- 根目录:
- drivers
- target
- target_core_sbc.c
/*
* SCSI Block Commands (SBC) parsing and emulation.
*
* (c) Copyright 2002-2013 Datera, Inc.
*
* Nicholas A. Bellinger <nab@kernel.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/ratelimit.h>
#include <linux/crc-t10dif.h>
#include <asm/unaligned.h>
#include <scsi/scsi_proto.h>
#include <scsi/scsi_tcq.h>
#include <target/target_core_base.h>
#include <target/target_core_backend.h>
#include <target/target_core_fabric.h>
#include "target_core_internal.h"
#include "target_core_ua.h"
#include "target_core_alua.h"
static sense_reason_t
sbc_check_prot(struct se_device *, struct se_cmd *, unsigned char *, u32, bool);
static sense_reason_t sbc_execute_unmap(struct se_cmd *cmd);
static sense_reason_t
sbc_emulate_readcapacity(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
unsigned char *cdb = cmd->t_task_cdb;
unsigned long long blocks_long = dev->transport->get_blocks(dev);
unsigned char *rbuf;
unsigned char buf[8];
u32 blocks;
/*
* SBC-2 says:
* If the PMI bit is set to zero and the LOGICAL BLOCK
* ADDRESS field is not set to zero, the device server shall
* terminate the command with CHECK CONDITION status with
* the sense key set to ILLEGAL REQUEST and the additional
* sense code set to INVALID FIELD IN CDB.
*
* In SBC-3, these fields are obsolete, but some SCSI
* compliance tests actually check this, so we might as well
* follow SBC-2.
*/
if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
return TCM_INVALID_CDB_FIELD;
if (blocks_long >= 0x00000000ffffffff)
blocks = 0xffffffff;
else
blocks = (u32)blocks_long;
buf[0] = (blocks >> 24) & 0xff;
buf[1] = (blocks >> 16) & 0xff;
buf[2] = (blocks >> 8) & 0xff;
buf[3] = blocks & 0xff;
buf[4] = (dev->dev_attrib.block_size >> 24) & 0xff;
buf[5] = (dev->dev_attrib.block_size >> 16) & 0xff;
buf[6] = (dev->dev_attrib.block_size >> 8) & 0xff;
buf[7] = dev->dev_attrib.block_size & 0xff;
rbuf = transport_kmap_data_sg(cmd);
if (rbuf) {
memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
transport_kunmap_data_sg(cmd);
}
target_complete_cmd_with_length(cmd, GOOD, 8);
return 0;
}
static sense_reason_t
sbc_emulate_readcapacity_16(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
struct se_session *sess = cmd->se_sess;
int pi_prot_type = dev->dev_attrib.pi_prot_type;
unsigned char *rbuf;
unsigned char buf[32];
unsigned long long blocks = dev->transport->get_blocks(dev);
memset(buf, 0, sizeof(buf));
buf[0] = (blocks >> 56) & 0xff;
buf[1] = (blocks >> 48) & 0xff;
buf[2] = (blocks >> 40) & 0xff;
buf[3] = (blocks >> 32) & 0xff;
buf[4] = (blocks >> 24) & 0xff;
buf[5] = (blocks >> 16) & 0xff;
buf[6] = (blocks >> 8) & 0xff;
buf[7] = blocks & 0xff;
buf[8] = (dev->dev_attrib.block_size >> 24) & 0xff;
buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;
buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;
buf[11] = dev->dev_attrib.block_size & 0xff;
/*
* Set P_TYPE and PROT_EN bits for DIF support
*/
if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
/*
* Only override a device's pi_prot_type if no T10-PI is
* available, and sess_prot_type has been explicitly enabled.
*/
if (!pi_prot_type)
pi_prot_type = sess->sess_prot_type;
if (pi_prot_type)
buf[12] = (pi_prot_type - 1) << 1 | 0x1;
}
if (dev->transport->get_lbppbe)
buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
if (dev->transport->get_alignment_offset_lbas) {
u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
buf[14] = (lalba >> 8) & 0x3f;
buf[15] = lalba & 0xff;
}
/*
* Set Thin Provisioning Enable bit following sbc3r22 in section
* READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
*/
if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws)
buf[14] |= 0x80;
rbuf = transport_kmap_data_sg(cmd);
if (rbuf) {
memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
transport_kunmap_data_sg(cmd);
}
target_complete_cmd_with_length(cmd, GOOD, 32);
return 0;
}
static sense_reason_t
sbc_emulate_startstop(struct se_cmd *cmd)
{
unsigned char *cdb = cmd->t_task_cdb;
/*
* See sbc3r36 section 5.25
* Immediate bit should be set since there is nothing to complete
* POWER CONDITION MODIFIER 0h
*/
if (!(cdb[1] & 1) || cdb[2] || cdb[3])
return TCM_INVALID_CDB_FIELD;
/*
* See sbc3r36 section 5.25
* POWER CONDITION 0h START_VALID - process START and LOEJ
*/
if (cdb[4] >> 4 & 0xf)
return TCM_INVALID_CDB_FIELD;
/*
* See sbc3r36 section 5.25
* LOEJ 0h - nothing to load or unload
* START 1h - we are ready
*/
if (!(cdb[4] & 1) || (cdb[4] & 2) || (cdb[4] & 4))
return TCM_INVALID_CDB_FIELD;
target_complete_cmd(cmd, SAM_STAT_GOOD);
return 0;
}
sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
{
u32 num_blocks;
if (cmd->t_task_cdb[0] == WRITE_SAME)
num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
/*
* Use the explicit range when non zero is supplied, otherwise calculate
* the remaining range based on ->get_blocks() - starting LBA.
*/
if (num_blocks)
return num_blocks;
return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
cmd->t_task_lba + 1;
}
EXPORT_SYMBOL(sbc_get_write_same_sectors);
static sense_reason_t
sbc_execute_write_same_unmap(struct se_cmd *cmd)
{
struct sbc_ops *ops = cmd->protocol_data;
sector_t nolb = sbc_get_write_same_sectors(cmd);
sense_reason_t ret;
if (nolb) {
ret = ops->execute_unmap(cmd, cmd->t_task_lba, nolb);
if (ret)
return ret;
}
target_complete_cmd(cmd, GOOD);
return 0;
}
static sense_reason_t
sbc_emulate_noop(struct se_cmd *cmd)
{
target_complete_cmd(cmd, GOOD);
return 0;
}
static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
{
return cmd->se_dev->dev_attrib.block_size * sectors;
}
static inline u32 transport_get_sectors_6(unsigned char *cdb)
{
/*
* Use 8-bit sector value. SBC-3 says:
*
* A TRANSFER LENGTH field set to zero specifies that 256
* logical blocks shall be written. Any other value
* specifies the number of logical blocks that shall be
* written.
*/
return cdb[4] ? : 256;
}
static inline u32 transport_get_sectors_10(unsigned char *cdb)
{
return (u32)(cdb[7] << 8) + cdb[8];
}
static inline u32 transport_get_sectors_12(unsigned char *cdb)
{
return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
}
static inline u32 transport_get_sectors_16(unsigned char *cdb)
{
return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
(cdb[12] << 8) + cdb[13];
}
/*
* Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
*/
static inline u32 transport_get_sectors_32(unsigned char *cdb)
{
return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
(cdb[30] << 8) + cdb[31];
}
static inline u32 transport_lba_21(unsigned char *cdb)
{
return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
}
static inline u32 transport_lba_32(unsigned char *cdb)
{
return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
}
static inline unsigned long long transport_lba_64(unsigned char *cdb)
{
unsigned int __v1, __v2;
__v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
__v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
}
/*
* For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
*/
static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
{
unsigned int __v1, __v2;
__v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
__v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];
return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
}
static sense_reason_t
sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
{
struct se_device *dev = cmd->se_dev;
sector_t end_lba = dev->transport->get_blocks(dev) + 1;
unsigned int sectors = sbc_get_write_same_sectors(cmd);
sense_reason_t ret;
if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
pr_err("WRITE_SAME PBDATA and LBDATA"
" bits not supported for Block Discard"
" Emulation\n");
return TCM_UNSUPPORTED_SCSI_OPCODE;
}
if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
sectors, cmd->se_dev->dev_attrib.max_write_same_len);
return TCM_INVALID_CDB_FIELD;
}
/*
* Sanity check for LBA wrap and request past end of device.
*/
if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
((cmd->t_task_lba + sectors) > end_lba)) {
pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
(unsigned long long)end_lba, cmd->t_task_lba, sectors);
return TCM_ADDRESS_OUT_OF_RANGE;
}
/* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
if (flags[0] & 0x10) {
pr_warn("WRITE SAME with ANCHOR not supported\n");
return TCM_INVALID_CDB_FIELD;
}
/*
* Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
* translated into block discard requests within backend code.
*/
if (flags[0] & 0x08) {
if (!ops->execute_unmap)
return TCM_UNSUPPORTED_SCSI_OPCODE;
if (!dev->dev_attrib.emulate_tpws) {
pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
" has emulate_tpws disabled\n");
return TCM_UNSUPPORTED_SCSI_OPCODE;
}
cmd->execute_cmd = sbc_execute_write_same_unmap;
return 0;
}
if (!ops->execute_write_same)
return TCM_UNSUPPORTED_SCSI_OPCODE;
ret = sbc_check_prot(dev, cmd, &cmd->t_task_cdb[0], sectors, true);
if (ret)
return ret;
cmd->execute_cmd = ops->execute_write_same;
return 0;
}
static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd, bool success,
int *post_ret)
{
unsigned char *buf, *addr;
struct scatterlist *sg;
unsigned int offset;
sense_reason_t ret = TCM_NO_SENSE;
int i, count;
/*
* From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
*
* 1) read the specified logical block(s);
* 2) transfer logical blocks from the data-out buffer;
* 3) XOR the logical blocks transferred from the data-out buffer with
* the logical blocks read, storing the resulting XOR data in a buffer;
* 4) if the DISABLE WRITE bit is set to zero, then write the logical
* blocks transferred from the data-out buffer; and
* 5) transfer the resulting XOR data to the data-in buffer.
*/
buf = kmalloc(cmd->data_length, GFP_KERNEL);
if (!buf) {
pr_err("Unable to allocate xor_callback buf\n");
return TCM_OUT_OF_RESOURCES;
}
/*
* Copy the scatterlist WRITE buffer located at cmd->t_data_sg
* into the locally allocated *buf
*/
sg_copy_to_buffer(cmd->t_data_sg,
cmd->t_data_nents,
buf,
cmd->data_length);
/*
* Now perform the XOR against the BIDI read memory located at
* cmd->t_mem_bidi_list
*/
offset = 0;
for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
addr = kmap_atomic(sg_page(sg));
if (!addr) {
ret = TCM_OUT_OF_RESOURCES;
goto out;
}
for (i = 0; i < sg->length; i++)
*(addr + sg->offset + i) ^= *(buf + offset + i);
offset += sg->length;
kunmap_atomic(addr);
}
out:
kfree(buf);
return ret;
}
static sense_reason_t
sbc_execute_rw(struct se_cmd *cmd)
{
struct sbc_ops *ops = cmd->protocol_data;
return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
cmd->data_direction);
}
static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success,
int *post_ret)
{
struct se_device *dev = cmd->se_dev;
/*
* Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through
* within target_complete_ok_work() if the command was successfully
* sent to the backend driver.
*/
spin_lock_irq(&cmd->t_state_lock);
if ((cmd->transport_state & CMD_T_SENT) && !cmd->scsi_status) {
cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
*post_ret = 1;
}
spin_unlock_irq(&cmd->t_state_lock);
/*
* Unlock ->caw_sem originally obtained during sbc_compare_and_write()
* before the original READ I/O submission.
*/
up(&dev->caw_sem);
return TCM_NO_SENSE;
}
static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success,
int *post_ret)
{
struct se_device *dev = cmd->se_dev;
struct scatterlist *write_sg = NULL, *sg;
unsigned char *buf = NULL, *addr;
struct sg_mapping_iter m;
unsigned int offset = 0, len;
unsigned int nlbas = cmd->t_task_nolb;
unsigned int block_size = dev->dev_attrib.block_size;
unsigned int compare_len = (nlbas * block_size);
sense_reason_t ret = TCM_NO_SENSE;
int rc, i;
/*
* Handle early failure in transport_generic_request_failure(),
* which will not have taken ->caw_sem yet..
*/
if (!success && (!cmd->t_data_sg || !cmd->t_bidi_data_sg))
return TCM_NO_SENSE;
/*
* Handle special case for zero-length COMPARE_AND_WRITE
*/
if (!cmd->data_length)
goto out;
/*
* Immediately exit + release dev->caw_sem if command has already
* been failed with a non-zero SCSI status.
*/
if (cmd->scsi_status) {
pr_err("compare_and_write_callback: non zero scsi_status:"
" 0x%02x\n", cmd->scsi_status);
goto out;
}
buf = kzalloc(cmd->data_length, GFP_KERNEL);
if (!buf) {
pr_err("Unable to allocate compare_and_write buf\n");
ret = TCM_OUT_OF_RESOURCES;
goto out;
}
write_sg = kmalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
GFP_KERNEL);
if (!write_sg) {
pr_err("Unable to allocate compare_and_write sg\n");
ret = TCM_OUT_OF_RESOURCES;
goto out;
}
sg_init_table(write_sg, cmd->t_data_nents);
/*
* Setup verify and write data payloads from total NumberLBAs.
*/
rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
cmd->data_length);
if (!rc) {
pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
ret = TCM_OUT_OF_RESOURCES;
goto out;
}
/*
* Compare against SCSI READ payload against verify payload
*/
for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
addr = (unsigned char *)kmap_atomic(sg_page(sg));
if (!addr) {
ret = TCM_OUT_OF_RESOURCES;
goto out;
}
len = min(sg->length, compare_len);
if (memcmp(addr, buf + offset, len)) {
pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
addr, buf + offset);
kunmap_atomic(addr);
goto miscompare;
}
kunmap_atomic(addr);
offset += len;
compare_len -= len;
if (!compare_len)
break;
}
i = 0;
len = cmd->t_task_nolb * block_size;
sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
/*
* Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
*/
while (len) {
sg_miter_next(&m);
if (block_size < PAGE_SIZE) {
sg_set_page(&write_sg[i], m.page, block_size,
m.piter.sg->offset + block_size);
} else {
sg_miter_next(&m);
sg_set_page(&write_sg[i], m.page, block_size,
m.piter.sg->offset);
}
len -= block_size;
i++;
}
sg_miter_stop(&m);
/*
* Save the original SGL + nents values before updating to new
* assignments, to be released in transport_free_pages() ->
* transport_reset_sgl_orig()
*/
cmd->t_data_sg_orig = cmd->t_data_sg;
cmd->t_data_sg = write_sg;
cmd->t_data_nents_orig = cmd->t_data_nents;
cmd->t_data_nents = 1;
cmd->sam_task_attr = TCM_HEAD_TAG;
cmd->transport_complete_callback = compare_and_write_post;
/*
* Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
* for submitting the adjusted SGL to write instance user-data.
*/
cmd->execute_cmd = sbc_execute_rw;
spin_lock_irq(&cmd->t_state_lock);
cmd->t_state = TRANSPORT_PROCESSING;
cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
spin_unlock_irq(&cmd->t_state_lock);
__target_execute_cmd(cmd);
kfree(buf);
return ret;
miscompare:
pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
dev->transport->name);
ret = TCM_MISCOMPARE_VERIFY;
out:
/*
* In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
* sbc_compare_and_write() before the original READ I/O submission.
*/
up(&dev->caw_sem);
kfree(write_sg);
kfree(buf);
return ret;
}
static sense_reason_t
sbc_compare_and_write(struct se_cmd *cmd)
{
struct sbc_ops *ops = cmd->protocol_data;
struct se_device *dev = cmd->se_dev;
sense_reason_t ret;
int rc;
/*
* Submit the READ first for COMPARE_AND_WRITE to perform the
* comparision using SGLs at cmd->t_bidi_data_sg..
*/
rc = down_interruptible(&dev->caw_sem);
if (rc != 0) {
cmd->transport_complete_callback = NULL;
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
}
/*
* Reset cmd->data_length to individual block_size in order to not
* confuse backend drivers that depend on this value matching the
* size of the I/O being submitted.
*/
cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
DMA_FROM_DEVICE);
if (ret) {
cmd->transport_complete_callback = NULL;
up(&dev->caw_sem);
return ret;
}
/*
* Unlock of dev->caw_sem to occur in compare_and_write_callback()
* upon MISCOMPARE, or in compare_and_write_done() upon completion
* of WRITE instance user-data.
*/
return TCM_NO_SENSE;
}
static int
sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
bool is_write, struct se_cmd *cmd)
{
if (is_write) {
cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
protect ? TARGET_PROT_DOUT_PASS :
TARGET_PROT_DOUT_INSERT;
switch (protect) {
case 0x0:
case 0x3:
cmd->prot_checks = 0;
break;
case 0x1:
case 0x5:
cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
if (prot_type == TARGET_DIF_TYPE1_PROT)
cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
break;
case 0x2:
if (prot_type == TARGET_DIF_TYPE1_PROT)
cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
break;
case 0x4:
cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
break;
default:
pr_err("Unsupported protect field %d\n", protect);
return -EINVAL;
}
} else {
cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
protect ? TARGET_PROT_DIN_PASS :
TARGET_PROT_DIN_STRIP;
switch (protect) {
case 0x0:
case 0x1:
case 0x5:
cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
if (prot_type == TARGET_DIF_TYPE1_PROT)
cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
break;
case 0x2:
if (prot_type == TARGET_DIF_TYPE1_PROT)
cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
break;
case 0x3:
cmd->prot_checks = 0;
break;
case 0x4:
cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
break;
default:
pr_err("Unsupported protect field %d\n", protect);
return -EINVAL;
}
}
return 0;
}
static sense_reason_t
sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
u32 sectors, bool is_write)
{
u8 protect = cdb[1] >> 5;
int sp_ops = cmd->se_sess->sup_prot_ops;
int pi_prot_type = dev->dev_attrib.pi_prot_type;
bool fabric_prot = false;
if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
if (unlikely(protect &&
!dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
pr_err("CDB contains protect bit, but device + fabric does"
" not advertise PROTECT=1 feature bit\n");
return TCM_INVALID_CDB_FIELD;
}
if (cmd->prot_pto)
return TCM_NO_SENSE;
}
switch (dev->dev_attrib.pi_prot_type) {
case TARGET_DIF_TYPE3_PROT:
cmd->reftag_seed = 0xffffffff;
break;
case TARGET_DIF_TYPE2_PROT:
if (protect)
return TCM_INVALID_CDB_FIELD;
cmd->reftag_seed = cmd->t_task_lba;
break;
case TARGET_DIF_TYPE1_PROT:
cmd->reftag_seed = cmd->t_task_lba;
break;
case TARGET_DIF_TYPE0_PROT:
/*
* See if the fabric supports T10-PI, and the session has been
* configured to allow export PROTECT=1 feature bit with backend
* devices that don't support T10-PI.
*/
fabric_prot = is_write ?
!!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
!!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
if (fabric_prot && cmd->se_sess->sess_prot_type) {
pi_prot_type = cmd->se_sess->sess_prot_type;
break;
}
if (!protect)
return TCM_NO_SENSE;
/* Fallthrough */
default:
pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
"PROTECT: 0x%02x\n", cdb[0], protect);
return TCM_INVALID_CDB_FIELD;
}
if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
return TCM_INVALID_CDB_FIELD;
cmd->prot_type = pi_prot_type;
cmd->prot_length = dev->prot_length * sectors;
/**
* In case protection information exists over the wire
* we modify command data length to describe pure data.
* The actual transfer length is data length + protection
* length
**/
if (protect)
cmd->data_length = sectors * dev->dev_attrib.block_size;
pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
"prot_op=%d prot_checks=%d\n",
__func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
cmd->prot_op, cmd->prot_checks);
return TCM_NO_SENSE;
}
static int
sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
{
if (cdb[1] & 0x10) {
/* see explanation in spc_emulate_modesense */
if (!target_check_fua(dev)) {
pr_err("Got CDB: 0x%02x with DPO bit set, but device"
" does not advertise support for DPO\n", cdb[0]);
return -EINVAL;
}
}
if (cdb[1] & 0x8) {
if (!target_check_fua(dev)) {
pr_err("Got CDB: 0x%02x with FUA bit set, but device"
" does not advertise support for FUA write\n",
cdb[0]);
return -EINVAL;
}
cmd->se_cmd_flags |= SCF_FUA;
}
return 0;
}
sense_reason_t
sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
{
struct se_device *dev = cmd->se_dev;
unsigned char *cdb = cmd->t_task_cdb;
unsigned int size;
u32 sectors = 0;
sense_reason_t ret;
cmd->protocol_data = ops;
switch (cdb[0]) {
case READ_6:
sectors = transport_get_sectors_6(cdb);
cmd->t_task_lba = transport_lba_21(cdb);
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
cmd->execute_cmd = sbc_execute_rw;
break;
case READ_10:
sectors = transport_get_sectors_10(cdb);
cmd->t_task_lba = transport_lba_32(cdb);
if (sbc_check_dpofua(dev, cmd, cdb))
return TCM_INVALID_CDB_FIELD;
ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
if (ret)
return ret;
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
cmd->execute_cmd = sbc_execute_rw;
break;
case READ_12:
sectors = transport_get_sectors_12(cdb);
cmd->t_task_lba = transport_lba_32(cdb);
if (sbc_check_dpofua(dev, cmd, cdb))
return TCM_INVALID_CDB_FIELD;
ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
if (ret)
return ret;
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
cmd->execute_cmd = sbc_execute_rw;
break;
case READ_16:
sectors = transport_get_sectors_16(cdb);
cmd->t_task_lba = transport_lba_64(cdb);
if (sbc_check_dpofua(dev, cmd, cdb))
return TCM_INVALID_CDB_FIELD;
ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
if (ret)
return ret;
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
cmd->execute_cmd = sbc_execute_rw;
break;
case WRITE_6:
sectors = transport_get_sectors_6(cdb);
cmd->t_task_lba = transport_lba_21(cdb);
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
cmd->execute_cmd = sbc_execute_rw;
break;
case WRITE_10:
case WRITE_VERIFY:
sectors = transport_get_sectors_10(cdb);
cmd->t_task_lba = transport_lba_32(cdb);
if (sbc_check_dpofua(dev, cmd, cdb))
return TCM_INVALID_CDB_FIELD;
ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
if (ret)
return ret;
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
cmd->execute_cmd = sbc_execute_rw;
break;
case WRITE_12:
sectors = transport_get_sectors_12(cdb);
cmd->t_task_lba = transport_lba_32(cdb);
if (sbc_check_dpofua(dev, cmd, cdb))
return TCM_INVALID_CDB_FIELD;
ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
if (ret)
return ret;
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
cmd->execute_cmd = sbc_execute_rw;
break;
case WRITE_16:
sectors = transport_get_sectors_16(cdb);
cmd->t_task_lba = transport_lba_64(cdb);
if (sbc_check_dpofua(dev, cmd, cdb))
return TCM_INVALID_CDB_FIELD;
ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
if (ret)
return ret;
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
cmd->execute_cmd = sbc_execute_rw;
break;
case XDWRITEREAD_10:
if (cmd->data_direction != DMA_TO_DEVICE ||
!(cmd->se_cmd_flags & SCF_BIDI))
return TCM_INVALID_CDB_FIELD;
sectors = transport_get_sectors_10(cdb);
if (sbc_check_dpofua(dev, cmd, cdb))
return TCM_INVALID_CDB_FIELD;
cmd->t_task_lba = transport_lba_32(cdb);
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
/*
* Setup BIDI XOR callback to be run after I/O completion.
*/
cmd->execute_cmd = sbc_execute_rw;
cmd->transport_complete_callback = &xdreadwrite_callback;
break;
case VARIABLE_LENGTH_CMD:
{
u16 service_action = get_unaligned_be16(&cdb[8]);
switch (service_action) {
case XDWRITEREAD_32:
sectors = transport_get_sectors_32(cdb);
if (sbc_check_dpofua(dev, cmd, cdb))
return TCM_INVALID_CDB_FIELD;
/*
* Use WRITE_32 and READ_32 opcodes for the emulated
* XDWRITE_READ_32 logic.
*/
cmd->t_task_lba = transport_lba_64_ext(cdb);
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
/*
* Setup BIDI XOR callback to be run during after I/O
* completion.
*/
cmd->execute_cmd = sbc_execute_rw;
cmd->transport_complete_callback = &xdreadwrite_callback;
break;
case WRITE_SAME_32:
sectors = transport_get_sectors_32(cdb);
if (!sectors) {
pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
" supported\n");
return TCM_INVALID_CDB_FIELD;
}
size = sbc_get_size(cmd, 1);
cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
ret = sbc_setup_write_same(cmd, &cdb[10], ops);
if (ret)
return ret;
break;
default:
pr_err("VARIABLE_LENGTH_CMD service action"
" 0x%04x not supported\n", service_action);
return TCM_UNSUPPORTED_SCSI_OPCODE;
}
break;
}
case COMPARE_AND_WRITE:
sectors = cdb[13];
/*
* Currently enforce COMPARE_AND_WRITE for a single sector
*/
if (sectors > 1) {
pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
" than 1\n", sectors);
return TCM_INVALID_CDB_FIELD;
}
if (sbc_check_dpofua(dev, cmd, cdb))
return TCM_INVALID_CDB_FIELD;
/*
* Double size because we have two buffers, note that
* zero is not an error..
*/
size = 2 * sbc_get_size(cmd, sectors);
cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
cmd->t_task_nolb = sectors;
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
cmd->execute_cmd = sbc_compare_and_write;
cmd->transport_complete_callback = compare_and_write_callback;
break;
case READ_CAPACITY:
size = READ_CAP_LEN;
cmd->execute_cmd = sbc_emulate_readcapacity;
break;
case SERVICE_ACTION_IN_16:
switch (cmd->t_task_cdb[1] & 0x1f) {
case SAI_READ_CAPACITY_16:
cmd->execute_cmd = sbc_emulate_readcapacity_16;
break;
case SAI_REPORT_REFERRALS:
cmd->execute_cmd = target_emulate_report_referrals;
break;
default:
pr_err("Unsupported SA: 0x%02x\n",
cmd->t_task_cdb[1] & 0x1f);
return TCM_INVALID_CDB_FIELD;
}
size = (cdb[10] << 24) | (cdb[11] << 16) |
(cdb[12] << 8) | cdb[13];
break;
case SYNCHRONIZE_CACHE:
case SYNCHRONIZE_CACHE_16:
if (cdb[0] == SYNCHRONIZE_CACHE) {
sectors = transport_get_sectors_10(cdb);
cmd->t_task_lba = transport_lba_32(cdb);
} else {
sectors = transport_get_sectors_16(cdb);
cmd->t_task_lba = transport_lba_64(cdb);
}
if (ops->execute_sync_cache) {
cmd->execute_cmd = ops->execute_sync_cache;
goto check_lba;
}
size = 0;
cmd->execute_cmd = sbc_emulate_noop;
break;
case UNMAP:
if (!ops->execute_unmap)
return TCM_UNSUPPORTED_SCSI_OPCODE;
if (!dev->dev_attrib.emulate_tpu) {
pr_err("Got UNMAP, but backend device has"
" emulate_tpu disabled\n");
return TCM_UNSUPPORTED_SCSI_OPCODE;
}
size = get_unaligned_be16(&cdb[7]);
cmd->execute_cmd = sbc_execute_unmap;
break;
case WRITE_SAME_16:
sectors = transport_get_sectors_16(cdb);
if (!sectors) {
pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
return TCM_INVALID_CDB_FIELD;
}
size = sbc_get_size(cmd, 1);
cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
ret = sbc_setup_write_same(cmd, &cdb[1], ops);
if (ret)
return ret;
break;
case WRITE_SAME:
sectors = transport_get_sectors_10(cdb);
if (!sectors) {
pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
return TCM_INVALID_CDB_FIELD;
}
size = sbc_get_size(cmd, 1);
cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
/*
* Follow sbcr26 with WRITE_SAME (10) and check for the existence
* of byte 1 bit 3 UNMAP instead of original reserved field
*/
ret = sbc_setup_write_same(cmd, &cdb[1], ops);
if (ret)
return ret;
break;
case VERIFY:
size = 0;
sectors = transport_get_sectors_10(cdb);
cmd->t_task_lba = transport_lba_32(cdb);
cmd->execute_cmd = sbc_emulate_noop;
goto check_lba;
case REZERO_UNIT:
case SEEK_6:
case SEEK_10:
/*
* There are still clients out there which use these old SCSI-2
* commands. This mainly happens when running VMs with legacy
* guest systems, connected via SCSI command pass-through to
* iSCSI targets. Make them happy and return status GOOD.
*/
size = 0;
cmd->execute_cmd = sbc_emulate_noop;
break;
case START_STOP:
size = 0;
cmd->execute_cmd = sbc_emulate_startstop;
break;
default:
ret = spc_parse_cdb(cmd, &size);
if (ret)
return ret;
}
/* reject any command that we don't have a handler for */
if (!cmd->execute_cmd)
return TCM_UNSUPPORTED_SCSI_OPCODE;
if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
unsigned long long end_lba;
check_lba:
end_lba = dev->transport->get_blocks(dev) + 1;
if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
((cmd->t_task_lba + sectors) > end_lba)) {
pr_err("cmd exceeds last lba %llu "
"(lba %llu, sectors %u)\n",
end_lba, cmd->t_task_lba, sectors);
return TCM_ADDRESS_OUT_OF_RANGE;
}
if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
size = sbc_get_size(cmd, sectors);
}
return target_cmd_size_check(cmd, size);
}
EXPORT_SYMBOL(sbc_parse_cdb);
u32 sbc_get_device_type(struct se_device *dev)
{
return TYPE_DISK;
}
EXPORT_SYMBOL(sbc_get_device_type);
static sense_reason_t
sbc_execute_unmap(struct se_cmd *cmd)
{
struct sbc_ops *ops = cmd->protocol_data;
struct se_device *dev = cmd->se_dev;
unsigned char *buf, *ptr = NULL;
sector_t lba;
int size;
u32 range;
sense_reason_t ret = 0;
int dl, bd_dl;
/* We never set ANC_SUP */
if (cmd->t_task_cdb[1])
return TCM_INVALID_CDB_FIELD;
if (cmd->data_length == 0) {
target_complete_cmd(cmd, SAM_STAT_GOOD);
return 0;
}
if (cmd->data_length < 8) {
pr_warn("UNMAP parameter list length %u too small\n",
cmd->data_length);
return TCM_PARAMETER_LIST_LENGTH_ERROR;
}
buf = transport_kmap_data_sg(cmd);
if (!buf)
return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
dl = get_unaligned_be16(&buf[0]);
bd_dl = get_unaligned_be16(&buf[2]);
size = cmd->data_length - 8;
if (bd_dl > size)
pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
cmd->data_length, bd_dl);
else
size = bd_dl;
if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
ret = TCM_INVALID_PARAMETER_LIST;
goto err;
}
/* First UNMAP block descriptor starts at 8 byte offset */
ptr = &buf[8];
pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
" ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
while (size >= 16) {
lba = get_unaligned_be64(&ptr[0]);
range = get_unaligned_be32(&ptr[8]);
pr_debug("UNMAP: Using lba: %llu and range: %u\n",
(unsigned long long)lba, range);
if (range > dev->dev_attrib.max_unmap_lba_count) {
ret = TCM_INVALID_PARAMETER_LIST;
goto err;
}
if (lba + range > dev->transport->get_blocks(dev) + 1) {
ret = TCM_ADDRESS_OUT_OF_RANGE;
goto err;
}
ret = ops->execute_unmap(cmd, lba, range);
if (ret)
goto err;
ptr += 16;
size -= 16;
}
err:
transport_kunmap_data_sg(cmd);
if (!ret)
target_complete_cmd(cmd, GOOD);
return ret;
}
void
sbc_dif_generate(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
struct t10_pi_tuple *sdt;
struct scatterlist *dsg = cmd->t_data_sg, *psg;
sector_t sector = cmd->t_task_lba;
void *daddr, *paddr;
int i, j, offset = 0;
unsigned int block_size = dev->dev_attrib.block_size;
for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
paddr = kmap_atomic(sg_page(psg)) + psg->offset;
daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
for (j = 0; j < psg->length;
j += sizeof(*sdt)) {
__u16 crc;
unsigned int avail;
if (offset >= dsg->length) {
offset -= dsg->length;
kunmap_atomic(daddr - dsg->offset);
dsg = sg_next(dsg);
if (!dsg) {
kunmap_atomic(paddr - psg->offset);
return;
}
daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
}
sdt = paddr + j;
avail = min(block_size, dsg->length - offset);
crc = crc_t10dif(daddr + offset, avail);
if (avail < block_size) {
kunmap_atomic(daddr - dsg->offset);
dsg = sg_next(dsg);
if (!dsg) {
kunmap_atomic(paddr - psg->offset);
return;
}
daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
offset = block_size - avail;
crc = crc_t10dif_update(crc, daddr, offset);
} else {
offset += block_size;
}
sdt->guard_tag = cpu_to_be16(crc);
if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
sdt->app_tag = 0;
pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
" app_tag: 0x%04x ref_tag: %u\n",
(cmd->data_direction == DMA_TO_DEVICE) ?
"WRITE" : "READ", (unsigned long long)sector,
sdt->guard_tag, sdt->app_tag,
be32_to_cpu(sdt->ref_tag));
sector++;
}
kunmap_atomic(daddr - dsg->offset);
kunmap_atomic(paddr - psg->offset);
}
}
static sense_reason_t
sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
__u16 crc, sector_t sector, unsigned int ei_lba)
{
__be16 csum;
if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
goto check_ref;
csum = cpu_to_be16(crc);
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;
}
check_ref:
if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
return 0;
if (cmd->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 (cmd->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;
}
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;
unsigned int offset = sg_off;
if (!sg)
return;
left = sectors * dev->prot_length;
for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
unsigned int psg_len, copied = 0;
paddr = kmap_atomic(sg_page(psg)) + psg->offset;
psg_len = min(left, psg->length);
while (psg_len) {
len = min(psg_len, sg->length - offset);
addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
if (read)
memcpy(paddr + copied, addr, len);
else
memcpy(addr, paddr + copied, len);
left -= len;
offset += len;
copied += len;
psg_len -= len;
kunmap_atomic(addr - sg->offset - offset);
if (offset >= sg->length) {
sg = sg_next(sg);
offset = 0;
}
}
kunmap_atomic(paddr - psg->offset);
}
}
EXPORT_SYMBOL(sbc_dif_copy_prot);
sense_reason_t
sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
unsigned int ei_lba, struct scatterlist *psg, int psg_off)
{
struct se_device *dev = cmd->se_dev;
struct t10_pi_tuple *sdt;
struct scatterlist *dsg = cmd->t_data_sg;
sector_t sector = start;
void *daddr, *paddr;
int i;
sense_reason_t rc;
int dsg_off = 0;
unsigned int block_size = dev->dev_attrib.block_size;
for (; psg && sector < start + sectors; psg = sg_next(psg)) {
paddr = kmap_atomic(sg_page(psg)) + psg->offset;
daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
for (i = psg_off; i < psg->length &&
sector < start + sectors;
i += sizeof(*sdt)) {
__u16 crc;
unsigned int avail;
if (dsg_off >= dsg->length) {
dsg_off -= dsg->length;
kunmap_atomic(daddr - dsg->offset);
dsg = sg_next(dsg);
if (!dsg) {
kunmap_atomic(paddr - psg->offset);
return 0;
}
daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
}
sdt = paddr + i;
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)) {
dsg_off += block_size;
goto next;
}
avail = min(block_size, dsg->length - dsg_off);
crc = crc_t10dif(daddr + dsg_off, avail);
if (avail < block_size) {
kunmap_atomic(daddr - dsg->offset);
dsg = sg_next(dsg);
if (!dsg) {
kunmap_atomic(paddr - psg->offset);
return 0;
}
daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
dsg_off = block_size - avail;
crc = crc_t10dif_update(crc, daddr, dsg_off);
} else {
dsg_off += block_size;
}
rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
if (rc) {
kunmap_atomic(daddr - dsg->offset);
kunmap_atomic(paddr - psg->offset);
cmd->bad_sector = sector;
return rc;
}
next:
sector++;
ei_lba++;
}
psg_off = 0;
kunmap_atomic(daddr - dsg->offset);
kunmap_atomic(paddr - psg->offset);
}
return 0;
}
EXPORT_SYMBOL(sbc_dif_verify);