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