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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-core.h"
9
10#include <linux/module.h>
11#include <linux/vmalloc.h>
12#include <linux/miscdevice.h>
13#include <linux/sched/mm.h>
14#include <linux/init.h>
15#include <linux/wait.h>
16#include <linux/slab.h>
17#include <linux/dm-ioctl.h>
18#include <linux/hdreg.h>
19#include <linux/compat.h>
20
21#include <linux/uaccess.h>
22
23#define DM_MSG_PREFIX "ioctl"
24#define DM_DRIVER_EMAIL "dm-devel@redhat.com"
25
26struct dm_file {
27 /*
28 * poll will wait until the global event number is greater than
29 * this value.
30 */
31 volatile unsigned global_event_nr;
32};
33
34/*-----------------------------------------------------------------
35 * The ioctl interface needs to be able to look up devices by
36 * name or uuid.
37 *---------------------------------------------------------------*/
38struct hash_cell {
39 struct list_head name_list;
40 struct list_head uuid_list;
41
42 char *name;
43 char *uuid;
44 struct mapped_device *md;
45 struct dm_table *new_map;
46};
47
48struct vers_iter {
49 size_t param_size;
50 struct dm_target_versions *vers, *old_vers;
51 char *end;
52 uint32_t flags;
53};
54
55
56#define NUM_BUCKETS 64
57#define MASK_BUCKETS (NUM_BUCKETS - 1)
58static struct list_head _name_buckets[NUM_BUCKETS];
59static struct list_head _uuid_buckets[NUM_BUCKETS];
60
61static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred);
62
63/*
64 * Guards access to both hash tables.
65 */
66static DECLARE_RWSEM(_hash_lock);
67
68/*
69 * Protects use of mdptr to obtain hash cell name and uuid from mapped device.
70 */
71static DEFINE_MUTEX(dm_hash_cells_mutex);
72
73static void init_buckets(struct list_head *buckets)
74{
75 unsigned int i;
76
77 for (i = 0; i < NUM_BUCKETS; i++)
78 INIT_LIST_HEAD(buckets + i);
79}
80
81static int dm_hash_init(void)
82{
83 init_buckets(_name_buckets);
84 init_buckets(_uuid_buckets);
85 return 0;
86}
87
88static void dm_hash_exit(void)
89{
90 dm_hash_remove_all(false, false, false);
91}
92
93/*-----------------------------------------------------------------
94 * Hash function:
95 * We're not really concerned with the str hash function being
96 * fast since it's only used by the ioctl interface.
97 *---------------------------------------------------------------*/
98static unsigned int hash_str(const char *str)
99{
100 const unsigned int hash_mult = 2654435387U;
101 unsigned int h = 0;
102
103 while (*str)
104 h = (h + (unsigned int) *str++) * hash_mult;
105
106 return h & MASK_BUCKETS;
107}
108
109/*-----------------------------------------------------------------
110 * Code for looking up a device by name
111 *---------------------------------------------------------------*/
112static struct hash_cell *__get_name_cell(const char *str)
113{
114 struct hash_cell *hc;
115 unsigned int h = hash_str(str);
116
117 list_for_each_entry (hc, _name_buckets + h, name_list)
118 if (!strcmp(hc->name, str)) {
119 dm_get(hc->md);
120 return hc;
121 }
122
123 return NULL;
124}
125
126static struct hash_cell *__get_uuid_cell(const char *str)
127{
128 struct hash_cell *hc;
129 unsigned int h = hash_str(str);
130
131 list_for_each_entry (hc, _uuid_buckets + h, uuid_list)
132 if (!strcmp(hc->uuid, str)) {
133 dm_get(hc->md);
134 return hc;
135 }
136
137 return NULL;
138}
139
140static struct hash_cell *__get_dev_cell(uint64_t dev)
141{
142 struct mapped_device *md;
143 struct hash_cell *hc;
144
145 md = dm_get_md(huge_decode_dev(dev));
146 if (!md)
147 return NULL;
148
149 hc = dm_get_mdptr(md);
150 if (!hc) {
151 dm_put(md);
152 return NULL;
153 }
154
155 return hc;
156}
157
158/*-----------------------------------------------------------------
159 * Inserting, removing and renaming a device.
160 *---------------------------------------------------------------*/
161static struct hash_cell *alloc_cell(const char *name, const char *uuid,
162 struct mapped_device *md)
163{
164 struct hash_cell *hc;
165
166 hc = kmalloc(sizeof(*hc), GFP_KERNEL);
167 if (!hc)
168 return NULL;
169
170 hc->name = kstrdup(name, GFP_KERNEL);
171 if (!hc->name) {
172 kfree(hc);
173 return NULL;
174 }
175
176 if (!uuid)
177 hc->uuid = NULL;
178
179 else {
180 hc->uuid = kstrdup(uuid, GFP_KERNEL);
181 if (!hc->uuid) {
182 kfree(hc->name);
183 kfree(hc);
184 return NULL;
185 }
186 }
187
188 INIT_LIST_HEAD(&hc->name_list);
189 INIT_LIST_HEAD(&hc->uuid_list);
190 hc->md = md;
191 hc->new_map = NULL;
192 return hc;
193}
194
195static void free_cell(struct hash_cell *hc)
196{
197 if (hc) {
198 kfree(hc->name);
199 kfree(hc->uuid);
200 kfree(hc);
201 }
202}
203
204/*
205 * The kdev_t and uuid of a device can never change once it is
206 * initially inserted.
207 */
208static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
209{
210 struct hash_cell *cell, *hc;
211
212 /*
213 * Allocate the new cells.
214 */
215 cell = alloc_cell(name, uuid, md);
216 if (!cell)
217 return -ENOMEM;
218
219 /*
220 * Insert the cell into both hash tables.
221 */
222 down_write(&_hash_lock);
223 hc = __get_name_cell(name);
224 if (hc) {
225 dm_put(hc->md);
226 goto bad;
227 }
228
229 list_add(&cell->name_list, _name_buckets + hash_str(name));
230
231 if (uuid) {
232 hc = __get_uuid_cell(uuid);
233 if (hc) {
234 list_del(&cell->name_list);
235 dm_put(hc->md);
236 goto bad;
237 }
238 list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
239 }
240 dm_get(md);
241 mutex_lock(&dm_hash_cells_mutex);
242 dm_set_mdptr(md, cell);
243 mutex_unlock(&dm_hash_cells_mutex);
244 up_write(&_hash_lock);
245
246 return 0;
247
248 bad:
249 up_write(&_hash_lock);
250 free_cell(cell);
251 return -EBUSY;
252}
253
254static struct dm_table *__hash_remove(struct hash_cell *hc)
255{
256 struct dm_table *table;
257 int srcu_idx;
258
259 /* remove from the dev hash */
260 list_del(&hc->uuid_list);
261 list_del(&hc->name_list);
262 mutex_lock(&dm_hash_cells_mutex);
263 dm_set_mdptr(hc->md, NULL);
264 mutex_unlock(&dm_hash_cells_mutex);
265
266 table = dm_get_live_table(hc->md, &srcu_idx);
267 if (table)
268 dm_table_event(table);
269 dm_put_live_table(hc->md, srcu_idx);
270
271 table = NULL;
272 if (hc->new_map)
273 table = hc->new_map;
274 dm_put(hc->md);
275 free_cell(hc);
276
277 return table;
278}
279
280static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred)
281{
282 int i, dev_skipped;
283 struct hash_cell *hc;
284 struct mapped_device *md;
285 struct dm_table *t;
286
287retry:
288 dev_skipped = 0;
289
290 down_write(&_hash_lock);
291
292 for (i = 0; i < NUM_BUCKETS; i++) {
293 list_for_each_entry(hc, _name_buckets + i, name_list) {
294 md = hc->md;
295 dm_get(md);
296
297 if (keep_open_devices &&
298 dm_lock_for_deletion(md, mark_deferred, only_deferred)) {
299 dm_put(md);
300 dev_skipped++;
301 continue;
302 }
303
304 t = __hash_remove(hc);
305
306 up_write(&_hash_lock);
307
308 if (t) {
309 dm_sync_table(md);
310 dm_table_destroy(t);
311 }
312 dm_put(md);
313 if (likely(keep_open_devices))
314 dm_destroy(md);
315 else
316 dm_destroy_immediate(md);
317
318 /*
319 * Some mapped devices may be using other mapped
320 * devices, so repeat until we make no further
321 * progress. If a new mapped device is created
322 * here it will also get removed.
323 */
324 goto retry;
325 }
326 }
327
328 up_write(&_hash_lock);
329
330 if (dev_skipped)
331 DMWARN("remove_all left %d open device(s)", dev_skipped);
332}
333
334/*
335 * Set the uuid of a hash_cell that isn't already set.
336 */
337static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
338{
339 mutex_lock(&dm_hash_cells_mutex);
340 hc->uuid = new_uuid;
341 mutex_unlock(&dm_hash_cells_mutex);
342
343 list_add(&hc->uuid_list, _uuid_buckets + hash_str(new_uuid));
344}
345
346/*
347 * Changes the name of a hash_cell and returns the old name for
348 * the caller to free.
349 */
350static char *__change_cell_name(struct hash_cell *hc, char *new_name)
351{
352 char *old_name;
353
354 /*
355 * Rename and move the name cell.
356 */
357 list_del(&hc->name_list);
358 old_name = hc->name;
359
360 mutex_lock(&dm_hash_cells_mutex);
361 hc->name = new_name;
362 mutex_unlock(&dm_hash_cells_mutex);
363
364 list_add(&hc->name_list, _name_buckets + hash_str(new_name));
365
366 return old_name;
367}
368
369static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
370 const char *new)
371{
372 char *new_data, *old_name = NULL;
373 struct hash_cell *hc;
374 struct dm_table *table;
375 struct mapped_device *md;
376 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
377 int srcu_idx;
378
379 /*
380 * duplicate new.
381 */
382 new_data = kstrdup(new, GFP_KERNEL);
383 if (!new_data)
384 return ERR_PTR(-ENOMEM);
385
386 down_write(&_hash_lock);
387
388 /*
389 * Is new free ?
390 */
391 if (change_uuid)
392 hc = __get_uuid_cell(new);
393 else
394 hc = __get_name_cell(new);
395
396 if (hc) {
397 DMWARN("Unable to change %s on mapped device %s to one that "
398 "already exists: %s",
399 change_uuid ? "uuid" : "name",
400 param->name, new);
401 dm_put(hc->md);
402 up_write(&_hash_lock);
403 kfree(new_data);
404 return ERR_PTR(-EBUSY);
405 }
406
407 /*
408 * Is there such a device as 'old' ?
409 */
410 hc = __get_name_cell(param->name);
411 if (!hc) {
412 DMWARN("Unable to rename non-existent device, %s to %s%s",
413 param->name, change_uuid ? "uuid " : "", new);
414 up_write(&_hash_lock);
415 kfree(new_data);
416 return ERR_PTR(-ENXIO);
417 }
418
419 /*
420 * Does this device already have a uuid?
421 */
422 if (change_uuid && hc->uuid) {
423 DMWARN("Unable to change uuid of mapped device %s to %s "
424 "because uuid is already set to %s",
425 param->name, new, hc->uuid);
426 dm_put(hc->md);
427 up_write(&_hash_lock);
428 kfree(new_data);
429 return ERR_PTR(-EINVAL);
430 }
431
432 if (change_uuid)
433 __set_cell_uuid(hc, new_data);
434 else
435 old_name = __change_cell_name(hc, new_data);
436
437 /*
438 * Wake up any dm event waiters.
439 */
440 table = dm_get_live_table(hc->md, &srcu_idx);
441 if (table)
442 dm_table_event(table);
443 dm_put_live_table(hc->md, srcu_idx);
444
445 if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr))
446 param->flags |= DM_UEVENT_GENERATED_FLAG;
447
448 md = hc->md;
449 up_write(&_hash_lock);
450 kfree(old_name);
451
452 return md;
453}
454
455void dm_deferred_remove(void)
456{
457 dm_hash_remove_all(true, false, true);
458}
459
460/*-----------------------------------------------------------------
461 * Implementation of the ioctl commands
462 *---------------------------------------------------------------*/
463/*
464 * All the ioctl commands get dispatched to functions with this
465 * prototype.
466 */
467typedef int (*ioctl_fn)(struct file *filp, struct dm_ioctl *param, size_t param_size);
468
469static int remove_all(struct file *filp, struct dm_ioctl *param, size_t param_size)
470{
471 dm_hash_remove_all(true, !!(param->flags & DM_DEFERRED_REMOVE), false);
472 param->data_size = 0;
473 return 0;
474}
475
476/*
477 * Round up the ptr to an 8-byte boundary.
478 */
479#define ALIGN_MASK 7
480static inline size_t align_val(size_t val)
481{
482 return (val + ALIGN_MASK) & ~ALIGN_MASK;
483}
484static inline void *align_ptr(void *ptr)
485{
486 return (void *)align_val((size_t)ptr);
487}
488
489/*
490 * Retrieves the data payload buffer from an already allocated
491 * struct dm_ioctl.
492 */
493static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
494 size_t *len)
495{
496 param->data_start = align_ptr(param + 1) - (void *) param;
497
498 if (param->data_start < param_size)
499 *len = param_size - param->data_start;
500 else
501 *len = 0;
502
503 return ((void *) param) + param->data_start;
504}
505
506static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_size)
507{
508 unsigned int i;
509 struct hash_cell *hc;
510 size_t len, needed = 0;
511 struct gendisk *disk;
512 struct dm_name_list *orig_nl, *nl, *old_nl = NULL;
513 uint32_t *event_nr;
514
515 down_write(&_hash_lock);
516
517 /*
518 * Loop through all the devices working out how much
519 * space we need.
520 */
521 for (i = 0; i < NUM_BUCKETS; i++) {
522 list_for_each_entry (hc, _name_buckets + i, name_list) {
523 needed += align_val(offsetof(struct dm_name_list, name) + strlen(hc->name) + 1);
524 needed += align_val(sizeof(uint32_t));
525 }
526 }
527
528 /*
529 * Grab our output buffer.
530 */
531 nl = orig_nl = get_result_buffer(param, param_size, &len);
532 if (len < needed) {
533 param->flags |= DM_BUFFER_FULL_FLAG;
534 goto out;
535 }
536 param->data_size = param->data_start + needed;
537
538 nl->dev = 0; /* Flags no data */
539
540 /*
541 * Now loop through filling out the names.
542 */
543 for (i = 0; i < NUM_BUCKETS; i++) {
544 list_for_each_entry (hc, _name_buckets + i, name_list) {
545 if (old_nl)
546 old_nl->next = (uint32_t) ((void *) nl -
547 (void *) old_nl);
548 disk = dm_disk(hc->md);
549 nl->dev = huge_encode_dev(disk_devt(disk));
550 nl->next = 0;
551 strcpy(nl->name, hc->name);
552
553 old_nl = nl;
554 event_nr = align_ptr(nl->name + strlen(hc->name) + 1);
555 *event_nr = dm_get_event_nr(hc->md);
556 nl = align_ptr(event_nr + 1);
557 }
558 }
559 /*
560 * If mismatch happens, security may be compromised due to buffer
561 * overflow, so it's better to crash.
562 */
563 BUG_ON((char *)nl - (char *)orig_nl != needed);
564
565 out:
566 up_write(&_hash_lock);
567 return 0;
568}
569
570static void list_version_get_needed(struct target_type *tt, void *needed_param)
571{
572 size_t *needed = needed_param;
573
574 *needed += sizeof(struct dm_target_versions);
575 *needed += strlen(tt->name);
576 *needed += ALIGN_MASK;
577}
578
579static void list_version_get_info(struct target_type *tt, void *param)
580{
581 struct vers_iter *info = param;
582
583 /* Check space - it might have changed since the first iteration */
584 if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
585 info->end) {
586
587 info->flags = DM_BUFFER_FULL_FLAG;
588 return;
589 }
590
591 if (info->old_vers)
592 info->old_vers->next = (uint32_t) ((void *)info->vers -
593 (void *)info->old_vers);
594 info->vers->version[0] = tt->version[0];
595 info->vers->version[1] = tt->version[1];
596 info->vers->version[2] = tt->version[2];
597 info->vers->next = 0;
598 strcpy(info->vers->name, tt->name);
599
600 info->old_vers = info->vers;
601 info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
602}
603
604static int __list_versions(struct dm_ioctl *param, size_t param_size, const char *name)
605{
606 size_t len, needed = 0;
607 struct dm_target_versions *vers;
608 struct vers_iter iter_info;
609 struct target_type *tt = NULL;
610
611 if (name) {
612 tt = dm_get_target_type(name);
613 if (!tt)
614 return -EINVAL;
615 }
616
617 /*
618 * Loop through all the devices working out how much
619 * space we need.
620 */
621 if (!tt)
622 dm_target_iterate(list_version_get_needed, &needed);
623 else
624 list_version_get_needed(tt, &needed);
625
626 /*
627 * Grab our output buffer.
628 */
629 vers = get_result_buffer(param, param_size, &len);
630 if (len < needed) {
631 param->flags |= DM_BUFFER_FULL_FLAG;
632 goto out;
633 }
634 param->data_size = param->data_start + needed;
635
636 iter_info.param_size = param_size;
637 iter_info.old_vers = NULL;
638 iter_info.vers = vers;
639 iter_info.flags = 0;
640 iter_info.end = (char *)vers+len;
641
642 /*
643 * Now loop through filling out the names & versions.
644 */
645 if (!tt)
646 dm_target_iterate(list_version_get_info, &iter_info);
647 else
648 list_version_get_info(tt, &iter_info);
649 param->flags |= iter_info.flags;
650
651 out:
652 if (tt)
653 dm_put_target_type(tt);
654 return 0;
655}
656
657static int list_versions(struct file *filp, struct dm_ioctl *param, size_t param_size)
658{
659 return __list_versions(param, param_size, NULL);
660}
661
662static int get_target_version(struct file *filp, struct dm_ioctl *param, size_t param_size)
663{
664 return __list_versions(param, param_size, param->name);
665}
666
667static int check_name(const char *name)
668{
669 if (strchr(name, '/')) {
670 DMWARN("invalid device name");
671 return -EINVAL;
672 }
673
674 return 0;
675}
676
677/*
678 * On successful return, the caller must not attempt to acquire
679 * _hash_lock without first calling dm_put_live_table, because dm_table_destroy
680 * waits for this dm_put_live_table and could be called under this lock.
681 */
682static struct dm_table *dm_get_inactive_table(struct mapped_device *md, int *srcu_idx)
683{
684 struct hash_cell *hc;
685 struct dm_table *table = NULL;
686
687 /* increment rcu count, we don't care about the table pointer */
688 dm_get_live_table(md, srcu_idx);
689
690 down_read(&_hash_lock);
691 hc = dm_get_mdptr(md);
692 if (!hc || hc->md != md) {
693 DMWARN("device has been removed from the dev hash table.");
694 goto out;
695 }
696
697 table = hc->new_map;
698
699out:
700 up_read(&_hash_lock);
701
702 return table;
703}
704
705static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
706 struct dm_ioctl *param,
707 int *srcu_idx)
708{
709 return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
710 dm_get_inactive_table(md, srcu_idx) : dm_get_live_table(md, srcu_idx);
711}
712
713/*
714 * Fills in a dm_ioctl structure, ready for sending back to
715 * userland.
716 */
717static void __dev_status(struct mapped_device *md, struct dm_ioctl *param)
718{
719 struct gendisk *disk = dm_disk(md);
720 struct dm_table *table;
721 int srcu_idx;
722
723 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
724 DM_ACTIVE_PRESENT_FLAG | DM_INTERNAL_SUSPEND_FLAG);
725
726 if (dm_suspended_md(md))
727 param->flags |= DM_SUSPEND_FLAG;
728
729 if (dm_suspended_internally_md(md))
730 param->flags |= DM_INTERNAL_SUSPEND_FLAG;
731
732 if (dm_test_deferred_remove_flag(md))
733 param->flags |= DM_DEFERRED_REMOVE;
734
735 param->dev = huge_encode_dev(disk_devt(disk));
736
737 /*
738 * Yes, this will be out of date by the time it gets back
739 * to userland, but it is still very useful for
740 * debugging.
741 */
742 param->open_count = dm_open_count(md);
743
744 param->event_nr = dm_get_event_nr(md);
745 param->target_count = 0;
746
747 table = dm_get_live_table(md, &srcu_idx);
748 if (table) {
749 if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
750 if (get_disk_ro(disk))
751 param->flags |= DM_READONLY_FLAG;
752 param->target_count = dm_table_get_num_targets(table);
753 }
754
755 param->flags |= DM_ACTIVE_PRESENT_FLAG;
756 }
757 dm_put_live_table(md, srcu_idx);
758
759 if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
760 int srcu_idx;
761 table = dm_get_inactive_table(md, &srcu_idx);
762 if (table) {
763 if (!(dm_table_get_mode(table) & FMODE_WRITE))
764 param->flags |= DM_READONLY_FLAG;
765 param->target_count = dm_table_get_num_targets(table);
766 }
767 dm_put_live_table(md, srcu_idx);
768 }
769}
770
771static int dev_create(struct file *filp, struct dm_ioctl *param, size_t param_size)
772{
773 int r, m = DM_ANY_MINOR;
774 struct mapped_device *md;
775
776 r = check_name(param->name);
777 if (r)
778 return r;
779
780 if (param->flags & DM_PERSISTENT_DEV_FLAG)
781 m = MINOR(huge_decode_dev(param->dev));
782
783 r = dm_create(m, &md);
784 if (r)
785 return r;
786
787 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
788 if (r) {
789 dm_put(md);
790 dm_destroy(md);
791 return r;
792 }
793
794 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
795
796 __dev_status(md, param);
797
798 dm_put(md);
799
800 return 0;
801}
802
803/*
804 * Always use UUID for lookups if it's present, otherwise use name or dev.
805 */
806static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
807{
808 struct hash_cell *hc = NULL;
809
810 if (*param->uuid) {
811 if (*param->name || param->dev)
812 return NULL;
813
814 hc = __get_uuid_cell(param->uuid);
815 if (!hc)
816 return NULL;
817 } else if (*param->name) {
818 if (param->dev)
819 return NULL;
820
821 hc = __get_name_cell(param->name);
822 if (!hc)
823 return NULL;
824 } else if (param->dev) {
825 hc = __get_dev_cell(param->dev);
826 if (!hc)
827 return NULL;
828 } else
829 return NULL;
830
831 /*
832 * Sneakily write in both the name and the uuid
833 * while we have the cell.
834 */
835 strlcpy(param->name, hc->name, sizeof(param->name));
836 if (hc->uuid)
837 strlcpy(param->uuid, hc->uuid, sizeof(param->uuid));
838 else
839 param->uuid[0] = '\0';
840
841 if (hc->new_map)
842 param->flags |= DM_INACTIVE_PRESENT_FLAG;
843 else
844 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
845
846 return hc;
847}
848
849static struct mapped_device *find_device(struct dm_ioctl *param)
850{
851 struct hash_cell *hc;
852 struct mapped_device *md = NULL;
853
854 down_read(&_hash_lock);
855 hc = __find_device_hash_cell(param);
856 if (hc)
857 md = hc->md;
858 up_read(&_hash_lock);
859
860 return md;
861}
862
863static int dev_remove(struct file *filp, struct dm_ioctl *param, size_t param_size)
864{
865 struct hash_cell *hc;
866 struct mapped_device *md;
867 int r;
868 struct dm_table *t;
869
870 down_write(&_hash_lock);
871 hc = __find_device_hash_cell(param);
872
873 if (!hc) {
874 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
875 up_write(&_hash_lock);
876 return -ENXIO;
877 }
878
879 md = hc->md;
880
881 /*
882 * Ensure the device is not open and nothing further can open it.
883 */
884 r = dm_lock_for_deletion(md, !!(param->flags & DM_DEFERRED_REMOVE), false);
885 if (r) {
886 if (r == -EBUSY && param->flags & DM_DEFERRED_REMOVE) {
887 up_write(&_hash_lock);
888 dm_put(md);
889 return 0;
890 }
891 DMDEBUG_LIMIT("unable to remove open device %s", hc->name);
892 up_write(&_hash_lock);
893 dm_put(md);
894 return r;
895 }
896
897 t = __hash_remove(hc);
898 up_write(&_hash_lock);
899
900 if (t) {
901 dm_sync_table(md);
902 dm_table_destroy(t);
903 }
904
905 param->flags &= ~DM_DEFERRED_REMOVE;
906
907 if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr))
908 param->flags |= DM_UEVENT_GENERATED_FLAG;
909
910 dm_put(md);
911 dm_destroy(md);
912 return 0;
913}
914
915/*
916 * Check a string doesn't overrun the chunk of
917 * memory we copied from userland.
918 */
919static int invalid_str(char *str, void *end)
920{
921 while ((void *) str < end)
922 if (!*str++)
923 return 0;
924
925 return -EINVAL;
926}
927
928static int dev_rename(struct file *filp, struct dm_ioctl *param, size_t param_size)
929{
930 int r;
931 char *new_data = (char *) param + param->data_start;
932 struct mapped_device *md;
933 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
934
935 if (new_data < param->data ||
936 invalid_str(new_data, (void *) param + param_size) || !*new_data ||
937 strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
938 DMWARN("Invalid new mapped device name or uuid string supplied.");
939 return -EINVAL;
940 }
941
942 if (!change_uuid) {
943 r = check_name(new_data);
944 if (r)
945 return r;
946 }
947
948 md = dm_hash_rename(param, new_data);
949 if (IS_ERR(md))
950 return PTR_ERR(md);
951
952 __dev_status(md, param);
953 dm_put(md);
954
955 return 0;
956}
957
958static int dev_set_geometry(struct file *filp, struct dm_ioctl *param, size_t param_size)
959{
960 int r = -EINVAL, x;
961 struct mapped_device *md;
962 struct hd_geometry geometry;
963 unsigned long indata[4];
964 char *geostr = (char *) param + param->data_start;
965 char dummy;
966
967 md = find_device(param);
968 if (!md)
969 return -ENXIO;
970
971 if (geostr < param->data ||
972 invalid_str(geostr, (void *) param + param_size)) {
973 DMWARN("Invalid geometry supplied.");
974 goto out;
975 }
976
977 x = sscanf(geostr, "%lu %lu %lu %lu%c", indata,
978 indata + 1, indata + 2, indata + 3, &dummy);
979
980 if (x != 4) {
981 DMWARN("Unable to interpret geometry settings.");
982 goto out;
983 }
984
985 if (indata[0] > 65535 || indata[1] > 255 ||
986 indata[2] > 255 || indata[3] > ULONG_MAX) {
987 DMWARN("Geometry exceeds range limits.");
988 goto out;
989 }
990
991 geometry.cylinders = indata[0];
992 geometry.heads = indata[1];
993 geometry.sectors = indata[2];
994 geometry.start = indata[3];
995
996 r = dm_set_geometry(md, &geometry);
997
998 param->data_size = 0;
999
1000out:
1001 dm_put(md);
1002 return r;
1003}
1004
1005static int do_suspend(struct dm_ioctl *param)
1006{
1007 int r = 0;
1008 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
1009 struct mapped_device *md;
1010
1011 md = find_device(param);
1012 if (!md)
1013 return -ENXIO;
1014
1015 if (param->flags & DM_SKIP_LOCKFS_FLAG)
1016 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
1017 if (param->flags & DM_NOFLUSH_FLAG)
1018 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
1019
1020 if (!dm_suspended_md(md)) {
1021 r = dm_suspend(md, suspend_flags);
1022 if (r)
1023 goto out;
1024 }
1025
1026 __dev_status(md, param);
1027
1028out:
1029 dm_put(md);
1030
1031 return r;
1032}
1033
1034static int do_resume(struct dm_ioctl *param)
1035{
1036 int r = 0;
1037 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
1038 struct hash_cell *hc;
1039 struct mapped_device *md;
1040 struct dm_table *new_map, *old_map = NULL;
1041
1042 down_write(&_hash_lock);
1043
1044 hc = __find_device_hash_cell(param);
1045 if (!hc) {
1046 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1047 up_write(&_hash_lock);
1048 return -ENXIO;
1049 }
1050
1051 md = hc->md;
1052
1053 new_map = hc->new_map;
1054 hc->new_map = NULL;
1055 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1056
1057 up_write(&_hash_lock);
1058
1059 /* Do we need to load a new map ? */
1060 if (new_map) {
1061 /* Suspend if it isn't already suspended */
1062 if (param->flags & DM_SKIP_LOCKFS_FLAG)
1063 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
1064 if (param->flags & DM_NOFLUSH_FLAG)
1065 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
1066 if (!dm_suspended_md(md))
1067 dm_suspend(md, suspend_flags);
1068
1069 old_map = dm_swap_table(md, new_map);
1070 if (IS_ERR(old_map)) {
1071 dm_sync_table(md);
1072 dm_table_destroy(new_map);
1073 dm_put(md);
1074 return PTR_ERR(old_map);
1075 }
1076
1077 if (dm_table_get_mode(new_map) & FMODE_WRITE)
1078 set_disk_ro(dm_disk(md), 0);
1079 else
1080 set_disk_ro(dm_disk(md), 1);
1081 }
1082
1083 if (dm_suspended_md(md)) {
1084 r = dm_resume(md);
1085 if (!r && !dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr))
1086 param->flags |= DM_UEVENT_GENERATED_FLAG;
1087 }
1088
1089 /*
1090 * Since dm_swap_table synchronizes RCU, nobody should be in
1091 * read-side critical section already.
1092 */
1093 if (old_map)
1094 dm_table_destroy(old_map);
1095
1096 if (!r)
1097 __dev_status(md, param);
1098
1099 dm_put(md);
1100 return r;
1101}
1102
1103/*
1104 * Set or unset the suspension state of a device.
1105 * If the device already is in the requested state we just return its status.
1106 */
1107static int dev_suspend(struct file *filp, struct dm_ioctl *param, size_t param_size)
1108{
1109 if (param->flags & DM_SUSPEND_FLAG)
1110 return do_suspend(param);
1111
1112 return do_resume(param);
1113}
1114
1115/*
1116 * Copies device info back to user space, used by
1117 * the create and info ioctls.
1118 */
1119static int dev_status(struct file *filp, struct dm_ioctl *param, size_t param_size)
1120{
1121 struct mapped_device *md;
1122
1123 md = find_device(param);
1124 if (!md)
1125 return -ENXIO;
1126
1127 __dev_status(md, param);
1128 dm_put(md);
1129
1130 return 0;
1131}
1132
1133/*
1134 * Build up the status struct for each target
1135 */
1136static void retrieve_status(struct dm_table *table,
1137 struct dm_ioctl *param, size_t param_size)
1138{
1139 unsigned int i, num_targets;
1140 struct dm_target_spec *spec;
1141 char *outbuf, *outptr;
1142 status_type_t type;
1143 size_t remaining, len, used = 0;
1144 unsigned status_flags = 0;
1145
1146 outptr = outbuf = get_result_buffer(param, param_size, &len);
1147
1148 if (param->flags & DM_STATUS_TABLE_FLAG)
1149 type = STATUSTYPE_TABLE;
1150 else
1151 type = STATUSTYPE_INFO;
1152
1153 /* Get all the target info */
1154 num_targets = dm_table_get_num_targets(table);
1155 for (i = 0; i < num_targets; i++) {
1156 struct dm_target *ti = dm_table_get_target(table, i);
1157 size_t l;
1158
1159 remaining = len - (outptr - outbuf);
1160 if (remaining <= sizeof(struct dm_target_spec)) {
1161 param->flags |= DM_BUFFER_FULL_FLAG;
1162 break;
1163 }
1164
1165 spec = (struct dm_target_spec *) outptr;
1166
1167 spec->status = 0;
1168 spec->sector_start = ti->begin;
1169 spec->length = ti->len;
1170 strncpy(spec->target_type, ti->type->name,
1171 sizeof(spec->target_type));
1172
1173 outptr += sizeof(struct dm_target_spec);
1174 remaining = len - (outptr - outbuf);
1175 if (remaining <= 0) {
1176 param->flags |= DM_BUFFER_FULL_FLAG;
1177 break;
1178 }
1179
1180 /* Get the status/table string from the target driver */
1181 if (ti->type->status) {
1182 if (param->flags & DM_NOFLUSH_FLAG)
1183 status_flags |= DM_STATUS_NOFLUSH_FLAG;
1184 ti->type->status(ti, type, status_flags, outptr, remaining);
1185 } else
1186 outptr[0] = '\0';
1187
1188 l = strlen(outptr) + 1;
1189 if (l == remaining) {
1190 param->flags |= DM_BUFFER_FULL_FLAG;
1191 break;
1192 }
1193
1194 outptr += l;
1195 used = param->data_start + (outptr - outbuf);
1196
1197 outptr = align_ptr(outptr);
1198 spec->next = outptr - outbuf;
1199 }
1200
1201 if (used)
1202 param->data_size = used;
1203
1204 param->target_count = num_targets;
1205}
1206
1207/*
1208 * Wait for a device to report an event
1209 */
1210static int dev_wait(struct file *filp, struct dm_ioctl *param, size_t param_size)
1211{
1212 int r = 0;
1213 struct mapped_device *md;
1214 struct dm_table *table;
1215 int srcu_idx;
1216
1217 md = find_device(param);
1218 if (!md)
1219 return -ENXIO;
1220
1221 /*
1222 * Wait for a notification event
1223 */
1224 if (dm_wait_event(md, param->event_nr)) {
1225 r = -ERESTARTSYS;
1226 goto out;
1227 }
1228
1229 /*
1230 * The userland program is going to want to know what
1231 * changed to trigger the event, so we may as well tell
1232 * him and save an ioctl.
1233 */
1234 __dev_status(md, param);
1235
1236 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1237 if (table)
1238 retrieve_status(table, param, param_size);
1239 dm_put_live_table(md, srcu_idx);
1240
1241out:
1242 dm_put(md);
1243
1244 return r;
1245}
1246
1247/*
1248 * Remember the global event number and make it possible to poll
1249 * for further events.
1250 */
1251static int dev_arm_poll(struct file *filp, struct dm_ioctl *param, size_t param_size)
1252{
1253 struct dm_file *priv = filp->private_data;
1254
1255 priv->global_event_nr = atomic_read(&dm_global_event_nr);
1256
1257 return 0;
1258}
1259
1260static inline fmode_t get_mode(struct dm_ioctl *param)
1261{
1262 fmode_t mode = FMODE_READ | FMODE_WRITE;
1263
1264 if (param->flags & DM_READONLY_FLAG)
1265 mode = FMODE_READ;
1266
1267 return mode;
1268}
1269
1270static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
1271 struct dm_target_spec **spec, char **target_params)
1272{
1273 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1274 *target_params = (char *) (*spec + 1);
1275
1276 if (*spec < (last + 1))
1277 return -EINVAL;
1278
1279 return invalid_str(*target_params, end);
1280}
1281
1282static int populate_table(struct dm_table *table,
1283 struct dm_ioctl *param, size_t param_size)
1284{
1285 int r;
1286 unsigned int i = 0;
1287 struct dm_target_spec *spec = (struct dm_target_spec *) param;
1288 uint32_t next = param->data_start;
1289 void *end = (void *) param + param_size;
1290 char *target_params;
1291
1292 if (!param->target_count) {
1293 DMWARN("populate_table: no targets specified");
1294 return -EINVAL;
1295 }
1296
1297 for (i = 0; i < param->target_count; i++) {
1298
1299 r = next_target(spec, next, end, &spec, &target_params);
1300 if (r) {
1301 DMWARN("unable to find target");
1302 return r;
1303 }
1304
1305 r = dm_table_add_target(table, spec->target_type,
1306 (sector_t) spec->sector_start,
1307 (sector_t) spec->length,
1308 target_params);
1309 if (r) {
1310 DMWARN("error adding target to table");
1311 return r;
1312 }
1313
1314 next = spec->next;
1315 }
1316
1317 return dm_table_complete(table);
1318}
1319
1320static bool is_valid_type(enum dm_queue_mode cur, enum dm_queue_mode new)
1321{
1322 if (cur == new ||
1323 (cur == DM_TYPE_BIO_BASED && new == DM_TYPE_DAX_BIO_BASED))
1324 return true;
1325
1326 return false;
1327}
1328
1329static int table_load(struct file *filp, struct dm_ioctl *param, size_t param_size)
1330{
1331 int r;
1332 struct hash_cell *hc;
1333 struct dm_table *t, *old_map = NULL;
1334 struct mapped_device *md;
1335 struct target_type *immutable_target_type;
1336
1337 md = find_device(param);
1338 if (!md)
1339 return -ENXIO;
1340
1341 r = dm_table_create(&t, get_mode(param), param->target_count, md);
1342 if (r)
1343 goto err;
1344
1345 /* Protect md->type and md->queue against concurrent table loads. */
1346 dm_lock_md_type(md);
1347 r = populate_table(t, param, param_size);
1348 if (r)
1349 goto err_unlock_md_type;
1350
1351 immutable_target_type = dm_get_immutable_target_type(md);
1352 if (immutable_target_type &&
1353 (immutable_target_type != dm_table_get_immutable_target_type(t)) &&
1354 !dm_table_get_wildcard_target(t)) {
1355 DMWARN("can't replace immutable target type %s",
1356 immutable_target_type->name);
1357 r = -EINVAL;
1358 goto err_unlock_md_type;
1359 }
1360
1361 if (dm_get_md_type(md) == DM_TYPE_NONE) {
1362 /* Initial table load: acquire type of table. */
1363 dm_set_md_type(md, dm_table_get_type(t));
1364
1365 /* setup md->queue to reflect md's type (may block) */
1366 r = dm_setup_md_queue(md, t);
1367 if (r) {
1368 DMWARN("unable to set up device queue for new table.");
1369 goto err_unlock_md_type;
1370 }
1371 } else if (!is_valid_type(dm_get_md_type(md), dm_table_get_type(t))) {
1372 DMWARN("can't change device type (old=%u vs new=%u) after initial table load.",
1373 dm_get_md_type(md), dm_table_get_type(t));
1374 r = -EINVAL;
1375 goto err_unlock_md_type;
1376 }
1377
1378 dm_unlock_md_type(md);
1379
1380 /* stage inactive table */
1381 down_write(&_hash_lock);
1382 hc = dm_get_mdptr(md);
1383 if (!hc || hc->md != md) {
1384 DMWARN("device has been removed from the dev hash table.");
1385 up_write(&_hash_lock);
1386 r = -ENXIO;
1387 goto err_destroy_table;
1388 }
1389
1390 if (hc->new_map)
1391 old_map = hc->new_map;
1392 hc->new_map = t;
1393 up_write(&_hash_lock);
1394
1395 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1396 __dev_status(md, param);
1397
1398 if (old_map) {
1399 dm_sync_table(md);
1400 dm_table_destroy(old_map);
1401 }
1402
1403 dm_put(md);
1404
1405 return 0;
1406
1407err_unlock_md_type:
1408 dm_unlock_md_type(md);
1409err_destroy_table:
1410 dm_table_destroy(t);
1411err:
1412 dm_put(md);
1413
1414 return r;
1415}
1416
1417static int table_clear(struct file *filp, struct dm_ioctl *param, size_t param_size)
1418{
1419 struct hash_cell *hc;
1420 struct mapped_device *md;
1421 struct dm_table *old_map = NULL;
1422
1423 down_write(&_hash_lock);
1424
1425 hc = __find_device_hash_cell(param);
1426 if (!hc) {
1427 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1428 up_write(&_hash_lock);
1429 return -ENXIO;
1430 }
1431
1432 if (hc->new_map) {
1433 old_map = hc->new_map;
1434 hc->new_map = NULL;
1435 }
1436
1437 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1438
1439 __dev_status(hc->md, param);
1440 md = hc->md;
1441 up_write(&_hash_lock);
1442 if (old_map) {
1443 dm_sync_table(md);
1444 dm_table_destroy(old_map);
1445 }
1446 dm_put(md);
1447
1448 return 0;
1449}
1450
1451/*
1452 * Retrieves a list of devices used by a particular dm device.
1453 */
1454static void retrieve_deps(struct dm_table *table,
1455 struct dm_ioctl *param, size_t param_size)
1456{
1457 unsigned int count = 0;
1458 struct list_head *tmp;
1459 size_t len, needed;
1460 struct dm_dev_internal *dd;
1461 struct dm_target_deps *deps;
1462
1463 deps = get_result_buffer(param, param_size, &len);
1464
1465 /*
1466 * Count the devices.
1467 */
1468 list_for_each (tmp, dm_table_get_devices(table))
1469 count++;
1470
1471 /*
1472 * Check we have enough space.
1473 */
1474 needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
1475 if (len < needed) {
1476 param->flags |= DM_BUFFER_FULL_FLAG;
1477 return;
1478 }
1479
1480 /*
1481 * Fill in the devices.
1482 */
1483 deps->count = count;
1484 count = 0;
1485 list_for_each_entry (dd, dm_table_get_devices(table), list)
1486 deps->dev[count++] = huge_encode_dev(dd->dm_dev->bdev->bd_dev);
1487
1488 param->data_size = param->data_start + needed;
1489}
1490
1491static int table_deps(struct file *filp, struct dm_ioctl *param, size_t param_size)
1492{
1493 struct mapped_device *md;
1494 struct dm_table *table;
1495 int srcu_idx;
1496
1497 md = find_device(param);
1498 if (!md)
1499 return -ENXIO;
1500
1501 __dev_status(md, param);
1502
1503 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1504 if (table)
1505 retrieve_deps(table, param, param_size);
1506 dm_put_live_table(md, srcu_idx);
1507
1508 dm_put(md);
1509
1510 return 0;
1511}
1512
1513/*
1514 * Return the status of a device as a text string for each
1515 * target.
1516 */
1517static int table_status(struct file *filp, struct dm_ioctl *param, size_t param_size)
1518{
1519 struct mapped_device *md;
1520 struct dm_table *table;
1521 int srcu_idx;
1522
1523 md = find_device(param);
1524 if (!md)
1525 return -ENXIO;
1526
1527 __dev_status(md, param);
1528
1529 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1530 if (table)
1531 retrieve_status(table, param, param_size);
1532 dm_put_live_table(md, srcu_idx);
1533
1534 dm_put(md);
1535
1536 return 0;
1537}
1538
1539/*
1540 * Process device-mapper dependent messages. Messages prefixed with '@'
1541 * are processed by the DM core. All others are delivered to the target.
1542 * Returns a number <= 1 if message was processed by device mapper.
1543 * Returns 2 if message should be delivered to the target.
1544 */
1545static int message_for_md(struct mapped_device *md, unsigned argc, char **argv,
1546 char *result, unsigned maxlen)
1547{
1548 int r;
1549
1550 if (**argv != '@')
1551 return 2; /* no '@' prefix, deliver to target */
1552
1553 if (!strcasecmp(argv[0], "@cancel_deferred_remove")) {
1554 if (argc != 1) {
1555 DMERR("Invalid arguments for @cancel_deferred_remove");
1556 return -EINVAL;
1557 }
1558 return dm_cancel_deferred_remove(md);
1559 }
1560
1561 r = dm_stats_message(md, argc, argv, result, maxlen);
1562 if (r < 2)
1563 return r;
1564
1565 DMERR("Unsupported message sent to DM core: %s", argv[0]);
1566 return -EINVAL;
1567}
1568
1569/*
1570 * Pass a message to the target that's at the supplied device offset.
1571 */
1572static int target_message(struct file *filp, struct dm_ioctl *param, size_t param_size)
1573{
1574 int r, argc;
1575 char **argv;
1576 struct mapped_device *md;
1577 struct dm_table *table;
1578 struct dm_target *ti;
1579 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1580 size_t maxlen;
1581 char *result = get_result_buffer(param, param_size, &maxlen);
1582 int srcu_idx;
1583
1584 md = find_device(param);
1585 if (!md)
1586 return -ENXIO;
1587
1588 if (tmsg < (struct dm_target_msg *) param->data ||
1589 invalid_str(tmsg->message, (void *) param + param_size)) {
1590 DMWARN("Invalid target message parameters.");
1591 r = -EINVAL;
1592 goto out;
1593 }
1594
1595 r = dm_split_args(&argc, &argv, tmsg->message);
1596 if (r) {
1597 DMWARN("Failed to split target message parameters");
1598 goto out;
1599 }
1600
1601 if (!argc) {
1602 DMWARN("Empty message received.");
1603 goto out_argv;
1604 }
1605
1606 r = message_for_md(md, argc, argv, result, maxlen);
1607 if (r <= 1)
1608 goto out_argv;
1609
1610 table = dm_get_live_table(md, &srcu_idx);
1611 if (!table)
1612 goto out_table;
1613
1614 if (dm_deleting_md(md)) {
1615 r = -ENXIO;
1616 goto out_table;
1617 }
1618
1619 ti = dm_table_find_target(table, tmsg->sector);
1620 if (!ti) {
1621 DMWARN("Target message sector outside device.");
1622 r = -EINVAL;
1623 } else if (ti->type->message)
1624 r = ti->type->message(ti, argc, argv, result, maxlen);
1625 else {
1626 DMWARN("Target type does not support messages");
1627 r = -EINVAL;
1628 }
1629
1630 out_table:
1631 dm_put_live_table(md, srcu_idx);
1632 out_argv:
1633 kfree(argv);
1634 out:
1635 if (r >= 0)
1636 __dev_status(md, param);
1637
1638 if (r == 1) {
1639 param->flags |= DM_DATA_OUT_FLAG;
1640 if (dm_message_test_buffer_overflow(result, maxlen))
1641 param->flags |= DM_BUFFER_FULL_FLAG;
1642 else
1643 param->data_size = param->data_start + strlen(result) + 1;
1644 r = 0;
1645 }
1646
1647 dm_put(md);
1648 return r;
1649}
1650
1651/*
1652 * The ioctl parameter block consists of two parts, a dm_ioctl struct
1653 * followed by a data buffer. This flag is set if the second part,
1654 * which has a variable size, is not used by the function processing
1655 * the ioctl.
1656 */
1657#define IOCTL_FLAGS_NO_PARAMS 1
1658#define IOCTL_FLAGS_ISSUE_GLOBAL_EVENT 2
1659
1660/*-----------------------------------------------------------------
1661 * Implementation of open/close/ioctl on the special char
1662 * device.
1663 *---------------------------------------------------------------*/
1664static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags)
1665{
1666 static const struct {
1667 int cmd;
1668 int flags;
1669 ioctl_fn fn;
1670 } _ioctls[] = {
1671 {DM_VERSION_CMD, 0, NULL}, /* version is dealt with elsewhere */
1672 {DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, remove_all},
1673 {DM_LIST_DEVICES_CMD, 0, list_devices},
1674
1675 {DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_create},
1676 {DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_remove},
1677 {DM_DEV_RENAME_CMD, IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_rename},
1678 {DM_DEV_SUSPEND_CMD, IOCTL_FLAGS_NO_PARAMS, dev_suspend},
1679 {DM_DEV_STATUS_CMD, IOCTL_FLAGS_NO_PARAMS, dev_status},
1680 {DM_DEV_WAIT_CMD, 0, dev_wait},
1681
1682 {DM_TABLE_LOAD_CMD, 0, table_load},
1683 {DM_TABLE_CLEAR_CMD, IOCTL_FLAGS_NO_PARAMS, table_clear},
1684 {DM_TABLE_DEPS_CMD, 0, table_deps},
1685 {DM_TABLE_STATUS_CMD, 0, table_status},
1686
1687 {DM_LIST_VERSIONS_CMD, 0, list_versions},
1688
1689 {DM_TARGET_MSG_CMD, 0, target_message},
1690 {DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry},
1691 {DM_DEV_ARM_POLL, IOCTL_FLAGS_NO_PARAMS, dev_arm_poll},
1692 {DM_GET_TARGET_VERSION, 0, get_target_version},
1693 };
1694
1695 if (unlikely(cmd >= ARRAY_SIZE(_ioctls)))
1696 return NULL;
1697
1698 *ioctl_flags = _ioctls[cmd].flags;
1699 return _ioctls[cmd].fn;
1700}
1701
1702/*
1703 * As well as checking the version compatibility this always
1704 * copies the kernel interface version out.
1705 */
1706static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1707{
1708 uint32_t version[3];
1709 int r = 0;
1710
1711 if (copy_from_user(version, user->version, sizeof(version)))
1712 return -EFAULT;
1713
1714 if ((DM_VERSION_MAJOR != version[0]) ||
1715 (DM_VERSION_MINOR < version[1])) {
1716 DMWARN("ioctl interface mismatch: "
1717 "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1718 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1719 DM_VERSION_PATCHLEVEL,
1720 version[0], version[1], version[2], cmd);
1721 r = -EINVAL;
1722 }
1723
1724 /*
1725 * Fill in the kernel version.
1726 */
1727 version[0] = DM_VERSION_MAJOR;
1728 version[1] = DM_VERSION_MINOR;
1729 version[2] = DM_VERSION_PATCHLEVEL;
1730 if (copy_to_user(user->version, version, sizeof(version)))
1731 return -EFAULT;
1732
1733 return r;
1734}
1735
1736#define DM_PARAMS_MALLOC 0x0001 /* Params allocated with kvmalloc() */
1737#define DM_WIPE_BUFFER 0x0010 /* Wipe input buffer before returning from ioctl */
1738
1739static void free_params(struct dm_ioctl *param, size_t param_size, int param_flags)
1740{
1741 if (param_flags & DM_WIPE_BUFFER)
1742 memset(param, 0, param_size);
1743
1744 if (param_flags & DM_PARAMS_MALLOC)
1745 kvfree(param);
1746}
1747
1748static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel,
1749 int ioctl_flags, struct dm_ioctl **param, int *param_flags)
1750{
1751 struct dm_ioctl *dmi;
1752 int secure_data;
1753 const size_t minimum_data_size = offsetof(struct dm_ioctl, data);
1754 unsigned noio_flag;
1755
1756 if (copy_from_user(param_kernel, user, minimum_data_size))
1757 return -EFAULT;
1758
1759 if (param_kernel->data_size < minimum_data_size)
1760 return -EINVAL;
1761
1762 secure_data = param_kernel->flags & DM_SECURE_DATA_FLAG;
1763
1764 *param_flags = secure_data ? DM_WIPE_BUFFER : 0;
1765
1766 if (ioctl_flags & IOCTL_FLAGS_NO_PARAMS) {
1767 dmi = param_kernel;
1768 dmi->data_size = minimum_data_size;
1769 goto data_copied;
1770 }
1771
1772 /*
1773 * Use __GFP_HIGH to avoid low memory issues when a device is
1774 * suspended and the ioctl is needed to resume it.
1775 * Use kmalloc() rather than vmalloc() when we can.
1776 */
1777 dmi = NULL;
1778 noio_flag = memalloc_noio_save();
1779 dmi = kvmalloc(param_kernel->data_size, GFP_KERNEL | __GFP_HIGH);
1780 memalloc_noio_restore(noio_flag);
1781
1782 if (!dmi) {
1783 if (secure_data && clear_user(user, param_kernel->data_size))
1784 return -EFAULT;
1785 return -ENOMEM;
1786 }
1787
1788 *param_flags |= DM_PARAMS_MALLOC;
1789
1790 /* Copy from param_kernel (which was already copied from user) */
1791 memcpy(dmi, param_kernel, minimum_data_size);
1792
1793 if (copy_from_user(&dmi->data, (char __user *)user + minimum_data_size,
1794 param_kernel->data_size - minimum_data_size))
1795 goto bad;
1796data_copied:
1797 /* Wipe the user buffer so we do not return it to userspace */
1798 if (secure_data && clear_user(user, param_kernel->data_size))
1799 goto bad;
1800
1801 *param = dmi;
1802 return 0;
1803
1804bad:
1805 free_params(dmi, param_kernel->data_size, *param_flags);
1806
1807 return -EFAULT;
1808}
1809
1810static int validate_params(uint cmd, struct dm_ioctl *param)
1811{
1812 /* Always clear this flag */
1813 param->flags &= ~DM_BUFFER_FULL_FLAG;
1814 param->flags &= ~DM_UEVENT_GENERATED_FLAG;
1815 param->flags &= ~DM_SECURE_DATA_FLAG;
1816 param->flags &= ~DM_DATA_OUT_FLAG;
1817
1818 /* Ignores parameters */
1819 if (cmd == DM_REMOVE_ALL_CMD ||
1820 cmd == DM_LIST_DEVICES_CMD ||
1821 cmd == DM_LIST_VERSIONS_CMD)
1822 return 0;
1823
1824 if (cmd == DM_DEV_CREATE_CMD) {
1825 if (!*param->name) {
1826 DMWARN("name not supplied when creating device");
1827 return -EINVAL;
1828 }
1829 } else if (*param->uuid && *param->name) {
1830 DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
1831 return -EINVAL;
1832 }
1833
1834 /* Ensure strings are terminated */
1835 param->name[DM_NAME_LEN - 1] = '\0';
1836 param->uuid[DM_UUID_LEN - 1] = '\0';
1837
1838 return 0;
1839}
1840
1841static int ctl_ioctl(struct file *file, uint command, struct dm_ioctl __user *user)
1842{
1843 int r = 0;
1844 int ioctl_flags;
1845 int param_flags;
1846 unsigned int cmd;
1847 struct dm_ioctl *uninitialized_var(param);
1848 ioctl_fn fn = NULL;
1849 size_t input_param_size;
1850 struct dm_ioctl param_kernel;
1851
1852 /* only root can play with this */
1853 if (!capable(CAP_SYS_ADMIN))
1854 return -EACCES;
1855
1856 if (_IOC_TYPE(command) != DM_IOCTL)
1857 return -ENOTTY;
1858
1859 cmd = _IOC_NR(command);
1860
1861 /*
1862 * Check the interface version passed in. This also
1863 * writes out the kernel's interface version.
1864 */
1865 r = check_version(cmd, user);
1866 if (r)
1867 return r;
1868
1869 /*
1870 * Nothing more to do for the version command.
1871 */
1872 if (cmd == DM_VERSION_CMD)
1873 return 0;
1874
1875 fn = lookup_ioctl(cmd, &ioctl_flags);
1876 if (!fn) {
1877 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1878 return -ENOTTY;
1879 }
1880
1881 /*
1882 * Copy the parameters into kernel space.
1883 */
1884 r = copy_params(user, ¶m_kernel, ioctl_flags, ¶m, ¶m_flags);
1885
1886 if (r)
1887 return r;
1888
1889 input_param_size = param->data_size;
1890 r = validate_params(cmd, param);
1891 if (r)
1892 goto out;
1893
1894 param->data_size = offsetof(struct dm_ioctl, data);
1895 r = fn(file, param, input_param_size);
1896
1897 if (unlikely(param->flags & DM_BUFFER_FULL_FLAG) &&
1898 unlikely(ioctl_flags & IOCTL_FLAGS_NO_PARAMS))
1899 DMERR("ioctl %d tried to output some data but has IOCTL_FLAGS_NO_PARAMS set", cmd);
1900
1901 if (!r && ioctl_flags & IOCTL_FLAGS_ISSUE_GLOBAL_EVENT)
1902 dm_issue_global_event();
1903
1904 /*
1905 * Copy the results back to userland.
1906 */
1907 if (!r && copy_to_user(user, param, param->data_size))
1908 r = -EFAULT;
1909
1910out:
1911 free_params(param, input_param_size, param_flags);
1912 return r;
1913}
1914
1915static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
1916{
1917 return (long)ctl_ioctl(file, command, (struct dm_ioctl __user *)u);
1918}
1919
1920#ifdef CONFIG_COMPAT
1921static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
1922{
1923 return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
1924}
1925#else
1926#define dm_compat_ctl_ioctl NULL
1927#endif
1928
1929static int dm_open(struct inode *inode, struct file *filp)
1930{
1931 int r;
1932 struct dm_file *priv;
1933
1934 r = nonseekable_open(inode, filp);
1935 if (unlikely(r))
1936 return r;
1937
1938 priv = filp->private_data = kmalloc(sizeof(struct dm_file), GFP_KERNEL);
1939 if (!priv)
1940 return -ENOMEM;
1941
1942 priv->global_event_nr = atomic_read(&dm_global_event_nr);
1943
1944 return 0;
1945}
1946
1947static int dm_release(struct inode *inode, struct file *filp)
1948{
1949 kfree(filp->private_data);
1950 return 0;
1951}
1952
1953static __poll_t dm_poll(struct file *filp, poll_table *wait)
1954{
1955 struct dm_file *priv = filp->private_data;
1956 __poll_t mask = 0;
1957
1958 poll_wait(filp, &dm_global_eventq, wait);
1959
1960 if ((int)(atomic_read(&dm_global_event_nr) - priv->global_event_nr) > 0)
1961 mask |= EPOLLIN;
1962
1963 return mask;
1964}
1965
1966static const struct file_operations _ctl_fops = {
1967 .open = dm_open,
1968 .release = dm_release,
1969 .poll = dm_poll,
1970 .unlocked_ioctl = dm_ctl_ioctl,
1971 .compat_ioctl = dm_compat_ctl_ioctl,
1972 .owner = THIS_MODULE,
1973 .llseek = noop_llseek,
1974};
1975
1976static struct miscdevice _dm_misc = {
1977 .minor = MAPPER_CTRL_MINOR,
1978 .name = DM_NAME,
1979 .nodename = DM_DIR "/" DM_CONTROL_NODE,
1980 .fops = &_ctl_fops
1981};
1982
1983MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
1984MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
1985
1986/*
1987 * Create misc character device and link to DM_DIR/control.
1988 */
1989int __init dm_interface_init(void)
1990{
1991 int r;
1992
1993 r = dm_hash_init();
1994 if (r)
1995 return r;
1996
1997 r = misc_register(&_dm_misc);
1998 if (r) {
1999 DMERR("misc_register failed for control device");
2000 dm_hash_exit();
2001 return r;
2002 }
2003
2004 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
2005 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
2006 DM_DRIVER_EMAIL);
2007 return 0;
2008}
2009
2010void dm_interface_exit(void)
2011{
2012 misc_deregister(&_dm_misc);
2013 dm_hash_exit();
2014}
2015
2016/**
2017 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
2018 * @md: Pointer to mapped_device
2019 * @name: Buffer (size DM_NAME_LEN) for name
2020 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
2021 */
2022int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
2023{
2024 int r = 0;
2025 struct hash_cell *hc;
2026
2027 if (!md)
2028 return -ENXIO;
2029
2030 mutex_lock(&dm_hash_cells_mutex);
2031 hc = dm_get_mdptr(md);
2032 if (!hc || hc->md != md) {
2033 r = -ENXIO;
2034 goto out;
2035 }
2036
2037 if (name)
2038 strcpy(name, hc->name);
2039 if (uuid)
2040 strcpy(uuid, hc->uuid ? : "");
2041
2042out:
2043 mutex_unlock(&dm_hash_cells_mutex);
2044
2045 return r;
2046}
2047
2048
2049/**
2050 * dm_early_create - create a mapped device in early boot.
2051 *
2052 * @dmi: Contains main information of the device mapping to be created.
2053 * @spec_array: array of pointers to struct dm_target_spec. Describes the
2054 * mapping table of the device.
2055 * @target_params_array: array of strings with the parameters to a specific
2056 * target.
2057 *
2058 * Instead of having the struct dm_target_spec and the parameters for every
2059 * target embedded at the end of struct dm_ioctl (as performed in a normal
2060 * ioctl), pass them as arguments, so the caller doesn't need to serialize them.
2061 * The size of the spec_array and target_params_array is given by
2062 * @dmi->target_count.
2063 * This function is supposed to be called in early boot, so locking mechanisms
2064 * to protect against concurrent loads are not required.
2065 */
2066int __init dm_early_create(struct dm_ioctl *dmi,
2067 struct dm_target_spec **spec_array,
2068 char **target_params_array)
2069{
2070 int r, m = DM_ANY_MINOR;
2071 struct dm_table *t, *old_map;
2072 struct mapped_device *md;
2073 unsigned int i;
2074
2075 if (!dmi->target_count)
2076 return -EINVAL;
2077
2078 r = check_name(dmi->name);
2079 if (r)
2080 return r;
2081
2082 if (dmi->flags & DM_PERSISTENT_DEV_FLAG)
2083 m = MINOR(huge_decode_dev(dmi->dev));
2084
2085 /* alloc dm device */
2086 r = dm_create(m, &md);
2087 if (r)
2088 return r;
2089
2090 /* hash insert */
2091 r = dm_hash_insert(dmi->name, *dmi->uuid ? dmi->uuid : NULL, md);
2092 if (r)
2093 goto err_destroy_dm;
2094
2095 /* alloc table */
2096 r = dm_table_create(&t, get_mode(dmi), dmi->target_count, md);
2097 if (r)
2098 goto err_hash_remove;
2099
2100 /* add targets */
2101 for (i = 0; i < dmi->target_count; i++) {
2102 r = dm_table_add_target(t, spec_array[i]->target_type,
2103 (sector_t) spec_array[i]->sector_start,
2104 (sector_t) spec_array[i]->length,
2105 target_params_array[i]);
2106 if (r) {
2107 DMWARN("error adding target to table");
2108 goto err_destroy_table;
2109 }
2110 }
2111
2112 /* finish table */
2113 r = dm_table_complete(t);
2114 if (r)
2115 goto err_destroy_table;
2116
2117 md->type = dm_table_get_type(t);
2118 /* setup md->queue to reflect md's type (may block) */
2119 r = dm_setup_md_queue(md, t);
2120 if (r) {
2121 DMWARN("unable to set up device queue for new table.");
2122 goto err_destroy_table;
2123 }
2124
2125 /* Set new map */
2126 dm_suspend(md, 0);
2127 old_map = dm_swap_table(md, t);
2128 if (IS_ERR(old_map)) {
2129 r = PTR_ERR(old_map);
2130 goto err_destroy_table;
2131 }
2132 set_disk_ro(dm_disk(md), !!(dmi->flags & DM_READONLY_FLAG));
2133
2134 /* resume device */
2135 r = dm_resume(md);
2136 if (r)
2137 goto err_destroy_table;
2138
2139 DMINFO("%s (%s) is ready", md->disk->disk_name, dmi->name);
2140 dm_put(md);
2141 return 0;
2142
2143err_destroy_table:
2144 dm_table_destroy(t);
2145err_hash_remove:
2146 (void) __hash_remove(__get_name_cell(dmi->name));
2147 /* release reference from __get_name_cell */
2148 dm_put(md);
2149err_destroy_dm:
2150 dm_put(md);
2151 dm_destroy(md);
2152 return r;
2153}