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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/dm-ioctl.h>
18#include <linux/hdreg.h>
19#include <linux/compat.h>
20
21#include <linux/uaccess.h>
22
23#define DM_MSG_PREFIX "ioctl"
24#define DM_DRIVER_EMAIL "dm-devel@redhat.com"
25
26struct dm_file {
27 /*
28 * poll will wait until the global event number is greater than
29 * this value.
30 */
31 volatile unsigned global_event_nr;
32};
33
34/*-----------------------------------------------------------------
35 * The ioctl interface needs to be able to look up devices by
36 * name or uuid.
37 *---------------------------------------------------------------*/
38struct hash_cell {
39 struct list_head name_list;
40 struct list_head uuid_list;
41
42 char *name;
43 char *uuid;
44 struct mapped_device *md;
45 struct dm_table *new_map;
46};
47
48struct vers_iter {
49 size_t param_size;
50 struct dm_target_versions *vers, *old_vers;
51 char *end;
52 uint32_t flags;
53};
54
55
56#define NUM_BUCKETS 64
57#define MASK_BUCKETS (NUM_BUCKETS - 1)
58static struct list_head _name_buckets[NUM_BUCKETS];
59static struct list_head _uuid_buckets[NUM_BUCKETS];
60
61static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred);
62
63/*
64 * Guards access to both hash tables.
65 */
66static DECLARE_RWSEM(_hash_lock);
67
68/*
69 * Protects use of mdptr to obtain hash cell name and uuid from mapped device.
70 */
71static DEFINE_MUTEX(dm_hash_cells_mutex);
72
73static void init_buckets(struct list_head *buckets)
74{
75 unsigned int i;
76
77 for (i = 0; i < NUM_BUCKETS; i++)
78 INIT_LIST_HEAD(buckets + i);
79}
80
81static int dm_hash_init(void)
82{
83 init_buckets(_name_buckets);
84 init_buckets(_uuid_buckets);
85 return 0;
86}
87
88static void dm_hash_exit(void)
89{
90 dm_hash_remove_all(false, false, false);
91}
92
93/*-----------------------------------------------------------------
94 * Hash function:
95 * We're not really concerned with the str hash function being
96 * fast since it's only used by the ioctl interface.
97 *---------------------------------------------------------------*/
98static unsigned int hash_str(const char *str)
99{
100 const unsigned int hash_mult = 2654435387U;
101 unsigned int h = 0;
102
103 while (*str)
104 h = (h + (unsigned int) *str++) * hash_mult;
105
106 return h & MASK_BUCKETS;
107}
108
109/*-----------------------------------------------------------------
110 * Code for looking up a device by name
111 *---------------------------------------------------------------*/
112static struct hash_cell *__get_name_cell(const char *str)
113{
114 struct hash_cell *hc;
115 unsigned int h = hash_str(str);
116
117 list_for_each_entry (hc, _name_buckets + h, name_list)
118 if (!strcmp(hc->name, str)) {
119 dm_get(hc->md);
120 return hc;
121 }
122
123 return NULL;
124}
125
126static struct hash_cell *__get_uuid_cell(const char *str)
127{
128 struct hash_cell *hc;
129 unsigned int h = hash_str(str);
130
131 list_for_each_entry (hc, _uuid_buckets + h, uuid_list)
132 if (!strcmp(hc->uuid, str)) {
133 dm_get(hc->md);
134 return hc;
135 }
136
137 return NULL;
138}
139
140static struct hash_cell *__get_dev_cell(uint64_t dev)
141{
142 struct mapped_device *md;
143 struct hash_cell *hc;
144
145 md = dm_get_md(huge_decode_dev(dev));
146 if (!md)
147 return NULL;
148
149 hc = dm_get_mdptr(md);
150 if (!hc) {
151 dm_put(md);
152 return NULL;
153 }
154
155 return hc;
156}
157
158/*-----------------------------------------------------------------
159 * Inserting, removing and renaming a device.
160 *---------------------------------------------------------------*/
161static struct hash_cell *alloc_cell(const char *name, const char *uuid,
162 struct mapped_device *md)
163{
164 struct hash_cell *hc;
165
166 hc = kmalloc(sizeof(*hc), GFP_KERNEL);
167 if (!hc)
168 return NULL;
169
170 hc->name = kstrdup(name, GFP_KERNEL);
171 if (!hc->name) {
172 kfree(hc);
173 return NULL;
174 }
175
176 if (!uuid)
177 hc->uuid = NULL;
178
179 else {
180 hc->uuid = kstrdup(uuid, GFP_KERNEL);
181 if (!hc->uuid) {
182 kfree(hc->name);
183 kfree(hc);
184 return NULL;
185 }
186 }
187
188 INIT_LIST_HEAD(&hc->name_list);
189 INIT_LIST_HEAD(&hc->uuid_list);
190 hc->md = md;
191 hc->new_map = NULL;
192 return hc;
193}
194
195static void free_cell(struct hash_cell *hc)
196{
197 if (hc) {
198 kfree(hc->name);
199 kfree(hc->uuid);
200 kfree(hc);
201 }
202}
203
204/*
205 * The kdev_t and uuid of a device can never change once it is
206 * initially inserted.
207 */
208static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
209{
210 struct hash_cell *cell, *hc;
211
212 /*
213 * Allocate the new cells.
214 */
215 cell = alloc_cell(name, uuid, md);
216 if (!cell)
217 return -ENOMEM;
218
219 /*
220 * Insert the cell into both hash tables.
221 */
222 down_write(&_hash_lock);
223 hc = __get_name_cell(name);
224 if (hc) {
225 dm_put(hc->md);
226 goto bad;
227 }
228
229 list_add(&cell->name_list, _name_buckets + hash_str(name));
230
231 if (uuid) {
232 hc = __get_uuid_cell(uuid);
233 if (hc) {
234 list_del(&cell->name_list);
235 dm_put(hc->md);
236 goto bad;
237 }
238 list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
239 }
240 dm_get(md);
241 mutex_lock(&dm_hash_cells_mutex);
242 dm_set_mdptr(md, cell);
243 mutex_unlock(&dm_hash_cells_mutex);
244 up_write(&_hash_lock);
245
246 return 0;
247
248 bad:
249 up_write(&_hash_lock);
250 free_cell(cell);
251 return -EBUSY;
252}
253
254static struct dm_table *__hash_remove(struct hash_cell *hc)
255{
256 struct dm_table *table;
257 int srcu_idx;
258
259 /* remove from the dev hash */
260 list_del(&hc->uuid_list);
261 list_del(&hc->name_list);
262 mutex_lock(&dm_hash_cells_mutex);
263 dm_set_mdptr(hc->md, NULL);
264 mutex_unlock(&dm_hash_cells_mutex);
265
266 table = dm_get_live_table(hc->md, &srcu_idx);
267 if (table)
268 dm_table_event(table);
269 dm_put_live_table(hc->md, srcu_idx);
270
271 table = NULL;
272 if (hc->new_map)
273 table = hc->new_map;
274 dm_put(hc->md);
275 free_cell(hc);
276
277 return table;
278}
279
280static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred)
281{
282 int i, dev_skipped;
283 struct hash_cell *hc;
284 struct mapped_device *md;
285 struct dm_table *t;
286
287retry:
288 dev_skipped = 0;
289
290 down_write(&_hash_lock);
291
292 for (i = 0; i < NUM_BUCKETS; i++) {
293 list_for_each_entry(hc, _name_buckets + i, name_list) {
294 md = hc->md;
295 dm_get(md);
296
297 if (keep_open_devices &&
298 dm_lock_for_deletion(md, mark_deferred, only_deferred)) {
299 dm_put(md);
300 dev_skipped++;
301 continue;
302 }
303
304 t = __hash_remove(hc);
305
306 up_write(&_hash_lock);
307
308 if (t) {
309 dm_sync_table(md);
310 dm_table_destroy(t);
311 }
312 dm_put(md);
313 if (likely(keep_open_devices))
314 dm_destroy(md);
315 else
316 dm_destroy_immediate(md);
317
318 /*
319 * Some mapped devices may be using other mapped
320 * devices, so repeat until we make no further
321 * progress. If a new mapped device is created
322 * here it will also get removed.
323 */
324 goto retry;
325 }
326 }
327
328 up_write(&_hash_lock);
329
330 if (dev_skipped)
331 DMWARN("remove_all left %d open device(s)", dev_skipped);
332}
333
334/*
335 * Set the uuid of a hash_cell that isn't already set.
336 */
337static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
338{
339 mutex_lock(&dm_hash_cells_mutex);
340 hc->uuid = new_uuid;
341 mutex_unlock(&dm_hash_cells_mutex);
342
343 list_add(&hc->uuid_list, _uuid_buckets + hash_str(new_uuid));
344}
345
346/*
347 * Changes the name of a hash_cell and returns the old name for
348 * the caller to free.
349 */
350static char *__change_cell_name(struct hash_cell *hc, char *new_name)
351{
352 char *old_name;
353
354 /*
355 * Rename and move the name cell.
356 */
357 list_del(&hc->name_list);
358 old_name = hc->name;
359
360 mutex_lock(&dm_hash_cells_mutex);
361 hc->name = new_name;
362 mutex_unlock(&dm_hash_cells_mutex);
363
364 list_add(&hc->name_list, _name_buckets + hash_str(new_name));
365
366 return old_name;
367}
368
369static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
370 const char *new)
371{
372 char *new_data, *old_name = NULL;
373 struct hash_cell *hc;
374 struct dm_table *table;
375 struct mapped_device *md;
376 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
377 int srcu_idx;
378
379 /*
380 * duplicate new.
381 */
382 new_data = kstrdup(new, GFP_KERNEL);
383 if (!new_data)
384 return ERR_PTR(-ENOMEM);
385
386 down_write(&_hash_lock);
387
388 /*
389 * Is new free ?
390 */
391 if (change_uuid)
392 hc = __get_uuid_cell(new);
393 else
394 hc = __get_name_cell(new);
395
396 if (hc) {
397 DMWARN("Unable to change %s on mapped device %s to one that "
398 "already exists: %s",
399 change_uuid ? "uuid" : "name",
400 param->name, new);
401 dm_put(hc->md);
402 up_write(&_hash_lock);
403 kfree(new_data);
404 return ERR_PTR(-EBUSY);
405 }
406
407 /*
408 * Is there such a device as 'old' ?
409 */
410 hc = __get_name_cell(param->name);
411 if (!hc) {
412 DMWARN("Unable to rename non-existent device, %s to %s%s",
413 param->name, change_uuid ? "uuid " : "", new);
414 up_write(&_hash_lock);
415 kfree(new_data);
416 return ERR_PTR(-ENXIO);
417 }
418
419 /*
420 * Does this device already have a uuid?
421 */
422 if (change_uuid && hc->uuid) {
423 DMWARN("Unable to change uuid of mapped device %s to %s "
424 "because uuid is already set to %s",
425 param->name, new, hc->uuid);
426 dm_put(hc->md);
427 up_write(&_hash_lock);
428 kfree(new_data);
429 return ERR_PTR(-EINVAL);
430 }
431
432 if (change_uuid)
433 __set_cell_uuid(hc, new_data);
434 else
435 old_name = __change_cell_name(hc, new_data);
436
437 /*
438 * Wake up any dm event waiters.
439 */
440 table = dm_get_live_table(hc->md, &srcu_idx);
441 if (table)
442 dm_table_event(table);
443 dm_put_live_table(hc->md, srcu_idx);
444
445 if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr))
446 param->flags |= DM_UEVENT_GENERATED_FLAG;
447
448 md = hc->md;
449 up_write(&_hash_lock);
450 kfree(old_name);
451
452 return md;
453}
454
455void dm_deferred_remove(void)
456{
457 dm_hash_remove_all(true, false, true);
458}
459
460/*-----------------------------------------------------------------
461 * Implementation of the ioctl commands
462 *---------------------------------------------------------------*/
463/*
464 * All the ioctl commands get dispatched to functions with this
465 * prototype.
466 */
467typedef int (*ioctl_fn)(struct file *filp, struct dm_ioctl *param, size_t param_size);
468
469static int remove_all(struct file *filp, struct dm_ioctl *param, size_t param_size)
470{
471 dm_hash_remove_all(true, !!(param->flags & DM_DEFERRED_REMOVE), false);
472 param->data_size = 0;
473 return 0;
474}
475
476/*
477 * Round up the ptr to an 8-byte boundary.
478 */
479#define ALIGN_MASK 7
480static inline size_t align_val(size_t val)
481{
482 return (val + ALIGN_MASK) & ~ALIGN_MASK;
483}
484static inline void *align_ptr(void *ptr)
485{
486 return (void *)align_val((size_t)ptr);
487}
488
489/*
490 * Retrieves the data payload buffer from an already allocated
491 * struct dm_ioctl.
492 */
493static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
494 size_t *len)
495{
496 param->data_start = align_ptr(param + 1) - (void *) param;
497
498 if (param->data_start < param_size)
499 *len = param_size - param->data_start;
500 else
501 *len = 0;
502
503 return ((void *) param) + param->data_start;
504}
505
506static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_size)
507{
508 unsigned int i;
509 struct hash_cell *hc;
510 size_t len, needed = 0;
511 struct gendisk *disk;
512 struct dm_name_list *orig_nl, *nl, *old_nl = NULL;
513 uint32_t *event_nr;
514
515 down_write(&_hash_lock);
516
517 /*
518 * Loop through all the devices working out how much
519 * space we need.
520 */
521 for (i = 0; i < NUM_BUCKETS; i++) {
522 list_for_each_entry (hc, _name_buckets + i, name_list) {
523 needed += align_val(offsetof(struct dm_name_list, name) + strlen(hc->name) + 1);
524 needed += align_val(sizeof(uint32_t));
525 }
526 }
527
528 /*
529 * Grab our output buffer.
530 */
531 nl = orig_nl = get_result_buffer(param, param_size, &len);
532 if (len < needed) {
533 param->flags |= DM_BUFFER_FULL_FLAG;
534 goto out;
535 }
536 param->data_size = param->data_start + needed;
537
538 nl->dev = 0; /* Flags no data */
539
540 /*
541 * Now loop through filling out the names.
542 */
543 for (i = 0; i < NUM_BUCKETS; i++) {
544 list_for_each_entry (hc, _name_buckets + i, name_list) {
545 if (old_nl)
546 old_nl->next = (uint32_t) ((void *) nl -
547 (void *) old_nl);
548 disk = dm_disk(hc->md);
549 nl->dev = huge_encode_dev(disk_devt(disk));
550 nl->next = 0;
551 strcpy(nl->name, hc->name);
552
553 old_nl = nl;
554 event_nr = align_ptr(nl->name + strlen(hc->name) + 1);
555 *event_nr = dm_get_event_nr(hc->md);
556 nl = align_ptr(event_nr + 1);
557 }
558 }
559 /*
560 * If mismatch happens, security may be compromised due to buffer
561 * overflow, so it's better to crash.
562 */
563 BUG_ON((char *)nl - (char *)orig_nl != needed);
564
565 out:
566 up_write(&_hash_lock);
567 return 0;
568}
569
570static void list_version_get_needed(struct target_type *tt, void *needed_param)
571{
572 size_t *needed = needed_param;
573
574 *needed += sizeof(struct dm_target_versions);
575 *needed += strlen(tt->name);
576 *needed += ALIGN_MASK;
577}
578
579static void list_version_get_info(struct target_type *tt, void *param)
580{
581 struct vers_iter *info = param;
582
583 /* Check space - it might have changed since the first iteration */
584 if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
585 info->end) {
586
587 info->flags = DM_BUFFER_FULL_FLAG;
588 return;
589 }
590
591 if (info->old_vers)
592 info->old_vers->next = (uint32_t) ((void *)info->vers -
593 (void *)info->old_vers);
594 info->vers->version[0] = tt->version[0];
595 info->vers->version[1] = tt->version[1];
596 info->vers->version[2] = tt->version[2];
597 info->vers->next = 0;
598 strcpy(info->vers->name, tt->name);
599
600 info->old_vers = info->vers;
601 info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
602}
603
604static int list_versions(struct file *filp, struct dm_ioctl *param, size_t param_size)
605{
606 size_t len, needed = 0;
607 struct dm_target_versions *vers;
608 struct vers_iter iter_info;
609
610 /*
611 * Loop through all the devices working out how much
612 * space we need.
613 */
614 dm_target_iterate(list_version_get_needed, &needed);
615
616 /*
617 * Grab our output buffer.
618 */
619 vers = get_result_buffer(param, param_size, &len);
620 if (len < needed) {
621 param->flags |= DM_BUFFER_FULL_FLAG;
622 goto out;
623 }
624 param->data_size = param->data_start + needed;
625
626 iter_info.param_size = param_size;
627 iter_info.old_vers = NULL;
628 iter_info.vers = vers;
629 iter_info.flags = 0;
630 iter_info.end = (char *)vers+len;
631
632 /*
633 * Now loop through filling out the names & versions.
634 */
635 dm_target_iterate(list_version_get_info, &iter_info);
636 param->flags |= iter_info.flags;
637
638 out:
639 return 0;
640}
641
642static int check_name(const char *name)
643{
644 if (strchr(name, '/')) {
645 DMWARN("invalid device name");
646 return -EINVAL;
647 }
648
649 return 0;
650}
651
652/*
653 * On successful return, the caller must not attempt to acquire
654 * _hash_lock without first calling dm_put_live_table, because dm_table_destroy
655 * waits for this dm_put_live_table and could be called under this lock.
656 */
657static struct dm_table *dm_get_inactive_table(struct mapped_device *md, int *srcu_idx)
658{
659 struct hash_cell *hc;
660 struct dm_table *table = NULL;
661
662 /* increment rcu count, we don't care about the table pointer */
663 dm_get_live_table(md, srcu_idx);
664
665 down_read(&_hash_lock);
666 hc = dm_get_mdptr(md);
667 if (!hc || hc->md != md) {
668 DMWARN("device has been removed from the dev hash table.");
669 goto out;
670 }
671
672 table = hc->new_map;
673
674out:
675 up_read(&_hash_lock);
676
677 return table;
678}
679
680static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
681 struct dm_ioctl *param,
682 int *srcu_idx)
683{
684 return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
685 dm_get_inactive_table(md, srcu_idx) : dm_get_live_table(md, srcu_idx);
686}
687
688/*
689 * Fills in a dm_ioctl structure, ready for sending back to
690 * userland.
691 */
692static void __dev_status(struct mapped_device *md, struct dm_ioctl *param)
693{
694 struct gendisk *disk = dm_disk(md);
695 struct dm_table *table;
696 int srcu_idx;
697
698 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
699 DM_ACTIVE_PRESENT_FLAG | DM_INTERNAL_SUSPEND_FLAG);
700
701 if (dm_suspended_md(md))
702 param->flags |= DM_SUSPEND_FLAG;
703
704 if (dm_suspended_internally_md(md))
705 param->flags |= DM_INTERNAL_SUSPEND_FLAG;
706
707 if (dm_test_deferred_remove_flag(md))
708 param->flags |= DM_DEFERRED_REMOVE;
709
710 param->dev = huge_encode_dev(disk_devt(disk));
711
712 /*
713 * Yes, this will be out of date by the time it gets back
714 * to userland, but it is still very useful for
715 * debugging.
716 */
717 param->open_count = dm_open_count(md);
718
719 param->event_nr = dm_get_event_nr(md);
720 param->target_count = 0;
721
722 table = dm_get_live_table(md, &srcu_idx);
723 if (table) {
724 if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
725 if (get_disk_ro(disk))
726 param->flags |= DM_READONLY_FLAG;
727 param->target_count = dm_table_get_num_targets(table);
728 }
729
730 param->flags |= DM_ACTIVE_PRESENT_FLAG;
731 }
732 dm_put_live_table(md, srcu_idx);
733
734 if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
735 int srcu_idx;
736 table = dm_get_inactive_table(md, &srcu_idx);
737 if (table) {
738 if (!(dm_table_get_mode(table) & FMODE_WRITE))
739 param->flags |= DM_READONLY_FLAG;
740 param->target_count = dm_table_get_num_targets(table);
741 }
742 dm_put_live_table(md, srcu_idx);
743 }
744}
745
746static int dev_create(struct file *filp, struct dm_ioctl *param, size_t param_size)
747{
748 int r, m = DM_ANY_MINOR;
749 struct mapped_device *md;
750
751 r = check_name(param->name);
752 if (r)
753 return r;
754
755 if (param->flags & DM_PERSISTENT_DEV_FLAG)
756 m = MINOR(huge_decode_dev(param->dev));
757
758 r = dm_create(m, &md);
759 if (r)
760 return r;
761
762 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
763 if (r) {
764 dm_put(md);
765 dm_destroy(md);
766 return r;
767 }
768
769 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
770
771 __dev_status(md, param);
772
773 dm_put(md);
774
775 return 0;
776}
777
778/*
779 * Always use UUID for lookups if it's present, otherwise use name or dev.
780 */
781static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
782{
783 struct hash_cell *hc = NULL;
784
785 if (*param->uuid) {
786 if (*param->name || param->dev)
787 return NULL;
788
789 hc = __get_uuid_cell(param->uuid);
790 if (!hc)
791 return NULL;
792 } else if (*param->name) {
793 if (param->dev)
794 return NULL;
795
796 hc = __get_name_cell(param->name);
797 if (!hc)
798 return NULL;
799 } else if (param->dev) {
800 hc = __get_dev_cell(param->dev);
801 if (!hc)
802 return NULL;
803 } else
804 return NULL;
805
806 /*
807 * Sneakily write in both the name and the uuid
808 * while we have the cell.
809 */
810 strlcpy(param->name, hc->name, sizeof(param->name));
811 if (hc->uuid)
812 strlcpy(param->uuid, hc->uuid, sizeof(param->uuid));
813 else
814 param->uuid[0] = '\0';
815
816 if (hc->new_map)
817 param->flags |= DM_INACTIVE_PRESENT_FLAG;
818 else
819 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
820
821 return hc;
822}
823
824static struct mapped_device *find_device(struct dm_ioctl *param)
825{
826 struct hash_cell *hc;
827 struct mapped_device *md = NULL;
828
829 down_read(&_hash_lock);
830 hc = __find_device_hash_cell(param);
831 if (hc)
832 md = hc->md;
833 up_read(&_hash_lock);
834
835 return md;
836}
837
838static int dev_remove(struct file *filp, struct dm_ioctl *param, size_t param_size)
839{
840 struct hash_cell *hc;
841 struct mapped_device *md;
842 int r;
843 struct dm_table *t;
844
845 down_write(&_hash_lock);
846 hc = __find_device_hash_cell(param);
847
848 if (!hc) {
849 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
850 up_write(&_hash_lock);
851 return -ENXIO;
852 }
853
854 md = hc->md;
855
856 /*
857 * Ensure the device is not open and nothing further can open it.
858 */
859 r = dm_lock_for_deletion(md, !!(param->flags & DM_DEFERRED_REMOVE), false);
860 if (r) {
861 if (r == -EBUSY && param->flags & DM_DEFERRED_REMOVE) {
862 up_write(&_hash_lock);
863 dm_put(md);
864 return 0;
865 }
866 DMDEBUG_LIMIT("unable to remove open device %s", hc->name);
867 up_write(&_hash_lock);
868 dm_put(md);
869 return r;
870 }
871
872 t = __hash_remove(hc);
873 up_write(&_hash_lock);
874
875 if (t) {
876 dm_sync_table(md);
877 dm_table_destroy(t);
878 }
879
880 param->flags &= ~DM_DEFERRED_REMOVE;
881
882 if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr))
883 param->flags |= DM_UEVENT_GENERATED_FLAG;
884
885 dm_put(md);
886 dm_destroy(md);
887 return 0;
888}
889
890/*
891 * Check a string doesn't overrun the chunk of
892 * memory we copied from userland.
893 */
894static int invalid_str(char *str, void *end)
895{
896 while ((void *) str < end)
897 if (!*str++)
898 return 0;
899
900 return -EINVAL;
901}
902
903static int dev_rename(struct file *filp, struct dm_ioctl *param, size_t param_size)
904{
905 int r;
906 char *new_data = (char *) param + param->data_start;
907 struct mapped_device *md;
908 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
909
910 if (new_data < param->data ||
911 invalid_str(new_data, (void *) param + param_size) || !*new_data ||
912 strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
913 DMWARN("Invalid new mapped device name or uuid string supplied.");
914 return -EINVAL;
915 }
916
917 if (!change_uuid) {
918 r = check_name(new_data);
919 if (r)
920 return r;
921 }
922
923 md = dm_hash_rename(param, new_data);
924 if (IS_ERR(md))
925 return PTR_ERR(md);
926
927 __dev_status(md, param);
928 dm_put(md);
929
930 return 0;
931}
932
933static int dev_set_geometry(struct file *filp, struct dm_ioctl *param, size_t param_size)
934{
935 int r = -EINVAL, x;
936 struct mapped_device *md;
937 struct hd_geometry geometry;
938 unsigned long indata[4];
939 char *geostr = (char *) param + param->data_start;
940 char dummy;
941
942 md = find_device(param);
943 if (!md)
944 return -ENXIO;
945
946 if (geostr < param->data ||
947 invalid_str(geostr, (void *) param + param_size)) {
948 DMWARN("Invalid geometry supplied.");
949 goto out;
950 }
951
952 x = sscanf(geostr, "%lu %lu %lu %lu%c", indata,
953 indata + 1, indata + 2, indata + 3, &dummy);
954
955 if (x != 4) {
956 DMWARN("Unable to interpret geometry settings.");
957 goto out;
958 }
959
960 if (indata[0] > 65535 || indata[1] > 255 ||
961 indata[2] > 255 || indata[3] > ULONG_MAX) {
962 DMWARN("Geometry exceeds range limits.");
963 goto out;
964 }
965
966 geometry.cylinders = indata[0];
967 geometry.heads = indata[1];
968 geometry.sectors = indata[2];
969 geometry.start = indata[3];
970
971 r = dm_set_geometry(md, &geometry);
972
973 param->data_size = 0;
974
975out:
976 dm_put(md);
977 return r;
978}
979
980static int do_suspend(struct dm_ioctl *param)
981{
982 int r = 0;
983 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
984 struct mapped_device *md;
985
986 md = find_device(param);
987 if (!md)
988 return -ENXIO;
989
990 if (param->flags & DM_SKIP_LOCKFS_FLAG)
991 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
992 if (param->flags & DM_NOFLUSH_FLAG)
993 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
994
995 if (!dm_suspended_md(md)) {
996 r = dm_suspend(md, suspend_flags);
997 if (r)
998 goto out;
999 }
1000
1001 __dev_status(md, param);
1002
1003out:
1004 dm_put(md);
1005
1006 return r;
1007}
1008
1009static int do_resume(struct dm_ioctl *param)
1010{
1011 int r = 0;
1012 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
1013 struct hash_cell *hc;
1014 struct mapped_device *md;
1015 struct dm_table *new_map, *old_map = NULL;
1016
1017 down_write(&_hash_lock);
1018
1019 hc = __find_device_hash_cell(param);
1020 if (!hc) {
1021 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1022 up_write(&_hash_lock);
1023 return -ENXIO;
1024 }
1025
1026 md = hc->md;
1027
1028 new_map = hc->new_map;
1029 hc->new_map = NULL;
1030 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1031
1032 up_write(&_hash_lock);
1033
1034 /* Do we need to load a new map ? */
1035 if (new_map) {
1036 /* Suspend if it isn't already suspended */
1037 if (param->flags & DM_SKIP_LOCKFS_FLAG)
1038 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
1039 if (param->flags & DM_NOFLUSH_FLAG)
1040 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
1041 if (!dm_suspended_md(md))
1042 dm_suspend(md, suspend_flags);
1043
1044 old_map = dm_swap_table(md, new_map);
1045 if (IS_ERR(old_map)) {
1046 dm_sync_table(md);
1047 dm_table_destroy(new_map);
1048 dm_put(md);
1049 return PTR_ERR(old_map);
1050 }
1051
1052 if (dm_table_get_mode(new_map) & FMODE_WRITE)
1053 set_disk_ro(dm_disk(md), 0);
1054 else
1055 set_disk_ro(dm_disk(md), 1);
1056 }
1057
1058 if (dm_suspended_md(md)) {
1059 r = dm_resume(md);
1060 if (!r && !dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr))
1061 param->flags |= DM_UEVENT_GENERATED_FLAG;
1062 }
1063
1064 /*
1065 * Since dm_swap_table synchronizes RCU, nobody should be in
1066 * read-side critical section already.
1067 */
1068 if (old_map)
1069 dm_table_destroy(old_map);
1070
1071 if (!r)
1072 __dev_status(md, param);
1073
1074 dm_put(md);
1075 return r;
1076}
1077
1078/*
1079 * Set or unset the suspension state of a device.
1080 * If the device already is in the requested state we just return its status.
1081 */
1082static int dev_suspend(struct file *filp, struct dm_ioctl *param, size_t param_size)
1083{
1084 if (param->flags & DM_SUSPEND_FLAG)
1085 return do_suspend(param);
1086
1087 return do_resume(param);
1088}
1089
1090/*
1091 * Copies device info back to user space, used by
1092 * the create and info ioctls.
1093 */
1094static int dev_status(struct file *filp, struct dm_ioctl *param, size_t param_size)
1095{
1096 struct mapped_device *md;
1097
1098 md = find_device(param);
1099 if (!md)
1100 return -ENXIO;
1101
1102 __dev_status(md, param);
1103 dm_put(md);
1104
1105 return 0;
1106}
1107
1108/*
1109 * Build up the status struct for each target
1110 */
1111static void retrieve_status(struct dm_table *table,
1112 struct dm_ioctl *param, size_t param_size)
1113{
1114 unsigned int i, num_targets;
1115 struct dm_target_spec *spec;
1116 char *outbuf, *outptr;
1117 status_type_t type;
1118 size_t remaining, len, used = 0;
1119 unsigned status_flags = 0;
1120
1121 outptr = outbuf = get_result_buffer(param, param_size, &len);
1122
1123 if (param->flags & DM_STATUS_TABLE_FLAG)
1124 type = STATUSTYPE_TABLE;
1125 else
1126 type = STATUSTYPE_INFO;
1127
1128 /* Get all the target info */
1129 num_targets = dm_table_get_num_targets(table);
1130 for (i = 0; i < num_targets; i++) {
1131 struct dm_target *ti = dm_table_get_target(table, i);
1132 size_t l;
1133
1134 remaining = len - (outptr - outbuf);
1135 if (remaining <= sizeof(struct dm_target_spec)) {
1136 param->flags |= DM_BUFFER_FULL_FLAG;
1137 break;
1138 }
1139
1140 spec = (struct dm_target_spec *) outptr;
1141
1142 spec->status = 0;
1143 spec->sector_start = ti->begin;
1144 spec->length = ti->len;
1145 strncpy(spec->target_type, ti->type->name,
1146 sizeof(spec->target_type));
1147
1148 outptr += sizeof(struct dm_target_spec);
1149 remaining = len - (outptr - outbuf);
1150 if (remaining <= 0) {
1151 param->flags |= DM_BUFFER_FULL_FLAG;
1152 break;
1153 }
1154
1155 /* Get the status/table string from the target driver */
1156 if (ti->type->status) {
1157 if (param->flags & DM_NOFLUSH_FLAG)
1158 status_flags |= DM_STATUS_NOFLUSH_FLAG;
1159 ti->type->status(ti, type, status_flags, outptr, remaining);
1160 } else
1161 outptr[0] = '\0';
1162
1163 l = strlen(outptr) + 1;
1164 if (l == remaining) {
1165 param->flags |= DM_BUFFER_FULL_FLAG;
1166 break;
1167 }
1168
1169 outptr += l;
1170 used = param->data_start + (outptr - outbuf);
1171
1172 outptr = align_ptr(outptr);
1173 spec->next = outptr - outbuf;
1174 }
1175
1176 if (used)
1177 param->data_size = used;
1178
1179 param->target_count = num_targets;
1180}
1181
1182/*
1183 * Wait for a device to report an event
1184 */
1185static int dev_wait(struct file *filp, struct dm_ioctl *param, size_t param_size)
1186{
1187 int r = 0;
1188 struct mapped_device *md;
1189 struct dm_table *table;
1190 int srcu_idx;
1191
1192 md = find_device(param);
1193 if (!md)
1194 return -ENXIO;
1195
1196 /*
1197 * Wait for a notification event
1198 */
1199 if (dm_wait_event(md, param->event_nr)) {
1200 r = -ERESTARTSYS;
1201 goto out;
1202 }
1203
1204 /*
1205 * The userland program is going to want to know what
1206 * changed to trigger the event, so we may as well tell
1207 * him and save an ioctl.
1208 */
1209 __dev_status(md, param);
1210
1211 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1212 if (table)
1213 retrieve_status(table, param, param_size);
1214 dm_put_live_table(md, srcu_idx);
1215
1216out:
1217 dm_put(md);
1218
1219 return r;
1220}
1221
1222/*
1223 * Remember the global event number and make it possible to poll
1224 * for further events.
1225 */
1226static int dev_arm_poll(struct file *filp, struct dm_ioctl *param, size_t param_size)
1227{
1228 struct dm_file *priv = filp->private_data;
1229
1230 priv->global_event_nr = atomic_read(&dm_global_event_nr);
1231
1232 return 0;
1233}
1234
1235static inline fmode_t get_mode(struct dm_ioctl *param)
1236{
1237 fmode_t mode = FMODE_READ | FMODE_WRITE;
1238
1239 if (param->flags & DM_READONLY_FLAG)
1240 mode = FMODE_READ;
1241
1242 return mode;
1243}
1244
1245static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
1246 struct dm_target_spec **spec, char **target_params)
1247{
1248 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1249 *target_params = (char *) (*spec + 1);
1250
1251 if (*spec < (last + 1))
1252 return -EINVAL;
1253
1254 return invalid_str(*target_params, end);
1255}
1256
1257static int populate_table(struct dm_table *table,
1258 struct dm_ioctl *param, size_t param_size)
1259{
1260 int r;
1261 unsigned int i = 0;
1262 struct dm_target_spec *spec = (struct dm_target_spec *) param;
1263 uint32_t next = param->data_start;
1264 void *end = (void *) param + param_size;
1265 char *target_params;
1266
1267 if (!param->target_count) {
1268 DMWARN("populate_table: no targets specified");
1269 return -EINVAL;
1270 }
1271
1272 for (i = 0; i < param->target_count; i++) {
1273
1274 r = next_target(spec, next, end, &spec, &target_params);
1275 if (r) {
1276 DMWARN("unable to find target");
1277 return r;
1278 }
1279
1280 r = dm_table_add_target(table, spec->target_type,
1281 (sector_t) spec->sector_start,
1282 (sector_t) spec->length,
1283 target_params);
1284 if (r) {
1285 DMWARN("error adding target to table");
1286 return r;
1287 }
1288
1289 next = spec->next;
1290 }
1291
1292 return dm_table_complete(table);
1293}
1294
1295static bool is_valid_type(enum dm_queue_mode cur, enum dm_queue_mode new)
1296{
1297 if (cur == new ||
1298 (cur == DM_TYPE_BIO_BASED && new == DM_TYPE_DAX_BIO_BASED))
1299 return true;
1300
1301 return false;
1302}
1303
1304static int table_load(struct file *filp, struct dm_ioctl *param, size_t param_size)
1305{
1306 int r;
1307 struct hash_cell *hc;
1308 struct dm_table *t, *old_map = NULL;
1309 struct mapped_device *md;
1310 struct target_type *immutable_target_type;
1311
1312 md = find_device(param);
1313 if (!md)
1314 return -ENXIO;
1315
1316 r = dm_table_create(&t, get_mode(param), param->target_count, md);
1317 if (r)
1318 goto err;
1319
1320 /* Protect md->type and md->queue against concurrent table loads. */
1321 dm_lock_md_type(md);
1322 r = populate_table(t, param, param_size);
1323 if (r)
1324 goto err_unlock_md_type;
1325
1326 immutable_target_type = dm_get_immutable_target_type(md);
1327 if (immutable_target_type &&
1328 (immutable_target_type != dm_table_get_immutable_target_type(t)) &&
1329 !dm_table_get_wildcard_target(t)) {
1330 DMWARN("can't replace immutable target type %s",
1331 immutable_target_type->name);
1332 r = -EINVAL;
1333 goto err_unlock_md_type;
1334 }
1335
1336 if (dm_get_md_type(md) == DM_TYPE_NONE) {
1337 /* Initial table load: acquire type of table. */
1338 dm_set_md_type(md, dm_table_get_type(t));
1339
1340 /* setup md->queue to reflect md's type (may block) */
1341 r = dm_setup_md_queue(md, t);
1342 if (r) {
1343 DMWARN("unable to set up device queue for new table.");
1344 goto err_unlock_md_type;
1345 }
1346 } else if (!is_valid_type(dm_get_md_type(md), dm_table_get_type(t))) {
1347 DMWARN("can't change device type after initial table load.");
1348 r = -EINVAL;
1349 goto err_unlock_md_type;
1350 }
1351
1352 dm_unlock_md_type(md);
1353
1354 /* stage inactive table */
1355 down_write(&_hash_lock);
1356 hc = dm_get_mdptr(md);
1357 if (!hc || hc->md != md) {
1358 DMWARN("device has been removed from the dev hash table.");
1359 up_write(&_hash_lock);
1360 r = -ENXIO;
1361 goto err_destroy_table;
1362 }
1363
1364 if (hc->new_map)
1365 old_map = hc->new_map;
1366 hc->new_map = t;
1367 up_write(&_hash_lock);
1368
1369 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1370 __dev_status(md, param);
1371
1372 if (old_map) {
1373 dm_sync_table(md);
1374 dm_table_destroy(old_map);
1375 }
1376
1377 dm_put(md);
1378
1379 return 0;
1380
1381err_unlock_md_type:
1382 dm_unlock_md_type(md);
1383err_destroy_table:
1384 dm_table_destroy(t);
1385err:
1386 dm_put(md);
1387
1388 return r;
1389}
1390
1391static int table_clear(struct file *filp, struct dm_ioctl *param, size_t param_size)
1392{
1393 struct hash_cell *hc;
1394 struct mapped_device *md;
1395 struct dm_table *old_map = NULL;
1396
1397 down_write(&_hash_lock);
1398
1399 hc = __find_device_hash_cell(param);
1400 if (!hc) {
1401 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1402 up_write(&_hash_lock);
1403 return -ENXIO;
1404 }
1405
1406 if (hc->new_map) {
1407 old_map = hc->new_map;
1408 hc->new_map = NULL;
1409 }
1410
1411 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1412
1413 __dev_status(hc->md, param);
1414 md = hc->md;
1415 up_write(&_hash_lock);
1416 if (old_map) {
1417 dm_sync_table(md);
1418 dm_table_destroy(old_map);
1419 }
1420 dm_put(md);
1421
1422 return 0;
1423}
1424
1425/*
1426 * Retrieves a list of devices used by a particular dm device.
1427 */
1428static void retrieve_deps(struct dm_table *table,
1429 struct dm_ioctl *param, size_t param_size)
1430{
1431 unsigned int count = 0;
1432 struct list_head *tmp;
1433 size_t len, needed;
1434 struct dm_dev_internal *dd;
1435 struct dm_target_deps *deps;
1436
1437 deps = get_result_buffer(param, param_size, &len);
1438
1439 /*
1440 * Count the devices.
1441 */
1442 list_for_each (tmp, dm_table_get_devices(table))
1443 count++;
1444
1445 /*
1446 * Check we have enough space.
1447 */
1448 needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
1449 if (len < needed) {
1450 param->flags |= DM_BUFFER_FULL_FLAG;
1451 return;
1452 }
1453
1454 /*
1455 * Fill in the devices.
1456 */
1457 deps->count = count;
1458 count = 0;
1459 list_for_each_entry (dd, dm_table_get_devices(table), list)
1460 deps->dev[count++] = huge_encode_dev(dd->dm_dev->bdev->bd_dev);
1461
1462 param->data_size = param->data_start + needed;
1463}
1464
1465static int table_deps(struct file *filp, struct dm_ioctl *param, size_t param_size)
1466{
1467 struct mapped_device *md;
1468 struct dm_table *table;
1469 int srcu_idx;
1470
1471 md = find_device(param);
1472 if (!md)
1473 return -ENXIO;
1474
1475 __dev_status(md, param);
1476
1477 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1478 if (table)
1479 retrieve_deps(table, param, param_size);
1480 dm_put_live_table(md, srcu_idx);
1481
1482 dm_put(md);
1483
1484 return 0;
1485}
1486
1487/*
1488 * Return the status of a device as a text string for each
1489 * target.
1490 */
1491static int table_status(struct file *filp, struct dm_ioctl *param, size_t param_size)
1492{
1493 struct mapped_device *md;
1494 struct dm_table *table;
1495 int srcu_idx;
1496
1497 md = find_device(param);
1498 if (!md)
1499 return -ENXIO;
1500
1501 __dev_status(md, param);
1502
1503 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1504 if (table)
1505 retrieve_status(table, param, param_size);
1506 dm_put_live_table(md, srcu_idx);
1507
1508 dm_put(md);
1509
1510 return 0;
1511}
1512
1513/*
1514 * Process device-mapper dependent messages. Messages prefixed with '@'
1515 * are processed by the DM core. All others are delivered to the target.
1516 * Returns a number <= 1 if message was processed by device mapper.
1517 * Returns 2 if message should be delivered to the target.
1518 */
1519static int message_for_md(struct mapped_device *md, unsigned argc, char **argv,
1520 char *result, unsigned maxlen)
1521{
1522 int r;
1523
1524 if (**argv != '@')
1525 return 2; /* no '@' prefix, deliver to target */
1526
1527 if (!strcasecmp(argv[0], "@cancel_deferred_remove")) {
1528 if (argc != 1) {
1529 DMERR("Invalid arguments for @cancel_deferred_remove");
1530 return -EINVAL;
1531 }
1532 return dm_cancel_deferred_remove(md);
1533 }
1534
1535 r = dm_stats_message(md, argc, argv, result, maxlen);
1536 if (r < 2)
1537 return r;
1538
1539 DMERR("Unsupported message sent to DM core: %s", argv[0]);
1540 return -EINVAL;
1541}
1542
1543/*
1544 * Pass a message to the target that's at the supplied device offset.
1545 */
1546static int target_message(struct file *filp, struct dm_ioctl *param, size_t param_size)
1547{
1548 int r, argc;
1549 char **argv;
1550 struct mapped_device *md;
1551 struct dm_table *table;
1552 struct dm_target *ti;
1553 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1554 size_t maxlen;
1555 char *result = get_result_buffer(param, param_size, &maxlen);
1556 int srcu_idx;
1557
1558 md = find_device(param);
1559 if (!md)
1560 return -ENXIO;
1561
1562 if (tmsg < (struct dm_target_msg *) param->data ||
1563 invalid_str(tmsg->message, (void *) param + param_size)) {
1564 DMWARN("Invalid target message parameters.");
1565 r = -EINVAL;
1566 goto out;
1567 }
1568
1569 r = dm_split_args(&argc, &argv, tmsg->message);
1570 if (r) {
1571 DMWARN("Failed to split target message parameters");
1572 goto out;
1573 }
1574
1575 if (!argc) {
1576 DMWARN("Empty message received.");
1577 goto out_argv;
1578 }
1579
1580 r = message_for_md(md, argc, argv, result, maxlen);
1581 if (r <= 1)
1582 goto out_argv;
1583
1584 table = dm_get_live_table(md, &srcu_idx);
1585 if (!table)
1586 goto out_table;
1587
1588 if (dm_deleting_md(md)) {
1589 r = -ENXIO;
1590 goto out_table;
1591 }
1592
1593 ti = dm_table_find_target(table, tmsg->sector);
1594 if (!dm_target_is_valid(ti)) {
1595 DMWARN("Target message sector outside device.");
1596 r = -EINVAL;
1597 } else if (ti->type->message)
1598 r = ti->type->message(ti, argc, argv, result, maxlen);
1599 else {
1600 DMWARN("Target type does not support messages");
1601 r = -EINVAL;
1602 }
1603
1604 out_table:
1605 dm_put_live_table(md, srcu_idx);
1606 out_argv:
1607 kfree(argv);
1608 out:
1609 if (r >= 0)
1610 __dev_status(md, param);
1611
1612 if (r == 1) {
1613 param->flags |= DM_DATA_OUT_FLAG;
1614 if (dm_message_test_buffer_overflow(result, maxlen))
1615 param->flags |= DM_BUFFER_FULL_FLAG;
1616 else
1617 param->data_size = param->data_start + strlen(result) + 1;
1618 r = 0;
1619 }
1620
1621 dm_put(md);
1622 return r;
1623}
1624
1625/*
1626 * The ioctl parameter block consists of two parts, a dm_ioctl struct
1627 * followed by a data buffer. This flag is set if the second part,
1628 * which has a variable size, is not used by the function processing
1629 * the ioctl.
1630 */
1631#define IOCTL_FLAGS_NO_PARAMS 1
1632#define IOCTL_FLAGS_ISSUE_GLOBAL_EVENT 2
1633
1634/*-----------------------------------------------------------------
1635 * Implementation of open/close/ioctl on the special char
1636 * device.
1637 *---------------------------------------------------------------*/
1638static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags)
1639{
1640 static const struct {
1641 int cmd;
1642 int flags;
1643 ioctl_fn fn;
1644 } _ioctls[] = {
1645 {DM_VERSION_CMD, 0, NULL}, /* version is dealt with elsewhere */
1646 {DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, remove_all},
1647 {DM_LIST_DEVICES_CMD, 0, list_devices},
1648
1649 {DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_create},
1650 {DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_remove},
1651 {DM_DEV_RENAME_CMD, IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_rename},
1652 {DM_DEV_SUSPEND_CMD, IOCTL_FLAGS_NO_PARAMS, dev_suspend},
1653 {DM_DEV_STATUS_CMD, IOCTL_FLAGS_NO_PARAMS, dev_status},
1654 {DM_DEV_WAIT_CMD, 0, dev_wait},
1655
1656 {DM_TABLE_LOAD_CMD, 0, table_load},
1657 {DM_TABLE_CLEAR_CMD, IOCTL_FLAGS_NO_PARAMS, table_clear},
1658 {DM_TABLE_DEPS_CMD, 0, table_deps},
1659 {DM_TABLE_STATUS_CMD, 0, table_status},
1660
1661 {DM_LIST_VERSIONS_CMD, 0, list_versions},
1662
1663 {DM_TARGET_MSG_CMD, 0, target_message},
1664 {DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry},
1665 {DM_DEV_ARM_POLL, IOCTL_FLAGS_NO_PARAMS, dev_arm_poll},
1666 };
1667
1668 if (unlikely(cmd >= ARRAY_SIZE(_ioctls)))
1669 return NULL;
1670
1671 *ioctl_flags = _ioctls[cmd].flags;
1672 return _ioctls[cmd].fn;
1673}
1674
1675/*
1676 * As well as checking the version compatibility this always
1677 * copies the kernel interface version out.
1678 */
1679static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1680{
1681 uint32_t version[3];
1682 int r = 0;
1683
1684 if (copy_from_user(version, user->version, sizeof(version)))
1685 return -EFAULT;
1686
1687 if ((DM_VERSION_MAJOR != version[0]) ||
1688 (DM_VERSION_MINOR < version[1])) {
1689 DMWARN("ioctl interface mismatch: "
1690 "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1691 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1692 DM_VERSION_PATCHLEVEL,
1693 version[0], version[1], version[2], cmd);
1694 r = -EINVAL;
1695 }
1696
1697 /*
1698 * Fill in the kernel version.
1699 */
1700 version[0] = DM_VERSION_MAJOR;
1701 version[1] = DM_VERSION_MINOR;
1702 version[2] = DM_VERSION_PATCHLEVEL;
1703 if (copy_to_user(user->version, version, sizeof(version)))
1704 return -EFAULT;
1705
1706 return r;
1707}
1708
1709#define DM_PARAMS_MALLOC 0x0001 /* Params allocated with kvmalloc() */
1710#define DM_WIPE_BUFFER 0x0010 /* Wipe input buffer before returning from ioctl */
1711
1712static void free_params(struct dm_ioctl *param, size_t param_size, int param_flags)
1713{
1714 if (param_flags & DM_WIPE_BUFFER)
1715 memset(param, 0, param_size);
1716
1717 if (param_flags & DM_PARAMS_MALLOC)
1718 kvfree(param);
1719}
1720
1721static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel,
1722 int ioctl_flags,
1723 struct dm_ioctl **param, int *param_flags)
1724{
1725 struct dm_ioctl *dmi;
1726 int secure_data;
1727 const size_t minimum_data_size = offsetof(struct dm_ioctl, data);
1728 unsigned noio_flag;
1729
1730 if (copy_from_user(param_kernel, user, minimum_data_size))
1731 return -EFAULT;
1732
1733 if (param_kernel->data_size < minimum_data_size)
1734 return -EINVAL;
1735
1736 secure_data = param_kernel->flags & DM_SECURE_DATA_FLAG;
1737
1738 *param_flags = secure_data ? DM_WIPE_BUFFER : 0;
1739
1740 if (ioctl_flags & IOCTL_FLAGS_NO_PARAMS) {
1741 dmi = param_kernel;
1742 dmi->data_size = minimum_data_size;
1743 goto data_copied;
1744 }
1745
1746 /*
1747 * Use __GFP_HIGH to avoid low memory issues when a device is
1748 * suspended and the ioctl is needed to resume it.
1749 * Use kmalloc() rather than vmalloc() when we can.
1750 */
1751 dmi = NULL;
1752 noio_flag = memalloc_noio_save();
1753 dmi = kvmalloc(param_kernel->data_size, GFP_KERNEL | __GFP_HIGH);
1754 memalloc_noio_restore(noio_flag);
1755
1756 if (!dmi) {
1757 if (secure_data && clear_user(user, param_kernel->data_size))
1758 return -EFAULT;
1759 return -ENOMEM;
1760 }
1761
1762 *param_flags |= DM_PARAMS_MALLOC;
1763
1764 if (copy_from_user(dmi, user, param_kernel->data_size))
1765 goto bad;
1766
1767data_copied:
1768 /*
1769 * Abort if something changed the ioctl data while it was being copied.
1770 */
1771 if (dmi->data_size != param_kernel->data_size) {
1772 DMERR("rejecting ioctl: data size modified while processing parameters");
1773 goto bad;
1774 }
1775
1776 /* Wipe the user buffer so we do not return it to userspace */
1777 if (secure_data && clear_user(user, param_kernel->data_size))
1778 goto bad;
1779
1780 *param = dmi;
1781 return 0;
1782
1783bad:
1784 free_params(dmi, param_kernel->data_size, *param_flags);
1785
1786 return -EFAULT;
1787}
1788
1789static int validate_params(uint cmd, struct dm_ioctl *param)
1790{
1791 /* Always clear this flag */
1792 param->flags &= ~DM_BUFFER_FULL_FLAG;
1793 param->flags &= ~DM_UEVENT_GENERATED_FLAG;
1794 param->flags &= ~DM_SECURE_DATA_FLAG;
1795 param->flags &= ~DM_DATA_OUT_FLAG;
1796
1797 /* Ignores parameters */
1798 if (cmd == DM_REMOVE_ALL_CMD ||
1799 cmd == DM_LIST_DEVICES_CMD ||
1800 cmd == DM_LIST_VERSIONS_CMD)
1801 return 0;
1802
1803 if (cmd == DM_DEV_CREATE_CMD) {
1804 if (!*param->name) {
1805 DMWARN("name not supplied when creating device");
1806 return -EINVAL;
1807 }
1808 } else if (*param->uuid && *param->name) {
1809 DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
1810 return -EINVAL;
1811 }
1812
1813 /* Ensure strings are terminated */
1814 param->name[DM_NAME_LEN - 1] = '\0';
1815 param->uuid[DM_UUID_LEN - 1] = '\0';
1816
1817 return 0;
1818}
1819
1820static int ctl_ioctl(struct file *file, uint command, struct dm_ioctl __user *user)
1821{
1822 int r = 0;
1823 int ioctl_flags;
1824 int param_flags;
1825 unsigned int cmd;
1826 struct dm_ioctl *uninitialized_var(param);
1827 ioctl_fn fn = NULL;
1828 size_t input_param_size;
1829 struct dm_ioctl param_kernel;
1830
1831 /* only root can play with this */
1832 if (!capable(CAP_SYS_ADMIN))
1833 return -EACCES;
1834
1835 if (_IOC_TYPE(command) != DM_IOCTL)
1836 return -ENOTTY;
1837
1838 cmd = _IOC_NR(command);
1839
1840 /*
1841 * Check the interface version passed in. This also
1842 * writes out the kernel's interface version.
1843 */
1844 r = check_version(cmd, user);
1845 if (r)
1846 return r;
1847
1848 /*
1849 * Nothing more to do for the version command.
1850 */
1851 if (cmd == DM_VERSION_CMD)
1852 return 0;
1853
1854 fn = lookup_ioctl(cmd, &ioctl_flags);
1855 if (!fn) {
1856 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1857 return -ENOTTY;
1858 }
1859
1860 /*
1861 * Copy the parameters into kernel space.
1862 */
1863 r = copy_params(user, ¶m_kernel, ioctl_flags, ¶m, ¶m_flags);
1864
1865 if (r)
1866 return r;
1867
1868 input_param_size = param->data_size;
1869 r = validate_params(cmd, param);
1870 if (r)
1871 goto out;
1872
1873 param->data_size = offsetof(struct dm_ioctl, data);
1874 r = fn(file, param, input_param_size);
1875
1876 if (unlikely(param->flags & DM_BUFFER_FULL_FLAG) &&
1877 unlikely(ioctl_flags & IOCTL_FLAGS_NO_PARAMS))
1878 DMERR("ioctl %d tried to output some data but has IOCTL_FLAGS_NO_PARAMS set", cmd);
1879
1880 if (!r && ioctl_flags & IOCTL_FLAGS_ISSUE_GLOBAL_EVENT)
1881 dm_issue_global_event();
1882
1883 /*
1884 * Copy the results back to userland.
1885 */
1886 if (!r && copy_to_user(user, param, param->data_size))
1887 r = -EFAULT;
1888
1889out:
1890 free_params(param, input_param_size, param_flags);
1891 return r;
1892}
1893
1894static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
1895{
1896 return (long)ctl_ioctl(file, command, (struct dm_ioctl __user *)u);
1897}
1898
1899#ifdef CONFIG_COMPAT
1900static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
1901{
1902 return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
1903}
1904#else
1905#define dm_compat_ctl_ioctl NULL
1906#endif
1907
1908static int dm_open(struct inode *inode, struct file *filp)
1909{
1910 int r;
1911 struct dm_file *priv;
1912
1913 r = nonseekable_open(inode, filp);
1914 if (unlikely(r))
1915 return r;
1916
1917 priv = filp->private_data = kmalloc(sizeof(struct dm_file), GFP_KERNEL);
1918 if (!priv)
1919 return -ENOMEM;
1920
1921 priv->global_event_nr = atomic_read(&dm_global_event_nr);
1922
1923 return 0;
1924}
1925
1926static int dm_release(struct inode *inode, struct file *filp)
1927{
1928 kfree(filp->private_data);
1929 return 0;
1930}
1931
1932static __poll_t dm_poll(struct file *filp, poll_table *wait)
1933{
1934 struct dm_file *priv = filp->private_data;
1935 __poll_t mask = 0;
1936
1937 poll_wait(filp, &dm_global_eventq, wait);
1938
1939 if ((int)(atomic_read(&dm_global_event_nr) - priv->global_event_nr) > 0)
1940 mask |= EPOLLIN;
1941
1942 return mask;
1943}
1944
1945static const struct file_operations _ctl_fops = {
1946 .open = dm_open,
1947 .release = dm_release,
1948 .poll = dm_poll,
1949 .unlocked_ioctl = dm_ctl_ioctl,
1950 .compat_ioctl = dm_compat_ctl_ioctl,
1951 .owner = THIS_MODULE,
1952 .llseek = noop_llseek,
1953};
1954
1955static struct miscdevice _dm_misc = {
1956 .minor = MAPPER_CTRL_MINOR,
1957 .name = DM_NAME,
1958 .nodename = DM_DIR "/" DM_CONTROL_NODE,
1959 .fops = &_ctl_fops
1960};
1961
1962MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
1963MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
1964
1965/*
1966 * Create misc character device and link to DM_DIR/control.
1967 */
1968int __init dm_interface_init(void)
1969{
1970 int r;
1971
1972 r = dm_hash_init();
1973 if (r)
1974 return r;
1975
1976 r = misc_register(&_dm_misc);
1977 if (r) {
1978 DMERR("misc_register failed for control device");
1979 dm_hash_exit();
1980 return r;
1981 }
1982
1983 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
1984 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
1985 DM_DRIVER_EMAIL);
1986 return 0;
1987}
1988
1989void dm_interface_exit(void)
1990{
1991 misc_deregister(&_dm_misc);
1992 dm_hash_exit();
1993}
1994
1995/**
1996 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
1997 * @md: Pointer to mapped_device
1998 * @name: Buffer (size DM_NAME_LEN) for name
1999 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
2000 */
2001int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
2002{
2003 int r = 0;
2004 struct hash_cell *hc;
2005
2006 if (!md)
2007 return -ENXIO;
2008
2009 mutex_lock(&dm_hash_cells_mutex);
2010 hc = dm_get_mdptr(md);
2011 if (!hc || hc->md != md) {
2012 r = -ENXIO;
2013 goto out;
2014 }
2015
2016 if (name)
2017 strcpy(name, hc->name);
2018 if (uuid)
2019 strcpy(uuid, hc->uuid ? : "");
2020
2021out:
2022 mutex_unlock(&dm_hash_cells_mutex);
2023
2024 return r;
2025}