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