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
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
|
/* umount.c - Unmount a mount point.
*
* Copyright 2012 Rob Landley <rob@landley.net>
*
* See http://refspecs.linuxfoundation.org/LSB_4.1.0/LSB-Core-generic/LSB-Core-generic/umount.html
*
* Note: -n (/etc/mtab) is obsolete, /proc/mounts replaced it. Neither chroot
* nor per-process mount namespaces can work sanely with mtab. The kernel
* tracks mount points now, a userspace application can't do so anymore.
USE_UMOUNT(NEWTOY(umount, "ndDflrat*v[!na]", TOYFLAG_BIN|TOYFLAG_STAYROOT))
config UMOUNT
bool "umount"
default y
help
usage: umount [-a [-t TYPE[,TYPE...]]] [-vrfD] [DIR...]
Unmount the listed filesystems.
-a Unmount all mounts in /proc/mounts instead of command line list
-D Don't free loopback device(s).
-f Force unmount.
-l Lazy unmount (detach from filesystem now, close when last user does).
-n Don't use /proc/mounts
-r Remount read only if unmounting fails.
-t Restrict "all" to mounts of TYPE (or use "noTYPE" to skip)
-v Verbose
*/
#define FOR_umount
#include "toys.h"
GLOBALS(
struct arg_list *t;
char *types;
)
// todo
// borrow df code to identify filesystem?
// umount -a from fstab
// umount when getpid() not 0, according to fstab
// lookup mount: losetup -d, bind, file, block
// TODO
// loopback delete
// fstab -o user
// Realloc *old with oldstring,newstring
void comma_collate(char **old, char *new)
{
char *temp, *atold = *old;
// Only add a comma if old string didn't end with one
if (atold && *atold) {
char *comma = ",";
if (atold[strlen(atold)-1] == ',') comma = "";
temp = xmprintf("%s%s%s", atold, comma, new);
} else temp = xstrdup(new);
free (atold);
*old = temp;
}
// iterate through strings in a comma separated list.
// returns start of next entry or NULL if none
// sets *len to length of entry (not including comma)
// advances *list to start of next entry
char *comma_iterate(char **list, int *len)
{
char *start = *list, *end;
if (!*list) return 0;
if (!(end = strchr(*list, ','))) {
*len = strlen(*list);
*list = 0;
} else *list += (*len = end-start)+1;
return start;
}
static void do_umount(char *dir, char *dev, int flags)
{
if (!umount2(dir, flags)) {
if (toys.optflags & FLAG_v) xprintf("%s unmounted\n", dir);
// Attempt to disassociate loopback device. This ioctl should be ignored
// for anything else, because lanana allocated ioctl range 'L' to loopback
if (dev && !(toys.optflags & FLAG_D)) {
int lfd = open(dev, O_RDONLY);
if (lfd != -1) {
// This is LOOP_CLR_FD, fetching it from headers is awkward
if (!ioctl(lfd, 0x4C01) && (toys.optflags & FLAG_v))
xprintf("%s cleared\n", dev);
close(lfd);
}
}
return;
}
if (toys.optflags & FLAG_r) {
if (!mount("", dir, "", MS_REMOUNT|MS_RDONLY, "")) {
if (toys.optflags & FLAG_v) xprintf("%s remounted ro\n", dir);
return;
}
}
perror_msg("%s", dir);
}
void umount_main(void)
{
char **optargs, *pm = "/proc/mounts";
struct mtab_list *mlsave = 0, *mlrev = 0, *ml;
int flags=0;
if (!toys.optc && !(toys.optflags & FLAG_a))
error_exit("Need 1 arg or -a");
if (toys.optflags & FLAG_f) flags |= MNT_FORCE;
if (toys.optflags & FLAG_l) flags |= MNT_DETACH;
// Load /proc/mounts and get a reversed list (newest first)
// We use the list both for -a, and to umount /dev/name or do losetup -d
if (!(toys.optflags & FLAG_n) && !access(pm, R_OK))
mlrev = dlist_terminate(mlsave = xgetmountlist(pm));
// Unmount all: loop through mounted filesystems, skip -t, unmount the rest
if (toys.optflags & FLAG_a) {
char *typestr = 0;
struct arg_list *tal;
for (tal = TT.t; tal; tal = tal->next) comma_collate(&typestr, tal->arg);
for (ml = mlrev; ml; ml = ml->prev) {
if (typestr) {
char *type, *types = typestr;
int len, skip = strncmp(types, "no", 2);
for (;;) {
if (!(type = comma_iterate(&types, &len))) break;
if (!skip) {
// If one -t starts with "no", the rest must too
if (strncmp(type, "no", 2)) error_exit("bad -t");
if (!strncmp(type+2, ml->type, len-2)) {
skip = 1;
break;
}
} else if (!strncmp(type, ml->type, len) && !ml->type[len]) {
skip = 0;
break;
}
}
if (skip) continue;
}
do_umount(ml->dir, ml->device, flags);
}
if (CFG_TOYBOX_FREE) {
free(typestr);
llist_traverse(mlsave, free);
}
// TODO: under what circumstances do we umount non-absolute path?
} else for (optargs = toys.optargs; *optargs; optargs++) {
char *abs = xabspath(*optargs, 0);
for (ml = abs ? mlrev : 0; ml; ml = ml->prev) {
if (!strcmp(ml->dir, abs)) break;
if (!strcmp(ml->device, abs)) {
free(abs);
abs = ml->dir;
break;
}
}
do_umount(abs ? abs : *optargs, ml ? ml->device : 0, flags);
if (ml && abs != ml->dir) free(abs);
}
}
|
