Commit 2341c2f8 authored by Martin K. Petersen's avatar Martin K. Petersen Committed by Jens Axboe
Browse files

block: Add T10 Protection Information functions 



The T10 Protection Information format is also used by some devices that
do not go through the SCSI layer (virtual block devices, NVMe). Relocate
the relevant functions to a block layer library that can be used without
involving SCSI.

Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 4eaf99be

block/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -77,6 +77,7 @@ config BLK_DEV_BSGLIB 


config BLK_DEV_INTEGRITY

	bool "Block layer data integrity support"

	select CRC_T10DIF if BLK_DEV_INTEGRITY

	---help---

	Some storage devices allow extra information to be

	stored/retrieved to help protect the data.  The block layer

block/Makefile

+2 −2
Original line number Diff line number Diff line
@@ -20,6 +20,6 @@ obj-$(CONFIG_IOSCHED_DEADLINE) += deadline-iosched.o 
obj-$(CONFIG_IOSCHED_CFQ)	+= cfq-iosched.o



obj-$(CONFIG_BLOCK_COMPAT)	+= compat_ioctl.o

obj-$(CONFIG_BLK_DEV_INTEGRITY)	+= blk-integrity.o

obj-$(CONFIG_BLK_CMDLINE_PARSER)	+= cmdline-parser.o

obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o
 
obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o blk-integrity.o t10-pi.o

block/t10-pi.c

0 → 100644
+197 −0
Original line number Diff line number Diff line 
/*

 * t10_pi.c - Functions for generating and verifying T10 Protection

 *	      Information.

 *

 * Copyright (C) 2007, 2008, 2014 Oracle Corporation

 * Written by: Martin K. Petersen <martin.petersen@oracle.com>

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License version

 * 2 as published by the Free Software Foundation.

 *

 * 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.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; see the file COPYING.  If not, write to

 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,

 * USA.

 *

 */



#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 const __be16 APP_ESCAPE = (__force __be16) 0xffff;

static const __be32 REF_ESCAPE = (__force __be32) 0xffffffff;



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 int 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 0;

}



static int 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 == 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 -EILSEQ;

			}

			break;

		case 3:

			if (pi->app_tag == APP_ESCAPE &&

			    pi->ref_tag == 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 -EILSEQ;

		}



next:

		iter->data_buf += iter->interval;

		iter->prot_buf += sizeof(struct t10_pi_tuple);

		iter->seed++;

	}



	return 0;

}



static int t10_pi_type1_generate_crc(struct blk_integrity_iter *iter)

{

	return t10_pi_generate(iter, t10_pi_crc_fn, 1);

}



static int t10_pi_type1_generate_ip(struct blk_integrity_iter *iter)

{

	return t10_pi_generate(iter, t10_pi_ip_fn, 1);

}



static int t10_pi_type1_verify_crc(struct blk_integrity_iter *iter)

{

	return t10_pi_verify(iter, t10_pi_crc_fn, 1);

}



static int t10_pi_type1_verify_ip(struct blk_integrity_iter *iter)

{

	return t10_pi_verify(iter, t10_pi_ip_fn, 1);

}



static int t10_pi_type3_generate_crc(struct blk_integrity_iter *iter)

{

	return t10_pi_generate(iter, t10_pi_crc_fn, 3);

}



static int t10_pi_type3_generate_ip(struct blk_integrity_iter *iter)

{

	return t10_pi_generate(iter, t10_pi_ip_fn, 3);

}



static int t10_pi_type3_verify_crc(struct blk_integrity_iter *iter)

{

	return t10_pi_verify(iter, t10_pi_crc_fn, 3);

}



static int t10_pi_type3_verify_ip(struct blk_integrity_iter *iter)

{

	return t10_pi_verify(iter, t10_pi_ip_fn, 3);

}



struct blk_integrity t10_pi_type1_crc = {

	.name			= "T10-DIF-TYPE1-CRC",

	.generate_fn		= t10_pi_type1_generate_crc,

	.verify_fn		= t10_pi_type1_verify_crc,

	.tuple_size		= sizeof(struct t10_pi_tuple),

	.tag_size		= 0,

};

EXPORT_SYMBOL(t10_pi_type1_crc);



struct blk_integrity t10_pi_type1_ip = {

	.name			= "T10-DIF-TYPE1-IP",

	.generate_fn		= t10_pi_type1_generate_ip,

	.verify_fn		= t10_pi_type1_verify_ip,

	.tuple_size		= sizeof(struct t10_pi_tuple),

	.tag_size		= 0,

};

EXPORT_SYMBOL(t10_pi_type1_ip);



struct blk_integrity t10_pi_type3_crc = {

	.name			= "T10-DIF-TYPE3-CRC",

	.generate_fn		= t10_pi_type3_generate_crc,

	.verify_fn		= t10_pi_type3_verify_crc,

	.tuple_size		= sizeof(struct t10_pi_tuple),

	.tag_size		= 0,

};

EXPORT_SYMBOL(t10_pi_type3_crc);



struct blk_integrity t10_pi_type3_ip = {

	.name			= "T10-DIF-TYPE3-IP",

	.generate_fn		= t10_pi_type3_generate_ip,

	.verify_fn		= t10_pi_type3_verify_ip,

	.tuple_size		= sizeof(struct t10_pi_tuple),

	.tag_size		= 0,

};

EXPORT_SYMBOL(t10_pi_type3_ip);

drivers/scsi/Kconfig

+0 −1
Original line number Diff line number Diff line
@@ -62,7 +62,6 @@ comment "SCSI support type (disk, tape, CD-ROM)" 
config BLK_DEV_SD

	tristate "SCSI disk support"

	depends on SCSI

	select CRC_T10DIF if BLK_DEV_INTEGRITY

	---help---

	  If you want to use SCSI hard disks, Fibre Channel disks,

	  Serial ATA (SATA) or Parallel ATA (PATA) hard disks,

drivers/scsi/sd_dif.c

+20 −221
Original line number Diff line number Diff line
@@ -21,7 +21,7 @@ 
 */



#include <linux/blkdev.h>

#include <linux/crc-t10dif.h>

#include <linux/t10-pi.h>



#include <scsi/scsi.h>

#include <scsi/scsi_cmnd.h>
@@ -33,207 +33,8 @@ 
#include <scsi/scsi_ioctl.h>

#include <scsi/scsicam.h>



#include <net/checksum.h>



#include "sd.h"



typedef __u16 (csum_fn) (void *, unsigned int);



static __u16 sd_dif_crc_fn(void *data, unsigned int len)

{

	return cpu_to_be16(crc_t10dif(data, len));

}



static __u16 sd_dif_ip_fn(void *data, unsigned int len)

{

	return 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.

 */

static void sd_dif_type1_generate(struct blk_integrity_iter *iter, csum_fn *fn)

{

	void *buf = iter->data_buf;

	struct sd_dif_tuple *sdt = iter->prot_buf;

	sector_t seed = iter->seed;

	unsigned int i;



	for (i = 0 ; i < iter->data_size ; i += iter->interval, sdt++) {

		sdt->guard_tag = fn(buf, iter->interval);

		sdt->ref_tag = cpu_to_be32(seed & 0xffffffff);

		sdt->app_tag = 0;



		buf += iter->interval;

		seed++;

	}

}



static int sd_dif_type1_generate_crc(struct blk_integrity_iter *iter)

{

	sd_dif_type1_generate(iter, sd_dif_crc_fn);

	return 0;

}



static int sd_dif_type1_generate_ip(struct blk_integrity_iter *iter)

{

	sd_dif_type1_generate(iter, sd_dif_ip_fn);

	return 0;

}



static int sd_dif_type1_verify(struct blk_integrity_iter *iter, csum_fn *fn)

{

	void *buf = iter->data_buf;

	struct sd_dif_tuple *sdt = iter->prot_buf;

	sector_t seed = iter->seed;

	unsigned int i;

	__u16 csum;



	for (i = 0 ; i < iter->data_size ; i += iter->interval, sdt++) {

		/* Unwritten sectors */

		if (sdt->app_tag == 0xffff)

			return 0;



		if (be32_to_cpu(sdt->ref_tag) != (seed & 0xffffffff)) {

			printk(KERN_ERR

			       "%s: ref tag error on sector %lu (rcvd %u)\n",

			       iter->disk_name, (unsigned long)seed,

			       be32_to_cpu(sdt->ref_tag));

			return -EIO;

		}



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



		if (sdt->guard_tag != csum) {

			printk(KERN_ERR "%s: guard tag error on sector %lu " \

			       "(rcvd %04x, data %04x)\n", iter->disk_name,

			       (unsigned long)seed,

			       be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));

			return -EIO;

		}



		buf += iter->interval;

		seed++;

	}



	return 0;

}



static int sd_dif_type1_verify_crc(struct blk_integrity_iter *iter)

{

	return sd_dif_type1_verify(iter, sd_dif_crc_fn);

}



static int sd_dif_type1_verify_ip(struct blk_integrity_iter *iter)

{

	return sd_dif_type1_verify(iter, sd_dif_ip_fn);

}



static struct blk_integrity dif_type1_integrity_crc = {

	.name			= "T10-DIF-TYPE1-CRC",

	.generate_fn		= sd_dif_type1_generate_crc,

	.verify_fn		= sd_dif_type1_verify_crc,

	.tuple_size		= sizeof(struct sd_dif_tuple),

	.tag_size		= 0,

};



static struct blk_integrity dif_type1_integrity_ip = {

	.name			= "T10-DIF-TYPE1-IP",

	.generate_fn		= sd_dif_type1_generate_ip,

	.verify_fn		= sd_dif_type1_verify_ip,

	.tuple_size		= sizeof(struct sd_dif_tuple),

	.tag_size		= 0,

};





/*

 * Type 3 protection has a 16-bit guard tag and 16 + 32 bits of opaque

 * tag space.

 */

static void sd_dif_type3_generate(struct blk_integrity_iter *iter, csum_fn *fn)

{

	void *buf = iter->data_buf;

	struct sd_dif_tuple *sdt = iter->prot_buf;

	unsigned int i;



	for (i = 0 ; i < iter->data_size ; i += iter->interval, sdt++) {

		sdt->guard_tag = fn(buf, iter->interval);

		sdt->ref_tag = 0;

		sdt->app_tag = 0;



		buf += iter->interval;

	}

}



static int sd_dif_type3_generate_crc(struct blk_integrity_iter *iter)

{

	sd_dif_type3_generate(iter, sd_dif_crc_fn);

	return 0;

}



static int sd_dif_type3_generate_ip(struct blk_integrity_iter *iter)

{

	sd_dif_type3_generate(iter, sd_dif_ip_fn);

	return 0;

}



static int sd_dif_type3_verify(struct blk_integrity_iter *iter, csum_fn *fn)

{

	void *buf = iter->data_buf;

	struct sd_dif_tuple *sdt = iter->prot_buf;

	sector_t seed = iter->seed;

	unsigned int i;

	__u16 csum;



	for (i = 0 ; i < iter->data_size ; i += iter->interval, sdt++) {

		/* Unwritten sectors */

		if (sdt->app_tag == 0xffff && sdt->ref_tag == 0xffffffff)

			return 0;



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



		if (sdt->guard_tag != csum) {

			printk(KERN_ERR "%s: guard tag error on sector %lu " \

			       "(rcvd %04x, data %04x)\n", iter->disk_name,

			       (unsigned long)seed,

			       be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));

			return -EIO;

		}



		buf += iter->interval;

		seed++;

	}



	return 0;

}



static int sd_dif_type3_verify_crc(struct blk_integrity_iter *iter)

{

	return sd_dif_type3_verify(iter, sd_dif_crc_fn);

}



static int sd_dif_type3_verify_ip(struct blk_integrity_iter *iter)

{

	return sd_dif_type3_verify(iter, sd_dif_ip_fn);

}



static struct blk_integrity dif_type3_integrity_crc = {

	.name			= "T10-DIF-TYPE3-CRC",

	.generate_fn		= sd_dif_type3_generate_crc,

	.verify_fn		= sd_dif_type3_verify_crc,

	.tuple_size		= sizeof(struct sd_dif_tuple),

	.tag_size		= 0,

};



static struct blk_integrity dif_type3_integrity_ip = {

	.name			= "T10-DIF-TYPE3-IP",

	.generate_fn		= sd_dif_type3_generate_ip,

	.verify_fn		= sd_dif_type3_verify_ip,

	.tuple_size		= sizeof(struct sd_dif_tuple),

	.tag_size		= 0,

};



/*

 * Configure exchange of protection information between OS and HBA.

 */
@@ -257,16 +58,16 @@ void sd_dif_config_host(struct scsi_disk *sdkp) 
	/* Enable DMA of protection information */

	if (scsi_host_get_guard(sdkp->device->host) & SHOST_DIX_GUARD_IP) {

		if (type == SD_DIF_TYPE3_PROTECTION)

			blk_integrity_register(disk, &dif_type3_integrity_ip);

			blk_integrity_register(disk, &t10_pi_type3_ip);

		else

			blk_integrity_register(disk, &dif_type1_integrity_ip);

			blk_integrity_register(disk, &t10_pi_type1_ip);



		disk->integrity->flags |= BLK_INTEGRITY_IP_CHECKSUM;

	} else

		if (type == SD_DIF_TYPE3_PROTECTION)

			blk_integrity_register(disk, &dif_type3_integrity_crc);

			blk_integrity_register(disk, &t10_pi_type3_crc);

		else

			blk_integrity_register(disk, &dif_type1_integrity_crc);

			blk_integrity_register(disk, &t10_pi_type1_crc);



	sd_printk(KERN_NOTICE, sdkp,

		  "Enabling DIX %s protection\n", disk->integrity->name);
@@ -308,10 +109,10 @@ void sd_dif_config_host(struct scsi_disk *sdkp) 
void sd_dif_prepare(struct request *rq, sector_t hw_sector,

		    unsigned int sector_sz)

{

	const int tuple_sz = sizeof(struct sd_dif_tuple);

	const int tuple_sz = sizeof(struct t10_pi_tuple);

	struct bio *bio;

	struct scsi_disk *sdkp;

	struct sd_dif_tuple *sdt;

	struct t10_pi_tuple *pi;

	u32 phys, virt;



	sdkp = rq->bio->bi_bdev->bd_disk->private_data;
@@ -334,19 +135,18 @@ void sd_dif_prepare(struct request *rq, sector_t hw_sector, 
		virt = bip_get_seed(bip) & 0xffffffff;



		bip_for_each_vec(iv, bip, iter) {

			sdt = kmap_atomic(iv.bv_page)

				+ iv.bv_offset;

			pi = kmap_atomic(iv.bv_page) + iv.bv_offset;



			for (j = 0; j < iv.bv_len; j += tuple_sz, sdt++) {

			for (j = 0; j < iv.bv_len; j += tuple_sz, pi++) {



				if (be32_to_cpu(sdt->ref_tag) == virt)

					sdt->ref_tag = cpu_to_be32(phys);

				if (be32_to_cpu(pi->ref_tag) == virt)

					pi->ref_tag = cpu_to_be32(phys);



				virt++;

				phys++;

			}



			kunmap_atomic(sdt);

			kunmap_atomic(pi);

		}



		bip->bip_flags |= BIP_MAPPED_INTEGRITY;
@@ -359,10 +159,10 @@ void sd_dif_prepare(struct request *rq, sector_t hw_sector, 
 */

void sd_dif_complete(struct scsi_cmnd *scmd, unsigned int good_bytes)

{

	const int tuple_sz = sizeof(struct sd_dif_tuple);

	const int tuple_sz = sizeof(struct t10_pi_tuple);

	struct scsi_disk *sdkp;

	struct bio *bio;

	struct sd_dif_tuple *sdt;

	struct t10_pi_tuple *pi;

	unsigned int j, sectors, sector_sz;

	u32 phys, virt;
@@ -386,25 +186,24 @@ void sd_dif_complete(struct scsi_cmnd *scmd, unsigned int good_bytes) 
		virt = bip_get_seed(bip) & 0xffffffff;



		bip_for_each_vec(iv, bip, iter) {

			sdt = kmap_atomic(iv.bv_page)

				+ iv.bv_offset;

			pi = kmap_atomic(iv.bv_page) + iv.bv_offset;



			for (j = 0; j < iv.bv_len; j += tuple_sz, sdt++) {

			for (j = 0; j < iv.bv_len; j += tuple_sz, pi++) {



				if (sectors == 0) {

					kunmap_atomic(sdt);

					kunmap_atomic(pi);

					return;

				}



				if (be32_to_cpu(sdt->ref_tag) == phys)

					sdt->ref_tag = cpu_to_be32(virt);

				if (be32_to_cpu(pi->ref_tag) == phys)

					pi->ref_tag = cpu_to_be32(virt);



				virt++;

				phys++;

				sectors--;

			}



			kunmap_atomic(sdt);

			kunmap_atomic(pi);

		}

	}

}