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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 #include "missing.h"
55
56 /* As soon as 16 units are in our GC queue, make sure to run a gc sweep */
57 #define GC_QUEUE_ENTRIES_MAX 16
58
59 /* As soon as 5s passed since a unit was added to our GC queue, make sure to run a gc sweep */
60 #define GC_QUEUE_USEC_MAX (5*USEC_PER_SEC)
61
62 static int enable_special_signals(Manager *m) {
63 char fd;
64
65 assert(m);
66
67 /* Enable that we get SIGINT on control-alt-del */
68 if (reboot(RB_DISABLE_CAD) < 0)
69 log_warning("Failed to enable ctrl-alt-del handling: %m");
70
71 if ((fd = open_terminal("/dev/tty0", O_RDWR)) < 0)
72 log_warning("Failed to open /dev/tty0: %m");
73 else {
74 /* Enable that we get SIGWINCH on kbrequest */
75 if (ioctl(fd, KDSIGACCEPT, SIGWINCH) < 0)
76 log_warning("Failed to enable kbrequest handling: %s", strerror(errno));
77
78 close_nointr_nofail(fd);
79 }
80
81 return 0;
82 }
83
84 static int manager_setup_signals(Manager *m) {
85 sigset_t mask;
86 struct epoll_event ev;
87 struct sigaction sa;
88
89 assert(m);
90
91 /* We are not interested in SIGSTOP and friends. */
92 zero(sa);
93 sa.sa_handler = SIG_DFL;
94 sa.sa_flags = SA_NOCLDSTOP|SA_RESTART;
95 assert_se(sigaction(SIGCHLD, &sa, NULL) == 0);
96
97 assert_se(sigemptyset(&mask) == 0);
98 assert_se(sigaddset(&mask, SIGCHLD) == 0);
99 assert_se(sigaddset(&mask, SIGTERM) == 0);
100 assert_se(sigaddset(&mask, SIGHUP) == 0);
101 assert_se(sigaddset(&mask, SIGUSR1) == 0);
102 assert_se(sigaddset(&mask, SIGUSR2) == 0);
103 assert_se(sigaddset(&mask, SIGINT) == 0); /* Kernel sends us this on control-alt-del */
104 assert_se(sigaddset(&mask, SIGWINCH) == 0); /* Kernel sends us this on kbrequest (alt-arrowup) */
105 assert_se(sigaddset(&mask, SIGPWR) == 0); /* Some kernel drivers and upsd send us this on power failure */
106 assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
107
108 m->signal_watch.type = WATCH_SIGNAL;
109 if ((m->signal_watch.fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
110 return -errno;
111
112 zero(ev);
113 ev.events = EPOLLIN;
114 ev.data.ptr = &m->signal_watch;
115
116 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_watch.fd, &ev) < 0)
117 return -errno;
118
119 if (m->running_as == MANAGER_INIT)
120 return enable_special_signals(m);
121
122 return 0;
123 }
124
125 static char** session_dirs(void) {
126 const char *home, *e;
127 char *config_home = NULL, *data_home = NULL;
128 char **config_dirs = NULL, **data_dirs = NULL;
129 char **r = NULL, **t;
130
131 /* Implement the mechanisms defined in
132 *
133 * http://standards.freedesktop.org/basedir-spec/basedir-spec-0.6.html
134 *
135 * We look in both the config and the data dirs because we
136 * want to encourage that distributors ship their unit files
137 * as data, and allow overriding as configuration.
138 */
139
140 home = getenv("HOME");
141
142 if ((e = getenv("XDG_CONFIG_HOME"))) {
143 if (asprintf(&config_home, "%s/systemd/session", e) < 0)
144 goto fail;
145
146 } else if (home) {
147 if (asprintf(&config_home, "%s/.config/systemd/session", home) < 0)
148 goto fail;
149 }
150
151 if ((e = getenv("XDG_CONFIG_DIRS")))
152 config_dirs = strv_split(e, ":");
153 else
154 config_dirs = strv_new("/etc/xdg", NULL);
155
156 if (!config_dirs)
157 goto fail;
158
159 if ((e = getenv("XDG_DATA_HOME"))) {
160 if (asprintf(&data_home, "%s/systemd/session", e) < 0)
161 goto fail;
162
163 } else if (home) {
164 if (asprintf(&data_home, "%s/.local/share/systemd/session", home) < 0)
165 goto fail;
166 }
167
168 if ((e = getenv("XDG_DATA_DIRS")))
169 data_dirs = strv_split(e, ":");
170 else
171 data_dirs = strv_new("/usr/local/share", "/usr/share", NULL);
172
173 if (!data_dirs)
174 goto fail;
175
176 /* Now merge everything we found. */
177 if (config_home) {
178 if (!(t = strv_append(r, config_home)))
179 goto fail;
180 strv_free(r);
181 r = t;
182 }
183
184 if (!(t = strv_merge_concat(r, config_dirs, "/systemd/session")))
185 goto finish;
186 strv_free(r);
187 r = t;
188
189 if (!(t = strv_append(r, SESSION_CONFIG_UNIT_PATH)))
190 goto fail;
191 strv_free(r);
192 r = t;
193
194 if (data_home) {
195 if (!(t = strv_append(r, data_home)))
196 goto fail;
197 strv_free(r);
198 r = t;
199 }
200
201 if (!(t = strv_merge_concat(r, data_dirs, "/systemd/session")))
202 goto fail;
203 strv_free(r);
204 r = t;
205
206 if (!(t = strv_append(r, SESSION_DATA_UNIT_PATH)))
207 goto fail;
208 strv_free(r);
209 r = t;
210
211 if (!strv_path_make_absolute_cwd(r))
212 goto fail;
213
214 finish:
215 free(config_home);
216 strv_free(config_dirs);
217 free(data_home);
218 strv_free(data_dirs);
219
220 return r;
221
222 fail:
223 strv_free(r);
224 r = NULL;
225 goto finish;
226 }
227
228 static int manager_find_paths(Manager *m) {
229 const char *e;
230 char *t;
231
232 assert(m);
233
234 /* First priority is whatever has been passed to us via env
235 * vars */
236 if ((e = getenv("SYSTEMD_UNIT_PATH")))
237 if (!(m->unit_path = split_path_and_make_absolute(e)))
238 return -ENOMEM;
239
240 if (strv_isempty(m->unit_path)) {
241
242 /* Nothing is set, so let's figure something out. */
243 strv_free(m->unit_path);
244
245 if (m->running_as == MANAGER_SESSION) {
246 if (!(m->unit_path = session_dirs()))
247 return -ENOMEM;
248 } else
249 if (!(m->unit_path = strv_new(
250 SYSTEM_CONFIG_UNIT_PATH, /* /etc/systemd/system/ */
251 SYSTEM_DATA_UNIT_PATH, /* /lib/systemd/system/ */
252 NULL)))
253 return -ENOMEM;
254 }
255
256 if (m->running_as == MANAGER_INIT) {
257 /* /etc/init.d/ compativility does not matter to users */
258
259 if ((e = getenv("SYSTEMD_SYSVINIT_PATH")))
260 if (!(m->sysvinit_path = split_path_and_make_absolute(e)))
261 return -ENOMEM;
262
263 if (strv_isempty(m->sysvinit_path)) {
264 strv_free(m->sysvinit_path);
265
266 if (!(m->sysvinit_path = strv_new(
267 SYSTEM_SYSVINIT_PATH, /* /etc/init.d/ */
268 NULL)))
269 return -ENOMEM;
270 }
271
272 if ((e = getenv("SYSTEMD_SYSVRCND_PATH")))
273 if (!(m->sysvrcnd_path = split_path_and_make_absolute(e)))
274 return -ENOMEM;
275
276 if (strv_isempty(m->sysvrcnd_path)) {
277 strv_free(m->sysvrcnd_path);
278
279 if (!(m->sysvrcnd_path = strv_new(
280 SYSTEM_SYSVRCND_PATH, /* /etc/rcN.d/ */
281 NULL)))
282 return -ENOMEM;
283 }
284 }
285
286 strv_uniq(m->unit_path);
287 strv_uniq(m->sysvinit_path);
288 strv_uniq(m->sysvrcnd_path);
289
290 assert(!strv_isempty(m->unit_path));
291 if (!(t = strv_join(m->unit_path, "\n\t")))
292 return -ENOMEM;
293 log_debug("Looking for unit files in:\n\t%s", t);
294 free(t);
295
296 if (!strv_isempty(m->sysvinit_path)) {
297
298 if (!(t = strv_join(m->sysvinit_path, "\n\t")))
299 return -ENOMEM;
300
301 log_debug("Looking for SysV init scripts in:\n\t%s", t);
302 free(t);
303 } else
304 log_debug("Ignoring SysV init scripts.");
305
306 if (!strv_isempty(m->sysvrcnd_path)) {
307
308 if (!(t = strv_join(m->sysvrcnd_path, "\n\t")))
309 return -ENOMEM;
310
311 log_debug("Looking for SysV rcN.d links in:\n\t%s", t);
312 free(t);
313 } else
314 log_debug("Ignoring SysV rcN.d links.");
315
316 return 0;
317 }
318
319 int manager_new(ManagerRunningAs running_as, bool confirm_spawn, Manager **_m) {
320 Manager *m;
321 int r = -ENOMEM;
322
323 assert(_m);
324 assert(running_as >= 0);
325 assert(running_as < _MANAGER_RUNNING_AS_MAX);
326
327 if (!(m = new0(Manager, 1)))
328 return -ENOMEM;
329
330 m->boot_timestamp = now(CLOCK_REALTIME);
331
332 m->running_as = running_as;
333 m->confirm_spawn = confirm_spawn;
334 m->name_data_slot = -1;
335 m->exit_code = _MANAGER_EXIT_CODE_INVALID;
336
337 m->signal_watch.fd = m->mount_watch.fd = m->udev_watch.fd = m->epoll_fd = m->dev_autofs_fd = -1;
338 m->current_job_id = 1; /* start as id #1, so that we can leave #0 around as "null-like" value */
339
340 if (!(m->environment = strv_copy(environ)))
341 goto fail;
342
343 if (!(m->units = hashmap_new(string_hash_func, string_compare_func)))
344 goto fail;
345
346 if (!(m->jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
347 goto fail;
348
349 if (!(m->transaction_jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
350 goto fail;
351
352 if (!(m->watch_pids = hashmap_new(trivial_hash_func, trivial_compare_func)))
353 goto fail;
354
355 if (!(m->cgroup_bondings = hashmap_new(string_hash_func, string_compare_func)))
356 goto fail;
357
358 if (!(m->watch_bus = hashmap_new(string_hash_func, string_compare_func)))
359 goto fail;
360
361 if ((m->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0)
362 goto fail;
363
364 if ((r = manager_find_paths(m)) < 0)
365 goto fail;
366
367 if ((r = manager_setup_signals(m)) < 0)
368 goto fail;
369
370 if ((r = manager_setup_cgroup(m)) < 0)
371 goto fail;
372
373 /* Try to connect to the busses, if possible. */
374 if ((r = bus_init_system(m)) < 0 ||
375 (r = bus_init_api(m)) < 0)
376 goto fail;
377
378 *_m = m;
379 return 0;
380
381 fail:
382 manager_free(m);
383 return r;
384 }
385
386 static unsigned manager_dispatch_cleanup_queue(Manager *m) {
387 Meta *meta;
388 unsigned n = 0;
389
390 assert(m);
391
392 while ((meta = m->cleanup_queue)) {
393 assert(meta->in_cleanup_queue);
394
395 unit_free(UNIT(meta));
396 n++;
397 }
398
399 return n;
400 }
401
402 enum {
403 GC_OFFSET_IN_PATH, /* This one is on the path we were travelling */
404 GC_OFFSET_UNSURE, /* No clue */
405 GC_OFFSET_GOOD, /* We still need this unit */
406 GC_OFFSET_BAD, /* We don't need this unit anymore */
407 _GC_OFFSET_MAX
408 };
409
410 static void unit_gc_sweep(Unit *u, unsigned gc_marker) {
411 Iterator i;
412 Unit *other;
413 bool is_bad;
414
415 assert(u);
416
417 if (u->meta.gc_marker == gc_marker + GC_OFFSET_GOOD ||
418 u->meta.gc_marker == gc_marker + GC_OFFSET_BAD ||
419 u->meta.gc_marker == gc_marker + GC_OFFSET_IN_PATH)
420 return;
421
422 if (u->meta.in_cleanup_queue)
423 goto bad;
424
425 if (unit_check_gc(u))
426 goto good;
427
428 u->meta.gc_marker = gc_marker + GC_OFFSET_IN_PATH;
429
430 is_bad = true;
431
432 SET_FOREACH(other, u->meta.dependencies[UNIT_REFERENCED_BY], i) {
433 unit_gc_sweep(other, gc_marker);
434
435 if (other->meta.gc_marker == gc_marker + GC_OFFSET_GOOD)
436 goto good;
437
438 if (other->meta.gc_marker != gc_marker + GC_OFFSET_BAD)
439 is_bad = false;
440 }
441
442 if (is_bad)
443 goto bad;
444
445 /* We were unable to find anything out about this entry, so
446 * let's investigate it later */
447 u->meta.gc_marker = gc_marker + GC_OFFSET_UNSURE;
448 unit_add_to_gc_queue(u);
449 return;
450
451 bad:
452 /* We definitely know that this one is not useful anymore, so
453 * let's mark it for deletion */
454 u->meta.gc_marker = gc_marker + GC_OFFSET_BAD;
455 unit_add_to_cleanup_queue(u);
456 return;
457
458 good:
459 u->meta.gc_marker = gc_marker + GC_OFFSET_GOOD;
460 }
461
462 static unsigned manager_dispatch_gc_queue(Manager *m) {
463 Meta *meta;
464 unsigned n = 0;
465 unsigned gc_marker;
466
467 assert(m);
468
469 if ((m->n_in_gc_queue < GC_QUEUE_ENTRIES_MAX) &&
470 (m->gc_queue_timestamp <= 0 ||
471 (m->gc_queue_timestamp + GC_QUEUE_USEC_MAX) > now(CLOCK_MONOTONIC)))
472 return 0;
473
474 log_debug("Running GC...");
475
476 m->gc_marker += _GC_OFFSET_MAX;
477 if (m->gc_marker + _GC_OFFSET_MAX <= _GC_OFFSET_MAX)
478 m->gc_marker = 1;
479
480 gc_marker = m->gc_marker;
481
482 while ((meta = m->gc_queue)) {
483 assert(meta->in_gc_queue);
484
485 unit_gc_sweep(UNIT(meta), gc_marker);
486
487 LIST_REMOVE(Meta, gc_queue, m->gc_queue, meta);
488 meta->in_gc_queue = false;
489
490 n++;
491
492 if (meta->gc_marker == gc_marker + GC_OFFSET_BAD ||
493 meta->gc_marker == gc_marker + GC_OFFSET_UNSURE) {
494 log_debug("Collecting %s", meta->id);
495 meta->gc_marker = gc_marker + GC_OFFSET_BAD;
496 unit_add_to_cleanup_queue(UNIT(meta));
497 }
498 }
499
500 m->n_in_gc_queue = 0;
501 m->gc_queue_timestamp = 0;
502
503 return n;
504 }
505
506 static void manager_clear_jobs_and_units(Manager *m) {
507 Job *j;
508 Unit *u;
509
510 assert(m);
511
512 while ((j = hashmap_first(m->transaction_jobs)))
513 job_free(j);
514
515 while ((u = hashmap_first(m->units)))
516 unit_free(u);
517 }
518
519 void manager_free(Manager *m) {
520 UnitType c;
521
522 assert(m);
523
524 manager_clear_jobs_and_units(m);
525
526 for (c = 0; c < _UNIT_TYPE_MAX; c++)
527 if (unit_vtable[c]->shutdown)
528 unit_vtable[c]->shutdown(m);
529
530 /* If we reexecute ourselves, we keep the root cgroup
531 * around */
532 manager_shutdown_cgroup(m, m->exit_code != MANAGER_REEXECUTE);
533
534 bus_done_api(m);
535 bus_done_system(m);
536
537 hashmap_free(m->units);
538 hashmap_free(m->jobs);
539 hashmap_free(m->transaction_jobs);
540 hashmap_free(m->watch_pids);
541 hashmap_free(m->watch_bus);
542
543 if (m->epoll_fd >= 0)
544 close_nointr_nofail(m->epoll_fd);
545 if (m->signal_watch.fd >= 0)
546 close_nointr_nofail(m->signal_watch.fd);
547
548 strv_free(m->unit_path);
549 strv_free(m->sysvinit_path);
550 strv_free(m->sysvrcnd_path);
551 strv_free(m->environment);
552
553 free(m->cgroup_controller);
554 free(m->cgroup_hierarchy);
555
556 hashmap_free(m->cgroup_bondings);
557
558 free(m);
559 }
560
561 int manager_enumerate(Manager *m) {
562 int r = 0, q;
563 UnitType c;
564
565 assert(m);
566
567 /* Let's ask every type to load all units from disk/kernel
568 * that it might know */
569 for (c = 0; c < _UNIT_TYPE_MAX; c++)
570 if (unit_vtable[c]->enumerate)
571 if ((q = unit_vtable[c]->enumerate(m)) < 0)
572 r = q;
573
574 manager_dispatch_load_queue(m);
575 return r;
576 }
577
578 int manager_coldplug(Manager *m) {
579 int r = 0, q;
580 Iterator i;
581 Unit *u;
582 char *k;
583
584 assert(m);
585
586 /* Then, let's set up their initial state. */
587 HASHMAP_FOREACH_KEY(u, k, m->units, i) {
588
589 /* ignore aliases */
590 if (u->meta.id != k)
591 continue;
592
593 if (UNIT_VTABLE(u)->coldplug)
594 if ((q = UNIT_VTABLE(u)->coldplug(u)) < 0)
595 r = q;
596 }
597
598 return r;
599 }
600
601 int manager_startup(Manager *m, FILE *serialization, FDSet *fds) {
602 int r, q;
603
604 assert(m);
605
606 /* First, enumerate what we can from all config files */
607 r = manager_enumerate(m);
608
609 /* Second, deserialize if there is something to deserialize */
610 if (serialization)
611 if ((q = manager_deserialize(m, serialization, fds)) < 0)
612 r = q;
613
614 /* Third, fire things up! */
615 if ((q = manager_coldplug(m)) < 0)
616 r = q;
617
618 /* Now that the initial devices are available, let's see if we
619 * can write the utmp file */
620 manager_write_utmp_reboot(m);
621
622 return r;
623 }
624
625 static void transaction_delete_job(Manager *m, Job *j, bool delete_dependencies) {
626 assert(m);
627 assert(j);
628
629 /* Deletes one job from the transaction */
630
631 manager_transaction_unlink_job(m, j, delete_dependencies);
632
633 if (!j->installed)
634 job_free(j);
635 }
636
637 static void transaction_delete_unit(Manager *m, Unit *u) {
638 Job *j;
639
640 /* Deletes all jobs associated with a certain unit from the
641 * transaction */
642
643 while ((j = hashmap_get(m->transaction_jobs, u)))
644 transaction_delete_job(m, j, true);
645 }
646
647 static void transaction_clean_dependencies(Manager *m) {
648 Iterator i;
649 Job *j;
650
651 assert(m);
652
653 /* Drops all dependencies of all installed jobs */
654
655 HASHMAP_FOREACH(j, m->jobs, i) {
656 while (j->subject_list)
657 job_dependency_free(j->subject_list);
658 while (j->object_list)
659 job_dependency_free(j->object_list);
660 }
661
662 assert(!m->transaction_anchor);
663 }
664
665 static void transaction_abort(Manager *m) {
666 Job *j;
667
668 assert(m);
669
670 while ((j = hashmap_first(m->transaction_jobs)))
671 if (j->installed)
672 transaction_delete_job(m, j, true);
673 else
674 job_free(j);
675
676 assert(hashmap_isempty(m->transaction_jobs));
677
678 transaction_clean_dependencies(m);
679 }
680
681 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
682 JobDependency *l;
683
684 assert(m);
685
686 /* A recursive sweep through the graph that marks all units
687 * that matter to the anchor job, i.e. are directly or
688 * indirectly a dependency of the anchor job via paths that
689 * are fully marked as mattering. */
690
691 if (j)
692 l = j->subject_list;
693 else
694 l = m->transaction_anchor;
695
696 LIST_FOREACH(subject, l, l) {
697
698 /* This link does not matter */
699 if (!l->matters)
700 continue;
701
702 /* This unit has already been marked */
703 if (l->object->generation == generation)
704 continue;
705
706 l->object->matters_to_anchor = true;
707 l->object->generation = generation;
708
709 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
710 }
711 }
712
713 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
714 JobDependency *l, *last;
715
716 assert(j);
717 assert(other);
718 assert(j->unit == other->unit);
719 assert(!j->installed);
720
721 /* Merges 'other' into 'j' and then deletes j. */
722
723 j->type = t;
724 j->state = JOB_WAITING;
725 j->override = j->override || other->override;
726
727 j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
728
729 /* Patch us in as new owner of the JobDependency objects */
730 last = NULL;
731 LIST_FOREACH(subject, l, other->subject_list) {
732 assert(l->subject == other);
733 l->subject = j;
734 last = l;
735 }
736
737 /* Merge both lists */
738 if (last) {
739 last->subject_next = j->subject_list;
740 if (j->subject_list)
741 j->subject_list->subject_prev = last;
742 j->subject_list = other->subject_list;
743 }
744
745 /* Patch us in as new owner of the JobDependency objects */
746 last = NULL;
747 LIST_FOREACH(object, l, other->object_list) {
748 assert(l->object == other);
749 l->object = j;
750 last = l;
751 }
752
753 /* Merge both lists */
754 if (last) {
755 last->object_next = j->object_list;
756 if (j->object_list)
757 j->object_list->object_prev = last;
758 j->object_list = other->object_list;
759 }
760
761 /* Kill the other job */
762 other->subject_list = NULL;
763 other->object_list = NULL;
764 transaction_delete_job(m, other, true);
765 }
766
767 static int delete_one_unmergeable_job(Manager *m, Job *j) {
768 Job *k;
769
770 assert(j);
771
772 /* Tries to delete one item in the linked list
773 * j->transaction_next->transaction_next->... that conflicts
774 * whith another one, in an attempt to make an inconsistent
775 * transaction work. */
776
777 /* We rely here on the fact that if a merged with b does not
778 * merge with c, either a or b merge with c neither */
779 LIST_FOREACH(transaction, j, j)
780 LIST_FOREACH(transaction, k, j->transaction_next) {
781 Job *d;
782
783 /* Is this one mergeable? Then skip it */
784 if (job_type_is_mergeable(j->type, k->type))
785 continue;
786
787 /* Ok, we found two that conflict, let's see if we can
788 * drop one of them */
789 if (!j->matters_to_anchor)
790 d = j;
791 else if (!k->matters_to_anchor)
792 d = k;
793 else
794 return -ENOEXEC;
795
796 /* Ok, we can drop one, so let's do so. */
797 log_debug("Trying to fix job merging by deleting job %s/%s", d->unit->meta.id, job_type_to_string(d->type));
798 transaction_delete_job(m, d, true);
799 return 0;
800 }
801
802 return -EINVAL;
803 }
804
805 static int transaction_merge_jobs(Manager *m) {
806 Job *j;
807 Iterator i;
808 int r;
809
810 assert(m);
811
812 /* First step, check whether any of the jobs for one specific
813 * task conflict. If so, try to drop one of them. */
814 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
815 JobType t;
816 Job *k;
817
818 t = j->type;
819 LIST_FOREACH(transaction, k, j->transaction_next) {
820 if ((r = job_type_merge(&t, k->type)) >= 0)
821 continue;
822
823 /* OK, we could not merge all jobs for this
824 * action. Let's see if we can get rid of one
825 * of them */
826
827 if ((r = delete_one_unmergeable_job(m, j)) >= 0)
828 /* Ok, we managed to drop one, now
829 * let's ask our callers to call us
830 * again after garbage collecting */
831 return -EAGAIN;
832
833 /* We couldn't merge anything. Failure */
834 return r;
835 }
836 }
837
838 /* Second step, merge the jobs. */
839 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
840 JobType t = j->type;
841 Job *k;
842
843 /* Merge all transactions */
844 LIST_FOREACH(transaction, k, j->transaction_next)
845 assert_se(job_type_merge(&t, k->type) == 0);
846
847 /* If an active job is mergeable, merge it too */
848 if (j->unit->meta.job)
849 job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
850
851 while ((k = j->transaction_next)) {
852 if (j->installed) {
853 transaction_merge_and_delete_job(m, k, j, t);
854 j = k;
855 } else
856 transaction_merge_and_delete_job(m, j, k, t);
857 }
858
859 assert(!j->transaction_next);
860 assert(!j->transaction_prev);
861 }
862
863 return 0;
864 }
865
866 static void transaction_drop_redundant(Manager *m) {
867 bool again;
868
869 assert(m);
870
871 /* Goes through the transaction and removes all jobs that are
872 * a noop */
873
874 do {
875 Job *j;
876 Iterator i;
877
878 again = false;
879
880 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
881 bool changes_something = false;
882 Job *k;
883
884 LIST_FOREACH(transaction, k, j) {
885
886 if (!job_is_anchor(k) &&
887 job_type_is_redundant(k->type, unit_active_state(k->unit)))
888 continue;
889
890 changes_something = true;
891 break;
892 }
893
894 if (changes_something)
895 continue;
896
897 log_debug("Found redundant job %s/%s, dropping.", j->unit->meta.id, job_type_to_string(j->type));
898 transaction_delete_job(m, j, false);
899 again = true;
900 break;
901 }
902
903 } while (again);
904 }
905
906 static bool unit_matters_to_anchor(Unit *u, Job *j) {
907 assert(u);
908 assert(!j->transaction_prev);
909
910 /* Checks whether at least one of the jobs for this unit
911 * matters to the anchor. */
912
913 LIST_FOREACH(transaction, j, j)
914 if (j->matters_to_anchor)
915 return true;
916
917 return false;
918 }
919
920 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation) {
921 Iterator i;
922 Unit *u;
923 int r;
924
925 assert(m);
926 assert(j);
927 assert(!j->transaction_prev);
928
929 /* Does a recursive sweep through the ordering graph, looking
930 * for a cycle. If we find cycle we try to break it. */
931
932 /* Did we find a cycle? */
933 if (j->marker && j->generation == generation) {
934 Job *k;
935
936 /* So, we already have been here. We have a
937 * cycle. Let's try to break it. We go backwards in
938 * our path and try to find a suitable job to
939 * remove. We use the marker to find our way back,
940 * since smart how we are we stored our way back in
941 * there. */
942
943 log_debug("Found ordering cycle on %s/%s", j->unit->meta.id, job_type_to_string(j->type));
944
945 for (k = from; k; k = (k->generation == generation ? k->marker : NULL)) {
946
947 log_debug("Walked on cycle path to %s/%s", k->unit->meta.id, job_type_to_string(k->type));
948
949 if (!k->installed &&
950 !unit_matters_to_anchor(k->unit, k)) {
951 /* Ok, we can drop this one, so let's
952 * do so. */
953 log_debug("Breaking order cycle by deleting job %s/%s", k->unit->meta.id, job_type_to_string(k->type));
954 transaction_delete_unit(m, k->unit);
955 return -EAGAIN;
956 }
957
958 /* Check if this in fact was the beginning of
959 * the cycle */
960 if (k == j)
961 break;
962 }
963
964 log_debug("Unable to break cycle");
965
966 return -ENOEXEC;
967 }
968
969 /* Make the marker point to where we come from, so that we can
970 * find our way backwards if we want to break a cycle */
971 j->marker = from;
972 j->generation = generation;
973
974 /* We assume that the the dependencies are bidirectional, and
975 * hence can ignore UNIT_AFTER */
976 SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
977 Job *o;
978
979 /* Is there a job for this unit? */
980 if (!(o = hashmap_get(m->transaction_jobs, u)))
981
982 /* Ok, there is no job for this in the
983 * transaction, but maybe there is already one
984 * running? */
985 if (!(o = u->meta.job))
986 continue;
987
988 if ((r = transaction_verify_order_one(m, o, j, generation)) < 0)
989 return r;
990 }
991
992 /* Ok, let's backtrack, and remember that this entry is not on
993 * our path anymore. */
994 j->marker = NULL;
995
996 return 0;
997 }
998
999 static int transaction_verify_order(Manager *m, unsigned *generation) {
1000 Job *j;
1001 int r;
1002 Iterator i;
1003
1004 assert(m);
1005 assert(generation);
1006
1007 /* Check if the ordering graph is cyclic. If it is, try to fix
1008 * that up by dropping one of the jobs. */
1009
1010 HASHMAP_FOREACH(j, m->transaction_jobs, i)
1011 if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0)
1012 return r;
1013
1014 return 0;
1015 }
1016
1017 static void transaction_collect_garbage(Manager *m) {
1018 bool again;
1019
1020 assert(m);
1021
1022 /* Drop jobs that are not required by any other job */
1023
1024 do {
1025 Iterator i;
1026 Job *j;
1027
1028 again = false;
1029
1030 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1031 if (j->object_list)
1032 continue;
1033
1034 log_debug("Garbage collecting job %s/%s", j->unit->meta.id, job_type_to_string(j->type));
1035 transaction_delete_job(m, j, true);
1036 again = true;
1037 break;
1038 }
1039
1040 } while (again);
1041 }
1042
1043 static int transaction_is_destructive(Manager *m) {
1044 Iterator i;
1045 Job *j;
1046
1047 assert(m);
1048
1049 /* Checks whether applying this transaction means that
1050 * existing jobs would be replaced */
1051
1052 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1053
1054 /* Assume merged */
1055 assert(!j->transaction_prev);
1056 assert(!j->transaction_next);
1057
1058 if (j->unit->meta.job &&
1059 j->unit->meta.job != j &&
1060 !job_type_is_superset(j->type, j->unit->meta.job->type))
1061 return -EEXIST;
1062 }
1063
1064 return 0;
1065 }
1066
1067 static void transaction_minimize_impact(Manager *m) {
1068 bool again;
1069 assert(m);
1070
1071 /* Drops all unnecessary jobs that reverse already active jobs
1072 * or that stop a running service. */
1073
1074 do {
1075 Job *j;
1076 Iterator i;
1077
1078 again = false;
1079
1080 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1081 LIST_FOREACH(transaction, j, j) {
1082 bool stops_running_service, changes_existing_job;
1083
1084 /* If it matters, we shouldn't drop it */
1085 if (j->matters_to_anchor)
1086 continue;
1087
1088 /* Would this stop a running service?
1089 * Would this change an existing job?
1090 * If so, let's drop this entry */
1091
1092 stops_running_service =
1093 j->type == JOB_STOP && UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(j->unit));
1094
1095 changes_existing_job =
1096 j->unit->meta.job && job_type_is_conflicting(j->type, j->unit->meta.job->state);
1097
1098 if (!stops_running_service && !changes_existing_job)
1099 continue;
1100
1101 if (stops_running_service)
1102 log_debug("%s/%s would stop a running service.", j->unit->meta.id, job_type_to_string(j->type));
1103
1104 if (changes_existing_job)
1105 log_debug("%s/%s would change existing job.", j->unit->meta.id, job_type_to_string(j->type));
1106
1107 /* Ok, let's get rid of this */
1108 log_debug("Deleting %s/%s to minimize impact.", j->unit->meta.id, job_type_to_string(j->type));
1109
1110 transaction_delete_job(m, j, true);
1111 again = true;
1112 break;
1113 }
1114
1115 if (again)
1116 break;
1117 }
1118
1119 } while (again);
1120 }
1121
1122 static int transaction_apply(Manager *m) {
1123 Iterator i;
1124 Job *j;
1125 int r;
1126
1127 /* Moves the transaction jobs to the set of active jobs */
1128
1129 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1130 /* Assume merged */
1131 assert(!j->transaction_prev);
1132 assert(!j->transaction_next);
1133
1134 if (j->installed)
1135 continue;
1136
1137 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
1138 goto rollback;
1139 }
1140
1141 while ((j = hashmap_steal_first(m->transaction_jobs))) {
1142 if (j->installed)
1143 continue;
1144
1145 if (j->unit->meta.job)
1146 job_free(j->unit->meta.job);
1147
1148 j->unit->meta.job = j;
1149 j->installed = true;
1150
1151 /* We're fully installed. Now let's free data we don't
1152 * need anymore. */
1153
1154 assert(!j->transaction_next);
1155 assert(!j->transaction_prev);
1156
1157 job_add_to_run_queue(j);
1158 job_add_to_dbus_queue(j);
1159 }
1160
1161 /* As last step, kill all remaining job dependencies. */
1162 transaction_clean_dependencies(m);
1163
1164 return 0;
1165
1166 rollback:
1167
1168 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
1169 if (j->installed)
1170 continue;
1171
1172 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
1173 }
1174
1175 return r;
1176 }
1177
1178 static int transaction_activate(Manager *m, JobMode mode) {
1179 int r;
1180 unsigned generation = 1;
1181
1182 assert(m);
1183
1184 /* This applies the changes recorded in transaction_jobs to
1185 * the actual list of jobs, if possible. */
1186
1187 /* First step: figure out which jobs matter */
1188 transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
1189
1190 /* Second step: Try not to stop any running services if
1191 * we don't have to. Don't try to reverse running
1192 * jobs if we don't have to. */
1193 transaction_minimize_impact(m);
1194
1195 /* Third step: Drop redundant jobs */
1196 transaction_drop_redundant(m);
1197
1198 for (;;) {
1199 /* Fourth step: Let's remove unneeded jobs that might
1200 * be lurking. */
1201 transaction_collect_garbage(m);
1202
1203 /* Fifth step: verify order makes sense and correct
1204 * cycles if necessary and possible */
1205 if ((r = transaction_verify_order(m, &generation)) >= 0)
1206 break;
1207
1208 if (r != -EAGAIN) {
1209 log_debug("Requested transaction contains an unfixable cyclic ordering dependency: %s", strerror(-r));
1210 goto rollback;
1211 }
1212
1213 /* Let's see if the resulting transaction ordering
1214 * graph is still cyclic... */
1215 }
1216
1217 for (;;) {
1218 /* Sixth step: let's drop unmergeable entries if
1219 * necessary and possible, merge entries we can
1220 * merge */
1221 if ((r = transaction_merge_jobs(m)) >= 0)
1222 break;
1223
1224 if (r != -EAGAIN) {
1225 log_debug("Requested transaction contains unmergable jobs: %s", strerror(-r));
1226 goto rollback;
1227 }
1228
1229 /* Seventh step: an entry got dropped, let's garbage
1230 * collect its dependencies. */
1231 transaction_collect_garbage(m);
1232
1233 /* Let's see if the resulting transaction still has
1234 * unmergeable entries ... */
1235 }
1236
1237 /* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */
1238 transaction_drop_redundant(m);
1239
1240 /* Ninth step: check whether we can actually apply this */
1241 if (mode == JOB_FAIL)
1242 if ((r = transaction_is_destructive(m)) < 0) {
1243 log_debug("Requested transaction contradicts existing jobs: %s", strerror(-r));
1244 goto rollback;
1245 }
1246
1247 /* Tenth step: apply changes */
1248 if ((r = transaction_apply(m)) < 0) {
1249 log_debug("Failed to apply transaction: %s", strerror(-r));
1250 goto rollback;
1251 }
1252
1253 assert(hashmap_isempty(m->transaction_jobs));
1254 assert(!m->transaction_anchor);
1255
1256 return 0;
1257
1258 rollback:
1259 transaction_abort(m);
1260 return r;
1261 }
1262
1263 static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool override, bool *is_new) {
1264 Job *j, *f;
1265 int r;
1266
1267 assert(m);
1268 assert(unit);
1269
1270 /* Looks for an axisting prospective job and returns that. If
1271 * it doesn't exist it is created and added to the prospective
1272 * jobs list. */
1273
1274 f = hashmap_get(m->transaction_jobs, unit);
1275
1276 LIST_FOREACH(transaction, j, f) {
1277 assert(j->unit == unit);
1278
1279 if (j->type == type) {
1280 if (is_new)
1281 *is_new = false;
1282 return j;
1283 }
1284 }
1285
1286 if (unit->meta.job && unit->meta.job->type == type)
1287 j = unit->meta.job;
1288 else if (!(j = job_new(m, type, unit)))
1289 return NULL;
1290
1291 j->generation = 0;
1292 j->marker = NULL;
1293 j->matters_to_anchor = false;
1294 j->override = override;
1295
1296 LIST_PREPEND(Job, transaction, f, j);
1297
1298 if ((r = hashmap_replace(m->transaction_jobs, unit, f)) < 0) {
1299 job_free(j);
1300 return NULL;
1301 }
1302
1303 if (is_new)
1304 *is_new = true;
1305
1306 log_debug("Added job %s/%s to transaction.", unit->meta.id, job_type_to_string(type));
1307
1308 return j;
1309 }
1310
1311 void manager_transaction_unlink_job(Manager *m, Job *j, bool delete_dependencies) {
1312 assert(m);
1313 assert(j);
1314
1315 if (j->transaction_prev)
1316 j->transaction_prev->transaction_next = j->transaction_next;
1317 else if (j->transaction_next)
1318 hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
1319 else
1320 hashmap_remove_value(m->transaction_jobs, j->unit, j);
1321
1322 if (j->transaction_next)
1323 j->transaction_next->transaction_prev = j->transaction_prev;
1324
1325 j->transaction_prev = j->transaction_next = NULL;
1326
1327 while (j->subject_list)
1328 job_dependency_free(j->subject_list);
1329
1330 while (j->object_list) {
1331 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
1332
1333 job_dependency_free(j->object_list);
1334
1335 if (other && delete_dependencies) {
1336 log_debug("Deleting job %s/%s as dependency of job %s/%s",
1337 other->unit->meta.id, job_type_to_string(other->type),
1338 j->unit->meta.id, job_type_to_string(j->type));
1339 transaction_delete_job(m, other, delete_dependencies);
1340 }
1341 }
1342 }
1343
1344 static int transaction_add_job_and_dependencies(
1345 Manager *m,
1346 JobType type,
1347 Unit *unit,
1348 Job *by,
1349 bool matters,
1350 bool override,
1351 Job **_ret) {
1352 Job *ret;
1353 Iterator i;
1354 Unit *dep;
1355 int r;
1356 bool is_new;
1357
1358 assert(m);
1359 assert(type < _JOB_TYPE_MAX);
1360 assert(unit);
1361
1362 if (unit->meta.load_state != UNIT_LOADED)
1363 return -EINVAL;
1364
1365 if (!unit_job_is_applicable(unit, type))
1366 return -EBADR;
1367
1368 /* First add the job. */
1369 if (!(ret = transaction_add_one_job(m, type, unit, override, &is_new)))
1370 return -ENOMEM;
1371
1372 /* Then, add a link to the job. */
1373 if (!job_dependency_new(by, ret, matters))
1374 return -ENOMEM;
1375
1376 if (is_new) {
1377 /* Finally, recursively add in all dependencies. */
1378 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
1379 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
1380 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
1381 goto fail;
1382
1383 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
1384 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !override, override, NULL)) < 0 && r != -EBADR)
1385 log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
1386
1387 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
1388 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, false, NULL)) < 0)
1389 log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
1390
1391 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
1392 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
1393 goto fail;
1394
1395 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE_OVERRIDABLE], i)
1396 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !override, override, NULL)) < 0 && r != -EBADR)
1397 log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
1398
1399 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
1400 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
1401 goto fail;
1402
1403 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
1404
1405 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
1406 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
1407 goto fail;
1408 }
1409
1410 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
1411 }
1412
1413 if (_ret)
1414 *_ret = ret;
1415
1416 return 0;
1417
1418 fail:
1419 return r;
1420 }
1421
1422 static int transaction_add_isolate_jobs(Manager *m) {
1423 Iterator i;
1424 Unit *u;
1425 char *k;
1426 int r;
1427
1428 assert(m);
1429
1430 HASHMAP_FOREACH_KEY(u, k, m->units, i) {
1431
1432 /* ignore aliases */
1433 if (u->meta.id != k)
1434 continue;
1435
1436 if (UNIT_VTABLE(u)->no_isolate)
1437 continue;
1438
1439 /* No need to stop inactive jobs */
1440 if (unit_active_state(u) == UNIT_INACTIVE)
1441 continue;
1442
1443 /* Is there already something listed for this? */
1444 if (hashmap_get(m->transaction_jobs, u))
1445 continue;
1446
1447 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, u, NULL, true, false, NULL)) < 0)
1448 log_warning("Cannot add isolate job for unit %s, ignoring: %s", u->meta.id, strerror(-r));
1449 }
1450
1451 return 0;
1452 }
1453
1454 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool override, Job **_ret) {
1455 int r;
1456 Job *ret;
1457
1458 assert(m);
1459 assert(type < _JOB_TYPE_MAX);
1460 assert(unit);
1461 assert(mode < _JOB_MODE_MAX);
1462
1463 if (mode == JOB_ISOLATE && type != JOB_START)
1464 return -EINVAL;
1465
1466 log_debug("Trying to enqueue job %s/%s", unit->meta.id, job_type_to_string(type));
1467
1468 if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, override, &ret)) < 0) {
1469 transaction_abort(m);
1470 return r;
1471 }
1472
1473 if (mode == JOB_ISOLATE)
1474 if ((r = transaction_add_isolate_jobs(m)) < 0) {
1475 transaction_abort(m);
1476 return r;
1477 }
1478
1479 if ((r = transaction_activate(m, mode)) < 0)
1480 return r;
1481
1482 log_debug("Enqueued job %s/%s as %u", unit->meta.id, job_type_to_string(type), (unsigned) ret->id);
1483
1484 if (_ret)
1485 *_ret = ret;
1486
1487 return 0;
1488 }
1489
1490 int manager_add_job_by_name(Manager *m, JobType type, const char *name, JobMode mode, bool override, Job **_ret) {
1491 Unit *unit;
1492 int r;
1493
1494 assert(m);
1495 assert(type < _JOB_TYPE_MAX);
1496 assert(name);
1497 assert(mode < _JOB_MODE_MAX);
1498
1499 if ((r = manager_load_unit(m, name, NULL, &unit)) < 0)
1500 return r;
1501
1502 return manager_add_job(m, type, unit, mode, override, _ret);
1503 }
1504
1505 Job *manager_get_job(Manager *m, uint32_t id) {
1506 assert(m);
1507
1508 return hashmap_get(m->jobs, UINT32_TO_PTR(id));
1509 }
1510
1511 Unit *manager_get_unit(Manager *m, const char *name) {
1512 assert(m);
1513 assert(name);
1514
1515 return hashmap_get(m->units, name);
1516 }
1517
1518 unsigned manager_dispatch_load_queue(Manager *m) {
1519 Meta *meta;
1520 unsigned n = 0;
1521
1522 assert(m);
1523
1524 /* Make sure we are not run recursively */
1525 if (m->dispatching_load_queue)
1526 return 0;
1527
1528 m->dispatching_load_queue = true;
1529
1530 /* Dispatches the load queue. Takes a unit from the queue and
1531 * tries to load its data until the queue is empty */
1532
1533 while ((meta = m->load_queue)) {
1534 assert(meta->in_load_queue);
1535
1536 unit_load(UNIT(meta));
1537 n++;
1538 }
1539
1540 m->dispatching_load_queue = false;
1541 return n;
1542 }
1543
1544 int manager_load_unit_prepare(Manager *m, const char *name, const char *path, Unit **_ret) {
1545 Unit *ret;
1546 int r;
1547
1548 assert(m);
1549 assert(name || path);
1550
1551 /* This will prepare the unit for loading, but not actually
1552 * load anything from disk. */
1553
1554 if (path && !is_path(path))
1555 return -EINVAL;
1556
1557 if (!name)
1558 name = file_name_from_path(path);
1559
1560 if (!unit_name_is_valid(name))
1561 return -EINVAL;
1562
1563 if ((ret = manager_get_unit(m, name))) {
1564 *_ret = ret;
1565 return 0;
1566 }
1567
1568 if (!(ret = unit_new(m)))
1569 return -ENOMEM;
1570
1571 if (path)
1572 if (!(ret->meta.fragment_path = strdup(path))) {
1573 unit_free(ret);
1574 return -ENOMEM;
1575 }
1576
1577 if ((r = unit_add_name(ret, name)) < 0) {
1578 unit_free(ret);
1579 return r;
1580 }
1581
1582 unit_add_to_load_queue(ret);
1583 unit_add_to_dbus_queue(ret);
1584
1585 if (_ret)
1586 *_ret = ret;
1587
1588 return 0;
1589 }
1590
1591 int manager_load_unit(Manager *m, const char *name, const char *path, Unit **_ret) {
1592 Unit *ret;
1593 int r;
1594
1595 assert(m);
1596
1597 /* This will load the service information files, but not actually
1598 * start any services or anything. */
1599
1600 if ((r = manager_load_unit_prepare(m, name, path, &ret)) < 0)
1601 return r;
1602
1603 manager_dispatch_load_queue(m);
1604
1605 if (_ret)
1606 *_ret = unit_follow_merge(ret);
1607
1608 return 0;
1609 }
1610
1611 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
1612 Iterator i;
1613 Job *j;
1614
1615 assert(s);
1616 assert(f);
1617
1618 HASHMAP_FOREACH(j, s->jobs, i)
1619 job_dump(j, f, prefix);
1620 }
1621
1622 void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
1623 Iterator i;
1624 Unit *u;
1625 const char *t;
1626
1627 assert(s);
1628 assert(f);
1629
1630 HASHMAP_FOREACH_KEY(u, t, s->units, i)
1631 if (u->meta.id == t)
1632 unit_dump(u, f, prefix);
1633 }
1634
1635 void manager_clear_jobs(Manager *m) {
1636 Job *j;
1637
1638 assert(m);
1639
1640 transaction_abort(m);
1641
1642 while ((j = hashmap_first(m->jobs)))
1643 job_free(j);
1644 }
1645
1646 unsigned manager_dispatch_run_queue(Manager *m) {
1647 Job *j;
1648 unsigned n = 0;
1649
1650 if (m->dispatching_run_queue)
1651 return 0;
1652
1653 m->dispatching_run_queue = true;
1654
1655 while ((j = m->run_queue)) {
1656 assert(j->installed);
1657 assert(j->in_run_queue);
1658
1659 job_run_and_invalidate(j);
1660 n++;
1661 }
1662
1663 m->dispatching_run_queue = false;
1664 return n;
1665 }
1666
1667 unsigned manager_dispatch_dbus_queue(Manager *m) {
1668 Job *j;
1669 Meta *meta;
1670 unsigned n = 0;
1671
1672 assert(m);
1673
1674 if (m->dispatching_dbus_queue)
1675 return 0;
1676
1677 m->dispatching_dbus_queue = true;
1678
1679 while ((meta = m->dbus_unit_queue)) {
1680 assert(meta->in_dbus_queue);
1681
1682 bus_unit_send_change_signal(UNIT(meta));
1683 n++;
1684 }
1685
1686 while ((j = m->dbus_job_queue)) {
1687 assert(j->in_dbus_queue);
1688
1689 bus_job_send_change_signal(j);
1690 n++;
1691 }
1692
1693 m->dispatching_dbus_queue = false;
1694 return n;
1695 }
1696
1697 static int manager_dispatch_sigchld(Manager *m) {
1698 assert(m);
1699
1700 for (;;) {
1701 siginfo_t si;
1702 Unit *u;
1703
1704 zero(si);
1705
1706 /* First we call waitd() for a PID and do not reap the
1707 * zombie. That way we can still access /proc/$PID for
1708 * it while it is a zombie. */
1709 if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG|WNOWAIT) < 0) {
1710
1711 if (errno == ECHILD)
1712 break;
1713
1714 if (errno == EINTR)
1715 continue;
1716
1717 return -errno;
1718 }
1719
1720 if (si.si_pid <= 0)
1721 break;
1722
1723 if (si.si_code == CLD_EXITED || si.si_code == CLD_KILLED || si.si_code == CLD_DUMPED) {
1724 char *name = NULL;
1725
1726 get_process_name(si.si_pid, &name);
1727 log_debug("Got SIGCHLD for process %llu (%s)", (unsigned long long) si.si_pid, strna(name));
1728 free(name);
1729 }
1730
1731 /* And now, we actually reap the zombie. */
1732 if (waitid(P_PID, si.si_pid, &si, WEXITED) < 0) {
1733 if (errno == EINTR)
1734 continue;
1735
1736 return -errno;
1737 }
1738
1739 if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
1740 continue;
1741
1742 log_debug("Child %llu died (code=%s, status=%i/%s)",
1743 (long long unsigned) si.si_pid,
1744 sigchld_code_to_string(si.si_code),
1745 si.si_status,
1746 strna(si.si_code == CLD_EXITED ? exit_status_to_string(si.si_status) : strsignal(si.si_status)));
1747
1748 if (!(u = hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid))))
1749 continue;
1750
1751 log_debug("Child %llu belongs to %s", (long long unsigned) si.si_pid, u->meta.id);
1752
1753 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
1754 }
1755
1756 return 0;
1757 }
1758
1759 static void manager_start_target(Manager *m, const char *name) {
1760 int r;
1761
1762 if ((r = manager_add_job_by_name(m, JOB_START, name, JOB_REPLACE, true, NULL)) < 0)
1763 log_error("Failed to enqueue %s job: %s", name, strerror(-r));
1764 }
1765
1766 static int manager_process_signal_fd(Manager *m) {
1767 ssize_t n;
1768 struct signalfd_siginfo sfsi;
1769 bool sigchld = false;
1770
1771 assert(m);
1772
1773 for (;;) {
1774 if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
1775
1776 if (n >= 0)
1777 return -EIO;
1778
1779 if (errno == EAGAIN)
1780 break;
1781
1782 return -errno;
1783 }
1784
1785 switch (sfsi.ssi_signo) {
1786
1787 case SIGCHLD:
1788 sigchld = true;
1789 break;
1790
1791 case SIGTERM:
1792 if (m->running_as == MANAGER_INIT)
1793 /* This is for compatibility with the
1794 * original sysvinit */
1795 m->exit_code = MANAGER_REEXECUTE;
1796 else
1797 m->exit_code = MANAGER_EXIT;
1798
1799 return 0;
1800
1801 case SIGINT:
1802 if (m->running_as == MANAGER_INIT) {
1803 manager_start_target(m, SPECIAL_CTRL_ALT_DEL_TARGET);
1804 break;
1805 }
1806
1807 m->exit_code = MANAGER_EXIT;
1808 return 0;
1809
1810 case SIGWINCH:
1811 if (m->running_as == MANAGER_INIT)
1812 manager_start_target(m, SPECIAL_KBREQUEST_TARGET);
1813
1814 /* This is a nop on non-init */
1815 break;
1816
1817 case SIGPWR:
1818 if (m->running_as == MANAGER_INIT)
1819 manager_start_target(m, SPECIAL_SIGPWR_TARGET);
1820
1821 /* This is a nop on non-init */
1822 break;
1823
1824 case SIGUSR1: {
1825 Unit *u;
1826
1827 u = manager_get_unit(m, SPECIAL_DBUS_SERVICE);
1828
1829 if (!u || UNIT_IS_ACTIVE_OR_RELOADING(unit_active_state(u))) {
1830 log_info("Trying to reconnect to bus...");
1831 bus_init_system(m);
1832 bus_init_api(m);
1833 }
1834
1835 if (!u || !UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u))) {
1836 log_info("Loading D-Bus service...");
1837 manager_start_target(m, SPECIAL_DBUS_SERVICE);
1838 }
1839
1840 break;
1841 }
1842
1843 case SIGUSR2:
1844 manager_dump_units(m, stdout, "\t");
1845 manager_dump_jobs(m, stdout, "\t");
1846 break;
1847
1848 case SIGHUP:
1849 m->exit_code = MANAGER_RELOAD;
1850 break;
1851
1852 default:
1853 log_info("Got unhandled signal <%s>.", strsignal(sfsi.ssi_signo));
1854 }
1855 }
1856
1857 if (sigchld)
1858 return manager_dispatch_sigchld(m);
1859
1860 return 0;
1861 }
1862
1863 static int process_event(Manager *m, struct epoll_event *ev) {
1864 int r;
1865 Watch *w;
1866
1867 assert(m);
1868 assert(ev);
1869
1870 assert(w = ev->data.ptr);
1871
1872 switch (w->type) {
1873
1874 case WATCH_SIGNAL:
1875
1876 /* An incoming signal? */
1877 if (ev->events != EPOLLIN)
1878 return -EINVAL;
1879
1880 if ((r = manager_process_signal_fd(m)) < 0)
1881 return r;
1882
1883 break;
1884
1885 case WATCH_FD:
1886
1887 /* Some fd event, to be dispatched to the units */
1888 UNIT_VTABLE(w->data.unit)->fd_event(w->data.unit, w->fd, ev->events, w);
1889 break;
1890
1891 case WATCH_TIMER: {
1892 uint64_t v;
1893 ssize_t k;
1894
1895 /* Some timer event, to be dispatched to the units */
1896 if ((k = read(w->fd, &v, sizeof(v))) != sizeof(v)) {
1897
1898 if (k < 0 && (errno == EINTR || errno == EAGAIN))
1899 break;
1900
1901 return k < 0 ? -errno : -EIO;
1902 }
1903
1904 UNIT_VTABLE(w->data.unit)->timer_event(w->data.unit, v, w);
1905 break;
1906 }
1907
1908 case WATCH_MOUNT:
1909 /* Some mount table change, intended for the mount subsystem */
1910 mount_fd_event(m, ev->events);
1911 break;
1912
1913 case WATCH_UDEV:
1914 /* Some notification from udev, intended for the device subsystem */
1915 device_fd_event(m, ev->events);
1916 break;
1917
1918 case WATCH_DBUS_WATCH:
1919 bus_watch_event(m, w, ev->events);
1920 break;
1921
1922 case WATCH_DBUS_TIMEOUT:
1923 bus_timeout_event(m, w, ev->events);
1924 break;
1925
1926 default:
1927 assert_not_reached("Unknown epoll event type.");
1928 }
1929
1930 return 0;
1931 }
1932
1933 int manager_loop(Manager *m) {
1934 int r;
1935
1936 RATELIMIT_DEFINE(rl, 1*USEC_PER_SEC, 1000);
1937
1938 assert(m);
1939 m->exit_code = MANAGER_RUNNING;
1940
1941 while (m->exit_code == MANAGER_RUNNING) {
1942 struct epoll_event event;
1943 int n;
1944
1945 if (!ratelimit_test(&rl)) {
1946 /* Yay, something is going seriously wrong, pause a little */
1947 log_warning("Looping too fast. Throttling execution a little.");
1948 sleep(1);
1949 }
1950
1951 if (manager_dispatch_cleanup_queue(m) > 0)
1952 continue;
1953
1954 if (manager_dispatch_gc_queue(m) > 0)
1955 continue;
1956
1957 if (manager_dispatch_load_queue(m) > 0)
1958 continue;
1959
1960 if (manager_dispatch_run_queue(m) > 0)
1961 continue;
1962
1963 if (bus_dispatch(m) > 0)
1964 continue;
1965
1966 if (manager_dispatch_dbus_queue(m) > 0)
1967 continue;
1968
1969 if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) {
1970
1971 if (errno == EINTR)
1972 continue;
1973
1974 return -errno;
1975 }
1976
1977 assert(n == 1);
1978
1979 if ((r = process_event(m, &event)) < 0)
1980 return r;
1981 }
1982
1983 return m->exit_code;
1984 }
1985
1986 int manager_get_unit_from_dbus_path(Manager *m, const char *s, Unit **_u) {
1987 char *n;
1988 Unit *u;
1989
1990 assert(m);
1991 assert(s);
1992 assert(_u);
1993
1994 if (!startswith(s, "/org/freedesktop/systemd1/unit/"))
1995 return -EINVAL;
1996
1997 if (!(n = bus_path_unescape(s+31)))
1998 return -ENOMEM;
1999
2000 u = manager_get_unit(m, n);
2001 free(n);
2002
2003 if (!u)
2004 return -ENOENT;
2005
2006 *_u = u;
2007
2008 return 0;
2009 }
2010
2011 int manager_get_job_from_dbus_path(Manager *m, const char *s, Job **_j) {
2012 Job *j;
2013 unsigned id;
2014 int r;
2015
2016 assert(m);
2017 assert(s);
2018 assert(_j);
2019
2020 if (!startswith(s, "/org/freedesktop/systemd1/job/"))
2021 return -EINVAL;
2022
2023 if ((r = safe_atou(s + 30, &id)) < 0)
2024 return r;
2025
2026 if (!(j = manager_get_job(m, id)))
2027 return -ENOENT;
2028
2029 *_j = j;
2030
2031 return 0;
2032 }
2033
2034 static bool manager_utmp_good(Manager *m) {
2035 int r;
2036
2037 assert(m);
2038
2039 if ((r = mount_path_is_mounted(m, _PATH_UTMPX)) <= 0) {
2040
2041 if (r < 0)
2042 log_warning("Failed to determine whether " _PATH_UTMPX " is mounted: %s", strerror(-r));
2043
2044 return false;
2045 }
2046
2047 return true;
2048 }
2049
2050 void manager_write_utmp_reboot(Manager *m) {
2051 int r;
2052
2053 assert(m);
2054
2055 if (m->utmp_reboot_written)
2056 return;
2057
2058 if (m->running_as != MANAGER_INIT)
2059 return;
2060
2061 if (!manager_utmp_good(m))
2062 return;
2063
2064 if ((r = utmp_put_reboot(m->boot_timestamp)) < 0) {
2065
2066 if (r != -ENOENT && r != -EROFS)
2067 log_warning("Failed to write utmp/wtmp: %s", strerror(-r));
2068
2069 return;
2070 }
2071
2072 m->utmp_reboot_written = true;
2073 }
2074
2075 void manager_write_utmp_runlevel(Manager *m, Unit *u) {
2076 int runlevel, r;
2077
2078 assert(m);
2079 assert(u);
2080
2081 if (u->meta.type != UNIT_TARGET)
2082 return;
2083
2084 if (m->running_as != MANAGER_INIT)
2085 return;
2086
2087 if (!manager_utmp_good(m))
2088 return;
2089
2090 if ((runlevel = target_get_runlevel(TARGET(u))) <= 0)
2091 return;
2092
2093 if ((r = utmp_put_runlevel(0, runlevel, 0)) < 0) {
2094
2095 if (r != -ENOENT && r != -EROFS)
2096 log_warning("Failed to write utmp/wtmp: %s", strerror(-r));
2097 }
2098 }
2099
2100 void manager_dispatch_bus_name_owner_changed(
2101 Manager *m,
2102 const char *name,
2103 const char* old_owner,
2104 const char *new_owner) {
2105
2106 Unit *u;
2107
2108 assert(m);
2109 assert(name);
2110
2111 if (!(u = hashmap_get(m->watch_bus, name)))
2112 return;
2113
2114 UNIT_VTABLE(u)->bus_name_owner_change(u, name, old_owner, new_owner);
2115 }
2116
2117 void manager_dispatch_bus_query_pid_done(
2118 Manager *m,
2119 const char *name,
2120 pid_t pid) {
2121
2122 Unit *u;
2123
2124 assert(m);
2125 assert(name);
2126 assert(pid >= 1);
2127
2128 if (!(u = hashmap_get(m->watch_bus, name)))
2129 return;
2130
2131 UNIT_VTABLE(u)->bus_query_pid_done(u, name, pid);
2132 }
2133
2134 int manager_open_serialization(FILE **_f) {
2135 char *path;
2136 mode_t saved_umask;
2137 int fd;
2138 FILE *f;
2139
2140 assert(_f);
2141
2142 if (asprintf(&path, "/dev/shm/systemd-%u.dump-XXXXXX", (unsigned) getpid()) < 0)
2143 return -ENOMEM;
2144
2145 saved_umask = umask(0077);
2146 fd = mkostemp(path, O_RDWR|O_CLOEXEC);
2147 umask(saved_umask);
2148
2149 if (fd < 0) {
2150 free(path);
2151 return -errno;
2152 }
2153
2154 unlink(path);
2155
2156 log_debug("Serializing state to %s", path);
2157 free(path);
2158
2159 if (!(f = fdopen(fd, "w+")) < 0)
2160 return -errno;
2161
2162 *_f = f;
2163
2164 return 0;
2165 }
2166
2167 int manager_serialize(Manager *m, FILE *f, FDSet *fds) {
2168 Iterator i;
2169 Unit *u;
2170 const char *t;
2171 int r;
2172
2173 assert(m);
2174 assert(f);
2175 assert(fds);
2176
2177 HASHMAP_FOREACH_KEY(u, t, m->units, i) {
2178 if (u->meta.id != t)
2179 continue;
2180
2181 if (!unit_can_serialize(u))
2182 continue;
2183
2184 /* Start marker */
2185 fputs(u->meta.id, f);
2186 fputc('\n', f);
2187
2188 if ((r = unit_serialize(u, f, fds)) < 0)
2189 return r;
2190 }
2191
2192 if (ferror(f))
2193 return -EIO;
2194
2195 return 0;
2196 }
2197
2198 int manager_deserialize(Manager *m, FILE *f, FDSet *fds) {
2199 int r = 0;
2200
2201 assert(m);
2202 assert(f);
2203
2204 log_debug("Deserializing state...");
2205
2206 for (;;) {
2207 Unit *u;
2208 char name[UNIT_NAME_MAX+2];
2209
2210 /* Start marker */
2211 if (!fgets(name, sizeof(name), f)) {
2212 if (feof(f))
2213 break;
2214
2215 return -errno;
2216 }
2217
2218 char_array_0(name);
2219
2220 if ((r = manager_load_unit(m, strstrip(name), NULL, &u)) < 0)
2221 return r;
2222
2223 if ((r = unit_deserialize(u, f, fds)) < 0)
2224 return r;
2225 }
2226
2227 if (ferror(f))
2228 return -EIO;
2229
2230 return 0;
2231 }
2232
2233 int manager_reload(Manager *m) {
2234 int r, q;
2235 FILE *f;
2236 FDSet *fds;
2237
2238 assert(m);
2239
2240 if ((r = manager_open_serialization(&f)) < 0)
2241 return r;
2242
2243 if (!(fds = fdset_new())) {
2244 r = -ENOMEM;
2245 goto finish;
2246 }
2247
2248 if ((r = manager_serialize(m, f, fds)) < 0)
2249 goto finish;
2250
2251 if (fseeko(f, 0, SEEK_SET) < 0) {
2252 r = -errno;
2253 goto finish;
2254 }
2255
2256 /* From here on there is no way back. */
2257 manager_clear_jobs_and_units(m);
2258
2259 /* First, enumerate what we can from all config files */
2260 if ((q = manager_enumerate(m)) < 0)
2261 r = q;
2262
2263 /* Second, deserialize our stored data */
2264 if ((q = manager_deserialize(m, f, fds)) < 0)
2265 r = q;
2266
2267 fclose(f);
2268 f = NULL;
2269
2270 /* Third, fire things up! */
2271 if ((q = manager_coldplug(m)) < 0)
2272 r = q;
2273
2274 finish:
2275 if (f)
2276 fclose(f);
2277
2278 if (fds)
2279 fdset_free(fds);
2280
2281 return r;
2282 }
2283
2284 static const char* const manager_running_as_table[_MANAGER_RUNNING_AS_MAX] = {
2285 [MANAGER_INIT] = "init",
2286 [MANAGER_SYSTEM] = "system",
2287 [MANAGER_SESSION] = "session"
2288 };
2289
2290 DEFINE_STRING_TABLE_LOOKUP(manager_running_as, ManagerRunningAs);
Michael's branch of systemd.