X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=util-linux%2Fumount.c;h=7063a474d1b7822be6c014cda98c406c6af71e0c;hb=dcf6de552a15c1e7bddb32f1028ceb6214915425;hp=625fcfab94d6813466ecff888afd91bbfeadfc08;hpb=b0e9a709ba1ae1724d413a77f5b67b1a3e6c6cb7;p=oweals%2Fbusybox.git diff --git a/util-linux/umount.c b/util-linux/umount.c index 625fcfab9..7063a474d 100644 --- a/util-linux/umount.c +++ b/util-linux/umount.c @@ -1,96 +1,156 @@ +/* vi: set sw=4 ts=4: */ /* * Mini umount implementation for busybox * - * Copyright (C) 1998 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 + * Copyright (C) 1999-2004 by Erik Andersen + * Copyright (C) 2005 by Rob Landley * + * Licensed under GPL version 2, see file LICENSE in this tarball for details. */ -#include "internal.h" -#include -#include #include -#include -#include +#include +#include "libbb.h" -const char umount_usage[] = -"Usage: umount filesystem\n" -" or: umount directory\n" -" or: umount -a" -"to unmount all mounted file systems.\n"; +#define OPTION_STRING "flDnravdt:" +#define OPT_FORCE 1 +#define OPT_LAZY 2 +#define OPT_DONTFREELOOP 4 +#define OPT_NO_MTAB 8 +#define OPT_REMOUNT 16 +#define OPT_ALL (ENABLE_FEATURE_UMOUNT_ALL ? 32 : 0) -static int -umount_all() +int umount_main(int argc, char **argv); +int umount_main(int argc, char **argv) { - int status; - struct mntent *m; - FILE *mountTable; - - if ((mountTable = setmntent ("/proc/mounts", "r"))) { - while ((m = getmntent (mountTable)) != 0) { - char *blockDevice = m->mnt_fsname; - if (strcmp (blockDevice, "/dev/root") == 0) - blockDevice = (getfsfile ("/"))->fs_spec; - status=umount (m->mnt_dir); - if (status!=0) { - /* Don't bother retrying the umount on busy devices */ - if (errno==EBUSY) { - perror(m->mnt_dir); - continue; - } - printf ("Trying to umount %s failed: %s\n", - m->mnt_dir, strerror(errno)); - printf ("Instead trying to umount %s\n", blockDevice); - status=umount (blockDevice); - if (status!=0) { - printf ("Couldn't umount %s on %s (type %s): %s\n", - blockDevice, m->mnt_dir, m->mnt_type, strerror(errno)); - } + int doForce; + char path[2*PATH_MAX]; + struct mntent me; + FILE *fp; + char *fstype = 0; + int status = EXIT_SUCCESS; + unsigned opt; + struct mtab_list { + char *dir; + char *device; + struct mtab_list *next; + } *mtl, *m; + + /* Parse any options */ + + opt = getopt32(argc, 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 = 0; + + /* 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("cannot open %s", bb_path_mtab_file); + } else { + while (getmntent_r(fp, &me, path, sizeof(path))) { + /* 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; } - } - endmntent (mountTable); - } - return( TRUE); -} + endmntent(fp); + } -extern int -umount_main(int argc, char * * argv) -{ + /* If we're not umounting all, we need at least one argument. */ + if (!(opt & OPT_ALL) && !fstype) { + m = 0; + if (!argc) bb_show_usage(); + } + + // Loop through everything we're supposed to umount, and do so. + for (;;) { + int curstat; + char *zapit = *argv; - if (argc < 2) { - usage( umount_usage); - } - argc--; - argv++; - - /* Parse any options */ - while (**argv == '-') { - while (*++(*argv)) switch (**argv) { - case 'a': - exit ( umount_all() ); - break; - default: - usage( umount_usage); + // 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; + // Get next command line argument (and look it up in mtab list) + else if (!argc--) break; + else { + argv++; + realpath(zapit, path); + for (m = mtl; m; m = m->next) + if (!strcmp(path, m->dir) || !strcmp(path, m->device)) + break; + } + // 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 (curstat) + bb_error_msg("forced umount of %s failed!", zapit); + } + + // If still can't umount, maybe remount read-only? + if (curstat && (opt & OPT_REMOUNT) && errno == EBUSY && m) { + curstat = mount(m->device, zapit, NULL, MS_REMOUNT|MS_RDONLY, NULL); + bb_error_msg(curstat ? "cannot remount %s read-only" : + "%s busy - remounted read-only", m->device); + } + + if (curstat) { + status = EXIT_FAILURE; + bb_perror_msg("cannot umount %s", 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_DONTFREELOOP) && 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. + while (m && (m = m->next)) + if ((opt & OPT_ALL) || !strcmp(path, m->device)) + break; } - } - if ( umount(*argv) == 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; + } + } + + return status; +}