Mount vendor overlay from the system partition

Using overlayfs, the system partition may provide files for older
version of vendor partitions by overlaying on the vendor partition.
Directories in /system/vendor_overlay will be overlaid on the
directories in /vendor to override existing files or provide new
files.

This feature works only if the kernel support overlayfs and has a
patch for override_creds. Otherwise, no-op.

Bug: 114679254
Test: Build and boot: nothing affected without overlayfs, or
                      vendor file is overrided with overlayfs

Change-Id: Iff3a308945299034123ba7bcb40dc787e102730e

1 files changed, 2 insertions, 0 deletions

diff --git a/init/init.cpp b/init/init.cpp
index b12ba8c89..90803f794 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -39,6 +39,7 @@
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 #include <cutils/android_reboot.h>
+#include <fs_mgr_vendor_overlay.h>
 #include <keyutils.h>
 #include <libavb/libavb.h>
 #include <selinux/android.h>
@@ -717,6 +718,7 @@ int main(int argc, char** argv) {
     InstallSignalFdHandler(&epoll);
 
     property_load_boot_defaults();
+    fs_mgr_vendor_overlay_mount_all();
     export_oem_lock_status();
     StartPropertyService(&epoll);
     set_usb_controller();