diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index 02a5345..8f85df6 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -500,4 +500,20 @@
 
 	  If unsure, say N.
 
+config DM_ANDROID_VERITY
+	bool "Android verity target support"
+	depends on DM_VERITY
+	depends on X509_CERTIFICATE_PARSER
+	depends on SYSTEM_TRUSTED_KEYRING
+	depends on PUBLIC_KEY_ALGO_RSA
+	depends on KEYS
+	depends on ASYMMETRIC_KEY_TYPE
+	depends on ASYMMETRIC_PUBLIC_KEY_SUBTYPE
+	---help---
+	  This device-mapper target is virtually a VERITY target. This
+	  target is setup by reading the metadata contents piggybacked
+	  to the actual data blocks in the block device. The signature
+	  of the metadata contents are verified against the key included
+	  in the system keyring. Upon success, the underlying verity
+	  target is setup.
 endif # MD
diff --git a/drivers/md/Makefile b/drivers/md/Makefile
index 3cbda1a..fa5941fc 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -67,3 +67,7 @@
 ifeq ($(CONFIG_DM_VERITY_FEC),y)
 dm-verity-objs			+= dm-verity-fec.o
 endif
+
+ifeq ($(CONFIG_DM_ANDROID_VERITY),y)
+dm-verity-objs			+= dm-android-verity.o
+endif
diff --git a/drivers/md/dm-android-verity.c b/drivers/md/dm-android-verity.c
new file mode 100644
index 0000000..c77c9fa
--- /dev/null
+++ b/drivers/md/dm-android-verity.c
@@ -0,0 +1,771 @@
+/*
+ * Copyright (C) 2015 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/buffer_head.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/device-mapper.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/fcntl.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/key.h>
+#include <linux/module.h>
+#include <linux/mount.h>
+#include <linux/namei.h>
+#include <linux/of.h>
+#include <linux/reboot.h>
+#include <linux/string.h>
+#include <linux/vmalloc.h>
+
+#include <asm/setup.h>
+#include <crypto/hash.h>
+#include <crypto/public_key.h>
+#include <crypto/sha.h>
+#include <keys/asymmetric-type.h>
+#include <keys/system_keyring.h>
+
+#include "dm-verity.h"
+#include "dm-android-verity.h"
+
+static char verifiedbootstate[VERITY_COMMANDLINE_PARAM_LENGTH];
+static char veritymode[VERITY_COMMANDLINE_PARAM_LENGTH];
+
+static int __init verified_boot_state_param(char *line)
+{
+	strlcpy(verifiedbootstate, line, sizeof(verifiedbootstate));
+	return 1;
+}
+
+__setup("androidboot.verifiedbootstate=", verified_boot_state_param);
+
+static int __init verity_mode_param(char *line)
+{
+	strlcpy(veritymode, line, sizeof(veritymode));
+	return 1;
+}
+
+__setup("androidboot.veritymode=", verity_mode_param);
+
+static int table_extract_mpi_array(struct public_key_signature *pks,
+				const void *data, size_t len)
+{
+	MPI mpi = mpi_read_raw_data(data, len);
+
+	if (!mpi) {
+		DMERR("Error while allocating mpi array");
+		return -ENOMEM;
+	}
+
+	pks->mpi[0] = mpi;
+	pks->nr_mpi = 1;
+	return 0;
+}
+
+static struct public_key_signature *table_make_digest(
+						enum pkey_hash_algo hash,
+						const void *table,
+						unsigned long table_len)
+{
+	struct public_key_signature *pks = NULL;
+	struct crypto_shash *tfm;
+	struct shash_desc *desc;
+	size_t digest_size, desc_size;
+	int ret;
+
+	/* Allocate the hashing algorithm we're going to need and find out how
+	 * big the hash operational data will be.
+	 */
+	tfm = crypto_alloc_shash(pkey_hash_algo[hash], 0, 0);
+	if (IS_ERR(tfm))
+		return ERR_CAST(tfm);
+
+	desc_size = crypto_shash_descsize(tfm) + sizeof(*desc);
+	digest_size = crypto_shash_digestsize(tfm);
+
+	/* We allocate the hash operational data storage on the end of out
+	 * context data and the digest output buffer on the end of that.
+	 */
+	ret = -ENOMEM;
+	pks = kzalloc(digest_size + sizeof(*pks) + desc_size, GFP_KERNEL);
+	if (!pks)
+		goto error;
+
+	pks->pkey_hash_algo = hash;
+	pks->digest = (u8 *)pks + sizeof(*pks) + desc_size;
+	pks->digest_size = digest_size;
+
+	desc = (struct shash_desc *)(pks + 1);
+	desc->tfm = tfm;
+	desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP;
+
+	ret = crypto_shash_init(desc);
+	if (ret < 0)
+		goto error;
+
+	ret = crypto_shash_finup(desc, table, table_len, pks->digest);
+	if (ret < 0)
+		goto error;
+
+	crypto_free_shash(tfm);
+	return pks;
+
+error:
+	kfree(pks);
+	crypto_free_shash(tfm);
+	return ERR_PTR(ret);
+}
+
+static int read_block_dev(struct bio_read *payload, struct block_device *bdev,
+		sector_t offset, int length)
+{
+	struct bio *bio;
+	int err = 0, i;
+
+	payload->number_of_pages = DIV_ROUND_UP(length, PAGE_SIZE);
+
+	bio = bio_alloc(GFP_KERNEL, payload->number_of_pages);
+	if (!bio) {
+		DMERR("Error while allocating bio");
+		return -ENOMEM;
+	}
+
+	bio->bi_bdev = bdev;
+	bio->bi_sector = offset;
+
+	payload->page_io = kzalloc(sizeof(struct page *) *
+		payload->number_of_pages, GFP_KERNEL);
+	if (!payload->page_io) {
+		DMERR("page_io array alloc failed");
+		err = -ENOMEM;
+		goto free_bio;
+	}
+
+	for (i = 0; i < payload->number_of_pages; i++) {
+		payload->page_io[i] = alloc_page(GFP_KERNEL);
+		if (!payload->page_io[i]) {
+			DMERR("alloc_page failed");
+			err = -ENOMEM;
+			goto free_pages;
+		}
+		if (!bio_add_page(bio, payload->page_io[i], PAGE_SIZE, 0)) {
+			DMERR("bio_add_page error");
+			err = -EIO;
+			goto free_pages;
+		}
+	}
+
+	if (!submit_bio_wait(READ, bio))
+		/* success */
+		goto free_bio;
+	DMERR("bio read failed");
+	err = -EIO;
+
+free_pages:
+	for (i = 0; i < payload->number_of_pages; i++)
+		if (payload->page_io[i])
+			__free_page(payload->page_io[i]);
+	kfree(payload->page_io);
+free_bio:
+	bio_put(bio);
+	return err;
+}
+
+static inline u64 fec_div_round_up(u64 x, u64 y)
+{
+	u64 remainder;
+
+	return div64_u64_rem(x, y, &remainder) +
+		(remainder > 0 ? 1 : 0);
+}
+
+static inline void populate_fec_metadata(struct fec_header *header,
+				struct fec_ecc_metadata *ecc)
+{
+	ecc->blocks = fec_div_round_up(le64_to_cpu(header->inp_size),
+			FEC_BLOCK_SIZE);
+	ecc->roots = le32_to_cpu(header->roots);
+	ecc->start = le64_to_cpu(header->inp_size);
+}
+
+static inline int validate_fec_header(struct fec_header *header, u64 offset)
+{
+	/* move offset to make the sanity check work for backup header
+	 * as well. */
+	offset -= offset % FEC_BLOCK_SIZE;
+	if (le32_to_cpu(header->magic) != FEC_MAGIC ||
+		le32_to_cpu(header->version) != FEC_VERSION ||
+		le32_to_cpu(header->size) != sizeof(struct fec_header) ||
+		le32_to_cpu(header->roots) == 0 ||
+		le32_to_cpu(header->roots) >= FEC_RSM ||
+		offset < le32_to_cpu(header->fec_size) ||
+		offset - le32_to_cpu(header->fec_size) !=
+		le64_to_cpu(header->inp_size))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int extract_fec_header(dev_t dev, struct fec_header *fec,
+				struct fec_ecc_metadata *ecc)
+{
+	u64 device_size;
+	struct bio_read payload;
+	int i, err = 0;
+	struct block_device *bdev;
+
+	bdev = blkdev_get_by_dev(dev, FMODE_READ, NULL);
+
+	if (IS_ERR(bdev)) {
+		DMERR("bdev get error");
+		return PTR_ERR(bdev);
+	}
+
+	device_size = i_size_read(bdev->bd_inode);
+
+	/* fec metadata size is a power of 2 and PAGE_SIZE
+	 * is a power of 2 as well.
+	 */
+	BUG_ON(FEC_BLOCK_SIZE > PAGE_SIZE);
+	/* 512 byte sector alignment */
+	BUG_ON(((device_size - FEC_BLOCK_SIZE) % (1 << SECTOR_SHIFT)) != 0);
+
+	err = read_block_dev(&payload, bdev, (device_size -
+		FEC_BLOCK_SIZE) / (1 << SECTOR_SHIFT), FEC_BLOCK_SIZE);
+	if (err) {
+		DMERR("Error while reading verity metadata");
+		goto error;
+	}
+
+	BUG_ON(sizeof(struct fec_header) > PAGE_SIZE);
+	memcpy(fec, page_address(payload.page_io[0]),
+			sizeof(*fec));
+
+	ecc->valid = true;
+	if (validate_fec_header(fec, device_size - FEC_BLOCK_SIZE)) {
+		/* Try the backup header */
+		memcpy(fec, page_address(payload.page_io[0]) + FEC_BLOCK_SIZE
+			- sizeof(*fec) ,
+			sizeof(*fec));
+		if (validate_fec_header(fec, device_size -
+			sizeof(struct fec_header)))
+			ecc->valid = false;
+	}
+
+	if (ecc->valid)
+		populate_fec_metadata(fec, ecc);
+
+	for (i = 0; i < payload.number_of_pages; i++)
+		__free_page(payload.page_io[i]);
+	kfree(payload.page_io);
+
+error:
+	blkdev_put(bdev, FMODE_READ);
+	return err;
+}
+static void find_metadata_offset(struct fec_header *fec,
+		struct block_device *bdev, u64 *metadata_offset)
+{
+	u64 device_size;
+
+	device_size = i_size_read(bdev->bd_inode);
+
+	if (le32_to_cpu(fec->magic) == FEC_MAGIC)
+		*metadata_offset = le64_to_cpu(fec->inp_size) -
+					VERITY_METADATA_SIZE;
+	else
+		*metadata_offset = device_size - VERITY_METADATA_SIZE;
+}
+
+static struct android_metadata *extract_metadata(dev_t dev,
+				struct fec_header *fec)
+{
+	struct block_device *bdev;
+	struct android_metadata_header *header;
+	struct android_metadata *uninitialized_var(metadata);
+	int i;
+	u32 table_length, copy_length, offset;
+	u64 metadata_offset;
+	struct bio_read payload;
+	int err = 0;
+
+	bdev = blkdev_get_by_dev(dev, FMODE_READ, NULL);
+
+	if (IS_ERR(bdev)) {
+		DMERR("blkdev_get_by_dev failed");
+		return ERR_CAST(bdev);
+	}
+
+	find_metadata_offset(fec, bdev, &metadata_offset);
+
+	/* Verity metadata size is a power of 2 and PAGE_SIZE
+	 * is a power of 2 as well.
+	 * PAGE_SIZE is also a multiple of 512 bytes.
+	*/
+	if (VERITY_METADATA_SIZE > PAGE_SIZE)
+		BUG_ON(VERITY_METADATA_SIZE % PAGE_SIZE != 0);
+	/* 512 byte sector alignment */
+	BUG_ON(metadata_offset % (1 << SECTOR_SHIFT) != 0);
+
+	err = read_block_dev(&payload, bdev, metadata_offset /
+		(1 << SECTOR_SHIFT), VERITY_METADATA_SIZE);
+	if (err) {
+		DMERR("Error while reading verity metadata");
+		metadata = ERR_PTR(err);
+		goto blkdev_release;
+	}
+
+	header = kzalloc(sizeof(*header), GFP_KERNEL);
+	if (!header) {
+		DMERR("kzalloc failed for header");
+		err = -ENOMEM;
+		goto free_payload;
+	}
+
+	memcpy(header, page_address(payload.page_io[0]),
+		sizeof(*header));
+
+	DMINFO("bio magic_number:%u protocol_version:%d table_length:%u",
+		le32_to_cpu(header->magic_number),
+		le32_to_cpu(header->protocol_version),
+		le32_to_cpu(header->table_length));
+
+	metadata = kzalloc(sizeof(*metadata), GFP_KERNEL);
+	if (!metadata) {
+		DMERR("kzalloc for metadata failed");
+		err = -ENOMEM;
+		goto free_header;
+	}
+
+	metadata->header = header;
+	table_length = le32_to_cpu(header->table_length);
+
+	if (table_length == 0 ||
+		table_length > (VERITY_METADATA_SIZE -
+			sizeof(struct android_metadata_header)))
+		goto free_metadata;
+
+	metadata->verity_table = kzalloc(table_length + 1, GFP_KERNEL);
+
+	if (!metadata->verity_table) {
+		DMERR("kzalloc verity_table failed");
+		err = -ENOMEM;
+		goto free_metadata;
+	}
+
+	if (sizeof(struct android_metadata_header) +
+			table_length <= PAGE_SIZE) {
+		memcpy(metadata->verity_table, page_address(payload.page_io[0])
+			+ sizeof(struct android_metadata_header),
+			table_length);
+	} else {
+		copy_length = PAGE_SIZE -
+			sizeof(struct android_metadata_header);
+		memcpy(metadata->verity_table, page_address(payload.page_io[0])
+			+ sizeof(struct android_metadata_header),
+			copy_length);
+		table_length -= copy_length;
+		offset = copy_length;
+		i = 1;
+		while (table_length != 0) {
+			if (table_length > PAGE_SIZE) {
+				memcpy(metadata->verity_table + offset,
+					page_address(payload.page_io[i]),
+					PAGE_SIZE);
+				offset += PAGE_SIZE;
+				table_length -= PAGE_SIZE;
+			} else {
+				memcpy(metadata->verity_table + offset,
+					page_address(payload.page_io[i]),
+					table_length);
+				table_length = 0;
+			}
+			i++;
+		}
+	}
+	metadata->verity_table[table_length] = '\0';
+
+	goto free_payload;
+
+free_metadata:
+	kfree(metadata);
+free_header:
+	kfree(header);
+	metadata = ERR_PTR(err);
+free_payload:
+	for (i = 0; i < payload.number_of_pages; i++)
+		if (payload.page_io[i])
+			__free_page(payload.page_io[i]);
+	kfree(payload.page_io);
+
+	DMINFO("verity_table: %s", metadata->verity_table);
+blkdev_release:
+	blkdev_put(bdev, FMODE_READ);
+	return metadata;
+}
+
+/* helper functions to extract properties from dts */
+const char *find_dt_value(const char *name)
+{
+	struct device_node *firmware;
+	const char *value;
+
+	firmware = of_find_node_by_path("/firmware/android");
+	if (!firmware)
+		return NULL;
+	value = of_get_property(firmware, name, NULL);
+	of_node_put(firmware);
+
+	return value;
+}
+
+static bool is_unlocked(void)
+{
+	static const char unlocked[]  = "orange";
+	static const char verified_boot_prop[] = "verifiedbootstate";
+	const char *value;
+
+	value = find_dt_value(verified_boot_prop);
+	if (!value)
+		value = verifiedbootstate;
+
+	return !strncmp(value, unlocked, sizeof(unlocked) - 1);
+}
+
+static int verity_mode(void)
+{
+	static const char enforcing[] = "enforcing";
+	static const char verified_mode_prop[] = "veritymode";
+	const char *value;
+
+	value = find_dt_value(verified_mode_prop);
+	if (!value)
+		value = veritymode;
+	if (!strncmp(value, enforcing, sizeof(enforcing) - 1))
+		return DM_VERITY_MODE_RESTART;
+
+	return DM_VERITY_MODE_EIO;
+}
+
+static int verify_header(struct android_metadata_header *header)
+{
+	int retval = -EINVAL;
+
+	if (is_unlocked() && le32_to_cpu(header->magic_number) ==
+		VERITY_METADATA_MAGIC_DISABLE) {
+		retval = VERITY_STATE_DISABLE;
+		return retval;
+	}
+
+	if (!(le32_to_cpu(header->magic_number) ==
+		VERITY_METADATA_MAGIC_NUMBER) ||
+		(le32_to_cpu(header->magic_number) ==
+		VERITY_METADATA_MAGIC_DISABLE)) {
+		DMERR("Incorrect magic number");
+		return retval;
+	}
+
+	if (le32_to_cpu(header->protocol_version) !=
+		VERITY_METADATA_VERSION) {
+		DMERR("Unsupported version %u",
+			le32_to_cpu(header->protocol_version));
+		return retval;
+	}
+
+	return 0;
+}
+
+static int verify_verity_signature(char *key_id,
+		struct android_metadata *metadata)
+{
+	key_ref_t key_ref;
+	struct key *key;
+	struct public_key_signature *pks = NULL;
+	int retval = -EINVAL;
+
+	key_ref = keyring_search(make_key_ref(system_trusted_keyring, 1),
+		&key_type_asymmetric, key_id);
+
+	if (IS_ERR(key_ref)) {
+		DMERR("keyring: key not found");
+		return -ENOKEY;
+	}
+
+	key = key_ref_to_ptr(key_ref);
+
+	pks = table_make_digest(PKEY_HASH_SHA256,
+			(const void *)metadata->verity_table,
+			le32_to_cpu(metadata->header->table_length));
+
+	if (IS_ERR(pks)) {
+		DMERR("hashing failed");
+		goto error;
+	}
+
+	retval = table_extract_mpi_array(pks, &metadata->header->signature[0],
+				RSANUMBYTES);
+	if (retval < 0) {
+		DMERR("Error extracting mpi %d", retval);
+		goto error;
+	}
+
+	retval = verify_signature(key, pks);
+	mpi_free(pks->rsa.s);
+error:
+	kfree(pks);
+	key_put(key);
+
+	return retval;
+}
+
+static void handle_error(void)
+{
+	int mode = verity_mode();
+	if (mode == DM_VERITY_MODE_RESTART) {
+		DMERR("triggering restart");
+		kernel_restart("dm-verity device corrupted");
+	} else {
+		DMERR("Mounting verity root failed");
+	}
+}
+
+static inline bool test_mult_overflow(sector_t a, u32 b)
+{
+	sector_t r = (sector_t)~0ULL;
+
+	sector_div(r, b);
+	return a > r;
+}
+
+/*
+ * Target parameters:
+ *	<key id>	Key id of the public key in the system keyring.
+ *			Verity metadata's signature would be verified against
+ *			this. If the key id contains spaces, replace them
+ *			with '#'.
+ *	<block device>	The block device for which dm-verity is being setup.
+ */
+static int android_verity_ctr(struct dm_target *ti, unsigned argc, char **argv)
+{
+	dev_t uninitialized_var(dev);
+	struct android_metadata *uninitialized_var(metadata);
+	int err = 0, i, mode;
+	char *key_id, *table_ptr, dummy,
+	*verity_table_args[VERITY_TABLE_ARGS + 2 + VERITY_TABLE_OPT_FEC_ARGS];
+	/* One for specifying number of opt args and one for mode */
+	sector_t data_sectors;
+	u32 data_block_size;
+	unsigned int major, minor,
+	no_of_args = VERITY_TABLE_ARGS + 2 + VERITY_TABLE_OPT_FEC_ARGS;
+	struct fec_header fec;
+	struct fec_ecc_metadata uninitialized_var(ecc);
+	char buf[FEC_ARG_LENGTH], *buf_ptr;
+	unsigned long long tmpll;
+
+	if (argc != 2) {
+		DMERR("Incorrect number of arguments");
+		handle_error();
+		return -EINVAL;
+	}
+
+	/* should come as one of the arguments for the verity target */
+	key_id = argv[0];
+	strreplace(argv[0], '#', ' ');
+
+	if (sscanf(argv[1], "%u:%u%c", &major, &minor, &dummy) == 2) {
+		dev = MKDEV(major, minor);
+		if (MAJOR(dev) != major || MINOR(dev) != minor) {
+			DMERR("Incorrect bdev major minor number");
+			handle_error();
+			return -EOVERFLOW;
+		}
+	}
+
+	DMINFO("key:%s dev:%s", argv[0], argv[1]);
+
+	if (extract_fec_header(dev, &fec, &ecc)) {
+		DMERR("Error while extracting fec header");
+		handle_error();
+		return -EINVAL;
+	}
+
+	metadata = extract_metadata(dev, &fec);
+
+	if (IS_ERR(metadata)) {
+		DMERR("Error while extracting metadata");
+		handle_error();
+		return -EINVAL;
+	}
+
+	err = verify_header(metadata->header);
+
+	if (err == VERITY_STATE_DISABLE) {
+		DMERR("Mounting root with verity disabled");
+		return -EINVAL;
+	} else if (err) {
+		DMERR("Verity header handle error");
+		handle_error();
+		goto free_metadata;
+	}
+
+	err = verify_verity_signature(key_id, metadata);
+
+	if (err) {
+		DMERR("Signature verification failed");
+		handle_error();
+		goto free_metadata;
+	} else
+		DMINFO("Signature verification success");
+
+	table_ptr = metadata->verity_table;
+
+	for (i = 0; i < VERITY_TABLE_ARGS; i++) {
+		verity_table_args[i] = strsep(&table_ptr, " ");
+		if (verity_table_args[i] == NULL)
+			break;
+	}
+
+	if (i != VERITY_TABLE_ARGS) {
+		DMERR("Verity table not in the expected format");
+		err = -EINVAL;
+		handle_error();
+		goto free_metadata;
+	}
+
+	if (sscanf(verity_table_args[5], "%llu%c", &tmpll, &dummy)
+							!= 1) {
+		DMERR("Verity table not in the expected format");
+		handle_error();
+		err = -EINVAL;
+		goto free_metadata;
+	}
+
+	if (tmpll > ULONG_MAX) {
+		DMERR("<num_data_blocks> too large. Forgot to turn on CONFIG_LBDAF?");
+		handle_error();
+		err = -EINVAL;
+		goto free_metadata;
+	}
+
+	data_sectors = tmpll;
+
+	if (sscanf(verity_table_args[3], "%u%c", &data_block_size, &dummy)
+								!= 1) {
+		DMERR("Verity table not in the expected format");
+		handle_error();
+		err = -EINVAL;
+		goto free_metadata;
+	}
+
+	if (test_mult_overflow(data_sectors, data_block_size >>
+							SECTOR_SHIFT)) {
+		DMERR("data_sectors too large");
+		handle_error();
+		err = -EOVERFLOW;
+		goto free_metadata;
+	}
+
+	data_sectors *= data_block_size >> SECTOR_SHIFT;
+	DMINFO("Data sectors %llu", (unsigned long long)data_sectors);
+
+	/* update target length */
+	ti->len = data_sectors;
+
+	/*substitute data_dev and hash_dev*/
+	verity_table_args[1] = argv[1];
+	verity_table_args[2] = argv[1];
+
+	mode = verity_mode();
+
+	if (ecc.valid && IS_BUILTIN(CONFIG_DM_VERITY_FEC)) {
+		if (mode) {
+			err = snprintf(buf, FEC_ARG_LENGTH,
+			"%u %s " VERITY_TABLE_OPT_FEC_FORMAT,
+			1 + VERITY_TABLE_OPT_FEC_ARGS,
+			mode == DM_VERITY_MODE_RESTART ?
+			VERITY_TABLE_OPT_RESTART : VERITY_TABLE_OPT_LOGGING,
+			argv[1], ecc.start / FEC_BLOCK_SIZE, ecc.blocks,
+			ecc.roots);
+		} else {
+			err = snprintf(buf, FEC_ARG_LENGTH,
+			"%u " VERITY_TABLE_OPT_FEC_FORMAT,
+			VERITY_TABLE_OPT_FEC_ARGS, argv[1],
+			ecc.start / FEC_BLOCK_SIZE, ecc.blocks, ecc.roots);
+		}
+	} else if (mode) {
+		err = snprintf(buf, FEC_ARG_LENGTH,
+			"2 " VERITY_TABLE_OPT_IGNZERO " %s",
+			mode == DM_VERITY_MODE_RESTART ?
+			VERITY_TABLE_OPT_RESTART : VERITY_TABLE_OPT_LOGGING);
+	} else {
+		err = snprintf(buf, FEC_ARG_LENGTH, "1 %s",
+				 "ignore_zero_blocks");
+	}
+
+	if (err < 0 || err >= FEC_ARG_LENGTH)
+		goto free_metadata;
+
+	buf_ptr = buf;
+
+	for (i = VERITY_TABLE_ARGS; i < (VERITY_TABLE_ARGS +
+		VERITY_TABLE_OPT_FEC_ARGS + 2); i++) {
+		verity_table_args[i] = strsep(&buf_ptr, " ");
+		if (verity_table_args[i] == NULL) {
+			no_of_args = i;
+			break;
+		}
+	}
+
+	err = verity_ctr(ti, no_of_args, verity_table_args);
+
+free_metadata:
+	kfree(metadata->header);
+	kfree(metadata->verity_table);
+	kfree(metadata);
+	return err;
+}
+
+static struct target_type android_verity_target = {
+	.name			= "android-verity",
+	.version		= {1, 0, 0},
+	.module			= THIS_MODULE,
+	.ctr			= android_verity_ctr,
+	.dtr			= verity_dtr,
+	.map			= verity_map,
+	.status			= verity_status,
+	.ioctl			= verity_ioctl,
+	.merge			= verity_merge,
+	.iterate_devices	= verity_iterate_devices,
+	.io_hints		= verity_io_hints,
+};
+
+static int __init dm_android_verity_init(void)
+{
+	int r;
+
+	r = dm_register_target(&android_verity_target);
+	if (r < 0)
+		DMERR("register failed %d", r);
+
+	return r;
+}
+
+static void __exit dm_android_verity_exit(void)
+{
+	dm_unregister_target(&android_verity_target);
+}
+
+module_init(dm_android_verity_init);
+module_exit(dm_android_verity_exit);
diff --git a/drivers/md/dm-android-verity.h b/drivers/md/dm-android-verity.h
new file mode 100644
index 0000000..11477ff
--- /dev/null
+++ b/drivers/md/dm-android-verity.h
@@ -0,0 +1,92 @@
+/*
+ * Copyright (C) 2015 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#ifndef DM_ANDROID_VERITY_H
+#define DM_ANDROID_VERITY_H
+
+#include <crypto/sha.h>
+
+#define RSANUMBYTES 256
+#define VERITY_METADATA_MAGIC_NUMBER 0xb001b001
+#define VERITY_METADATA_MAGIC_DISABLE 0x46464f56
+#define VERITY_METADATA_VERSION 0
+#define VERITY_STATE_DISABLE 1
+#define DATA_BLOCK_SIZE (4 * 1024)
+#define VERITY_METADATA_SIZE (8 * DATA_BLOCK_SIZE)
+#define VERITY_TABLE_ARGS 10
+#define VERITY_COMMANDLINE_PARAM_LENGTH 20
+
+#define FEC_MAGIC 0xFECFECFE
+#define FEC_BLOCK_SIZE (4 * 1024)
+#define FEC_VERSION 0
+#define FEC_RSM 255
+#define FEC_ARG_LENGTH 300
+
+#define VERITY_TABLE_OPT_RESTART "restart_on_corruption"
+#define VERITY_TABLE_OPT_LOGGING "ignore_corruption"
+#define VERITY_TABLE_OPT_IGNZERO "ignore_zero_blocks"
+
+#define VERITY_TABLE_OPT_FEC_FORMAT \
+	"use_fec_from_device %s fec_start %llu fec_blocks %llu fec_roots %u ignore_zero_blocks"
+#define VERITY_TABLE_OPT_FEC_ARGS 9
+
+#define VERITY_DEBUG 0
+
+#define DM_MSG_PREFIX                   "android-verity"
+/*
+ * There can be two formats.
+ * if fec is present
+ * <data_blocks> <verity_tree> <verity_metdata_32K><fec_data><fec_data_4K>
+ * if fec is not present
+ * <data_blocks> <verity_tree> <verity_metdata_32K>
+ */
+/* TODO: rearrange structure to reduce memory holes
+ * depends on userspace change.
+ */
+struct fec_header {
+	__le32 magic;
+	__le32 version;
+	__le32 size;
+	__le32 roots;
+	__le32 fec_size;
+	__le64 inp_size;
+	u8 hash[SHA256_DIGEST_SIZE];
+};
+
+struct android_metadata_header {
+	__le32 magic_number;
+	__le32 protocol_version;
+	char signature[RSANUMBYTES];
+	__le32 table_length;
+};
+
+struct android_metadata {
+	struct android_metadata_header *header;
+	char *verity_table;
+};
+
+struct fec_ecc_metadata {
+	bool valid;
+	u32 roots;
+	u64 blocks;
+	u64 rounds;
+	u64 start;
+};
+
+struct bio_read {
+	struct page **page_io;
+	int number_of_pages;
+};
+
+#endif /* DM_ANDROID_VERITY_H */
diff --git a/drivers/md/dm-verity-target.c b/drivers/md/dm-verity-target.c
index 0aba34a..1036270 100644
--- a/drivers/md/dm-verity-target.c
+++ b/drivers/md/dm-verity-target.c
@@ -551,7 +551,7 @@
  * Bio map function. It allocates dm_verity_io structure and bio vector and
  * fills them. Then it issues prefetches and the I/O.
  */
-static int verity_map(struct dm_target *ti, struct bio *bio)
+int verity_map(struct dm_target *ti, struct bio *bio)
 {
 	struct dm_verity *v = ti->private;
 	struct dm_verity_io *io;
@@ -596,7 +596,7 @@
 /*
  * Status: V (valid) or C (corruption found)
  */
-static void verity_status(struct dm_target *ti, status_type_t type,
+void verity_status(struct dm_target *ti, status_type_t type,
 			  unsigned status_flags, char *result, unsigned maxlen)
 {
 	struct dm_verity *v = ti->private;
@@ -669,7 +669,7 @@
 	return 0;
 }
 
-static int verity_iterate_devices(struct dm_target *ti,
+int verity_iterate_devices(struct dm_target *ti,
 				  iterate_devices_callout_fn fn, void *data)
 {
 	struct dm_verity *v = ti->private;
@@ -677,7 +677,7 @@
 	return fn(ti, v->data_dev, v->data_start, ti->len, data);
 }
 
-static void verity_io_hints(struct dm_target *ti, struct queue_limits *limits)
+void verity_io_hints(struct dm_target *ti, struct queue_limits *limits)
 {
 	struct dm_verity *v = ti->private;
 
@@ -690,7 +690,7 @@
 	blk_limits_io_min(limits, limits->logical_block_size);
 }
 
-static void verity_dtr(struct dm_target *ti)
+void verity_dtr(struct dm_target *ti)
 {
 	struct dm_verity *v = ti->private;
 
@@ -817,7 +817,7 @@
  *	<digest>
  *	<salt>		Hex string or "-" if no salt.
  */
-static int verity_ctr(struct dm_target *ti, unsigned argc, char **argv)
+int verity_ctr(struct dm_target *ti, unsigned argc, char **argv)
 {
 	struct dm_verity *v;
 	struct dm_arg_set as;
diff --git a/drivers/md/dm-verity.h b/drivers/md/dm-verity.h
index fb419f4..d9cf5e4 100644
--- a/drivers/md/dm-verity.h
+++ b/drivers/md/dm-verity.h
@@ -126,4 +126,16 @@
 extern int verity_hash_for_block(struct dm_verity *v, struct dm_verity_io *io,
 				 sector_t block, u8 *digest, bool *is_zero);
 
+extern void verity_status(struct dm_target *ti, status_type_t type,
+			unsigned status_flags, char *result, unsigned maxlen);
+extern int verity_ioctl(struct dm_target *ti, unsigned cmd,
+			unsigned long arg);
+extern int verity_merge(struct dm_target *ti, struct bvec_merge_data *bvm,
+			struct bio_vec *biovec, int max_size);
+extern int verity_iterate_devices(struct dm_target *ti,
+				iterate_devices_callout_fn fn, void *data);
+extern void verity_io_hints(struct dm_target *ti, struct queue_limits *limits);
+extern void verity_dtr(struct dm_target *ti);
+extern int verity_ctr(struct dm_target *ti, unsigned argc, char **argv);
+extern int verity_map(struct dm_target *ti, struct bio *bio);
 #endif /* DM_VERITY_H */