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 "dm-devel@lists.linux.dev"
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 size_t param_size;
58 struct dm_target_versions *vers, *old_vers;
59 char *end;
60 uint32_t flags;
61};
62
63
64static struct rb_root name_rb_tree = RB_ROOT;
65static struct rb_root uuid_rb_tree = RB_ROOT;
66
67static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred);
68
69/*
70 * Guards access to both hash tables.
71 */
72static DECLARE_RWSEM(_hash_lock);
73
74/*
75 * Protects use of mdptr to obtain hash cell name and uuid from mapped device.
76 */
77static DEFINE_MUTEX(dm_hash_cells_mutex);
78
79static void dm_hash_exit(void)
80{
81 dm_hash_remove_all(keep_open_devices: false, mark_deferred: false, only_deferred: false);
82}
83
84/*
85 *---------------------------------------------------------------
86 * Code for looking up a device by name
87 *---------------------------------------------------------------
88 */
89static struct hash_cell *__get_name_cell(const char *str)
90{
91 struct rb_node *n = name_rb_tree.rb_node;
92
93 while (n) {
94 struct hash_cell *hc = container_of(n, struct hash_cell, name_node);
95 int c;
96
97 c = strcmp(hc->name, str);
98 if (!c) {
99 dm_get(md: hc->md);
100 return hc;
101 }
102 n = c >= 0 ? n->rb_left : n->rb_right;
103 }
104
105 return NULL;
106}
107
108static struct hash_cell *__get_uuid_cell(const char *str)
109{
110 struct rb_node *n = uuid_rb_tree.rb_node;
111
112 while (n) {
113 struct hash_cell *hc = container_of(n, struct hash_cell, uuid_node);
114 int c;
115
116 c = strcmp(hc->uuid, str);
117 if (!c) {
118 dm_get(md: hc->md);
119 return hc;
120 }
121 n = c >= 0 ? n->rb_left : n->rb_right;
122 }
123
124 return NULL;
125}
126
127static void __unlink_name(struct hash_cell *hc)
128{
129 if (hc->name_set) {
130 hc->name_set = false;
131 rb_erase(&hc->name_node, &name_rb_tree);
132 }
133}
134
135static void __unlink_uuid(struct hash_cell *hc)
136{
137 if (hc->uuid_set) {
138 hc->uuid_set = false;
139 rb_erase(&hc->uuid_node, &uuid_rb_tree);
140 }
141}
142
143static void __link_name(struct hash_cell *new_hc)
144{
145 struct rb_node **n, *parent;
146
147 __unlink_name(hc: new_hc);
148
149 new_hc->name_set = true;
150
151 n = &name_rb_tree.rb_node;
152 parent = NULL;
153
154 while (*n) {
155 struct hash_cell *hc = container_of(*n, struct hash_cell, name_node);
156 int c;
157
158 c = strcmp(hc->name, new_hc->name);
159 BUG_ON(!c);
160 parent = *n;
161 n = c >= 0 ? &hc->name_node.rb_left : &hc->name_node.rb_right;
162 }
163
164 rb_link_node(node: &new_hc->name_node, parent, rb_link: n);
165 rb_insert_color(&new_hc->name_node, &name_rb_tree);
166}
167
168static void __link_uuid(struct hash_cell *new_hc)
169{
170 struct rb_node **n, *parent;
171
172 __unlink_uuid(hc: new_hc);
173
174 new_hc->uuid_set = true;
175
176 n = &uuid_rb_tree.rb_node;
177 parent = NULL;
178
179 while (*n) {
180 struct hash_cell *hc = container_of(*n, struct hash_cell, uuid_node);
181 int c;
182
183 c = strcmp(hc->uuid, new_hc->uuid);
184 BUG_ON(!c);
185 parent = *n;
186 n = c > 0 ? &hc->uuid_node.rb_left : &hc->uuid_node.rb_right;
187 }
188
189 rb_link_node(node: &new_hc->uuid_node, parent, rb_link: n);
190 rb_insert_color(&new_hc->uuid_node, &uuid_rb_tree);
191}
192
193static struct hash_cell *__get_dev_cell(uint64_t dev)
194{
195 struct mapped_device *md;
196 struct hash_cell *hc;
197
198 md = dm_get_md(dev: huge_decode_dev(dev));
199 if (!md)
200 return NULL;
201
202 hc = dm_get_mdptr(md);
203 if (!hc) {
204 dm_put(md);
205 return NULL;
206 }
207
208 return hc;
209}
210
211/*
212 *---------------------------------------------------------------
213 * Inserting, removing and renaming a device.
214 *---------------------------------------------------------------
215 */
216static struct hash_cell *alloc_cell(const char *name, const char *uuid,
217 struct mapped_device *md)
218{
219 struct hash_cell *hc;
220
221 hc = kmalloc(sizeof(*hc), GFP_KERNEL);
222 if (!hc)
223 return NULL;
224
225 hc->name = kstrdup(s: name, GFP_KERNEL);
226 if (!hc->name) {
227 kfree(objp: hc);
228 return NULL;
229 }
230
231 if (!uuid)
232 hc->uuid = NULL;
233
234 else {
235 hc->uuid = kstrdup(s: uuid, GFP_KERNEL);
236 if (!hc->uuid) {
237 kfree(objp: hc->name);
238 kfree(objp: hc);
239 return NULL;
240 }
241 }
242
243 hc->name_set = hc->uuid_set = false;
244 hc->md = md;
245 hc->new_map = NULL;
246 return hc;
247}
248
249static void free_cell(struct hash_cell *hc)
250{
251 if (hc) {
252 kfree(objp: hc->name);
253 kfree(objp: hc->uuid);
254 kfree(objp: hc);
255 }
256}
257
258/*
259 * The kdev_t and uuid of a device can never change once it is
260 * initially inserted.
261 */
262static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
263{
264 struct hash_cell *cell, *hc;
265
266 /*
267 * Allocate the new cells.
268 */
269 cell = alloc_cell(name, uuid, md);
270 if (!cell)
271 return -ENOMEM;
272
273 /*
274 * Insert the cell into both hash tables.
275 */
276 down_write(sem: &_hash_lock);
277 hc = __get_name_cell(str: name);
278 if (hc) {
279 dm_put(md: hc->md);
280 goto bad;
281 }
282
283 __link_name(new_hc: cell);
284
285 if (uuid) {
286 hc = __get_uuid_cell(str: uuid);
287 if (hc) {
288 __unlink_name(hc: cell);
289 dm_put(md: hc->md);
290 goto bad;
291 }
292 __link_uuid(new_hc: cell);
293 }
294 dm_get(md);
295 mutex_lock(lock: &dm_hash_cells_mutex);
296 dm_set_mdptr(md, ptr: cell);
297 mutex_unlock(lock: &dm_hash_cells_mutex);
298 up_write(sem: &_hash_lock);
299
300 return 0;
301
302 bad:
303 up_write(sem: &_hash_lock);
304 free_cell(hc: cell);
305 return -EBUSY;
306}
307
308static struct dm_table *__hash_remove(struct hash_cell *hc)
309{
310 struct dm_table *table;
311 int srcu_idx;
312
313 lockdep_assert_held(&_hash_lock);
314
315 /* remove from the dev trees */
316 __unlink_name(hc);
317 __unlink_uuid(hc);
318 mutex_lock(lock: &dm_hash_cells_mutex);
319 dm_set_mdptr(md: hc->md, NULL);
320 mutex_unlock(lock: &dm_hash_cells_mutex);
321
322 table = dm_get_live_table(md: hc->md, srcu_idx: &srcu_idx);
323 if (table)
324 dm_table_event(t: table);
325 dm_put_live_table(md: hc->md, srcu_idx);
326
327 table = NULL;
328 if (hc->new_map)
329 table = hc->new_map;
330 dm_put(md: hc->md);
331 free_cell(hc);
332
333 return table;
334}
335
336static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred)
337{
338 int dev_skipped;
339 struct rb_node *n;
340 struct hash_cell *hc;
341 struct mapped_device *md;
342 struct dm_table *t;
343
344retry:
345 dev_skipped = 0;
346
347 down_write(sem: &_hash_lock);
348
349 for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {
350 hc = container_of(n, struct hash_cell, name_node);
351 md = hc->md;
352 dm_get(md);
353
354 if (keep_open_devices &&
355 dm_lock_for_deletion(md, mark_deferred, only_deferred)) {
356 dm_put(md);
357 dev_skipped++;
358 continue;
359 }
360
361 t = __hash_remove(hc);
362
363 up_write(sem: &_hash_lock);
364
365 if (t) {
366 dm_sync_table(md);
367 dm_table_destroy(t);
368 }
369 dm_ima_measure_on_device_remove(md, remove_all: true);
370 dm_put(md);
371 if (likely(keep_open_devices))
372 dm_destroy(md);
373 else
374 dm_destroy_immediate(md);
375
376 /*
377 * Some mapped devices may be using other mapped
378 * devices, so repeat until we make no further
379 * progress. If a new mapped device is created
380 * here it will also get removed.
381 */
382 goto retry;
383 }
384
385 up_write(sem: &_hash_lock);
386
387 if (dev_skipped)
388 DMWARN("remove_all left %d open device(s)", dev_skipped);
389}
390
391/*
392 * Set the uuid of a hash_cell that isn't already set.
393 */
394static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
395{
396 mutex_lock(lock: &dm_hash_cells_mutex);
397 hc->uuid = new_uuid;
398 mutex_unlock(lock: &dm_hash_cells_mutex);
399
400 __link_uuid(new_hc: hc);
401}
402
403/*
404 * Changes the name of a hash_cell and returns the old name for
405 * the caller to free.
406 */
407static char *__change_cell_name(struct hash_cell *hc, char *new_name)
408{
409 char *old_name;
410
411 /*
412 * Rename and move the name cell.
413 */
414 __unlink_name(hc);
415 old_name = hc->name;
416
417 mutex_lock(lock: &dm_hash_cells_mutex);
418 hc->name = new_name;
419 mutex_unlock(lock: &dm_hash_cells_mutex);
420
421 __link_name(new_hc: hc);
422
423 return old_name;
424}
425
426static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
427 const char *new)
428{
429 char *new_data, *old_name = NULL;
430 struct hash_cell *hc;
431 struct dm_table *table;
432 struct mapped_device *md;
433 unsigned int change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
434 int srcu_idx;
435
436 /*
437 * duplicate new.
438 */
439 new_data = kstrdup(s: new, GFP_KERNEL);
440 if (!new_data)
441 return ERR_PTR(error: -ENOMEM);
442
443 down_write(sem: &_hash_lock);
444
445 /*
446 * Is new free ?
447 */
448 if (change_uuid)
449 hc = __get_uuid_cell(str: new);
450 else
451 hc = __get_name_cell(str: new);
452
453 if (hc) {
454 DMERR("Unable to change %s on mapped device %s to one that already exists: %s",
455 change_uuid ? "uuid" : "name",
456 param->name, new);
457 dm_put(md: hc->md);
458 up_write(sem: &_hash_lock);
459 kfree(objp: new_data);
460 return ERR_PTR(error: -EBUSY);
461 }
462
463 /*
464 * Is there such a device as 'old' ?
465 */
466 hc = __get_name_cell(str: param->name);
467 if (!hc) {
468 DMERR("Unable to rename non-existent device, %s to %s%s",
469 param->name, change_uuid ? "uuid " : "", new);
470 up_write(sem: &_hash_lock);
471 kfree(objp: new_data);
472 return ERR_PTR(error: -ENXIO);
473 }
474
475 /*
476 * Does this device already have a uuid?
477 */
478 if (change_uuid && hc->uuid) {
479 DMERR("Unable to change uuid of mapped device %s to %s "
480 "because uuid is already set to %s",
481 param->name, new, hc->uuid);
482 dm_put(md: hc->md);
483 up_write(sem: &_hash_lock);
484 kfree(objp: new_data);
485 return ERR_PTR(error: -EINVAL);
486 }
487
488 if (change_uuid)
489 __set_cell_uuid(hc, new_uuid: new_data);
490 else
491 old_name = __change_cell_name(hc, new_name: new_data);
492
493 /*
494 * Wake up any dm event waiters.
495 */
496 table = dm_get_live_table(md: hc->md, srcu_idx: &srcu_idx);
497 if (table)
498 dm_table_event(t: table);
499 dm_put_live_table(md: hc->md, srcu_idx);
500
501 if (!dm_kobject_uevent(md: hc->md, action: KOBJ_CHANGE, cookie: param->event_nr, need_resize_uevent: false))
502 param->flags |= DM_UEVENT_GENERATED_FLAG;
503
504 md = hc->md;
505
506 dm_ima_measure_on_device_rename(md);
507
508 up_write(sem: &_hash_lock);
509 kfree(objp: old_name);
510
511 return md;
512}
513
514void dm_deferred_remove(void)
515{
516 dm_hash_remove_all(keep_open_devices: true, mark_deferred: false, only_deferred: true);
517}
518
519/*
520 *---------------------------------------------------------------
521 * Implementation of the ioctl commands
522 *---------------------------------------------------------------
523 */
524/*
525 * All the ioctl commands get dispatched to functions with this
526 * prototype.
527 */
528typedef int (*ioctl_fn)(struct file *filp, struct dm_ioctl *param, size_t param_size);
529
530static int remove_all(struct file *filp, struct dm_ioctl *param, size_t param_size)
531{
532 dm_hash_remove_all(keep_open_devices: true, mark_deferred: !!(param->flags & DM_DEFERRED_REMOVE), only_deferred: false);
533 param->data_size = 0;
534 return 0;
535}
536
537/*
538 * Round up the ptr to an 8-byte boundary.
539 */
540#define ALIGN_MASK 7
541static inline size_t align_val(size_t val)
542{
543 return (val + ALIGN_MASK) & ~ALIGN_MASK;
544}
545static inline void *align_ptr(void *ptr)
546{
547 return (void *)align_val(val: (size_t)ptr);
548}
549
550/*
551 * Retrieves the data payload buffer from an already allocated
552 * struct dm_ioctl.
553 */
554static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
555 size_t *len)
556{
557 param->data_start = align_ptr(ptr: param + 1) - (void *) param;
558
559 if (param->data_start < param_size)
560 *len = param_size - param->data_start;
561 else
562 *len = 0;
563
564 return ((void *) param) + param->data_start;
565}
566
567static bool filter_device(struct hash_cell *hc, const char *pfx_name, const char *pfx_uuid)
568{
569 const char *val;
570 size_t val_len, pfx_len;
571
572 val = hc->name;
573 val_len = strlen(val);
574 pfx_len = strnlen(pfx_name, DM_NAME_LEN);
575 if (pfx_len > val_len)
576 return false;
577 if (memcmp(val, pfx_name, pfx_len))
578 return false;
579
580 val = hc->uuid ? hc->uuid : "";
581 val_len = strlen(val);
582 pfx_len = strnlen(pfx_uuid, DM_UUID_LEN);
583 if (pfx_len > val_len)
584 return false;
585 if (memcmp(val, pfx_uuid, pfx_len))
586 return false;
587
588 return true;
589}
590
591static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_size)
592{
593 struct rb_node *n;
594 struct hash_cell *hc;
595 size_t len, needed = 0;
596 struct gendisk *disk;
597 struct dm_name_list *orig_nl, *nl, *old_nl = NULL;
598 uint32_t *event_nr;
599
600 down_write(sem: &_hash_lock);
601
602 /*
603 * Loop through all the devices working out how much
604 * space we need.
605 */
606 for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {
607 hc = container_of(n, struct hash_cell, name_node);
608 if (!filter_device(hc, pfx_name: param->name, pfx_uuid: param->uuid))
609 continue;
610 needed += align_val(offsetof(struct dm_name_list, name) + strlen(hc->name) + 1);
611 needed += align_val(val: sizeof(uint32_t) * 2);
612 if (param->flags & DM_UUID_FLAG && hc->uuid)
613 needed += align_val(val: strlen(hc->uuid) + 1);
614 }
615
616 /*
617 * Grab our output buffer.
618 */
619 nl = orig_nl = get_result_buffer(param, param_size, len: &len);
620 if (len < needed || len < sizeof(nl->dev)) {
621 param->flags |= DM_BUFFER_FULL_FLAG;
622 goto out;
623 }
624 param->data_size = param->data_start + needed;
625
626 nl->dev = 0; /* Flags no data */
627
628 /*
629 * Now loop through filling out the names.
630 */
631 for (n = rb_first(&name_rb_tree); n; n = rb_next(n)) {
632 void *uuid_ptr;
633
634 hc = container_of(n, struct hash_cell, name_node);
635 if (!filter_device(hc, pfx_name: param->name, pfx_uuid: param->uuid))
636 continue;
637 if (old_nl)
638 old_nl->next = (uint32_t) ((void *) nl -
639 (void *) old_nl);
640 disk = dm_disk(md: hc->md);
641 nl->dev = huge_encode_dev(dev: disk_devt(disk));
642 nl->next = 0;
643 strcpy(nl->name, hc->name);
644
645 old_nl = nl;
646 event_nr = align_ptr(ptr: nl->name + strlen(hc->name) + 1);
647 event_nr[0] = dm_get_event_nr(md: hc->md);
648 event_nr[1] = 0;
649 uuid_ptr = align_ptr(ptr: event_nr + 2);
650 if (param->flags & DM_UUID_FLAG) {
651 if (hc->uuid) {
652 event_nr[1] |= DM_NAME_LIST_FLAG_HAS_UUID;
653 strcpy(uuid_ptr, hc->uuid);
654 uuid_ptr = align_ptr(ptr: uuid_ptr + strlen(hc->uuid) + 1);
655 } else {
656 event_nr[1] |= DM_NAME_LIST_FLAG_DOESNT_HAVE_UUID;
657 }
658 }
659 nl = uuid_ptr;
660 }
661 /*
662 * If mismatch happens, security may be compromised due to buffer
663 * overflow, so it's better to crash.
664 */
665 BUG_ON((char *)nl - (char *)orig_nl != needed);
666
667 out:
668 up_write(sem: &_hash_lock);
669 return 0;
670}
671
672static void list_version_get_needed(struct target_type *tt, void *needed_param)
673{
674 size_t *needed = needed_param;
675
676 *needed += sizeof(struct dm_target_versions);
677 *needed += strlen(tt->name) + 1;
678 *needed += ALIGN_MASK;
679}
680
681static void list_version_get_info(struct target_type *tt, void *param)
682{
683 struct vers_iter *info = param;
684
685 /* Check space - it might have changed since the first iteration */
686 if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 > info->end) {
687 info->flags = DM_BUFFER_FULL_FLAG;
688 return;
689 }
690
691 if (info->old_vers)
692 info->old_vers->next = (uint32_t) ((void *)info->vers - (void *)info->old_vers);
693
694 info->vers->version[0] = tt->version[0];
695 info->vers->version[1] = tt->version[1];
696 info->vers->version[2] = tt->version[2];
697 info->vers->next = 0;
698 strcpy(info->vers->name, tt->name);
699
700 info->old_vers = info->vers;
701 info->vers = align_ptr(ptr: (void *)(info->vers + 1) + strlen(tt->name) + 1);
702}
703
704static int __list_versions(struct dm_ioctl *param, size_t param_size, const char *name)
705{
706 size_t len, needed = 0;
707 struct dm_target_versions *vers;
708 struct vers_iter iter_info;
709 struct target_type *tt = NULL;
710
711 if (name) {
712 tt = dm_get_target_type(name);
713 if (!tt)
714 return -EINVAL;
715 }
716
717 /*
718 * Loop through all the devices working out how much
719 * space we need.
720 */
721 if (!tt)
722 dm_target_iterate(iter_func: list_version_get_needed, param: &needed);
723 else
724 list_version_get_needed(tt, needed_param: &needed);
725
726 /*
727 * Grab our output buffer.
728 */
729 vers = get_result_buffer(param, param_size, len: &len);
730 if (len < needed) {
731 param->flags |= DM_BUFFER_FULL_FLAG;
732 goto out;
733 }
734 param->data_size = param->data_start + needed;
735
736 iter_info.param_size = param_size;
737 iter_info.old_vers = NULL;
738 iter_info.vers = vers;
739 iter_info.flags = 0;
740 iter_info.end = (char *)vers + needed;
741
742 /*
743 * Now loop through filling out the names & versions.
744 */
745 if (!tt)
746 dm_target_iterate(iter_func: list_version_get_info, param: &iter_info);
747 else
748 list_version_get_info(tt, param: &iter_info);
749 param->flags |= iter_info.flags;
750
751 out:
752 if (tt)
753 dm_put_target_type(tt);
754 return 0;
755}
756
757static int list_versions(struct file *filp, struct dm_ioctl *param, size_t param_size)
758{
759 return __list_versions(param, param_size, NULL);
760}
761
762static int get_target_version(struct file *filp, struct dm_ioctl *param, size_t param_size)
763{
764 return __list_versions(param, param_size, name: param->name);
765}
766
767static int check_name(const char *name)
768{
769 if (strchr(name, '/')) {
770 DMERR("device name cannot contain '/'");
771 return -EINVAL;
772 }
773
774 if (strcmp(name, DM_CONTROL_NODE) == 0 ||
775 strcmp(name, ".") == 0 ||
776 strcmp(name, "..") == 0) {
777 DMERR("device name cannot be \"%s\", \".\", or \"..\"", DM_CONTROL_NODE);
778 return -EINVAL;
779 }
780
781 return 0;
782}
783
784/*
785 * On successful return, the caller must not attempt to acquire
786 * _hash_lock without first calling dm_put_live_table, because dm_table_destroy
787 * waits for this dm_put_live_table and could be called under this lock.
788 */
789static struct dm_table *dm_get_inactive_table(struct mapped_device *md, int *srcu_idx)
790{
791 struct hash_cell *hc;
792 struct dm_table *table = NULL;
793
794 /* increment rcu count, we don't care about the table pointer */
795 dm_get_live_table(md, srcu_idx);
796
797 down_read(sem: &_hash_lock);
798 hc = dm_get_mdptr(md);
799 if (!hc) {
800 DMERR("device has been removed from the dev hash table.");
801 goto out;
802 }
803
804 table = hc->new_map;
805
806out:
807 up_read(sem: &_hash_lock);
808
809 return table;
810}
811
812static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
813 struct dm_ioctl *param,
814 int *srcu_idx)
815{
816 return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
817 dm_get_inactive_table(md, srcu_idx) : dm_get_live_table(md, srcu_idx);
818}
819
820/*
821 * Fills in a dm_ioctl structure, ready for sending back to
822 * userland.
823 */
824static void __dev_status(struct mapped_device *md, struct dm_ioctl *param)
825{
826 struct gendisk *disk = dm_disk(md);
827 struct dm_table *table;
828 int srcu_idx;
829
830 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
831 DM_ACTIVE_PRESENT_FLAG | DM_INTERNAL_SUSPEND_FLAG);
832
833 if (dm_suspended_md(md))
834 param->flags |= DM_SUSPEND_FLAG;
835
836 if (dm_suspended_internally_md(md))
837 param->flags |= DM_INTERNAL_SUSPEND_FLAG;
838
839 if (dm_test_deferred_remove_flag(md))
840 param->flags |= DM_DEFERRED_REMOVE;
841
842 param->dev = huge_encode_dev(dev: disk_devt(disk));
843
844 /*
845 * Yes, this will be out of date by the time it gets back
846 * to userland, but it is still very useful for
847 * debugging.
848 */
849 param->open_count = dm_open_count(md);
850
851 param->event_nr = dm_get_event_nr(md);
852 param->target_count = 0;
853
854 table = dm_get_live_table(md, srcu_idx: &srcu_idx);
855 if (table) {
856 if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
857 if (get_disk_ro(disk))
858 param->flags |= DM_READONLY_FLAG;
859 param->target_count = table->num_targets;
860 }
861
862 param->flags |= DM_ACTIVE_PRESENT_FLAG;
863 }
864 dm_put_live_table(md, srcu_idx);
865
866 if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
867 int srcu_idx;
868
869 table = dm_get_inactive_table(md, srcu_idx: &srcu_idx);
870 if (table) {
871 if (!(dm_table_get_mode(t: table) & BLK_OPEN_WRITE))
872 param->flags |= DM_READONLY_FLAG;
873 param->target_count = table->num_targets;
874 }
875 dm_put_live_table(md, srcu_idx);
876 }
877}
878
879static int dev_create(struct file *filp, struct dm_ioctl *param, size_t param_size)
880{
881 int r, m = DM_ANY_MINOR;
882 struct mapped_device *md;
883
884 r = check_name(name: param->name);
885 if (r)
886 return r;
887
888 if (param->flags & DM_PERSISTENT_DEV_FLAG)
889 m = MINOR(huge_decode_dev(param->dev));
890
891 r = dm_create(minor: m, md: &md);
892 if (r)
893 return r;
894
895 r = dm_hash_insert(name: param->name, uuid: *param->uuid ? param->uuid : NULL, md);
896 if (r) {
897 dm_put(md);
898 dm_destroy(md);
899 return r;
900 }
901
902 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
903
904 __dev_status(md, param);
905
906 dm_put(md);
907
908 return 0;
909}
910
911/*
912 * Always use UUID for lookups if it's present, otherwise use name or dev.
913 */
914static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
915{
916 struct hash_cell *hc = NULL;
917
918 if (*param->uuid) {
919 if (*param->name || param->dev) {
920 DMERR("Invalid ioctl structure: uuid %s, name %s, dev %llx",
921 param->uuid, param->name, (unsigned long long)param->dev);
922 return NULL;
923 }
924
925 hc = __get_uuid_cell(str: param->uuid);
926 if (!hc)
927 return NULL;
928 } else if (*param->name) {
929 if (param->dev) {
930 DMERR("Invalid ioctl structure: name %s, dev %llx",
931 param->name, (unsigned long long)param->dev);
932 return NULL;
933 }
934
935 hc = __get_name_cell(str: param->name);
936 if (!hc)
937 return NULL;
938 } else if (param->dev) {
939 hc = __get_dev_cell(dev: param->dev);
940 if (!hc)
941 return NULL;
942 } else
943 return NULL;
944
945 /*
946 * Sneakily write in both the name and the uuid
947 * while we have the cell.
948 */
949 strscpy(param->name, hc->name, sizeof(param->name));
950 if (hc->uuid)
951 strscpy(param->uuid, hc->uuid, sizeof(param->uuid));
952 else
953 param->uuid[0] = '\0';
954
955 if (hc->new_map)
956 param->flags |= DM_INACTIVE_PRESENT_FLAG;
957 else
958 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
959
960 return hc;
961}
962
963static struct mapped_device *find_device(struct dm_ioctl *param)
964{
965 struct hash_cell *hc;
966 struct mapped_device *md = NULL;
967
968 down_read(sem: &_hash_lock);
969 hc = __find_device_hash_cell(param);
970 if (hc)
971 md = hc->md;
972 up_read(sem: &_hash_lock);
973
974 return md;
975}
976
977static int dev_remove(struct file *filp, struct dm_ioctl *param, size_t param_size)
978{
979 struct hash_cell *hc;
980 struct mapped_device *md;
981 int r;
982 struct dm_table *t;
983
984 down_write(sem: &_hash_lock);
985 hc = __find_device_hash_cell(param);
986
987 if (!hc) {
988 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
989 up_write(sem: &_hash_lock);
990 return -ENXIO;
991 }
992
993 md = hc->md;
994
995 /*
996 * Ensure the device is not open and nothing further can open it.
997 */
998 r = dm_lock_for_deletion(md, mark_deferred: !!(param->flags & DM_DEFERRED_REMOVE), only_deferred: false);
999 if (r) {
1000 if (r == -EBUSY && param->flags & DM_DEFERRED_REMOVE) {
1001 up_write(sem: &_hash_lock);
1002 dm_put(md);
1003 return 0;
1004 }
1005 DMDEBUG_LIMIT("unable to remove open device %s", hc->name);
1006 up_write(sem: &_hash_lock);
1007 dm_put(md);
1008 return r;
1009 }
1010
1011 t = __hash_remove(hc);
1012 up_write(sem: &_hash_lock);
1013
1014 if (t) {
1015 dm_sync_table(md);
1016 dm_table_destroy(t);
1017 }
1018
1019 param->flags &= ~DM_DEFERRED_REMOVE;
1020
1021 dm_ima_measure_on_device_remove(md, remove_all: false);
1022
1023 if (!dm_kobject_uevent(md, action: KOBJ_REMOVE, cookie: param->event_nr, need_resize_uevent: false))
1024 param->flags |= DM_UEVENT_GENERATED_FLAG;
1025
1026 dm_put(md);
1027 dm_destroy(md);
1028 return 0;
1029}
1030
1031/*
1032 * Check a string doesn't overrun the chunk of
1033 * memory we copied from userland.
1034 */
1035static int invalid_str(char *str, void *end)
1036{
1037 while ((void *) str < end)
1038 if (!*str++)
1039 return 0;
1040
1041 return -EINVAL;
1042}
1043
1044static int dev_rename(struct file *filp, struct dm_ioctl *param, size_t param_size)
1045{
1046 int r;
1047 char *new_data = (char *) param + param->data_start;
1048 struct mapped_device *md;
1049 unsigned int change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
1050
1051 if (new_data < param->data ||
1052 invalid_str(str: new_data, end: (void *) param + param_size) || !*new_data ||
1053 strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
1054 DMERR("Invalid new mapped device name or uuid string supplied.");
1055 return -EINVAL;
1056 }
1057
1058 if (!change_uuid) {
1059 r = check_name(name: new_data);
1060 if (r)
1061 return r;
1062 }
1063
1064 md = dm_hash_rename(param, new: new_data);
1065 if (IS_ERR(ptr: md))
1066 return PTR_ERR(ptr: md);
1067
1068 __dev_status(md, param);
1069 dm_put(md);
1070
1071 return 0;
1072}
1073
1074static int dev_set_geometry(struct file *filp, struct dm_ioctl *param, size_t param_size)
1075{
1076 int r = -EINVAL, x;
1077 struct mapped_device *md;
1078 struct hd_geometry geometry;
1079 unsigned long indata[4];
1080 char *geostr = (char *) param + param->data_start;
1081 char dummy;
1082
1083 md = find_device(param);
1084 if (!md)
1085 return -ENXIO;
1086
1087 if (geostr < param->data ||
1088 invalid_str(str: geostr, end: (void *) param + param_size)) {
1089 DMERR("Invalid geometry supplied.");
1090 goto out;
1091 }
1092
1093 x = sscanf(geostr, "%lu %lu %lu %lu%c", indata,
1094 indata + 1, indata + 2, indata + 3, &dummy);
1095
1096 if (x != 4) {
1097 DMERR("Unable to interpret geometry settings.");
1098 goto out;
1099 }
1100
1101 if (indata[0] > 65535 || indata[1] > 255 || indata[2] > 255) {
1102 DMERR("Geometry exceeds range limits.");
1103 goto out;
1104 }
1105
1106 geometry.cylinders = indata[0];
1107 geometry.heads = indata[1];
1108 geometry.sectors = indata[2];
1109 geometry.start = indata[3];
1110
1111 r = dm_set_geometry(md, geo: &geometry);
1112
1113 param->data_size = 0;
1114
1115out:
1116 dm_put(md);
1117 return r;
1118}
1119
1120static int do_suspend(struct dm_ioctl *param)
1121{
1122 int r = 0;
1123 unsigned int suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
1124 struct mapped_device *md;
1125
1126 md = find_device(param);
1127 if (!md)
1128 return -ENXIO;
1129
1130 if (param->flags & DM_SKIP_LOCKFS_FLAG)
1131 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
1132 if (param->flags & DM_NOFLUSH_FLAG)
1133 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
1134
1135 if (!dm_suspended_md(md)) {
1136 r = dm_suspend(md, suspend_flags);
1137 if (r)
1138 goto out;
1139 }
1140
1141 __dev_status(md, param);
1142
1143out:
1144 dm_put(md);
1145
1146 return r;
1147}
1148
1149static int do_resume(struct dm_ioctl *param)
1150{
1151 int r = 0;
1152 unsigned int suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
1153 struct hash_cell *hc;
1154 struct mapped_device *md;
1155 struct dm_table *new_map, *old_map = NULL;
1156 bool need_resize_uevent = false;
1157
1158 down_write(sem: &_hash_lock);
1159
1160 hc = __find_device_hash_cell(param);
1161 if (!hc) {
1162 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1163 up_write(sem: &_hash_lock);
1164 return -ENXIO;
1165 }
1166
1167 md = hc->md;
1168
1169 new_map = hc->new_map;
1170 hc->new_map = NULL;
1171 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1172
1173 up_write(sem: &_hash_lock);
1174
1175 /* Do we need to load a new map ? */
1176 if (new_map) {
1177 sector_t old_size, new_size;
1178
1179 /* Suspend if it isn't already suspended */
1180 if (param->flags & DM_SKIP_LOCKFS_FLAG)
1181 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
1182 if (param->flags & DM_NOFLUSH_FLAG)
1183 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
1184 if (!dm_suspended_md(md)) {
1185 r = dm_suspend(md, suspend_flags);
1186 if (r) {
1187 down_write(sem: &_hash_lock);
1188 hc = dm_get_mdptr(md);
1189 if (hc && !hc->new_map) {
1190 hc->new_map = new_map;
1191 new_map = NULL;
1192 } else {
1193 r = -ENXIO;
1194 }
1195 up_write(sem: &_hash_lock);
1196 if (new_map) {
1197 dm_sync_table(md);
1198 dm_table_destroy(t: new_map);
1199 }
1200 dm_put(md);
1201 return r;
1202 }
1203 }
1204
1205 old_size = dm_get_size(md);
1206 old_map = dm_swap_table(md, t: new_map);
1207 if (IS_ERR(ptr: old_map)) {
1208 dm_sync_table(md);
1209 dm_table_destroy(t: new_map);
1210 dm_put(md);
1211 return PTR_ERR(ptr: old_map);
1212 }
1213 new_size = dm_get_size(md);
1214 if (old_size && new_size && old_size != new_size)
1215 need_resize_uevent = true;
1216
1217 if (dm_table_get_mode(t: new_map) & BLK_OPEN_WRITE)
1218 set_disk_ro(disk: dm_disk(md), read_only: 0);
1219 else
1220 set_disk_ro(disk: dm_disk(md), read_only: 1);
1221 }
1222
1223 if (dm_suspended_md(md)) {
1224 r = dm_resume(md);
1225 if (!r) {
1226 dm_ima_measure_on_device_resume(md, swap: new_map ? true : false);
1227
1228 if (!dm_kobject_uevent(md, action: KOBJ_CHANGE, cookie: param->event_nr, need_resize_uevent))
1229 param->flags |= DM_UEVENT_GENERATED_FLAG;
1230 }
1231 }
1232
1233 /*
1234 * Since dm_swap_table synchronizes RCU, nobody should be in
1235 * read-side critical section already.
1236 */
1237 if (old_map)
1238 dm_table_destroy(t: old_map);
1239
1240 if (!r)
1241 __dev_status(md, param);
1242
1243 dm_put(md);
1244 return r;
1245}
1246
1247/*
1248 * Set or unset the suspension state of a device.
1249 * If the device already is in the requested state we just return its status.
1250 */
1251static int dev_suspend(struct file *filp, struct dm_ioctl *param, size_t param_size)
1252{
1253 if (param->flags & DM_SUSPEND_FLAG)
1254 return do_suspend(param);
1255
1256 return do_resume(param);
1257}
1258
1259/*
1260 * Copies device info back to user space, used by
1261 * the create and info ioctls.
1262 */
1263static int dev_status(struct file *filp, struct dm_ioctl *param, size_t param_size)
1264{
1265 struct mapped_device *md;
1266
1267 md = find_device(param);
1268 if (!md)
1269 return -ENXIO;
1270
1271 __dev_status(md, param);
1272 dm_put(md);
1273
1274 return 0;
1275}
1276
1277/*
1278 * Build up the status struct for each target
1279 */
1280static void retrieve_status(struct dm_table *table,
1281 struct dm_ioctl *param, size_t param_size)
1282{
1283 unsigned int i, num_targets;
1284 struct dm_target_spec *spec;
1285 char *outbuf, *outptr;
1286 status_type_t type;
1287 size_t remaining, len, used = 0;
1288 unsigned int status_flags = 0;
1289
1290 outptr = outbuf = get_result_buffer(param, param_size, len: &len);
1291
1292 if (param->flags & DM_STATUS_TABLE_FLAG)
1293 type = STATUSTYPE_TABLE;
1294 else if (param->flags & DM_IMA_MEASUREMENT_FLAG)
1295 type = STATUSTYPE_IMA;
1296 else
1297 type = STATUSTYPE_INFO;
1298
1299 /* Get all the target info */
1300 num_targets = table->num_targets;
1301 for (i = 0; i < num_targets; i++) {
1302 struct dm_target *ti = dm_table_get_target(t: table, index: i);
1303 size_t l;
1304
1305 remaining = len - (outptr - outbuf);
1306 if (remaining <= sizeof(struct dm_target_spec)) {
1307 param->flags |= DM_BUFFER_FULL_FLAG;
1308 break;
1309 }
1310
1311 spec = (struct dm_target_spec *) outptr;
1312
1313 spec->status = 0;
1314 spec->sector_start = ti->begin;
1315 spec->length = ti->len;
1316 strscpy_pad(spec->target_type, ti->type->name,
1317 sizeof(spec->target_type));
1318
1319 outptr += sizeof(struct dm_target_spec);
1320 remaining = len - (outptr - outbuf);
1321 if (remaining <= 0) {
1322 param->flags |= DM_BUFFER_FULL_FLAG;
1323 break;
1324 }
1325
1326 /* Get the status/table string from the target driver */
1327 if (ti->type->status) {
1328 if (param->flags & DM_NOFLUSH_FLAG)
1329 status_flags |= DM_STATUS_NOFLUSH_FLAG;
1330 ti->type->status(ti, type, status_flags, outptr, remaining);
1331 } else
1332 outptr[0] = '\0';
1333
1334 l = strlen(outptr) + 1;
1335 if (l == remaining) {
1336 param->flags |= DM_BUFFER_FULL_FLAG;
1337 break;
1338 }
1339
1340 outptr += l;
1341 used = param->data_start + (outptr - outbuf);
1342
1343 outptr = align_ptr(ptr: outptr);
1344 spec->next = outptr - outbuf;
1345 }
1346
1347 if (used)
1348 param->data_size = used;
1349
1350 param->target_count = num_targets;
1351}
1352
1353/*
1354 * Wait for a device to report an event
1355 */
1356static int dev_wait(struct file *filp, struct dm_ioctl *param, size_t param_size)
1357{
1358 int r = 0;
1359 struct mapped_device *md;
1360 struct dm_table *table;
1361 int srcu_idx;
1362
1363 md = find_device(param);
1364 if (!md)
1365 return -ENXIO;
1366
1367 /*
1368 * Wait for a notification event
1369 */
1370 if (dm_wait_event(md, event_nr: param->event_nr)) {
1371 r = -ERESTARTSYS;
1372 goto out;
1373 }
1374
1375 /*
1376 * The userland program is going to want to know what
1377 * changed to trigger the event, so we may as well tell
1378 * him and save an ioctl.
1379 */
1380 __dev_status(md, param);
1381
1382 table = dm_get_live_or_inactive_table(md, param, srcu_idx: &srcu_idx);
1383 if (table)
1384 retrieve_status(table, param, param_size);
1385 dm_put_live_table(md, srcu_idx);
1386
1387out:
1388 dm_put(md);
1389
1390 return r;
1391}
1392
1393/*
1394 * Remember the global event number and make it possible to poll
1395 * for further events.
1396 */
1397static int dev_arm_poll(struct file *filp, struct dm_ioctl *param, size_t param_size)
1398{
1399 struct dm_file *priv = filp->private_data;
1400
1401 priv->global_event_nr = atomic_read(v: &dm_global_event_nr);
1402
1403 return 0;
1404}
1405
1406static inline blk_mode_t get_mode(struct dm_ioctl *param)
1407{
1408 blk_mode_t mode = BLK_OPEN_READ | BLK_OPEN_WRITE;
1409
1410 if (param->flags & DM_READONLY_FLAG)
1411 mode = BLK_OPEN_READ;
1412
1413 return mode;
1414}
1415
1416static int next_target(struct dm_target_spec *last, uint32_t next, const char *end,
1417 struct dm_target_spec **spec, char **target_params)
1418{
1419 static_assert(__alignof__(struct dm_target_spec) <= 8,
1420 "struct dm_target_spec must not require more than 8-byte alignment");
1421
1422 /*
1423 * Number of bytes remaining, starting with last. This is always
1424 * sizeof(struct dm_target_spec) or more, as otherwise *last was
1425 * out of bounds already.
1426 */
1427 size_t remaining = end - (char *)last;
1428
1429 /*
1430 * There must be room for both the next target spec and the
1431 * NUL-terminator of the target itself.
1432 */
1433 if (remaining - sizeof(struct dm_target_spec) <= next) {
1434 DMERR("Target spec extends beyond end of parameters");
1435 return -EINVAL;
1436 }
1437
1438 if (next % __alignof__(struct dm_target_spec)) {
1439 DMERR("Next dm_target_spec (offset %u) is not %zu-byte aligned",
1440 next, __alignof__(struct dm_target_spec));
1441 return -EINVAL;
1442 }
1443
1444 *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1445 *target_params = (char *) (*spec + 1);
1446
1447 return 0;
1448}
1449
1450static int populate_table(struct dm_table *table,
1451 struct dm_ioctl *param, size_t param_size)
1452{
1453 int r;
1454 unsigned int i = 0;
1455 struct dm_target_spec *spec = (struct dm_target_spec *) param;
1456 uint32_t next = param->data_start;
1457 const char *const end = (const char *) param + param_size;
1458 char *target_params;
1459 size_t min_size = sizeof(struct dm_ioctl);
1460
1461 if (!param->target_count) {
1462 DMERR("%s: no targets specified", __func__);
1463 return -EINVAL;
1464 }
1465
1466 for (i = 0; i < param->target_count; i++) {
1467 const char *nul_terminator;
1468
1469 if (next < min_size) {
1470 DMERR("%s: next target spec (offset %u) overlaps %s",
1471 __func__, next, i ? "previous target" : "'struct dm_ioctl'");
1472 return -EINVAL;
1473 }
1474
1475 r = next_target(last: spec, next, end, spec: &spec, target_params: &target_params);
1476 if (r) {
1477 DMERR("unable to find target");
1478 return r;
1479 }
1480
1481 nul_terminator = memchr(target_params, 0, (size_t)(end - target_params));
1482 if (nul_terminator == NULL) {
1483 DMERR("%s: target parameters not NUL-terminated", __func__);
1484 return -EINVAL;
1485 }
1486
1487 /* Add 1 for NUL terminator */
1488 min_size = (size_t)(nul_terminator - (const char *)spec) + 1;
1489
1490 r = dm_table_add_target(t: table, type: spec->target_type,
1491 start: (sector_t) spec->sector_start,
1492 len: (sector_t) spec->length,
1493 params: target_params);
1494 if (r) {
1495 DMERR("error adding target to table");
1496 return r;
1497 }
1498
1499 next = spec->next;
1500 }
1501
1502 return dm_table_complete(t: table);
1503}
1504
1505static bool is_valid_type(enum dm_queue_mode cur, enum dm_queue_mode new)
1506{
1507 if (cur == new ||
1508 (cur == DM_TYPE_BIO_BASED && new == DM_TYPE_DAX_BIO_BASED))
1509 return true;
1510
1511 return false;
1512}
1513
1514static int table_load(struct file *filp, struct dm_ioctl *param, size_t param_size)
1515{
1516 int r;
1517 struct hash_cell *hc;
1518 struct dm_table *t, *old_map = NULL;
1519 struct mapped_device *md;
1520 struct target_type *immutable_target_type;
1521
1522 md = find_device(param);
1523 if (!md)
1524 return -ENXIO;
1525
1526 r = dm_table_create(result: &t, mode: get_mode(param), num_targets: param->target_count, md);
1527 if (r)
1528 goto err;
1529
1530 /* Protect md->type and md->queue against concurrent table loads. */
1531 dm_lock_md_type(md);
1532 r = populate_table(table: t, param, param_size);
1533 if (r)
1534 goto err_unlock_md_type;
1535
1536 dm_ima_measure_on_table_load(table: t, status_flags: STATUSTYPE_IMA);
1537
1538 immutable_target_type = dm_get_immutable_target_type(md);
1539 if (immutable_target_type &&
1540 (immutable_target_type != dm_table_get_immutable_target_type(t)) &&
1541 !dm_table_get_wildcard_target(t)) {
1542 DMERR("can't replace immutable target type %s",
1543 immutable_target_type->name);
1544 r = -EINVAL;
1545 goto err_unlock_md_type;
1546 }
1547
1548 if (dm_get_md_type(md) == DM_TYPE_NONE) {
1549 /* setup md->queue to reflect md's type (may block) */
1550 r = dm_setup_md_queue(md, t);
1551 if (r) {
1552 DMERR("unable to set up device queue for new table.");
1553 goto err_unlock_md_type;
1554 }
1555 } else if (!is_valid_type(cur: dm_get_md_type(md), new: dm_table_get_type(t))) {
1556 DMERR("can't change device type (old=%u vs new=%u) after initial table load.",
1557 dm_get_md_type(md), dm_table_get_type(t));
1558 r = -EINVAL;
1559 goto err_unlock_md_type;
1560 }
1561
1562 dm_unlock_md_type(md);
1563
1564 /* stage inactive table */
1565 down_write(sem: &_hash_lock);
1566 hc = dm_get_mdptr(md);
1567 if (!hc) {
1568 DMERR("device has been removed from the dev hash table.");
1569 up_write(sem: &_hash_lock);
1570 r = -ENXIO;
1571 goto err_destroy_table;
1572 }
1573
1574 if (hc->new_map)
1575 old_map = hc->new_map;
1576 hc->new_map = t;
1577 up_write(sem: &_hash_lock);
1578
1579 param->flags |= DM_INACTIVE_PRESENT_FLAG;
1580 __dev_status(md, param);
1581
1582 if (old_map) {
1583 dm_sync_table(md);
1584 dm_table_destroy(t: old_map);
1585 }
1586
1587 dm_put(md);
1588
1589 return 0;
1590
1591err_unlock_md_type:
1592 dm_unlock_md_type(md);
1593err_destroy_table:
1594 dm_table_destroy(t);
1595err:
1596 dm_put(md);
1597
1598 return r;
1599}
1600
1601static int table_clear(struct file *filp, struct dm_ioctl *param, size_t param_size)
1602{
1603 struct hash_cell *hc;
1604 struct mapped_device *md;
1605 struct dm_table *old_map = NULL;
1606 bool has_new_map = false;
1607
1608 down_write(sem: &_hash_lock);
1609
1610 hc = __find_device_hash_cell(param);
1611 if (!hc) {
1612 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1613 up_write(sem: &_hash_lock);
1614 return -ENXIO;
1615 }
1616
1617 if (hc->new_map) {
1618 old_map = hc->new_map;
1619 hc->new_map = NULL;
1620 has_new_map = true;
1621 }
1622
1623 md = hc->md;
1624 up_write(sem: &_hash_lock);
1625
1626 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1627 __dev_status(md, param);
1628
1629 if (old_map) {
1630 dm_sync_table(md);
1631 dm_table_destroy(t: old_map);
1632 }
1633 dm_ima_measure_on_table_clear(md, new_map: has_new_map);
1634 dm_put(md);
1635
1636 return 0;
1637}
1638
1639/*
1640 * Retrieves a list of devices used by a particular dm device.
1641 */
1642static void retrieve_deps(struct dm_table *table,
1643 struct dm_ioctl *param, size_t param_size)
1644{
1645 unsigned int count = 0;
1646 struct list_head *tmp;
1647 size_t len, needed;
1648 struct dm_dev_internal *dd;
1649 struct dm_target_deps *deps;
1650
1651 down_read(sem: &table->devices_lock);
1652
1653 deps = get_result_buffer(param, param_size, len: &len);
1654
1655 /*
1656 * Count the devices.
1657 */
1658 list_for_each(tmp, dm_table_get_devices(table))
1659 count++;
1660
1661 /*
1662 * Check we have enough space.
1663 */
1664 needed = struct_size(deps, dev, count);
1665 if (len < needed) {
1666 param->flags |= DM_BUFFER_FULL_FLAG;
1667 goto out;
1668 }
1669
1670 /*
1671 * Fill in the devices.
1672 */
1673 deps->count = count;
1674 count = 0;
1675 list_for_each_entry(dd, dm_table_get_devices(table), list)
1676 deps->dev[count++] = huge_encode_dev(dev: dd->dm_dev->bdev->bd_dev);
1677
1678 param->data_size = param->data_start + needed;
1679
1680out:
1681 up_read(sem: &table->devices_lock);
1682}
1683
1684static int table_deps(struct file *filp, struct dm_ioctl *param, size_t param_size)
1685{
1686 struct mapped_device *md;
1687 struct dm_table *table;
1688 int srcu_idx;
1689
1690 md = find_device(param);
1691 if (!md)
1692 return -ENXIO;
1693
1694 __dev_status(md, param);
1695
1696 table = dm_get_live_or_inactive_table(md, param, srcu_idx: &srcu_idx);
1697 if (table)
1698 retrieve_deps(table, param, param_size);
1699 dm_put_live_table(md, srcu_idx);
1700
1701 dm_put(md);
1702
1703 return 0;
1704}
1705
1706/*
1707 * Return the status of a device as a text string for each
1708 * target.
1709 */
1710static int table_status(struct file *filp, struct dm_ioctl *param, size_t param_size)
1711{
1712 struct mapped_device *md;
1713 struct dm_table *table;
1714 int srcu_idx;
1715
1716 md = find_device(param);
1717 if (!md)
1718 return -ENXIO;
1719
1720 __dev_status(md, param);
1721
1722 table = dm_get_live_or_inactive_table(md, param, srcu_idx: &srcu_idx);
1723 if (table)
1724 retrieve_status(table, param, param_size);
1725 dm_put_live_table(md, srcu_idx);
1726
1727 dm_put(md);
1728
1729 return 0;
1730}
1731
1732/*
1733 * Process device-mapper dependent messages. Messages prefixed with '@'
1734 * are processed by the DM core. All others are delivered to the target.
1735 * Returns a number <= 1 if message was processed by device mapper.
1736 * Returns 2 if message should be delivered to the target.
1737 */
1738static int message_for_md(struct mapped_device *md, unsigned int argc, char **argv,
1739 char *result, unsigned int maxlen)
1740{
1741 int r;
1742
1743 if (**argv != '@')
1744 return 2; /* no '@' prefix, deliver to target */
1745
1746 if (!strcasecmp(s1: argv[0], s2: "@cancel_deferred_remove")) {
1747 if (argc != 1) {
1748 DMERR("Invalid arguments for @cancel_deferred_remove");
1749 return -EINVAL;
1750 }
1751 return dm_cancel_deferred_remove(md);
1752 }
1753
1754 r = dm_stats_message(md, argc, argv, result, maxlen);
1755 if (r < 2)
1756 return r;
1757
1758 DMERR("Unsupported message sent to DM core: %s", argv[0]);
1759 return -EINVAL;
1760}
1761
1762/*
1763 * Pass a message to the target that's at the supplied device offset.
1764 */
1765static int target_message(struct file *filp, struct dm_ioctl *param, size_t param_size)
1766{
1767 int r, argc;
1768 char **argv;
1769 struct mapped_device *md;
1770 struct dm_table *table;
1771 struct dm_target *ti;
1772 struct dm_target_msg *tmsg = (void *) param + param->data_start;
1773 size_t maxlen;
1774 char *result = get_result_buffer(param, param_size, len: &maxlen);
1775 int srcu_idx;
1776
1777 md = find_device(param);
1778 if (!md)
1779 return -ENXIO;
1780
1781 if (tmsg < (struct dm_target_msg *) param->data ||
1782 invalid_str(str: tmsg->message, end: (void *) param + param_size)) {
1783 DMERR("Invalid target message parameters.");
1784 r = -EINVAL;
1785 goto out;
1786 }
1787
1788 r = dm_split_args(argc: &argc, argvp: &argv, input: tmsg->message);
1789 if (r) {
1790 DMERR("Failed to split target message parameters");
1791 goto out;
1792 }
1793
1794 if (!argc) {
1795 DMERR("Empty message received.");
1796 r = -EINVAL;
1797 goto out_argv;
1798 }
1799
1800 r = message_for_md(md, argc, argv, result, maxlen);
1801 if (r <= 1)
1802 goto out_argv;
1803
1804 table = dm_get_live_table(md, srcu_idx: &srcu_idx);
1805 if (!table)
1806 goto out_table;
1807
1808 if (dm_deleting_md(md)) {
1809 r = -ENXIO;
1810 goto out_table;
1811 }
1812
1813 ti = dm_table_find_target(t: table, sector: tmsg->sector);
1814 if (!ti) {
1815 DMERR("Target message sector outside device.");
1816 r = -EINVAL;
1817 } else if (ti->type->message)
1818 r = ti->type->message(ti, argc, argv, result, maxlen);
1819 else {
1820 DMERR("Target type does not support messages");
1821 r = -EINVAL;
1822 }
1823
1824 out_table:
1825 dm_put_live_table(md, srcu_idx);
1826 out_argv:
1827 kfree(objp: argv);
1828 out:
1829 if (r >= 0)
1830 __dev_status(md, param);
1831
1832 if (r == 1) {
1833 param->flags |= DM_DATA_OUT_FLAG;
1834 if (dm_message_test_buffer_overflow(result, maxlen))
1835 param->flags |= DM_BUFFER_FULL_FLAG;
1836 else
1837 param->data_size = param->data_start + strlen(result) + 1;
1838 r = 0;
1839 }
1840
1841 dm_put(md);
1842 return r;
1843}
1844
1845/*
1846 * The ioctl parameter block consists of two parts, a dm_ioctl struct
1847 * followed by a data buffer. This flag is set if the second part,
1848 * which has a variable size, is not used by the function processing
1849 * the ioctl.
1850 */
1851#define IOCTL_FLAGS_NO_PARAMS 1
1852#define IOCTL_FLAGS_ISSUE_GLOBAL_EVENT 2
1853
1854/*
1855 *---------------------------------------------------------------
1856 * Implementation of open/close/ioctl on the special char device.
1857 *---------------------------------------------------------------
1858 */
1859static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags)
1860{
1861 static const struct {
1862 int cmd;
1863 int flags;
1864 ioctl_fn fn;
1865 } _ioctls[] = {
1866 {DM_VERSION_CMD, 0, NULL}, /* version is dealt with elsewhere */
1867 {.cmd: DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, .fn: remove_all},
1868 {.cmd: DM_LIST_DEVICES_CMD, .flags: 0, .fn: list_devices},
1869
1870 {.cmd: DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, .fn: dev_create},
1871 {.cmd: DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, .fn: dev_remove},
1872 {.cmd: DM_DEV_RENAME_CMD, IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, .fn: dev_rename},
1873 {.cmd: DM_DEV_SUSPEND_CMD, IOCTL_FLAGS_NO_PARAMS, .fn: dev_suspend},
1874 {.cmd: DM_DEV_STATUS_CMD, IOCTL_FLAGS_NO_PARAMS, .fn: dev_status},
1875 {.cmd: DM_DEV_WAIT_CMD, .flags: 0, .fn: dev_wait},
1876
1877 {.cmd: DM_TABLE_LOAD_CMD, .flags: 0, .fn: table_load},
1878 {.cmd: DM_TABLE_CLEAR_CMD, IOCTL_FLAGS_NO_PARAMS, .fn: table_clear},
1879 {.cmd: DM_TABLE_DEPS_CMD, .flags: 0, .fn: table_deps},
1880 {.cmd: DM_TABLE_STATUS_CMD, .flags: 0, .fn: table_status},
1881
1882 {.cmd: DM_LIST_VERSIONS_CMD, .flags: 0, .fn: list_versions},
1883
1884 {.cmd: DM_TARGET_MSG_CMD, .flags: 0, .fn: target_message},
1885 {.cmd: DM_DEV_SET_GEOMETRY_CMD, .flags: 0, .fn: dev_set_geometry},
1886 {.cmd: DM_DEV_ARM_POLL_CMD, IOCTL_FLAGS_NO_PARAMS, .fn: dev_arm_poll},
1887 {.cmd: DM_GET_TARGET_VERSION_CMD, .flags: 0, .fn: get_target_version},
1888 {.cmd: DM_MPATH_PROBE_PATHS_CMD, .flags: 0, NULL}, /* block device ioctl */
1889 };
1890
1891 if (unlikely(cmd >= ARRAY_SIZE(_ioctls)))
1892 return NULL;
1893
1894 cmd = array_index_nospec(cmd, ARRAY_SIZE(_ioctls));
1895 *ioctl_flags = _ioctls[cmd].flags;
1896 return _ioctls[cmd].fn;
1897}
1898
1899/*
1900 * As well as checking the version compatibility this always
1901 * copies the kernel interface version out.
1902 */
1903static int check_version(unsigned int cmd, struct dm_ioctl __user *user,
1904 struct dm_ioctl *kernel_params)
1905{
1906 int r = 0;
1907
1908 /* Make certain version is first member of dm_ioctl struct */
1909 BUILD_BUG_ON(offsetof(struct dm_ioctl, version) != 0);
1910
1911 if (copy_from_user(to: kernel_params->version, from: user->version, n: sizeof(kernel_params->version)))
1912 return -EFAULT;
1913
1914 if ((kernel_params->version[0] != DM_VERSION_MAJOR) ||
1915 (kernel_params->version[1] > DM_VERSION_MINOR)) {
1916 DMERR_LIMIT("ioctl interface mismatch: kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1917 DM_VERSION_MAJOR, DM_VERSION_MINOR,
1918 DM_VERSION_PATCHLEVEL,
1919 kernel_params->version[0],
1920 kernel_params->version[1],
1921 kernel_params->version[2],
1922 cmd);
1923 r = -EINVAL;
1924 }
1925
1926 /*
1927 * Fill in the kernel version.
1928 */
1929 kernel_params->version[0] = DM_VERSION_MAJOR;
1930 kernel_params->version[1] = DM_VERSION_MINOR;
1931 kernel_params->version[2] = DM_VERSION_PATCHLEVEL;
1932 if (copy_to_user(to: user->version, from: kernel_params->version, n: sizeof(kernel_params->version)))
1933 return -EFAULT;
1934
1935 return r;
1936}
1937
1938#define DM_PARAMS_MALLOC 0x0001 /* Params allocated with kvmalloc() */
1939#define DM_WIPE_BUFFER 0x0010 /* Wipe input buffer before returning from ioctl */
1940
1941static void free_params(struct dm_ioctl *param, size_t param_size, int param_flags)
1942{
1943 if (param_flags & DM_WIPE_BUFFER)
1944 memset(s: param, c: 0, n: param_size);
1945
1946 if (param_flags & DM_PARAMS_MALLOC)
1947 kvfree(addr: param);
1948}
1949
1950static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel,
1951 int ioctl_flags, struct dm_ioctl **param, int *param_flags)
1952{
1953 struct dm_ioctl *dmi;
1954 int secure_data;
1955 const size_t minimum_data_size = offsetof(struct dm_ioctl, data);
1956
1957 /* check_version() already copied version from userspace, avoid TOCTOU */
1958 if (copy_from_user(to: (char *)param_kernel + sizeof(param_kernel->version),
1959 from: (char __user *)user + sizeof(param_kernel->version),
1960 n: minimum_data_size - sizeof(param_kernel->version)))
1961 return -EFAULT;
1962
1963 if (unlikely(param_kernel->data_size < minimum_data_size) ||
1964 unlikely(param_kernel->data_size > DM_MAX_TARGETS * DM_MAX_TARGET_PARAMS)) {
1965 DMERR_LIMIT("Invalid data size in the ioctl structure: %u",
1966 param_kernel->data_size);
1967 return -EINVAL;
1968 }
1969
1970 secure_data = param_kernel->flags & DM_SECURE_DATA_FLAG;
1971
1972 *param_flags = secure_data ? DM_WIPE_BUFFER : 0;
1973
1974 if (ioctl_flags & IOCTL_FLAGS_NO_PARAMS) {
1975 dmi = param_kernel;
1976 dmi->data_size = minimum_data_size;
1977 goto data_copied;
1978 }
1979
1980 /*
1981 * Use __GFP_HIGH to avoid low memory issues when a device is
1982 * suspended and the ioctl is needed to resume it.
1983 * Use kmalloc() rather than vmalloc() when we can.
1984 */
1985 dmi = NULL;
1986 dmi = kvmalloc(param_kernel->data_size, GFP_NOIO | __GFP_HIGH);
1987
1988 if (!dmi) {
1989 if (secure_data && clear_user(to: user, n: param_kernel->data_size))
1990 return -EFAULT;
1991 return -ENOMEM;
1992 }
1993
1994 *param_flags |= DM_PARAMS_MALLOC;
1995
1996 /* Copy from param_kernel (which was already copied from user) */
1997 memcpy(to: dmi, from: param_kernel, len: minimum_data_size);
1998
1999 if (copy_from_user(to: &dmi->data, from: (char __user *)user + minimum_data_size,
2000 n: param_kernel->data_size - minimum_data_size))
2001 goto bad;
2002data_copied:
2003 /* Wipe the user buffer so we do not return it to userspace */
2004 if (secure_data && clear_user(to: user, n: param_kernel->data_size))
2005 goto bad;
2006
2007 *param = dmi;
2008 return 0;
2009
2010bad:
2011 free_params(param: dmi, param_size: param_kernel->data_size, param_flags: *param_flags);
2012
2013 return -EFAULT;
2014}
2015
2016static int validate_params(uint cmd, struct dm_ioctl *param)
2017{
2018 /* Always clear this flag */
2019 param->flags &= ~DM_BUFFER_FULL_FLAG;
2020 param->flags &= ~DM_UEVENT_GENERATED_FLAG;
2021 param->flags &= ~DM_SECURE_DATA_FLAG;
2022 param->flags &= ~DM_DATA_OUT_FLAG;
2023
2024 /* Ignores parameters */
2025 if (cmd == DM_REMOVE_ALL_CMD ||
2026 cmd == DM_LIST_DEVICES_CMD ||
2027 cmd == DM_LIST_VERSIONS_CMD)
2028 return 0;
2029
2030 if (cmd == DM_DEV_CREATE_CMD) {
2031 if (!*param->name) {
2032 DMERR("name not supplied when creating device");
2033 return -EINVAL;
2034 }
2035 } else if (*param->uuid && *param->name) {
2036 DMERR("only supply one of name or uuid, cmd(%u)", cmd);
2037 return -EINVAL;
2038 }
2039
2040 /* Ensure strings are terminated */
2041 param->name[DM_NAME_LEN - 1] = '\0';
2042 param->uuid[DM_UUID_LEN - 1] = '\0';
2043
2044 return 0;
2045}
2046
2047static int ctl_ioctl(struct file *file, uint command, struct dm_ioctl __user *user)
2048{
2049 int r = 0;
2050 int ioctl_flags;
2051 int param_flags;
2052 unsigned int cmd;
2053 struct dm_ioctl *param;
2054 ioctl_fn fn = NULL;
2055 size_t input_param_size;
2056 struct dm_ioctl param_kernel;
2057
2058 /* only root can play with this */
2059 if (!capable(CAP_SYS_ADMIN))
2060 return -EACCES;
2061
2062 if (_IOC_TYPE(command) != DM_IOCTL)
2063 return -ENOTTY;
2064
2065 cmd = _IOC_NR(command);
2066
2067 /*
2068 * Check the interface version passed in. This also
2069 * writes out the kernel's interface version.
2070 */
2071 r = check_version(cmd, user, kernel_params: &param_kernel);
2072 if (r)
2073 return r;
2074
2075 /*
2076 * Nothing more to do for the version command.
2077 */
2078 if (cmd == DM_VERSION_CMD)
2079 return 0;
2080
2081 fn = lookup_ioctl(cmd, ioctl_flags: &ioctl_flags);
2082 if (!fn) {
2083 DMERR("dm_ctl_ioctl: unknown command 0x%x", command);
2084 return -ENOTTY;
2085 }
2086
2087 /*
2088 * Copy the parameters into kernel space.
2089 */
2090 r = copy_params(user, param_kernel: &param_kernel, ioctl_flags, param: &param, param_flags: &param_flags);
2091
2092 if (r)
2093 return r;
2094
2095 input_param_size = param->data_size;
2096 r = validate_params(cmd, param);
2097 if (r)
2098 goto out;
2099
2100 param->data_size = offsetof(struct dm_ioctl, data);
2101 r = fn(file, param, input_param_size);
2102
2103 if (unlikely(param->flags & DM_BUFFER_FULL_FLAG) &&
2104 unlikely(ioctl_flags & IOCTL_FLAGS_NO_PARAMS))
2105 DMERR("ioctl %d tried to output some data but has IOCTL_FLAGS_NO_PARAMS set", cmd);
2106
2107 if (!r && ioctl_flags & IOCTL_FLAGS_ISSUE_GLOBAL_EVENT)
2108 dm_issue_global_event();
2109
2110 /*
2111 * Copy the results back to userland.
2112 */
2113 if (!r && copy_to_user(to: user, from: param, n: param->data_size))
2114 r = -EFAULT;
2115
2116out:
2117 free_params(param, param_size: input_param_size, param_flags);
2118 return r;
2119}
2120
2121static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
2122{
2123 return (long)ctl_ioctl(file, command, user: (struct dm_ioctl __user *)u);
2124}
2125
2126#ifdef CONFIG_COMPAT
2127static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
2128{
2129 return (long)dm_ctl_ioctl(file, command, u: (ulong) compat_ptr(uptr: u));
2130}
2131#else
2132#define dm_compat_ctl_ioctl NULL
2133#endif
2134
2135static int dm_open(struct inode *inode, struct file *filp)
2136{
2137 int r;
2138 struct dm_file *priv;
2139
2140 r = nonseekable_open(inode, filp);
2141 if (unlikely(r))
2142 return r;
2143
2144 priv = filp->private_data = kmalloc(sizeof(struct dm_file), GFP_KERNEL);
2145 if (!priv)
2146 return -ENOMEM;
2147
2148 priv->global_event_nr = atomic_read(v: &dm_global_event_nr);
2149
2150 return 0;
2151}
2152
2153static int dm_release(struct inode *inode, struct file *filp)
2154{
2155 kfree(objp: filp->private_data);
2156 return 0;
2157}
2158
2159static __poll_t dm_poll(struct file *filp, poll_table *wait)
2160{
2161 struct dm_file *priv = filp->private_data;
2162 __poll_t mask = 0;
2163
2164 poll_wait(filp, wait_address: &dm_global_eventq, p: wait);
2165
2166 if ((int)(atomic_read(v: &dm_global_event_nr) - priv->global_event_nr) > 0)
2167 mask |= EPOLLIN;
2168
2169 return mask;
2170}
2171
2172static const struct file_operations _ctl_fops = {
2173 .open = dm_open,
2174 .release = dm_release,
2175 .poll = dm_poll,
2176 .unlocked_ioctl = dm_ctl_ioctl,
2177 .compat_ioctl = dm_compat_ctl_ioctl,
2178 .owner = THIS_MODULE,
2179 .llseek = noop_llseek,
2180};
2181
2182static struct miscdevice _dm_misc = {
2183 .minor = MAPPER_CTRL_MINOR,
2184 .name = DM_NAME,
2185 .nodename = DM_DIR "/" DM_CONTROL_NODE,
2186 .fops = &_ctl_fops
2187};
2188
2189MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
2190MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
2191
2192/*
2193 * Create misc character device and link to DM_DIR/control.
2194 */
2195int __init dm_interface_init(void)
2196{
2197 int r;
2198
2199 r = misc_register(misc: &_dm_misc);
2200 if (r) {
2201 DMERR("misc_register failed for control device");
2202 return r;
2203 }
2204
2205 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
2206 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
2207 DM_DRIVER_EMAIL);
2208 return 0;
2209}
2210
2211void dm_interface_exit(void)
2212{
2213 misc_deregister(misc: &_dm_misc);
2214 dm_hash_exit();
2215}
2216
2217/**
2218 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
2219 * @md: Pointer to mapped_device
2220 * @name: Buffer (size DM_NAME_LEN) for name
2221 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
2222 */
2223int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
2224{
2225 int r = 0;
2226 struct hash_cell *hc;
2227
2228 if (!md)
2229 return -ENXIO;
2230
2231 mutex_lock(lock: &dm_hash_cells_mutex);
2232 hc = dm_get_mdptr(md);
2233 if (!hc) {
2234 r = -ENXIO;
2235 goto out;
2236 }
2237
2238 if (name)
2239 strcpy(name, hc->name);
2240 if (uuid)
2241 strcpy(uuid, hc->uuid ? : "");
2242
2243out:
2244 mutex_unlock(lock: &dm_hash_cells_mutex);
2245
2246 return r;
2247}
2248EXPORT_SYMBOL_GPL(dm_copy_name_and_uuid);
2249
2250/**
2251 * dm_early_create - create a mapped device in early boot.
2252 *
2253 * @dmi: Contains main information of the device mapping to be created.
2254 * @spec_array: array of pointers to struct dm_target_spec. Describes the
2255 * mapping table of the device.
2256 * @target_params_array: array of strings with the parameters to a specific
2257 * target.
2258 *
2259 * Instead of having the struct dm_target_spec and the parameters for every
2260 * target embedded at the end of struct dm_ioctl (as performed in a normal
2261 * ioctl), pass them as arguments, so the caller doesn't need to serialize them.
2262 * The size of the spec_array and target_params_array is given by
2263 * @dmi->target_count.
2264 * This function is supposed to be called in early boot, so locking mechanisms
2265 * to protect against concurrent loads are not required.
2266 */
2267int __init dm_early_create(struct dm_ioctl *dmi,
2268 struct dm_target_spec **spec_array,
2269 char **target_params_array)
2270{
2271 int r, m = DM_ANY_MINOR;
2272 struct dm_table *t, *old_map;
2273 struct mapped_device *md;
2274 unsigned int i;
2275
2276 if (!dmi->target_count)
2277 return -EINVAL;
2278
2279 r = check_name(name: dmi->name);
2280 if (r)
2281 return r;
2282
2283 if (dmi->flags & DM_PERSISTENT_DEV_FLAG)
2284 m = MINOR(huge_decode_dev(dmi->dev));
2285
2286 /* alloc dm device */
2287 r = dm_create(minor: m, md: &md);
2288 if (r)
2289 return r;
2290
2291 /* hash insert */
2292 r = dm_hash_insert(name: dmi->name, uuid: *dmi->uuid ? dmi->uuid : NULL, md);
2293 if (r)
2294 goto err_destroy_dm;
2295
2296 /* alloc table */
2297 r = dm_table_create(result: &t, mode: get_mode(param: dmi), num_targets: dmi->target_count, md);
2298 if (r)
2299 goto err_hash_remove;
2300
2301 /* add targets */
2302 for (i = 0; i < dmi->target_count; i++) {
2303 r = dm_table_add_target(t, type: spec_array[i]->target_type,
2304 start: (sector_t) spec_array[i]->sector_start,
2305 len: (sector_t) spec_array[i]->length,
2306 params: target_params_array[i]);
2307 if (r) {
2308 DMERR("error adding target to table");
2309 goto err_destroy_table;
2310 }
2311 }
2312
2313 /* finish table */
2314 r = dm_table_complete(t);
2315 if (r)
2316 goto err_destroy_table;
2317
2318 /* setup md->queue to reflect md's type (may block) */
2319 r = dm_setup_md_queue(md, t);
2320 if (r) {
2321 DMERR("unable to set up device queue for new table.");
2322 goto err_destroy_table;
2323 }
2324
2325 /* Set new map */
2326 dm_suspend(md, suspend_flags: 0);
2327 old_map = dm_swap_table(md, t);
2328 if (IS_ERR(ptr: old_map)) {
2329 r = PTR_ERR(ptr: old_map);
2330 goto err_destroy_table;
2331 }
2332 set_disk_ro(disk: dm_disk(md), read_only: !!(dmi->flags & DM_READONLY_FLAG));
2333
2334 /* resume device */
2335 r = dm_resume(md);
2336 if (r)
2337 goto err_destroy_table;
2338
2339 DMINFO("%s (%s) is ready", md->disk->disk_name, dmi->name);
2340 dm_put(md);
2341 return 0;
2342
2343err_destroy_table:
2344 dm_table_destroy(t);
2345err_hash_remove:
2346 down_write(sem: &_hash_lock);
2347 (void) __hash_remove(hc: __get_name_cell(str: dmi->name));
2348 up_write(sem: &_hash_lock);
2349 /* release reference from __get_name_cell */
2350 dm_put(md);
2351err_destroy_dm:
2352 dm_put(md);
2353 dm_destroy(md);
2354 return r;
2355}
2356