From e730ae877a24d44f5b3db096f08b0a2d7399aa2d Mon Sep 17 00:00:00 2001
From: Jeff Sharkey <jsharkey@android.com>
Date: Tue, 14 Mar 2017 23:37:35 -0600
Subject: [PATCH] Enable cache clearing v2 logic, fix bugs.

Now that we have CTS tests to verify the cache clearing v2 logic,
we're ready to enable it!

Switch storage APIs over to "usable space" to match implementation
down in installd.  Add a missing clearCallingIdentity(), and offer
better logging for missing appop permission.

Load quotas from disk right away at device boot instead of waiting.

Bug: 35685848, 35684969
Test: cts-tradefed run commandAndExit cts-dev -m CtsAppSecurityHostTestCases -t android.appsecurity.cts.StorageHostTest
Change-Id: I8167e0322b4662ca6c975da5c50715e2d71332a7
---
 .../app/usage/StorageStatsManager.java        |  6 +++---
 .../server/pm/PackageManagerService.java      |  2 +-
 .../server/usage/StorageStatsService.java     | 20 ++++++++++++-------
 3 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/core/java/android/app/usage/StorageStatsManager.java b/core/java/android/app/usage/StorageStatsManager.java
index 82762293a241c..b808c2b75203a 100644
--- a/core/java/android/app/usage/StorageStatsManager.java
+++ b/core/java/android/app/usage/StorageStatsManager.java
@@ -81,9 +81,9 @@ public class StorageStatsManager {
     /**
      * Return the free space on the requested storage volume.
      * <p>
-     * The free space is equivalent to {@link File#getFreeSpace()} plus the size
-     * of any cached data that can be automatically deleted by the system as
-     * additional space is needed.
+     * The free space is equivalent to {@link File#getUsableSpace()} plus the
+     * size of any cached data that can be automatically deleted by the system
+     * as additional space is needed.
      * <p>
      * This method may take several seconds to calculate the requested values,
      * so it should only be called from a worker thread.
diff --git a/services/core/java/com/android/server/pm/PackageManagerService.java b/services/core/java/com/android/server/pm/PackageManagerService.java
index c27806d80ac92..e348051bb15f6 100644
--- a/services/core/java/com/android/server/pm/PackageManagerService.java
+++ b/services/core/java/com/android/server/pm/PackageManagerService.java
@@ -399,7 +399,7 @@ public class PackageManagerService extends IPackageManager.Stub {
     private static final boolean HIDE_EPHEMERAL_APIS = false;
 
     private static final boolean ENABLE_FREE_CACHE_V2 =
-            SystemProperties.getBoolean("fw.free_cache_v2", false);
+            SystemProperties.getBoolean("fw.free_cache_v2", true);
 
     private static final int RADIO_UID = Process.PHONE_UID;
     private static final int LOG_UID = Process.LOG_UID;
diff --git a/services/usage/java/com/android/server/usage/StorageStatsService.java b/services/usage/java/com/android/server/usage/StorageStatsService.java
index ebd4b019790a8..0a3f596ad5631 100644
--- a/services/usage/java/com/android/server/usage/StorageStatsService.java
+++ b/services/usage/java/com/android/server/usage/StorageStatsService.java
@@ -105,7 +105,7 @@ public class StorageStatsService extends IStorageStatsManager.Stub {
         invalidateMounts();
 
         mHandler = new H(IoThread.get().getLooper());
-        mHandler.sendEmptyMessageDelayed(H.MSG_LOAD_CACHED_QUOTAS_FROM_FILE, DELAY_IN_MILLIS);
+        mHandler.sendEmptyMessage(H.MSG_LOAD_CACHED_QUOTAS_FROM_FILE);
 
         mStorage.registerListener(new StorageEventListener() {
             @Override
@@ -137,7 +137,8 @@ public class StorageStatsService extends IStorageStatsManager.Stub {
                         android.Manifest.permission.PACKAGE_USAGE_STATS, TAG);
                 return;
             default:
-                throw new SecurityException("Blocked by mode " + mode);
+                throw new SecurityException("Package " + callingPackage + " from UID " + callingUid
+                        + " blocked by mode " + mode);
         }
     }
 
@@ -169,16 +170,21 @@ public class StorageStatsService extends IStorageStatsManager.Stub {
         enforcePermission(Binder.getCallingUid(), callingPackage);
 
         long cacheBytes = 0;
-        for (UserInfo user : mUser.getUsers()) {
-            final StorageStats stats = queryStatsForUser(volumeUuid, user.id, null);
-            cacheBytes += stats.cacheBytes;
+        final long token = Binder.clearCallingIdentity();
+        try {
+            for (UserInfo user : mUser.getUsers()) {
+                final StorageStats stats = queryStatsForUser(volumeUuid, user.id, null);
+                cacheBytes += stats.cacheBytes;
+            }
+        } finally {
+            Binder.restoreCallingIdentity(token);
         }
 
         if (volumeUuid == StorageManager.UUID_PRIVATE_INTERNAL) {
-            return Environment.getDataDirectory().getFreeSpace() + cacheBytes;
+            return Environment.getDataDirectory().getUsableSpace() + cacheBytes;
         } else {
             final VolumeInfo vol = mStorage.findVolumeByUuid(volumeUuid);
-            return vol.getPath().getFreeSpace() + cacheBytes;
+            return vol.getPath().getUsableSpace() + cacheBytes;
         }
     }