+/* vi: set sw=4 ts=4: */
/*
* Mini umount implementation for busybox
*
+ * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
+ * Copyright (C) 2005 by Rob Landley <rob@landley.net>
*
- * Copyright (C) 1999 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
- *
+ * Licensed under GPLv2, see file LICENSE in this source tree.
*/
-#include "internal.h"
-#include <stdio.h>
-#include <sys/mount.h>
-#include <mntent.h>
-#include <fstab.h>
-#include <errno.h>
-
-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"
-#endif
-;
+//usage:#define umount_trivial_usage
+//usage: "[OPTIONS] FILESYSTEM|DIRECTORY"
+//usage:#define umount_full_usage "\n\n"
+//usage: "Unmount file systems\n"
+//usage: IF_FEATURE_UMOUNT_ALL(
+//usage: "\n -a Unmount all file systems" IF_FEATURE_MTAB_SUPPORT(" in /etc/mtab")
+//usage: )
+//usage: IF_FEATURE_MTAB_SUPPORT(
+//usage: "\n -n Don't erase /etc/mtab entries"
+//usage: )
+//usage: "\n -r Try to remount devices as read-only if mount is busy"
+//usage: "\n -l Lazy umount (detach filesystem)"
+//usage: "\n -f Force umount (i.e., unreachable NFS server)"
+//usage: IF_FEATURE_MOUNT_LOOP(
+//usage: "\n -D Don't free loop device even if it has been used"
+//usage: )
+//usage:
+//usage:#define umount_example_usage
+//usage: "$ umount /dev/hdc1\n"
+#include <mntent.h>
+#include <sys/mount.h>
+#include "libbb.h"
-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__)
+// TODO: This does not belong here.
+/* 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 -t -i
+ * bbox always acts as if -d is present.
+ * -D can be used to suppress it (bbox extension).
+ * Rationale:
+ * (1) util-linux's umount does it if "loop=..." is seen in /etc/mtab:
+ * thus, on many systems, bare umount _does_ drop loop devices.
+ * (2) many users request this feature.
+ */
+#define OPTION_STRING "fldDnra" "vt:i"
+#define OPT_FORCE (1 << 0) // Same as MNT_FORCE
+#define OPT_LAZY (1 << 1) // Same as MNT_DETACH
+//#define OPT_FREE_LOOP (1 << 2) // -d is assumed always present
+#define OPT_DONT_FREE_LOOP (1 << 3)
+#define OPT_NO_MTAB (1 << 4)
+#define OPT_REMOUNT (1 << 5)
+#define OPT_ALL (ENABLE_FEATURE_UMOUNT_ALL ? (1 << 6) : 0)
+
+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;
+ 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;
+
+ // MNT_FORCE and MNT_DETACH (from linux/fs.h) must match
+ // OPT_FORCE and OPT_LAZY, otherwise this trick won't work:
+ 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, bb_common_bufsiz1, sizeof(bb_common_bufsiz1))) {
+ /* 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_DONT_FREE_LOOP) && 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;
+ }
+ }
+
+ return status;
+}
projects / oweals / busybox.git / blobdiff