am c9e59899: Merge "Clarify rules about encryption of emulated storage." into honeycomb-mr1

* commit 'c9e598995db68cf97dc3ed0fc527a35e2d966afd':
  Clarify rules about encryption of emulated storage.

2 files changed, 15 insertions, 4 deletions

diff --git a/core/java/android/app/admin/DevicePolicyManager.java b/core/java/android/app/admin/DevicePolicyManager.java
index 440cb5406b85..efe263336063 100644
--- a/core/java/android/app/admin/DevicePolicyManager.java
+++ b/core/java/android/app/admin/DevicePolicyManager.java
@@ -1150,8 +1150,12 @@ public class DevicePolicyManager {
      * fail (most commonly returning {@link #ENCRYPTION_STATUS_ACTIVE}).
      *
      * <p>This policy controls encryption of the secure (application data) storage area.  Data
-     * written to other areas (e.g. the directory returned by
-     * {@link android.os.Environment#getExternalStorageDirectory()} may or may not be encrypted.
+     * written to other storage areas may or may not be encrypted, and this policy does not require
+     * or control the encryption of any other storage areas.
+     * There is one exception:  If {@link android.os.Environment#isExternalStorageEmulated()} is
+     * {@code true}, then the directory returned by
+     * {@link android.os.Environment#getExternalStorageDirectory()} must be written to disk
+     * within the encrypted storage area.
      *
      * <p>Important Note:  On some devices, it is possible to encrypt storage without requiring
      * the user to create a device PIN or Password.  In this case, the storage is encrypted, but
diff --git a/core/java/android/os/Environment.java b/core/java/android/os/Environment.java
index ec5030c7f5db..e308c2c48a8d 100644
--- a/core/java/android/os/Environment.java
+++ b/core/java/android/os/Environment.java
@@ -423,9 +423,16 @@ public class Environment {
 
     /**
      * Returns whether the device has an external storage device which is
-     * emulated. If true, the device does not have real external storage
-     * and certain system services such as the package manager use this
+     * emulated. If true, the device does not have real external storage, and the directory
+     * returned by {@link #getExternalStorageDirectory()} will be allocated using a portion of
+     * the internal storage system.
+     *
+     * <p>Certain system services, such as the package manager, use this
      * to determine where to install an application.
+     *
+     * <p>Emulated external storage may also be encrypted - see
+     * {@link android.app.admin.DevicePolicyManager#setStorageEncryption(
+     * android.content.ComponentName, boolean)} for additional details.
      */
     public static boolean isExternalStorageEmulated() {
         if (mIsExternalStorageEmulated == null) {