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