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This client driver allows you to use a GPIO pin as a source for PPS
[linux-2.6/next.git] / drivers / md / dm-ioctl.c
blob2e9a3ca37bdd39c6cbaf36f800b77aa3a04a638f
1 /*
2 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
3 * Copyright (C) 2004 - 2006 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/dm-ioctl.h>
17 #include <linux/hdreg.h>
18 #include <linux/compat.h>
19
20 #include <asm/uaccess.h>
21
22 #define DM_MSG_PREFIX "ioctl"
23 #define DM_DRIVER_EMAIL "dm-devel@redhat.com"
24
25 /*-----------------------------------------------------------------
26 * The ioctl interface needs to be able to look up devices by
27 * name or uuid.
28 *---------------------------------------------------------------*/
29 struct hash_cell {
30 struct list_head name_list;
31 struct list_head uuid_list;
32
33 char *name;
34 char *uuid;
35 struct mapped_device *md;
36 struct dm_table *new_map;
37 };
38
39 struct vers_iter {
40 size_t param_size;
41 struct dm_target_versions *vers, *old_vers;
42 char *end;
43 uint32_t flags;
44 };
45
46
47 #define NUM_BUCKETS 64
48 #define MASK_BUCKETS (NUM_BUCKETS - 1)
49 static struct list_head _name_buckets[NUM_BUCKETS];
50 static struct list_head _uuid_buckets[NUM_BUCKETS];
51
52 static void dm_hash_remove_all(int keep_open_devices);
53
54 /*
55 * Guards access to both hash tables.
56 */
57 static DECLARE_RWSEM(_hash_lock);
58
59 /*
60 * Protects use of mdptr to obtain hash cell name and uuid from mapped device.
61 */
62 static DEFINE_MUTEX(dm_hash_cells_mutex);
63
64 static void init_buckets(struct list_head *buckets)
65 {
66 unsigned int i;
67
68 for (i = 0; i < NUM_BUCKETS; i++)
69 INIT_LIST_HEAD(buckets + i);
70 }
71
72 static int dm_hash_init(void)
73 {
74 init_buckets(_name_buckets);
75 init_buckets(_uuid_buckets);
76 return 0;
77 }
78
79 static void dm_hash_exit(void)
80 {
81 dm_hash_remove_all(0);
82 }
83
84 /*-----------------------------------------------------------------
85 * Hash function:
86 * We're not really concerned with the str hash function being
87 * fast since it's only used by the ioctl interface.
88 *---------------------------------------------------------------*/
89 static unsigned int hash_str(const char *str)
90 {
91 const unsigned int hash_mult = 2654435387U;
92 unsigned int h = 0;
93
94 while (*str)
95 h = (h + (unsigned int) *str++) * hash_mult;
96
97 return h & MASK_BUCKETS;
98 }
99
100 /*-----------------------------------------------------------------
101 * Code for looking up a device by name
102 *---------------------------------------------------------------*/
103 static struct hash_cell *__get_name_cell(const char *str)
104 {
105 struct hash_cell *hc;
106 unsigned int h = hash_str(str);
107
108 list_for_each_entry (hc, _name_buckets + h, name_list)
109 if (!strcmp(hc->name, str)) {
110 dm_get(hc->md);
111 return hc;
112 }
113
114 return NULL;
115 }
116
117 static struct hash_cell *__get_uuid_cell(const char *str)
118 {
119 struct hash_cell *hc;
120 unsigned int h = hash_str(str);
121
122 list_for_each_entry (hc, _uuid_buckets + h, uuid_list)
123 if (!strcmp(hc->uuid, str)) {
124 dm_get(hc->md);
125 return hc;
126 }
127
128 return NULL;
129 }
130
131 static struct hash_cell *__get_dev_cell(uint64_t dev)
132 {
133 struct mapped_device *md;
134 struct hash_cell *hc;
135
136 md = dm_get_md(huge_decode_dev(dev));
137 if (!md)
138 return NULL;
139
140 hc = dm_get_mdptr(md);
141 if (!hc) {
142 dm_put(md);
143 return NULL;
144 }
145
146 return hc;
147 }
148
149 /*-----------------------------------------------------------------
150 * Inserting, removing and renaming a device.
151 *---------------------------------------------------------------*/
152 static struct hash_cell *alloc_cell(const char *name, const char *uuid,
153 struct mapped_device *md)
154 {
155 struct hash_cell *hc;
156
157 hc = kmalloc(sizeof(*hc), GFP_KERNEL);
158 if (!hc)
159 return NULL;
160
161 hc->name = kstrdup(name, GFP_KERNEL);
162 if (!hc->name) {
163 kfree(hc);
164 return NULL;
165 }
166
167 if (!uuid)
168 hc->uuid = NULL;
169
170 else {
171 hc->uuid = kstrdup(uuid, GFP_KERNEL);
172 if (!hc->uuid) {
173 kfree(hc->name);
174 kfree(hc);
175 return NULL;
176 }
177 }
178
179 INIT_LIST_HEAD(&hc->name_list);
180 INIT_LIST_HEAD(&hc->uuid_list);
181 hc->md = md;
182 hc->new_map = NULL;
183 return hc;
184 }
185
186 static void free_cell(struct hash_cell *hc)
187 {
188 if (hc) {
189 kfree(hc->name);
190 kfree(hc->uuid);
191 kfree(hc);
192 }
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, *hc;
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 hc = __get_name_cell(name);
215 if (hc) {
216 dm_put(hc->md);
217 goto bad;
218 }
219
220 list_add(&cell->name_list, _name_buckets + hash_str(name));
221
222 if (uuid) {
223 hc = __get_uuid_cell(uuid);
224 if (hc) {
225 list_del(&cell->name_list);
226 dm_put(hc->md);
227 goto bad;
228 }
229 list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
230 }
231 dm_get(md);
232 mutex_lock(&dm_hash_cells_mutex);
233 dm_set_mdptr(md, cell);
234 mutex_unlock(&dm_hash_cells_mutex);
235 up_write(&_hash_lock);
236
237 return 0;
238
239 bad:
240 up_write(&_hash_lock);
241 free_cell(cell);
242 return -EBUSY;
243 }
244
245 static void __hash_remove(struct hash_cell *hc)
246 {
247 struct dm_table *table;
248
249 /* remove from the dev hash */
250 list_del(&hc->uuid_list);
251 list_del(&hc->name_list);
252 mutex_lock(&dm_hash_cells_mutex);
253 dm_set_mdptr(hc->md, NULL);
254 mutex_unlock(&dm_hash_cells_mutex);
255
256 table = dm_get_live_table(hc->md);
257 if (table) {
258 dm_table_event(table);
259 dm_table_put(table);
260 }
261
262 if (hc->new_map)
263 dm_table_destroy(hc->new_map);
264 dm_put(hc->md);
265 free_cell(hc);
266 }
267
268 static void dm_hash_remove_all(int keep_open_devices)
269 {
270 int i, dev_skipped;
271 struct hash_cell *hc;
272 struct mapped_device *md;
273
274 retry:
275 dev_skipped = 0;
276
277 down_write(&_hash_lock);
278
279 for (i = 0; i < NUM_BUCKETS; i++) {
280 list_for_each_entry(hc, _name_buckets + i, name_list) {
281 md = hc->md;
282 dm_get(md);
283
284 if (keep_open_devices && dm_lock_for_deletion(md)) {
285 dm_put(md);
286 dev_skipped++;
287 continue;
288 }
289
290 __hash_remove(hc);
291
292 up_write(&_hash_lock);
293
294 dm_put(md);
295 if (likely(keep_open_devices))
296 dm_destroy(md);
297 else
298 dm_destroy_immediate(md);
299
300 /*
301 * Some mapped devices may be using other mapped
302 * devices, so repeat until we make no further
303 * progress. If a new mapped device is created
304 * here it will also get removed.
305 */
306 goto retry;
307 }
308 }
309
310 up_write(&_hash_lock);
311
312 if (dev_skipped)
313 DMWARN("remove_all left %d open device(s)", dev_skipped);
314 }
315
316 /*
317 * Set the uuid of a hash_cell that isn't already set.
318 */
319 static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
320 {
321 mutex_lock(&dm_hash_cells_mutex);
322 hc->uuid = new_uuid;
323 mutex_unlock(&dm_hash_cells_mutex);
324
325 list_add(&hc->uuid_list, _uuid_buckets + hash_str(new_uuid));
326 }
327
328 /*
329 * Changes the name of a hash_cell and returns the old name for
330 * the caller to free.
331 */
332 static char *__change_cell_name(struct hash_cell *hc, char *new_name)
333 {
334 char *old_name;
335
336 /*
337 * Rename and move the name cell.
338 */
339 list_del(&hc->name_list);
340 old_name = hc->name;
341
342 mutex_lock(&dm_hash_cells_mutex);
343 hc->name = new_name;
344 mutex_unlock(&dm_hash_cells_mutex);
345
346 list_add(&hc->name_list, _name_buckets + hash_str(new_name));
347
348 return old_name;
349 }
350
351 static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
352 const char *new)
353 {
354 char *new_data, *old_name = NULL;
355 struct hash_cell *hc;
356 struct dm_table *table;
357 struct mapped_device *md;
358 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
359
360 /*
361 * duplicate new.
362 */
363 new_data = kstrdup(new, GFP_KERNEL);
364 if (!new_data)
365 return ERR_PTR(-ENOMEM);
366
367 down_write(&_hash_lock);
368
369 /*
370 * Is new free ?
371 */
372 if (change_uuid)
373 hc = __get_uuid_cell(new);
374 else
375 hc = __get_name_cell(new);
376
377 if (hc) {
378 DMWARN("Unable to change %s on mapped device %s to one that "
379 "already exists: %s",
380 change_uuid ? "uuid" : "name",
381 param->name, new);
382 dm_put(hc->md);
383 up_write(&_hash_lock);
384 kfree(new_data);
385 return ERR_PTR(-EBUSY);
386 }
387
388 /*
389 * Is there such a device as 'old' ?
390 */
391 hc = __get_name_cell(param->name);
392 if (!hc) {
393 DMWARN("Unable to rename non-existent device, %s to %s%s",
394 param->name, change_uuid ? "uuid " : "", new);
395 up_write(&_hash_lock);
396 kfree(new_data);
397 return ERR_PTR(-ENXIO);
398 }
399
400 /*
401 * Does this device already have a uuid?
402 */
403 if (change_uuid && hc->uuid) {
404 DMWARN("Unable to change uuid of mapped device %s to %s "
405 "because uuid is already set to %s",
406 param->name, new, hc->uuid);
407 dm_put(hc->md);
408 up_write(&_hash_lock);
409 kfree(new_data);
410 return ERR_PTR(-EINVAL);
411 }
412
413 if (change_uuid)
414 __set_cell_uuid(hc, new_data);
415 else
416 old_name = __change_cell_name(hc, new_data);
417
418 /*
419 * Wake up any dm event waiters.
420 */
421 table = dm_get_live_table(hc->md);
422 if (table) {
423 dm_table_event(table);
424 dm_table_put(table);
425 }
426
427 if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr))
428 param->flags |= DM_UEVENT_GENERATED_FLAG;
429
430 md = hc->md;
431 up_write(&_hash_lock);
432 kfree(old_name);
433
434 return md;
435 }
436
437 /*-----------------------------------------------------------------
438 * Implementation of the ioctl commands
439 *---------------------------------------------------------------*/
440 /*
441 * All the ioctl commands get dispatched to functions with this
442 * prototype.
443 */
444 typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size);
445
446 static int remove_all(struct dm_ioctl *param, size_t param_size)
447 {
448 dm_hash_remove_all(1);
449 param->data_size = 0;
450 return 0;
451 }
452
453 /*
454 * Round up the ptr to an 8-byte boundary.
455 */
456 #define ALIGN_MASK 7
457 static inline void *align_ptr(void *ptr)
458 {
459 return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK);
460 }
461
462 /*
463 * Retrieves the data payload buffer from an already allocated
464 * struct dm_ioctl.
465 */
466 static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
467 size_t *len)
468 {
469 param->data_start = align_ptr(param + 1) - (void *) param;
470
471 if (param->data_start < param_size)
472 *len = param_size - param->data_start;
473 else
474 *len = 0;
475
476 return ((void *) param) + param->data_start;
477 }
478
479 static int list_devices(struct dm_ioctl *param, size_t param_size)
480 {
481 unsigned int i;
482 struct hash_cell *hc;
483 size_t len, needed = 0;
484 struct gendisk *disk;
485 struct dm_name_list *nl, *old_nl = NULL;
486
487 down_write(&_hash_lock);
488
489 /*
490 * Loop through all the devices working out how much
491 * space we need.
492 */
493 for (i = 0; i < NUM_BUCKETS; i++) {
494 list_for_each_entry (hc, _name_buckets + i, name_list) {
495 needed += sizeof(struct dm_name_list);
496 needed += strlen(hc->name) + 1;
497 needed += ALIGN_MASK;
498 }
499 }
500
501 /*
502 * Grab our output buffer.
503 */
504 nl = get_result_buffer(param, param_size, &len);
505 if (len < needed) {
506 param->flags |= DM_BUFFER_FULL_FLAG;
507 goto out;
508 }
509 param->data_size = param->data_start + needed;
510
511 nl->dev = 0; /* Flags no data */
512
513 /*
514 * Now loop through filling out the names.
515 */
516 for (i = 0; i < NUM_BUCKETS; i++) {
517 list_for_each_entry (hc, _name_buckets + i, name_list) {
518 if (old_nl)
519 old_nl->next = (uint32_t) ((void *) nl -
520 (void *) old_nl);
521 disk = dm_disk(hc->md);
522 nl->dev = huge_encode_dev(disk_devt(disk));
523 nl->next = 0;
524 strcpy(nl->name, hc->name);
525
526 old_nl = nl;
527 nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1);
528 }
529 }
530
531 out:
532 up_write(&_hash_lock);
533 return 0;
534 }
535
536 static void list_version_get_needed(struct target_type *tt, void *needed_param)
537 {
538 size_t *needed = needed_param;
539
540 *needed += sizeof(struct dm_target_versions);
541 *needed += strlen(tt->name);
542 *needed += ALIGN_MASK;
543 }
544
545 static void list_version_get_info(struct target_type *tt, void *param)
546 {
547 struct vers_iter *info = param;
548
549 /* Check space - it might have changed since the first iteration */
550 if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
551 info->end) {
552
553 info->flags = DM_BUFFER_FULL_FLAG;
554 return;
555 }
556
557 if (info->old_vers)
558 info->old_vers->next = (uint32_t) ((void *)info->vers -
559 (void *)info->old_vers);
560 info->vers->version[0] = tt->version[0];
561 info->vers->version[1] = tt->version[1];
562 info->vers->version[2] = tt->version[2];
563 info->vers->next = 0;
564 strcpy(info->vers->name, tt->name);
565
566 info->old_vers = info->vers;
567 info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
568 }
569
570 static int list_versions(struct dm_ioctl *param, size_t param_size)
571 {
572 size_t len, needed = 0;
573 struct dm_target_versions *vers;
574 struct vers_iter iter_info;
575
576 /*
577 * Loop through all the devices working out how much
578 * space we need.
579 */
580 dm_target_iterate(list_version_get_needed, &needed);
581
582 /*
583 * Grab our output buffer.
584 */
585 vers = get_result_buffer(param, param_size, &len);
586 if (len < needed) {
587 param->flags |= DM_BUFFER_FULL_FLAG;
588 goto out;
589 }
590 param->data_size = param->data_start + needed;
591
592 iter_info.param_size = param_size;
593 iter_info.old_vers = NULL;
594 iter_info.vers = vers;
595 iter_info.flags = 0;
596 iter_info.end = (char *)vers+len;
597
598 /*
599 * Now loop through filling out the names & versions.
600 */
601 dm_target_iterate(list_version_get_info, &iter_info);
602 param->flags |= iter_info.flags;
603
604 out:
605 return 0;
606 }
607
608 static int check_name(const char *name)
609 {
610 if (strchr(name, '/')) {
611 DMWARN("invalid device name");
612 return -EINVAL;
613 }
614
615 return 0;
616 }
617
618 /*
619 * On successful return, the caller must not attempt to acquire
620 * _hash_lock without first calling dm_table_put, because dm_table_destroy
621 * waits for this dm_table_put and could be called under this lock.
622 */
623 static struct dm_table *dm_get_inactive_table(struct mapped_device *md)
624 {
625 struct hash_cell *hc;
626 struct dm_table *table = NULL;
627
628 down_read(&_hash_lock);
629 hc = dm_get_mdptr(md);
630 if (!hc || hc->md != md) {
631 DMWARN("device has been removed from the dev hash table.");
632 goto out;
633 }
634
635 table = hc->new_map;
636 if (table)
637 dm_table_get(table);
638
639 out:
640 up_read(&_hash_lock);
641
642 return table;
643 }
644
645 static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
646 struct dm_ioctl *param)
647 {
648 return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
649 dm_get_inactive_table(md) : dm_get_live_table(md);
650 }
651
652 /*
653 * Fills in a dm_ioctl structure, ready for sending back to
654 * userland.
655 */
656 static void __dev_status(struct mapped_device *md, struct dm_ioctl *param)
657 {
658 struct gendisk *disk = dm_disk(md);
659 struct dm_table *table;
660
661 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
662 DM_ACTIVE_PRESENT_FLAG);
663
664 if (dm_suspended_md(md))
665 param->flags |= DM_SUSPEND_FLAG;
666
667 param->dev = huge_encode_dev(disk_devt(disk));
668
669 /*
670 * Yes, this will be out of date by the time it gets back
671 * to userland, but it is still very useful for
672 * debugging.
673 */
674 param->open_count = dm_open_count(md);
675
676 param->event_nr = dm_get_event_nr(md);
677 param->target_count = 0;
678
679 table = dm_get_live_table(md);
680 if (table) {
681 if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
682 if (get_disk_ro(disk))
683 param->flags |= DM_READONLY_FLAG;
684 param->target_count = dm_table_get_num_targets(table);
685 }
686 dm_table_put(table);
687
688 param->flags |= DM_ACTIVE_PRESENT_FLAG;
689 }
690
691 if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
692 table = dm_get_inactive_table(md);
693 if (table) {
694 if (!(dm_table_get_mode(table) & FMODE_WRITE))
695 param->flags |= DM_READONLY_FLAG;
696 param->target_count = dm_table_get_num_targets(table);
697 dm_table_put(table);
698 }
699 }
700 }
701
702 static int dev_create(struct dm_ioctl *param, size_t param_size)
703 {
704 int r, m = DM_ANY_MINOR;
705 struct mapped_device *md;
706
707 r = check_name(param->name);
708 if (r)
709 return r;
710
711 if (param->flags & DM_PERSISTENT_DEV_FLAG)
712 m = MINOR(huge_decode_dev(param->dev));
713
714 r = dm_create(m, &md);
715 if (r)
716 return r;
717
718 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
719 if (r) {
720 dm_put(md);
721 dm_destroy(md);
722 return r;
723 }
724
725 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
726
727 __dev_status(md, param);
728
729 dm_put(md);
730
731 return 0;
732 }
733
734 /*
735 * Always use UUID for lookups if it's present, otherwise use name or dev.
736 */
737 static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
738 {
739 struct hash_cell *hc = NULL;
740
741 if (*param->uuid) {
742 if (*param->name || param->dev)
743 return NULL;
744
745 hc = __get_uuid_cell(param->uuid);
746 if (!hc)
747 return NULL;
748 } else if (*param->name) {
749 if (param->dev)
750 return NULL;
751
752 hc = __get_name_cell(param->name);
753 if (!hc)
754 return NULL;
755 } else if (param->dev) {
756 hc = __get_dev_cell(param->dev);
757 if (!hc)
758 return NULL;
759 } else
760 return NULL;
761
762 /*
763 * Sneakily write in both the name and the uuid
764 * while we have the cell.
765 */
766 strlcpy(param->name, hc->name, sizeof(param->name));
767 if (hc->uuid)
768 strlcpy(param->uuid, hc->uuid, sizeof(param->uuid));
769 else
770 param->uuid[0] = '\0';
771
772 if (hc->new_map)
773 param->flags |= DM_INACTIVE_PRESENT_FLAG;
774 else
775 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
776
777 return hc;
778 }
779
780 static struct mapped_device *find_device(struct dm_ioctl *param)
781 {
782 struct hash_cell *hc;
783 struct mapped_device *md = NULL;
784
785 down_read(&_hash_lock);
786 hc = __find_device_hash_cell(param);
787 if (hc)
788 md = hc->md;
789 up_read(&_hash_lock);
790
791 return md;
792 }
793
794 static int dev_remove(struct dm_ioctl *param, size_t param_size)
795 {
796 struct hash_cell *hc;
797 struct mapped_device *md;
798 int r;
799
800 down_write(&_hash_lock);
801 hc = __find_device_hash_cell(param);
802
803 if (!hc) {
804 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
805 up_write(&_hash_lock);
806 return -ENXIO;
807 }
808
809 md = hc->md;
810
811 /*
812 * Ensure the device is not open and nothing further can open it.
813 */
814 r = dm_lock_for_deletion(md);
815 if (r) {
816 DMDEBUG_LIMIT("unable to remove open device %s", hc->name);
817 up_write(&_hash_lock);
818 dm_put(md);
819 return r;
820 }
821
822 __hash_remove(hc);
823 up_write(&_hash_lock);
824
825 if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr))
826 param->flags |= DM_UEVENT_GENERATED_FLAG;
827
828 dm_put(md);
829 dm_destroy(md);
830 return 0;
831 }
832
833 /*
834 * Check a string doesn't overrun the chunk of
835 * memory we copied from userland.
836 */
837 static int invalid_str(char *str, void *end)
838 {
839 while ((void *) str < end)
840 if (!*str++)
841 return 0;
842
843 return -EINVAL;
844 }
845
846 static int dev_rename(struct dm_ioctl *param, size_t param_size)
847 {
848 int r;
849 char *new_data = (char *) param + param->data_start;
850 struct mapped_device *md;
851 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
852
853 if (new_data < param->data ||
854 invalid_str(new_data, (void *) param + param_size) ||
855 strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
856 DMWARN("Invalid new mapped device name or uuid string supplied.");
857 return -EINVAL;
858 }
859
860 if (!change_uuid) {
861 r = check_name(new_data);
862 if (r)
863 return r;
864 }
865
866 md = dm_hash_rename(param, new_data);
867 if (IS_ERR(md))
868 return PTR_ERR(md);
869
870 __dev_status(md, param);
871 dm_put(md);
872
873 return 0;
874 }
875
876 static int dev_set_geometry(struct dm_ioctl *param, size_t param_size)
877 {
878 int r = -EINVAL, x;
879 struct mapped_device *md;
880 struct hd_geometry geometry;
881 unsigned long indata[4];
882 char *geostr = (char *) param + param->data_start;
883
884 md = find_device(param);
885 if (!md)
886 return -ENXIO;
887
888 if (geostr < param->data ||
889 invalid_str(geostr, (void *) param + param_size)) {
890 DMWARN("Invalid geometry supplied.");
891 goto out;
892 }
893
894 x = sscanf(geostr, "%lu %lu %lu %lu", indata,
895 indata + 1, indata + 2, indata + 3);
896
897 if (x != 4) {
898 DMWARN("Unable to interpret geometry settings.");
899 goto out;
900 }
901
902 if (indata[0] > 65535 || indata[1] > 255 ||
903 indata[2] > 255 || indata[3] > ULONG_MAX) {
904 DMWARN("Geometry exceeds range limits.");
905 goto out;
906 }
907
908 geometry.cylinders = indata[0];
909 geometry.heads = indata[1];
910 geometry.sectors = indata[2];
911 geometry.start = indata[3];
912
913 r = dm_set_geometry(md, &geometry);
914
915 param->data_size = 0;
916
917 out:
918 dm_put(md);
919 return r;
920 }
921
922 static int do_suspend(struct dm_ioctl *param)
923 {
924 int r = 0;
925 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
926 struct mapped_device *md;
927
928 md = find_device(param);
929 if (!md)
930 return -ENXIO;
931
932 if (param->flags & DM_SKIP_LOCKFS_FLAG)
933 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
934 if (param->flags & DM_NOFLUSH_FLAG)
935 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
936
937 if (!dm_suspended_md(md)) {
938 r = dm_suspend(md, suspend_flags);
939 if (r)
940 goto out;
941 }
942
943 __dev_status(md, param);
944
945 out:
946 dm_put(md);
947
948 return r;
949 }
950
951 static int do_resume(struct dm_ioctl *param)
952 {
953 int r = 0;
954 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
955 struct hash_cell *hc;
956 struct mapped_device *md;
957 struct dm_table *new_map, *old_map = NULL;
958
959 down_write(&_hash_lock);
960
961 hc = __find_device_hash_cell(param);
962 if (!hc) {
963 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
964 up_write(&_hash_lock);
965 return -ENXIO;
966 }
967
968 md = hc->md;
969
970 new_map = hc->new_map;
971 hc->new_map = NULL;
972 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
973
974 up_write(&_hash_lock);
975
976 /* Do we need to load a new map ? */
977 if (new_map) {
978 /* Suspend if it isn't already suspended */
979 if (param->flags & DM_SKIP_LOCKFS_FLAG)
980 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
981 if (param->flags & DM_NOFLUSH_FLAG)
982 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
983 if (!dm_suspended_md(md))
984 dm_suspend(md, suspend_flags);
985
986 old_map = dm_swap_table(md, new_map);
987 if (IS_ERR(old_map)) {
988 dm_table_destroy(new_map);
989 dm_put(md);
990 return PTR_ERR(old_map);
991 }
992
993 if (dm_table_get_mode(new_map) & FMODE_WRITE)
994 set_disk_ro(dm_disk(md), 0);
995 else
996 set_disk_ro(dm_disk(md), 1);
997 }
998
999 if (dm_suspended_md(md)) {
1000 r = dm_resume(md);
1001 if (!r && !dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr))
1002 param->flags |= DM_UEVENT_GENERATED_FLAG;
1003 }
1004
1005 if (old_map)
1006 dm_table_destroy(old_map);
1007
1008 if (!r)
1009 __dev_status(md, param);
1010
1011 dm_put(md);
1012 return r;
1013 }
1014
1015 /*
1016 * Set or unset the suspension state of a device.
1017 * If the device already is in the requested state we just return its status.
1018 */
1019 static int dev_suspend(struct dm_ioctl *param, size_t param_size)
1020 {
1021 if (param->flags & DM_SUSPEND_FLAG)
1022 return do_suspend(param);
1023
1024 return do_resume(param);
1025 }
1026
1027 /*
1028 * Copies device info back to user space, used by
1029 * the create and info ioctls.
1030 */
1031 static int dev_status(struct dm_ioctl *param, size_t param_size)
1032 {
1033 struct mapped_device *md;
1034
1035 md = find_device(param);
1036 if (!md)
1037 return -ENXIO;
1038
1039 __dev_status(md, param);
1040 dm_put(md);
1041
1042 return 0;
1043 }
1044
1045 /*
1046 * Build up the status struct for each target
1047 */
1048 static void retrieve_status(struct dm_table *table,
1049 struct dm_ioctl *param, size_t param_size)
1050 {
1051 unsigned int i, num_targets;
1052 struct dm_target_spec *spec;
1053 char *outbuf, *outptr;
1054 status_type_t type;
1055 size_t remaining, len, used = 0;
1056
1057 outptr = outbuf = get_result_buffer(param, param_size, &len);
1058
1059 if (param->flags & DM_STATUS_TABLE_FLAG)
1060 type = STATUSTYPE_TABLE;
1061 else
1062 type = STATUSTYPE_INFO;
1063
1064 /* Get all the target info */
1065 num_targets = dm_table_get_num_targets(table);
1066 for (i = 0; i < num_targets; i++) {
1067 struct dm_target *ti = dm_table_get_target(table, i);
1068
1069 remaining = len - (outptr - outbuf);
1070 if (remaining <= sizeof(struct dm_target_spec)) {
1071 param->flags |= DM_BUFFER_FULL_FLAG;
1072 break;
1073 }
1074
1075 spec = (struct dm_target_spec *) outptr;
1076
1077 spec->status = 0;
1078 spec->sector_start = ti->begin;
1079 spec->length = ti->len;
1080 strncpy(spec->target_type, ti->type->name,
1081 sizeof(spec->target_type));
1082
1083 outptr += sizeof(struct dm_target_spec);
1084 remaining = len - (outptr - outbuf);
1085 if (remaining <= 0) {
1086 param->flags |= DM_BUFFER_FULL_FLAG;
1087 break;
1088 }
1089
1090 /* Get the status/table string from the target driver */
1091 if (ti->type->status) {
1092 if (ti->type->status(ti, type, outptr, remaining)) {
1093 param->flags |= DM_BUFFER_FULL_FLAG;
1094 break;
1095 }
1096 } else
1097 outptr[0] = '\0';
1098
1099 outptr += strlen(outptr) + 1;
1100 used = param->data_start + (outptr - outbuf);
1101
1102 outptr = align_ptr(outptr);
1103 spec->next = outptr - outbuf;
1104 }
1105
1106 if (used)
1107 param->data_size = used;
1108
1109 param->target_count = num_targets;
1110 }
1111
1112 /*
1113 * Wait for a device to report an event
1114 */
1115 static int dev_wait(struct dm_ioctl *param, size_t param_size)
1116 {
1117 int r = 0;
1118 struct mapped_device *md;
1119 struct dm_table *table;
1120
1121 md = find_device(param);
1122 if (!md)
1123 return -ENXIO;
1124
1125 /*
1126 * Wait for a notification event
1127 */
1128 if (dm_wait_event(md, param->event_nr)) {
1129 r = -ERESTARTSYS;
1130 goto out;
1131 }
1132
1133 /*
1134 * The userland program is going to want to know what
1135 * changed to trigger the event, so we may as well tell
1136 * him and save an ioctl.
1137 */
1138 __dev_status(md, param);
1139
1140 table = dm_get_live_or_inactive_table(md, param);
1141 if (table) {
1142 retrieve_status(table, param, param_size);
1143 dm_table_put(table);
1144 }
1145
1146 out:
1147 dm_put(md);
1148
1149 return r;
1150 }
1151
1152 static inline fmode_t get_mode(struct dm_ioctl *param)
1153 {
1154 fmode_t mode = FMODE_READ | FMODE_WRITE;
1155
1156 if (param->flags & DM_READONLY_FLAG)
1157 mode = FMODE_READ;
1158
1159 return mode;
1160 }
1161
1162 static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
1163 struct dm_target_spec **spec, char **target_params)
1164 {
1165 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1166 *target_params = (char *) (*spec + 1);
1167
1168 if (*spec < (last + 1))
1169 return -EINVAL;
1170
1171 return invalid_str(*target_params, end);
1172 }
1173
1174 static int populate_table(struct dm_table *table,
1175 struct dm_ioctl *param, size_t param_size)
1176 {
1177 int r;
1178 unsigned int i = 0;
1179 struct dm_target_spec *spec = (struct dm_target_spec *) param;
1180 uint32_t next = param->data_start;
1181 void *end = (void *) param + param_size;
1182 char *target_params;
1183
1184 if (!param->target_count) {
1185 DMWARN("populate_table: no targets specified");
1186 return -EINVAL;
1187 }
1188
1189 for (i = 0; i < param->target_count; i++) {
1190
1191 r = next_target(spec, next, end, &spec, &target_params);
1192 if (r) {
1193 DMWARN("unable to find target");
1194 return r;
1195 }
1196
1197 r = dm_table_add_target(table, spec->target_type,
1198 (sector_t) spec->sector_start,
1199 (sector_t) spec->length,
1200 target_params);
1201 if (r) {
1202 DMWARN("error adding target to table");
1203 return r;
1204 }
1205
1206 next = spec->next;
1207 }
1208
1209 return dm_table_complete(table);
1210 }
1211
1212 static int table_load(struct dm_ioctl *param, size_t param_size)
1213 {
1214 int r;
1215 struct hash_cell *hc;
1216 struct dm_table *t;
1217 struct mapped_device *md;
1218
1219 md = find_device(param);
1220 if (!md)
1221 return -ENXIO;
1222
1223 r = dm_table_create(&t, get_mode(param), param->target_count, md);
1224 if (r)
1225 goto out;
1226
1227 r = populate_table(t, param, param_size);
1228 if (r) {
1229 dm_table_destroy(t);
1230 goto out;
1231 }
1232
1233 /* Protect md->type and md->queue against concurrent table loads. */
1234 dm_lock_md_type(md);
1235 if (dm_get_md_type(md) == DM_TYPE_NONE)
1236 /* Initial table load: acquire type of table. */
1237 dm_set_md_type(md, dm_table_get_type(t));
1238 else if (dm_get_md_type(md) != dm_table_get_type(t)) {
1239 DMWARN("can't change device type after initial table load.");
1240 dm_table_destroy(t);
1241 dm_unlock_md_type(md);
1242 r = -EINVAL;
1243 goto out;
1244 }
1245
1246 /* setup md->queue to reflect md's type (may block) */
1247 r = dm_setup_md_queue(md);
1248 if (r) {
1249 DMWARN("unable to set up device queue for new table.");
1250 dm_table_destroy(t);
1251 dm_unlock_md_type(md);
1252 goto out;
1253 }
1254 dm_unlock_md_type(md);
1255
1256 /* stage inactive table */
1257 down_write(&_hash_lock);
1258 hc = dm_get_mdptr(md);
1259 if (!hc || hc->md != md) {
1260 DMWARN("device has been removed from the dev hash table.");
1261 dm_table_destroy(t);
1262 up_write(&_hash_lock);
1263 r = -ENXIO;
1264 goto out;
1265 }
1266
1267 if (hc->new_map)
1268 dm_table_destroy(hc->new_map);
1269 hc->new_map = t;
1270 up_write(&_hash_lock);
1271
1272 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1273 __dev_status(md, param);
1274
1275 out:
1276 dm_put(md);
1277
1278 return r;
1279 }
1280
1281 static int table_clear(struct dm_ioctl *param, size_t param_size)
1282 {
1283 struct hash_cell *hc;
1284 struct mapped_device *md;
1285
1286 down_write(&_hash_lock);
1287
1288 hc = __find_device_hash_cell(param);
1289 if (!hc) {
1290 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1291 up_write(&_hash_lock);
1292 return -ENXIO;
1293 }
1294
1295 if (hc->new_map) {
1296 dm_table_destroy(hc->new_map);
1297 hc->new_map = NULL;
1298 }
1299
1300 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1301
1302 __dev_status(hc->md, param);
1303 md = hc->md;
1304 up_write(&_hash_lock);
1305 dm_put(md);
1306
1307 return 0;
1308 }
1309
1310 /*
1311 * Retrieves a list of devices used by a particular dm device.
1312 */
1313 static void retrieve_deps(struct dm_table *table,
1314 struct dm_ioctl *param, size_t param_size)
1315 {
1316 unsigned int count = 0;
1317 struct list_head *tmp;
1318 size_t len, needed;
1319 struct dm_dev_internal *dd;
1320 struct dm_target_deps *deps;
1321
1322 deps = get_result_buffer(param, param_size, &len);
1323
1324 /*
1325 * Count the devices.
1326 */
1327 list_for_each (tmp, dm_table_get_devices(table))
1328 count++;
1329
1330 /*
1331 * Check we have enough space.
1332 */
1333 needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
1334 if (len < needed) {
1335 param->flags |= DM_BUFFER_FULL_FLAG;
1336 return;
1337 }
1338
1339 /*
1340 * Fill in the devices.
1341 */
1342 deps->count = count;
1343 count = 0;
1344 list_for_each_entry (dd, dm_table_get_devices(table), list)
1345 deps->dev[count++] = huge_encode_dev(dd->dm_dev.bdev->bd_dev);
1346
1347 param->data_size = param->data_start + needed;
1348 }
1349
1350 static int table_deps(struct dm_ioctl *param, size_t param_size)
1351 {
1352 struct mapped_device *md;
1353 struct dm_table *table;
1354
1355 md = find_device(param);
1356 if (!md)
1357 return -ENXIO;
1358
1359 __dev_status(md, param);
1360
1361 table = dm_get_live_or_inactive_table(md, param);
1362 if (table) {
1363 retrieve_deps(table, param, param_size);
1364 dm_table_put(table);
1365 }
1366
1367 dm_put(md);
1368
1369 return 0;
1370 }
1371
1372 /*
1373 * Return the status of a device as a text string for each
1374 * target.
1375 */
1376 static int table_status(struct dm_ioctl *param, size_t param_size)
1377 {
1378 struct mapped_device *md;
1379 struct dm_table *table;
1380
1381 md = find_device(param);
1382 if (!md)
1383 return -ENXIO;
1384
1385 __dev_status(md, param);
1386
1387 table = dm_get_live_or_inactive_table(md, param);
1388 if (table) {
1389 retrieve_status(table, param, param_size);
1390 dm_table_put(table);
1391 }
1392
1393 dm_put(md);
1394
1395 return 0;
1396 }
1397
1398 /*
1399 * Pass a message to the target that's at the supplied device offset.
1400 */
1401 static int target_message(struct dm_ioctl *param, size_t param_size)
1402 {
1403 int r, argc;
1404 char **argv;
1405 struct mapped_device *md;
1406 struct dm_table *table;
1407 struct dm_target *ti;
1408 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1409
1410 md = find_device(param);
1411 if (!md)
1412 return -ENXIO;
1413
1414 if (tmsg < (struct dm_target_msg *) param->data ||
1415 invalid_str(tmsg->message, (void *) param + param_size)) {
1416 DMWARN("Invalid target message parameters.");
1417 r = -EINVAL;
1418 goto out;
1419 }
1420
1421 r = dm_split_args(&argc, &argv, tmsg->message);
1422 if (r) {
1423 DMWARN("Failed to split target message parameters");
1424 goto out;
1425 }
1426
1427 if (!argc) {
1428 DMWARN("Empty message received.");
1429 goto out;
1430 }
1431
1432 table = dm_get_live_table(md);
1433 if (!table)
1434 goto out_argv;
1435
1436 if (dm_deleting_md(md)) {
1437 r = -ENXIO;
1438 goto out_table;
1439 }
1440
1441 ti = dm_table_find_target(table, tmsg->sector);
1442 if (!dm_target_is_valid(ti)) {
1443 DMWARN("Target message sector outside device.");
1444 r = -EINVAL;
1445 } else if (ti->type->message)
1446 r = ti->type->message(ti, argc, argv);
1447 else {
1448 DMWARN("Target type does not support messages");
1449 r = -EINVAL;
1450 }
1451
1452 out_table:
1453 dm_table_put(table);
1454 out_argv:
1455 kfree(argv);
1456 out:
1457 param->data_size = 0;
1458 dm_put(md);
1459 return r;
1460 }
1461
1462 /*-----------------------------------------------------------------
1463 * Implementation of open/close/ioctl on the special char
1464 * device.
1465 *---------------------------------------------------------------*/
1466 static ioctl_fn lookup_ioctl(unsigned int cmd)
1467 {
1468 static struct {
1469 int cmd;
1470 ioctl_fn fn;
1471 } _ioctls[] = {
1472 {DM_VERSION_CMD, NULL}, /* version is dealt with elsewhere */
1473 {DM_REMOVE_ALL_CMD, remove_all},
1474 {DM_LIST_DEVICES_CMD, list_devices},
1475
1476 {DM_DEV_CREATE_CMD, dev_create},
1477 {DM_DEV_REMOVE_CMD, dev_remove},
1478 {DM_DEV_RENAME_CMD, dev_rename},
1479 {DM_DEV_SUSPEND_CMD, dev_suspend},
1480 {DM_DEV_STATUS_CMD, dev_status},
1481 {DM_DEV_WAIT_CMD, dev_wait},
1482
1483 {DM_TABLE_LOAD_CMD, table_load},
1484 {DM_TABLE_CLEAR_CMD, table_clear},
1485 {DM_TABLE_DEPS_CMD, table_deps},
1486 {DM_TABLE_STATUS_CMD, table_status},
1487
1488 {DM_LIST_VERSIONS_CMD, list_versions},
1489
1490 {DM_TARGET_MSG_CMD, target_message},
1491 {DM_DEV_SET_GEOMETRY_CMD, dev_set_geometry}
1492 };
1493
1494 return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn;
1495 }
1496
1497 /*
1498 * As well as checking the version compatibility this always
1499 * copies the kernel interface version out.
1500 */
1501 static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1502 {
1503 uint32_t version[3];
1504 int r = 0;
1505
1506 if (copy_from_user(version, user->version, sizeof(version)))
1507 return -EFAULT;
1508
1509 if ((DM_VERSION_MAJOR != version[0]) ||
1510 (DM_VERSION_MINOR < version[1])) {
1511 DMWARN("ioctl interface mismatch: "
1512 "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1513 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1514 DM_VERSION_PATCHLEVEL,
1515 version[0], version[1], version[2], cmd);
1516 r = -EINVAL;
1517 }
1518
1519 /*
1520 * Fill in the kernel version.
1521 */
1522 version[0] = DM_VERSION_MAJOR;
1523 version[1] = DM_VERSION_MINOR;
1524 version[2] = DM_VERSION_PATCHLEVEL;
1525 if (copy_to_user(user->version, version, sizeof(version)))
1526 return -EFAULT;
1527
1528 return r;
1529 }
1530
1531 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
1532 {
1533 struct dm_ioctl tmp, *dmi;
1534 int secure_data;
1535
1536 if (copy_from_user(&tmp, user, sizeof(tmp) - sizeof(tmp.data)))
1537 return -EFAULT;
1538
1539 if (tmp.data_size < (sizeof(tmp) - sizeof(tmp.data)))
1540 return -EINVAL;
1541
1542 secure_data = tmp.flags & DM_SECURE_DATA_FLAG;
1543
1544 dmi = vmalloc(tmp.data_size);
1545 if (!dmi) {
1546 if (secure_data && clear_user(user, tmp.data_size))
1547 return -EFAULT;
1548 return -ENOMEM;
1549 }
1550
1551 if (copy_from_user(dmi, user, tmp.data_size))
1552 goto bad;
1553
1554 /* Wipe the user buffer so we do not return it to userspace */
1555 if (secure_data && clear_user(user, tmp.data_size))
1556 goto bad;
1557
1558 *param = dmi;
1559 return 0;
1560
1561 bad:
1562 if (secure_data)
1563 memset(dmi, 0, tmp.data_size);
1564 vfree(dmi);
1565 return -EFAULT;
1566 }
1567
1568 static int validate_params(uint cmd, struct dm_ioctl *param)
1569 {
1570 /* Always clear this flag */
1571 param->flags &= ~DM_BUFFER_FULL_FLAG;
1572 param->flags &= ~DM_UEVENT_GENERATED_FLAG;
1573 param->flags &= ~DM_SECURE_DATA_FLAG;
1574
1575 /* Ignores parameters */
1576 if (cmd == DM_REMOVE_ALL_CMD ||
1577 cmd == DM_LIST_DEVICES_CMD ||
1578 cmd == DM_LIST_VERSIONS_CMD)
1579 return 0;
1580
1581 if ((cmd == DM_DEV_CREATE_CMD)) {
1582 if (!*param->name) {
1583 DMWARN("name not supplied when creating device");
1584 return -EINVAL;
1585 }
1586 } else if ((*param->uuid && *param->name)) {
1587 DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
1588 return -EINVAL;
1589 }
1590
1591 /* Ensure strings are terminated */
1592 param->name[DM_NAME_LEN - 1] = '\0';
1593 param->uuid[DM_UUID_LEN - 1] = '\0';
1594
1595 return 0;
1596 }
1597
1598 static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
1599 {
1600 int r = 0;
1601 int wipe_buffer;
1602 unsigned int cmd;
1603 struct dm_ioctl *uninitialized_var(param);
1604 ioctl_fn fn = NULL;
1605 size_t input_param_size;
1606
1607 /* only root can play with this */
1608 if (!capable(CAP_SYS_ADMIN))
1609 return -EACCES;
1610
1611 if (_IOC_TYPE(command) != DM_IOCTL)
1612 return -ENOTTY;
1613
1614 cmd = _IOC_NR(command);
1615
1616 /*
1617 * Check the interface version passed in. This also
1618 * writes out the kernel's interface version.
1619 */
1620 r = check_version(cmd, user);
1621 if (r)
1622 return r;
1623
1624 /*
1625 * Nothing more to do for the version command.
1626 */
1627 if (cmd == DM_VERSION_CMD)
1628 return 0;
1629
1630 fn = lookup_ioctl(cmd);
1631 if (!fn) {
1632 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1633 return -ENOTTY;
1634 }
1635
1636 /*
1637 * Trying to avoid low memory issues when a device is
1638 * suspended.
1639 */
1640 current->flags |= PF_MEMALLOC;
1641
1642 /*
1643 * Copy the parameters into kernel space.
1644 */
1645 r = copy_params(user, &param);
1646
1647 current->flags &= ~PF_MEMALLOC;
1648
1649 if (r)
1650 return r;
1651
1652 input_param_size = param->data_size;
1653 wipe_buffer = param->flags & DM_SECURE_DATA_FLAG;
1654
1655 r = validate_params(cmd, param);
1656 if (r)
1657 goto out;
1658
1659 param->data_size = sizeof(*param);
1660 r = fn(param, input_param_size);
1661
1662 /*
1663 * Copy the results back to userland.
1664 */
1665 if (!r && copy_to_user(user, param, param->data_size))
1666 r = -EFAULT;
1667
1668 out:
1669 if (wipe_buffer)
1670 memset(param, 0, input_param_size);
1671
1672 vfree(param);
1673 return r;
1674 }
1675
1676 static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
1677 {
1678 return (long)ctl_ioctl(command, (struct dm_ioctl __user *)u);
1679 }
1680
1681 #ifdef CONFIG_COMPAT
1682 static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
1683 {
1684 return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
1685 }
1686 #else
1687 #define dm_compat_ctl_ioctl NULL
1688 #endif
1689
1690 static const struct file_operations _ctl_fops = {
1691 .open = nonseekable_open,
1692 .unlocked_ioctl = dm_ctl_ioctl,
1693 .compat_ioctl = dm_compat_ctl_ioctl,
1694 .owner = THIS_MODULE,
1695 .llseek = noop_llseek,
1696 };
1697
1698 static struct miscdevice _dm_misc = {
1699 .minor = MAPPER_CTRL_MINOR,
1700 .name = DM_NAME,
1701 .nodename = DM_DIR "/" DM_CONTROL_NODE,
1702 .fops = &_ctl_fops
1703 };
1704
1705 MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
1706 MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
1707
1708 /*
1709 * Create misc character device and link to DM_DIR/control.
1710 */
1711 int __init dm_interface_init(void)
1712 {
1713 int r;
1714
1715 r = dm_hash_init();
1716 if (r)
1717 return r;
1718
1719 r = misc_register(&_dm_misc);
1720 if (r) {
1721 DMERR("misc_register failed for control device");
1722 dm_hash_exit();
1723 return r;
1724 }
1725
1726 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
1727 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
1728 DM_DRIVER_EMAIL);
1729 return 0;
1730 }
1731
1732 void dm_interface_exit(void)
1733 {
1734 if (misc_deregister(&_dm_misc) < 0)
1735 DMERR("misc_deregister failed for control device");
1736
1737 dm_hash_exit();
1738 }
1739
1740 /**
1741 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
1742 * @md: Pointer to mapped_device
1743 * @name: Buffer (size DM_NAME_LEN) for name
1744 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
1745 */
1746 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
1747 {
1748 int r = 0;
1749 struct hash_cell *hc;
1750
1751 if (!md)
1752 return -ENXIO;
1753
1754 mutex_lock(&dm_hash_cells_mutex);
1755 hc = dm_get_mdptr(md);
1756 if (!hc || hc->md != md) {
1757 r = -ENXIO;
1758 goto out;
1759 }
1760
1761 if (name)
1762 strcpy(name, hc->name);
1763 if (uuid)
1764 strcpy(uuid, hc->uuid ? : "");
1765
1766 out:
1767 mutex_unlock(&dm_hash_cells_mutex);
1768
1769 return r;
1770 }
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