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1// SPDX-License-Identifier: GPL-2.0
2
3/*
4 * dm-init.c
5 * Copyright (C) 2017 The Chromium OS Authors <chromium-os-dev@chromium.org>
6 *
7 * This file is released under the GPLv2.
8 */
9
10#include <linux/ctype.h>
11#include <linux/delay.h>
12#include <linux/device.h>
13#include <linux/device-mapper.h>
14#include <linux/init.h>
15#include <linux/list.h>
16#include <linux/moduleparam.h>
17
18#define DM_MSG_PREFIX "init"
19#define DM_MAX_DEVICES 256
20#define DM_MAX_TARGETS 256
21#define DM_MAX_STR_SIZE 4096
22#define DM_MAX_WAITFOR 256
23
24static char *create;
25
26static char *waitfor[DM_MAX_WAITFOR];
27
28/*
29 * Format: dm-mod.create=<name>,<uuid>,<minor>,<flags>,<table>[,<table>+][;<name>,<uuid>,<minor>,<flags>,<table>[,<table>+]+]
30 * Table format: <start_sector> <num_sectors> <target_type> <target_args>
31 * Block devices to wait for to become available before setting up tables:
32 * dm-mod.waitfor=<device1>[,..,<deviceN>]
33 *
34 * See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..." format
35 * details.
36 */
37
38struct dm_device {
39 struct dm_ioctl dmi;
40 struct dm_target_spec *table[DM_MAX_TARGETS];
41 char *target_args_array[DM_MAX_TARGETS];
42 struct list_head list;
43};
44
45static const char * const dm_allowed_targets[] __initconst = {
46 "crypt",
47 "delay",
48 "linear",
49 "snapshot-origin",
50 "striped",
51 "verity",
52};
53
54static int __init dm_verify_target_type(const char *target)
55{
56 unsigned int i;
57
58 for (i = 0; i < ARRAY_SIZE(dm_allowed_targets); i++) {
59 if (!strcmp(dm_allowed_targets[i], target))
60 return 0;
61 }
62 return -EINVAL;
63}
64
65static void __init dm_setup_cleanup(struct list_head *devices)
66{
67 struct dm_device *dev, *tmp;
68 unsigned int i;
69
70 list_for_each_entry_safe(dev, tmp, devices, list) {
71 list_del(&dev->list);
72 for (i = 0; i < dev->dmi.target_count; i++) {
73 kfree(dev->table[i]);
74 kfree(dev->target_args_array[i]);
75 }
76 kfree(dev);
77 }
78}
79
80/**
81 * str_field_delimit - delimit a string based on a separator char.
82 * @str: the pointer to the string to delimit.
83 * @separator: char that delimits the field
84 *
85 * Find a @separator and replace it by '\0'.
86 * Remove leading and trailing spaces.
87 * Return the remainder string after the @separator.
88 */
89static char __init *str_field_delimit(char **str, char separator)
90{
91 char *s;
92
93 /* TODO: add support for escaped characters */
94 *str = skip_spaces(*str);
95 s = strchr(*str, separator);
96 /* Delimit the field and remove trailing spaces */
97 if (s)
98 *s = '\0';
99 *str = strim(*str);
100 return s ? ++s : NULL;
101}
102
103/**
104 * dm_parse_table_entry - parse a table entry
105 * @dev: device to store the parsed information.
106 * @str: the pointer to a string with the format:
107 * <start_sector> <num_sectors> <target_type> <target_args>[, ...]
108 *
109 * Return the remainder string after the table entry, i.e, after the comma which
110 * delimits the entry or NULL if reached the end of the string.
111 */
112static char __init *dm_parse_table_entry(struct dm_device *dev, char *str)
113{
114 const unsigned int n = dev->dmi.target_count - 1;
115 struct dm_target_spec *sp;
116 unsigned int i;
117 /* fields: */
118 char *field[4];
119 char *next;
120
121 field[0] = str;
122 /* Delimit first 3 fields that are separated by space */
123 for (i = 0; i < ARRAY_SIZE(field) - 1; i++) {
124 field[i + 1] = str_field_delimit(&field[i], ' ');
125 if (!field[i + 1])
126 return ERR_PTR(-EINVAL);
127 }
128 /* Delimit last field that can be terminated by comma */
129 next = str_field_delimit(&field[i], ',');
130
131 sp = kzalloc(sizeof(*sp), GFP_KERNEL);
132 if (!sp)
133 return ERR_PTR(-ENOMEM);
134 dev->table[n] = sp;
135
136 /* start_sector */
137 if (kstrtoull(field[0], 0, &sp->sector_start))
138 return ERR_PTR(-EINVAL);
139 /* num_sector */
140 if (kstrtoull(field[1], 0, &sp->length))
141 return ERR_PTR(-EINVAL);
142 /* target_type */
143 strscpy(sp->target_type, field[2], sizeof(sp->target_type));
144 if (dm_verify_target_type(sp->target_type)) {
145 DMERR("invalid type \"%s\"", sp->target_type);
146 return ERR_PTR(-EINVAL);
147 }
148 /* target_args */
149 dev->target_args_array[n] = kstrndup(field[3], DM_MAX_STR_SIZE,
150 GFP_KERNEL);
151 if (!dev->target_args_array[n])
152 return ERR_PTR(-ENOMEM);
153
154 return next;
155}
156
157/**
158 * dm_parse_table - parse "dm-mod.create=" table field
159 * @dev: device to store the parsed information.
160 * @str: the pointer to a string with the format:
161 * <table>[,<table>+]
162 */
163static int __init dm_parse_table(struct dm_device *dev, char *str)
164{
165 char *table_entry = str;
166
167 while (table_entry) {
168 DMDEBUG("parsing table \"%s\"", str);
169 if (++dev->dmi.target_count > DM_MAX_TARGETS) {
170 DMERR("too many targets %u > %d",
171 dev->dmi.target_count, DM_MAX_TARGETS);
172 return -EINVAL;
173 }
174 table_entry = dm_parse_table_entry(dev, table_entry);
175 if (IS_ERR(table_entry)) {
176 DMERR("couldn't parse table");
177 return PTR_ERR(table_entry);
178 }
179 }
180
181 return 0;
182}
183
184/**
185 * dm_parse_device_entry - parse a device entry
186 * @dev: device to store the parsed information.
187 * @str: the pointer to a string with the format:
188 * name,uuid,minor,flags,table[; ...]
189 *
190 * Return the remainder string after the table entry, i.e, after the semi-colon
191 * which delimits the entry or NULL if reached the end of the string.
192 */
193static char __init *dm_parse_device_entry(struct dm_device *dev, char *str)
194{
195 /* There are 5 fields: name,uuid,minor,flags,table; */
196 char *field[5];
197 unsigned int i;
198 char *next;
199
200 field[0] = str;
201 /* Delimit first 4 fields that are separated by comma */
202 for (i = 0; i < ARRAY_SIZE(field) - 1; i++) {
203 field[i+1] = str_field_delimit(&field[i], ',');
204 if (!field[i+1])
205 return ERR_PTR(-EINVAL);
206 }
207 /* Delimit last field that can be delimited by semi-colon */
208 next = str_field_delimit(&field[i], ';');
209
210 /* name */
211 strscpy(dev->dmi.name, field[0], sizeof(dev->dmi.name));
212 /* uuid */
213 strscpy(dev->dmi.uuid, field[1], sizeof(dev->dmi.uuid));
214 /* minor */
215 if (strlen(field[2])) {
216 if (kstrtoull(field[2], 0, &dev->dmi.dev))
217 return ERR_PTR(-EINVAL);
218 dev->dmi.flags |= DM_PERSISTENT_DEV_FLAG;
219 }
220 /* flags */
221 if (!strcmp(field[3], "ro"))
222 dev->dmi.flags |= DM_READONLY_FLAG;
223 else if (strcmp(field[3], "rw"))
224 return ERR_PTR(-EINVAL);
225 /* table */
226 if (dm_parse_table(dev, field[4]))
227 return ERR_PTR(-EINVAL);
228
229 return next;
230}
231
232/**
233 * dm_parse_devices - parse "dm-mod.create=" argument
234 * @devices: list of struct dm_device to store the parsed information.
235 * @str: the pointer to a string with the format:
236 * <device>[;<device>+]
237 */
238static int __init dm_parse_devices(struct list_head *devices, char *str)
239{
240 unsigned long ndev = 0;
241 struct dm_device *dev;
242 char *device = str;
243
244 DMDEBUG("parsing \"%s\"", str);
245 while (device) {
246 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
247 if (!dev)
248 return -ENOMEM;
249 list_add_tail(&dev->list, devices);
250
251 if (++ndev > DM_MAX_DEVICES) {
252 DMERR("too many devices %lu > %d",
253 ndev, DM_MAX_DEVICES);
254 return -EINVAL;
255 }
256
257 device = dm_parse_device_entry(dev, device);
258 if (IS_ERR(device)) {
259 DMERR("couldn't parse device");
260 return PTR_ERR(device);
261 }
262 }
263
264 return 0;
265}
266
267/**
268 * dm_init_init - parse "dm-mod.create=" argument and configure drivers
269 */
270static int __init dm_init_init(void)
271{
272 struct dm_device *dev;
273 LIST_HEAD(devices);
274 char *str;
275 int i, r;
276
277 if (!create)
278 return 0;
279
280 if (strlen(create) >= DM_MAX_STR_SIZE) {
281 DMERR("Argument is too big. Limit is %d", DM_MAX_STR_SIZE);
282 return -EINVAL;
283 }
284 str = kstrndup(create, DM_MAX_STR_SIZE, GFP_KERNEL);
285 if (!str)
286 return -ENOMEM;
287
288 r = dm_parse_devices(&devices, str);
289 if (r)
290 goto out;
291
292 DMINFO("waiting for all devices to be available before creating mapped devices");
293 wait_for_device_probe();
294
295 for (i = 0; i < ARRAY_SIZE(waitfor); i++) {
296 if (waitfor[i]) {
297 DMINFO("waiting for device %s ...", waitfor[i]);
298 while (!dm_get_dev_t(waitfor[i]))
299 msleep(5);
300 }
301 }
302
303 if (waitfor[0])
304 DMINFO("all devices available");
305
306 list_for_each_entry(dev, &devices, list) {
307 if (dm_early_create(&dev->dmi, dev->table,
308 dev->target_args_array))
309 break;
310 }
311out:
312 kfree(str);
313 dm_setup_cleanup(&devices);
314 return r;
315}
316
317late_initcall(dm_init_init);
318
319module_param(create, charp, 0);
320MODULE_PARM_DESC(create, "Create a mapped device in early boot");
321
322module_param_array(waitfor, charp, NULL, 0);
323MODULE_PARM_DESC(waitfor, "Devices to wait for before setting up tables");
1// SPDX-License-Identifier: GPL-2.0-only
2
3/*
4 * Copyright (C) 2017 The Chromium OS Authors <chromium-os-dev@chromium.org>
5 *
6 * This file is released under the GPLv2.
7 */
8
9#include <linux/ctype.h>
10#include <linux/delay.h>
11#include <linux/device.h>
12#include <linux/device-mapper.h>
13#include <linux/init.h>
14#include <linux/list.h>
15#include <linux/moduleparam.h>
16
17#define DM_MSG_PREFIX "init"
18#define DM_MAX_DEVICES 256
19#define DM_MAX_TARGETS 256
20#define DM_MAX_STR_SIZE 4096
21#define DM_MAX_WAITFOR 256
22
23static char *create;
24
25static char *waitfor[DM_MAX_WAITFOR];
26
27/*
28 * Format: dm-mod.create=<name>,<uuid>,<minor>,<flags>,<table>[,<table>+][;<name>,<uuid>,<minor>,<flags>,<table>[,<table>+]+]
29 * Table format: <start_sector> <num_sectors> <target_type> <target_args>
30 * Block devices to wait for to become available before setting up tables:
31 * dm-mod.waitfor=<device1>[,..,<deviceN>]
32 *
33 * See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..." format
34 * details.
35 */
36
37struct dm_device {
38 struct dm_ioctl dmi;
39 struct dm_target_spec *table[DM_MAX_TARGETS];
40 char *target_args_array[DM_MAX_TARGETS];
41 struct list_head list;
42};
43
44static const char * const dm_allowed_targets[] __initconst = {
45 "crypt",
46 "delay",
47 "linear",
48 "snapshot-origin",
49 "striped",
50 "verity",
51};
52
53static int __init dm_verify_target_type(const char *target)
54{
55 unsigned int i;
56
57 for (i = 0; i < ARRAY_SIZE(dm_allowed_targets); i++) {
58 if (!strcmp(dm_allowed_targets[i], target))
59 return 0;
60 }
61 return -EINVAL;
62}
63
64static void __init dm_setup_cleanup(struct list_head *devices)
65{
66 struct dm_device *dev, *tmp;
67 unsigned int i;
68
69 list_for_each_entry_safe(dev, tmp, devices, list) {
70 list_del(&dev->list);
71 for (i = 0; i < dev->dmi.target_count; i++) {
72 kfree(dev->table[i]);
73 kfree(dev->target_args_array[i]);
74 }
75 kfree(dev);
76 }
77}
78
79/**
80 * str_field_delimit - delimit a string based on a separator char.
81 * @str: the pointer to the string to delimit.
82 * @separator: char that delimits the field
83 *
84 * Find a @separator and replace it by '\0'.
85 * Remove leading and trailing spaces.
86 * Return the remainder string after the @separator.
87 */
88static char __init *str_field_delimit(char **str, char separator)
89{
90 char *s;
91
92 /* TODO: add support for escaped characters */
93 *str = skip_spaces(*str);
94 s = strchr(*str, separator);
95 /* Delimit the field and remove trailing spaces */
96 if (s)
97 *s = '\0';
98 *str = strim(*str);
99 return s ? ++s : NULL;
100}
101
102/**
103 * dm_parse_table_entry - parse a table entry
104 * @dev: device to store the parsed information.
105 * @str: the pointer to a string with the format:
106 * <start_sector> <num_sectors> <target_type> <target_args>[, ...]
107 *
108 * Return the remainder string after the table entry, i.e, after the comma which
109 * delimits the entry or NULL if reached the end of the string.
110 */
111static char __init *dm_parse_table_entry(struct dm_device *dev, char *str)
112{
113 const unsigned int n = dev->dmi.target_count - 1;
114 struct dm_target_spec *sp;
115 unsigned int i;
116 /* fields: */
117 char *field[4];
118 char *next;
119
120 field[0] = str;
121 /* Delimit first 3 fields that are separated by space */
122 for (i = 0; i < ARRAY_SIZE(field) - 1; i++) {
123 field[i + 1] = str_field_delimit(&field[i], ' ');
124 if (!field[i + 1])
125 return ERR_PTR(-EINVAL);
126 }
127 /* Delimit last field that can be terminated by comma */
128 next = str_field_delimit(&field[i], ',');
129
130 sp = kzalloc(sizeof(*sp), GFP_KERNEL);
131 if (!sp)
132 return ERR_PTR(-ENOMEM);
133 dev->table[n] = sp;
134
135 /* start_sector */
136 if (kstrtoull(field[0], 0, &sp->sector_start))
137 return ERR_PTR(-EINVAL);
138 /* num_sector */
139 if (kstrtoull(field[1], 0, &sp->length))
140 return ERR_PTR(-EINVAL);
141 /* target_type */
142 strscpy(sp->target_type, field[2], sizeof(sp->target_type));
143 if (dm_verify_target_type(sp->target_type)) {
144 DMERR("invalid type \"%s\"", sp->target_type);
145 return ERR_PTR(-EINVAL);
146 }
147 /* target_args */
148 dev->target_args_array[n] = kstrndup(field[3], DM_MAX_STR_SIZE,
149 GFP_KERNEL);
150 if (!dev->target_args_array[n])
151 return ERR_PTR(-ENOMEM);
152
153 return next;
154}
155
156/**
157 * dm_parse_table - parse "dm-mod.create=" table field
158 * @dev: device to store the parsed information.
159 * @str: the pointer to a string with the format:
160 * <table>[,<table>+]
161 */
162static int __init dm_parse_table(struct dm_device *dev, char *str)
163{
164 char *table_entry = str;
165
166 while (table_entry) {
167 DMDEBUG("parsing table \"%s\"", str);
168 if (++dev->dmi.target_count > DM_MAX_TARGETS) {
169 DMERR("too many targets %u > %d",
170 dev->dmi.target_count, DM_MAX_TARGETS);
171 return -EINVAL;
172 }
173 table_entry = dm_parse_table_entry(dev, table_entry);
174 if (IS_ERR(table_entry)) {
175 DMERR("couldn't parse table");
176 return PTR_ERR(table_entry);
177 }
178 }
179
180 return 0;
181}
182
183/**
184 * dm_parse_device_entry - parse a device entry
185 * @dev: device to store the parsed information.
186 * @str: the pointer to a string with the format:
187 * name,uuid,minor,flags,table[; ...]
188 *
189 * Return the remainder string after the table entry, i.e, after the semi-colon
190 * which delimits the entry or NULL if reached the end of the string.
191 */
192static char __init *dm_parse_device_entry(struct dm_device *dev, char *str)
193{
194 /* There are 5 fields: name,uuid,minor,flags,table; */
195 char *field[5];
196 unsigned int i;
197 char *next;
198
199 field[0] = str;
200 /* Delimit first 4 fields that are separated by comma */
201 for (i = 0; i < ARRAY_SIZE(field) - 1; i++) {
202 field[i+1] = str_field_delimit(&field[i], ',');
203 if (!field[i+1])
204 return ERR_PTR(-EINVAL);
205 }
206 /* Delimit last field that can be delimited by semi-colon */
207 next = str_field_delimit(&field[i], ';');
208
209 /* name */
210 strscpy(dev->dmi.name, field[0], sizeof(dev->dmi.name));
211 /* uuid */
212 strscpy(dev->dmi.uuid, field[1], sizeof(dev->dmi.uuid));
213 /* minor */
214 if (strlen(field[2])) {
215 if (kstrtoull(field[2], 0, &dev->dmi.dev))
216 return ERR_PTR(-EINVAL);
217 dev->dmi.flags |= DM_PERSISTENT_DEV_FLAG;
218 }
219 /* flags */
220 if (!strcmp(field[3], "ro"))
221 dev->dmi.flags |= DM_READONLY_FLAG;
222 else if (strcmp(field[3], "rw"))
223 return ERR_PTR(-EINVAL);
224 /* table */
225 if (dm_parse_table(dev, field[4]))
226 return ERR_PTR(-EINVAL);
227
228 return next;
229}
230
231/**
232 * dm_parse_devices - parse "dm-mod.create=" argument
233 * @devices: list of struct dm_device to store the parsed information.
234 * @str: the pointer to a string with the format:
235 * <device>[;<device>+]
236 */
237static int __init dm_parse_devices(struct list_head *devices, char *str)
238{
239 unsigned long ndev = 0;
240 struct dm_device *dev;
241 char *device = str;
242
243 DMDEBUG("parsing \"%s\"", str);
244 while (device) {
245 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
246 if (!dev)
247 return -ENOMEM;
248 list_add_tail(&dev->list, devices);
249
250 if (++ndev > DM_MAX_DEVICES) {
251 DMERR("too many devices %lu > %d",
252 ndev, DM_MAX_DEVICES);
253 return -EINVAL;
254 }
255
256 device = dm_parse_device_entry(dev, device);
257 if (IS_ERR(device)) {
258 DMERR("couldn't parse device");
259 return PTR_ERR(device);
260 }
261 }
262
263 return 0;
264}
265
266/**
267 * dm_init_init - parse "dm-mod.create=" argument and configure drivers
268 */
269static int __init dm_init_init(void)
270{
271 struct dm_device *dev;
272 LIST_HEAD(devices);
273 char *str;
274 int i, r;
275
276 if (!create)
277 return 0;
278
279 if (strlen(create) >= DM_MAX_STR_SIZE) {
280 DMERR("Argument is too big. Limit is %d", DM_MAX_STR_SIZE);
281 return -EINVAL;
282 }
283 str = kstrndup(create, DM_MAX_STR_SIZE, GFP_KERNEL);
284 if (!str)
285 return -ENOMEM;
286
287 r = dm_parse_devices(&devices, str);
288 if (r)
289 goto out;
290
291 DMINFO("waiting for all devices to be available before creating mapped devices");
292 wait_for_device_probe();
293
294 for (i = 0; i < ARRAY_SIZE(waitfor); i++) {
295 if (waitfor[i]) {
296 dev_t dev;
297
298 DMINFO("waiting for device %s ...", waitfor[i]);
299 while (early_lookup_bdev(waitfor[i], &dev))
300 fsleep(5000);
301 }
302 }
303
304 if (waitfor[0])
305 DMINFO("all devices available");
306
307 list_for_each_entry(dev, &devices, list) {
308 if (dm_early_create(&dev->dmi, dev->table,
309 dev->target_args_array))
310 break;
311 }
312out:
313 kfree(str);
314 dm_setup_cleanup(&devices);
315 return r;
316}
317
318late_initcall(dm_init_init);
319
320module_param(create, charp, 0);
321MODULE_PARM_DESC(create, "Create a mapped device in early boot");
322
323module_param_array(waitfor, charp, NULL, 0);
324MODULE_PARM_DESC(waitfor, "Devices to wait for before setting up tables");