1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
/* 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>
*
* Licensed under GPL version 2, see file LICENSE in this tarball for details.
*/
#include "busybox.h"
#include <mntent.h>
#include <getopt.h>
#define OPTION_STRING "flDnravd"
#define OPT_FORCE 1
#define OPT_LAZY 2
#define OPT_DONTFREELOOP 4
#define OPT_NO_MTAB 8
#define OPT_REMOUNT 16
#define OPT_ALL (ENABLE_FEATURE_UMOUNT_ALL ? 32 : 0)
int umount_main(int argc, char **argv)
{
int doForce;
char path[2*PATH_MAX];
struct mntent me;
FILE *fp;
int status = EXIT_SUCCESS;
unsigned opt;
struct mtab_list {
char *dir;
char *device;
struct mtab_list *next;
} *mtl, *m;
/* Parse any options */
opt = getopt32(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 = xstrdup(me.mnt_fsname);
m->dir = xstrdup(me.mnt_dir);
mtl = m;
}
endmntent(fp);
}
/* If we're not mounting all, we need at least one argument. */
if (!(opt & OPT_ALL)) {
m = 0;
if (!argc) bb_show_usage();
}
// Loop through everything we're supposed to umount, and do so.
for (;;) {
int curstat;
char *zapit = *argv;
// 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 {
argv++;
realpath(zapit, path);
for (m = mtl; m; m = m->next)
if (!strcmp(path, m->dir) || !strcmp(path, m->device))
break;
}
// If we couldn't find this sucker in /etc/mtab, punt by passing our
// command line argument straight to the umount syscall. Otherwise,
// umount the directory even if we were given the block device.
if (m) zapit = m->dir;
// Let's ask the thing nicely to unmount.
curstat = umount(zapit);
// Force the unmount, if necessary.
if (curstat && doForce) {
curstat = umount2(zapit, doForce);
if (curstat)
bb_error_msg_and_die("forced umount of %s failed!", zapit);
}
// If still can't umount, maybe remount read-only?
if (curstat && (opt & OPT_REMOUNT) && errno == EBUSY && m) {
curstat = mount(m->device, zapit, NULL, MS_REMOUNT|MS_RDONLY, NULL);
bb_error_msg(curstat ? "cannot remount %s read-only" :
"%s busy - remounted read-only", m->device);
}
if (curstat) {
status = EXIT_FAILURE;
bb_perror_msg("cannot umount %s", zapit);
} else {
/* 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);
if (ENABLE_FEATURE_MTAB_SUPPORT && !(opt & OPT_NO_MTAB) && m)
erase_mtab(m->dir);
}
// Find next matching mtab entry for -a or umount /dev
// Note this means that "umount /dev/blah" will unmount all instances
// of /dev/blah, not just the most recent.
while (m && (m = m->next))
if ((opt & OPT_ALL) || !strcmp(path,m->device))
break;
}
// 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 status;
}
|
