udevadm: beef up deprecation log warning

Let's add a catalog entry explaining further details.

Most importantly though: talk to PID 1 directly, via the private D-Bus
socket, so that this actually works correctly during early boot, where
D-Bus is not around.

1 files changed, 51 insertions, 34 deletions

diff --git a/src/udev/udevadm-settle.c b/src/udev/udevadm-settle.c
index 5730349ba5..66c7103d78 100644
--- a/src/udev/udevadm-settle.c
+++ b/src/udev/udevadm-settle.c
@@ -14,7 +14,9 @@
 
 #include "sd-bus.h"
 #include "sd-login.h"
+#include "sd-messages.h"
 
+#include "bus-util.h"
 #include "io-util.h"
 #include "libudev-util.h"
 #include "string-util.h"
@@ -87,54 +89,69 @@ static int parse_argv(int argc, char *argv[]) {
 
 static int emit_deprecation_warning(void) {
         _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
-        _cleanup_free_ char *unit = NULL, *unit_path = NULL;
-        _cleanup_strv_free_ char **a = NULL, **b = NULL;
+        _cleanup_strv_free_ char **a = NULL;
+        _cleanup_free_ char *unit = NULL;
         int r;
 
         r = sd_pid_get_unit(0, &unit);
-        if (r < 0 || !streq(unit, "systemd-udev-settle.service"))
+        if (r < 0) {
+                log_debug_errno(r, "Failed to determine unit we run in, ignoring: %m");
                 return 0;
+        }
 
-        log_notice("systemd-udev-settle.service is deprecated.");
+        if (!streq(unit, "systemd-udev-settle.service"))
+                return 0;
 
-        r = sd_bus_open_system(&bus);
-        if (r < 0)
-                return log_debug_errno(r, "Failed to open system bus, skipping dependency queries: %m");
-
-        unit_path = unit_dbus_path_from_name("systemd-udev-settle.service");
-        if (!unit_path)
-                return -ENOMEM;
-
-        (void) sd_bus_get_property_strv(
-                        bus,
-                        "org.freedesktop.systemd1",
-                        unit_path,
-                        "org.freedesktop.systemd1.Unit",
-                        "WantedBy",
-                        NULL,
-                        &a);
-
-        (void) sd_bus_get_property_strv(
-                        bus,
-                        "org.freedesktop.systemd1",
-                        unit_path,
-                        "org.freedesktop.systemd1.Unit",
-                        "RequiredBy",
-                        NULL,
-                        &b);
-
-        r = strv_extend_strv(&a, b, true);
+        r = bus_connect_system_systemd(&bus);
         if (r < 0)
-                return r;
+                log_debug_errno(r, "Failed to open connection to systemd, skipping dependency queries: %m");
+        else {
+                _cleanup_strv_free_ char **b = NULL;
+                _cleanup_free_ char *unit_path = NULL;
+
+                unit_path = unit_dbus_path_from_name("systemd-udev-settle.service");
+                if (!unit_path)
+                        return -ENOMEM;
+
+                (void) sd_bus_get_property_strv(
+                                bus,
+                                "org.freedesktop.systemd1",
+                                unit_path,
+                                "org.freedesktop.systemd1.Unit",
+                                "WantedBy",
+                                NULL,
+                                &a);
+
+                (void) sd_bus_get_property_strv(
+                                bus,
+                                "org.freedesktop.systemd1",
+                                unit_path,
+                                "org.freedesktop.systemd1.Unit",
+                                "RequiredBy",
+                                NULL,
+                                &b);
+
+                r = strv_extend_strv(&a, b, true);
+                if (r < 0)
+                        return r;
+        }
 
-        if (!strv_isempty(a)) {
+        if (strv_isempty(a))
+                /* Print a simple message if we cannot determine the dependencies */
+                log_notice("systemd-udev-settle.service is deprecated.");
+        else {
+                /* Print a longer, structured message if we can acquire the dependencies (this should be the
+                 * common case). This is hooked up with a catalog entry and everything. */
                 _cleanup_free_ char *t = NULL;
 
                 t = strv_join(a, ", ");
                 if (!t)
                         return -ENOMEM;
 
-                log_notice("Hint: please fix %s not to pull it in.", t);
+                log_struct(LOG_NOTICE,
+                           "MESSAGE=systemd-udev-settle.service is deprecated. Please fix %s not to pull it in.", t,
+                           "OFFENDING_UNITS=%s", t,
+                           "MESSAGE_ID=" SD_MESSAGE_SYSTEMD_UDEV_SETTLE_DEPRECATED_STR);
         }
 
         return 0;