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
  40 #include "manager.h"
  41 #include "hashmap.h"
  42 #include "macro.h"
  43 #include "strv.h"
  44 #include "log.h"
  45 #include "util.h"
  46 #include "ratelimit.h"
  47 #include "cgroup.h"
  48 #include "mount-setup.h"
  49 #include "utmp-wtmp.h"
  50 #include "unit-name.h"
  51 #include "dbus-unit.h"
  52 #include "dbus-job.h"
  53 #include "missing.h"
  54 #include "path-lookup.h"
  55 #include "special.h"
  56 #include "bus-errors.h"
  57
  58 /* As soon as 16 units are in our GC queue, make sure to run a gc sweep */
  59 #define GC_QUEUE_ENTRIES_MAX 16
  60
  61 /* As soon as 5s passed since a unit was added to our GC queue, make sure to run a gc sweep */
  62 #define GC_QUEUE_USEC_MAX (10*USEC_PER_SEC)
  63
  64 /* Where clients shall send notification messages to */
  65 #define NOTIFY_SOCKET "/org/freedesktop/systemd1/notify"
  66
  67 static int manager_setup_notify(Manager *m) {
  68         union {
  69                 struct sockaddr sa;
  70                 struct sockaddr_un un;
  71         } sa;
  72         struct epoll_event ev;
  73         int one = 1;
  74
  75         assert(m);
  76
  77         m->notify_watch.type = WATCH_NOTIFY;
  78         if ((m->notify_watch.fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0)) < 0) {
  79                 log_error("Failed to allocate notification socket: %m");
  80                 return -errno;
  81         }
  82
  83         zero(sa);
  84         sa.sa.sa_family = AF_UNIX;
  85
  86         if (getpid() != 1)
  87                 snprintf(sa.un.sun_path+1, sizeof(sa.un.sun_path)-1, NOTIFY_SOCKET "/%llu", random_ull());
  88         else
  89                 strncpy(sa.un.sun_path+1, NOTIFY_SOCKET, sizeof(sa.un.sun_path)-1);
  90
  91         if (bind(m->notify_watch.fd, &sa.sa, sizeof(sa)) < 0) {
  92                 log_error("bind() failed: %m");
  93                 return -errno;
  94         }
  95
  96         if (setsockopt(m->notify_watch.fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)) < 0) {
  97                 log_error("SO_PASSCRED failed: %m");
  98                 return -errno;
  99         }
 100
 101         zero(ev);
 102         ev.events = EPOLLIN;
 103         ev.data.ptr = &m->notify_watch;
 104
 105         if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->notify_watch.fd, &ev) < 0)
 106                 return -errno;
 107
 108         if (!(m->notify_socket = strdup(sa.un.sun_path+1)))
 109                 return -ENOMEM;
 110
 111         return 0;
 112 }
 113
 114 static int enable_special_signals(Manager *m) {
 115         char fd;
 116
 117         assert(m);
 118
 119         /* Enable that we get SIGINT on control-alt-del */
 120         if (reboot(RB_DISABLE_CAD) < 0)
 121                 log_warning("Failed to enable ctrl-alt-del handling: %m");
 122
 123         if ((fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY)) < 0)
 124                 log_warning("Failed to open /dev/tty0: %m");
 125         else {
 126                 /* Enable that we get SIGWINCH on kbrequest */
 127                 if (ioctl(fd, KDSIGACCEPT, SIGWINCH) < 0)
 128                         log_warning("Failed to enable kbrequest handling: %s", strerror(errno));
 129
 130                 close_nointr_nofail(fd);
 131         }
 132
 133         return 0;
 134 }
 135
 136 static int manager_setup_signals(Manager *m) {
 137         sigset_t mask;
 138         struct epoll_event ev;
 139         struct sigaction sa;
 140
 141         assert(m);
 142
 143         /* We are not interested in SIGSTOP and friends. */
 144         zero(sa);
 145         sa.sa_handler = SIG_DFL;
 146         sa.sa_flags = SA_NOCLDSTOP|SA_RESTART;
 147         assert_se(sigaction(SIGCHLD, &sa, NULL) == 0);
 148
 149         assert_se(sigemptyset(&mask) == 0);
 150
 151         sigset_add_many(&mask,
 152                         SIGCHLD,     /* Child died */
 153                         SIGTERM,     /* Reexecute daemon */
 154                         SIGHUP,      /* Reload configuration */
 155                         SIGUSR1,     /* systemd/upstart: reconnect to D-Bus */
 156                         SIGUSR2,     /* systemd: dump status */
 157                         SIGINT,      /* Kernel sends us this on control-alt-del */
 158                         SIGWINCH,    /* Kernel sends us this on kbrequest (alt-arrowup) */
 159                         SIGPWR,      /* Some kernel drivers and upsd send us this on power failure */
 160                         SIGRTMIN+0,  /* systemd: start default.target */
 161                         SIGRTMIN+1,  /* systemd: start rescue.target */
 162                         SIGRTMIN+2,  /* systemd: isolate emergency.target */
 163                         SIGRTMIN+3,  /* systemd: start halt.target */
 164                         SIGRTMIN+4,  /* systemd: start poweroff.target */
 165                         SIGRTMIN+5,  /* systemd: start reboot.target */
 166                         -1);
 167         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
 168
 169         m->signal_watch.type = WATCH_SIGNAL;
 170         if ((m->signal_watch.fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
 171                 return -errno;
 172
 173         zero(ev);
 174         ev.events = EPOLLIN;
 175         ev.data.ptr = &m->signal_watch;
 176
 177         if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_watch.fd, &ev) < 0)
 178                 return -errno;
 179
 180         if (m->running_as == MANAGER_SYSTEM)
 181                 return enable_special_signals(m);
 182
 183         return 0;
 184 }
 185
 186 int manager_new(ManagerRunningAs running_as, Manager **_m) {
 187         Manager *m;
 188         int r = -ENOMEM;
 189         char *p;
 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         if (asprintf(&p, "%s/%s", m->cgroup_mount_point, m->cgroup_hierarchy) < 0) {
 249                 r = -ENOMEM;
 250                 goto fail;
 251         }
 252
 253         m->pin_cgroupfs_fd = open(p, O_RDONLY|O_CLOEXEC|O_DIRECTORY|O_NOCTTY|O_NONBLOCK);
 254         free(p);
 255
 256         *_m = m;
 257         return 0;
 258
 259 fail:
 260         manager_free(m);
 261         return r;
 262 }
 263
 264 static unsigned manager_dispatch_cleanup_queue(Manager *m) {
 265         Meta *meta;
 266         unsigned n = 0;
 267
 268         assert(m);
 269
 270         while ((meta = m->cleanup_queue)) {
 271                 assert(meta->in_cleanup_queue);
 272
 273                 unit_free((Unit*) meta);
 274                 n++;
 275         }
 276
 277         return n;
 278 }
 279
 280 enum {
 281         GC_OFFSET_IN_PATH,  /* This one is on the path we were travelling */
 282         GC_OFFSET_UNSURE,   /* No clue */
 283         GC_OFFSET_GOOD,     /* We still need this unit */
 284         GC_OFFSET_BAD,      /* We don't need this unit anymore */
 285         _GC_OFFSET_MAX
 286 };
 287
 288 static void unit_gc_sweep(Unit *u, unsigned gc_marker) {
 289         Iterator i;
 290         Unit *other;
 291         bool is_bad;
 292
 293         assert(u);
 294
 295         if (u->meta.gc_marker == gc_marker + GC_OFFSET_GOOD ||
 296             u->meta.gc_marker == gc_marker + GC_OFFSET_BAD ||
 297             u->meta.gc_marker == gc_marker + GC_OFFSET_IN_PATH)
 298                 return;
 299
 300         if (u->meta.in_cleanup_queue)
 301                 goto bad;
 302
 303         if (unit_check_gc(u))
 304                 goto good;
 305
 306         u->meta.gc_marker = gc_marker + GC_OFFSET_IN_PATH;
 307
 308         is_bad = true;
 309
 310         SET_FOREACH(other, u->meta.dependencies[UNIT_REFERENCED_BY], i) {
 311                 unit_gc_sweep(other, gc_marker);
 312
 313                 if (other->meta.gc_marker == gc_marker + GC_OFFSET_GOOD)
 314                         goto good;
 315
 316                 if (other->meta.gc_marker != gc_marker + GC_OFFSET_BAD)
 317                         is_bad = false;
 318         }
 319
 320         if (is_bad)
 321                 goto bad;
 322
 323         /* We were unable to find anything out about this entry, so
 324          * let's investigate it later */
 325         u->meta.gc_marker = gc_marker + GC_OFFSET_UNSURE;
 326         unit_add_to_gc_queue(u);
 327         return;
 328
 329 bad:
 330         /* We definitely know that this one is not useful anymore, so
 331          * let's mark it for deletion */
 332         u->meta.gc_marker = gc_marker + GC_OFFSET_BAD;
 333         unit_add_to_cleanup_queue(u);
 334         return;
 335
 336 good:
 337         u->meta.gc_marker = gc_marker + GC_OFFSET_GOOD;
 338 }
 339
 340 static unsigned manager_dispatch_gc_queue(Manager *m) {
 341         Meta *meta;
 342         unsigned n = 0;
 343         unsigned gc_marker;
 344
 345         assert(m);
 346
 347         if ((m->n_in_gc_queue < GC_QUEUE_ENTRIES_MAX) &&
 348             (m->gc_queue_timestamp <= 0 ||
 349              (m->gc_queue_timestamp + GC_QUEUE_USEC_MAX) > now(CLOCK_MONOTONIC)))
 350                 return 0;
 351
 352         log_debug("Running GC...");
 353
 354         m->gc_marker += _GC_OFFSET_MAX;
 355         if (m->gc_marker + _GC_OFFSET_MAX <= _GC_OFFSET_MAX)
 356                 m->gc_marker = 1;
 357
 358         gc_marker = m->gc_marker;
 359
 360         while ((meta = m->gc_queue)) {
 361                 assert(meta->in_gc_queue);
 362
 363                 unit_gc_sweep((Unit*) meta, gc_marker);
 364
 365                 LIST_REMOVE(Meta, gc_queue, m->gc_queue, meta);
 366                 meta->in_gc_queue = false;
 367
 368                 n++;
 369
 370                 if (meta->gc_marker == gc_marker + GC_OFFSET_BAD ||
 371                     meta->gc_marker == gc_marker + GC_OFFSET_UNSURE) {
 372                         log_debug("Collecting %s", meta->id);
 373                         meta->gc_marker = gc_marker + GC_OFFSET_BAD;
 374                         unit_add_to_cleanup_queue((Unit*) meta);
 375                 }
 376         }
 377
 378         m->n_in_gc_queue = 0;
 379         m->gc_queue_timestamp = 0;
 380
 381         return n;
 382 }
 383
 384 static void manager_clear_jobs_and_units(Manager *m) {
 385         Job *j;
 386         Unit *u;
 387
 388         assert(m);
 389
 390         while ((j = hashmap_first(m->transaction_jobs)))
 391                 job_free(j);
 392
 393         while ((u = hashmap_first(m->units)))
 394                 unit_free(u);
 395
 396         manager_dispatch_cleanup_queue(m);
 397
 398         assert(!m->load_queue);
 399         assert(!m->run_queue);
 400         assert(!m->dbus_unit_queue);
 401         assert(!m->dbus_job_queue);
 402         assert(!m->cleanup_queue);
 403         assert(!m->gc_queue);
 404
 405         assert(hashmap_isempty(m->transaction_jobs));
 406         assert(hashmap_isempty(m->jobs));
 407         assert(hashmap_isempty(m->units));
 408 }
 409
 410 void manager_free(Manager *m) {
 411         UnitType c;
 412
 413         assert(m);
 414
 415         manager_clear_jobs_and_units(m);
 416
 417         for (c = 0; c < _UNIT_TYPE_MAX; c++)
 418                 if (unit_vtable[c]->shutdown)
 419                         unit_vtable[c]->shutdown(m);
 420
 421         /* If we reexecute ourselves, we keep the root cgroup
 422          * around */
 423         if (m->exit_code != MANAGER_REEXECUTE)
 424                 manager_shutdown_cgroup(m);
 425
 426         bus_done(m);
 427
 428         hashmap_free(m->units);
 429         hashmap_free(m->jobs);
 430         hashmap_free(m->transaction_jobs);
 431         hashmap_free(m->watch_pids);
 432         hashmap_free(m->watch_bus);
 433
 434         if (m->epoll_fd >= 0)
 435                 close_nointr_nofail(m->epoll_fd);
 436         if (m->signal_watch.fd >= 0)
 437                 close_nointr_nofail(m->signal_watch.fd);
 438         if (m->notify_watch.fd >= 0)
 439                 close_nointr_nofail(m->notify_watch.fd);
 440
 441         free(m->notify_socket);
 442
 443         lookup_paths_free(&m->lookup_paths);
 444         strv_free(m->environment);
 445
 446         free(m->cgroup_hierarchy);
 447         free(m->cgroup_mount_point);
 448
 449         hashmap_free(m->cgroup_bondings);
 450
 451         if (m->pin_cgroupfs_fd >= 0)
 452                 close_nointr_nofail(m->pin_cgroupfs_fd);
 453
 454         free(m);
 455 }
 456
 457 int manager_enumerate(Manager *m) {
 458         int r = 0, q;
 459         UnitType c;
 460
 461         assert(m);
 462
 463         /* Let's ask every type to load all units from disk/kernel
 464          * that it might know */
 465         for (c = 0; c < _UNIT_TYPE_MAX; c++)
 466                 if (unit_vtable[c]->enumerate)
 467                         if ((q = unit_vtable[c]->enumerate(m)) < 0)
 468                                 r = q;
 469
 470         manager_dispatch_load_queue(m);
 471         return r;
 472 }
 473
 474 int manager_coldplug(Manager *m) {
 475         int r = 0, q;
 476         Iterator i;
 477         Unit *u;
 478         char *k;
 479
 480         assert(m);
 481
 482         /* Then, let's set up their initial state. */
 483         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
 484
 485                 /* ignore aliases */
 486                 if (u->meta.id != k)
 487                         continue;
 488
 489                 if ((q = unit_coldplug(u)) < 0)
 490                         r = q;
 491         }
 492
 493         return r;
 494 }
 495
 496 int manager_startup(Manager *m, FILE *serialization, FDSet *fds) {
 497         int r, q;
 498
 499         assert(m);
 500
 501         /* First, enumerate what we can from all config files */
 502         r = manager_enumerate(m);
 503
 504         /* Second, deserialize if there is something to deserialize */
 505         if (serialization)
 506                 if ((q = manager_deserialize(m, serialization, fds)) < 0)
 507                         r = q;
 508
 509         /* Third, fire things up! */
 510         if ((q = manager_coldplug(m)) < 0)
 511                 r = q;
 512
 513         /* Now that the initial devices are available, let's see if we
 514          * can write the utmp file */
 515         manager_write_utmp_reboot(m);
 516
 517         return r;
 518 }
 519
 520 static void transaction_delete_job(Manager *m, Job *j, bool delete_dependencies) {
 521         assert(m);
 522         assert(j);
 523
 524         /* Deletes one job from the transaction */
 525
 526         manager_transaction_unlink_job(m, j, delete_dependencies);
 527
 528         if (!j->installed)
 529                 job_free(j);
 530 }
 531
 532 static void transaction_delete_unit(Manager *m, Unit *u) {
 533         Job *j;
 534
 535         /* Deletes all jobs associated with a certain unit from the
 536          * transaction */
 537
 538         while ((j = hashmap_get(m->transaction_jobs, u)))
 539                 transaction_delete_job(m, j, true);
 540 }
 541
 542 static void transaction_clean_dependencies(Manager *m) {
 543         Iterator i;
 544         Job *j;
 545
 546         assert(m);
 547
 548         /* Drops all dependencies of all installed jobs */
 549
 550         HASHMAP_FOREACH(j, m->jobs, i) {
 551                 while (j->subject_list)
 552                         job_dependency_free(j->subject_list);
 553                 while (j->object_list)
 554                         job_dependency_free(j->object_list);
 555         }
 556
 557         assert(!m->transaction_anchor);
 558 }
 559
 560 static void transaction_abort(Manager *m) {
 561         Job *j;
 562
 563         assert(m);
 564
 565         while ((j = hashmap_first(m->transaction_jobs)))
 566                 if (j->installed)
 567                         transaction_delete_job(m, j, true);
 568                 else
 569                         job_free(j);
 570
 571         assert(hashmap_isempty(m->transaction_jobs));
 572
 573         transaction_clean_dependencies(m);
 574 }
 575
 576 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
 577         JobDependency *l;
 578
 579         assert(m);
 580
 581         /* A recursive sweep through the graph that marks all units
 582          * that matter to the anchor job, i.e. are directly or
 583          * indirectly a dependency of the anchor job via paths that
 584          * are fully marked as mattering. */
 585
 586         if (j)
 587                 l = j->subject_list;
 588         else
 589                 l = m->transaction_anchor;
 590
 591         LIST_FOREACH(subject, l, l) {
 592
 593                 /* This link does not matter */
 594                 if (!l->matters)
 595                         continue;
 596
 597                 /* This unit has already been marked */
 598                 if (l->object->generation == generation)
 599                         continue;
 600
 601                 l->object->matters_to_anchor = true;
 602                 l->object->generation = generation;
 603
 604                 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
 605         }
 606 }
 607
 608 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
 609         JobDependency *l, *last;
 610
 611         assert(j);
 612         assert(other);
 613         assert(j->unit == other->unit);
 614         assert(!j->installed);
 615
 616         /* Merges 'other' into 'j' and then deletes j. */
 617
 618         j->type = t;
 619         j->state = JOB_WAITING;
 620         j->override = j->override || other->override;
 621
 622         j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
 623
 624         /* Patch us in as new owner of the JobDependency objects */
 625         last = NULL;
 626         LIST_FOREACH(subject, l, other->subject_list) {
 627                 assert(l->subject == other);
 628                 l->subject = j;
 629                 last = l;
 630         }
 631
 632         /* Merge both lists */
 633         if (last) {
 634                 last->subject_next = j->subject_list;
 635                 if (j->subject_list)
 636                         j->subject_list->subject_prev = last;
 637                 j->subject_list = other->subject_list;
 638         }
 639
 640         /* Patch us in as new owner of the JobDependency objects */
 641         last = NULL;
 642         LIST_FOREACH(object, l, other->object_list) {
 643                 assert(l->object == other);
 644                 l->object = j;
 645                 last = l;
 646         }
 647
 648         /* Merge both lists */
 649         if (last) {
 650                 last->object_next = j->object_list;
 651                 if (j->object_list)
 652                         j->object_list->object_prev = last;
 653                 j->object_list = other->object_list;
 654         }
 655
 656         /* Kill the other job */
 657         other->subject_list = NULL;
 658         other->object_list = NULL;
 659         transaction_delete_job(m, other, true);
 660 }
 661
 662 static int delete_one_unmergeable_job(Manager *m, Job *j) {
 663         Job *k;
 664
 665         assert(j);
 666
 667         /* Tries to delete one item in the linked list
 668          * j->transaction_next->transaction_next->... that conflicts
 669          * whith another one, in an attempt to make an inconsistent
 670          * transaction work. */
 671
 672         /* We rely here on the fact that if a merged with b does not
 673          * merge with c, either a or b merge with c neither */
 674         LIST_FOREACH(transaction, j, j)
 675                 LIST_FOREACH(transaction, k, j->transaction_next) {
 676                         Job *d;
 677
 678                         /* Is this one mergeable? Then skip it */
 679                         if (job_type_is_mergeable(j->type, k->type))
 680                                 continue;
 681
 682                         /* Ok, we found two that conflict, let's see if we can
 683                          * drop one of them */
 684                         if (!j->matters_to_anchor)
 685                                 d = j;
 686                         else if (!k->matters_to_anchor)
 687                                 d = k;
 688                         else
 689                                 return -ENOEXEC;
 690
 691                         /* Ok, we can drop one, so let's do so. */
 692                         log_notice("Trying to fix job merging by deleting job %s/%s", d->unit->meta.id, job_type_to_string(d->type));
 693                         transaction_delete_job(m, d, true);
 694                         return 0;
 695                 }
 696
 697         return -EINVAL;
 698 }
 699
 700 static int transaction_merge_jobs(Manager *m, DBusError *e) {
 701         Job *j;
 702         Iterator i;
 703         int r;
 704
 705         assert(m);
 706
 707         /* First step, check whether any of the jobs for one specific
 708          * task conflict. If so, try to drop one of them. */
 709         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 710                 JobType t;
 711                 Job *k;
 712
 713                 t = j->type;
 714                 LIST_FOREACH(transaction, k, j->transaction_next) {
 715                         if ((r = job_type_merge(&t, k->type)) >= 0)
 716                                 continue;
 717
 718                         /* OK, we could not merge all jobs for this
 719                          * action. Let's see if we can get rid of one
 720                          * of them */
 721
 722                         if ((r = delete_one_unmergeable_job(m, j)) >= 0)
 723                                 /* Ok, we managed to drop one, now
 724                                  * let's ask our callers to call us
 725                                  * again after garbage collecting */
 726                                 return -EAGAIN;
 727
 728                         /* We couldn't merge anything. Failure */
 729                         dbus_set_error(e, BUS_ERROR_TRANSACTION_JOBS_CONFLICTING, "Transaction contains conflicting jobs '%s' and '%s' for %s. Probably contradicting requirement dependencies configured.",
 730                                        job_type_to_string(t), job_type_to_string(k->type), k->unit->meta.id);
 731                         return r;
 732                 }
 733         }
 734
 735         /* Second step, merge the jobs. */
 736         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 737                 JobType t = j->type;
 738                 Job *k;
 739
 740                 /* Merge all transactions */
 741                 LIST_FOREACH(transaction, k, j->transaction_next)
 742                         assert_se(job_type_merge(&t, k->type) == 0);
 743
 744                 /* If an active job is mergeable, merge it too */
 745                 if (j->unit->meta.job)
 746                         job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
 747
 748                 while ((k = j->transaction_next)) {
 749                         if (j->installed) {
 750                                 transaction_merge_and_delete_job(m, k, j, t);
 751                                 j = k;
 752                         } else
 753                                 transaction_merge_and_delete_job(m, j, k, t);
 754                 }
 755
 756                 assert(!j->transaction_next);
 757                 assert(!j->transaction_prev);
 758         }
 759
 760         return 0;
 761 }
 762
 763 static void transaction_drop_redundant(Manager *m) {
 764         bool again;
 765
 766         assert(m);
 767
 768         /* Goes through the transaction and removes all jobs that are
 769          * a noop */
 770
 771         do {
 772                 Job *j;
 773                 Iterator i;
 774
 775                 again = false;
 776
 777                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 778                         bool changes_something = false;
 779                         Job *k;
 780
 781                         LIST_FOREACH(transaction, k, j) {
 782
 783                                 if (!job_is_anchor(k) &&
 784                                     job_type_is_redundant(k->type, unit_active_state(k->unit)))
 785                                         continue;
 786
 787                                 changes_something = true;
 788                                 break;
 789                         }
 790
 791                         if (changes_something)
 792                                 continue;
 793
 794                         log_debug("Found redundant job %s/%s, dropping.", j->unit->meta.id, job_type_to_string(j->type));
 795                         transaction_delete_job(m, j, false);
 796                         again = true;
 797                         break;
 798                 }
 799
 800         } while (again);
 801 }
 802
 803 static bool unit_matters_to_anchor(Unit *u, Job *j) {
 804         assert(u);
 805         assert(!j->transaction_prev);
 806
 807         /* Checks whether at least one of the jobs for this unit
 808          * matters to the anchor. */
 809
 810         LIST_FOREACH(transaction, j, j)
 811                 if (j->matters_to_anchor)
 812                         return true;
 813
 814         return false;
 815 }
 816
 817 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation, DBusError *e) {
 818         Iterator i;
 819         Unit *u;
 820         int r;
 821
 822         assert(m);
 823         assert(j);
 824         assert(!j->transaction_prev);
 825
 826         /* Does a recursive sweep through the ordering graph, looking
 827          * for a cycle. If we find cycle we try to break it. */
 828
 829         /* Have we seen this before? */
 830         if (j->generation == generation) {
 831                 Job *k;
 832
 833                 /* If the marker is NULL we have been here already and
 834                  * decided the job was loop-free from here. Hence
 835                  * shortcut things and return right-away. */
 836                 if (!j->marker)
 837                         return 0;
 838
 839                 /* So, the marker is not NULL and we already have been
 840                  * here. We have a cycle. Let's try to break it. We go
 841                  * backwards in our path and try to find a suitable
 842                  * job to remove. We use the marker to find our way
 843                  * back, since smart how we are we stored our way back
 844                  * in there. */
 845                 log_warning("Found ordering cycle on %s/%s", j->unit->meta.id, job_type_to_string(j->type));
 846
 847                 for (k = from; k; k = ((k->generation == generation && k->marker != k) ? k->marker : NULL)) {
 848
 849                         log_info("Walked on cycle path to %s/%s", k->unit->meta.id, job_type_to_string(k->type));
 850
 851                         if (!k->installed &&
 852                             !unit_matters_to_anchor(k->unit, k)) {
 853                                 /* Ok, we can drop this one, so let's
 854                                  * do so. */
 855                                 log_warning("Breaking order cycle by deleting job %s/%s", k->unit->meta.id, job_type_to_string(k->type));
 856                                 transaction_delete_unit(m, k->unit);
 857                                 return -EAGAIN;
 858                         }
 859
 860                         /* Check if this in fact was the beginning of
 861                          * the cycle */
 862                         if (k == j)
 863                                 break;
 864                 }
 865
 866                 log_error("Unable to break cycle");
 867
 868                 dbus_set_error(e, BUS_ERROR_TRANSACTION_ORDER_IS_CYCLIC, "Transaction order is cyclic. See logs for details.");
 869                 return -ENOEXEC;
 870         }
 871
 872         /* Make the marker point to where we come from, so that we can
 873          * find our way backwards if we want to break a cycle. We use
 874          * a special marker for the beginning: we point to
 875          * ourselves. */
 876         j->marker = from ? from : j;
 877         j->generation = generation;
 878
 879         /* We assume that the the dependencies are bidirectional, and
 880          * hence can ignore UNIT_AFTER */
 881         SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
 882                 Job *o;
 883
 884                 /* Is there a job for this unit? */
 885                 if (!(o = hashmap_get(m->transaction_jobs, u)))
 886
 887                         /* Ok, there is no job for this in the
 888                          * transaction, but maybe there is already one
 889                          * running? */
 890                         if (!(o = u->meta.job))
 891                                 continue;
 892
 893                 if ((r = transaction_verify_order_one(m, o, j, generation, e)) < 0)
 894                         return r;
 895         }
 896
 897         /* Ok, let's backtrack, and remember that this entry is not on
 898          * our path anymore. */
 899         j->marker = NULL;
 900
 901         return 0;
 902 }
 903
 904 static int transaction_verify_order(Manager *m, unsigned *generation, DBusError *e) {
 905         Job *j;
 906         int r;
 907         Iterator i;
 908         unsigned g;
 909
 910         assert(m);
 911         assert(generation);
 912
 913         /* Check if the ordering graph is cyclic. If it is, try to fix
 914          * that up by dropping one of the jobs. */
 915
 916         g = (*generation)++;
 917
 918         HASHMAP_FOREACH(j, m->transaction_jobs, i)
 919                 if ((r = transaction_verify_order_one(m, j, NULL, g, e)) < 0)
 920                         return r;
 921
 922         return 0;
 923 }
 924
 925 static void transaction_collect_garbage(Manager *m) {
 926         bool again;
 927
 928         assert(m);
 929
 930         /* Drop jobs that are not required by any other job */
 931
 932         do {
 933                 Iterator i;
 934                 Job *j;
 935
 936                 again = false;
 937
 938                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 939                         if (j->object_list)
 940                                 continue;
 941
 942                         log_debug("Garbage collecting job %s/%s", j->unit->meta.id, job_type_to_string(j->type));
 943                         transaction_delete_job(m, j, true);
 944                         again = true;
 945                         break;
 946                 }
 947
 948         } while (again);
 949 }
 950
 951 static int transaction_is_destructive(Manager *m, DBusError *e) {
 952         Iterator i;
 953         Job *j;
 954
 955         assert(m);
 956
 957         /* Checks whether applying this transaction means that
 958          * existing jobs would be replaced */
 959
 960         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 961
 962                 /* Assume merged */
 963                 assert(!j->transaction_prev);
 964                 assert(!j->transaction_next);
 965
 966                 if (j->unit->meta.job &&
 967                     j->unit->meta.job != j &&
 968                     !job_type_is_superset(j->type, j->unit->meta.job->type)) {
 969
 970                         dbus_set_error(e, BUS_ERROR_TRANSACTION_IS_DESTRUCTIVE, "Transaction is destructive.");
 971                         return -EEXIST;
 972                 }
 973         }
 974
 975         return 0;
 976 }
 977
 978 static void transaction_minimize_impact(Manager *m) {
 979         bool again;
 980         assert(m);
 981
 982         /* Drops all unnecessary jobs that reverse already active jobs
 983          * or that stop a running service. */
 984
 985         do {
 986                 Job *j;
 987                 Iterator i;
 988
 989                 again = false;
 990
 991                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 992                         LIST_FOREACH(transaction, j, j) {
 993                                 bool stops_running_service, changes_existing_job;
 994
 995                                 /* If it matters, we shouldn't drop it */
 996                                 if (j->matters_to_anchor)
 997                                         continue;
 998
 999                                 /* Would this stop a running service?
1000                                  * Would this change an existing job?
1001                                  * If so, let's drop this entry */
1002
1003                                 stops_running_service =
1004                                         j->type == JOB_STOP && UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(j->unit));
1005
1006                                 changes_existing_job =
1007                                         j->unit->meta.job && job_type_is_conflicting(j->type, j->unit->meta.job->state);
1008
1009                                 if (!stops_running_service && !changes_existing_job)
1010                                         continue;
1011
1012                                 if (stops_running_service)
1013                                         log_info("%s/%s would stop a running service.", j->unit->meta.id, job_type_to_string(j->type));
1014
1015                                 if (changes_existing_job)
1016                                         log_info("%s/%s would change existing job.", j->unit->meta.id, job_type_to_string(j->type));
1017
1018                                 /* Ok, let's get rid of this */
1019                                 log_info("Deleting %s/%s to minimize impact.", j->unit->meta.id, job_type_to_string(j->type));
1020
1021                                 transaction_delete_job(m, j, true);
1022                                 again = true;
1023                                 break;
1024                         }
1025
1026                         if (again)
1027                                 break;
1028                 }
1029
1030         } while (again);
1031 }
1032
1033 static int transaction_apply(Manager *m) {
1034         Iterator i;
1035         Job *j;
1036         int r;
1037
1038         /* Moves the transaction jobs to the set of active jobs */
1039
1040         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1041                 /* Assume merged */
1042                 assert(!j->transaction_prev);
1043                 assert(!j->transaction_next);
1044
1045                 if (j->installed)
1046                         continue;
1047
1048                 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
1049                         goto rollback;
1050         }
1051
1052         while ((j = hashmap_steal_first(m->transaction_jobs))) {
1053                 if (j->installed)
1054                         continue;
1055
1056                 if (j->unit->meta.job)
1057                         job_free(j->unit->meta.job);
1058
1059                 j->unit->meta.job = j;
1060                 j->installed = true;
1061
1062                 /* We're fully installed. Now let's free data we don't
1063                  * need anymore. */
1064
1065                 assert(!j->transaction_next);
1066                 assert(!j->transaction_prev);
1067
1068                 job_add_to_run_queue(j);
1069                 job_add_to_dbus_queue(j);
1070         }
1071
1072         /* As last step, kill all remaining job dependencies. */
1073         transaction_clean_dependencies(m);
1074
1075         return 0;
1076
1077 rollback:
1078
1079         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1080                 if (j->installed)
1081                         continue;
1082
1083                 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
1084         }
1085
1086         return r;
1087 }
1088
1089 static int transaction_activate(Manager *m, JobMode mode, DBusError *e) {
1090         int r;
1091         unsigned generation = 1;
1092
1093         assert(m);
1094
1095         /* This applies the changes recorded in transaction_jobs to
1096          * the actual list of jobs, if possible. */
1097
1098         /* First step: figure out which jobs matter */
1099         transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
1100
1101         /* Second step: Try not to stop any running services if
1102          * we don't have to. Don't try to reverse running
1103          * jobs if we don't have to. */
1104         transaction_minimize_impact(m);
1105
1106         /* Third step: Drop redundant jobs */
1107         transaction_drop_redundant(m);
1108
1109         for (;;) {
1110                 /* Fourth step: Let's remove unneeded jobs that might
1111                  * be lurking. */
1112                 transaction_collect_garbage(m);
1113
1114                 /* Fifth step: verify order makes sense and correct
1115                  * cycles if necessary and possible */
1116                 if ((r = transaction_verify_order(m, &generation, e)) >= 0)
1117                         break;
1118
1119                 if (r != -EAGAIN) {
1120                         log_warning("Requested transaction contains an unfixable cyclic ordering dependency: %s", bus_error(e, r));
1121                         goto rollback;
1122                 }
1123
1124                 /* Let's see if the resulting transaction ordering
1125                  * graph is still cyclic... */
1126         }
1127
1128         for (;;) {
1129                 /* Sixth step: let's drop unmergeable entries if
1130                  * necessary and possible, merge entries we can
1131                  * merge */
1132                 if ((r = transaction_merge_jobs(m, e)) >= 0)
1133                         break;
1134
1135                 if (r != -EAGAIN) {
1136                         log_warning("Requested transaction contains unmergable jobs: %s", bus_error(e, r));
1137                         goto rollback;
1138                 }
1139
1140                 /* Seventh step: an entry got dropped, let's garbage
1141                  * collect its dependencies. */
1142                 transaction_collect_garbage(m);
1143
1144                 /* Let's see if the resulting transaction still has
1145                  * unmergeable entries ... */
1146         }
1147
1148         /* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */
1149         transaction_drop_redundant(m);
1150
1151         /* Ninth step: check whether we can actually apply this */
1152         if (mode == JOB_FAIL)
1153                 if ((r = transaction_is_destructive(m, e)) < 0) {
1154                         log_notice("Requested transaction contradicts existing jobs: %s", bus_error(e, r));
1155                         goto rollback;
1156                 }
1157
1158         /* Tenth step: apply changes */
1159         if ((r = transaction_apply(m)) < 0) {
1160                 log_warning("Failed to apply transaction: %s", strerror(-r));
1161                 goto rollback;
1162         }
1163
1164         assert(hashmap_isempty(m->transaction_jobs));
1165         assert(!m->transaction_anchor);
1166
1167         return 0;
1168
1169 rollback:
1170         transaction_abort(m);
1171         return r;
1172 }
1173
1174 static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool override, bool *is_new) {
1175         Job *j, *f;
1176         int r;
1177
1178         assert(m);
1179         assert(unit);
1180
1181         /* Looks for an axisting prospective job and returns that. If
1182          * it doesn't exist it is created and added to the prospective
1183          * jobs list. */
1184
1185         f = hashmap_get(m->transaction_jobs, unit);
1186
1187         LIST_FOREACH(transaction, j, f) {
1188                 assert(j->unit == unit);
1189
1190                 if (j->type == type) {
1191                         if (is_new)
1192                                 *is_new = false;
1193                         return j;
1194                 }
1195         }
1196
1197         if (unit->meta.job && unit->meta.job->type == type)
1198                 j = unit->meta.job;
1199         else if (!(j = job_new(m, type, unit)))
1200                 return NULL;
1201
1202         j->generation = 0;
1203         j->marker = NULL;
1204         j->matters_to_anchor = false;
1205         j->override = override;
1206
1207         LIST_PREPEND(Job, transaction, f, j);
1208
1209         if ((r = hashmap_replace(m->transaction_jobs, unit, f)) < 0) {
1210                 job_free(j);
1211                 return NULL;
1212         }
1213
1214         if (is_new)
1215                 *is_new = true;
1216
1217         log_debug("Added job %s/%s to transaction.", unit->meta.id, job_type_to_string(type));
1218
1219         return j;
1220 }
1221
1222 void manager_transaction_unlink_job(Manager *m, Job *j, bool delete_dependencies) {
1223         assert(m);
1224         assert(j);
1225
1226         if (j->transaction_prev)
1227                 j->transaction_prev->transaction_next = j->transaction_next;
1228         else if (j->transaction_next)
1229                 hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
1230         else
1231                 hashmap_remove_value(m->transaction_jobs, j->unit, j);
1232
1233         if (j->transaction_next)
1234                 j->transaction_next->transaction_prev = j->transaction_prev;
1235
1236         j->transaction_prev = j->transaction_next = NULL;
1237
1238         while (j->subject_list)
1239                 job_dependency_free(j->subject_list);
1240
1241         while (j->object_list) {
1242                 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
1243
1244                 job_dependency_free(j->object_list);
1245
1246                 if (other && delete_dependencies) {
1247                         log_info("Deleting job %s/%s as dependency of job %s/%s",
1248                                   other->unit->meta.id, job_type_to_string(other->type),
1249                                   j->unit->meta.id, job_type_to_string(j->type));
1250                         transaction_delete_job(m, other, delete_dependencies);
1251                 }
1252         }
1253 }
1254
1255 static int transaction_add_job_and_dependencies(
1256                 Manager *m,
1257                 JobType type,
1258                 Unit *unit,
1259                 Job *by,
1260                 bool matters,
1261                 bool override,
1262                 DBusError *e,
1263                 Job **_ret) {
1264         Job *ret;
1265         Iterator i;
1266         Unit *dep;
1267         int r;
1268         bool is_new;
1269
1270         assert(m);
1271         assert(type < _JOB_TYPE_MAX);
1272         assert(unit);
1273
1274         if (unit->meta.load_state != UNIT_LOADED) {
1275                 dbus_set_error(e, BUS_ERROR_LOAD_FAILED, "Unit %s failed to load. See logs for details.", unit->meta.id);
1276                 return -EINVAL;
1277         }
1278
1279         if (!unit_job_is_applicable(unit, type)) {
1280                 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);
1281                 return -EBADR;
1282         }
1283
1284         /* First add the job. */
1285         if (!(ret = transaction_add_one_job(m, type, unit, override, &is_new)))
1286                 return -ENOMEM;
1287
1288         /* Then, add a link to the job. */
1289         if (!job_dependency_new(by, ret, matters))
1290                 return -ENOMEM;
1291
1292         if (is_new) {
1293                 /* Finally, recursively add in all dependencies. */
1294                 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
1295                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
1296                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, override, e, NULL)) < 0 && r != -EBADR)
1297                                         goto fail;
1298
1299                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
1300                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !override, override, e, NULL)) < 0 && r != -EBADR)
1301                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
1302
1303                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
1304                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, false, e, NULL)) < 0)
1305                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
1306
1307                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
1308                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, override, e, NULL)) < 0 && r != -EBADR)
1309                                         goto fail;
1310
1311                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE_OVERRIDABLE], i)
1312                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !override, override, e, NULL)) < 0 && r != -EBADR)
1313                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
1314
1315                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
1316                                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, override, e, NULL)) < 0 && r != -EBADR)
1317                                         goto fail;
1318
1319                 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
1320
1321                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
1322                                 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, override, e, NULL)) < 0 && r != -EBADR)
1323                                         goto fail;
1324                 }
1325
1326                 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
1327         }
1328
1329         if (_ret)
1330                 *_ret = ret;
1331
1332         return 0;
1333
1334 fail:
1335         return r;
1336 }
1337
1338 static int transaction_add_isolate_jobs(Manager *m) {
1339         Iterator i;
1340         Unit *u;
1341         char *k;
1342         int r;
1343
1344         assert(m);
1345
1346         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
1347
1348                 /* ignore aliases */
1349                 if (u->meta.id != k)
1350                         continue;
1351
1352                 if (UNIT_VTABLE(u)->no_isolate)
1353                         continue;
1354
1355                 /* No need to stop inactive jobs */
1356                 if (UNIT_IS_INACTIVE_OR_MAINTENANCE(unit_active_state(u)))
1357                         continue;
1358
1359                 /* Is there already something listed for this? */
1360                 if (hashmap_get(m->transaction_jobs, u))
1361                         continue;
1362
1363                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, u, NULL, true, false, NULL, NULL)) < 0)
1364                         log_warning("Cannot add isolate job for unit %s, ignoring: %s", u->meta.id, strerror(-r));
1365         }
1366
1367         return 0;
1368 }
1369
1370 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool override, DBusError *e, Job **_ret) {
1371         int r;
1372         Job *ret;
1373
1374         assert(m);
1375         assert(type < _JOB_TYPE_MAX);
1376         assert(unit);
1377         assert(mode < _JOB_MODE_MAX);
1378
1379         if (mode == JOB_ISOLATE && type != JOB_START) {
1380                 dbus_set_error(e, BUS_ERROR_INVALID_JOB_MODE, "Isolate is only valid for start.");
1381                 return -EINVAL;
1382         }
1383
1384         log_debug("Trying to enqueue job %s/%s", unit->meta.id, job_type_to_string(type));
1385
1386         if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, override, e, &ret)) < 0) {
1387                 transaction_abort(m);
1388                 return r;
1389         }
1390
1391         if (mode == JOB_ISOLATE)
1392                 if ((r = transaction_add_isolate_jobs(m)) < 0) {
1393                         transaction_abort(m);
1394                         return r;
1395                 }
1396
1397         if ((r = transaction_activate(m, mode, e)) < 0)
1398                 return r;
1399
1400         log_debug("Enqueued job %s/%s as %u", unit->meta.id, job_type_to_string(type), (unsigned) ret->id);
1401
1402         if (_ret)
1403                 *_ret = ret;
1404
1405         return 0;
1406 }
1407
1408 int manager_add_job_by_name(Manager *m, JobType type, const char *name, JobMode mode, bool override, DBusError *e, Job **_ret) {
1409         Unit *unit;
1410         int r;
1411
1412         assert(m);
1413         assert(type < _JOB_TYPE_MAX);
1414         assert(name);
1415         assert(mode < _JOB_MODE_MAX);
1416
1417         if ((r = manager_load_unit(m, name, NULL, NULL, &unit)) < 0)
1418                 return r;
1419
1420         return manager_add_job(m, type, unit, mode, override, e, _ret);
1421 }
1422
1423 Job *manager_get_job(Manager *m, uint32_t id) {
1424         assert(m);
1425
1426         return hashmap_get(m->jobs, UINT32_TO_PTR(id));
1427 }
1428
1429 Unit *manager_get_unit(Manager *m, const char *name) {
1430         assert(m);
1431         assert(name);
1432
1433         return hashmap_get(m->units, name);
1434 }
1435
1436 unsigned manager_dispatch_load_queue(Manager *m) {
1437         Meta *meta;
1438         unsigned n = 0;
1439
1440         assert(m);
1441
1442         /* Make sure we are not run recursively */
1443         if (m->dispatching_load_queue)
1444                 return 0;
1445
1446         m->dispatching_load_queue = true;
1447
1448         /* Dispatches the load queue. Takes a unit from the queue and
1449          * tries to load its data until the queue is empty */
1450
1451         while ((meta = m->load_queue)) {
1452                 assert(meta->in_load_queue);
1453
1454                 unit_load((Unit*) meta);
1455                 n++;
1456         }
1457
1458         m->dispatching_load_queue = false;
1459         return n;
1460 }
1461
1462 int manager_load_unit_prepare(Manager *m, const char *name, const char *path, DBusError *e, Unit **_ret) {
1463         Unit *ret;
1464         int r;
1465
1466         assert(m);
1467         assert(name || path);
1468
1469         /* This will prepare the unit for loading, but not actually
1470          * load anything from disk. */
1471
1472         if (path && !is_path(path)) {
1473                 dbus_set_error(e, BUS_ERROR_INVALID_PATH, "Path %s is not absolute.", path);
1474                 return -EINVAL;
1475         }
1476
1477         if (!name)
1478                 name = file_name_from_path(path);
1479
1480         if (!unit_name_is_valid(name)) {
1481                 dbus_set_error(e, BUS_ERROR_INVALID_NAME, "Unit name %s is not valid.", name);
1482                 return -EINVAL;
1483         }
1484
1485         if ((ret = manager_get_unit(m, name))) {
1486                 *_ret = ret;
1487                 return 1;
1488         }
1489
1490         if (!(ret = unit_new(m)))
1491                 return -ENOMEM;
1492
1493         if (path)
1494                 if (!(ret->meta.fragment_path = strdup(path))) {
1495                         unit_free(ret);
1496                         return -ENOMEM;
1497                 }
1498
1499         if ((r = unit_add_name(ret, name)) < 0) {
1500                 unit_free(ret);
1501                 return r;
1502         }
1503
1504         unit_add_to_load_queue(ret);
1505         unit_add_to_dbus_queue(ret);
1506         unit_add_to_gc_queue(ret);
1507
1508         if (_ret)
1509                 *_ret = ret;
1510
1511         return 0;
1512 }
1513
1514 int manager_load_unit(Manager *m, const char *name, const char *path, DBusError *e, Unit **_ret) {
1515         int r;
1516
1517         assert(m);
1518
1519         /* This will load the service information files, but not actually
1520          * start any services or anything. */
1521
1522         if ((r = manager_load_unit_prepare(m, name, path, e, _ret)) != 0)
1523                 return r;
1524
1525         manager_dispatch_load_queue(m);
1526
1527         if (_ret)
1528                 *_ret = unit_follow_merge(*_ret);
1529
1530         return 0;
1531 }
1532
1533 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
1534         Iterator i;
1535         Job *j;
1536
1537         assert(s);
1538         assert(f);
1539
1540         HASHMAP_FOREACH(j, s->jobs, i)
1541                 job_dump(j, f, prefix);
1542 }
1543
1544 void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
1545         Iterator i;
1546         Unit *u;
1547         const char *t;
1548
1549         assert(s);
1550         assert(f);
1551
1552         HASHMAP_FOREACH_KEY(u, t, s->units, i)
1553                 if (u->meta.id == t)
1554                         unit_dump(u, f, prefix);
1555 }
1556
1557 void manager_clear_jobs(Manager *m) {
1558         Job *j;
1559
1560         assert(m);
1561
1562         transaction_abort(m);
1563
1564         while ((j = hashmap_first(m->jobs)))
1565                 job_free(j);
1566 }
1567
1568 unsigned manager_dispatch_run_queue(Manager *m) {
1569         Job *j;
1570         unsigned n = 0;
1571
1572         if (m->dispatching_run_queue)
1573                 return 0;
1574
1575         m->dispatching_run_queue = true;
1576
1577         while ((j = m->run_queue)) {
1578                 assert(j->installed);
1579                 assert(j->in_run_queue);
1580
1581                 job_run_and_invalidate(j);
1582                 n++;
1583         }
1584
1585         m->dispatching_run_queue = false;
1586         return n;
1587 }
1588
1589 unsigned manager_dispatch_dbus_queue(Manager *m) {
1590         Job *j;
1591         Meta *meta;
1592         unsigned n = 0;
1593
1594         assert(m);
1595
1596         if (m->dispatching_dbus_queue)
1597                 return 0;
1598
1599         m->dispatching_dbus_queue = true;
1600
1601         while ((meta = m->dbus_unit_queue)) {
1602                 assert(meta->in_dbus_queue);
1603
1604                 bus_unit_send_change_signal((Unit*) meta);
1605                 n++;
1606         }
1607
1608         while ((j = m->dbus_job_queue)) {
1609                 assert(j->in_dbus_queue);
1610
1611                 bus_job_send_change_signal(j);
1612                 n++;
1613         }
1614
1615         m->dispatching_dbus_queue = false;
1616         return n;
1617 }
1618
1619 static int manager_process_notify_fd(Manager *m) {
1620         ssize_t n;
1621
1622         assert(m);
1623
1624         for (;;) {
1625                 char buf[4096];
1626                 struct msghdr msghdr;
1627                 struct iovec iovec;
1628                 struct ucred *ucred;
1629                 union {
1630                         struct cmsghdr cmsghdr;
1631                         uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
1632                 } control;
1633                 Unit *u;
1634                 char **tags;
1635
1636                 zero(iovec);
1637                 iovec.iov_base = buf;
1638                 iovec.iov_len = sizeof(buf)-1;
1639
1640                 zero(control);
1641                 zero(msghdr);
1642                 msghdr.msg_iov = &iovec;
1643                 msghdr.msg_iovlen = 1;
1644                 msghdr.msg_control = &control;
1645                 msghdr.msg_controllen = sizeof(control);
1646
1647                 if ((n = recvmsg(m->notify_watch.fd, &msghdr, MSG_DONTWAIT)) <= 0) {
1648                         if (n >= 0)
1649                                 return -EIO;
1650
1651                         if (errno == EAGAIN)
1652                                 break;
1653
1654                         return -errno;
1655                 }
1656
1657                 if (msghdr.msg_controllen < CMSG_LEN(sizeof(struct ucred)) ||
1658                     control.cmsghdr.cmsg_level != SOL_SOCKET ||
1659                     control.cmsghdr.cmsg_type != SCM_CREDENTIALS ||
1660                     control.cmsghdr.cmsg_len != CMSG_LEN(sizeof(struct ucred))) {
1661                         log_warning("Received notify message without credentials. Ignoring.");
1662                         continue;
1663                 }
1664
1665                 ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
1666
1667                 if (!(u = hashmap_get(m->watch_pids, UINT32_TO_PTR(ucred->pid))))
1668                         if (!(u = cgroup_unit_by_pid(m, ucred->pid))) {
1669                                 log_warning("Cannot find unit for notify message of PID %lu.", (unsigned long) ucred->pid);
1670                                 continue;
1671                         }
1672
1673                 assert((size_t) n < sizeof(buf));
1674                 buf[n] = 0;
1675                 if (!(tags = strv_split(buf, "\n\r")))
1676                         return -ENOMEM;
1677
1678                 log_debug("Got notification message for unit %s", u->meta.id);
1679
1680                 if (UNIT_VTABLE(u)->notify_message)
1681                         UNIT_VTABLE(u)->notify_message(u, ucred->pid, tags);
1682
1683                 strv_free(tags);
1684         }
1685
1686         return 0;
1687 }
1688
1689 static int manager_dispatch_sigchld(Manager *m) {
1690         assert(m);
1691
1692         for (;;) {
1693                 siginfo_t si;
1694                 Unit *u;
1695                 int r;
1696
1697                 zero(si);
1698
1699                 /* First we call waitd() for a PID and do not reap the
1700                  * zombie. That way we can still access /proc/$PID for
1701                  * it while it is a zombie. */
1702                 if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG|WNOWAIT) < 0) {
1703
1704                         if (errno == ECHILD)
1705                                 break;
1706
1707                         if (errno == EINTR)
1708                                 continue;
1709
1710                         return -errno;
1711                 }
1712
1713                 if (si.si_pid <= 0)
1714                         break;
1715
1716                 if (si.si_code == CLD_EXITED || si.si_code == CLD_KILLED || si.si_code == CLD_DUMPED) {
1717                         char *name = NULL;
1718
1719                         get_process_name(si.si_pid, &name);
1720                         log_debug("Got SIGCHLD for process %lu (%s)", (unsigned long) si.si_pid, strna(name));
1721                         free(name);
1722                 }
1723
1724                 /* Let's flush any message the dying child might still
1725                  * have queued for us. This ensures that the process
1726                  * still exists in /proc so that we can figure out
1727                  * which cgroup and hence unit it belongs to. */
1728                 if ((r = manager_process_notify_fd(m)) < 0)
1729                         return r;
1730
1731                 /* And now figure out the unit this belongs to */
1732                 if (!(u = hashmap_get(m->watch_pids, UINT32_TO_PTR(si.si_pid))))
1733                         u = cgroup_unit_by_pid(m, si.si_pid);
1734
1735                 /* And now, we actually reap the zombie. */
1736                 if (waitid(P_PID, si.si_pid, &si, WEXITED) < 0) {
1737                         if (errno == EINTR)
1738                                 continue;
1739
1740                         return -errno;
1741                 }
1742
1743                 if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
1744                         continue;
1745
1746                 log_debug("Child %lu died (code=%s, status=%i/%s)",
1747                           (long unsigned) si.si_pid,
1748                           sigchld_code_to_string(si.si_code),
1749                           si.si_status,
1750                           strna(si.si_code == CLD_EXITED ? exit_status_to_string(si.si_status) : signal_to_string(si.si_status)));
1751
1752                 if (!u)
1753                         continue;
1754
1755                 log_debug("Child %llu belongs to %s", (long long unsigned) si.si_pid, u->meta.id);
1756
1757                 hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid));
1758                 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
1759         }
1760
1761         return 0;
1762 }
1763
1764 static int manager_start_target(Manager *m, const char *name, JobMode mode) {
1765         int r;
1766         DBusError error;
1767
1768         dbus_error_init(&error);
1769
1770         log_info("Activating special unit %s", name);
1771
1772         if ((r = manager_add_job_by_name(m, JOB_START, name, mode, true, &error, NULL)) < 0)
1773                 log_error("Failed to enqueue %s job: %s", name, bus_error(&error, r));
1774
1775         dbus_error_free(&error);
1776
1777         return r;
1778 }
1779
1780 static int manager_process_signal_fd(Manager *m) {
1781         ssize_t n;
1782         struct signalfd_siginfo sfsi;
1783         bool sigchld = false;
1784
1785         assert(m);
1786
1787         for (;;) {
1788                 if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
1789
1790                         if (n >= 0)
1791                                 return -EIO;
1792
1793                         if (errno == EAGAIN)
1794                                 break;
1795
1796                         return -errno;
1797                 }
1798
1799                 log_debug("Received SIG%s", strna(signal_to_string(sfsi.ssi_signo)));
1800
1801                 switch (sfsi.ssi_signo) {
1802
1803                 case SIGCHLD:
1804                         sigchld = true;
1805                         break;
1806
1807                 case SIGTERM:
1808                         if (m->running_as == MANAGER_SYSTEM) {
1809                                 /* This is for compatibility with the
1810                                  * original sysvinit */
1811                                 m->exit_code = MANAGER_REEXECUTE;
1812                                 break;
1813                         }
1814
1815                         /* Fall through */
1816
1817                 case SIGINT:
1818                         if (m->running_as == MANAGER_SYSTEM) {
1819                                 manager_start_target(m, SPECIAL_CTRL_ALT_DEL_TARGET, JOB_REPLACE);
1820                                 break;
1821                         }
1822
1823                         /* Run the exit target if there is one, if not, just exit. */
1824                         if (manager_start_target(m, SPECIAL_EXIT_SERVICE, JOB_REPLACE) < 0) {
1825                                 m->exit_code = MANAGER_EXIT;
1826                                 return 0;
1827                         }
1828
1829                         break;
1830
1831                 case SIGWINCH:
1832                         if (m->running_as == MANAGER_SYSTEM)
1833                                 manager_start_target(m, SPECIAL_KBREQUEST_TARGET, JOB_REPLACE);
1834
1835                         /* This is a nop on non-init */
1836                         break;
1837
1838                 case SIGPWR:
1839                         if (m->running_as == MANAGER_SYSTEM)
1840                                 manager_start_target(m, SPECIAL_SIGPWR_TARGET, JOB_REPLACE);
1841
1842                         /* This is a nop on non-init */
1843                         break;
1844
1845                 case SIGUSR1: {
1846                         Unit *u;
1847
1848                         u = manager_get_unit(m, SPECIAL_DBUS_SERVICE);
1849
1850                         if (!u || UNIT_IS_ACTIVE_OR_RELOADING(unit_active_state(u))) {
1851                                 log_info("Trying to reconnect to bus...");
1852                                 bus_init(m);
1853                         }
1854
1855                         if (!u || !UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u))) {
1856                                 log_info("Loading D-Bus service...");
1857                                 manager_start_target(m, SPECIAL_DBUS_SERVICE, JOB_REPLACE);
1858                         }
1859
1860                         break;
1861                 }
1862
1863                 case SIGUSR2: {
1864                         FILE *f;
1865                         char *dump = NULL;
1866                         size_t size;
1867
1868                         if (!(f = open_memstream(&dump, &size))) {
1869                                 log_warning("Failed to allocate memory stream.");
1870                                 break;
1871                         }
1872
1873                         manager_dump_units(m, f, "\t");
1874                         manager_dump_jobs(m, f, "\t");
1875
1876                         if (ferror(f)) {
1877                                 fclose(f);
1878                                 free(dump);
1879                                 log_warning("Failed to write status stream");
1880                                 break;
1881                         }
1882
1883                         fclose(f);
1884                         log_dump(LOG_INFO, dump);
1885                         free(dump);
1886
1887                         break;
1888                 }
1889
1890                 case SIGHUP:
1891                         m->exit_code = MANAGER_RELOAD;
1892                         break;
1893
1894                 default: {
1895                         static const char * const table[] = {
1896                                 [0] = SPECIAL_DEFAULT_TARGET,
1897                                 [1] = SPECIAL_RESCUE_TARGET,
1898                                 [2] = SPECIAL_EMERGENCY_SERVICE,
1899                                 [3] = SPECIAL_HALT_TARGET,
1900                                 [4] = SPECIAL_POWEROFF_TARGET,
1901                                 [5] = SPECIAL_REBOOT_TARGET
1902                         };
1903
1904                         if ((int) sfsi.ssi_signo >= SIGRTMIN+0 &&
1905                             (int) sfsi.ssi_signo < SIGRTMIN+(int) ELEMENTSOF(table)) {
1906                                 manager_start_target(m, table[sfsi.ssi_signo - SIGRTMIN],
1907                                                      (sfsi.ssi_signo == 1 || sfsi.ssi_signo == 2) ? JOB_ISOLATE : JOB_REPLACE);
1908                                 break;
1909                         }
1910
1911                         log_warning("Got unhandled signal <%s>.", strna(signal_to_string(sfsi.ssi_signo)));
1912                 }
1913                 }
1914         }
1915
1916         if (sigchld)
1917                 return manager_dispatch_sigchld(m);
1918
1919         return 0;
1920 }
1921
1922 static int process_event(Manager *m, struct epoll_event *ev) {
1923         int r;
1924         Watch *w;
1925
1926         assert(m);
1927         assert(ev);
1928
1929         assert(w = ev->data.ptr);
1930
1931         switch (w->type) {
1932
1933         case WATCH_SIGNAL:
1934
1935                 /* An incoming signal? */
1936                 if (ev->events != EPOLLIN)
1937                         return -EINVAL;
1938
1939                 if ((r = manager_process_signal_fd(m)) < 0)
1940                         return r;
1941
1942                 break;
1943
1944         case WATCH_NOTIFY:
1945
1946                 /* An incoming daemon notification event? */
1947                 if (ev->events != EPOLLIN)
1948                         return -EINVAL;
1949
1950                 if ((r = manager_process_notify_fd(m)) < 0)
1951                         return r;
1952
1953                 break;
1954
1955         case WATCH_FD:
1956
1957                 /* Some fd event, to be dispatched to the units */
1958                 UNIT_VTABLE(w->data.unit)->fd_event(w->data.unit, w->fd, ev->events, w);
1959                 break;
1960
1961         case WATCH_TIMER: {
1962                 uint64_t v;
1963                 ssize_t k;
1964
1965                 /* Some timer event, to be dispatched to the units */
1966                 if ((k = read(w->fd, &v, sizeof(v))) != sizeof(v)) {
1967
1968                         if (k < 0 && (errno == EINTR || errno == EAGAIN))
1969                                 break;
1970
1971                         return k < 0 ? -errno : -EIO;
1972                 }
1973
1974                 UNIT_VTABLE(w->data.unit)->timer_event(w->data.unit, v, w);
1975                 break;
1976         }
1977
1978         case WATCH_MOUNT:
1979                 /* Some mount table change, intended for the mount subsystem */
1980                 mount_fd_event(m, ev->events);
1981                 break;
1982
1983         case WATCH_UDEV:
1984                 /* Some notification from udev, intended for the device subsystem */
1985                 device_fd_event(m, ev->events);
1986                 break;
1987
1988         case WATCH_DBUS_WATCH:
1989                 bus_watch_event(m, w, ev->events);
1990                 break;
1991
1992         case WATCH_DBUS_TIMEOUT:
1993                 bus_timeout_event(m, w, ev->events);
1994                 break;
1995
1996         default:
1997                 assert_not_reached("Unknown epoll event type.");
1998         }
1999
2000         return 0;
2001 }
2002
2003 int manager_loop(Manager *m) {
2004         int r;
2005
2006         RATELIMIT_DEFINE(rl, 1*USEC_PER_SEC, 1000);
2007
2008         assert(m);
2009         m->exit_code = MANAGER_RUNNING;
2010
2011         /* There might still be some zombies hanging around from
2012          * before we were exec()'ed. Leat's reap them */
2013         if ((r = manager_dispatch_sigchld(m)) < 0)
2014                 return r;
2015
2016         while (m->exit_code == MANAGER_RUNNING) {
2017                 struct epoll_event event;
2018                 int n;
2019
2020                 if (!ratelimit_test(&rl)) {
2021                         /* Yay, something is going seriously wrong, pause a little */
2022                         log_warning("Looping too fast. Throttling execution a little.");
2023                         sleep(1);
2024                 }
2025
2026                 if (manager_dispatch_load_queue(m) > 0)
2027                         continue;
2028
2029                 if (manager_dispatch_run_queue(m) > 0)
2030                         continue;
2031
2032                 if (bus_dispatch(m) > 0)
2033                         continue;
2034
2035                 if (manager_dispatch_cleanup_queue(m) > 0)
2036                         continue;
2037
2038                 if (manager_dispatch_gc_queue(m) > 0)
2039                         continue;
2040
2041                 if (manager_dispatch_dbus_queue(m) > 0)
2042                         continue;
2043
2044                 if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) {
2045
2046                         if (errno == EINTR)
2047                                 continue;
2048
2049                         return -errno;
2050                 }
2051
2052                 assert(n == 1);
2053
2054                 if ((r = process_event(m, &event)) < 0)
2055                         return r;
2056         }
2057
2058         return m->exit_code;
2059 }
2060
2061 int manager_get_unit_from_dbus_path(Manager *m, const char *s, Unit **_u) {
2062         char *n;
2063         Unit *u;
2064
2065         assert(m);
2066         assert(s);
2067         assert(_u);
2068
2069         if (!startswith(s, "/org/freedesktop/systemd1/unit/"))
2070                 return -EINVAL;
2071
2072         if (!(n = bus_path_unescape(s+31)))
2073                 return -ENOMEM;
2074
2075         u = manager_get_unit(m, n);
2076         free(n);
2077
2078         if (!u)
2079                 return -ENOENT;
2080
2081         *_u = u;
2082
2083         return 0;
2084 }
2085
2086 int manager_get_job_from_dbus_path(Manager *m, const char *s, Job **_j) {
2087         Job *j;
2088         unsigned id;
2089         int r;
2090
2091         assert(m);
2092         assert(s);
2093         assert(_j);
2094
2095         if (!startswith(s, "/org/freedesktop/systemd1/job/"))
2096                 return -EINVAL;
2097
2098         if ((r = safe_atou(s + 30, &id)) < 0)
2099                 return r;
2100
2101         if (!(j = manager_get_job(m, id)))
2102                 return -ENOENT;
2103
2104         *_j = j;
2105
2106         return 0;
2107 }
2108
2109 static bool manager_utmp_good(Manager *m) {
2110         int r;
2111
2112         assert(m);
2113
2114         if ((r = mount_path_is_mounted(m, _PATH_UTMPX)) <= 0) {
2115
2116                 if (r < 0)
2117                         log_warning("Failed to determine whether " _PATH_UTMPX " is mounted: %s", strerror(-r));
2118
2119                 return false;
2120         }
2121
2122         return true;
2123 }
2124
2125 void manager_write_utmp_reboot(Manager *m) {
2126         int r;
2127
2128         assert(m);
2129
2130         if (m->utmp_reboot_written)
2131                 return;
2132
2133         if (m->running_as != MANAGER_SYSTEM)
2134                 return;
2135
2136         if (!manager_utmp_good(m))
2137                 return;
2138
2139         if ((r = utmp_put_reboot(m->startup_timestamp.realtime)) < 0) {
2140
2141                 if (r != -ENOENT && r != -EROFS)
2142                         log_warning("Failed to write utmp/wtmp: %s", strerror(-r));
2143
2144                 return;
2145         }
2146
2147         m->utmp_reboot_written = true;
2148 }
2149
2150 void manager_write_utmp_runlevel(Manager *m, Unit *u) {
2151         int runlevel, r;
2152
2153         assert(m);
2154         assert(u);
2155
2156         if (u->meta.type != UNIT_TARGET)
2157                 return;
2158
2159         if (m->running_as != MANAGER_SYSTEM)
2160                 return;
2161
2162         if (!manager_utmp_good(m))
2163                 return;
2164
2165         if ((runlevel = target_get_runlevel(TARGET(u))) <= 0)
2166                 return;
2167
2168         if ((r = utmp_put_runlevel(0, runlevel, 0)) < 0) {
2169
2170                 if (r != -ENOENT && r != -EROFS)
2171                         log_warning("Failed to write utmp/wtmp: %s", strerror(-r));
2172         }
2173 }
2174
2175 void manager_dispatch_bus_name_owner_changed(
2176                 Manager *m,
2177                 const char *name,
2178                 const char* old_owner,
2179                 const char *new_owner) {
2180
2181         Unit *u;
2182
2183         assert(m);
2184         assert(name);
2185
2186         if (!(u = hashmap_get(m->watch_bus, name)))
2187                 return;
2188
2189         UNIT_VTABLE(u)->bus_name_owner_change(u, name, old_owner, new_owner);
2190 }
2191
2192 void manager_dispatch_bus_query_pid_done(
2193                 Manager *m,
2194                 const char *name,
2195                 pid_t pid) {
2196
2197         Unit *u;
2198
2199         assert(m);
2200         assert(name);
2201         assert(pid >= 1);
2202
2203         if (!(u = hashmap_get(m->watch_bus, name)))
2204                 return;
2205
2206         UNIT_VTABLE(u)->bus_query_pid_done(u, name, pid);
2207 }
2208
2209 int manager_open_serialization(FILE **_f) {
2210         char *path;
2211         mode_t saved_umask;
2212         int fd;
2213         FILE *f;
2214
2215         assert(_f);
2216
2217         if (asprintf(&path, "/dev/shm/systemd-%u.dump-XXXXXX", (unsigned) getpid()) < 0)
2218                 return -ENOMEM;
2219
2220         saved_umask = umask(0077);
2221         fd = mkostemp(path, O_RDWR|O_CLOEXEC);
2222         umask(saved_umask);
2223
2224         if (fd < 0) {
2225                 free(path);
2226                 return -errno;
2227         }
2228
2229         unlink(path);
2230
2231         log_debug("Serializing state to %s", path);
2232         free(path);
2233
2234         if (!(f = fdopen(fd, "w+")) < 0)
2235                 return -errno;
2236
2237         *_f = f;
2238
2239         return 0;
2240 }
2241
2242 int manager_serialize(Manager *m, FILE *f, FDSet *fds) {
2243         Iterator i;
2244         Unit *u;
2245         const char *t;
2246         int r;
2247
2248         assert(m);
2249         assert(f);
2250         assert(fds);
2251
2252         HASHMAP_FOREACH_KEY(u, t, m->units, i) {
2253                 if (u->meta.id != t)
2254                         continue;
2255
2256                 if (!unit_can_serialize(u))
2257                         continue;
2258
2259                 /* Start marker */
2260                 fputs(u->meta.id, f);
2261                 fputc('\n', f);
2262
2263                 if ((r = unit_serialize(u, f, fds)) < 0)
2264                         return r;
2265         }
2266
2267         if (ferror(f))
2268                 return -EIO;
2269
2270         return 0;
2271 }
2272
2273 int manager_deserialize(Manager *m, FILE *f, FDSet *fds) {
2274         int r = 0;
2275
2276         assert(m);
2277         assert(f);
2278
2279         log_debug("Deserializing state...");
2280
2281         m->deserializing = true;
2282
2283         for (;;) {
2284                 Unit *u;
2285                 char name[UNIT_NAME_MAX+2];
2286
2287                 /* Start marker */
2288                 if (!fgets(name, sizeof(name), f)) {
2289                         if (feof(f))
2290                                 break;
2291
2292                         r = -errno;
2293                         goto finish;
2294                 }
2295
2296                 char_array_0(name);
2297
2298                 if ((r = manager_load_unit(m, strstrip(name), NULL, NULL, &u)) < 0)
2299                         goto finish;
2300
2301                 if ((r = unit_deserialize(u, f, fds)) < 0)
2302                         goto finish;
2303         }
2304
2305         if (ferror(f)) {
2306                 r = -EIO;
2307                 goto finish;
2308         }
2309
2310         r = 0;
2311
2312 finish:
2313         m->deserializing = false;
2314
2315         return r;
2316 }
2317
2318 int manager_reload(Manager *m) {
2319         int r, q;
2320         FILE *f;
2321         FDSet *fds;
2322
2323         assert(m);
2324
2325         if ((r = manager_open_serialization(&f)) < 0)
2326                 return r;
2327
2328         if (!(fds = fdset_new())) {
2329                 r = -ENOMEM;
2330                 goto finish;
2331         }
2332
2333         if ((r = manager_serialize(m, f, fds)) < 0)
2334                 goto finish;
2335
2336         if (fseeko(f, 0, SEEK_SET) < 0) {
2337                 r = -errno;
2338                 goto finish;
2339         }
2340
2341         /* From here on there is no way back. */
2342         manager_clear_jobs_and_units(m);
2343
2344         /* Find new unit paths */
2345         lookup_paths_free(&m->lookup_paths);
2346         if ((q = lookup_paths_init(&m->lookup_paths, m->running_as)) < 0)
2347                 r = q;
2348
2349         /* First, enumerate what we can from all config files */
2350         if ((q = manager_enumerate(m)) < 0)
2351                 r = q;
2352
2353         /* Second, deserialize our stored data */
2354         if ((q = manager_deserialize(m, f, fds)) < 0)
2355                 r = q;
2356
2357         fclose(f);
2358         f = NULL;
2359
2360         /* Third, fire things up! */
2361         if ((q = manager_coldplug(m)) < 0)
2362                 r = q;
2363
2364 finish:
2365         if (f)
2366                 fclose(f);
2367
2368         if (fds)
2369                 fdset_free(fds);
2370
2371         return r;
2372 }
2373
2374 bool manager_is_booting_or_shutting_down(Manager *m) {
2375         Unit *u;
2376
2377         assert(m);
2378
2379         /* Is the initial job still around? */
2380         if (manager_get_job(m, 1))
2381                 return true;
2382
2383         /* Is there a job for the shutdown target? */
2384         if (((u = manager_get_unit(m, SPECIAL_SHUTDOWN_TARGET))))
2385                 return !!u->meta.job;
2386
2387         return false;
2388 }
2389
2390 static const char* const manager_running_as_table[_MANAGER_RUNNING_AS_MAX] = {
2391         [MANAGER_SYSTEM] = "system",
2392         [MANAGER_SESSION] = "session"
2393 };
2394
2395 DEFINE_STRING_TABLE_LOOKUP(manager_running_as, ManagerRunningAs);