diff options
| -rw-r--r-- | Makefile.am | 2 | ||||
| -rw-r--r-- | src/core/job.h | 1 | ||||
| -rw-r--r-- | src/core/manager.c | 1100 | ||||
| -rw-r--r-- | src/core/manager.h | 7 | ||||
| -rw-r--r-- | src/core/transaction.c | 1101 | ||||
| -rw-r--r-- | src/core/transaction.h | 36 |
6 files changed, 1141 insertions, 1106 deletions
diff --git a/Makefile.am b/Makefile.am index 4d13eea841..cc284a7093 100644 --- a/Makefile.am +++ b/Makefile.am @@ -681,6 +681,8 @@ libsystemd_core_la_SOURCES = \ src/core/job.h \ src/core/manager.c \ src/core/manager.h \ + src/core/transaction.c \ + src/core/transaction.h \ src/core/load-fragment.c \ src/core/load-fragment.h \ src/core/service.c \ diff --git a/src/core/job.h b/src/core/job.h index 4c543f20b1..e25fc26235 100644 --- a/src/core/job.h +++ b/src/core/job.h @@ -34,6 +34,7 @@ typedef enum JobMode JobMode; typedef enum JobResult JobResult; #include "manager.h" +#include "transaction.h" #include "unit.h" #include "hashmap.h" #include "list.h" diff --git a/src/core/manager.c b/src/core/manager.c index 52702f3b4c..f070295d88 100644 --- a/src/core/manager.c +++ b/src/core/manager.c @@ -44,6 +44,7 @@ #include <systemd/sd-daemon.h> #include "manager.h" +#include "transaction.h" #include "hashmap.h" #include "macro.h" #include "strv.h" @@ -653,1105 +654,6 @@ int manager_startup(Manager *m, FILE *serialization, FDSet *fds) { return r; } -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); - - if (!j->installed) - 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, true); - - assert(hashmap_isempty(tr->jobs)); - - assert(!tr->anchor); -} - -static void transaction_find_jobs_that_matter_to_anchor(Transaction *tr, Job *j, unsigned generation) { - JobDependency *l; - - assert(tr); - - /* 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. */ - - if (j) - l = j->subject_list; - else - l = tr->anchor; - - LIST_FOREACH(subject, l, l) { - - /* This link does not matter */ - if (!l->matters) - continue; - - /* This unit has already been marked */ - if (l->object->generation == generation) - continue; - - l->object->matters_to_anchor = true; - l->object->generation = generation; - - transaction_find_jobs_that_matter_to_anchor(tr, l->object, generation); - } -} - -static void transaction_merge_and_delete_job(Transaction *tr, Job *j, Job *other, JobType t) { - JobDependency *l, *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->override = j->override || other->override; - - 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) { - JobDependency *l; - - 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 *j) { - Job *k; - - assert(j); - - /* 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, j) - 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_debug("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_debug("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_debug("Fixing conflicting jobs by deleting job %s/%s", 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, DBusError *e) { - Job *j; - Iterator i; - 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, i) { - JobType t; - Job *k; - - t = j->type; - LIST_FOREACH(transaction, k, j->transaction_next) { - if (job_type_merge(&t, k->type) >= 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 */ - dbus_set_error(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); - return r; - } - } - - /* Second step, merge the jobs. */ - HASHMAP_FOREACH(j, tr->jobs, i) { - JobType t = j->type; - Job *k; - - /* Merge all transactions */ - LIST_FOREACH(transaction, k, j->transaction_next) - assert_se(job_type_merge(&t, k->type) == 0); - - /* If an active job is mergeable, merge it too */ - if (j->unit->job) - job_type_merge(&t, j->unit->job->type); /* Might fail. Which is OK */ - - while ((k = j->transaction_next)) { - if (j->installed) { - transaction_merge_and_delete_job(tr, k, j, t); - j = k; - } else - transaction_merge_and_delete_job(tr, j, k, t); - } - - if (j->unit->job && !j->installed) - transaction_merge_and_delete_job(tr, j, j->unit->job, t); - - assert(!j->transaction_next); - assert(!j->transaction_prev); - } - - return 0; -} - -static void transaction_drop_redundant(Transaction *tr) { - bool again; - - assert(tr); - - /* Goes through the transaction and removes all jobs that are - * a noop */ - - do { - Job *j; - Iterator i; - - again = false; - - HASHMAP_FOREACH(j, tr->jobs, i) { - bool changes_something = false; - Job *k; - - LIST_FOREACH(transaction, k, j) { - - if (!job_is_anchor(k) && - (k->installed || job_type_is_redundant(k->type, unit_active_state(k->unit))) && - (!k->unit->job || !job_type_is_conflicting(k->type, k->unit->job->type))) - continue; - - changes_something = true; - break; - } - - if (changes_something) - continue; - - /* log_debug("Found redundant job %s/%s, dropping.", j->unit->id, job_type_to_string(j->type)); */ - transaction_delete_job(tr, j, false); - again = true; - break; - } - - } while (again); -} - -static bool unit_matters_to_anchor(Unit *u, Job *j) { - assert(u); - assert(!j->transaction_prev); - - /* Checks whether at least one of the jobs for this unit - * matters to the anchor. */ - - LIST_FOREACH(transaction, j, j) - if (j->matters_to_anchor) - return true; - - return false; -} - -static int transaction_verify_order_one(Transaction *tr, Job *j, Job *from, unsigned generation, DBusError *e) { - Iterator i; - Unit *u; - 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 cycle we try to break it. */ - - /* Have we seen this before? */ - if (j->generation == generation) { - Job *k, *delete; - - /* 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. */ - log_warning("Found ordering cycle on %s/%s", j->unit->id, job_type_to_string(j->type)); - - delete = NULL; - for (k = from; k; k = ((k->generation == generation && k->marker != k) ? k->marker : NULL)) { - - log_info("Walked on cycle path to %s/%s", k->unit->id, job_type_to_string(k->type)); - - if (!delete && - !k->installed && - !unit_matters_to_anchor(k->unit, 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; - } - - - if (delete) { - log_warning("Breaking ordering cycle by deleting job %s/%s", delete->unit->id, job_type_to_string(delete->type)); - transaction_delete_unit(tr, delete->unit); - return -EAGAIN; - } - - log_error("Unable to break cycle"); - - dbus_set_error(e, BUS_ERROR_TRANSACTION_ORDER_IS_CYCLIC, "Transaction order is cyclic. See system logs for details."); - return -ENOEXEC; - } - - /* 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 ? from : j; - j->generation = generation; - - /* We assume that the the dependencies are bidirectional, and - * hence can ignore UNIT_AFTER */ - SET_FOREACH(u, j->unit->dependencies[UNIT_BEFORE], i) { - 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; - } - - 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, DBusError *e) { - Job *j; - int r; - Iterator i; - 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, i) - if ((r = transaction_verify_order_one(tr, j, NULL, g, e)) < 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 { - Iterator i; - Job *j; - - again = false; - - HASHMAP_FOREACH(j, tr->jobs, i) { - if (j->object_list) { - /* log_debug("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"); */ - continue; - } - - /* log_debug("Garbage collecting job %s/%s", j->unit->id, job_type_to_string(j->type)); */ - transaction_delete_job(tr, j, true); - again = true; - break; - } - - } while (again); -} - -static int transaction_is_destructive(Transaction *tr, DBusError *e) { - Iterator i; - Job *j; - - assert(tr); - - /* Checks whether applying this transaction means that - * existing jobs would be replaced */ - - HASHMAP_FOREACH(j, tr->jobs, i) { - - /* Assume merged */ - assert(!j->transaction_prev); - assert(!j->transaction_next); - - if (j->unit->job && - j->unit->job != j && - !job_type_is_superset(j->type, j->unit->job->type)) { - - dbus_set_error(e, BUS_ERROR_TRANSACTION_IS_DESTRUCTIVE, "Transaction is destructive."); - return -EEXIST; - } - } - - return 0; -} - -static void transaction_minimize_impact(Transaction *tr) { - bool again; - assert(tr); - - /* Drops all unnecessary jobs that reverse already active jobs - * or that stop a running service. */ - - do { - Job *j; - Iterator i; - - again = false; - - HASHMAP_FOREACH(j, tr->jobs, i) { - LIST_FOREACH(transaction, j, j) { - 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_debug("%s/%s would stop a running service.", j->unit->id, job_type_to_string(j->type)); - - if (changes_existing_job) - log_debug("%s/%s would change existing job.", j->unit->id, job_type_to_string(j->type)); - - /* Ok, let's get rid of this */ - log_debug("Deleting %s/%s to minimize impact.", j->unit->id, job_type_to_string(j->type)); - - transaction_delete_job(tr, j, true); - again = true; - break; - } - - if (again) - break; - } - - } while (again); -} - -static int transaction_apply(Transaction *tr, Manager *m, JobMode mode) { - Iterator i; - Job *j; - int r; - - /* Moves the transaction jobs to the set of active jobs */ - - if (mode == JOB_ISOLATE) { - - /* When isolating first kill all installed jobs which - * aren't part of the new transaction */ - rescan: - HASHMAP_FOREACH(j, m->jobs, i) { - assert(j->installed); - - if (hashmap_get(tr->jobs, j->unit)) - continue; - - /* 'j' itself is safe to remove, but if other jobs - are invalidated recursively, our iterator may become - invalid and we need to start over. */ - if (job_finish_and_invalidate(j, JOB_CANCELED) > 0) - goto rescan; - } - } - - HASHMAP_FOREACH(j, tr->jobs, i) { - /* Assume merged */ - assert(!j->transaction_prev); - assert(!j->transaction_next); - - if (j->installed) - continue; - - r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j); - if (r < 0) - goto rollback; - } - - while ((j = hashmap_steal_first(tr->jobs))) { - Job *uj; - if (j->installed) { - /* log_debug("Skipping already installed job %s/%s as %u", j->unit->id, job_type_to_string(j->type), (unsigned) j->id); */ - continue; - } - - uj = j->unit->job; - if (uj) { - job_uninstall(uj); - job_free(uj); - } - - j->unit->job = j; - j->installed = true; - m->n_installed_jobs ++; - - /* We're fully installed. Now let's free data we don't - * need anymore. */ - - assert(!j->transaction_next); - assert(!j->transaction_prev); - - /* Clean the job dependencies */ - transaction_unlink_job(tr, j, false); - - job_add_to_run_queue(j); - job_add_to_dbus_queue(j); - job_start_timer(j); - - log_debug("Installed new job %s/%s as %u", j->unit->id, job_type_to_string(j->type), (unsigned) j->id); - } - - assert(!tr->anchor); - - return 0; - -rollback: - - HASHMAP_FOREACH(j, tr->jobs, i) { - if (j->installed) - continue; - - hashmap_remove(m->jobs, UINT32_TO_PTR(j->id)); - } - - return r; -} - -static int transaction_activate(Transaction *tr, Manager *m, JobMode mode, DBusError *e) { - int r; - unsigned generation = 1; - - assert(tr); - - /* This applies the changes recorded in tr->jobs to - * the actual list of jobs, if possible. */ - - /* First step: figure out which jobs matter */ - transaction_find_jobs_that_matter_to_anchor(tr, NULL, 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) { - log_warning("Requested transaction contains an unfixable cyclic ordering dependency: %s", bus_error(e, r)); - return 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) { - log_warning("Requested transaction contains unmergeable jobs: %s", bus_error(e, r)); - return 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 */ - if (mode == JOB_FAIL) { - r = transaction_is_destructive(tr, e); - if (r < 0) { - log_notice("Requested transaction contradicts existing jobs: %s", bus_error(e, r)); - return r; - } - } - - /* Tenth step: apply changes */ - r = transaction_apply(tr, m, mode); - if (r < 0) { - log_warning("Failed to apply transaction: %s", strerror(-r)); - return r; - } - - assert(hashmap_isempty(tr->jobs)); - assert(!tr->anchor); - - return 0; -} - -static Job* transaction_add_one_job(Transaction *tr, JobType type, Unit *unit, bool override, 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, j, f) { - assert(j->unit == unit); - - if (j->type == type) { - if (is_new) - *is_new = false; - return j; - } - } - - if (unit->job && unit->job->type == type) - j = unit->job; - else { - j = job_new(unit->manager, type, unit); - if (!j) - return NULL; - } - - j->generation = 0; - j->marker = NULL; - j->matters_to_anchor = false; - j->override = override; - - LIST_PREPEND(Job, transaction, f, j); - - if (hashmap_replace(tr->jobs, unit, f) < 0) { - LIST_REMOVE(Job, transaction, f, j); - job_free(j); - return NULL; - } - - if (is_new) - *is_new = true; - - /* log_debug("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, tr); - - while (j->object_list) { - Job *other = j->object_list->matters ? j->object_list->subject : NULL; - - job_dependency_free(j->object_list, tr); - - if (other && delete_dependencies) { - log_debug("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); - } - } -} - -static int transaction_add_job_and_dependencies( - Transaction *tr, - JobType type, - Unit *unit, - Job *by, - bool matters, - bool override, - bool conflicts, - bool ignore_requirements, - bool ignore_order, - DBusError *e, - Job **_ret) { - Job *ret; - Iterator i; - Unit *dep; - int r; - bool is_new; - - assert(tr); - assert(type < _JOB_TYPE_MAX); - assert(unit); - - /* log_debug("Pulling in %s/%s from %s/%s", */ - /* unit->id, job_type_to_string(type), */ - /* by ? by->unit->id : "NA", */ - /* by ? job_type_to_string(by->type) : "NA"); */ - - if (unit->load_state != UNIT_LOADED && - unit->load_state != UNIT_ERROR && - unit->load_state != UNIT_MASKED) { - dbus_set_error(e, BUS_ERROR_LOAD_FAILED, "Unit %s is not loaded properly.", unit->id); - return -EINVAL; - } - - if (type != JOB_STOP && unit->load_state == UNIT_ERROR) { - dbus_set_error(e, BUS_ERROR_LOAD_FAILED, - "Unit %s failed to load: %s. " - "See system logs and 'systemctl status %s' for details.", - unit->id, - strerror(-unit->load_error), - unit->id); - return -EINVAL; - } - - if (type != JOB_STOP && unit->load_state == UNIT_MASKED) { - dbus_set_error(e, BUS_ERROR_MASKED, "Unit %s is masked.", unit->id); - return -EINVAL; - } - - if (!unit_job_is_applicable(unit, type)) { - dbus_set_error(e, BUS_ERROR_JOB_TYPE_NOT_APPLICABLE, "Job type %s is not applicable for unit %s.", job_type_to_string(type), unit->id); - return -EBADR; - } - - /* First add the job. */ - ret = transaction_add_one_job(tr, type, unit, override, &is_new); - if (!ret) - return -ENOMEM; - - ret->ignore_order = ret->ignore_order || ignore_order; - - /* Then, add a link to the job. */ - if (!job_dependency_new(by, ret, matters, conflicts, tr)) - return -ENOMEM; - - if (is_new && !ignore_requirements) { - Set *following; - - /* 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, i) { - r = transaction_add_job_and_dependencies(tr, type, dep, ret, false, override, false, false, ignore_order, e, NULL); - if (r < 0) { - log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); - - if (e) - dbus_error_free(e); - } - } - - set_free(following); - } - - /* Finally, recursively add in all dependencies. */ - if (type == JOB_START || type == JOB_RELOAD_OR_START) { - SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUIRES], i) { - r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, true, override, false, false, ignore_order, e, NULL); - if (r < 0) { - if (r != -EBADR) - goto fail; - - if (e) - dbus_error_free(e); - } - } - - SET_FOREACH(dep, ret->unit->dependencies[UNIT_BIND_TO], i) { - r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, true, override, false, false, ignore_order, e, NULL); - if (r < 0) { - if (r != -EBADR) - goto fail; - - if (e) - dbus_error_free(e); - } - } - - SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUIRES_OVERRIDABLE], i) { - r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, !override, override, false, false, ignore_order, e, NULL); - if (r < 0) { - log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); - - if (e) - dbus_error_free(e); - } - } - - SET_FOREACH(dep, ret->unit->dependencies[UNIT_WANTS], i) { - r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, false, false, false, false, ignore_order, e, NULL); - if (r < 0) { - log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); - - if (e) - dbus_error_free(e); - } - } - - SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUISITE], i) { - r = transaction_add_job_and_dependencies(tr, JOB_VERIFY_ACTIVE, dep, ret, true, override, false, false, ignore_order, e, NULL); - if (r < 0) { - if (r != -EBADR) - goto fail; - - if (e) - dbus_error_free(e); - } - } - - SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUISITE_OVERRIDABLE], i) { - r = transaction_add_job_and_dependencies(tr, JOB_VERIFY_ACTIVE, dep, ret, !override, override, false, false, ignore_order, e, NULL); - if (r < 0) { - log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); - - if (e) - dbus_error_free(e); - } - } - - SET_FOREACH(dep, ret->unit->dependencies[UNIT_CONFLICTS], i) { - r = transaction_add_job_and_dependencies(tr, JOB_STOP, dep, ret, true, override, true, false, ignore_order, e, NULL); - if (r < 0) { - if (r != -EBADR) - goto fail; - - if (e) - dbus_error_free(e); - } - } - - SET_FOREACH(dep, ret->unit->dependencies[UNIT_CONFLICTED_BY], i) { - r = transaction_add_job_and_dependencies(tr, JOB_STOP, dep, ret, false, override, false, false, ignore_order, e, NULL); - if (r < 0) { - log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); - - if (e) - dbus_error_free(e); - } - } - - } - - if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) { - - SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUIRED_BY], i) { - r = transaction_add_job_and_dependencies(tr, type, dep, ret, true, override, false, false, ignore_order, e, NULL); - if (r < 0) { - if (r != -EBADR) - goto fail; - - if (e) - dbus_error_free(e); - } - } - - SET_FOREACH(dep, ret->unit->dependencies[UNIT_BOUND_BY], i) { - r = transaction_add_job_and_dependencies(tr, type, dep, ret, true, override, false, false, ignore_order, e, NULL); - if (r < 0) { - if (r != -EBADR) - goto fail; - - if (e) - dbus_error_free(e); - } - } - } - - if (type == JOB_RELOAD || type == JOB_RELOAD_OR_START) { - - SET_FOREACH(dep, ret->unit->dependencies[UNIT_PROPAGATE_RELOAD_TO], i) { - r = transaction_add_job_and_dependencies(tr, JOB_RELOAD, dep, ret, false, override, false, false, ignore_order, e, NULL); - if (r < 0) { - log_warning("Cannot add dependency reload job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); - - if (e) - dbus_error_free(e); - } - } - } - - /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */ - } - - if (_ret) - *_ret = ret; - - return 0; - -fail: - return r; -} - -static int transaction_add_isolate_jobs(Transaction *tr, Manager *m) { - Iterator i; - Unit *u; - char *k; - int r; - - assert(tr); - assert(m); - - HASHMAP_FOREACH_KEY(u, k, m->units, i) { - - /* ignore aliases */ - if (u->id != k) - continue; - - if (u->ignore_on_isolate) - continue; - - /* No need to stop inactive jobs */ - if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(u)) && !u->job) - continue; - - /* Is there already something listed for this? */ - if (hashmap_get(tr->jobs, u)) - continue; - - r = transaction_add_job_and_dependencies(tr, JOB_STOP, u, NULL, true, false, false, false, false, NULL, NULL); - if (r < 0) - log_warning("Cannot add isolate job for unit %s, ignoring: %s", u->id, strerror(-r)); - } - - return 0; -} - -static Transaction *transaction_new(void) { - Transaction *tr; - - tr = new0(Transaction, 1); - if (!tr) - return NULL; - - tr->jobs = hashmap_new(trivial_hash_func, trivial_compare_func); - if (!tr->jobs) { - free(tr); - return NULL; - } - - return tr; -} - -static void transaction_free(Transaction *tr) { - assert(hashmap_isempty(tr->jobs)); - hashmap_free(tr->jobs); - free(tr); -} - int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool override, DBusError *e, Job **_ret) { int r; Job *ret; diff --git a/src/core/manager.h b/src/core/manager.h index 2bf7b7ae5e..20b743ab35 100644 --- a/src/core/manager.h +++ b/src/core/manager.h @@ -33,7 +33,6 @@ #define MANAGER_MAX_NAMES 131072 /* 128K */ typedef struct Manager Manager; -typedef struct Transaction Transaction; typedef enum WatchType WatchType; typedef struct Watch Watch; @@ -92,12 +91,6 @@ struct Watch { #include "dbus.h" #include "path-lookup.h" -struct Transaction { - /* Jobs to be added */ - Hashmap *jobs; /* Unit object => Job object list 1:1 */ - JobDependency *anchor; -}; - struct Manager { /* Note that the set of units we know of is allowed to be * inconsistent. However the subset of it that is loaded may diff --git a/src/core/transaction.c b/src/core/transaction.c new file mode 100644 index 0000000000..8fa89a7be3 --- /dev/null +++ b/src/core/transaction.c @@ -0,0 +1,1101 @@ +#include "transaction.h" +#include "bus-errors.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); + + if (!j->installed) + 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); +} + +void transaction_abort(Transaction *tr) { + Job *j; + + assert(tr); + + while ((j = hashmap_first(tr->jobs))) + transaction_delete_job(tr, j, true); + + assert(hashmap_isempty(tr->jobs)); + + assert(!tr->anchor); +} + +static void transaction_find_jobs_that_matter_to_anchor(Transaction *tr, Job *j, unsigned generation) { + JobDependency *l; + + assert(tr); + + /* 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. */ + + if (j) + l = j->subject_list; + else + l = tr->anchor; + + LIST_FOREACH(subject, l, l) { + + /* This link does not matter */ + if (!l->matters) + continue; + + /* This unit has already been marked */ + if (l->object->generation == generation) + continue; + + l->object->matters_to_anchor = true; + l->object->generation = generation; + + transaction_find_jobs_that_matter_to_anchor(tr, l->object, generation); + } +} + +static void transaction_merge_and_delete_job(Transaction *tr, Job *j, Job *other, JobType t) { + JobDependency *l, *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->override = j->override || other->override; + + 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) { + JobDependency *l; + + 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 *j) { + Job *k; + + assert(j); + + /* 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, j) + 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_debug("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_debug("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_debug("Fixing conflicting jobs by deleting job %s/%s", 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, DBusError *e) { + Job *j; + Iterator i; + 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, i) { + JobType t; + Job *k; + + t = j->type; + LIST_FOREACH(transaction, k, j->transaction_next) { + if (job_type_merge(&t, k->type) >= 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 */ + dbus_set_error(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); + return r; + } + } + + /* Second step, merge the jobs. */ + HASHMAP_FOREACH(j, tr->jobs, i) { + JobType t = j->type; + Job *k; + + /* Merge all transactions */ + LIST_FOREACH(transaction, k, j->transaction_next) + assert_se(job_type_merge(&t, k->type) == 0); + + /* If an active job is mergeable, merge it too */ + if (j->unit->job) + job_type_merge(&t, j->unit->job->type); /* Might fail. Which is OK */ + + while ((k = j->transaction_next)) { + if (j->installed) { + transaction_merge_and_delete_job(tr, k, j, t); + j = k; + } else + transaction_merge_and_delete_job(tr, j, k, t); + } + + if (j->unit->job && !j->installed) + transaction_merge_and_delete_job(tr, j, j->unit->job, t); + + assert(!j->transaction_next); + assert(!j->transaction_prev); + } + + return 0; +} + +static void transaction_drop_redundant(Transaction *tr) { + bool again; + + assert(tr); + + /* Goes through the transaction and removes all jobs that are + * a noop */ + + do { + Job *j; + Iterator i; + + again = false; + + HASHMAP_FOREACH(j, tr->jobs, i) { + bool changes_something = false; + Job *k; + + LIST_FOREACH(transaction, k, j) { + + if (!job_is_anchor(k) && + (k->installed || job_type_is_redundant(k->type, unit_active_state(k->unit))) && + (!k->unit->job || !job_type_is_conflicting(k->type, k->unit->job->type))) + continue; + + changes_something = true; + break; + } + + if (changes_something) + continue; + + /* log_debug("Found redundant job %s/%s, dropping.", j->unit->id, job_type_to_string(j->type)); */ + transaction_delete_job(tr, j, false); + again = true; + break; + } + + } while (again); +} + +static bool unit_matters_to_anchor(Unit *u, Job *j) { + assert(u); + assert(!j->transaction_prev); + + /* Checks whether at least one of the jobs for this unit + * matters to the anchor. */ + + LIST_FOREACH(transaction, j, j) + if (j->matters_to_anchor) + return true; + + return false; +} + +static int transaction_verify_order_one(Transaction *tr, Job *j, Job *from, unsigned generation, DBusError *e) { + Iterator i; + Unit *u; + 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 cycle we try to break it. */ + + /* Have we seen this before? */ + if (j->generation == generation) { + Job *k, *delete; + + /* 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. */ + log_warning("Found ordering cycle on %s/%s", j->unit->id, job_type_to_string(j->type)); + + delete = NULL; + for (k = from; k; k = ((k->generation == generation && k->marker != k) ? k->marker : NULL)) { + + log_info("Walked on cycle path to %s/%s", k->unit->id, job_type_to_string(k->type)); + + if (!delete && + !k->installed && + !unit_matters_to_anchor(k->unit, 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; + } + + + if (delete) { + log_warning("Breaking ordering cycle by deleting job %s/%s", delete->unit->id, job_type_to_string(delete->type)); + transaction_delete_unit(tr, delete->unit); + return -EAGAIN; + } + + log_error("Unable to break cycle"); + + dbus_set_error(e, BUS_ERROR_TRANSACTION_ORDER_IS_CYCLIC, "Transaction order is cyclic. See system logs for details."); + return -ENOEXEC; + } + + /* 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 ? from : j; + j->generation = generation; + + /* We assume that the the dependencies are bidirectional, and + * hence can ignore UNIT_AFTER */ + SET_FOREACH(u, j->unit->dependencies[UNIT_BEFORE], i) { + 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; + } + + 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, DBusError *e) { + Job *j; + int r; + Iterator i; + 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, i) + if ((r = transaction_verify_order_one(tr, j, NULL, g, e)) < 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 { + Iterator i; + Job *j; + + again = false; + + HASHMAP_FOREACH(j, tr->jobs, i) { + if (j->object_list) { + /* log_debug("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"); */ + continue; + } + + /* log_debug("Garbage collecting job %s/%s", j->unit->id, job_type_to_string(j->type)); */ + transaction_delete_job(tr, j, true); + again = true; + break; + } + + } while (again); +} + +static int transaction_is_destructive(Transaction *tr, DBusError *e) { + Iterator i; + Job *j; + + assert(tr); + + /* Checks whether applying this transaction means that + * existing jobs would be replaced */ + + HASHMAP_FOREACH(j, tr->jobs, i) { + + /* Assume merged */ + assert(!j->transaction_prev); + assert(!j->transaction_next); + + if (j->unit->job && + j->unit->job != j && + !job_type_is_superset(j->type, j->unit->job->type)) { + + dbus_set_error(e, BUS_ERROR_TRANSACTION_IS_DESTRUCTIVE, "Transaction is destructive."); + return -EEXIST; + } + } + + return 0; +} + +static void transaction_minimize_impact(Transaction *tr) { + bool again; + assert(tr); + + /* Drops all unnecessary jobs that reverse already active jobs + * or that stop a running service. */ + + do { + Job *j; + Iterator i; + + again = false; + + HASHMAP_FOREACH(j, tr->jobs, i) { + LIST_FOREACH(transaction, j, j) { + 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_debug("%s/%s would stop a running service.", j->unit->id, job_type_to_string(j->type)); + + if (changes_existing_job) + log_debug("%s/%s would change existing job.", j->unit->id, job_type_to_string(j->type)); + + /* Ok, let's get rid of this */ + log_debug("Deleting %s/%s to minimize impact.", j->unit->id, job_type_to_string(j->type)); + + transaction_delete_job(tr, j, true); + again = true; + break; + } + + if (again) + break; + } + + } while (again); +} + +static int transaction_apply(Transaction *tr, Manager *m, JobMode mode) { + Iterator i; + Job *j; + int r; + + /* Moves the transaction jobs to the set of active jobs */ + + if (mode == JOB_ISOLATE) { + + /* When isolating first kill all installed jobs which + * aren't part of the new transaction */ + rescan: + HASHMAP_FOREACH(j, m->jobs, i) { + assert(j->installed); + + if (hashmap_get(tr->jobs, j->unit)) + continue; + + /* 'j' itself is safe to remove, but if other jobs + are invalidated recursively, our iterator may become + invalid and we need to start over. */ + if (job_finish_and_invalidate(j, JOB_CANCELED) > 0) + goto rescan; + } + } + + HASHMAP_FOREACH(j, tr->jobs, i) { + /* Assume merged */ + assert(!j->transaction_prev); + assert(!j->transaction_next); + + if (j->installed) + continue; + + r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j); + if (r < 0) + goto rollback; + } + + while ((j = hashmap_steal_first(tr->jobs))) { + Job *uj; + if (j->installed) { + /* log_debug("Skipping already installed job %s/%s as %u", j->unit->id, job_type_to_string(j->type), (unsigned) j->id); */ + continue; + } + + uj = j->unit->job; + if (uj) { + job_uninstall(uj); + job_free(uj); + } + + j->unit->job = j; + j->installed = true; + m->n_installed_jobs ++; + + /* We're fully installed. Now let's free data we don't + * need anymore. */ + + assert(!j->transaction_next); + assert(!j->transaction_prev); + + /* Clean the job dependencies */ + transaction_unlink_job(tr, j, false); + + job_add_to_run_queue(j); + job_add_to_dbus_queue(j); + job_start_timer(j); + + log_debug("Installed new job %s/%s as %u", j->unit->id, job_type_to_string(j->type), (unsigned) j->id); + } + + assert(!tr->anchor); + + return 0; + +rollback: + + HASHMAP_FOREACH(j, tr->jobs, i) { + if (j->installed) + continue; + + hashmap_remove(m->jobs, UINT32_TO_PTR(j->id)); + } + + return r; +} + +int transaction_activate(Transaction *tr, Manager *m, JobMode mode, DBusError *e) { + int r; + unsigned generation = 1; + + assert(tr); + + /* This applies the changes recorded in tr->jobs to + * the actual list of jobs, if possible. */ + + /* First step: figure out which jobs matter */ + transaction_find_jobs_that_matter_to_anchor(tr, NULL, 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) { + log_warning("Requested transaction contains an unfixable cyclic ordering dependency: %s", bus_error(e, r)); + return 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) { + log_warning("Requested transaction contains unmergeable jobs: %s", bus_error(e, r)); + return 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 */ + if (mode == JOB_FAIL) { + r = transaction_is_destructive(tr, e); + if (r < 0) { + log_notice("Requested transaction contradicts existing jobs: %s", bus_error(e, r)); + return r; + } + } + + /* Tenth step: apply changes */ + r = transaction_apply(tr, m, mode); + if (r < 0) { + log_warning("Failed to apply transaction: %s", strerror(-r)); + return r; + } + + assert(hashmap_isempty(tr->jobs)); + assert(!tr->anchor); + + return 0; +} + +static Job* transaction_add_one_job(Transaction *tr, JobType type, Unit *unit, bool override, 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, j, f) { + assert(j->unit == unit); + + if (j->type == type) { + if (is_new) + *is_new = false; + return j; + } + } + + if (unit->job && unit->job->type == type) + j = unit->job; + else { + j = job_new(unit->manager, type, unit); + if (!j) + return NULL; + } + + j->generation = 0; + j->marker = NULL; + j->matters_to_anchor = false; + j->override = override; + + LIST_PREPEND(Job, transaction, f, j); + + if (hashmap_replace(tr->jobs, unit, f) < 0) { + LIST_REMOVE(Job, transaction, f, j); + job_free(j); + return NULL; + } + + if (is_new) + *is_new = true; + + /* log_debug("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, tr); + + while (j->object_list) { + Job *other = j->object_list->matters ? j->object_list->subject : NULL; + + job_dependency_free(j->object_list, tr); + + if (other && delete_dependencies) { + log_debug("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); + } + } +} + +int transaction_add_job_and_dependencies( + Transaction *tr, + JobType type, + Unit *unit, + Job *by, + bool matters, + bool override, + bool conflicts, + bool ignore_requirements, + bool ignore_order, + DBusError *e, + Job **_ret) { + Job *ret; + Iterator i; + Unit *dep; + int r; + bool is_new; + + assert(tr); + assert(type < _JOB_TYPE_MAX); + assert(unit); + + /* log_debug("Pulling in %s/%s from %s/%s", */ + /* unit->id, job_type_to_string(type), */ + /* by ? by->unit->id : "NA", */ + /* by ? job_type_to_string(by->type) : "NA"); */ + + if (unit->load_state != UNIT_LOADED && + unit->load_state != UNIT_ERROR && + unit->load_state != UNIT_MASKED) { + dbus_set_error(e, BUS_ERROR_LOAD_FAILED, "Unit %s is not loaded properly.", unit->id); + return -EINVAL; + } + + if (type != JOB_STOP && unit->load_state == UNIT_ERROR) { + dbus_set_error(e, BUS_ERROR_LOAD_FAILED, + "Unit %s failed to load: %s. " + "See system logs and 'systemctl status %s' for details.", + unit->id, + strerror(-unit->load_error), + unit->id); + return -EINVAL; + } + + if (type != JOB_STOP && unit->load_state == UNIT_MASKED) { + dbus_set_error(e, BUS_ERROR_MASKED, "Unit %s is masked.", unit->id); + return -EINVAL; + } + + if (!unit_job_is_applicable(unit, type)) { + dbus_set_error(e, BUS_ERROR_JOB_TYPE_NOT_APPLICABLE, "Job type %s is not applicable for unit %s.", job_type_to_string(type), unit->id); + return -EBADR; + } + + /* First add the job. */ + ret = transaction_add_one_job(tr, type, unit, override, &is_new); + if (!ret) + return -ENOMEM; + + ret->ignore_order = ret->ignore_order || ignore_order; + + /* Then, add a link to the job. */ + if (!job_dependency_new(by, ret, matters, conflicts, tr)) + return -ENOMEM; + + if (is_new && !ignore_requirements) { + Set *following; + + /* 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, i) { + r = transaction_add_job_and_dependencies(tr, type, dep, ret, false, override, false, false, ignore_order, e, NULL); + if (r < 0) { + log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); + + if (e) + dbus_error_free(e); + } + } + + set_free(following); + } + + /* Finally, recursively add in all dependencies. */ + if (type == JOB_START || type == JOB_RELOAD_OR_START) { + SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUIRES], i) { + r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, true, override, false, false, ignore_order, e, NULL); + if (r < 0) { + if (r != -EBADR) + goto fail; + + if (e) + dbus_error_free(e); + } + } + + SET_FOREACH(dep, ret->unit->dependencies[UNIT_BIND_TO], i) { + r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, true, override, false, false, ignore_order, e, NULL); + if (r < 0) { + if (r != -EBADR) + goto fail; + + if (e) + dbus_error_free(e); + } + } + + SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUIRES_OVERRIDABLE], i) { + r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, !override, override, false, false, ignore_order, e, NULL); + if (r < 0) { + log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); + + if (e) + dbus_error_free(e); + } + } + + SET_FOREACH(dep, ret->unit->dependencies[UNIT_WANTS], i) { + r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, false, false, false, false, ignore_order, e, NULL); + if (r < 0) { + log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); + + if (e) + dbus_error_free(e); + } + } + + SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUISITE], i) { + r = transaction_add_job_and_dependencies(tr, JOB_VERIFY_ACTIVE, dep, ret, true, override, false, false, ignore_order, e, NULL); + if (r < 0) { + if (r != -EBADR) + goto fail; + + if (e) + dbus_error_free(e); + } + } + + SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUISITE_OVERRIDABLE], i) { + r = transaction_add_job_and_dependencies(tr, JOB_VERIFY_ACTIVE, dep, ret, !override, override, false, false, ignore_order, e, NULL); + if (r < 0) { + log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); + + if (e) + dbus_error_free(e); + } + } + + SET_FOREACH(dep, ret->unit->dependencies[UNIT_CONFLICTS], i) { + r = transaction_add_job_and_dependencies(tr, JOB_STOP, dep, ret, true, override, true, false, ignore_order, e, NULL); + if (r < 0) { + if (r != -EBADR) + goto fail; + + if (e) + dbus_error_free(e); + } + } + + SET_FOREACH(dep, ret->unit->dependencies[UNIT_CONFLICTED_BY], i) { + r = transaction_add_job_and_dependencies(tr, JOB_STOP, dep, ret, false, override, false, false, ignore_order, e, NULL); + if (r < 0) { + log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); + + if (e) + dbus_error_free(e); + } + } + + } + + if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) { + + SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUIRED_BY], i) { + r = transaction_add_job_and_dependencies(tr, type, dep, ret, true, override, false, false, ignore_order, e, NULL); + if (r < 0) { + if (r != -EBADR) + goto fail; + + if (e) + dbus_error_free(e); + } + } + + SET_FOREACH(dep, ret->unit->dependencies[UNIT_BOUND_BY], i) { + r = transaction_add_job_and_dependencies(tr, type, dep, ret, true, override, false, false, ignore_order, e, NULL); + if (r < 0) { + if (r != -EBADR) + goto fail; + + if (e) + dbus_error_free(e); + } + } + } + + if (type == JOB_RELOAD || type == JOB_RELOAD_OR_START) { + + SET_FOREACH(dep, ret->unit->dependencies[UNIT_PROPAGATE_RELOAD_TO], i) { + r = transaction_add_job_and_dependencies(tr, JOB_RELOAD, dep, ret, false, override, false, false, ignore_order, e, NULL); + if (r < 0) { + log_warning("Cannot add dependency reload job for unit %s, ignoring: %s", dep->id, bus_error(e, r)); + + if (e) + dbus_error_free(e); + } + } + } + + /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */ + } + + if (_ret) + *_ret = ret; + + return 0; + +fail: + return r; +} + +int transaction_add_isolate_jobs(Transaction *tr, Manager *m) { + Iterator i; + Unit *u; + char *k; + int r; + + assert(tr); + assert(m); + + HASHMAP_FOREACH_KEY(u, k, m->units, i) { + + /* ignore aliases */ + if (u->id != k) + continue; + + if (u->ignore_on_isolate) + continue; + + /* No need to stop inactive jobs */ + if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(u)) && !u->job) + continue; + + /* Is there already something listed for this? */ + if (hashmap_get(tr->jobs, u)) + continue; + + r = transaction_add_job_and_dependencies(tr, JOB_STOP, u, NULL, true, false, false, false, false, NULL, NULL); + if (r < 0) + log_warning("Cannot add isolate job for unit %s, ignoring: %s", u->id, strerror(-r)); + } + + return 0; +} + +Transaction *transaction_new(void) { + Transaction *tr; + + tr = new0(Transaction, 1); + if (!tr) + return NULL; + + tr->jobs = hashmap_new(trivial_hash_func, trivial_compare_func); + if (!tr->jobs) { + free(tr); + return NULL; + } + + return tr; +} + +void transaction_free(Transaction *tr) { + assert(hashmap_isempty(tr->jobs)); + hashmap_free(tr->jobs); + free(tr); +} diff --git a/src/core/transaction.h b/src/core/transaction.h new file mode 100644 index 0000000000..d519ffb1f5 --- /dev/null +++ b/src/core/transaction.h @@ -0,0 +1,36 @@ +#ifndef footransactionhfoo +#define footransactionhfoo + +typedef struct Transaction Transaction; + +#include "unit.h" +#include "manager.h" +#include "job.h" +#include "hashmap.h" + +struct Transaction { + /* Jobs to be added */ + Hashmap *jobs; /* Unit object => Job object list 1:1 */ + JobDependency *anchor; +}; + +Transaction *transaction_new(void); +void transaction_free(Transaction *tr); + +int transaction_add_job_and_dependencies( + Transaction *tr, + JobType type, + Unit *unit, + Job *by, + bool matters, + bool override, + bool conflicts, + bool ignore_requirements, + bool ignore_order, + DBusError *e, + Job **_ret); +int transaction_activate(Transaction *tr, Manager *m, JobMode mode, DBusError *e); +int transaction_add_isolate_jobs(Transaction *tr, Manager *m); +void transaction_abort(Transaction *tr); + +#endif |