1 /*-*- Mode: C; c-basic-offset: 8 -*-*/
8 #include <sys/signalfd.h>
20 static const char * const special_table[_SPECIAL_UNIT_MAX] = {
21 [SPECIAL_SYSLOG_SERVICE] = "syslog.service",
22 [SPECIAL_DBUS_SERVICE] = "messagebus.service",
23 [SPECIAL_LOGGER_SOCKET] = "systemd-logger.socket",
24 [SPECIAL_KBREQUEST_TARGET] = "kbrequest.target",
25 [SPECIAL_CTRL_ALT_DEL_TARGET] = "ctrl-alt-del.target"
28 static int manager_setup_signals(Manager *m) {
30 struct epoll_event ev;
34 assert_se(reset_all_signal_handlers() == 0);
36 assert_se(sigemptyset(&mask) == 0);
37 assert_se(sigaddset(&mask, SIGCHLD) == 0);
38 assert_se(sigaddset(&mask, SIGINT) == 0); /* Kernel sends us this on control-alt-del */
39 assert_se(sigaddset(&mask, SIGWINCH) == 0); /* Kernel sends us this on kbrequest (alt-arrowup) */
40 assert_se(sigaddset(&mask, SIGTERM) == 0);
41 assert_se(sigaddset(&mask, SIGHUP) == 0);
42 assert_se(sigaddset(&mask, SIGUSR1) == 0);
43 assert_se(sigaddset(&mask, SIGUSR2) == 0);
44 assert_se(sigaddset(&mask, SIGPIPE) == 0);
45 assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
47 m->signal_watch.type = WATCH_SIGNAL_FD;
48 if ((m->signal_watch.fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
53 ev.data.ptr = &m->signal_watch;
55 if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_watch.fd, &ev) < 0)
61 static int manager_load_special_units(Manager *m) {
67 /* Loads all 'special' units, so that we have easy access to them later */
69 for (c = 0; c < _SPECIAL_UNIT_MAX; c++)
70 if ((r = manager_load_unit(m, special_table[c], m->special_units+c)) < 0)
76 Manager* manager_new(void) {
79 if (!(m = new0(Manager, 1)))
82 m->signal_watch.fd = m->epoll_fd = -1;
84 if (!(m->units = hashmap_new(string_hash_func, string_compare_func)))
87 if (!(m->jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
90 if (!(m->transaction_jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
93 if (!(m->watch_pids = hashmap_new(trivial_hash_func, trivial_compare_func)))
96 if ((m->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0)
99 if (manager_setup_signals(m) < 0)
102 if (manager_load_special_units(m) < 0)
112 void manager_free(Manager *m) {
118 while ((j = hashmap_first(m->transaction_jobs)))
121 while ((u = hashmap_first(m->units)))
124 hashmap_free(m->units);
125 hashmap_free(m->jobs);
126 hashmap_free(m->transaction_jobs);
127 hashmap_free(m->watch_pids);
129 if (m->epoll_fd >= 0)
130 close_nointr(m->epoll_fd);
131 if (m->signal_watch.fd >= 0)
132 close_nointr(m->signal_watch.fd);
137 static void transaction_delete_job(Manager *m, Job *j) {
141 /* Deletes one job from the transaction */
143 manager_transaction_unlink_job(m, j);
149 static void transaction_delete_unit(Manager *m, Unit *u) {
152 /* Deletes all jobs associated with a certain unit from the
155 while ((j = hashmap_get(m->transaction_jobs, u)))
156 transaction_delete_job(m, j);
159 static void transaction_clean_dependencies(Manager *m) {
165 /* Drops all dependencies of all installed jobs */
167 HASHMAP_FOREACH(j, m->jobs, i) {
168 while (j->subject_list)
169 job_dependency_free(j->subject_list);
170 while (j->object_list)
171 job_dependency_free(j->object_list);
174 assert(!m->transaction_anchor);
177 static void transaction_abort(Manager *m) {
182 while ((j = hashmap_first(m->transaction_jobs)))
184 transaction_delete_job(m, j);
188 assert(hashmap_isempty(m->transaction_jobs));
190 transaction_clean_dependencies(m);
193 static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
198 /* A recursive sweep through the graph that marks all units
199 * that matter to the anchor job, i.e. are directly or
200 * indirectly a dependency of the anchor job via paths that
201 * are fully marked as mattering. */
206 l = m->transaction_anchor;
208 LIST_FOREACH(subject, l, l) {
210 /* This link does not matter */
214 /* This unit has already been marked */
215 if (l->object->generation == generation)
218 l->object->matters_to_anchor = true;
219 l->object->generation = generation;
221 transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
225 static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
226 JobDependency *l, *last;
230 assert(j->unit == other->unit);
231 assert(!j->installed);
233 /* Merges 'other' into 'j' and then deletes j. */
236 j->state = JOB_WAITING;
237 j->forced = j->forced || other->forced;
239 j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
241 /* Patch us in as new owner of the JobDependency objects */
243 LIST_FOREACH(subject, l, other->subject_list) {
244 assert(l->subject == other);
249 /* Merge both lists */
251 last->subject_next = j->subject_list;
253 j->subject_list->subject_prev = last;
254 j->subject_list = other->subject_list;
257 /* Patch us in as new owner of the JobDependency objects */
259 LIST_FOREACH(object, l, other->object_list) {
260 assert(l->object == other);
265 /* Merge both lists */
267 last->object_next = j->object_list;
269 j->object_list->object_prev = last;
270 j->object_list = other->object_list;
273 /* Kill the other job */
274 other->subject_list = NULL;
275 other->object_list = NULL;
276 transaction_delete_job(m, other);
279 static int delete_one_unmergeable_job(Manager *m, Job *j) {
284 /* Tries to delete one item in the linked list
285 * j->transaction_next->transaction_next->... that conflicts
286 * whith another one, in an attempt to make an inconsistent
287 * transaction work. */
289 /* We rely here on the fact that if a merged with b does not
290 * merge with c, either a or b merge with c neither */
291 LIST_FOREACH(transaction, j, j)
292 LIST_FOREACH(transaction, k, j->transaction_next) {
295 /* Is this one mergeable? Then skip it */
296 if (job_type_is_mergeable(j->type, k->type))
299 /* Ok, we found two that conflict, let's see if we can
300 * drop one of them */
301 if (!j->matters_to_anchor)
303 else if (!k->matters_to_anchor)
308 /* Ok, we can drop one, so let's do so. */
309 log_debug("Try to fix job merging by deleting job %s/%s", unit_id(d->unit), job_type_to_string(d->type));
310 transaction_delete_job(m, d);
317 static int transaction_merge_jobs(Manager *m) {
324 /* First step, check whether any of the jobs for one specific
325 * task conflict. If so, try to drop one of them. */
326 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
331 LIST_FOREACH(transaction, k, j->transaction_next) {
332 if ((r = job_type_merge(&t, k->type)) >= 0)
335 /* OK, we could not merge all jobs for this
336 * action. Let's see if we can get rid of one
339 if ((r = delete_one_unmergeable_job(m, j)) >= 0)
340 /* Ok, we managed to drop one, now
341 * let's ask our callers to call us
342 * again after garbage collecting */
345 /* We couldn't merge anything. Failure */
350 /* Second step, merge the jobs. */
351 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
355 /* Merge all transactions */
356 LIST_FOREACH(transaction, k, j->transaction_next)
357 assert_se(job_type_merge(&t, k->type) == 0);
359 /* If an active job is mergeable, merge it too */
360 if (j->unit->meta.job)
361 job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
363 while ((k = j->transaction_next)) {
365 transaction_merge_and_delete_job(m, k, j, t);
368 transaction_merge_and_delete_job(m, j, k, t);
371 assert(!j->transaction_next);
372 assert(!j->transaction_prev);
378 static bool unit_matters_to_anchor(Unit *u, Job *j) {
380 assert(!j->transaction_prev);
382 /* Checks whether at least one of the jobs for this unit
383 * matters to the anchor. */
385 LIST_FOREACH(transaction, j, j)
386 if (j->matters_to_anchor)
392 static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation) {
399 assert(!j->transaction_prev);
401 /* Does a recursive sweep through the ordering graph, looking
402 * for a cycle. If we find cycle we try to break it. */
404 /* Did we find a cycle? */
405 if (j->marker && j->generation == generation) {
408 /* So, we already have been here. We have a
409 * cycle. Let's try to break it. We go backwards in
410 * our path and try to find a suitable job to
411 * remove. We use the marker to find our way back,
412 * since smart how we are we stored our way back in
415 for (k = from; k; k = (k->generation == generation ? k->marker : NULL)) {
418 !unit_matters_to_anchor(k->unit, k)) {
419 /* Ok, we can drop this one, so let's
421 log_debug("Breaking order cycle by deleting job %s/%s", unit_id(k->unit), job_type_to_string(k->type));
422 transaction_delete_unit(m, k->unit);
426 /* Check if this in fact was the beginning of
435 /* Make the marker point to where we come from, so that we can
436 * find our way backwards if we want to break a cycle */
438 j->generation = generation;
440 /* We assume that the the dependencies are bidirectional, and
441 * hence can ignore UNIT_AFTER */
442 SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
445 /* Is there a job for this unit? */
446 if (!(o = hashmap_get(m->transaction_jobs, u)))
448 /* Ok, there is no job for this in the
449 * transaction, but maybe there is already one
451 if (!(o = u->meta.job))
454 if ((r = transaction_verify_order_one(m, o, j, generation)) < 0)
461 static int transaction_verify_order(Manager *m, unsigned *generation) {
469 /* Check if the ordering graph is cyclic. If it is, try to fix
470 * that up by dropping one of the jobs. */
472 HASHMAP_FOREACH(j, m->transaction_jobs, i)
473 if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0)
479 static void transaction_collect_garbage(Manager *m) {
484 /* Drop jobs that are not required by any other job */
492 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
496 log_debug("Garbage collecting job %s/%s", unit_id(j->unit), job_type_to_string(j->type));
497 transaction_delete_job(m, j);
505 static int transaction_is_destructive(Manager *m, JobMode mode) {
511 /* Checks whether applying this transaction means that
512 * existing jobs would be replaced */
514 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
517 assert(!j->transaction_prev);
518 assert(!j->transaction_next);
520 if (j->unit->meta.job &&
521 j->unit->meta.job != j &&
522 !job_type_is_superset(j->type, j->unit->meta.job->type))
529 static void transaction_minimize_impact(Manager *m) {
533 /* Drops all unnecessary jobs that reverse already active jobs
534 * or that stop a running service. */
542 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
543 LIST_FOREACH(transaction, j, j) {
545 /* If it matters, we shouldn't drop it */
546 if (j->matters_to_anchor)
549 /* Would this stop a running service?
550 * Would this change an existing job?
551 * If so, let's drop this entry */
552 if ((j->type != JOB_STOP || UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(j->unit))) &&
553 (!j->unit->meta.job || job_type_is_conflicting(j->type, j->unit->meta.job->state)))
556 /* Ok, let's get rid of this */
557 log_debug("Deleting %s/%s to minimize impact", unit_id(j->unit), job_type_to_string(j->type));
558 transaction_delete_job(m, j);
570 static int transaction_apply(Manager *m, JobMode mode) {
575 /* Moves the transaction jobs to the set of active jobs */
577 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
579 assert(!j->transaction_prev);
580 assert(!j->transaction_next);
585 if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
589 while ((j = hashmap_steal_first(m->transaction_jobs))) {
593 if (j->unit->meta.job)
594 job_free(j->unit->meta.job);
596 j->unit->meta.job = j;
599 /* We're fully installed. Now let's free data we don't
602 assert(!j->transaction_next);
603 assert(!j->transaction_prev);
608 /* As last step, kill all remaining job dependencies. */
609 transaction_clean_dependencies(m);
615 HASHMAP_FOREACH(j, m->transaction_jobs, i) {
619 hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
625 static int transaction_activate(Manager *m, JobMode mode) {
627 unsigned generation = 1;
631 /* This applies the changes recorded in transaction_jobs to
632 * the actual list of jobs, if possible. */
634 /* First step: figure out which jobs matter */
635 transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
637 /* Second step: Try not to stop any running services if
638 * we don't have to. Don't try to reverse running
639 * jobs if we don't have to. */
640 transaction_minimize_impact(m);
643 /* Third step: Let's remove unneeded jobs that might
645 transaction_collect_garbage(m);
647 /* Fourth step: verify order makes sense and correct
648 * cycles if necessary and possible */
649 if ((r = transaction_verify_order(m, &generation)) >= 0)
655 /* Let's see if the resulting transaction ordering
656 * graph is still cyclic... */
660 /* Fifth step: let's drop unmergeable entries if
661 * necessary and possible, merge entries we can
663 if ((r = transaction_merge_jobs(m)) >= 0)
669 /* Sixth step: an entry got dropped, let's garbage
670 * collect its dependencies. */
671 transaction_collect_garbage(m);
673 /* Let's see if the resulting transaction still has
674 * unmergeable entries ... */
677 /* Seventh step: check whether we can actually apply this */
678 if (mode == JOB_FAIL)
679 if ((r = transaction_is_destructive(m, mode)) < 0)
682 /* Eights step: apply changes */
683 if ((r = transaction_apply(m, mode)) < 0)
686 assert(hashmap_isempty(m->transaction_jobs));
687 assert(!m->transaction_anchor);
692 transaction_abort(m);
696 static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool force, bool *is_new) {
703 /* Looks for an axisting prospective job and returns that. If
704 * it doesn't exist it is created and added to the prospective
707 f = hashmap_get(m->transaction_jobs, unit);
709 LIST_FOREACH(transaction, j, f) {
710 assert(j->unit == unit);
712 if (j->type == type) {
719 if (unit->meta.job && unit->meta.job->type == type)
721 else if (!(j = job_new(m, type, unit)))
726 j->matters_to_anchor = false;
729 LIST_PREPEND(Job, transaction, f, j);
731 if ((r = hashmap_replace(m->transaction_jobs, unit, f)) < 0) {
742 void manager_transaction_unlink_job(Manager *m, Job *j) {
746 if (j->transaction_prev)
747 j->transaction_prev->transaction_next = j->transaction_next;
748 else if (j->transaction_next)
749 hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
751 hashmap_remove_value(m->transaction_jobs, j->unit, j);
753 if (j->transaction_next)
754 j->transaction_next->transaction_prev = j->transaction_prev;
756 j->transaction_prev = j->transaction_next = NULL;
758 while (j->subject_list)
759 job_dependency_free(j->subject_list);
761 while (j->object_list) {
762 Job *other = j->object_list->matters ? j->object_list->subject : NULL;
764 job_dependency_free(j->object_list);
767 log_debug("Deleting job %s/%s as dependency of job %s/%s",
768 unit_id(other->unit), job_type_to_string(other->type),
769 unit_id(j->unit), job_type_to_string(j->type));
770 transaction_delete_job(m, other);
775 static int transaction_add_job_and_dependencies(Manager *m, JobType type, Unit *unit, Job *by, bool matters, bool force, Job **_ret) {
783 assert(type < _JOB_TYPE_MAX);
786 if (unit->meta.load_state != UNIT_LOADED)
789 if (!unit_job_is_applicable(unit, type))
792 /* First add the job. */
793 if (!(ret = transaction_add_one_job(m, type, unit, force, &is_new)))
796 /* Then, add a link to the job. */
797 if (!job_dependency_new(by, ret, matters))
801 /* Finally, recursively add in all dependencies. */
802 if (type == JOB_START || type == JOB_RELOAD_OR_START) {
803 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
804 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
806 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUIRES], i)
807 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
809 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
810 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, force, NULL)) < 0 && r != -EBADR)
812 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
813 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
815 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUISITE], i)
816 if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
818 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
819 if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
822 } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
824 SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
825 if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
829 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
838 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool force, Job **_ret) {
843 assert(type < _JOB_TYPE_MAX);
845 assert(mode < _JOB_MODE_MAX);
847 if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, force, &ret))) {
848 transaction_abort(m);
852 if ((r = transaction_activate(m, mode)) < 0)
861 Job *manager_get_job(Manager *m, uint32_t id) {
864 return hashmap_get(m->jobs, UINT32_TO_PTR(id));
867 Unit *manager_get_unit(Manager *m, const char *name) {
871 return hashmap_get(m->units, name);
874 static void dispatch_load_queue(Manager *m) {
879 /* Make sure we are not run recursively */
880 if (m->dispatching_load_queue)
883 m->dispatching_load_queue = true;
885 /* Dispatches the load queue. Takes a unit from the queue and
886 * tries to load its data until the queue is empty */
888 while ((meta = m->load_queue)) {
889 assert(meta->in_load_queue);
891 unit_load(UNIT(meta));
894 m->dispatching_load_queue = false;
897 int manager_load_unit(Manager *m, const char *path, Unit **_ret) {
906 /* This will load the service information files, but not actually
907 * start any services or anything. */
909 name = file_name_from_path(path);
911 if ((ret = manager_get_unit(m, name))) {
916 if (!(ret = unit_new(m)))
920 if (!(ret->meta.load_path = strdup(path))) {
926 if ((r = unit_add_name(ret, name)) < 0) {
931 unit_add_to_load_queue(ret);
932 dispatch_load_queue(m);
938 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
945 HASHMAP_FOREACH(j, s->jobs, i)
946 job_dump(j, f, prefix);
949 void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
957 HASHMAP_FOREACH_KEY(u, t, s->units, i)
959 unit_dump(u, f, prefix);
962 void manager_clear_jobs(Manager *m) {
967 transaction_abort(m);
969 while ((j = hashmap_first(m->jobs)))
973 void manager_dispatch_run_queue(Manager *m) {
976 if (m->dispatching_run_queue)
979 m->dispatching_run_queue = true;
981 while ((j = m->run_queue)) {
982 assert(j->installed);
983 assert(j->in_run_queue);
985 job_run_and_invalidate(j);
988 m->dispatching_run_queue = false;
991 static int manager_dispatch_sigchld(Manager *m) {
994 log_debug("dispatching SIGCHLD");
1001 if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG) < 0) {
1003 if (errno == ECHILD)
1012 if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
1015 log_debug("child %llu died (code=%s, status=%i)", (long long unsigned) si.si_pid, sigchld_code(si.si_code), si.si_status);
1017 if (!(u = hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid))))
1020 UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
1026 static int manager_process_signal_fd(Manager *m, bool *quit) {
1028 struct signalfd_siginfo sfsi;
1029 bool sigchld = false;
1034 if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
1039 if (errno == EAGAIN)
1045 switch (sfsi.ssi_signo) {
1057 log_info("Got unhandled signal <%s>.", strsignal(sfsi.ssi_signo));
1062 return manager_dispatch_sigchld(m);
1067 static int process_event(Manager *m, struct epoll_event *ev, bool *quit) {
1074 assert(w = ev->data.ptr);
1078 case WATCH_SIGNAL_FD:
1080 /* An incoming signal? */
1081 if (ev->events != POLLIN)
1084 if ((r = manager_process_signal_fd(m, quit)) < 0)
1091 /* Some fd event, to be dispatched to the units */
1092 UNIT_VTABLE(w->unit)->fd_event(w->unit, w->fd, ev->events, w);
1099 /* Some timer event, to be dispatched to the units */
1100 if ((k = read(ev->data.fd, &v, sizeof(v))) != sizeof(v)) {
1102 if (k < 0 && (errno == EINTR || errno == EAGAIN))
1105 return k < 0 ? -errno : -EIO;
1108 UNIT_VTABLE(w->unit)->timer_event(w->unit, v, w);
1113 assert_not_reached("Unknown epoll event type.");
1119 int manager_loop(Manager *m) {
1126 struct epoll_event event;
1129 manager_dispatch_run_queue(m);
1131 if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) {
1133 if (errno == -EINTR)
1141 if ((r = process_event(m, &event, &quit)) < 0)