target_core_sbc.c

   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * SCSI Block Commands (SBC) parsing and emulation.
   4 *
   5 * (c) Copyright 2002-2013 Datera, Inc.
   6 *
   7 * Nicholas A. Bellinger <nab@kernel.org>
   8 */
   9
  10#include <linux/kernel.h>
  11#include <linux/module.h>
  12#include <linux/ratelimit.h>
  13#include <linux/crc-t10dif.h>
  14#include <linux/t10-pi.h>
  15#include <linux/unaligned.h>
  16#include <scsi/scsi_proto.h>
  17#include <scsi/scsi_tcq.h>
  18
  19#include <target/target_core_base.h>
  20#include <target/target_core_backend.h>
  21#include <target/target_core_fabric.h>
  22
  23#include "target_core_internal.h"
  24#include "target_core_ua.h"
  25#include "target_core_alua.h"
  26
  27static sense_reason_t
  28sbc_check_prot(struct se_device *, struct se_cmd *, unsigned char, u32, bool);
  29static sense_reason_t sbc_execute_unmap(struct se_cmd *cmd);
  30
  31static sense_reason_t
  32sbc_emulate_readcapacity(struct se_cmd *cmd)
  33{
  34	struct se_device *dev = cmd->se_dev;
  35	unsigned char *cdb = cmd->t_task_cdb;
  36	unsigned long long blocks_long = dev->transport->get_blocks(dev);
  37	unsigned char *rbuf;
  38	unsigned char buf[8];
  39	u32 blocks;
  40
  41	/*
  42	 * SBC-2 says:
  43	 *   If the PMI bit is set to zero and the LOGICAL BLOCK
  44	 *   ADDRESS field is not set to zero, the device server shall
  45	 *   terminate the command with CHECK CONDITION status with
  46	 *   the sense key set to ILLEGAL REQUEST and the additional
  47	 *   sense code set to INVALID FIELD IN CDB.
  48	 *
  49	 * In SBC-3, these fields are obsolete, but some SCSI
  50	 * compliance tests actually check this, so we might as well
  51	 * follow SBC-2.
  52	 */
  53	if (!(cdb[8] & 1) && !!(cdb[2] | cdb[3] | cdb[4] | cdb[5]))
  54		return TCM_INVALID_CDB_FIELD;
  55
  56	if (blocks_long >= 0x00000000ffffffff)
  57		blocks = 0xffffffff;
  58	else
  59		blocks = (u32)blocks_long;
  60
  61	put_unaligned_be32(blocks, &buf[0]);
  62	put_unaligned_be32(dev->dev_attrib.block_size, &buf[4]);
  63
  64	rbuf = transport_kmap_data_sg(cmd);
  65	if (rbuf) {
  66		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
  67		transport_kunmap_data_sg(cmd);
  68	}
  69
  70	target_complete_cmd_with_length(cmd, SAM_STAT_GOOD, 8);
  71	return 0;
  72}
  73
  74static sense_reason_t
  75sbc_emulate_readcapacity_16(struct se_cmd *cmd)
  76{
  77	struct se_device *dev = cmd->se_dev;
  78	struct se_session *sess = cmd->se_sess;
  79	int pi_prot_type = dev->dev_attrib.pi_prot_type;
  80
  81	unsigned char *rbuf;
  82	unsigned char buf[32];
  83	unsigned long long blocks = dev->transport->get_blocks(dev);
  84
  85	memset(buf, 0, sizeof(buf));
  86	put_unaligned_be64(blocks, &buf[0]);
  87	put_unaligned_be32(dev->dev_attrib.block_size, &buf[8]);
  88	/*
  89	 * Set P_TYPE and PROT_EN bits for DIF support
  90	 */
  91	if (sess->sup_prot_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DOUT_PASS)) {
  92		/*
  93		 * Only override a device's pi_prot_type if no T10-PI is
  94		 * available, and sess_prot_type has been explicitly enabled.
  95		 */
  96		if (!pi_prot_type)
  97			pi_prot_type = sess->sess_prot_type;
  98
  99		if (pi_prot_type)
 100			buf[12] = (pi_prot_type - 1) << 1 | 0x1;
 101	}
 102
 103	if (dev->transport->get_lbppbe)
 104		buf[13] = dev->transport->get_lbppbe(dev) & 0x0f;
 105
 106	if (dev->transport->get_alignment_offset_lbas) {
 107		u16 lalba = dev->transport->get_alignment_offset_lbas(dev);
 108
 109		put_unaligned_be16(lalba, &buf[14]);
 110	}
 111
 112	/*
 113	 * Set Thin Provisioning Enable bit following sbc3r22 in section
 114	 * READ CAPACITY (16) byte 14 if emulate_tpu or emulate_tpws is enabled.
 115	 */
 116	if (dev->dev_attrib.emulate_tpu || dev->dev_attrib.emulate_tpws) {
 117		buf[14] |= 0x80;
 118
 119		/*
 120		 * LBPRZ signifies that zeroes will be read back from an LBA after
 121		 * an UNMAP or WRITE SAME w/ unmap bit (sbc3r36 5.16.2)
 122		 */
 123		if (dev->dev_attrib.unmap_zeroes_data)
 124			buf[14] |= 0x40;
 125	}
 126
 127	rbuf = transport_kmap_data_sg(cmd);
 128	if (rbuf) {
 129		memcpy(rbuf, buf, min_t(u32, sizeof(buf), cmd->data_length));
 130		transport_kunmap_data_sg(cmd);
 131	}
 132
 133	target_complete_cmd_with_length(cmd, SAM_STAT_GOOD, 32);
 134	return 0;
 135}
 136
 137static sense_reason_t
 138sbc_emulate_startstop(struct se_cmd *cmd)
 139{
 140	unsigned char *cdb = cmd->t_task_cdb;
 141
 142	/*
 143	 * See sbc3r36 section 5.25
 144	 * Immediate bit should be set since there is nothing to complete
 145	 * POWER CONDITION MODIFIER 0h
 146	 */
 147	if (!(cdb[1] & 1) || cdb[2] || cdb[3])
 148		return TCM_INVALID_CDB_FIELD;
 149
 150	/*
 151	 * See sbc3r36 section 5.25
 152	 * POWER CONDITION 0h START_VALID - process START and LOEJ
 153	 */
 154	if (cdb[4] >> 4 & 0xf)
 155		return TCM_INVALID_CDB_FIELD;
 156
 157	/*
 158	 * See sbc3r36 section 5.25
 159	 * LOEJ 0h - nothing to load or unload
 160	 * START 1h - we are ready
 161	 */
 162	if (!(cdb[4] & 1) || (cdb[4] & 2) || (cdb[4] & 4))
 163		return TCM_INVALID_CDB_FIELD;
 164
 165	target_complete_cmd(cmd, SAM_STAT_GOOD);
 166	return 0;
 167}
 168
 169sector_t sbc_get_write_same_sectors(struct se_cmd *cmd)
 170{
 171	u32 num_blocks;
 172
 173	if (cmd->t_task_cdb[0] == WRITE_SAME)
 174		num_blocks = get_unaligned_be16(&cmd->t_task_cdb[7]);
 175	else if (cmd->t_task_cdb[0] == WRITE_SAME_16)
 176		num_blocks = get_unaligned_be32(&cmd->t_task_cdb[10]);
 177	else /* WRITE_SAME_32 via VARIABLE_LENGTH_CMD */
 178		num_blocks = get_unaligned_be32(&cmd->t_task_cdb[28]);
 179
 180	/*
 181	 * Use the explicit range when non zero is supplied, otherwise calculate
 182	 * the remaining range based on ->get_blocks() - starting LBA.
 183	 */
 184	if (num_blocks)
 185		return num_blocks;
 186
 187	return cmd->se_dev->transport->get_blocks(cmd->se_dev) -
 188		cmd->t_task_lba + 1;
 189}
 190EXPORT_SYMBOL(sbc_get_write_same_sectors);
 191
 192static sense_reason_t
 193sbc_execute_write_same_unmap(struct se_cmd *cmd)
 194{
 195	struct exec_cmd_ops *ops = cmd->protocol_data;
 196	sector_t nolb = sbc_get_write_same_sectors(cmd);
 197	sense_reason_t ret;
 198
 199	if (nolb) {
 200		ret = ops->execute_unmap(cmd, cmd->t_task_lba, nolb);
 201		if (ret)
 202			return ret;
 203	}
 204
 205	target_complete_cmd(cmd, SAM_STAT_GOOD);
 206	return 0;
 207}
 208
 209static sense_reason_t
 210sbc_emulate_noop(struct se_cmd *cmd)
 211{
 212	target_complete_cmd(cmd, SAM_STAT_GOOD);
 213	return 0;
 214}
 215
 216static inline u32 sbc_get_size(struct se_cmd *cmd, u32 sectors)
 217{
 218	return cmd->se_dev->dev_attrib.block_size * sectors;
 219}
 220
 221static inline u32 transport_get_sectors_6(unsigned char *cdb)
 222{
 223	/*
 224	 * Use 8-bit sector value.  SBC-3 says:
 225	 *
 226	 *   A TRANSFER LENGTH field set to zero specifies that 256
 227	 *   logical blocks shall be written.  Any other value
 228	 *   specifies the number of logical blocks that shall be
 229	 *   written.
 230	 */
 231	return cdb[4] ? : 256;
 232}
 233
 234static inline u32 transport_get_sectors_10(unsigned char *cdb)
 235{
 236	return get_unaligned_be16(&cdb[7]);
 237}
 238
 239static inline u32 transport_get_sectors_12(unsigned char *cdb)
 240{
 241	return get_unaligned_be32(&cdb[6]);
 242}
 243
 244static inline u32 transport_get_sectors_16(unsigned char *cdb)
 245{
 246	return get_unaligned_be32(&cdb[10]);
 247}
 248
 249/*
 250 * Used for VARIABLE_LENGTH_CDB WRITE_32 and READ_32 variants
 251 */
 252static inline u32 transport_get_sectors_32(unsigned char *cdb)
 253{
 254	return get_unaligned_be32(&cdb[28]);
 255
 256}
 257
 258static inline u32 transport_lba_21(unsigned char *cdb)
 259{
 260	return get_unaligned_be24(&cdb[1]) & 0x1fffff;
 261}
 262
 263static inline u32 transport_lba_32(unsigned char *cdb)
 264{
 265	return get_unaligned_be32(&cdb[2]);
 266}
 267
 268static inline unsigned long long transport_lba_64(unsigned char *cdb)
 269{
 270	return get_unaligned_be64(&cdb[2]);
 271}
 272
 273static sense_reason_t
 274sbc_setup_write_same(struct se_cmd *cmd, unsigned char flags,
 275		     struct exec_cmd_ops *ops)
 276{
 277	struct se_device *dev = cmd->se_dev;
 278	sector_t end_lba = dev->transport->get_blocks(dev) + 1;
 279	unsigned int sectors = sbc_get_write_same_sectors(cmd);
 280	sense_reason_t ret;
 281
 282	if ((flags & 0x04) || (flags & 0x02)) {
 283		pr_err("WRITE_SAME PBDATA and LBDATA"
 284			" bits not supported for Block Discard"
 285			" Emulation\n");
 286		return TCM_UNSUPPORTED_SCSI_OPCODE;
 287	}
 288	if (sectors > cmd->se_dev->dev_attrib.max_write_same_len) {
 289		pr_warn("WRITE_SAME sectors: %u exceeds max_write_same_len: %u\n",
 290			sectors, cmd->se_dev->dev_attrib.max_write_same_len);
 291		return TCM_INVALID_CDB_FIELD;
 292	}
 293	/*
 294	 * Sanity check for LBA wrap and request past end of device.
 295	 */
 296	if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
 297	    ((cmd->t_task_lba + sectors) > end_lba)) {
 298		pr_err("WRITE_SAME exceeds last lba %llu (lba %llu, sectors %u)\n",
 299		       (unsigned long long)end_lba, cmd->t_task_lba, sectors);
 300		return TCM_ADDRESS_OUT_OF_RANGE;
 301	}
 302
 303	/* We always have ANC_SUP == 0 so setting ANCHOR is always an error */
 304	if (flags & 0x10) {
 305		pr_warn("WRITE SAME with ANCHOR not supported\n");
 306		return TCM_INVALID_CDB_FIELD;
 307	}
 308
 309	if (flags & 0x01) {
 310		pr_warn("WRITE SAME with NDOB not supported\n");
 311		return TCM_INVALID_CDB_FIELD;
 312	}
 313
 314	/*
 315	 * Special case for WRITE_SAME w/ UNMAP=1 that ends up getting
 316	 * translated into block discard requests within backend code.
 317	 */
 318	if (flags & 0x08) {
 319		if (!ops->execute_unmap)
 320			return TCM_UNSUPPORTED_SCSI_OPCODE;
 321
 322		if (!dev->dev_attrib.emulate_tpws) {
 323			pr_err("Got WRITE_SAME w/ UNMAP=1, but backend device"
 324			       " has emulate_tpws disabled\n");
 325			return TCM_UNSUPPORTED_SCSI_OPCODE;
 326		}
 327		cmd->execute_cmd = sbc_execute_write_same_unmap;
 328		return 0;
 329	}
 330	if (!ops->execute_write_same)
 331		return TCM_UNSUPPORTED_SCSI_OPCODE;
 332
 333	ret = sbc_check_prot(dev, cmd, flags >> 5, sectors, true);
 334	if (ret)
 335		return ret;
 336
 337	cmd->execute_cmd = ops->execute_write_same;
 338	return 0;
 339}
 340
 341static sense_reason_t
 342sbc_execute_rw(struct se_cmd *cmd)
 343{
 344	struct exec_cmd_ops *ops = cmd->protocol_data;
 345
 346	return ops->execute_rw(cmd, cmd->t_data_sg, cmd->t_data_nents,
 347			       cmd->data_direction);
 348}
 349
 350static sense_reason_t compare_and_write_post(struct se_cmd *cmd, bool success,
 351					     int *post_ret)
 352{
 353	struct se_device *dev = cmd->se_dev;
 354	sense_reason_t ret = TCM_NO_SENSE;
 355
 356	spin_lock_irq(&cmd->t_state_lock);
 357	if (success) {
 358		*post_ret = 1;
 359
 360		if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
 361			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 362	}
 363	spin_unlock_irq(&cmd->t_state_lock);
 364
 365	/*
 366	 * Unlock ->caw_sem originally obtained during sbc_compare_and_write()
 367	 * before the original READ I/O submission.
 368	 */
 369	up(&dev->caw_sem);
 370
 371	return ret;
 372}
 373
 374/*
 375 * compare @cmp_len bytes of @read_sgl with @cmp_sgl. On miscompare, fill
 376 * @miscmp_off and return TCM_MISCOMPARE_VERIFY.
 377 */
 378static sense_reason_t
 379compare_and_write_do_cmp(struct scatterlist *read_sgl, unsigned int read_nents,
 380			 struct scatterlist *cmp_sgl, unsigned int cmp_nents,
 381			 unsigned int cmp_len, unsigned int *miscmp_off)
 382{
 383	unsigned char *buf = NULL;
 384	struct scatterlist *sg;
 385	sense_reason_t ret;
 386	unsigned int offset;
 387	size_t rc;
 388	int sg_cnt;
 389
 390	buf = kzalloc(cmp_len, GFP_KERNEL);
 391	if (!buf) {
 392		ret = TCM_OUT_OF_RESOURCES;
 393		goto out;
 394	}
 395
 396	rc = sg_copy_to_buffer(cmp_sgl, cmp_nents, buf, cmp_len);
 397	if (!rc) {
 398		pr_err("sg_copy_to_buffer() failed for compare_and_write\n");
 399		ret = TCM_OUT_OF_RESOURCES;
 400		goto out;
 401	}
 402	/*
 403	 * Compare SCSI READ payload against verify payload
 404	 */
 405	offset = 0;
 406	ret = TCM_NO_SENSE;
 407	for_each_sg(read_sgl, sg, read_nents, sg_cnt) {
 408		unsigned int len = min(sg->length, cmp_len);
 409		unsigned char *addr = kmap_atomic(sg_page(sg));
 410
 411		if (memcmp(addr, buf + offset, len)) {
 412			unsigned int i;
 413
 414			for (i = 0; i < len && addr[i] == buf[offset + i]; i++)
 415				;
 416			*miscmp_off = offset + i;
 417			pr_warn("Detected MISCOMPARE at offset %u\n",
 418				*miscmp_off);
 419			ret = TCM_MISCOMPARE_VERIFY;
 420		}
 421		kunmap_atomic(addr);
 422		if (ret != TCM_NO_SENSE)
 423			goto out;
 424
 425		offset += len;
 426		cmp_len -= len;
 427		if (!cmp_len)
 428			break;
 429	}
 430	pr_debug("COMPARE AND WRITE read data matches compare data\n");
 431out:
 432	kfree(buf);
 433	return ret;
 434}
 435
 436static sense_reason_t compare_and_write_callback(struct se_cmd *cmd, bool success,
 437						 int *post_ret)
 438{
 439	struct se_device *dev = cmd->se_dev;
 440	struct sg_table write_tbl = { };
 441	struct scatterlist *write_sg;
 442	struct sg_mapping_iter m;
 443	unsigned int len;
 444	unsigned int block_size = dev->dev_attrib.block_size;
 445	unsigned int compare_len = (cmd->t_task_nolb * block_size);
 446	unsigned int miscmp_off = 0;
 447	sense_reason_t ret = TCM_NO_SENSE;
 448	int i;
 449
 450	if (!success) {
 451		/*
 452		 * Handle early failure in transport_generic_request_failure(),
 453		 * which will not have taken ->caw_sem yet..
 454		 */
 455		if (!cmd->t_data_sg || !cmd->t_bidi_data_sg)
 456			return TCM_NO_SENSE;
 457
 458		/*
 459		 * The command has been stopped or aborted so
 460		 * we don't have to perform the write operation.
 461		 */
 462		WARN_ON(!(cmd->transport_state &
 463			(CMD_T_ABORTED | CMD_T_STOP)));
 464		goto out;
 465	}
 466	/*
 467	 * Handle special case for zero-length COMPARE_AND_WRITE
 468	 */
 469	if (!cmd->data_length)
 470		goto out;
 471	/*
 472	 * Immediately exit + release dev->caw_sem if command has already
 473	 * been failed with a non-zero SCSI status.
 474	 */
 475	if (cmd->scsi_status) {
 476		pr_debug("compare_and_write_callback: non zero scsi_status:"
 477			" 0x%02x\n", cmd->scsi_status);
 478		*post_ret = 1;
 479		if (cmd->scsi_status == SAM_STAT_CHECK_CONDITION)
 480			ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 481		goto out;
 482	}
 483
 484	ret = compare_and_write_do_cmp(cmd->t_bidi_data_sg,
 485				       cmd->t_bidi_data_nents,
 486				       cmd->t_data_sg,
 487				       cmd->t_data_nents,
 488				       compare_len,
 489				       &miscmp_off);
 490	if (ret == TCM_MISCOMPARE_VERIFY) {
 491		/*
 492		 * SBC-4 r15: 5.3 COMPARE AND WRITE command
 493		 * In the sense data (see 4.18 and SPC-5) the offset from the
 494		 * start of the Data-Out Buffer to the first byte of data that
 495		 * was not equal shall be reported in the INFORMATION field.
 496		 */
 497		cmd->sense_info = miscmp_off;
 498		goto out;
 499	} else if (ret)
 500		goto out;
 501
 502	if (sg_alloc_table(&write_tbl, cmd->t_data_nents, GFP_KERNEL) < 0) {
 503		pr_err("Unable to allocate compare_and_write sg\n");
 504		ret = TCM_OUT_OF_RESOURCES;
 505		goto out;
 506	}
 507	write_sg = write_tbl.sgl;
 508
 509	i = 0;
 510	len = compare_len;
 511	sg_miter_start(&m, cmd->t_data_sg, cmd->t_data_nents, SG_MITER_TO_SG);
 512	/*
 513	 * Currently assumes NoLB=1 and SGLs are PAGE_SIZE..
 514	 */
 515	while (len) {
 516		sg_miter_next(&m);
 517
 518		if (block_size < PAGE_SIZE) {
 519			sg_set_page(&write_sg[i], m.page, block_size,
 520				    m.piter.sg->offset + block_size);
 521		} else {
 522			sg_miter_next(&m);
 523			sg_set_page(&write_sg[i], m.page, block_size,
 524				    m.piter.sg->offset);
 525		}
 526		len -= block_size;
 527		i++;
 528	}
 529	sg_miter_stop(&m);
 530	/*
 531	 * Save the original SGL + nents values before updating to new
 532	 * assignments, to be released in transport_free_pages() ->
 533	 * transport_reset_sgl_orig()
 534	 */
 535	cmd->t_data_sg_orig = cmd->t_data_sg;
 536	cmd->t_data_sg = write_sg;
 537	cmd->t_data_nents_orig = cmd->t_data_nents;
 538	cmd->t_data_nents = 1;
 539
 540	cmd->sam_task_attr = TCM_HEAD_TAG;
 541	cmd->transport_complete_callback = compare_and_write_post;
 542	/*
 543	 * Now reset ->execute_cmd() to the normal sbc_execute_rw() handler
 544	 * for submitting the adjusted SGL to write instance user-data.
 545	 */
 546	cmd->execute_cmd = sbc_execute_rw;
 547
 548	spin_lock_irq(&cmd->t_state_lock);
 549	cmd->t_state = TRANSPORT_PROCESSING;
 550	cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
 551	spin_unlock_irq(&cmd->t_state_lock);
 552
 553	__target_execute_cmd(cmd, false);
 554
 555	return ret;
 556
 557out:
 558	/*
 559	 * In the MISCOMPARE or failure case, unlock ->caw_sem obtained in
 560	 * sbc_compare_and_write() before the original READ I/O submission.
 561	 */
 562	up(&dev->caw_sem);
 563	sg_free_table(&write_tbl);
 564	return ret;
 565}
 566
 567static sense_reason_t
 568sbc_compare_and_write(struct se_cmd *cmd)
 569{
 570	struct exec_cmd_ops *ops = cmd->protocol_data;
 571	struct se_device *dev = cmd->se_dev;
 572	sense_reason_t ret;
 573	int rc;
 574	/*
 575	 * Submit the READ first for COMPARE_AND_WRITE to perform the
 576	 * comparision using SGLs at cmd->t_bidi_data_sg..
 577	 */
 578	rc = down_interruptible(&dev->caw_sem);
 579	if (rc != 0) {
 580		cmd->transport_complete_callback = NULL;
 581		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 582	}
 583	/*
 584	 * Reset cmd->data_length to individual block_size in order to not
 585	 * confuse backend drivers that depend on this value matching the
 586	 * size of the I/O being submitted.
 587	 */
 588	cmd->data_length = cmd->t_task_nolb * dev->dev_attrib.block_size;
 589
 590	ret = ops->execute_rw(cmd, cmd->t_bidi_data_sg, cmd->t_bidi_data_nents,
 591			      DMA_FROM_DEVICE);
 592	if (ret) {
 593		cmd->transport_complete_callback = NULL;
 594		up(&dev->caw_sem);
 595		return ret;
 596	}
 597	/*
 598	 * Unlock of dev->caw_sem to occur in compare_and_write_callback()
 599	 * upon MISCOMPARE, or in compare_and_write_done() upon completion
 600	 * of WRITE instance user-data.
 601	 */
 602	return TCM_NO_SENSE;
 603}
 604
 605static int
 606sbc_set_prot_op_checks(u8 protect, bool fabric_prot, enum target_prot_type prot_type,
 607		       bool is_write, struct se_cmd *cmd)
 608{
 609	if (is_write) {
 610		cmd->prot_op = fabric_prot ? TARGET_PROT_DOUT_STRIP :
 611			       protect ? TARGET_PROT_DOUT_PASS :
 612			       TARGET_PROT_DOUT_INSERT;
 613		switch (protect) {
 614		case 0x0:
 615		case 0x3:
 616			cmd->prot_checks = 0;
 617			break;
 618		case 0x1:
 619		case 0x5:
 620			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 621			if (prot_type == TARGET_DIF_TYPE1_PROT)
 622				cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 623			break;
 624		case 0x2:
 625			if (prot_type == TARGET_DIF_TYPE1_PROT)
 626				cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 627			break;
 628		case 0x4:
 629			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 630			break;
 631		default:
 632			pr_err("Unsupported protect field %d\n", protect);
 633			return -EINVAL;
 634		}
 635	} else {
 636		cmd->prot_op = fabric_prot ? TARGET_PROT_DIN_INSERT :
 637			       protect ? TARGET_PROT_DIN_PASS :
 638			       TARGET_PROT_DIN_STRIP;
 639		switch (protect) {
 640		case 0x0:
 641		case 0x1:
 642		case 0x5:
 643			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 644			if (prot_type == TARGET_DIF_TYPE1_PROT)
 645				cmd->prot_checks |= TARGET_DIF_CHECK_REFTAG;
 646			break;
 647		case 0x2:
 648			if (prot_type == TARGET_DIF_TYPE1_PROT)
 649				cmd->prot_checks = TARGET_DIF_CHECK_REFTAG;
 650			break;
 651		case 0x3:
 652			cmd->prot_checks = 0;
 653			break;
 654		case 0x4:
 655			cmd->prot_checks = TARGET_DIF_CHECK_GUARD;
 656			break;
 657		default:
 658			pr_err("Unsupported protect field %d\n", protect);
 659			return -EINVAL;
 660		}
 661	}
 662
 663	return 0;
 664}
 665
 666static sense_reason_t
 667sbc_check_prot(struct se_device *dev, struct se_cmd *cmd, unsigned char protect,
 668	       u32 sectors, bool is_write)
 669{
 670	int sp_ops = cmd->se_sess->sup_prot_ops;
 671	int pi_prot_type = dev->dev_attrib.pi_prot_type;
 672	bool fabric_prot = false;
 673
 674	if (!cmd->t_prot_sg || !cmd->t_prot_nents) {
 675		if (unlikely(protect &&
 676		    !dev->dev_attrib.pi_prot_type && !cmd->se_sess->sess_prot_type)) {
 677			pr_err("CDB contains protect bit, but device + fabric does"
 678			       " not advertise PROTECT=1 feature bit\n");
 679			return TCM_INVALID_CDB_FIELD;
 680		}
 681		if (cmd->prot_pto)
 682			return TCM_NO_SENSE;
 683	}
 684
 685	switch (dev->dev_attrib.pi_prot_type) {
 686	case TARGET_DIF_TYPE3_PROT:
 687		cmd->reftag_seed = 0xffffffff;
 688		break;
 689	case TARGET_DIF_TYPE2_PROT:
 690		if (protect)
 691			return TCM_INVALID_CDB_FIELD;
 692
 693		cmd->reftag_seed = cmd->t_task_lba;
 694		break;
 695	case TARGET_DIF_TYPE1_PROT:
 696		cmd->reftag_seed = cmd->t_task_lba;
 697		break;
 698	case TARGET_DIF_TYPE0_PROT:
 699		/*
 700		 * See if the fabric supports T10-PI, and the session has been
 701		 * configured to allow export PROTECT=1 feature bit with backend
 702		 * devices that don't support T10-PI.
 703		 */
 704		fabric_prot = is_write ?
 705			      !!(sp_ops & (TARGET_PROT_DOUT_PASS | TARGET_PROT_DOUT_STRIP)) :
 706			      !!(sp_ops & (TARGET_PROT_DIN_PASS | TARGET_PROT_DIN_INSERT));
 707
 708		if (fabric_prot && cmd->se_sess->sess_prot_type) {
 709			pi_prot_type = cmd->se_sess->sess_prot_type;
 710			break;
 711		}
 712		if (!protect)
 713			return TCM_NO_SENSE;
 714		fallthrough;
 715	default:
 716		pr_err("Unable to determine pi_prot_type for CDB: 0x%02x "
 717		       "PROTECT: 0x%02x\n", cmd->t_task_cdb[0], protect);
 718		return TCM_INVALID_CDB_FIELD;
 719	}
 720
 721	if (sbc_set_prot_op_checks(protect, fabric_prot, pi_prot_type, is_write, cmd))
 722		return TCM_INVALID_CDB_FIELD;
 723
 724	cmd->prot_type = pi_prot_type;
 725	cmd->prot_length = dev->prot_length * sectors;
 726
 727	/**
 728	 * In case protection information exists over the wire
 729	 * we modify command data length to describe pure data.
 730	 * The actual transfer length is data length + protection
 731	 * length
 732	 **/
 733	if (protect)
 734		cmd->data_length = sectors * dev->dev_attrib.block_size;
 735
 736	pr_debug("%s: prot_type=%d, data_length=%d, prot_length=%d "
 737		 "prot_op=%d prot_checks=%d\n",
 738		 __func__, cmd->prot_type, cmd->data_length, cmd->prot_length,
 739		 cmd->prot_op, cmd->prot_checks);
 740
 741	return TCM_NO_SENSE;
 742}
 743
 744static int
 745sbc_check_dpofua(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
 746{
 747	if (cdb[1] & 0x10) {
 748		/* see explanation in spc_emulate_modesense */
 749		if (!target_check_fua(dev)) {
 750			pr_err("Got CDB: 0x%02x with DPO bit set, but device"
 751			       " does not advertise support for DPO\n", cdb[0]);
 752			return -EINVAL;
 753		}
 754	}
 755	if (cdb[1] & 0x8) {
 756		if (!target_check_fua(dev)) {
 757			pr_err("Got CDB: 0x%02x with FUA bit set, but device"
 758			       " does not advertise support for FUA write\n",
 759			       cdb[0]);
 760			return -EINVAL;
 761		}
 762		cmd->se_cmd_flags |= SCF_FUA;
 763	}
 764	return 0;
 765}
 766
 767static sense_reason_t
 768sbc_check_atomic(struct se_device *dev, struct se_cmd *cmd, unsigned char *cdb)
 769{
 770	struct se_dev_attrib *attrib = &dev->dev_attrib;
 771	u16 boundary, transfer_len;
 772	u64 lba;
 773
 774	lba = transport_lba_64(cdb);
 775	boundary = get_unaligned_be16(&cdb[10]);
 776	transfer_len = get_unaligned_be16(&cdb[12]);
 777
 778	if (!attrib->atomic_max_len)
 779		return TCM_UNSUPPORTED_SCSI_OPCODE;
 780
 781	if (boundary) {
 782		if (transfer_len > attrib->atomic_max_with_boundary)
 783			return TCM_INVALID_CDB_FIELD;
 784
 785		if (boundary > attrib->atomic_max_boundary)
 786			return TCM_INVALID_CDB_FIELD;
 787	} else {
 788		if (transfer_len > attrib->atomic_max_len)
 789			return TCM_INVALID_CDB_FIELD;
 790	}
 791
 792	if (attrib->atomic_granularity) {
 793		if (transfer_len % attrib->atomic_granularity)
 794			return TCM_INVALID_CDB_FIELD;
 795
 796		if (boundary && boundary % attrib->atomic_granularity)
 797			return TCM_INVALID_CDB_FIELD;
 798	}
 799
 800	if (dev->dev_attrib.atomic_alignment) {
 801		u64 _lba = lba;
 802
 803		if (do_div(_lba, dev->dev_attrib.atomic_alignment))
 804			return TCM_INVALID_CDB_FIELD;
 805	}
 806
 807	return 0;
 808}
 809
 810sense_reason_t
 811sbc_parse_cdb(struct se_cmd *cmd, struct exec_cmd_ops *ops)
 812{
 813	struct se_device *dev = cmd->se_dev;
 814	unsigned char *cdb = cmd->t_task_cdb;
 815	unsigned int size;
 816	u32 sectors = 0;
 817	sense_reason_t ret;
 818
 819	cmd->protocol_data = ops;
 820
 821	switch (cdb[0]) {
 822	case READ_6:
 823		sectors = transport_get_sectors_6(cdb);
 824		cmd->t_task_lba = transport_lba_21(cdb);
 825		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 826		cmd->execute_cmd = sbc_execute_rw;
 827		break;
 828	case READ_10:
 829		sectors = transport_get_sectors_10(cdb);
 830		cmd->t_task_lba = transport_lba_32(cdb);
 831
 832		if (sbc_check_dpofua(dev, cmd, cdb))
 833			return TCM_INVALID_CDB_FIELD;
 834
 835		ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 836		if (ret)
 837			return ret;
 838
 839		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 840		cmd->execute_cmd = sbc_execute_rw;
 841		break;
 842	case READ_12:
 843		sectors = transport_get_sectors_12(cdb);
 844		cmd->t_task_lba = transport_lba_32(cdb);
 845
 846		if (sbc_check_dpofua(dev, cmd, cdb))
 847			return TCM_INVALID_CDB_FIELD;
 848
 849		ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 850		if (ret)
 851			return ret;
 852
 853		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 854		cmd->execute_cmd = sbc_execute_rw;
 855		break;
 856	case READ_16:
 857		sectors = transport_get_sectors_16(cdb);
 858		cmd->t_task_lba = transport_lba_64(cdb);
 859
 860		if (sbc_check_dpofua(dev, cmd, cdb))
 861			return TCM_INVALID_CDB_FIELD;
 862
 863		ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, false);
 864		if (ret)
 865			return ret;
 866
 867		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 868		cmd->execute_cmd = sbc_execute_rw;
 869		break;
 870	case WRITE_6:
 871		sectors = transport_get_sectors_6(cdb);
 872		cmd->t_task_lba = transport_lba_21(cdb);
 873		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 874		cmd->execute_cmd = sbc_execute_rw;
 875		break;
 876	case WRITE_10:
 877	case WRITE_VERIFY:
 878		sectors = transport_get_sectors_10(cdb);
 879		cmd->t_task_lba = transport_lba_32(cdb);
 880
 881		if (sbc_check_dpofua(dev, cmd, cdb))
 882			return TCM_INVALID_CDB_FIELD;
 883
 884		ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
 885		if (ret)
 886			return ret;
 887
 888		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 889		cmd->execute_cmd = sbc_execute_rw;
 890		break;
 891	case WRITE_12:
 892		sectors = transport_get_sectors_12(cdb);
 893		cmd->t_task_lba = transport_lba_32(cdb);
 894
 895		if (sbc_check_dpofua(dev, cmd, cdb))
 896			return TCM_INVALID_CDB_FIELD;
 897
 898		ret = sbc_check_prot(dev, cmd, cdb[1] >> 5, sectors, true);
 899		if (ret)
 900			return ret;
 901
 902		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 903		cmd->execute_cmd = sbc_execute_rw;
 904		break;
 905	case WRITE_16:
 906	case WRITE_VERIFY_16:
 907	case WRITE_ATOMIC_16:
 908		sectors = transport_get_sectors_16(cdb);
 909		cmd->t_task_lba = transport_lba_64(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[1] >> 5, sectors, true);
 915		if (ret)
 916			return ret;
 917
 918		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB;
 919		if (cdb[0] == WRITE_ATOMIC_16) {
 920			cmd->se_cmd_flags |= SCF_ATOMIC;
 921
 922			ret = sbc_check_atomic(dev, cmd, cdb);
 923			if (ret)
 924				return ret;
 925		}
 926		cmd->execute_cmd = sbc_execute_rw;
 927		break;
 928	case VARIABLE_LENGTH_CMD:
 929	{
 930		u16 service_action = get_unaligned_be16(&cdb[8]);
 931		switch (service_action) {
 932		case WRITE_SAME_32:
 933			sectors = transport_get_sectors_32(cdb);
 934			if (!sectors) {
 935				pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not"
 936				       " supported\n");
 937				return TCM_INVALID_CDB_FIELD;
 938			}
 939
 940			size = sbc_get_size(cmd, 1);
 941			cmd->t_task_lba = get_unaligned_be64(&cdb[12]);
 942
 943			ret = sbc_setup_write_same(cmd, cdb[10], ops);
 944			if (ret)
 945				return ret;
 946			break;
 947		default:
 948			pr_err("VARIABLE_LENGTH_CMD service action"
 949				" 0x%04x not supported\n", service_action);
 950			return TCM_UNSUPPORTED_SCSI_OPCODE;
 951		}
 952		break;
 953	}
 954	case COMPARE_AND_WRITE:
 955		if (!dev->dev_attrib.emulate_caw) {
 956			pr_err_ratelimited("se_device %s/%s (vpd_unit_serial %s) reject COMPARE_AND_WRITE\n",
 957					   dev->se_hba->backend->ops->name,
 958					   config_item_name(&dev->dev_group.cg_item),
 959					   dev->t10_wwn.unit_serial);
 960			return TCM_UNSUPPORTED_SCSI_OPCODE;
 961		}
 962		sectors = cdb[13];
 963		/*
 964		 * Currently enforce COMPARE_AND_WRITE for a single sector
 965		 */
 966		if (sectors > 1) {
 967			pr_err("COMPARE_AND_WRITE contains NoLB: %u greater"
 968			       " than 1\n", sectors);
 969			return TCM_INVALID_CDB_FIELD;
 970		}
 971		if (sbc_check_dpofua(dev, cmd, cdb))
 972			return TCM_INVALID_CDB_FIELD;
 973
 974		/*
 975		 * Double size because we have two buffers, note that
 976		 * zero is not an error..
 977		 */
 978		size = 2 * sbc_get_size(cmd, sectors);
 979		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
 980		cmd->t_task_nolb = sectors;
 981		cmd->se_cmd_flags |= SCF_SCSI_DATA_CDB | SCF_COMPARE_AND_WRITE;
 982		cmd->execute_cmd = sbc_compare_and_write;
 983		cmd->transport_complete_callback = compare_and_write_callback;
 984		break;
 985	case READ_CAPACITY:
 986		size = READ_CAP_LEN;
 987		cmd->execute_cmd = sbc_emulate_readcapacity;
 988		break;
 989	case SERVICE_ACTION_IN_16:
 990		switch (cmd->t_task_cdb[1] & 0x1f) {
 991		case SAI_READ_CAPACITY_16:
 992			cmd->execute_cmd = sbc_emulate_readcapacity_16;
 993			break;
 994		case SAI_REPORT_REFERRALS:
 995			cmd->execute_cmd = target_emulate_report_referrals;
 996			break;
 997		default:
 998			pr_err("Unsupported SA: 0x%02x\n",
 999				cmd->t_task_cdb[1] & 0x1f);
1000			return TCM_INVALID_CDB_FIELD;
1001		}
1002		size = get_unaligned_be32(&cdb[10]);
1003		break;
1004	case SYNCHRONIZE_CACHE:
1005	case SYNCHRONIZE_CACHE_16:
1006		if (cdb[0] == SYNCHRONIZE_CACHE) {
1007			sectors = transport_get_sectors_10(cdb);
1008			cmd->t_task_lba = transport_lba_32(cdb);
1009		} else {
1010			sectors = transport_get_sectors_16(cdb);
1011			cmd->t_task_lba = transport_lba_64(cdb);
1012		}
1013		if (ops->execute_sync_cache) {
1014			cmd->execute_cmd = ops->execute_sync_cache;
1015			goto check_lba;
1016		}
1017		size = 0;
1018		cmd->execute_cmd = sbc_emulate_noop;
1019		break;
1020	case UNMAP:
1021		if (!ops->execute_unmap)
1022			return TCM_UNSUPPORTED_SCSI_OPCODE;
1023
1024		if (!dev->dev_attrib.emulate_tpu) {
1025			pr_err("Got UNMAP, but backend device has"
1026			       " emulate_tpu disabled\n");
1027			return TCM_UNSUPPORTED_SCSI_OPCODE;
1028		}
1029		size = get_unaligned_be16(&cdb[7]);
1030		cmd->execute_cmd = sbc_execute_unmap;
1031		break;
1032	case WRITE_SAME_16:
1033		sectors = transport_get_sectors_16(cdb);
1034		if (!sectors) {
1035			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1036			return TCM_INVALID_CDB_FIELD;
1037		}
1038
1039		size = sbc_get_size(cmd, 1);
1040		cmd->t_task_lba = get_unaligned_be64(&cdb[2]);
1041
1042		ret = sbc_setup_write_same(cmd, cdb[1], ops);
1043		if (ret)
1044			return ret;
1045		break;
1046	case WRITE_SAME:
1047		sectors = transport_get_sectors_10(cdb);
1048		if (!sectors) {
1049			pr_err("WSNZ=1, WRITE_SAME w/sectors=0 not supported\n");
1050			return TCM_INVALID_CDB_FIELD;
1051		}
1052
1053		size = sbc_get_size(cmd, 1);
1054		cmd->t_task_lba = get_unaligned_be32(&cdb[2]);
1055
1056		/*
1057		 * Follow sbcr26 with WRITE_SAME (10) and check for the existence
1058		 * of byte 1 bit 3 UNMAP instead of original reserved field
1059		 */
1060		ret = sbc_setup_write_same(cmd, cdb[1], ops);
1061		if (ret)
1062			return ret;
1063		break;
1064	case VERIFY:
1065	case VERIFY_16:
1066		size = 0;
1067		if (cdb[0] == VERIFY) {
1068			sectors = transport_get_sectors_10(cdb);
1069			cmd->t_task_lba = transport_lba_32(cdb);
1070		} else {
1071			sectors = transport_get_sectors_16(cdb);
1072			cmd->t_task_lba = transport_lba_64(cdb);
1073		}
1074		cmd->execute_cmd = sbc_emulate_noop;
1075		goto check_lba;
1076	case REZERO_UNIT:
1077	case SEEK_6:
1078	case SEEK_10:
1079		/*
1080		 * There are still clients out there which use these old SCSI-2
1081		 * commands. This mainly happens when running VMs with legacy
1082		 * guest systems, connected via SCSI command pass-through to
1083		 * iSCSI targets. Make them happy and return status GOOD.
1084		 */
1085		size = 0;
1086		cmd->execute_cmd = sbc_emulate_noop;
1087		break;
1088	case START_STOP:
1089		size = 0;
1090		cmd->execute_cmd = sbc_emulate_startstop;
1091		break;
1092	default:
1093		ret = spc_parse_cdb(cmd, &size);
1094		if (ret)
1095			return ret;
1096	}
1097
1098	/* reject any command that we don't have a handler for */
1099	if (!cmd->execute_cmd)
1100		return TCM_UNSUPPORTED_SCSI_OPCODE;
1101
1102	if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1103		unsigned long long end_lba;
1104check_lba:
1105		end_lba = dev->transport->get_blocks(dev) + 1;
1106		if (((cmd->t_task_lba + sectors) < cmd->t_task_lba) ||
1107		    ((cmd->t_task_lba + sectors) > end_lba)) {
1108			pr_err("cmd exceeds last lba %llu "
1109				"(lba %llu, sectors %u)\n",
1110				end_lba, cmd->t_task_lba, sectors);
1111			return TCM_ADDRESS_OUT_OF_RANGE;
1112		}
1113
1114		if (!(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE))
1115			size = sbc_get_size(cmd, sectors);
1116	}
1117
1118	return target_cmd_size_check(cmd, size);
1119}
1120EXPORT_SYMBOL(sbc_parse_cdb);
1121
1122u32 sbc_get_device_type(struct se_device *dev)
1123{
1124	return TYPE_DISK;
1125}
1126EXPORT_SYMBOL(sbc_get_device_type);
1127
1128static sense_reason_t
1129sbc_execute_unmap(struct se_cmd *cmd)
1130{
1131	struct exec_cmd_ops *ops = cmd->protocol_data;
1132	struct se_device *dev = cmd->se_dev;
1133	unsigned char *buf, *ptr = NULL;
1134	sector_t lba;
1135	int size;
1136	u32 range;
1137	sense_reason_t ret = 0;
1138	int dl, bd_dl;
1139
1140	/* We never set ANC_SUP */
1141	if (cmd->t_task_cdb[1])
1142		return TCM_INVALID_CDB_FIELD;
1143
1144	if (cmd->data_length == 0) {
1145		target_complete_cmd(cmd, SAM_STAT_GOOD);
1146		return 0;
1147	}
1148
1149	if (cmd->data_length < 8) {
1150		pr_warn("UNMAP parameter list length %u too small\n",
1151			cmd->data_length);
1152		return TCM_PARAMETER_LIST_LENGTH_ERROR;
1153	}
1154
1155	buf = transport_kmap_data_sg(cmd);
1156	if (!buf)
1157		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1158
1159	dl = get_unaligned_be16(&buf[0]);
1160	bd_dl = get_unaligned_be16(&buf[2]);
1161
1162	size = cmd->data_length - 8;
1163	if (bd_dl > size)
1164		pr_warn("UNMAP parameter list length %u too small, ignoring bd_dl %u\n",
1165			cmd->data_length, bd_dl);
1166	else
1167		size = bd_dl;
1168
1169	if (size / 16 > dev->dev_attrib.max_unmap_block_desc_count) {
1170		ret = TCM_INVALID_PARAMETER_LIST;
1171		goto err;
1172	}
1173
1174	/* First UNMAP block descriptor starts at 8 byte offset */
1175	ptr = &buf[8];
1176	pr_debug("UNMAP: Sub: %s Using dl: %u bd_dl: %u size: %u"
1177		" ptr: %p\n", dev->transport->name, dl, bd_dl, size, ptr);
1178
1179	while (size >= 16) {
1180		lba = get_unaligned_be64(&ptr[0]);
1181		range = get_unaligned_be32(&ptr[8]);
1182		pr_debug("UNMAP: Using lba: %llu and range: %u\n",
1183				 (unsigned long long)lba, range);
1184
1185		if (range > dev->dev_attrib.max_unmap_lba_count) {
1186			ret = TCM_INVALID_PARAMETER_LIST;
1187			goto err;
1188		}
1189
1190		if (lba + range > dev->transport->get_blocks(dev) + 1) {
1191			ret = TCM_ADDRESS_OUT_OF_RANGE;
1192			goto err;
1193		}
1194
1195		if (range) {
1196			ret = ops->execute_unmap(cmd, lba, range);
1197			if (ret)
1198				goto err;
1199		}
1200
1201		ptr += 16;
1202		size -= 16;
1203	}
1204
1205err:
1206	transport_kunmap_data_sg(cmd);
1207	if (!ret)
1208		target_complete_cmd(cmd, SAM_STAT_GOOD);
1209	return ret;
1210}
1211
1212void
1213sbc_dif_generate(struct se_cmd *cmd)
1214{
1215	struct se_device *dev = cmd->se_dev;
1216	struct t10_pi_tuple *sdt;
1217	struct scatterlist *dsg = cmd->t_data_sg, *psg;
1218	sector_t sector = cmd->t_task_lba;
1219	void *daddr, *paddr;
1220	int i, j, offset = 0;
1221	unsigned int block_size = dev->dev_attrib.block_size;
1222
1223	for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1224		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1225		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1226
1227		for (j = 0; j < psg->length;
1228				j += sizeof(*sdt)) {
1229			__u16 crc;
1230			unsigned int avail;
1231
1232			if (offset >= dsg->length) {
1233				offset -= dsg->length;
1234				kunmap_atomic(daddr - dsg->offset);
1235				dsg = sg_next(dsg);
1236				if (!dsg) {
1237					kunmap_atomic(paddr - psg->offset);
1238					return;
1239				}
1240				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1241			}
1242
1243			sdt = paddr + j;
1244			avail = min(block_size, dsg->length - offset);
1245			crc = crc_t10dif(daddr + offset, avail);
1246			if (avail < block_size) {
1247				kunmap_atomic(daddr - dsg->offset);
1248				dsg = sg_next(dsg);
1249				if (!dsg) {
1250					kunmap_atomic(paddr - psg->offset);
1251					return;
1252				}
1253				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1254				offset = block_size - avail;
1255				crc = crc_t10dif_update(crc, daddr, offset);
1256			} else {
1257				offset += block_size;
1258			}
1259
1260			sdt->guard_tag = cpu_to_be16(crc);
1261			if (cmd->prot_type == TARGET_DIF_TYPE1_PROT)
1262				sdt->ref_tag = cpu_to_be32(sector & 0xffffffff);
1263			sdt->app_tag = 0;
1264
1265			pr_debug("DIF %s INSERT sector: %llu guard_tag: 0x%04x"
1266				 " app_tag: 0x%04x ref_tag: %u\n",
1267				 (cmd->data_direction == DMA_TO_DEVICE) ?
1268				 "WRITE" : "READ", (unsigned long long)sector,
1269				 sdt->guard_tag, sdt->app_tag,
1270				 be32_to_cpu(sdt->ref_tag));
1271
1272			sector++;
1273		}
1274
1275		kunmap_atomic(daddr - dsg->offset);
1276		kunmap_atomic(paddr - psg->offset);
1277	}
1278}
1279
1280static sense_reason_t
1281sbc_dif_v1_verify(struct se_cmd *cmd, struct t10_pi_tuple *sdt,
1282		  __u16 crc, sector_t sector, unsigned int ei_lba)
1283{
1284	__be16 csum;
1285
1286	if (!(cmd->prot_checks & TARGET_DIF_CHECK_GUARD))
1287		goto check_ref;
1288
1289	csum = cpu_to_be16(crc);
1290
1291	if (sdt->guard_tag != csum) {
1292		pr_err("DIFv1 checksum failed on sector %llu guard tag 0x%04x"
1293			" csum 0x%04x\n", (unsigned long long)sector,
1294			be16_to_cpu(sdt->guard_tag), be16_to_cpu(csum));
1295		return TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
1296	}
1297
1298check_ref:
1299	if (!(cmd->prot_checks & TARGET_DIF_CHECK_REFTAG))
1300		return 0;
1301
1302	if (cmd->prot_type == TARGET_DIF_TYPE1_PROT &&
1303	    be32_to_cpu(sdt->ref_tag) != (sector & 0xffffffff)) {
1304		pr_err("DIFv1 Type 1 reference failed on sector: %llu tag: 0x%08x"
1305		       " sector MSB: 0x%08x\n", (unsigned long long)sector,
1306		       be32_to_cpu(sdt->ref_tag), (u32)(sector & 0xffffffff));
1307		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1308	}
1309
1310	if (cmd->prot_type == TARGET_DIF_TYPE2_PROT &&
1311	    be32_to_cpu(sdt->ref_tag) != ei_lba) {
1312		pr_err("DIFv1 Type 2 reference failed on sector: %llu tag: 0x%08x"
1313		       " ei_lba: 0x%08x\n", (unsigned long long)sector,
1314			be32_to_cpu(sdt->ref_tag), ei_lba);
1315		return TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
1316	}
1317
1318	return 0;
1319}
1320
1321void sbc_dif_copy_prot(struct se_cmd *cmd, unsigned int sectors, bool read,
1322		       struct scatterlist *sg, int sg_off)
1323{
1324	struct se_device *dev = cmd->se_dev;
1325	struct scatterlist *psg;
1326	void *paddr, *addr;
1327	unsigned int i, len, left;
1328	unsigned int offset = sg_off;
1329
1330	if (!sg)
1331		return;
1332
1333	left = sectors * dev->prot_length;
1334
1335	for_each_sg(cmd->t_prot_sg, psg, cmd->t_prot_nents, i) {
1336		unsigned int psg_len, copied = 0;
1337
1338		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1339		psg_len = min(left, psg->length);
1340		while (psg_len) {
1341			len = min(psg_len, sg->length - offset);
1342			addr = kmap_atomic(sg_page(sg)) + sg->offset + offset;
1343
1344			if (read)
1345				memcpy(paddr + copied, addr, len);
1346			else
1347				memcpy(addr, paddr + copied, len);
1348
1349			left -= len;
1350			offset += len;
1351			copied += len;
1352			psg_len -= len;
1353
1354			kunmap_atomic(addr - sg->offset - offset);
1355
1356			if (offset >= sg->length) {
1357				sg = sg_next(sg);
1358				offset = 0;
1359			}
1360		}
1361		kunmap_atomic(paddr - psg->offset);
1362	}
1363}
1364EXPORT_SYMBOL(sbc_dif_copy_prot);
1365
1366sense_reason_t
1367sbc_dif_verify(struct se_cmd *cmd, sector_t start, unsigned int sectors,
1368	       unsigned int ei_lba, struct scatterlist *psg, int psg_off)
1369{
1370	struct se_device *dev = cmd->se_dev;
1371	struct t10_pi_tuple *sdt;
1372	struct scatterlist *dsg = cmd->t_data_sg;
1373	sector_t sector = start;
1374	void *daddr, *paddr;
1375	int i;
1376	sense_reason_t rc;
1377	int dsg_off = 0;
1378	unsigned int block_size = dev->dev_attrib.block_size;
1379
1380	for (; psg && sector < start + sectors; psg = sg_next(psg)) {
1381		paddr = kmap_atomic(sg_page(psg)) + psg->offset;
1382		daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1383
1384		for (i = psg_off; i < psg->length &&
1385				sector < start + sectors;
1386				i += sizeof(*sdt)) {
1387			__u16 crc;
1388			unsigned int avail;
1389
1390			if (dsg_off >= dsg->length) {
1391				dsg_off -= dsg->length;
1392				kunmap_atomic(daddr - dsg->offset);
1393				dsg = sg_next(dsg);
1394				if (!dsg) {
1395					kunmap_atomic(paddr - psg->offset);
1396					return 0;
1397				}
1398				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1399			}
1400
1401			sdt = paddr + i;
1402
1403			pr_debug("DIF READ sector: %llu guard_tag: 0x%04x"
1404				 " app_tag: 0x%04x ref_tag: %u\n",
1405				 (unsigned long long)sector, sdt->guard_tag,
1406				 sdt->app_tag, be32_to_cpu(sdt->ref_tag));
1407
1408			if (sdt->app_tag == T10_PI_APP_ESCAPE) {
1409				dsg_off += block_size;
1410				goto next;
1411			}
1412
1413			avail = min(block_size, dsg->length - dsg_off);
1414			crc = crc_t10dif(daddr + dsg_off, avail);
1415			if (avail < block_size) {
1416				kunmap_atomic(daddr - dsg->offset);
1417				dsg = sg_next(dsg);
1418				if (!dsg) {
1419					kunmap_atomic(paddr - psg->offset);
1420					return 0;
1421				}
1422				daddr = kmap_atomic(sg_page(dsg)) + dsg->offset;
1423				dsg_off = block_size - avail;
1424				crc = crc_t10dif_update(crc, daddr, dsg_off);
1425			} else {
1426				dsg_off += block_size;
1427			}
1428
1429			rc = sbc_dif_v1_verify(cmd, sdt, crc, sector, ei_lba);
1430			if (rc) {
1431				kunmap_atomic(daddr - dsg->offset);
1432				kunmap_atomic(paddr - psg->offset);
1433				cmd->sense_info = sector;
1434				return rc;
1435			}
1436next:
1437			sector++;
1438			ei_lba++;
1439		}
1440
1441		psg_off = 0;
1442		kunmap_atomic(daddr - dsg->offset);
1443		kunmap_atomic(paddr - psg->offset);
1444	}
1445
1446	return 0;
1447}
1448EXPORT_SYMBOL(sbc_dif_verify);