am 95661575: am 612aac4e: am c66b90fe: Merge "Generate stable MTP storage IDs." into mnc-dev

* commit '95661575a058f72ec6db5f455b6319816334a5ee':
  Generate stable MTP storage IDs.

core/java/android/os/storage/StorageVolume.java

@@ -58,6 +58,9 @@ public class StorageVolume implements Parcelable {
     // ACTION_MEDIA_BAD_REMOVAL, ACTION_MEDIA_UNMOUNTABLE and ACTION_MEDIA_EJECT broadcasts.
     public static final String EXTRA_STORAGE_VOLUME = "storage_volume";
 
+    public static final int STORAGE_ID_INVALID = 0x00000000;
+    public static final int STORAGE_ID_PRIMARY = 0x00010001;
+
     public StorageVolume(String id, int storageId, File path, String description, boolean primary,
             boolean removable, boolean emulated, long mtpReserveSize, boolean allowMassStorage,
             long maxFileSize, UserHandle owner, String fsUuid, String state) {

core/java/android/os/storage/VolumeInfo.java

@@ -147,15 +147,11 @@ public class VolumeInfo implements Parcelable {
     public String path;
     public String internalPath;
 
-    /** Framework state */
+    public VolumeInfo(String id, int type, DiskInfo disk, String partGuid) {
-    public final int mtpIndex;
-
-    public VolumeInfo(String id, int type, DiskInfo disk, String partGuid, int mtpIndex) {
         this.id = Preconditions.checkNotNull(id);
         this.type = type;
         this.disk = disk;
         this.partGuid = partGuid;
-        this.mtpIndex = mtpIndex;
     }
 
     public VolumeInfo(Parcel parcel) {
@@ -175,7 +171,6 @@ public class VolumeInfo implements Parcelable {
         fsLabel = parcel.readString();
         path = parcel.readString();
         internalPath = parcel.readString();
-        mtpIndex = parcel.readInt();
     }
 
     public static @NonNull String getEnvironmentForState(int state) {
@@ -308,7 +303,6 @@ public class VolumeInfo implements Parcelable {
         final boolean removable;
         final boolean emulated;
         final boolean allowMassStorage = false;
-        final int mtpStorageId = MtpStorage.getStorageIdForIndex(mtpIndex);
         final String envState = getEnvironmentForState(state);
 
         File userPath = getPathForUser(userId);
@@ -326,9 +320,15 @@ public class VolumeInfo implements Parcelable {
 
         long mtpReserveSize = 0;
         long maxFileSize = 0;
+        int mtpStorageId = StorageVolume.STORAGE_ID_INVALID;
 
         if (type == TYPE_EMULATED) {
             emulated = true;
+
+            if (isPrimary()) {
+                mtpStorageId = StorageVolume.STORAGE_ID_PRIMARY;
+            }
+
             mtpReserveSize = StorageManager.from(context).getStorageLowBytes(userPath);
 
             if (ID_EMULATED_INTERNAL.equals(id)) {
@@ -341,6 +341,14 @@ public class VolumeInfo implements Parcelable {
             emulated = false;
             removable = true;
 
+            if (isPrimary()) {
+                mtpStorageId = StorageVolume.STORAGE_ID_PRIMARY;
+            } else {
+                // Since MediaProvider currently persists this value, we need a
+                // value that is stable over time.
+                mtpStorageId = buildStableMtpStorageId(fsUuid);
+            }
+
             if ("vfat".equals(fsType)) {
                 maxFileSize = 4294967295L;
             }
@@ -354,6 +362,24 @@ public class VolumeInfo implements Parcelable {
                 fsUuid, envState);
     }
 
+    public static int buildStableMtpStorageId(String fsUuid) {
+        if (TextUtils.isEmpty(fsUuid)) {
+            return StorageVolume.STORAGE_ID_INVALID;
+        } else {
+            int hash = 0;
+            for (int i = 0; i < fsUuid.length(); ++i) {
+                hash = 31 * hash + fsUuid.charAt(i);
+            }
+            hash = (hash ^ (hash << 16)) & 0xffff0000;
+            // Work around values that the spec doesn't allow, or that we've
+            // reserved for primary
+            if (hash == 0x00000000) hash = 0x00020000;
+            if (hash == 0x00010000) hash = 0x00020000;
+            if (hash == 0xffff0000) hash = 0xfffe0000;
+            return hash | 0x0001;
+        }
+    }
+
     // TODO: avoid this layering violation
     private static final String DOCUMENT_AUTHORITY = "com.android.externalstorage.documents";
     private static final String DOCUMENT_ROOT_PRIMARY_EMULATED = "primary";
@@ -402,7 +428,6 @@ public class VolumeInfo implements Parcelable {
         pw.println();
         pw.printPair("path", path);
         pw.printPair("internalPath", internalPath);
-        pw.printPair("mtpIndex", mtpIndex);
         pw.decreaseIndent();
         pw.println();
     }
@@ -469,6 +494,5 @@ public class VolumeInfo implements Parcelable {
         parcel.writeString(fsLabel);
         parcel.writeString(path);
         parcel.writeString(internalPath);
-        parcel.writeInt(mtpIndex);
     }
 }

media/java/android/mtp/MtpStorage.java

@@ -53,18 +53,6 @@ public class MtpStorage {
         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 getStorageIdForIndex(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
      *

services/core/java/com/android/server/MountService.java

@@ -402,16 +402,6 @@ class MountService extends IMountService.Stub
         }
     }
 
-    private static int sNextMtpIndex = 1;
-
-    private static int allocateMtpIndex(String volId) {
-        if (VolumeInfo.ID_EMULATED_INTERNAL.equals(volId)) {
-            return 0;
-        } else {
-            return sNextMtpIndex++;
-        }
-    }
-
     /** List of crypto types.
       * These must match CRYPT_TYPE_XXX in cryptfs.h AND their
       * corresponding commands in CommandListener.cpp */
@@ -742,7 +732,7 @@ class MountService extends IMountService.Stub
 
             // Create a stub volume that represents internal storage
             final VolumeInfo internal = new VolumeInfo(VolumeInfo.ID_PRIVATE_INTERNAL,
-                    VolumeInfo.TYPE_PRIVATE, null, null, 0);
+                    VolumeInfo.TYPE_PRIVATE, null, null);
             internal.state = VolumeInfo.STATE_MOUNTED;
             internal.path = Environment.getDataDirectory().getAbsolutePath();
             mVolumes.put(internal.id, internal);
@@ -967,8 +957,7 @@ class MountService extends IMountService.Stub
                 final String partGuid = TextUtils.nullIfEmpty(cooked[4]);
 
                 final DiskInfo disk = mDisks.get(diskId);
-                final int mtpIndex = allocateMtpIndex(id);
+                final VolumeInfo vol = new VolumeInfo(id, type, disk, partGuid);
-                final VolumeInfo vol = new VolumeInfo(id, type, disk, partGuid, mtpIndex);
                 mVolumes.put(id, vol);
                 onVolumeCreatedLocked(vol);
                 break;
@@ -2604,7 +2593,7 @@ class MountService extends IMountService.Stub
             final String uuid = null;
             final String state = Environment.MEDIA_REMOVED;
 
-            res.add(0, new StorageVolume(id, MtpStorage.getStorageIdForIndex(0), path,
+            res.add(0, new StorageVolume(id, StorageVolume.STORAGE_ID_INVALID, path,
                     description, primary, removable, emulated, mtpReserveSize,
                     allowMassStorage, maxFileSize, owner, uuid, state));
         }