Add ostree-switch-root here

Merge the code from ostree-init; now that we're back to targeting an
initramfs (dracut), we don't need to statically link the binary, so
there's no strong reason to have a separate module.
This commit is contained in:
Colin Walters 2012-02-05 16:02:44 -05:00
parent 4de5a36b24
commit a904c9693b
3 changed files with 207 additions and 0 deletions

22
Makefile-switchroot.am Normal file
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@ -0,0 +1,22 @@
# Copyright (C) 2011 Colin Walters <walters@verbum.org>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2 of the License, or (at your option) any later version.
#
# This library 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
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the
# Free Software Foundation, Inc., 59 Temple Place - Suite 330,
# Boston, MA 02111-1307, USA.
sbin_PROGRAMS += ostree-switch-root
ostree_switch_root_SOURCES = src/switchroot/ostree-switch-root.c
ostree_switch_root_CFLAGS = $(AM_CFLAGS)

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@ -25,6 +25,7 @@ MANPAGES =
CLEANFILES =
EXTRA_DIST =
bin_PROGRAMS =
sbin_PROGRAMS =
bin_SCRIPTS =
libexec_PROGRAMS =
noinst_LTLIBRARIES =
@ -36,6 +37,7 @@ include Makefile-daemon.am
include Makefile-otutil.am
include Makefile-libostree.am
include Makefile-ostree.am
include Makefile-switchroot.am
include Makefile-ostbuild.am
include Makefile-triggers.am

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@ -0,0 +1,183 @@
/* -*- c-file-style: "gnu" -*-
* Switch to new root directory and start init.
* Copyright 2011,2012 Colin Walters <walters@verbum.org>
*
* 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/>.
*
*/
#define _GNU_SOURCE
#include <sys/mount.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <fcntl.h>
#include <assert.h>
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include <dirent.h>
static int
perrorv (const char *format, ...) __attribute__ ((format (printf, 1, 2)));
static int
perrorv (const char *format, ...)
{
va_list args;
char buf[PATH_MAX];
char *p;
p = strerror_r (errno, buf, sizeof (buf));
va_start (args, format);
vfprintf (stderr, format, args);
fprintf (stderr, ": %s\n", p);
fflush (stderr);
va_end (args);
sleep (3);
return 0;
}
int
main(int argc, char *argv[])
{
const char *initramfs_move_mounts[] = { "/dev", "/proc", "/sys", "/run", NULL };
const char *toproot_bind_mounts[] = { "/home", "/root", "/tmp", NULL };
const char *ostree_bind_mounts[] = { "/var", NULL };
const char *readonly_bind_mounts[] = { "/bin", "/etc", "/lib", "/sbin", "/usr",
NULL };
const char *ostree_root = NULL;
const char *ostree_subinit = NULL;
char srcpath[PATH_MAX];
char destpath[PATH_MAX];
struct stat stbuf;
char **init_argv = NULL;
int i;
int before_init_argc = 0;
if (argc < 3)
{
fprintf (stderr, "usage: ostree-switch-root NEWROOT INIT [ARGS...]\n");
exit (1);
}
before_init_argc++;
ostree_root = argv[1];
before_init_argc++;
ostree_subinit = argv[2];
before_init_argc++;
snprintf (destpath, sizeof(destpath), "/ostree/%s", ostree_root);
if (stat (destpath, &stbuf) < 0)
{
perrorv ("Invalid ostree root '%s'", destpath);
exit (1);
}
snprintf (destpath, sizeof(destpath), "/ostree/%s/var", ostree_root);
if (mount ("/ostree/var", destpath, NULL, MS_BIND, NULL) < 0)
{
perrorv ("Failed to bind mount / to '%s'", destpath);
exit (1);
}
snprintf (destpath, sizeof(destpath), "/ostree/%s/sysroot", ostree_root);
if (mount ("/", destpath, NULL, MS_BIND, NULL) < 0)
{
perrorv ("Failed to bind mount / to '%s'", destpath);
exit (1);
}
for (i = 0; initramfs_move_mounts[i] != NULL; i++)
{
const char *path = initramfs_move_mounts[i];
snprintf (srcpath, sizeof(srcpath), path);
snprintf (destpath, sizeof(destpath), "/ostree/%s%s", ostree_root, path);
if (mount (srcpath, destpath, NULL, MS_MOVE, NULL) < 0)
{
perrorv ("failed to move mount of %s to %s", srcpath, destpath);
exit (1);
}
}
for (i = 0; toproot_bind_mounts[i] != NULL; i++)
{
snprintf (destpath, sizeof(destpath), "/ostree/%s%s", ostree_root, toproot_bind_mounts[i]);
if (mount (toproot_bind_mounts[i], destpath, NULL, MS_BIND & ~MS_RDONLY, NULL) < 0)
{
perrorv ("failed to bind mount (class:toproot) %s to %s", toproot_bind_mounts[i], destpath);
exit (1);
}
}
for (i = 0; ostree_bind_mounts[i] != NULL; i++)
{
snprintf (srcpath, sizeof(srcpath), "/ostree/%s", ostree_bind_mounts[i]);
snprintf (destpath, sizeof(destpath), "/ostree/%s%s", ostree_root, ostree_bind_mounts[i]);
if (mount (srcpath, destpath, NULL, MS_MGC_VAL|MS_BIND, NULL) < 0)
{
perrorv ("failed to bind mount (class:bind) %s to %s", srcpath, destpath);
exit (1);
}
}
for (i = 0; readonly_bind_mounts[i] != NULL; i++)
{
snprintf (destpath, sizeof(destpath), "/ostree/%s%s", ostree_root, readonly_bind_mounts[i]);
if (mount (destpath, destpath, NULL, MS_BIND, NULL) < 0)
{
perrorv ("failed to bind mount (class:readonly) %s", destpath);
exit (1);
}
if (mount (destpath, destpath, NULL, MS_BIND | MS_REMOUNT | MS_RDONLY, NULL) < 0)
{
perrorv ("failed to bind mount (class:readonly) %s", destpath);
exit (1);
}
}
snprintf (destpath, sizeof(destpath), "/ostree/%s", ostree_root);
if (chroot (destpath) < 0)
{
perrorv ("failed to change root to '%s'", destpath);
exit (1);
}
if (chdir ("/") < 0)
{
perrorv ("failed to chdir to subroot");
exit (1);
}
init_argv = malloc (sizeof (char*)*((argc-before_init_argc)+2));
init_argv[0] = (char*)ostree_subinit;
for (i = 0; i < argc-before_init_argc; i++)
init_argv[i+1] = argv[i+before_init_argc];
init_argv[i+1] = NULL;
fprintf (stderr, "ostree-init: Running real init %s (argc=%d)\n", init_argv[0], argc-before_init_argc);
fflush (stderr);
execv (init_argv[0], init_argv);
perrorv ("Failed to exec init '%s'", init_argv[0]);
exit (1);
}