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