X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=util-linux%2Fumount.c;h=7ba46eeb011c44fecb65d465d79f6634310b9a84;hb=38292b68c962b9d470fa4e577020749c8c69226d;hp=3bd86814e64263ae9454ce09e11bd51de3255089;hpb=1667fb4b633e8a250a17aea782baa18fc872d9d7;p=oweals%2Fbusybox.git diff --git a/util-linux/umount.c b/util-linux/umount.c index 3bd86814e..7ba46eeb0 100644 --- a/util-linux/umount.c +++ b/util-linux/umount.c @@ -1,142 +1,213 @@ +/* vi: set sw=4 ts=4: */ /* * Mini umount implementation for busybox * + * Copyright (C) 1999-2004 by Erik Andersen + * Copyright (C) 2005 by Rob Landley * - * Copyright (C) 1999 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 GPLv2, see file LICENSE in this source tree. */ - -#include "internal.h" -#include -#include #include -#include -#include - -static const char umount_usage[] = -"Usage: umount [flags] filesystem|directory\n\n" -"Flags:\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" +#include +/* Make sure we have all the new mount flags we actually try to use. */ +#ifndef MS_BIND +# define MS_BIND (1 << 12) +#endif +#ifndef MS_MOVE +# define MS_MOVE (1 << 13) +#endif +#ifndef MS_RECURSIVE +# define MS_RECURSIVE (1 << 14) +#endif +#ifndef MS_SILENT +# define MS_SILENT (1 << 15) +#endif +/* The shared subtree stuff, which went in around 2.6.15. */ +#ifndef MS_UNBINDABLE +# define MS_UNBINDABLE (1 << 17) +#endif +#ifndef MS_PRIVATE +# define MS_PRIVATE (1 << 18) +#endif +#ifndef MS_SLAVE +# define MS_SLAVE (1 << 19) +#endif +#ifndef MS_SHARED +# define MS_SHARED (1 << 20) +#endif +#ifndef MS_RELATIME +# define MS_RELATIME (1 << 21) +#endif +#include "libbb.h" +#ifndef PATH_MAX +# define PATH_MAX (4*1024) #endif -; - -static int useMtab = TRUE; -static int umountAll = FALSE; -extern const char mtab_file[]; /* Defined in utility.c */ -#if ! defined BB_MTAB -#define do_umount( blockDevice, useMtab) umount( blockDevice) -#else -static int -do_umount(const char* name, int useMtab) +#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) { - int status = umount(name); - - if ( status == 0 ) { - if ( useMtab==TRUE ) - erase_mtab(name); - return 0; - } - else - return( status); + struct mntent* ment = getmntent(stream); + return memcpy(result, ment, sizeof(*ment)); } #endif -static int -umount_all(int useMtab) +/* 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) { - int status; - struct mntent *m; - FILE *mountTable; - - if ((mountTable = setmntent (mtab_file, "r"))) { - while ((m = getmntent (mountTable)) != 0) { - char *blockDevice = m->mnt_fsname; -#if ! defined BB_MTAB - if (strcmp (blockDevice, "/dev/root") == 0) { - struct fstab* fstabItem; - fstabItem = getfsfile ("/"); - if (fstabItem != NULL) { - blockDevice = fstabItem->fs_spec; - } + int doForce; + char *const buf = xmalloc(PATH_MAX * 2 + 128); /* 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, buf, PATH_MAX * 2 + 128)) { + /* Match fstype if passed */ + if (!match_fstype(&me, fstype)) + continue; + m = xzalloc(sizeof(*m)); + m->next = mtl; + m->device = xstrdup(me.mnt_fsname); + m->dir = xstrdup(me.mnt_dir); + mtl = m; } -#endif - /* Don't umount /proc when doing umount -a */ - if (strcmp (blockDevice, "proc") == 0) - continue; - - status=do_umount (m->mnt_dir, useMtab); - if (status!=0) { - /* Don't bother retrying the umount on busy devices */ - if (errno==EBUSY) { - perror(m->mnt_dir); - continue; - } - status=do_umount (blockDevice, useMtab); - if (status!=0) { - printf ("Couldn't umount %s on %s (type %s): %s\n", - blockDevice, m->mnt_dir, m->mnt_type, strerror(errno)); - } + endmntent(fp); + } + + // 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; + } + + // Loop through everything we're supposed to umount, and do so. + for (;;) { + int curstat; + char *zapit = *argv; + char *path; + + // Do we already know what to umount this time through the loop? + if (m) + path = xstrdup(m->dir); + // 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++; + path = xmalloc_realpath(zapit); + if (path) { + for (m = mtl; m; m = m->next) + if (strcmp(path, m->dir) == 0 || strcmp(path, m->device) == 0) + break; + } } - } - endmntent (mountTable); - } - return( TRUE); -} + // 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; -extern int -umount_main(int argc, char** argv) -{ + // Let's ask the thing nicely to unmount. + curstat = umount(zapit); - if (argc < 2) { - usage( umount_usage); - } - - /* Parse any options */ - while (--argc > 0 && **(++argv) == '-') { - while (*++(*argv)) switch (**argv) { - case 'a': - umountAll = TRUE; - break; -#ifdef BB_MTAB - case 'n': - useMtab = FALSE; - break; -#endif - default: - usage( umount_usage); + // 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); + } + + // 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) + // NB: if m is non-NULL, path is non-NULL as well + if ((opt & OPT_ALL) || strcmp(path, m->device) == 0) + break; + } + free(path); } - } - - - if(umountAll==TRUE) { - exit(umount_all(useMtab)); - } - if ( do_umount(*argv,useMtab) == 0 ) - exit (TRUE); - else { - perror("umount"); - exit( FALSE); - } -} + // 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(buf); + } + + return status; +}