mounting nfs, cifs, etc on android 4.3
http://forum.xda-developers.com/showthread.php?t=2107224

Android >= 4.2 breaks Dalvik-apps that mount file systems to be shared with other apps. The linked page has an explanation of the issue, and patches that can be applied to the kernel source (or the Dalvik source, if you prefer) to make a custom ROM that lets you do this.