From 0b66969ba03464bea45a12c978f51b59c4c200a9 Mon Sep 17 00:00:00 2001
From: Tri Vo <trong@google.com>
Date: Tue, 10 Apr 2018 20:20:13 -0700
Subject: [PATCH] Add /mnt/vendor rw mount point for vendor partitions.

Changes to init's behavior during early mount:
1. Mounting of tmpfs on /mnt is moved from init stage to early mount.
2. init creates /mnt/vendor used to mount vendor partitions.
3. If a device tree fstab entry for early mount specifies a mount point
under /mnt/vendor e.g. /mnt/vendor/foo, init will create
/mnt/vendor/foo mount point.

Bug: 64905218
Test: change dt fstab entry to mount persist to /mnt/vendor/persist;
mount point is created correctly, and partition is mounted in early
mount. See go/pag/1069774
Test: device boots with /mnt/vendor and previous contents of /mnt present,
and selinux label "mnt_vendor_file" is applied correctly.
Test: cts-tradefed run commandAndExit cts --skip-all-system-status-check
--primary-abi-only --skip-preconditions -m CtsAppSecurityHostTestCases
-t android.appsecurity.cts.PermissionsHostTest
Change-Id: I3739130739eadf508355c7f2531366fcaed74175
Merged-In: I3739130739eadf508355c7f2531366fcaed74175
(cherry picked from commit b51147566461d411ad452df81d54dc800c554e06)
---
 init/init.cpp   | 8 ++++++++
 rootdir/init.rc | 6 ------
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/init/init.cpp b/init/init.cpp
index 2f3b28ac5..40b7e8793 100644
--- a/init/init.cpp
+++ b/init/init.cpp
@@ -624,6 +624,14 @@ int main(int argc, char** argv) {
         mknod("/dev/random", S_IFCHR | 0666, makedev(1, 8));
         mknod("/dev/urandom", S_IFCHR | 0666, makedev(1, 9));
 
+        // Mount staging areas for devices managed by vold
+        // See storage config details at http://source.android.com/devices/storage/
+        mount("tmpfs", "/mnt", "tmpfs", MS_NOEXEC | MS_NOSUID | MS_NODEV,
+              "mode=0755,uid=0,gid=1000");
+        // /mnt/vendor is used to mount vendor-specific partitions that can not be
+        // part of the vendor partition, e.g. because they are mounted read-write.
+        mkdir("/mnt/vendor", 0755);
+
         // Now that tmpfs is mounted on /dev and we have /dev/kmsg, we can actually
         // talk to the outside world...
         InitKernelLogging(argv);
diff --git a/rootdir/init.rc b/rootdir/init.rc
index 146257040..2d6414496 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -21,9 +21,6 @@ on early-init
     # Set the security context of /adb_keys if present.
     restorecon /adb_keys
 
-    # Shouldn't be necessary, but sdcard won't start without it. http://b/22568628.
-    mkdir /mnt 0775 root system
-
     # Set the security context of /postinstall if present.
     restorecon /postinstall
 
@@ -80,9 +77,6 @@ on init
     chmod 0664 /dev/stune/top-app/tasks
     chmod 0664 /dev/stune/rt/tasks
 
-    # Mount staging areas for devices managed by vold
-    # See storage config details at http://source.android.com/tech/storage/
-    mount tmpfs tmpfs /mnt nodev noexec nosuid mode=0755,uid=0,gid=1000
     restorecon_recursive /mnt
 
     mount configfs none /config nodev noexec nosuid