switch_root: new command
Copied from Dracut project: git://dracut.git.sourceforge.net/gitroot/dracut switch_root history in dracut.git repository: $ git shortlog switch_root.c Harald Hoyer (5): replace switch_root shell script with binary add \n to switch_root use switch_root code from http://pjones.fedorapeople.org/mkstart/usr/lib/mkstart/switchroot.c mount move instead of umount and fix the search for fallback inits setsid() and set controlling terminal for real /sbin/init Victor Lowther (2): Simplify switch_root.c a bit Remove all files on the initramfs before switching root Signed-off-by: Peter Jones <pjones@redhat.com> Signed-off-by: Karel Zak <kzak@redhat.com>
This commit is contained in:
parent
e9799b6d29
commit
711ea7307d
2
AUTHORS
2
AUTHORS
|
@ -29,6 +29,8 @@ AUTHORS (merged projects & commands):
|
||||||
setarch: Elliot Lee <sopwith@redhat.com>
|
setarch: Elliot Lee <sopwith@redhat.com>
|
||||||
Jindrich Novy <jnovy@redhat.com>
|
Jindrich Novy <jnovy@redhat.com>
|
||||||
simpleinit: Richard Gooch <rgooch@atnf.csiro.au>
|
simpleinit: Richard Gooch <rgooch@atnf.csiro.au>
|
||||||
|
switch_root: Peter Jones <pjones@redhat.com>
|
||||||
|
Jeremy Katz <katzj@redhat.com>
|
||||||
|
|
||||||
|
|
||||||
CONTRIBUTORS:
|
CONTRIBUTORS:
|
||||||
|
|
|
@ -180,6 +180,7 @@ sys-utils/renice.c
|
||||||
sys-utils/rtcwake.c
|
sys-utils/rtcwake.c
|
||||||
sys-utils/setarch.c
|
sys-utils/setarch.c
|
||||||
sys-utils/setsid.c
|
sys-utils/setsid.c
|
||||||
|
sys-utils/switch_root.c
|
||||||
sys-utils/tunelp.c
|
sys-utils/tunelp.c
|
||||||
text-utils/col.c
|
text-utils/col.c
|
||||||
text-utils/colcrt.c
|
text-utils/colcrt.c
|
||||||
|
|
|
@ -36,6 +36,7 @@ sparc32.8
|
||||||
sparc32bash.8
|
sparc32bash.8
|
||||||
sparc64.8
|
sparc64.8
|
||||||
sparc.8
|
sparc.8
|
||||||
|
switch_root
|
||||||
tunelp
|
tunelp
|
||||||
vidmode.8
|
vidmode.8
|
||||||
x86_64.8
|
x86_64.8
|
||||||
|
|
|
@ -1,7 +1,7 @@
|
||||||
include $(top_srcdir)/config/include-Makefile.am
|
include $(top_srcdir)/config/include-Makefile.am
|
||||||
|
|
||||||
bin_PROGRAMS =
|
bin_PROGRAMS =
|
||||||
sbin_PROGRAMS =
|
sbin_PROGRAMS = switch_root
|
||||||
usrbinexec_PROGRAMS = flock ipcrm ipcs ipcmk renice setsid
|
usrbinexec_PROGRAMS = flock ipcrm ipcs ipcmk renice setsid
|
||||||
usrsbinexec_PROGRAMS = readprofile
|
usrsbinexec_PROGRAMS = readprofile
|
||||||
|
|
||||||
|
|
|
@ -0,0 +1,198 @@
|
||||||
|
/*
|
||||||
|
* switchroot.c - switch to new root directory and start init.
|
||||||
|
*
|
||||||
|
* Copyright 2002-2008 Red Hat, Inc. All rights reserved.
|
||||||
|
*
|
||||||
|
* This program is free software; you can redistribute it and/or modify
|
||||||
|
* it under the terms of the GNU General Public License as published by
|
||||||
|
* the Free Software Foundation; either version 2 of the License, or
|
||||||
|
* (at your option) any later version.
|
||||||
|
*
|
||||||
|
* This program is distributed in the hope that it will be useful,
|
||||||
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||||
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||||
|
* GNU General Public License for more details.
|
||||||
|
*
|
||||||
|
* You should have received a copy of the GNU General Public License
|
||||||
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
||||||
|
*
|
||||||
|
* Authors:
|
||||||
|
* Peter Jones <pjones@redhat.com>
|
||||||
|
* Jeremy Katz <katzj@redhat.com>
|
||||||
|
*/
|
||||||
|
|
||||||
|
#define _GNU_SOURCE 1
|
||||||
|
|
||||||
|
#include <sys/mount.h>
|
||||||
|
#include <sys/types.h>
|
||||||
|
#include <sys/stat.h>
|
||||||
|
#include <sys/param.h>
|
||||||
|
#include <fcntl.h>
|
||||||
|
#include <stdio.h>
|
||||||
|
#include <stdlib.h>
|
||||||
|
#include <unistd.h>
|
||||||
|
#include <string.h>
|
||||||
|
#include <errno.h>
|
||||||
|
#include <ctype.h>
|
||||||
|
#include <dirent.h>
|
||||||
|
|
||||||
|
#ifndef MS_MOVE
|
||||||
|
#define MS_MOVE 8192
|
||||||
|
#endif
|
||||||
|
|
||||||
|
#ifndef MNT_DETACH
|
||||||
|
#define MNT_DETACH 0x2
|
||||||
|
#endif
|
||||||
|
|
||||||
|
enum {
|
||||||
|
ok,
|
||||||
|
err_no_directory,
|
||||||
|
err_usage,
|
||||||
|
};
|
||||||
|
|
||||||
|
/* remove all files/directories below dirName -- don't cross mountpoints */
|
||||||
|
static int
|
||||||
|
recursiveRemove(char * dirName)
|
||||||
|
{
|
||||||
|
struct stat sb,rb;
|
||||||
|
DIR * dir;
|
||||||
|
struct dirent * d;
|
||||||
|
char * strBuf = alloca(strlen(dirName) + 1024);
|
||||||
|
|
||||||
|
if (!(dir = opendir(dirName))) {
|
||||||
|
printf("error opening %s: %m\n", dirName);
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
if (fstat(dirfd(dir),&rb)) {
|
||||||
|
printf("unable to stat %s: %m\n", dirName);
|
||||||
|
closedir(dir);
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
errno = 0;
|
||||||
|
while ((d = readdir(dir))) {
|
||||||
|
errno = 0;
|
||||||
|
|
||||||
|
if (!strcmp(d->d_name, ".") || !strcmp(d->d_name, "..")) {
|
||||||
|
errno = 0;
|
||||||
|
continue;
|
||||||
|
}
|
||||||
|
|
||||||
|
strcpy(strBuf, dirName);
|
||||||
|
strcat(strBuf, "/");
|
||||||
|
strcat(strBuf, d->d_name);
|
||||||
|
|
||||||
|
if (lstat(strBuf, &sb)) {
|
||||||
|
printf("failed to stat %s: %m\n", strBuf);
|
||||||
|
errno = 0;
|
||||||
|
continue;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* only descend into subdirectories if device is same as dir */
|
||||||
|
if (S_ISDIR(sb.st_mode)) {
|
||||||
|
if (sb.st_dev == rb.st_dev) {
|
||||||
|
recursiveRemove(strBuf);
|
||||||
|
if (rmdir(strBuf))
|
||||||
|
printf("failed to rmdir %s: %m\n", strBuf);
|
||||||
|
}
|
||||||
|
errno = 0;
|
||||||
|
continue;
|
||||||
|
}
|
||||||
|
if (unlink(strBuf)) {
|
||||||
|
printf("failed to remove %s: %m\n", strBuf);
|
||||||
|
errno = 0;
|
||||||
|
continue;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
if (errno) {
|
||||||
|
closedir(dir);
|
||||||
|
printf("error reading from %s: %m\n", dirName);
|
||||||
|
return 1;
|
||||||
|
}
|
||||||
|
|
||||||
|
closedir(dir);
|
||||||
|
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
static int switchroot(const char *newroot)
|
||||||
|
{
|
||||||
|
/* Don't try to unmount the old "/", there's no way to do it. */
|
||||||
|
const char *umounts[] = { "/dev", "/proc", "/sys", NULL };
|
||||||
|
int errnum;
|
||||||
|
int i;
|
||||||
|
|
||||||
|
for (i = 0; umounts[i] != NULL; i++) {
|
||||||
|
char newmount[PATH_MAX];
|
||||||
|
strcpy(newmount, newroot);
|
||||||
|
strcat(newmount, umounts[i]);
|
||||||
|
if (mount(umounts[i], newmount, NULL, MS_MOVE, NULL) < 0) {
|
||||||
|
fprintf(stderr, "Error mount moving old %s %s %m\n",
|
||||||
|
umounts[i], newmount);
|
||||||
|
fprintf(stderr, "Forcing unmount of %s\n", umounts[i]);
|
||||||
|
umount2(umounts[i], MNT_FORCE);
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
if (chdir(newroot) < 0) {
|
||||||
|
errnum=errno;
|
||||||
|
fprintf(stderr, "switchroot: chdir failed: %m\n");
|
||||||
|
errno=errnum;
|
||||||
|
return -1;
|
||||||
|
}
|
||||||
|
recursiveRemove("/");
|
||||||
|
if (mount(newroot, "/", NULL, MS_MOVE, NULL) < 0) {
|
||||||
|
errnum = errno;
|
||||||
|
fprintf(stderr, "switchroot: mount failed: %m\n");
|
||||||
|
errno = errnum;
|
||||||
|
return -1;
|
||||||
|
}
|
||||||
|
|
||||||
|
if (chroot(".")) {
|
||||||
|
errnum = errno;
|
||||||
|
fprintf(stderr, "switchroot: chroot failed: %m\n");
|
||||||
|
errno = errnum;
|
||||||
|
return -2;
|
||||||
|
}
|
||||||
|
return 1;
|
||||||
|
}
|
||||||
|
|
||||||
|
static void usage(FILE *output)
|
||||||
|
{
|
||||||
|
fprintf(output, "usage: switchroot <newrootdir> <init> <args to init>\n");
|
||||||
|
if (output == stderr)
|
||||||
|
exit(err_usage);
|
||||||
|
exit(ok);
|
||||||
|
}
|
||||||
|
|
||||||
|
int main(int argc, char *argv[])
|
||||||
|
{
|
||||||
|
char *newroot = argv[1];
|
||||||
|
char *init = argv[2];
|
||||||
|
char **initargs = &argv[2];
|
||||||
|
|
||||||
|
if (newroot == NULL || newroot[0] == '\0' ||
|
||||||
|
init == NULL || init[0] == '\0' ) {
|
||||||
|
usage(stderr);
|
||||||
|
}
|
||||||
|
|
||||||
|
if (switchroot(newroot) < 0) {
|
||||||
|
fprintf(stderr, "switchroot has failed. Sorry.\n");
|
||||||
|
return 1;
|
||||||
|
}
|
||||||
|
if (access(initargs[0], X_OK))
|
||||||
|
fprintf(stderr, "WARNING: can't access %s\n", initargs[0]);
|
||||||
|
|
||||||
|
/* get session leader */
|
||||||
|
setsid();
|
||||||
|
/* set controlling terminal */
|
||||||
|
ioctl (0, TIOCSCTTY, 1);
|
||||||
|
|
||||||
|
execv(initargs[0], initargs);
|
||||||
|
}
|
||||||
|
|
||||||
|
/*
|
||||||
|
* vim:noet:ts=8:sw=8:sts=8
|
||||||
|
*/
|
Loading…
Reference in New Issue