1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*******************************************************************************
   3 * Filename:  target_core_alua.c
   4 *
   5 * This file contains SPC-3 compliant asymmetric logical unit assigntment (ALUA)
   6 *
   7 * (c) Copyright 2009-2013 Datera, Inc.
   8 *
   9 * Nicholas A. Bellinger <nab@kernel.org>
  10 *
  11 ******************************************************************************/
  12
  13#include <linux/slab.h>
  14#include <linux/spinlock.h>
  15#include <linux/configfs.h>
  16#include <linux/delay.h>
  17#include <linux/export.h>
  18#include <linux/fcntl.h>
  19#include <linux/file.h>
  20#include <linux/fs.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_alua.h"
  30#include "target_core_ua.h"
  31
  32static sense_reason_t core_alua_check_transition(int state, int valid,
  33						 int *primary, int explicit);
  34static int core_alua_set_tg_pt_secondary_state(
  35		struct se_lun *lun, int explicit, int offline);
  36
  37static char *core_alua_dump_state(int state);
  38
  39static void __target_attach_tg_pt_gp(struct se_lun *lun,
  40		struct t10_alua_tg_pt_gp *tg_pt_gp);
  41
  42static u16 alua_lu_gps_counter;
  43static u32 alua_lu_gps_count;
  44
  45static DEFINE_SPINLOCK(lu_gps_lock);
  46static LIST_HEAD(lu_gps_list);
  47
  48struct t10_alua_lu_gp *default_lu_gp;
  49
  50/*
  51 * REPORT REFERRALS
  52 *
  53 * See sbc3r35 section 5.23
  54 */
  55sense_reason_t
  56target_emulate_report_referrals(struct se_cmd *cmd)
  57{
  58	struct se_device *dev = cmd->se_dev;
  59	struct t10_alua_lba_map *map;
  60	struct t10_alua_lba_map_member *map_mem;
  61	unsigned char *buf;
  62	u32 rd_len = 0, off;
  63
  64	if (cmd->data_length < 4) {
  65		pr_warn("REPORT REFERRALS allocation length %u too"
  66			" small\n", cmd->data_length);
  67		return TCM_INVALID_CDB_FIELD;
  68	}
  69
  70	buf = transport_kmap_data_sg(cmd);
  71	if (!buf)
  72		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
  73
  74	off = 4;
  75	spin_lock(&dev->t10_alua.lba_map_lock);
  76	if (list_empty(&dev->t10_alua.lba_map_list)) {
  77		spin_unlock(&dev->t10_alua.lba_map_lock);
  78		transport_kunmap_data_sg(cmd);
  79
  80		return TCM_UNSUPPORTED_SCSI_OPCODE;
  81	}
  82
  83	list_for_each_entry(map, &dev->t10_alua.lba_map_list,
  84			    lba_map_list) {
  85		int desc_num = off + 3;
  86		int pg_num;
  87
  88		off += 4;
  89		if (cmd->data_length > off)
  90			put_unaligned_be64(map->lba_map_first_lba, &buf[off]);
  91		off += 8;
  92		if (cmd->data_length > off)
  93			put_unaligned_be64(map->lba_map_last_lba, &buf[off]);
  94		off += 8;
  95		rd_len += 20;
  96		pg_num = 0;
  97		list_for_each_entry(map_mem, &map->lba_map_mem_list,
  98				    lba_map_mem_list) {
  99			int alua_state = map_mem->lba_map_mem_alua_state;
 100			int alua_pg_id = map_mem->lba_map_mem_alua_pg_id;
 101
 102			if (cmd->data_length > off)
 103				buf[off] = alua_state & 0x0f;
 104			off += 2;
 105			if (cmd->data_length > off)
 106				buf[off] = (alua_pg_id >> 8) & 0xff;
 107			off++;
 108			if (cmd->data_length > off)
 109				buf[off] = (alua_pg_id & 0xff);
 110			off++;
 111			rd_len += 4;
 112			pg_num++;
 113		}
 114		if (cmd->data_length > desc_num)
 115			buf[desc_num] = pg_num;
 116	}
 117	spin_unlock(&dev->t10_alua.lba_map_lock);
 118
 119	/*
 120	 * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
 121	 */
 122	put_unaligned_be16(rd_len, &buf[2]);
 123
 124	transport_kunmap_data_sg(cmd);
 125
 126	target_complete_cmd(cmd, SAM_STAT_GOOD);
 127	return 0;
 128}
 129
 130/*
 131 * REPORT_TARGET_PORT_GROUPS
 132 *
 133 * See spc4r17 section 6.27
 134 */
 135sense_reason_t
 136target_emulate_report_target_port_groups(struct se_cmd *cmd)
 137{
 138	struct se_device *dev = cmd->se_dev;
 139	struct t10_alua_tg_pt_gp *tg_pt_gp;
 140	struct se_lun *lun;
 141	unsigned char *buf;
 142	u32 rd_len = 0, off;
 143	int ext_hdr = (cmd->t_task_cdb[1] & 0x20);
 144
 145	/*
 146	 * Skip over RESERVED area to first Target port group descriptor
 147	 * depending on the PARAMETER DATA FORMAT type..
 148	 */
 149	if (ext_hdr != 0)
 150		off = 8;
 151	else
 152		off = 4;
 153
 154	if (cmd->data_length < off) {
 155		pr_warn("REPORT TARGET PORT GROUPS allocation length %u too"
 156			" small for %s header\n", cmd->data_length,
 157			(ext_hdr) ? "extended" : "normal");
 158		return TCM_INVALID_CDB_FIELD;
 159	}
 160	buf = transport_kmap_data_sg(cmd);
 161	if (!buf)
 162		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 163
 164	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
 165	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
 166			tg_pt_gp_list) {
 167		/* Skip empty port groups */
 168		if (!tg_pt_gp->tg_pt_gp_members)
 169			continue;
 170		/*
 171		 * Check if the Target port group and Target port descriptor list
 172		 * based on tg_pt_gp_members count will fit into the response payload.
 173		 * Otherwise, bump rd_len to let the initiator know we have exceeded
 174		 * the allocation length and the response is truncated.
 175		 */
 176		if ((off + 8 + (tg_pt_gp->tg_pt_gp_members * 4)) >
 177		     cmd->data_length) {
 178			rd_len += 8 + (tg_pt_gp->tg_pt_gp_members * 4);
 179			continue;
 180		}
 181		/*
 182		 * PREF: Preferred target port bit, determine if this
 183		 * bit should be set for port group.
 184		 */
 185		if (tg_pt_gp->tg_pt_gp_pref)
 186			buf[off] = 0x80;
 187		/*
 188		 * Set the ASYMMETRIC ACCESS State
 189		 */
 190		buf[off++] |= tg_pt_gp->tg_pt_gp_alua_access_state & 0xff;
 191		/*
 192		 * Set supported ASYMMETRIC ACCESS State bits
 193		 */
 194		buf[off++] |= tg_pt_gp->tg_pt_gp_alua_supported_states;
 195		/*
 196		 * TARGET PORT GROUP
 197		 */
 198		put_unaligned_be16(tg_pt_gp->tg_pt_gp_id, &buf[off]);
 199		off += 2;
 200
 201		off++; /* Skip over Reserved */
 202		/*
 203		 * STATUS CODE
 204		 */
 205		buf[off++] = (tg_pt_gp->tg_pt_gp_alua_access_status & 0xff);
 206		/*
 207		 * Vendor Specific field
 208		 */
 209		buf[off++] = 0x00;
 210		/*
 211		 * TARGET PORT COUNT
 212		 */
 213		buf[off++] = (tg_pt_gp->tg_pt_gp_members & 0xff);
 214		rd_len += 8;
 215
 216		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 217		list_for_each_entry(lun, &tg_pt_gp->tg_pt_gp_lun_list,
 218				lun_tg_pt_gp_link) {
 219			/*
 220			 * Start Target Port descriptor format
 221			 *
 222			 * See spc4r17 section 6.2.7 Table 247
 223			 */
 224			off += 2; /* Skip over Obsolete */
 225			/*
 226			 * Set RELATIVE TARGET PORT IDENTIFIER
 227			 */
 228			put_unaligned_be16(lun->lun_rtpi, &buf[off]);
 229			off += 2;
 230			rd_len += 4;
 231		}
 232		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 233	}
 234	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
 235	/*
 236	 * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
 237	 */
 238	put_unaligned_be32(rd_len, &buf[0]);
 239
 240	/*
 241	 * Fill in the Extended header parameter data format if requested
 242	 */
 243	if (ext_hdr != 0) {
 244		buf[4] = 0x10;
 245		/*
 246		 * Set the implicit transition time (in seconds) for the application
 247		 * client to use as a base for it's transition timeout value.
 248		 *
 249		 * Use the current tg_pt_gp_mem -> tg_pt_gp membership from the LUN
 250		 * this CDB was received upon to determine this value individually
 251		 * for ALUA target port group.
 252		 */
 253		rcu_read_lock();
 254		tg_pt_gp = rcu_dereference(cmd->se_lun->lun_tg_pt_gp);
 255		if (tg_pt_gp)
 256			buf[5] = tg_pt_gp->tg_pt_gp_implicit_trans_secs;
 257		rcu_read_unlock();
 258	}
 259	transport_kunmap_data_sg(cmd);
 260
 261	target_complete_cmd_with_length(cmd, SAM_STAT_GOOD, rd_len + 4);
 262	return 0;
 263}
 264
 265/*
 266 * SET_TARGET_PORT_GROUPS for explicit ALUA operation.
 267 *
 268 * See spc4r17 section 6.35
 269 */
 270sense_reason_t
 271target_emulate_set_target_port_groups(struct se_cmd *cmd)
 272{
 273	struct se_device *dev = cmd->se_dev;
 274	struct se_lun *l_lun = cmd->se_lun;
 275	struct se_node_acl *nacl = cmd->se_sess->se_node_acl;
 276	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *l_tg_pt_gp;
 277	unsigned char *buf;
 278	unsigned char *ptr;
 279	sense_reason_t rc = TCM_NO_SENSE;
 280	u32 len = 4; /* Skip over RESERVED area in header */
 281	int alua_access_state, primary = 0, valid_states;
 282	u16 tg_pt_id, rtpi;
 283
 284	if (cmd->data_length < 4) {
 285		pr_warn("SET TARGET PORT GROUPS parameter list length %u too"
 286			" small\n", cmd->data_length);
 287		return TCM_INVALID_PARAMETER_LIST;
 288	}
 289
 290	buf = transport_kmap_data_sg(cmd);
 291	if (!buf)
 292		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
 293
 294	/*
 295	 * Determine if explicit ALUA via SET_TARGET_PORT_GROUPS is allowed
 296	 * for the local tg_pt_gp.
 297	 */
 298	rcu_read_lock();
 299	l_tg_pt_gp = rcu_dereference(l_lun->lun_tg_pt_gp);
 300	if (!l_tg_pt_gp) {
 301		rcu_read_unlock();
 302		pr_err("Unable to access l_lun->tg_pt_gp\n");
 303		rc = TCM_UNSUPPORTED_SCSI_OPCODE;
 304		goto out;
 305	}
 306
 307	if (!(l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)) {
 308		rcu_read_unlock();
 309		pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
 310				" while TPGS_EXPLICIT_ALUA is disabled\n");
 311		rc = TCM_UNSUPPORTED_SCSI_OPCODE;
 312		goto out;
 313	}
 314	valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
 315	rcu_read_unlock();
 316
 317	ptr = &buf[4]; /* Skip over RESERVED area in header */
 318
 319	while (len < cmd->data_length) {
 320		bool found = false;
 321		alua_access_state = (ptr[0] & 0x0f);
 322		/*
 323		 * Check the received ALUA access state, and determine if
 324		 * the state is a primary or secondary target port asymmetric
 325		 * access state.
 326		 */
 327		rc = core_alua_check_transition(alua_access_state, valid_states,
 328						&primary, 1);
 329		if (rc) {
 330			/*
 331			 * If the SET TARGET PORT GROUPS attempts to establish
 332			 * an invalid combination of target port asymmetric
 333			 * access states or attempts to establish an
 334			 * unsupported target port asymmetric access state,
 335			 * then the command shall be terminated with CHECK
 336			 * CONDITION status, with the sense key set to ILLEGAL
 337			 * REQUEST, and the additional sense code set to INVALID
 338			 * FIELD IN PARAMETER LIST.
 339			 */
 340			goto out;
 341		}
 342
 343		/*
 344		 * If the ASYMMETRIC ACCESS STATE field (see table 267)
 345		 * specifies a primary target port asymmetric access state,
 346		 * then the TARGET PORT GROUP OR TARGET PORT field specifies
 347		 * a primary target port group for which the primary target
 348		 * port asymmetric access state shall be changed. If the
 349		 * ASYMMETRIC ACCESS STATE field specifies a secondary target
 350		 * port asymmetric access state, then the TARGET PORT GROUP OR
 351		 * TARGET PORT field specifies the relative target port
 352		 * identifier (see 3.1.120) of the target port for which the
 353		 * secondary target port asymmetric access state shall be
 354		 * changed.
 355		 */
 356		if (primary) {
 357			tg_pt_id = get_unaligned_be16(ptr + 2);
 358			/*
 359			 * Locate the matching target port group ID from
 360			 * the global tg_pt_gp list
 361			 */
 362			spin_lock(&dev->t10_alua.tg_pt_gps_lock);
 363			list_for_each_entry(tg_pt_gp,
 364					&dev->t10_alua.tg_pt_gps_list,
 365					tg_pt_gp_list) {
 366				if (!tg_pt_gp->tg_pt_gp_valid_id)
 367					continue;
 368
 369				if (tg_pt_id != tg_pt_gp->tg_pt_gp_id)
 370					continue;
 371
 372				atomic_inc_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
 373
 374				spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
 375
 376				if (!core_alua_do_port_transition(tg_pt_gp,
 377						dev, l_lun, nacl,
 378						alua_access_state, 1))
 379					found = true;
 380
 381				spin_lock(&dev->t10_alua.tg_pt_gps_lock);
 382				atomic_dec_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
 383				break;
 384			}
 385			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
 386		} else {
 387			struct se_lun *lun;
 388
 389			/*
 390			 * Extract the RELATIVE TARGET PORT IDENTIFIER to identify
 391			 * the Target Port in question for the incoming
 392			 * SET_TARGET_PORT_GROUPS op.
 393			 */
 394			rtpi = get_unaligned_be16(ptr + 2);
 395			/*
 396			 * Locate the matching relative target port identifier
 397			 * for the struct se_device storage object.
 398			 */
 399			spin_lock(&dev->se_port_lock);
 400			list_for_each_entry(lun, &dev->dev_sep_list,
 401							lun_dev_link) {
 402				if (lun->lun_rtpi != rtpi)
 403					continue;
 404
 405				// XXX: racy unlock
 406				spin_unlock(&dev->se_port_lock);
 407
 408				if (!core_alua_set_tg_pt_secondary_state(
 409						lun, 1, 1))
 410					found = true;
 411
 412				spin_lock(&dev->se_port_lock);
 413				break;
 414			}
 415			spin_unlock(&dev->se_port_lock);
 416		}
 417
 418		if (!found) {
 419			rc = TCM_INVALID_PARAMETER_LIST;
 420			goto out;
 421		}
 422
 423		ptr += 4;
 424		len += 4;
 425	}
 426
 427out:
 428	transport_kunmap_data_sg(cmd);
 429	if (!rc)
 430		target_complete_cmd(cmd, SAM_STAT_GOOD);
 431	return rc;
 432}
 433
 434static inline void core_alua_state_nonoptimized(
 435	struct se_cmd *cmd,
 436	unsigned char *cdb,
 437	int nonop_delay_msecs)
 438{
 439	/*
 440	 * Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
 441	 * later to determine if processing of this cmd needs to be
 442	 * temporarily delayed for the Active/NonOptimized primary access state.
 443	 */
 444	cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
 445	cmd->alua_nonop_delay = nonop_delay_msecs;
 446}
 447
 448static inline sense_reason_t core_alua_state_lba_dependent(
 449	struct se_cmd *cmd,
 450	u16 tg_pt_gp_id)
 451{
 452	struct se_device *dev = cmd->se_dev;
 453	u64 segment_size, segment_mult, sectors, lba;
 454
 455	/* Only need to check for cdb actually containing LBAs */
 456	if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB))
 457		return 0;
 458
 459	spin_lock(&dev->t10_alua.lba_map_lock);
 460	segment_size = dev->t10_alua.lba_map_segment_size;
 461	segment_mult = dev->t10_alua.lba_map_segment_multiplier;
 462	sectors = cmd->data_length / dev->dev_attrib.block_size;
 463
 464	lba = cmd->t_task_lba;
 465	while (lba < cmd->t_task_lba + sectors) {
 466		struct t10_alua_lba_map *cur_map = NULL, *map;
 467		struct t10_alua_lba_map_member *map_mem;
 468
 469		list_for_each_entry(map, &dev->t10_alua.lba_map_list,
 470				    lba_map_list) {
 471			u64 start_lba, last_lba;
 472			u64 first_lba = map->lba_map_first_lba;
 473
 474			if (segment_mult) {
 475				u64 tmp = lba;
 476				start_lba = do_div(tmp, segment_size * segment_mult);
 477
 478				last_lba = first_lba + segment_size - 1;
 479				if (start_lba >= first_lba &&
 480				    start_lba <= last_lba) {
 481					lba += segment_size;
 482					cur_map = map;
 483					break;
 484				}
 485			} else {
 486				last_lba = map->lba_map_last_lba;
 487				if (lba >= first_lba && lba <= last_lba) {
 488					lba = last_lba + 1;
 489					cur_map = map;
 490					break;
 491				}
 492			}
 493		}
 494		if (!cur_map) {
 495			spin_unlock(&dev->t10_alua.lba_map_lock);
 496			return TCM_ALUA_TG_PT_UNAVAILABLE;
 497		}
 498		list_for_each_entry(map_mem, &cur_map->lba_map_mem_list,
 499				    lba_map_mem_list) {
 500			if (map_mem->lba_map_mem_alua_pg_id != tg_pt_gp_id)
 501				continue;
 502			switch(map_mem->lba_map_mem_alua_state) {
 503			case ALUA_ACCESS_STATE_STANDBY:
 504				spin_unlock(&dev->t10_alua.lba_map_lock);
 505				return TCM_ALUA_TG_PT_STANDBY;
 506			case ALUA_ACCESS_STATE_UNAVAILABLE:
 507				spin_unlock(&dev->t10_alua.lba_map_lock);
 508				return TCM_ALUA_TG_PT_UNAVAILABLE;
 509			default:
 510				break;
 511			}
 512		}
 513	}
 514	spin_unlock(&dev->t10_alua.lba_map_lock);
 515	return 0;
 516}
 517
 518static inline sense_reason_t core_alua_state_standby(
 519	struct se_cmd *cmd,
 520	unsigned char *cdb)
 521{
 522	/*
 523	 * Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
 524	 * spc4r17 section 5.9.2.4.4
 525	 */
 526	switch (cdb[0]) {
 527	case INQUIRY:
 528	case LOG_SELECT:
 529	case LOG_SENSE:
 530	case MODE_SELECT:
 531	case MODE_SENSE:
 532	case REPORT_LUNS:
 533	case RECEIVE_DIAGNOSTIC:
 534	case SEND_DIAGNOSTIC:
 535	case READ_CAPACITY:
 536		return 0;
 537	case SERVICE_ACTION_IN_16:
 538		switch (cdb[1] & 0x1f) {
 539		case SAI_READ_CAPACITY_16:
 540			return 0;
 541		default:
 542			return TCM_ALUA_TG_PT_STANDBY;
 543		}
 544	case MAINTENANCE_IN:
 545		switch (cdb[1] & 0x1f) {
 546		case MI_REPORT_TARGET_PGS:
 547			return 0;
 548		default:
 549			return TCM_ALUA_TG_PT_STANDBY;
 550		}
 551	case MAINTENANCE_OUT:
 552		switch (cdb[1]) {
 553		case MO_SET_TARGET_PGS:
 554			return 0;
 555		default:
 556			return TCM_ALUA_TG_PT_STANDBY;
 557		}
 558	case REQUEST_SENSE:
 559	case PERSISTENT_RESERVE_IN:
 560	case PERSISTENT_RESERVE_OUT:
 561	case READ_BUFFER:
 562	case WRITE_BUFFER:
 563		return 0;
 564	default:
 565		return TCM_ALUA_TG_PT_STANDBY;
 566	}
 567
 568	return 0;
 569}
 570
 571static inline sense_reason_t core_alua_state_unavailable(
 572	struct se_cmd *cmd,
 573	unsigned char *cdb)
 574{
 575	/*
 576	 * Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
 577	 * spc4r17 section 5.9.2.4.5
 578	 */
 579	switch (cdb[0]) {
 580	case INQUIRY:
 581	case REPORT_LUNS:
 582		return 0;
 583	case MAINTENANCE_IN:
 584		switch (cdb[1] & 0x1f) {
 585		case MI_REPORT_TARGET_PGS:
 586			return 0;
 587		default:
 588			return TCM_ALUA_TG_PT_UNAVAILABLE;
 589		}
 590	case MAINTENANCE_OUT:
 591		switch (cdb[1]) {
 592		case MO_SET_TARGET_PGS:
 593			return 0;
 594		default:
 595			return TCM_ALUA_TG_PT_UNAVAILABLE;
 596		}
 597	case REQUEST_SENSE:
 598	case READ_BUFFER:
 599	case WRITE_BUFFER:
 600		return 0;
 601	default:
 602		return TCM_ALUA_TG_PT_UNAVAILABLE;
 603	}
 604
 605	return 0;
 606}
 607
 608static inline sense_reason_t core_alua_state_transition(
 609	struct se_cmd *cmd,
 610	unsigned char *cdb)
 611{
 612	/*
 613	 * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITION as defined by
 614	 * spc4r17 section 5.9.2.5
 615	 */
 616	switch (cdb[0]) {
 617	case INQUIRY:
 618	case REPORT_LUNS:
 619		return 0;
 620	case MAINTENANCE_IN:
 621		switch (cdb[1] & 0x1f) {
 622		case MI_REPORT_TARGET_PGS:
 623			return 0;
 624		default:
 625			return TCM_ALUA_STATE_TRANSITION;
 626		}
 627	case REQUEST_SENSE:
 628	case READ_BUFFER:
 629	case WRITE_BUFFER:
 630		return 0;
 631	default:
 632		return TCM_ALUA_STATE_TRANSITION;
 633	}
 634
 635	return 0;
 636}
 637
 638/*
 639 * return 1: Is used to signal LUN not accessible, and check condition/not ready
 640 * return 0: Used to signal success
 641 * return -1: Used to signal failure, and invalid cdb field
 642 */
 643sense_reason_t
 644target_alua_state_check(struct se_cmd *cmd)
 645{
 646	struct se_device *dev = cmd->se_dev;
 647	unsigned char *cdb = cmd->t_task_cdb;
 648	struct se_lun *lun = cmd->se_lun;
 649	struct t10_alua_tg_pt_gp *tg_pt_gp;
 650	int out_alua_state, nonop_delay_msecs;
 651	u16 tg_pt_gp_id;
 652	sense_reason_t rc = TCM_NO_SENSE;
 653
 654	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
 655		return 0;
 656	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
 657		return 0;
 658
 659	/*
 660	 * First, check for a struct se_port specific secondary ALUA target port
 661	 * access state: OFFLINE
 662	 */
 663	if (atomic_read(&lun->lun_tg_pt_secondary_offline)) {
 664		pr_debug("ALUA: Got secondary offline status for local"
 665				" target port\n");
 666		return TCM_ALUA_OFFLINE;
 667	}
 668	rcu_read_lock();
 669	tg_pt_gp = rcu_dereference(lun->lun_tg_pt_gp);
 670	if (!tg_pt_gp) {
 671		rcu_read_unlock();
 672		return 0;
 673	}
 674
 675	out_alua_state = tg_pt_gp->tg_pt_gp_alua_access_state;
 676	nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
 677	tg_pt_gp_id = tg_pt_gp->tg_pt_gp_id;
 678	rcu_read_unlock();
 679	/*
 680	 * Process ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED in a separate conditional
 681	 * statement so the compiler knows explicitly to check this case first.
 682	 * For the Optimized ALUA access state case, we want to process the
 683	 * incoming fabric cmd ASAP..
 684	 */
 685	if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED)
 686		return 0;
 687
 688	switch (out_alua_state) {
 689	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 690		core_alua_state_nonoptimized(cmd, cdb, nonop_delay_msecs);
 691		break;
 692	case ALUA_ACCESS_STATE_STANDBY:
 693		rc = core_alua_state_standby(cmd, cdb);
 694		break;
 695	case ALUA_ACCESS_STATE_UNAVAILABLE:
 696		rc = core_alua_state_unavailable(cmd, cdb);
 697		break;
 698	case ALUA_ACCESS_STATE_TRANSITION:
 699		rc = core_alua_state_transition(cmd, cdb);
 700		break;
 701	case ALUA_ACCESS_STATE_LBA_DEPENDENT:
 702		rc = core_alua_state_lba_dependent(cmd, tg_pt_gp_id);
 703		break;
 704	/*
 705	 * OFFLINE is a secondary ALUA target port group access state, that is
 706	 * handled above with struct se_lun->lun_tg_pt_secondary_offline=1
 707	 */
 708	case ALUA_ACCESS_STATE_OFFLINE:
 709	default:
 710		pr_err("Unknown ALUA access state: 0x%02x\n",
 711				out_alua_state);
 712		rc = TCM_INVALID_CDB_FIELD;
 713	}
 714
 715	if (rc && rc != TCM_INVALID_CDB_FIELD) {
 716		pr_debug("[%s]: ALUA TG Port not available, "
 717			"SenseKey: NOT_READY, ASC/rc: 0x04/%d\n",
 718			cmd->se_tfo->fabric_name, rc);
 719	}
 720
 721	return rc;
 722}
 723
 724/*
 725 * Check implicit and explicit ALUA state change request.
 726 */
 727static sense_reason_t
 728core_alua_check_transition(int state, int valid, int *primary, int explicit)
 729{
 730	/*
 731	 * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
 732	 * defined as primary target port asymmetric access states.
 733	 */
 734	switch (state) {
 735	case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
 736		if (!(valid & ALUA_AO_SUP))
 737			goto not_supported;
 738		*primary = 1;
 739		break;
 740	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 741		if (!(valid & ALUA_AN_SUP))
 742			goto not_supported;
 743		*primary = 1;
 744		break;
 745	case ALUA_ACCESS_STATE_STANDBY:
 746		if (!(valid & ALUA_S_SUP))
 747			goto not_supported;
 748		*primary = 1;
 749		break;
 750	case ALUA_ACCESS_STATE_UNAVAILABLE:
 751		if (!(valid & ALUA_U_SUP))
 752			goto not_supported;
 753		*primary = 1;
 754		break;
 755	case ALUA_ACCESS_STATE_LBA_DEPENDENT:
 756		if (!(valid & ALUA_LBD_SUP))
 757			goto not_supported;
 758		*primary = 1;
 759		break;
 760	case ALUA_ACCESS_STATE_OFFLINE:
 761		/*
 762		 * OFFLINE state is defined as a secondary target port
 763		 * asymmetric access state.
 764		 */
 765		if (!(valid & ALUA_O_SUP))
 766			goto not_supported;
 767		*primary = 0;
 768		break;
 769	case ALUA_ACCESS_STATE_TRANSITION:
 770		if (!(valid & ALUA_T_SUP) || explicit)
 771			/*
 772			 * Transitioning is set internally and by tcmu daemon,
 773			 * and cannot be selected through a STPG.
 774			 */
 775			goto not_supported;
 776		*primary = 0;
 777		break;
 778	default:
 779		pr_err("Unknown ALUA access state: 0x%02x\n", state);
 780		return TCM_INVALID_PARAMETER_LIST;
 781	}
 782
 783	return 0;
 784
 785not_supported:
 786	pr_err("ALUA access state %s not supported",
 787	       core_alua_dump_state(state));
 788	return TCM_INVALID_PARAMETER_LIST;
 789}
 790
 791static char *core_alua_dump_state(int state)
 792{
 793	switch (state) {
 794	case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
 795		return "Active/Optimized";
 796	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
 797		return "Active/NonOptimized";
 798	case ALUA_ACCESS_STATE_LBA_DEPENDENT:
 799		return "LBA Dependent";
 800	case ALUA_ACCESS_STATE_STANDBY:
 801		return "Standby";
 802	case ALUA_ACCESS_STATE_UNAVAILABLE:
 803		return "Unavailable";
 804	case ALUA_ACCESS_STATE_OFFLINE:
 805		return "Offline";
 806	case ALUA_ACCESS_STATE_TRANSITION:
 807		return "Transitioning";
 808	default:
 809		return "Unknown";
 810	}
 811
 812	return NULL;
 813}
 814
 815char *core_alua_dump_status(int status)
 816{
 817	switch (status) {
 818	case ALUA_STATUS_NONE:
 819		return "None";
 820	case ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG:
 821		return "Altered by Explicit STPG";
 822	case ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA:
 823		return "Altered by Implicit ALUA";
 824	default:
 825		return "Unknown";
 826	}
 827
 828	return NULL;
 829}
 830
 831/*
 832 * Used by fabric modules to determine when we need to delay processing
 833 * for the Active/NonOptimized paths..
 834 */
 835int core_alua_check_nonop_delay(
 836	struct se_cmd *cmd)
 837{
 838	if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
 839		return 0;
 840	/*
 841	 * The ALUA Active/NonOptimized access state delay can be disabled
 842	 * in via configfs with a value of zero
 843	 */
 844	if (!cmd->alua_nonop_delay)
 845		return 0;
 846	/*
 847	 * struct se_cmd->alua_nonop_delay gets set by a target port group
 848	 * defined interval in core_alua_state_nonoptimized()
 849	 */
 850	msleep_interruptible(cmd->alua_nonop_delay);
 851	return 0;
 852}
 853EXPORT_SYMBOL(core_alua_check_nonop_delay);
 854
 855static int core_alua_write_tpg_metadata(
 856	const char *path,
 857	unsigned char *md_buf,
 858	u32 md_buf_len)
 859{
 860	struct file *file = filp_open(path, O_RDWR | O_CREAT | O_TRUNC, 0600);
 861	loff_t pos = 0;
 862	int ret;
 863
 864	if (IS_ERR(file)) {
 865		pr_err("filp_open(%s) for ALUA metadata failed\n", path);
 866		return -ENODEV;
 867	}
 868	ret = kernel_write(file, md_buf, md_buf_len, &pos);
 869	if (ret < 0)
 870		pr_err("Error writing ALUA metadata file: %s\n", path);
 871	fput(file);
 872	return (ret < 0) ? -EIO : 0;
 873}
 874
 875static int core_alua_update_tpg_primary_metadata(
 876	struct t10_alua_tg_pt_gp *tg_pt_gp)
 877{
 878	unsigned char *md_buf;
 879	struct t10_wwn *wwn = &tg_pt_gp->tg_pt_gp_dev->t10_wwn;
 880	char *path;
 881	int len, rc;
 882
 883	lockdep_assert_held(&tg_pt_gp->tg_pt_gp_transition_mutex);
 884
 885	md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
 886	if (!md_buf) {
 887		pr_err("Unable to allocate buf for ALUA metadata\n");
 888		return -ENOMEM;
 889	}
 890
 891	len = snprintf(md_buf, ALUA_MD_BUF_LEN,
 892			"tg_pt_gp_id=%hu\n"
 893			"alua_access_state=0x%02x\n"
 894			"alua_access_status=0x%02x\n",
 895			tg_pt_gp->tg_pt_gp_id,
 896			tg_pt_gp->tg_pt_gp_alua_access_state,
 897			tg_pt_gp->tg_pt_gp_alua_access_status);
 898
 899	rc = -ENOMEM;
 900	path = kasprintf(GFP_KERNEL, "%s/alua/tpgs_%s/%s", db_root,
 901			&wwn->unit_serial[0],
 902			config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
 903	if (path) {
 904		rc = core_alua_write_tpg_metadata(path, md_buf, len);
 905		kfree(path);
 906	}
 907	kfree(md_buf);
 908	return rc;
 909}
 910
 911static void core_alua_queue_state_change_ua(struct t10_alua_tg_pt_gp *tg_pt_gp)
 912{
 913	struct se_dev_entry *se_deve;
 914	struct se_lun *lun;
 915	struct se_lun_acl *lacl;
 916
 917	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 918	list_for_each_entry(lun, &tg_pt_gp->tg_pt_gp_lun_list,
 919				lun_tg_pt_gp_link) {
 920		/*
 921		 * After an implicit target port asymmetric access state
 922		 * change, a device server shall establish a unit attention
 923		 * condition for the initiator port associated with every I_T
 924		 * nexus with the additional sense code set to ASYMMETRIC
 925		 * ACCESS STATE CHANGED.
 926		 *
 927		 * After an explicit target port asymmetric access state
 928		 * change, a device server shall establish a unit attention
 929		 * condition with the additional sense code set to ASYMMETRIC
 930		 * ACCESS STATE CHANGED for the initiator port associated with
 931		 * every I_T nexus other than the I_T nexus on which the SET
 932		 * TARGET PORT GROUPS command
 933		 */
 934		if (!percpu_ref_tryget_live(&lun->lun_ref))
 935			continue;
 936		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 937
 938		spin_lock(&lun->lun_deve_lock);
 939		list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link) {
 940			lacl = se_deve->se_lun_acl;
 941
 942			/*
 943			 * spc4r37 p.242:
 944			 * After an explicit target port asymmetric access
 945			 * state change, a device server shall establish a
 946			 * unit attention condition with the additional sense
 947			 * code set to ASYMMETRIC ACCESS STATE CHANGED for
 948			 * the initiator port associated with every I_T nexus
 949			 * other than the I_T nexus on which the SET TARGET
 950			 * PORT GROUPS command was received.
 951			 */
 952			if ((tg_pt_gp->tg_pt_gp_alua_access_status ==
 953			     ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
 954			   (tg_pt_gp->tg_pt_gp_alua_lun != NULL) &&
 955			    (tg_pt_gp->tg_pt_gp_alua_lun == lun))
 956				continue;
 957
 958			/*
 959			 * se_deve->se_lun_acl pointer may be NULL for a
 960			 * entry created without explicit Node+MappedLUN ACLs
 961			 */
 962			if (lacl && (tg_pt_gp->tg_pt_gp_alua_nacl != NULL) &&
 963			    (tg_pt_gp->tg_pt_gp_alua_nacl == lacl->se_lun_nacl))
 964				continue;
 965
 966			core_scsi3_ua_allocate(se_deve, 0x2A,
 967				ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
 968		}
 969		spin_unlock(&lun->lun_deve_lock);
 970
 971		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 972		percpu_ref_put(&lun->lun_ref);
 973	}
 974	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 975}
 976
 977static int core_alua_do_transition_tg_pt(
 978	struct t10_alua_tg_pt_gp *tg_pt_gp,
 979	int new_state,
 980	int explicit)
 981{
 982	int prev_state;
 983
 984	mutex_lock(&tg_pt_gp->tg_pt_gp_transition_mutex);
 985	/* Nothing to be done here */
 986	if (tg_pt_gp->tg_pt_gp_alua_access_state == new_state) {
 987		mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
 988		return 0;
 989	}
 990
 991	if (explicit && new_state == ALUA_ACCESS_STATE_TRANSITION) {
 992		mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
 993		return -EAGAIN;
 994	}
 995
 996	/*
 997	 * Save the old primary ALUA access state, and set the current state
 998	 * to ALUA_ACCESS_STATE_TRANSITION.
 999	 */
1000	prev_state = tg_pt_gp->tg_pt_gp_alua_access_state;
1001	tg_pt_gp->tg_pt_gp_alua_access_state = ALUA_ACCESS_STATE_TRANSITION;
1002	tg_pt_gp->tg_pt_gp_alua_access_status = (explicit) ?
1003				ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
1004				ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
1005
1006	core_alua_queue_state_change_ua(tg_pt_gp);
1007
1008	if (new_state == ALUA_ACCESS_STATE_TRANSITION) {
1009		mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1010		return 0;
1011	}
1012
1013	/*
1014	 * Check for the optional ALUA primary state transition delay
1015	 */
1016	if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
1017		msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
1018
1019	/*
1020	 * Set the current primary ALUA access state to the requested new state
1021	 */
1022	tg_pt_gp->tg_pt_gp_alua_access_state = new_state;
1023
1024	/*
1025	 * Update the ALUA metadata buf that has been allocated in
1026	 * core_alua_do_port_transition(), this metadata will be written
1027	 * to struct file.
1028	 *
1029	 * Note that there is the case where we do not want to update the
1030	 * metadata when the saved metadata is being parsed in userspace
1031	 * when setting the existing port access state and access status.
1032	 *
1033	 * Also note that the failure to write out the ALUA metadata to
1034	 * struct file does NOT affect the actual ALUA transition.
1035	 */
1036	if (tg_pt_gp->tg_pt_gp_write_metadata) {
1037		core_alua_update_tpg_primary_metadata(tg_pt_gp);
1038	}
1039
1040	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1041		" from primary access state %s to %s\n", (explicit) ? "explicit" :
1042		"implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1043		tg_pt_gp->tg_pt_gp_id,
1044		core_alua_dump_state(prev_state),
1045		core_alua_dump_state(new_state));
1046
1047	core_alua_queue_state_change_ua(tg_pt_gp);
1048
1049	mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1050	return 0;
1051}
1052
1053int core_alua_do_port_transition(
1054	struct t10_alua_tg_pt_gp *l_tg_pt_gp,
1055	struct se_device *l_dev,
1056	struct se_lun *l_lun,
1057	struct se_node_acl *l_nacl,
1058	int new_state,
1059	int explicit)
1060{
1061	struct se_device *dev;
1062	struct t10_alua_lu_gp *lu_gp;
1063	struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
1064	struct t10_alua_tg_pt_gp *tg_pt_gp;
1065	int primary, valid_states, rc = 0;
1066
1067	if (l_dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
1068		return -ENODEV;
1069
1070	valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
1071	if (core_alua_check_transition(new_state, valid_states, &primary,
1072				       explicit) != 0)
1073		return -EINVAL;
1074
1075	local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
1076	spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
1077	lu_gp = local_lu_gp_mem->lu_gp;
1078	atomic_inc(&lu_gp->lu_gp_ref_cnt);
1079	spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
1080	/*
1081	 * For storage objects that are members of the 'default_lu_gp',
1082	 * we only do transition on the passed *l_tp_pt_gp, and not
1083	 * on all of the matching target port groups IDs in default_lu_gp.
1084	 */
1085	if (!lu_gp->lu_gp_id) {
1086		/*
1087		 * core_alua_do_transition_tg_pt() will always return
1088		 * success.
1089		 */
1090		l_tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
1091		l_tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
1092		rc = core_alua_do_transition_tg_pt(l_tg_pt_gp,
1093						   new_state, explicit);
1094		atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
1095		return rc;
1096	}
1097	/*
1098	 * For all other LU groups aside from 'default_lu_gp', walk all of
1099	 * the associated storage objects looking for a matching target port
1100	 * group ID from the local target port group.
1101	 */
1102	spin_lock(&lu_gp->lu_gp_lock);
1103	list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
1104				lu_gp_mem_list) {
1105
1106		dev = lu_gp_mem->lu_gp_mem_dev;
1107		atomic_inc_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
1108		spin_unlock(&lu_gp->lu_gp_lock);
1109
1110		spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1111		list_for_each_entry(tg_pt_gp,
1112				&dev->t10_alua.tg_pt_gps_list,
1113				tg_pt_gp_list) {
1114
1115			if (!tg_pt_gp->tg_pt_gp_valid_id)
1116				continue;
1117			/*
1118			 * If the target behavior port asymmetric access state
1119			 * is changed for any target port group accessible via
1120			 * a logical unit within a LU group, the target port
1121			 * behavior group asymmetric access states for the same
1122			 * target port group accessible via other logical units
1123			 * in that LU group will also change.
1124			 */
1125			if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
1126				continue;
1127
1128			if (l_tg_pt_gp == tg_pt_gp) {
1129				tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
1130				tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
1131			} else {
1132				tg_pt_gp->tg_pt_gp_alua_lun = NULL;
1133				tg_pt_gp->tg_pt_gp_alua_nacl = NULL;
1134			}
1135			atomic_inc_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
1136			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1137			/*
1138			 * core_alua_do_transition_tg_pt() will always return
1139			 * success.
1140			 */
1141			rc = core_alua_do_transition_tg_pt(tg_pt_gp,
1142					new_state, explicit);
1143
1144			spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1145			atomic_dec_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
1146			if (rc)
1147				break;
1148		}
1149		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1150
1151		spin_lock(&lu_gp->lu_gp_lock);
1152		atomic_dec_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
1153	}
1154	spin_unlock(&lu_gp->lu_gp_lock);
1155
1156	if (!rc) {
1157		pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
1158			 " Group IDs: %hu %s transition to primary state: %s\n",
1159			 config_item_name(&lu_gp->lu_gp_group.cg_item),
1160			 l_tg_pt_gp->tg_pt_gp_id,
1161			 (explicit) ? "explicit" : "implicit",
1162			 core_alua_dump_state(new_state));
1163	}
1164
1165	atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
1166	return rc;
1167}
1168
1169static int core_alua_update_tpg_secondary_metadata(struct se_lun *lun)
1170{
1171	struct se_portal_group *se_tpg = lun->lun_tpg;
1172	unsigned char *md_buf;
1173	char *path;
1174	int len, rc;
1175
1176	mutex_lock(&lun->lun_tg_pt_md_mutex);
1177
1178	md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
1179	if (!md_buf) {
1180		pr_err("Unable to allocate buf for ALUA metadata\n");
1181		rc = -ENOMEM;
1182		goto out_unlock;
1183	}
1184
1185	len = snprintf(md_buf, ALUA_MD_BUF_LEN, "alua_tg_pt_offline=%d\n"
1186			"alua_tg_pt_status=0x%02x\n",
1187			atomic_read(&lun->lun_tg_pt_secondary_offline),
1188			lun->lun_tg_pt_secondary_stat);
1189
1190	if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL) {
1191		path = kasprintf(GFP_KERNEL, "%s/alua/%s/%s+%hu/lun_%llu",
1192				db_root, se_tpg->se_tpg_tfo->fabric_name,
1193				se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg),
1194				se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg),
1195				lun->unpacked_lun);
1196	} else {
1197		path = kasprintf(GFP_KERNEL, "%s/alua/%s/%s/lun_%llu",
1198				db_root, se_tpg->se_tpg_tfo->fabric_name,
1199				se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg),
1200				lun->unpacked_lun);
1201	}
1202	if (!path) {
1203		rc = -ENOMEM;
1204		goto out_free;
1205	}
1206
1207	rc = core_alua_write_tpg_metadata(path, md_buf, len);
1208	kfree(path);
1209out_free:
1210	kfree(md_buf);
1211out_unlock:
1212	mutex_unlock(&lun->lun_tg_pt_md_mutex);
1213	return rc;
1214}
1215
1216static int core_alua_set_tg_pt_secondary_state(
1217	struct se_lun *lun,
1218	int explicit,
1219	int offline)
1220{
1221	struct t10_alua_tg_pt_gp *tg_pt_gp;
1222	int trans_delay_msecs;
1223
1224	rcu_read_lock();
1225	tg_pt_gp = rcu_dereference(lun->lun_tg_pt_gp);
1226	if (!tg_pt_gp) {
1227		rcu_read_unlock();
1228		pr_err("Unable to complete secondary state"
1229				" transition\n");
1230		return -EINVAL;
1231	}
1232	trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
1233	/*
1234	 * Set the secondary ALUA target port access state to OFFLINE
1235	 * or release the previously secondary state for struct se_lun
1236	 */
1237	if (offline)
1238		atomic_set(&lun->lun_tg_pt_secondary_offline, 1);
1239	else
1240		atomic_set(&lun->lun_tg_pt_secondary_offline, 0);
1241
1242	lun->lun_tg_pt_secondary_stat = (explicit) ?
1243			ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
1244			ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
1245
1246	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1247		" to secondary access state: %s\n", (explicit) ? "explicit" :
1248		"implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1249		tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
1250
1251	rcu_read_unlock();
1252	/*
1253	 * Do the optional transition delay after we set the secondary
1254	 * ALUA access state.
1255	 */
1256	if (trans_delay_msecs != 0)
1257		msleep_interruptible(trans_delay_msecs);
1258	/*
1259	 * See if we need to update the ALUA fabric port metadata for
1260	 * secondary state and status
1261	 */
1262	if (lun->lun_tg_pt_secondary_write_md)
1263		core_alua_update_tpg_secondary_metadata(lun);
1264
1265	return 0;
1266}
1267
1268struct t10_alua_lba_map *
1269core_alua_allocate_lba_map(struct list_head *list,
1270			   u64 first_lba, u64 last_lba)
1271{
1272	struct t10_alua_lba_map *lba_map;
1273
1274	lba_map = kmem_cache_zalloc(t10_alua_lba_map_cache, GFP_KERNEL);
1275	if (!lba_map) {
1276		pr_err("Unable to allocate struct t10_alua_lba_map\n");
1277		return ERR_PTR(-ENOMEM);
1278	}
1279	INIT_LIST_HEAD(&lba_map->lba_map_mem_list);
1280	lba_map->lba_map_first_lba = first_lba;
1281	lba_map->lba_map_last_lba = last_lba;
1282
1283	list_add_tail(&lba_map->lba_map_list, list);
1284	return lba_map;
1285}
1286
1287int
1288core_alua_allocate_lba_map_mem(struct t10_alua_lba_map *lba_map,
1289			       int pg_id, int state)
1290{
1291	struct t10_alua_lba_map_member *lba_map_mem;
1292
1293	list_for_each_entry(lba_map_mem, &lba_map->lba_map_mem_list,
1294			    lba_map_mem_list) {
1295		if (lba_map_mem->lba_map_mem_alua_pg_id == pg_id) {
1296			pr_err("Duplicate pg_id %d in lba_map\n", pg_id);
1297			return -EINVAL;
1298		}
1299	}
1300
1301	lba_map_mem = kmem_cache_zalloc(t10_alua_lba_map_mem_cache, GFP_KERNEL);
1302	if (!lba_map_mem) {
1303		pr_err("Unable to allocate struct t10_alua_lba_map_mem\n");
1304		return -ENOMEM;
1305	}
1306	lba_map_mem->lba_map_mem_alua_state = state;
1307	lba_map_mem->lba_map_mem_alua_pg_id = pg_id;
1308
1309	list_add_tail(&lba_map_mem->lba_map_mem_list,
1310		      &lba_map->lba_map_mem_list);
1311	return 0;
1312}
1313
1314void
1315core_alua_free_lba_map(struct list_head *lba_list)
1316{
1317	struct t10_alua_lba_map *lba_map, *lba_map_tmp;
1318	struct t10_alua_lba_map_member *lba_map_mem, *lba_map_mem_tmp;
1319
1320	list_for_each_entry_safe(lba_map, lba_map_tmp, lba_list,
1321				 lba_map_list) {
1322		list_for_each_entry_safe(lba_map_mem, lba_map_mem_tmp,
1323					 &lba_map->lba_map_mem_list,
1324					 lba_map_mem_list) {
1325			list_del(&lba_map_mem->lba_map_mem_list);
1326			kmem_cache_free(t10_alua_lba_map_mem_cache,
1327					lba_map_mem);
1328		}
1329		list_del(&lba_map->lba_map_list);
1330		kmem_cache_free(t10_alua_lba_map_cache, lba_map);
1331	}
1332}
1333
1334void
1335core_alua_set_lba_map(struct se_device *dev, struct list_head *lba_map_list,
1336		      int segment_size, int segment_mult)
1337{
1338	struct list_head old_lba_map_list;
1339	struct t10_alua_tg_pt_gp *tg_pt_gp;
1340	int activate = 0, supported;
1341
1342	INIT_LIST_HEAD(&old_lba_map_list);
1343	spin_lock(&dev->t10_alua.lba_map_lock);
1344	dev->t10_alua.lba_map_segment_size = segment_size;
1345	dev->t10_alua.lba_map_segment_multiplier = segment_mult;
1346	list_splice_init(&dev->t10_alua.lba_map_list, &old_lba_map_list);
1347	if (lba_map_list) {
1348		list_splice_init(lba_map_list, &dev->t10_alua.lba_map_list);
1349		activate = 1;
1350	}
1351	spin_unlock(&dev->t10_alua.lba_map_lock);
1352	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1353	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
1354			    tg_pt_gp_list) {
1355
1356		if (!tg_pt_gp->tg_pt_gp_valid_id)
1357			continue;
1358		supported = tg_pt_gp->tg_pt_gp_alua_supported_states;
1359		if (activate)
1360			supported |= ALUA_LBD_SUP;
1361		else
1362			supported &= ~ALUA_LBD_SUP;
1363		tg_pt_gp->tg_pt_gp_alua_supported_states = supported;
1364	}
1365	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1366	core_alua_free_lba_map(&old_lba_map_list);
1367}
1368
1369struct t10_alua_lu_gp *
1370core_alua_allocate_lu_gp(const char *name, int def_group)
1371{
1372	struct t10_alua_lu_gp *lu_gp;
1373
1374	lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
1375	if (!lu_gp) {
1376		pr_err("Unable to allocate struct t10_alua_lu_gp\n");
1377		return ERR_PTR(-ENOMEM);
1378	}
1379	INIT_LIST_HEAD(&lu_gp->lu_gp_node);
1380	INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
1381	spin_lock_init(&lu_gp->lu_gp_lock);
1382	atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
1383
1384	if (def_group) {
1385		lu_gp->lu_gp_id = alua_lu_gps_counter++;
1386		lu_gp->lu_gp_valid_id = 1;
1387		alua_lu_gps_count++;
1388	}
1389
1390	return lu_gp;
1391}
1392
1393int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
1394{
1395	struct t10_alua_lu_gp *lu_gp_tmp;
1396	u16 lu_gp_id_tmp;
1397	/*
1398	 * The lu_gp->lu_gp_id may only be set once..
1399	 */
1400	if (lu_gp->lu_gp_valid_id) {
1401		pr_warn("ALUA LU Group already has a valid ID,"
1402			" ignoring request\n");
1403		return -EINVAL;
1404	}
1405
1406	spin_lock(&lu_gps_lock);
1407	if (alua_lu_gps_count == 0x0000ffff) {
1408		pr_err("Maximum ALUA alua_lu_gps_count:"
1409				" 0x0000ffff reached\n");
1410		spin_unlock(&lu_gps_lock);
1411		kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1412		return -ENOSPC;
1413	}
1414again:
1415	lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
1416				alua_lu_gps_counter++;
1417
1418	list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
1419		if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
1420			if (!lu_gp_id)
1421				goto again;
1422
1423			pr_warn("ALUA Logical Unit Group ID: %hu"
1424				" already exists, ignoring request\n",
1425				lu_gp_id);
1426			spin_unlock(&lu_gps_lock);
1427			return -EINVAL;
1428		}
1429	}
1430
1431	lu_gp->lu_gp_id = lu_gp_id_tmp;
1432	lu_gp->lu_gp_valid_id = 1;
1433	list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
1434	alua_lu_gps_count++;
1435	spin_unlock(&lu_gps_lock);
1436
1437	return 0;
1438}
1439
1440static struct t10_alua_lu_gp_member *
1441core_alua_allocate_lu_gp_mem(struct se_device *dev)
1442{
1443	struct t10_alua_lu_gp_member *lu_gp_mem;
1444
1445	lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
1446	if (!lu_gp_mem) {
1447		pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
1448		return ERR_PTR(-ENOMEM);
1449	}
1450	INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
1451	spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
1452	atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
1453
1454	lu_gp_mem->lu_gp_mem_dev = dev;
1455	dev->dev_alua_lu_gp_mem = lu_gp_mem;
1456
1457	return lu_gp_mem;
1458}
1459
1460void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
1461{
1462	struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
1463	/*
1464	 * Once we have reached this point, config_item_put() has
1465	 * already been called from target_core_alua_drop_lu_gp().
1466	 *
1467	 * Here, we remove the *lu_gp from the global list so that
1468	 * no associations can be made while we are releasing
1469	 * struct t10_alua_lu_gp.
1470	 */
1471	spin_lock(&lu_gps_lock);
1472	list_del(&lu_gp->lu_gp_node);
1473	alua_lu_gps_count--;
1474	spin_unlock(&lu_gps_lock);
1475	/*
1476	 * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1477	 * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1478	 * released with core_alua_put_lu_gp_from_name()
1479	 */
1480	while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1481		cpu_relax();
1482	/*
1483	 * Release reference to struct t10_alua_lu_gp * from all associated
1484	 * struct se_device.
1485	 */
1486	spin_lock(&lu_gp->lu_gp_lock);
1487	list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1488				&lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1489		if (lu_gp_mem->lu_gp_assoc) {
1490			list_del(&lu_gp_mem->lu_gp_mem_list);
1491			lu_gp->lu_gp_members--;
1492			lu_gp_mem->lu_gp_assoc = 0;
1493		}
1494		spin_unlock(&lu_gp->lu_gp_lock);
1495		/*
1496		 *
1497		 * lu_gp_mem is associated with a single
1498		 * struct se_device->dev_alua_lu_gp_mem, and is released when
1499		 * struct se_device is released via core_alua_free_lu_gp_mem().
1500		 *
1501		 * If the passed lu_gp does NOT match the default_lu_gp, assume
1502		 * we want to re-associate a given lu_gp_mem with default_lu_gp.
1503		 */
1504		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1505		if (lu_gp != default_lu_gp)
1506			__core_alua_attach_lu_gp_mem(lu_gp_mem,
1507					default_lu_gp);
1508		else
1509			lu_gp_mem->lu_gp = NULL;
1510		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1511
1512		spin_lock(&lu_gp->lu_gp_lock);
1513	}
1514	spin_unlock(&lu_gp->lu_gp_lock);
1515
1516	kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1517}
1518
1519void core_alua_free_lu_gp_mem(struct se_device *dev)
1520{
1521	struct t10_alua_lu_gp *lu_gp;
1522	struct t10_alua_lu_gp_member *lu_gp_mem;
1523
1524	lu_gp_mem = dev->dev_alua_lu_gp_mem;
1525	if (!lu_gp_mem)
1526		return;
1527
1528	while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1529		cpu_relax();
1530
1531	spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1532	lu_gp = lu_gp_mem->lu_gp;
1533	if (lu_gp) {
1534		spin_lock(&lu_gp->lu_gp_lock);
1535		if (lu_gp_mem->lu_gp_assoc) {
1536			list_del(&lu_gp_mem->lu_gp_mem_list);
1537			lu_gp->lu_gp_members--;
1538			lu_gp_mem->lu_gp_assoc = 0;
1539		}
1540		spin_unlock(&lu_gp->lu_gp_lock);
1541		lu_gp_mem->lu_gp = NULL;
1542	}
1543	spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1544
1545	kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1546}
1547
1548struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1549{
1550	struct t10_alua_lu_gp *lu_gp;
1551	struct config_item *ci;
1552
1553	spin_lock(&lu_gps_lock);
1554	list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1555		if (!lu_gp->lu_gp_valid_id)
1556			continue;
1557		ci = &lu_gp->lu_gp_group.cg_item;
1558		if (!strcmp(config_item_name(ci), name)) {
1559			atomic_inc(&lu_gp->lu_gp_ref_cnt);
1560			spin_unlock(&lu_gps_lock);
1561			return lu_gp;
1562		}
1563	}
1564	spin_unlock(&lu_gps_lock);
1565
1566	return NULL;
1567}
1568
1569void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1570{
1571	spin_lock(&lu_gps_lock);
1572	atomic_dec(&lu_gp->lu_gp_ref_cnt);
1573	spin_unlock(&lu_gps_lock);
1574}
1575
1576/*
1577 * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1578 */
1579void __core_alua_attach_lu_gp_mem(
1580	struct t10_alua_lu_gp_member *lu_gp_mem,
1581	struct t10_alua_lu_gp *lu_gp)
1582{
1583	spin_lock(&lu_gp->lu_gp_lock);
1584	lu_gp_mem->lu_gp = lu_gp;
1585	lu_gp_mem->lu_gp_assoc = 1;
1586	list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1587	lu_gp->lu_gp_members++;
1588	spin_unlock(&lu_gp->lu_gp_lock);
1589}
1590
1591/*
1592 * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1593 */
1594void __core_alua_drop_lu_gp_mem(
1595	struct t10_alua_lu_gp_member *lu_gp_mem,
1596	struct t10_alua_lu_gp *lu_gp)
1597{
1598	spin_lock(&lu_gp->lu_gp_lock);
1599	list_del(&lu_gp_mem->lu_gp_mem_list);
1600	lu_gp_mem->lu_gp = NULL;
1601	lu_gp_mem->lu_gp_assoc = 0;
1602	lu_gp->lu_gp_members--;
1603	spin_unlock(&lu_gp->lu_gp_lock);
1604}
1605
1606struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(struct se_device *dev,
1607		const char *name, int def_group)
1608{
1609	struct t10_alua_tg_pt_gp *tg_pt_gp;
1610
1611	tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1612	if (!tg_pt_gp) {
1613		pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1614		return NULL;
1615	}
1616	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1617	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_lun_list);
1618	mutex_init(&tg_pt_gp->tg_pt_gp_transition_mutex);
1619	spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1620	atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1621	tg_pt_gp->tg_pt_gp_dev = dev;
1622	tg_pt_gp->tg_pt_gp_alua_access_state =
1623			ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED;
1624	/*
1625	 * Enable both explicit and implicit ALUA support by default
1626	 */
1627	tg_pt_gp->tg_pt_gp_alua_access_type =
1628			TPGS_EXPLICIT_ALUA | TPGS_IMPLICIT_ALUA;
1629	/*
1630	 * Set the default Active/NonOptimized Delay in milliseconds
1631	 */
1632	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1633	tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1634	tg_pt_gp->tg_pt_gp_implicit_trans_secs = ALUA_DEFAULT_IMPLICIT_TRANS_SECS;
1635
1636	/*
1637	 * Enable all supported states
1638	 */
1639	tg_pt_gp->tg_pt_gp_alua_supported_states =
1640	    ALUA_T_SUP | ALUA_O_SUP |
1641	    ALUA_U_SUP | ALUA_S_SUP | ALUA_AN_SUP | ALUA_AO_SUP;
1642
1643	if (def_group) {
1644		spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1645		tg_pt_gp->tg_pt_gp_id =
1646				dev->t10_alua.alua_tg_pt_gps_counter++;
1647		tg_pt_gp->tg_pt_gp_valid_id = 1;
1648		dev->t10_alua.alua_tg_pt_gps_count++;
1649		list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1650			      &dev->t10_alua.tg_pt_gps_list);
1651		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1652	}
1653
1654	return tg_pt_gp;
1655}
1656
1657int core_alua_set_tg_pt_gp_id(
1658	struct t10_alua_tg_pt_gp *tg_pt_gp,
1659	u16 tg_pt_gp_id)
1660{
1661	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1662	struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1663	u16 tg_pt_gp_id_tmp;
1664
1665	/*
1666	 * The tg_pt_gp->tg_pt_gp_id may only be set once..
1667	 */
1668	if (tg_pt_gp->tg_pt_gp_valid_id) {
1669		pr_warn("ALUA TG PT Group already has a valid ID,"
1670			" ignoring request\n");
1671		return -EINVAL;
1672	}
1673
1674	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1675	if (dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1676		pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1677			" 0x0000ffff reached\n");
1678		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1679		return -ENOSPC;
1680	}
1681again:
1682	tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1683			dev->t10_alua.alua_tg_pt_gps_counter++;
1684
1685	list_for_each_entry(tg_pt_gp_tmp, &dev->t10_alua.tg_pt_gps_list,
1686			tg_pt_gp_list) {
1687		if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1688			if (!tg_pt_gp_id)
1689				goto again;
1690
1691			pr_err("ALUA Target Port Group ID: %hu already"
1692				" exists, ignoring request\n", tg_pt_gp_id);
1693			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1694			return -EINVAL;
1695		}
1696	}
1697
1698	tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1699	tg_pt_gp->tg_pt_gp_valid_id = 1;
1700	list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1701			&dev->t10_alua.tg_pt_gps_list);
1702	dev->t10_alua.alua_tg_pt_gps_count++;
1703	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1704
1705	return 0;
1706}
1707
1708void core_alua_free_tg_pt_gp(
1709	struct t10_alua_tg_pt_gp *tg_pt_gp)
1710{
1711	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1712	struct se_lun *lun, *next;
1713
1714	/*
1715	 * Once we have reached this point, config_item_put() has already
1716	 * been called from target_core_alua_drop_tg_pt_gp().
1717	 *
1718	 * Here we remove *tg_pt_gp from the global list so that
1719	 * no associations *OR* explicit ALUA via SET_TARGET_PORT_GROUPS
1720	 * can be made while we are releasing struct t10_alua_tg_pt_gp.
1721	 */
1722	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1723	if (tg_pt_gp->tg_pt_gp_valid_id) {
1724		list_del(&tg_pt_gp->tg_pt_gp_list);
1725		dev->t10_alua.alua_tg_pt_gps_count--;
1726	}
1727	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1728
1729	/*
1730	 * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1731	 * core_alua_get_tg_pt_gp_by_name() in
1732	 * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1733	 * to be released with core_alua_put_tg_pt_gp_from_name().
1734	 */
1735	while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1736		cpu_relax();
1737
1738	/*
1739	 * Release reference to struct t10_alua_tg_pt_gp from all associated
1740	 * struct se_port.
1741	 */
1742	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1743	list_for_each_entry_safe(lun, next,
1744			&tg_pt_gp->tg_pt_gp_lun_list, lun_tg_pt_gp_link) {
1745		list_del_init(&lun->lun_tg_pt_gp_link);
1746		tg_pt_gp->tg_pt_gp_members--;
1747
1748		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1749		/*
1750		 * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1751		 * assume we want to re-associate a given tg_pt_gp_mem with
1752		 * default_tg_pt_gp.
1753		 */
1754		spin_lock(&lun->lun_tg_pt_gp_lock);
1755		if (tg_pt_gp != dev->t10_alua.default_tg_pt_gp) {
1756			__target_attach_tg_pt_gp(lun,
1757					dev->t10_alua.default_tg_pt_gp);
1758		} else
1759			rcu_assign_pointer(lun->lun_tg_pt_gp, NULL);
1760		spin_unlock(&lun->lun_tg_pt_gp_lock);
1761
1762		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1763	}
1764	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1765
1766	synchronize_rcu();
1767	kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1768}
1769
1770static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1771		struct se_device *dev, const char *name)
1772{
1773	struct t10_alua_tg_pt_gp *tg_pt_gp;
1774	struct config_item *ci;
1775
1776	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1777	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
1778			tg_pt_gp_list) {
1779		if (!tg_pt_gp->tg_pt_gp_valid_id)
1780			continue;
1781		ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1782		if (!strcmp(config_item_name(ci), name)) {
1783			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1784			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1785			return tg_pt_gp;
1786		}
1787	}
1788	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1789
1790	return NULL;
1791}
1792
1793static void core_alua_put_tg_pt_gp_from_name(
1794	struct t10_alua_tg_pt_gp *tg_pt_gp)
1795{
1796	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1797
1798	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1799	atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1800	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1801}
1802
1803static void __target_attach_tg_pt_gp(struct se_lun *lun,
1804		struct t10_alua_tg_pt_gp *tg_pt_gp)
1805{
1806	struct se_dev_entry *se_deve;
1807
1808	assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1809
1810	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1811	rcu_assign_pointer(lun->lun_tg_pt_gp, tg_pt_gp);
1812	list_add_tail(&lun->lun_tg_pt_gp_link, &tg_pt_gp->tg_pt_gp_lun_list);
1813	tg_pt_gp->tg_pt_gp_members++;
1814	spin_lock(&lun->lun_deve_lock);
1815	list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link)
1816		core_scsi3_ua_allocate(se_deve, 0x3f,
1817				       ASCQ_3FH_INQUIRY_DATA_HAS_CHANGED);
1818	spin_unlock(&lun->lun_deve_lock);
1819	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1820}
1821
1822void target_attach_tg_pt_gp(struct se_lun *lun,
1823		struct t10_alua_tg_pt_gp *tg_pt_gp)
1824{
1825	spin_lock(&lun->lun_tg_pt_gp_lock);
1826	__target_attach_tg_pt_gp(lun, tg_pt_gp);
1827	spin_unlock(&lun->lun_tg_pt_gp_lock);
1828	synchronize_rcu();
1829}
1830
1831static void __target_detach_tg_pt_gp(struct se_lun *lun,
1832		struct t10_alua_tg_pt_gp *tg_pt_gp)
1833{
1834	assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1835
1836	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1837	list_del_init(&lun->lun_tg_pt_gp_link);
1838	tg_pt_gp->tg_pt_gp_members--;
1839	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1840}
1841
1842void target_detach_tg_pt_gp(struct se_lun *lun)
1843{
1844	struct t10_alua_tg_pt_gp *tg_pt_gp;
1845
1846	spin_lock(&lun->lun_tg_pt_gp_lock);
1847	tg_pt_gp = rcu_dereference_check(lun->lun_tg_pt_gp,
1848				lockdep_is_held(&lun->lun_tg_pt_gp_lock));
1849	if (tg_pt_gp) {
1850		__target_detach_tg_pt_gp(lun, tg_pt_gp);
1851		rcu_assign_pointer(lun->lun_tg_pt_gp, NULL);
1852	}
1853	spin_unlock(&lun->lun_tg_pt_gp_lock);
1854	synchronize_rcu();
1855}
1856
1857static void target_swap_tg_pt_gp(struct se_lun *lun,
1858				 struct t10_alua_tg_pt_gp *old_tg_pt_gp,
1859				 struct t10_alua_tg_pt_gp *new_tg_pt_gp)
1860{
1861	assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1862
1863	if (old_tg_pt_gp)
1864		__target_detach_tg_pt_gp(lun, old_tg_pt_gp);
1865	__target_attach_tg_pt_gp(lun, new_tg_pt_gp);
1866}
1867
1868ssize_t core_alua_show_tg_pt_gp_info(struct se_lun *lun, char *page)
1869{
1870	struct config_item *tg_pt_ci;
1871	struct t10_alua_tg_pt_gp *tg_pt_gp;
1872	ssize_t len = 0;
1873
1874	rcu_read_lock();
1875	tg_pt_gp = rcu_dereference(lun->lun_tg_pt_gp);
1876	if (tg_pt_gp) {
1877		tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1878		len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1879			" %hu\nTG Port Primary Access State: %s\nTG Port "
1880			"Primary Access Status: %s\nTG Port Secondary Access"
1881			" State: %s\nTG Port Secondary Access Status: %s\n",
1882			config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1883			core_alua_dump_state(
1884				tg_pt_gp->tg_pt_gp_alua_access_state),
1885			core_alua_dump_status(
1886				tg_pt_gp->tg_pt_gp_alua_access_status),
1887			atomic_read(&lun->lun_tg_pt_secondary_offline) ?
1888			"Offline" : "None",
1889			core_alua_dump_status(lun->lun_tg_pt_secondary_stat));
1890	}
1891	rcu_read_unlock();
1892
1893	return len;
1894}
1895
1896ssize_t core_alua_store_tg_pt_gp_info(
1897	struct se_lun *lun,
1898	const char *page,
1899	size_t count)
1900{
1901	struct se_portal_group *tpg = lun->lun_tpg;
1902	/*
1903	 * rcu_dereference_raw protected by se_lun->lun_group symlink
1904	 * reference to se_device->dev_group.
1905	 */
1906	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
1907	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1908	unsigned char buf[TG_PT_GROUP_NAME_BUF];
1909	int move = 0;
1910
1911	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
1912	    (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
1913		return -ENODEV;
1914
1915	if (count > TG_PT_GROUP_NAME_BUF) {
1916		pr_err("ALUA Target Port Group alias too large!\n");
1917		return -EINVAL;
1918	}
1919	memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1920	memcpy(buf, page, count);
1921	/*
1922	 * Any ALUA target port group alias besides "NULL" means we will be
1923	 * making a new group association.
1924	 */
1925	if (strcmp(strstrip(buf), "NULL")) {
1926		/*
1927		 * core_alua_get_tg_pt_gp_by_name() will increment reference to
1928		 * struct t10_alua_tg_pt_gp.  This reference is released with
1929		 * core_alua_put_tg_pt_gp_from_name() below.
1930		 */
1931		tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(dev,
1932					strstrip(buf));
1933		if (!tg_pt_gp_new)
1934			return -ENODEV;
1935	}
1936
1937	spin_lock(&lun->lun_tg_pt_gp_lock);
1938	tg_pt_gp = rcu_dereference_check(lun->lun_tg_pt_gp,
1939				lockdep_is_held(&lun->lun_tg_pt_gp_lock));
1940	if (tg_pt_gp) {
1941		/*
1942		 * Clearing an existing tg_pt_gp association, and replacing
1943		 * with the default_tg_pt_gp.
1944		 */
1945		if (!tg_pt_gp_new) {
1946			pr_debug("Target_Core_ConfigFS: Moving"
1947				" %s/tpgt_%hu/%s from ALUA Target Port Group:"
1948				" alua/%s, ID: %hu back to"
1949				" default_tg_pt_gp\n",
1950				tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1951				tpg->se_tpg_tfo->tpg_get_tag(tpg),
1952				config_item_name(&lun->lun_group.cg_item),
1953				config_item_name(
1954					&tg_pt_gp->tg_pt_gp_group.cg_item),
1955				tg_pt_gp->tg_pt_gp_id);
1956
1957			target_swap_tg_pt_gp(lun, tg_pt_gp,
1958					dev->t10_alua.default_tg_pt_gp);
1959			spin_unlock(&lun->lun_tg_pt_gp_lock);
1960
1961			goto sync_rcu;
1962		}
1963		move = 1;
1964	}
1965
1966	target_swap_tg_pt_gp(lun, tg_pt_gp, tg_pt_gp_new);
1967	spin_unlock(&lun->lun_tg_pt_gp_lock);
1968	pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
1969		" Target Port Group: alua/%s, ID: %hu\n", (move) ?
1970		"Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1971		tpg->se_tpg_tfo->tpg_get_tag(tpg),
1972		config_item_name(&lun->lun_group.cg_item),
1973		config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
1974		tg_pt_gp_new->tg_pt_gp_id);
1975
1976	core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1977sync_rcu:
1978	synchronize_rcu();
1979	return count;
1980}
1981
1982ssize_t core_alua_show_access_type(
1983	struct t10_alua_tg_pt_gp *tg_pt_gp,
1984	char *page)
1985{
1986	if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA) &&
1987	    (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA))
1988		return sprintf(page, "Implicit and Explicit\n");
1989	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA)
1990		return sprintf(page, "Implicit\n");
1991	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)
1992		return sprintf(page, "Explicit\n");
1993	else
1994		return sprintf(page, "None\n");
1995}
1996
1997ssize_t core_alua_store_access_type(
1998	struct t10_alua_tg_pt_gp *tg_pt_gp,
1999	const char *page,
2000	size_t count)
2001{
2002	unsigned long tmp;
2003	int ret;
2004
2005	ret = kstrtoul(page, 0, &tmp);
2006	if (ret < 0) {
2007		pr_err("Unable to extract alua_access_type\n");
2008		return ret;
2009	}
2010	if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
2011		pr_err("Illegal value for alua_access_type:"
2012				" %lu\n", tmp);
2013		return -EINVAL;
2014	}
2015	if (tmp == 3)
2016		tg_pt_gp->tg_pt_gp_alua_access_type =
2017			TPGS_IMPLICIT_ALUA | TPGS_EXPLICIT_ALUA;
2018	else if (tmp == 2)
2019		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICIT_ALUA;
2020	else if (tmp == 1)
2021		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICIT_ALUA;
2022	else
2023		tg_pt_gp->tg_pt_gp_alua_access_type = 0;
2024
2025	return count;
2026}
2027
2028ssize_t core_alua_show_nonop_delay_msecs(
2029	struct t10_alua_tg_pt_gp *tg_pt_gp,
2030	char *page)
2031{
2032	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
2033}
2034
2035ssize_t core_alua_store_nonop_delay_msecs(
2036	struct t10_alua_tg_pt_gp *tg_pt_gp,
2037	const char *page,
2038	size_t count)
2039{
2040	unsigned long tmp;
2041	int ret;
2042
2043	ret = kstrtoul(page, 0, &tmp);
2044	if (ret < 0) {
2045		pr_err("Unable to extract nonop_delay_msecs\n");
2046		return ret;
2047	}
2048	if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
2049		pr_err("Passed nonop_delay_msecs: %lu, exceeds"
2050			" ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
2051			ALUA_MAX_NONOP_DELAY_MSECS);
2052		return -EINVAL;
2053	}
2054	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
2055
2056	return count;
2057}
2058
2059ssize_t core_alua_show_trans_delay_msecs(
2060	struct t10_alua_tg_pt_gp *tg_pt_gp,
2061	char *page)
2062{
2063	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
2064}
2065
2066ssize_t core_alua_store_trans_delay_msecs(
2067	struct t10_alua_tg_pt_gp *tg_pt_gp,
2068	const char *page,
2069	size_t count)
2070{
2071	unsigned long tmp;
2072	int ret;
2073
2074	ret = kstrtoul(page, 0, &tmp);
2075	if (ret < 0) {
2076		pr_err("Unable to extract trans_delay_msecs\n");
2077		return ret;
2078	}
2079	if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
2080		pr_err("Passed trans_delay_msecs: %lu, exceeds"
2081			" ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
2082			ALUA_MAX_TRANS_DELAY_MSECS);
2083		return -EINVAL;
2084	}
2085	tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
2086
2087	return count;
2088}
2089
2090ssize_t core_alua_show_implicit_trans_secs(
2091	struct t10_alua_tg_pt_gp *tg_pt_gp,
2092	char *page)
2093{
2094	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_implicit_trans_secs);
2095}
2096
2097ssize_t core_alua_store_implicit_trans_secs(
2098	struct t10_alua_tg_pt_gp *tg_pt_gp,
2099	const char *page,
2100	size_t count)
2101{
2102	unsigned long tmp;
2103	int ret;
2104
2105	ret = kstrtoul(page, 0, &tmp);
2106	if (ret < 0) {
2107		pr_err("Unable to extract implicit_trans_secs\n");
2108		return ret;
2109	}
2110	if (tmp > ALUA_MAX_IMPLICIT_TRANS_SECS) {
2111		pr_err("Passed implicit_trans_secs: %lu, exceeds"
2112			" ALUA_MAX_IMPLICIT_TRANS_SECS: %d\n", tmp,
2113			ALUA_MAX_IMPLICIT_TRANS_SECS);
2114		return  -EINVAL;
2115	}
2116	tg_pt_gp->tg_pt_gp_implicit_trans_secs = (int)tmp;
2117
2118	return count;
2119}
2120
2121ssize_t core_alua_show_preferred_bit(
2122	struct t10_alua_tg_pt_gp *tg_pt_gp,
2123	char *page)
2124{
2125	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
2126}
2127
2128ssize_t core_alua_store_preferred_bit(
2129	struct t10_alua_tg_pt_gp *tg_pt_gp,
2130	const char *page,
2131	size_t count)
2132{
2133	unsigned long tmp;
2134	int ret;
2135
2136	ret = kstrtoul(page, 0, &tmp);
2137	if (ret < 0) {
2138		pr_err("Unable to extract preferred ALUA value\n");
2139		return ret;
2140	}
2141	if ((tmp != 0) && (tmp != 1)) {
2142		pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
2143		return -EINVAL;
2144	}
2145	tg_pt_gp->tg_pt_gp_pref = (int)tmp;
2146
2147	return count;
2148}
2149
2150ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
2151{
2152	return sprintf(page, "%d\n",
2153		atomic_read(&lun->lun_tg_pt_secondary_offline));
2154}
2155
2156ssize_t core_alua_store_offline_bit(
2157	struct se_lun *lun,
2158	const char *page,
2159	size_t count)
2160{
2161	/*
2162	 * rcu_dereference_raw protected by se_lun->lun_group symlink
2163	 * reference to se_device->dev_group.
2164	 */
2165	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
2166	unsigned long tmp;
2167	int ret;
2168
2169	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
2170	    (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
2171		return -ENODEV;
2172
2173	ret = kstrtoul(page, 0, &tmp);
2174	if (ret < 0) {
2175		pr_err("Unable to extract alua_tg_pt_offline value\n");
2176		return ret;
2177	}
2178	if ((tmp != 0) && (tmp != 1)) {
2179		pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
2180				tmp);
2181		return -EINVAL;
2182	}
2183
2184	ret = core_alua_set_tg_pt_secondary_state(lun, 0, (int)tmp);
2185	if (ret < 0)
2186		return -EINVAL;
2187
2188	return count;
2189}
2190
2191ssize_t core_alua_show_secondary_status(
2192	struct se_lun *lun,
2193	char *page)
2194{
2195	return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_stat);
2196}
2197
2198ssize_t core_alua_store_secondary_status(
2199	struct se_lun *lun,
2200	const char *page,
2201	size_t count)
2202{
2203	unsigned long tmp;
2204	int ret;
2205
2206	ret = kstrtoul(page, 0, &tmp);
2207	if (ret < 0) {
2208		pr_err("Unable to extract alua_tg_pt_status\n");
2209		return ret;
2210	}
2211	if ((tmp != ALUA_STATUS_NONE) &&
2212	    (tmp != ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
2213	    (tmp != ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA)) {
2214		pr_err("Illegal value for alua_tg_pt_status: %lu\n",
2215				tmp);
2216		return -EINVAL;
2217	}
2218	lun->lun_tg_pt_secondary_stat = (int)tmp;
2219
2220	return count;
2221}
2222
2223ssize_t core_alua_show_secondary_write_metadata(
2224	struct se_lun *lun,
2225	char *page)
2226{
2227	return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_write_md);
2228}
2229
2230ssize_t core_alua_store_secondary_write_metadata(
2231	struct se_lun *lun,
2232	const char *page,
2233	size_t count)
2234{
2235	unsigned long tmp;
2236	int ret;
2237
2238	ret = kstrtoul(page, 0, &tmp);
2239	if (ret < 0) {
2240		pr_err("Unable to extract alua_tg_pt_write_md\n");
2241		return ret;
2242	}
2243	if ((tmp != 0) && (tmp != 1)) {
2244		pr_err("Illegal value for alua_tg_pt_write_md:"
2245				" %lu\n", tmp);
2246		return -EINVAL;
2247	}
2248	lun->lun_tg_pt_secondary_write_md = (int)tmp;
2249
2250	return count;
2251}
2252
2253int core_setup_alua(struct se_device *dev)
2254{
2255	if (!(dev->transport_flags &
2256	     TRANSPORT_FLAG_PASSTHROUGH_ALUA) &&
2257	    !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)) {
2258		struct t10_alua_lu_gp_member *lu_gp_mem;
2259
2260		/*
2261		 * Associate this struct se_device with the default ALUA
2262		 * LUN Group.
2263		 */
2264		lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2265		if (IS_ERR(lu_gp_mem))
2266			return PTR_ERR(lu_gp_mem);
2267
2268		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2269		__core_alua_attach_lu_gp_mem(lu_gp_mem,
2270				default_lu_gp);
2271		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2272
2273		pr_debug("%s: Adding to default ALUA LU Group:"
2274			" core/alua/lu_gps/default_lu_gp\n",
2275			dev->transport->name);
2276	}
2277
2278	return 0;
2279}