src/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 <termios.h>
  36 #include <fcntl.h>
  37 #include <sys/types.h>
  38 #include <sys/stat.h>
  39 #include <dirent.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 #include "missing.h"
  55 #include "path-lookup.h"
  56 #include "special.h"
  57 #include "bus-errors.h"
  58
  59 /* As soon as 16 units are in our GC queue, make sure to run a gc sweep */
  60 #define GC_QUEUE_ENTRIES_MAX 16
  61
  62 /* As soon as 5s passed since a unit was added to our GC queue, make sure to run a gc sweep */
  63 #define GC_QUEUE_USEC_MAX (10*USEC_PER_SEC)
  64
  65 /* Where clients shall send notification messages to */
  66 #define NOTIFY_SOCKET "/org/freedesktop/systemd1/notify"
  67
  68 static int manager_setup_notify(Manager *m) {
  69         union {
  70                 struct sockaddr sa;
  71                 struct sockaddr_un un;
  72         } sa;
  73         struct epoll_event ev;
  74         int one = 1;
  75
  76         assert(m);
  77
  78         m->notify_watch.type = WATCH_NOTIFY;
  79         if ((m->notify_watch.fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0)) < 0) {
  80                 log_error("Failed to allocate notification socket: %m");
  81                 return -errno;
  82         }
  83
  84         zero(sa);
  85         sa.sa.sa_family = AF_UNIX;
  86
  87         if (getpid() != 1)
  88                 snprintf(sa.un.sun_path+1, sizeof(sa.un.sun_path)-1, NOTIFY_SOCKET "/%llu", random_ull());
  89         else
  90                 strncpy(sa.un.sun_path+1, NOTIFY_SOCKET, sizeof(sa.un.sun_path)-1);
  91
  92         if (bind(m->notify_watch.fd, &sa.sa, sizeof(sa)) < 0) {
  93                 log_error("bind() failed: %m");
  94                 return -errno;
  95         }
  96
  97         if (setsockopt(m->notify_watch.fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)) < 0) {
  98                 log_error("SO_PASSCRED failed: %m");
  99                 return -errno;
 100         }
 101
 102         zero(ev);
 103         ev.events = EPOLLIN;
 104         ev.data.ptr = &m->notify_watch;
 105
 106         if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->notify_watch.fd, &ev) < 0)
 107                 return -errno;
 108
 109         if (!(m->notify_socket = strdup(sa.un.sun_path+1)))
 110                 return -ENOMEM;
 111
 112         return 0;
 113 }
 114
 115 static int enable_special_signals(Manager *m) {
 116         char fd;
 117
 118         assert(m);
 119
 120         /* Enable that we get SIGINT on control-alt-del */
 121         if (reboot(RB_DISABLE_CAD) < 0)
 122                 log_warning("Failed to enable ctrl-alt-del handling: %m");
 123
 124         if ((fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY)) < 0)
 125                 log_warning("Failed to open /dev/tty0: %m");
 126         else {
 127                 /* Enable that we get SIGWINCH on kbrequest */
 128                 if (ioctl(fd, KDSIGACCEPT, SIGWINCH) < 0)
 129                         log_warning("Failed to enable kbrequest handling: %s", strerror(errno));
 130
 131                 close_nointr_nofail(fd);
 132         }
 133
 134         return 0;
 135 }
 136
 137 static int manager_setup_signals(Manager *m) {
 138         sigset_t mask;
 139         struct epoll_event ev;
 140         struct sigaction sa;
 141
 142         assert(m);
 143
 144         /* We are not interested in SIGSTOP and friends. */
 145         zero(sa);
 146         sa.sa_handler = SIG_DFL;
 147         sa.sa_flags = SA_NOCLDSTOP|SA_RESTART;
 148         assert_se(sigaction(SIGCHLD, &sa, NULL) == 0);
 149
 150         assert_se(sigemptyset(&mask) == 0);
 151
 152         sigset_add_many(&mask,
 153                         SIGCHLD,     /* Child died */
 154                         SIGTERM,     /* Reexecute daemon */
 155                         SIGHUP,      /* Reload configuration */
 156                         SIGUSR1,     /* systemd/upstart: reconnect to D-Bus */
 157                         SIGUSR2,     /* systemd: dump status */
 158                         SIGINT,      /* Kernel sends us this on control-alt-del */
 159                         SIGWINCH,    /* Kernel sends us this on kbrequest (alt-arrowup) */
 160                         SIGPWR,      /* Some kernel drivers and upsd send us this on power failure */
 161                         SIGRTMIN+0,  /* systemd: start default.target */
 162                         SIGRTMIN+1,  /* systemd: start rescue.target */
 163                         SIGRTMIN+2,  /* systemd: isolate emergency.target */
 164                         SIGRTMIN+3,  /* systemd: start halt.target */
 165                         SIGRTMIN+4,  /* systemd: start poweroff.target */
 166                         SIGRTMIN+5,  /* systemd: start reboot.target */
 167                         -1);
 168         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
 169
 170         m->signal_watch.type = WATCH_SIGNAL;
 171         if ((m->signal_watch.fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
 172                 return -errno;
 173
 174         zero(ev);
 175         ev.events = EPOLLIN;
 176         ev.data.ptr = &m->signal_watch;
 177
 178         if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_watch.fd, &ev) < 0)
 179                 return -errno;
 180
 181         if (m->running_as == MANAGER_SYSTEM)
 182                 return enable_special_signals(m);
 183
 184         return 0;
 185 }
 186
 187 int manager_new(ManagerRunningAs running_as, Manager **_m) {
 188         Manager *m;
 189         int r = -ENOMEM;
 190
 191         assert(_m);
 192         assert(running_as >= 0);
 193         assert(running_as < _MANAGER_RUNNING_AS_MAX);
 194
 195         if (!(m = new0(Manager, 1)))
 196                 return -ENOMEM;
 197
 198         dual_timestamp_get(&m->startup_timestamp);
 199
 200         m->running_as = running_as;
 201         m->name_data_slot = m->subscribed_data_slot = -1;
 202         m->exit_code = _MANAGER_EXIT_CODE_INVALID;
 203         m->pin_cgroupfs_fd = -1;
 204
 205         m->signal_watch.fd = m->mount_watch.fd = m->udev_watch.fd = m->epoll_fd = m->dev_autofs_fd = -1;
 206         m->current_job_id = 1; /* start as id #1, so that we can leave #0 around as "null-like" value */
 207
 208         if (!(m->environment = strv_copy(environ)))
 209                 goto fail;
 210
 211         if (!(m->units = hashmap_new(string_hash_func, string_compare_func)))
 212                 goto fail;
 213
 214         if (!(m->jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
 215                 goto fail;
 216
 217         if (!(m->transaction_jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
 218                 goto fail;
 219
 220         if (!(m->watch_pids = hashmap_new(trivial_hash_func, trivial_compare_func)))
 221                 goto fail;
 222
 223         if (!(m->cgroup_bondings = hashmap_new(string_hash_func, string_compare_func)))
 224                 goto fail;
 225
 226         if (!(m->watch_bus = hashmap_new(string_hash_func, string_compare_func)))
 227                 goto fail;
 228
 229         if ((m->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0)
 230                 goto fail;
 231
 232         if ((r = lookup_paths_init(&m->lookup_paths, m->running_as)) < 0)
 233                 goto fail;
 234
 235         if ((r = manager_setup_signals(m)) < 0)
 236                 goto fail;
 237
 238         if ((r = manager_setup_cgroup(m)) < 0)
 239                 goto fail;
 240
 241         if ((r = manager_setup_notify(m)) < 0)
 242                 goto fail;
 243
 244         /* Try to connect to the busses, if possible. */
 245         if ((r = bus_init(m)) < 0)
 246                 goto fail;
 247
 248         *_m = m;
 249         return 0;
 250
 251 fail:
 252         manager_free(m);
 253         return r;
 254 }
 255
 256 static unsigned manager_dispatch_cleanup_queue(Manager *m) {
 257         Meta *meta;
 258         unsigned n = 0;
 259
 260         assert(m);
 261
 262         while ((meta = m->cleanup_queue)) {
 263                 assert(meta->in_cleanup_queue);
 264
 265                 unit_free((Unit*) meta);
 266                 n++;
 267         }
 268
 269         return n;
 270 }
 271
 272 enum {
 273         GC_OFFSET_IN_PATH,  /* This one is on the path we were travelling */
 274         GC_OFFSET_UNSURE,   /* No clue */
 275         GC_OFFSET_GOOD,     /* We still need this unit */
 276         GC_OFFSET_BAD,      /* We don't need this unit anymore */
 277         _GC_OFFSET_MAX
 278 };
 279
 280 static void unit_gc_sweep(Unit *u, unsigned gc_marker) {
 281         Iterator i;
 282         Unit *other;
 283         bool is_bad;
 284
 285         assert(u);
 286
 287         if (u->meta.gc_marker == gc_marker + GC_OFFSET_GOOD ||
 288             u->meta.gc_marker == gc_marker + GC_OFFSET_BAD ||
 289             u->meta.gc_marker == gc_marker + GC_OFFSET_IN_PATH)
 290                 return;
 291
 292         if (u->meta.in_cleanup_queue)
 293                 goto bad;
 294
 295         if (unit_check_gc(u))
 296                 goto good;
 297
 298         u->meta.gc_marker = gc_marker + GC_OFFSET_IN_PATH;
 299
 300         is_bad = true;
 301
 302         SET_FOREACH(other, u->meta.dependencies[UNIT_REFERENCED_BY], i) {
 303                 unit_gc_sweep(other, gc_marker);
 304
 305                 if (other->meta.gc_marker == gc_marker + GC_OFFSET_GOOD)
 306                         goto good;
 307
 308                 if (other->meta.gc_marker != gc_marker + GC_OFFSET_BAD)
 309                         is_bad = false;
 310         }
 311
 312         if (is_bad)
 313                 goto bad;
 314
 315         /* We were unable to find anything out about this entry, so
 316          * let's investigate it later */
 317         u->meta.gc_marker = gc_marker + GC_OFFSET_UNSURE;
 318         unit_add_to_gc_queue(u);
 319         return;
 320
 321 bad:
 322         /* We definitely know that this one is not useful anymore, so
 323          * let's mark it for deletion */
 324         u->meta.gc_marker = gc_marker + GC_OFFSET_BAD;
 325         unit_add_to_cleanup_queue(u);
 326         return;
 327
 328 good:
 329         u->meta.gc_marker = gc_marker + GC_OFFSET_GOOD;
 330 }
 331
 332 static unsigned manager_dispatch_gc_queue(Manager *m) {
 333         Meta *meta;
 334         unsigned n = 0;
 335         unsigned gc_marker;
 336
 337         assert(m);
 338
 339         if ((m->n_in_gc_queue < GC_QUEUE_ENTRIES_MAX) &&
 340             (m->gc_queue_timestamp <= 0 ||
 341              (m->gc_queue_timestamp + GC_QUEUE_USEC_MAX) > now(CLOCK_MONOTONIC)))
 342                 return 0;
 343
 344         log_debug("Running GC...");
 345
 346         m->gc_marker += _GC_OFFSET_MAX;
 347         if (m->gc_marker + _GC_OFFSET_MAX <= _GC_OFFSET_MAX)
 348                 m->gc_marker = 1;
 349
 350         gc_marker = m->gc_marker;
 351
 352         while ((meta = m->gc_queue)) {
 353                 assert(meta->in_gc_queue);
 354
 355                 unit_gc_sweep((Unit*) meta, gc_marker);
 356
 357                 LIST_REMOVE(Meta, gc_queue, m->gc_queue, meta);
 358                 meta->in_gc_queue = false;
 359
 360                 n++;
 361
 362                 if (meta->gc_marker == gc_marker + GC_OFFSET_BAD ||
 363                     meta->gc_marker == gc_marker + GC_OFFSET_UNSURE) {
 364                         log_debug("Collecting %s", meta->id);
 365                         meta->gc_marker = gc_marker + GC_OFFSET_BAD;
 366                         unit_add_to_cleanup_queue((Unit*) meta);
 367                 }
 368         }
 369
 370         m->n_in_gc_queue = 0;
 371         m->gc_queue_timestamp = 0;
 372
 373         return n;
 374 }
 375
 376 static void manager_clear_jobs_and_units(Manager *m) {
 377         Job *j;
 378         Unit *u;
 379
 380         assert(m);
 381
 382         while ((j = hashmap_first(m->transaction_jobs)))
 383                 job_free(j);
 384
 385         while ((u = hashmap_first(m->units)))
 386                 unit_free(u);
 387
 388         manager_dispatch_cleanup_queue(m);
 389
 390         assert(!m->load_queue);
 391         assert(!m->run_queue);
 392         assert(!m->dbus_unit_queue);
 393         assert(!m->dbus_job_queue);
 394         assert(!m->cleanup_queue);
 395         assert(!m->gc_queue);
 396
 397         assert(hashmap_isempty(m->transaction_jobs));
 398         assert(hashmap_isempty(m->jobs));
 399         assert(hashmap_isempty(m->units));
 400 }
 401
 402 void manager_free(Manager *m) {
 403         UnitType c;
 404
 405         assert(m);
 406
 407         manager_clear_jobs_and_units(m);
 408
 409         for (c = 0; c < _UNIT_TYPE_MAX; c++)
 410                 if (unit_vtable[c]->shutdown)
 411                         unit_vtable[c]->shutdown(m);
 412
 413         /* If we reexecute ourselves, we keep the root cgroup
 414          * around */
 415         manager_shutdown_cgroup(m, m->exit_code != MANAGER_REEXECUTE);
 416
 417         bus_done(m);
 418
 419         hashmap_free(m->units);
 420         hashmap_free(m->jobs);
 421         hashmap_free(m->transaction_jobs);
 422         hashmap_free(m->watch_pids);
 423         hashmap_free(m->watch_bus);
 424
 425         if (m->epoll_fd >= 0)
 426                 close_nointr_nofail(m->epoll_fd);
 427         if (m->signal_watch.fd >= 0)
 428                 close_nointr_nofail(m->signal_watch.fd);
 429         if (m->notify_watch.fd >= 0)
 430                 close_nointr_nofail(m->notify_watch.fd);
 431
 432         free(m->notify_socket);
 433
 434         lookup_paths_free(&m->lookup_paths);
 435         strv_free(m->environment);
 436
 437         hashmap_free(m->cgroup_bondings);
 438         set_free_free(m->unit_path_cache);
 439
 440         free(m);
 441 }
 442
 443 int manager_enumerate(Manager *m) {
 444         int r = 0, q;
 445         UnitType c;
 446
 447         assert(m);
 448
 449         /* Let's ask every type to load all units from disk/kernel
 450          * that it might know */
 451         for (c = 0; c < _UNIT_TYPE_MAX; c++)
 452                 if (unit_vtable[c]->enumerate)
 453                         if ((q = unit_vtable[c]->enumerate(m)) < 0)
 454                                 r = q;
 455
 456         manager_dispatch_load_queue(m);
 457         return r;
 458 }
 459
 460 int manager_coldplug(Manager *m) {
 461         int r = 0, q;
 462         Iterator i;
 463         Unit *u;
 464         char *k;
 465
 466         assert(m);
 467
 468         /* Then, let's set up their initial state. */
 469         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
 470
 471                 /* ignore aliases */
 472                 if (u->meta.id != k)
 473                         continue;
 474
 475                 if ((q = unit_coldplug(u)) < 0)
 476                         r = q;
 477         }
 478
 479         return r;
 480 }
 481
 482 static void manager_build_unit_path_cache(Manager *m) {
 483         char **i;
 484         DIR *d = NULL;
 485         int r;
 486
 487         assert(m);
 488
 489         set_free_free(m->unit_path_cache);
 490
 491         if (!(m->unit_path_cache = set_new(string_hash_func, string_compare_func))) {
 492                 log_error("Failed to allocate unit path cache.");
 493                 return;
 494         }
 495
 496         /* This simply builds a list of files we know exist, so that
 497          * we don't always have to go to disk */
 498
 499         STRV_FOREACH(i, m->lookup_paths.unit_path) {
 500                 struct dirent *de;
 501
 502                 if (!(d = opendir(*i))) {
 503                         log_error("Failed to open directory: %m");
 504                         continue;
 505                 }
 506
 507                 while ((de = readdir(d))) {
 508                         char *p;
 509
 510                         if (ignore_file(de->d_name))
 511                                 continue;
 512
 513                         if (asprintf(&p, "%s/%s", streq(*i, "/") ? "" : *i, de->d_name) < 0) {
 514                                 r = -ENOMEM;
 515                                 goto fail;
 516                         }
 517
 518                         if ((r = set_put(m->unit_path_cache, p)) < 0) {
 519                                 free(p);
 520                                 goto fail;
 521                         }
 522                 }
 523
 524                 closedir(d);
 525                 d = NULL;
 526         }
 527
 528         return;
 529
 530 fail:
 531         log_error("Failed to build unit path cache: %s", strerror(-r));
 532
 533         set_free_free(m->unit_path_cache);
 534         m->unit_path_cache = NULL;
 535
 536         if (d)
 537                 closedir(d);
 538 }
 539
 540 int manager_startup(Manager *m, FILE *serialization, FDSet *fds) {
 541         int r, q;
 542
 543         assert(m);
 544
 545         manager_build_unit_path_cache(m);
 546
 547         /* First, enumerate what we can from all config files */
 548         r = manager_enumerate(m);
 549
 550         /* Second, deserialize if there is something to deserialize */
 551         if (serialization)
 552                 if ((q = manager_deserialize(m, serialization, fds)) < 0)
 553                         r = q;
 554
 555         /* Third, fire things up! */
 556         if ((q = manager_coldplug(m)) < 0)
 557                 r = q;
 558
 559         /* Now that the initial devices are available, let's see if we
 560          * can write the utmp file */
 561         manager_write_utmp_reboot(m);
 562
 563         return r;
 564 }
 565
 566 static void transaction_delete_job(Manager *m, Job *j, bool delete_dependencies) {
 567         assert(m);
 568         assert(j);
 569
 570         /* Deletes one job from the transaction */
 571
 572         manager_transaction_unlink_job(m, j, delete_dependencies);
 573
 574         if (!j->installed)
 575                 job_free(j);
 576 }
 577
 578 static void transaction_delete_unit(Manager *m, Unit *u) {
 579         Job *j;
 580
 581         /* Deletes all jobs associated with a certain unit from the
 582          * transaction */
 583
 584         while ((j = hashmap_get(m->transaction_jobs, u)))
 585                 transaction_delete_job(m, j, true);
 586 }
 587
 588 static void transaction_clean_dependencies(Manager *m) {
 589         Iterator i;
 590         Job *j;
 591
 592         assert(m);
 593
 594         /* Drops all dependencies of all installed jobs */
 595
 596         HASHMAP_FOREACH(j, m->jobs, i) {
 597                 while (j->subject_list)
 598                         job_dependency_free(j->subject_list);
 599                 while (j->object_list)
 600                         job_dependency_free(j->object_list);
 601         }
 602
 603         assert(!m->transaction_anchor);
 604 }
 605
 606 static void transaction_abort(Manager *m) {
 607         Job *j;
 608
 609         assert(m);
 610
 611         while ((j = hashmap_first(m->transaction_jobs)))
 612                 if (j->installed)
 613                         transaction_delete_job(m, j, true);
 614                 else
 615                         job_free(j);
 616
 617         assert(hashmap_isempty(m->transaction_jobs));
 618
 619         transaction_clean_dependencies(m);
 620 }
 621
 622 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
 623         JobDependency *l;
 624
 625         assert(m);
 626
 627         /* A recursive sweep through the graph that marks all units
 628          * that matter to the anchor job, i.e. are directly or
 629          * indirectly a dependency of the anchor job via paths that
 630          * are fully marked as mattering. */
 631
 632         if (j)
 633                 l = j->subject_list;
 634         else
 635                 l = m->transaction_anchor;
 636
 637         LIST_FOREACH(subject, l, l) {
 638
 639                 /* This link does not matter */
 640                 if (!l->matters)
 641                         continue;
 642
 643                 /* This unit has already been marked */
 644                 if (l->object->generation == generation)
 645                         continue;
 646
 647                 l->object->matters_to_anchor = true;
 648                 l->object->generation = generation;
 649
 650                 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
 651         }
 652 }
 653
 654 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
 655         JobDependency *l, *last;
 656
 657         assert(j);
 658         assert(other);
 659         assert(j->unit == other->unit);
 660         assert(!j->installed);
 661
 662         /* Merges 'other' into 'j' and then deletes j. */
 663
 664         j->type = t;
 665         j->state = JOB_WAITING;
 666         j->override = j->override || other->override;
 667
 668         j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
 669
 670         /* Patch us in as new owner of the JobDependency objects */
 671         last = NULL;
 672         LIST_FOREACH(subject, l, other->subject_list) {
 673                 assert(l->subject == other);
 674                 l->subject = j;
 675                 last = l;
 676         }
 677
 678         /* Merge both lists */
 679         if (last) {
 680                 last->subject_next = j->subject_list;
 681                 if (j->subject_list)
 682                         j->subject_list->subject_prev = last;
 683                 j->subject_list = other->subject_list;
 684         }
 685
 686         /* Patch us in as new owner of the JobDependency objects */
 687         last = NULL;
 688         LIST_FOREACH(object, l, other->object_list) {
 689                 assert(l->object == other);
 690                 l->object = j;
 691                 last = l;
 692         }
 693
 694         /* Merge both lists */
 695         if (last) {
 696                 last->object_next = j->object_list;
 697                 if (j->object_list)
 698                         j->object_list->object_prev = last;
 699                 j->object_list = other->object_list;
 700         }
 701
 702         /* Kill the other job */
 703         other->subject_list = NULL;
 704         other->object_list = NULL;
 705         transaction_delete_job(m, other, true);
 706 }
 707
 708 static int delete_one_unmergeable_job(Manager *m, Job *j) {
 709         Job *k;
 710
 711         assert(j);
 712
 713         /* Tries to delete one item in the linked list
 714          * j->transaction_next->transaction_next->... that conflicts
 715          * whith another one, in an attempt to make an inconsistent
 716          * transaction work. */
 717
 718         /* We rely here on the fact that if a merged with b does not
 719          * merge with c, either a or b merge with c neither */
 720         LIST_FOREACH(transaction, j, j)
 721                 LIST_FOREACH(transaction, k, j->transaction_next) {
 722                         Job *d;
 723
 724                         /* Is this one mergeable? Then skip it */
 725                         if (job_type_is_mergeable(j->type, k->type))
 726                                 continue;
 727
 728                         /* Ok, we found two that conflict, let's see if we can
 729                          * drop one of them */
 730                         if (!j->matters_to_anchor)
 731                                 d = j;
 732                         else if (!k->matters_to_anchor)
 733                                 d = k;
 734                         else
 735                                 return -ENOEXEC;
 736
 737                         /* Ok, we can drop one, so let's do so. */
 738                         log_notice("Trying to fix job merging by deleting job %s/%s", d->unit->meta.id, job_type_to_string(d->type));
 739                         transaction_delete_job(m, d, true);
 740                         return 0;
 741                 }
 742
 743         return -EINVAL;
 744 }
 745
 746 static int transaction_merge_jobs(Manager *m, DBusError *e) {
 747         Job *j;
 748         Iterator i;
 749         int r;
 750
 751         assert(m);
 752
 753         /* First step, check whether any of the jobs for one specific
 754          * task conflict. If so, try to drop one of them. */
 755         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 756                 JobType t;
 757                 Job *k;
 758
 759                 t = j->type;
 760                 LIST_FOREACH(transaction, k, j->transaction_next) {
 761                         if ((r = job_type_merge(&t, k->type)) >= 0)
 762                                 continue;
 763
 764                         /* OK, we could not merge all jobs for this
 765                          * action. Let's see if we can get rid of one
 766                          * of them */
 767
 768                         if ((r = delete_one_unmergeable_job(m, j)) >= 0)
 769                                 /* Ok, we managed to drop one, now
 770                                  * let's ask our callers to call us
 771                                  * again after garbage collecting */
 772                                 return -EAGAIN;
 773
 774                         /* We couldn't merge anything. Failure */
 775                         dbus_set_error(e, BUS_ERROR_TRANSACTION_JOBS_CONFLICTING, "Transaction contains conflicting jobs '%s' and '%s' for %s. Probably contradicting requirement dependencies configured.",
 776                                        job_type_to_string(t), job_type_to_string(k->type), k->unit->meta.id);
 777                         return r;
 778                 }
 779         }
 780
 781         /* Second step, merge the jobs. */
 782         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 783                 JobType t = j->type;
 784                 Job *k;
 785
 786                 /* Merge all transactions */
 787                 LIST_FOREACH(transaction, k, j->transaction_next)
 788                         assert_se(job_type_merge(&t, k->type) == 0);
 789
 790                 /* If an active job is mergeable, merge it too */
 791                 if (j->unit->meta.job)
 792                         job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
 793
 794                 while ((k = j->transaction_next)) {
 795                         if (j->installed) {
 796                                 transaction_merge_and_delete_job(m, k, j, t);
 797                                 j = k;
 798                         } else
 799                                 transaction_merge_and_delete_job(m, j, k, t);
 800                 }
 801
 802                 assert(!j->transaction_next);
 803                 assert(!j->transaction_prev);
 804         }
 805
 806         return 0;
 807 }
 808
 809 static void transaction_drop_redundant(Manager *m) {
 810         bool again;
 811
 812         assert(m);
 813
 814         /* Goes through the transaction and removes all jobs that are
 815          * a noop */
 816
 817         do {
 818                 Job *j;
 819                 Iterator i;
 820
 821                 again = false;
 822
 823                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 824                         bool changes_something = false;
 825                         Job *k;
 826
 827                         LIST_FOREACH(transaction, k, j) {
 828
 829                                 if (!job_is_anchor(k) &&
 830                                     job_type_is_redundant(k->type, unit_active_state(k->unit)))
 831                                         continue;
 832
 833                                 changes_something = true;
 834                                 break;
 835                         }
 836
 837                         if (changes_something)
 838                                 continue;
 839
 840                         log_debug("Found redundant job %s/%s, dropping.", j->unit->meta.id, job_type_to_string(j->type));
 841                         transaction_delete_job(m, j, false);
 842                         again = true;
 843                         break;
 844                 }
 845
 846         } while (again);
 847 }
 848
 849 static bool unit_matters_to_anchor(Unit *u, Job *j) {
 850         assert(u);
 851         assert(!j->transaction_prev);
 852
 853         /* Checks whether at least one of the jobs for this unit
 854          * matters to the anchor. */
 855
 856         LIST_FOREACH(transaction, j, j)
 857                 if (j->matters_to_anchor)
 858                         return true;
 859
 860         return false;
 861 }
 862
 863 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation, DBusError *e) {
 864         Iterator i;
 865         Unit *u;
 866         int r;
 867
 868         assert(m);
 869         assert(j);
 870         assert(!j->transaction_prev);
 871
 872         /* Does a recursive sweep through the ordering graph, looking
 873          * for a cycle. If we find cycle we try to break it. */
 874
 875         /* Have we seen this before? */
 876         if (j->generation == generation) {
 877                 Job *k;
 878
 879                 /* If the marker is NULL we have been here already and
 880                  * decided the job was loop-free from here. Hence
 881                  * shortcut things and return right-away. */
 882                 if (!j->marker)
 883                         return 0;
 884
 885                 /* So, the marker is not NULL and we already have been
 886                  * here. We have a cycle. Let's try to break it. We go
 887                  * backwards in our path and try to find a suitable
 888                  * job to remove. We use the marker to find our way
 889                  * back, since smart how we are we stored our way back
 890                  * in there. */
 891                 log_warning("Found ordering cycle on %s/%s", j->unit->meta.id, job_type_to_string(j->type));
 892
 893                 for (k = from; k; k = ((k->generation == generation && k->marker != k) ? k->marker : NULL)) {
 894
 895                         log_info("Walked on cycle path to %s/%s", k->unit->meta.id, job_type_to_string(k->type));
 896
 897                         if (!k->installed &&
 898                             !unit_matters_to_anchor(k->unit, k)) {
 899                                 /* Ok, we can drop this one, so let's
 900                                  * do so. */
 901                                 log_warning("Breaking order cycle by deleting job %s/%s", k->unit->meta.id, job_type_to_string(k->type));
 902                                 transaction_delete_unit(m, k->unit);
 903                                 return -EAGAIN;
 904                         }
 905
 906                         /* Check if this in fact was the beginning of
 907                          * the cycle */
 908                         if (k == j)
 909                                 break;
 910                 }
 911
 912                 log_error("Unable to break cycle");
 913
 914                 dbus_set_error(e, BUS_ERROR_TRANSACTION_ORDER_IS_CYCLIC, "Transaction order is cyclic. See logs for details.");
 915                 return -ENOEXEC;
 916         }
 917
 918         /* Make the marker point to where we come from, so that we can
 919          * find our way backwards if we want to break a cycle. We use
 920          * a special marker for the beginning: we point to
 921          * ourselves. */
 922         j->marker = from ? from : j;
 923         j->generation = generation;
 924
 925         /* We assume that the the dependencies are bidirectional, and
 926          * hence can ignore UNIT_AFTER */
 927         SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
 928                 Job *o;
 929
 930                 /* Is there a job for this unit? */
 931                 if (!(o = hashmap_get(m->transaction_jobs, u)))
 932
 933                         /* Ok, there is no job for this in the
 934                          * transaction, but maybe there is already one
 935                          * running? */
 936                         if (!(o = u->meta.job))
 937                                 continue;
 938
 939                 if ((r = transaction_verify_order_one(m, o, j, generation, e)) < 0)
 940                         return r;
 941         }
 942
 943         /* Ok, let's backtrack, and remember that this entry is not on
 944          * our path anymore. */
 945         j->marker = NULL;
 946
 947         return 0;
 948 }
 949
 950 static int transaction_verify_order(Manager *m, unsigned *generation, DBusError *e) {
 951         Job *j;
 952         int r;
 953         Iterator i;
 954         unsigned g;
 955
 956         assert(m);
 957         assert(generation);
 958
 959         /* Check if the ordering graph is cyclic. If it is, try to fix
 960          * that up by dropping one of the jobs. */
 961
 962         g = (*generation)++;
 963
 964         HASHMAP_FOREACH(j, m->transaction_jobs, i)
 965                 if ((r = transaction_verify_order_one(m, j, NULL, g, e)) < 0)
 966                         return r;
 967
 968         return 0;
 969 }
 970
 971 static void transaction_collect_garbage(Manager *m) {
 972         bool again;
 973
 974         assert(m);
 975
 976         /* Drop jobs that are not required by any other job */
 977
 978         do {
 979                 Iterator i;
 980                 Job *j;
 981
 982                 again = false;
 983
 984                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 985                         if (j->object_list)
 986                                 continue;
 987
 988                         log_debug("Garbage collecting job %s/%s", j->unit->meta.id, job_type_to_string(j->type));
 989                         transaction_delete_job(m, j, true);
 990                         again = true;
 991                         break;
 992                 }
 993
 994         } while (again);
 995 }
 996
 997 static int transaction_is_destructive(Manager *m, DBusError *e) {
 998         Iterator i;
 999         Job *j;
1000
1001         assert(m);
1002
1003         /* Checks whether applying this transaction means that
1004          * existing jobs would be replaced */
1005
1006         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1007
1008                 /* Assume merged */
1009                 assert(!j->transaction_prev);
1010                 assert(!j->transaction_next);
1011
1012                 if (j->unit->meta.job &&
1013                     j->unit->meta.job != j &&
1014                     !job_type_is_superset(j->type, j->unit->meta.job->type)) {
1015
1016                         dbus_set_error(e, BUS_ERROR_TRANSACTION_IS_DESTRUCTIVE, "Transaction is destructive.");
1017                         return -EEXIST;
1018                 }
1019         }
1020
1021         return 0;
1022 }
1023
1024 static void transaction_minimize_impact(Manager *m) {
1025         bool again;
1026         assert(m);
1027
1028         /* Drops all unnecessary jobs that reverse already active jobs
1029          * or that stop a running service. */
1030
1031         do {
1032                 Job *j;
1033                 Iterator i;
1034
1035                 again = false;
1036
1037                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1038                         LIST_FOREACH(transaction, j, j) {
1039                                 bool stops_running_service, changes_existing_job;
1040
1041                                 /* If it matters, we shouldn't drop it */
1042                                 if (j->matters_to_anchor)
1043                                         continue;
1044
1045                                 /* Would this stop a running service?
1046                                  * Would this change an existing job?
1047                                  * If so, let's drop this entry */
1048
1049                                 stops_running_service =
1050                                         j->type == JOB_STOP && UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(j->unit));
1051
1052                                 changes_existing_job =
1053                                         j->unit->meta.job && job_type_is_conflicting(j->type, j->unit->meta.job->state);
1054
1055                                 if (!stops_running_service && !changes_existing_job)
1056                                         continue;
1057
1058                                 if (stops_running_service)
1059                                         log_info("%s/%s would stop a running service.", j->unit->meta.id, job_type_to_string(j->type));
1060
1061                                 if (changes_existing_job)
1062                                         log_info("%s/%s would change existing job.", j->unit->meta.id, job_type_to_string(j->type));
1063
1064                                 /* Ok, let's get rid of this */
1065                                 log_info("Deleting %s/%s to minimize impact.", j->unit->meta.id, job_type_to_string(j->type));
1066
1067                                 transaction_delete_job(m, j, true);
1068                                 again = true;
1069                                 break;
1070                         }
1071
1072                         if (again)
1073                                 break;
1074                 }
1075
1076         } while (again);
1077 }
1078
1079 static int transaction_apply(Manager *m) {
1080         Iterator i;
1081         Job *j;
1082         int r;
1083
1084         /* Moves the transaction jobs to the set of active jobs */
1085
1086         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1087                 /* Assume merged */
1088                 assert(!j->transaction_prev);
1089                 assert(!j->transaction_next);
1090
1091                 if (j->installed)
1092                         continue;
1093
1094                 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
1095                         goto rollback;
1096         }
1097
1098         while ((j = hashmap_steal_first(m->transaction_jobs))) {
1099                 if (j->installed)
1100                         continue;
1101
1102                 if (j->unit->meta.job)
1103                         job_free(j->unit->meta.job);
1104
1105                 j->unit->meta.job = j;
1106                 j->installed = true;
1107
1108                 /* We're fully installed. Now let's free data we don't
1109                  * need anymore. */
1110
1111                 assert(!j->transaction_next);
1112                 assert(!j->transaction_prev);
1113
1114                 job_add_to_run_queue(j);
1115                 job_add_to_dbus_queue(j);
1116         }
1117
1118         /* As last step, kill all remaining job dependencies. */
1119         transaction_clean_dependencies(m);
1120
1121         return 0;
1122
1123 rollback:
1124
1125         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1126                 if (j->installed)
1127                         continue;
1128
1129                 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
1130         }
1131
1132         return r;
1133 }
1134
1135 static int transaction_activate(Manager *m, JobMode mode, DBusError *e) {
1136         int r;
1137         unsigned generation = 1;
1138
1139         assert(m);
1140
1141         /* This applies the changes recorded in transaction_jobs to
1142          * the actual list of jobs, if possible. */
1143
1144         /* First step: figure out which jobs matter */
1145         transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
1146
1147         /* Second step: Try not to stop any running services if
1148          * we don't have to. Don't try to reverse running
1149          * jobs if we don't have to. */
1150         transaction_minimize_impact(m);
1151
1152         /* Third step: Drop redundant jobs */
1153         transaction_drop_redundant(m);
1154
1155         for (;;) {
1156                 /* Fourth step: Let's remove unneeded jobs that might
1157                  * be lurking. */
1158                 transaction_collect_garbage(m);
1159
1160                 /* Fifth step: verify order makes sense and correct
1161                  * cycles if necessary and possible */
1162                 if ((r = transaction_verify_order(m, &generation, e)) >= 0)
1163                         break;
1164
1165                 if (r != -EAGAIN) {
1166                         log_warning("Requested transaction contains an unfixable cyclic ordering dependency: %s", bus_error(e, r));
1167                         goto rollback;
1168                 }
1169
1170                 /* Let's see if the resulting transaction ordering
1171                  * graph is still cyclic... */
1172         }
1173
1174         for (;;) {
1175                 /* Sixth step: let's drop unmergeable entries if
1176                  * necessary and possible, merge entries we can
1177                  * merge */
1178                 if ((r = transaction_merge_jobs(m, e)) >= 0)
1179                         break;
1180
1181                 if (r != -EAGAIN) {
1182                         log_warning("Requested transaction contains unmergable jobs: %s", bus_error(e, r));
1183                         goto rollback;
1184                 }
1185
1186                 /* Seventh step: an entry got dropped, let's garbage
1187                  * collect its dependencies. */
1188                 transaction_collect_garbage(m);
1189
1190                 /* Let's see if the resulting transaction still has
1191                  * unmergeable entries ... */
1192         }
1193
1194         /* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */
1195         transaction_drop_redundant(m);
1196
1197         /* Ninth step: check whether we can actually apply this */
1198         if (mode == JOB_FAIL)
1199                 if ((r = transaction_is_destructive(m, e)) < 0) {
1200                         log_notice("Requested transaction contradicts existing jobs: %s", bus_error(e, r));
1201                         goto rollback;
1202                 }
1203
1204         /* Tenth step: apply changes */
1205         if ((r = transaction_apply(m)) < 0) {
1206                 log_warning("Failed to apply transaction: %s", strerror(-r));
1207                 goto rollback;
1208         }
1209
1210         assert(hashmap_isempty(m->transaction_jobs));
1211         assert(!m->transaction_anchor);
1212
1213         return 0;
1214
1215 rollback:
1216         transaction_abort(m);
1217         return r;
1218 }
1219
1220 static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool override, bool *is_new) {
1221         Job *j, *f;
1222         int r;
1223
1224         assert(m);
1225         assert(unit);
1226
1227         /* Looks for an axisting prospective job and returns that. If
1228          * it doesn't exist it is created and added to the prospective
1229          * jobs list. */
1230
1231         f = hashmap_get(m->transaction_jobs, unit);
1232
1233         LIST_FOREACH(transaction, j, f) {
1234                 assert(j->unit == unit);
1235
1236                 if (j->type == type) {
1237                         if (is_new)
1238                                 *is_new = false;
1239                         return j;
1240                 }
1241         }
1242
1243         if (unit->meta.job && unit->meta.job->type == type)
1244                 j = unit->meta.job;
1245         else if (!(j = job_new(m, type, unit)))
1246                 return NULL;
1247
1248         j->generation = 0;
1249         j->marker = NULL;
1250         j->matters_to_anchor = false;
1251         j->override = override;
1252
1253         LIST_PREPEND(Job, transaction, f, j);
1254
1255         if ((r = hashmap_replace(m->transaction_jobs, unit, f)) < 0) {
1256                 job_free(j);
1257                 return NULL;
1258         }
1259
1260         if (is_new)
1261                 *is_new = true;
1262
1263         log_debug("Added job %s/%s to transaction.", unit->meta.id, job_type_to_string(type));
1264
1265         return j;
1266 }
1267
1268 void manager_transaction_unlink_job(Manager *m, Job *j, bool delete_dependencies) {
1269         assert(m);
1270         assert(j);
1271
1272         if (j->transaction_prev)
1273                 j->transaction_prev->transaction_next = j->transaction_next;
1274         else if (j->transaction_next)
1275                 hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
1276         else
1277                 hashmap_remove_value(m->transaction_jobs, j->unit, j);
1278
1279         if (j->transaction_next)
1280                 j->transaction_next->transaction_prev = j->transaction_prev;
1281
1282         j->transaction_prev = j->transaction_next = NULL;
1283
1284         while (j->subject_list)
1285                 job_dependency_free(j->subject_list);
1286
1287         while (j->object_list) {
1288                 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
1289
1290                 job_dependency_free(j->object_list);
1291
1292                 if (other && delete_dependencies) {
1293                         log_info("Deleting job %s/%s as dependency of job %s/%s",
1294                                   other->unit->meta.id, job_type_to_string(other->type),
1295                                   j->unit->meta.id, job_type_to_string(j->type));
1296                         transaction_delete_job(m, other, delete_dependencies);
1297                 }
1298         }
1299 }
1300
1301 static int transaction_add_job_and_dependencies(
1302                 Manager *m,
1303                 JobType type,
1304                 Unit *unit,
1305                 Job *by,
1306                 bool matters,
1307                 bool override,
1308                 DBusError *e,
1309                 Job **_ret) {
1310         Job *ret;
1311         Iterator i;
1312         Unit *dep;
1313         int r;
1314         bool is_new;
1315
1316         assert(m);
1317         assert(type < _JOB_TYPE_MAX);
1318         assert(unit);
1319
1320         if (unit->meta.load_state != UNIT_LOADED) {
1321                 dbus_set_error(e, BUS_ERROR_LOAD_FAILED, "Unit %s failed to load. See logs for details.", unit->meta.id);
1322                 return -EINVAL;
1323         }
1324
1325         if (!unit_job_is_applicable(unit, type)) {
1326                 dbus_set_error(e, BUS_ERROR_JOB_TYPE_NOT_APPLICABLE, "Job type %s is not applicable for unit %s.", job_type_to_string(type), unit->meta.id);
1327                 return -EBADR;
1328         }
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, e, 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, e, NULL)) < 0 && r != -EBADR) {
1347                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, bus_error(e, r));
1348                                         dbus_error_free(e);
1349                                 }
1350
1351                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
1352                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, false, e, NULL)) < 0) {
1353                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, bus_error(e, r));
1354                                         dbus_error_free(e);
1355                                 }
1356
1357                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
1358                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, override, e, NULL)) < 0 && r != -EBADR)
1359                                         goto fail;
1360
1361                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE_OVERRIDABLE], i)
1362                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !override, override, e, NULL)) < 0 && r != -EBADR) {
1363                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, bus_error(e, r));
1364                                         dbus_error_free(e);
1365                                 }
1366
1367                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
1368                                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, override, e, NULL)) < 0 && r != -EBADR)
1369                                         goto fail;
1370
1371                 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
1372
1373                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
1374                                 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, override, e, NULL)) < 0 && r != -EBADR)
1375                                         goto fail;
1376                 }
1377
1378                 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
1379         }
1380
1381         if (_ret)
1382                 *_ret = ret;
1383
1384         return 0;
1385
1386 fail:
1387         return r;
1388 }
1389
1390 static int transaction_add_isolate_jobs(Manager *m) {
1391         Iterator i;
1392         Unit *u;
1393         char *k;
1394         int r;
1395
1396         assert(m);
1397
1398         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
1399
1400                 /* ignore aliases */
1401                 if (u->meta.id != k)
1402                         continue;
1403
1404                 if (UNIT_VTABLE(u)->no_isolate)
1405                         continue;
1406
1407                 /* No need to stop inactive jobs */
1408                 if (UNIT_IS_INACTIVE_OR_MAINTENANCE(unit_active_state(u)))
1409                         continue;
1410
1411                 /* Is there already something listed for this? */
1412                 if (hashmap_get(m->transaction_jobs, u))
1413                         continue;
1414
1415                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, u, NULL, true, false, NULL, NULL)) < 0)
1416                         log_warning("Cannot add isolate job for unit %s, ignoring: %s", u->meta.id, strerror(-r));
1417         }
1418
1419         return 0;
1420 }
1421
1422 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool override, DBusError *e, Job **_ret) {
1423         int r;
1424         Job *ret;
1425
1426         assert(m);
1427         assert(type < _JOB_TYPE_MAX);
1428         assert(unit);
1429         assert(mode < _JOB_MODE_MAX);
1430
1431         if (mode == JOB_ISOLATE && type != JOB_START) {
1432                 dbus_set_error(e, BUS_ERROR_INVALID_JOB_MODE, "Isolate is only valid for start.");
1433                 return -EINVAL;
1434         }
1435
1436         log_debug("Trying to enqueue job %s/%s", unit->meta.id, job_type_to_string(type));
1437
1438         if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, override, e, &ret)) < 0) {
1439                 transaction_abort(m);
1440                 return r;
1441         }
1442
1443         if (mode == JOB_ISOLATE)
1444                 if ((r = transaction_add_isolate_jobs(m)) < 0) {
1445                         transaction_abort(m);
1446                         return r;
1447                 }
1448
1449         if ((r = transaction_activate(m, mode, e)) < 0)
1450                 return r;
1451
1452         log_debug("Enqueued job %s/%s as %u", unit->meta.id, job_type_to_string(type), (unsigned) ret->id);
1453
1454         if (_ret)
1455                 *_ret = ret;
1456
1457         return 0;
1458 }
1459
1460 int manager_add_job_by_name(Manager *m, JobType type, const char *name, JobMode mode, bool override, DBusError *e, Job **_ret) {
1461         Unit *unit;
1462         int r;
1463
1464         assert(m);
1465         assert(type < _JOB_TYPE_MAX);
1466         assert(name);
1467         assert(mode < _JOB_MODE_MAX);
1468
1469         if ((r = manager_load_unit(m, name, NULL, NULL, &unit)) < 0)
1470                 return r;
1471
1472         return manager_add_job(m, type, unit, mode, override, e, _ret);
1473 }
1474
1475 Job *manager_get_job(Manager *m, uint32_t id) {
1476         assert(m);
1477
1478         return hashmap_get(m->jobs, UINT32_TO_PTR(id));
1479 }
1480
1481 Unit *manager_get_unit(Manager *m, const char *name) {
1482         assert(m);
1483         assert(name);
1484
1485         return hashmap_get(m->units, name);
1486 }
1487
1488 unsigned manager_dispatch_load_queue(Manager *m) {
1489         Meta *meta;
1490         unsigned n = 0;
1491
1492         assert(m);
1493
1494         /* Make sure we are not run recursively */
1495         if (m->dispatching_load_queue)
1496                 return 0;
1497
1498         m->dispatching_load_queue = true;
1499
1500         /* Dispatches the load queue. Takes a unit from the queue and
1501          * tries to load its data until the queue is empty */
1502
1503         while ((meta = m->load_queue)) {
1504                 assert(meta->in_load_queue);
1505
1506                 unit_load((Unit*) meta);
1507                 n++;
1508         }
1509
1510         m->dispatching_load_queue = false;
1511         return n;
1512 }
1513
1514 int manager_load_unit_prepare(Manager *m, const char *name, const char *path, DBusError *e, Unit **_ret) {
1515         Unit *ret;
1516         int r;
1517
1518         assert(m);
1519         assert(name || path);
1520
1521         /* This will prepare the unit for loading, but not actually
1522          * load anything from disk. */
1523
1524         if (path && !is_path(path)) {
1525                 dbus_set_error(e, BUS_ERROR_INVALID_PATH, "Path %s is not absolute.", path);
1526                 return -EINVAL;
1527         }
1528
1529         if (!name)
1530                 name = file_name_from_path(path);
1531
1532         if (!unit_name_is_valid(name)) {
1533                 dbus_set_error(e, BUS_ERROR_INVALID_NAME, "Unit name %s is not valid.", name);
1534                 return -EINVAL;
1535         }
1536
1537         if ((ret = manager_get_unit(m, name))) {
1538                 *_ret = ret;
1539                 return 1;
1540         }
1541
1542         if (!(ret = unit_new(m)))
1543                 return -ENOMEM;
1544
1545         if (path)
1546                 if (!(ret->meta.fragment_path = strdup(path))) {
1547                         unit_free(ret);
1548                         return -ENOMEM;
1549                 }
1550
1551         if ((r = unit_add_name(ret, name)) < 0) {
1552                 unit_free(ret);
1553                 return r;
1554         }
1555
1556         unit_add_to_load_queue(ret);
1557         unit_add_to_dbus_queue(ret);
1558         unit_add_to_gc_queue(ret);
1559
1560         if (_ret)
1561                 *_ret = ret;
1562
1563         return 0;
1564 }
1565
1566 int manager_load_unit(Manager *m, const char *name, const char *path, DBusError *e, Unit **_ret) {
1567         int r;
1568
1569         assert(m);
1570
1571         /* This will load the service information files, but not actually
1572          * start any services or anything. */
1573
1574         if ((r = manager_load_unit_prepare(m, name, path, e, _ret)) != 0)
1575                 return r;
1576
1577         manager_dispatch_load_queue(m);
1578
1579         if (_ret)
1580                 *_ret = unit_follow_merge(*_ret);
1581
1582         return 0;
1583 }
1584
1585 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
1586         Iterator i;
1587         Job *j;
1588
1589         assert(s);
1590         assert(f);
1591
1592         HASHMAP_FOREACH(j, s->jobs, i)
1593                 job_dump(j, f, prefix);
1594 }
1595
1596 void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
1597         Iterator i;
1598         Unit *u;
1599         const char *t;
1600
1601         assert(s);
1602         assert(f);
1603
1604         HASHMAP_FOREACH_KEY(u, t, s->units, i)
1605                 if (u->meta.id == t)
1606                         unit_dump(u, f, prefix);
1607 }
1608
1609 void manager_clear_jobs(Manager *m) {
1610         Job *j;
1611
1612         assert(m);
1613
1614         transaction_abort(m);
1615
1616         while ((j = hashmap_first(m->jobs)))
1617                 job_free(j);
1618 }
1619
1620 unsigned manager_dispatch_run_queue(Manager *m) {
1621         Job *j;
1622         unsigned n = 0;
1623
1624         if (m->dispatching_run_queue)
1625                 return 0;
1626
1627         m->dispatching_run_queue = true;
1628
1629         while ((j = m->run_queue)) {
1630                 assert(j->installed);
1631                 assert(j->in_run_queue);
1632
1633                 job_run_and_invalidate(j);
1634                 n++;
1635         }
1636
1637         m->dispatching_run_queue = false;
1638         return n;
1639 }
1640
1641 unsigned manager_dispatch_dbus_queue(Manager *m) {
1642         Job *j;
1643         Meta *meta;
1644         unsigned n = 0;
1645
1646         assert(m);
1647
1648         if (m->dispatching_dbus_queue)
1649                 return 0;
1650
1651         m->dispatching_dbus_queue = true;
1652
1653         while ((meta = m->dbus_unit_queue)) {
1654                 assert(meta->in_dbus_queue);
1655
1656                 bus_unit_send_change_signal((Unit*) meta);
1657                 n++;
1658         }
1659
1660         while ((j = m->dbus_job_queue)) {
1661                 assert(j->in_dbus_queue);
1662
1663                 bus_job_send_change_signal(j);
1664                 n++;
1665         }
1666
1667         m->dispatching_dbus_queue = false;
1668         return n;
1669 }
1670
1671 static int manager_process_notify_fd(Manager *m) {
1672         ssize_t n;
1673
1674         assert(m);
1675
1676         for (;;) {
1677                 char buf[4096];
1678                 struct msghdr msghdr;
1679                 struct iovec iovec;
1680                 struct ucred *ucred;
1681                 union {
1682                         struct cmsghdr cmsghdr;
1683                         uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
1684                 } control;
1685                 Unit *u;
1686                 char **tags;
1687
1688                 zero(iovec);
1689                 iovec.iov_base = buf;
1690                 iovec.iov_len = sizeof(buf)-1;
1691
1692                 zero(control);
1693                 zero(msghdr);
1694                 msghdr.msg_iov = &iovec;
1695                 msghdr.msg_iovlen = 1;
1696                 msghdr.msg_control = &control;
1697                 msghdr.msg_controllen = sizeof(control);
1698
1699                 if ((n = recvmsg(m->notify_watch.fd, &msghdr, MSG_DONTWAIT)) <= 0) {
1700                         if (n >= 0)
1701                                 return -EIO;
1702
1703                         if (errno == EAGAIN)
1704                                 break;
1705
1706                         return -errno;
1707                 }
1708
1709                 if (msghdr.msg_controllen < CMSG_LEN(sizeof(struct ucred)) ||
1710                     control.cmsghdr.cmsg_level != SOL_SOCKET ||
1711                     control.cmsghdr.cmsg_type != SCM_CREDENTIALS ||
1712                     control.cmsghdr.cmsg_len != CMSG_LEN(sizeof(struct ucred))) {
1713                         log_warning("Received notify message without credentials. Ignoring.");
1714                         continue;
1715                 }
1716
1717                 ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
1718
1719                 if (!(u = hashmap_get(m->watch_pids, LONG_TO_PTR(ucred->pid))))
1720                         if (!(u = cgroup_unit_by_pid(m, ucred->pid))) {
1721                                 log_warning("Cannot find unit for notify message of PID %lu.", (unsigned long) ucred->pid);
1722                                 continue;
1723                         }
1724
1725                 assert((size_t) n < sizeof(buf));
1726                 buf[n] = 0;
1727                 if (!(tags = strv_split(buf, "\n\r")))
1728                         return -ENOMEM;
1729
1730                 log_debug("Got notification message for unit %s", u->meta.id);
1731
1732                 if (UNIT_VTABLE(u)->notify_message)
1733                         UNIT_VTABLE(u)->notify_message(u, ucred->pid, tags);
1734
1735                 strv_free(tags);
1736         }
1737
1738         return 0;
1739 }
1740
1741 static int manager_dispatch_sigchld(Manager *m) {
1742         assert(m);
1743
1744         for (;;) {
1745                 siginfo_t si;
1746                 Unit *u;
1747                 int r;
1748
1749                 zero(si);
1750
1751                 /* First we call waitd() for a PID and do not reap the
1752                  * zombie. That way we can still access /proc/$PID for
1753                  * it while it is a zombie. */
1754                 if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG|WNOWAIT) < 0) {
1755
1756                         if (errno == ECHILD)
1757                                 break;
1758
1759                         if (errno == EINTR)
1760                                 continue;
1761
1762                         return -errno;
1763                 }
1764
1765                 if (si.si_pid <= 0)
1766                         break;
1767
1768                 if (si.si_code == CLD_EXITED || si.si_code == CLD_KILLED || si.si_code == CLD_DUMPED) {
1769                         char *name = NULL;
1770
1771                         get_process_name(si.si_pid, &name);
1772                         log_debug("Got SIGCHLD for process %lu (%s)", (unsigned long) si.si_pid, strna(name));
1773                         free(name);
1774                 }
1775
1776                 /* Let's flush any message the dying child might still
1777                  * have queued for us. This ensures that the process
1778                  * still exists in /proc so that we can figure out
1779                  * which cgroup and hence unit it belongs to. */
1780                 if ((r = manager_process_notify_fd(m)) < 0)
1781                         return r;
1782
1783                 /* And now figure out the unit this belongs to */
1784                 if (!(u = hashmap_get(m->watch_pids, LONG_TO_PTR(si.si_pid))))
1785                         u = cgroup_unit_by_pid(m, si.si_pid);
1786
1787                 /* And now, we actually reap the zombie. */
1788                 if (waitid(P_PID, si.si_pid, &si, WEXITED) < 0) {
1789                         if (errno == EINTR)
1790                                 continue;
1791
1792                         return -errno;
1793                 }
1794
1795                 if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
1796                         continue;
1797
1798                 log_debug("Child %lu died (code=%s, status=%i/%s)",
1799                           (long unsigned) si.si_pid,
1800                           sigchld_code_to_string(si.si_code),
1801                           si.si_status,
1802                           strna(si.si_code == CLD_EXITED ? exit_status_to_string(si.si_status) : signal_to_string(si.si_status)));
1803
1804                 if (!u)
1805                         continue;
1806
1807                 log_debug("Child %lu belongs to %s", (long unsigned) si.si_pid, u->meta.id);
1808
1809                 hashmap_remove(m->watch_pids, LONG_TO_PTR(si.si_pid));
1810                 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
1811         }
1812
1813         return 0;
1814 }
1815
1816 static int manager_start_target(Manager *m, const char *name, JobMode mode) {
1817         int r;
1818         DBusError error;
1819
1820         dbus_error_init(&error);
1821
1822         log_info("Activating special unit %s", name);
1823
1824         if ((r = manager_add_job_by_name(m, JOB_START, name, mode, true, &error, NULL)) < 0)
1825                 log_error("Failed to enqueue %s job: %s", name, bus_error(&error, r));
1826
1827         dbus_error_free(&error);
1828
1829         return r;
1830 }
1831
1832 static int manager_process_signal_fd(Manager *m) {
1833         ssize_t n;
1834         struct signalfd_siginfo sfsi;
1835         bool sigchld = false;
1836
1837         assert(m);
1838
1839         for (;;) {
1840                 if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
1841
1842                         if (n >= 0)
1843                                 return -EIO;
1844
1845                         if (errno == EAGAIN)
1846                                 break;
1847
1848                         return -errno;
1849                 }
1850
1851                 log_debug("Received SIG%s", strna(signal_to_string(sfsi.ssi_signo)));
1852
1853                 switch (sfsi.ssi_signo) {
1854
1855                 case SIGCHLD:
1856                         sigchld = true;
1857                         break;
1858
1859                 case SIGTERM:
1860                         if (m->running_as == MANAGER_SYSTEM) {
1861                                 /* This is for compatibility with the
1862                                  * original sysvinit */
1863                                 m->exit_code = MANAGER_REEXECUTE;
1864                                 break;
1865                         }
1866
1867                         /* Fall through */
1868
1869                 case SIGINT:
1870                         if (m->running_as == MANAGER_SYSTEM) {
1871                                 manager_start_target(m, SPECIAL_CTRL_ALT_DEL_TARGET, JOB_REPLACE);
1872                                 break;
1873                         }
1874
1875                         /* Run the exit target if there is one, if not, just exit. */
1876                         if (manager_start_target(m, SPECIAL_EXIT_SERVICE, JOB_REPLACE) < 0) {
1877                                 m->exit_code = MANAGER_EXIT;
1878                                 return 0;
1879                         }
1880
1881                         break;
1882
1883                 case SIGWINCH:
1884                         if (m->running_as == MANAGER_SYSTEM)
1885                                 manager_start_target(m, SPECIAL_KBREQUEST_TARGET, JOB_REPLACE);
1886
1887                         /* This is a nop on non-init */
1888                         break;
1889
1890                 case SIGPWR:
1891                         if (m->running_as == MANAGER_SYSTEM)
1892                                 manager_start_target(m, SPECIAL_SIGPWR_TARGET, JOB_REPLACE);
1893
1894                         /* This is a nop on non-init */
1895                         break;
1896
1897                 case SIGUSR1: {
1898                         Unit *u;
1899
1900                         u = manager_get_unit(m, SPECIAL_DBUS_SERVICE);
1901
1902                         if (!u || UNIT_IS_ACTIVE_OR_RELOADING(unit_active_state(u))) {
1903                                 log_info("Trying to reconnect to bus...");
1904                                 bus_init(m);
1905                         }
1906
1907                         if (!u || !UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u))) {
1908                                 log_info("Loading D-Bus service...");
1909                                 manager_start_target(m, SPECIAL_DBUS_SERVICE, JOB_REPLACE);
1910                         }
1911
1912                         break;
1913                 }
1914
1915                 case SIGUSR2: {
1916                         FILE *f;
1917                         char *dump = NULL;
1918                         size_t size;
1919
1920                         if (!(f = open_memstream(&dump, &size))) {
1921                                 log_warning("Failed to allocate memory stream.");
1922                                 break;
1923                         }
1924
1925                         manager_dump_units(m, f, "\t");
1926                         manager_dump_jobs(m, f, "\t");
1927
1928                         if (ferror(f)) {
1929                                 fclose(f);
1930                                 free(dump);
1931                                 log_warning("Failed to write status stream");
1932                                 break;
1933                         }
1934
1935                         fclose(f);
1936                         log_dump(LOG_INFO, dump);
1937                         free(dump);
1938
1939                         break;
1940                 }
1941
1942                 case SIGHUP:
1943                         m->exit_code = MANAGER_RELOAD;
1944                         break;
1945
1946                 default: {
1947                         static const char * const table[] = {
1948                                 [0] = SPECIAL_DEFAULT_TARGET,
1949                                 [1] = SPECIAL_RESCUE_TARGET,
1950                                 [2] = SPECIAL_EMERGENCY_SERVICE,
1951                                 [3] = SPECIAL_HALT_TARGET,
1952                                 [4] = SPECIAL_POWEROFF_TARGET,
1953                                 [5] = SPECIAL_REBOOT_TARGET
1954                         };
1955
1956                         if ((int) sfsi.ssi_signo >= SIGRTMIN+0 &&
1957                             (int) sfsi.ssi_signo < SIGRTMIN+(int) ELEMENTSOF(table)) {
1958                                 manager_start_target(m, table[sfsi.ssi_signo - SIGRTMIN],
1959                                                      (sfsi.ssi_signo == 1 || sfsi.ssi_signo == 2) ? JOB_ISOLATE : JOB_REPLACE);
1960                                 break;
1961                         }
1962
1963                         log_warning("Got unhandled signal <%s>.", strna(signal_to_string(sfsi.ssi_signo)));
1964                 }
1965                 }
1966         }
1967
1968         if (sigchld)
1969                 return manager_dispatch_sigchld(m);
1970
1971         return 0;
1972 }
1973
1974 static int process_event(Manager *m, struct epoll_event *ev) {
1975         int r;
1976         Watch *w;
1977
1978         assert(m);
1979         assert(ev);
1980
1981         assert(w = ev->data.ptr);
1982
1983         switch (w->type) {
1984
1985         case WATCH_SIGNAL:
1986
1987                 /* An incoming signal? */
1988                 if (ev->events != EPOLLIN)
1989                         return -EINVAL;
1990
1991                 if ((r = manager_process_signal_fd(m)) < 0)
1992                         return r;
1993
1994                 break;
1995
1996         case WATCH_NOTIFY:
1997
1998                 /* An incoming daemon notification event? */
1999                 if (ev->events != EPOLLIN)
2000                         return -EINVAL;
2001
2002                 if ((r = manager_process_notify_fd(m)) < 0)
2003                         return r;
2004
2005                 break;
2006
2007         case WATCH_FD:
2008
2009                 /* Some fd event, to be dispatched to the units */
2010                 UNIT_VTABLE(w->data.unit)->fd_event(w->data.unit, w->fd, ev->events, w);
2011                 break;
2012
2013         case WATCH_TIMER: {
2014                 uint64_t v;
2015                 ssize_t k;
2016
2017                 /* Some timer event, to be dispatched to the units */
2018                 if ((k = read(w->fd, &v, sizeof(v))) != sizeof(v)) {
2019
2020                         if (k < 0 && (errno == EINTR || errno == EAGAIN))
2021                                 break;
2022
2023                         return k < 0 ? -errno : -EIO;
2024                 }
2025
2026                 UNIT_VTABLE(w->data.unit)->timer_event(w->data.unit, v, w);
2027                 break;
2028         }
2029
2030         case WATCH_MOUNT:
2031                 /* Some mount table change, intended for the mount subsystem */
2032                 mount_fd_event(m, ev->events);
2033                 break;
2034
2035         case WATCH_UDEV:
2036                 /* Some notification from udev, intended for the device subsystem */
2037                 device_fd_event(m, ev->events);
2038                 break;
2039
2040         case WATCH_DBUS_WATCH:
2041                 bus_watch_event(m, w, ev->events);
2042                 break;
2043
2044         case WATCH_DBUS_TIMEOUT:
2045                 bus_timeout_event(m, w, ev->events);
2046                 break;
2047
2048         default:
2049                 assert_not_reached("Unknown epoll event type.");
2050         }
2051
2052         return 0;
2053 }
2054
2055 int manager_loop(Manager *m) {
2056         int r;
2057
2058         RATELIMIT_DEFINE(rl, 1*USEC_PER_SEC, 1000);
2059
2060         assert(m);
2061         m->exit_code = MANAGER_RUNNING;
2062
2063         /* Release the path cache */
2064         set_free_free(m->unit_path_cache);
2065         m->unit_path_cache = NULL;
2066
2067         /* There might still be some zombies hanging around from
2068          * before we were exec()'ed. Leat's reap them */
2069         if ((r = manager_dispatch_sigchld(m)) < 0)
2070                 return r;
2071
2072         while (m->exit_code == MANAGER_RUNNING) {
2073                 struct epoll_event event;
2074                 int n;
2075
2076                 if (!ratelimit_test(&rl)) {
2077                         /* Yay, something is going seriously wrong, pause a little */
2078                         log_warning("Looping too fast. Throttling execution a little.");
2079                         sleep(1);
2080                 }
2081
2082                 if (manager_dispatch_load_queue(m) > 0)
2083                         continue;
2084
2085                 if (manager_dispatch_run_queue(m) > 0)
2086                         continue;
2087
2088                 if (bus_dispatch(m) > 0)
2089                         continue;
2090
2091                 if (manager_dispatch_cleanup_queue(m) > 0)
2092                         continue;
2093
2094                 if (manager_dispatch_gc_queue(m) > 0)
2095                         continue;
2096
2097                 if (manager_dispatch_dbus_queue(m) > 0)
2098                         continue;
2099
2100                 if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) {
2101
2102                         if (errno == EINTR)
2103                                 continue;
2104
2105                         return -errno;
2106                 }
2107
2108                 assert(n == 1);
2109
2110                 if ((r = process_event(m, &event)) < 0)
2111                         return r;
2112         }
2113
2114         return m->exit_code;
2115 }
2116
2117 int manager_get_unit_from_dbus_path(Manager *m, const char *s, Unit **_u) {
2118         char *n;
2119         Unit *u;
2120
2121         assert(m);
2122         assert(s);
2123         assert(_u);
2124
2125         if (!startswith(s, "/org/freedesktop/systemd1/unit/"))
2126                 return -EINVAL;
2127
2128         if (!(n = bus_path_unescape(s+31)))
2129                 return -ENOMEM;
2130
2131         u = manager_get_unit(m, n);
2132         free(n);
2133
2134         if (!u)
2135                 return -ENOENT;
2136
2137         *_u = u;
2138
2139         return 0;
2140 }
2141
2142 int manager_get_job_from_dbus_path(Manager *m, const char *s, Job **_j) {
2143         Job *j;
2144         unsigned id;
2145         int r;
2146
2147         assert(m);
2148         assert(s);
2149         assert(_j);
2150
2151         if (!startswith(s, "/org/freedesktop/systemd1/job/"))
2152                 return -EINVAL;
2153
2154         if ((r = safe_atou(s + 30, &id)) < 0)
2155                 return r;
2156
2157         if (!(j = manager_get_job(m, id)))
2158                 return -ENOENT;
2159
2160         *_j = j;
2161
2162         return 0;
2163 }
2164
2165 static bool manager_utmp_good(Manager *m) {
2166         int r;
2167
2168         assert(m);
2169
2170         if ((r = mount_path_is_mounted(m, _PATH_UTMPX)) <= 0) {
2171
2172                 if (r < 0)
2173                         log_warning("Failed to determine whether " _PATH_UTMPX " is mounted: %s", strerror(-r));
2174
2175                 return false;
2176         }
2177
2178         return true;
2179 }
2180
2181 void manager_write_utmp_reboot(Manager *m) {
2182         int r;
2183
2184         assert(m);
2185
2186         if (m->utmp_reboot_written)
2187                 return;
2188
2189         if (m->running_as != MANAGER_SYSTEM)
2190                 return;
2191
2192         if (!manager_utmp_good(m))
2193                 return;
2194
2195         if ((r = utmp_put_reboot(m->startup_timestamp.realtime)) < 0) {
2196
2197                 if (r != -ENOENT && r != -EROFS)
2198                         log_warning("Failed to write utmp/wtmp: %s", strerror(-r));
2199
2200                 return;
2201         }
2202
2203         m->utmp_reboot_written = true;
2204 }
2205
2206 void manager_write_utmp_runlevel(Manager *m, Unit *u) {
2207         int runlevel, r;
2208
2209         assert(m);
2210         assert(u);
2211
2212         if (u->meta.type != UNIT_TARGET)
2213                 return;
2214
2215         if (m->running_as != MANAGER_SYSTEM)
2216                 return;
2217
2218         if (!manager_utmp_good(m))
2219                 return;
2220
2221         if ((runlevel = target_get_runlevel(TARGET(u))) <= 0)
2222                 return;
2223
2224         if ((r = utmp_put_runlevel(0, runlevel, 0)) < 0) {
2225
2226                 if (r != -ENOENT && r != -EROFS)
2227                         log_warning("Failed to write utmp/wtmp: %s", strerror(-r));
2228         }
2229 }
2230
2231 void manager_dispatch_bus_name_owner_changed(
2232                 Manager *m,
2233                 const char *name,
2234                 const char* old_owner,
2235                 const char *new_owner) {
2236
2237         Unit *u;
2238
2239         assert(m);
2240         assert(name);
2241
2242         if (!(u = hashmap_get(m->watch_bus, name)))
2243                 return;
2244
2245         UNIT_VTABLE(u)->bus_name_owner_change(u, name, old_owner, new_owner);
2246 }
2247
2248 void manager_dispatch_bus_query_pid_done(
2249                 Manager *m,
2250                 const char *name,
2251                 pid_t pid) {
2252
2253         Unit *u;
2254
2255         assert(m);
2256         assert(name);
2257         assert(pid >= 1);
2258
2259         if (!(u = hashmap_get(m->watch_bus, name)))
2260                 return;
2261
2262         UNIT_VTABLE(u)->bus_query_pid_done(u, name, pid);
2263 }
2264
2265 int manager_open_serialization(FILE **_f) {
2266         char *path;
2267         mode_t saved_umask;
2268         int fd;
2269         FILE *f;
2270
2271         assert(_f);
2272
2273         if (asprintf(&path, "/dev/shm/systemd-%u.dump-XXXXXX", (unsigned) getpid()) < 0)
2274                 return -ENOMEM;
2275
2276         saved_umask = umask(0077);
2277         fd = mkostemp(path, O_RDWR|O_CLOEXEC);
2278         umask(saved_umask);
2279
2280         if (fd < 0) {
2281                 free(path);
2282                 return -errno;
2283         }
2284
2285         unlink(path);
2286
2287         log_debug("Serializing state to %s", path);
2288         free(path);
2289
2290         if (!(f = fdopen(fd, "w+")) < 0)
2291                 return -errno;
2292
2293         *_f = f;
2294
2295         return 0;
2296 }
2297
2298 int manager_serialize(Manager *m, FILE *f, FDSet *fds) {
2299         Iterator i;
2300         Unit *u;
2301         const char *t;
2302         int r;
2303
2304         assert(m);
2305         assert(f);
2306         assert(fds);
2307
2308         HASHMAP_FOREACH_KEY(u, t, m->units, i) {
2309                 if (u->meta.id != t)
2310                         continue;
2311
2312                 if (!unit_can_serialize(u))
2313                         continue;
2314
2315                 /* Start marker */
2316                 fputs(u->meta.id, f);
2317                 fputc('\n', f);
2318
2319                 if ((r = unit_serialize(u, f, fds)) < 0)
2320                         return r;
2321         }
2322
2323         if (ferror(f))
2324                 return -EIO;
2325
2326         return 0;
2327 }
2328
2329 int manager_deserialize(Manager *m, FILE *f, FDSet *fds) {
2330         int r = 0;
2331
2332         assert(m);
2333         assert(f);
2334
2335         log_debug("Deserializing state...");
2336
2337         m->deserializing = true;
2338
2339         for (;;) {
2340                 Unit *u;
2341                 char name[UNIT_NAME_MAX+2];
2342
2343                 /* Start marker */
2344                 if (!fgets(name, sizeof(name), f)) {
2345                         if (feof(f))
2346                                 break;
2347
2348                         r = -errno;
2349                         goto finish;
2350                 }
2351
2352                 char_array_0(name);
2353
2354                 if ((r = manager_load_unit(m, strstrip(name), NULL, NULL, &u)) < 0)
2355                         goto finish;
2356
2357                 if ((r = unit_deserialize(u, f, fds)) < 0)
2358                         goto finish;
2359         }
2360
2361         if (ferror(f)) {
2362                 r = -EIO;
2363                 goto finish;
2364         }
2365
2366         r = 0;
2367
2368 finish:
2369         m->deserializing = false;
2370
2371         return r;
2372 }
2373
2374 int manager_reload(Manager *m) {
2375         int r, q;
2376         FILE *f;
2377         FDSet *fds;
2378
2379         assert(m);
2380
2381         if ((r = manager_open_serialization(&f)) < 0)
2382                 return r;
2383
2384         if (!(fds = fdset_new())) {
2385                 r = -ENOMEM;
2386                 goto finish;
2387         }
2388
2389         if ((r = manager_serialize(m, f, fds)) < 0)
2390                 goto finish;
2391
2392         if (fseeko(f, 0, SEEK_SET) < 0) {
2393                 r = -errno;
2394                 goto finish;
2395         }
2396
2397         /* From here on there is no way back. */
2398         manager_clear_jobs_and_units(m);
2399
2400         /* Find new unit paths */
2401         lookup_paths_free(&m->lookup_paths);
2402         if ((q = lookup_paths_init(&m->lookup_paths, m->running_as)) < 0)
2403                 r = q;
2404
2405         /* First, enumerate what we can from all config files */
2406         if ((q = manager_enumerate(m)) < 0)
2407                 r = q;
2408
2409         /* Second, deserialize our stored data */
2410         if ((q = manager_deserialize(m, f, fds)) < 0)
2411                 r = q;
2412
2413         fclose(f);
2414         f = NULL;
2415
2416         /* Third, fire things up! */
2417         if ((q = manager_coldplug(m)) < 0)
2418                 r = q;
2419
2420 finish:
2421         if (f)
2422                 fclose(f);
2423
2424         if (fds)
2425                 fdset_free(fds);
2426
2427         return r;
2428 }
2429
2430 bool manager_is_booting_or_shutting_down(Manager *m) {
2431         Unit *u;
2432
2433         assert(m);
2434
2435         /* Is the initial job still around? */
2436         if (manager_get_job(m, 1))
2437                 return true;
2438
2439         /* Is there a job for the shutdown target? */
2440         if (((u = manager_get_unit(m, SPECIAL_SHUTDOWN_TARGET))))
2441                 return !!u->meta.job;
2442
2443         return false;
2444 }
2445
2446 static const char* const manager_running_as_table[_MANAGER_RUNNING_AS_MAX] = {
2447         [MANAGER_SYSTEM] = "system",
2448         [MANAGER_SESSION] = "session"
2449 };
2450
2451 DEFINE_STRING_TABLE_LOOKUP(manager_running_as, ManagerRunningAs);