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3bd94003 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
6bbc923d HK |
2 | |
3 | /* | |
6bbc923d HK |
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> | |
035641b0 | 10 | #include <linux/delay.h> |
6bbc923d HK |
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 | |
035641b0 | 21 | #define DM_MAX_WAITFOR 256 |
6bbc923d HK |
22 | |
23 | static char *create; | |
24 | ||
035641b0 PK |
25 | static char *waitfor[DM_MAX_WAITFOR]; |
26 | ||
6bbc923d HK |
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> | |
035641b0 PK |
30 | * Block devices to wait for to become available before setting up tables: |
31 | * dm-mod.waitfor=<device1>[,..,<deviceN>] | |
6bbc923d | 32 | * |
6cf2a73c | 33 | * See Documentation/admin-guide/device-mapper/dm-init.rst for dm-mod.create="..." format |
6bbc923d HK |
34 | * details. |
35 | */ | |
36 | ||
37 | struct 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 | ||
90e6bf06 | 44 | static const char * const dm_allowed_targets[] __initconst = { |
6bbc923d HK |
45 | "crypt", |
46 | "delay", | |
47 | "linear", | |
48 | "snapshot-origin", | |
49 | "striped", | |
50 | "verity", | |
51 | }; | |
52 | ||
53 | static 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 | ||
64 | static 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 | */ | |
88 | static 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 | */ | |
111 | static 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 */ | |
dec7e649 GZ |
148 | dev->target_args_array[n] = kstrndup(field[3], DM_MAX_STR_SIZE, |
149 | GFP_KERNEL); | |
6bbc923d HK |
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 | */ | |
162 | static 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); | |
8e890c1a | 168 | if (++dev->dmi.target_count > DM_MAX_TARGETS) { |
6bbc923d HK |
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 | */ | |
192 | static 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 | */ | |
237 | static 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 | ||
8e890c1a HK |
250 | if (++ndev > DM_MAX_DEVICES) { |
251 | DMERR("too many devices %lu > %d", | |
252 | ndev, DM_MAX_DEVICES); | |
6bbc923d HK |
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 | */ | |
269 | static int __init dm_init_init(void) | |
270 | { | |
271 | struct dm_device *dev; | |
272 | LIST_HEAD(devices); | |
273 | char *str; | |
035641b0 | 274 | int i, r; |
6bbc923d HK |
275 | |
276 | if (!create) | |
277 | return 0; | |
278 | ||
279 | if (strlen(create) >= DM_MAX_STR_SIZE) { | |
10c9c8e7 | 280 | DMERR("Argument is too big. Limit is %d", DM_MAX_STR_SIZE); |
6bbc923d HK |
281 | return -EINVAL; |
282 | } | |
dec7e649 | 283 | str = kstrndup(create, DM_MAX_STR_SIZE, GFP_KERNEL); |
6bbc923d HK |
284 | if (!str) |
285 | return -ENOMEM; | |
286 | ||
287 | r = dm_parse_devices(&devices, str); | |
288 | if (r) | |
289 | goto out; | |
290 | ||
10c9c8e7 | 291 | DMINFO("waiting for all devices to be available before creating mapped devices"); |
6bbc923d HK |
292 | wait_for_device_probe(); |
293 | ||
035641b0 PK |
294 | for (i = 0; i < ARRAY_SIZE(waitfor); i++) { |
295 | if (waitfor[i]) { | |
49177377 CH |
296 | dev_t dev; |
297 | ||
035641b0 | 298 | DMINFO("waiting for device %s ...", waitfor[i]); |
49177377 | 299 | while (early_lookup_bdev(waitfor[i], &dev)) |
238d991f | 300 | fsleep(5000); |
035641b0 PK |
301 | } |
302 | } | |
303 | ||
304 | if (waitfor[0]) | |
305 | DMINFO("all devices available"); | |
306 | ||
6bbc923d HK |
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 | } | |
312 | out: | |
313 | kfree(str); | |
314 | dm_setup_cleanup(&devices); | |
315 | return r; | |
316 | } | |
317 | ||
318 | late_initcall(dm_init_init); | |
319 | ||
320 | module_param(create, charp, 0); | |
321 | MODULE_PARM_DESC(create, "Create a mapped device in early boot"); | |
035641b0 PK |
322 | |
323 | module_param_array(waitfor, charp, NULL, 0); | |
324 | MODULE_PARM_DESC(waitfor, "Devices to wait for before setting up tables"); |