machined: rework state tracking logic for machines

This splits up the stopping logic for machines into two steps: first on
machine_stop() we begin with the shutdown of a machine by queuing the
stop method call for it. Then, in machine_finalize() we actually remove
the rest of its runtime context. This mimics closely how sessions are
handled in logind.

This also reworks the GC logic to strictly check the current state of
the machine unit, rather than shortcutting a few cases, like for example
assuming that UnitRemoved really means a machine is gone (which it isn't
since Reloading might trigger it, see #376).

Fixes #376.

1 files changed, 4 insertions, 35 deletions

diff --git a/src/machine/machined-dbus.c b/src/machine/machined-dbus.c
index 49f41c62d7..08a7f58ef5 100644
--- a/src/machine/machined-dbus.c
+++ b/src/machine/machined-dbus.c
@@ -1136,8 +1136,9 @@ int match_job_removed(sd_bus_message *message, void *userdata, sd_bus_error *err
 
                                 machine_send_create_reply(machine, &e);
                         }
-                } else
-                        machine_save(machine);
+                }
+
+                machine_save(machine);
         }
 
         machine_add_to_gc_queue(machine);
@@ -1146,7 +1147,7 @@ int match_job_removed(sd_bus_message *message, void *userdata, sd_bus_error *err
 
 int match_properties_changed(sd_bus_message *message, void *userdata, sd_bus_error *error) {
         _cleanup_free_ char *unit = NULL;
-        const char *path, *interface;
+        const char *path;
         Manager *m = userdata;
         Machine *machine;
         int r;
@@ -1170,36 +1171,6 @@ int match_properties_changed(sd_bus_message *message, void *userdata, sd_bus_err
         if (!machine)
                 return 0;
 
-        r = sd_bus_message_read(message, "s", &interface);
-        if (r < 0) {
-                bus_log_parse_error(r);
-                return 0;
-        }
-
-        if (streq(interface, "org.freedesktop.systemd1.Unit")) {
-                struct properties {
-                        char *active_state;
-                        char *sub_state;
-                } properties = {};
-
-                const struct bus_properties_map map[] = {
-                        { "ActiveState", "s", NULL, offsetof(struct properties, active_state) },
-                        { "SubState",    "s", NULL, offsetof(struct properties, sub_state)    },
-                        {}
-                };
-
-                r = bus_message_map_properties_changed(message, map, &properties);
-                if (r < 0)
-                        bus_log_parse_error(r);
-                else if (streq_ptr(properties.active_state, "inactive") ||
-                         streq_ptr(properties.active_state, "failed") ||
-                         streq_ptr(properties.sub_state, "auto-restart"))
-                        machine_release_unit(machine);
-
-                free(properties.active_state);
-                free(properties.sub_state);
-        }
-
         machine_add_to_gc_queue(machine);
         return 0;
 }
@@ -1223,9 +1194,7 @@ int match_unit_removed(sd_bus_message *message, void *userdata, sd_bus_error *er
         if (!machine)
                 return 0;
 
-        machine_release_unit(machine);
         machine_add_to_gc_queue(machine);
-
         return 0;
 }