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