1 files changed, 107 insertions, 263 deletions

diff --git a/util-linux/umount.c b/util-linux/umount.c
index 21c2e6e..6de71b4 100644
--- a/util-linux/umount.c
+++ b/util-linux/umount.c
@@ -3,20 +3,11 @@
  * 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
+ * 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.
  *
  */
 
@@ -26,273 +17,126 @@
 #include <errno.h>
 #include <string.h>
 #include <stdlib.h>
+#include <sys/mount.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)
+extern int umount_main(int argc, char **argv)
 {
-	struct _mtab_entry_t *entry = NULL;
-	struct mntent *e;
+	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 me;
 	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;
-			}
+	int status=EXIT_SUCCESS;
+	struct mtab_list {
+		char *dir;
+		char *device;
+	   	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();
 		}
-		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;
+	/* 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;
 	}
-}
-#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);
+	endmntent(fp);
 
-#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 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;
+
+	// Loop through everything we're supposed to umount, and do so.
+	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;
+		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 (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;
+		// Let's ask the thing nicely to unmount.
+		curstat = umount(path);
 
-	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;
-			}
+		// 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);
 		}
-	}
-	return (status);
-}
 
-extern int umount_main(int argc, char **argv)
-{
-	char path[PATH_MAX], result = 0;
+		// 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 (argc < 2) {
-		bb_show_usage();
-	}
-#ifdef CONFIG_FEATURE_CLEAN_UP
-	atexit(mtab_free);
-#endif
+		/* 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);
 
-	/* 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();
-			}
+		if(curstat) {
+			if(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;
 	}
 
-	mtab_read();
-	if (umountAll) {
-		if (umount_all())
-			return EXIT_SUCCESS;
-		else
-			return EXIT_FAILURE;
+	// 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;
+		}
 	}
 
-	do {
-		if (realpath(*argv, path) != NULL)
-			if (do_umount(path))
-				continue;
-		bb_perror_msg("%s", path);
-		result++;
-	} while (--argc > 0 && ++argv);
-	return result;
+	return status;
 }