our callers to call us
 825                                  * again after garbage collecting */
 826                                 return -EAGAIN;
 827
 828                         /* We couldn't merge anything. Failure */
 829                         return r;
 830                 }
 831         }
 832
 833         /* Second step, merge the jobs. */
 834         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 835                 JobType t = j->type;
 836                 Job *k;
 837
 838                 /* Merge all transactions */
 839                 LIST_FOREACH(transaction, k, j->transaction_next)
 840                         assert_se(job_type_merge(&t, k->type) == 0);
 841
 842                 /* If an active job is mergeable, merge it too */
 843                 if (j->unit->meta.job)
 844                         job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
 845
 846                 while ((k = j->transaction_next)) {
 847                         if (j->installed) {
 848                                 transaction_merge_and_delete_job(m, k, j, t);
 849                                 j = k;
 850                         } else
 851                                 transaction_merge_and_delete_job(m, j, k, t);
 852                 }
 853
 854                 assert(!j->transaction_next);
 855                 assert(!j->transaction_prev);
 856         }
 857
 858         return 0;
 859 }
 860
 861 static void transaction_drop_redundant(Manager *m) {
 862         bool again;
 863
 864         assert(m);
 865
 866         /* Goes through the transaction and removes all jobs that are
 867          * a noop */
 868
 869         do {
 870                 Job *j;
 871                 Iterator i;
 872
 873                 again = false;
 874
 875                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 876                         bool changes_something = false;
 877                         Job *k;
 878
 879                         LIST_FOREACH(transaction, k, j) {
 880
 881                                 if (!job_is_anchor(k) &&
 882                                     job_type_is_redundant(k->type, unit_active_state(k->unit)))
 883                                         continue;
 884
 885                                 changes_something = true;
 886                                 break;
 887                         }
 888
 889                         if (changes_something)
 890                                 continue;
 891
 892                         log_debug("Found redundant job %s/%s, dropping.", j->unit->meta.id, job_type_to_string(j->type));
 893                         transaction_delete_job(m, j, false);
 894                         again = true;
 895                         break;
 896                 }
 897
 898         } while (again);
 899 }
 900
 901 static bool unit_matters_to_anchor(Unit *u, Job *j) {
 902         assert(u);
 903         assert(!j->transaction_prev);
 904
 905         /* Checks whether at least one of the jobs for this unit
 906          * matters to the anchor. */
 907
 908         LIST_FOREACH(transaction, j, j)
 909                 if (j->matters_to_anchor)
 910                         return true;
 911
 912         return false;
 913 }
 914
 915 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation) {
 916         Iterator i;
 917         Unit *u;
 918         int r;
 919
 920         assert(m);
 921         assert(j);
 922         assert(!j->transaction_prev);
 923
 924         /* Does a recursive sweep through the ordering graph, looking
 925          * for a cycle. If we find cycle we try to break it. */
 926
 927         /* Did we find a cycle? */
 928         if (j->marker && j->generation == generation) {
 929                 Job *k;
 930
 931                 /* So, we already have been here. We have a
 932                  * cycle. Let's try to break it. We go backwards in
 933                  * our path and try to find a suitable job to
 934                  * remove. We use the marker to find our way back,
 935                  * since smart how we are we stored our way back in
 936                  * there. */
 937
 938                 log_debug("Found ordering cycle on %s/%s", j->unit->meta.id, job_type_to_string(j->type));
 939
 940                 for (k = from; k; k = (k->generation == generation ? k->marker : NULL)) {
 941
 942                         log_debug("Walked on cycle path to %s/%s", k->unit->meta.id, job_type_to_string(k->type));
 943
 944                         if (!k->installed &&
 945                             !unit_matters_to_anchor(k->unit, k)) {
 946                                 /* Ok, we can drop this one, so let's
 947                                  * do so. */
 948                                 log_debug("Breaking order cycle by deleting job %s/%s", k->unit->meta.id, job_type_to_string(k->type));
 949                                 transaction_delete_unit(m, k->unit);
 950                                 return -EAGAIN;
 951                         }
 952
 953                         /* Check if this in fact was the beginning of
 954                          * the cycle */
 955                         if (k == j)
 956                                 break;
 957                 }
 958
 959                 log_debug("Unable to break cycle");
 960
 961                 return -ENOEXEC;
 962         }
 963
 964         /* Make the marker point to where we come from, so that we can
 965          * find our way backwards if we want to break a cycle */
 966         j->marker = from;
 967         j->generation = generation;
 968
 969         /* We assume that the the dependencies are bidirectional, and
 970          * hence can ignore UNIT_AFTER */
 971         SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
 972                 Job *o;
 973
 974                 /* Is there a job for this unit? */
 975                 if (!(o = hashmap_get(m->transaction_jobs, u)))
 976
 977                         /* Ok, there is no job for this in the
 978                          * transaction, but maybe there is already one
 979                          * running? */
 980                         if (!(o = u->meta.job))
 981                                 continue;
 982
 983                 if ((r = transaction_verify_order_one(m, o, j, generation)) < 0)
 984                         return r;
 985         }
 986
 987         /* Ok, let's backtrack, and remember that this entry is not on
 988          * our path anymore. */
 989         j->marker = NULL;
 990
 991         return 0;
 992 }
 993
 994 static int transaction_verify_order(Manager *m, unsigned *generation) {
 995         Job *j;
 996         int r;
 997         Iterator i;
 998
 999         assert(m);
1000         assert(generation);
1001
1002         /* Check if the ordering graph is cyclic. If it is, try to fix
1003          * that up by dropping one of the jobs. */
1004
1005         HASHMAP_FOREACH(j, m->transaction_jobs, i)
1006                 if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0)
1007                         return r;
1008
1009         return 0;
1010 }
1011
1012 static void transaction_collect_garbage(Manager *m) {
1013         bool again;
1014
1015         assert(m);
1016
1017         /* Drop jobs that are not required by any other job */
1018
1019         do {
1020                 Iterator i;
1021                 Job *j;
1022
1023                 again = false;
1024
1025                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1026                         if (j->object_list)
1027                                 continue;
1028
1029                         log_debug("Garbage collecting job %s/%s", j->unit->meta.id, job_type_to_string(j->type));
1030                         transaction_delete_job(m, j, true);
1031                         again = true;
1032                         break;
1033                 }
1034
1035         } while (again);
1036 }
1037
1038 static int transaction_is_destructive(Manager *m) {
1039         Iterator i;
1040         Job *j;
1041
1042         assert(m);
1043
1044         /* Checks whether applying this transaction means that
1045          * existing jobs would be replaced */
1046
1047         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1048
1049                 /* Assume merged */
1050                 assert(!j->transaction_prev);
1051                 assert(!j->transaction_next);
1052
1053                 if (j->unit->meta.job &&
1054                     j->unit->meta.job != j &&
1055                     !job_type_is_superset(j->type, j->unit->meta.job->type))
1056                         return -EEXIST;
1057         }
1058
1059         return 0;
1060 }
1061
1062 static void transaction_minimize_impact(Manager *m) {
1063         bool again;
1064         assert(m);
1065
1066         /* Drops all unnecessary jobs that reverse already active jobs
1067          * or that stop a running service. */
1068
1069         do {
1070                 Job *j;
1071                 Iterator i;
1072
1073                 again = false;
1074
1075                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1076                         LIST_FOREACH(transaction, j, j) {
1077                                 bool stops_running_service, changes_existing_job;
1078
1079                                 /* If it matters, we shouldn't drop it */
1080                                 if (j->matters_to_anchor)
1081                                         continue;
1082
1083                                 /* Would this stop a running service?
1084                                  * Would this change an existing job?
1085                                  * If so, let's drop this entry */
1086
1087                                 stops_running_service =
1088                                         j->type == JOB_STOP && UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(j->unit));
1089
1090                                 changes_existing_job =
1091                                         j->unit->meta.job && job_type_is_conflicting(j->type, j->unit->meta.job->state);
1092
1093                                 if (!stops_running_service && !changes_existing_job)
1094                                         continue;
1095
1096                                 if (stops_running_service)
1097                                         log_debug("%s/%s would stop a running service.", j->unit->meta.id, job_type_to_string(j->type));
1098
1099                                 if (changes_existing_job)
1100                                         log_debug("%s/%s would change existing job.", j->unit->meta.id, job_type_to_string(j->type));
1101
1102                                 /* Ok, let's get rid of this */
1103                                 log_debug("Deleting %s/%s to minimize impact.", j->unit->meta.id, job_type_to_string(j->type));
1104
1105                                 transaction_delete_job(m, j, true);
1106                                 again = true;
1107                                 break;
1108                         }
1109
1110                         if (again)
1111                                 break;
1112                 }
1113
1114         } while (again);
1115 }
1116
1117 static int transaction_apply(Manager *m) {
1118         Iterator i;
1119         Job *j;
1120         int r;
1121
1122         /* Moves the transaction jobs to the set of active jobs */
1123
1124         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1125                 /* Assume merged */
1126                 assert(!j->transaction_prev);
1127                 assert(!j->transaction_next);
1128
1129                 if (j->installed)
1130                         continue;
1131
1132                 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
1133                         goto rollback;
1134         }
1135
1136         while ((j = hashmap_steal_first(m->transaction_jobs))) {
1137                 if (j->installed)
1138                         continue;
1139
1140                 if (j->unit->meta.job)
1141                         job_free(j->unit->meta.job);
1142
1143                 j->unit->meta.job = j;
1144                 j->installed = true;
1145
1146                 /* We're fully installed. Now let's free data we don't
1147                  * need anymore. */
1148
1149                 assert(!j->transaction_next);
1150                 assert(!j->transaction_prev);
1151
1152                 job_add_to_run_queue(j);
1153                 job_add_to_dbus_queue(j);
1154         }
1155
1156         /* As last step, kill all remaining job dependencies. */
1157         transaction_clean_dependencies(m);
1158
1159         return 0;
1160
1161 rollback:
1162
1163         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1164                 if (j->installed)
1165                         continue;
1166
1167                 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
1168         }
1169
1170         return r;
1171 }
1172
1173 static int transaction_activate(Manager *m, JobMode mode) {
1174         int r;
1175         unsigned generation = 1;
1176
1177         assert(m);
1178
1179         /* This applies the changes recorded in transaction_jobs to
1180          * the actual list of jobs, if possible. */
1181
1182         /* First step: figure out which jobs matter */
1183         transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
1184
1185         /* Second step: Try not to stop any running services if
1186          * we don't have to. Don't try to reverse running
1187          * jobs if we don't have to. */
1188         transaction_minimize_impact(m);
1189
1190         /* Third step: Drop redundant jobs */
1191         transaction_drop_redundant(m);
1192
1193         for (;;) {
1194                 /* Fourth step: Let's remove unneeded jobs that might
1195                  * be lurking. */
1196                 transaction_collect_garbage(m);
1197
1198                 /* Fifth step: verify order makes sense and correct
1199                  * cycles if necessary and possible */
1200                 if ((r = transaction_verify_order(m, &generation)) >= 0)
1201                         break;
1202
1203                 if (r != -EAGAIN) {
1204                         log_debug("Requested transaction contains an unfixable cyclic ordering dependency: %s", strerror(-r));
1205                         goto rollback;
1206                 }
1207
1208                 /* Let's see if the resulting transaction ordering
1209                  * graph is still cyclic... */
1210         }
1211
1212         for (;;) {
1213                 /* Sixth step: let's drop unmergeable entries if
1214                  * necessary and possible, merge entries we can
1215                  * merge */
1216                 if ((r = transaction_merge_jobs(m)) >= 0)
1217                         break;
1218
1219                 if (r != -EAGAIN) {
1220                         log_debug("Requested transaction contains unmergable jobs: %s", strerror(-r));
1221                         goto rollback;
1222                 }
1223
1224                 /* Seventh step: an entry got dropped, let's garbage
1225                  * collect its dependencies. */
1226                 transaction_collect_garbage(m);
1227
1228                 /* Let's see if the resulting transaction still has
1229                  * unmergeable entries ... */
1230         }
1231
1232         /* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */
1233         transaction_drop_redundant(m);
1234
1235         /* Ninth step: check whether we can actually apply this */
1236         if (mode == JOB_FAIL)
1237                 if ((r = transaction_is_destructive(m)) < 0) {
1238                         log_debug("Requested transaction contradicts existing jobs: %s", strerror(-r));
1239                         goto rollback;
1240                 }
1241
1242         /* Tenth step: apply changes */
1243         if ((r = transaction_apply(m)) < 0) {
1244                 log_debug("Failed to apply transaction: %s", strerror(-r));
1245                 goto rollback;
1246         }
1247
1248         assert(hashmap_isempty(m->transaction_jobs));
1249         assert(!m->transaction_anchor);
1250
1251         return 0;
1252
1253 rollback:
1254         transaction_abort(m);
1255         return r;
1256 }
1257
1258 static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool override, bool *is_new) {
1259         Job *j, *f;
1260         int r;
1261
1262         assert(m);
1263         assert(unit);
1264
1265         /* Looks for an axisting prospective job and returns that. If
1266          * it doesn't exist it is created and added to the prospective
1267          * jobs list. */
1268
1269         f = hashmap_get(m->transaction_jobs, unit);
1270
1271         LIST_FOREACH(transaction, j, f) {
1272                 assert(j->unit == unit);
1273
1274                 if (j->type == type) {
1275                         if (is_new)
1276                                 *is_new = false;
1277                         return j;
1278                 }
1279         }
1280
1281         if (unit->meta.job && unit->meta.job->type == type)
1282                 j = unit->meta.job;
1283         else if (!(j = job_new(m, type, unit)))
1284                 return NULL;
1285
1286         j->generation = 0;
1287         j->marker = NULL;
1288         j->matters_to_anchor = false;
1289         j->override = override;
1290
1291         LIST_PREPEND(Job, transaction, f, j);
1292
1293         if ((r = hashmap_replace(m->transaction_jobs, unit, f)) < 0) {
1294                 job_free(j);
1295                 return NULL;
1296         }
1297
1298         if (is_new)
1299                 *is_new = true;
1300
1301         log_debug("Added job %s/%s to transaction.", unit->meta.id, job_type_to_string(type));
1302
1303         return j;
1304 }
1305
1306 void manager_transaction_unlink_job(Manager *m, Job *j, bool delete_dependencies) {
1307         assert(m);
1308         assert(j);
1309
1310         if (j->transaction_prev)
1311                 j->transaction_prev->transaction_next = j->transaction_next;
1312         else if (j->transaction_next)
1313                 hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
1314         else
1315                 hashmap_remove_value(m->transaction_jobs, j->unit, j);
1316
1317         if (j->transaction_next)
1318                 j->transaction_next->transaction_prev = j->transaction_prev;
1319
1320         j->transaction_prev = j->transaction_next = NULL;
1321
1322         while (j->subject_list)
1323                 job_dependency_free(j->subject_list);
1324
1325         while (j->object_list) {
1326                 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
1327
1328                 job_dependency_free(j->object_list);
1329
1330                 if (other && delete_dependencies) {
1331                         log_debug("Deleting job %s/%s as dependency of job %s/%s",
1332                                   other->unit->meta.id, job_type_to_string(other->type),
1333                                   j->unit->meta.id, job_type_to_string(j->type));
1334                         transaction_delete_job(m, other, delete_dependencies);
1335                 }
1336         }
1337 }
1338
1339 static int transaction_add_job_and_dependencies(
1340                 Manager *m,
1341                 JobType type,
1342                 Unit *unit,
1343                 Job *by,
1344                 bool matters,
1345                 bool override,
1346                 Job **_ret) {
1347         Job *ret;
1348         Iterator i;
1349         Unit *dep;
1350         int r;
1351         bool is_new;
1352
1353         assert(m);
1354         assert(type < _JOB_TYPE_MAX);
1355         assert(unit);
1356
1357         if (unit->meta.load_state != UNIT_LOADED)
1358                 return -EINVAL;
1359
1360         if (!unit_job_is_applicable(unit, type))
1361                 return -EBADR;
1362
1363         /* First add the job. */
1364         if (!(ret = transaction_add_one_job(m, type, unit, override, &is_new)))
1365                 return -ENOMEM;
1366
1367         /* Then, add a link to the job. */
1368         if (!job_dependency_new(by, ret, matters))
1369                 return -ENOMEM;
1370
1371         if (is_new) {
1372                 /* Finally, recursively add in all dependencies. */
1373                 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
1374                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
1375                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
1376                                         goto fail;
1377
1378                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
1379                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !override, override, NULL)) < 0 && r != -EBADR)
1380                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
1381
1382                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
1383                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, false, NULL)) < 0)
1384                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
1385
1386                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
1387                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
1388                                         goto fail;
1389
1390                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE_OVERRIDABLE], i)
1391                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !override, override, NULL)) < 0 && r != -EBADR)
1392                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
1393
1394                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
1395                                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
1396                                         goto fail;
1397
1398                 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
1399
1400                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
1401                                 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
1402                                         goto fail;
1403                 }
1404
1405                 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
1406         }
1407
1408         if (_ret)
1409                 *_ret = ret;
1410
1411         return 0;
1412
1413 fail:
1414         return r;
1415 }
1416
1417 static int transaction_add_isolate_jobs(Manager *m) {
1418         Iterator i;
1419         Unit *u;
1420         char *k;
1421         int r;
1422
1423         assert(m);
1424
1425         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
1426
1427                 /* ignore aliases */
1428                 if (u->meta.id != k)
1429                         continue;
1430
1431                 if (UNIT_VTABLE(u)->no_isolate)
1432                         continue;
1433
1434                 /* No need to stop inactive jobs */
1435                 if (unit_active_state(u) == UNIT_INACTIVE)
1436                         continue;
1437
1438                 /* Is there already something listed for this? */
1439                 if (hashmap_get(m->transaction_jobs, u))
1440                         continue;
1441
1442                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, u, NULL, true, false, NULL)) < 0)
1443                         log_warning("Cannot add isolate job for unit %s, ignoring: %s", u->meta.id, strerror(-r));
1444         }
1445
1446         return 0;
1447 }
1448
1449 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool override, Job **_ret) {
1450         int r;
1451         Job *ret;
1452
1453         assert(m);
1454         assert(type < _JOB_TYPE_MAX);
1455         assert(unit);
1456         assert(mode < _JOB_MODE_MAX);
1457
1458         if (mode == JOB_ISOLATE && type != JOB_START)
1459                 return -EINVAL;
1460
1461         log_debug("Trying to enqueue job %s/%s", unit->meta.id, job_type_to_string(type));
1462
1463         if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, override, &ret)) < 0) {
1464                 transaction_abort(m);
1465                 return r;
1466         }
1467
1468         if (mode == JOB_ISOLATE)
1469                 if ((r = transaction_add_isolate_jobs(m)) < 0) {
1470                         transaction_abort(m);
1471                         return r;
1472                 }
1473
1474         if ((r = transaction_activate(m, mode)) < 0)
1475                 return r;
1476
1477         log_debug("Enqueued job %s/%s as %u", unit->meta.id, job_type_to_string(type), (unsigned) ret->id);
1478
1479         if (_ret)
1480                 *_ret = ret;
1481
1482         return 0;
1483 }
1484
1485 int manager_add_job_by_name(Manager *m, JobType type, const char *name, JobMode mode, bool override, Job **_ret) {
1486         Unit *unit;
1487         int r;
1488
1489         assert(m);
1490         assert(type < _JOB_TYPE_MAX);
1491         assert(name);
1492         assert(mode < _JOB_MODE_MAX);
1493
1494         if ((r = manager_load_unit(m, name, NULL, &unit)) < 0)
1495                 return r;
1496
1497         return manager_add_job(m, type, unit, mode, override, _ret);
1498 }
1499
1500 Job *manager_get_job(Manager *m, uint32_t id) {
1501         assert(m);
1502
1503         return hashmap_get(m->jobs, UINT32_TO_PTR(id));
1504 }
1505
1506 Unit *manager_get_unit(Manager *m, const char *name) {
1507         assert(m);
1508         assert(name);
1509
1510         return hashmap_get(m->units, name);
1511 }
1512
1513 unsigned manager_dispatch_load_queue(Manager *m) {
1514         Meta *meta;
1515         unsigned n = 0;
1516
1517         assert(m);
1518
1519         /* Make sure we are not run recursively */
1520         if (m->dispatching_load_queue)
1521                 return 0;
1522
1523         m->dispatching_load_queue = true;
1524
1525         /* Dispatches the load queue. Takes a unit from the queue and
1526          * tries to load its data until the queue is empty */
1527
1528         while ((meta = m->load_queue)) {
1529                 assert(meta->in_load_queue);
1530
1531                 unit_load(UNIT(meta));
1532                 n++;
1533         }
1534
1535         m->dispatching_load_queue = false;
1536         return n;
1537 }
1538
1539 int manager_load_unit(Manager *m, const char *name, const char *path, Unit **_ret) {
1540         Unit *ret;
1541         int r;
1542
1543         assert(m);
1544         assert(name || path);
1545
1546         /* This will load the service information files, but not actually
1547          * start any services or anything. */
1548
1549         if (path && !is_path(path))
1550                 return -EINVAL;
1551
1552         if (!name)
1553                 name = file_name_from_path(path);
1554
1555         if (!unit_name_is_valid(name))
1556                 return -EINVAL;
1557
1558         if ((ret = manager_get_unit(m, name))) {
1559                 *_ret = ret;
1560                 return 0;
1561         }
1562
1563         if (!(ret = unit_new(m)))
1564                 return -ENOMEM;
1565
1566         if (path)
1567                 if (!(ret->meta.fragment_path = strdup(path))) {
1568                         unit_free(ret);
1569                         return -ENOMEM;
1570                 }
1571
1572         if ((r = unit_add_name(ret, name)) < 0) {
1573                 unit_free(ret);
1574                 return r;
1575         }
1576
1577         unit_add_to_load_queue(ret);
1578         unit_add_to_dbus_queue(ret);
1579
1580         manager_dispatch_load_queue(m);
1581
1582         if (_ret)
1583                 *_ret = unit_follow_merge(ret);
1584
1585         return 0;
1586 }
1587
1588 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
1589         Iterator i;
1590         Job *j;
1591
1592         assert(s);
1593         assert(f);
1594
1595         HASHMAP_FOREACH(j, s->jobs, i)
1596                 job_dump(j, f, prefix);
1597 }
1598
1599 void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
1600         Iterator i;
1601         Unit *u;
1602         const char *t;
1603
1604         assert(s);
1605         assert(f);
1606
1607         HASHMAP_FOREACH_KEY(u, t, s->units, i)
1608                 if (u->meta.id == t)
1609                         unit_dump(u, f, prefix);
1610 }
1611
1612 void manager_clear_jobs(Manager *m) {
1613         Job *j;
1614
1615         assert(m);
1616
1617         transaction_abort(m);
1618
1619         while ((j = hashmap_first(m->jobs)))
1620                 job_free(j);
1621 }
1622
1623 unsigned manager_dispatch_run_queue(Manager *m) {
1624         Job *j;
1625         unsigned n = 0;
1626
1627         if (m->dispatching_run_queue)
1628                 return 0;
1629
1630         m->dispatching_run_queue = true;
1631
1632         while ((j = m->run_queue)) {
1633                 assert(j->installed);
1634                 assert(j->in_run_queue);
1635
1636                 job_run_and_invalidate(j);
1637                 n++;
1638         }
1639
1640         m->dispatching_run_queue = false;
1641         return n;
1642 }
1643
1644 unsigned manager_dispatch_dbus_queue(Manager *m) {
1645         Job *j;
1646         Meta *meta;
1647         unsigned n = 0;
1648
1649         assert(m);
1650
1651         if (m->dispatching_dbus_queue)
1652                 return 0;
1653
1654         m->dispatching_dbus_queue = true;
1655
1656         while ((meta = m->dbus_unit_queue)) {
1657                 assert(meta->in_dbus_queue);
1658
1659                 bus_unit_send_change_signal(UNIT(meta));
1660                 n++;
1661         }
1662
1663         while ((j = m->dbus_job_queue)) {
1664                 assert(j->in_dbus_queue);
1665
1666                 bus_job_send_change_signal(j);
1667                 n++;
1668         }
1669
1670         m->dispatching_dbus_queue = false;
1671         return n;
1672 }
1673
1674 static int manager_dispatch_sigchld(Manager *m) {
1675         assert(m);
1676
1677         for (;;) {
1678                 siginfo_t si;
1679                 Unit *u;
1680
1681                 zero(si);
1682
1683                 /* First we call waitd() for a PID and do not reap the
1684                  * zombie. That way we can still access /proc/$PID for
1685                  * it while it is a zombie. */
1686                 if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG|WNOWAIT) < 0) {
1687
1688                         if (errno == ECHILD)
1689                                 break;
1690
1691                         if (errno == EINTR)
1692                                 continue;
1693
1694                         return -errno;
1695                 }
1696
1697                 if (si.si_pid <= 0)
1698                         break;
1699
1700                 if (si.si_code == CLD_EXITED || si.si_code == CLD_KILLED || si.si_code == CLD_DUMPED) {
1701                         char *name = NULL;
1702
1703                         get_process_name(si.si_pid, &name);
1704                         log_debug("Got SIGCHLD for process %llu (%s)", (unsigned long long) si.si_pid, strna(name));
1705                         free(name);
1706                 }
1707
1708                 /* And now, we actually reap the zombie. */
1709                 if (waitid(P_PID, si.si_pid, &si, WEXITED) < 0) {
1710                         if (errno == EINTR)
1711                                 continue;
1712
1713                         return -errno;
1714                 }
1715
1716                 if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
1717                         continue;
1718
1719                 log_debug("Child %llu died (code=%s, status=%i/%s)",
1720                           (long long unsigned) si.si_pid,
1721                           sigchld_code_to_string(si.si_code),
1722                           si.si_status,
1723                           strna(si.si_code == CLD_EXITED ? exit_status_to_string(si.si_status) : strsignal(si.si_status)));
1724
1725                 if (!(u = hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid))))
1726                         continue;
1727
1728                 log_debug("Child %llu belongs to %s", (long long unsigned) si.si_pid, u->meta.id);
1729
1730                 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
1731         }
1732
1733         return 0;
1734 }
1735
1736 static void manager_start_target(Manager *m, const char *name) {
1737         int r;
1738
1739         if ((r = manager_add_job_by_name(m, JOB_START, name, JOB_REPLACE, true, NULL)) < 0)
1740                 log_error("Failed to enqueue %s job: %s", name, strerror(-r));
1741 }
1742
1743 static int manager_process_signal_fd(Manager *m) {
1744         ssize_t n;
1745         struct signalfd_siginfo sfsi;
1746         bool sigchld = false;
1747
1748         assert(m);
1749
1750         for (;;) {
1751                 if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
1752
1753                         if (n >= 0)
1754                                 return -EIO;
1755
1756                         if (errno == EAGAIN)
1757                                 break;
1758
1759                         return -errno;
1760                 }
1761
1762                 switch (sfsi.ssi_signo) {
1763
1764                 case SIGCHLD:
1765                         sigchld = true;
1766                         break;
1767
1768                 case SIGINT:
1769                 case SIGTERM:
1770
1771                         if (m->running_as == MANAGER_INIT) {
1772                                 manager_start_target(m, SPECIAL_CTRL_ALT_DEL_TARGET);
1773                                 break;
1774                         }
1775
1776                         m->exit_code = MANAGER_EXIT;
1777                         return 0;
1778
1779                 case SIGWINCH:
1780
1781                         if (m->running_as == MANAGER_INIT)
1782                                 manager_start_target(m, SPECIAL_KBREQUEST_TARGET);
1783
1784                         /* This is a nop on non-init */
1785                         break;
1786
1787                 case SIGPWR:
1788                         if (m->running_as == MANAGER_INIT)
1789                                 manager_start_target(m, SPECIAL_SIGPWR_TARGET);
1790
1791                         /* This is a nop on non-init */
1792                         break;
1793
1794                 case SIGUSR1:
1795                         manager_dump_units(m, stdout, "\t");
1796                         manager_dump_jobs(m, stdout, "\t");
1797                         break;
1798
1799                 case SIGUSR2:  {
1800                         Unit *u;
1801
1802                         u = manager_get_unit(m, SPECIAL_DBUS_SERVICE);
1803
1804                         if (!u || UNIT_IS_ACTIVE_OR_RELOADING(unit_active_state(u))) {
1805                                 log_info("Trying to reconnect to bus...");
1806                                 bus_init_system(m);
1807                                 bus_init_api(m);
1808                         }
1809
1810                         if (!u || !UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u))) {
1811                                 log_info("Loading D-Bus service...");
1812                                 manager_start_target(m, SPECIAL_DBUS_SERVICE);
1813                         }
1814
1815                         break;
1816                 }
1817
1818                 case SIGHUP:
1819                         m->exit_code = MANAGER_RELOAD;
1820                         break;
1821
1822                 default:
1823                         log_info("Got unhandled signal <%s>.", strsignal(sfsi.ssi_signo));
1824                 }
1825         }
1826
1827         if (sigchld)
1828                 return manager_dispatch_sigchld(m);
1829
1830         return 0;
1831 }
1832
1833 static int process_event(Manager *m, struct epoll_event *ev) {
1834         int r;
1835         Watch *w;
1836
1837         assert(m);
1838         assert(ev);
1839
1840         assert(w = ev->data.ptr);
1841
1842         switch (w->type) {
1843
1844         case WATCH_SIGNAL:
1845
1846                 /* An incoming signal? */
1847                 if (ev->events != EPOLLIN)
1848                         return -EINVAL;
1849
1850                 if ((r = manager_process_signal_fd(m)) < 0)
1851                         return r;
1852
1853                 break;
1854
1855         case WATCH_FD:
1856
1857                 /* Some fd event, to be dispatched to the units */
1858                 UNIT_VTABLE(w->data.unit)->fd_event(w->data.unit, w->fd, ev->events, w);
1859                 break;
1860
1861         case WATCH_TIMER: {
1862                 uint64_t v;
1863                 ssize_t k;
1864
1865                 /* Some timer event, to be dispatched to the units */
1866                 if ((k = read(w->fd, &v, sizeof(v))) != sizeof(v)) {
1867
1868                         if (k < 0 && (errno == EINTR || errno == EAGAIN))
1869                                 break;
1870
1871                         return k < 0 ? -errno : -EIO;
1872                 }
1873
1874                 UNIT_VTABLE(w->data.unit)->timer_event(w->data.unit, v, w);
1875                 break;
1876         }
1877
1878         case WATCH_MOUNT:
1879                 /* Some mount table change, intended for the mount subsystem */
1880                 mount_fd_event(m, ev->events);
1881                 break;
1882
1883         case WATCH_UDEV:
1884                 /* Some notification from udev, intended for the device subsystem */
1885                 device_fd_event(m, ev->events);
1886                 break;
1887
1888         case WATCH_DBUS_WATCH:
1889                 bus_watch_event(m, w, ev->events);
1890                 break;
1891
1892         case WATCH_DBUS_TIMEOUT:
1893                 bus_timeout_event(m, w, ev->events);
1894                 break;
1895
1896         default:
1897                 assert_not_reached("Unknown epoll event type.");
1898         }
1899
1900         return 0;
1901 }
1902
1903 int manager_loop(Manager *m) {
1904         int r;
1905
1906         RATELIMIT_DEFINE(rl, 1*USEC_PER_SEC, 1000);
1907
1908         assert(m);
1909         m->exit_code = MANAGER_RUNNING;
1910
1911         while (m->exit_code == MANAGER_RUNNING) {
1912                 struct epoll_event event;
1913                 int n;
1914
1915                 if (!ratelimit_test(&rl)) {
1916                         /* Yay, something is going seriously wrong, pause a little */
1917                         log_warning("Looping too fast. Throttling execution a little.");
1918                         sleep(1);
1919                 }
1920
1921                 if (manager_dispatch_cleanup_queue(m) > 0)
1922                         continue;
1923
1924                 if (manager_dispatch_gc_queue(m) > 0)
1925                         continue;
1926
1927                 if (manager_dispatch_load_queue(m) > 0)
1928                         continue;
1929
1930                 if (manager_dispatch_run_queue(m) > 0)
1931                         continue;
1932
1933                 if (bus_dispatch(m) > 0)
1934                         continue;
1935
1936                 if (manager_dispatch_dbus_queue(m) > 0)
1937                         continue;
1938
1939                 if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) {
1940
1941                         if (errno == -EINTR)
1942                                 continue;
1943
1944                         return -errno;
1945                 }
1946
1947                 assert(n == 1);
1948
1949                 if ((r = process_event(m, &event)) < 0)
1950                         return r;
1951         }
1952
1953         return m->exit_code;
1954 }
1955
1956 int manager_get_unit_from_dbus_path(Manager *m, const char *s, Unit **_u) {
1957         char *n;
1958         Unit *u;
1959
1960         assert(m);
1961         assert(s);
1962         assert(_u);
1963
1964         if (!startswith(s, "/org/freedesktop/systemd1/unit/"))
1965                 return -EINVAL;
1966
1967         if (!(n = bus_path_unescape(s+31)))
1968                 return -ENOMEM;
1969
1970         u = manager_get_unit(m, n);
1971         free(n);
1972
1973         if (!u)
1974                 return -ENOENT;
1975
1976         *_u = u;
1977
1978         return 0;
1979 }
1980
1981 int manager_get_job_from_dbus_path(Manager *m, const char *s, Job **_j) {
1982         Job *j;
1983         unsigned id;
1984         int r;
1985
1986         assert(m);
1987         assert(s);
1988         assert(_j);
1989
1990         if (!startswith(s, "/org/freedesktop/systemd1/job/"))
1991                 return -EINVAL;
1992
1993         if ((r = safe_atou(s + 30, &id)) < 0)
1994                 return r;
1995
1996         if (!(j = manager_get_job(m, id)))
1997                 return -ENOENT;
1998
1999         *_j = j;
2000
2001         return 0;
2002 }
2003
2004 static bool manager_utmp_good(Manager *m) {
2005         int r;
2006
2007         assert(m);
2008
2009         if ((r = mount_path_is_mounted(m, _PATH_UTMPX)) <= 0) {
2010
2011                 if (r < 0)
2012                         log_warning("Failed to determine whether " _PATH_UTMPX " is mounted: %s", strerror(-r));
2013
2014                 return false;
2015         }
2016
2017         return true;
2018 }
2019
2020 void manager_write_utmp_reboot(Manager *m) {
2021         int r;
2022
2023         assert(m);
2024
2025         if (m->utmp_reboot_written)
2026                 return;
2027
2028         if (m->running_as != MANAGER_INIT)
2029                 return;
2030
2031         if (!manager_utmp_good(m))
2032                 return;
2033
2034         if ((r = utmp_put_reboot(m->boot_timestamp)) < 0) {
2035
2036                 if (r != -ENOENT && r != -EROFS)
2037                         log_warning("Failed to write utmp/wtmp: %s", strerror(-r));
2038
2039                 return;
2040         }
2041
2042         m->utmp_reboot_written = true;
2043 }
2044
2045 void manager_write_utmp_runlevel(Manager *m, Unit *u) {
2046         int runlevel, r;
2047
2048         assert(m);
2049         assert(u);
2050
2051         if (u->meta.type != UNIT_TARGET)
2052                 return;
2053
2054         if (m->running_as != MANAGER_INIT)
2055                 return;
2056
2057         if (!manager_utmp_good(m))
2058                 return;
2059
2060         if ((runlevel = target_get_runlevel(TARGET(u))) <= 0)
2061                 return;
2062
2063         if ((r = utmp_put_runlevel(0, runlevel, 0)) < 0) {
2064
2065                 if (r != -ENOENT && r != -EROFS)
2066                         log_warning("Failed to write utmp/wtmp: %s", strerror(-r));
2067         }
2068 }
2069
2070 void manager_dispatch_bus_name_owner_changed(
2071                 Manager *m,
2072                 const char *name,
2073                 const char* old_owner,
2074                 const char *new_owner) {
2075
2076         Unit *u;
2077
2078         assert(m);
2079         assert(name);
2080
2081         if (!(u = hashmap_get(m->watch_bus, name)))
2082                 return;
2083
2084         UNIT_VTABLE(u)->bus_name_owner_change(u, name, old_owner, new_owner);
2085 }
2086
2087 void manager_dispatch_bus_query_pid_done(
2088                 Manager *m,
2089                 const char *name,
2090                 pid_t pid) {
2091
2092         Unit *u;
2093
2094         assert(m);
2095         assert(name);
2096         assert(pid >= 1);
2097
2098         if (!(u = hashmap_get(m->watch_bus, name)))
2099                 return;
2100
2101         UNIT_VTABLE(u)->bus_query_pid_done(u, name, pid);
2102 }
2103
2104 int manager_open_serialization(FILE **_f) {
2105         char *path;
2106         mode_t saved_umask;
2107         int fd;
2108         FILE *f;
2109
2110         assert(_f);
2111
2112         if (asprintf(&path, "/dev/shm/systemd-%u.dump-XXXXXX", (unsigned) getpid()) < 0)
2113                 return -ENOMEM;
2114
2115         saved_umask = umask(0077);
2116         fd = mkostemp(path, O_RDWR|O_CLOEXEC);
2117         umask(saved_umask);
2118
2119         if (fd < 0) {
2120                 free(path);
2121                 return -errno;
2122         }
2123
2124         unlink(path);
2125
2126         log_debug("Serializing state to %s", path);
2127         free(path);
2128
2129         if (!(f = fdopen(fd, "w+")) < 0)
2130                 return -errno;
2131
2132         *_f = f;
2133
2134         return 0;
2135 }
2136
2137 int manager_serialize(Manager *m, FILE *f, FDSet *fds) {
2138         Iterator i;
2139         Unit *u;
2140         const char *t;
2141         int r;
2142
2143         assert(m);
2144         assert(f);
2145         assert(fds);
2146
2147         HASHMAP_FOREACH_KEY(u, t, m->units, i) {
2148                 if (u->meta.id != t)
2149                         continue;
2150
2151                 if (!unit_can_serialize(u))
2152                         continue;
2153
2154                 /* Start marker */
2155                 fputs(u->meta.id, f);
2156                 fputc('\n', f);
2157
2158                 if ((r = unit_serialize(u, f, fds)) < 0)
2159                         return r;
2160         }
2161
2162         if (ferror(f))
2163                 return -EIO;
2164
2165         return 0;
2166 }
2167
2168 int manager_deserialize(Manager *m, FILE *f, FDSet *fds) {
2169         int r = 0;
2170
2171         assert(m);
2172         assert(f);
2173
2174         log_debug("Deserializing state...");
2175
2176         for (;;) {
2177                 Unit *u;
2178                 char name[UNIT_NAME_MAX+2];
2179
2180                 /* Start marker */
2181                 if (!fgets(name, sizeof(name), f)) {
2182                         if (feof(f))
2183                                 break;
2184
2185                         return -errno;
2186                 }
2187
2188                 char_array_0(name);
2189
2190                 if ((r = manager_load_unit(m, strstrip(name), NULL, &u)) < 0)
2191                         return r;
2192
2193                 if ((r = unit_deserialize(u, f, fds)) < 0)
2194                         return r;
2195         }
2196
2197         if (ferror(f))
2198                 return -EIO;
2199
2200         return 0;
2201 }
2202
2203 int manager_reload(Manager *m) {
2204         int r, q;
2205         FILE *f;
2206         FDSet *fds;
2207
2208         assert(m);
2209
2210         if ((r = manager_open_serialization(&f)) < 0)
2211                 return r;
2212
2213         if (!(fds = fdset_new())) {
2214                 r = -ENOMEM;
2215                 goto finish;
2216         }
2217
2218         if ((r = manager_serialize(m, f, fds)) < 0)
2219                 goto finish;
2220
2221         if (fseeko(f, 0, SEEK_SET) < 0) {
2222                 r = -errno;
2223                 goto finish;
2224         }
2225
2226         /* From here on there is no way back. */
2227         manager_clear_jobs_and_units(m);
2228
2229         /* First, enumerate what we can from all config files */
2230         if ((q = manager_enumerate(m)) < 0)
2231                 r = q;
2232
2233         /* Second, deserialize our stored data */
2234         if ((q = manager_deserialize(m, f, fds)) < 0)
2235                 r = q;
2236
2237         fclose(f);
2238         f = NULL;
2239
2240         /* Third, fire things up! */
2241         if ((q = manager_coldplug(m)) < 0)
2242                 r = q;
2243
2244 finish:
2245         if (f)
2246                 fclose(f);
2247
2248         if (fds)
2249                 fdset_free(fds);
2250
2251         return r;
2252 }
2253
2254 static const char* const manager_running_as_table[_MANAGER_RUNNING_AS_MAX] = {
2255         [MANAGER_INIT] = "init",
2256         [MANAGER_SYSTEM] = "system",
2257         [MANAGER_SESSION] = "session"
2258 };
2259
2260 DEFINE_STRING_TABLE_LOOKUP(manager_running_as, ManagerRunningAs);