1 /* vi: set sw=4 ts=4: */
3 * Mini umount implementation for busybox
5 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
6 * Copyright (C) 2005 by Rob Landley <rob@landley.net>
8 * This program is licensed under the GNU General Public license (GPL)
9 * version 2 or later, see http://www.fsf.org/licensing/licenses/gpl.html
10 * or the file "LICENSE" in the busybox source tarball for the full text.
20 #include <sys/mount.h>
23 extern int umount_main(int argc, char **argv)
26 int freeLoop = ENABLE_FEATURE_MOUNT_LOOP;
27 int useMtab = ENABLE_FEATURE_MTAB_SUPPORT;
28 int umountAll = FALSE;
29 int doRemount = FALSE;
30 char path[2*PATH_MAX];
33 int status=EXIT_SUCCESS;
37 struct mtab_list *next;
40 if(argc < 2) bb_show_usage();
42 /* Parse any options */
43 while (--argc > 0 && **(++argv) == '-') {
45 if(**argv=='a') umountAll = TRUE;
46 else if(ENABLE_FEATURE_MOUNT_LOOP && **argv=='D') freeLoop = FALSE;
47 else if(ENABLE_FEATURE_MTAB_SUPPORT && **argv=='n') useMtab = FALSE;
48 else if(**argv=='f') doForce = 1; // MNT_FORCE
49 else if(**argv=='l') doForce = 2; // MNT_DETACH
50 else if(**argv=='r') doRemount = TRUE;
56 /* Get a list of mount points from mtab. We read them all in now mostly
57 * for umount -a (so we don't have to worry about the list changing while
58 * we iterate over it, or about getting stuck in a loop on the same failing
59 * entry. Notice that this also naturally reverses the list so that -a
60 * umounts the most recent entries first. */
63 if(!(fp = setmntent(bb_path_mtab_file, "r")))
64 bb_error_msg_and_die("Cannot open %s", bb_path_mtab_file);
65 while (getmntent_r(fp,&me,path,sizeof(path))) {
66 m=xmalloc(sizeof(struct mtab_list));
68 m->device=bb_xstrdup(me.mnt_fsname);
69 m->dir=bb_xstrdup(me.mnt_dir);
74 /* If we're umounting all, then m points to the start of the list and
75 * the argument list should be empty (which will match all). */
78 // Loop through everything we're supposed to umount, and do so.
82 // Do we alrady know what to umount this time through the loop?
83 if(m) safe_strncpy(path,m->dir,PATH_MAX);
84 // For umountAll, end of mtab means time to exit.
85 else if(umountAll) break;
86 // Get next command line argument (and look it up in mtab list)
87 else if(!argc--) break;
89 // Get next command line argument (and look it up in mtab list)
90 realpath(*argv++, path);
91 for(m = mtl; m; m = m->next)
92 if(!strcmp(path, m->dir) || !strcmp(path, m->device))
96 // Let's ask the thing nicely to unmount.
97 curstat = umount(path);
99 // Force the unmount, if necessary.
100 if(curstat && doForce) {
101 curstat = umount2(path, doForce);
103 bb_error_msg_and_die("forced umount of %s failed!", path);
106 // If still can't umount, maybe remount read-only?
107 if (curstat && doRemount && errno == EBUSY && m) {
108 curstat = mount(m->device, path, NULL, MS_REMOUNT|MS_RDONLY, NULL);
109 bb_error_msg(curstat ? "Cannot remount %s read-only" :
110 "%s busy - remounted read-only", m->device);
113 /* De-allcate the loop device. This ioctl should be ignored on any
114 * non-loop block devices. */
115 if(ENABLE_FEATURE_MOUNT_LOOP && freeLoop && m)
119 /* Yes, the ENABLE is redundant here, but the optimizer for ARM
120 * can't do simple constant propogation in local variables... */
121 if(ENABLE_FEATURE_MTAB_SUPPORT && useMtab && m) erase_mtab(m->dir);
122 status = EXIT_FAILURE;
123 bb_perror_msg("Couldn't umount %s\n", path);
125 // Find next matching mtab entry for -a or umount /dev
126 while(m && (m = m->next))
127 if(umountAll || !strcmp(path,m->device))
131 // Free mtab list if necessary
133 if(ENABLE_FEATURE_CLEAN_UP) {