Merge changes from topic "userspace-reboot-bootstrap-namespace"

* changes:
  Stop & Resume property service when switching to bootstrap namespace
  Reset post_data_ and services_update_finished_ on userspace reboot

init/mount_namespace.cpp

@@ -323,10 +323,20 @@ bool SwitchToBootstrapMountNamespaceIfNeeded() {
     }
     if (bootstrap_ns_id != GetMountNamespaceId() && bootstrap_ns_fd.get() != -1 &&
         IsApexUpdatable()) {
+        // The property service thread and its descendent threads must be in the correct mount
+        // namespace to call Service::Start(), however setns() only operates on a single thread and
+        // fails when secondary threads attempt to join the same mount namespace.  Therefore, we
+        // must join the property service thread and its descendents before the setns() call.  Those
+        // threads are then started again after the setns() call, and they'll be in the proper
+        // namespace.
+        PausePropertyService();
+
         if (setns(bootstrap_ns_fd.get(), CLONE_NEWNS) == -1) {
             PLOG(ERROR) << "Failed to switch to bootstrap mount namespace.";
             return false;
         }
+
+        ResumePropertyService();
     }
     return true;
 }

init/reboot.cpp

@@ -820,6 +820,7 @@ static Result<void> DoUserspaceReboot() {
         LOG(INFO) << "Re-enabling service '" << s->name() << "'";
         s->Enable();
     }
+    ServiceList::GetInstance().ResetState();
     LeaveShutdown();
     ActionManager::GetInstance().QueueEventTrigger("userspace-reboot-resume");
     guard.Disable();  // Go on with userspace reboot.

init/service_list.h

@@ -81,6 +81,11 @@ class ServiceList {
     bool IsServicesUpdated() const { return services_update_finished_; }
     void DelayService(const Service& service) REQUIRES(service_lock);
 
+    void ResetState() {
+        post_data_ = false;
+        services_update_finished_ = false;
+    }
+
   private:
     std::vector<std::unique_ptr<Service>> services_;