Merge "Avoid recycling recently removed user IDs." into jb-mr1.1-dev

Author: jsharkey

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

@@ -16,8 +16,7 @@
 
 package com.android.server.pm;
 
-import com.android.internal.util.ArrayUtils;
-import com.android.internal.util.FastXmlSerializer;
+import static android.text.format.DateUtils.MINUTE_IN_MILLIS;
 
 import android.app.Activity;
 import android.app.ActivityManager;
@@ -26,14 +25,14 @@
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
-import android.content.SharedPreferences;
 import android.content.pm.PackageManager;
 import android.content.pm.UserInfo;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.os.Binder;
 import android.os.Environment;
 import android.os.FileUtils;
+import android.os.Handler;
 import android.os.IUserManager;
 import android.os.Process;
 import android.os.RemoteException;
@@ -42,9 +41,17 @@
 import android.util.AtomicFile;
 import android.util.Slog;
 import android.util.SparseArray;
+import android.util.SparseBooleanArray;
 import android.util.TimeUtils;
 import android.util.Xml;
 
+import com.android.internal.util.ArrayUtils;
+import com.android.internal.util.FastXmlSerializer;
+
+import org.xmlpull.v1.XmlPullParser;
+import org.xmlpull.v1.XmlPullParserException;
+import org.xmlpull.v1.XmlSerializer;
+
 import java.io.BufferedOutputStream;
 import java.io.File;
 import java.io.FileDescriptor;
@@ -54,13 +61,8 @@
 import java.io.IOException;
 import java.io.PrintWriter;
 import java.util.ArrayList;
-import java.util.HashSet;
 import java.util.List;
 
-import org.xmlpull.v1.XmlPullParser;
-import org.xmlpull.v1.XmlPullParserException;
-import org.xmlpull.v1.XmlSerializer;
-
 public class UserManagerService extends IUserManager.Stub {
 
     private static final String LOG_TAG = "UserManagerService";
@@ -95,19 +97,24 @@ public class UserManagerService extends IUserManager.Stub {
     private final Object mInstallLock;
     private final Object mPackagesLock;
 
+    private final Handler mHandler;
+
     private final File mUsersDir;
     private final File mUserListFile;
     private final File mBaseUserPath;
 
-    private SparseArray<UserInfo> mUsers = new SparseArray<UserInfo>();
-    private HashSet<Integer> mRemovingUserIds = new HashSet<Integer>();
+    private final SparseArray<UserInfo> mUsers = new SparseArray<UserInfo>();
+
+    /**
+     * Set of user IDs being actively removed. Removed IDs linger in this set
+     * for several seconds to work around a VFS caching issue.
+     */
+    // @GuardedBy("mPackagesLock")
+    private final SparseBooleanArray mRemovingUserIds = new SparseBooleanArray();
 
     private int[] mUserIds;
     private boolean mGuestEnabled;
     private int mNextSerialNumber;
-    // This resets on a reboot. Otherwise it keeps incrementing so that user ids are
-    // not reused in quick succession
-    private int mNextUserId = MIN_USER_ID;
     private int mUserVersion = 0;
 
     private static UserManagerService sInstance;
@@ -147,6 +154,7 @@ private UserManagerService(Context context, PackageManagerService pm,
         mPm = pm;
         mInstallLock = installLock;
         mPackagesLock = packagesLock;
+        mHandler = new Handler();
         synchronized (mInstallLock) {
             synchronized (mPackagesLock) {
                 mUsersDir = new File(dataDir, USER_INFO_DIR);
@@ -190,7 +198,7 @@ public List<UserInfo> getUsers(boolean excludeDying) {
                 if (ui.partial) {
                     continue;
                 }
-                if (!excludeDying || !mRemovingUserIds.contains(ui.id)) {
+                if (!excludeDying || !mRemovingUserIds.get(ui.id)) {
                     users.add(ui);
                 }
             }
@@ -212,7 +220,7 @@ public UserInfo getUserInfo(int userId) {
     private UserInfo getUserInfoLocked(int userId) {
         UserInfo ui = mUsers.get(userId);
         // If it is partial and not in the process of being removed, return as unknown user.
-        if (ui != null && ui.partial && !mRemovingUserIds.contains(userId)) {
+        if (ui != null && ui.partial && !mRemovingUserIds.get(userId)) {
             Slog.w(LOG_TAG, "getUserInfo: unknown user #" + userId);
             return null;
         }
@@ -502,7 +510,7 @@ private void upgradeIfNecessary() {
 
     private void fallbackToSingleUserLocked() {
         // Create the primary user
-        UserInfo primary = new UserInfo(0, 
+        UserInfo primary = new UserInfo(0,
                 mContext.getResources().getString(com.android.internal.R.string.owner_name), null,
                 UserInfo.FLAG_ADMIN | UserInfo.FLAG_PRIMARY | UserInfo.FLAG_INITIALIZED);
         mUsers.put(0, primary);
@@ -749,7 +757,7 @@ public boolean removeUser(int userHandle) {
             if (userHandle == 0 || user == null) {
                 return false;
             }
-            mRemovingUserIds.add(userHandle);
+            mRemovingUserIds.put(userHandle, true);
             // Set this to a partially created user, so that the user will be purged
             // on next startup, in case the runtime stops now before stopping and
             // removing the user completely.
@@ -813,13 +821,25 @@ public void run() {
         }
     }
 
-    private void removeUserStateLocked(int userHandle) {
+    private void removeUserStateLocked(final int userHandle) {
         // Cleanup package manager settings
         mPm.cleanUpUserLILPw(userHandle);
 
         // Remove this user from the list
         mUsers.remove(userHandle);
-        mRemovingUserIds.remove(userHandle);
+
+        // Have user ID linger for several seconds to let external storage VFS
+        // cache entries expire. This must be greater than the 'entry_valid'
+        // timeout used by the FUSE daemon.
+        mHandler.postDelayed(new Runnable() {
+            @Override
+            public void run() {
+                synchronized (mPackagesLock) {
+                    mRemovingUserIds.delete(userHandle);
+                }
+            }
+        }, MINUTE_IN_MILLIS);
+
         // Remove user file
         AtomicFile userFile = new AtomicFile(new File(mUsersDir, userHandle + ".xml"));
         userFile.delete();
@@ -906,14 +926,13 @@ public void userForeground(int userId) {
      */
     private int getNextAvailableIdLocked() {
         synchronized (mPackagesLock) {
-            int i = mNextUserId;
+            int i = MIN_USER_ID;
             while (i < Integer.MAX_VALUE) {
-                if (mUsers.indexOfKey(i) < 0 && !mRemovingUserIds.contains(i)) {
+                if (mUsers.indexOfKey(i) < 0 && !mRemovingUserIds.get(i)) {
                     break;
                 }
                 i++;
             }
-            mNextUserId = i + 1;
             return i;
         }
     }
@@ -938,7 +957,7 @@ protected void dump(FileDescriptor fd, PrintWriter pw, String[] args) {
                 UserInfo user = mUsers.valueAt(i);
                 if (user == null) continue;
                 pw.print("  "); pw.print(user); pw.print(" serialNo="); pw.print(user.serialNumber);
-                if (mRemovingUserIds.contains(mUsers.keyAt(i))) pw.print(" <removing> ");
+                if (mRemovingUserIds.get(mUsers.keyAt(i))) pw.print(" <removing> ");
                 if (user.partial) pw.print(" <partial>");
                 pw.println();
                 pw.print("    Created: ");