/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include #include "alloc-util.h" #include "bus-common-errors.h" #include "bus-error.h" #include "dbus-unit.h" #include "strv.h" #include "terminal-util.h" #include "transaction.h" static void transaction_unlink_job(Transaction *tr, Job *j, bool delete_dependencies); static void transaction_delete_job(Transaction *tr, Job *j, bool delete_dependencies) { assert(tr); assert(j); /* Deletes one job from the transaction */ transaction_unlink_job(tr, j, delete_dependencies); job_free(j); } static void transaction_delete_unit(Transaction *tr, Unit *u) { Job *j; /* Deletes all jobs associated with a certain unit from the * transaction */ while ((j = hashmap_get(tr->jobs, u))) transaction_delete_job(tr, j, true); } static void transaction_abort(Transaction *tr) { Job *j; assert(tr); while ((j = hashmap_first(tr->jobs))) transaction_delete_job(tr, j, false); assert(hashmap_isempty(tr->jobs)); } static void transaction_find_jobs_that_matter_to_anchor(Job *j, unsigned generation) { assert(j); /* A recursive sweep through the graph that marks all units * that matter to the anchor job, i.e. are directly or * indirectly a dependency of the anchor job via paths that * are fully marked as mattering. */ j->matters_to_anchor = true; j->generation = generation; LIST_FOREACH(subject, l, j->subject_list) { /* This link does not matter */ if (!l->matters) continue; /* This unit has already been marked */ if (l->object->generation == generation) continue; transaction_find_jobs_that_matter_to_anchor(l->object, generation); } } static void transaction_merge_and_delete_job(Transaction *tr, Job *j, Job *other, JobType t) { JobDependency *last; assert(j); assert(other); assert(j->unit == other->unit); assert(!j->installed); /* Merges 'other' into 'j' and then deletes 'other'. */ j->type = t; j->state = JOB_WAITING; j->irreversible = j->irreversible || other->irreversible; j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor; /* Patch us in as new owner of the JobDependency objects */ last = NULL; LIST_FOREACH(subject, l, other->subject_list) { assert(l->subject == other); l->subject = j; last = l; } /* Merge both lists */ if (last) { last->subject_next = j->subject_list; if (j->subject_list) j->subject_list->subject_prev = last; j->subject_list = other->subject_list; } /* Patch us in as new owner of the JobDependency objects */ last = NULL; LIST_FOREACH(object, l, other->object_list) { assert(l->object == other); l->object = j; last = l; } /* Merge both lists */ if (last) { last->object_next = j->object_list; if (j->object_list) j->object_list->object_prev = last; j->object_list = other->object_list; } /* Kill the other job */ other->subject_list = NULL; other->object_list = NULL; transaction_delete_job(tr, other, true); } static bool job_is_conflicted_by(Job *j) { assert(j); /* Returns true if this job is pulled in by a least one * ConflictedBy dependency. */ LIST_FOREACH(object, l, j->object_list) if (l->conflicts) return true; return false; } static int delete_one_unmergeable_job(Transaction *tr, Job *job) { assert(job); /* Tries to delete one item in the linked list * j->transaction_next->transaction_next->... that conflicts * with another one, in an attempt to make an inconsistent * transaction work. */ /* We rely here on the fact that if a merged with b does not * merge with c, either a or b merge with c neither */ LIST_FOREACH(transaction, j, job) LIST_FOREACH(transaction, k, j->transaction_next) { Job *d; /* Is this one mergeable? Then skip it */ if (job_type_is_mergeable(j->type, k->type)) continue; /* Ok, we found two that conflict, let's see if we can * drop one of them */ if (!j->matters_to_anchor && !k->matters_to_anchor) { /* Both jobs don't matter, so let's * find the one that is smarter to * remove. Let's think positive and * rather remove stops then starts -- * except if something is being * stopped because it is conflicted by * another unit in which case we * rather remove the start. */ log_unit_debug(j->unit, "Looking at job %s/%s conflicted_by=%s", j->unit->id, job_type_to_string(j->type), yes_no(j->type == JOB_STOP && job_is_conflicted_by(j))); log_unit_debug(k->unit, "Looking at job %s/%s conflicted_by=%s", k->unit->id, job_type_to_string(k->type), yes_no(k->type == JOB_STOP && job_is_conflicted_by(k))); if (j->type == JOB_STOP) { if (job_is_conflicted_by(j)) d = k; else d = j; } else if (k->type == JOB_STOP) { if (job_is_conflicted_by(k)) d = j; else d = k; } else d = j; } else if (!j->matters_to_anchor) d = j; else if (!k->matters_to_anchor) d = k; else return -ENOEXEC; /* Ok, we can drop one, so let's do so. */ log_unit_debug(d->unit, "Fixing conflicting jobs %s/%s,%s/%s by deleting job %s/%s", j->unit->id, job_type_to_string(j->type), k->unit->id, job_type_to_string(k->type), d->unit->id, job_type_to_string(d->type)); transaction_delete_job(tr, d, true); return 0; } return -EINVAL; } static int transaction_merge_jobs(Transaction *tr, sd_bus_error *e) { Job *j; int r; assert(tr); /* First step, check whether any of the jobs for one specific * task conflict. If so, try to drop one of them. */ HASHMAP_FOREACH(j, tr->jobs) { JobType t; t = j->type; LIST_FOREACH(transaction, k, j->transaction_next) { if (job_type_merge_and_collapse(&t, k->type, j->unit) >= 0) continue; /* OK, we could not merge all jobs for this * action. Let's see if we can get rid of one * of them */ r = delete_one_unmergeable_job(tr, j); if (r >= 0) /* Ok, we managed to drop one, now * let's ask our callers to call us * again after garbage collecting */ return -EAGAIN; /* We couldn't merge anything. Failure */ return sd_bus_error_setf(e, BUS_ERROR_TRANSACTION_JOBS_CONFLICTING, "Transaction contains conflicting jobs '%s' and '%s' for %s. " "Probably contradicting requirement dependencies configured.", job_type_to_string(t), job_type_to_string(k->type), k->unit->id); } } /* Second step, merge the jobs. */ HASHMAP_FOREACH(j, tr->jobs) { JobType t = j->type; /* Merge all transaction jobs for j->unit */ LIST_FOREACH(transaction, k, j->transaction_next) assert_se(job_type_merge_and_collapse(&t, k->type, j->unit) == 0); Job *k; while ((k = j->transaction_next)) { if (tr->anchor_job == k) { transaction_merge_and_delete_job(tr, k, j, t); j = k; } else transaction_merge_and_delete_job(tr, j, k, t); } assert(!j->transaction_next); assert(!j->transaction_prev); } return 0; } static void transaction_drop_redundant(Transaction *tr) { bool again; /* Goes through the transaction and removes all jobs of the units whose jobs are all noops. If not * all of a unit's jobs are redundant, they are kept. */ assert(tr); do { Job *j; again = false; HASHMAP_FOREACH(j, tr->jobs) { bool keep = false; LIST_FOREACH(transaction, k, j) if (tr->anchor_job == k || !job_type_is_redundant(k->type, unit_active_state(k->unit)) || (k->unit->job && job_type_is_conflicting(k->type, k->unit->job->type))) { keep = true; break; } if (!keep) { log_trace("Found redundant job %s/%s, dropping from transaction.", j->unit->id, job_type_to_string(j->type)); transaction_delete_job(tr, j, false); again = true; break; } } } while (again); } static bool job_matters_to_anchor(Job *job) { assert(job); assert(!job->transaction_prev); /* Checks whether at least one of the jobs for this transaction matters to the anchor. */ LIST_FOREACH(transaction, j, job) if (j->matters_to_anchor) return true; return false; } static char* merge_unit_ids(const char* unit_log_field, char * const* pairs) { _cleanup_free_ char *ans = NULL; size_t size = 0; assert(unit_log_field); STRV_FOREACH_PAIR(unit_id, job_type, pairs) { size_t next; if (size > 0) ans[size - 1] = '\n'; next = strlen(unit_log_field) + strlen(*unit_id); if (!GREEDY_REALLOC(ans, size + next + 1)) return NULL; sprintf(ans + size, "%s%s", unit_log_field, *unit_id); size += next + 1; } if (!ans) return strdup(""); return TAKE_PTR(ans); } static int transaction_verify_order_one(Transaction *tr, Job *j, Job *from, unsigned generation, sd_bus_error *e) { static const UnitDependencyAtom directions[] = { UNIT_ATOM_BEFORE, UNIT_ATOM_AFTER, }; int r; assert(tr); assert(j); assert(!j->transaction_prev); /* Does a recursive sweep through the ordering graph, looking for a cycle. If we find a cycle we try * to break it. */ /* Have we seen this before? */ if (j->generation == generation) { Job *k, *delete = NULL; _cleanup_free_ char **array = NULL, *unit_ids = NULL; /* If the marker is NULL we have been here already and decided the job was loop-free from * here. Hence shortcut things and return right-away. */ if (!j->marker) return 0; /* So, the marker is not NULL and we already have been here. We have a cycle. Let's try to * break it. We go backwards in our path and try to find a suitable job to remove. We use the * marker to find our way back, since smart how we are we stored our way back in there. */ for (k = from; k; k = ((k->generation == generation && k->marker != k) ? k->marker : NULL)) { /* For logging below */ if (strv_push_pair(&array, k->unit->id, (char*) job_type_to_string(k->type)) < 0) log_oom(); if (!delete && hashmap_contains(tr->jobs, k->unit) && !job_matters_to_anchor(k)) /* Ok, we can drop this one, so let's do so. */ delete = k; /* Check if this in fact was the beginning of the cycle */ if (k == j) break; } unit_ids = merge_unit_ids(j->manager->unit_log_field, array); /* ignore error */ STRV_FOREACH_PAIR(unit_id, job_type, array) /* logging for j not k here to provide a consistent narrative */ log_struct(LOG_WARNING, LOG_UNIT_MESSAGE(j->unit, "Found %s on %s/%s", unit_id == array ? "ordering cycle" : "dependency", *unit_id, *job_type), "%s", strna(unit_ids)); if (delete) { const char *status; /* logging for j not k here to provide a consistent narrative */ log_struct(LOG_ERR, LOG_UNIT_MESSAGE(j->unit, "Job %s/%s deleted to break ordering cycle starting with %s/%s", delete->unit->id, job_type_to_string(delete->type), j->unit->id, job_type_to_string(j->type)), "%s", strna(unit_ids)); if (log_get_show_color()) status = ANSI_HIGHLIGHT_RED " SKIP " ANSI_NORMAL; else status = " SKIP "; unit_status_printf(delete->unit, STATUS_TYPE_NOTICE, status, "Ordering cycle found, skipping %s", unit_status_string(delete->unit, NULL)); transaction_delete_unit(tr, delete->unit); return -EAGAIN; } log_struct(LOG_ERR, LOG_UNIT_MESSAGE(j->unit, "Unable to break cycle starting with %s/%s", j->unit->id, job_type_to_string(j->type)), "%s", strna(unit_ids)); return sd_bus_error_setf(e, BUS_ERROR_TRANSACTION_ORDER_IS_CYCLIC, "Transaction order is cyclic. See system logs for details."); } /* Make the marker point to where we come from, so that we can * find our way backwards if we want to break a cycle. We use * a special marker for the beginning: we point to * ourselves. */ j->marker = from ?: j; j->generation = generation; /* Actual ordering of jobs depends on the unit ordering dependency and job types. We need to traverse * the graph over 'before' edges in the actual job execution order. We traverse over both unit * ordering dependencies and we test with job_compare() whether it is the 'before' edge in the job * execution ordering. */ for (size_t d = 0; d < ELEMENTSOF(directions); d++) { Unit *u; UNIT_FOREACH_DEPENDENCY(u, j->unit, directions[d]) { Job *o; /* Is there a job for this unit? */ o = hashmap_get(tr->jobs, u); if (!o) { /* Ok, there is no job for this in the transaction, but maybe there is * already one running? */ o = u->job; if (!o) continue; } /* Cut traversing if the job j is not really *before* o. */ if (job_compare(j, o, directions[d]) >= 0) continue; r = transaction_verify_order_one(tr, o, j, generation, e); if (r < 0) return r; } } /* Ok, let's backtrack, and remember that this entry is not on * our path anymore. */ j->marker = NULL; return 0; } static int transaction_verify_order(Transaction *tr, unsigned *generation, sd_bus_error *e) { Job *j; int r; unsigned g; assert(tr); assert(generation); /* Check if the ordering graph is cyclic. If it is, try to fix * that up by dropping one of the jobs. */ g = (*generation)++; HASHMAP_FOREACH(j, tr->jobs) { r = transaction_verify_order_one(tr, j, NULL, g, e); if (r < 0) return r; } return 0; } static void transaction_collect_garbage(Transaction *tr) { bool again; assert(tr); /* Drop jobs that are not required by any other job */ do { Job *j; again = false; HASHMAP_FOREACH(j, tr->jobs) { if (tr->anchor_job == j) continue; if (!j->object_list) { log_trace("Garbage collecting job %s/%s", j->unit->id, job_type_to_string(j->type)); transaction_delete_job(tr, j, true); again = true; break; } log_trace("Keeping job %s/%s because of %s/%s", j->unit->id, job_type_to_string(j->type), j->object_list->subject ? j->object_list->subject->unit->id : "root", j->object_list->subject ? job_type_to_string(j->object_list->subject->type) : "root"); } } while (again); } static int transaction_is_destructive(Transaction *tr, JobMode mode, sd_bus_error *e) { Job *j; assert(tr); /* Checks whether applying this transaction means that * existing jobs would be replaced */ HASHMAP_FOREACH(j, tr->jobs) { /* Assume merged */ assert(!j->transaction_prev); assert(!j->transaction_next); if (j->unit->job && (mode == JOB_FAIL || j->unit->job->irreversible) && job_type_is_conflicting(j->unit->job->type, j->type)) return sd_bus_error_setf(e, BUS_ERROR_TRANSACTION_IS_DESTRUCTIVE, "Transaction for %s/%s is destructive (%s has '%s' job queued, but '%s' is included in transaction).", tr->anchor_job->unit->id, job_type_to_string(tr->anchor_job->type), j->unit->id, job_type_to_string(j->unit->job->type), job_type_to_string(j->type)); } return 0; } static void transaction_minimize_impact(Transaction *tr) { Job *head; assert(tr); /* Drops all unnecessary jobs that reverse already active jobs * or that stop a running service. */ rescan: HASHMAP_FOREACH(head, tr->jobs) { LIST_FOREACH(transaction, j, head) { bool stops_running_service, changes_existing_job; /* If it matters, we shouldn't drop it */ if (j->matters_to_anchor) continue; /* Would this stop a running service? * Would this change an existing job? * If so, let's drop this entry */ stops_running_service = j->type == JOB_STOP && UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(j->unit)); changes_existing_job = j->unit->job && job_type_is_conflicting(j->type, j->unit->job->type); if (!stops_running_service && !changes_existing_job) continue; if (stops_running_service) log_unit_debug(j->unit, "%s/%s would stop a running service.", j->unit->id, job_type_to_string(j->type)); if (changes_existing_job) log_unit_debug(j->unit, "%s/%s would change existing job.", j->unit->id, job_type_to_string(j->type)); /* Ok, let's get rid of this */ log_unit_debug(j->unit, "Deleting %s/%s to minimize impact.", j->unit->id, job_type_to_string(j->type)); transaction_delete_job(tr, j, true); goto rescan; } } } static int transaction_apply( Transaction *tr, Manager *m, JobMode mode, Set *affected_jobs) { Job *j; int r; /* Moves the transaction jobs to the set of active jobs */ if (IN_SET(mode, JOB_ISOLATE, JOB_FLUSH)) { /* When isolating first kill all installed jobs which * aren't part of the new transaction */ HASHMAP_FOREACH(j, m->jobs) { assert(j->installed); if (j->unit->ignore_on_isolate) continue; if (hashmap_contains(tr->jobs, j->unit)) continue; /* Not invalidating recursively. Avoids triggering * OnFailure= actions of dependent jobs. Also avoids * invalidating our iterator. */ job_finish_and_invalidate(j, JOB_CANCELED, false, false); } } HASHMAP_FOREACH(j, tr->jobs) { /* Assume merged */ assert(!j->transaction_prev); assert(!j->transaction_next); r = hashmap_ensure_put(&m->jobs, NULL, UINT32_TO_PTR(j->id), j); if (r < 0) goto rollback; } while ((j = hashmap_steal_first(tr->jobs))) { Job *installed_job; /* Clean the job dependencies */ transaction_unlink_job(tr, j, false); /* When RestartMode=direct is used, the service being restarted don't enter the inactive/failed * state, i.e. unit_process_job -> job_finish_and_invalidate is never called, and the previous * job might still be running (especially for Type=oneshot services). We need to refuse * late merge and re-enqueue the anchor job. */ installed_job = job_install(j, /* refuse_late_merge = */ mode == JOB_RESTART_DEPENDENCIES && j == tr->anchor_job); if (installed_job != j) { /* j has been merged into a previously installed job */ if (tr->anchor_job == j) tr->anchor_job = installed_job; hashmap_remove_value(m->jobs, UINT32_TO_PTR(j->id), j); free_and_replace_full(j, installed_job, job_free); } job_add_to_run_queue(j); job_add_to_dbus_queue(j); job_start_timer(j, false); job_shutdown_magic(j); /* When 'affected' is specified, let's track all in it all jobs that were touched because of * this transaction. */ if (affected_jobs) (void) set_put(affected_jobs, j); } return 0; rollback: HASHMAP_FOREACH(j, tr->jobs) hashmap_remove_value(m->jobs, UINT32_TO_PTR(j->id), j); return r; } int transaction_activate( Transaction *tr, Manager *m, JobMode mode, Set *affected_jobs, sd_bus_error *e) { Job *j; int r; unsigned generation = 1; assert(tr); /* This applies the changes recorded in tr->jobs to * the actual list of jobs, if possible. */ /* Reset the generation counter of all installed jobs. The detection of cycles * looks at installed jobs. If they had a non-zero generation from some previous * walk of the graph, the algorithm would break. */ HASHMAP_FOREACH(j, m->jobs) j->generation = 0; /* First step: figure out which jobs matter */ transaction_find_jobs_that_matter_to_anchor(tr->anchor_job, generation++); /* Second step: Try not to stop any running services if * we don't have to. Don't try to reverse running * jobs if we don't have to. */ if (mode == JOB_FAIL) transaction_minimize_impact(tr); /* Third step: Drop redundant jobs */ transaction_drop_redundant(tr); for (;;) { /* Fourth step: Let's remove unneeded jobs that might * be lurking. */ if (mode != JOB_ISOLATE) transaction_collect_garbage(tr); /* Fifth step: verify order makes sense and correct * cycles if necessary and possible */ r = transaction_verify_order(tr, &generation, e); if (r >= 0) break; if (r != -EAGAIN) return log_warning_errno(r, "Requested transaction contains an unfixable cyclic ordering dependency: %s", bus_error_message(e, r)); /* Let's see if the resulting transaction ordering * graph is still cyclic... */ } for (;;) { /* Sixth step: let's drop unmergeable entries if * necessary and possible, merge entries we can * merge */ r = transaction_merge_jobs(tr, e); if (r >= 0) break; if (r != -EAGAIN) return log_warning_errno(r, "Requested transaction contains unmergeable jobs: %s", bus_error_message(e, r)); /* Seventh step: an entry got dropped, let's garbage * collect its dependencies. */ if (mode != JOB_ISOLATE) transaction_collect_garbage(tr); /* Let's see if the resulting transaction still has * unmergeable entries ... */ } /* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */ transaction_drop_redundant(tr); /* Ninth step: check whether we can actually apply this */ r = transaction_is_destructive(tr, mode, e); if (r < 0) return log_notice_errno(r, "Requested transaction contradicts existing jobs: %s", bus_error_message(e, r)); /* Tenth step: apply changes */ r = transaction_apply(tr, m, mode, affected_jobs); if (r < 0) return log_warning_errno(r, "Failed to apply transaction: %m"); assert(hashmap_isempty(tr->jobs)); /* Are there any jobs now? Then make sure we have the idle pipe around. We don't really care too much * whether this works or not, as the idle pipe is a feature for cosmetics, not actually useful for * anything beyond that. */ if (!hashmap_isempty(m->jobs)) (void) manager_allocate_idle_pipe(m); return 0; } static Job* transaction_add_one_job(Transaction *tr, JobType type, Unit *unit, bool *is_new) { Job *j, *f; assert(tr); assert(unit); /* Looks for an existing prospective job and returns that. If * it doesn't exist it is created and added to the prospective * jobs list. */ f = hashmap_get(tr->jobs, unit); LIST_FOREACH(transaction, i, f) { assert(i->unit == unit); if (i->type == type) { if (is_new) *is_new = false; return i; } } j = job_new(unit, type); if (!j) return NULL; j->generation = 0; j->marker = NULL; j->matters_to_anchor = false; j->irreversible = tr->irreversible; LIST_PREPEND(transaction, f, j); if (hashmap_replace(tr->jobs, unit, f) < 0) { LIST_REMOVE(transaction, f, j); job_free(j); return NULL; } if (is_new) *is_new = true; log_trace("Added job %s/%s to transaction.", unit->id, job_type_to_string(type)); return j; } static void transaction_unlink_job(Transaction *tr, Job *j, bool delete_dependencies) { assert(tr); assert(j); if (j->transaction_prev) j->transaction_prev->transaction_next = j->transaction_next; else if (j->transaction_next) hashmap_replace(tr->jobs, j->unit, j->transaction_next); else hashmap_remove_value(tr->jobs, j->unit, j); if (j->transaction_next) j->transaction_next->transaction_prev = j->transaction_prev; j->transaction_prev = j->transaction_next = NULL; while (j->subject_list) job_dependency_free(j->subject_list); while (j->object_list) { Job *other = j->object_list->matters ? j->object_list->subject : NULL; job_dependency_free(j->object_list); if (other && delete_dependencies) { log_unit_debug(other->unit, "Deleting job %s/%s as dependency of job %s/%s", other->unit->id, job_type_to_string(other->type), j->unit->id, job_type_to_string(j->type)); transaction_delete_job(tr, other, delete_dependencies); } } } void transaction_add_propagate_reload_jobs( Transaction *tr, Unit *unit, Job *by, TransactionAddFlags flags) { JobType nt; Unit *dep; int r; assert(tr); assert(unit); UNIT_FOREACH_DEPENDENCY(dep, unit, UNIT_ATOM_PROPAGATES_RELOAD_TO) { _cleanup_(sd_bus_error_free) sd_bus_error e = SD_BUS_ERROR_NULL; nt = job_type_collapse(JOB_TRY_RELOAD, dep); if (nt == JOB_NOP) continue; r = transaction_add_job_and_dependencies(tr, nt, dep, by, flags, &e); if (r < 0) log_unit_warning(dep, "Cannot add dependency reload job, ignoring: %s", bus_error_message(&e, r)); } } static JobType job_type_propagate_stop_graceful(Job *j) { JobType type; if (!j) return JOB_STOP; type = JOB_STOP; LIST_FOREACH(transaction, i, j) switch (i->type) { case JOB_STOP: case JOB_RESTART: /* Nothing to worry about, an appropriate job is in-place */ return JOB_NOP; case JOB_START: /* This unit is pulled in by other dependency types in this transaction. We will run * into job type conflict if we enqueue a stop job, so let's enqueue a restart job * instead. */ type = JOB_RESTART; break; default: /* We don't care about others */ ; } return type; } int transaction_add_job_and_dependencies( Transaction *tr, JobType type, Unit *unit, Job *by, TransactionAddFlags flags, sd_bus_error *e) { bool is_new; Job *ret; int r; assert(tr); assert(type < _JOB_TYPE_MAX); assert(type < _JOB_TYPE_MAX_IN_TRANSACTION); assert(unit); /* Before adding jobs for this unit, let's ensure that its state has been loaded This matters when * jobs are spawned as part of coldplugging itself (see e. g. path_coldplug()). This way, we * "recursively" coldplug units, ensuring that we do not look at state of not-yet-coldplugged * units. */ if (MANAGER_IS_RELOADING(unit->manager)) unit_coldplug(unit); if (by) log_trace("Pulling in %s/%s from %s/%s", unit->id, job_type_to_string(type), by->unit->id, job_type_to_string(by->type)); /* Safety check that the unit is a valid state, i.e. not in UNIT_STUB or UNIT_MERGED which should only be set * temporarily. */ if (!UNIT_IS_LOAD_COMPLETE(unit->load_state)) return sd_bus_error_setf(e, BUS_ERROR_LOAD_FAILED, "Unit %s is not loaded properly.", unit->id); if (type != JOB_STOP) { r = bus_unit_validate_load_state(unit, e); /* The time-based cache allows to start new units without daemon-reload, but if they are * already referenced (because of dependencies or ordering) then we have to force a load of * the fragment. As an optimization, check first if anything in the usual paths was modified * since the last time the cache was loaded. Also check if the last time an attempt to load * the unit was made was before the most recent cache refresh, so that we know we need to try * again — even if the cache is current, it might have been updated in a different context * before we had a chance to retry loading this particular unit. * * Given building up the transaction is a synchronous operation, attempt * to load the unit immediately. */ if (r < 0 && manager_unit_cache_should_retry_load(unit)) { sd_bus_error_free(e); unit->load_state = UNIT_STUB; r = unit_load(unit); if (r < 0 || unit->load_state == UNIT_STUB) unit->load_state = UNIT_NOT_FOUND; r = bus_unit_validate_load_state(unit, e); } if (r < 0) return r; } if (!unit_job_is_applicable(unit, type)) return sd_bus_error_setf(e, BUS_ERROR_JOB_TYPE_NOT_APPLICABLE, "Job type %s is not applicable for unit %s.", job_type_to_string(type), unit->id); /* First add the job. */ ret = transaction_add_one_job(tr, type, unit, &is_new); if (!ret) return -ENOMEM; if (FLAGS_SET(flags, TRANSACTION_IGNORE_ORDER)) ret->ignore_order = true; /* Then, add a link to the job. */ if (by) { if (!job_dependency_new(by, ret, FLAGS_SET(flags, TRANSACTION_MATTERS), FLAGS_SET(flags, TRANSACTION_CONFLICTS))) return -ENOMEM; } else { /* If the job has no parent job, it is the anchor job. */ assert(!tr->anchor_job); tr->anchor_job = ret; } if (!is_new || FLAGS_SET(flags, TRANSACTION_IGNORE_REQUIREMENTS) || type == JOB_NOP) return 0; _cleanup_set_free_ Set *following = NULL; Unit *dep; /* If we are following some other unit, make sure we add all dependencies of everybody following. */ if (unit_following_set(ret->unit, &following) > 0) SET_FOREACH(dep, following) { r = transaction_add_job_and_dependencies(tr, type, dep, ret, flags & TRANSACTION_IGNORE_ORDER, e); if (r < 0) { log_unit_full_errno(dep, r == -ERFKILL ? LOG_INFO : LOG_WARNING, r, "Cannot add dependency job, ignoring: %s", bus_error_message(e, r)); sd_bus_error_free(e); } } /* Finally, recursively add in all dependencies. */ if (IN_SET(type, JOB_START, JOB_RESTART)) { UNIT_FOREACH_DEPENDENCY(dep, ret->unit, UNIT_ATOM_PULL_IN_START) { r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, TRANSACTION_MATTERS | (flags & TRANSACTION_IGNORE_ORDER), e); if (r < 0) { if (r != -EBADR) /* job type not applicable */ goto fail; sd_bus_error_free(e); } } UNIT_FOREACH_DEPENDENCY(dep, ret->unit, UNIT_ATOM_PULL_IN_START_IGNORED) { r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, flags & TRANSACTION_IGNORE_ORDER, e); if (r < 0) { /* unit masked, job type not applicable and unit not found are not considered * as errors. */ log_unit_full_errno(dep, IN_SET(r, -ERFKILL, -EBADR, -ENOENT) ? LOG_DEBUG : LOG_WARNING, r, "Cannot add dependency job, ignoring: %s", bus_error_message(e, r)); sd_bus_error_free(e); } } UNIT_FOREACH_DEPENDENCY(dep, ret->unit, UNIT_ATOM_PULL_IN_VERIFY) { r = transaction_add_job_and_dependencies(tr, JOB_VERIFY_ACTIVE, dep, ret, TRANSACTION_MATTERS | (flags & TRANSACTION_IGNORE_ORDER), e); if (r < 0) { if (r != -EBADR) /* job type not applicable */ goto fail; sd_bus_error_free(e); } } UNIT_FOREACH_DEPENDENCY(dep, ret->unit, UNIT_ATOM_PULL_IN_STOP) { r = transaction_add_job_and_dependencies(tr, JOB_STOP, dep, ret, TRANSACTION_MATTERS | TRANSACTION_CONFLICTS | (flags & TRANSACTION_IGNORE_ORDER), e); if (r < 0) { if (r != -EBADR) /* job type not applicable */ goto fail; sd_bus_error_free(e); } } UNIT_FOREACH_DEPENDENCY(dep, ret->unit, UNIT_ATOM_PULL_IN_STOP_IGNORED) { r = transaction_add_job_and_dependencies(tr, JOB_STOP, dep, ret, flags & TRANSACTION_IGNORE_ORDER, e); if (r < 0) { log_unit_warning(dep, "Cannot add dependency job, ignoring: %s", bus_error_message(e, r)); sd_bus_error_free(e); } } } if (IN_SET(type, JOB_RESTART, JOB_STOP) || (type == JOB_START && FLAGS_SET(flags, TRANSACTION_PROPAGATE_START_AS_RESTART))) { bool is_stop = type == JOB_STOP; UNIT_FOREACH_DEPENDENCY(dep, ret->unit, is_stop ? UNIT_ATOM_PROPAGATE_STOP : UNIT_ATOM_PROPAGATE_RESTART) { /* We propagate RESTART only as TRY_RESTART, in order not to start dependencies that * are not around. */ JobType nt; nt = job_type_collapse(is_stop ? JOB_STOP : JOB_TRY_RESTART, dep); if (nt == JOB_NOP) continue; r = transaction_add_job_and_dependencies(tr, nt, dep, ret, TRANSACTION_MATTERS | (flags & TRANSACTION_IGNORE_ORDER), e); if (r < 0) { if (r != -EBADR) /* job type not applicable */ return r; sd_bus_error_free(e); } } /* Process UNIT_ATOM_PROPAGATE_STOP_GRACEFUL (PropagatesStopTo=) units. We need to wait until * all other dependencies are processed, i.e. we're the anchor job or already in the recursion * that handles it. */ if (!by || FLAGS_SET(flags, TRANSACTION_PROCESS_PROPAGATE_STOP_GRACEFUL)) UNIT_FOREACH_DEPENDENCY(dep, ret->unit, UNIT_ATOM_PROPAGATE_STOP_GRACEFUL) { JobType nt; Job *j; j = hashmap_get(tr->jobs, dep); nt = job_type_propagate_stop_graceful(j); if (nt == JOB_NOP) continue; r = transaction_add_job_and_dependencies(tr, nt, dep, ret, TRANSACTION_MATTERS | (flags & TRANSACTION_IGNORE_ORDER) | TRANSACTION_PROCESS_PROPAGATE_STOP_GRACEFUL, e); if (r < 0) { if (r != -EBADR) /* job type not applicable */ return r; sd_bus_error_free(e); } } } if (type == JOB_RELOAD) transaction_add_propagate_reload_jobs(tr, ret->unit, ret, flags & TRANSACTION_IGNORE_ORDER); /* JOB_VERIFY_ACTIVE requires no dependency handling */ return 0; fail: /* Recursive call failed to add required jobs so let's drop top level job as well. */ log_unit_debug_errno(unit, r, "Cannot add dependency job to transaction, deleting job %s/%s again: %s", unit->id, job_type_to_string(type), bus_error_message(e, r)); transaction_delete_job(tr, ret, /* delete_dependencies= */ false); return r; } static bool shall_stop_on_isolate(Transaction *tr, Unit *u) { assert(tr); assert(u); if (u->ignore_on_isolate) return false; /* Is there already something listed for this? */ if (hashmap_contains(tr->jobs, u)) return false; return true; } int transaction_add_isolate_jobs(Transaction *tr, Manager *m) { Unit *u; char *k; int r; assert(tr); assert(m); HASHMAP_FOREACH_KEY(u, k, m->units) { _cleanup_(sd_bus_error_free) sd_bus_error e = SD_BUS_ERROR_NULL; Unit *o; /* Ignore aliases */ if (u->id != k) continue; /* No need to stop inactive units */ if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(u)) && !u->job) continue; if (!shall_stop_on_isolate(tr, u)) continue; /* Keep units that are triggered by units we want to keep around. */ bool keep = false; UNIT_FOREACH_DEPENDENCY(o, u, UNIT_ATOM_TRIGGERED_BY) if (!shall_stop_on_isolate(tr, o)) { keep = true; break; } if (keep) continue; r = transaction_add_job_and_dependencies(tr, JOB_STOP, u, tr->anchor_job, TRANSACTION_MATTERS, &e); if (r < 0) log_unit_warning_errno(u, r, "Cannot add isolate job, ignoring: %s", bus_error_message(&e, r)); } return 0; } int transaction_add_triggering_jobs(Transaction *tr, Unit *u) { Unit *trigger; int r; assert(tr); assert(u); UNIT_FOREACH_DEPENDENCY(trigger, u, UNIT_ATOM_TRIGGERED_BY) { _cleanup_(sd_bus_error_free) sd_bus_error e = SD_BUS_ERROR_NULL; /* No need to stop inactive jobs */ if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(trigger)) && !trigger->job) continue; /* Is there already something listed for this? */ if (hashmap_contains(tr->jobs, trigger)) continue; r = transaction_add_job_and_dependencies(tr, JOB_STOP, trigger, tr->anchor_job, TRANSACTION_MATTERS, &e); if (r < 0) log_unit_warning_errno(u, r, "Cannot add triggered by job, ignoring: %s", bus_error_message(&e, r)); } return 0; } Transaction *transaction_new(bool irreversible) { Transaction *tr; tr = new0(Transaction, 1); if (!tr) return NULL; tr->jobs = hashmap_new(NULL); if (!tr->jobs) return mfree(tr); tr->irreversible = irreversible; return tr; } Transaction *transaction_free(Transaction *tr) { if (!tr) return NULL; assert(hashmap_isempty(tr->jobs)); hashmap_free(tr->jobs); return mfree(tr); } Transaction *transaction_abort_and_free(Transaction *tr) { if (!tr) return NULL; transaction_abort(tr); return transaction_free(tr); }