1 files changed, 514 insertions, 112 deletions

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 368e8e98f705..c8827ffd85bb 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -18,10 +18,14 @@
 #include <linux/crypto.h>
 #include <linux/workqueue.h>
 #include <linux/backing-dev.h>
+#include <linux/percpu.h>
 #include <asm/atomic.h>
 #include <linux/scatterlist.h>
 #include <asm/page.h>
 #include <asm/unaligned.h>
+#include <crypto/hash.h>
+#include <crypto/md5.h>
+#include <crypto/algapi.h>
 
 #include <linux/device-mapper.h>
 
@@ -63,6 +67,7 @@ struct dm_crypt_request {
         struct convert_context *ctx;
         struct scatterlist sg_in;
         struct scatterlist sg_out;
+        sector_t iv_sector;
 };
 
 struct crypt_config;
@@ -73,11 +78,13 @@ struct crypt_iv_operations {
         void (*dtr)(struct crypt_config *cc);
         int (*init)(struct crypt_config *cc);
         int (*wipe)(struct crypt_config *cc);
-        int (*generator)(struct crypt_config *cc, u8 *iv, sector_t sector);
+        int (*generator)(struct crypt_config *cc, u8 *iv,
+                         struct dm_crypt_request *dmreq);
+        int (*post)(struct crypt_config *cc, u8 *iv,
+                    struct dm_crypt_request *dmreq);
 };
 
 struct iv_essiv_private {
-        struct crypto_cipher *tfm;
         struct crypto_hash *hash_tfm;
         u8 *salt;
 };
@@ -86,11 +93,32 @@ struct iv_benbi_private {
         int shift;
 };
 
+#define LMK_SEED_SIZE 64 /* hash + 0 */
+struct iv_lmk_private {
+        struct crypto_shash *hash_tfm;
+        u8 *seed;
+};
+
 /*
  * Crypt: maps a linear range of a block device
  * and encrypts / decrypts at the same time.
  */
 enum flags { DM_CRYPT_SUSPENDED, DM_CRYPT_KEY_VALID };
+
+/*
+ * Duplicated per-CPU state for cipher.
+ */
+struct crypt_cpu {
+        struct ablkcipher_request *req;
+        /* ESSIV: struct crypto_cipher *essiv_tfm */
+        void *iv_private;
+        struct crypto_ablkcipher *tfms[0];
+};
+
+/*
+ * The fields in here must be read only after initialization,
+ * changing state should be in crypt_cpu.
+ */
 struct crypt_config {
         struct dm_dev *dev;
         sector_t start;
@@ -108,17 +136,25 @@ struct crypt_config {
         struct workqueue_struct *crypt_queue;
 
         char *cipher;
-        char *cipher_mode;
+        char *cipher_string;
 
         struct crypt_iv_operations *iv_gen_ops;
         union {
                 struct iv_essiv_private essiv;
                 struct iv_benbi_private benbi;
+                struct iv_lmk_private lmk;
         } iv_gen_private;
         sector_t iv_offset;
         unsigned int iv_size;
 
         /*
+         * Duplicated per cpu state. Access through
+         * per_cpu_ptr() only.
+         */
+        struct crypt_cpu __percpu *cpu;
+        unsigned tfms_count;
+
+        /*
          * Layout of each crypto request:
          *
          *   struct ablkcipher_request
@@ -132,11 +168,10 @@ struct crypt_config {
          * correctly aligned.
          */
         unsigned int dmreq_start;
-        struct ablkcipher_request *req;
 
-        struct crypto_ablkcipher *tfm;
         unsigned long flags;
         unsigned int key_size;
+        unsigned int key_parts;
         u8 key[0];
 };
 
@@ -148,6 +183,20 @@ static struct kmem_cache *_crypt_io_pool;
 
 static void clone_init(struct dm_crypt_io *, struct bio *);
 static void kcryptd_queue_crypt(struct dm_crypt_io *io);
+static u8 *iv_of_dmreq(struct crypt_config *cc, struct dm_crypt_request *dmreq);
+
+static struct crypt_cpu *this_crypt_config(struct crypt_config *cc)
+{
+        return this_cpu_ptr(cc->cpu);
+}
+
+/*
+ * Use this to access cipher attributes that are the same for each CPU.
+ */
+static struct crypto_ablkcipher *any_tfm(struct crypt_config *cc)
+{
+        return __this_cpu_ptr(cc->cpu)->tfms[0];
+}
 
 /*
  * Different IV generation algorithms:
@@ -168,23 +217,38 @@ static void kcryptd_queue_crypt(struct dm_crypt_io *io);
  * null: the initial vector is always zero.  Provides compatibility with
  *       obsolete loop_fish2 devices.  Do not use for new devices.
  *
+ * lmk:  Compatible implementation of the block chaining mode used
+ *       by the Loop-AES block device encryption system
+ *       designed by Jari Ruusu. See http://loop-aes.sourceforge.net/
+ *       It operates on full 512 byte sectors and uses CBC
+ *       with an IV derived from the sector number, the data and
+ *       optionally extra IV seed.
+ *       This means that after decryption the first block
+ *       of sector must be tweaked according to decrypted data.
+ *       Loop-AES can use three encryption schemes:
+ *         version 1: is plain aes-cbc mode
+ *         version 2: uses 64 multikey scheme with lmk IV generator
+ *         version 3: the same as version 2 with additional IV seed
+ *                   (it uses 65 keys, last key is used as IV seed)
+ *
  * 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)
+static int crypt_iv_plain_gen(struct crypt_config *cc, u8 *iv,
+                              struct dm_crypt_request *dmreq)
 {
         memset(iv, 0, cc->iv_size);
-        *(u32 *)iv = cpu_to_le32(sector & 0xffffffff);
+        *(u32 *)iv = cpu_to_le32(dmreq->iv_sector & 0xffffffff);
 
         return 0;
 }
 
 static int crypt_iv_plain64_gen(struct crypt_config *cc, u8 *iv,
-                                sector_t sector)
+                                struct dm_crypt_request *dmreq)
 {
         memset(iv, 0, cc->iv_size);
-        *(u64 *)iv = cpu_to_le64(sector);
+        *(u64 *)iv = cpu_to_le64(dmreq->iv_sector);
 
         return 0;
 }
@@ -195,7 +259,8 @@ static int crypt_iv_essiv_init(struct crypt_config *cc)
         struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
         struct hash_desc desc;
         struct scatterlist sg;
-        int err;
+        struct crypto_cipher *essiv_tfm;
+        int err, cpu;
 
         sg_init_one(&sg, cc->key, cc->key_size);
         desc.tfm = essiv->hash_tfm;
@@ -205,8 +270,16 @@ static int crypt_iv_essiv_init(struct crypt_config *cc)
         if (err)
                 return err;
 
-        return crypto_cipher_setkey(essiv->tfm, essiv->salt,
+        for_each_possible_cpu(cpu) {
+                essiv_tfm = per_cpu_ptr(cc->cpu, cpu)->iv_private,
+
+                err = crypto_cipher_setkey(essiv_tfm, essiv->salt,
                                     crypto_hash_digestsize(essiv->hash_tfm));
+                if (err)
+                        return err;
+        }
+
+        return 0;
 }
 
 /* Wipe salt and reset key derived from volume key */
@@ -214,24 +287,76 @@ static int crypt_iv_essiv_wipe(struct crypt_config *cc)
 {
         struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
         unsigned salt_size = crypto_hash_digestsize(essiv->hash_tfm);
+        struct crypto_cipher *essiv_tfm;
+        int cpu, r, err = 0;
 
         memset(essiv->salt, 0, salt_size);
 
-        return crypto_cipher_setkey(essiv->tfm, essiv->salt, salt_size);
+        for_each_possible_cpu(cpu) {
+                essiv_tfm = per_cpu_ptr(cc->cpu, cpu)->iv_private;
+                r = crypto_cipher_setkey(essiv_tfm, essiv->salt, salt_size);
+                if (r)
+                        err = r;
+        }
+
+        return err;
+}
+
+/* Set up per cpu cipher state */
+static struct crypto_cipher *setup_essiv_cpu(struct crypt_config *cc,
+                                             struct dm_target *ti,
+                                             u8 *salt, unsigned saltsize)
+{
+        struct crypto_cipher *essiv_tfm;
+        int err;
+
+        /* Setup the essiv_tfm with the given salt */
+        essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
+        if (IS_ERR(essiv_tfm)) {
+                ti->error = "Error allocating crypto tfm for ESSIV";
+                return essiv_tfm;
+        }
+
+        if (crypto_cipher_blocksize(essiv_tfm) !=
+            crypto_ablkcipher_ivsize(any_tfm(cc))) {
+                ti->error = "Block size of ESSIV cipher does "
+                            "not match IV size of block cipher";
+                crypto_free_cipher(essiv_tfm);
+                return ERR_PTR(-EINVAL);
+        }
+
+        err = crypto_cipher_setkey(essiv_tfm, salt, saltsize);
+        if (err) {
+                ti->error = "Failed to set key for ESSIV cipher";
+                crypto_free_cipher(essiv_tfm);
+                return ERR_PTR(err);
+        }
+
+        return essiv_tfm;
 }
 
 static void crypt_iv_essiv_dtr(struct crypt_config *cc)
 {
+        int cpu;
+        struct crypt_cpu *cpu_cc;
+        struct crypto_cipher *essiv_tfm;
         struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
 
-        crypto_free_cipher(essiv->tfm);
-        essiv->tfm = NULL;
-
         crypto_free_hash(essiv->hash_tfm);
         essiv->hash_tfm = NULL;
 
         kzfree(essiv->salt);
         essiv->salt = NULL;
+
+        for_each_possible_cpu(cpu) {
+                cpu_cc = per_cpu_ptr(cc->cpu, cpu);
+                essiv_tfm = cpu_cc->iv_private;
+
+                if (essiv_tfm)
+                        crypto_free_cipher(essiv_tfm);
+
+                cpu_cc->iv_private = NULL;
+        }
 }
 
 static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
@@ -240,7 +365,7 @@ static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
         struct crypto_cipher *essiv_tfm = NULL;
         struct crypto_hash *hash_tfm = NULL;
         u8 *salt = NULL;
-        int err;
+        int err, cpu;
 
         if (!opts) {
                 ti->error = "Digest algorithm missing for ESSIV mode";
@@ -262,48 +387,44 @@ static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
                 goto bad;
         }
 
-        /* Allocate essiv_tfm */
-        essiv_tfm = crypto_alloc_cipher(cc->cipher, 0, CRYPTO_ALG_ASYNC);
-        if (IS_ERR(essiv_tfm)) {
-                ti->error = "Error allocating crypto tfm for ESSIV";
-                err = PTR_ERR(essiv_tfm);
-                goto bad;
-        }
-        if (crypto_cipher_blocksize(essiv_tfm) !=
-            crypto_ablkcipher_ivsize(cc->tfm)) {
-                ti->error = "Block size of ESSIV cipher does "
-                            "not match IV size of block cipher";
-                err = -EINVAL;
-                goto bad;
-        }
-
         cc->iv_gen_private.essiv.salt = salt;
-        cc->iv_gen_private.essiv.tfm = essiv_tfm;
         cc->iv_gen_private.essiv.hash_tfm = hash_tfm;
 
+        for_each_possible_cpu(cpu) {
+                essiv_tfm = setup_essiv_cpu(cc, ti, salt,
+                                        crypto_hash_digestsize(hash_tfm));
+                if (IS_ERR(essiv_tfm)) {
+                        crypt_iv_essiv_dtr(cc);
+                        return PTR_ERR(essiv_tfm);
+                }
+                per_cpu_ptr(cc->cpu, cpu)->iv_private = essiv_tfm;
+        }
+
         return 0;
 
 bad:
-        if (essiv_tfm && !IS_ERR(essiv_tfm))
-                crypto_free_cipher(essiv_tfm);
         if (hash_tfm && !IS_ERR(hash_tfm))
                 crypto_free_hash(hash_tfm);
         kfree(salt);
         return err;
 }
 
-static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
+static int crypt_iv_essiv_gen(struct crypt_config *cc, u8 *iv,
+                              struct dm_crypt_request *dmreq)
 {
+        struct crypto_cipher *essiv_tfm = this_crypt_config(cc)->iv_private;
+
         memset(iv, 0, cc->iv_size);
-        *(u64 *)iv = cpu_to_le64(sector);
-        crypto_cipher_encrypt_one(cc->iv_gen_private.essiv.tfm, iv, iv);
+        *(u64 *)iv = cpu_to_le64(dmreq->iv_sector);
+        crypto_cipher_encrypt_one(essiv_tfm, iv, iv);
+
         return 0;
 }
 
 static int crypt_iv_benbi_ctr(struct crypt_config *cc, struct dm_target *ti,
                               const char *opts)
 {
-        unsigned bs = crypto_ablkcipher_blocksize(cc->tfm);
+        unsigned bs = crypto_ablkcipher_blocksize(any_tfm(cc));
         int log = ilog2(bs);
 
         /* we need to calculate how far we must shift the sector count
@@ -328,25 +449,177 @@ static void crypt_iv_benbi_dtr(struct crypt_config *cc)
 {
 }
 
-static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
+static int crypt_iv_benbi_gen(struct crypt_config *cc, u8 *iv,
+                              struct dm_crypt_request *dmreq)
 {
         __be64 val;
 
         memset(iv, 0, cc->iv_size - sizeof(u64)); /* rest is cleared below */
 
-        val = cpu_to_be64(((u64)sector << cc->iv_gen_private.benbi.shift) + 1);
+        val = cpu_to_be64(((u64)dmreq->iv_sector << cc->iv_gen_private.benbi.shift) + 1);
         put_unaligned(val, (__be64 *)(iv + cc->iv_size - sizeof(u64)));
 
         return 0;
 }
 
-static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv, sector_t sector)
+static int crypt_iv_null_gen(struct crypt_config *cc, u8 *iv,
+                             struct dm_crypt_request *dmreq)
 {
         memset(iv, 0, cc->iv_size);
 
         return 0;
 }
 
+static void crypt_iv_lmk_dtr(struct crypt_config *cc)
+{
+        struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
+
+        if (lmk->hash_tfm && !IS_ERR(lmk->hash_tfm))
+                crypto_free_shash(lmk->hash_tfm);
+        lmk->hash_tfm = NULL;
+
+        kzfree(lmk->seed);
+        lmk->seed = NULL;
+}
+
+static int crypt_iv_lmk_ctr(struct crypt_config *cc, struct dm_target *ti,
+                            const char *opts)
+{
+        struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
+
+        lmk->hash_tfm = crypto_alloc_shash("md5", 0, 0);
+        if (IS_ERR(lmk->hash_tfm)) {
+                ti->error = "Error initializing LMK hash";
+                return PTR_ERR(lmk->hash_tfm);
+        }
+
+        /* No seed in LMK version 2 */
+        if (cc->key_parts == cc->tfms_count) {
+                lmk->seed = NULL;
+                return 0;
+        }
+
+        lmk->seed = kzalloc(LMK_SEED_SIZE, GFP_KERNEL);
+        if (!lmk->seed) {
+                crypt_iv_lmk_dtr(cc);
+                ti->error = "Error kmallocing seed storage in LMK";
+                return -ENOMEM;
+        }
+
+        return 0;
+}
+
+static int crypt_iv_lmk_init(struct crypt_config *cc)
+{
+        struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
+        int subkey_size = cc->key_size / cc->key_parts;
+
+        /* LMK seed is on the position of LMK_KEYS + 1 key */
+        if (lmk->seed)
+                memcpy(lmk->seed, cc->key + (cc->tfms_count * subkey_size),
+                       crypto_shash_digestsize(lmk->hash_tfm));
+
+        return 0;
+}
+
+static int crypt_iv_lmk_wipe(struct crypt_config *cc)
+{
+        struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
+
+        if (lmk->seed)
+                memset(lmk->seed, 0, LMK_SEED_SIZE);
+
+        return 0;
+}
+
+static int crypt_iv_lmk_one(struct crypt_config *cc, u8 *iv,
+                            struct dm_crypt_request *dmreq,
+                            u8 *data)
+{
+        struct iv_lmk_private *lmk = &cc->iv_gen_private.lmk;
+        struct {
+                struct shash_desc desc;
+                char ctx[crypto_shash_descsize(lmk->hash_tfm)];
+        } sdesc;
+        struct md5_state md5state;
+        u32 buf[4];
+        int i, r;
+
+        sdesc.desc.tfm = lmk->hash_tfm;
+        sdesc.desc.flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+        r = crypto_shash_init(&sdesc.desc);
+        if (r)
+                return r;
+
+        if (lmk->seed) {
+                r = crypto_shash_update(&sdesc.desc, lmk->seed, LMK_SEED_SIZE);
+                if (r)
+                        return r;
+        }
+
+        /* Sector is always 512B, block size 16, add data of blocks 1-31 */
+        r = crypto_shash_update(&sdesc.desc, data + 16, 16 * 31);
+        if (r)
+                return r;
+
+        /* Sector is cropped to 56 bits here */
+        buf[0] = cpu_to_le32(dmreq->iv_sector & 0xFFFFFFFF);
+        buf[1] = cpu_to_le32((((u64)dmreq->iv_sector >> 32) & 0x00FFFFFF) | 0x80000000);
+        buf[2] = cpu_to_le32(4024);
+        buf[3] = 0;
+        r = crypto_shash_update(&sdesc.desc, (u8 *)buf, sizeof(buf));
+        if (r)
+                return r;
+
+        /* No MD5 padding here */
+        r = crypto_shash_export(&sdesc.desc, &md5state);
+        if (r)
+                return r;
+
+        for (i = 0; i < MD5_HASH_WORDS; i++)
+                __cpu_to_le32s(&md5state.hash[i]);
+        memcpy(iv, &md5state.hash, cc->iv_size);
+
+        return 0;
+}
+
+static int crypt_iv_lmk_gen(struct crypt_config *cc, u8 *iv,
+                            struct dm_crypt_request *dmreq)
+{
+        u8 *src;
+        int r = 0;
+
+        if (bio_data_dir(dmreq->ctx->bio_in) == WRITE) {
+                src = kmap_atomic(sg_page(&dmreq->sg_in), KM_USER0);
+                r = crypt_iv_lmk_one(cc, iv, dmreq, src + dmreq->sg_in.offset);
+                kunmap_atomic(src, KM_USER0);
+        } else
+                memset(iv, 0, cc->iv_size);
+
+        return r;
+}
+
+static int crypt_iv_lmk_post(struct crypt_config *cc, u8 *iv,
+                             struct dm_crypt_request *dmreq)
+{
+        u8 *dst;
+        int r;
+
+        if (bio_data_dir(dmreq->ctx->bio_in) == WRITE)
+                return 0;
+
+        dst = kmap_atomic(sg_page(&dmreq->sg_out), KM_USER0);
+        r = crypt_iv_lmk_one(cc, iv, dmreq, dst + dmreq->sg_out.offset);
+
+        /* Tweak the first block of plaintext sector */
+        if (!r)
+                crypto_xor(dst + dmreq->sg_out.offset, iv, cc->iv_size);
+
+        kunmap_atomic(dst, KM_USER0);
+        return r;
+}
+
 static struct crypt_iv_operations crypt_iv_plain_ops = {
         .generator = crypt_iv_plain_gen
 };
@@ -373,6 +646,15 @@ static struct crypt_iv_operations crypt_iv_null_ops = {
         .generator = crypt_iv_null_gen
 };
 
+static struct crypt_iv_operations crypt_iv_lmk_ops = {
+        .ctr       = crypt_iv_lmk_ctr,
+        .dtr       = crypt_iv_lmk_dtr,
+        .init      = crypt_iv_lmk_init,
+        .wipe      = crypt_iv_lmk_wipe,
+        .generator = crypt_iv_lmk_gen,
+        .post      = crypt_iv_lmk_post
+};
+
 static void crypt_convert_init(struct crypt_config *cc,
                                struct convert_context *ctx,
                                struct bio *bio_out, struct bio *bio_in,
@@ -400,6 +682,13 @@ static struct ablkcipher_request *req_of_dmreq(struct crypt_config *cc,
         return (struct ablkcipher_request *)((char *)dmreq - cc->dmreq_start);
 }
 
+static u8 *iv_of_dmreq(struct crypt_config *cc,
+                       struct dm_crypt_request *dmreq)
+{
+        return (u8 *)ALIGN((unsigned long)(dmreq + 1),
+                crypto_ablkcipher_alignmask(any_tfm(cc)) + 1);
+}
+
 static int crypt_convert_block(struct crypt_config *cc,
                                struct convert_context *ctx,
                                struct ablkcipher_request *req)
@@ -411,9 +700,9 @@ static int crypt_convert_block(struct crypt_config *cc,
         int r = 0;
 
         dmreq = dmreq_of_req(cc, req);
-        iv = (u8 *)ALIGN((unsigned long)(dmreq + 1),
-                         crypto_ablkcipher_alignmask(cc->tfm) + 1);
+        iv = iv_of_dmreq(cc, dmreq);
 
+        dmreq->iv_sector = ctx->sector;
         dmreq->ctx = ctx;
         sg_init_table(&dmreq->sg_in, 1);
         sg_set_page(&dmreq->sg_in, bv_in->bv_page, 1 << SECTOR_SHIFT,
@@ -436,7 +725,7 @@ static int crypt_convert_block(struct crypt_config *cc,
         }
 
         if (cc->iv_gen_ops) {
-                r = cc->iv_gen_ops->generator(cc, iv, ctx->sector);
+                r = cc->iv_gen_ops->generator(cc, iv, dmreq);
                 if (r < 0)
                         return r;
         }
@@ -449,21 +738,28 @@ static int crypt_convert_block(struct crypt_config *cc,
         else
                 r = crypto_ablkcipher_decrypt(req);
 
+        if (!r && cc->iv_gen_ops && cc->iv_gen_ops->post)
+                r = cc->iv_gen_ops->post(cc, iv, dmreq);
+
         return r;
 }
 
 static void kcryptd_async_done(struct crypto_async_request *async_req,
                                int error);
+
 static void crypt_alloc_req(struct crypt_config *cc,
                             struct convert_context *ctx)
 {
-        if (!cc->req)
-                cc->req = mempool_alloc(cc->req_pool, GFP_NOIO);
-        ablkcipher_request_set_tfm(cc->req, cc->tfm);
-        ablkcipher_request_set_callback(cc->req, CRYPTO_TFM_REQ_MAY_BACKLOG |
-                                        CRYPTO_TFM_REQ_MAY_SLEEP,
-                                        kcryptd_async_done,
-                                        dmreq_of_req(cc, cc->req));
+        struct crypt_cpu *this_cc = this_crypt_config(cc);
+        unsigned key_index = ctx->sector & (cc->tfms_count - 1);
+
+        if (!this_cc->req)
+                this_cc->req = mempool_alloc(cc->req_pool, GFP_NOIO);
+
+        ablkcipher_request_set_tfm(this_cc->req, this_cc->tfms[key_index]);
+        ablkcipher_request_set_callback(this_cc->req,
+            CRYPTO_TFM_REQ_MAY_BACKLOG | CRYPTO_TFM_REQ_MAY_SLEEP,
+            kcryptd_async_done, dmreq_of_req(cc, this_cc->req));
 }
 
 /*
@@ -472,6 +768,7 @@ static void crypt_alloc_req(struct crypt_config *cc,
 static int crypt_convert(struct crypt_config *cc,
                          struct convert_context *ctx)
 {
+        struct crypt_cpu *this_cc = this_crypt_config(cc);
         int r;
 
         atomic_set(&ctx->pending, 1);
@@ -483,7 +780,7 @@ static int crypt_convert(struct crypt_config *cc,
 
                 atomic_inc(&ctx->pending);
 
-                r = crypt_convert_block(cc, ctx, cc->req);
+                r = crypt_convert_block(cc, ctx, this_cc->req);
 
                 switch (r) {
                 /* async */
@@ -492,7 +789,7 @@ static int crypt_convert(struct crypt_config *cc,
                         INIT_COMPLETION(ctx->restart);
                         /* fall through*/
                 case -EINPROGRESS:
-                        cc->req = NULL;
+                        this_cc->req = NULL;
                         ctx->sector++;
                         continue;
 
@@ -651,6 +948,9 @@ static void crypt_dec_pending(struct dm_crypt_io *io)
  * They must be separated as otherwise the final stages could be
  * starved by new requests which can block in the first stages due
  * to memory allocation.
+ *
+ * The work is done per CPU global for all dm-crypt instances.
+ * They should not depend on each other and do not block.
  */
 static void crypt_endio(struct bio *clone, int error)
 {
@@ -691,25 +991,22 @@ static void clone_init(struct dm_crypt_io *io, struct bio *clone)
         clone->bi_destructor = dm_crypt_bio_destructor;
 }
 
-static void kcryptd_io_read(struct dm_crypt_io *io)
+static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
 {
         struct crypt_config *cc = io->target->private;
         struct bio *base_bio = io->base_bio;
         struct bio *clone;
 
-        crypt_inc_pending(io);
-
         /*
          * 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_bioset(GFP_NOIO, bio_segments(base_bio), cc->bs);
-        if (unlikely(!clone)) {
-                io->error = -ENOMEM;
-                crypt_dec_pending(io);
-                return;
-        }
+        clone = bio_alloc_bioset(gfp, bio_segments(base_bio), cc->bs);
+        if (!clone)
+                return 1;
+
+        crypt_inc_pending(io);
 
         clone_init(io, clone);
         clone->bi_idx = 0;
@@ -720,6 +1017,7 @@ static void kcryptd_io_read(struct dm_crypt_io *io)
                sizeof(struct bio_vec) * clone->bi_vcnt);
 
         generic_make_request(clone);
+        return 0;
 }
 
 static void kcryptd_io_write(struct dm_crypt_io *io)
@@ -732,9 +1030,12 @@ static void kcryptd_io(struct work_struct *work)
 {
         struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
 
-        if (bio_data_dir(io->base_bio) == READ)
-                kcryptd_io_read(io);
-        else
+        if (bio_data_dir(io->base_bio) == READ) {
+                crypt_inc_pending(io);
+                if (kcryptd_io_read(io, GFP_NOIO))
+                        io->error = -ENOMEM;
+                crypt_dec_pending(io);
+        } else
                 kcryptd_io_write(io);
 }
 
@@ -901,6 +1202,9 @@ static void kcryptd_async_done(struct crypto_async_request *async_req,
                 return;
         }
 
+        if (!error && cc->iv_gen_ops && cc->iv_gen_ops->post)
+                error = cc->iv_gen_ops->post(cc, iv_of_dmreq(cc, dmreq), dmreq);
+
         mempool_free(req_of_dmreq(cc, dmreq), cc->req_pool);
 
         if (!atomic_dec_and_test(&ctx->pending))
@@ -971,34 +1275,93 @@ static void crypt_encode_key(char *hex, u8 *key, unsigned int size)
         }
 }
 
+static void crypt_free_tfms(struct crypt_config *cc, int cpu)
+{
+        struct crypt_cpu *cpu_cc = per_cpu_ptr(cc->cpu, cpu);
+        unsigned i;
+
+        for (i = 0; i < cc->tfms_count; i++)
+                if (cpu_cc->tfms[i] && !IS_ERR(cpu_cc->tfms[i])) {
+                        crypto_free_ablkcipher(cpu_cc->tfms[i]);
+                        cpu_cc->tfms[i] = NULL;
+                }
+}
+
+static int crypt_alloc_tfms(struct crypt_config *cc, int cpu, char *ciphermode)
+{
+        struct crypt_cpu *cpu_cc = per_cpu_ptr(cc->cpu, cpu);
+        unsigned i;
+        int err;
+
+        for (i = 0; i < cc->tfms_count; i++) {
+                cpu_cc->tfms[i] = crypto_alloc_ablkcipher(ciphermode, 0, 0);
+                if (IS_ERR(cpu_cc->tfms[i])) {
+                        err = PTR_ERR(cpu_cc->tfms[i]);
+                        crypt_free_tfms(cc, cpu);
+                        return err;
+                }
+        }
+
+        return 0;
+}
+
+static int crypt_setkey_allcpus(struct crypt_config *cc)
+{
+        unsigned subkey_size = cc->key_size >> ilog2(cc->tfms_count);
+        int cpu, err = 0, i, r;
+
+        for_each_possible_cpu(cpu) {
+                for (i = 0; i < cc->tfms_count; i++) {
+                        r = crypto_ablkcipher_setkey(per_cpu_ptr(cc->cpu, cpu)->tfms[i],
+                                                     cc->key + (i * subkey_size), subkey_size);
+                        if (r)
+                                err = r;
+                }
+        }
+
+        return err;
+}
+
 static int crypt_set_key(struct crypt_config *cc, char *key)
 {
-        unsigned key_size = strlen(key) >> 1;
+        int r = -EINVAL;
+        int key_string_len = strlen(key);
 
-        if (cc->key_size && cc->key_size != key_size)
-                return -EINVAL;
+        /* The key size may not be changed. */
+        if (cc->key_size != (key_string_len >> 1))
+                goto out;
 
-        cc->key_size = key_size; /* initial settings */
+        /* Hyphen (which gives a key_size of zero) means there is no key. */
+        if (!cc->key_size && strcmp(key, "-"))
+                goto out;
 
-        if ((!key_size && strcmp(key, "-")) ||
-           (key_size && crypt_decode_key(cc->key, key, key_size) < 0))
-                return -EINVAL;
+        if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0)
+                goto out;
 
         set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
 
-        return crypto_ablkcipher_setkey(cc->tfm, cc->key, cc->key_size);
+        r = crypt_setkey_allcpus(cc);
+
+out:
+        /* Hex key string not needed after here, so wipe it. */
+        memset(key, '0', key_string_len);
+
+        return r;
 }
 
 static int crypt_wipe_key(struct crypt_config *cc)
 {
         clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
         memset(&cc->key, 0, cc->key_size * sizeof(u8));
-        return crypto_ablkcipher_setkey(cc->tfm, cc->key, cc->key_size);
+
+        return crypt_setkey_allcpus(cc);
 }
 
 static void crypt_dtr(struct dm_target *ti)
 {
         struct crypt_config *cc = ti->private;
+        struct crypt_cpu *cpu_cc;
+        int cpu;
 
         ti->private = NULL;
 
@@ -1010,6 +1373,14 @@ static void crypt_dtr(struct dm_target *ti)
         if (cc->crypt_queue)
                 destroy_workqueue(cc->crypt_queue);
 
+        if (cc->cpu)
+                for_each_possible_cpu(cpu) {
+                        cpu_cc = per_cpu_ptr(cc->cpu, cpu);
+                        if (cpu_cc->req)
+                                mempool_free(cpu_cc->req, cc->req_pool);
+                        crypt_free_tfms(cc, cpu);
+                }
+
         if (cc->bs)
                 bioset_free(cc->bs);
 
@@ -1023,14 +1394,14 @@ static void crypt_dtr(struct dm_target *ti)
         if (cc->iv_gen_ops && cc->iv_gen_ops->dtr)
                 cc->iv_gen_ops->dtr(cc);
 
-        if (cc->tfm && !IS_ERR(cc->tfm))
-                crypto_free_ablkcipher(cc->tfm);
-
         if (cc->dev)
                 dm_put_device(ti, cc->dev);
 
+        if (cc->cpu)
+                free_percpu(cc->cpu);
+
         kzfree(cc->cipher);
-        kzfree(cc->cipher_mode);
+        kzfree(cc->cipher_string);
 
         /* Must zero key material before freeing */
         kzfree(cc);
@@ -1040,9 +1411,9 @@ static int crypt_ctr_cipher(struct dm_target *ti,
                             char *cipher_in, char *key)
 {
         struct crypt_config *cc = ti->private;
-        char *tmp, *cipher, *chainmode, *ivmode, *ivopts;
+        char *tmp, *cipher, *chainmode, *ivmode, *ivopts, *keycount;
         char *cipher_api = NULL;
-        int ret = -EINVAL;
+        int cpu, ret = -EINVAL;
 
         /* Convert to crypto api definition? */
         if (strchr(cipher_in, '(')) {
@@ -1050,23 +1421,31 @@ static int crypt_ctr_cipher(struct dm_target *ti,
                 return -EINVAL;
         }
 
+        cc->cipher_string = kstrdup(cipher_in, GFP_KERNEL);
+        if (!cc->cipher_string)
+                goto bad_mem;
+
         /*
          * Legacy dm-crypt cipher specification
-         * cipher-mode-iv:ivopts
+         * cipher[:keycount]-mode-iv:ivopts
          */
         tmp = cipher_in;
-        cipher = strsep(&tmp, "-");
+        keycount = strsep(&tmp, "-");
+        cipher = strsep(&keycount, ":");
+
+        if (!keycount)
+                cc->tfms_count = 1;
+        else if (sscanf(keycount, "%u", &cc->tfms_count) != 1 ||
+                 !is_power_of_2(cc->tfms_count)) {
+                ti->error = "Bad cipher key count specification";
+                return -EINVAL;
+        }
+        cc->key_parts = cc->tfms_count;
 
         cc->cipher = kstrdup(cipher, GFP_KERNEL);
         if (!cc->cipher)
                 goto bad_mem;
 
-        if (tmp) {
-                cc->cipher_mode = kstrdup(tmp, GFP_KERNEL);
-                if (!cc->cipher_mode)
-                        goto bad_mem;
-        }
-
         chainmode = strsep(&tmp, "-");
         ivopts = strsep(&tmp, "-");
         ivmode = strsep(&ivopts, ":");
@@ -1074,10 +1453,19 @@ static int crypt_ctr_cipher(struct dm_target *ti,
         if (tmp)
                 DMWARN("Ignoring unexpected additional cipher options");
 
-        /* Compatibility mode for old dm-crypt mappings */
+        cc->cpu = __alloc_percpu(sizeof(*(cc->cpu)) +
+                                 cc->tfms_count * sizeof(*(cc->cpu->tfms)),
+                                 __alignof__(struct crypt_cpu));
+        if (!cc->cpu) {
+                ti->error = "Cannot allocate per cpu state";
+                goto bad_mem;
+        }
+
+        /*
+         * For compatibility with the original dm-crypt mapping format, if
+         * only the cipher name is supplied, use cbc-plain.
+         */
         if (!chainmode || (!strcmp(chainmode, "plain") && !ivmode)) {
-                kfree(cc->cipher_mode);
-                cc->cipher_mode = kstrdup("cbc-plain", GFP_KERNEL);
                 chainmode = "cbc";
                 ivmode = "plain";
         }
@@ -1099,11 +1487,12 @@ static int crypt_ctr_cipher(struct dm_target *ti,
         }
 
         /* Allocate cipher */
-        cc->tfm = crypto_alloc_ablkcipher(cipher_api, 0, 0);
-        if (IS_ERR(cc->tfm)) {
-                ret = PTR_ERR(cc->tfm);
-                ti->error = "Error allocating crypto tfm";
-                goto bad;
+        for_each_possible_cpu(cpu) {
+                ret = crypt_alloc_tfms(cc, cpu, cipher_api);
+                if (ret < 0) {
+                        ti->error = "Error allocating crypto tfm";
+                        goto bad;
+                }
         }
 
         /* Initialize and set key */
@@ -1114,7 +1503,7 @@ static int crypt_ctr_cipher(struct dm_target *ti,
         }
 
         /* Initialize IV */
-        cc->iv_size = crypto_ablkcipher_ivsize(cc->tfm);
+        cc->iv_size = crypto_ablkcipher_ivsize(any_tfm(cc));
         if (cc->iv_size)
                 /* at least a 64 bit sector number should fit in our buffer */
                 cc->iv_size = max(cc->iv_size,
@@ -1137,7 +1526,15 @@ static int crypt_ctr_cipher(struct dm_target *ti,
                 cc->iv_gen_ops = &crypt_iv_benbi_ops;
         else if (strcmp(ivmode, "null") == 0)
                 cc->iv_gen_ops = &crypt_iv_null_ops;
-        else {
+        else if (strcmp(ivmode, "lmk") == 0) {
+                cc->iv_gen_ops = &crypt_iv_lmk_ops;
+                /* Version 2 and 3 is recognised according
+                 * to length of provided multi-key string.
+                 * If present (version 3), last key is used as IV seed.
+                 */
+                if (cc->key_size % cc->key_parts)
+                        cc->key_parts++;
+        } else {
                 ret = -EINVAL;
                 ti->error = "Invalid IV mode";
                 goto bad;
@@ -1194,6 +1591,7 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
                 ti->error = "Cannot allocate encryption context";
                 return -ENOMEM;
         }
+        cc->key_size = key_size;
 
         ti->private = cc;
         ret = crypt_ctr_cipher(ti, argv[0], argv[1]);
@@ -1208,9 +1606,9 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         }
 
         cc->dmreq_start = sizeof(struct ablkcipher_request);
-        cc->dmreq_start += crypto_ablkcipher_reqsize(cc->tfm);
+        cc->dmreq_start += crypto_ablkcipher_reqsize(any_tfm(cc));
         cc->dmreq_start = ALIGN(cc->dmreq_start, crypto_tfm_ctx_alignment());
-        cc->dmreq_start += crypto_ablkcipher_alignmask(cc->tfm) &
+        cc->dmreq_start += crypto_ablkcipher_alignmask(any_tfm(cc)) &
                            ~(crypto_tfm_ctx_alignment() - 1);
 
         cc->req_pool = mempool_create_kmalloc_pool(MIN_IOS, cc->dmreq_start +
@@ -1219,7 +1617,6 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
                 ti->error = "Cannot allocate crypt request mempool";
                 goto bad;
         }
-        cc->req = NULL;
 
         cc->page_pool = mempool_create_page_pool(MIN_POOL_PAGES, 0);
         if (!cc->page_pool) {
@@ -1252,13 +1649,20 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         cc->start = tmpll;
 
         ret = -ENOMEM;
-        cc->io_queue = create_singlethread_workqueue("kcryptd_io");
+        cc->io_queue = alloc_workqueue("kcryptd_io",
+                                       WQ_NON_REENTRANT|
+                                       WQ_MEM_RECLAIM,
+                                       1);
         if (!cc->io_queue) {
                 ti->error = "Couldn't create kcryptd io queue";
                 goto bad;
         }
 
-        cc->crypt_queue = create_singlethread_workqueue("kcryptd");
+        cc->crypt_queue = alloc_workqueue("kcryptd",
+                                          WQ_NON_REENTRANT|
+                                          WQ_CPU_INTENSIVE|
+                                          WQ_MEM_RECLAIM,
+                                          1);
         if (!cc->crypt_queue) {
                 ti->error = "Couldn't create kcryptd queue";
                 goto bad;
@@ -1278,7 +1682,7 @@ static int crypt_map(struct dm_target *ti, struct bio *bio,
         struct dm_crypt_io *io;
         struct crypt_config *cc;
 
-        if (unlikely(bio_empty_barrier(bio))) {
+        if (bio->bi_rw & REQ_FLUSH) {
                 cc = ti->private;
                 bio->bi_bdev = cc->dev->bdev;
                 return DM_MAPIO_REMAPPED;
@@ -1286,9 +1690,10 @@ static int crypt_map(struct dm_target *ti, struct bio *bio,
 
         io = crypt_io_alloc(ti, bio, dm_target_offset(ti, bio->bi_sector));
 
-        if (bio_data_dir(io->base_bio) == READ)
-                kcryptd_queue_io(io);
-        else
+        if (bio_data_dir(io->base_bio) == READ) {
+                if (kcryptd_io_read(io, GFP_NOWAIT))
+                        kcryptd_queue_io(io);
+        } else
                 kcryptd_queue_crypt(io);
 
         return DM_MAPIO_SUBMITTED;
@@ -1306,10 +1711,7 @@ static int crypt_status(struct dm_target *ti, status_type_t type,
                 break;
 
         case STATUSTYPE_TABLE:
-                if (cc->cipher_mode)
-                        DMEMIT("%s-%s ", cc->cipher, cc->cipher_mode);
-                else
-                        DMEMIT("%s ", cc->cipher);
+                DMEMIT("%s ", cc->cipher_string);
 
                 if (cc->key_size > 0) {
                         if ((maxlen - sz) < ((cc->key_size << 1) + 1))
@@ -1421,7 +1823,7 @@ static int crypt_iterate_devices(struct dm_target *ti,
 
 static struct target_type crypt_target = {
         .name   = "crypt",
-        .version = {1, 7, 0},
+        .version = {1, 10, 0},
         .module = THIS_MODULE,
         .ctr    = crypt_ctr,
         .dtr    = crypt_dtr,