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_family_t) + 1 + strlen(sa.un.sun_path+1)) < 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         /* If we will deserialize make sure that during enumeration
 548          * this is already known, so we increase the counter here
 549          * already */
 550         if (serialization)
 551                 m->n_deserializing ++;
 552
 553         /* First, enumerate what we can from all config files */
 554         r = manager_enumerate(m);
 555
 556         /* Second, deserialize if there is something to deserialize */
 557         if (serialization)
 558                 if ((q = manager_deserialize(m, serialization, fds)) < 0)
 559                         r = q;
 560
 561         /* Third, fire things up! */
 562         if ((q = manager_coldplug(m)) < 0)
 563                 r = q;
 564
 565         if (serialization) {
 566                 assert(m->n_deserializing > 0);
 567                 m->n_deserializing --;
 568         }
 569
 570         /* Now that the initial devices are available, let's see if we
 571          * can write the utmp file */
 572         manager_write_utmp_reboot(m);
 573
 574         return r;
 575 }
 576
 577 static void transaction_delete_job(Manager *m, Job *j, bool delete_dependencies) {
 578         assert(m);
 579         assert(j);
 580
 581         /* Deletes one job from the transaction */
 582
 583         manager_transaction_unlink_job(m, j, delete_dependencies);
 584
 585         if (!j->installed)
 586                 job_free(j);
 587 }
 588
 589 static void transaction_delete_unit(Manager *m, Unit *u) {
 590         Job *j;
 591
 592         /* Deletes all jobs associated with a certain unit from the
 593          * transaction */
 594
 595         while ((j = hashmap_get(m->transaction_jobs, u)))
 596                 transaction_delete_job(m, j, true);
 597 }
 598
 599 static void transaction_clean_dependencies(Manager *m) {
 600         Iterator i;
 601         Job *j;
 602
 603         assert(m);
 604
 605         /* Drops all dependencies of all installed jobs */
 606
 607         HASHMAP_FOREACH(j, m->jobs, i) {
 608                 while (j->subject_list)
 609                         job_dependency_free(j->subject_list);
 610                 while (j->object_list)
 611                         job_dependency_free(j->object_list);
 612         }
 613
 614         assert(!m->transaction_anchor);
 615 }
 616
 617 static void transaction_abort(Manager *m) {
 618         Job *j;
 619
 620         assert(m);
 621
 622         while ((j = hashmap_first(m->transaction_jobs)))
 623                 if (j->installed)
 624                         transaction_delete_job(m, j, true);
 625                 else
 626                         job_free(j);
 627
 628         assert(hashmap_isempty(m->transaction_jobs));
 629
 630         transaction_clean_dependencies(m);
 631 }
 632
 633 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
 634         JobDependency *l;
 635
 636         assert(m);
 637
 638         /* A recursive sweep through the graph that marks all units
 639          * that matter to the anchor job, i.e. are directly or
 640          * indirectly a dependency of the anchor job via paths that
 641          * are fully marked as mattering. */
 642
 643         if (j)
 644                 l = j->subject_list;
 645         else
 646                 l = m->transaction_anchor;
 647
 648         LIST_FOREACH(subject, l, l) {
 649
 650                 /* This link does not matter */
 651                 if (!l->matters)
 652                         continue;
 653
 654                 /* This unit has already been marked */
 655                 if (l->object->generation == generation)
 656                         continue;
 657
 658                 l->object->matters_to_anchor = true;
 659                 l->object->generation = generation;
 660
 661                 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
 662         }
 663 }
 664
 665 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
 666         JobDependency *l, *last;
 667
 668         assert(j);
 669         assert(other);
 670         assert(j->unit == other->unit);
 671         assert(!j->installed);
 672
 673         /* Merges 'other' into 'j' and then deletes j. */
 674
 675         j->type = t;
 676         j->state = JOB_WAITING;
 677         j->override = j->override || other->override;
 678
 679         j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
 680
 681         /* Patch us in as new owner of the JobDependency objects */
 682         last = NULL;
 683         LIST_FOREACH(subject, l, other->subject_list) {
 684                 assert(l->subject == other);
 685                 l->subject = j;
 686                 last = l;
 687         }
 688
 689         /* Merge both lists */
 690         if (last) {
 691                 last->subject_next = j->subject_list;
 692                 if (j->subject_list)
 693                         j->subject_list->subject_prev = last;
 694                 j->subject_list = other->subject_list;
 695         }
 696
 697         /* Patch us in as new owner of the JobDependency objects */
 698         last = NULL;
 699         LIST_FOREACH(object, l, other->object_list) {
 700                 assert(l->object == other);
 701                 l->object = j;
 702                 last = l;
 703         }
 704
 705         /* Merge both lists */
 706         if (last) {
 707                 last->object_next = j->object_list;
 708                 if (j->object_list)
 709                         j->object_list->object_prev = last;
 710                 j->object_list = other->object_list;
 711         }
 712
 713         /* Kill the other job */
 714         other->subject_list = NULL;
 715         other->object_list = NULL;
 716         transaction_delete_job(m, other, true);
 717 }
 718 static bool job_is_conflicted_by(Job *j) {
 719         JobDependency *l;
 720
 721         assert(j);
 722
 723         /* Returns true if this job is pulled in by a least one
 724          * ConflictedBy dependency. */
 725
 726         LIST_FOREACH(object, l, j->object_list)
 727                 if (l->conflicts)
 728                         return true;
 729
 730         return false;
 731 }
 732
 733 static int delete_one_unmergeable_job(Manager *m, Job *j) {
 734         Job *k;
 735
 736         assert(j);
 737
 738         /* Tries to delete one item in the linked list
 739          * j->transaction_next->transaction_next->... that conflicts
 740          * whith another one, in an attempt to make an inconsistent
 741          * transaction work. */
 742
 743         /* We rely here on the fact that if a merged with b does not
 744          * merge with c, either a or b merge with c neither */
 745         LIST_FOREACH(transaction, j, j)
 746                 LIST_FOREACH(transaction, k, j->transaction_next) {
 747                         Job *d;
 748
 749                         /* Is this one mergeable? Then skip it */
 750                         if (job_type_is_mergeable(j->type, k->type))
 751                                 continue;
 752
 753                         /* Ok, we found two that conflict, let's see if we can
 754                          * drop one of them */
 755                         if (!j->matters_to_anchor && !k->matters_to_anchor) {
 756
 757                                 /* Both jobs don't matter, so let's
 758                                  * find the one that is smarter to
 759                                  * remove. Let's think positive and
 760                                  * rather remove stops then starts --
 761                                  * except if something is being
 762                                  * stopped because it is conflicted by
 763                                  * another unit in which case we
 764                                  * rather remove the start. */
 765
 766                                 log_debug("Looking at job %s/%s conflicted_by=%s", j->unit->meta.id, job_type_to_string(j->type), yes_no(j->type == JOB_STOP && job_is_conflicted_by(j)));
 767                                 log_debug("Looking at job %s/%s conflicted_by=%s", k->unit->meta.id, job_type_to_string(k->type), yes_no(k->type == JOB_STOP && job_is_conflicted_by(k)));
 768
 769                                 if (j->type == JOB_STOP) {
 770
 771                                         if (job_is_conflicted_by(j))
 772                                                 d = k;
 773                                         else
 774                                                 d = j;
 775
 776                                 } else if (k->type == JOB_STOP) {
 777
 778                                         if (job_is_conflicted_by(k))
 779                                                 d = j;
 780                                         else
 781                                                 d = k;
 782                                 }
 783
 784                         } else if (!j->matters_to_anchor)
 785                                 d = j;
 786                         else if (!k->matters_to_anchor)
 787                                 d = k;
 788                         else
 789                                 return -ENOEXEC;
 790
 791                         /* Ok, we can drop one, so let's do so. */
 792                         log_debug("Fixing conflicting jobs by deleting job %s/%s", d->unit->meta.id, job_type_to_string(d->type));
 793                         transaction_delete_job(m, d, true);
 794                         return 0;
 795                 }
 796
 797         return -EINVAL;
 798 }
 799
 800 static int transaction_merge_jobs(Manager *m, DBusError *e) {
 801         Job *j;
 802         Iterator i;
 803         int r;
 804
 805         assert(m);
 806
 807         /* First step, check whether any of the jobs for one specific
 808          * task conflict. If so, try to drop one of them. */
 809         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 810                 JobType t;
 811                 Job *k;
 812
 813                 t = j->type;
 814                 LIST_FOREACH(transaction, k, j->transaction_next) {
 815                         if ((r = job_type_merge(&t, k->type)) >= 0)
 816                                 continue;
 817
 818                         /* OK, we could not merge all jobs for this
 819                          * action. Let's see if we can get rid of one
 820                          * of them */
 821
 822                         if ((r = delete_one_unmergeable_job(m, j)) >= 0)
 823                                 /* Ok, we managed to drop one, now
 824                                  * let's ask our callers to call us
 825                                  * again after garbage collecting */
 826                                 return -EAGAIN;
 827
 828                         /* We couldn't merge anything. Failure */
 829                         dbus_set_error(e, BUS_ERROR_TRANSACTION_JOBS_CONFLICTING, "Transaction contains conflicting jobs '%s' and '%s' for %s. Probably contradicting requirement dependencies configured.",
 830                                        job_type_to_string(t), job_type_to_string(k->type), k->unit->meta.id);
 831                         return r;
 832                 }
 833         }
 834
 835         /* Second step, merge the jobs. */
 836         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 837                 JobType t = j->type;
 838                 Job *k;
 839
 840                 /* Merge all transactions */
 841                 LIST_FOREACH(transaction, k, j->transaction_next)
 842                         assert_se(job_type_merge(&t, k->type) == 0);
 843
 844                 /* If an active job is mergeable, merge it too */
 845                 if (j->unit->meta.job)
 846                         job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
 847
 848                 while ((k = j->transaction_next)) {
 849                         if (j->installed) {
 850                                 transaction_merge_and_delete_job(m, k, j, t);
 851                                 j = k;
 852                         } else
 853                                 transaction_merge_and_delete_job(m, j, k, t);
 854                 }
 855
 856                 assert(!j->transaction_next);
 857                 assert(!j->transaction_prev);
 858         }
 859
 860         return 0;
 861 }
 862
 863 static void transaction_drop_redundant(Manager *m) {
 864         bool again;
 865
 866         assert(m);
 867
 868         /* Goes through the transaction and removes all jobs that are
 869          * a noop */
 870
 871         do {
 872                 Job *j;
 873                 Iterator i;
 874
 875                 again = false;
 876
 877                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 878                         bool changes_something = false;
 879                         Job *k;
 880
 881                         LIST_FOREACH(transaction, k, j) {
 882
 883                                 if (!job_is_anchor(k) &&
 884                                     job_type_is_redundant(k->type, unit_active_state(k->unit)))
 885                                         continue;
 886
 887                                 changes_something = true;
 888                                 break;
 889                         }
 890
 891                         if (changes_something)
 892                                 continue;
 893
 894                         log_debug("Found redundant job %s/%s, dropping.", j->unit->meta.id, job_type_to_string(j->type));
 895                         transaction_delete_job(m, j, false);
 896                         again = true;
 897                         break;
 898                 }
 899
 900         } while (again);
 901 }
 902
 903 static bool unit_matters_to_anchor(Unit *u, Job *j) {
 904         assert(u);
 905         assert(!j->transaction_prev);
 906
 907         /* Checks whether at least one of the jobs for this unit
 908          * matters to the anchor. */
 909
 910         LIST_FOREACH(transaction, j, j)
 911                 if (j->matters_to_anchor)
 912                         return true;
 913
 914         return false;
 915 }
 916
 917 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation, DBusError *e) {
 918         Iterator i;
 919         Unit *u;
 920         int r;
 921
 922         assert(m);
 923         assert(j);
 924         assert(!j->transaction_prev);
 925
 926         /* Does a recursive sweep through the ordering graph, looking
 927          * for a cycle. If we find cycle we try to break it. */
 928
 929         /* Have we seen this before? */
 930         if (j->generation == generation) {
 931                 Job *k, *delete;
 932
 933                 /* If the marker is NULL we have been here already and
 934                  * decided the job was loop-free from here. Hence
 935                  * shortcut things and return right-away. */
 936                 if (!j->marker)
 937                         return 0;
 938
 939                 /* So, the marker is not NULL and we already have been
 940                  * here. We have a cycle. Let's try to break it. We go
 941                  * backwards in our path and try to find a suitable
 942                  * job to remove. We use the marker to find our way
 943                  * back, since smart how we are we stored our way back
 944                  * in there. */
 945                 log_warning("Found ordering cycle on %s/%s", j->unit->meta.id, job_type_to_string(j->type));
 946
 947                 delete = NULL;
 948                 for (k = from; k; k = ((k->generation == generation && k->marker != k) ? k->marker : NULL)) {
 949
 950                         log_info("Walked on cycle path to %s/%s", k->unit->meta.id, job_type_to_string(k->type));
 951
 952                         if (!delete &&
 953                             !k->installed &&
 954                             !unit_matters_to_anchor(k->unit, k)) {
 955                                 /* Ok, we can drop this one, so let's
 956                                  * do so. */
 957                                 delete = k;
 958                         }
 959
 960                         /* Check if this in fact was the beginning of
 961                          * the cycle */
 962                         if (k == j)
 963                                 break;
 964                 }
 965
 966
 967                 if (delete) {
 968                         log_warning("Breaking ordering cycle by deleting job %s/%s", k->unit->meta.id, job_type_to_string(k->type));
 969                         transaction_delete_unit(m, delete->unit);
 970                         return -EAGAIN;
 971                 }
 972
 973                 log_error("Unable to break cycle");
 974
 975                 dbus_set_error(e, BUS_ERROR_TRANSACTION_ORDER_IS_CYCLIC, "Transaction order is cyclic. See logs for details.");
 976                 return -ENOEXEC;
 977         }
 978
 979         /* Make the marker point to where we come from, so that we can
 980          * find our way backwards if we want to break a cycle. We use
 981          * a special marker for the beginning: we point to
 982          * ourselves. */
 983         j->marker = from ? from : j;
 984         j->generation = generation;
 985
 986         /* We assume that the the dependencies are bidirectional, and
 987          * hence can ignore UNIT_AFTER */
 988         SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
 989                 Job *o;
 990
 991                 /* Is there a job for this unit? */
 992                 if (!(o = hashmap_get(m->transaction_jobs, u)))
 993
 994                         /* Ok, there is no job for this in the
 995                          * transaction, but maybe there is already one
 996                          * running? */
 997                         if (!(o = u->meta.job))
 998                                 continue;
 999
1000                 if ((r = transaction_verify_order_one(m, o, j, generation, e)) < 0)
1001                         return r;
1002         }
1003
1004         /* Ok, let's backtrack, and remember that this entry is not on
1005          * our path anymore. */
1006         j->marker = NULL;
1007
1008         return 0;
1009 }
1010
1011 static int transaction_verify_order(Manager *m, unsigned *generation, DBusError *e) {
1012         Job *j;
1013         int r;
1014         Iterator i;
1015         unsigned g;
1016
1017         assert(m);
1018         assert(generation);
1019
1020         /* Check if the ordering graph is cyclic. If it is, try to fix
1021          * that up by dropping one of the jobs. */
1022
1023         g = (*generation)++;
1024
1025         HASHMAP_FOREACH(j, m->transaction_jobs, i)
1026                 if ((r = transaction_verify_order_one(m, j, NULL, g, e)) < 0)
1027                         return r;
1028
1029         return 0;
1030 }
1031
1032 static void transaction_collect_garbage(Manager *m) {
1033         bool again;
1034
1035         assert(m);
1036
1037         /* Drop jobs that are not required by any other job */
1038
1039         do {
1040                 Iterator i;
1041                 Job *j;
1042
1043                 again = false;
1044
1045                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1046                         if (j->object_list)
1047                                 continue;
1048
1049                         log_debug("Garbage collecting job %s/%s", j->unit->meta.id, job_type_to_string(j->type));
1050                         transaction_delete_job(m, j, true);
1051                         again = true;
1052                         break;
1053                 }
1054
1055         } while (again);
1056 }
1057
1058 static int transaction_is_destructive(Manager *m, DBusError *e) {
1059         Iterator i;
1060         Job *j;
1061
1062         assert(m);
1063
1064         /* Checks whether applying this transaction means that
1065          * existing jobs would be replaced */
1066
1067         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1068
1069                 /* Assume merged */
1070                 assert(!j->transaction_prev);
1071                 assert(!j->transaction_next);
1072
1073                 if (j->unit->meta.job &&
1074                     j->unit->meta.job != j &&
1075                     !job_type_is_superset(j->type, j->unit->meta.job->type)) {
1076
1077                         dbus_set_error(e, BUS_ERROR_TRANSACTION_IS_DESTRUCTIVE, "Transaction is destructive.");
1078                         return -EEXIST;
1079                 }
1080         }
1081
1082         return 0;
1083 }
1084
1085 static void transaction_minimize_impact(Manager *m) {
1086         bool again;
1087         assert(m);
1088
1089         /* Drops all unnecessary jobs that reverse already active jobs
1090          * or that stop a running service. */
1091
1092         do {
1093                 Job *j;
1094                 Iterator i;
1095
1096                 again = false;
1097
1098                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1099                         LIST_FOREACH(transaction, j, j) {
1100                                 bool stops_running_service, changes_existing_job;
1101
1102                                 /* If it matters, we shouldn't drop it */
1103                                 if (j->matters_to_anchor)
1104                                         continue;
1105
1106                                 /* Would this stop a running service?
1107                                  * Would this change an existing job?
1108                                  * If so, let's drop this entry */
1109
1110                                 stops_running_service =
1111                                         j->type == JOB_STOP && UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(j->unit));
1112
1113                                 changes_existing_job =
1114                                         j->unit->meta.job && job_type_is_conflicting(j->type, j->unit->meta.job->type);
1115
1116                                 if (!stops_running_service && !changes_existing_job)
1117                                         continue;
1118
1119                                 if (stops_running_service)
1120                                         log_info("%s/%s would stop a running service.", j->unit->meta.id, job_type_to_string(j->type));
1121
1122                                 if (changes_existing_job)
1123                                         log_info("%s/%s would change existing job.", j->unit->meta.id, job_type_to_string(j->type));
1124
1125                                 /* Ok, let's get rid of this */
1126                                 log_info("Deleting %s/%s to minimize impact.", j->unit->meta.id, job_type_to_string(j->type));
1127
1128                                 transaction_delete_job(m, j, true);
1129                                 again = true;
1130                                 break;
1131                         }
1132
1133                         if (again)
1134                                 break;
1135                 }
1136
1137         } while (again);
1138 }
1139
1140 static int transaction_apply(Manager *m) {
1141         Iterator i;
1142         Job *j;
1143         int r;
1144
1145         /* Moves the transaction jobs to the set of active jobs */
1146
1147         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1148                 /* Assume merged */
1149                 assert(!j->transaction_prev);
1150                 assert(!j->transaction_next);
1151
1152                 if (j->installed)
1153                         continue;
1154
1155                 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
1156                         goto rollback;
1157         }
1158
1159         while ((j = hashmap_steal_first(m->transaction_jobs))) {
1160                 if (j->installed)
1161                         continue;
1162
1163                 if (j->unit->meta.job)
1164                         job_free(j->unit->meta.job);
1165
1166                 j->unit->meta.job = j;
1167                 j->installed = true;
1168
1169                 /* We're fully installed. Now let's free data we don't
1170                  * need anymore. */
1171
1172                 assert(!j->transaction_next);
1173                 assert(!j->transaction_prev);
1174
1175                 job_add_to_run_queue(j);
1176                 job_add_to_dbus_queue(j);
1177                 job_start_timer(j);
1178         }
1179
1180         /* As last step, kill all remaining job dependencies. */
1181         transaction_clean_dependencies(m);
1182
1183         return 0;
1184
1185 rollback:
1186
1187         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1188                 if (j->installed)
1189                         continue;
1190
1191                 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
1192         }
1193
1194         return r;
1195 }
1196
1197 static int transaction_activate(Manager *m, JobMode mode, DBusError *e) {
1198         int r;
1199         unsigned generation = 1;
1200
1201         assert(m);
1202
1203         /* This applies the changes recorded in transaction_jobs to
1204          * the actual list of jobs, if possible. */
1205
1206         /* First step: figure out which jobs matter */
1207         transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
1208
1209         /* Second step: Try not to stop any running services if
1210          * we don't have to. Don't try to reverse running
1211          * jobs if we don't have to. */
1212         transaction_minimize_impact(m);
1213
1214         /* Third step: Drop redundant jobs */
1215         transaction_drop_redundant(m);
1216
1217         for (;;) {
1218                 /* Fourth step: Let's remove unneeded jobs that might
1219                  * be lurking. */
1220                 transaction_collect_garbage(m);
1221
1222                 /* Fifth step: verify order makes sense and correct
1223                  * cycles if necessary and possible */
1224                 if ((r = transaction_verify_order(m, &generation, e)) >= 0)
1225                         break;
1226
1227                 if (r != -EAGAIN) {
1228                         log_warning("Requested transaction contains an unfixable cyclic ordering dependency: %s", bus_error(e, r));
1229                         goto rollback;
1230                 }
1231
1232                 /* Let's see if the resulting transaction ordering
1233                  * graph is still cyclic... */
1234         }
1235
1236         for (;;) {
1237                 /* Sixth step: let's drop unmergeable entries if
1238                  * necessary and possible, merge entries we can
1239                  * merge */
1240                 if ((r = transaction_merge_jobs(m, e)) >= 0)
1241                         break;
1242
1243                 if (r != -EAGAIN) {
1244                         log_warning("Requested transaction contains unmergable jobs: %s", bus_error(e, r));
1245                         goto rollback;
1246                 }
1247
1248                 /* Seventh step: an entry got dropped, let's garbage
1249                  * collect its dependencies. */
1250                 transaction_collect_garbage(m);
1251
1252                 /* Let's see if the resulting transaction still has
1253                  * unmergeable entries ... */
1254         }
1255
1256         /* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */
1257         transaction_drop_redundant(m);
1258
1259         /* Ninth step: check whether we can actually apply this */
1260         if (mode == JOB_FAIL)
1261                 if ((r = transaction_is_destructive(m, e)) < 0) {
1262                         log_notice("Requested transaction contradicts existing jobs: %s", bus_error(e, r));
1263                         goto rollback;
1264                 }
1265
1266         /* Tenth step: apply changes */
1267         if ((r = transaction_apply(m)) < 0) {
1268                 log_warning("Failed to apply transaction: %s", strerror(-r));
1269                 goto rollback;
1270         }
1271
1272         assert(hashmap_isempty(m->transaction_jobs));
1273         assert(!m->transaction_anchor);
1274
1275         return 0;
1276
1277 rollback:
1278         transaction_abort(m);
1279         return r;
1280 }
1281
1282 static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool override, bool *is_new) {
1283         Job *j, *f;
1284         int r;
1285
1286         assert(m);
1287         assert(unit);
1288
1289         /* Looks for an axisting prospective job and returns that. If
1290          * it doesn't exist it is created and added to the prospective
1291          * jobs list. */
1292
1293         f = hashmap_get(m->transaction_jobs, unit);
1294
1295         LIST_FOREACH(transaction, j, f) {
1296                 assert(j->unit == unit);
1297
1298                 if (j->type == type) {
1299                         if (is_new)
1300                                 *is_new = false;
1301                         return j;
1302                 }
1303         }
1304
1305         if (unit->meta.job && unit->meta.job->type == type)
1306                 j = unit->meta.job;
1307         else if (!(j = job_new(m, type, unit)))
1308                 return NULL;
1309
1310         j->generation = 0;
1311         j->marker = NULL;
1312         j->matters_to_anchor = false;
1313         j->override = override;
1314
1315         LIST_PREPEND(Job, transaction, f, j);
1316
1317         if ((r = hashmap_replace(m->transaction_jobs, unit, f)) < 0) {
1318                 job_free(j);
1319                 return NULL;
1320         }
1321
1322         if (is_new)
1323                 *is_new = true;
1324
1325         log_debug("Added job %s/%s to transaction.", unit->meta.id, job_type_to_string(type));
1326
1327         return j;
1328 }
1329
1330 void manager_transaction_unlink_job(Manager *m, Job *j, bool delete_dependencies) {
1331         assert(m);
1332         assert(j);
1333
1334         if (j->transaction_prev)
1335                 j->transaction_prev->transaction_next = j->transaction_next;
1336         else if (j->transaction_next)
1337                 hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
1338         else
1339                 hashmap_remove_value(m->transaction_jobs, j->unit, j);
1340
1341         if (j->transaction_next)
1342                 j->transaction_next->transaction_prev = j->transaction_prev;
1343
1344         j->transaction_prev = j->transaction_next = NULL;
1345
1346         while (j->subject_list)
1347                 job_dependency_free(j->subject_list);
1348
1349         while (j->object_list) {
1350                 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
1351
1352                 job_dependency_free(j->object_list);
1353
1354                 if (other && delete_dependencies) {
1355                         log_debug("Deleting job %s/%s as dependency of job %s/%s",
1356                                   other->unit->meta.id, job_type_to_string(other->type),
1357                                   j->unit->meta.id, job_type_to_string(j->type));
1358                         transaction_delete_job(m, other, delete_dependencies);
1359                 }
1360         }
1361 }
1362
1363 static int transaction_add_job_and_dependencies(
1364                 Manager *m,
1365                 JobType type,
1366                 Unit *unit,
1367                 Job *by,
1368                 bool matters,
1369                 bool override,
1370                 bool conflicts,
1371                 DBusError *e,
1372                 Job **_ret) {
1373         Job *ret;
1374         Iterator i;
1375         Unit *dep;
1376         int r;
1377         bool is_new;
1378
1379         assert(m);
1380         assert(type < _JOB_TYPE_MAX);
1381         assert(unit);
1382
1383         if (type != JOB_STOP &&
1384             unit->meta.load_state != UNIT_LOADED) {
1385                 dbus_set_error(e, BUS_ERROR_LOAD_FAILED, "Unit %s failed to load. See logs for details.", unit->meta.id);
1386                 return -EINVAL;
1387         }
1388
1389         if (!unit_job_is_applicable(unit, type)) {
1390                 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);
1391                 return -EBADR;
1392         }
1393
1394         /* First add the job. */
1395         if (!(ret = transaction_add_one_job(m, type, unit, override, &is_new)))
1396                 return -ENOMEM;
1397
1398         /* Then, add a link to the job. */
1399         if (!job_dependency_new(by, ret, matters, conflicts))
1400                 return -ENOMEM;
1401
1402         if (is_new) {
1403                 /* Finally, recursively add in all dependencies. */
1404                 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
1405                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
1406                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, override, false, e, NULL)) < 0 && r != -EBADR)
1407                                         goto fail;
1408
1409                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
1410                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !override, override, false, e, NULL)) < 0 && r != -EBADR) {
1411                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, bus_error(e, r));
1412                                         dbus_error_free(e);
1413                                 }
1414
1415                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
1416                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, false, false, e, NULL)) < 0) {
1417                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, bus_error(e, r));
1418                                         dbus_error_free(e);
1419                                 }
1420
1421                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
1422                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, override, false, e, NULL)) < 0 && r != -EBADR)
1423                                         goto fail;
1424
1425                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE_OVERRIDABLE], i)
1426                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !override, override, false, e, NULL)) < 0 && r != -EBADR) {
1427                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, bus_error(e, r));
1428                                         dbus_error_free(e);
1429                                 }
1430
1431                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
1432                                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, override, true, e, NULL)) < 0 && r != -EBADR)
1433                                         goto fail;
1434
1435                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTED_BY], i)
1436                                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, override, false, e, NULL)) < 0 && r != -EBADR)
1437                                         goto fail;
1438
1439                 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
1440
1441                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
1442                                 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, override, false, e, NULL)) < 0 && r != -EBADR)
1443                                         goto fail;
1444                 }
1445
1446                 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
1447         }
1448
1449         if (_ret)
1450                 *_ret = ret;
1451
1452         return 0;
1453
1454 fail:
1455         return r;
1456 }
1457
1458 static int transaction_add_isolate_jobs(Manager *m) {
1459         Iterator i;
1460         Unit *u;
1461         char *k;
1462         int r;
1463
1464         assert(m);
1465
1466         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
1467
1468                 /* ignore aliases */
1469                 if (u->meta.id != k)
1470                         continue;
1471
1472                 if (UNIT_VTABLE(u)->no_isolate)
1473                         continue;
1474
1475                 /* No need to stop inactive jobs */
1476                 if (UNIT_IS_INACTIVE_OR_MAINTENANCE(unit_active_state(u)))
1477                         continue;
1478
1479                 /* Is there already something listed for this? */
1480                 if (hashmap_get(m->transaction_jobs, u))
1481                         continue;
1482
1483                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, u, NULL, true, false, false, NULL, NULL)) < 0)
1484                         log_warning("Cannot add isolate job for unit %s, ignoring: %s", u->meta.id, strerror(-r));
1485         }
1486
1487         return 0;
1488 }
1489
1490 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool override, DBusError *e, Job **_ret) {
1491         int r;
1492         Job *ret;
1493
1494         assert(m);
1495         assert(type < _JOB_TYPE_MAX);
1496         assert(unit);
1497         assert(mode < _JOB_MODE_MAX);
1498
1499         if (mode == JOB_ISOLATE && type != JOB_START) {
1500                 dbus_set_error(e, BUS_ERROR_INVALID_JOB_MODE, "Isolate is only valid for start.");
1501                 return -EINVAL;
1502         }
1503
1504         log_debug("Trying to enqueue job %s/%s", unit->meta.id, job_type_to_string(type));
1505
1506         if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, override, false, e, &ret)) < 0) {
1507                 transaction_abort(m);
1508                 return r;
1509         }
1510
1511         if (mode == JOB_ISOLATE)
1512                 if ((r = transaction_add_isolate_jobs(m)) < 0) {
1513                         transaction_abort(m);
1514                         return r;
1515                 }
1516
1517         if ((r = transaction_activate(m, mode, e)) < 0)
1518                 return r;
1519
1520         log_debug("Enqueued job %s/%s as %u", unit->meta.id, job_type_to_string(type), (unsigned) ret->id);
1521
1522         if (_ret)
1523                 *_ret = ret;
1524
1525         return 0;
1526 }
1527
1528 int manager_add_job_by_name(Manager *m, JobType type, const char *name, JobMode mode, bool override, DBusError *e, Job **_ret) {
1529         Unit *unit;
1530         int r;
1531
1532         assert(m);
1533         assert(type < _JOB_TYPE_MAX);
1534         assert(name);
1535         assert(mode < _JOB_MODE_MAX);
1536
1537         if ((r = manager_load_unit(m, name, NULL, NULL, &unit)) < 0)
1538                 return r;
1539
1540         return manager_add_job(m, type, unit, mode, override, e, _ret);
1541 }
1542
1543 Job *manager_get_job(Manager *m, uint32_t id) {
1544         assert(m);
1545
1546         return hashmap_get(m->jobs, UINT32_TO_PTR(id));
1547 }
1548
1549 Unit *manager_get_unit(Manager *m, const char *name) {
1550         assert(m);
1551         assert(name);
1552
1553         return hashmap_get(m->units, name);
1554 }
1555
1556 unsigned manager_dispatch_load_queue(Manager *m) {
1557         Meta *meta;
1558         unsigned n = 0;
1559
1560         assert(m);
1561
1562         /* Make sure we are not run recursively */
1563         if (m->dispatching_load_queue)
1564                 return 0;
1565
1566         m->dispatching_load_queue = true;
1567
1568         /* Dispatches the load queue. Takes a unit from the queue and
1569          * tries to load its data until the queue is empty */
1570
1571         while ((meta = m->load_queue)) {
1572                 assert(meta->in_load_queue);
1573
1574                 unit_load((Unit*) meta);
1575                 n++;
1576         }
1577
1578         m->dispatching_load_queue = false;
1579         return n;
1580 }
1581
1582 int manager_load_unit_prepare(Manager *m, const char *name, const char *path, DBusError *e, Unit **_ret) {
1583         Unit *ret;
1584         int r;
1585
1586         assert(m);
1587         assert(name || path);
1588
1589         /* This will prepare the unit for loading, but not actually
1590          * load anything from disk. */
1591
1592         if (path && !is_path(path)) {
1593                 dbus_set_error(e, BUS_ERROR_INVALID_PATH, "Path %s is not absolute.", path);
1594                 return -EINVAL;
1595         }
1596
1597         if (!name)
1598                 name = file_name_from_path(path);
1599
1600         if (!unit_name_is_valid(name)) {
1601                 dbus_set_error(e, BUS_ERROR_INVALID_NAME, "Unit name %s is not valid.", name);
1602                 return -EINVAL;
1603         }
1604
1605         if ((ret = manager_get_unit(m, name))) {
1606                 *_ret = ret;
1607                 return 1;
1608         }
1609
1610         if (!(ret = unit_new(m)))
1611                 return -ENOMEM;
1612
1613         if (path)
1614                 if (!(ret->meta.fragment_path = strdup(path))) {
1615                         unit_free(ret);
1616                         return -ENOMEM;
1617                 }
1618
1619         if ((r = unit_add_name(ret, name)) < 0) {
1620                 unit_free(ret);
1621                 return r;
1622         }
1623
1624         unit_add_to_load_queue(ret);
1625         unit_add_to_dbus_queue(ret);
1626         unit_add_to_gc_queue(ret);
1627
1628         if (_ret)
1629                 *_ret = ret;
1630
1631         return 0;
1632 }
1633
1634 int manager_load_unit(Manager *m, const char *name, const char *path, DBusError *e, Unit **_ret) {
1635         int r;
1636
1637         assert(m);
1638
1639         /* This will load the service information files, but not actually
1640          * start any services or anything. */
1641
1642         if ((r = manager_load_unit_prepare(m, name, path, e, _ret)) != 0)
1643                 return r;
1644
1645         manager_dispatch_load_queue(m);
1646
1647         if (_ret)
1648                 *_ret = unit_follow_merge(*_ret);
1649
1650         return 0;
1651 }
1652
1653 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
1654         Iterator i;
1655         Job *j;
1656
1657         assert(s);
1658         assert(f);
1659
1660         HASHMAP_FOREACH(j, s->jobs, i)
1661                 job_dump(j, f, prefix);
1662 }
1663
1664 void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
1665         Iterator i;
1666         Unit *u;
1667         const char *t;
1668
1669         assert(s);
1670         assert(f);
1671
1672         HASHMAP_FOREACH_KEY(u, t, s->units, i)
1673                 if (u->meta.id == t)
1674                         unit_dump(u, f, prefix);
1675 }
1676
1677 void manager_clear_jobs(Manager *m) {
1678         Job *j;
1679
1680         assert(m);
1681
1682         transaction_abort(m);
1683
1684         while ((j = hashmap_first(m->jobs)))
1685                 job_free(j);
1686 }
1687
1688 unsigned manager_dispatch_run_queue(Manager *m) {
1689         Job *j;
1690         unsigned n = 0;
1691
1692         if (m->dispatching_run_queue)
1693                 return 0;
1694
1695         m->dispatching_run_queue = true;
1696
1697         while ((j = m->run_queue)) {
1698                 assert(j->installed);
1699                 assert(j->in_run_queue);
1700
1701                 job_run_and_invalidate(j);
1702                 n++;
1703         }
1704
1705         m->dispatching_run_queue = false;
1706         return n;
1707 }
1708
1709 unsigned manager_dispatch_dbus_queue(Manager *m) {
1710         Job *j;
1711         Meta *meta;
1712         unsigned n = 0;
1713
1714         assert(m);
1715
1716         if (m->dispatching_dbus_queue)
1717                 return 0;
1718
1719         m->dispatching_dbus_queue = true;
1720
1721         while ((meta = m->dbus_unit_queue)) {
1722                 assert(meta->in_dbus_queue);
1723
1724                 bus_unit_send_change_signal((Unit*) meta);
1725                 n++;
1726         }
1727
1728         while ((j = m->dbus_job_queue)) {
1729                 assert(j->in_dbus_queue);
1730
1731                 bus_job_send_change_signal(j);
1732                 n++;
1733         }
1734
1735         m->dispatching_dbus_queue = false;
1736         return n;
1737 }
1738
1739 static int manager_process_notify_fd(Manager *m) {
1740         ssize_t n;
1741
1742         assert(m);
1743
1744         for (;;) {
1745                 char buf[4096];
1746                 struct msghdr msghdr;
1747                 struct iovec iovec;
1748                 struct ucred *ucred;
1749                 union {
1750                         struct cmsghdr cmsghdr;
1751                         uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
1752                 } control;
1753                 Unit *u;
1754                 char **tags;
1755
1756                 zero(iovec);
1757                 iovec.iov_base = buf;
1758                 iovec.iov_len = sizeof(buf)-1;
1759
1760                 zero(control);
1761                 zero(msghdr);
1762                 msghdr.msg_iov = &iovec;
1763                 msghdr.msg_iovlen = 1;
1764                 msghdr.msg_control = &control;
1765                 msghdr.msg_controllen = sizeof(control);
1766
1767                 if ((n = recvmsg(m->notify_watch.fd, &msghdr, MSG_DONTWAIT)) <= 0) {
1768                         if (n >= 0)
1769                                 return -EIO;
1770
1771                         if (errno == EAGAIN)
1772                                 break;
1773
1774                         return -errno;
1775                 }
1776
1777                 if (msghdr.msg_controllen < CMSG_LEN(sizeof(struct ucred)) ||
1778                     control.cmsghdr.cmsg_level != SOL_SOCKET ||
1779                     control.cmsghdr.cmsg_type != SCM_CREDENTIALS ||
1780                     control.cmsghdr.cmsg_len != CMSG_LEN(sizeof(struct ucred))) {
1781                         log_warning("Received notify message without credentials. Ignoring.");
1782                         continue;
1783                 }
1784
1785                 ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
1786
1787                 if (!(u = hashmap_get(m->watch_pids, LONG_TO_PTR(ucred->pid))))
1788                         if (!(u = cgroup_unit_by_pid(m, ucred->pid))) {
1789                                 log_warning("Cannot find unit for notify message of PID %lu.", (unsigned long) ucred->pid);
1790                                 continue;
1791                         }
1792
1793                 assert((size_t) n < sizeof(buf));
1794                 buf[n] = 0;
1795                 if (!(tags = strv_split(buf, "\n\r")))
1796                         return -ENOMEM;
1797
1798                 log_debug("Got notification message for unit %s", u->meta.id);
1799
1800                 if (UNIT_VTABLE(u)->notify_message)
1801                         UNIT_VTABLE(u)->notify_message(u, ucred->pid, tags);
1802
1803                 strv_free(tags);
1804         }
1805
1806         return 0;
1807 }
1808
1809 static int manager_dispatch_sigchld(Manager *m) {
1810         assert(m);
1811
1812         for (;;) {
1813                 siginfo_t si;
1814                 Unit *u;
1815                 int r;
1816
1817                 zero(si);
1818
1819                 /* First we call waitd() for a PID and do not reap the
1820                  * zombie. That way we can still access /proc/$PID for
1821                  * it while it is a zombie. */
1822                 if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG|WNOWAIT) < 0) {
1823
1824                         if (errno == ECHILD)
1825                                 break;
1826
1827                         if (errno == EINTR)
1828                                 continue;
1829
1830                         return -errno;
1831                 }
1832
1833                 if (si.si_pid <= 0)
1834                         break;
1835
1836                 if (si.si_code == CLD_EXITED || si.si_code == CLD_KILLED || si.si_code == CLD_DUMPED) {
1837                         char *name = NULL;
1838
1839                         get_process_name(si.si_pid, &name);
1840                         log_debug("Got SIGCHLD for process %lu (%s)", (unsigned long) si.si_pid, strna(name));
1841                         free(name);
1842                 }
1843
1844                 /* Let's flush any message the dying child might still
1845                  * have queued for us. This ensures that the process
1846                  * still exists in /proc so that we can figure out
1847                  * which cgroup and hence unit it belongs to. */
1848                 if ((r = manager_process_notify_fd(m)) < 0)
1849                         return r;
1850
1851                 /* And now figure out the unit this belongs to */
1852                 if (!(u = hashmap_get(m->watch_pids, LONG_TO_PTR(si.si_pid))))
1853                         u = cgroup_unit_by_pid(m, si.si_pid);
1854
1855                 /* And now, we actually reap the zombie. */
1856                 if (waitid(P_PID, si.si_pid, &si, WEXITED) < 0) {
1857                         if (errno == EINTR)
1858                                 continue;
1859
1860                         return -errno;
1861                 }
1862
1863                 if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
1864                         continue;
1865
1866                 log_debug("Child %lu died (code=%s, status=%i/%s)",
1867                           (long unsigned) si.si_pid,
1868                           sigchld_code_to_string(si.si_code),
1869                           si.si_status,
1870                           strna(si.si_code == CLD_EXITED ? exit_status_to_string(si.si_status) : signal_to_string(si.si_status)));
1871
1872                 if (!u)
1873                         continue;
1874
1875                 log_debug("Child %lu belongs to %s", (long unsigned) si.si_pid, u->meta.id);
1876
1877                 hashmap_remove(m->watch_pids, LONG_TO_PTR(si.si_pid));
1878                 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
1879         }
1880
1881         return 0;
1882 }
1883
1884 static int manager_start_target(Manager *m, const char *name, JobMode mode) {
1885         int r;
1886         DBusError error;
1887
1888         dbus_error_init(&error);
1889
1890         log_info("Activating special unit %s", name);
1891
1892         if ((r = manager_add_job_by_name(m, JOB_START, name, mode, true, &error, NULL)) < 0)
1893                 log_error("Failed to enqueue %s job: %s", name, bus_error(&error, r));
1894
1895         dbus_error_free(&error);
1896
1897         return r;
1898 }
1899
1900 static int manager_process_signal_fd(Manager *m) {
1901         ssize_t n;
1902         struct signalfd_siginfo sfsi;
1903         bool sigchld = false;
1904
1905         assert(m);
1906
1907         for (;;) {
1908                 if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
1909
1910                         if (n >= 0)
1911                                 return -EIO;
1912
1913                         if (errno == EAGAIN)
1914                                 break;
1915
1916                         return -errno;
1917                 }
1918
1919                 log_debug("Received SIG%s", strna(signal_to_string(sfsi.ssi_signo)));
1920
1921                 switch (sfsi.ssi_signo) {
1922
1923                 case SIGCHLD:
1924                         sigchld = true;
1925                         break;
1926
1927                 case SIGTERM:
1928                         if (m->running_as == MANAGER_SYSTEM) {
1929                                 /* This is for compatibility with the
1930                                  * original sysvinit */
1931                                 m->exit_code = MANAGER_REEXECUTE;
1932                                 break;
1933                         }
1934
1935                         /* Fall through */
1936
1937                 case SIGINT:
1938                         if (m->running_as == MANAGER_SYSTEM) {
1939                                 manager_start_target(m, SPECIAL_CTRL_ALT_DEL_TARGET, JOB_REPLACE);
1940                                 break;
1941                         }
1942
1943                         /* Run the exit target if there is one, if not, just exit. */
1944                         if (manager_start_target(m, SPECIAL_EXIT_SERVICE, JOB_REPLACE) < 0) {
1945                                 m->exit_code = MANAGER_EXIT;
1946                                 return 0;
1947                         }
1948
1949                         break;
1950
1951                 case SIGWINCH:
1952                         if (m->running_as == MANAGER_SYSTEM)
1953                                 manager_start_target(m, SPECIAL_KBREQUEST_TARGET, JOB_REPLACE);
1954
1955                         /* This is a nop on non-init */
1956                         break;
1957
1958                 case SIGPWR:
1959                         if (m->running_as == MANAGER_SYSTEM)
1960                                 manager_start_target(m, SPECIAL_SIGPWR_TARGET, JOB_REPLACE);
1961
1962                         /* This is a nop on non-init */
1963                         break;
1964
1965                 case SIGUSR1: {
1966                         Unit *u;
1967
1968                         u = manager_get_unit(m, SPECIAL_DBUS_SERVICE);
1969
1970                         if (!u || UNIT_IS_ACTIVE_OR_RELOADING(unit_active_state(u))) {
1971                                 log_info("Trying to reconnect to bus...");
1972                                 bus_init(m);
1973                         }
1974
1975                         if (!u || !UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u))) {
1976                                 log_info("Loading D-Bus service...");
1977                                 manager_start_target(m, SPECIAL_DBUS_SERVICE, JOB_REPLACE);
1978                         }
1979
1980                         break;
1981                 }
1982
1983                 case SIGUSR2: {
1984                         FILE *f;
1985                         char *dump = NULL;
1986                         size_t size;
1987
1988                         if (!(f = open_memstream(&dump, &size))) {
1989                                 log_warning("Failed to allocate memory stream.");
1990                                 break;
1991                         }
1992
1993                         manager_dump_units(m, f, "\t");
1994                         manager_dump_jobs(m, f, "\t");
1995
1996                         if (ferror(f)) {
1997                                 fclose(f);
1998                                 free(dump);
1999                                 log_warning("Failed to write status stream");
2000                                 break;
2001                         }
2002
2003                         fclose(f);
2004                         log_dump(LOG_INFO, dump);
2005                         free(dump);
2006
2007                         break;
2008                 }
2009
2010                 case SIGHUP:
2011                         m->exit_code = MANAGER_RELOAD;
2012                         break;
2013
2014                 default: {
2015                         static const char * const table[] = {
2016                                 [0] = SPECIAL_DEFAULT_TARGET,
2017                                 [1] = SPECIAL_RESCUE_TARGET,
2018                                 [2] = SPECIAL_EMERGENCY_TARGET,
2019                                 [3] = SPECIAL_HALT_TARGET,
2020                                 [4] = SPECIAL_POWEROFF_TARGET,
2021                                 [5] = SPECIAL_REBOOT_TARGET
2022                         };
2023
2024                         if ((int) sfsi.ssi_signo >= SIGRTMIN+0 &&
2025                             (int) sfsi.ssi_signo < SIGRTMIN+(int) ELEMENTSOF(table)) {
2026                                 manager_start_target(m, table[sfsi.ssi_signo - SIGRTMIN],
2027                                                      (sfsi.ssi_signo == 1 || sfsi.ssi_signo == 2) ? JOB_ISOLATE : JOB_REPLACE);
2028                                 break;
2029                         }
2030
2031                         log_warning("Got unhandled signal <%s>.", strna(signal_to_string(sfsi.ssi_signo)));
2032                 }
2033                 }
2034         }
2035
2036         if (sigchld)
2037                 return manager_dispatch_sigchld(m);
2038
2039         return 0;
2040 }
2041
2042 static int process_event(Manager *m, struct epoll_event *ev) {
2043         int r;
2044         Watch *w;
2045
2046         assert(m);
2047         assert(ev);
2048
2049         assert(w = ev->data.ptr);
2050
2051         switch (w->type) {
2052
2053         case WATCH_SIGNAL:
2054
2055                 /* An incoming signal? */
2056                 if (ev->events != EPOLLIN)
2057                         return -EINVAL;
2058
2059                 if ((r = manager_process_signal_fd(m)) < 0)
2060                         return r;
2061
2062                 break;
2063
2064         case WATCH_NOTIFY:
2065
2066                 /* An incoming daemon notification event? */
2067                 if (ev->events != EPOLLIN)
2068                         return -EINVAL;
2069
2070                 if ((r = manager_process_notify_fd(m)) < 0)
2071                         return r;
2072
2073                 break;
2074
2075         case WATCH_FD:
2076
2077                 /* Some fd event, to be dispatched to the units */
2078                 UNIT_VTABLE(w->data.unit)->fd_event(w->data.unit, w->fd, ev->events, w);
2079                 break;
2080
2081         case WATCH_UNIT_TIMER:
2082         case WATCH_JOB_TIMER: {
2083                 uint64_t v;
2084                 ssize_t k;
2085
2086                 /* Some timer event, to be dispatched to the units */
2087                 if ((k = read(w->fd, &v, sizeof(v))) != sizeof(v)) {
2088
2089                         if (k < 0 && (errno == EINTR || errno == EAGAIN))
2090                                 break;
2091
2092                         return k < 0 ? -errno : -EIO;
2093                 }
2094
2095                 if (w->type == WATCH_UNIT_TIMER)
2096                         UNIT_VTABLE(w->data.unit)->timer_event(w->data.unit, v, w);
2097                 else
2098                         job_timer_event(w->data.job, v, w);
2099                 break;
2100         }
2101
2102         case WATCH_MOUNT:
2103                 /* Some mount table change, intended for the mount subsystem */
2104                 mount_fd_event(m, ev->events);
2105                 break;
2106
2107         case WATCH_UDEV:
2108                 /* Some notification from udev, intended for the device subsystem */
2109                 device_fd_event(m, ev->events);
2110                 break;
2111
2112         case WATCH_DBUS_WATCH:
2113                 bus_watch_event(m, w, ev->events);
2114                 break;
2115
2116         case WATCH_DBUS_TIMEOUT:
2117                 bus_timeout_event(m, w, ev->events);
2118                 break;
2119
2120         default:
2121                 assert_not_reached("Unknown epoll event type.");
2122         }
2123
2124         return 0;
2125 }
2126
2127 int manager_loop(Manager *m) {
2128         int r;
2129
2130         RATELIMIT_DEFINE(rl, 1*USEC_PER_SEC, 1000);
2131
2132         assert(m);
2133         m->exit_code = MANAGER_RUNNING;
2134
2135         /* Release the path cache */
2136         set_free_free(m->unit_path_cache);
2137         m->unit_path_cache = NULL;
2138
2139         /* There might still be some zombies hanging around from
2140          * before we were exec()'ed. Leat's reap them */
2141         if ((r = manager_dispatch_sigchld(m)) < 0)
2142                 return r;
2143
2144         while (m->exit_code == MANAGER_RUNNING) {
2145                 struct epoll_event event;
2146                 int n;
2147
2148                 if (!ratelimit_test(&rl)) {
2149                         /* Yay, something is going seriously wrong, pause a little */
2150                         log_warning("Looping too fast. Throttling execution a little.");
2151                         sleep(1);
2152                 }
2153
2154                 if (manager_dispatch_load_queue(m) > 0)
2155                         continue;
2156
2157                 if (manager_dispatch_run_queue(m) > 0)
2158                         continue;
2159
2160                 if (bus_dispatch(m) > 0)
2161                         continue;
2162
2163                 if (manager_dispatch_cleanup_queue(m) > 0)
2164                         continue;
2165
2166                 if (manager_dispatch_gc_queue(m) > 0)
2167                         continue;
2168
2169                 if (manager_dispatch_dbus_queue(m) > 0)
2170                         continue;
2171
2172                 if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) {
2173
2174                         if (errno == EINTR)
2175                                 continue;
2176
2177                         return -errno;
2178                 }
2179
2180                 assert(n == 1);
2181
2182                 if ((r = process_event(m, &event)) < 0)
2183                         return r;
2184         }
2185
2186         return m->exit_code;
2187 }
2188
2189 int manager_get_unit_from_dbus_path(Manager *m, const char *s, Unit **_u) {
2190         char *n;
2191         Unit *u;
2192
2193         assert(m);
2194         assert(s);
2195         assert(_u);
2196
2197         if (!startswith(s, "/org/freedesktop/systemd1/unit/"))
2198                 return -EINVAL;
2199
2200         if (!(n = bus_path_unescape(s+31)))
2201                 return -ENOMEM;
2202
2203         u = manager_get_unit(m, n);
2204         free(n);
2205
2206         if (!u)
2207                 return -ENOENT;
2208
2209         *_u = u;
2210
2211         return 0;
2212 }
2213
2214 int manager_get_job_from_dbus_path(Manager *m, const char *s, Job **_j) {
2215         Job *j;
2216         unsigned id;
2217         int r;
2218
2219         assert(m);
2220         assert(s);
2221         assert(_j);
2222
2223         if (!startswith(s, "/org/freedesktop/systemd1/job/"))
2224                 return -EINVAL;
2225
2226         if ((r = safe_atou(s + 30, &id)) < 0)
2227                 return r;
2228
2229         if (!(j = manager_get_job(m, id)))
2230                 return -ENOENT;
2231
2232         *_j = j;
2233
2234         return 0;
2235 }
2236
2237 static bool manager_utmp_good(Manager *m) {
2238         int r;
2239
2240         assert(m);
2241
2242         if ((r = mount_path_is_mounted(m, _PATH_UTMPX)) <= 0) {
2243
2244                 if (r < 0)
2245                         log_warning("Failed to determine whether " _PATH_UTMPX " is mounted: %s", strerror(-r));
2246
2247                 return false;
2248         }
2249
2250         return true;
2251 }
2252
2253 void manager_write_utmp_reboot(Manager *m) {
2254         int r;
2255
2256         assert(m);
2257
2258         if (m->utmp_reboot_written)
2259                 return;
2260
2261         if (m->running_as != MANAGER_SYSTEM)
2262                 return;
2263
2264         if (!manager_utmp_good(m))
2265                 return;
2266
2267         if ((r = utmp_put_reboot(m->startup_timestamp.realtime)) < 0) {
2268
2269                 if (r != -ENOENT && r != -EROFS)
2270                         log_warning("Failed to write utmp/wtmp: %s", strerror(-r));
2271
2272                 return;
2273         }
2274
2275         m->utmp_reboot_written = true;
2276 }
2277
2278 void manager_write_utmp_runlevel(Manager *m, Unit *u) {
2279         int runlevel, r;
2280
2281         assert(m);
2282         assert(u);
2283
2284         if (u->meta.type != UNIT_TARGET)
2285                 return;
2286
2287         if (m->running_as != MANAGER_SYSTEM)
2288                 return;
2289
2290         if (!manager_utmp_good(m))
2291                 return;
2292
2293         if ((runlevel = target_get_runlevel(TARGET(u))) <= 0)
2294                 return;
2295
2296         if ((r = utmp_put_runlevel(0, runlevel, 0)) < 0) {
2297
2298                 if (r != -ENOENT && r != -EROFS)
2299                         log_warning("Failed to write utmp/wtmp: %s", strerror(-r));
2300         }
2301 }
2302
2303 void manager_dispatch_bus_name_owner_changed(
2304                 Manager *m,
2305                 const char *name,
2306                 const char* old_owner,
2307                 const char *new_owner) {
2308
2309         Unit *u;
2310
2311         assert(m);
2312         assert(name);
2313
2314         if (!(u = hashmap_get(m->watch_bus, name)))
2315                 return;
2316
2317         UNIT_VTABLE(u)->bus_name_owner_change(u, name, old_owner, new_owner);
2318 }
2319
2320 void manager_dispatch_bus_query_pid_done(
2321                 Manager *m,
2322                 const char *name,
2323                 pid_t pid) {
2324
2325         Unit *u;
2326
2327         assert(m);
2328         assert(name);
2329         assert(pid >= 1);
2330
2331         if (!(u = hashmap_get(m->watch_bus, name)))
2332                 return;
2333
2334         UNIT_VTABLE(u)->bus_query_pid_done(u, name, pid);
2335 }
2336
2337 int manager_open_serialization(Manager *m, FILE **_f) {
2338         char *path;
2339         mode_t saved_umask;
2340         int fd;
2341         FILE *f;
2342
2343         assert(_f);
2344
2345         if (m->running_as == MANAGER_SYSTEM) {
2346                 mkdir_p("/dev/.systemd", 0755);
2347
2348                 if (asprintf(&path, "/dev/.systemd/dump-%lu-XXXXXX", (unsigned long) getpid()) < 0)
2349                         return -ENOMEM;
2350         } else {
2351                 if (asprintf(&path, "/tmp/systemd-dump-%lu-XXXXXX", (unsigned long) getpid()) < 0)
2352                         return -ENOMEM;
2353         }
2354
2355         saved_umask = umask(0077);
2356         fd = mkostemp(path, O_RDWR|O_CLOEXEC);
2357         umask(saved_umask);
2358
2359         if (fd < 0) {
2360                 free(path);
2361                 return -errno;
2362         }
2363
2364         unlink(path);
2365
2366         log_debug("Serializing state to %s", path);
2367         free(path);
2368
2369         if (!(f = fdopen(fd, "w+")) < 0)
2370                 return -errno;
2371
2372         *_f = f;
2373
2374         return 0;
2375 }
2376
2377 int manager_serialize(Manager *m, FILE *f, FDSet *fds) {
2378         Iterator i;
2379         Unit *u;
2380         const char *t;
2381         int r;
2382
2383         assert(m);
2384         assert(f);
2385         assert(fds);
2386
2387         HASHMAP_FOREACH_KEY(u, t, m->units, i) {
2388                 if (u->meta.id != t)
2389                         continue;
2390
2391                 if (!unit_can_serialize(u))
2392                         continue;
2393
2394                 /* Start marker */
2395                 fputs(u->meta.id, f);
2396                 fputc('\n', f);
2397
2398                 if ((r = unit_serialize(u, f, fds)) < 0)
2399                         return r;
2400         }
2401
2402         if (ferror(f))
2403                 return -EIO;
2404
2405         return 0;
2406 }
2407
2408 int manager_deserialize(Manager *m, FILE *f, FDSet *fds) {
2409         int r = 0;
2410
2411         assert(m);
2412         assert(f);
2413
2414         log_debug("Deserializing state...");
2415
2416         m->n_deserializing ++;
2417
2418         for (;;) {
2419                 Unit *u;
2420                 char name[UNIT_NAME_MAX+2];
2421
2422                 /* Start marker */
2423                 if (!fgets(name, sizeof(name), f)) {
2424                         if (feof(f))
2425                                 break;
2426
2427                         r = -errno;
2428                         goto finish;
2429                 }
2430
2431                 char_array_0(name);
2432
2433                 if ((r = manager_load_unit(m, strstrip(name), NULL, NULL, &u)) < 0)
2434                         goto finish;
2435
2436                 if ((r = unit_deserialize(u, f, fds)) < 0)
2437                         goto finish;
2438         }
2439
2440         if (ferror(f)) {
2441                 r = -EIO;
2442                 goto finish;
2443         }
2444
2445         r = 0;
2446
2447 finish:
2448         assert(m->n_deserializing > 0);
2449         m->n_deserializing --;
2450
2451         return r;
2452 }
2453
2454 int manager_reload(Manager *m) {
2455         int r, q;
2456         FILE *f;
2457         FDSet *fds;
2458
2459         assert(m);
2460
2461         if ((r = manager_open_serialization(m, &f)) < 0)
2462                 return r;
2463
2464         if (!(fds = fdset_new())) {
2465                 r = -ENOMEM;
2466                 goto finish;
2467         }
2468
2469         if ((r = manager_serialize(m, f, fds)) < 0)
2470                 goto finish;
2471
2472         if (fseeko(f, 0, SEEK_SET) < 0) {
2473                 r = -errno;
2474                 goto finish;
2475         }
2476
2477         /* From here on there is no way back. */
2478         manager_clear_jobs_and_units(m);
2479
2480         /* Find new unit paths */
2481         lookup_paths_free(&m->lookup_paths);
2482         if ((q = lookup_paths_init(&m->lookup_paths, m->running_as)) < 0)
2483                 r = q;
2484
2485         m->n_deserializing ++;
2486
2487         /* First, enumerate what we can from all config files */
2488         if ((q = manager_enumerate(m)) < 0)
2489                 r = q;
2490
2491         /* Second, deserialize our stored data */
2492         if ((q = manager_deserialize(m, f, fds)) < 0)
2493                 r = q;
2494
2495         fclose(f);
2496         f = NULL;
2497
2498         /* Third, fire things up! */
2499         if ((q = manager_coldplug(m)) < 0)
2500                 r = q;
2501
2502         assert(m->n_deserializing > 0);
2503         m->n_deserializing ++;
2504
2505 finish:
2506         if (f)
2507                 fclose(f);
2508
2509         if (fds)
2510                 fdset_free(fds);
2511
2512         return r;
2513 }
2514
2515 bool manager_is_booting_or_shutting_down(Manager *m) {
2516         Unit *u;
2517
2518         assert(m);
2519
2520         /* Is the initial job still around? */
2521         if (manager_get_job(m, 1))
2522                 return true;
2523
2524         /* Is there a job for the shutdown target? */
2525         if (((u = manager_get_unit(m, SPECIAL_SHUTDOWN_TARGET))))
2526                 return !!u->meta.job;
2527
2528         return false;
2529 }
2530
2531 void manager_reset_maintenance(Manager *m) {
2532         Unit *u;
2533         Iterator i;
2534
2535         assert(m);
2536
2537         HASHMAP_FOREACH(u, m->units, i)
2538                 unit_reset_maintenance(u);
2539 }
2540
2541 static const char* const manager_running_as_table[_MANAGER_RUNNING_AS_MAX] = {
2542         [MANAGER_SYSTEM] = "system",
2543         [MANAGER_SESSION] = "session"
2544 };
2545
2546 DEFINE_STRING_TABLE_LOOKUP(manager_running_as, ManagerRunningAs);