target_core_sbc.c 25.4 KB
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/*
 * SCSI Block Commands (SBC) parsing and emulation.
 *
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 * (c) Copyright 2002-2013 Datera, Inc.
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 *
 * 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>
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#include <scsi/scsi_tcq.h>
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#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"


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static sense_reason_t
sbc_emulate_readcapacity(struct se_cmd *cmd)
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{
	struct se_device *dev = cmd->se_dev;
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	unsigned char *cdb = cmd->t_task_cdb;
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	unsigned long long blocks_long = dev->transport->get_blocks(dev);
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	unsigned char *rbuf;
	unsigned char buf[8];
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	u32 blocks;

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	/*
	 * 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;

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	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;
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	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;
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	rbuf = transport_kmap_data_sg(cmd);
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	if (rbuf) {
		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
		transport_kunmap_data_sg(cmd);
	}
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	target_complete_cmd_with_length(cmd, GOOD, 8);
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	return 0;
}

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static sense_reason_t
sbc_emulate_readcapacity_16(struct se_cmd *cmd)
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{
	struct se_device *dev = cmd->se_dev;
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	unsigned char *rbuf;
	unsigned char buf[32];
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	unsigned long long blocks = dev->transport->get_blocks(dev);

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	memset(buf, 0, sizeof(buf));
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	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;
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	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;
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	/*
	 * Set Thin Provisioning Enable bit following sbc3r22 in section
	 * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
	 */
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	if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws)
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		buf[14] = 0x80;

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	rbuf = transport_kmap_data_sg(cmd);
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	if (rbuf) {
		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
		transport_kunmap_data_sg(cmd);
	}
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	target_complete_cmd_with_length(cmd, GOOD, 32);
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	return 0;
}

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sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
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{
	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.
	 */
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	if (num_blocks)
		return num_blocks;
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	return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
		cmd->t_task_lba + 1;
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}
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EXPORT_SYMBOL(sbc_get_write_same_sectors);
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static sense_reason_t
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sbc_emulate_noop(struct se_cmd *cmd)
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{
	target_complete_cmd(cmd, GOOD);
	return 0;
}

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static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
{
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	return cmd->se_dev->dev_attrib.block_size * sectors;
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}

static int sbc_check_valid_sectors(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;
	unsigned long long end_lba;
	u32 sectors;

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	sectors = cmd->data_length / dev->dev_attrib.block_size;
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	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;
}

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static sense_reason_t
sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
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{
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	struct se_device *dev = cmd->se_dev;
	sector_t end_lba = dev->transport->get_blocks(dev) + 1;
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	unsigned int sectors = sbc_get_write_same_sectors(cmd);
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	if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
		pr_err("WRITE_SAME PBDATA and LBDATA"
			" bits not supported for Block Discard"
			" Emulation\n");
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		return TCM_UNSUPPORTED_SCSI_OPCODE;
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	}
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	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;
	}
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	/*
	 * 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;
	}

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	/* 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;
	}
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	/*
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	 * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
	 * translated into block discard requests within backend code.
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	 */
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	if (flags[0] & 0x08) {
		if (!ops->execute_write_same_unmap)
			return TCM_UNSUPPORTED_SCSI_OPCODE;

		cmd->execute_cmd = ops->execute_write_same_unmap;
		return 0;
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	}
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	if (!ops->execute_write_same)
		return TCM_UNSUPPORTED_SCSI_OPCODE;
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	cmd->execute_cmd = ops->execute_write_same;
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	return 0;
}

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static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd)
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{
	unsigned char *buf, *addr;
	struct scatterlist *sg;
	unsigned int offset;
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	sense_reason_t ret = TCM_NO_SENSE;
	int i, count;
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	/*
	 * 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");
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		return TCM_OUT_OF_RESOURCES;
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	}
	/*
	 * 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));
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		if (!addr) {
			ret = TCM_OUT_OF_RESOURCES;
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			goto out;
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		}
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		for (i = 0; i < sg->length; i++)
			*(addr + sg->offset + i) ^= *(buf + offset + i);

		offset += sg->length;
		kunmap_atomic(addr);
	}

out:
	kfree(buf);
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	return ret;
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}

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static sense_reason_t
sbc_execute_rw(struct se_cmd *cmd)
{
	return cmd->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
			       cmd->data_direction);
}

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static sense_reason_t compare_and_write_post(struct se_cmd *cmd)
{
	struct se_device *dev = cmd->se_dev;

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	/*
	 * 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;
	spin_unlock_irq(&cmd->t_state_lock);

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	/*
	 * 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)
{
	struct se_device *dev = cmd->se_dev;
	struct scatterlist *write_sg = NULL, *sg;
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	unsigned char *buf = NULL, *addr;
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	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;

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	/*
	 * Handle early failure in transport_generic_request_failure(),
	 * which will not have taken ->caw_mutex yet..
	 */
	if (!cmd->t_data_sg || !cmd->t_bidi_data_sg)
		return TCM_NO_SENSE;
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	/*
	 * 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;
	}
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	buf = kzalloc(cmd->data_length, GFP_KERNEL);
	if (!buf) {
		pr_err("Unable to allocate compare_and_write buf\n");
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		ret = TCM_OUT_OF_RESOURCES;
		goto out;
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	}

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	write_sg = kmalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
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			   GFP_KERNEL);
	if (!write_sg) {
		pr_err("Unable to allocate compare_and_write sg\n");
		ret = TCM_OUT_OF_RESOURCES;
		goto out;
	}
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	sg_init_table(write_sg, cmd->t_data_nents);
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	/*
	 * 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,
				    block_size);
		} else {
			sg_miter_next(&m);
			sg_set_page(&write_sg[i], m.page, block_size,
				    0);
		}
		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 = MSG_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 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) || signal_pending(current)) {
		cmd->transport_complete_callback = NULL;
		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
	}
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	/*
	 * 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;
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	ret = cmd->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;
}

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sense_reason_t
sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
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{
	struct se_device *dev = cmd->se_dev;
	unsigned char *cdb = cmd->t_task_cdb;
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	unsigned int size;
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	u32 sectors = 0;
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	sense_reason_t ret;
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	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;
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		cmd->execute_rw = ops->execute_rw;
		cmd->execute_cmd = sbc_execute_rw;
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		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;
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		cmd->execute_rw = ops->execute_rw;
		cmd->execute_cmd = sbc_execute_rw;
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		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;
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		cmd->execute_rw = ops->execute_rw;
		cmd->execute_cmd = sbc_execute_rw;
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		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;
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		cmd->execute_rw = ops->execute_rw;
		cmd->execute_cmd = sbc_execute_rw;
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		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;
611 612
		cmd->execute_rw = ops->execute_rw;
		cmd->execute_cmd = sbc_execute_rw;
613 614 615 616 617 618 619 620
		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;
621 622
		cmd->execute_rw = ops->execute_rw;
		cmd->execute_cmd = sbc_execute_rw;
623 624 625 626 627 628 629
		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;
630 631
		cmd->execute_rw = ops->execute_rw;
		cmd->execute_cmd = sbc_execute_rw;
632 633 634 635 636 637 638
		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;
639 640
		cmd->execute_rw = ops->execute_rw;
		cmd->execute_cmd = sbc_execute_rw;
641 642
		break;
	case XDWRITEREAD_10:
643
		if (cmd->data_direction != DMA_TO_DEVICE ||
644
		    !(cmd->se_cmd_flags & SCF_BIDI))
645
			return TCM_INVALID_CDB_FIELD;
646 647 648 649 650 651 652 653
		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.
		 */
654 655
		cmd->execute_rw = ops->execute_rw;
		cmd->execute_cmd = sbc_execute_rw;
656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677
		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.
			 */
678 679
			cmd->execute_rw = ops->execute_rw;
			cmd->execute_cmd = sbc_execute_rw;
680 681 682 683 684 685 686 687 688
			cmd->transport_complete_callback = &xdreadwrite_callback;
			if (cdb[1] & 0x8)
				cmd->se_cmd_flags |= SCF_FUA;
			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");
689
				return TCM_INVALID_CDB_FIELD;
690 691
			}

692
			size = sbc_get_size(cmd, 1);
693 694
			cmd->t_task_lba = get_unaligned_be64(&cdb[12]);

695
			ret = sbc_setup_write_same(cmd, &cdb[10], ops);
696
			if (ret)
697
				return ret;
698 699 700 701
			break;
		default:
			pr_err("VARIABLE_LENGTH_CMD service action"
				" 0x%04x not supported\n", service_action);
702
			return TCM_UNSUPPORTED_SCSI_OPCODE;
703 704 705
		}
		break;
	}
706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727
	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;
		}
		/*
		 * 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_rw = ops->execute_rw;
		cmd->execute_cmd = sbc_compare_and_write;
		cmd->transport_complete_callback = compare_and_write_callback;
		break;
728
	case READ_CAPACITY:
729 730
		size = READ_CAP_LEN;
		cmd->execute_cmd = sbc_emulate_readcapacity;
731 732 733 734
		break;
	case SERVICE_ACTION_IN:
		switch (cmd->t_task_cdb[1] & 0x1f) {
		case SAI_READ_CAPACITY_16:
735
			cmd->execute_cmd = sbc_emulate_readcapacity_16;
736 737 738 739
			break;
		default:
			pr_err("Unsupported SA: 0x%02x\n",
				cmd->t_task_cdb[1] & 0x1f);
740
			return TCM_INVALID_CDB_FIELD;
741
		}
742
		size = (cdb[10] << 24) | (cdb[11] << 16) |
743 744 745 746
		       (cdb[12] << 8) | cdb[13];
		break;
	case SYNCHRONIZE_CACHE:
	case SYNCHRONIZE_CACHE_16:
747 748 749 750 751
		if (!ops->execute_sync_cache) {
			size = 0;
			cmd->execute_cmd = sbc_emulate_noop;
			break;
		}
752

753 754 755 756 757 758 759 760 761 762 763
		/*
		 * 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);
		}

764
		size = sbc_get_size(cmd, sectors);
765 766 767 768 769 770 771

		/*
		 * 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)
772
				return TCM_ADDRESS_OUT_OF_RANGE;
773
		}
774
		cmd->execute_cmd = ops->execute_sync_cache;
775 776
		break;
	case UNMAP:
777
		if (!ops->execute_unmap)
778
			return TCM_UNSUPPORTED_SCSI_OPCODE;
779

780
		size = get_unaligned_be16(&cdb[7]);
781
		cmd->execute_cmd = ops->execute_unmap;
782 783 784 785 786
		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");
787
			return TCM_INVALID_CDB_FIELD;
788 789
		}

790
		size = sbc_get_size(cmd, 1);
791 792
		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);

793
		ret = sbc_setup_write_same(cmd, &cdb[1], ops);
794
		if (ret)
795
			return ret;
796 797 798 799 800
		break;
	case WRITE_SAME:
		sectors = transport_get_sectors_10(cdb);
		if (!sectors) {
			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
801
			return TCM_INVALID_CDB_FIELD;
802 803
		}

804
		size = sbc_get_size(cmd, 1);
805 806 807 808 809 810
		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
		 */
811
		ret = sbc_setup_write_same(cmd, &cdb[1], ops);
812
		if (ret)
813
			return ret;
814 815
		break;
	case VERIFY:
816
		size = 0;
817
		cmd->execute_cmd = sbc_emulate_noop;
818
		break;
819 820 821 822 823 824 825 826 827 828 829 830
	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;
831
	default:
832
		ret = spc_parse_cdb(cmd, &size);
833 834 835 836 837 838
		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)
839
		return TCM_UNSUPPORTED_SCSI_OPCODE;
840 841

	if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
842 843 844 845 846 847 848
		unsigned long long end_lba;

		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);
849
			return TCM_ADDRESS_OUT_OF_RANGE;
850 851
		}

852 853
		if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
			size = sbc_get_size(cmd, sectors);
854 855
	}

856
	return target_cmd_size_check(cmd, size);
857 858
}
EXPORT_SYMBOL(sbc_parse_cdb);
859 860 861 862 863 864

u32 sbc_get_device_type(struct se_device *dev)
{
	return TYPE_DISK;
}
EXPORT_SYMBOL(sbc_get_device_type);
865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949

sense_reason_t
sbc_execute_unmap(struct se_cmd *cmd,
	sense_reason_t (*do_unmap_fn)(struct se_cmd *, void *,
				      sector_t, sector_t),
	void *priv)
{
	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 = do_unmap_fn(cmd, priv, 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;
}
EXPORT_SYMBOL(sbc_execute_unmap);