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watchdog: pic32-dmt: Remove .owner field for driver
[linux/fpc-iii.git] / drivers / md / dm-ioctl.c
blob2c7ca258c4e47ac3ab005752983925413c56cd61
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_put_live_table, because dm_table_destroy
643 * waits for this dm_put_live_table 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 | DM_INTERNAL_SUSPEND_FLAG);
688
689 if (dm_suspended_md(md))
690 param->flags |= DM_SUSPEND_FLAG;
691
692 if (dm_suspended_internally_md(md))
693 param->flags |= DM_INTERNAL_SUSPEND_FLAG;
694
695 if (dm_test_deferred_remove_flag(md))
696 param->flags |= DM_DEFERRED_REMOVE;
697
698 param->dev = huge_encode_dev(disk_devt(disk));
699
700 /*
701 * Yes, this will be out of date by the time it gets back
702 * to userland, but it is still very useful for
703 * debugging.
704 */
705 param->open_count = dm_open_count(md);
706
707 param->event_nr = dm_get_event_nr(md);
708 param->target_count = 0;
709
710 table = dm_get_live_table(md, &srcu_idx);
711 if (table) {
712 if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
713 if (get_disk_ro(disk))
714 param->flags |= DM_READONLY_FLAG;
715 param->target_count = dm_table_get_num_targets(table);
716 }
717
718 param->flags |= DM_ACTIVE_PRESENT_FLAG;
719 }
720 dm_put_live_table(md, srcu_idx);
721
722 if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
723 int srcu_idx;
724 table = dm_get_inactive_table(md, &srcu_idx);
725 if (table) {
726 if (!(dm_table_get_mode(table) & FMODE_WRITE))
727 param->flags |= DM_READONLY_FLAG;
728 param->target_count = dm_table_get_num_targets(table);
729 }
730 dm_put_live_table(md, srcu_idx);
731 }
732 }
733
734 static int dev_create(struct dm_ioctl *param, size_t param_size)
735 {
736 int r, m = DM_ANY_MINOR;
737 struct mapped_device *md;
738
739 r = check_name(param->name);
740 if (r)
741 return r;
742
743 if (param->flags & DM_PERSISTENT_DEV_FLAG)
744 m = MINOR(huge_decode_dev(param->dev));
745
746 r = dm_create(m, &md);
747 if (r)
748 return r;
749
750 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
751 if (r) {
752 dm_put(md);
753 dm_destroy(md);
754 return r;
755 }
756
757 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
758
759 __dev_status(md, param);
760
761 dm_put(md);
762
763 return 0;
764 }
765
766 /*
767 * Always use UUID for lookups if it's present, otherwise use name or dev.
768 */
769 static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
770 {
771 struct hash_cell *hc = NULL;
772
773 if (*param->uuid) {
774 if (*param->name || param->dev)
775 return NULL;
776
777 hc = __get_uuid_cell(param->uuid);
778 if (!hc)
779 return NULL;
780 } else if (*param->name) {
781 if (param->dev)
782 return NULL;
783
784 hc = __get_name_cell(param->name);
785 if (!hc)
786 return NULL;
787 } else if (param->dev) {
788 hc = __get_dev_cell(param->dev);
789 if (!hc)
790 return NULL;
791 } else
792 return NULL;
793
794 /*
795 * Sneakily write in both the name and the uuid
796 * while we have the cell.
797 */
798 strlcpy(param->name, hc->name, sizeof(param->name));
799 if (hc->uuid)
800 strlcpy(param->uuid, hc->uuid, sizeof(param->uuid));
801 else
802 param->uuid[0] = '\0';
803
804 if (hc->new_map)
805 param->flags |= DM_INACTIVE_PRESENT_FLAG;
806 else
807 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
808
809 return hc;
810 }
811
812 static struct mapped_device *find_device(struct dm_ioctl *param)
813 {
814 struct hash_cell *hc;
815 struct mapped_device *md = NULL;
816
817 down_read(&_hash_lock);
818 hc = __find_device_hash_cell(param);
819 if (hc)
820 md = hc->md;
821 up_read(&_hash_lock);
822
823 return md;
824 }
825
826 static int dev_remove(struct dm_ioctl *param, size_t param_size)
827 {
828 struct hash_cell *hc;
829 struct mapped_device *md;
830 int r;
831 struct dm_table *t;
832
833 down_write(&_hash_lock);
834 hc = __find_device_hash_cell(param);
835
836 if (!hc) {
837 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
838 up_write(&_hash_lock);
839 return -ENXIO;
840 }
841
842 md = hc->md;
843
844 /*
845 * Ensure the device is not open and nothing further can open it.
846 */
847 r = dm_lock_for_deletion(md, !!(param->flags & DM_DEFERRED_REMOVE), false);
848 if (r) {
849 if (r == -EBUSY && param->flags & DM_DEFERRED_REMOVE) {
850 up_write(&_hash_lock);
851 dm_put(md);
852 return 0;
853 }
854 DMDEBUG_LIMIT("unable to remove open device %s", hc->name);
855 up_write(&_hash_lock);
856 dm_put(md);
857 return r;
858 }
859
860 t = __hash_remove(hc);
861 up_write(&_hash_lock);
862
863 if (t) {
864 dm_sync_table(md);
865 dm_table_destroy(t);
866 }
867
868 param->flags &= ~DM_DEFERRED_REMOVE;
869
870 if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr))
871 param->flags |= DM_UEVENT_GENERATED_FLAG;
872
873 dm_put(md);
874 dm_destroy(md);
875 return 0;
876 }
877
878 /*
879 * Check a string doesn't overrun the chunk of
880 * memory we copied from userland.
881 */
882 static int invalid_str(char *str, void *end)
883 {
884 while ((void *) str < end)
885 if (!*str++)
886 return 0;
887
888 return -EINVAL;
889 }
890
891 static int dev_rename(struct dm_ioctl *param, size_t param_size)
892 {
893 int r;
894 char *new_data = (char *) param + param->data_start;
895 struct mapped_device *md;
896 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
897
898 if (new_data < param->data ||
899 invalid_str(new_data, (void *) param + param_size) || !*new_data ||
900 strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
901 DMWARN("Invalid new mapped device name or uuid string supplied.");
902 return -EINVAL;
903 }
904
905 if (!change_uuid) {
906 r = check_name(new_data);
907 if (r)
908 return r;
909 }
910
911 md = dm_hash_rename(param, new_data);
912 if (IS_ERR(md))
913 return PTR_ERR(md);
914
915 __dev_status(md, param);
916 dm_put(md);
917
918 return 0;
919 }
920
921 static int dev_set_geometry(struct dm_ioctl *param, size_t param_size)
922 {
923 int r = -EINVAL, x;
924 struct mapped_device *md;
925 struct hd_geometry geometry;
926 unsigned long indata[4];
927 char *geostr = (char *) param + param->data_start;
928 char dummy;
929
930 md = find_device(param);
931 if (!md)
932 return -ENXIO;
933
934 if (geostr < param->data ||
935 invalid_str(geostr, (void *) param + param_size)) {
936 DMWARN("Invalid geometry supplied.");
937 goto out;
938 }
939
940 x = sscanf(geostr, "%lu %lu %lu %lu%c", indata,
941 indata + 1, indata + 2, indata + 3, &dummy);
942
943 if (x != 4) {
944 DMWARN("Unable to interpret geometry settings.");
945 goto out;
946 }
947
948 if (indata[0] > 65535 || indata[1] > 255 ||
949 indata[2] > 255 || indata[3] > ULONG_MAX) {
950 DMWARN("Geometry exceeds range limits.");
951 goto out;
952 }
953
954 geometry.cylinders = indata[0];
955 geometry.heads = indata[1];
956 geometry.sectors = indata[2];
957 geometry.start = indata[3];
958
959 r = dm_set_geometry(md, &geometry);
960
961 param->data_size = 0;
962
963 out:
964 dm_put(md);
965 return r;
966 }
967
968 static int do_suspend(struct dm_ioctl *param)
969 {
970 int r = 0;
971 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
972 struct mapped_device *md;
973
974 md = find_device(param);
975 if (!md)
976 return -ENXIO;
977
978 if (param->flags & DM_SKIP_LOCKFS_FLAG)
979 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
980 if (param->flags & DM_NOFLUSH_FLAG)
981 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
982
983 if (!dm_suspended_md(md)) {
984 r = dm_suspend(md, suspend_flags);
985 if (r)
986 goto out;
987 }
988
989 __dev_status(md, param);
990
991 out:
992 dm_put(md);
993
994 return r;
995 }
996
997 static int do_resume(struct dm_ioctl *param)
998 {
999 int r = 0;
1000 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
1001 struct hash_cell *hc;
1002 struct mapped_device *md;
1003 struct dm_table *new_map, *old_map = NULL;
1004
1005 down_write(&_hash_lock);
1006
1007 hc = __find_device_hash_cell(param);
1008 if (!hc) {
1009 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1010 up_write(&_hash_lock);
1011 return -ENXIO;
1012 }
1013
1014 md = hc->md;
1015
1016 new_map = hc->new_map;
1017 hc->new_map = NULL;
1018 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1019
1020 up_write(&_hash_lock);
1021
1022 /* Do we need to load a new map ? */
1023 if (new_map) {
1024 /* Suspend if it isn't already suspended */
1025 if (param->flags & DM_SKIP_LOCKFS_FLAG)
1026 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
1027 if (param->flags & DM_NOFLUSH_FLAG)
1028 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
1029 if (!dm_suspended_md(md))
1030 dm_suspend(md, suspend_flags);
1031
1032 old_map = dm_swap_table(md, new_map);
1033 if (IS_ERR(old_map)) {
1034 dm_sync_table(md);
1035 dm_table_destroy(new_map);
1036 dm_put(md);
1037 return PTR_ERR(old_map);
1038 }
1039
1040 if (dm_table_get_mode(new_map) & FMODE_WRITE)
1041 set_disk_ro(dm_disk(md), 0);
1042 else
1043 set_disk_ro(dm_disk(md), 1);
1044 }
1045
1046 if (dm_suspended_md(md)) {
1047 r = dm_resume(md);
1048 if (!r && !dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr))
1049 param->flags |= DM_UEVENT_GENERATED_FLAG;
1050 }
1051
1052 /*
1053 * Since dm_swap_table synchronizes RCU, nobody should be in
1054 * read-side critical section already.
1055 */
1056 if (old_map)
1057 dm_table_destroy(old_map);
1058
1059 if (!r)
1060 __dev_status(md, param);
1061
1062 dm_put(md);
1063 return r;
1064 }
1065
1066 /*
1067 * Set or unset the suspension state of a device.
1068 * If the device already is in the requested state we just return its status.
1069 */
1070 static int dev_suspend(struct dm_ioctl *param, size_t param_size)
1071 {
1072 if (param->flags & DM_SUSPEND_FLAG)
1073 return do_suspend(param);
1074
1075 return do_resume(param);
1076 }
1077
1078 /*
1079 * Copies device info back to user space, used by
1080 * the create and info ioctls.
1081 */
1082 static int dev_status(struct dm_ioctl *param, size_t param_size)
1083 {
1084 struct mapped_device *md;
1085
1086 md = find_device(param);
1087 if (!md)
1088 return -ENXIO;
1089
1090 __dev_status(md, param);
1091 dm_put(md);
1092
1093 return 0;
1094 }
1095
1096 /*
1097 * Build up the status struct for each target
1098 */
1099 static void retrieve_status(struct dm_table *table,
1100 struct dm_ioctl *param, size_t param_size)
1101 {
1102 unsigned int i, num_targets;
1103 struct dm_target_spec *spec;
1104 char *outbuf, *outptr;
1105 status_type_t type;
1106 size_t remaining, len, used = 0;
1107 unsigned status_flags = 0;
1108
1109 outptr = outbuf = get_result_buffer(param, param_size, &len);
1110
1111 if (param->flags & DM_STATUS_TABLE_FLAG)
1112 type = STATUSTYPE_TABLE;
1113 else
1114 type = STATUSTYPE_INFO;
1115
1116 /* Get all the target info */
1117 num_targets = dm_table_get_num_targets(table);
1118 for (i = 0; i < num_targets; i++) {
1119 struct dm_target *ti = dm_table_get_target(table, i);
1120 size_t l;
1121
1122 remaining = len - (outptr - outbuf);
1123 if (remaining <= sizeof(struct dm_target_spec)) {
1124 param->flags |= DM_BUFFER_FULL_FLAG;
1125 break;
1126 }
1127
1128 spec = (struct dm_target_spec *) outptr;
1129
1130 spec->status = 0;
1131 spec->sector_start = ti->begin;
1132 spec->length = ti->len;
1133 strncpy(spec->target_type, ti->type->name,
1134 sizeof(spec->target_type));
1135
1136 outptr += sizeof(struct dm_target_spec);
1137 remaining = len - (outptr - outbuf);
1138 if (remaining <= 0) {
1139 param->flags |= DM_BUFFER_FULL_FLAG;
1140 break;
1141 }
1142
1143 /* Get the status/table string from the target driver */
1144 if (ti->type->status) {
1145 if (param->flags & DM_NOFLUSH_FLAG)
1146 status_flags |= DM_STATUS_NOFLUSH_FLAG;
1147 ti->type->status(ti, type, status_flags, outptr, remaining);
1148 } else
1149 outptr[0] = '\0';
1150
1151 l = strlen(outptr) + 1;
1152 if (l == remaining) {
1153 param->flags |= DM_BUFFER_FULL_FLAG;
1154 break;
1155 }
1156
1157 outptr += l;
1158 used = param->data_start + (outptr - outbuf);
1159
1160 outptr = align_ptr(outptr);
1161 spec->next = outptr - outbuf;
1162 }
1163
1164 if (used)
1165 param->data_size = used;
1166
1167 param->target_count = num_targets;
1168 }
1169
1170 /*
1171 * Wait for a device to report an event
1172 */
1173 static int dev_wait(struct dm_ioctl *param, size_t param_size)
1174 {
1175 int r = 0;
1176 struct mapped_device *md;
1177 struct dm_table *table;
1178 int srcu_idx;
1179
1180 md = find_device(param);
1181 if (!md)
1182 return -ENXIO;
1183
1184 /*
1185 * Wait for a notification event
1186 */
1187 if (dm_wait_event(md, param->event_nr)) {
1188 r = -ERESTARTSYS;
1189 goto out;
1190 }
1191
1192 /*
1193 * The userland program is going to want to know what
1194 * changed to trigger the event, so we may as well tell
1195 * him and save an ioctl.
1196 */
1197 __dev_status(md, param);
1198
1199 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1200 if (table)
1201 retrieve_status(table, param, param_size);
1202 dm_put_live_table(md, srcu_idx);
1203
1204 out:
1205 dm_put(md);
1206
1207 return r;
1208 }
1209
1210 static inline fmode_t get_mode(struct dm_ioctl *param)
1211 {
1212 fmode_t mode = FMODE_READ | FMODE_WRITE;
1213
1214 if (param->flags & DM_READONLY_FLAG)
1215 mode = FMODE_READ;
1216
1217 return mode;
1218 }
1219
1220 static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
1221 struct dm_target_spec **spec, char **target_params)
1222 {
1223 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1224 *target_params = (char *) (*spec + 1);
1225
1226 if (*spec < (last + 1))
1227 return -EINVAL;
1228
1229 return invalid_str(*target_params, end);
1230 }
1231
1232 static int populate_table(struct dm_table *table,
1233 struct dm_ioctl *param, size_t param_size)
1234 {
1235 int r;
1236 unsigned int i = 0;
1237 struct dm_target_spec *spec = (struct dm_target_spec *) param;
1238 uint32_t next = param->data_start;
1239 void *end = (void *) param + param_size;
1240 char *target_params;
1241
1242 if (!param->target_count) {
1243 DMWARN("populate_table: no targets specified");
1244 return -EINVAL;
1245 }
1246
1247 for (i = 0; i < param->target_count; i++) {
1248
1249 r = next_target(spec, next, end, &spec, &target_params);
1250 if (r) {
1251 DMWARN("unable to find target");
1252 return r;
1253 }
1254
1255 r = dm_table_add_target(table, spec->target_type,
1256 (sector_t) spec->sector_start,
1257 (sector_t) spec->length,
1258 target_params);
1259 if (r) {
1260 DMWARN("error adding target to table");
1261 return r;
1262 }
1263
1264 next = spec->next;
1265 }
1266
1267 return dm_table_complete(table);
1268 }
1269
1270 static int table_load(struct dm_ioctl *param, size_t param_size)
1271 {
1272 int r;
1273 struct hash_cell *hc;
1274 struct dm_table *t, *old_map = NULL;
1275 struct mapped_device *md;
1276 struct target_type *immutable_target_type;
1277
1278 md = find_device(param);
1279 if (!md)
1280 return -ENXIO;
1281
1282 r = dm_table_create(&t, get_mode(param), param->target_count, md);
1283 if (r)
1284 goto err;
1285
1286 /* Protect md->type and md->queue against concurrent table loads. */
1287 dm_lock_md_type(md);
1288 r = populate_table(t, param, param_size);
1289 if (r)
1290 goto err_unlock_md_type;
1291
1292 immutable_target_type = dm_get_immutable_target_type(md);
1293 if (immutable_target_type &&
1294 (immutable_target_type != dm_table_get_immutable_target_type(t)) &&
1295 !dm_table_get_wildcard_target(t)) {
1296 DMWARN("can't replace immutable target type %s",
1297 immutable_target_type->name);
1298 r = -EINVAL;
1299 goto err_unlock_md_type;
1300 }
1301
1302 if (dm_get_md_type(md) == DM_TYPE_NONE) {
1303 /* Initial table load: acquire type of table. */
1304 dm_set_md_type(md, dm_table_get_type(t));
1305
1306 /* setup md->queue to reflect md's type (may block) */
1307 r = dm_setup_md_queue(md, t);
1308 if (r) {
1309 DMWARN("unable to set up device queue for new table.");
1310 goto err_unlock_md_type;
1311 }
1312 } else if (dm_get_md_type(md) != dm_table_get_type(t)) {
1313 DMWARN("can't change device type after initial table load.");
1314 r = -EINVAL;
1315 goto err_unlock_md_type;
1316 }
1317
1318 dm_unlock_md_type(md);
1319
1320 /* stage inactive table */
1321 down_write(&_hash_lock);
1322 hc = dm_get_mdptr(md);
1323 if (!hc || hc->md != md) {
1324 DMWARN("device has been removed from the dev hash table.");
1325 up_write(&_hash_lock);
1326 r = -ENXIO;
1327 goto err_destroy_table;
1328 }
1329
1330 if (hc->new_map)
1331 old_map = hc->new_map;
1332 hc->new_map = t;
1333 up_write(&_hash_lock);
1334
1335 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1336 __dev_status(md, param);
1337
1338 if (old_map) {
1339 dm_sync_table(md);
1340 dm_table_destroy(old_map);
1341 }
1342
1343 dm_put(md);
1344
1345 return 0;
1346
1347 err_unlock_md_type:
1348 dm_unlock_md_type(md);
1349 err_destroy_table:
1350 dm_table_destroy(t);
1351 err:
1352 dm_put(md);
1353
1354 return r;
1355 }
1356
1357 static int table_clear(struct dm_ioctl *param, size_t param_size)
1358 {
1359 struct hash_cell *hc;
1360 struct mapped_device *md;
1361 struct dm_table *old_map = NULL;
1362
1363 down_write(&_hash_lock);
1364
1365 hc = __find_device_hash_cell(param);
1366 if (!hc) {
1367 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1368 up_write(&_hash_lock);
1369 return -ENXIO;
1370 }
1371
1372 if (hc->new_map) {
1373 old_map = hc->new_map;
1374 hc->new_map = NULL;
1375 }
1376
1377 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1378
1379 __dev_status(hc->md, param);
1380 md = hc->md;
1381 up_write(&_hash_lock);
1382 if (old_map) {
1383 dm_sync_table(md);
1384 dm_table_destroy(old_map);
1385 }
1386 dm_put(md);
1387
1388 return 0;
1389 }
1390
1391 /*
1392 * Retrieves a list of devices used by a particular dm device.
1393 */
1394 static void retrieve_deps(struct dm_table *table,
1395 struct dm_ioctl *param, size_t param_size)
1396 {
1397 unsigned int count = 0;
1398 struct list_head *tmp;
1399 size_t len, needed;
1400 struct dm_dev_internal *dd;
1401 struct dm_target_deps *deps;
1402
1403 deps = get_result_buffer(param, param_size, &len);
1404
1405 /*
1406 * Count the devices.
1407 */
1408 list_for_each (tmp, dm_table_get_devices(table))
1409 count++;
1410
1411 /*
1412 * Check we have enough space.
1413 */
1414 needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
1415 if (len < needed) {
1416 param->flags |= DM_BUFFER_FULL_FLAG;
1417 return;
1418 }
1419
1420 /*
1421 * Fill in the devices.
1422 */
1423 deps->count = count;
1424 count = 0;
1425 list_for_each_entry (dd, dm_table_get_devices(table), list)
1426 deps->dev[count++] = huge_encode_dev(dd->dm_dev->bdev->bd_dev);
1427
1428 param->data_size = param->data_start + needed;
1429 }
1430
1431 static int table_deps(struct dm_ioctl *param, size_t param_size)
1432 {
1433 struct mapped_device *md;
1434 struct dm_table *table;
1435 int srcu_idx;
1436
1437 md = find_device(param);
1438 if (!md)
1439 return -ENXIO;
1440
1441 __dev_status(md, param);
1442
1443 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1444 if (table)
1445 retrieve_deps(table, param, param_size);
1446 dm_put_live_table(md, srcu_idx);
1447
1448 dm_put(md);
1449
1450 return 0;
1451 }
1452
1453 /*
1454 * Return the status of a device as a text string for each
1455 * target.
1456 */
1457 static int table_status(struct dm_ioctl *param, size_t param_size)
1458 {
1459 struct mapped_device *md;
1460 struct dm_table *table;
1461 int srcu_idx;
1462
1463 md = find_device(param);
1464 if (!md)
1465 return -ENXIO;
1466
1467 __dev_status(md, param);
1468
1469 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1470 if (table)
1471 retrieve_status(table, param, param_size);
1472 dm_put_live_table(md, srcu_idx);
1473
1474 dm_put(md);
1475
1476 return 0;
1477 }
1478
1479 /*
1480 * Process device-mapper dependent messages. Messages prefixed with '@'
1481 * are processed by the DM core. All others are delivered to the target.
1482 * Returns a number <= 1 if message was processed by device mapper.
1483 * Returns 2 if message should be delivered to the target.
1484 */
1485 static int message_for_md(struct mapped_device *md, unsigned argc, char **argv,
1486 char *result, unsigned maxlen)
1487 {
1488 int r;
1489
1490 if (**argv != '@')
1491 return 2; /* no '@' prefix, deliver to target */
1492
1493 if (!strcasecmp(argv[0], "@cancel_deferred_remove")) {
1494 if (argc != 1) {
1495 DMERR("Invalid arguments for @cancel_deferred_remove");
1496 return -EINVAL;
1497 }
1498 return dm_cancel_deferred_remove(md);
1499 }
1500
1501 r = dm_stats_message(md, argc, argv, result, maxlen);
1502 if (r < 2)
1503 return r;
1504
1505 DMERR("Unsupported message sent to DM core: %s", argv[0]);
1506 return -EINVAL;
1507 }
1508
1509 /*
1510 * Pass a message to the target that's at the supplied device offset.
1511 */
1512 static int target_message(struct dm_ioctl *param, size_t param_size)
1513 {
1514 int r, argc;
1515 char **argv;
1516 struct mapped_device *md;
1517 struct dm_table *table;
1518 struct dm_target *ti;
1519 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1520 size_t maxlen;
1521 char *result = get_result_buffer(param, param_size, &maxlen);
1522 int srcu_idx;
1523
1524 md = find_device(param);
1525 if (!md)
1526 return -ENXIO;
1527
1528 if (tmsg < (struct dm_target_msg *) param->data ||
1529 invalid_str(tmsg->message, (void *) param + param_size)) {
1530 DMWARN("Invalid target message parameters.");
1531 r = -EINVAL;
1532 goto out;
1533 }
1534
1535 r = dm_split_args(&argc, &argv, tmsg->message);
1536 if (r) {
1537 DMWARN("Failed to split target message parameters");
1538 goto out;
1539 }
1540
1541 if (!argc) {
1542 DMWARN("Empty message received.");
1543 goto out_argv;
1544 }
1545
1546 r = message_for_md(md, argc, argv, result, maxlen);
1547 if (r <= 1)
1548 goto out_argv;
1549
1550 table = dm_get_live_table(md, &srcu_idx);
1551 if (!table)
1552 goto out_table;
1553
1554 if (dm_deleting_md(md)) {
1555 r = -ENXIO;
1556 goto out_table;
1557 }
1558
1559 ti = dm_table_find_target(table, tmsg->sector);
1560 if (!dm_target_is_valid(ti)) {
1561 DMWARN("Target message sector outside device.");
1562 r = -EINVAL;
1563 } else if (ti->type->message)
1564 r = ti->type->message(ti, argc, argv);
1565 else {
1566 DMWARN("Target type does not support messages");
1567 r = -EINVAL;
1568 }
1569
1570 out_table:
1571 dm_put_live_table(md, srcu_idx);
1572 out_argv:
1573 kfree(argv);
1574 out:
1575 if (r >= 0)
1576 __dev_status(md, param);
1577
1578 if (r == 1) {
1579 param->flags |= DM_DATA_OUT_FLAG;
1580 if (dm_message_test_buffer_overflow(result, maxlen))
1581 param->flags |= DM_BUFFER_FULL_FLAG;
1582 else
1583 param->data_size = param->data_start + strlen(result) + 1;
1584 r = 0;
1585 }
1586
1587 dm_put(md);
1588 return r;
1589 }
1590
1591 /*
1592 * The ioctl parameter block consists of two parts, a dm_ioctl struct
1593 * followed by a data buffer. This flag is set if the second part,
1594 * which has a variable size, is not used by the function processing
1595 * the ioctl.
1596 */
1597 #define IOCTL_FLAGS_NO_PARAMS 1
1598
1599 /*-----------------------------------------------------------------
1600 * Implementation of open/close/ioctl on the special char
1601 * device.
1602 *---------------------------------------------------------------*/
1603 static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags)
1604 {
1605 static struct {
1606 int cmd;
1607 int flags;
1608 ioctl_fn fn;
1609 } _ioctls[] = {
1610 {DM_VERSION_CMD, 0, NULL}, /* version is dealt with elsewhere */
1611 {DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS, remove_all},
1612 {DM_LIST_DEVICES_CMD, 0, list_devices},
1613
1614 {DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS, dev_create},
1615 {DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS, dev_remove},
1616 {DM_DEV_RENAME_CMD, 0, dev_rename},
1617 {DM_DEV_SUSPEND_CMD, IOCTL_FLAGS_NO_PARAMS, dev_suspend},
1618 {DM_DEV_STATUS_CMD, IOCTL_FLAGS_NO_PARAMS, dev_status},
1619 {DM_DEV_WAIT_CMD, 0, dev_wait},
1620
1621 {DM_TABLE_LOAD_CMD, 0, table_load},
1622 {DM_TABLE_CLEAR_CMD, IOCTL_FLAGS_NO_PARAMS, table_clear},
1623 {DM_TABLE_DEPS_CMD, 0, table_deps},
1624 {DM_TABLE_STATUS_CMD, 0, table_status},
1625
1626 {DM_LIST_VERSIONS_CMD, 0, list_versions},
1627
1628 {DM_TARGET_MSG_CMD, 0, target_message},
1629 {DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry}
1630 };
1631
1632 if (unlikely(cmd >= ARRAY_SIZE(_ioctls)))
1633 return NULL;
1634
1635 *ioctl_flags = _ioctls[cmd].flags;
1636 return _ioctls[cmd].fn;
1637 }
1638
1639 /*
1640 * As well as checking the version compatibility this always
1641 * copies the kernel interface version out.
1642 */
1643 static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1644 {
1645 uint32_t version[3];
1646 int r = 0;
1647
1648 if (copy_from_user(version, user->version, sizeof(version)))
1649 return -EFAULT;
1650
1651 if ((DM_VERSION_MAJOR != version[0]) ||
1652 (DM_VERSION_MINOR < version[1])) {
1653 DMWARN("ioctl interface mismatch: "
1654 "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1655 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1656 DM_VERSION_PATCHLEVEL,
1657 version[0], version[1], version[2], cmd);
1658 r = -EINVAL;
1659 }
1660
1661 /*
1662 * Fill in the kernel version.
1663 */
1664 version[0] = DM_VERSION_MAJOR;
1665 version[1] = DM_VERSION_MINOR;
1666 version[2] = DM_VERSION_PATCHLEVEL;
1667 if (copy_to_user(user->version, version, sizeof(version)))
1668 return -EFAULT;
1669
1670 return r;
1671 }
1672
1673 #define DM_PARAMS_KMALLOC 0x0001 /* Params alloced with kmalloc */
1674 #define DM_PARAMS_VMALLOC 0x0002 /* Params alloced with vmalloc */
1675 #define DM_WIPE_BUFFER 0x0010 /* Wipe input buffer before returning from ioctl */
1676
1677 static void free_params(struct dm_ioctl *param, size_t param_size, int param_flags)
1678 {
1679 if (param_flags & DM_WIPE_BUFFER)
1680 memset(param, 0, param_size);
1681
1682 if (param_flags & DM_PARAMS_KMALLOC)
1683 kfree(param);
1684 if (param_flags & DM_PARAMS_VMALLOC)
1685 vfree(param);
1686 }
1687
1688 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel,
1689 int ioctl_flags,
1690 struct dm_ioctl **param, int *param_flags)
1691 {
1692 struct dm_ioctl *dmi;
1693 int secure_data;
1694 const size_t minimum_data_size = sizeof(*param_kernel) - sizeof(param_kernel->data);
1695
1696 if (copy_from_user(param_kernel, user, minimum_data_size))
1697 return -EFAULT;
1698
1699 if (param_kernel->data_size < minimum_data_size)
1700 return -EINVAL;
1701
1702 secure_data = param_kernel->flags & DM_SECURE_DATA_FLAG;
1703
1704 *param_flags = secure_data ? DM_WIPE_BUFFER : 0;
1705
1706 if (ioctl_flags & IOCTL_FLAGS_NO_PARAMS) {
1707 dmi = param_kernel;
1708 dmi->data_size = minimum_data_size;
1709 goto data_copied;
1710 }
1711
1712 /*
1713 * Try to avoid low memory issues when a device is suspended.
1714 * Use kmalloc() rather than vmalloc() when we can.
1715 */
1716 dmi = NULL;
1717 if (param_kernel->data_size <= KMALLOC_MAX_SIZE) {
1718 dmi = kmalloc(param_kernel->data_size, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN);
1719 if (dmi)
1720 *param_flags |= DM_PARAMS_KMALLOC;
1721 }
1722
1723 if (!dmi) {
1724 unsigned noio_flag;
1725 noio_flag = memalloc_noio_save();
1726 dmi = __vmalloc(param_kernel->data_size, GFP_NOIO | __GFP_HIGH | __GFP_HIGHMEM, PAGE_KERNEL);
1727 memalloc_noio_restore(noio_flag);
1728 if (dmi)
1729 *param_flags |= DM_PARAMS_VMALLOC;
1730 }
1731
1732 if (!dmi) {
1733 if (secure_data && clear_user(user, param_kernel->data_size))
1734 return -EFAULT;
1735 return -ENOMEM;
1736 }
1737
1738 if (copy_from_user(dmi, user, param_kernel->data_size))
1739 goto bad;
1740
1741 data_copied:
1742 /*
1743 * Abort if something changed the ioctl data while it was being copied.
1744 */
1745 if (dmi->data_size != param_kernel->data_size) {
1746 DMERR("rejecting ioctl: data size modified while processing parameters");
1747 goto bad;
1748 }
1749
1750 /* Wipe the user buffer so we do not return it to userspace */
1751 if (secure_data && clear_user(user, param_kernel->data_size))
1752 goto bad;
1753
1754 *param = dmi;
1755 return 0;
1756
1757 bad:
1758 free_params(dmi, param_kernel->data_size, *param_flags);
1759
1760 return -EFAULT;
1761 }
1762
1763 static int validate_params(uint cmd, struct dm_ioctl *param)
1764 {
1765 /* Always clear this flag */
1766 param->flags &= ~DM_BUFFER_FULL_FLAG;
1767 param->flags &= ~DM_UEVENT_GENERATED_FLAG;
1768 param->flags &= ~DM_SECURE_DATA_FLAG;
1769 param->flags &= ~DM_DATA_OUT_FLAG;
1770
1771 /* Ignores parameters */
1772 if (cmd == DM_REMOVE_ALL_CMD ||
1773 cmd == DM_LIST_DEVICES_CMD ||
1774 cmd == DM_LIST_VERSIONS_CMD)
1775 return 0;
1776
1777 if ((cmd == DM_DEV_CREATE_CMD)) {
1778 if (!*param->name) {
1779 DMWARN("name not supplied when creating device");
1780 return -EINVAL;
1781 }
1782 } else if ((*param->uuid && *param->name)) {
1783 DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
1784 return -EINVAL;
1785 }
1786
1787 /* Ensure strings are terminated */
1788 param->name[DM_NAME_LEN - 1] = '\0';
1789 param->uuid[DM_UUID_LEN - 1] = '\0';
1790
1791 return 0;
1792 }
1793
1794 static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
1795 {
1796 int r = 0;
1797 int ioctl_flags;
1798 int param_flags;
1799 unsigned int cmd;
1800 struct dm_ioctl *uninitialized_var(param);
1801 ioctl_fn fn = NULL;
1802 size_t input_param_size;
1803 struct dm_ioctl param_kernel;
1804
1805 /* only root can play with this */
1806 if (!capable(CAP_SYS_ADMIN))
1807 return -EACCES;
1808
1809 if (_IOC_TYPE(command) != DM_IOCTL)
1810 return -ENOTTY;
1811
1812 cmd = _IOC_NR(command);
1813
1814 /*
1815 * Check the interface version passed in. This also
1816 * writes out the kernel's interface version.
1817 */
1818 r = check_version(cmd, user);
1819 if (r)
1820 return r;
1821
1822 /*
1823 * Nothing more to do for the version command.
1824 */
1825 if (cmd == DM_VERSION_CMD)
1826 return 0;
1827
1828 fn = lookup_ioctl(cmd, &ioctl_flags);
1829 if (!fn) {
1830 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1831 return -ENOTTY;
1832 }
1833
1834 /*
1835 * Copy the parameters into kernel space.
1836 */
1837 r = copy_params(user, &param_kernel, ioctl_flags, &param, &param_flags);
1838
1839 if (r)
1840 return r;
1841
1842 input_param_size = param->data_size;
1843 r = validate_params(cmd, param);
1844 if (r)
1845 goto out;
1846
1847 param->data_size = sizeof(*param);
1848 r = fn(param, input_param_size);
1849
1850 if (unlikely(param->flags & DM_BUFFER_FULL_FLAG) &&
1851 unlikely(ioctl_flags & IOCTL_FLAGS_NO_PARAMS))
1852 DMERR("ioctl %d tried to output some data but has IOCTL_FLAGS_NO_PARAMS set", cmd);
1853
1854 /*
1855 * Copy the results back to userland.
1856 */
1857 if (!r && copy_to_user(user, param, param->data_size))
1858 r = -EFAULT;
1859
1860 out:
1861 free_params(param, input_param_size, param_flags);
1862 return r;
1863 }
1864
1865 static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
1866 {
1867 return (long)ctl_ioctl(command, (struct dm_ioctl __user *)u);
1868 }
1869
1870 #ifdef CONFIG_COMPAT
1871 static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
1872 {
1873 return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
1874 }
1875 #else
1876 #define dm_compat_ctl_ioctl NULL
1877 #endif
1878
1879 static const struct file_operations _ctl_fops = {
1880 .open = nonseekable_open,
1881 .unlocked_ioctl = dm_ctl_ioctl,
1882 .compat_ioctl = dm_compat_ctl_ioctl,
1883 .owner = THIS_MODULE,
1884 .llseek = noop_llseek,
1885 };
1886
1887 static struct miscdevice _dm_misc = {
1888 .minor = MAPPER_CTRL_MINOR,
1889 .name = DM_NAME,
1890 .nodename = DM_DIR "/" DM_CONTROL_NODE,
1891 .fops = &_ctl_fops
1892 };
1893
1894 MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
1895 MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
1896
1897 /*
1898 * Create misc character device and link to DM_DIR/control.
1899 */
1900 int __init dm_interface_init(void)
1901 {
1902 int r;
1903
1904 r = dm_hash_init();
1905 if (r)
1906 return r;
1907
1908 r = misc_register(&_dm_misc);
1909 if (r) {
1910 DMERR("misc_register failed for control device");
1911 dm_hash_exit();
1912 return r;
1913 }
1914
1915 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
1916 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
1917 DM_DRIVER_EMAIL);
1918 return 0;
1919 }
1920
1921 void dm_interface_exit(void)
1922 {
1923 misc_deregister(&_dm_misc);
1924 dm_hash_exit();
1925 }
1926
1927 /**
1928 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
1929 * @md: Pointer to mapped_device
1930 * @name: Buffer (size DM_NAME_LEN) for name
1931 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
1932 */
1933 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
1934 {
1935 int r = 0;
1936 struct hash_cell *hc;
1937
1938 if (!md)
1939 return -ENXIO;
1940
1941 mutex_lock(&dm_hash_cells_mutex);
1942 hc = dm_get_mdptr(md);
1943 if (!hc || hc->md != md) {
1944 r = -ENXIO;
1945 goto out;
1946 }
1947
1948 if (name)
1949 strcpy(name, hc->name);
1950 if (uuid)
1951 strcpy(uuid, hc->uuid ? : "");
1952
1953 out:
1954 mutex_unlock(&dm_hash_cells_mutex);
1955
1956 return r;
1957 }
Linux with added FPC-III support