Mercurial > hg > toybox
diff toys/other/pivot_root.c @ 929:9e00446064fa
Add pivot_root.
author | Rob Landley <rob@landley.net> |
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date | Tue, 18 Jun 2013 18:13:06 -0500 |
parents | |
children | da72fa267b7b |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/toys/other/pivot_root.c Tue Jun 18 18:13:06 2013 -0500 @@ -0,0 +1,31 @@ +/* pivot_root.c - edit system mount tree + * + * Copyright 2012 Rob Landley <rob@landley.net> + +USE_PIVOT_ROOT(NEWTOY(pivot_root, "<2>2", TOYFLAG_USR|TOYFLAG_BIN)) + +config PIVOT_ROOT + bool "pivot_root" + default y + help + usage: pivot_root OLD NEW + + Swap OLD and NEW filesystems (as if by simultaneous mount --move), and + move all processes with chdir or chroot under OLD into NEW (including + kernel threads) so OLD may be unmounted. + + The directory NEW must exist under OLD. This doesn't work on initramfs, + which can't be moved (about the same way PID 1 can't be killed; see + switch_root instead). +*/ + +#define FOR_pivot_root +#include "toys.h" + +#include <linux/unistd.h> + +void pivot_root_main(void) +{ + if (syscall(__NR_pivot_root, toys.optargs[0], toys.optargs[1])) + perror_exit("'%s' -> '%s'", toys.optargs[0], toys.optargs[1]); +}