Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2279 insertions, 0 deletions

diff --git a/drivers/target/target_core_alua.c b/drivers/target/target_core_alua.c
new file mode 100644
index 000000000..337285631
--- /dev/null
+++ b/drivers/target/target_core_alua.c
@@ -0,0 +1,2279 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*******************************************************************************
+ * Filename:  target_core_alua.c
+ *
+ * This file contains SPC-3 compliant asymmetric logical unit assigntment (ALUA)
+ *
+ * (c) Copyright 2009-2013 Datera, Inc.
+ *
+ * Nicholas A. Bellinger <nab@kernel.org>
+ *
+ ******************************************************************************/
+
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/configfs.h>
+#include <linux/delay.h>
+#include <linux/export.h>
+#include <linux/fcntl.h>
+#include <linux/file.h>
+#include <linux/fs.h>
+#include <scsi/scsi_proto.h>
+#include <asm/unaligned.h>
+
+#include <target/target_core_base.h>
+#include <target/target_core_backend.h>
+#include <target/target_core_fabric.h>
+
+#include "target_core_internal.h"
+#include "target_core_alua.h"
+#include "target_core_ua.h"
+
+static sense_reason_t core_alua_check_transition(int state, int valid,
+						 int *primary, int explicit);
+static int core_alua_set_tg_pt_secondary_state(
+		struct se_lun *lun, int explicit, int offline);
+
+static char *core_alua_dump_state(int state);
+
+static void __target_attach_tg_pt_gp(struct se_lun *lun,
+		struct t10_alua_tg_pt_gp *tg_pt_gp);
+
+static u16 alua_lu_gps_counter;
+static u32 alua_lu_gps_count;
+
+static DEFINE_SPINLOCK(lu_gps_lock);
+static LIST_HEAD(lu_gps_list);
+
+struct t10_alua_lu_gp *default_lu_gp;
+
+/*
+ * REPORT REFERRALS
+ *
+ * See sbc3r35 section 5.23
+ */
+sense_reason_t
+target_emulate_report_referrals(struct se_cmd *cmd)
+{
+	struct se_device *dev = cmd->se_dev;
+	struct t10_alua_lba_map *map;
+	struct t10_alua_lba_map_member *map_mem;
+	unsigned char *buf;
+	u32 rd_len = 0, off;
+
+	if (cmd->data_length < 4) {
+		pr_warn("REPORT REFERRALS allocation length %u too"
+			" small\n", cmd->data_length);
+		return TCM_INVALID_CDB_FIELD;
+	}
+
+	buf = transport_kmap_data_sg(cmd);
+	if (!buf)
+		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+
+	off = 4;
+	spin_lock(&dev->t10_alua.lba_map_lock);
+	if (list_empty(&dev->t10_alua.lba_map_list)) {
+		spin_unlock(&dev->t10_alua.lba_map_lock);
+		transport_kunmap_data_sg(cmd);
+
+		return TCM_UNSUPPORTED_SCSI_OPCODE;
+	}
+
+	list_for_each_entry(map, &dev->t10_alua.lba_map_list,
+			    lba_map_list) {
+		int desc_num = off + 3;
+		int pg_num;
+
+		off += 4;
+		if (cmd->data_length > off)
+			put_unaligned_be64(map->lba_map_first_lba, &buf[off]);
+		off += 8;
+		if (cmd->data_length > off)
+			put_unaligned_be64(map->lba_map_last_lba, &buf[off]);
+		off += 8;
+		rd_len += 20;
+		pg_num = 0;
+		list_for_each_entry(map_mem, &map->lba_map_mem_list,
+				    lba_map_mem_list) {
+			int alua_state = map_mem->lba_map_mem_alua_state;
+			int alua_pg_id = map_mem->lba_map_mem_alua_pg_id;
+
+			if (cmd->data_length > off)
+				buf[off] = alua_state & 0x0f;
+			off += 2;
+			if (cmd->data_length > off)
+				buf[off] = (alua_pg_id >> 8) & 0xff;
+			off++;
+			if (cmd->data_length > off)
+				buf[off] = (alua_pg_id & 0xff);
+			off++;
+			rd_len += 4;
+			pg_num++;
+		}
+		if (cmd->data_length > desc_num)
+			buf[desc_num] = pg_num;
+	}
+	spin_unlock(&dev->t10_alua.lba_map_lock);
+
+	/*
+	 * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
+	 */
+	put_unaligned_be16(rd_len, &buf[2]);
+
+	transport_kunmap_data_sg(cmd);
+
+	target_complete_cmd(cmd, SAM_STAT_GOOD);
+	return 0;
+}
+
+/*
+ * REPORT_TARGET_PORT_GROUPS
+ *
+ * See spc4r17 section 6.27
+ */
+sense_reason_t
+target_emulate_report_target_port_groups(struct se_cmd *cmd)
+{
+	struct se_device *dev = cmd->se_dev;
+	struct t10_alua_tg_pt_gp *tg_pt_gp;
+	struct se_lun *lun;
+	unsigned char *buf;
+	u32 rd_len = 0, off;
+	int ext_hdr = (cmd->t_task_cdb[1] & 0x20);
+
+	/*
+	 * Skip over RESERVED area to first Target port group descriptor
+	 * depending on the PARAMETER DATA FORMAT type..
+	 */
+	if (ext_hdr != 0)
+		off = 8;
+	else
+		off = 4;
+
+	if (cmd->data_length < off) {
+		pr_warn("REPORT TARGET PORT GROUPS allocation length %u too"
+			" small for %s header\n", cmd->data_length,
+			(ext_hdr) ? "extended" : "normal");
+		return TCM_INVALID_CDB_FIELD;
+	}
+	buf = transport_kmap_data_sg(cmd);
+	if (!buf)
+		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+
+	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
+	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
+			tg_pt_gp_list) {
+		/* Skip empty port groups */
+		if (!tg_pt_gp->tg_pt_gp_members)
+			continue;
+		/*
+		 * Check if the Target port group and Target port descriptor list
+		 * based on tg_pt_gp_members count will fit into the response payload.
+		 * Otherwise, bump rd_len to let the initiator know we have exceeded
+		 * the allocation length and the response is truncated.
+		 */
+		if ((off + 8 + (tg_pt_gp->tg_pt_gp_members * 4)) >
+		     cmd->data_length) {
+			rd_len += 8 + (tg_pt_gp->tg_pt_gp_members * 4);
+			continue;
+		}
+		/*
+		 * PREF: Preferred target port bit, determine if this
+		 * bit should be set for port group.
+		 */
+		if (tg_pt_gp->tg_pt_gp_pref)
+			buf[off] = 0x80;
+		/*
+		 * Set the ASYMMETRIC ACCESS State
+		 */
+		buf[off++] |= tg_pt_gp->tg_pt_gp_alua_access_state & 0xff;
+		/*
+		 * Set supported ASYMMETRIC ACCESS State bits
+		 */
+		buf[off++] |= tg_pt_gp->tg_pt_gp_alua_supported_states;
+		/*
+		 * TARGET PORT GROUP
+		 */
+		put_unaligned_be16(tg_pt_gp->tg_pt_gp_id, &buf[off]);
+		off += 2;
+
+		off++; /* Skip over Reserved */
+		/*
+		 * STATUS CODE
+		 */
+		buf[off++] = (tg_pt_gp->tg_pt_gp_alua_access_status & 0xff);
+		/*
+		 * Vendor Specific field
+		 */
+		buf[off++] = 0x00;
+		/*
+		 * TARGET PORT COUNT
+		 */
+		buf[off++] = (tg_pt_gp->tg_pt_gp_members & 0xff);
+		rd_len += 8;
+
+		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
+		list_for_each_entry(lun, &tg_pt_gp->tg_pt_gp_lun_list,
+				lun_tg_pt_gp_link) {
+			/*
+			 * Start Target Port descriptor format
+			 *
+			 * See spc4r17 section 6.2.7 Table 247
+			 */
+			off += 2; /* Skip over Obsolete */
+			/*
+			 * Set RELATIVE TARGET PORT IDENTIFIER
+			 */
+			put_unaligned_be16(lun->lun_tpg->tpg_rtpi, &buf[off]);
+			off += 2;
+			rd_len += 4;
+		}
+		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
+	}
+	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
+	/*
+	 * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
+	 */
+	put_unaligned_be32(rd_len, &buf[0]);
+
+	/*
+	 * Fill in the Extended header parameter data format if requested
+	 */
+	if (ext_hdr != 0) {
+		buf[4] = 0x10;
+		/*
+		 * Set the implicit transition time (in seconds) for the application
+		 * client to use as a base for it's transition timeout value.
+		 *
+		 * Use the current tg_pt_gp_mem -> tg_pt_gp membership from the LUN
+		 * this CDB was received upon to determine this value individually
+		 * for ALUA target port group.
+		 */
+		rcu_read_lock();
+		tg_pt_gp = rcu_dereference(cmd->se_lun->lun_tg_pt_gp);
+		if (tg_pt_gp)
+			buf[5] = tg_pt_gp->tg_pt_gp_implicit_trans_secs;
+		rcu_read_unlock();
+	}
+	transport_kunmap_data_sg(cmd);
+
+	target_complete_cmd_with_length(cmd, SAM_STAT_GOOD, rd_len + 4);
+	return 0;
+}
+
+/*
+ * SET_TARGET_PORT_GROUPS for explicit ALUA operation.
+ *
+ * See spc4r17 section 6.35
+ */
+sense_reason_t
+target_emulate_set_target_port_groups(struct se_cmd *cmd)
+{
+	struct se_device *dev = cmd->se_dev;
+	struct se_lun *l_lun = cmd->se_lun;
+	struct se_node_acl *nacl = cmd->se_sess->se_node_acl;
+	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *l_tg_pt_gp;
+	unsigned char *buf;
+	unsigned char *ptr;
+	sense_reason_t rc = TCM_NO_SENSE;
+	u32 len = 4; /* Skip over RESERVED area in header */
+	int alua_access_state, primary = 0, valid_states;
+	u16 tg_pt_id, rtpi;
+
+	if (cmd->data_length < 4) {
+		pr_warn("SET TARGET PORT GROUPS parameter list length %u too"
+			" small\n", cmd->data_length);
+		return TCM_INVALID_PARAMETER_LIST;
+	}
+
+	buf = transport_kmap_data_sg(cmd);
+	if (!buf)
+		return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+
+	/*
+	 * Determine if explicit ALUA via SET_TARGET_PORT_GROUPS is allowed
+	 * for the local tg_pt_gp.
+	 */
+	rcu_read_lock();
+	l_tg_pt_gp = rcu_dereference(l_lun->lun_tg_pt_gp);
+	if (!l_tg_pt_gp) {
+		rcu_read_unlock();
+		pr_err("Unable to access l_lun->tg_pt_gp\n");
+		rc = TCM_UNSUPPORTED_SCSI_OPCODE;
+		goto out;
+	}
+
+	if (!(l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)) {
+		rcu_read_unlock();
+		pr_debug("Unable to process SET_TARGET_PORT_GROUPS"
+				" while TPGS_EXPLICIT_ALUA is disabled\n");
+		rc = TCM_UNSUPPORTED_SCSI_OPCODE;
+		goto out;
+	}
+	valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
+	rcu_read_unlock();
+
+	ptr = &buf[4]; /* Skip over RESERVED area in header */
+
+	while (len < cmd->data_length) {
+		bool found = false;
+		alua_access_state = (ptr[0] & 0x0f);
+		/*
+		 * Check the received ALUA access state, and determine if
+		 * the state is a primary or secondary target port asymmetric
+		 * access state.
+		 */
+		rc = core_alua_check_transition(alua_access_state, valid_states,
+						&primary, 1);
+		if (rc) {
+			/*
+			 * If the SET TARGET PORT GROUPS attempts to establish
+			 * an invalid combination of target port asymmetric
+			 * access states or attempts to establish an
+			 * unsupported target port asymmetric access state,
+			 * then the command shall be terminated with CHECK
+			 * CONDITION status, with the sense key set to ILLEGAL
+			 * REQUEST, and the additional sense code set to INVALID
+			 * FIELD IN PARAMETER LIST.
+			 */
+			goto out;
+		}
+
+		/*
+		 * If the ASYMMETRIC ACCESS STATE field (see table 267)
+		 * specifies a primary target port asymmetric access state,
+		 * then the TARGET PORT GROUP OR TARGET PORT field specifies
+		 * a primary target port group for which the primary target
+		 * port asymmetric access state shall be changed. If the
+		 * ASYMMETRIC ACCESS STATE field specifies a secondary target
+		 * port asymmetric access state, then the TARGET PORT GROUP OR
+		 * TARGET PORT field specifies the relative target port
+		 * identifier (see 3.1.120) of the target port for which the
+		 * secondary target port asymmetric access state shall be
+		 * changed.
+		 */
+		if (primary) {
+			tg_pt_id = get_unaligned_be16(ptr + 2);
+			/*
+			 * Locate the matching target port group ID from
+			 * the global tg_pt_gp list
+			 */
+			spin_lock(&dev->t10_alua.tg_pt_gps_lock);
+			list_for_each_entry(tg_pt_gp,
+					&dev->t10_alua.tg_pt_gps_list,
+					tg_pt_gp_list) {
+				if (!tg_pt_gp->tg_pt_gp_valid_id)
+					continue;
+
+				if (tg_pt_id != tg_pt_gp->tg_pt_gp_id)
+					continue;
+
+				atomic_inc_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
+
+				spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
+
+				if (!core_alua_do_port_transition(tg_pt_gp,
+						dev, l_lun, nacl,
+						alua_access_state, 1))
+					found = true;
+
+				spin_lock(&dev->t10_alua.tg_pt_gps_lock);
+				atomic_dec_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
+				break;
+			}
+			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
+		} else {
+			struct se_lun *lun;
+
+			/*
+			 * Extract the RELATIVE TARGET PORT IDENTIFIER to identify
+			 * the Target Port in question for the incoming
+			 * SET_TARGET_PORT_GROUPS op.
+			 */
+			rtpi = get_unaligned_be16(ptr + 2);
+			/*
+			 * Locate the matching relative target port identifier
+			 * for the struct se_device storage object.
+			 */
+			spin_lock(&dev->se_port_lock);
+			list_for_each_entry(lun, &dev->dev_sep_list,
+							lun_dev_link) {
+				if (lun->lun_tpg->tpg_rtpi != rtpi)
+					continue;
+
+				// XXX: racy unlock
+				spin_unlock(&dev->se_port_lock);
+
+				if (!core_alua_set_tg_pt_secondary_state(
+						lun, 1, 1))
+					found = true;
+
+				spin_lock(&dev->se_port_lock);
+				break;
+			}
+			spin_unlock(&dev->se_port_lock);
+		}
+
+		if (!found) {
+			rc = TCM_INVALID_PARAMETER_LIST;
+			goto out;
+		}
+
+		ptr += 4;
+		len += 4;
+	}
+
+out:
+	transport_kunmap_data_sg(cmd);
+	if (!rc)
+		target_complete_cmd(cmd, SAM_STAT_GOOD);
+	return rc;
+}
+
+static inline void core_alua_state_nonoptimized(
+	struct se_cmd *cmd,
+	unsigned char *cdb,
+	int nonop_delay_msecs)
+{
+	/*
+	 * Set SCF_ALUA_NON_OPTIMIZED here, this value will be checked
+	 * later to determine if processing of this cmd needs to be
+	 * temporarily delayed for the Active/NonOptimized primary access state.
+	 */
+	cmd->se_cmd_flags |= SCF_ALUA_NON_OPTIMIZED;
+	cmd->alua_nonop_delay = nonop_delay_msecs;
+}
+
+static inline sense_reason_t core_alua_state_lba_dependent(
+	struct se_cmd *cmd,
+	u16 tg_pt_gp_id)
+{
+	struct se_device *dev = cmd->se_dev;
+	u64 segment_size, segment_mult, sectors, lba;
+
+	/* Only need to check for cdb actually containing LBAs */
+	if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB))
+		return 0;
+
+	spin_lock(&dev->t10_alua.lba_map_lock);
+	segment_size = dev->t10_alua.lba_map_segment_size;
+	segment_mult = dev->t10_alua.lba_map_segment_multiplier;
+	sectors = cmd->data_length / dev->dev_attrib.block_size;
+
+	lba = cmd->t_task_lba;
+	while (lba < cmd->t_task_lba + sectors) {
+		struct t10_alua_lba_map *cur_map = NULL, *map;
+		struct t10_alua_lba_map_member *map_mem;
+
+		list_for_each_entry(map, &dev->t10_alua.lba_map_list,
+				    lba_map_list) {
+			u64 start_lba, last_lba;
+			u64 first_lba = map->lba_map_first_lba;
+
+			if (segment_mult) {
+				u64 tmp = lba;
+				start_lba = do_div(tmp, segment_size * segment_mult);
+
+				last_lba = first_lba + segment_size - 1;
+				if (start_lba >= first_lba &&
+				    start_lba <= last_lba) {
+					lba += segment_size;
+					cur_map = map;
+					break;
+				}
+			} else {
+				last_lba = map->lba_map_last_lba;
+				if (lba >= first_lba && lba <= last_lba) {
+					lba = last_lba + 1;
+					cur_map = map;
+					break;
+				}
+			}
+		}
+		if (!cur_map) {
+			spin_unlock(&dev->t10_alua.lba_map_lock);
+			return TCM_ALUA_TG_PT_UNAVAILABLE;
+		}
+		list_for_each_entry(map_mem, &cur_map->lba_map_mem_list,
+				    lba_map_mem_list) {
+			if (map_mem->lba_map_mem_alua_pg_id != tg_pt_gp_id)
+				continue;
+			switch(map_mem->lba_map_mem_alua_state) {
+			case ALUA_ACCESS_STATE_STANDBY:
+				spin_unlock(&dev->t10_alua.lba_map_lock);
+				return TCM_ALUA_TG_PT_STANDBY;
+			case ALUA_ACCESS_STATE_UNAVAILABLE:
+				spin_unlock(&dev->t10_alua.lba_map_lock);
+				return TCM_ALUA_TG_PT_UNAVAILABLE;
+			default:
+				break;
+			}
+		}
+	}
+	spin_unlock(&dev->t10_alua.lba_map_lock);
+	return 0;
+}
+
+static inline sense_reason_t core_alua_state_standby(
+	struct se_cmd *cmd,
+	unsigned char *cdb)
+{
+	/*
+	 * Allowed CDBs for ALUA_ACCESS_STATE_STANDBY as defined by
+	 * spc4r17 section 5.9.2.4.4
+	 */
+	switch (cdb[0]) {
+	case INQUIRY:
+	case LOG_SELECT:
+	case LOG_SENSE:
+	case MODE_SELECT:
+	case MODE_SENSE:
+	case REPORT_LUNS:
+	case RECEIVE_DIAGNOSTIC:
+	case SEND_DIAGNOSTIC:
+	case READ_CAPACITY:
+		return 0;
+	case SERVICE_ACTION_IN_16:
+		switch (cdb[1] & 0x1f) {
+		case SAI_READ_CAPACITY_16:
+			return 0;
+		default:
+			return TCM_ALUA_TG_PT_STANDBY;
+		}
+	case MAINTENANCE_IN:
+		switch (cdb[1] & 0x1f) {
+		case MI_REPORT_TARGET_PGS:
+			return 0;
+		default:
+			return TCM_ALUA_TG_PT_STANDBY;
+		}
+	case MAINTENANCE_OUT:
+		switch (cdb[1]) {
+		case MO_SET_TARGET_PGS:
+			return 0;
+		default:
+			return TCM_ALUA_TG_PT_STANDBY;
+		}
+	case REQUEST_SENSE:
+	case PERSISTENT_RESERVE_IN:
+	case PERSISTENT_RESERVE_OUT:
+	case READ_BUFFER:
+	case WRITE_BUFFER:
+		return 0;
+	default:
+		return TCM_ALUA_TG_PT_STANDBY;
+	}
+
+	return 0;
+}
+
+static inline sense_reason_t core_alua_state_unavailable(
+	struct se_cmd *cmd,
+	unsigned char *cdb)
+{
+	/*
+	 * Allowed CDBs for ALUA_ACCESS_STATE_UNAVAILABLE as defined by
+	 * spc4r17 section 5.9.2.4.5
+	 */
+	switch (cdb[0]) {
+	case INQUIRY:
+	case REPORT_LUNS:
+		return 0;
+	case MAINTENANCE_IN:
+		switch (cdb[1] & 0x1f) {
+		case MI_REPORT_TARGET_PGS:
+			return 0;
+		default:
+			return TCM_ALUA_TG_PT_UNAVAILABLE;
+		}
+	case MAINTENANCE_OUT:
+		switch (cdb[1]) {
+		case MO_SET_TARGET_PGS:
+			return 0;
+		default:
+			return TCM_ALUA_TG_PT_UNAVAILABLE;
+		}
+	case REQUEST_SENSE:
+	case READ_BUFFER:
+	case WRITE_BUFFER:
+		return 0;
+	default:
+		return TCM_ALUA_TG_PT_UNAVAILABLE;
+	}
+
+	return 0;
+}
+
+static inline sense_reason_t core_alua_state_transition(
+	struct se_cmd *cmd,
+	unsigned char *cdb)
+{
+	/*
+	 * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITION as defined by
+	 * spc4r17 section 5.9.2.5
+	 */
+	switch (cdb[0]) {
+	case INQUIRY:
+	case REPORT_LUNS:
+		return 0;
+	case MAINTENANCE_IN:
+		switch (cdb[1] & 0x1f) {
+		case MI_REPORT_TARGET_PGS:
+			return 0;
+		default:
+			return TCM_ALUA_STATE_TRANSITION;
+		}
+	case REQUEST_SENSE:
+	case READ_BUFFER:
+	case WRITE_BUFFER:
+		return 0;
+	default:
+		return TCM_ALUA_STATE_TRANSITION;
+	}
+
+	return 0;
+}
+
+/*
+ * return 1: Is used to signal LUN not accessible, and check condition/not ready
+ * return 0: Used to signal success
+ * return -1: Used to signal failure, and invalid cdb field
+ */
+sense_reason_t
+target_alua_state_check(struct se_cmd *cmd)
+{
+	struct se_device *dev = cmd->se_dev;
+	unsigned char *cdb = cmd->t_task_cdb;
+	struct se_lun *lun = cmd->se_lun;
+	struct t10_alua_tg_pt_gp *tg_pt_gp;
+	int out_alua_state, nonop_delay_msecs;
+	u16 tg_pt_gp_id;
+	sense_reason_t rc = TCM_NO_SENSE;
+
+	if (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)
+		return 0;
+	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
+		return 0;
+
+	/*
+	 * First, check for a struct se_port specific secondary ALUA target port
+	 * access state: OFFLINE
+	 */
+	if (atomic_read(&lun->lun_tg_pt_secondary_offline)) {
+		pr_debug("ALUA: Got secondary offline status for local"
+				" target port\n");
+		return TCM_ALUA_OFFLINE;
+	}
+	rcu_read_lock();
+	tg_pt_gp = rcu_dereference(lun->lun_tg_pt_gp);
+	if (!tg_pt_gp) {
+		rcu_read_unlock();
+		return 0;
+	}
+
+	out_alua_state = tg_pt_gp->tg_pt_gp_alua_access_state;
+	nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
+	tg_pt_gp_id = tg_pt_gp->tg_pt_gp_id;
+	rcu_read_unlock();
+	/*
+	 * Process ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED in a separate conditional
+	 * statement so the compiler knows explicitly to check this case first.
+	 * For the Optimized ALUA access state case, we want to process the
+	 * incoming fabric cmd ASAP..
+	 */
+	if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED)
+		return 0;
+
+	switch (out_alua_state) {
+	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
+		core_alua_state_nonoptimized(cmd, cdb, nonop_delay_msecs);
+		break;
+	case ALUA_ACCESS_STATE_STANDBY:
+		rc = core_alua_state_standby(cmd, cdb);
+		break;
+	case ALUA_ACCESS_STATE_UNAVAILABLE:
+		rc = core_alua_state_unavailable(cmd, cdb);
+		break;
+	case ALUA_ACCESS_STATE_TRANSITION:
+		rc = core_alua_state_transition(cmd, cdb);
+		break;
+	case ALUA_ACCESS_STATE_LBA_DEPENDENT:
+		rc = core_alua_state_lba_dependent(cmd, tg_pt_gp_id);
+		break;
+	/*
+	 * OFFLINE is a secondary ALUA target port group access state, that is
+	 * handled above with struct se_lun->lun_tg_pt_secondary_offline=1
+	 */
+	case ALUA_ACCESS_STATE_OFFLINE:
+	default:
+		pr_err("Unknown ALUA access state: 0x%02x\n",
+				out_alua_state);
+		rc = TCM_INVALID_CDB_FIELD;
+	}
+
+	if (rc && rc != TCM_INVALID_CDB_FIELD) {
+		pr_debug("[%s]: ALUA TG Port not available, "
+			"SenseKey: NOT_READY, ASC/rc: 0x04/%d\n",
+			cmd->se_tfo->fabric_name, rc);
+	}
+
+	return rc;
+}
+
+/*
+ * Check implicit and explicit ALUA state change request.
+ */
+static sense_reason_t
+core_alua_check_transition(int state, int valid, int *primary, int explicit)
+{
+	/*
+	 * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
+	 * defined as primary target port asymmetric access states.
+	 */
+	switch (state) {
+	case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
+		if (!(valid & ALUA_AO_SUP))
+			goto not_supported;
+		*primary = 1;
+		break;
+	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
+		if (!(valid & ALUA_AN_SUP))
+			goto not_supported;
+		*primary = 1;
+		break;
+	case ALUA_ACCESS_STATE_STANDBY:
+		if (!(valid & ALUA_S_SUP))
+			goto not_supported;
+		*primary = 1;
+		break;
+	case ALUA_ACCESS_STATE_UNAVAILABLE:
+		if (!(valid & ALUA_U_SUP))
+			goto not_supported;
+		*primary = 1;
+		break;
+	case ALUA_ACCESS_STATE_LBA_DEPENDENT:
+		if (!(valid & ALUA_LBD_SUP))
+			goto not_supported;
+		*primary = 1;
+		break;
+	case ALUA_ACCESS_STATE_OFFLINE:
+		/*
+		 * OFFLINE state is defined as a secondary target port
+		 * asymmetric access state.
+		 */
+		if (!(valid & ALUA_O_SUP))
+			goto not_supported;
+		*primary = 0;
+		break;
+	case ALUA_ACCESS_STATE_TRANSITION:
+		if (!(valid & ALUA_T_SUP) || explicit)
+			/*
+			 * Transitioning is set internally and by tcmu daemon,
+			 * and cannot be selected through a STPG.
+			 */
+			goto not_supported;
+		*primary = 0;
+		break;
+	default:
+		pr_err("Unknown ALUA access state: 0x%02x\n", state);
+		return TCM_INVALID_PARAMETER_LIST;
+	}
+
+	return 0;
+
+not_supported:
+	pr_err("ALUA access state %s not supported",
+	       core_alua_dump_state(state));
+	return TCM_INVALID_PARAMETER_LIST;
+}
+
+static char *core_alua_dump_state(int state)
+{
+	switch (state) {
+	case ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED:
+		return "Active/Optimized";
+	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
+		return "Active/NonOptimized";
+	case ALUA_ACCESS_STATE_LBA_DEPENDENT:
+		return "LBA Dependent";
+	case ALUA_ACCESS_STATE_STANDBY:
+		return "Standby";
+	case ALUA_ACCESS_STATE_UNAVAILABLE:
+		return "Unavailable";
+	case ALUA_ACCESS_STATE_OFFLINE:
+		return "Offline";
+	case ALUA_ACCESS_STATE_TRANSITION:
+		return "Transitioning";
+	default:
+		return "Unknown";
+	}
+
+	return NULL;
+}
+
+char *core_alua_dump_status(int status)
+{
+	switch (status) {
+	case ALUA_STATUS_NONE:
+		return "None";
+	case ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG:
+		return "Altered by Explicit STPG";
+	case ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA:
+		return "Altered by Implicit ALUA";
+	default:
+		return "Unknown";
+	}
+
+	return NULL;
+}
+
+/*
+ * Used by fabric modules to determine when we need to delay processing
+ * for the Active/NonOptimized paths..
+ */
+int core_alua_check_nonop_delay(
+	struct se_cmd *cmd)
+{
+	if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
+		return 0;
+	/*
+	 * The ALUA Active/NonOptimized access state delay can be disabled
+	 * in via configfs with a value of zero
+	 */
+	if (!cmd->alua_nonop_delay)
+		return 0;
+	/*
+	 * struct se_cmd->alua_nonop_delay gets set by a target port group
+	 * defined interval in core_alua_state_nonoptimized()
+	 */
+	msleep_interruptible(cmd->alua_nonop_delay);
+	return 0;
+}
+EXPORT_SYMBOL(core_alua_check_nonop_delay);
+
+static int core_alua_write_tpg_metadata(
+	const char *path,
+	unsigned char *md_buf,
+	u32 md_buf_len)
+{
+	struct file *file = filp_open(path, O_RDWR | O_CREAT | O_TRUNC, 0600);
+	loff_t pos = 0;
+	int ret;
+
+	if (IS_ERR(file)) {
+		pr_err("filp_open(%s) for ALUA metadata failed\n", path);
+		return -ENODEV;
+	}
+	ret = kernel_write(file, md_buf, md_buf_len, &pos);
+	if (ret < 0)
+		pr_err("Error writing ALUA metadata file: %s\n", path);
+	fput(file);
+	return (ret < 0) ? -EIO : 0;
+}
+
+static int core_alua_update_tpg_primary_metadata(
+	struct t10_alua_tg_pt_gp *tg_pt_gp)
+{
+	unsigned char *md_buf;
+	struct t10_wwn *wwn = &tg_pt_gp->tg_pt_gp_dev->t10_wwn;
+	char *path;
+	int len, rc;
+
+	lockdep_assert_held(&tg_pt_gp->tg_pt_gp_transition_mutex);
+
+	md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
+	if (!md_buf) {
+		pr_err("Unable to allocate buf for ALUA metadata\n");
+		return -ENOMEM;
+	}
+
+	len = snprintf(md_buf, ALUA_MD_BUF_LEN,
+			"tg_pt_gp_id=%hu\n"
+			"alua_access_state=0x%02x\n"
+			"alua_access_status=0x%02x\n",
+			tg_pt_gp->tg_pt_gp_id,
+			tg_pt_gp->tg_pt_gp_alua_access_state,
+			tg_pt_gp->tg_pt_gp_alua_access_status);
+
+	rc = -ENOMEM;
+	path = kasprintf(GFP_KERNEL, "%s/alua/tpgs_%s/%s", db_root,
+			&wwn->unit_serial[0],
+			config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
+	if (path) {
+		rc = core_alua_write_tpg_metadata(path, md_buf, len);
+		kfree(path);
+	}
+	kfree(md_buf);
+	return rc;
+}
+
+static void core_alua_queue_state_change_ua(struct t10_alua_tg_pt_gp *tg_pt_gp)
+{
+	struct se_dev_entry *se_deve;
+	struct se_lun *lun;
+	struct se_lun_acl *lacl;
+
+	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
+	list_for_each_entry(lun, &tg_pt_gp->tg_pt_gp_lun_list,
+				lun_tg_pt_gp_link) {
+		/*
+		 * After an implicit target port asymmetric access state
+		 * change, a device server shall establish a unit attention
+		 * condition for the initiator port associated with every I_T
+		 * nexus with the additional sense code set to ASYMMETRIC
+		 * ACCESS STATE CHANGED.
+		 *
+		 * After an explicit target port asymmetric access state
+		 * change, a device server shall establish a unit attention
+		 * condition with the additional sense code set to ASYMMETRIC
+		 * ACCESS STATE CHANGED for the initiator port associated with
+		 * every I_T nexus other than the I_T nexus on which the SET
+		 * TARGET PORT GROUPS command
+		 */
+		if (!percpu_ref_tryget_live(&lun->lun_ref))
+			continue;
+		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
+
+		spin_lock(&lun->lun_deve_lock);
+		list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link) {
+			lacl = se_deve->se_lun_acl;
+
+			/*
+			 * spc4r37 p.242:
+			 * After an explicit target port asymmetric access
+			 * state change, a device server shall establish a
+			 * unit attention condition with the additional sense
+			 * code set to ASYMMETRIC ACCESS STATE CHANGED for
+			 * the initiator port associated with every I_T nexus
+			 * other than the I_T nexus on which the SET TARGET
+			 * PORT GROUPS command was received.
+			 */
+			if ((tg_pt_gp->tg_pt_gp_alua_access_status ==
+			     ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
+			   (tg_pt_gp->tg_pt_gp_alua_lun != NULL) &&
+			    (tg_pt_gp->tg_pt_gp_alua_lun == lun))
+				continue;
+
+			/*
+			 * se_deve->se_lun_acl pointer may be NULL for a
+			 * entry created without explicit Node+MappedLUN ACLs
+			 */
+			if (lacl && (tg_pt_gp->tg_pt_gp_alua_nacl != NULL) &&
+			    (tg_pt_gp->tg_pt_gp_alua_nacl == lacl->se_lun_nacl))
+				continue;
+
+			core_scsi3_ua_allocate(se_deve, 0x2A,
+				ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
+		}
+		spin_unlock(&lun->lun_deve_lock);
+
+		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
+		percpu_ref_put(&lun->lun_ref);
+	}
+	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
+}
+
+static int core_alua_do_transition_tg_pt(
+	struct t10_alua_tg_pt_gp *tg_pt_gp,
+	int new_state,
+	int explicit)
+{
+	int prev_state;
+
+	mutex_lock(&tg_pt_gp->tg_pt_gp_transition_mutex);
+	/* Nothing to be done here */
+	if (tg_pt_gp->tg_pt_gp_alua_access_state == new_state) {
+		mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
+		return 0;
+	}
+
+	if (explicit && new_state == ALUA_ACCESS_STATE_TRANSITION) {
+		mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
+		return -EAGAIN;
+	}
+
+	/*
+	 * Save the old primary ALUA access state, and set the current state
+	 * to ALUA_ACCESS_STATE_TRANSITION.
+	 */
+	prev_state = tg_pt_gp->tg_pt_gp_alua_access_state;
+	tg_pt_gp->tg_pt_gp_alua_access_state = ALUA_ACCESS_STATE_TRANSITION;
+	tg_pt_gp->tg_pt_gp_alua_access_status = (explicit) ?
+				ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
+				ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
+
+	core_alua_queue_state_change_ua(tg_pt_gp);
+
+	if (new_state == ALUA_ACCESS_STATE_TRANSITION) {
+		mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
+		return 0;
+	}
+
+	/*
+	 * Check for the optional ALUA primary state transition delay
+	 */
+	if (tg_pt_gp->tg_pt_gp_trans_delay_msecs != 0)
+		msleep_interruptible(tg_pt_gp->tg_pt_gp_trans_delay_msecs);
+
+	/*
+	 * Set the current primary ALUA access state to the requested new state
+	 */
+	tg_pt_gp->tg_pt_gp_alua_access_state = new_state;
+
+	/*
+	 * Update the ALUA metadata buf that has been allocated in
+	 * core_alua_do_port_transition(), this metadata will be written
+	 * to struct file.
+	 *
+	 * Note that there is the case where we do not want to update the
+	 * metadata when the saved metadata is being parsed in userspace
+	 * when setting the existing port access state and access status.
+	 *
+	 * Also note that the failure to write out the ALUA metadata to
+	 * struct file does NOT affect the actual ALUA transition.
+	 */
+	if (tg_pt_gp->tg_pt_gp_write_metadata) {
+		core_alua_update_tpg_primary_metadata(tg_pt_gp);
+	}
+
+	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
+		" from primary access state %s to %s\n", (explicit) ? "explicit" :
+		"implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
+		tg_pt_gp->tg_pt_gp_id,
+		core_alua_dump_state(prev_state),
+		core_alua_dump_state(new_state));
+
+	core_alua_queue_state_change_ua(tg_pt_gp);
+
+	mutex_unlock(&tg_pt_gp->tg_pt_gp_transition_mutex);
+	return 0;
+}
+
+int core_alua_do_port_transition(
+	struct t10_alua_tg_pt_gp *l_tg_pt_gp,
+	struct se_device *l_dev,
+	struct se_lun *l_lun,
+	struct se_node_acl *l_nacl,
+	int new_state,
+	int explicit)
+{
+	struct se_device *dev;
+	struct t10_alua_lu_gp *lu_gp;
+	struct t10_alua_lu_gp_member *lu_gp_mem, *local_lu_gp_mem;
+	struct t10_alua_tg_pt_gp *tg_pt_gp;
+	int primary, valid_states, rc = 0;
+
+	if (l_dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA)
+		return -ENODEV;
+
+	valid_states = l_tg_pt_gp->tg_pt_gp_alua_supported_states;
+	if (core_alua_check_transition(new_state, valid_states, &primary,
+				       explicit) != 0)
+		return -EINVAL;
+
+	local_lu_gp_mem = l_dev->dev_alua_lu_gp_mem;
+	spin_lock(&local_lu_gp_mem->lu_gp_mem_lock);
+	lu_gp = local_lu_gp_mem->lu_gp;
+	atomic_inc(&lu_gp->lu_gp_ref_cnt);
+	spin_unlock(&local_lu_gp_mem->lu_gp_mem_lock);
+	/*
+	 * For storage objects that are members of the 'default_lu_gp',
+	 * we only do transition on the passed *l_tp_pt_gp, and not
+	 * on all of the matching target port groups IDs in default_lu_gp.
+	 */
+	if (!lu_gp->lu_gp_id) {
+		/*
+		 * core_alua_do_transition_tg_pt() will always return
+		 * success.
+		 */
+		l_tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
+		l_tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
+		rc = core_alua_do_transition_tg_pt(l_tg_pt_gp,
+						   new_state, explicit);
+		atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
+		return rc;
+	}
+	/*
+	 * For all other LU groups aside from 'default_lu_gp', walk all of
+	 * the associated storage objects looking for a matching target port
+	 * group ID from the local target port group.
+	 */
+	spin_lock(&lu_gp->lu_gp_lock);
+	list_for_each_entry(lu_gp_mem, &lu_gp->lu_gp_mem_list,
+				lu_gp_mem_list) {
+
+		dev = lu_gp_mem->lu_gp_mem_dev;
+		atomic_inc_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
+		spin_unlock(&lu_gp->lu_gp_lock);
+
+		spin_lock(&dev->t10_alua.tg_pt_gps_lock);
+		list_for_each_entry(tg_pt_gp,
+				&dev->t10_alua.tg_pt_gps_list,
+				tg_pt_gp_list) {
+
+			if (!tg_pt_gp->tg_pt_gp_valid_id)
+				continue;
+			/*
+			 * If the target behavior port asymmetric access state
+			 * is changed for any target port group accessible via
+			 * a logical unit within a LU group, the target port
+			 * behavior group asymmetric access states for the same
+			 * target port group accessible via other logical units
+			 * in that LU group will also change.
+			 */
+			if (l_tg_pt_gp->tg_pt_gp_id != tg_pt_gp->tg_pt_gp_id)
+				continue;
+
+			if (l_tg_pt_gp == tg_pt_gp) {
+				tg_pt_gp->tg_pt_gp_alua_lun = l_lun;
+				tg_pt_gp->tg_pt_gp_alua_nacl = l_nacl;
+			} else {
+				tg_pt_gp->tg_pt_gp_alua_lun = NULL;
+				tg_pt_gp->tg_pt_gp_alua_nacl = NULL;
+			}
+			atomic_inc_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
+			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
+			/*
+			 * core_alua_do_transition_tg_pt() will always return
+			 * success.
+			 */
+			rc = core_alua_do_transition_tg_pt(tg_pt_gp,
+					new_state, explicit);
+
+			spin_lock(&dev->t10_alua.tg_pt_gps_lock);
+			atomic_dec_mb(&tg_pt_gp->tg_pt_gp_ref_cnt);
+			if (rc)
+				break;
+		}
+		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
+
+		spin_lock(&lu_gp->lu_gp_lock);
+		atomic_dec_mb(&lu_gp_mem->lu_gp_mem_ref_cnt);
+	}
+	spin_unlock(&lu_gp->lu_gp_lock);
+
+	if (!rc) {
+		pr_debug("Successfully processed LU Group: %s all ALUA TG PT"
+			 " Group IDs: %hu %s transition to primary state: %s\n",
+			 config_item_name(&lu_gp->lu_gp_group.cg_item),
+			 l_tg_pt_gp->tg_pt_gp_id,
+			 (explicit) ? "explicit" : "implicit",
+			 core_alua_dump_state(new_state));
+	}
+
+	atomic_dec_mb(&lu_gp->lu_gp_ref_cnt);
+	return rc;
+}
+
+static int core_alua_update_tpg_secondary_metadata(struct se_lun *lun)
+{
+	struct se_portal_group *se_tpg = lun->lun_tpg;
+	unsigned char *md_buf;
+	char *path;
+	int len, rc;
+
+	mutex_lock(&lun->lun_tg_pt_md_mutex);
+
+	md_buf = kzalloc(ALUA_MD_BUF_LEN, GFP_KERNEL);
+	if (!md_buf) {
+		pr_err("Unable to allocate buf for ALUA metadata\n");
+		rc = -ENOMEM;
+		goto out_unlock;
+	}
+
+	len = snprintf(md_buf, ALUA_MD_BUF_LEN, "alua_tg_pt_offline=%d\n"
+			"alua_tg_pt_status=0x%02x\n",
+			atomic_read(&lun->lun_tg_pt_secondary_offline),
+			lun->lun_tg_pt_secondary_stat);
+
+	if (se_tpg->se_tpg_tfo->tpg_get_tag != NULL) {
+		path = kasprintf(GFP_KERNEL, "%s/alua/%s/%s+%hu/lun_%llu",
+				db_root, se_tpg->se_tpg_tfo->fabric_name,
+				se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg),
+				se_tpg->se_tpg_tfo->tpg_get_tag(se_tpg),
+				lun->unpacked_lun);
+	} else {
+		path = kasprintf(GFP_KERNEL, "%s/alua/%s/%s/lun_%llu",
+				db_root, se_tpg->se_tpg_tfo->fabric_name,
+				se_tpg->se_tpg_tfo->tpg_get_wwn(se_tpg),
+				lun->unpacked_lun);
+	}
+	if (!path) {
+		rc = -ENOMEM;
+		goto out_free;
+	}
+
+	rc = core_alua_write_tpg_metadata(path, md_buf, len);
+	kfree(path);
+out_free:
+	kfree(md_buf);
+out_unlock:
+	mutex_unlock(&lun->lun_tg_pt_md_mutex);
+	return rc;
+}
+
+static int core_alua_set_tg_pt_secondary_state(
+	struct se_lun *lun,
+	int explicit,
+	int offline)
+{
+	struct t10_alua_tg_pt_gp *tg_pt_gp;
+	int trans_delay_msecs;
+
+	rcu_read_lock();
+	tg_pt_gp = rcu_dereference(lun->lun_tg_pt_gp);
+	if (!tg_pt_gp) {
+		rcu_read_unlock();
+		pr_err("Unable to complete secondary state"
+				" transition\n");
+		return -EINVAL;
+	}
+	trans_delay_msecs = tg_pt_gp->tg_pt_gp_trans_delay_msecs;
+	/*
+	 * Set the secondary ALUA target port access state to OFFLINE
+	 * or release the previously secondary state for struct se_lun
+	 */
+	if (offline)
+		atomic_set(&lun->lun_tg_pt_secondary_offline, 1);
+	else
+		atomic_set(&lun->lun_tg_pt_secondary_offline, 0);
+
+	lun->lun_tg_pt_secondary_stat = (explicit) ?
+			ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG :
+			ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA;
+
+	pr_debug("Successful %s ALUA transition TG PT Group: %s ID: %hu"
+		" to secondary access state: %s\n", (explicit) ? "explicit" :
+		"implicit", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
+		tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
+
+	rcu_read_unlock();
+	/*
+	 * Do the optional transition delay after we set the secondary
+	 * ALUA access state.
+	 */
+	if (trans_delay_msecs != 0)
+		msleep_interruptible(trans_delay_msecs);
+	/*
+	 * See if we need to update the ALUA fabric port metadata for
+	 * secondary state and status
+	 */
+	if (lun->lun_tg_pt_secondary_write_md)
+		core_alua_update_tpg_secondary_metadata(lun);
+
+	return 0;
+}
+
+struct t10_alua_lba_map *
+core_alua_allocate_lba_map(struct list_head *list,
+			   u64 first_lba, u64 last_lba)
+{
+	struct t10_alua_lba_map *lba_map;
+
+	lba_map = kmem_cache_zalloc(t10_alua_lba_map_cache, GFP_KERNEL);
+	if (!lba_map) {
+		pr_err("Unable to allocate struct t10_alua_lba_map\n");
+		return ERR_PTR(-ENOMEM);
+	}
+	INIT_LIST_HEAD(&lba_map->lba_map_mem_list);
+	lba_map->lba_map_first_lba = first_lba;
+	lba_map->lba_map_last_lba = last_lba;
+
+	list_add_tail(&lba_map->lba_map_list, list);
+	return lba_map;
+}
+
+int
+core_alua_allocate_lba_map_mem(struct t10_alua_lba_map *lba_map,
+			       int pg_id, int state)
+{
+	struct t10_alua_lba_map_member *lba_map_mem;
+
+	list_for_each_entry(lba_map_mem, &lba_map->lba_map_mem_list,
+			    lba_map_mem_list) {
+		if (lba_map_mem->lba_map_mem_alua_pg_id == pg_id) {
+			pr_err("Duplicate pg_id %d in lba_map\n", pg_id);
+			return -EINVAL;
+		}
+	}
+
+	lba_map_mem = kmem_cache_zalloc(t10_alua_lba_map_mem_cache, GFP_KERNEL);
+	if (!lba_map_mem) {
+		pr_err("Unable to allocate struct t10_alua_lba_map_mem\n");
+		return -ENOMEM;
+	}
+	lba_map_mem->lba_map_mem_alua_state = state;
+	lba_map_mem->lba_map_mem_alua_pg_id = pg_id;
+
+	list_add_tail(&lba_map_mem->lba_map_mem_list,
+		      &lba_map->lba_map_mem_list);
+	return 0;
+}
+
+void
+core_alua_free_lba_map(struct list_head *lba_list)
+{
+	struct t10_alua_lba_map *lba_map, *lba_map_tmp;
+	struct t10_alua_lba_map_member *lba_map_mem, *lba_map_mem_tmp;
+
+	list_for_each_entry_safe(lba_map, lba_map_tmp, lba_list,
+				 lba_map_list) {
+		list_for_each_entry_safe(lba_map_mem, lba_map_mem_tmp,
+					 &lba_map->lba_map_mem_list,
+					 lba_map_mem_list) {
+			list_del(&lba_map_mem->lba_map_mem_list);
+			kmem_cache_free(t10_alua_lba_map_mem_cache,
+					lba_map_mem);
+		}
+		list_del(&lba_map->lba_map_list);
+		kmem_cache_free(t10_alua_lba_map_cache, lba_map);
+	}
+}
+
+void
+core_alua_set_lba_map(struct se_device *dev, struct list_head *lba_map_list,
+		      int segment_size, int segment_mult)
+{
+	struct list_head old_lba_map_list;
+	struct t10_alua_tg_pt_gp *tg_pt_gp;
+	int activate = 0, supported;
+
+	INIT_LIST_HEAD(&old_lba_map_list);
+	spin_lock(&dev->t10_alua.lba_map_lock);
+	dev->t10_alua.lba_map_segment_size = segment_size;
+	dev->t10_alua.lba_map_segment_multiplier = segment_mult;
+	list_splice_init(&dev->t10_alua.lba_map_list, &old_lba_map_list);
+	if (lba_map_list) {
+		list_splice_init(lba_map_list, &dev->t10_alua.lba_map_list);
+		activate = 1;
+	}
+	spin_unlock(&dev->t10_alua.lba_map_lock);
+	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
+	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
+			    tg_pt_gp_list) {
+
+		if (!tg_pt_gp->tg_pt_gp_valid_id)
+			continue;
+		supported = tg_pt_gp->tg_pt_gp_alua_supported_states;
+		if (activate)
+			supported |= ALUA_LBD_SUP;
+		else
+			supported &= ~ALUA_LBD_SUP;
+		tg_pt_gp->tg_pt_gp_alua_supported_states = supported;
+	}
+	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
+	core_alua_free_lba_map(&old_lba_map_list);
+}
+
+struct t10_alua_lu_gp *
+core_alua_allocate_lu_gp(const char *name, int def_group)
+{
+	struct t10_alua_lu_gp *lu_gp;
+
+	lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
+	if (!lu_gp) {
+		pr_err("Unable to allocate struct t10_alua_lu_gp\n");
+		return ERR_PTR(-ENOMEM);
+	}
+	INIT_LIST_HEAD(&lu_gp->lu_gp_node);
+	INIT_LIST_HEAD(&lu_gp->lu_gp_mem_list);
+	spin_lock_init(&lu_gp->lu_gp_lock);
+	atomic_set(&lu_gp->lu_gp_ref_cnt, 0);
+
+	if (def_group) {
+		lu_gp->lu_gp_id = alua_lu_gps_counter++;
+		lu_gp->lu_gp_valid_id = 1;
+		alua_lu_gps_count++;
+	}
+
+	return lu_gp;
+}
+
+int core_alua_set_lu_gp_id(struct t10_alua_lu_gp *lu_gp, u16 lu_gp_id)
+{
+	struct t10_alua_lu_gp *lu_gp_tmp;
+	u16 lu_gp_id_tmp;
+	/*
+	 * The lu_gp->lu_gp_id may only be set once..
+	 */
+	if (lu_gp->lu_gp_valid_id) {
+		pr_warn("ALUA LU Group already has a valid ID,"
+			" ignoring request\n");
+		return -EINVAL;
+	}
+
+	spin_lock(&lu_gps_lock);
+	if (alua_lu_gps_count == 0x0000ffff) {
+		pr_err("Maximum ALUA alua_lu_gps_count:"
+				" 0x0000ffff reached\n");
+		spin_unlock(&lu_gps_lock);
+		kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
+		return -ENOSPC;
+	}
+again:
+	lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
+				alua_lu_gps_counter++;
+
+	list_for_each_entry(lu_gp_tmp, &lu_gps_list, lu_gp_node) {
+		if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
+			if (!lu_gp_id)
+				goto again;
+
+			pr_warn("ALUA Logical Unit Group ID: %hu"
+				" already exists, ignoring request\n",
+				lu_gp_id);
+			spin_unlock(&lu_gps_lock);
+			return -EINVAL;
+		}
+	}
+
+	lu_gp->lu_gp_id = lu_gp_id_tmp;
+	lu_gp->lu_gp_valid_id = 1;
+	list_add_tail(&lu_gp->lu_gp_node, &lu_gps_list);
+	alua_lu_gps_count++;
+	spin_unlock(&lu_gps_lock);
+
+	return 0;
+}
+
+static struct t10_alua_lu_gp_member *
+core_alua_allocate_lu_gp_mem(struct se_device *dev)
+{
+	struct t10_alua_lu_gp_member *lu_gp_mem;
+
+	lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
+	if (!lu_gp_mem) {
+		pr_err("Unable to allocate struct t10_alua_lu_gp_member\n");
+		return ERR_PTR(-ENOMEM);
+	}
+	INIT_LIST_HEAD(&lu_gp_mem->lu_gp_mem_list);
+	spin_lock_init(&lu_gp_mem->lu_gp_mem_lock);
+	atomic_set(&lu_gp_mem->lu_gp_mem_ref_cnt, 0);
+
+	lu_gp_mem->lu_gp_mem_dev = dev;
+	dev->dev_alua_lu_gp_mem = lu_gp_mem;
+
+	return lu_gp_mem;
+}
+
+void core_alua_free_lu_gp(struct t10_alua_lu_gp *lu_gp)
+{
+	struct t10_alua_lu_gp_member *lu_gp_mem, *lu_gp_mem_tmp;
+	/*
+	 * Once we have reached this point, config_item_put() has
+	 * already been called from target_core_alua_drop_lu_gp().
+	 *
+	 * Here, we remove the *lu_gp from the global list so that
+	 * no associations can be made while we are releasing
+	 * struct t10_alua_lu_gp.
+	 */
+	spin_lock(&lu_gps_lock);
+	list_del(&lu_gp->lu_gp_node);
+	alua_lu_gps_count--;
+	spin_unlock(&lu_gps_lock);
+	/*
+	 * Allow struct t10_alua_lu_gp * referenced by core_alua_get_lu_gp_by_name()
+	 * in target_core_configfs.c:target_core_store_alua_lu_gp() to be
+	 * released with core_alua_put_lu_gp_from_name()
+	 */
+	while (atomic_read(&lu_gp->lu_gp_ref_cnt))
+		cpu_relax();
+	/*
+	 * Release reference to struct t10_alua_lu_gp * from all associated
+	 * struct se_device.
+	 */
+	spin_lock(&lu_gp->lu_gp_lock);
+	list_for_each_entry_safe(lu_gp_mem, lu_gp_mem_tmp,
+				&lu_gp->lu_gp_mem_list, lu_gp_mem_list) {
+		if (lu_gp_mem->lu_gp_assoc) {
+			list_del(&lu_gp_mem->lu_gp_mem_list);
+			lu_gp->lu_gp_members--;
+			lu_gp_mem->lu_gp_assoc = 0;
+		}
+		spin_unlock(&lu_gp->lu_gp_lock);
+		/*
+		 *
+		 * lu_gp_mem is associated with a single
+		 * struct se_device->dev_alua_lu_gp_mem, and is released when
+		 * struct se_device is released via core_alua_free_lu_gp_mem().
+		 *
+		 * If the passed lu_gp does NOT match the default_lu_gp, assume
+		 * we want to re-associate a given lu_gp_mem with default_lu_gp.
+		 */
+		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
+		if (lu_gp != default_lu_gp)
+			__core_alua_attach_lu_gp_mem(lu_gp_mem,
+					default_lu_gp);
+		else
+			lu_gp_mem->lu_gp = NULL;
+		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
+
+		spin_lock(&lu_gp->lu_gp_lock);
+	}
+	spin_unlock(&lu_gp->lu_gp_lock);
+
+	kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
+}
+
+void core_alua_free_lu_gp_mem(struct se_device *dev)
+{
+	struct t10_alua_lu_gp *lu_gp;
+	struct t10_alua_lu_gp_member *lu_gp_mem;
+
+	lu_gp_mem = dev->dev_alua_lu_gp_mem;
+	if (!lu_gp_mem)
+		return;
+
+	while (atomic_read(&lu_gp_mem->lu_gp_mem_ref_cnt))
+		cpu_relax();
+
+	spin_lock(&lu_gp_mem->lu_gp_mem_lock);
+	lu_gp = lu_gp_mem->lu_gp;
+	if (lu_gp) {
+		spin_lock(&lu_gp->lu_gp_lock);
+		if (lu_gp_mem->lu_gp_assoc) {
+			list_del(&lu_gp_mem->lu_gp_mem_list);
+			lu_gp->lu_gp_members--;
+			lu_gp_mem->lu_gp_assoc = 0;
+		}
+		spin_unlock(&lu_gp->lu_gp_lock);
+		lu_gp_mem->lu_gp = NULL;
+	}
+	spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
+
+	kmem_cache_free(t10_alua_lu_gp_mem_cache, lu_gp_mem);
+}
+
+struct t10_alua_lu_gp *core_alua_get_lu_gp_by_name(const char *name)
+{
+	struct t10_alua_lu_gp *lu_gp;
+	struct config_item *ci;
+
+	spin_lock(&lu_gps_lock);
+	list_for_each_entry(lu_gp, &lu_gps_list, lu_gp_node) {
+		if (!lu_gp->lu_gp_valid_id)
+			continue;
+		ci = &lu_gp->lu_gp_group.cg_item;
+		if (!strcmp(config_item_name(ci), name)) {
+			atomic_inc(&lu_gp->lu_gp_ref_cnt);
+			spin_unlock(&lu_gps_lock);
+			return lu_gp;
+		}
+	}
+	spin_unlock(&lu_gps_lock);
+
+	return NULL;
+}
+
+void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp *lu_gp)
+{
+	spin_lock(&lu_gps_lock);
+	atomic_dec(&lu_gp->lu_gp_ref_cnt);
+	spin_unlock(&lu_gps_lock);
+}
+
+/*
+ * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
+ */
+void __core_alua_attach_lu_gp_mem(
+	struct t10_alua_lu_gp_member *lu_gp_mem,
+	struct t10_alua_lu_gp *lu_gp)
+{
+	spin_lock(&lu_gp->lu_gp_lock);
+	lu_gp_mem->lu_gp = lu_gp;
+	lu_gp_mem->lu_gp_assoc = 1;
+	list_add_tail(&lu_gp_mem->lu_gp_mem_list, &lu_gp->lu_gp_mem_list);
+	lu_gp->lu_gp_members++;
+	spin_unlock(&lu_gp->lu_gp_lock);
+}
+
+/*
+ * Called with struct t10_alua_lu_gp_member->lu_gp_mem_lock
+ */
+void __core_alua_drop_lu_gp_mem(
+	struct t10_alua_lu_gp_member *lu_gp_mem,
+	struct t10_alua_lu_gp *lu_gp)
+{
+	spin_lock(&lu_gp->lu_gp_lock);
+	list_del(&lu_gp_mem->lu_gp_mem_list);
+	lu_gp_mem->lu_gp = NULL;
+	lu_gp_mem->lu_gp_assoc = 0;
+	lu_gp->lu_gp_members--;
+	spin_unlock(&lu_gp->lu_gp_lock);
+}
+
+struct t10_alua_tg_pt_gp *core_alua_allocate_tg_pt_gp(struct se_device *dev,
+		const char *name, int def_group)
+{
+	struct t10_alua_tg_pt_gp *tg_pt_gp;
+
+	tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
+	if (!tg_pt_gp) {
+		pr_err("Unable to allocate struct t10_alua_tg_pt_gp\n");
+		return NULL;
+	}
+	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
+	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_lun_list);
+	mutex_init(&tg_pt_gp->tg_pt_gp_transition_mutex);
+	spin_lock_init(&tg_pt_gp->tg_pt_gp_lock);
+	atomic_set(&tg_pt_gp->tg_pt_gp_ref_cnt, 0);
+	tg_pt_gp->tg_pt_gp_dev = dev;
+	tg_pt_gp->tg_pt_gp_alua_access_state =
+			ALUA_ACCESS_STATE_ACTIVE_OPTIMIZED;
+	/*
+	 * Enable both explicit and implicit ALUA support by default
+	 */
+	tg_pt_gp->tg_pt_gp_alua_access_type =
+			TPGS_EXPLICIT_ALUA | TPGS_IMPLICIT_ALUA;
+	/*
+	 * Set the default Active/NonOptimized Delay in milliseconds
+	 */
+	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = ALUA_DEFAULT_NONOP_DELAY_MSECS;
+	tg_pt_gp->tg_pt_gp_trans_delay_msecs = ALUA_DEFAULT_TRANS_DELAY_MSECS;
+	tg_pt_gp->tg_pt_gp_implicit_trans_secs = ALUA_DEFAULT_IMPLICIT_TRANS_SECS;
+
+	/*
+	 * Enable all supported states
+	 */
+	tg_pt_gp->tg_pt_gp_alua_supported_states =
+	    ALUA_T_SUP | ALUA_O_SUP |
+	    ALUA_U_SUP | ALUA_S_SUP | ALUA_AN_SUP | ALUA_AO_SUP;
+
+	if (def_group) {
+		spin_lock(&dev->t10_alua.tg_pt_gps_lock);
+		tg_pt_gp->tg_pt_gp_id =
+				dev->t10_alua.alua_tg_pt_gps_counter++;
+		tg_pt_gp->tg_pt_gp_valid_id = 1;
+		dev->t10_alua.alua_tg_pt_gps_count++;
+		list_add_tail(&tg_pt_gp->tg_pt_gp_list,
+			      &dev->t10_alua.tg_pt_gps_list);
+		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
+	}
+
+	return tg_pt_gp;
+}
+
+int core_alua_set_tg_pt_gp_id(
+	struct t10_alua_tg_pt_gp *tg_pt_gp,
+	u16 tg_pt_gp_id)
+{
+	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
+	struct t10_alua_tg_pt_gp *tg_pt_gp_tmp;
+	u16 tg_pt_gp_id_tmp;
+
+	/*
+	 * The tg_pt_gp->tg_pt_gp_id may only be set once..
+	 */
+	if (tg_pt_gp->tg_pt_gp_valid_id) {
+		pr_warn("ALUA TG PT Group already has a valid ID,"
+			" ignoring request\n");
+		return -EINVAL;
+	}
+
+	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
+	if (dev->t10_alua.alua_tg_pt_gps_count == 0x0000ffff) {
+		pr_err("Maximum ALUA alua_tg_pt_gps_count:"
+			" 0x0000ffff reached\n");
+		spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
+		return -ENOSPC;
+	}
+again:
+	tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
+			dev->t10_alua.alua_tg_pt_gps_counter++;
+
+	list_for_each_entry(tg_pt_gp_tmp, &dev->t10_alua.tg_pt_gps_list,
+			tg_pt_gp_list) {
+		if (tg_pt_gp_tmp->tg_pt_gp_id == tg_pt_gp_id_tmp) {
+			if (!tg_pt_gp_id)
+				goto again;
+
+			pr_err("ALUA Target Port Group ID: %hu already"
+				" exists, ignoring request\n", tg_pt_gp_id);
+			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
+			return -EINVAL;
+		}
+	}
+
+	tg_pt_gp->tg_pt_gp_id = tg_pt_gp_id_tmp;
+	tg_pt_gp->tg_pt_gp_valid_id = 1;
+	list_add_tail(&tg_pt_gp->tg_pt_gp_list,
+			&dev->t10_alua.tg_pt_gps_list);
+	dev->t10_alua.alua_tg_pt_gps_count++;
+	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
+
+	return 0;
+}
+
+void core_alua_free_tg_pt_gp(
+	struct t10_alua_tg_pt_gp *tg_pt_gp)
+{
+	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
+	struct se_lun *lun, *next;
+
+	/*
+	 * Once we have reached this point, config_item_put() has already
+	 * been called from target_core_alua_drop_tg_pt_gp().
+	 *
+	 * Here we remove *tg_pt_gp from the global list so that
+	 * no associations *OR* explicit ALUA via SET_TARGET_PORT_GROUPS
+	 * can be made while we are releasing struct t10_alua_tg_pt_gp.
+	 */
+	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
+	if (tg_pt_gp->tg_pt_gp_valid_id) {
+		list_del(&tg_pt_gp->tg_pt_gp_list);
+		dev->t10_alua.alua_tg_pt_gps_count--;
+	}
+	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
+
+	/*
+	 * Allow a struct t10_alua_tg_pt_gp_member * referenced by
+	 * core_alua_get_tg_pt_gp_by_name() in
+	 * target_core_configfs.c:target_core_store_alua_tg_pt_gp()
+	 * to be released with core_alua_put_tg_pt_gp_from_name().
+	 */
+	while (atomic_read(&tg_pt_gp->tg_pt_gp_ref_cnt))
+		cpu_relax();
+
+	/*
+	 * Release reference to struct t10_alua_tg_pt_gp from all associated
+	 * struct se_port.
+	 */
+	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
+	list_for_each_entry_safe(lun, next,
+			&tg_pt_gp->tg_pt_gp_lun_list, lun_tg_pt_gp_link) {
+		list_del_init(&lun->lun_tg_pt_gp_link);
+		tg_pt_gp->tg_pt_gp_members--;
+
+		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
+		/*
+		 * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
+		 * assume we want to re-associate a given tg_pt_gp_mem with
+		 * default_tg_pt_gp.
+		 */
+		spin_lock(&lun->lun_tg_pt_gp_lock);
+		if (tg_pt_gp != dev->t10_alua.default_tg_pt_gp) {
+			__target_attach_tg_pt_gp(lun,
+					dev->t10_alua.default_tg_pt_gp);
+		} else
+			rcu_assign_pointer(lun->lun_tg_pt_gp, NULL);
+		spin_unlock(&lun->lun_tg_pt_gp_lock);
+
+		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
+	}
+	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
+
+	synchronize_rcu();
+	kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
+}
+
+static struct t10_alua_tg_pt_gp *core_alua_get_tg_pt_gp_by_name(
+		struct se_device *dev, const char *name)
+{
+	struct t10_alua_tg_pt_gp *tg_pt_gp;
+	struct config_item *ci;
+
+	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
+	list_for_each_entry(tg_pt_gp, &dev->t10_alua.tg_pt_gps_list,
+			tg_pt_gp_list) {
+		if (!tg_pt_gp->tg_pt_gp_valid_id)
+			continue;
+		ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
+		if (!strcmp(config_item_name(ci), name)) {
+			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
+			spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
+			return tg_pt_gp;
+		}
+	}
+	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
+
+	return NULL;
+}
+
+static void core_alua_put_tg_pt_gp_from_name(
+	struct t10_alua_tg_pt_gp *tg_pt_gp)
+{
+	struct se_device *dev = tg_pt_gp->tg_pt_gp_dev;
+
+	spin_lock(&dev->t10_alua.tg_pt_gps_lock);
+	atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
+	spin_unlock(&dev->t10_alua.tg_pt_gps_lock);
+}
+
+static void __target_attach_tg_pt_gp(struct se_lun *lun,
+		struct t10_alua_tg_pt_gp *tg_pt_gp)
+{
+	struct se_dev_entry *se_deve;
+
+	assert_spin_locked(&lun->lun_tg_pt_gp_lock);
+
+	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
+	rcu_assign_pointer(lun->lun_tg_pt_gp, tg_pt_gp);
+	list_add_tail(&lun->lun_tg_pt_gp_link, &tg_pt_gp->tg_pt_gp_lun_list);
+	tg_pt_gp->tg_pt_gp_members++;
+	spin_lock(&lun->lun_deve_lock);
+	list_for_each_entry(se_deve, &lun->lun_deve_list, lun_link)
+		core_scsi3_ua_allocate(se_deve, 0x3f,
+				       ASCQ_3FH_INQUIRY_DATA_HAS_CHANGED);
+	spin_unlock(&lun->lun_deve_lock);
+	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
+}
+
+void target_attach_tg_pt_gp(struct se_lun *lun,
+		struct t10_alua_tg_pt_gp *tg_pt_gp)
+{
+	spin_lock(&lun->lun_tg_pt_gp_lock);
+	__target_attach_tg_pt_gp(lun, tg_pt_gp);
+	spin_unlock(&lun->lun_tg_pt_gp_lock);
+	synchronize_rcu();
+}
+
+static void __target_detach_tg_pt_gp(struct se_lun *lun,
+		struct t10_alua_tg_pt_gp *tg_pt_gp)
+{
+	assert_spin_locked(&lun->lun_tg_pt_gp_lock);
+
+	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
+	list_del_init(&lun->lun_tg_pt_gp_link);
+	tg_pt_gp->tg_pt_gp_members--;
+	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
+}
+
+void target_detach_tg_pt_gp(struct se_lun *lun)
+{
+	struct t10_alua_tg_pt_gp *tg_pt_gp;
+
+	spin_lock(&lun->lun_tg_pt_gp_lock);
+	tg_pt_gp = rcu_dereference_check(lun->lun_tg_pt_gp,
+				lockdep_is_held(&lun->lun_tg_pt_gp_lock));
+	if (tg_pt_gp) {
+		__target_detach_tg_pt_gp(lun, tg_pt_gp);
+		rcu_assign_pointer(lun->lun_tg_pt_gp, NULL);
+	}
+	spin_unlock(&lun->lun_tg_pt_gp_lock);
+	synchronize_rcu();
+}
+
+static void target_swap_tg_pt_gp(struct se_lun *lun,
+				 struct t10_alua_tg_pt_gp *old_tg_pt_gp,
+				 struct t10_alua_tg_pt_gp *new_tg_pt_gp)
+{
+	assert_spin_locked(&lun->lun_tg_pt_gp_lock);
+
+	if (old_tg_pt_gp)
+		__target_detach_tg_pt_gp(lun, old_tg_pt_gp);
+	__target_attach_tg_pt_gp(lun, new_tg_pt_gp);
+}
+
+ssize_t core_alua_show_tg_pt_gp_info(struct se_lun *lun, char *page)
+{
+	struct config_item *tg_pt_ci;
+	struct t10_alua_tg_pt_gp *tg_pt_gp;
+	ssize_t len = 0;
+
+	rcu_read_lock();
+	tg_pt_gp = rcu_dereference(lun->lun_tg_pt_gp);
+	if (tg_pt_gp) {
+		tg_pt_ci = &tg_pt_gp->tg_pt_gp_group.cg_item;
+		len += sprintf(page, "TG Port Alias: %s\nTG Port Group ID:"
+			" %hu\nTG Port Primary Access State: %s\nTG Port "
+			"Primary Access Status: %s\nTG Port Secondary Access"
+			" State: %s\nTG Port Secondary Access Status: %s\n",
+			config_item_name(tg_pt_ci), tg_pt_gp->tg_pt_gp_id,
+			core_alua_dump_state(
+				tg_pt_gp->tg_pt_gp_alua_access_state),
+			core_alua_dump_status(
+				tg_pt_gp->tg_pt_gp_alua_access_status),
+			atomic_read(&lun->lun_tg_pt_secondary_offline) ?
+			"Offline" : "None",
+			core_alua_dump_status(lun->lun_tg_pt_secondary_stat));
+	}
+	rcu_read_unlock();
+
+	return len;
+}
+
+ssize_t core_alua_store_tg_pt_gp_info(
+	struct se_lun *lun,
+	const char *page,
+	size_t count)
+{
+	struct se_portal_group *tpg = lun->lun_tpg;
+	/*
+	 * rcu_dereference_raw protected by se_lun->lun_group symlink
+	 * reference to se_device->dev_group.
+	 */
+	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
+	struct t10_alua_tg_pt_gp *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
+	unsigned char buf[TG_PT_GROUP_NAME_BUF];
+	int move = 0;
+
+	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
+	    (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
+		return -ENODEV;
+
+	if (count > TG_PT_GROUP_NAME_BUF) {
+		pr_err("ALUA Target Port Group alias too large!\n");
+		return -EINVAL;
+	}
+	memset(buf, 0, TG_PT_GROUP_NAME_BUF);
+	memcpy(buf, page, count);
+	/*
+	 * Any ALUA target port group alias besides "NULL" means we will be
+	 * making a new group association.
+	 */
+	if (strcmp(strstrip(buf), "NULL")) {
+		/*
+		 * core_alua_get_tg_pt_gp_by_name() will increment reference to
+		 * struct t10_alua_tg_pt_gp.  This reference is released with
+		 * core_alua_put_tg_pt_gp_from_name() below.
+		 */
+		tg_pt_gp_new = core_alua_get_tg_pt_gp_by_name(dev,
+					strstrip(buf));
+		if (!tg_pt_gp_new)
+			return -ENODEV;
+	}
+
+	spin_lock(&lun->lun_tg_pt_gp_lock);
+	tg_pt_gp = rcu_dereference_check(lun->lun_tg_pt_gp,
+				lockdep_is_held(&lun->lun_tg_pt_gp_lock));
+	if (tg_pt_gp) {
+		/*
+		 * Clearing an existing tg_pt_gp association, and replacing
+		 * with the default_tg_pt_gp.
+		 */
+		if (!tg_pt_gp_new) {
+			pr_debug("Target_Core_ConfigFS: Moving"
+				" %s/tpgt_%hu/%s from ALUA Target Port Group:"
+				" alua/%s, ID: %hu back to"
+				" default_tg_pt_gp\n",
+				tpg->se_tpg_tfo->tpg_get_wwn(tpg),
+				tpg->se_tpg_tfo->tpg_get_tag(tpg),
+				config_item_name(&lun->lun_group.cg_item),
+				config_item_name(
+					&tg_pt_gp->tg_pt_gp_group.cg_item),
+				tg_pt_gp->tg_pt_gp_id);
+
+			target_swap_tg_pt_gp(lun, tg_pt_gp,
+					dev->t10_alua.default_tg_pt_gp);
+			spin_unlock(&lun->lun_tg_pt_gp_lock);
+
+			goto sync_rcu;
+		}
+		move = 1;
+	}
+
+	target_swap_tg_pt_gp(lun, tg_pt_gp, tg_pt_gp_new);
+	spin_unlock(&lun->lun_tg_pt_gp_lock);
+	pr_debug("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA"
+		" Target Port Group: alua/%s, ID: %hu\n", (move) ?
+		"Moving" : "Adding", tpg->se_tpg_tfo->tpg_get_wwn(tpg),
+		tpg->se_tpg_tfo->tpg_get_tag(tpg),
+		config_item_name(&lun->lun_group.cg_item),
+		config_item_name(&tg_pt_gp_new->tg_pt_gp_group.cg_item),
+		tg_pt_gp_new->tg_pt_gp_id);
+
+	core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
+sync_rcu:
+	synchronize_rcu();
+	return count;
+}
+
+ssize_t core_alua_show_access_type(
+	struct t10_alua_tg_pt_gp *tg_pt_gp,
+	char *page)
+{
+	if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA) &&
+	    (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA))
+		return sprintf(page, "Implicit and Explicit\n");
+	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICIT_ALUA)
+		return sprintf(page, "Implicit\n");
+	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICIT_ALUA)
+		return sprintf(page, "Explicit\n");
+	else
+		return sprintf(page, "None\n");
+}
+
+ssize_t core_alua_store_access_type(
+	struct t10_alua_tg_pt_gp *tg_pt_gp,
+	const char *page,
+	size_t count)
+{
+	unsigned long tmp;
+	int ret;
+
+	ret = kstrtoul(page, 0, &tmp);
+	if (ret < 0) {
+		pr_err("Unable to extract alua_access_type\n");
+		return ret;
+	}
+	if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
+		pr_err("Illegal value for alua_access_type:"
+				" %lu\n", tmp);
+		return -EINVAL;
+	}
+	if (tmp == 3)
+		tg_pt_gp->tg_pt_gp_alua_access_type =
+			TPGS_IMPLICIT_ALUA | TPGS_EXPLICIT_ALUA;
+	else if (tmp == 2)
+		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICIT_ALUA;
+	else if (tmp == 1)
+		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICIT_ALUA;
+	else
+		tg_pt_gp->tg_pt_gp_alua_access_type = 0;
+
+	return count;
+}
+
+ssize_t core_alua_show_nonop_delay_msecs(
+	struct t10_alua_tg_pt_gp *tg_pt_gp,
+	char *page)
+{
+	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_nonop_delay_msecs);
+}
+
+ssize_t core_alua_store_nonop_delay_msecs(
+	struct t10_alua_tg_pt_gp *tg_pt_gp,
+	const char *page,
+	size_t count)
+{
+	unsigned long tmp;
+	int ret;
+
+	ret = kstrtoul(page, 0, &tmp);
+	if (ret < 0) {
+		pr_err("Unable to extract nonop_delay_msecs\n");
+		return ret;
+	}
+	if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
+		pr_err("Passed nonop_delay_msecs: %lu, exceeds"
+			" ALUA_MAX_NONOP_DELAY_MSECS: %d\n", tmp,
+			ALUA_MAX_NONOP_DELAY_MSECS);
+		return -EINVAL;
+	}
+	tg_pt_gp->tg_pt_gp_nonop_delay_msecs = (int)tmp;
+
+	return count;
+}
+
+ssize_t core_alua_show_trans_delay_msecs(
+	struct t10_alua_tg_pt_gp *tg_pt_gp,
+	char *page)
+{
+	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_trans_delay_msecs);
+}
+
+ssize_t core_alua_store_trans_delay_msecs(
+	struct t10_alua_tg_pt_gp *tg_pt_gp,
+	const char *page,
+	size_t count)
+{
+	unsigned long tmp;
+	int ret;
+
+	ret = kstrtoul(page, 0, &tmp);
+	if (ret < 0) {
+		pr_err("Unable to extract trans_delay_msecs\n");
+		return ret;
+	}
+	if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
+		pr_err("Passed trans_delay_msecs: %lu, exceeds"
+			" ALUA_MAX_TRANS_DELAY_MSECS: %d\n", tmp,
+			ALUA_MAX_TRANS_DELAY_MSECS);
+		return -EINVAL;
+	}
+	tg_pt_gp->tg_pt_gp_trans_delay_msecs = (int)tmp;
+
+	return count;
+}
+
+ssize_t core_alua_show_implicit_trans_secs(
+	struct t10_alua_tg_pt_gp *tg_pt_gp,
+	char *page)
+{
+	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_implicit_trans_secs);
+}
+
+ssize_t core_alua_store_implicit_trans_secs(
+	struct t10_alua_tg_pt_gp *tg_pt_gp,
+	const char *page,
+	size_t count)
+{
+	unsigned long tmp;
+	int ret;
+
+	ret = kstrtoul(page, 0, &tmp);
+	if (ret < 0) {
+		pr_err("Unable to extract implicit_trans_secs\n");
+		return ret;
+	}
+	if (tmp > ALUA_MAX_IMPLICIT_TRANS_SECS) {
+		pr_err("Passed implicit_trans_secs: %lu, exceeds"
+			" ALUA_MAX_IMPLICIT_TRANS_SECS: %d\n", tmp,
+			ALUA_MAX_IMPLICIT_TRANS_SECS);
+		return  -EINVAL;
+	}
+	tg_pt_gp->tg_pt_gp_implicit_trans_secs = (int)tmp;
+
+	return count;
+}
+
+ssize_t core_alua_show_preferred_bit(
+	struct t10_alua_tg_pt_gp *tg_pt_gp,
+	char *page)
+{
+	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
+}
+
+ssize_t core_alua_store_preferred_bit(
+	struct t10_alua_tg_pt_gp *tg_pt_gp,
+	const char *page,
+	size_t count)
+{
+	unsigned long tmp;
+	int ret;
+
+	ret = kstrtoul(page, 0, &tmp);
+	if (ret < 0) {
+		pr_err("Unable to extract preferred ALUA value\n");
+		return ret;
+	}
+	if ((tmp != 0) && (tmp != 1)) {
+		pr_err("Illegal value for preferred ALUA: %lu\n", tmp);
+		return -EINVAL;
+	}
+	tg_pt_gp->tg_pt_gp_pref = (int)tmp;
+
+	return count;
+}
+
+ssize_t core_alua_show_offline_bit(struct se_lun *lun, char *page)
+{
+	return sprintf(page, "%d\n",
+		atomic_read(&lun->lun_tg_pt_secondary_offline));
+}
+
+ssize_t core_alua_store_offline_bit(
+	struct se_lun *lun,
+	const char *page,
+	size_t count)
+{
+	/*
+	 * rcu_dereference_raw protected by se_lun->lun_group symlink
+	 * reference to se_device->dev_group.
+	 */
+	struct se_device *dev = rcu_dereference_raw(lun->lun_se_dev);
+	unsigned long tmp;
+	int ret;
+
+	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH_ALUA ||
+	    (dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE))
+		return -ENODEV;
+
+	ret = kstrtoul(page, 0, &tmp);
+	if (ret < 0) {
+		pr_err("Unable to extract alua_tg_pt_offline value\n");
+		return ret;
+	}
+	if ((tmp != 0) && (tmp != 1)) {
+		pr_err("Illegal value for alua_tg_pt_offline: %lu\n",
+				tmp);
+		return -EINVAL;
+	}
+
+	ret = core_alua_set_tg_pt_secondary_state(lun, 0, (int)tmp);
+	if (ret < 0)
+		return -EINVAL;
+
+	return count;
+}
+
+ssize_t core_alua_show_secondary_status(
+	struct se_lun *lun,
+	char *page)
+{
+	return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_stat);
+}
+
+ssize_t core_alua_store_secondary_status(
+	struct se_lun *lun,
+	const char *page,
+	size_t count)
+{
+	unsigned long tmp;
+	int ret;
+
+	ret = kstrtoul(page, 0, &tmp);
+	if (ret < 0) {
+		pr_err("Unable to extract alua_tg_pt_status\n");
+		return ret;
+	}
+	if ((tmp != ALUA_STATUS_NONE) &&
+	    (tmp != ALUA_STATUS_ALTERED_BY_EXPLICIT_STPG) &&
+	    (tmp != ALUA_STATUS_ALTERED_BY_IMPLICIT_ALUA)) {
+		pr_err("Illegal value for alua_tg_pt_status: %lu\n",
+				tmp);
+		return -EINVAL;
+	}
+	lun->lun_tg_pt_secondary_stat = (int)tmp;
+
+	return count;
+}
+
+ssize_t core_alua_show_secondary_write_metadata(
+	struct se_lun *lun,
+	char *page)
+{
+	return sprintf(page, "%d\n", lun->lun_tg_pt_secondary_write_md);
+}
+
+ssize_t core_alua_store_secondary_write_metadata(
+	struct se_lun *lun,
+	const char *page,
+	size_t count)
+{
+	unsigned long tmp;
+	int ret;
+
+	ret = kstrtoul(page, 0, &tmp);
+	if (ret < 0) {
+		pr_err("Unable to extract alua_tg_pt_write_md\n");
+		return ret;
+	}
+	if ((tmp != 0) && (tmp != 1)) {
+		pr_err("Illegal value for alua_tg_pt_write_md:"
+				" %lu\n", tmp);
+		return -EINVAL;
+	}
+	lun->lun_tg_pt_secondary_write_md = (int)tmp;
+
+	return count;
+}
+
+int core_setup_alua(struct se_device *dev)
+{
+	if (!(dev->transport_flags &
+	     TRANSPORT_FLAG_PASSTHROUGH_ALUA) &&
+	    !(dev->se_hba->hba_flags & HBA_FLAGS_INTERNAL_USE)) {
+		struct t10_alua_lu_gp_member *lu_gp_mem;
+
+		/*
+		 * Associate this struct se_device with the default ALUA
+		 * LUN Group.
+		 */
+		lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
+		if (IS_ERR(lu_gp_mem))
+			return PTR_ERR(lu_gp_mem);
+
+		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
+		__core_alua_attach_lu_gp_mem(lu_gp_mem,
+				default_lu_gp);
+		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
+
+		pr_debug("%s: Adding to default ALUA LU Group:"
+			" core/alua/lu_gps/default_lu_gp\n",
+			dev->transport->name);
+	}
+
+	return 0;
+}