+/* vi: set sw=4 ts=4: */
/*
* Mini umount implementation for busybox
*
- * Copyright (C) 1998 by Erik Andersen <andersee@debian.org>
+ *
+ * Copyright (C) 1999,2000,2001 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
*
*/
-#include "internal.h"
#include <stdio.h>
-#include <sys/mount.h>
#include <mntent.h>
-#include <fstab.h>
#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include "busybox.h"
+
+
+static const int MNT_FORCE = 1;
+static const int MS_MGC_VAL = 0xc0ed0000; /* Magic number indicatng "new" flags */
+static const int MS_REMOUNT = 32; /* Alter flags of a mounted FS. */
+static const int MS_RDONLY = 1; /* Mount read-only. */
+
+extern int mount (__const char *__special_file, __const char *__dir,
+ __const char *__fstype, unsigned long int __rwflag,
+ __const void *__data);
+extern int umount (__const char *__special_file);
+extern int umount2 (__const char *__special_file, int __flags);
+
+struct _mtab_entry_t {
+ char *device;
+ char *mountpt;
+ struct _mtab_entry_t *next;
+};
+
+static struct _mtab_entry_t *mtab_cache = NULL;
+
+
+
+#if defined BB_FEATURE_MOUNT_FORCE
+static int doForce = FALSE;
+#endif
+#if defined BB_FEATURE_MOUNT_LOOP
+static int freeLoop = TRUE;
+#endif
+#if defined BB_FEATURE_MTAB_SUPPORT
+static int useMtab = TRUE;
+#endif
+static int umountAll = FALSE;
+static int doRemount = FALSE;
+extern const char mtab_file[]; /* Defined in utility.c */
+
+
+
+/* These functions are here because the getmntent functions do not appear
+ * to be re-entrant, which leads to all sorts of problems when we try to
+ * use them recursively - randolph
+ *
+ * TODO: Perhaps switch to using Glibc's getmntent_r
+ * -Erik
+ */
+void mtab_read(void)
+{
+ struct _mtab_entry_t *entry = NULL;
+ struct mntent *e;
+ FILE *fp;
+
+ if (mtab_cache != NULL)
+ return;
+
+ if ((fp = setmntent(mtab_file, "r")) == NULL) {
+ error_msg("Cannot open %s", mtab_file);
+ return;
+ }
+ while ((e = getmntent(fp))) {
+ entry = xmalloc(sizeof(struct _mtab_entry_t));
+ entry->device = strdup(e->mnt_fsname);
+ entry->mountpt = strdup(e->mnt_dir);
+ entry->next = mtab_cache;
+ mtab_cache = entry;
+ }
+ endmntent(fp);
+}
+
+char *mtab_getinfo(const char *match, const char which)
+{
+ struct _mtab_entry_t *cur = mtab_cache;
+
+ while (cur) {
+ if (strcmp(cur->mountpt, match) == 0 ||
+ strcmp(cur->device, match) == 0) {
+ if (which == MTAB_GETMOUNTPT) {
+ return cur->mountpt;
+ } else {
+#if !defined BB_FEATURE_MTAB_SUPPORT
+ if (strcmp(cur->device, "/dev/root") == 0) {
+ /* Adjusts device to be the real root device,
+ * or leaves device alone if it can't find it */
+ find_real_root_device_name( cur->device);
+ return ( cur->device);
+ }
+#endif
+ return cur->device;
+ }
+ }
+ cur = cur->next;
+ }
+ return NULL;
+}
+
+char *mtab_first(void **iter)
+{
+ struct _mtab_entry_t *mtab_iter;
+
+ if (!iter)
+ return NULL;
+ mtab_iter = mtab_cache;
+ *iter = (void *) mtab_iter;
+ return mtab_next(iter);
+}
+
+char *mtab_next(void **iter)
+{
+ char *mp;
+
+ if (iter == NULL || *iter == NULL)
+ return NULL;
+ mp = ((struct _mtab_entry_t *) (*iter))->mountpt;
+ *iter = (void *) ((struct _mtab_entry_t *) (*iter))->next;
+ return mp;
+}
-static const char umount_usage[] =
-"Usage: umount filesystem\n"
-" or: umount directory\n"
-" or: umount -a"
-"to unmount all mounted file systems.\n";
+/* Don't bother to clean up, since exit() does that
+ * automagically, so we can save a few bytes */
+#ifdef BB_FEATURE_CLEAN_UP
+void mtab_free(void)
+{
+ struct _mtab_entry_t *this, *next;
+
+ this = mtab_cache;
+ while (this) {
+ next = this->next;
+ if (this->device)
+ free(this->device);
+ if (this->mountpt)
+ free(this->mountpt);
+ free(this);
+ this = next;
+ }
+}
+#endif
-static int
-umount_all()
+static int do_umount(const char *name)
{
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);
+ char *blockDevice = mtab_getinfo(name, MTAB_GETDEVICE);
+
+ if (blockDevice && strcmp(blockDevice, name) == 0)
+ name = mtab_getinfo(blockDevice, MTAB_GETMOUNTPT);
+
+ status = umount(name);
+
+#if defined BB_FEATURE_MOUNT_LOOP
+ if (freeLoop == TRUE && blockDevice != NULL && !strncmp("/dev/loop", blockDevice, 9))
+ /* this was a loop device, delete it */
+ del_loop(blockDevice);
+#endif
+#if defined BB_FEATURE_MOUNT_FORCE
+ if (status != 0 && doForce == TRUE) {
+ status = umount2(blockDevice, MNT_FORCE);
+ if (status != 0) {
+ error_msg_and_die("forced umount of %s failed!", blockDevice);
+ }
+ }
+#endif
+ if (status != 0 && doRemount == TRUE && errno == EBUSY) {
+ status = mount(blockDevice, name, NULL,
+ MS_MGC_VAL | MS_REMOUNT | MS_RDONLY, NULL);
+ if (status == 0) {
+ error_msg("%s busy - remounted read-only", blockDevice);
+ } else {
+ error_msg("Cannot remount %s read-only", blockDevice);
+ }
+ }
+ if (status == 0) {
+#if defined BB_FEATURE_MTAB_SUPPORT
+ if (useMtab == TRUE)
+ erase_mtab(name);
+#endif
+ return (TRUE);
+ }
+ return (FALSE);
+}
+
+static int umount_all(void)
+{
+ int status = TRUE;
+ char *mountpt;
+ void *iter;
+
+ for (mountpt = mtab_first(&iter); mountpt; mountpt = mtab_next(&iter)) {
+ /* Never umount /proc on a umount -a */
+ if (strstr(mountpt, "proc")!= NULL)
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));
- }
+ if (!do_umount(mountpt)) {
+ /* Don't bother retrying the umount on busy devices */
+ if (errno == EBUSY) {
+ perror_msg("%s", mountpt);
+ status = FALSE;
+ continue;
+ }
+ if (!do_umount(mountpt)) {
+ printf("Couldn't umount %s on %s: %s\n",
+ mountpt, mtab_getinfo(mountpt, MTAB_GETDEVICE),
+ strerror(errno));
+ status = FALSE;
+ }
}
- }
- endmntent (mountTable);
- }
- return( TRUE);
+ }
+ return (status);
}
-extern int
-umount_main(int argc, char * * argv)
+extern int umount_main(int argc, char **argv)
{
+ if (argc < 2) {
+ show_usage();
+ }
+#ifdef BB_FEATURE_CLEAN_UP
+ atexit(mtab_free);
+#endif
+
+ /* Parse any options */
+ while (--argc > 0 && **(++argv) == '-') {
+ while (*++(*argv))
+ switch (**argv) {
+ case 'a':
+ umountAll = TRUE;
+ break;
+#if defined BB_FEATURE_MOUNT_LOOP
+ case 'l':
+ freeLoop = FALSE;
+ break;
+#endif
+#ifdef BB_FEATURE_MTAB_SUPPORT
+ case 'n':
+ useMtab = FALSE;
+ break;
+#endif
+#ifdef BB_FEATURE_MOUNT_FORCE
+ case 'f':
+ doForce = TRUE;
+ break;
+#endif
+ case 'r':
+ doRemount = TRUE;
+ break;
+ case 'v':
+ break; /* ignore -v */
+ default:
+ show_usage();
+ }
+ }
- 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);
+ mtab_read();
+ if (umountAll == TRUE) {
+ if (umount_all() == TRUE)
+ return EXIT_SUCCESS;
+ else
+ return EXIT_FAILURE;
}
- }
- if ( umount(*argv) == 0 )
- exit (TRUE);
- else {
- perror("umount");
- exit( FALSE);
- }
+ if (do_umount(*argv) == TRUE)
+ return EXIT_SUCCESS;
+ perror_msg_and_die("%s", *argv);
}
projects / oweals / busybox.git / blobdiff