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>
24 #define OPTION_STRING "flaDnrv"
28 #define OPT_DONTFREELOOP 8
29 #define OPT_NO_MTAB 16
30 #define OPT_REMOUNT 32
34 extern int umount_main(int argc, char **argv)
37 char path[2*PATH_MAX];
40 int status=EXIT_SUCCESS;
45 struct mtab_list *next;
48 if(argc < 2) bb_show_usage();
50 /* Parse any options */
52 opt = bb_getopt_ulflags (argc, argv, "flaDnrv");
57 doForce = MAX((opt & OPT_FORCE), (opt & OPT_LAZY));
59 /* Get a list of mount points from mtab. We read them all in now mostly
60 * for umount -a (so we don't have to worry about the list changing while
61 * we iterate over it, or about getting stuck in a loop on the same failing
62 * entry. Notice that this also naturally reverses the list so that -a
63 * umounts the most recent entries first. */
66 if(!(fp = setmntent(bb_path_mtab_file, "r")))
67 bb_error_msg_and_die("Cannot open %s", bb_path_mtab_file);
68 while (getmntent_r(fp,&me,path,sizeof(path))) {
69 m=xmalloc(sizeof(struct mtab_list));
71 m->device=bb_xstrdup(me.mnt_fsname);
72 m->dir=bb_xstrdup(me.mnt_dir);
77 /* If we're umounting all, then m points to the start of the list and
78 * the argument list should be empty (which will match all). */
79 if(!(opt & OPT_ALL)) m=0;
81 // Loop through everything we're supposed to umount, and do so.
85 // Do we already know what to umount this time through the loop?
86 if(m) safe_strncpy(path,m->dir,PATH_MAX);
87 // For umount -a, end of mtab means time to exit.
88 else if(opt & OPT_ALL) break;
89 // Get next command line argument (and look it up in mtab list)
90 else if(!argc--) break;
92 // Get next command line argument (and look it up in mtab list)
93 realpath(*argv++, path);
94 for(m = mtl; m; m = m->next)
95 if(!strcmp(path, m->dir) || !strcmp(path, m->device))
99 // Let's ask the thing nicely to unmount.
100 curstat = umount(path);
102 // Force the unmount, if necessary.
103 if(curstat && doForce) {
104 curstat = umount2(path, doForce);
106 bb_error_msg_and_die("forced umount of %s failed!", path);
109 // If still can't umount, maybe remount read-only?
110 if (curstat && (opt & OPT_REMOUNT) && errno == EBUSY && m) {
111 curstat = mount(m->device, path, NULL, MS_REMOUNT|MS_RDONLY, NULL);
112 bb_error_msg(curstat ? "Cannot remount %s read-only" :
113 "%s busy - remounted read-only", m->device);
116 /* De-allocate the loop device. This ioctl should be ignored on any
117 * non-loop block devices. */
118 if(ENABLE_FEATURE_MOUNT_LOOP && !(opt & OPT_DONTFREELOOP) && m)
122 /* Yes, the ENABLE is redundant here, but the optimizer for ARM
123 * can't do simple constant propagation in local variables... */
124 if(ENABLE_FEATURE_MTAB_SUPPORT && !(opt & OPT_NO_MTAB) && m)
126 status = EXIT_FAILURE;
127 bb_perror_msg("Couldn't umount %s\n", path);
129 // Find next matching mtab entry for -a or umount /dev
130 while(m && (m = m->next))
131 if((opt & OPT_ALL) || !strcmp(path,m->device))
135 // Free mtab list if necessary
137 if(ENABLE_FEATURE_CLEAN_UP) {