Avoid reloading services when shutting down

Doing so won't work and makes no sense.  Thanks to Michael Stapelberg
for the patch.  Closes: #624599.

debian/changelog

@@ -3,6 +3,9 @@ systemd (44-5) UNRELEASED; urgency=low
   * disable killing on entering START_PRE, START, thanks to Michael
     Stapelberg for patch.  This avoids killing VMs run through libvirt
     when restarting libvirtd.  Closes: #688635.
+  * Avoid reloading services when shutting down, since that won't work and
+    makes no sense.  Thanks to Michael Stapelberg for the patch.
+    Closes: #624599.
 
  -- Tollef Fog Heen <tfheen@debian.org>  Tue, 16 Oct 2012 18:09:10 +0200
 

src/manager.c

@@ -1700,6 +1700,8 @@ static int transaction_add_isolate_jobs(Manager *m) {
 int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool override, DBusError *e, Job **_ret) {
         int r;
         Job *ret;
+        Job *j;
+        Iterator i;
 
         assert(m);
         assert(type < _JOB_TYPE_MAX);
@@ -1711,6 +1713,30 @@ int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool ove
                 return -EINVAL;
         }
 
+        if (type == JOB_RELOAD || type == JOB_RELOAD_OR_START || type == JOB_RESTART || type == JOB_TRY_RESTART) {
+                /* If final.target is queued (happens on poweroff, reboot and
+                 * halt), we will not accept new reload jobs. They would not be
+                 * executed ever anyways (since the shutdown comes first), but
+                 * they block the shutdown process: when systemd tries to stop
+                 * a unit such as ifup@eth0.service, that unit might invoke a
+                 * systemctl reload command, which blockingly waits (but only
+                 * gets executed after all other queued units for the shutdown
+                 * have been executed).
+                 *
+                 * See http://bugs.debian.org/624599 and
+                 *     http://bugs.debian.org/635777 */
+                HASHMAP_FOREACH(j, m->jobs, i) {
+                        assert(j->installed);
+
+                        if (strcmp(j->unit->id, "final.target") == 0) {
+                                log_debug("final.target is queued, ignoring %s request for unit %s", job_type_to_string(type), unit->id);
+                                dbus_set_error(e, BUS_ERROR_INVALID_JOB_MODE, "final.target is queued, ignoring %s request for unit %s", job_type_to_string(type), unit->id);
+                                return -EINVAL;
+                        }
+                }
+        }
+
+
         if (mode == JOB_ISOLATE && !unit->allow_isolate) {
                 dbus_set_error(e, BUS_ERROR_NO_ISOLATION, "Operation refused, unit may not be isolated.");
                 return -EPERM;