From: Ronan Pigott Date: Thu, 28 Nov 2024 19:53:32 +0000 (-0700) Subject: dbus: stash the subscriber list when we disconenct from the bus X-Git-Tag: v258-rc1~1651^2~1 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8402ca04d1a063c3d8a9e3d5c16df8bb8778ae98;p=thirdparty%2Fsystemd.git dbus: stash the subscriber list when we disconenct from the bus If we unexpectly disconnect from the bus, systemd would end up dropping the list of subscribers, which breaks the ability of clients like logind to monitor the state of units. Stash the list of subscribers into the deserialized state in the event of a disconnect so that when we recover we can renew the broken subscriptions. --- diff --git a/src/core/dbus.c b/src/core/dbus.c index 3f0f40e702b..9abc35888d0 100644 --- a/src/core/dbus.c +++ b/src/core/dbus.c @@ -860,6 +860,8 @@ int bus_init_api(Manager *m) { if (r < 0) return log_error_errno(r, "Failed to set up API bus: %m"); + (void) bus_track_coldplug(bus, &m->subscribed, /* recursive= */ false, m->deserialized_subscribed); + m->deserialized_subscribed = strv_free(m->deserialized_subscribed); m->api_bus = TAKE_PTR(bus); return 0; @@ -1004,8 +1006,17 @@ static void destroy_bus(Manager *m, sd_bus **bus) { } /* Get rid of tracked clients on this bus */ - if (m->subscribed && sd_bus_track_get_bus(m->subscribed) == *bus) + if (m->subscribed && sd_bus_track_get_bus(m->subscribed) == *bus) { + _cleanup_strv_free_ char **subscribed = NULL; + int r; + + r = bus_track_to_strv(m->subscribed, &subscribed); + if (r < 0) + log_warning_errno(r, "Failed to serialize api subscribers, ignoring: %m"); + strv_free_and_replace(m->deserialized_subscribed, subscribed); + m->subscribed = sd_bus_track_unref(m->subscribed); + } HASHMAP_FOREACH(j, m->jobs) if (j->bus_track && sd_bus_track_get_bus(j->bus_track) == *bus) @@ -1064,7 +1075,6 @@ void bus_done(Manager *m) { assert(!m->subscribed); - m->deserialized_subscribed = strv_free(m->deserialized_subscribed); m->polkit_registry = hashmap_free(m->polkit_registry); } @@ -1153,20 +1163,19 @@ void bus_track_serialize(sd_bus_track *t, FILE *f, const char *prefix) { } } -int bus_track_coldplug(Manager *m, sd_bus_track **t, bool recursive, char **l) { +int bus_track_coldplug(sd_bus *bus, sd_bus_track **t, bool recursive, char **l) { int r; - assert(m); assert(t); if (strv_isempty(l)) return 0; - if (!m->api_bus) + if (!bus) return 0; if (!*t) { - r = sd_bus_track_new(m->api_bus, t, NULL, NULL); + r = sd_bus_track_new(bus, t, NULL, NULL); if (r < 0) return r; } diff --git a/src/core/dbus.h b/src/core/dbus.h index d00c14d3b72..eb1baf60493 100644 --- a/src/core/dbus.h +++ b/src/core/dbus.h @@ -19,7 +19,7 @@ void bus_done(Manager *m); int bus_fdset_add_all(Manager *m, FDSet *fds); void bus_track_serialize(sd_bus_track *t, FILE *f, const char *prefix); -int bus_track_coldplug(Manager *m, sd_bus_track **t, bool recursive, char **l); +int bus_track_coldplug(sd_bus *bus, sd_bus_track **t, bool recursive, char **l); int bus_foreach_bus(Manager *m, sd_bus_track *subscribed2, int (*send_message)(sd_bus *bus, void *userdata), void *userdata); diff --git a/src/core/manager.c b/src/core/manager.c index f21a4f7ceb8..8fb52666c0f 100644 --- a/src/core/manager.c +++ b/src/core/manager.c @@ -1803,6 +1803,9 @@ Manager* manager_free(Manager *m) { free(m->switch_root); free(m->switch_root_init); + sd_bus_track_unref(m->subscribed); + strv_free(m->deserialized_subscribed); + unit_defaults_done(&m->defaults); FOREACH_ARRAY(map, m->units_needing_mounts_for, _UNIT_MOUNT_DEPENDENCY_TYPE_MAX) { @@ -2139,7 +2142,7 @@ int manager_startup(Manager *m, FILE *serialization, FDSet *fds, const char *roo manager_setup_bus(m); /* Now that we are connected to all possible buses, let's deserialize who is tracking us. */ - r = bus_track_coldplug(m, &m->subscribed, false, m->deserialized_subscribed); + r = bus_track_coldplug(m->api_bus, &m->subscribed, false, m->deserialized_subscribed); if (r < 0) log_warning_errno(r, "Failed to deserialized tracked clients, ignoring: %m"); m->deserialized_subscribed = strv_free(m->deserialized_subscribed); @@ -3813,9 +3816,6 @@ int manager_reload(Manager *m) { /* Clean up runtime objects no longer referenced */ manager_vacuum(m); - /* Clean up deserialized tracked clients */ - m->deserialized_subscribed = strv_free(m->deserialized_subscribed); - /* Consider the reload process complete now. */ assert(m->n_reloading > 0); m->n_reloading--; diff --git a/src/shared/bus-util.c b/src/shared/bus-util.c index 8313dfdd14e..f6d88564b6c 100644 --- a/src/shared/bus-util.c +++ b/src/shared/bus-util.c @@ -698,6 +698,28 @@ int bus_track_add_name_many(sd_bus_track *t, char **l) { return r; } +int bus_track_to_strv(sd_bus_track *t, char ***ret) { + _cleanup_strv_free_ char **subscribed = NULL; + int r = 0; + + assert(ret); + + for (const char *n = sd_bus_track_first(t); n; n = sd_bus_track_next(t)) { + r = sd_bus_track_count_name(t, n); + if (r < 0) + return r; + + for (int j = 0; j < r; j++) { + r = strv_extend(&subscribed, n); + if (r < 0) + return r; + } + } + + *ret = TAKE_PTR(subscribed); + return r; +} + int bus_open_system_watch_bind_with_description(sd_bus **ret, const char *description) { _cleanup_(sd_bus_close_unrefp) sd_bus *bus = NULL; const char *e; diff --git a/src/shared/bus-util.h b/src/shared/bus-util.h index e1908ecbaaf..95b9adb7b1b 100644 --- a/src/shared/bus-util.h +++ b/src/shared/bus-util.h @@ -66,6 +66,7 @@ int bus_path_encode_unique(sd_bus *b, const char *prefix, const char *sender_id, int bus_path_decode_unique(const char *path, const char *prefix, char **ret_sender, char **ret_external); int bus_track_add_name_many(sd_bus_track *t, char **l); +int bus_track_to_strv(sd_bus_track *t, char ***ret); int bus_open_system_watch_bind_with_description(sd_bus **ret, const char *description); static inline int bus_open_system_watch_bind(sd_bus **ret) {