| /* vi: set sw=4 ts=4: */ |
| /* |
| * Mini umount implementation for busybox |
| * |
| * |
| * Copyright (C) 1999,2000 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 <mntent.h> |
| #include <errno.h> |
| #include <sys/mount.h> |
| #include <linux/unistd.h> |
| |
| |
| /* Include our own version of umount2 if we need it... */ |
| #ifndef __NR_umount2 |
| #define __NR_umount2 52 |
| #define MNT_FORCE 1 |
| #define MS_MGC_VAL 0xc0ed0000 /* Magic number indicatng "new" flags */ |
| #define MS_REMOUNT 32 /* Alter flags of a mounted FS. */ |
| #define MS_RDONLY 1 /* Mount read-only. */ |
| |
| #endif |
| static _syscall2(int, umount2, const char *, special_file, int, flags); |
| |
| |
| static const char umount_usage[] = |
| "umount [flags] filesystem|directory\n" |
| #ifndef BB_FEATURE_TRIVIAL_HELP |
| "Unmount file systems\n" |
| "\nFlags:\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 |
| "\t-r:\tTry to remount devices as read-only if mount is busy\n" |
| #if defined BB_FEATURE_MOUNT_FORCE |
| "\t-f:\tForce filesystem umount (i.e. unreachable NFS server)\n" |
| #endif |
| #if defined BB_FEATURE_MOUNT_LOOP |
| "\t-l:\tDo not free loop device (if a loop device has been used)\n" |
| #endif |
| #endif |
| ; |
| |
| struct _mtab_entry_t { |
| char *device; |
| char *mountpt; |
| struct _mtab_entry_t *next; |
| }; |
| |
| static struct _mtab_entry_t *mtab_cache = NULL; |
| |
| |
| |
| #if defined BB_FEATURE_MOUNT_FORCE |
| static int doForce = FALSE; |
| #endif |
| #if defined BB_FEATURE_MOUNT_LOOP |
| static int freeLoop = TRUE; |
| #endif |
| static int useMtab = TRUE; |
| static int umountAll = FALSE; |
| static int doRemount = FALSE; |
| extern const char mtab_file[]; /* Defined in utility.c */ |
| |
| |
| |
| /* 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 |
| */ |
| void mtab_read(void) |
| { |
| struct _mtab_entry_t *entry = NULL; |
| struct mntent *e; |
| FILE *fp; |
| |
| if (mtab_cache != NULL) |
| return; |
| |
| if ((fp = setmntent(mtab_file, "r")) == NULL) { |
| fprintf(stderr, "Cannot open %s\n", 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); |
| } |
| |
| 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 BB_MTAB |
| 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 */ |
| find_real_root_device_name( cur->device); |
| return ( cur->device); |
| } |
| #endif |
| return cur->device; |
| } |
| } |
| cur = cur->next; |
| } |
| return NULL; |
| } |
| |
| 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); |
| } |
| |
| 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; |
| } |
| |
| /* Don't bother to clean up, since exit() does that |
| * automagically, so we can save a few bytes */ |
| #if 0 |
| void mtab_free(void) |
| { |
| struct _mtab_entry_t *this, *next; |
| |
| this = mtab_cache; |
| while (this) { |
| next = this->next; |
| if (this->device) |
| free(this->device); |
| if (this->mountpt) |
| free(this->mountpt); |
| free(this); |
| this = next; |
| } |
| } |
| #endif |
| |
| static int do_umount(const char *name, int useMtab) |
| { |
| 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 BB_FEATURE_MOUNT_LOOP |
| if (freeLoop == TRUE && blockDevice != NULL && !strncmp("/dev/loop", blockDevice, 9)) |
| /* this was a loop device, delete it */ |
| del_loop(blockDevice); |
| #endif |
| #if defined BB_FEATURE_MOUNT_FORCE |
| if (status != 0 && doForce == TRUE) { |
| status = umount2(blockDevice, MNT_FORCE); |
| if (status != 0) { |
| fatalError("umount: forced umount of %s failed!\n", blockDevice); |
| } |
| } |
| #endif |
| if (status != 0 && doRemount == TRUE && errno == EBUSY) { |
| status = mount(blockDevice, name, NULL, |
| MS_MGC_VAL | MS_REMOUNT | MS_RDONLY, NULL); |
| if (status == 0) { |
| fprintf(stderr, "umount: %s busy - remounted read-only\n", |
| blockDevice); |
| } else { |
| fprintf(stderr, "umount: Cannot remount %s read-only\n", |
| blockDevice); |
| } |
| } |
| if (status == 0) { |
| #if defined BB_MTAB |
| if (useMtab == TRUE) |
| erase_mtab(name); |
| #endif |
| return (TRUE); |
| } |
| return (FALSE); |
| } |
| |
| static int umount_all(int useMtab) |
| { |
| 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; |
| status = do_umount(mountpt, useMtab); |
| if (status != 0) { |
| /* Don't bother retrying the umount on busy devices */ |
| if (errno == EBUSY) { |
| perror(mountpt); |
| continue; |
| } |
| status = do_umount(mountpt, useMtab); |
| if (status != 0) { |
| printf("Couldn't umount %s on %s: %s\n", |
| mountpt, mtab_getinfo(mountpt, MTAB_GETDEVICE), |
| strerror(errno)); |
| } |
| } |
| } |
| return (status); |
| } |
| |
| 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; |
| #if defined BB_FEATURE_MOUNT_LOOP |
| case 'l': |
| freeLoop = FALSE; |
| break; |
| #endif |
| #ifdef BB_MTAB |
| case 'n': |
| useMtab = FALSE; |
| break; |
| #endif |
| #ifdef BB_FEATURE_MOUNT_FORCE |
| case 'f': |
| doForce = TRUE; |
| break; |
| #endif |
| case 'r': |
| doRemount = TRUE; |
| break; |
| case 'v': |
| break; /* ignore -v */ |
| default: |
| usage(umount_usage); |
| } |
| } |
| |
| mtab_read(); |
| if (umountAll == TRUE) { |
| exit(umount_all(useMtab)); |
| } |
| if (do_umount(*argv, useMtab) == 0) |
| exit(TRUE); |
| perror("umount"); |
| return(FALSE); |
| } |
| |