Multi-user MTP.

The current MTP kernel driver at /dev/mtp_usb is exclusive, meaning
only one process can have it open. In addition, each MTP session
with a desktop requires unique object IDs, which doesn't hold true
across users on the device.

To solve these two issues, when switching users we cycle the USB host
stack to disconnect both local and remote MTP connections, giving the
new user's media process a chance to claim /dev/mtp_usb, and causing
the desktop to initiate a new MTP session.

This change also allows BroadcastReceivers to registerReceiver()
allow retrieval of a current sticky broadcast. Adds a system property
to override maximum users. Removes MOUNTED broadcasts for secondary
users. Allows INTERACT_ACROSS_USERS to getCurrentUser().

Bug: 6925114
Change-Id: I02b4a1b535af95fb2142655887b6d15a8068d18a

1 files changed, 0 insertions, 32 deletions

diff --git a/services/java/com/android/server/MountService.java b/services/java/com/android/server/MountService.java
index 32ab1542c3df..ba758e5a9a20 100644
--- a/services/java/com/android/server/MountService.java
+++ b/services/java/com/android/server/MountService.java
@@ -549,34 +549,6 @@ class MountService extends IMountService.Stub
         }
     }
 
-    private final BroadcastReceiver mBootReceiver = new BroadcastReceiver() {
-        @Override
-        public void onReceive(Context context, Intent intent) {
-            final int userId = intent.getIntExtra(Intent.EXTRA_USER_HANDLE, -1);
-            if (userId == -1) return;
-            final UserHandle user = new UserHandle(userId);
-
-            Slog.d(TAG, "BOOT_COMPLETED for " + user);
-
-            // Broadcast mounted volumes to newly booted user. This kicks off
-            // media scanner when a user becomes active.
-            synchronized (mVolumesLock) {
-                for (StorageVolume volume : mVolumes) {
-                    final UserHandle owner = volume.getOwner();
-                    final boolean ownerMatch = owner == null
-                            || owner.getIdentifier() == user.getIdentifier();
-
-                    final String state = mVolumeStates.get(volume.getPath());
-
-                    if (ownerMatch && (Environment.MEDIA_MOUNTED.equals(state)
-                            || Environment.MEDIA_MOUNTED_READ_ONLY.equals(state))) {
-                        sendStorageIntent(Intent.ACTION_MEDIA_MOUNTED, volume, user);
-                    }
-                }
-            }
-        }
-    };
-
     private final BroadcastReceiver mUserReceiver = new BroadcastReceiver() {
         @Override
         public void onReceive(Context context, Intent intent) {
@@ -1309,10 +1281,6 @@ class MountService extends IMountService.Stub
         mHandlerThread.start();
         mHandler = new MountServiceHandler(mHandlerThread.getLooper());
 
-        // Watch for user boot completion
-        mContext.registerReceiverAsUser(mBootReceiver, UserHandle.ALL,
-                new IntentFilter(Intent.ACTION_BOOT_COMPLETED), null, mHandler);
-
         // Watch for user changes
         final IntentFilter userFilter = new IntentFilter();
         userFilter.addAction(Intent.ACTION_USER_ADDED);