free(m);
}
+static void transaction_delete_job(Manager *m, Job *j) {
+ assert(m);
+ assert(j);
+
+ /* Deletes one job from the transaction */
+
+ manager_transaction_unlink_job(m, j);
+
+ if (!j->linked)
+ job_free(j);
+}
+
+static void transaction_delete_name(Manager *m, Name *n) {
+ Job *j;
+
+ /* Deletes all jobs associated with a certain name from the
+ * transaction */
+
+ while ((j = hashmap_get(m->transaction_jobs, n)))
+ transaction_delete_job(m, j);
+}
+
static void transaction_abort(Manager *m) {
Job *j;
while ((j = hashmap_first(m->transaction_jobs)))
if (j->linked)
- manager_transaction_delete_job(m, j);
+ transaction_delete_job(m, j);
else
job_free(j);
assert(m);
+ /* A recursive sweep through the graph that marks all names
+ * 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. */
+
for (l = j ? j->subject_list : m->transaction_anchor; l; l = l->subject_next) {
/* This link does not matter */
}
}
-static bool types_match(JobType a, JobType b, JobType c, JobType d) {
- return
- (a == c && b == d) ||
- (a == d && b == c);
-}
-
-static int types_merge(JobType *a, JobType b) {
- if (*a == b)
- return 0;
-
- if (types_match(*a, b, JOB_START, JOB_VERIFY_STARTED))
- *a = JOB_START;
- else if (types_match(*a, b, JOB_START, JOB_RELOAD) ||
- types_match(*a, b, JOB_START, JOB_RELOAD_OR_START) ||
- types_match(*a, b, JOB_VERIFY_STARTED, JOB_RELOAD_OR_START) ||
- types_match(*a, b, JOB_RELOAD, JOB_RELOAD_OR_START))
- *a = JOB_RELOAD_OR_START;
- else if (types_match(*a, b, JOB_START, JOB_RESTART) ||
- types_match(*a, b, JOB_START, JOB_TRY_RESTART) ||
- types_match(*a, b, JOB_VERIFY_STARTED, JOB_RESTART) ||
- types_match(*a, b, JOB_RELOAD, JOB_RESTART) ||
- types_match(*a, b, JOB_RELOAD_OR_START, JOB_RESTART) ||
- types_match(*a, b, JOB_RELOAD_OR_START, JOB_TRY_RESTART) ||
- types_match(*a, b, JOB_RESTART, JOB_TRY_RESTART))
- *a = JOB_RESTART;
- else if (types_match(*a, b, JOB_VERIFY_STARTED, JOB_RELOAD))
- *a = JOB_RELOAD;
- else if (types_match(*a, b, JOB_VERIFY_STARTED, JOB_TRY_RESTART) ||
- types_match(*a, b, JOB_RELOAD, JOB_TRY_RESTART))
- *a = JOB_TRY_RESTART;
-
- return -EEXIST;
-}
-
static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
JobDependency *l, *last;
assert(j->name == other->name);
assert(!j->linked);
+ /* Merges 'other' into 'j' and then deletes j. */
+
j->type = t;
j->state = JOB_WAITING;
+ j->forced = j->forced || other->forced;
j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
/* Kill the other job */
other->subject_list = NULL;
other->object_list = NULL;
- manager_transaction_delete_job(m, other);
+ transaction_delete_job(m, other);
+}
+
+static int delete_one_unmergeable_job(Manager *m, Job *j) {
+ Job *k;
+
+ assert(j);
+
+ /* Tries to delete one item in the linked list
+ * j->transaction_next->transaction_next->... that conflicts
+ * whith 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 */
+ for (; j; j = j->transaction_next)
+ for (k = j->transaction_next; k; k = k->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)
+ 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("Try to fix job merging by deleting job %s/%s", name_id(d->name), job_type_to_string(d->type));
+ transaction_delete_job(m, d);
+ return 0;
+ }
+
+ return -EINVAL;
}
static int transaction_merge_jobs(Manager *m) {
assert(m);
+ /* First step, check whether any of the jobs for one specific
+ * task conflict. If so, try to drop one of them. */
+ HASHMAP_FOREACH(j, m->transaction_jobs, state) {
+ JobType t;
+ Job *k;
+
+ t = j->type;
+ for (k = j->transaction_next; k; k = k->transaction_next) {
+ if ((r = 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 */
+
+ if ((r = delete_one_unmergeable_job(m, j)) >= 0)
+ /* Ok, we managed to drop one, now
+ * let's ask our callers to call us
+ * again after garbage collecting */
+ return -EAGAIN;
+
+ /* We couldn't merge anything. Failure */
+ return r;
+ }
+ }
+
+ /* Second step, merge the jobs. */
HASHMAP_FOREACH(j, m->transaction_jobs, state) {
JobType t = j->type;
Job *k;
+ /* Merge all transactions */
for (k = j->transaction_next; k; k = k->transaction_next)
- if ((r = types_merge(&t, k->type)) < 0)
- return r;
+ assert_se(job_type_merge(&t, k->type) == 0);
+
+ /* If an active job is mergeable, merge it too */
+ if (j->name->meta.job)
+ job_type_merge(&t, j->name->meta.job->type); /* Might fail. Which is OK */
while ((k = j->transaction_next)) {
if (j->linked) {
return 0;
}
+static bool name_matters_to_anchor(Name *n, Job *j) {
+ assert(n);
+ assert(!j->transaction_prev);
+
+ /* Checks whether at least one of the jobs for this name
+ * matters to the anchor. */
+
+ for (; j; j = j->transaction_next)
+ if (j->matters_to_anchor)
+ return true;
+
+ return false;
+}
+
static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation) {
void *state;
Name *n;
assert(m);
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. */
/* Did we find a cycle? */
if (j->marker && j->generation == generation) {
Job *k;
/* So, 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. */
+ * cycle. Let's try to break it. We go backwards in
+ * our path and try to find a suitable job to
+ * remove. We use the marker to find our way back,
+ * since smart how we are we stored our way back in
+ * there. */
for (k = from; k; k = (k->generation == generation ? k->marker : NULL)) {
- if (!k->matters_to_anchor) {
- log_debug("Breaking order cycle by deleting job %s", name_id(k->name));
- manager_transaction_delete_job(m, k);
+
+ if (!k->linked &&
+ !name_matters_to_anchor(k->name, k)) {
+ /* Ok, we can drop this one, so let's
+ * do so. */
+ log_debug("Breaking order cycle by deleting job %s/%s", name_id(k->name), job_type_to_string(k->type));
+ transaction_delete_name(m, k->name);
return -EAGAIN;
}
break;
}
- return -ELOOP;
+ 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 */
j->marker = from;
j->generation = generation;
- /* We assume that the the dependencies are both-ways, and
+ /* We assume that the the dependencies are bidirectional, and
* hence can ignore NAME_AFTER */
-
SET_FOREACH(n, j->name->meta.dependencies[NAME_BEFORE], state) {
Job *o;
+ /* Is there a job for this name? */
if (!(o = hashmap_get(m->transaction_jobs, n)))
+
+ /* Ok, there is no job for this in the
+ * transaction, but maybe there is already one
+ * running? */
if (!(o = n->meta.job))
continue;
}
static int transaction_verify_order(Manager *m, unsigned *generation) {
- bool again;
+ Job *j;
+ int r;
+ void *state;
+
assert(m);
assert(generation);
- do {
- Job *j;
- int r;
- void *state;
-
- again = false;
-
- HASHMAP_FOREACH(j, m->transaction_jobs, state) {
-
- /* Assume merged */
- assert(!j->transaction_next);
- assert(!j->transaction_prev);
-
- if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0) {
-
- /* There was a cycleq, but it was fixed,
- * we need to restart our algorithm */
- if (r == -EAGAIN) {
- again = true;
- break;
- }
+ /* Check if the ordering graph is cyclic. If it is, try to fix
+ * that up by dropping one of the jobs. */
- return r;
- }
- }
- } while (again);
+ HASHMAP_FOREACH(j, m->transaction_jobs, state)
+ if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0)
+ return r;
return 0;
}
assert(m);
+ /* Drop jobs that are not required by any other job */
+
do {
void *state;
Job *j;
if (j->object_list)
continue;
- manager_transaction_delete_job(m, j);
+ log_debug("Garbage collecting job %s/%s", name_id(j->name), job_type_to_string(j->type));
+ transaction_delete_job(m, j);
again = true;
break;
}
/* Checks whether applying this transaction means that
* existing jobs would be replaced */
- HASHMAP_FOREACH(j, m->transaction_jobs, state)
- if (j->name->meta.job && j->name->meta.job != j)
+ HASHMAP_FOREACH(j, m->transaction_jobs, state) {
+
+ /* Assume merged */
+ assert(!j->transaction_prev);
+ assert(!j->transaction_next);
+
+ if (j->name->meta.job &&
+ j->name->meta.job != j &&
+ !job_type_is_superset(j->type, j->name->meta.job->type))
return -EEXIST;
+ }
return 0;
}
+static void transaction_minimize_impact(Manager *m) {
+ bool again;
+ assert(m);
+
+ /* Drops all unnecessary jobs that reverse already active jobs
+ * or that stop a running service. */
+
+ do {
+ Job *j;
+ void *state;
+
+ again = false;
+
+ HASHMAP_FOREACH(j, m->transaction_jobs, state) {
+ for (; j; j = j->transaction_next) {
+
+ /* 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 */
+ if ((j->type != JOB_STOP || NAME_IS_INACTIVE_OR_DEACTIVATING(name_active_state(j->name))) &&
+ (!j->name->meta.job || job_type_is_conflicting(j->type, j->name->meta.job->state)))
+ continue;
+
+ /* Ok, let's get rid of this */
+ log_debug("Deleting %s/%s to minimize impact", name_id(j->name), job_type_to_string(j->type));
+ transaction_delete_job(m, j);
+ again = true;
+ break;
+ }
+
+ if (again)
+ break;
+ }
+
+ } while (again);
+}
+
static int transaction_apply(Manager *m, JobMode mode) {
void *state;
Job *j;
int r;
+ /* Moves the transaction jobs to the set of active jobs */
+
HASHMAP_FOREACH(j, m->transaction_jobs, state) {
+ /* Assume merged */
+ assert(!j->transaction_prev);
+ assert(!j->transaction_next);
+
if (j->linked)
continue;
job_dependency_free(j->object_list);
}
+ m->transaction_anchor = NULL;
+
return 0;
rollback:
return r;
}
-
static int transaction_activate(Manager *m, JobMode mode) {
int r;
unsigned generation = 1;
/* First step: figure out which jobs matter */
transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
- /* Second step: let's merge entries we can merge */
- if ((r = transaction_merge_jobs(m)) < 0)
- goto rollback;
+ /* 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. */
+ transaction_minimize_impact(m);
- /* Third step: verify order makes sense */
- if ((r = transaction_verify_order(m, &generation)) < 0)
- goto rollback;
+ for (;;) {
+ /* Third step: Let's remove unneeded jobs that might
+ * be lurking. */
+ transaction_collect_garbage(m);
+
+ /* Fourth step: verify order makes sense and correct
+ * cycles if necessary and possible */
+ if ((r = transaction_verify_order(m, &generation)) >= 0)
+ break;
+
+ if (r != -EAGAIN)
+ goto rollback;
+
+ /* Let's see if the resulting transaction ordering
+ * graph is still cyclic... */
+ }
+
+ for (;;) {
+ /* Fifth step: let's drop unmergeable entries if
+ * necessary and possible, merge entries we can
+ * merge */
+ if ((r = transaction_merge_jobs(m)) >= 0)
+ break;
- /* Third step: do garbage colletion */
- transaction_collect_garbage(m);
+ if (r != -EAGAIN)
+ goto rollback;
+
+ /* Sixth step: an entry got dropped, let's garbage
+ * collect its dependencies. */
+ transaction_collect_garbage(m);
+
+ /* Let's see if the resulting transaction still has
+ * unmergeable entries ... */
+ }
- /* Fourth step: check whether we can actually apply this */
+ /* Seventh step: check whether we can actually apply this */
if (mode == JOB_FAIL)
if ((r = transaction_is_destructive(m, mode)) < 0)
goto rollback;
- /* Fifth step: apply changes */
+ /* Eights step: apply changes */
if ((r = transaction_apply(m, mode)) < 0)
goto rollback;
return r;
}
-static Job* transaction_add_one_job(Manager *m, JobType type, Name *name, bool *is_new) {
+static Job* transaction_add_one_job(Manager *m, JobType type, Name *name, bool force, bool *is_new) {
Job *j, *f;
int r;
j->generation = 0;
j->marker = NULL;
j->matters_to_anchor = false;
+ j->forced = force;
if (is_new)
*is_new = true;
return j;
}
-void manager_transaction_delete_job(Manager *m, Job *j) {
+void manager_transaction_unlink_job(Manager *m, Job *j) {
assert(m);
assert(j);
while (j->subject_list)
job_dependency_free(j->subject_list);
- while (j->object_list)
+
+ while (j->object_list) {
+ Job *other = j->object_list->matters ? j->object_list->subject : NULL;
+
job_dependency_free(j->object_list);
+
+ if (other) {
+ log_debug("Deleting job %s/%s as dependency of job %s/%s",
+ name_id(other->name), job_type_to_string(other->type),
+ name_id(j->name), job_type_to_string(j->type));
+ transaction_delete_job(m, other);
+ }
+ }
}
static int transaction_add_job_and_dependencies(Manager *m, JobType type, Name *name, Job *by, bool matters, bool force, Job **_ret) {
assert(type < _JOB_TYPE_MAX);
assert(name);
+ if (name->meta.load_state != NAME_LOADED)
+ return -EINVAL;
+
+ if (!job_type_is_applicable(type, name->meta.type))
+ return -EBADR;
+
/* First add the job. */
- if (!(ret = transaction_add_one_job(m, type, name, &is_new)))
+ if (!(ret = transaction_add_one_job(m, type, name, force, &is_new)))
return -ENOMEM;
/* Then, add a link to the job. */
/* Finally, recursively add in all dependencies. */
if (type == JOB_START || type == JOB_RELOAD_OR_START) {
SET_FOREACH(dep, ret->name->meta.dependencies[NAME_REQUIRES], state)
- if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, force, NULL)) < 0)
+ if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
goto fail;
SET_FOREACH(dep, ret->name->meta.dependencies[NAME_SOFT_REQUIRES], state)
- if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !force, force, NULL)) < 0)
+ if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
goto fail;
SET_FOREACH(dep, ret->name->meta.dependencies[NAME_WANTS], state)
- if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, force, NULL)) < 0)
+ if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, force, NULL)) < 0 && r != -EBADR)
goto fail;
SET_FOREACH(dep, ret->name->meta.dependencies[NAME_REQUISITE], state)
- if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_STARTED, dep, ret, true, force, NULL)) < 0)
+ if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
goto fail;
SET_FOREACH(dep, ret->name->meta.dependencies[NAME_SOFT_REQUISITE], state)
- if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_STARTED, dep, ret, !force, force, NULL)) < 0)
+ if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
goto fail;
SET_FOREACH(dep, ret->name->meta.dependencies[NAME_CONFLICTS], state)
- if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, force, NULL)) < 0)
+ if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
goto fail;
} else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
SET_FOREACH(dep, ret->name->meta.dependencies[NAME_REQUIRED_BY], state)
- if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, force, NULL)) < 0)
+ if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, force, NULL)) < 0 && r != -EBADR)
goto fail;
}
return -ENOMEM;
}
- if (set_put(ret->meta.names, n) < 0) {
+ if ((r = set_put(ret->meta.names, n)) < 0) {
name_free(ret);
free(n);
- return -ENOMEM;
+ return r;
}
if ((r = name_link(ret)) < 0) {
while ((j = hashmap_first(m->jobs)))
job_free(j);
}
+
+void manager_run_jobs(Manager *m) {
+ Job *j;
+ void *state;
+ int r;
+
+ HASHMAP_FOREACH(j, m->jobs, state) {
+ r = job_run_and_invalidate(j);
+ }
+}
~ianmdlvl / elogind.git / blobdiff