1 /* vi: set sw=4 ts=4: */
3 * Mini umount implementation for busybox
6 * Copyright (C) 1999,2000 by Lineo, inc.
7 * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
27 #include <sys/mount.h>
32 static const char umount_usage[] =
33 "umount [flags] filesystem|directory\n\n"
34 "Flags:\n" "\t-a:\tUnmount all file systems"
36 " in /etc/mtab\n\t-n:\tDon't erase /etc/mtab entries\n"
40 "\t-r:\tTry to remount devices as read-only if mount is busy\n"
41 #if defined BB_FEATURE_MOUNT_LOOP
42 "\t-f:\tDo not free loop device (if a loop device has been used)\n"
46 struct _mtab_entry_t {
49 struct _mtab_entry_t *next;
52 static struct _mtab_entry_t *mtab_cache = NULL;
56 #if defined BB_FEATURE_MOUNT_LOOP
57 static int freeLoop = TRUE;
59 static int useMtab = TRUE;
60 static int umountAll = FALSE;
61 static int doRemount = FALSE;
62 extern const char mtab_file[]; /* Defined in utility.c */
66 /* These functions are here because the getmntent functions do not appear
67 * to be re-entrant, which leads to all sorts of problems when we try to
68 * use them recursively - randolph
70 * TODO: Perhaps switch to using Glibc's getmntent_r
75 struct _mtab_entry_t *entry = NULL;
79 if (mtab_cache != NULL)
82 if ((fp = setmntent(mtab_file, "r")) == NULL) {
83 fprintf(stderr, "Cannot open %s\n", mtab_file);
86 while ((e = getmntent(fp))) {
87 entry = xmalloc(sizeof(struct _mtab_entry_t));
88 entry->device = strdup(e->mnt_fsname);
89 entry->mountpt = strdup(e->mnt_dir);
90 entry->next = mtab_cache;
96 char *mtab_getinfo(const char *match, const char which)
98 struct _mtab_entry_t *cur = mtab_cache;
101 if (strcmp(cur->mountpt, match) == 0 ||
102 strcmp(cur->device, match) == 0) {
103 if (which == MTAB_GETMOUNTPT) {
107 if (strcmp(cur->device, "/dev/root") == 0) {
108 /* Adjusts device to be the real root device,
109 * or leaves device alone if it can't find it */
110 find_real_root_device_name( cur->device);
111 return ( cur->device);
122 char *mtab_first(void **iter)
124 struct _mtab_entry_t *mtab_iter;
128 mtab_iter = mtab_cache;
129 *iter = (void *) mtab_iter;
130 return mtab_next(iter);
133 char *mtab_next(void **iter)
137 if (iter == NULL || *iter == NULL)
139 mp = ((struct _mtab_entry_t *) (*iter))->mountpt;
140 *iter = (void *) ((struct _mtab_entry_t *) (*iter))->next;
144 /* Don't bother to clean up, since exit() does that
145 * automagically, so we can save a few bytes */
149 struct _mtab_entry_t *this, *next;
164 static int do_umount(const char *name, int useMtab)
167 char *blockDevice = mtab_getinfo(name, MTAB_GETDEVICE);
169 if (blockDevice && strcmp(blockDevice, name) == 0)
170 name = mtab_getinfo(blockDevice, MTAB_GETMOUNTPT);
172 status = umount(name);
174 #if defined BB_FEATURE_MOUNT_LOOP
175 if (freeLoop == TRUE && blockDevice != NULL && !strncmp("/dev/loop", blockDevice, 9))
176 /* this was a loop device, delete it */
177 del_loop(blockDevice);
179 if (status != 0 && doRemount == TRUE && errno == EBUSY) {
180 status = mount(blockDevice, name, NULL,
181 MS_MGC_VAL | MS_REMOUNT | MS_RDONLY, NULL);
183 fprintf(stderr, "umount: %s busy - remounted read-only\n",
185 /* TODO: update mtab if BB_MTAB is defined */
187 fprintf(stderr, "umount: Cannot remount %s read-only\n",
201 static int umount_all(int useMtab)
207 for (mountpt = mtab_first(&iter); mountpt; mountpt = mtab_next(&iter)) {
208 /* Never umount /proc on a umount -a */
209 if (strstr(mountpt, "proc")!= NULL)
211 status = do_umount(mountpt, useMtab);
213 /* Don't bother retrying the umount on busy devices */
214 if (errno == EBUSY) {
218 status = do_umount(mountpt, useMtab);
220 printf("Couldn't umount %s on %s: %s\n",
221 mountpt, mtab_getinfo(mountpt, MTAB_GETDEVICE),
229 extern int umount_main(int argc, char **argv)
235 /* Parse any options */
236 while (--argc > 0 && **(++argv) == '-') {
242 #if defined BB_FEATURE_MOUNT_LOOP
256 break; /* ignore -v */
263 if (umountAll == TRUE) {
264 exit(umount_all(useMtab));
266 if (do_umount(*argv, useMtab) == 0)