Initial import

1 files changed, 3076 insertions, 0 deletions

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
new file mode 100644
index 000000000..675f2d9d1
--- /dev/null
+++ b/drivers/target/target_core_transport.c
@@ -0,0 +1,3076 @@
+/*******************************************************************************
+ * Filename:  target_core_transport.c
+ *
+ * This file contains the Generic Target Engine Core.
+ *
+ * (c) Copyright 2002-2013 Datera, Inc.
+ *
+ * Nicholas A. Bellinger <nab@kernel.org>
+ *
+ * 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.
+ *
+ ******************************************************************************/
+
+#include <linux/net.h>
+#include <linux/delay.h>
+#include <linux/string.h>
+#include <linux/timer.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/kthread.h>
+#include <linux/in.h>
+#include <linux/cdrom.h>
+#include <linux/module.h>
+#include <linux/ratelimit.h>
+#include <asm/unaligned.h>
+#include <net/sock.h>
+#include <net/tcp.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_tcq.h>
+
+#include <target/target_core_base.h>
+#include <target/target_core_backend.h>
+#include <target/target_core_fabric.h>
+#include <target/target_core_configfs.h>
+
+#include "target_core_internal.h"
+#include "target_core_alua.h"
+#include "target_core_pr.h"
+#include "target_core_ua.h"
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/target.h>
+
+static struct workqueue_struct *target_completion_wq;
+static struct kmem_cache *se_sess_cache;
+struct kmem_cache *se_ua_cache;
+struct kmem_cache *t10_pr_reg_cache;
+struct kmem_cache *t10_alua_lu_gp_cache;
+struct kmem_cache *t10_alua_lu_gp_mem_cache;
+struct kmem_cache *t10_alua_tg_pt_gp_cache;
+struct kmem_cache *t10_alua_tg_pt_gp_mem_cache;
+struct kmem_cache *t10_alua_lba_map_cache;
+struct kmem_cache *t10_alua_lba_map_mem_cache;
+
+static void transport_complete_task_attr(struct se_cmd *cmd);
+static void transport_handle_queue_full(struct se_cmd *cmd,
+		struct se_device *dev);
+static int transport_put_cmd(struct se_cmd *cmd);
+static void target_complete_ok_work(struct work_struct *work);
+
+int init_se_kmem_caches(void)
+{
+	se_sess_cache = kmem_cache_create("se_sess_cache",
+			sizeof(struct se_session), __alignof__(struct se_session),
+			0, NULL);
+	if (!se_sess_cache) {
+		pr_err("kmem_cache_create() for struct se_session"
+				" failed\n");
+		goto out;
+	}
+	se_ua_cache = kmem_cache_create("se_ua_cache",
+			sizeof(struct se_ua), __alignof__(struct se_ua),
+			0, NULL);
+	if (!se_ua_cache) {
+		pr_err("kmem_cache_create() for struct se_ua failed\n");
+		goto out_free_sess_cache;
+	}
+	t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
+			sizeof(struct t10_pr_registration),
+			__alignof__(struct t10_pr_registration), 0, NULL);
+	if (!t10_pr_reg_cache) {
+		pr_err("kmem_cache_create() for struct t10_pr_registration"
+				" failed\n");
+		goto out_free_ua_cache;
+	}
+	t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
+			sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
+			0, NULL);
+	if (!t10_alua_lu_gp_cache) {
+		pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
+				" failed\n");
+		goto out_free_pr_reg_cache;
+	}
+	t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
+			sizeof(struct t10_alua_lu_gp_member),
+			__alignof__(struct t10_alua_lu_gp_member), 0, NULL);
+	if (!t10_alua_lu_gp_mem_cache) {
+		pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
+				"cache failed\n");
+		goto out_free_lu_gp_cache;
+	}
+	t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
+			sizeof(struct t10_alua_tg_pt_gp),
+			__alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
+	if (!t10_alua_tg_pt_gp_cache) {
+		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
+				"cache failed\n");
+		goto out_free_lu_gp_mem_cache;
+	}
+	t10_alua_tg_pt_gp_mem_cache = kmem_cache_create(
+			"t10_alua_tg_pt_gp_mem_cache",
+			sizeof(struct t10_alua_tg_pt_gp_member),
+			__alignof__(struct t10_alua_tg_pt_gp_member),
+			0, NULL);
+	if (!t10_alua_tg_pt_gp_mem_cache) {
+		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
+				"mem_t failed\n");
+		goto out_free_tg_pt_gp_cache;
+	}
+	t10_alua_lba_map_cache = kmem_cache_create(
+			"t10_alua_lba_map_cache",
+			sizeof(struct t10_alua_lba_map),
+			__alignof__(struct t10_alua_lba_map), 0, NULL);
+	if (!t10_alua_lba_map_cache) {
+		pr_err("kmem_cache_create() for t10_alua_lba_map_"
+				"cache failed\n");
+		goto out_free_tg_pt_gp_mem_cache;
+	}
+	t10_alua_lba_map_mem_cache = kmem_cache_create(
+			"t10_alua_lba_map_mem_cache",
+			sizeof(struct t10_alua_lba_map_member),
+			__alignof__(struct t10_alua_lba_map_member), 0, NULL);
+	if (!t10_alua_lba_map_mem_cache) {
+		pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
+				"cache failed\n");
+		goto out_free_lba_map_cache;
+	}
+
+	target_completion_wq = alloc_workqueue("target_completion",
+					       WQ_MEM_RECLAIM, 0);
+	if (!target_completion_wq)
+		goto out_free_lba_map_mem_cache;
+
+	return 0;
+
+out_free_lba_map_mem_cache:
+	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
+out_free_lba_map_cache:
+	kmem_cache_destroy(t10_alua_lba_map_cache);
+out_free_tg_pt_gp_mem_cache:
+	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
+out_free_tg_pt_gp_cache:
+	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
+out_free_lu_gp_mem_cache:
+	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
+out_free_lu_gp_cache:
+	kmem_cache_destroy(t10_alua_lu_gp_cache);
+out_free_pr_reg_cache:
+	kmem_cache_destroy(t10_pr_reg_cache);
+out_free_ua_cache:
+	kmem_cache_destroy(se_ua_cache);
+out_free_sess_cache:
+	kmem_cache_destroy(se_sess_cache);
+out:
+	return -ENOMEM;
+}
+
+void release_se_kmem_caches(void)
+{
+	destroy_workqueue(target_completion_wq);
+	kmem_cache_destroy(se_sess_cache);
+	kmem_cache_destroy(se_ua_cache);
+	kmem_cache_destroy(t10_pr_reg_cache);
+	kmem_cache_destroy(t10_alua_lu_gp_cache);
+	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
+	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
+	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
+	kmem_cache_destroy(t10_alua_lba_map_cache);
+	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
+}
+
+/* This code ensures unique mib indexes are handed out. */
+static DEFINE_SPINLOCK(scsi_mib_index_lock);
+static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
+
+/*
+ * Allocate a new row index for the entry type specified
+ */
+u32 scsi_get_new_index(scsi_index_t type)
+{
+	u32 new_index;
+
+	BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
+
+	spin_lock(&scsi_mib_index_lock);
+	new_index = ++scsi_mib_index[type];
+	spin_unlock(&scsi_mib_index_lock);
+
+	return new_index;
+}
+
+void transport_subsystem_check_init(void)
+{
+	int ret;
+	static int sub_api_initialized;
+
+	if (sub_api_initialized)
+		return;
+
+	ret = request_module("target_core_iblock");
+	if (ret != 0)
+		pr_err("Unable to load target_core_iblock\n");
+
+	ret = request_module("target_core_file");
+	if (ret != 0)
+		pr_err("Unable to load target_core_file\n");
+
+	ret = request_module("target_core_pscsi");
+	if (ret != 0)
+		pr_err("Unable to load target_core_pscsi\n");
+
+	ret = request_module("target_core_user");
+	if (ret != 0)
+		pr_err("Unable to load target_core_user\n");
+
+	sub_api_initialized = 1;
+}
+
+struct se_session *transport_init_session(enum target_prot_op sup_prot_ops)
+{
+	struct se_session *se_sess;
+
+	se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
+	if (!se_sess) {
+		pr_err("Unable to allocate struct se_session from"
+				" se_sess_cache\n");
+		return ERR_PTR(-ENOMEM);
+	}
+	INIT_LIST_HEAD(&se_sess->sess_list);
+	INIT_LIST_HEAD(&se_sess->sess_acl_list);
+	INIT_LIST_HEAD(&se_sess->sess_cmd_list);
+	INIT_LIST_HEAD(&se_sess->sess_wait_list);
+	spin_lock_init(&se_sess->sess_cmd_lock);
+	kref_init(&se_sess->sess_kref);
+	se_sess->sup_prot_ops = sup_prot_ops;
+
+	return se_sess;
+}
+EXPORT_SYMBOL(transport_init_session);
+
+int transport_alloc_session_tags(struct se_session *se_sess,
+			         unsigned int tag_num, unsigned int tag_size)
+{
+	int rc;
+
+	se_sess->sess_cmd_map = kzalloc(tag_num * tag_size,
+					GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
+	if (!se_sess->sess_cmd_map) {
+		se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
+		if (!se_sess->sess_cmd_map) {
+			pr_err("Unable to allocate se_sess->sess_cmd_map\n");
+			return -ENOMEM;
+		}
+	}
+
+	rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
+	if (rc < 0) {
+		pr_err("Unable to init se_sess->sess_tag_pool,"
+			" tag_num: %u\n", tag_num);
+		if (is_vmalloc_addr(se_sess->sess_cmd_map))
+			vfree(se_sess->sess_cmd_map);
+		else
+			kfree(se_sess->sess_cmd_map);
+		se_sess->sess_cmd_map = NULL;
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(transport_alloc_session_tags);
+
+struct se_session *transport_init_session_tags(unsigned int tag_num,
+					       unsigned int tag_size,
+					       enum target_prot_op sup_prot_ops)
+{
+	struct se_session *se_sess;
+	int rc;
+
+	se_sess = transport_init_session(sup_prot_ops);
+	if (IS_ERR(se_sess))
+		return se_sess;
+
+	rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
+	if (rc < 0) {
+		transport_free_session(se_sess);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	return se_sess;
+}
+EXPORT_SYMBOL(transport_init_session_tags);
+
+/*
+ * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
+ */
+void __transport_register_session(
+	struct se_portal_group *se_tpg,
+	struct se_node_acl *se_nacl,
+	struct se_session *se_sess,
+	void *fabric_sess_ptr)
+{
+	const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
+	unsigned char buf[PR_REG_ISID_LEN];
+
+	se_sess->se_tpg = se_tpg;
+	se_sess->fabric_sess_ptr = fabric_sess_ptr;
+	/*
+	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
+	 *
+	 * Only set for struct se_session's that will actually be moving I/O.
+	 * eg: *NOT* discovery sessions.
+	 */
+	if (se_nacl) {
+		/*
+		 *
+		 * Determine if fabric allows for T10-PI feature bits exposed to
+		 * initiators for device backends with !dev->dev_attrib.pi_prot_type.
+		 *
+		 * If so, then always save prot_type on a per se_node_acl node
+		 * basis and re-instate the previous sess_prot_type to avoid
+		 * disabling PI from below any previously initiator side
+		 * registered LUNs.
+		 */
+		if (se_nacl->saved_prot_type)
+			se_sess->sess_prot_type = se_nacl->saved_prot_type;
+		else if (tfo->tpg_check_prot_fabric_only)
+			se_sess->sess_prot_type = se_nacl->saved_prot_type =
+					tfo->tpg_check_prot_fabric_only(se_tpg);
+		/*
+		 * If the fabric module supports an ISID based TransportID,
+		 * save this value in binary from the fabric I_T Nexus now.
+		 */
+		if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
+			memset(&buf[0], 0, PR_REG_ISID_LEN);
+			se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
+					&buf[0], PR_REG_ISID_LEN);
+			se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
+		}
+		kref_get(&se_nacl->acl_kref);
+
+		spin_lock_irq(&se_nacl->nacl_sess_lock);
+		/*
+		 * The se_nacl->nacl_sess pointer will be set to the
+		 * last active I_T Nexus for each struct se_node_acl.
+		 */
+		se_nacl->nacl_sess = se_sess;
+
+		list_add_tail(&se_sess->sess_acl_list,
+			      &se_nacl->acl_sess_list);
+		spin_unlock_irq(&se_nacl->nacl_sess_lock);
+	}
+	list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
+
+	pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
+		se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
+}
+EXPORT_SYMBOL(__transport_register_session);
+
+void transport_register_session(
+	struct se_portal_group *se_tpg,
+	struct se_node_acl *se_nacl,
+	struct se_session *se_sess,
+	void *fabric_sess_ptr)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&se_tpg->session_lock, flags);
+	__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
+	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
+}
+EXPORT_SYMBOL(transport_register_session);
+
+static void target_release_session(struct kref *kref)
+{
+	struct se_session *se_sess = container_of(kref,
+			struct se_session, sess_kref);
+	struct se_portal_group *se_tpg = se_sess->se_tpg;
+
+	se_tpg->se_tpg_tfo->close_session(se_sess);
+}
+
+void target_get_session(struct se_session *se_sess)
+{
+	kref_get(&se_sess->sess_kref);
+}
+EXPORT_SYMBOL(target_get_session);
+
+void target_put_session(struct se_session *se_sess)
+{
+	struct se_portal_group *tpg = se_sess->se_tpg;
+
+	if (tpg->se_tpg_tfo->put_session != NULL) {
+		tpg->se_tpg_tfo->put_session(se_sess);
+		return;
+	}
+	kref_put(&se_sess->sess_kref, target_release_session);
+}
+EXPORT_SYMBOL(target_put_session);
+
+ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
+{
+	struct se_session *se_sess;
+	ssize_t len = 0;
+
+	spin_lock_bh(&se_tpg->session_lock);
+	list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
+		if (!se_sess->se_node_acl)
+			continue;
+		if (!se_sess->se_node_acl->dynamic_node_acl)
+			continue;
+		if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
+			break;
+
+		len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
+				se_sess->se_node_acl->initiatorname);
+		len += 1; /* Include NULL terminator */
+	}
+	spin_unlock_bh(&se_tpg->session_lock);
+
+	return len;
+}
+EXPORT_SYMBOL(target_show_dynamic_sessions);
+
+static void target_complete_nacl(struct kref *kref)
+{
+	struct se_node_acl *nacl = container_of(kref,
+				struct se_node_acl, acl_kref);
+
+	complete(&nacl->acl_free_comp);
+}
+
+void target_put_nacl(struct se_node_acl *nacl)
+{
+	kref_put(&nacl->acl_kref, target_complete_nacl);
+}
+
+void transport_deregister_session_configfs(struct se_session *se_sess)
+{
+	struct se_node_acl *se_nacl;
+	unsigned long flags;
+	/*
+	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
+	 */
+	se_nacl = se_sess->se_node_acl;
+	if (se_nacl) {
+		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
+		if (se_nacl->acl_stop == 0)
+			list_del(&se_sess->sess_acl_list);
+		/*
+		 * If the session list is empty, then clear the pointer.
+		 * Otherwise, set the struct se_session pointer from the tail
+		 * element of the per struct se_node_acl active session list.
+		 */
+		if (list_empty(&se_nacl->acl_sess_list))
+			se_nacl->nacl_sess = NULL;
+		else {
+			se_nacl->nacl_sess = container_of(
+					se_nacl->acl_sess_list.prev,
+					struct se_session, sess_acl_list);
+		}
+		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
+	}
+}
+EXPORT_SYMBOL(transport_deregister_session_configfs);
+
+void transport_free_session(struct se_session *se_sess)
+{
+	if (se_sess->sess_cmd_map) {
+		percpu_ida_destroy(&se_sess->sess_tag_pool);
+		if (is_vmalloc_addr(se_sess->sess_cmd_map))
+			vfree(se_sess->sess_cmd_map);
+		else
+			kfree(se_sess->sess_cmd_map);
+	}
+	kmem_cache_free(se_sess_cache, se_sess);
+}
+EXPORT_SYMBOL(transport_free_session);
+
+void transport_deregister_session(struct se_session *se_sess)
+{
+	struct se_portal_group *se_tpg = se_sess->se_tpg;
+	const struct target_core_fabric_ops *se_tfo;
+	struct se_node_acl *se_nacl;
+	unsigned long flags;
+	bool comp_nacl = true;
+
+	if (!se_tpg) {
+		transport_free_session(se_sess);
+		return;
+	}
+	se_tfo = se_tpg->se_tpg_tfo;
+
+	spin_lock_irqsave(&se_tpg->session_lock, flags);
+	list_del(&se_sess->sess_list);
+	se_sess->se_tpg = NULL;
+	se_sess->fabric_sess_ptr = NULL;
+	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
+
+	/*
+	 * Determine if we need to do extra work for this initiator node's
+	 * struct se_node_acl if it had been previously dynamically generated.
+	 */
+	se_nacl = se_sess->se_node_acl;
+
+	spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
+	if (se_nacl && se_nacl->dynamic_node_acl) {
+		if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
+			list_del(&se_nacl->acl_list);
+			se_tpg->num_node_acls--;
+			spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
+			core_tpg_wait_for_nacl_pr_ref(se_nacl);
+			core_free_device_list_for_node(se_nacl, se_tpg);
+			se_tfo->tpg_release_fabric_acl(se_tpg, se_nacl);
+
+			comp_nacl = false;
+			spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
+		}
+	}
+	spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
+
+	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
+		se_tpg->se_tpg_tfo->get_fabric_name());
+	/*
+	 * If last kref is dropping now for an explicit NodeACL, awake sleeping
+	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
+	 * removal context.
+	 */
+	if (se_nacl && comp_nacl)
+		target_put_nacl(se_nacl);
+
+	transport_free_session(se_sess);
+}
+EXPORT_SYMBOL(transport_deregister_session);
+
+/*
+ * Called with cmd->t_state_lock held.
+ */
+static void target_remove_from_state_list(struct se_cmd *cmd)
+{
+	struct se_device *dev = cmd->se_dev;
+	unsigned long flags;
+
+	if (!dev)
+		return;
+
+	if (cmd->transport_state & CMD_T_BUSY)
+		return;
+
+	spin_lock_irqsave(&dev->execute_task_lock, flags);
+	if (cmd->state_active) {
+		list_del(&cmd->state_list);
+		cmd->state_active = false;
+	}
+	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
+}
+
+static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
+				    bool write_pending)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&cmd->t_state_lock, flags);
+	if (write_pending)
+		cmd->t_state = TRANSPORT_WRITE_PENDING;
+
+	if (remove_from_lists) {
+		target_remove_from_state_list(cmd);
+
+		/*
+		 * Clear struct se_cmd->se_lun before the handoff to FE.
+		 */
+		cmd->se_lun = NULL;
+	}
+
+	/*
+	 * Determine if frontend context caller is requesting the stopping of
+	 * this command for frontend exceptions.
+	 */
+	if (cmd->transport_state & CMD_T_STOP) {
+		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
+			__func__, __LINE__,
+			cmd->se_tfo->get_task_tag(cmd));
+
+		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+
+		complete_all(&cmd->t_transport_stop_comp);
+		return 1;
+	}
+
+	cmd->transport_state &= ~CMD_T_ACTIVE;
+	if (remove_from_lists) {
+		/*
+		 * Some fabric modules like tcm_loop can release
+		 * their internally allocated I/O reference now and
+		 * struct se_cmd now.
+		 *
+		 * Fabric modules are expected to return '1' here if the
+		 * se_cmd being passed is released at this point,
+		 * or zero if not being released.
+		 */
+		if (cmd->se_tfo->check_stop_free != NULL) {
+			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+			return cmd->se_tfo->check_stop_free(cmd);
+		}
+	}
+
+	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+	return 0;
+}
+
+static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
+{
+	return transport_cmd_check_stop(cmd, true, false);
+}
+
+static void transport_lun_remove_cmd(struct se_cmd *cmd)
+{
+	struct se_lun *lun = cmd->se_lun;
+
+	if (!lun)
+		return;
+
+	if (cmpxchg(&cmd->lun_ref_active, true, false))
+		percpu_ref_put(&lun->lun_ref);
+}
+
+void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
+{
+	if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
+		transport_lun_remove_cmd(cmd);
+	/*
+	 * Allow the fabric driver to unmap any resources before
+	 * releasing the descriptor via TFO->release_cmd()
+	 */
+	if (remove)
+		cmd->se_tfo->aborted_task(cmd);
+
+	if (transport_cmd_check_stop_to_fabric(cmd))
+		return;
+	if (remove)
+		transport_put_cmd(cmd);
+}
+
+static void target_complete_failure_work(struct work_struct *work)
+{
+	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
+
+	transport_generic_request_failure(cmd,
+			TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
+}
+
+/*
+ * Used when asking transport to copy Sense Data from the underlying
+ * Linux/SCSI struct scsi_cmnd
+ */
+static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
+{
+	struct se_device *dev = cmd->se_dev;
+
+	WARN_ON(!cmd->se_lun);
+
+	if (!dev)
+		return NULL;
+
+	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
+		return NULL;
+
+	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
+
+	pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
+		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
+	return cmd->sense_buffer;
+}
+
+void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
+{
+	struct se_device *dev = cmd->se_dev;
+	int success = scsi_status == GOOD;
+	unsigned long flags;
+
+	cmd->scsi_status = scsi_status;
+
+
+	spin_lock_irqsave(&cmd->t_state_lock, flags);
+	cmd->transport_state &= ~CMD_T_BUSY;
+
+	if (dev && dev->transport->transport_complete) {
+		dev->transport->transport_complete(cmd,
+				cmd->t_data_sg,
+				transport_get_sense_buffer(cmd));
+		if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
+			success = 1;
+	}
+
+	/*
+	 * See if we are waiting to complete for an exception condition.
+	 */
+	if (cmd->transport_state & CMD_T_REQUEST_STOP) {
+		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+		complete(&cmd->task_stop_comp);
+		return;
+	}
+
+	/*
+	 * Check for case where an explicit ABORT_TASK has been received
+	 * and transport_wait_for_tasks() will be waiting for completion..
+	 */
+	if (cmd->transport_state & CMD_T_ABORTED &&
+	    cmd->transport_state & CMD_T_STOP) {
+		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+		complete_all(&cmd->t_transport_stop_comp);
+		return;
+	} else if (!success) {
+		INIT_WORK(&cmd->work, target_complete_failure_work);
+	} else {
+		INIT_WORK(&cmd->work, target_complete_ok_work);
+	}
+
+	cmd->t_state = TRANSPORT_COMPLETE;
+	cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
+	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+
+	queue_work(target_completion_wq, &cmd->work);
+}
+EXPORT_SYMBOL(target_complete_cmd);
+
+void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
+{
+	if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
+		if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
+			cmd->residual_count += cmd->data_length - length;
+		} else {
+			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
+			cmd->residual_count = cmd->data_length - length;
+		}
+
+		cmd->data_length = length;
+	}
+
+	target_complete_cmd(cmd, scsi_status);
+}
+EXPORT_SYMBOL(target_complete_cmd_with_length);
+
+static void target_add_to_state_list(struct se_cmd *cmd)
+{
+	struct se_device *dev = cmd->se_dev;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->execute_task_lock, flags);
+	if (!cmd->state_active) {
+		list_add_tail(&cmd->state_list, &dev->state_list);
+		cmd->state_active = true;
+	}
+	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
+}
+
+/*
+ * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
+ */
+static void transport_write_pending_qf(struct se_cmd *cmd);
+static void transport_complete_qf(struct se_cmd *cmd);
+
+void target_qf_do_work(struct work_struct *work)
+{
+	struct se_device *dev = container_of(work, struct se_device,
+					qf_work_queue);
+	LIST_HEAD(qf_cmd_list);
+	struct se_cmd *cmd, *cmd_tmp;
+
+	spin_lock_irq(&dev->qf_cmd_lock);
+	list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
+	spin_unlock_irq(&dev->qf_cmd_lock);
+
+	list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
+		list_del(&cmd->se_qf_node);
+		atomic_dec_mb(&dev->dev_qf_count);
+
+		pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
+			" context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
+			(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
+			(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
+			: "UNKNOWN");
+
+		if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
+			transport_write_pending_qf(cmd);
+		else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
+			transport_complete_qf(cmd);
+	}
+}
+
+unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
+{
+	switch (cmd->data_direction) {
+	case DMA_NONE:
+		return "NONE";
+	case DMA_FROM_DEVICE:
+		return "READ";
+	case DMA_TO_DEVICE:
+		return "WRITE";
+	case DMA_BIDIRECTIONAL:
+		return "BIDI";
+	default:
+		break;
+	}
+
+	return "UNKNOWN";
+}
+
+void transport_dump_dev_state(
+	struct se_device *dev,
+	char *b,
+	int *bl)
+{
+	*bl += sprintf(b + *bl, "Status: ");
+	if (dev->export_count)
+		*bl += sprintf(b + *bl, "ACTIVATED");
+	else
+		*bl += sprintf(b + *bl, "DEACTIVATED");
+
+	*bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
+	*bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
+		dev->dev_attrib.block_size,
+		dev->dev_attrib.hw_max_sectors);
+	*bl += sprintf(b + *bl, "        ");
+}
+
+void transport_dump_vpd_proto_id(
+	struct t10_vpd *vpd,
+	unsigned char *p_buf,
+	int p_buf_len)
+{
+	unsigned char buf[VPD_TMP_BUF_SIZE];
+	int len;
+
+	memset(buf, 0, VPD_TMP_BUF_SIZE);
+	len = sprintf(buf, "T10 VPD Protocol Identifier: ");
+
+	switch (vpd->protocol_identifier) {
+	case 0x00:
+		sprintf(buf+len, "Fibre Channel\n");
+		break;
+	case 0x10:
+		sprintf(buf+len, "Parallel SCSI\n");
+		break;
+	case 0x20:
+		sprintf(buf+len, "SSA\n");
+		break;
+	case 0x30:
+		sprintf(buf+len, "IEEE 1394\n");
+		break;
+	case 0x40:
+		sprintf(buf+len, "SCSI Remote Direct Memory Access"
+				" Protocol\n");
+		break;
+	case 0x50:
+		sprintf(buf+len, "Internet SCSI (iSCSI)\n");
+		break;
+	case 0x60:
+		sprintf(buf+len, "SAS Serial SCSI Protocol\n");
+		break;
+	case 0x70:
+		sprintf(buf+len, "Automation/Drive Interface Transport"
+				" Protocol\n");
+		break;
+	case 0x80:
+		sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
+		break;
+	default:
+		sprintf(buf+len, "Unknown 0x%02x\n",
+				vpd->protocol_identifier);
+		break;
+	}
+
+	if (p_buf)
+		strncpy(p_buf, buf, p_buf_len);
+	else
+		pr_debug("%s", buf);
+}
+
+void
+transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
+{
+	/*
+	 * Check if the Protocol Identifier Valid (PIV) bit is set..
+	 *
+	 * from spc3r23.pdf section 7.5.1
+	 */
+	 if (page_83[1] & 0x80) {
+		vpd->protocol_identifier = (page_83[0] & 0xf0);
+		vpd->protocol_identifier_set = 1;
+		transport_dump_vpd_proto_id(vpd, NULL, 0);
+	}
+}
+EXPORT_SYMBOL(transport_set_vpd_proto_id);
+
+int transport_dump_vpd_assoc(
+	struct t10_vpd *vpd,
+	unsigned char *p_buf,
+	int p_buf_len)
+{
+	unsigned char buf[VPD_TMP_BUF_SIZE];
+	int ret = 0;
+	int len;
+
+	memset(buf, 0, VPD_TMP_BUF_SIZE);
+	len = sprintf(buf, "T10 VPD Identifier Association: ");
+
+	switch (vpd->association) {
+	case 0x00:
+		sprintf(buf+len, "addressed logical unit\n");
+		break;
+	case 0x10:
+		sprintf(buf+len, "target port\n");
+		break;
+	case 0x20:
+		sprintf(buf+len, "SCSI target device\n");
+		break;
+	default:
+		sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
+		ret = -EINVAL;
+		break;
+	}
+
+	if (p_buf)
+		strncpy(p_buf, buf, p_buf_len);
+	else
+		pr_debug("%s", buf);
+
+	return ret;
+}
+
+int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
+{
+	/*
+	 * The VPD identification association..
+	 *
+	 * from spc3r23.pdf Section 7.6.3.1 Table 297
+	 */
+	vpd->association = (page_83[1] & 0x30);
+	return transport_dump_vpd_assoc(vpd, NULL, 0);
+}
+EXPORT_SYMBOL(transport_set_vpd_assoc);
+
+int transport_dump_vpd_ident_type(
+	struct t10_vpd *vpd,
+	unsigned char *p_buf,
+	int p_buf_len)
+{
+	unsigned char buf[VPD_TMP_BUF_SIZE];
+	int ret = 0;
+	int len;
+
+	memset(buf, 0, VPD_TMP_BUF_SIZE);
+	len = sprintf(buf, "T10 VPD Identifier Type: ");
+
+	switch (vpd->device_identifier_type) {
+	case 0x00:
+		sprintf(buf+len, "Vendor specific\n");
+		break;
+	case 0x01:
+		sprintf(buf+len, "T10 Vendor ID based\n");
+		break;
+	case 0x02:
+		sprintf(buf+len, "EUI-64 based\n");
+		break;
+	case 0x03:
+		sprintf(buf+len, "NAA\n");
+		break;
+	case 0x04:
+		sprintf(buf+len, "Relative target port identifier\n");
+		break;
+	case 0x08:
+		sprintf(buf+len, "SCSI name string\n");
+		break;
+	default:
+		sprintf(buf+len, "Unsupported: 0x%02x\n",
+				vpd->device_identifier_type);
+		ret = -EINVAL;
+		break;
+	}
+
+	if (p_buf) {
+		if (p_buf_len < strlen(buf)+1)
+			return -EINVAL;
+		strncpy(p_buf, buf, p_buf_len);
+	} else {
+		pr_debug("%s", buf);
+	}
+
+	return ret;
+}
+
+int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
+{
+	/*
+	 * The VPD identifier type..
+	 *
+	 * from spc3r23.pdf Section 7.6.3.1 Table 298
+	 */
+	vpd->device_identifier_type = (page_83[1] & 0x0f);
+	return transport_dump_vpd_ident_type(vpd, NULL, 0);
+}
+EXPORT_SYMBOL(transport_set_vpd_ident_type);
+
+int transport_dump_vpd_ident(
+	struct t10_vpd *vpd,
+	unsigned char *p_buf,
+	int p_buf_len)
+{
+	unsigned char buf[VPD_TMP_BUF_SIZE];
+	int ret = 0;
+
+	memset(buf, 0, VPD_TMP_BUF_SIZE);
+
+	switch (vpd->device_identifier_code_set) {
+	case 0x01: /* Binary */
+		snprintf(buf, sizeof(buf),
+			"T10 VPD Binary Device Identifier: %s\n",
+			&vpd->device_identifier[0]);
+		break;
+	case 0x02: /* ASCII */
+		snprintf(buf, sizeof(buf),
+			"T10 VPD ASCII Device Identifier: %s\n",
+			&vpd->device_identifier[0]);
+		break;
+	case 0x03: /* UTF-8 */
+		snprintf(buf, sizeof(buf),
+			"T10 VPD UTF-8 Device Identifier: %s\n",
+			&vpd->device_identifier[0]);
+		break;
+	default:
+		sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
+			" 0x%02x", vpd->device_identifier_code_set);
+		ret = -EINVAL;
+		break;
+	}
+
+	if (p_buf)
+		strncpy(p_buf, buf, p_buf_len);
+	else
+		pr_debug("%s", buf);
+
+	return ret;
+}
+
+int
+transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
+{
+	static const char hex_str[] = "0123456789abcdef";
+	int j = 0, i = 4; /* offset to start of the identifier */
+
+	/*
+	 * The VPD Code Set (encoding)
+	 *
+	 * from spc3r23.pdf Section 7.6.3.1 Table 296
+	 */
+	vpd->device_identifier_code_set = (page_83[0] & 0x0f);
+	switch (vpd->device_identifier_code_set) {
+	case 0x01: /* Binary */
+		vpd->device_identifier[j++] =
+				hex_str[vpd->device_identifier_type];
+		while (i < (4 + page_83[3])) {
+			vpd->device_identifier[j++] =
+				hex_str[(page_83[i] & 0xf0) >> 4];
+			vpd->device_identifier[j++] =
+				hex_str[page_83[i] & 0x0f];
+			i++;
+		}
+		break;
+	case 0x02: /* ASCII */
+	case 0x03: /* UTF-8 */
+		while (i < (4 + page_83[3]))
+			vpd->device_identifier[j++] = page_83[i++];
+		break;
+	default:
+		break;
+	}
+
+	return transport_dump_vpd_ident(vpd, NULL, 0);
+}
+EXPORT_SYMBOL(transport_set_vpd_ident);
+
+sense_reason_t
+target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
+{
+	struct se_device *dev = cmd->se_dev;
+
+	if (cmd->unknown_data_length) {
+		cmd->data_length = size;
+	} else if (size != cmd->data_length) {
+		pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
+			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
+			" 0x%02x\n", cmd->se_tfo->get_fabric_name(),
+				cmd->data_length, size, cmd->t_task_cdb[0]);
+
+		if (cmd->data_direction == DMA_TO_DEVICE) {
+			pr_err("Rejecting underflow/overflow"
+					" WRITE data\n");
+			return TCM_INVALID_CDB_FIELD;
+		}
+		/*
+		 * Reject READ_* or WRITE_* with overflow/underflow for
+		 * type SCF_SCSI_DATA_CDB.
+		 */
+		if (dev->dev_attrib.block_size != 512)  {
+			pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
+				" CDB on non 512-byte sector setup subsystem"
+				" plugin: %s\n", dev->transport->name);
+			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
+			return TCM_INVALID_CDB_FIELD;
+		}
+		/*
+		 * For the overflow case keep the existing fabric provided
+		 * ->data_length.  Otherwise for the underflow case, reset
+		 * ->data_length to the smaller SCSI expected data transfer
+		 * length.
+		 */
+		if (size > cmd->data_length) {
+			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
+			cmd->residual_count = (size - cmd->data_length);
+		} else {
+			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
+			cmd->residual_count = (cmd->data_length - size);
+			cmd->data_length = size;
+		}
+	}
+
+	return 0;
+
+}
+
+/*
+ * Used by fabric modules containing a local struct se_cmd within their
+ * fabric dependent per I/O descriptor.
+ */
+void transport_init_se_cmd(
+	struct se_cmd *cmd,
+	const struct target_core_fabric_ops *tfo,
+	struct se_session *se_sess,
+	u32 data_length,
+	int data_direction,
+	int task_attr,
+	unsigned char *sense_buffer)
+{
+	INIT_LIST_HEAD(&cmd->se_delayed_node);
+	INIT_LIST_HEAD(&cmd->se_qf_node);
+	INIT_LIST_HEAD(&cmd->se_cmd_list);
+	INIT_LIST_HEAD(&cmd->state_list);
+	init_completion(&cmd->t_transport_stop_comp);
+	init_completion(&cmd->cmd_wait_comp);
+	init_completion(&cmd->task_stop_comp);
+	spin_lock_init(&cmd->t_state_lock);
+	kref_init(&cmd->cmd_kref);
+	cmd->transport_state = CMD_T_DEV_ACTIVE;
+
+	cmd->se_tfo = tfo;
+	cmd->se_sess = se_sess;
+	cmd->data_length = data_length;
+	cmd->data_direction = data_direction;
+	cmd->sam_task_attr = task_attr;
+	cmd->sense_buffer = sense_buffer;
+
+	cmd->state_active = false;
+}
+EXPORT_SYMBOL(transport_init_se_cmd);
+
+static sense_reason_t
+transport_check_alloc_task_attr(struct se_cmd *cmd)
+{
+	struct se_device *dev = cmd->se_dev;
+
+	/*
+	 * Check if SAM Task Attribute emulation is enabled for this
+	 * struct se_device storage object
+	 */
+	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
+		return 0;
+
+	if (cmd->sam_task_attr == TCM_ACA_TAG) {
+		pr_debug("SAM Task Attribute ACA"
+			" emulation is not supported\n");
+		return TCM_INVALID_CDB_FIELD;
+	}
+	/*
+	 * Used to determine when ORDERED commands should go from
+	 * Dormant to Active status.
+	 */
+	cmd->se_ordered_id = atomic_inc_return(&dev->dev_ordered_id);
+	pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
+			cmd->se_ordered_id, cmd->sam_task_attr,
+			dev->transport->name);
+	return 0;
+}
+
+sense_reason_t
+target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
+{
+	struct se_device *dev = cmd->se_dev;
+	sense_reason_t ret;
+
+	/*
+	 * Ensure that the received CDB is less than the max (252 + 8) bytes
+	 * for VARIABLE_LENGTH_CMD
+	 */
+	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
+		pr_err("Received SCSI CDB with command_size: %d that"
+			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
+			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
+		return TCM_INVALID_CDB_FIELD;
+	}
+	/*
+	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
+	 * allocate the additional extended CDB buffer now..  Otherwise
+	 * setup the pointer from __t_task_cdb to t_task_cdb.
+	 */
+	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
+		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
+						GFP_KERNEL);
+		if (!cmd->t_task_cdb) {
+			pr_err("Unable to allocate cmd->t_task_cdb"
+				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
+				scsi_command_size(cdb),
+				(unsigned long)sizeof(cmd->__t_task_cdb));
+			return TCM_OUT_OF_RESOURCES;
+		}
+	} else
+		cmd->t_task_cdb = &cmd->__t_task_cdb[0];
+	/*
+	 * Copy the original CDB into cmd->
+	 */
+	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
+
+	trace_target_sequencer_start(cmd);
+
+	/*
+	 * Check for an existing UNIT ATTENTION condition
+	 */
+	ret = target_scsi3_ua_check(cmd);
+	if (ret)
+		return ret;
+
+	ret = target_alua_state_check(cmd);
+	if (ret)
+		return ret;
+
+	ret = target_check_reservation(cmd);
+	if (ret) {
+		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
+		return ret;
+	}
+
+	ret = dev->transport->parse_cdb(cmd);
+	if (ret)
+		return ret;
+
+	ret = transport_check_alloc_task_attr(cmd);
+	if (ret)
+		return ret;
+
+	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
+
+	spin_lock(&cmd->se_lun->lun_sep_lock);
+	if (cmd->se_lun->lun_sep)
+		cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
+	spin_unlock(&cmd->se_lun->lun_sep_lock);
+	return 0;
+}
+EXPORT_SYMBOL(target_setup_cmd_from_cdb);
+
+/*
+ * Used by fabric module frontends to queue tasks directly.
+ * Many only be used from process context only
+ */
+int transport_handle_cdb_direct(
+	struct se_cmd *cmd)
+{
+	sense_reason_t ret;
+
+	if (!cmd->se_lun) {
+		dump_stack();
+		pr_err("cmd->se_lun is NULL\n");
+		return -EINVAL;
+	}
+	if (in_interrupt()) {
+		dump_stack();
+		pr_err("transport_generic_handle_cdb cannot be called"
+				" from interrupt context\n");
+		return -EINVAL;
+	}
+	/*
+	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
+	 * outstanding descriptors are handled correctly during shutdown via
+	 * transport_wait_for_tasks()
+	 *
+	 * Also, we don't take cmd->t_state_lock here as we only expect
+	 * this to be called for initial descriptor submission.
+	 */
+	cmd->t_state = TRANSPORT_NEW_CMD;
+	cmd->transport_state |= CMD_T_ACTIVE;
+
+	/*
+	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
+	 * so follow TRANSPORT_NEW_CMD processing thread context usage
+	 * and call transport_generic_request_failure() if necessary..
+	 */
+	ret = transport_generic_new_cmd(cmd);
+	if (ret)
+		transport_generic_request_failure(cmd, ret);
+	return 0;
+}
+EXPORT_SYMBOL(transport_handle_cdb_direct);
+
+sense_reason_t
+transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
+		u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
+{
+	if (!sgl || !sgl_count)
+		return 0;
+
+	/*
+	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
+	 * scatterlists already have been set to follow what the fabric
+	 * passes for the original expected data transfer length.
+	 */
+	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
+		pr_warn("Rejecting SCSI DATA overflow for fabric using"
+			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
+		return TCM_INVALID_CDB_FIELD;
+	}
+
+	cmd->t_data_sg = sgl;
+	cmd->t_data_nents = sgl_count;
+
+	if (sgl_bidi && sgl_bidi_count) {
+		cmd->t_bidi_data_sg = sgl_bidi;
+		cmd->t_bidi_data_nents = sgl_bidi_count;
+	}
+	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
+	return 0;
+}
+
+/*
+ * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
+ * 			 se_cmd + use pre-allocated SGL memory.
+ *
+ * @se_cmd: command descriptor to submit
+ * @se_sess: associated se_sess for endpoint
+ * @cdb: pointer to SCSI CDB
+ * @sense: pointer to SCSI sense buffer
+ * @unpacked_lun: unpacked LUN to reference for struct se_lun
+ * @data_length: fabric expected data transfer length
+ * @task_addr: SAM task attribute
+ * @data_dir: DMA data direction
+ * @flags: flags for command submission from target_sc_flags_tables
+ * @sgl: struct scatterlist memory for unidirectional mapping
+ * @sgl_count: scatterlist count for unidirectional mapping
+ * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
+ * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
+ * @sgl_prot: struct scatterlist memory protection information
+ * @sgl_prot_count: scatterlist count for protection information
+ *
+ * Returns non zero to signal active I/O shutdown failure.  All other
+ * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
+ * but still return zero here.
+ *
+ * This may only be called from process context, and also currently
+ * assumes internal allocation of fabric payload buffer by target-core.
+ */
+int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
+		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
+		u32 data_length, int task_attr, int data_dir, int flags,
+		struct scatterlist *sgl, u32 sgl_count,
+		struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
+		struct scatterlist *sgl_prot, u32 sgl_prot_count)
+{
+	struct se_portal_group *se_tpg;
+	sense_reason_t rc;
+	int ret;
+
+	se_tpg = se_sess->se_tpg;
+	BUG_ON(!se_tpg);
+	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
+	BUG_ON(in_interrupt());
+	/*
+	 * Initialize se_cmd for target operation.  From this point
+	 * exceptions are handled by sending exception status via
+	 * target_core_fabric_ops->queue_status() callback
+	 */
+	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
+				data_length, data_dir, task_attr, sense);
+	if (flags & TARGET_SCF_UNKNOWN_SIZE)
+		se_cmd->unknown_data_length = 1;
+	/*
+	 * Obtain struct se_cmd->cmd_kref reference and add new cmd to
+	 * se_sess->sess_cmd_list.  A second kref_get here is necessary
+	 * for fabrics using TARGET_SCF_ACK_KREF that expect a second
+	 * kref_put() to happen during fabric packet acknowledgement.
+	 */
+	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
+	if (ret)
+		return ret;
+	/*
+	 * Signal bidirectional data payloads to target-core
+	 */
+	if (flags & TARGET_SCF_BIDI_OP)
+		se_cmd->se_cmd_flags |= SCF_BIDI;
+	/*
+	 * Locate se_lun pointer and attach it to struct se_cmd
+	 */
+	rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
+	if (rc) {
+		transport_send_check_condition_and_sense(se_cmd, rc, 0);
+		target_put_sess_cmd(se_sess, se_cmd);
+		return 0;
+	}
+
+	rc = target_setup_cmd_from_cdb(se_cmd, cdb);
+	if (rc != 0) {
+		transport_generic_request_failure(se_cmd, rc);
+		return 0;
+	}
+
+	/*
+	 * Save pointers for SGLs containing protection information,
+	 * if present.
+	 */
+	if (sgl_prot_count) {
+		se_cmd->t_prot_sg = sgl_prot;
+		se_cmd->t_prot_nents = sgl_prot_count;
+	}
+
+	/*
+	 * When a non zero sgl_count has been passed perform SGL passthrough
+	 * mapping for pre-allocated fabric memory instead of having target
+	 * core perform an internal SGL allocation..
+	 */
+	if (sgl_count != 0) {
+		BUG_ON(!sgl);
+
+		/*
+		 * A work-around for tcm_loop as some userspace code via
+		 * scsi-generic do not memset their associated read buffers,
+		 * so go ahead and do that here for type non-data CDBs.  Also
+		 * note that this is currently guaranteed to be a single SGL
+		 * for this case by target core in target_setup_cmd_from_cdb()
+		 * -> transport_generic_cmd_sequencer().
+		 */
+		if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
+		     se_cmd->data_direction == DMA_FROM_DEVICE) {
+			unsigned char *buf = NULL;
+
+			if (sgl)
+				buf = kmap(sg_page(sgl)) + sgl->offset;
+
+			if (buf) {
+				memset(buf, 0, sgl->length);
+				kunmap(sg_page(sgl));
+			}
+		}
+
+		rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
+				sgl_bidi, sgl_bidi_count);
+		if (rc != 0) {
+			transport_generic_request_failure(se_cmd, rc);
+			return 0;
+		}
+	}
+
+	/*
+	 * Check if we need to delay processing because of ALUA
+	 * Active/NonOptimized primary access state..
+	 */
+	core_alua_check_nonop_delay(se_cmd);
+
+	transport_handle_cdb_direct(se_cmd);
+	return 0;
+}
+EXPORT_SYMBOL(target_submit_cmd_map_sgls);
+
+/*
+ * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
+ *
+ * @se_cmd: command descriptor to submit
+ * @se_sess: associated se_sess for endpoint
+ * @cdb: pointer to SCSI CDB
+ * @sense: pointer to SCSI sense buffer
+ * @unpacked_lun: unpacked LUN to reference for struct se_lun
+ * @data_length: fabric expected data transfer length
+ * @task_addr: SAM task attribute
+ * @data_dir: DMA data direction
+ * @flags: flags for command submission from target_sc_flags_tables
+ *
+ * Returns non zero to signal active I/O shutdown failure.  All other
+ * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
+ * but still return zero here.
+ *
+ * This may only be called from process context, and also currently
+ * assumes internal allocation of fabric payload buffer by target-core.
+ *
+ * It also assumes interal target core SGL memory allocation.
+ */
+int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
+		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
+		u32 data_length, int task_attr, int data_dir, int flags)
+{
+	return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
+			unpacked_lun, data_length, task_attr, data_dir,
+			flags, NULL, 0, NULL, 0, NULL, 0);
+}
+EXPORT_SYMBOL(target_submit_cmd);
+
+static void target_complete_tmr_failure(struct work_struct *work)
+{
+	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
+
+	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
+	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
+
+	transport_cmd_check_stop_to_fabric(se_cmd);
+}
+
+/**
+ * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
+ *                     for TMR CDBs
+ *
+ * @se_cmd: command descriptor to submit
+ * @se_sess: associated se_sess for endpoint
+ * @sense: pointer to SCSI sense buffer
+ * @unpacked_lun: unpacked LUN to reference for struct se_lun
+ * @fabric_context: fabric context for TMR req
+ * @tm_type: Type of TM request
+ * @gfp: gfp type for caller
+ * @tag: referenced task tag for TMR_ABORT_TASK
+ * @flags: submit cmd flags
+ *
+ * Callable from all contexts.
+ **/
+
+int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
+		unsigned char *sense, u32 unpacked_lun,
+		void *fabric_tmr_ptr, unsigned char tm_type,
+		gfp_t gfp, unsigned int tag, int flags)
+{
+	struct se_portal_group *se_tpg;
+	int ret;
+
+	se_tpg = se_sess->se_tpg;
+	BUG_ON(!se_tpg);
+
+	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
+			      0, DMA_NONE, TCM_SIMPLE_TAG, sense);
+	/*
+	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
+	 * allocation failure.
+	 */
+	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
+	if (ret < 0)
+		return -ENOMEM;
+
+	if (tm_type == TMR_ABORT_TASK)
+		se_cmd->se_tmr_req->ref_task_tag = tag;
+
+	/* See target_submit_cmd for commentary */
+	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
+	if (ret) {
+		core_tmr_release_req(se_cmd->se_tmr_req);
+		return ret;
+	}
+
+	ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
+	if (ret) {
+		/*
+		 * For callback during failure handling, push this work off
+		 * to process context with TMR_LUN_DOES_NOT_EXIST status.
+		 */
+		INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
+		schedule_work(&se_cmd->work);
+		return 0;
+	}
+	transport_generic_handle_tmr(se_cmd);
+	return 0;
+}
+EXPORT_SYMBOL(target_submit_tmr);
+
+/*
+ * If the cmd is active, request it to be stopped and sleep until it
+ * has completed.
+ */
+bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
+	__releases(&cmd->t_state_lock)
+	__acquires(&cmd->t_state_lock)
+{
+	bool was_active = false;
+
+	if (cmd->transport_state & CMD_T_BUSY) {
+		cmd->transport_state |= CMD_T_REQUEST_STOP;
+		spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
+
+		pr_debug("cmd %p waiting to complete\n", cmd);
+		wait_for_completion(&cmd->task_stop_comp);
+		pr_debug("cmd %p stopped successfully\n", cmd);
+
+		spin_lock_irqsave(&cmd->t_state_lock, *flags);
+		cmd->transport_state &= ~CMD_T_REQUEST_STOP;
+		cmd->transport_state &= ~CMD_T_BUSY;
+		was_active = true;
+	}
+
+	return was_active;
+}
+
+/*
+ * Handle SAM-esque emulation for generic transport request failures.
+ */
+void transport_generic_request_failure(struct se_cmd *cmd,
+		sense_reason_t sense_reason)
+{
+	int ret = 0;
+
+	pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
+		" CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
+		cmd->t_task_cdb[0]);
+	pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
+		cmd->se_tfo->get_cmd_state(cmd),
+		cmd->t_state, sense_reason);
+	pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
+		(cmd->transport_state & CMD_T_ACTIVE) != 0,
+		(cmd->transport_state & CMD_T_STOP) != 0,
+		(cmd->transport_state & CMD_T_SENT) != 0);
+
+	/*
+	 * For SAM Task Attribute emulation for failed struct se_cmd
+	 */
+	transport_complete_task_attr(cmd);
+	/*
+	 * Handle special case for COMPARE_AND_WRITE failure, where the
+	 * callback is expected to drop the per device ->caw_sem.
+	 */
+	if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
+	     cmd->transport_complete_callback)
+		cmd->transport_complete_callback(cmd, false);
+
+	switch (sense_reason) {
+	case TCM_NON_EXISTENT_LUN:
+	case TCM_UNSUPPORTED_SCSI_OPCODE:
+	case TCM_INVALID_CDB_FIELD:
+	case TCM_INVALID_PARAMETER_LIST:
+	case TCM_PARAMETER_LIST_LENGTH_ERROR:
+	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
+	case TCM_UNKNOWN_MODE_PAGE:
+	case TCM_WRITE_PROTECTED:
+	case TCM_ADDRESS_OUT_OF_RANGE:
+	case TCM_CHECK_CONDITION_ABORT_CMD:
+	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
+	case TCM_CHECK_CONDITION_NOT_READY:
+	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
+	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
+	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
+		break;
+	case TCM_OUT_OF_RESOURCES:
+		sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+		break;
+	case TCM_RESERVATION_CONFLICT:
+		/*
+		 * No SENSE Data payload for this case, set SCSI Status
+		 * and queue the response to $FABRIC_MOD.
+		 *
+		 * Uses linux/include/scsi/scsi.h SAM status codes defs
+		 */
+		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
+		/*
+		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
+		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
+		 * CONFLICT STATUS.
+		 *
+		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
+		 */
+		if (cmd->se_sess &&
+		    cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2)
+			core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
+				cmd->orig_fe_lun, 0x2C,
+				ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
+
+		trace_target_cmd_complete(cmd);
+		ret = cmd->se_tfo-> queue_status(cmd);
+		if (ret == -EAGAIN || ret == -ENOMEM)
+			goto queue_full;
+		goto check_stop;
+	default:
+		pr_err("Unknown transport error for CDB 0x%02x: %d\n",
+			cmd->t_task_cdb[0], sense_reason);
+		sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
+		break;
+	}
+
+	ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
+	if (ret == -EAGAIN || ret == -ENOMEM)
+		goto queue_full;
+
+check_stop:
+	transport_lun_remove_cmd(cmd);
+	if (!transport_cmd_check_stop_to_fabric(cmd))
+		;
+	return;
+
+queue_full:
+	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
+	transport_handle_queue_full(cmd, cmd->se_dev);
+}
+EXPORT_SYMBOL(transport_generic_request_failure);
+
+void __target_execute_cmd(struct se_cmd *cmd)
+{
+	sense_reason_t ret;
+
+	if (cmd->execute_cmd) {
+		ret = cmd->execute_cmd(cmd);
+		if (ret) {
+			spin_lock_irq(&cmd->t_state_lock);
+			cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
+			spin_unlock_irq(&cmd->t_state_lock);
+
+			transport_generic_request_failure(cmd, ret);
+		}
+	}
+}
+
+static int target_write_prot_action(struct se_cmd *cmd)
+{
+	u32 sectors;
+	/*
+	 * Perform WRITE_INSERT of PI using software emulation when backend
+	 * device has PI enabled, if the transport has not already generated
+	 * PI using hardware WRITE_INSERT offload.
+	 */
+	switch (cmd->prot_op) {
+	case TARGET_PROT_DOUT_INSERT:
+		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
+			sbc_dif_generate(cmd);
+		break;
+	case TARGET_PROT_DOUT_STRIP:
+		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
+			break;
+
+		sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
+		cmd->pi_err = sbc_dif_verify_write(cmd, cmd->t_task_lba,
+						   sectors, 0, NULL, 0);
+		if (unlikely(cmd->pi_err)) {
+			spin_lock_irq(&cmd->t_state_lock);
+			cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
+			spin_unlock_irq(&cmd->t_state_lock);
+			transport_generic_request_failure(cmd, cmd->pi_err);
+			return -1;
+		}
+		break;
+	default:
+		break;
+	}
+
+	return 0;
+}
+
+static bool target_handle_task_attr(struct se_cmd *cmd)
+{
+	struct se_device *dev = cmd->se_dev;
+
+	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
+		return false;
+
+	/*
+	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
+	 * to allow the passed struct se_cmd list of tasks to the front of the list.
+	 */
+	switch (cmd->sam_task_attr) {
+	case TCM_HEAD_TAG:
+		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
+			 "se_ordered_id: %u\n",
+			 cmd->t_task_cdb[0], cmd->se_ordered_id);
+		return false;
+	case TCM_ORDERED_TAG:
+		atomic_inc_mb(&dev->dev_ordered_sync);
+
+		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
+			 " se_ordered_id: %u\n",
+			 cmd->t_task_cdb[0], cmd->se_ordered_id);
+
+		/*
+		 * Execute an ORDERED command if no other older commands
+		 * exist that need to be completed first.
+		 */
+		if (!atomic_read(&dev->simple_cmds))
+			return false;
+		break;
+	default:
+		/*
+		 * For SIMPLE and UNTAGGED Task Attribute commands
+		 */
+		atomic_inc_mb(&dev->simple_cmds);
+		break;
+	}
+
+	if (atomic_read(&dev->dev_ordered_sync) == 0)
+		return false;
+
+	spin_lock(&dev->delayed_cmd_lock);
+	list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
+	spin_unlock(&dev->delayed_cmd_lock);
+
+	pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
+		" delayed CMD list, se_ordered_id: %u\n",
+		cmd->t_task_cdb[0], cmd->sam_task_attr,
+		cmd->se_ordered_id);
+	return true;
+}
+
+void target_execute_cmd(struct se_cmd *cmd)
+{
+	/*
+	 * If the received CDB has aleady been aborted stop processing it here.
+	 */
+	if (transport_check_aborted_status(cmd, 1))
+		return;
+
+	/*
+	 * Determine if frontend context caller is requesting the stopping of
+	 * this command for frontend exceptions.
+	 */
+	spin_lock_irq(&cmd->t_state_lock);
+	if (cmd->transport_state & CMD_T_STOP) {
+		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
+			__func__, __LINE__,
+			cmd->se_tfo->get_task_tag(cmd));
+
+		spin_unlock_irq(&cmd->t_state_lock);
+		complete_all(&cmd->t_transport_stop_comp);
+		return;
+	}
+
+	cmd->t_state = TRANSPORT_PROCESSING;
+	cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
+	spin_unlock_irq(&cmd->t_state_lock);
+
+	if (target_write_prot_action(cmd))
+		return;
+
+	if (target_handle_task_attr(cmd)) {
+		spin_lock_irq(&cmd->t_state_lock);
+		cmd->transport_state &= ~(CMD_T_BUSY | CMD_T_SENT);
+		spin_unlock_irq(&cmd->t_state_lock);
+		return;
+	}
+
+	__target_execute_cmd(cmd);
+}
+EXPORT_SYMBOL(target_execute_cmd);
+
+/*
+ * Process all commands up to the last received ORDERED task attribute which
+ * requires another blocking boundary
+ */
+static void target_restart_delayed_cmds(struct se_device *dev)
+{
+	for (;;) {
+		struct se_cmd *cmd;
+
+		spin_lock(&dev->delayed_cmd_lock);
+		if (list_empty(&dev->delayed_cmd_list)) {
+			spin_unlock(&dev->delayed_cmd_lock);
+			break;
+		}
+
+		cmd = list_entry(dev->delayed_cmd_list.next,
+				 struct se_cmd, se_delayed_node);
+		list_del(&cmd->se_delayed_node);
+		spin_unlock(&dev->delayed_cmd_lock);
+
+		__target_execute_cmd(cmd);
+
+		if (cmd->sam_task_attr == TCM_ORDERED_TAG)
+			break;
+	}
+}
+
+/*
+ * Called from I/O completion to determine which dormant/delayed
+ * and ordered cmds need to have their tasks added to the execution queue.
+ */
+static void transport_complete_task_attr(struct se_cmd *cmd)
+{
+	struct se_device *dev = cmd->se_dev;
+
+	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
+		return;
+
+	if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
+		atomic_dec_mb(&dev->simple_cmds);
+		dev->dev_cur_ordered_id++;
+		pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
+			" SIMPLE: %u\n", dev->dev_cur_ordered_id,
+			cmd->se_ordered_id);
+	} else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
+		dev->dev_cur_ordered_id++;
+		pr_debug("Incremented dev_cur_ordered_id: %u for"
+			" HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
+			cmd->se_ordered_id);
+	} else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
+		atomic_dec_mb(&dev->dev_ordered_sync);
+
+		dev->dev_cur_ordered_id++;
+		pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
+			" %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
+	}
+
+	target_restart_delayed_cmds(dev);
+}
+
+static void transport_complete_qf(struct se_cmd *cmd)
+{
+	int ret = 0;
+
+	transport_complete_task_attr(cmd);
+
+	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
+		trace_target_cmd_complete(cmd);
+		ret = cmd->se_tfo->queue_status(cmd);
+		goto out;
+	}
+
+	switch (cmd->data_direction) {
+	case DMA_FROM_DEVICE:
+		trace_target_cmd_complete(cmd);
+		ret = cmd->se_tfo->queue_data_in(cmd);
+		break;
+	case DMA_TO_DEVICE:
+		if (cmd->se_cmd_flags & SCF_BIDI) {
+			ret = cmd->se_tfo->queue_data_in(cmd);
+			break;
+		}
+		/* Fall through for DMA_TO_DEVICE */
+	case DMA_NONE:
+		trace_target_cmd_complete(cmd);
+		ret = cmd->se_tfo->queue_status(cmd);
+		break;
+	default:
+		break;
+	}
+
+out:
+	if (ret < 0) {
+		transport_handle_queue_full(cmd, cmd->se_dev);
+		return;
+	}
+	transport_lun_remove_cmd(cmd);
+	transport_cmd_check_stop_to_fabric(cmd);
+}
+
+static void transport_handle_queue_full(
+	struct se_cmd *cmd,
+	struct se_device *dev)
+{
+	spin_lock_irq(&dev->qf_cmd_lock);
+	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
+	atomic_inc_mb(&dev->dev_qf_count);
+	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
+
+	schedule_work(&cmd->se_dev->qf_work_queue);
+}
+
+static bool target_read_prot_action(struct se_cmd *cmd)
+{
+	sense_reason_t rc;
+
+	switch (cmd->prot_op) {
+	case TARGET_PROT_DIN_STRIP:
+		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
+			rc = sbc_dif_read_strip(cmd);
+			if (rc) {
+				cmd->pi_err = rc;
+				return true;
+			}
+		}
+		break;
+	case TARGET_PROT_DIN_INSERT:
+		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
+			break;
+
+		sbc_dif_generate(cmd);
+		break;
+	default:
+		break;
+	}
+
+	return false;
+}
+
+static void target_complete_ok_work(struct work_struct *work)
+{
+	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
+	int ret;
+
+	/*
+	 * Check if we need to move delayed/dormant tasks from cmds on the
+	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
+	 * Attribute.
+	 */
+	transport_complete_task_attr(cmd);
+
+	/*
+	 * Check to schedule QUEUE_FULL work, or execute an existing
+	 * cmd->transport_qf_callback()
+	 */
+	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
+		schedule_work(&cmd->se_dev->qf_work_queue);
+
+	/*
+	 * Check if we need to send a sense buffer from
+	 * the struct se_cmd in question.
+	 */
+	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
+		WARN_ON(!cmd->scsi_status);
+		ret = transport_send_check_condition_and_sense(
+					cmd, 0, 1);
+		if (ret == -EAGAIN || ret == -ENOMEM)
+			goto queue_full;
+
+		transport_lun_remove_cmd(cmd);
+		transport_cmd_check_stop_to_fabric(cmd);
+		return;
+	}
+	/*
+	 * Check for a callback, used by amongst other things
+	 * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
+	 */
+	if (cmd->transport_complete_callback) {
+		sense_reason_t rc;
+
+		rc = cmd->transport_complete_callback(cmd, true);
+		if (!rc && !(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE_POST)) {
+			if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
+			    !cmd->data_length)
+				goto queue_rsp;
+
+			return;
+		} else if (rc) {
+			ret = transport_send_check_condition_and_sense(cmd,
+						rc, 0);
+			if (ret == -EAGAIN || ret == -ENOMEM)
+				goto queue_full;
+
+			transport_lun_remove_cmd(cmd);
+			transport_cmd_check_stop_to_fabric(cmd);
+			return;
+		}
+	}
+
+queue_rsp:
+	switch (cmd->data_direction) {
+	case DMA_FROM_DEVICE:
+		spin_lock(&cmd->se_lun->lun_sep_lock);
+		if (cmd->se_lun->lun_sep) {
+			cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
+					cmd->data_length;
+		}
+		spin_unlock(&cmd->se_lun->lun_sep_lock);
+		/*
+		 * Perform READ_STRIP of PI using software emulation when
+		 * backend had PI enabled, if the transport will not be
+		 * performing hardware READ_STRIP offload.
+		 */
+		if (target_read_prot_action(cmd)) {
+			ret = transport_send_check_condition_and_sense(cmd,
+						cmd->pi_err, 0);
+			if (ret == -EAGAIN || ret == -ENOMEM)
+				goto queue_full;
+
+			transport_lun_remove_cmd(cmd);
+			transport_cmd_check_stop_to_fabric(cmd);
+			return;
+		}
+
+		trace_target_cmd_complete(cmd);
+		ret = cmd->se_tfo->queue_data_in(cmd);
+		if (ret == -EAGAIN || ret == -ENOMEM)
+			goto queue_full;
+		break;
+	case DMA_TO_DEVICE:
+		spin_lock(&cmd->se_lun->lun_sep_lock);
+		if (cmd->se_lun->lun_sep) {
+			cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
+				cmd->data_length;
+		}
+		spin_unlock(&cmd->se_lun->lun_sep_lock);
+		/*
+		 * Check if we need to send READ payload for BIDI-COMMAND
+		 */
+		if (cmd->se_cmd_flags & SCF_BIDI) {
+			spin_lock(&cmd->se_lun->lun_sep_lock);
+			if (cmd->se_lun->lun_sep) {
+				cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
+					cmd->data_length;
+			}
+			spin_unlock(&cmd->se_lun->lun_sep_lock);
+			ret = cmd->se_tfo->queue_data_in(cmd);
+			if (ret == -EAGAIN || ret == -ENOMEM)
+				goto queue_full;
+			break;
+		}
+		/* Fall through for DMA_TO_DEVICE */
+	case DMA_NONE:
+		trace_target_cmd_complete(cmd);
+		ret = cmd->se_tfo->queue_status(cmd);
+		if (ret == -EAGAIN || ret == -ENOMEM)
+			goto queue_full;
+		break;
+	default:
+		break;
+	}
+
+	transport_lun_remove_cmd(cmd);
+	transport_cmd_check_stop_to_fabric(cmd);
+	return;
+
+queue_full:
+	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
+		" data_direction: %d\n", cmd, cmd->data_direction);
+	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
+	transport_handle_queue_full(cmd, cmd->se_dev);
+}
+
+static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
+{
+	struct scatterlist *sg;
+	int count;
+
+	for_each_sg(sgl, sg, nents, count)
+		__free_page(sg_page(sg));
+
+	kfree(sgl);
+}
+
+static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
+{
+	/*
+	 * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
+	 * emulation, and free + reset pointers if necessary..
+	 */
+	if (!cmd->t_data_sg_orig)
+		return;
+
+	kfree(cmd->t_data_sg);
+	cmd->t_data_sg = cmd->t_data_sg_orig;
+	cmd->t_data_sg_orig = NULL;
+	cmd->t_data_nents = cmd->t_data_nents_orig;
+	cmd->t_data_nents_orig = 0;
+}
+
+static inline void transport_free_pages(struct se_cmd *cmd)
+{
+	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
+		/*
+		 * Release special case READ buffer payload required for
+		 * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
+		 */
+		if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
+			transport_free_sgl(cmd->t_bidi_data_sg,
+					   cmd->t_bidi_data_nents);
+			cmd->t_bidi_data_sg = NULL;
+			cmd->t_bidi_data_nents = 0;
+		}
+		transport_reset_sgl_orig(cmd);
+		return;
+	}
+	transport_reset_sgl_orig(cmd);
+
+	transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
+	cmd->t_data_sg = NULL;
+	cmd->t_data_nents = 0;
+
+	transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
+	cmd->t_bidi_data_sg = NULL;
+	cmd->t_bidi_data_nents = 0;
+
+	transport_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
+	cmd->t_prot_sg = NULL;
+	cmd->t_prot_nents = 0;
+}
+
+/**
+ * transport_release_cmd - free a command
+ * @cmd:       command to free
+ *
+ * This routine unconditionally frees a command, and reference counting
+ * or list removal must be done in the caller.
+ */
+static int transport_release_cmd(struct se_cmd *cmd)
+{
+	BUG_ON(!cmd->se_tfo);
+
+	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
+		core_tmr_release_req(cmd->se_tmr_req);
+	if (cmd->t_task_cdb != cmd->__t_task_cdb)
+		kfree(cmd->t_task_cdb);
+	/*
+	 * If this cmd has been setup with target_get_sess_cmd(), drop
+	 * the kref and call ->release_cmd() in kref callback.
+	 */
+	return target_put_sess_cmd(cmd->se_sess, cmd);
+}
+
+/**
+ * transport_put_cmd - release a reference to a command
+ * @cmd:       command to release
+ *
+ * This routine releases our reference to the command and frees it if possible.
+ */
+static int transport_put_cmd(struct se_cmd *cmd)
+{
+	transport_free_pages(cmd);
+	return transport_release_cmd(cmd);
+}
+
+void *transport_kmap_data_sg(struct se_cmd *cmd)
+{
+	struct scatterlist *sg = cmd->t_data_sg;
+	struct page **pages;
+	int i;
+
+	/*
+	 * We need to take into account a possible offset here for fabrics like
+	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
+	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
+	 */
+	if (!cmd->t_data_nents)
+		return NULL;
+
+	BUG_ON(!sg);
+	if (cmd->t_data_nents == 1)
+		return kmap(sg_page(sg)) + sg->offset;
+
+	/* >1 page. use vmap */
+	pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
+	if (!pages)
+		return NULL;
+
+	/* convert sg[] to pages[] */
+	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
+		pages[i] = sg_page(sg);
+	}
+
+	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
+	kfree(pages);
+	if (!cmd->t_data_vmap)
+		return NULL;
+
+	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
+}
+EXPORT_SYMBOL(transport_kmap_data_sg);
+
+void transport_kunmap_data_sg(struct se_cmd *cmd)
+{
+	if (!cmd->t_data_nents) {
+		return;
+	} else if (cmd->t_data_nents == 1) {
+		kunmap(sg_page(cmd->t_data_sg));
+		return;
+	}
+
+	vunmap(cmd->t_data_vmap);
+	cmd->t_data_vmap = NULL;
+}
+EXPORT_SYMBOL(transport_kunmap_data_sg);
+
+int
+target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
+		 bool zero_page)
+{
+	struct scatterlist *sg;
+	struct page *page;
+	gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
+	unsigned int nent;
+	int i = 0;
+
+	nent = DIV_ROUND_UP(length, PAGE_SIZE);
+	sg = kmalloc(sizeof(struct scatterlist) * nent, GFP_KERNEL);
+	if (!sg)
+		return -ENOMEM;
+
+	sg_init_table(sg, nent);
+
+	while (length) {
+		u32 page_len = min_t(u32, length, PAGE_SIZE);
+		page = alloc_page(GFP_KERNEL | zero_flag);
+		if (!page)
+			goto out;
+
+		sg_set_page(&sg[i], page, page_len, 0);
+		length -= page_len;
+		i++;
+	}
+	*sgl = sg;
+	*nents = nent;
+	return 0;
+
+out:
+	while (i > 0) {
+		i--;
+		__free_page(sg_page(&sg[i]));
+	}
+	kfree(sg);
+	return -ENOMEM;
+}
+
+/*
+ * Allocate any required resources to execute the command.  For writes we
+ * might not have the payload yet, so notify the fabric via a call to
+ * ->write_pending instead. Otherwise place it on the execution queue.
+ */
+sense_reason_t
+transport_generic_new_cmd(struct se_cmd *cmd)
+{
+	int ret = 0;
+	bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
+
+	/*
+	 * Determine is the TCM fabric module has already allocated physical
+	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
+	 * beforehand.
+	 */
+	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
+	    cmd->data_length) {
+
+		if ((cmd->se_cmd_flags & SCF_BIDI) ||
+		    (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
+			u32 bidi_length;
+
+			if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
+				bidi_length = cmd->t_task_nolb *
+					      cmd->se_dev->dev_attrib.block_size;
+			else
+				bidi_length = cmd->data_length;
+
+			ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
+					       &cmd->t_bidi_data_nents,
+					       bidi_length, zero_flag);
+			if (ret < 0)
+				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+		}
+
+		if (cmd->prot_op != TARGET_PROT_NORMAL) {
+			ret = target_alloc_sgl(&cmd->t_prot_sg,
+					       &cmd->t_prot_nents,
+					       cmd->prot_length, true);
+			if (ret < 0)
+				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+		}
+
+		ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
+				       cmd->data_length, zero_flag);
+		if (ret < 0)
+			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+	} else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
+		    cmd->data_length) {
+		/*
+		 * Special case for COMPARE_AND_WRITE with fabrics
+		 * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
+		 */
+		u32 caw_length = cmd->t_task_nolb *
+				 cmd->se_dev->dev_attrib.block_size;
+
+		ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
+				       &cmd->t_bidi_data_nents,
+				       caw_length, zero_flag);
+		if (ret < 0)
+			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+	}
+	/*
+	 * If this command is not a write we can execute it right here,
+	 * for write buffers we need to notify the fabric driver first
+	 * and let it call back once the write buffers are ready.
+	 */
+	target_add_to_state_list(cmd);
+	if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
+		target_execute_cmd(cmd);
+		return 0;
+	}
+	transport_cmd_check_stop(cmd, false, true);
+
+	ret = cmd->se_tfo->write_pending(cmd);
+	if (ret == -EAGAIN || ret == -ENOMEM)
+		goto queue_full;
+
+	/* fabric drivers should only return -EAGAIN or -ENOMEM as error */
+	WARN_ON(ret);
+
+	return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
+
+queue_full:
+	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
+	cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
+	transport_handle_queue_full(cmd, cmd->se_dev);
+	return 0;
+}
+EXPORT_SYMBOL(transport_generic_new_cmd);
+
+static void transport_write_pending_qf(struct se_cmd *cmd)
+{
+	int ret;
+
+	ret = cmd->se_tfo->write_pending(cmd);
+	if (ret == -EAGAIN || ret == -ENOMEM) {
+		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
+			 cmd);
+		transport_handle_queue_full(cmd, cmd->se_dev);
+	}
+}
+
+int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
+		if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
+			 transport_wait_for_tasks(cmd);
+
+		ret = transport_release_cmd(cmd);
+	} else {
+		if (wait_for_tasks)
+			transport_wait_for_tasks(cmd);
+		/*
+		 * Handle WRITE failure case where transport_generic_new_cmd()
+		 * has already added se_cmd to state_list, but fabric has
+		 * failed command before I/O submission.
+		 */
+		if (cmd->state_active) {
+			spin_lock_irqsave(&cmd->t_state_lock, flags);
+			target_remove_from_state_list(cmd);
+			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+		}
+
+		if (cmd->se_lun)
+			transport_lun_remove_cmd(cmd);
+
+		ret = transport_put_cmd(cmd);
+	}
+	return ret;
+}
+EXPORT_SYMBOL(transport_generic_free_cmd);
+
+/* target_get_sess_cmd - Add command to active ->sess_cmd_list
+ * @se_sess:	session to reference
+ * @se_cmd:	command descriptor to add
+ * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
+ */
+int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
+			       bool ack_kref)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	/*
+	 * Add a second kref if the fabric caller is expecting to handle
+	 * fabric acknowledgement that requires two target_put_sess_cmd()
+	 * invocations before se_cmd descriptor release.
+	 */
+	if (ack_kref)
+		kref_get(&se_cmd->cmd_kref);
+
+	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
+	if (se_sess->sess_tearing_down) {
+		ret = -ESHUTDOWN;
+		goto out;
+	}
+	list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
+out:
+	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
+
+	if (ret && ack_kref)
+		target_put_sess_cmd(se_sess, se_cmd);
+
+	return ret;
+}
+EXPORT_SYMBOL(target_get_sess_cmd);
+
+static void target_release_cmd_kref(struct kref *kref)
+		__releases(&se_cmd->se_sess->sess_cmd_lock)
+{
+	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
+	struct se_session *se_sess = se_cmd->se_sess;
+
+	if (list_empty(&se_cmd->se_cmd_list)) {
+		spin_unlock(&se_sess->sess_cmd_lock);
+		se_cmd->se_tfo->release_cmd(se_cmd);
+		return;
+	}
+	if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
+		spin_unlock(&se_sess->sess_cmd_lock);
+		complete(&se_cmd->cmd_wait_comp);
+		return;
+	}
+	list_del(&se_cmd->se_cmd_list);
+	spin_unlock(&se_sess->sess_cmd_lock);
+
+	se_cmd->se_tfo->release_cmd(se_cmd);
+}
+
+/* target_put_sess_cmd - Check for active I/O shutdown via kref_put
+ * @se_sess:	session to reference
+ * @se_cmd:	command descriptor to drop
+ */
+int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd)
+{
+	if (!se_sess) {
+		se_cmd->se_tfo->release_cmd(se_cmd);
+		return 1;
+	}
+	return kref_put_spinlock_irqsave(&se_cmd->cmd_kref, target_release_cmd_kref,
+			&se_sess->sess_cmd_lock);
+}
+EXPORT_SYMBOL(target_put_sess_cmd);
+
+/* target_sess_cmd_list_set_waiting - Flag all commands in
+ *         sess_cmd_list to complete cmd_wait_comp.  Set
+ *         sess_tearing_down so no more commands are queued.
+ * @se_sess:	session to flag
+ */
+void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
+{
+	struct se_cmd *se_cmd;
+	unsigned long flags;
+
+	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
+	if (se_sess->sess_tearing_down) {
+		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
+		return;
+	}
+	se_sess->sess_tearing_down = 1;
+	list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
+
+	list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list)
+		se_cmd->cmd_wait_set = 1;
+
+	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
+}
+EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
+
+/* target_wait_for_sess_cmds - Wait for outstanding descriptors
+ * @se_sess:    session to wait for active I/O
+ */
+void target_wait_for_sess_cmds(struct se_session *se_sess)
+{
+	struct se_cmd *se_cmd, *tmp_cmd;
+	unsigned long flags;
+
+	list_for_each_entry_safe(se_cmd, tmp_cmd,
+				&se_sess->sess_wait_list, se_cmd_list) {
+		list_del(&se_cmd->se_cmd_list);
+
+		pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
+			" %d\n", se_cmd, se_cmd->t_state,
+			se_cmd->se_tfo->get_cmd_state(se_cmd));
+
+		wait_for_completion(&se_cmd->cmd_wait_comp);
+		pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
+			" fabric state: %d\n", se_cmd, se_cmd->t_state,
+			se_cmd->se_tfo->get_cmd_state(se_cmd));
+
+		se_cmd->se_tfo->release_cmd(se_cmd);
+	}
+
+	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
+	WARN_ON(!list_empty(&se_sess->sess_cmd_list));
+	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
+
+}
+EXPORT_SYMBOL(target_wait_for_sess_cmds);
+
+static int transport_clear_lun_ref_thread(void *p)
+{
+	struct se_lun *lun = p;
+
+	percpu_ref_kill(&lun->lun_ref);
+
+	wait_for_completion(&lun->lun_ref_comp);
+	complete(&lun->lun_shutdown_comp);
+
+	return 0;
+}
+
+int transport_clear_lun_ref(struct se_lun *lun)
+{
+	struct task_struct *kt;
+
+	kt = kthread_run(transport_clear_lun_ref_thread, lun,
+			"tcm_cl_%u", lun->unpacked_lun);
+	if (IS_ERR(kt)) {
+		pr_err("Unable to start clear_lun thread\n");
+		return PTR_ERR(kt);
+	}
+	wait_for_completion(&lun->lun_shutdown_comp);
+
+	return 0;
+}
+
+/**
+ * transport_wait_for_tasks - wait for completion to occur
+ * @cmd:	command to wait
+ *
+ * Called from frontend fabric context to wait for storage engine
+ * to pause and/or release frontend generated struct se_cmd.
+ */
+bool transport_wait_for_tasks(struct se_cmd *cmd)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&cmd->t_state_lock, flags);
+	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
+	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
+		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+		return false;
+	}
+
+	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
+	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
+		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+		return false;
+	}
+
+	if (!(cmd->transport_state & CMD_T_ACTIVE)) {
+		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+		return false;
+	}
+
+	cmd->transport_state |= CMD_T_STOP;
+
+	pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
+		" i_state: %d, t_state: %d, CMD_T_STOP\n",
+		cmd, cmd->se_tfo->get_task_tag(cmd),
+		cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
+
+	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+
+	wait_for_completion(&cmd->t_transport_stop_comp);
+
+	spin_lock_irqsave(&cmd->t_state_lock, flags);
+	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
+
+	pr_debug("wait_for_tasks: Stopped wait_for_completion("
+		"&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
+		cmd->se_tfo->get_task_tag(cmd));
+
+	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+
+	return true;
+}
+EXPORT_SYMBOL(transport_wait_for_tasks);
+
+static int transport_get_sense_codes(
+	struct se_cmd *cmd,
+	u8 *asc,
+	u8 *ascq)
+{
+	*asc = cmd->scsi_asc;
+	*ascq = cmd->scsi_ascq;
+
+	return 0;
+}
+
+static
+void transport_err_sector_info(unsigned char *buffer, sector_t bad_sector)
+{
+	/* Place failed LBA in sense data information descriptor 0. */
+	buffer[SPC_ADD_SENSE_LEN_OFFSET] = 0xc;
+	buffer[SPC_DESC_TYPE_OFFSET] = 0; /* Information */
+	buffer[SPC_ADDITIONAL_DESC_LEN_OFFSET] = 0xa;
+	buffer[SPC_VALIDITY_OFFSET] = 0x80;
+
+	/* Descriptor Information: failing sector */
+	put_unaligned_be64(bad_sector, &buffer[12]);
+}
+
+int
+transport_send_check_condition_and_sense(struct se_cmd *cmd,
+		sense_reason_t reason, int from_transport)
+{
+	unsigned char *buffer = cmd->sense_buffer;
+	unsigned long flags;
+	u8 asc = 0, ascq = 0;
+
+	spin_lock_irqsave(&cmd->t_state_lock, flags);
+	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
+		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+		return 0;
+	}
+	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
+	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+
+	if (!reason && from_transport)
+		goto after_reason;
+
+	if (!from_transport)
+		cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
+
+	/*
+	 * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
+	 * SENSE KEY values from include/scsi/scsi.h
+	 */
+	switch (reason) {
+	case TCM_NO_SENSE:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		/* Not Ready */
+		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
+		/* NO ADDITIONAL SENSE INFORMATION */
+		buffer[SPC_ASC_KEY_OFFSET] = 0;
+		buffer[SPC_ASCQ_KEY_OFFSET] = 0;
+		break;
+	case TCM_NON_EXISTENT_LUN:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		/* ILLEGAL REQUEST */
+		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
+		/* LOGICAL UNIT NOT SUPPORTED */
+		buffer[SPC_ASC_KEY_OFFSET] = 0x25;
+		break;
+	case TCM_UNSUPPORTED_SCSI_OPCODE:
+	case TCM_SECTOR_COUNT_TOO_MANY:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		/* ILLEGAL REQUEST */
+		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
+		/* INVALID COMMAND OPERATION CODE */
+		buffer[SPC_ASC_KEY_OFFSET] = 0x20;
+		break;
+	case TCM_UNKNOWN_MODE_PAGE:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		/* ILLEGAL REQUEST */
+		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
+		/* INVALID FIELD IN CDB */
+		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
+		break;
+	case TCM_CHECK_CONDITION_ABORT_CMD:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		/* ABORTED COMMAND */
+		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
+		/* BUS DEVICE RESET FUNCTION OCCURRED */
+		buffer[SPC_ASC_KEY_OFFSET] = 0x29;
+		buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
+		break;
+	case TCM_INCORRECT_AMOUNT_OF_DATA:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		/* ABORTED COMMAND */
+		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
+		/* WRITE ERROR */
+		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
+		/* NOT ENOUGH UNSOLICITED DATA */
+		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0d;
+		break;
+	case TCM_INVALID_CDB_FIELD:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		/* ILLEGAL REQUEST */
+		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
+		/* INVALID FIELD IN CDB */
+		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
+		break;
+	case TCM_INVALID_PARAMETER_LIST:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		/* ILLEGAL REQUEST */
+		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
+		/* INVALID FIELD IN PARAMETER LIST */
+		buffer[SPC_ASC_KEY_OFFSET] = 0x26;
+		break;
+	case TCM_PARAMETER_LIST_LENGTH_ERROR:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		/* ILLEGAL REQUEST */
+		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
+		/* PARAMETER LIST LENGTH ERROR */
+		buffer[SPC_ASC_KEY_OFFSET] = 0x1a;
+		break;
+	case TCM_UNEXPECTED_UNSOLICITED_DATA:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		/* ABORTED COMMAND */
+		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
+		/* WRITE ERROR */
+		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
+		/* UNEXPECTED_UNSOLICITED_DATA */
+		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0c;
+		break;
+	case TCM_SERVICE_CRC_ERROR:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		/* ABORTED COMMAND */
+		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
+		/* PROTOCOL SERVICE CRC ERROR */
+		buffer[SPC_ASC_KEY_OFFSET] = 0x47;
+		/* N/A */
+		buffer[SPC_ASCQ_KEY_OFFSET] = 0x05;
+		break;
+	case TCM_SNACK_REJECTED:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		/* ABORTED COMMAND */
+		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
+		/* READ ERROR */
+		buffer[SPC_ASC_KEY_OFFSET] = 0x11;
+		/* FAILED RETRANSMISSION REQUEST */
+		buffer[SPC_ASCQ_KEY_OFFSET] = 0x13;
+		break;
+	case TCM_WRITE_PROTECTED:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		/* DATA PROTECT */
+		buffer[SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
+		/* WRITE PROTECTED */
+		buffer[SPC_ASC_KEY_OFFSET] = 0x27;
+		break;
+	case TCM_ADDRESS_OUT_OF_RANGE:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		/* ILLEGAL REQUEST */
+		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
+		/* LOGICAL BLOCK ADDRESS OUT OF RANGE */
+		buffer[SPC_ASC_KEY_OFFSET] = 0x21;
+		break;
+	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		/* UNIT ATTENTION */
+		buffer[SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
+		core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
+		buffer[SPC_ASC_KEY_OFFSET] = asc;
+		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
+		break;
+	case TCM_CHECK_CONDITION_NOT_READY:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		/* Not Ready */
+		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
+		transport_get_sense_codes(cmd, &asc, &ascq);
+		buffer[SPC_ASC_KEY_OFFSET] = asc;
+		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
+		break;
+	case TCM_MISCOMPARE_VERIFY:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		buffer[SPC_SENSE_KEY_OFFSET] = MISCOMPARE;
+		/* MISCOMPARE DURING VERIFY OPERATION */
+		buffer[SPC_ASC_KEY_OFFSET] = 0x1d;
+		buffer[SPC_ASCQ_KEY_OFFSET] = 0x00;
+		break;
+	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		/* ILLEGAL REQUEST */
+		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
+		/* LOGICAL BLOCK GUARD CHECK FAILED */
+		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
+		buffer[SPC_ASCQ_KEY_OFFSET] = 0x01;
+		transport_err_sector_info(buffer, cmd->bad_sector);
+		break;
+	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		/* ILLEGAL REQUEST */
+		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
+		/* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
+		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
+		buffer[SPC_ASCQ_KEY_OFFSET] = 0x02;
+		transport_err_sector_info(buffer, cmd->bad_sector);
+		break;
+	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		/* ILLEGAL REQUEST */
+		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
+		/* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
+		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
+		buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
+		transport_err_sector_info(buffer, cmd->bad_sector);
+		break;
+	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
+	default:
+		/* CURRENT ERROR */
+		buffer[0] = 0x70;
+		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
+		/*
+		 * Returning ILLEGAL REQUEST would cause immediate IO errors on
+		 * Solaris initiators.  Returning NOT READY instead means the
+		 * operations will be retried a finite number of times and we
+		 * can survive intermittent errors.
+		 */
+		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
+		/* LOGICAL UNIT COMMUNICATION FAILURE */
+		buffer[SPC_ASC_KEY_OFFSET] = 0x08;
+		break;
+	}
+	/*
+	 * This code uses linux/include/scsi/scsi.h SAM status codes!
+	 */
+	cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
+	/*
+	 * Automatically padded, this value is encoded in the fabric's
+	 * data_length response PDU containing the SCSI defined sense data.
+	 */
+	cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
+
+after_reason:
+	trace_target_cmd_complete(cmd);
+	return cmd->se_tfo->queue_status(cmd);
+}
+EXPORT_SYMBOL(transport_send_check_condition_and_sense);
+
+int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
+{
+	if (!(cmd->transport_state & CMD_T_ABORTED))
+		return 0;
+
+	/*
+	 * If cmd has been aborted but either no status is to be sent or it has
+	 * already been sent, just return
+	 */
+	if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS))
+		return 1;
+
+	pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08x\n",
+		 cmd->t_task_cdb[0], cmd->se_tfo->get_task_tag(cmd));
+
+	cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
+	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
+	trace_target_cmd_complete(cmd);
+	cmd->se_tfo->queue_status(cmd);
+
+	return 1;
+}
+EXPORT_SYMBOL(transport_check_aborted_status);
+
+void transport_send_task_abort(struct se_cmd *cmd)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&cmd->t_state_lock, flags);
+	if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
+		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+		return;
+	}
+	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+
+	/*
+	 * If there are still expected incoming fabric WRITEs, we wait
+	 * until until they have completed before sending a TASK_ABORTED
+	 * response.  This response with TASK_ABORTED status will be
+	 * queued back to fabric module by transport_check_aborted_status().
+	 */
+	if (cmd->data_direction == DMA_TO_DEVICE) {
+		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
+			cmd->transport_state |= CMD_T_ABORTED;
+			cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
+			return;
+		}
+	}
+	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
+
+	transport_lun_remove_cmd(cmd);
+
+	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
+		" ITT: 0x%08x\n", cmd->t_task_cdb[0],
+		cmd->se_tfo->get_task_tag(cmd));
+
+	trace_target_cmd_complete(cmd);
+	cmd->se_tfo->queue_status(cmd);
+}
+
+static void target_tmr_work(struct work_struct *work)
+{
+	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
+	struct se_device *dev = cmd->se_dev;
+	struct se_tmr_req *tmr = cmd->se_tmr_req;
+	int ret;
+
+	switch (tmr->function) {
+	case TMR_ABORT_TASK:
+		core_tmr_abort_task(dev, tmr, cmd->se_sess);
+		break;
+	case TMR_ABORT_TASK_SET:
+	case TMR_CLEAR_ACA:
+	case TMR_CLEAR_TASK_SET:
+		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
+		break;
+	case TMR_LUN_RESET:
+		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
+		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
+					 TMR_FUNCTION_REJECTED;
+		break;
+	case TMR_TARGET_WARM_RESET:
+		tmr->response = TMR_FUNCTION_REJECTED;
+		break;
+	case TMR_TARGET_COLD_RESET:
+		tmr->response = TMR_FUNCTION_REJECTED;
+		break;
+	default:
+		pr_err("Uknown TMR function: 0x%02x.\n",
+				tmr->function);
+		tmr->response = TMR_FUNCTION_REJECTED;
+		break;
+	}
+
+	cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
+	cmd->se_tfo->queue_tm_rsp(cmd);
+
+	transport_cmd_check_stop_to_fabric(cmd);
+}
+
+int transport_generic_handle_tmr(
+	struct se_cmd *cmd)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&cmd->t_state_lock, flags);
+	cmd->transport_state |= CMD_T_ACTIVE;
+	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
+
+	INIT_WORK(&cmd->work, target_tmr_work);
+	queue_work(cmd->se_dev->tmr_wq, &cmd->work);
+	return 0;
+}
+EXPORT_SYMBOL(transport_generic_handle_tmr);