-#include "internal.h"
-#include <stdlib.h>
-#include <unistd.h>
-#include <errno.h>
-#include <string.h>
+/* vi: set sw=4 ts=4: */
+/*
+ * Mini umount implementation for busybox
+ *
+ * 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.
+ *
+ */
+
+#include <limits.h>
#include <stdio.h>
#include <mntent.h>
+#include <errno.h>
+#include <string.h>
+#include <stdlib.h>
#include <sys/mount.h>
+#include <getopt.h>
+#include "busybox.h"
-const char umount_usage[] = "umount {filesystem|directory}\n"
-"\tumount -a\n"
-"\n"
-"\tUnmount a filesystem.\n"
-"\t-a:\tUnmounts all mounted filesystems.\n";
+#define OPTION_STRING "flDnrvad"
+#define OPT_FORCE 1
+#define OPT_LAZY 2
+#define OPT_DONTFREELOOP 4
+#define OPT_NO_MTAB 8
+#define OPT_REMOUNT 16
+#define OPT_IGNORED 32 // -v is ignored
+#define OPT_ALL (ENABLE_FEATURE_UMOUNT_ALL ? 64 : 0)
-static char *
-stralloc(const char * string)
+int umount_main(int argc, char **argv)
{
- int length = strlen(string) + 1;
- char * n = malloc(length);
- memcpy(n, string, length);
- return n;
-}
+ int doForce;
+ char path[2*PATH_MAX];
+ struct mntent me;
+ FILE *fp;
+ int status = EXIT_SUCCESS;
+ unsigned long opt;
+ struct mtab_list {
+ char *dir;
+ char *device;
+ struct mtab_list *next;
+ } *mtl, *m;
-extern void
-erase_mtab(const char * name)
-{
- struct mntent entries[100];
- int count = 0;
- FILE * mountTable = setmntent("/etc/mtab", "r");
- struct mntent * m;
-
- if ( mountTable == 0
- && (mountTable = setmntent("/proc/mounts", "r")) == 0 ) {
- name_and_error("/etc/mtab");
- return;
+ /* Parse any options */
+
+ opt = bb_getopt_ulflags(argc, argv, OPTION_STRING);
+
+ argc -= optind;
+ argv += optind;
+
+ 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 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 (!(fp = setmntent(bb_path_mtab_file, "r"))) {
+ if (opt & OPT_ALL)
+ bb_error_msg_and_die("Cannot open %s", bb_path_mtab_file);
+ } else 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;
}
+ endmntent(fp);
- while ( (m = getmntent(mountTable)) != 0 ) {
- entries[count].mnt_fsname = stralloc(m->mnt_fsname);
- entries[count].mnt_dir = stralloc(m->mnt_dir);
- entries[count].mnt_type = stralloc(m->mnt_type);
- entries[count].mnt_opts = stralloc(m->mnt_opts);
- entries[count].mnt_freq = m->mnt_freq;
- entries[count].mnt_passno = m->mnt_passno;
- count++;
+ /* If we're not mounting all, we need at least one argument. */
+ if (!(opt & OPT_ALL)) {
+ m = 0;
+ if (!argc) bb_show_usage();
}
- endmntent(mountTable);
- if ( (mountTable = setmntent("/etc/mtab", "w")) ) {
- int i;
- for ( i = 0; i < count; i++ ) {
- int result = ( strcmp(entries[i].mnt_fsname, name) == 0
- || strcmp(entries[i].mnt_dir, name) == 0 );
-
- if ( result )
- continue;
- else
- addmntent(mountTable, &entries[i]);
+
+
+
+ // Loop through everything we're supposed to umount, and do so.
+ for (;;) {
+ int curstat;
+
+ // Do we already know what to umount this time through the loop?
+ if (m) safe_strncpy(path, m->dir, PATH_MAX);
+ // For umount -a, end of mtab means time to exit.
+ else if (opt & OPT_ALL) break;
+ // Get next command line argument (and look it up in mtab list)
+ else if (!argc--) break;
+ else {
+ realpath(*argv++, path);
+ for (m = mtl; m; m = m->next)
+ if (!strcmp(path, m->dir) || !strcmp(path, m->device))
+ break;
}
- endmntent(mountTable);
- }
- else if ( errno != EROFS )
- name_and_error("/etc/mtab");
-}
-static int
-umount_all(int noMtab)
-{
- struct mntent entries[100];
- int count = 0;
- FILE * mountTable = setmntent("/etc/mtab", "r");
- struct mntent * m;
- int status = 0;
-
- if ( mountTable == 0
- && (mountTable = setmntent("/proc/mounts", "r")) == 0 ) {
- name_and_error("/etc/mtab");
- return 1;
- }
+ // Let's ask the thing nicely to unmount.
+ curstat = umount(path);
- while ( (m = getmntent(mountTable)) != 0 ) {
- entries[count].mnt_fsname = stralloc(m->mnt_fsname);
- count++;
- }
- endmntent(mountTable);
-
- while ( count > 0 ) {
- int result = umount(entries[--count].mnt_fsname) == 0;
- /* free(entries[count].mnt_fsname); */
- if ( result ) {
- if ( !noMtab )
- erase_mtab(entries[count].mnt_fsname);
+ // 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);
}
- else {
- status = 1;
- name_and_error(entries[count].mnt_fsname);
+
+ // If still can't umount, maybe remount read-only?
+ if (curstat && (opt & OPT_REMOUNT) && 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);
}
- }
- return status;
-}
-extern int
-do_umount(const char * name, int noMtab)
-{
- if ( umount(name) == 0 ) {
- if ( !noMtab )
- erase_mtab(name);
- return 0;
- }
- return 1;
-}
+ /* De-allocate the loop device. This ioctl should be ignored on any
+ * non-loop block devices. */
+ if (ENABLE_FEATURE_MOUNT_LOOP && !(opt & OPT_DONTFREELOOP) && m)
+ del_loop(m->device);
-extern int
-umount_main(struct FileInfo * i, int argc, char * * argv)
-{
- int noMtab = 0;
-
- if ( argv[1][0] == '-' ) {
- switch ( argv[1][1] ) {
- case 'a':
- return umount_all(noMtab);
- case 'n':
- noMtab = 1;
- break;
- default:
- usage(umount_usage);
- return 1;
+ if (curstat) {
+ /* Yes, the ENABLE is redundant here, but the optimizer for ARM
+ * can't do simple constant propagation in local variables... */
+ if(ENABLE_FEATURE_MTAB_SUPPORT && !(opt & OPT_NO_MTAB) && m)
+ erase_mtab(m->dir);
+ status = EXIT_FAILURE;
+ bb_perror_msg("Couldn't umount %s", path);
}
+ // Find next matching mtab entry for -a or umount /dev
+ while (m && (m = m->next))
+ if ((opt & OPT_ALL) || !strcmp(path,m->device))
+ break;
}
- if ( do_umount(argv[1],noMtab) != 0 ) {
- fprintf(stderr, "%s: %s.\n", argv[1], strerror(errno));
- return 1;
+
+ // 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;
+ }
}
- return 0;
+
+ return status;
}
projects / oweals / busybox.git / blobdiff