[RFC PATCH 9/19] Target_Core_Mod SPC-3 Persistent Reservations

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This patch adds support for exhaustive support for SPC-3 compliant persistent reservations
for target_core_mod/ConfigFS storage objects.

Signed-off-by: Nicholas A. Bellinger <nab@xxxxxxxxxxxxxxx>

diff --git a/drivers/target/target_core_pr.c b/drivers/target/target_core_pr.c
new file mode 100644
index 0000000..9731ec3
--- /dev/null
+++ b/drivers/target/target_core_pr.c
@@ -0,0 +1,2207 @@
+/*******************************************************************************
+ * Filename:  target_core_pr.c
+ *
+ * This file contains SPC-3 compliant persistent reservations and
+ * legacy SPC-2 reservations.
+ *
+ * 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_PR_C
+
+#include <linux/version.h>
+#include <linux/slab.h>
+#include <linux/spinlock.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_tmr.h>
+#include <target/target_core_transport.h>
+#include <target/target_core_pr.h>
+#include <target/target_core_ua.h>
+#include <target/target_core_transport_plugin.h>
+#include <target/target_core_fabric_ops.h>
+#include <target/target_core_configfs.h>
+
+#undef TARGET_CORE_PR_C
+
+static void __core_scsi3_complete_pro_release(se_device_t *, se_node_acl_t *,
+			t10_pr_registration_t *g, int);
+
+int core_scsi2_reservation_seq_non_holder(
+	se_cmd_t *cmd,
+	unsigned char *cdb,
+	u32 pr_reg_type)
+{
+	switch (cdb[0]) {
+	case INQUIRY:
+	case RELEASE:
+	case RELEASE_10:
+		return 0;
+	default:
+		return 1;
+	}
+
+	return 1;
+}
+
+int core_scsi2_reservation_check(se_cmd_t *cmd, u32 *pr_reg_type)
+{
+	se_device_t *dev = cmd->se_dev;
+	se_session_t *sess = cmd->se_sess;
+	int ret;
+
+	if (!(sess))
+		return 0;
+
+	spin_lock(&dev->dev_reservation_lock);
+	if (!dev->dev_reserved_node_acl || !sess) {
+		spin_unlock(&dev->dev_reservation_lock);
+		return 0;
+	}
+	ret = (dev->dev_reserved_node_acl != sess->se_node_acl) ? -1 : 0;
+	spin_unlock(&dev->dev_reservation_lock);
+
+	return ret;
+}
+EXPORT_SYMBOL(core_scsi2_reservation_check);
+
+int core_scsi2_reservation_release(se_cmd_t *cmd)
+{
+	se_device_t *dev = cmd->se_dev;
+	se_session_t *sess = cmd->se_sess;
+	se_portal_group_t *tpg = sess->se_tpg;
+
+	if (!(sess) || !(tpg))
+		return 0;
+
+	spin_lock(&dev->dev_reservation_lock);
+	if (!dev->dev_reserved_node_acl || !sess) {
+		spin_unlock(&dev->dev_reservation_lock);
+		return 0;
+	}
+
+	if (dev->dev_reserved_node_acl != sess->se_node_acl) {
+		spin_unlock(&dev->dev_reservation_lock);
+		return 0;
+	}
+	dev->dev_reserved_node_acl = NULL;
+	printk(KERN_INFO "SCSI-2 Released reservation for %s LUN: %u ->"
+		" MAPPED LUN: %u for %s\n", TPG_TFO(tpg)->get_fabric_name(),
+		SE_LUN(cmd)->unpacked_lun, cmd->se_deve->mapped_lun,
+		sess->se_node_acl->initiatorname);
+	spin_unlock(&dev->dev_reservation_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(core_scsi2_reservation_release);
+
+int core_scsi2_reservation_reserve(se_cmd_t *cmd)
+{
+	se_device_t *dev = cmd->se_dev;
+	se_session_t *sess = cmd->se_sess;
+	se_portal_group_t *tpg = sess->se_tpg;
+
+	if ((T_TASK(cmd)->t_task_cdb[1] & 0x01) &&
+	    (T_TASK(cmd)->t_task_cdb[1] & 0x02)) {
+		printk(KERN_ERR "LongIO and Obselete Bits set, returning"
+				" ILLEGAL_REQUEST\n");
+		return -1;
+	}
+
+	/*
+	 * This is currently the case for target_core_mod passthrough se_cmd_t
+	 * ops
+	 */
+	if (!(sess) || !(tpg))
+		return 0;
+
+	spin_lock(&dev->dev_reservation_lock);
+	if (dev->dev_reserved_node_acl &&
+	   (dev->dev_reserved_node_acl != sess->se_node_acl)) {
+		printk(KERN_ERR "SCSI-2 RESERVATION CONFLIFT for %s fabric\n",
+			TPG_TFO(tpg)->get_fabric_name());
+		printk(KERN_ERR "Original reserver LUN: %u %s\n",
+			SE_LUN(cmd)->unpacked_lun,
+			dev->dev_reserved_node_acl->initiatorname);
+		printk(KERN_ERR "Current attempt - LUN: %u -> MAPPED LUN: %u"
+			" from %s \n", SE_LUN(cmd)->unpacked_lun,
+			cmd->se_deve->mapped_lun,
+			sess->se_node_acl->initiatorname);
+		spin_unlock(&dev->dev_reservation_lock);
+		return 1;
+	}
+
+	dev->dev_reserved_node_acl = sess->se_node_acl;
+	dev->dev_flags |= DF_SPC2_RESERVATIONS;
+	printk(KERN_INFO "SCSI-2 Reserved %s LUN: %u -> MAPPED LUN: %u"
+		" for %s\n", TPG_TFO(tpg)->get_fabric_name(),
+		SE_LUN(cmd)->unpacked_lun, cmd->se_deve->mapped_lun,
+		sess->se_node_acl->initiatorname);
+	spin_unlock(&dev->dev_reservation_lock);
+
+	return 0;
+}
+EXPORT_SYMBOL(core_scsi2_reservation_reserve);
+
+/*
+ * Begin SPC-3/SPC-4 Persistent Reservations emulation support
+ *
+ * This function is called by those initiator ports who are *NOT*
+ * the active PR reservation holder when a reservation is present.
+ */
+static int core_scsi3_pr_seq_non_holder(
+	se_cmd_t *cmd,
+	unsigned char *cdb,
+	u32 pr_reg_type)
+{
+	se_dev_entry_t *se_deve;
+	se_session_t *se_sess = SE_SESS(cmd);
+	se_lun_t *se_lun = SE_LUN(cmd);
+	int other_cdb = 0;
+	int registered_nexus = 0, ret = 1; /* Conflict by default */
+	int all_reg = 0, reg_only = 0; /* ALL_REG, REG_ONLY */
+	int we = 0; /* Write Exclusive */
+	int legacy = 0; /* Act like a legacy device and return
+			 * RESERVATION CONFLICT on some CDBs */
+
+	se_deve = &se_sess->se_node_acl->device_list[se_lun->unpacked_lun];
+
+	switch (pr_reg_type) {
+	case PR_TYPE_WRITE_EXCLUSIVE:
+		we = 1;
+	case PR_TYPE_EXCLUSIVE_ACCESS:
+		/*
+		 * Some commands are only allowed for the persistent reservation
+		 * holder.
+		 */
+		if (se_deve->deve_flags & DEF_PR_REGISTERED)
+			registered_nexus = 1;
+		break;
+	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
+		we = 1;
+	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
+		/*
+		 * Some commands are only allowed for registered I_T Nexuses.
+		 */
+		reg_only = 1;
+		if (se_deve->deve_flags & DEF_PR_REGISTERED)
+			registered_nexus = 1;
+		break;
+	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
+		we = 1;
+	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
+		/*
+		 * Each registered I_T Nexus is a reservation holder.
+		 */
+		all_reg = 1;
+		if (se_deve->deve_flags & DEF_PR_REGISTERED)
+			registered_nexus = 1;
+		break;
+	default:
+		return -1;
+	}
+	/*
+	 * Referenced from spc4r17 table 45 for *NON* PR holder access
+	 */
+	switch (cdb[0]) {
+	case SECURITY_PROTOCOL_IN:
+		if (registered_nexus)
+			return 0;
+		ret = (we) ? 0 : 1;
+		break;
+	case MODE_SENSE:
+	case MODE_SENSE_10:
+	case READ_ATTRIBUTE:
+	case READ_BUFFER:
+	case RECEIVE_DIAGNOSTIC:
+		if (legacy) {
+			ret = 1;
+			break;
+		}
+		if (registered_nexus) {
+			ret = 0;
+			break;
+		}
+		ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
+		break;
+	case PERSISTENT_RESERVE_OUT:
+		/*
+		 * This follows PERSISTENT_RESERVE_OUT service actions that
+		 * are allowed in the presence of various reservations.
+		 * See spc4r17, table 46
+		 */
+		switch (cdb[1] & 0x1f) {
+		case PRO_CLEAR:
+		case PRO_PREEMPT:
+		case PRO_PREEMPT_AND_ABORT:
+			ret = (registered_nexus) ? 0 : 1;
+			break;
+		case PRO_REGISTER:
+		case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
+			ret = 0;
+			break;
+		case PRO_REGISTER_AND_MOVE:
+		case PRO_RESERVE:
+			ret = 1;
+			break;
+		case PRO_RELEASE:
+			ret = (registered_nexus) ? 0 : 1;
+			break;
+		default:
+			printk(KERN_ERR "Unknown PERSISTENT_RESERVE_OUT service"
+				" action: 0x%02x\n", cdb[1] & 0x1f);
+			return -1;
+		}
+		break;
+	/* FIXME PR + legacy RELEASE + RESERVE */
+	case RELEASE:
+	case RELEASE_10:
+		ret = 1; /* Conflict */
+		break;
+	case RESERVE:
+	case RESERVE_10:
+		ret = 1; /* Conflict */
+		break;
+	case TEST_UNIT_READY:
+		ret = (legacy) ? 1 : 0; /* Conflict for legacy */
+		break;
+	case MAINTENANCE_IN:
+		switch (cdb[1] & 0x1f) {
+		case MI_MANAGEMENT_PROTOCOL_IN:
+			if (registered_nexus) {
+				ret = 0;
+				break;
+			}
+			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
+			break;
+		case MI_REPORT_SUPPORTED_OPERATION_CODES:
+		case MI_REPORT_SUPPORTED_TASK_MANAGEMENT_FUNCTIONS:
+			if (legacy) {
+				ret = 1;
+				break;
+			}
+			if (registered_nexus) {
+				ret = 0;
+				break;
+			}
+			ret = (we) ? 0 : 1; /* Allowed Write Exclusive */
+			break;
+		case MI_REPORT_ALIASES:
+		case MI_REPORT_IDENTIFYING_INFORMATION:
+		case MI_REPORT_PRIORITY:
+		case MI_REPORT_TARGET_PGS:
+		case MI_REPORT_TIMESTAMP:
+			ret = 0; /* Allowed */
+			break;
+		default:
+			printk(KERN_ERR "Unknown MI Service Action: 0x%02x\n",
+				(cdb[1] & 0x1f));
+			return -1;
+		}
+		break;
+	case ACCESS_CONTROL_IN:
+	case ACCESS_CONTROL_OUT:
+	case INQUIRY:
+	case LOG_SENSE:
+	case READ_MEDIA_SERIAL_NUMBER:
+	case REPORT_LUNS:
+	case REQUEST_SENSE:
+		ret = 0; /*/ Allowed CDBs */
+		break;
+	default:
+		other_cdb = 1;
+		break;
+	}
+	/*
+	 * Case where the CDB is explictly allowed in the above switch
+	 * statement.
+	 */
+	if (!(ret) && !(other_cdb)) {
+#if 0
+		printk(KERN_INFO "Allowing explict CDB: 0x%02x for %s"
+			" reservation holder\n", cdb[0],
+			core_scsi3_pr_dump_type(pr_reg_type));
+#endif
+		return ret;
+	}
+	/*
+	 * Check if write exclusive initiator ports *NOT* holding the
+	 * WRITE_EXCLUSIVE_* reservation.
+	 */
+	if ((we) && !(registered_nexus)) {
+		if ((cmd->data_direction == SE_DIRECTION_WRITE) ||
+		    (cmd->data_direction == SE_DIRECTION_BIDI)) {
+			/*
+			 * Conflict for write exclusive
+			 */
+			printk(KERN_INFO "%s Conflict for unregistered nexus"
+				" %s CDB: 0x%02x to %s reservation\n",
+				transport_dump_cmd_direction(cmd),
+				se_sess->se_node_acl->initiatorname, cdb[0],
+				core_scsi3_pr_dump_type(pr_reg_type));
+			return 1;
+		} else {
+			/*
+			 * Allow non WRITE CDBs for all Write Exclusive
+			 * PR TYPEs to pass for registered and
+			 * non-registered_nexuxes NOT holding the reservation.
+			 *
+			 * We only make noise for the unregisterd nexuses,
+			 * as we expect registered non-reservation holding
+			 * nexuses to issue CDBs.
+			 */
+#if 0
+			if (!(registered_nexus)) {
+				printk(KERN_INFO "Allowing implict CDB: 0x%02x"
+					" for %s reservation on unregistered"
+					" nexus\n", cdb[0],
+					core_scsi3_pr_dump_type(pr_reg_type));
+			}
+#endif
+			return 0;
+		}
+	} else if ((reg_only) || (all_reg)) {
+		if (registered_nexus) {
+			/*
+			 * For PR_*_REG_ONLY and PR_*_ALL_REG reservations,
+			 * allow commands from registered nexuses.
+			 */
+#if 0
+			printk(KERN_INFO "Allowing implict CDB: 0x%02x for %s"
+				" reservation\n", cdb[0],
+				core_scsi3_pr_dump_type(pr_reg_type));
+#endif
+			return 0;
+		}
+	}
+	printk(KERN_INFO "%s Conflict for %sregistered nexus %s CDB: 0x%2x"
+		" for %s reservation\n", transport_dump_cmd_direction(cmd),
+		(registered_nexus) ? "" : "un",
+		se_sess->se_node_acl->initiatorname, cdb[0],
+		core_scsi3_pr_dump_type(pr_reg_type));
+
+	return 1; /* Conflict by default */
+}
+
+static u32 core_scsi3_pr_generation(se_device_t *dev)
+{
+	se_subsystem_dev_t *su_dev = SU_DEV(dev);
+	u32 prg;
+	/*
+	 * PRGeneration field shall contain the value of a 32-bit wrapping
+	 * counter mainted by the device server.
+	 *
+	 * Note that this is done regardless of Active Persist across
+	 * Target PowerLoss (APTPL)
+	 *
+	 * See spc4r17 section 6.3.12 READ_KEYS service action
+	 */
+	spin_lock(&dev->dev_reservation_lock);
+	prg = T10_RES(su_dev)->pr_generation++;
+	spin_unlock(&dev->dev_reservation_lock);
+
+	return prg;
+}
+
+static int core_scsi3_pr_reservation_check(
+	se_cmd_t *cmd,
+	u32 *pr_reg_type)
+{
+	se_device_t *dev = cmd->se_dev;
+	se_session_t *sess = cmd->se_sess;
+	int ret;
+
+	if (!(sess))
+		return 0;
+
+	spin_lock(&dev->dev_reservation_lock);
+	if (!(dev->dev_pr_res_holder)) {
+		spin_unlock(&dev->dev_reservation_lock);
+		return 0;
+	}
+	*pr_reg_type = dev->dev_pr_res_holder->pr_res_type;
+	cmd->pr_res_key = dev->dev_pr_res_holder->pr_res_key;
+	ret = (dev->dev_pr_res_holder->pr_reg_nacl != sess->se_node_acl) ?
+		-1 : 0;
+	spin_unlock(&dev->dev_reservation_lock);
+
+	return ret;
+}
+
+static int core_scsi3_legacy_reserve(se_cmd_t *cmd)
+{
+	/*
+	 * FIXME: See spc4r17 Section 5.7.3
+	 */
+	return core_scsi2_reservation_reserve(cmd);
+}
+
+static int core_scsi3_legacy_release(se_cmd_t *cmd)
+{
+	/*
+	 * FIXME: See spc4r17 Section 5.7.3
+	 */
+	return core_scsi2_reservation_release(cmd);
+}
+
+static int core_scsi3_alloc_registration(
+	se_device_t *dev,
+	se_node_acl_t *nacl,
+	se_dev_entry_t *deve,
+	u64 sa_res_key,
+	int all_tg_pt,
+	int ignore_key)
+{
+	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
+	t10_reservation_template_t *pr_tmpl = &SU_DEV(dev)->t10_reservation;
+	t10_pr_registration_t *pr_reg;
+
+	pr_reg = kmem_cache_zalloc(t10_pr_reg_cache, GFP_KERNEL);
+	if (!(pr_reg)) {
+		printk(KERN_ERR "Unable to allocate t10_pr_registration_t\n");
+		return -1;
+	}
+
+	INIT_LIST_HEAD(&pr_reg->pr_reg_list);
+	INIT_LIST_HEAD(&pr_reg->pr_reg_abort_list);
+	atomic_set(&pr_reg->pr_res_holders, 0);
+	pr_reg->pr_reg_nacl = nacl;
+	pr_reg->pr_reg_deve = deve;
+	pr_reg->pr_res_mapped_lun = deve->mapped_lun;
+	pr_reg->pr_res_key = sa_res_key;
+	pr_reg->pr_reg_all_tg_pt = all_tg_pt;
+	pr_reg->pr_reg_tg_pt_lun = deve->se_lun;
+
+	/*
+	 * Increment PRgeneration counter for se_device_t upon a successful
+	 * REGISTER, see spc4r17 section 6.3.2 READ_KEYS service action
+	 */
+	pr_reg->pr_res_generation = core_scsi3_pr_generation(dev);
+
+	spin_lock(&pr_tmpl->registration_lock);
+	list_add_tail(&pr_reg->pr_reg_list, &pr_tmpl->registration_list);
+	deve->deve_flags |= DEF_PR_REGISTERED;
+	deve->pr_res_key = sa_res_key;
+
+	printk(KERN_INFO "SPC-3 PR [%s] Service Action: REGISTER%s Initiator"
+		" Node: %s\n", tfo->get_fabric_name(), (ignore_key) ?
+		"_AND_IGNORE_EXISTING_KEY" : "", nacl->initiatorname);
+	printk(KERN_INFO "SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
+		" Port(s)\n",  tfo->get_fabric_name(),
+		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
+		TRANSPORT(dev)->name);
+	printk(KERN_INFO "SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
+		" 0x%08x\n", tfo->get_fabric_name(), pr_reg->pr_res_key,
+		pr_reg->pr_res_generation);
+	spin_unlock(&pr_tmpl->registration_lock);
+
+	return 0;
+}
+
+static t10_pr_registration_t *core_scsi3_locate_pr_reg(
+	se_device_t *dev,
+	se_node_acl_t *nacl)
+{
+	t10_reservation_template_t *pr_tmpl = &SU_DEV(dev)->t10_reservation;
+	t10_pr_registration_t *pr_reg, *pr_reg_tmp;
+
+	spin_lock(&pr_tmpl->registration_lock);
+	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
+			&pr_tmpl->registration_list, pr_reg_list) {
+		if (pr_reg->pr_reg_nacl == nacl) {
+			atomic_inc(&pr_reg->pr_res_holders);
+			smp_mb__after_atomic_inc();
+			spin_unlock(&pr_tmpl->registration_lock);
+			return pr_reg;
+		}
+	}
+	spin_unlock(&pr_tmpl->registration_lock);
+
+	return NULL;
+}
+
+static void core_scsi3_put_pr_reg(t10_pr_registration_t *pr_reg)
+{
+	atomic_dec(&pr_reg->pr_res_holders);
+	smp_mb__after_atomic_dec();
+}
+
+static int core_scsi3_check_implict_release(
+	se_device_t *dev,
+	t10_pr_registration_t *pr_reg)
+{
+	se_node_acl_t *nacl = pr_reg->pr_reg_nacl;
+	t10_pr_registration_t *pr_res_holder;
+	int ret = 0;
+
+	spin_lock(&dev->dev_reservation_lock);
+	pr_res_holder = dev->dev_pr_res_holder;
+	if ((pr_res_holder != NULL) && (pr_res_holder == pr_reg)) {
+		/*
+		 * Perform an implict RELEASE if the registration that
+		 * is being released is holding the reservation.
+		 *
+		 * From spc4r17, section 5.7.11.1:
+		 *
+		 * e) If the I_T nexus is the persistent reservation holder
+		 *    and the persistent reservation is not an all registrants
+		 *    type, then a PERSISTENT RESERVE OUT command with REGISTER
+		 *    service action or REGISTER AND  IGNORE EXISTING KEY
+		 *    service action with the SERVICE ACTION RESERVATION KEY
+		 *    field set to zero (see 5.7.11.3).
+		 */
+		__core_scsi3_complete_pro_release(dev, nacl, pr_reg, 0);
+		ret = 1;
+/* #warning FIXME: All Registrants, only release reservation when last registration is freed. */
+	}
+	spin_unlock(&dev->dev_reservation_lock);
+
+	return ret;
+}
+
+/*
+ * Called with t10_reservation_template_t->registration_lock held.
+ */
+static void __core_scsi3_free_registration(
+	se_device_t *dev,
+	t10_pr_registration_t *pr_reg,
+	struct list_head *preempt_and_abort_list,
+	int dec_holders)
+{
+	struct target_core_fabric_ops *tfo =
+			pr_reg->pr_reg_nacl->se_tpg->se_tpg_tfo;
+	t10_reservation_template_t *pr_tmpl = &SU_DEV(dev)->t10_reservation;
+
+	pr_reg->pr_reg_deve->deve_flags &= ~DEF_PR_REGISTERED;
+	pr_reg->pr_reg_deve->pr_res_key = 0;
+	list_del(&pr_reg->pr_reg_list);
+	/*
+	 * Caller accessing *pr_reg using core_scsi3_locate_pr_reg(),
+	 * so call core_scsi3_put_pr_reg() to decrement our reference.
+	 */
+	if (dec_holders)
+		core_scsi3_put_pr_reg(pr_reg);
+	/*
+	 * Wait until all reference from any other I_T nexuses for this
+	 * *pr_reg have been released.  Because list_del() is called above,
+	 * the last core_scsi3_put_pr_reg(pr_reg) will release this reference
+	 * count back to zero, and we release *pr_reg.
+	 */
+	while (atomic_read(&pr_reg->pr_res_holders) != 0) {
+		spin_unlock(&pr_tmpl->registration_lock);
+		printk("SPC-3 PR [%s] waiting for pr_res_holders\n",
+				tfo->get_fabric_name());
+		msleep(10);
+		spin_lock(&pr_tmpl->registration_lock);
+	}
+
+	printk(KERN_INFO "SPC-3 PR [%s] Service Action: UNREGISTER Initiator"
+		" Node: %s\n", tfo->get_fabric_name(),
+		pr_reg->pr_reg_nacl->initiatorname);
+	printk(KERN_INFO "SPC-3 PR [%s] for %s TCM Subsystem %s Object Target"
+		" Port(s)\n", tfo->get_fabric_name(),
+		(pr_reg->pr_reg_all_tg_pt) ? "ALL" : "SINGLE",
+		TRANSPORT(dev)->name);
+	printk(KERN_INFO "SPC-3 PR [%s] SA Res Key: 0x%016Lx PRgeneration:"
+		" 0x%08x\n", tfo->get_fabric_name(), pr_reg->pr_res_key,
+		pr_reg->pr_res_generation);
+
+	if (!(preempt_and_abort_list)) {
+		pr_reg->pr_reg_deve = NULL;
+		pr_reg->pr_reg_nacl = NULL;
+		kmem_cache_free(t10_pr_reg_cache, pr_reg);
+		return;
+	}
+	/*
+	 * For PREEMPT_AND_ABORT, the list of *pr_reg in preempt_and_abort_list
+	 * are released once the ABORT_TASK_SET has completed..
+	 */
+	list_add_tail(&pr_reg->pr_reg_abort_list, preempt_and_abort_list);
+}
+
+void core_scsi3_free_pr_reg_from_nacl(
+	se_device_t *dev,
+	se_node_acl_t *nacl)
+{
+	t10_reservation_template_t *pr_tmpl = &SU_DEV(dev)->t10_reservation;
+	t10_pr_registration_t *pr_reg, *pr_reg_tmp, *pr_res_holder;
+	/*
+	 * If the passed se_node_acl matches the reservation holder,
+	 * release the reservation.
+	 */
+	spin_lock(&dev->dev_reservation_lock);
+	pr_res_holder = dev->dev_pr_res_holder;
+	if ((pr_res_holder != NULL) &&
+	    (pr_res_holder->pr_reg_nacl == nacl))
+		__core_scsi3_complete_pro_release(dev, nacl, pr_res_holder, 0);
+	spin_unlock(&dev->dev_reservation_lock);
+	/*
+	 * Release any registration associated with the se_node_acl_t.
+	 */
+	spin_lock(&pr_tmpl->registration_lock);
+	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
+			&pr_tmpl->registration_list, pr_reg_list) {
+
+		if (pr_reg->pr_reg_nacl != nacl)
+			continue;
+
+		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
+	}
+	spin_unlock(&pr_tmpl->registration_lock);
+}
+
+void core_scsi3_free_all_registrations(
+	se_device_t *dev)
+{
+	t10_reservation_template_t *pr_tmpl = &SU_DEV(dev)->t10_reservation;
+	t10_pr_registration_t *pr_reg, *pr_reg_tmp, *pr_res_holder;
+
+	spin_lock(&dev->dev_reservation_lock);
+	pr_res_holder = dev->dev_pr_res_holder;
+	if (pr_res_holder != NULL) {
+		se_node_acl_t *pr_res_nacl = pr_res_holder->pr_reg_nacl;
+		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
+				pr_res_holder, 0);
+	}
+	spin_unlock(&dev->dev_reservation_lock);
+
+	spin_lock(&pr_tmpl->registration_lock);
+	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
+			&pr_tmpl->registration_list, pr_reg_list) {
+
+		__core_scsi3_free_registration(dev, pr_reg, NULL, 0);
+	}
+	spin_unlock(&pr_tmpl->registration_lock);
+}
+
+static int core_scsi3_emulate_pro_register(
+	se_cmd_t *cmd,
+	u64 res_key,
+	u64 sa_res_key,
+	int aptpl,
+	int all_tg_pt,
+	int spec_i_pt,
+	int ignore_key)
+{
+	se_session_t *se_sess = SE_SESS(cmd);
+	se_device_t *dev = SE_DEV(cmd);
+	se_dev_entry_t *se_deve;
+	se_lun_t *se_lun = SE_LUN(cmd);
+	se_portal_group_t *se_tpg;
+	t10_pr_registration_t *pr_reg, *pr_reg_p;
+	t10_reservation_template_t *pr_tmpl = &SU_DEV(dev)->t10_reservation;
+	int pr_holder = 0, ret = 0, type;
+
+	if (!(se_sess) || !(se_lun)) {
+		printk(KERN_ERR "SPC-3 PR: se_sess || se_lun_t is NULL!\n");
+		return PYX_TRANSPORT_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+	}
+	se_tpg = se_sess->se_tpg;
+	se_deve = &se_sess->se_node_acl->device_list[se_lun->unpacked_lun];
+
+	if (aptpl) {
+		printk(KERN_INFO "Activate Persistence across Target Power"
+			" Loss = 1 not implemented yet\n");
+		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
+	}
+	/*
+	 * Follow logic from spc4r17 Section 5.7.7, Register Behaviors Table 47
+	 */
+	if (!(se_deve->deve_flags & DEF_PR_REGISTERED)) {
+		if (res_key) {
+			printk(KERN_WARNING "SPC-3 PR: Reservation Key non-zero"
+				" for SA REGISTER, returning CONFLICT\n");
+			return PYX_TRANSPORT_RESERVATION_CONFLICT;
+		}
+		/*
+		 * Do nothing but return GOOD status.
+		 */
+		if (!(sa_res_key))
+			return PYX_TRANSPORT_SENT_TO_TRANSPORT;
+
+		if (!(spec_i_pt)) {
+			/*
+			 * Perform the Service Action REGISTER on the Initiator
+			 * Port Endpoint that the PRO was received from on the
+			 * Logical Unit of the SCSI device server.
+			 */
+			ret = core_scsi3_alloc_registration(SE_DEV(cmd),
+					se_sess->se_node_acl, se_deve,
+					sa_res_key, all_tg_pt, ignore_key);
+			if (ret != 0) {
+				printk(KERN_ERR "Unable to allocate"
+					" t10_pr_registration_t\n");
+				return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
+			}
+		} else {
+			/*
+			 * FIXME: Extract SCSI TransportID from Parameter list
+			 * and loop through parameter list while calling logic
+			 * from of core_scsi3_alloc_registration()
+			 */
+			printk("Specify Initiator Ports (SPEC_I_PT) = 1 not"
+					" implemented yet\n");
+			return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
+		}
+	} else {
+		/*
+		 * Locate the existing *pr_reg via se_node_acl_t pointers
+		 */
+		pr_reg = core_scsi3_locate_pr_reg(SE_DEV(cmd),
+				se_sess->se_node_acl);
+		if (!(pr_reg)) {
+			printk(KERN_ERR "SPC-3 PR: Unable to locate"
+				" PR_REGISTERED *pr_reg for REGISTER\n");
+			core_scsi3_put_pr_reg(pr_reg);
+			return PYX_TRANSPORT_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+		}
+		type = pr_reg->pr_res_type;
+
+		if (!(ignore_key)) {
+			if (res_key != pr_reg->pr_res_key) {
+				printk(KERN_ERR "SPC-3 PR REGISTER: Received"
+					" res_key: 0x%016Lx does not match"
+					" existing SA REGISTER res_key:"
+					" 0x%016Lx\n", res_key,
+					pr_reg->pr_res_key);
+				core_scsi3_put_pr_reg(pr_reg);
+				return PYX_TRANSPORT_RESERVATION_CONFLICT;
+			}
+		}
+		if (spec_i_pt) {
+			printk(KERN_ERR "SPC-3 PR UNREGISTER: SPEC_I_PT"
+				" set while sa_res_key=0\n");
+			core_scsi3_put_pr_reg(pr_reg);
+			return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
+		}
+		/*
+		 * sa_res_key=0 Unregister Reservation Key for registered I_T
+		 * Nexus sa_res_key=1 Change Reservation Key for registered I_T
+		 * Nexus.
+		 */
+		if (!(sa_res_key)) {
+			pr_holder = core_scsi3_check_implict_release(
+					SE_DEV(cmd), pr_reg);
+
+			spin_lock(&pr_tmpl->registration_lock);
+			/*
+			 * Release the calling I_T Nexus registration now..
+			 */
+			__core_scsi3_free_registration(SE_DEV(cmd), pr_reg,
+							NULL, 1);
+			/*
+			 * From spc4r17, section 5.7.11.3 Unregistering
+			 *
+			 * If the persistent reservation is a registrants only
+			 * type, the device server shall establish a unit
+			 * attention condition for the initiator port associated
+			 * with every registered I_T nexus except for the I_T
+			 * nexus on which the PERSISTENT RESERVE OUT command was
+			 * received, with the additional sense code set to
+			 * RESERVATIONS RELEASED.
+			 */
+			if (pr_holder &&
+			   ((type == PR_TYPE_WRITE_EXCLUSIVE_REGONLY) ||
+			    (type == PR_TYPE_EXCLUSIVE_ACCESS_REGONLY))) {
+				list_for_each_entry(pr_reg_p,
+						&pr_tmpl->registration_list,
+						pr_reg_list) {
+
+					core_scsi3_ua_allocate(
+						pr_reg_p->pr_reg_nacl,
+						pr_reg_p->pr_res_mapped_lun,
+						0x2A,
+						ASCQ_2AH_RESERVATIONS_RELEASED);
+				}
+			}
+			spin_unlock(&pr_tmpl->registration_lock);
+		} else {
+			/*
+			 * Increment PRgeneration counter for se_device_t"
+			 * upon a successful REGISTER, see spc4r17 section 6.3.2
+			 * READ_KEYS service action.
+			 */
+			pr_reg->pr_res_generation = core_scsi3_pr_generation(
+							SE_DEV(cmd));
+			pr_reg->pr_res_key = sa_res_key;
+			printk("SPC-3 PR [%s] REGISTER%s: Changed Reservation"
+				" Key for %s to: 0x%016Lx PRgeneration:"
+				" 0x%08x\n", CMD_TFO(cmd)->get_fabric_name(),
+				(ignore_key) ? "_AND_IGNORE_EXISTING_KEY" : "",
+				pr_reg->pr_reg_nacl->initiatorname,
+				pr_reg->pr_res_key, pr_reg->pr_res_generation);
+
+			core_scsi3_put_pr_reg(pr_reg);
+		}
+	}
+
+	return 0;
+}
+
+unsigned char *core_scsi3_pr_dump_type(int type)
+{
+	switch (type) {
+	case PR_TYPE_WRITE_EXCLUSIVE:
+		return "Write Exclusive Access";
+	case PR_TYPE_EXCLUSIVE_ACCESS:
+		return "Exclusive Access";
+	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
+		return "Write Exclusive Access, Registrants Only";
+	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
+		return "Exclusive Access, Registrants Only";
+	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
+		return "Write Exclusive Access, All Registrants";
+	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
+		return "Exclusive Access, All Registrants";
+	default:
+		break;
+	}
+
+	return "Unknown SPC-3 PR Type";
+}
+
+static int core_scsi3_pro_reserve(
+	se_cmd_t *cmd,
+	se_device_t *dev,
+	int type,
+	int scope,
+	u64 res_key)
+{
+	se_session_t *se_sess = SE_SESS(cmd);
+	se_dev_entry_t *se_deve;
+	se_lun_t *se_lun = SE_LUN(cmd);
+	se_portal_group_t *se_tpg;
+	t10_pr_registration_t *pr_reg, *pr_res_holder;
+
+	if (!(se_sess) || !(se_lun)) {
+		printk(KERN_ERR "SPC-3 PR: se_sess || se_lun_t is NULL!\n");
+		return PYX_TRANSPORT_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+	}
+	se_tpg = se_sess->se_tpg;
+	se_deve = &se_sess->se_node_acl->device_list[se_lun->unpacked_lun];
+	/*
+	 * Locate the existing *pr_reg via se_node_acl_t pointers
+	 */
+	pr_reg = core_scsi3_locate_pr_reg(SE_DEV(cmd), se_sess->se_node_acl);
+	if (!(pr_reg)) {
+		printk(KERN_ERR "SPC-3 PR: Unable to locate"
+			" PR_REGISTERED *pr_reg for RESERVE\n");
+		return PYX_TRANSPORT_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+	}
+	/*
+	 * For a given ALL_TG_PT=0 PR registration, a recevied PR reserve must
+	 * be on the same matching se_portal_group_t + se_lun_t.
+	 */
+	if (!(pr_reg->pr_reg_all_tg_pt) &&
+	     (pr_reg->pr_reg_tg_pt_lun != se_lun)) {
+		printk(KERN_ERR "SPC-3 PR: Unable to handle RESERVE because"
+			" ALL_TG_PT=0 and RESERVE was not received on same"
+			" target port as REGISTER\n");
+		core_scsi3_put_pr_reg(pr_reg);
+		return PYX_TRANSPORT_RESERVATION_CONFLICT;
+	}
+	/*
+	 * From spc4r17 Section 5.7.9: Reserving:
+	 *
+	 * An application client creates a persistent reservation by issuing
+	 * a PERSISTENT RESERVE OUT command with RESERVE service action through
+	 * a registered I_T nexus with the following parameters:
+	 *    a) RESERVATION KEY set to the value of the reservation key that is
+	 * 	 registered with the logical unit for the I_T nexus; and
+	 */
+	if (res_key != pr_reg->pr_res_key) {
+		printk(KERN_ERR "SPC-3 PR RESERVE: Received res_key: 0x%016Lx"
+			" does not match existing SA REGISTER res_key:"
+			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
+		core_scsi3_put_pr_reg(pr_reg);
+		return PYX_TRANSPORT_RESERVATION_CONFLICT;
+	}
+	/*
+	 * From spc4r17 Section 5.7.9: Reserving:
+	 *
+	 * From above:
+	 *  b) TYPE field and SCOPE field set to the persistent reservation
+	 *     being created.
+	 *
+	 * Only one persistent reservation is allowed at a time per logical unit
+	 * and that persistent reservation has a scope of LU_SCOPE.
+	 */
+	if (scope != PR_SCOPE_LU_SCOPE) {
+		printk(KERN_ERR "SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
+		core_scsi3_put_pr_reg(pr_reg);
+		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
+	}
+	/*
+	 * See if we have an existing PR reservation holder pointer at
+	 * se_device_t->dev_pr_res_holder in the form t10_pr_registration_t
+	 * *pr_res_holder.
+	 */
+	spin_lock(&dev->dev_reservation_lock);
+	pr_res_holder = dev->dev_pr_res_holder;
+	if ((pr_res_holder)) {
+		/*
+		 * From spc4r17 Section 5.7.9: Reserving:
+		 *
+		 * If the device server receives a PERSISTENT RESERVE OUT
+		 * command from an I_T nexus other than a persistent reservation
+		 * holder (see 5.7.10) that attempts to create a persistent
+		 * reservation when a persistent reservation already exists for
+		 * the logical unit, then the command shall be completed with
+		 * RESERVATION CONFLICT status.
+		 */
+		if (pr_res_holder != pr_reg) {
+			se_node_acl_t *pr_res_nacl = pr_res_holder->pr_reg_nacl;
+			printk(KERN_ERR "SPC-3 PR: Attempted RESERVE from"
+				" [%s]: %s while reservation already held by"
+				" [%s]: %s, returning RESERVATION_CONFLICT\n",
+				CMD_TFO(cmd)->get_fabric_name(),
+				se_sess->se_node_acl->initiatorname,
+				TPG_TFO(pr_res_nacl->se_tpg)->get_fabric_name(),
+				pr_res_holder->pr_reg_nacl->initiatorname);
+
+			spin_unlock(&dev->dev_reservation_lock);
+			core_scsi3_put_pr_reg(pr_reg);
+			return PYX_TRANSPORT_RESERVATION_CONFLICT;
+		}
+		/*
+		 * From spc4r17 Section 5.7.9: Reserving:
+		 *
+		 * If a persistent reservation holder attempts to modify the
+		 * type or scope of an existing persistent reservation, the
+		 * command shall be completed with RESERVATION CONFLICT status.
+		 */
+		if ((pr_res_holder->pr_res_type != type) ||
+		    (pr_res_holder->pr_res_scope != scope)) {
+			se_node_acl_t *pr_res_nacl = pr_res_holder->pr_reg_nacl;
+			printk(KERN_ERR "SPC-3 PR: Attempted RESERVE from"
+				" [%s]: %s trying to change TYPE and/or SCOPE,"
+				" while reservation already held by [%s]: %s,"
+				" returning RESERVATION_CONFLICT\n",
+				CMD_TFO(cmd)->get_fabric_name(),
+				se_sess->se_node_acl->initiatorname,
+				TPG_TFO(pr_res_nacl->se_tpg)->get_fabric_name(),
+				pr_res_holder->pr_reg_nacl->initiatorname);
+
+			spin_unlock(&dev->dev_reservation_lock);
+			core_scsi3_put_pr_reg(pr_reg);
+			return PYX_TRANSPORT_RESERVATION_CONFLICT;
+		}
+		/*
+		 * From spc4r17 Section 5.7.9: Reserving:
+		 *
+		 * If the device server receives a PERSISTENT RESERVE OUT
+		 * command with RESERVE service action where the TYPE field and
+		 * the SCOPE field contain the same values as the existing type
+		 * and scope from a persistent reservation holder, it shall not
+		 * make any change to the existing persistent reservation and
+		 * shall completethe command with GOOD status.
+		 */
+		spin_unlock(&dev->dev_reservation_lock);
+		core_scsi3_put_pr_reg(pr_reg);
+		return PYX_TRANSPORT_SENT_TO_TRANSPORT;
+	}
+	/*
+	 * Otherwise, our *pr_reg becomes the PR reservation holder for said
+	 * TYPE/SCOPE.  Also set the received scope and type in *pr_reg.
+	 */
+	pr_reg->pr_res_scope = scope;
+	pr_reg->pr_res_type = type;
+	pr_reg->pr_res_holder = 1;
+	dev->dev_pr_res_holder = pr_reg;
+
+	printk(KERN_INFO "SPC-3 PR [%s] Service Action: RESERVE created new"
+		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
+		CMD_TFO(cmd)->get_fabric_name(), core_scsi3_pr_dump_type(type),
+		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
+	printk(KERN_INFO "SPC-3 PR [%s] RESERVE Node: %s\n",
+			CMD_TFO(cmd)->get_fabric_name(),
+			se_sess->se_node_acl->initiatorname);
+	spin_unlock(&dev->dev_reservation_lock);
+
+	core_scsi3_put_pr_reg(pr_reg);
+	return 0;
+}
+
+static int core_scsi3_emulate_pro_reserve(
+	se_cmd_t *cmd,
+	int type,
+	int scope,
+	u64 res_key)
+{
+	se_device_t *dev = cmd->se_dev;
+	int ret = 0;
+
+	switch (type) {
+	case PR_TYPE_WRITE_EXCLUSIVE:
+	case PR_TYPE_EXCLUSIVE_ACCESS:
+	case PR_TYPE_WRITE_EXCLUSIVE_REGONLY:
+	case PR_TYPE_EXCLUSIVE_ACCESS_REGONLY:
+	case PR_TYPE_WRITE_EXCLUSIVE_ALLREG:
+	case PR_TYPE_EXCLUSIVE_ACCESS_ALLREG:
+		ret = core_scsi3_pro_reserve(cmd, dev, type, scope, res_key);
+		break;
+	default:
+		printk(KERN_ERR "SPC-3 PR: Unknown Service Action RESERVE Type:"
+			" 0x%02x\n", type);
+		return PYX_TRANSPORT_INVALID_CDB_FIELD;
+	}
+
+	return ret;
+}
+
+/*
+ * Called with se_device_t->dev_reservation_lock held.
+ */
+static void __core_scsi3_complete_pro_release(
+	se_device_t *dev,
+	se_node_acl_t *se_nacl,
+	t10_pr_registration_t *pr_reg,
+	int explict)
+{
+	struct target_core_fabric_ops *tfo = se_nacl->se_tpg->se_tpg_tfo;
+	/*
+	 * Go ahead and release the current PR reservation holder.
+	 */
+	dev->dev_pr_res_holder = NULL;
+
+	printk(KERN_INFO "SPC-3 PR [%s] Service Action: %s RELEASE cleared"
+		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
+		tfo->get_fabric_name(), (explict) ? "explict" : "implict",
+		core_scsi3_pr_dump_type(pr_reg->pr_res_type),
+		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
+	printk(KERN_INFO "SPC-3 PR [%s] RELEASE Node: %s\n",
+		tfo->get_fabric_name(),
+		se_nacl->initiatorname);
+	/*
+	 * Clear TYPE and SCOPE for the next PROUT Service Action: RESERVE
+	 */
+	pr_reg->pr_res_holder = pr_reg->pr_res_type = pr_reg->pr_res_scope = 0;
+}
+
+static int core_scsi3_emulate_pro_release(
+	se_cmd_t *cmd,
+	int type,
+	int scope,
+	u64 res_key)
+{
+	se_device_t *dev = cmd->se_dev;
+	se_session_t *se_sess = SE_SESS(cmd);
+	se_lun_t *se_lun = SE_LUN(cmd);
+	t10_pr_registration_t *pr_reg, *pr_reg_p, *pr_res_holder;
+	t10_reservation_template_t *pr_tmpl = &SU_DEV(dev)->t10_reservation;
+
+	if (!(se_sess) || !(se_lun)) {
+		printk(KERN_ERR "SPC-3 PR: se_sess || se_lun_t is NULL!\n");
+		return PYX_TRANSPORT_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+	}
+	/*
+	 * Locate the existing *pr_reg via se_node_acl_t pointers
+	 */
+	pr_reg = core_scsi3_locate_pr_reg(dev, se_sess->se_node_acl);
+	if (!(pr_reg)) {
+		printk(KERN_ERR "SPC-3 PR: Unable to locate"
+			" PR_REGISTERED *pr_reg for RELEASE\n");
+		return PYX_TRANSPORT_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+	}
+	/*
+	 * From spc4r17 Section 5.7.11.2 Releasing:
+	 *
+	 * If there is no persistent reservation or in response to a persistent
+	 * reservation release request from a registered I_T nexus that is not a
+	 * persistent reservation holder (see 5.7.10), the device server shall
+	 * do the following:
+	 *
+	 *     a) Not release the persistent reservation, if any;
+	 *     b) Not remove any registrations; and
+	 *     c) Complete the command with GOOD status.
+	 */
+	spin_lock(&dev->dev_reservation_lock);
+	pr_res_holder = dev->dev_pr_res_holder;
+	if (!(pr_res_holder)) {
+		/*
+		 * No persistent reservation, return GOOD status.
+		 */
+		spin_unlock(&dev->dev_reservation_lock);
+		core_scsi3_put_pr_reg(pr_reg);
+		return PYX_TRANSPORT_SENT_TO_TRANSPORT;
+	}
+	if (pr_res_holder != pr_reg) {
+		/*
+		 * Release request from a registered I_T nexus that is not a
+		 * persistent reservation holder. return GOOD status.
+		 */
+		spin_unlock(&dev->dev_reservation_lock);
+		core_scsi3_put_pr_reg(pr_reg);
+		return PYX_TRANSPORT_SENT_TO_TRANSPORT;
+	}
+	/*
+	 * From spc4r17 Section 5.7.11.2 Releasing:
+	 *
+	 * Only the persistent reservation holder (see 5.7.10) is allowed to
+	 * release a persistent reservation.
+	 *
+	 * An application client releases the persistent reservation by issuing
+	 * a PERSISTENT RESERVE OUT command with RELEASE service action through
+	 * an I_T nexus that is a persistent reservation holder with the
+	 * following parameters:
+	 *
+	 *     a) RESERVATION KEY field set to the value of the reservation key
+	 *	  that is registered with the logical unit for the I_T nexus;
+	 */
+	if (res_key != pr_reg->pr_res_key) {
+		printk(KERN_ERR "SPC-3 PR RELEASE: Received res_key: 0x%016Lx"
+			" does not match existing SA REGISTER res_key:"
+			" 0x%016Lx\n", res_key, pr_reg->pr_res_key);
+		spin_unlock(&dev->dev_reservation_lock);
+		core_scsi3_put_pr_reg(pr_reg);
+		return PYX_TRANSPORT_RESERVATION_CONFLICT;
+	}
+	/*
+	 * From spc4r17 Section 5.7.11.2 Releasing and above:
+	 *
+	 * b) TYPE field and SCOPE field set to match the persistent
+	 *    reservation being released.
+	 */
+	if ((pr_res_holder->pr_res_type != type) ||
+	    (pr_res_holder->pr_res_scope != scope)) {
+		se_node_acl_t *pr_res_nacl = pr_res_holder->pr_reg_nacl;
+		printk(KERN_ERR "SPC-3 PR RELEASE: Attempted to release"
+			" reservation from [%s]: %s with different TYPE "
+			"and/or SCOPE  while reservation already held by"
+			" [%s]: %s, returning RESERVATION_CONFLICT\n",
+			CMD_TFO(cmd)->get_fabric_name(),
+			se_sess->se_node_acl->initiatorname,
+			TPG_TFO(pr_res_nacl->se_tpg)->get_fabric_name(),
+			pr_res_holder->pr_reg_nacl->initiatorname);
+
+		spin_unlock(&dev->dev_reservation_lock);
+		core_scsi3_put_pr_reg(pr_reg);
+		return PYX_TRANSPORT_RESERVATION_CONFLICT;
+	}
+	/*
+	 * In response to a persistent reservation release request from the
+	 * persistent reservation holder the device server shall perform a
+	 * release by doing the following as an uninterrupted series of actions:
+	 * a) Release the persistent reservation;
+	 * b) Not remove any registration(s);
+	 * c) If the released persistent reservation is a registrants only type
+	 * or all registrants type persistent reservation,
+	 *    the device server shall establish a unit attention condition for
+	 *    the initiator port associated with every regis-
+	 *    tered I_T nexus other than I_T nexus on which the PERSISTENT
+	 *    RESERVE OUT command with RELEASE service action was received,
+	 *    with the additional sense code set to RESERVATIONS RELEASED; and
+	 * d) If the persistent reservation is of any other type, the device
+	 *    server shall not establish a unit attention condition.
+	 */
+	__core_scsi3_complete_pro_release(dev, se_sess->se_node_acl,
+			pr_reg, 1);
+
+	if ((type != PR_TYPE_WRITE_EXCLUSIVE_REGONLY) &&
+	    (type != PR_TYPE_EXCLUSIVE_ACCESS_REGONLY) &&
+	    (type != PR_TYPE_WRITE_EXCLUSIVE_ALLREG) &&
+	    (type != PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)) {
+		spin_unlock(&dev->dev_reservation_lock);
+		core_scsi3_put_pr_reg(pr_reg);
+		return 0;
+	}
+	spin_unlock(&dev->dev_reservation_lock);
+
+	spin_lock(&pr_tmpl->registration_lock);
+	list_for_each_entry(pr_reg_p, &pr_tmpl->registration_list,
+			pr_reg_list) {
+		/*
+		 * Do not establish a UNIT ATTENTION condition
+		 * for the calling I_T Nexus
+		 */
+		if (pr_reg_p == pr_reg)
+			continue;
+
+		core_scsi3_ua_allocate(pr_reg_p->pr_reg_nacl,
+				pr_reg_p->pr_res_mapped_lun,
+				0x2A, ASCQ_2AH_RESERVATIONS_RELEASED);
+	}
+	spin_unlock(&pr_tmpl->registration_lock);
+
+	core_scsi3_put_pr_reg(pr_reg);
+	return 0;
+}
+
+static int core_scsi3_emulate_pro_clear(
+	se_cmd_t *cmd,
+	u64 res_key)
+{
+	se_device_t *dev = cmd->se_dev;
+	se_node_acl_t *pr_reg_nacl;
+	se_session_t *se_sess = SE_SESS(cmd);
+	t10_reservation_template_t *pr_tmpl = &SU_DEV(dev)->t10_reservation;
+	t10_pr_registration_t *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
+	u32 pr_res_mapped_lun = 0;
+	int calling_it_nexus = 0;
+	/*
+	 * Locate the existing *pr_reg via se_node_acl_t pointers
+	 */
+	pr_reg_n = core_scsi3_locate_pr_reg(SE_DEV(cmd),
+			se_sess->se_node_acl);
+	if (!(pr_reg_n)) {
+		printk(KERN_ERR "SPC-3 PR: Unable to locate"
+			" PR_REGISTERED *pr_reg for CLEAR\n");
+			return PYX_TRANSPORT_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+	}
+	/*
+	 * From spc4r17 section 5.7.11.6, Clearing:
+	 *
+	 * Any application client may release the persistent reservation and
+	 * remove all registrations from a device server by issuing a
+	 * PERSISTENT RESERVE OUT command with CLEAR service action through a
+	 * registered I_T nexus with the following parameter:
+	 *
+	 *	a) RESERVATION KEY field set to the value of the reservation key
+	 * 	   that is registered with the logical unit for the I_T nexus.
+	 */
+	if (res_key != pr_reg_n->pr_res_key) {
+		printk(KERN_ERR "SPC-3 PR REGISTER: Received"
+			" res_key: 0x%016Lx does not match"
+			" existing SA REGISTER res_key:"
+			" 0x%016Lx\n", res_key, pr_reg_n->pr_res_key);
+		core_scsi3_put_pr_reg(pr_reg_n);
+		return PYX_TRANSPORT_RESERVATION_CONFLICT;
+	}
+	/*
+	 * a) Release the persistent reservation, if any;
+	 */
+	spin_lock(&dev->dev_reservation_lock);
+	pr_res_holder = dev->dev_pr_res_holder;
+	if (pr_res_holder) {
+		se_node_acl_t *pr_res_nacl = pr_res_holder->pr_reg_nacl;
+		__core_scsi3_complete_pro_release(dev, pr_res_nacl,
+			pr_res_holder, 0);
+	}
+	spin_unlock(&dev->dev_reservation_lock);
+	/*
+	 * b) Remove all registration(s) (see spc4r17 5.7.7);
+	 */
+	spin_lock(&pr_tmpl->registration_lock);
+	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
+			&pr_tmpl->registration_list, pr_reg_list) {
+
+		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
+		pr_reg_nacl = pr_reg->pr_reg_nacl;
+		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
+		__core_scsi3_free_registration(dev, pr_reg, NULL,
+					calling_it_nexus);
+		/*
+		 * e) Establish a unit attention condition for the initiator
+		 *    port associated with every registered I_T nexus other
+		 *    than the I_T nexus on which the PERSISTENT RESERVE OUT
+		 *    command with CLEAR service action was received, with the
+		 *    additional sense code set to RESERVATIONS PREEMPTED.
+		 */
+		if (!(calling_it_nexus))
+			core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun,
+				0x2A, ASCQ_2AH_RESERVATIONS_PREEMPTED);
+	}
+	spin_unlock(&pr_tmpl->registration_lock);
+
+	printk(KERN_INFO "SPC-3 PR [%s] Service Action: CLEAR complete\n",
+		CMD_TFO(cmd)->get_fabric_name());
+
+	core_scsi3_pr_generation(dev);
+	return 0;
+}
+
+/*
+ * Called with se_device_t->dev_reservation_lock held.
+ */
+static void __core_scsi3_complete_pro_preempt(
+	se_device_t *dev,
+	t10_pr_registration_t *pr_reg,
+	struct list_head *preempt_and_abort_list,
+	int type,
+	int scope,
+	int abort)
+{
+	se_node_acl_t *nacl = pr_reg->pr_reg_nacl;
+	struct target_core_fabric_ops *tfo = nacl->se_tpg->se_tpg_tfo;
+	/*
+	 * Do an implict RELEASE of the existing reservation.
+	 */
+	if (dev->dev_pr_res_holder)
+		__core_scsi3_complete_pro_release(dev, nacl,
+				dev->dev_pr_res_holder, 0);
+
+	dev->dev_pr_res_holder = pr_reg;
+	pr_reg->pr_res_holder = 1;
+	pr_reg->pr_res_type = type;
+	pr_reg->pr_res_scope = scope;
+
+	printk(KERN_INFO "SPC-3 PR [%s] Service Action: PREEMPT%s created new"
+		" reservation holder TYPE: %s ALL_TG_PT: %d\n",
+		tfo->get_fabric_name(), (abort) ? "_AND_ABORT" : "",
+		core_scsi3_pr_dump_type(type),
+		(pr_reg->pr_reg_all_tg_pt) ? 1 : 0);
+	printk(KERN_INFO "SPC-3 PR [%s] PREEMPT%s from Node: %s\n",
+		tfo->get_fabric_name(), (abort) ? "_AND_ABORT" : "",
+		nacl->initiatorname);
+	/*
+	 * For PREEMPT_AND_ABORT, add the preempting reservation's
+	 * t10_pr_registration_t to the list that will be compared
+	 * against received CDBs..
+	 */
+	if (preempt_and_abort_list)
+		list_add_tail(&pr_reg->pr_reg_abort_list,
+				preempt_and_abort_list);
+}
+
+static void core_scsi3_release_preempt_and_abort(
+	struct list_head *preempt_and_abort_list,
+	t10_pr_registration_t *pr_reg_holder)
+{
+	t10_pr_registration_t *pr_reg, *pr_reg_tmp;
+
+	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
+				pr_reg_abort_list) {
+
+		list_del(&pr_reg->pr_reg_abort_list);
+		if (pr_reg_holder == pr_reg)
+			continue;
+		if (pr_reg->pr_res_holder) {
+			printk(KERN_WARNING "pr_reg->pr_res_holder still set\n");
+			continue;
+		}
+
+		pr_reg->pr_reg_deve = NULL;
+		pr_reg->pr_reg_nacl = NULL;
+		kmem_cache_free(t10_pr_reg_cache, pr_reg);
+	}
+}
+
+int core_scsi3_check_cdb_abort_and_preempt(
+	struct list_head *preempt_and_abort_list,
+	se_cmd_t *cmd)
+{
+	t10_pr_registration_t *pr_reg, *pr_reg_tmp;
+
+	list_for_each_entry_safe(pr_reg, pr_reg_tmp, preempt_and_abort_list,
+				pr_reg_abort_list) {
+		if (pr_reg->pr_res_key == cmd->pr_res_key)
+			return 0;
+	}
+
+	return 1;
+}
+
+static int core_scsi3_emulate_pro_preempt(
+	se_cmd_t *cmd,
+	int type,
+	int scope,
+	u64 res_key,
+	u64 sa_res_key,
+	int abort)
+{
+	se_device_t *dev = SE_DEV(cmd);
+	se_dev_entry_t *se_deve;
+	se_lun_t *se_lun = SE_LUN(cmd);
+	se_node_acl_t *pr_reg_nacl;
+	se_session_t *se_sess = SE_SESS(cmd);
+	struct list_head preempt_and_abort_list;
+	t10_pr_registration_t *pr_reg, *pr_reg_tmp, *pr_reg_n, *pr_res_holder;
+	t10_reservation_template_t *pr_tmpl = &SU_DEV(dev)->t10_reservation;
+	u32 pr_res_mapped_lun = 0;
+	int all_reg = 0, calling_it_nexus = 0, released_regs = 0;
+	int prh_type = 0, prh_scope = 0;
+
+	if (!(se_sess))
+		return PYX_TRANSPORT_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+
+	se_deve = &se_sess->se_node_acl->device_list[se_lun->unpacked_lun];
+	if (!(se_deve->deve_flags & DEF_PR_REGISTERED))
+		return PYX_TRANSPORT_RESERVATION_CONFLICT;
+
+	pr_reg_n = core_scsi3_locate_pr_reg(SE_DEV(cmd), se_sess->se_node_acl);
+	if (!(pr_reg_n)) {
+		printk(KERN_ERR "SPC-3 PR: Unable to locate"
+			" PR_REGISTERED *pr_reg for PREEMPT%s\n",
+			(abort) ? "_AND_ABORT" : "");
+		return PYX_TRANSPORT_RESERVATION_CONFLICT;
+	}
+	if (pr_reg_n->pr_res_key != res_key) {
+		core_scsi3_put_pr_reg(pr_reg_n);
+		return PYX_TRANSPORT_RESERVATION_CONFLICT;
+	}
+	if (scope != PR_SCOPE_LU_SCOPE) {
+		printk(KERN_ERR "SPC-3 PR: Illegal SCOPE: 0x%02x\n", scope);
+		core_scsi3_put_pr_reg(pr_reg_n);
+		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
+	}
+	INIT_LIST_HEAD(&preempt_and_abort_list);
+
+	spin_lock(&dev->dev_reservation_lock);
+	pr_res_holder = dev->dev_pr_res_holder;
+	if (pr_res_holder &&
+	   ((pr_res_holder->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
+	    (pr_res_holder->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG)))
+		all_reg = 1;
+
+	if (!(all_reg) && !(sa_res_key)) {
+		spin_unlock(&dev->dev_reservation_lock);
+		core_scsi3_put_pr_reg(pr_reg_n);
+		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
+	}
+	/*
+	 * From spc4r17, section 5.7.11.4.4 Removing Registrations:
+	 *
+	 * If the SERVICE ACTION RESERVATION KEY field does not identify a
+	 * persistent reservation holder or there is no persistent reservation
+	 * holder (i.e., there is no persistent reservation), then the device
+	 * server shall perform a preempt by doing the following in an
+	 * uninterrupted series of actions. (See below..)
+	 */
+	if (!(pr_res_holder) || (pr_res_holder->pr_res_key != sa_res_key)) {
+		/*
+		 * No existing or SA Reservation Key matching reservations..
+		 *
+		 * PROUT SA PREEMPT with All Registrant type reservations are
+		 * allowed to be processed without a matching SA Reservation Key
+		 */
+		spin_lock(&pr_tmpl->registration_lock);
+		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
+				&pr_tmpl->registration_list, pr_reg_list) {
+			/*
+			 * Removing of registrations in non all registrants
+			 * type reservations without a matching SA reservation
+			 * key.
+			 *
+			 * a) Remove the registrations for all I_T nexuses
+			 *    specified by the SERVICE ACTION RESERVATION KEY
+			 *    field;
+			 * b) Ignore the contents of the SCOPE and TYPE fields;
+			 * c) Process tasks as defined in 5.7.1; and
+			 * d) Establish a unit attention condition for the
+			 *    initiator port associated with every I_T nexus
+			 *    that lost its registration other than the I_T
+			 *    nexus on which the PERSISTENT RESERVE OUT command
+			 *    was received, with the additional sense code set
+			 *    to REGISTRATIONS PREEMPTED.
+			 */
+			if (!(all_reg)) {
+				if (pr_reg->pr_res_key != sa_res_key)
+					continue;
+
+				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
+				pr_reg_nacl = pr_reg->pr_reg_nacl;
+				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
+				__core_scsi3_free_registration(dev, pr_reg,
+					(abort) ? &preempt_and_abort_list :
+						NULL, calling_it_nexus);
+				released_regs++;
+			} else {
+				/*
+				 * Case for any existing all registrants type
+				 * reservation, follow logic in spc4r17 section
+				 * 5.7.11.4 Preempting, Table 52 and Figure 7.
+				 *
+				 * For a ZERO SA Reservation key, release
+				 * all other registrations and do an implict
+				 * release of active persistent reservation.
+				 *
+				 * For a non-ZERO SA Reservation key, only
+				 * release the matching reservation key from
+				 * registrations.
+				 */
+				if ((sa_res_key) &&
+				     (pr_reg->pr_res_key != sa_res_key))
+					continue;
+
+				calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
+				if (calling_it_nexus)
+					continue;
+
+				pr_reg_nacl = pr_reg->pr_reg_nacl;
+				pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
+				__core_scsi3_free_registration(dev, pr_reg,
+					(abort) ? &preempt_and_abort_list :
+						NULL, 0);
+				released_regs++;
+			}
+			if (!(calling_it_nexus))
+				core_scsi3_ua_allocate(pr_reg_nacl,
+					pr_res_mapped_lun, 0x2A,
+					ASCQ_2AH_RESERVATIONS_PREEMPTED);
+		}
+		spin_unlock(&pr_tmpl->registration_lock);
+		/*
+		 * If a PERSISTENT RESERVE OUT with a PREEMPT service action or
+		 * a PREEMPT AND ABORT service action sets the SERVICE ACTION
+		 * RESERVATION KEY field to a value that does not match any
+		 * registered reservation key, then the device server shall
+		 * complete the command with RESERVATION CONFLICT status.
+		 */
+		if (!(released_regs)) {
+			spin_unlock(&dev->dev_reservation_lock);
+			core_scsi3_put_pr_reg(pr_reg_n);
+			return PYX_TRANSPORT_RESERVATION_CONFLICT;
+		}
+		/*
+		 * For an existing all registrants type reservation
+		 * with a zero SA rservation key, preempt the existing
+		 * reservation with the new PR type and scope.
+		 */
+		if (pr_res_holder && all_reg && !(sa_res_key)) {
+			__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
+				(abort) ? &preempt_and_abort_list : NULL,
+				type, scope, abort);
+
+			if (abort)
+				core_scsi3_release_preempt_and_abort(
+					&preempt_and_abort_list, pr_reg_n);
+		}
+		spin_unlock(&dev->dev_reservation_lock);
+
+		core_scsi3_put_pr_reg(pr_reg_n);
+		core_scsi3_pr_generation(SE_DEV(cmd));
+		return 0;
+	}
+	/*
+	 * The PREEMPTing SA reservation key matches that of the
+	 * existing persistent reservation, first, we check if
+	 * we are preempting our own reservation.
+	 * From spc4r17, section 5.7.11.4.3 Preempting
+	 * persistent reservations and registration handling
+	 *
+	 * If an all registrants persistent reservation is not
+	 * present, it is not an error for the persistent
+	 * reservation holder to preempt itself (i.e., a
+	 * PERSISTENT RESERVE OUT with a PREEMPT service action
+	 * or a PREEMPT AND ABORT service action with the
+	 * SERVICE ACTION RESERVATION KEY value equal to the
+	 * persistent reservation holder's reservation key that
+	 * is received from the persistent reservation holder).
+	 * In that case, the device server shall establish the
+	 * new persistent reservation and maintain the
+	 * registration.
+	 */
+	prh_type = pr_res_holder->pr_res_type;
+	prh_scope = pr_res_holder->pr_res_scope;
+	/*
+	 * If the SERVICE ACTION RESERVATION KEY field identifies a
+	 * persistent reservation holder (see 5.7.10), the device
+	 * server shall perform a preempt by doing the following as
+	 * an uninterrupted series of actions:
+	 *
+	 * a) Release the persistent reservation for the holder
+	 *    identified by the SERVICE ACTION RESERVATION KEY field;
+	 */
+	if (pr_reg_n != pr_res_holder)
+		__core_scsi3_complete_pro_release(dev,
+				pr_res_holder->pr_reg_nacl,
+				dev->dev_pr_res_holder, 0);
+	/*
+	 * b) Remove the registrations for all I_T nexuses identified
+	 *    by the SERVICE ACTION RESERVATION KEY field, except the
+	 *    I_T nexus that is being used for the PERSISTENT RESERVE
+	 *    OUT command. If an all registrants persistent reservation
+	 *    is present and the SERVICE ACTION RESERVATION KEY field
+	 *    is set to zero, then all registrations shall be removed
+	 *    except for that of the I_T nexus that is being used for
+	 *    the PERSISTENT RESERVE OUT command;
+	 */
+	spin_lock(&pr_tmpl->registration_lock);
+	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
+			&pr_tmpl->registration_list, pr_reg_list) {
+
+		calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
+		if (calling_it_nexus)
+			continue;
+
+		if (pr_reg->pr_res_key != sa_res_key)
+			continue;
+
+		pr_reg_nacl = pr_reg->pr_reg_nacl;
+		pr_res_mapped_lun = pr_reg->pr_res_mapped_lun;
+		__core_scsi3_free_registration(dev, pr_reg,
+				(abort) ? &preempt_and_abort_list : NULL,
+				calling_it_nexus);
+		/*
+		 * e) Establish a unit attention condition for the initiator
+		 *    port associated with every I_T nexus that lost its
+		 *    persistent reservation and/or registration, with the
+		 *    additional sense code set to REGISTRATIONS PREEMPTED;
+		 */
+		core_scsi3_ua_allocate(pr_reg_nacl, pr_res_mapped_lun, 0x2A,
+				ASCQ_2AH_RESERVATIONS_PREEMPTED);
+	}
+	spin_unlock(&pr_tmpl->registration_lock);
+	/*
+	 * c) Establish a persistent reservation for the preempting
+	 *    I_T nexus using the contents of the SCOPE and TYPE fields;
+	 */
+	__core_scsi3_complete_pro_preempt(dev, pr_reg_n,
+			(abort) ? &preempt_and_abort_list : NULL,
+			type, scope, abort);
+	/*
+	 * d) Process tasks as defined in 5.7.1;
+	 * e) See above..
+	 * f) If the type or scope has changed, then for every I_T nexus
+	 *    whose reservation key was not removed, except for the I_T
+	 *    nexus on which the PERSISTENT RESERVE OUT command was
+	 *    received, the device server shall establish a unit
+	 *    attention condition for the initiator port associated with
+	 *    that I_T nexus, with the additional sense code set to
+	 *    RESERVATIONS RELEASED. If the type or scope have not
+	 *    changed, then no unit attention condition(s) shall be
+	 *    established for this reason.
+	 */
+	if ((prh_type != type) || (prh_scope != scope)) {
+		spin_lock(&pr_tmpl->registration_lock);
+		list_for_each_entry_safe(pr_reg, pr_reg_tmp,
+				&pr_tmpl->registration_list, pr_reg_list) {
+
+			calling_it_nexus = (pr_reg_n == pr_reg) ? 1 : 0;
+			if (calling_it_nexus)
+				continue;
+
+			core_scsi3_ua_allocate(pr_reg->pr_reg_nacl,
+					pr_reg->pr_res_mapped_lun, 0x2A,
+					ASCQ_2AH_RESERVATIONS_RELEASED);
+		}
+		spin_unlock(&pr_tmpl->registration_lock);
+	}
+	spin_unlock(&dev->dev_reservation_lock);
+	/*
+	 * Call LUN_RESET logic upon list of t10_pr_registration_t,
+	 * All received CDBs for the matching existing reservation and
+	 * registrations undergo ABORT_TASK logic.
+	 *
+	 * From there, core_scsi3_release_preempt_and_abort() will
+	 * release every registration in the list (which have already
+	 * been removed from the primary pr_reg list), except the
+	 * new persistent reservation holder, the calling Initiator Port.
+	 */
+	if (abort) {
+		core_tmr_lun_reset(dev, NULL, &preempt_and_abort_list, cmd);
+		core_scsi3_release_preempt_and_abort(&preempt_and_abort_list,
+						pr_reg_n);
+	}
+
+	core_scsi3_put_pr_reg(pr_reg_n);
+	core_scsi3_pr_generation(SE_DEV(cmd));
+	return 0;
+}
+
+#if 0
+static int core_scsi3_emulate_pro_register_and_move(
+	se_cmd_t *cmd,
+	int type,
+	int scope,
+	u64 res_key,
+	u64 sa_res_key)
+{
+	core_scsi3_pr_generation(SE_DEV(cmd));
+	return 0;
+}
+#endif
+
+static unsigned long long core_scsi3_extract_reservation_key(unsigned char *cdb)
+{
+	unsigned int __v1, __v2;
+
+	__v1 = (cdb[0] << 24) | (cdb[1] << 16) | (cdb[2] << 8) | cdb[3];
+	__v2 = (cdb[4] << 24) | (cdb[5] << 16) | (cdb[6] << 8) | cdb[7];
+
+	return ((unsigned long long)__v2) | (unsigned long long)__v1 << 32;
+}
+
+/*
+ * See spc4r17 section 6.14 Table 170
+ */
+static int core_scsi3_emulate_pr_out(se_cmd_t *cmd, unsigned char *cdb)
+{
+	unsigned char *buf = (unsigned char *)T_TASK(cmd)->t_task_buf;
+	u64 res_key, sa_res_key;
+	int scope, type, spec_i_pt, all_tg_pt, aptpl;
+
+	/*
+	 * FIXME: A NULL se_session_t pointer means an this is not coming from
+	 * a $FABRIC_MOD's nexus, but from internal passthrough ops.
+	 */
+	if (!(SE_SESS(cmd)))
+		return PYX_TRANSPORT_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+
+	/*
+	 * From the PERSISTENT_RESERVE_OUT command descriptor block (CDB)
+	 */
+	scope = (cdb[2] & 0xf0);
+	type = (cdb[2] & 0x0f);
+	/*
+	 * From PERSISTENT_RESERVE_OUT parameter list (payload)
+	 */
+	res_key = core_scsi3_extract_reservation_key(&buf[0]);
+	sa_res_key = core_scsi3_extract_reservation_key(&buf[8]);
+	spec_i_pt = (buf[20] & 0x08);
+	all_tg_pt = (buf[20] & 0x04);
+	aptpl = (buf[20] & 0x01);
+
+	/*
+	 * SPEC_I_PT=1 is only valid for Service action: REGISTER
+	 */
+	if (spec_i_pt && ((cdb[1] & 0x1f) != PRO_REGISTER))
+		return PYX_TRANSPORT_INVALID_PARAMETER_LIST;
+	/*
+	 * (core_scsi3_emulate_pro_* function parameters
+	 * are defined by spc4r17 Table 174:
+	 * PERSISTENT_RESERVE_OUT service actions and valid parameters.
+	 */
+	switch (cdb[1] & 0x1f) {
+	case PRO_REGISTER:
+		return core_scsi3_emulate_pro_register(cmd,
+			res_key, sa_res_key, aptpl, all_tg_pt, spec_i_pt, 0);
+	case PRO_RESERVE:
+		return core_scsi3_emulate_pro_reserve(cmd,
+			type, scope, res_key);
+	case PRO_RELEASE:
+		return core_scsi3_emulate_pro_release(cmd,
+			type, scope, res_key);
+	case PRO_CLEAR:
+		return core_scsi3_emulate_pro_clear(cmd, res_key);
+	case PRO_PREEMPT:
+		return core_scsi3_emulate_pro_preempt(cmd, type, scope,
+					res_key, sa_res_key, 0);
+	case PRO_PREEMPT_AND_ABORT:
+		return core_scsi3_emulate_pro_preempt(cmd, type, scope,
+					res_key, sa_res_key, 1);
+	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
+		return core_scsi3_emulate_pro_register(cmd,
+			0, sa_res_key, aptpl, all_tg_pt, spec_i_pt, 1);
+#if 0
+	case PRO_REGISTER_AND_MOVE:
+		return core_scsi3_emulate_pro_register_and_move(cmd,
+			type, scope, res_key, sa_res_key);
+#endif
+	default:
+		printk(KERN_ERR "Unknown PERSISTENT_RESERVE_OUT service"
+			" action: 0x%02x\n", cdb[1] & 0x1f);
+		return PYX_TRANSPORT_INVALID_CDB_FIELD;
+	}
+
+	return PYX_TRANSPORT_INVALID_CDB_FIELD;
+}
+
+/*
+ * PERSISTENT_RESERVE_IN Service Action READ_KEYS
+ *
+ * See spc4r17 section 5.7.6.2 and section 6.13.2, Table 160
+ */
+static int core_scsi3_pri_read_keys(se_cmd_t *cmd)
+{
+	se_device_t *se_dev = SE_DEV(cmd);
+	se_subsystem_dev_t *su_dev = SU_DEV(se_dev);
+	t10_pr_registration_t *pr_reg;
+	unsigned char *buf = (unsigned char *)T_TASK(cmd)->t_task_buf;
+	u32 add_len = 0, off = 8;
+
+	buf[0] = ((T10_RES(su_dev)->pr_generation >> 24) & 0xff);
+	buf[1] = ((T10_RES(su_dev)->pr_generation >> 16) & 0xff);
+	buf[2] = ((T10_RES(su_dev)->pr_generation >> 8) & 0xff);
+	buf[3] = (T10_RES(su_dev)->pr_generation & 0xff);
+
+	spin_lock(&T10_RES(su_dev)->registration_lock);
+	list_for_each_entry(pr_reg, &T10_RES(su_dev)->registration_list,
+			pr_reg_list) {
+		/*
+		 * Check for overflow of 8byte PRI READ_KEYS payload and
+		 * next reservation key list descriptor.
+		 */
+		if ((add_len + 8) > (cmd->data_length - 8))
+			break;
+
+		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
+		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
+		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
+		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
+		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
+		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
+		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
+		buf[off++] = (pr_reg->pr_res_key & 0xff);
+
+		add_len += 8;
+	}
+	spin_unlock(&T10_RES(su_dev)->registration_lock);
+
+	buf[4] = ((add_len >> 24) & 0xff);
+	buf[5] = ((add_len >> 16) & 0xff);
+	buf[6] = ((add_len >> 8) & 0xff);
+	buf[7] = (add_len & 0xff);
+
+	return 0;
+}
+
+/*
+ * PERSISTENT_RESERVE_IN Service Action READ_RESERVATION
+ *
+ * See spc4r17 section 5.7.6.3 and section 6.13.3.2 Table 161 and 162
+ */
+static int core_scsi3_pri_read_reservation(se_cmd_t *cmd)
+{
+	se_device_t *se_dev = SE_DEV(cmd);
+	se_subsystem_dev_t *su_dev = SU_DEV(se_dev);
+	t10_pr_registration_t *pr_reg;
+	unsigned char *buf = (unsigned char *)T_TASK(cmd)->t_task_buf;
+	u64 pr_res_key;
+	u32 add_len = 16; /* Hardcoded to 16 when a reservation is held. */
+
+	buf[0] = ((T10_RES(su_dev)->pr_generation >> 24) & 0xff);
+	buf[1] = ((T10_RES(su_dev)->pr_generation >> 16) & 0xff);
+	buf[2] = ((T10_RES(su_dev)->pr_generation >> 8) & 0xff);
+	buf[3] = (T10_RES(su_dev)->pr_generation & 0xff);
+
+	spin_lock(&se_dev->dev_reservation_lock);
+	pr_reg = se_dev->dev_pr_res_holder;
+	if ((pr_reg)) {
+		/*
+		 * Set the hardcoded Additional Length
+		 */
+		buf[4] = ((add_len >> 24) & 0xff);
+		buf[5] = ((add_len >> 16) & 0xff);
+		buf[6] = ((add_len >> 8) & 0xff);
+		buf[7] = (add_len & 0xff);
+		/*
+		 * Set the Reservation key.
+		 *
+		 * From spc4r17, section 5.7.10:
+		 * A persistent reservation holder has its reservation key
+		 * returned in the parameter data from a PERSISTENT
+		 * RESERVE IN command with READ RESERVATION service action as
+		 * follows:
+		 * a) For a persistent reservation of the type Write Exclusive
+		 *    - All Registrants or Exclusive Access ­ All Regitrants,
+		 *      the reservation key shall be set to zero; or
+		 * b) For all other persistent reservation types, the
+		 *    reservation key shall be set to the registered
+		 *    reservation key for the I_T nexus that holds the
+		 *    persistent reservation.
+		 */
+		if ((pr_reg->pr_res_type == PR_TYPE_WRITE_EXCLUSIVE_ALLREG) ||
+		    (pr_reg->pr_res_type == PR_TYPE_EXCLUSIVE_ACCESS_ALLREG))
+			pr_res_key = 0;
+		else
+			pr_res_key = pr_reg->pr_res_key;
+
+		buf[8] = ((pr_res_key >> 56) & 0xff);
+		buf[9] = ((pr_res_key >> 48) & 0xff);
+		buf[10] = ((pr_res_key >> 40) & 0xff);
+		buf[11] = ((pr_res_key >> 32) & 0xff);
+		buf[12] = ((pr_res_key >> 24) & 0xff);
+		buf[13] = ((pr_res_key >> 16) & 0xff);
+		buf[14] = ((pr_res_key >> 8) & 0xff);
+		buf[15] = (pr_res_key & 0xff);
+		/*
+		 * Set the SCOPE and TYPE
+		 */
+		buf[21] = (pr_reg->pr_res_scope & 0xf0) |
+			  (pr_reg->pr_res_type & 0x0f);
+	}
+	spin_unlock(&se_dev->dev_reservation_lock);
+
+	return 0;
+}
+
+/*
+ * PERSISTENT_RESERVE_IN Service Action REPORT_CAPABILITIES
+ *
+ * See spc4r17 section 6.13.4 Table 165
+ */
+static int core_scsi3_pri_report_capabilities(se_cmd_t *cmd)
+{
+	unsigned char *buf = (unsigned char *)T_TASK(cmd)->t_task_buf;
+	u16 add_len = 8; /* Hardcoded to 8. */
+
+	buf[0] = ((add_len << 8) & 0xff);
+	buf[1] = (add_len & 0xff);
+	/*
+	 * FIXME: Leave these features disabled for now..
+	 */
+#if 0
+	buf[2] |= 0x10; /* CRH: Compatible Reservation Hanlding bit. */
+	buf[2] |= 0x08; /* SIP_C: Specify Initiator Ports Capable bit */
+#endif
+	buf[2] |= 0x04; /* ATP_C: All Target Ports Capable bit */
+#if 0
+	buf[2] |= 0x01; /* PTPL_C: Persistence across Target Power Loss bit */
+#endif
+	/*
+	 * We are filling in the PERSISTENT RESERVATION TYPE MASK below, so
+	 * set the TMV: Task Mask Valid bit.
+	 */
+	buf[3] |= 0x80;
+	/*
+	 * Change ALLOW COMMANDs to 0x20 or 0x40 later from Table 166
+	 */
+	buf[3] |= 0x10; /* ALLOW COMMANDs field 001b */
+	/*
+	 * PTPL_A: Persistence across Target Power Loss Active bit
+	 */
+#if 0
+	buf[3] |= 0x01;
+#endif
+	/*
+	 * Setup the PERSISTENT RESERVATION TYPE MASK from Table 167
+	 */
+	buf[4] |= 0x80; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
+	buf[4] |= 0x40; /* PR_TYPE_EXCLUSIVE_ACCESS_REGONLY */
+	buf[4] |= 0x20; /* PR_TYPE_WRITE_EXCLUSIVE_REGONLY */
+	buf[4] |= 0x08; /* PR_TYPE_EXCLUSIVE_ACCESS */
+	buf[4] |= 0x02; /* PR_TYPE_WRITE_EXCLUSIVE */
+	buf[5] |= 0x01; /* PR_TYPE_EXCLUSIVE_ACCESS_ALLREG */
+
+	return 0;
+}
+
+/*
+ * PERSISTENT_RESERVE_IN Service Action READ_FULL_STATUS
+ *
+ * See spc4r17 section 6.13.5 Table 168 and 169
+ */
+static int core_scsi3_pri_read_full_status(se_cmd_t *cmd)
+{
+	se_device_t *se_dev = SE_DEV(cmd);
+	se_node_acl_t *se_nacl;
+	se_subsystem_dev_t *su_dev = SU_DEV(se_dev);
+	se_portal_group_t *se_tpg;
+	t10_pr_registration_t *pr_reg, *pr_reg_tmp;
+	t10_reservation_template_t *pr_tmpl = &SU_DEV(se_dev)->t10_reservation;
+	unsigned char *buf = (unsigned char *)T_TASK(cmd)->t_task_buf;
+	u32 add_desc_len = 0, add_len = 0, desc_len, exp_desc_len;
+	u32 off = 8; /* off into first Full Status descriptor */
+	int format_code = 0;
+
+	buf[0] = ((T10_RES(su_dev)->pr_generation >> 24) & 0xff);
+	buf[1] = ((T10_RES(su_dev)->pr_generation >> 16) & 0xff);
+	buf[2] = ((T10_RES(su_dev)->pr_generation >> 8) & 0xff);
+	buf[3] = (T10_RES(su_dev)->pr_generation & 0xff);
+
+	spin_lock(&pr_tmpl->registration_lock);
+	list_for_each_entry_safe(pr_reg, pr_reg_tmp,
+			&pr_tmpl->registration_list, pr_reg_list) {
+
+		se_nacl = pr_reg->pr_reg_nacl;
+		se_tpg = pr_reg->pr_reg_nacl->se_tpg;
+		add_desc_len = 0;
+		/*
+		 * Determine expected length of $FABRIC_MOD specific
+		 * TransportID full status descriptor..
+		 */
+		exp_desc_len = TPG_TFO(se_tpg)->tpg_get_pr_transport_id_len(
+				se_tpg, se_nacl, &format_code);
+
+		if ((exp_desc_len + add_len) > cmd->data_length) {
+			printk(KERN_WARNING "SPC-3 PRIN READ_FULL_STATUS ran"
+				" out of buffer: %d\n", cmd->data_length);
+			break;
+		}
+		/*
+		 * Set RESERVATION KEY
+		 */
+		buf[off++] = ((pr_reg->pr_res_key >> 56) & 0xff);
+		buf[off++] = ((pr_reg->pr_res_key >> 48) & 0xff);
+		buf[off++] = ((pr_reg->pr_res_key >> 40) & 0xff);
+		buf[off++] = ((pr_reg->pr_res_key >> 32) & 0xff);
+		buf[off++] = ((pr_reg->pr_res_key >> 24) & 0xff);
+		buf[off++] = ((pr_reg->pr_res_key >> 16) & 0xff);
+		buf[off++] = ((pr_reg->pr_res_key >> 8) & 0xff);
+		buf[off++] = (pr_reg->pr_res_key & 0xff);
+		off += 4; /* Skip Over Reserved area */
+
+		/*
+		 * Set ALL_TG_PT bit if PROUT SA REGISTER had this set.
+		 */
+		if (pr_reg->pr_reg_all_tg_pt)
+			buf[off] = 0x02;
+		/*
+		 * The se_lun_t pointer will be present for the
+		 * reservation holder for PR_HOLDER bit.
+		 *
+		 * Also, if this registration is the reservation
+		 * holder, fill in SCOPE and TYPE in the next byte.
+		 */
+		if (pr_reg->pr_res_holder) {
+			buf[off++] |= 0x01;
+			buf[off++] = (pr_reg->pr_res_scope & 0xf0) |
+				     (pr_reg->pr_res_type & 0x0f);
+		} else
+			off += 2;
+
+		off += 4; /* Skip over reserved area */
+		/*
+		 * From spc4r17 6.3.15:
+		 *
+		 * If the ALL_TG_PT bit set to zero, the RELATIVE TARGET PORT
+		 * IDENTIFIER field contains the relative port identifier (see
+		 * 3.1.120) of the target port that is part of the I_T nexus
+		 * described by this full status descriptor. If the ALL_TG_PT
+		 * bit is set to one, the contents of the RELATIVE TARGET PORT
+		 * IDENTIFIER field are not defined by this standard.
+		 */
+		if (!(pr_reg->pr_reg_all_tg_pt)) {
+			se_port_t *port = pr_reg->pr_reg_tg_pt_lun->lun_sep;
+
+			buf[off++] = ((port->sep_rtpi >> 8) & 0xff);
+			buf[off++] = (port->sep_rtpi & 0xff);
+		} else
+			off += 2; /* Skip over RELATIVE TARGET PORT IDENTIFER */
+
+		/*
+		 * Now, have the $FABRIC_MOD fill in the protocol identifier
+		 */
+		desc_len = TPG_TFO(se_tpg)->tpg_get_pr_transport_id(se_tpg,
+				se_nacl, &format_code, &buf[off+4]);
+		/*
+		 * Set the ADDITIONAL DESCRIPTOR LENGTH
+		 */
+		buf[off++] = ((desc_len >> 24) & 0xff);
+		buf[off++] = ((desc_len >> 16) & 0xff);
+		buf[off++] = ((desc_len >> 8) & 0xff);
+		buf[off++] = (desc_len & 0xff);
+		/*
+		 * Size of full desctipor header minus TransportID
+		 * containing $FABRIC_MOD specific) initiator device/port
+		 * WWN information.
+		 *
+		 *  See spc4r17 Section 6.13.5 Table 169
+		 */
+		add_desc_len = (24 + desc_len);
+
+		off += desc_len;
+		add_len += add_desc_len;
+	}
+	spin_unlock(&pr_tmpl->registration_lock);
+	/*
+	 * Set ADDITIONAL_LENGTH
+	 */
+	buf[4] = ((add_len >> 24) & 0xff);
+	buf[5] = ((add_len >> 16) & 0xff);
+	buf[6] = ((add_len >> 8) & 0xff);
+	buf[7] = (add_len & 0xff);
+
+	return 0;
+}
+
+static int core_scsi3_emulate_pr_in(se_cmd_t *cmd, unsigned char *cdb)
+{
+	switch (cdb[1] & 0x1f) {
+	case PRI_READ_KEYS:
+		return core_scsi3_pri_read_keys(cmd);
+	case PRI_READ_RESERVATION:
+		return core_scsi3_pri_read_reservation(cmd);
+	case PRI_REPORT_CAPABILITIES:
+		return core_scsi3_pri_report_capabilities(cmd);
+	case PRI_READ_FULL_STATUS:
+		return core_scsi3_pri_read_full_status(cmd);
+	default:
+		printk(KERN_ERR "Unknown PERSISTENT_RESERVE_IN service"
+			" action: 0x%02x\n", cdb[1] & 0x1f);
+		return PYX_TRANSPORT_INVALID_CDB_FIELD;
+	}
+
+}
+
+int core_scsi3_emulate_pr(se_cmd_t *cmd)
+{
+	unsigned char *cdb = &T_TASK(cmd)->t_task_cdb[0];
+
+	return (cdb[0] == PERSISTENT_RESERVE_OUT) ?
+	       core_scsi3_emulate_pr_out(cmd, cdb) :
+	       core_scsi3_emulate_pr_in(cmd, cdb);
+}
+
+static int core_pt_reservation_check(se_cmd_t *cmd, u32 *pr_res_type)
+{
+	return 0;
+}
+
+static int core_pt_reserve(se_cmd_t *cmd)
+{
+	return 0;
+}
+
+static int core_pt_release(se_cmd_t *cmd)
+{
+	return 0;
+}
+
+static int core_pt_seq_non_holder(
+	se_cmd_t *cmd,
+	unsigned char *cdb,
+	u32 pr_reg_type)
+{
+	return 0;
+}
+
+int core_setup_reservations(se_device_t *dev)
+{
+	se_subsystem_dev_t *su_dev = dev->se_sub_dev;
+	t10_reservation_template_t *rest = &su_dev->t10_reservation;
+	/*
+	 * If this device is from Target_Core_Mod/pSCSI, use the reservations
+	 * 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 to emulate reservations themselves.
+	 */
+	if ((TRANSPORT(dev)->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) &&
+	    !(DEV_ATTRIB(dev)->emulate_reservations)) {
+		rest->res_type = SPC_PASSTHROUGH;
+		rest->t10_reservation_check = &core_pt_reservation_check;
+		rest->t10_reserve = &core_pt_reserve;
+		rest->t10_release = &core_pt_release;
+		rest->t10_seq_non_holder = &core_pt_seq_non_holder;
+		printk(KERN_INFO "%s: Using SPC_PASSTHROUGH, no reservation"
+			" emulation\n", TRANSPORT(dev)->name);
+		return 0;
+	}
+	/*
+	 * If SPC-3 or above is reported by real or emulated se_device_t,
+	 * use emulated Persistent Reservations.
+	 */
+	if (TRANSPORT(dev)->get_device_rev(dev) >= SCSI_3) {
+		rest->res_type = SPC3_PERSISTENT_RESERVATIONS;
+		rest->t10_reservation_check = &core_scsi3_pr_reservation_check;
+		rest->t10_reserve = &core_scsi3_legacy_reserve;
+		rest->t10_release = &core_scsi3_legacy_release;
+		rest->t10_seq_non_holder = &core_scsi3_pr_seq_non_holder;
+		printk(KERN_INFO "%s: Using SPC3_PERSISTENT_RESERVATIONS"
+			" emulation\n", TRANSPORT(dev)->name);
+	} else {
+		rest->res_type = SPC2_RESERVATIONS;
+		rest->t10_reservation_check = &core_scsi2_reservation_check;
+		rest->t10_reserve = &core_scsi2_reservation_reserve;
+		rest->t10_release = &core_scsi2_reservation_release;
+		rest->t10_seq_non_holder =
+				&core_scsi2_reservation_seq_non_holder;
+		printk(KERN_INFO "%s: Using SPC2_RESERVATIONS emulation\n",
+			TRANSPORT(dev)->name);
+	}
+
+	return 0;
+}
diff --git a/include/target/target_core_pr.h b/include/target/target_core_pr.h
new file mode 100644
index 0000000..23d9e18
--- /dev/null
+++ b/include/target/target_core_pr.h
@@ -0,0 +1,54 @@
+#ifndef TARGET_CORE_PR_H
+#define TARGET_CORE_PR_H
+/*
+ * PERSISTENT_RESERVE_OUT service action codes
+ *
+ * spc4r17 section 6.14.2 Table 171
+ */
+#define PRO_REGISTER				0x00
+#define PRO_RESERVE				0x01
+#define PRO_RELEASE				0x02
+#define PRO_CLEAR				0x03
+#define PRO_PREEMPT				0x04
+#define PRO_PREEMPT_AND_ABORT			0x05
+#define PRO_REGISTER_AND_IGNORE_EXISTING_KEY	0x06
+#define PRO_REGISTER_AND_MOVE			0x07
+/*
+ * PERSISTENT_RESERVE_IN service action codes
+ *
+ * spc4r17 section 6.13.1 Table 159
+ */
+#define PRI_READ_KEYS				0x00
+#define PRI_READ_RESERVATION			0x01
+#define PRI_REPORT_CAPABILITIES			0x02
+#define PRI_READ_FULL_STATUS			0x03
+/*
+ * PERSISTENT_RESERVE_ SCOPE field
+ *
+ * spc4r17 section 6.13.3.3 Table 163
+ */
+#define PR_SCOPE_LU_SCOPE			0x00
+/*
+ * PERSISTENT_RESERVE_* TYPE field
+ *
+ * spc4r17 section 6.13.3.4 Table 164
+ */
+#define PR_TYPE_WRITE_EXCLUSIVE			0x01
+#define PR_TYPE_EXCLUSIVE_ACCESS		0x03
+#define PR_TYPE_WRITE_EXCLUSIVE_REGONLY		0x05
+#define PR_TYPE_EXCLUSIVE_ACCESS_REGONLY	0x06
+#define PR_TYPE_WRITE_EXCLUSIVE_ALLREG		0x07
+#define PR_TYPE_EXCLUSIVE_ACCESS_ALLREG		0x08
+
+extern struct kmem_cache *t10_pr_reg_cache;
+
+extern void core_scsi3_free_pr_reg_from_nacl(struct se_device_s *,
+					     struct se_node_acl_s *);
+extern void core_scsi3_free_all_registrations(struct se_device_s *);
+extern unsigned char *core_scsi3_pr_dump_type(int);
+extern int core_scsi3_check_cdb_abort_and_preempt(struct list_head *,
+						  struct se_cmd_s *);
+extern int core_scsi3_emulate_pr(struct se_cmd_s *);
+extern int core_setup_reservations(struct se_device_s *);
+
+#endif /* TARGET_CORE_PR_H */


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