Fix task memory leaks; better path validation.

We've been allocating task objects without freeing them, oops.  We
don't really need full classes for these tasks, so move them to
blocking methods, and invoke them from a detached thread.

Remove FIDTRIM support, which isn't meaningful on UFS-based flash
devices.  Modern devices require FBE/FDE which gives us better
protection against trimmed data lingering around.

Rename "Trim" to more generic "IdleMaint", since it'll soon extend
to include custom F2FS optimization logic.

Check for shady ".." when validating paths.

Test: cts-tradefed run commandAndExit cts-dev -m CtsOsTestCases -t android.os.storage.cts.StorageManagerTest
Test: cts-tradefed run commandAndExit cts-dev --abi armeabi-v7a -m CtsAppSecurityHostTestCases -t android.appsecurity.cts.AdoptableHostTest
Bug: 67041047
Change-Id: I4fb194c5d5ef13f413c02acedfbaaf79c567582b
diff --git a/IdleMaint.h b/IdleMaint.h
new file mode 100644
index 0000000..38dadfb
--- /dev/null
+++ b/IdleMaint.h
@@ -0,0 +1,30 @@
+/*
+ * Copyright (C) 2015 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.
+ */
+
+#ifndef ANDROID_VOLD_IDLE_MAINT_H
+#define ANDROID_VOLD_IDLE_MAINT_H
+
+#include "android/os/IVoldTaskListener.h"
+
+namespace android {
+namespace vold {
+
+void Trim(const android::sp<android::os::IVoldTaskListener>& listener);
+
+}  // namespace vold
+}  // namespace android
+
+#endif