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1/*
2 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
3 * Copyright (C) 2004 - 2006 Red Hat, Inc. All rights reserved.
4 *
5 * This file is released under the GPL.
6 */
7
8#include "dm.h"
9
10#include <linux/module.h>
11#include <linux/vmalloc.h>
12#include <linux/miscdevice.h>
13#include <linux/init.h>
14#include <linux/wait.h>
15#include <linux/slab.h>
16#include <linux/dm-ioctl.h>
17#include <linux/hdreg.h>
18#include <linux/compat.h>
19
20#include <asm/uaccess.h>
21
22#define DM_MSG_PREFIX "ioctl"
23#define DM_DRIVER_EMAIL "dm-devel@redhat.com"
24
25/*-----------------------------------------------------------------
26 * The ioctl interface needs to be able to look up devices by
27 * name or uuid.
28 *---------------------------------------------------------------*/
29struct hash_cell {
30 struct list_head name_list;
31 struct list_head uuid_list;
32
33 char *name;
34 char *uuid;
35 struct mapped_device *md;
36 struct dm_table *new_map;
37};
38
39struct vers_iter {
40 size_t param_size;
41 struct dm_target_versions *vers, *old_vers;
42 char *end;
43 uint32_t flags;
44};
45
46
47#define NUM_BUCKETS 64
48#define MASK_BUCKETS (NUM_BUCKETS - 1)
49static struct list_head _name_buckets[NUM_BUCKETS];
50static struct list_head _uuid_buckets[NUM_BUCKETS];
51
52static void dm_hash_remove_all(int keep_open_devices);
53
54/*
55 * Guards access to both hash tables.
56 */
57static DECLARE_RWSEM(_hash_lock);
58
59/*
60 * Protects use of mdptr to obtain hash cell name and uuid from mapped device.
61 */
62static DEFINE_MUTEX(dm_hash_cells_mutex);
63
64static void init_buckets(struct list_head *buckets)
65{
66 unsigned int i;
67
68 for (i = 0; i < NUM_BUCKETS; i++)
69 INIT_LIST_HEAD(buckets + i);
70}
71
72static int dm_hash_init(void)
73{
74 init_buckets(_name_buckets);
75 init_buckets(_uuid_buckets);
76 return 0;
77}
78
79static void dm_hash_exit(void)
80{
81 dm_hash_remove_all(0);
82}
83
84/*-----------------------------------------------------------------
85 * Hash function:
86 * We're not really concerned with the str hash function being
87 * fast since it's only used by the ioctl interface.
88 *---------------------------------------------------------------*/
89static unsigned int hash_str(const char *str)
90{
91 const unsigned int hash_mult = 2654435387U;
92 unsigned int h = 0;
93
94 while (*str)
95 h = (h + (unsigned int) *str++) * hash_mult;
96
97 return h & MASK_BUCKETS;
98}
99
100/*-----------------------------------------------------------------
101 * Code for looking up a device by name
102 *---------------------------------------------------------------*/
103static struct hash_cell *__get_name_cell(const char *str)
104{
105 struct hash_cell *hc;
106 unsigned int h = hash_str(str);
107
108 list_for_each_entry (hc, _name_buckets + h, name_list)
109 if (!strcmp(hc->name, str)) {
110 dm_get(hc->md);
111 return hc;
112 }
113
114 return NULL;
115}
116
117static struct hash_cell *__get_uuid_cell(const char *str)
118{
119 struct hash_cell *hc;
120 unsigned int h = hash_str(str);
121
122 list_for_each_entry (hc, _uuid_buckets + h, uuid_list)
123 if (!strcmp(hc->uuid, str)) {
124 dm_get(hc->md);
125 return hc;
126 }
127
128 return NULL;
129}
130
131static struct hash_cell *__get_dev_cell(uint64_t dev)
132{
133 struct mapped_device *md;
134 struct hash_cell *hc;
135
136 md = dm_get_md(huge_decode_dev(dev));
137 if (!md)
138 return NULL;
139
140 hc = dm_get_mdptr(md);
141 if (!hc) {
142 dm_put(md);
143 return NULL;
144 }
145
146 return hc;
147}
148
149/*-----------------------------------------------------------------
150 * Inserting, removing and renaming a device.
151 *---------------------------------------------------------------*/
152static struct hash_cell *alloc_cell(const char *name, const char *uuid,
153 struct mapped_device *md)
154{
155 struct hash_cell *hc;
156
157 hc = kmalloc(sizeof(*hc), GFP_KERNEL);
158 if (!hc)
159 return NULL;
160
161 hc->name = kstrdup(name, GFP_KERNEL);
162 if (!hc->name) {
163 kfree(hc);
164 return NULL;
165 }
166
167 if (!uuid)
168 hc->uuid = NULL;
169
170 else {
171 hc->uuid = kstrdup(uuid, GFP_KERNEL);
172 if (!hc->uuid) {
173 kfree(hc->name);
174 kfree(hc);
175 return NULL;
176 }
177 }
178
179 INIT_LIST_HEAD(&hc->name_list);
180 INIT_LIST_HEAD(&hc->uuid_list);
181 hc->md = md;
182 hc->new_map = NULL;
183 return hc;
184}
185
186static void free_cell(struct hash_cell *hc)
187{
188 if (hc) {
189 kfree(hc->name);
190 kfree(hc->uuid);
191 kfree(hc);
192 }
193}
194
195/*
196 * The kdev_t and uuid of a device can never change once it is
197 * initially inserted.
198 */
199static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
200{
201 struct hash_cell *cell, *hc;
202
203 /*
204 * Allocate the new cells.
205 */
206 cell = alloc_cell(name, uuid, md);
207 if (!cell)
208 return -ENOMEM;
209
210 /*
211 * Insert the cell into both hash tables.
212 */
213 down_write(&_hash_lock);
214 hc = __get_name_cell(name);
215 if (hc) {
216 dm_put(hc->md);
217 goto bad;
218 }
219
220 list_add(&cell->name_list, _name_buckets + hash_str(name));
221
222 if (uuid) {
223 hc = __get_uuid_cell(uuid);
224 if (hc) {
225 list_del(&cell->name_list);
226 dm_put(hc->md);
227 goto bad;
228 }
229 list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
230 }
231 dm_get(md);
232 mutex_lock(&dm_hash_cells_mutex);
233 dm_set_mdptr(md, cell);
234 mutex_unlock(&dm_hash_cells_mutex);
235 up_write(&_hash_lock);
236
237 return 0;
238
239 bad:
240 up_write(&_hash_lock);
241 free_cell(cell);
242 return -EBUSY;
243}
244
245static void __hash_remove(struct hash_cell *hc)
246{
247 struct dm_table *table;
248
249 /* remove from the dev hash */
250 list_del(&hc->uuid_list);
251 list_del(&hc->name_list);
252 mutex_lock(&dm_hash_cells_mutex);
253 dm_set_mdptr(hc->md, NULL);
254 mutex_unlock(&dm_hash_cells_mutex);
255
256 table = dm_get_live_table(hc->md);
257 if (table) {
258 dm_table_event(table);
259 dm_table_put(table);
260 }
261
262 if (hc->new_map)
263 dm_table_destroy(hc->new_map);
264 dm_put(hc->md);
265 free_cell(hc);
266}
267
268static void dm_hash_remove_all(int keep_open_devices)
269{
270 int i, dev_skipped;
271 struct hash_cell *hc;
272 struct mapped_device *md;
273
274retry:
275 dev_skipped = 0;
276
277 down_write(&_hash_lock);
278
279 for (i = 0; i < NUM_BUCKETS; i++) {
280 list_for_each_entry(hc, _name_buckets + i, name_list) {
281 md = hc->md;
282 dm_get(md);
283
284 if (keep_open_devices && dm_lock_for_deletion(md)) {
285 dm_put(md);
286 dev_skipped++;
287 continue;
288 }
289
290 __hash_remove(hc);
291
292 up_write(&_hash_lock);
293
294 dm_put(md);
295 if (likely(keep_open_devices))
296 dm_destroy(md);
297 else
298 dm_destroy_immediate(md);
299
300 /*
301 * Some mapped devices may be using other mapped
302 * devices, so repeat until we make no further
303 * progress. If a new mapped device is created
304 * here it will also get removed.
305 */
306 goto retry;
307 }
308 }
309
310 up_write(&_hash_lock);
311
312 if (dev_skipped)
313 DMWARN("remove_all left %d open device(s)", dev_skipped);
314}
315
316/*
317 * Set the uuid of a hash_cell that isn't already set.
318 */
319static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
320{
321 mutex_lock(&dm_hash_cells_mutex);
322 hc->uuid = new_uuid;
323 mutex_unlock(&dm_hash_cells_mutex);
324
325 list_add(&hc->uuid_list, _uuid_buckets + hash_str(new_uuid));
326}
327
328/*
329 * Changes the name of a hash_cell and returns the old name for
330 * the caller to free.
331 */
332static char *__change_cell_name(struct hash_cell *hc, char *new_name)
333{
334 char *old_name;
335
336 /*
337 * Rename and move the name cell.
338 */
339 list_del(&hc->name_list);
340 old_name = hc->name;
341
342 mutex_lock(&dm_hash_cells_mutex);
343 hc->name = new_name;
344 mutex_unlock(&dm_hash_cells_mutex);
345
346 list_add(&hc->name_list, _name_buckets + hash_str(new_name));
347
348 return old_name;
349}
350
351static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
352 const char *new)
353{
354 char *new_data, *old_name = NULL;
355 struct hash_cell *hc;
356 struct dm_table *table;
357 struct mapped_device *md;
358 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
359
360 /*
361 * duplicate new.
362 */
363 new_data = kstrdup(new, GFP_KERNEL);
364 if (!new_data)
365 return ERR_PTR(-ENOMEM);
366
367 down_write(&_hash_lock);
368
369 /*
370 * Is new free ?
371 */
372 if (change_uuid)
373 hc = __get_uuid_cell(new);
374 else
375 hc = __get_name_cell(new);
376
377 if (hc) {
378 DMWARN("Unable to change %s on mapped device %s to one that "
379 "already exists: %s",
380 change_uuid ? "uuid" : "name",
381 param->name, new);
382 dm_put(hc->md);
383 up_write(&_hash_lock);
384 kfree(new_data);
385 return ERR_PTR(-EBUSY);
386 }
387
388 /*
389 * Is there such a device as 'old' ?
390 */
391 hc = __get_name_cell(param->name);
392 if (!hc) {
393 DMWARN("Unable to rename non-existent device, %s to %s%s",
394 param->name, change_uuid ? "uuid " : "", new);
395 up_write(&_hash_lock);
396 kfree(new_data);
397 return ERR_PTR(-ENXIO);
398 }
399
400 /*
401 * Does this device already have a uuid?
402 */
403 if (change_uuid && hc->uuid) {
404 DMWARN("Unable to change uuid of mapped device %s to %s "
405 "because uuid is already set to %s",
406 param->name, new, hc->uuid);
407 dm_put(hc->md);
408 up_write(&_hash_lock);
409 kfree(new_data);
410 return ERR_PTR(-EINVAL);
411 }
412
413 if (change_uuid)
414 __set_cell_uuid(hc, new_data);
415 else
416 old_name = __change_cell_name(hc, new_data);
417
418 /*
419 * Wake up any dm event waiters.
420 */
421 table = dm_get_live_table(hc->md);
422 if (table) {
423 dm_table_event(table);
424 dm_table_put(table);
425 }
426
427 if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr))
428 param->flags |= DM_UEVENT_GENERATED_FLAG;
429
430 md = hc->md;
431 up_write(&_hash_lock);
432 kfree(old_name);
433
434 return md;
435}
436
437/*-----------------------------------------------------------------
438 * Implementation of the ioctl commands
439 *---------------------------------------------------------------*/
440/*
441 * All the ioctl commands get dispatched to functions with this
442 * prototype.
443 */
444typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size);
445
446static int remove_all(struct dm_ioctl *param, size_t param_size)
447{
448 dm_hash_remove_all(1);
449 param->data_size = 0;
450 return 0;
451}
452
453/*
454 * Round up the ptr to an 8-byte boundary.
455 */
456#define ALIGN_MASK 7
457static inline void *align_ptr(void *ptr)
458{
459 return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK);
460}
461
462/*
463 * Retrieves the data payload buffer from an already allocated
464 * struct dm_ioctl.
465 */
466static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
467 size_t *len)
468{
469 param->data_start = align_ptr(param + 1) - (void *) param;
470
471 if (param->data_start < param_size)
472 *len = param_size - param->data_start;
473 else
474 *len = 0;
475
476 return ((void *) param) + param->data_start;
477}
478
479static int list_devices(struct dm_ioctl *param, size_t param_size)
480{
481 unsigned int i;
482 struct hash_cell *hc;
483 size_t len, needed = 0;
484 struct gendisk *disk;
485 struct dm_name_list *nl, *old_nl = NULL;
486
487 down_write(&_hash_lock);
488
489 /*
490 * Loop through all the devices working out how much
491 * space we need.
492 */
493 for (i = 0; i < NUM_BUCKETS; i++) {
494 list_for_each_entry (hc, _name_buckets + i, name_list) {
495 needed += sizeof(struct dm_name_list);
496 needed += strlen(hc->name) + 1;
497 needed += ALIGN_MASK;
498 }
499 }
500
501 /*
502 * Grab our output buffer.
503 */
504 nl = get_result_buffer(param, param_size, &len);
505 if (len < needed) {
506 param->flags |= DM_BUFFER_FULL_FLAG;
507 goto out;
508 }
509 param->data_size = param->data_start + needed;
510
511 nl->dev = 0; /* Flags no data */
512
513 /*
514 * Now loop through filling out the names.
515 */
516 for (i = 0; i < NUM_BUCKETS; i++) {
517 list_for_each_entry (hc, _name_buckets + i, name_list) {
518 if (old_nl)
519 old_nl->next = (uint32_t) ((void *) nl -
520 (void *) old_nl);
521 disk = dm_disk(hc->md);
522 nl->dev = huge_encode_dev(disk_devt(disk));
523 nl->next = 0;
524 strcpy(nl->name, hc->name);
525
526 old_nl = nl;
527 nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1);
528 }
529 }
530
531 out:
532 up_write(&_hash_lock);
533 return 0;
534}
535
536static void list_version_get_needed(struct target_type *tt, void *needed_param)
537{
538 size_t *needed = needed_param;
539
540 *needed += sizeof(struct dm_target_versions);
541 *needed += strlen(tt->name);
542 *needed += ALIGN_MASK;
543}
544
545static void list_version_get_info(struct target_type *tt, void *param)
546{
547 struct vers_iter *info = param;
548
549 /* Check space - it might have changed since the first iteration */
550 if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
551 info->end) {
552
553 info->flags = DM_BUFFER_FULL_FLAG;
554 return;
555 }
556
557 if (info->old_vers)
558 info->old_vers->next = (uint32_t) ((void *)info->vers -
559 (void *)info->old_vers);
560 info->vers->version[0] = tt->version[0];
561 info->vers->version[1] = tt->version[1];
562 info->vers->version[2] = tt->version[2];
563 info->vers->next = 0;
564 strcpy(info->vers->name, tt->name);
565
566 info->old_vers = info->vers;
567 info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
568}
569
570static int list_versions(struct dm_ioctl *param, size_t param_size)
571{
572 size_t len, needed = 0;
573 struct dm_target_versions *vers;
574 struct vers_iter iter_info;
575
576 /*
577 * Loop through all the devices working out how much
578 * space we need.
579 */
580 dm_target_iterate(list_version_get_needed, &needed);
581
582 /*
583 * Grab our output buffer.
584 */
585 vers = get_result_buffer(param, param_size, &len);
586 if (len < needed) {
587 param->flags |= DM_BUFFER_FULL_FLAG;
588 goto out;
589 }
590 param->data_size = param->data_start + needed;
591
592 iter_info.param_size = param_size;
593 iter_info.old_vers = NULL;
594 iter_info.vers = vers;
595 iter_info.flags = 0;
596 iter_info.end = (char *)vers+len;
597
598 /*
599 * Now loop through filling out the names & versions.
600 */
601 dm_target_iterate(list_version_get_info, &iter_info);
602 param->flags |= iter_info.flags;
603
604 out:
605 return 0;
606}
607
608static int check_name(const char *name)
609{
610 if (strchr(name, '/')) {
611 DMWARN("invalid device name");
612 return -EINVAL;
613 }
614
615 return 0;
616}
617
618/*
619 * On successful return, the caller must not attempt to acquire
620 * _hash_lock without first calling dm_table_put, because dm_table_destroy
621 * waits for this dm_table_put and could be called under this lock.
622 */
623static struct dm_table *dm_get_inactive_table(struct mapped_device *md)
624{
625 struct hash_cell *hc;
626 struct dm_table *table = NULL;
627
628 down_read(&_hash_lock);
629 hc = dm_get_mdptr(md);
630 if (!hc || hc->md != md) {
631 DMWARN("device has been removed from the dev hash table.");
632 goto out;
633 }
634
635 table = hc->new_map;
636 if (table)
637 dm_table_get(table);
638
639out:
640 up_read(&_hash_lock);
641
642 return table;
643}
644
645static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
646 struct dm_ioctl *param)
647{
648 return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
649 dm_get_inactive_table(md) : dm_get_live_table(md);
650}
651
652/*
653 * Fills in a dm_ioctl structure, ready for sending back to
654 * userland.
655 */
656static void __dev_status(struct mapped_device *md, struct dm_ioctl *param)
657{
658 struct gendisk *disk = dm_disk(md);
659 struct dm_table *table;
660
661 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
662 DM_ACTIVE_PRESENT_FLAG);
663
664 if (dm_suspended_md(md))
665 param->flags |= DM_SUSPEND_FLAG;
666
667 param->dev = huge_encode_dev(disk_devt(disk));
668
669 /*
670 * Yes, this will be out of date by the time it gets back
671 * to userland, but it is still very useful for
672 * debugging.
673 */
674 param->open_count = dm_open_count(md);
675
676 param->event_nr = dm_get_event_nr(md);
677 param->target_count = 0;
678
679 table = dm_get_live_table(md);
680 if (table) {
681 if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
682 if (get_disk_ro(disk))
683 param->flags |= DM_READONLY_FLAG;
684 param->target_count = dm_table_get_num_targets(table);
685 }
686 dm_table_put(table);
687
688 param->flags |= DM_ACTIVE_PRESENT_FLAG;
689 }
690
691 if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
692 table = dm_get_inactive_table(md);
693 if (table) {
694 if (!(dm_table_get_mode(table) & FMODE_WRITE))
695 param->flags |= DM_READONLY_FLAG;
696 param->target_count = dm_table_get_num_targets(table);
697 dm_table_put(table);
698 }
699 }
700}
701
702static int dev_create(struct dm_ioctl *param, size_t param_size)
703{
704 int r, m = DM_ANY_MINOR;
705 struct mapped_device *md;
706
707 r = check_name(param->name);
708 if (r)
709 return r;
710
711 if (param->flags & DM_PERSISTENT_DEV_FLAG)
712 m = MINOR(huge_decode_dev(param->dev));
713
714 r = dm_create(m, &md);
715 if (r)
716 return r;
717
718 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
719 if (r) {
720 dm_put(md);
721 dm_destroy(md);
722 return r;
723 }
724
725 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
726
727 __dev_status(md, param);
728
729 dm_put(md);
730
731 return 0;
732}
733
734/*
735 * Always use UUID for lookups if it's present, otherwise use name or dev.
736 */
737static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
738{
739 struct hash_cell *hc = NULL;
740
741 if (*param->uuid) {
742 if (*param->name || param->dev)
743 return NULL;
744
745 hc = __get_uuid_cell(param->uuid);
746 if (!hc)
747 return NULL;
748 } else if (*param->name) {
749 if (param->dev)
750 return NULL;
751
752 hc = __get_name_cell(param->name);
753 if (!hc)
754 return NULL;
755 } else if (param->dev) {
756 hc = __get_dev_cell(param->dev);
757 if (!hc)
758 return NULL;
759 } else
760 return NULL;
761
762 /*
763 * Sneakily write in both the name and the uuid
764 * while we have the cell.
765 */
766 strlcpy(param->name, hc->name, sizeof(param->name));
767 if (hc->uuid)
768 strlcpy(param->uuid, hc->uuid, sizeof(param->uuid));
769 else
770 param->uuid[0] = '\0';
771
772 if (hc->new_map)
773 param->flags |= DM_INACTIVE_PRESENT_FLAG;
774 else
775 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
776
777 return hc;
778}
779
780static struct mapped_device *find_device(struct dm_ioctl *param)
781{
782 struct hash_cell *hc;
783 struct mapped_device *md = NULL;
784
785 down_read(&_hash_lock);
786 hc = __find_device_hash_cell(param);
787 if (hc)
788 md = hc->md;
789 up_read(&_hash_lock);
790
791 return md;
792}
793
794static int dev_remove(struct dm_ioctl *param, size_t param_size)
795{
796 struct hash_cell *hc;
797 struct mapped_device *md;
798 int r;
799
800 down_write(&_hash_lock);
801 hc = __find_device_hash_cell(param);
802
803 if (!hc) {
804 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
805 up_write(&_hash_lock);
806 return -ENXIO;
807 }
808
809 md = hc->md;
810
811 /*
812 * Ensure the device is not open and nothing further can open it.
813 */
814 r = dm_lock_for_deletion(md);
815 if (r) {
816 DMDEBUG_LIMIT("unable to remove open device %s", hc->name);
817 up_write(&_hash_lock);
818 dm_put(md);
819 return r;
820 }
821
822 __hash_remove(hc);
823 up_write(&_hash_lock);
824
825 if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr))
826 param->flags |= DM_UEVENT_GENERATED_FLAG;
827
828 dm_put(md);
829 dm_destroy(md);
830 return 0;
831}
832
833/*
834 * Check a string doesn't overrun the chunk of
835 * memory we copied from userland.
836 */
837static int invalid_str(char *str, void *end)
838{
839 while ((void *) str < end)
840 if (!*str++)
841 return 0;
842
843 return -EINVAL;
844}
845
846static int dev_rename(struct dm_ioctl *param, size_t param_size)
847{
848 int r;
849 char *new_data = (char *) param + param->data_start;
850 struct mapped_device *md;
851 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
852
853 if (new_data < param->data ||
854 invalid_str(new_data, (void *) param + param_size) ||
855 strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
856 DMWARN("Invalid new mapped device name or uuid string supplied.");
857 return -EINVAL;
858 }
859
860 if (!change_uuid) {
861 r = check_name(new_data);
862 if (r)
863 return r;
864 }
865
866 md = dm_hash_rename(param, new_data);
867 if (IS_ERR(md))
868 return PTR_ERR(md);
869
870 __dev_status(md, param);
871 dm_put(md);
872
873 return 0;
874}
875
876static int dev_set_geometry(struct dm_ioctl *param, size_t param_size)
877{
878 int r = -EINVAL, x;
879 struct mapped_device *md;
880 struct hd_geometry geometry;
881 unsigned long indata[4];
882 char *geostr = (char *) param + param->data_start;
883 char dummy;
884
885 md = find_device(param);
886 if (!md)
887 return -ENXIO;
888
889 if (geostr < param->data ||
890 invalid_str(geostr, (void *) param + param_size)) {
891 DMWARN("Invalid geometry supplied.");
892 goto out;
893 }
894
895 x = sscanf(geostr, "%lu %lu %lu %lu%c", indata,
896 indata + 1, indata + 2, indata + 3, &dummy);
897
898 if (x != 4) {
899 DMWARN("Unable to interpret geometry settings.");
900 goto out;
901 }
902
903 if (indata[0] > 65535 || indata[1] > 255 ||
904 indata[2] > 255 || indata[3] > ULONG_MAX) {
905 DMWARN("Geometry exceeds range limits.");
906 goto out;
907 }
908
909 geometry.cylinders = indata[0];
910 geometry.heads = indata[1];
911 geometry.sectors = indata[2];
912 geometry.start = indata[3];
913
914 r = dm_set_geometry(md, &geometry);
915
916 param->data_size = 0;
917
918out:
919 dm_put(md);
920 return r;
921}
922
923static int do_suspend(struct dm_ioctl *param)
924{
925 int r = 0;
926 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
927 struct mapped_device *md;
928
929 md = find_device(param);
930 if (!md)
931 return -ENXIO;
932
933 if (param->flags & DM_SKIP_LOCKFS_FLAG)
934 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
935 if (param->flags & DM_NOFLUSH_FLAG)
936 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
937
938 if (!dm_suspended_md(md)) {
939 r = dm_suspend(md, suspend_flags);
940 if (r)
941 goto out;
942 }
943
944 __dev_status(md, param);
945
946out:
947 dm_put(md);
948
949 return r;
950}
951
952static int do_resume(struct dm_ioctl *param)
953{
954 int r = 0;
955 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
956 struct hash_cell *hc;
957 struct mapped_device *md;
958 struct dm_table *new_map, *old_map = NULL;
959
960 down_write(&_hash_lock);
961
962 hc = __find_device_hash_cell(param);
963 if (!hc) {
964 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
965 up_write(&_hash_lock);
966 return -ENXIO;
967 }
968
969 md = hc->md;
970
971 new_map = hc->new_map;
972 hc->new_map = NULL;
973 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
974
975 up_write(&_hash_lock);
976
977 /* Do we need to load a new map ? */
978 if (new_map) {
979 /* Suspend if it isn't already suspended */
980 if (param->flags & DM_SKIP_LOCKFS_FLAG)
981 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
982 if (param->flags & DM_NOFLUSH_FLAG)
983 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
984 if (!dm_suspended_md(md))
985 dm_suspend(md, suspend_flags);
986
987 old_map = dm_swap_table(md, new_map);
988 if (IS_ERR(old_map)) {
989 dm_table_destroy(new_map);
990 dm_put(md);
991 return PTR_ERR(old_map);
992 }
993
994 if (dm_table_get_mode(new_map) & FMODE_WRITE)
995 set_disk_ro(dm_disk(md), 0);
996 else
997 set_disk_ro(dm_disk(md), 1);
998 }
999
1000 if (dm_suspended_md(md)) {
1001 r = dm_resume(md);
1002 if (!r && !dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr))
1003 param->flags |= DM_UEVENT_GENERATED_FLAG;
1004 }
1005
1006 if (old_map)
1007 dm_table_destroy(old_map);
1008
1009 if (!r)
1010 __dev_status(md, param);
1011
1012 dm_put(md);
1013 return r;
1014}
1015
1016/*
1017 * Set or unset the suspension state of a device.
1018 * If the device already is in the requested state we just return its status.
1019 */
1020static int dev_suspend(struct dm_ioctl *param, size_t param_size)
1021{
1022 if (param->flags & DM_SUSPEND_FLAG)
1023 return do_suspend(param);
1024
1025 return do_resume(param);
1026}
1027
1028/*
1029 * Copies device info back to user space, used by
1030 * the create and info ioctls.
1031 */
1032static int dev_status(struct dm_ioctl *param, size_t param_size)
1033{
1034 struct mapped_device *md;
1035
1036 md = find_device(param);
1037 if (!md)
1038 return -ENXIO;
1039
1040 __dev_status(md, param);
1041 dm_put(md);
1042
1043 return 0;
1044}
1045
1046/*
1047 * Build up the status struct for each target
1048 */
1049static void retrieve_status(struct dm_table *table,
1050 struct dm_ioctl *param, size_t param_size)
1051{
1052 unsigned int i, num_targets;
1053 struct dm_target_spec *spec;
1054 char *outbuf, *outptr;
1055 status_type_t type;
1056 size_t remaining, len, used = 0;
1057
1058 outptr = outbuf = get_result_buffer(param, param_size, &len);
1059
1060 if (param->flags & DM_STATUS_TABLE_FLAG)
1061 type = STATUSTYPE_TABLE;
1062 else
1063 type = STATUSTYPE_INFO;
1064
1065 /* Get all the target info */
1066 num_targets = dm_table_get_num_targets(table);
1067 for (i = 0; i < num_targets; i++) {
1068 struct dm_target *ti = dm_table_get_target(table, i);
1069
1070 remaining = len - (outptr - outbuf);
1071 if (remaining <= sizeof(struct dm_target_spec)) {
1072 param->flags |= DM_BUFFER_FULL_FLAG;
1073 break;
1074 }
1075
1076 spec = (struct dm_target_spec *) outptr;
1077
1078 spec->status = 0;
1079 spec->sector_start = ti->begin;
1080 spec->length = ti->len;
1081 strncpy(spec->target_type, ti->type->name,
1082 sizeof(spec->target_type));
1083
1084 outptr += sizeof(struct dm_target_spec);
1085 remaining = len - (outptr - outbuf);
1086 if (remaining <= 0) {
1087 param->flags |= DM_BUFFER_FULL_FLAG;
1088 break;
1089 }
1090
1091 /* Get the status/table string from the target driver */
1092 if (ti->type->status) {
1093 if (ti->type->status(ti, type, outptr, remaining)) {
1094 param->flags |= DM_BUFFER_FULL_FLAG;
1095 break;
1096 }
1097 } else
1098 outptr[0] = '\0';
1099
1100 outptr += strlen(outptr) + 1;
1101 used = param->data_start + (outptr - outbuf);
1102
1103 outptr = align_ptr(outptr);
1104 spec->next = outptr - outbuf;
1105 }
1106
1107 if (used)
1108 param->data_size = used;
1109
1110 param->target_count = num_targets;
1111}
1112
1113/*
1114 * Wait for a device to report an event
1115 */
1116static int dev_wait(struct dm_ioctl *param, size_t param_size)
1117{
1118 int r = 0;
1119 struct mapped_device *md;
1120 struct dm_table *table;
1121
1122 md = find_device(param);
1123 if (!md)
1124 return -ENXIO;
1125
1126 /*
1127 * Wait for a notification event
1128 */
1129 if (dm_wait_event(md, param->event_nr)) {
1130 r = -ERESTARTSYS;
1131 goto out;
1132 }
1133
1134 /*
1135 * The userland program is going to want to know what
1136 * changed to trigger the event, so we may as well tell
1137 * him and save an ioctl.
1138 */
1139 __dev_status(md, param);
1140
1141 table = dm_get_live_or_inactive_table(md, param);
1142 if (table) {
1143 retrieve_status(table, param, param_size);
1144 dm_table_put(table);
1145 }
1146
1147out:
1148 dm_put(md);
1149
1150 return r;
1151}
1152
1153static inline fmode_t get_mode(struct dm_ioctl *param)
1154{
1155 fmode_t mode = FMODE_READ | FMODE_WRITE;
1156
1157 if (param->flags & DM_READONLY_FLAG)
1158 mode = FMODE_READ;
1159
1160 return mode;
1161}
1162
1163static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
1164 struct dm_target_spec **spec, char **target_params)
1165{
1166 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1167 *target_params = (char *) (*spec + 1);
1168
1169 if (*spec < (last + 1))
1170 return -EINVAL;
1171
1172 return invalid_str(*target_params, end);
1173}
1174
1175static int populate_table(struct dm_table *table,
1176 struct dm_ioctl *param, size_t param_size)
1177{
1178 int r;
1179 unsigned int i = 0;
1180 struct dm_target_spec *spec = (struct dm_target_spec *) param;
1181 uint32_t next = param->data_start;
1182 void *end = (void *) param + param_size;
1183 char *target_params;
1184
1185 if (!param->target_count) {
1186 DMWARN("populate_table: no targets specified");
1187 return -EINVAL;
1188 }
1189
1190 for (i = 0; i < param->target_count; i++) {
1191
1192 r = next_target(spec, next, end, &spec, &target_params);
1193 if (r) {
1194 DMWARN("unable to find target");
1195 return r;
1196 }
1197
1198 r = dm_table_add_target(table, spec->target_type,
1199 (sector_t) spec->sector_start,
1200 (sector_t) spec->length,
1201 target_params);
1202 if (r) {
1203 DMWARN("error adding target to table");
1204 return r;
1205 }
1206
1207 next = spec->next;
1208 }
1209
1210 return dm_table_complete(table);
1211}
1212
1213static int table_load(struct dm_ioctl *param, size_t param_size)
1214{
1215 int r;
1216 struct hash_cell *hc;
1217 struct dm_table *t;
1218 struct mapped_device *md;
1219 struct target_type *immutable_target_type;
1220
1221 md = find_device(param);
1222 if (!md)
1223 return -ENXIO;
1224
1225 r = dm_table_create(&t, get_mode(param), param->target_count, md);
1226 if (r)
1227 goto out;
1228
1229 r = populate_table(t, param, param_size);
1230 if (r) {
1231 dm_table_destroy(t);
1232 goto out;
1233 }
1234
1235 immutable_target_type = dm_get_immutable_target_type(md);
1236 if (immutable_target_type &&
1237 (immutable_target_type != dm_table_get_immutable_target_type(t))) {
1238 DMWARN("can't replace immutable target type %s",
1239 immutable_target_type->name);
1240 dm_table_destroy(t);
1241 r = -EINVAL;
1242 goto out;
1243 }
1244
1245 /* Protect md->type and md->queue against concurrent table loads. */
1246 dm_lock_md_type(md);
1247 if (dm_get_md_type(md) == DM_TYPE_NONE)
1248 /* Initial table load: acquire type of table. */
1249 dm_set_md_type(md, dm_table_get_type(t));
1250 else if (dm_get_md_type(md) != dm_table_get_type(t)) {
1251 DMWARN("can't change device type after initial table load.");
1252 dm_table_destroy(t);
1253 dm_unlock_md_type(md);
1254 r = -EINVAL;
1255 goto out;
1256 }
1257
1258 /* setup md->queue to reflect md's type (may block) */
1259 r = dm_setup_md_queue(md);
1260 if (r) {
1261 DMWARN("unable to set up device queue for new table.");
1262 dm_table_destroy(t);
1263 dm_unlock_md_type(md);
1264 goto out;
1265 }
1266 dm_unlock_md_type(md);
1267
1268 /* stage inactive table */
1269 down_write(&_hash_lock);
1270 hc = dm_get_mdptr(md);
1271 if (!hc || hc->md != md) {
1272 DMWARN("device has been removed from the dev hash table.");
1273 dm_table_destroy(t);
1274 up_write(&_hash_lock);
1275 r = -ENXIO;
1276 goto out;
1277 }
1278
1279 if (hc->new_map)
1280 dm_table_destroy(hc->new_map);
1281 hc->new_map = t;
1282 up_write(&_hash_lock);
1283
1284 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1285 __dev_status(md, param);
1286
1287out:
1288 dm_put(md);
1289
1290 return r;
1291}
1292
1293static int table_clear(struct dm_ioctl *param, size_t param_size)
1294{
1295 struct hash_cell *hc;
1296 struct mapped_device *md;
1297
1298 down_write(&_hash_lock);
1299
1300 hc = __find_device_hash_cell(param);
1301 if (!hc) {
1302 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1303 up_write(&_hash_lock);
1304 return -ENXIO;
1305 }
1306
1307 if (hc->new_map) {
1308 dm_table_destroy(hc->new_map);
1309 hc->new_map = NULL;
1310 }
1311
1312 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1313
1314 __dev_status(hc->md, param);
1315 md = hc->md;
1316 up_write(&_hash_lock);
1317 dm_put(md);
1318
1319 return 0;
1320}
1321
1322/*
1323 * Retrieves a list of devices used by a particular dm device.
1324 */
1325static void retrieve_deps(struct dm_table *table,
1326 struct dm_ioctl *param, size_t param_size)
1327{
1328 unsigned int count = 0;
1329 struct list_head *tmp;
1330 size_t len, needed;
1331 struct dm_dev_internal *dd;
1332 struct dm_target_deps *deps;
1333
1334 deps = get_result_buffer(param, param_size, &len);
1335
1336 /*
1337 * Count the devices.
1338 */
1339 list_for_each (tmp, dm_table_get_devices(table))
1340 count++;
1341
1342 /*
1343 * Check we have enough space.
1344 */
1345 needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
1346 if (len < needed) {
1347 param->flags |= DM_BUFFER_FULL_FLAG;
1348 return;
1349 }
1350
1351 /*
1352 * Fill in the devices.
1353 */
1354 deps->count = count;
1355 count = 0;
1356 list_for_each_entry (dd, dm_table_get_devices(table), list)
1357 deps->dev[count++] = huge_encode_dev(dd->dm_dev.bdev->bd_dev);
1358
1359 param->data_size = param->data_start + needed;
1360}
1361
1362static int table_deps(struct dm_ioctl *param, size_t param_size)
1363{
1364 struct mapped_device *md;
1365 struct dm_table *table;
1366
1367 md = find_device(param);
1368 if (!md)
1369 return -ENXIO;
1370
1371 __dev_status(md, param);
1372
1373 table = dm_get_live_or_inactive_table(md, param);
1374 if (table) {
1375 retrieve_deps(table, param, param_size);
1376 dm_table_put(table);
1377 }
1378
1379 dm_put(md);
1380
1381 return 0;
1382}
1383
1384/*
1385 * Return the status of a device as a text string for each
1386 * target.
1387 */
1388static int table_status(struct dm_ioctl *param, size_t param_size)
1389{
1390 struct mapped_device *md;
1391 struct dm_table *table;
1392
1393 md = find_device(param);
1394 if (!md)
1395 return -ENXIO;
1396
1397 __dev_status(md, param);
1398
1399 table = dm_get_live_or_inactive_table(md, param);
1400 if (table) {
1401 retrieve_status(table, param, param_size);
1402 dm_table_put(table);
1403 }
1404
1405 dm_put(md);
1406
1407 return 0;
1408}
1409
1410/*
1411 * Pass a message to the target that's at the supplied device offset.
1412 */
1413static int target_message(struct dm_ioctl *param, size_t param_size)
1414{
1415 int r, argc;
1416 char **argv;
1417 struct mapped_device *md;
1418 struct dm_table *table;
1419 struct dm_target *ti;
1420 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1421
1422 md = find_device(param);
1423 if (!md)
1424 return -ENXIO;
1425
1426 if (tmsg < (struct dm_target_msg *) param->data ||
1427 invalid_str(tmsg->message, (void *) param + param_size)) {
1428 DMWARN("Invalid target message parameters.");
1429 r = -EINVAL;
1430 goto out;
1431 }
1432
1433 r = dm_split_args(&argc, &argv, tmsg->message);
1434 if (r) {
1435 DMWARN("Failed to split target message parameters");
1436 goto out;
1437 }
1438
1439 if (!argc) {
1440 DMWARN("Empty message received.");
1441 goto out_argv;
1442 }
1443
1444 table = dm_get_live_table(md);
1445 if (!table)
1446 goto out_argv;
1447
1448 if (dm_deleting_md(md)) {
1449 r = -ENXIO;
1450 goto out_table;
1451 }
1452
1453 ti = dm_table_find_target(table, tmsg->sector);
1454 if (!dm_target_is_valid(ti)) {
1455 DMWARN("Target message sector outside device.");
1456 r = -EINVAL;
1457 } else if (ti->type->message)
1458 r = ti->type->message(ti, argc, argv);
1459 else {
1460 DMWARN("Target type does not support messages");
1461 r = -EINVAL;
1462 }
1463
1464 out_table:
1465 dm_table_put(table);
1466 out_argv:
1467 kfree(argv);
1468 out:
1469 param->data_size = 0;
1470 dm_put(md);
1471 return r;
1472}
1473
1474/*-----------------------------------------------------------------
1475 * Implementation of open/close/ioctl on the special char
1476 * device.
1477 *---------------------------------------------------------------*/
1478static ioctl_fn lookup_ioctl(unsigned int cmd)
1479{
1480 static struct {
1481 int cmd;
1482 ioctl_fn fn;
1483 } _ioctls[] = {
1484 {DM_VERSION_CMD, NULL}, /* version is dealt with elsewhere */
1485 {DM_REMOVE_ALL_CMD, remove_all},
1486 {DM_LIST_DEVICES_CMD, list_devices},
1487
1488 {DM_DEV_CREATE_CMD, dev_create},
1489 {DM_DEV_REMOVE_CMD, dev_remove},
1490 {DM_DEV_RENAME_CMD, dev_rename},
1491 {DM_DEV_SUSPEND_CMD, dev_suspend},
1492 {DM_DEV_STATUS_CMD, dev_status},
1493 {DM_DEV_WAIT_CMD, dev_wait},
1494
1495 {DM_TABLE_LOAD_CMD, table_load},
1496 {DM_TABLE_CLEAR_CMD, table_clear},
1497 {DM_TABLE_DEPS_CMD, table_deps},
1498 {DM_TABLE_STATUS_CMD, table_status},
1499
1500 {DM_LIST_VERSIONS_CMD, list_versions},
1501
1502 {DM_TARGET_MSG_CMD, target_message},
1503 {DM_DEV_SET_GEOMETRY_CMD, dev_set_geometry}
1504 };
1505
1506 return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn;
1507}
1508
1509/*
1510 * As well as checking the version compatibility this always
1511 * copies the kernel interface version out.
1512 */
1513static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1514{
1515 uint32_t version[3];
1516 int r = 0;
1517
1518 if (copy_from_user(version, user->version, sizeof(version)))
1519 return -EFAULT;
1520
1521 if ((DM_VERSION_MAJOR != version[0]) ||
1522 (DM_VERSION_MINOR < version[1])) {
1523 DMWARN("ioctl interface mismatch: "
1524 "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1525 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1526 DM_VERSION_PATCHLEVEL,
1527 version[0], version[1], version[2], cmd);
1528 r = -EINVAL;
1529 }
1530
1531 /*
1532 * Fill in the kernel version.
1533 */
1534 version[0] = DM_VERSION_MAJOR;
1535 version[1] = DM_VERSION_MINOR;
1536 version[2] = DM_VERSION_PATCHLEVEL;
1537 if (copy_to_user(user->version, version, sizeof(version)))
1538 return -EFAULT;
1539
1540 return r;
1541}
1542
1543static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
1544{
1545 struct dm_ioctl tmp, *dmi;
1546 int secure_data;
1547
1548 if (copy_from_user(&tmp, user, sizeof(tmp) - sizeof(tmp.data)))
1549 return -EFAULT;
1550
1551 if (tmp.data_size < (sizeof(tmp) - sizeof(tmp.data)))
1552 return -EINVAL;
1553
1554 secure_data = tmp.flags & DM_SECURE_DATA_FLAG;
1555
1556 dmi = vmalloc(tmp.data_size);
1557 if (!dmi) {
1558 if (secure_data && clear_user(user, tmp.data_size))
1559 return -EFAULT;
1560 return -ENOMEM;
1561 }
1562
1563 if (copy_from_user(dmi, user, tmp.data_size))
1564 goto bad;
1565
1566 /* Wipe the user buffer so we do not return it to userspace */
1567 if (secure_data && clear_user(user, tmp.data_size))
1568 goto bad;
1569
1570 *param = dmi;
1571 return 0;
1572
1573bad:
1574 if (secure_data)
1575 memset(dmi, 0, tmp.data_size);
1576 vfree(dmi);
1577 return -EFAULT;
1578}
1579
1580static int validate_params(uint cmd, struct dm_ioctl *param)
1581{
1582 /* Always clear this flag */
1583 param->flags &= ~DM_BUFFER_FULL_FLAG;
1584 param->flags &= ~DM_UEVENT_GENERATED_FLAG;
1585 param->flags &= ~DM_SECURE_DATA_FLAG;
1586
1587 /* Ignores parameters */
1588 if (cmd == DM_REMOVE_ALL_CMD ||
1589 cmd == DM_LIST_DEVICES_CMD ||
1590 cmd == DM_LIST_VERSIONS_CMD)
1591 return 0;
1592
1593 if ((cmd == DM_DEV_CREATE_CMD)) {
1594 if (!*param->name) {
1595 DMWARN("name not supplied when creating device");
1596 return -EINVAL;
1597 }
1598 } else if ((*param->uuid && *param->name)) {
1599 DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
1600 return -EINVAL;
1601 }
1602
1603 /* Ensure strings are terminated */
1604 param->name[DM_NAME_LEN - 1] = '\0';
1605 param->uuid[DM_UUID_LEN - 1] = '\0';
1606
1607 return 0;
1608}
1609
1610static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
1611{
1612 int r = 0;
1613 int wipe_buffer;
1614 unsigned int cmd;
1615 struct dm_ioctl *uninitialized_var(param);
1616 ioctl_fn fn = NULL;
1617 size_t input_param_size;
1618
1619 /* only root can play with this */
1620 if (!capable(CAP_SYS_ADMIN))
1621 return -EACCES;
1622
1623 if (_IOC_TYPE(command) != DM_IOCTL)
1624 return -ENOTTY;
1625
1626 cmd = _IOC_NR(command);
1627
1628 /*
1629 * Check the interface version passed in. This also
1630 * writes out the kernel's interface version.
1631 */
1632 r = check_version(cmd, user);
1633 if (r)
1634 return r;
1635
1636 /*
1637 * Nothing more to do for the version command.
1638 */
1639 if (cmd == DM_VERSION_CMD)
1640 return 0;
1641
1642 fn = lookup_ioctl(cmd);
1643 if (!fn) {
1644 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1645 return -ENOTTY;
1646 }
1647
1648 /*
1649 * Trying to avoid low memory issues when a device is
1650 * suspended.
1651 */
1652 current->flags |= PF_MEMALLOC;
1653
1654 /*
1655 * Copy the parameters into kernel space.
1656 */
1657 r = copy_params(user, ¶m);
1658
1659 current->flags &= ~PF_MEMALLOC;
1660
1661 if (r)
1662 return r;
1663
1664 input_param_size = param->data_size;
1665 wipe_buffer = param->flags & DM_SECURE_DATA_FLAG;
1666
1667 r = validate_params(cmd, param);
1668 if (r)
1669 goto out;
1670
1671 param->data_size = sizeof(*param);
1672 r = fn(param, input_param_size);
1673
1674 /*
1675 * Copy the results back to userland.
1676 */
1677 if (!r && copy_to_user(user, param, param->data_size))
1678 r = -EFAULT;
1679
1680out:
1681 if (wipe_buffer)
1682 memset(param, 0, input_param_size);
1683
1684 vfree(param);
1685 return r;
1686}
1687
1688static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
1689{
1690 return (long)ctl_ioctl(command, (struct dm_ioctl __user *)u);
1691}
1692
1693#ifdef CONFIG_COMPAT
1694static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
1695{
1696 return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
1697}
1698#else
1699#define dm_compat_ctl_ioctl NULL
1700#endif
1701
1702static const struct file_operations _ctl_fops = {
1703 .open = nonseekable_open,
1704 .unlocked_ioctl = dm_ctl_ioctl,
1705 .compat_ioctl = dm_compat_ctl_ioctl,
1706 .owner = THIS_MODULE,
1707 .llseek = noop_llseek,
1708};
1709
1710static struct miscdevice _dm_misc = {
1711 .minor = MAPPER_CTRL_MINOR,
1712 .name = DM_NAME,
1713 .nodename = DM_DIR "/" DM_CONTROL_NODE,
1714 .fops = &_ctl_fops
1715};
1716
1717MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
1718MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
1719
1720/*
1721 * Create misc character device and link to DM_DIR/control.
1722 */
1723int __init dm_interface_init(void)
1724{
1725 int r;
1726
1727 r = dm_hash_init();
1728 if (r)
1729 return r;
1730
1731 r = misc_register(&_dm_misc);
1732 if (r) {
1733 DMERR("misc_register failed for control device");
1734 dm_hash_exit();
1735 return r;
1736 }
1737
1738 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
1739 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
1740 DM_DRIVER_EMAIL);
1741 return 0;
1742}
1743
1744void dm_interface_exit(void)
1745{
1746 if (misc_deregister(&_dm_misc) < 0)
1747 DMERR("misc_deregister failed for control device");
1748
1749 dm_hash_exit();
1750}
1751
1752/**
1753 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
1754 * @md: Pointer to mapped_device
1755 * @name: Buffer (size DM_NAME_LEN) for name
1756 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
1757 */
1758int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
1759{
1760 int r = 0;
1761 struct hash_cell *hc;
1762
1763 if (!md)
1764 return -ENXIO;
1765
1766 mutex_lock(&dm_hash_cells_mutex);
1767 hc = dm_get_mdptr(md);
1768 if (!hc || hc->md != md) {
1769 r = -ENXIO;
1770 goto out;
1771 }
1772
1773 if (name)
1774 strcpy(name, hc->name);
1775 if (uuid)
1776 strcpy(uuid, hc->uuid ? : "");
1777
1778out:
1779 mutex_unlock(&dm_hash_cells_mutex);
1780
1781 return r;
1782}
1/*
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
39/*
40 * A dummy definition to make RCU happy.
41 * struct dm_table should never be dereferenced in this file.
42 */
43struct dm_table {
44 int undefined__;
45};
46
47struct vers_iter {
48 size_t param_size;
49 struct dm_target_versions *vers, *old_vers;
50 char *end;
51 uint32_t flags;
52};
53
54
55#define NUM_BUCKETS 64
56#define MASK_BUCKETS (NUM_BUCKETS - 1)
57static struct list_head _name_buckets[NUM_BUCKETS];
58static struct list_head _uuid_buckets[NUM_BUCKETS];
59
60static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred);
61
62/*
63 * Guards access to both hash tables.
64 */
65static DECLARE_RWSEM(_hash_lock);
66
67/*
68 * Protects use of mdptr to obtain hash cell name and uuid from mapped device.
69 */
70static DEFINE_MUTEX(dm_hash_cells_mutex);
71
72static void init_buckets(struct list_head *buckets)
73{
74 unsigned int i;
75
76 for (i = 0; i < NUM_BUCKETS; i++)
77 INIT_LIST_HEAD(buckets + i);
78}
79
80static int dm_hash_init(void)
81{
82 init_buckets(_name_buckets);
83 init_buckets(_uuid_buckets);
84 return 0;
85}
86
87static void dm_hash_exit(void)
88{
89 dm_hash_remove_all(false, false, false);
90}
91
92/*-----------------------------------------------------------------
93 * Hash function:
94 * We're not really concerned with the str hash function being
95 * fast since it's only used by the ioctl interface.
96 *---------------------------------------------------------------*/
97static unsigned int hash_str(const char *str)
98{
99 const unsigned int hash_mult = 2654435387U;
100 unsigned int h = 0;
101
102 while (*str)
103 h = (h + (unsigned int) *str++) * hash_mult;
104
105 return h & MASK_BUCKETS;
106}
107
108/*-----------------------------------------------------------------
109 * Code for looking up a device by name
110 *---------------------------------------------------------------*/
111static struct hash_cell *__get_name_cell(const char *str)
112{
113 struct hash_cell *hc;
114 unsigned int h = hash_str(str);
115
116 list_for_each_entry (hc, _name_buckets + h, name_list)
117 if (!strcmp(hc->name, str)) {
118 dm_get(hc->md);
119 return hc;
120 }
121
122 return NULL;
123}
124
125static struct hash_cell *__get_uuid_cell(const char *str)
126{
127 struct hash_cell *hc;
128 unsigned int h = hash_str(str);
129
130 list_for_each_entry (hc, _uuid_buckets + h, uuid_list)
131 if (!strcmp(hc->uuid, str)) {
132 dm_get(hc->md);
133 return hc;
134 }
135
136 return NULL;
137}
138
139static struct hash_cell *__get_dev_cell(uint64_t dev)
140{
141 struct mapped_device *md;
142 struct hash_cell *hc;
143
144 md = dm_get_md(huge_decode_dev(dev));
145 if (!md)
146 return NULL;
147
148 hc = dm_get_mdptr(md);
149 if (!hc) {
150 dm_put(md);
151 return NULL;
152 }
153
154 return hc;
155}
156
157/*-----------------------------------------------------------------
158 * Inserting, removing and renaming a device.
159 *---------------------------------------------------------------*/
160static struct hash_cell *alloc_cell(const char *name, const char *uuid,
161 struct mapped_device *md)
162{
163 struct hash_cell *hc;
164
165 hc = kmalloc(sizeof(*hc), GFP_KERNEL);
166 if (!hc)
167 return NULL;
168
169 hc->name = kstrdup(name, GFP_KERNEL);
170 if (!hc->name) {
171 kfree(hc);
172 return NULL;
173 }
174
175 if (!uuid)
176 hc->uuid = NULL;
177
178 else {
179 hc->uuid = kstrdup(uuid, GFP_KERNEL);
180 if (!hc->uuid) {
181 kfree(hc->name);
182 kfree(hc);
183 return NULL;
184 }
185 }
186
187 INIT_LIST_HEAD(&hc->name_list);
188 INIT_LIST_HEAD(&hc->uuid_list);
189 hc->md = md;
190 hc->new_map = NULL;
191 return hc;
192}
193
194static void free_cell(struct hash_cell *hc)
195{
196 if (hc) {
197 kfree(hc->name);
198 kfree(hc->uuid);
199 kfree(hc);
200 }
201}
202
203/*
204 * The kdev_t and uuid of a device can never change once it is
205 * initially inserted.
206 */
207static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
208{
209 struct hash_cell *cell, *hc;
210
211 /*
212 * Allocate the new cells.
213 */
214 cell = alloc_cell(name, uuid, md);
215 if (!cell)
216 return -ENOMEM;
217
218 /*
219 * Insert the cell into both hash tables.
220 */
221 down_write(&_hash_lock);
222 hc = __get_name_cell(name);
223 if (hc) {
224 dm_put(hc->md);
225 goto bad;
226 }
227
228 list_add(&cell->name_list, _name_buckets + hash_str(name));
229
230 if (uuid) {
231 hc = __get_uuid_cell(uuid);
232 if (hc) {
233 list_del(&cell->name_list);
234 dm_put(hc->md);
235 goto bad;
236 }
237 list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
238 }
239 dm_get(md);
240 mutex_lock(&dm_hash_cells_mutex);
241 dm_set_mdptr(md, cell);
242 mutex_unlock(&dm_hash_cells_mutex);
243 up_write(&_hash_lock);
244
245 return 0;
246
247 bad:
248 up_write(&_hash_lock);
249 free_cell(cell);
250 return -EBUSY;
251}
252
253static struct dm_table *__hash_remove(struct hash_cell *hc)
254{
255 struct dm_table *table;
256 int srcu_idx;
257
258 /* remove from the dev hash */
259 list_del(&hc->uuid_list);
260 list_del(&hc->name_list);
261 mutex_lock(&dm_hash_cells_mutex);
262 dm_set_mdptr(hc->md, NULL);
263 mutex_unlock(&dm_hash_cells_mutex);
264
265 table = dm_get_live_table(hc->md, &srcu_idx);
266 if (table)
267 dm_table_event(table);
268 dm_put_live_table(hc->md, srcu_idx);
269
270 table = NULL;
271 if (hc->new_map)
272 table = hc->new_map;
273 dm_put(hc->md);
274 free_cell(hc);
275
276 return table;
277}
278
279static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred)
280{
281 int i, dev_skipped;
282 struct hash_cell *hc;
283 struct mapped_device *md;
284 struct dm_table *t;
285
286retry:
287 dev_skipped = 0;
288
289 down_write(&_hash_lock);
290
291 for (i = 0; i < NUM_BUCKETS; i++) {
292 list_for_each_entry(hc, _name_buckets + i, name_list) {
293 md = hc->md;
294 dm_get(md);
295
296 if (keep_open_devices &&
297 dm_lock_for_deletion(md, mark_deferred, only_deferred)) {
298 dm_put(md);
299 dev_skipped++;
300 continue;
301 }
302
303 t = __hash_remove(hc);
304
305 up_write(&_hash_lock);
306
307 if (t) {
308 dm_sync_table(md);
309 dm_table_destroy(t);
310 }
311 dm_put(md);
312 if (likely(keep_open_devices))
313 dm_destroy(md);
314 else
315 dm_destroy_immediate(md);
316
317 /*
318 * Some mapped devices may be using other mapped
319 * devices, so repeat until we make no further
320 * progress. If a new mapped device is created
321 * here it will also get removed.
322 */
323 goto retry;
324 }
325 }
326
327 up_write(&_hash_lock);
328
329 if (dev_skipped)
330 DMWARN("remove_all left %d open device(s)", dev_skipped);
331}
332
333/*
334 * Set the uuid of a hash_cell that isn't already set.
335 */
336static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
337{
338 mutex_lock(&dm_hash_cells_mutex);
339 hc->uuid = new_uuid;
340 mutex_unlock(&dm_hash_cells_mutex);
341
342 list_add(&hc->uuid_list, _uuid_buckets + hash_str(new_uuid));
343}
344
345/*
346 * Changes the name of a hash_cell and returns the old name for
347 * the caller to free.
348 */
349static char *__change_cell_name(struct hash_cell *hc, char *new_name)
350{
351 char *old_name;
352
353 /*
354 * Rename and move the name cell.
355 */
356 list_del(&hc->name_list);
357 old_name = hc->name;
358
359 mutex_lock(&dm_hash_cells_mutex);
360 hc->name = new_name;
361 mutex_unlock(&dm_hash_cells_mutex);
362
363 list_add(&hc->name_list, _name_buckets + hash_str(new_name));
364
365 return old_name;
366}
367
368static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
369 const char *new)
370{
371 char *new_data, *old_name = NULL;
372 struct hash_cell *hc;
373 struct dm_table *table;
374 struct mapped_device *md;
375 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
376 int srcu_idx;
377
378 /*
379 * duplicate new.
380 */
381 new_data = kstrdup(new, GFP_KERNEL);
382 if (!new_data)
383 return ERR_PTR(-ENOMEM);
384
385 down_write(&_hash_lock);
386
387 /*
388 * Is new free ?
389 */
390 if (change_uuid)
391 hc = __get_uuid_cell(new);
392 else
393 hc = __get_name_cell(new);
394
395 if (hc) {
396 DMWARN("Unable to change %s on mapped device %s to one that "
397 "already exists: %s",
398 change_uuid ? "uuid" : "name",
399 param->name, new);
400 dm_put(hc->md);
401 up_write(&_hash_lock);
402 kfree(new_data);
403 return ERR_PTR(-EBUSY);
404 }
405
406 /*
407 * Is there such a device as 'old' ?
408 */
409 hc = __get_name_cell(param->name);
410 if (!hc) {
411 DMWARN("Unable to rename non-existent device, %s to %s%s",
412 param->name, change_uuid ? "uuid " : "", new);
413 up_write(&_hash_lock);
414 kfree(new_data);
415 return ERR_PTR(-ENXIO);
416 }
417
418 /*
419 * Does this device already have a uuid?
420 */
421 if (change_uuid && hc->uuid) {
422 DMWARN("Unable to change uuid of mapped device %s to %s "
423 "because uuid is already set to %s",
424 param->name, new, hc->uuid);
425 dm_put(hc->md);
426 up_write(&_hash_lock);
427 kfree(new_data);
428 return ERR_PTR(-EINVAL);
429 }
430
431 if (change_uuid)
432 __set_cell_uuid(hc, new_data);
433 else
434 old_name = __change_cell_name(hc, new_data);
435
436 /*
437 * Wake up any dm event waiters.
438 */
439 table = dm_get_live_table(hc->md, &srcu_idx);
440 if (table)
441 dm_table_event(table);
442 dm_put_live_table(hc->md, srcu_idx);
443
444 if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr))
445 param->flags |= DM_UEVENT_GENERATED_FLAG;
446
447 md = hc->md;
448 up_write(&_hash_lock);
449 kfree(old_name);
450
451 return md;
452}
453
454void dm_deferred_remove(void)
455{
456 dm_hash_remove_all(true, false, true);
457}
458
459/*-----------------------------------------------------------------
460 * Implementation of the ioctl commands
461 *---------------------------------------------------------------*/
462/*
463 * All the ioctl commands get dispatched to functions with this
464 * prototype.
465 */
466typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size);
467
468static int remove_all(struct dm_ioctl *param, size_t param_size)
469{
470 dm_hash_remove_all(true, !!(param->flags & DM_DEFERRED_REMOVE), false);
471 param->data_size = 0;
472 return 0;
473}
474
475/*
476 * Round up the ptr to an 8-byte boundary.
477 */
478#define ALIGN_MASK 7
479static inline void *align_ptr(void *ptr)
480{
481 return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK);
482}
483
484/*
485 * Retrieves the data payload buffer from an already allocated
486 * struct dm_ioctl.
487 */
488static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
489 size_t *len)
490{
491 param->data_start = align_ptr(param + 1) - (void *) param;
492
493 if (param->data_start < param_size)
494 *len = param_size - param->data_start;
495 else
496 *len = 0;
497
498 return ((void *) param) + param->data_start;
499}
500
501static int list_devices(struct dm_ioctl *param, size_t param_size)
502{
503 unsigned int i;
504 struct hash_cell *hc;
505 size_t len, needed = 0;
506 struct gendisk *disk;
507 struct dm_name_list *nl, *old_nl = NULL;
508
509 down_write(&_hash_lock);
510
511 /*
512 * Loop through all the devices working out how much
513 * space we need.
514 */
515 for (i = 0; i < NUM_BUCKETS; i++) {
516 list_for_each_entry (hc, _name_buckets + i, name_list) {
517 needed += sizeof(struct dm_name_list);
518 needed += strlen(hc->name) + 1;
519 needed += ALIGN_MASK;
520 }
521 }
522
523 /*
524 * Grab our output buffer.
525 */
526 nl = get_result_buffer(param, param_size, &len);
527 if (len < needed) {
528 param->flags |= DM_BUFFER_FULL_FLAG;
529 goto out;
530 }
531 param->data_size = param->data_start + needed;
532
533 nl->dev = 0; /* Flags no data */
534
535 /*
536 * Now loop through filling out the names.
537 */
538 for (i = 0; i < NUM_BUCKETS; i++) {
539 list_for_each_entry (hc, _name_buckets + i, name_list) {
540 if (old_nl)
541 old_nl->next = (uint32_t) ((void *) nl -
542 (void *) old_nl);
543 disk = dm_disk(hc->md);
544 nl->dev = huge_encode_dev(disk_devt(disk));
545 nl->next = 0;
546 strcpy(nl->name, hc->name);
547
548 old_nl = nl;
549 nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1);
550 }
551 }
552
553 out:
554 up_write(&_hash_lock);
555 return 0;
556}
557
558static void list_version_get_needed(struct target_type *tt, void *needed_param)
559{
560 size_t *needed = needed_param;
561
562 *needed += sizeof(struct dm_target_versions);
563 *needed += strlen(tt->name);
564 *needed += ALIGN_MASK;
565}
566
567static void list_version_get_info(struct target_type *tt, void *param)
568{
569 struct vers_iter *info = param;
570
571 /* Check space - it might have changed since the first iteration */
572 if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
573 info->end) {
574
575 info->flags = DM_BUFFER_FULL_FLAG;
576 return;
577 }
578
579 if (info->old_vers)
580 info->old_vers->next = (uint32_t) ((void *)info->vers -
581 (void *)info->old_vers);
582 info->vers->version[0] = tt->version[0];
583 info->vers->version[1] = tt->version[1];
584 info->vers->version[2] = tt->version[2];
585 info->vers->next = 0;
586 strcpy(info->vers->name, tt->name);
587
588 info->old_vers = info->vers;
589 info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
590}
591
592static int list_versions(struct dm_ioctl *param, size_t param_size)
593{
594 size_t len, needed = 0;
595 struct dm_target_versions *vers;
596 struct vers_iter iter_info;
597
598 /*
599 * Loop through all the devices working out how much
600 * space we need.
601 */
602 dm_target_iterate(list_version_get_needed, &needed);
603
604 /*
605 * Grab our output buffer.
606 */
607 vers = get_result_buffer(param, param_size, &len);
608 if (len < needed) {
609 param->flags |= DM_BUFFER_FULL_FLAG;
610 goto out;
611 }
612 param->data_size = param->data_start + needed;
613
614 iter_info.param_size = param_size;
615 iter_info.old_vers = NULL;
616 iter_info.vers = vers;
617 iter_info.flags = 0;
618 iter_info.end = (char *)vers+len;
619
620 /*
621 * Now loop through filling out the names & versions.
622 */
623 dm_target_iterate(list_version_get_info, &iter_info);
624 param->flags |= iter_info.flags;
625
626 out:
627 return 0;
628}
629
630static int check_name(const char *name)
631{
632 if (strchr(name, '/')) {
633 DMWARN("invalid device name");
634 return -EINVAL;
635 }
636
637 return 0;
638}
639
640/*
641 * On successful return, the caller must not attempt to acquire
642 * _hash_lock without first calling dm_table_put, because dm_table_destroy
643 * waits for this dm_table_put and could be called under this lock.
644 */
645static struct dm_table *dm_get_inactive_table(struct mapped_device *md, int *srcu_idx)
646{
647 struct hash_cell *hc;
648 struct dm_table *table = NULL;
649
650 /* increment rcu count, we don't care about the table pointer */
651 dm_get_live_table(md, srcu_idx);
652
653 down_read(&_hash_lock);
654 hc = dm_get_mdptr(md);
655 if (!hc || hc->md != md) {
656 DMWARN("device has been removed from the dev hash table.");
657 goto out;
658 }
659
660 table = hc->new_map;
661
662out:
663 up_read(&_hash_lock);
664
665 return table;
666}
667
668static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
669 struct dm_ioctl *param,
670 int *srcu_idx)
671{
672 return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
673 dm_get_inactive_table(md, srcu_idx) : dm_get_live_table(md, srcu_idx);
674}
675
676/*
677 * Fills in a dm_ioctl structure, ready for sending back to
678 * userland.
679 */
680static void __dev_status(struct mapped_device *md, struct dm_ioctl *param)
681{
682 struct gendisk *disk = dm_disk(md);
683 struct dm_table *table;
684 int srcu_idx;
685
686 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
687 DM_ACTIVE_PRESENT_FLAG);
688
689 if (dm_suspended_md(md))
690 param->flags |= DM_SUSPEND_FLAG;
691
692 if (dm_test_deferred_remove_flag(md))
693 param->flags |= DM_DEFERRED_REMOVE;
694
695 param->dev = huge_encode_dev(disk_devt(disk));
696
697 /*
698 * Yes, this will be out of date by the time it gets back
699 * to userland, but it is still very useful for
700 * debugging.
701 */
702 param->open_count = dm_open_count(md);
703
704 param->event_nr = dm_get_event_nr(md);
705 param->target_count = 0;
706
707 table = dm_get_live_table(md, &srcu_idx);
708 if (table) {
709 if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
710 if (get_disk_ro(disk))
711 param->flags |= DM_READONLY_FLAG;
712 param->target_count = dm_table_get_num_targets(table);
713 }
714
715 param->flags |= DM_ACTIVE_PRESENT_FLAG;
716 }
717 dm_put_live_table(md, srcu_idx);
718
719 if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
720 int srcu_idx;
721 table = dm_get_inactive_table(md, &srcu_idx);
722 if (table) {
723 if (!(dm_table_get_mode(table) & FMODE_WRITE))
724 param->flags |= DM_READONLY_FLAG;
725 param->target_count = dm_table_get_num_targets(table);
726 }
727 dm_put_live_table(md, srcu_idx);
728 }
729}
730
731static int dev_create(struct dm_ioctl *param, size_t param_size)
732{
733 int r, m = DM_ANY_MINOR;
734 struct mapped_device *md;
735
736 r = check_name(param->name);
737 if (r)
738 return r;
739
740 if (param->flags & DM_PERSISTENT_DEV_FLAG)
741 m = MINOR(huge_decode_dev(param->dev));
742
743 r = dm_create(m, &md);
744 if (r)
745 return r;
746
747 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
748 if (r) {
749 dm_put(md);
750 dm_destroy(md);
751 return r;
752 }
753
754 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
755
756 __dev_status(md, param);
757
758 dm_put(md);
759
760 return 0;
761}
762
763/*
764 * Always use UUID for lookups if it's present, otherwise use name or dev.
765 */
766static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
767{
768 struct hash_cell *hc = NULL;
769
770 if (*param->uuid) {
771 if (*param->name || param->dev)
772 return NULL;
773
774 hc = __get_uuid_cell(param->uuid);
775 if (!hc)
776 return NULL;
777 } else if (*param->name) {
778 if (param->dev)
779 return NULL;
780
781 hc = __get_name_cell(param->name);
782 if (!hc)
783 return NULL;
784 } else if (param->dev) {
785 hc = __get_dev_cell(param->dev);
786 if (!hc)
787 return NULL;
788 } else
789 return NULL;
790
791 /*
792 * Sneakily write in both the name and the uuid
793 * while we have the cell.
794 */
795 strlcpy(param->name, hc->name, sizeof(param->name));
796 if (hc->uuid)
797 strlcpy(param->uuid, hc->uuid, sizeof(param->uuid));
798 else
799 param->uuid[0] = '\0';
800
801 if (hc->new_map)
802 param->flags |= DM_INACTIVE_PRESENT_FLAG;
803 else
804 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
805
806 return hc;
807}
808
809static struct mapped_device *find_device(struct dm_ioctl *param)
810{
811 struct hash_cell *hc;
812 struct mapped_device *md = NULL;
813
814 down_read(&_hash_lock);
815 hc = __find_device_hash_cell(param);
816 if (hc)
817 md = hc->md;
818 up_read(&_hash_lock);
819
820 return md;
821}
822
823static int dev_remove(struct dm_ioctl *param, size_t param_size)
824{
825 struct hash_cell *hc;
826 struct mapped_device *md;
827 int r;
828 struct dm_table *t;
829
830 down_write(&_hash_lock);
831 hc = __find_device_hash_cell(param);
832
833 if (!hc) {
834 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
835 up_write(&_hash_lock);
836 return -ENXIO;
837 }
838
839 md = hc->md;
840
841 /*
842 * Ensure the device is not open and nothing further can open it.
843 */
844 r = dm_lock_for_deletion(md, !!(param->flags & DM_DEFERRED_REMOVE), false);
845 if (r) {
846 if (r == -EBUSY && param->flags & DM_DEFERRED_REMOVE) {
847 up_write(&_hash_lock);
848 dm_put(md);
849 return 0;
850 }
851 DMDEBUG_LIMIT("unable to remove open device %s", hc->name);
852 up_write(&_hash_lock);
853 dm_put(md);
854 return r;
855 }
856
857 t = __hash_remove(hc);
858 up_write(&_hash_lock);
859
860 if (t) {
861 dm_sync_table(md);
862 dm_table_destroy(t);
863 }
864
865 param->flags &= ~DM_DEFERRED_REMOVE;
866
867 if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr))
868 param->flags |= DM_UEVENT_GENERATED_FLAG;
869
870 dm_put(md);
871 dm_destroy(md);
872 return 0;
873}
874
875/*
876 * Check a string doesn't overrun the chunk of
877 * memory we copied from userland.
878 */
879static int invalid_str(char *str, void *end)
880{
881 while ((void *) str < end)
882 if (!*str++)
883 return 0;
884
885 return -EINVAL;
886}
887
888static int dev_rename(struct dm_ioctl *param, size_t param_size)
889{
890 int r;
891 char *new_data = (char *) param + param->data_start;
892 struct mapped_device *md;
893 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
894
895 if (new_data < param->data ||
896 invalid_str(new_data, (void *) param + param_size) || !*new_data ||
897 strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
898 DMWARN("Invalid new mapped device name or uuid string supplied.");
899 return -EINVAL;
900 }
901
902 if (!change_uuid) {
903 r = check_name(new_data);
904 if (r)
905 return r;
906 }
907
908 md = dm_hash_rename(param, new_data);
909 if (IS_ERR(md))
910 return PTR_ERR(md);
911
912 __dev_status(md, param);
913 dm_put(md);
914
915 return 0;
916}
917
918static int dev_set_geometry(struct dm_ioctl *param, size_t param_size)
919{
920 int r = -EINVAL, x;
921 struct mapped_device *md;
922 struct hd_geometry geometry;
923 unsigned long indata[4];
924 char *geostr = (char *) param + param->data_start;
925 char dummy;
926
927 md = find_device(param);
928 if (!md)
929 return -ENXIO;
930
931 if (geostr < param->data ||
932 invalid_str(geostr, (void *) param + param_size)) {
933 DMWARN("Invalid geometry supplied.");
934 goto out;
935 }
936
937 x = sscanf(geostr, "%lu %lu %lu %lu%c", indata,
938 indata + 1, indata + 2, indata + 3, &dummy);
939
940 if (x != 4) {
941 DMWARN("Unable to interpret geometry settings.");
942 goto out;
943 }
944
945 if (indata[0] > 65535 || indata[1] > 255 ||
946 indata[2] > 255 || indata[3] > ULONG_MAX) {
947 DMWARN("Geometry exceeds range limits.");
948 goto out;
949 }
950
951 geometry.cylinders = indata[0];
952 geometry.heads = indata[1];
953 geometry.sectors = indata[2];
954 geometry.start = indata[3];
955
956 r = dm_set_geometry(md, &geometry);
957
958 param->data_size = 0;
959
960out:
961 dm_put(md);
962 return r;
963}
964
965static int do_suspend(struct dm_ioctl *param)
966{
967 int r = 0;
968 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
969 struct mapped_device *md;
970
971 md = find_device(param);
972 if (!md)
973 return -ENXIO;
974
975 if (param->flags & DM_SKIP_LOCKFS_FLAG)
976 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
977 if (param->flags & DM_NOFLUSH_FLAG)
978 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
979
980 if (!dm_suspended_md(md)) {
981 r = dm_suspend(md, suspend_flags);
982 if (r)
983 goto out;
984 }
985
986 __dev_status(md, param);
987
988out:
989 dm_put(md);
990
991 return r;
992}
993
994static int do_resume(struct dm_ioctl *param)
995{
996 int r = 0;
997 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
998 struct hash_cell *hc;
999 struct mapped_device *md;
1000 struct dm_table *new_map, *old_map = NULL;
1001
1002 down_write(&_hash_lock);
1003
1004 hc = __find_device_hash_cell(param);
1005 if (!hc) {
1006 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1007 up_write(&_hash_lock);
1008 return -ENXIO;
1009 }
1010
1011 md = hc->md;
1012
1013 new_map = hc->new_map;
1014 hc->new_map = NULL;
1015 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1016
1017 up_write(&_hash_lock);
1018
1019 /* Do we need to load a new map ? */
1020 if (new_map) {
1021 /* Suspend if it isn't already suspended */
1022 if (param->flags & DM_SKIP_LOCKFS_FLAG)
1023 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
1024 if (param->flags & DM_NOFLUSH_FLAG)
1025 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
1026 if (!dm_suspended_md(md))
1027 dm_suspend(md, suspend_flags);
1028
1029 old_map = dm_swap_table(md, new_map);
1030 if (IS_ERR(old_map)) {
1031 dm_sync_table(md);
1032 dm_table_destroy(new_map);
1033 dm_put(md);
1034 return PTR_ERR(old_map);
1035 }
1036
1037 if (dm_table_get_mode(new_map) & FMODE_WRITE)
1038 set_disk_ro(dm_disk(md), 0);
1039 else
1040 set_disk_ro(dm_disk(md), 1);
1041 }
1042
1043 if (dm_suspended_md(md)) {
1044 r = dm_resume(md);
1045 if (!r && !dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr))
1046 param->flags |= DM_UEVENT_GENERATED_FLAG;
1047 }
1048
1049 /*
1050 * Since dm_swap_table synchronizes RCU, nobody should be in
1051 * read-side critical section already.
1052 */
1053 if (old_map)
1054 dm_table_destroy(old_map);
1055
1056 if (!r)
1057 __dev_status(md, param);
1058
1059 dm_put(md);
1060 return r;
1061}
1062
1063/*
1064 * Set or unset the suspension state of a device.
1065 * If the device already is in the requested state we just return its status.
1066 */
1067static int dev_suspend(struct dm_ioctl *param, size_t param_size)
1068{
1069 if (param->flags & DM_SUSPEND_FLAG)
1070 return do_suspend(param);
1071
1072 return do_resume(param);
1073}
1074
1075/*
1076 * Copies device info back to user space, used by
1077 * the create and info ioctls.
1078 */
1079static int dev_status(struct dm_ioctl *param, size_t param_size)
1080{
1081 struct mapped_device *md;
1082
1083 md = find_device(param);
1084 if (!md)
1085 return -ENXIO;
1086
1087 __dev_status(md, param);
1088 dm_put(md);
1089
1090 return 0;
1091}
1092
1093/*
1094 * Build up the status struct for each target
1095 */
1096static void retrieve_status(struct dm_table *table,
1097 struct dm_ioctl *param, size_t param_size)
1098{
1099 unsigned int i, num_targets;
1100 struct dm_target_spec *spec;
1101 char *outbuf, *outptr;
1102 status_type_t type;
1103 size_t remaining, len, used = 0;
1104 unsigned status_flags = 0;
1105
1106 outptr = outbuf = get_result_buffer(param, param_size, &len);
1107
1108 if (param->flags & DM_STATUS_TABLE_FLAG)
1109 type = STATUSTYPE_TABLE;
1110 else
1111 type = STATUSTYPE_INFO;
1112
1113 /* Get all the target info */
1114 num_targets = dm_table_get_num_targets(table);
1115 for (i = 0; i < num_targets; i++) {
1116 struct dm_target *ti = dm_table_get_target(table, i);
1117 size_t l;
1118
1119 remaining = len - (outptr - outbuf);
1120 if (remaining <= sizeof(struct dm_target_spec)) {
1121 param->flags |= DM_BUFFER_FULL_FLAG;
1122 break;
1123 }
1124
1125 spec = (struct dm_target_spec *) outptr;
1126
1127 spec->status = 0;
1128 spec->sector_start = ti->begin;
1129 spec->length = ti->len;
1130 strncpy(spec->target_type, ti->type->name,
1131 sizeof(spec->target_type));
1132
1133 outptr += sizeof(struct dm_target_spec);
1134 remaining = len - (outptr - outbuf);
1135 if (remaining <= 0) {
1136 param->flags |= DM_BUFFER_FULL_FLAG;
1137 break;
1138 }
1139
1140 /* Get the status/table string from the target driver */
1141 if (ti->type->status) {
1142 if (param->flags & DM_NOFLUSH_FLAG)
1143 status_flags |= DM_STATUS_NOFLUSH_FLAG;
1144 ti->type->status(ti, type, status_flags, outptr, remaining);
1145 } else
1146 outptr[0] = '\0';
1147
1148 l = strlen(outptr) + 1;
1149 if (l == remaining) {
1150 param->flags |= DM_BUFFER_FULL_FLAG;
1151 break;
1152 }
1153
1154 outptr += l;
1155 used = param->data_start + (outptr - outbuf);
1156
1157 outptr = align_ptr(outptr);
1158 spec->next = outptr - outbuf;
1159 }
1160
1161 if (used)
1162 param->data_size = used;
1163
1164 param->target_count = num_targets;
1165}
1166
1167/*
1168 * Wait for a device to report an event
1169 */
1170static int dev_wait(struct dm_ioctl *param, size_t param_size)
1171{
1172 int r = 0;
1173 struct mapped_device *md;
1174 struct dm_table *table;
1175 int srcu_idx;
1176
1177 md = find_device(param);
1178 if (!md)
1179 return -ENXIO;
1180
1181 /*
1182 * Wait for a notification event
1183 */
1184 if (dm_wait_event(md, param->event_nr)) {
1185 r = -ERESTARTSYS;
1186 goto out;
1187 }
1188
1189 /*
1190 * The userland program is going to want to know what
1191 * changed to trigger the event, so we may as well tell
1192 * him and save an ioctl.
1193 */
1194 __dev_status(md, param);
1195
1196 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1197 if (table)
1198 retrieve_status(table, param, param_size);
1199 dm_put_live_table(md, srcu_idx);
1200
1201out:
1202 dm_put(md);
1203
1204 return r;
1205}
1206
1207static inline fmode_t get_mode(struct dm_ioctl *param)
1208{
1209 fmode_t mode = FMODE_READ | FMODE_WRITE;
1210
1211 if (param->flags & DM_READONLY_FLAG)
1212 mode = FMODE_READ;
1213
1214 return mode;
1215}
1216
1217static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
1218 struct dm_target_spec **spec, char **target_params)
1219{
1220 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1221 *target_params = (char *) (*spec + 1);
1222
1223 if (*spec < (last + 1))
1224 return -EINVAL;
1225
1226 return invalid_str(*target_params, end);
1227}
1228
1229static int populate_table(struct dm_table *table,
1230 struct dm_ioctl *param, size_t param_size)
1231{
1232 int r;
1233 unsigned int i = 0;
1234 struct dm_target_spec *spec = (struct dm_target_spec *) param;
1235 uint32_t next = param->data_start;
1236 void *end = (void *) param + param_size;
1237 char *target_params;
1238
1239 if (!param->target_count) {
1240 DMWARN("populate_table: no targets specified");
1241 return -EINVAL;
1242 }
1243
1244 for (i = 0; i < param->target_count; i++) {
1245
1246 r = next_target(spec, next, end, &spec, &target_params);
1247 if (r) {
1248 DMWARN("unable to find target");
1249 return r;
1250 }
1251
1252 r = dm_table_add_target(table, spec->target_type,
1253 (sector_t) spec->sector_start,
1254 (sector_t) spec->length,
1255 target_params);
1256 if (r) {
1257 DMWARN("error adding target to table");
1258 return r;
1259 }
1260
1261 next = spec->next;
1262 }
1263
1264 return dm_table_complete(table);
1265}
1266
1267static int table_load(struct dm_ioctl *param, size_t param_size)
1268{
1269 int r;
1270 struct hash_cell *hc;
1271 struct dm_table *t, *old_map = NULL;
1272 struct mapped_device *md;
1273 struct target_type *immutable_target_type;
1274
1275 md = find_device(param);
1276 if (!md)
1277 return -ENXIO;
1278
1279 r = dm_table_create(&t, get_mode(param), param->target_count, md);
1280 if (r)
1281 goto err;
1282
1283 /* Protect md->type and md->queue against concurrent table loads. */
1284 dm_lock_md_type(md);
1285 r = populate_table(t, param, param_size);
1286 if (r)
1287 goto err_unlock_md_type;
1288
1289 immutable_target_type = dm_get_immutable_target_type(md);
1290 if (immutable_target_type &&
1291 (immutable_target_type != dm_table_get_immutable_target_type(t))) {
1292 DMWARN("can't replace immutable target type %s",
1293 immutable_target_type->name);
1294 r = -EINVAL;
1295 goto err_unlock_md_type;
1296 }
1297
1298 if (dm_get_md_type(md) == DM_TYPE_NONE)
1299 /* Initial table load: acquire type of table. */
1300 dm_set_md_type(md, dm_table_get_type(t));
1301 else if (dm_get_md_type(md) != dm_table_get_type(t)) {
1302 DMWARN("can't change device type after initial table load.");
1303 r = -EINVAL;
1304 goto err_unlock_md_type;
1305 }
1306
1307 /* setup md->queue to reflect md's type (may block) */
1308 r = dm_setup_md_queue(md);
1309 if (r) {
1310 DMWARN("unable to set up device queue for new table.");
1311 goto err_unlock_md_type;
1312 }
1313 dm_unlock_md_type(md);
1314
1315 /* stage inactive table */
1316 down_write(&_hash_lock);
1317 hc = dm_get_mdptr(md);
1318 if (!hc || hc->md != md) {
1319 DMWARN("device has been removed from the dev hash table.");
1320 up_write(&_hash_lock);
1321 r = -ENXIO;
1322 goto err_destroy_table;
1323 }
1324
1325 if (hc->new_map)
1326 old_map = hc->new_map;
1327 hc->new_map = t;
1328 up_write(&_hash_lock);
1329
1330 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1331 __dev_status(md, param);
1332
1333 if (old_map) {
1334 dm_sync_table(md);
1335 dm_table_destroy(old_map);
1336 }
1337
1338 dm_put(md);
1339
1340 return 0;
1341
1342err_unlock_md_type:
1343 dm_unlock_md_type(md);
1344err_destroy_table:
1345 dm_table_destroy(t);
1346err:
1347 dm_put(md);
1348
1349 return r;
1350}
1351
1352static int table_clear(struct dm_ioctl *param, size_t param_size)
1353{
1354 struct hash_cell *hc;
1355 struct mapped_device *md;
1356 struct dm_table *old_map = NULL;
1357
1358 down_write(&_hash_lock);
1359
1360 hc = __find_device_hash_cell(param);
1361 if (!hc) {
1362 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1363 up_write(&_hash_lock);
1364 return -ENXIO;
1365 }
1366
1367 if (hc->new_map) {
1368 old_map = hc->new_map;
1369 hc->new_map = NULL;
1370 }
1371
1372 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1373
1374 __dev_status(hc->md, param);
1375 md = hc->md;
1376 up_write(&_hash_lock);
1377 if (old_map) {
1378 dm_sync_table(md);
1379 dm_table_destroy(old_map);
1380 }
1381 dm_put(md);
1382
1383 return 0;
1384}
1385
1386/*
1387 * Retrieves a list of devices used by a particular dm device.
1388 */
1389static void retrieve_deps(struct dm_table *table,
1390 struct dm_ioctl *param, size_t param_size)
1391{
1392 unsigned int count = 0;
1393 struct list_head *tmp;
1394 size_t len, needed;
1395 struct dm_dev_internal *dd;
1396 struct dm_target_deps *deps;
1397
1398 deps = get_result_buffer(param, param_size, &len);
1399
1400 /*
1401 * Count the devices.
1402 */
1403 list_for_each (tmp, dm_table_get_devices(table))
1404 count++;
1405
1406 /*
1407 * Check we have enough space.
1408 */
1409 needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
1410 if (len < needed) {
1411 param->flags |= DM_BUFFER_FULL_FLAG;
1412 return;
1413 }
1414
1415 /*
1416 * Fill in the devices.
1417 */
1418 deps->count = count;
1419 count = 0;
1420 list_for_each_entry (dd, dm_table_get_devices(table), list)
1421 deps->dev[count++] = huge_encode_dev(dd->dm_dev.bdev->bd_dev);
1422
1423 param->data_size = param->data_start + needed;
1424}
1425
1426static int table_deps(struct dm_ioctl *param, size_t param_size)
1427{
1428 struct mapped_device *md;
1429 struct dm_table *table;
1430 int srcu_idx;
1431
1432 md = find_device(param);
1433 if (!md)
1434 return -ENXIO;
1435
1436 __dev_status(md, param);
1437
1438 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1439 if (table)
1440 retrieve_deps(table, param, param_size);
1441 dm_put_live_table(md, srcu_idx);
1442
1443 dm_put(md);
1444
1445 return 0;
1446}
1447
1448/*
1449 * Return the status of a device as a text string for each
1450 * target.
1451 */
1452static int table_status(struct dm_ioctl *param, size_t param_size)
1453{
1454 struct mapped_device *md;
1455 struct dm_table *table;
1456 int srcu_idx;
1457
1458 md = find_device(param);
1459 if (!md)
1460 return -ENXIO;
1461
1462 __dev_status(md, param);
1463
1464 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1465 if (table)
1466 retrieve_status(table, param, param_size);
1467 dm_put_live_table(md, srcu_idx);
1468
1469 dm_put(md);
1470
1471 return 0;
1472}
1473
1474/*
1475 * Process device-mapper dependent messages. Messages prefixed with '@'
1476 * are processed by the DM core. All others are delivered to the target.
1477 * Returns a number <= 1 if message was processed by device mapper.
1478 * Returns 2 if message should be delivered to the target.
1479 */
1480static int message_for_md(struct mapped_device *md, unsigned argc, char **argv,
1481 char *result, unsigned maxlen)
1482{
1483 int r;
1484
1485 if (**argv != '@')
1486 return 2; /* no '@' prefix, deliver to target */
1487
1488 if (!strcasecmp(argv[0], "@cancel_deferred_remove")) {
1489 if (argc != 1) {
1490 DMERR("Invalid arguments for @cancel_deferred_remove");
1491 return -EINVAL;
1492 }
1493 return dm_cancel_deferred_remove(md);
1494 }
1495
1496 r = dm_stats_message(md, argc, argv, result, maxlen);
1497 if (r < 2)
1498 return r;
1499
1500 DMERR("Unsupported message sent to DM core: %s", argv[0]);
1501 return -EINVAL;
1502}
1503
1504/*
1505 * Pass a message to the target that's at the supplied device offset.
1506 */
1507static int target_message(struct dm_ioctl *param, size_t param_size)
1508{
1509 int r, argc;
1510 char **argv;
1511 struct mapped_device *md;
1512 struct dm_table *table;
1513 struct dm_target *ti;
1514 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1515 size_t maxlen;
1516 char *result = get_result_buffer(param, param_size, &maxlen);
1517 int srcu_idx;
1518
1519 md = find_device(param);
1520 if (!md)
1521 return -ENXIO;
1522
1523 if (tmsg < (struct dm_target_msg *) param->data ||
1524 invalid_str(tmsg->message, (void *) param + param_size)) {
1525 DMWARN("Invalid target message parameters.");
1526 r = -EINVAL;
1527 goto out;
1528 }
1529
1530 r = dm_split_args(&argc, &argv, tmsg->message);
1531 if (r) {
1532 DMWARN("Failed to split target message parameters");
1533 goto out;
1534 }
1535
1536 if (!argc) {
1537 DMWARN("Empty message received.");
1538 goto out_argv;
1539 }
1540
1541 r = message_for_md(md, argc, argv, result, maxlen);
1542 if (r <= 1)
1543 goto out_argv;
1544
1545 table = dm_get_live_table(md, &srcu_idx);
1546 if (!table)
1547 goto out_table;
1548
1549 if (dm_deleting_md(md)) {
1550 r = -ENXIO;
1551 goto out_table;
1552 }
1553
1554 ti = dm_table_find_target(table, tmsg->sector);
1555 if (!dm_target_is_valid(ti)) {
1556 DMWARN("Target message sector outside device.");
1557 r = -EINVAL;
1558 } else if (ti->type->message)
1559 r = ti->type->message(ti, argc, argv);
1560 else {
1561 DMWARN("Target type does not support messages");
1562 r = -EINVAL;
1563 }
1564
1565 out_table:
1566 dm_put_live_table(md, srcu_idx);
1567 out_argv:
1568 kfree(argv);
1569 out:
1570 if (r >= 0)
1571 __dev_status(md, param);
1572
1573 if (r == 1) {
1574 param->flags |= DM_DATA_OUT_FLAG;
1575 if (dm_message_test_buffer_overflow(result, maxlen))
1576 param->flags |= DM_BUFFER_FULL_FLAG;
1577 else
1578 param->data_size = param->data_start + strlen(result) + 1;
1579 r = 0;
1580 }
1581
1582 dm_put(md);
1583 return r;
1584}
1585
1586/*
1587 * The ioctl parameter block consists of two parts, a dm_ioctl struct
1588 * followed by a data buffer. This flag is set if the second part,
1589 * which has a variable size, is not used by the function processing
1590 * the ioctl.
1591 */
1592#define IOCTL_FLAGS_NO_PARAMS 1
1593
1594/*-----------------------------------------------------------------
1595 * Implementation of open/close/ioctl on the special char
1596 * device.
1597 *---------------------------------------------------------------*/
1598static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags)
1599{
1600 static struct {
1601 int cmd;
1602 int flags;
1603 ioctl_fn fn;
1604 } _ioctls[] = {
1605 {DM_VERSION_CMD, 0, NULL}, /* version is dealt with elsewhere */
1606 {DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS, remove_all},
1607 {DM_LIST_DEVICES_CMD, 0, list_devices},
1608
1609 {DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS, dev_create},
1610 {DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS, dev_remove},
1611 {DM_DEV_RENAME_CMD, 0, dev_rename},
1612 {DM_DEV_SUSPEND_CMD, IOCTL_FLAGS_NO_PARAMS, dev_suspend},
1613 {DM_DEV_STATUS_CMD, IOCTL_FLAGS_NO_PARAMS, dev_status},
1614 {DM_DEV_WAIT_CMD, 0, dev_wait},
1615
1616 {DM_TABLE_LOAD_CMD, 0, table_load},
1617 {DM_TABLE_CLEAR_CMD, IOCTL_FLAGS_NO_PARAMS, table_clear},
1618 {DM_TABLE_DEPS_CMD, 0, table_deps},
1619 {DM_TABLE_STATUS_CMD, 0, table_status},
1620
1621 {DM_LIST_VERSIONS_CMD, 0, list_versions},
1622
1623 {DM_TARGET_MSG_CMD, 0, target_message},
1624 {DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry}
1625 };
1626
1627 if (unlikely(cmd >= ARRAY_SIZE(_ioctls)))
1628 return NULL;
1629
1630 *ioctl_flags = _ioctls[cmd].flags;
1631 return _ioctls[cmd].fn;
1632}
1633
1634/*
1635 * As well as checking the version compatibility this always
1636 * copies the kernel interface version out.
1637 */
1638static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1639{
1640 uint32_t version[3];
1641 int r = 0;
1642
1643 if (copy_from_user(version, user->version, sizeof(version)))
1644 return -EFAULT;
1645
1646 if ((DM_VERSION_MAJOR != version[0]) ||
1647 (DM_VERSION_MINOR < version[1])) {
1648 DMWARN("ioctl interface mismatch: "
1649 "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1650 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1651 DM_VERSION_PATCHLEVEL,
1652 version[0], version[1], version[2], cmd);
1653 r = -EINVAL;
1654 }
1655
1656 /*
1657 * Fill in the kernel version.
1658 */
1659 version[0] = DM_VERSION_MAJOR;
1660 version[1] = DM_VERSION_MINOR;
1661 version[2] = DM_VERSION_PATCHLEVEL;
1662 if (copy_to_user(user->version, version, sizeof(version)))
1663 return -EFAULT;
1664
1665 return r;
1666}
1667
1668#define DM_PARAMS_KMALLOC 0x0001 /* Params alloced with kmalloc */
1669#define DM_PARAMS_VMALLOC 0x0002 /* Params alloced with vmalloc */
1670#define DM_WIPE_BUFFER 0x0010 /* Wipe input buffer before returning from ioctl */
1671
1672static void free_params(struct dm_ioctl *param, size_t param_size, int param_flags)
1673{
1674 if (param_flags & DM_WIPE_BUFFER)
1675 memset(param, 0, param_size);
1676
1677 if (param_flags & DM_PARAMS_KMALLOC)
1678 kfree(param);
1679 if (param_flags & DM_PARAMS_VMALLOC)
1680 vfree(param);
1681}
1682
1683static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel,
1684 int ioctl_flags,
1685 struct dm_ioctl **param, int *param_flags)
1686{
1687 struct dm_ioctl *dmi;
1688 int secure_data;
1689 const size_t minimum_data_size = sizeof(*param_kernel) - sizeof(param_kernel->data);
1690
1691 if (copy_from_user(param_kernel, user, minimum_data_size))
1692 return -EFAULT;
1693
1694 if (param_kernel->data_size < minimum_data_size)
1695 return -EINVAL;
1696
1697 secure_data = param_kernel->flags & DM_SECURE_DATA_FLAG;
1698
1699 *param_flags = secure_data ? DM_WIPE_BUFFER : 0;
1700
1701 if (ioctl_flags & IOCTL_FLAGS_NO_PARAMS) {
1702 dmi = param_kernel;
1703 dmi->data_size = minimum_data_size;
1704 goto data_copied;
1705 }
1706
1707 /*
1708 * Try to avoid low memory issues when a device is suspended.
1709 * Use kmalloc() rather than vmalloc() when we can.
1710 */
1711 dmi = NULL;
1712 if (param_kernel->data_size <= KMALLOC_MAX_SIZE) {
1713 dmi = kmalloc(param_kernel->data_size, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN);
1714 if (dmi)
1715 *param_flags |= DM_PARAMS_KMALLOC;
1716 }
1717
1718 if (!dmi) {
1719 unsigned noio_flag;
1720 noio_flag = memalloc_noio_save();
1721 dmi = __vmalloc(param_kernel->data_size, GFP_NOIO | __GFP_REPEAT | __GFP_HIGH | __GFP_HIGHMEM, PAGE_KERNEL);
1722 memalloc_noio_restore(noio_flag);
1723 if (dmi)
1724 *param_flags |= DM_PARAMS_VMALLOC;
1725 }
1726
1727 if (!dmi) {
1728 if (secure_data && clear_user(user, param_kernel->data_size))
1729 return -EFAULT;
1730 return -ENOMEM;
1731 }
1732
1733 if (copy_from_user(dmi, user, param_kernel->data_size))
1734 goto bad;
1735
1736data_copied:
1737 /*
1738 * Abort if something changed the ioctl data while it was being copied.
1739 */
1740 if (dmi->data_size != param_kernel->data_size) {
1741 DMERR("rejecting ioctl: data size modified while processing parameters");
1742 goto bad;
1743 }
1744
1745 /* Wipe the user buffer so we do not return it to userspace */
1746 if (secure_data && clear_user(user, param_kernel->data_size))
1747 goto bad;
1748
1749 *param = dmi;
1750 return 0;
1751
1752bad:
1753 free_params(dmi, param_kernel->data_size, *param_flags);
1754
1755 return -EFAULT;
1756}
1757
1758static int validate_params(uint cmd, struct dm_ioctl *param)
1759{
1760 /* Always clear this flag */
1761 param->flags &= ~DM_BUFFER_FULL_FLAG;
1762 param->flags &= ~DM_UEVENT_GENERATED_FLAG;
1763 param->flags &= ~DM_SECURE_DATA_FLAG;
1764 param->flags &= ~DM_DATA_OUT_FLAG;
1765
1766 /* Ignores parameters */
1767 if (cmd == DM_REMOVE_ALL_CMD ||
1768 cmd == DM_LIST_DEVICES_CMD ||
1769 cmd == DM_LIST_VERSIONS_CMD)
1770 return 0;
1771
1772 if ((cmd == DM_DEV_CREATE_CMD)) {
1773 if (!*param->name) {
1774 DMWARN("name not supplied when creating device");
1775 return -EINVAL;
1776 }
1777 } else if ((*param->uuid && *param->name)) {
1778 DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
1779 return -EINVAL;
1780 }
1781
1782 /* Ensure strings are terminated */
1783 param->name[DM_NAME_LEN - 1] = '\0';
1784 param->uuid[DM_UUID_LEN - 1] = '\0';
1785
1786 return 0;
1787}
1788
1789static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
1790{
1791 int r = 0;
1792 int ioctl_flags;
1793 int param_flags;
1794 unsigned int cmd;
1795 struct dm_ioctl *uninitialized_var(param);
1796 ioctl_fn fn = NULL;
1797 size_t input_param_size;
1798 struct dm_ioctl param_kernel;
1799
1800 /* only root can play with this */
1801 if (!capable(CAP_SYS_ADMIN))
1802 return -EACCES;
1803
1804 if (_IOC_TYPE(command) != DM_IOCTL)
1805 return -ENOTTY;
1806
1807 cmd = _IOC_NR(command);
1808
1809 /*
1810 * Check the interface version passed in. This also
1811 * writes out the kernel's interface version.
1812 */
1813 r = check_version(cmd, user);
1814 if (r)
1815 return r;
1816
1817 /*
1818 * Nothing more to do for the version command.
1819 */
1820 if (cmd == DM_VERSION_CMD)
1821 return 0;
1822
1823 fn = lookup_ioctl(cmd, &ioctl_flags);
1824 if (!fn) {
1825 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1826 return -ENOTTY;
1827 }
1828
1829 /*
1830 * Copy the parameters into kernel space.
1831 */
1832 r = copy_params(user, ¶m_kernel, ioctl_flags, ¶m, ¶m_flags);
1833
1834 if (r)
1835 return r;
1836
1837 input_param_size = param->data_size;
1838 r = validate_params(cmd, param);
1839 if (r)
1840 goto out;
1841
1842 param->data_size = sizeof(*param);
1843 r = fn(param, input_param_size);
1844
1845 if (unlikely(param->flags & DM_BUFFER_FULL_FLAG) &&
1846 unlikely(ioctl_flags & IOCTL_FLAGS_NO_PARAMS))
1847 DMERR("ioctl %d tried to output some data but has IOCTL_FLAGS_NO_PARAMS set", cmd);
1848
1849 /*
1850 * Copy the results back to userland.
1851 */
1852 if (!r && copy_to_user(user, param, param->data_size))
1853 r = -EFAULT;
1854
1855out:
1856 free_params(param, input_param_size, param_flags);
1857 return r;
1858}
1859
1860static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
1861{
1862 return (long)ctl_ioctl(command, (struct dm_ioctl __user *)u);
1863}
1864
1865#ifdef CONFIG_COMPAT
1866static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
1867{
1868 return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
1869}
1870#else
1871#define dm_compat_ctl_ioctl NULL
1872#endif
1873
1874static const struct file_operations _ctl_fops = {
1875 .open = nonseekable_open,
1876 .unlocked_ioctl = dm_ctl_ioctl,
1877 .compat_ioctl = dm_compat_ctl_ioctl,
1878 .owner = THIS_MODULE,
1879 .llseek = noop_llseek,
1880};
1881
1882static struct miscdevice _dm_misc = {
1883 .minor = MAPPER_CTRL_MINOR,
1884 .name = DM_NAME,
1885 .nodename = DM_DIR "/" DM_CONTROL_NODE,
1886 .fops = &_ctl_fops
1887};
1888
1889MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
1890MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
1891
1892/*
1893 * Create misc character device and link to DM_DIR/control.
1894 */
1895int __init dm_interface_init(void)
1896{
1897 int r;
1898
1899 r = dm_hash_init();
1900 if (r)
1901 return r;
1902
1903 r = misc_register(&_dm_misc);
1904 if (r) {
1905 DMERR("misc_register failed for control device");
1906 dm_hash_exit();
1907 return r;
1908 }
1909
1910 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
1911 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
1912 DM_DRIVER_EMAIL);
1913 return 0;
1914}
1915
1916void dm_interface_exit(void)
1917{
1918 if (misc_deregister(&_dm_misc) < 0)
1919 DMERR("misc_deregister failed for control device");
1920
1921 dm_hash_exit();
1922}
1923
1924/**
1925 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
1926 * @md: Pointer to mapped_device
1927 * @name: Buffer (size DM_NAME_LEN) for name
1928 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
1929 */
1930int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
1931{
1932 int r = 0;
1933 struct hash_cell *hc;
1934
1935 if (!md)
1936 return -ENXIO;
1937
1938 mutex_lock(&dm_hash_cells_mutex);
1939 hc = dm_get_mdptr(md);
1940 if (!hc || hc->md != md) {
1941 r = -ENXIO;
1942 goto out;
1943 }
1944
1945 if (name)
1946 strcpy(name, hc->name);
1947 if (uuid)
1948 strcpy(uuid, hc->uuid ? : "");
1949
1950out:
1951 mutex_unlock(&dm_hash_cells_mutex);
1952
1953 return r;
1954}