Index: linux-2.6.36-rc7-ak/drivers/md/dm-crypt.c
===================================================================
--- linux-2.6.36-rc7-ak.orig/drivers/md/dm-crypt.c
+++ linux-2.6.36-rc7-ak/drivers/md/dm-crypt.c
@@ -18,6 +18,7 @@
 #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>
@@ -77,11 +78,15 @@ struct crypt_iv_operations {
 };
 
 struct iv_essiv_private {
-	struct crypto_cipher *tfm;
 	struct crypto_hash *hash_tfm;
 	u8 *salt;
 };
 
+/* Duplicated per CPU state for cipher */
+struct iv_essiv_private_cpu {
+	struct crypto_cipher *tfm;
+};
+
 struct iv_benbi_private {
 	int shift;
 };
@@ -91,6 +96,18 @@ struct iv_benbi_private {
  * 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;
+	struct crypto_ablkcipher *tfm;
+	struct iv_essiv_private_cpu ie;
+};
+
+/*
+ * 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;
@@ -104,9 +121,6 @@ struct crypt_config {
 	mempool_t *page_pool;
 	struct bio_set *bs;
 
-	struct workqueue_struct *io_queue;
-	struct workqueue_struct *crypt_queue;
-
 	char *cipher;
 	char *cipher_mode;
 
@@ -119,6 +133,12 @@ struct crypt_config {
 	unsigned int iv_size;
 
 	/*
+	 * Duplicated per cpu state. Access through
+	 * per_cpu_ptr() only.
+	 */
+	struct crypt_cpu __percpu *cpu;
+
+	/*
 	 * Layout of each crypto request:
 	 *
 	 *   struct ablkcipher_request
@@ -132,23 +152,42 @@ struct crypt_config {
 	 * correctly aligned.
 	 */
 	unsigned int dmreq_start;
-	struct ablkcipher_request *req;
 
-	struct crypto_ablkcipher *tfm;
 	unsigned long flags;
 	unsigned int key_size;
 	u8 key[0];
 };
 
+/* RED-PEN scale with number of cpus? */
 #define MIN_IOS        16
 #define MIN_POOL_PAGES 32
 #define MIN_BIO_PAGES  8
 
+/* Protect creation of a new crypt queue */
+static DEFINE_MUTEX(queue_setup_lock);
+static struct workqueue_struct *crypt_workqueue;
+static struct workqueue_struct *io_workqueue;
+static DEFINE_PER_CPU(struct task_struct *, io_wq_cpu);
+
 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 struct crypt_cpu *crypt_me(struct crypt_config *cc)
+{
+	return this_cpu_ptr(cc->cpu);
+}
+
+/* Use this for cipher attributes that are the same for all cpus */
+static struct crypto_ablkcipher *any_tfm(struct crypt_config *cc)
+{
+	struct crypto_ablkcipher *tfm;
+	/* cpu doesn't matter, output is always the same */
+	tfm = __this_cpu_ptr(cc->cpu)->tfm;
+	return tfm;
+}
+
 /*
  * Different IV generation algorithms:
  *
@@ -195,7 +234,7 @@ static int crypt_iv_essiv_init(struct cr
 	struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
 	struct hash_desc desc;
 	struct scatterlist sg;
-	int err;
+	int err, n, cpu;
 
 	sg_init_one(&sg, cc->key, cc->key_size);
 	desc.tfm = essiv->hash_tfm;
@@ -205,8 +244,18 @@ static int crypt_iv_essiv_init(struct cr
 	if (err)
 		return err;
 
-	return crypto_cipher_setkey(essiv->tfm, essiv->salt,
+	for_each_possible_cpu (cpu) {
+		struct crypt_cpu *cs = per_cpu_ptr(cc->cpu, cpu);
+
+		n = crypto_cipher_setkey(cs->ie.tfm, essiv->salt,
 				    crypto_hash_digestsize(essiv->hash_tfm));
+		if (n) {
+			err = n;
+			break;
+		}
+	}
+
+	return err;
 }
 
 /* Wipe salt and reset key derived from volume key */
@@ -214,24 +263,70 @@ static int crypt_iv_essiv_wipe(struct cr
 {
 	struct iv_essiv_private *essiv = &cc->iv_gen_private.essiv;
 	unsigned salt_size = crypto_hash_digestsize(essiv->hash_tfm);
+	int cpu, err, n;
 
 	memset(essiv->salt, 0, salt_size);
 
-	return crypto_cipher_setkey(essiv->tfm, essiv->salt, salt_size);
+	err = 0;
+	for_each_possible_cpu (cpu) {
+		struct crypt_cpu *cs = per_cpu_ptr(cc->cpu, cpu);
+		n = crypto_cipher_setkey(cs->ie.tfm, essiv->salt, salt_size);
+		if (n)
+			err = n;
+	}
+	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 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) {
+		struct crypt_cpu *cs = per_cpu_ptr(cc->cpu, cpu);
+		if (cs->ie.tfm) {
+			crypto_free_cipher(cs->ie.tfm);
+			cs->ie.tfm = NULL;
+		}
+	}
 }
 
 static int crypt_iv_essiv_ctr(struct crypt_config *cc, struct dm_target *ti,
@@ -241,6 +336,7 @@ static int crypt_iv_essiv_ctr(struct cry
 	struct crypto_hash *hash_tfm = NULL;
 	u8 *salt = NULL;
 	int err;
+	int cpu;
 
 	if (!opts) {
 		ti->error = "Digest algorithm missing for ESSIV mode";
@@ -262,30 +358,22 @@ static int crypt_iv_essiv_ctr(struct cry
 		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)) {
+			kfree(salt);
+			crypt_iv_essiv_dtr(cc);
+			return PTR_ERR(essiv_tfm);
+		}
+		per_cpu_ptr(cc->cpu, cpu)->ie.tfm = 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);
@@ -296,14 +384,14 @@ static int crypt_iv_essiv_gen(struct cry
 {
 	memset(iv, 0, cc->iv_size);
 	*(u64 *)iv = cpu_to_le64(sector);
-	crypto_cipher_encrypt_one(cc->iv_gen_private.essiv.tfm, iv, iv);
+	crypto_cipher_encrypt_one(crypt_me(cc)->ie.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
@@ -412,7 +500,7 @@ static int crypt_convert_block(struct cr
 
 	dmreq = dmreq_of_req(cc, req);
 	iv = (u8 *)ALIGN((unsigned long)(dmreq + 1),
-			 crypto_ablkcipher_alignmask(cc->tfm) + 1);
+			 crypto_ablkcipher_alignmask(any_tfm(cc)) + 1);
 
 	dmreq->ctx = ctx;
 	sg_init_table(&dmreq->sg_in, 1);
@@ -457,13 +545,14 @@ static void kcryptd_async_done(struct cr
 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 |
+	struct crypt_cpu *cs = crypt_me(cc);
+	if (!cs->req)
+		cs->req = mempool_alloc(cc->req_pool, GFP_NOIO);
+	ablkcipher_request_set_tfm(cs->req, cs->tfm);
+	ablkcipher_request_set_callback(cs->req, CRYPTO_TFM_REQ_MAY_BACKLOG |
 					CRYPTO_TFM_REQ_MAY_SLEEP,
 					kcryptd_async_done,
-					dmreq_of_req(cc, cc->req));
+					dmreq_of_req(cc, cs->req));
 }
 
 /*
@@ -472,6 +561,7 @@ static void crypt_alloc_req(struct crypt
 static int crypt_convert(struct crypt_config *cc,
 			 struct convert_context *ctx)
 {
+	struct crypt_cpu *cs = crypt_me(cc);
 	int r;
 
 	atomic_set(&ctx->pending, 1);
@@ -483,7 +573,7 @@ static int crypt_convert(struct crypt_co
 
 		atomic_inc(&ctx->pending);
 
-		r = crypt_convert_block(cc, ctx, cc->req);
+		r = crypt_convert_block(cc, ctx, cs->req);
 
 		switch (r) {
 		/* async */
@@ -492,7 +582,7 @@ static int crypt_convert(struct crypt_co
 			INIT_COMPLETION(ctx->restart);
 			/* fall through*/
 		case -EINPROGRESS:
-			cc->req = NULL;
+			cs->req = NULL;
 			ctx->sector++;
 			continue;
 
@@ -651,6 +741,9 @@ static void crypt_dec_pending(struct dm_
  * 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 dmcrypt instances.
+ * They should not depend on each other and do not block.
  */
 static void crypt_endio(struct bio *clone, int error)
 {
@@ -732,6 +825,7 @@ static void kcryptd_io(struct work_struc
 {
 	struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
 
+	__this_cpu_write(io_wq_cpu, current);
 	if (bio_data_dir(io->base_bio) == READ)
 		kcryptd_io_read(io);
 	else
@@ -740,10 +834,23 @@ static void kcryptd_io(struct work_struc
 
 static void kcryptd_queue_io(struct dm_crypt_io *io)
 {
-	struct crypt_config *cc = io->target->private;
+	int cpu;
+
+	/*
+	 * Since we only have a single worker per CPU in extreme
+	 * cases there might be nesting (dm-crypt on another dm-crypt)
+	 * To avoid deadlock run the work directly then.
+	 */
+	cpu = get_cpu();
+	if (per_cpu(io_wq_cpu, cpu) == current && !in_interrupt()) {
+		put_cpu();
+		kcryptd_io(&io->work);
+		return;
+	}
 
 	INIT_WORK(&io->work, kcryptd_io);
-	queue_work(cc->io_queue, &io->work);
+	queue_work(io_workqueue, &io->work);
+	put_cpu();
 }
 
 static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io,
@@ -924,10 +1031,8 @@ static void kcryptd_crypt(struct work_st
 
 static void kcryptd_queue_crypt(struct dm_crypt_io *io)
 {
-	struct crypt_config *cc = io->target->private;
-
 	INIT_WORK(&io->work, kcryptd_crypt);
-	queue_work(cc->crypt_queue, &io->work);
+	queue_work(crypt_workqueue, &io->work);
 }
 
 /*
@@ -971,6 +1076,21 @@ static void crypt_encode_key(char *hex,
 	}
 }
 
+static int crypt_setkey_allcpus(struct crypt_config *cc)
+{
+	int cpu, n, err;
+
+	err = 0;
+	for_each_possible_cpu (cpu) {
+		struct crypt_cpu *cs = per_cpu_ptr(cc->cpu, cpu);
+		n = crypto_ablkcipher_setkey(cs->tfm, cc->key, cc->key_size);
+		if (n)
+			err = n;
+	}
+	return err;
+}
+
+
 static int crypt_set_key(struct crypt_config *cc, char *key)
 {
 	unsigned key_size = strlen(key) >> 1;
@@ -986,29 +1106,68 @@ static int crypt_set_key(struct crypt_co
 
 	set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
 
-	return crypto_ablkcipher_setkey(cc->tfm, cc->key, cc->key_size);
+	return crypt_setkey_allcpus(cc);
 }
 
 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);
+}
+
+/* Use a global per-CPU encryption workqueue for all mounts */
+static int crypt_create_workqueues(void)
+{
+	int ret = 0;
+
+	/* Module unload cleans up on error */
+	mutex_lock(&queue_setup_lock);
+	if (!crypt_workqueue) {
+		crypt_workqueue = alloc_workqueue("dmcrypt",
+						  WQ_CPU_INTENSIVE|WQ_RESCUER,
+						  1);
+		if (!crypt_workqueue)
+			ret = -ENOMEM;
+	}
+	if (!io_workqueue) {
+		io_workqueue = create_workqueue("dmcrypt-io");
+		if (!io_workqueue)
+			ret = -ENOMEM;
+	}
+	mutex_unlock(&queue_setup_lock);
+	return ret;
+}
+
+static void crypt_dtr_cpus(struct crypt_config *cc)
+{
+	int cpu;
+
+	for_each_possible_cpu (cpu) {
+		struct crypt_cpu *cs = per_cpu_ptr(cc->cpu, cpu);
+		if (cs->tfm) {
+			crypto_free_ablkcipher(cs->tfm);
+			cs->tfm = NULL;
+		}
+	}
 }
 
 static void crypt_dtr(struct dm_target *ti)
 {
 	struct crypt_config *cc = ti->private;
+	int cpu;
 
 	ti->private = NULL;
 
 	if (!cc)
 		return;
 
-	if (cc->io_queue)
-		destroy_workqueue(cc->io_queue);
-	if (cc->crypt_queue)
-		destroy_workqueue(cc->crypt_queue);
+	for_each_possible_cpu (cpu) {
+		struct crypt_cpu *cs = per_cpu_ptr(cc->cpu, cpu);
+		if (cs->req)
+			mempool_free(cs->req, cc->req_pool);
+	}
+
 
 	if (cc->bs)
 		bioset_free(cc->bs);
@@ -1023,12 +1182,14 @@ static void crypt_dtr(struct dm_target *
 	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);
 
+	crypt_dtr_cpus(cc);
+
+	if (cc->cpu)
+		free_percpu(cc->cpu);
+
 	kzfree(cc->cipher);
 	kzfree(cc->cipher_mode);
 
@@ -1040,9 +1201,11 @@ static int crypt_ctr_cipher(struct dm_ta
 			    char *cipher_in, char *key)
 {
 	struct crypt_config *cc = ti->private;
+	struct crypto_ablkcipher *tfm;
 	char *tmp, *cipher, *chainmode, *ivmode, *ivopts;
 	char *cipher_api = NULL;
 	int ret = -EINVAL;
+	int cpu;
 
 	/* Convert to crypto api definition? */
 	if (strchr(cipher_in, '(')) {
@@ -1074,6 +1237,12 @@ static int crypt_ctr_cipher(struct dm_ta
 	if (tmp)
 		DMWARN("Ignoring unexpected additional cipher options");
 
+	cc->cpu = alloc_percpu(struct crypt_cpu);
+	if (!cc->cpu) {
+		ti->error = "Cannot allocate per cpu state";
+		goto bad_mem;
+	}
+
 	/* Compatibility mode for old dm-crypt mappings */
 	if (!chainmode || (!strcmp(chainmode, "plain") && !ivmode)) {
 		kfree(cc->cipher_mode);
@@ -1099,12 +1268,16 @@ static int crypt_ctr_cipher(struct dm_ta
 	}
 
 	/* 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) {
+		tfm = crypto_alloc_ablkcipher(cipher_api, 0, 0);
+		if (IS_ERR(tfm)) {
+			ret = PTR_ERR(tfm);
+			ti->error = "Error allocating crypto tfm";
+			goto bad;
+		}
+		per_cpu_ptr(cc->cpu, cpu)->tfm = tfm;
+ 	}
+	tfm = any_tfm(cc);
 
 	/* Initialize and set key */
 	ret = crypt_set_key(cc, key);
@@ -1114,7 +1287,7 @@ static int crypt_ctr_cipher(struct dm_ta
 	}
 
 	/* Initialize IV */
-	cc->iv_size = crypto_ablkcipher_ivsize(cc->tfm);
+	cc->iv_size = crypto_ablkcipher_ivsize(tfm);
 	if (cc->iv_size)
 		/* at least a 64 bit sector number should fit in our buffer */
 		cc->iv_size = max(cc->iv_size,
@@ -1181,6 +1354,7 @@ static int crypt_ctr(struct dm_target *t
 	unsigned int key_size;
 	unsigned long long tmpll;
 	int ret;
+	int cpu;
 
 	if (argc != 5) {
 		ti->error = "Not enough arguments";
@@ -1208,9 +1382,9 @@ static int crypt_ctr(struct dm_target *t
 	}
 
 	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 +1393,6 @@ static int crypt_ctr(struct dm_target *t
 		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) {
@@ -1233,6 +1406,14 @@ static int crypt_ctr(struct dm_target *t
 		goto bad;
 	}
 
+	for_each_possible_cpu (cpu) {
+		struct crypt_cpu *cs = per_cpu_ptr(cc->cpu, cpu);
+		if (crypto_ablkcipher_setkey(cs->tfm, cc->key, key_size) < 0) {
+			ti->error = "Error setting key";
+			goto bad;
+		}
+	}
+
 	ret = -EINVAL;
 	if (sscanf(argv[2], "%llu", &tmpll) != 1) {
 		ti->error = "Invalid iv_offset sector";
@@ -1251,16 +1432,8 @@ static int crypt_ctr(struct dm_target *t
 	}
 	cc->start = tmpll;
 
-	ret = -ENOMEM;
-	cc->io_queue = create_singlethread_workqueue("kcryptd_io");
-	if (!cc->io_queue) {
-		ti->error = "Couldn't create kcryptd io queue";
-		goto bad;
-	}
-
-	cc->crypt_queue = create_singlethread_workqueue("kcryptd");
-	if (!cc->crypt_queue) {
-		ti->error = "Couldn't create kcryptd queue";
+	if (crypt_create_workqueues() < 0) {
+		ti->error = "Couldn't create kcrypt work queues";
 		goto bad;
 	}
 
@@ -1456,6 +1629,10 @@ static void __exit dm_crypt_exit(void)
 {
 	dm_unregister_target(&crypt_target);
 	kmem_cache_destroy(_crypt_io_pool);
+	if (crypt_workqueue)
+		destroy_workqueue(crypt_workqueue);
+	if (io_workqueue)
+		destroy_workqueue(io_workqueue);
 }
 
 module_init(dm_crypt_init);
