mounting nfs, cifs, etc on android 4.3 On my new Nexus 7 running android 4.3, /proc/filesystems claims to have support for cifs, nfs, and nfs4 built into the kernel.

Unfortunately, also on android 4.3, google has arrange things so that everyone has their own mountpoint namespace, so while I can, in fact, mount an nfs4 directory from my fedora 19 server in a rooted shell, I can't see that mountpoint anywhere outside that shell (which puts a crimp in the usefulness of the mount).

Is there any way to make a newly created mountpoint visible to all apps? (Other than modifying the kernel or something like that).

This android doc page has some cryptic info at the bottom about the namespace issue:

http://source.android.com/devices/tech/storage/index.html
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.