LXR toybox/toys/other/pivot

   1/* pivot_root.c - edit system mount tree
   2 *
   3 * Copyright 2012 Rob Landley <rob@landley.net>
   4
   5USE_PIVOT_ROOT(NEWTOY(pivot_root, "<2>2", TOYFLAG_SBIN))
   6
   7config PIVOT_ROOT
   8  bool "pivot_root"
   9  default y
  10  help
  11    usage: pivot_root OLD NEW
  12
  13    Swap OLD and NEW filesystems (as if by simultaneous mount --move), and
  14    move all processes with chdir or chroot under OLD into NEW (including
  15    kernel threads) so OLD may be unmounted.
  16
  17    The directory NEW must exist under OLD. This doesn't work on initramfs,
  18    which can't be moved (about the same way PID 1 can't be killed; see
  19    switch_root instead).
  20*/
  21
  22#define FOR_pivot_root
  23#include "toys.h"
  24
  25void pivot_root_main(void)
  26{
  27  if (syscall(__NR_pivot_root, toys.optargs[0], toys.optargs[1]))
  28    perror_exit("'%s' -> '%s'", toys.optargs[0], toys.optargs[1]);
  29}
  30