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 <sys/poll.h>
  31
  32 #include "manager.h"
  33 #include "hashmap.h"
  34 #include "macro.h"
  35 #include "strv.h"
  36 #include "log.h"
  37 #include "util.h"
  38 #include "ratelimit.h"
  39
  40 static int manager_setup_signals(Manager *m) {
  41         sigset_t mask;
  42         struct epoll_event ev;
  43
  44         assert(m);
  45
  46         assert_se(reset_all_signal_handlers() == 0);
  47
  48         assert_se(sigemptyset(&mask) == 0);
  49         assert_se(sigaddset(&mask, SIGCHLD) == 0);
  50         assert_se(sigaddset(&mask, SIGINT) == 0);   /* Kernel sends us this on control-alt-del */
  51         assert_se(sigaddset(&mask, SIGWINCH) == 0); /* Kernel sends us this on kbrequest (alt-arrowup) */
  52         assert_se(sigaddset(&mask, SIGTERM) == 0);
  53         assert_se(sigaddset(&mask, SIGHUP) == 0);
  54         assert_se(sigaddset(&mask, SIGUSR1) == 0);
  55         assert_se(sigaddset(&mask, SIGUSR2) == 0);
  56         assert_se(sigaddset(&mask, SIGPIPE) == 0);
  57         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
  58
  59         m->signal_watch.type = WATCH_SIGNAL;
  60         if ((m->signal_watch.fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
  61                 return -errno;
  62
  63         zero(ev);
  64         ev.events = EPOLLIN;
  65         ev.data.ptr = &m->signal_watch;
  66
  67         if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_watch.fd, &ev) < 0)
  68                 return -errno;
  69
  70         return 0;
  71 }
  72
  73 static char** session_dirs(void) {
  74         const char *home, *e;
  75         char *config_home = NULL, *data_home = NULL;
  76         char **config_dirs = NULL, **data_dirs = NULL;
  77         char **r = NULL, **t;
  78
  79         /* Implement the mechanisms defined in
  80          *
  81          * http://standards.freedesktop.org/basedir-spec/basedir-spec-0.6.html
  82          *
  83          * We look in both the config and the data dirs because we
  84          * want to encourage that distributors ship their unit files
  85          * as data, and allow overriding as configuration.
  86          */
  87
  88         home = getenv("HOME");
  89
  90         if ((e = getenv("XDG_CONFIG_HOME"))) {
  91                 if (asprintf(&config_home, "%s/systemd/session", e) < 0)
  92                         goto fail;
  93
  94         } else if (home) {
  95                 if (asprintf(&config_home, "%s/.config/systemd/session", home) < 0)
  96                         goto fail;
  97         }
  98
  99         if ((e = getenv("XDG_CONFIG_DIRS")))
 100                 config_dirs = strv_split(e, ":");
 101         else
 102                 config_dirs = strv_new("/etc/xdg", NULL);
 103
 104         if (!config_dirs)
 105                 goto fail;
 106
 107         if ((e = getenv("XDG_DATA_HOME"))) {
 108                 if (asprintf(&data_home, "%s/systemd/session", e) < 0)
 109                         goto fail;
 110
 111         } else if (home) {
 112                 if (asprintf(&data_home, "%s/.local/share/systemd/session", home) < 0)
 113                         goto fail;
 114         }
 115
 116         if ((e = getenv("XDG_DATA_DIRS")))
 117                 data_dirs = strv_split(e, ":");
 118         else
 119                 data_dirs = strv_new("/usr/local/share", "/usr/share", NULL);
 120
 121         if (!data_dirs)
 122                 goto fail;
 123
 124         /* Now merge everything we found. */
 125         if (config_home) {
 126                 if (!(t = strv_append(r, config_home)))
 127                         goto fail;
 128                 strv_free(r);
 129                 r = t;
 130         }
 131
 132         if (!(t = strv_merge_concat(r, config_dirs, "/systemd/session")))
 133                 goto finish;
 134         strv_free(r);
 135         r = t;
 136
 137         if (!(t = strv_append(r, SESSION_CONFIG_UNIT_PATH)))
 138                 goto fail;
 139         strv_free(r);
 140         r = t;
 141
 142         if (data_home) {
 143                 if (!(t = strv_append(r, data_home)))
 144                         goto fail;
 145                 strv_free(r);
 146                 r = t;
 147         }
 148
 149         if (!(t = strv_merge_concat(r, data_dirs, "/systemd/session")))
 150                 goto fail;
 151         strv_free(r);
 152         r = t;
 153
 154         if (!(t = strv_append(r, SESSION_DATA_UNIT_PATH)))
 155                 goto fail;
 156         strv_free(r);
 157         r = t;
 158
 159         if (!strv_path_make_absolute_cwd(r))
 160             goto fail;
 161
 162 finish:
 163         free(config_home);
 164         strv_free(config_dirs);
 165         free(data_home);
 166         strv_free(data_dirs);
 167
 168         return r;
 169
 170 fail:
 171         strv_free(r);
 172         r = NULL;
 173         goto finish;
 174 }
 175
 176 static int manager_find_paths(Manager *m) {
 177         const char *e;
 178         char *t;
 179         assert(m);
 180
 181         /* First priority is whatever has been passed to us via env
 182          * vars */
 183         if ((e = getenv("SYSTEMD_UNIT_PATH")))
 184                 if (!(m->unit_path = split_path_and_make_absolute(e)))
 185                         return -ENOMEM;
 186
 187         if (strv_isempty(m->unit_path)) {
 188
 189                 /* Nothing is set, so let's figure something out. */
 190                 strv_free(m->unit_path);
 191
 192                 if (m->running_as == MANAGER_SESSION) {
 193                         if (!(m->unit_path = session_dirs()))
 194                                 return -ENOMEM;
 195                 } else
 196                         if (!(m->unit_path = strv_new(
 197                                               SYSTEM_CONFIG_UNIT_PATH,  /* /etc/systemd/system/ */
 198                                               SYSTEM_DATA_UNIT_PATH,    /* /lib/systemd/system/ */
 199                                               NULL)))
 200                                 return -ENOMEM;
 201         }
 202
 203         /* FIXME: This should probably look for MANAGER_INIT, and exclude MANAGER_SYSTEM */
 204         if (m->running_as != MANAGER_SESSION) {
 205                 /* /etc/init.d/ compativility does not matter to users */
 206
 207                 if ((e = getenv("SYSTEMD_SYSVINIT_PATH")))
 208                         if (!(m->sysvinit_path = split_path_and_make_absolute(e)))
 209                                 return -ENOMEM;
 210
 211                 if (strv_isempty(m->sysvinit_path)) {
 212                         strv_free(m->sysvinit_path);
 213
 214                         if (!(m->sysvinit_path = strv_new(
 215                                               SYSTEM_SYSVINIT_PATH,     /* /etc/init.d/ */
 216                                               NULL)))
 217                                 return -ENOMEM;
 218                 }
 219         }
 220
 221         strv_uniq(m->unit_path);
 222         strv_uniq(m->sysvinit_path);
 223
 224         assert(!strv_isempty(m->unit_path));
 225         if (!(t = strv_join(m->unit_path, "\n\t")))
 226                 return -ENOMEM;
 227         log_debug("Looking for unit files in:\n\t%s", t);
 228         free(t);
 229
 230         if (!strv_isempty(m->sysvinit_path)) {
 231
 232                 if (!(t = strv_join(m->sysvinit_path, "\n\t")))
 233                         return -ENOMEM;
 234
 235                 log_debug("Looking for SysV init scripts in:\n\t%s", t);
 236                 free(t);
 237         } else
 238                 log_debug("Ignoring SysV init scripts.");
 239
 240         return 0;
 241 }
 242
 243 Manager* manager_new(void) {
 244         Manager *m;
 245
 246         if (!(m = new0(Manager, 1)))
 247                 return NULL;
 248
 249         if (getpid() == 1)
 250                 m->running_as = MANAGER_INIT;
 251         else if (getuid() == 0)
 252                 m->running_as = MANAGER_SYSTEM;
 253         else
 254                 m->running_as = MANAGER_SESSION;
 255
 256         log_debug("systemd running in %s mode.", manager_running_as_to_string(m->running_as));
 257
 258         m->signal_watch.fd = m->mount_watch.fd = m->udev_watch.fd = m->epoll_fd = -1;
 259         m->current_job_id = 1; /* start as id #1, so that we can leave #0 around as "null-like" value */
 260
 261         if (manager_find_paths(m) < 0)
 262                 goto fail;
 263
 264         if (!(m->units = hashmap_new(string_hash_func, string_compare_func)))
 265                 goto fail;
 266
 267         if (!(m->jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
 268                 goto fail;
 269
 270         if (!(m->transaction_jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
 271                 goto fail;
 272
 273         if (!(m->watch_pids = hashmap_new(trivial_hash_func, trivial_compare_func)))
 274                 goto fail;
 275
 276         if ((m->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0)
 277                 goto fail;
 278
 279         if (manager_setup_signals(m) < 0)
 280                 goto fail;
 281
 282         /* FIXME: this should be called only when the D-Bus bus daemon is running */
 283         if (bus_init(m) < 0)
 284                 goto fail;
 285
 286         return m;
 287
 288 fail:
 289         manager_free(m);
 290         return NULL;
 291 }
 292
 293 void manager_free(Manager *m) {
 294         UnitType c;
 295         Unit *u;
 296         Job *j;
 297
 298         assert(m);
 299
 300         while ((j = hashmap_first(m->transaction_jobs)))
 301                 job_free(j);
 302
 303         while ((u = hashmap_first(m->units)))
 304                 unit_free(u);
 305
 306         for (c = 0; c < _UNIT_TYPE_MAX; c++)
 307                 if (unit_vtable[c]->shutdown)
 308                         unit_vtable[c]->shutdown(m);
 309
 310         bus_done(m);
 311
 312         hashmap_free(m->units);
 313         hashmap_free(m->jobs);
 314         hashmap_free(m->transaction_jobs);
 315         hashmap_free(m->watch_pids);
 316
 317         if (m->epoll_fd >= 0)
 318                 close_nointr(m->epoll_fd);
 319         if (m->signal_watch.fd >= 0)
 320                 close_nointr(m->signal_watch.fd);
 321
 322         strv_free(m->unit_path);
 323         strv_free(m->sysvinit_path);
 324
 325         free(m);
 326 }
 327
 328 int manager_coldplug(Manager *m) {
 329         int r;
 330         UnitType c;
 331         Iterator i;
 332         Unit *u;
 333         char *k;
 334
 335         assert(m);
 336
 337         /* First, let's ask every type to load all units from
 338          * disk/kernel that it might know */
 339         for (c = 0; c < _UNIT_TYPE_MAX; c++)
 340                 if (unit_vtable[c]->enumerate)
 341                         if ((r = unit_vtable[c]->enumerate(m)) < 0)
 342                                 return r;
 343
 344         manager_dispatch_load_queue(m);
 345
 346         /* Then, let's set up their initial state. */
 347         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
 348
 349                 /* ignore aliases */
 350                 if (unit_id(u) != k)
 351                         continue;
 352
 353                 if (UNIT_VTABLE(u)->coldplug)
 354                         if ((r = UNIT_VTABLE(u)->coldplug(u)) < 0)
 355                                 return r;
 356         }
 357
 358         return 0;
 359 }
 360
 361 static void transaction_delete_job(Manager *m, Job *j) {
 362         assert(m);
 363         assert(j);
 364
 365         /* Deletes one job from the transaction */
 366
 367         manager_transaction_unlink_job(m, j);
 368
 369         if (!j->installed)
 370                 job_free(j);
 371 }
 372
 373 static void transaction_delete_unit(Manager *m, Unit *u) {
 374         Job *j;
 375
 376         /* Deletes all jobs associated with a certain unit from the
 377          * transaction */
 378
 379         while ((j = hashmap_get(m->transaction_jobs, u)))
 380                 transaction_delete_job(m, j);
 381 }
 382
 383 static void transaction_clean_dependencies(Manager *m) {
 384         Iterator i;
 385         Job *j;
 386
 387         assert(m);
 388
 389         /* Drops all dependencies of all installed jobs */
 390
 391         HASHMAP_FOREACH(j, m->jobs, i) {
 392                 while (j->subject_list)
 393                         job_dependency_free(j->subject_list);
 394                 while (j->object_list)
 395                         job_dependency_free(j->object_list);
 396         }
 397
 398         assert(!m->transaction_anchor);
 399 }
 400
 401 static void transaction_abort(Manager *m) {
 402         Job *j;
 403
 404         assert(m);
 405
 406         while ((j = hashmap_first(m->transaction_jobs)))
 407                 if (j->installed)
 408                         transaction_delete_job(m, j);
 409                 else
 410                         job_free(j);
 411
 412         assert(hashmap_isempty(m->transaction_jobs));
 413
 414         transaction_clean_dependencies(m);
 415 }
 416
 417 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
 418         JobDependency *l;
 419
 420         assert(m);
 421
 422         /* A recursive sweep through the graph that marks all units
 423          * that matter to the anchor job, i.e. are directly or
 424          * indirectly a dependency of the anchor job via paths that
 425          * are fully marked as mattering. */
 426
 427         if (j)
 428                 l = j->subject_list;
 429         else
 430                 l = m->transaction_anchor;
 431
 432         LIST_FOREACH(subject, l, l) {
 433
 434                 /* This link does not matter */
 435                 if (!l->matters)
 436                         continue;
 437
 438                 /* This unit has already been marked */
 439                 if (l->object->generation == generation)
 440                         continue;
 441
 442                 l->object->matters_to_anchor = true;
 443                 l->object->generation = generation;
 444
 445                 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
 446         }
 447 }
 448
 449 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
 450         JobDependency *l, *last;
 451
 452         assert(j);
 453         assert(other);
 454         assert(j->unit == other->unit);
 455         assert(!j->installed);
 456
 457         /* Merges 'other' into 'j' and then deletes j. */
 458
 459         j->type = t;
 460         j->state = JOB_WAITING;
 461         j->forced = j->forced || other->forced;
 462
 463         j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
 464
 465         /* Patch us in as new owner of the JobDependency objects */
 466         last = NULL;
 467         LIST_FOREACH(subject, l, other->subject_list) {
 468                 assert(l->subject == other);
 469                 l->subject = j;
 470                 last = l;
 471         }
 472
 473         /* Merge both lists */
 474         if (last) {
 475                 last->subject_next = j->subject_list;
 476                 if (j->subject_list)
 477                         j->subject_list->subject_prev = last;
 478                 j->subject_list = other->subject_list;
 479         }
 480
 481         /* Patch us in as new owner of the JobDependency objects */
 482         last = NULL;
 483         LIST_FOREACH(object, l, other->object_list) {
 484                 assert(l->object == other);
 485                 l->object = j;
 486                 last = l;
 487         }
 488
 489         /* Merge both lists */
 490         if (last) {
 491                 last->object_next = j->object_list;
 492                 if (j->object_list)
 493                         j->object_list->object_prev = last;
 494                 j->object_list = other->object_list;
 495         }
 496
 497         /* Kill the other job */
 498         other->subject_list = NULL;
 499         other->object_list = NULL;
 500         transaction_delete_job(m, other);
 501 }
 502
 503 static int delete_one_unmergeable_job(Manager *m, Job *j) {
 504         Job *k;
 505
 506         assert(j);
 507
 508         /* Tries to delete one item in the linked list
 509          * j->transaction_next->transaction_next->... that conflicts
 510          * whith another one, in an attempt to make an inconsistent
 511          * transaction work. */
 512
 513         /* We rely here on the fact that if a merged with b does not
 514          * merge with c, either a or b merge with c neither */
 515         LIST_FOREACH(transaction, j, j)
 516                 LIST_FOREACH(transaction, k, j->transaction_next) {
 517                         Job *d;
 518
 519                         /* Is this one mergeable? Then skip it */
 520                         if (job_type_is_mergeable(j->type, k->type))
 521                                 continue;
 522
 523                         /* Ok, we found two that conflict, let's see if we can
 524                          * drop one of them */
 525                         if (!j->matters_to_anchor)
 526                                 d = j;
 527                         else if (!k->matters_to_anchor)
 528                                 d = k;
 529                         else
 530                                 return -ENOEXEC;
 531
 532                         /* Ok, we can drop one, so let's do so. */
 533                         log_debug("Try to fix job merging by deleting job %s/%s", unit_id(d->unit), job_type_to_string(d->type));
 534                         transaction_delete_job(m, d);
 535                         return 0;
 536                 }
 537
 538         return -EINVAL;
 539 }
 540
 541 static int transaction_merge_jobs(Manager *m) {
 542         Job *j;
 543         Iterator i;
 544         int r;
 545
 546         assert(m);
 547
 548         /* First step, check whether any of the jobs for one specific
 549          * task conflict. If so, try to drop one of them. */
 550         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 551                 JobType t;
 552                 Job *k;
 553
 554                 t = j->type;
 555                 LIST_FOREACH(transaction, k, j->transaction_next) {
 556                         if ((r = job_type_merge(&t, k->type)) >= 0)
 557                                 continue;
 558
 559                         /* OK, we could not merge all jobs for this
 560                          * action. Let's see if we can get rid of one
 561                          * of them */
 562
 563                         if ((r = delete_one_unmergeable_job(m, j)) >= 0)
 564                                 /* Ok, we managed to drop one, now
 565                                  * let's ask our callers to call us
 566                                  * again after garbage collecting */
 567                                 return -EAGAIN;
 568
 569                         /* We couldn't merge anything. Failure */
 570                         return r;
 571                 }
 572         }
 573
 574         /* Second step, merge the jobs. */
 575         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 576                 JobType t = j->type;
 577                 Job *k;
 578
 579                 /* Merge all transactions */
 580                 LIST_FOREACH(transaction, k, j->transaction_next)
 581                         assert_se(job_type_merge(&t, k->type) == 0);
 582
 583                 /* If an active job is mergeable, merge it too */
 584                 if (j->unit->meta.job)
 585                         job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
 586
 587                 while ((k = j->transaction_next)) {
 588                         if (j->installed) {
 589                                 transaction_merge_and_delete_job(m, k, j, t);
 590                                 j = k;
 591                         } else
 592                                 transaction_merge_and_delete_job(m, j, k, t);
 593                 }
 594
 595                 assert(!j->transaction_next);
 596                 assert(!j->transaction_prev);
 597         }
 598
 599         return 0;
 600 }
 601
 602 static bool unit_matters_to_anchor(Unit *u, Job *j) {
 603         assert(u);
 604         assert(!j->transaction_prev);
 605
 606         /* Checks whether at least one of the jobs for this unit
 607          * matters to the anchor. */
 608
 609         LIST_FOREACH(transaction, j, j)
 610                 if (j->matters_to_anchor)
 611                         return true;
 612
 613         return false;
 614 }
 615
 616 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation) {
 617         Iterator i;
 618         Unit *u;
 619         int r;
 620
 621         assert(m);
 622         assert(j);
 623         assert(!j->transaction_prev);
 624
 625         /* Does a recursive sweep through the ordering graph, looking
 626          * for a cycle. If we find cycle we try to break it. */
 627
 628         /* Did we find a cycle? */
 629         if (j->marker && j->generation == generation) {
 630                 Job *k;
 631
 632                 /* So, we already have been here. We have a
 633                  * cycle. Let's try to break it. We go backwards in
 634                  * our path and try to find a suitable job to
 635                  * remove. We use the marker to find our way back,
 636                  * since smart how we are we stored our way back in
 637                  * there. */
 638
 639                 log_debug("Found cycle on %s/%s", unit_id(j->unit), job_type_to_string(j->type));
 640
 641                 for (k = from; k; k = (k->generation == generation ? k->marker : NULL)) {
 642
 643                         log_debug("Walked on cycle path to %s/%s", unit_id(j->unit), job_type_to_string(j->type));
 644
 645                         if (!k->installed &&
 646                             !unit_matters_to_anchor(k->unit, k)) {
 647                                 /* Ok, we can drop this one, so let's
 648                                  * do so. */
 649                                 log_debug("Breaking order cycle by deleting job %s/%s", unit_id(k->unit), job_type_to_string(k->type));
 650                                 transaction_delete_unit(m, k->unit);
 651                                 return -EAGAIN;
 652                         }
 653
 654                         /* Check if this in fact was the beginning of
 655                          * the cycle */
 656                         if (k == j)
 657                                 break;
 658                 }
 659
 660                 log_debug("Unable to break cycle");
 661
 662                 return -ENOEXEC;
 663         }
 664
 665         /* Make the marker point to where we come from, so that we can
 666          * find our way backwards if we want to break a cycle */
 667         j->marker = from;
 668         j->generation = generation;
 669
 670         /* We assume that the the dependencies are bidirectional, and
 671          * hence can ignore UNIT_AFTER */
 672         SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
 673                 Job *o;
 674
 675                 /* Is there a job for this unit? */
 676                 if (!(o = hashmap_get(m->transaction_jobs, u)))
 677
 678                         /* Ok, there is no job for this in the
 679                          * transaction, but maybe there is already one
 680                          * running? */
 681                         if (!(o = u->meta.job))
 682                                 continue;
 683
 684                 if ((r = transaction_verify_order_one(m, o, j, generation)) < 0)
 685                         return r;
 686         }
 687
 688         /* Ok, let's backtrack, and remember that this entry is not on
 689          * our path anymore. */
 690         j->marker = NULL;
 691
 692         return 0;
 693 }
 694
 695 static int transaction_verify_order(Manager *m, unsigned *generation) {
 696         Job *j;
 697         int r;
 698         Iterator i;
 699
 700         assert(m);
 701         assert(generation);
 702
 703         /* Check if the ordering graph is cyclic. If it is, try to fix
 704          * that up by dropping one of the jobs. */
 705
 706         HASHMAP_FOREACH(j, m->transaction_jobs, i)
 707                 if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0)
 708                         return r;
 709
 710         return 0;
 711 }
 712
 713 static void transaction_collect_garbage(Manager *m) {
 714         bool again;
 715
 716         assert(m);
 717
 718         /* Drop jobs that are not required by any other job */
 719
 720         do {
 721                 Iterator i;
 722                 Job *j;
 723
 724                 again = false;
 725
 726                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 727                         if (j->object_list)
 728                                 continue;
 729
 730                         log_debug("Garbage collecting job %s/%s", unit_id(j->unit), job_type_to_string(j->type));
 731                         transaction_delete_job(m, j);
 732                         again = true;
 733                         break;
 734                 }
 735
 736         } while (again);
 737 }
 738
 739 static int transaction_is_destructive(Manager *m, JobMode mode) {
 740         Iterator i;
 741         Job *j;
 742
 743         assert(m);
 744
 745         /* Checks whether applying this transaction means that
 746          * existing jobs would be replaced */
 747
 748         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 749
 750                 /* Assume merged */
 751                 assert(!j->transaction_prev);
 752                 assert(!j->transaction_next);
 753
 754                 if (j->unit->meta.job &&
 755                     j->unit->meta.job != j &&
 756                     !job_type_is_superset(j->type, j->unit->meta.job->type))
 757                         return -EEXIST;
 758         }
 759
 760         return 0;
 761 }
 762
 763 static void transaction_minimize_impact(Manager *m) {
 764         bool again;
 765         assert(m);
 766
 767         /* Drops all unnecessary jobs that reverse already active jobs
 768          * or that stop a running service. */
 769
 770         do {
 771                 Job *j;
 772                 Iterator i;
 773
 774                 again = false;
 775
 776                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 777                         LIST_FOREACH(transaction, j, j) {
 778                                 bool stops_running_service, changes_existing_job;
 779
 780                                 /* If it matters, we shouldn't drop it */
 781                                 if (j->matters_to_anchor)
 782                                         continue;
 783
 784                                 /* Would this stop a running service?
 785                                  * Would this change an existing job?
 786                                  * If so, let's drop this entry */
 787
 788                                 stops_running_service =
 789                                         j->type == JOB_STOP && UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(j->unit));
 790
 791                                 changes_existing_job =
 792                                         j->unit->meta.job && job_type_is_conflicting(j->type, j->unit->meta.job->state);
 793
 794                                 if (!stops_running_service && !changes_existing_job)
 795                                         continue;
 796
 797                                 if (stops_running_service)
 798                                         log_debug("%s/%s would stop a running service.", unit_id(j->unit), job_type_to_string(j->type));
 799
 800                                 if (changes_existing_job)
 801                                         log_debug("%s/%s would change existing job.", unit_id(j->unit), job_type_to_string(j->type));
 802
 803                                 /* Ok, let's get rid of this */
 804                                 log_debug("Deleting %s/%s to minimize impact.", unit_id(j->unit), job_type_to_string(j->type));
 805
 806                                 transaction_delete_job(m, j);
 807                                 again = true;
 808                                 break;
 809                         }
 810
 811                         if (again)
 812                                 break;
 813                 }
 814
 815         } while (again);
 816 }
 817
 818 static int transaction_apply(Manager *m, JobMode mode) {
 819         Iterator i;
 820         Job *j;
 821         int r;
 822
 823         /* Moves the transaction jobs to the set of active jobs */
 824
 825         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 826                 /* Assume merged */
 827                 assert(!j->transaction_prev);
 828                 assert(!j->transaction_next);
 829
 830                 if (j->installed)
 831                         continue;
 832
 833                 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
 834                         goto rollback;
 835         }
 836
 837         while ((j = hashmap_steal_first(m->transaction_jobs))) {
 838                 if (j->installed)
 839                         continue;
 840
 841                 if (j->unit->meta.job)
 842                         job_free(j->unit->meta.job);
 843
 844                 j->unit->meta.job = j;
 845                 j->installed = true;
 846
 847                 /* We're fully installed. Now let's free data we don't
 848                  * need anymore. */
 849
 850                 assert(!j->transaction_next);
 851                 assert(!j->transaction_prev);
 852
 853                 job_add_to_run_queue(j);
 854                 job_add_to_dbus_queue(j);
 855         }
 856
 857         /* As last step, kill all remaining job dependencies. */
 858         transaction_clean_dependencies(m);
 859
 860         return 0;
 861
 862 rollback:
 863
 864         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 865                 if (j->installed)
 866                         continue;
 867
 868                 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
 869         }
 870
 871         return r;
 872 }
 873
 874 static int transaction_activate(Manager *m, JobMode mode) {
 875         int r;
 876         unsigned generation = 1;
 877
 878         assert(m);
 879
 880         /* This applies the changes recorded in transaction_jobs to
 881          * the actual list of jobs, if possible. */
 882
 883         /* First step: figure out which jobs matter */
 884         transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
 885
 886         /* Second step: Try not to stop any running services if
 887          * we don't have to. Don't try to reverse running
 888          * jobs if we don't have to. */
 889         transaction_minimize_impact(m);
 890
 891         for (;;) {
 892                 /* Third step: Let's remove unneeded jobs that might
 893                  * be lurking. */
 894                 transaction_collect_garbage(m);
 895
 896                 /* Fourth step: verify order makes sense and correct
 897                  * cycles if necessary and possible */
 898                 if ((r = transaction_verify_order(m, &generation)) >= 0)
 899                         break;
 900
 901                 if (r != -EAGAIN) {
 902                         log_debug("Requested transaction contains an unfixable cyclic ordering dependency: %s", strerror(-r));
 903                         goto rollback;
 904                 }
 905
 906                 /* Let's see if the resulting transaction ordering
 907                  * graph is still cyclic... */
 908         }
 909
 910         for (;;) {
 911                 /* Fifth step: let's drop unmergeable entries if
 912                  * necessary and possible, merge entries we can
 913                  * merge */
 914                 if ((r = transaction_merge_jobs(m)) >= 0)
 915                         break;
 916
 917                 if (r != -EAGAIN) {
 918                         log_debug("Requested transaction contains unmergable jobs: %s", strerror(-r));
 919                         goto rollback;
 920                 }
 921
 922                 /* Sixth step: an entry got dropped, let's garbage
 923                  * collect its dependencies. */
 924                 transaction_collect_garbage(m);
 925
 926                 /* Let's see if the resulting transaction still has
 927                  * unmergeable entries ... */
 928         }
 929
 930         /* Seventh step: check whether we can actually apply this */
 931         if (mode == JOB_FAIL)
 932                 if ((r = transaction_is_destructive(m, mode)) < 0) {
 933                         log_debug("Requested transaction contradicts existing jobs: %s", strerror(-r));
 934                         goto rollback;
 935                 }
 936
 937         /* Eights step: apply changes */
 938         if ((r = transaction_apply(m, mode)) < 0) {
 939                 log_debug("Failed to apply transaction: %s", strerror(-r));
 940                 goto rollback;
 941         }
 942
 943         assert(hashmap_isempty(m->transaction_jobs));
 944         assert(!m->transaction_anchor);
 945
 946         return 0;
 947
 948 rollback:
 949         transaction_abort(m);
 950         return r;
 951 }
 952
 953 static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool force, bool *is_new) {
 954         Job *j, *f;
 955         int r;
 956
 957         assert(m);
 958         assert(unit);
 959
 960         /* Looks for an axisting prospective job and returns that. If
 961          * it doesn't exist it is created and added to the prospective
 962          * jobs list. */
 963
 964         f = hashmap_get(m->transaction_jobs, unit);
 965
 966         LIST_FOREACH(transaction, j, f) {
 967                 assert(j->unit == unit);
 968
 969                 if (j->type == type) {
 970                         if (is_new)
 971                                 *is_new = false;
 972                         return j;
 973                 }
 974         }
 975
 976         if (unit->meta.job && unit->meta.job->type == type)
 977                 j = unit->meta.job;
 978         else if (!(j = job_new(m, type, unit)))
 979                 return NULL;
 980
 981         j->generation = 0;
 982         j->marker = NULL;
 983         j->matters_to_anchor = false;
 984         j->forced = force;
 985
 986         LIST_PREPEND(Job, transaction, f, j);
 987
 988         if ((r = hashmap_replace(m->transaction_jobs, unit, f)) < 0) {
 989                 job_free(j);
 990                 return NULL;
 991         }
 992
 993         if (is_new)
 994                 *is_new = true;
 995
 996         return j;
 997 }
 998
 999 void manager_transaction_unlink_job(Manager *m, Job *j) {
1000         assert(m);
1001         assert(j);
1002
1003         if (j->transaction_prev)
1004                 j->transaction_prev->transaction_next = j->transaction_next;
1005         else if (j->transaction_next)
1006                 hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
1007         else
1008                 hashmap_remove_value(m->transaction_jobs, j->unit, j);
1009
1010         if (j->transaction_next)
1011                 j->transaction_next->transaction_prev = j->transaction_prev;
1012
1013         j->transaction_prev = j->transaction_next = NULL;
1014
1015         while (j->subject_list)
1016                 job_dependency_free(j->subject_list);
1017
1018         while (j->object_list) {
1019                 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
1020
1021                 job_dependency_free(j->object_list);
1022
1023                 if (other) {
1024                         log_debug("Deleting job %s/%s as dependency of job %s/%s",
1025                                   unit_id(other->unit), job_type_to_string(other->type),
1026                                   unit_id(j->unit), job_type_to_string(j->type));
1027                         transaction_delete_job(m, other);
1028                 }
1029         }
1030 }
1031
1032 static int transaction_add_job_and_dependencies(Manager *m, JobType type, Unit *unit, Job *by, bool matters, bool force, Job **_ret) {
1033         Job *ret;
1034         Iterator i;
1035         Unit *dep;
1036         int r;
1037         bool is_new;
1038
1039         assert(m);
1040         assert(type < _JOB_TYPE_MAX);
1041         assert(unit);
1042
1043         if (unit->meta.load_state != UNIT_LOADED)
1044                 return -EINVAL;
1045
1046         if (!unit_job_is_applicable(unit, type))
1047                 return -EBADR;
1048
1049         /* First add the job. */
1050         if (!(ret = transaction_add_one_job(m, type, unit, force, &is_new)))
1051                 return -ENOMEM;
1052
1053         /* Then, add a link to the job. */
1054         if (!job_dependency_new(by, ret, matters))
1055                 return -ENOMEM;
1056
1057         if (is_new) {
1058                 /* Finally, recursively add in all dependencies. */
1059                 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
1060                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
1061                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
1062                                         goto fail;
1063                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUIRES], i)
1064                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
1065                                         goto fail;
1066                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
1067                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, force, NULL)) < 0 && r != -EBADR)
1068                                         goto fail;
1069                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
1070                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
1071                                         goto fail;
1072                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUISITE], i)
1073                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
1074                                         goto fail;
1075                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
1076                                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
1077                                         goto fail;
1078
1079                 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
1080
1081                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
1082                                 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
1083                                         goto fail;
1084                 }
1085
1086                 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
1087         }
1088
1089         if (_ret)
1090                 *_ret = ret;
1091
1092         return 0;
1093
1094 fail:
1095         return r;
1096 }
1097
1098 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool force, Job **_ret) {
1099         int r;
1100         Job *ret;
1101
1102         assert(m);
1103         assert(type < _JOB_TYPE_MAX);
1104         assert(unit);
1105         assert(mode < _JOB_MODE_MAX);
1106
1107         log_debug("Trying to enqueue job %s/%s", unit_id(unit), job_type_to_string(type));
1108
1109         if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, force, &ret)) < 0) {
1110                 transaction_abort(m);
1111                 return r;
1112         }
1113
1114         if ((r = transaction_activate(m, mode)) < 0)
1115                 return r;
1116
1117         log_debug("Enqueued job %s/%s as %u", unit_id(unit), job_type_to_string(type), (unsigned) ret->id);
1118
1119         if (_ret)
1120                 *_ret = ret;
1121
1122         return 0;
1123 }
1124
1125 Job *manager_get_job(Manager *m, uint32_t id) {
1126         assert(m);
1127
1128         return hashmap_get(m->jobs, UINT32_TO_PTR(id));
1129 }
1130
1131 Unit *manager_get_unit(Manager *m, const char *name) {
1132         assert(m);
1133         assert(name);
1134
1135         return hashmap_get(m->units, name);
1136 }
1137
1138 unsigned manager_dispatch_load_queue(Manager *m) {
1139         Meta *meta;
1140         unsigned n = 0;
1141
1142         assert(m);
1143
1144         /* Make sure we are not run recursively */
1145         if (m->dispatching_load_queue)
1146                 return 0;
1147
1148         m->dispatching_load_queue = true;
1149
1150         /* Dispatches the load queue. Takes a unit from the queue and
1151          * tries to load its data until the queue is empty */
1152
1153         while ((meta = m->load_queue)) {
1154                 assert(meta->in_load_queue);
1155
1156                 unit_load(UNIT(meta));
1157                 n++;
1158         }
1159
1160         m->dispatching_load_queue = false;
1161         return n;
1162 }
1163
1164 int manager_load_unit(Manager *m, const char *path, Unit **_ret) {
1165         Unit *ret;
1166         int r;
1167         const char *name;
1168
1169         assert(m);
1170         assert(path);
1171         assert(_ret);
1172
1173         /* This will load the service information files, but not actually
1174          * start any services or anything. */
1175
1176         name = file_name_from_path(path);
1177
1178         if ((ret = manager_get_unit(m, name))) {
1179                 *_ret = ret;
1180                 return 0;
1181         }
1182
1183         if (!(ret = unit_new(m)))
1184                 return -ENOMEM;
1185
1186         if (is_path(path)) {
1187                 if (!(ret->meta.fragment_path = strdup(path))) {
1188                         unit_free(ret);
1189                         return -ENOMEM;
1190                 }
1191         }
1192
1193         if ((r = unit_add_name(ret, name)) < 0) {
1194                 unit_free(ret);
1195                 return r;
1196         }
1197
1198         unit_add_to_load_queue(ret);
1199         unit_add_to_dbus_queue(ret);
1200
1201         manager_dispatch_load_queue(m);
1202
1203         *_ret = ret;
1204         return 0;
1205 }
1206
1207 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
1208         Iterator i;
1209         Job *j;
1210
1211         assert(s);
1212         assert(f);
1213
1214         HASHMAP_FOREACH(j, s->jobs, i)
1215                 job_dump(j, f, prefix);
1216 }
1217
1218 void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
1219         Iterator i;
1220         Unit *u;
1221         const char *t;
1222
1223         assert(s);
1224         assert(f);
1225
1226         HASHMAP_FOREACH_KEY(u, t, s->units, i)
1227                 if (unit_id(u) == t)
1228                         unit_dump(u, f, prefix);
1229 }
1230
1231 void manager_clear_jobs(Manager *m) {
1232         Job *j;
1233
1234         assert(m);
1235
1236         transaction_abort(m);
1237
1238         while ((j = hashmap_first(m->jobs)))
1239                 job_free(j);
1240 }
1241
1242 unsigned manager_dispatch_run_queue(Manager *m) {
1243         Job *j;
1244         unsigned n = 0;
1245
1246         if (m->dispatching_run_queue)
1247                 return 0;
1248
1249         m->dispatching_run_queue = true;
1250
1251         while ((j = m->run_queue)) {
1252                 assert(j->installed);
1253                 assert(j->in_run_queue);
1254
1255                 job_run_and_invalidate(j);
1256                 n++;
1257         }
1258
1259         m->dispatching_run_queue = false;
1260         return n;
1261 }
1262
1263 unsigned manager_dispatch_dbus_queue(Manager *m) {
1264         Job *j;
1265         Meta *meta;
1266         unsigned n = 0;
1267
1268         assert(m);
1269
1270         if (m->dispatching_dbus_queue)
1271                 return 0;
1272
1273         m->dispatching_dbus_queue = true;
1274
1275         while ((meta = m->dbus_unit_queue)) {
1276                 Unit *u = (Unit*) meta;
1277                 assert(u->meta.in_dbus_queue);
1278
1279                 bus_unit_send_change_signal(u);
1280                 n++;
1281         }
1282
1283         while ((j = m->dbus_job_queue)) {
1284                 assert(j->in_dbus_queue);
1285
1286                 bus_job_send_change_signal(j);
1287                 n++;
1288         }
1289
1290         m->dispatching_dbus_queue = false;
1291         return n;
1292 }
1293
1294 static int manager_dispatch_sigchld(Manager *m) {
1295         assert(m);
1296
1297         log_debug("dispatching SIGCHLD");
1298
1299         for (;;) {
1300                 siginfo_t si;
1301                 Unit *u;
1302
1303                 zero(si);
1304                 if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG) < 0) {
1305
1306                         if (errno == ECHILD)
1307                                 break;
1308
1309                         return -errno;
1310                 }
1311
1312                 if (si.si_pid == 0)
1313                         break;
1314
1315                 if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
1316                         continue;
1317
1318                 log_debug("child %llu died (code=%s, status=%i)", (long long unsigned) si.si_pid, sigchld_code_to_string(si.si_code), si.si_status);
1319
1320                 if (!(u = hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid))))
1321                         continue;
1322
1323                 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
1324         }
1325
1326         return 0;
1327 }
1328
1329 static int manager_process_signal_fd(Manager *m, bool *quit) {
1330         ssize_t n;
1331         struct signalfd_siginfo sfsi;
1332         bool sigchld = false;
1333
1334         assert(m);
1335
1336         for (;;) {
1337                 if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
1338
1339                         if (n >= 0)
1340                                 return -EIO;
1341
1342                         if (errno == EAGAIN)
1343                                 break;
1344
1345                         return -errno;
1346                 }
1347
1348                 switch (sfsi.ssi_signo) {
1349
1350                 case SIGCHLD:
1351                         sigchld = true;
1352                         break;
1353
1354                 case SIGINT:
1355                 case SIGTERM:
1356
1357                         if (m->running_as != MANAGER_INIT) {
1358                                 *quit = true;
1359                                 return 0;
1360
1361                         } else {
1362                                 Unit *target;
1363                                 int r;
1364
1365                                 if ((r = manager_load_unit(m, SPECIAL_CTRL_ALT_DEL_TARGET, &target)) < 0)
1366                                         log_error("Failed to load ctrl-alt-del target: %s", strerror(-r));
1367                                 else if ((r = manager_add_job(m, JOB_START, target, JOB_REPLACE, true, NULL)) < 0)
1368                                         log_error("Failed to enqueue ctrl-alt-del job: %s", strerror(-r));
1369
1370                                 break;
1371                         }
1372
1373                 case SIGWINCH:
1374
1375                         if (m->running_as == MANAGER_INIT) {
1376                                 Unit *target;
1377                                 int r;
1378
1379                                 if ((r = manager_load_unit(m, SPECIAL_KBREQUEST_TARGET, &target)) < 0)
1380                                         log_error("Failed to load kbrequest target: %s", strerror(-r));
1381                                 else if ((r = manager_add_job(m, JOB_START, target, JOB_REPLACE, true, NULL)) < 0)
1382                                         log_error("Failed to enqueue kbrequest job: %s", strerror(-r));
1383
1384                                 break;
1385                         }
1386
1387                         /* This is a nop on non-init systemd's */
1388
1389                         break;
1390
1391                 default:
1392                         log_info("Got unhandled signal <%s>.", strsignal(sfsi.ssi_signo));
1393                 }
1394         }
1395
1396         if (sigchld)
1397                 return manager_dispatch_sigchld(m);
1398
1399         return 0;
1400 }
1401
1402 static int process_event(Manager *m, struct epoll_event *ev, bool *quit) {
1403         int r;
1404         Watch *w;
1405
1406         assert(m);
1407         assert(ev);
1408
1409         assert(w = ev->data.ptr);
1410
1411         switch (w->type) {
1412
1413         case WATCH_SIGNAL:
1414
1415                 /* An incoming signal? */
1416                 if (ev->events != EPOLLIN)
1417                         return -EINVAL;
1418
1419                 if ((r = manager_process_signal_fd(m, quit)) < 0)
1420                         return r;
1421
1422                 break;
1423
1424         case WATCH_FD:
1425
1426                 /* Some fd event, to be dispatched to the units */
1427                 UNIT_VTABLE(w->data.unit)->fd_event(w->data.unit, w->fd, ev->events, w);
1428                 break;
1429
1430         case WATCH_TIMER: {
1431                 uint64_t v;
1432                 ssize_t k;
1433
1434                 /* Some timer event, to be dispatched to the units */
1435                 if ((k = read(w->fd, &v, sizeof(v))) != sizeof(v)) {
1436
1437                         if (k < 0 && (errno == EINTR || errno == EAGAIN))
1438                                 break;
1439
1440                         return k < 0 ? -errno : -EIO;
1441                 }
1442
1443                 UNIT_VTABLE(w->data.unit)->timer_event(w->data.unit, v, w);
1444                 break;
1445         }
1446
1447         case WATCH_MOUNT:
1448                 /* Some mount table change, intended for the mount subsystem */
1449                 mount_fd_event(m, ev->events);
1450                 break;
1451
1452         case WATCH_UDEV:
1453                 /* Some notification from udev, intended for the device subsystem */
1454                 device_fd_event(m, ev->events);
1455                 break;
1456
1457         case WATCH_DBUS_WATCH:
1458                 bus_watch_event(m, w, ev->events);
1459                 break;
1460
1461         case WATCH_DBUS_TIMEOUT:
1462                 bus_timeout_event(m, w, ev->events);
1463                 break;
1464
1465         default:
1466                 assert_not_reached("Unknown epoll event type.");
1467         }
1468
1469         return 0;
1470 }
1471
1472 int manager_loop(Manager *m) {
1473         int r;
1474         bool quit = false;
1475
1476         RATELIMIT_DEFINE(rl, 1*USEC_PER_SEC, 1000);
1477
1478         assert(m);
1479
1480         for (;;) {
1481                 struct epoll_event event;
1482                 int n;
1483
1484                 if (!ratelimit_test(&rl)) {
1485                         /* Yay, something is going seriously wrong, pause a little */
1486                         log_warning("Looping too fast. Throttling execution a little.");
1487                         sleep(1);
1488                 }
1489
1490                 if (manager_dispatch_load_queue(m) > 0)
1491                         continue;
1492
1493                 if (manager_dispatch_run_queue(m) > 0)
1494                         continue;
1495
1496                 if (bus_dispatch(m) > 0)
1497                         continue;
1498
1499                 if (manager_dispatch_dbus_queue(m) > 0)
1500                         continue;
1501
1502                 if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) {
1503
1504                         if (errno == -EINTR)
1505                                 continue;
1506
1507                         return -errno;
1508                 }
1509
1510                 assert(n == 1);
1511
1512                 if ((r = process_event(m, &event, &quit)) < 0)
1513                         return r;
1514
1515                 if (quit)
1516                         return 0;
1517         }
1518 }
1519
1520 int manager_get_unit_from_dbus_path(Manager *m, const char *s, Unit **_u) {
1521         char *n;
1522         Unit *u;
1523
1524         assert(m);
1525         assert(s);
1526         assert(_u);
1527
1528         if (!startswith(s, "/org/freedesktop/systemd1/unit/"))
1529                 return -EINVAL;
1530
1531         if (!(n = bus_path_unescape(s+31)))
1532                 return -ENOMEM;
1533
1534         u = manager_get_unit(m, n);
1535         free(n);
1536
1537         if (!u)
1538                 return -ENOENT;
1539
1540         *_u = u;
1541
1542         return 0;
1543 }
1544
1545 int manager_get_job_from_dbus_path(Manager *m, const char *s, Job **_j) {
1546         Job *j;
1547         unsigned id;
1548         int r;
1549
1550         assert(m);
1551         assert(s);
1552         assert(_j);
1553
1554         if (!startswith(s, "/org/freedesktop/systemd1/job/"))
1555                 return -EINVAL;
1556
1557         if ((r = safe_atou(s + 30, &id)) < 0)
1558                 return r;
1559
1560         if (!(j = manager_get_job(m, id)))
1561                 return -ENOENT;
1562
1563         *_j = j;
1564
1565         return 0;
1566 }
1567
1568 static const char* const manager_running_as_table[_MANAGER_RUNNING_AS_MAX] = {
1569         [MANAGER_INIT] = "init",
1570         [MANAGER_SYSTEM] = "system",
1571         [MANAGER_SESSION] = "session"
1572 };
1573
1574 DEFINE_STRING_TABLE_LOOKUP(manager_running_as, ManagerRunningAs);