block/t10-pi.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * t10_pi.c - Functions for generating and verifying T10 Protection
  *	      Information.
  */

 #include <linux/t10-pi.h>
 #include <linux/blkdev.h>
 #include <linux/crc-t10dif.h>
 #include <net/checksum.h>

 typedef __be16 (csum_fn) (void *, unsigned int);

 static __be16 t10_pi_crc_fn(void *data, unsigned int len)
 {
 	return cpu_to_be16(crc_t10dif(data, len));
 }

 static __be16 t10_pi_ip_fn(void *data, unsigned int len)
 {
 	return (__force __be16)ip_compute_csum(data, len);
 }

 /*
  * Type 1 and Type 2 protection use the same format: 16 bit guard tag,
  * 16 bit app tag, 32 bit reference tag. Type 3 does not define the ref
  * tag.
  */
 static blk_status_t t10_pi_generate(struct blk_integrity_iter *iter,
 		csum_fn *fn, unsigned int type)
 {
 	unsigned int i;

 	for (i = 0 ; i < iter->data_size ; i += iter->interval) {
 		struct t10_pi_tuple *pi = iter->prot_buf;

 		pi->guard_tag = fn(iter->data_buf, iter->interval);
 		pi->app_tag = 0;

 		if (type == 1)
 			pi->ref_tag = cpu_to_be32(lower_32_bits(iter->seed));
 		else
 			pi->ref_tag = 0;

 		iter->data_buf += iter->interval;
 		iter->prot_buf += sizeof(struct t10_pi_tuple);
 		iter->seed++;
 	}

 	return BLK_STS_OK;
 }

 static blk_status_t t10_pi_verify(struct blk_integrity_iter *iter,
 		csum_fn *fn, unsigned int type)
 {
 	unsigned int i;

 	for (i = 0 ; i < iter->data_size ; i += iter->interval) {
 		struct t10_pi_tuple *pi = iter->prot_buf;
 		__be16 csum;

 		switch (type) {
 		case 1:
 		case 2:
 			if (pi->app_tag == T10_PI_APP_ESCAPE)
 				goto next;

 			if (be32_to_cpu(pi->ref_tag) !=
 			    lower_32_bits(iter->seed)) {
 				pr_err("%s: ref tag error at location %llu " \
 				       "(rcvd %u)\n", iter->disk_name,
 				       (unsigned long long)
 				       iter->seed, be32_to_cpu(pi->ref_tag));
 				return BLK_STS_PROTECTION;
 			}
 			break;
 		case 3:
 			if (pi->app_tag == T10_PI_APP_ESCAPE &&
 			    pi->ref_tag == T10_PI_REF_ESCAPE)
 				goto next;
 			break;
 		}

 		csum = fn(iter->data_buf, iter->interval);

 		if (pi->guard_tag != csum) {
 			pr_err("%s: guard tag error at sector %llu " \
 			       "(rcvd %04x, want %04x)\n", iter->disk_name,
 			       (unsigned long long)iter->seed,
 			       be16_to_cpu(pi->guard_tag), be16_to_cpu(csum));
 			return BLK_STS_PROTECTION;
 		}

 next:
 		iter->data_buf += iter->interval;
 		iter->prot_buf += sizeof(struct t10_pi_tuple);
 		iter->seed++;
 	}

 	return BLK_STS_OK;
 }

 static blk_status_t t10_pi_type1_generate_crc(struct blk_integrity_iter *iter)
 {
 	return t10_pi_generate(iter, t10_pi_crc_fn, 1);
 }

 static blk_status_t t10_pi_type1_generate_ip(struct blk_integrity_iter *iter)
 {
 	return t10_pi_generate(iter, t10_pi_ip_fn, 1);
 }

 static blk_status_t t10_pi_type1_verify_crc(struct blk_integrity_iter *iter)
 {
 	return t10_pi_verify(iter, t10_pi_crc_fn, 1);
 }

 static blk_status_t t10_pi_type1_verify_ip(struct blk_integrity_iter *iter)
 {
 	return t10_pi_verify(iter, t10_pi_ip_fn, 1);
 }

 static blk_status_t t10_pi_type3_generate_crc(struct blk_integrity_iter *iter)
 {
 	return t10_pi_generate(iter, t10_pi_crc_fn, 3);
 }

 static blk_status_t t10_pi_type3_generate_ip(struct blk_integrity_iter *iter)
 {
 	return t10_pi_generate(iter, t10_pi_ip_fn, 3);
 }

 static blk_status_t t10_pi_type3_verify_crc(struct blk_integrity_iter *iter)
 {
 	return t10_pi_verify(iter, t10_pi_crc_fn, 3);
 }

 static blk_status_t t10_pi_type3_verify_ip(struct blk_integrity_iter *iter)
 {
 	return t10_pi_verify(iter, t10_pi_ip_fn, 3);
 }

 const struct blk_integrity_profile t10_pi_type1_crc = {
 	.name			= "T10-DIF-TYPE1-CRC",
 	.generate_fn		= t10_pi_type1_generate_crc,
 	.verify_fn		= t10_pi_type1_verify_crc,
 };
 EXPORT_SYMBOL(t10_pi_type1_crc);

 const struct blk_integrity_profile t10_pi_type1_ip = {
 	.name			= "T10-DIF-TYPE1-IP",
 	.generate_fn		= t10_pi_type1_generate_ip,
 	.verify_fn		= t10_pi_type1_verify_ip,
 };
 EXPORT_SYMBOL(t10_pi_type1_ip);

 const struct blk_integrity_profile t10_pi_type3_crc = {
 	.name			= "T10-DIF-TYPE3-CRC",
 	.generate_fn		= t10_pi_type3_generate_crc,
 	.verify_fn		= t10_pi_type3_verify_crc,
 };
 EXPORT_SYMBOL(t10_pi_type3_crc);

 const struct blk_integrity_profile t10_pi_type3_ip = {
 	.name			= "T10-DIF-TYPE3-IP",
 	.generate_fn		= t10_pi_type3_generate_ip,
 	.verify_fn		= t10_pi_type3_verify_ip,
 };
 EXPORT_SYMBOL(t10_pi_type3_ip);

 /**
  * t10_pi_prepare - prepare PI prior submitting request to device
  * @rq:              request with PI that should be prepared
  * @protection_type: PI type (Type 1/Type 2/Type 3)
  *
  * For Type 1/Type 2, the virtual start sector is the one that was
  * originally submitted by the block layer for the ref_tag usage. Due to
  * partitioning, MD/DM cloning, etc. the actual physical start sector is
  * likely to be different. Remap protection information to match the
  * physical LBA.
  *
  * Type 3 does not have a reference tag so no remapping is required.
  */
 void t10_pi_prepare(struct request *rq, u8 protection_type)
 {
 	const int tuple_sz = rq->q->integrity.tuple_size;
 	u32 ref_tag = t10_pi_ref_tag(rq);
 	struct bio *bio;

 	if (protection_type == T10_PI_TYPE3_PROTECTION)
 		return;

 	__rq_for_each_bio(bio, rq) {
 		struct bio_integrity_payload *bip = bio_integrity(bio);
 		u32 virt = bip_get_seed(bip) & 0xffffffff;
 		struct bio_vec iv;
 		struct bvec_iter iter;

 		/* Already remapped? */
 		if (bip->bip_flags & BIP_MAPPED_INTEGRITY)
 			break;

 		bip_for_each_vec(iv, bip, iter) {
 			void *p, *pmap;
 			unsigned int j;

 			pmap = kmap_atomic(iv.bv_page);
 			p = pmap + iv.bv_offset;
 			for (j = 0; j < iv.bv_len; j += tuple_sz) {
 				struct t10_pi_tuple *pi = p;

 				if (be32_to_cpu(pi->ref_tag) == virt)
 					pi->ref_tag = cpu_to_be32(ref_tag);
 				virt++;
 				ref_tag++;
 				p += tuple_sz;
 			}

 			kunmap_atomic(pmap);
 		}

 		bip->bip_flags |= BIP_MAPPED_INTEGRITY;
 	}
 }
 EXPORT_SYMBOL(t10_pi_prepare);

 /**
  * t10_pi_complete - prepare PI prior returning request to the block layer
  * @rq:              request with PI that should be prepared
  * @protection_type: PI type (Type 1/Type 2/Type 3)
  * @intervals:       total elements to prepare
  *
  * For Type 1/Type 2, the virtual start sector is the one that was
  * originally submitted by the block layer for the ref_tag usage. Due to
  * partitioning, MD/DM cloning, etc. the actual physical start sector is
  * likely to be different. Since the physical start sector was submitted
  * to the device, we should remap it back to virtual values expected by the
  * block layer.
  *
  * Type 3 does not have a reference tag so no remapping is required.
  */
 void t10_pi_complete(struct request *rq, u8 protection_type,
 		     unsigned int intervals)
 {
 	const int tuple_sz = rq->q->integrity.tuple_size;
 	u32 ref_tag = t10_pi_ref_tag(rq);
 	struct bio *bio;

 	if (protection_type == T10_PI_TYPE3_PROTECTION)
 		return;

 	__rq_for_each_bio(bio, rq) {
 		struct bio_integrity_payload *bip = bio_integrity(bio);
 		u32 virt = bip_get_seed(bip) & 0xffffffff;
 		struct bio_vec iv;
 		struct bvec_iter iter;

 		bip_for_each_vec(iv, bip, iter) {
 			void *p, *pmap;
 			unsigned int j;

 			pmap = kmap_atomic(iv.bv_page);
 			p = pmap + iv.bv_offset;
 			for (j = 0; j < iv.bv_len && intervals; j += tuple_sz) {
 				struct t10_pi_tuple *pi = p;

 				if (be32_to_cpu(pi->ref_tag) == ref_tag)
 					pi->ref_tag = cpu_to_be32(virt);
 				virt++;
 				ref_tag++;
 				intervals--;
 				p += tuple_sz;
 			}

 			kunmap_atomic(pmap);
 		}
 	}
 }
 EXPORT_SYMBOL(t10_pi_complete);
	// SPDX-License-Identifier: GPL-2.0
	/*
	* t10_pi.c - Functions for generating and verifying T10 Protection
	* Information.
	*/

	#include <linux/t10-pi.h>
	#include <linux/blkdev.h>
	#include <linux/crc-t10dif.h>
	#include <net/checksum.h>

	typedef __be16 (csum_fn) (void *, unsigned int);

	static __be16 t10_pi_crc_fn(void *data, unsigned int len)
	{
	return cpu_to_be16(crc_t10dif(data, len));
	}

	static __be16 t10_pi_ip_fn(void *data, unsigned int len)
	{
	return (__force __be16)ip_compute_csum(data, len);
	}

	/*
	* Type 1 and Type 2 protection use the same format: 16 bit guard tag,
	* 16 bit app tag, 32 bit reference tag. Type 3 does not define the ref
	* tag.
	*/
	static blk_status_t t10_pi_generate(struct blk_integrity_iter *iter,
	csum_fn *fn, unsigned int type)
	{
	unsigned int i;

	for (i = 0 ; i < iter->data_size ; i += iter->interval) {
	struct t10_pi_tuple *pi = iter->prot_buf;

	pi->guard_tag = fn(iter->data_buf, iter->interval);
	pi->app_tag = 0;

	if (type == 1)
	pi->ref_tag = cpu_to_be32(lower_32_bits(iter->seed));
	else
	pi->ref_tag = 0;

	iter->data_buf += iter->interval;
	iter->prot_buf += sizeof(struct t10_pi_tuple);
	iter->seed++;
	}

	return BLK_STS_OK;
	}

	static blk_status_t t10_pi_verify(struct blk_integrity_iter *iter,
	csum_fn *fn, unsigned int type)
	{
	unsigned int i;

	for (i = 0 ; i < iter->data_size ; i += iter->interval) {
	struct t10_pi_tuple *pi = iter->prot_buf;
	__be16 csum;

	switch (type) {
	case 1:
	case 2:
	if (pi->app_tag == T10_PI_APP_ESCAPE)
	goto next;

	if (be32_to_cpu(pi->ref_tag) !=
	lower_32_bits(iter->seed)) {
	pr_err("%s: ref tag error at location %llu " \
	"(rcvd %u)\n", iter->disk_name,
	(unsigned long long)
	iter->seed, be32_to_cpu(pi->ref_tag));
	return BLK_STS_PROTECTION;
	}
	break;
	case 3:
	if (pi->app_tag == T10_PI_APP_ESCAPE &&
	pi->ref_tag == T10_PI_REF_ESCAPE)
	goto next;
	break;
	}

	csum = fn(iter->data_buf, iter->interval);

	if (pi->guard_tag != csum) {
	pr_err("%s: guard tag error at sector %llu " \
	"(rcvd %04x, want %04x)\n", iter->disk_name,
	(unsigned long long)iter->seed,
	be16_to_cpu(pi->guard_tag), be16_to_cpu(csum));
	return BLK_STS_PROTECTION;
	}

	next:
	iter->data_buf += iter->interval;
	iter->prot_buf += sizeof(struct t10_pi_tuple);
	iter->seed++;
	}

	return BLK_STS_OK;
	}

	static blk_status_t t10_pi_type1_generate_crc(struct blk_integrity_iter *iter)
	{
	return t10_pi_generate(iter, t10_pi_crc_fn, 1);
	}

	static blk_status_t t10_pi_type1_generate_ip(struct blk_integrity_iter *iter)
	{
	return t10_pi_generate(iter, t10_pi_ip_fn, 1);
	}

	static blk_status_t t10_pi_type1_verify_crc(struct blk_integrity_iter *iter)
	{
	return t10_pi_verify(iter, t10_pi_crc_fn, 1);
	}

	static blk_status_t t10_pi_type1_verify_ip(struct blk_integrity_iter *iter)
	{
	return t10_pi_verify(iter, t10_pi_ip_fn, 1);
	}

	static blk_status_t t10_pi_type3_generate_crc(struct blk_integrity_iter *iter)
	{
	return t10_pi_generate(iter, t10_pi_crc_fn, 3);
	}

	static blk_status_t t10_pi_type3_generate_ip(struct blk_integrity_iter *iter)
	{
	return t10_pi_generate(iter, t10_pi_ip_fn, 3);
	}

	static blk_status_t t10_pi_type3_verify_crc(struct blk_integrity_iter *iter)
	{
	return t10_pi_verify(iter, t10_pi_crc_fn, 3);
	}

	static blk_status_t t10_pi_type3_verify_ip(struct blk_integrity_iter *iter)
	{
	return t10_pi_verify(iter, t10_pi_ip_fn, 3);
	}

	const struct blk_integrity_profile t10_pi_type1_crc = {
	.name = "T10-DIF-TYPE1-CRC",
	.generate_fn = t10_pi_type1_generate_crc,
	.verify_fn = t10_pi_type1_verify_crc,
	};
	EXPORT_SYMBOL(t10_pi_type1_crc);

	const struct blk_integrity_profile t10_pi_type1_ip = {
	.name = "T10-DIF-TYPE1-IP",
	.generate_fn = t10_pi_type1_generate_ip,
	.verify_fn = t10_pi_type1_verify_ip,
	};
	EXPORT_SYMBOL(t10_pi_type1_ip);

	const struct blk_integrity_profile t10_pi_type3_crc = {
	.name = "T10-DIF-TYPE3-CRC",
	.generate_fn = t10_pi_type3_generate_crc,
	.verify_fn = t10_pi_type3_verify_crc,
	};
	EXPORT_SYMBOL(t10_pi_type3_crc);

	const struct blk_integrity_profile t10_pi_type3_ip = {
	.name = "T10-DIF-TYPE3-IP",
	.generate_fn = t10_pi_type3_generate_ip,
	.verify_fn = t10_pi_type3_verify_ip,
	};
	EXPORT_SYMBOL(t10_pi_type3_ip);

	/**
	* t10_pi_prepare - prepare PI prior submitting request to device
	* @rq: request with PI that should be prepared
	* @protection_type: PI type (Type 1/Type 2/Type 3)
	*
	* For Type 1/Type 2, the virtual start sector is the one that was
	* originally submitted by the block layer for the ref_tag usage. Due to
	* partitioning, MD/DM cloning, etc. the actual physical start sector is
	* likely to be different. Remap protection information to match the
	* physical LBA.
	*
	* Type 3 does not have a reference tag so no remapping is required.
	*/
	void t10_pi_prepare(struct request *rq, u8 protection_type)
	{
	const int tuple_sz = rq->q->integrity.tuple_size;
	u32 ref_tag = t10_pi_ref_tag(rq);
	struct bio *bio;

	if (protection_type == T10_PI_TYPE3_PROTECTION)
	return;

	__rq_for_each_bio(bio, rq) {
	struct bio_integrity_payload *bip = bio_integrity(bio);
	u32 virt = bip_get_seed(bip) & 0xffffffff;
	struct bio_vec iv;
	struct bvec_iter iter;

	/* Already remapped? */
	if (bip->bip_flags & BIP_MAPPED_INTEGRITY)
	break;

	bip_for_each_vec(iv, bip, iter) {
	void p, pmap;
	unsigned int j;

	pmap = kmap_atomic(iv.bv_page);
	p = pmap + iv.bv_offset;
	for (j = 0; j < iv.bv_len; j += tuple_sz) {
	struct t10_pi_tuple *pi = p;

	if (be32_to_cpu(pi->ref_tag) == virt)
	pi->ref_tag = cpu_to_be32(ref_tag);
	virt++;
	ref_tag++;
	p += tuple_sz;
	}

	kunmap_atomic(pmap);
	}

	bip->bip_flags \|= BIP_MAPPED_INTEGRITY;
	}
	}
	EXPORT_SYMBOL(t10_pi_prepare);

	/**
	* t10_pi_complete - prepare PI prior returning request to the block layer
	* @rq: request with PI that should be prepared
	* @protection_type: PI type (Type 1/Type 2/Type 3)
	* @intervals: total elements to prepare
	*
	* For Type 1/Type 2, the virtual start sector is the one that was
	* originally submitted by the block layer for the ref_tag usage. Due to
	* partitioning, MD/DM cloning, etc. the actual physical start sector is
	* likely to be different. Since the physical start sector was submitted
	* to the device, we should remap it back to virtual values expected by the
	* block layer.
	*
	* Type 3 does not have a reference tag so no remapping is required.
	*/
	void t10_pi_complete(struct request *rq, u8 protection_type,
	unsigned int intervals)
	{
	const int tuple_sz = rq->q->integrity.tuple_size;
	u32 ref_tag = t10_pi_ref_tag(rq);
	struct bio *bio;

	if (protection_type == T10_PI_TYPE3_PROTECTION)
	return;

	__rq_for_each_bio(bio, rq) {
	struct bio_integrity_payload *bip = bio_integrity(bio);
	u32 virt = bip_get_seed(bip) & 0xffffffff;
	struct bio_vec iv;
	struct bvec_iter iter;

	bip_for_each_vec(iv, bip, iter) {
	void p, pmap;
	unsigned int j;

	pmap = kmap_atomic(iv.bv_page);
	p = pmap + iv.bv_offset;
	for (j = 0; j < iv.bv_len && intervals; j += tuple_sz) {
	struct t10_pi_tuple *pi = p;

	if (be32_to_cpu(pi->ref_tag) == ref_tag)
	pi->ref_tag = cpu_to_be32(virt);
	virt++;
	ref_tag++;
	intervals--;
	p += tuple_sz;
	}

	kunmap_atomic(pmap);
	}
	}
	}
	EXPORT_SYMBOL(t10_pi_complete);