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 "flDnrva"
27 #define OPT_DONTFREELOOP 4
29 #define OPT_REMOUNT 16
30 #define OPT_IGNORED 32 // -v is ignored
31 #define OPT_ALL (ENABLE_FEATURE_UMOUNT_ALL ? 64 : 0)
33 int umount_main(int argc, char **argv)
36 char path[2*PATH_MAX];
39 int status=EXIT_SUCCESS;
44 struct mtab_list *next;
47 /* Parse any options */
49 opt = bb_getopt_ulflags (argc, argv, OPTION_STRING);
54 doForce = MAX((opt & OPT_FORCE), (opt & OPT_LAZY));
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. */
65 /* If we're umounting all, then m points to the start of the list and
66 * the argument list should be empty (which will match all). */
68 if(!(fp = setmntent(bb_path_mtab_file, "r")))
69 bb_error_msg_and_die("Cannot open %s", bb_path_mtab_file);
70 while (getmntent_r(fp,&me,path,sizeof(path))) {
71 m=xmalloc(sizeof(struct mtab_list));
73 m->device=bb_xstrdup(me.mnt_fsname);
74 m->dir=bb_xstrdup(me.mnt_dir);
79 /* If we're not mounting all, we need at least one argument. */
80 } else if(argc <= 0) bb_show_usage();
82 // Loop through everything we're supposed to umount, and do so.
86 // Do we already know what to umount this time through the loop?
87 if(m) safe_strncpy(path,m->dir,PATH_MAX);
88 // For umount -a, end of mtab means time to exit.
89 else if(opt & OPT_ALL) break;
90 // Get next command line argument (and look it up in mtab list)
91 else if(!argc--) break;
93 // Get next command line argument (and look it up in mtab list)
94 realpath(*argv++, path);
95 if (ENABLE_FEATURE_MTAB_SUPPORT)
96 for(m = mtl; m; m = m->next)
97 if(!strcmp(path, m->dir) || !strcmp(path, m->device))
101 // Let's ask the thing nicely to unmount.
102 curstat = umount(path);
104 // Force the unmount, if necessary.
105 if(curstat && doForce) {
106 curstat = umount2(path, doForce);
108 bb_error_msg_and_die("forced umount of %s failed!", path);
111 // If still can't umount, maybe remount read-only?
112 if (curstat && (opt & OPT_REMOUNT) && errno == EBUSY && m) {
113 curstat = mount(m->device, path, NULL, MS_REMOUNT|MS_RDONLY, NULL);
114 bb_error_msg(curstat ? "Cannot remount %s read-only" :
115 "%s busy - remounted read-only", m->device);
118 /* De-allocate the loop device. This ioctl should be ignored on any
119 * non-loop block devices. */
120 if(ENABLE_FEATURE_MOUNT_LOOP && !(opt & OPT_DONTFREELOOP) && m)
124 /* Yes, the ENABLE is redundant here, but the optimizer for ARM
125 * can't do simple constant propagation in local variables... */
126 if(ENABLE_FEATURE_MTAB_SUPPORT && !(opt & OPT_NO_MTAB) && m)
128 status = EXIT_FAILURE;
129 bb_perror_msg("Couldn't umount %s", path);
131 // Find next matching mtab entry for -a or umount /dev
132 while(m && (m = m->next))
133 if((opt & OPT_ALL) || !strcmp(path,m->device))
137 // Free mtab list if necessary
139 if(ENABLE_FEATURE_CLEAN_UP) {