gistfile1.txt

#include <stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/mount.h>
#include <stdlib.h>

int main(int argc, char **argv) {
  mkdir("/mnt/aufs", 0755);
  mkdir("/tmp/br1", 0755);
  mkdir("/tmp/br2", 0755);

  for (int i=0; 1; i++) {
    if (i % 100 == 0) {
      printf("iteration %d\n", i);
    }

    int error = mount("none", "/mnt/aufs", "aufs", 0, "br=/tmp/br1:/tmp/br2");
    if (error) {
      printf("mount error on iteration %d: %d\n", i, error);
      exit(error);
    }
    error = umount("/mnt/aufs");
    if (error) {
      printf("umount error on iteration %d: %d\n", i, error);
      exit(error);
    }
  }
}

compile with gcc -std=c99