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staging: rtl8188eu: rename HalSetBrateCfg() - style
[linux/fpc-iii.git] / drivers / md / dm-ioctl.c
blobb810ea77e6b162df29b0f3f57605317000461285
1 /*
2 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
3 * Copyright (C) 2004 - 2006 Red Hat, Inc. All rights reserved.
4 *
5 * This file is released under the GPL.
6 */
7
8 #include "dm-core.h"
9
10 #include <linux/module.h>
11 #include <linux/vmalloc.h>
12 #include <linux/miscdevice.h>
13 #include <linux/sched/mm.h>
14 #include <linux/init.h>
15 #include <linux/wait.h>
16 #include <linux/slab.h>
17 #include <linux/dm-ioctl.h>
18 #include <linux/hdreg.h>
19 #include <linux/compat.h>
20
21 #include <linux/uaccess.h>
22
23 #define DM_MSG_PREFIX "ioctl"
24 #define DM_DRIVER_EMAIL "dm-devel@redhat.com"
25
26 struct dm_file {
27 /*
28 * poll will wait until the global event number is greater than
29 * this value.
30 */
31 volatile unsigned global_event_nr;
32 };
33
34 /*-----------------------------------------------------------------
35 * The ioctl interface needs to be able to look up devices by
36 * name or uuid.
37 *---------------------------------------------------------------*/
38 struct hash_cell {
39 struct list_head name_list;
40 struct list_head uuid_list;
41
42 char *name;
43 char *uuid;
44 struct mapped_device *md;
45 struct dm_table *new_map;
46 };
47
48 struct vers_iter {
49 size_t param_size;
50 struct dm_target_versions *vers, *old_vers;
51 char *end;
52 uint32_t flags;
53 };
54
55
56 #define NUM_BUCKETS 64
57 #define MASK_BUCKETS (NUM_BUCKETS - 1)
58 static struct list_head _name_buckets[NUM_BUCKETS];
59 static struct list_head _uuid_buckets[NUM_BUCKETS];
60
61 static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred);
62
63 /*
64 * Guards access to both hash tables.
65 */
66 static DECLARE_RWSEM(_hash_lock);
67
68 /*
69 * Protects use of mdptr to obtain hash cell name and uuid from mapped device.
70 */
71 static DEFINE_MUTEX(dm_hash_cells_mutex);
72
73 static void init_buckets(struct list_head *buckets)
74 {
75 unsigned int i;
76
77 for (i = 0; i < NUM_BUCKETS; i++)
78 INIT_LIST_HEAD(buckets + i);
79 }
80
81 static int dm_hash_init(void)
82 {
83 init_buckets(_name_buckets);
84 init_buckets(_uuid_buckets);
85 return 0;
86 }
87
88 static void dm_hash_exit(void)
89 {
90 dm_hash_remove_all(false, false, false);
91 }
92
93 /*-----------------------------------------------------------------
94 * Hash function:
95 * We're not really concerned with the str hash function being
96 * fast since it's only used by the ioctl interface.
97 *---------------------------------------------------------------*/
98 static unsigned int hash_str(const char *str)
99 {
100 const unsigned int hash_mult = 2654435387U;
101 unsigned int h = 0;
102
103 while (*str)
104 h = (h + (unsigned int) *str++) * hash_mult;
105
106 return h & MASK_BUCKETS;
107 }
108
109 /*-----------------------------------------------------------------
110 * Code for looking up a device by name
111 *---------------------------------------------------------------*/
112 static struct hash_cell *__get_name_cell(const char *str)
113 {
114 struct hash_cell *hc;
115 unsigned int h = hash_str(str);
116
117 list_for_each_entry (hc, _name_buckets + h, name_list)
118 if (!strcmp(hc->name, str)) {
119 dm_get(hc->md);
120 return hc;
121 }
122
123 return NULL;
124 }
125
126 static struct hash_cell *__get_uuid_cell(const char *str)
127 {
128 struct hash_cell *hc;
129 unsigned int h = hash_str(str);
130
131 list_for_each_entry (hc, _uuid_buckets + h, uuid_list)
132 if (!strcmp(hc->uuid, str)) {
133 dm_get(hc->md);
134 return hc;
135 }
136
137 return NULL;
138 }
139
140 static struct hash_cell *__get_dev_cell(uint64_t dev)
141 {
142 struct mapped_device *md;
143 struct hash_cell *hc;
144
145 md = dm_get_md(huge_decode_dev(dev));
146 if (!md)
147 return NULL;
148
149 hc = dm_get_mdptr(md);
150 if (!hc) {
151 dm_put(md);
152 return NULL;
153 }
154
155 return hc;
156 }
157
158 /*-----------------------------------------------------------------
159 * Inserting, removing and renaming a device.
160 *---------------------------------------------------------------*/
161 static struct hash_cell *alloc_cell(const char *name, const char *uuid,
162 struct mapped_device *md)
163 {
164 struct hash_cell *hc;
165
166 hc = kmalloc(sizeof(*hc), GFP_KERNEL);
167 if (!hc)
168 return NULL;
169
170 hc->name = kstrdup(name, GFP_KERNEL);
171 if (!hc->name) {
172 kfree(hc);
173 return NULL;
174 }
175
176 if (!uuid)
177 hc->uuid = NULL;
178
179 else {
180 hc->uuid = kstrdup(uuid, GFP_KERNEL);
181 if (!hc->uuid) {
182 kfree(hc->name);
183 kfree(hc);
184 return NULL;
185 }
186 }
187
188 INIT_LIST_HEAD(&hc->name_list);
189 INIT_LIST_HEAD(&hc->uuid_list);
190 hc->md = md;
191 hc->new_map = NULL;
192 return hc;
193 }
194
195 static void free_cell(struct hash_cell *hc)
196 {
197 if (hc) {
198 kfree(hc->name);
199 kfree(hc->uuid);
200 kfree(hc);
201 }
202 }
203
204 /*
205 * The kdev_t and uuid of a device can never change once it is
206 * initially inserted.
207 */
208 static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
209 {
210 struct hash_cell *cell, *hc;
211
212 /*
213 * Allocate the new cells.
214 */
215 cell = alloc_cell(name, uuid, md);
216 if (!cell)
217 return -ENOMEM;
218
219 /*
220 * Insert the cell into both hash tables.
221 */
222 down_write(&_hash_lock);
223 hc = __get_name_cell(name);
224 if (hc) {
225 dm_put(hc->md);
226 goto bad;
227 }
228
229 list_add(&cell->name_list, _name_buckets + hash_str(name));
230
231 if (uuid) {
232 hc = __get_uuid_cell(uuid);
233 if (hc) {
234 list_del(&cell->name_list);
235 dm_put(hc->md);
236 goto bad;
237 }
238 list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
239 }
240 dm_get(md);
241 mutex_lock(&dm_hash_cells_mutex);
242 dm_set_mdptr(md, cell);
243 mutex_unlock(&dm_hash_cells_mutex);
244 up_write(&_hash_lock);
245
246 return 0;
247
248 bad:
249 up_write(&_hash_lock);
250 free_cell(cell);
251 return -EBUSY;
252 }
253
254 static struct dm_table *__hash_remove(struct hash_cell *hc)
255 {
256 struct dm_table *table;
257 int srcu_idx;
258
259 /* remove from the dev hash */
260 list_del(&hc->uuid_list);
261 list_del(&hc->name_list);
262 mutex_lock(&dm_hash_cells_mutex);
263 dm_set_mdptr(hc->md, NULL);
264 mutex_unlock(&dm_hash_cells_mutex);
265
266 table = dm_get_live_table(hc->md, &srcu_idx);
267 if (table)
268 dm_table_event(table);
269 dm_put_live_table(hc->md, srcu_idx);
270
271 table = NULL;
272 if (hc->new_map)
273 table = hc->new_map;
274 dm_put(hc->md);
275 free_cell(hc);
276
277 return table;
278 }
279
280 static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred)
281 {
282 int i, dev_skipped;
283 struct hash_cell *hc;
284 struct mapped_device *md;
285 struct dm_table *t;
286
287 retry:
288 dev_skipped = 0;
289
290 down_write(&_hash_lock);
291
292 for (i = 0; i < NUM_BUCKETS; i++) {
293 list_for_each_entry(hc, _name_buckets + i, name_list) {
294 md = hc->md;
295 dm_get(md);
296
297 if (keep_open_devices &&
298 dm_lock_for_deletion(md, mark_deferred, only_deferred)) {
299 dm_put(md);
300 dev_skipped++;
301 continue;
302 }
303
304 t = __hash_remove(hc);
305
306 up_write(&_hash_lock);
307
308 if (t) {
309 dm_sync_table(md);
310 dm_table_destroy(t);
311 }
312 dm_put(md);
313 if (likely(keep_open_devices))
314 dm_destroy(md);
315 else
316 dm_destroy_immediate(md);
317
318 /*
319 * Some mapped devices may be using other mapped
320 * devices, so repeat until we make no further
321 * progress. If a new mapped device is created
322 * here it will also get removed.
323 */
324 goto retry;
325 }
326 }
327
328 up_write(&_hash_lock);
329
330 if (dev_skipped)
331 DMWARN("remove_all left %d open device(s)", dev_skipped);
332 }
333
334 /*
335 * Set the uuid of a hash_cell that isn't already set.
336 */
337 static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
338 {
339 mutex_lock(&dm_hash_cells_mutex);
340 hc->uuid = new_uuid;
341 mutex_unlock(&dm_hash_cells_mutex);
342
343 list_add(&hc->uuid_list, _uuid_buckets + hash_str(new_uuid));
344 }
345
346 /*
347 * Changes the name of a hash_cell and returns the old name for
348 * the caller to free.
349 */
350 static char *__change_cell_name(struct hash_cell *hc, char *new_name)
351 {
352 char *old_name;
353
354 /*
355 * Rename and move the name cell.
356 */
357 list_del(&hc->name_list);
358 old_name = hc->name;
359
360 mutex_lock(&dm_hash_cells_mutex);
361 hc->name = new_name;
362 mutex_unlock(&dm_hash_cells_mutex);
363
364 list_add(&hc->name_list, _name_buckets + hash_str(new_name));
365
366 return old_name;
367 }
368
369 static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
370 const char *new)
371 {
372 char *new_data, *old_name = NULL;
373 struct hash_cell *hc;
374 struct dm_table *table;
375 struct mapped_device *md;
376 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
377 int srcu_idx;
378
379 /*
380 * duplicate new.
381 */
382 new_data = kstrdup(new, GFP_KERNEL);
383 if (!new_data)
384 return ERR_PTR(-ENOMEM);
385
386 down_write(&_hash_lock);
387
388 /*
389 * Is new free ?
390 */
391 if (change_uuid)
392 hc = __get_uuid_cell(new);
393 else
394 hc = __get_name_cell(new);
395
396 if (hc) {
397 DMWARN("Unable to change %s on mapped device %s to one that "
398 "already exists: %s",
399 change_uuid ? "uuid" : "name",
400 param->name, new);
401 dm_put(hc->md);
402 up_write(&_hash_lock);
403 kfree(new_data);
404 return ERR_PTR(-EBUSY);
405 }
406
407 /*
408 * Is there such a device as 'old' ?
409 */
410 hc = __get_name_cell(param->name);
411 if (!hc) {
412 DMWARN("Unable to rename non-existent device, %s to %s%s",
413 param->name, change_uuid ? "uuid " : "", new);
414 up_write(&_hash_lock);
415 kfree(new_data);
416 return ERR_PTR(-ENXIO);
417 }
418
419 /*
420 * Does this device already have a uuid?
421 */
422 if (change_uuid && hc->uuid) {
423 DMWARN("Unable to change uuid of mapped device %s to %s "
424 "because uuid is already set to %s",
425 param->name, new, hc->uuid);
426 dm_put(hc->md);
427 up_write(&_hash_lock);
428 kfree(new_data);
429 return ERR_PTR(-EINVAL);
430 }
431
432 if (change_uuid)
433 __set_cell_uuid(hc, new_data);
434 else
435 old_name = __change_cell_name(hc, new_data);
436
437 /*
438 * Wake up any dm event waiters.
439 */
440 table = dm_get_live_table(hc->md, &srcu_idx);
441 if (table)
442 dm_table_event(table);
443 dm_put_live_table(hc->md, srcu_idx);
444
445 if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr))
446 param->flags |= DM_UEVENT_GENERATED_FLAG;
447
448 md = hc->md;
449 up_write(&_hash_lock);
450 kfree(old_name);
451
452 return md;
453 }
454
455 void dm_deferred_remove(void)
456 {
457 dm_hash_remove_all(true, false, true);
458 }
459
460 /*-----------------------------------------------------------------
461 * Implementation of the ioctl commands
462 *---------------------------------------------------------------*/
463 /*
464 * All the ioctl commands get dispatched to functions with this
465 * prototype.
466 */
467 typedef int (*ioctl_fn)(struct file *filp, struct dm_ioctl *param, size_t param_size);
468
469 static int remove_all(struct file *filp, struct dm_ioctl *param, size_t param_size)
470 {
471 dm_hash_remove_all(true, !!(param->flags & DM_DEFERRED_REMOVE), false);
472 param->data_size = 0;
473 return 0;
474 }
475
476 /*
477 * Round up the ptr to an 8-byte boundary.
478 */
479 #define ALIGN_MASK 7
480 static inline size_t align_val(size_t val)
481 {
482 return (val + ALIGN_MASK) & ~ALIGN_MASK;
483 }
484 static inline void *align_ptr(void *ptr)
485 {
486 return (void *)align_val((size_t)ptr);
487 }
488
489 /*
490 * Retrieves the data payload buffer from an already allocated
491 * struct dm_ioctl.
492 */
493 static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
494 size_t *len)
495 {
496 param->data_start = align_ptr(param + 1) - (void *) param;
497
498 if (param->data_start < param_size)
499 *len = param_size - param->data_start;
500 else
501 *len = 0;
502
503 return ((void *) param) + param->data_start;
504 }
505
506 static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_size)
507 {
508 unsigned int i;
509 struct hash_cell *hc;
510 size_t len, needed = 0;
511 struct gendisk *disk;
512 struct dm_name_list *orig_nl, *nl, *old_nl = NULL;
513 uint32_t *event_nr;
514
515 down_write(&_hash_lock);
516
517 /*
518 * Loop through all the devices working out how much
519 * space we need.
520 */
521 for (i = 0; i < NUM_BUCKETS; i++) {
522 list_for_each_entry (hc, _name_buckets + i, name_list) {
523 needed += align_val(offsetof(struct dm_name_list, name) + strlen(hc->name) + 1);
524 needed += align_val(sizeof(uint32_t));
525 }
526 }
527
528 /*
529 * Grab our output buffer.
530 */
531 nl = orig_nl = get_result_buffer(param, param_size, &len);
532 if (len < needed) {
533 param->flags |= DM_BUFFER_FULL_FLAG;
534 goto out;
535 }
536 param->data_size = param->data_start + needed;
537
538 nl->dev = 0; /* Flags no data */
539
540 /*
541 * Now loop through filling out the names.
542 */
543 for (i = 0; i < NUM_BUCKETS; i++) {
544 list_for_each_entry (hc, _name_buckets + i, name_list) {
545 if (old_nl)
546 old_nl->next = (uint32_t) ((void *) nl -
547 (void *) old_nl);
548 disk = dm_disk(hc->md);
549 nl->dev = huge_encode_dev(disk_devt(disk));
550 nl->next = 0;
551 strcpy(nl->name, hc->name);
552
553 old_nl = nl;
554 event_nr = align_ptr(nl->name + strlen(hc->name) + 1);
555 *event_nr = dm_get_event_nr(hc->md);
556 nl = align_ptr(event_nr + 1);
557 }
558 }
559 /*
560 * If mismatch happens, security may be compromised due to buffer
561 * overflow, so it's better to crash.
562 */
563 BUG_ON((char *)nl - (char *)orig_nl != needed);
564
565 out:
566 up_write(&_hash_lock);
567 return 0;
568 }
569
570 static void list_version_get_needed(struct target_type *tt, void *needed_param)
571 {
572 size_t *needed = needed_param;
573
574 *needed += sizeof(struct dm_target_versions);
575 *needed += strlen(tt->name);
576 *needed += ALIGN_MASK;
577 }
578
579 static void list_version_get_info(struct target_type *tt, void *param)
580 {
581 struct vers_iter *info = param;
582
583 /* Check space - it might have changed since the first iteration */
584 if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
585 info->end) {
586
587 info->flags = DM_BUFFER_FULL_FLAG;
588 return;
589 }
590
591 if (info->old_vers)
592 info->old_vers->next = (uint32_t) ((void *)info->vers -
593 (void *)info->old_vers);
594 info->vers->version[0] = tt->version[0];
595 info->vers->version[1] = tt->version[1];
596 info->vers->version[2] = tt->version[2];
597 info->vers->next = 0;
598 strcpy(info->vers->name, tt->name);
599
600 info->old_vers = info->vers;
601 info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
602 }
603
604 static int list_versions(struct file *filp, struct dm_ioctl *param, size_t param_size)
605 {
606 size_t len, needed = 0;
607 struct dm_target_versions *vers;
608 struct vers_iter iter_info;
609
610 /*
611 * Loop through all the devices working out how much
612 * space we need.
613 */
614 dm_target_iterate(list_version_get_needed, &needed);
615
616 /*
617 * Grab our output buffer.
618 */
619 vers = get_result_buffer(param, param_size, &len);
620 if (len < needed) {
621 param->flags |= DM_BUFFER_FULL_FLAG;
622 goto out;
623 }
624 param->data_size = param->data_start + needed;
625
626 iter_info.param_size = param_size;
627 iter_info.old_vers = NULL;
628 iter_info.vers = vers;
629 iter_info.flags = 0;
630 iter_info.end = (char *)vers+len;
631
632 /*
633 * Now loop through filling out the names & versions.
634 */
635 dm_target_iterate(list_version_get_info, &iter_info);
636 param->flags |= iter_info.flags;
637
638 out:
639 return 0;
640 }
641
642 static int check_name(const char *name)
643 {
644 if (strchr(name, '/')) {
645 DMWARN("invalid device name");
646 return -EINVAL;
647 }
648
649 return 0;
650 }
651
652 /*
653 * On successful return, the caller must not attempt to acquire
654 * _hash_lock without first calling dm_put_live_table, because dm_table_destroy
655 * waits for this dm_put_live_table and could be called under this lock.
656 */
657 static struct dm_table *dm_get_inactive_table(struct mapped_device *md, int *srcu_idx)
658 {
659 struct hash_cell *hc;
660 struct dm_table *table = NULL;
661
662 /* increment rcu count, we don't care about the table pointer */
663 dm_get_live_table(md, srcu_idx);
664
665 down_read(&_hash_lock);
666 hc = dm_get_mdptr(md);
667 if (!hc || hc->md != md) {
668 DMWARN("device has been removed from the dev hash table.");
669 goto out;
670 }
671
672 table = hc->new_map;
673
674 out:
675 up_read(&_hash_lock);
676
677 return table;
678 }
679
680 static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
681 struct dm_ioctl *param,
682 int *srcu_idx)
683 {
684 return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
685 dm_get_inactive_table(md, srcu_idx) : dm_get_live_table(md, srcu_idx);
686 }
687
688 /*
689 * Fills in a dm_ioctl structure, ready for sending back to
690 * userland.
691 */
692 static void __dev_status(struct mapped_device *md, struct dm_ioctl *param)
693 {
694 struct gendisk *disk = dm_disk(md);
695 struct dm_table *table;
696 int srcu_idx;
697
698 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
699 DM_ACTIVE_PRESENT_FLAG | DM_INTERNAL_SUSPEND_FLAG);
700
701 if (dm_suspended_md(md))
702 param->flags |= DM_SUSPEND_FLAG;
703
704 if (dm_suspended_internally_md(md))
705 param->flags |= DM_INTERNAL_SUSPEND_FLAG;
706
707 if (dm_test_deferred_remove_flag(md))
708 param->flags |= DM_DEFERRED_REMOVE;
709
710 param->dev = huge_encode_dev(disk_devt(disk));
711
712 /*
713 * Yes, this will be out of date by the time it gets back
714 * to userland, but it is still very useful for
715 * debugging.
716 */
717 param->open_count = dm_open_count(md);
718
719 param->event_nr = dm_get_event_nr(md);
720 param->target_count = 0;
721
722 table = dm_get_live_table(md, &srcu_idx);
723 if (table) {
724 if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
725 if (get_disk_ro(disk))
726 param->flags |= DM_READONLY_FLAG;
727 param->target_count = dm_table_get_num_targets(table);
728 }
729
730 param->flags |= DM_ACTIVE_PRESENT_FLAG;
731 }
732 dm_put_live_table(md, srcu_idx);
733
734 if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
735 int srcu_idx;
736 table = dm_get_inactive_table(md, &srcu_idx);
737 if (table) {
738 if (!(dm_table_get_mode(table) & FMODE_WRITE))
739 param->flags |= DM_READONLY_FLAG;
740 param->target_count = dm_table_get_num_targets(table);
741 }
742 dm_put_live_table(md, srcu_idx);
743 }
744 }
745
746 static int dev_create(struct file *filp, struct dm_ioctl *param, size_t param_size)
747 {
748 int r, m = DM_ANY_MINOR;
749 struct mapped_device *md;
750
751 r = check_name(param->name);
752 if (r)
753 return r;
754
755 if (param->flags & DM_PERSISTENT_DEV_FLAG)
756 m = MINOR(huge_decode_dev(param->dev));
757
758 r = dm_create(m, &md);
759 if (r)
760 return r;
761
762 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
763 if (r) {
764 dm_put(md);
765 dm_destroy(md);
766 return r;
767 }
768
769 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
770
771 __dev_status(md, param);
772
773 dm_put(md);
774
775 return 0;
776 }
777
778 /*
779 * Always use UUID for lookups if it's present, otherwise use name or dev.
780 */
781 static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
782 {
783 struct hash_cell *hc = NULL;
784
785 if (*param->uuid) {
786 if (*param->name || param->dev)
787 return NULL;
788
789 hc = __get_uuid_cell(param->uuid);
790 if (!hc)
791 return NULL;
792 } else if (*param->name) {
793 if (param->dev)
794 return NULL;
795
796 hc = __get_name_cell(param->name);
797 if (!hc)
798 return NULL;
799 } else if (param->dev) {
800 hc = __get_dev_cell(param->dev);
801 if (!hc)
802 return NULL;
803 } else
804 return NULL;
805
806 /*
807 * Sneakily write in both the name and the uuid
808 * while we have the cell.
809 */
810 strlcpy(param->name, hc->name, sizeof(param->name));
811 if (hc->uuid)
812 strlcpy(param->uuid, hc->uuid, sizeof(param->uuid));
813 else
814 param->uuid[0] = '\0';
815
816 if (hc->new_map)
817 param->flags |= DM_INACTIVE_PRESENT_FLAG;
818 else
819 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
820
821 return hc;
822 }
823
824 static struct mapped_device *find_device(struct dm_ioctl *param)
825 {
826 struct hash_cell *hc;
827 struct mapped_device *md = NULL;
828
829 down_read(&_hash_lock);
830 hc = __find_device_hash_cell(param);
831 if (hc)
832 md = hc->md;
833 up_read(&_hash_lock);
834
835 return md;
836 }
837
838 static int dev_remove(struct file *filp, struct dm_ioctl *param, size_t param_size)
839 {
840 struct hash_cell *hc;
841 struct mapped_device *md;
842 int r;
843 struct dm_table *t;
844
845 down_write(&_hash_lock);
846 hc = __find_device_hash_cell(param);
847
848 if (!hc) {
849 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
850 up_write(&_hash_lock);
851 return -ENXIO;
852 }
853
854 md = hc->md;
855
856 /*
857 * Ensure the device is not open and nothing further can open it.
858 */
859 r = dm_lock_for_deletion(md, !!(param->flags & DM_DEFERRED_REMOVE), false);
860 if (r) {
861 if (r == -EBUSY && param->flags & DM_DEFERRED_REMOVE) {
862 up_write(&_hash_lock);
863 dm_put(md);
864 return 0;
865 }
866 DMDEBUG_LIMIT("unable to remove open device %s", hc->name);
867 up_write(&_hash_lock);
868 dm_put(md);
869 return r;
870 }
871
872 t = __hash_remove(hc);
873 up_write(&_hash_lock);
874
875 if (t) {
876 dm_sync_table(md);
877 dm_table_destroy(t);
878 }
879
880 param->flags &= ~DM_DEFERRED_REMOVE;
881
882 if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr))
883 param->flags |= DM_UEVENT_GENERATED_FLAG;
884
885 dm_put(md);
886 dm_destroy(md);
887 return 0;
888 }
889
890 /*
891 * Check a string doesn't overrun the chunk of
892 * memory we copied from userland.
893 */
894 static int invalid_str(char *str, void *end)
895 {
896 while ((void *) str < end)
897 if (!*str++)
898 return 0;
899
900 return -EINVAL;
901 }
902
903 static int dev_rename(struct file *filp, struct dm_ioctl *param, size_t param_size)
904 {
905 int r;
906 char *new_data = (char *) param + param->data_start;
907 struct mapped_device *md;
908 unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
909
910 if (new_data < param->data ||
911 invalid_str(new_data, (void *) param + param_size) || !*new_data ||
912 strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
913 DMWARN("Invalid new mapped device name or uuid string supplied.");
914 return -EINVAL;
915 }
916
917 if (!change_uuid) {
918 r = check_name(new_data);
919 if (r)
920 return r;
921 }
922
923 md = dm_hash_rename(param, new_data);
924 if (IS_ERR(md))
925 return PTR_ERR(md);
926
927 __dev_status(md, param);
928 dm_put(md);
929
930 return 0;
931 }
932
933 static int dev_set_geometry(struct file *filp, struct dm_ioctl *param, size_t param_size)
934 {
935 int r = -EINVAL, x;
936 struct mapped_device *md;
937 struct hd_geometry geometry;
938 unsigned long indata[4];
939 char *geostr = (char *) param + param->data_start;
940 char dummy;
941
942 md = find_device(param);
943 if (!md)
944 return -ENXIO;
945
946 if (geostr < param->data ||
947 invalid_str(geostr, (void *) param + param_size)) {
948 DMWARN("Invalid geometry supplied.");
949 goto out;
950 }
951
952 x = sscanf(geostr, "%lu %lu %lu %lu%c", indata,
953 indata + 1, indata + 2, indata + 3, &dummy);
954
955 if (x != 4) {
956 DMWARN("Unable to interpret geometry settings.");
957 goto out;
958 }
959
960 if (indata[0] > 65535 || indata[1] > 255 ||
961 indata[2] > 255 || indata[3] > ULONG_MAX) {
962 DMWARN("Geometry exceeds range limits.");
963 goto out;
964 }
965
966 geometry.cylinders = indata[0];
967 geometry.heads = indata[1];
968 geometry.sectors = indata[2];
969 geometry.start = indata[3];
970
971 r = dm_set_geometry(md, &geometry);
972
973 param->data_size = 0;
974
975 out:
976 dm_put(md);
977 return r;
978 }
979
980 static int do_suspend(struct dm_ioctl *param)
981 {
982 int r = 0;
983 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
984 struct mapped_device *md;
985
986 md = find_device(param);
987 if (!md)
988 return -ENXIO;
989
990 if (param->flags & DM_SKIP_LOCKFS_FLAG)
991 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
992 if (param->flags & DM_NOFLUSH_FLAG)
993 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
994
995 if (!dm_suspended_md(md)) {
996 r = dm_suspend(md, suspend_flags);
997 if (r)
998 goto out;
999 }
1000
1001 __dev_status(md, param);
1002
1003 out:
1004 dm_put(md);
1005
1006 return r;
1007 }
1008
1009 static int do_resume(struct dm_ioctl *param)
1010 {
1011 int r = 0;
1012 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
1013 struct hash_cell *hc;
1014 struct mapped_device *md;
1015 struct dm_table *new_map, *old_map = NULL;
1016
1017 down_write(&_hash_lock);
1018
1019 hc = __find_device_hash_cell(param);
1020 if (!hc) {
1021 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1022 up_write(&_hash_lock);
1023 return -ENXIO;
1024 }
1025
1026 md = hc->md;
1027
1028 new_map = hc->new_map;
1029 hc->new_map = NULL;
1030 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1031
1032 up_write(&_hash_lock);
1033
1034 /* Do we need to load a new map ? */
1035 if (new_map) {
1036 /* Suspend if it isn't already suspended */
1037 if (param->flags & DM_SKIP_LOCKFS_FLAG)
1038 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
1039 if (param->flags & DM_NOFLUSH_FLAG)
1040 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
1041 if (!dm_suspended_md(md))
1042 dm_suspend(md, suspend_flags);
1043
1044 old_map = dm_swap_table(md, new_map);
1045 if (IS_ERR(old_map)) {
1046 dm_sync_table(md);
1047 dm_table_destroy(new_map);
1048 dm_put(md);
1049 return PTR_ERR(old_map);
1050 }
1051
1052 if (dm_table_get_mode(new_map) & FMODE_WRITE)
1053 set_disk_ro(dm_disk(md), 0);
1054 else
1055 set_disk_ro(dm_disk(md), 1);
1056 }
1057
1058 if (dm_suspended_md(md)) {
1059 r = dm_resume(md);
1060 if (!r && !dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr))
1061 param->flags |= DM_UEVENT_GENERATED_FLAG;
1062 }
1063
1064 /*
1065 * Since dm_swap_table synchronizes RCU, nobody should be in
1066 * read-side critical section already.
1067 */
1068 if (old_map)
1069 dm_table_destroy(old_map);
1070
1071 if (!r)
1072 __dev_status(md, param);
1073
1074 dm_put(md);
1075 return r;
1076 }
1077
1078 /*
1079 * Set or unset the suspension state of a device.
1080 * If the device already is in the requested state we just return its status.
1081 */
1082 static int dev_suspend(struct file *filp, struct dm_ioctl *param, size_t param_size)
1083 {
1084 if (param->flags & DM_SUSPEND_FLAG)
1085 return do_suspend(param);
1086
1087 return do_resume(param);
1088 }
1089
1090 /*
1091 * Copies device info back to user space, used by
1092 * the create and info ioctls.
1093 */
1094 static int dev_status(struct file *filp, struct dm_ioctl *param, size_t param_size)
1095 {
1096 struct mapped_device *md;
1097
1098 md = find_device(param);
1099 if (!md)
1100 return -ENXIO;
1101
1102 __dev_status(md, param);
1103 dm_put(md);
1104
1105 return 0;
1106 }
1107
1108 /*
1109 * Build up the status struct for each target
1110 */
1111 static void retrieve_status(struct dm_table *table,
1112 struct dm_ioctl *param, size_t param_size)
1113 {
1114 unsigned int i, num_targets;
1115 struct dm_target_spec *spec;
1116 char *outbuf, *outptr;
1117 status_type_t type;
1118 size_t remaining, len, used = 0;
1119 unsigned status_flags = 0;
1120
1121 outptr = outbuf = get_result_buffer(param, param_size, &len);
1122
1123 if (param->flags & DM_STATUS_TABLE_FLAG)
1124 type = STATUSTYPE_TABLE;
1125 else
1126 type = STATUSTYPE_INFO;
1127
1128 /* Get all the target info */
1129 num_targets = dm_table_get_num_targets(table);
1130 for (i = 0; i < num_targets; i++) {
1131 struct dm_target *ti = dm_table_get_target(table, i);
1132 size_t l;
1133
1134 remaining = len - (outptr - outbuf);
1135 if (remaining <= sizeof(struct dm_target_spec)) {
1136 param->flags |= DM_BUFFER_FULL_FLAG;
1137 break;
1138 }
1139
1140 spec = (struct dm_target_spec *) outptr;
1141
1142 spec->status = 0;
1143 spec->sector_start = ti->begin;
1144 spec->length = ti->len;
1145 strncpy(spec->target_type, ti->type->name,
1146 sizeof(spec->target_type));
1147
1148 outptr += sizeof(struct dm_target_spec);
1149 remaining = len - (outptr - outbuf);
1150 if (remaining <= 0) {
1151 param->flags |= DM_BUFFER_FULL_FLAG;
1152 break;
1153 }
1154
1155 /* Get the status/table string from the target driver */
1156 if (ti->type->status) {
1157 if (param->flags & DM_NOFLUSH_FLAG)
1158 status_flags |= DM_STATUS_NOFLUSH_FLAG;
1159 ti->type->status(ti, type, status_flags, outptr, remaining);
1160 } else
1161 outptr[0] = '\0';
1162
1163 l = strlen(outptr) + 1;
1164 if (l == remaining) {
1165 param->flags |= DM_BUFFER_FULL_FLAG;
1166 break;
1167 }
1168
1169 outptr += l;
1170 used = param->data_start + (outptr - outbuf);
1171
1172 outptr = align_ptr(outptr);
1173 spec->next = outptr - outbuf;
1174 }
1175
1176 if (used)
1177 param->data_size = used;
1178
1179 param->target_count = num_targets;
1180 }
1181
1182 /*
1183 * Wait for a device to report an event
1184 */
1185 static int dev_wait(struct file *filp, struct dm_ioctl *param, size_t param_size)
1186 {
1187 int r = 0;
1188 struct mapped_device *md;
1189 struct dm_table *table;
1190 int srcu_idx;
1191
1192 md = find_device(param);
1193 if (!md)
1194 return -ENXIO;
1195
1196 /*
1197 * Wait for a notification event
1198 */
1199 if (dm_wait_event(md, param->event_nr)) {
1200 r = -ERESTARTSYS;
1201 goto out;
1202 }
1203
1204 /*
1205 * The userland program is going to want to know what
1206 * changed to trigger the event, so we may as well tell
1207 * him and save an ioctl.
1208 */
1209 __dev_status(md, param);
1210
1211 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1212 if (table)
1213 retrieve_status(table, param, param_size);
1214 dm_put_live_table(md, srcu_idx);
1215
1216 out:
1217 dm_put(md);
1218
1219 return r;
1220 }
1221
1222 /*
1223 * Remember the global event number and make it possible to poll
1224 * for further events.
1225 */
1226 static int dev_arm_poll(struct file *filp, struct dm_ioctl *param, size_t param_size)
1227 {
1228 struct dm_file *priv = filp->private_data;
1229
1230 priv->global_event_nr = atomic_read(&dm_global_event_nr);
1231
1232 return 0;
1233 }
1234
1235 static inline fmode_t get_mode(struct dm_ioctl *param)
1236 {
1237 fmode_t mode = FMODE_READ | FMODE_WRITE;
1238
1239 if (param->flags & DM_READONLY_FLAG)
1240 mode = FMODE_READ;
1241
1242 return mode;
1243 }
1244
1245 static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
1246 struct dm_target_spec **spec, char **target_params)
1247 {
1248 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1249 *target_params = (char *) (*spec + 1);
1250
1251 if (*spec < (last + 1))
1252 return -EINVAL;
1253
1254 return invalid_str(*target_params, end);
1255 }
1256
1257 static int populate_table(struct dm_table *table,
1258 struct dm_ioctl *param, size_t param_size)
1259 {
1260 int r;
1261 unsigned int i = 0;
1262 struct dm_target_spec *spec = (struct dm_target_spec *) param;
1263 uint32_t next = param->data_start;
1264 void *end = (void *) param + param_size;
1265 char *target_params;
1266
1267 if (!param->target_count) {
1268 DMWARN("populate_table: no targets specified");
1269 return -EINVAL;
1270 }
1271
1272 for (i = 0; i < param->target_count; i++) {
1273
1274 r = next_target(spec, next, end, &spec, &target_params);
1275 if (r) {
1276 DMWARN("unable to find target");
1277 return r;
1278 }
1279
1280 r = dm_table_add_target(table, spec->target_type,
1281 (sector_t) spec->sector_start,
1282 (sector_t) spec->length,
1283 target_params);
1284 if (r) {
1285 DMWARN("error adding target to table");
1286 return r;
1287 }
1288
1289 next = spec->next;
1290 }
1291
1292 return dm_table_complete(table);
1293 }
1294
1295 static bool is_valid_type(enum dm_queue_mode cur, enum dm_queue_mode new)
1296 {
1297 if (cur == new ||
1298 (cur == DM_TYPE_BIO_BASED && new == DM_TYPE_DAX_BIO_BASED))
1299 return true;
1300
1301 return false;
1302 }
1303
1304 static int table_load(struct file *filp, struct dm_ioctl *param, size_t param_size)
1305 {
1306 int r;
1307 struct hash_cell *hc;
1308 struct dm_table *t, *old_map = NULL;
1309 struct mapped_device *md;
1310 struct target_type *immutable_target_type;
1311
1312 md = find_device(param);
1313 if (!md)
1314 return -ENXIO;
1315
1316 r = dm_table_create(&t, get_mode(param), param->target_count, md);
1317 if (r)
1318 goto err;
1319
1320 /* Protect md->type and md->queue against concurrent table loads. */
1321 dm_lock_md_type(md);
1322 r = populate_table(t, param, param_size);
1323 if (r)
1324 goto err_unlock_md_type;
1325
1326 immutable_target_type = dm_get_immutable_target_type(md);
1327 if (immutable_target_type &&
1328 (immutable_target_type != dm_table_get_immutable_target_type(t)) &&
1329 !dm_table_get_wildcard_target(t)) {
1330 DMWARN("can't replace immutable target type %s",
1331 immutable_target_type->name);
1332 r = -EINVAL;
1333 goto err_unlock_md_type;
1334 }
1335
1336 if (dm_get_md_type(md) == DM_TYPE_NONE) {
1337 /* Initial table load: acquire type of table. */
1338 dm_set_md_type(md, dm_table_get_type(t));
1339
1340 /* setup md->queue to reflect md's type (may block) */
1341 r = dm_setup_md_queue(md, t);
1342 if (r) {
1343 DMWARN("unable to set up device queue for new table.");
1344 goto err_unlock_md_type;
1345 }
1346 } else if (!is_valid_type(dm_get_md_type(md), dm_table_get_type(t))) {
1347 DMWARN("can't change device type (old=%u vs new=%u) after initial table load.",
1348 dm_get_md_type(md), dm_table_get_type(t));
1349 r = -EINVAL;
1350 goto err_unlock_md_type;
1351 }
1352
1353 dm_unlock_md_type(md);
1354
1355 /* stage inactive table */
1356 down_write(&_hash_lock);
1357 hc = dm_get_mdptr(md);
1358 if (!hc || hc->md != md) {
1359 DMWARN("device has been removed from the dev hash table.");
1360 up_write(&_hash_lock);
1361 r = -ENXIO;
1362 goto err_destroy_table;
1363 }
1364
1365 if (hc->new_map)
1366 old_map = hc->new_map;
1367 hc->new_map = t;
1368 up_write(&_hash_lock);
1369
1370 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1371 __dev_status(md, param);
1372
1373 if (old_map) {
1374 dm_sync_table(md);
1375 dm_table_destroy(old_map);
1376 }
1377
1378 dm_put(md);
1379
1380 return 0;
1381
1382 err_unlock_md_type:
1383 dm_unlock_md_type(md);
1384 err_destroy_table:
1385 dm_table_destroy(t);
1386 err:
1387 dm_put(md);
1388
1389 return r;
1390 }
1391
1392 static int table_clear(struct file *filp, struct dm_ioctl *param, size_t param_size)
1393 {
1394 struct hash_cell *hc;
1395 struct mapped_device *md;
1396 struct dm_table *old_map = NULL;
1397
1398 down_write(&_hash_lock);
1399
1400 hc = __find_device_hash_cell(param);
1401 if (!hc) {
1402 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1403 up_write(&_hash_lock);
1404 return -ENXIO;
1405 }
1406
1407 if (hc->new_map) {
1408 old_map = hc->new_map;
1409 hc->new_map = NULL;
1410 }
1411
1412 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1413
1414 __dev_status(hc->md, param);
1415 md = hc->md;
1416 up_write(&_hash_lock);
1417 if (old_map) {
1418 dm_sync_table(md);
1419 dm_table_destroy(old_map);
1420 }
1421 dm_put(md);
1422
1423 return 0;
1424 }
1425
1426 /*
1427 * Retrieves a list of devices used by a particular dm device.
1428 */
1429 static void retrieve_deps(struct dm_table *table,
1430 struct dm_ioctl *param, size_t param_size)
1431 {
1432 unsigned int count = 0;
1433 struct list_head *tmp;
1434 size_t len, needed;
1435 struct dm_dev_internal *dd;
1436 struct dm_target_deps *deps;
1437
1438 deps = get_result_buffer(param, param_size, &len);
1439
1440 /*
1441 * Count the devices.
1442 */
1443 list_for_each (tmp, dm_table_get_devices(table))
1444 count++;
1445
1446 /*
1447 * Check we have enough space.
1448 */
1449 needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
1450 if (len < needed) {
1451 param->flags |= DM_BUFFER_FULL_FLAG;
1452 return;
1453 }
1454
1455 /*
1456 * Fill in the devices.
1457 */
1458 deps->count = count;
1459 count = 0;
1460 list_for_each_entry (dd, dm_table_get_devices(table), list)
1461 deps->dev[count++] = huge_encode_dev(dd->dm_dev->bdev->bd_dev);
1462
1463 param->data_size = param->data_start + needed;
1464 }
1465
1466 static int table_deps(struct file *filp, struct dm_ioctl *param, size_t param_size)
1467 {
1468 struct mapped_device *md;
1469 struct dm_table *table;
1470 int srcu_idx;
1471
1472 md = find_device(param);
1473 if (!md)
1474 return -ENXIO;
1475
1476 __dev_status(md, param);
1477
1478 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1479 if (table)
1480 retrieve_deps(table, param, param_size);
1481 dm_put_live_table(md, srcu_idx);
1482
1483 dm_put(md);
1484
1485 return 0;
1486 }
1487
1488 /*
1489 * Return the status of a device as a text string for each
1490 * target.
1491 */
1492 static int table_status(struct file *filp, struct dm_ioctl *param, size_t param_size)
1493 {
1494 struct mapped_device *md;
1495 struct dm_table *table;
1496 int srcu_idx;
1497
1498 md = find_device(param);
1499 if (!md)
1500 return -ENXIO;
1501
1502 __dev_status(md, param);
1503
1504 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1505 if (table)
1506 retrieve_status(table, param, param_size);
1507 dm_put_live_table(md, srcu_idx);
1508
1509 dm_put(md);
1510
1511 return 0;
1512 }
1513
1514 /*
1515 * Process device-mapper dependent messages. Messages prefixed with '@'
1516 * are processed by the DM core. All others are delivered to the target.
1517 * Returns a number <= 1 if message was processed by device mapper.
1518 * Returns 2 if message should be delivered to the target.
1519 */
1520 static int message_for_md(struct mapped_device *md, unsigned argc, char **argv,
1521 char *result, unsigned maxlen)
1522 {
1523 int r;
1524
1525 if (**argv != '@')
1526 return 2; /* no '@' prefix, deliver to target */
1527
1528 if (!strcasecmp(argv[0], "@cancel_deferred_remove")) {
1529 if (argc != 1) {
1530 DMERR("Invalid arguments for @cancel_deferred_remove");
1531 return -EINVAL;
1532 }
1533 return dm_cancel_deferred_remove(md);
1534 }
1535
1536 r = dm_stats_message(md, argc, argv, result, maxlen);
1537 if (r < 2)
1538 return r;
1539
1540 DMERR("Unsupported message sent to DM core: %s", argv[0]);
1541 return -EINVAL;
1542 }
1543
1544 /*
1545 * Pass a message to the target that's at the supplied device offset.
1546 */
1547 static int target_message(struct file *filp, struct dm_ioctl *param, size_t param_size)
1548 {
1549 int r, argc;
1550 char **argv;
1551 struct mapped_device *md;
1552 struct dm_table *table;
1553 struct dm_target *ti;
1554 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1555 size_t maxlen;
1556 char *result = get_result_buffer(param, param_size, &maxlen);
1557 int srcu_idx;
1558
1559 md = find_device(param);
1560 if (!md)
1561 return -ENXIO;
1562
1563 if (tmsg < (struct dm_target_msg *) param->data ||
1564 invalid_str(tmsg->message, (void *) param + param_size)) {
1565 DMWARN("Invalid target message parameters.");
1566 r = -EINVAL;
1567 goto out;
1568 }
1569
1570 r = dm_split_args(&argc, &argv, tmsg->message);
1571 if (r) {
1572 DMWARN("Failed to split target message parameters");
1573 goto out;
1574 }
1575
1576 if (!argc) {
1577 DMWARN("Empty message received.");
1578 goto out_argv;
1579 }
1580
1581 r = message_for_md(md, argc, argv, result, maxlen);
1582 if (r <= 1)
1583 goto out_argv;
1584
1585 table = dm_get_live_table(md, &srcu_idx);
1586 if (!table)
1587 goto out_table;
1588
1589 if (dm_deleting_md(md)) {
1590 r = -ENXIO;
1591 goto out_table;
1592 }
1593
1594 ti = dm_table_find_target(table, tmsg->sector);
1595 if (!dm_target_is_valid(ti)) {
1596 DMWARN("Target message sector outside device.");
1597 r = -EINVAL;
1598 } else if (ti->type->message)
1599 r = ti->type->message(ti, argc, argv, result, maxlen);
1600 else {
1601 DMWARN("Target type does not support messages");
1602 r = -EINVAL;
1603 }
1604
1605 out_table:
1606 dm_put_live_table(md, srcu_idx);
1607 out_argv:
1608 kfree(argv);
1609 out:
1610 if (r >= 0)
1611 __dev_status(md, param);
1612
1613 if (r == 1) {
1614 param->flags |= DM_DATA_OUT_FLAG;
1615 if (dm_message_test_buffer_overflow(result, maxlen))
1616 param->flags |= DM_BUFFER_FULL_FLAG;
1617 else
1618 param->data_size = param->data_start + strlen(result) + 1;
1619 r = 0;
1620 }
1621
1622 dm_put(md);
1623 return r;
1624 }
1625
1626 /*
1627 * The ioctl parameter block consists of two parts, a dm_ioctl struct
1628 * followed by a data buffer. This flag is set if the second part,
1629 * which has a variable size, is not used by the function processing
1630 * the ioctl.
1631 */
1632 #define IOCTL_FLAGS_NO_PARAMS 1
1633 #define IOCTL_FLAGS_ISSUE_GLOBAL_EVENT 2
1634
1635 /*-----------------------------------------------------------------
1636 * Implementation of open/close/ioctl on the special char
1637 * device.
1638 *---------------------------------------------------------------*/
1639 static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags)
1640 {
1641 static const struct {
1642 int cmd;
1643 int flags;
1644 ioctl_fn fn;
1645 } _ioctls[] = {
1646 {DM_VERSION_CMD, 0, NULL}, /* version is dealt with elsewhere */
1647 {DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, remove_all},
1648 {DM_LIST_DEVICES_CMD, 0, list_devices},
1649
1650 {DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_create},
1651 {DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_remove},
1652 {DM_DEV_RENAME_CMD, IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_rename},
1653 {DM_DEV_SUSPEND_CMD, IOCTL_FLAGS_NO_PARAMS, dev_suspend},
1654 {DM_DEV_STATUS_CMD, IOCTL_FLAGS_NO_PARAMS, dev_status},
1655 {DM_DEV_WAIT_CMD, 0, dev_wait},
1656
1657 {DM_TABLE_LOAD_CMD, 0, table_load},
1658 {DM_TABLE_CLEAR_CMD, IOCTL_FLAGS_NO_PARAMS, table_clear},
1659 {DM_TABLE_DEPS_CMD, 0, table_deps},
1660 {DM_TABLE_STATUS_CMD, 0, table_status},
1661
1662 {DM_LIST_VERSIONS_CMD, 0, list_versions},
1663
1664 {DM_TARGET_MSG_CMD, 0, target_message},
1665 {DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry},
1666 {DM_DEV_ARM_POLL, IOCTL_FLAGS_NO_PARAMS, dev_arm_poll},
1667 };
1668
1669 if (unlikely(cmd >= ARRAY_SIZE(_ioctls)))
1670 return NULL;
1671
1672 *ioctl_flags = _ioctls[cmd].flags;
1673 return _ioctls[cmd].fn;
1674 }
1675
1676 /*
1677 * As well as checking the version compatibility this always
1678 * copies the kernel interface version out.
1679 */
1680 static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1681 {
1682 uint32_t version[3];
1683 int r = 0;
1684
1685 if (copy_from_user(version, user->version, sizeof(version)))
1686 return -EFAULT;
1687
1688 if ((DM_VERSION_MAJOR != version[0]) ||
1689 (DM_VERSION_MINOR < version[1])) {
1690 DMWARN("ioctl interface mismatch: "
1691 "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1692 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1693 DM_VERSION_PATCHLEVEL,
1694 version[0], version[1], version[2], cmd);
1695 r = -EINVAL;
1696 }
1697
1698 /*
1699 * Fill in the kernel version.
1700 */
1701 version[0] = DM_VERSION_MAJOR;
1702 version[1] = DM_VERSION_MINOR;
1703 version[2] = DM_VERSION_PATCHLEVEL;
1704 if (copy_to_user(user->version, version, sizeof(version)))
1705 return -EFAULT;
1706
1707 return r;
1708 }
1709
1710 #define DM_PARAMS_MALLOC 0x0001 /* Params allocated with kvmalloc() */
1711 #define DM_WIPE_BUFFER 0x0010 /* Wipe input buffer before returning from ioctl */
1712
1713 static void free_params(struct dm_ioctl *param, size_t param_size, int param_flags)
1714 {
1715 if (param_flags & DM_WIPE_BUFFER)
1716 memset(param, 0, param_size);
1717
1718 if (param_flags & DM_PARAMS_MALLOC)
1719 kvfree(param);
1720 }
1721
1722 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel,
1723 int ioctl_flags,
1724 struct dm_ioctl **param, int *param_flags)
1725 {
1726 struct dm_ioctl *dmi;
1727 int secure_data;
1728 const size_t minimum_data_size = offsetof(struct dm_ioctl, data);
1729 unsigned noio_flag;
1730
1731 if (copy_from_user(param_kernel, user, minimum_data_size))
1732 return -EFAULT;
1733
1734 if (param_kernel->data_size < minimum_data_size)
1735 return -EINVAL;
1736
1737 secure_data = param_kernel->flags & DM_SECURE_DATA_FLAG;
1738
1739 *param_flags = secure_data ? DM_WIPE_BUFFER : 0;
1740
1741 if (ioctl_flags & IOCTL_FLAGS_NO_PARAMS) {
1742 dmi = param_kernel;
1743 dmi->data_size = minimum_data_size;
1744 goto data_copied;
1745 }
1746
1747 /*
1748 * Use __GFP_HIGH to avoid low memory issues when a device is
1749 * suspended and the ioctl is needed to resume it.
1750 * Use kmalloc() rather than vmalloc() when we can.
1751 */
1752 dmi = NULL;
1753 noio_flag = memalloc_noio_save();
1754 dmi = kvmalloc(param_kernel->data_size, GFP_KERNEL | __GFP_HIGH);
1755 memalloc_noio_restore(noio_flag);
1756
1757 if (!dmi) {
1758 if (secure_data && clear_user(user, param_kernel->data_size))
1759 return -EFAULT;
1760 return -ENOMEM;
1761 }
1762
1763 *param_flags |= DM_PARAMS_MALLOC;
1764
1765 if (copy_from_user(dmi, user, param_kernel->data_size))
1766 goto bad;
1767
1768 data_copied:
1769 /*
1770 * Abort if something changed the ioctl data while it was being copied.
1771 */
1772 if (dmi->data_size != param_kernel->data_size) {
1773 DMERR("rejecting ioctl: data size modified while processing parameters");
1774 goto bad;
1775 }
1776
1777 /* Wipe the user buffer so we do not return it to userspace */
1778 if (secure_data && clear_user(user, param_kernel->data_size))
1779 goto bad;
1780
1781 *param = dmi;
1782 return 0;
1783
1784 bad:
1785 free_params(dmi, param_kernel->data_size, *param_flags);
1786
1787 return -EFAULT;
1788 }
1789
1790 static int validate_params(uint cmd, struct dm_ioctl *param)
1791 {
1792 /* Always clear this flag */
1793 param->flags &= ~DM_BUFFER_FULL_FLAG;
1794 param->flags &= ~DM_UEVENT_GENERATED_FLAG;
1795 param->flags &= ~DM_SECURE_DATA_FLAG;
1796 param->flags &= ~DM_DATA_OUT_FLAG;
1797
1798 /* Ignores parameters */
1799 if (cmd == DM_REMOVE_ALL_CMD ||
1800 cmd == DM_LIST_DEVICES_CMD ||
1801 cmd == DM_LIST_VERSIONS_CMD)
1802 return 0;
1803
1804 if (cmd == DM_DEV_CREATE_CMD) {
1805 if (!*param->name) {
1806 DMWARN("name not supplied when creating device");
1807 return -EINVAL;
1808 }
1809 } else if (*param->uuid && *param->name) {
1810 DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
1811 return -EINVAL;
1812 }
1813
1814 /* Ensure strings are terminated */
1815 param->name[DM_NAME_LEN - 1] = '\0';
1816 param->uuid[DM_UUID_LEN - 1] = '\0';
1817
1818 return 0;
1819 }
1820
1821 static int ctl_ioctl(struct file *file, uint command, struct dm_ioctl __user *user)
1822 {
1823 int r = 0;
1824 int ioctl_flags;
1825 int param_flags;
1826 unsigned int cmd;
1827 struct dm_ioctl *uninitialized_var(param);
1828 ioctl_fn fn = NULL;
1829 size_t input_param_size;
1830 struct dm_ioctl param_kernel;
1831
1832 /* only root can play with this */
1833 if (!capable(CAP_SYS_ADMIN))
1834 return -EACCES;
1835
1836 if (_IOC_TYPE(command) != DM_IOCTL)
1837 return -ENOTTY;
1838
1839 cmd = _IOC_NR(command);
1840
1841 /*
1842 * Check the interface version passed in. This also
1843 * writes out the kernel's interface version.
1844 */
1845 r = check_version(cmd, user);
1846 if (r)
1847 return r;
1848
1849 /*
1850 * Nothing more to do for the version command.
1851 */
1852 if (cmd == DM_VERSION_CMD)
1853 return 0;
1854
1855 fn = lookup_ioctl(cmd, &ioctl_flags);
1856 if (!fn) {
1857 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1858 return -ENOTTY;
1859 }
1860
1861 /*
1862 * Copy the parameters into kernel space.
1863 */
1864 r = copy_params(user, &param_kernel, ioctl_flags, &param, &param_flags);
1865
1866 if (r)
1867 return r;
1868
1869 input_param_size = param->data_size;
1870 r = validate_params(cmd, param);
1871 if (r)
1872 goto out;
1873
1874 param->data_size = offsetof(struct dm_ioctl, data);
1875 r = fn(file, param, input_param_size);
1876
1877 if (unlikely(param->flags & DM_BUFFER_FULL_FLAG) &&
1878 unlikely(ioctl_flags & IOCTL_FLAGS_NO_PARAMS))
1879 DMERR("ioctl %d tried to output some data but has IOCTL_FLAGS_NO_PARAMS set", cmd);
1880
1881 if (!r && ioctl_flags & IOCTL_FLAGS_ISSUE_GLOBAL_EVENT)
1882 dm_issue_global_event();
1883
1884 /*
1885 * Copy the results back to userland.
1886 */
1887 if (!r && copy_to_user(user, param, param->data_size))
1888 r = -EFAULT;
1889
1890 out:
1891 free_params(param, input_param_size, param_flags);
1892 return r;
1893 }
1894
1895 static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
1896 {
1897 return (long)ctl_ioctl(file, command, (struct dm_ioctl __user *)u);
1898 }
1899
1900 #ifdef CONFIG_COMPAT
1901 static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
1902 {
1903 return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
1904 }
1905 #else
1906 #define dm_compat_ctl_ioctl NULL
1907 #endif
1908
1909 static int dm_open(struct inode *inode, struct file *filp)
1910 {
1911 int r;
1912 struct dm_file *priv;
1913
1914 r = nonseekable_open(inode, filp);
1915 if (unlikely(r))
1916 return r;
1917
1918 priv = filp->private_data = kmalloc(sizeof(struct dm_file), GFP_KERNEL);
1919 if (!priv)
1920 return -ENOMEM;
1921
1922 priv->global_event_nr = atomic_read(&dm_global_event_nr);
1923
1924 return 0;
1925 }
1926
1927 static int dm_release(struct inode *inode, struct file *filp)
1928 {
1929 kfree(filp->private_data);
1930 return 0;
1931 }
1932
1933 static __poll_t dm_poll(struct file *filp, poll_table *wait)
1934 {
1935 struct dm_file *priv = filp->private_data;
1936 __poll_t mask = 0;
1937
1938 poll_wait(filp, &dm_global_eventq, wait);
1939
1940 if ((int)(atomic_read(&dm_global_event_nr) - priv->global_event_nr) > 0)
1941 mask |= EPOLLIN;
1942
1943 return mask;
1944 }
1945
1946 static const struct file_operations _ctl_fops = {
1947 .open = dm_open,
1948 .release = dm_release,
1949 .poll = dm_poll,
1950 .unlocked_ioctl = dm_ctl_ioctl,
1951 .compat_ioctl = dm_compat_ctl_ioctl,
1952 .owner = THIS_MODULE,
1953 .llseek = noop_llseek,
1954 };
1955
1956 static struct miscdevice _dm_misc = {
1957 .minor = MAPPER_CTRL_MINOR,
1958 .name = DM_NAME,
1959 .nodename = DM_DIR "/" DM_CONTROL_NODE,
1960 .fops = &_ctl_fops
1961 };
1962
1963 MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
1964 MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
1965
1966 /*
1967 * Create misc character device and link to DM_DIR/control.
1968 */
1969 int __init dm_interface_init(void)
1970 {
1971 int r;
1972
1973 r = dm_hash_init();
1974 if (r)
1975 return r;
1976
1977 r = misc_register(&_dm_misc);
1978 if (r) {
1979 DMERR("misc_register failed for control device");
1980 dm_hash_exit();
1981 return r;
1982 }
1983
1984 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
1985 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
1986 DM_DRIVER_EMAIL);
1987 return 0;
1988 }
1989
1990 void dm_interface_exit(void)
1991 {
1992 misc_deregister(&_dm_misc);
1993 dm_hash_exit();
1994 }
1995
1996 /**
1997 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
1998 * @md: Pointer to mapped_device
1999 * @name: Buffer (size DM_NAME_LEN) for name
2000 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
2001 */
2002 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
2003 {
2004 int r = 0;
2005 struct hash_cell *hc;
2006
2007 if (!md)
2008 return -ENXIO;
2009
2010 mutex_lock(&dm_hash_cells_mutex);
2011 hc = dm_get_mdptr(md);
2012 if (!hc || hc->md != md) {
2013 r = -ENXIO;
2014 goto out;
2015 }
2016
2017 if (name)
2018 strcpy(name, hc->name);
2019 if (uuid)
2020 strcpy(uuid, hc->uuid ? : "");
2021
2022 out:
2023 mutex_unlock(&dm_hash_cells_mutex);
2024
2025 return r;
2026 }
Linux with added FPC-III support