1 /* pivot_root.c - edit system mount tree 2 * 3 * Copyright 2012 Rob Landley <rob (at) landley.net> 4 5 USE_PIVOT_ROOT(NEWTOY(pivot_root, "<2>2", TOYFLAG_SBIN)) 6 7 config 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 25 #include <sys/syscall.h> 26 #include <unistd.h> 27 28 void pivot_root_main(void) 29 { 30 if (syscall(__NR_pivot_root, toys.optargs[0], toys.optargs[1])) 31 perror_exit("'%s' -> '%s'", toys.optargs[0], toys.optargs[1]); 32 } 33
