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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 *---------------------------------------------------------------*/
29struct 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
39struct 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)
49static struct list_head _name_buckets[NUM_BUCKETS];
50static struct list_head _uuid_buckets[NUM_BUCKETS];
51
52static void dm_hash_remove_all(int keep_open_devices);
53
54/*
55 * Guards access to both hash tables.
56 */
57static DECLARE_RWSEM(_hash_lock);
58
59/*
60 * Protects use of mdptr to obtain hash cell name and uuid from mapped device.
61 */
62static DEFINE_MUTEX(dm_hash_cells_mutex);
63
64static 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
72static int dm_hash_init(void)
73{
74 init_buckets(_name_buckets);
75 init_buckets(_uuid_buckets);
76 return 0;
77}
78
79static 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 *---------------------------------------------------------------*/
89static 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 *---------------------------------------------------------------*/
103static 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
117static 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
131static 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 *---------------------------------------------------------------*/
152static 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
186static 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 */
199static 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
245static 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
268static 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
274retry:
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 */
319static 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 */
332static 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
351static 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 */
444typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size);
445
446static 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
457static 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 */
466static 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
479static 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
536static 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
545static 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
570static 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
608static 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 */
623static 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
639out:
640 up_read(&_hash_lock);
641
642 return table;
643}
644
645static 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 */
656static 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
702static 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 */
737static 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
780static 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
794static 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 */
837static 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
846static 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
876static 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
918out:
919 dm_put(md);
920 return r;
921}
922
923static 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
946out:
947 dm_put(md);
948
949 return r;
950}
951
952static 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 */
1020static 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 */
1032static 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 */
1049static 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 */
1116static 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
1147out:
1148 dm_put(md);
1149
1150 return r;
1151}
1152
1153static 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
1163static 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
1175static 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
1213static 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
1287out:
1288 dm_put(md);
1289
1290 return r;
1291}
1292
1293static 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 */
1325static 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
1362static 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 */
1388static 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 */
1413static 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 *---------------------------------------------------------------*/
1478static 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 */
1513static 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
1543static 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
1573bad:
1574 if (secure_data)
1575 memset(dmi, 0, tmp.data_size);
1576 vfree(dmi);
1577 return -EFAULT;
1578}
1579
1580static 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
1610static 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, ¶m);
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
1680out:
1681 if (wipe_buffer)
1682 memset(param, 0, input_param_size);
1683
1684 vfree(param);
1685 return r;
1686}
1687
1688static 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
1694static 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
1702static 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
1710static 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
1717MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
1718MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
1719
1720/*
1721 * Create misc character device and link to DM_DIR/control.
1722 */
1723int __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
1744void 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 */
1758int 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
1778out:
1779 mutex_unlock(&dm_hash_cells_mutex);
1780
1781 return r;
1782}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
4 * Copyright (C) 2004 - 2006 Red Hat, Inc. All rights reserved.
5 *
6 * This file is released under the GPL.
7 */
8
9#include "dm-core.h"
10#include "dm-ima.h"
11#include <linux/module.h>
12#include <linux/vmalloc.h>
13#include <linux/miscdevice.h>
14#include <linux/sched/mm.h>
15#include <linux/init.h>
16#include <linux/wait.h>
17#include <linux/slab.h>
18#include <linux/rbtree.h>
19#include <linux/dm-ioctl.h>
20#include <linux/hdreg.h>
21#include <linux/compat.h>
22#include <linux/nospec.h>
23
24#include <linux/uaccess.h>
25#include <linux/ima.h>
26
27#define DM_MSG_PREFIX "ioctl"
28#define DM_DRIVER_EMAIL "dm-devel@lists.linux.dev"
29
30struct dm_file {
31 /*
32 * poll will wait until the global event number is greater than
33 * this value.
34 */
35 volatile unsigned int global_event_nr;
36};
37
38/*
39 *---------------------------------------------------------------
40 * The ioctl interface needs to be able to look up devices by
41 * name or uuid.
42 *---------------------------------------------------------------
43 */
44struct hash_cell {
45 struct rb_node name_node;
46 struct rb_node uuid_node;
47 bool name_set;
48 bool uuid_set;
49
50 char *name;
51 char *uuid;
52 struct mapped_device *md;
53 struct dm_table *new_map;
54};
55
56struct vers_iter {
57 size_t param_size;
58 struct dm_target_versions *vers, *old_vers;
59 char *end;
60 uint32_t flags;
61};
62
63
64static struct rb_root name_rb_tree = RB_ROOT;
65static struct rb_root uuid_rb_tree = RB_ROOT;
66
67static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred);
68
69/*
70 * Guards access to both hash tables.
71 */
72static DECLARE_RWSEM(_hash_lock);
73
74/*
75 * Protects use of mdptr to obtain hash cell name and uuid from mapped device.
76 */
77static DEFINE_MUTEX(dm_hash_cells_mutex);
78
79static void dm_hash_exit(void)
80{
81 dm_hash_remove_all(false, false, false);
82}
83
84/*
85 *---------------------------------------------------------------
86 * Code for looking up a device by name
87 *---------------------------------------------------------------
88 */
89static struct hash_cell *__get_name_cell(const char *str)
90{
91 struct rb_node *n = name_rb_tree.rb_node;
92
93 while (n) {
94 struct hash_cell *hc = container_of(n, struct hash_cell, name_node);
95 int c;
96
97 c = strcmp(hc->name, str);
98 if (!c) {
99 dm_get(hc->md);
100 return hc;
101 }
102 n = c >= 0 ? n->rb_left : n->rb_right;
103 }
104
105 return NULL;
106}
107
108static struct hash_cell *__get_uuid_cell(const char *str)
109{
110 struct rb_node *n = uuid_rb_tree.rb_node;
111
112 while (n) {
113 struct hash_cell *hc = container_of(n, struct hash_cell, uuid_node);
114 int c;
115
116 c = strcmp(hc->uuid, str);
117 if (!c) {
118 dm_get(hc->md);
119 return hc;
120 }
121 n = c >= 0 ? n->rb_left : n->rb_right;
122 }
123
124 return NULL;
125}
126
127static void __unlink_name(struct hash_cell *hc)
128{
129 if (hc->name_set) {
130 hc->name_set = false;
131 rb_erase(&hc->name_node, &name_rb_tree);
132 }
133}
134
135static void __unlink_uuid(struct hash_cell *hc)
136{
137 if (hc->uuid_set) {
138 hc->uuid_set = false;
139 rb_erase(&hc->uuid_node, &uuid_rb_tree);
140 }
141}
142
143static void __link_name(struct hash_cell *new_hc)
144{
145 struct rb_node **n, *parent;
146
147 __unlink_name(new_hc);
148
149 new_hc->name_set = true;
150
151 n = &name_rb_tree.rb_node;
152 parent = NULL;
153
154 while (*n) {
155 struct hash_cell *hc = container_of(*n, struct hash_cell, name_node);
156 int c;
157
158 c = strcmp(hc->name, new_hc->name);
159 BUG_ON(!c);
160 parent = *n;
161 n = c >= 0 ? &hc->name_node.rb_left : &hc->name_node.rb_right;
162 }
163
164 rb_link_node(&new_hc->name_node, parent, n);
165 rb_insert_color(&new_hc->name_node, &name_rb_tree);
166}
167
168static void __link_uuid(struct hash_cell *new_hc)
169{
170 struct rb_node **n, *parent;
171
172 __unlink_uuid(new_hc);
173
174 new_hc->uuid_set = true;
175
176 n = &uuid_rb_tree.rb_node;
177 parent = NULL;
178
179 while (*n) {
180 struct hash_cell *hc = container_of(*n, struct hash_cell, uuid_node);
181 int c;
182
183 c = strcmp(hc->uuid, new_hc->uuid);
184 BUG_ON(!c);
185 parent = *n;
186 n = c > 0 ? &hc->uuid_node.rb_left : &hc->uuid_node.rb_right;
187 }
188
189 rb_link_node(&new_hc->uuid_node, parent, n);
190 rb_insert_color(&new_hc->uuid_node, &uuid_rb_tree);
191}
192
193static struct hash_cell *__get_dev_cell(uint64_t dev)
194{
195 struct mapped_device *md;
196 struct hash_cell *hc;
197
198 md = dm_get_md(huge_decode_dev(dev));
199 if (!md)
200 return NULL;
201
202 hc = dm_get_mdptr(md);
203 if (!hc) {
204 dm_put(md);
205 return NULL;
206 }
207
208 return hc;
209}
210
211/*
212 *---------------------------------------------------------------
213 * Inserting, removing and renaming a device.
214 *---------------------------------------------------------------
215 */
216static struct hash_cell *alloc_cell(const char *name, const char *uuid,
217 struct mapped_device *md)
218{
219 struct hash_cell *hc;
220
221 hc = kmalloc(sizeof(*hc), GFP_KERNEL);
222 if (!hc)
223 return NULL;
224
225 hc->name = kstrdup(name, GFP_KERNEL);
226 if (!hc->name) {
227 kfree(hc);
228 return NULL;
229 }
230
231 if (!uuid)
232 hc->uuid = NULL;
233
234 else {
235 hc->uuid = kstrdup(uuid, GFP_KERNEL);
236 if (!hc->uuid) {
237 kfree(hc->name);
238 kfree(hc);
239 return NULL;
240 }
241 }
242
243 hc->name_set = hc->uuid_set = false;
244 hc->md = md;
245 hc->new_map = NULL;
246 return hc;
247}
248
249static void free_cell(struct hash_cell *hc)
250{
251 if (hc) {
252 kfree(hc->name);
253 kfree(hc->uuid);
254 kfree(hc);
255 }
256}
257
258/*
259 * The kdev_t and uuid of a device can never change once it is
260 * initially inserted.
261 */
262static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
263{
264 struct hash_cell *cell, *hc;
265
266 /*
267 * Allocate the new cells.
268 */
269 cell = alloc_cell(name, uuid, md);
270 if (!cell)
271 return -ENOMEM;
272
273 /*
274 * Insert the cell into both hash tables.
275 */
276 down_write(&_hash_lock);
277 hc = __get_name_cell(name);
278 if (hc) {
279 dm_put(hc->md);
280 goto bad;
281 }
282
283 __link_name(cell);
284
285 if (uuid) {
286 hc = __get_uuid_cell(uuid);
287 if (hc) {
288 __unlink_name(cell);
289 dm_put(hc->md);
290 goto bad;
291 }
292 __link_uuid(cell);
293 }
294 dm_get(md);
295 mutex_lock(&dm_hash_cells_mutex);
296 dm_set_mdptr(md, cell);
297 mutex_unlock(&dm_hash_cells_mutex);
298 up_write(&_hash_lock);
299
300 return 0;
301
302 bad:
303 up_write(&_hash_lock);
304 free_cell(cell);
305 return -EBUSY;
306}
307
308static struct dm_table *__hash_remove(struct hash_cell *hc)
309{
310 struct dm_table *table;
311 int srcu_idx;
312
313 lockdep_assert_held(&_hash_lock);
314
315 /* remove from the dev trees */
316 __unlink_name(hc);
317 __unlink_uuid(hc);
318 mutex_lock(&dm_hash_cells_mutex);
319 dm_set_mdptr(hc->md, NULL);
320 mutex_unlock(&dm_hash_cells_mutex);
321
322 table = dm_get_live_table(hc->md, &srcu_idx);
323 if (table)
324 dm_table_event(table);
325 dm_put_live_table(hc->md, srcu_idx);
326
327 table = NULL;
328 if (hc->new_map)
329 table = hc->new_map;
330 dm_put(hc->md);
331 free_cell(hc);
332
333 return table;
334}
335
336static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred)
337{
338 int dev_skipped;
339 struct rb_node *n;
340 struct hash_cell *hc;
341 struct mapped_device *md;
342 struct dm_table *t;
343
344retry:
345 dev_skipped = 0;
346
347 down_write(&_hash_lock);
348
349 for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {
350 hc = container_of(n, struct hash_cell, name_node);
351 md = hc->md;
352 dm_get(md);
353
354 if (keep_open_devices &&
355 dm_lock_for_deletion(md, mark_deferred, only_deferred)) {
356 dm_put(md);
357 dev_skipped++;
358 continue;
359 }
360
361 t = __hash_remove(hc);
362
363 up_write(&_hash_lock);
364
365 if (t) {
366 dm_sync_table(md);
367 dm_table_destroy(t);
368 }
369 dm_ima_measure_on_device_remove(md, true);
370 dm_put(md);
371 if (likely(keep_open_devices))
372 dm_destroy(md);
373 else
374 dm_destroy_immediate(md);
375
376 /*
377 * Some mapped devices may be using other mapped
378 * devices, so repeat until we make no further
379 * progress. If a new mapped device is created
380 * here it will also get removed.
381 */
382 goto retry;
383 }
384
385 up_write(&_hash_lock);
386
387 if (dev_skipped)
388 DMWARN("remove_all left %d open device(s)", dev_skipped);
389}
390
391/*
392 * Set the uuid of a hash_cell that isn't already set.
393 */
394static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
395{
396 mutex_lock(&dm_hash_cells_mutex);
397 hc->uuid = new_uuid;
398 mutex_unlock(&dm_hash_cells_mutex);
399
400 __link_uuid(hc);
401}
402
403/*
404 * Changes the name of a hash_cell and returns the old name for
405 * the caller to free.
406 */
407static char *__change_cell_name(struct hash_cell *hc, char *new_name)
408{
409 char *old_name;
410
411 /*
412 * Rename and move the name cell.
413 */
414 __unlink_name(hc);
415 old_name = hc->name;
416
417 mutex_lock(&dm_hash_cells_mutex);
418 hc->name = new_name;
419 mutex_unlock(&dm_hash_cells_mutex);
420
421 __link_name(hc);
422
423 return old_name;
424}
425
426static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
427 const char *new)
428{
429 char *new_data, *old_name = NULL;
430 struct hash_cell *hc;
431 struct dm_table *table;
432 struct mapped_device *md;
433 unsigned int change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
434 int srcu_idx;
435
436 /*
437 * duplicate new.
438 */
439 new_data = kstrdup(new, GFP_KERNEL);
440 if (!new_data)
441 return ERR_PTR(-ENOMEM);
442
443 down_write(&_hash_lock);
444
445 /*
446 * Is new free ?
447 */
448 if (change_uuid)
449 hc = __get_uuid_cell(new);
450 else
451 hc = __get_name_cell(new);
452
453 if (hc) {
454 DMERR("Unable to change %s on mapped device %s to one that already exists: %s",
455 change_uuid ? "uuid" : "name",
456 param->name, new);
457 dm_put(hc->md);
458 up_write(&_hash_lock);
459 kfree(new_data);
460 return ERR_PTR(-EBUSY);
461 }
462
463 /*
464 * Is there such a device as 'old' ?
465 */
466 hc = __get_name_cell(param->name);
467 if (!hc) {
468 DMERR("Unable to rename non-existent device, %s to %s%s",
469 param->name, change_uuid ? "uuid " : "", new);
470 up_write(&_hash_lock);
471 kfree(new_data);
472 return ERR_PTR(-ENXIO);
473 }
474
475 /*
476 * Does this device already have a uuid?
477 */
478 if (change_uuid && hc->uuid) {
479 DMERR("Unable to change uuid of mapped device %s to %s "
480 "because uuid is already set to %s",
481 param->name, new, hc->uuid);
482 dm_put(hc->md);
483 up_write(&_hash_lock);
484 kfree(new_data);
485 return ERR_PTR(-EINVAL);
486 }
487
488 if (change_uuid)
489 __set_cell_uuid(hc, new_data);
490 else
491 old_name = __change_cell_name(hc, new_data);
492
493 /*
494 * Wake up any dm event waiters.
495 */
496 table = dm_get_live_table(hc->md, &srcu_idx);
497 if (table)
498 dm_table_event(table);
499 dm_put_live_table(hc->md, srcu_idx);
500
501 if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr, false))
502 param->flags |= DM_UEVENT_GENERATED_FLAG;
503
504 md = hc->md;
505
506 dm_ima_measure_on_device_rename(md);
507
508 up_write(&_hash_lock);
509 kfree(old_name);
510
511 return md;
512}
513
514void dm_deferred_remove(void)
515{
516 dm_hash_remove_all(true, false, true);
517}
518
519/*
520 *---------------------------------------------------------------
521 * Implementation of the ioctl commands
522 *---------------------------------------------------------------
523 */
524/*
525 * All the ioctl commands get dispatched to functions with this
526 * prototype.
527 */
528typedef int (*ioctl_fn)(struct file *filp, struct dm_ioctl *param, size_t param_size);
529
530static int remove_all(struct file *filp, struct dm_ioctl *param, size_t param_size)
531{
532 dm_hash_remove_all(true, !!(param->flags & DM_DEFERRED_REMOVE), false);
533 param->data_size = 0;
534 return 0;
535}
536
537/*
538 * Round up the ptr to an 8-byte boundary.
539 */
540#define ALIGN_MASK 7
541static inline size_t align_val(size_t val)
542{
543 return (val + ALIGN_MASK) & ~ALIGN_MASK;
544}
545static inline void *align_ptr(void *ptr)
546{
547 return (void *)align_val((size_t)ptr);
548}
549
550/*
551 * Retrieves the data payload buffer from an already allocated
552 * struct dm_ioctl.
553 */
554static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
555 size_t *len)
556{
557 param->data_start = align_ptr(param + 1) - (void *) param;
558
559 if (param->data_start < param_size)
560 *len = param_size - param->data_start;
561 else
562 *len = 0;
563
564 return ((void *) param) + param->data_start;
565}
566
567static bool filter_device(struct hash_cell *hc, const char *pfx_name, const char *pfx_uuid)
568{
569 const char *val;
570 size_t val_len, pfx_len;
571
572 val = hc->name;
573 val_len = strlen(val);
574 pfx_len = strnlen(pfx_name, DM_NAME_LEN);
575 if (pfx_len > val_len)
576 return false;
577 if (memcmp(val, pfx_name, pfx_len))
578 return false;
579
580 val = hc->uuid ? hc->uuid : "";
581 val_len = strlen(val);
582 pfx_len = strnlen(pfx_uuid, DM_UUID_LEN);
583 if (pfx_len > val_len)
584 return false;
585 if (memcmp(val, pfx_uuid, pfx_len))
586 return false;
587
588 return true;
589}
590
591static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_size)
592{
593 struct rb_node *n;
594 struct hash_cell *hc;
595 size_t len, needed = 0;
596 struct gendisk *disk;
597 struct dm_name_list *orig_nl, *nl, *old_nl = NULL;
598 uint32_t *event_nr;
599
600 down_write(&_hash_lock);
601
602 /*
603 * Loop through all the devices working out how much
604 * space we need.
605 */
606 for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {
607 hc = container_of(n, struct hash_cell, name_node);
608 if (!filter_device(hc, param->name, param->uuid))
609 continue;
610 needed += align_val(offsetof(struct dm_name_list, name) + strlen(hc->name) + 1);
611 needed += align_val(sizeof(uint32_t) * 2);
612 if (param->flags & DM_UUID_FLAG && hc->uuid)
613 needed += align_val(strlen(hc->uuid) + 1);
614 }
615
616 /*
617 * Grab our output buffer.
618 */
619 nl = orig_nl = get_result_buffer(param, param_size, &len);
620 if (len < needed || len < sizeof(nl->dev)) {
621 param->flags |= DM_BUFFER_FULL_FLAG;
622 goto out;
623 }
624 param->data_size = param->data_start + needed;
625
626 nl->dev = 0; /* Flags no data */
627
628 /*
629 * Now loop through filling out the names.
630 */
631 for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {
632 void *uuid_ptr;
633
634 hc = container_of(n, struct hash_cell, name_node);
635 if (!filter_device(hc, param->name, param->uuid))
636 continue;
637 if (old_nl)
638 old_nl->next = (uint32_t) ((void *) nl -
639 (void *) old_nl);
640 disk = dm_disk(hc->md);
641 nl->dev = huge_encode_dev(disk_devt(disk));
642 nl->next = 0;
643 strcpy(nl->name, hc->name);
644
645 old_nl = nl;
646 event_nr = align_ptr(nl->name + strlen(hc->name) + 1);
647 event_nr[0] = dm_get_event_nr(hc->md);
648 event_nr[1] = 0;
649 uuid_ptr = align_ptr(event_nr + 2);
650 if (param->flags & DM_UUID_FLAG) {
651 if (hc->uuid) {
652 event_nr[1] |= DM_NAME_LIST_FLAG_HAS_UUID;
653 strcpy(uuid_ptr, hc->uuid);
654 uuid_ptr = align_ptr(uuid_ptr + strlen(hc->uuid) + 1);
655 } else {
656 event_nr[1] |= DM_NAME_LIST_FLAG_DOESNT_HAVE_UUID;
657 }
658 }
659 nl = uuid_ptr;
660 }
661 /*
662 * If mismatch happens, security may be compromised due to buffer
663 * overflow, so it's better to crash.
664 */
665 BUG_ON((char *)nl - (char *)orig_nl != needed);
666
667 out:
668 up_write(&_hash_lock);
669 return 0;
670}
671
672static void list_version_get_needed(struct target_type *tt, void *needed_param)
673{
674 size_t *needed = needed_param;
675
676 *needed += sizeof(struct dm_target_versions);
677 *needed += strlen(tt->name) + 1;
678 *needed += ALIGN_MASK;
679}
680
681static void list_version_get_info(struct target_type *tt, void *param)
682{
683 struct vers_iter *info = param;
684
685 /* Check space - it might have changed since the first iteration */
686 if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 > info->end) {
687 info->flags = DM_BUFFER_FULL_FLAG;
688 return;
689 }
690
691 if (info->old_vers)
692 info->old_vers->next = (uint32_t) ((void *)info->vers - (void *)info->old_vers);
693
694 info->vers->version[0] = tt->version[0];
695 info->vers->version[1] = tt->version[1];
696 info->vers->version[2] = tt->version[2];
697 info->vers->next = 0;
698 strcpy(info->vers->name, tt->name);
699
700 info->old_vers = info->vers;
701 info->vers = align_ptr((void *)(info->vers + 1) + strlen(tt->name) + 1);
702}
703
704static int __list_versions(struct dm_ioctl *param, size_t param_size, const char *name)
705{
706 size_t len, needed = 0;
707 struct dm_target_versions *vers;
708 struct vers_iter iter_info;
709 struct target_type *tt = NULL;
710
711 if (name) {
712 tt = dm_get_target_type(name);
713 if (!tt)
714 return -EINVAL;
715 }
716
717 /*
718 * Loop through all the devices working out how much
719 * space we need.
720 */
721 if (!tt)
722 dm_target_iterate(list_version_get_needed, &needed);
723 else
724 list_version_get_needed(tt, &needed);
725
726 /*
727 * Grab our output buffer.
728 */
729 vers = get_result_buffer(param, param_size, &len);
730 if (len < needed) {
731 param->flags |= DM_BUFFER_FULL_FLAG;
732 goto out;
733 }
734 param->data_size = param->data_start + needed;
735
736 iter_info.param_size = param_size;
737 iter_info.old_vers = NULL;
738 iter_info.vers = vers;
739 iter_info.flags = 0;
740 iter_info.end = (char *)vers + needed;
741
742 /*
743 * Now loop through filling out the names & versions.
744 */
745 if (!tt)
746 dm_target_iterate(list_version_get_info, &iter_info);
747 else
748 list_version_get_info(tt, &iter_info);
749 param->flags |= iter_info.flags;
750
751 out:
752 if (tt)
753 dm_put_target_type(tt);
754 return 0;
755}
756
757static int list_versions(struct file *filp, struct dm_ioctl *param, size_t param_size)
758{
759 return __list_versions(param, param_size, NULL);
760}
761
762static int get_target_version(struct file *filp, struct dm_ioctl *param, size_t param_size)
763{
764 return __list_versions(param, param_size, param->name);
765}
766
767static int check_name(const char *name)
768{
769 if (strchr(name, '/')) {
770 DMERR("device name cannot contain '/'");
771 return -EINVAL;
772 }
773
774 if (strcmp(name, DM_CONTROL_NODE) == 0 ||
775 strcmp(name, ".") == 0 ||
776 strcmp(name, "..") == 0) {
777 DMERR("device name cannot be \"%s\", \".\", or \"..\"", DM_CONTROL_NODE);
778 return -EINVAL;
779 }
780
781 return 0;
782}
783
784/*
785 * On successful return, the caller must not attempt to acquire
786 * _hash_lock without first calling dm_put_live_table, because dm_table_destroy
787 * waits for this dm_put_live_table and could be called under this lock.
788 */
789static struct dm_table *dm_get_inactive_table(struct mapped_device *md, int *srcu_idx)
790{
791 struct hash_cell *hc;
792 struct dm_table *table = NULL;
793
794 /* increment rcu count, we don't care about the table pointer */
795 dm_get_live_table(md, srcu_idx);
796
797 down_read(&_hash_lock);
798 hc = dm_get_mdptr(md);
799 if (!hc) {
800 DMERR("device has been removed from the dev hash table.");
801 goto out;
802 }
803
804 table = hc->new_map;
805
806out:
807 up_read(&_hash_lock);
808
809 return table;
810}
811
812static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
813 struct dm_ioctl *param,
814 int *srcu_idx)
815{
816 return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
817 dm_get_inactive_table(md, srcu_idx) : dm_get_live_table(md, srcu_idx);
818}
819
820/*
821 * Fills in a dm_ioctl structure, ready for sending back to
822 * userland.
823 */
824static void __dev_status(struct mapped_device *md, struct dm_ioctl *param)
825{
826 struct gendisk *disk = dm_disk(md);
827 struct dm_table *table;
828 int srcu_idx;
829
830 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
831 DM_ACTIVE_PRESENT_FLAG | DM_INTERNAL_SUSPEND_FLAG);
832
833 if (dm_suspended_md(md))
834 param->flags |= DM_SUSPEND_FLAG;
835
836 if (dm_suspended_internally_md(md))
837 param->flags |= DM_INTERNAL_SUSPEND_FLAG;
838
839 if (dm_test_deferred_remove_flag(md))
840 param->flags |= DM_DEFERRED_REMOVE;
841
842 param->dev = huge_encode_dev(disk_devt(disk));
843
844 /*
845 * Yes, this will be out of date by the time it gets back
846 * to userland, but it is still very useful for
847 * debugging.
848 */
849 param->open_count = dm_open_count(md);
850
851 param->event_nr = dm_get_event_nr(md);
852 param->target_count = 0;
853
854 table = dm_get_live_table(md, &srcu_idx);
855 if (table) {
856 if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
857 if (get_disk_ro(disk))
858 param->flags |= DM_READONLY_FLAG;
859 param->target_count = table->num_targets;
860 }
861
862 param->flags |= DM_ACTIVE_PRESENT_FLAG;
863 }
864 dm_put_live_table(md, srcu_idx);
865
866 if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
867 int srcu_idx;
868
869 table = dm_get_inactive_table(md, &srcu_idx);
870 if (table) {
871 if (!(dm_table_get_mode(table) & BLK_OPEN_WRITE))
872 param->flags |= DM_READONLY_FLAG;
873 param->target_count = table->num_targets;
874 }
875 dm_put_live_table(md, srcu_idx);
876 }
877}
878
879static int dev_create(struct file *filp, struct dm_ioctl *param, size_t param_size)
880{
881 int r, m = DM_ANY_MINOR;
882 struct mapped_device *md;
883
884 r = check_name(param->name);
885 if (r)
886 return r;
887
888 if (param->flags & DM_PERSISTENT_DEV_FLAG)
889 m = MINOR(huge_decode_dev(param->dev));
890
891 r = dm_create(m, &md);
892 if (r)
893 return r;
894
895 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
896 if (r) {
897 dm_put(md);
898 dm_destroy(md);
899 return r;
900 }
901
902 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
903
904 __dev_status(md, param);
905
906 dm_put(md);
907
908 return 0;
909}
910
911/*
912 * Always use UUID for lookups if it's present, otherwise use name or dev.
913 */
914static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
915{
916 struct hash_cell *hc = NULL;
917
918 if (*param->uuid) {
919 if (*param->name || param->dev) {
920 DMERR("Invalid ioctl structure: uuid %s, name %s, dev %llx",
921 param->uuid, param->name, (unsigned long long)param->dev);
922 return NULL;
923 }
924
925 hc = __get_uuid_cell(param->uuid);
926 if (!hc)
927 return NULL;
928 } else if (*param->name) {
929 if (param->dev) {
930 DMERR("Invalid ioctl structure: name %s, dev %llx",
931 param->name, (unsigned long long)param->dev);
932 return NULL;
933 }
934
935 hc = __get_name_cell(param->name);
936 if (!hc)
937 return NULL;
938 } else if (param->dev) {
939 hc = __get_dev_cell(param->dev);
940 if (!hc)
941 return NULL;
942 } else
943 return NULL;
944
945 /*
946 * Sneakily write in both the name and the uuid
947 * while we have the cell.
948 */
949 strscpy(param->name, hc->name, sizeof(param->name));
950 if (hc->uuid)
951 strscpy(param->uuid, hc->uuid, sizeof(param->uuid));
952 else
953 param->uuid[0] = '\0';
954
955 if (hc->new_map)
956 param->flags |= DM_INACTIVE_PRESENT_FLAG;
957 else
958 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
959
960 return hc;
961}
962
963static struct mapped_device *find_device(struct dm_ioctl *param)
964{
965 struct hash_cell *hc;
966 struct mapped_device *md = NULL;
967
968 down_read(&_hash_lock);
969 hc = __find_device_hash_cell(param);
970 if (hc)
971 md = hc->md;
972 up_read(&_hash_lock);
973
974 return md;
975}
976
977static int dev_remove(struct file *filp, struct dm_ioctl *param, size_t param_size)
978{
979 struct hash_cell *hc;
980 struct mapped_device *md;
981 int r;
982 struct dm_table *t;
983
984 down_write(&_hash_lock);
985 hc = __find_device_hash_cell(param);
986
987 if (!hc) {
988 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
989 up_write(&_hash_lock);
990 return -ENXIO;
991 }
992
993 md = hc->md;
994
995 /*
996 * Ensure the device is not open and nothing further can open it.
997 */
998 r = dm_lock_for_deletion(md, !!(param->flags & DM_DEFERRED_REMOVE), false);
999 if (r) {
1000 if (r == -EBUSY && param->flags & DM_DEFERRED_REMOVE) {
1001 up_write(&_hash_lock);
1002 dm_put(md);
1003 return 0;
1004 }
1005 DMDEBUG_LIMIT("unable to remove open device %s", hc->name);
1006 up_write(&_hash_lock);
1007 dm_put(md);
1008 return r;
1009 }
1010
1011 t = __hash_remove(hc);
1012 up_write(&_hash_lock);
1013
1014 if (t) {
1015 dm_sync_table(md);
1016 dm_table_destroy(t);
1017 }
1018
1019 param->flags &= ~DM_DEFERRED_REMOVE;
1020
1021 dm_ima_measure_on_device_remove(md, false);
1022
1023 if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr, false))
1024 param->flags |= DM_UEVENT_GENERATED_FLAG;
1025
1026 dm_put(md);
1027 dm_destroy(md);
1028 return 0;
1029}
1030
1031/*
1032 * Check a string doesn't overrun the chunk of
1033 * memory we copied from userland.
1034 */
1035static int invalid_str(char *str, void *end)
1036{
1037 while ((void *) str < end)
1038 if (!*str++)
1039 return 0;
1040
1041 return -EINVAL;
1042}
1043
1044static int dev_rename(struct file *filp, struct dm_ioctl *param, size_t param_size)
1045{
1046 int r;
1047 char *new_data = (char *) param + param->data_start;
1048 struct mapped_device *md;
1049 unsigned int change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
1050
1051 if (new_data < param->data ||
1052 invalid_str(new_data, (void *) param + param_size) || !*new_data ||
1053 strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
1054 DMERR("Invalid new mapped device name or uuid string supplied.");
1055 return -EINVAL;
1056 }
1057
1058 if (!change_uuid) {
1059 r = check_name(new_data);
1060 if (r)
1061 return r;
1062 }
1063
1064 md = dm_hash_rename(param, new_data);
1065 if (IS_ERR(md))
1066 return PTR_ERR(md);
1067
1068 __dev_status(md, param);
1069 dm_put(md);
1070
1071 return 0;
1072}
1073
1074static int dev_set_geometry(struct file *filp, struct dm_ioctl *param, size_t param_size)
1075{
1076 int r = -EINVAL, x;
1077 struct mapped_device *md;
1078 struct hd_geometry geometry;
1079 unsigned long indata[4];
1080 char *geostr = (char *) param + param->data_start;
1081 char dummy;
1082
1083 md = find_device(param);
1084 if (!md)
1085 return -ENXIO;
1086
1087 if (geostr < param->data ||
1088 invalid_str(geostr, (void *) param + param_size)) {
1089 DMERR("Invalid geometry supplied.");
1090 goto out;
1091 }
1092
1093 x = sscanf(geostr, "%lu %lu %lu %lu%c", indata,
1094 indata + 1, indata + 2, indata + 3, &dummy);
1095
1096 if (x != 4) {
1097 DMERR("Unable to interpret geometry settings.");
1098 goto out;
1099 }
1100
1101 if (indata[0] > 65535 || indata[1] > 255 || indata[2] > 255) {
1102 DMERR("Geometry exceeds range limits.");
1103 goto out;
1104 }
1105
1106 geometry.cylinders = indata[0];
1107 geometry.heads = indata[1];
1108 geometry.sectors = indata[2];
1109 geometry.start = indata[3];
1110
1111 r = dm_set_geometry(md, &geometry);
1112
1113 param->data_size = 0;
1114
1115out:
1116 dm_put(md);
1117 return r;
1118}
1119
1120static int do_suspend(struct dm_ioctl *param)
1121{
1122 int r = 0;
1123 unsigned int suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
1124 struct mapped_device *md;
1125
1126 md = find_device(param);
1127 if (!md)
1128 return -ENXIO;
1129
1130 if (param->flags & DM_SKIP_LOCKFS_FLAG)
1131 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
1132 if (param->flags & DM_NOFLUSH_FLAG)
1133 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
1134
1135 if (!dm_suspended_md(md)) {
1136 r = dm_suspend(md, suspend_flags);
1137 if (r)
1138 goto out;
1139 }
1140
1141 __dev_status(md, param);
1142
1143out:
1144 dm_put(md);
1145
1146 return r;
1147}
1148
1149static int do_resume(struct dm_ioctl *param)
1150{
1151 int r = 0;
1152 unsigned int suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
1153 struct hash_cell *hc;
1154 struct mapped_device *md;
1155 struct dm_table *new_map, *old_map = NULL;
1156 bool need_resize_uevent = false;
1157
1158 down_write(&_hash_lock);
1159
1160 hc = __find_device_hash_cell(param);
1161 if (!hc) {
1162 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1163 up_write(&_hash_lock);
1164 return -ENXIO;
1165 }
1166
1167 md = hc->md;
1168
1169 new_map = hc->new_map;
1170 hc->new_map = NULL;
1171 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1172
1173 up_write(&_hash_lock);
1174
1175 /* Do we need to load a new map ? */
1176 if (new_map) {
1177 sector_t old_size, new_size;
1178
1179 /* Suspend if it isn't already suspended */
1180 if (param->flags & DM_SKIP_LOCKFS_FLAG)
1181 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
1182 if (param->flags & DM_NOFLUSH_FLAG)
1183 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
1184 if (!dm_suspended_md(md)) {
1185 r = dm_suspend(md, suspend_flags);
1186 if (r) {
1187 down_write(&_hash_lock);
1188 hc = dm_get_mdptr(md);
1189 if (hc && !hc->new_map) {
1190 hc->new_map = new_map;
1191 new_map = NULL;
1192 } else {
1193 r = -ENXIO;
1194 }
1195 up_write(&_hash_lock);
1196 if (new_map) {
1197 dm_sync_table(md);
1198 dm_table_destroy(new_map);
1199 }
1200 dm_put(md);
1201 return r;
1202 }
1203 }
1204
1205 old_size = dm_get_size(md);
1206 old_map = dm_swap_table(md, new_map);
1207 if (IS_ERR(old_map)) {
1208 dm_sync_table(md);
1209 dm_table_destroy(new_map);
1210 dm_put(md);
1211 return PTR_ERR(old_map);
1212 }
1213 new_size = dm_get_size(md);
1214 if (old_size && new_size && old_size != new_size)
1215 need_resize_uevent = true;
1216
1217 if (dm_table_get_mode(new_map) & BLK_OPEN_WRITE)
1218 set_disk_ro(dm_disk(md), 0);
1219 else
1220 set_disk_ro(dm_disk(md), 1);
1221 }
1222
1223 if (dm_suspended_md(md)) {
1224 r = dm_resume(md);
1225 if (!r) {
1226 dm_ima_measure_on_device_resume(md, new_map ? true : false);
1227
1228 if (!dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr, need_resize_uevent))
1229 param->flags |= DM_UEVENT_GENERATED_FLAG;
1230 }
1231 }
1232
1233 /*
1234 * Since dm_swap_table synchronizes RCU, nobody should be in
1235 * read-side critical section already.
1236 */
1237 if (old_map)
1238 dm_table_destroy(old_map);
1239
1240 if (!r)
1241 __dev_status(md, param);
1242
1243 dm_put(md);
1244 return r;
1245}
1246
1247/*
1248 * Set or unset the suspension state of a device.
1249 * If the device already is in the requested state we just return its status.
1250 */
1251static int dev_suspend(struct file *filp, struct dm_ioctl *param, size_t param_size)
1252{
1253 if (param->flags & DM_SUSPEND_FLAG)
1254 return do_suspend(param);
1255
1256 return do_resume(param);
1257}
1258
1259/*
1260 * Copies device info back to user space, used by
1261 * the create and info ioctls.
1262 */
1263static int dev_status(struct file *filp, struct dm_ioctl *param, size_t param_size)
1264{
1265 struct mapped_device *md;
1266
1267 md = find_device(param);
1268 if (!md)
1269 return -ENXIO;
1270
1271 __dev_status(md, param);
1272 dm_put(md);
1273
1274 return 0;
1275}
1276
1277/*
1278 * Build up the status struct for each target
1279 */
1280static void retrieve_status(struct dm_table *table,
1281 struct dm_ioctl *param, size_t param_size)
1282{
1283 unsigned int i, num_targets;
1284 struct dm_target_spec *spec;
1285 char *outbuf, *outptr;
1286 status_type_t type;
1287 size_t remaining, len, used = 0;
1288 unsigned int status_flags = 0;
1289
1290 outptr = outbuf = get_result_buffer(param, param_size, &len);
1291
1292 if (param->flags & DM_STATUS_TABLE_FLAG)
1293 type = STATUSTYPE_TABLE;
1294 else if (param->flags & DM_IMA_MEASUREMENT_FLAG)
1295 type = STATUSTYPE_IMA;
1296 else
1297 type = STATUSTYPE_INFO;
1298
1299 /* Get all the target info */
1300 num_targets = table->num_targets;
1301 for (i = 0; i < num_targets; i++) {
1302 struct dm_target *ti = dm_table_get_target(table, i);
1303 size_t l;
1304
1305 remaining = len - (outptr - outbuf);
1306 if (remaining <= sizeof(struct dm_target_spec)) {
1307 param->flags |= DM_BUFFER_FULL_FLAG;
1308 break;
1309 }
1310
1311 spec = (struct dm_target_spec *) outptr;
1312
1313 spec->status = 0;
1314 spec->sector_start = ti->begin;
1315 spec->length = ti->len;
1316 strscpy_pad(spec->target_type, ti->type->name,
1317 sizeof(spec->target_type));
1318
1319 outptr += sizeof(struct dm_target_spec);
1320 remaining = len - (outptr - outbuf);
1321 if (remaining <= 0) {
1322 param->flags |= DM_BUFFER_FULL_FLAG;
1323 break;
1324 }
1325
1326 /* Get the status/table string from the target driver */
1327 if (ti->type->status) {
1328 if (param->flags & DM_NOFLUSH_FLAG)
1329 status_flags |= DM_STATUS_NOFLUSH_FLAG;
1330 ti->type->status(ti, type, status_flags, outptr, remaining);
1331 } else
1332 outptr[0] = '\0';
1333
1334 l = strlen(outptr) + 1;
1335 if (l == remaining) {
1336 param->flags |= DM_BUFFER_FULL_FLAG;
1337 break;
1338 }
1339
1340 outptr += l;
1341 used = param->data_start + (outptr - outbuf);
1342
1343 outptr = align_ptr(outptr);
1344 spec->next = outptr - outbuf;
1345 }
1346
1347 if (used)
1348 param->data_size = used;
1349
1350 param->target_count = num_targets;
1351}
1352
1353/*
1354 * Wait for a device to report an event
1355 */
1356static int dev_wait(struct file *filp, struct dm_ioctl *param, size_t param_size)
1357{
1358 int r = 0;
1359 struct mapped_device *md;
1360 struct dm_table *table;
1361 int srcu_idx;
1362
1363 md = find_device(param);
1364 if (!md)
1365 return -ENXIO;
1366
1367 /*
1368 * Wait for a notification event
1369 */
1370 if (dm_wait_event(md, param->event_nr)) {
1371 r = -ERESTARTSYS;
1372 goto out;
1373 }
1374
1375 /*
1376 * The userland program is going to want to know what
1377 * changed to trigger the event, so we may as well tell
1378 * him and save an ioctl.
1379 */
1380 __dev_status(md, param);
1381
1382 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1383 if (table)
1384 retrieve_status(table, param, param_size);
1385 dm_put_live_table(md, srcu_idx);
1386
1387out:
1388 dm_put(md);
1389
1390 return r;
1391}
1392
1393/*
1394 * Remember the global event number and make it possible to poll
1395 * for further events.
1396 */
1397static int dev_arm_poll(struct file *filp, struct dm_ioctl *param, size_t param_size)
1398{
1399 struct dm_file *priv = filp->private_data;
1400
1401 priv->global_event_nr = atomic_read(&dm_global_event_nr);
1402
1403 return 0;
1404}
1405
1406static inline blk_mode_t get_mode(struct dm_ioctl *param)
1407{
1408 blk_mode_t mode = BLK_OPEN_READ | BLK_OPEN_WRITE;
1409
1410 if (param->flags & DM_READONLY_FLAG)
1411 mode = BLK_OPEN_READ;
1412
1413 return mode;
1414}
1415
1416static int next_target(struct dm_target_spec *last, uint32_t next, const char *end,
1417 struct dm_target_spec **spec, char **target_params)
1418{
1419 static_assert(__alignof__(struct dm_target_spec) <= 8,
1420 "struct dm_target_spec must not require more than 8-byte alignment");
1421
1422 /*
1423 * Number of bytes remaining, starting with last. This is always
1424 * sizeof(struct dm_target_spec) or more, as otherwise *last was
1425 * out of bounds already.
1426 */
1427 size_t remaining = end - (char *)last;
1428
1429 /*
1430 * There must be room for both the next target spec and the
1431 * NUL-terminator of the target itself.
1432 */
1433 if (remaining - sizeof(struct dm_target_spec) <= next) {
1434 DMERR("Target spec extends beyond end of parameters");
1435 return -EINVAL;
1436 }
1437
1438 if (next % __alignof__(struct dm_target_spec)) {
1439 DMERR("Next dm_target_spec (offset %u) is not %zu-byte aligned",
1440 next, __alignof__(struct dm_target_spec));
1441 return -EINVAL;
1442 }
1443
1444 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1445 *target_params = (char *) (*spec + 1);
1446
1447 return 0;
1448}
1449
1450static int populate_table(struct dm_table *table,
1451 struct dm_ioctl *param, size_t param_size)
1452{
1453 int r;
1454 unsigned int i = 0;
1455 struct dm_target_spec *spec = (struct dm_target_spec *) param;
1456 uint32_t next = param->data_start;
1457 const char *const end = (const char *) param + param_size;
1458 char *target_params;
1459 size_t min_size = sizeof(struct dm_ioctl);
1460
1461 if (!param->target_count) {
1462 DMERR("%s: no targets specified", __func__);
1463 return -EINVAL;
1464 }
1465
1466 for (i = 0; i < param->target_count; i++) {
1467 const char *nul_terminator;
1468
1469 if (next < min_size) {
1470 DMERR("%s: next target spec (offset %u) overlaps %s",
1471 __func__, next, i ? "previous target" : "'struct dm_ioctl'");
1472 return -EINVAL;
1473 }
1474
1475 r = next_target(spec, next, end, &spec, &target_params);
1476 if (r) {
1477 DMERR("unable to find target");
1478 return r;
1479 }
1480
1481 nul_terminator = memchr(target_params, 0, (size_t)(end - target_params));
1482 if (nul_terminator == NULL) {
1483 DMERR("%s: target parameters not NUL-terminated", __func__);
1484 return -EINVAL;
1485 }
1486
1487 /* Add 1 for NUL terminator */
1488 min_size = (size_t)(nul_terminator - (const char *)spec) + 1;
1489
1490 r = dm_table_add_target(table, spec->target_type,
1491 (sector_t) spec->sector_start,
1492 (sector_t) spec->length,
1493 target_params);
1494 if (r) {
1495 DMERR("error adding target to table");
1496 return r;
1497 }
1498
1499 next = spec->next;
1500 }
1501
1502 return dm_table_complete(table);
1503}
1504
1505static bool is_valid_type(enum dm_queue_mode cur, enum dm_queue_mode new)
1506{
1507 if (cur == new ||
1508 (cur == DM_TYPE_BIO_BASED && new == DM_TYPE_DAX_BIO_BASED))
1509 return true;
1510
1511 return false;
1512}
1513
1514static int table_load(struct file *filp, struct dm_ioctl *param, size_t param_size)
1515{
1516 int r;
1517 struct hash_cell *hc;
1518 struct dm_table *t, *old_map = NULL;
1519 struct mapped_device *md;
1520 struct target_type *immutable_target_type;
1521
1522 md = find_device(param);
1523 if (!md)
1524 return -ENXIO;
1525
1526 r = dm_table_create(&t, get_mode(param), param->target_count, md);
1527 if (r)
1528 goto err;
1529
1530 /* Protect md->type and md->queue against concurrent table loads. */
1531 dm_lock_md_type(md);
1532 r = populate_table(t, param, param_size);
1533 if (r)
1534 goto err_unlock_md_type;
1535
1536 dm_ima_measure_on_table_load(t, STATUSTYPE_IMA);
1537
1538 immutable_target_type = dm_get_immutable_target_type(md);
1539 if (immutable_target_type &&
1540 (immutable_target_type != dm_table_get_immutable_target_type(t)) &&
1541 !dm_table_get_wildcard_target(t)) {
1542 DMERR("can't replace immutable target type %s",
1543 immutable_target_type->name);
1544 r = -EINVAL;
1545 goto err_unlock_md_type;
1546 }
1547
1548 if (dm_get_md_type(md) == DM_TYPE_NONE) {
1549 /* setup md->queue to reflect md's type (may block) */
1550 r = dm_setup_md_queue(md, t);
1551 if (r) {
1552 DMERR("unable to set up device queue for new table.");
1553 goto err_unlock_md_type;
1554 }
1555 } else if (!is_valid_type(dm_get_md_type(md), dm_table_get_type(t))) {
1556 DMERR("can't change device type (old=%u vs new=%u) after initial table load.",
1557 dm_get_md_type(md), dm_table_get_type(t));
1558 r = -EINVAL;
1559 goto err_unlock_md_type;
1560 }
1561
1562 dm_unlock_md_type(md);
1563
1564 /* stage inactive table */
1565 down_write(&_hash_lock);
1566 hc = dm_get_mdptr(md);
1567 if (!hc) {
1568 DMERR("device has been removed from the dev hash table.");
1569 up_write(&_hash_lock);
1570 r = -ENXIO;
1571 goto err_destroy_table;
1572 }
1573
1574 if (hc->new_map)
1575 old_map = hc->new_map;
1576 hc->new_map = t;
1577 up_write(&_hash_lock);
1578
1579 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1580 __dev_status(md, param);
1581
1582 if (old_map) {
1583 dm_sync_table(md);
1584 dm_table_destroy(old_map);
1585 }
1586
1587 dm_put(md);
1588
1589 return 0;
1590
1591err_unlock_md_type:
1592 dm_unlock_md_type(md);
1593err_destroy_table:
1594 dm_table_destroy(t);
1595err:
1596 dm_put(md);
1597
1598 return r;
1599}
1600
1601static int table_clear(struct file *filp, struct dm_ioctl *param, size_t param_size)
1602{
1603 struct hash_cell *hc;
1604 struct mapped_device *md;
1605 struct dm_table *old_map = NULL;
1606 bool has_new_map = false;
1607
1608 down_write(&_hash_lock);
1609
1610 hc = __find_device_hash_cell(param);
1611 if (!hc) {
1612 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1613 up_write(&_hash_lock);
1614 return -ENXIO;
1615 }
1616
1617 if (hc->new_map) {
1618 old_map = hc->new_map;
1619 hc->new_map = NULL;
1620 has_new_map = true;
1621 }
1622
1623 md = hc->md;
1624 up_write(&_hash_lock);
1625
1626 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1627 __dev_status(md, param);
1628
1629 if (old_map) {
1630 dm_sync_table(md);
1631 dm_table_destroy(old_map);
1632 }
1633 dm_ima_measure_on_table_clear(md, has_new_map);
1634 dm_put(md);
1635
1636 return 0;
1637}
1638
1639/*
1640 * Retrieves a list of devices used by a particular dm device.
1641 */
1642static void retrieve_deps(struct dm_table *table,
1643 struct dm_ioctl *param, size_t param_size)
1644{
1645 unsigned int count = 0;
1646 struct list_head *tmp;
1647 size_t len, needed;
1648 struct dm_dev_internal *dd;
1649 struct dm_target_deps *deps;
1650
1651 down_read(&table->devices_lock);
1652
1653 deps = get_result_buffer(param, param_size, &len);
1654
1655 /*
1656 * Count the devices.
1657 */
1658 list_for_each(tmp, dm_table_get_devices(table))
1659 count++;
1660
1661 /*
1662 * Check we have enough space.
1663 */
1664 needed = struct_size(deps, dev, count);
1665 if (len < needed) {
1666 param->flags |= DM_BUFFER_FULL_FLAG;
1667 goto out;
1668 }
1669
1670 /*
1671 * Fill in the devices.
1672 */
1673 deps->count = count;
1674 count = 0;
1675 list_for_each_entry(dd, dm_table_get_devices(table), list)
1676 deps->dev[count++] = huge_encode_dev(dd->dm_dev->bdev->bd_dev);
1677
1678 param->data_size = param->data_start + needed;
1679
1680out:
1681 up_read(&table->devices_lock);
1682}
1683
1684static int table_deps(struct file *filp, struct dm_ioctl *param, size_t param_size)
1685{
1686 struct mapped_device *md;
1687 struct dm_table *table;
1688 int srcu_idx;
1689
1690 md = find_device(param);
1691 if (!md)
1692 return -ENXIO;
1693
1694 __dev_status(md, param);
1695
1696 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1697 if (table)
1698 retrieve_deps(table, param, param_size);
1699 dm_put_live_table(md, srcu_idx);
1700
1701 dm_put(md);
1702
1703 return 0;
1704}
1705
1706/*
1707 * Return the status of a device as a text string for each
1708 * target.
1709 */
1710static int table_status(struct file *filp, struct dm_ioctl *param, size_t param_size)
1711{
1712 struct mapped_device *md;
1713 struct dm_table *table;
1714 int srcu_idx;
1715
1716 md = find_device(param);
1717 if (!md)
1718 return -ENXIO;
1719
1720 __dev_status(md, param);
1721
1722 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1723 if (table)
1724 retrieve_status(table, param, param_size);
1725 dm_put_live_table(md, srcu_idx);
1726
1727 dm_put(md);
1728
1729 return 0;
1730}
1731
1732/*
1733 * Process device-mapper dependent messages. Messages prefixed with '@'
1734 * are processed by the DM core. All others are delivered to the target.
1735 * Returns a number <= 1 if message was processed by device mapper.
1736 * Returns 2 if message should be delivered to the target.
1737 */
1738static int message_for_md(struct mapped_device *md, unsigned int argc, char **argv,
1739 char *result, unsigned int maxlen)
1740{
1741 int r;
1742
1743 if (**argv != '@')
1744 return 2; /* no '@' prefix, deliver to target */
1745
1746 if (!strcasecmp(argv[0], "@cancel_deferred_remove")) {
1747 if (argc != 1) {
1748 DMERR("Invalid arguments for @cancel_deferred_remove");
1749 return -EINVAL;
1750 }
1751 return dm_cancel_deferred_remove(md);
1752 }
1753
1754 r = dm_stats_message(md, argc, argv, result, maxlen);
1755 if (r < 2)
1756 return r;
1757
1758 DMERR("Unsupported message sent to DM core: %s", argv[0]);
1759 return -EINVAL;
1760}
1761
1762/*
1763 * Pass a message to the target that's at the supplied device offset.
1764 */
1765static int target_message(struct file *filp, struct dm_ioctl *param, size_t param_size)
1766{
1767 int r, argc;
1768 char **argv;
1769 struct mapped_device *md;
1770 struct dm_table *table;
1771 struct dm_target *ti;
1772 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1773 size_t maxlen;
1774 char *result = get_result_buffer(param, param_size, &maxlen);
1775 int srcu_idx;
1776
1777 md = find_device(param);
1778 if (!md)
1779 return -ENXIO;
1780
1781 if (tmsg < (struct dm_target_msg *) param->data ||
1782 invalid_str(tmsg->message, (void *) param + param_size)) {
1783 DMERR("Invalid target message parameters.");
1784 r = -EINVAL;
1785 goto out;
1786 }
1787
1788 r = dm_split_args(&argc, &argv, tmsg->message);
1789 if (r) {
1790 DMERR("Failed to split target message parameters");
1791 goto out;
1792 }
1793
1794 if (!argc) {
1795 DMERR("Empty message received.");
1796 r = -EINVAL;
1797 goto out_argv;
1798 }
1799
1800 r = message_for_md(md, argc, argv, result, maxlen);
1801 if (r <= 1)
1802 goto out_argv;
1803
1804 table = dm_get_live_table(md, &srcu_idx);
1805 if (!table)
1806 goto out_table;
1807
1808 if (dm_deleting_md(md)) {
1809 r = -ENXIO;
1810 goto out_table;
1811 }
1812
1813 ti = dm_table_find_target(table, tmsg->sector);
1814 if (!ti) {
1815 DMERR("Target message sector outside device.");
1816 r = -EINVAL;
1817 } else if (ti->type->message)
1818 r = ti->type->message(ti, argc, argv, result, maxlen);
1819 else {
1820 DMERR("Target type does not support messages");
1821 r = -EINVAL;
1822 }
1823
1824 out_table:
1825 dm_put_live_table(md, srcu_idx);
1826 out_argv:
1827 kfree(argv);
1828 out:
1829 if (r >= 0)
1830 __dev_status(md, param);
1831
1832 if (r == 1) {
1833 param->flags |= DM_DATA_OUT_FLAG;
1834 if (dm_message_test_buffer_overflow(result, maxlen))
1835 param->flags |= DM_BUFFER_FULL_FLAG;
1836 else
1837 param->data_size = param->data_start + strlen(result) + 1;
1838 r = 0;
1839 }
1840
1841 dm_put(md);
1842 return r;
1843}
1844
1845/*
1846 * The ioctl parameter block consists of two parts, a dm_ioctl struct
1847 * followed by a data buffer. This flag is set if the second part,
1848 * which has a variable size, is not used by the function processing
1849 * the ioctl.
1850 */
1851#define IOCTL_FLAGS_NO_PARAMS 1
1852#define IOCTL_FLAGS_ISSUE_GLOBAL_EVENT 2
1853
1854/*
1855 *---------------------------------------------------------------
1856 * Implementation of open/close/ioctl on the special char device.
1857 *---------------------------------------------------------------
1858 */
1859static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags)
1860{
1861 static const struct {
1862 int cmd;
1863 int flags;
1864 ioctl_fn fn;
1865 } _ioctls[] = {
1866 {DM_VERSION_CMD, 0, NULL}, /* version is dealt with elsewhere */
1867 {DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, remove_all},
1868 {DM_LIST_DEVICES_CMD, 0, list_devices},
1869
1870 {DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_create},
1871 {DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_remove},
1872 {DM_DEV_RENAME_CMD, IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_rename},
1873 {DM_DEV_SUSPEND_CMD, IOCTL_FLAGS_NO_PARAMS, dev_suspend},
1874 {DM_DEV_STATUS_CMD, IOCTL_FLAGS_NO_PARAMS, dev_status},
1875 {DM_DEV_WAIT_CMD, 0, dev_wait},
1876
1877 {DM_TABLE_LOAD_CMD, 0, table_load},
1878 {DM_TABLE_CLEAR_CMD, IOCTL_FLAGS_NO_PARAMS, table_clear},
1879 {DM_TABLE_DEPS_CMD, 0, table_deps},
1880 {DM_TABLE_STATUS_CMD, 0, table_status},
1881
1882 {DM_LIST_VERSIONS_CMD, 0, list_versions},
1883
1884 {DM_TARGET_MSG_CMD, 0, target_message},
1885 {DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry},
1886 {DM_DEV_ARM_POLL_CMD, IOCTL_FLAGS_NO_PARAMS, dev_arm_poll},
1887 {DM_GET_TARGET_VERSION_CMD, 0, get_target_version},
1888 };
1889
1890 if (unlikely(cmd >= ARRAY_SIZE(_ioctls)))
1891 return NULL;
1892
1893 cmd = array_index_nospec(cmd, ARRAY_SIZE(_ioctls));
1894 *ioctl_flags = _ioctls[cmd].flags;
1895 return _ioctls[cmd].fn;
1896}
1897
1898/*
1899 * As well as checking the version compatibility this always
1900 * copies the kernel interface version out.
1901 */
1902static int check_version(unsigned int cmd, struct dm_ioctl __user *user,
1903 struct dm_ioctl *kernel_params)
1904{
1905 int r = 0;
1906
1907 /* Make certain version is first member of dm_ioctl struct */
1908 BUILD_BUG_ON(offsetof(struct dm_ioctl, version) != 0);
1909
1910 if (copy_from_user(kernel_params->version, user->version, sizeof(kernel_params->version)))
1911 return -EFAULT;
1912
1913 if ((kernel_params->version[0] != DM_VERSION_MAJOR) ||
1914 (kernel_params->version[1] > DM_VERSION_MINOR)) {
1915 DMERR_LIMIT("ioctl interface mismatch: kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1916 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1917 DM_VERSION_PATCHLEVEL,
1918 kernel_params->version[0],
1919 kernel_params->version[1],
1920 kernel_params->version[2],
1921 cmd);
1922 r = -EINVAL;
1923 }
1924
1925 /*
1926 * Fill in the kernel version.
1927 */
1928 kernel_params->version[0] = DM_VERSION_MAJOR;
1929 kernel_params->version[1] = DM_VERSION_MINOR;
1930 kernel_params->version[2] = DM_VERSION_PATCHLEVEL;
1931 if (copy_to_user(user->version, kernel_params->version, sizeof(kernel_params->version)))
1932 return -EFAULT;
1933
1934 return r;
1935}
1936
1937#define DM_PARAMS_MALLOC 0x0001 /* Params allocated with kvmalloc() */
1938#define DM_WIPE_BUFFER 0x0010 /* Wipe input buffer before returning from ioctl */
1939
1940static void free_params(struct dm_ioctl *param, size_t param_size, int param_flags)
1941{
1942 if (param_flags & DM_WIPE_BUFFER)
1943 memset(param, 0, param_size);
1944
1945 if (param_flags & DM_PARAMS_MALLOC)
1946 kvfree(param);
1947}
1948
1949static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel,
1950 int ioctl_flags, struct dm_ioctl **param, int *param_flags)
1951{
1952 struct dm_ioctl *dmi;
1953 int secure_data;
1954 const size_t minimum_data_size = offsetof(struct dm_ioctl, data);
1955
1956 /* check_version() already copied version from userspace, avoid TOCTOU */
1957 if (copy_from_user((char *)param_kernel + sizeof(param_kernel->version),
1958 (char __user *)user + sizeof(param_kernel->version),
1959 minimum_data_size - sizeof(param_kernel->version)))
1960 return -EFAULT;
1961
1962 if (unlikely(param_kernel->data_size < minimum_data_size) ||
1963 unlikely(param_kernel->data_size > DM_MAX_TARGETS * DM_MAX_TARGET_PARAMS)) {
1964 DMERR_LIMIT("Invalid data size in the ioctl structure: %u",
1965 param_kernel->data_size);
1966 return -EINVAL;
1967 }
1968
1969 secure_data = param_kernel->flags & DM_SECURE_DATA_FLAG;
1970
1971 *param_flags = secure_data ? DM_WIPE_BUFFER : 0;
1972
1973 if (ioctl_flags & IOCTL_FLAGS_NO_PARAMS) {
1974 dmi = param_kernel;
1975 dmi->data_size = minimum_data_size;
1976 goto data_copied;
1977 }
1978
1979 /*
1980 * Use __GFP_HIGH to avoid low memory issues when a device is
1981 * suspended and the ioctl is needed to resume it.
1982 * Use kmalloc() rather than vmalloc() when we can.
1983 */
1984 dmi = NULL;
1985 dmi = kvmalloc(param_kernel->data_size, GFP_NOIO | __GFP_HIGH);
1986
1987 if (!dmi) {
1988 if (secure_data && clear_user(user, param_kernel->data_size))
1989 return -EFAULT;
1990 return -ENOMEM;
1991 }
1992
1993 *param_flags |= DM_PARAMS_MALLOC;
1994
1995 /* Copy from param_kernel (which was already copied from user) */
1996 memcpy(dmi, param_kernel, minimum_data_size);
1997
1998 if (copy_from_user(&dmi->data, (char __user *)user + minimum_data_size,
1999 param_kernel->data_size - minimum_data_size))
2000 goto bad;
2001data_copied:
2002 /* Wipe the user buffer so we do not return it to userspace */
2003 if (secure_data && clear_user(user, param_kernel->data_size))
2004 goto bad;
2005
2006 *param = dmi;
2007 return 0;
2008
2009bad:
2010 free_params(dmi, param_kernel->data_size, *param_flags);
2011
2012 return -EFAULT;
2013}
2014
2015static int validate_params(uint cmd, struct dm_ioctl *param)
2016{
2017 /* Always clear this flag */
2018 param->flags &= ~DM_BUFFER_FULL_FLAG;
2019 param->flags &= ~DM_UEVENT_GENERATED_FLAG;
2020 param->flags &= ~DM_SECURE_DATA_FLAG;
2021 param->flags &= ~DM_DATA_OUT_FLAG;
2022
2023 /* Ignores parameters */
2024 if (cmd == DM_REMOVE_ALL_CMD ||
2025 cmd == DM_LIST_DEVICES_CMD ||
2026 cmd == DM_LIST_VERSIONS_CMD)
2027 return 0;
2028
2029 if (cmd == DM_DEV_CREATE_CMD) {
2030 if (!*param->name) {
2031 DMERR("name not supplied when creating device");
2032 return -EINVAL;
2033 }
2034 } else if (*param->uuid && *param->name) {
2035 DMERR("only supply one of name or uuid, cmd(%u)", cmd);
2036 return -EINVAL;
2037 }
2038
2039 /* Ensure strings are terminated */
2040 param->name[DM_NAME_LEN - 1] = '\0';
2041 param->uuid[DM_UUID_LEN - 1] = '\0';
2042
2043 return 0;
2044}
2045
2046static int ctl_ioctl(struct file *file, uint command, struct dm_ioctl __user *user)
2047{
2048 int r = 0;
2049 int ioctl_flags;
2050 int param_flags;
2051 unsigned int cmd;
2052 struct dm_ioctl *param;
2053 ioctl_fn fn = NULL;
2054 size_t input_param_size;
2055 struct dm_ioctl param_kernel;
2056
2057 /* only root can play with this */
2058 if (!capable(CAP_SYS_ADMIN))
2059 return -EACCES;
2060
2061 if (_IOC_TYPE(command) != DM_IOCTL)
2062 return -ENOTTY;
2063
2064 cmd = _IOC_NR(command);
2065
2066 /*
2067 * Check the interface version passed in. This also
2068 * writes out the kernel's interface version.
2069 */
2070 r = check_version(cmd, user, ¶m_kernel);
2071 if (r)
2072 return r;
2073
2074 /*
2075 * Nothing more to do for the version command.
2076 */
2077 if (cmd == DM_VERSION_CMD)
2078 return 0;
2079
2080 fn = lookup_ioctl(cmd, &ioctl_flags);
2081 if (!fn) {
2082 DMERR("dm_ctl_ioctl: unknown command 0x%x", command);
2083 return -ENOTTY;
2084 }
2085
2086 /*
2087 * Copy the parameters into kernel space.
2088 */
2089 r = copy_params(user, ¶m_kernel, ioctl_flags, ¶m, ¶m_flags);
2090
2091 if (r)
2092 return r;
2093
2094 input_param_size = param->data_size;
2095 r = validate_params(cmd, param);
2096 if (r)
2097 goto out;
2098
2099 param->data_size = offsetof(struct dm_ioctl, data);
2100 r = fn(file, param, input_param_size);
2101
2102 if (unlikely(param->flags & DM_BUFFER_FULL_FLAG) &&
2103 unlikely(ioctl_flags & IOCTL_FLAGS_NO_PARAMS))
2104 DMERR("ioctl %d tried to output some data but has IOCTL_FLAGS_NO_PARAMS set", cmd);
2105
2106 if (!r && ioctl_flags & IOCTL_FLAGS_ISSUE_GLOBAL_EVENT)
2107 dm_issue_global_event();
2108
2109 /*
2110 * Copy the results back to userland.
2111 */
2112 if (!r && copy_to_user(user, param, param->data_size))
2113 r = -EFAULT;
2114
2115out:
2116 free_params(param, input_param_size, param_flags);
2117 return r;
2118}
2119
2120static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
2121{
2122 return (long)ctl_ioctl(file, command, (struct dm_ioctl __user *)u);
2123}
2124
2125#ifdef CONFIG_COMPAT
2126static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
2127{
2128 return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
2129}
2130#else
2131#define dm_compat_ctl_ioctl NULL
2132#endif
2133
2134static int dm_open(struct inode *inode, struct file *filp)
2135{
2136 int r;
2137 struct dm_file *priv;
2138
2139 r = nonseekable_open(inode, filp);
2140 if (unlikely(r))
2141 return r;
2142
2143 priv = filp->private_data = kmalloc(sizeof(struct dm_file), GFP_KERNEL);
2144 if (!priv)
2145 return -ENOMEM;
2146
2147 priv->global_event_nr = atomic_read(&dm_global_event_nr);
2148
2149 return 0;
2150}
2151
2152static int dm_release(struct inode *inode, struct file *filp)
2153{
2154 kfree(filp->private_data);
2155 return 0;
2156}
2157
2158static __poll_t dm_poll(struct file *filp, poll_table *wait)
2159{
2160 struct dm_file *priv = filp->private_data;
2161 __poll_t mask = 0;
2162
2163 poll_wait(filp, &dm_global_eventq, wait);
2164
2165 if ((int)(atomic_read(&dm_global_event_nr) - priv->global_event_nr) > 0)
2166 mask |= EPOLLIN;
2167
2168 return mask;
2169}
2170
2171static const struct file_operations _ctl_fops = {
2172 .open = dm_open,
2173 .release = dm_release,
2174 .poll = dm_poll,
2175 .unlocked_ioctl = dm_ctl_ioctl,
2176 .compat_ioctl = dm_compat_ctl_ioctl,
2177 .owner = THIS_MODULE,
2178 .llseek = noop_llseek,
2179};
2180
2181static struct miscdevice _dm_misc = {
2182 .minor = MAPPER_CTRL_MINOR,
2183 .name = DM_NAME,
2184 .nodename = DM_DIR "/" DM_CONTROL_NODE,
2185 .fops = &_ctl_fops
2186};
2187
2188MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
2189MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
2190
2191/*
2192 * Create misc character device and link to DM_DIR/control.
2193 */
2194int __init dm_interface_init(void)
2195{
2196 int r;
2197
2198 r = misc_register(&_dm_misc);
2199 if (r) {
2200 DMERR("misc_register failed for control device");
2201 return r;
2202 }
2203
2204 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
2205 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
2206 DM_DRIVER_EMAIL);
2207 return 0;
2208}
2209
2210void dm_interface_exit(void)
2211{
2212 misc_deregister(&_dm_misc);
2213 dm_hash_exit();
2214}
2215
2216/**
2217 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
2218 * @md: Pointer to mapped_device
2219 * @name: Buffer (size DM_NAME_LEN) for name
2220 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
2221 */
2222int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
2223{
2224 int r = 0;
2225 struct hash_cell *hc;
2226
2227 if (!md)
2228 return -ENXIO;
2229
2230 mutex_lock(&dm_hash_cells_mutex);
2231 hc = dm_get_mdptr(md);
2232 if (!hc) {
2233 r = -ENXIO;
2234 goto out;
2235 }
2236
2237 if (name)
2238 strcpy(name, hc->name);
2239 if (uuid)
2240 strcpy(uuid, hc->uuid ? : "");
2241
2242out:
2243 mutex_unlock(&dm_hash_cells_mutex);
2244
2245 return r;
2246}
2247EXPORT_SYMBOL_GPL(dm_copy_name_and_uuid);
2248
2249/**
2250 * dm_early_create - create a mapped device in early boot.
2251 *
2252 * @dmi: Contains main information of the device mapping to be created.
2253 * @spec_array: array of pointers to struct dm_target_spec. Describes the
2254 * mapping table of the device.
2255 * @target_params_array: array of strings with the parameters to a specific
2256 * target.
2257 *
2258 * Instead of having the struct dm_target_spec and the parameters for every
2259 * target embedded at the end of struct dm_ioctl (as performed in a normal
2260 * ioctl), pass them as arguments, so the caller doesn't need to serialize them.
2261 * The size of the spec_array and target_params_array is given by
2262 * @dmi->target_count.
2263 * This function is supposed to be called in early boot, so locking mechanisms
2264 * to protect against concurrent loads are not required.
2265 */
2266int __init dm_early_create(struct dm_ioctl *dmi,
2267 struct dm_target_spec **spec_array,
2268 char **target_params_array)
2269{
2270 int r, m = DM_ANY_MINOR;
2271 struct dm_table *t, *old_map;
2272 struct mapped_device *md;
2273 unsigned int i;
2274
2275 if (!dmi->target_count)
2276 return -EINVAL;
2277
2278 r = check_name(dmi->name);
2279 if (r)
2280 return r;
2281
2282 if (dmi->flags & DM_PERSISTENT_DEV_FLAG)
2283 m = MINOR(huge_decode_dev(dmi->dev));
2284
2285 /* alloc dm device */
2286 r = dm_create(m, &md);
2287 if (r)
2288 return r;
2289
2290 /* hash insert */
2291 r = dm_hash_insert(dmi->name, *dmi->uuid ? dmi->uuid : NULL, md);
2292 if (r)
2293 goto err_destroy_dm;
2294
2295 /* alloc table */
2296 r = dm_table_create(&t, get_mode(dmi), dmi->target_count, md);
2297 if (r)
2298 goto err_hash_remove;
2299
2300 /* add targets */
2301 for (i = 0; i < dmi->target_count; i++) {
2302 r = dm_table_add_target(t, spec_array[i]->target_type,
2303 (sector_t) spec_array[i]->sector_start,
2304 (sector_t) spec_array[i]->length,
2305 target_params_array[i]);
2306 if (r) {
2307 DMERR("error adding target to table");
2308 goto err_destroy_table;
2309 }
2310 }
2311
2312 /* finish table */
2313 r = dm_table_complete(t);
2314 if (r)
2315 goto err_destroy_table;
2316
2317 /* setup md->queue to reflect md's type (may block) */
2318 r = dm_setup_md_queue(md, t);
2319 if (r) {
2320 DMERR("unable to set up device queue for new table.");
2321 goto err_destroy_table;
2322 }
2323
2324 /* Set new map */
2325 dm_suspend(md, 0);
2326 old_map = dm_swap_table(md, t);
2327 if (IS_ERR(old_map)) {
2328 r = PTR_ERR(old_map);
2329 goto err_destroy_table;
2330 }
2331 set_disk_ro(dm_disk(md), !!(dmi->flags & DM_READONLY_FLAG));
2332
2333 /* resume device */
2334 r = dm_resume(md);
2335 if (r)
2336 goto err_destroy_table;
2337
2338 DMINFO("%s (%s) is ready", md->disk->disk_name, dmi->name);
2339 dm_put(md);
2340 return 0;
2341
2342err_destroy_table:
2343 dm_table_destroy(t);
2344err_hash_remove:
2345 down_write(&_hash_lock);
2346 (void) __hash_remove(__get_name_cell(dmi->name));
2347 up_write(&_hash_lock);
2348 /* release reference from __get_name_cell */
2349 dm_put(md);
2350err_destroy_dm:
2351 dm_put(md);
2352 dm_destroy(md);
2353 return r;
2354}