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   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*******************************************************************************
   3 * Filename: target_core_xcopy.c
   4 *
   5 * This file contains support for SPC-4 Extended-Copy offload with generic
   6 * TCM backends.
   7 *
   8 * Copyright (c) 2011-2013 Datera, Inc. All rights reserved.
   9 *
  10 * Author:
  11 * Nicholas A. Bellinger <nab@daterainc.com>
  12 *
  13 ******************************************************************************/
  14
  15#include <linux/slab.h>
  16#include <linux/spinlock.h>
  17#include <linux/list.h>
  18#include <linux/rculist.h>
  19#include <linux/configfs.h>
  20#include <linux/ratelimit.h>
  21#include <scsi/scsi_proto.h>
  22#include <asm/unaligned.h>
  23
  24#include <target/target_core_base.h>
  25#include <target/target_core_backend.h>
  26#include <target/target_core_fabric.h>
  27
  28#include "target_core_internal.h"
  29#include "target_core_pr.h"
  30#include "target_core_ua.h"
  31#include "target_core_xcopy.h"
  32
  33static struct workqueue_struct *xcopy_wq = NULL;
  34
  35static sense_reason_t target_parse_xcopy_cmd(struct xcopy_op *xop);
  36
  37/**
  38 * target_xcopy_locate_se_dev_e4_iter - compare XCOPY NAA device identifiers
  39 *
  40 * @se_dev: device being considered for match
  41 * @dev_wwn: XCOPY requested NAA dev_wwn
  42 * @return: 1 on match, 0 on no-match
  43 */
  44static int target_xcopy_locate_se_dev_e4_iter(struct se_device *se_dev,
  45					      const unsigned char *dev_wwn)
  46{
  47	unsigned char tmp_dev_wwn[XCOPY_NAA_IEEE_REGEX_LEN];
  48	int rc;
  49
  50	if (!se_dev->dev_attrib.emulate_3pc) {
  51		pr_debug("XCOPY: emulate_3pc disabled on se_dev %p\n", se_dev);
  52		return 0;
  53	}
  54
  55	memset(&tmp_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
  56	spc_gen_naa_6h_vendor_specific(se_dev, &tmp_dev_wwn[0]);
  57
  58	rc = memcmp(&tmp_dev_wwn[0], dev_wwn, XCOPY_NAA_IEEE_REGEX_LEN);
  59	if (rc != 0) {
  60		pr_debug("XCOPY: skip non-matching: %*ph\n",
  61			 XCOPY_NAA_IEEE_REGEX_LEN, tmp_dev_wwn);
  62		return 0;
  63	}
  64	pr_debug("XCOPY 0xe4: located se_dev: %p\n", se_dev);
  65
  66	return 1;
  67}
  68
  69static int target_xcopy_locate_se_dev_e4(struct se_session *sess,
  70					const unsigned char *dev_wwn,
  71					struct se_device **_found_dev,
  72					struct percpu_ref **_found_lun_ref)
  73{
  74	struct se_dev_entry *deve;
  75	struct se_node_acl *nacl;
  76	struct se_lun *this_lun = NULL;
  77	struct se_device *found_dev = NULL;
  78
  79	/* cmd with NULL sess indicates no associated $FABRIC_MOD */
  80	if (!sess)
  81		goto err_out;
  82
  83	pr_debug("XCOPY 0xe4: searching for: %*ph\n",
  84		 XCOPY_NAA_IEEE_REGEX_LEN, dev_wwn);
  85
  86	nacl = sess->se_node_acl;
  87	rcu_read_lock();
  88	hlist_for_each_entry_rcu(deve, &nacl->lun_entry_hlist, link) {
  89		struct se_device *this_dev;
  90		int rc;
  91
  92		this_lun = deve->se_lun;
  93		this_dev = rcu_dereference_raw(this_lun->lun_se_dev);
  94
  95		rc = target_xcopy_locate_se_dev_e4_iter(this_dev, dev_wwn);
  96		if (rc) {
  97			if (percpu_ref_tryget_live(&this_lun->lun_ref))
  98				found_dev = this_dev;
  99			break;
 100		}
 101	}
 102	rcu_read_unlock();
 103	if (found_dev == NULL)
 104		goto err_out;
 105
 106	pr_debug("lun_ref held for se_dev: %p se_dev->se_dev_group: %p\n",
 107		 found_dev, &found_dev->dev_group);
 108	*_found_dev = found_dev;
 109	*_found_lun_ref = &this_lun->lun_ref;
 110	return 0;
 111err_out:
 112	pr_debug_ratelimited("Unable to locate 0xe4 descriptor for EXTENDED_COPY\n");
 113	return -EINVAL;
 114}
 115
 116static int target_xcopy_parse_tiddesc_e4(struct se_cmd *se_cmd, struct xcopy_op *xop,
 117				unsigned char *p, unsigned short cscd_index)
 118{
 119	unsigned char *desc = p;
 120	unsigned short ript;
 121	u8 desig_len;
 122	/*
 123	 * Extract RELATIVE INITIATOR PORT IDENTIFIER
 124	 */
 125	ript = get_unaligned_be16(&desc[2]);
 126	pr_debug("XCOPY 0xe4: RELATIVE INITIATOR PORT IDENTIFIER: %hu\n", ript);
 127	/*
 128	 * Check for supported code set, association, and designator type
 129	 */
 130	if ((desc[4] & 0x0f) != 0x1) {
 131		pr_err("XCOPY 0xe4: code set of non binary type not supported\n");
 132		return -EINVAL;
 133	}
 134	if ((desc[5] & 0x30) != 0x00) {
 135		pr_err("XCOPY 0xe4: association other than LUN not supported\n");
 136		return -EINVAL;
 137	}
 138	if ((desc[5] & 0x0f) != 0x3) {
 139		pr_err("XCOPY 0xe4: designator type unsupported: 0x%02x\n",
 140				(desc[5] & 0x0f));
 141		return -EINVAL;
 142	}
 143	/*
 144	 * Check for matching 16 byte length for NAA IEEE Registered Extended
 145	 * Assigned designator
 146	 */
 147	desig_len = desc[7];
 148	if (desig_len != XCOPY_NAA_IEEE_REGEX_LEN) {
 149		pr_err("XCOPY 0xe4: invalid desig_len: %d\n", (int)desig_len);
 150		return -EINVAL;
 151	}
 152	pr_debug("XCOPY 0xe4: desig_len: %d\n", (int)desig_len);
 153	/*
 154	 * Check for NAA IEEE Registered Extended Assigned header..
 155	 */
 156	if ((desc[8] & 0xf0) != 0x60) {
 157		pr_err("XCOPY 0xe4: Unsupported DESIGNATOR TYPE: 0x%02x\n",
 158					(desc[8] & 0xf0));
 159		return -EINVAL;
 160	}
 161
 162	if (cscd_index != xop->stdi && cscd_index != xop->dtdi) {
 163		pr_debug("XCOPY 0xe4: ignoring CSCD entry %d - neither src nor "
 164			 "dest\n", cscd_index);
 165		return 0;
 166	}
 167
 168	if (cscd_index == xop->stdi) {
 169		memcpy(&xop->src_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
 170		/*
 171		 * Determine if the source designator matches the local device
 172		 */
 173		if (!memcmp(&xop->local_dev_wwn[0], &xop->src_tid_wwn[0],
 174				XCOPY_NAA_IEEE_REGEX_LEN)) {
 175			xop->op_origin = XCOL_SOURCE_RECV_OP;
 176			xop->src_dev = se_cmd->se_dev;
 177			pr_debug("XCOPY 0xe4: Set xop->src_dev %p from source"
 178					" received xop\n", xop->src_dev);
 179		}
 180	}
 181
 182	if (cscd_index == xop->dtdi) {
 183		memcpy(&xop->dst_tid_wwn[0], &desc[8], XCOPY_NAA_IEEE_REGEX_LEN);
 184		/*
 185		 * Determine if the destination designator matches the local
 186		 * device. If @cscd_index corresponds to both source (stdi) and
 187		 * destination (dtdi), or dtdi comes after stdi, then
 188		 * XCOL_DEST_RECV_OP wins.
 189		 */
 190		if (!memcmp(&xop->local_dev_wwn[0], &xop->dst_tid_wwn[0],
 191				XCOPY_NAA_IEEE_REGEX_LEN)) {
 192			xop->op_origin = XCOL_DEST_RECV_OP;
 193			xop->dst_dev = se_cmd->se_dev;
 194			pr_debug("XCOPY 0xe4: Set xop->dst_dev: %p from destination"
 195				" received xop\n", xop->dst_dev);
 196		}
 197	}
 198
 199	return 0;
 200}
 201
 202static int target_xcopy_parse_target_descriptors(struct se_cmd *se_cmd,
 203				struct xcopy_op *xop, unsigned char *p,
 204				unsigned short tdll, sense_reason_t *sense_ret)
 205{
 206	struct se_device *local_dev = se_cmd->se_dev;
 207	unsigned char *desc = p;
 208	int offset = tdll % XCOPY_TARGET_DESC_LEN, rc;
 209	unsigned short cscd_index = 0;
 210	unsigned short start = 0;
 211
 212	*sense_ret = TCM_INVALID_PARAMETER_LIST;
 213
 214	if (offset != 0) {
 215		pr_err("XCOPY target descriptor list length is not"
 216			" multiple of %d\n", XCOPY_TARGET_DESC_LEN);
 217		*sense_ret = TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE;
 218		return -EINVAL;
 219	}
 220	if (tdll > RCR_OP_MAX_TARGET_DESC_COUNT * XCOPY_TARGET_DESC_LEN) {
 221		pr_err("XCOPY target descriptor supports a maximum"
 222			" two src/dest descriptors, tdll: %hu too large..\n", tdll);
 223		/* spc4r37 6.4.3.4 CSCD DESCRIPTOR LIST LENGTH field */
 224		*sense_ret = TCM_TOO_MANY_TARGET_DESCS;
 225		return -EINVAL;
 226	}
 227	/*
 228	 * Generate an IEEE Registered Extended designator based upon the
 229	 * se_device the XCOPY was received upon..
 230	 */
 231	memset(&xop->local_dev_wwn[0], 0, XCOPY_NAA_IEEE_REGEX_LEN);
 232	spc_gen_naa_6h_vendor_specific(local_dev, &xop->local_dev_wwn[0]);
 233
 234	while (start < tdll) {
 235		/*
 236		 * Check target descriptor identification with 0xE4 type, and
 237		 * compare the current index with the CSCD descriptor IDs in
 238		 * the segment descriptor. Use VPD 0x83 WWPN matching ..
 239		 */
 240		switch (desc[0]) {
 241		case 0xe4:
 242			rc = target_xcopy_parse_tiddesc_e4(se_cmd, xop,
 243							&desc[0], cscd_index);
 244			if (rc != 0)
 245				goto out;
 246			start += XCOPY_TARGET_DESC_LEN;
 247			desc += XCOPY_TARGET_DESC_LEN;
 248			cscd_index++;
 249			break;
 250		default:
 251			pr_err("XCOPY unsupported descriptor type code:"
 252					" 0x%02x\n", desc[0]);
 253			*sense_ret = TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE;
 254			goto out;
 255		}
 256	}
 257
 258	switch (xop->op_origin) {
 259	case XCOL_SOURCE_RECV_OP:
 260		rc = target_xcopy_locate_se_dev_e4(se_cmd->se_sess,
 261						xop->dst_tid_wwn,
 262						&xop->dst_dev,
 263						&xop->remote_lun_ref);
 264		break;
 265	case XCOL_DEST_RECV_OP:
 266		rc = target_xcopy_locate_se_dev_e4(se_cmd->se_sess,
 267						xop->src_tid_wwn,
 268						&xop->src_dev,
 269						&xop->remote_lun_ref);
 270		break;
 271	default:
 272		pr_err("XCOPY CSCD descriptor IDs not found in CSCD list - "
 273			"stdi: %hu dtdi: %hu\n", xop->stdi, xop->dtdi);
 274		rc = -EINVAL;
 275		break;
 276	}
 277	/*
 278	 * If a matching IEEE NAA 0x83 descriptor for the requested device
 279	 * is not located on this node, return COPY_ABORTED with ASQ/ASQC
 280	 * 0x0d/0x02 - COPY_TARGET_DEVICE_NOT_REACHABLE to request the
 281	 * initiator to fall back to normal copy method.
 282	 */
 283	if (rc < 0) {
 284		*sense_ret = TCM_COPY_TARGET_DEVICE_NOT_REACHABLE;
 285		goto out;
 286	}
 287
 288	pr_debug("XCOPY TGT desc: Source dev: %p NAA IEEE WWN: 0x%16phN\n",
 289		 xop->src_dev, &xop->src_tid_wwn[0]);
 290	pr_debug("XCOPY TGT desc: Dest dev: %p NAA IEEE WWN: 0x%16phN\n",
 291		 xop->dst_dev, &xop->dst_tid_wwn[0]);
 292
 293	return cscd_index;
 294
 295out:
 296	return -EINVAL;
 297}
 298
 299static int target_xcopy_parse_segdesc_02(struct xcopy_op *xop, unsigned char *p)
 300{
 301	unsigned char *desc = p;
 302	int dc = (desc[1] & 0x02);
 303	unsigned short desc_len;
 304
 305	desc_len = get_unaligned_be16(&desc[2]);
 306	if (desc_len != 0x18) {
 307		pr_err("XCOPY segment desc 0x02: Illegal desc_len:"
 308				" %hu\n", desc_len);
 309		return -EINVAL;
 310	}
 311
 312	xop->stdi = get_unaligned_be16(&desc[4]);
 313	xop->dtdi = get_unaligned_be16(&desc[6]);
 314
 315	if (xop->stdi > XCOPY_CSCD_DESC_ID_LIST_OFF_MAX ||
 316	    xop->dtdi > XCOPY_CSCD_DESC_ID_LIST_OFF_MAX) {
 317		pr_err("XCOPY segment desc 0x02: unsupported CSCD ID > 0x%x; stdi: %hu dtdi: %hu\n",
 318			XCOPY_CSCD_DESC_ID_LIST_OFF_MAX, xop->stdi, xop->dtdi);
 319		return -EINVAL;
 320	}
 321
 322	pr_debug("XCOPY seg desc 0x02: desc_len: %hu stdi: %hu dtdi: %hu, DC: %d\n",
 323		desc_len, xop->stdi, xop->dtdi, dc);
 324
 325	xop->nolb = get_unaligned_be16(&desc[10]);
 326	xop->src_lba = get_unaligned_be64(&desc[12]);
 327	xop->dst_lba = get_unaligned_be64(&desc[20]);
 328	pr_debug("XCOPY seg desc 0x02: nolb: %hu src_lba: %llu dst_lba: %llu\n",
 329		xop->nolb, (unsigned long long)xop->src_lba,
 330		(unsigned long long)xop->dst_lba);
 331
 332	return 0;
 333}
 334
 335static int target_xcopy_parse_segment_descriptors(struct xcopy_op *xop,
 336				unsigned char *p, unsigned int sdll,
 337				sense_reason_t *sense_ret)
 338{
 339	unsigned char *desc = p;
 340	unsigned int start = 0;
 341	int offset = sdll % XCOPY_SEGMENT_DESC_LEN, rc, ret = 0;
 342
 343	*sense_ret = TCM_INVALID_PARAMETER_LIST;
 344
 345	if (offset != 0) {
 346		pr_err("XCOPY segment descriptor list length is not"
 347			" multiple of %d\n", XCOPY_SEGMENT_DESC_LEN);
 348		*sense_ret = TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE;
 349		return -EINVAL;
 350	}
 351	if (sdll > RCR_OP_MAX_SG_DESC_COUNT * XCOPY_SEGMENT_DESC_LEN) {
 352		pr_err("XCOPY supports %u segment descriptor(s), sdll: %u too"
 353			" large..\n", RCR_OP_MAX_SG_DESC_COUNT, sdll);
 354		/* spc4r37 6.4.3.5 SEGMENT DESCRIPTOR LIST LENGTH field */
 355		*sense_ret = TCM_TOO_MANY_SEGMENT_DESCS;
 356		return -EINVAL;
 357	}
 358
 359	while (start < sdll) {
 360		/*
 361		 * Check segment descriptor type code for block -> block
 362		 */
 363		switch (desc[0]) {
 364		case 0x02:
 365			rc = target_xcopy_parse_segdesc_02(xop, desc);
 366			if (rc < 0)
 367				goto out;
 368
 369			ret++;
 370			start += XCOPY_SEGMENT_DESC_LEN;
 371			desc += XCOPY_SEGMENT_DESC_LEN;
 372			break;
 373		default:
 374			pr_err("XCOPY unsupported segment descriptor"
 375				"type: 0x%02x\n", desc[0]);
 376			*sense_ret = TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE;
 377			goto out;
 378		}
 379	}
 380
 381	return ret;
 382
 383out:
 384	return -EINVAL;
 385}
 386
 387/*
 388 * Start xcopy_pt ops
 389 */
 390
 391struct xcopy_pt_cmd {
 392	struct se_cmd se_cmd;
 393	struct completion xpt_passthrough_sem;
 394	unsigned char sense_buffer[TRANSPORT_SENSE_BUFFER];
 395};
 396
 397struct se_portal_group xcopy_pt_tpg;
 398static struct se_session xcopy_pt_sess;
 399static struct se_node_acl xcopy_pt_nacl;
 400
 401static int xcopy_pt_get_cmd_state(struct se_cmd *se_cmd)
 402{
 403        return 0;
 404}
 405
 406static void xcopy_pt_undepend_remotedev(struct xcopy_op *xop)
 407{
 408	if (xop->op_origin == XCOL_SOURCE_RECV_OP)
 409		pr_debug("putting dst lun_ref for %p\n", xop->dst_dev);
 410	else
 411		pr_debug("putting src lun_ref for %p\n", xop->src_dev);
 412
 413	percpu_ref_put(xop->remote_lun_ref);
 414}
 415
 416static void xcopy_pt_release_cmd(struct se_cmd *se_cmd)
 417{
 418	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
 419				struct xcopy_pt_cmd, se_cmd);
 420
 421	/* xpt_cmd is on the stack, nothing to free here */
 422	pr_debug("xpt_cmd done: %p\n", xpt_cmd);
 423}
 424
 425static int xcopy_pt_check_stop_free(struct se_cmd *se_cmd)
 426{
 427	struct xcopy_pt_cmd *xpt_cmd = container_of(se_cmd,
 428				struct xcopy_pt_cmd, se_cmd);
 429
 430	complete(&xpt_cmd->xpt_passthrough_sem);
 431	return 0;
 432}
 433
 434static int xcopy_pt_write_pending(struct se_cmd *se_cmd)
 435{
 436	return 0;
 437}
 438
 439static int xcopy_pt_queue_data_in(struct se_cmd *se_cmd)
 440{
 441	return 0;
 442}
 443
 444static int xcopy_pt_queue_status(struct se_cmd *se_cmd)
 445{
 446	return 0;
 447}
 448
 449static const struct target_core_fabric_ops xcopy_pt_tfo = {
 450	.fabric_name		= "xcopy-pt",
 451	.get_cmd_state		= xcopy_pt_get_cmd_state,
 452	.release_cmd		= xcopy_pt_release_cmd,
 453	.check_stop_free	= xcopy_pt_check_stop_free,
 454	.write_pending		= xcopy_pt_write_pending,
 455	.queue_data_in		= xcopy_pt_queue_data_in,
 456	.queue_status		= xcopy_pt_queue_status,
 457};
 458
 459/*
 460 * End xcopy_pt_ops
 461 */
 462
 463int target_xcopy_setup_pt(void)
 464{
 465	xcopy_wq = alloc_workqueue("xcopy_wq", WQ_MEM_RECLAIM, 0);
 466	if (!xcopy_wq) {
 467		pr_err("Unable to allocate xcopy_wq\n");
 468		return -ENOMEM;
 469	}
 470
 471	memset(&xcopy_pt_tpg, 0, sizeof(struct se_portal_group));
 472	INIT_LIST_HEAD(&xcopy_pt_tpg.acl_node_list);
 473	INIT_LIST_HEAD(&xcopy_pt_tpg.tpg_sess_list);
 474
 475	xcopy_pt_tpg.se_tpg_tfo = &xcopy_pt_tfo;
 476
 477	memset(&xcopy_pt_nacl, 0, sizeof(struct se_node_acl));
 478	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_list);
 479	INIT_LIST_HEAD(&xcopy_pt_nacl.acl_sess_list);
 480	memset(&xcopy_pt_sess, 0, sizeof(struct se_session));
 481	transport_init_session(&xcopy_pt_sess);
 482
 483	xcopy_pt_nacl.se_tpg = &xcopy_pt_tpg;
 484	xcopy_pt_nacl.nacl_sess = &xcopy_pt_sess;
 485
 486	xcopy_pt_sess.se_tpg = &xcopy_pt_tpg;
 487	xcopy_pt_sess.se_node_acl = &xcopy_pt_nacl;
 488
 489	return 0;
 490}
 491
 492void target_xcopy_release_pt(void)
 493{
 494	if (xcopy_wq)
 495		destroy_workqueue(xcopy_wq);
 496}
 497
 498/*
 499 * target_xcopy_setup_pt_cmd - set up a pass-through command
 500 * @xpt_cmd:	 Data structure to initialize.
 501 * @xop:	 Describes the XCOPY operation received from an initiator.
 502 * @se_dev:	 Backend device to associate with @xpt_cmd if
 503 *		 @remote_port == true.
 504 * @cdb:	 SCSI CDB to be copied into @xpt_cmd.
 505 * @remote_port: If false, use the LUN through which the XCOPY command has
 506 *		 been received. If true, use @se_dev->xcopy_lun.
 507 *
 508 * Set up a SCSI command (READ or WRITE) that will be used to execute an
 509 * XCOPY command.
 510 */
 511static int target_xcopy_setup_pt_cmd(
 512	struct xcopy_pt_cmd *xpt_cmd,
 513	struct xcopy_op *xop,
 514	struct se_device *se_dev,
 515	unsigned char *cdb,
 516	bool remote_port)
 517{
 518	struct se_cmd *cmd = &xpt_cmd->se_cmd;
 519
 520	/*
 521	 * Setup LUN+port to honor reservations based upon xop->op_origin for
 522	 * X-COPY PUSH or X-COPY PULL based upon where the CDB was received.
 523	 */
 524	if (remote_port) {
 525		cmd->se_lun = &se_dev->xcopy_lun;
 526		cmd->se_dev = se_dev;
 527	} else {
 528		cmd->se_lun = xop->xop_se_cmd->se_lun;
 529		cmd->se_dev = xop->xop_se_cmd->se_dev;
 530	}
 531	cmd->se_cmd_flags |= SCF_SE_LUN_CMD;
 532
 533	if (target_cmd_init_cdb(cmd, cdb, GFP_KERNEL))
 534		return -EINVAL;
 535
 536	cmd->tag = 0;
 537	if (target_cmd_parse_cdb(cmd))
 538		return -EINVAL;
 539
 540	if (transport_generic_map_mem_to_cmd(cmd, xop->xop_data_sg,
 541					xop->xop_data_nents, NULL, 0))
 542		return -EINVAL;
 543
 544	pr_debug("Setup PASSTHROUGH_NOALLOC t_data_sg: %p t_data_nents:"
 545		 " %u\n", cmd->t_data_sg, cmd->t_data_nents);
 546
 547	return 0;
 548}
 549
 550static int target_xcopy_issue_pt_cmd(struct xcopy_pt_cmd *xpt_cmd)
 551{
 552	struct se_cmd *se_cmd = &xpt_cmd->se_cmd;
 553	sense_reason_t sense_rc;
 554
 555	sense_rc = transport_generic_new_cmd(se_cmd);
 556	if (sense_rc)
 557		return -EINVAL;
 558
 559	if (se_cmd->data_direction == DMA_TO_DEVICE)
 560		target_execute_cmd(se_cmd);
 561
 562	wait_for_completion_interruptible(&xpt_cmd->xpt_passthrough_sem);
 563
 564	pr_debug("target_xcopy_issue_pt_cmd(): SCSI status: 0x%02x\n",
 565			se_cmd->scsi_status);
 566
 567	return (se_cmd->scsi_status) ? -EINVAL : 0;
 568}
 569
 570static int target_xcopy_read_source(
 571	struct se_cmd *ec_cmd,
 572	struct xcopy_op *xop,
 573	struct se_device *src_dev,
 574	sector_t src_lba,
 575	u32 src_bytes)
 576{
 577	struct xcopy_pt_cmd xpt_cmd;
 578	struct se_cmd *se_cmd = &xpt_cmd.se_cmd;
 579	u32 transfer_length_block = src_bytes / src_dev->dev_attrib.block_size;
 580	int rc;
 581	unsigned char cdb[16];
 582	bool remote_port = (xop->op_origin == XCOL_DEST_RECV_OP);
 583
 584	memset(&xpt_cmd, 0, sizeof(xpt_cmd));
 585	init_completion(&xpt_cmd.xpt_passthrough_sem);
 586
 587	memset(&cdb[0], 0, 16);
 588	cdb[0] = READ_16;
 589	put_unaligned_be64(src_lba, &cdb[2]);
 590	put_unaligned_be32(transfer_length_block, &cdb[10]);
 591	pr_debug("XCOPY: Built READ_16: LBA: %llu Blocks: %u Length: %u\n",
 592		(unsigned long long)src_lba, transfer_length_block, src_bytes);
 593
 594	__target_init_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, src_bytes,
 595			  DMA_FROM_DEVICE, 0, &xpt_cmd.sense_buffer[0], 0,
 596			  NULL);
 597	rc = target_xcopy_setup_pt_cmd(&xpt_cmd, xop, src_dev, &cdb[0],
 598				remote_port);
 599	if (rc < 0) {
 600		ec_cmd->scsi_status = se_cmd->scsi_status;
 601		goto out;
 602	}
 603
 604	pr_debug("XCOPY-READ: Saved xop->xop_data_sg: %p, num: %u for READ"
 605		" memory\n", xop->xop_data_sg, xop->xop_data_nents);
 606
 607	rc = target_xcopy_issue_pt_cmd(&xpt_cmd);
 608	if (rc < 0)
 609		ec_cmd->scsi_status = se_cmd->scsi_status;
 610out:
 611	transport_generic_free_cmd(se_cmd, 0);
 612	return rc;
 613}
 614
 615static int target_xcopy_write_destination(
 616	struct se_cmd *ec_cmd,
 617	struct xcopy_op *xop,
 618	struct se_device *dst_dev,
 619	sector_t dst_lba,
 620	u32 dst_bytes)
 621{
 622	struct xcopy_pt_cmd xpt_cmd;
 623	struct se_cmd *se_cmd = &xpt_cmd.se_cmd;
 624	u32 transfer_length_block = dst_bytes / dst_dev->dev_attrib.block_size;
 625	int rc;
 626	unsigned char cdb[16];
 627	bool remote_port = (xop->op_origin == XCOL_SOURCE_RECV_OP);
 628
 629	memset(&xpt_cmd, 0, sizeof(xpt_cmd));
 630	init_completion(&xpt_cmd.xpt_passthrough_sem);
 631
 632	memset(&cdb[0], 0, 16);
 633	cdb[0] = WRITE_16;
 634	put_unaligned_be64(dst_lba, &cdb[2]);
 635	put_unaligned_be32(transfer_length_block, &cdb[10]);
 636	pr_debug("XCOPY: Built WRITE_16: LBA: %llu Blocks: %u Length: %u\n",
 637		(unsigned long long)dst_lba, transfer_length_block, dst_bytes);
 638
 639	__target_init_cmd(se_cmd, &xcopy_pt_tfo, &xcopy_pt_sess, dst_bytes,
 640			  DMA_TO_DEVICE, 0, &xpt_cmd.sense_buffer[0], 0,
 641			  NULL);
 642	rc = target_xcopy_setup_pt_cmd(&xpt_cmd, xop, dst_dev, &cdb[0],
 643				remote_port);
 644	if (rc < 0) {
 645		ec_cmd->scsi_status = se_cmd->scsi_status;
 646		goto out;
 647	}
 648
 649	rc = target_xcopy_issue_pt_cmd(&xpt_cmd);
 650	if (rc < 0)
 651		ec_cmd->scsi_status = se_cmd->scsi_status;
 652out:
 653	transport_generic_free_cmd(se_cmd, 0);
 654	return rc;
 655}
 656
 657static void target_xcopy_do_work(struct work_struct *work)
 658{
 659	struct xcopy_op *xop = container_of(work, struct xcopy_op, xop_work);
 660	struct se_cmd *ec_cmd = xop->xop_se_cmd;
 661	struct se_device *src_dev, *dst_dev;
 662	sector_t src_lba, dst_lba, end_lba;
 663	unsigned long long max_bytes, max_bytes_src, max_bytes_dst, max_blocks;
 664	int rc = 0;
 665	unsigned short nolb;
 666	unsigned int copied_bytes = 0;
 667	sense_reason_t sense_rc;
 668
 669	sense_rc = target_parse_xcopy_cmd(xop);
 670	if (sense_rc != TCM_NO_SENSE)
 671		goto err_free;
 672
 673	if (WARN_ON_ONCE(!xop->src_dev) || WARN_ON_ONCE(!xop->dst_dev)) {
 674		sense_rc = TCM_INVALID_PARAMETER_LIST;
 675		goto err_free;
 676	}
 677
 678	src_dev = xop->src_dev;
 679	dst_dev = xop->dst_dev;
 680	src_lba = xop->src_lba;
 681	dst_lba = xop->dst_lba;
 682	nolb = xop->nolb;
 683	end_lba = src_lba + nolb;
 684	/*
 685	 * Break up XCOPY I/O into hw_max_sectors * hw_block_size sized
 686	 * I/O based on the smallest max_bytes between src_dev + dst_dev
 687	 */
 688	max_bytes_src = (unsigned long long) src_dev->dev_attrib.hw_max_sectors *
 689			src_dev->dev_attrib.hw_block_size;
 690	max_bytes_dst = (unsigned long long) dst_dev->dev_attrib.hw_max_sectors *
 691			dst_dev->dev_attrib.hw_block_size;
 692
 693	max_bytes = min_t(u64, max_bytes_src, max_bytes_dst);
 694	max_bytes = min_t(u64, max_bytes, XCOPY_MAX_BYTES);
 695
 696	/*
 697	 * Using shift instead of the division because otherwise GCC
 698	 * generates __udivdi3 that is missing on i386
 699	 */
 700	max_blocks = max_bytes >> ilog2(src_dev->dev_attrib.block_size);
 701
 702	pr_debug("%s: nolb: %u, max_blocks: %llu end_lba: %llu\n", __func__,
 703			nolb, max_blocks, (unsigned long long)end_lba);
 704	pr_debug("%s: Starting src_lba: %llu, dst_lba: %llu\n", __func__,
 705			(unsigned long long)src_lba, (unsigned long long)dst_lba);
 706
 707	while (nolb) {
 708		u32 cur_bytes = min_t(u64, max_bytes, nolb * src_dev->dev_attrib.block_size);
 709		unsigned short cur_nolb = cur_bytes / src_dev->dev_attrib.block_size;
 710
 711		if (cur_bytes != xop->xop_data_bytes) {
 712			/*
 713			 * (Re)allocate a buffer large enough to hold the XCOPY
 714			 * I/O size, which can be reused each read / write loop.
 715			 */
 716			target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
 717			rc = target_alloc_sgl(&xop->xop_data_sg,
 718					      &xop->xop_data_nents,
 719					      cur_bytes,
 720					      false, false);
 721			if (rc < 0)
 722				goto out;
 723			xop->xop_data_bytes = cur_bytes;
 724		}
 725
 726		pr_debug("%s: Calling read src_dev: %p src_lba: %llu, cur_nolb: %hu\n",
 727				__func__, src_dev, (unsigned long long)src_lba, cur_nolb);
 728
 729		rc = target_xcopy_read_source(ec_cmd, xop, src_dev, src_lba, cur_bytes);
 730		if (rc < 0)
 731			goto out;
 732
 733		src_lba += cur_bytes / src_dev->dev_attrib.block_size;
 734		pr_debug("%s: Incremented READ src_lba to %llu\n", __func__,
 735				(unsigned long long)src_lba);
 736
 737		pr_debug("%s: Calling write dst_dev: %p dst_lba: %llu, cur_nolb: %u\n",
 738				__func__, dst_dev, (unsigned long long)dst_lba, cur_nolb);
 739
 740		rc = target_xcopy_write_destination(ec_cmd, xop, dst_dev,
 741						dst_lba, cur_bytes);
 742		if (rc < 0)
 743			goto out;
 744
 745		dst_lba += cur_bytes / dst_dev->dev_attrib.block_size;
 746		pr_debug("%s: Incremented WRITE dst_lba to %llu\n", __func__,
 747				(unsigned long long)dst_lba);
 748
 749		copied_bytes += cur_bytes;
 750		nolb -= cur_bytes / src_dev->dev_attrib.block_size;
 751	}
 752
 753	xcopy_pt_undepend_remotedev(xop);
 754	target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
 755	kfree(xop);
 756
 757	pr_debug("%s: Final src_lba: %llu, dst_lba: %llu\n", __func__,
 758		(unsigned long long)src_lba, (unsigned long long)dst_lba);
 759	pr_debug("%s: Blocks copied: %u, Bytes Copied: %u\n", __func__,
 760		copied_bytes / dst_dev->dev_attrib.block_size, copied_bytes);
 761
 762	pr_debug("%s: Setting X-COPY GOOD status -> sending response\n", __func__);
 763	target_complete_cmd(ec_cmd, SAM_STAT_GOOD);
 764	return;
 765
 766out:
 767	/*
 768	 * The XCOPY command was aborted after some data was transferred.
 769	 * Terminate command with CHECK CONDITION status, with the sense key
 770	 * set to COPY ABORTED.
 771	 */
 772	sense_rc = TCM_COPY_TARGET_DEVICE_NOT_REACHABLE;
 773	xcopy_pt_undepend_remotedev(xop);
 774	target_free_sgl(xop->xop_data_sg, xop->xop_data_nents);
 775
 776err_free:
 777	kfree(xop);
 778	pr_warn_ratelimited("%s: rc: %d, sense: %u, XCOPY operation failed\n",
 779			   __func__, rc, sense_rc);
 780	target_complete_cmd_with_sense(ec_cmd, SAM_STAT_CHECK_CONDITION, sense_rc);
 781}
 782
 783/*
 784 * Returns TCM_NO_SENSE upon success or a sense code != TCM_NO_SENSE if parsing
 785 * fails.
 786 */
 787static sense_reason_t target_parse_xcopy_cmd(struct xcopy_op *xop)
 788{
 789	struct se_cmd *se_cmd = xop->xop_se_cmd;
 790	unsigned char *p = NULL, *seg_desc;
 791	unsigned int list_id, list_id_usage, sdll, inline_dl;
 792	sense_reason_t ret = TCM_INVALID_PARAMETER_LIST;
 793	int rc;
 794	unsigned short tdll;
 795
 796	p = transport_kmap_data_sg(se_cmd);
 797	if (!p) {
 798		pr_err("transport_kmap_data_sg() failed in target_do_xcopy\n");
 799		return TCM_OUT_OF_RESOURCES;
 800	}
 801
 802	list_id = p[0];
 803	list_id_usage = (p[1] & 0x18) >> 3;
 804
 805	/*
 806	 * Determine TARGET DESCRIPTOR LIST LENGTH + SEGMENT DESCRIPTOR LIST LENGTH
 807	 */
 808	tdll = get_unaligned_be16(&p[2]);
 809	sdll = get_unaligned_be32(&p[8]);
 810	if (tdll + sdll > RCR_OP_MAX_DESC_LIST_LEN) {
 811		pr_err("XCOPY descriptor list length %u exceeds maximum %u\n",
 812		       tdll + sdll, RCR_OP_MAX_DESC_LIST_LEN);
 813		ret = TCM_PARAMETER_LIST_LENGTH_ERROR;
 814		goto out;
 815	}
 816
 817	inline_dl = get_unaligned_be32(&p[12]);
 818	if (inline_dl != 0) {
 819		pr_err("XCOPY with non zero inline data length\n");
 820		goto out;
 821	}
 822
 823	if (se_cmd->data_length < (XCOPY_HDR_LEN + tdll + sdll + inline_dl)) {
 824		pr_err("XCOPY parameter truncation: data length %u too small "
 825			"for tdll: %hu sdll: %u inline_dl: %u\n",
 826			se_cmd->data_length, tdll, sdll, inline_dl);
 827		ret = TCM_PARAMETER_LIST_LENGTH_ERROR;
 828		goto out;
 829	}
 830
 831	pr_debug("Processing XCOPY with list_id: 0x%02x list_id_usage: 0x%02x"
 832		" tdll: %hu sdll: %u inline_dl: %u\n", list_id, list_id_usage,
 833		tdll, sdll, inline_dl);
 834
 835	/*
 836	 * skip over the target descriptors until segment descriptors
 837	 * have been passed - CSCD ids are needed to determine src and dest.
 838	 */
 839	seg_desc = &p[16] + tdll;
 840
 841	rc = target_xcopy_parse_segment_descriptors(xop, seg_desc, sdll, &ret);
 842	if (rc <= 0)
 843		goto out;
 844
 845	pr_debug("XCOPY: Processed %d segment descriptors, length: %u\n", rc,
 846				rc * XCOPY_SEGMENT_DESC_LEN);
 847
 848	rc = target_xcopy_parse_target_descriptors(se_cmd, xop, &p[16], tdll, &ret);
 849	if (rc <= 0)
 850		goto out;
 851
 852	if (xop->src_dev->dev_attrib.block_size !=
 853	    xop->dst_dev->dev_attrib.block_size) {
 854		pr_err("XCOPY: Non matching src_dev block_size: %u + dst_dev"
 855		       " block_size: %u currently unsupported\n",
 856			xop->src_dev->dev_attrib.block_size,
 857			xop->dst_dev->dev_attrib.block_size);
 858		xcopy_pt_undepend_remotedev(xop);
 859		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 860		goto out;
 861	}
 862
 863	pr_debug("XCOPY: Processed %d target descriptors, length: %u\n", rc,
 864				rc * XCOPY_TARGET_DESC_LEN);
 865	transport_kunmap_data_sg(se_cmd);
 866	return TCM_NO_SENSE;
 867
 868out:
 869	if (p)
 870		transport_kunmap_data_sg(se_cmd);
 871	return ret;
 872}
 873
 874sense_reason_t target_do_xcopy(struct se_cmd *se_cmd)
 875{
 876	struct se_device *dev = se_cmd->se_dev;
 877	struct xcopy_op *xop;
 878	unsigned int sa;
 879
 880	if (!dev->dev_attrib.emulate_3pc) {
 881		pr_err("EXTENDED_COPY operation explicitly disabled\n");
 882		return TCM_UNSUPPORTED_SCSI_OPCODE;
 883	}
 884
 885	sa = se_cmd->t_task_cdb[1] & 0x1f;
 886	if (sa != 0x00) {
 887		pr_err("EXTENDED_COPY(LID4) not supported\n");
 888		return TCM_UNSUPPORTED_SCSI_OPCODE;
 889	}
 890
 891	if (se_cmd->data_length == 0) {
 892		target_complete_cmd(se_cmd, SAM_STAT_GOOD);
 893		return TCM_NO_SENSE;
 894	}
 895	if (se_cmd->data_length < XCOPY_HDR_LEN) {
 896		pr_err("XCOPY parameter truncation: length %u < hdr_len %u\n",
 897				se_cmd->data_length, XCOPY_HDR_LEN);
 898		return TCM_PARAMETER_LIST_LENGTH_ERROR;
 899	}
 900
 901	xop = kzalloc(sizeof(struct xcopy_op), GFP_KERNEL);
 902	if (!xop)
 903		goto err;
 904	xop->xop_se_cmd = se_cmd;
 905	INIT_WORK(&xop->xop_work, target_xcopy_do_work);
 906	if (WARN_ON_ONCE(!queue_work(xcopy_wq, &xop->xop_work)))
 907		goto free;
 908	return TCM_NO_SENSE;
 909
 910free:
 911	kfree(xop);
 912
 913err:
 914	return TCM_OUT_OF_RESOURCES;
 915}
 916
 917static sense_reason_t target_rcr_operating_parameters(struct se_cmd *se_cmd)
 918{
 919	unsigned char *p;
 920
 921	p = transport_kmap_data_sg(se_cmd);
 922	if (!p) {
 923		pr_err("transport_kmap_data_sg failed in"
 924		       " target_rcr_operating_parameters\n");
 925		return TCM_OUT_OF_RESOURCES;
 926	}
 927
 928	if (se_cmd->data_length < 54) {
 929		pr_err("Receive Copy Results Op Parameters length"
 930		       " too small: %u\n", se_cmd->data_length);
 931		transport_kunmap_data_sg(se_cmd);
 932		return TCM_INVALID_CDB_FIELD;
 933	}
 934	/*
 935	 * Set SNLID=1 (Supports no List ID)
 936	 */
 937	p[4] = 0x1;
 938	/*
 939	 * MAXIMUM TARGET DESCRIPTOR COUNT
 940	 */
 941	put_unaligned_be16(RCR_OP_MAX_TARGET_DESC_COUNT, &p[8]);
 942	/*
 943	 * MAXIMUM SEGMENT DESCRIPTOR COUNT
 944	 */
 945	put_unaligned_be16(RCR_OP_MAX_SG_DESC_COUNT, &p[10]);
 946	/*
 947	 * MAXIMUM DESCRIPTOR LIST LENGTH
 948	 */
 949	put_unaligned_be32(RCR_OP_MAX_DESC_LIST_LEN, &p[12]);
 950	/*
 951	 * MAXIMUM SEGMENT LENGTH
 952	 */
 953	put_unaligned_be32(RCR_OP_MAX_SEGMENT_LEN, &p[16]);
 954	/*
 955	 * MAXIMUM INLINE DATA LENGTH for SA 0x04 (NOT SUPPORTED)
 956	 */
 957	put_unaligned_be32(0x0, &p[20]);
 958	/*
 959	 * HELD DATA LIMIT
 960	 */
 961	put_unaligned_be32(0x0, &p[24]);
 962	/*
 963	 * MAXIMUM STREAM DEVICE TRANSFER SIZE
 964	 */
 965	put_unaligned_be32(0x0, &p[28]);
 966	/*
 967	 * TOTAL CONCURRENT COPIES
 968	 */
 969	put_unaligned_be16(RCR_OP_TOTAL_CONCURR_COPIES, &p[34]);
 970	/*
 971	 * MAXIMUM CONCURRENT COPIES
 972	 */
 973	p[36] = RCR_OP_MAX_CONCURR_COPIES;
 974	/*
 975	 * DATA SEGMENT GRANULARITY (log 2)
 976	 */
 977	p[37] = RCR_OP_DATA_SEG_GRAN_LOG2;
 978	/*
 979	 * INLINE DATA GRANULARITY log 2)
 980	 */
 981	p[38] = RCR_OP_INLINE_DATA_GRAN_LOG2;
 982	/*
 983	 * HELD DATA GRANULARITY
 984	 */
 985	p[39] = RCR_OP_HELD_DATA_GRAN_LOG2;
 986	/*
 987	 * IMPLEMENTED DESCRIPTOR LIST LENGTH
 988	 */
 989	p[43] = 0x2;
 990	/*
 991	 * List of implemented descriptor type codes (ordered)
 992	 */
 993	p[44] = 0x02; /* Copy Block to Block device */
 994	p[45] = 0xe4; /* Identification descriptor target descriptor */
 995
 996	/*
 997	 * AVAILABLE DATA (n-3)
 998	 */
 999	put_unaligned_be32(42, &p[0]);
1000
1001	transport_kunmap_data_sg(se_cmd);
1002	target_complete_cmd(se_cmd, SAM_STAT_GOOD);
1003
1004	return TCM_NO_SENSE;
1005}
1006
1007sense_reason_t target_do_receive_copy_results(struct se_cmd *se_cmd)
1008{
1009	unsigned char *cdb = &se_cmd->t_task_cdb[0];
1010	int sa = (cdb[1] & 0x1f), list_id = cdb[2];
1011	struct se_device *dev = se_cmd->se_dev;
1012	sense_reason_t rc = TCM_NO_SENSE;
1013
1014	if (!dev->dev_attrib.emulate_3pc) {
1015		pr_debug("Third-party copy operations explicitly disabled\n");
1016		return TCM_UNSUPPORTED_SCSI_OPCODE;
1017	}
1018
1019	pr_debug("Entering target_do_receive_copy_results: SA: 0x%02x, List ID:"
1020		" 0x%02x, AL: %u\n", sa, list_id, se_cmd->data_length);
1021
1022	if (list_id != 0) {
1023		pr_err("Receive Copy Results with non zero list identifier"
1024		       " not supported\n");
1025		return TCM_INVALID_CDB_FIELD;
1026	}
1027
1028	switch (sa) {
1029	case RCR_SA_OPERATING_PARAMETERS:
1030		rc = target_rcr_operating_parameters(se_cmd);
1031		break;
1032	case RCR_SA_COPY_STATUS:
1033	case RCR_SA_RECEIVE_DATA:
1034	case RCR_SA_FAILED_SEGMENT_DETAILS:
1035	default:
1036		pr_err("Unsupported SA for receive copy results: 0x%02x\n", sa);
1037		return TCM_INVALID_CDB_FIELD;
1038	}
1039
1040	return rc;
1041}