/* * Copyright (C) 2003 Christophe Saout <christophe@saout.de> * Copyright (C) 2004 Clemens Fruhwirth <clemens@endorphin.org> * * This file is released under the GPL. */ #include <linux/module.h> #include <linux/init.h> #include <linux/kernel.h> #include <linux/bio.h> #include <linux/blkdev.h> #include <linux/mempool.h> #include <linux/slab.h> #include <linux/crypto.h> #include <linux/workqueue.h> #include <asm/atomic.h> #include <asm/scatterlist.h> #include <asm/page.h> #include "dm.h" #define PFX "crypt: " /* * per bio private data */ struct crypt_io { struct dm_target *target; struct bio *bio; struct bio *first_clone; struct work_struct work; atomic_t pending; int error; }; /* * context holding the current state of a multi-part conversion */ struct convert_context { struct bio *bio_in; struct bio *bio_out; unsigned int offset_in; unsigned int offset_out; unsigned int idx_in; unsigned int idx_out; sector_t sector; int write; }; struct crypt_config; struct crypt_iv_operations { int (*ctr)(struct crypt_config *cc, struct dm_target *ti, const char *opts); void (*dtr)(struct crypt_config *cc); const char *(*status)(struct crypt_config *cc); int (*generator)(struct crypt_config *cc, u8 *iv, sector_t sector); }; /* * Crypt: maps a linear range of a block device * and encrypts / decrypts at the same time. */ struct crypt_config { struct dm_dev *dev; sector_t start; /* * pool for per bio private data and * for encryption buffer pages */ mempool_t *io_pool; mempool_t *page_pool; /* * crypto related data */ struct crypt_iv_operations *iv_gen_ops; char *iv_mode; void *iv_gen_private; sector_t iv_offset; unsigned int iv_size; struct crypto_tfm *tfm; unsigned int key_size; u8 key[0]; }; #define MIN_IOS 256 #define MIN_POOL_PAGES 32 #define MIN_BIO_PAGES 8 static kmem_cache_t *_crypt_io_pool; /* * Mempool alloc and free functions for the page */ static void *mempool_alloc_page(unsigned int __nocast gfp_mask, void *data) { return alloc_page(gfp_mask); } static void mempool_free_page(void *page, void *data) { __free_page(page); } /* * Different IV generation algorithms: * * plain: the initial vector is the 32-bit low-endian version of the sector * number, padded with zeros if neccessary. * * ess_iv: "encrypted sector|salt initial vector", the sector number is * encrypted with the bulk cipher using a salt as key. The salt * should be derived from the bulk cipher's key via hashing. * * plumb: unimplemented, see: * http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/454 */ static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv, sector_t sector) { memset(iv, 0, cc->iv_size); *(u32 *)iv = cpu_to_le32(sector & 0xffffffff); return 0; } static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti, const char *opts) { struct crypto_tfm *essiv_tfm; struct crypto_tfm *hash_tfm; struct scatterlist sg; unsigned int saltsize; u8 *salt; if (opts == NULL) { ti->error = PFX "Digest algorithm missing for ESSIV mode"; return -EINVAL; } /* Hash the cipher key with the given hash algorithm */ hash_tfm = crypto_alloc_tfm(opts, 0); if (hash_tfm == NULL) { ti->error = PFX "Error initializing ESSIV hash"; return -EINVAL; } if (crypto_tfm_alg_type(hash_tfm) != CRYPTO_ALG_TYPE_DIGEST) { ti->error = PFX "Expected digest algorithm for ESSIV hash"; crypto_free_tfm(hash_tfm); return -EINVAL; } saltsize = crypto_tfm_alg_digestsize(hash_tfm); salt = kmalloc(saltsize, GFP_KERNEL); if (salt == NULL) { ti->error = PFX "Error kmallocing salt storage in ESSIV"; crypto_free_tfm(hash_tfm); return -ENOMEM; } sg.page = virt_to_page(cc->key); sg.offset = offset_in_page(cc->key); sg.length = cc->key_size; crypto_digest_digest(hash_tfm, &sg, 1, salt); crypto_free_tfm(hash_tfm); /* Setup the essiv_tfm with the given salt */ essiv_tfm = crypto_alloc_tfm(crypto_tfm_alg_name(cc->tfm), CRYPTO_TFM_MODE_ECB); if (essiv_tfm == NULL) { ti->error = PFX "Error allocating crypto tfm for ESSIV"; kfree(salt); return -EINVAL; } if (crypto_tfm_alg_blocksize(essiv_tfm) != crypto_tfm_alg_ivsize(cc->tfm)) { ti->error = PFX "Block size of ESSIV cipher does " "not match IV size of block cipher"; crypto_free_tfm(essiv_tfm); kfree(salt); return -EINVAL; } if (crypto_cipher_setkey(essiv_tfm, salt, saltsize) < 0) { ti->error = PFX "Failed to set key for ESSIV cipher"; crypto_free_tfm(essiv_tfm); kfree(salt); return -EINVAL; } kfree(salt); cc->iv_gen_private = (void *)essiv_tfm; return 0; } static void crypt_iv_essiv_dtr(struct crypt_config *cc) { crypto_free_tfm((struct crypto_tfm *)cc->iv_gen_private); cc->iv_gen_private = NULL; } static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector) { struct scatterlist sg = { NULL, }; memset(iv, 0, cc->iv_size); *(u64 *)iv = cpu_to_le64(sector); sg.page = virt_to_page(iv); sg.offset = offset_in_page(iv); sg.length = cc->iv_size; crypto_cipher_encrypt((struct crypto_tfm *)cc->iv_gen_private, &sg, &sg, cc->iv_size); return 0; } static struct crypt_iv_operations crypt_iv_plain_ops = { .generator = crypt_iv_plain_gen }; static struct crypt_iv_operations crypt_iv_essiv_ops = { .ctr = crypt_iv_essiv_ctr, .dtr = crypt_iv_essiv_dtr, .generator = crypt_iv_essiv_gen }; static inline int crypt_convert_scatterlist(struct crypt_config *cc, struct scatterlist *out, struct scatterlist *in, unsigned int length, int write, sector_t sector) { u8 iv[cc->iv_size]; int r; if (cc->iv_gen_ops) { r = cc->iv_gen_ops->generator(cc, iv, sector); if (r < 0) return r; if (write) r = crypto_cipher_encrypt_iv(cc->tfm, out, in, length, iv); else r = crypto_cipher_decrypt_iv(cc->tfm, out, in, length, iv); } else { if (write) r = crypto_cipher_encrypt(cc->tfm, out, in, length); else r = crypto_cipher_decrypt(cc->tfm, out, in, length); } return r; } static void crypt_convert_init(struct crypt_config *cc, struct convert_context *ctx, struct bio *bio_out, struct bio *bio_in, sector_t sector, int write) { ctx->bio_in = bio_in; ctx->bio_out = bio_out; ctx->offset_in = 0; ctx->offset_out = 0; ctx->idx_in = bio_in ? bio_in->bi_idx : 0; ctx->idx_out = bio_out ? bio_out->bi_idx : 0; ctx->sector = sector + cc->iv_offset; ctx->write = write; } /* * Encrypt / decrypt data from one bio to another one (can be the same one) */ static int crypt_convert(struct crypt_config *cc, struct convert_context *ctx) { int r = 0; while(ctx->idx_in < ctx->bio_in->bi_vcnt && ctx->idx_out < ctx->bio_out->bi_vcnt) { struct bio_vec *bv_in = bio_iovec_idx(ctx->bio_in, ctx->idx_in); struct bio_vec *bv_out = bio_iovec_idx(ctx->bio_out, ctx->idx_out); struct scatterlist sg_in = { .page = bv_in->bv_page, .offset = bv_in->bv_offset + ctx->offset_in, .length = 1 << SECTOR_SHIFT }; struct scatterlist sg_out = { .page = bv_out->bv_page, .offset = bv_out->bv_offset + ctx->offset_out, .length = 1 << SECTOR_SHIFT }; ctx->offset_in += sg_in.length; if (ctx->offset_in >= bv_in->bv_len) { ctx->offset_in = 0; ctx->idx_in++; } ctx->offset_out += sg_out.length; if (ctx->offset_out >= bv_out->bv_len) { ctx->offset_out = 0; ctx->idx_out++; } r = crypt_convert_scatterlist(cc, &sg_out, &sg_in, sg_in.length, ctx->write, ctx->sector); if (r < 0) break; ctx->sector++; } return r; } /* * Generate a new unfragmented bio with the given size * This should never violate the device limitations * May return a smaller bio when running out of pages */ static struct bio * crypt_alloc_buffer(struct crypt_config *cc, unsigned int size, struct bio *base_bio, unsigned int *bio_vec_idx) { struct bio *bio; unsigned int nr_iovecs = (size + PAGE_SIZE - 1) >> PAGE_SHIFT; int gfp_mask = GFP_NOIO | __GFP_HIGHMEM; unsigned long flags = current->flags; unsigned int i; /* * Tell VM to act less aggressively and fail earlier. * This is not necessary but increases throughput. * FIXME: Is this really intelligent? */ current->flags &= ~PF_MEMALLOC; if (base_bio) bio = bio_clone(base_bio, GFP_NOIO); else bio = bio_alloc(GFP_NOIO, nr_iovecs); if (!bio) { if (flags & PF_MEMALLOC) current->flags |= PF_MEMALLOC; return NULL; } /* if the last bio was not complete, continue where that one ended */ bio->bi_idx = *bio_vec_idx; bio->bi_vcnt = *bio_vec_idx; bio->bi_size = 0; bio->bi_flags &= ~(1 << BIO_SEG_VALID); /* bio->bi_idx pages have already been allocated */ size -= bio->bi_idx * PAGE_SIZE; for(i = bio->bi_idx; i < nr_iovecs; i++) { struct bio_vec *bv = bio_iovec_idx(bio, i); bv->bv_page = mempool_alloc(cc->page_pool, gfp_mask); if (!bv->bv_page) break; /* * if additional pages cannot be allocated without waiting, * return a partially allocated bio, the caller will then try * to allocate additional bios while submitting this partial bio */ if ((i - bio->bi_idx) == (MIN_BIO_PAGES - 1)) gfp_mask = (gfp_mask | __GFP_NOWARN) & ~__GFP_WAIT; bv->bv_offset = 0; if (size > PAGE_SIZE) bv->bv_len = PAGE_SIZE; else bv->bv_len = size; bio->bi_size += bv->bv_len; bio->bi_vcnt++; size -= bv->bv_len; } if (flags & PF_MEMALLOC) current->flags |= PF_MEMALLOC; if (!bio->bi_size) { bio_put(bio); return NULL; } /* * Remember the last bio_vec allocated to be able * to correctly continue after the splitting. */ *bio_vec_idx = bio->bi_vcnt; return bio; } static void crypt_free_buffer_pages(struct crypt_config *cc, struct bio *bio, unsigned int bytes) { unsigned int i, start, end; struct bio_vec *bv; /* * This is ugly, but Jens Axboe thinks that using bi_idx in the * endio function is too dangerous at the moment, so I calculate the * correct position using bi_vcnt and bi_size. * The bv_offset and bv_len fields might already be modified but we * know that we always allocated whole pages. * A fix to the bi_idx issue in the kernel is in the works, so * we will hopefully be able to revert to the cleaner solution soon. */ i = bio->bi_vcnt - 1; bv = bio_iovec_idx(bio, i); end = (i << PAGE_SHIFT) + (bv->bv_offset + bv->bv_len) - bio->bi_size; start = end - bytes; start >>= PAGE_SHIFT; if (!bio->bi_size) end = bio->bi_vcnt; else end >>= PAGE_SHIFT; for(i = start; i < end; i++) { bv = bio_iovec_idx(bio, i); BUG_ON(!bv->bv_page); mempool_free(bv->bv_page, cc->page_pool); bv->bv_page = NULL; } } /* * One of the bios was finished. Check for completion of * the whole request and correctly clean up the buffer. */ static void dec_pending(struct crypt_io *io, int error) { struct crypt_config *cc = (struct crypt_config *) io->target->private; if (error < 0) io->error = error; if (!atomic_dec_and_test(&io->pending)) return; if (io->first_clone) bio_put(io->first_clone); bio_endio(io->bio, io->bio->bi_size, io->error); mempool_free(io, cc->io_pool); } /* * kcryptd: * * Needed because it would be very unwise to do decryption in an * interrupt context, so bios returning from read requests get * queued here. */ static struct workqueue_struct *_kcryptd_workqueue; static void kcryptd_do_work(void *data) { struct crypt_io *io = (struct crypt_io *) data; struct crypt_config *cc = (struct crypt_config *) io->target->private; struct convert_context ctx; int r; crypt_convert_init(cc, &ctx, io->bio, io->bio, io->bio->bi_sector - io->target->begin, 0); r = crypt_convert(cc, &ctx); dec_pending(io, r); } static void kcryptd_queue_io(struct crypt_io *io) { INIT_WORK(&io->work, kcryptd_do_work, io); queue_work(_kcryptd_workqueue, &io->work); } /* * Decode key from its hex representation */ static int crypt_decode_key(u8 *key, char *hex, unsigned int size) { char buffer[3]; char *endp; unsigned int i; buffer[2] = '\0'; for(i = 0; i < size; i++) { buffer[0] = *hex++; buffer[1] = *hex++; key[i] = (u8)simple_strtoul(buffer, &endp, 16); if (endp != &buffer[2]) return -EINVAL; } if (*hex != '\0') return -EINVAL; return 0; } /* * Encode key into its hex representation */ static void crypt_encode_key(char *hex, u8 *key, unsigned int size) { unsigned int i; for(i = 0; i < size; i++) { sprintf(hex, "%02x", *key); hex += 2; key++; } } /* * Construct an encryption mapping: * <cipher> <key> <iv_offset> <dev_path> <start> */ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv) { struct crypt_config *cc; struct crypto_tfm *tfm; char *tmp; char *cipher; char *chainmode; char *ivmode; char *ivopts; unsigned int crypto_flags; unsigned int key_size; if (argc != 5) { ti->error = PFX "Not enough arguments"; return -EINVAL; } tmp = argv[0]; cipher = strsep(&tmp, "-"); chainmode = strsep(&tmp, "-"); ivopts = strsep(&tmp, "-"); ivmode = strsep(&ivopts, ":"); if (tmp) DMWARN(PFX "Unexpected additional cipher options"); key_size = strlen(argv[1]) >> 1; cc = kmalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL); if (cc == NULL) { ti->error = PFX "Cannot allocate transparent encryption context"; return -ENOMEM; } cc->key_size = key_size; if ((!key_size && strcmp(argv[1], "-") != 0) || (key_size && crypt_decode_key(cc->key, argv[1], key_size) < 0)) { ti->error = PFX "Error decoding key"; goto bad1; } /* Compatiblity mode for old dm-crypt cipher strings */ if (!chainmode || (strcmp(chainmode, "plain") == 0 && !ivmode)) { chainmode = "cbc"; ivmode = "plain"; } /* Choose crypto_flags according to chainmode */ if (strcmp(chainmode, "cbc") == 0) crypto_flags = CRYPTO_TFM_MODE_CBC; else if (strcmp(chainmode, "ecb") == 0) crypto_flags = CRYPTO_TFM_MODE_ECB; else { ti->error = PFX "Unknown chaining mode"; goto bad1; } if (crypto_flags != CRYPTO_TFM_MODE_ECB && !ivmode) { ti->error = PFX "This chaining mode requires an IV mechanism"; goto bad1; } tfm = crypto_alloc_tfm(cipher, crypto_flags); if (!tfm) { ti->error = PFX "Error allocating crypto tfm"; goto bad1; } if (crypto_tfm_alg_type(tfm) != CRYPTO_ALG_TYPE_CIPHER) { ti->error = PFX "Expected cipher algorithm"; goto bad2; } cc->tfm = tfm; /* * Choose ivmode. Valid modes: "plain", "essiv:<esshash>". * See comments at iv code */ if (ivmode == NULL) cc->iv_gen_ops = NULL; else if (strcmp(ivmode, "plain") == 0) cc->iv_gen_ops = &crypt_iv_plain_ops; else if (strcmp(ivmode, "essiv") == 0) cc->iv_gen_ops = &crypt_iv_essiv_ops; else { ti->error = PFX "Invalid IV mode"; goto bad2; } if (cc->iv_gen_ops && cc->iv_gen_ops->ctr && cc->iv_gen_ops->ctr(cc, ti, ivopts) < 0) goto bad2; if (tfm->crt_cipher.cit_decrypt_iv && tfm->crt_cipher.cit_encrypt_iv) /* at least a 64 bit sector number should fit in our buffer */ cc->iv_size = max(crypto_tfm_alg_ivsize(tfm), (unsigned int)(sizeof(u64) / sizeof(u8))); else { cc->iv_size = 0; if (cc->iv_gen_ops) { DMWARN(PFX "Selected cipher does not support IVs"); if (cc->iv_gen_ops->dtr) cc->iv_gen_ops->dtr(cc); cc->iv_gen_ops = NULL; } } cc->io_pool = mempool_create(MIN_IOS, mempool_alloc_slab, mempool_free_slab, _crypt_io_pool); if (!cc->io_pool) { ti->error = PFX "Cannot allocate crypt io mempool"; goto bad3; } cc->page_pool = mempool_create(MIN_POOL_PAGES, mempool_alloc_page, mempool_free_page, NULL); if (!cc->page_pool) { ti->error = PFX "Cannot allocate page mempool"; goto bad4; } if (tfm->crt_cipher.cit_setkey(tfm, cc->key, key_size) < 0) { ti->error = PFX "Error setting key"; goto bad5; } if (sscanf(argv[2], SECTOR_FORMAT, &cc->iv_offset) != 1) { ti->error = PFX "Invalid iv_offset sector"; goto bad5; } if (sscanf(argv[4], SECTOR_FORMAT, &cc->start) != 1) { ti->error = PFX "Invalid device sector"; goto bad5; } if (dm_get_device(ti, argv[3], cc->start, ti->len, dm_table_get_mode(ti->table), &cc->dev)) { ti->error = PFX "Device lookup failed"; goto bad5; } if (ivmode && cc->iv_gen_ops) { if (ivopts) *(ivopts - 1) = ':'; cc->iv_mode = kmalloc(strlen(ivmode) + 1, GFP_KERNEL); if (!cc->iv_mode) { ti->error = PFX "Error kmallocing iv_mode string"; goto bad5; } strcpy(cc->iv_mode, ivmode); } else cc->iv_mode = NULL; ti->private = cc; return 0; bad5: mempool_destroy(cc->page_pool); bad4: mempool_destroy(cc->io_pool); bad3: if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) cc->iv_gen_ops->dtr(cc); bad2: crypto_free_tfm(tfm); bad1: kfree(cc); return -EINVAL; } static void crypt_dtr(struct dm_target *ti) { struct crypt_config *cc = (struct crypt_config *) ti->private; mempool_destroy(cc->page_pool); mempool_destroy(cc->io_pool); if (cc->iv_mode) kfree(cc->iv_mode); if (cc->iv_gen_ops && cc->iv_gen_ops->dtr) cc->iv_gen_ops->dtr(cc); crypto_free_tfm(cc->tfm); dm_put_device(ti, cc->dev); kfree(cc); } static int crypt_endio(struct bio *bio, unsigned int done, int error) { struct crypt_io *io = (struct crypt_io *) bio->bi_private; struct crypt_config *cc = (struct crypt_config *) io->target->private; if (bio_data_dir(bio) == WRITE) { /* * free the processed pages, even if * it's only a partially completed write */ crypt_free_buffer_pages(cc, bio, done); } if (bio->bi_size) return 1; bio_put(bio); /* * successful reads are decrypted by the worker thread */ if ((bio_data_dir(bio) == READ) && bio_flagged(bio, BIO_UPTODATE)) { kcryptd_queue_io(io); return 0; } dec_pending(io, error); return error; } static inline struct bio * crypt_clone(struct crypt_config *cc, struct crypt_io *io, struct bio *bio, sector_t sector, unsigned int *bvec_idx, struct convert_context *ctx) { struct bio *clone; if (bio_data_dir(bio) == WRITE) { clone = crypt_alloc_buffer(cc, bio->bi_size, io->first_clone, bvec_idx); if (clone) { ctx->bio_out = clone; if (crypt_convert(cc, ctx) < 0) { crypt_free_buffer_pages(cc, clone, clone->bi_size); bio_put(clone); return NULL; } } } else { /* * The block layer might modify the bvec array, so always * copy the required bvecs because we need the original * one in order to decrypt the whole bio data *afterwards*. */ clone = bio_alloc(GFP_NOIO, bio_segments(bio)); if (clone) { clone->bi_idx = 0; clone->bi_vcnt = bio_segments(bio); clone->bi_size = bio->bi_size; memcpy(clone->bi_io_vec, bio_iovec(bio), sizeof(struct bio_vec) * clone->bi_vcnt); } } if (!clone) return NULL; clone->bi_private = io; clone->bi_end_io = crypt_endio; clone->bi_bdev = cc->dev->bdev; clone->bi_sector = cc->start + sector; clone->bi_rw = bio->bi_rw; return clone; } static int crypt_map(struct dm_target *ti, struct bio *bio, union map_info *map_context) { struct crypt_config *cc = (struct crypt_config *) ti->private; struct crypt_io *io = mempool_alloc(cc->io_pool, GFP_NOIO); struct convert_context ctx; struct bio *clone; unsigned int remaining = bio->bi_size; sector_t sector = bio->bi_sector - ti->begin; unsigned int bvec_idx = 0; io->target = ti; io->bio = bio; io->first_clone = NULL; io->error = 0; atomic_set(&io->pending, 1); /* hold a reference */ if (bio_data_dir(bio) == WRITE) crypt_convert_init(cc, &ctx, NULL, bio, sector, 1); /* * The allocated buffers can be smaller than the whole bio, * so repeat the whole process until all the data can be handled. */ while (remaining) { clone = crypt_clone(cc, io, bio, sector, &bvec_idx, &ctx); if (!clone) goto cleanup; if (!io->first_clone) { /* * hold a reference to the first clone, because it * holds the bio_vec array and that can't be freed * before all other clones are released */ bio_get(clone); io->first_clone = clone; } atomic_inc(&io->pending); remaining -= clone->bi_size; sector += bio_sectors(clone); generic_make_request(clone); /* out of memory -> run queues */ if (remaining) blk_congestion_wait(bio_data_dir(clone), HZ/100); } /* drop reference, clones could have returned before we reach this */ dec_pending(io, 0); return 0; cleanup: if (io->first_clone) { dec_pending(io, -ENOMEM); return 0; } /* if no bio has been dispatched yet, we can directly return the error */ mempool_free(io, cc->io_pool); return -ENOMEM; } static int crypt_status(struct dm_target *ti, status_type_t type, char *result, unsigned int maxlen) { struct crypt_config *cc = (struct crypt_config *) ti->private; const char *cipher; const char *chainmode = NULL; unsigned int sz = 0; switch (type) { case STATUSTYPE_INFO: result[0] = '\0'; break; case STATUSTYPE_TABLE: cipher = crypto_tfm_alg_name(cc->tfm); switch(cc->tfm->crt_cipher.cit_mode) { case CRYPTO_TFM_MODE_CBC: chainmode = "cbc"; break; case CRYPTO_TFM_MODE_ECB: chainmode = "ecb"; break; default: BUG(); } if (cc->iv_mode) DMEMIT("%s-%s-%s ", cipher, chainmode, cc->iv_mode); else DMEMIT("%s-%s ", cipher, chainmode); if (cc->key_size > 0) { if ((maxlen - sz) < ((cc->key_size << 1) + 1)) return -ENOMEM; crypt_encode_key(result + sz, cc->key, cc->key_size); sz += cc->key_size << 1; } else { if (sz >= maxlen) return -ENOMEM; result[sz++] = '-'; } DMEMIT(" " SECTOR_FORMAT " %s " SECTOR_FORMAT, cc->iv_offset, cc->dev->name, cc->start); break; } return 0; } static struct target_type crypt_target = { .name = "crypt", .version= {1, 1, 0}, .module = THIS_MODULE, .ctr = crypt_ctr, .dtr = crypt_dtr, .map = crypt_map, .status = crypt_status, }; static int __init dm_crypt_init(void) { int r; _crypt_io_pool = kmem_cache_create("dm-crypt_io", sizeof(struct crypt_io), 0, 0, NULL, NULL); if (!_crypt_io_pool) return -ENOMEM; _kcryptd_workqueue = create_workqueue("kcryptd"); if (!_kcryptd_workqueue) { r = -ENOMEM; DMERR(PFX "couldn't create kcryptd"); goto bad1; } r = dm_register_target(&crypt_target); if (r < 0) { DMERR(PFX "register failed %d", r); goto bad2; } return 0; bad2: destroy_workqueue(_kcryptd_workqueue); bad1: kmem_cache_destroy(_crypt_io_pool); return r; } static void __exit dm_crypt_exit(void) { int r = dm_unregister_target(&crypt_target); if (r < 0) DMERR(PFX "unregister failed %d", r); destroy_workqueue(_kcryptd_workqueue); kmem_cache_destroy(_crypt_io_pool); } module_init(dm_crypt_init); module_exit(dm_crypt_exit); MODULE_AUTHOR("Christophe Saout <christophe@saout.de>"); MODULE_DESCRIPTION(DM_NAME " target for transparent encryption / decryption"); MODULE_LICENSE("GPL");