mirror of
https://github.com/sheumann/hush.git
synced 2024-09-11 09:54:31 +00:00
can never be made because useMtab is initialized to 0, and all the other assignments of that variable assign 0 to it. Any compiler that can perform simple constant propogation on local variables will optimize away if statements testing against that variable, thus the call to erase_mtab() will never be made. When compiling for arm using gcc 3.3.3 with FEATURE_MTAB_SUPPORT disabled, the linker complains that it can't find erase_mtab(). The arm optimizer isn't exactly the brightest member of the family, and apparently needs to be hit over the head with a hammer to get its' attention...
145 lines
4.1 KiB
C
145 lines
4.1 KiB
C
/* 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 "busybox.h"
|
|
|
|
extern int umount_main(int argc, char **argv)
|
|
{
|
|
int doForce = 0;
|
|
int freeLoop = ENABLE_FEATURE_MOUNT_LOOP;
|
|
int useMtab = ENABLE_FEATURE_MTAB_SUPPORT;
|
|
int umountAll = FALSE;
|
|
int doRemount = FALSE;
|
|
char path[2*PATH_MAX];
|
|
struct mntent me;
|
|
FILE *fp;
|
|
int status=EXIT_SUCCESS;
|
|
struct mtab_list {
|
|
char *dir;
|
|
char *device;
|
|
struct mtab_list *next;
|
|
} *mtl, *m;
|
|
|
|
if(argc < 2) bb_show_usage();
|
|
|
|
/* Parse any options */
|
|
while (--argc > 0 && **(++argv) == '-') {
|
|
while (*++(*argv)) {
|
|
if(**argv=='a') umountAll = TRUE;
|
|
else if(ENABLE_FEATURE_MOUNT_LOOP && **argv=='D') freeLoop = FALSE;
|
|
else if(ENABLE_FEATURE_MTAB_SUPPORT && **argv=='n') useMtab = FALSE;
|
|
else if(**argv=='f') doForce = 1; // MNT_FORCE
|
|
else if(**argv=='l') doForce = 2; // MNT_DETACH
|
|
else if(**argv=='r') doRemount = TRUE;
|
|
else if(**argv=='v');
|
|
else bb_show_usage();
|
|
}
|
|
}
|
|
|
|
/* 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(!umountAll) m=0;
|
|
|
|
// Loop through everything we're supposed to umount, and do so.
|
|
for(;;) {
|
|
int curstat;
|
|
|
|
// Do we alrady know what to umount this time through the loop?
|
|
if(m) safe_strncpy(path,m->dir,PATH_MAX);
|
|
// For umountAll, end of mtab means time to exit.
|
|
else if(umountAll) 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 && doRemount && 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-allcate the loop device. This ioctl should be ignored on any
|
|
* non-loop block devices. */
|
|
if(ENABLE_FEATURE_MOUNT_LOOP && freeLoop && m)
|
|
del_loop(m->device);
|
|
|
|
if(curstat) {
|
|
/* Yes, the ENABLE is redundant here, but the optimizer for ARM
|
|
* can't do simple constant propogation in local variables... */
|
|
if(ENABLE_FEATURE_MTAB_SUPPORT && useMtab && m) erase_mtab(m->dir);
|
|
status = EXIT_FAILURE;
|
|
bb_perror_msg("Couldn't umount %s\n", path);
|
|
}
|
|
// Find next matching mtab entry for -a or umount /dev
|
|
while(m && (m = m->next))
|
|
if(umountAll || !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;
|
|
}
|