| /* vi: set sw=4 ts=4: */ |
| /* |
| * Mini umount implementation for busybox |
| * |
| * Copyright (C) 1999-2003 by Erik Andersen <andersen@codepoet.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 <limits.h> |
| #include <stdio.h> |
| #include <mntent.h> |
| #include <errno.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include "busybox.h" |
| |
| /* Teach libc5 about realpath -- it includes it but the |
| * prototype is missing... */ |
| #if (__GLIBC__ <= 2) && (__GLIBC_MINOR__ < 1) |
| extern char *realpath(const char *path, char *resolved_path); |
| #endif |
| |
| static const int MNT_FORCE = 1; |
| static const int MS_MGC_VAL = 0xc0ed0000; /* Magic number indicatng "new" flags */ |
| static const int MS_REMOUNT = 32; /* Alter flags of a mounted FS. */ |
| static const int MS_RDONLY = 1; /* Mount read-only. */ |
| |
| extern int mount (__const char *__special_file, __const char *__dir, |
| __const char *__fstype, unsigned long int __rwflag, |
| __const void *__data); |
| extern int umount (__const char *__special_file); |
| extern int umount2 (__const char *__special_file, int __flags); |
| |
| struct _mtab_entry_t { |
| char *device; |
| char *mountpt; |
| struct _mtab_entry_t *next; |
| }; |
| |
| static struct _mtab_entry_t *mtab_cache = NULL; |
| |
| |
| |
| #if defined CONFIG_FEATURE_MOUNT_FORCE |
| static int doForce = FALSE; |
| #endif |
| #if defined CONFIG_FEATURE_MOUNT_LOOP |
| static int freeLoop = TRUE; |
| #endif |
| #if defined CONFIG_FEATURE_MTAB_SUPPORT |
| static int useMtab = TRUE; |
| #endif |
| static int umountAll = FALSE; |
| static int doRemount = FALSE; |
| |
| |
| |
| /* These functions are here because the getmntent functions do not appear |
| * to be re-entrant, which leads to all sorts of problems when we try to |
| * use them recursively - randolph |
| * |
| * TODO: Perhaps switch to using Glibc's getmntent_r |
| * -Erik |
| */ |
| static void mtab_read(void) |
| { |
| struct _mtab_entry_t *entry = NULL; |
| struct mntent *e; |
| FILE *fp; |
| |
| if (mtab_cache != NULL) |
| return; |
| |
| if ((fp = setmntent(bb_path_mtab_file, "r")) == NULL) { |
| bb_error_msg("Cannot open %s", bb_path_mtab_file); |
| return; |
| } |
| while ((e = getmntent(fp))) { |
| entry = xmalloc(sizeof(struct _mtab_entry_t)); |
| entry->device = strdup(e->mnt_fsname); |
| entry->mountpt = strdup(e->mnt_dir); |
| entry->next = mtab_cache; |
| mtab_cache = entry; |
| } |
| endmntent(fp); |
| } |
| |
| static char *mtab_getinfo(const char *match, const char which) |
| { |
| struct _mtab_entry_t *cur = mtab_cache; |
| |
| while (cur) { |
| if (strcmp(cur->mountpt, match) == 0 || |
| strcmp(cur->device, match) == 0) { |
| if (which == MTAB_GETMOUNTPT) { |
| return cur->mountpt; |
| } else { |
| #if !defined CONFIG_FEATURE_MTAB_SUPPORT |
| if (strcmp(cur->device, "rootfs") == 0) { |
| continue; |
| } else if (strcmp(cur->device, "/dev/root") == 0) { |
| /* Adjusts device to be the real root device, |
| * or leaves device alone if it can't find it */ |
| cur->device = find_real_root_device_name(cur->device); |
| } |
| #endif |
| return cur->device; |
| } |
| } |
| cur = cur->next; |
| } |
| return NULL; |
| } |
| |
| static char *mtab_next(void **iter) |
| { |
| char *mp; |
| |
| if (iter == NULL || *iter == NULL) |
| return NULL; |
| mp = ((struct _mtab_entry_t *) (*iter))->mountpt; |
| *iter = (void *) ((struct _mtab_entry_t *) (*iter))->next; |
| return mp; |
| } |
| |
| static char *mtab_first(void **iter) |
| { |
| struct _mtab_entry_t *mtab_iter; |
| |
| if (!iter) |
| return NULL; |
| mtab_iter = mtab_cache; |
| *iter = (void *) mtab_iter; |
| return mtab_next(iter); |
| } |
| |
| /* Don't bother to clean up, since exit() does that |
| * automagically, so we can save a few bytes */ |
| #ifdef CONFIG_FEATURE_CLEAN_UP |
| static void mtab_free(void) |
| { |
| struct _mtab_entry_t *this, *next; |
| |
| this = mtab_cache; |
| while (this) { |
| next = this->next; |
| free(this->device); |
| free(this->mountpt); |
| free(this); |
| this = next; |
| } |
| } |
| #endif |
| |
| static int do_umount(const char *name) |
| { |
| int status; |
| char *blockDevice = mtab_getinfo(name, MTAB_GETDEVICE); |
| |
| if (blockDevice && strcmp(blockDevice, name) == 0) |
| name = mtab_getinfo(blockDevice, MTAB_GETMOUNTPT); |
| |
| status = umount(name); |
| |
| #if defined CONFIG_FEATURE_MOUNT_LOOP |
| if (freeLoop && blockDevice != NULL && !strncmp("/dev/loop", blockDevice, 9)) |
| /* this was a loop device, delete it */ |
| del_loop(blockDevice); |
| #endif |
| #if defined CONFIG_FEATURE_MOUNT_FORCE |
| if (status != 0 && doForce) { |
| status = umount2(blockDevice, MNT_FORCE); |
| if (status != 0) { |
| bb_error_msg_and_die("forced umount of %s failed!", blockDevice); |
| } |
| } |
| #endif |
| if (status != 0 && doRemount && errno == EBUSY) { |
| status = mount(blockDevice, name, NULL, |
| MS_MGC_VAL | MS_REMOUNT | MS_RDONLY, NULL); |
| if (status == 0) { |
| bb_error_msg("%s busy - remounted read-only", blockDevice); |
| } else { |
| bb_error_msg("Cannot remount %s read-only", blockDevice); |
| } |
| } |
| if (status == 0) { |
| #if defined CONFIG_FEATURE_MTAB_SUPPORT |
| if (useMtab) |
| erase_mtab(name); |
| #endif |
| return (TRUE); |
| } |
| return (FALSE); |
| } |
| |
| static int umount_all(void) |
| { |
| int status = TRUE; |
| char *mountpt; |
| void *iter; |
| |
| for (mountpt = mtab_first(&iter); mountpt; mountpt = mtab_next(&iter)) { |
| /* Never umount /proc on a umount -a */ |
| if (strstr(mountpt, "proc")!= NULL) |
| continue; |
| if (!do_umount(mountpt)) { |
| /* Don't bother retrying the umount on busy devices */ |
| if (errno == EBUSY) { |
| bb_perror_msg("%s", mountpt); |
| status = FALSE; |
| continue; |
| } |
| if (!do_umount(mountpt)) { |
| printf("Couldn't umount %s on %s: %s\n", |
| mountpt, mtab_getinfo(mountpt, MTAB_GETDEVICE), |
| strerror(errno)); |
| status = FALSE; |
| } |
| } |
| } |
| return (status); |
| } |
| |
| extern int umount_main(int argc, char **argv) |
| { |
| char path[PATH_MAX], result = 0; |
| |
| if (argc < 2) { |
| bb_show_usage(); |
| } |
| #ifdef CONFIG_FEATURE_CLEAN_UP |
| atexit(mtab_free); |
| #endif |
| |
| /* Parse any options */ |
| while (--argc > 0 && **(++argv) == '-') { |
| while (*++(*argv)) |
| switch (**argv) { |
| case 'a': |
| umountAll = TRUE; |
| break; |
| #if defined CONFIG_FEATURE_MOUNT_LOOP |
| case 'l': |
| freeLoop = FALSE; |
| break; |
| #endif |
| #ifdef CONFIG_FEATURE_MTAB_SUPPORT |
| case 'n': |
| useMtab = FALSE; |
| break; |
| #endif |
| #ifdef CONFIG_FEATURE_MOUNT_FORCE |
| case 'f': |
| doForce = TRUE; |
| break; |
| #endif |
| case 'r': |
| doRemount = TRUE; |
| break; |
| case 'v': |
| break; /* ignore -v */ |
| default: |
| bb_show_usage(); |
| } |
| } |
| |
| mtab_read(); |
| if (umountAll) { |
| if (umount_all()) |
| return EXIT_SUCCESS; |
| else |
| return EXIT_FAILURE; |
| } |
| |
| do { |
| if (realpath(*argv, path) != NULL) |
| if (do_umount(path)) |
| continue; |
| bb_perror_msg("%s", path); |
| result++; |
| } while (--argc > 0 && ++argv); |
| return result; |
| } |