*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
* Copyright (C) 2005 by Rob Landley <rob@landley.net>
- *
- * This program is licensed under the GNU General Public license (GPL)
- * version 2 or later, see http://www.fsf.org/licensing/licenses/gpl.html
- * or the file "LICENSE" in the busybox source tarball for the full text.
*
+ * Licensed under GPLv2, see file LICENSE in this source tree.
*/
-#include <limits.h>
-#include <stdio.h>
+//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 <errno.h>
-#include <string.h>
-#include <stdlib.h>
#include <sys/mount.h>
-#include "busybox.h"
+#include "libbb.h"
-extern int umount_main(int argc, char **argv)
+#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 doForce = 0;
- int freeLoop = ENABLE_FEATURE_MOUNT_LOOP;
- int useMtab = ENABLE_FEATURE_MTAB_SUPPORT;
- int umountAll = FALSE;
- int doRemount = FALSE;
- char path[2*PATH_MAX];
+ struct mntent* ment = getmntent(stream);
+ return memcpy(result, ment, sizeof(*ment));
+}
+#endif
+
+/* 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 doForce;
struct mntent me;
FILE *fp;
- int status=EXIT_SUCCESS;
+ char *fstype = NULL;
+ int status = EXIT_SUCCESS;
+ unsigned opt;
struct mtab_list {
char *dir;
char *device;
- struct mtab_list *next;
+ struct mtab_list *next;
} *mtl, *m;
- if(argc < 2) bb_show_usage();
-
- /* Parse any options */
- while (--argc > 0 && **(++argv) == '-') {
- while (*++(*argv)) {
- if(**argv=='a') umountAll = TRUE;
- else if(ENABLE_FEATURE_MOUNT_LOOP && **argv=='D') freeLoop = FALSE;
- else if(ENABLE_FEATURE_MTAB_SUPPORT && **argv=='n') useMtab = FALSE;
- else if(**argv=='f') doForce = 1; // MNT_FORCE
- else if(**argv=='l') doForce = 2; // MNT_DETACH
- else if(**argv=='r') doRemount = TRUE;
- else if(**argv=='v');
- else bb_show_usage();
- }
- }
+ 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=0;
- if(!(fp = setmntent(bb_path_mtab_file, "r")))
- bb_error_msg_and_die("Cannot open %s", bb_path_mtab_file);
- while (getmntent_r(fp,&me,path,sizeof(path))) {
- m=xmalloc(sizeof(struct mtab_list));
- m->next=mtl;
- m->device=bb_xstrdup(me.mnt_fsname);
- m->dir=bb_xstrdup(me.mnt_dir);
- mtl=m;
+ 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;
+ }
+ endmntent(fp);
}
- endmntent(fp);
- /* 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). */
- if(!umountAll) m=0;
+ // 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(;;) {
+ for (;;) {
int curstat;
-
- // Do we alrady know what to umount this time through the loop?
- if(m) safe_strncpy(path,m->dir,PATH_MAX);
- // For umountAll, end of mtab means time to exit.
- else if(umountAll) break;
- // Get next command line argument (and look it up in mtab list)
- else if(!argc--) break;
+ 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 {
- // Get next command line argument (and look it up in mtab list)
- realpath(*argv++, path);
- for(m = mtl; m; m = m->next)
- if(!strcmp(path, m->dir) || !strcmp(path, m->device))
- break;
+ 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;
+ }
}
+ // 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(path);
+ curstat = umount(zapit);
// Force the unmount, if necessary.
- if(curstat && doForce) {
- curstat = umount2(path, doForce);
- if(curstat)
- bb_error_msg_and_die("forced umount of %s failed!", path);
- }
+ if (curstat && doForce)
+ curstat = umount2(zapit, doForce);
- // If still can't umount, maybe remount read-only?
- if (curstat && doRemount && errno == EBUSY && m) {
- curstat = mount(m->device, path, NULL, MS_REMOUNT|MS_RDONLY, NULL);
- bb_error_msg(curstat ? "Cannot remount %s read-only" :
- "%s busy - remounted read-only", m->device);
+ // 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);
}
- /* De-allcate the loop device. This ioctl should be ignored on any
- * non-loop block devices. */
- if(ENABLE_FEATURE_MOUNT_LOOP && freeLoop && m)
- del_loop(m->device);
-
- if(curstat) {
- /* Yes, the ENABLE is redundant here, but the optimizer for ARM
- * can't do simple constant propogation in local variables... */
- if(ENABLE_FEATURE_MTAB_SUPPORT && useMtab && m) erase_mtab(m->dir);
- status = EXIT_FAILURE;
- bb_perror_msg("Couldn't umount %s\n", path);
- }
// Find next matching mtab entry for -a or umount /dev
- while(m && (m = m->next))
- if(umountAll || !strcmp(path,m->device))
- break;
+ // 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);
}
// Free mtab list if necessary
-
- if(ENABLE_FEATURE_CLEAN_UP) {
- while(mtl) {
- m=mtl->next;
+ if (ENABLE_FEATURE_CLEAN_UP) {
+ while (mtl) {
+ m = mtl->next;
free(mtl->device);
free(mtl->dir);
free(mtl);
- mtl=m;
+ mtl = m;
}
}
projects / oweals / busybox.git / blobdiff