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 <linux/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_tpg->tpg_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_tpg->tpg_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}
 
 853
 854static int core_alua_write_tpg_metadata(
 855	const char *path,
 856	unsigned char *md_buf,
 857	u32 md_buf_len)
 858{
 859	struct file *file = filp_open(path, O_RDWR | O_CREAT | O_TRUNC, 0600);
 860	loff_t pos = 0;
 861	int ret;
 862
 863	if (IS_ERR(file)) {
 864		pr_err("filp_open(%s) for ALUA metadata failed\n", path);
 865		return -ENODEV;
 866	}
 867	ret = kernel_write(file, md_buf, md_buf_len, &pos);
 868	if (ret < 0)
 869		pr_err("Error writing ALUA metadata file: %s\n", path);
 870	fput(file);
 871	return (ret < 0) ? -EIO : 0;
 872}
 873
 
 
 
 874static int core_alua_update_tpg_primary_metadata(
 875	struct t10_alua_tg_pt_gp *tg_pt_gp)
 876{
 877	unsigned char *md_buf;
 878	struct t10_wwn *wwn = &tg_pt_gp->tg_pt_gp_dev->t10_wwn;
 879	char *path;
 880	int len, rc;
 881
 882	lockdep_assert_held(&tg_pt_gp->tg_pt_gp_transition_mutex);
 883
 884	md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
 885	if (!md_buf) {
 886		pr_err("Unable to allocate buf for ALUA metadata\n");
 887		return -ENOMEM;
 888	}
 889
 890	len = snprintf(md_buf, ALUA_MD_BUF_LEN,
 891			"tg_pt_gp_id=%hu\n"
 892			"alua_access_state=0x%02x\n"
 893			"alua_access_status=0x%02x\n",
 894			tg_pt_gp->tg_pt_gp_id,
 895			tg_pt_gp->tg_pt_gp_alua_access_state,
 896			tg_pt_gp->tg_pt_gp_alua_access_status);
 897
 898	rc = -ENOMEM;
 899	path = kasprintf(GFP_KERNEL, "%s/alua/tpgs_%s/%s", db_root,
 900			&wwn->unit_serial[0],
 901			config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
 902	if (path) {
 903		rc = core_alua_write_tpg_metadata(path, md_buf, len);
 904		kfree(path);
 905	}
 906	kfree(md_buf);
 907	return rc;
 908}
 909
 910static void core_alua_queue_state_change_ua(struct t10_alua_tg_pt_gp *tg_pt_gp)
 911{
 912	struct se_dev_entry *se_deve;
 913	struct se_lun *lun;
 914	struct se_lun_acl *lacl;
 915
 916	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 917	list_for_each_entry(lun, &tg_pt_gp->tg_pt_gp_lun_list,
 918				lun_tg_pt_gp_link) {
 919		/*
 920		 * After an implicit target port asymmetric access state
 921		 * change, a device server shall establish a unit attention
 922		 * condition for the initiator port associated with every I_T
 923		 * nexus with the additional sense code set to ASYMMETRIC
 924		 * ACCESS STATE CHANGED.
 925		 *
 926		 * After an explicit target port asymmetric access state
 927		 * change, a device server shall establish a unit attention
 928		 * condition with the additional sense code set to ASYMMETRIC
 929		 * ACCESS STATE CHANGED for the initiator port associated with
 930		 * every I_T nexus other than the I_T nexus on which the SET
 931		 * TARGET PORT GROUPS command
 932		 */
 933		if (!percpu_ref_tryget_live(&lun->lun_ref))
 934			continue;
 935		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 936
 937		spin_lock(&lun->lun_deve_lock);
 938		list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link) {
 939			lacl = se_deve->se_lun_acl;
 
 940
 941			/*
 942			 * spc4r37 p.242:
 943			 * After an explicit target port asymmetric access
 944			 * state change, a device server shall establish a
 945			 * unit attention condition with the additional sense
 946			 * code set to ASYMMETRIC ACCESS STATE CHANGED for
 947			 * the initiator port associated with every I_T nexus
 948			 * other than the I_T nexus on which the SET TARGET
 949			 * PORT GROUPS command was received.
 950			 */
 951			if ((tg_pt_gp->tg_pt_gp_alua_access_status ==
 952			     ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
 953			   (tg_pt_gp->tg_pt_gp_alua_lun != NULL) &&
 954			    (tg_pt_gp->tg_pt_gp_alua_lun == lun))
 955				continue;
 956
 957			/*
 958			 * se_deve->se_lun_acl pointer may be NULL for a
 959			 * entry created without explicit Node+MappedLUN ACLs
 960			 */
 961			if (lacl && (tg_pt_gp->tg_pt_gp_alua_nacl != NULL) &&
 962			    (tg_pt_gp->tg_pt_gp_alua_nacl == lacl->se_lun_nacl))
 963				continue;
 964
 965			core_scsi3_ua_allocate(se_deve, 0x2A,
 966				ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
 967		}
 968		spin_unlock(&lun->lun_deve_lock);
 969
 970		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
 971		percpu_ref_put(&lun->lun_ref);
 972	}
 973	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 974}
 975
 976static int core_alua_do_transition_tg_pt(
 977	struct t10_alua_tg_pt_gp *tg_pt_gp,
 978	int new_state,
 979	int explicit)
 980{
 981	int prev_state;
 982
 983	mutex_lock(&tg_pt_gp->tg_pt_gp_transition_mutex);
 984	/* Nothing to be done here */
 985	if (tg_pt_gp->tg_pt_gp_alua_access_state == new_state) {
 986		mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
 987		return 0;
 988	}
 989
 990	if (explicit && new_state == ALUA_ACCESS_STATE_TRANSITION) {
 991		mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
 992		return -EAGAIN;
 993	}
 994
 995	/*
 996	 * Save the old primary ALUA access state, and set the current state
 997	 * to ALUA_ACCESS_STATE_TRANSITION.
 998	 */
 999	prev_state = tg_pt_gp->tg_pt_gp_alua_access_state;
1000	tg_pt_gp->tg_pt_gp_alua_access_state = ALUA_ACCESS_STATE_TRANSITION;
1001	tg_pt_gp->tg_pt_gp_alua_access_status = (explicit) ?
1002				ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
1003				ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
1004
1005	core_alua_queue_state_change_ua(tg_pt_gp);
1006
1007	if (new_state == ALUA_ACCESS_STATE_TRANSITION) {
1008		mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1009		return 0;
1010	}
1011
1012	/*
1013	 * Check for the optional ALUA primary state transition delay
1014	 */
1015	if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
1016		msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
1017
1018	/*
1019	 * Set the current primary ALUA access state to the requested new state
1020	 */
1021	tg_pt_gp->tg_pt_gp_alua_access_state = new_state;
1022
1023	/*
1024	 * Update the ALUA metadata buf that has been allocated in
1025	 * core_alua_do_port_transition(), this metadata will be written
1026	 * to struct file.
1027	 *
1028	 * Note that there is the case where we do not want to update the
1029	 * metadata when the saved metadata is being parsed in userspace
1030	 * when setting the existing port access state and access status.
1031	 *
1032	 * Also note that the failure to write out the ALUA metadata to
1033	 * struct file does NOT affect the actual ALUA transition.
1034	 */
1035	if (tg_pt_gp->tg_pt_gp_write_metadata) {
1036		core_alua_update_tpg_primary_metadata(tg_pt_gp);
1037	}
1038
1039	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1040		" from primary access state %s to %s\n", (explicit) ? "explicit" :
1041		"implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1042		tg_pt_gp->tg_pt_gp_id,
1043		core_alua_dump_state(prev_state),
1044		core_alua_dump_state(new_state));
1045
1046	core_alua_queue_state_change_ua(tg_pt_gp);
1047
1048	mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
1049	return 0;
1050}
1051
1052int core_alua_do_port_transition(
1053	struct t10_alua_tg_pt_gp *l_tg_pt_gp,
1054	struct se_device *l_dev,
1055	struct se_lun *l_lun,
1056	struct se_node_acl *l_nacl,
1057	int new_state,
1058	int explicit)
1059{
1060	struct se_device *dev;
1061	struct t10_alua_lu_gp *lu_gp;
1062	struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
1063	struct t10_alua_tg_pt_gp *tg_pt_gp;
1064	int primary, valid_states, rc = 0;
1065
1066	if (l_dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
1067		return -ENODEV;
1068
1069	valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
1070	if (core_alua_check_transition(new_state, valid_states, &primary,
1071				       explicit) != 0)
1072		return -EINVAL;
1073
1074	local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
1075	spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
1076	lu_gp = local_lu_gp_mem->lu_gp;
1077	atomic_inc(&lu_gp->lu_gp_ref_cnt);
1078	spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
1079	/*
1080	 * For storage objects that are members of the 'default_lu_gp',
1081	 * we only do transition on the passed *l_tp_pt_gp, and not
1082	 * on all of the matching target port groups IDs in default_lu_gp.
1083	 */
1084	if (!lu_gp->lu_gp_id) {
1085		/*
1086		 * core_alua_do_transition_tg_pt() will always return
1087		 * success.
1088		 */
1089		l_tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
1090		l_tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
1091		rc = core_alua_do_transition_tg_pt(l_tg_pt_gp,
1092						   new_state, explicit);
1093		atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
1094		return rc;
1095	}
1096	/*
1097	 * For all other LU groups aside from 'default_lu_gp', walk all of
1098	 * the associated storage objects looking for a matching target port
1099	 * group ID from the local target port group.
1100	 */
1101	spin_lock(&lu_gp->lu_gp_lock);
1102	list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
1103				lu_gp_mem_list) {
1104
1105		dev = lu_gp_mem->lu_gp_mem_dev;
1106		atomic_inc_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
1107		spin_unlock(&lu_gp->lu_gp_lock);
1108
1109		spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1110		list_for_each_entry(tg_pt_gp,
1111				&dev->t10_alua.tg_pt_gps_list,
1112				tg_pt_gp_list) {
1113
1114			if (!tg_pt_gp->tg_pt_gp_valid_id)
1115				continue;
1116			/*
1117			 * If the target behavior port asymmetric access state
1118			 * is changed for any target port group accessible via
1119			 * a logical unit within a LU group, the target port
1120			 * behavior group asymmetric access states for the same
1121			 * target port group accessible via other logical units
1122			 * in that LU group will also change.
1123			 */
1124			if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
1125				continue;
1126
1127			if (l_tg_pt_gp == tg_pt_gp) {
1128				tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
1129				tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
1130			} else {
1131				tg_pt_gp->tg_pt_gp_alua_lun = NULL;
1132				tg_pt_gp->tg_pt_gp_alua_nacl = NULL;
1133			}
1134			atomic_inc_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
1135			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1136			/*
1137			 * core_alua_do_transition_tg_pt() will always return
1138			 * success.
1139			 */
1140			rc = core_alua_do_transition_tg_pt(tg_pt_gp,
1141					new_state, explicit);
1142
1143			spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1144			atomic_dec_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
1145			if (rc)
1146				break;
1147		}
1148		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1149
1150		spin_lock(&lu_gp->lu_gp_lock);
1151		atomic_dec_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
1152	}
1153	spin_unlock(&lu_gp->lu_gp_lock);
1154
1155	if (!rc) {
1156		pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
1157			 " Group IDs: %hu %s transition to primary state: %s\n",
1158			 config_item_name(&lu_gp->lu_gp_group.cg_item),
1159			 l_tg_pt_gp->tg_pt_gp_id,
1160			 (explicit) ? "explicit" : "implicit",
1161			 core_alua_dump_state(new_state));
1162	}
1163
1164	atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
1165	return rc;
1166}
1167
1168static int core_alua_update_tpg_secondary_metadata(struct se_lun *lun)
1169{
1170	struct se_portal_group *se_tpg = lun->lun_tpg;
1171	unsigned char *md_buf;
1172	char *path;
1173	int len, rc;
1174
1175	mutex_lock(&lun->lun_tg_pt_md_mutex);
1176
1177	md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
1178	if (!md_buf) {
1179		pr_err("Unable to allocate buf for ALUA metadata\n");
1180		rc = -ENOMEM;
1181		goto out_unlock;
1182	}
1183
1184	len = snprintf(md_buf, ALUA_MD_BUF_LEN, "alua_tg_pt_offline=%d\n"
1185			"alua_tg_pt_status=0x%02x\n",
1186			atomic_read(&lun->lun_tg_pt_secondary_offline),
1187			lun->lun_tg_pt_secondary_stat);
1188
1189	if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL) {
1190		path = kasprintf(GFP_KERNEL, "%s/alua/%s/%s+%hu/lun_%llu",
1191				db_root, se_tpg->se_tpg_tfo->fabric_name,
1192				se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg),
1193				se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg),
1194				lun->unpacked_lun);
1195	} else {
1196		path = kasprintf(GFP_KERNEL, "%s/alua/%s/%s/lun_%llu",
1197				db_root, se_tpg->se_tpg_tfo->fabric_name,
1198				se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg),
1199				lun->unpacked_lun);
1200	}
1201	if (!path) {
1202		rc = -ENOMEM;
1203		goto out_free;
1204	}
1205
1206	rc = core_alua_write_tpg_metadata(path, md_buf, len);
1207	kfree(path);
1208out_free:
1209	kfree(md_buf);
1210out_unlock:
1211	mutex_unlock(&lun->lun_tg_pt_md_mutex);
1212	return rc;
1213}
1214
1215static int core_alua_set_tg_pt_secondary_state(
1216	struct se_lun *lun,
1217	int explicit,
1218	int offline)
1219{
1220	struct t10_alua_tg_pt_gp *tg_pt_gp;
1221	int trans_delay_msecs;
1222
1223	rcu_read_lock();
1224	tg_pt_gp = rcu_dereference(lun->lun_tg_pt_gp);
1225	if (!tg_pt_gp) {
1226		rcu_read_unlock();
1227		pr_err("Unable to complete secondary state"
1228				" transition\n");
1229		return -EINVAL;
1230	}
1231	trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
1232	/*
1233	 * Set the secondary ALUA target port access state to OFFLINE
1234	 * or release the previously secondary state for struct se_lun
1235	 */
1236	if (offline)
1237		atomic_set(&lun->lun_tg_pt_secondary_offline, 1);
1238	else
1239		atomic_set(&lun->lun_tg_pt_secondary_offline, 0);
1240
1241	lun->lun_tg_pt_secondary_stat = (explicit) ?
1242			ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
1243			ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
1244
1245	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
1246		" to secondary access state: %s\n", (explicit) ? "explicit" :
1247		"implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
1248		tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
1249
1250	rcu_read_unlock();
1251	/*
1252	 * Do the optional transition delay after we set the secondary
1253	 * ALUA access state.
1254	 */
1255	if (trans_delay_msecs != 0)
1256		msleep_interruptible(trans_delay_msecs);
1257	/*
1258	 * See if we need to update the ALUA fabric port metadata for
1259	 * secondary state and status
1260	 */
1261	if (lun->lun_tg_pt_secondary_write_md)
1262		core_alua_update_tpg_secondary_metadata(lun);
1263
1264	return 0;
1265}
1266
1267struct t10_alua_lba_map *
1268core_alua_allocate_lba_map(struct list_head *list,
1269			   u64 first_lba, u64 last_lba)
1270{
1271	struct t10_alua_lba_map *lba_map;
1272
1273	lba_map = kmem_cache_zalloc(t10_alua_lba_map_cache, GFP_KERNEL);
1274	if (!lba_map) {
1275		pr_err("Unable to allocate struct t10_alua_lba_map\n");
1276		return ERR_PTR(-ENOMEM);
1277	}
1278	INIT_LIST_HEAD(&lba_map->lba_map_mem_list);
1279	lba_map->lba_map_first_lba = first_lba;
1280	lba_map->lba_map_last_lba = last_lba;
1281
1282	list_add_tail(&lba_map->lba_map_list, list);
1283	return lba_map;
1284}
1285
1286int
1287core_alua_allocate_lba_map_mem(struct t10_alua_lba_map *lba_map,
1288			       int pg_id, int state)
1289{
1290	struct t10_alua_lba_map_member *lba_map_mem;
1291
1292	list_for_each_entry(lba_map_mem, &lba_map->lba_map_mem_list,
1293			    lba_map_mem_list) {
1294		if (lba_map_mem->lba_map_mem_alua_pg_id == pg_id) {
1295			pr_err("Duplicate pg_id %d in lba_map\n", pg_id);
1296			return -EINVAL;
1297		}
1298	}
1299
1300	lba_map_mem = kmem_cache_zalloc(t10_alua_lba_map_mem_cache, GFP_KERNEL);
1301	if (!lba_map_mem) {
1302		pr_err("Unable to allocate struct t10_alua_lba_map_mem\n");
1303		return -ENOMEM;
1304	}
1305	lba_map_mem->lba_map_mem_alua_state = state;
1306	lba_map_mem->lba_map_mem_alua_pg_id = pg_id;
1307
1308	list_add_tail(&lba_map_mem->lba_map_mem_list,
1309		      &lba_map->lba_map_mem_list);
1310	return 0;
1311}
1312
1313void
1314core_alua_free_lba_map(struct list_head *lba_list)
1315{
1316	struct t10_alua_lba_map *lba_map, *lba_map_tmp;
1317	struct t10_alua_lba_map_member *lba_map_mem, *lba_map_mem_tmp;
1318
1319	list_for_each_entry_safe(lba_map, lba_map_tmp, lba_list,
1320				 lba_map_list) {
1321		list_for_each_entry_safe(lba_map_mem, lba_map_mem_tmp,
1322					 &lba_map->lba_map_mem_list,
1323					 lba_map_mem_list) {
1324			list_del(&lba_map_mem->lba_map_mem_list);
1325			kmem_cache_free(t10_alua_lba_map_mem_cache,
1326					lba_map_mem);
1327		}
1328		list_del(&lba_map->lba_map_list);
1329		kmem_cache_free(t10_alua_lba_map_cache, lba_map);
1330	}
1331}
1332
1333void
1334core_alua_set_lba_map(struct se_device *dev, struct list_head *lba_map_list,
1335		      int segment_size, int segment_mult)
1336{
1337	struct list_head old_lba_map_list;
1338	struct t10_alua_tg_pt_gp *tg_pt_gp;
1339	int activate = 0, supported;
1340
1341	INIT_LIST_HEAD(&old_lba_map_list);
1342	spin_lock(&dev->t10_alua.lba_map_lock);
1343	dev->t10_alua.lba_map_segment_size = segment_size;
1344	dev->t10_alua.lba_map_segment_multiplier = segment_mult;
1345	list_splice_init(&dev->t10_alua.lba_map_list, &old_lba_map_list);
1346	if (lba_map_list) {
1347		list_splice_init(lba_map_list, &dev->t10_alua.lba_map_list);
1348		activate = 1;
1349	}
1350	spin_unlock(&dev->t10_alua.lba_map_lock);
1351	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1352	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
1353			    tg_pt_gp_list) {
1354
1355		if (!tg_pt_gp->tg_pt_gp_valid_id)
1356			continue;
1357		supported = tg_pt_gp->tg_pt_gp_alua_supported_states;
1358		if (activate)
1359			supported |= ALUA_LBD_SUP;
1360		else
1361			supported &= ~ALUA_LBD_SUP;
1362		tg_pt_gp->tg_pt_gp_alua_supported_states = supported;
1363	}
1364	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1365	core_alua_free_lba_map(&old_lba_map_list);
1366}
1367
1368struct t10_alua_lu_gp *
1369core_alua_allocate_lu_gp(const char *name, int def_group)
1370{
1371	struct t10_alua_lu_gp *lu_gp;
1372
1373	lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
1374	if (!lu_gp) {
1375		pr_err("Unable to allocate struct t10_alua_lu_gp\n");
1376		return ERR_PTR(-ENOMEM);
1377	}
1378	INIT_LIST_HEAD(&lu_gp->lu_gp_node);
1379	INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
1380	spin_lock_init(&lu_gp->lu_gp_lock);
1381	atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
1382
1383	if (def_group) {
1384		lu_gp->lu_gp_id = alua_lu_gps_counter++;
1385		lu_gp->lu_gp_valid_id = 1;
1386		alua_lu_gps_count++;
1387	}
1388
1389	return lu_gp;
1390}
1391
1392int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
1393{
1394	struct t10_alua_lu_gp *lu_gp_tmp;
1395	u16 lu_gp_id_tmp;
1396	/*
1397	 * The lu_gp->lu_gp_id may only be set once..
1398	 */
1399	if (lu_gp->lu_gp_valid_id) {
1400		pr_warn("ALUA LU Group already has a valid ID,"
1401			" ignoring request\n");
1402		return -EINVAL;
1403	}
1404
1405	spin_lock(&lu_gps_lock);
1406	if (alua_lu_gps_count == 0x0000ffff) {
1407		pr_err("Maximum ALUA alua_lu_gps_count:"
1408				" 0x0000ffff reached\n");
1409		spin_unlock(&lu_gps_lock);
1410		kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1411		return -ENOSPC;
1412	}
1413again:
1414	lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
1415				alua_lu_gps_counter++;
1416
1417	list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
1418		if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
1419			if (!lu_gp_id)
1420				goto again;
1421
1422			pr_warn("ALUA Logical Unit Group ID: %hu"
1423				" already exists, ignoring request\n",
1424				lu_gp_id);
1425			spin_unlock(&lu_gps_lock);
1426			return -EINVAL;
1427		}
1428	}
1429
1430	lu_gp->lu_gp_id = lu_gp_id_tmp;
1431	lu_gp->lu_gp_valid_id = 1;
1432	list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
1433	alua_lu_gps_count++;
1434	spin_unlock(&lu_gps_lock);
1435
1436	return 0;
1437}
1438
1439static struct t10_alua_lu_gp_member *
1440core_alua_allocate_lu_gp_mem(struct se_device *dev)
1441{
1442	struct t10_alua_lu_gp_member *lu_gp_mem;
1443
1444	lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
1445	if (!lu_gp_mem) {
1446		pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
1447		return ERR_PTR(-ENOMEM);
1448	}
1449	INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
1450	spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
1451	atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
1452
1453	lu_gp_mem->lu_gp_mem_dev = dev;
1454	dev->dev_alua_lu_gp_mem = lu_gp_mem;
1455
1456	return lu_gp_mem;
1457}
1458
1459void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
1460{
1461	struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
1462	/*
1463	 * Once we have reached this point, config_item_put() has
1464	 * already been called from target_core_alua_drop_lu_gp().
1465	 *
1466	 * Here, we remove the *lu_gp from the global list so that
1467	 * no associations can be made while we are releasing
1468	 * struct t10_alua_lu_gp.
1469	 */
1470	spin_lock(&lu_gps_lock);
1471	list_del(&lu_gp->lu_gp_node);
1472	alua_lu_gps_count--;
1473	spin_unlock(&lu_gps_lock);
1474	/*
1475	 * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
1476	 * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
1477	 * released with core_alua_put_lu_gp_from_name()
1478	 */
1479	while (atomic_read(&lu_gp->lu_gp_ref_cnt))
1480		cpu_relax();
1481	/*
1482	 * Release reference to struct t10_alua_lu_gp * from all associated
1483	 * struct se_device.
1484	 */
1485	spin_lock(&lu_gp->lu_gp_lock);
1486	list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
1487				&lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
1488		if (lu_gp_mem->lu_gp_assoc) {
1489			list_del(&lu_gp_mem->lu_gp_mem_list);
1490			lu_gp->lu_gp_members--;
1491			lu_gp_mem->lu_gp_assoc = 0;
1492		}
1493		spin_unlock(&lu_gp->lu_gp_lock);
1494		/*
1495		 *
1496		 * lu_gp_mem is associated with a single
1497		 * struct se_device->dev_alua_lu_gp_mem, and is released when
1498		 * struct se_device is released via core_alua_free_lu_gp_mem().
1499		 *
1500		 * If the passed lu_gp does NOT match the default_lu_gp, assume
1501		 * we want to re-associate a given lu_gp_mem with default_lu_gp.
1502		 */
1503		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1504		if (lu_gp != default_lu_gp)
1505			__core_alua_attach_lu_gp_mem(lu_gp_mem,
1506					default_lu_gp);
1507		else
1508			lu_gp_mem->lu_gp = NULL;
1509		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1510
1511		spin_lock(&lu_gp->lu_gp_lock);
1512	}
1513	spin_unlock(&lu_gp->lu_gp_lock);
1514
1515	kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
1516}
1517
1518void core_alua_free_lu_gp_mem(struct se_device *dev)
1519{
1520	struct t10_alua_lu_gp *lu_gp;
1521	struct t10_alua_lu_gp_member *lu_gp_mem;
1522
1523	lu_gp_mem = dev->dev_alua_lu_gp_mem;
1524	if (!lu_gp_mem)
1525		return;
1526
1527	while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
1528		cpu_relax();
1529
1530	spin_lock(&lu_gp_mem->lu_gp_mem_lock);
1531	lu_gp = lu_gp_mem->lu_gp;
1532	if (lu_gp) {
1533		spin_lock(&lu_gp->lu_gp_lock);
1534		if (lu_gp_mem->lu_gp_assoc) {
1535			list_del(&lu_gp_mem->lu_gp_mem_list);
1536			lu_gp->lu_gp_members--;
1537			lu_gp_mem->lu_gp_assoc = 0;
1538		}
1539		spin_unlock(&lu_gp->lu_gp_lock);
1540		lu_gp_mem->lu_gp = NULL;
1541	}
1542	spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
1543
1544	kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
1545}
1546
1547struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
1548{
1549	struct t10_alua_lu_gp *lu_gp;
1550	struct config_item *ci;
1551
1552	spin_lock(&lu_gps_lock);
1553	list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
1554		if (!lu_gp->lu_gp_valid_id)
1555			continue;
1556		ci = &lu_gp->lu_gp_group.cg_item;
1557		if (!strcmp(config_item_name(ci), name)) {
1558			atomic_inc(&lu_gp->lu_gp_ref_cnt);
1559			spin_unlock(&lu_gps_lock);
1560			return lu_gp;
1561		}
1562	}
1563	spin_unlock(&lu_gps_lock);
1564
1565	return NULL;
1566}
1567
1568void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
1569{
1570	spin_lock(&lu_gps_lock);
1571	atomic_dec(&lu_gp->lu_gp_ref_cnt);
1572	spin_unlock(&lu_gps_lock);
1573}
1574
1575/*
1576 * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1577 */
1578void __core_alua_attach_lu_gp_mem(
1579	struct t10_alua_lu_gp_member *lu_gp_mem,
1580	struct t10_alua_lu_gp *lu_gp)
1581{
1582	spin_lock(&lu_gp->lu_gp_lock);
1583	lu_gp_mem->lu_gp = lu_gp;
1584	lu_gp_mem->lu_gp_assoc = 1;
1585	list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
1586	lu_gp->lu_gp_members++;
1587	spin_unlock(&lu_gp->lu_gp_lock);
1588}
1589
1590/*
1591 * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
1592 */
1593void __core_alua_drop_lu_gp_mem(
1594	struct t10_alua_lu_gp_member *lu_gp_mem,
1595	struct t10_alua_lu_gp *lu_gp)
1596{
1597	spin_lock(&lu_gp->lu_gp_lock);
1598	list_del(&lu_gp_mem->lu_gp_mem_list);
1599	lu_gp_mem->lu_gp = NULL;
1600	lu_gp_mem->lu_gp_assoc = 0;
1601	lu_gp->lu_gp_members--;
1602	spin_unlock(&lu_gp->lu_gp_lock);
1603}
1604
1605struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(struct se_device *dev,
1606		const char *name, int def_group)
1607{
1608	struct t10_alua_tg_pt_gp *tg_pt_gp;
1609
1610	tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
1611	if (!tg_pt_gp) {
1612		pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
1613		return NULL;
1614	}
1615	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
1616	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_lun_list);
1617	mutex_init(&tg_pt_gp->tg_pt_gp_transition_mutex);
1618	spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
1619	atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
1620	tg_pt_gp->tg_pt_gp_dev = dev;
1621	tg_pt_gp->tg_pt_gp_alua_access_state =
1622			ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED;
1623	/*
1624	 * Enable both explicit and implicit ALUA support by default
1625	 */
1626	tg_pt_gp->tg_pt_gp_alua_access_type =
1627			TPGS_EXPLICIT_ALUA | TPGS_IMPLICIT_ALUA;
1628	/*
1629	 * Set the default Active/NonOptimized Delay in milliseconds
1630	 */
1631	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
1632	tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
1633	tg_pt_gp->tg_pt_gp_implicit_trans_secs = ALUA_DEFAULT_IMPLICIT_TRANS_SECS;
1634
1635	/*
1636	 * Enable all supported states
1637	 */
1638	tg_pt_gp->tg_pt_gp_alua_supported_states =
1639	    ALUA_T_SUP | ALUA_O_SUP |
1640	    ALUA_U_SUP | ALUA_S_SUP | ALUA_AN_SUP | ALUA_AO_SUP;
1641
1642	if (def_group) {
1643		spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1644		tg_pt_gp->tg_pt_gp_id =
1645				dev->t10_alua.alua_tg_pt_gps_counter++;
1646		tg_pt_gp->tg_pt_gp_valid_id = 1;
1647		dev->t10_alua.alua_tg_pt_gps_count++;
1648		list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1649			      &dev->t10_alua.tg_pt_gps_list);
1650		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1651	}
1652
1653	return tg_pt_gp;
1654}
1655
1656int core_alua_set_tg_pt_gp_id(
1657	struct t10_alua_tg_pt_gp *tg_pt_gp,
1658	u16 tg_pt_gp_id)
1659{
1660	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1661	struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
1662	u16 tg_pt_gp_id_tmp;
1663
1664	/*
1665	 * The tg_pt_gp->tg_pt_gp_id may only be set once..
1666	 */
1667	if (tg_pt_gp->tg_pt_gp_valid_id) {
1668		pr_warn("ALUA TG PT Group already has a valid ID,"
1669			" ignoring request\n");
1670		return -EINVAL;
1671	}
1672
1673	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1674	if (dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
1675		pr_err("Maximum ALUA alua_tg_pt_gps_count:"
1676			" 0x0000ffff reached\n");
1677		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
 
1678		return -ENOSPC;
1679	}
1680again:
1681	tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
1682			dev->t10_alua.alua_tg_pt_gps_counter++;
1683
1684	list_for_each_entry(tg_pt_gp_tmp, &dev->t10_alua.tg_pt_gps_list,
1685			tg_pt_gp_list) {
1686		if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
1687			if (!tg_pt_gp_id)
1688				goto again;
1689
1690			pr_err("ALUA Target Port Group ID: %hu already"
1691				" exists, ignoring request\n", tg_pt_gp_id);
1692			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1693			return -EINVAL;
1694		}
1695	}
1696
1697	tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
1698	tg_pt_gp->tg_pt_gp_valid_id = 1;
1699	list_add_tail(&tg_pt_gp->tg_pt_gp_list,
1700			&dev->t10_alua.tg_pt_gps_list);
1701	dev->t10_alua.alua_tg_pt_gps_count++;
1702	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1703
1704	return 0;
1705}
1706
1707void core_alua_free_tg_pt_gp(
1708	struct t10_alua_tg_pt_gp *tg_pt_gp)
1709{
1710	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1711	struct se_lun *lun, *next;
1712
1713	/*
1714	 * Once we have reached this point, config_item_put() has already
1715	 * been called from target_core_alua_drop_tg_pt_gp().
1716	 *
1717	 * Here we remove *tg_pt_gp from the global list so that
1718	 * no associations *OR* explicit ALUA via SET_TARGET_PORT_GROUPS
1719	 * can be made while we are releasing struct t10_alua_tg_pt_gp.
1720	 */
1721	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1722	if (tg_pt_gp->tg_pt_gp_valid_id) {
1723		list_del(&tg_pt_gp->tg_pt_gp_list);
1724		dev->t10_alua.alua_tg_pt_gps_count--;
1725	}
1726	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1727
1728	/*
1729	 * Allow a struct t10_alua_tg_pt_gp_member * referenced by
1730	 * core_alua_get_tg_pt_gp_by_name() in
1731	 * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
1732	 * to be released with core_alua_put_tg_pt_gp_from_name().
1733	 */
1734	while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
1735		cpu_relax();
1736
1737	/*
1738	 * Release reference to struct t10_alua_tg_pt_gp from all associated
1739	 * struct se_port.
1740	 */
1741	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1742	list_for_each_entry_safe(lun, next,
1743			&tg_pt_gp->tg_pt_gp_lun_list, lun_tg_pt_gp_link) {
1744		list_del_init(&lun->lun_tg_pt_gp_link);
1745		tg_pt_gp->tg_pt_gp_members--;
1746
1747		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1748		/*
1749		 * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
1750		 * assume we want to re-associate a given tg_pt_gp_mem with
1751		 * default_tg_pt_gp.
1752		 */
1753		spin_lock(&lun->lun_tg_pt_gp_lock);
1754		if (tg_pt_gp != dev->t10_alua.default_tg_pt_gp) {
1755			__target_attach_tg_pt_gp(lun,
1756					dev->t10_alua.default_tg_pt_gp);
1757		} else
1758			rcu_assign_pointer(lun->lun_tg_pt_gp, NULL);
1759		spin_unlock(&lun->lun_tg_pt_gp_lock);
1760
1761		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1762	}
1763	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1764
1765	synchronize_rcu();
1766	kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
1767}
1768
1769static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
1770		struct se_device *dev, const char *name)
1771{
1772	struct t10_alua_tg_pt_gp *tg_pt_gp;
1773	struct config_item *ci;
1774
1775	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1776	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
1777			tg_pt_gp_list) {
1778		if (!tg_pt_gp->tg_pt_gp_valid_id)
1779			continue;
1780		ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1781		if (!strcmp(config_item_name(ci), name)) {
1782			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
1783			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1784			return tg_pt_gp;
1785		}
1786	}
1787	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1788
1789	return NULL;
1790}
1791
1792static void core_alua_put_tg_pt_gp_from_name(
1793	struct t10_alua_tg_pt_gp *tg_pt_gp)
1794{
1795	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
1796
1797	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
1798	atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
1799	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
1800}
1801
1802static void __target_attach_tg_pt_gp(struct se_lun *lun,
1803		struct t10_alua_tg_pt_gp *tg_pt_gp)
1804{
1805	struct se_dev_entry *se_deve;
1806
1807	assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1808
1809	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1810	rcu_assign_pointer(lun->lun_tg_pt_gp, tg_pt_gp);
1811	list_add_tail(&lun->lun_tg_pt_gp_link, &tg_pt_gp->tg_pt_gp_lun_list);
1812	tg_pt_gp->tg_pt_gp_members++;
1813	spin_lock(&lun->lun_deve_lock);
1814	list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link)
1815		core_scsi3_ua_allocate(se_deve, 0x3f,
1816				       ASCQ_3FH_INQUIRY_DATA_HAS_CHANGED);
1817	spin_unlock(&lun->lun_deve_lock);
1818	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
1819}
1820
1821void target_attach_tg_pt_gp(struct se_lun *lun,
1822		struct t10_alua_tg_pt_gp *tg_pt_gp)
1823{
1824	spin_lock(&lun->lun_tg_pt_gp_lock);
1825	__target_attach_tg_pt_gp(lun, tg_pt_gp);
1826	spin_unlock(&lun->lun_tg_pt_gp_lock);
1827	synchronize_rcu();
1828}
1829
1830static void __target_detach_tg_pt_gp(struct se_lun *lun,
1831		struct t10_alua_tg_pt_gp *tg_pt_gp)
1832{
1833	assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1834
1835	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
1836	list_del_init(&lun->lun_tg_pt_gp_link);
1837	tg_pt_gp->tg_pt_gp_members--;
1838	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
 
 
1839}
1840
1841void target_detach_tg_pt_gp(struct se_lun *lun)
1842{
1843	struct t10_alua_tg_pt_gp *tg_pt_gp;
1844
1845	spin_lock(&lun->lun_tg_pt_gp_lock);
1846	tg_pt_gp = rcu_dereference_check(lun->lun_tg_pt_gp,
1847				lockdep_is_held(&lun->lun_tg_pt_gp_lock));
1848	if (tg_pt_gp) {
1849		__target_detach_tg_pt_gp(lun, tg_pt_gp);
1850		rcu_assign_pointer(lun->lun_tg_pt_gp, NULL);
1851	}
1852	spin_unlock(&lun->lun_tg_pt_gp_lock);
1853	synchronize_rcu();
1854}
1855
1856static void target_swap_tg_pt_gp(struct se_lun *lun,
1857				 struct t10_alua_tg_pt_gp *old_tg_pt_gp,
1858				 struct t10_alua_tg_pt_gp *new_tg_pt_gp)
1859{
1860	assert_spin_locked(&lun->lun_tg_pt_gp_lock);
1861
1862	if (old_tg_pt_gp)
1863		__target_detach_tg_pt_gp(lun, old_tg_pt_gp);
1864	__target_attach_tg_pt_gp(lun, new_tg_pt_gp);
1865}
1866
1867ssize_t core_alua_show_tg_pt_gp_info(struct se_lun *lun, char *page)
1868{
1869	struct config_item *tg_pt_ci;
1870	struct t10_alua_tg_pt_gp *tg_pt_gp;
1871	ssize_t len = 0;
1872
1873	rcu_read_lock();
1874	tg_pt_gp = rcu_dereference(lun->lun_tg_pt_gp);
1875	if (tg_pt_gp) {
1876		tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
1877		len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
1878			" %hu\nTG Port Primary Access State: %s\nTG Port "
1879			"Primary Access Status: %s\nTG Port Secondary Access"
1880			" State: %s\nTG Port Secondary Access Status: %s\n",
1881			config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
1882			core_alua_dump_state(
1883				tg_pt_gp->tg_pt_gp_alua_access_state),
1884			core_alua_dump_status(
1885				tg_pt_gp->tg_pt_gp_alua_access_status),
1886			atomic_read(&lun->lun_tg_pt_secondary_offline) ?
1887			"Offline" : "None",
1888			core_alua_dump_status(lun->lun_tg_pt_secondary_stat));
1889	}
1890	rcu_read_unlock();
1891
1892	return len;
1893}
1894
1895ssize_t core_alua_store_tg_pt_gp_info(
1896	struct se_lun *lun,
1897	const char *page,
1898	size_t count)
1899{
1900	struct se_portal_group *tpg = lun->lun_tpg;
1901	/*
1902	 * rcu_dereference_raw protected by se_lun->lun_group symlink
1903	 * reference to se_device->dev_group.
1904	 */
1905	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
1906	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
1907	unsigned char buf[TG_PT_GROUP_NAME_BUF];
1908	int move = 0;
1909
1910	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
1911	    (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
1912		return -ENODEV;
1913
1914	if (count > TG_PT_GROUP_NAME_BUF) {
1915		pr_err("ALUA Target Port Group alias too large!\n");
1916		return -EINVAL;
1917	}
1918	memset(buf, 0, TG_PT_GROUP_NAME_BUF);
1919	memcpy(buf, page, count);
1920	/*
1921	 * Any ALUA target port group alias besides "NULL" means we will be
1922	 * making a new group association.
1923	 */
1924	if (strcmp(strstrip(buf), "NULL")) {
1925		/*
1926		 * core_alua_get_tg_pt_gp_by_name() will increment reference to
1927		 * struct t10_alua_tg_pt_gp.  This reference is released with
1928		 * core_alua_put_tg_pt_gp_from_name() below.
1929		 */
1930		tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(dev,
1931					strstrip(buf));
1932		if (!tg_pt_gp_new)
1933			return -ENODEV;
1934	}
1935
1936	spin_lock(&lun->lun_tg_pt_gp_lock);
1937	tg_pt_gp = rcu_dereference_check(lun->lun_tg_pt_gp,
1938				lockdep_is_held(&lun->lun_tg_pt_gp_lock));
1939	if (tg_pt_gp) {
1940		/*
1941		 * Clearing an existing tg_pt_gp association, and replacing
1942		 * with the default_tg_pt_gp.
1943		 */
1944		if (!tg_pt_gp_new) {
1945			pr_debug("Target_Core_ConfigFS: Moving"
1946				" %s/tpgt_%hu/%s from ALUA Target Port Group:"
1947				" alua/%s, ID: %hu back to"
1948				" default_tg_pt_gp\n",
1949				tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1950				tpg->se_tpg_tfo->tpg_get_tag(tpg),
1951				config_item_name(&lun->lun_group.cg_item),
1952				config_item_name(
1953					&tg_pt_gp->tg_pt_gp_group.cg_item),
1954				tg_pt_gp->tg_pt_gp_id);
1955
1956			target_swap_tg_pt_gp(lun, tg_pt_gp,
 
1957					dev->t10_alua.default_tg_pt_gp);
1958			spin_unlock(&lun->lun_tg_pt_gp_lock);
1959
1960			goto sync_rcu;
1961		}
 
1962		move = 1;
1963	}
1964
1965	target_swap_tg_pt_gp(lun, tg_pt_gp, tg_pt_gp_new);
1966	spin_unlock(&lun->lun_tg_pt_gp_lock);
1967	pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
1968		" Target Port Group: alua/%s, ID: %hu\n", (move) ?
1969		"Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
1970		tpg->se_tpg_tfo->tpg_get_tag(tpg),
1971		config_item_name(&lun->lun_group.cg_item),
1972		config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
1973		tg_pt_gp_new->tg_pt_gp_id);
1974
1975	core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
1976sync_rcu:
1977	synchronize_rcu();
1978	return count;
1979}
1980
1981ssize_t core_alua_show_access_type(
1982	struct t10_alua_tg_pt_gp *tg_pt_gp,
1983	char *page)
1984{
1985	if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA) &&
1986	    (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA))
1987		return sprintf(page, "Implicit and Explicit\n");
1988	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA)
1989		return sprintf(page, "Implicit\n");
1990	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)
1991		return sprintf(page, "Explicit\n");
1992	else
1993		return sprintf(page, "None\n");
1994}
1995
1996ssize_t core_alua_store_access_type(
1997	struct t10_alua_tg_pt_gp *tg_pt_gp,
1998	const char *page,
1999	size_t count)
2000{
2001	unsigned long tmp;
2002	int ret;
2003
2004	ret = kstrtoul(page, 0, &tmp);
2005	if (ret < 0) {
2006		pr_err("Unable to extract alua_access_type\n");
2007		return ret;
2008	}
2009	if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
2010		pr_err("Illegal value for alua_access_type:"
2011				" %lu\n", tmp);
2012		return -EINVAL;
2013	}
2014	if (tmp == 3)
2015		tg_pt_gp->tg_pt_gp_alua_access_type =
2016			TPGS_IMPLICIT_ALUA | TPGS_EXPLICIT_ALUA;
2017	else if (tmp == 2)
2018		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICIT_ALUA;
2019	else if (tmp == 1)
2020		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICIT_ALUA;
2021	else
2022		tg_pt_gp->tg_pt_gp_alua_access_type = 0;
2023
2024	return count;
2025}
2026
2027ssize_t core_alua_show_nonop_delay_msecs(
2028	struct t10_alua_tg_pt_gp *tg_pt_gp,
2029	char *page)
2030{
2031	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
2032}
2033
2034ssize_t core_alua_store_nonop_delay_msecs(
2035	struct t10_alua_tg_pt_gp *tg_pt_gp,
2036	const char *page,
2037	size_t count)
2038{
2039	unsigned long tmp;
2040	int ret;
2041
2042	ret = kstrtoul(page, 0, &tmp);
2043	if (ret < 0) {
2044		pr_err("Unable to extract nonop_delay_msecs\n");
2045		return ret;
2046	}
2047	if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
2048		pr_err("Passed nonop_delay_msecs: %lu, exceeds"
2049			" ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
2050			ALUA_MAX_NONOP_DELAY_MSECS);
2051		return -EINVAL;
2052	}
2053	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
2054
2055	return count;
2056}
2057
2058ssize_t core_alua_show_trans_delay_msecs(
2059	struct t10_alua_tg_pt_gp *tg_pt_gp,
2060	char *page)
2061{
2062	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
2063}
2064
2065ssize_t core_alua_store_trans_delay_msecs(
2066	struct t10_alua_tg_pt_gp *tg_pt_gp,
2067	const char *page,
2068	size_t count)
2069{
2070	unsigned long tmp;
2071	int ret;
2072
2073	ret = kstrtoul(page, 0, &tmp);
2074	if (ret < 0) {
2075		pr_err("Unable to extract trans_delay_msecs\n");
2076		return ret;
2077	}
2078	if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
2079		pr_err("Passed trans_delay_msecs: %lu, exceeds"
2080			" ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
2081			ALUA_MAX_TRANS_DELAY_MSECS);
2082		return -EINVAL;
2083	}
2084	tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
2085
2086	return count;
2087}
2088
2089ssize_t core_alua_show_implicit_trans_secs(
2090	struct t10_alua_tg_pt_gp *tg_pt_gp,
2091	char *page)
2092{
2093	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_implicit_trans_secs);
2094}
2095
2096ssize_t core_alua_store_implicit_trans_secs(
2097	struct t10_alua_tg_pt_gp *tg_pt_gp,
2098	const char *page,
2099	size_t count)
2100{
2101	unsigned long tmp;
2102	int ret;
2103
2104	ret = kstrtoul(page, 0, &tmp);
2105	if (ret < 0) {
2106		pr_err("Unable to extract implicit_trans_secs\n");
2107		return ret;
2108	}
2109	if (tmp > ALUA_MAX_IMPLICIT_TRANS_SECS) {
2110		pr_err("Passed implicit_trans_secs: %lu, exceeds"
2111			" ALUA_MAX_IMPLICIT_TRANS_SECS: %d\n", tmp,
2112			ALUA_MAX_IMPLICIT_TRANS_SECS);
2113		return  -EINVAL;
2114	}
2115	tg_pt_gp->tg_pt_gp_implicit_trans_secs = (int)tmp;
2116
2117	return count;
2118}
2119
2120ssize_t core_alua_show_preferred_bit(
2121	struct t10_alua_tg_pt_gp *tg_pt_gp,
2122	char *page)
2123{
2124	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
2125}
2126
2127ssize_t core_alua_store_preferred_bit(
2128	struct t10_alua_tg_pt_gp *tg_pt_gp,
2129	const char *page,
2130	size_t count)
2131{
2132	unsigned long tmp;
2133	int ret;
2134
2135	ret = kstrtoul(page, 0, &tmp);
2136	if (ret < 0) {
2137		pr_err("Unable to extract preferred ALUA value\n");
2138		return ret;
2139	}
2140	if ((tmp != 0) && (tmp != 1)) {
2141		pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
2142		return -EINVAL;
2143	}
2144	tg_pt_gp->tg_pt_gp_pref = (int)tmp;
2145
2146	return count;
2147}
2148
2149ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
2150{
2151	return sprintf(page, "%d\n",
2152		atomic_read(&lun->lun_tg_pt_secondary_offline));
2153}
2154
2155ssize_t core_alua_store_offline_bit(
2156	struct se_lun *lun,
2157	const char *page,
2158	size_t count)
2159{
2160	/*
2161	 * rcu_dereference_raw protected by se_lun->lun_group symlink
2162	 * reference to se_device->dev_group.
2163	 */
2164	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
2165	unsigned long tmp;
2166	int ret;
2167
2168	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
2169	    (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
2170		return -ENODEV;
2171
2172	ret = kstrtoul(page, 0, &tmp);
2173	if (ret < 0) {
2174		pr_err("Unable to extract alua_tg_pt_offline value\n");
2175		return ret;
2176	}
2177	if ((tmp != 0) && (tmp != 1)) {
2178		pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
2179				tmp);
2180		return -EINVAL;
2181	}
2182
2183	ret = core_alua_set_tg_pt_secondary_state(lun, 0, (int)tmp);
2184	if (ret < 0)
2185		return -EINVAL;
2186
2187	return count;
2188}
2189
2190ssize_t core_alua_show_secondary_status(
2191	struct se_lun *lun,
2192	char *page)
2193{
2194	return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_stat);
2195}
2196
2197ssize_t core_alua_store_secondary_status(
2198	struct se_lun *lun,
2199	const char *page,
2200	size_t count)
2201{
2202	unsigned long tmp;
2203	int ret;
2204
2205	ret = kstrtoul(page, 0, &tmp);
2206	if (ret < 0) {
2207		pr_err("Unable to extract alua_tg_pt_status\n");
2208		return ret;
2209	}
2210	if ((tmp != ALUA_STATUS_NONE) &&
2211	    (tmp != ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
2212	    (tmp != ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA)) {
2213		pr_err("Illegal value for alua_tg_pt_status: %lu\n",
2214				tmp);
2215		return -EINVAL;
2216	}
2217	lun->lun_tg_pt_secondary_stat = (int)tmp;
2218
2219	return count;
2220}
2221
2222ssize_t core_alua_show_secondary_write_metadata(
2223	struct se_lun *lun,
2224	char *page)
2225{
2226	return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_write_md);
2227}
2228
2229ssize_t core_alua_store_secondary_write_metadata(
2230	struct se_lun *lun,
2231	const char *page,
2232	size_t count)
2233{
2234	unsigned long tmp;
2235	int ret;
2236
2237	ret = kstrtoul(page, 0, &tmp);
2238	if (ret < 0) {
2239		pr_err("Unable to extract alua_tg_pt_write_md\n");
2240		return ret;
2241	}
2242	if ((tmp != 0) && (tmp != 1)) {
2243		pr_err("Illegal value for alua_tg_pt_write_md:"
2244				" %lu\n", tmp);
2245		return -EINVAL;
2246	}
2247	lun->lun_tg_pt_secondary_write_md = (int)tmp;
2248
2249	return count;
2250}
2251
2252int core_setup_alua(struct se_device *dev)
2253{
2254	if (!(dev->transport_flags &
2255	     TRANSPORT_FLAG_PASSTHROUGH_ALUA) &&
2256	    !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)) {
2257		struct t10_alua_lu_gp_member *lu_gp_mem;
2258
2259		/*
2260		 * Associate this struct se_device with the default ALUA
2261		 * LUN Group.
2262		 */
2263		lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
2264		if (IS_ERR(lu_gp_mem))
2265			return PTR_ERR(lu_gp_mem);
2266
2267		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
2268		__core_alua_attach_lu_gp_mem(lu_gp_mem,
2269				default_lu_gp);
2270		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
2271
2272		pr_debug("%s: Adding to default ALUA LU Group:"
2273			" core/alua/lu_gps/default_lu_gp\n",
2274			dev->transport->name);
2275	}
2276
2277	return 0;
2278}