1 files changed, 298 insertions, 0 deletions

diff --git a/busybox/util-linux/umount.c b/busybox/util-linux/umount.c
new file mode 100644
index 000000000..21c2e6e4d
--- /dev/null
+++ b/busybox/util-linux/umount.c
@@ -0,0 +1,298 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Mini umount implementation for busybox
+ *
+ * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.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
+ *
+ */
+
+#include <limits.h>
+#include <stdio.h>
+#include <mntent.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
+#include "busybox.h"
+
+/* Teach libc5 about realpath -- it includes it but the
+ * prototype is missing... */
+#if (__GLIBC__ <= 2) && (__GLIBC_MINOR__ < 1)
+extern char *realpath(const char *path, char *resolved_path);
+#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;
+        char *mountpt;
+        struct _mtab_entry_t *next;
+};
+
+static struct _mtab_entry_t *mtab_cache = NULL;
+
+
+
+#if defined CONFIG_FEATURE_MOUNT_FORCE
+static int doForce = FALSE;
+#endif
+#if defined CONFIG_FEATURE_MOUNT_LOOP
+static int freeLoop = TRUE;
+#endif
+#if defined CONFIG_FEATURE_MTAB_SUPPORT
+static int useMtab = TRUE;
+#endif
+static int umountAll = FALSE;
+static int doRemount = FALSE;
+
+
+
+/* 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(bb_path_mtab_file, "r")) == NULL) {
+                bb_error_msg("Cannot open %s", bb_path_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 CONFIG_FEATURE_MTAB_SUPPORT
+                                if (strcmp(cur->device, "rootfs") == 0) {
+                                        continue;
+                                } else 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();
+                                }
+#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 CONFIG_FEATURE_CLEAN_UP
+static void mtab_free(void)
+{
+        struct _mtab_entry_t *this, *next;
+
+        this = mtab_cache;
+        while (this) {
+                next = this->next;
+                free(this->device);
+                free(this->mountpt);
+                free(this);
+                this = next;
+        }
+}
+#endif
+
+static int do_umount(const char *name)
+{
+        int status;
+        char *blockDevice = mtab_getinfo(name, MTAB_GETDEVICE);
+
+        if (blockDevice && strcmp(blockDevice, name) == 0)
+                name = mtab_getinfo(blockDevice, MTAB_GETMOUNTPT);
+
+        status = umount(name);
+
+#if defined CONFIG_FEATURE_MOUNT_LOOP
+        if (freeLoop && blockDevice != NULL && !strncmp("/dev/loop", blockDevice, 9))
+                /* this was a loop device, delete it */
+                del_loop(blockDevice);
+#endif
+#if defined CONFIG_FEATURE_MOUNT_FORCE
+        if (status != 0 && doForce) {
+                status = umount2(blockDevice, MNT_FORCE);
+                if (status != 0) {
+                        bb_error_msg_and_die("forced umount of %s failed!", blockDevice);
+                }
+        }
+#endif
+        if (status != 0 && doRemount && errno == EBUSY) {
+                status = mount(blockDevice, name, NULL,
+                                           MS_MGC_VAL | MS_REMOUNT | MS_RDONLY, NULL);
+                if (status == 0) {
+                        bb_error_msg("%s busy - remounted read-only", blockDevice);
+                } else {
+                        bb_error_msg("Cannot remount %s read-only", blockDevice);
+                }
+        }
+        if (status == 0) {
+#if defined CONFIG_FEATURE_MTAB_SUPPORT
+                if (useMtab)
+                        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;
+                if (!do_umount(mountpt)) {
+                        /* Don't bother retrying the umount on busy devices */
+                        if (errno == EBUSY) {
+                                bb_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;
+                        }
+                }
+        }
+        return (status);
+}
+
+extern int umount_main(int argc, char **argv)
+{
+        char path[PATH_MAX], result = 0;
+
+        if (argc < 2) {
+                bb_show_usage();
+        }
+#ifdef CONFIG_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 CONFIG_FEATURE_MOUNT_LOOP
+                        case 'l':
+                                freeLoop = FALSE;
+                                break;
+#endif
+#ifdef CONFIG_FEATURE_MTAB_SUPPORT
+                        case 'n':
+                                useMtab = FALSE;
+                                break;
+#endif
+#ifdef CONFIG_FEATURE_MOUNT_FORCE
+                        case 'f':
+                                doForce = TRUE;
+                                break;
+#endif
+                        case 'r':
+                                doRemount = TRUE;
+                                break;
+                        case 'v':
+                                break; /* ignore -v */
+                        default:
+                                bb_show_usage();
+                        }
+        }
+
+        mtab_read();
+        if (umountAll) {
+                if (umount_all())
+                        return EXIT_SUCCESS;
+                else
+                        return EXIT_FAILURE;
+        }
+
+        do {
+                if (realpath(*argv, path) != NULL)
+                        if (do_umount(path))
+                                continue;
+                bb_perror_msg("%s", path);
+                result++;
+        } while (--argc > 0 && ++argv);
+        return result;
+}