/* vi: set sw=4 ts=4: */ /* * Mini umount implementation for busybox * * * Copyright (C) 1999,2000,2001 by Lineo, inc. * Written by Erik Andersen , * * 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 #include #include #include #include #include #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 BB_FEATURE_MOUNT_FORCE static int doForce = FALSE; #endif #if defined BB_FEATURE_MOUNT_LOOP static int freeLoop = TRUE; #endif #if defined BB_FEATURE_MTAB_SUPPORT static int useMtab = TRUE; #endif 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 */ static 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) { error_msg("Cannot open %s", 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 BB_FEATURE_MTAB_SUPPORT 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 BB_FEATURE_CLEAN_UP static 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 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) { error_msg_and_die("forced umount of %s failed!", 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) { error_msg("%s busy - remounted read-only", blockDevice); } else { error_msg("Cannot remount %s read-only", blockDevice); } } if (status == 0) { #if defined BB_FEATURE_MTAB_SUPPORT if (useMtab == TRUE) 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) { 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]; if (argc < 2) { show_usage(); } #ifdef BB_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 BB_FEATURE_MOUNT_LOOP case 'l': freeLoop = FALSE; break; #endif #ifdef BB_FEATURE_MTAB_SUPPORT 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: show_usage(); } } mtab_read(); if (umountAll == TRUE) { if (umount_all() == TRUE) return EXIT_SUCCESS; else return EXIT_FAILURE; } if (realpath(*argv, path) == NULL) perror_msg_and_die("%s", path); if (do_umount(path) == TRUE) return EXIT_SUCCESS; perror_msg_and_die("%s", *argv); }