dbus: notify externals when reconfiguration completes

initctl reload freezes conditions to the old generation and each
owner re-asserts.  Finit's own providers do this in-process; an
external provider whose conditions are generation files, rather than
the oneshot symlinks keventd uses, has no way to know the moment.
Emit Manager1.ConfigReloaded when reconfiguration completes.

keventd needs no subscriber: its conditions are symlinks to the
reconf marker itself, so they read the current generation by
construction and never flux, which the device bus test now pins
down.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

doc/dbus.md

@@ -137,7 +137,7 @@ All read-only strings; observable via `Properties.Get` and
 |-----------------------|----------------------------------------|------------------------|
 | `ServiceStateChanged` | `sss` — identity, old state, new state | Service transitions    |
 | `RunlevelChanged`     | `ss`  — old level, new level           | System runlevel change |
-| `ConfigReloaded`      | —                                      | `initctl reload` completed; external condition providers re-assert |
+| `ConfigReloaded`      | —                                      | `initctl reload` completed; providers of generation-file conditions re-assert |
 
 State names emitted by `ServiceStateChanged` are stable wire strings:
 `halted`, `done`, `dead`, `cleanup`, `teardown`, `stopping`, `setup`,

src/dbus.c

@@ -626,6 +626,7 @@ static const link_method_t manager_methods[] = {
 static const link_signal_t manager_signals[] = {
 	{ .name = "ServiceStateChanged", .sig = "sss" },
 	{ .name = "RunlevelChanged",     .sig = "ss"  },
+	{ .name = "ConfigReloaded",      .sig = ""    },
 	{ NULL, NULL }
 };
 
@@ -1042,6 +1043,18 @@ void dbus_notify_runlevel_change(int old_level, int new_level)
 			 "RunlevelChanged", "ss", body, (size_t)blen);
 }
 
+/*
+ * Reconfiguration complete: all conditions have been re-asserted by
+ * their in-Finit owners.  External providers whose conditions are
+ * generation files, rather than the oneshot symlinks keventd uses,
+ * subscribe to this to re-assert theirs.
+ */
+void dbus_notify_reload(void)
+{
+	dbus_emit_signal("/org/finit/manager", "org.finit.Manager1",
+			 "ConfigReloaded", "", NULL, 0);
+}
+
 /* ---------- org.finit.Cond1 ---------- */
 
 #define COND_PATH_OBJECT "/org/finit/cond"

src/private.h

@@ -54,6 +54,7 @@ void         dbus_unregister_service   (svc_t *svc);
 void         dbus_notify_service_state (svc_t *svc, int old_state, int new_state);
 void         dbus_notify_condition_change(const char *name, const char *state);
 void         dbus_notify_runlevel_change(int old_level, int new_level);
+void         dbus_notify_reload         (void);
 #endif
 void         conf_flush_events(void);
 

src/sm.c

@@ -633,6 +633,9 @@ restart:
 		service_step_all(SVC_TYPE_ANY);
 
 		dbg("Reconfiguration done");
+#ifdef HAVE_DBUS
+		dbus_notify_reload();
+#endif
 		sm.state = SM_RUNNING_STATE;
 		break;
 	}

test/dbus-device.sh

@@ -133,3 +133,8 @@ case "$(cat /tmp/dbus-devauthz.out)" in
     *AccessDenied*) assert "Device1 authz fires" 0 -eq 0 ;;
     *) fail "Unexpected reply: $(cat /tmp/dbus-devauthz.out)" ;;
 esac
+
+say "Conditions are generation symlinks, unaffected by initctl reload"
+run "initctl reload"
+retry 'assert_cond "class/net/dummy0"'
+assert "class/net/dummy0 still asserted after reload" 0 -eq 0