src/manager.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   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 #include <sys/reboot.h>
  32 #include <sys/ioctl.h>
  33 #include <linux/kd.h>
  34 #include <termios.h>
  35 #include <fcntl.h>
  36 #include <sys/types.h>
  37 #include <sys/stat.h>
  38 #include <dirent.h>
  39
  40 #ifdef HAVE_AUDIT
  41 #include <libaudit.h>
  42 #endif
  43
  44 #include "manager.h"
  45 #include "hashmap.h"
  46 #include "macro.h"
  47 #include "strv.h"
  48 #include "log.h"
  49 #include "util.h"
  50 #include "ratelimit.h"
  51 #include "cgroup.h"
  52 #include "mount-setup.h"
  53 #include "unit-name.h"
  54 #include "dbus-unit.h"
  55 #include "dbus-job.h"
  56 #include "missing.h"
  57 #include "path-lookup.h"
  58 #include "special.h"
  59 #include "bus-errors.h"
  60 #include "exit-status.h"
  61
  62 /* As soon as 16 units are in our GC queue, make sure to run a gc sweep */
  63 #define GC_QUEUE_ENTRIES_MAX 16
  64
  65 /* As soon as 5s passed since a unit was added to our GC queue, make sure to run a gc sweep */
  66 #define GC_QUEUE_USEC_MAX (10*USEC_PER_SEC)
  67
  68 /* Where clients shall send notification messages to */
  69 #define NOTIFY_SOCKET "/org/freedesktop/systemd1/notify"
  70
  71 static int manager_setup_notify(Manager *m) {
  72         union {
  73                 struct sockaddr sa;
  74                 struct sockaddr_un un;
  75         } sa;
  76         struct epoll_event ev;
  77         int one = 1;
  78
  79         assert(m);
  80
  81         m->notify_watch.type = WATCH_NOTIFY;
  82         if ((m->notify_watch.fd = socket(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0)) < 0) {
  83                 log_error("Failed to allocate notification socket: %m");
  84                 return -errno;
  85         }
  86
  87         zero(sa);
  88         sa.sa.sa_family = AF_UNIX;
  89
  90         if (getpid() != 1)
  91                 snprintf(sa.un.sun_path+1, sizeof(sa.un.sun_path)-1, NOTIFY_SOCKET "/%llu", random_ull());
  92         else
  93                 strncpy(sa.un.sun_path+1, NOTIFY_SOCKET, sizeof(sa.un.sun_path)-1);
  94
  95         if (bind(m->notify_watch.fd, &sa.sa, sizeof(sa_family_t) + 1 + strlen(sa.un.sun_path+1)) < 0) {
  96                 log_error("bind() failed: %m");
  97                 return -errno;
  98         }
  99
 100         if (setsockopt(m->notify_watch.fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)) < 0) {
 101                 log_error("SO_PASSCRED failed: %m");
 102                 return -errno;
 103         }
 104
 105         zero(ev);
 106         ev.events = EPOLLIN;
 107         ev.data.ptr = &m->notify_watch;
 108
 109         if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->notify_watch.fd, &ev) < 0)
 110                 return -errno;
 111
 112         if (!(m->notify_socket = strdup(sa.un.sun_path+1)))
 113                 return -ENOMEM;
 114
 115         return 0;
 116 }
 117
 118 static int enable_special_signals(Manager *m) {
 119         char fd;
 120
 121         assert(m);
 122
 123         /* Enable that we get SIGINT on control-alt-del */
 124         if (reboot(RB_DISABLE_CAD) < 0)
 125                 log_warning("Failed to enable ctrl-alt-del handling: %m");
 126
 127         if ((fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY)) < 0)
 128                 log_warning("Failed to open /dev/tty0: %m");
 129         else {
 130                 /* Enable that we get SIGWINCH on kbrequest */
 131                 if (ioctl(fd, KDSIGACCEPT, SIGWINCH) < 0)
 132                         log_warning("Failed to enable kbrequest handling: %s", strerror(errno));
 133
 134                 close_nointr_nofail(fd);
 135         }
 136
 137         return 0;
 138 }
 139
 140 static int manager_setup_signals(Manager *m) {
 141         sigset_t mask;
 142         struct epoll_event ev;
 143         struct sigaction sa;
 144
 145         assert(m);
 146
 147         /* We are not interested in SIGSTOP and friends. */
 148         zero(sa);
 149         sa.sa_handler = SIG_DFL;
 150         sa.sa_flags = SA_NOCLDSTOP|SA_RESTART;
 151         assert_se(sigaction(SIGCHLD, &sa, NULL) == 0);
 152
 153         assert_se(sigemptyset(&mask) == 0);
 154
 155         sigset_add_many(&mask,
 156                         SIGCHLD,     /* Child died */
 157                         SIGTERM,     /* Reexecute daemon */
 158                         SIGHUP,      /* Reload configuration */
 159                         SIGUSR1,     /* systemd/upstart: reconnect to D-Bus */
 160                         SIGUSR2,     /* systemd: dump status */
 161                         SIGINT,      /* Kernel sends us this on control-alt-del */
 162                         SIGWINCH,    /* Kernel sends us this on kbrequest (alt-arrowup) */
 163                         SIGPWR,      /* Some kernel drivers and upsd send us this on power failure */
 164                         SIGRTMIN+0,  /* systemd: start default.target */
 165                         SIGRTMIN+1,  /* systemd: start rescue.target */
 166                         SIGRTMIN+2,  /* systemd: isolate emergency.target */
 167                         SIGRTMIN+3,  /* systemd: start halt.target */
 168                         SIGRTMIN+4,  /* systemd: start poweroff.target */
 169                         SIGRTMIN+5,  /* systemd: start reboot.target */
 170                         -1);
 171         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
 172
 173         m->signal_watch.type = WATCH_SIGNAL;
 174         if ((m->signal_watch.fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
 175                 return -errno;
 176
 177         zero(ev);
 178         ev.events = EPOLLIN;
 179         ev.data.ptr = &m->signal_watch;
 180
 181         if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_watch.fd, &ev) < 0)
 182                 return -errno;
 183
 184         if (m->running_as == MANAGER_SYSTEM)
 185                 return enable_special_signals(m);
 186
 187         return 0;
 188 }
 189
 190 int manager_new(ManagerRunningAs running_as, Manager **_m) {
 191         Manager *m;
 192         int r = -ENOMEM;
 193
 194         assert(_m);
 195         assert(running_as >= 0);
 196         assert(running_as < _MANAGER_RUNNING_AS_MAX);
 197
 198         if (!(m = new0(Manager, 1)))
 199                 return -ENOMEM;
 200
 201         dual_timestamp_get(&m->startup_timestamp);
 202
 203         m->running_as = running_as;
 204         m->name_data_slot = m->subscribed_data_slot = -1;
 205         m->exit_code = _MANAGER_EXIT_CODE_INVALID;
 206         m->pin_cgroupfs_fd = -1;
 207
 208 #ifdef HAVE_AUDIT
 209         m->audit_fd = -1;
 210 #endif
 211
 212         m->signal_watch.fd = m->mount_watch.fd = m->udev_watch.fd = m->epoll_fd = m->dev_autofs_fd = -1;
 213         m->current_job_id = 1; /* start as id #1, so that we can leave #0 around as "null-like" value */
 214
 215         if (!(m->environment = strv_copy(environ)))
 216                 goto fail;
 217
 218         if (!(m->units = hashmap_new(string_hash_func, string_compare_func)))
 219                 goto fail;
 220
 221         if (!(m->jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
 222                 goto fail;
 223
 224         if (!(m->transaction_jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
 225                 goto fail;
 226
 227         if (!(m->watch_pids = hashmap_new(trivial_hash_func, trivial_compare_func)))
 228                 goto fail;
 229
 230         if (!(m->cgroup_bondings = hashmap_new(string_hash_func, string_compare_func)))
 231                 goto fail;
 232
 233         if (!(m->watch_bus = hashmap_new(string_hash_func, string_compare_func)))
 234                 goto fail;
 235
 236         if ((m->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0)
 237                 goto fail;
 238
 239         if ((r = lookup_paths_init(&m->lookup_paths, m->running_as)) < 0)
 240                 goto fail;
 241
 242         if ((r = manager_setup_signals(m)) < 0)
 243                 goto fail;
 244
 245         if ((r = manager_setup_cgroup(m)) < 0)
 246                 goto fail;
 247
 248         if ((r = manager_setup_notify(m)) < 0)
 249                 goto fail;
 250
 251         /* Try to connect to the busses, if possible. */
 252         if ((r = bus_init(m)) < 0)
 253                 goto fail;
 254
 255 #ifdef HAVE_AUDIT
 256         if ((m->audit_fd = audit_open()) < 0)
 257                 log_error("Failed to connect to audit log: %m");
 258 #endif
 259
 260         *_m = m;
 261         return 0;
 262
 263 fail:
 264         manager_free(m);
 265         return r;
 266 }
 267
 268 static unsigned manager_dispatch_cleanup_queue(Manager *m) {
 269         Meta *meta;
 270         unsigned n = 0;
 271
 272         assert(m);
 273
 274         while ((meta = m->cleanup_queue)) {
 275                 assert(meta->in_cleanup_queue);
 276
 277                 unit_free((Unit*) meta);
 278                 n++;
 279         }
 280
 281         return n;
 282 }
 283
 284 enum {
 285         GC_OFFSET_IN_PATH,  /* This one is on the path we were travelling */
 286         GC_OFFSET_UNSURE,   /* No clue */
 287         GC_OFFSET_GOOD,     /* We still need this unit */
 288         GC_OFFSET_BAD,      /* We don't need this unit anymore */
 289         _GC_OFFSET_MAX
 290 };
 291
 292 static void unit_gc_sweep(Unit *u, unsigned gc_marker) {
 293         Iterator i;
 294         Unit *other;
 295         bool is_bad;
 296
 297         assert(u);
 298
 299         if (u->meta.gc_marker == gc_marker + GC_OFFSET_GOOD ||
 300             u->meta.gc_marker == gc_marker + GC_OFFSET_BAD ||
 301             u->meta.gc_marker == gc_marker + GC_OFFSET_IN_PATH)
 302                 return;
 303
 304         if (u->meta.in_cleanup_queue)
 305                 goto bad;
 306
 307         if (unit_check_gc(u))
 308                 goto good;
 309
 310         u->meta.gc_marker = gc_marker + GC_OFFSET_IN_PATH;
 311
 312         is_bad = true;
 313
 314         SET_FOREACH(other, u->meta.dependencies[UNIT_REFERENCED_BY], i) {
 315                 unit_gc_sweep(other, gc_marker);
 316
 317                 if (other->meta.gc_marker == gc_marker + GC_OFFSET_GOOD)
 318                         goto good;
 319
 320                 if (other->meta.gc_marker != gc_marker + GC_OFFSET_BAD)
 321                         is_bad = false;
 322         }
 323
 324         if (is_bad)
 325                 goto bad;
 326
 327         /* We were unable to find anything out about this entry, so
 328          * let's investigate it later */
 329         u->meta.gc_marker = gc_marker + GC_OFFSET_UNSURE;
 330         unit_add_to_gc_queue(u);
 331         return;
 332
 333 bad:
 334         /* We definitely know that this one is not useful anymore, so
 335          * let's mark it for deletion */
 336         u->meta.gc_marker = gc_marker + GC_OFFSET_BAD;
 337         unit_add_to_cleanup_queue(u);
 338         return;
 339
 340 good:
 341         u->meta.gc_marker = gc_marker + GC_OFFSET_GOOD;
 342 }
 343
 344 static unsigned manager_dispatch_gc_queue(Manager *m) {
 345         Meta *meta;
 346         unsigned n = 0;
 347         unsigned gc_marker;
 348
 349         assert(m);
 350
 351         if ((m->n_in_gc_queue < GC_QUEUE_ENTRIES_MAX) &&
 352             (m->gc_queue_timestamp <= 0 ||
 353              (m->gc_queue_timestamp + GC_QUEUE_USEC_MAX) > now(CLOCK_MONOTONIC)))
 354                 return 0;
 355
 356         log_debug("Running GC...");
 357
 358         m->gc_marker += _GC_OFFSET_MAX;
 359         if (m->gc_marker + _GC_OFFSET_MAX <= _GC_OFFSET_MAX)
 360                 m->gc_marker = 1;
 361
 362         gc_marker = m->gc_marker;
 363
 364         while ((meta = m->gc_queue)) {
 365                 assert(meta->in_gc_queue);
 366
 367                 unit_gc_sweep((Unit*) meta, gc_marker);
 368
 369                 LIST_REMOVE(Meta, gc_queue, m->gc_queue, meta);
 370                 meta->in_gc_queue = false;
 371
 372                 n++;
 373
 374                 if (meta->gc_marker == gc_marker + GC_OFFSET_BAD ||
 375                     meta->gc_marker == gc_marker + GC_OFFSET_UNSURE) {
 376                         log_debug("Collecting %s", meta->id);
 377                         meta->gc_marker = gc_marker + GC_OFFSET_BAD;
 378                         unit_add_to_cleanup_queue((Unit*) meta);
 379                 }
 380         }
 381
 382         m->n_in_gc_queue = 0;
 383         m->gc_queue_timestamp = 0;
 384
 385         return n;
 386 }
 387
 388 static void manager_clear_jobs_and_units(Manager *m) {
 389         Job *j;
 390         Unit *u;
 391
 392         assert(m);
 393
 394         while ((j = hashmap_first(m->transaction_jobs)))
 395                 job_free(j);
 396
 397         while ((u = hashmap_first(m->units)))
 398                 unit_free(u);
 399
 400         manager_dispatch_cleanup_queue(m);
 401
 402         assert(!m->load_queue);
 403         assert(!m->run_queue);
 404         assert(!m->dbus_unit_queue);
 405         assert(!m->dbus_job_queue);
 406         assert(!m->cleanup_queue);
 407         assert(!m->gc_queue);
 408
 409         assert(hashmap_isempty(m->transaction_jobs));
 410         assert(hashmap_isempty(m->jobs));
 411         assert(hashmap_isempty(m->units));
 412 }
 413
 414 void manager_free(Manager *m) {
 415         UnitType c;
 416
 417         assert(m);
 418
 419         manager_clear_jobs_and_units(m);
 420
 421         for (c = 0; c < _UNIT_TYPE_MAX; c++)
 422                 if (unit_vtable[c]->shutdown)
 423                         unit_vtable[c]->shutdown(m);
 424
 425         /* If we reexecute ourselves, we keep the root cgroup
 426          * around */
 427         manager_shutdown_cgroup(m, m->exit_code != MANAGER_REEXECUTE);
 428
 429         bus_done(m);
 430
 431         hashmap_free(m->units);
 432         hashmap_free(m->jobs);
 433         hashmap_free(m->transaction_jobs);
 434         hashmap_free(m->watch_pids);
 435         hashmap_free(m->watch_bus);
 436
 437         if (m->epoll_fd >= 0)
 438                 close_nointr_nofail(m->epoll_fd);
 439         if (m->signal_watch.fd >= 0)
 440                 close_nointr_nofail(m->signal_watch.fd);
 441         if (m->notify_watch.fd >= 0)
 442                 close_nointr_nofail(m->notify_watch.fd);
 443
 444 #ifdef HAVE_AUDIT
 445         if (m->audit_fd >= 0)
 446                 audit_close(m->audit_fd);
 447 #endif
 448
 449         free(m->notify_socket);
 450
 451         lookup_paths_free(&m->lookup_paths);
 452         strv_free(m->environment);
 453
 454         hashmap_free(m->cgroup_bondings);
 455         set_free_free(m->unit_path_cache);
 456
 457         free(m);
 458 }
 459
 460 int manager_enumerate(Manager *m) {
 461         int r = 0, q;
 462         UnitType c;
 463
 464         assert(m);
 465
 466         /* Let's ask every type to load all units from disk/kernel
 467          * that it might know */
 468         for (c = 0; c < _UNIT_TYPE_MAX; c++)
 469                 if (unit_vtable[c]->enumerate)
 470                         if ((q = unit_vtable[c]->enumerate(m)) < 0)
 471                                 r = q;
 472
 473         manager_dispatch_load_queue(m);
 474         return r;
 475 }
 476
 477 int manager_coldplug(Manager *m) {
 478         int r = 0, q;
 479         Iterator i;
 480         Unit *u;
 481         char *k;
 482
 483         assert(m);
 484
 485         /* Then, let's set up their initial state. */
 486         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
 487
 488                 /* ignore aliases */
 489                 if (u->meta.id != k)
 490                         continue;
 491
 492                 if ((q = unit_coldplug(u)) < 0)
 493                         r = q;
 494         }
 495
 496         return r;
 497 }
 498
 499 static void manager_build_unit_path_cache(Manager *m) {
 500         char **i;
 501         DIR *d = NULL;
 502         int r;
 503
 504         assert(m);
 505
 506         set_free_free(m->unit_path_cache);
 507
 508         if (!(m->unit_path_cache = set_new(string_hash_func, string_compare_func))) {
 509                 log_error("Failed to allocate unit path cache.");
 510                 return;
 511         }
 512
 513         /* This simply builds a list of files we know exist, so that
 514          * we don't always have to go to disk */
 515
 516         STRV_FOREACH(i, m->lookup_paths.unit_path) {
 517                 struct dirent *de;
 518
 519                 if (!(d = opendir(*i))) {
 520                         log_error("Failed to open directory: %m");
 521                         continue;
 522                 }
 523
 524                 while ((de = readdir(d))) {
 525                         char *p;
 526
 527                         if (ignore_file(de->d_name))
 528                                 continue;
 529
 530                         if (asprintf(&p, "%s/%s", streq(*i, "/") ? "" : *i, de->d_name) < 0) {
 531                                 r = -ENOMEM;
 532                                 goto fail;
 533                         }
 534
 535                         if ((r = set_put(m->unit_path_cache, p)) < 0) {
 536                                 free(p);
 537                                 goto fail;
 538                         }
 539                 }
 540
 541                 closedir(d);
 542                 d = NULL;
 543         }
 544
 545         return;
 546
 547 fail:
 548         log_error("Failed to build unit path cache: %s", strerror(-r));
 549
 550         set_free_free(m->unit_path_cache);
 551         m->unit_path_cache = NULL;
 552
 553         if (d)
 554                 closedir(d);
 555 }
 556
 557 int manager_startup(Manager *m, FILE *serialization, FDSet *fds) {
 558         int r, q;
 559
 560         assert(m);
 561
 562         manager_build_unit_path_cache(m);
 563
 564         /* If we will deserialize make sure that during enumeration
 565          * this is already known, so we increase the counter here
 566          * already */
 567         if (serialization)
 568                 m->n_deserializing ++;
 569
 570         /* First, enumerate what we can from all config files */
 571         r = manager_enumerate(m);
 572
 573         /* Second, deserialize if there is something to deserialize */
 574         if (serialization)
 575                 if ((q = manager_deserialize(m, serialization, fds)) < 0)
 576                         r = q;
 577
 578         /* Third, fire things up! */
 579         if ((q = manager_coldplug(m)) < 0)
 580                 r = q;
 581
 582         if (serialization) {
 583                 assert(m->n_deserializing > 0);
 584                 m->n_deserializing --;
 585         }
 586
 587         return r;
 588 }
 589
 590 static void transaction_delete_job(Manager *m, Job *j, bool delete_dependencies) {
 591         assert(m);
 592         assert(j);
 593
 594         /* Deletes one job from the transaction */
 595
 596         manager_transaction_unlink_job(m, j, delete_dependencies);
 597
 598         if (!j->installed)
 599                 job_free(j);
 600 }
 601
 602 static void transaction_delete_unit(Manager *m, Unit *u) {
 603         Job *j;
 604
 605         /* Deletes all jobs associated with a certain unit from the
 606          * transaction */
 607
 608         while ((j = hashmap_get(m->transaction_jobs, u)))
 609                 transaction_delete_job(m, j, true);
 610 }
 611
 612 static void transaction_clean_dependencies(Manager *m) {
 613         Iterator i;
 614         Job *j;
 615
 616         assert(m);
 617
 618         /* Drops all dependencies of all installed jobs */
 619
 620         HASHMAP_FOREACH(j, m->jobs, i) {
 621                 while (j->subject_list)
 622                         job_dependency_free(j->subject_list);
 623                 while (j->object_list)
 624                         job_dependency_free(j->object_list);
 625         }
 626
 627         assert(!m->transaction_anchor);
 628 }
 629
 630 static void transaction_abort(Manager *m) {
 631         Job *j;
 632
 633         assert(m);
 634
 635         while ((j = hashmap_first(m->transaction_jobs)))
 636                 if (j->installed)
 637                         transaction_delete_job(m, j, true);
 638                 else
 639                         job_free(j);
 640
 641         assert(hashmap_isempty(m->transaction_jobs));
 642
 643         transaction_clean_dependencies(m);
 644 }
 645
 646 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
 647         JobDependency *l;
 648
 649         assert(m);
 650
 651         /* A recursive sweep through the graph that marks all units
 652          * that matter to the anchor job, i.e. are directly or
 653          * indirectly a dependency of the anchor job via paths that
 654          * are fully marked as mattering. */
 655
 656         if (j)
 657                 l = j->subject_list;
 658         else
 659                 l = m->transaction_anchor;
 660
 661         LIST_FOREACH(subject, l, l) {
 662
 663                 /* This link does not matter */
 664                 if (!l->matters)
 665                         continue;
 666
 667                 /* This unit has already been marked */
 668                 if (l->object->generation == generation)
 669                         continue;
 670
 671                 l->object->matters_to_anchor = true;
 672                 l->object->generation = generation;
 673
 674                 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
 675         }
 676 }
 677
 678 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
 679         JobDependency *l, *last;
 680
 681         assert(j);
 682         assert(other);
 683         assert(j->unit == other->unit);
 684         assert(!j->installed);
 685
 686         /* Merges 'other' into 'j' and then deletes j. */
 687
 688         j->type = t;
 689         j->state = JOB_WAITING;
 690         j->override = j->override || other->override;
 691
 692         j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
 693
 694         /* Patch us in as new owner of the JobDependency objects */
 695         last = NULL;
 696         LIST_FOREACH(subject, l, other->subject_list) {
 697                 assert(l->subject == other);
 698                 l->subject = j;
 699                 last = l;
 700         }
 701
 702         /* Merge both lists */
 703         if (last) {
 704                 last->subject_next = j->subject_list;
 705                 if (j->subject_list)
 706                         j->subject_list->subject_prev = last;
 707                 j->subject_list = other->subject_list;
 708         }
 709
 710         /* Patch us in as new owner of the JobDependency objects */
 711         last = NULL;
 712         LIST_FOREACH(object, l, other->object_list) {
 713                 assert(l->object == other);
 714                 l->object = j;
 715                 last = l;
 716         }
 717
 718         /* Merge both lists */
 719         if (last) {
 720                 last->object_next = j->object_list;
 721                 if (j->object_list)
 722                         j->object_list->object_prev = last;
 723                 j->object_list = other->object_list;
 724         }
 725
 726         /* Kill the other job */
 727         other->subject_list = NULL;
 728         other->object_list = NULL;
 729         transaction_delete_job(m, other, true);
 730 }
 731 static bool job_is_conflicted_by(Job *j) {
 732         JobDependency *l;
 733
 734         assert(j);
 735
 736         /* Returns true if this job is pulled in by a least one
 737          * ConflictedBy dependency. */
 738
 739         LIST_FOREACH(object, l, j->object_list)
 740                 if (l->conflicts)
 741                         return true;
 742
 743         return false;
 744 }
 745
 746 static int delete_one_unmergeable_job(Manager *m, Job *j) {
 747         Job *k;
 748
 749         assert(j);
 750
 751         /* Tries to delete one item in the linked list
 752          * j->transaction_next->transaction_next->... that conflicts
 753          * whith another one, in an attempt to make an inconsistent
 754          * transaction work. */
 755
 756         /* We rely here on the fact that if a merged with b does not
 757          * merge with c, either a or b merge with c neither */
 758         LIST_FOREACH(transaction, j, j)
 759                 LIST_FOREACH(transaction, k, j->transaction_next) {
 760                         Job *d;
 761
 762                         /* Is this one mergeable? Then skip it */
 763                         if (job_type_is_mergeable(j->type, k->type))
 764                                 continue;
 765
 766                         /* Ok, we found two that conflict, let's see if we can
 767                          * drop one of them */
 768                         if (!j->matters_to_anchor && !k->matters_to_anchor) {
 769
 770                                 /* Both jobs don't matter, so let's
 771                                  * find the one that is smarter to
 772                                  * remove. Let's think positive and
 773                                  * rather remove stops then starts --
 774                                  * except if something is being
 775                                  * stopped because it is conflicted by
 776                                  * another unit in which case we
 777                                  * rather remove the start. */
 778
 779                                 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)));
 780                                 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)));
 781
 782                                 if (j->type == JOB_STOP) {
 783
 784                                         if (job_is_conflicted_by(j))
 785                                                 d = k;
 786                                         else
 787                                                 d = j;
 788
 789                                 } else if (k->type == JOB_STOP) {
 790
 791                                         if (job_is_conflicted_by(k))
 792                                                 d = j;
 793                                         else
 794                                                 d = k;
 795                                 } else
 796                                         d = j;
 797
 798                         } else if (!j->matters_to_anchor)
 799                                 d = j;
 800                         else if (!k->matters_to_anchor)
 801                                 d = k;
 802                         else
 803                                 return -ENOEXEC;
 804
 805                         /* Ok, we can drop one, so let's do so. */
 806                         log_debug("Fixing conflicting jobs by deleting job %s/%s", d->unit->meta.id, job_type_to_string(d->type));
 807                         transaction_delete_job(m, d, true);
 808                         return 0;
 809                 }
 810
 811         return -EINVAL;
 812 }
 813
 814 static int transaction_merge_jobs(Manager *m, DBusError *e) {
 815         Job *j;
 816         Iterator i;
 817         int r;
 818
 819         assert(m);
 820
 821         /* First step, check whether any of the jobs for one specific
 822          * task conflict. If so, try to drop one of them. */
 823         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 824                 JobType t;
 825                 Job *k;
 826
 827                 t = j->type;
 828                 LIST_FOREACH(transaction, k, j->transaction_next) {
 829                         if (job_type_merge(&t, k->type) >= 0)
 830                                 continue;
 831
 832                         /* OK, we could not merge all jobs for this
 833                          * action. Let's see if we can get rid of one
 834                          * of them */
 835
 836                         if ((r = delete_one_unmergeable_job(m, j)) >= 0)
 837                                 /* Ok, we managed to drop one, now
 838                                  * let's ask our callers to call us
 839                                  * again after garbage collecting */
 840                                 return -EAGAIN;
 841
 842                         /* We couldn't merge anything. Failure */
 843                         dbus_set_error(e, BUS_ERROR_TRANSACTION_JOBS_CONFLICTING, "Transaction contains conflicting jobs '%s' and '%s' for %s. Probably contradicting requirement dependencies configured.",
 844                                        job_type_to_string(t), job_type_to_string(k->type), k->unit->meta.id);
 845                         return r;
 846                 }
 847         }
 848
 849         /* Second step, merge the jobs. */
 850         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 851                 JobType t = j->type;
 852                 Job *k;
 853
 854                 /* Merge all transactions */
 855                 LIST_FOREACH(transaction, k, j->transaction_next)
 856                         assert_se(job_type_merge(&t, k->type) == 0);
 857
 858                 /* If an active job is mergeable, merge it too */
 859                 if (j->unit->meta.job)
 860                         job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
 861
 862                 while ((k = j->transaction_next)) {
 863                         if (j->installed) {
 864                                 transaction_merge_and_delete_job(m, k, j, t);
 865                                 j = k;
 866                         } else
 867                                 transaction_merge_and_delete_job(m, j, k, t);
 868                 }
 869
 870                 assert(!j->transaction_next);
 871                 assert(!j->transaction_prev);
 872         }
 873
 874         return 0;
 875 }
 876
 877 static void transaction_drop_redundant(Manager *m) {
 878         bool again;
 879
 880         assert(m);
 881
 882         /* Goes through the transaction and removes all jobs that are
 883          * a noop */
 884
 885         do {
 886                 Job *j;
 887                 Iterator i;
 888
 889                 again = false;
 890
 891                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
 892                         bool changes_something = false;
 893                         Job *k;
 894
 895                         LIST_FOREACH(transaction, k, j) {
 896
 897                                 if (!job_is_anchor(k) &&
 898                                     job_type_is_redundant(k->type, unit_active_state(k->unit)))
 899                                         continue;
 900
 901                                 changes_something = true;
 902                                 break;
 903                         }
 904
 905                         if (changes_something)
 906                                 continue;
 907
 908                         log_debug("Found redundant job %s/%s, dropping.", j->unit->meta.id, job_type_to_string(j->type));
 909                         transaction_delete_job(m, j, false);
 910                         again = true;
 911                         break;
 912                 }
 913
 914         } while (again);
 915 }
 916
 917 static bool unit_matters_to_anchor(Unit *u, Job *j) {
 918         assert(u);
 919         assert(!j->transaction_prev);
 920
 921         /* Checks whether at least one of the jobs for this unit
 922          * matters to the anchor. */
 923
 924         LIST_FOREACH(transaction, j, j)
 925                 if (j->matters_to_anchor)
 926                         return true;
 927
 928         return false;
 929 }
 930
 931 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation, DBusError *e) {
 932         Iterator i;
 933         Unit *u;
 934         int r;
 935
 936         assert(m);
 937         assert(j);
 938         assert(!j->transaction_prev);
 939
 940         /* Does a recursive sweep through the ordering graph, looking
 941          * for a cycle. If we find cycle we try to break it. */
 942
 943         /* Have we seen this before? */
 944         if (j->generation == generation) {
 945                 Job *k, *delete;
 946
 947                 /* If the marker is NULL we have been here already and
 948                  * decided the job was loop-free from here. Hence
 949                  * shortcut things and return right-away. */
 950                 if (!j->marker)
 951                         return 0;
 952
 953                 /* So, the marker is not NULL and we already have been
 954                  * here. We have a cycle. Let's try to break it. We go
 955                  * backwards in our path and try to find a suitable
 956                  * job to remove. We use the marker to find our way
 957                  * back, since smart how we are we stored our way back
 958                  * in there. */
 959                 log_warning("Found ordering cycle on %s/%s", j->unit->meta.id, job_type_to_string(j->type));
 960
 961                 delete = NULL;
 962                 for (k = from; k; k = ((k->generation == generation && k->marker != k) ? k->marker : NULL)) {
 963
 964                         log_info("Walked on cycle path to %s/%s", k->unit->meta.id, job_type_to_string(k->type));
 965
 966                         if (!delete &&
 967                             !k->installed &&
 968                             !unit_matters_to_anchor(k->unit, k)) {
 969                                 /* Ok, we can drop this one, so let's
 970                                  * do so. */
 971                                 delete = k;
 972                         }
 973
 974                         /* Check if this in fact was the beginning of
 975                          * the cycle */
 976                         if (k == j)
 977                                 break;
 978                 }
 979
 980
 981                 if (delete) {
 982                         log_warning("Breaking ordering cycle by deleting job %s/%s", k->unit->meta.id, job_type_to_string(k->type));
 983                         transaction_delete_unit(m, delete->unit);
 984                         return -EAGAIN;
 985                 }
 986
 987                 log_error("Unable to break cycle");
 988
 989                 dbus_set_error(e, BUS_ERROR_TRANSACTION_ORDER_IS_CYCLIC, "Transaction order is cyclic. See logs for details.");
 990                 return -ENOEXEC;
 991         }
 992
 993         /* Make the marker point to where we come from, so that we can
 994          * find our way backwards if we want to break a cycle. We use
 995          * a special marker for the beginning: we point to
 996          * ourselves. */
 997         j->marker = from ? from : j;
 998         j->generation = generation;
 999
1000         /* We assume that the the dependencies are bidirectional, and
1001          * hence can ignore UNIT_AFTER */
1002         SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
1003                 Job *o;
1004
1005                 /* Is there a job for this unit? */
1006                 if (!(o = hashmap_get(m->transaction_jobs, u)))
1007
1008                         /* Ok, there is no job for this in the
1009                          * transaction, but maybe there is already one
1010                          * running? */
1011                         if (!(o = u->meta.job))
1012                                 continue;
1013
1014                 if ((r = transaction_verify_order_one(m, o, j, generation, e)) < 0)
1015                         return r;
1016         }
1017
1018         /* Ok, let's backtrack, and remember that this entry is not on
1019          * our path anymore. */
1020         j->marker = NULL;
1021
1022         return 0;
1023 }
1024
1025 static int transaction_verify_order(Manager *m, unsigned *generation, DBusError *e) {
1026         Job *j;
1027         int r;
1028         Iterator i;
1029         unsigned g;
1030
1031         assert(m);
1032         assert(generation);
1033
1034         /* Check if the ordering graph is cyclic. If it is, try to fix
1035          * that up by dropping one of the jobs. */
1036
1037         g = (*generation)++;
1038
1039         HASHMAP_FOREACH(j, m->transaction_jobs, i)
1040                 if ((r = transaction_verify_order_one(m, j, NULL, g, e)) < 0)
1041                         return r;
1042
1043         return 0;
1044 }
1045
1046 static void transaction_collect_garbage(Manager *m) {
1047         bool again;
1048
1049         assert(m);
1050
1051         /* Drop jobs that are not required by any other job */
1052
1053         do {
1054                 Iterator i;
1055                 Job *j;
1056
1057                 again = false;
1058
1059                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1060                         if (j->object_list)
1061                                 continue;
1062
1063                         log_debug("Garbage collecting job %s/%s", j->unit->meta.id, job_type_to_string(j->type));
1064                         transaction_delete_job(m, j, true);
1065                         again = true;
1066                         break;
1067                 }
1068
1069         } while (again);
1070 }
1071
1072 static int transaction_is_destructive(Manager *m, DBusError *e) {
1073         Iterator i;
1074         Job *j;
1075
1076         assert(m);
1077
1078         /* Checks whether applying this transaction means that
1079          * existing jobs would be replaced */
1080
1081         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1082
1083                 /* Assume merged */
1084                 assert(!j->transaction_prev);
1085                 assert(!j->transaction_next);
1086
1087                 if (j->unit->meta.job &&
1088                     j->unit->meta.job != j &&
1089                     !job_type_is_superset(j->type, j->unit->meta.job->type)) {
1090
1091                         dbus_set_error(e, BUS_ERROR_TRANSACTION_IS_DESTRUCTIVE, "Transaction is destructive.");
1092                         return -EEXIST;
1093                 }
1094         }
1095
1096         return 0;
1097 }
1098
1099 static void transaction_minimize_impact(Manager *m) {
1100         bool again;
1101         assert(m);
1102
1103         /* Drops all unnecessary jobs that reverse already active jobs
1104          * or that stop a running service. */
1105
1106         do {
1107                 Job *j;
1108                 Iterator i;
1109
1110                 again = false;
1111
1112                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1113                         LIST_FOREACH(transaction, j, j) {
1114                                 bool stops_running_service, changes_existing_job;
1115
1116                                 /* If it matters, we shouldn't drop it */
1117                                 if (j->matters_to_anchor)
1118                                         continue;
1119
1120                                 /* Would this stop a running service?
1121                                  * Would this change an existing job?
1122                                  * If so, let's drop this entry */
1123
1124                                 stops_running_service =
1125                                         j->type == JOB_STOP && UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(j->unit));
1126
1127                                 changes_existing_job =
1128                                         j->unit->meta.job && job_type_is_conflicting(j->type, j->unit->meta.job->type);
1129
1130                                 if (!stops_running_service && !changes_existing_job)
1131                                         continue;
1132
1133                                 if (stops_running_service)
1134                                         log_info("%s/%s would stop a running service.", j->unit->meta.id, job_type_to_string(j->type));
1135
1136                                 if (changes_existing_job)
1137                                         log_info("%s/%s would change existing job.", j->unit->meta.id, job_type_to_string(j->type));
1138
1139                                 /* Ok, let's get rid of this */
1140                                 log_info("Deleting %s/%s to minimize impact.", j->unit->meta.id, job_type_to_string(j->type));
1141
1142                                 transaction_delete_job(m, j, true);
1143                                 again = true;
1144                                 break;
1145                         }
1146
1147                         if (again)
1148                                 break;
1149                 }
1150
1151         } while (again);
1152 }
1153
1154 static int transaction_apply(Manager *m) {
1155         Iterator i;
1156         Job *j;
1157         int r;
1158
1159         /* Moves the transaction jobs to the set of active jobs */
1160
1161         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1162                 /* Assume merged */
1163                 assert(!j->transaction_prev);
1164                 assert(!j->transaction_next);
1165
1166                 if (j->installed)
1167                         continue;
1168
1169                 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
1170                         goto rollback;
1171         }
1172
1173         while ((j = hashmap_steal_first(m->transaction_jobs))) {
1174                 if (j->installed)
1175                         continue;
1176
1177                 if (j->unit->meta.job)
1178                         job_free(j->unit->meta.job);
1179
1180                 j->unit->meta.job = j;
1181                 j->installed = true;
1182
1183                 /* We're fully installed. Now let's free data we don't
1184                  * need anymore. */
1185
1186                 assert(!j->transaction_next);
1187                 assert(!j->transaction_prev);
1188
1189                 job_add_to_run_queue(j);
1190                 job_add_to_dbus_queue(j);
1191                 job_start_timer(j);
1192         }
1193
1194         /* As last step, kill all remaining job dependencies. */
1195         transaction_clean_dependencies(m);
1196
1197         return 0;
1198
1199 rollback:
1200
1201         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1202                 if (j->installed)
1203                         continue;
1204
1205                 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
1206         }
1207
1208         return r;
1209 }
1210
1211 static int transaction_activate(Manager *m, JobMode mode, DBusError *e) {
1212         int r;
1213         unsigned generation = 1;
1214
1215         assert(m);
1216
1217         /* This applies the changes recorded in transaction_jobs to
1218          * the actual list of jobs, if possible. */
1219
1220         /* First step: figure out which jobs matter */
1221         transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
1222
1223         /* Second step: Try not to stop any running services if
1224          * we don't have to. Don't try to reverse running
1225          * jobs if we don't have to. */
1226         transaction_minimize_impact(m);
1227
1228         /* Third step: Drop redundant jobs */
1229         transaction_drop_redundant(m);
1230
1231         for (;;) {
1232                 /* Fourth step: Let's remove unneeded jobs that might
1233                  * be lurking. */
1234                 transaction_collect_garbage(m);
1235
1236                 /* Fifth step: verify order makes sense and correct
1237                  * cycles if necessary and possible */
1238                 if ((r = transaction_verify_order(m, &generation, e)) >= 0)
1239                         break;
1240
1241                 if (r != -EAGAIN) {
1242                         log_warning("Requested transaction contains an unfixable cyclic ordering dependency: %s", bus_error(e, r));
1243                         goto rollback;
1244                 }
1245
1246                 /* Let's see if the resulting transaction ordering
1247                  * graph is still cyclic... */
1248         }
1249
1250         for (;;) {
1251                 /* Sixth step: let's drop unmergeable entries if
1252                  * necessary and possible, merge entries we can
1253                  * merge */
1254                 if ((r = transaction_merge_jobs(m, e)) >= 0)
1255                         break;
1256
1257                 if (r != -EAGAIN) {
1258                         log_warning("Requested transaction contains unmergable jobs: %s", bus_error(e, r));
1259                         goto rollback;
1260                 }
1261
1262                 /* Seventh step: an entry got dropped, let's garbage
1263                  * collect its dependencies. */
1264                 transaction_collect_garbage(m);
1265
1266                 /* Let's see if the resulting transaction still has
1267                  * unmergeable entries ... */
1268         }
1269
1270         /* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */
1271         transaction_drop_redundant(m);
1272
1273         /* Ninth step: check whether we can actually apply this */
1274         if (mode == JOB_FAIL)
1275                 if ((r = transaction_is_destructive(m, e)) < 0) {
1276                         log_notice("Requested transaction contradicts existing jobs: %s", bus_error(e, r));
1277                         goto rollback;
1278                 }
1279
1280         /* Tenth step: apply changes */
1281         if ((r = transaction_apply(m)) < 0) {
1282                 log_warning("Failed to apply transaction: %s", strerror(-r));
1283                 goto rollback;
1284         }
1285
1286         assert(hashmap_isempty(m->transaction_jobs));
1287         assert(!m->transaction_anchor);
1288
1289         return 0;
1290
1291 rollback:
1292         transaction_abort(m);
1293         return r;
1294 }
1295
1296 static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool override, bool *is_new) {
1297         Job *j, *f;
1298
1299         assert(m);
1300         assert(unit);
1301
1302         /* Looks for an axisting prospective job and returns that. If
1303          * it doesn't exist it is created and added to the prospective
1304          * jobs list. */
1305
1306         f = hashmap_get(m->transaction_jobs, unit);
1307
1308         LIST_FOREACH(transaction, j, f) {
1309                 assert(j->unit == unit);
1310
1311                 if (j->type == type) {
1312                         if (is_new)
1313                                 *is_new = false;
1314                         return j;
1315                 }
1316         }
1317
1318         if (unit->meta.job && unit->meta.job->type == type)
1319                 j = unit->meta.job;
1320         else if (!(j = job_new(m, type, unit)))
1321                 return NULL;
1322
1323         j->generation = 0;
1324         j->marker = NULL;
1325         j->matters_to_anchor = false;
1326         j->override = override;
1327
1328         LIST_PREPEND(Job, transaction, f, j);
1329
1330         if (hashmap_replace(m->transaction_jobs, unit, f) < 0) {
1331                 job_free(j);
1332                 return NULL;
1333         }
1334
1335         if (is_new)
1336                 *is_new = true;
1337
1338         log_debug("Added job %s/%s to transaction.", unit->meta.id, job_type_to_string(type));
1339
1340         return j;
1341 }
1342
1343 void manager_transaction_unlink_job(Manager *m, Job *j, bool delete_dependencies) {
1344         assert(m);
1345         assert(j);
1346
1347         if (j->transaction_prev)
1348                 j->transaction_prev->transaction_next = j->transaction_next;
1349         else if (j->transaction_next)
1350                 hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
1351         else
1352                 hashmap_remove_value(m->transaction_jobs, j->unit, j);
1353
1354         if (j->transaction_next)
1355                 j->transaction_next->transaction_prev = j->transaction_prev;
1356
1357         j->transaction_prev = j->transaction_next = NULL;
1358
1359         while (j->subject_list)
1360                 job_dependency_free(j->subject_list);
1361
1362         while (j->object_list) {
1363                 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
1364
1365                 job_dependency_free(j->object_list);
1366
1367                 if (other && delete_dependencies) {
1368                         log_debug("Deleting job %s/%s as dependency of job %s/%s",
1369                                   other->unit->meta.id, job_type_to_string(other->type),
1370                                   j->unit->meta.id, job_type_to_string(j->type));
1371                         transaction_delete_job(m, other, delete_dependencies);
1372                 }
1373         }
1374 }
1375
1376 static int transaction_add_job_and_dependencies(
1377                 Manager *m,
1378                 JobType type,
1379                 Unit *unit,
1380                 Job *by,
1381                 bool matters,
1382                 bool override,
1383                 bool conflicts,
1384                 DBusError *e,
1385                 Job **_ret) {
1386         Job *ret;
1387         Iterator i;
1388         Unit *dep;
1389         int r;
1390         bool is_new;
1391
1392         assert(m);
1393         assert(type < _JOB_TYPE_MAX);
1394         assert(unit);
1395
1396         if (unit->meta.load_state != UNIT_LOADED && unit->meta.load_state != UNIT_FAILED) {
1397                 dbus_set_error(e, BUS_ERROR_LOAD_FAILED, "Unit %s is not loaded properly.", unit->meta.id);
1398                 return -EINVAL;
1399         }
1400
1401         if (type != JOB_STOP && unit->meta.load_state == UNIT_FAILED) {
1402                 dbus_set_error(e, BUS_ERROR_LOAD_FAILED, "Unit %s failed to load: %s. You might find more information in the logs.",
1403                                unit->meta.id,
1404                                strerror(-unit->meta.load_error));
1405                 return -EINVAL;
1406         }
1407
1408         if (!unit_job_is_applicable(unit, type)) {
1409                 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);
1410                 return -EBADR;
1411         }
1412
1413         /* First add the job. */
1414         if (!(ret = transaction_add_one_job(m, type, unit, override, &is_new)))
1415                 return -ENOMEM;
1416
1417         /* Then, add a link to the job. */
1418         if (!job_dependency_new(by, ret, matters, conflicts))
1419                 return -ENOMEM;
1420
1421         if (is_new) {
1422                 /* Finally, recursively add in all dependencies. */
1423                 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
1424                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
1425                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, override, false, e, NULL)) < 0 && r != -EBADR)
1426                                         goto fail;
1427
1428                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
1429                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !override, override, false, e, NULL)) < 0 && r != -EBADR) {
1430                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, bus_error(e, r));
1431                                         dbus_error_free(e);
1432                                 }
1433
1434                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
1435                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, false, false, e, NULL)) < 0) {
1436                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, bus_error(e, r));
1437                                         dbus_error_free(e);
1438                                 }
1439
1440                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
1441                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, override, false, e, NULL)) < 0 && r != -EBADR)
1442                                         goto fail;
1443
1444                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE_OVERRIDABLE], i)
1445                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !override, override, false, e, NULL)) < 0 && r != -EBADR) {
1446                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, bus_error(e, r));
1447                                         dbus_error_free(e);
1448                                 }
1449
1450                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
1451                                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, override, true, e, NULL)) < 0 && r != -EBADR)
1452                                         goto fail;
1453
1454                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTED_BY], i)
1455                                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, override, false, e, NULL)) < 0 && r != -EBADR)
1456                                         goto fail;
1457
1458                 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
1459
1460                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
1461                                 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, override, false, e, NULL)) < 0 && r != -EBADR)
1462                                         goto fail;
1463                 }
1464
1465                 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
1466         }
1467
1468         if (_ret)
1469                 *_ret = ret;
1470
1471         return 0;
1472
1473 fail:
1474         return r;
1475 }
1476
1477 static int transaction_add_isolate_jobs(Manager *m) {
1478         Iterator i;
1479         Unit *u;
1480         char *k;
1481         int r;
1482
1483         assert(m);
1484
1485         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
1486
1487                 /* ignore aliases */
1488                 if (u->meta.id != k)
1489                         continue;
1490
1491                 if (UNIT_VTABLE(u)->no_isolate)
1492                         continue;
1493
1494                 /* No need to stop inactive jobs */
1495                 if (UNIT_IS_INACTIVE_OR_MAINTENANCE(unit_active_state(u)))
1496                         continue;
1497
1498                 /* Is there already something listed for this? */
1499                 if (hashmap_get(m->transaction_jobs, u))
1500                         continue;
1501
1502                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, u, NULL, true, false, false, NULL, NULL)) < 0)
1503                         log_warning("Cannot add isolate job for unit %s, ignoring: %s", u->meta.id, strerror(-r));
1504         }
1505
1506         return 0;
1507 }
1508
1509 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool override, DBusError *e, Job **_ret) {
1510         int r;
1511         Job *ret;
1512
1513         assert(m);
1514         assert(type < _JOB_TYPE_MAX);
1515         assert(unit);
1516         assert(mode < _JOB_MODE_MAX);
1517
1518         if (mode == JOB_ISOLATE && type != JOB_START) {
1519                 dbus_set_error(e, BUS_ERROR_INVALID_JOB_MODE, "Isolate is only valid for start.");
1520                 return -EINVAL;
1521         }
1522
1523         log_debug("Trying to enqueue job %s/%s", unit->meta.id, job_type_to_string(type));
1524
1525         if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, override, false, e, &ret)) < 0) {
1526                 transaction_abort(m);
1527                 return r;
1528         }
1529
1530         if (mode == JOB_ISOLATE)
1531                 if ((r = transaction_add_isolate_jobs(m)) < 0) {
1532                         transaction_abort(m);
1533                         return r;
1534                 }
1535
1536         if ((r = transaction_activate(m, mode, e)) < 0)
1537                 return r;
1538
1539         log_debug("Enqueued job %s/%s as %u", unit->meta.id, job_type_to_string(type), (unsigned) ret->id);
1540
1541         if (_ret)
1542                 *_ret = ret;
1543
1544         return 0;
1545 }
1546
1547 int manager_add_job_by_name(Manager *m, JobType type, const char *name, JobMode mode, bool override, DBusError *e, Job **_ret) {
1548         Unit *unit;
1549         int r;
1550
1551         assert(m);
1552         assert(type < _JOB_TYPE_MAX);
1553         assert(name);
1554         assert(mode < _JOB_MODE_MAX);
1555
1556         if ((r = manager_load_unit(m, name, NULL, NULL, &unit)) < 0)
1557                 return r;
1558
1559         return manager_add_job(m, type, unit, mode, override, e, _ret);
1560 }
1561
1562 Job *manager_get_job(Manager *m, uint32_t id) {
1563         assert(m);
1564
1565         return hashmap_get(m->jobs, UINT32_TO_PTR(id));
1566 }
1567
1568 Unit *manager_get_unit(Manager *m, const char *name) {
1569         assert(m);
1570         assert(name);
1571
1572         return hashmap_get(m->units, name);
1573 }
1574
1575 unsigned manager_dispatch_load_queue(Manager *m) {
1576         Meta *meta;
1577         unsigned n = 0;
1578
1579         assert(m);
1580
1581         /* Make sure we are not run recursively */
1582         if (m->dispatching_load_queue)
1583                 return 0;
1584
1585         m->dispatching_load_queue = true;
1586
1587         /* Dispatches the load queue. Takes a unit from the queue and
1588          * tries to load its data until the queue is empty */
1589
1590         while ((meta = m->load_queue)) {
1591                 assert(meta->in_load_queue);
1592
1593                 unit_load((Unit*) meta);
1594                 n++;
1595         }
1596
1597         m->dispatching_load_queue = false;
1598         return n;
1599 }
1600
1601 int manager_load_unit_prepare(Manager *m, const char *name, const char *path, DBusError *e, Unit **_ret) {
1602         Unit *ret;
1603         int r;
1604
1605         assert(m);
1606         assert(name || path);
1607
1608         /* This will prepare the unit for loading, but not actually
1609          * load anything from disk. */
1610
1611         if (path && !is_path(path)) {
1612                 dbus_set_error(e, BUS_ERROR_INVALID_PATH, "Path %s is not absolute.", path);
1613                 return -EINVAL;
1614         }
1615
1616         if (!name)
1617                 name = file_name_from_path(path);
1618
1619         if (!unit_name_is_valid(name)) {
1620                 dbus_set_error(e, BUS_ERROR_INVALID_NAME, "Unit name %s is not valid.", name);
1621                 return -EINVAL;
1622         }
1623
1624         if ((ret = manager_get_unit(m, name))) {
1625                 *_ret = ret;
1626                 return 1;
1627         }
1628
1629         if (!(ret = unit_new(m)))
1630                 return -ENOMEM;
1631
1632         if (path)
1633                 if (!(ret->meta.fragment_path = strdup(path))) {
1634                         unit_free(ret);
1635                         return -ENOMEM;
1636                 }
1637
1638         if ((r = unit_add_name(ret, name)) < 0) {
1639                 unit_free(ret);
1640                 return r;
1641         }
1642
1643         unit_add_to_load_queue(ret);
1644         unit_add_to_dbus_queue(ret);
1645         unit_add_to_gc_queue(ret);
1646
1647         if (_ret)
1648                 *_ret = ret;
1649
1650         return 0;
1651 }
1652
1653 int manager_load_unit(Manager *m, const char *name, const char *path, DBusError *e, Unit **_ret) {
1654         int r;
1655
1656         assert(m);
1657
1658         /* This will load the service information files, but not actually
1659          * start any services or anything. */
1660
1661         if ((r = manager_load_unit_prepare(m, name, path, e, _ret)) != 0)
1662                 return r;
1663
1664         manager_dispatch_load_queue(m);
1665
1666         if (_ret)
1667                 *_ret = unit_follow_merge(*_ret);
1668
1669         return 0;
1670 }
1671
1672 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
1673         Iterator i;
1674         Job *j;
1675
1676         assert(s);
1677         assert(f);
1678
1679         HASHMAP_FOREACH(j, s->jobs, i)
1680                 job_dump(j, f, prefix);
1681 }
1682
1683 void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
1684         Iterator i;
1685         Unit *u;
1686         const char *t;
1687
1688         assert(s);
1689         assert(f);
1690
1691         HASHMAP_FOREACH_KEY(u, t, s->units, i)
1692                 if (u->meta.id == t)
1693                         unit_dump(u, f, prefix);
1694 }
1695
1696 void manager_clear_jobs(Manager *m) {
1697         Job *j;
1698
1699         assert(m);
1700
1701         transaction_abort(m);
1702
1703         while ((j = hashmap_first(m->jobs)))
1704                 job_free(j);
1705 }
1706
1707 unsigned manager_dispatch_run_queue(Manager *m) {
1708         Job *j;
1709         unsigned n = 0;
1710
1711         if (m->dispatching_run_queue)
1712                 return 0;
1713
1714         m->dispatching_run_queue = true;
1715
1716         while ((j = m->run_queue)) {
1717                 assert(j->installed);
1718                 assert(j->in_run_queue);
1719
1720                 job_run_and_invalidate(j);
1721                 n++;
1722         }
1723
1724         m->dispatching_run_queue = false;
1725         return n;
1726 }
1727
1728 unsigned manager_dispatch_dbus_queue(Manager *m) {
1729         Job *j;
1730         Meta *meta;
1731         unsigned n = 0;
1732
1733         assert(m);
1734
1735         if (m->dispatching_dbus_queue)
1736                 return 0;
1737
1738         m->dispatching_dbus_queue = true;
1739
1740         while ((meta = m->dbus_unit_queue)) {
1741                 assert(meta->in_dbus_queue);
1742
1743                 bus_unit_send_change_signal((Unit*) meta);
1744                 n++;
1745         }
1746
1747         while ((j = m->dbus_job_queue)) {
1748                 assert(j->in_dbus_queue);
1749
1750                 bus_job_send_change_signal(j);
1751                 n++;
1752         }
1753
1754         m->dispatching_dbus_queue = false;
1755         return n;
1756 }
1757
1758 static int manager_process_notify_fd(Manager *m) {
1759         ssize_t n;
1760
1761         assert(m);
1762
1763         for (;;) {
1764                 char buf[4096];
1765                 struct msghdr msghdr;
1766                 struct iovec iovec;
1767                 struct ucred *ucred;
1768                 union {
1769                         struct cmsghdr cmsghdr;
1770                         uint8_t buf[CMSG_SPACE(sizeof(struct ucred))];
1771                 } control;
1772                 Unit *u;
1773                 char **tags;
1774
1775                 zero(iovec);
1776                 iovec.iov_base = buf;
1777                 iovec.iov_len = sizeof(buf)-1;
1778
1779                 zero(control);
1780                 zero(msghdr);
1781                 msghdr.msg_iov = &iovec;
1782                 msghdr.msg_iovlen = 1;
1783                 msghdr.msg_control = &control;
1784                 msghdr.msg_controllen = sizeof(control);
1785
1786                 if ((n = recvmsg(m->notify_watch.fd, &msghdr, MSG_DONTWAIT)) <= 0) {
1787                         if (n >= 0)
1788                                 return -EIO;
1789
1790                         if (errno == EAGAIN || errno == EINTR)
1791                                 break;
1792
1793                         return -errno;
1794                 }
1795
1796                 if (msghdr.msg_controllen < CMSG_LEN(sizeof(struct ucred)) ||
1797                     control.cmsghdr.cmsg_level != SOL_SOCKET ||
1798                     control.cmsghdr.cmsg_type != SCM_CREDENTIALS ||
1799                     control.cmsghdr.cmsg_len != CMSG_LEN(sizeof(struct ucred))) {
1800                         log_warning("Received notify message without credentials. Ignoring.");
1801                         continue;
1802                 }
1803
1804                 ucred = (struct ucred*) CMSG_DATA(&control.cmsghdr);
1805
1806                 if (!(u = hashmap_get(m->watch_pids, LONG_TO_PTR(ucred->pid))))
1807                         if (!(u = cgroup_unit_by_pid(m, ucred->pid))) {
1808                                 log_warning("Cannot find unit for notify message of PID %lu.", (unsigned long) ucred->pid);
1809                                 continue;
1810                         }
1811
1812                 assert((size_t) n < sizeof(buf));
1813                 buf[n] = 0;
1814                 if (!(tags = strv_split(buf, "\n\r")))
1815                         return -ENOMEM;
1816
1817                 log_debug("Got notification message for unit %s", u->meta.id);
1818
1819                 if (UNIT_VTABLE(u)->notify_message)
1820                         UNIT_VTABLE(u)->notify_message(u, ucred->pid, tags);
1821
1822                 strv_free(tags);
1823         }
1824
1825         return 0;
1826 }
1827
1828 static int manager_dispatch_sigchld(Manager *m) {
1829         assert(m);
1830
1831         for (;;) {
1832                 siginfo_t si;
1833                 Unit *u;
1834                 int r;
1835
1836                 zero(si);
1837
1838                 /* First we call waitd() for a PID and do not reap the
1839                  * zombie. That way we can still access /proc/$PID for
1840                  * it while it is a zombie. */
1841                 if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG|WNOWAIT) < 0) {
1842
1843                         if (errno == ECHILD)
1844                                 break;
1845
1846                         if (errno == EINTR)
1847                                 continue;
1848
1849                         return -errno;
1850                 }
1851
1852                 if (si.si_pid <= 0)
1853                         break;
1854
1855                 if (si.si_code == CLD_EXITED || si.si_code == CLD_KILLED || si.si_code == CLD_DUMPED) {
1856                         char *name = NULL;
1857
1858                         get_process_name(si.si_pid, &name);
1859                         log_debug("Got SIGCHLD for process %lu (%s)", (unsigned long) si.si_pid, strna(name));
1860                         free(name);
1861                 }
1862
1863                 /* Let's flush any message the dying child might still
1864                  * have queued for us. This ensures that the process
1865                  * still exists in /proc so that we can figure out
1866                  * which cgroup and hence unit it belongs to. */
1867                 if ((r = manager_process_notify_fd(m)) < 0)
1868                         return r;
1869
1870                 /* And now figure out the unit this belongs to */
1871                 if (!(u = hashmap_get(m->watch_pids, LONG_TO_PTR(si.si_pid))))
1872                         u = cgroup_unit_by_pid(m, si.si_pid);
1873
1874                 /* And now, we actually reap the zombie. */
1875                 if (waitid(P_PID, si.si_pid, &si, WEXITED) < 0) {
1876                         if (errno == EINTR)
1877                                 continue;
1878
1879                         return -errno;
1880                 }
1881
1882                 if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
1883                         continue;
1884
1885                 log_debug("Child %lu died (code=%s, status=%i/%s)",
1886                           (long unsigned) si.si_pid,
1887                           sigchld_code_to_string(si.si_code),
1888                           si.si_status,
1889                           strna(si.si_code == CLD_EXITED
1890                                 ? exit_status_to_string(si.si_status, EXIT_STATUS_FULL)
1891                                 : signal_to_string(si.si_status)));
1892
1893                 if (!u)
1894                         continue;
1895
1896                 log_debug("Child %lu belongs to %s", (long unsigned) si.si_pid, u->meta.id);
1897
1898                 hashmap_remove(m->watch_pids, LONG_TO_PTR(si.si_pid));
1899                 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
1900         }
1901
1902         return 0;
1903 }
1904
1905 static int manager_start_target(Manager *m, const char *name, JobMode mode) {
1906         int r;
1907         DBusError error;
1908
1909         dbus_error_init(&error);
1910
1911         log_info("Activating special unit %s", name);
1912
1913         if ((r = manager_add_job_by_name(m, JOB_START, name, mode, true, &error, NULL)) < 0)
1914                 log_error("Failed to enqueue %s job: %s", name, bus_error(&error, r));
1915
1916         dbus_error_free(&error);
1917
1918         return r;
1919 }
1920
1921 static int manager_process_signal_fd(Manager *m) {
1922         ssize_t n;
1923         struct signalfd_siginfo sfsi;
1924         bool sigchld = false;
1925
1926         assert(m);
1927
1928         for (;;) {
1929                 if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
1930
1931                         if (n >= 0)
1932                                 return -EIO;
1933
1934                         if (errno == EINTR || errno == EAGAIN)
1935                                 break;
1936
1937                         return -errno;
1938                 }
1939
1940                 log_debug("Received SIG%s", strna(signal_to_string(sfsi.ssi_signo)));
1941
1942                 switch (sfsi.ssi_signo) {
1943
1944                 case SIGCHLD:
1945                         sigchld = true;
1946                         break;
1947
1948                 case SIGTERM:
1949                         if (m->running_as == MANAGER_SYSTEM) {
1950                                 /* This is for compatibility with the
1951                                  * original sysvinit */
1952                                 m->exit_code = MANAGER_REEXECUTE;
1953                                 break;
1954                         }
1955
1956                         /* Fall through */
1957
1958                 case SIGINT:
1959                         if (m->running_as == MANAGER_SYSTEM) {
1960                                 manager_start_target(m, SPECIAL_CTRL_ALT_DEL_TARGET, JOB_REPLACE);
1961                                 break;
1962                         }
1963
1964                         /* Run the exit target if there is one, if not, just exit. */
1965                         if (manager_start_target(m, SPECIAL_EXIT_SERVICE, JOB_REPLACE) < 0) {
1966                                 m->exit_code = MANAGER_EXIT;
1967                                 return 0;
1968                         }
1969
1970                         break;
1971
1972                 case SIGWINCH:
1973                         if (m->running_as == MANAGER_SYSTEM)
1974                                 manager_start_target(m, SPECIAL_KBREQUEST_TARGET, JOB_REPLACE);
1975
1976                         /* This is a nop on non-init */
1977                         break;
1978
1979                 case SIGPWR:
1980                         if (m->running_as == MANAGER_SYSTEM)
1981                                 manager_start_target(m, SPECIAL_SIGPWR_TARGET, JOB_REPLACE);
1982
1983                         /* This is a nop on non-init */
1984                         break;
1985
1986                 case SIGUSR1: {
1987                         Unit *u;
1988
1989                         u = manager_get_unit(m, SPECIAL_DBUS_SERVICE);
1990
1991                         if (!u || UNIT_IS_ACTIVE_OR_RELOADING(unit_active_state(u))) {
1992                                 log_info("Trying to reconnect to bus...");
1993                                 bus_init(m);
1994                         }
1995
1996                         if (!u || !UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u))) {
1997                                 log_info("Loading D-Bus service...");
1998                                 manager_start_target(m, SPECIAL_DBUS_SERVICE, JOB_REPLACE);
1999                         }
2000
2001                         break;
2002                 }
2003
2004                 case SIGUSR2: {
2005                         FILE *f;
2006                         char *dump = NULL;
2007                         size_t size;
2008
2009                         if (!(f = open_memstream(&dump, &size))) {
2010                                 log_warning("Failed to allocate memory stream.");
2011                                 break;
2012                         }
2013
2014                         manager_dump_units(m, f, "\t");
2015                         manager_dump_jobs(m, f, "\t");
2016
2017                         if (ferror(f)) {
2018                                 fclose(f);
2019                                 free(dump);
2020                                 log_warning("Failed to write status stream");
2021                                 break;
2022                         }
2023
2024                         fclose(f);
2025                         log_dump(LOG_INFO, dump);
2026                         free(dump);
2027
2028                         break;
2029                 }
2030
2031                 case SIGHUP:
2032                         m->exit_code = MANAGER_RELOAD;
2033                         break;
2034
2035                 default: {
2036                         static const char * const table[] = {
2037                                 [0] = SPECIAL_DEFAULT_TARGET,
2038                                 [1] = SPECIAL_RESCUE_TARGET,
2039                                 [2] = SPECIAL_EMERGENCY_TARGET,
2040                                 [3] = SPECIAL_HALT_TARGET,
2041                                 [4] = SPECIAL_POWEROFF_TARGET,
2042                                 [5] = SPECIAL_REBOOT_TARGET
2043                         };
2044
2045                         if ((int) sfsi.ssi_signo >= SIGRTMIN+0 &&
2046                             (int) sfsi.ssi_signo < SIGRTMIN+(int) ELEMENTSOF(table)) {
2047                                 manager_start_target(m, table[sfsi.ssi_signo - SIGRTMIN],
2048                                                      (sfsi.ssi_signo == 1 || sfsi.ssi_signo == 2) ? JOB_ISOLATE : JOB_REPLACE);
2049                                 break;
2050                         }
2051
2052                         log_warning("Got unhandled signal <%s>.", strna(signal_to_string(sfsi.ssi_signo)));
2053                 }
2054                 }
2055         }
2056
2057         if (sigchld)
2058                 return manager_dispatch_sigchld(m);
2059
2060         return 0;
2061 }
2062
2063 static int process_event(Manager *m, struct epoll_event *ev) {
2064         int r;
2065         Watch *w;
2066
2067         assert(m);
2068         assert(ev);
2069
2070         assert(w = ev->data.ptr);
2071
2072         switch (w->type) {
2073
2074         case WATCH_SIGNAL:
2075
2076                 /* An incoming signal? */
2077                 if (ev->events != EPOLLIN)
2078                         return -EINVAL;
2079
2080                 if ((r = manager_process_signal_fd(m)) < 0)
2081                         return r;
2082
2083                 break;
2084
2085         case WATCH_NOTIFY:
2086
2087                 /* An incoming daemon notification event? */
2088                 if (ev->events != EPOLLIN)
2089                         return -EINVAL;
2090
2091                 if ((r = manager_process_notify_fd(m)) < 0)
2092                         return r;
2093
2094                 break;
2095
2096         case WATCH_FD:
2097
2098                 /* Some fd event, to be dispatched to the units */
2099                 UNIT_VTABLE(w->data.unit)->fd_event(w->data.unit, w->fd, ev->events, w);
2100                 break;
2101
2102         case WATCH_UNIT_TIMER:
2103         case WATCH_JOB_TIMER: {
2104                 uint64_t v;
2105                 ssize_t k;
2106
2107                 /* Some timer event, to be dispatched to the units */
2108                 if ((k = read(w->fd, &v, sizeof(v))) != sizeof(v)) {
2109
2110                         if (k < 0 && (errno == EINTR || errno == EAGAIN))
2111                                 break;
2112
2113                         return k < 0 ? -errno : -EIO;
2114                 }
2115
2116                 if (w->type == WATCH_UNIT_TIMER)
2117                         UNIT_VTABLE(w->data.unit)->timer_event(w->data.unit, v, w);
2118                 else
2119                         job_timer_event(w->data.job, v, w);
2120                 break;
2121         }
2122
2123         case WATCH_MOUNT:
2124                 /* Some mount table change, intended for the mount subsystem */
2125                 mount_fd_event(m, ev->events);
2126                 break;
2127
2128         case WATCH_UDEV:
2129                 /* Some notification from udev, intended for the device subsystem */
2130                 device_fd_event(m, ev->events);
2131                 break;
2132
2133         case WATCH_DBUS_WATCH:
2134                 bus_watch_event(m, w, ev->events);
2135                 break;
2136
2137         case WATCH_DBUS_TIMEOUT:
2138                 bus_timeout_event(m, w, ev->events);
2139                 break;
2140
2141         default:
2142                 assert_not_reached("Unknown epoll event type.");
2143         }
2144
2145         return 0;
2146 }
2147
2148 int manager_loop(Manager *m) {
2149         int r;
2150
2151         RATELIMIT_DEFINE(rl, 1*USEC_PER_SEC, 1000);
2152
2153         assert(m);
2154         m->exit_code = MANAGER_RUNNING;
2155
2156         /* Release the path cache */
2157         set_free_free(m->unit_path_cache);
2158         m->unit_path_cache = NULL;
2159
2160         /* There might still be some zombies hanging around from
2161          * before we were exec()'ed. Leat's reap them */
2162         if ((r = manager_dispatch_sigchld(m)) < 0)
2163                 return r;
2164
2165         while (m->exit_code == MANAGER_RUNNING) {
2166                 struct epoll_event event;
2167                 int n;
2168
2169                 if (!ratelimit_test(&rl)) {
2170                         /* Yay, something is going seriously wrong, pause a little */
2171                         log_warning("Looping too fast. Throttling execution a little.");
2172                         sleep(1);
2173                 }
2174
2175                 if (manager_dispatch_load_queue(m) > 0)
2176                         continue;
2177
2178                 if (manager_dispatch_run_queue(m) > 0)
2179                         continue;
2180
2181                 if (bus_dispatch(m) > 0)
2182                         continue;
2183
2184                 if (manager_dispatch_cleanup_queue(m) > 0)
2185                         continue;
2186
2187                 if (manager_dispatch_gc_queue(m) > 0)
2188                         continue;
2189
2190                 if (manager_dispatch_dbus_queue(m) > 0)
2191                         continue;
2192
2193                 if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) {
2194
2195                         if (errno == EINTR)
2196                                 continue;
2197
2198                         return -errno;
2199                 }
2200
2201                 assert(n == 1);
2202
2203                 if ((r = process_event(m, &event)) < 0)
2204                         return r;
2205         }
2206
2207         return m->exit_code;
2208 }
2209
2210 int manager_get_unit_from_dbus_path(Manager *m, const char *s, Unit **_u) {
2211         char *n;
2212         Unit *u;
2213
2214         assert(m);
2215         assert(s);
2216         assert(_u);
2217
2218         if (!startswith(s, "/org/freedesktop/systemd1/unit/"))
2219                 return -EINVAL;
2220
2221         if (!(n = bus_path_unescape(s+31)))
2222                 return -ENOMEM;
2223
2224         u = manager_get_unit(m, n);
2225         free(n);
2226
2227         if (!u)
2228                 return -ENOENT;
2229
2230         *_u = u;
2231
2232         return 0;
2233 }
2234
2235 int manager_get_job_from_dbus_path(Manager *m, const char *s, Job **_j) {
2236         Job *j;
2237         unsigned id;
2238         int r;
2239
2240         assert(m);
2241         assert(s);
2242         assert(_j);
2243
2244         if (!startswith(s, "/org/freedesktop/systemd1/job/"))
2245                 return -EINVAL;
2246
2247         if ((r = safe_atou(s + 30, &id)) < 0)
2248                 return r;
2249
2250         if (!(j = manager_get_job(m, id)))
2251                 return -ENOENT;
2252
2253         *_j = j;
2254
2255         return 0;
2256 }
2257
2258 void manager_send_unit_audit(Manager *m, Unit *u, int type, bool success) {
2259
2260 #ifdef HAVE_AUDIT
2261         char *p;
2262
2263         if (m->audit_fd < 0)
2264                 return;
2265
2266         /* Don't generate audit events if the service was already
2267          * started and we're just deserializing */
2268         if (m->n_deserializing > 0)
2269                 return;
2270
2271         if (!(p = unit_name_to_prefix_and_instance(u->meta.id))) {
2272                 log_error("Failed to allocate unit name for audit message: %s", strerror(ENOMEM));
2273                 return;
2274         }
2275
2276         if (audit_log_user_comm_message(m->audit_fd, type, "", p, NULL, NULL, NULL, success) < 0)
2277                 log_error("Failed to send audit message: %m");
2278
2279         free(p);
2280 #endif
2281
2282 }
2283
2284 void manager_dispatch_bus_name_owner_changed(
2285                 Manager *m,
2286                 const char *name,
2287                 const char* old_owner,
2288                 const char *new_owner) {
2289
2290         Unit *u;
2291
2292         assert(m);
2293         assert(name);
2294
2295         if (!(u = hashmap_get(m->watch_bus, name)))
2296                 return;
2297
2298         UNIT_VTABLE(u)->bus_name_owner_change(u, name, old_owner, new_owner);
2299 }
2300
2301 void manager_dispatch_bus_query_pid_done(
2302                 Manager *m,
2303                 const char *name,
2304                 pid_t pid) {
2305
2306         Unit *u;
2307
2308         assert(m);
2309         assert(name);
2310         assert(pid >= 1);
2311
2312         if (!(u = hashmap_get(m->watch_bus, name)))
2313                 return;
2314
2315         UNIT_VTABLE(u)->bus_query_pid_done(u, name, pid);
2316 }
2317
2318 int manager_open_serialization(Manager *m, FILE **_f) {
2319         char *path;
2320         mode_t saved_umask;
2321         int fd;
2322         FILE *f;
2323
2324         assert(_f);
2325
2326         if (m->running_as == MANAGER_SYSTEM) {
2327                 mkdir_p("/dev/.systemd", 0755);
2328
2329                 if (asprintf(&path, "/dev/.systemd/dump-%lu-XXXXXX", (unsigned long) getpid()) < 0)
2330                         return -ENOMEM;
2331         } else {
2332                 if (asprintf(&path, "/tmp/systemd-dump-%lu-XXXXXX", (unsigned long) getpid()) < 0)
2333                         return -ENOMEM;
2334         }
2335
2336         saved_umask = umask(0077);
2337         fd = mkostemp(path, O_RDWR|O_CLOEXEC);
2338         umask(saved_umask);
2339
2340         if (fd < 0) {
2341                 free(path);
2342                 return -errno;
2343         }
2344
2345         unlink(path);
2346
2347         log_debug("Serializing state to %s", path);
2348         free(path);
2349
2350         if (!(f = fdopen(fd, "w+")) < 0)
2351                 return -errno;
2352
2353         *_f = f;
2354
2355         return 0;
2356 }
2357
2358 int manager_serialize(Manager *m, FILE *f, FDSet *fds) {
2359         Iterator i;
2360         Unit *u;
2361         const char *t;
2362         int r;
2363
2364         assert(m);
2365         assert(f);
2366         assert(fds);
2367
2368         fprintf(f, "startup-timestamp=%llu %llu\n\n",
2369                 (unsigned long long) m->startup_timestamp.realtime,
2370                 (unsigned long long) m->startup_timestamp.monotonic);
2371
2372         HASHMAP_FOREACH_KEY(u, t, m->units, i) {
2373                 if (u->meta.id != t)
2374                         continue;
2375
2376                 if (!unit_can_serialize(u))
2377                         continue;
2378
2379                 /* Start marker */
2380                 fputs(u->meta.id, f);
2381                 fputc('\n', f);
2382
2383                 if ((r = unit_serialize(u, f, fds)) < 0)
2384                         return r;
2385         }
2386
2387         if (ferror(f))
2388                 return -EIO;
2389
2390         return 0;
2391 }
2392
2393 int manager_deserialize(Manager *m, FILE *f, FDSet *fds) {
2394         int r = 0;
2395
2396         assert(m);
2397         assert(f);
2398
2399         log_debug("Deserializing state...");
2400
2401         m->n_deserializing ++;
2402
2403         for (;;) {
2404                 char line[1024], *l;
2405
2406                 if (!fgets(line, sizeof(line), f)) {
2407                         if (feof(f))
2408                                 r = 0;
2409                         else
2410                                 r = -errno;
2411
2412                         goto finish;
2413                 }
2414
2415                 char_array_0(line);
2416                 l = strstrip(line);
2417
2418                 if (l[0] == 0)
2419                         break;
2420
2421                 if (startswith(l, "startup-timestamp=")) {
2422                         unsigned long long a, b;
2423
2424                         if (sscanf(l+18, "%lli %llu", &a, &b) != 2)
2425                                 log_debug("Failed to parse startup timestamp value %s", l+18);
2426                         else {
2427                                 m->startup_timestamp.realtime = a;
2428                                 m->startup_timestamp.monotonic = b;
2429                         }
2430                 } else
2431                         log_debug("Unknown serialization item '%s'", l);
2432         }
2433
2434         for (;;) {
2435                 Unit *u;
2436                 char name[UNIT_NAME_MAX+2];
2437
2438                 /* Start marker */
2439                 if (!fgets(name, sizeof(name), f)) {
2440                         if (feof(f))
2441                                 r = 0;
2442                         else
2443                                 r = -errno;
2444
2445                         goto finish;
2446                 }
2447
2448                 char_array_0(name);
2449
2450                 if ((r = manager_load_unit(m, strstrip(name), NULL, NULL, &u)) < 0)
2451                         goto finish;
2452
2453                 if ((r = unit_deserialize(u, f, fds)) < 0)
2454                         goto finish;
2455         }
2456
2457 finish:
2458         if (ferror(f)) {
2459                 r = -EIO;
2460                 goto finish;
2461         }
2462
2463         assert(m->n_deserializing > 0);
2464         m->n_deserializing --;
2465
2466         return r;
2467 }
2468
2469 int manager_reload(Manager *m) {
2470         int r, q;
2471         FILE *f;
2472         FDSet *fds;
2473
2474         assert(m);
2475
2476         if ((r = manager_open_serialization(m, &f)) < 0)
2477                 return r;
2478
2479         if (!(fds = fdset_new())) {
2480                 r = -ENOMEM;
2481                 goto finish;
2482         }
2483
2484         if ((r = manager_serialize(m, f, fds)) < 0)
2485                 goto finish;
2486
2487         if (fseeko(f, 0, SEEK_SET) < 0) {
2488                 r = -errno;
2489                 goto finish;
2490         }
2491
2492         /* From here on there is no way back. */
2493         manager_clear_jobs_and_units(m);
2494
2495         /* Find new unit paths */
2496         lookup_paths_free(&m->lookup_paths);
2497         if ((q = lookup_paths_init(&m->lookup_paths, m->running_as)) < 0)
2498                 r = q;
2499
2500         m->n_deserializing ++;
2501
2502         /* First, enumerate what we can from all config files */
2503         if ((q = manager_enumerate(m)) < 0)
2504                 r = q;
2505
2506         /* Second, deserialize our stored data */
2507         if ((q = manager_deserialize(m, f, fds)) < 0)
2508                 r = q;
2509
2510         fclose(f);
2511         f = NULL;
2512
2513         /* Third, fire things up! */
2514         if ((q = manager_coldplug(m)) < 0)
2515                 r = q;
2516
2517         assert(m->n_deserializing > 0);
2518         m->n_deserializing ++;
2519
2520 finish:
2521         if (f)
2522                 fclose(f);
2523
2524         if (fds)
2525                 fdset_free(fds);
2526
2527         return r;
2528 }
2529
2530 bool manager_is_booting_or_shutting_down(Manager *m) {
2531         Unit *u;
2532
2533         assert(m);
2534
2535         /* Is the initial job still around? */
2536         if (manager_get_job(m, 1))
2537                 return true;
2538
2539         /* Is there a job for the shutdown target? */
2540         if (((u = manager_get_unit(m, SPECIAL_SHUTDOWN_TARGET))))
2541                 return !!u->meta.job;
2542
2543         return false;
2544 }
2545
2546 void manager_reset_maintenance(Manager *m) {
2547         Unit *u;
2548         Iterator i;
2549
2550         assert(m);
2551
2552         HASHMAP_FOREACH(u, m->units, i)
2553                 unit_reset_maintenance(u);
2554 }
2555
2556 static const char* const manager_running_as_table[_MANAGER_RUNNING_AS_MAX] = {
2557         [MANAGER_SYSTEM] = "system",
2558         [MANAGER_SESSION] = "session"
2559 };
2560
2561 DEFINE_STRING_TABLE_LOOKUP(manager_running_as, ManagerRunningAs);