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
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
|
// SPDX-License-Identifier: GPL-2.0
/*
* dm-init.c
* Copyright (C) 2017 The Chromium OS Authors <chromium-os-dev@chromium.org>
*
* This file is released under the GPLv2.
*/
#include <linux/ctype.h>
#include <linux/device.h>
#include <linux/device-mapper.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/moduleparam.h>
#define DM_MSG_PREFIX "init"
#define DM_MAX_DEVICES 256
#define DM_MAX_TARGETS 256
#define DM_MAX_STR_SIZE 4096
static char *create;
/*
* Format: dm-mod.create=<name>,<uuid>,<minor>,<flags>,<table>[,<table>+][;<name>,<uuid>,<minor>,<flags>,<table>[,<table>+]+]
* Table format: <start_sector> <num_sectors> <target_type> <target_args>
*
* See Documentation/device-mapper/dm-init.txt for dm-mod.create="..." format
* details.
*/
struct dm_device {
struct dm_ioctl dmi;
struct dm_target_spec *table[DM_MAX_TARGETS];
char *target_args_array[DM_MAX_TARGETS];
struct list_head list;
};
const char * const dm_allowed_targets[] __initconst = {
"crypt",
"delay",
"linear",
"snapshot-origin",
"striped",
"verity",
};
static int __init dm_verify_target_type(const char *target)
{
unsigned int i;
for (i = 0; i < ARRAY_SIZE(dm_allowed_targets); i++) {
if (!strcmp(dm_allowed_targets[i], target))
return 0;
}
return -EINVAL;
}
static void __init dm_setup_cleanup(struct list_head *devices)
{
struct dm_device *dev, *tmp;
unsigned int i;
list_for_each_entry_safe(dev, tmp, devices, list) {
list_del(&dev->list);
for (i = 0; i < dev->dmi.target_count; i++) {
kfree(dev->table[i]);
kfree(dev->target_args_array[i]);
}
kfree(dev);
}
}
/**
* str_field_delimit - delimit a string based on a separator char.
* @str: the pointer to the string to delimit.
* @separator: char that delimits the field
*
* Find a @separator and replace it by '\0'.
* Remove leading and trailing spaces.
* Return the remainder string after the @separator.
*/
static char __init *str_field_delimit(char **str, char separator)
{
char *s;
/* TODO: add support for escaped characters */
*str = skip_spaces(*str);
s = strchr(*str, separator);
/* Delimit the field and remove trailing spaces */
if (s)
*s = '\0';
*str = strim(*str);
return s ? ++s : NULL;
}
/**
* dm_parse_table_entry - parse a table entry
* @dev: device to store the parsed information.
* @str: the pointer to a string with the format:
* <start_sector> <num_sectors> <target_type> <target_args>[, ...]
*
* Return the remainder string after the table entry, i.e, after the comma which
* delimits the entry or NULL if reached the end of the string.
*/
static char __init *dm_parse_table_entry(struct dm_device *dev, char *str)
{
const unsigned int n = dev->dmi.target_count - 1;
struct dm_target_spec *sp;
unsigned int i;
/* fields: */
char *field[4];
char *next;
field[0] = str;
/* Delimit first 3 fields that are separated by space */
for (i = 0; i < ARRAY_SIZE(field) - 1; i++) {
field[i + 1] = str_field_delimit(&field[i], ' ');
if (!field[i + 1])
return ERR_PTR(-EINVAL);
}
/* Delimit last field that can be terminated by comma */
next = str_field_delimit(&field[i], ',');
sp = kzalloc(sizeof(*sp), GFP_KERNEL);
if (!sp)
return ERR_PTR(-ENOMEM);
dev->table[n] = sp;
/* start_sector */
if (kstrtoull(field[0], 0, &sp->sector_start))
return ERR_PTR(-EINVAL);
/* num_sector */
if (kstrtoull(field[1], 0, &sp->length))
return ERR_PTR(-EINVAL);
/* target_type */
strscpy(sp->target_type, field[2], sizeof(sp->target_type));
if (dm_verify_target_type(sp->target_type)) {
DMERR("invalid type \"%s\"", sp->target_type);
return ERR_PTR(-EINVAL);
}
/* target_args */
dev->target_args_array[n] = kstrndup(field[3], GFP_KERNEL,
DM_MAX_STR_SIZE);
if (!dev->target_args_array[n])
return ERR_PTR(-ENOMEM);
return next;
}
/**
* dm_parse_table - parse "dm-mod.create=" table field
* @dev: device to store the parsed information.
* @str: the pointer to a string with the format:
* <table>[,<table>+]
*/
static int __init dm_parse_table(struct dm_device *dev, char *str)
{
char *table_entry = str;
while (table_entry) {
DMDEBUG("parsing table \"%s\"", str);
if (++dev->dmi.target_count >= DM_MAX_TARGETS) {
DMERR("too many targets %u > %d",
dev->dmi.target_count, DM_MAX_TARGETS);
return -EINVAL;
}
table_entry = dm_parse_table_entry(dev, table_entry);
if (IS_ERR(table_entry)) {
DMERR("couldn't parse table");
return PTR_ERR(table_entry);
}
}
return 0;
}
/**
* dm_parse_device_entry - parse a device entry
* @dev: device to store the parsed information.
* @str: the pointer to a string with the format:
* name,uuid,minor,flags,table[; ...]
*
* Return the remainder string after the table entry, i.e, after the semi-colon
* which delimits the entry or NULL if reached the end of the string.
*/
static char __init *dm_parse_device_entry(struct dm_device *dev, char *str)
{
/* There are 5 fields: name,uuid,minor,flags,table; */
char *field[5];
unsigned int i;
char *next;
field[0] = str;
/* Delimit first 4 fields that are separated by comma */
for (i = 0; i < ARRAY_SIZE(field) - 1; i++) {
field[i+1] = str_field_delimit(&field[i], ',');
if (!field[i+1])
return ERR_PTR(-EINVAL);
}
/* Delimit last field that can be delimited by semi-colon */
next = str_field_delimit(&field[i], ';');
/* name */
strscpy(dev->dmi.name, field[0], sizeof(dev->dmi.name));
/* uuid */
strscpy(dev->dmi.uuid, field[1], sizeof(dev->dmi.uuid));
/* minor */
if (strlen(field[2])) {
if (kstrtoull(field[2], 0, &dev->dmi.dev))
return ERR_PTR(-EINVAL);
dev->dmi.flags |= DM_PERSISTENT_DEV_FLAG;
}
/* flags */
if (!strcmp(field[3], "ro"))
dev->dmi.flags |= DM_READONLY_FLAG;
else if (strcmp(field[3], "rw"))
return ERR_PTR(-EINVAL);
/* table */
if (dm_parse_table(dev, field[4]))
return ERR_PTR(-EINVAL);
return next;
}
/**
* dm_parse_devices - parse "dm-mod.create=" argument
* @devices: list of struct dm_device to store the parsed information.
* @str: the pointer to a string with the format:
* <device>[;<device>+]
*/
static int __init dm_parse_devices(struct list_head *devices, char *str)
{
unsigned long ndev = 0;
struct dm_device *dev;
char *device = str;
DMDEBUG("parsing \"%s\"", str);
while (device) {
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (!dev)
return -ENOMEM;
list_add_tail(&dev->list, devices);
if (++ndev >= DM_MAX_DEVICES) {
DMERR("too many targets %u > %d",
dev->dmi.target_count, DM_MAX_TARGETS);
return -EINVAL;
}
device = dm_parse_device_entry(dev, device);
if (IS_ERR(device)) {
DMERR("couldn't parse device");
return PTR_ERR(device);
}
}
return 0;
}
/**
* dm_init_init - parse "dm-mod.create=" argument and configure drivers
*/
static int __init dm_init_init(void)
{
struct dm_device *dev;
LIST_HEAD(devices);
char *str;
int r;
if (!create)
return 0;
if (strlen(create) >= DM_MAX_STR_SIZE) {
DMERR("Argument is too big. Limit is %d\n", DM_MAX_STR_SIZE);
return -EINVAL;
}
str = kstrndup(create, GFP_KERNEL, DM_MAX_STR_SIZE);
if (!str)
return -ENOMEM;
r = dm_parse_devices(&devices, str);
if (r)
goto out;
DMINFO("waiting for all devices to be available before creating mapped devices\n");
wait_for_device_probe();
list_for_each_entry(dev, &devices, list) {
if (dm_early_create(&dev->dmi, dev->table,
dev->target_args_array))
break;
}
out:
kfree(str);
|