ostree/src/switchroot/ostree-remount.c

88 lines
2.3 KiB
C

/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
*
* 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.
*
* Author: Colin Walters <walters@verbum.org>
*/
#include "config.h"
#include <string.h>
#include <stdio.h>
#include <stdarg.h>
#include <stdint.h>
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/statvfs.h>
#include <fcntl.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/stat.h>
#include <errno.h>
#include "ostree-mount-util.h"
int
main(int argc, char *argv[])
{
const char *remounts[] = { "/sysroot", "/etc", "/home", "/root", "/tmp", "/var", NULL };
struct stat stbuf;
int i;
struct statvfs stvfsbuf;
if (statvfs ("/", &stvfsbuf) == -1)
{
perror ("statvfs(/): ");
exit (1);
}
if (stvfsbuf.f_flag & ST_RDONLY)
{
/* If / isn't writable, don't do any remounts; we don't want
* to clear the readonly flag in that case.
*/
exit (0);
}
for (i = 0; remounts[i] != NULL; i++)
{
const char *target = remounts[i];
if (lstat (target, &stbuf) < 0)
continue;
/* Silently ignore symbolic links; we expect these to point to
* /sysroot, and thus there isn't a bind mount there.
*/
if (S_ISLNK (stbuf.st_mode))
continue;
if (mount (target, target, NULL, MS_REMOUNT | MS_SILENT, NULL) < 0)
{
/* Also ignore ENINVAL - if the target isn't a mountpoint
* already, then assume things are OK.
*/
if (errno != EINVAL)
{
perrorv ("failed to remount %s", target);
exit (1);
}
}
}
exit (0);
}