summaryrefslogtreecommitdiffstats
path: root/src/core/transaction.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/core/transaction.c')
-rw-r--r--src/core/transaction.c1119
1 files changed, 1119 insertions, 0 deletions
diff --git a/src/core/transaction.c b/src/core/transaction.c
new file mode 100644
index 0000000..2418332
--- /dev/null
+++ b/src/core/transaction.c
@@ -0,0 +1,1119 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "bus-common-errors.h"
+#include "bus-error.h"
+#include "terminal-util.h"
+#include "transaction.h"
+#include "dbus-unit.h"
+
+static void transaction_unlink_job(Transaction *tr, Job *j, bool delete_dependencies);
+
+static void transaction_delete_job(Transaction *tr, Job *j, bool delete_dependencies) {
+ assert(tr);
+ assert(j);
+
+ /* Deletes one job from the transaction */
+
+ transaction_unlink_job(tr, j, delete_dependencies);
+
+ job_free(j);
+}
+
+static void transaction_delete_unit(Transaction *tr, Unit *u) {
+ Job *j;
+
+ /* Deletes all jobs associated with a certain unit from the
+ * transaction */
+
+ while ((j = hashmap_get(tr->jobs, u)))
+ transaction_delete_job(tr, j, true);
+}
+
+void transaction_abort(Transaction *tr) {
+ Job *j;
+
+ assert(tr);
+
+ while ((j = hashmap_first(tr->jobs)))
+ transaction_delete_job(tr, j, false);
+
+ assert(hashmap_isempty(tr->jobs));
+}
+
+static void transaction_find_jobs_that_matter_to_anchor(Job *j, unsigned generation) {
+ JobDependency *l;
+
+ /* A recursive sweep through the graph that marks all units
+ * that matter to the anchor job, i.e. are directly or
+ * indirectly a dependency of the anchor job via paths that
+ * are fully marked as mattering. */
+
+ j->matters_to_anchor = true;
+ j->generation = generation;
+
+ LIST_FOREACH(subject, l, j->subject_list) {
+
+ /* This link does not matter */
+ if (!l->matters)
+ continue;
+
+ /* This unit has already been marked */
+ if (l->object->generation == generation)
+ continue;
+
+ transaction_find_jobs_that_matter_to_anchor(l->object, generation);
+ }
+}
+
+static void transaction_merge_and_delete_job(Transaction *tr, Job *j, Job *other, JobType t) {
+ JobDependency *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->irreversible = j->irreversible || other->irreversible;
+ j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
+
+ /* Patch us in as new owner of the JobDependency objects */
+ last = NULL;
+ LIST_FOREACH(subject, l, other->subject_list) {
+ assert(l->subject == other);
+ l->subject = j;
+ last = l;
+ }
+
+ /* Merge both lists */
+ if (last) {
+ last->subject_next = j->subject_list;
+ if (j->subject_list)
+ j->subject_list->subject_prev = last;
+ j->subject_list = other->subject_list;
+ }
+
+ /* Patch us in as new owner of the JobDependency objects */
+ last = NULL;
+ LIST_FOREACH(object, l, other->object_list) {
+ assert(l->object == other);
+ l->object = j;
+ last = l;
+ }
+
+ /* Merge both lists */
+ if (last) {
+ last->object_next = j->object_list;
+ if (j->object_list)
+ j->object_list->object_prev = last;
+ j->object_list = other->object_list;
+ }
+
+ /* Kill the other job */
+ other->subject_list = NULL;
+ other->object_list = NULL;
+ transaction_delete_job(tr, other, true);
+}
+
+_pure_ 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_unit_debug(j->unit,
+ "Looking at job %s/%s conflicted_by=%s",
+ j->unit->id, job_type_to_string(j->type),
+ yes_no(j->type == JOB_STOP && job_is_conflicted_by(j)));
+ log_unit_debug(k->unit,
+ "Looking at job %s/%s conflicted_by=%s",
+ k->unit->id, job_type_to_string(k->type),
+ yes_no(k->type == JOB_STOP && job_is_conflicted_by(k)));
+
+ if (j->type == JOB_STOP) {
+
+ if (job_is_conflicted_by(j))
+ d = k;
+ else
+ d = j;
+
+ } else if (k->type == JOB_STOP) {
+
+ if (job_is_conflicted_by(k))
+ d = j;
+ else
+ d = k;
+ } else
+ d = j;
+
+ } else if (!j->matters_to_anchor)
+ d = j;
+ else if (!k->matters_to_anchor)
+ d = k;
+ else
+ return -ENOEXEC;
+
+ /* Ok, we can drop one, so let's do so. */
+ log_unit_debug(d->unit,
+ "Fixing conflicting jobs %s/%s,%s/%s by deleting job %s/%s",
+ j->unit->id, job_type_to_string(j->type),
+ k->unit->id, job_type_to_string(k->type),
+ d->unit->id, job_type_to_string(d->type));
+ transaction_delete_job(tr, d, true);
+ return 0;
+ }
+
+ return -EINVAL;
+}
+
+static int transaction_merge_jobs(Transaction *tr, sd_bus_error *e) {
+ Job *j;
+ 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_and_collapse(&t, k->type, j->unit) >= 0)
+ continue;
+
+ /* OK, we could not merge all jobs for this
+ * action. Let's see if we can get rid of one
+ * of them */
+
+ r = delete_one_unmergeable_job(tr, j);
+ if (r >= 0)
+ /* Ok, we managed to drop one, now
+ * let's ask our callers to call us
+ * again after garbage collecting */
+ return -EAGAIN;
+
+ /* We couldn't merge anything. Failure */
+ return sd_bus_error_setf(e, BUS_ERROR_TRANSACTION_JOBS_CONFLICTING,
+ "Transaction contains conflicting jobs '%s' and '%s' for %s. "
+ "Probably contradicting requirement dependencies configured.",
+ job_type_to_string(t),
+ job_type_to_string(k->type),
+ k->unit->id);
+ }
+ }
+
+ /* Second step, merge the jobs. */
+ HASHMAP_FOREACH(j, tr->jobs, i) {
+ JobType t = j->type;
+ Job *k;
+
+ /* Merge all transaction jobs for j->unit */
+ LIST_FOREACH(transaction, k, j->transaction_next)
+ assert_se(job_type_merge_and_collapse(&t, k->type, j->unit) == 0);
+
+ while ((k = j->transaction_next)) {
+ if (tr->anchor_job == k) {
+ transaction_merge_and_delete_job(tr, k, j, t);
+ j = k;
+ } else
+ transaction_merge_and_delete_job(tr, j, k, t);
+ }
+
+ assert(!j->transaction_next);
+ assert(!j->transaction_prev);
+ }
+
+ return 0;
+}
+
+static void transaction_drop_redundant(Transaction *tr) {
+ Job *j;
+ Iterator i;
+
+ /* Goes through the transaction and removes all jobs of the units
+ * whose jobs are all noops. If not all of a unit's jobs are
+ * redundant, they are kept. */
+
+ assert(tr);
+
+rescan:
+ HASHMAP_FOREACH(j, tr->jobs, i) {
+ Job *k;
+
+ LIST_FOREACH(transaction, k, j) {
+
+ if (tr->anchor_job == k ||
+ !job_type_is_redundant(k->type, unit_active_state(k->unit)) ||
+ (k->unit->job && job_type_is_conflicting(k->type, k->unit->job->type)))
+ goto next_unit;
+ }
+
+ log_trace("Found redundant job %s/%s, dropping from transaction.", j->unit->id, job_type_to_string(j->type));
+ transaction_delete_job(tr, j, false);
+ goto rescan;
+ next_unit:;
+ }
+}
+
+_pure_ 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 char* merge_unit_ids(const char* unit_log_field, char **pairs) {
+ char **unit_id, **job_type, *ans = NULL;
+ size_t alloc = 0, size = 0, next;
+
+ STRV_FOREACH_PAIR(unit_id, job_type, pairs) {
+ next = strlen(unit_log_field) + strlen(*unit_id);
+ if (!GREEDY_REALLOC(ans, alloc, size + next + 1)) {
+ return mfree(ans);
+ }
+
+ sprintf(ans + size, "%s%s", unit_log_field, *unit_id);
+ if (*(unit_id+1))
+ ans[size + next] = '\n';
+ size += next + 1;
+ }
+
+ return ans;
+}
+
+static int transaction_verify_order_one(Transaction *tr, Job *j, Job *from, unsigned generation, sd_bus_error *e) {
+ Iterator i;
+ Unit *u;
+ void *v;
+ int r;
+
+ assert(tr);
+ assert(j);
+ assert(!j->transaction_prev);
+
+ /* Does a recursive sweep through the ordering graph, looking
+ * for a cycle. If we find a cycle we try to break it. */
+
+ /* Have we seen this before? */
+ if (j->generation == generation) {
+ Job *k, *delete = NULL;
+ _cleanup_free_ char **array = NULL, *unit_ids = NULL;
+ char **unit_id, **job_type;
+
+ /* If the marker is NULL we have been here already and
+ * decided the job was loop-free from here. Hence
+ * shortcut things and return right-away. */
+ if (!j->marker)
+ return 0;
+
+ /* So, the marker is not NULL and we already have been here. We have
+ * a cycle. Let's try to break it. We go backwards in our path and
+ * try to find a suitable job to remove. We use the marker to find
+ * our way back, since smart how we are we stored our way back in
+ * there. */
+
+ for (k = from; k; k = ((k->generation == generation && k->marker != k) ? k->marker : NULL)) {
+
+ /* For logging below */
+ if (strv_push_pair(&array, k->unit->id, (char*) job_type_to_string(k->type)) < 0)
+ log_oom();
+
+ if (!delete && hashmap_get(tr->jobs, k->unit) && !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;
+ }
+
+ unit_ids = merge_unit_ids(j->manager->unit_log_field, array); /* ignore error */
+
+ STRV_FOREACH_PAIR(unit_id, job_type, array)
+ /* logging for j not k here to provide a consistent narrative */
+ log_struct(LOG_WARNING,
+ "MESSAGE=%s: Found %s on %s/%s",
+ j->unit->id,
+ unit_id == array ? "ordering cycle" : "dependency",
+ *unit_id, *job_type,
+ unit_ids);
+
+ if (delete) {
+ const char *status;
+ /* logging for j not k here to provide a consistent narrative */
+ log_struct(LOG_ERR,
+ "MESSAGE=%s: Job %s/%s deleted to break ordering cycle starting with %s/%s",
+ j->unit->id, delete->unit->id, job_type_to_string(delete->type),
+ j->unit->id, job_type_to_string(j->type),
+ unit_ids);
+
+ if (log_get_show_color())
+ status = ANSI_HIGHLIGHT_RED " SKIP " ANSI_NORMAL;
+ else
+ status = " SKIP ";
+
+ unit_status_printf(delete->unit, status,
+ "Ordering cycle found, skipping %s");
+ transaction_delete_unit(tr, delete->unit);
+ return -EAGAIN;
+ }
+
+ log_struct(LOG_ERR,
+ "MESSAGE=%s: Unable to break cycle starting with %s/%s",
+ j->unit->id, j->unit->id, job_type_to_string(j->type),
+ unit_ids);
+
+ return sd_bus_error_setf(e, BUS_ERROR_TRANSACTION_ORDER_IS_CYCLIC,
+ "Transaction order is cyclic. See system logs for details.");
+ }
+
+ /* Make the marker point to where we come from, so that we can
+ * find our way backwards if we want to break a cycle. We use
+ * a special marker for the beginning: we point to
+ * ourselves. */
+ j->marker = from ? from : j;
+ j->generation = generation;
+
+ /* We assume that the dependencies are bidirectional, and
+ * hence can ignore UNIT_AFTER */
+ HASHMAP_FOREACH_KEY(v, 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, sd_bus_error *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) {
+ r = transaction_verify_order_one(tr, j, NULL, g, e);
+ if (r < 0)
+ return r;
+ }
+
+ return 0;
+}
+
+static void transaction_collect_garbage(Transaction *tr) {
+ Iterator i;
+ Job *j;
+
+ assert(tr);
+
+ /* Drop jobs that are not required by any other job */
+
+rescan:
+ HASHMAP_FOREACH(j, tr->jobs, i) {
+ if (tr->anchor_job == j)
+ continue;
+ if (j->object_list) {
+ log_trace("Keeping job %s/%s because of %s/%s",
+ j->unit->id, job_type_to_string(j->type),
+ j->object_list->subject ? j->object_list->subject->unit->id : "root",
+ j->object_list->subject ? job_type_to_string(j->object_list->subject->type) : "root");
+ continue;
+ }
+
+ log_trace("Garbage collecting job %s/%s", j->unit->id, job_type_to_string(j->type));
+ transaction_delete_job(tr, j, true);
+ goto rescan;
+ }
+}
+
+static int transaction_is_destructive(Transaction *tr, JobMode mode, sd_bus_error *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 && (mode == JOB_FAIL || j->unit->job->irreversible) &&
+ job_type_is_conflicting(j->unit->job->type, j->type))
+ return sd_bus_error_setf(e, BUS_ERROR_TRANSACTION_IS_DESTRUCTIVE,
+ "Transaction for %s/%s is destructive (%s has '%s' job queued, but '%s' is included in transaction).",
+ tr->anchor_job->unit->id, job_type_to_string(tr->anchor_job->type),
+ j->unit->id, job_type_to_string(j->unit->job->type), job_type_to_string(j->type));
+ }
+
+ return 0;
+}
+
+static void transaction_minimize_impact(Transaction *tr) {
+ Job *j;
+ Iterator i;
+
+ assert(tr);
+
+ /* Drops all unnecessary jobs that reverse already active jobs
+ * or that stop a running service. */
+
+rescan:
+ 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_unit_debug(j->unit,
+ "%s/%s would stop a running service.",
+ j->unit->id, job_type_to_string(j->type));
+
+ if (changes_existing_job)
+ log_unit_debug(j->unit,
+ "%s/%s would change existing job.",
+ j->unit->id, job_type_to_string(j->type));
+
+ /* Ok, let's get rid of this */
+ log_unit_debug(j->unit,
+ "Deleting %s/%s to minimize impact.",
+ j->unit->id, job_type_to_string(j->type));
+
+ transaction_delete_job(tr, j, true);
+ goto rescan;
+ }
+ }
+}
+
+static int transaction_apply(Transaction *tr, Manager *m, JobMode mode) {
+ Iterator i;
+ Job *j;
+ int r;
+
+ /* Moves the transaction jobs to the set of active jobs */
+
+ if (IN_SET(mode, JOB_ISOLATE, JOB_FLUSH)) {
+
+ /* When isolating first kill all installed jobs which
+ * aren't part of the new transaction */
+ HASHMAP_FOREACH(j, m->jobs, i) {
+ assert(j->installed);
+
+ if (j->unit->ignore_on_isolate)
+ continue;
+
+ if (hashmap_get(tr->jobs, j->unit))
+ continue;
+
+ /* Not invalidating recursively. Avoids triggering
+ * OnFailure= actions of dependent jobs. Also avoids
+ * invalidating our iterator. */
+ job_finish_and_invalidate(j, JOB_CANCELED, false, false);
+ }
+ }
+
+ HASHMAP_FOREACH(j, tr->jobs, i) {
+ /* Assume merged */
+ assert(!j->transaction_prev);
+ assert(!j->transaction_next);
+
+ r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j);
+ if (r < 0)
+ goto rollback;
+ }
+
+ while ((j = hashmap_steal_first(tr->jobs))) {
+ Job *installed_job;
+
+ /* Clean the job dependencies */
+ transaction_unlink_job(tr, j, false);
+
+ installed_job = job_install(j);
+ if (installed_job != j) {
+ /* j has been merged into a previously installed job */
+ if (tr->anchor_job == j)
+ tr->anchor_job = installed_job;
+ hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
+ job_free(j);
+ j = installed_job;
+ }
+
+ job_add_to_run_queue(j);
+ job_add_to_dbus_queue(j);
+ job_start_timer(j, false);
+ job_shutdown_magic(j);
+ }
+
+ return 0;
+
+rollback:
+
+ HASHMAP_FOREACH(j, tr->jobs, i)
+ hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
+
+ return r;
+}
+
+int transaction_activate(Transaction *tr, Manager *m, JobMode mode, sd_bus_error *e) {
+ Iterator i;
+ Job *j;
+ int r;
+ unsigned generation = 1;
+
+ assert(tr);
+
+ /* This applies the changes recorded in tr->jobs to
+ * the actual list of jobs, if possible. */
+
+ /* Reset the generation counter of all installed jobs. The detection of cycles
+ * looks at installed jobs. If they had a non-zero generation from some previous
+ * walk of the graph, the algorithm would break. */
+ HASHMAP_FOREACH(j, m->jobs, i)
+ j->generation = 0;
+
+ /* First step: figure out which jobs matter */
+ transaction_find_jobs_that_matter_to_anchor(tr->anchor_job, generation++);
+
+ /* Second step: Try not to stop any running services if
+ * we don't have to. Don't try to reverse running
+ * jobs if we don't have to. */
+ if (mode == JOB_FAIL)
+ transaction_minimize_impact(tr);
+
+ /* Third step: Drop redundant jobs */
+ transaction_drop_redundant(tr);
+
+ for (;;) {
+ /* Fourth step: Let's remove unneeded jobs that might
+ * be lurking. */
+ if (mode != JOB_ISOLATE)
+ transaction_collect_garbage(tr);
+
+ /* Fifth step: verify order makes sense and correct
+ * cycles if necessary and possible */
+ r = transaction_verify_order(tr, &generation, e);
+ if (r >= 0)
+ break;
+
+ if (r != -EAGAIN)
+ return log_warning_errno(r, "Requested transaction contains an unfixable cyclic ordering dependency: %s", bus_error_message(e, r));
+
+ /* Let's see if the resulting transaction ordering
+ * graph is still cyclic... */
+ }
+
+ for (;;) {
+ /* Sixth step: let's drop unmergeable entries if
+ * necessary and possible, merge entries we can
+ * merge */
+ r = transaction_merge_jobs(tr, e);
+ if (r >= 0)
+ break;
+
+ if (r != -EAGAIN)
+ return log_warning_errno(r, "Requested transaction contains unmergeable jobs: %s", bus_error_message(e, r));
+
+ /* Seventh step: an entry got dropped, let's garbage
+ * collect its dependencies. */
+ if (mode != JOB_ISOLATE)
+ transaction_collect_garbage(tr);
+
+ /* Let's see if the resulting transaction still has
+ * unmergeable entries ... */
+ }
+
+ /* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */
+ transaction_drop_redundant(tr);
+
+ /* Ninth step: check whether we can actually apply this */
+ r = transaction_is_destructive(tr, mode, e);
+ if (r < 0)
+ return log_notice_errno(r, "Requested transaction contradicts existing jobs: %s", bus_error_message(e, r));
+
+ /* Tenth step: apply changes */
+ r = transaction_apply(tr, m, mode);
+ if (r < 0)
+ return log_warning_errno(r, "Failed to apply transaction: %m");
+
+ assert(hashmap_isempty(tr->jobs));
+
+ if (!hashmap_isempty(m->jobs)) {
+ /* Are there any jobs now? Then make sure we have the
+ * idle pipe around. We don't really care too much
+ * whether this works or not, as the idle pipe is a
+ * feature for cosmetics, not actually useful for
+ * anything beyond that. */
+
+ if (m->idle_pipe[0] < 0 && m->idle_pipe[1] < 0 &&
+ m->idle_pipe[2] < 0 && m->idle_pipe[3] < 0) {
+ (void) pipe2(m->idle_pipe, O_NONBLOCK|O_CLOEXEC);
+ (void) pipe2(m->idle_pipe + 2, O_NONBLOCK|O_CLOEXEC);
+ }
+ }
+
+ return 0;
+}
+
+static Job* transaction_add_one_job(Transaction *tr, JobType type, Unit *unit, bool *is_new) {
+ Job *j, *f;
+
+ assert(tr);
+ assert(unit);
+
+ /* Looks for an existing prospective job and returns that. If
+ * it doesn't exist it is created and added to the prospective
+ * jobs list. */
+
+ f = hashmap_get(tr->jobs, unit);
+
+ LIST_FOREACH(transaction, j, f) {
+ assert(j->unit == unit);
+
+ if (j->type == type) {
+ if (is_new)
+ *is_new = false;
+ return j;
+ }
+ }
+
+ j = job_new(unit, type);
+ if (!j)
+ return NULL;
+
+ j->generation = 0;
+ j->marker = NULL;
+ j->matters_to_anchor = false;
+ j->irreversible = tr->irreversible;
+
+ LIST_PREPEND(transaction, f, j);
+
+ if (hashmap_replace(tr->jobs, unit, f) < 0) {
+ LIST_REMOVE(transaction, f, j);
+ job_free(j);
+ return NULL;
+ }
+
+ if (is_new)
+ *is_new = true;
+
+ log_trace("Added job %s/%s to transaction.", unit->id, job_type_to_string(type));
+
+ return j;
+}
+
+static void transaction_unlink_job(Transaction *tr, Job *j, bool delete_dependencies) {
+ assert(tr);
+ assert(j);
+
+ if (j->transaction_prev)
+ j->transaction_prev->transaction_next = j->transaction_next;
+ else if (j->transaction_next)
+ hashmap_replace(tr->jobs, j->unit, j->transaction_next);
+ else
+ hashmap_remove_value(tr->jobs, j->unit, j);
+
+ if (j->transaction_next)
+ j->transaction_next->transaction_prev = j->transaction_prev;
+
+ j->transaction_prev = j->transaction_next = NULL;
+
+ while (j->subject_list)
+ job_dependency_free(j->subject_list);
+
+ while (j->object_list) {
+ Job *other = j->object_list->matters ? j->object_list->subject : NULL;
+
+ job_dependency_free(j->object_list);
+
+ if (other && delete_dependencies) {
+ log_unit_debug(other->unit,
+ "Deleting job %s/%s as dependency of job %s/%s",
+ other->unit->id, job_type_to_string(other->type),
+ j->unit->id, job_type_to_string(j->type));
+ transaction_delete_job(tr, other, delete_dependencies);
+ }
+ }
+}
+
+void transaction_add_propagate_reload_jobs(Transaction *tr, Unit *unit, Job *by, bool ignore_order, sd_bus_error *e) {
+ Iterator i;
+ JobType nt;
+ Unit *dep;
+ void *v;
+ int r;
+
+ assert(tr);
+ assert(unit);
+
+ HASHMAP_FOREACH_KEY(v, dep, unit->dependencies[UNIT_PROPAGATES_RELOAD_TO], i) {
+ nt = job_type_collapse(JOB_TRY_RELOAD, dep);
+ if (nt == JOB_NOP)
+ continue;
+
+ r = transaction_add_job_and_dependencies(tr, nt, dep, by, false, false, false, ignore_order, e);
+ if (r < 0) {
+ log_unit_warning(dep,
+ "Cannot add dependency reload job, ignoring: %s",
+ bus_error_message(e, r));
+ sd_bus_error_free(e);
+ }
+ }
+}
+
+int transaction_add_job_and_dependencies(
+ Transaction *tr,
+ JobType type,
+ Unit *unit,
+ Job *by,
+ bool matters,
+ bool conflicts,
+ bool ignore_requirements,
+ bool ignore_order,
+ sd_bus_error *e) {
+
+ bool is_new;
+ Iterator i;
+ Unit *dep;
+ Job *ret;
+ void *v;
+ int r;
+
+ assert(tr);
+ assert(type < _JOB_TYPE_MAX);
+ assert(type < _JOB_TYPE_MAX_IN_TRANSACTION);
+ assert(unit);
+
+ /* Before adding jobs for this unit, let's ensure that its state has been loaded
+ * This matters when jobs are spawned as part of coldplugging itself (see e. g. path_coldplug()).
+ * This way, we "recursively" coldplug units, ensuring that we do not look at state of
+ * not-yet-coldplugged units. */
+ if (MANAGER_IS_RELOADING(unit->manager))
+ unit_coldplug(unit);
+
+ if (by)
+ log_trace("Pulling in %s/%s from %s/%s", unit->id, job_type_to_string(type), by->unit->id, job_type_to_string(by->type));
+
+ /* Safety check that the unit is a valid state, i.e. not in UNIT_STUB or UNIT_MERGED which should only be set
+ * temporarily. */
+ if (!IN_SET(unit->load_state, UNIT_LOADED, UNIT_ERROR, UNIT_NOT_FOUND, UNIT_BAD_SETTING, UNIT_MASKED))
+ return sd_bus_error_setf(e, BUS_ERROR_LOAD_FAILED, "Unit %s is not loaded properly.", unit->id);
+
+ if (type != JOB_STOP) {
+ r = bus_unit_validate_load_state(unit, e);
+ if (r < 0)
+ return r;
+ }
+
+ if (!unit_job_is_applicable(unit, type))
+ return sd_bus_error_setf(e, BUS_ERROR_JOB_TYPE_NOT_APPLICABLE,
+ "Job type %s is not applicable for unit %s.",
+ job_type_to_string(type), unit->id);
+
+ /* First add the job. */
+ ret = transaction_add_one_job(tr, type, unit, &is_new);
+ if (!ret)
+ return -ENOMEM;
+
+ ret->ignore_order = ret->ignore_order || ignore_order;
+
+ /* Then, add a link to the job. */
+ if (by) {
+ if (!job_dependency_new(by, ret, matters, conflicts))
+ return -ENOMEM;
+ } else {
+ /* If the job has no parent job, it is the anchor job. */
+ assert(!tr->anchor_job);
+ tr->anchor_job = ret;
+ }
+
+ if (is_new && !ignore_requirements && type != JOB_NOP) {
+ 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, false, false, ignore_order, e);
+ if (r < 0) {
+ log_unit_full(dep,
+ r == -ERFKILL ? LOG_INFO : LOG_WARNING,
+ r, "Cannot add dependency job, ignoring: %s",
+ bus_error_message(e, r));
+ sd_bus_error_free(e);
+ }
+ }
+
+ set_free(following);
+ }
+
+ /* Finally, recursively add in all dependencies. */
+ if (IN_SET(type, JOB_START, JOB_RESTART)) {
+ HASHMAP_FOREACH_KEY(v, dep, ret->unit->dependencies[UNIT_REQUIRES], i) {
+ r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, true, false, false, ignore_order, e);
+ if (r < 0) {
+ if (r != -EBADR) /* job type not applicable */
+ goto fail;
+
+ sd_bus_error_free(e);
+ }
+ }
+
+ HASHMAP_FOREACH_KEY(v, dep, ret->unit->dependencies[UNIT_BINDS_TO], i) {
+ r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, true, false, false, ignore_order, e);
+ if (r < 0) {
+ if (r != -EBADR) /* job type not applicable */
+ goto fail;
+
+ sd_bus_error_free(e);
+ }
+ }
+
+ HASHMAP_FOREACH_KEY(v, dep, ret->unit->dependencies[UNIT_WANTS], i) {
+ r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, false, false, false, ignore_order, e);
+ if (r < 0) {
+ /* unit masked, job type not applicable and unit not found are not considered as errors. */
+ log_unit_full(dep,
+ IN_SET(r, -ERFKILL, -EBADR, -ENOENT) ? LOG_DEBUG : LOG_WARNING,
+ r, "Cannot add dependency job, ignoring: %s",
+ bus_error_message(e, r));
+ sd_bus_error_free(e);
+ }
+ }
+
+ HASHMAP_FOREACH_KEY(v, dep, ret->unit->dependencies[UNIT_REQUISITE], i) {
+ r = transaction_add_job_and_dependencies(tr, JOB_VERIFY_ACTIVE, dep, ret, true, false, false, ignore_order, e);
+ if (r < 0) {
+ if (r != -EBADR) /* job type not applicable */
+ goto fail;
+
+ sd_bus_error_free(e);
+ }
+ }
+
+ HASHMAP_FOREACH_KEY(v, dep, ret->unit->dependencies[UNIT_CONFLICTS], i) {
+ r = transaction_add_job_and_dependencies(tr, JOB_STOP, dep, ret, true, true, false, ignore_order, e);
+ if (r < 0) {
+ if (r != -EBADR) /* job type not applicable */
+ goto fail;
+
+ sd_bus_error_free(e);
+ }
+ }
+
+ HASHMAP_FOREACH_KEY(v, dep, ret->unit->dependencies[UNIT_CONFLICTED_BY], i) {
+ r = transaction_add_job_and_dependencies(tr, JOB_STOP, dep, ret, false, false, false, ignore_order, e);
+ if (r < 0) {
+ log_unit_warning(dep,
+ "Cannot add dependency job, ignoring: %s",
+ bus_error_message(e, r));
+ sd_bus_error_free(e);
+ }
+ }
+
+ }
+
+ if (IN_SET(type, JOB_STOP, JOB_RESTART)) {
+ static const UnitDependency propagate_deps[] = {
+ UNIT_REQUIRED_BY,
+ UNIT_REQUISITE_OF,
+ UNIT_BOUND_BY,
+ UNIT_CONSISTS_OF,
+ };
+
+ JobType ptype;
+ unsigned j;
+
+ /* We propagate STOP as STOP, but RESTART only
+ * as TRY_RESTART, in order not to start
+ * dependencies that are not around. */
+ ptype = type == JOB_RESTART ? JOB_TRY_RESTART : type;
+
+ for (j = 0; j < ELEMENTSOF(propagate_deps); j++)
+ HASHMAP_FOREACH_KEY(v, dep, ret->unit->dependencies[propagate_deps[j]], i) {
+ JobType nt;
+
+ nt = job_type_collapse(ptype, dep);
+ if (nt == JOB_NOP)
+ continue;
+
+ r = transaction_add_job_and_dependencies(tr, nt, dep, ret, true, false, false, ignore_order, e);
+ if (r < 0) {
+ if (r != -EBADR) /* job type not applicable */
+ goto fail;
+
+ sd_bus_error_free(e);
+ }
+ }
+ }
+
+ if (type == JOB_RELOAD)
+ transaction_add_propagate_reload_jobs(tr, ret->unit, ret, ignore_order, e);
+
+ /* JOB_VERIFY_ACTIVE requires no dependency handling */
+ }
+
+ 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, tr->anchor_job, true, false, false, false, NULL);
+ if (r < 0)
+ log_unit_warning_errno(u, r, "Cannot add isolate job, ignoring: %m");
+ }
+
+ return 0;
+}
+
+Transaction *transaction_new(bool irreversible) {
+ Transaction *tr;
+
+ tr = new0(Transaction, 1);
+ if (!tr)
+ return NULL;
+
+ tr->jobs = hashmap_new(NULL);
+ if (!tr->jobs)
+ return mfree(tr);
+
+ tr->irreversible = irreversible;
+
+ return tr;
+}
+
+void transaction_free(Transaction *tr) {
+ assert(hashmap_isempty(tr->jobs));
+ hashmap_free(tr->jobs);
+ free(tr);
+}