External library with modifications.  fat32-lib.
Signed-off-by: Dan Galpin <dgalpin@google.com>

Change-Id: Ie59bda0c04d629c4b2723f77478957105761e5cf
diff --git a/src/main/java/de/waldheinz/fs/FileSystem.java b/src/main/java/de/waldheinz/fs/FileSystem.java
new file mode 100644
index 0000000..f84baae
--- /dev/null
+++ b/src/main/java/de/waldheinz/fs/FileSystem.java
@@ -0,0 +1,95 @@
+/*
+ * Copyright (C) 2003-2009 JNode.org
+ *               2009,2010 Matthias Treydte <mt@waldheinz.de>
+ *
+ * This library is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this library; If not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+ 
+package de.waldheinz.fs;
+
+import java.io.IOException;
+
+/**
+ * The interface common to all file system implementations.
+ *
+ * @author Ewout Prangsma &lt;epr at jnode.org&gt;
+ * @author Matthias Treydte &lt;waldheinz at gmail.com&gt;
+ */
+public interface FileSystem {
+    
+    /**
+     * Gets the root entry of this filesystem. This is usually a directory, but
+     * this is not required.
+     * 
+     * @return the file system's root entry
+     * @throws IOException on read error
+     */
+    public FsDirectory getRoot() throws IOException;
+
+    /**
+     * Returns if this {@code FileSystem} is in read-only mode.
+     *
+     * @return if this {@code FileSystem} is read-only
+     */
+    public boolean isReadOnly();
+
+    /**
+     * Close this file system. After a close, all invocations of methods of
+     * this file system or objects created by this file system will throw an
+     * {@link IllegalStateException}.
+     * 
+     * @throws IOException on error closing the file system
+     */
+    public void close() throws IOException;
+    
+    /**
+     * Returns {@code true} if this file system is closed. If the file system
+     * is closed, no more operations may be performed on it.
+     * 
+     * @return if this file system is closed
+     */
+    public boolean isClosed();
+
+    /**
+     * The total size of this file system.
+     *
+     * @return if -1 this feature is unsupported
+     * @throws IOException if an I/O error occurs
+     */
+    public long getTotalSpace() throws IOException;
+
+    /**
+     * The free space of this file system.
+     *
+     * @return if -1 this feature is unsupported
+     * @throws IOException if an I/O error occurs
+     */
+    public long getFreeSpace() throws IOException;
+
+    /**
+     * The usable space of this file system.
+     *
+     * @return if -1 this feature is unsupported
+     * @throws IOException if an I/O error occurs
+     */
+    public long getUsableSpace() throws IOException;
+
+    /**
+     * Flushes any modified file system structures to the underlying storage.
+     *
+     * @throws IOException
+     */
+    public void flush() throws IOException;
+}