chiark / gitweb /
namespace: make ro bind mounts work
[elogind.git] / manager.c
1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
2
3 /***
4   This file is part of systemd.
5
6   Copyright 2010 Lennart Poettering
7
8   systemd is free software; you can redistribute it and/or modify it
9   under the terms of the GNU General Public License as published by
10   the Free Software Foundation; either version 2 of the License, or
11   (at your option) any later version.
12
13   systemd is distributed in the hope that it will be useful, but
14   WITHOUT ANY WARRANTY; without even the implied warranty of
15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16   General Public License for more details.
17
18   You should have received a copy of the GNU General Public License
19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
20 ***/
21
22 #include <assert.h>
23 #include <errno.h>
24 #include <string.h>
25 #include <sys/epoll.h>
26 #include <signal.h>
27 #include <sys/signalfd.h>
28 #include <sys/wait.h>
29 #include <unistd.h>
30 #include <utmpx.h>
31 #include <sys/poll.h>
32 #include <sys/reboot.h>
33 #include <sys/ioctl.h>
34 #include <linux/kd.h>
35 #include <libcgroup.h>
36 #include <termios.h>
37 #include <fcntl.h>
38 #include <sys/types.h>
39 #include <sys/stat.h>
40
41 #include "manager.h"
42 #include "hashmap.h"
43 #include "macro.h"
44 #include "strv.h"
45 #include "log.h"
46 #include "util.h"
47 #include "ratelimit.h"
48 #include "cgroup.h"
49 #include "mount-setup.h"
50 #include "utmp-wtmp.h"
51 #include "unit-name.h"
52 #include "dbus-unit.h"
53 #include "dbus-job.h"
54
55 /* As soon as 16 units are in our GC queue, make sure to run a gc sweep */
56 #define GC_QUEUE_ENTRIES_MAX 16
57
58 /* As soon as 5s passed since a unit was added to our GC queue, make sure to run a gc sweep */
59 #define GC_QUEUE_USEC_MAX (5*USEC_PER_SEC)
60
61 static int enable_special_signals(Manager *m) {
62         char fd;
63
64         assert(m);
65
66         /* Enable that we get SIGINT on control-alt-del */
67         if (reboot(RB_DISABLE_CAD) < 0)
68                 log_warning("Failed to enable ctrl-alt-del handling: %m");
69
70         if ((fd = open_terminal("/dev/tty0", O_RDWR)) < 0)
71                 log_warning("Failed to open /dev/tty0: %m");
72         else {
73                 /* Enable that we get SIGWINCH on kbrequest */
74                 if (ioctl(fd, KDSIGACCEPT, SIGWINCH) < 0)
75                         log_warning("Failed to enable kbrequest handling: %s", strerror(errno));
76
77                 close_nointr_nofail(fd);
78         }
79
80         return 0;
81 }
82
83 static int manager_setup_signals(Manager *m) {
84         sigset_t mask;
85         struct epoll_event ev;
86         struct sigaction sa;
87
88         assert(m);
89
90         /* We are not interested in SIGSTOP and friends. */
91         zero(sa);
92         sa.sa_handler = SIG_DFL;
93         sa.sa_flags = SA_NOCLDSTOP|SA_RESTART;
94         assert_se(sigaction(SIGCHLD, &sa, NULL) == 0);
95
96         assert_se(sigemptyset(&mask) == 0);
97         assert_se(sigaddset(&mask, SIGCHLD) == 0);
98         assert_se(sigaddset(&mask, SIGTERM) == 0);
99         assert_se(sigaddset(&mask, SIGHUP) == 0);
100         assert_se(sigaddset(&mask, SIGUSR1) == 0);
101         assert_se(sigaddset(&mask, SIGUSR2) == 0);
102         assert_se(sigaddset(&mask, SIGINT) == 0);   /* Kernel sends us this on control-alt-del */
103         assert_se(sigaddset(&mask, SIGWINCH) == 0); /* Kernel sends us this on kbrequest (alt-arrowup) */
104         assert_se(sigaddset(&mask, SIGPWR) == 0);   /* Some kernel drivers and upsd send us this on power failure */
105         assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
106
107         m->signal_watch.type = WATCH_SIGNAL;
108         if ((m->signal_watch.fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
109                 return -errno;
110
111         zero(ev);
112         ev.events = EPOLLIN;
113         ev.data.ptr = &m->signal_watch;
114
115         if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_watch.fd, &ev) < 0)
116                 return -errno;
117
118         if (m->running_as == MANAGER_INIT)
119                 return enable_special_signals(m);
120
121         return 0;
122 }
123
124 static char** session_dirs(void) {
125         const char *home, *e;
126         char *config_home = NULL, *data_home = NULL;
127         char **config_dirs = NULL, **data_dirs = NULL;
128         char **r = NULL, **t;
129
130         /* Implement the mechanisms defined in
131          *
132          * http://standards.freedesktop.org/basedir-spec/basedir-spec-0.6.html
133          *
134          * We look in both the config and the data dirs because we
135          * want to encourage that distributors ship their unit files
136          * as data, and allow overriding as configuration.
137          */
138
139         home = getenv("HOME");
140
141         if ((e = getenv("XDG_CONFIG_HOME"))) {
142                 if (asprintf(&config_home, "%s/systemd/session", e) < 0)
143                         goto fail;
144
145         } else if (home) {
146                 if (asprintf(&config_home, "%s/.config/systemd/session", home) < 0)
147                         goto fail;
148         }
149
150         if ((e = getenv("XDG_CONFIG_DIRS")))
151                 config_dirs = strv_split(e, ":");
152         else
153                 config_dirs = strv_new("/etc/xdg", NULL);
154
155         if (!config_dirs)
156                 goto fail;
157
158         if ((e = getenv("XDG_DATA_HOME"))) {
159                 if (asprintf(&data_home, "%s/systemd/session", e) < 0)
160                         goto fail;
161
162         } else if (home) {
163                 if (asprintf(&data_home, "%s/.local/share/systemd/session", home) < 0)
164                         goto fail;
165         }
166
167         if ((e = getenv("XDG_DATA_DIRS")))
168                 data_dirs = strv_split(e, ":");
169         else
170                 data_dirs = strv_new("/usr/local/share", "/usr/share", NULL);
171
172         if (!data_dirs)
173                 goto fail;
174
175         /* Now merge everything we found. */
176         if (config_home) {
177                 if (!(t = strv_append(r, config_home)))
178                         goto fail;
179                 strv_free(r);
180                 r = t;
181         }
182
183         if (!(t = strv_merge_concat(r, config_dirs, "/systemd/session")))
184                 goto finish;
185         strv_free(r);
186         r = t;
187
188         if (!(t = strv_append(r, SESSION_CONFIG_UNIT_PATH)))
189                 goto fail;
190         strv_free(r);
191         r = t;
192
193         if (data_home) {
194                 if (!(t = strv_append(r, data_home)))
195                         goto fail;
196                 strv_free(r);
197                 r = t;
198         }
199
200         if (!(t = strv_merge_concat(r, data_dirs, "/systemd/session")))
201                 goto fail;
202         strv_free(r);
203         r = t;
204
205         if (!(t = strv_append(r, SESSION_DATA_UNIT_PATH)))
206                 goto fail;
207         strv_free(r);
208         r = t;
209
210         if (!strv_path_make_absolute_cwd(r))
211             goto fail;
212
213 finish:
214         free(config_home);
215         strv_free(config_dirs);
216         free(data_home);
217         strv_free(data_dirs);
218
219         return r;
220
221 fail:
222         strv_free(r);
223         r = NULL;
224         goto finish;
225 }
226
227 static int manager_find_paths(Manager *m) {
228         const char *e;
229         char *t;
230
231         assert(m);
232
233         /* First priority is whatever has been passed to us via env
234          * vars */
235         if ((e = getenv("SYSTEMD_UNIT_PATH")))
236                 if (!(m->unit_path = split_path_and_make_absolute(e)))
237                         return -ENOMEM;
238
239         if (strv_isempty(m->unit_path)) {
240
241                 /* Nothing is set, so let's figure something out. */
242                 strv_free(m->unit_path);
243
244                 if (m->running_as == MANAGER_SESSION) {
245                         if (!(m->unit_path = session_dirs()))
246                                 return -ENOMEM;
247                 } else
248                         if (!(m->unit_path = strv_new(
249                                               SYSTEM_CONFIG_UNIT_PATH,  /* /etc/systemd/system/ */
250                                               SYSTEM_DATA_UNIT_PATH,    /* /lib/systemd/system/ */
251                                               NULL)))
252                                 return -ENOMEM;
253         }
254
255         if (m->running_as == MANAGER_INIT) {
256                 /* /etc/init.d/ compativility does not matter to users */
257
258                 if ((e = getenv("SYSTEMD_SYSVINIT_PATH")))
259                         if (!(m->sysvinit_path = split_path_and_make_absolute(e)))
260                                 return -ENOMEM;
261
262                 if (strv_isempty(m->sysvinit_path)) {
263                         strv_free(m->sysvinit_path);
264
265                         if (!(m->sysvinit_path = strv_new(
266                                               SYSTEM_SYSVINIT_PATH,     /* /etc/init.d/ */
267                                               NULL)))
268                                 return -ENOMEM;
269                 }
270
271                 if ((e = getenv("SYSTEMD_SYSVRCND_PATH")))
272                         if (!(m->sysvrcnd_path = split_path_and_make_absolute(e)))
273                                 return -ENOMEM;
274
275                 if (strv_isempty(m->sysvrcnd_path)) {
276                         strv_free(m->sysvrcnd_path);
277
278                         if (!(m->sysvrcnd_path = strv_new(
279                                               SYSTEM_SYSVRCND_PATH,     /* /etc/rcN.d/ */
280                                               NULL)))
281                                 return -ENOMEM;
282                 }
283         }
284
285         strv_uniq(m->unit_path);
286         strv_uniq(m->sysvinit_path);
287         strv_uniq(m->sysvrcnd_path);
288
289         assert(!strv_isempty(m->unit_path));
290         if (!(t = strv_join(m->unit_path, "\n\t")))
291                 return -ENOMEM;
292         log_debug("Looking for unit files in:\n\t%s", t);
293         free(t);
294
295         if (!strv_isempty(m->sysvinit_path)) {
296
297                 if (!(t = strv_join(m->sysvinit_path, "\n\t")))
298                         return -ENOMEM;
299
300                 log_debug("Looking for SysV init scripts in:\n\t%s", t);
301                 free(t);
302         } else
303                 log_debug("Ignoring SysV init scripts.");
304
305         if (!strv_isempty(m->sysvrcnd_path)) {
306
307                 if (!(t = strv_join(m->sysvrcnd_path, "\n\t")))
308                         return -ENOMEM;
309
310                 log_debug("Looking for SysV rcN.d links in:\n\t%s", t);
311                 free(t);
312         } else
313                 log_debug("Ignoring SysV rcN.d links.");
314
315         return 0;
316 }
317
318 int manager_new(ManagerRunningAs running_as, bool confirm_spawn, Manager **_m) {
319         Manager *m;
320         int r = -ENOMEM;
321
322         assert(_m);
323         assert(running_as >= 0);
324         assert(running_as < _MANAGER_RUNNING_AS_MAX);
325
326         if (!(m = new0(Manager, 1)))
327                 return -ENOMEM;
328
329         m->boot_timestamp = now(CLOCK_REALTIME);
330
331         m->running_as = running_as;
332         m->confirm_spawn = confirm_spawn;
333         m->name_data_slot = -1;
334         m->exit_code = _MANAGER_EXIT_CODE_INVALID;
335
336         m->signal_watch.fd = m->mount_watch.fd = m->udev_watch.fd = m->epoll_fd = m->dev_autofs_fd = -1;
337         m->current_job_id = 1; /* start as id #1, so that we can leave #0 around as "null-like" value */
338
339         if (!(m->units = hashmap_new(string_hash_func, string_compare_func)))
340                 goto fail;
341
342         if (!(m->jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
343                 goto fail;
344
345         if (!(m->transaction_jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
346                 goto fail;
347
348         if (!(m->watch_pids = hashmap_new(trivial_hash_func, trivial_compare_func)))
349                 goto fail;
350
351         if (!(m->cgroup_bondings = hashmap_new(string_hash_func, string_compare_func)))
352                 goto fail;
353
354         if (!(m->watch_bus = hashmap_new(string_hash_func, string_compare_func)))
355                 goto fail;
356
357         if ((m->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0)
358                 goto fail;
359
360         if ((r = manager_find_paths(m)) < 0)
361                 goto fail;
362
363         if ((r = manager_setup_signals(m)) < 0)
364                 goto fail;
365
366         if ((r = manager_setup_cgroup(m)) < 0)
367                 goto fail;
368
369         /* Try to connect to the busses, if possible. */
370         if ((r = bus_init_system(m)) < 0 ||
371             (r = bus_init_api(m)) < 0)
372                 goto fail;
373
374         *_m = m;
375         return 0;
376
377 fail:
378         manager_free(m);
379         return r;
380 }
381
382 static unsigned manager_dispatch_cleanup_queue(Manager *m) {
383         Meta *meta;
384         unsigned n = 0;
385
386         assert(m);
387
388         while ((meta = m->cleanup_queue)) {
389                 assert(meta->in_cleanup_queue);
390
391                 unit_free(UNIT(meta));
392                 n++;
393         }
394
395         return n;
396 }
397
398 enum {
399         GC_OFFSET_IN_PATH,  /* This one is on the path we were travelling */
400         GC_OFFSET_UNSURE,   /* No clue */
401         GC_OFFSET_GOOD,     /* We still need this unit */
402         GC_OFFSET_BAD,      /* We don't need this unit anymore */
403         _GC_OFFSET_MAX
404 };
405
406 static void unit_gc_sweep(Unit *u, unsigned gc_marker) {
407         Iterator i;
408         Unit *other;
409         bool is_bad;
410
411         assert(u);
412
413         if (u->meta.gc_marker == gc_marker + GC_OFFSET_GOOD ||
414             u->meta.gc_marker == gc_marker + GC_OFFSET_BAD ||
415             u->meta.gc_marker == gc_marker + GC_OFFSET_IN_PATH)
416                 return;
417
418         if (u->meta.in_cleanup_queue)
419                 goto bad;
420
421         if (unit_check_gc(u))
422                 goto good;
423
424         u->meta.gc_marker = gc_marker + GC_OFFSET_IN_PATH;
425
426         is_bad = true;
427
428         SET_FOREACH(other, u->meta.dependencies[UNIT_REFERENCED_BY], i) {
429                 unit_gc_sweep(other, gc_marker);
430
431                 if (other->meta.gc_marker == gc_marker + GC_OFFSET_GOOD)
432                         goto good;
433
434                 if (other->meta.gc_marker != gc_marker + GC_OFFSET_BAD)
435                         is_bad = false;
436         }
437
438         if (is_bad)
439                 goto bad;
440
441         /* We were unable to find anything out about this entry, so
442          * let's investigate it later */
443         u->meta.gc_marker = gc_marker + GC_OFFSET_UNSURE;
444         unit_add_to_gc_queue(u);
445         return;
446
447 bad:
448         /* We definitely know that this one is not useful anymore, so
449          * let's mark it for deletion */
450         u->meta.gc_marker = gc_marker + GC_OFFSET_BAD;
451         unit_add_to_cleanup_queue(u);
452         return;
453
454 good:
455         u->meta.gc_marker = gc_marker + GC_OFFSET_GOOD;
456 }
457
458 static unsigned manager_dispatch_gc_queue(Manager *m) {
459         Meta *meta;
460         unsigned n = 0;
461         unsigned gc_marker;
462
463         assert(m);
464
465         if ((m->n_in_gc_queue < GC_QUEUE_ENTRIES_MAX) &&
466             (m->gc_queue_timestamp <= 0 ||
467              (m->gc_queue_timestamp + GC_QUEUE_USEC_MAX) > now(CLOCK_MONOTONIC)))
468                 return 0;
469
470         log_debug("Running GC...");
471
472         m->gc_marker += _GC_OFFSET_MAX;
473         if (m->gc_marker + _GC_OFFSET_MAX <= _GC_OFFSET_MAX)
474                 m->gc_marker = 1;
475
476         gc_marker = m->gc_marker;
477
478         while ((meta = m->gc_queue)) {
479                 assert(meta->in_gc_queue);
480
481                 unit_gc_sweep(UNIT(meta), gc_marker);
482
483                 LIST_REMOVE(Meta, gc_queue, m->gc_queue, meta);
484                 meta->in_gc_queue = false;
485
486                 n++;
487
488                 if (meta->gc_marker == gc_marker + GC_OFFSET_BAD ||
489                     meta->gc_marker == gc_marker + GC_OFFSET_UNSURE) {
490                         log_debug("Collecting %s", meta->id);
491                         meta->gc_marker = gc_marker + GC_OFFSET_BAD;
492                         unit_add_to_cleanup_queue(UNIT(meta));
493                 }
494         }
495
496         m->n_in_gc_queue = 0;
497         m->gc_queue_timestamp = 0;
498
499         return n;
500 }
501
502 static void manager_clear_jobs_and_units(Manager *m) {
503         Job *j;
504         Unit *u;
505
506         assert(m);
507
508         while ((j = hashmap_first(m->transaction_jobs)))
509                 job_free(j);
510
511         while ((u = hashmap_first(m->units)))
512                 unit_free(u);
513 }
514
515 void manager_free(Manager *m) {
516         UnitType c;
517
518         assert(m);
519
520         manager_clear_jobs_and_units(m);
521
522         for (c = 0; c < _UNIT_TYPE_MAX; c++)
523                 if (unit_vtable[c]->shutdown)
524                         unit_vtable[c]->shutdown(m);
525
526         /* If we reexecute ourselves, we keep the root cgroup
527          * around */
528         manager_shutdown_cgroup(m, m->exit_code != MANAGER_REEXECUTE);
529
530         bus_done_api(m);
531         bus_done_system(m);
532
533         hashmap_free(m->units);
534         hashmap_free(m->jobs);
535         hashmap_free(m->transaction_jobs);
536         hashmap_free(m->watch_pids);
537         hashmap_free(m->watch_bus);
538
539         if (m->epoll_fd >= 0)
540                 close_nointr_nofail(m->epoll_fd);
541         if (m->signal_watch.fd >= 0)
542                 close_nointr_nofail(m->signal_watch.fd);
543
544         strv_free(m->unit_path);
545         strv_free(m->sysvinit_path);
546         strv_free(m->sysvrcnd_path);
547
548         free(m->cgroup_controller);
549         free(m->cgroup_hierarchy);
550
551         hashmap_free(m->cgroup_bondings);
552
553         free(m);
554 }
555
556 int manager_enumerate(Manager *m) {
557         int r = 0, q;
558         UnitType c;
559
560         assert(m);
561
562         /* Let's ask every type to load all units from disk/kernel
563          * that it might know */
564         for (c = 0; c < _UNIT_TYPE_MAX; c++)
565                 if (unit_vtable[c]->enumerate)
566                         if ((q = unit_vtable[c]->enumerate(m)) < 0)
567                                 r = q;
568
569         manager_dispatch_load_queue(m);
570         return r;
571 }
572
573 int manager_coldplug(Manager *m) {
574         int r = 0, q;
575         Iterator i;
576         Unit *u;
577         char *k;
578
579         assert(m);
580
581         /* Then, let's set up their initial state. */
582         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
583
584                 /* ignore aliases */
585                 if (u->meta.id != k)
586                         continue;
587
588                 if (UNIT_VTABLE(u)->coldplug)
589                         if ((q = UNIT_VTABLE(u)->coldplug(u)) < 0)
590                                 r = q;
591         }
592
593         return r;
594 }
595
596 int manager_startup(Manager *m, FILE *serialization, FDSet *fds) {
597         int r, q;
598
599         assert(m);
600
601         /* First, enumerate what we can from all config files */
602         r = manager_enumerate(m);
603
604         /* Second, deserialize if there is something to deserialize */
605         if (serialization)
606                 if ((q = manager_deserialize(m, serialization, fds)) < 0)
607                         r = q;
608
609         /* Third, fire things up! */
610         if ((q = manager_coldplug(m)) < 0)
611                 r = q;
612
613         /* Now that the initial devices are available, let's see if we
614          * can write the utmp file */
615         manager_write_utmp_reboot(m);
616
617         return r;
618 }
619
620 static void transaction_delete_job(Manager *m, Job *j, bool delete_dependencies) {
621         assert(m);
622         assert(j);
623
624         /* Deletes one job from the transaction */
625
626         manager_transaction_unlink_job(m, j, delete_dependencies);
627
628         if (!j->installed)
629                 job_free(j);
630 }
631
632 static void transaction_delete_unit(Manager *m, Unit *u) {
633         Job *j;
634
635         /* Deletes all jobs associated with a certain unit from the
636          * transaction */
637
638         while ((j = hashmap_get(m->transaction_jobs, u)))
639                 transaction_delete_job(m, j, true);
640 }
641
642 static void transaction_clean_dependencies(Manager *m) {
643         Iterator i;
644         Job *j;
645
646         assert(m);
647
648         /* Drops all dependencies of all installed jobs */
649
650         HASHMAP_FOREACH(j, m->jobs, i) {
651                 while (j->subject_list)
652                         job_dependency_free(j->subject_list);
653                 while (j->object_list)
654                         job_dependency_free(j->object_list);
655         }
656
657         assert(!m->transaction_anchor);
658 }
659
660 static void transaction_abort(Manager *m) {
661         Job *j;
662
663         assert(m);
664
665         while ((j = hashmap_first(m->transaction_jobs)))
666                 if (j->installed)
667                         transaction_delete_job(m, j, true);
668                 else
669                         job_free(j);
670
671         assert(hashmap_isempty(m->transaction_jobs));
672
673         transaction_clean_dependencies(m);
674 }
675
676 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
677         JobDependency *l;
678
679         assert(m);
680
681         /* A recursive sweep through the graph that marks all units
682          * that matter to the anchor job, i.e. are directly or
683          * indirectly a dependency of the anchor job via paths that
684          * are fully marked as mattering. */
685
686         if (j)
687                 l = j->subject_list;
688         else
689                 l = m->transaction_anchor;
690
691         LIST_FOREACH(subject, l, l) {
692
693                 /* This link does not matter */
694                 if (!l->matters)
695                         continue;
696
697                 /* This unit has already been marked */
698                 if (l->object->generation == generation)
699                         continue;
700
701                 l->object->matters_to_anchor = true;
702                 l->object->generation = generation;
703
704                 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
705         }
706 }
707
708 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
709         JobDependency *l, *last;
710
711         assert(j);
712         assert(other);
713         assert(j->unit == other->unit);
714         assert(!j->installed);
715
716         /* Merges 'other' into 'j' and then deletes j. */
717
718         j->type = t;
719         j->state = JOB_WAITING;
720         j->override = j->override || other->override;
721
722         j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
723
724         /* Patch us in as new owner of the JobDependency objects */
725         last = NULL;
726         LIST_FOREACH(subject, l, other->subject_list) {
727                 assert(l->subject == other);
728                 l->subject = j;
729                 last = l;
730         }
731
732         /* Merge both lists */
733         if (last) {
734                 last->subject_next = j->subject_list;
735                 if (j->subject_list)
736                         j->subject_list->subject_prev = last;
737                 j->subject_list = other->subject_list;
738         }
739
740         /* Patch us in as new owner of the JobDependency objects */
741         last = NULL;
742         LIST_FOREACH(object, l, other->object_list) {
743                 assert(l->object == other);
744                 l->object = j;
745                 last = l;
746         }
747
748         /* Merge both lists */
749         if (last) {
750                 last->object_next = j->object_list;
751                 if (j->object_list)
752                         j->object_list->object_prev = last;
753                 j->object_list = other->object_list;
754         }
755
756         /* Kill the other job */
757         other->subject_list = NULL;
758         other->object_list = NULL;
759         transaction_delete_job(m, other, true);
760 }
761
762 static int delete_one_unmergeable_job(Manager *m, Job *j) {
763         Job *k;
764
765         assert(j);
766
767         /* Tries to delete one item in the linked list
768          * j->transaction_next->transaction_next->... that conflicts
769          * whith another one, in an attempt to make an inconsistent
770          * transaction work. */
771
772         /* We rely here on the fact that if a merged with b does not
773          * merge with c, either a or b merge with c neither */
774         LIST_FOREACH(transaction, j, j)
775                 LIST_FOREACH(transaction, k, j->transaction_next) {
776                         Job *d;
777
778                         /* Is this one mergeable? Then skip it */
779                         if (job_type_is_mergeable(j->type, k->type))
780                                 continue;
781
782                         /* Ok, we found two that conflict, let's see if we can
783                          * drop one of them */
784                         if (!j->matters_to_anchor)
785                                 d = j;
786                         else if (!k->matters_to_anchor)
787                                 d = k;
788                         else
789                                 return -ENOEXEC;
790
791                         /* Ok, we can drop one, so let's do so. */
792                         log_debug("Trying to fix job merging by deleting job %s/%s", d->unit->meta.id, job_type_to_string(d->type));
793                         transaction_delete_job(m, d, true);
794                         return 0;
795                 }
796
797         return -EINVAL;
798 }
799
800 static int transaction_merge_jobs(Manager *m) {
801         Job *j;
802         Iterator i;
803         int r;
804
805         assert(m);
806
807         /* First step, check whether any of the jobs for one specific
808          * task conflict. If so, try to drop one of them. */
809         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
810                 JobType t;
811                 Job *k;
812
813                 t = j->type;
814                 LIST_FOREACH(transaction, k, j->transaction_next) {
815                         if ((r = job_type_merge(&t, k->type)) >= 0)
816                                 continue;
817
818                         /* OK, we could not merge all jobs for this
819                          * action. Let's see if we can get rid of one
820                          * of them */
821
822                         if ((r = delete_one_unmergeable_job(m, j)) >= 0)
823                                 /* Ok, we managed to drop one, now
824                                  * let's ask our callers to call us
825                                  * again after garbage collecting */
826                                 return -EAGAIN;
827
828                         /* We couldn't merge anything. Failure */
829                         return r;
830                 }
831         }
832
833         /* Second step, merge the jobs. */
834         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
835                 JobType t = j->type;
836                 Job *k;
837
838                 /* Merge all transactions */
839                 LIST_FOREACH(transaction, k, j->transaction_next)
840                         assert_se(job_type_merge(&t, k->type) == 0);
841
842                 /* If an active job is mergeable, merge it too */
843                 if (j->unit->meta.job)
844                         job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
845
846                 while ((k = j->transaction_next)) {
847                         if (j->installed) {
848                                 transaction_merge_and_delete_job(m, k, j, t);
849                                 j = k;
850                         } else
851                                 transaction_merge_and_delete_job(m, j, k, t);
852                 }
853
854                 assert(!j->transaction_next);
855                 assert(!j->transaction_prev);
856         }
857
858         return 0;
859 }
860
861 static void transaction_drop_redundant(Manager *m) {
862         bool again;
863
864         assert(m);
865
866         /* Goes through the transaction and removes all jobs that are
867          * a noop */
868
869         do {
870                 Job *j;
871                 Iterator i;
872
873                 again = false;
874
875                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
876                         bool changes_something = false;
877                         Job *k;
878
879                         LIST_FOREACH(transaction, k, j) {
880
881                                 if (!job_is_anchor(k) &&
882                                     job_type_is_redundant(k->type, unit_active_state(k->unit)))
883                                         continue;
884
885                                 changes_something = true;
886                                 break;
887                         }
888
889                         if (changes_something)
890                                 continue;
891
892                         log_debug("Found redundant job %s/%s, dropping.", j->unit->meta.id, job_type_to_string(j->type));
893                         transaction_delete_job(m, j, false);
894                         again = true;
895                         break;
896                 }
897
898         } while (again);
899 }
900
901 static bool unit_matters_to_anchor(Unit *u, Job *j) {
902         assert(u);
903         assert(!j->transaction_prev);
904
905         /* Checks whether at least one of the jobs for this unit
906          * matters to the anchor. */
907
908         LIST_FOREACH(transaction, j, j)
909                 if (j->matters_to_anchor)
910                         return true;
911
912         return false;
913 }
914
915 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation) {
916         Iterator i;
917         Unit *u;
918         int r;
919
920         assert(m);
921         assert(j);
922         assert(!j->transaction_prev);
923
924         /* Does a recursive sweep through the ordering graph, looking
925          * for a cycle. If we find cycle we try to break it. */
926
927         /* Did we find a cycle? */
928         if (j->marker && j->generation == generation) {
929                 Job *k;
930
931                 /* So, we already have been here. We have a
932                  * cycle. Let's try to break it. We go backwards in
933                  * our path and try to find a suitable job to
934                  * remove. We use the marker to find our way back,
935                  * since smart how we are we stored our way back in
936                  * there. */
937
938                 log_debug("Found ordering cycle on %s/%s", j->unit->meta.id, job_type_to_string(j->type));
939
940                 for (k = from; k; k = (k->generation == generation ? k->marker : NULL)) {
941
942                         log_debug("Walked on cycle path to %s/%s", k->unit->meta.id, job_type_to_string(k->type));
943
944                         if (!k->installed &&
945                             !unit_matters_to_anchor(k->unit, k)) {
946                                 /* Ok, we can drop this one, so let's
947                                  * do so. */
948                                 log_debug("Breaking order cycle by deleting job %s/%s", k->unit->meta.id, job_type_to_string(k->type));
949                                 transaction_delete_unit(m, k->unit);
950                                 return -EAGAIN;
951                         }
952
953                         /* Check if this in fact was the beginning of
954                          * the cycle */
955                         if (k == j)
956                                 break;
957                 }
958
959                 log_debug("Unable to break cycle");
960
961                 return -ENOEXEC;
962         }
963
964         /* Make the marker point to where we come from, so that we can
965          * find our way backwards if we want to break a cycle */
966         j->marker = from;
967         j->generation = generation;
968
969         /* We assume that the the dependencies are bidirectional, and
970          * hence can ignore UNIT_AFTER */
971         SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
972                 Job *o;
973
974                 /* Is there a job for this unit? */
975                 if (!(o = hashmap_get(m->transaction_jobs, u)))
976
977                         /* Ok, there is no job for this in the
978                          * transaction, but maybe there is already one
979                          * running? */
980                         if (!(o = u->meta.job))
981                                 continue;
982
983                 if ((r = transaction_verify_order_one(m, o, j, generation)) < 0)
984                         return r;
985         }
986
987         /* Ok, let's backtrack, and remember that this entry is not on
988          * our path anymore. */
989         j->marker = NULL;
990
991         return 0;
992 }
993
994 static int transaction_verify_order(Manager *m, unsigned *generation) {
995         Job *j;
996         int r;
997         Iterator i;
998
999         assert(m);
1000         assert(generation);
1001
1002         /* Check if the ordering graph is cyclic. If it is, try to fix
1003          * that up by dropping one of the jobs. */
1004
1005         HASHMAP_FOREACH(j, m->transaction_jobs, i)
1006                 if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0)
1007                         return r;
1008
1009         return 0;
1010 }
1011
1012 static void transaction_collect_garbage(Manager *m) {
1013         bool again;
1014
1015         assert(m);
1016
1017         /* Drop jobs that are not required by any other job */
1018
1019         do {
1020                 Iterator i;
1021                 Job *j;
1022
1023                 again = false;
1024
1025                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1026                         if (j->object_list)
1027                                 continue;
1028
1029                         log_debug("Garbage collecting job %s/%s", j->unit->meta.id, job_type_to_string(j->type));
1030                         transaction_delete_job(m, j, true);
1031                         again = true;
1032                         break;
1033                 }
1034
1035         } while (again);
1036 }
1037
1038 static int transaction_is_destructive(Manager *m) {
1039         Iterator i;
1040         Job *j;
1041
1042         assert(m);
1043
1044         /* Checks whether applying this transaction means that
1045          * existing jobs would be replaced */
1046
1047         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1048
1049                 /* Assume merged */
1050                 assert(!j->transaction_prev);
1051                 assert(!j->transaction_next);
1052
1053                 if (j->unit->meta.job &&
1054                     j->unit->meta.job != j &&
1055                     !job_type_is_superset(j->type, j->unit->meta.job->type))
1056                         return -EEXIST;
1057         }
1058
1059         return 0;
1060 }
1061
1062 static void transaction_minimize_impact(Manager *m) {
1063         bool again;
1064         assert(m);
1065
1066         /* Drops all unnecessary jobs that reverse already active jobs
1067          * or that stop a running service. */
1068
1069         do {
1070                 Job *j;
1071                 Iterator i;
1072
1073                 again = false;
1074
1075                 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1076                         LIST_FOREACH(transaction, j, j) {
1077                                 bool stops_running_service, changes_existing_job;
1078
1079                                 /* If it matters, we shouldn't drop it */
1080                                 if (j->matters_to_anchor)
1081                                         continue;
1082
1083                                 /* Would this stop a running service?
1084                                  * Would this change an existing job?
1085                                  * If so, let's drop this entry */
1086
1087                                 stops_running_service =
1088                                         j->type == JOB_STOP && UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(j->unit));
1089
1090                                 changes_existing_job =
1091                                         j->unit->meta.job && job_type_is_conflicting(j->type, j->unit->meta.job->state);
1092
1093                                 if (!stops_running_service && !changes_existing_job)
1094                                         continue;
1095
1096                                 if (stops_running_service)
1097                                         log_debug("%s/%s would stop a running service.", j->unit->meta.id, job_type_to_string(j->type));
1098
1099                                 if (changes_existing_job)
1100                                         log_debug("%s/%s would change existing job.", j->unit->meta.id, job_type_to_string(j->type));
1101
1102                                 /* Ok, let's get rid of this */
1103                                 log_debug("Deleting %s/%s to minimize impact.", j->unit->meta.id, job_type_to_string(j->type));
1104
1105                                 transaction_delete_job(m, j, true);
1106                                 again = true;
1107                                 break;
1108                         }
1109
1110                         if (again)
1111                                 break;
1112                 }
1113
1114         } while (again);
1115 }
1116
1117 static int transaction_apply(Manager *m) {
1118         Iterator i;
1119         Job *j;
1120         int r;
1121
1122         /* Moves the transaction jobs to the set of active jobs */
1123
1124         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1125                 /* Assume merged */
1126                 assert(!j->transaction_prev);
1127                 assert(!j->transaction_next);
1128
1129                 if (j->installed)
1130                         continue;
1131
1132                 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
1133                         goto rollback;
1134         }
1135
1136         while ((j = hashmap_steal_first(m->transaction_jobs))) {
1137                 if (j->installed)
1138                         continue;
1139
1140                 if (j->unit->meta.job)
1141                         job_free(j->unit->meta.job);
1142
1143                 j->unit->meta.job = j;
1144                 j->installed = true;
1145
1146                 /* We're fully installed. Now let's free data we don't
1147                  * need anymore. */
1148
1149                 assert(!j->transaction_next);
1150                 assert(!j->transaction_prev);
1151
1152                 job_add_to_run_queue(j);
1153                 job_add_to_dbus_queue(j);
1154         }
1155
1156         /* As last step, kill all remaining job dependencies. */
1157         transaction_clean_dependencies(m);
1158
1159         return 0;
1160
1161 rollback:
1162
1163         HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1164                 if (j->installed)
1165                         continue;
1166
1167                 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
1168         }
1169
1170         return r;
1171 }
1172
1173 static int transaction_activate(Manager *m, JobMode mode) {
1174         int r;
1175         unsigned generation = 1;
1176
1177         assert(m);
1178
1179         /* This applies the changes recorded in transaction_jobs to
1180          * the actual list of jobs, if possible. */
1181
1182         /* First step: figure out which jobs matter */
1183         transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
1184
1185         /* Second step: Try not to stop any running services if
1186          * we don't have to. Don't try to reverse running
1187          * jobs if we don't have to. */
1188         transaction_minimize_impact(m);
1189
1190         /* Third step: Drop redundant jobs */
1191         transaction_drop_redundant(m);
1192
1193         for (;;) {
1194                 /* Fourth step: Let's remove unneeded jobs that might
1195                  * be lurking. */
1196                 transaction_collect_garbage(m);
1197
1198                 /* Fifth step: verify order makes sense and correct
1199                  * cycles if necessary and possible */
1200                 if ((r = transaction_verify_order(m, &generation)) >= 0)
1201                         break;
1202
1203                 if (r != -EAGAIN) {
1204                         log_debug("Requested transaction contains an unfixable cyclic ordering dependency: %s", strerror(-r));
1205                         goto rollback;
1206                 }
1207
1208                 /* Let's see if the resulting transaction ordering
1209                  * graph is still cyclic... */
1210         }
1211
1212         for (;;) {
1213                 /* Sixth step: let's drop unmergeable entries if
1214                  * necessary and possible, merge entries we can
1215                  * merge */
1216                 if ((r = transaction_merge_jobs(m)) >= 0)
1217                         break;
1218
1219                 if (r != -EAGAIN) {
1220                         log_debug("Requested transaction contains unmergable jobs: %s", strerror(-r));
1221                         goto rollback;
1222                 }
1223
1224                 /* Seventh step: an entry got dropped, let's garbage
1225                  * collect its dependencies. */
1226                 transaction_collect_garbage(m);
1227
1228                 /* Let's see if the resulting transaction still has
1229                  * unmergeable entries ... */
1230         }
1231
1232         /* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */
1233         transaction_drop_redundant(m);
1234
1235         /* Ninth step: check whether we can actually apply this */
1236         if (mode == JOB_FAIL)
1237                 if ((r = transaction_is_destructive(m)) < 0) {
1238                         log_debug("Requested transaction contradicts existing jobs: %s", strerror(-r));
1239                         goto rollback;
1240                 }
1241
1242         /* Tenth step: apply changes */
1243         if ((r = transaction_apply(m)) < 0) {
1244                 log_debug("Failed to apply transaction: %s", strerror(-r));
1245                 goto rollback;
1246         }
1247
1248         assert(hashmap_isempty(m->transaction_jobs));
1249         assert(!m->transaction_anchor);
1250
1251         return 0;
1252
1253 rollback:
1254         transaction_abort(m);
1255         return r;
1256 }
1257
1258 static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool override, bool *is_new) {
1259         Job *j, *f;
1260         int r;
1261
1262         assert(m);
1263         assert(unit);
1264
1265         /* Looks for an axisting prospective job and returns that. If
1266          * it doesn't exist it is created and added to the prospective
1267          * jobs list. */
1268
1269         f = hashmap_get(m->transaction_jobs, unit);
1270
1271         LIST_FOREACH(transaction, j, f) {
1272                 assert(j->unit == unit);
1273
1274                 if (j->type == type) {
1275                         if (is_new)
1276                                 *is_new = false;
1277                         return j;
1278                 }
1279         }
1280
1281         if (unit->meta.job && unit->meta.job->type == type)
1282                 j = unit->meta.job;
1283         else if (!(j = job_new(m, type, unit)))
1284                 return NULL;
1285
1286         j->generation = 0;
1287         j->marker = NULL;
1288         j->matters_to_anchor = false;
1289         j->override = override;
1290
1291         LIST_PREPEND(Job, transaction, f, j);
1292
1293         if ((r = hashmap_replace(m->transaction_jobs, unit, f)) < 0) {
1294                 job_free(j);
1295                 return NULL;
1296         }
1297
1298         if (is_new)
1299                 *is_new = true;
1300
1301         log_debug("Added job %s/%s to transaction.", unit->meta.id, job_type_to_string(type));
1302
1303         return j;
1304 }
1305
1306 void manager_transaction_unlink_job(Manager *m, Job *j, bool delete_dependencies) {
1307         assert(m);
1308         assert(j);
1309
1310         if (j->transaction_prev)
1311                 j->transaction_prev->transaction_next = j->transaction_next;
1312         else if (j->transaction_next)
1313                 hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
1314         else
1315                 hashmap_remove_value(m->transaction_jobs, j->unit, j);
1316
1317         if (j->transaction_next)
1318                 j->transaction_next->transaction_prev = j->transaction_prev;
1319
1320         j->transaction_prev = j->transaction_next = NULL;
1321
1322         while (j->subject_list)
1323                 job_dependency_free(j->subject_list);
1324
1325         while (j->object_list) {
1326                 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
1327
1328                 job_dependency_free(j->object_list);
1329
1330                 if (other && delete_dependencies) {
1331                         log_debug("Deleting job %s/%s as dependency of job %s/%s",
1332                                   other->unit->meta.id, job_type_to_string(other->type),
1333                                   j->unit->meta.id, job_type_to_string(j->type));
1334                         transaction_delete_job(m, other, delete_dependencies);
1335                 }
1336         }
1337 }
1338
1339 static int transaction_add_job_and_dependencies(
1340                 Manager *m,
1341                 JobType type,
1342                 Unit *unit,
1343                 Job *by,
1344                 bool matters,
1345                 bool override,
1346                 Job **_ret) {
1347         Job *ret;
1348         Iterator i;
1349         Unit *dep;
1350         int r;
1351         bool is_new;
1352
1353         assert(m);
1354         assert(type < _JOB_TYPE_MAX);
1355         assert(unit);
1356
1357         if (unit->meta.load_state != UNIT_LOADED)
1358                 return -EINVAL;
1359
1360         if (!unit_job_is_applicable(unit, type))
1361                 return -EBADR;
1362
1363         /* First add the job. */
1364         if (!(ret = transaction_add_one_job(m, type, unit, override, &is_new)))
1365                 return -ENOMEM;
1366
1367         /* Then, add a link to the job. */
1368         if (!job_dependency_new(by, ret, matters))
1369                 return -ENOMEM;
1370
1371         if (is_new) {
1372                 /* Finally, recursively add in all dependencies. */
1373                 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
1374                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
1375                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
1376                                         goto fail;
1377
1378                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
1379                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !override, override, NULL)) < 0 && r != -EBADR)
1380                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
1381
1382                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
1383                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, false, NULL)) < 0)
1384                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
1385
1386                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
1387                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
1388                                         goto fail;
1389
1390                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE_OVERRIDABLE], i)
1391                                 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !override, override, NULL)) < 0 && r != -EBADR)
1392                                         log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
1393
1394                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
1395                                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
1396                                         goto fail;
1397
1398                 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
1399
1400                         SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
1401                                 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
1402                                         goto fail;
1403                 }
1404
1405                 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
1406         }
1407
1408         if (_ret)
1409                 *_ret = ret;
1410
1411         return 0;
1412
1413 fail:
1414         return r;
1415 }
1416
1417 static int transaction_add_isolate_jobs(Manager *m) {
1418         Iterator i;
1419         Unit *u;
1420         char *k;
1421         int r;
1422
1423         assert(m);
1424
1425         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
1426
1427                 /* ignore aliases */
1428                 if (u->meta.id != k)
1429                         continue;
1430
1431                 if (UNIT_VTABLE(u)->no_isolate)
1432                         continue;
1433
1434                 /* No need to stop inactive jobs */
1435                 if (unit_active_state(u) == UNIT_INACTIVE)
1436                         continue;
1437
1438                 /* Is there already something listed for this? */
1439                 if (hashmap_get(m->transaction_jobs, u))
1440                         continue;
1441
1442                 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, u, NULL, true, false, NULL)) < 0)
1443                         log_warning("Cannot add isolate job for unit %s, ignoring: %s", u->meta.id, strerror(-r));
1444         }
1445
1446         return 0;
1447 }
1448
1449 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool override, Job **_ret) {
1450         int r;
1451         Job *ret;
1452
1453         assert(m);
1454         assert(type < _JOB_TYPE_MAX);
1455         assert(unit);
1456         assert(mode < _JOB_MODE_MAX);
1457
1458         if (mode == JOB_ISOLATE && type != JOB_START)
1459                 return -EINVAL;
1460
1461         log_debug("Trying to enqueue job %s/%s", unit->meta.id, job_type_to_string(type));
1462
1463         if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, override, &ret)) < 0) {
1464                 transaction_abort(m);
1465                 return r;
1466         }
1467
1468         if (mode == JOB_ISOLATE)
1469                 if ((r = transaction_add_isolate_jobs(m)) < 0) {
1470                         transaction_abort(m);
1471                         return r;
1472                 }
1473
1474         if ((r = transaction_activate(m, mode)) < 0)
1475                 return r;
1476
1477         log_debug("Enqueued job %s/%s as %u", unit->meta.id, job_type_to_string(type), (unsigned) ret->id);
1478
1479         if (_ret)
1480                 *_ret = ret;
1481
1482         return 0;
1483 }
1484
1485 int manager_add_job_by_name(Manager *m, JobType type, const char *name, JobMode mode, bool override, Job **_ret) {
1486         Unit *unit;
1487         int r;
1488
1489         assert(m);
1490         assert(type < _JOB_TYPE_MAX);
1491         assert(name);
1492         assert(mode < _JOB_MODE_MAX);
1493
1494         if ((r = manager_load_unit(m, name, NULL, &unit)) < 0)
1495                 return r;
1496
1497         return manager_add_job(m, type, unit, mode, override, _ret);
1498 }
1499
1500 Job *manager_get_job(Manager *m, uint32_t id) {
1501         assert(m);
1502
1503         return hashmap_get(m->jobs, UINT32_TO_PTR(id));
1504 }
1505
1506 Unit *manager_get_unit(Manager *m, const char *name) {
1507         assert(m);
1508         assert(name);
1509
1510         return hashmap_get(m->units, name);
1511 }
1512
1513 unsigned manager_dispatch_load_queue(Manager *m) {
1514         Meta *meta;
1515         unsigned n = 0;
1516
1517         assert(m);
1518
1519         /* Make sure we are not run recursively */
1520         if (m->dispatching_load_queue)
1521                 return 0;
1522
1523         m->dispatching_load_queue = true;
1524
1525         /* Dispatches the load queue. Takes a unit from the queue and
1526          * tries to load its data until the queue is empty */
1527
1528         while ((meta = m->load_queue)) {
1529                 assert(meta->in_load_queue);
1530
1531                 unit_load(UNIT(meta));
1532                 n++;
1533         }
1534
1535         m->dispatching_load_queue = false;
1536         return n;
1537 }
1538
1539 int manager_load_unit(Manager *m, const char *name, const char *path, Unit **_ret) {
1540         Unit *ret;
1541         int r;
1542
1543         assert(m);
1544         assert(name || path);
1545
1546         /* This will load the service information files, but not actually
1547          * start any services or anything. */
1548
1549         if (path && !is_path(path))
1550                 return -EINVAL;
1551
1552         if (!name)
1553                 name = file_name_from_path(path);
1554
1555         if (!unit_name_is_valid(name))
1556                 return -EINVAL;
1557
1558         if ((ret = manager_get_unit(m, name))) {
1559                 *_ret = ret;
1560                 return 0;
1561         }
1562
1563         if (!(ret = unit_new(m)))
1564                 return -ENOMEM;
1565
1566         if (path)
1567                 if (!(ret->meta.fragment_path = strdup(path))) {
1568                         unit_free(ret);
1569                         return -ENOMEM;
1570                 }
1571
1572         if ((r = unit_add_name(ret, name)) < 0) {
1573                 unit_free(ret);
1574                 return r;
1575         }
1576
1577         unit_add_to_load_queue(ret);
1578         unit_add_to_dbus_queue(ret);
1579
1580         manager_dispatch_load_queue(m);
1581
1582         if (_ret)
1583                 *_ret = unit_follow_merge(ret);
1584
1585         return 0;
1586 }
1587
1588 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
1589         Iterator i;
1590         Job *j;
1591
1592         assert(s);
1593         assert(f);
1594
1595         HASHMAP_FOREACH(j, s->jobs, i)
1596                 job_dump(j, f, prefix);
1597 }
1598
1599 void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
1600         Iterator i;
1601         Unit *u;
1602         const char *t;
1603
1604         assert(s);
1605         assert(f);
1606
1607         HASHMAP_FOREACH_KEY(u, t, s->units, i)
1608                 if (u->meta.id == t)
1609                         unit_dump(u, f, prefix);
1610 }
1611
1612 void manager_clear_jobs(Manager *m) {
1613         Job *j;
1614
1615         assert(m);
1616
1617         transaction_abort(m);
1618
1619         while ((j = hashmap_first(m->jobs)))
1620                 job_free(j);
1621 }
1622
1623 unsigned manager_dispatch_run_queue(Manager *m) {
1624         Job *j;
1625         unsigned n = 0;
1626
1627         if (m->dispatching_run_queue)
1628                 return 0;
1629
1630         m->dispatching_run_queue = true;
1631
1632         while ((j = m->run_queue)) {
1633                 assert(j->installed);
1634                 assert(j->in_run_queue);
1635
1636                 job_run_and_invalidate(j);
1637                 n++;
1638         }
1639
1640         m->dispatching_run_queue = false;
1641         return n;
1642 }
1643
1644 unsigned manager_dispatch_dbus_queue(Manager *m) {
1645         Job *j;
1646         Meta *meta;
1647         unsigned n = 0;
1648
1649         assert(m);
1650
1651         if (m->dispatching_dbus_queue)
1652                 return 0;
1653
1654         m->dispatching_dbus_queue = true;
1655
1656         while ((meta = m->dbus_unit_queue)) {
1657                 assert(meta->in_dbus_queue);
1658
1659                 bus_unit_send_change_signal(UNIT(meta));
1660                 n++;
1661         }
1662
1663         while ((j = m->dbus_job_queue)) {
1664                 assert(j->in_dbus_queue);
1665
1666                 bus_job_send_change_signal(j);
1667                 n++;
1668         }
1669
1670         m->dispatching_dbus_queue = false;
1671         return n;
1672 }
1673
1674 static int manager_dispatch_sigchld(Manager *m) {
1675         assert(m);
1676
1677         for (;;) {
1678                 siginfo_t si;
1679                 Unit *u;
1680
1681                 zero(si);
1682
1683                 /* First we call waitd() for a PID and do not reap the
1684                  * zombie. That way we can still access /proc/$PID for
1685                  * it while it is a zombie. */
1686                 if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG|WNOWAIT) < 0) {
1687
1688                         if (errno == ECHILD)
1689                                 break;
1690
1691                         if (errno == EINTR)
1692                                 continue;
1693
1694                         return -errno;
1695                 }
1696
1697                 if (si.si_pid <= 0)
1698                         break;
1699
1700                 if (si.si_code == CLD_EXITED || si.si_code == CLD_KILLED || si.si_code == CLD_DUMPED) {
1701                         char *name = NULL;
1702
1703                         get_process_name(si.si_pid, &name);
1704                         log_debug("Got SIGCHLD for process %llu (%s)", (unsigned long long) si.si_pid, strna(name));
1705                         free(name);
1706                 }
1707
1708                 /* And now, we actually reap the zombie. */
1709                 if (waitid(P_PID, si.si_pid, &si, WEXITED) < 0) {
1710                         if (errno == EINTR)
1711                                 continue;
1712
1713                         return -errno;
1714                 }
1715
1716                 if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
1717                         continue;
1718
1719                 log_debug("Child %llu died (code=%s, status=%i/%s)",
1720                           (long long unsigned) si.si_pid,
1721                           sigchld_code_to_string(si.si_code),
1722                           si.si_status,
1723                           strna(si.si_code == CLD_EXITED ? exit_status_to_string(si.si_status) : strsignal(si.si_status)));
1724
1725                 if (!(u = hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid))))
1726                         continue;
1727
1728                 log_debug("Child %llu belongs to %s", (long long unsigned) si.si_pid, u->meta.id);
1729
1730                 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
1731         }
1732
1733         return 0;
1734 }
1735
1736 static void manager_start_target(Manager *m, const char *name) {
1737         int r;
1738
1739         if ((r = manager_add_job_by_name(m, JOB_START, name, JOB_REPLACE, true, NULL)) < 0)
1740                 log_error("Failed to enqueue %s job: %s", name, strerror(-r));
1741 }
1742
1743 static int manager_process_signal_fd(Manager *m) {
1744         ssize_t n;
1745         struct signalfd_siginfo sfsi;
1746         bool sigchld = false;
1747
1748         assert(m);
1749
1750         for (;;) {
1751                 if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
1752
1753                         if (n >= 0)
1754                                 return -EIO;
1755
1756                         if (errno == EAGAIN)
1757                                 break;
1758
1759                         return -errno;
1760                 }
1761
1762                 switch (sfsi.ssi_signo) {
1763
1764                 case SIGCHLD:
1765                         sigchld = true;
1766                         break;
1767
1768                 case SIGINT:
1769                 case SIGTERM:
1770
1771                         if (m->running_as == MANAGER_INIT) {
1772                                 manager_start_target(m, SPECIAL_CTRL_ALT_DEL_TARGET);
1773                                 break;
1774                         }
1775
1776                         m->exit_code = MANAGER_EXIT;
1777                         return 0;
1778
1779                 case SIGWINCH:
1780
1781                         if (m->running_as == MANAGER_INIT)
1782                                 manager_start_target(m, SPECIAL_KBREQUEST_TARGET);
1783
1784                         /* This is a nop on non-init */
1785                         break;
1786
1787                 case SIGPWR:
1788                         if (m->running_as == MANAGER_INIT)
1789                                 manager_start_target(m, SPECIAL_SIGPWR_TARGET);
1790
1791                         /* This is a nop on non-init */
1792                         break;
1793
1794                 case SIGUSR1:
1795                         manager_dump_units(m, stdout, "\t");
1796                         manager_dump_jobs(m, stdout, "\t");
1797                         break;
1798
1799                 case SIGUSR2:  {
1800                         Unit *u;
1801
1802                         u = manager_get_unit(m, SPECIAL_DBUS_SERVICE);
1803
1804                         if (!u || UNIT_IS_ACTIVE_OR_RELOADING(unit_active_state(u))) {
1805                                 log_info("Trying to reconnect to bus...");
1806                                 bus_init_system(m);
1807                                 bus_init_api(m);
1808                         }
1809
1810                         if (!u || !UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u))) {
1811                                 log_info("Loading D-Bus service...");
1812                                 manager_start_target(m, SPECIAL_DBUS_SERVICE);
1813                         }
1814
1815                         break;
1816                 }
1817
1818                 case SIGHUP:
1819                         m->exit_code = MANAGER_RELOAD;
1820                         break;
1821
1822                 default:
1823                         log_info("Got unhandled signal <%s>.", strsignal(sfsi.ssi_signo));
1824                 }
1825         }
1826
1827         if (sigchld)
1828                 return manager_dispatch_sigchld(m);
1829
1830         return 0;
1831 }
1832
1833 static int process_event(Manager *m, struct epoll_event *ev) {
1834         int r;
1835         Watch *w;
1836
1837         assert(m);
1838         assert(ev);
1839
1840         assert(w = ev->data.ptr);
1841
1842         switch (w->type) {
1843
1844         case WATCH_SIGNAL:
1845
1846                 /* An incoming signal? */
1847                 if (ev->events != EPOLLIN)
1848                         return -EINVAL;
1849
1850                 if ((r = manager_process_signal_fd(m)) < 0)
1851                         return r;
1852
1853                 break;
1854
1855         case WATCH_FD:
1856
1857                 /* Some fd event, to be dispatched to the units */
1858                 UNIT_VTABLE(w->data.unit)->fd_event(w->data.unit, w->fd, ev->events, w);
1859                 break;
1860
1861         case WATCH_TIMER: {
1862                 uint64_t v;
1863                 ssize_t k;
1864
1865                 /* Some timer event, to be dispatched to the units */
1866                 if ((k = read(w->fd, &v, sizeof(v))) != sizeof(v)) {
1867
1868                         if (k < 0 && (errno == EINTR || errno == EAGAIN))
1869                                 break;
1870
1871                         return k < 0 ? -errno : -EIO;
1872                 }
1873
1874                 UNIT_VTABLE(w->data.unit)->timer_event(w->data.unit, v, w);
1875                 break;
1876         }
1877
1878         case WATCH_MOUNT:
1879                 /* Some mount table change, intended for the mount subsystem */
1880                 mount_fd_event(m, ev->events);
1881                 break;
1882
1883         case WATCH_UDEV:
1884                 /* Some notification from udev, intended for the device subsystem */
1885                 device_fd_event(m, ev->events);
1886                 break;
1887
1888         case WATCH_DBUS_WATCH:
1889                 bus_watch_event(m, w, ev->events);
1890                 break;
1891
1892         case WATCH_DBUS_TIMEOUT:
1893                 bus_timeout_event(m, w, ev->events);
1894                 break;
1895
1896         default:
1897                 assert_not_reached("Unknown epoll event type.");
1898         }
1899
1900         return 0;
1901 }
1902
1903 int manager_loop(Manager *m) {
1904         int r;
1905
1906         RATELIMIT_DEFINE(rl, 1*USEC_PER_SEC, 1000);
1907
1908         assert(m);
1909         m->exit_code = MANAGER_RUNNING;
1910
1911         while (m->exit_code == MANAGER_RUNNING) {
1912                 struct epoll_event event;
1913                 int n;
1914
1915                 if (!ratelimit_test(&rl)) {
1916                         /* Yay, something is going seriously wrong, pause a little */
1917                         log_warning("Looping too fast. Throttling execution a little.");
1918                         sleep(1);
1919                 }
1920
1921                 if (manager_dispatch_cleanup_queue(m) > 0)
1922                         continue;
1923
1924                 if (manager_dispatch_gc_queue(m) > 0)
1925                         continue;
1926
1927                 if (manager_dispatch_load_queue(m) > 0)
1928                         continue;
1929
1930                 if (manager_dispatch_run_queue(m) > 0)
1931                         continue;
1932
1933                 if (bus_dispatch(m) > 0)
1934                         continue;
1935
1936                 if (manager_dispatch_dbus_queue(m) > 0)
1937                         continue;
1938
1939                 if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) {
1940
1941                         if (errno == -EINTR)
1942                                 continue;
1943
1944                         return -errno;
1945                 }
1946
1947                 assert(n == 1);
1948
1949                 if ((r = process_event(m, &event)) < 0)
1950                         return r;
1951         }
1952
1953         return m->exit_code;
1954 }
1955
1956 int manager_get_unit_from_dbus_path(Manager *m, const char *s, Unit **_u) {
1957         char *n;
1958         Unit *u;
1959
1960         assert(m);
1961         assert(s);
1962         assert(_u);
1963
1964         if (!startswith(s, "/org/freedesktop/systemd1/unit/"))
1965                 return -EINVAL;
1966
1967         if (!(n = bus_path_unescape(s+31)))
1968                 return -ENOMEM;
1969
1970         u = manager_get_unit(m, n);
1971         free(n);
1972
1973         if (!u)
1974                 return -ENOENT;
1975
1976         *_u = u;
1977
1978         return 0;
1979 }
1980
1981 int manager_get_job_from_dbus_path(Manager *m, const char *s, Job **_j) {
1982         Job *j;
1983         unsigned id;
1984         int r;
1985
1986         assert(m);
1987         assert(s);
1988         assert(_j);
1989
1990         if (!startswith(s, "/org/freedesktop/systemd1/job/"))
1991                 return -EINVAL;
1992
1993         if ((r = safe_atou(s + 30, &id)) < 0)
1994                 return r;
1995
1996         if (!(j = manager_get_job(m, id)))
1997                 return -ENOENT;
1998
1999         *_j = j;
2000
2001         return 0;
2002 }
2003
2004 static bool manager_utmp_good(Manager *m) {
2005         int r;
2006
2007         assert(m);
2008
2009         if ((r = mount_path_is_mounted(m, _PATH_UTMPX)) <= 0) {
2010
2011                 if (r < 0)
2012                         log_warning("Failed to determine whether " _PATH_UTMPX " is mounted: %s", strerror(-r));
2013
2014                 return false;
2015         }
2016
2017         return true;
2018 }
2019
2020 void manager_write_utmp_reboot(Manager *m) {
2021         int r;
2022
2023         assert(m);
2024
2025         if (m->utmp_reboot_written)
2026                 return;
2027
2028         if (m->running_as != MANAGER_INIT)
2029                 return;
2030
2031         if (!manager_utmp_good(m))
2032                 return;
2033
2034         if ((r = utmp_put_reboot(m->boot_timestamp)) < 0) {
2035
2036                 if (r != -ENOENT && r != -EROFS)
2037                         log_warning("Failed to write utmp/wtmp: %s", strerror(-r));
2038
2039                 return;
2040         }
2041
2042         m->utmp_reboot_written = true;
2043 }
2044
2045 void manager_write_utmp_runlevel(Manager *m, Unit *u) {
2046         int runlevel, r;
2047
2048         assert(m);
2049         assert(u);
2050
2051         if (u->meta.type != UNIT_TARGET)
2052                 return;
2053
2054         if (m->running_as != MANAGER_INIT)
2055                 return;
2056
2057         if (!manager_utmp_good(m))
2058                 return;
2059
2060         if ((runlevel = target_get_runlevel(TARGET(u))) <= 0)
2061                 return;
2062
2063         if ((r = utmp_put_runlevel(0, runlevel, 0)) < 0) {
2064
2065                 if (r != -ENOENT && r != -EROFS)
2066                         log_warning("Failed to write utmp/wtmp: %s", strerror(-r));
2067         }
2068 }
2069
2070 void manager_dispatch_bus_name_owner_changed(
2071                 Manager *m,
2072                 const char *name,
2073                 const char* old_owner,
2074                 const char *new_owner) {
2075
2076         Unit *u;
2077
2078         assert(m);
2079         assert(name);
2080
2081         if (!(u = hashmap_get(m->watch_bus, name)))
2082                 return;
2083
2084         UNIT_VTABLE(u)->bus_name_owner_change(u, name, old_owner, new_owner);
2085 }
2086
2087 void manager_dispatch_bus_query_pid_done(
2088                 Manager *m,
2089                 const char *name,
2090                 pid_t pid) {
2091
2092         Unit *u;
2093
2094         assert(m);
2095         assert(name);
2096         assert(pid >= 1);
2097
2098         if (!(u = hashmap_get(m->watch_bus, name)))
2099                 return;
2100
2101         UNIT_VTABLE(u)->bus_query_pid_done(u, name, pid);
2102 }
2103
2104 int manager_open_serialization(FILE **_f) {
2105         char *path;
2106         mode_t saved_umask;
2107         int fd;
2108         FILE *f;
2109
2110         assert(_f);
2111
2112         if (asprintf(&path, "/dev/shm/systemd-%u.dump-XXXXXX", (unsigned) getpid()) < 0)
2113                 return -ENOMEM;
2114
2115         saved_umask = umask(0077);
2116         fd = mkostemp(path, O_RDWR|O_CLOEXEC);
2117         umask(saved_umask);
2118
2119         if (fd < 0) {
2120                 free(path);
2121                 return -errno;
2122         }
2123
2124         unlink(path);
2125
2126         log_debug("Serializing state to %s", path);
2127         free(path);
2128
2129         if (!(f = fdopen(fd, "w+")) < 0)
2130                 return -errno;
2131
2132         *_f = f;
2133
2134         return 0;
2135 }
2136
2137 int manager_serialize(Manager *m, FILE *f, FDSet *fds) {
2138         Iterator i;
2139         Unit *u;
2140         const char *t;
2141         int r;
2142
2143         assert(m);
2144         assert(f);
2145         assert(fds);
2146
2147         HASHMAP_FOREACH_KEY(u, t, m->units, i) {
2148                 if (u->meta.id != t)
2149                         continue;
2150
2151                 if (!unit_can_serialize(u))
2152                         continue;
2153
2154                 /* Start marker */
2155                 fputs(u->meta.id, f);
2156                 fputc('\n', f);
2157
2158                 if ((r = unit_serialize(u, f, fds)) < 0)
2159                         return r;
2160         }
2161
2162         if (ferror(f))
2163                 return -EIO;
2164
2165         return 0;
2166 }
2167
2168 int manager_deserialize(Manager *m, FILE *f, FDSet *fds) {
2169         int r = 0;
2170
2171         assert(m);
2172         assert(f);
2173
2174         log_debug("Deserializing state...");
2175
2176         for (;;) {
2177                 Unit *u;
2178                 char name[UNIT_NAME_MAX+2];
2179
2180                 /* Start marker */
2181                 if (!fgets(name, sizeof(name), f)) {
2182                         if (feof(f))
2183                                 break;
2184
2185                         return -errno;
2186                 }
2187
2188                 char_array_0(name);
2189
2190                 if ((r = manager_load_unit(m, strstrip(name), NULL, &u)) < 0)
2191                         return r;
2192
2193                 if ((r = unit_deserialize(u, f, fds)) < 0)
2194                         return r;
2195         }
2196
2197         if (ferror(f))
2198                 return -EIO;
2199
2200         return 0;
2201 }
2202
2203 int manager_reload(Manager *m) {
2204         int r, q;
2205         FILE *f;
2206         FDSet *fds;
2207
2208         assert(m);
2209
2210         if ((r = manager_open_serialization(&f)) < 0)
2211                 return r;
2212
2213         if (!(fds = fdset_new())) {
2214                 r = -ENOMEM;
2215                 goto finish;
2216         }
2217
2218         if ((r = manager_serialize(m, f, fds)) < 0)
2219                 goto finish;
2220
2221         if (fseeko(f, 0, SEEK_SET) < 0) {
2222                 r = -errno;
2223                 goto finish;
2224         }
2225
2226         /* From here on there is no way back. */
2227         manager_clear_jobs_and_units(m);
2228
2229         /* First, enumerate what we can from all config files */
2230         if ((q = manager_enumerate(m)) < 0)
2231                 r = q;
2232
2233         /* Second, deserialize our stored data */
2234         if ((q = manager_deserialize(m, f, fds)) < 0)
2235                 r = q;
2236
2237         fclose(f);
2238         f = NULL;
2239
2240         /* Third, fire things up! */
2241         if ((q = manager_coldplug(m)) < 0)
2242                 r = q;
2243
2244 finish:
2245         if (f)
2246                 fclose(f);
2247
2248         if (fds)
2249                 fdset_free(fds);
2250
2251         return r;
2252 }
2253
2254 static const char* const manager_running_as_table[_MANAGER_RUNNING_AS_MAX] = {
2255         [MANAGER_INIT] = "init",
2256         [MANAGER_SYSTEM] = "system",
2257         [MANAGER_SESSION] = "session"
2258 };
2259
2260 DEFINE_STRING_TABLE_LOOKUP(manager_running_as, ManagerRunningAs);