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Commit 41861fa8 authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

target/sbc: Add DIF TYPE1+TYPE3 read/write verify emulation 



This patch adds support for DIF read/write verify emulation
for TARGET_DIF_TYPE1_PROT + TARGET_DIF_TYPE3_PROT operation.

This includes sbc_dif_verify_write() + sbc_dif_verify_read()
calls accessable by backend drivers to perform DIF verify
for SGL based data and protection information.

Also included is sbc_dif_copy_prot() logic to copy protection
information to/from backend provided protection SGLs.

Based on scsi_debug.c DIF TYPE1+TYPE3 emulation.

v2 changes:
  - Select CRC_T10DIF for TARGET_CORE in Kconfig (Fengguang)
  - Drop IP checksum logic from sbc_dif_v1_verify (MKP)
  - Fix offset on app_tag = 0xffff in sbc_dif_verify_read()

Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 499bf77b

drivers/target/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -3,6 +3,7 @@ menuconfig TARGET_CORE 
	tristate "Generic Target Core Mod (TCM) and ConfigFS Infrastructure"

	depends on SCSI && BLOCK

	select CONFIGFS_FS

	select CRC_T10DIF

	default n

	help

	Say Y or M here to enable the TCM Storage Engine and ConfigFS enabled

drivers/target/target_core_sbc.c

+178 −0
Original line number Diff line number Diff line
@@ -23,6 +23,7 @@ 
#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/ratelimit.h>

#include <linux/crc-t10dif.h>

#include <asm/unaligned.h>

#include <scsi/scsi.h>

#include <scsi/scsi_tcq.h>
@@ -1024,3 +1025,180 @@ sbc_execute_unmap(struct se_cmd *cmd, 
	return ret;

}

EXPORT_SYMBOL(sbc_execute_unmap);



static sense_reason_t

sbc_dif_v1_verify(struct se_device *dev, struct se_dif_v1_tuple *sdt,

		  const void *p, sector_t sector, unsigned int ei_lba)

{

	int block_size = dev->dev_attrib.block_size;

	__be16 csum;



	csum = cpu_to_be16(crc_t10dif(p, block_size));



	if (sdt->guard_tag != csum) {

		pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"

			" csum 0x%04x\n", (unsigned long long)sector,

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

		return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;

	}



	if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE1_PROT &&

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

		pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"

		       " sector MSB: 0x%08x\n", (unsigned long long)sector,

		       be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));

		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;

	}



	if (dev->dev_attrib.pi_prot_type == TARGET_DIF_TYPE2_PROT &&

	    be32_to_cpu(sdt->ref_tag) != ei_lba) {

		pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"

		       " ei_lba: 0x%08x\n", (unsigned long long)sector,

			be32_to_cpu(sdt->ref_tag), ei_lba);

		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;

	}



	return 0;

}



static void

sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,

		  struct scatterlist *sg, int sg_off)

{

	struct se_device *dev = cmd->se_dev;

	struct scatterlist *psg;

	void *paddr, *addr;

	unsigned int i, len, left;



	left = sectors * dev->prot_length;



	for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {



		len = min(psg->length, left);

		paddr = kmap_atomic(sg_page(psg)) + psg->offset;

		addr = kmap_atomic(sg_page(sg)) + sg_off;



		if (read)

			memcpy(paddr, addr, len);

		else

			memcpy(addr, paddr, len);



		left -= len;

		kunmap_atomic(paddr);

		kunmap_atomic(addr);

	}

}



sense_reason_t

sbc_dif_verify_write(struct se_cmd *cmd, sector_t start, unsigned int sectors,

		     unsigned int ei_lba, struct scatterlist *sg, int sg_off)

{

	struct se_device *dev = cmd->se_dev;

	struct se_dif_v1_tuple *sdt;

	struct scatterlist *dsg, *psg = cmd->t_prot_sg;

	sector_t sector = start;

	void *daddr, *paddr;

	int i, j, offset = 0;

	sense_reason_t rc;



	for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {

		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;

		paddr = kmap_atomic(sg_page(psg)) + psg->offset;



		for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {



			if (offset >= psg->length) {

				kunmap_atomic(paddr);

				psg = sg_next(psg);

				paddr = kmap_atomic(sg_page(psg)) + psg->offset;

				offset = 0;

			}



			sdt = paddr + offset;



			pr_debug("DIF WRITE sector: %llu guard_tag: 0x%04x"

				 " app_tag: 0x%04x ref_tag: %u\n",

				 (unsigned long long)sector, sdt->guard_tag,

				 sdt->app_tag, be32_to_cpu(sdt->ref_tag));



			rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,

					       ei_lba);

			if (rc) {

				kunmap_atomic(paddr);

				kunmap_atomic(daddr);

				return rc;

			}



			sector++;

			ei_lba++;

			offset += sizeof(struct se_dif_v1_tuple);

		}



		kunmap_atomic(paddr);

		kunmap_atomic(daddr);

	}

	sbc_dif_copy_prot(cmd, sectors, false, sg, sg_off);



	return 0;

}

EXPORT_SYMBOL(sbc_dif_verify_write);



sense_reason_t

sbc_dif_verify_read(struct se_cmd *cmd, sector_t start, unsigned int sectors,

		    unsigned int ei_lba, struct scatterlist *sg, int sg_off)

{

	struct se_device *dev = cmd->se_dev;

	struct se_dif_v1_tuple *sdt;

	struct scatterlist *dsg;

	sector_t sector = start;

	void *daddr, *paddr;

	int i, j, offset = sg_off;

	sense_reason_t rc;



	for_each_sg(cmd->t_data_sg, dsg, cmd->t_data_nents, i) {

		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;

		paddr = kmap_atomic(sg_page(sg)) + sg->offset;



		for (j = 0; j < dsg->length; j += dev->dev_attrib.block_size) {



			if (offset >= sg->length) {

				kunmap_atomic(paddr);

				sg = sg_next(sg);

				paddr = kmap_atomic(sg_page(sg)) + sg->offset;

				offset = 0;

			}



			sdt = paddr + offset;



			pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"

				 " app_tag: 0x%04x ref_tag: %u\n",

				 (unsigned long long)sector, sdt->guard_tag,

				 sdt->app_tag, be32_to_cpu(sdt->ref_tag));



			if (sdt->app_tag == cpu_to_be16(0xffff)) {

				sector++;

				offset += sizeof(struct se_dif_v1_tuple);

				continue;

			}



			rc = sbc_dif_v1_verify(dev, sdt, daddr + j, sector,

					       ei_lba);

			if (rc) {

				kunmap_atomic(paddr);

				kunmap_atomic(daddr);

				return rc;

			}



			sector++;

			ei_lba++;

			offset += sizeof(struct se_dif_v1_tuple);

		}



		kunmap_atomic(paddr);

		kunmap_atomic(daddr);

	}

	sbc_dif_copy_prot(cmd, sectors, true, sg, sg_off);



	return 0;

}

EXPORT_SYMBOL(sbc_dif_verify_read);

include/target/target_core_backend.h

+4 −0
Original line number Diff line number Diff line
@@ -73,6 +73,10 @@ sense_reason_t sbc_execute_unmap(struct se_cmd *cmd, 
	sense_reason_t (*do_unmap_fn)(struct se_cmd *cmd, void *priv,

				      sector_t lba, sector_t nolb),

	void *priv);

sense_reason_t	sbc_dif_verify_write(struct se_cmd *, sector_t, unsigned int,

				     unsigned int, struct scatterlist *, int);

sense_reason_t	sbc_dif_verify_read(struct se_cmd *, sector_t, unsigned int,

				    unsigned int, struct scatterlist *, int);



void	transport_set_vpd_proto_id(struct t10_vpd *, unsigned char *);

int	transport_set_vpd_assoc(struct t10_vpd *, unsigned char *);