[RFC PATCH 1/19] Target_Core_Mod Asymmetric Logical UnitAssignment (ALUA) support

[Nicholas A. Bellinger]

[RFC PATCH 1/19] Target_Core_Mod Asymmetric Logical Unit Assignment (ALUA) support

This patch adds explict (via SET_TARGET_PORT_GROUPS) implict (via ConfigFS) ALUA support
supporting all primary and secondary access states.  This also also supports both the 
Logical Unit and Target Port Groups abstractions

It also include support for writing ALUA metadata to /var/target/alua for saving Primary/Secondary
access states and status across target power loss, reboots, etc.

Please see the following for more information:

http://www.linux-iscsi.org/index.php/ALUA

Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx>
diff --git a/drivers/target/target_core_alua.c b/drivers/target/target_core_alua.c
new file mode 100644
index 0000000..7685d46
--- /dev/null
+++ b/drivers/target/target_core_alua.c
@@ -0,0 +1,1983 @@
+/*******************************************************************************
+ * Filename:  target_core_alua.c
+ *
+ * This file contains SPC-3 compliant asymmetric logical unit assigntment (ALUA)
+ *
+ * Copyright (c) 2009 Rising Tide, Inc.
+ * Copyright (c) 2009 Linux-iSCSI.org
+ *
+ * Nicholas A. Bellinger <nab@xxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ ******************************************************************************/
+
+#define TARGET_CORE_ALUA_C
+
+#include <linux/version.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/configfs.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+
+#include <target/target_core_base.h>
+#include <target/target_core_device.h>
+#include <target/target_core_hba.h>
+#include <target/target_core_transport.h>
+#include <target/target_core_alua.h>
+#include <target/target_core_transport_plugin.h>
+#include <target/target_core_ua.h>
+#include <target/target_core_fabric_ops.h>
+#include <target/target_core_configfs.h>
+
+#undef TARGET_CORE_ALUA_C
+
+/*
+ * REPORT_TARGET_PORT_GROUPS
+ *
+ * See spc4r17 section 6.27
+ */
+int core_scsi3_emulate_report_target_port_groups(se_cmd_t *cmd)
+{
+	se_subsystem_dev_t *su_dev = SE_DEV(cmd)->se_sub_dev;
+	se_port_t *port;
+	t10_alua_tg_pt_gp_t *tg_pt_gp;
+	t10_alua_tg_pt_gp_member_t *tg_pt_gp_mem;
+	unsigned char *buf = (unsigned char *)T_TASK(cmd)->t_task_buf;
+	u32 rd_len = 0, off = 4;
+
+	spin_lock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+	list_for_each_entry(tg_pt_gp, &T10_ALUA(su_dev)->tg_pt_gps_list,
+			tg_pt_gp_list) {
+		/*
+		 * 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++] |= (atomic_read(
+			&tg_pt_gp->tg_pt_gp_alua_access_state) & 0xff);
+		/*
+		 * Set supported ASYMMETRIC ACCESS State bits
+		 */
+		buf[off] = 0x80; /* T_SUP */
+		buf[off] |= 0x40; /* O_SUP */
+		buf[off] |= 0x8; /* U_SUP */
+		buf[off] |= 0x4; /* S_SUP */
+		buf[off] |= 0x2; /* AN_SUP */
+		buf[off++] |= 0x1; /* AO_SUP */
+		/*
+		 * TARGET PORT GROUP
+		 */
+		buf[off++] = ((tg_pt_gp->tg_pt_gp_id >> 8) & 0xff);
+		buf[off++] = (tg_pt_gp->tg_pt_gp_id & 0xff);
+
+		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(tg_pt_gp_mem, &tg_pt_gp->tg_pt_gp_mem_list,
+				tg_pt_gp_mem_list) {
+			port = tg_pt_gp_mem->tg_pt;
+			/*
+			 * Start Target Port descriptor format
+			 *
+			 * See spc4r17 section 6.2.7 Table 247
+			 */
+			off += 2; /* Skip over Obsolete */
+			/*
+			 * Set RELATIVE TARGET PORT IDENTIFIER
+			 */
+			buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
+			buf[off++] = (port->sep_rtpi & 0xff);
+			rd_len += 4;
+		}
+		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
+	}
+	spin_unlock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+	/*
+	 * Set the RETURN DATA LENGTH set in the header of the DataIN Payload
+	 */
+	buf[0] = ((rd_len >> 24) & 0xff);
+	buf[1] = ((rd_len >> 16) & 0xff);
+	buf[2] = ((rd_len >> 8) & 0xff);
+	buf[3] = (rd_len & 0xff);
+
+	return 0;
+}
+
+/*
+ * SET_TARGET_PORT_GROUPS for explict ALUA operation.
+ *
+ * See spc4r17 section 6.35
+ */
+int core_scsi3_emulate_set_target_port_groups(se_cmd_t *cmd)
+{
+	se_device_t *dev = SE_DEV(cmd);
+	se_subsystem_dev_t *su_dev = SE_DEV(cmd)->se_sub_dev;
+	se_port_t *port, *l_port = SE_LUN(cmd)->lun_sep;
+	se_node_acl_t *nacl = SE_SESS(cmd)->se_node_acl;
+	t10_alua_tg_pt_gp_t *tg_pt_gp = NULL, *l_tg_pt_gp;
+	t10_alua_tg_pt_gp_member_t *tg_pt_gp_mem, *l_tg_pt_gp_mem;
+	unsigned char *buf = (unsigned char *)T_TASK(cmd)->t_task_buf;
+	unsigned char *ptr = &buf[4]; /* Skip over RESERVED area in header */
+	u32 len = 4; /* Skip over RESERVED area in header */
+	int alua_access_state, primary = 0, ret;
+	u16 tg_pt_id, rtpi;
+
+	if (!(l_port))
+		return -1;
+	/*
+	 * Determine if explict ALUA via SET_TARGET_PORT_GROUPS is allowed
+	 * for the local tg_pt_gp.
+	 */
+	l_tg_pt_gp_mem = l_port->sep_alua_tg_pt_gp_mem;
+	if (!(l_tg_pt_gp_mem)) {
+		printk(KERN_ERR "Unable to access *l_tg_pt_gp_mem\n");
+		return PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
+	}
+	spin_lock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
+	l_tg_pt_gp = l_tg_pt_gp_mem->tg_pt_gp;
+	if (!(l_tg_pt_gp)) {
+		spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
+		printk(KERN_ERR "Unable to access *l_l_tg_pt_gp\n");
+		return PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
+	}
+	ret = (l_tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA);
+	spin_unlock(&l_tg_pt_gp_mem->tg_pt_gp_mem_lock);
+
+	if (!(ret)) {
+		printk(KERN_INFO "Unable to process SET_TARGET_PORT_GROUPS"
+				" while TPGS_EXPLICT_ALUA is disabled\n");
+		return PYX_TRANSPORT_UNKNOWN_SAM_OPCODE;
+	}
+
+	while (len < cmd->data_length) {
+		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.
+		 */
+		ret = core_alua_check_transition(alua_access_state, &primary);
+		if (ret != 0) {
+			/*
+			 * 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.
+			 */
+			return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
+		}
+		ret = -1;
+		/*
+		 * 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 = ((ptr[2] << 8) & 0xff);
+			tg_pt_id |= (ptr[3] & 0xff);
+			/*
+			 * Locate the matching target port group ID from
+			 * the global tg_pt_gp list
+			 */
+			spin_lock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+			list_for_each_entry(tg_pt_gp,
+					&T10_ALUA(su_dev)->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(&tg_pt_gp->tg_pt_gp_ref_cnt);
+				smp_mb__after_atomic_inc();
+				spin_unlock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+
+				ret = core_alua_do_port_transition(tg_pt_gp,
+						dev, l_port, nacl,
+						alua_access_state, 1);
+
+				spin_lock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+				atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
+				smp_mb__after_atomic_dec();
+				break;
+			}
+			spin_unlock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+			/*
+			 * If not matching target port group ID can be located
+			 * throw an exception with ASCQ: INVALID_PARAMETER_LIST
+			 */
+			if (ret != 0)
+				return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
+		} else {
+			rtpi = ((ptr[2] << 8) & 0xff);
+			rtpi |= (ptr[3] & 0xff);
+			/*
+			 * Locate the matching relative target port identifer
+			 * for the se_device_t storage object.
+			 */
+			spin_lock(&dev->se_port_lock);
+			list_for_each_entry(port, &dev->dev_sep_list,
+							sep_list) {
+				if (port->sep_rtpi != rtpi)
+					continue;
+
+				tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
+				spin_unlock(&dev->se_port_lock);
+
+				ret = core_alua_set_tg_pt_secondary_state(
+						tg_pt_gp_mem, port, 1, 1);
+
+				spin_lock(&dev->se_port_lock);
+				break;
+			}
+			spin_unlock(&dev->se_port_lock);
+			/*
+			 * If not matching relative target port identifier can
+			 * be located, throw an exception with ASCQ:
+			 * INVALID_PARAMETER_LIST
+			 */
+			if (ret != 0)
+				return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
+		}
+
+		ptr += 4;
+		len += 4;
+	}
+
+	return 0;
+}
+
+static inline int core_alua_state_optimized(
+	struct se_cmd_s *cmd,
+	unsigned char *cdb,
+	u8 *alua_ascq)
+{
+	/*
+	 * For the Optimized ALUA access state case, we want to process the
+	 * incoming fabric cmd ASAP..
+	 */
+	return 0;
+}
+
+static inline int core_alua_state_nonoptimized(
+	struct se_cmd_s *cmd,
+	unsigned char *cdb,
+	int nonop_delay_msecs,
+	u8 *alua_ascq)
+{
+	/*
+	 * 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;
+	return 0;
+}
+
+static inline int core_alua_state_standby(
+	struct se_cmd_s *cmd,
+	unsigned char *cdb,
+	u8 *alua_ascq)
+{
+	/*
+	 * 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 0xa3:
+		switch (cdb[1]) {
+		case MI_REPORT_TARGET_PGS:
+			return 0;
+		default:
+			*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
+			return 1;
+		}
+	case 0xa4:
+		switch (cdb[1]) {
+		case MO_SET_TARGET_PGS:
+			return 0;
+		default:
+			*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
+			return 1;
+		}
+	case REQUEST_SENSE:
+	case PERSISTENT_RESERVE_IN:
+	case PERSISTENT_RESERVE_OUT:
+	case READ_BUFFER:
+	case WRITE_BUFFER:
+		return 0;
+	default:
+		*alua_ascq = ASCQ_04H_ALUA_TG_PT_STANDBY;
+		return 1;
+	}
+
+	return 0;
+}
+
+static inline int core_alua_state_unavailable(
+	struct se_cmd_s *cmd,
+	unsigned char *cdb,
+	u8 *alua_ascq)
+{
+	/*
+	 * 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:
+	case 0xa3:
+		switch (cdb[1]) {
+		case MI_REPORT_TARGET_PGS:
+			return 0;
+		default:
+			*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
+			return 1;
+		}
+	case 0xa4:
+		switch (cdb[1]) {
+		case MO_SET_TARGET_PGS:
+			return 0;
+		default:
+			*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
+			return 1;
+		}
+	case REQUEST_SENSE:
+	case READ_BUFFER:
+	case WRITE_BUFFER:
+		return 0;
+	default:
+		*alua_ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE;
+		return 1;
+	}
+
+	return 0;
+}
+
+static inline int core_alua_state_transition(
+	struct se_cmd_s *cmd,
+	unsigned char *cdb,
+	u8 *alua_ascq)
+{
+	/*
+	 * Allowed CDBs for ALUA_ACCESS_STATE_TRANSITIO as defined by
+	 * spc4r17 section 5.9.2.5
+	 */
+	switch (cdb[0]) {
+	case INQUIRY:
+	case REPORT_LUNS:
+	case 0xa3:
+		switch (cdb[1]) {
+		case MI_REPORT_TARGET_PGS:
+			return 0;
+		default:
+			*alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
+			return 1;
+		}
+	case REQUEST_SENSE:
+	case READ_BUFFER:
+	case WRITE_BUFFER:
+		return 0;
+	default:
+		*alua_ascq = ASCQ_04H_ALUA_STATE_TRANSITION;
+		return 1;
+	}
+
+	return 0;
+}
+
+/*
+ * Used for alua_type SPC_ALUA_PASSTHROUGH and SPC2_ALUA_DISABLED
+ */
+int core_alua_state_check_nop(
+	struct se_cmd_s *cmd,
+	unsigned char *cdb,
+	u8 *alua_ascq)
+{
+	return 0;
+}
+
+/*
+ * Used for alua_type SPC3_ALUA_EMULATED
+ */
+int core_alua_state_check(
+	struct se_cmd_s *cmd,
+	unsigned char *cdb,
+	u8 *alua_ascq)
+{
+	se_lun_t *lun = SE_LUN(cmd);
+	se_port_t *port = lun->lun_sep;
+	t10_alua_tg_pt_gp_t *tg_pt_gp;
+	t10_alua_tg_pt_gp_member_t *tg_pt_gp_mem;
+	int out_alua_state, nonop_delay_msecs;
+
+	if (!(port))
+		return 0;
+	/*
+	 * First, check for a se_port_t specific secondary ALUA target port
+	 * access state: OFFLINE
+	 */
+	if (atomic_read(&port->sep_tg_pt_secondary_offline)) {
+		*alua_ascq = ASCQ_04H_ALUA_OFFLINE;
+		printk(KERN_INFO "ALUA: Got secondary offline status for local"
+				" target port\n");
+		*alua_ascq = ASCQ_04H_ALUA_OFFLINE;
+		return 1;
+	}
+	 /*
+	 * Second, obtain the t10_alua_tg_pt_gp_member_t pointer to the
+	 * ALUA target port group, to obtain current ALUA access state.
+	 * Otherwise look for the underlying se_device_t association with
+	 * a ALUA logical unit group.
+	 */
+	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
+	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
+	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
+	out_alua_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
+	nonop_delay_msecs = tg_pt_gp->tg_pt_gp_nonop_delay_msecs;
+	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
+	/*
+	 * Process ALUA_ACCESS_STATE_ACTIVE_OPTMIZED in a seperate conditional
+	 * statement so the complier knows explictly to check this case first.
+	 */
+	if (out_alua_state == ALUA_ACCESS_STATE_ACTIVE_OPTMIZED)
+		return core_alua_state_optimized(cmd, cdb, alua_ascq);
+
+	switch (out_alua_state) {
+	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
+		return core_alua_state_nonoptimized(cmd, cdb,
+					nonop_delay_msecs, alua_ascq);
+	case ALUA_ACCESS_STATE_STANDBY:
+		return core_alua_state_standby(cmd, cdb, alua_ascq);
+	case ALUA_ACCESS_STATE_UNAVAILABLE:
+		return core_alua_state_unavailable(cmd, cdb, alua_ascq);
+	case ALUA_ACCESS_STATE_TRANSITION:
+		return core_alua_state_transition(cmd, cdb, alua_ascq);
+	/*
+	 * OFFLINE is a secondary ALUA target port group access state, that is
+	 * handled above with se_port_t->sep_tg_pt_secondary_offline=1
+	 */
+	case ALUA_ACCESS_STATE_OFFLINE:
+	default:
+		printk(KERN_ERR "Unknown ALUA access state: 0x%02x\n",
+				out_alua_state);
+		return -1;
+	}
+
+	return 0;
+}
+
+/*
+ * Check implict and explict ALUA state change request.
+ */
+int core_alua_check_transition(int state, int *primary)
+{
+	switch (state) {
+	case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
+	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
+	case ALUA_ACCESS_STATE_STANDBY:
+	case ALUA_ACCESS_STATE_UNAVAILABLE:
+		/*
+		 * OPTIMIZED, NON-OPTIMIZED, STANDBY and UNAVAILABLE are
+		 * defined as primary target port asymmetric access states.
+		 */
+		*primary = 1;
+		break;
+	case ALUA_ACCESS_STATE_OFFLINE:
+		/*
+		 * OFFLINE state is defined as a secondary target port
+		 * asymmetric access state.
+		 */
+		*primary = 0;
+		break;
+	default:
+		printk(KERN_ERR "Unknown ALUA access state: 0x%02x\n", state);
+		return -1;
+	}
+
+	return 0;
+}
+
+char *core_alua_dump_state(int state)
+{
+	switch (state) {
+	case ALUA_ACCESS_STATE_ACTIVE_OPTMIZED:
+		return "Active/Optimized";
+	case ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED:
+		return "Active/NonOptimized";
+	case ALUA_ACCESS_STATE_STANDBY:
+		return "Standby";
+	case ALUA_ACCESS_STATE_UNAVAILABLE:
+		return "Unavailable";
+	case ALUA_ACCESS_STATE_OFFLINE:
+		return "Offline";
+	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_EXPLICT_STPG:
+		return "Altered by Explict STPG";
+	case ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA:
+		return "Altered by Implict 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(
+	se_cmd_t *cmd)
+{
+	if (!(cmd->se_cmd_flags & SCF_ALUA_NON_OPTIMIZED))
+		return 0;
+	if (in_interrupt())
+		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;
+	/*
+	 * se_cmd_t->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);
+
+/*
+ * Called with tg_pt_gp->tg_pt_gp_md_mutex or tg_pt_gp_mem->sep_tg_pt_md_mutex
+ *
+ */
+int core_alua_write_tpg_metadata(
+	const char *path,
+	unsigned char *md_buf,
+	u32 md_buf_len)
+{
+	mm_segment_t old_fs;
+	struct file *file;
+	struct iovec iov[1];
+	int flags = O_RDWR | O_CREAT | O_TRUNC, ret;
+
+	memset(iov, 0, sizeof(struct iovec));
+
+	file = filp_open(path, flags, 0600);
+	if (IS_ERR(file) || !file || !file->f_dentry) {
+		printk(KERN_ERR "filp_open(%s) for ALUA metadata failed\n",
+			path);
+		return -1;
+	}
+
+	iov[0].iov_base = &md_buf[0];
+	iov[0].iov_len = md_buf_len;
+
+	old_fs = get_fs();
+	set_fs(get_ds());
+	ret = vfs_writev(file, &iov[0], 1, &file->f_pos);
+	set_fs(old_fs);
+
+	if (ret < 0) {
+		printk(KERN_ERR "Error writing ALUA metadata file: %s\n", path);
+		filp_close(file, NULL);
+		return -1;
+	}
+	filp_close(file, NULL);
+
+	return 0;
+}
+
+/*
+ * Called with tg_pt_gp->tg_pt_gp_md_mutex held
+ */
+int core_alua_update_tpg_primary_metadata(
+	t10_alua_tg_pt_gp_t *tg_pt_gp,
+	int primary_state,
+	unsigned char *md_buf)
+{
+	se_subsystem_dev_t *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
+	t10_wwn_t *wwn = &su_dev->t10_wwn;
+	char path[512];
+	int len;
+
+	memset(path, 0, 512);
+
+	len = snprintf(md_buf, tg_pt_gp->tg_pt_gp_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, primary_state,
+			tg_pt_gp->tg_pt_gp_alua_access_status);
+
+	snprintf(path, 512, "/var/target/alua/tpgs_%s/%s",
+		&wwn->unit_serial[0],
+		config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item));
+
+	return core_alua_write_tpg_metadata(path, md_buf, len);
+}
+
+int core_alua_do_transition_tg_pt(
+	t10_alua_tg_pt_gp_t *tg_pt_gp,
+	se_port_t *l_port,
+	se_node_acl_t *nacl,
+	unsigned char *md_buf,
+	int new_state,
+	int explict)
+{
+	se_dev_entry_t *se_deve;
+	se_lun_acl_t *lacl;
+	se_port_t *port;
+	t10_alua_tg_pt_gp_member_t *mem;
+	int old_state = 0;
+	/*
+	 * Save the old primary ALUA access state, and set the current state
+	 * to ALUA_ACCESS_STATE_TRANSITION.
+	 */
+	old_state = atomic_read(&tg_pt_gp->tg_pt_gp_alua_access_state);
+	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
+			ALUA_ACCESS_STATE_TRANSITION);
+	tg_pt_gp->tg_pt_gp_alua_access_status = (explict) ?
+				ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
+				ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
+	/*
+	 * 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);
+
+	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
+	list_for_each_entry(mem, &tg_pt_gp->tg_pt_gp_mem_list,
+				tg_pt_gp_mem_list) {
+		port = mem->tg_pt;
+		/*
+		 * 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 CHAGED.
+		 *
+		 * 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
+		 */
+		atomic_inc(&mem->tg_pt_gp_mem_ref_cnt);
+		smp_mb__after_atomic_inc();
+		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
+
+		spin_lock_bh(&port->sep_alua_lock);
+		list_for_each_entry(se_deve, &port->sep_alua_list,
+					alua_port_list) {
+			lacl = se_deve->se_lun_acl;
+			if (explict &&
+			   (nacl != NULL) && (nacl == lacl->se_lun_nacl) &&
+			   (l_port != NULL) && (l_port == port))
+				continue;
+
+			core_scsi3_ua_allocate(lacl->se_lun_nacl,
+				se_deve->mapped_lun, 0x2A,
+				ASCQ_2AH_ASYMMETRIC_ACCESS_STATE_CHANGED);
+		}
+		spin_unlock_bh(&port->sep_alua_lock);
+
+		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
+		atomic_dec(&mem->tg_pt_gp_mem_ref_cnt);
+		smp_mb__after_atomic_dec();
+	}
+	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
+	/*
+	 * 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) {
+		mutex_lock(&tg_pt_gp->tg_pt_gp_md_mutex);
+		core_alua_update_tpg_primary_metadata(tg_pt_gp,
+					new_state, md_buf);
+		mutex_unlock(&tg_pt_gp->tg_pt_gp_md_mutex);
+	}
+	/*
+	 * Set the current primary ALUA access state to the requested new state
+	 */
+	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state, new_state);
+
+	printk(KERN_INFO "Successful %s ALUA transition TG PT Group: %s ID: %hu"
+		" from primary access state %s to %s\n", (explict) ? "explict" :
+		"implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
+		tg_pt_gp->tg_pt_gp_id, core_alua_dump_state(old_state),
+		core_alua_dump_state(new_state));
+
+	return 0;
+}
+
+int core_alua_do_port_transition(
+	t10_alua_tg_pt_gp_t *l_tg_pt_gp,
+	se_device_t *l_dev,
+	se_port_t *l_port,
+	se_node_acl_t *l_nacl,
+	int new_state,
+	int explict)
+{
+	se_device_t *dev;
+	se_port_t *port;
+	se_subsystem_dev_t *su_dev;
+	se_node_acl_t *nacl;
+	t10_alua_lu_gp_t *lu_gp;
+	t10_alua_lu_gp_member_t *lu_gp_mem, *local_lu_gp_mem;
+	t10_alua_tg_pt_gp_t *tg_pt_gp;
+	unsigned char *md_buf;
+	int primary;
+
+	if (core_alua_check_transition(new_state, &primary) != 0)
+		return -1;
+
+	md_buf = kzalloc(l_tg_pt_gp->tg_pt_gp_md_buf_len, GFP_KERNEL);
+	if (!(md_buf)) {
+		printk("Unable to allocate buf for ALUA metadata\n");
+		return -1;
+	}
+
+	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);
+	smp_mb__after_atomic_inc();
+	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.
+		 */
+		core_alua_do_transition_tg_pt(l_tg_pt_gp, l_port, l_nacl,
+					md_buf, new_state, explict);
+		atomic_dec(&lu_gp->lu_gp_ref_cnt);
+		smp_mb__after_atomic_dec();
+		kfree(md_buf);
+		return 0;
+	}
+	/*
+	 * 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;
+		su_dev = dev->se_sub_dev;
+		atomic_inc(&lu_gp_mem->lu_gp_mem_ref_cnt);
+		smp_mb__after_atomic_inc();
+		spin_unlock(&lu_gp->lu_gp_lock);
+
+		spin_lock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+		list_for_each_entry(tg_pt_gp,
+				&T10_ALUA(su_dev)->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 accessiable 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) {
+				port = l_port;
+				nacl = l_nacl;
+			} else {
+				port = NULL;
+				nacl = NULL;
+			}
+			atomic_inc(&tg_pt_gp->tg_pt_gp_ref_cnt);
+			smp_mb__after_atomic_inc();
+			spin_unlock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+			/*
+			 * core_alua_do_transition_tg_pt() will always return
+			 * success.
+			 */
+			core_alua_do_transition_tg_pt(tg_pt_gp, port,
+					nacl, md_buf, new_state, explict);
+
+			spin_lock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+			atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
+			smp_mb__after_atomic_dec();
+		}
+		spin_unlock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+
+		spin_lock(&lu_gp->lu_gp_lock);
+		atomic_dec(&lu_gp_mem->lu_gp_mem_ref_cnt);
+		smp_mb__after_atomic_dec();
+	}
+	spin_unlock(&lu_gp->lu_gp_lock);
+
+	printk(KERN_INFO "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, (explict) ? "explict" : "implict",
+		core_alua_dump_state(new_state));
+
+	atomic_dec(&lu_gp->lu_gp_ref_cnt);
+	smp_mb__after_atomic_dec();
+	kfree(md_buf);
+	return 0;
+}
+
+/*
+ * Called with tg_pt_gp_mem->sep_tg_pt_md_mutex held
+ */
+int core_alua_update_tpg_secondary_metadata(
+	struct t10_alua_tg_pt_gp_member_s *tg_pt_gp_mem,
+	se_port_t *port,
+	unsigned char *md_buf,
+	u32 md_buf_len)
+{
+	se_portal_group_t *se_tpg = port->sep_tpg;
+	char path[512], wwn[1024];
+	int len;
+
+	memset(path, 0, 512);
+	memset(wwn, 0, 1024);
+
+	len = snprintf(wwn, 512, "%s",
+			TPG_TFO(se_tpg)->tpg_get_wwn(se_tpg));
+
+	if (TPG_TFO(se_tpg)->tpg_get_tag != NULL)
+		snprintf(wwn+len, 1024-len, "+%hu",
+				TPG_TFO(se_tpg)->tpg_get_tag(se_tpg));
+
+	len = snprintf(md_buf, md_buf_len, "alua_tg_pt_offline=%d\n"
+			"alua_tg_pt_status=0x%02x\n",
+			atomic_read(&port->sep_tg_pt_secondary_offline),
+			port->sep_tg_pt_secondary_stat);
+
+	snprintf(path, 512, "/var/target/alua/%s/%s/lun_%u",
+			TPG_TFO(se_tpg)->get_fabric_name(), wwn,
+			port->sep_lun->unpacked_lun);
+
+	return core_alua_write_tpg_metadata(path, md_buf, len);
+}
+
+int core_alua_set_tg_pt_secondary_state(
+	struct t10_alua_tg_pt_gp_member_s *tg_pt_gp_mem,
+	se_port_t *port,
+	int explict,
+	int offline)
+{
+	struct t10_alua_tg_pt_gp_s *tg_pt_gp;
+	unsigned char *md_buf;
+	u32 md_buf_len;
+	int trans_delay_msecs;
+
+	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
+	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
+	if (!(tg_pt_gp)) {
+		spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
+		printk(KERN_ERR "Unable to complete secondary state"
+				" transition\n");
+		return -1;
+	}
+	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 se_port_t
+	 */
+	if (offline)
+		atomic_set(&port->sep_tg_pt_secondary_offline, 1);
+	else
+		atomic_set(&port->sep_tg_pt_secondary_offline, 0);
+
+	md_buf_len = tg_pt_gp->tg_pt_gp_md_buf_len;
+	port->sep_tg_pt_secondary_stat = (explict) ?
+			ALUA_STATUS_ALTERED_BY_EXPLICT_STPG :
+			ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA;
+
+	printk(KERN_INFO "Successful %s ALUA transition TG PT Group: %s ID: %hu"
+		" to secondary access state: %s\n", (explict) ? "explict" :
+		"implict", config_item_name(&tg_pt_gp->tg_pt_gp_group.cg_item),
+		tg_pt_gp->tg_pt_gp_id, (offline) ? "OFFLINE" : "ONLINE");
+
+	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
+	/*
+	 * 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 (port->sep_tg_pt_secondary_write_md) {
+		md_buf = kzalloc(md_buf_len, GFP_KERNEL);
+		if (!(md_buf)) {
+			printk(KERN_ERR "Unable to allocate md_buf for"
+				" secondary ALUA access metadata\n");
+			return -1;
+		}
+		mutex_lock(&port->sep_tg_pt_md_mutex);
+		core_alua_update_tpg_secondary_metadata(tg_pt_gp_mem, port,
+				md_buf, md_buf_len);
+		mutex_unlock(&port->sep_tg_pt_md_mutex);
+
+		kfree(md_buf);
+	}
+
+	return 0;
+}
+
+t10_alua_lu_gp_t *core_alua_allocate_lu_gp(const char *name, int def_group)
+{
+	t10_alua_lu_gp_t *lu_gp;
+
+	lu_gp = kmem_cache_zalloc(t10_alua_lu_gp_cache, GFP_KERNEL);
+	if (!(lu_gp)) {
+		printk(KERN_ERR "Unable to allocate t10_alua_lu_gp_t\n");
+		return NULL;
+	}
+	INIT_LIST_HEAD(&lu_gp->lu_gp_list);
+	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 = se_global->alua_lu_gps_counter++;;
+		lu_gp->lu_gp_valid_id = 1;
+		se_global->alua_lu_gps_count++;
+	}
+
+	return lu_gp;
+}
+
+int core_alua_set_lu_gp_id(t10_alua_lu_gp_t *lu_gp, u16 lu_gp_id)
+{
+	t10_alua_lu_gp_t *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) {
+		printk(KERN_ERR "ALUA LU Group already has a valid ID,"
+			" ignoring request\n");
+		return -1;
+	}
+
+	spin_lock(&se_global->lu_gps_lock);
+	if (se_global->alua_lu_gps_count == 0x0000ffff) {
+		printk(KERN_ERR "Maximum ALUA se_global->alua_lu_gps_count:"
+				" 0x0000ffff reached\n");
+		spin_unlock(&se_global->lu_gps_lock);
+		kmem_cache_free(t10_alua_lu_gp_cache, lu_gp);
+		return -1;
+	}
+again:
+	lu_gp_id_tmp = (lu_gp_id != 0) ? lu_gp_id :
+				se_global->alua_lu_gps_counter++;
+
+	list_for_each_entry(lu_gp_tmp, &se_global->g_lu_gps_list, lu_gp_list) {
+		if (lu_gp_tmp->lu_gp_id == lu_gp_id_tmp) {
+			if (!(lu_gp_id))
+				goto again;
+
+			printk(KERN_ERR "ALUA Logical Unit Group ID: %hu"
+				" already exists, ignoring request\n",
+				lu_gp_id);
+			spin_unlock(&se_global->lu_gps_lock);
+			return -1;
+		}
+	}
+
+	lu_gp->lu_gp_id = lu_gp_id_tmp;
+	lu_gp->lu_gp_valid_id = 1;
+	list_add_tail(&lu_gp->lu_gp_list, &se_global->g_lu_gps_list);
+	se_global->alua_lu_gps_count++;
+	spin_unlock(&se_global->lu_gps_lock);
+
+	return 0;
+}
+
+t10_alua_lu_gp_member_t *core_alua_allocate_lu_gp_mem(
+	se_device_t *dev)
+{
+	t10_alua_lu_gp_member_t *lu_gp_mem;
+
+	lu_gp_mem = kmem_cache_zalloc(t10_alua_lu_gp_mem_cache, GFP_KERNEL);
+	if (!(lu_gp_mem)) {
+		printk(KERN_ERR "Unable to allocate t10_alua_lu_gp_member_t\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(t10_alua_lu_gp_t *lu_gp)
+{
+	t10_alua_lu_gp_member_t *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
+	 * t10_alua_lu_gp_t.
+	 */
+	spin_lock(&se_global->lu_gps_lock);
+	atomic_set(&lu_gp->lu_gp_shutdown, 1);
+	list_del(&lu_gp->lu_gp_list);
+	se_global->alua_lu_gps_count--;
+	spin_unlock(&se_global->lu_gps_lock);
+	/*
+	 * Allow t10_alua_lu_gp_t * 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))
+		msleep(10);
+	/*
+	 * Release reference to t10_alua_lu_gp_t * from all associated
+	 * se_device_t.
+	 */
+	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 assoicated with a single
+		 * se_device_t->dev_alua_lu_gp_mem, and is released when
+		 * se_device_t 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-assocate a given lu_gp_mem with default_lu_gp.
+		 */
+		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
+		if (lu_gp != se_global->default_lu_gp)
+			__core_alua_attach_lu_gp_mem(lu_gp_mem,
+					se_global->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(se_device_t *dev)
+{
+	se_subsystem_dev_t *su_dev = dev->se_sub_dev;
+	t10_alua_t *alua = T10_ALUA(su_dev);
+	t10_alua_lu_gp_t *lu_gp;
+	t10_alua_lu_gp_member_t *lu_gp_mem;
+
+	if (alua->alua_type != SPC3_ALUA_EMULATED)
+		return;
+
+	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))
+		msleep(10);
+
+	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);
+}
+
+t10_alua_lu_gp_t *core_alua_get_lu_gp_by_name(const char *name)
+{
+	t10_alua_lu_gp_t *lu_gp;
+	struct config_item *ci;
+
+	spin_lock(&se_global->lu_gps_lock);
+	list_for_each_entry(lu_gp, &se_global->g_lu_gps_list, lu_gp_list) {
+		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(&se_global->lu_gps_lock);
+			return lu_gp;
+		}
+	}
+	spin_unlock(&se_global->lu_gps_lock);
+
+	return NULL;
+}
+
+void core_alua_put_lu_gp_from_name(t10_alua_lu_gp_t *lu_gp)
+{
+	spin_lock(&se_global->lu_gps_lock);
+	atomic_dec(&lu_gp->lu_gp_ref_cnt);
+	spin_unlock(&se_global->lu_gps_lock);
+}
+
+/*
+ * Called with t10_alua_lu_gp_member_t->lu_gp_mem_lock
+ */
+void __core_alua_attach_lu_gp_mem(
+	t10_alua_lu_gp_member_t *lu_gp_mem,
+	t10_alua_lu_gp_t *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 t10_alua_lu_gp_member_t->lu_gp_mem_lock
+ */
+void __core_alua_drop_lu_gp_mem(
+	t10_alua_lu_gp_member_t *lu_gp_mem,
+	t10_alua_lu_gp_t *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);
+}
+
+t10_alua_tg_pt_gp_t *core_alua_allocate_tg_pt_gp(
+	se_subsystem_dev_t *su_dev,
+	const char *name,
+	int def_group)
+{
+	t10_alua_tg_pt_gp_t *tg_pt_gp;
+
+	tg_pt_gp = kmem_cache_zalloc(t10_alua_tg_pt_gp_cache, GFP_KERNEL);
+	if (!(tg_pt_gp)) {
+		printk(KERN_ERR "Unable to allocate t10_alua_tg_pt_gp_t\n");
+		return NULL;
+	}
+	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_list);
+	INIT_LIST_HEAD(&tg_pt_gp->tg_pt_gp_mem_list);
+	mutex_init(&tg_pt_gp->tg_pt_gp_md_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_su_dev = su_dev;
+	tg_pt_gp->tg_pt_gp_md_buf_len = ALUA_MD_BUF_LEN;
+	atomic_set(&tg_pt_gp->tg_pt_gp_alua_access_state,
+		ALUA_ACCESS_STATE_ACTIVE_OPTMIZED);
+	/*
+	 * Enable both explict and implict ALUA support by default
+	 */
+	tg_pt_gp->tg_pt_gp_alua_access_type =
+			TPGS_EXPLICT_ALUA | TPGS_IMPLICT_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;
+
+	if (def_group) {
+		spin_lock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+		tg_pt_gp->tg_pt_gp_id =
+				T10_ALUA(su_dev)->alua_tg_pt_gps_counter++;
+		tg_pt_gp->tg_pt_gp_valid_id = 1;
+		T10_ALUA(su_dev)->alua_tg_pt_gps_count++;
+		list_add_tail(&tg_pt_gp->tg_pt_gp_list,
+			      &T10_ALUA(su_dev)->tg_pt_gps_list);
+		spin_unlock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+	}
+
+	return tg_pt_gp;
+}
+
+int core_alua_set_tg_pt_gp_id(
+	t10_alua_tg_pt_gp_t *tg_pt_gp,
+	u16 tg_pt_gp_id)
+{
+	se_subsystem_dev_t *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
+	t10_alua_tg_pt_gp_t *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) {
+		printk(KERN_ERR "ALUA TG PT Group already has a valid ID,"
+			" ignoring request\n");
+		return -1;
+	}
+
+	spin_lock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+	if (T10_ALUA(su_dev)->alua_tg_pt_gps_count == 0x0000ffff) {
+		printk(KERN_ERR "Maximum ALUA alua_tg_pt_gps_count:"
+			" 0x0000ffff reached\n");
+		spin_unlock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+		kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
+		return -1;
+	}
+again:
+	tg_pt_gp_id_tmp = (tg_pt_gp_id != 0) ? tg_pt_gp_id :
+			T10_ALUA(su_dev)->alua_tg_pt_gps_counter++;
+
+	list_for_each_entry(tg_pt_gp_tmp, &T10_ALUA(su_dev)->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;
+
+			printk(KERN_ERR "ALUA Target Port Group ID: %hu already"
+				" exists, ignoring request\n", tg_pt_gp_id);
+			spin_unlock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+			return -1;
+		}
+	}
+
+	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,
+			&T10_ALUA(su_dev)->tg_pt_gps_list);
+	T10_ALUA(su_dev)->alua_tg_pt_gps_count++;
+	spin_unlock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+
+	return 0;
+}
+
+t10_alua_tg_pt_gp_member_t *core_alua_allocate_tg_pt_gp_mem(
+	se_port_t *port)
+{
+	t10_alua_tg_pt_gp_member_t *tg_pt_gp_mem;
+
+	tg_pt_gp_mem = kmem_cache_zalloc(t10_alua_tg_pt_gp_mem_cache,
+				GFP_KERNEL);
+	if (!(tg_pt_gp_mem)) {
+		printk(KERN_ERR "Unable to allocate t10_alua_tg_pt_gp_member_t\n");
+		return ERR_PTR(-ENOMEM);
+	}
+	INIT_LIST_HEAD(&tg_pt_gp_mem->tg_pt_gp_mem_list);
+	spin_lock_init(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
+	atomic_set(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt, 0);
+
+	tg_pt_gp_mem->tg_pt = port;
+	port->sep_alua_tg_pt_gp_mem = tg_pt_gp_mem;
+	atomic_set(&port->sep_tg_pt_gp_active, 1);
+
+	return tg_pt_gp_mem;
+}
+
+void core_alua_free_tg_pt_gp(
+	t10_alua_tg_pt_gp_t *tg_pt_gp)
+{
+	se_subsystem_dev_t *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
+	t10_alua_tg_pt_gp_member_t *tg_pt_gp_mem, *tg_pt_gp_mem_tmp;
+	/*
+	 * 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 assications *OR* explict ALUA via SET_TARGET_PORT_GROUPS
+	 * can be made while we are releasing t10_alua_tg_pt_gp_t.
+	 */
+	spin_lock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+	list_del(&tg_pt_gp->tg_pt_gp_list);
+	T10_ALUA(su_dev)->alua_tg_pt_gps_counter--;
+	spin_unlock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+	/*
+	 * Allow a t10_alua_tg_pt_gp_member_t * 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))
+		msleep(10);
+	/*
+	 * Release reference to t10_alua_tg_pt_gp_t from all associated
+	 * se_port_t.
+	 */
+	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
+	list_for_each_entry_safe(tg_pt_gp_mem, tg_pt_gp_mem_tmp,
+			&tg_pt_gp->tg_pt_gp_mem_list, tg_pt_gp_mem_list) {
+		if (tg_pt_gp_mem->tg_pt_gp_assoc) {
+			list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
+			tg_pt_gp->tg_pt_gp_members--;
+			tg_pt_gp_mem->tg_pt_gp_assoc = 0;
+		}
+		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
+		/*
+		 * tg_pt_gp_mem is assoicated with a single
+		 * se_port->sep_alua_tg_pt_gp_mem, and is released via
+		 * core_alua_free_tg_pt_gp_mem().
+		 *
+		 * If the passed tg_pt_gp does NOT match the default_tg_pt_gp,
+		 * assume we want to re-assocate a given tg_pt_gp_mem with
+		 * default_tg_pt_gp.
+		 */
+		spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
+		if (tg_pt_gp != T10_ALUA(su_dev)->default_tg_pt_gp) {
+			__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
+					T10_ALUA(su_dev)->default_tg_pt_gp);
+		} else
+			tg_pt_gp_mem->tg_pt_gp = NULL;
+		spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
+
+		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
+	}
+	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
+
+	kmem_cache_free(t10_alua_tg_pt_gp_cache, tg_pt_gp);
+}
+
+void core_alua_free_tg_pt_gp_mem(se_port_t *port)
+{
+	se_subsystem_dev_t *su_dev = port->sep_lun->se_dev->se_sub_dev;
+	t10_alua_t *alua = T10_ALUA(su_dev);
+	t10_alua_tg_pt_gp_t *tg_pt_gp;
+	t10_alua_tg_pt_gp_member_t *tg_pt_gp_mem;
+
+	if (alua->alua_type != SPC3_ALUA_EMULATED)
+		return;
+
+	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
+	if (!(tg_pt_gp_mem))
+		return;
+
+	while (atomic_read(&tg_pt_gp_mem->tg_pt_gp_mem_ref_cnt))
+		msleep(10);
+
+	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
+	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
+	if ((tg_pt_gp)) {
+		spin_lock(&tg_pt_gp->tg_pt_gp_lock);
+		if (tg_pt_gp_mem->tg_pt_gp_assoc) {
+			list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
+			tg_pt_gp->tg_pt_gp_members--;
+			tg_pt_gp_mem->tg_pt_gp_assoc = 0;
+		}
+		spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
+		tg_pt_gp_mem->tg_pt_gp = NULL;
+	}
+	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
+
+	kmem_cache_free(t10_alua_tg_pt_gp_mem_cache, tg_pt_gp_mem);
+}
+
+t10_alua_tg_pt_gp_t *core_alua_get_tg_pt_gp_by_name(
+	se_subsystem_dev_t *su_dev,
+	const char *name)
+{
+	t10_alua_tg_pt_gp_t *tg_pt_gp;
+	struct config_item *ci;
+
+	spin_lock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+	list_for_each_entry(tg_pt_gp, &T10_ALUA(su_dev)->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(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+			return tg_pt_gp;
+		}
+	}
+	spin_unlock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+
+	return NULL;
+}
+
+void core_alua_put_tg_pt_gp_from_name(
+	t10_alua_tg_pt_gp_t *tg_pt_gp)
+{
+	se_subsystem_dev_t *su_dev = tg_pt_gp->tg_pt_gp_su_dev;
+
+	spin_lock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+	atomic_dec(&tg_pt_gp->tg_pt_gp_ref_cnt);
+	spin_unlock(&T10_ALUA(su_dev)->tg_pt_gps_lock);
+}
+
+/*
+ * Called with t10_alua_tg_pt_gp_member_t->tg_pt_gp_mem_lock held
+ */
+void __core_alua_attach_tg_pt_gp_mem(
+	t10_alua_tg_pt_gp_member_t *tg_pt_gp_mem,
+	t10_alua_tg_pt_gp_t *tg_pt_gp)
+{
+	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
+	tg_pt_gp_mem->tg_pt_gp = tg_pt_gp;
+	tg_pt_gp_mem->tg_pt_gp_assoc = 1;
+	list_add_tail(&tg_pt_gp_mem->tg_pt_gp_mem_list,
+			&tg_pt_gp->tg_pt_gp_mem_list);
+	tg_pt_gp->tg_pt_gp_members++;
+	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
+}
+
+/*
+ * Called with t10_alua_tg_pt_gp_member_t->tg_pt_gp_mem_lock held
+ */
+void __core_alua_drop_tg_pt_gp_mem(
+	t10_alua_tg_pt_gp_member_t *tg_pt_gp_mem,
+	t10_alua_tg_pt_gp_t *tg_pt_gp)
+{
+	spin_lock(&tg_pt_gp->tg_pt_gp_lock);
+	list_del(&tg_pt_gp_mem->tg_pt_gp_mem_list);
+	tg_pt_gp_mem->tg_pt_gp = NULL;
+	tg_pt_gp_mem->tg_pt_gp_assoc = 0;
+	tg_pt_gp->tg_pt_gp_members--;
+	spin_unlock(&tg_pt_gp->tg_pt_gp_lock);
+}
+
+ssize_t core_alua_show_tg_pt_gp_info(se_port_t *port, char *page)
+{
+	se_subsystem_dev_t *su_dev = port->sep_lun->se_dev->se_sub_dev;
+	struct config_item *tg_pt_ci;
+	t10_alua_t *alua = T10_ALUA(su_dev);
+	t10_alua_tg_pt_gp_t *tg_pt_gp;
+	t10_alua_tg_pt_gp_member_t *tg_pt_gp_mem;
+	ssize_t len = 0;
+
+	if (alua->alua_type != SPC3_ALUA_EMULATED)
+		return len;
+
+	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
+	if (!(tg_pt_gp_mem))
+		return len;
+
+	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
+	tg_pt_gp = tg_pt_gp_mem->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(atomic_read(
+					&tg_pt_gp->tg_pt_gp_alua_access_state)),
+			core_alua_dump_status(
+				tg_pt_gp->tg_pt_gp_alua_access_status),
+			(atomic_read(&port->sep_tg_pt_secondary_offline)) ?
+			"Offline" : "None",
+			core_alua_dump_status(port->sep_tg_pt_secondary_stat));
+	}
+	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
+
+	return len;
+}
+EXPORT_SYMBOL(core_alua_show_tg_pt_gp_info);
+
+ssize_t core_alua_store_tg_pt_gp_info(
+	se_port_t *port,
+	const char *page,
+	size_t count)
+{
+	se_portal_group_t *tpg;
+	se_lun_t *lun;
+	se_subsystem_dev_t *su_dev = port->sep_lun->se_dev->se_sub_dev;
+	t10_alua_tg_pt_gp_t *tg_pt_gp = NULL, *tg_pt_gp_new = NULL;
+	t10_alua_tg_pt_gp_member_t *tg_pt_gp_mem;
+	unsigned char buf[TG_PT_GROUP_NAME_BUF];
+	int move = 0;
+
+	tpg = port->sep_tpg;
+	lun = port->sep_lun;
+
+	if (T10_ALUA(su_dev)->alua_type != SPC3_ALUA_EMULATED) {
+		printk(KERN_WARNING "SPC3_ALUA_EMULATED not enabled for"
+			" %s/tpgt_%hu/%s\n", TPG_TFO(tpg)->tpg_get_wwn(tpg),
+			TPG_TFO(tpg)->tpg_get_tag(tpg),
+			config_item_name(&lun->lun_group.cg_item));
+		return -EINVAL;
+	}
+
+	if (count > TG_PT_GROUP_NAME_BUF) {
+		printk(KERN_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
+		 * t10_alua_tg_pt_gp_t.  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(su_dev,
+					strstrip(buf));
+		if (!(tg_pt_gp_new))
+			return -ENODEV;
+	}
+	tg_pt_gp_mem = port->sep_alua_tg_pt_gp_mem;
+	if (!(tg_pt_gp_mem)) {
+		if (tg_pt_gp_new)
+			core_alua_put_tg_pt_gp_from_name(tg_pt_gp_new);
+		printk(KERN_ERR "NULL se_port_t->sep_alua_tg_pt_gp_mem pointer\n");
+		return -EINVAL;
+	}
+
+	spin_lock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
+	tg_pt_gp = tg_pt_gp_mem->tg_pt_gp;
+	if ((tg_pt_gp)) {
+		/*
+		 * Clearing an existing tg_pt_gp association, and replacing
+		 * with the default_tg_pt_gp.
+		 */
+		if (!(tg_pt_gp_new)) {
+			printk(KERN_INFO "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_TFO(tpg)->tpg_get_wwn(tpg),
+				TPG_TFO(tpg)->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);
+
+			__core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
+			__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem,
+					T10_ALUA(su_dev)->default_tg_pt_gp);
+			spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
+
+			return count;
+		}
+		/*
+		 * Removing existing association of tg_pt_gp_mem with tg_pt_gp
+		 */
+		__core_alua_drop_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp);
+		move = 1;
+	}
+	/*
+	 * Associate tg_pt_gp_mem with tg_pt_gp_new.
+	 */
+	__core_alua_attach_tg_pt_gp_mem(tg_pt_gp_mem, tg_pt_gp_new);
+	spin_unlock(&tg_pt_gp_mem->tg_pt_gp_mem_lock);
+	printk("Target_Core_ConfigFS: %s %s/tpgt_%hu/%s to ALUA Target Port"
+		" Group: alua/%s, ID: %hu\n", (move) ?
+		"Moving" : "Adding", TPG_TFO(tpg)->tpg_get_wwn(tpg),
+		TPG_TFO(tpg)->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);
+	return count;
+}
+EXPORT_SYMBOL(core_alua_store_tg_pt_gp_info);
+
+ssize_t core_alua_show_access_type(
+	t10_alua_tg_pt_gp_t *tg_pt_gp,
+	char *page)
+{
+	if ((tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA) &&
+	    (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA))
+		return sprintf(page, "Implict and Explict\n");
+	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_IMPLICT_ALUA)
+		return sprintf(page, "Implict\n");
+	else if (tg_pt_gp->tg_pt_gp_alua_access_type & TPGS_EXPLICT_ALUA)
+		return sprintf(page, "Explict\n");
+	else
+		return sprintf(page, "None\n");
+}
+
+ssize_t core_alua_store_access_type(
+	t10_alua_tg_pt_gp_t *tg_pt_gp,
+	const char *page,
+	size_t count)
+{
+	unsigned long tmp;
+	int ret;
+
+	ret = strict_strtoul(page, 0, &tmp);
+	if (ret < 0) {
+		printk(KERN_ERR "Unable to extract alua_access_type\n");
+		return -EINVAL;
+	}
+	if ((tmp != 0) && (tmp != 1) && (tmp != 2) && (tmp != 3)) {
+		printk(KERN_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_IMPLICT_ALUA | TPGS_EXPLICT_ALUA;
+	else if (tmp == 2)
+		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_EXPLICT_ALUA;
+	else if (tmp == 1)
+		tg_pt_gp->tg_pt_gp_alua_access_type = TPGS_IMPLICT_ALUA;
+	else
+		tg_pt_gp->tg_pt_gp_alua_access_type = 0;
+
+	return count;
+}
+
+ssize_t core_alua_show_nonop_delay_msecs(
+	t10_alua_tg_pt_gp_t *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(
+	t10_alua_tg_pt_gp_t *tg_pt_gp,
+	const char *page,
+	size_t count)
+{
+	unsigned long tmp;
+	int ret;
+
+	ret = strict_strtoul(page, 0, &tmp);
+	if (ret < 0) {
+		printk(KERN_ERR "Unable to extract nonop_delay_msecs\n");
+		return -EINVAL;
+	}
+	if (tmp > ALUA_MAX_NONOP_DELAY_MSECS) {
+		printk(KERN_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(
+	t10_alua_tg_pt_gp_t *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(
+	t10_alua_tg_pt_gp_t *tg_pt_gp,
+	const char *page,
+	size_t count)
+{
+	unsigned long tmp;
+	int ret;
+
+	ret = strict_strtoul(page, 0, &tmp);
+	if (ret < 0) {
+		printk(KERN_ERR "Unable to extract trans_delay_msecs\n");
+		return -EINVAL;
+	}
+	if (tmp > ALUA_MAX_TRANS_DELAY_MSECS) {
+		printk(KERN_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_preferred_bit(
+	t10_alua_tg_pt_gp_t *tg_pt_gp,
+	char *page)
+{
+	return sprintf(page, "%d\n", tg_pt_gp->tg_pt_gp_pref);
+}
+
+ssize_t core_alua_store_preferred_bit(
+	t10_alua_tg_pt_gp_t *tg_pt_gp,
+	const char *page,
+	size_t count)
+{
+	unsigned long tmp;
+	int ret;
+
+	ret = strict_strtoul(page, 0, &tmp);
+	if (ret < 0) {
+		printk(KERN_ERR "Unable to extract preferred ALUA value\n");
+		return -EINVAL;
+	}
+	if ((tmp != 0) && (tmp != 1)) {
+		printk(KERN_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(se_lun_t *lun, char *page)
+{
+	if (!(lun->lun_sep))
+		return -ENODEV;
+
+	return sprintf(page, "%d\n",
+		atomic_read(&lun->lun_sep->sep_tg_pt_secondary_offline));
+}
+EXPORT_SYMBOL(core_alua_show_offline_bit);
+
+ssize_t core_alua_store_offline_bit(
+	se_lun_t *lun,
+	const char *page,
+	size_t count)
+{
+	t10_alua_tg_pt_gp_member_t *tg_pt_gp_mem;
+	unsigned long tmp;
+	int ret;
+
+	if (!(lun->lun_sep))
+		return -ENODEV;
+
+	ret = strict_strtoul(page, 0, &tmp);
+	if (ret < 0) {
+		printk(KERN_ERR "Unable to extract alua_tg_pt_offline value\n");
+		return -EINVAL;
+	}
+	if ((tmp != 0) && (tmp != 1)) {
+		printk(KERN_ERR "Illegal value for alua_tg_pt_offline: %lu\n",
+				tmp);
+		return -EINVAL;
+	}
+	tg_pt_gp_mem = lun->lun_sep->sep_alua_tg_pt_gp_mem;
+	if (!(tg_pt_gp_mem)) {
+		printk(KERN_ERR "Unable to locate *tg_pt_gp_mem\n");
+		return -EINVAL;
+	}
+
+	ret = core_alua_set_tg_pt_secondary_state(tg_pt_gp_mem,
+			lun->lun_sep, 0, (int)tmp);
+	if (ret < 0)
+		return -EINVAL;
+
+	return count;
+}
+EXPORT_SYMBOL(core_alua_store_offline_bit);
+
+ssize_t core_alua_show_secondary_status(
+	se_lun_t *lun,
+	char *page)
+{
+	return sprintf(page, "%d\n", lun->lun_sep->sep_tg_pt_secondary_stat);
+}
+EXPORT_SYMBOL(core_alua_show_secondary_status);
+
+ssize_t core_alua_store_secondary_status(
+	se_lun_t *lun,
+	const char *page,
+	size_t count)
+{
+	unsigned long tmp;
+	int ret;
+
+	ret = strict_strtoul(page, 0, &tmp);
+	if (ret < 0) {
+		printk(KERN_ERR "Unable to extract alua_tg_pt_status\n");
+		return -EINVAL;
+	}
+	if ((tmp != ALUA_STATUS_NONE) &&
+	    (tmp != ALUA_STATUS_ALTERED_BY_EXPLICT_STPG) &&
+	    (tmp != ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA)) {
+		printk(KERN_ERR "Illegal value for alua_tg_pt_status: %lu\n",
+				tmp);
+		return -EINVAL;
+	}
+	lun->lun_sep->sep_tg_pt_secondary_stat = (int)tmp;
+
+	return count;
+}
+EXPORT_SYMBOL(core_alua_store_secondary_status);
+
+ssize_t core_alua_show_secondary_write_metadata(
+	se_lun_t *lun,
+	char *page)
+{
+	return sprintf(page, "%d\n",
+			lun->lun_sep->sep_tg_pt_secondary_write_md);
+}
+EXPORT_SYMBOL(core_alua_show_secondary_write_metadata);
+
+ssize_t core_alua_store_secondary_write_metadata(
+	se_lun_t *lun,
+	const char *page,
+	size_t count)
+{
+	unsigned long tmp;
+	int ret;
+
+	ret = strict_strtoul(page, 0, &tmp);
+	if (ret < 0) {
+		printk(KERN_ERR "Unable to extract alua_tg_pt_write_md\n");
+		return -EINVAL;
+	}
+	if ((tmp != 0) && (tmp != 1)) {
+		printk(KERN_ERR "Illegal value for alua_tg_pt_write_md:"
+				" %lu\n", tmp);
+		return -EINVAL;
+	}
+	lun->lun_sep->sep_tg_pt_secondary_write_md = (int)tmp;
+
+	return count;
+}
+EXPORT_SYMBOL(core_alua_store_secondary_write_metadata);
+
+int core_setup_alua(se_device_t *dev)
+{
+	se_subsystem_dev_t *su_dev = dev->se_sub_dev;
+	t10_alua_t *alua = T10_ALUA(su_dev);
+	t10_alua_lu_gp_member_t *lu_gp_mem;
+	/*
+	 * If this device is from Target_Core_Mod/pSCSI, use the ALUA logic
+	 * of the Underlying SCSI hardware.  In Linux/SCSI terms, this can
+	 * cause a problem because libata and some SATA RAID HBAs appear
+	 * under Linux/SCSI, but emulate SCSI logic themselves.
+	 */
+	if ((TRANSPORT(dev)->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) &&
+	    !(DEV_ATTRIB(dev)->emulate_alua)) {
+		alua->alua_type = SPC_ALUA_PASSTHROUGH;
+		alua->alua_state_check = &core_alua_state_check_nop;
+		printk(KERN_INFO "%s: Using SPC_ALUA_PASSTHROUGH, no ALUA"
+			" emulation\n", TRANSPORT(dev)->name);
+		return 0;
+	}
+	/*
+	 * If SPC-3 or above is reported by real or emulated se_device_t,
+	 * use emulated ALUA.
+	 */
+	if (TRANSPORT(dev)->get_device_rev(dev) >= SCSI_3) {
+		printk(KERN_INFO "%s: Enabling ALUA Emulation for SPC-3"
+			" device\n", TRANSPORT(dev)->name);
+		/*
+		 * Assoicate this se_device_t with the default ALUA
+		 * LUN Group.
+		 */
+		lu_gp_mem = core_alua_allocate_lu_gp_mem(dev);
+		if (IS_ERR(lu_gp_mem) || !lu_gp_mem)
+			return -1;
+
+		alua->alua_type = SPC3_ALUA_EMULATED;
+		alua->alua_state_check = &core_alua_state_check;
+		spin_lock(&lu_gp_mem->lu_gp_mem_lock);
+		__core_alua_attach_lu_gp_mem(lu_gp_mem,
+				se_global->default_lu_gp);
+		spin_unlock(&lu_gp_mem->lu_gp_mem_lock);
+
+		printk(KERN_INFO "%s: Adding to default ALUA LU Group:"
+			" core/alua/lu_gps/default_lu_gp\n",
+			TRANSPORT(dev)->name);
+	} else {
+		alua->alua_type = SPC2_ALUA_DISABLED;
+		alua->alua_state_check = &core_alua_state_check_nop;
+		printk("%s: Disabling ALUA Emulation for SPC-2 device\n",
+				TRANSPORT(dev)->name);
+	}
+
+	return 0;
+}
diff --git a/include/target/target_core_alua.h b/include/target/target_core_alua.h
new file mode 100644
index 0000000..4e5a107
--- /dev/null
+++ b/include/target/target_core_alua.h
@@ -0,0 +1,134 @@
+#ifndef TARGET_CORE_ALUA_H
+#define TARGET_CORE_ALUA_H
+
+/*
+ * INQUIRY response data, TPGS Field
+ *
+ * from spc4r17 section 6.4.2 Table 135
+ */
+#define TPGS_NO_ALUA				0x00
+#define TPGS_IMPLICT_ALUA			0x10
+#define TPGS_EXPLICT_ALUA			0x20
+
+/*
+ * ASYMMETRIC ACCESS STATE field
+ *
+ * from spc4r17 section 6.27 Table 245
+ */
+#define ALUA_ACCESS_STATE_ACTIVE_OPTMIZED	0x0
+#define ALUA_ACCESS_STATE_ACTIVE_NON_OPTIMIZED	0x1
+#define ALUA_ACCESS_STATE_STANDBY		0x2
+#define ALUA_ACCESS_STATE_UNAVAILABLE		0x3
+#define ALUA_ACCESS_STATE_OFFLINE		0xe
+#define ALUA_ACCESS_STATE_TRANSITION		0xf
+
+/*
+ * REPORT_TARGET_PORT_GROUP STATUS CODE
+ *
+ * from spc4r17 section 6.27 Table 246
+ */
+#define ALUA_STATUS_NONE				0x00
+#define ALUA_STATUS_ALTERED_BY_EXPLICT_STPG		0x01
+#define ALUA_STATUS_ALTERED_BY_IMPLICT_ALUA		0x02
+
+/*
+ * From spc4r17, Table D.1: ASC and ASCQ Assignement
+ */
+#define ASCQ_04H_ALUA_STATE_TRANSITION			0x0a
+#define ASCQ_04H_ALUA_TG_PT_STANDBY			0x0b
+#define ASCQ_04H_ALUA_TG_PT_UNAVAILABLE			0x0c
+#define ASCQ_04H_ALUA_OFFLINE				0x12
+
+/*
+ * Used as the default for Active/NonOptimized delay (in milliseconds)
+ * This can also be changed via configfs on a per target port group basis..
+ */
+#define ALUA_DEFAULT_NONOP_DELAY_MSECS			100
+#define ALUA_MAX_NONOP_DELAY_MSECS			10000 /* 10 seconds */
+/*
+ * Used for implict and explict ALUA transitional delay, that is disabled
+ * by default, and is intended to be used for debugging client side ALUA code.
+ */
+#define ALUA_DEFAULT_TRANS_DELAY_MSECS			0
+#define ALUA_MAX_TRANS_DELAY_MSECS			30000 /* 30 seconds */
+
+
+extern se_global_t *se_global;
+
+extern struct kmem_cache *t10_alua_lu_gp_cache;
+extern struct kmem_cache *t10_alua_lu_gp_mem_cache;
+extern struct kmem_cache *t10_alua_tg_pt_gp_cache;
+extern struct kmem_cache *t10_alua_tg_pt_gp_mem_cache;
+
+extern int core_scsi3_emulate_report_target_port_groups(struct se_cmd_s *);
+extern int core_scsi3_emulate_set_target_port_groups(struct se_cmd_s *);
+extern int core_alua_check_transition(int, int *);
+extern int core_alua_check_nonop_delay(struct se_cmd_s *);
+extern int core_alua_do_transition_tg_pt(struct t10_alua_tg_pt_gp_s *,
+				struct se_port_s *, struct se_node_acl_s *,
+				unsigned char *, int, int);
+extern int core_alua_do_port_transition(struct t10_alua_tg_pt_gp_s *,
+				struct se_device_s *, struct se_port_s *,
+				struct se_node_acl_s *, int, int);
+extern int core_alua_set_tg_pt_secondary_state(
+		struct t10_alua_tg_pt_gp_member_s *, se_port_t *, int, int);
+extern char *core_alua_dump_state(int);
+extern char *core_alua_dump_status(int);
+extern struct t10_alua_lu_gp_s *core_alua_allocate_lu_gp(const char *, int);
+extern int core_alua_set_lu_gp_id(struct t10_alua_lu_gp_s *, u16);
+extern struct t10_alua_lu_gp_member_s *core_alua_allocate_lu_gp_mem(
+					struct se_device_s *);
+extern void core_alua_free_lu_gp(struct t10_alua_lu_gp_s *);
+extern void core_alua_free_lu_gp_mem(struct se_device_s *);
+extern struct t10_alua_lu_gp_s *core_alua_get_lu_gp_by_name(const char *);
+extern void core_alua_put_lu_gp_from_name(struct t10_alua_lu_gp_s *);
+extern void __core_alua_attach_lu_gp_mem(struct t10_alua_lu_gp_member_s *,
+					struct t10_alua_lu_gp_s *);
+extern void __core_alua_drop_lu_gp_mem(struct t10_alua_lu_gp_member_s *,
+					struct t10_alua_lu_gp_s *);
+extern void core_alua_drop_lu_gp_dev(struct se_device_s *);
+extern struct t10_alua_tg_pt_gp_s *core_alua_allocate_tg_pt_gp(
+			struct se_subsystem_dev_s *, const char *, int);
+extern int core_alua_set_tg_pt_gp_id(struct t10_alua_tg_pt_gp_s *, u16);
+extern struct t10_alua_tg_pt_gp_member_s *core_alua_allocate_tg_pt_gp_mem(
+					struct se_port_s *);
+extern void core_alua_free_tg_pt_gp(struct t10_alua_tg_pt_gp_s *);
+extern void core_alua_free_tg_pt_gp_mem(struct se_port_s *);
+extern struct t10_alua_tg_pt_gp_s *core_alua_get_tg_pt_gp_by_name(
+				struct se_subsystem_dev_s *, const char *);
+extern void core_alua_put_tg_pt_gp_from_name(struct t10_alua_tg_pt_gp_s *);
+extern void __core_alua_attach_tg_pt_gp_mem(struct t10_alua_tg_pt_gp_member_s *,
+					struct t10_alua_tg_pt_gp_s *);
+extern void __core_alua_drop_tg_pt_gp_mem(struct t10_alua_tg_pt_gp_member_s *,
+					struct t10_alua_tg_pt_gp_s *);
+extern ssize_t core_alua_show_tg_pt_gp_info(struct se_port_s *, char *);
+extern ssize_t core_alua_store_tg_pt_gp_info(struct se_port_s *, const char *,
+						size_t);
+extern ssize_t core_alua_show_access_type(struct t10_alua_tg_pt_gp_s *, char *);
+extern ssize_t core_alua_store_access_type(struct t10_alua_tg_pt_gp_s *,
+					const char *, size_t);
+extern ssize_t core_alua_show_nonop_delay_msecs(struct t10_alua_tg_pt_gp_s *,
+						char *);
+extern ssize_t core_alua_store_nonop_delay_msecs(struct t10_alua_tg_pt_gp_s *,
+					const char *, size_t);
+extern ssize_t core_alua_show_trans_delay_msecs(struct t10_alua_tg_pt_gp_s *,
+					char *);
+extern ssize_t core_alua_store_trans_delay_msecs(struct t10_alua_tg_pt_gp_s *,
+					const char *, size_t);
+extern ssize_t core_alua_show_preferred_bit(struct t10_alua_tg_pt_gp_s *,
+					char *);
+extern ssize_t core_alua_store_preferred_bit(struct t10_alua_tg_pt_gp_s *,
+					const char *, size_t);
+extern ssize_t core_alua_show_offline_bit(struct se_lun_s *, char *);
+extern ssize_t core_alua_store_offline_bit(struct se_lun_s *, const char *,
+					size_t);
+extern ssize_t core_alua_show_secondary_status(struct se_lun_s *, char *);
+extern ssize_t core_alua_store_secondary_status(struct se_lun_s *,
+					const char *, size_t);
+extern ssize_t core_alua_show_secondary_write_metadata(struct se_lun_s *,
+					char *);
+extern ssize_t core_alua_store_secondary_write_metadata(struct se_lun_s *,
+					const char *, size_t);
+extern int core_setup_alua(struct se_device_s *);
+
+#endif /* TARGET_CORE_ALUA_H */


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