Fix StrictMode I/O violations

onBeforeUnlockUser now happens on a worker thread that allows I/O.
In addition to that STATE_RUNNING_UNLOCKING is only set after
onBeforeUnlockUser. Otherwise non-DBA processes would be able to start
before unlocking completes (causing b/68995913)

Recents are now loaded on a worker thread

Bug: 68872660
Bug: 68871386
Test: UserControllerTest
Test: Tested on marlin/walleye (+factory reset)
Test: create/start work profile. create/start guest user
Change-Id: I4694dfa0bd523de33f0e600f2db22d02610b535c

1 files changed, 25 insertions, 13 deletions

diff --git a/services/core/java/com/android/server/am/UserController.java b/services/core/java/com/android/server/am/UserController.java
index 2df5dc93768c..4e3d8d27e0f9 100644
--- a/services/core/java/com/android/server/am/UserController.java
+++ b/services/core/java/com/android/server/am/UserController.java
@@ -89,6 +89,7 @@ import com.android.internal.logging.MetricsLogger;
 import com.android.internal.util.ArrayUtils;
 import com.android.internal.util.Preconditions;
 import com.android.internal.widget.LockPatternUtils;
+import com.android.server.FgThread;
 import com.android.server.LocalServices;
 import com.android.server.SystemServiceManager;
 import com.android.server.pm.UserManagerService;
@@ -355,27 +356,35 @@ class UserController implements Handler.Callback {
         // Only keep marching forward if user is actually unlocked
         if (!StorageManager.isUserKeyUnlocked(userId)) return;
         synchronized (mLock) {
-            // Bail if we ended up with a stale user
-            if (mStartedUsers.get(uss.mHandle.getIdentifier()) != uss) return;
-
-            // Do not proceed if unexpected state
-            if (!uss.setState(STATE_RUNNING_LOCKED, STATE_RUNNING_UNLOCKING)) {
+            // Do not proceed if unexpected state or a stale user
+            if (mStartedUsers.get(userId) != uss || uss.state != STATE_RUNNING_LOCKED) {
                 return;
             }
         }
-        mInjector.getUserManagerInternal().setUserState(userId, uss.state);
         uss.mUnlockProgress.start();
 
         // Prepare app storage before we go any further
         uss.mUnlockProgress.setProgress(5,
                     mInjector.getContext().getString(R.string.android_start_title));
-        mInjector.getUserManager().onBeforeUnlockUser(userId);
-        uss.mUnlockProgress.setProgress(20);
 
-        // Dispatch unlocked to system services; when fully dispatched,
-        // that calls through to the next "unlocked" phase
-        mHandler.obtainMessage(SYSTEM_USER_UNLOCK_MSG, userId, 0, uss)
-                .sendToTarget();
+        // Call onBeforeUnlockUser on a worker thread that allows disk I/O
+        FgThread.getHandler().post(() -> {
+            mInjector.getUserManager().onBeforeUnlockUser(userId);
+            synchronized (mLock) {
+                // Do not proceed if unexpected state
+                if (!uss.setState(STATE_RUNNING_LOCKED, STATE_RUNNING_UNLOCKING)) {
+                    return;
+                }
+            }
+            mInjector.getUserManagerInternal().setUserState(userId, uss.state);
+
+            uss.mUnlockProgress.setProgress(20);
+
+            // Dispatch unlocked to system services; when fully dispatched,
+            // that calls through to the next "unlocked" phase
+            mHandler.obtainMessage(SYSTEM_USER_UNLOCK_MSG, userId, 0, uss)
+                    .sendToTarget();
+        });
     }
 
     /**
@@ -1819,7 +1828,10 @@ class UserController implements Handler.Callback {
             case SYSTEM_USER_UNLOCK_MSG:
                 final int userId = msg.arg1;
                 mInjector.getSystemServiceManager().unlockUser(userId);
-                mInjector.loadUserRecents(userId);
+                // Loads recents on a worker thread that allows disk I/O
+                FgThread.getHandler().post(() -> {
+                    mInjector.loadUserRecents(userId);
+                });
                 if (userId == UserHandle.USER_SYSTEM) {
                     mInjector.startPersistentApps(PackageManager.MATCH_DIRECT_BOOT_UNAWARE);
                 }