From 7ae938be1b4fb8938f0f438cfd611cd9ed0da513 Mon Sep 17 00:00:00 2001
From: Mike Lockwood <lockwood@android.com>
Date: Tue, 5 Apr 2011 10:21:27 -0400
Subject: [PATCH] DO NOT MERGE MTP and media provider support for multiple
 storage devices:

- MTP support for multiple storage units

- Add storage_id column to media database for MTP storage ID

- Add framework resource for defining mount points and user visible descriptions
for multiple volumes

- Clean up locking in MtpServer JNI code

Change-Id: Ide6d47bd9aa1698ed2a13d695613e03f2a9b29e3
Signed-off-by: Mike Lockwood <lockwood@android.com>
---
 core/java/android/provider/MediaStore.java   |   7 +
 core/res/res/values/config.xml               |  17 ++
 media/java/android/mtp/MtpDatabase.java      |  78 ++++----
 media/java/android/mtp/MtpPropertyGroup.java |  11 +-
 media/java/android/mtp/MtpServer.java        |  20 ++-
 media/java/android/mtp/MtpStorage.java       |  89 ++++++++++
 media/jni/android_mtp_MtpServer.cpp          | 177 +++++++++++++------
 media/mtp/MtpServer.h                        |   6 +-
 media/mtp/MtpStorage.cpp                     |   6 +-
 media/mtp/MtpStorage.h                       |   3 +-
 media/mtp/mtp.h                              |   2 -
 11 files changed, 312 insertions(+), 104 deletions(-)
 create mode 100644 media/java/android/mtp/MtpStorage.java

diff --git a/core/java/android/provider/MediaStore.java b/core/java/android/provider/MediaStore.java
index b59421e288583..c9b2f973aacad 100644
--- a/core/java/android/provider/MediaStore.java
+++ b/core/java/android/provider/MediaStore.java
@@ -343,6 +343,13 @@ public final class MediaStore {
          * Table also contains MediaColumns._ID, DATA, SIZE and DATE_MODIFIED.
          */
         public interface FileColumns extends MediaColumns {
+            /**
+             * The MTP storage ID of the file
+             * <P>Type: INTEGER</P>
+             * @hide
+             */
+            public static final String STORAGE_ID = "storage_id";
+
             /**
              * The MTP format code of the file
              * <P>Type: INTEGER</P>
diff --git a/core/res/res/values/config.xml b/core/res/res/values/config.xml
index e46eeccf073e6..27c7a4d1a602a 100644
--- a/core/res/res/values/config.xml
+++ b/core/res/res/values/config.xml
@@ -109,6 +109,23 @@
          removable. -->
     <bool name="config_externalStorageRemovable" product="default">true</bool>
 
+    <!-- List of mount points for external storage devices.
+         The first item on the list should be the primary external storage and should match the
+         value returned by Environment.getExternalStorageDirectory (/mnt/sdcard).
+         MTP storage IDs will be generated based on the position of the mountpoint in this list:
+            0x00010001 - ID for primary external storage (/mnt/sdcard)
+            0x00020001 - ID for first secondary external storage
+            0x00030001 - ID for second secondary external storage
+         etc. -->
+    <string-array translatable="false" name="config_externalStoragePaths">
+        <item>"/mnt/sdcard"</item>
+    </string-array>
+
+    <!-- User visible descriptions of the volumes in the config_externalStoragePaths array. -->
+    <string-array translatable="true" name="config_externalStorageDescriptions">
+        <item>"SD card"</item>
+    </string-array>
+
     <!-- Number of megabytes of space to leave unallocated by MTP.
          MTP will subtract this value from the free space it reports back
          to the host via GetStorageInfo, and will not allow new files to
diff --git a/media/java/android/mtp/MtpDatabase.java b/media/java/android/mtp/MtpDatabase.java
index b4a46891f95a6..b900671c22fc0 100644
--- a/media/java/android/mtp/MtpDatabase.java
+++ b/media/java/android/mtp/MtpDatabase.java
@@ -50,7 +50,8 @@ public class MtpDatabase {
     private final IContentProvider mMediaProvider;
     private final String mVolumeName;
     private final Uri mObjectsUri;
-    private final String mMediaStoragePath;
+    private final String mMediaStoragePath; // path to primary storage
+    private final HashMap<String, MtpStorage> mStorageMap = new HashMap<String, MtpStorage>();
 
     // cached property groups for single properties
     private final HashMap<Integer, MtpPropertyGroup> mPropertyGroupsByProperty
@@ -67,9 +68,6 @@ public class MtpDatabase {
     private SharedPreferences mDeviceProperties;
     private static final int DEVICE_PROPERTIES_DATABASE_VERSION = 1;
 
-    // FIXME - this should be passed in via the constructor
-    private final int mStorageID = 0x00010001;
-
     private static final String[] ID_PROJECTION = new String[] {
             Files.FileColumns._ID, // 0
     };
@@ -85,17 +83,22 @@ public class MtpDatabase {
     };
     private static final String[] OBJECT_INFO_PROJECTION = new String[] {
             Files.FileColumns._ID, // 0
-            Files.FileColumns.DATA, // 1
+            Files.FileColumns.STORAGE_ID, // 1
             Files.FileColumns.FORMAT, // 2
             Files.FileColumns.PARENT, // 3
-            Files.FileColumns.SIZE, // 4
-            Files.FileColumns.DATE_MODIFIED, // 5
+            Files.FileColumns.DATA, // 4
+            Files.FileColumns.SIZE, // 5
+            Files.FileColumns.DATE_MODIFIED, // 6
     };
     private static final String ID_WHERE = Files.FileColumns._ID + "=?";
     private static final String PATH_WHERE = Files.FileColumns.DATA + "=?";
     private static final String PARENT_WHERE = Files.FileColumns.PARENT + "=?";
     private static final String PARENT_FORMAT_WHERE = PARENT_WHERE + " AND "
                                             + Files.FileColumns.FORMAT + "=?";
+    private static final String PARENT_STORAGE_WHERE = PARENT_WHERE + " AND "
+                                            + Files.FileColumns.STORAGE_ID + "=?";
+    private static final String PARENT_STORAGE_FORMAT_WHERE = PARENT_STORAGE_WHERE + " AND "
+                                            + Files.FileColumns.FORMAT + "=?";
 
     private final MediaScanner mMediaScanner;
 
@@ -124,6 +127,14 @@ public class MtpDatabase {
         }
     }
 
+    public void addStorage(MtpStorage storage) {
+        mStorageMap.put(storage.getPath(), storage);
+    }
+
+    public void removeStorage(MtpStorage storage) {
+        mStorageMap.remove(storage.getPath());
+    }
+
     private void initDeviceProperties(Context context) {
         final String devicePropertiesName = "device-properties";
         mDeviceProperties = context.getSharedPreferences(devicePropertiesName, Context.MODE_PRIVATE);
@@ -160,7 +171,7 @@ public class MtpDatabase {
     }
 
     private int beginSendObject(String path, int format, int parent,
-                         int storage, long size, long modified) {
+                         int storageId, long size, long modified) {
         // first make sure the object does not exist
         if (path != null) {
             Cursor c = null;
@@ -185,7 +196,7 @@ public class MtpDatabase {
         values.put(Files.FileColumns.DATA, path);
         values.put(Files.FileColumns.FORMAT, format);
         values.put(Files.FileColumns.PARENT, parent);
-        // storage is ignored for now
+        values.put(Files.FileColumns.STORAGE_ID, storageId);
         values.put(Files.FileColumns.SIZE, size);
         values.put(Files.FileColumns.DATE_MODIFIED, modified);
 
@@ -237,19 +248,35 @@ public class MtpDatabase {
         }
     }
 
-    private int[] getObjectList(int storageID, int format, int parent) {
-        // we can ignore storageID until we support multiple storages
-        Cursor c = null;
-        try {
+    private Cursor createObjectQuery(int storageID, int format, int parent) throws RemoteException {
+        if (storageID != 0) {
             if (format != 0) {
-                c = mMediaProvider.query(mObjectsUri, ID_PROJECTION,
+                return mMediaProvider.query(mObjectsUri, ID_PROJECTION,
+                        PARENT_STORAGE_FORMAT_WHERE,
+                        new String[] { Integer.toString(parent), Integer.toString(storageID),
+                                Integer.toString(format) }, null);
+            } else {
+                return mMediaProvider.query(mObjectsUri, ID_PROJECTION,
+                        PARENT_STORAGE_WHERE, new String[]
+                                { Integer.toString(parent), Integer.toString(storageID) }, null);
+            }
+        } else {
+            if (format != 0) {
+                return mMediaProvider.query(mObjectsUri, ID_PROJECTION,
                             PARENT_FORMAT_WHERE,
                             new String[] { Integer.toString(parent), Integer.toString(format) },
                              null);
             } else {
-                c = mMediaProvider.query(mObjectsUri, ID_PROJECTION,
+                return mMediaProvider.query(mObjectsUri, ID_PROJECTION,
                             PARENT_WHERE, new String[] { Integer.toString(parent) }, null);
             }
+        }
+    }
+
+    private int[] getObjectList(int storageID, int format, int parent) {
+        Cursor c = null;
+        try {
+            c = createObjectQuery(storageID, format, parent);
             if (c == null) {
                 return null;
             }
@@ -273,18 +300,9 @@ public class MtpDatabase {
     }
 
     private int getNumObjects(int storageID, int format, int parent) {
-        // we can ignore storageID until we support multiple storages
         Cursor c = null;
         try {
-            if (format != 0) {
-                c = mMediaProvider.query(mObjectsUri, ID_PROJECTION,
-                            PARENT_FORMAT_WHERE,
-                            new String[] { Integer.toString(parent), Integer.toString(format) },
-                             null);
-            } else {
-                c = mMediaProvider.query(mObjectsUri, ID_PROJECTION,
-                            PARENT_WHERE, new String[] { Integer.toString(parent) }, null);
-            }
+            c = createObjectQuery(storageID, format, parent);
             if (c != null) {
                 return c.getCount();
             }
@@ -508,7 +526,7 @@ public class MtpDatabase {
             }
         }
 
-        return propertyGroup.getPropertyList((int)handle, format, depth, mStorageID);
+        return propertyGroup.getPropertyList((int)handle, format, depth);
     }
 
     private int renameFile(int handle, String newName) {
@@ -631,12 +649,12 @@ public class MtpDatabase {
             c = mMediaProvider.query(mObjectsUri, OBJECT_INFO_PROJECTION,
                             ID_WHERE, new String[] {  Integer.toString(handle) }, null);
             if (c != null && c.moveToNext()) {
-                outStorageFormatParent[0] = mStorageID;
+                outStorageFormatParent[0] = c.getInt(1);
                 outStorageFormatParent[1] = c.getInt(2);
                 outStorageFormatParent[2] = c.getInt(3);
 
                 // extract name from path
-                String path = c.getString(1);
+                String path = c.getString(4);
                 int lastSlash = path.lastIndexOf('/');
                 int start = (lastSlash >= 0 ? lastSlash + 1 : 0);
                 int end = path.length();
@@ -646,8 +664,8 @@ public class MtpDatabase {
                 path.getChars(start, end, outName, 0);
                 outName[end - start] = 0;
 
-                outSizeModified[0] = c.getLong(4);
-                outSizeModified[1] = c.getLong(5);
+                outSizeModified[0] = c.getLong(5);
+                outSizeModified[1] = c.getLong(6);
                 return true;
             }
         } catch (RemoteException e) {
diff --git a/media/java/android/mtp/MtpPropertyGroup.java b/media/java/android/mtp/MtpPropertyGroup.java
index fceedd28e0406..b75b11a0ff990 100644
--- a/media/java/android/mtp/MtpPropertyGroup.java
+++ b/media/java/android/mtp/MtpPropertyGroup.java
@@ -93,7 +93,7 @@ class MtpPropertyGroup {
 
          switch (code) {
             case MtpConstants.PROPERTY_STORAGE_ID:
-                // no query needed until we support multiple storage units
+                column = Files.FileColumns.STORAGE_ID;
                 type = MtpConstants.TYPE_UINT32;
                 break;
              case MtpConstants.PROPERTY_OBJECT_FORMAT:
@@ -134,6 +134,7 @@ class MtpPropertyGroup {
                 break;
             case MtpConstants.PROPERTY_PERSISTENT_UID:
                 // PUID is concatenation of storageID and object handle
+                column = Files.FileColumns.STORAGE_ID;
                 type = MtpConstants.TYPE_UINT128;
                 break;
             case MtpConstants.PROPERTY_DURATION:
@@ -280,7 +281,7 @@ class MtpPropertyGroup {
         return path.substring(start, end);
     }
 
-    MtpPropertyList getPropertyList(int handle, int format, int depth, int storageID) {
+    MtpPropertyList getPropertyList(int handle, int format, int depth) {
         //Log.d(TAG, "getPropertyList handle: " + handle + " format: " + format + " depth: " + depth);
         if (depth > 1) {
             // we only support depth 0 and 1
@@ -348,10 +349,6 @@ class MtpPropertyGroup {
 
                     // handle some special cases
                     switch (propertyCode) {
-                        case MtpConstants.PROPERTY_STORAGE_ID:
-                            result.append(handle, propertyCode, MtpConstants.TYPE_UINT32,
-                                    storageID);
-                            break;
                         case MtpConstants.PROPERTY_PROTECTION_STATUS:
                             // protection status is always 0
                             result.append(handle, propertyCode, MtpConstants.TYPE_UINT16, 0);
@@ -398,7 +395,7 @@ class MtpPropertyGroup {
                             break;
                         case MtpConstants.PROPERTY_PERSISTENT_UID:
                             // PUID is concatenation of storageID and object handle
-                            long puid = storageID;
+                            long puid = c.getLong(column);
                             puid <<= 32;
                             puid += handle;
                             result.append(handle, propertyCode, MtpConstants.TYPE_UINT128, puid);
diff --git a/media/java/android/mtp/MtpServer.java b/media/java/android/mtp/MtpServer.java
index 006fa6d22aa28..c065ca842b237 100644
--- a/media/java/android/mtp/MtpServer.java
+++ b/media/java/android/mtp/MtpServer.java
@@ -33,8 +33,8 @@ public class MtpServer {
         System.loadLibrary("media_jni");
     }
 
-    public MtpServer(MtpDatabase database, String storagePath, long reserveSpace) {
-        native_setup(database, storagePath, reserveSpace);
+    public MtpServer(MtpDatabase database) {
+        native_setup(database);
     }
 
     public void start() {
@@ -65,18 +65,20 @@ public class MtpServer {
         native_set_ptp_mode(usePtp);
     }
 
-    // Used to disable MTP by removing all storage units.
-    // This is done to disable access to file transfer when the device is locked.
-    public void setLocked(boolean locked) {
-        native_set_locked(locked);
+    public void addStorage(MtpStorage storage) {
+        native_add_storage(storage);
     }
 
-    private native final void native_setup(MtpDatabase database, String storagePath,
-            long reserveSpace);
+    public void removeStorage(MtpStorage storage) {
+        native_remove_storage(storage.getStorageId());
+    }
+
+    private native final void native_setup(MtpDatabase database);
     private native final void native_start();
     private native final void native_stop();
     private native final void native_send_object_added(int handle);
     private native final void native_send_object_removed(int handle);
     private native final void native_set_ptp_mode(boolean usePtp);
-    private native final void native_set_locked(boolean locked);
+    private native final void native_add_storage(MtpStorage storage);
+    private native final void native_remove_storage(int storageId);
 }
diff --git a/media/java/android/mtp/MtpStorage.java b/media/java/android/mtp/MtpStorage.java
new file mode 100644
index 0000000000000..33146e7dadb43
--- /dev/null
+++ b/media/java/android/mtp/MtpStorage.java
@@ -0,0 +1,89 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.mtp;
+
+/**
+ * This class represents a storage unit on an MTP device.
+ * Used only for MTP support in USB responder mode.
+ * MtpStorageInfo is used in MTP host mode
+ *
+ * @hide
+ */
+public class MtpStorage {
+
+    private final int mStorageId;
+    private final String mPath;
+    private final String mDescription;
+    private final long mReserveSpace;
+
+    public MtpStorage(int id, String path, String description, long reserveSpace) {
+        mStorageId = id;
+        mPath = path;
+        mDescription = description;
+        mReserveSpace = reserveSpace;
+    }
+
+    /**
+     * Returns the storage ID for the storage unit
+     *
+     * @return the storage ID
+     */
+    public final int getStorageId() {
+        return mStorageId;
+    }
+
+    /**
+     * Generates a storage ID for storage of given index.
+     * Index 0 is for primary external storage
+     *
+     * @return the storage ID
+     */
+    public static int getStorageId(int index) {
+        // storage ID is 0x00010001 for primary storage,
+        // then 0x00020001, 0x00030001, etc. for secondary storages
+        return ((index + 1) << 16) + 1;
+    }
+
+   /**
+     * Returns the file path for the storage unit's storage in the file system
+     *
+     * @return the storage file path
+     */
+    public final String getPath() {
+        return mPath;
+    }
+
+   /**
+     * Returns the description string for the storage unit
+     *
+     * @return the storage unit description
+     */
+    public final String getDescription() {
+        return mDescription;
+    }
+
+   /**
+     * Returns the amount of space to reserve on the storage file system.
+     * This can be set to a non-zero value to prevent MTP from filling up the entire storage.
+     *
+     * @return the storage unit description
+     */
+    public final long getReserveSpace() {
+        return mReserveSpace;
+    }
+
+}
diff --git a/media/jni/android_mtp_MtpServer.cpp b/media/jni/android_mtp_MtpServer.cpp
index e025ef1acff8c..c55189f3491da 100644
--- a/media/jni/android_mtp_MtpServer.cpp
+++ b/media/jni/android_mtp_MtpServer.cpp
@@ -39,6 +39,17 @@
 
 using namespace android;
 
+// MtpStorage class
+jclass clazz_MtpStorage;
+
+// MtpStorage fields
+static jfieldID field_MtpStorage_storageId;
+static jfieldID field_MtpStorage_path;
+static jfieldID field_MtpStorage_description;
+static jfieldID field_MtpStorage_reserveSpace;
+
+static Mutex sMutex;
+
 // ----------------------------------------------------------------------------
 
 // in android_mtp_MtpDatabase.cpp
@@ -57,70 +68,77 @@ class MtpThread : public Thread {
 private:
     MtpDatabase*    mDatabase;
     MtpServer*      mServer;
-    MtpStorage*     mStorage;
-    Mutex           mMutex;
+    MtpStorageList  mStorageList;
     bool            mUsePtp;
-    bool            mLocked;
     int             mFd;
 
 public:
-    MtpThread(MtpDatabase* database, MtpStorage* storage)
+    MtpThread(MtpDatabase* database)
         :   mDatabase(database),
             mServer(NULL),
-            mStorage(storage),
             mUsePtp(false),
-            mLocked(false),
             mFd(-1)
     {
     }
 
     virtual ~MtpThread() {
-        delete mStorage;
     }
 
     void setPtpMode(bool usePtp) {
-        mMutex.lock();
         mUsePtp = usePtp;
-        mMutex.unlock();
     }
 
-    void setLocked(bool locked) {
-        mMutex.lock();
-        if (locked != mLocked) {
-            if (mServer) {
-                if (locked)
-                    mServer->removeStorage(mStorage);
-                else
-                    mServer->addStorage(mStorage);
+    void addStorage(MtpStorage *storage) {
+        mStorageList.push(storage);
+        if (mServer)
+            mServer->addStorage(storage);
+    }
+
+    void removeStorage(MtpStorageID id) {
+        MtpStorage* storage = mServer->getStorage(id);
+        if (storage) {
+            for (int i = 0; i < mStorageList.size(); i++) {
+                if (mStorageList[i] == storage) {
+                    mStorageList.removeAt(i);
+                    break;
+                }
             }
-            mLocked = locked;
+            if (mServer)
+                mServer->removeStorage(storage);
+            delete storage;
         }
-        mMutex.unlock();
+    }
+
+    void start() {
+        run("MtpThread");
     }
 
     virtual bool threadLoop() {
-        mMutex.lock();
+        sMutex.lock();
+
         mFd = open("/dev/mtp_usb", O_RDWR);
         if (mFd >= 0) {
             ioctl(mFd, MTP_SET_INTERFACE_MODE,
                     (mUsePtp ? MTP_INTERFACE_MODE_PTP : MTP_INTERFACE_MODE_MTP));
 
             mServer = new MtpServer(mFd, mDatabase, AID_MEDIA_RW, 0664, 0775);
-            if (!mLocked)
-                mServer->addStorage(mStorage);
-
-            mMutex.unlock();
-            mServer->run();
-            mMutex.lock();
-
-            close(mFd);
-            mFd = -1;
-            delete mServer;
-            mServer = NULL;
+            for (int i = 0; i < mStorageList.size(); i++) {
+                mServer->addStorage(mStorageList[i]);
+            }
         } else {
             LOGE("could not open MTP driver, errno: %d", errno);
         }
-        mMutex.unlock();
+
+        sMutex.unlock();
+        mServer->run();
+        sMutex.lock();
+
+        close(mFd);
+        mFd = -1;
+        delete mServer;
+        mServer = NULL;
+
+        sMutex.unlock();
         // delay a bit before retrying to avoid excessive spin
         if (!exitPending()) {
             sleep(1);
@@ -130,17 +148,13 @@ public:
     }
 
     void sendObjectAdded(MtpObjectHandle handle) {
-        mMutex.lock();
         if (mServer)
             mServer->sendObjectAdded(handle);
-        mMutex.unlock();
     }
 
     void sendObjectRemoved(MtpObjectHandle handle) {
-        mMutex.lock();
         if (mServer)
             mServer->sendObjectRemoved(handle);
-        mMutex.unlock();
     }
 };
 
@@ -150,18 +164,11 @@ static sp<MtpThread> sThread;
 #endif // HAVE_ANDROID_OS
 
 static void
-android_mtp_MtpServer_setup(JNIEnv *env, jobject thiz, jobject javaDatabase,
-        jstring storagePath, jlong reserveSpace)
+android_mtp_MtpServer_setup(JNIEnv *env, jobject thiz, jobject javaDatabase)
 {
 #ifdef HAVE_ANDROID_OS
-    MtpDatabase* database = getMtpDatabase(env, javaDatabase);
-    const char *storagePathStr = env->GetStringUTFChars(storagePath, NULL);
-
     // create the thread and assign it to the smart pointer
-    MtpStorage* storage = new MtpStorage(MTP_FIRST_STORAGE_ID, storagePathStr, reserveSpace);
-    sThread = new MtpThread(database, storage);
-
-    env->ReleaseStringUTFChars(storagePath, storagePathStr);
+    sThread = new MtpThread(getMtpDatabase(env, javaDatabase));
 #endif
 }
 
@@ -169,9 +176,11 @@ static void
 android_mtp_MtpServer_start(JNIEnv *env, jobject thiz)
 {
 #ifdef HAVE_ANDROID_OS
+   sMutex.lock();
     MtpThread *thread = sThread.get();
     if (thread)
-        thread->run("MtpThread");
+        thread->start();
+    sMutex.unlock();
 #endif // HAVE_ANDROID_OS
 }
 
@@ -179,11 +188,13 @@ static void
 android_mtp_MtpServer_stop(JNIEnv *env, jobject thiz)
 {
 #ifdef HAVE_ANDROID_OS
+    sMutex.lock();
     MtpThread *thread = sThread.get();
     if (thread) {
         thread->requestExitAndWait();
         sThread = NULL;
     }
+    sMutex.unlock();
 #endif
 }
 
@@ -191,9 +202,11 @@ static void
 android_mtp_MtpServer_send_object_added(JNIEnv *env, jobject thiz, jint handle)
 {
 #ifdef HAVE_ANDROID_OS
+    sMutex.lock();
     MtpThread *thread = sThread.get();
     if (thread)
         thread->sendObjectAdded(handle);
+    sMutex.unlock();
 #endif
 }
 
@@ -201,9 +214,11 @@ static void
 android_mtp_MtpServer_send_object_removed(JNIEnv *env, jobject thiz, jint handle)
 {
 #ifdef HAVE_ANDROID_OS
+    sMutex.lock();
     MtpThread *thread = sThread.get();
     if (thread)
         thread->sendObjectRemoved(handle);
+    sMutex.unlock();
 #endif
 }
 
@@ -211,33 +226,68 @@ static void
 android_mtp_MtpServer_set_ptp_mode(JNIEnv *env, jobject thiz, jboolean usePtp)
 {
 #ifdef HAVE_ANDROID_OS
+    sMutex.lock();
     MtpThread *thread = sThread.get();
     if (thread)
         thread->setPtpMode(usePtp);
+    sMutex.unlock();
 #endif
 }
 
 static void
-android_mtp_MtpServer_set_locked(JNIEnv *env, jobject thiz, jboolean locked)
+android_mtp_MtpServer_add_storage(JNIEnv *env, jobject thiz, jobject jstorage)
 {
 #ifdef HAVE_ANDROID_OS
+    sMutex.lock();
+    MtpThread *thread = sThread.get();
+    if (thread) {
+        jint storageID = env->GetIntField(jstorage, field_MtpStorage_storageId);
+        jstring path = (jstring)env->GetObjectField(jstorage, field_MtpStorage_path);
+        jstring description = (jstring)env->GetObjectField(jstorage, field_MtpStorage_description);
+        jlong reserveSpace = env->GetLongField(jstorage, field_MtpStorage_reserveSpace);
+
+        const char *pathStr = env->GetStringUTFChars(path, NULL);
+        const char *descriptionStr = env->GetStringUTFChars(description, NULL);
+
+        MtpStorage* storage = new MtpStorage(storageID, pathStr, descriptionStr, reserveSpace);
+        thread->addStorage(storage);
+
+        env->ReleaseStringUTFChars(path, pathStr);
+        env->ReleaseStringUTFChars(description, descriptionStr);
+    } else {
+        LOGE("MtpThread is null in add_storage");
+    }
+    sMutex.unlock();
+#endif
+}
+
+static void
+android_mtp_MtpServer_remove_storage(JNIEnv *env, jobject thiz, jint storageId)
+{
+#ifdef HAVE_ANDROID_OS
+    sMutex.lock();
     MtpThread *thread = sThread.get();
     if (thread)
-        thread->setLocked(locked);
+        thread->removeStorage(storageId);
+    else
+        LOGE("MtpThread is null in remove_storage");
+    sMutex.unlock();
 #endif
 }
 
 // ----------------------------------------------------------------------------
 
 static JNINativeMethod gMethods[] = {
-    {"native_setup",                "(Landroid/mtp/MtpDatabase;Ljava/lang/String;J)V",
+    {"native_setup",                "(Landroid/mtp/MtpDatabase;)V",
                                             (void *)android_mtp_MtpServer_setup},
     {"native_start",                "()V",  (void *)android_mtp_MtpServer_start},
     {"native_stop",                 "()V",  (void *)android_mtp_MtpServer_stop},
     {"native_send_object_added",    "(I)V", (void *)android_mtp_MtpServer_send_object_added},
     {"native_send_object_removed",  "(I)V", (void *)android_mtp_MtpServer_send_object_removed},
     {"native_set_ptp_mode",         "(Z)V", (void *)android_mtp_MtpServer_set_ptp_mode},
-    {"native_set_locked",           "(Z)V", (void *)android_mtp_MtpServer_set_locked},
+    {"native_add_storage",          "(Landroid/mtp/MtpStorage;)V",
+                                            (void *)android_mtp_MtpServer_add_storage},
+    {"native_remove_storage",       "(I)V", (void *)android_mtp_MtpServer_remove_storage},
 };
 
 static const char* const kClassPathName = "android/mtp/MtpServer";
@@ -246,6 +296,33 @@ int register_android_mtp_MtpServer(JNIEnv *env)
 {
     jclass clazz;
 
+    clazz = env->FindClass("android/mtp/MtpStorage");
+    if (clazz == NULL) {
+        LOGE("Can't find android/mtp/MtpStorage");
+        return -1;
+    }
+    field_MtpStorage_storageId = env->GetFieldID(clazz, "mStorageId", "I");
+    if (field_MtpStorage_storageId == NULL) {
+        LOGE("Can't find MtpStorage.mStorageId");
+        return -1;
+    }
+    field_MtpStorage_path = env->GetFieldID(clazz, "mPath", "Ljava/lang/String;");
+    if (field_MtpStorage_path == NULL) {
+        LOGE("Can't find MtpStorage.mPath");
+        return -1;
+    }
+    field_MtpStorage_description = env->GetFieldID(clazz, "mDescription", "Ljava/lang/String;");
+    if (field_MtpStorage_description == NULL) {
+        LOGE("Can't find MtpStorage.mDescription");
+        return -1;
+    }
+    field_MtpStorage_reserveSpace = env->GetFieldID(clazz, "mReserveSpace", "J");
+    if (field_MtpStorage_reserveSpace == NULL) {
+        LOGE("Can't find MtpStorage.mStorageId");
+        return -1;
+    }
+    clazz_MtpStorage = (jclass)env->NewGlobalRef(clazz);
+
     clazz = env->FindClass("android/mtp/MtpServer");
     if (clazz == NULL) {
         LOGE("Can't find android/mtp/MtpServer");
diff --git a/media/mtp/MtpServer.h b/media/mtp/MtpServer.h
index 1efa7158baa65..fa729a893bc07 100644
--- a/media/mtp/MtpServer.h
+++ b/media/mtp/MtpServer.h
@@ -70,6 +70,9 @@ public:
                                     int fileGroup, int filePerm, int directoryPerm);
     virtual             ~MtpServer();
 
+    MtpStorage*         getStorage(MtpStorageID id);
+    inline bool         hasStorage() { return mStorages.size() > 0; }
+    bool                hasStorage(MtpStorageID id);
     void                addStorage(MtpStorage* storage);
     void                removeStorage(MtpStorage* storage);
 
@@ -79,9 +82,6 @@ public:
     void                sendObjectRemoved(MtpObjectHandle handle);
 
 private:
-    MtpStorage*         getStorage(MtpStorageID id);
-    inline bool         hasStorage() { return mStorages.size() > 0; }
-    bool                hasStorage(MtpStorageID id);
     void                sendStoreAdded(MtpStorageID id);
     void                sendStoreRemoved(MtpStorageID id);
     void                sendEvent(MtpEventCode code, uint32_t param1);
diff --git a/media/mtp/MtpStorage.cpp b/media/mtp/MtpStorage.cpp
index 6cb88b33551f8..fff0b5f27ccdc 100644
--- a/media/mtp/MtpStorage.cpp
+++ b/media/mtp/MtpStorage.cpp
@@ -32,9 +32,11 @@
 
 namespace android {
 
-MtpStorage::MtpStorage(MtpStorageID id, const char* filePath, uint64_t reserveSpace)
+MtpStorage::MtpStorage(MtpStorageID id, const char* filePath,
+        const char* description, uint64_t reserveSpace)
     :   mStorageID(id),
         mFilePath(filePath),
+        mDescription(description),
         mMaxCapacity(0),
         mReserveSpace(reserveSpace)
 {
@@ -75,7 +77,7 @@ uint64_t MtpStorage::getFreeSpace() {
 }
 
 const char* MtpStorage::getDescription() const {
-    return "Device Storage";
+    return (const char *)mDescription;
 }
 
 }  // namespace android
diff --git a/media/mtp/MtpStorage.h b/media/mtp/MtpStorage.h
index 858c9d38a3f6b..d6ad25f33abb5 100644
--- a/media/mtp/MtpStorage.h
+++ b/media/mtp/MtpStorage.h
@@ -29,13 +29,14 @@ class MtpStorage {
 private:
     MtpStorageID            mStorageID;
     MtpString               mFilePath;
+    MtpString               mDescription;
     uint64_t                mMaxCapacity;
     // amount of free space to leave unallocated
     uint64_t                mReserveSpace;
 
 public:
                             MtpStorage(MtpStorageID id, const char* filePath,
-                                    uint64_t reserveSpace);
+                                    const char* description, uint64_t reserveSpace);
     virtual                 ~MtpStorage();
 
     inline MtpStorageID     getStorageID() const { return mStorageID; }
diff --git a/media/mtp/mtp.h b/media/mtp/mtp.h
index 6fedc161b9c19..8bc2e22c31d8a 100644
--- a/media/mtp/mtp.h
+++ b/media/mtp/mtp.h
@@ -22,8 +22,6 @@
 
 #define MTP_STANDARD_VERSION            100
 
-#define MTP_FIRST_STORAGE_ID            0x00010001
-
 // Container Types
 #define MTP_CONTAINER_TYPE_UNDEFINED    0
 #define MTP_CONTAINER_TYPE_COMMAND      1