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Merge branch 'gpio/next' of git://git.secretlab.ca/git/linux-2.6
[linux-2.6/x86.git] / drivers / md / dm-ioctl.c
blob4cacdad2270a345e1ef8455eddf5c2a2838a22e1
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 /*-----------------------------------------------------------------
132 * Inserting, removing and renaming a device.
133 *---------------------------------------------------------------*/
134 static struct hash_cell *alloc_cell(const char *name, const char *uuid,
135 struct mapped_device *md)
136 {
137 struct hash_cell *hc;
138
139 hc = kmalloc(sizeof(*hc), GFP_KERNEL);
140 if (!hc)
141 return NULL;
142
143 hc->name = kstrdup(name, GFP_KERNEL);
144 if (!hc->name) {
145 kfree(hc);
146 return NULL;
147 }
148
149 if (!uuid)
150 hc->uuid = NULL;
151
152 else {
153 hc->uuid = kstrdup(uuid, GFP_KERNEL);
154 if (!hc->uuid) {
155 kfree(hc->name);
156 kfree(hc);
157 return NULL;
158 }
159 }
160
161 INIT_LIST_HEAD(&hc->name_list);
162 INIT_LIST_HEAD(&hc->uuid_list);
163 hc->md = md;
164 hc->new_map = NULL;
165 return hc;
166 }
167
168 static void free_cell(struct hash_cell *hc)
169 {
170 if (hc) {
171 kfree(hc->name);
172 kfree(hc->uuid);
173 kfree(hc);
174 }
175 }
176
177 /*
178 * The kdev_t and uuid of a device can never change once it is
179 * initially inserted.
180 */
181 static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
182 {
183 struct hash_cell *cell, *hc;
184
185 /*
186 * Allocate the new cells.
187 */
188 cell = alloc_cell(name, uuid, md);
189 if (!cell)
190 return -ENOMEM;
191
192 /*
193 * Insert the cell into both hash tables.
194 */
195 down_write(&_hash_lock);
196 hc = __get_name_cell(name);
197 if (hc) {
198 dm_put(hc->md);
199 goto bad;
200 }
201
202 list_add(&cell->name_list, _name_buckets + hash_str(name));
203
204 if (uuid) {
205 hc = __get_uuid_cell(uuid);
206 if (hc) {
207 list_del(&cell->name_list);
208 dm_put(hc->md);
209 goto bad;
210 }
211 list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
212 }
213 dm_get(md);
214 mutex_lock(&dm_hash_cells_mutex);
215 dm_set_mdptr(md, cell);
216 mutex_unlock(&dm_hash_cells_mutex);
217 up_write(&_hash_lock);
218
219 return 0;
220
221 bad:
222 up_write(&_hash_lock);
223 free_cell(cell);
224 return -EBUSY;
225 }
226
227 static void __hash_remove(struct hash_cell *hc)
228 {
229 struct dm_table *table;
230
231 /* remove from the dev hash */
232 list_del(&hc->uuid_list);
233 list_del(&hc->name_list);
234 mutex_lock(&dm_hash_cells_mutex);
235 dm_set_mdptr(hc->md, NULL);
236 mutex_unlock(&dm_hash_cells_mutex);
237
238 table = dm_get_live_table(hc->md);
239 if (table) {
240 dm_table_event(table);
241 dm_table_put(table);
242 }
243
244 if (hc->new_map)
245 dm_table_destroy(hc->new_map);
246 dm_put(hc->md);
247 free_cell(hc);
248 }
249
250 static void dm_hash_remove_all(int keep_open_devices)
251 {
252 int i, dev_skipped;
253 struct hash_cell *hc;
254 struct mapped_device *md;
255
256 retry:
257 dev_skipped = 0;
258
259 down_write(&_hash_lock);
260
261 for (i = 0; i < NUM_BUCKETS; i++) {
262 list_for_each_entry(hc, _name_buckets + i, name_list) {
263 md = hc->md;
264 dm_get(md);
265
266 if (keep_open_devices && dm_lock_for_deletion(md)) {
267 dm_put(md);
268 dev_skipped++;
269 continue;
270 }
271
272 __hash_remove(hc);
273
274 up_write(&_hash_lock);
275
276 dm_put(md);
277 if (likely(keep_open_devices))
278 dm_destroy(md);
279 else
280 dm_destroy_immediate(md);
281
282 /*
283 * Some mapped devices may be using other mapped
284 * devices, so repeat until we make no further
285 * progress. If a new mapped device is created
286 * here it will also get removed.
287 */
288 goto retry;
289 }
290 }
291
292 up_write(&_hash_lock);
293
294 if (dev_skipped)
295 DMWARN("remove_all left %d open device(s)", dev_skipped);
296 }
297
298 /*
299 * Set the uuid of a hash_cell that isn't already set.
300 */
301 static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
302 {
303 mutex_lock(&dm_hash_cells_mutex);
304 hc->uuid = new_uuid;
305 mutex_unlock(&dm_hash_cells_mutex);
306
307 list_add(&hc->uuid_list, _uuid_buckets + hash_str(new_uuid));
308 }
309
310 /*
311 * Changes the name of a hash_cell and returns the old name for
312 * the caller to free.
313 */
314 static char *__change_cell_name(struct hash_cell *hc, char *new_name)
315 {
316 char *old_name;
317
318 /*
319 * Rename and move the name cell.
320 */
321 list_del(&hc->name_list);
322 old_name = hc->name;
323
324 mutex_lock(&dm_hash_cells_mutex);
325 hc->name = new_name;
326 mutex_unlock(&dm_hash_cells_mutex);
327
328 list_add(&hc->name_list, _name_buckets + hash_str(new_name));
329
330 return old_name;
331 }
332
333 static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
334 const char *new)
335 {
336 char *new_data, *old_name = NULL;
337 struct hash_cell *hc;
338 struct dm_table *table;
339 struct mapped_device *md;
340 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
341
342 /*
343 * duplicate new.
344 */
345 new_data = kstrdup(new, GFP_KERNEL);
346 if (!new_data)
347 return ERR_PTR(-ENOMEM);
348
349 down_write(&_hash_lock);
350
351 /*
352 * Is new free ?
353 */
354 if (change_uuid)
355 hc = __get_uuid_cell(new);
356 else
357 hc = __get_name_cell(new);
358
359 if (hc) {
360 DMWARN("Unable to change %s on mapped device %s to one that "
361 "already exists: %s",
362 change_uuid ? "uuid" : "name",
363 param->name, new);
364 dm_put(hc->md);
365 up_write(&_hash_lock);
366 kfree(new_data);
367 return ERR_PTR(-EBUSY);
368 }
369
370 /*
371 * Is there such a device as 'old' ?
372 */
373 hc = __get_name_cell(param->name);
374 if (!hc) {
375 DMWARN("Unable to rename non-existent device, %s to %s%s",
376 param->name, change_uuid ? "uuid " : "", new);
377 up_write(&_hash_lock);
378 kfree(new_data);
379 return ERR_PTR(-ENXIO);
380 }
381
382 /*
383 * Does this device already have a uuid?
384 */
385 if (change_uuid && hc->uuid) {
386 DMWARN("Unable to change uuid of mapped device %s to %s "
387 "because uuid is already set to %s",
388 param->name, new, hc->uuid);
389 dm_put(hc->md);
390 up_write(&_hash_lock);
391 kfree(new_data);
392 return ERR_PTR(-EINVAL);
393 }
394
395 if (change_uuid)
396 __set_cell_uuid(hc, new_data);
397 else
398 old_name = __change_cell_name(hc, new_data);
399
400 /*
401 * Wake up any dm event waiters.
402 */
403 table = dm_get_live_table(hc->md);
404 if (table) {
405 dm_table_event(table);
406 dm_table_put(table);
407 }
408
409 if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr))
410 param->flags |= DM_UEVENT_GENERATED_FLAG;
411
412 md = hc->md;
413 up_write(&_hash_lock);
414 kfree(old_name);
415
416 return md;
417 }
418
419 /*-----------------------------------------------------------------
420 * Implementation of the ioctl commands
421 *---------------------------------------------------------------*/
422 /*
423 * All the ioctl commands get dispatched to functions with this
424 * prototype.
425 */
426 typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size);
427
428 static int remove_all(struct dm_ioctl *param, size_t param_size)
429 {
430 dm_hash_remove_all(1);
431 param->data_size = 0;
432 return 0;
433 }
434
435 /*
436 * Round up the ptr to an 8-byte boundary.
437 */
438 #define ALIGN_MASK 7
439 static inline void *align_ptr(void *ptr)
440 {
441 return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK);
442 }
443
444 /*
445 * Retrieves the data payload buffer from an already allocated
446 * struct dm_ioctl.
447 */
448 static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
449 size_t *len)
450 {
451 param->data_start = align_ptr(param + 1) - (void *) param;
452
453 if (param->data_start < param_size)
454 *len = param_size - param->data_start;
455 else
456 *len = 0;
457
458 return ((void *) param) + param->data_start;
459 }
460
461 static int list_devices(struct dm_ioctl *param, size_t param_size)
462 {
463 unsigned int i;
464 struct hash_cell *hc;
465 size_t len, needed = 0;
466 struct gendisk *disk;
467 struct dm_name_list *nl, *old_nl = NULL;
468
469 down_write(&_hash_lock);
470
471 /*
472 * Loop through all the devices working out how much
473 * space we need.
474 */
475 for (i = 0; i < NUM_BUCKETS; i++) {
476 list_for_each_entry (hc, _name_buckets + i, name_list) {
477 needed += sizeof(struct dm_name_list);
478 needed += strlen(hc->name) + 1;
479 needed += ALIGN_MASK;
480 }
481 }
482
483 /*
484 * Grab our output buffer.
485 */
486 nl = get_result_buffer(param, param_size, &len);
487 if (len < needed) {
488 param->flags |= DM_BUFFER_FULL_FLAG;
489 goto out;
490 }
491 param->data_size = param->data_start + needed;
492
493 nl->dev = 0; /* Flags no data */
494
495 /*
496 * Now loop through filling out the names.
497 */
498 for (i = 0; i < NUM_BUCKETS; i++) {
499 list_for_each_entry (hc, _name_buckets + i, name_list) {
500 if (old_nl)
501 old_nl->next = (uint32_t) ((void *) nl -
502 (void *) old_nl);
503 disk = dm_disk(hc->md);
504 nl->dev = huge_encode_dev(disk_devt(disk));
505 nl->next = 0;
506 strcpy(nl->name, hc->name);
507
508 old_nl = nl;
509 nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1);
510 }
511 }
512
513 out:
514 up_write(&_hash_lock);
515 return 0;
516 }
517
518 static void list_version_get_needed(struct target_type *tt, void *needed_param)
519 {
520 size_t *needed = needed_param;
521
522 *needed += sizeof(struct dm_target_versions);
523 *needed += strlen(tt->name);
524 *needed += ALIGN_MASK;
525 }
526
527 static void list_version_get_info(struct target_type *tt, void *param)
528 {
529 struct vers_iter *info = param;
530
531 /* Check space - it might have changed since the first iteration */
532 if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
533 info->end) {
534
535 info->flags = DM_BUFFER_FULL_FLAG;
536 return;
537 }
538
539 if (info->old_vers)
540 info->old_vers->next = (uint32_t) ((void *)info->vers -
541 (void *)info->old_vers);
542 info->vers->version[0] = tt->version[0];
543 info->vers->version[1] = tt->version[1];
544 info->vers->version[2] = tt->version[2];
545 info->vers->next = 0;
546 strcpy(info->vers->name, tt->name);
547
548 info->old_vers = info->vers;
549 info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
550 }
551
552 static int list_versions(struct dm_ioctl *param, size_t param_size)
553 {
554 size_t len, needed = 0;
555 struct dm_target_versions *vers;
556 struct vers_iter iter_info;
557
558 /*
559 * Loop through all the devices working out how much
560 * space we need.
561 */
562 dm_target_iterate(list_version_get_needed, &needed);
563
564 /*
565 * Grab our output buffer.
566 */
567 vers = get_result_buffer(param, param_size, &len);
568 if (len < needed) {
569 param->flags |= DM_BUFFER_FULL_FLAG;
570 goto out;
571 }
572 param->data_size = param->data_start + needed;
573
574 iter_info.param_size = param_size;
575 iter_info.old_vers = NULL;
576 iter_info.vers = vers;
577 iter_info.flags = 0;
578 iter_info.end = (char *)vers+len;
579
580 /*
581 * Now loop through filling out the names & versions.
582 */
583 dm_target_iterate(list_version_get_info, &iter_info);
584 param->flags |= iter_info.flags;
585
586 out:
587 return 0;
588 }
589
590 static int check_name(const char *name)
591 {
592 if (strchr(name, '/')) {
593 DMWARN("invalid device name");
594 return -EINVAL;
595 }
596
597 return 0;
598 }
599
600 /*
601 * On successful return, the caller must not attempt to acquire
602 * _hash_lock without first calling dm_table_put, because dm_table_destroy
603 * waits for this dm_table_put and could be called under this lock.
604 */
605 static struct dm_table *dm_get_inactive_table(struct mapped_device *md)
606 {
607 struct hash_cell *hc;
608 struct dm_table *table = NULL;
609
610 down_read(&_hash_lock);
611 hc = dm_get_mdptr(md);
612 if (!hc || hc->md != md) {
613 DMWARN("device has been removed from the dev hash table.");
614 goto out;
615 }
616
617 table = hc->new_map;
618 if (table)
619 dm_table_get(table);
620
621 out:
622 up_read(&_hash_lock);
623
624 return table;
625 }
626
627 static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
628 struct dm_ioctl *param)
629 {
630 return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
631 dm_get_inactive_table(md) : dm_get_live_table(md);
632 }
633
634 /*
635 * Fills in a dm_ioctl structure, ready for sending back to
636 * userland.
637 */
638 static void __dev_status(struct mapped_device *md, struct dm_ioctl *param)
639 {
640 struct gendisk *disk = dm_disk(md);
641 struct dm_table *table;
642
643 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
644 DM_ACTIVE_PRESENT_FLAG);
645
646 if (dm_suspended_md(md))
647 param->flags |= DM_SUSPEND_FLAG;
648
649 param->dev = huge_encode_dev(disk_devt(disk));
650
651 /*
652 * Yes, this will be out of date by the time it gets back
653 * to userland, but it is still very useful for
654 * debugging.
655 */
656 param->open_count = dm_open_count(md);
657
658 param->event_nr = dm_get_event_nr(md);
659 param->target_count = 0;
660
661 table = dm_get_live_table(md);
662 if (table) {
663 if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
664 if (get_disk_ro(disk))
665 param->flags |= DM_READONLY_FLAG;
666 param->target_count = dm_table_get_num_targets(table);
667 }
668 dm_table_put(table);
669
670 param->flags |= DM_ACTIVE_PRESENT_FLAG;
671 }
672
673 if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
674 table = dm_get_inactive_table(md);
675 if (table) {
676 if (!(dm_table_get_mode(table) & FMODE_WRITE))
677 param->flags |= DM_READONLY_FLAG;
678 param->target_count = dm_table_get_num_targets(table);
679 dm_table_put(table);
680 }
681 }
682 }
683
684 static int dev_create(struct dm_ioctl *param, size_t param_size)
685 {
686 int r, m = DM_ANY_MINOR;
687 struct mapped_device *md;
688
689 r = check_name(param->name);
690 if (r)
691 return r;
692
693 if (param->flags & DM_PERSISTENT_DEV_FLAG)
694 m = MINOR(huge_decode_dev(param->dev));
695
696 r = dm_create(m, &md);
697 if (r)
698 return r;
699
700 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
701 if (r) {
702 dm_put(md);
703 dm_destroy(md);
704 return r;
705 }
706
707 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
708
709 __dev_status(md, param);
710
711 dm_put(md);
712
713 return 0;
714 }
715
716 /*
717 * Always use UUID for lookups if it's present, otherwise use name or dev.
718 */
719 static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
720 {
721 struct mapped_device *md;
722 void *mdptr = NULL;
723
724 if (*param->uuid)
725 return __get_uuid_cell(param->uuid);
726
727 if (*param->name)
728 return __get_name_cell(param->name);
729
730 md = dm_get_md(huge_decode_dev(param->dev));
731 if (!md)
732 goto out;
733
734 mdptr = dm_get_mdptr(md);
735 if (!mdptr)
736 dm_put(md);
737
738 out:
739 return mdptr;
740 }
741
742 static struct mapped_device *find_device(struct dm_ioctl *param)
743 {
744 struct hash_cell *hc;
745 struct mapped_device *md = NULL;
746
747 down_read(&_hash_lock);
748 hc = __find_device_hash_cell(param);
749 if (hc) {
750 md = hc->md;
751
752 /*
753 * Sneakily write in both the name and the uuid
754 * while we have the cell.
755 */
756 strlcpy(param->name, hc->name, sizeof(param->name));
757 if (hc->uuid)
758 strlcpy(param->uuid, hc->uuid, sizeof(param->uuid));
759 else
760 param->uuid[0] = '\0';
761
762 if (hc->new_map)
763 param->flags |= DM_INACTIVE_PRESENT_FLAG;
764 else
765 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
766 }
767 up_read(&_hash_lock);
768
769 return md;
770 }
771
772 static int dev_remove(struct dm_ioctl *param, size_t param_size)
773 {
774 struct hash_cell *hc;
775 struct mapped_device *md;
776 int r;
777
778 down_write(&_hash_lock);
779 hc = __find_device_hash_cell(param);
780
781 if (!hc) {
782 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
783 up_write(&_hash_lock);
784 return -ENXIO;
785 }
786
787 md = hc->md;
788
789 /*
790 * Ensure the device is not open and nothing further can open it.
791 */
792 r = dm_lock_for_deletion(md);
793 if (r) {
794 DMDEBUG_LIMIT("unable to remove open device %s", hc->name);
795 up_write(&_hash_lock);
796 dm_put(md);
797 return r;
798 }
799
800 __hash_remove(hc);
801 up_write(&_hash_lock);
802
803 if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr))
804 param->flags |= DM_UEVENT_GENERATED_FLAG;
805
806 dm_put(md);
807 dm_destroy(md);
808 return 0;
809 }
810
811 /*
812 * Check a string doesn't overrun the chunk of
813 * memory we copied from userland.
814 */
815 static int invalid_str(char *str, void *end)
816 {
817 while ((void *) str < end)
818 if (!*str++)
819 return 0;
820
821 return -EINVAL;
822 }
823
824 static int dev_rename(struct dm_ioctl *param, size_t param_size)
825 {
826 int r;
827 char *new_data = (char *) param + param->data_start;
828 struct mapped_device *md;
829 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
830
831 if (new_data < param->data ||
832 invalid_str(new_data, (void *) param + param_size) ||
833 strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
834 DMWARN("Invalid new mapped device name or uuid string supplied.");
835 return -EINVAL;
836 }
837
838 if (!change_uuid) {
839 r = check_name(new_data);
840 if (r)
841 return r;
842 }
843
844 md = dm_hash_rename(param, new_data);
845 if (IS_ERR(md))
846 return PTR_ERR(md);
847
848 __dev_status(md, param);
849 dm_put(md);
850
851 return 0;
852 }
853
854 static int dev_set_geometry(struct dm_ioctl *param, size_t param_size)
855 {
856 int r = -EINVAL, x;
857 struct mapped_device *md;
858 struct hd_geometry geometry;
859 unsigned long indata[4];
860 char *geostr = (char *) param + param->data_start;
861
862 md = find_device(param);
863 if (!md)
864 return -ENXIO;
865
866 if (geostr < param->data ||
867 invalid_str(geostr, (void *) param + param_size)) {
868 DMWARN("Invalid geometry supplied.");
869 goto out;
870 }
871
872 x = sscanf(geostr, "%lu %lu %lu %lu", indata,
873 indata + 1, indata + 2, indata + 3);
874
875 if (x != 4) {
876 DMWARN("Unable to interpret geometry settings.");
877 goto out;
878 }
879
880 if (indata[0] > 65535 || indata[1] > 255 ||
881 indata[2] > 255 || indata[3] > ULONG_MAX) {
882 DMWARN("Geometry exceeds range limits.");
883 goto out;
884 }
885
886 geometry.cylinders = indata[0];
887 geometry.heads = indata[1];
888 geometry.sectors = indata[2];
889 geometry.start = indata[3];
890
891 r = dm_set_geometry(md, &geometry);
892
893 param->data_size = 0;
894
895 out:
896 dm_put(md);
897 return r;
898 }
899
900 static int do_suspend(struct dm_ioctl *param)
901 {
902 int r = 0;
903 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
904 struct mapped_device *md;
905
906 md = find_device(param);
907 if (!md)
908 return -ENXIO;
909
910 if (param->flags & DM_SKIP_LOCKFS_FLAG)
911 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
912 if (param->flags & DM_NOFLUSH_FLAG)
913 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
914
915 if (!dm_suspended_md(md)) {
916 r = dm_suspend(md, suspend_flags);
917 if (r)
918 goto out;
919 }
920
921 __dev_status(md, param);
922
923 out:
924 dm_put(md);
925
926 return r;
927 }
928
929 static int do_resume(struct dm_ioctl *param)
930 {
931 int r = 0;
932 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
933 struct hash_cell *hc;
934 struct mapped_device *md;
935 struct dm_table *new_map, *old_map = NULL;
936
937 down_write(&_hash_lock);
938
939 hc = __find_device_hash_cell(param);
940 if (!hc) {
941 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
942 up_write(&_hash_lock);
943 return -ENXIO;
944 }
945
946 md = hc->md;
947
948 new_map = hc->new_map;
949 hc->new_map = NULL;
950 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
951
952 up_write(&_hash_lock);
953
954 /* Do we need to load a new map ? */
955 if (new_map) {
956 /* Suspend if it isn't already suspended */
957 if (param->flags & DM_SKIP_LOCKFS_FLAG)
958 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
959 if (param->flags & DM_NOFLUSH_FLAG)
960 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
961 if (!dm_suspended_md(md))
962 dm_suspend(md, suspend_flags);
963
964 old_map = dm_swap_table(md, new_map);
965 if (IS_ERR(old_map)) {
966 dm_table_destroy(new_map);
967 dm_put(md);
968 return PTR_ERR(old_map);
969 }
970
971 if (dm_table_get_mode(new_map) & FMODE_WRITE)
972 set_disk_ro(dm_disk(md), 0);
973 else
974 set_disk_ro(dm_disk(md), 1);
975 }
976
977 if (dm_suspended_md(md)) {
978 r = dm_resume(md);
979 if (!r && !dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr))
980 param->flags |= DM_UEVENT_GENERATED_FLAG;
981 }
982
983 if (old_map)
984 dm_table_destroy(old_map);
985
986 if (!r)
987 __dev_status(md, param);
988
989 dm_put(md);
990 return r;
991 }
992
993 /*
994 * Set or unset the suspension state of a device.
995 * If the device already is in the requested state we just return its status.
996 */
997 static int dev_suspend(struct dm_ioctl *param, size_t param_size)
998 {
999 if (param->flags & DM_SUSPEND_FLAG)
1000 return do_suspend(param);
1001
1002 return do_resume(param);
1003 }
1004
1005 /*
1006 * Copies device info back to user space, used by
1007 * the create and info ioctls.
1008 */
1009 static int dev_status(struct dm_ioctl *param, size_t param_size)
1010 {
1011 struct mapped_device *md;
1012
1013 md = find_device(param);
1014 if (!md)
1015 return -ENXIO;
1016
1017 __dev_status(md, param);
1018 dm_put(md);
1019
1020 return 0;
1021 }
1022
1023 /*
1024 * Build up the status struct for each target
1025 */
1026 static void retrieve_status(struct dm_table *table,
1027 struct dm_ioctl *param, size_t param_size)
1028 {
1029 unsigned int i, num_targets;
1030 struct dm_target_spec *spec;
1031 char *outbuf, *outptr;
1032 status_type_t type;
1033 size_t remaining, len, used = 0;
1034
1035 outptr = outbuf = get_result_buffer(param, param_size, &len);
1036
1037 if (param->flags & DM_STATUS_TABLE_FLAG)
1038 type = STATUSTYPE_TABLE;
1039 else
1040 type = STATUSTYPE_INFO;
1041
1042 /* Get all the target info */
1043 num_targets = dm_table_get_num_targets(table);
1044 for (i = 0; i < num_targets; i++) {
1045 struct dm_target *ti = dm_table_get_target(table, i);
1046
1047 remaining = len - (outptr - outbuf);
1048 if (remaining <= sizeof(struct dm_target_spec)) {
1049 param->flags |= DM_BUFFER_FULL_FLAG;
1050 break;
1051 }
1052
1053 spec = (struct dm_target_spec *) outptr;
1054
1055 spec->status = 0;
1056 spec->sector_start = ti->begin;
1057 spec->length = ti->len;
1058 strncpy(spec->target_type, ti->type->name,
1059 sizeof(spec->target_type));
1060
1061 outptr += sizeof(struct dm_target_spec);
1062 remaining = len - (outptr - outbuf);
1063 if (remaining <= 0) {
1064 param->flags |= DM_BUFFER_FULL_FLAG;
1065 break;
1066 }
1067
1068 /* Get the status/table string from the target driver */
1069 if (ti->type->status) {
1070 if (ti->type->status(ti, type, outptr, remaining)) {
1071 param->flags |= DM_BUFFER_FULL_FLAG;
1072 break;
1073 }
1074 } else
1075 outptr[0] = '\0';
1076
1077 outptr += strlen(outptr) + 1;
1078 used = param->data_start + (outptr - outbuf);
1079
1080 outptr = align_ptr(outptr);
1081 spec->next = outptr - outbuf;
1082 }
1083
1084 if (used)
1085 param->data_size = used;
1086
1087 param->target_count = num_targets;
1088 }
1089
1090 /*
1091 * Wait for a device to report an event
1092 */
1093 static int dev_wait(struct dm_ioctl *param, size_t param_size)
1094 {
1095 int r = 0;
1096 struct mapped_device *md;
1097 struct dm_table *table;
1098
1099 md = find_device(param);
1100 if (!md)
1101 return -ENXIO;
1102
1103 /*
1104 * Wait for a notification event
1105 */
1106 if (dm_wait_event(md, param->event_nr)) {
1107 r = -ERESTARTSYS;
1108 goto out;
1109 }
1110
1111 /*
1112 * The userland program is going to want to know what
1113 * changed to trigger the event, so we may as well tell
1114 * him and save an ioctl.
1115 */
1116 __dev_status(md, param);
1117
1118 table = dm_get_live_or_inactive_table(md, param);
1119 if (table) {
1120 retrieve_status(table, param, param_size);
1121 dm_table_put(table);
1122 }
1123
1124 out:
1125 dm_put(md);
1126
1127 return r;
1128 }
1129
1130 static inline fmode_t get_mode(struct dm_ioctl *param)
1131 {
1132 fmode_t mode = FMODE_READ | FMODE_WRITE;
1133
1134 if (param->flags & DM_READONLY_FLAG)
1135 mode = FMODE_READ;
1136
1137 return mode;
1138 }
1139
1140 static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
1141 struct dm_target_spec **spec, char **target_params)
1142 {
1143 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1144 *target_params = (char *) (*spec + 1);
1145
1146 if (*spec < (last + 1))
1147 return -EINVAL;
1148
1149 return invalid_str(*target_params, end);
1150 }
1151
1152 static int populate_table(struct dm_table *table,
1153 struct dm_ioctl *param, size_t param_size)
1154 {
1155 int r;
1156 unsigned int i = 0;
1157 struct dm_target_spec *spec = (struct dm_target_spec *) param;
1158 uint32_t next = param->data_start;
1159 void *end = (void *) param + param_size;
1160 char *target_params;
1161
1162 if (!param->target_count) {
1163 DMWARN("populate_table: no targets specified");
1164 return -EINVAL;
1165 }
1166
1167 for (i = 0; i < param->target_count; i++) {
1168
1169 r = next_target(spec, next, end, &spec, &target_params);
1170 if (r) {
1171 DMWARN("unable to find target");
1172 return r;
1173 }
1174
1175 r = dm_table_add_target(table, spec->target_type,
1176 (sector_t) spec->sector_start,
1177 (sector_t) spec->length,
1178 target_params);
1179 if (r) {
1180 DMWARN("error adding target to table");
1181 return r;
1182 }
1183
1184 next = spec->next;
1185 }
1186
1187 return dm_table_complete(table);
1188 }
1189
1190 static int table_load(struct dm_ioctl *param, size_t param_size)
1191 {
1192 int r;
1193 struct hash_cell *hc;
1194 struct dm_table *t;
1195 struct mapped_device *md;
1196
1197 md = find_device(param);
1198 if (!md)
1199 return -ENXIO;
1200
1201 r = dm_table_create(&t, get_mode(param), param->target_count, md);
1202 if (r)
1203 goto out;
1204
1205 r = populate_table(t, param, param_size);
1206 if (r) {
1207 dm_table_destroy(t);
1208 goto out;
1209 }
1210
1211 /* Protect md->type and md->queue against concurrent table loads. */
1212 dm_lock_md_type(md);
1213 if (dm_get_md_type(md) == DM_TYPE_NONE)
1214 /* Initial table load: acquire type of table. */
1215 dm_set_md_type(md, dm_table_get_type(t));
1216 else if (dm_get_md_type(md) != dm_table_get_type(t)) {
1217 DMWARN("can't change device type after initial table load.");
1218 dm_table_destroy(t);
1219 dm_unlock_md_type(md);
1220 r = -EINVAL;
1221 goto out;
1222 }
1223
1224 /* setup md->queue to reflect md's type (may block) */
1225 r = dm_setup_md_queue(md);
1226 if (r) {
1227 DMWARN("unable to set up device queue for new table.");
1228 dm_table_destroy(t);
1229 dm_unlock_md_type(md);
1230 goto out;
1231 }
1232 dm_unlock_md_type(md);
1233
1234 /* stage inactive table */
1235 down_write(&_hash_lock);
1236 hc = dm_get_mdptr(md);
1237 if (!hc || hc->md != md) {
1238 DMWARN("device has been removed from the dev hash table.");
1239 dm_table_destroy(t);
1240 up_write(&_hash_lock);
1241 r = -ENXIO;
1242 goto out;
1243 }
1244
1245 if (hc->new_map)
1246 dm_table_destroy(hc->new_map);
1247 hc->new_map = t;
1248 up_write(&_hash_lock);
1249
1250 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1251 __dev_status(md, param);
1252
1253 out:
1254 dm_put(md);
1255
1256 return r;
1257 }
1258
1259 static int table_clear(struct dm_ioctl *param, size_t param_size)
1260 {
1261 struct hash_cell *hc;
1262 struct mapped_device *md;
1263
1264 down_write(&_hash_lock);
1265
1266 hc = __find_device_hash_cell(param);
1267 if (!hc) {
1268 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1269 up_write(&_hash_lock);
1270 return -ENXIO;
1271 }
1272
1273 if (hc->new_map) {
1274 dm_table_destroy(hc->new_map);
1275 hc->new_map = NULL;
1276 }
1277
1278 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1279
1280 __dev_status(hc->md, param);
1281 md = hc->md;
1282 up_write(&_hash_lock);
1283 dm_put(md);
1284
1285 return 0;
1286 }
1287
1288 /*
1289 * Retrieves a list of devices used by a particular dm device.
1290 */
1291 static void retrieve_deps(struct dm_table *table,
1292 struct dm_ioctl *param, size_t param_size)
1293 {
1294 unsigned int count = 0;
1295 struct list_head *tmp;
1296 size_t len, needed;
1297 struct dm_dev_internal *dd;
1298 struct dm_target_deps *deps;
1299
1300 deps = get_result_buffer(param, param_size, &len);
1301
1302 /*
1303 * Count the devices.
1304 */
1305 list_for_each (tmp, dm_table_get_devices(table))
1306 count++;
1307
1308 /*
1309 * Check we have enough space.
1310 */
1311 needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
1312 if (len < needed) {
1313 param->flags |= DM_BUFFER_FULL_FLAG;
1314 return;
1315 }
1316
1317 /*
1318 * Fill in the devices.
1319 */
1320 deps->count = count;
1321 count = 0;
1322 list_for_each_entry (dd, dm_table_get_devices(table), list)
1323 deps->dev[count++] = huge_encode_dev(dd->dm_dev.bdev->bd_dev);
1324
1325 param->data_size = param->data_start + needed;
1326 }
1327
1328 static int table_deps(struct dm_ioctl *param, size_t param_size)
1329 {
1330 struct mapped_device *md;
1331 struct dm_table *table;
1332
1333 md = find_device(param);
1334 if (!md)
1335 return -ENXIO;
1336
1337 __dev_status(md, param);
1338
1339 table = dm_get_live_or_inactive_table(md, param);
1340 if (table) {
1341 retrieve_deps(table, param, param_size);
1342 dm_table_put(table);
1343 }
1344
1345 dm_put(md);
1346
1347 return 0;
1348 }
1349
1350 /*
1351 * Return the status of a device as a text string for each
1352 * target.
1353 */
1354 static int table_status(struct dm_ioctl *param, size_t param_size)
1355 {
1356 struct mapped_device *md;
1357 struct dm_table *table;
1358
1359 md = find_device(param);
1360 if (!md)
1361 return -ENXIO;
1362
1363 __dev_status(md, param);
1364
1365 table = dm_get_live_or_inactive_table(md, param);
1366 if (table) {
1367 retrieve_status(table, param, param_size);
1368 dm_table_put(table);
1369 }
1370
1371 dm_put(md);
1372
1373 return 0;
1374 }
1375
1376 /*
1377 * Pass a message to the target that's at the supplied device offset.
1378 */
1379 static int target_message(struct dm_ioctl *param, size_t param_size)
1380 {
1381 int r, argc;
1382 char **argv;
1383 struct mapped_device *md;
1384 struct dm_table *table;
1385 struct dm_target *ti;
1386 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1387
1388 md = find_device(param);
1389 if (!md)
1390 return -ENXIO;
1391
1392 if (tmsg < (struct dm_target_msg *) param->data ||
1393 invalid_str(tmsg->message, (void *) param + param_size)) {
1394 DMWARN("Invalid target message parameters.");
1395 r = -EINVAL;
1396 goto out;
1397 }
1398
1399 r = dm_split_args(&argc, &argv, tmsg->message);
1400 if (r) {
1401 DMWARN("Failed to split target message parameters");
1402 goto out;
1403 }
1404
1405 table = dm_get_live_table(md);
1406 if (!table)
1407 goto out_argv;
1408
1409 if (dm_deleting_md(md)) {
1410 r = -ENXIO;
1411 goto out_table;
1412 }
1413
1414 ti = dm_table_find_target(table, tmsg->sector);
1415 if (!dm_target_is_valid(ti)) {
1416 DMWARN("Target message sector outside device.");
1417 r = -EINVAL;
1418 } else if (ti->type->message)
1419 r = ti->type->message(ti, argc, argv);
1420 else {
1421 DMWARN("Target type does not support messages");
1422 r = -EINVAL;
1423 }
1424
1425 out_table:
1426 dm_table_put(table);
1427 out_argv:
1428 kfree(argv);
1429 out:
1430 param->data_size = 0;
1431 dm_put(md);
1432 return r;
1433 }
1434
1435 /*-----------------------------------------------------------------
1436 * Implementation of open/close/ioctl on the special char
1437 * device.
1438 *---------------------------------------------------------------*/
1439 static ioctl_fn lookup_ioctl(unsigned int cmd)
1440 {
1441 static struct {
1442 int cmd;
1443 ioctl_fn fn;
1444 } _ioctls[] = {
1445 {DM_VERSION_CMD, NULL}, /* version is dealt with elsewhere */
1446 {DM_REMOVE_ALL_CMD, remove_all},
1447 {DM_LIST_DEVICES_CMD, list_devices},
1448
1449 {DM_DEV_CREATE_CMD, dev_create},
1450 {DM_DEV_REMOVE_CMD, dev_remove},
1451 {DM_DEV_RENAME_CMD, dev_rename},
1452 {DM_DEV_SUSPEND_CMD, dev_suspend},
1453 {DM_DEV_STATUS_CMD, dev_status},
1454 {DM_DEV_WAIT_CMD, dev_wait},
1455
1456 {DM_TABLE_LOAD_CMD, table_load},
1457 {DM_TABLE_CLEAR_CMD, table_clear},
1458 {DM_TABLE_DEPS_CMD, table_deps},
1459 {DM_TABLE_STATUS_CMD, table_status},
1460
1461 {DM_LIST_VERSIONS_CMD, list_versions},
1462
1463 {DM_TARGET_MSG_CMD, target_message},
1464 {DM_DEV_SET_GEOMETRY_CMD, dev_set_geometry}
1465 };
1466
1467 return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn;
1468 }
1469
1470 /*
1471 * As well as checking the version compatibility this always
1472 * copies the kernel interface version out.
1473 */
1474 static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1475 {
1476 uint32_t version[3];
1477 int r = 0;
1478
1479 if (copy_from_user(version, user->version, sizeof(version)))
1480 return -EFAULT;
1481
1482 if ((DM_VERSION_MAJOR != version[0]) ||
1483 (DM_VERSION_MINOR < version[1])) {
1484 DMWARN("ioctl interface mismatch: "
1485 "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1486 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1487 DM_VERSION_PATCHLEVEL,
1488 version[0], version[1], version[2], cmd);
1489 r = -EINVAL;
1490 }
1491
1492 /*
1493 * Fill in the kernel version.
1494 */
1495 version[0] = DM_VERSION_MAJOR;
1496 version[1] = DM_VERSION_MINOR;
1497 version[2] = DM_VERSION_PATCHLEVEL;
1498 if (copy_to_user(user->version, version, sizeof(version)))
1499 return -EFAULT;
1500
1501 return r;
1502 }
1503
1504 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
1505 {
1506 struct dm_ioctl tmp, *dmi;
1507 int secure_data;
1508
1509 if (copy_from_user(&tmp, user, sizeof(tmp) - sizeof(tmp.data)))
1510 return -EFAULT;
1511
1512 if (tmp.data_size < (sizeof(tmp) - sizeof(tmp.data)))
1513 return -EINVAL;
1514
1515 secure_data = tmp.flags & DM_SECURE_DATA_FLAG;
1516
1517 dmi = vmalloc(tmp.data_size);
1518 if (!dmi) {
1519 if (secure_data && clear_user(user, tmp.data_size))
1520 return -EFAULT;
1521 return -ENOMEM;
1522 }
1523
1524 if (copy_from_user(dmi, user, tmp.data_size))
1525 goto bad;
1526
1527 /* Wipe the user buffer so we do not return it to userspace */
1528 if (secure_data && clear_user(user, tmp.data_size))
1529 goto bad;
1530
1531 *param = dmi;
1532 return 0;
1533
1534 bad:
1535 if (secure_data)
1536 memset(dmi, 0, tmp.data_size);
1537 vfree(dmi);
1538 return -EFAULT;
1539 }
1540
1541 static int validate_params(uint cmd, struct dm_ioctl *param)
1542 {
1543 /* Always clear this flag */
1544 param->flags &= ~DM_BUFFER_FULL_FLAG;
1545 param->flags &= ~DM_UEVENT_GENERATED_FLAG;
1546 param->flags &= ~DM_SECURE_DATA_FLAG;
1547
1548 /* Ignores parameters */
1549 if (cmd == DM_REMOVE_ALL_CMD ||
1550 cmd == DM_LIST_DEVICES_CMD ||
1551 cmd == DM_LIST_VERSIONS_CMD)
1552 return 0;
1553
1554 if ((cmd == DM_DEV_CREATE_CMD)) {
1555 if (!*param->name) {
1556 DMWARN("name not supplied when creating device");
1557 return -EINVAL;
1558 }
1559 } else if ((*param->uuid && *param->name)) {
1560 DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
1561 return -EINVAL;
1562 }
1563
1564 /* Ensure strings are terminated */
1565 param->name[DM_NAME_LEN - 1] = '\0';
1566 param->uuid[DM_UUID_LEN - 1] = '\0';
1567
1568 return 0;
1569 }
1570
1571 static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
1572 {
1573 int r = 0;
1574 int wipe_buffer;
1575 unsigned int cmd;
1576 struct dm_ioctl *uninitialized_var(param);
1577 ioctl_fn fn = NULL;
1578 size_t input_param_size;
1579
1580 /* only root can play with this */
1581 if (!capable(CAP_SYS_ADMIN))
1582 return -EACCES;
1583
1584 if (_IOC_TYPE(command) != DM_IOCTL)
1585 return -ENOTTY;
1586
1587 cmd = _IOC_NR(command);
1588
1589 /*
1590 * Check the interface version passed in. This also
1591 * writes out the kernel's interface version.
1592 */
1593 r = check_version(cmd, user);
1594 if (r)
1595 return r;
1596
1597 /*
1598 * Nothing more to do for the version command.
1599 */
1600 if (cmd == DM_VERSION_CMD)
1601 return 0;
1602
1603 fn = lookup_ioctl(cmd);
1604 if (!fn) {
1605 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1606 return -ENOTTY;
1607 }
1608
1609 /*
1610 * Trying to avoid low memory issues when a device is
1611 * suspended.
1612 */
1613 current->flags |= PF_MEMALLOC;
1614
1615 /*
1616 * Copy the parameters into kernel space.
1617 */
1618 r = copy_params(user, &param);
1619
1620 current->flags &= ~PF_MEMALLOC;
1621
1622 if (r)
1623 return r;
1624
1625 input_param_size = param->data_size;
1626 wipe_buffer = param->flags & DM_SECURE_DATA_FLAG;
1627
1628 r = validate_params(cmd, param);
1629 if (r)
1630 goto out;
1631
1632 param->data_size = sizeof(*param);
1633 r = fn(param, input_param_size);
1634
1635 /*
1636 * Copy the results back to userland.
1637 */
1638 if (!r && copy_to_user(user, param, param->data_size))
1639 r = -EFAULT;
1640
1641 out:
1642 if (wipe_buffer)
1643 memset(param, 0, input_param_size);
1644
1645 vfree(param);
1646 return r;
1647 }
1648
1649 static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
1650 {
1651 return (long)ctl_ioctl(command, (struct dm_ioctl __user *)u);
1652 }
1653
1654 #ifdef CONFIG_COMPAT
1655 static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
1656 {
1657 return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
1658 }
1659 #else
1660 #define dm_compat_ctl_ioctl NULL
1661 #endif
1662
1663 static const struct file_operations _ctl_fops = {
1664 .open = nonseekable_open,
1665 .unlocked_ioctl = dm_ctl_ioctl,
1666 .compat_ioctl = dm_compat_ctl_ioctl,
1667 .owner = THIS_MODULE,
1668 .llseek = noop_llseek,
1669 };
1670
1671 static struct miscdevice _dm_misc = {
1672 .minor = MAPPER_CTRL_MINOR,
1673 .name = DM_NAME,
1674 .nodename = DM_DIR "/" DM_CONTROL_NODE,
1675 .fops = &_ctl_fops
1676 };
1677
1678 MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
1679 MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
1680
1681 /*
1682 * Create misc character device and link to DM_DIR/control.
1683 */
1684 int __init dm_interface_init(void)
1685 {
1686 int r;
1687
1688 r = dm_hash_init();
1689 if (r)
1690 return r;
1691
1692 r = misc_register(&_dm_misc);
1693 if (r) {
1694 DMERR("misc_register failed for control device");
1695 dm_hash_exit();
1696 return r;
1697 }
1698
1699 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
1700 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
1701 DM_DRIVER_EMAIL);
1702 return 0;
1703 }
1704
1705 void dm_interface_exit(void)
1706 {
1707 if (misc_deregister(&_dm_misc) < 0)
1708 DMERR("misc_deregister failed for control device");
1709
1710 dm_hash_exit();
1711 }
1712
1713 /**
1714 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
1715 * @md: Pointer to mapped_device
1716 * @name: Buffer (size DM_NAME_LEN) for name
1717 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
1718 */
1719 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
1720 {
1721 int r = 0;
1722 struct hash_cell *hc;
1723
1724 if (!md)
1725 return -ENXIO;
1726
1727 mutex_lock(&dm_hash_cells_mutex);
1728 hc = dm_get_mdptr(md);
1729 if (!hc || hc->md != md) {
1730 r = -ENXIO;
1731 goto out;
1732 }
1733
1734 if (name)
1735 strcpy(name, hc->name);
1736 if (uuid)
1737 strcpy(uuid, hc->uuid ? : "");
1738
1739 out:
1740 mutex_unlock(&dm_hash_cells_mutex);
1741
1742 return r;
1743 }
x86 "subsystem" repository