X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=util-linux%2Fumount.c;h=0662cea1b48c4e6b3c4db6cfe4910731c6d39b3d;hb=319fe129a15278193625eeb05752511d576c5588;hp=3e23b9705edf3e660f277fca16eadf945d496ded;hpb=c4cef5ab063d7abb604d48610424566202dcade0;p=oweals%2Fbusybox.git diff --git a/util-linux/umount.c b/util-linux/umount.c index 3e23b9705..0662cea1b 100644 --- a/util-linux/umount.c +++ b/util-linux/umount.c @@ -2,288 +2,172 @@ /* * Mini umount implementation for busybox * + * Copyright (C) 1999-2004 by Erik Andersen + * Copyright (C) 2005 by Rob Landley * - * 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 - * + * Licensed under GPL version 2, see file LICENSE in this tarball for details. */ -#include #include -#include -#include -#include -#include "busybox.h" - - -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; - - +#include "libbb.h" -#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 - */ -void mtab_read(void) +#if defined(__dietlibc__) +/* 16.12.2006, Sampo Kellomaki (sampo@iki.fi) + * dietlibc-0.30 does not have implementation of getmntent_r() */ +static struct mntent *getmntent_r(FILE* stream, struct mntent* result, + char* buffer UNUSED_PARAM, int bufsize UNUSED_PARAM) { - 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); + struct mntent* ment = getmntent(stream); + return memcpy(result, ment, sizeof(*ment)); } +#endif -char *mtab_getinfo(const char *match, const char which) +/* ignored: -v -d -t -i */ +#define OPTION_STRING "fldnra" "vdt:i" +#define OPT_FORCE (1 << 0) +#define OPT_LAZY (1 << 1) +#define OPT_FREELOOP (1 << 2) +#define OPT_NO_MTAB (1 << 3) +#define OPT_REMOUNT (1 << 4) +#define OPT_ALL (ENABLE_FEATURE_UMOUNT_ALL ? (1 << 5) : 0) + +// These constants from linux/fs.h must match OPT_FORCE and OPT_LAZY, +// otherwise "doForce" trick below won't work! +//#define MNT_FORCE 0x00000001 /* Attempt to forcibly umount */ +//#define MNT_DETACH 0x00000002 /* Just detach from the tree */ + +int umount_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int umount_main(int argc UNUSED_PARAM, char **argv) { - 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 */ - find_real_root_device_name( cur->device); - return ( cur->device); - } -#endif - return cur->device; - } + int doForce; + char *const path = xmalloc(PATH_MAX + 2); /* to save stack */ + struct mntent me; + FILE *fp; + char *fstype = NULL; + int status = EXIT_SUCCESS; + unsigned opt; + struct mtab_list { + char *dir; + char *device; + struct mtab_list *next; + } *mtl, *m; + + opt = getopt32(argv, OPTION_STRING, &fstype); + //argc -= optind; + argv += optind; + doForce = MAX((opt & OPT_FORCE), (opt & OPT_LAZY)); + + /* 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 = NULL; + + // 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). + fp = setmntent(bb_path_mtab_file, "r"); + if (!fp) { + if (opt & OPT_ALL) + bb_error_msg_and_die("can't open %s", bb_path_mtab_file); + } else { + while (getmntent_r(fp, &me, path, PATH_MAX)) { + /* Match fstype if passed */ + if (fstype && match_fstype(&me, fstype)) + continue; + m = xmalloc(sizeof(struct mtab_list)); + m->next = mtl; + m->device = xstrdup(me.mnt_fsname); + m->dir = xstrdup(me.mnt_dir); + mtl = m; } - cur = cur->next; + endmntent(fp); } - 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 */ -#ifdef BB_FEATURE_CLEAN_UP -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; + // If we're not umounting all, we need at least one argument. + if (!(opt & OPT_ALL) && !fstype) { + if (!argv[0]) + bb_show_usage(); + m = NULL; } -} -#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); + // Loop through everything we're supposed to umount, and do so. + for (;;) { + int curstat; + char *zapit = *argv; + + // Do we already know what to umount this time through the loop? + if (m) + safe_strncpy(path, m->dir, PATH_MAX); + // For umount -a, end of mtab means time to exit. + else if (opt & OPT_ALL) + break; + // Use command line argument (and look it up in mtab list) + else { + if (!zapit) + break; + argv++; + realpath(zapit, path); + for (m = mtl; m; m = m->next) + if (!strcmp(path, m->dir) || !strcmp(path, m->device)) + break; } - } - 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; + // If we couldn't find this sucker in /etc/mtab, punt by passing our + // command line argument straight to the umount syscall. Otherwise, + // umount the directory even if we were given the block device. + if (m) zapit = m->dir; + + // Let's ask the thing nicely to unmount. + curstat = umount(zapit); + + // Force the unmount, if necessary. + if (curstat && doForce) + curstat = umount2(zapit, doForce); + + // If still can't umount, maybe remount read-only? + if (curstat) { + if ((opt & OPT_REMOUNT) && errno == EBUSY && m) { + // Note! Even if we succeed here, later we should not + // free loop device or erase mtab entry! + const char *msg = "%s busy - remounted read-only"; + curstat = mount(m->device, zapit, NULL, MS_REMOUNT|MS_RDONLY, NULL); + if (curstat) { + msg = "can't remount %s read-only"; + status = EXIT_FAILURE; + } + bb_error_msg(msg, m->device); + } else { + status = EXIT_FAILURE; + bb_perror_msg("can't %sumount %s", (doForce ? "forcibly " : ""), zapit); } + } else { + // De-allocate the loop device. This ioctl should be ignored on + // any non-loop block devices. + if (ENABLE_FEATURE_MOUNT_LOOP && (opt & OPT_FREELOOP) && m) + del_loop(m->device); + if (ENABLE_FEATURE_MTAB_SUPPORT && !(opt & OPT_NO_MTAB) && m) + erase_mtab(m->dir); } - } - return (status); -} -extern int umount_main(int argc, char **argv) -{ - 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; + // Find next matching mtab entry for -a or umount /dev + // Note this means that "umount /dev/blah" will unmount all instances + // of /dev/blah, not just the most recent. + if (m) while ((m = m->next) != NULL) + if ((opt & OPT_ALL) || !strcmp(path, m->device)) 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; + // 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; + } + free(path); } - if (do_umount(*argv) == TRUE) - return EXIT_SUCCESS; - perror_msg_and_die("%s", *argv); -} + return status; +}