2
* Copyright (C) 2003 Christophe Saout <christophe@saout.de>
3
* Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org>
4
* Copyright (C) 2006-2009 Red Hat, Inc. All rights reserved.
6
* This file is released under the GPL.
9
#include <linux/completion.h>
10
#include <linux/err.h>
11
#include <linux/module.h>
12
#include <linux/init.h>
13
#include <linux/kernel.h>
14
#include <linux/bio.h>
15
#include <linux/blkdev.h>
16
#include <linux/mempool.h>
17
#include <linux/slab.h>
18
#include <linux/crypto.h>
19
#include <linux/workqueue.h>
20
#include <linux/backing-dev.h>
21
#include <linux/percpu.h>
22
#include <linux/atomic.h>
23
#include <linux/scatterlist.h>
25
#include <asm/unaligned.h>
26
#include <crypto/hash.h>
27
#include <crypto/md5.h>
28
#include <crypto/algapi.h>
30
#include <linux/device-mapper.h>
32
#define DM_MSG_PREFIX "crypt"
35
* context holding the current state of a multi-part conversion
37
struct convert_context {
38
struct completion restart;
41
unsigned int offset_in;
42
unsigned int offset_out;
50
* per bio private data
53
struct dm_target *target;
55
struct work_struct work;
57
struct convert_context ctx;
62
struct dm_crypt_io *base_io;
65
struct dm_crypt_request {
66
struct convert_context *ctx;
67
struct scatterlist sg_in;
68
struct scatterlist sg_out;
74
struct crypt_iv_operations {
75
int (*ctr)(struct crypt_config *cc, struct dm_target *ti,
77
void (*dtr)(struct crypt_config *cc);
78
int (*init)(struct crypt_config *cc);
79
int (*wipe)(struct crypt_config *cc);
80
int (*generator)(struct crypt_config *cc, u8 *iv,
81
struct dm_crypt_request *dmreq);
82
int (*post)(struct crypt_config *cc, u8 *iv,
83
struct dm_crypt_request *dmreq);
86
struct iv_essiv_private {
87
struct crypto_hash *hash_tfm;
91
struct iv_benbi_private {
95
#define LMK_SEED_SIZE 64 /* hash + 0 */
96
struct iv_lmk_private {
97
struct crypto_shash *hash_tfm;
102
* Crypt: maps a linear range of a block device
103
* and encrypts / decrypts at the same time.
105
enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID };
108
* Duplicated per-CPU state for cipher.
111
struct ablkcipher_request *req;
112
/* ESSIV: struct crypto_cipher *essiv_tfm */
114
struct crypto_ablkcipher *tfms[0];
118
* The fields in here must be read only after initialization,
119
* changing state should be in crypt_cpu.
121
struct crypt_config {
126
* pool for per bio private data, crypto requests and
127
* encryption requeusts/buffer pages
131
mempool_t *page_pool;
134
struct workqueue_struct *io_queue;
135
struct workqueue_struct *crypt_queue;
140
struct crypt_iv_operations *iv_gen_ops;
142
struct iv_essiv_private essiv;
143
struct iv_benbi_private benbi;
144
struct iv_lmk_private lmk;
147
unsigned int iv_size;
150
* Duplicated per cpu state. Access through
151
* per_cpu_ptr() only.
153
struct crypt_cpu __percpu *cpu;
157
* Layout of each crypto request:
159
* struct ablkcipher_request
162
* struct dm_crypt_request
166
* The padding is added so that dm_crypt_request and the IV are
169
unsigned int dmreq_start;
172
unsigned int key_size;
173
unsigned int key_parts;
178
#define MIN_POOL_PAGES 32
179
#define MIN_BIO_PAGES 8
181
static struct kmem_cache *_crypt_io_pool;
183
static void clone_init(struct dm_crypt_io *, struct bio *);
184
static void kcryptd_queue_crypt(struct dm_crypt_io *io);
185
static u8 *iv_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq);
187
static struct crypt_cpu *this_crypt_config(struct crypt_config *cc)
189
return this_cpu_ptr(cc->cpu);
193
* Use this to access cipher attributes that are the same for each CPU.
195
static struct crypto_ablkcipher *any_tfm(struct crypt_config *cc)
197
return __this_cpu_ptr(cc->cpu)->tfms[0];
201
* Different IV generation algorithms:
203
* plain: the initial vector is the 32-bit little-endian version of the sector
204
* number, padded with zeros if necessary.
206
* plain64: the initial vector is the 64-bit little-endian version of the sector
207
* number, padded with zeros if necessary.
209
* essiv: "encrypted sector|salt initial vector", the sector number is
210
* encrypted with the bulk cipher using a salt as key. The salt
211
* should be derived from the bulk cipher's key via hashing.
213
* benbi: the 64-bit "big-endian 'narrow block'-count", starting at 1
214
* (needed for LRW-32-AES and possible other narrow block modes)
216
* null: the initial vector is always zero. Provides compatibility with
217
* obsolete loop_fish2 devices. Do not use for new devices.
219
* lmk: Compatible implementation of the block chaining mode used
220
* by the Loop-AES block device encryption system
221
* designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
222
* It operates on full 512 byte sectors and uses CBC
223
* with an IV derived from the sector number, the data and
224
* optionally extra IV seed.
225
* This means that after decryption the first block
226
* of sector must be tweaked according to decrypted data.
227
* Loop-AES can use three encryption schemes:
228
* version 1: is plain aes-cbc mode
229
* version 2: uses 64 multikey scheme with lmk IV generator
230
* version 3: the same as version 2 with additional IV seed
231
* (it uses 65 keys, last key is used as IV seed)
233
* plumb: unimplemented, see:
234
* http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454
237
static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
238
struct dm_crypt_request *dmreq)
240
memset(iv, 0, cc->iv_size);
241
*(__le32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
246
static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
247
struct dm_crypt_request *dmreq)
249
memset(iv, 0, cc->iv_size);
250
*(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
255
/* Initialise ESSIV - compute salt but no local memory allocations */
256
static int crypt_iv_essiv_init(struct crypt_config *cc)
258
struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
259
struct hash_desc desc;
260
struct scatterlist sg;
261
struct crypto_cipher *essiv_tfm;
264
sg_init_one(&sg, cc->key, cc->key_size);
265
desc.tfm = essiv->hash_tfm;
266
desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
268
err = crypto_hash_digest(&desc, &sg, cc->key_size, essiv->salt);
272
for_each_possible_cpu(cpu) {
273
essiv_tfm = per_cpu_ptr(cc->cpu, cpu)->iv_private,
275
err = crypto_cipher_setkey(essiv_tfm, essiv->salt,
276
crypto_hash_digestsize(essiv->hash_tfm));
284
/* Wipe salt and reset key derived from volume key */
285
static int crypt_iv_essiv_wipe(struct crypt_config *cc)
287
struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
288
unsigned salt_size = crypto_hash_digestsize(essiv->hash_tfm);
289
struct crypto_cipher *essiv_tfm;
292
memset(essiv->salt, 0, salt_size);
294
for_each_possible_cpu(cpu) {
295
essiv_tfm = per_cpu_ptr(cc->cpu, cpu)->iv_private;
296
r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size);
304
/* Set up per cpu cipher state */
305
static struct crypto_cipher *setup_essiv_cpu(struct crypt_config *cc,
306
struct dm_target *ti,
307
u8 *salt, unsigned saltsize)
309
struct crypto_cipher *essiv_tfm;
312
/* Setup the essiv_tfm with the given salt */
313
essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
314
if (IS_ERR(essiv_tfm)) {
315
ti->error = "Error allocating crypto tfm for ESSIV";
319
if (crypto_cipher_blocksize(essiv_tfm) !=
320
crypto_ablkcipher_ivsize(any_tfm(cc))) {
321
ti->error = "Block size of ESSIV cipher does "
322
"not match IV size of block cipher";
323
crypto_free_cipher(essiv_tfm);
324
return ERR_PTR(-EINVAL);
327
err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
329
ti->error = "Failed to set key for ESSIV cipher";
330
crypto_free_cipher(essiv_tfm);
337
static void crypt_iv_essiv_dtr(struct crypt_config *cc)
340
struct crypt_cpu *cpu_cc;
341
struct crypto_cipher *essiv_tfm;
342
struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
344
crypto_free_hash(essiv->hash_tfm);
345
essiv->hash_tfm = NULL;
350
for_each_possible_cpu(cpu) {
351
cpu_cc = per_cpu_ptr(cc->cpu, cpu);
352
essiv_tfm = cpu_cc->iv_private;
355
crypto_free_cipher(essiv_tfm);
357
cpu_cc->iv_private = NULL;
361
static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
364
struct crypto_cipher *essiv_tfm = NULL;
365
struct crypto_hash *hash_tfm = NULL;
370
ti->error = "Digest algorithm missing for ESSIV mode";
374
/* Allocate hash algorithm */
375
hash_tfm = crypto_alloc_hash(opts, 0, CRYPTO_ALG_ASYNC);
376
if (IS_ERR(hash_tfm)) {
377
ti->error = "Error initializing ESSIV hash";
378
err = PTR_ERR(hash_tfm);
382
salt = kzalloc(crypto_hash_digestsize(hash_tfm), GFP_KERNEL);
384
ti->error = "Error kmallocing salt storage in ESSIV";
389
cc->iv_gen_private.essiv.salt = salt;
390
cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
392
for_each_possible_cpu(cpu) {
393
essiv_tfm = setup_essiv_cpu(cc, ti, salt,
394
crypto_hash_digestsize(hash_tfm));
395
if (IS_ERR(essiv_tfm)) {
396
crypt_iv_essiv_dtr(cc);
397
return PTR_ERR(essiv_tfm);
399
per_cpu_ptr(cc->cpu, cpu)->iv_private = essiv_tfm;
405
if (hash_tfm && !IS_ERR(hash_tfm))
406
crypto_free_hash(hash_tfm);
411
static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
412
struct dm_crypt_request *dmreq)
414
struct crypto_cipher *essiv_tfm = this_crypt_config(cc)->iv_private;
416
memset(iv, 0, cc->iv_size);
417
*(__le64 *)iv = cpu_to_le64(dmreq->iv_sector);
418
crypto_cipher_encrypt_one(essiv_tfm, iv, iv);
423
static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
426
unsigned bs = crypto_ablkcipher_blocksize(any_tfm(cc));
429
/* we need to calculate how far we must shift the sector count
430
* to get the cipher block count, we use this shift in _gen */
432
if (1 << log != bs) {
433
ti->error = "cypher blocksize is not a power of 2";
438
ti->error = "cypher blocksize is > 512";
442
cc->iv_gen_private.benbi.shift = 9 - log;
447
static void crypt_iv_benbi_dtr(struct crypt_config *cc)
451
static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
452
struct dm_crypt_request *dmreq)
456
memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
458
val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
459
put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
464
static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
465
struct dm_crypt_request *dmreq)
467
memset(iv, 0, cc->iv_size);
472
static void crypt_iv_lmk_dtr(struct crypt_config *cc)
474
struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
476
if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
477
crypto_free_shash(lmk->hash_tfm);
478
lmk->hash_tfm = NULL;
484
static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
487
struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
489
lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0);
490
if (IS_ERR(lmk->hash_tfm)) {
491
ti->error = "Error initializing LMK hash";
492
return PTR_ERR(lmk->hash_tfm);
495
/* No seed in LMK version 2 */
496
if (cc->key_parts == cc->tfms_count) {
501
lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
503
crypt_iv_lmk_dtr(cc);
504
ti->error = "Error kmallocing seed storage in LMK";
511
static int crypt_iv_lmk_init(struct crypt_config *cc)
513
struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
514
int subkey_size = cc->key_size / cc->key_parts;
516
/* LMK seed is on the position of LMK_KEYS + 1 key */
518
memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
519
crypto_shash_digestsize(lmk->hash_tfm));
524
static int crypt_iv_lmk_wipe(struct crypt_config *cc)
526
struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
529
memset(lmk->seed, 0, LMK_SEED_SIZE);
534
static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
535
struct dm_crypt_request *dmreq,
538
struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
540
struct shash_desc desc;
541
char ctx[crypto_shash_descsize(lmk->hash_tfm)];
543
struct md5_state md5state;
547
sdesc.desc.tfm = lmk->hash_tfm;
548
sdesc.desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
550
r = crypto_shash_init(&sdesc.desc);
555
r = crypto_shash_update(&sdesc.desc, lmk->seed, LMK_SEED_SIZE);
560
/* Sector is always 512B, block size 16, add data of blocks 1-31 */
561
r = crypto_shash_update(&sdesc.desc, data + 16, 16 * 31);
565
/* Sector is cropped to 56 bits here */
566
buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
567
buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
568
buf[2] = cpu_to_le32(4024);
570
r = crypto_shash_update(&sdesc.desc, (u8 *)buf, sizeof(buf));
574
/* No MD5 padding here */
575
r = crypto_shash_export(&sdesc.desc, &md5state);
579
for (i = 0; i < MD5_HASH_WORDS; i++)
580
__cpu_to_le32s(&md5state.hash[i]);
581
memcpy(iv, &md5state.hash, cc->iv_size);
586
static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
587
struct dm_crypt_request *dmreq)
592
if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
593
src = kmap_atomic(sg_page(&dmreq->sg_in), KM_USER0);
594
r = crypt_iv_lmk_one(cc, iv, dmreq, src + dmreq->sg_in.offset);
595
kunmap_atomic(src, KM_USER0);
597
memset(iv, 0, cc->iv_size);
602
static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
603
struct dm_crypt_request *dmreq)
608
if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
611
dst = kmap_atomic(sg_page(&dmreq->sg_out), KM_USER0);
612
r = crypt_iv_lmk_one(cc, iv, dmreq, dst + dmreq->sg_out.offset);
614
/* Tweak the first block of plaintext sector */
616
crypto_xor(dst + dmreq->sg_out.offset, iv, cc->iv_size);
618
kunmap_atomic(dst, KM_USER0);
622
static struct crypt_iv_operations crypt_iv_plain_ops = {
623
.generator = crypt_iv_plain_gen
626
static struct crypt_iv_operations crypt_iv_plain64_ops = {
627
.generator = crypt_iv_plain64_gen
630
static struct crypt_iv_operations crypt_iv_essiv_ops = {
631
.ctr = crypt_iv_essiv_ctr,
632
.dtr = crypt_iv_essiv_dtr,
633
.init = crypt_iv_essiv_init,
634
.wipe = crypt_iv_essiv_wipe,
635
.generator = crypt_iv_essiv_gen
638
static struct crypt_iv_operations crypt_iv_benbi_ops = {
639
.ctr = crypt_iv_benbi_ctr,
640
.dtr = crypt_iv_benbi_dtr,
641
.generator = crypt_iv_benbi_gen
644
static struct crypt_iv_operations crypt_iv_null_ops = {
645
.generator = crypt_iv_null_gen
648
static struct crypt_iv_operations crypt_iv_lmk_ops = {
649
.ctr = crypt_iv_lmk_ctr,
650
.dtr = crypt_iv_lmk_dtr,
651
.init = crypt_iv_lmk_init,
652
.wipe = crypt_iv_lmk_wipe,
653
.generator = crypt_iv_lmk_gen,
654
.post = crypt_iv_lmk_post
657
static void crypt_convert_init(struct crypt_config *cc,
658
struct convert_context *ctx,
659
struct bio *bio_out, struct bio *bio_in,
662
ctx->bio_in = bio_in;
663
ctx->bio_out = bio_out;
666
ctx->idx_in = bio_in ? bio_in->bi_idx : 0;
667
ctx->idx_out = bio_out ? bio_out->bi_idx : 0;
668
ctx->sector = sector + cc->iv_offset;
669
init_completion(&ctx->restart);
672
static struct dm_crypt_request *dmreq_of_req(struct crypt_config *cc,
673
struct ablkcipher_request *req)
675
return (struct dm_crypt_request *)((char *)req + cc->dmreq_start);
678
static struct ablkcipher_request *req_of_dmreq(struct crypt_config *cc,
679
struct dm_crypt_request *dmreq)
681
return (struct ablkcipher_request *)((char *)dmreq - cc->dmreq_start);
684
static u8 *iv_of_dmreq(struct crypt_config *cc,
685
struct dm_crypt_request *dmreq)
687
return (u8 *)ALIGN((unsigned long)(dmreq + 1),
688
crypto_ablkcipher_alignmask(any_tfm(cc)) + 1);
691
static int crypt_convert_block(struct crypt_config *cc,
692
struct convert_context *ctx,
693
struct ablkcipher_request *req)
695
struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in);
696
struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out);
697
struct dm_crypt_request *dmreq;
701
dmreq = dmreq_of_req(cc, req);
702
iv = iv_of_dmreq(cc, dmreq);
704
dmreq->iv_sector = ctx->sector;
706
sg_init_table(&dmreq->sg_in, 1);
707
sg_set_page(&dmreq->sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT,
708
bv_in->bv_offset + ctx->offset_in);
710
sg_init_table(&dmreq->sg_out, 1);
711
sg_set_page(&dmreq->sg_out, bv_out->bv_page, 1 << SECTOR_SHIFT,
712
bv_out->bv_offset + ctx->offset_out);
714
ctx->offset_in += 1 << SECTOR_SHIFT;
715
if (ctx->offset_in >= bv_in->bv_len) {
720
ctx->offset_out += 1 << SECTOR_SHIFT;
721
if (ctx->offset_out >= bv_out->bv_len) {
726
if (cc->iv_gen_ops) {
727
r = cc->iv_gen_ops->generator(cc, iv, dmreq);
732
ablkcipher_request_set_crypt(req, &dmreq->sg_in, &dmreq->sg_out,
733
1 << SECTOR_SHIFT, iv);
735
if (bio_data_dir(ctx->bio_in) == WRITE)
736
r = crypto_ablkcipher_encrypt(req);
738
r = crypto_ablkcipher_decrypt(req);
740
if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
741
r = cc->iv_gen_ops->post(cc, iv, dmreq);
746
static void kcryptd_async_done(struct crypto_async_request *async_req,
749
static void crypt_alloc_req(struct crypt_config *cc,
750
struct convert_context *ctx)
752
struct crypt_cpu *this_cc = this_crypt_config(cc);
753
unsigned key_index = ctx->sector & (cc->tfms_count - 1);
756
this_cc->req = mempool_alloc(cc->req_pool, GFP_NOIO);
758
ablkcipher_request_set_tfm(this_cc->req, this_cc->tfms[key_index]);
759
ablkcipher_request_set_callback(this_cc->req,
760
CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
761
kcryptd_async_done, dmreq_of_req(cc, this_cc->req));
765
* Encrypt / decrypt data from one bio to another one (can be the same one)
767
static int crypt_convert(struct crypt_config *cc,
768
struct convert_context *ctx)
770
struct crypt_cpu *this_cc = this_crypt_config(cc);
773
atomic_set(&ctx->pending, 1);
775
while(ctx->idx_in < ctx->bio_in->bi_vcnt &&
776
ctx->idx_out < ctx->bio_out->bi_vcnt) {
778
crypt_alloc_req(cc, ctx);
780
atomic_inc(&ctx->pending);
782
r = crypt_convert_block(cc, ctx, this_cc->req);
787
wait_for_completion(&ctx->restart);
788
INIT_COMPLETION(ctx->restart);
797
atomic_dec(&ctx->pending);
804
atomic_dec(&ctx->pending);
812
static void dm_crypt_bio_destructor(struct bio *bio)
814
struct dm_crypt_io *io = bio->bi_private;
815
struct crypt_config *cc = io->target->private;
817
bio_free(bio, cc->bs);
821
* Generate a new unfragmented bio with the given size
822
* This should never violate the device limitations
823
* May return a smaller bio when running out of pages, indicated by
824
* *out_of_pages set to 1.
826
static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size,
827
unsigned *out_of_pages)
829
struct crypt_config *cc = io->target->private;
831
unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
832
gfp_t gfp_mask = GFP_NOIO | __GFP_HIGHMEM;
836
clone = bio_alloc_bioset(GFP_NOIO, nr_iovecs, cc->bs);
840
clone_init(io, clone);
843
for (i = 0; i < nr_iovecs; i++) {
844
page = mempool_alloc(cc->page_pool, gfp_mask);
851
* if additional pages cannot be allocated without waiting,
852
* return a partially allocated bio, the caller will then try
853
* to allocate additional bios while submitting this partial bio
855
if (i == (MIN_BIO_PAGES - 1))
856
gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT;
858
len = (size > PAGE_SIZE) ? PAGE_SIZE : size;
860
if (!bio_add_page(clone, page, len, 0)) {
861
mempool_free(page, cc->page_pool);
868
if (!clone->bi_size) {
876
static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *clone)
881
for (i = 0; i < clone->bi_vcnt; i++) {
882
bv = bio_iovec_idx(clone, i);
883
BUG_ON(!bv->bv_page);
884
mempool_free(bv->bv_page, cc->page_pool);
889
static struct dm_crypt_io *crypt_io_alloc(struct dm_target *ti,
890
struct bio *bio, sector_t sector)
892
struct crypt_config *cc = ti->private;
893
struct dm_crypt_io *io;
895
io = mempool_alloc(cc->io_pool, GFP_NOIO);
901
atomic_set(&io->pending, 0);
906
static void crypt_inc_pending(struct dm_crypt_io *io)
908
atomic_inc(&io->pending);
912
* One of the bios was finished. Check for completion of
913
* the whole request and correctly clean up the buffer.
914
* If base_io is set, wait for the last fragment to complete.
916
static void crypt_dec_pending(struct dm_crypt_io *io)
918
struct crypt_config *cc = io->target->private;
919
struct bio *base_bio = io->base_bio;
920
struct dm_crypt_io *base_io = io->base_io;
921
int error = io->error;
923
if (!atomic_dec_and_test(&io->pending))
926
mempool_free(io, cc->io_pool);
928
if (likely(!base_io))
929
bio_endio(base_bio, error);
931
if (error && !base_io->error)
932
base_io->error = error;
933
crypt_dec_pending(base_io);
938
* kcryptd/kcryptd_io:
940
* Needed because it would be very unwise to do decryption in an
943
* kcryptd performs the actual encryption or decryption.
945
* kcryptd_io performs the IO submission.
947
* They must be separated as otherwise the final stages could be
948
* starved by new requests which can block in the first stages due
949
* to memory allocation.
951
* The work is done per CPU global for all dm-crypt instances.
952
* They should not depend on each other and do not block.
954
static void crypt_endio(struct bio *clone, int error)
956
struct dm_crypt_io *io = clone->bi_private;
957
struct crypt_config *cc = io->target->private;
958
unsigned rw = bio_data_dir(clone);
960
if (unlikely(!bio_flagged(clone, BIO_UPTODATE) && !error))
964
* free the processed pages
967
crypt_free_buffer_pages(cc, clone);
971
if (rw == READ && !error) {
972
kcryptd_queue_crypt(io);
979
crypt_dec_pending(io);
982
static void clone_init(struct dm_crypt_io *io, struct bio *clone)
984
struct crypt_config *cc = io->target->private;
986
clone->bi_private = io;
987
clone->bi_end_io = crypt_endio;
988
clone->bi_bdev = cc->dev->bdev;
989
clone->bi_rw = io->base_bio->bi_rw;
990
clone->bi_destructor = dm_crypt_bio_destructor;
993
static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
995
struct crypt_config *cc = io->target->private;
996
struct bio *base_bio = io->base_bio;
1000
* The block layer might modify the bvec array, so always
1001
* copy the required bvecs because we need the original
1002
* one in order to decrypt the whole bio data *afterwards*.
1004
clone = bio_alloc_bioset(gfp, bio_segments(base_bio), cc->bs);
1008
crypt_inc_pending(io);
1010
clone_init(io, clone);
1012
clone->bi_vcnt = bio_segments(base_bio);
1013
clone->bi_size = base_bio->bi_size;
1014
clone->bi_sector = cc->start + io->sector;
1015
memcpy(clone->bi_io_vec, bio_iovec(base_bio),
1016
sizeof(struct bio_vec) * clone->bi_vcnt);
1018
generic_make_request(clone);
1022
static void kcryptd_io_write(struct dm_crypt_io *io)
1024
struct bio *clone = io->ctx.bio_out;
1025
generic_make_request(clone);
1028
static void kcryptd_io(struct work_struct *work)
1030
struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1032
if (bio_data_dir(io->base_bio) == READ) {
1033
crypt_inc_pending(io);
1034
if (kcryptd_io_read(io, GFP_NOIO))
1035
io->error = -ENOMEM;
1036
crypt_dec_pending(io);
1038
kcryptd_io_write(io);
1041
static void kcryptd_queue_io(struct dm_crypt_io *io)
1043
struct crypt_config *cc = io->target->private;
1045
INIT_WORK(&io->work, kcryptd_io);
1046
queue_work(cc->io_queue, &io->work);
1049
static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io,
1050
int error, int async)
1052
struct bio *clone = io->ctx.bio_out;
1053
struct crypt_config *cc = io->target->private;
1055
if (unlikely(error < 0)) {
1056
crypt_free_buffer_pages(cc, clone);
1059
crypt_dec_pending(io);
1063
/* crypt_convert should have filled the clone bio */
1064
BUG_ON(io->ctx.idx_out < clone->bi_vcnt);
1066
clone->bi_sector = cc->start + io->sector;
1069
kcryptd_queue_io(io);
1071
generic_make_request(clone);
1074
static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
1076
struct crypt_config *cc = io->target->private;
1078
struct dm_crypt_io *new_io;
1080
unsigned out_of_pages = 0;
1081
unsigned remaining = io->base_bio->bi_size;
1082
sector_t sector = io->sector;
1086
* Prevent io from disappearing until this function completes.
1088
crypt_inc_pending(io);
1089
crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
1092
* The allocated buffers can be smaller than the whole bio,
1093
* so repeat the whole process until all the data can be handled.
1096
clone = crypt_alloc_buffer(io, remaining, &out_of_pages);
1097
if (unlikely(!clone)) {
1098
io->error = -ENOMEM;
1102
io->ctx.bio_out = clone;
1103
io->ctx.idx_out = 0;
1105
remaining -= clone->bi_size;
1106
sector += bio_sectors(clone);
1108
crypt_inc_pending(io);
1109
r = crypt_convert(cc, &io->ctx);
1110
crypt_finished = atomic_dec_and_test(&io->ctx.pending);
1112
/* Encryption was already finished, submit io now */
1113
if (crypt_finished) {
1114
kcryptd_crypt_write_io_submit(io, r, 0);
1117
* If there was an error, do not try next fragments.
1118
* For async, error is processed in async handler.
1120
if (unlikely(r < 0))
1123
io->sector = sector;
1127
* Out of memory -> run queues
1128
* But don't wait if split was due to the io size restriction
1130
if (unlikely(out_of_pages))
1131
congestion_wait(BLK_RW_ASYNC, HZ/100);
1134
* With async crypto it is unsafe to share the crypto context
1135
* between fragments, so switch to a new dm_crypt_io structure.
1137
if (unlikely(!crypt_finished && remaining)) {
1138
new_io = crypt_io_alloc(io->target, io->base_bio,
1140
crypt_inc_pending(new_io);
1141
crypt_convert_init(cc, &new_io->ctx, NULL,
1142
io->base_bio, sector);
1143
new_io->ctx.idx_in = io->ctx.idx_in;
1144
new_io->ctx.offset_in = io->ctx.offset_in;
1147
* Fragments after the first use the base_io
1151
new_io->base_io = io;
1153
new_io->base_io = io->base_io;
1154
crypt_inc_pending(io->base_io);
1155
crypt_dec_pending(io);
1162
crypt_dec_pending(io);
1165
static void kcryptd_crypt_read_done(struct dm_crypt_io *io, int error)
1167
if (unlikely(error < 0))
1170
crypt_dec_pending(io);
1173
static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
1175
struct crypt_config *cc = io->target->private;
1178
crypt_inc_pending(io);
1180
crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
1183
r = crypt_convert(cc, &io->ctx);
1185
if (atomic_dec_and_test(&io->ctx.pending))
1186
kcryptd_crypt_read_done(io, r);
1188
crypt_dec_pending(io);
1191
static void kcryptd_async_done(struct crypto_async_request *async_req,
1194
struct dm_crypt_request *dmreq = async_req->data;
1195
struct convert_context *ctx = dmreq->ctx;
1196
struct dm_crypt_io *io = container_of(ctx, struct dm_crypt_io, ctx);
1197
struct crypt_config *cc = io->target->private;
1199
if (error == -EINPROGRESS) {
1200
complete(&ctx->restart);
1204
if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
1205
error = cc->iv_gen_ops->post(cc, iv_of_dmreq(cc, dmreq), dmreq);
1207
mempool_free(req_of_dmreq(cc, dmreq), cc->req_pool);
1209
if (!atomic_dec_and_test(&ctx->pending))
1212
if (bio_data_dir(io->base_bio) == READ)
1213
kcryptd_crypt_read_done(io, error);
1215
kcryptd_crypt_write_io_submit(io, error, 1);
1218
static void kcryptd_crypt(struct work_struct *work)
1220
struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
1222
if (bio_data_dir(io->base_bio) == READ)
1223
kcryptd_crypt_read_convert(io);
1225
kcryptd_crypt_write_convert(io);
1228
static void kcryptd_queue_crypt(struct dm_crypt_io *io)
1230
struct crypt_config *cc = io->target->private;
1232
INIT_WORK(&io->work, kcryptd_crypt);
1233
queue_work(cc->crypt_queue, &io->work);
1237
* Decode key from its hex representation
1239
static int crypt_decode_key(u8 *key, char *hex, unsigned int size)
1247
for (i = 0; i < size; i++) {
1251
key[i] = (u8)simple_strtoul(buffer, &endp, 16);
1253
if (endp != &buffer[2])
1264
* Encode key into its hex representation
1266
static void crypt_encode_key(char *hex, u8 *key, unsigned int size)
1270
for (i = 0; i < size; i++) {
1271
sprintf(hex, "%02x", *key);
1277
static void crypt_free_tfms(struct crypt_config *cc, int cpu)
1279
struct crypt_cpu *cpu_cc = per_cpu_ptr(cc->cpu, cpu);
1282
for (i = 0; i < cc->tfms_count; i++)
1283
if (cpu_cc->tfms[i] && !IS_ERR(cpu_cc->tfms[i])) {
1284
crypto_free_ablkcipher(cpu_cc->tfms[i]);
1285
cpu_cc->tfms[i] = NULL;
1289
static int crypt_alloc_tfms(struct crypt_config *cc, int cpu, char *ciphermode)
1291
struct crypt_cpu *cpu_cc = per_cpu_ptr(cc->cpu, cpu);
1295
for (i = 0; i < cc->tfms_count; i++) {
1296
cpu_cc->tfms[i] = crypto_alloc_ablkcipher(ciphermode, 0, 0);
1297
if (IS_ERR(cpu_cc->tfms[i])) {
1298
err = PTR_ERR(cpu_cc->tfms[i]);
1299
crypt_free_tfms(cc, cpu);
1307
static int crypt_setkey_allcpus(struct crypt_config *cc)
1309
unsigned subkey_size = cc->key_size >> ilog2(cc->tfms_count);
1310
int cpu, err = 0, i, r;
1312
for_each_possible_cpu(cpu) {
1313
for (i = 0; i < cc->tfms_count; i++) {
1314
r = crypto_ablkcipher_setkey(per_cpu_ptr(cc->cpu, cpu)->tfms[i],
1315
cc->key + (i * subkey_size), subkey_size);
1324
static int crypt_set_key(struct crypt_config *cc, char *key)
1327
int key_string_len = strlen(key);
1329
/* The key size may not be changed. */
1330
if (cc->key_size != (key_string_len >> 1))
1333
/* Hyphen (which gives a key_size of zero) means there is no key. */
1334
if (!cc->key_size && strcmp(key, "-"))
1337
if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0)
1340
set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1342
r = crypt_setkey_allcpus(cc);
1345
/* Hex key string not needed after here, so wipe it. */
1346
memset(key, '0', key_string_len);
1351
static int crypt_wipe_key(struct crypt_config *cc)
1353
clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
1354
memset(&cc->key, 0, cc->key_size * sizeof(u8));
1356
return crypt_setkey_allcpus(cc);
1359
static void crypt_dtr(struct dm_target *ti)
1361
struct crypt_config *cc = ti->private;
1362
struct crypt_cpu *cpu_cc;
1371
destroy_workqueue(cc->io_queue);
1372
if (cc->crypt_queue)
1373
destroy_workqueue(cc->crypt_queue);
1376
for_each_possible_cpu(cpu) {
1377
cpu_cc = per_cpu_ptr(cc->cpu, cpu);
1379
mempool_free(cpu_cc->req, cc->req_pool);
1380
crypt_free_tfms(cc, cpu);
1384
bioset_free(cc->bs);
1387
mempool_destroy(cc->page_pool);
1389
mempool_destroy(cc->req_pool);
1391
mempool_destroy(cc->io_pool);
1393
if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
1394
cc->iv_gen_ops->dtr(cc);
1397
dm_put_device(ti, cc->dev);
1400
free_percpu(cc->cpu);
1403
kzfree(cc->cipher_string);
1405
/* Must zero key material before freeing */
1409
static int crypt_ctr_cipher(struct dm_target *ti,
1410
char *cipher_in, char *key)
1412
struct crypt_config *cc = ti->private;
1413
char *tmp, *cipher, *chainmode, *ivmode, *ivopts, *keycount;
1414
char *cipher_api = NULL;
1415
int cpu, ret = -EINVAL;
1417
/* Convert to crypto api definition? */
1418
if (strchr(cipher_in, '(')) {
1419
ti->error = "Bad cipher specification";
1423
cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
1424
if (!cc->cipher_string)
1428
* Legacy dm-crypt cipher specification
1429
* cipher[:keycount]-mode-iv:ivopts
1432
keycount = strsep(&tmp, "-");
1433
cipher = strsep(&keycount, ":");
1437
else if (sscanf(keycount, "%u", &cc->tfms_count) != 1 ||
1438
!is_power_of_2(cc->tfms_count)) {
1439
ti->error = "Bad cipher key count specification";
1442
cc->key_parts = cc->tfms_count;
1444
cc->cipher = kstrdup(cipher, GFP_KERNEL);
1448
chainmode = strsep(&tmp, "-");
1449
ivopts = strsep(&tmp, "-");
1450
ivmode = strsep(&ivopts, ":");
1453
DMWARN("Ignoring unexpected additional cipher options");
1455
cc->cpu = __alloc_percpu(sizeof(*(cc->cpu)) +
1456
cc->tfms_count * sizeof(*(cc->cpu->tfms)),
1457
__alignof__(struct crypt_cpu));
1459
ti->error = "Cannot allocate per cpu state";
1464
* For compatibility with the original dm-crypt mapping format, if
1465
* only the cipher name is supplied, use cbc-plain.
1467
if (!chainmode || (!strcmp(chainmode, "plain") && !ivmode)) {
1472
if (strcmp(chainmode, "ecb") && !ivmode) {
1473
ti->error = "IV mechanism required";
1477
cipher_api = kmalloc(CRYPTO_MAX_ALG_NAME, GFP_KERNEL);
1481
ret = snprintf(cipher_api, CRYPTO_MAX_ALG_NAME,
1482
"%s(%s)", chainmode, cipher);
1488
/* Allocate cipher */
1489
for_each_possible_cpu(cpu) {
1490
ret = crypt_alloc_tfms(cc, cpu, cipher_api);
1492
ti->error = "Error allocating crypto tfm";
1497
/* Initialize and set key */
1498
ret = crypt_set_key(cc, key);
1500
ti->error = "Error decoding and setting key";
1505
cc->iv_size = crypto_ablkcipher_ivsize(any_tfm(cc));
1507
/* at least a 64 bit sector number should fit in our buffer */
1508
cc->iv_size = max(cc->iv_size,
1509
(unsigned int)(sizeof(u64) / sizeof(u8)));
1511
DMWARN("Selected cipher does not support IVs");
1515
/* Choose ivmode, see comments at iv code. */
1517
cc->iv_gen_ops = NULL;
1518
else if (strcmp(ivmode, "plain") == 0)
1519
cc->iv_gen_ops = &crypt_iv_plain_ops;
1520
else if (strcmp(ivmode, "plain64") == 0)
1521
cc->iv_gen_ops = &crypt_iv_plain64_ops;
1522
else if (strcmp(ivmode, "essiv") == 0)
1523
cc->iv_gen_ops = &crypt_iv_essiv_ops;
1524
else if (strcmp(ivmode, "benbi") == 0)
1525
cc->iv_gen_ops = &crypt_iv_benbi_ops;
1526
else if (strcmp(ivmode, "null") == 0)
1527
cc->iv_gen_ops = &crypt_iv_null_ops;
1528
else if (strcmp(ivmode, "lmk") == 0) {
1529
cc->iv_gen_ops = &crypt_iv_lmk_ops;
1530
/* Version 2 and 3 is recognised according
1531
* to length of provided multi-key string.
1532
* If present (version 3), last key is used as IV seed.
1534
if (cc->key_size % cc->key_parts)
1538
ti->error = "Invalid IV mode";
1543
if (cc->iv_gen_ops && cc->iv_gen_ops->ctr) {
1544
ret = cc->iv_gen_ops->ctr(cc, ti, ivopts);
1546
ti->error = "Error creating IV";
1551
/* Initialize IV (set keys for ESSIV etc) */
1552
if (cc->iv_gen_ops && cc->iv_gen_ops->init) {
1553
ret = cc->iv_gen_ops->init(cc);
1555
ti->error = "Error initialising IV";
1566
ti->error = "Cannot allocate cipher strings";
1571
* Construct an encryption mapping:
1572
* <cipher> <key> <iv_offset> <dev_path> <start>
1574
static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
1576
struct crypt_config *cc;
1577
unsigned int key_size, opt_params;
1578
unsigned long long tmpll;
1580
struct dm_arg_set as;
1581
const char *opt_string;
1583
static struct dm_arg _args[] = {
1584
{0, 1, "Invalid number of feature args"},
1588
ti->error = "Not enough arguments";
1592
key_size = strlen(argv[1]) >> 1;
1594
cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
1596
ti->error = "Cannot allocate encryption context";
1599
cc->key_size = key_size;
1602
ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
1607
cc->io_pool = mempool_create_slab_pool(MIN_IOS, _crypt_io_pool);
1609
ti->error = "Cannot allocate crypt io mempool";
1613
cc->dmreq_start = sizeof(struct ablkcipher_request);
1614
cc->dmreq_start += crypto_ablkcipher_reqsize(any_tfm(cc));
1615
cc->dmreq_start = ALIGN(cc->dmreq_start, crypto_tfm_ctx_alignment());
1616
cc->dmreq_start += crypto_ablkcipher_alignmask(any_tfm(cc)) &
1617
~(crypto_tfm_ctx_alignment() - 1);
1619
cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start +
1620
sizeof(struct dm_crypt_request) + cc->iv_size);
1621
if (!cc->req_pool) {
1622
ti->error = "Cannot allocate crypt request mempool";
1626
cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
1627
if (!cc->page_pool) {
1628
ti->error = "Cannot allocate page mempool";
1632
cc->bs = bioset_create(MIN_IOS, 0);
1634
ti->error = "Cannot allocate crypt bioset";
1639
if (sscanf(argv[2], "%llu", &tmpll) != 1) {
1640
ti->error = "Invalid iv_offset sector";
1643
cc->iv_offset = tmpll;
1645
if (dm_get_device(ti, argv[3], dm_table_get_mode(ti->table), &cc->dev)) {
1646
ti->error = "Device lookup failed";
1650
if (sscanf(argv[4], "%llu", &tmpll) != 1) {
1651
ti->error = "Invalid device sector";
1659
/* Optional parameters */
1664
ret = dm_read_arg_group(_args, &as, &opt_params, &ti->error);
1668
opt_string = dm_shift_arg(&as);
1670
if (opt_params == 1 && opt_string &&
1671
!strcasecmp(opt_string, "allow_discards"))
1672
ti->num_discard_requests = 1;
1673
else if (opt_params) {
1675
ti->error = "Invalid feature arguments";
1681
cc->io_queue = alloc_workqueue("kcryptd_io",
1685
if (!cc->io_queue) {
1686
ti->error = "Couldn't create kcryptd io queue";
1690
cc->crypt_queue = alloc_workqueue("kcryptd",
1695
if (!cc->crypt_queue) {
1696
ti->error = "Couldn't create kcryptd queue";
1700
ti->num_flush_requests = 1;
1701
ti->discard_zeroes_data_unsupported = 1;
1710
static int crypt_map(struct dm_target *ti, struct bio *bio,
1711
union map_info *map_context)
1713
struct dm_crypt_io *io;
1714
struct crypt_config *cc;
1717
* If bio is REQ_FLUSH or REQ_DISCARD, just bypass crypt queues.
1718
* - for REQ_FLUSH device-mapper core ensures that no IO is in-flight
1719
* - for REQ_DISCARD caller must use flush if IO ordering matters
1721
if (unlikely(bio->bi_rw & (REQ_FLUSH | REQ_DISCARD))) {
1723
bio->bi_bdev = cc->dev->bdev;
1724
if (bio_sectors(bio))
1725
bio->bi_sector = cc->start + dm_target_offset(ti, bio->bi_sector);
1726
return DM_MAPIO_REMAPPED;
1729
io = crypt_io_alloc(ti, bio, dm_target_offset(ti, bio->bi_sector));
1731
if (bio_data_dir(io->base_bio) == READ) {
1732
if (kcryptd_io_read(io, GFP_NOWAIT))
1733
kcryptd_queue_io(io);
1735
kcryptd_queue_crypt(io);
1737
return DM_MAPIO_SUBMITTED;
1740
static int crypt_status(struct dm_target *ti, status_type_t type,
1741
char *result, unsigned int maxlen)
1743
struct crypt_config *cc = ti->private;
1744
unsigned int sz = 0;
1747
case STATUSTYPE_INFO:
1751
case STATUSTYPE_TABLE:
1752
DMEMIT("%s ", cc->cipher_string);
1754
if (cc->key_size > 0) {
1755
if ((maxlen - sz) < ((cc->key_size << 1) + 1))
1758
crypt_encode_key(result + sz, cc->key, cc->key_size);
1759
sz += cc->key_size << 1;
1766
DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
1767
cc->dev->name, (unsigned long long)cc->start);
1769
if (ti->num_discard_requests)
1770
DMEMIT(" 1 allow_discards");
1777
static void crypt_postsuspend(struct dm_target *ti)
1779
struct crypt_config *cc = ti->private;
1781
set_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1784
static int crypt_preresume(struct dm_target *ti)
1786
struct crypt_config *cc = ti->private;
1788
if (!test_bit(DM_CRYPT_KEY_VALID, &cc->flags)) {
1789
DMERR("aborting resume - crypt key is not set.");
1796
static void crypt_resume(struct dm_target *ti)
1798
struct crypt_config *cc = ti->private;
1800
clear_bit(DM_CRYPT_SUSPENDED, &cc->flags);
1803
/* Message interface
1807
static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
1809
struct crypt_config *cc = ti->private;
1815
if (!strcasecmp(argv[0], "key")) {
1816
if (!test_bit(DM_CRYPT_SUSPENDED, &cc->flags)) {
1817
DMWARN("not suspended during key manipulation.");
1820
if (argc == 3 && !strcasecmp(argv[1], "set")) {
1821
ret = crypt_set_key(cc, argv[2]);
1824
if (cc->iv_gen_ops && cc->iv_gen_ops->init)
1825
ret = cc->iv_gen_ops->init(cc);
1828
if (argc == 2 && !strcasecmp(argv[1], "wipe")) {
1829
if (cc->iv_gen_ops && cc->iv_gen_ops->wipe) {
1830
ret = cc->iv_gen_ops->wipe(cc);
1834
return crypt_wipe_key(cc);
1839
DMWARN("unrecognised message received.");
1843
static int crypt_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
1844
struct bio_vec *biovec, int max_size)
1846
struct crypt_config *cc = ti->private;
1847
struct request_queue *q = bdev_get_queue(cc->dev->bdev);
1849
if (!q->merge_bvec_fn)
1852
bvm->bi_bdev = cc->dev->bdev;
1853
bvm->bi_sector = cc->start + dm_target_offset(ti, bvm->bi_sector);
1855
return min(max_size, q->merge_bvec_fn(q, bvm, biovec));
1858
static int crypt_iterate_devices(struct dm_target *ti,
1859
iterate_devices_callout_fn fn, void *data)
1861
struct crypt_config *cc = ti->private;
1863
return fn(ti, cc->dev, cc->start, ti->len, data);
1866
static struct target_type crypt_target = {
1868
.version = {1, 11, 0},
1869
.module = THIS_MODULE,
1873
.status = crypt_status,
1874
.postsuspend = crypt_postsuspend,
1875
.preresume = crypt_preresume,
1876
.resume = crypt_resume,
1877
.message = crypt_message,
1878
.merge = crypt_merge,
1879
.iterate_devices = crypt_iterate_devices,
1882
static int __init dm_crypt_init(void)
1886
_crypt_io_pool = KMEM_CACHE(dm_crypt_io, 0);
1887
if (!_crypt_io_pool)
1890
r = dm_register_target(&crypt_target);
1892
DMERR("register failed %d", r);
1893
kmem_cache_destroy(_crypt_io_pool);
1899
static void __exit dm_crypt_exit(void)
1901
dm_unregister_target(&crypt_target);
1902
kmem_cache_destroy(_crypt_io_pool);
1905
module_init(dm_crypt_init);
1906
module_exit(dm_crypt_exit);
1908
MODULE_AUTHOR("Christophe Saout <christophe@saout.de>");
1909
MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption");
1910
MODULE_LICENSE("GPL");