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dm thin metadata: factor out __write_initial_superblock
[linux/fpc-iii.git] / drivers / md / dm-ioctl.c
bloba1a3e6df17b82624490952b0c91f94a9ea1e1f86
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 char dummy;
884
885 md = find_device(param);
886 if (!md)
887 return -ENXIO;
888
889 if (geostr < param->data ||
890 invalid_str(geostr, (void *) param + param_size)) {
891 DMWARN("Invalid geometry supplied.");
892 goto out;
893 }
894
895 x = sscanf(geostr, "%lu %lu %lu %lu%c", indata,
896 indata + 1, indata + 2, indata + 3, &dummy);
897
898 if (x != 4) {
899 DMWARN("Unable to interpret geometry settings.");
900 goto out;
901 }
902
903 if (indata[0] > 65535 || indata[1] > 255 ||
904 indata[2] > 255 || indata[3] > ULONG_MAX) {
905 DMWARN("Geometry exceeds range limits.");
906 goto out;
907 }
908
909 geometry.cylinders = indata[0];
910 geometry.heads = indata[1];
911 geometry.sectors = indata[2];
912 geometry.start = indata[3];
913
914 r = dm_set_geometry(md, &geometry);
915
916 param->data_size = 0;
917
918 out:
919 dm_put(md);
920 return r;
921 }
922
923 static int do_suspend(struct dm_ioctl *param)
924 {
925 int r = 0;
926 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
927 struct mapped_device *md;
928
929 md = find_device(param);
930 if (!md)
931 return -ENXIO;
932
933 if (param->flags & DM_SKIP_LOCKFS_FLAG)
934 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
935 if (param->flags & DM_NOFLUSH_FLAG)
936 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
937
938 if (!dm_suspended_md(md)) {
939 r = dm_suspend(md, suspend_flags);
940 if (r)
941 goto out;
942 }
943
944 __dev_status(md, param);
945
946 out:
947 dm_put(md);
948
949 return r;
950 }
951
952 static int do_resume(struct dm_ioctl *param)
953 {
954 int r = 0;
955 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
956 struct hash_cell *hc;
957 struct mapped_device *md;
958 struct dm_table *new_map, *old_map = NULL;
959
960 down_write(&_hash_lock);
961
962 hc = __find_device_hash_cell(param);
963 if (!hc) {
964 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
965 up_write(&_hash_lock);
966 return -ENXIO;
967 }
968
969 md = hc->md;
970
971 new_map = hc->new_map;
972 hc->new_map = NULL;
973 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
974
975 up_write(&_hash_lock);
976
977 /* Do we need to load a new map ? */
978 if (new_map) {
979 /* Suspend if it isn't already suspended */
980 if (param->flags & DM_SKIP_LOCKFS_FLAG)
981 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
982 if (param->flags & DM_NOFLUSH_FLAG)
983 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
984 if (!dm_suspended_md(md))
985 dm_suspend(md, suspend_flags);
986
987 old_map = dm_swap_table(md, new_map);
988 if (IS_ERR(old_map)) {
989 dm_table_destroy(new_map);
990 dm_put(md);
991 return PTR_ERR(old_map);
992 }
993
994 if (dm_table_get_mode(new_map) & FMODE_WRITE)
995 set_disk_ro(dm_disk(md), 0);
996 else
997 set_disk_ro(dm_disk(md), 1);
998 }
999
1000 if (dm_suspended_md(md)) {
1001 r = dm_resume(md);
1002 if (!r && !dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr))
1003 param->flags |= DM_UEVENT_GENERATED_FLAG;
1004 }
1005
1006 if (old_map)
1007 dm_table_destroy(old_map);
1008
1009 if (!r)
1010 __dev_status(md, param);
1011
1012 dm_put(md);
1013 return r;
1014 }
1015
1016 /*
1017 * Set or unset the suspension state of a device.
1018 * If the device already is in the requested state we just return its status.
1019 */
1020 static int dev_suspend(struct dm_ioctl *param, size_t param_size)
1021 {
1022 if (param->flags & DM_SUSPEND_FLAG)
1023 return do_suspend(param);
1024
1025 return do_resume(param);
1026 }
1027
1028 /*
1029 * Copies device info back to user space, used by
1030 * the create and info ioctls.
1031 */
1032 static int dev_status(struct dm_ioctl *param, size_t param_size)
1033 {
1034 struct mapped_device *md;
1035
1036 md = find_device(param);
1037 if (!md)
1038 return -ENXIO;
1039
1040 __dev_status(md, param);
1041 dm_put(md);
1042
1043 return 0;
1044 }
1045
1046 /*
1047 * Build up the status struct for each target
1048 */
1049 static void retrieve_status(struct dm_table *table,
1050 struct dm_ioctl *param, size_t param_size)
1051 {
1052 unsigned int i, num_targets;
1053 struct dm_target_spec *spec;
1054 char *outbuf, *outptr;
1055 status_type_t type;
1056 size_t remaining, len, used = 0;
1057
1058 outptr = outbuf = get_result_buffer(param, param_size, &len);
1059
1060 if (param->flags & DM_STATUS_TABLE_FLAG)
1061 type = STATUSTYPE_TABLE;
1062 else
1063 type = STATUSTYPE_INFO;
1064
1065 /* Get all the target info */
1066 num_targets = dm_table_get_num_targets(table);
1067 for (i = 0; i < num_targets; i++) {
1068 struct dm_target *ti = dm_table_get_target(table, i);
1069
1070 remaining = len - (outptr - outbuf);
1071 if (remaining <= sizeof(struct dm_target_spec)) {
1072 param->flags |= DM_BUFFER_FULL_FLAG;
1073 break;
1074 }
1075
1076 spec = (struct dm_target_spec *) outptr;
1077
1078 spec->status = 0;
1079 spec->sector_start = ti->begin;
1080 spec->length = ti->len;
1081 strncpy(spec->target_type, ti->type->name,
1082 sizeof(spec->target_type));
1083
1084 outptr += sizeof(struct dm_target_spec);
1085 remaining = len - (outptr - outbuf);
1086 if (remaining <= 0) {
1087 param->flags |= DM_BUFFER_FULL_FLAG;
1088 break;
1089 }
1090
1091 /* Get the status/table string from the target driver */
1092 if (ti->type->status) {
1093 if (ti->type->status(ti, type, outptr, remaining)) {
1094 param->flags |= DM_BUFFER_FULL_FLAG;
1095 break;
1096 }
1097 } else
1098 outptr[0] = '\0';
1099
1100 outptr += strlen(outptr) + 1;
1101 used = param->data_start + (outptr - outbuf);
1102
1103 outptr = align_ptr(outptr);
1104 spec->next = outptr - outbuf;
1105 }
1106
1107 if (used)
1108 param->data_size = used;
1109
1110 param->target_count = num_targets;
1111 }
1112
1113 /*
1114 * Wait for a device to report an event
1115 */
1116 static int dev_wait(struct dm_ioctl *param, size_t param_size)
1117 {
1118 int r = 0;
1119 struct mapped_device *md;
1120 struct dm_table *table;
1121
1122 md = find_device(param);
1123 if (!md)
1124 return -ENXIO;
1125
1126 /*
1127 * Wait for a notification event
1128 */
1129 if (dm_wait_event(md, param->event_nr)) {
1130 r = -ERESTARTSYS;
1131 goto out;
1132 }
1133
1134 /*
1135 * The userland program is going to want to know what
1136 * changed to trigger the event, so we may as well tell
1137 * him and save an ioctl.
1138 */
1139 __dev_status(md, param);
1140
1141 table = dm_get_live_or_inactive_table(md, param);
1142 if (table) {
1143 retrieve_status(table, param, param_size);
1144 dm_table_put(table);
1145 }
1146
1147 out:
1148 dm_put(md);
1149
1150 return r;
1151 }
1152
1153 static inline fmode_t get_mode(struct dm_ioctl *param)
1154 {
1155 fmode_t mode = FMODE_READ | FMODE_WRITE;
1156
1157 if (param->flags & DM_READONLY_FLAG)
1158 mode = FMODE_READ;
1159
1160 return mode;
1161 }
1162
1163 static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
1164 struct dm_target_spec **spec, char **target_params)
1165 {
1166 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1167 *target_params = (char *) (*spec + 1);
1168
1169 if (*spec < (last + 1))
1170 return -EINVAL;
1171
1172 return invalid_str(*target_params, end);
1173 }
1174
1175 static int populate_table(struct dm_table *table,
1176 struct dm_ioctl *param, size_t param_size)
1177 {
1178 int r;
1179 unsigned int i = 0;
1180 struct dm_target_spec *spec = (struct dm_target_spec *) param;
1181 uint32_t next = param->data_start;
1182 void *end = (void *) param + param_size;
1183 char *target_params;
1184
1185 if (!param->target_count) {
1186 DMWARN("populate_table: no targets specified");
1187 return -EINVAL;
1188 }
1189
1190 for (i = 0; i < param->target_count; i++) {
1191
1192 r = next_target(spec, next, end, &spec, &target_params);
1193 if (r) {
1194 DMWARN("unable to find target");
1195 return r;
1196 }
1197
1198 r = dm_table_add_target(table, spec->target_type,
1199 (sector_t) spec->sector_start,
1200 (sector_t) spec->length,
1201 target_params);
1202 if (r) {
1203 DMWARN("error adding target to table");
1204 return r;
1205 }
1206
1207 next = spec->next;
1208 }
1209
1210 return dm_table_complete(table);
1211 }
1212
1213 static int table_load(struct dm_ioctl *param, size_t param_size)
1214 {
1215 int r;
1216 struct hash_cell *hc;
1217 struct dm_table *t;
1218 struct mapped_device *md;
1219 struct target_type *immutable_target_type;
1220
1221 md = find_device(param);
1222 if (!md)
1223 return -ENXIO;
1224
1225 r = dm_table_create(&t, get_mode(param), param->target_count, md);
1226 if (r)
1227 goto out;
1228
1229 r = populate_table(t, param, param_size);
1230 if (r) {
1231 dm_table_destroy(t);
1232 goto out;
1233 }
1234
1235 immutable_target_type = dm_get_immutable_target_type(md);
1236 if (immutable_target_type &&
1237 (immutable_target_type != dm_table_get_immutable_target_type(t))) {
1238 DMWARN("can't replace immutable target type %s",
1239 immutable_target_type->name);
1240 dm_table_destroy(t);
1241 r = -EINVAL;
1242 goto out;
1243 }
1244
1245 /* Protect md->type and md->queue against concurrent table loads. */
1246 dm_lock_md_type(md);
1247 if (dm_get_md_type(md) == DM_TYPE_NONE)
1248 /* Initial table load: acquire type of table. */
1249 dm_set_md_type(md, dm_table_get_type(t));
1250 else if (dm_get_md_type(md) != dm_table_get_type(t)) {
1251 DMWARN("can't change device type after initial table load.");
1252 dm_table_destroy(t);
1253 dm_unlock_md_type(md);
1254 r = -EINVAL;
1255 goto out;
1256 }
1257
1258 /* setup md->queue to reflect md's type (may block) */
1259 r = dm_setup_md_queue(md);
1260 if (r) {
1261 DMWARN("unable to set up device queue for new table.");
1262 dm_table_destroy(t);
1263 dm_unlock_md_type(md);
1264 goto out;
1265 }
1266 dm_unlock_md_type(md);
1267
1268 /* stage inactive table */
1269 down_write(&_hash_lock);
1270 hc = dm_get_mdptr(md);
1271 if (!hc || hc->md != md) {
1272 DMWARN("device has been removed from the dev hash table.");
1273 dm_table_destroy(t);
1274 up_write(&_hash_lock);
1275 r = -ENXIO;
1276 goto out;
1277 }
1278
1279 if (hc->new_map)
1280 dm_table_destroy(hc->new_map);
1281 hc->new_map = t;
1282 up_write(&_hash_lock);
1283
1284 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1285 __dev_status(md, param);
1286
1287 out:
1288 dm_put(md);
1289
1290 return r;
1291 }
1292
1293 static int table_clear(struct dm_ioctl *param, size_t param_size)
1294 {
1295 struct hash_cell *hc;
1296 struct mapped_device *md;
1297
1298 down_write(&_hash_lock);
1299
1300 hc = __find_device_hash_cell(param);
1301 if (!hc) {
1302 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1303 up_write(&_hash_lock);
1304 return -ENXIO;
1305 }
1306
1307 if (hc->new_map) {
1308 dm_table_destroy(hc->new_map);
1309 hc->new_map = NULL;
1310 }
1311
1312 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1313
1314 __dev_status(hc->md, param);
1315 md = hc->md;
1316 up_write(&_hash_lock);
1317 dm_put(md);
1318
1319 return 0;
1320 }
1321
1322 /*
1323 * Retrieves a list of devices used by a particular dm device.
1324 */
1325 static void retrieve_deps(struct dm_table *table,
1326 struct dm_ioctl *param, size_t param_size)
1327 {
1328 unsigned int count = 0;
1329 struct list_head *tmp;
1330 size_t len, needed;
1331 struct dm_dev_internal *dd;
1332 struct dm_target_deps *deps;
1333
1334 deps = get_result_buffer(param, param_size, &len);
1335
1336 /*
1337 * Count the devices.
1338 */
1339 list_for_each (tmp, dm_table_get_devices(table))
1340 count++;
1341
1342 /*
1343 * Check we have enough space.
1344 */
1345 needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
1346 if (len < needed) {
1347 param->flags |= DM_BUFFER_FULL_FLAG;
1348 return;
1349 }
1350
1351 /*
1352 * Fill in the devices.
1353 */
1354 deps->count = count;
1355 count = 0;
1356 list_for_each_entry (dd, dm_table_get_devices(table), list)
1357 deps->dev[count++] = huge_encode_dev(dd->dm_dev.bdev->bd_dev);
1358
1359 param->data_size = param->data_start + needed;
1360 }
1361
1362 static int table_deps(struct dm_ioctl *param, size_t param_size)
1363 {
1364 struct mapped_device *md;
1365 struct dm_table *table;
1366
1367 md = find_device(param);
1368 if (!md)
1369 return -ENXIO;
1370
1371 __dev_status(md, param);
1372
1373 table = dm_get_live_or_inactive_table(md, param);
1374 if (table) {
1375 retrieve_deps(table, param, param_size);
1376 dm_table_put(table);
1377 }
1378
1379 dm_put(md);
1380
1381 return 0;
1382 }
1383
1384 /*
1385 * Return the status of a device as a text string for each
1386 * target.
1387 */
1388 static int table_status(struct dm_ioctl *param, size_t param_size)
1389 {
1390 struct mapped_device *md;
1391 struct dm_table *table;
1392
1393 md = find_device(param);
1394 if (!md)
1395 return -ENXIO;
1396
1397 __dev_status(md, param);
1398
1399 table = dm_get_live_or_inactive_table(md, param);
1400 if (table) {
1401 retrieve_status(table, param, param_size);
1402 dm_table_put(table);
1403 }
1404
1405 dm_put(md);
1406
1407 return 0;
1408 }
1409
1410 /*
1411 * Pass a message to the target that's at the supplied device offset.
1412 */
1413 static int target_message(struct dm_ioctl *param, size_t param_size)
1414 {
1415 int r, argc;
1416 char **argv;
1417 struct mapped_device *md;
1418 struct dm_table *table;
1419 struct dm_target *ti;
1420 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1421
1422 md = find_device(param);
1423 if (!md)
1424 return -ENXIO;
1425
1426 if (tmsg < (struct dm_target_msg *) param->data ||
1427 invalid_str(tmsg->message, (void *) param + param_size)) {
1428 DMWARN("Invalid target message parameters.");
1429 r = -EINVAL;
1430 goto out;
1431 }
1432
1433 r = dm_split_args(&argc, &argv, tmsg->message);
1434 if (r) {
1435 DMWARN("Failed to split target message parameters");
1436 goto out;
1437 }
1438
1439 if (!argc) {
1440 DMWARN("Empty message received.");
1441 goto out_argv;
1442 }
1443
1444 table = dm_get_live_table(md);
1445 if (!table)
1446 goto out_argv;
1447
1448 if (dm_deleting_md(md)) {
1449 r = -ENXIO;
1450 goto out_table;
1451 }
1452
1453 ti = dm_table_find_target(table, tmsg->sector);
1454 if (!dm_target_is_valid(ti)) {
1455 DMWARN("Target message sector outside device.");
1456 r = -EINVAL;
1457 } else if (ti->type->message)
1458 r = ti->type->message(ti, argc, argv);
1459 else {
1460 DMWARN("Target type does not support messages");
1461 r = -EINVAL;
1462 }
1463
1464 out_table:
1465 dm_table_put(table);
1466 out_argv:
1467 kfree(argv);
1468 out:
1469 param->data_size = 0;
1470 dm_put(md);
1471 return r;
1472 }
1473
1474 /*-----------------------------------------------------------------
1475 * Implementation of open/close/ioctl on the special char
1476 * device.
1477 *---------------------------------------------------------------*/
1478 static ioctl_fn lookup_ioctl(unsigned int cmd)
1479 {
1480 static struct {
1481 int cmd;
1482 ioctl_fn fn;
1483 } _ioctls[] = {
1484 {DM_VERSION_CMD, NULL}, /* version is dealt with elsewhere */
1485 {DM_REMOVE_ALL_CMD, remove_all},
1486 {DM_LIST_DEVICES_CMD, list_devices},
1487
1488 {DM_DEV_CREATE_CMD, dev_create},
1489 {DM_DEV_REMOVE_CMD, dev_remove},
1490 {DM_DEV_RENAME_CMD, dev_rename},
1491 {DM_DEV_SUSPEND_CMD, dev_suspend},
1492 {DM_DEV_STATUS_CMD, dev_status},
1493 {DM_DEV_WAIT_CMD, dev_wait},
1494
1495 {DM_TABLE_LOAD_CMD, table_load},
1496 {DM_TABLE_CLEAR_CMD, table_clear},
1497 {DM_TABLE_DEPS_CMD, table_deps},
1498 {DM_TABLE_STATUS_CMD, table_status},
1499
1500 {DM_LIST_VERSIONS_CMD, list_versions},
1501
1502 {DM_TARGET_MSG_CMD, target_message},
1503 {DM_DEV_SET_GEOMETRY_CMD, dev_set_geometry}
1504 };
1505
1506 return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn;
1507 }
1508
1509 /*
1510 * As well as checking the version compatibility this always
1511 * copies the kernel interface version out.
1512 */
1513 static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1514 {
1515 uint32_t version[3];
1516 int r = 0;
1517
1518 if (copy_from_user(version, user->version, sizeof(version)))
1519 return -EFAULT;
1520
1521 if ((DM_VERSION_MAJOR != version[0]) ||
1522 (DM_VERSION_MINOR < version[1])) {
1523 DMWARN("ioctl interface mismatch: "
1524 "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1525 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1526 DM_VERSION_PATCHLEVEL,
1527 version[0], version[1], version[2], cmd);
1528 r = -EINVAL;
1529 }
1530
1531 /*
1532 * Fill in the kernel version.
1533 */
1534 version[0] = DM_VERSION_MAJOR;
1535 version[1] = DM_VERSION_MINOR;
1536 version[2] = DM_VERSION_PATCHLEVEL;
1537 if (copy_to_user(user->version, version, sizeof(version)))
1538 return -EFAULT;
1539
1540 return r;
1541 }
1542
1543 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
1544 {
1545 struct dm_ioctl tmp, *dmi;
1546 int secure_data;
1547
1548 if (copy_from_user(&tmp, user, sizeof(tmp) - sizeof(tmp.data)))
1549 return -EFAULT;
1550
1551 if (tmp.data_size < (sizeof(tmp) - sizeof(tmp.data)))
1552 return -EINVAL;
1553
1554 secure_data = tmp.flags & DM_SECURE_DATA_FLAG;
1555
1556 dmi = vmalloc(tmp.data_size);
1557 if (!dmi) {
1558 if (secure_data && clear_user(user, tmp.data_size))
1559 return -EFAULT;
1560 return -ENOMEM;
1561 }
1562
1563 if (copy_from_user(dmi, user, tmp.data_size))
1564 goto bad;
1565
1566 /* Wipe the user buffer so we do not return it to userspace */
1567 if (secure_data && clear_user(user, tmp.data_size))
1568 goto bad;
1569
1570 *param = dmi;
1571 return 0;
1572
1573 bad:
1574 if (secure_data)
1575 memset(dmi, 0, tmp.data_size);
1576 vfree(dmi);
1577 return -EFAULT;
1578 }
1579
1580 static int validate_params(uint cmd, struct dm_ioctl *param)
1581 {
1582 /* Always clear this flag */
1583 param->flags &= ~DM_BUFFER_FULL_FLAG;
1584 param->flags &= ~DM_UEVENT_GENERATED_FLAG;
1585 param->flags &= ~DM_SECURE_DATA_FLAG;
1586
1587 /* Ignores parameters */
1588 if (cmd == DM_REMOVE_ALL_CMD ||
1589 cmd == DM_LIST_DEVICES_CMD ||
1590 cmd == DM_LIST_VERSIONS_CMD)
1591 return 0;
1592
1593 if ((cmd == DM_DEV_CREATE_CMD)) {
1594 if (!*param->name) {
1595 DMWARN("name not supplied when creating device");
1596 return -EINVAL;
1597 }
1598 } else if ((*param->uuid && *param->name)) {
1599 DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
1600 return -EINVAL;
1601 }
1602
1603 /* Ensure strings are terminated */
1604 param->name[DM_NAME_LEN - 1] = '\0';
1605 param->uuid[DM_UUID_LEN - 1] = '\0';
1606
1607 return 0;
1608 }
1609
1610 static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
1611 {
1612 int r = 0;
1613 int wipe_buffer;
1614 unsigned int cmd;
1615 struct dm_ioctl *uninitialized_var(param);
1616 ioctl_fn fn = NULL;
1617 size_t input_param_size;
1618
1619 /* only root can play with this */
1620 if (!capable(CAP_SYS_ADMIN))
1621 return -EACCES;
1622
1623 if (_IOC_TYPE(command) != DM_IOCTL)
1624 return -ENOTTY;
1625
1626 cmd = _IOC_NR(command);
1627
1628 /*
1629 * Check the interface version passed in. This also
1630 * writes out the kernel's interface version.
1631 */
1632 r = check_version(cmd, user);
1633 if (r)
1634 return r;
1635
1636 /*
1637 * Nothing more to do for the version command.
1638 */
1639 if (cmd == DM_VERSION_CMD)
1640 return 0;
1641
1642 fn = lookup_ioctl(cmd);
1643 if (!fn) {
1644 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1645 return -ENOTTY;
1646 }
1647
1648 /*
1649 * Trying to avoid low memory issues when a device is
1650 * suspended.
1651 */
1652 current->flags |= PF_MEMALLOC;
1653
1654 /*
1655 * Copy the parameters into kernel space.
1656 */
1657 r = copy_params(user, &param);
1658
1659 current->flags &= ~PF_MEMALLOC;
1660
1661 if (r)
1662 return r;
1663
1664 input_param_size = param->data_size;
1665 wipe_buffer = param->flags & DM_SECURE_DATA_FLAG;
1666
1667 r = validate_params(cmd, param);
1668 if (r)
1669 goto out;
1670
1671 param->data_size = sizeof(*param);
1672 r = fn(param, input_param_size);
1673
1674 /*
1675 * Copy the results back to userland.
1676 */
1677 if (!r && copy_to_user(user, param, param->data_size))
1678 r = -EFAULT;
1679
1680 out:
1681 if (wipe_buffer)
1682 memset(param, 0, input_param_size);
1683
1684 vfree(param);
1685 return r;
1686 }
1687
1688 static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
1689 {
1690 return (long)ctl_ioctl(command, (struct dm_ioctl __user *)u);
1691 }
1692
1693 #ifdef CONFIG_COMPAT
1694 static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
1695 {
1696 return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
1697 }
1698 #else
1699 #define dm_compat_ctl_ioctl NULL
1700 #endif
1701
1702 static const struct file_operations _ctl_fops = {
1703 .open = nonseekable_open,
1704 .unlocked_ioctl = dm_ctl_ioctl,
1705 .compat_ioctl = dm_compat_ctl_ioctl,
1706 .owner = THIS_MODULE,
1707 .llseek = noop_llseek,
1708 };
1709
1710 static struct miscdevice _dm_misc = {
1711 .minor = MAPPER_CTRL_MINOR,
1712 .name = DM_NAME,
1713 .nodename = DM_DIR "/" DM_CONTROL_NODE,
1714 .fops = &_ctl_fops
1715 };
1716
1717 MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
1718 MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
1719
1720 /*
1721 * Create misc character device and link to DM_DIR/control.
1722 */
1723 int __init dm_interface_init(void)
1724 {
1725 int r;
1726
1727 r = dm_hash_init();
1728 if (r)
1729 return r;
1730
1731 r = misc_register(&_dm_misc);
1732 if (r) {
1733 DMERR("misc_register failed for control device");
1734 dm_hash_exit();
1735 return r;
1736 }
1737
1738 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
1739 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
1740 DM_DRIVER_EMAIL);
1741 return 0;
1742 }
1743
1744 void dm_interface_exit(void)
1745 {
1746 if (misc_deregister(&_dm_misc) < 0)
1747 DMERR("misc_deregister failed for control device");
1748
1749 dm_hash_exit();
1750 }
1751
1752 /**
1753 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
1754 * @md: Pointer to mapped_device
1755 * @name: Buffer (size DM_NAME_LEN) for name
1756 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
1757 */
1758 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
1759 {
1760 int r = 0;
1761 struct hash_cell *hc;
1762
1763 if (!md)
1764 return -ENXIO;
1765
1766 mutex_lock(&dm_hash_cells_mutex);
1767 hc = dm_get_mdptr(md);
1768 if (!hc || hc->md != md) {
1769 r = -ENXIO;
1770 goto out;
1771 }
1772
1773 if (name)
1774 strcpy(name, hc->name);
1775 if (uuid)
1776 strcpy(uuid, hc->uuid ? : "");
1777
1778 out:
1779 mutex_unlock(&dm_hash_cells_mutex);
1780
1781 return r;
1782 }
Linux with added FPC-III support