-#include "internal.h"
-#include <stdlib.h>
-#include <unistd.h>
-#include <errno.h>
-#include <string.h>
-#include <stdio.h>
-#include <mntent.h>
-#include <sys/mount.h>
+/* 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>
+ *
+ * Licensed under GPL version 2, see file LICENSE in this tarball for details.
+ */
-const char umount_usage[] = "umount {filesystem|directory}\n"
-"\tumount -a\n"
-"\n"
-"\tUnmount a filesystem.\n"
-"\t-a:\tUnmounts all mounted filesystems.\n";
+#include <mntent.h>
+#include "libbb.h"
-static char *
-stralloc(const char * string)
+#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 length = strlen(string) + 1;
- char * n = malloc(length);
- memcpy(n, string, length);
- return n;
+ struct mntent* ment = getmntent(stream);
+ return memcpy(result, ment, sizeof(*ment));
}
+#endif
+
+/* 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 */
-extern void
-erase_mtab(const char * name)
+int umount_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int umount_main(int argc UNUSED_PARAM, char **argv)
{
- struct mntent entries[100];
- int count = 0;
- FILE * mountTable = setmntent("/etc/mtab", "r");
- struct mntent * m;
-
- if ( mountTable == 0
- && (mountTable = setmntent("/proc/mounts", "r")) == 0 ) {
- name_and_error("/etc/mtab");
- return;
- }
+ 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;
- while ( (m = getmntent(mountTable)) != 0 ) {
- entries[count].mnt_fsname = stralloc(m->mnt_fsname);
- entries[count].mnt_dir = stralloc(m->mnt_dir);
- entries[count].mnt_type = stralloc(m->mnt_type);
- entries[count].mnt_opts = stralloc(m->mnt_opts);
- entries[count].mnt_freq = m->mnt_freq;
- entries[count].mnt_passno = m->mnt_passno;
- count++;
- }
- endmntent(mountTable);
- if ( (mountTable = setmntent("/etc/mtab", "w")) ) {
- int i;
- for ( i = 0; i < count; i++ ) {
- int result = ( strcmp(entries[i].mnt_fsname, name) == 0
- || strcmp(entries[i].mnt_dir, name) == 0 );
-
- if ( result )
+ 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;
- else
- addmntent(mountTable, &entries[i]);
+ 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);
+ endmntent(fp);
}
- else if ( errno != EROFS )
- name_and_error("/etc/mtab");
-}
-static int
-umount_all(int noMtab)
-{
- struct mntent entries[100];
- int count = 0;
- FILE * mountTable = setmntent("/etc/mtab", "r");
- struct mntent * m;
- int status = 0;
-
- if ( mountTable == 0
- && (mountTable = setmntent("/proc/mounts", "r")) == 0 ) {
- name_and_error("/etc/mtab");
- return 1;
+ // 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;
}
- while ( (m = getmntent(mountTable)) != 0 ) {
- entries[count].mnt_fsname = stralloc(m->mnt_fsname);
- count++;
- }
- endmntent(mountTable);
-
- while ( count > 0 ) {
- int result = umount(entries[--count].mnt_fsname) == 0;
- /* free(entries[count].mnt_fsname); */
- if ( result ) {
- if ( !noMtab )
- erase_mtab(entries[count].mnt_fsname);
- }
+ // 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 {
- status = 1;
- name_and_error(entries[count].mnt_fsname);
+ if (!zapit)
+ break;
+ argv++;
+ realpath(zapit, path);
+ for (m = mtl; m; m = m->next)
+ if (!strcmp(path, m->dir) || !strcmp(path, m->device))
+ break;
}
- }
- return status;
-}
+ // 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
-do_umount(const char * name, int noMtab)
-{
- if ( umount(name) == 0 ) {
- if ( !noMtab )
- erase_mtab(name);
- return 0;
- }
- return 1;
-}
+ // Let's ask the thing nicely to unmount.
+ curstat = umount(zapit);
-extern int
-umount_main(struct FileInfo * i, int argc, char * * argv)
-{
- int noMtab = 0;
-
- if ( argv[1][0] == '-' ) {
- switch ( argv[1][1] ) {
- case 'a':
- return umount_all(noMtab);
- case 'n':
- noMtab = 1;
- break;
- default:
- usage(umount_usage);
- return 1;
+ // 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)
+ if ((opt & OPT_ALL) || !strcmp(path, m->device))
+ break;
}
- if ( do_umount(argv[1],noMtab) != 0 ) {
- fprintf(stderr, "%s: %s.\n", argv[1], strerror(errno));
- return 1;
+
+ // 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);
}
- return 0;
+
+ return status;
}
projects / oweals / busybox.git / blobdiff