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Merge tag 'nfs-for-3.13-2' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
[linux/fpc-iii.git] / drivers / md / dm-ioctl.c
blob51521429fb59d01ea65e8d1243a1151272f9beca
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 *---------------------------------------------------------------*/
29 struct hash_cell {
30 struct list_head name_list;
31 struct list_head uuid_list;
32
33 char *name;
34 char *uuid;
35 struct mapped_device *md;
36 struct dm_table *new_map;
37 };
38
39 /*
40 * A dummy definition to make RCU happy.
41 * struct dm_table should never be dereferenced in this file.
42 */
43 struct dm_table {
44 int undefined__;
45 };
46
47 struct vers_iter {
48 size_t param_size;
49 struct dm_target_versions *vers, *old_vers;
50 char *end;
51 uint32_t flags;
52 };
53
54
55 #define NUM_BUCKETS 64
56 #define MASK_BUCKETS (NUM_BUCKETS - 1)
57 static struct list_head _name_buckets[NUM_BUCKETS];
58 static struct list_head _uuid_buckets[NUM_BUCKETS];
59
60 static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred);
61
62 /*
63 * Guards access to both hash tables.
64 */
65 static DECLARE_RWSEM(_hash_lock);
66
67 /*
68 * Protects use of mdptr to obtain hash cell name and uuid from mapped device.
69 */
70 static DEFINE_MUTEX(dm_hash_cells_mutex);
71
72 static void init_buckets(struct list_head *buckets)
73 {
74 unsigned int i;
75
76 for (i = 0; i < NUM_BUCKETS; i++)
77 INIT_LIST_HEAD(buckets + i);
78 }
79
80 static int dm_hash_init(void)
81 {
82 init_buckets(_name_buckets);
83 init_buckets(_uuid_buckets);
84 return 0;
85 }
86
87 static void dm_hash_exit(void)
88 {
89 dm_hash_remove_all(false, false, false);
90 }
91
92 /*-----------------------------------------------------------------
93 * Hash function:
94 * We're not really concerned with the str hash function being
95 * fast since it's only used by the ioctl interface.
96 *---------------------------------------------------------------*/
97 static unsigned int hash_str(const char *str)
98 {
99 const unsigned int hash_mult = 2654435387U;
100 unsigned int h = 0;
101
102 while (*str)
103 h = (h + (unsigned int) *str++) * hash_mult;
104
105 return h & MASK_BUCKETS;
106 }
107
108 /*-----------------------------------------------------------------
109 * Code for looking up a device by name
110 *---------------------------------------------------------------*/
111 static struct hash_cell *__get_name_cell(const char *str)
112 {
113 struct hash_cell *hc;
114 unsigned int h = hash_str(str);
115
116 list_for_each_entry (hc, _name_buckets + h, name_list)
117 if (!strcmp(hc->name, str)) {
118 dm_get(hc->md);
119 return hc;
120 }
121
122 return NULL;
123 }
124
125 static struct hash_cell *__get_uuid_cell(const char *str)
126 {
127 struct hash_cell *hc;
128 unsigned int h = hash_str(str);
129
130 list_for_each_entry (hc, _uuid_buckets + h, uuid_list)
131 if (!strcmp(hc->uuid, str)) {
132 dm_get(hc->md);
133 return hc;
134 }
135
136 return NULL;
137 }
138
139 static struct hash_cell *__get_dev_cell(uint64_t dev)
140 {
141 struct mapped_device *md;
142 struct hash_cell *hc;
143
144 md = dm_get_md(huge_decode_dev(dev));
145 if (!md)
146 return NULL;
147
148 hc = dm_get_mdptr(md);
149 if (!hc) {
150 dm_put(md);
151 return NULL;
152 }
153
154 return hc;
155 }
156
157 /*-----------------------------------------------------------------
158 * Inserting, removing and renaming a device.
159 *---------------------------------------------------------------*/
160 static struct hash_cell *alloc_cell(const char *name, const char *uuid,
161 struct mapped_device *md)
162 {
163 struct hash_cell *hc;
164
165 hc = kmalloc(sizeof(*hc), GFP_KERNEL);
166 if (!hc)
167 return NULL;
168
169 hc->name = kstrdup(name, GFP_KERNEL);
170 if (!hc->name) {
171 kfree(hc);
172 return NULL;
173 }
174
175 if (!uuid)
176 hc->uuid = NULL;
177
178 else {
179 hc->uuid = kstrdup(uuid, GFP_KERNEL);
180 if (!hc->uuid) {
181 kfree(hc->name);
182 kfree(hc);
183 return NULL;
184 }
185 }
186
187 INIT_LIST_HEAD(&hc->name_list);
188 INIT_LIST_HEAD(&hc->uuid_list);
189 hc->md = md;
190 hc->new_map = NULL;
191 return hc;
192 }
193
194 static void free_cell(struct hash_cell *hc)
195 {
196 if (hc) {
197 kfree(hc->name);
198 kfree(hc->uuid);
199 kfree(hc);
200 }
201 }
202
203 /*
204 * The kdev_t and uuid of a device can never change once it is
205 * initially inserted.
206 */
207 static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
208 {
209 struct hash_cell *cell, *hc;
210
211 /*
212 * Allocate the new cells.
213 */
214 cell = alloc_cell(name, uuid, md);
215 if (!cell)
216 return -ENOMEM;
217
218 /*
219 * Insert the cell into both hash tables.
220 */
221 down_write(&_hash_lock);
222 hc = __get_name_cell(name);
223 if (hc) {
224 dm_put(hc->md);
225 goto bad;
226 }
227
228 list_add(&cell->name_list, _name_buckets + hash_str(name));
229
230 if (uuid) {
231 hc = __get_uuid_cell(uuid);
232 if (hc) {
233 list_del(&cell->name_list);
234 dm_put(hc->md);
235 goto bad;
236 }
237 list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
238 }
239 dm_get(md);
240 mutex_lock(&dm_hash_cells_mutex);
241 dm_set_mdptr(md, cell);
242 mutex_unlock(&dm_hash_cells_mutex);
243 up_write(&_hash_lock);
244
245 return 0;
246
247 bad:
248 up_write(&_hash_lock);
249 free_cell(cell);
250 return -EBUSY;
251 }
252
253 static struct dm_table *__hash_remove(struct hash_cell *hc)
254 {
255 struct dm_table *table;
256 int srcu_idx;
257
258 /* remove from the dev hash */
259 list_del(&hc->uuid_list);
260 list_del(&hc->name_list);
261 mutex_lock(&dm_hash_cells_mutex);
262 dm_set_mdptr(hc->md, NULL);
263 mutex_unlock(&dm_hash_cells_mutex);
264
265 table = dm_get_live_table(hc->md, &srcu_idx);
266 if (table)
267 dm_table_event(table);
268 dm_put_live_table(hc->md, srcu_idx);
269
270 table = NULL;
271 if (hc->new_map)
272 table = hc->new_map;
273 dm_put(hc->md);
274 free_cell(hc);
275
276 return table;
277 }
278
279 static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred)
280 {
281 int i, dev_skipped;
282 struct hash_cell *hc;
283 struct mapped_device *md;
284 struct dm_table *t;
285
286 retry:
287 dev_skipped = 0;
288
289 down_write(&_hash_lock);
290
291 for (i = 0; i < NUM_BUCKETS; i++) {
292 list_for_each_entry(hc, _name_buckets + i, name_list) {
293 md = hc->md;
294 dm_get(md);
295
296 if (keep_open_devices &&
297 dm_lock_for_deletion(md, mark_deferred, only_deferred)) {
298 dm_put(md);
299 dev_skipped++;
300 continue;
301 }
302
303 t = __hash_remove(hc);
304
305 up_write(&_hash_lock);
306
307 if (t) {
308 dm_sync_table(md);
309 dm_table_destroy(t);
310 }
311 dm_put(md);
312 if (likely(keep_open_devices))
313 dm_destroy(md);
314 else
315 dm_destroy_immediate(md);
316
317 /*
318 * Some mapped devices may be using other mapped
319 * devices, so repeat until we make no further
320 * progress. If a new mapped device is created
321 * here it will also get removed.
322 */
323 goto retry;
324 }
325 }
326
327 up_write(&_hash_lock);
328
329 if (dev_skipped)
330 DMWARN("remove_all left %d open device(s)", dev_skipped);
331 }
332
333 /*
334 * Set the uuid of a hash_cell that isn't already set.
335 */
336 static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
337 {
338 mutex_lock(&dm_hash_cells_mutex);
339 hc->uuid = new_uuid;
340 mutex_unlock(&dm_hash_cells_mutex);
341
342 list_add(&hc->uuid_list, _uuid_buckets + hash_str(new_uuid));
343 }
344
345 /*
346 * Changes the name of a hash_cell and returns the old name for
347 * the caller to free.
348 */
349 static char *__change_cell_name(struct hash_cell *hc, char *new_name)
350 {
351 char *old_name;
352
353 /*
354 * Rename and move the name cell.
355 */
356 list_del(&hc->name_list);
357 old_name = hc->name;
358
359 mutex_lock(&dm_hash_cells_mutex);
360 hc->name = new_name;
361 mutex_unlock(&dm_hash_cells_mutex);
362
363 list_add(&hc->name_list, _name_buckets + hash_str(new_name));
364
365 return old_name;
366 }
367
368 static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
369 const char *new)
370 {
371 char *new_data, *old_name = NULL;
372 struct hash_cell *hc;
373 struct dm_table *table;
374 struct mapped_device *md;
375 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
376 int srcu_idx;
377
378 /*
379 * duplicate new.
380 */
381 new_data = kstrdup(new, GFP_KERNEL);
382 if (!new_data)
383 return ERR_PTR(-ENOMEM);
384
385 down_write(&_hash_lock);
386
387 /*
388 * Is new free ?
389 */
390 if (change_uuid)
391 hc = __get_uuid_cell(new);
392 else
393 hc = __get_name_cell(new);
394
395 if (hc) {
396 DMWARN("Unable to change %s on mapped device %s to one that "
397 "already exists: %s",
398 change_uuid ? "uuid" : "name",
399 param->name, new);
400 dm_put(hc->md);
401 up_write(&_hash_lock);
402 kfree(new_data);
403 return ERR_PTR(-EBUSY);
404 }
405
406 /*
407 * Is there such a device as 'old' ?
408 */
409 hc = __get_name_cell(param->name);
410 if (!hc) {
411 DMWARN("Unable to rename non-existent device, %s to %s%s",
412 param->name, change_uuid ? "uuid " : "", new);
413 up_write(&_hash_lock);
414 kfree(new_data);
415 return ERR_PTR(-ENXIO);
416 }
417
418 /*
419 * Does this device already have a uuid?
420 */
421 if (change_uuid && hc->uuid) {
422 DMWARN("Unable to change uuid of mapped device %s to %s "
423 "because uuid is already set to %s",
424 param->name, new, hc->uuid);
425 dm_put(hc->md);
426 up_write(&_hash_lock);
427 kfree(new_data);
428 return ERR_PTR(-EINVAL);
429 }
430
431 if (change_uuid)
432 __set_cell_uuid(hc, new_data);
433 else
434 old_name = __change_cell_name(hc, new_data);
435
436 /*
437 * Wake up any dm event waiters.
438 */
439 table = dm_get_live_table(hc->md, &srcu_idx);
440 if (table)
441 dm_table_event(table);
442 dm_put_live_table(hc->md, srcu_idx);
443
444 if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr))
445 param->flags |= DM_UEVENT_GENERATED_FLAG;
446
447 md = hc->md;
448 up_write(&_hash_lock);
449 kfree(old_name);
450
451 return md;
452 }
453
454 void dm_deferred_remove(void)
455 {
456 dm_hash_remove_all(true, false, true);
457 }
458
459 /*-----------------------------------------------------------------
460 * Implementation of the ioctl commands
461 *---------------------------------------------------------------*/
462 /*
463 * All the ioctl commands get dispatched to functions with this
464 * prototype.
465 */
466 typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size);
467
468 static int remove_all(struct dm_ioctl *param, size_t param_size)
469 {
470 dm_hash_remove_all(true, !!(param->flags & DM_DEFERRED_REMOVE), false);
471 param->data_size = 0;
472 return 0;
473 }
474
475 /*
476 * Round up the ptr to an 8-byte boundary.
477 */
478 #define ALIGN_MASK 7
479 static inline void *align_ptr(void *ptr)
480 {
481 return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK);
482 }
483
484 /*
485 * Retrieves the data payload buffer from an already allocated
486 * struct dm_ioctl.
487 */
488 static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
489 size_t *len)
490 {
491 param->data_start = align_ptr(param + 1) - (void *) param;
492
493 if (param->data_start < param_size)
494 *len = param_size - param->data_start;
495 else
496 *len = 0;
497
498 return ((void *) param) + param->data_start;
499 }
500
501 static int list_devices(struct dm_ioctl *param, size_t param_size)
502 {
503 unsigned int i;
504 struct hash_cell *hc;
505 size_t len, needed = 0;
506 struct gendisk *disk;
507 struct dm_name_list *nl, *old_nl = NULL;
508
509 down_write(&_hash_lock);
510
511 /*
512 * Loop through all the devices working out how much
513 * space we need.
514 */
515 for (i = 0; i < NUM_BUCKETS; i++) {
516 list_for_each_entry (hc, _name_buckets + i, name_list) {
517 needed += sizeof(struct dm_name_list);
518 needed += strlen(hc->name) + 1;
519 needed += ALIGN_MASK;
520 }
521 }
522
523 /*
524 * Grab our output buffer.
525 */
526 nl = get_result_buffer(param, param_size, &len);
527 if (len < needed) {
528 param->flags |= DM_BUFFER_FULL_FLAG;
529 goto out;
530 }
531 param->data_size = param->data_start + needed;
532
533 nl->dev = 0; /* Flags no data */
534
535 /*
536 * Now loop through filling out the names.
537 */
538 for (i = 0; i < NUM_BUCKETS; i++) {
539 list_for_each_entry (hc, _name_buckets + i, name_list) {
540 if (old_nl)
541 old_nl->next = (uint32_t) ((void *) nl -
542 (void *) old_nl);
543 disk = dm_disk(hc->md);
544 nl->dev = huge_encode_dev(disk_devt(disk));
545 nl->next = 0;
546 strcpy(nl->name, hc->name);
547
548 old_nl = nl;
549 nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1);
550 }
551 }
552
553 out:
554 up_write(&_hash_lock);
555 return 0;
556 }
557
558 static void list_version_get_needed(struct target_type *tt, void *needed_param)
559 {
560 size_t *needed = needed_param;
561
562 *needed += sizeof(struct dm_target_versions);
563 *needed += strlen(tt->name);
564 *needed += ALIGN_MASK;
565 }
566
567 static void list_version_get_info(struct target_type *tt, void *param)
568 {
569 struct vers_iter *info = param;
570
571 /* Check space - it might have changed since the first iteration */
572 if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
573 info->end) {
574
575 info->flags = DM_BUFFER_FULL_FLAG;
576 return;
577 }
578
579 if (info->old_vers)
580 info->old_vers->next = (uint32_t) ((void *)info->vers -
581 (void *)info->old_vers);
582 info->vers->version[0] = tt->version[0];
583 info->vers->version[1] = tt->version[1];
584 info->vers->version[2] = tt->version[2];
585 info->vers->next = 0;
586 strcpy(info->vers->name, tt->name);
587
588 info->old_vers = info->vers;
589 info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
590 }
591
592 static int list_versions(struct dm_ioctl *param, size_t param_size)
593 {
594 size_t len, needed = 0;
595 struct dm_target_versions *vers;
596 struct vers_iter iter_info;
597
598 /*
599 * Loop through all the devices working out how much
600 * space we need.
601 */
602 dm_target_iterate(list_version_get_needed, &needed);
603
604 /*
605 * Grab our output buffer.
606 */
607 vers = get_result_buffer(param, param_size, &len);
608 if (len < needed) {
609 param->flags |= DM_BUFFER_FULL_FLAG;
610 goto out;
611 }
612 param->data_size = param->data_start + needed;
613
614 iter_info.param_size = param_size;
615 iter_info.old_vers = NULL;
616 iter_info.vers = vers;
617 iter_info.flags = 0;
618 iter_info.end = (char *)vers+len;
619
620 /*
621 * Now loop through filling out the names & versions.
622 */
623 dm_target_iterate(list_version_get_info, &iter_info);
624 param->flags |= iter_info.flags;
625
626 out:
627 return 0;
628 }
629
630 static int check_name(const char *name)
631 {
632 if (strchr(name, '/')) {
633 DMWARN("invalid device name");
634 return -EINVAL;
635 }
636
637 return 0;
638 }
639
640 /*
641 * On successful return, the caller must not attempt to acquire
642 * _hash_lock without first calling dm_table_put, because dm_table_destroy
643 * waits for this dm_table_put and could be called under this lock.
644 */
645 static struct dm_table *dm_get_inactive_table(struct mapped_device *md, int *srcu_idx)
646 {
647 struct hash_cell *hc;
648 struct dm_table *table = NULL;
649
650 /* increment rcu count, we don't care about the table pointer */
651 dm_get_live_table(md, srcu_idx);
652
653 down_read(&_hash_lock);
654 hc = dm_get_mdptr(md);
655 if (!hc || hc->md != md) {
656 DMWARN("device has been removed from the dev hash table.");
657 goto out;
658 }
659
660 table = hc->new_map;
661
662 out:
663 up_read(&_hash_lock);
664
665 return table;
666 }
667
668 static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
669 struct dm_ioctl *param,
670 int *srcu_idx)
671 {
672 return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
673 dm_get_inactive_table(md, srcu_idx) : dm_get_live_table(md, srcu_idx);
674 }
675
676 /*
677 * Fills in a dm_ioctl structure, ready for sending back to
678 * userland.
679 */
680 static void __dev_status(struct mapped_device *md, struct dm_ioctl *param)
681 {
682 struct gendisk *disk = dm_disk(md);
683 struct dm_table *table;
684 int srcu_idx;
685
686 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
687 DM_ACTIVE_PRESENT_FLAG);
688
689 if (dm_suspended_md(md))
690 param->flags |= DM_SUSPEND_FLAG;
691
692 if (dm_test_deferred_remove_flag(md))
693 param->flags |= DM_DEFERRED_REMOVE;
694
695 param->dev = huge_encode_dev(disk_devt(disk));
696
697 /*
698 * Yes, this will be out of date by the time it gets back
699 * to userland, but it is still very useful for
700 * debugging.
701 */
702 param->open_count = dm_open_count(md);
703
704 param->event_nr = dm_get_event_nr(md);
705 param->target_count = 0;
706
707 table = dm_get_live_table(md, &srcu_idx);
708 if (table) {
709 if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
710 if (get_disk_ro(disk))
711 param->flags |= DM_READONLY_FLAG;
712 param->target_count = dm_table_get_num_targets(table);
713 }
714
715 param->flags |= DM_ACTIVE_PRESENT_FLAG;
716 }
717 dm_put_live_table(md, srcu_idx);
718
719 if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
720 int srcu_idx;
721 table = dm_get_inactive_table(md, &srcu_idx);
722 if (table) {
723 if (!(dm_table_get_mode(table) & FMODE_WRITE))
724 param->flags |= DM_READONLY_FLAG;
725 param->target_count = dm_table_get_num_targets(table);
726 }
727 dm_put_live_table(md, srcu_idx);
728 }
729 }
730
731 static int dev_create(struct dm_ioctl *param, size_t param_size)
732 {
733 int r, m = DM_ANY_MINOR;
734 struct mapped_device *md;
735
736 r = check_name(param->name);
737 if (r)
738 return r;
739
740 if (param->flags & DM_PERSISTENT_DEV_FLAG)
741 m = MINOR(huge_decode_dev(param->dev));
742
743 r = dm_create(m, &md);
744 if (r)
745 return r;
746
747 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
748 if (r) {
749 dm_put(md);
750 dm_destroy(md);
751 return r;
752 }
753
754 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
755
756 __dev_status(md, param);
757
758 dm_put(md);
759
760 return 0;
761 }
762
763 /*
764 * Always use UUID for lookups if it's present, otherwise use name or dev.
765 */
766 static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
767 {
768 struct hash_cell *hc = NULL;
769
770 if (*param->uuid) {
771 if (*param->name || param->dev)
772 return NULL;
773
774 hc = __get_uuid_cell(param->uuid);
775 if (!hc)
776 return NULL;
777 } else if (*param->name) {
778 if (param->dev)
779 return NULL;
780
781 hc = __get_name_cell(param->name);
782 if (!hc)
783 return NULL;
784 } else if (param->dev) {
785 hc = __get_dev_cell(param->dev);
786 if (!hc)
787 return NULL;
788 } else
789 return NULL;
790
791 /*
792 * Sneakily write in both the name and the uuid
793 * while we have the cell.
794 */
795 strlcpy(param->name, hc->name, sizeof(param->name));
796 if (hc->uuid)
797 strlcpy(param->uuid, hc->uuid, sizeof(param->uuid));
798 else
799 param->uuid[0] = '\0';
800
801 if (hc->new_map)
802 param->flags |= DM_INACTIVE_PRESENT_FLAG;
803 else
804 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
805
806 return hc;
807 }
808
809 static struct mapped_device *find_device(struct dm_ioctl *param)
810 {
811 struct hash_cell *hc;
812 struct mapped_device *md = NULL;
813
814 down_read(&_hash_lock);
815 hc = __find_device_hash_cell(param);
816 if (hc)
817 md = hc->md;
818 up_read(&_hash_lock);
819
820 return md;
821 }
822
823 static int dev_remove(struct dm_ioctl *param, size_t param_size)
824 {
825 struct hash_cell *hc;
826 struct mapped_device *md;
827 int r;
828 struct dm_table *t;
829
830 down_write(&_hash_lock);
831 hc = __find_device_hash_cell(param);
832
833 if (!hc) {
834 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
835 up_write(&_hash_lock);
836 return -ENXIO;
837 }
838
839 md = hc->md;
840
841 /*
842 * Ensure the device is not open and nothing further can open it.
843 */
844 r = dm_lock_for_deletion(md, !!(param->flags & DM_DEFERRED_REMOVE), false);
845 if (r) {
846 if (r == -EBUSY && param->flags & DM_DEFERRED_REMOVE) {
847 up_write(&_hash_lock);
848 dm_put(md);
849 return 0;
850 }
851 DMDEBUG_LIMIT("unable to remove open device %s", hc->name);
852 up_write(&_hash_lock);
853 dm_put(md);
854 return r;
855 }
856
857 t = __hash_remove(hc);
858 up_write(&_hash_lock);
859
860 if (t) {
861 dm_sync_table(md);
862 dm_table_destroy(t);
863 }
864
865 param->flags &= ~DM_DEFERRED_REMOVE;
866
867 if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr))
868 param->flags |= DM_UEVENT_GENERATED_FLAG;
869
870 dm_put(md);
871 dm_destroy(md);
872 return 0;
873 }
874
875 /*
876 * Check a string doesn't overrun the chunk of
877 * memory we copied from userland.
878 */
879 static int invalid_str(char *str, void *end)
880 {
881 while ((void *) str < end)
882 if (!*str++)
883 return 0;
884
885 return -EINVAL;
886 }
887
888 static int dev_rename(struct dm_ioctl *param, size_t param_size)
889 {
890 int r;
891 char *new_data = (char *) param + param->data_start;
892 struct mapped_device *md;
893 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
894
895 if (new_data < param->data ||
896 invalid_str(new_data, (void *) param + param_size) || !*new_data ||
897 strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
898 DMWARN("Invalid new mapped device name or uuid string supplied.");
899 return -EINVAL;
900 }
901
902 if (!change_uuid) {
903 r = check_name(new_data);
904 if (r)
905 return r;
906 }
907
908 md = dm_hash_rename(param, new_data);
909 if (IS_ERR(md))
910 return PTR_ERR(md);
911
912 __dev_status(md, param);
913 dm_put(md);
914
915 return 0;
916 }
917
918 static int dev_set_geometry(struct dm_ioctl *param, size_t param_size)
919 {
920 int r = -EINVAL, x;
921 struct mapped_device *md;
922 struct hd_geometry geometry;
923 unsigned long indata[4];
924 char *geostr = (char *) param + param->data_start;
925 char dummy;
926
927 md = find_device(param);
928 if (!md)
929 return -ENXIO;
930
931 if (geostr < param->data ||
932 invalid_str(geostr, (void *) param + param_size)) {
933 DMWARN("Invalid geometry supplied.");
934 goto out;
935 }
936
937 x = sscanf(geostr, "%lu %lu %lu %lu%c", indata,
938 indata + 1, indata + 2, indata + 3, &dummy);
939
940 if (x != 4) {
941 DMWARN("Unable to interpret geometry settings.");
942 goto out;
943 }
944
945 if (indata[0] > 65535 || indata[1] > 255 ||
946 indata[2] > 255 || indata[3] > ULONG_MAX) {
947 DMWARN("Geometry exceeds range limits.");
948 goto out;
949 }
950
951 geometry.cylinders = indata[0];
952 geometry.heads = indata[1];
953 geometry.sectors = indata[2];
954 geometry.start = indata[3];
955
956 r = dm_set_geometry(md, &geometry);
957
958 param->data_size = 0;
959
960 out:
961 dm_put(md);
962 return r;
963 }
964
965 static int do_suspend(struct dm_ioctl *param)
966 {
967 int r = 0;
968 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
969 struct mapped_device *md;
970
971 md = find_device(param);
972 if (!md)
973 return -ENXIO;
974
975 if (param->flags & DM_SKIP_LOCKFS_FLAG)
976 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
977 if (param->flags & DM_NOFLUSH_FLAG)
978 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
979
980 if (!dm_suspended_md(md)) {
981 r = dm_suspend(md, suspend_flags);
982 if (r)
983 goto out;
984 }
985
986 __dev_status(md, param);
987
988 out:
989 dm_put(md);
990
991 return r;
992 }
993
994 static int do_resume(struct dm_ioctl *param)
995 {
996 int r = 0;
997 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
998 struct hash_cell *hc;
999 struct mapped_device *md;
1000 struct dm_table *new_map, *old_map = NULL;
1001
1002 down_write(&_hash_lock);
1003
1004 hc = __find_device_hash_cell(param);
1005 if (!hc) {
1006 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1007 up_write(&_hash_lock);
1008 return -ENXIO;
1009 }
1010
1011 md = hc->md;
1012
1013 new_map = hc->new_map;
1014 hc->new_map = NULL;
1015 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1016
1017 up_write(&_hash_lock);
1018
1019 /* Do we need to load a new map ? */
1020 if (new_map) {
1021 /* Suspend if it isn't already suspended */
1022 if (param->flags & DM_SKIP_LOCKFS_FLAG)
1023 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
1024 if (param->flags & DM_NOFLUSH_FLAG)
1025 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
1026 if (!dm_suspended_md(md))
1027 dm_suspend(md, suspend_flags);
1028
1029 old_map = dm_swap_table(md, new_map);
1030 if (IS_ERR(old_map)) {
1031 dm_sync_table(md);
1032 dm_table_destroy(new_map);
1033 dm_put(md);
1034 return PTR_ERR(old_map);
1035 }
1036
1037 if (dm_table_get_mode(new_map) & FMODE_WRITE)
1038 set_disk_ro(dm_disk(md), 0);
1039 else
1040 set_disk_ro(dm_disk(md), 1);
1041 }
1042
1043 if (dm_suspended_md(md)) {
1044 r = dm_resume(md);
1045 if (!r && !dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr))
1046 param->flags |= DM_UEVENT_GENERATED_FLAG;
1047 }
1048
1049 /*
1050 * Since dm_swap_table synchronizes RCU, nobody should be in
1051 * read-side critical section already.
1052 */
1053 if (old_map)
1054 dm_table_destroy(old_map);
1055
1056 if (!r)
1057 __dev_status(md, param);
1058
1059 dm_put(md);
1060 return r;
1061 }
1062
1063 /*
1064 * Set or unset the suspension state of a device.
1065 * If the device already is in the requested state we just return its status.
1066 */
1067 static int dev_suspend(struct dm_ioctl *param, size_t param_size)
1068 {
1069 if (param->flags & DM_SUSPEND_FLAG)
1070 return do_suspend(param);
1071
1072 return do_resume(param);
1073 }
1074
1075 /*
1076 * Copies device info back to user space, used by
1077 * the create and info ioctls.
1078 */
1079 static int dev_status(struct dm_ioctl *param, size_t param_size)
1080 {
1081 struct mapped_device *md;
1082
1083 md = find_device(param);
1084 if (!md)
1085 return -ENXIO;
1086
1087 __dev_status(md, param);
1088 dm_put(md);
1089
1090 return 0;
1091 }
1092
1093 /*
1094 * Build up the status struct for each target
1095 */
1096 static void retrieve_status(struct dm_table *table,
1097 struct dm_ioctl *param, size_t param_size)
1098 {
1099 unsigned int i, num_targets;
1100 struct dm_target_spec *spec;
1101 char *outbuf, *outptr;
1102 status_type_t type;
1103 size_t remaining, len, used = 0;
1104 unsigned status_flags = 0;
1105
1106 outptr = outbuf = get_result_buffer(param, param_size, &len);
1107
1108 if (param->flags & DM_STATUS_TABLE_FLAG)
1109 type = STATUSTYPE_TABLE;
1110 else
1111 type = STATUSTYPE_INFO;
1112
1113 /* Get all the target info */
1114 num_targets = dm_table_get_num_targets(table);
1115 for (i = 0; i < num_targets; i++) {
1116 struct dm_target *ti = dm_table_get_target(table, i);
1117 size_t l;
1118
1119 remaining = len - (outptr - outbuf);
1120 if (remaining <= sizeof(struct dm_target_spec)) {
1121 param->flags |= DM_BUFFER_FULL_FLAG;
1122 break;
1123 }
1124
1125 spec = (struct dm_target_spec *) outptr;
1126
1127 spec->status = 0;
1128 spec->sector_start = ti->begin;
1129 spec->length = ti->len;
1130 strncpy(spec->target_type, ti->type->name,
1131 sizeof(spec->target_type));
1132
1133 outptr += sizeof(struct dm_target_spec);
1134 remaining = len - (outptr - outbuf);
1135 if (remaining <= 0) {
1136 param->flags |= DM_BUFFER_FULL_FLAG;
1137 break;
1138 }
1139
1140 /* Get the status/table string from the target driver */
1141 if (ti->type->status) {
1142 if (param->flags & DM_NOFLUSH_FLAG)
1143 status_flags |= DM_STATUS_NOFLUSH_FLAG;
1144 ti->type->status(ti, type, status_flags, outptr, remaining);
1145 } else
1146 outptr[0] = '\0';
1147
1148 l = strlen(outptr) + 1;
1149 if (l == remaining) {
1150 param->flags |= DM_BUFFER_FULL_FLAG;
1151 break;
1152 }
1153
1154 outptr += l;
1155 used = param->data_start + (outptr - outbuf);
1156
1157 outptr = align_ptr(outptr);
1158 spec->next = outptr - outbuf;
1159 }
1160
1161 if (used)
1162 param->data_size = used;
1163
1164 param->target_count = num_targets;
1165 }
1166
1167 /*
1168 * Wait for a device to report an event
1169 */
1170 static int dev_wait(struct dm_ioctl *param, size_t param_size)
1171 {
1172 int r = 0;
1173 struct mapped_device *md;
1174 struct dm_table *table;
1175 int srcu_idx;
1176
1177 md = find_device(param);
1178 if (!md)
1179 return -ENXIO;
1180
1181 /*
1182 * Wait for a notification event
1183 */
1184 if (dm_wait_event(md, param->event_nr)) {
1185 r = -ERESTARTSYS;
1186 goto out;
1187 }
1188
1189 /*
1190 * The userland program is going to want to know what
1191 * changed to trigger the event, so we may as well tell
1192 * him and save an ioctl.
1193 */
1194 __dev_status(md, param);
1195
1196 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1197 if (table)
1198 retrieve_status(table, param, param_size);
1199 dm_put_live_table(md, srcu_idx);
1200
1201 out:
1202 dm_put(md);
1203
1204 return r;
1205 }
1206
1207 static inline fmode_t get_mode(struct dm_ioctl *param)
1208 {
1209 fmode_t mode = FMODE_READ | FMODE_WRITE;
1210
1211 if (param->flags & DM_READONLY_FLAG)
1212 mode = FMODE_READ;
1213
1214 return mode;
1215 }
1216
1217 static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
1218 struct dm_target_spec **spec, char **target_params)
1219 {
1220 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1221 *target_params = (char *) (*spec + 1);
1222
1223 if (*spec < (last + 1))
1224 return -EINVAL;
1225
1226 return invalid_str(*target_params, end);
1227 }
1228
1229 static int populate_table(struct dm_table *table,
1230 struct dm_ioctl *param, size_t param_size)
1231 {
1232 int r;
1233 unsigned int i = 0;
1234 struct dm_target_spec *spec = (struct dm_target_spec *) param;
1235 uint32_t next = param->data_start;
1236 void *end = (void *) param + param_size;
1237 char *target_params;
1238
1239 if (!param->target_count) {
1240 DMWARN("populate_table: no targets specified");
1241 return -EINVAL;
1242 }
1243
1244 for (i = 0; i < param->target_count; i++) {
1245
1246 r = next_target(spec, next, end, &spec, &target_params);
1247 if (r) {
1248 DMWARN("unable to find target");
1249 return r;
1250 }
1251
1252 r = dm_table_add_target(table, spec->target_type,
1253 (sector_t) spec->sector_start,
1254 (sector_t) spec->length,
1255 target_params);
1256 if (r) {
1257 DMWARN("error adding target to table");
1258 return r;
1259 }
1260
1261 next = spec->next;
1262 }
1263
1264 return dm_table_complete(table);
1265 }
1266
1267 static int table_load(struct dm_ioctl *param, size_t param_size)
1268 {
1269 int r;
1270 struct hash_cell *hc;
1271 struct dm_table *t, *old_map = NULL;
1272 struct mapped_device *md;
1273 struct target_type *immutable_target_type;
1274
1275 md = find_device(param);
1276 if (!md)
1277 return -ENXIO;
1278
1279 r = dm_table_create(&t, get_mode(param), param->target_count, md);
1280 if (r)
1281 goto err;
1282
1283 /* Protect md->type and md->queue against concurrent table loads. */
1284 dm_lock_md_type(md);
1285 r = populate_table(t, param, param_size);
1286 if (r)
1287 goto err_unlock_md_type;
1288
1289 immutable_target_type = dm_get_immutable_target_type(md);
1290 if (immutable_target_type &&
1291 (immutable_target_type != dm_table_get_immutable_target_type(t))) {
1292 DMWARN("can't replace immutable target type %s",
1293 immutable_target_type->name);
1294 r = -EINVAL;
1295 goto err_unlock_md_type;
1296 }
1297
1298 if (dm_get_md_type(md) == DM_TYPE_NONE)
1299 /* Initial table load: acquire type of table. */
1300 dm_set_md_type(md, dm_table_get_type(t));
1301 else if (dm_get_md_type(md) != dm_table_get_type(t)) {
1302 DMWARN("can't change device type after initial table load.");
1303 r = -EINVAL;
1304 goto err_unlock_md_type;
1305 }
1306
1307 /* setup md->queue to reflect md's type (may block) */
1308 r = dm_setup_md_queue(md);
1309 if (r) {
1310 DMWARN("unable to set up device queue for new table.");
1311 goto err_unlock_md_type;
1312 }
1313 dm_unlock_md_type(md);
1314
1315 /* stage inactive table */
1316 down_write(&_hash_lock);
1317 hc = dm_get_mdptr(md);
1318 if (!hc || hc->md != md) {
1319 DMWARN("device has been removed from the dev hash table.");
1320 up_write(&_hash_lock);
1321 r = -ENXIO;
1322 goto err_destroy_table;
1323 }
1324
1325 if (hc->new_map)
1326 old_map = hc->new_map;
1327 hc->new_map = t;
1328 up_write(&_hash_lock);
1329
1330 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1331 __dev_status(md, param);
1332
1333 if (old_map) {
1334 dm_sync_table(md);
1335 dm_table_destroy(old_map);
1336 }
1337
1338 dm_put(md);
1339
1340 return 0;
1341
1342 err_unlock_md_type:
1343 dm_unlock_md_type(md);
1344 err_destroy_table:
1345 dm_table_destroy(t);
1346 err:
1347 dm_put(md);
1348
1349 return r;
1350 }
1351
1352 static int table_clear(struct dm_ioctl *param, size_t param_size)
1353 {
1354 struct hash_cell *hc;
1355 struct mapped_device *md;
1356 struct dm_table *old_map = NULL;
1357
1358 down_write(&_hash_lock);
1359
1360 hc = __find_device_hash_cell(param);
1361 if (!hc) {
1362 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1363 up_write(&_hash_lock);
1364 return -ENXIO;
1365 }
1366
1367 if (hc->new_map) {
1368 old_map = hc->new_map;
1369 hc->new_map = NULL;
1370 }
1371
1372 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1373
1374 __dev_status(hc->md, param);
1375 md = hc->md;
1376 up_write(&_hash_lock);
1377 if (old_map) {
1378 dm_sync_table(md);
1379 dm_table_destroy(old_map);
1380 }
1381 dm_put(md);
1382
1383 return 0;
1384 }
1385
1386 /*
1387 * Retrieves a list of devices used by a particular dm device.
1388 */
1389 static void retrieve_deps(struct dm_table *table,
1390 struct dm_ioctl *param, size_t param_size)
1391 {
1392 unsigned int count = 0;
1393 struct list_head *tmp;
1394 size_t len, needed;
1395 struct dm_dev_internal *dd;
1396 struct dm_target_deps *deps;
1397
1398 deps = get_result_buffer(param, param_size, &len);
1399
1400 /*
1401 * Count the devices.
1402 */
1403 list_for_each (tmp, dm_table_get_devices(table))
1404 count++;
1405
1406 /*
1407 * Check we have enough space.
1408 */
1409 needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
1410 if (len < needed) {
1411 param->flags |= DM_BUFFER_FULL_FLAG;
1412 return;
1413 }
1414
1415 /*
1416 * Fill in the devices.
1417 */
1418 deps->count = count;
1419 count = 0;
1420 list_for_each_entry (dd, dm_table_get_devices(table), list)
1421 deps->dev[count++] = huge_encode_dev(dd->dm_dev.bdev->bd_dev);
1422
1423 param->data_size = param->data_start + needed;
1424 }
1425
1426 static int table_deps(struct dm_ioctl *param, size_t param_size)
1427 {
1428 struct mapped_device *md;
1429 struct dm_table *table;
1430 int srcu_idx;
1431
1432 md = find_device(param);
1433 if (!md)
1434 return -ENXIO;
1435
1436 __dev_status(md, param);
1437
1438 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1439 if (table)
1440 retrieve_deps(table, param, param_size);
1441 dm_put_live_table(md, srcu_idx);
1442
1443 dm_put(md);
1444
1445 return 0;
1446 }
1447
1448 /*
1449 * Return the status of a device as a text string for each
1450 * target.
1451 */
1452 static int table_status(struct dm_ioctl *param, size_t param_size)
1453 {
1454 struct mapped_device *md;
1455 struct dm_table *table;
1456 int srcu_idx;
1457
1458 md = find_device(param);
1459 if (!md)
1460 return -ENXIO;
1461
1462 __dev_status(md, param);
1463
1464 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1465 if (table)
1466 retrieve_status(table, param, param_size);
1467 dm_put_live_table(md, srcu_idx);
1468
1469 dm_put(md);
1470
1471 return 0;
1472 }
1473
1474 /*
1475 * Process device-mapper dependent messages. Messages prefixed with '@'
1476 * are processed by the DM core. All others are delivered to the target.
1477 * Returns a number <= 1 if message was processed by device mapper.
1478 * Returns 2 if message should be delivered to the target.
1479 */
1480 static int message_for_md(struct mapped_device *md, unsigned argc, char **argv,
1481 char *result, unsigned maxlen)
1482 {
1483 int r;
1484
1485 if (**argv != '@')
1486 return 2; /* no '@' prefix, deliver to target */
1487
1488 if (!strcasecmp(argv[0], "@cancel_deferred_remove")) {
1489 if (argc != 1) {
1490 DMERR("Invalid arguments for @cancel_deferred_remove");
1491 return -EINVAL;
1492 }
1493 return dm_cancel_deferred_remove(md);
1494 }
1495
1496 r = dm_stats_message(md, argc, argv, result, maxlen);
1497 if (r < 2)
1498 return r;
1499
1500 DMERR("Unsupported message sent to DM core: %s", argv[0]);
1501 return -EINVAL;
1502 }
1503
1504 /*
1505 * Pass a message to the target that's at the supplied device offset.
1506 */
1507 static int target_message(struct dm_ioctl *param, size_t param_size)
1508 {
1509 int r, argc;
1510 char **argv;
1511 struct mapped_device *md;
1512 struct dm_table *table;
1513 struct dm_target *ti;
1514 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1515 size_t maxlen;
1516 char *result = get_result_buffer(param, param_size, &maxlen);
1517 int srcu_idx;
1518
1519 md = find_device(param);
1520 if (!md)
1521 return -ENXIO;
1522
1523 if (tmsg < (struct dm_target_msg *) param->data ||
1524 invalid_str(tmsg->message, (void *) param + param_size)) {
1525 DMWARN("Invalid target message parameters.");
1526 r = -EINVAL;
1527 goto out;
1528 }
1529
1530 r = dm_split_args(&argc, &argv, tmsg->message);
1531 if (r) {
1532 DMWARN("Failed to split target message parameters");
1533 goto out;
1534 }
1535
1536 if (!argc) {
1537 DMWARN("Empty message received.");
1538 goto out_argv;
1539 }
1540
1541 r = message_for_md(md, argc, argv, result, maxlen);
1542 if (r <= 1)
1543 goto out_argv;
1544
1545 table = dm_get_live_table(md, &srcu_idx);
1546 if (!table)
1547 goto out_table;
1548
1549 if (dm_deleting_md(md)) {
1550 r = -ENXIO;
1551 goto out_table;
1552 }
1553
1554 ti = dm_table_find_target(table, tmsg->sector);
1555 if (!dm_target_is_valid(ti)) {
1556 DMWARN("Target message sector outside device.");
1557 r = -EINVAL;
1558 } else if (ti->type->message)
1559 r = ti->type->message(ti, argc, argv);
1560 else {
1561 DMWARN("Target type does not support messages");
1562 r = -EINVAL;
1563 }
1564
1565 out_table:
1566 dm_put_live_table(md, srcu_idx);
1567 out_argv:
1568 kfree(argv);
1569 out:
1570 if (r >= 0)
1571 __dev_status(md, param);
1572
1573 if (r == 1) {
1574 param->flags |= DM_DATA_OUT_FLAG;
1575 if (dm_message_test_buffer_overflow(result, maxlen))
1576 param->flags |= DM_BUFFER_FULL_FLAG;
1577 else
1578 param->data_size = param->data_start + strlen(result) + 1;
1579 r = 0;
1580 }
1581
1582 dm_put(md);
1583 return r;
1584 }
1585
1586 /*
1587 * The ioctl parameter block consists of two parts, a dm_ioctl struct
1588 * followed by a data buffer. This flag is set if the second part,
1589 * which has a variable size, is not used by the function processing
1590 * the ioctl.
1591 */
1592 #define IOCTL_FLAGS_NO_PARAMS 1
1593
1594 /*-----------------------------------------------------------------
1595 * Implementation of open/close/ioctl on the special char
1596 * device.
1597 *---------------------------------------------------------------*/
1598 static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags)
1599 {
1600 static struct {
1601 int cmd;
1602 int flags;
1603 ioctl_fn fn;
1604 } _ioctls[] = {
1605 {DM_VERSION_CMD, 0, NULL}, /* version is dealt with elsewhere */
1606 {DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS, remove_all},
1607 {DM_LIST_DEVICES_CMD, 0, list_devices},
1608
1609 {DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS, dev_create},
1610 {DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS, dev_remove},
1611 {DM_DEV_RENAME_CMD, 0, dev_rename},
1612 {DM_DEV_SUSPEND_CMD, IOCTL_FLAGS_NO_PARAMS, dev_suspend},
1613 {DM_DEV_STATUS_CMD, IOCTL_FLAGS_NO_PARAMS, dev_status},
1614 {DM_DEV_WAIT_CMD, 0, dev_wait},
1615
1616 {DM_TABLE_LOAD_CMD, 0, table_load},
1617 {DM_TABLE_CLEAR_CMD, IOCTL_FLAGS_NO_PARAMS, table_clear},
1618 {DM_TABLE_DEPS_CMD, 0, table_deps},
1619 {DM_TABLE_STATUS_CMD, 0, table_status},
1620
1621 {DM_LIST_VERSIONS_CMD, 0, list_versions},
1622
1623 {DM_TARGET_MSG_CMD, 0, target_message},
1624 {DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry}
1625 };
1626
1627 if (unlikely(cmd >= ARRAY_SIZE(_ioctls)))
1628 return NULL;
1629
1630 *ioctl_flags = _ioctls[cmd].flags;
1631 return _ioctls[cmd].fn;
1632 }
1633
1634 /*
1635 * As well as checking the version compatibility this always
1636 * copies the kernel interface version out.
1637 */
1638 static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1639 {
1640 uint32_t version[3];
1641 int r = 0;
1642
1643 if (copy_from_user(version, user->version, sizeof(version)))
1644 return -EFAULT;
1645
1646 if ((DM_VERSION_MAJOR != version[0]) ||
1647 (DM_VERSION_MINOR < version[1])) {
1648 DMWARN("ioctl interface mismatch: "
1649 "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1650 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1651 DM_VERSION_PATCHLEVEL,
1652 version[0], version[1], version[2], cmd);
1653 r = -EINVAL;
1654 }
1655
1656 /*
1657 * Fill in the kernel version.
1658 */
1659 version[0] = DM_VERSION_MAJOR;
1660 version[1] = DM_VERSION_MINOR;
1661 version[2] = DM_VERSION_PATCHLEVEL;
1662 if (copy_to_user(user->version, version, sizeof(version)))
1663 return -EFAULT;
1664
1665 return r;
1666 }
1667
1668 #define DM_PARAMS_KMALLOC 0x0001 /* Params alloced with kmalloc */
1669 #define DM_PARAMS_VMALLOC 0x0002 /* Params alloced with vmalloc */
1670 #define DM_WIPE_BUFFER 0x0010 /* Wipe input buffer before returning from ioctl */
1671
1672 static void free_params(struct dm_ioctl *param, size_t param_size, int param_flags)
1673 {
1674 if (param_flags & DM_WIPE_BUFFER)
1675 memset(param, 0, param_size);
1676
1677 if (param_flags & DM_PARAMS_KMALLOC)
1678 kfree(param);
1679 if (param_flags & DM_PARAMS_VMALLOC)
1680 vfree(param);
1681 }
1682
1683 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel,
1684 int ioctl_flags,
1685 struct dm_ioctl **param, int *param_flags)
1686 {
1687 struct dm_ioctl *dmi;
1688 int secure_data;
1689 const size_t minimum_data_size = sizeof(*param_kernel) - sizeof(param_kernel->data);
1690
1691 if (copy_from_user(param_kernel, user, minimum_data_size))
1692 return -EFAULT;
1693
1694 if (param_kernel->data_size < minimum_data_size)
1695 return -EINVAL;
1696
1697 secure_data = param_kernel->flags & DM_SECURE_DATA_FLAG;
1698
1699 *param_flags = secure_data ? DM_WIPE_BUFFER : 0;
1700
1701 if (ioctl_flags & IOCTL_FLAGS_NO_PARAMS) {
1702 dmi = param_kernel;
1703 dmi->data_size = minimum_data_size;
1704 goto data_copied;
1705 }
1706
1707 /*
1708 * Try to avoid low memory issues when a device is suspended.
1709 * Use kmalloc() rather than vmalloc() when we can.
1710 */
1711 dmi = NULL;
1712 if (param_kernel->data_size <= KMALLOC_MAX_SIZE) {
1713 dmi = kmalloc(param_kernel->data_size, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN);
1714 if (dmi)
1715 *param_flags |= DM_PARAMS_KMALLOC;
1716 }
1717
1718 if (!dmi) {
1719 unsigned noio_flag;
1720 noio_flag = memalloc_noio_save();
1721 dmi = __vmalloc(param_kernel->data_size, GFP_NOIO | __GFP_REPEAT | __GFP_HIGH | __GFP_HIGHMEM, PAGE_KERNEL);
1722 memalloc_noio_restore(noio_flag);
1723 if (dmi)
1724 *param_flags |= DM_PARAMS_VMALLOC;
1725 }
1726
1727 if (!dmi) {
1728 if (secure_data && clear_user(user, param_kernel->data_size))
1729 return -EFAULT;
1730 return -ENOMEM;
1731 }
1732
1733 if (copy_from_user(dmi, user, param_kernel->data_size))
1734 goto bad;
1735
1736 data_copied:
1737 /*
1738 * Abort if something changed the ioctl data while it was being copied.
1739 */
1740 if (dmi->data_size != param_kernel->data_size) {
1741 DMERR("rejecting ioctl: data size modified while processing parameters");
1742 goto bad;
1743 }
1744
1745 /* Wipe the user buffer so we do not return it to userspace */
1746 if (secure_data && clear_user(user, param_kernel->data_size))
1747 goto bad;
1748
1749 *param = dmi;
1750 return 0;
1751
1752 bad:
1753 free_params(dmi, param_kernel->data_size, *param_flags);
1754
1755 return -EFAULT;
1756 }
1757
1758 static int validate_params(uint cmd, struct dm_ioctl *param)
1759 {
1760 /* Always clear this flag */
1761 param->flags &= ~DM_BUFFER_FULL_FLAG;
1762 param->flags &= ~DM_UEVENT_GENERATED_FLAG;
1763 param->flags &= ~DM_SECURE_DATA_FLAG;
1764 param->flags &= ~DM_DATA_OUT_FLAG;
1765
1766 /* Ignores parameters */
1767 if (cmd == DM_REMOVE_ALL_CMD ||
1768 cmd == DM_LIST_DEVICES_CMD ||
1769 cmd == DM_LIST_VERSIONS_CMD)
1770 return 0;
1771
1772 if ((cmd == DM_DEV_CREATE_CMD)) {
1773 if (!*param->name) {
1774 DMWARN("name not supplied when creating device");
1775 return -EINVAL;
1776 }
1777 } else if ((*param->uuid && *param->name)) {
1778 DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
1779 return -EINVAL;
1780 }
1781
1782 /* Ensure strings are terminated */
1783 param->name[DM_NAME_LEN - 1] = '\0';
1784 param->uuid[DM_UUID_LEN - 1] = '\0';
1785
1786 return 0;
1787 }
1788
1789 static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
1790 {
1791 int r = 0;
1792 int ioctl_flags;
1793 int param_flags;
1794 unsigned int cmd;
1795 struct dm_ioctl *uninitialized_var(param);
1796 ioctl_fn fn = NULL;
1797 size_t input_param_size;
1798 struct dm_ioctl param_kernel;
1799
1800 /* only root can play with this */
1801 if (!capable(CAP_SYS_ADMIN))
1802 return -EACCES;
1803
1804 if (_IOC_TYPE(command) != DM_IOCTL)
1805 return -ENOTTY;
1806
1807 cmd = _IOC_NR(command);
1808
1809 /*
1810 * Check the interface version passed in. This also
1811 * writes out the kernel's interface version.
1812 */
1813 r = check_version(cmd, user);
1814 if (r)
1815 return r;
1816
1817 /*
1818 * Nothing more to do for the version command.
1819 */
1820 if (cmd == DM_VERSION_CMD)
1821 return 0;
1822
1823 fn = lookup_ioctl(cmd, &ioctl_flags);
1824 if (!fn) {
1825 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1826 return -ENOTTY;
1827 }
1828
1829 /*
1830 * Copy the parameters into kernel space.
1831 */
1832 r = copy_params(user, &param_kernel, ioctl_flags, &param, &param_flags);
1833
1834 if (r)
1835 return r;
1836
1837 input_param_size = param->data_size;
1838 r = validate_params(cmd, param);
1839 if (r)
1840 goto out;
1841
1842 param->data_size = sizeof(*param);
1843 r = fn(param, input_param_size);
1844
1845 if (unlikely(param->flags & DM_BUFFER_FULL_FLAG) &&
1846 unlikely(ioctl_flags & IOCTL_FLAGS_NO_PARAMS))
1847 DMERR("ioctl %d tried to output some data but has IOCTL_FLAGS_NO_PARAMS set", cmd);
1848
1849 /*
1850 * Copy the results back to userland.
1851 */
1852 if (!r && copy_to_user(user, param, param->data_size))
1853 r = -EFAULT;
1854
1855 out:
1856 free_params(param, input_param_size, param_flags);
1857 return r;
1858 }
1859
1860 static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
1861 {
1862 return (long)ctl_ioctl(command, (struct dm_ioctl __user *)u);
1863 }
1864
1865 #ifdef CONFIG_COMPAT
1866 static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
1867 {
1868 return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
1869 }
1870 #else
1871 #define dm_compat_ctl_ioctl NULL
1872 #endif
1873
1874 static const struct file_operations _ctl_fops = {
1875 .open = nonseekable_open,
1876 .unlocked_ioctl = dm_ctl_ioctl,
1877 .compat_ioctl = dm_compat_ctl_ioctl,
1878 .owner = THIS_MODULE,
1879 .llseek = noop_llseek,
1880 };
1881
1882 static struct miscdevice _dm_misc = {
1883 .minor = MAPPER_CTRL_MINOR,
1884 .name = DM_NAME,
1885 .nodename = DM_DIR "/" DM_CONTROL_NODE,
1886 .fops = &_ctl_fops
1887 };
1888
1889 MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
1890 MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
1891
1892 /*
1893 * Create misc character device and link to DM_DIR/control.
1894 */
1895 int __init dm_interface_init(void)
1896 {
1897 int r;
1898
1899 r = dm_hash_init();
1900 if (r)
1901 return r;
1902
1903 r = misc_register(&_dm_misc);
1904 if (r) {
1905 DMERR("misc_register failed for control device");
1906 dm_hash_exit();
1907 return r;
1908 }
1909
1910 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
1911 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
1912 DM_DRIVER_EMAIL);
1913 return 0;
1914 }
1915
1916 void dm_interface_exit(void)
1917 {
1918 if (misc_deregister(&_dm_misc) < 0)
1919 DMERR("misc_deregister failed for control device");
1920
1921 dm_hash_exit();
1922 }
1923
1924 /**
1925 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
1926 * @md: Pointer to mapped_device
1927 * @name: Buffer (size DM_NAME_LEN) for name
1928 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
1929 */
1930 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
1931 {
1932 int r = 0;
1933 struct hash_cell *hc;
1934
1935 if (!md)
1936 return -ENXIO;
1937
1938 mutex_lock(&dm_hash_cells_mutex);
1939 hc = dm_get_mdptr(md);
1940 if (!hc || hc->md != md) {
1941 r = -ENXIO;
1942 goto out;
1943 }
1944
1945 if (name)
1946 strcpy(name, hc->name);
1947 if (uuid)
1948 strcpy(uuid, hc->uuid ? : "");
1949
1950 out:
1951 mutex_unlock(&dm_hash_cells_mutex);
1952
1953 return r;
1954 }
Linux with added FPC-III support