Enter null namespace for redoxfs

src/mount/redox/mod.rs

 extern crate spin;
 
+use syscall;
 use syscall::{Packet, Scheme};
 use std::fs::File;
 use std::io::{self, Read, Write};
@@ -19,6 +20,8 @@ pub fn mount<D: Disk, P: AsRef<Path>, F: FnMut()>(filesystem: FileSystem<D>, mou
 
     callback();
 
+    syscall::setrens(0, 0).expect("redoxfs: failed to enter null namespace");
+
     let scheme = FileScheme::new(format!("{}", mountpoint.display()), filesystem);
     loop {
         let mut packet = Packet::default();