busybox/umount.c
Erik Andersen b7cc49d992 * Added -o loop option for mount, and support in umount for loop
devices. Support is toggled by MOUNT_LOOP feature -- Ben Collins
    <bcollins@debian.org>

 -Erik
2000-01-13 06:38:14 +00:00

198 lines
4.2 KiB
C

/*
* Mini umount implementation for busybox
*
*
* Copyright (C) 1999 by Lineo, inc.
* Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include "internal.h"
#include <stdio.h>
#include <sys/mount.h>
#include <mntent.h>
#include <fstab.h>
#include <errno.h>
#if defined BB_FEATURE_MOUNT_LOOP
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/loop.h>
static int del_loop(const char *device);
#endif
static const char umount_usage[] =
"Usage: umount [flags] filesystem|directory\n\n"
"Flags:\n"
"\t-a:\tUnmount all file systems"
#ifdef BB_MTAB
" in /etc/mtab\n\t-n:\tDon't erase /etc/mtab entries\n"
#else
"\n"
#endif
;
static int useMtab = TRUE;
static int umountAll = FALSE;
extern const char mtab_file[]; /* Defined in utility.c */
static int
do_umount(const char* name, int useMtab)
{
int status;
#if defined BB_FEATURE_MOUNT_LOOP
/* check to see if this is a loop device */
struct stat fst;
char dev[20];
const char *oldname = NULL;
int i;
if (stat(name, &fst)) {
fprintf(stderr, "umount: %s: %s\n", name, strerror(errno));
exit(1);
}
for (i = 0 ; i <= 7 ; i++) {
struct stat lst;
sprintf(dev, "/dev/loop%d", i);
if (stat(dev, &lst))
continue;
if (lst.st_dev == fst.st_dev) {
oldname = name;
name = dev;
break;
}
}
#endif
status = umount(name);
#if defined BB_FEATURE_MOUNT_LOOP
if (!strncmp("/dev/loop", name, 9)) { /* this was a loop device, delete it */
del_loop(name);
if (oldname != NULL)
name = oldname;
}
#endif
#if defined BB_MTAB
if ( status == 0 ) {
if ( useMtab==TRUE )
erase_mtab(name);
return 0;
}
else
#endif
return(status);
}
static int
umount_all(int useMtab)
{
int status;
struct mntent *m;
FILE *mountTable;
if ((mountTable = setmntent (mtab_file, "r"))) {
while ((m = getmntent (mountTable)) != 0) {
char *blockDevice = m->mnt_fsname;
#if ! defined BB_MTAB
if (strcmp (blockDevice, "/dev/root") == 0) {
struct fstab* fstabItem;
fstabItem = getfsfile ("/");
if (fstabItem != NULL) {
blockDevice = fstabItem->fs_spec;
}
}
#endif
/* Don't umount /proc when doing umount -a */
if (strcmp (blockDevice, "proc") == 0)
continue;
status=do_umount (m->mnt_dir, useMtab);
if (status!=0) {
/* Don't bother retrying the umount on busy devices */
if (errno==EBUSY) {
perror(m->mnt_dir);
continue;
}
status=do_umount (blockDevice, useMtab);
if (status!=0) {
printf ("Couldn't umount %s on %s (type %s): %s\n",
blockDevice, m->mnt_dir, m->mnt_type, strerror(errno));
}
}
}
endmntent (mountTable);
}
return( TRUE);
}
extern int
umount_main(int argc, char** argv)
{
if (argc < 2) {
usage( umount_usage);
}
/* Parse any options */
while (--argc > 0 && **(++argv) == '-') {
while (*++(*argv)) switch (**argv) {
case 'a':
umountAll = TRUE;
break;
#ifdef BB_MTAB
case 'n':
useMtab = FALSE;
break;
#endif
default:
usage( umount_usage);
}
}
if(umountAll==TRUE) {
exit(umount_all(useMtab));
}
if ( do_umount(*argv,useMtab) == 0 )
exit (TRUE);
else {
perror("umount");
exit(FALSE);
}
}
#if defined BB_FEATURE_MOUNT_LOOP
static int del_loop(const char *device)
{
int fd;
if ((fd = open(device, O_RDONLY)) < 0) {
perror(device);
exit(1);
}
if (ioctl(fd, LOOP_CLR_FD, 0) < 0) {
perror("ioctl: LOOP_CLR_FD");
exit(1);
}
close(fd);
return(0);
}
#endif