DO NOT MERGE: Fix several issues with precreated users.

1. Prevent UserManager from destroying storage for precreated users.
2. Modify UMS.getUserIds to exclude precreated users.
3. Remove pre-created users if the system has upgraded.
4. Read permissions during conversion to a "real" user. Permissions should have been granted during the pre-creation. If we cannot read permissions, re-grant them for the user.

Fixes: 143464654
Fixes: 143463955
Test: Repeated subsequent boots; observing logs; boot systrace; applied OTA, verified user cleanup
Change-Id: I75b031105b2622a8a28e84cf2394e43ec93e4174

core/java/android/os/UserManager.java

@@ -2042,6 +2042,13 @@ public class UserManager {
      * by {@link #createUser(String, int)} or {@link #createGuest(Context, String)}), it takes
      * less time.
      *
+     * <p>This method completes the majority of work necessary for user creation: it
+     * creates user data, CE and DE encryption keys, app data directories, initializes the user and
+     * grants default permissions. When pre-created users become "real" users, only then are
+     * components notified of new user creation by firing user creation broadcasts.
+     *
+     * <p>All pre-created users are removed during system upgrade.
+     *
      * <p>Requires {@link android.Manifest.permission#MANAGE_USERS} permission.
      *
      * @param flags UserInfo flags that identify the type of user and other properties.
@@ -2055,6 +2062,7 @@ public class UserManager {
      *
      * @hide
      */
+    @RequiresPermission(android.Manifest.permission.MANAGE_USERS)
     public @Nullable UserInfo preCreateUser(@UserInfoFlag int flags) {
         try {
             return mService.preCreateUser(flags);

services/core/java/com/android/server/pm/PackageManagerService.java

@@ -23713,6 +23713,13 @@ public class PackageManagerService extends IPackageManager.Stub
         }
     }
 
+    boolean readPermissionStateForUser(@UserIdInt int userId) {
+        synchronized (mPackages) {
+            mSettings.readPermissionStateForUserSyncLPr(userId);
+            return mSettings.areDefaultRuntimePermissionsGrantedLPr(userId);
+        }
+    }
+
     @Override
     public VerifierDeviceIdentity getVerifierDeviceIdentity() throws RemoteException {
         mContext.enforceCallingOrSelfPermission(

services/core/java/com/android/server/pm/Settings.java

@@ -3140,6 +3140,10 @@ public final class Settings {
         return true;
     }
 
+    void readPermissionStateForUserSyncLPr(@UserIdInt int userId) {
+        mRuntimePermissionsPersistence.readStateForUserSyncLPr(userId);
+    }
+
     void applyDefaultPreferredAppsLPw(int userId) {
         // First pull data from any pre-installed apps.
         final PackageManagerInternal pmInternal =

services/core/java/com/android/server/pm/UserManagerService.java

@@ -479,6 +479,10 @@ public class UserManagerService extends IUserManager.Stub {
         public void onBootPhase(int phase) {
             if (phase == SystemService.PHASE_ACTIVITY_MANAGER_READY) {
                 mUms.cleanupPartialUsers();
+
+                if (mUms.mPm.isDeviceUpgrading()) {
+                    mUms.cleanupPreCreatedUsers();
+                }
             }
         }
 
@@ -603,6 +607,33 @@ public class UserManagerService extends IUserManager.Stub {
         }
     }
 
+    /**
+     * Removes any pre-created users from the system. Should be invoked after OTAs, to ensure
+     * pre-created users are not stale. New pre-created pool can be re-created after the update.
+     */
+    void cleanupPreCreatedUsers() {
+        final ArrayList<UserInfo> preCreatedUsers;
+        synchronized (mUsersLock) {
+            final int userSize = mUsers.size();
+            preCreatedUsers = new ArrayList<>(userSize);
+            for (int i = 0; i < userSize; i++) {
+                UserInfo ui = mUsers.valueAt(i).info;
+                if (ui.preCreated) {
+                    preCreatedUsers.add(ui);
+                    addRemovingUserIdLocked(ui.id);
+                    ui.flags |= UserInfo.FLAG_DISABLED;
+                    ui.partial = true;
+                }
+            }
+        }
+        final int preCreatedSize = preCreatedUsers.size();
+        for (int i = 0; i < preCreatedSize; i++) {
+            UserInfo ui = preCreatedUsers.get(i);
+            Slog.i(LOG_TAG, "Removing pre-created user " + ui.id);
+            removeUserState(ui.id);
+        }
+    }
+
     @Override
     public String getUserAccount(int userId) {
         checkManageUserAndAcrossUsersFullPermission("get user account");
@@ -2762,11 +2793,17 @@ public class UserManagerService extends IUserManager.Stub {
                 preCreatedUser.preCreated = false;
                 preCreatedUser.creationTime = getCreationTime();
 
-                dispatchUserAddedIntent(preCreatedUser);
+                synchronized (mPackagesLock) {
-
                     writeUserLP(preCreatedUserData);
                     writeUserListLP();
+                }
 
+                updateUserIds();
+                if (!mPm.readPermissionStateForUser(preCreatedUser.id)) {
+                    // Could not read the existing permissions, re-grant them.
+                    mPm.onNewUserCreated(preCreatedUser.id);
+                }
+                dispatchUserAddedIntent(preCreatedUser);
                 return preCreatedUser;
             }
         }
@@ -2900,7 +2937,10 @@ public class UserManagerService extends IUserManager.Stub {
             synchronized (mRestrictionsLock) {
                 mBaseUserRestrictions.append(userId, restrictions);
             }
+
+            t.traceBegin("PM.onNewUserCreated-" + userId);
             mPm.onNewUserCreated(userId);
+            t.traceEnd();
             if (preCreate) {
                 // Must start user (which will be stopped right away, through
                 // UserController.finishUserUnlockedCompleted) so services can properly
@@ -3599,14 +3639,16 @@ public class UserManagerService extends IUserManager.Stub {
         synchronized (mUsersLock) {
             final int userSize = mUsers.size();
             for (int i = 0; i < userSize; i++) {
-                if (!mUsers.valueAt(i).info.partial) {
+                UserInfo userInfo = mUsers.valueAt(i).info;
+                if (!userInfo.partial && !userInfo.preCreated) {
                     num++;
                 }
             }
             final int[] newUsers = new int[num];
             int n = 0;
             for (int i = 0; i < userSize; i++) {
-                if (!mUsers.valueAt(i).info.partial) {
+                UserInfo userInfo = mUsers.valueAt(i).info;
+                if (!userInfo.partial && !userInfo.preCreated) {
                     newUsers[n++] = mUsers.keyAt(i);
                 }
             }
@@ -3658,7 +3700,10 @@ public class UserManagerService extends IUserManager.Stub {
      * recycled.
      */
     void reconcileUsers(String volumeUuid) {
-        mUserDataPreparer.reconcileUsers(volumeUuid, getUsers(true /* excludeDying */));
+        mUserDataPreparer.reconcileUsers(volumeUuid, getUsers(
+                /* excludePartial= */ true,
+                /* excludeDying= */ true,
+                /* excludePreCreated= */ false));
     }
 
     /**