Fail to create new file with GridFile

The current code GridFile.java fails to create any new file with the file path containing parent components.
For example, the following code will fail to create the new file:

...
GridFileSystem fs= new GridFileSystem(data, metadata);
File gridDir = fs.getFile("/test");
gridDir.mkdirs();

//The following fails to create the file
File gridFile = fs.getFile("/test/myfile.txt");
gridFile.createNewFile(); //this line always returns false.
....

The root cause of the above failure is that the method of "checkParentDirs(String path, boolean create_if_absent)"
does not handle the parent dir already exists case correctly.