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   1/*
   2 * SCSI Block Commands (SBC) parsing and emulation.
   3 *
   4 * (c) Copyright 2002-2013 Datera, Inc.
   5 *
   6 * Nicholas A. Bellinger <nab@kernel.org>
   7 *
   8 * This program is free software; you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License as published by
  10 * the Free Software Foundation; either version 2 of the License, or
  11 * (at your option) any later version.
  12 *
  13 * This program is distributed in the hope that it will be useful,
  14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 * GNU General Public License for more details.
  17 *
  18 * You should have received a copy of the GNU General Public License
  19 * along with this program; if not, write to the Free Software
  20 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  21 */
  22
  23#include <linux/kernel.h>
  24#include <linux/module.h>
  25#include <linux/ratelimit.h>
  26#include <linux/crc-t10dif.h>
  27#include <asm/unaligned.h>
  28#include <scsi/scsi_proto.h>
  29#include <scsi/scsi_tcq.h>
  30
  31#include <target/target_core_base.h>
  32#include <target/target_core_backend.h>
  33#include <target/target_core_fabric.h>
  34
  35#include "target_core_internal.h"
  36#include "target_core_ua.h"
  37#include "target_core_alua.h"
  38
  39static sense_reason_t
  40sbc_check_prot(struct se_device *, struct se_cmd *, unsigned char *, u32, bool);
  41static sense_reason_t sbc_execute_unmap(struct se_cmd *cmd);
  42
  43static sense_reason_t
  44sbc_emulate_readcapacity(struct se_cmd *cmd)
  45{
  46	struct se_device *dev = cmd->se_dev;
  47	unsigned char *cdb = cmd->t_task_cdb;
  48	unsigned long long blocks_long = dev->transport->get_blocks(dev);
  49	unsigned char *rbuf;
  50	unsigned char buf[8];
  51	u32 blocks;
  52
  53	/*
  54	 * SBC-2 says:
  55	 *   If the PMI bit is set to zero and the LOGICAL BLOCK
  56	 *   ADDRESS field is not set to zero, the device server shall
  57	 *   terminate the command with CHECK CONDITION status with
  58	 *   the sense key set to ILLEGAL REQUEST and the additional
  59	 *   sense code set to INVALID FIELD IN CDB.
  60	 *
  61	 * In SBC-3, these fields are obsolete, but some SCSI
  62	 * compliance tests actually check this, so we might as well
  63	 * follow SBC-2.
  64	 */
  65	if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
  66		return TCM_INVALID_CDB_FIELD;
  67
  68	if (blocks_long >= 0x00000000ffffffff)
  69		blocks = 0xffffffff;
  70	else
  71		blocks = (u32)blocks_long;
  72
  73	buf[0] = (blocks >> 24) & 0xff;
  74	buf[1] = (blocks >> 16) & 0xff;
  75	buf[2] = (blocks >> 8) & 0xff;
  76	buf[3] = blocks & 0xff;
  77	buf[4] = (dev->dev_attrib.block_size >> 24) & 0xff;
  78	buf[5] = (dev->dev_attrib.block_size >> 16) & 0xff;
  79	buf[6] = (dev->dev_attrib.block_size >> 8) & 0xff;
  80	buf[7] = dev->dev_attrib.block_size & 0xff;
  81
  82	rbuf = transport_kmap_data_sg(cmd);
  83	if (rbuf) {
  84		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
  85		transport_kunmap_data_sg(cmd);
  86	}
  87
  88	target_complete_cmd_with_length(cmd, GOOD, 8);
  89	return 0;
  90}
  91
  92static sense_reason_t
  93sbc_emulate_readcapacity_16(struct se_cmd *cmd)
  94{
  95	struct se_device *dev = cmd->se_dev;
  96	struct se_session *sess = cmd->se_sess;
  97	int pi_prot_type = dev->dev_attrib.pi_prot_type;
  98
  99	unsigned char *rbuf;
 100	unsigned char buf[32];
 101	unsigned long long blocks = dev->transport->get_blocks(dev);
 102
 103	memset(buf, 0, sizeof(buf));
 104	buf[0] = (blocks >> 56) & 0xff;
 105	buf[1] = (blocks >> 48) & 0xff;
 106	buf[2] = (blocks >> 40) & 0xff;
 107	buf[3] = (blocks >> 32) & 0xff;
 108	buf[4] = (blocks >> 24) & 0xff;
 109	buf[5] = (blocks >> 16) & 0xff;
 110	buf[6] = (blocks >> 8) & 0xff;
 111	buf[7] = blocks & 0xff;
 112	buf[8] = (dev->dev_attrib.block_size >> 24) & 0xff;
 113	buf[9] = (dev->dev_attrib.block_size >> 16) & 0xff;
 114	buf[10] = (dev->dev_attrib.block_size >> 8) & 0xff;
 115	buf[11] = dev->dev_attrib.block_size & 0xff;
 116	/*
 117	 * Set P_TYPE and PROT_EN bits for DIF support
 118	 */
 119	if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
 120		/*
 121		 * Only override a device's pi_prot_type if no T10-PI is
 122		 * available, and sess_prot_type has been explicitly enabled.
 123		 */
 124		if (!pi_prot_type)
 125			pi_prot_type = sess->sess_prot_type;
 126
 127		if (pi_prot_type)
 128			buf[12] = (pi_prot_type - 1) << 1 | 0x1;
 129	}
 130
 131	if (dev->transport->get_lbppbe)
 132		buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
 133
 134	if (dev->transport->get_alignment_offset_lbas) {
 135		u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
 136		buf[14] = (lalba >> 8) & 0x3f;
 137		buf[15] = lalba & 0xff;
 138	}
 139
 140	/*
 141	 * Set Thin Provisioning Enable bit following sbc3r22 in section
 142	 * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
 143	 */
 144	if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws) {
 145		buf[14] |= 0x80;
 146
 147		/*
 148		 * LBPRZ signifies that zeroes will be read back from an LBA after
 149		 * an UNMAP or WRITE SAME w/ unmap bit (sbc3r36 5.16.2)
 150		 */
 151		if (dev->dev_attrib.unmap_zeroes_data)
 152			buf[14] |= 0x40;
 153	}
 154
 155	rbuf = transport_kmap_data_sg(cmd);
 156	if (rbuf) {
 157		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
 158		transport_kunmap_data_sg(cmd);
 159	}
 160
 161	target_complete_cmd_with_length(cmd, GOOD, 32);
 162	return 0;
 163}
 164
 165static sense_reason_t
 166sbc_emulate_startstop(struct se_cmd *cmd)
 167{
 168	unsigned char *cdb = cmd->t_task_cdb;
 169
 170	/*
 171	 * See sbc3r36 section 5.25
 172	 * Immediate bit should be set since there is nothing to complete
 173	 * POWER CONDITION MODIFIER 0h
 174	 */
 175	if (!(cdb[1] & 1) || cdb[2] || cdb[3])
 176		return TCM_INVALID_CDB_FIELD;
 177
 178	/*
 179	 * See sbc3r36 section 5.25
 180	 * POWER CONDITION 0h START_VALID - process START and LOEJ
 181	 */
 182	if (cdb[4] >> 4 & 0xf)
 183		return TCM_INVALID_CDB_FIELD;
 184
 185	/*
 186	 * See sbc3r36 section 5.25
 187	 * LOEJ 0h - nothing to load or unload
 188	 * START 1h - we are ready
 189	 */
 190	if (!(cdb[4] & 1) || (cdb[4] & 2) || (cdb[4] & 4))
 191		return TCM_INVALID_CDB_FIELD;
 192
 193	target_complete_cmd(cmd, SAM_STAT_GOOD);
 194	return 0;
 195}
 196
 197sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
 198{
 199	u32 num_blocks;
 200
 201	if (cmd->t_task_cdb[0] == WRITE_SAME)
 202		num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
 203	else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
 204		num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
 205	else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
 206		num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
 207
 208	/*
 209	 * Use the explicit range when non zero is supplied, otherwise calculate
 210	 * the remaining range based on ->get_blocks() - starting LBA.
 211	 */
 212	if (num_blocks)
 213		return num_blocks;
 214
 215	return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
 216		cmd->t_task_lba + 1;
 217}
 218EXPORT_SYMBOL(sbc_get_write_same_sectors);
 219
 220static sense_reason_t
 221sbc_execute_write_same_unmap(struct se_cmd *cmd)
 222{
 223	struct sbc_ops *ops = cmd->protocol_data;
 224	sector_t nolb = sbc_get_write_same_sectors(cmd);
 225	sense_reason_t ret;
 226
 227	if (nolb) {
 228		ret = ops->execute_unmap(cmd, cmd->t_task_lba, nolb);
 229		if (ret)
 230			return ret;
 231	}
 232
 233	target_complete_cmd(cmd, GOOD);
 234	return 0;
 235}
 236
 237static sense_reason_t
 238sbc_emulate_noop(struct se_cmd *cmd)
 239{
 240	target_complete_cmd(cmd, GOOD);
 241	return 0;
 242}
 243
 244static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
 245{
 246	return cmd->se_dev->dev_attrib.block_size * sectors;
 247}
 248
 249static inline u32 transport_get_sectors_6(unsigned char *cdb)
 250{
 251	/*
 252	 * Use 8-bit sector value.  SBC-3 says:
 253	 *
 254	 *   A TRANSFER LENGTH field set to zero specifies that 256
 255	 *   logical blocks shall be written.  Any other value
 256	 *   specifies the number of logical blocks that shall be
 257	 *   written.
 258	 */
 259	return cdb[4] ? : 256;
 260}
 261
 262static inline u32 transport_get_sectors_10(unsigned char *cdb)
 263{
 264	return (u32)(cdb[7] << 8) + cdb[8];
 265}
 266
 267static inline u32 transport_get_sectors_12(unsigned char *cdb)
 268{
 269	return (u32)(cdb[6] << 24) + (cdb[7] << 16) + (cdb[8] << 8) + cdb[9];
 270}
 271
 272static inline u32 transport_get_sectors_16(unsigned char *cdb)
 273{
 274	return (u32)(cdb[10] << 24) + (cdb[11] << 16) +
 275		    (cdb[12] << 8) + cdb[13];
 276}
 277
 278/*
 279 * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
 280 */
 281static inline u32 transport_get_sectors_32(unsigned char *cdb)
 282{
 283	return (u32)(cdb[28] << 24) + (cdb[29] << 16) +
 284		    (cdb[30] << 8) + cdb[31];
 285
 286}
 287
 288static inline u32 transport_lba_21(unsigned char *cdb)
 289{
 290	return ((cdb[1] & 0x1f) << 16) | (cdb[2] << 8) | cdb[3];
 291}
 292
 293static inline u32 transport_lba_32(unsigned char *cdb)
 294{
 295	return (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 296}
 297
 298static inline unsigned long long transport_lba_64(unsigned char *cdb)
 299{
 300	unsigned int __v1, __v2;
 301
 302	__v1 = (cdb[2] << 24) | (cdb[3] << 16) | (cdb[4] << 8) | cdb[5];
 303	__v2 = (cdb[6] << 24) | (cdb[7] << 16) | (cdb[8] << 8) | cdb[9];
 304
 305	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 306}
 307
 308/*
 309 * For VARIABLE_LENGTH_CDB w/ 32 byte extended CDBs
 310 */
 311static inline unsigned long long transport_lba_64_ext(unsigned char *cdb)
 312{
 313	unsigned int __v1, __v2;
 314
 315	__v1 = (cdb[12] << 24) | (cdb[13] << 16) | (cdb[14] << 8) | cdb[15];
 316	__v2 = (cdb[16] << 24) | (cdb[17] << 16) | (cdb[18] << 8) | cdb[19];
 317
 318	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
 319}
 320
 321static sense_reason_t
 322sbc_setup_write_same(struct se_cmd *cmd, unsigned char *flags, struct sbc_ops *ops)
 323{
 324	struct se_device *dev = cmd->se_dev;
 325	sector_t end_lba = dev->transport->get_blocks(dev) + 1;
 326	unsigned int sectors = sbc_get_write_same_sectors(cmd);
 327	sense_reason_t ret;
 328
 329	if ((flags[0] & 0x04) || (flags[0] & 0x02)) {
 330		pr_err("WRITE_SAME PBDATA and LBDATA"
 331			" bits not supported for Block Discard"
 332			" Emulation\n");
 333		return TCM_UNSUPPORTED_SCSI_OPCODE;
 334	}
 335	if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
 336		pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
 337			sectors, cmd->se_dev->dev_attrib.max_write_same_len);
 338		return TCM_INVALID_CDB_FIELD;
 339	}
 340	/*
 341	 * Sanity check for LBA wrap and request past end of device.
 342	 */
 343	if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
 344	    ((cmd->t_task_lba + sectors) > end_lba)) {
 345		pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
 346		       (unsigned long long)end_lba, cmd->t_task_lba, sectors);
 347		return TCM_ADDRESS_OUT_OF_RANGE;
 348	}
 349
 350	/* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
 351	if (flags[0] & 0x10) {
 352		pr_warn("WRITE SAME with ANCHOR not supported\n");
 353		return TCM_INVALID_CDB_FIELD;
 354	}
 355	/*
 356	 * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
 357	 * translated into block discard requests within backend code.
 358	 */
 359	if (flags[0] & 0x08) {
 360		if (!ops->execute_unmap)
 361			return TCM_UNSUPPORTED_SCSI_OPCODE;
 362
 363		if (!dev->dev_attrib.emulate_tpws) {
 364			pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
 365			       " has emulate_tpws disabled\n");
 366			return TCM_UNSUPPORTED_SCSI_OPCODE;
 367		}
 368		cmd->execute_cmd = sbc_execute_write_same_unmap;
 369		return 0;
 370	}
 371	if (!ops->execute_write_same)
 372		return TCM_UNSUPPORTED_SCSI_OPCODE;
 373
 374	ret = sbc_check_prot(dev, cmd, &cmd->t_task_cdb[0], sectors, true);
 375	if (ret)
 376		return ret;
 377
 378	cmd->execute_cmd = ops->execute_write_same;
 379	return 0;
 380}
 381
 382static sense_reason_t xdreadwrite_callback(struct se_cmd *cmd, bool success,
 383					   int *post_ret)
 384{
 385	unsigned char *buf, *addr;
 386	struct scatterlist *sg;
 387	unsigned int offset;
 388	sense_reason_t ret = TCM_NO_SENSE;
 389	int i, count;
 390	/*
 391	 * From sbc3r22.pdf section 5.48 XDWRITEREAD (10) command
 392	 *
 393	 * 1) read the specified logical block(s);
 394	 * 2) transfer logical blocks from the data-out buffer;
 395	 * 3) XOR the logical blocks transferred from the data-out buffer with
 396	 *    the logical blocks read, storing the resulting XOR data in a buffer;
 397	 * 4) if the DISABLE WRITE bit is set to zero, then write the logical
 398	 *    blocks transferred from the data-out buffer; and
 399	 * 5) transfer the resulting XOR data to the data-in buffer.
 400	 */
 401	buf = kmalloc(cmd->data_length, GFP_KERNEL);
 402	if (!buf) {
 403		pr_err("Unable to allocate xor_callback buf\n");
 404		return TCM_OUT_OF_RESOURCES;
 405	}
 406	/*
 407	 * Copy the scatterlist WRITE buffer located at cmd->t_data_sg
 408	 * into the locally allocated *buf
 409	 */
 410	sg_copy_to_buffer(cmd->t_data_sg,
 411			  cmd->t_data_nents,
 412			  buf,
 413			  cmd->data_length);
 414
 415	/*
 416	 * Now perform the XOR against the BIDI read memory located at
 417	 * cmd->t_mem_bidi_list
 418	 */
 419
 420	offset = 0;
 421	for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, count) {
 422		addr = kmap_atomic(sg_page(sg));
 423		if (!addr) {
 424			ret = TCM_OUT_OF_RESOURCES;
 425			goto out;
 426		}
 427
 428		for (i = 0; i < sg->length; i++)
 429			*(addr + sg->offset + i) ^= *(buf + offset + i);
 430
 431		offset += sg->length;
 432		kunmap_atomic(addr);
 433	}
 434
 435out:
 436	kfree(buf);
 437	return ret;
 438}
 439
 440static sense_reason_t
 441sbc_execute_rw(struct se_cmd *cmd)
 442{
 443	struct sbc_ops *ops = cmd->protocol_data;
 444
 445	return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
 446			       cmd->data_direction);
 447}
 448
 449static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success,
 450					     int *post_ret)
 451{
 452	struct se_device *dev = cmd->se_dev;
 453
 454	/*
 455	 * Only set SCF_COMPARE_AND_WRITE_POST to force a response fall-through
 456	 * within target_complete_ok_work() if the command was successfully
 457	 * sent to the backend driver.
 458	 */
 459	spin_lock_irq(&cmd->t_state_lock);
 460	if ((cmd->transport_state & CMD_T_SENT) && !cmd->scsi_status) {
 461		cmd->se_cmd_flags |= SCF_COMPARE_AND_WRITE_POST;
 462		*post_ret = 1;
 463	}
 464	spin_unlock_irq(&cmd->t_state_lock);
 465
 466	/*
 467	 * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
 468	 * before the original READ I/O submission.
 469	 */
 470	up(&dev->caw_sem);
 471
 472	return TCM_NO_SENSE;
 473}
 474
 475static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success,
 476						 int *post_ret)
 477{
 478	struct se_device *dev = cmd->se_dev;
 479	struct scatterlist *write_sg = NULL, *sg;
 480	unsigned char *buf = NULL, *addr;
 481	struct sg_mapping_iter m;
 482	unsigned int offset = 0, len;
 483	unsigned int nlbas = cmd->t_task_nolb;
 484	unsigned int block_size = dev->dev_attrib.block_size;
 485	unsigned int compare_len = (nlbas * block_size);
 486	sense_reason_t ret = TCM_NO_SENSE;
 487	int rc, i;
 488
 489	/*
 490	 * Handle early failure in transport_generic_request_failure(),
 491	 * which will not have taken ->caw_sem yet..
 492	 */
 493	if (!success && (!cmd->t_data_sg || !cmd->t_bidi_data_sg))
 494		return TCM_NO_SENSE;
 495	/*
 496	 * Handle special case for zero-length COMPARE_AND_WRITE
 497	 */
 498	if (!cmd->data_length)
 499		goto out;
 500	/*
 501	 * Immediately exit + release dev->caw_sem if command has already
 502	 * been failed with a non-zero SCSI status.
 503	 */
 504	if (cmd->scsi_status) {
 505		pr_err("compare_and_write_callback: non zero scsi_status:"
 506			" 0x%02x\n", cmd->scsi_status);
 507		goto out;
 508	}
 509
 510	buf = kzalloc(cmd->data_length, GFP_KERNEL);
 511	if (!buf) {
 512		pr_err("Unable to allocate compare_and_write buf\n");
 513		ret = TCM_OUT_OF_RESOURCES;
 514		goto out;
 515	}
 516
 517	write_sg = kmalloc(sizeof(struct scatterlist) * cmd->t_data_nents,
 518			   GFP_KERNEL);
 519	if (!write_sg) {
 520		pr_err("Unable to allocate compare_and_write sg\n");
 521		ret = TCM_OUT_OF_RESOURCES;
 522		goto out;
 523	}
 524	sg_init_table(write_sg, cmd->t_data_nents);
 525	/*
 526	 * Setup verify and write data payloads from total NumberLBAs.
 527	 */
 528	rc = sg_copy_to_buffer(cmd->t_data_sg, cmd->t_data_nents, buf,
 529			       cmd->data_length);
 530	if (!rc) {
 531		pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
 532		ret = TCM_OUT_OF_RESOURCES;
 533		goto out;
 534	}
 535	/*
 536	 * Compare against SCSI READ payload against verify payload
 537	 */
 538	for_each_sg(cmd->t_bidi_data_sg, sg, cmd->t_bidi_data_nents, i) {
 539		addr = (unsigned char *)kmap_atomic(sg_page(sg));
 540		if (!addr) {
 541			ret = TCM_OUT_OF_RESOURCES;
 542			goto out;
 543		}
 544
 545		len = min(sg->length, compare_len);
 546
 547		if (memcmp(addr, buf + offset, len)) {
 548			pr_warn("Detected MISCOMPARE for addr: %p buf: %p\n",
 549				addr, buf + offset);
 550			kunmap_atomic(addr);
 551			goto miscompare;
 552		}
 553		kunmap_atomic(addr);
 554
 555		offset += len;
 556		compare_len -= len;
 557		if (!compare_len)
 558			break;
 559	}
 560
 561	i = 0;
 562	len = cmd->t_task_nolb * block_size;
 563	sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
 564	/*
 565	 * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
 566	 */
 567	while (len) {
 568		sg_miter_next(&m);
 569
 570		if (block_size < PAGE_SIZE) {
 571			sg_set_page(&write_sg[i], m.page, block_size,
 572				    m.piter.sg->offset + block_size);
 573		} else {
 574			sg_miter_next(&m);
 575			sg_set_page(&write_sg[i], m.page, block_size,
 576				    m.piter.sg->offset);
 577		}
 578		len -= block_size;
 579		i++;
 580	}
 581	sg_miter_stop(&m);
 582	/*
 583	 * Save the original SGL + nents values before updating to new
 584	 * assignments, to be released in transport_free_pages() ->
 585	 * transport_reset_sgl_orig()
 586	 */
 587	cmd->t_data_sg_orig = cmd->t_data_sg;
 588	cmd->t_data_sg = write_sg;
 589	cmd->t_data_nents_orig = cmd->t_data_nents;
 590	cmd->t_data_nents = 1;
 591
 592	cmd->sam_task_attr = TCM_HEAD_TAG;
 593	cmd->transport_complete_callback = compare_and_write_post;
 594	/*
 595	 * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
 596	 * for submitting the adjusted SGL to write instance user-data.
 597	 */
 598	cmd->execute_cmd = sbc_execute_rw;
 599
 600	spin_lock_irq(&cmd->t_state_lock);
 601	cmd->t_state = TRANSPORT_PROCESSING;
 602	cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
 603	spin_unlock_irq(&cmd->t_state_lock);
 604
 605	__target_execute_cmd(cmd);
 606
 607	kfree(buf);
 608	return ret;
 609
 610miscompare:
 611	pr_warn("Target/%s: Send MISCOMPARE check condition and sense\n",
 612		dev->transport->name);
 613	ret = TCM_MISCOMPARE_VERIFY;
 614out:
 615	/*
 616	 * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
 617	 * sbc_compare_and_write() before the original READ I/O submission.
 618	 */
 619	up(&dev->caw_sem);
 620	kfree(write_sg);
 621	kfree(buf);
 622	return ret;
 623}
 624
 625static sense_reason_t
 626sbc_compare_and_write(struct se_cmd *cmd)
 627{
 628	struct sbc_ops *ops = cmd->protocol_data;
 629	struct se_device *dev = cmd->se_dev;
 630	sense_reason_t ret;
 631	int rc;
 632	/*
 633	 * Submit the READ first for COMPARE_AND_WRITE to perform the
 634	 * comparision using SGLs at cmd->t_bidi_data_sg..
 635	 */
 636	rc = down_interruptible(&dev->caw_sem);
 637	if (rc != 0) {
 638		cmd->transport_complete_callback = NULL;
 639		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 640	}
 641	/*
 642	 * Reset cmd->data_length to individual block_size in order to not
 643	 * confuse backend drivers that depend on this value matching the
 644	 * size of the I/O being submitted.
 645	 */
 646	cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
 647
 648	ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
 649			      DMA_FROM_DEVICE);
 650	if (ret) {
 651		cmd->transport_complete_callback = NULL;
 652		up(&dev->caw_sem);
 653		return ret;
 654	}
 655	/*
 656	 * Unlock of dev->caw_sem to occur in compare_and_write_callback()
 657	 * upon MISCOMPARE, or in compare_and_write_done() upon completion
 658	 * of WRITE instance user-data.
 659	 */
 660	return TCM_NO_SENSE;
 661}
 662
 663static int
 664sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
 665		       bool is_write, struct se_cmd *cmd)
 666{
 667	if (is_write) {
 668		cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
 669			       protect ? TARGET_PROT_DOUT_PASS :
 670			       TARGET_PROT_DOUT_INSERT;
 671		switch (protect) {
 672		case 0x0:
 673		case 0x3:
 674			cmd->prot_checks = 0;
 675			break;
 676		case 0x1:
 677		case 0x5:
 678			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 679			if (prot_type == TARGET_DIF_TYPE1_PROT)
 680				cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 681			break;
 682		case 0x2:
 683			if (prot_type == TARGET_DIF_TYPE1_PROT)
 684				cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 685			break;
 686		case 0x4:
 687			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 688			break;
 689		default:
 690			pr_err("Unsupported protect field %d\n", protect);
 691			return -EINVAL;
 692		}
 693	} else {
 694		cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
 695			       protect ? TARGET_PROT_DIN_PASS :
 696			       TARGET_PROT_DIN_STRIP;
 697		switch (protect) {
 698		case 0x0:
 699		case 0x1:
 700		case 0x5:
 701			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 702			if (prot_type == TARGET_DIF_TYPE1_PROT)
 703				cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 704			break;
 705		case 0x2:
 706			if (prot_type == TARGET_DIF_TYPE1_PROT)
 707				cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 708			break;
 709		case 0x3:
 710			cmd->prot_checks = 0;
 711			break;
 712		case 0x4:
 713			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 714			break;
 715		default:
 716			pr_err("Unsupported protect field %d\n", protect);
 717			return -EINVAL;
 718		}
 719	}
 720
 721	return 0;
 722}
 723
 724static sense_reason_t
 725sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb,
 726	       u32 sectors, bool is_write)
 727{
 728	u8 protect = cdb[1] >> 5;
 729	int sp_ops = cmd->se_sess->sup_prot_ops;
 730	int pi_prot_type = dev->dev_attrib.pi_prot_type;
 731	bool fabric_prot = false;
 732
 733	if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
 734		if (unlikely(protect &&
 735		    !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
 736			pr_err("CDB contains protect bit, but device + fabric does"
 737			       " not advertise PROTECT=1 feature bit\n");
 738			return TCM_INVALID_CDB_FIELD;
 739		}
 740		if (cmd->prot_pto)
 741			return TCM_NO_SENSE;
 742	}
 743
 744	switch (dev->dev_attrib.pi_prot_type) {
 745	case TARGET_DIF_TYPE3_PROT:
 746		cmd->reftag_seed = 0xffffffff;
 747		break;
 748	case TARGET_DIF_TYPE2_PROT:
 749		if (protect)
 750			return TCM_INVALID_CDB_FIELD;
 751
 752		cmd->reftag_seed = cmd->t_task_lba;
 753		break;
 754	case TARGET_DIF_TYPE1_PROT:
 755		cmd->reftag_seed = cmd->t_task_lba;
 756		break;
 757	case TARGET_DIF_TYPE0_PROT:
 758		/*
 759		 * See if the fabric supports T10-PI, and the session has been
 760		 * configured to allow export PROTECT=1 feature bit with backend
 761		 * devices that don't support T10-PI.
 762		 */
 763		fabric_prot = is_write ?
 764			      !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
 765			      !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
 766
 767		if (fabric_prot && cmd->se_sess->sess_prot_type) {
 768			pi_prot_type = cmd->se_sess->sess_prot_type;
 769			break;
 770		}
 771		if (!protect)
 772			return TCM_NO_SENSE;
 773		/* Fallthrough */
 774	default:
 775		pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
 776		       "PROTECT: 0x%02x\n", cdb[0], protect);
 777		return TCM_INVALID_CDB_FIELD;
 778	}
 779
 780	if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
 781		return TCM_INVALID_CDB_FIELD;
 782
 783	cmd->prot_type = pi_prot_type;
 784	cmd->prot_length = dev->prot_length * sectors;
 785
 786	/**
 787	 * In case protection information exists over the wire
 788	 * we modify command data length to describe pure data.
 789	 * The actual transfer length is data length + protection
 790	 * length
 791	 **/
 792	if (protect)
 793		cmd->data_length = sectors * dev->dev_attrib.block_size;
 794
 795	pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
 796		 "prot_op=%d prot_checks=%d\n",
 797		 __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
 798		 cmd->prot_op, cmd->prot_checks);
 799
 800	return TCM_NO_SENSE;
 801}
 802
 803static int
 804sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
 805{
 806	if (cdb[1] & 0x10) {
 807		/* see explanation in spc_emulate_modesense */
 808		if (!target_check_fua(dev)) {
 809			pr_err("Got CDB: 0x%02x with DPO bit set, but device"
 810			       " does not advertise support for DPO\n", cdb[0]);
 811			return -EINVAL;
 812		}
 813	}
 814	if (cdb[1] & 0x8) {
 815		if (!target_check_fua(dev)) {
 816			pr_err("Got CDB: 0x%02x with FUA bit set, but device"
 817			       " does not advertise support for FUA write\n",
 818			       cdb[0]);
 819			return -EINVAL;
 820		}
 821		cmd->se_cmd_flags |= SCF_FUA;
 822	}
 823	return 0;
 824}
 825
 826sense_reason_t
 827sbc_parse_cdb(struct se_cmd *cmd, struct sbc_ops *ops)
 828{
 829	struct se_device *dev = cmd->se_dev;
 830	unsigned char *cdb = cmd->t_task_cdb;
 831	unsigned int size;
 832	u32 sectors = 0;
 833	sense_reason_t ret;
 834
 835	cmd->protocol_data = ops;
 836
 837	switch (cdb[0]) {
 838	case READ_6:
 839		sectors = transport_get_sectors_6(cdb);
 840		cmd->t_task_lba = transport_lba_21(cdb);
 841		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 842		cmd->execute_cmd = sbc_execute_rw;
 843		break;
 844	case READ_10:
 845		sectors = transport_get_sectors_10(cdb);
 846		cmd->t_task_lba = transport_lba_32(cdb);
 847
 848		if (sbc_check_dpofua(dev, cmd, cdb))
 849			return TCM_INVALID_CDB_FIELD;
 850
 851		ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 852		if (ret)
 853			return ret;
 854
 855		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 856		cmd->execute_cmd = sbc_execute_rw;
 857		break;
 858	case READ_12:
 859		sectors = transport_get_sectors_12(cdb);
 860		cmd->t_task_lba = transport_lba_32(cdb);
 861
 862		if (sbc_check_dpofua(dev, cmd, cdb))
 863			return TCM_INVALID_CDB_FIELD;
 864
 865		ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 866		if (ret)
 867			return ret;
 868
 869		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 870		cmd->execute_cmd = sbc_execute_rw;
 871		break;
 872	case READ_16:
 873		sectors = transport_get_sectors_16(cdb);
 874		cmd->t_task_lba = transport_lba_64(cdb);
 875
 876		if (sbc_check_dpofua(dev, cmd, cdb))
 877			return TCM_INVALID_CDB_FIELD;
 878
 879		ret = sbc_check_prot(dev, cmd, cdb, sectors, false);
 880		if (ret)
 881			return ret;
 882
 883		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 884		cmd->execute_cmd = sbc_execute_rw;
 885		break;
 886	case WRITE_6:
 887		sectors = transport_get_sectors_6(cdb);
 888		cmd->t_task_lba = transport_lba_21(cdb);
 889		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 890		cmd->execute_cmd = sbc_execute_rw;
 891		break;
 892	case WRITE_10:
 893	case WRITE_VERIFY:
 894		sectors = transport_get_sectors_10(cdb);
 895		cmd->t_task_lba = transport_lba_32(cdb);
 896
 897		if (sbc_check_dpofua(dev, cmd, cdb))
 898			return TCM_INVALID_CDB_FIELD;
 899
 900		ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 901		if (ret)
 902			return ret;
 903
 904		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 905		cmd->execute_cmd = sbc_execute_rw;
 906		break;
 907	case WRITE_12:
 908		sectors = transport_get_sectors_12(cdb);
 909		cmd->t_task_lba = transport_lba_32(cdb);
 910
 911		if (sbc_check_dpofua(dev, cmd, cdb))
 912			return TCM_INVALID_CDB_FIELD;
 913
 914		ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 915		if (ret)
 916			return ret;
 917
 918		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 919		cmd->execute_cmd = sbc_execute_rw;
 920		break;
 921	case WRITE_16:
 922		sectors = transport_get_sectors_16(cdb);
 923		cmd->t_task_lba = transport_lba_64(cdb);
 924
 925		if (sbc_check_dpofua(dev, cmd, cdb))
 926			return TCM_INVALID_CDB_FIELD;
 927
 928		ret = sbc_check_prot(dev, cmd, cdb, sectors, true);
 929		if (ret)
 930			return ret;
 931
 932		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 933		cmd->execute_cmd = sbc_execute_rw;
 934		break;
 935	case XDWRITEREAD_10:
 936		if (cmd->data_direction != DMA_TO_DEVICE ||
 937		    !(cmd->se_cmd_flags & SCF_BIDI))
 938			return TCM_INVALID_CDB_FIELD;
 939		sectors = transport_get_sectors_10(cdb);
 940
 941		if (sbc_check_dpofua(dev, cmd, cdb))
 942			return TCM_INVALID_CDB_FIELD;
 943
 944		cmd->t_task_lba = transport_lba_32(cdb);
 945		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 946
 947		/*
 948		 * Setup BIDI XOR callback to be run after I/O completion.
 949		 */
 950		cmd->execute_cmd = sbc_execute_rw;
 951		cmd->transport_complete_callback = &xdreadwrite_callback;
 952		break;
 953	case VARIABLE_LENGTH_CMD:
 954	{
 955		u16 service_action = get_unaligned_be16(&cdb[8]);
 956		switch (service_action) {
 957		case XDWRITEREAD_32:
 958			sectors = transport_get_sectors_32(cdb);
 959
 960			if (sbc_check_dpofua(dev, cmd, cdb))
 961				return TCM_INVALID_CDB_FIELD;
 962			/*
 963			 * Use WRITE_32 and READ_32 opcodes for the emulated
 964			 * XDWRITE_READ_32 logic.
 965			 */
 966			cmd->t_task_lba = transport_lba_64_ext(cdb);
 967			cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 968
 969			/*
 970			 * Setup BIDI XOR callback to be run during after I/O
 971			 * completion.
 972			 */
 973			cmd->execute_cmd = sbc_execute_rw;
 974			cmd->transport_complete_callback = &xdreadwrite_callback;
 975			break;
 976		case WRITE_SAME_32:
 977			sectors = transport_get_sectors_32(cdb);
 978			if (!sectors) {
 979				pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 980				       " supported\n");
 981				return TCM_INVALID_CDB_FIELD;
 982			}
 983
 984			size = sbc_get_size(cmd, 1);
 985			cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 986
 987			ret = sbc_setup_write_same(cmd, &cdb[10], ops);
 988			if (ret)
 989				return ret;
 990			break;
 991		default:
 992			pr_err("VARIABLE_LENGTH_CMD service action"
 993				" 0x%04x not supported\n", service_action);
 994			return TCM_UNSUPPORTED_SCSI_OPCODE;
 995		}
 996		break;
 997	}
 998	case COMPARE_AND_WRITE:
 999		sectors = cdb[13];
1000		/*
1001		 * Currently enforce COMPARE_AND_WRITE for a single sector
1002		 */
1003		if (sectors > 1) {
1004			pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
1005			       " than 1\n", sectors);
1006			return TCM_INVALID_CDB_FIELD;
1007		}
1008		if (sbc_check_dpofua(dev, cmd, cdb))
1009			return TCM_INVALID_CDB_FIELD;
1010
1011		/*
1012		 * Double size because we have two buffers, note that
1013		 * zero is not an error..
1014		 */
1015		size = 2 * sbc_get_size(cmd, sectors);
1016		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1017		cmd->t_task_nolb = sectors;
1018		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
1019		cmd->execute_cmd = sbc_compare_and_write;
1020		cmd->transport_complete_callback = compare_and_write_callback;
1021		break;
1022	case READ_CAPACITY:
1023		size = READ_CAP_LEN;
1024		cmd->execute_cmd = sbc_emulate_readcapacity;
1025		break;
1026	case SERVICE_ACTION_IN_16:
1027		switch (cmd->t_task_cdb[1] & 0x1f) {
1028		case SAI_READ_CAPACITY_16:
1029			cmd->execute_cmd = sbc_emulate_readcapacity_16;
1030			break;
1031		case SAI_REPORT_REFERRALS:
1032			cmd->execute_cmd = target_emulate_report_referrals;
1033			break;
1034		default:
1035			pr_err("Unsupported SA: 0x%02x\n",
1036				cmd->t_task_cdb[1] & 0x1f);
1037			return TCM_INVALID_CDB_FIELD;
1038		}
1039		size = (cdb[10] << 24) | (cdb[11] << 16) |
1040		       (cdb[12] << 8) | cdb[13];
1041		break;
1042	case SYNCHRONIZE_CACHE:
1043	case SYNCHRONIZE_CACHE_16:
1044		if (cdb[0] == SYNCHRONIZE_CACHE) {
1045			sectors = transport_get_sectors_10(cdb);
1046			cmd->t_task_lba = transport_lba_32(cdb);
1047		} else {
1048			sectors = transport_get_sectors_16(cdb);
1049			cmd->t_task_lba = transport_lba_64(cdb);
1050		}
1051		if (ops->execute_sync_cache) {
1052			cmd->execute_cmd = ops->execute_sync_cache;
1053			goto check_lba;
1054		}
1055		size = 0;
1056		cmd->execute_cmd = sbc_emulate_noop;
1057		break;
1058	case UNMAP:
1059		if (!ops->execute_unmap)
1060			return TCM_UNSUPPORTED_SCSI_OPCODE;
1061
1062		if (!dev->dev_attrib.emulate_tpu) {
1063			pr_err("Got UNMAP, but backend device has"
1064			       " emulate_tpu disabled\n");
1065			return TCM_UNSUPPORTED_SCSI_OPCODE;
1066		}
1067		size = get_unaligned_be16(&cdb[7]);
1068		cmd->execute_cmd = sbc_execute_unmap;
1069		break;
1070	case WRITE_SAME_16:
1071		sectors = transport_get_sectors_16(cdb);
1072		if (!sectors) {
1073			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1074			return TCM_INVALID_CDB_FIELD;
1075		}
1076
1077		size = sbc_get_size(cmd, 1);
1078		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1079
1080		ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1081		if (ret)
1082			return ret;
1083		break;
1084	case WRITE_SAME:
1085		sectors = transport_get_sectors_10(cdb);
1086		if (!sectors) {
1087			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1088			return TCM_INVALID_CDB_FIELD;
1089		}
1090
1091		size = sbc_get_size(cmd, 1);
1092		cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1093
1094		/*
1095		 * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1096		 * of byte 1 bit 3 UNMAP instead of original reserved field
1097		 */
1098		ret = sbc_setup_write_same(cmd, &cdb[1], ops);
1099		if (ret)
1100			return ret;
1101		break;
1102	case VERIFY:
1103		size = 0;
1104		sectors = transport_get_sectors_10(cdb);
1105		cmd->t_task_lba = transport_lba_32(cdb);
1106		cmd->execute_cmd = sbc_emulate_noop;
1107		goto check_lba;
1108	case REZERO_UNIT:
1109	case SEEK_6:
1110	case SEEK_10:
1111		/*
1112		 * There are still clients out there which use these old SCSI-2
1113		 * commands. This mainly happens when running VMs with legacy
1114		 * guest systems, connected via SCSI command pass-through to
1115		 * iSCSI targets. Make them happy and return status GOOD.
1116		 */
1117		size = 0;
1118		cmd->execute_cmd = sbc_emulate_noop;
1119		break;
1120	case START_STOP:
1121		size = 0;
1122		cmd->execute_cmd = sbc_emulate_startstop;
1123		break;
1124	default:
1125		ret = spc_parse_cdb(cmd, &size);
1126		if (ret)
1127			return ret;
1128	}
1129
1130	/* reject any command that we don't have a handler for */
1131	if (!cmd->execute_cmd)
1132		return TCM_UNSUPPORTED_SCSI_OPCODE;
1133
1134	if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1135		unsigned long long end_lba;
1136check_lba:
1137		end_lba = dev->transport->get_blocks(dev) + 1;
1138		if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1139		    ((cmd->t_task_lba + sectors) > end_lba)) {
1140			pr_err("cmd exceeds last lba %llu "
1141				"(lba %llu, sectors %u)\n",
1142				end_lba, cmd->t_task_lba, sectors);
1143			return TCM_ADDRESS_OUT_OF_RANGE;
1144		}
1145
1146		if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1147			size = sbc_get_size(cmd, sectors);
1148	}
1149
1150	return target_cmd_size_check(cmd, size);
1151}
1152EXPORT_SYMBOL(sbc_parse_cdb);
1153
1154u32 sbc_get_device_type(struct se_device *dev)
1155{
1156	return TYPE_DISK;
1157}
1158EXPORT_SYMBOL(sbc_get_device_type);
1159
1160static sense_reason_t
1161sbc_execute_unmap(struct se_cmd *cmd)
1162{
1163	struct sbc_ops *ops = cmd->protocol_data;
1164	struct se_device *dev = cmd->se_dev;
1165	unsigned char *buf, *ptr = NULL;
1166	sector_t lba;
1167	int size;
1168	u32 range;
1169	sense_reason_t ret = 0;
1170	int dl, bd_dl;
1171
1172	/* We never set ANC_SUP */
1173	if (cmd->t_task_cdb[1])
1174		return TCM_INVALID_CDB_FIELD;
1175
1176	if (cmd->data_length == 0) {
1177		target_complete_cmd(cmd, SAM_STAT_GOOD);
1178		return 0;
1179	}
1180
1181	if (cmd->data_length < 8) {
1182		pr_warn("UNMAP parameter list length %u too small\n",
1183			cmd->data_length);
1184		return TCM_PARAMETER_LIST_LENGTH_ERROR;
1185	}
1186
1187	buf = transport_kmap_data_sg(cmd);
1188	if (!buf)
1189		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1190
1191	dl = get_unaligned_be16(&buf[0]);
1192	bd_dl = get_unaligned_be16(&buf[2]);
1193
1194	size = cmd->data_length - 8;
1195	if (bd_dl > size)
1196		pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1197			cmd->data_length, bd_dl);
1198	else
1199		size = bd_dl;
1200
1201	if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1202		ret = TCM_INVALID_PARAMETER_LIST;
1203		goto err;
1204	}
1205
1206	/* First UNMAP block descriptor starts at 8 byte offset */
1207	ptr = &buf[8];
1208	pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1209		" ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1210
1211	while (size >= 16) {
1212		lba = get_unaligned_be64(&ptr[0]);
1213		range = get_unaligned_be32(&ptr[8]);
1214		pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1215				 (unsigned long long)lba, range);
1216
1217		if (range > dev->dev_attrib.max_unmap_lba_count) {
1218			ret = TCM_INVALID_PARAMETER_LIST;
1219			goto err;
1220		}
1221
1222		if (lba + range > dev->transport->get_blocks(dev) + 1) {
1223			ret = TCM_ADDRESS_OUT_OF_RANGE;
1224			goto err;
1225		}
1226
1227		ret = ops->execute_unmap(cmd, lba, range);
1228		if (ret)
1229			goto err;
1230
1231		ptr += 16;
1232		size -= 16;
1233	}
1234
1235err:
1236	transport_kunmap_data_sg(cmd);
1237	if (!ret)
1238		target_complete_cmd(cmd, GOOD);
1239	return ret;
1240}
1241
1242void
1243sbc_dif_generate(struct se_cmd *cmd)
1244{
1245	struct se_device *dev = cmd->se_dev;
1246	struct t10_pi_tuple *sdt;
1247	struct scatterlist *dsg = cmd->t_data_sg, *psg;
1248	sector_t sector = cmd->t_task_lba;
1249	void *daddr, *paddr;
1250	int i, j, offset = 0;
1251	unsigned int block_size = dev->dev_attrib.block_size;
1252
1253	for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1254		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1255		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1256
1257		for (j = 0; j < psg->length;
1258				j += sizeof(*sdt)) {
1259			__u16 crc;
1260			unsigned int avail;
1261
1262			if (offset >= dsg->length) {
1263				offset -= dsg->length;
1264				kunmap_atomic(daddr - dsg->offset);
1265				dsg = sg_next(dsg);
1266				if (!dsg) {
1267					kunmap_atomic(paddr - psg->offset);
1268					return;
1269				}
1270				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1271			}
1272
1273			sdt = paddr + j;
1274			avail = min(block_size, dsg->length - offset);
1275			crc = crc_t10dif(daddr + offset, avail);
1276			if (avail < block_size) {
1277				kunmap_atomic(daddr - dsg->offset);
1278				dsg = sg_next(dsg);
1279				if (!dsg) {
1280					kunmap_atomic(paddr - psg->offset);
1281					return;
1282				}
1283				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1284				offset = block_size - avail;
1285				crc = crc_t10dif_update(crc, daddr, offset);
1286			} else {
1287				offset += block_size;
1288			}
1289
1290			sdt->guard_tag = cpu_to_be16(crc);
1291			if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1292				sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1293			sdt->app_tag = 0;
1294
1295			pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1296				 " app_tag: 0x%04x ref_tag: %u\n",
1297				 (cmd->data_direction == DMA_TO_DEVICE) ?
1298				 "WRITE" : "READ", (unsigned long long)sector,
1299				 sdt->guard_tag, sdt->app_tag,
1300				 be32_to_cpu(sdt->ref_tag));
1301
1302			sector++;
1303		}
1304
1305		kunmap_atomic(daddr - dsg->offset);
1306		kunmap_atomic(paddr - psg->offset);
1307	}
1308}
1309
1310static sense_reason_t
1311sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
1312		  __u16 crc, sector_t sector, unsigned int ei_lba)
1313{
1314	__be16 csum;
1315
1316	if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1317		goto check_ref;
1318
1319	csum = cpu_to_be16(crc);
1320
1321	if (sdt->guard_tag != csum) {
1322		pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1323			" csum 0x%04x\n", (unsigned long long)sector,
1324			be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1325		return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1326	}
1327
1328check_ref:
1329	if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1330		return 0;
1331
1332	if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1333	    be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1334		pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1335		       " sector MSB: 0x%08x\n", (unsigned long long)sector,
1336		       be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1337		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1338	}
1339
1340	if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1341	    be32_to_cpu(sdt->ref_tag) != ei_lba) {
1342		pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1343		       " ei_lba: 0x%08x\n", (unsigned long long)sector,
1344			be32_to_cpu(sdt->ref_tag), ei_lba);
1345		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1346	}
1347
1348	return 0;
1349}
1350
1351void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1352		       struct scatterlist *sg, int sg_off)
1353{
1354	struct se_device *dev = cmd->se_dev;
1355	struct scatterlist *psg;
1356	void *paddr, *addr;
1357	unsigned int i, len, left;
1358	unsigned int offset = sg_off;
1359
1360	if (!sg)
1361		return;
1362
1363	left = sectors * dev->prot_length;
1364
1365	for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1366		unsigned int psg_len, copied = 0;
1367
1368		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1369		psg_len = min(left, psg->length);
1370		while (psg_len) {
1371			len = min(psg_len, sg->length - offset);
1372			addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1373
1374			if (read)
1375				memcpy(paddr + copied, addr, len);
1376			else
1377				memcpy(addr, paddr + copied, len);
1378
1379			left -= len;
1380			offset += len;
1381			copied += len;
1382			psg_len -= len;
1383
1384			kunmap_atomic(addr - sg->offset - offset);
1385
1386			if (offset >= sg->length) {
1387				sg = sg_next(sg);
1388				offset = 0;
1389			}
1390		}
1391		kunmap_atomic(paddr - psg->offset);
1392	}
1393}
1394EXPORT_SYMBOL(sbc_dif_copy_prot);
1395
1396sense_reason_t
1397sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1398	       unsigned int ei_lba, struct scatterlist *psg, int psg_off)
1399{
1400	struct se_device *dev = cmd->se_dev;
1401	struct t10_pi_tuple *sdt;
1402	struct scatterlist *dsg = cmd->t_data_sg;
1403	sector_t sector = start;
1404	void *daddr, *paddr;
1405	int i;
1406	sense_reason_t rc;
1407	int dsg_off = 0;
1408	unsigned int block_size = dev->dev_attrib.block_size;
1409
1410	for (; psg && sector < start + sectors; psg = sg_next(psg)) {
1411		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1412		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1413
1414		for (i = psg_off; i < psg->length &&
1415				sector < start + sectors;
1416				i += sizeof(*sdt)) {
1417			__u16 crc;
1418			unsigned int avail;
1419
1420			if (dsg_off >= dsg->length) {
1421				dsg_off -= dsg->length;
1422				kunmap_atomic(daddr - dsg->offset);
1423				dsg = sg_next(dsg);
1424				if (!dsg) {
1425					kunmap_atomic(paddr - psg->offset);
1426					return 0;
1427				}
1428				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1429			}
1430
1431			sdt = paddr + i;
1432
1433			pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1434				 " app_tag: 0x%04x ref_tag: %u\n",
1435				 (unsigned long long)sector, sdt->guard_tag,
1436				 sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1437
1438			if (sdt->app_tag == cpu_to_be16(0xffff)) {
1439				dsg_off += block_size;
1440				goto next;
1441			}
1442
1443			avail = min(block_size, dsg->length - dsg_off);
1444			crc = crc_t10dif(daddr + dsg_off, avail);
1445			if (avail < block_size) {
1446				kunmap_atomic(daddr - dsg->offset);
1447				dsg = sg_next(dsg);
1448				if (!dsg) {
1449					kunmap_atomic(paddr - psg->offset);
1450					return 0;
1451				}
1452				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1453				dsg_off = block_size - avail;
1454				crc = crc_t10dif_update(crc, daddr, dsg_off);
1455			} else {
1456				dsg_off += block_size;
1457			}
1458
1459			rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
1460			if (rc) {
1461				kunmap_atomic(daddr - dsg->offset);
1462				kunmap_atomic(paddr - psg->offset);
1463				cmd->bad_sector = sector;
1464				return rc;
1465			}
1466next:
1467			sector++;
1468			ei_lba++;
1469		}
1470
1471		psg_off = 0;
1472		kunmap_atomic(daddr - dsg->offset);
1473		kunmap_atomic(paddr - psg->offset);
1474	}
1475
1476	return 0;
1477}
1478EXPORT_SYMBOL(sbc_dif_verify);