Forget private partition keys.

When we forget a private partition, ask vold to also forget the key
for that partition GUID.  This means we need to track both the
filesystem UUID and the partition GUID for a private volume.

Bug: 21782268
Change-Id: Icda1cbb65539d61dacc663428daf3d1a2e4c313e

4 files changed, 51 insertions, 10 deletions

diff --git a/core/java/android/os/storage/VolumeInfo.java b/core/java/android/os/storage/VolumeInfo.java
index 8d11527..e33baa9 100644
--- a/core/java/android/os/storage/VolumeInfo.java
+++ b/core/java/android/os/storage/VolumeInfo.java
@@ -137,6 +137,7 @@ public class VolumeInfo implements Parcelable {
     public final String id;
     public final int type;
     public final DiskInfo disk;
+    public final String partGuid;
     public int mountFlags = 0;
     public int mountUserId = -1;
     public int state = STATE_UNMOUNTED;
@@ -149,10 +150,11 @@ public class VolumeInfo implements Parcelable {
     /** Framework state */
     public final int mtpIndex;
 
-    public VolumeInfo(String id, int type, DiskInfo disk, 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;
     }
 
@@ -164,6 +166,7 @@ public class VolumeInfo implements Parcelable {
         } else {
             disk = null;
         }
+        partGuid = parcel.readString();
         mountFlags = parcel.readInt();
         mountUserId = parcel.readInt();
         state = parcel.readInt();
@@ -385,6 +388,7 @@ public class VolumeInfo implements Parcelable {
         pw.increaseIndent();
         pw.printPair("type", DebugUtils.valueToString(getClass(), "TYPE_", type));
         pw.printPair("diskId", getDiskId());
+        pw.printPair("partGuid", partGuid);
         pw.printPair("mountFlags", DebugUtils.flagsToString(getClass(), "MOUNT_FLAG_", mountFlags));
         pw.printPair("mountUserId", mountUserId);
         pw.printPair("state", DebugUtils.valueToString(getClass(), "STATE_", state));
@@ -453,6 +457,7 @@ public class VolumeInfo implements Parcelable {
         } else {
             parcel.writeInt(0);
         }
+        parcel.writeString(partGuid);
         parcel.writeInt(mountFlags);
         parcel.writeInt(mountUserId);
         parcel.writeInt(state);
diff --git a/core/java/android/os/storage/VolumeRecord.java b/core/java/android/os/storage/VolumeRecord.java
index 096e2dd..cb16305 100644
--- a/core/java/android/os/storage/VolumeRecord.java
+++ b/core/java/android/os/storage/VolumeRecord.java
@@ -39,6 +39,7 @@ public class VolumeRecord implements Parcelable {
 
     public final int type;
     public final String fsUuid;
+    public String partGuid;
     public String nickname;
     public int userFlags;
 
@@ -50,6 +51,7 @@ public class VolumeRecord implements Parcelable {
     public VolumeRecord(Parcel parcel) {
         type = parcel.readInt();
         fsUuid = parcel.readString();
+        partGuid = parcel.readString();
         nickname = parcel.readString();
         userFlags = parcel.readInt();
     }
@@ -79,6 +81,8 @@ public class VolumeRecord implements Parcelable {
         pw.increaseIndent();
         pw.printPair("type", DebugUtils.valueToString(VolumeInfo.class, "TYPE_", type));
         pw.printPair("fsUuid", fsUuid);
+        pw.printPair("partGuid", partGuid);
+        pw.println();
         pw.printPair("nickname", nickname);
         pw.printPair("userFlags",
                 DebugUtils.flagsToString(VolumeRecord.class, "USER_FLAG_", userFlags));
@@ -133,6 +137,7 @@ public class VolumeRecord implements Parcelable {
     public void writeToParcel(Parcel parcel, int flags) {
         parcel.writeInt(type);
         parcel.writeString(fsUuid);
+        parcel.writeString(partGuid);
         parcel.writeString(nickname);
         parcel.writeInt(userFlags);
     }
diff --git a/core/java/android/text/TextUtils.java b/core/java/android/text/TextUtils.java
index d51aa79..d8f7158 100644
--- a/core/java/android/text/TextUtils.java
+++ b/core/java/android/text/TextUtils.java
@@ -465,6 +465,11 @@ public class TextUtils {
             return false;
     }
 
+    /** {@hide} */
+    public static String nullIfEmpty(@Nullable String str) {
+        return isEmpty(str) ? null : str;
+    }
+
     /**
      * Returns the length that the specified CharSequence would have if
      * spaces and control characters were trimmed from the start and end,
diff --git a/services/core/java/com/android/server/MountService.java b/services/core/java/com/android/server/MountService.java
index 34dceed..458150c 100644
--- a/services/core/java/com/android/server/MountService.java
+++ b/services/core/java/com/android/server/MountService.java
@@ -259,6 +259,7 @@ class MountService extends IMountService.Stub
     private static final String TAG_VOLUME = "volume";
     private static final String ATTR_TYPE = "type";
     private static final String ATTR_FS_UUID = "fsUuid";
+    private static final String ATTR_PART_GUID = "partGuid";
     private static final String ATTR_NICKNAME = "nickname";
     private static final String ATTR_USER_FLAGS = "userFlags";
 
@@ -689,7 +690,7 @@ 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, 0);
+                    VolumeInfo.TYPE_PRIVATE, null, null, 0);
             internal.state = VolumeInfo.STATE_MOUNTED;
             internal.path = Environment.getDataDirectory().getAbsolutePath();
             mVolumes.put(internal.id, internal);
@@ -900,10 +901,12 @@ class MountService extends IMountService.Stub
             case VoldResponseCode.VOLUME_CREATED: {
                 final String id = cooked[1];
                 final int type = Integer.parseInt(cooked[2]);
-                final String diskId = (cooked.length == 4) ? cooked[3] : null;
+                final String diskId = TextUtils.nullIfEmpty(cooked[3]);
+                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, mtpIndex);
+                final VolumeInfo vol = new VolumeInfo(id, type, disk, partGuid, mtpIndex);
                 mVolumes.put(id, vol);
                 onVolumeCreatedLocked(vol);
                 break;
@@ -1091,13 +1094,21 @@ class MountService extends IMountService.Stub
         // Remember that we saw this volume so we're ready to accept user
         // metadata, or so we can annoy them when a private volume is ejected
         if (vol.isMountedReadable() && !TextUtils.isEmpty(vol.fsUuid)) {
-            if (!mRecords.containsKey(vol.fsUuid)) {
-                final VolumeRecord rec = new VolumeRecord(vol.type, vol.fsUuid);
+            VolumeRecord rec = mRecords.get(vol.fsUuid);
+            if (rec == null) {
+                rec = new VolumeRecord(vol.type, vol.fsUuid);
+                rec.partGuid = vol.partGuid;
                 if (vol.type == VolumeInfo.TYPE_PRIVATE) {
                     rec.nickname = vol.disk.getDescription();
                 }
                 mRecords.put(rec.fsUuid, rec);
                 writeSettingsLocked();
+            } else {
+                // Handle upgrade case where we didn't store partition GUID
+                if (TextUtils.isEmpty(rec.partGuid)) {
+                    rec.partGuid = vol.partGuid;
+                    writeSettingsLocked();
+                }
             }
         }
 
@@ -1347,6 +1358,7 @@ class MountService extends IMountService.Stub
         final int type = readIntAttribute(in, ATTR_TYPE);
         final String fsUuid = readStringAttribute(in, ATTR_FS_UUID);
         final VolumeRecord meta = new VolumeRecord(type, fsUuid);
+        meta.partGuid = readStringAttribute(in, ATTR_PART_GUID);
         meta.nickname = readStringAttribute(in, ATTR_NICKNAME);
         meta.userFlags = readIntAttribute(in, ATTR_USER_FLAGS);
         return meta;
@@ -1356,6 +1368,7 @@ class MountService extends IMountService.Stub
         out.startTag(null, TAG_VOLUME);
         writeIntAttribute(out, ATTR_TYPE, rec.type);
         writeStringAttribute(out, ATTR_FS_UUID, rec.fsUuid);
+        writeStringAttribute(out, ATTR_PART_GUID, rec.partGuid);
         writeStringAttribute(out, ATTR_NICKNAME, rec.nickname);
         writeIntAttribute(out, ATTR_USER_FLAGS, rec.userFlags);
         out.endTag(null, TAG_VOLUME);
@@ -1573,9 +1586,11 @@ class MountService extends IMountService.Stub
 
         Preconditions.checkNotNull(fsUuid);
         synchronized (mLock) {
-            mRecords.remove(fsUuid);
-
-            // TODO: tell vold to forget keys
+            final VolumeRecord rec = mRecords.remove(fsUuid);
+            if (rec != null && !TextUtils.isEmpty(rec.partGuid)) {
+                forgetPartition(rec.partGuid);
+            }
+            mCallbacks.notifyVolumeForgotten(fsUuid);
 
             // If this had been primary storage, revert back to internal and
             // reset vold so we bind into new volume into place.
@@ -1584,7 +1599,6 @@ class MountService extends IMountService.Stub
                 resetIfReadyAndConnected();
             }
 
-            mCallbacks.notifyVolumeForgotten(fsUuid);
             writeSettingsLocked();
         }
     }
@@ -1597,6 +1611,10 @@ class MountService extends IMountService.Stub
         synchronized (mLock) {
             for (int i = 0; i < mRecords.size(); i++) {
                 final String fsUuid = mRecords.keyAt(i);
+                final VolumeRecord rec = mRecords.valueAt(i);
+                if (!TextUtils.isEmpty(rec.partGuid)) {
+                    forgetPartition(rec.partGuid);
+                }
                 mCallbacks.notifyVolumeForgotten(fsUuid);
             }
             mRecords.clear();
@@ -1610,6 +1628,14 @@ class MountService extends IMountService.Stub
         }
     }
 
+    private void forgetPartition(String partGuid) {
+        try {
+            mConnector.execute("volume", "forget_partition", partGuid);
+        } catch (NativeDaemonConnectorException e) {
+            Slog.w(TAG, "Failed to forget key for " + partGuid + ": " + e);
+        }
+    }
+
     @Override
     public void setDebugFlags(int flags, int mask) {
         enforcePermission(android.Manifest.permission.MOUNT_UNMOUNT_FILESYSTEMS);