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