projects/linux·blob master · refs

2472 lines · 56.1 KiB

1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
4 * Copyright (C) 2004 - 2006 Red Hat, Inc. All rights reserved.
5 *
6 * This file is released under the GPL.
7 */
8
9#include "dm-core.h"
10#include "dm-ima.h"
11#include <linux/module.h>
12#include <linux/vmalloc.h>
13#include <linux/miscdevice.h>
14#include <linux/sched/mm.h>
15#include <linux/init.h>
16#include <linux/wait.h>
17#include <linux/slab.h>
18#include <linux/rbtree.h>
19#include <linux/dm-ioctl.h>
20#include <linux/hdreg.h>
21#include <linux/compat.h>
22#include <linux/nospec.h>
23
24#include <linux/uaccess.h>
25#include <linux/ima.h>
26
27#define DM_MSG_PREFIX "ioctl"
28#define DM_DRIVER_EMAIL "[email protected]"
29
30struct dm_file {
31 /*
32 * poll will wait until the global event number is greater than
33 * this value.
34 */
35 volatile unsigned int global_event_nr;
36};
37
38/*
39 *---------------------------------------------------------------
40 * The ioctl interface needs to be able to look up devices by
41 * name or uuid.
42 *---------------------------------------------------------------
43 */
44struct hash_cell {
45 struct rb_node name_node;
46 struct rb_node uuid_node;
47 bool name_set;
48 bool uuid_set;
49
50 char *name;
51 char *uuid;
52 struct mapped_device *md;
53 struct dm_table *new_map;
54};
55
56struct vers_iter {
57 struct dm_target_versions *vers, *old_vers;
58 char *end;
59};
60
61
62static struct rb_root name_rb_tree = RB_ROOT;
63static struct rb_root uuid_rb_tree = RB_ROOT;
64
65#define DM_REMOVE_KEEP_OPEN_DEVICES 1
66#define DM_REMOVE_MARK_DEFERRED 2
67#define DM_REMOVE_ONLY_DEFERRED 4
68#define DM_REMOVE_INTERRUPTIBLE 8
69static int dm_hash_remove_all(unsigned flags);
70
71/*
72 * Guards access to both hash tables.
73 */
74static DECLARE_RWSEM(_hash_lock);
75
76/*
77 * Protects use of mdptr to obtain hash cell name and uuid from mapped device.
78 */
79static DEFINE_MUTEX(dm_hash_cells_mutex);
80
81static void dm_hash_exit(void)
82{
83 dm_hash_remove_all(0);
84}
85
86/*
87 *---------------------------------------------------------------
88 * Code for looking up a device by name
89 *---------------------------------------------------------------
90 */
91static struct hash_cell *__get_name_cell(const char *str)
92{
93 struct rb_node *n = name_rb_tree.rb_node;
94
95 while (n) {
96 struct hash_cell *hc = container_of(n, struct hash_cell, name_node);
97 int c;
98
99 c = strcmp(hc->name, str);
100 if (!c) {
101 dm_get(hc->md);
102 return hc;
103 }
104 n = c >= 0 ? n->rb_left : n->rb_right;
105 }
106
107 return NULL;
108}
109
110static struct hash_cell *__get_uuid_cell(const char *str)
111{
112 struct rb_node *n = uuid_rb_tree.rb_node;
113
114 while (n) {
115 struct hash_cell *hc = container_of(n, struct hash_cell, uuid_node);
116 int c;
117
118 c = strcmp(hc->uuid, str);
119 if (!c) {
120 dm_get(hc->md);
121 return hc;
122 }
123 n = c >= 0 ? n->rb_left : n->rb_right;
124 }
125
126 return NULL;
127}
128
129static void __unlink_name(struct hash_cell *hc)
130{
131 if (hc->name_set) {
132 hc->name_set = false;
133 rb_erase(&hc->name_node, &name_rb_tree);
134 }
135}
136
137static void __unlink_uuid(struct hash_cell *hc)
138{
139 if (hc->uuid_set) {
140 hc->uuid_set = false;
141 rb_erase(&hc->uuid_node, &uuid_rb_tree);
142 }
143}
144
145static void __link_name(struct hash_cell *new_hc)
146{
147 struct rb_node **n, *parent;
148
149 __unlink_name(new_hc);
150
151 new_hc->name_set = true;
152
153 n = &name_rb_tree.rb_node;
154 parent = NULL;
155
156 while (*n) {
157 struct hash_cell *hc = container_of(*n, struct hash_cell, name_node);
158 int c;
159
160 c = strcmp(hc->name, new_hc->name);
161 BUG_ON(!c);
162 parent = *n;
163 n = c >= 0 ? &hc->name_node.rb_left : &hc->name_node.rb_right;
164 }
165
166 rb_link_node(&new_hc->name_node, parent, n);
167 rb_insert_color(&new_hc->name_node, &name_rb_tree);
168}
169
170static void __link_uuid(struct hash_cell *new_hc)
171{
172 struct rb_node **n, *parent;
173
174 __unlink_uuid(new_hc);
175
176 new_hc->uuid_set = true;
177
178 n = &uuid_rb_tree.rb_node;
179 parent = NULL;
180
181 while (*n) {
182 struct hash_cell *hc = container_of(*n, struct hash_cell, uuid_node);
183 int c;
184
185 c = strcmp(hc->uuid, new_hc->uuid);
186 BUG_ON(!c);
187 parent = *n;
188 n = c > 0 ? &hc->uuid_node.rb_left : &hc->uuid_node.rb_right;
189 }
190
191 rb_link_node(&new_hc->uuid_node, parent, n);
192 rb_insert_color(&new_hc->uuid_node, &uuid_rb_tree);
193}
194
195static struct hash_cell *__get_dev_cell(uint64_t dev)
196{
197 struct mapped_device *md;
198 struct hash_cell *hc;
199
200 md = dm_get_md(huge_decode_dev(dev));
201 if (!md)
202 return NULL;
203
204 hc = dm_get_mdptr(md);
205 if (!hc) {
206 dm_put(md);
207 return NULL;
208 }
209
210 return hc;
211}
212
213/*
214 *---------------------------------------------------------------
215 * Inserting, removing and renaming a device.
216 *---------------------------------------------------------------
217 */
218static struct hash_cell *alloc_cell(const char *name, const char *uuid,
219 struct mapped_device *md)
220{
221 struct hash_cell *hc;
222
223 hc = kmalloc_obj(*hc);
224 if (!hc)
225 return NULL;
226
227 hc->name = kstrdup(name, GFP_KERNEL);
228 if (!hc->name) {
229 kfree(hc);
230 return NULL;
231 }
232
233 if (!uuid)
234 hc->uuid = NULL;
235
236 else {
237 hc->uuid = kstrdup(uuid, GFP_KERNEL);
238 if (!hc->uuid) {
239 kfree(hc->name);
240 kfree(hc);
241 return NULL;
242 }
243 }
244
245 hc->name_set = hc->uuid_set = false;
246 hc->md = md;
247 hc->new_map = NULL;
248 return hc;
249}
250
251static void free_cell(struct hash_cell *hc)
252{
253 if (hc) {
254 kfree(hc->name);
255 kfree(hc->uuid);
256 kfree(hc);
257 }
258}
259
260#ifdef CONFIG_IMA
261
262/*
263 * Called while holding to _hash_lock, to guarantee the ordering of the
264 * following dm_ima_measure_on_* functions, which should be called
265 * right after dropping the _hash_lock
266 */
267static unsigned int dm_ima_init_context(struct hash_cell *hc,
268 struct dm_ima_context *context,
269 bool need_idx)
270{
271 lockdep_assert_held(&_hash_lock);
272
273 if (unlikely(!context))
274 return need_idx ? hc->md->ima.update_idx++ : 0;
275
276 context->update_idx = hc->md->ima.update_idx++;
277 strcpy(context->dev_name, hc->name);
278 strcpy(context->dev_uuid, hc->uuid ? : "");
279
280 return context->update_idx;
281}
282
283/*
284 * Called by do_resume() to guarantee correct ordering, since do_resume()
285 * does not grab the _hash_lock when the table is not getting swapped or
286 * when actually swapping the active table
287 */
288static bool dm_ima_need_measure(struct mapped_device *md,
289 struct dm_table *table,
290 struct dm_ima_context *context)
291{
292 int srcu_idx;
293 struct hash_cell *hc;
294 bool need_measure = false;
295
296 if (unlikely(!context))
297 return false;
298
299 down_write(&_hash_lock);
300 /* Check if the device has been removed */
301 hc = dm_get_mdptr(md);
302 if (hc) {
303 /*
304 * If we have a table, we need to make sure that it's the
305 * active table. Otherwise we raced with another process
306 * setting the active table and it will do the measurement
307 */
308 if (!table || dm_get_live_table(md, &srcu_idx) == table) {
309 dm_ima_init_context(hc, context, false);
310 need_measure = true;
311 }
312 if (table)
313 dm_put_live_table(md, srcu_idx);
314 }
315 up_write(&_hash_lock);
316
317 return need_measure;
318}
319#else
320static inline unsigned int dm_ima_init_context(struct hash_cell *hc,
321 struct dm_ima_context *context,
322 bool neex_idx)
323{
324 return 0;
325}
326static inline bool dm_ima_need_measure(struct mapped_device *md,
327 struct dm_table *table,
328 struct dm_ima_context *context)
329{
330 return false;
331}
332#endif
333
334/*
335 * The kdev_t and uuid of a device can never change once it is
336 * initially inserted.
337 */
338static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
339{
340 struct hash_cell *cell, *hc;
341
342 /*
343 * Allocate the new cells.
344 */
345 cell = alloc_cell(name, uuid, md);
346 if (!cell)
347 return -ENOMEM;
348
349 /*
350 * Insert the cell into both hash tables.
351 */
352 down_write(&_hash_lock);
353 hc = __get_name_cell(name);
354 if (hc) {
355 dm_put(hc->md);
356 goto bad;
357 }
358
359 __link_name(cell);
360
361 if (uuid) {
362 hc = __get_uuid_cell(uuid);
363 if (hc) {
364 __unlink_name(cell);
365 dm_put(hc->md);
366 goto bad;
367 }
368 __link_uuid(cell);
369 }
370 dm_get(md);
371 mutex_lock(&dm_hash_cells_mutex);
372 dm_set_mdptr(md, cell);
373 mutex_unlock(&dm_hash_cells_mutex);
374 up_write(&_hash_lock);
375
376 return 0;
377
378 bad:
379 up_write(&_hash_lock);
380 free_cell(cell);
381 return -EBUSY;
382}
383
384static struct dm_table *__hash_remove(struct hash_cell *hc)
385{
386 struct dm_table *table;
387 int srcu_idx;
388
389 lockdep_assert_held(&_hash_lock);
390
391 /* remove from the dev trees */
392 __unlink_name(hc);
393 __unlink_uuid(hc);
394 mutex_lock(&dm_hash_cells_mutex);
395 dm_set_mdptr(hc->md, NULL);
396 mutex_unlock(&dm_hash_cells_mutex);
397
398 table = dm_get_live_table(hc->md, &srcu_idx);
399 if (table)
400 dm_table_event(table);
401 dm_put_live_table(hc->md, srcu_idx);
402
403 table = NULL;
404 if (hc->new_map)
405 table = hc->new_map;
406 dm_put(hc->md);
407 free_cell(hc);
408
409 return table;
410}
411
412static int dm_hash_remove_all(unsigned flags)
413{
414 int dev_skipped;
415 struct rb_node *n;
416 struct hash_cell *hc;
417 struct mapped_device *md;
418 struct dm_table *t;
419 struct dm_ima_context *ima_context = NULL;
420 unsigned int ima_idx;
421
422 dm_ima_alloc_context(&ima_context, true);
423retry:
424 dev_skipped = 0;
425
426 down_write(&_hash_lock);
427
428 for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {
429 if (flags & DM_REMOVE_INTERRUPTIBLE && fatal_signal_pending(current)) {
430 up_write(&_hash_lock);
431 dm_ima_free_context(ima_context);
432 return -EINTR;
433 }
434
435 hc = container_of(n, struct hash_cell, name_node);
436 md = hc->md;
437 dm_get(md);
438
439 if (flags & DM_REMOVE_KEEP_OPEN_DEVICES &&
440 dm_lock_for_deletion(md, !!(flags & DM_REMOVE_MARK_DEFERRED), !!(flags & DM_REMOVE_ONLY_DEFERRED))) {
441 dm_put(md);
442 dev_skipped++;
443 continue;
444 }
445
446 ima_idx = dm_ima_init_context(hc, ima_context, true);
447 t = __hash_remove(hc);
448
449 up_write(&_hash_lock);
450
451 if (t) {
452 dm_sync_table(md);
453 dm_table_destroy(t);
454 }
455 dm_ima_measure_on_device_remove(md, true, ima_context, ima_idx);
456 dm_put(md);
457 if (likely(flags & DM_REMOVE_KEEP_OPEN_DEVICES))
458 dm_destroy(md);
459 else
460 dm_destroy_immediate(md);
461
462 /*
463 * Some mapped devices may be using other mapped
464 * devices, so repeat until we make no further
465 * progress. If a new mapped device is created
466 * here it will also get removed.
467 */
468 goto retry;
469 }
470
471 up_write(&_hash_lock);
472
473 if (dev_skipped && !(flags & DM_REMOVE_ONLY_DEFERRED))
474 DMWARN("remove_all left %d open device(s)", dev_skipped);
475
476 dm_ima_free_context(ima_context);
477 return 0;
478}
479
480/*
481 * Set the uuid of a hash_cell that isn't already set.
482 */
483static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
484{
485 mutex_lock(&dm_hash_cells_mutex);
486 hc->uuid = new_uuid;
487 mutex_unlock(&dm_hash_cells_mutex);
488
489 __link_uuid(hc);
490}
491
492/*
493 * Changes the name of a hash_cell and returns the old name for
494 * the caller to free.
495 */
496static char *__change_cell_name(struct hash_cell *hc, char *new_name)
497{
498 char *old_name;
499
500 /*
501 * Rename and move the name cell.
502 */
503 __unlink_name(hc);
504 old_name = hc->name;
505
506 mutex_lock(&dm_hash_cells_mutex);
507 hc->name = new_name;
508 mutex_unlock(&dm_hash_cells_mutex);
509
510 __link_name(hc);
511
512 return old_name;
513}
514
515static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
516 const char *new)
517{
518 char *new_data, *old_name = NULL;
519 struct hash_cell *hc;
520 struct dm_table *table;
521 struct mapped_device *md;
522 unsigned int change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
523 int srcu_idx;
524 struct dm_ima_context *ima_context = NULL;
525
526 /*
527 * duplicate new.
528 */
529 new_data = kstrdup(new, GFP_KERNEL);
530 if (!new_data)
531 return ERR_PTR(-ENOMEM);
532
533 dm_ima_alloc_context(&ima_context, true);
534 down_write(&_hash_lock);
535
536 /*
537 * Is new free ?
538 */
539 if (change_uuid)
540 hc = __get_uuid_cell(new);
541 else
542 hc = __get_name_cell(new);
543
544 if (hc) {
545 DMERR("Unable to change %s on mapped device %s to one that already exists: %s",
546 change_uuid ? "uuid" : "name",
547 param->name, new);
548 dm_put(hc->md);
549 up_write(&_hash_lock);
550 dm_ima_free_context(ima_context);
551 kfree(new_data);
552 return ERR_PTR(-EBUSY);
553 }
554
555 /*
556 * Is there such a device as 'old' ?
557 */
558 hc = __get_name_cell(param->name);
559 if (!hc) {
560 DMERR("Unable to rename non-existent device, %s to %s%s",
561 param->name, change_uuid ? "uuid " : "", new);
562 up_write(&_hash_lock);
563 dm_ima_free_context(ima_context);
564 kfree(new_data);
565 return ERR_PTR(-ENXIO);
566 }
567
568 /*
569 * Does this device already have a uuid?
570 */
571 if (change_uuid && hc->uuid) {
572 DMERR("Unable to change uuid of mapped device %s to %s "
573 "because uuid is already set to %s",
574 param->name, new, hc->uuid);
575 dm_put(hc->md);
576 up_write(&_hash_lock);
577 dm_ima_free_context(ima_context);
578 kfree(new_data);
579 return ERR_PTR(-EINVAL);
580 }
581
582 if (change_uuid)
583 __set_cell_uuid(hc, new_data);
584 else
585 old_name = __change_cell_name(hc, new_data);
586
587 /*
588 * Wake up any dm event waiters.
589 */
590 table = dm_get_live_table(hc->md, &srcu_idx);
591 if (table)
592 dm_table_event(table);
593 dm_put_live_table(hc->md, srcu_idx);
594
595 if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr, false))
596 param->flags |= DM_UEVENT_GENERATED_FLAG;
597
598 md = hc->md;
599
600 dm_ima_init_context(hc, ima_context, false);
601
602 up_write(&_hash_lock);
603 dm_ima_measure_on_device_rename(md, ima_context);
604 dm_ima_free_context(ima_context);
605 kfree(old_name);
606
607 return md;
608}
609
610void dm_deferred_remove(void)
611{
612 dm_hash_remove_all(DM_REMOVE_KEEP_OPEN_DEVICES | DM_REMOVE_ONLY_DEFERRED);
613}
614
615/*
616 *---------------------------------------------------------------
617 * Implementation of the ioctl commands
618 *---------------------------------------------------------------
619 */
620/*
621 * All the ioctl commands get dispatched to functions with this
622 * prototype.
623 */
624typedef int (*ioctl_fn)(struct file *filp, struct dm_ioctl *param, size_t param_size);
625
626static int remove_all(struct file *filp, struct dm_ioctl *param, size_t param_size)
627{
628 int r;
629 int flags = DM_REMOVE_KEEP_OPEN_DEVICES | DM_REMOVE_INTERRUPTIBLE;
630 if (param->flags & DM_DEFERRED_REMOVE)
631 flags |= DM_REMOVE_MARK_DEFERRED;
632 r = dm_hash_remove_all(flags);
633 param->data_size = 0;
634 return r;
635}
636
637/*
638 * Round up the ptr to an 8-byte boundary.
639 */
640#define ALIGN_MASK 7
641static inline size_t align_val(size_t val)
642{
643 return (val + ALIGN_MASK) & ~ALIGN_MASK;
644}
645static inline void *align_ptr(void *ptr)
646{
647 return (void *)align_val((size_t)ptr);
648}
649
650/*
651 * Retrieves the data payload buffer from an already allocated
652 * struct dm_ioctl.
653 */
654static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
655 size_t *len)
656{
657 param->data_start = align_ptr(param + 1) - (void *) param;
658
659 if (param->data_start < param_size) {
660 *len = param_size - param->data_start;
661 } else {
662 /*
663 * The buffer can be as small as offsetof(*param, data), which
664 * is less than sizeof(*param), so don't run off the end of it.
665 */
666 *len = 0;
667 param->data_start = param_size;
668 }
669
670 return ((void *) param) + param->data_start;
671}
672
673static bool filter_device(struct hash_cell *hc, const char *pfx_name, const char *pfx_uuid)
674{
675 const char *val;
676 size_t val_len, pfx_len;
677
678 val = hc->name;
679 val_len = strlen(val);
680 pfx_len = strnlen(pfx_name, DM_NAME_LEN);
681 if (pfx_len > val_len)
682 return false;
683 if (memcmp(val, pfx_name, pfx_len))
684 return false;
685
686 val = hc->uuid ? hc->uuid : "";
687 val_len = strlen(val);
688 pfx_len = strnlen(pfx_uuid, DM_UUID_LEN);
689 if (pfx_len > val_len)
690 return false;
691 if (memcmp(val, pfx_uuid, pfx_len))
692 return false;
693
694 return true;
695}
696
697static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_size)
698{
699 struct rb_node *n;
700 struct hash_cell *hc;
701 size_t len;
702 struct dm_name_list *nl, *old_nl = NULL;
703 void *result_start, *result_limit;
704 uint32_t *event_nr;
705
706 /*
707 * Grab our output buffer.
708 */
709 nl = result_start = get_result_buffer(param, param_size, &len);
710 result_limit = result_start + len;
711
712 if (len >= sizeof(*nl))
713 nl->dev = 0; /* Flags no data */
714
715 down_write(&_hash_lock);
716
717 /*
718 * Loop through filling out the names.
719 */
720 for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {
721 void *next_nl;
722
723 hc = container_of(n, struct hash_cell, name_node);
724 if (!filter_device(hc, param->name, param->uuid))
725 continue;
726
727 len = strlen(hc->name);
728 event_nr = align_ptr(nl->name + len + 1);
729 next_nl = event_nr + 2;
730 if (next_nl > result_limit)
731 break;
732
733 ((u64 *)event_nr)[-1] = 0;
734 memcpy(nl->name, hc->name, len);
735
736 nl->dev = huge_encode_dev(disk_devt(dm_disk(hc->md)));
737
738 event_nr[0] = dm_get_event_nr(hc->md);
739 event_nr[1] = 0;
740
741 if (param->flags & DM_UUID_FLAG) {
742 if (hc->uuid) {
743 len = strlen(hc->uuid);
744 next_nl = align_ptr(next_nl + len + 1);
745 if (next_nl > result_limit)
746 break;
747 event_nr[1] |= DM_NAME_LIST_FLAG_HAS_UUID;
748 ((u64 *)next_nl)[-1] = 0;
749 memcpy(event_nr + 2, hc->uuid, len);
750 } else {
751 event_nr[1] |= DM_NAME_LIST_FLAG_DOESNT_HAVE_UUID;
752 }
753 }
754 nl->next = next_nl - (void *)nl;
755 old_nl = nl;
756 nl = next_nl;
757 }
758
759 if (old_nl)
760 old_nl->next = 0;
761
762 if (n)
763 param->flags |= DM_BUFFER_FULL_FLAG;
764 else
765 param->data_size = param->data_start + ((void *)nl - result_start);
766
767 up_write(&_hash_lock);
768 return 0;
769}
770
771static void list_version_get_info(struct target_type *tt, void *param)
772{
773 struct vers_iter *info = param;
774 struct dm_target_versions *vers = info->vers;
775 size_t name_len = strlen(tt->name);
776
777 if (!vers)
778 return;
779
780 info->old_vers = vers;
781 info->vers = align_ptr((void *)(info->vers + 1) + name_len + 1);
782
783 /* Check space */
784 if ((char *)info->vers > info->end) {
785 info->vers = NULL;
786 return;
787 }
788
789 /* Zero padding and terminate vers->name[] */
790 ((u64 *)info->vers)[-1] = 0;
791
792 vers->next = (char *)info->vers - (char *)vers;
793
794 vers->version[0] = tt->version[0];
795 vers->version[1] = tt->version[1];
796 vers->version[2] = tt->version[2];
797 memcpy(vers->name, tt->name, name_len);
798}
799
800static int __list_versions(struct dm_ioctl *param, size_t param_size, const char *name)
801{
802 size_t len;
803 struct dm_target_versions *vers;
804 struct vers_iter iter_info;
805 struct target_type *tt = NULL;
806
807 if (name) {
808 tt = dm_get_target_type(name);
809 if (!tt)
810 return -EINVAL;
811 }
812
813 /*
814 * Grab our output buffer.
815 */
816 vers = get_result_buffer(param, param_size, &len);
817
818 iter_info.old_vers = NULL;
819 iter_info.vers = vers;
820 iter_info.end = (char *)vers + len;
821
822 /*
823 * Loop through filling out the names & versions.
824 */
825 if (!tt)
826 dm_target_iterate(list_version_get_info, &iter_info);
827 else
828 list_version_get_info(tt, &iter_info);
829
830 if (iter_info.vers) {
831 if (iter_info.old_vers)
832 iter_info.old_vers->next = 0;
833 param->data_size = param->data_start + ((char *)iter_info.vers - (char *)vers);
834 } else {
835 param->flags |= DM_BUFFER_FULL_FLAG;
836 }
837
838 if (tt)
839 dm_put_target_type(tt);
840 return 0;
841}
842
843static int list_versions(struct file *filp, struct dm_ioctl *param, size_t param_size)
844{
845 return __list_versions(param, param_size, NULL);
846}
847
848static int get_target_version(struct file *filp, struct dm_ioctl *param, size_t param_size)
849{
850 return __list_versions(param, param_size, param->name);
851}
852
853static int check_name(const char *name)
854{
855 if (strchr(name, '/')) {
856 DMERR("device name cannot contain '/'");
857 return -EINVAL;
858 }
859
860 if (strcmp(name, DM_CONTROL_NODE) == 0 ||
861 strcmp(name, ".") == 0 ||
862 strcmp(name, "..") == 0) {
863 DMERR("device name cannot be \"%s\", \".\", or \"..\"", DM_CONTROL_NODE);
864 return -EINVAL;
865 }
866
867 return 0;
868}
869
870/*
871 * On successful return, the caller must not attempt to acquire
872 * _hash_lock without first calling dm_put_live_table, because dm_table_destroy
873 * waits for this dm_put_live_table and could be called under this lock.
874 */
875static struct dm_table *dm_get_inactive_table(struct mapped_device *md, int *srcu_idx)
876{
877 struct hash_cell *hc;
878 struct dm_table *table = NULL;
879
880 /* increment rcu count, we don't care about the table pointer */
881 dm_get_live_table(md, srcu_idx);
882
883 down_read(&_hash_lock);
884 hc = dm_get_mdptr(md);
885 if (!hc) {
886 DMERR("device has been removed from the dev hash table.");
887 goto out;
888 }
889
890 table = hc->new_map;
891
892out:
893 up_read(&_hash_lock);
894
895 return table;
896}
897
898static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
899 struct dm_ioctl *param,
900 int *srcu_idx)
901{
902 return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
903 dm_get_inactive_table(md, srcu_idx) : dm_get_live_table(md, srcu_idx);
904}
905
906/*
907 * Fills in a dm_ioctl structure, ready for sending back to
908 * userland.
909 */
910static void __dev_status(struct mapped_device *md, struct dm_ioctl *param)
911{
912 struct gendisk *disk = dm_disk(md);
913 struct dm_table *table;
914 int srcu_idx;
915
916 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
917 DM_ACTIVE_PRESENT_FLAG | DM_INTERNAL_SUSPEND_FLAG);
918
919 if (dm_suspended_md(md))
920 param->flags |= DM_SUSPEND_FLAG;
921
922 if (dm_suspended_internally_md(md))
923 param->flags |= DM_INTERNAL_SUSPEND_FLAG;
924
925 if (dm_test_deferred_remove_flag(md))
926 param->flags |= DM_DEFERRED_REMOVE;
927
928 param->dev = huge_encode_dev(disk_devt(disk));
929
930 /*
931 * Yes, this will be out of date by the time it gets back
932 * to userland, but it is still very useful for
933 * debugging.
934 */
935 param->open_count = dm_open_count(md);
936
937 param->event_nr = dm_get_event_nr(md);
938 param->target_count = 0;
939
940 table = dm_get_live_table(md, &srcu_idx);
941 if (table) {
942 if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
943 if (get_disk_ro(disk))
944 param->flags |= DM_READONLY_FLAG;
945 param->target_count = table->num_targets;
946 }
947
948 param->flags |= DM_ACTIVE_PRESENT_FLAG;
949 }
950 dm_put_live_table(md, srcu_idx);
951
952 if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
953 int srcu_idx;
954
955 table = dm_get_inactive_table(md, &srcu_idx);
956 if (table) {
957 if (!(dm_table_get_mode(table) & BLK_OPEN_WRITE))
958 param->flags |= DM_READONLY_FLAG;
959 param->target_count = table->num_targets;
960 }
961 dm_put_live_table(md, srcu_idx);
962 }
963}
964
965static int dev_create(struct file *filp, struct dm_ioctl *param, size_t param_size)
966{
967 int r, m = DM_ANY_MINOR;
968 struct mapped_device *md;
969
970 r = check_name(param->name);
971 if (r)
972 return r;
973
974 if (param->flags & DM_PERSISTENT_DEV_FLAG)
975 m = MINOR(huge_decode_dev(param->dev));
976
977 r = dm_create(m, &md);
978 if (r)
979 return r;
980
981 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
982 if (r) {
983 dm_put(md);
984 dm_destroy(md);
985 return r;
986 }
987
988 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
989
990 __dev_status(md, param);
991
992 dm_put(md);
993
994 return 0;
995}
996
997/*
998 * Always use UUID for lookups if it's present, otherwise use name or dev.
999 */
1000static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
1001{
1002 struct hash_cell *hc = NULL;
1003
1004 if (*param->uuid) {
1005 if (*param->name || param->dev) {
1006 DMERR("Invalid ioctl structure: uuid %s, name %s, dev %llx",
1007 param->uuid, param->name, (unsigned long long)param->dev);
1008 return NULL;
1009 }
1010
1011 hc = __get_uuid_cell(param->uuid);
1012 if (!hc)
1013 return NULL;
1014 } else if (*param->name) {
1015 if (param->dev) {
1016 DMERR("Invalid ioctl structure: name %s, dev %llx",
1017 param->name, (unsigned long long)param->dev);
1018 return NULL;
1019 }
1020
1021 hc = __get_name_cell(param->name);
1022 if (!hc)
1023 return NULL;
1024 } else if (param->dev) {
1025 hc = __get_dev_cell(param->dev);
1026 if (!hc)
1027 return NULL;
1028 } else
1029 return NULL;
1030
1031 /*
1032 * Sneakily write in both the name and the uuid
1033 * while we have the cell.
1034 */
1035 strscpy(param->name, hc->name, sizeof(param->name));
1036 if (hc->uuid)
1037 strscpy(param->uuid, hc->uuid, sizeof(param->uuid));
1038 else
1039 param->uuid[0] = '\0';
1040
1041 if (hc->new_map)
1042 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1043 else
1044 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1045
1046 return hc;
1047}
1048
1049static struct mapped_device *find_device(struct dm_ioctl *param)
1050{
1051 struct hash_cell *hc;
1052 struct mapped_device *md = NULL;
1053
1054 down_read(&_hash_lock);
1055 hc = __find_device_hash_cell(param);
1056 if (hc)
1057 md = hc->md;
1058 up_read(&_hash_lock);
1059
1060 return md;
1061}
1062
1063static int dev_remove(struct file *filp, struct dm_ioctl *param, size_t param_size)
1064{
1065 struct hash_cell *hc;
1066 struct mapped_device *md;
1067 int r;
1068 struct dm_table *t;
1069 struct dm_ima_context *ima_context = NULL;
1070 unsigned int ima_idx;
1071
1072 dm_ima_alloc_context(&ima_context, true);
1073 down_write(&_hash_lock);
1074 hc = __find_device_hash_cell(param);
1075
1076 if (!hc) {
1077 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1078 up_write(&_hash_lock);
1079 dm_ima_free_context(ima_context);
1080 return -ENXIO;
1081 }
1082
1083 md = hc->md;
1084
1085 /*
1086 * Ensure the device is not open and nothing further can open it.
1087 */
1088 r = dm_lock_for_deletion(md, !!(param->flags & DM_DEFERRED_REMOVE), false);
1089 if (r) {
1090 if (r == -EBUSY && param->flags & DM_DEFERRED_REMOVE) {
1091 up_write(&_hash_lock);
1092 dm_put(md);
1093 dm_ima_free_context(ima_context);
1094 return 0;
1095 }
1096 DMDEBUG_LIMIT("unable to remove open device %s", hc->name);
1097 up_write(&_hash_lock);
1098 dm_put(md);
1099 dm_ima_free_context(ima_context);
1100 return r;
1101 }
1102
1103 ima_idx = dm_ima_init_context(hc, ima_context, true);
1104 t = __hash_remove(hc);
1105 up_write(&_hash_lock);
1106
1107 if (t) {
1108 dm_sync_table(md);
1109 dm_table_destroy(t);
1110 }
1111
1112 param->flags &= ~DM_DEFERRED_REMOVE;
1113
1114 dm_ima_measure_on_device_remove(md, false, ima_context, ima_idx);
1115 dm_ima_free_context(ima_context);
1116
1117 if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr, false))
1118 param->flags |= DM_UEVENT_GENERATED_FLAG;
1119
1120 dm_put(md);
1121 dm_destroy(md);
1122 return 0;
1123}
1124
1125/*
1126 * Check a string doesn't overrun the chunk of
1127 * memory we copied from userland.
1128 */
1129static int invalid_str(char *str, void *end)
1130{
1131 while ((void *) str < end)
1132 if (!*str++)
1133 return 0;
1134
1135 return -EINVAL;
1136}
1137
1138static int dev_rename(struct file *filp, struct dm_ioctl *param, size_t param_size)
1139{
1140 int r;
1141 char *new_data = (char *) param + param->data_start;
1142 struct mapped_device *md;
1143 unsigned int change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
1144
1145 if (new_data < param->data ||
1146 invalid_str(new_data, (void *) param + param_size) || !*new_data ||
1147 strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
1148 DMERR("Invalid new mapped device name or uuid string supplied.");
1149 return -EINVAL;
1150 }
1151
1152 if (!change_uuid) {
1153 r = check_name(new_data);
1154 if (r)
1155 return r;
1156 }
1157
1158 md = dm_hash_rename(param, new_data);
1159 if (IS_ERR(md))
1160 return PTR_ERR(md);
1161
1162 __dev_status(md, param);
1163 dm_put(md);
1164
1165 return 0;
1166}
1167
1168static int dev_set_geometry(struct file *filp, struct dm_ioctl *param, size_t param_size)
1169{
1170 int r = -EINVAL, x;
1171 struct mapped_device *md;
1172 struct hd_geometry geometry;
1173 unsigned long indata[4];
1174 char *geostr = (char *) param + param->data_start;
1175 char dummy;
1176
1177 md = find_device(param);
1178 if (!md)
1179 return -ENXIO;
1180
1181 if (geostr < param->data ||
1182 invalid_str(geostr, (void *) param + param_size)) {
1183 DMERR("Invalid geometry supplied.");
1184 goto out;
1185 }
1186
1187 x = sscanf(geostr, "%lu %lu %lu %lu%c", indata,
1188 indata + 1, indata + 2, indata + 3, &dummy);
1189
1190 if (x != 4) {
1191 DMERR("Unable to interpret geometry settings.");
1192 goto out;
1193 }
1194
1195 if (indata[0] > 65535 || indata[1] > 255 || indata[2] > 255) {
1196 DMERR("Geometry exceeds range limits.");
1197 goto out;
1198 }
1199
1200 geometry.cylinders = indata[0];
1201 geometry.heads = indata[1];
1202 geometry.sectors = indata[2];
1203 geometry.start = indata[3];
1204
1205 r = dm_set_geometry(md, &geometry);
1206
1207 param->data_size = 0;
1208
1209out:
1210 dm_put(md);
1211 return r;
1212}
1213
1214static int do_suspend(struct dm_ioctl *param)
1215{
1216 int r = 0;
1217 unsigned int suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
1218 struct mapped_device *md;
1219
1220 md = find_device(param);
1221 if (!md)
1222 return -ENXIO;
1223
1224 if (param->flags & DM_SKIP_LOCKFS_FLAG)
1225 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
1226 if (param->flags & DM_NOFLUSH_FLAG)
1227 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
1228
1229 if (!dm_suspended_md(md)) {
1230 r = dm_suspend(md, suspend_flags);
1231 if (r)
1232 goto out;
1233 }
1234
1235 __dev_status(md, param);
1236
1237out:
1238 dm_put(md);
1239
1240 return r;
1241}
1242
1243static int do_resume(struct dm_ioctl *param)
1244{
1245 int r = 0;
1246 unsigned int suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
1247 struct hash_cell *hc;
1248 struct mapped_device *md;
1249 struct dm_table *new_map, *old_map = NULL;
1250 bool need_resize_uevent = false;
1251 struct dm_ima_context *ima_context = NULL;
1252
1253 dm_ima_alloc_context(&ima_context, true);
1254 down_write(&_hash_lock);
1255
1256 hc = __find_device_hash_cell(param);
1257 if (!hc) {
1258 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1259 up_write(&_hash_lock);
1260 dm_ima_free_context(ima_context);
1261 return -ENXIO;
1262 }
1263
1264 md = hc->md;
1265
1266 new_map = hc->new_map;
1267 hc->new_map = NULL;
1268 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1269 if (new_map)
1270 dm_ima_init_context(hc, ima_context, false);
1271 up_write(&_hash_lock);
1272
1273 /* Do we need to load a new map ? */
1274 if (new_map) {
1275 sector_t old_size, new_size;
1276 blk_mode_t new_map_mode;
1277
1278 dm_ima_context_table_op(md, ima_context, DM_IMA_TABLE_SAVE);
1279 /* Suspend if it isn't already suspended */
1280 if (param->flags & DM_SKIP_LOCKFS_FLAG)
1281 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
1282 if (param->flags & DM_NOFLUSH_FLAG)
1283 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
1284 if (!dm_suspended_md(md)) {
1285 r = dm_suspend(md, suspend_flags);
1286 if (r) {
1287 down_write(&_hash_lock);
1288 hc = dm_get_mdptr(md);
1289 if (hc && !hc->new_map) {
1290 hc->new_map = new_map;
1291 new_map = NULL;
1292 dm_ima_init_context(hc, ima_context,
1293 false);
1294 } else {
1295 r = -ENXIO;
1296 }
1297 up_write(&_hash_lock);
1298 if (new_map) {
1299 dm_sync_table(md);
1300 dm_table_destroy(new_map);
1301 } else
1302 dm_ima_context_table_op(md, ima_context, DM_IMA_TABLE_RESTORE);
1303 dm_ima_free_context(ima_context);
1304 dm_put(md);
1305 return r;
1306 }
1307 }
1308
1309 new_map_mode = dm_table_get_mode(new_map);
1310 old_size = dm_get_size(md);
1311 old_map = dm_swap_table(md, new_map);
1312 if (IS_ERR(old_map)) {
1313 dm_sync_table(md);
1314 dm_table_destroy(new_map);
1315 dm_ima_free_context(ima_context);
1316 dm_put(md);
1317 return PTR_ERR(old_map);
1318 }
1319 if (dm_ima_need_measure(md, new_map, ima_context))
1320 dm_ima_measure_on_device_resume(md, true, ima_context);
1321 new_size = dm_get_size(md);
1322 if (old_size && new_size && old_size != new_size)
1323 need_resize_uevent = true;
1324
1325 if (new_map_mode & BLK_OPEN_WRITE)
1326 set_disk_ro(dm_disk(md), 0);
1327 else
1328 set_disk_ro(dm_disk(md), 1);
1329 }
1330
1331 if (dm_suspended_md(md)) {
1332 r = dm_resume(md);
1333 if (!r) {
1334 if (!new_map && dm_ima_need_measure(md, NULL,
1335 ima_context))
1336 dm_ima_measure_on_device_resume(md, false,
1337 ima_context);
1338
1339 if (!dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr, need_resize_uevent))
1340 param->flags |= DM_UEVENT_GENERATED_FLAG;
1341 }
1342 }
1343
1344 /*
1345 * Since dm_swap_table synchronizes RCU, nobody should be in
1346 * read-side critical section already.
1347 */
1348 if (old_map)
1349 dm_table_destroy(old_map);
1350
1351 if (!r)
1352 __dev_status(md, param);
1353
1354 dm_ima_free_context(ima_context);
1355 dm_put(md);
1356 return r;
1357}
1358
1359/*
1360 * Set or unset the suspension state of a device.
1361 * If the device already is in the requested state we just return its status.
1362 */
1363static int dev_suspend(struct file *filp, struct dm_ioctl *param, size_t param_size)
1364{
1365 if (param->flags & DM_SUSPEND_FLAG)
1366 return do_suspend(param);
1367
1368 return do_resume(param);
1369}
1370
1371/*
1372 * Copies device info back to user space, used by
1373 * the create and info ioctls.
1374 */
1375static int dev_status(struct file *filp, struct dm_ioctl *param, size_t param_size)
1376{
1377 struct mapped_device *md;
1378
1379 md = find_device(param);
1380 if (!md)
1381 return -ENXIO;
1382
1383 __dev_status(md, param);
1384 dm_put(md);
1385
1386 return 0;
1387}
1388
1389/*
1390 * Build up the status struct for each target
1391 */
1392static void retrieve_status(struct dm_table *table,
1393 struct dm_ioctl *param, size_t param_size)
1394{
1395 unsigned int i, num_targets;
1396 struct dm_target_spec *spec;
1397 char *outbuf, *outptr;
1398 status_type_t type;
1399 size_t remaining, len, used = 0;
1400 unsigned int status_flags = 0;
1401
1402 outptr = outbuf = get_result_buffer(param, param_size, &len);
1403
1404 if (param->flags & DM_STATUS_TABLE_FLAG)
1405 type = STATUSTYPE_TABLE;
1406 else if (param->flags & DM_IMA_MEASUREMENT_FLAG)
1407 type = STATUSTYPE_IMA;
1408 else
1409 type = STATUSTYPE_INFO;
1410
1411 /* Get all the target info */
1412 num_targets = table->num_targets;
1413 for (i = 0; i < num_targets; i++) {
1414 struct dm_target *ti = dm_table_get_target(table, i);
1415 size_t l;
1416
1417 remaining = len - (outptr - outbuf);
1418 if (remaining <= sizeof(struct dm_target_spec)) {
1419 param->flags |= DM_BUFFER_FULL_FLAG;
1420 break;
1421 }
1422
1423 spec = (struct dm_target_spec *) outptr;
1424
1425 spec->status = 0;
1426 spec->sector_start = ti->begin;
1427 spec->length = ti->len;
1428 strscpy_pad(spec->target_type, ti->type->name,
1429 sizeof(spec->target_type));
1430
1431 outptr += sizeof(struct dm_target_spec);
1432 remaining = len - (outptr - outbuf);
1433
1434 /* Get the status/table string from the target driver */
1435 if (ti->type->status) {
1436 if (param->flags & DM_NOFLUSH_FLAG)
1437 status_flags |= DM_STATUS_NOFLUSH_FLAG;
1438 ti->type->status(ti, type, status_flags, outptr, remaining);
1439 } else
1440 outptr[0] = '\0';
1441
1442 l = strlen(outptr) + 1;
1443 if (l == remaining) {
1444 param->flags |= DM_BUFFER_FULL_FLAG;
1445 break;
1446 }
1447
1448 outptr += l;
1449 used = param->data_start + (outptr - outbuf);
1450
1451 outptr = align_ptr(outptr);
1452 if (!outptr || outptr > outbuf + len) {
1453 param->flags |= DM_BUFFER_FULL_FLAG;
1454 break;
1455 }
1456 spec->next = outptr - outbuf;
1457 }
1458
1459 if (used)
1460 param->data_size = used;
1461
1462 param->target_count = num_targets;
1463}
1464
1465/*
1466 * Wait for a device to report an event
1467 */
1468static int dev_wait(struct file *filp, struct dm_ioctl *param, size_t param_size)
1469{
1470 int r = 0;
1471 struct mapped_device *md;
1472 struct dm_table *table;
1473 int srcu_idx;
1474
1475 md = find_device(param);
1476 if (!md)
1477 return -ENXIO;
1478
1479 /*
1480 * Wait for a notification event
1481 */
1482 if (dm_wait_event(md, param->event_nr)) {
1483 r = -ERESTARTSYS;
1484 goto out;
1485 }
1486
1487 /*
1488 * The userland program is going to want to know what
1489 * changed to trigger the event, so we may as well tell
1490 * him and save an ioctl.
1491 */
1492 __dev_status(md, param);
1493
1494 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1495 if (table)
1496 retrieve_status(table, param, param_size);
1497 dm_put_live_table(md, srcu_idx);
1498
1499out:
1500 dm_put(md);
1501
1502 return r;
1503}
1504
1505/*
1506 * Remember the global event number and make it possible to poll
1507 * for further events.
1508 */
1509static int dev_arm_poll(struct file *filp, struct dm_ioctl *param, size_t param_size)
1510{
1511 struct dm_file *priv = filp->private_data;
1512
1513 priv->global_event_nr = atomic_read(&dm_global_event_nr);
1514
1515 return 0;
1516}
1517
1518static inline blk_mode_t get_mode(struct dm_ioctl *param)
1519{
1520 blk_mode_t mode = BLK_OPEN_READ | BLK_OPEN_WRITE;
1521
1522 if (param->flags & DM_READONLY_FLAG)
1523 mode = BLK_OPEN_READ;
1524
1525 return mode;
1526}
1527
1528static int next_target(struct dm_target_spec *last, uint32_t next, const char *end,
1529 struct dm_target_spec **spec, char **target_params)
1530{
1531 static_assert(__alignof__(struct dm_target_spec) <= 8,
1532 "struct dm_target_spec must not require more than 8-byte alignment");
1533
1534 /*
1535 * Number of bytes remaining, starting with last. This is always
1536 * sizeof(struct dm_target_spec) or more, as otherwise *last was
1537 * out of bounds already.
1538 */
1539 size_t remaining = end - (char *)last;
1540
1541 /*
1542 * There must be room for both the next target spec and the
1543 * NUL-terminator of the target itself.
1544 */
1545 if (remaining - sizeof(struct dm_target_spec) <= next) {
1546 DMERR("Target spec extends beyond end of parameters");
1547 return -EINVAL;
1548 }
1549
1550 if (next % __alignof__(struct dm_target_spec)) {
1551 DMERR("Next dm_target_spec (offset %u) is not %zu-byte aligned",
1552 next, __alignof__(struct dm_target_spec));
1553 return -EINVAL;
1554 }
1555
1556 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1557 *target_params = (char *) (*spec + 1);
1558
1559 return 0;
1560}
1561
1562static int populate_table(struct dm_table *table,
1563 struct dm_ioctl *param, size_t param_size)
1564{
1565 int r;
1566 unsigned int i = 0;
1567 struct dm_target_spec *spec = (struct dm_target_spec *) param;
1568 uint32_t next = param->data_start;
1569 const char *const end = (const char *) param + param_size;
1570 char *target_params;
1571 size_t min_size = sizeof(struct dm_ioctl);
1572
1573 if (!param->target_count) {
1574 DMERR("%s: no targets specified", __func__);
1575 return -EINVAL;
1576 }
1577
1578 for (i = 0; i < param->target_count; i++) {
1579 const char *nul_terminator;
1580
1581 if (next < min_size) {
1582 DMERR("%s: next target spec (offset %u) overlaps %s",
1583 __func__, next, i ? "previous target" : "'struct dm_ioctl'");
1584 return -EINVAL;
1585 }
1586
1587 r = next_target(spec, next, end, &spec, &target_params);
1588 if (r) {
1589 DMERR("unable to find target");
1590 return r;
1591 }
1592
1593 nul_terminator = memchr(target_params, 0, (size_t)(end - target_params));
1594 if (nul_terminator == NULL) {
1595 DMERR("%s: target parameters not NUL-terminated", __func__);
1596 return -EINVAL;
1597 }
1598
1599 /* Add 1 for NUL terminator */
1600 min_size = (size_t)(nul_terminator - (const char *)spec) + 1;
1601
1602 r = dm_table_add_target(table, spec->target_type,
1603 (sector_t) spec->sector_start,
1604 (sector_t) spec->length,
1605 target_params);
1606 if (r) {
1607 DMERR("error adding target to table");
1608 return r;
1609 }
1610
1611 next = spec->next;
1612 }
1613
1614 return dm_table_complete(table);
1615}
1616
1617static bool is_valid_type(enum dm_queue_mode cur, enum dm_queue_mode new)
1618{
1619 if (cur == new ||
1620 (cur == DM_TYPE_BIO_BASED && new == DM_TYPE_DAX_BIO_BASED))
1621 return true;
1622
1623 return false;
1624}
1625
1626static int table_load(struct file *filp, struct dm_ioctl *param, size_t param_size)
1627{
1628 int r, srcu_idx;
1629 struct hash_cell *hc;
1630 struct dm_table *t, *old_map = NULL;
1631 struct mapped_device *md;
1632 struct target_type *immutable_target_type;
1633 struct dm_ima_context *ima_context = NULL;
1634
1635 md = find_device(param);
1636 if (!md)
1637 return -ENXIO;
1638
1639 r = dm_table_create(&t, get_mode(param), param->target_count, md);
1640 if (r)
1641 goto err;
1642
1643 /* Protect md->type and md->queue against concurrent table loads. */
1644 dm_lock_md_type(md);
1645 r = populate_table(t, param, param_size);
1646 if (r)
1647 goto err_unlock_md_type;
1648
1649 immutable_target_type = dm_get_immutable_target_type(md);
1650 if (immutable_target_type &&
1651 (immutable_target_type != dm_table_get_immutable_target_type(t)) &&
1652 !dm_table_get_wildcard_target(t)) {
1653 DMERR("can't replace immutable target type %s",
1654 immutable_target_type->name);
1655 r = -EINVAL;
1656 goto err_unlock_md_type;
1657 }
1658
1659 if (dm_get_md_type(md) == DM_TYPE_NONE) {
1660 /* setup md->queue to reflect md's type (may block) */
1661 r = dm_setup_md_queue(md, t);
1662 if (r) {
1663 DMERR("unable to set up device queue for new table.");
1664 goto err_unlock_md_type;
1665 }
1666 } else if (!is_valid_type(dm_get_md_type(md), dm_table_get_type(t))) {
1667 DMERR("can't change device type (old=%u vs new=%u) after initial table load.",
1668 dm_get_md_type(md), dm_table_get_type(t));
1669 r = -EINVAL;
1670 goto err_unlock_md_type;
1671 }
1672
1673 dm_unlock_md_type(md);
1674
1675 dm_ima_alloc_context(&ima_context, false);
1676 /* stage inactive table */
1677 down_write(&_hash_lock);
1678 hc = dm_get_mdptr(md);
1679 if (!hc) {
1680 DMERR("device has been removed from the dev hash table.");
1681 up_write(&_hash_lock);
1682 dm_ima_free_context(ima_context);
1683 r = -ENXIO;
1684 goto err_destroy_table;
1685 }
1686
1687 if (hc->new_map)
1688 old_map = hc->new_map;
1689 hc->new_map = t;
1690 dm_ima_init_context(hc, ima_context, false);
1691 /* Make sure new_map doesn't get freed before we measure it*/
1692 dm_get_live_table(md, &srcu_idx);
1693 up_write(&_hash_lock);
1694
1695 dm_ima_measure_on_table_load(t, ima_context);
1696 dm_ima_free_context(ima_context);
1697 dm_put_live_table(md, srcu_idx);
1698
1699 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1700 __dev_status(md, param);
1701
1702 if (old_map) {
1703 dm_sync_table(md);
1704 dm_table_destroy(old_map);
1705 }
1706
1707 dm_put(md);
1708
1709 return 0;
1710
1711err_unlock_md_type:
1712 dm_unlock_md_type(md);
1713err_destroy_table:
1714 dm_table_destroy(t);
1715err:
1716 dm_put(md);
1717
1718 return r;
1719}
1720
1721static int table_clear(struct file *filp, struct dm_ioctl *param, size_t param_size)
1722{
1723 struct hash_cell *hc;
1724 struct mapped_device *md;
1725 struct dm_table *old_map = NULL;
1726 struct dm_ima_context *ima_context = NULL;
1727
1728 dm_ima_alloc_context(&ima_context, true);
1729 down_write(&_hash_lock);
1730
1731 hc = __find_device_hash_cell(param);
1732 if (!hc) {
1733 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1734 up_write(&_hash_lock);
1735 dm_ima_free_context(ima_context);
1736 return -ENXIO;
1737 }
1738
1739 if (hc->new_map) {
1740 old_map = hc->new_map;
1741 hc->new_map = NULL;
1742 }
1743
1744 dm_ima_init_context(hc, ima_context, false);
1745 md = hc->md;
1746 up_write(&_hash_lock);
1747 dm_ima_measure_on_table_clear(md, ima_context);
1748 dm_ima_free_context(ima_context);
1749
1750 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1751 __dev_status(md, param);
1752
1753 if (old_map) {
1754 dm_sync_table(md);
1755 dm_table_destroy(old_map);
1756 }
1757 dm_put(md);
1758
1759 return 0;
1760}
1761
1762/*
1763 * Retrieves a list of devices used by a particular dm device.
1764 */
1765static void retrieve_deps(struct dm_table *table,
1766 struct dm_ioctl *param, size_t param_size)
1767{
1768 unsigned int count = 0;
1769 struct list_head *tmp;
1770 size_t len, needed;
1771 struct dm_dev_internal *dd;
1772 struct dm_target_deps *deps;
1773
1774 deps = get_result_buffer(param, param_size, &len);
1775
1776 /*
1777 * Count the devices.
1778 */
1779 list_for_each(tmp, dm_table_get_devices(table))
1780 count++;
1781
1782 /*
1783 * Check we have enough space.
1784 */
1785 needed = struct_size(deps, dev, count);
1786 if (len < needed) {
1787 param->flags |= DM_BUFFER_FULL_FLAG;
1788 return;
1789 }
1790
1791 /*
1792 * Fill in the devices.
1793 */
1794 deps->count = count;
1795 count = 0;
1796 list_for_each_entry(dd, dm_table_get_devices(table), list)
1797 deps->dev[count++] = huge_encode_dev(dd->dm_dev->bdev->bd_dev);
1798
1799 param->data_size = param->data_start + needed;
1800}
1801
1802static int table_deps(struct file *filp, struct dm_ioctl *param, size_t param_size)
1803{
1804 struct mapped_device *md;
1805 struct dm_table *table;
1806 int srcu_idx;
1807
1808 md = find_device(param);
1809 if (!md)
1810 return -ENXIO;
1811
1812 __dev_status(md, param);
1813
1814 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1815 if (table)
1816 retrieve_deps(table, param, param_size);
1817 dm_put_live_table(md, srcu_idx);
1818
1819 dm_put(md);
1820
1821 return 0;
1822}
1823
1824/*
1825 * Return the status of a device as a text string for each
1826 * target.
1827 */
1828static int table_status(struct file *filp, struct dm_ioctl *param, size_t param_size)
1829{
1830 struct mapped_device *md;
1831 struct dm_table *table;
1832 int srcu_idx;
1833
1834 md = find_device(param);
1835 if (!md)
1836 return -ENXIO;
1837
1838 __dev_status(md, param);
1839
1840 table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1841 if (table)
1842 retrieve_status(table, param, param_size);
1843 dm_put_live_table(md, srcu_idx);
1844
1845 dm_put(md);
1846
1847 return 0;
1848}
1849
1850/*
1851 * Process device-mapper dependent messages. Messages prefixed with '@'
1852 * are processed by the DM core. All others are delivered to the target.
1853 * Returns a number <= 1 if message was processed by device mapper.
1854 * Returns 2 if message should be delivered to the target.
1855 */
1856static int message_for_md(struct mapped_device *md, unsigned int argc, char **argv,
1857 char *result, unsigned int maxlen)
1858{
1859 int r;
1860
1861 if (**argv != '@')
1862 return 2; /* no '@' prefix, deliver to target */
1863
1864 if (!strcasecmp(argv[0], "@cancel_deferred_remove")) {
1865 if (argc != 1) {
1866 DMERR("Invalid arguments for @cancel_deferred_remove");
1867 return -EINVAL;
1868 }
1869 return dm_cancel_deferred_remove(md);
1870 }
1871
1872 r = dm_stats_message(md, argc, argv, result, maxlen);
1873 if (r < 2)
1874 return r;
1875
1876 DMERR("Unsupported message sent to DM core: %s", argv[0]);
1877 return -EINVAL;
1878}
1879
1880/*
1881 * Pass a message to the target that's at the supplied device offset.
1882 */
1883static int target_message(struct file *filp, struct dm_ioctl *param, size_t param_size)
1884{
1885 int r, argc;
1886 char **argv;
1887 struct mapped_device *md;
1888 struct dm_table *table;
1889 struct dm_target *ti;
1890 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1891 size_t maxlen;
1892 char *result = get_result_buffer(param, param_size, &maxlen);
1893 int srcu_idx;
1894
1895 md = find_device(param);
1896 if (!md)
1897 return -ENXIO;
1898
1899 if (tmsg < (struct dm_target_msg *) param->data ||
1900 invalid_str(tmsg->message, (void *) param + param_size)) {
1901 DMERR("Invalid target message parameters.");
1902 r = -EINVAL;
1903 goto out;
1904 }
1905
1906 r = dm_split_args(&argc, &argv, tmsg->message);
1907 if (r) {
1908 DMERR("Failed to split target message parameters");
1909 goto out;
1910 }
1911
1912 if (!argc) {
1913 DMERR("Empty message received.");
1914 r = -EINVAL;
1915 goto out_argv;
1916 }
1917
1918 r = message_for_md(md, argc, argv, result, maxlen);
1919 if (r <= 1)
1920 goto out_argv;
1921
1922 table = dm_get_live_table(md, &srcu_idx);
1923 if (!table) {
1924 DMERR("The device has no table.");
1925 r = -EINVAL;
1926 goto out_table;
1927 }
1928
1929 if (dm_deleting_md(md)) {
1930 r = -ENXIO;
1931 goto out_table;
1932 }
1933
1934 ti = dm_table_find_target(table, tmsg->sector);
1935 if (!ti) {
1936 DMERR("Target message sector outside device.");
1937 r = -EINVAL;
1938 } else if (ti->type->message)
1939 r = ti->type->message(ti, argc, argv, result, maxlen);
1940 else {
1941 DMERR("Target type does not support messages");
1942 r = -EINVAL;
1943 }
1944
1945 out_table:
1946 dm_put_live_table(md, srcu_idx);
1947 out_argv:
1948 kfree(argv);
1949 out:
1950 if (r >= 0)
1951 __dev_status(md, param);
1952
1953 if (r == 1) {
1954 param->flags |= DM_DATA_OUT_FLAG;
1955 if (dm_message_test_buffer_overflow(result, maxlen))
1956 param->flags |= DM_BUFFER_FULL_FLAG;
1957 else
1958 param->data_size = param->data_start + strlen(result) + 1;
1959 r = 0;
1960 }
1961
1962 dm_put(md);
1963 return r;
1964}
1965
1966/*
1967 * The ioctl parameter block consists of two parts, a dm_ioctl struct
1968 * followed by a data buffer. This flag is set if the second part,
1969 * which has a variable size, is not used by the function processing
1970 * the ioctl.
1971 */
1972#define IOCTL_FLAGS_NO_PARAMS 1
1973#define IOCTL_FLAGS_ISSUE_GLOBAL_EVENT 2
1974
1975/*
1976 *---------------------------------------------------------------
1977 * Implementation of open/close/ioctl on the special char device.
1978 *---------------------------------------------------------------
1979 */
1980static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags)
1981{
1982 static const struct {
1983 int flags;
1984 ioctl_fn fn;
1985 } _ioctls[] = {
1986 [DM_VERSION_CMD] = {0, NULL}, /* version is dealt with elsewhere */
1987 [DM_REMOVE_ALL_CMD] = {IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, remove_all},
1988 [DM_LIST_DEVICES_CMD] = {0, list_devices},
1989
1990 [DM_DEV_CREATE_CMD] = {IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_create},
1991 [DM_DEV_REMOVE_CMD] = {IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_remove},
1992 [DM_DEV_RENAME_CMD] = {IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_rename},
1993 [DM_DEV_SUSPEND_CMD] = {IOCTL_FLAGS_NO_PARAMS, dev_suspend},
1994 [DM_DEV_STATUS_CMD] = {IOCTL_FLAGS_NO_PARAMS, dev_status},
1995 [DM_DEV_WAIT_CMD] = {0, dev_wait},
1996
1997 [DM_TABLE_LOAD_CMD] = {0, table_load},
1998 [DM_TABLE_CLEAR_CMD] = {IOCTL_FLAGS_NO_PARAMS, table_clear},
1999 [DM_TABLE_DEPS_CMD] = {0, table_deps},
2000 [DM_TABLE_STATUS_CMD] = {0, table_status},
2001
2002 [DM_LIST_VERSIONS_CMD] = {0, list_versions},
2003
2004 [DM_TARGET_MSG_CMD] = {0, target_message},
2005 [DM_DEV_SET_GEOMETRY_CMD] = {0, dev_set_geometry},
2006 [DM_DEV_ARM_POLL_CMD] = {IOCTL_FLAGS_NO_PARAMS, dev_arm_poll},
2007 [DM_GET_TARGET_VERSION_CMD] = {0, get_target_version},
2008 [DM_MPATH_PROBE_PATHS_CMD] = {0, NULL}, /* block device ioctl */
2009 };
2010
2011 if (unlikely(cmd >= ARRAY_SIZE(_ioctls)))
2012 return NULL;
2013
2014 cmd = array_index_nospec(cmd, ARRAY_SIZE(_ioctls));
2015 *ioctl_flags = _ioctls[cmd].flags;
2016 return _ioctls[cmd].fn;
2017}
2018
2019/*
2020 * As well as checking the version compatibility this always
2021 * copies the kernel interface version out.
2022 */
2023static int check_version(unsigned int cmd, struct dm_ioctl __user *user,
2024 struct dm_ioctl *kernel_params)
2025{
2026 int r = 0;
2027
2028 /* Make certain version is first member of dm_ioctl struct */
2029 BUILD_BUG_ON(offsetof(struct dm_ioctl, version) != 0);
2030
2031 if (copy_from_user(kernel_params->version, user->version, sizeof(kernel_params->version)))
2032 return -EFAULT;
2033
2034 if ((kernel_params->version[0] != DM_VERSION_MAJOR) ||
2035 (kernel_params->version[1] > DM_VERSION_MINOR)) {
2036 DMERR_LIMIT("ioctl interface mismatch: kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
2037 DM_VERSION_MAJOR, DM_VERSION_MINOR,
2038 DM_VERSION_PATCHLEVEL,
2039 kernel_params->version[0],
2040 kernel_params->version[1],
2041 kernel_params->version[2],
2042 cmd);
2043 r = -EINVAL;
2044 }
2045
2046 /*
2047 * Fill in the kernel version.
2048 */
2049 kernel_params->version[0] = DM_VERSION_MAJOR;
2050 kernel_params->version[1] = DM_VERSION_MINOR;
2051 kernel_params->version[2] = DM_VERSION_PATCHLEVEL;
2052 if (copy_to_user(user->version, kernel_params->version, sizeof(kernel_params->version)))
2053 return -EFAULT;
2054
2055 return r;
2056}
2057
2058#define DM_PARAMS_MALLOC 0x0001 /* Params allocated with kvmalloc() */
2059#define DM_WIPE_BUFFER 0x0010 /* Wipe input buffer before returning from ioctl */
2060
2061static void free_params(struct dm_ioctl *param, size_t param_size, int param_flags)
2062{
2063 if (param_flags & DM_WIPE_BUFFER)
2064 memset(param, 0, param_size);
2065
2066 if (param_flags & DM_PARAMS_MALLOC)
2067 kvfree(param);
2068}
2069
2070static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel,
2071 int ioctl_flags, struct dm_ioctl **param, int *param_flags)
2072{
2073 struct dm_ioctl *dmi;
2074 int secure_data;
2075 const size_t minimum_data_size = offsetof(struct dm_ioctl, data);
2076
2077 /* check_version() already copied version from userspace, avoid TOCTOU */
2078 if (copy_from_user((char *)param_kernel + sizeof(param_kernel->version),
2079 (char __user *)user + sizeof(param_kernel->version),
2080 minimum_data_size - sizeof(param_kernel->version)))
2081 return -EFAULT;
2082
2083 if (unlikely(param_kernel->data_size < minimum_data_size) ||
2084 unlikely(param_kernel->data_size > DM_MAX_TARGETS * DM_MAX_TARGET_PARAMS)) {
2085 DMERR_LIMIT("Invalid data size in the ioctl structure: %u",
2086 param_kernel->data_size);
2087 return -EINVAL;
2088 }
2089
2090 secure_data = param_kernel->flags & DM_SECURE_DATA_FLAG;
2091
2092 *param_flags = secure_data ? DM_WIPE_BUFFER : 0;
2093
2094 if (ioctl_flags & IOCTL_FLAGS_NO_PARAMS) {
2095 dmi = param_kernel;
2096 dmi->data_size = minimum_data_size;
2097 goto data_copied;
2098 }
2099
2100 /*
2101 * Use __GFP_HIGH to avoid low memory issues when a device is
2102 * suspended and the ioctl is needed to resume it.
2103 * Use kmalloc() rather than vmalloc() when we can.
2104 */
2105 dmi = NULL;
2106 dmi = kvmalloc(param_kernel->data_size, GFP_NOIO | __GFP_HIGH);
2107
2108 if (!dmi) {
2109 if (secure_data && clear_user(user, param_kernel->data_size))
2110 return -EFAULT;
2111 return -ENOMEM;
2112 }
2113
2114 *param_flags |= DM_PARAMS_MALLOC;
2115
2116 /* Copy from param_kernel (which was already copied from user) */
2117 memcpy(dmi, param_kernel, minimum_data_size);
2118
2119 if (copy_from_user(&dmi->data, (char __user *)user + minimum_data_size,
2120 param_kernel->data_size - minimum_data_size))
2121 goto bad;
2122data_copied:
2123 /* Wipe the user buffer so we do not return it to userspace */
2124 if (secure_data && clear_user(user, param_kernel->data_size))
2125 goto bad;
2126
2127 *param = dmi;
2128 return 0;
2129
2130bad:
2131 free_params(dmi, param_kernel->data_size, *param_flags);
2132
2133 return -EFAULT;
2134}
2135
2136static int validate_params(uint cmd, struct dm_ioctl *param)
2137{
2138 /* Always clear this flag */
2139 param->flags &= ~DM_BUFFER_FULL_FLAG;
2140 param->flags &= ~DM_UEVENT_GENERATED_FLAG;
2141 param->flags &= ~DM_SECURE_DATA_FLAG;
2142 param->flags &= ~DM_DATA_OUT_FLAG;
2143
2144 /* Ignores parameters */
2145 if (cmd == DM_REMOVE_ALL_CMD ||
2146 cmd == DM_LIST_DEVICES_CMD ||
2147 cmd == DM_LIST_VERSIONS_CMD)
2148 return 0;
2149
2150 if (cmd == DM_DEV_CREATE_CMD) {
2151 if (!*param->name) {
2152 DMERR("name not supplied when creating device");
2153 return -EINVAL;
2154 }
2155 } else if (*param->uuid && *param->name) {
2156 DMERR("only supply one of name or uuid, cmd(%u)", cmd);
2157 return -EINVAL;
2158 }
2159
2160 /* Ensure strings are terminated */
2161 param->name[DM_NAME_LEN - 1] = '\0';
2162 param->uuid[DM_UUID_LEN - 1] = '\0';
2163
2164 return 0;
2165}
2166
2167static int ctl_ioctl(struct file *file, uint command, struct dm_ioctl __user *user)
2168{
2169 int r = 0;
2170 int ioctl_flags;
2171 int param_flags;
2172 unsigned int cmd;
2173 struct dm_ioctl *param;
2174 ioctl_fn fn = NULL;
2175 size_t input_param_size;
2176 struct dm_ioctl param_kernel;
2177
2178 /* only root can play with this */
2179 if (!capable(CAP_SYS_ADMIN))
2180 return -EACCES;
2181
2182 if (_IOC_TYPE(command) != DM_IOCTL)
2183 return -ENOTTY;
2184
2185 cmd = _IOC_NR(command);
2186
2187 /*
2188 * Check the interface version passed in. This also
2189 * writes out the kernel's interface version.
2190 */
2191 r = check_version(cmd, user, &param_kernel);
2192 if (r)
2193 return r;
2194
2195 /*
2196 * Nothing more to do for the version command.
2197 */
2198 if (cmd == DM_VERSION_CMD)
2199 return 0;
2200
2201 fn = lookup_ioctl(cmd, &ioctl_flags);
2202 if (!fn) {
2203 DMERR("dm_ctl_ioctl: unknown command 0x%x", command);
2204 return -ENOTTY;
2205 }
2206
2207 /*
2208 * Copy the parameters into kernel space.
2209 */
2210 r = copy_params(user, &param_kernel, ioctl_flags, &param, &param_flags);
2211
2212 if (r)
2213 return r;
2214
2215 input_param_size = param->data_size;
2216 r = validate_params(cmd, param);
2217 if (r)
2218 goto out;
2219
2220 param->data_size = offsetof(struct dm_ioctl, data);
2221 r = fn(file, param, input_param_size);
2222
2223 if (unlikely(param->flags & DM_BUFFER_FULL_FLAG) &&
2224 unlikely(ioctl_flags & IOCTL_FLAGS_NO_PARAMS))
2225 DMERR("ioctl %d tried to output some data but has IOCTL_FLAGS_NO_PARAMS set", cmd);
2226
2227 if (!r && ioctl_flags & IOCTL_FLAGS_ISSUE_GLOBAL_EVENT)
2228 dm_issue_global_event();
2229
2230 /*
2231 * Copy the results back to userland.
2232 */
2233 if (!r && copy_to_user(user, param, param->data_size))
2234 r = -EFAULT;
2235
2236out:
2237 free_params(param, input_param_size, param_flags);
2238 return r;
2239}
2240
2241static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
2242{
2243 return (long)ctl_ioctl(file, command, (struct dm_ioctl __user *)u);
2244}
2245
2246#ifdef CONFIG_COMPAT
2247static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
2248{
2249 return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
2250}
2251#else
2252#define dm_compat_ctl_ioctl NULL
2253#endif
2254
2255static int dm_open(struct inode *inode, struct file *filp)
2256{
2257 struct dm_file *priv;
2258
2259 nonseekable_open(inode, filp);
2260
2261 priv = filp->private_data = kmalloc_obj(struct dm_file);
2262 if (!priv)
2263 return -ENOMEM;
2264
2265 priv->global_event_nr = atomic_read(&dm_global_event_nr);
2266
2267 return 0;
2268}
2269
2270static int dm_release(struct inode *inode, struct file *filp)
2271{
2272 kfree(filp->private_data);
2273 return 0;
2274}
2275
2276static __poll_t dm_poll(struct file *filp, poll_table *wait)
2277{
2278 struct dm_file *priv = filp->private_data;
2279 __poll_t mask = 0;
2280
2281 poll_wait(filp, &dm_global_eventq, wait);
2282
2283 if ((int)(atomic_read(&dm_global_event_nr) - priv->global_event_nr) > 0)
2284 mask |= EPOLLIN;
2285
2286 return mask;
2287}
2288
2289static const struct file_operations _ctl_fops = {
2290 .open = dm_open,
2291 .release = dm_release,
2292 .poll = dm_poll,
2293 .unlocked_ioctl = dm_ctl_ioctl,
2294 .compat_ioctl = dm_compat_ctl_ioctl,
2295 .owner = THIS_MODULE,
2296 .llseek = noop_llseek,
2297};
2298
2299static struct miscdevice _dm_misc = {
2300 .minor = MAPPER_CTRL_MINOR,
2301 .name = DM_NAME,
2302 .nodename = DM_DIR "/" DM_CONTROL_NODE,
2303 .fops = &_ctl_fops
2304};
2305
2306MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
2307MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
2308
2309/*
2310 * Create misc character device and link to DM_DIR/control.
2311 */
2312int __init dm_interface_init(void)
2313{
2314 int r;
2315
2316 r = misc_register(&_dm_misc);
2317 if (r) {
2318 DMERR("misc_register failed for control device");
2319 return r;
2320 }
2321
2322 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
2323 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
2324 DM_DRIVER_EMAIL);
2325 return 0;
2326}
2327
2328void dm_interface_exit(void)
2329{
2330 misc_deregister(&_dm_misc);
2331 dm_hash_exit();
2332}
2333
2334/**
2335 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
2336 * @md: Pointer to mapped_device
2337 * @name: Buffer (size DM_NAME_LEN) for name
2338 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
2339 */
2340int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
2341{
2342 int r = 0;
2343 struct hash_cell *hc;
2344
2345 if (!md)
2346 return -ENXIO;
2347
2348 mutex_lock(&dm_hash_cells_mutex);
2349 hc = dm_get_mdptr(md);
2350 if (!hc) {
2351 r = -ENXIO;
2352 goto out;
2353 }
2354
2355 if (name)
2356 strcpy(name, hc->name);
2357 if (uuid)
2358 strcpy(uuid, hc->uuid ? : "");
2359
2360out:
2361 mutex_unlock(&dm_hash_cells_mutex);
2362
2363 return r;
2364}
2365EXPORT_SYMBOL_GPL(dm_copy_name_and_uuid);
2366
2367/**
2368 * dm_early_create - create a mapped device in early boot.
2369 *
2370 * @dmi: Contains main information of the device mapping to be created.
2371 * @spec_array: array of pointers to struct dm_target_spec. Describes the
2372 * mapping table of the device.
2373 * @target_params_array: array of strings with the parameters to a specific
2374 * target.
2375 *
2376 * Instead of having the struct dm_target_spec and the parameters for every
2377 * target embedded at the end of struct dm_ioctl (as performed in a normal
2378 * ioctl), pass them as arguments, so the caller doesn't need to serialize them.
2379 * The size of the spec_array and target_params_array is given by
2380 * @dmi->target_count.
2381 * This function is supposed to be called in early boot, so locking mechanisms
2382 * to protect against concurrent loads are not required.
2383 */
2384int __init dm_early_create(struct dm_ioctl *dmi,
2385 struct dm_target_spec **spec_array,
2386 char **target_params_array)
2387{
2388 int r, m = DM_ANY_MINOR;
2389 struct dm_table *t, *old_map;
2390 struct mapped_device *md;
2391 unsigned int i;
2392
2393 if (!dmi->target_count)
2394 return -EINVAL;
2395
2396 r = check_name(dmi->name);
2397 if (r)
2398 return r;
2399
2400 if (dmi->flags & DM_PERSISTENT_DEV_FLAG)
2401 m = MINOR(huge_decode_dev(dmi->dev));
2402
2403 /* alloc dm device */
2404 r = dm_create(m, &md);
2405 if (r)
2406 return r;
2407
2408 /* hash insert */
2409 r = dm_hash_insert(dmi->name, *dmi->uuid ? dmi->uuid : NULL, md);
2410 if (r)
2411 goto err_destroy_dm;
2412
2413 /* alloc table */
2414 r = dm_table_create(&t, get_mode(dmi), dmi->target_count, md);
2415 if (r)
2416 goto err_hash_remove;
2417
2418 /* add targets */
2419 for (i = 0; i < dmi->target_count; i++) {
2420 r = dm_table_add_target(t, spec_array[i]->target_type,
2421 (sector_t) spec_array[i]->sector_start,
2422 (sector_t) spec_array[i]->length,
2423 target_params_array[i]);
2424 if (r) {
2425 DMERR("error adding target to table");
2426 goto err_destroy_table;
2427 }
2428 }
2429
2430 /* finish table */
2431 r = dm_table_complete(t);
2432 if (r)
2433 goto err_destroy_table;
2434
2435 /* setup md->queue to reflect md's type (may block) */
2436 r = dm_setup_md_queue(md, t);
2437 if (r) {
2438 DMERR("unable to set up device queue for new table.");
2439 goto err_destroy_table;
2440 }
2441
2442 /* Set new map */
2443 dm_suspend(md, 0);
2444 old_map = dm_swap_table(md, t);
2445 if (IS_ERR(old_map)) {
2446 r = PTR_ERR(old_map);
2447 goto err_destroy_table;
2448 }
2449 set_disk_ro(dm_disk(md), !!(dmi->flags & DM_READONLY_FLAG));
2450
2451 /* resume device */
2452 r = dm_resume(md);
2453 if (r)
2454 goto err_hash_remove;
2455
2456 DMINFO("%s (%s) is ready", md->disk->disk_name, dmi->name);
2457 dm_put(md);
2458 return 0;
2459
2460err_destroy_table:
2461 dm_table_destroy(t);
2462err_hash_remove:
2463 down_write(&_hash_lock);
2464 (void) __hash_remove(__get_name_cell(dmi->name));
2465 up_write(&_hash_lock);
2466 /* release reference from __get_name_cell */
2467 dm_put(md);
2468err_destroy_dm:
2469 dm_put(md);
2470 dm_destroy(md);
2471 return r;
2472}