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1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2001, 2002 Sistina Software (UK) Limited. | |
3 | * Copyright (C) 2004 - 2005 Red Hat, Inc. All rights reserved. | |
4 | * | |
5 | * This file is released under the GPL. | |
6 | */ | |
7 | ||
8 | #include "dm.h" | |
9 | ||
10 | #include <linux/module.h> | |
11 | #include <linux/vmalloc.h> | |
12 | #include <linux/miscdevice.h> | |
13 | #include <linux/init.h> | |
14 | #include <linux/wait.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/devfs_fs_kernel.h> | |
17 | #include <linux/dm-ioctl.h> | |
3ac51e74 | 18 | #include <linux/hdreg.h> |
1da177e4 LT |
19 | |
20 | #include <asm/uaccess.h> | |
21 | ||
22 | #define DM_DRIVER_EMAIL "dm-devel@redhat.com" | |
23 | ||
24 | /*----------------------------------------------------------------- | |
25 | * The ioctl interface needs to be able to look up devices by | |
26 | * name or uuid. | |
27 | *---------------------------------------------------------------*/ | |
28 | struct hash_cell { | |
29 | struct list_head name_list; | |
30 | struct list_head uuid_list; | |
31 | ||
32 | char *name; | |
33 | char *uuid; | |
34 | struct mapped_device *md; | |
35 | struct dm_table *new_map; | |
36 | }; | |
37 | ||
38 | struct vers_iter { | |
39 | size_t param_size; | |
40 | struct dm_target_versions *vers, *old_vers; | |
41 | char *end; | |
42 | uint32_t flags; | |
43 | }; | |
44 | ||
45 | ||
46 | #define NUM_BUCKETS 64 | |
47 | #define MASK_BUCKETS (NUM_BUCKETS - 1) | |
48 | static struct list_head _name_buckets[NUM_BUCKETS]; | |
49 | static struct list_head _uuid_buckets[NUM_BUCKETS]; | |
50 | ||
51 | static void dm_hash_remove_all(void); | |
52 | ||
53 | /* | |
54 | * Guards access to both hash tables. | |
55 | */ | |
56 | static DECLARE_RWSEM(_hash_lock); | |
57 | ||
58 | static void init_buckets(struct list_head *buckets) | |
59 | { | |
60 | unsigned int i; | |
61 | ||
62 | for (i = 0; i < NUM_BUCKETS; i++) | |
63 | INIT_LIST_HEAD(buckets + i); | |
64 | } | |
65 | ||
66 | static int dm_hash_init(void) | |
67 | { | |
68 | init_buckets(_name_buckets); | |
69 | init_buckets(_uuid_buckets); | |
70 | devfs_mk_dir(DM_DIR); | |
71 | return 0; | |
72 | } | |
73 | ||
74 | static void dm_hash_exit(void) | |
75 | { | |
76 | dm_hash_remove_all(); | |
77 | devfs_remove(DM_DIR); | |
78 | } | |
79 | ||
80 | /*----------------------------------------------------------------- | |
81 | * Hash function: | |
82 | * We're not really concerned with the str hash function being | |
83 | * fast since it's only used by the ioctl interface. | |
84 | *---------------------------------------------------------------*/ | |
85 | static unsigned int hash_str(const char *str) | |
86 | { | |
87 | const unsigned int hash_mult = 2654435387U; | |
88 | unsigned int h = 0; | |
89 | ||
90 | while (*str) | |
91 | h = (h + (unsigned int) *str++) * hash_mult; | |
92 | ||
93 | return h & MASK_BUCKETS; | |
94 | } | |
95 | ||
96 | /*----------------------------------------------------------------- | |
97 | * Code for looking up a device by name | |
98 | *---------------------------------------------------------------*/ | |
99 | static struct hash_cell *__get_name_cell(const char *str) | |
100 | { | |
101 | struct hash_cell *hc; | |
102 | unsigned int h = hash_str(str); | |
103 | ||
104 | list_for_each_entry (hc, _name_buckets + h, name_list) | |
105 | if (!strcmp(hc->name, str)) | |
106 | return hc; | |
107 | ||
108 | return NULL; | |
109 | } | |
110 | ||
111 | static struct hash_cell *__get_uuid_cell(const char *str) | |
112 | { | |
113 | struct hash_cell *hc; | |
114 | unsigned int h = hash_str(str); | |
115 | ||
116 | list_for_each_entry (hc, _uuid_buckets + h, uuid_list) | |
117 | if (!strcmp(hc->uuid, str)) | |
118 | return hc; | |
119 | ||
120 | return NULL; | |
121 | } | |
122 | ||
123 | /*----------------------------------------------------------------- | |
124 | * Inserting, removing and renaming a device. | |
125 | *---------------------------------------------------------------*/ | |
1da177e4 LT |
126 | static struct hash_cell *alloc_cell(const char *name, const char *uuid, |
127 | struct mapped_device *md) | |
128 | { | |
129 | struct hash_cell *hc; | |
130 | ||
131 | hc = kmalloc(sizeof(*hc), GFP_KERNEL); | |
132 | if (!hc) | |
133 | return NULL; | |
134 | ||
543537bd | 135 | hc->name = kstrdup(name, GFP_KERNEL); |
1da177e4 LT |
136 | if (!hc->name) { |
137 | kfree(hc); | |
138 | return NULL; | |
139 | } | |
140 | ||
141 | if (!uuid) | |
142 | hc->uuid = NULL; | |
143 | ||
144 | else { | |
543537bd | 145 | hc->uuid = kstrdup(uuid, GFP_KERNEL); |
1da177e4 LT |
146 | if (!hc->uuid) { |
147 | kfree(hc->name); | |
148 | kfree(hc); | |
149 | return NULL; | |
150 | } | |
151 | } | |
152 | ||
153 | INIT_LIST_HEAD(&hc->name_list); | |
154 | INIT_LIST_HEAD(&hc->uuid_list); | |
155 | hc->md = md; | |
156 | hc->new_map = NULL; | |
157 | return hc; | |
158 | } | |
159 | ||
160 | static void free_cell(struct hash_cell *hc) | |
161 | { | |
162 | if (hc) { | |
163 | kfree(hc->name); | |
164 | kfree(hc->uuid); | |
165 | kfree(hc); | |
166 | } | |
167 | } | |
168 | ||
169 | /* | |
170 | * devfs stuff. | |
171 | */ | |
172 | static int register_with_devfs(struct hash_cell *hc) | |
173 | { | |
174 | struct gendisk *disk = dm_disk(hc->md); | |
175 | ||
176 | devfs_mk_bdev(MKDEV(disk->major, disk->first_minor), | |
177 | S_IFBLK | S_IRUSR | S_IWUSR | S_IRGRP, | |
178 | DM_DIR "/%s", hc->name); | |
179 | return 0; | |
180 | } | |
181 | ||
182 | static int unregister_with_devfs(struct hash_cell *hc) | |
183 | { | |
184 | devfs_remove(DM_DIR"/%s", hc->name); | |
185 | return 0; | |
186 | } | |
187 | ||
188 | /* | |
189 | * The kdev_t and uuid of a device can never change once it is | |
190 | * initially inserted. | |
191 | */ | |
192 | static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md) | |
193 | { | |
194 | struct hash_cell *cell; | |
195 | ||
196 | /* | |
197 | * Allocate the new cells. | |
198 | */ | |
199 | cell = alloc_cell(name, uuid, md); | |
200 | if (!cell) | |
201 | return -ENOMEM; | |
202 | ||
203 | /* | |
204 | * Insert the cell into both hash tables. | |
205 | */ | |
206 | down_write(&_hash_lock); | |
207 | if (__get_name_cell(name)) | |
208 | goto bad; | |
209 | ||
210 | list_add(&cell->name_list, _name_buckets + hash_str(name)); | |
211 | ||
212 | if (uuid) { | |
213 | if (__get_uuid_cell(uuid)) { | |
214 | list_del(&cell->name_list); | |
215 | goto bad; | |
216 | } | |
217 | list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid)); | |
218 | } | |
219 | register_with_devfs(cell); | |
220 | dm_get(md); | |
221 | dm_set_mdptr(md, cell); | |
222 | up_write(&_hash_lock); | |
223 | ||
224 | return 0; | |
225 | ||
226 | bad: | |
227 | up_write(&_hash_lock); | |
228 | free_cell(cell); | |
229 | return -EBUSY; | |
230 | } | |
231 | ||
232 | static void __hash_remove(struct hash_cell *hc) | |
233 | { | |
269fd2a6 | 234 | struct dm_table *table; |
235 | ||
1da177e4 LT |
236 | /* remove from the dev hash */ |
237 | list_del(&hc->uuid_list); | |
238 | list_del(&hc->name_list); | |
239 | unregister_with_devfs(hc); | |
240 | dm_set_mdptr(hc->md, NULL); | |
269fd2a6 | 241 | |
242 | table = dm_get_table(hc->md); | |
243 | if (table) { | |
244 | dm_table_event(table); | |
245 | dm_table_put(table); | |
246 | } | |
247 | ||
1da177e4 LT |
248 | if (hc->new_map) |
249 | dm_table_put(hc->new_map); | |
1134e5ae | 250 | dm_put(hc->md); |
1da177e4 LT |
251 | free_cell(hc); |
252 | } | |
253 | ||
254 | static void dm_hash_remove_all(void) | |
255 | { | |
256 | int i; | |
257 | struct hash_cell *hc; | |
258 | struct list_head *tmp, *n; | |
259 | ||
260 | down_write(&_hash_lock); | |
261 | for (i = 0; i < NUM_BUCKETS; i++) { | |
262 | list_for_each_safe (tmp, n, _name_buckets + i) { | |
263 | hc = list_entry(tmp, struct hash_cell, name_list); | |
264 | __hash_remove(hc); | |
265 | } | |
266 | } | |
267 | up_write(&_hash_lock); | |
268 | } | |
269 | ||
270 | static int dm_hash_rename(const char *old, const char *new) | |
271 | { | |
272 | char *new_name, *old_name; | |
273 | struct hash_cell *hc; | |
81f1777a | 274 | struct dm_table *table; |
1da177e4 LT |
275 | |
276 | /* | |
277 | * duplicate new. | |
278 | */ | |
543537bd | 279 | new_name = kstrdup(new, GFP_KERNEL); |
1da177e4 LT |
280 | if (!new_name) |
281 | return -ENOMEM; | |
282 | ||
283 | down_write(&_hash_lock); | |
284 | ||
285 | /* | |
286 | * Is new free ? | |
287 | */ | |
288 | hc = __get_name_cell(new); | |
289 | if (hc) { | |
290 | DMWARN("asked to rename to an already existing name %s -> %s", | |
291 | old, new); | |
292 | up_write(&_hash_lock); | |
293 | kfree(new_name); | |
294 | return -EBUSY; | |
295 | } | |
296 | ||
297 | /* | |
298 | * Is there such a device as 'old' ? | |
299 | */ | |
300 | hc = __get_name_cell(old); | |
301 | if (!hc) { | |
302 | DMWARN("asked to rename a non existent device %s -> %s", | |
303 | old, new); | |
304 | up_write(&_hash_lock); | |
305 | kfree(new_name); | |
306 | return -ENXIO; | |
307 | } | |
308 | ||
309 | /* | |
310 | * rename and move the name cell. | |
311 | */ | |
312 | unregister_with_devfs(hc); | |
313 | ||
314 | list_del(&hc->name_list); | |
315 | old_name = hc->name; | |
316 | hc->name = new_name; | |
317 | list_add(&hc->name_list, _name_buckets + hash_str(new_name)); | |
318 | ||
319 | /* rename the device node in devfs */ | |
320 | register_with_devfs(hc); | |
321 | ||
81f1777a | 322 | /* |
323 | * Wake up any dm event waiters. | |
324 | */ | |
325 | table = dm_get_table(hc->md); | |
326 | if (table) { | |
327 | dm_table_event(table); | |
328 | dm_table_put(table); | |
329 | } | |
330 | ||
1da177e4 LT |
331 | up_write(&_hash_lock); |
332 | kfree(old_name); | |
333 | return 0; | |
334 | } | |
335 | ||
336 | /*----------------------------------------------------------------- | |
337 | * Implementation of the ioctl commands | |
338 | *---------------------------------------------------------------*/ | |
339 | /* | |
340 | * All the ioctl commands get dispatched to functions with this | |
341 | * prototype. | |
342 | */ | |
343 | typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size); | |
344 | ||
345 | static int remove_all(struct dm_ioctl *param, size_t param_size) | |
346 | { | |
347 | dm_hash_remove_all(); | |
348 | param->data_size = 0; | |
349 | return 0; | |
350 | } | |
351 | ||
352 | /* | |
353 | * Round up the ptr to an 8-byte boundary. | |
354 | */ | |
355 | #define ALIGN_MASK 7 | |
356 | static inline void *align_ptr(void *ptr) | |
357 | { | |
358 | return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK); | |
359 | } | |
360 | ||
361 | /* | |
362 | * Retrieves the data payload buffer from an already allocated | |
363 | * struct dm_ioctl. | |
364 | */ | |
365 | static void *get_result_buffer(struct dm_ioctl *param, size_t param_size, | |
366 | size_t *len) | |
367 | { | |
368 | param->data_start = align_ptr(param + 1) - (void *) param; | |
369 | ||
370 | if (param->data_start < param_size) | |
371 | *len = param_size - param->data_start; | |
372 | else | |
373 | *len = 0; | |
374 | ||
375 | return ((void *) param) + param->data_start; | |
376 | } | |
377 | ||
378 | static int list_devices(struct dm_ioctl *param, size_t param_size) | |
379 | { | |
380 | unsigned int i; | |
381 | struct hash_cell *hc; | |
382 | size_t len, needed = 0; | |
383 | struct gendisk *disk; | |
384 | struct dm_name_list *nl, *old_nl = NULL; | |
385 | ||
386 | down_write(&_hash_lock); | |
387 | ||
388 | /* | |
389 | * Loop through all the devices working out how much | |
390 | * space we need. | |
391 | */ | |
392 | for (i = 0; i < NUM_BUCKETS; i++) { | |
393 | list_for_each_entry (hc, _name_buckets + i, name_list) { | |
394 | needed += sizeof(struct dm_name_list); | |
395 | needed += strlen(hc->name) + 1; | |
396 | needed += ALIGN_MASK; | |
397 | } | |
398 | } | |
399 | ||
400 | /* | |
401 | * Grab our output buffer. | |
402 | */ | |
403 | nl = get_result_buffer(param, param_size, &len); | |
404 | if (len < needed) { | |
405 | param->flags |= DM_BUFFER_FULL_FLAG; | |
406 | goto out; | |
407 | } | |
408 | param->data_size = param->data_start + needed; | |
409 | ||
410 | nl->dev = 0; /* Flags no data */ | |
411 | ||
412 | /* | |
413 | * Now loop through filling out the names. | |
414 | */ | |
415 | for (i = 0; i < NUM_BUCKETS; i++) { | |
416 | list_for_each_entry (hc, _name_buckets + i, name_list) { | |
417 | if (old_nl) | |
418 | old_nl->next = (uint32_t) ((void *) nl - | |
419 | (void *) old_nl); | |
420 | disk = dm_disk(hc->md); | |
421 | nl->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor)); | |
422 | nl->next = 0; | |
423 | strcpy(nl->name, hc->name); | |
424 | ||
425 | old_nl = nl; | |
426 | nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1); | |
427 | } | |
428 | } | |
429 | ||
430 | out: | |
431 | up_write(&_hash_lock); | |
432 | return 0; | |
433 | } | |
434 | ||
435 | static void list_version_get_needed(struct target_type *tt, void *needed_param) | |
436 | { | |
437 | size_t *needed = needed_param; | |
438 | ||
c4cc6635 | 439 | *needed += sizeof(struct dm_target_versions); |
1da177e4 | 440 | *needed += strlen(tt->name); |
1da177e4 LT |
441 | *needed += ALIGN_MASK; |
442 | } | |
443 | ||
444 | static void list_version_get_info(struct target_type *tt, void *param) | |
445 | { | |
446 | struct vers_iter *info = param; | |
447 | ||
448 | /* Check space - it might have changed since the first iteration */ | |
449 | if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 > | |
450 | info->end) { | |
451 | ||
452 | info->flags = DM_BUFFER_FULL_FLAG; | |
453 | return; | |
454 | } | |
455 | ||
456 | if (info->old_vers) | |
457 | info->old_vers->next = (uint32_t) ((void *)info->vers - | |
458 | (void *)info->old_vers); | |
459 | info->vers->version[0] = tt->version[0]; | |
460 | info->vers->version[1] = tt->version[1]; | |
461 | info->vers->version[2] = tt->version[2]; | |
462 | info->vers->next = 0; | |
463 | strcpy(info->vers->name, tt->name); | |
464 | ||
465 | info->old_vers = info->vers; | |
466 | info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1); | |
467 | } | |
468 | ||
469 | static int list_versions(struct dm_ioctl *param, size_t param_size) | |
470 | { | |
471 | size_t len, needed = 0; | |
472 | struct dm_target_versions *vers; | |
473 | struct vers_iter iter_info; | |
474 | ||
475 | /* | |
476 | * Loop through all the devices working out how much | |
477 | * space we need. | |
478 | */ | |
479 | dm_target_iterate(list_version_get_needed, &needed); | |
480 | ||
481 | /* | |
482 | * Grab our output buffer. | |
483 | */ | |
484 | vers = get_result_buffer(param, param_size, &len); | |
485 | if (len < needed) { | |
486 | param->flags |= DM_BUFFER_FULL_FLAG; | |
487 | goto out; | |
488 | } | |
489 | param->data_size = param->data_start + needed; | |
490 | ||
491 | iter_info.param_size = param_size; | |
492 | iter_info.old_vers = NULL; | |
493 | iter_info.vers = vers; | |
494 | iter_info.flags = 0; | |
495 | iter_info.end = (char *)vers+len; | |
496 | ||
497 | /* | |
498 | * Now loop through filling out the names & versions. | |
499 | */ | |
500 | dm_target_iterate(list_version_get_info, &iter_info); | |
501 | param->flags |= iter_info.flags; | |
502 | ||
503 | out: | |
504 | return 0; | |
505 | } | |
506 | ||
507 | ||
508 | ||
509 | static int check_name(const char *name) | |
510 | { | |
511 | if (strchr(name, '/')) { | |
512 | DMWARN("invalid device name"); | |
513 | return -EINVAL; | |
514 | } | |
515 | ||
516 | return 0; | |
517 | } | |
518 | ||
519 | /* | |
520 | * Fills in a dm_ioctl structure, ready for sending back to | |
521 | * userland. | |
522 | */ | |
523 | static int __dev_status(struct mapped_device *md, struct dm_ioctl *param) | |
524 | { | |
525 | struct gendisk *disk = dm_disk(md); | |
526 | struct dm_table *table; | |
527 | struct block_device *bdev; | |
528 | ||
529 | param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG | | |
530 | DM_ACTIVE_PRESENT_FLAG); | |
531 | ||
532 | if (dm_suspended(md)) | |
533 | param->flags |= DM_SUSPEND_FLAG; | |
534 | ||
535 | param->dev = huge_encode_dev(MKDEV(disk->major, disk->first_minor)); | |
536 | ||
537 | if (!(param->flags & DM_SKIP_BDGET_FLAG)) { | |
538 | bdev = bdget_disk(disk, 0); | |
539 | if (!bdev) | |
540 | return -ENXIO; | |
541 | ||
542 | /* | |
543 | * Yes, this will be out of date by the time it gets back | |
544 | * to userland, but it is still very useful for | |
545 | * debugging. | |
546 | */ | |
547 | param->open_count = bdev->bd_openers; | |
548 | bdput(bdev); | |
549 | } else | |
550 | param->open_count = -1; | |
551 | ||
552 | if (disk->policy) | |
553 | param->flags |= DM_READONLY_FLAG; | |
554 | ||
555 | param->event_nr = dm_get_event_nr(md); | |
556 | ||
557 | table = dm_get_table(md); | |
558 | if (table) { | |
559 | param->flags |= DM_ACTIVE_PRESENT_FLAG; | |
560 | param->target_count = dm_table_get_num_targets(table); | |
561 | dm_table_put(table); | |
562 | } else | |
563 | param->target_count = 0; | |
564 | ||
565 | return 0; | |
566 | } | |
567 | ||
568 | static int dev_create(struct dm_ioctl *param, size_t param_size) | |
569 | { | |
570 | int r; | |
571 | struct mapped_device *md; | |
572 | ||
573 | r = check_name(param->name); | |
574 | if (r) | |
575 | return r; | |
576 | ||
577 | if (param->flags & DM_PERSISTENT_DEV_FLAG) | |
578 | r = dm_create_with_minor(MINOR(huge_decode_dev(param->dev)), &md); | |
579 | else | |
580 | r = dm_create(&md); | |
581 | ||
582 | if (r) | |
583 | return r; | |
584 | ||
585 | r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md); | |
586 | if (r) { | |
587 | dm_put(md); | |
588 | return r; | |
589 | } | |
590 | ||
591 | param->flags &= ~DM_INACTIVE_PRESENT_FLAG; | |
592 | ||
593 | r = __dev_status(md, param); | |
594 | dm_put(md); | |
595 | ||
596 | return r; | |
597 | } | |
598 | ||
599 | /* | |
600 | * Always use UUID for lookups if it's present, otherwise use name or dev. | |
601 | */ | |
858119e1 | 602 | static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param) |
1da177e4 | 603 | { |
9ade92a9 AK |
604 | struct mapped_device *md; |
605 | void *mdptr = NULL; | |
606 | ||
1da177e4 LT |
607 | if (*param->uuid) |
608 | return __get_uuid_cell(param->uuid); | |
9ade92a9 AK |
609 | |
610 | if (*param->name) | |
1da177e4 | 611 | return __get_name_cell(param->name); |
9ade92a9 AK |
612 | |
613 | md = dm_get_md(huge_decode_dev(param->dev)); | |
614 | if (md) { | |
615 | mdptr = dm_get_mdptr(md); | |
616 | dm_put(md); | |
617 | } | |
618 | ||
619 | return mdptr; | |
1da177e4 LT |
620 | } |
621 | ||
858119e1 | 622 | static struct mapped_device *find_device(struct dm_ioctl *param) |
1da177e4 LT |
623 | { |
624 | struct hash_cell *hc; | |
625 | struct mapped_device *md = NULL; | |
626 | ||
627 | down_read(&_hash_lock); | |
628 | hc = __find_device_hash_cell(param); | |
629 | if (hc) { | |
630 | md = hc->md; | |
631 | dm_get(md); | |
632 | ||
633 | /* | |
634 | * Sneakily write in both the name and the uuid | |
635 | * while we have the cell. | |
636 | */ | |
637 | strncpy(param->name, hc->name, sizeof(param->name)); | |
638 | if (hc->uuid) | |
639 | strncpy(param->uuid, hc->uuid, sizeof(param->uuid)-1); | |
640 | else | |
641 | param->uuid[0] = '\0'; | |
642 | ||
643 | if (hc->new_map) | |
644 | param->flags |= DM_INACTIVE_PRESENT_FLAG; | |
645 | else | |
646 | param->flags &= ~DM_INACTIVE_PRESENT_FLAG; | |
647 | } | |
648 | up_read(&_hash_lock); | |
649 | ||
650 | return md; | |
651 | } | |
652 | ||
653 | static int dev_remove(struct dm_ioctl *param, size_t param_size) | |
654 | { | |
655 | struct hash_cell *hc; | |
656 | ||
657 | down_write(&_hash_lock); | |
658 | hc = __find_device_hash_cell(param); | |
659 | ||
660 | if (!hc) { | |
661 | DMWARN("device doesn't appear to be in the dev hash table."); | |
662 | up_write(&_hash_lock); | |
663 | return -ENXIO; | |
664 | } | |
665 | ||
666 | __hash_remove(hc); | |
667 | up_write(&_hash_lock); | |
668 | param->data_size = 0; | |
669 | return 0; | |
670 | } | |
671 | ||
672 | /* | |
673 | * Check a string doesn't overrun the chunk of | |
674 | * memory we copied from userland. | |
675 | */ | |
676 | static int invalid_str(char *str, void *end) | |
677 | { | |
678 | while ((void *) str < end) | |
679 | if (!*str++) | |
680 | return 0; | |
681 | ||
682 | return -EINVAL; | |
683 | } | |
684 | ||
685 | static int dev_rename(struct dm_ioctl *param, size_t param_size) | |
686 | { | |
687 | int r; | |
688 | char *new_name = (char *) param + param->data_start; | |
689 | ||
690 | if (new_name < (char *) (param + 1) || | |
691 | invalid_str(new_name, (void *) param + param_size)) { | |
692 | DMWARN("Invalid new logical volume name supplied."); | |
693 | return -EINVAL; | |
694 | } | |
695 | ||
696 | r = check_name(new_name); | |
697 | if (r) | |
698 | return r; | |
699 | ||
700 | param->data_size = 0; | |
701 | return dm_hash_rename(param->name, new_name); | |
702 | } | |
703 | ||
3ac51e74 DW |
704 | static int dev_set_geometry(struct dm_ioctl *param, size_t param_size) |
705 | { | |
706 | int r = -EINVAL, x; | |
707 | struct mapped_device *md; | |
708 | struct hd_geometry geometry; | |
709 | unsigned long indata[4]; | |
710 | char *geostr = (char *) param + param->data_start; | |
711 | ||
712 | md = find_device(param); | |
713 | if (!md) | |
714 | return -ENXIO; | |
715 | ||
716 | if (geostr < (char *) (param + 1) || | |
717 | invalid_str(geostr, (void *) param + param_size)) { | |
718 | DMWARN("Invalid geometry supplied."); | |
719 | goto out; | |
720 | } | |
721 | ||
722 | x = sscanf(geostr, "%lu %lu %lu %lu", indata, | |
723 | indata + 1, indata + 2, indata + 3); | |
724 | ||
725 | if (x != 4) { | |
726 | DMWARN("Unable to interpret geometry settings."); | |
727 | goto out; | |
728 | } | |
729 | ||
730 | if (indata[0] > 65535 || indata[1] > 255 || | |
731 | indata[2] > 255 || indata[3] > ULONG_MAX) { | |
732 | DMWARN("Geometry exceeds range limits."); | |
733 | goto out; | |
734 | } | |
735 | ||
736 | geometry.cylinders = indata[0]; | |
737 | geometry.heads = indata[1]; | |
738 | geometry.sectors = indata[2]; | |
739 | geometry.start = indata[3]; | |
740 | ||
741 | r = dm_set_geometry(md, &geometry); | |
742 | if (!r) | |
743 | r = __dev_status(md, param); | |
744 | ||
745 | param->data_size = 0; | |
746 | ||
747 | out: | |
748 | dm_put(md); | |
749 | return r; | |
750 | } | |
751 | ||
1da177e4 LT |
752 | static int do_suspend(struct dm_ioctl *param) |
753 | { | |
754 | int r = 0; | |
6da487dc | 755 | int do_lockfs = 1; |
1da177e4 LT |
756 | struct mapped_device *md; |
757 | ||
758 | md = find_device(param); | |
759 | if (!md) | |
760 | return -ENXIO; | |
761 | ||
6da487dc AK |
762 | if (param->flags & DM_SKIP_LOCKFS_FLAG) |
763 | do_lockfs = 0; | |
764 | ||
1da177e4 | 765 | if (!dm_suspended(md)) |
6da487dc | 766 | r = dm_suspend(md, do_lockfs); |
1da177e4 LT |
767 | |
768 | if (!r) | |
769 | r = __dev_status(md, param); | |
770 | ||
771 | dm_put(md); | |
772 | return r; | |
773 | } | |
774 | ||
775 | static int do_resume(struct dm_ioctl *param) | |
776 | { | |
777 | int r = 0; | |
6da487dc | 778 | int do_lockfs = 1; |
1da177e4 LT |
779 | struct hash_cell *hc; |
780 | struct mapped_device *md; | |
781 | struct dm_table *new_map; | |
782 | ||
783 | down_write(&_hash_lock); | |
784 | ||
785 | hc = __find_device_hash_cell(param); | |
786 | if (!hc) { | |
787 | DMWARN("device doesn't appear to be in the dev hash table."); | |
788 | up_write(&_hash_lock); | |
789 | return -ENXIO; | |
790 | } | |
791 | ||
792 | md = hc->md; | |
793 | dm_get(md); | |
794 | ||
795 | new_map = hc->new_map; | |
796 | hc->new_map = NULL; | |
797 | param->flags &= ~DM_INACTIVE_PRESENT_FLAG; | |
798 | ||
799 | up_write(&_hash_lock); | |
800 | ||
801 | /* Do we need to load a new map ? */ | |
802 | if (new_map) { | |
803 | /* Suspend if it isn't already suspended */ | |
6da487dc AK |
804 | if (param->flags & DM_SKIP_LOCKFS_FLAG) |
805 | do_lockfs = 0; | |
1da177e4 | 806 | if (!dm_suspended(md)) |
6da487dc | 807 | dm_suspend(md, do_lockfs); |
1da177e4 LT |
808 | |
809 | r = dm_swap_table(md, new_map); | |
810 | if (r) { | |
811 | dm_put(md); | |
812 | dm_table_put(new_map); | |
813 | return r; | |
814 | } | |
815 | ||
816 | if (dm_table_get_mode(new_map) & FMODE_WRITE) | |
817 | set_disk_ro(dm_disk(md), 0); | |
818 | else | |
819 | set_disk_ro(dm_disk(md), 1); | |
820 | ||
821 | dm_table_put(new_map); | |
822 | } | |
823 | ||
824 | if (dm_suspended(md)) | |
825 | r = dm_resume(md); | |
826 | ||
827 | if (!r) | |
828 | r = __dev_status(md, param); | |
829 | ||
830 | dm_put(md); | |
831 | return r; | |
832 | } | |
833 | ||
834 | /* | |
835 | * Set or unset the suspension state of a device. | |
836 | * If the device already is in the requested state we just return its status. | |
837 | */ | |
838 | static int dev_suspend(struct dm_ioctl *param, size_t param_size) | |
839 | { | |
840 | if (param->flags & DM_SUSPEND_FLAG) | |
841 | return do_suspend(param); | |
842 | ||
843 | return do_resume(param); | |
844 | } | |
845 | ||
846 | /* | |
847 | * Copies device info back to user space, used by | |
848 | * the create and info ioctls. | |
849 | */ | |
850 | static int dev_status(struct dm_ioctl *param, size_t param_size) | |
851 | { | |
852 | int r; | |
853 | struct mapped_device *md; | |
854 | ||
855 | md = find_device(param); | |
856 | if (!md) | |
857 | return -ENXIO; | |
858 | ||
859 | r = __dev_status(md, param); | |
860 | dm_put(md); | |
861 | return r; | |
862 | } | |
863 | ||
864 | /* | |
865 | * Build up the status struct for each target | |
866 | */ | |
867 | static void retrieve_status(struct dm_table *table, | |
868 | struct dm_ioctl *param, size_t param_size) | |
869 | { | |
870 | unsigned int i, num_targets; | |
871 | struct dm_target_spec *spec; | |
872 | char *outbuf, *outptr; | |
873 | status_type_t type; | |
874 | size_t remaining, len, used = 0; | |
875 | ||
876 | outptr = outbuf = get_result_buffer(param, param_size, &len); | |
877 | ||
878 | if (param->flags & DM_STATUS_TABLE_FLAG) | |
879 | type = STATUSTYPE_TABLE; | |
880 | else | |
881 | type = STATUSTYPE_INFO; | |
882 | ||
883 | /* Get all the target info */ | |
884 | num_targets = dm_table_get_num_targets(table); | |
885 | for (i = 0; i < num_targets; i++) { | |
886 | struct dm_target *ti = dm_table_get_target(table, i); | |
887 | ||
888 | remaining = len - (outptr - outbuf); | |
889 | if (remaining <= sizeof(struct dm_target_spec)) { | |
890 | param->flags |= DM_BUFFER_FULL_FLAG; | |
891 | break; | |
892 | } | |
893 | ||
894 | spec = (struct dm_target_spec *) outptr; | |
895 | ||
896 | spec->status = 0; | |
897 | spec->sector_start = ti->begin; | |
898 | spec->length = ti->len; | |
899 | strncpy(spec->target_type, ti->type->name, | |
900 | sizeof(spec->target_type)); | |
901 | ||
902 | outptr += sizeof(struct dm_target_spec); | |
903 | remaining = len - (outptr - outbuf); | |
904 | if (remaining <= 0) { | |
905 | param->flags |= DM_BUFFER_FULL_FLAG; | |
906 | break; | |
907 | } | |
908 | ||
909 | /* Get the status/table string from the target driver */ | |
910 | if (ti->type->status) { | |
911 | if (ti->type->status(ti, type, outptr, remaining)) { | |
912 | param->flags |= DM_BUFFER_FULL_FLAG; | |
913 | break; | |
914 | } | |
915 | } else | |
916 | outptr[0] = '\0'; | |
917 | ||
918 | outptr += strlen(outptr) + 1; | |
919 | used = param->data_start + (outptr - outbuf); | |
920 | ||
921 | outptr = align_ptr(outptr); | |
922 | spec->next = outptr - outbuf; | |
923 | } | |
924 | ||
925 | if (used) | |
926 | param->data_size = used; | |
927 | ||
928 | param->target_count = num_targets; | |
929 | } | |
930 | ||
931 | /* | |
932 | * Wait for a device to report an event | |
933 | */ | |
934 | static int dev_wait(struct dm_ioctl *param, size_t param_size) | |
935 | { | |
936 | int r; | |
937 | struct mapped_device *md; | |
938 | struct dm_table *table; | |
939 | ||
940 | md = find_device(param); | |
941 | if (!md) | |
942 | return -ENXIO; | |
943 | ||
944 | /* | |
945 | * Wait for a notification event | |
946 | */ | |
947 | if (dm_wait_event(md, param->event_nr)) { | |
948 | r = -ERESTARTSYS; | |
949 | goto out; | |
950 | } | |
951 | ||
952 | /* | |
953 | * The userland program is going to want to know what | |
954 | * changed to trigger the event, so we may as well tell | |
955 | * him and save an ioctl. | |
956 | */ | |
957 | r = __dev_status(md, param); | |
958 | if (r) | |
959 | goto out; | |
960 | ||
961 | table = dm_get_table(md); | |
962 | if (table) { | |
963 | retrieve_status(table, param, param_size); | |
964 | dm_table_put(table); | |
965 | } | |
966 | ||
967 | out: | |
968 | dm_put(md); | |
969 | return r; | |
970 | } | |
971 | ||
972 | static inline int get_mode(struct dm_ioctl *param) | |
973 | { | |
974 | int mode = FMODE_READ | FMODE_WRITE; | |
975 | ||
976 | if (param->flags & DM_READONLY_FLAG) | |
977 | mode = FMODE_READ; | |
978 | ||
979 | return mode; | |
980 | } | |
981 | ||
982 | static int next_target(struct dm_target_spec *last, uint32_t next, void *end, | |
983 | struct dm_target_spec **spec, char **target_params) | |
984 | { | |
985 | *spec = (struct dm_target_spec *) ((unsigned char *) last + next); | |
986 | *target_params = (char *) (*spec + 1); | |
987 | ||
988 | if (*spec < (last + 1)) | |
989 | return -EINVAL; | |
990 | ||
991 | return invalid_str(*target_params, end); | |
992 | } | |
993 | ||
994 | static int populate_table(struct dm_table *table, | |
995 | struct dm_ioctl *param, size_t param_size) | |
996 | { | |
997 | int r; | |
998 | unsigned int i = 0; | |
999 | struct dm_target_spec *spec = (struct dm_target_spec *) param; | |
1000 | uint32_t next = param->data_start; | |
1001 | void *end = (void *) param + param_size; | |
1002 | char *target_params; | |
1003 | ||
1004 | if (!param->target_count) { | |
1005 | DMWARN("populate_table: no targets specified"); | |
1006 | return -EINVAL; | |
1007 | } | |
1008 | ||
1009 | for (i = 0; i < param->target_count; i++) { | |
1010 | ||
1011 | r = next_target(spec, next, end, &spec, &target_params); | |
1012 | if (r) { | |
1013 | DMWARN("unable to find target"); | |
1014 | return r; | |
1015 | } | |
1016 | ||
1017 | r = dm_table_add_target(table, spec->target_type, | |
1018 | (sector_t) spec->sector_start, | |
1019 | (sector_t) spec->length, | |
1020 | target_params); | |
1021 | if (r) { | |
1022 | DMWARN("error adding target to table"); | |
1023 | return r; | |
1024 | } | |
1025 | ||
1026 | next = spec->next; | |
1027 | } | |
1028 | ||
1029 | return dm_table_complete(table); | |
1030 | } | |
1031 | ||
1032 | static int table_load(struct dm_ioctl *param, size_t param_size) | |
1033 | { | |
1034 | int r; | |
1035 | struct hash_cell *hc; | |
1036 | struct dm_table *t; | |
1134e5ae MA |
1037 | struct mapped_device *md; |
1038 | ||
1039 | md = find_device(param); | |
1040 | if (!md) | |
1041 | return -ENXIO; | |
1da177e4 | 1042 | |
1134e5ae | 1043 | r = dm_table_create(&t, get_mode(param), param->target_count, md); |
1da177e4 | 1044 | if (r) |
1134e5ae | 1045 | goto out; |
1da177e4 LT |
1046 | |
1047 | r = populate_table(t, param, param_size); | |
1048 | if (r) { | |
1049 | dm_table_put(t); | |
1134e5ae | 1050 | goto out; |
1da177e4 LT |
1051 | } |
1052 | ||
1053 | down_write(&_hash_lock); | |
1134e5ae MA |
1054 | hc = dm_get_mdptr(md); |
1055 | if (!hc || hc->md != md) { | |
1056 | DMWARN("device has been removed from the dev hash table."); | |
b6fcc80d | 1057 | dm_table_put(t); |
1134e5ae MA |
1058 | up_write(&_hash_lock); |
1059 | r = -ENXIO; | |
1060 | goto out; | |
1da177e4 LT |
1061 | } |
1062 | ||
1063 | if (hc->new_map) | |
1064 | dm_table_put(hc->new_map); | |
1065 | hc->new_map = t; | |
1134e5ae MA |
1066 | up_write(&_hash_lock); |
1067 | ||
1da177e4 | 1068 | param->flags |= DM_INACTIVE_PRESENT_FLAG; |
1134e5ae MA |
1069 | r = __dev_status(md, param); |
1070 | ||
1071 | out: | |
1072 | dm_put(md); | |
1da177e4 | 1073 | |
1da177e4 LT |
1074 | return r; |
1075 | } | |
1076 | ||
1077 | static int table_clear(struct dm_ioctl *param, size_t param_size) | |
1078 | { | |
1079 | int r; | |
1080 | struct hash_cell *hc; | |
1081 | ||
1082 | down_write(&_hash_lock); | |
1083 | ||
1084 | hc = __find_device_hash_cell(param); | |
1085 | if (!hc) { | |
1086 | DMWARN("device doesn't appear to be in the dev hash table."); | |
1087 | up_write(&_hash_lock); | |
1088 | return -ENXIO; | |
1089 | } | |
1090 | ||
1091 | if (hc->new_map) { | |
1092 | dm_table_put(hc->new_map); | |
1093 | hc->new_map = NULL; | |
1094 | } | |
1095 | ||
1096 | param->flags &= ~DM_INACTIVE_PRESENT_FLAG; | |
1097 | ||
1098 | r = __dev_status(hc->md, param); | |
1099 | up_write(&_hash_lock); | |
1100 | return r; | |
1101 | } | |
1102 | ||
1103 | /* | |
1104 | * Retrieves a list of devices used by a particular dm device. | |
1105 | */ | |
1106 | static void retrieve_deps(struct dm_table *table, | |
1107 | struct dm_ioctl *param, size_t param_size) | |
1108 | { | |
1109 | unsigned int count = 0; | |
1110 | struct list_head *tmp; | |
1111 | size_t len, needed; | |
1112 | struct dm_dev *dd; | |
1113 | struct dm_target_deps *deps; | |
1114 | ||
1115 | deps = get_result_buffer(param, param_size, &len); | |
1116 | ||
1117 | /* | |
1118 | * Count the devices. | |
1119 | */ | |
1120 | list_for_each (tmp, dm_table_get_devices(table)) | |
1121 | count++; | |
1122 | ||
1123 | /* | |
1124 | * Check we have enough space. | |
1125 | */ | |
1126 | needed = sizeof(*deps) + (sizeof(*deps->dev) * count); | |
1127 | if (len < needed) { | |
1128 | param->flags |= DM_BUFFER_FULL_FLAG; | |
1129 | return; | |
1130 | } | |
1131 | ||
1132 | /* | |
1133 | * Fill in the devices. | |
1134 | */ | |
1135 | deps->count = count; | |
1136 | count = 0; | |
1137 | list_for_each_entry (dd, dm_table_get_devices(table), list) | |
1138 | deps->dev[count++] = huge_encode_dev(dd->bdev->bd_dev); | |
1139 | ||
1140 | param->data_size = param->data_start + needed; | |
1141 | } | |
1142 | ||
1143 | static int table_deps(struct dm_ioctl *param, size_t param_size) | |
1144 | { | |
1145 | int r = 0; | |
1146 | struct mapped_device *md; | |
1147 | struct dm_table *table; | |
1148 | ||
1149 | md = find_device(param); | |
1150 | if (!md) | |
1151 | return -ENXIO; | |
1152 | ||
1153 | r = __dev_status(md, param); | |
1154 | if (r) | |
1155 | goto out; | |
1156 | ||
1157 | table = dm_get_table(md); | |
1158 | if (table) { | |
1159 | retrieve_deps(table, param, param_size); | |
1160 | dm_table_put(table); | |
1161 | } | |
1162 | ||
1163 | out: | |
1164 | dm_put(md); | |
1165 | return r; | |
1166 | } | |
1167 | ||
1168 | /* | |
1169 | * Return the status of a device as a text string for each | |
1170 | * target. | |
1171 | */ | |
1172 | static int table_status(struct dm_ioctl *param, size_t param_size) | |
1173 | { | |
1174 | int r; | |
1175 | struct mapped_device *md; | |
1176 | struct dm_table *table; | |
1177 | ||
1178 | md = find_device(param); | |
1179 | if (!md) | |
1180 | return -ENXIO; | |
1181 | ||
1182 | r = __dev_status(md, param); | |
1183 | if (r) | |
1184 | goto out; | |
1185 | ||
1186 | table = dm_get_table(md); | |
1187 | if (table) { | |
1188 | retrieve_status(table, param, param_size); | |
1189 | dm_table_put(table); | |
1190 | } | |
1191 | ||
1192 | out: | |
1193 | dm_put(md); | |
1194 | return r; | |
1195 | } | |
1196 | ||
1197 | /* | |
1198 | * Pass a message to the target that's at the supplied device offset. | |
1199 | */ | |
1200 | static int target_message(struct dm_ioctl *param, size_t param_size) | |
1201 | { | |
1202 | int r, argc; | |
1203 | char **argv; | |
1204 | struct mapped_device *md; | |
1205 | struct dm_table *table; | |
1206 | struct dm_target *ti; | |
1207 | struct dm_target_msg *tmsg = (void *) param + param->data_start; | |
1208 | ||
1209 | md = find_device(param); | |
1210 | if (!md) | |
1211 | return -ENXIO; | |
1212 | ||
1213 | r = __dev_status(md, param); | |
1214 | if (r) | |
1215 | goto out; | |
1216 | ||
1217 | if (tmsg < (struct dm_target_msg *) (param + 1) || | |
1218 | invalid_str(tmsg->message, (void *) param + param_size)) { | |
1219 | DMWARN("Invalid target message parameters."); | |
1220 | r = -EINVAL; | |
1221 | goto out; | |
1222 | } | |
1223 | ||
1224 | r = dm_split_args(&argc, &argv, tmsg->message); | |
1225 | if (r) { | |
1226 | DMWARN("Failed to split target message parameters"); | |
1227 | goto out; | |
1228 | } | |
1229 | ||
1230 | table = dm_get_table(md); | |
1231 | if (!table) | |
1232 | goto out_argv; | |
1233 | ||
1234 | if (tmsg->sector >= dm_table_get_size(table)) { | |
1235 | DMWARN("Target message sector outside device."); | |
1236 | r = -EINVAL; | |
1237 | goto out_table; | |
1238 | } | |
1239 | ||
1240 | ti = dm_table_find_target(table, tmsg->sector); | |
1241 | if (ti->type->message) | |
1242 | r = ti->type->message(ti, argc, argv); | |
1243 | else { | |
1244 | DMWARN("Target type does not support messages"); | |
1245 | r = -EINVAL; | |
1246 | } | |
1247 | ||
1248 | out_table: | |
1249 | dm_table_put(table); | |
1250 | out_argv: | |
1251 | kfree(argv); | |
1252 | out: | |
1253 | param->data_size = 0; | |
1254 | dm_put(md); | |
1255 | return r; | |
1256 | } | |
1257 | ||
1258 | /*----------------------------------------------------------------- | |
1259 | * Implementation of open/close/ioctl on the special char | |
1260 | * device. | |
1261 | *---------------------------------------------------------------*/ | |
1262 | static ioctl_fn lookup_ioctl(unsigned int cmd) | |
1263 | { | |
1264 | static struct { | |
1265 | int cmd; | |
1266 | ioctl_fn fn; | |
1267 | } _ioctls[] = { | |
1268 | {DM_VERSION_CMD, NULL}, /* version is dealt with elsewhere */ | |
1269 | {DM_REMOVE_ALL_CMD, remove_all}, | |
1270 | {DM_LIST_DEVICES_CMD, list_devices}, | |
1271 | ||
1272 | {DM_DEV_CREATE_CMD, dev_create}, | |
1273 | {DM_DEV_REMOVE_CMD, dev_remove}, | |
1274 | {DM_DEV_RENAME_CMD, dev_rename}, | |
1275 | {DM_DEV_SUSPEND_CMD, dev_suspend}, | |
1276 | {DM_DEV_STATUS_CMD, dev_status}, | |
1277 | {DM_DEV_WAIT_CMD, dev_wait}, | |
1278 | ||
1279 | {DM_TABLE_LOAD_CMD, table_load}, | |
1280 | {DM_TABLE_CLEAR_CMD, table_clear}, | |
1281 | {DM_TABLE_DEPS_CMD, table_deps}, | |
1282 | {DM_TABLE_STATUS_CMD, table_status}, | |
1283 | ||
1284 | {DM_LIST_VERSIONS_CMD, list_versions}, | |
1285 | ||
3ac51e74 DW |
1286 | {DM_TARGET_MSG_CMD, target_message}, |
1287 | {DM_DEV_SET_GEOMETRY_CMD, dev_set_geometry} | |
1da177e4 LT |
1288 | }; |
1289 | ||
1290 | return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn; | |
1291 | } | |
1292 | ||
1293 | /* | |
1294 | * As well as checking the version compatibility this always | |
1295 | * copies the kernel interface version out. | |
1296 | */ | |
1297 | static int check_version(unsigned int cmd, struct dm_ioctl __user *user) | |
1298 | { | |
1299 | uint32_t version[3]; | |
1300 | int r = 0; | |
1301 | ||
1302 | if (copy_from_user(version, user->version, sizeof(version))) | |
1303 | return -EFAULT; | |
1304 | ||
1305 | if ((DM_VERSION_MAJOR != version[0]) || | |
1306 | (DM_VERSION_MINOR < version[1])) { | |
1307 | DMWARN("ioctl interface mismatch: " | |
1308 | "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)", | |
1309 | DM_VERSION_MAJOR, DM_VERSION_MINOR, | |
1310 | DM_VERSION_PATCHLEVEL, | |
1311 | version[0], version[1], version[2], cmd); | |
1312 | r = -EINVAL; | |
1313 | } | |
1314 | ||
1315 | /* | |
1316 | * Fill in the kernel version. | |
1317 | */ | |
1318 | version[0] = DM_VERSION_MAJOR; | |
1319 | version[1] = DM_VERSION_MINOR; | |
1320 | version[2] = DM_VERSION_PATCHLEVEL; | |
1321 | if (copy_to_user(user->version, version, sizeof(version))) | |
1322 | return -EFAULT; | |
1323 | ||
1324 | return r; | |
1325 | } | |
1326 | ||
1327 | static void free_params(struct dm_ioctl *param) | |
1328 | { | |
1329 | vfree(param); | |
1330 | } | |
1331 | ||
1332 | static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param) | |
1333 | { | |
1334 | struct dm_ioctl tmp, *dmi; | |
1335 | ||
1336 | if (copy_from_user(&tmp, user, sizeof(tmp))) | |
1337 | return -EFAULT; | |
1338 | ||
1339 | if (tmp.data_size < sizeof(tmp)) | |
1340 | return -EINVAL; | |
1341 | ||
1342 | dmi = (struct dm_ioctl *) vmalloc(tmp.data_size); | |
1343 | if (!dmi) | |
1344 | return -ENOMEM; | |
1345 | ||
1346 | if (copy_from_user(dmi, user, tmp.data_size)) { | |
1347 | vfree(dmi); | |
1348 | return -EFAULT; | |
1349 | } | |
1350 | ||
1351 | *param = dmi; | |
1352 | return 0; | |
1353 | } | |
1354 | ||
1355 | static int validate_params(uint cmd, struct dm_ioctl *param) | |
1356 | { | |
1357 | /* Always clear this flag */ | |
1358 | param->flags &= ~DM_BUFFER_FULL_FLAG; | |
1359 | ||
1360 | /* Ignores parameters */ | |
1361 | if (cmd == DM_REMOVE_ALL_CMD || | |
1362 | cmd == DM_LIST_DEVICES_CMD || | |
1363 | cmd == DM_LIST_VERSIONS_CMD) | |
1364 | return 0; | |
1365 | ||
1366 | if ((cmd == DM_DEV_CREATE_CMD)) { | |
1367 | if (!*param->name) { | |
1368 | DMWARN("name not supplied when creating device"); | |
1369 | return -EINVAL; | |
1370 | } | |
1371 | } else if ((*param->uuid && *param->name)) { | |
1372 | DMWARN("only supply one of name or uuid, cmd(%u)", cmd); | |
1373 | return -EINVAL; | |
1374 | } | |
1375 | ||
1376 | /* Ensure strings are terminated */ | |
1377 | param->name[DM_NAME_LEN - 1] = '\0'; | |
1378 | param->uuid[DM_UUID_LEN - 1] = '\0'; | |
1379 | ||
1380 | return 0; | |
1381 | } | |
1382 | ||
1383 | static int ctl_ioctl(struct inode *inode, struct file *file, | |
1384 | uint command, ulong u) | |
1385 | { | |
1386 | int r = 0; | |
1387 | unsigned int cmd; | |
1388 | struct dm_ioctl *param; | |
1389 | struct dm_ioctl __user *user = (struct dm_ioctl __user *) u; | |
1390 | ioctl_fn fn = NULL; | |
1391 | size_t param_size; | |
1392 | ||
1393 | /* only root can play with this */ | |
1394 | if (!capable(CAP_SYS_ADMIN)) | |
1395 | return -EACCES; | |
1396 | ||
1397 | if (_IOC_TYPE(command) != DM_IOCTL) | |
1398 | return -ENOTTY; | |
1399 | ||
1400 | cmd = _IOC_NR(command); | |
1401 | ||
1402 | /* | |
1403 | * Check the interface version passed in. This also | |
1404 | * writes out the kernel's interface version. | |
1405 | */ | |
1406 | r = check_version(cmd, user); | |
1407 | if (r) | |
1408 | return r; | |
1409 | ||
1410 | /* | |
1411 | * Nothing more to do for the version command. | |
1412 | */ | |
1413 | if (cmd == DM_VERSION_CMD) | |
1414 | return 0; | |
1415 | ||
1416 | fn = lookup_ioctl(cmd); | |
1417 | if (!fn) { | |
1418 | DMWARN("dm_ctl_ioctl: unknown command 0x%x", command); | |
1419 | return -ENOTTY; | |
1420 | } | |
1421 | ||
1422 | /* | |
1423 | * Trying to avoid low memory issues when a device is | |
1424 | * suspended. | |
1425 | */ | |
1426 | current->flags |= PF_MEMALLOC; | |
1427 | ||
1428 | /* | |
1429 | * Copy the parameters into kernel space. | |
1430 | */ | |
1431 | r = copy_params(user, ¶m); | |
1da177e4 | 1432 | |
dab6a429 AK |
1433 | current->flags &= ~PF_MEMALLOC; |
1434 | ||
1435 | if (r) | |
1436 | return r; | |
1da177e4 LT |
1437 | |
1438 | r = validate_params(cmd, param); | |
1439 | if (r) | |
1440 | goto out; | |
1441 | ||
1442 | param_size = param->data_size; | |
1443 | param->data_size = sizeof(*param); | |
1444 | r = fn(param, param_size); | |
1445 | ||
1446 | /* | |
1447 | * Copy the results back to userland. | |
1448 | */ | |
1449 | if (!r && copy_to_user(user, param, param->data_size)) | |
1450 | r = -EFAULT; | |
1451 | ||
1452 | out: | |
1453 | free_params(param); | |
1da177e4 LT |
1454 | return r; |
1455 | } | |
1456 | ||
1457 | static struct file_operations _ctl_fops = { | |
1458 | .ioctl = ctl_ioctl, | |
1459 | .owner = THIS_MODULE, | |
1460 | }; | |
1461 | ||
1462 | static struct miscdevice _dm_misc = { | |
1463 | .minor = MISC_DYNAMIC_MINOR, | |
1464 | .name = DM_NAME, | |
1465 | .devfs_name = "mapper/control", | |
1466 | .fops = &_ctl_fops | |
1467 | }; | |
1468 | ||
1469 | /* | |
1470 | * Create misc character device and link to DM_DIR/control. | |
1471 | */ | |
1472 | int __init dm_interface_init(void) | |
1473 | { | |
1474 | int r; | |
1475 | ||
1476 | r = dm_hash_init(); | |
1477 | if (r) | |
1478 | return r; | |
1479 | ||
1480 | r = misc_register(&_dm_misc); | |
1481 | if (r) { | |
1482 | DMERR("misc_register failed for control device"); | |
1483 | dm_hash_exit(); | |
1484 | return r; | |
1485 | } | |
1486 | ||
1487 | DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR, | |
1488 | DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA, | |
1489 | DM_DRIVER_EMAIL); | |
1490 | return 0; | |
1491 | } | |
1492 | ||
1493 | void dm_interface_exit(void) | |
1494 | { | |
1495 | if (misc_deregister(&_dm_misc) < 0) | |
1496 | DMERR("misc_deregister failed for control device"); | |
1497 | ||
1498 | dm_hash_exit(); | |
1499 | } |