fsck: atomically replace base.target by rescue.target/reboot.target when fsck fails

2 files changed, 43 insertions, 15 deletions

diff --git a/src/dbus-manager.c b/src/dbus-manager.c
index c700abbe22..52638435c2 100644
--- a/src/dbus-manager.c
+++ b/src/dbus-manager.c
@@ -48,6 +48,12 @@
         "   <arg name=\"mode\" type=\"s\" direction=\"in\"/>\n"         \
         "   <arg name=\"job\" type=\"o\" direction=\"out\"/>\n"         \
         "  </method>\n"                                                 \
+        "  <method name=\"StartUnitReplace\">\n"                        \
+        "   <arg name=\"old_unit\" type=\"s\" direction=\"in\"/>\n"     \
+        "   <arg name=\"new_unit\" type=\"s\" direction=\"in\"/>\n"     \
+        "   <arg name=\"mode\" type=\"s\" direction=\"in\"/>\n"         \
+        "   <arg name=\"job\" type=\"o\" direction=\"out\"/>\n"         \
+        "  </method>\n"                                                 \
         "  <method name=\"StopUnit\">\n"                                \
         "   <arg name=\"name\" type=\"s\" direction=\"in\"/>\n"         \
         "   <arg name=\"mode\" type=\"s\" direction=\"in\"/>\n"         \
@@ -408,6 +414,8 @@ static DBusHandlerResult bus_manager_message_handler(DBusConnection *connection,
 
         } else if (dbus_message_is_method_call(message, "org.freedesktop.systemd1.Manager", "StartUnit"))
                 job_type = JOB_START;
+        else if (dbus_message_is_method_call(message, "org.freedesktop.systemd1.Manager", "StartUnitReplace"))
+                job_type = JOB_START;
         else if (dbus_message_is_method_call(message, "org.freedesktop.systemd1.Manager", "StopUnit"))
                 job_type = JOB_STOP;
         else if (dbus_message_is_method_call(message, "org.freedesktop.systemd1.Manager", "ReloadUnit"))
@@ -910,19 +918,40 @@ static DBusHandlerResult bus_manager_message_handler(DBusConnection *connection,
                 return bus_default_message_handler(m, connection, message, NULL, properties);
 
         if (job_type != _JOB_TYPE_INVALID) {
-                const char *name, *smode;
+                const char *name, *smode, *old_name = NULL;
                 JobMode mode;
                 Job *j;
                 Unit *u;
-
-                if (!dbus_message_get_args(
-                                    message,
-                                    &error,
-                                    DBUS_TYPE_STRING, &name,
-                                    DBUS_TYPE_STRING, &smode,
-                                    DBUS_TYPE_INVALID))
+                bool b;
+
+                if (dbus_message_is_method_call(message, "org.freedesktop.systemd1.Manager", "StartUnitReplace"))
+                        b = dbus_message_get_args(
+                                        message,
+                                        &error,
+                                        DBUS_TYPE_STRING, &old_name,
+                                        DBUS_TYPE_STRING, &name,
+                                        DBUS_TYPE_STRING, &smode,
+                                        DBUS_TYPE_INVALID);
+                else
+                        b = dbus_message_get_args(
+                                        message,
+                                        &error,
+                                        DBUS_TYPE_STRING, &name,
+                                        DBUS_TYPE_STRING, &smode,
+                                        DBUS_TYPE_INVALID);
+
+                if (!b)
                         return bus_send_error_reply(m, connection, message, &error, -EINVAL);
 
+                if (old_name)
+                        if (!(u = manager_get_unit(m, old_name)) ||
+                            !u->meta.job ||
+                            u->meta.job->type != JOB_START) {
+                                dbus_set_error(&error, BUS_ERROR_NO_SUCH_JOB, "No job queued for unit %s", old_name);
+                                return bus_send_error_reply(m, connection, message, &error, -ENOENT);
+                        }
+
+
                 if ((mode = job_mode_from_string(smode)) == _JOB_MODE_INVALID) {
                         dbus_set_error(&error, BUS_ERROR_INVALID_JOB_MODE, "Job mode %s is invalid.", smode);
                         return bus_send_error_reply(m, connection, message, &error, -EINVAL);
diff --git a/src/fsck.c b/src/fsck.c
index 702f22c95d..b0c3620c8c 100644
--- a/src/fsck.c
+++ b/src/fsck.c
@@ -38,7 +38,7 @@ static bool arg_force = false;
 static void start_target(const char *target, bool isolate) {
         DBusMessage *m = NULL, *reply = NULL;
         DBusError error;
-        const char *mode;
+        const char *mode, *base_target = "base.target";
         DBusConnection *bus = NULL;
 
         assert(target);
@@ -57,12 +57,15 @@ static void start_target(const char *target, bool isolate) {
 
         log_debug("Running request %s/start/%s", target, mode);
 
-        if (!(m = dbus_message_new_method_call("org.freedesktop.systemd1", "/org/freedesktop/systemd1", "org.freedesktop.systemd1.Manager", "StartUnit"))) {
+        if (!(m = dbus_message_new_method_call("org.freedesktop.systemd1", "/org/freedesktop/systemd1", "org.freedesktop.systemd1.Manager", "StartUnitReplace"))) {
                 log_error("Could not allocate message.");
                 goto finish;
         }
 
+        /* Start these units only if we can replace base.target with it */
+
         if (!dbus_message_append_args(m,
+                                      DBUS_TYPE_STRING, &base_target,
                                       DBUS_TYPE_STRING, &target,
                                       DBUS_TYPE_STRING, &mode,
                                       DBUS_TYPE_INVALID)) {
@@ -196,11 +199,7 @@ int main(int argc, char *argv[]) {
         }
 
         if (status.si_status & ~1) {
-
-                if (access("/dev/.systemd/late-fsck", F_OK) >= 0) {
-                        log_error("fsck failed with error code %i.", status.si_status);
-                        goto finish;
-                }
+                log_error("fsck failed with error code %i.", status.si_status);
 
                 if (status.si_status & 2)
                         /* System should be rebooted. */