Pass bind mount storage data decision from java to zygote

Before we used store dirty data in system property to record
if FUSE for a user is mounted, and zygote uses it to determine
if storage mount is needed. It introduces performance issues and
not reliable.

This CL does the following changes:

- System server determines if storage dirs mount are needed, and store
the record inside system server.

- It passes the verdict to zygote so zygote just need to follow the
input.

- When emulated storage is mounted / unmounted, it will record if
FUSE for that user is ready to use, and will be used for determining
if storage dirs mount are needed when a new process starts.

- After emulated storage is mounted, it will create an async thread
to remount all storage dirs for existing app processes. As we have a
record of pids that storage dirs are not mounted yet, we can use it
directly without scanning the whole /proc in vold.

Bug: 149548518
Test: After flag is enabled, AdoptableHostTest still pass.
Change-Id: Ic99d027d42b2b9a1c7fd03070b36c44882c6e7c5

1 files changed, 7 insertions, 0 deletions

diff --git a/core/java/android/app/ActivityManagerInternal.java b/core/java/android/app/ActivityManagerInternal.java
index ec110435d95c..489a0de0518e 100644
--- a/core/java/android/app/ActivityManagerInternal.java
+++ b/core/java/android/app/ActivityManagerInternal.java
@@ -34,6 +34,7 @@ import android.os.TransactionTooLargeException;
 
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;
 
 /**
  * Activity manager local system service interface.
@@ -124,6 +125,12 @@ public abstract class ActivityManagerInternal {
     public abstract int getUidProcessState(int uid);
 
     /**
+     * Get a map of pid and package name that process of that pid Android/data and Android/obb
+     * directory is not mounted to lowerfs.
+     */
+    public abstract Map<Integer, String> getProcessesWithPendingBindMounts(int userId);
+
+    /**
      * @return {@code true} if system is ready, {@code false} otherwise.
      */
     public abstract boolean isSystemReady();