blob: e55002bf0011fb429b8daa82dd8fa7259a820d7f [file] [log] [blame]
Erik Andersene49d5ec2000-02-08 19:58:47 +00001/* vi: set sw=4 ts=4: */
Eric Andersenf811e071999-10-09 00:25:00 +00002/*
3 * Mini umount implementation for busybox
4 *
Eric Andersenc7bda1c2004-03-15 08:29:22 +00005 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
Rob Landley6a6798b2005-08-10 20:35:54 +00006 * Copyright (C) 2005 by Rob Landley <rob@landley.net>
7 *
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.
Eric Andersenf811e071999-10-09 00:25:00 +000011 *
12 */
13
Matt Kraaiadcbc122001-05-02 21:24:51 +000014#include <limits.h>
Eric Andersencc8ed391999-10-05 16:24:54 +000015#include <stdio.h>
Eric Andersenf811e071999-10-09 00:25:00 +000016#include <mntent.h>
Eric Andersenf811e071999-10-09 00:25:00 +000017#include <errno.h>
Eric Andersened3ef502001-01-27 08:24:39 +000018#include <string.h>
19#include <stdlib.h>
Rob Landley6a6798b2005-08-10 20:35:54 +000020#include <sys/mount.h>
Rob Landley16722552005-09-24 22:41:08 +000021#include <getopt.h>
Eric Andersencbe31da2001-02-20 06:14:08 +000022#include "busybox.h"
Eric Andersene1e23ee2000-06-19 18:38:51 +000023
Rob Landley16722552005-09-24 22:41:08 +000024#define OPTION_STRING "flaDnrv"
25#define OPT_FORCE 1
26#define OPT_LAZY 2
27#define OPT_ALL 4
28#define OPT_DONTFREELOOP 8
29#define OPT_NO_MTAB 16
30#define OPT_REMOUNT 32
31/* -v is ignored */
32
33
Erik Andersene132f4b2000-02-09 04:16:43 +000034extern int umount_main(int argc, char **argv)
35{
Rob Landley16722552005-09-24 22:41:08 +000036 int doForce;
Rob Landley6a6798b2005-08-10 20:35:54 +000037 char path[2*PATH_MAX];
38 struct mntent me;
39 FILE *fp;
40 int status=EXIT_SUCCESS;
Rob Landley16722552005-09-24 22:41:08 +000041 unsigned long opt;
Rob Landley6a6798b2005-08-10 20:35:54 +000042 struct mtab_list {
43 char *dir;
44 char *device;
45 struct mtab_list *next;
46 } *mtl, *m;
Matt Kraaiadcbc122001-05-02 21:24:51 +000047
Rob Landley6a6798b2005-08-10 20:35:54 +000048 if(argc < 2) bb_show_usage();
49
Erik Andersene132f4b2000-02-09 04:16:43 +000050 /* Parse any options */
Rob Landley16722552005-09-24 22:41:08 +000051
52 opt = bb_getopt_ulflags (argc, argv, "flaDnrv");
53
54 argc -= optind;
55 argv += optind;
Erik Andersene132f4b2000-02-09 04:16:43 +000056
Rob Landley16722552005-09-24 22:41:08 +000057 doForce = MAX((opt & OPT_FORCE), (opt & OPT_LAZY));
58
Rob Landley6a6798b2005-08-10 20:35:54 +000059 /* 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. */
64
65 m=mtl=0;
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));
70 m->next=mtl;
71 m->device=bb_xstrdup(me.mnt_fsname);
72 m->dir=bb_xstrdup(me.mnt_dir);
73 mtl=m;
74 }
75 endmntent(fp);
76
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). */
Rob Landley16722552005-09-24 22:41:08 +000079 if(!(opt & OPT_ALL)) m=0;
Rob Landley6a6798b2005-08-10 20:35:54 +000080
81 // Loop through everything we're supposed to umount, and do so.
82 for(;;) {
83 int curstat;
84
Rob Landley16722552005-09-24 22:41:08 +000085 // Do we already know what to umount this time through the loop?
Rob Landley6a6798b2005-08-10 20:35:54 +000086 if(m) safe_strncpy(path,m->dir,PATH_MAX);
Rob Landley16722552005-09-24 22:41:08 +000087 // For umount -a, end of mtab means time to exit.
88 else if(opt & OPT_ALL) break;
Rob Landley6a6798b2005-08-10 20:35:54 +000089 // Get next command line argument (and look it up in mtab list)
90 else if(!argc--) break;
91 else {
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))
96 break;
97 }
98
99 // Let's ask the thing nicely to unmount.
100 curstat = umount(path);
101
102 // Force the unmount, if necessary.
103 if(curstat && doForce) {
104 curstat = umount2(path, doForce);
105 if(curstat)
106 bb_error_msg_and_die("forced umount of %s failed!", path);
107 }
108
109 // If still can't umount, maybe remount read-only?
Rob Landley16722552005-09-24 22:41:08 +0000110 if (curstat && (opt & OPT_REMOUNT) && errno == EBUSY && m) {
Rob Landley6a6798b2005-08-10 20:35:54 +0000111 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);
114 }
115
Rob Landley16722552005-09-24 22:41:08 +0000116 /* De-allocate the loop device. This ioctl should be ignored on any
Rob Landley6a6798b2005-08-10 20:35:54 +0000117 * non-loop block devices. */
Rob Landley16722552005-09-24 22:41:08 +0000118 if(ENABLE_FEATURE_MOUNT_LOOP && !(opt & OPT_DONTFREELOOP) && m)
Rob Landley6a6798b2005-08-10 20:35:54 +0000119 del_loop(m->device);
120
121 if(curstat) {
Rob Landleyf4c684a2005-08-23 20:03:17 +0000122 /* Yes, the ENABLE is redundant here, but the optimizer for ARM
Rob Landley16722552005-09-24 22:41:08 +0000123 * can't do simple constant propagation in local variables... */
124 if(ENABLE_FEATURE_MTAB_SUPPORT && !(opt & OPT_NO_MTAB) && m)
125 erase_mtab(m->dir);
Rob Landley6a6798b2005-08-10 20:35:54 +0000126 status = EXIT_FAILURE;
127 bb_perror_msg("Couldn't umount %s\n", path);
128 }
129 // Find next matching mtab entry for -a or umount /dev
130 while(m && (m = m->next))
Rob Landley16722552005-09-24 22:41:08 +0000131 if((opt & OPT_ALL) || !strcmp(path,m->device))
Rob Landley6a6798b2005-08-10 20:35:54 +0000132 break;
Erik Andersene132f4b2000-02-09 04:16:43 +0000133 }
Erik Andersene132f4b2000-02-09 04:16:43 +0000134
Rob Landley6a6798b2005-08-10 20:35:54 +0000135 // Free mtab list if necessary
136
137 if(ENABLE_FEATURE_CLEAN_UP) {
138 while(mtl) {
139 m=mtl->next;
140 free(mtl->device);
141 free(mtl->dir);
142 free(mtl);
143 mtl=m;
144 }
145 }
146
147 return status;
Glenn L McGrath15a4f1e2004-02-22 11:35:13 +0000148}