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linux/drivers/target/target_core_sbc.c
Christoph Hellwig 14150a6bbe target: move unmap to struct spc_ops 
Having all the unmap payload parsing in the backed is a bit ugly, but until
more drivers support it and we can find a good interface for all of them
that seems the way to go.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
2012-07-16 17:35:14 -07:00

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/*
* SCSI Block Commands (SBC) parsing and emulation.
*
* Copyright (c) 2002, 2003, 2004, 2005 PyX Technologies, Inc.
* Copyright (c) 2005, 2006, 2007 SBE, Inc.
* Copyright (c) 2007-2010 Rising Tide Systems
* Copyright (c) 2008-2010 Linux-iSCSI.org
*
* 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 <asm/unaligned.h>
#include <scsi/scsi.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"
static int sbc_emulate_readcapacity(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
unsigned char *buf;
unsigned long long blocks_long = dev->transport->get_blocks(dev);
u32 blocks;
if (blocks_long >= 0x00000000ffffffff)
blocks = 0xffffffff;
else
blocks = (u32)blocks_long;
buf = transport_kmap_data_sg(cmd);
buf[0] = (blocks >> 24) & 0xff;
buf[1] = (blocks >> 16) & 0xff;
buf[2] = (blocks >> 8) & 0xff;
buf[3] = blocks & 0xff;
buf[4] = (dev->se_sub_dev->se_dev_attrib.block_size >> 24) & 0xff;
buf[5] = (dev->se_sub_dev->se_dev_attrib.block_size >> 16) & 0xff;
buf[6] = (dev->se_sub_dev->se_dev_attrib.block_size >> 8) & 0xff;
buf[7] = dev->se_sub_dev->se_dev_attrib.block_size & 0xff;
transport_kunmap_data_sg(cmd);
target_complete_cmd(cmd, GOOD);
return 0;
}
static int sbc_emulate_readcapacity_16(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
unsigned char *buf;
unsigned long long blocks = dev->transport->get_blocks(dev);
buf = transport_kmap_data_sg(cmd);
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->se_sub_dev->se_dev_attrib.block_size >> 24) & 0xff;
buf[9] = (dev->se_sub_dev->se_dev_attrib.block_size >> 16) & 0xff;
buf[10] = (dev->se_sub_dev->se_dev_attrib.block_size >> 8) & 0xff;
buf[11] = dev->se_sub_dev->se_dev_attrib.block_size & 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->se_sub_dev->se_dev_attrib.emulate_tpu || dev->se_sub_dev->se_dev_attrib.emulate_tpws)
buf[14] = 0x80;
transport_kunmap_data_sg(cmd);
target_complete_cmd(cmd, GOOD);
return 0;
}
int spc_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(spc_get_write_same_sectors);
static int sbc_emulate_verify(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->se_sub_dev->se_dev_attrib.block_size * sectors;
}
static int sbc_check_valid_sectors(struct se_cmd *cmd)
{
struct se_device *dev = cmd->se_dev;
unsigned long long end_lba;
u32 sectors;
sectors = cmd->data_length / dev->se_sub_dev->se_dev_attrib.block_size;
end_lba = dev->transport->get_blocks(dev) + 1;
if (cmd->t_task_lba + sectors > end_lba) {
pr_err("target: lba %llu, sectors %u exceeds end lba %llu\n",
cmd->t_task_lba, sectors, end_lba);
return -EINVAL;
}
return 0;
}
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 int sbc_write_same_supported(struct se_device *dev,
unsigned char *flags)
{
if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
pr_err("WRITE_SAME PBDATA and LBDATA"
" bits not supported for Block Discard"
" Emulation\n");
return -ENOSYS;
}
/*
* Currently for the emulated case we only accept
* tpws with the UNMAP=1 bit set.
*/
if (!(flags[0] & 0x08)) {
pr_err("WRITE_SAME w/o UNMAP bit not"
" supported for Block Discard Emulation\n");
return -ENOSYS;
}
return 0;
}
static void xdreadwrite_callback(struct se_cmd *cmd)
{
unsigned char *buf, *addr;
struct scatterlist *sg;
unsigned int offset;
int i;
int 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;
}
/*
* 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)
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);
}
int sbc_parse_cdb(struct se_cmd *cmd, struct spc_ops *ops)
{
struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
struct se_device *dev = cmd->se_dev;
unsigned char *cdb = cmd->t_task_cdb;
unsigned int size;
u32 sectors = 0;
int ret;
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 = ops->execute_rw;
break;
case READ_10:
sectors = transport_get_sectors_10(cdb);
cmd->t_task_lba = transport_lba_32(cdb);
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
cmd->execute_cmd = ops->execute_rw;
break;
case READ_12:
sectors = transport_get_sectors_12(cdb);
cmd->t_task_lba = transport_lba_32(cdb);
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
cmd->execute_cmd = ops->execute_rw;
break;
case READ_16:
sectors = transport_get_sectors_16(cdb);
cmd->t_task_lba = transport_lba_64(cdb);
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
cmd->execute_cmd = ops->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 = ops->execute_rw;
break;
case WRITE_10:
case WRITE_VERIFY:
sectors = transport_get_sectors_10(cdb);
cmd->t_task_lba = transport_lba_32(cdb);
if (cdb[1] & 0x8)
cmd->se_cmd_flags |= SCF_FUA;
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
cmd->execute_cmd = ops->execute_rw;
break;
case WRITE_12:
sectors = transport_get_sectors_12(cdb);
cmd->t_task_lba = transport_lba_32(cdb);
if (cdb[1] & 0x8)
cmd->se_cmd_flags |= SCF_FUA;
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
cmd->execute_cmd = ops->execute_rw;
break;
case WRITE_16:
sectors = transport_get_sectors_16(cdb);
cmd->t_task_lba = transport_lba_64(cdb);
if (cdb[1] & 0x8)
cmd->se_cmd_flags |= SCF_FUA;
cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
cmd->execute_cmd = ops->execute_rw;
break;
case XDWRITEREAD_10:
if ((cmd->data_direction != DMA_TO_DEVICE) ||
!(cmd->se_cmd_flags & SCF_BIDI))
goto out_invalid_cdb_field;
sectors = transport_get_sectors_10(cdb);
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 = ops->execute_rw;
cmd->transport_complete_callback = &xdreadwrite_callback;
if (cdb[1] & 0x8)
cmd->se_cmd_flags |= SCF_FUA;
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);
/*
* 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 = ops->execute_rw;
cmd->transport_complete_callback = &xdreadwrite_callback;
if (cdb[1] & 0x8)
cmd->se_cmd_flags |= SCF_FUA;
break;
case WRITE_SAME_32:
if (!ops->execute_write_same)
goto out_unsupported_cdb;
sectors = transport_get_sectors_32(cdb);
if (!sectors) {
pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
" supported\n");
goto out_invalid_cdb_field;
}
size = sbc_get_size(cmd, 1);
cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
if (sbc_write_same_supported(dev, &cdb[10]) < 0)
goto out_unsupported_cdb;
cmd->execute_cmd = ops->execute_write_same;
break;
default:
pr_err("VARIABLE_LENGTH_CMD service action"
" 0x%04x not supported\n", service_action);
goto out_unsupported_cdb;
}
break;
}
case READ_CAPACITY:
size = READ_CAP_LEN;
cmd->execute_cmd = sbc_emulate_readcapacity;
break;
case SERVICE_ACTION_IN:
switch (cmd->t_task_cdb[1] & 0x1f) {
case SAI_READ_CAPACITY_16:
cmd->execute_cmd = sbc_emulate_readcapacity_16;
break;
default:
pr_err("Unsupported SA: 0x%02x\n",
cmd->t_task_cdb[1] & 0x1f);
goto out_invalid_cdb_field;
}
size = (cdb[10] << 24) | (cdb[11] << 16) |
(cdb[12] << 8) | cdb[13];
break;
case SYNCHRONIZE_CACHE:
case SYNCHRONIZE_CACHE_16:
if (!ops->execute_sync_cache)
goto out_unsupported_cdb;
/*
* Extract LBA and range to be flushed for emulated SYNCHRONIZE_CACHE
*/
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);
}
size = sbc_get_size(cmd, sectors);
/*
* Check to ensure that LBA + Range does not exceed past end of
* device for IBLOCK and FILEIO ->do_sync_cache() backend calls
*/
if (cmd->t_task_lba || sectors) {
if (sbc_check_valid_sectors(cmd) < 0)
goto out_invalid_cdb_field;
}
cmd->execute_cmd = ops->execute_sync_cache;
break;
case UNMAP:
if (!ops->execute_unmap)
goto out_unsupported_cdb;
size = get_unaligned_be16(&cdb[7]);
cmd->execute_cmd = ops->execute_unmap;
break;
case WRITE_SAME_16:
if (!ops->execute_write_same)
goto out_unsupported_cdb;
sectors = transport_get_sectors_16(cdb);
if (!sectors) {
pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
goto out_invalid_cdb_field;
}
size = sbc_get_size(cmd, 1);
cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
if (sbc_write_same_supported(dev, &cdb[1]) < 0)
goto out_unsupported_cdb;
cmd->execute_cmd = ops->execute_write_same;
break;
case WRITE_SAME:
if (!ops->execute_write_same)
goto out_unsupported_cdb;
sectors = transport_get_sectors_10(cdb);
if (!sectors) {
pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
goto out_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
*/
if (sbc_write_same_supported(dev, &cdb[1]) < 0)
goto out_unsupported_cdb;
cmd->execute_cmd = ops->execute_write_same;
break;
case VERIFY:
size = 0;
cmd->execute_cmd = sbc_emulate_verify;
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->se_cmd_flags & SCF_SCSI_DATA_CDB) && !cmd->execute_cmd)
goto out_unsupported_cdb;
if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
unsigned long long end_lba;
if (sectors > su_dev->se_dev_attrib.fabric_max_sectors) {
printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
" big sectors %u exceeds fabric_max_sectors:"
" %u\n", cdb[0], sectors,
su_dev->se_dev_attrib.fabric_max_sectors);
goto out_invalid_cdb_field;
}
if (sectors > su_dev->se_dev_attrib.hw_max_sectors) {
printk_ratelimited(KERN_ERR "SCSI OP %02xh with too"
" big sectors %u exceeds backend hw_max_sectors:"
" %u\n", cdb[0], sectors,
su_dev->se_dev_attrib.hw_max_sectors);
goto out_invalid_cdb_field;
}
end_lba = dev->transport->get_blocks(dev) + 1;
if (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);
goto out_invalid_cdb_field;
}
size = sbc_get_size(cmd, sectors);
}
ret = target_cmd_size_check(cmd, size);
if (ret < 0)
return ret;
return 0;
out_unsupported_cdb:
cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
return -EINVAL;
out_invalid_cdb_field:
cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
return -EINVAL;
}
EXPORT_SYMBOL(sbc_parse_cdb);
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