core: make the StartLimitXYZ= settings generic and apply to any kind of unit, not just services

This moves the StartLimitBurst=, StartLimitInterval=, StartLimitAction=, RebootArgument= from the [Service] section
into the [Unit] section of unit files, and thus support it in all unit types, not just in services.

This way we can enforce the start limit much earlier, in particular before testing the unit conditions, so that
repeated start-up failure due to failed conditions is also considered for the start limit logic.

For compatibility the four options may also be configured in the [Service] section still, but we only document them in
their new section [Unit].

This also renamed the socket unit failure code "service-failed-permanent" into "service-start-limit-hit" to express
more clearly what it is about, after all it's only triggered through the start limit being hit.

Finally, the code in busname_trigger_notify() and socket_trigger_notify() is altered to become more alike.

Fixes: #2467

1 files changed, 13 insertions, 34 deletions

diff --git a/src/core/socket.c b/src/core/socket.c
index f0d65577e3..1f24f289e0 100644
--- a/src/core/socket.c
+++ b/src/core/socket.c
@@ -2702,23 +2702,6 @@ static void socket_reset_failed(Unit *u) {
         s->result = SOCKET_SUCCESS;
 }
 
-static void socket_notify_service_dead(Socket *s, bool failed_permanent) {
-        assert(s);
-
-        /* The service is dead. Dang!
-         *
-         * This is strictly for one-instance-for-all-connections
-         * services. */
-
-        if (s->state == SOCKET_RUNNING) {
-                log_unit_debug(UNIT(s), "Got notified about service death (failed permanently: %s)", yes_no(failed_permanent));
-                if (failed_permanent)
-                        socket_enter_stop_pre(s, SOCKET_FAILURE_SERVICE_FAILED_PERMANENT);
-                else
-                        socket_enter_listening(s);
-        }
-}
-
 void socket_connection_unref(Socket *s) {
         assert(s);
 
@@ -2735,34 +2718,30 @@ void socket_connection_unref(Socket *s) {
 
 static void socket_trigger_notify(Unit *u, Unit *other) {
         Socket *s = SOCKET(u);
-        Service *se;
 
         assert(u);
         assert(other);
 
         /* Don't propagate state changes from the service if we are
            already down or accepting connections */
-        if ((s->state != SOCKET_RUNNING &&
-            s->state != SOCKET_LISTENING) ||
-            s->accept)
+        if (!IN_SET(s->state, SOCKET_RUNNING, SOCKET_LISTENING) || s->accept)
                 return;
 
-        if (other->load_state != UNIT_LOADED ||
-            other->type != UNIT_SERVICE)
+        if (other->start_limit_hit) {
+                socket_enter_stop_pre(s, SOCKET_FAILURE_SERVICE_START_LIMIT_HIT);
                 return;
+        }
 
-        se = SERVICE(other);
-
-        if (se->state == SERVICE_FAILED)
-                socket_notify_service_dead(s, se->result == SERVICE_FAILURE_START_LIMIT);
+        if (other->load_state != UNIT_LOADED || other->type != UNIT_SERVICE)
+                return;
 
-        if (se->state == SERVICE_DEAD ||
-            se->state == SERVICE_FINAL_SIGTERM ||
-            se->state == SERVICE_FINAL_SIGKILL ||
-            se->state == SERVICE_AUTO_RESTART)
-                socket_notify_service_dead(s, false);
+        if (IN_SET(SERVICE(other)->state,
+                   SERVICE_DEAD, SERVICE_FAILED,
+                   SERVICE_FINAL_SIGTERM, SERVICE_FINAL_SIGKILL,
+                   SERVICE_AUTO_RESTART))
+               socket_enter_listening(s);
 
-        if (se->state == SERVICE_RUNNING)
+        if (SERVICE(other)->state == SERVICE_RUNNING)
                 socket_set_state(s, SOCKET_RUNNING);
 }
 
@@ -2818,7 +2797,7 @@ static const char* const socket_result_table[_SOCKET_RESULT_MAX] = {
         [SOCKET_FAILURE_EXIT_CODE] = "exit-code",
         [SOCKET_FAILURE_SIGNAL] = "signal",
         [SOCKET_FAILURE_CORE_DUMP] = "core-dump",
-        [SOCKET_FAILURE_SERVICE_FAILED_PERMANENT] = "service-failed-permanent"
+        [SOCKET_FAILURE_SERVICE_START_LIMIT_HIT] = "service-start-limit-hit"
 };
 
 DEFINE_STRING_TABLE_LOOKUP(socket_result, SocketResult);