* Mini umount implementation for busybox
*
*
- * Copyright (C) 1999 by Lineo, inc.
+ * 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
*
*/
-#include "internal.h"
+#include <limits.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 char umount_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
-#ifdef BB_FEATURE_REMOUNT
- "\t-r:\tTry to remount devices as read-only if mount is busy\n"
-#endif
-;
+
+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;
+#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 */
-#define MIN(x,y) (x > y ? x : y)
-static int do_umount(const char *name, int useMtab)
+
+/* 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
+ */
+static 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);
+}
+
+static 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 */
+ cur->device = find_real_root_device_name(cur->device);
+ }
+#endif
+ return cur->device;
+ }
+ }
+ cur = cur->next;
+ }
+ return NULL;
+}
+
+static 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 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);
+}
+
+/* Don't bother to clean up, since exit() does that
+ * automagically, so we can save a few bytes */
+#ifdef BB_FEATURE_CLEAN_UP
+static 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 do_umount(const char *name)
{
int status;
char *blockDevice = mtab_getinfo(name, MTAB_GETDEVICE);
status = umount(name);
#if defined BB_FEATURE_MOUNT_LOOP
- if (blockDevice != NULL && !strncmp("/dev/loop", blockDevice, 9))
+ 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_REMOUNT
+#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) {
- fprintf(stderr, "umount: %s busy - remounted read-only\n",
- blockDevice);
- /* TODO: update mtab if BB_MTAB is defined */
+ error_msg("%s busy - remounted read-only", blockDevice);
} else {
- fprintf(stderr, "umount: Cannot remount %s read-only\n",
- blockDevice);
+ error_msg("Cannot remount %s read-only", blockDevice);
}
}
-#endif
if (status == 0) {
-#if defined BB_MTAB
+#if defined BB_FEATURE_MTAB_SUPPORT
if (useMtab == TRUE)
erase_mtab(name);
#endif
return (FALSE);
}
-static int umount_all(int useMtab)
+static int umount_all(void)
{
int status = TRUE;
char *mountpt;
void *iter;
for (mountpt = mtab_first(&iter); mountpt; mountpt = mtab_next(&iter)) {
- status = do_umount(mountpt, useMtab);
- if (status != 0) {
+ /* Never umount /proc on a umount -a */
+ if (strstr(mountpt, "proc")!= NULL)
+ continue;
+ if (!do_umount(mountpt)) {
/* Don't bother retrying the umount on busy devices */
if (errno == EBUSY) {
- perror(mountpt);
+ perror_msg("%s", mountpt);
+ status = FALSE;
continue;
}
- status = do_umount(mountpt, useMtab);
- if (status != 0) {
+ if (!do_umount(mountpt)) {
printf("Couldn't umount %s on %s: %s\n",
mountpt, mtab_getinfo(mountpt, MTAB_GETDEVICE),
strerror(errno));
+ status = FALSE;
}
}
}
extern int umount_main(int argc, char **argv)
{
+ char path[PATH_MAX];
+
if (argc < 2) {
- usage(umount_usage);
+ show_usage();
}
+#ifdef BB_FEATURE_CLEAN_UP
+ atexit(mtab_free);
+#endif
/* Parse any options */
while (--argc > 0 && **(++argv) == '-') {
case 'a':
umountAll = TRUE;
break;
-#ifdef BB_MTAB
+#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_REMOUNT
+#ifdef BB_FEATURE_MOUNT_FORCE
+ case 'f':
+ doForce = TRUE;
+ break;
+#endif
case 'r':
doRemount = TRUE;
break;
-#endif
+ case 'v':
+ break; /* ignore -v */
default:
- usage(umount_usage);
+ show_usage();
}
}
mtab_read();
if (umountAll == TRUE) {
- exit(umount_all(useMtab));
- }
- if (do_umount(*argv, useMtab) == 0)
- exit(TRUE);
- else {
- perror("umount");
- exit(FALSE);
+ if (umount_all() == TRUE)
+ return EXIT_SUCCESS;
+ else
+ return EXIT_FAILURE;
}
+ if (realpath(*argv, path) == NULL)
+ perror_msg_and_die("%s", path);
+ if (do_umount(path) == TRUE)
+ return EXIT_SUCCESS;
+ perror_msg_and_die("%s", *argv);
}
-
-
-/* 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
- */
-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) {
- fprintf(stderr, "Cannot open %s\n", mtab_file);
- return;
- }
- while ((e = getmntent(fp))) {
- entry = malloc(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_MTAB
- if (strcmp(cur->device, "/dev/root") == 0) {
- struct fstab *fstabItem;
-
- fstabItem = getfsfile("/");
- if (fstabItem != NULL)
- return fstabItem->fs_spec;
- }
-#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;
-}
-
-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;
- }
-}
projects / oweals / busybox.git / blobdiff