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/* vi: set sw=4 ts=4: */
/*
* Mini umount implementation for busybox
*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
* Copyright (C) 2005 by Rob Landley <rob@landley.net>
*
* This program is licensed under the GNU General Public license (GPL)
* version 2 or later, see http://www.fsf.org/licensing/licenses/gpl.html
* or the file "LICENSE" in the busybox source tarball for the full text.
*
*/
#include <limits.h>
#include <stdio.h>
#include <mntent.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <sys/mount.h>
#include <getopt.h>
#include "busybox.h"
#define OPTION_STRING "flaDnrv"
#define OPT_FORCE 1
#define OPT_LAZY 2
#define OPT_ALL 4
#define OPT_DONTFREELOOP 8
#define OPT_NO_MTAB 16
#define OPT_REMOUNT 32
/* -v is ignored */
extern int umount_main(int argc, char **argv)
{
int doForce;
char path[2*PATH_MAX];
struct mntent me;
FILE *fp;
int status=EXIT_SUCCESS;
unsigned long opt;
struct mtab_list {
char *dir;
char *device;
struct mtab_list *next;
} *mtl, *m;
/* Parse any options */
opt = bb_getopt_ulflags (argc, argv, OPTION_STRING);
argc -= optind;
argv += optind;
doForce = MAX((opt & OPT_FORCE), (opt & OPT_LAZY));
/* Get a list of mount points from mtab. We read them all in now mostly
* for umount -a (so we don't have to worry about the list changing while
* we iterate over it, or about getting stuck in a loop on the same failing
* entry. Notice that this also naturally reverses the list so that -a
* umounts the most recent entries first. */
m=mtl=0;
if(!(fp = setmntent(bb_path_mtab_file, "r")))
bb_error_msg_and_die("Cannot open %s", bb_path_mtab_file);
while (getmntent_r(fp,&me,path,sizeof(path))) {
m=xmalloc(sizeof(struct mtab_list));
m->next=mtl;
m->device=bb_xstrdup(me.mnt_fsname);
m->dir=bb_xstrdup(me.mnt_dir);
mtl=m;
}
endmntent(fp);
/* If we're umounting all, then m points to the start of the list and
* the argument list should be empty (which will match all). */
if(!(opt & OPT_ALL)) {
m=0;
if(argc <= 0) bb_show_usage();
}
// Loop through everything we're supposed to umount, and do so.
for(;;) {
int curstat;
// Do we already know what to umount this time through the loop?
if(m) safe_strncpy(path,m->dir,PATH_MAX);
// For umount -a, end of mtab means time to exit.
else if(opt & OPT_ALL) break;
// Get next command line argument (and look it up in mtab list)
else if(!argc--) break;
else {
// Get next command line argument (and look it up in mtab list)
realpath(*argv++, path);
for(m = mtl; m; m = m->next)
if(!strcmp(path, m->dir) || !strcmp(path, m->device))
break;
}
// Let's ask the thing nicely to unmount.
curstat = umount(path);
// Force the unmount, if necessary.
if(curstat && doForce) {
curstat = umount2(path, doForce);
if(curstat)
bb_error_msg_and_die("forced umount of %s failed!", path);
}
// If still can't umount, maybe remount read-only?
if (curstat && (opt & OPT_REMOUNT) && errno == EBUSY && m) {
curstat = mount(m->device, path, NULL, MS_REMOUNT|MS_RDONLY, NULL);
bb_error_msg(curstat ? "Cannot remount %s read-only" :
"%s busy - remounted read-only", m->device);
}
/* De-allocate the loop device. This ioctl should be ignored on any
* non-loop block devices. */
if(ENABLE_FEATURE_MOUNT_LOOP && !(opt & OPT_DONTFREELOOP) && m)
del_loop(m->device);
if(curstat) {
/* Yes, the ENABLE is redundant here, but the optimizer for ARM
* can't do simple constant propagation in local variables... */
if(ENABLE_FEATURE_MTAB_SUPPORT && !(opt & OPT_NO_MTAB) && m)
erase_mtab(m->dir);
status = EXIT_FAILURE;
bb_perror_msg("Couldn't umount %s", path);
}
// Find next matching mtab entry for -a or umount /dev
while(m && (m = m->next))
if((opt & OPT_ALL) || !strcmp(path,m->device))
break;
}
// Free mtab list if necessary
if(ENABLE_FEATURE_CLEAN_UP) {
while(mtl) {
m=mtl->next;
free(mtl->device);
free(mtl->dir);
free(mtl);
mtl=m;
}
}
return status;
}
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