manager.c takes care of the main loop, unit management, signal handling, ...
transaction.c computes transactions.
After split:
manager.c: 65 KB
transaction.c: 40 KB
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 \
typedef enum JobResult JobResult;
#include "manager.h"
+#include "transaction.h"
#include "unit.h"
#include "hashmap.h"
#include "list.h"
#include <systemd/sd-daemon.h>
#include "manager.h"
+#include "transaction.h"
#include "hashmap.h"
#include "macro.h"
#include "strv.h"
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;
#define MANAGER_MAX_NAMES 131072 /* 128K */
typedef struct Manager Manager;
-typedef struct Transaction Transaction;
typedef enum WatchType WatchType;
typedef struct Watch 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
--- /dev/null
+#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);
+}
--- /dev/null
+#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
projects / systemd / commitdiff