text: // SPDX-License-Identifier: GPL-2.0-or-later
  /*******************************************************************************
   * This file contains main functions related to the iSCSI Target Core Driver.
   *
   * (c) Copyright 2007-2013 Datera, Inc.
   *
   * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
   *
   ******************************************************************************/
  
  #include <crypto/hash.h>
  #include <linux/string.h>
  #include <linux/kthread.h>
  #include <linux/completion.h>
  #include <linux/module.h>
  #include <linux/vmalloc.h>
  #include <linux/idr.h>
  #include <linux/delay.h>
  #include <linux/sched/signal.h>
  #include <asm/unaligned.h>
  #include <linux/inet.h>
  #include <net/ipv6.h>
  #include <scsi/scsi_proto.h>
  #include <scsi/iscsi_proto.h>
  #include <scsi/scsi_tcq.h>
  #include <target/target_core_base.h>
  #include <target/target_core_fabric.h>
  
  #include <target/iscsi/iscsi_target_core.h>
  #include "iscsi_target_parameters.h"
  #include "iscsi_target_seq_pdu_list.h"
  #include "iscsi_target_datain_values.h"
  #include "iscsi_target_erl0.h"
  #include "iscsi_target_erl1.h"
  #include "iscsi_target_erl2.h"
  #include "iscsi_target_login.h"
  #include "iscsi_target_tmr.h"
  #include "iscsi_target_tpg.h"
  #include "iscsi_target_util.h"
  #include "iscsi_target.h"
  #include "iscsi_target_device.h"
  #include <target/iscsi/iscsi_target_stat.h>
  
  #include <target/iscsi/iscsi_transport.h>
  
  static LIST_HEAD(g_tiqn_list);
  static LIST_HEAD(g_np_list);
  static DEFINE_SPINLOCK(tiqn_lock);
  static DEFINE_MUTEX(np_lock);
  
  static struct idr tiqn_idr;
  DEFINE_IDA(sess_ida);
  struct mutex auth_id_lock;
  
  struct iscsit_global *iscsit_global;
  
  struct kmem_cache *lio_qr_cache;
  struct kmem_cache *lio_dr_cache;
  struct kmem_cache *lio_ooo_cache;
  struct kmem_cache *lio_r2t_cache;
  
  static int iscsit_handle_immediate_data(struct iscsi_cmd *,
  			struct iscsi_scsi_req *, u32);
  
  struct iscsi_tiqn *iscsit_get_tiqn_for_login(unsigned char *buf)
  {
  	struct iscsi_tiqn *tiqn = NULL;
  
  	spin_lock(&tiqn_lock);
  	list_for_each_entry(tiqn, &g_tiqn_list, tiqn_list) {
  		if (!strcmp(tiqn->tiqn, buf)) {
  
  			spin_lock(&tiqn->tiqn_state_lock);
  			if (tiqn->tiqn_state == TIQN_STATE_ACTIVE) {
  				tiqn->tiqn_access_count++;
  				spin_unlock(&tiqn->tiqn_state_lock);
  				spin_unlock(&tiqn_lock);
  				return tiqn;
  			}
  			spin_unlock(&tiqn->tiqn_state_lock);
  		}
  	}
  	spin_unlock(&tiqn_lock);
  
  	return NULL;
  }
  
  static int iscsit_set_tiqn_shutdown(struct iscsi_tiqn *tiqn)
  {
  	spin_lock(&tiqn->tiqn_state_lock);
  	if (tiqn->tiqn_state == TIQN_STATE_ACTIVE) {
  		tiqn->tiqn_state = TIQN_STATE_SHUTDOWN;
  		spin_unlock(&tiqn->tiqn_state_lock);
  		return 0;
  	}
  	spin_unlock(&tiqn->tiqn_state_lock);
  
  	return -1;
  }
  
  void iscsit_put_tiqn_for_login(struct iscsi_tiqn *tiqn)
  {
  	spin_lock(&tiqn->tiqn_state_lock);
  	tiqn->tiqn_access_count--;
  	spin_unlock(&tiqn->tiqn_state_lock);
  }
  
  /*
   * Note that IQN formatting is expected to be done in userspace, and
   * no explict IQN format checks are done here.
   */
  struct iscsi_tiqn *iscsit_add_tiqn(unsigned char *buf)
  {
  	struct iscsi_tiqn *tiqn = NULL;
  	int ret;
  
  	if (strlen(buf) >= ISCSI_IQN_LEN) {
  		pr_err("Target IQN exceeds %d bytes\n",
  				ISCSI_IQN_LEN);
  		return ERR_PTR(-EINVAL);
  	}
  
  	tiqn = kzalloc(sizeof(*tiqn), GFP_KERNEL);
  	if (!tiqn)
  		return ERR_PTR(-ENOMEM);
  
  	sprintf(tiqn->tiqn, "%s", buf);
  	INIT_LIST_HEAD(&tiqn->tiqn_list);
  	INIT_LIST_HEAD(&tiqn->tiqn_tpg_list);
  	spin_lock_init(&tiqn->tiqn_state_lock);
  	spin_lock_init(&tiqn->tiqn_tpg_lock);
  	spin_lock_init(&tiqn->sess_err_stats.lock);
  	spin_lock_init(&tiqn->login_stats.lock);
  	spin_lock_init(&tiqn->logout_stats.lock);
  
  	tiqn->tiqn_state = TIQN_STATE_ACTIVE;
  
  	idr_preload(GFP_KERNEL);
  	spin_lock(&tiqn_lock);
  
  	ret = idr_alloc(&tiqn_idr, NULL, 0, 0, GFP_NOWAIT);
  	if (ret < 0) {
  		pr_err("idr_alloc() failed for tiqn->tiqn_index\n");
  		spin_unlock(&tiqn_lock);
  		idr_preload_end();
  		kfree(tiqn);
  		return ERR_PTR(ret);
  	}
  	tiqn->tiqn_index = ret;
  	list_add_tail(&tiqn->tiqn_list, &g_tiqn_list);
  
  	spin_unlock(&tiqn_lock);
  	idr_preload_end();
  
  	pr_debug("CORE[0] - Added iSCSI Target IQN: %s\n", tiqn->tiqn);
  
  	return tiqn;
  
  }
  
  static void iscsit_wait_for_tiqn(struct iscsi_tiqn *tiqn)
  {
  	/*
  	 * Wait for accesses to said struct iscsi_tiqn to end.
  	 */
  	spin_lock(&tiqn->tiqn_state_lock);
  	while (tiqn->tiqn_access_count != 0) {
  		spin_unlock(&tiqn->tiqn_state_lock);
  		msleep(10);
  		spin_lock(&tiqn->tiqn_state_lock);
  	}
  	spin_unlock(&tiqn->tiqn_state_lock);
  }
  
  void iscsit_del_tiqn(struct iscsi_tiqn *tiqn)
  {
  	/*
  	 * iscsit_set_tiqn_shutdown sets tiqn->tiqn_state = TIQN_STATE_SHUTDOWN
  	 * while holding tiqn->tiqn_state_lock.  This means that all subsequent
  	 * attempts to access this struct iscsi_tiqn will fail from both transport
  	 * fabric and control code paths.
  	 */
  	if (iscsit_set_tiqn_shutdown(tiqn) < 0) {
  		pr_err("iscsit_set_tiqn_shutdown() failed\n");
  		return;
  	}
  
  	iscsit_wait_for_tiqn(tiqn);
  
  	spin_lock(&tiqn_lock);
  	list_del(&tiqn->tiqn_list);
  	idr_remove(&tiqn_idr, tiqn->tiqn_index);
  	spin_unlock(&tiqn_lock);
  
  	pr_debug("CORE[0] - Deleted iSCSI Target IQN: %s\n",
  			tiqn->tiqn);
  	kfree(tiqn);
  }
  
  int iscsit_access_np(struct iscsi_np *np, struct iscsi_portal_group *tpg)
  {
  	int ret;
  	/*
  	 * Determine if the network portal is accepting storage traffic.
  	 */
  	spin_lock_bh(&np->np_thread_lock);
  	if (np->np_thread_state != ISCSI_NP_THREAD_ACTIVE) {
  		spin_unlock_bh(&np->np_thread_lock);
  		return -1;
  	}
  	spin_unlock_bh(&np->np_thread_lock);
  	/*
  	 * Determine if the portal group is accepting storage traffic.
  	 */
  	spin_lock_bh(&tpg->tpg_state_lock);
  	if (tpg->tpg_state != TPG_STATE_ACTIVE) {
  		spin_unlock_bh(&tpg->tpg_state_lock);
  		return -1;
  	}
  	spin_unlock_bh(&tpg->tpg_state_lock);
  
  	/*
  	 * Here we serialize access across the TIQN+TPG Tuple.
  	 */
  	ret = down_interruptible(&tpg->np_login_sem);
  	if (ret != 0)
  		return -1;
  
  	spin_lock_bh(&tpg->tpg_state_lock);
  	if (tpg->tpg_state != TPG_STATE_ACTIVE) {
  		spin_unlock_bh(&tpg->tpg_state_lock);
  		up(&tpg->np_login_sem);
  		return -1;
  	}
  	spin_unlock_bh(&tpg->tpg_state_lock);
  
  	return 0;
  }
  
  void iscsit_login_kref_put(struct kref *kref)
  {
  	struct iscsi_tpg_np *tpg_np = container_of(kref,
  				struct iscsi_tpg_np, tpg_np_kref);
  
  	complete(&tpg_np->tpg_np_comp);
  }
  
  int iscsit_deaccess_np(struct iscsi_np *np, struct iscsi_portal_group *tpg,
  		       struct iscsi_tpg_np *tpg_np)
  {
  	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
  
  	up(&tpg->np_login_sem);
  
  	if (tpg_np)
  		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
  
  	if (tiqn)
  		iscsit_put_tiqn_for_login(tiqn);
  
  	return 0;
  }
  
  bool iscsit_check_np_match(
  	struct sockaddr_storage *sockaddr,
  	struct iscsi_np *np,
  	int network_transport)
  {
  	struct sockaddr_in *sock_in, *sock_in_e;
  	struct sockaddr_in6 *sock_in6, *sock_in6_e;
  	bool ip_match = false;
  	u16 port, port_e;
  
  	if (sockaddr->ss_family == AF_INET6) {
  		sock_in6 = (struct sockaddr_in6 *)sockaddr;
  		sock_in6_e = (struct sockaddr_in6 *)&np->np_sockaddr;
  
  		if (!memcmp(&sock_in6->sin6_addr.in6_u,
  			    &sock_in6_e->sin6_addr.in6_u,
  			    sizeof(struct in6_addr)))
  			ip_match = true;
  
  		port = ntohs(sock_in6->sin6_port);
  		port_e = ntohs(sock_in6_e->sin6_port);
  	} else {
  		sock_in = (struct sockaddr_in *)sockaddr;
  		sock_in_e = (struct sockaddr_in *)&np->np_sockaddr;
  
  		if (sock_in->sin_addr.s_addr == sock_in_e->sin_addr.s_addr)
  			ip_match = true;
  
  		port = ntohs(sock_in->sin_port);
  		port_e = ntohs(sock_in_e->sin_port);
  	}
  
  	if (ip_match && (port_e == port) &&
  	    (np->np_network_transport == network_transport))
  		return true;
  
  	return false;
  }
  
  static struct iscsi_np *iscsit_get_np(
  	struct sockaddr_storage *sockaddr,
  	int network_transport)
  {
  	struct iscsi_np *np;
  	bool match;
  
  	lockdep_assert_held(&np_lock);
  
  	list_for_each_entry(np, &g_np_list, np_list) {
  		spin_lock_bh(&np->np_thread_lock);
  		if (np->np_thread_state != ISCSI_NP_THREAD_ACTIVE) {
  			spin_unlock_bh(&np->np_thread_lock);
  			continue;
  		}
  
  		match = iscsit_check_np_match(sockaddr, np, network_transport);
  		if (match) {
  			/*
  			 * Increment the np_exports reference count now to
  			 * prevent iscsit_del_np() below from being called
  			 * while iscsi_tpg_add_network_portal() is called.
  			 */
  			np->np_exports++;
  			spin_unlock_bh(&np->np_thread_lock);
  			return np;
  		}
  		spin_unlock_bh(&np->np_thread_lock);
  	}
  
  	return NULL;
  }
  
  struct iscsi_np *iscsit_add_np(
  	struct sockaddr_storage *sockaddr,
  	int network_transport)
  {
  	struct iscsi_np *np;
  	int ret;
  
  	mutex_lock(&np_lock);
  
  	/*
  	 * Locate the existing struct iscsi_np if already active..
  	 */
  	np = iscsit_get_np(sockaddr, network_transport);
  	if (np) {
  		mutex_unlock(&np_lock);
  		return np;
  	}
  
  	np = kzalloc(sizeof(*np), GFP_KERNEL);
  	if (!np) {
  		mutex_unlock(&np_lock);
  		return ERR_PTR(-ENOMEM);
  	}
  
  	np->np_flags |= NPF_IP_NETWORK;
  	np->np_network_transport = network_transport;
  	spin_lock_init(&np->np_thread_lock);
  	init_completion(&np->np_restart_comp);
  	INIT_LIST_HEAD(&np->np_list);
  
  	timer_setup(&np->np_login_timer, iscsi_handle_login_thread_timeout, 0);
  
  	ret = iscsi_target_setup_login_socket(np, sockaddr);
  	if (ret != 0) {
  		kfree(np);
  		mutex_unlock(&np_lock);
  		return ERR_PTR(ret);
  	}
  
  	np->np_thread = kthread_run(iscsi_target_login_thread, np, "iscsi_np");
  	if (IS_ERR(np->np_thread)) {
  		pr_err("Unable to create kthread: iscsi_np\n");
  		ret = PTR_ERR(np->np_thread);
  		kfree(np);
  		mutex_unlock(&np_lock);
  		return ERR_PTR(ret);
  	}
  	/*
  	 * Increment the np_exports reference count now to prevent
  	 * iscsit_del_np() below from being run while a new call to
  	 * iscsi_tpg_add_network_portal() for a matching iscsi_np is
  	 * active.  We don't need to hold np->np_thread_lock at this
  	 * point because iscsi_np has not been added to g_np_list yet.
  	 */
  	np->np_exports = 1;
  	np->np_thread_state = ISCSI_NP_THREAD_ACTIVE;
  
  	list_add_tail(&np->np_list, &g_np_list);
  	mutex_unlock(&np_lock);
  
  	pr_debug("CORE[0] - Added Network Portal: %pISpc on %s\n",
  		&np->np_sockaddr, np->np_transport->name);
  
  	return np;
  }
  
  int iscsit_reset_np_thread(
  	struct iscsi_np *np,
  	struct iscsi_tpg_np *tpg_np,
  	struct iscsi_portal_group *tpg,
  	bool shutdown)
  {
  	spin_lock_bh(&np->np_thread_lock);
  	if (np->np_thread_state == ISCSI_NP_THREAD_INACTIVE) {
  		spin_unlock_bh(&np->np_thread_lock);
  		return 0;
  	}
  	np->np_thread_state = ISCSI_NP_THREAD_RESET;
  	atomic_inc(&np->np_reset_count);
  
  	if (np->np_thread) {
  		spin_unlock_bh(&np->np_thread_lock);
  		send_sig(SIGINT, np->np_thread, 1);
  		wait_for_completion(&np->np_restart_comp);
  		spin_lock_bh(&np->np_thread_lock);
  	}
  	spin_unlock_bh(&np->np_thread_lock);
  
  	if (tpg_np && shutdown) {
  		kref_put(&tpg_np->tpg_np_kref, iscsit_login_kref_put);
  
  		wait_for_completion(&tpg_np->tpg_np_comp);
  	}
  
  	return 0;
  }
  
  static void iscsit_free_np(struct iscsi_np *np)
  {
  	if (np->np_socket)
  		sock_release(np->np_socket);
  }
  
  int iscsit_del_np(struct iscsi_np *np)
  {
  	spin_lock_bh(&np->np_thread_lock);
  	np->np_exports--;
  	if (np->np_exports) {
  		np->enabled = true;
  		spin_unlock_bh(&np->np_thread_lock);
  		return 0;
  	}
  	np->np_thread_state = ISCSI_NP_THREAD_SHUTDOWN;
  	spin_unlock_bh(&np->np_thread_lock);
  
  	if (np->np_thread) {
  		/*
  		 * We need to send the signal to wakeup Linux/Net
  		 * which may be sleeping in sock_accept()..
  		 */
  		send_sig(SIGINT, np->np_thread, 1);
  		kthread_stop(np->np_thread);
  		np->np_thread = NULL;
  	}
  
  	np->np_transport->iscsit_free_np(np);
  
  	mutex_lock(&np_lock);
  	list_del(&np->np_list);
  	mutex_unlock(&np_lock);
  
  	pr_debug("CORE[0] - Removed Network Portal: %pISpc on %s\n",
  		&np->np_sockaddr, np->np_transport->name);
  
  	iscsit_put_transport(np->np_transport);
  	kfree(np);
  	return 0;
  }
  
  static void iscsit_get_rx_pdu(struct iscsi_conn *);
  
  int iscsit_queue_rsp(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
  {
  	return iscsit_add_cmd_to_response_queue(cmd, cmd->conn, cmd->i_state);
  }
  EXPORT_SYMBOL(iscsit_queue_rsp);
  
  void iscsit_aborted_task(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
  {
  	spin_lock_bh(&conn->cmd_lock);
  	if (!list_empty(&cmd->i_conn_node) &&
  	    !(cmd->se_cmd.transport_state & CMD_T_FABRIC_STOP))
  		list_del_init(&cmd->i_conn_node);
  	spin_unlock_bh(&conn->cmd_lock);
  
  	__iscsit_free_cmd(cmd, true);
  }
  EXPORT_SYMBOL(iscsit_aborted_task);
  
  static void iscsit_do_crypto_hash_buf(struct ahash_request *, const void *,
  				      u32, u32, const void *, void *);
  static void iscsit_tx_thread_wait_for_tcp(struct iscsi_conn *);
  
  static int
  iscsit_xmit_nondatain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
  			  const void *data_buf, u32 data_buf_len)
  {
  	struct iscsi_hdr *hdr = (struct iscsi_hdr *)cmd->pdu;
  	struct kvec *iov;
  	u32 niov = 0, tx_size = ISCSI_HDR_LEN;
  	int ret;
  
  	iov = &cmd->iov_misc[0];
  	iov[niov].iov_base	= cmd->pdu;
  	iov[niov++].iov_len	= ISCSI_HDR_LEN;
  
  	if (conn->conn_ops->HeaderDigest) {
  		u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];
  
  		iscsit_do_crypto_hash_buf(conn->conn_tx_hash, hdr,
  					  ISCSI_HDR_LEN, 0, NULL,
  					  header_digest);
  
  		iov[0].iov_len += ISCSI_CRC_LEN;
  		tx_size += ISCSI_CRC_LEN;
  		pr_debug("Attaching CRC32C HeaderDigest"
  			 " to opcode 0x%x 0x%08x\n",
  			 hdr->opcode, *header_digest);
  	}
  
  	if (data_buf_len) {
  		u32 padding = ((-data_buf_len) & 3);
  
  		iov[niov].iov_base	= (void *)data_buf;
  		iov[niov++].iov_len	= data_buf_len;
  		tx_size += data_buf_len;
  
  		if (padding != 0) {
  			iov[niov].iov_base = &cmd->pad_bytes;
  			iov[niov++].iov_len = padding;
  			tx_size += padding;
  			pr_debug("Attaching %u additional"
  				 " padding bytes.\n", padding);
  		}
  
  		if (conn->conn_ops->DataDigest) {
  			iscsit_do_crypto_hash_buf(conn->conn_tx_hash,
  						  data_buf, data_buf_len,
  						  padding, &cmd->pad_bytes,
  						  &cmd->data_crc);
  
  			iov[niov].iov_base = &cmd->data_crc;
  			iov[niov++].iov_len = ISCSI_CRC_LEN;
  			tx_size += ISCSI_CRC_LEN;
  			pr_debug("Attached DataDigest for %u"
  				 " bytes opcode 0x%x, CRC 0x%08x\n",
  				 data_buf_len, hdr->opcode, cmd->data_crc);
  		}
  	}
  
  	cmd->iov_misc_count = niov;
  	cmd->tx_size = tx_size;
  
  	ret = iscsit_send_tx_data(cmd, conn, 1);
  	if (ret < 0) {
  		iscsit_tx_thread_wait_for_tcp(conn);
  		return ret;
  	}
  
  	return 0;
  }
  
  static int iscsit_map_iovec(struct iscsi_cmd *cmd, struct kvec *iov, int nvec,
  			    u32 data_offset, u32 data_length);
  static void iscsit_unmap_iovec(struct iscsi_cmd *);
  static u32 iscsit_do_crypto_hash_sg(struct ahash_request *, struct iscsi_cmd *,
  				    u32, u32, u32, u8 *);
  static int
  iscsit_xmit_datain_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
  		       const struct iscsi_datain *datain)
  {
  	struct kvec *iov;
  	u32 iov_count = 0, tx_size = 0;
  	int ret, iov_ret;
  
  	iov = &cmd->iov_data[0];
  	iov[iov_count].iov_base	= cmd->pdu;
  	iov[iov_count++].iov_len = ISCSI_HDR_LEN;
  	tx_size += ISCSI_HDR_LEN;
  
  	if (conn->conn_ops->HeaderDigest) {
  		u32 *header_digest = (u32 *)&cmd->pdu[ISCSI_HDR_LEN];
  
  		iscsit_do_crypto_hash_buf(conn->conn_tx_hash, cmd->pdu,
  					  ISCSI_HDR_LEN, 0, NULL,
  					  header_digest);
  
  		iov[0].iov_len += ISCSI_CRC_LEN;
  		tx_size += ISCSI_CRC_LEN;
  
  		pr_debug("Attaching CRC32 HeaderDigest for DataIN PDU 0x%08x\n",
  			 *header_digest);
  	}
  
  	iov_ret = iscsit_map_iovec(cmd, &cmd->iov_data[iov_count],
  				   cmd->orig_iov_data_count - (iov_count + 2),
  				   datain->offset, datain->length);
  	if (iov_ret < 0)
  		return -1;
  
  	iov_count += iov_ret;
  	tx_size += datain->length;
  
  	cmd->padding = ((-datain->length) & 3);
  	if (cmd->padding) {
  		iov[iov_count].iov_base		= cmd->pad_bytes;
  		iov[iov_count++].iov_len	= cmd->padding;
  		tx_size += cmd->padding;
  
  		pr_debug("Attaching %u padding bytes\n", cmd->padding);
  	}
  
  	if (conn->conn_ops->DataDigest) {
  		cmd->data_crc = iscsit_do_crypto_hash_sg(conn->conn_tx_hash,
  							 cmd, datain->offset,
  							 datain->length,
  							 cmd->padding,
  							 cmd->pad_bytes);
  
  		iov[iov_count].iov_base	= &cmd->data_crc;
  		iov[iov_count++].iov_len = ISCSI_CRC_LEN;
  		tx_size += ISCSI_CRC_LEN;
  
  		pr_debug("Attached CRC32C DataDigest %d bytes, crc 0x%08x\n",
  			 datain->length + cmd->padding, cmd->data_crc);
  	}
  
  	cmd->iov_data_count = iov_count;
  	cmd->tx_size = tx_size;
  
  	ret = iscsit_fe_sendpage_sg(cmd, conn);
  
  	iscsit_unmap_iovec(cmd);
  
  	if (ret < 0) {
  		iscsit_tx_thread_wait_for_tcp(conn);
  		return ret;
  	}
  
  	return 0;
  }
  
  static int iscsit_xmit_pdu(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
  			   struct iscsi_datain_req *dr, const void *buf,
  			   u32 buf_len)
  {
  	if (dr)
  		return iscsit_xmit_datain_pdu(conn, cmd, buf);
  	else
  		return iscsit_xmit_nondatain_pdu(conn, cmd, buf, buf_len);
  }
  
  static enum target_prot_op iscsit_get_sup_prot_ops(struct iscsi_conn *conn)
  {
  	return TARGET_PROT_NORMAL;
  }
  
  static struct iscsit_transport iscsi_target_transport = {
  	.name			= "iSCSI/TCP",
  	.transport_type		= ISCSI_TCP,
  	.rdma_shutdown		= false,
  	.owner			= NULL,
  	.iscsit_setup_np	= iscsit_setup_np,
  	.iscsit_accept_np	= iscsit_accept_np,
  	.iscsit_free_np		= iscsit_free_np,
  	.iscsit_get_login_rx	= iscsit_get_login_rx,
  	.iscsit_put_login_tx	= iscsit_put_login_tx,
  	.iscsit_get_dataout	= iscsit_build_r2ts_for_cmd,
  	.iscsit_immediate_queue	= iscsit_immediate_queue,
  	.iscsit_response_queue	= iscsit_response_queue,
  	.iscsit_queue_data_in	= iscsit_queue_rsp,
  	.iscsit_queue_status	= iscsit_queue_rsp,
  	.iscsit_aborted_task	= iscsit_aborted_task,
  	.iscsit_xmit_pdu	= iscsit_xmit_pdu,
  	.iscsit_get_rx_pdu	= iscsit_get_rx_pdu,
  	.iscsit_get_sup_prot_ops = iscsit_get_sup_prot_ops,
  };
  
  static int __init iscsi_target_init_module(void)
  {
  	int ret = 0, size;
  
  	pr_debug("iSCSI-Target "ISCSIT_VERSION"\n");
  	iscsit_global = kzalloc(sizeof(*iscsit_global), GFP_KERNEL);
  	if (!iscsit_global)
  		return -1;
  
  	spin_lock_init(&iscsit_global->ts_bitmap_lock);
  	mutex_init(&auth_id_lock);
  	idr_init(&tiqn_idr);
  
  	ret = target_register_template(&iscsi_ops);
  	if (ret)
  		goto out;
  
  	size = BITS_TO_LONGS(ISCSIT_BITMAP_BITS) * sizeof(long);
  	iscsit_global->ts_bitmap = vzalloc(size);
  	if (!iscsit_global->ts_bitmap)
  		goto configfs_out;
  
  	lio_qr_cache = kmem_cache_create("lio_qr_cache",
  			sizeof(struct iscsi_queue_req),
  			__alignof__(struct iscsi_queue_req), 0, NULL);
  	if (!lio_qr_cache) {
  		pr_err("Unable to kmem_cache_create() for"
  				" lio_qr_cache\n");
  		goto bitmap_out;
  	}
  
  	lio_dr_cache = kmem_cache_create("lio_dr_cache",
  			sizeof(struct iscsi_datain_req),
  			__alignof__(struct iscsi_datain_req), 0, NULL);
  	if (!lio_dr_cache) {
  		pr_err("Unable to kmem_cache_create() for"
  				" lio_dr_cache\n");
  		goto qr_out;
  	}
  
  	lio_ooo_cache = kmem_cache_create("lio_ooo_cache",
  			sizeof(struct iscsi_ooo_cmdsn),
  			__alignof__(struct iscsi_ooo_cmdsn), 0, NULL);
  	if (!lio_ooo_cache) {
  		pr_err("Unable to kmem_cache_create() for"
  				" lio_ooo_cache\n");
  		goto dr_out;
  	}
  
  	lio_r2t_cache = kmem_cache_create("lio_r2t_cache",
  			sizeof(struct iscsi_r2t), __alignof__(struct iscsi_r2t),
  			0, NULL);
  	if (!lio_r2t_cache) {
  		pr_err("Unable to kmem_cache_create() for"
  				" lio_r2t_cache\n");
  		goto ooo_out;
  	}
  
  	iscsit_register_transport(&iscsi_target_transport);
  
  	if (iscsit_load_discovery_tpg() < 0)
  		goto r2t_out;
  
  	return ret;
  r2t_out:
  	iscsit_unregister_transport(&iscsi_target_transport);
  	kmem_cache_destroy(lio_r2t_cache);
  ooo_out:
  	kmem_cache_destroy(lio_ooo_cache);
  dr_out:
  	kmem_cache_destroy(lio_dr_cache);
  qr_out:
  	kmem_cache_destroy(lio_qr_cache);
  bitmap_out:
  	vfree(iscsit_global->ts_bitmap);
  configfs_out:
  	/* XXX: this probably wants it to be it's own unwind step.. */
  	if (iscsit_global->discovery_tpg)
  		iscsit_tpg_disable_portal_group(iscsit_global->discovery_tpg, 1);
  	target_unregister_template(&iscsi_ops);
  out:
  	kfree(iscsit_global);
  	return -ENOMEM;
  }
  
  static void __exit iscsi_target_cleanup_module(void)
  {
  	iscsit_release_discovery_tpg();
  	iscsit_unregister_transport(&iscsi_target_transport);
  	kmem_cache_destroy(lio_qr_cache);
  	kmem_cache_destroy(lio_dr_cache);
  	kmem_cache_destroy(lio_ooo_cache);
  	kmem_cache_destroy(lio_r2t_cache);
  
  	/*
  	 * Shutdown discovery sessions and disable discovery TPG
  	 */
  	if (iscsit_global->discovery_tpg)
  		iscsit_tpg_disable_portal_group(iscsit_global->discovery_tpg, 1);
  
  	target_unregister_template(&iscsi_ops);
  
  	vfree(iscsit_global->ts_bitmap);
  	kfree(iscsit_global);
  }
  
  int iscsit_add_reject(
  	struct iscsi_conn *conn,
  	u8 reason,
  	unsigned char *buf)
  {
  	struct iscsi_cmd *cmd;
  
  	cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
  	if (!cmd)
  		return -1;
  
  	cmd->iscsi_opcode = ISCSI_OP_REJECT;
  	cmd->reject_reason = reason;
  
  	cmd->buf_ptr = kmemdup(buf, ISCSI_HDR_LEN, GFP_KERNEL);
  	if (!cmd->buf_ptr) {
  		pr_err("Unable to allocate memory for cmd->buf_ptr\n");
  		iscsit_free_cmd(cmd, false);
  		return -1;
  	}
  
  	spin_lock_bh(&conn->cmd_lock);
  	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
  	spin_unlock_bh(&conn->cmd_lock);
  
  	cmd->i_state = ISTATE_SEND_REJECT;
  	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
  
  	return -1;
  }
  EXPORT_SYMBOL(iscsit_add_reject);
  
  static int iscsit_add_reject_from_cmd(
  	struct iscsi_cmd *cmd,
  	u8 reason,
  	bool add_to_conn,
  	unsigned char *buf)
  {
  	struct iscsi_conn *conn;
  	const bool do_put = cmd->se_cmd.se_tfo != NULL;
  
  	if (!cmd->conn) {
  		pr_err("cmd->conn is NULL for ITT: 0x%08x\n",
  				cmd->init_task_tag);
  		return -1;
  	}
  	conn = cmd->conn;
  
  	cmd->iscsi_opcode = ISCSI_OP_REJECT;
  	cmd->reject_reason = reason;
  
  	cmd->buf_ptr = kmemdup(buf, ISCSI_HDR_LEN, GFP_KERNEL);
  	if (!cmd->buf_ptr) {
  		pr_err("Unable to allocate memory for cmd->buf_ptr\n");
  		iscsit_free_cmd(cmd, false);
  		return -1;
  	}
  
  	if (add_to_conn) {
  		spin_lock_bh(&conn->cmd_lock);
  		list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
  		spin_unlock_bh(&conn->cmd_lock);
  	}
  
  	cmd->i_state = ISTATE_SEND_REJECT;
  	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
  	/*
  	 * Perform the kref_put now if se_cmd has already been setup by
  	 * scsit_setup_scsi_cmd()
  	 */
  	if (do_put) {
  		pr_debug("iscsi reject: calling target_put_sess_cmd >>>>>>\n");
  		target_put_sess_cmd(&cmd->se_cmd);
  	}
  	return -1;
  }
  
  static int iscsit_add_reject_cmd(struct iscsi_cmd *cmd, u8 reason,
  				 unsigned char *buf)
  {
  	return iscsit_add_reject_from_cmd(cmd, reason, true, buf);
  }
  
  int iscsit_reject_cmd(struct iscsi_cmd *cmd, u8 reason, unsigned char *buf)
  {
  	return iscsit_add_reject_from_cmd(cmd, reason, false, buf);
  }
  EXPORT_SYMBOL(iscsit_reject_cmd);
  
  /*
   * Map some portion of the allocated scatterlist to an iovec, suitable for
   * kernel sockets to copy data in/out.
   */
  static int iscsit_map_iovec(struct iscsi_cmd *cmd, struct kvec *iov, int nvec,
  			    u32 data_offset, u32 data_length)
  {
  	u32 i = 0, orig_data_length = data_length;
  	struct scatterlist *sg;
  	unsigned int page_off;
  
  	/*
  	 * We know each entry in t_data_sg contains a page.
  	 */
  	u32 ent = data_offset / PAGE_SIZE;
  
  	if (!data_length)
  		return 0;
  
  	if (ent >= cmd->se_cmd.t_data_nents) {
  		pr_err("Initial page entry out-of-bounds\n");
  		goto overflow;
  	}
  
  	sg = &cmd->se_cmd.t_data_sg[ent];
  	page_off = (data_offset % PAGE_SIZE);
  
  	cmd->first_data_sg = sg;
  	cmd->first_data_sg_off = page_off;
  
  	while (data_length) {
  		u32 cur_len;
  
  		if (WARN_ON_ONCE(!sg || i >= nvec))
  			goto overflow;
  
  		cur_len = min_t(u32, data_length, sg->length - page_off);
  
  		iov[i].iov_base = kmap(sg_page(sg)) + sg->offset + page_off;
  		iov[i].iov_len = cur_len;
  
  		data_length -= cur_len;
  		page_off = 0;
  		sg = sg_next(sg);
  		i++;
  	}
  
  	cmd->kmapped_nents = i;
  
  	return i;
  
  overflow:
  	pr_err("offset %d + length %d overflow; %d/%d; sg-list:\n",
  	       data_offset, orig_data_length, i, nvec);
  	for_each_sg(cmd->se_cmd.t_data_sg, sg,
  		    cmd->se_cmd.t_data_nents, i) {
  		pr_err("[%d] off %d len %d\n",
  		       i, sg->offset, sg->length);
  	}
  	return -1;
  }
  
  static void iscsit_unmap_iovec(struct iscsi_cmd *cmd)
  {
  	u32 i;
  	struct scatterlist *sg;
  
  	sg = cmd->first_data_sg;
  
  	for (i = 0; i < cmd->kmapped_nents; i++)
  		kunmap(sg_page(&sg[i]));
  }
  
  static void iscsit_ack_from_expstatsn(struct iscsi_conn *conn, u32 exp_statsn)
  {
  	LIST_HEAD(ack_list);
  	struct iscsi_cmd *cmd, *cmd_p;
  
  	conn->exp_statsn = exp_statsn;
  
  	if (conn->sess->sess_ops->RDMAExtensions)
  		return;
  
  	spin_lock_bh(&conn->cmd_lock);
  	list_for_each_entry_safe(cmd, cmd_p, &conn->conn_cmd_list, i_conn_node) {
  		spin_lock(&cmd->istate_lock);
  		if ((cmd->i_state == ISTATE_SENT_STATUS) &&
  		    iscsi_sna_lt(cmd->stat_sn, exp_statsn)) {
  			cmd->i_state = ISTATE_REMOVE;
  			spin_unlock(&cmd->istate_lock);
  			list_move_tail(&cmd->i_conn_node, &ack_list);
  			continue;
  		}
  		spin_unlock(&cmd->istate_lock);
  	}
  	spin_unlock_bh(&conn->cmd_lock);
  
  	list_for_each_entry_safe(cmd, cmd_p, &ack_list, i_conn_node) {
  		list_del_init(&cmd->i_conn_node);
  		iscsit_free_cmd(cmd, false);
  	}
  }
  
  static int iscsit_allocate_iovecs(struct iscsi_cmd *cmd)
  {
  	u32 iov_count = max(1UL, DIV_ROUND_UP(cmd->se_cmd.data_length, PAGE_SIZE));
  
  	iov_count += ISCSI_IOV_DATA_BUFFER;
  	cmd->iov_data = kcalloc(iov_count, sizeof(*cmd->iov_data), GFP_KERNEL);
  	if (!cmd->iov_data)
  		return -ENOMEM;
  
  	cmd->orig_iov_data_count = iov_count;
  	return 0;
  }
  
  int iscsit_setup_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
  			  unsigned char *buf)
  {
  	int data_direction, payload_length;
  	struct iscsi_scsi_req *hdr;
  	int iscsi_task_attr;
  	int sam_task_attr;
  
  	atomic_long_inc(&conn->sess->cmd_pdus);
  
  	hdr			= (struct iscsi_scsi_req *) buf;
  	payload_length		= ntoh24(hdr->dlength);
  
  	/* FIXME; Add checks for AdditionalHeaderSegment */
  
  	if (!(hdr->flags & ISCSI_FLAG_CMD_WRITE) &&
  	    !(hdr->flags & ISCSI_FLAG_CMD_FINAL)) {
  		pr_err("ISCSI_FLAG_CMD_WRITE & ISCSI_FLAG_CMD_FINAL"
  				" not set. Bad iSCSI Initiator.\n");
  		return iscsit_add_reject_cmd(cmd,
  					     ISCSI_REASON_BOOKMARK_INVALID, buf);
  	}
  
  	if (((hdr->flags & ISCSI_FLAG_CMD_READ) ||
  	     (hdr->flags & ISCSI_FLAG_CMD_WRITE)) && !hdr->data_length) {
  		/*
  		 * From RFC-3720 Section 10.3.1:
  		 *
  		 * "Either or both of R and W MAY be 1 when either the
  		 *  Expected Data Transfer Length and/or Bidirectional Read
  		 *  Expected Data Transfer Length are 0"
  		 *
  		 * For this case, go ahead and clear the unnecssary bits
  		 * to avoid any confusion with ->data_direction.
  		 */
  		hdr->flags &= ~ISCSI_FLAG_CMD_READ;
  		hdr->flags &= ~ISCSI_FLAG_CMD_WRITE;
  
  		pr_warn("ISCSI_FLAG_CMD_READ or ISCSI_FLAG_CMD_WRITE"
  			" set when Expected Data Transfer Length is 0 for"
  			" CDB: 0x%02x, Fixing up flags\n", hdr->cdb[0]);
  	}
  
  	if (!(hdr->flags & ISCSI_FLAG_CMD_READ) &&
  	    !(hdr->flags & ISCSI_FLAG_CMD_WRITE) && (hdr->data_length != 0)) {
  		pr_err("ISCSI_FLAG_CMD_READ and/or ISCSI_FLAG_CMD_WRITE"
  			" MUST be set if Expected Data Transfer Length is not 0."
  			" Bad iSCSI Initiator\n");
  		return iscsit_add_reject_cmd(cmd,
  					     ISCSI_REASON_BOOKMARK_INVALID, buf);
  	}
  
  	if ((hdr->flags & ISCSI_FLAG_CMD_READ) &&
  	    (hdr->flags & ISCSI_FLAG_CMD_WRITE)) {
  		pr_err("Bidirectional operations not supported!\n");
  		return iscsit_add_reject_cmd(cmd,
  					     ISCSI_REASON_BOOKMARK_INVALID, buf);
  	}
  
  	if (hdr->opcode & ISCSI_OP_IMMEDIATE) {
  		pr_err("Illegally set Immediate Bit in iSCSI Initiator"
  				" Scsi Command PDU.\n");
  		return iscsit_add_reject_cmd(cmd,
  					     ISCSI_REASON_BOOKMARK_INVALID, buf);
  	}
  
  	if (payload_length && !conn->sess->sess_ops->ImmediateData) {
  		pr_err("ImmediateData=No but DataSegmentLength=%u,"
  			" protocol error.\n", payload_length);
  		return iscsit_add_reject_cmd(cmd,
  					     ISCSI_REASON_PROTOCOL_ERROR, buf);
  	}
  
  	if ((be32_to_cpu(hdr->data_length) == payload_length) &&
  	    (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))) {
  		pr_err("Expected Data Transfer Length and Length of"
  			" Immediate Data are the same, but ISCSI_FLAG_CMD_FINAL"
  			" bit is not set protocol error\n");
  		return iscsit_add_reject_cmd(cmd,
  					     ISCSI_REASON_PROTOCOL_ERROR, buf);
  	}
  
  	if (payload_length > be32_to_cpu(hdr->data_length)) {
  		pr_err("DataSegmentLength: %u is greater than"
  			" EDTL: %u, protocol error.\n", payload_length,
  				hdr->data_length);
  		return iscsit_add_reject_cmd(cmd,
  					     ISCSI_REASON_PROTOCOL_ERROR, buf);
  	}
  
  	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
  		pr_err("DataSegmentLength: %u is greater than"
  			" MaxXmitDataSegmentLength: %u, protocol error.\n",
  			payload_length, conn->conn_ops->MaxXmitDataSegmentLength);
  		return iscsit_add_reject_cmd(cmd,
  					     ISCSI_REASON_PROTOCOL_ERROR, buf);
  	}
  
  	if (payload_length > conn->sess->sess_ops->FirstBurstLength) {
  		pr_err("DataSegmentLength: %u is greater than"
  			" FirstBurstLength: %u, protocol error.\n",
  			payload_length, conn->sess->sess_ops->FirstBurstLength);
  		return iscsit_add_reject_cmd(cmd,
  					     ISCSI_REASON_BOOKMARK_INVALID, buf);
  	}
  
  	data_direction = (hdr->flags & ISCSI_FLAG_CMD_WRITE) ? DMA_TO_DEVICE :
  			 (hdr->flags & ISCSI_FLAG_CMD_READ) ? DMA_FROM_DEVICE :
  			  DMA_NONE;
  
  	cmd->data_direction = data_direction;
  	iscsi_task_attr = hdr->flags & ISCSI_FLAG_CMD_ATTR_MASK;
  	/*
  	 * Figure out the SAM Task Attribute for the incoming SCSI CDB
  	 */
  	if ((iscsi_task_attr == ISCSI_ATTR_UNTAGGED) ||
  	    (iscsi_task_attr == ISCSI_ATTR_SIMPLE))
  		sam_task_attr = TCM_SIMPLE_TAG;
  	else if (iscsi_task_attr == ISCSI_ATTR_ORDERED)
  		sam_task_attr = TCM_ORDERED_TAG;
  	else if (iscsi_task_attr == ISCSI_ATTR_HEAD_OF_QUEUE)
  		sam_task_attr = TCM_HEAD_TAG;
  	else if (iscsi_task_attr == ISCSI_ATTR_ACA)
  		sam_task_attr = TCM_ACA_TAG;
  	else {
  		pr_debug("Unknown iSCSI Task Attribute: 0x%02x, using"
  			" TCM_SIMPLE_TAG\n", iscsi_task_attr);
  		sam_task_attr = TCM_SIMPLE_TAG;
  	}
  
  	cmd->iscsi_opcode	= ISCSI_OP_SCSI_CMD;
  	cmd->i_state		= ISTATE_NEW_CMD;
  	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
  	cmd->immediate_data	= (payload_length) ? 1 : 0;
  	cmd->unsolicited_data	= ((!(hdr->flags & ISCSI_FLAG_CMD_FINAL) &&
  				     (hdr->flags & ISCSI_FLAG_CMD_WRITE)) ? 1 : 0);
  	if (cmd->unsolicited_data)
  		cmd->cmd_flags |= ICF_NON_IMMEDIATE_UNSOLICITED_DATA;
  
  	conn->sess->init_task_tag = cmd->init_task_tag = hdr->itt;
  	if (hdr->flags & ISCSI_FLAG_CMD_READ)
  		cmd->targ_xfer_tag = session_get_next_ttt(conn->sess);
  	else
  		cmd->targ_xfer_tag = 0xFFFFFFFF;
  	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
  	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
  	cmd->first_burst_len	= payload_length;
  
  	if (!conn->sess->sess_ops->RDMAExtensions &&
  	     cmd->data_direction == DMA_FROM_DEVICE) {
  		struct iscsi_datain_req *dr;
  
  		dr = iscsit_allocate_datain_req();
  		if (!dr)
  			return iscsit_add_reject_cmd(cmd,
  					ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
  
  		iscsit_attach_datain_req(cmd, dr);
  	}
  
  	/*
  	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
  	 */
  	transport_init_se_cmd(&cmd->se_cmd, &iscsi_ops,
  			conn->sess->se_sess, be32_to_cpu(hdr->data_length),
  			cmd->data_direction, sam_task_attr,
  			cmd->sense_buffer + 2);
  
  	pr_debug("Got SCSI Command, ITT: 0x%08x, CmdSN: 0x%08x,"
  		" ExpXferLen: %u, Length: %u, CID: %hu\n", hdr->itt,
  		hdr->cmdsn, be32_to_cpu(hdr->data_length), payload_length,
  		conn->cid);
  
  	target_get_sess_cmd(&cmd->se_cmd, true);
  
  	cmd->sense_reason = transport_lookup_cmd_lun(&cmd->se_cmd,
  						     scsilun_to_int(&hdr->lun));
  	if (cmd->sense_reason)
  		goto attach_cmd;
  
  	/* only used for printks or comparing with ->ref_task_tag */
  	cmd->se_cmd.tag = (__force u32)cmd->init_task_tag;
  	cmd->sense_reason = target_setup_cmd_from_cdb(&cmd->se_cmd, hdr->cdb);
  	if (cmd->sense_reason) {
  		if (cmd->sense_reason == TCM_OUT_OF_RESOURCES) {
  			return iscsit_add_reject_cmd(cmd,
  					ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
  		}
  
  		goto attach_cmd;
  	}
  
  	if (iscsit_build_pdu_and_seq_lists(cmd, payload_length) < 0) {
  		return iscsit_add_reject_cmd(cmd,
  				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
  	}
  
  attach_cmd:
  	spin_lock_bh(&conn->cmd_lock);
  	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
  	spin_unlock_bh(&conn->cmd_lock);
  	/*
  	 * Check if we need to delay processing because of ALUA
  	 * Active/NonOptimized primary access state..
  	 */
  	core_alua_check_nonop_delay(&cmd->se_cmd);
  
  	return 0;
  }
  EXPORT_SYMBOL(iscsit_setup_scsi_cmd);
  
  void iscsit_set_unsolicited_dataout(struct iscsi_cmd *cmd)
  {
  	iscsit_set_dataout_sequence_values(cmd);
  
  	spin_lock_bh(&cmd->dataout_timeout_lock);
  	iscsit_start_dataout_timer(cmd, cmd->conn);
  	spin_unlock_bh(&cmd->dataout_timeout_lock);
  }
  EXPORT_SYMBOL(iscsit_set_unsolicited_dataout);
  
  int iscsit_process_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
  			    struct iscsi_scsi_req *hdr)
  {
  	int cmdsn_ret = 0;
  	/*
  	 * Check the CmdSN against ExpCmdSN/MaxCmdSN here if
  	 * the Immediate Bit is not set, and no Immediate
  	 * Data is attached.
  	 *
  	 * A PDU/CmdSN carrying Immediate Data can only
  	 * be processed after the DataCRC has passed.
  	 * If the DataCRC fails, the CmdSN MUST NOT
  	 * be acknowledged. (See below)
  	 */
  	if (!cmd->immediate_data) {
  		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
  					(unsigned char *)hdr, hdr->cmdsn);
  		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
  			return -1;
  		else if (cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
  			target_put_sess_cmd(&cmd->se_cmd);
  			return 0;
  		}
  	}
  
  	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
  
  	/*
  	 * If no Immediate Data is attached, it's OK to return now.
  	 */
  	if (!cmd->immediate_data) {
  		if (!cmd->sense_reason && cmd->unsolicited_data)
  			iscsit_set_unsolicited_dataout(cmd);
  		if (!cmd->sense_reason)
  			return 0;
  
  		target_put_sess_cmd(&cmd->se_cmd);
  		return 0;
  	}
  
  	/*
  	 * Early CHECK_CONDITIONs with ImmediateData never make it to command
  	 * execution.  These exceptions are processed in CmdSN order using
  	 * iscsit_check_received_cmdsn() in iscsit_get_immediate_data() below.
  	 */
  	if (cmd->sense_reason)
  		return 1;
  	/*
  	 * Call directly into transport_generic_new_cmd() to perform
  	 * the backend memory allocation.
  	 */
  	cmd->sense_reason = transport_generic_new_cmd(&cmd->se_cmd);
  	if (cmd->sense_reason)
  		return 1;
  
  	return 0;
  }
  EXPORT_SYMBOL(iscsit_process_scsi_cmd);
  
  static int
  iscsit_get_immediate_data(struct iscsi_cmd *cmd, struct iscsi_scsi_req *hdr,
  			  bool dump_payload)
  {
  	int cmdsn_ret = 0, immed_ret = IMMEDIATE_DATA_NORMAL_OPERATION;
  	int rc;
  
  	/*
  	 * Special case for Unsupported SAM WRITE Opcodes and ImmediateData=Yes.
  	 */
  	if (dump_payload) {
  		u32 length = min(cmd->se_cmd.data_length - cmd->write_data_done,
  				 cmd->first_burst_len);
  
  		pr_debug("Dumping min(%d - %d, %d) = %d bytes of immediate data\n",
  			 cmd->se_cmd.data_length, cmd->write_data_done,
  			 cmd->first_burst_len, length);
  		rc = iscsit_dump_data_payload(cmd->conn, length, 1);
  		pr_debug("Finished dumping immediate data\n");
  		if (rc < 0)
  			immed_ret = IMMEDIATE_DATA_CANNOT_RECOVER;
  	} else {
  		immed_ret = iscsit_handle_immediate_data(cmd, hdr,
  							 cmd->first_burst_len);
  	}
  
  	if (immed_ret == IMMEDIATE_DATA_NORMAL_OPERATION) {
  		/*
  		 * A PDU/CmdSN carrying Immediate Data passed
  		 * DataCRC, check against ExpCmdSN/MaxCmdSN if
  		 * Immediate Bit is not set.
  		 */
  		cmdsn_ret = iscsit_sequence_cmd(cmd->conn, cmd,
  					(unsigned char *)hdr, hdr->cmdsn);
  		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
  			return -1;
  
  		if (cmd->sense_reason || cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
  			target_put_sess_cmd(&cmd->se_cmd);
  
  			return 0;
  		} else if (cmd->unsolicited_data)
  			iscsit_set_unsolicited_dataout(cmd);
  
  	} else if (immed_ret == IMMEDIATE_DATA_ERL1_CRC_FAILURE) {
  		/*
  		 * Immediate Data failed DataCRC and ERL>=1,
  		 * silently drop this PDU and let the initiator
  		 * plug the CmdSN gap.
  		 *
  		 * FIXME: Send Unsolicited NOPIN with reserved
  		 * TTT here to help the initiator figure out
  		 * the missing CmdSN, although they should be
  		 * intelligent enough to determine the missing
  		 * CmdSN and issue a retry to plug the sequence.
  		 */
  		cmd->i_state = ISTATE_REMOVE;
  		iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, cmd->i_state);
  	} else /* immed_ret == IMMEDIATE_DATA_CANNOT_RECOVER */
  		return -1;
  
  	return 0;
  }
  
  static int
  iscsit_handle_scsi_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
  			   unsigned char *buf)
  {
  	struct iscsi_scsi_req *hdr = (struct iscsi_scsi_req *)buf;
  	int rc, immed_data;
  	bool dump_payload = false;
  
  	rc = iscsit_setup_scsi_cmd(conn, cmd, buf);
  	if (rc < 0)
  		return 0;
  	/*
  	 * Allocation iovecs needed for struct socket operations for
  	 * traditional iSCSI block I/O.
  	 */
  	if (iscsit_allocate_iovecs(cmd) < 0) {
  		return iscsit_reject_cmd(cmd,
  				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
  	}
  	immed_data = cmd->immediate_data;
  
  	rc = iscsit_process_scsi_cmd(conn, cmd, hdr);
  	if (rc < 0)
  		return rc;
  	else if (rc > 0)
  		dump_payload = true;
  
  	if (!immed_data)
  		return 0;
  
  	return iscsit_get_immediate_data(cmd, hdr, dump_payload);
  }
  
  static u32 iscsit_do_crypto_hash_sg(
  	struct ahash_request *hash,
  	struct iscsi_cmd *cmd,
  	u32 data_offset,
  	u32 data_length,
  	u32 padding,
  	u8 *pad_bytes)
  {
  	u32 data_crc;
  	struct scatterlist *sg;
  	unsigned int page_off;
  
  	crypto_ahash_init(hash);
  
  	sg = cmd->first_data_sg;
  	page_off = cmd->first_data_sg_off;
  
  	while (data_length) {
  		u32 cur_len = min_t(u32, data_length, (sg->length - page_off));
  
  		ahash_request_set_crypt(hash, sg, NULL, cur_len);
  		crypto_ahash_update(hash);
  
  		data_length -= cur_len;
  		page_off = 0;
  		/* iscsit_map_iovec has already checked for invalid sg pointers */
  		sg = sg_next(sg);
  	}
  
  	if (padding) {
  		struct scatterlist pad_sg;
  
  		sg_init_one(&pad_sg, pad_bytes, padding);
  		ahash_request_set_crypt(hash, &pad_sg, (u8 *)&data_crc,
  					padding);
  		crypto_ahash_finup(hash);
  	} else {
  		ahash_request_set_crypt(hash, NULL, (u8 *)&data_crc, 0);
  		crypto_ahash_final(hash);
  	}
  
  	return data_crc;
  }
  
  static void iscsit_do_crypto_hash_buf(struct ahash_request *hash,
  	const void *buf, u32 payload_length, u32 padding,
  	const void *pad_bytes, void *data_crc)
  {
  	struct scatterlist sg[2];
  
  	sg_init_table(sg, ARRAY_SIZE(sg));
  	sg_set_buf(sg, buf, payload_length);
  	if (padding)
  		sg_set_buf(sg + 1, pad_bytes, padding);
  
  	ahash_request_set_crypt(hash, sg, data_crc, payload_length + padding);
  
  	crypto_ahash_digest(hash);
  }
  
  int
  __iscsit_check_dataout_hdr(struct iscsi_conn *conn, void *buf,
  			   struct iscsi_cmd *cmd, u32 payload_length,
  			   bool *success)
  {
  	struct iscsi_data *hdr = buf;
  	struct se_cmd *se_cmd;
  	int rc;
  
  	/* iSCSI write */
  	atomic_long_add(payload_length, &conn->sess->rx_data_octets);
  
  	pr_debug("Got DataOut ITT: 0x%08x, TTT: 0x%08x,"
  		" DataSN: 0x%08x, Offset: %u, Length: %u, CID: %hu\n",
  		hdr->itt, hdr->ttt, hdr->datasn, ntohl(hdr->offset),
  		payload_length, conn->cid);
  
  	if (cmd->cmd_flags & ICF_GOT_LAST_DATAOUT) {
  		pr_err("Command ITT: 0x%08x received DataOUT after"
  			" last DataOUT received, dumping payload\n",
  			cmd->init_task_tag);
  		return iscsit_dump_data_payload(conn, payload_length, 1);
  	}
  
  	if (cmd->data_direction != DMA_TO_DEVICE) {
  		pr_err("Command ITT: 0x%08x received DataOUT for a"
  			" NON-WRITE command.\n", cmd->init_task_tag);
  		return iscsit_dump_data_payload(conn, payload_length, 1);
  	}
  	se_cmd = &cmd->se_cmd;
  	iscsit_mod_dataout_timer(cmd);
  
  	if ((be32_to_cpu(hdr->offset) + payload_length) > cmd->se_cmd.data_length) {
  		pr_err("DataOut Offset: %u, Length %u greater than iSCSI Command EDTL %u, protocol error.\n",
  		       be32_to_cpu(hdr->offset), payload_length,
  		       cmd->se_cmd.data_length);
  		return iscsit_reject_cmd(cmd, ISCSI_REASON_BOOKMARK_INVALID, buf);
  	}
  
  	if (cmd->unsolicited_data) {
  		int dump_unsolicited_data = 0;
  
  		if (conn->sess->sess_ops->InitialR2T) {
  			pr_err("Received unexpected unsolicited data"
  				" while InitialR2T=Yes, protocol error.\n");
  			transport_send_check_condition_and_sense(&cmd->se_cmd,
  					TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
  			return -1;
  		}
  		/*
  		 * Special case for dealing with Unsolicited DataOUT
  		 * and Unsupported SAM WRITE Opcodes and SE resource allocation
  		 * failures;
  		 */
  
  		/* Something's amiss if we're not in WRITE_PENDING state... */
  		WARN_ON(se_cmd->t_state != TRANSPORT_WRITE_PENDING);
  		if (!(se_cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE))
  			dump_unsolicited_data = 1;
  
  		if (dump_unsolicited_data) {
  			/*
  			 * Check if a delayed TASK_ABORTED status needs to
  			 * be sent now if the ISCSI_FLAG_CMD_FINAL has been
  			 * received with the unsolicited data out.
  			 */
  			if (hdr->flags & ISCSI_FLAG_CMD_FINAL)
  				iscsit_stop_dataout_timer(cmd);
  
  			return iscsit_dump_data_payload(conn, payload_length, 1);
  		}
  	} else {
  		/*
  		 * For the normal solicited data path:
  		 *
  		 * Check for a delayed TASK_ABORTED status and dump any
  		 * incoming data out payload if one exists.  Also, when the
  		 * ISCSI_FLAG_CMD_FINAL is set to denote the end of the current
  		 * data out sequence, we decrement outstanding_r2ts.  Once
  		 * outstanding_r2ts reaches zero, go ahead and send the delayed
  		 * TASK_ABORTED status.
  		 */
  		if (se_cmd->transport_state & CMD_T_ABORTED) {
  			if (hdr->flags & ISCSI_FLAG_CMD_FINAL &&
  			    --cmd->outstanding_r2ts < 1)
  				iscsit_stop_dataout_timer(cmd);
  
  			return iscsit_dump_data_payload(conn, payload_length, 1);
  		}
  	}
  	/*
  	 * Perform DataSN, DataSequenceInOrder, DataPDUInOrder, and
  	 * within-command recovery checks before receiving the payload.
  	 */
  	rc = iscsit_check_pre_dataout(cmd, buf);
  	if (rc == DATAOUT_WITHIN_COMMAND_RECOVERY)
  		return 0;
  	else if (rc == DATAOUT_CANNOT_RECOVER)
  		return -1;
  	*success = true;
  	return 0;
  }
  EXPORT_SYMBOL(__iscsit_check_dataout_hdr);
  
  int
  iscsit_check_dataout_hdr(struct iscsi_conn *conn, void *buf,
  			 struct iscsi_cmd **out_cmd)
  {
  	struct iscsi_data *hdr = buf;
  	struct iscsi_cmd *cmd;
  	u32 payload_length = ntoh24(hdr->dlength);
  	int rc;
  	bool success = false;
  
  	if (!payload_length) {
  		pr_warn_ratelimited("DataOUT payload is ZERO, ignoring.\n");
  		return 0;
  	}
  
  	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
  		pr_err_ratelimited("DataSegmentLength: %u is greater than"
  			" MaxXmitDataSegmentLength: %u\n", payload_length,
  			conn->conn_ops->MaxXmitDataSegmentLength);
  		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR, buf);
  	}
  
  	cmd = iscsit_find_cmd_from_itt_or_dump(conn, hdr->itt, payload_length);
  	if (!cmd)
  		return 0;
  
  	rc = __iscsit_check_dataout_hdr(conn, buf, cmd, payload_length, &success);
  
  	if (success)
  		*out_cmd = cmd;
  
  	return rc;
  }
  EXPORT_SYMBOL(iscsit_check_dataout_hdr);
  
  static int
  iscsit_get_dataout(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
  		   struct iscsi_data *hdr)
  {
  	struct kvec *iov;
  	u32 checksum, iov_count = 0, padding = 0, rx_got = 0, rx_size = 0;
  	u32 payload_length;
  	int iov_ret, data_crc_failed = 0;
  
  	payload_length = min_t(u32, cmd->se_cmd.data_length,
  			       ntoh24(hdr->dlength));
  	rx_size += payload_length;
  	iov = &cmd->iov_data[0];
  
  	iov_ret = iscsit_map_iovec(cmd, iov, cmd->orig_iov_data_count - 2,
  				   be32_to_cpu(hdr->offset), payload_length);
  	if (iov_ret < 0)
  		return -1;
  
  	iov_count += iov_ret;
  
  	padding = ((-payload_length) & 3);
  	if (padding != 0) {
  		iov[iov_count].iov_base	= cmd->pad_bytes;
  		iov[iov_count++].iov_len = padding;
  		rx_size += padding;
  		pr_debug("Receiving %u padding bytes.\n", padding);
  	}
  
  	if (conn->conn_ops->DataDigest) {
  		iov[iov_count].iov_base = &checksum;
  		iov[iov_count++].iov_len = ISCSI_CRC_LEN;
  		rx_size += ISCSI_CRC_LEN;
  	}
  
  	WARN_ON_ONCE(iov_count > cmd->orig_iov_data_count);
  	rx_got = rx_data(conn, &cmd->iov_data[0], iov_count, rx_size);
  
  	iscsit_unmap_iovec(cmd);
  
  	if (rx_got != rx_size)
  		return -1;
  
  	if (conn->conn_ops->DataDigest) {
  		u32 data_crc;
  
  		data_crc = iscsit_do_crypto_hash_sg(conn->conn_rx_hash, cmd,
  						    be32_to_cpu(hdr->offset),
  						    payload_length, padding,
  						    cmd->pad_bytes);
  
  		if (checksum != data_crc) {
  			pr_err("ITT: 0x%08x, Offset: %u, Length: %u,"
  				" DataSN: 0x%08x, CRC32C DataDigest 0x%08x"
  				" does not match computed 0x%08x\n",
  				hdr->itt, hdr->offset, payload_length,
  				hdr->datasn, checksum, data_crc);
  			data_crc_failed = 1;
  		} else {
  			pr_debug("Got CRC32C DataDigest 0x%08x for"
  				" %u bytes of Data Out\n", checksum,
  				payload_length);
  		}
  	}
  
  	return data_crc_failed;
  }
  
  int
  iscsit_check_dataout_payload(struct iscsi_cmd *cmd, struct iscsi_data *hdr,
  			     bool data_crc_failed)
  {
  	struct iscsi_conn *conn = cmd->conn;
  	int rc, ooo_cmdsn;
  	/*
  	 * Increment post receive data and CRC values or perform
  	 * within-command recovery.
  	 */
  	rc = iscsit_check_post_dataout(cmd, (unsigned char *)hdr, data_crc_failed);
  	if ((rc == DATAOUT_NORMAL) || (rc == DATAOUT_WITHIN_COMMAND_RECOVERY))
  		return 0;
  	else if (rc == DATAOUT_SEND_R2T) {
  		iscsit_set_dataout_sequence_values(cmd);
  		conn->conn_transport->iscsit_get_dataout(conn, cmd, false);
  	} else if (rc == DATAOUT_SEND_TO_TRANSPORT) {
  		/*
  		 * Handle extra special case for out of order
  		 * Unsolicited Data Out.
  		 */
  		spin_lock_bh(&cmd->istate_lock);
  		ooo_cmdsn = (cmd->cmd_flags & ICF_OOO_CMDSN);
  		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
  		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
  		spin_unlock_bh(&cmd->istate_lock);
  
  		iscsit_stop_dataout_timer(cmd);
  		if (ooo_cmdsn)
  			return 0;
  		target_execute_cmd(&cmd->se_cmd);
  		return 0;
  	} else /* DATAOUT_CANNOT_RECOVER */
  		return -1;
  
  	return 0;
  }
  EXPORT_SYMBOL(iscsit_check_dataout_payload);
  
  static int iscsit_handle_data_out(struct iscsi_conn *conn, unsigned char *buf)
  {
  	struct iscsi_cmd *cmd = NULL;
  	struct iscsi_data *hdr = (struct iscsi_data *)buf;
  	int rc;
  	bool data_crc_failed = false;
  
  	rc = iscsit_check_dataout_hdr(conn, buf, &cmd);
  	if (rc < 0)
  		return 0;
  	else if (!cmd)
  		return 0;
  
  	rc = iscsit_get_dataout(conn, cmd, hdr);
  	if (rc < 0)
  		return rc;
  	else if (rc > 0)
  		data_crc_failed = true;
  
  	return iscsit_check_dataout_payload(cmd, hdr, data_crc_failed);
  }
  
  int iscsit_setup_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
  			 struct iscsi_nopout *hdr)
  {
  	u32 payload_length = ntoh24(hdr->dlength);
  
  	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL)) {
  		pr_err("NopOUT Flag's, Left Most Bit not set, protocol error.\n");
  		if (!cmd)
  			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
  						 (unsigned char *)hdr);
  		
  		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
  					 (unsigned char *)hdr);
  	}
  
  	if (hdr->itt == RESERVED_ITT && !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
  		pr_err("NOPOUT ITT is reserved, but Immediate Bit is"
  			" not set, protocol error.\n");
  		if (!cmd)
  			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
  						 (unsigned char *)hdr);
  
  		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
  					 (unsigned char *)hdr);
  	}
  
  	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
  		pr_err("NOPOUT Ping Data DataSegmentLength: %u is"
  			" greater than MaxXmitDataSegmentLength: %u, protocol"
  			" error.\n", payload_length,
  			conn->conn_ops->MaxXmitDataSegmentLength);
  		if (!cmd)
  			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
  						 (unsigned char *)hdr);
  
  		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
  					 (unsigned char *)hdr);
  	}
  
  	pr_debug("Got NOPOUT Ping %s ITT: 0x%08x, TTT: 0x%08x,"
  		" CmdSN: 0x%08x, ExpStatSN: 0x%08x, Length: %u\n",
  		hdr->itt == RESERVED_ITT ? "Response" : "Request",
  		hdr->itt, hdr->ttt, hdr->cmdsn, hdr->exp_statsn,
  		payload_length);
  	/*
  	 * This is not a response to a Unsolicited NopIN, which means
  	 * it can either be a NOPOUT ping request (with a valid ITT),
  	 * or a NOPOUT not requesting a NOPIN (with a reserved ITT).
  	 * Either way, make sure we allocate an struct iscsi_cmd, as both
  	 * can contain ping data.
  	 */
  	if (hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
  		cmd->iscsi_opcode	= ISCSI_OP_NOOP_OUT;
  		cmd->i_state		= ISTATE_SEND_NOPIN;
  		cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ?
  						1 : 0);
  		conn->sess->init_task_tag = cmd->init_task_tag = hdr->itt;
  		cmd->targ_xfer_tag	= 0xFFFFFFFF;
  		cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
  		cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
  		cmd->data_direction	= DMA_NONE;
  	}
  
  	return 0;
  }
  EXPORT_SYMBOL(iscsit_setup_nop_out);
  
  int iscsit_process_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
  			   struct iscsi_nopout *hdr)
  {
  	struct iscsi_cmd *cmd_p = NULL;
  	int cmdsn_ret = 0;
  	/*
  	 * Initiator is expecting a NopIN ping reply..
  	 */
  	if (hdr->itt != RESERVED_ITT) {
  		if (!cmd)
  			return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
  						(unsigned char *)hdr);
  
  		spin_lock_bh(&conn->cmd_lock);
  		list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
  		spin_unlock_bh(&conn->cmd_lock);
  
  		iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
  
  		if (hdr->opcode & ISCSI_OP_IMMEDIATE) {
  			iscsit_add_cmd_to_response_queue(cmd, conn,
  							 cmd->i_state);
  			return 0;
  		}
  
  		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
  				(unsigned char *)hdr, hdr->cmdsn);
                  if (cmdsn_ret == CMDSN_LOWER_THAN_EXP)
  			return 0;
  		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
  			return -1;
  
  		return 0;
  	}
  	/*
  	 * This was a response to a unsolicited NOPIN ping.
  	 */
  	if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
  		cmd_p = iscsit_find_cmd_from_ttt(conn, be32_to_cpu(hdr->ttt));
  		if (!cmd_p)
  			return -EINVAL;
  
  		iscsit_stop_nopin_response_timer(conn);
  
  		cmd_p->i_state = ISTATE_REMOVE;
  		iscsit_add_cmd_to_immediate_queue(cmd_p, conn, cmd_p->i_state);
  
  		iscsit_start_nopin_timer(conn);
  		return 0;
  	}
  	/*
  	 * Otherwise, initiator is not expecting a NOPIN is response.
  	 * Just ignore for now.
  	 */
  
  	if (cmd)
  		iscsit_free_cmd(cmd, false);
  
          return 0;
  }
  EXPORT_SYMBOL(iscsit_process_nop_out);
  
  static int iscsit_handle_nop_out(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
  				 unsigned char *buf)
  {
  	unsigned char *ping_data = NULL;
  	struct iscsi_nopout *hdr = (struct iscsi_nopout *)buf;
  	struct kvec *iov = NULL;
  	u32 payload_length = ntoh24(hdr->dlength);
  	int ret;
  
  	ret = iscsit_setup_nop_out(conn, cmd, hdr);
  	if (ret < 0)
  		return 0;
  	/*
  	 * Handle NOP-OUT payload for traditional iSCSI sockets
  	 */
  	if (payload_length && hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
  		u32 checksum, data_crc, padding = 0;
  		int niov = 0, rx_got, rx_size = payload_length;
  
  		ping_data = kzalloc(payload_length + 1, GFP_KERNEL);
  		if (!ping_data) {
  			ret = -1;
  			goto out;
  		}
  
  		iov = &cmd->iov_misc[0];
  		iov[niov].iov_base	= ping_data;
  		iov[niov++].iov_len	= payload_length;
  
  		padding = ((-payload_length) & 3);
  		if (padding != 0) {
  			pr_debug("Receiving %u additional bytes"
  				" for padding.\n", padding);
  			iov[niov].iov_base	= &cmd->pad_bytes;
  			iov[niov++].iov_len	= padding;
  			rx_size += padding;
  		}
  		if (conn->conn_ops->DataDigest) {
  			iov[niov].iov_base	= &checksum;
  			iov[niov++].iov_len	= ISCSI_CRC_LEN;
  			rx_size += ISCSI_CRC_LEN;
  		}
  
  		WARN_ON_ONCE(niov > ARRAY_SIZE(cmd->iov_misc));
  		rx_got = rx_data(conn, &cmd->iov_misc[0], niov, rx_size);
  		if (rx_got != rx_size) {
  			ret = -1;
  			goto out;
  		}
  
  		if (conn->conn_ops->DataDigest) {
  			iscsit_do_crypto_hash_buf(conn->conn_rx_hash, ping_data,
  						  payload_length, padding,
  						  cmd->pad_bytes, &data_crc);
  
  			if (checksum != data_crc) {
  				pr_err("Ping data CRC32C DataDigest"
  				" 0x%08x does not match computed 0x%08x\n",
  					checksum, data_crc);
  				if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
  					pr_err("Unable to recover from"
  					" NOPOUT Ping DataCRC failure while in"
  						" ERL=0.\n");
  					ret = -1;
  					goto out;
  				} else {
  					/*
  					 * Silently drop this PDU and let the
  					 * initiator plug the CmdSN gap.
  					 */
  					pr_debug("Dropping NOPOUT"
  					" Command CmdSN: 0x%08x due to"
  					" DataCRC error.\n", hdr->cmdsn);
  					ret = 0;
  					goto out;
  				}
  			} else {
  				pr_debug("Got CRC32C DataDigest"
  				" 0x%08x for %u bytes of ping data.\n",
  					checksum, payload_length);
  			}
  		}
  
  		ping_data[payload_length] = '\0';
  		/*
  		 * Attach ping data to struct iscsi_cmd->buf_ptr.
  		 */
  		cmd->buf_ptr = ping_data;
  		cmd->buf_ptr_size = payload_length;
  
  		pr_debug("Got %u bytes of NOPOUT ping"
  			" data.\n", payload_length);
  		pr_debug("Ping Data: \"%s\"\n", ping_data);
  	}
  
  	return iscsit_process_nop_out(conn, cmd, hdr);
  out:
  	if (cmd)
  		iscsit_free_cmd(cmd, false);
  
  	kfree(ping_data);
  	return ret;
  }
  
  static enum tcm_tmreq_table iscsit_convert_tmf(u8 iscsi_tmf)
  {
  	switch (iscsi_tmf) {
  	case ISCSI_TM_FUNC_ABORT_TASK:
  		return TMR_ABORT_TASK;
  	case ISCSI_TM_FUNC_ABORT_TASK_SET:
  		return TMR_ABORT_TASK_SET;
  	case ISCSI_TM_FUNC_CLEAR_ACA:
  		return TMR_CLEAR_ACA;
  	case ISCSI_TM_FUNC_CLEAR_TASK_SET:
  		return TMR_CLEAR_TASK_SET;
  	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
  		return TMR_LUN_RESET;
  	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
  		return TMR_TARGET_WARM_RESET;
  	case ISCSI_TM_FUNC_TARGET_COLD_RESET:
  		return TMR_TARGET_COLD_RESET;
  	default:
  		return TMR_UNKNOWN;
  	}
  }
  
  int
  iscsit_handle_task_mgt_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
  			   unsigned char *buf)
  {
  	struct se_tmr_req *se_tmr;
  	struct iscsi_tmr_req *tmr_req;
  	struct iscsi_tm *hdr;
  	int out_of_order_cmdsn = 0, ret;
  	u8 function, tcm_function = TMR_UNKNOWN;
  
  	hdr			= (struct iscsi_tm *) buf;
  	hdr->flags &= ~ISCSI_FLAG_CMD_FINAL;
  	function = hdr->flags;
  
  	pr_debug("Got Task Management Request ITT: 0x%08x, CmdSN:"
  		" 0x%08x, Function: 0x%02x, RefTaskTag: 0x%08x, RefCmdSN:"
  		" 0x%08x, CID: %hu\n", hdr->itt, hdr->cmdsn, function,
  		hdr->rtt, hdr->refcmdsn, conn->cid);
  
  	if ((function != ISCSI_TM_FUNC_ABORT_TASK) &&
  	    ((function != ISCSI_TM_FUNC_TASK_REASSIGN) &&
  	     hdr->rtt != RESERVED_ITT)) {
  		pr_err("RefTaskTag should be set to 0xFFFFFFFF.\n");
  		hdr->rtt = RESERVED_ITT;
  	}
  
  	if ((function == ISCSI_TM_FUNC_TASK_REASSIGN) &&
  			!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
  		pr_err("Task Management Request TASK_REASSIGN not"
  			" issued as immediate command, bad iSCSI Initiator"
  				"implementation\n");
  		return iscsit_add_reject_cmd(cmd,
  					     ISCSI_REASON_PROTOCOL_ERROR, buf);
  	}
  	if ((function != ISCSI_TM_FUNC_ABORT_TASK) &&
  	    be32_to_cpu(hdr->refcmdsn) != ISCSI_RESERVED_TAG)
  		hdr->refcmdsn = cpu_to_be32(ISCSI_RESERVED_TAG);
  
  	cmd->data_direction = DMA_NONE;
  	cmd->tmr_req = kzalloc(sizeof(*cmd->tmr_req), GFP_KERNEL);
  	if (!cmd->tmr_req) {
  		return iscsit_add_reject_cmd(cmd,
  					     ISCSI_REASON_BOOKMARK_NO_RESOURCES,
  					     buf);
  	}
  
  	transport_init_se_cmd(&cmd->se_cmd, &iscsi_ops,
  			      conn->sess->se_sess, 0, DMA_NONE,
  			      TCM_SIMPLE_TAG, cmd->sense_buffer + 2);
  
  	target_get_sess_cmd(&cmd->se_cmd, true);
  
  	/*
  	 * TASK_REASSIGN for ERL=2 / connection stays inside of
  	 * LIO-Target $FABRIC_MOD
  	 */
  	if (function != ISCSI_TM_FUNC_TASK_REASSIGN) {
  		tcm_function = iscsit_convert_tmf(function);
  		if (tcm_function == TMR_UNKNOWN) {
  			pr_err("Unknown iSCSI TMR Function:"
  			       " 0x%02x\n", function);
  			return iscsit_add_reject_cmd(cmd,
  				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
  		}
  	}
  	ret = core_tmr_alloc_req(&cmd->se_cmd, cmd->tmr_req, tcm_function,
  				 GFP_KERNEL);
  	if (ret < 0)
  		return iscsit_add_reject_cmd(cmd,
  				ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
  
  	cmd->tmr_req->se_tmr_req = cmd->se_cmd.se_tmr_req;
  
  	cmd->iscsi_opcode	= ISCSI_OP_SCSI_TMFUNC;
  	cmd->i_state		= ISTATE_SEND_TASKMGTRSP;
  	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
  	cmd->init_task_tag	= hdr->itt;
  	cmd->targ_xfer_tag	= 0xFFFFFFFF;
  	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
  	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
  	se_tmr			= cmd->se_cmd.se_tmr_req;
  	tmr_req			= cmd->tmr_req;
  	/*
  	 * Locate the struct se_lun for all TMRs not related to ERL=2 TASK_REASSIGN
  	 */
  	if (function != ISCSI_TM_FUNC_TASK_REASSIGN) {
  		ret = transport_lookup_tmr_lun(&cmd->se_cmd,
  					       scsilun_to_int(&hdr->lun));
  		if (ret < 0) {
  			se_tmr->response = ISCSI_TMF_RSP_NO_LUN;
  			goto attach;
  		}
  	}
  
  	switch (function) {
  	case ISCSI_TM_FUNC_ABORT_TASK:
  		se_tmr->response = iscsit_tmr_abort_task(cmd, buf);
  		if (se_tmr->response)
  			goto attach;
  		break;
  	case ISCSI_TM_FUNC_ABORT_TASK_SET:
  	case ISCSI_TM_FUNC_CLEAR_ACA:
  	case ISCSI_TM_FUNC_CLEAR_TASK_SET:
  	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
  		break;
  	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
  		if (iscsit_tmr_task_warm_reset(conn, tmr_req, buf) < 0) {
  			se_tmr->response = ISCSI_TMF_RSP_AUTH_FAILED;
  			goto attach;
  		}
  		break;
  	case ISCSI_TM_FUNC_TARGET_COLD_RESET:
  		if (iscsit_tmr_task_cold_reset(conn, tmr_req, buf) < 0) {
  			se_tmr->response = ISCSI_TMF_RSP_AUTH_FAILED;
  			goto attach;
  		}
  		break;
  	case ISCSI_TM_FUNC_TASK_REASSIGN:
  		se_tmr->response = iscsit_tmr_task_reassign(cmd, buf);
  		/*
  		 * Perform sanity checks on the ExpDataSN only if the
  		 * TASK_REASSIGN was successful.
  		 */
  		if (se_tmr->response)
  			break;
  
  		if (iscsit_check_task_reassign_expdatasn(tmr_req, conn) < 0)
  			return iscsit_add_reject_cmd(cmd,
  					ISCSI_REASON_BOOKMARK_INVALID, buf);
  		break;
  	default:
  		pr_err("Unknown TMR function: 0x%02x, protocol"
  			" error.\n", function);
  		se_tmr->response = ISCSI_TMF_RSP_NOT_SUPPORTED;
  		goto attach;
  	}
  
  	if ((function != ISCSI_TM_FUNC_TASK_REASSIGN) &&
  	    (se_tmr->response == ISCSI_TMF_RSP_COMPLETE))
  		se_tmr->call_transport = 1;
  attach:
  	spin_lock_bh(&conn->cmd_lock);
  	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
  	spin_unlock_bh(&conn->cmd_lock);
  
  	if (!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
  		int cmdsn_ret = iscsit_sequence_cmd(conn, cmd, buf, hdr->cmdsn);
  		if (cmdsn_ret == CMDSN_HIGHER_THAN_EXP) {
  			out_of_order_cmdsn = 1;
  		} else if (cmdsn_ret == CMDSN_LOWER_THAN_EXP) {
  			target_put_sess_cmd(&cmd->se_cmd);
  			return 0;
  		} else if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER) {
  			return -1;
  		}
  	}
  	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
  
  	if (out_of_order_cmdsn || !(hdr->opcode & ISCSI_OP_IMMEDIATE))
  		return 0;
  	/*
  	 * Found the referenced task, send to transport for processing.
  	 */
  	if (se_tmr->call_transport)
  		return transport_generic_handle_tmr(&cmd->se_cmd);
  
  	/*
  	 * Could not find the referenced LUN, task, or Task Management
  	 * command not authorized or supported.  Change state and
  	 * let the tx_thread send the response.
  	 *
  	 * For connection recovery, this is also the default action for
  	 * TMR TASK_REASSIGN.
  	 */
  	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
  	target_put_sess_cmd(&cmd->se_cmd);
  	return 0;
  }
  EXPORT_SYMBOL(iscsit_handle_task_mgt_cmd);
  
  /* #warning FIXME: Support Text Command parameters besides SendTargets */
  int
  iscsit_setup_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
  		      struct iscsi_text *hdr)
  {
  	u32 payload_length = ntoh24(hdr->dlength);
  
  	if (payload_length > conn->conn_ops->MaxXmitDataSegmentLength) {
  		pr_err("Unable to accept text parameter length: %u"
  			"greater than MaxXmitDataSegmentLength %u.\n",
  		       payload_length, conn->conn_ops->MaxXmitDataSegmentLength);
  		return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
  					 (unsigned char *)hdr);
  	}
  
  	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL) ||
  	     (hdr->flags & ISCSI_FLAG_TEXT_CONTINUE)) {
  		pr_err("Multi sequence text commands currently not supported\n");
  		return iscsit_reject_cmd(cmd, ISCSI_REASON_CMD_NOT_SUPPORTED,
  					(unsigned char *)hdr);
  	}
  
  	pr_debug("Got Text Request: ITT: 0x%08x, CmdSN: 0x%08x,"
  		" ExpStatSN: 0x%08x, Length: %u\n", hdr->itt, hdr->cmdsn,
  		hdr->exp_statsn, payload_length);
  
  	cmd->iscsi_opcode	= ISCSI_OP_TEXT;
  	cmd->i_state		= ISTATE_SEND_TEXTRSP;
  	cmd->immediate_cmd	= ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
  	conn->sess->init_task_tag = cmd->init_task_tag  = hdr->itt;
  	cmd->targ_xfer_tag	= 0xFFFFFFFF;
  	cmd->cmd_sn		= be32_to_cpu(hdr->cmdsn);
  	cmd->exp_stat_sn	= be32_to_cpu(hdr->exp_statsn);
  	cmd->data_direction	= DMA_NONE;
  	kfree(cmd->text_in_ptr);
  	cmd->text_in_ptr	= NULL;
  
  	return 0;
  }
  EXPORT_SYMBOL(iscsit_setup_text_cmd);
  
  int
  iscsit_process_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
  			struct iscsi_text *hdr)
  {
  	unsigned char *text_in = cmd->text_in_ptr, *text_ptr;
  	int cmdsn_ret;
  
  	if (!text_in) {
  		cmd->targ_xfer_tag = be32_to_cpu(hdr->ttt);
  		if (cmd->targ_xfer_tag == 0xFFFFFFFF) {
  			pr_err("Unable to locate text_in buffer for sendtargets"
  			       " discovery\n");
  			goto reject;
  		}
  		goto empty_sendtargets;
  	}
  	if (strncmp("SendTargets", text_in, 11) != 0) {
  		pr_err("Received Text Data that is not"
  			" SendTargets, cannot continue.\n");
  		goto reject;
  	}
  	text_ptr = strchr(text_in, '=');
  	if (!text_ptr) {
  		pr_err("No \"=\" separator found in Text Data,"
  			"  cannot continue.\n");
  		goto reject;
  	}
  	if (!strncmp("=All", text_ptr, 4)) {
  		cmd->cmd_flags |= ICF_SENDTARGETS_ALL;
  	} else if (!strncmp("=iqn.", text_ptr, 5) ||
  		   !strncmp("=eui.", text_ptr, 5)) {
  		cmd->cmd_flags |= ICF_SENDTARGETS_SINGLE;
  	} else {
  		pr_err("Unable to locate valid SendTargets=%s value\n", text_ptr);
  		goto reject;
  	}
  
  	spin_lock_bh(&conn->cmd_lock);
  	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
  	spin_unlock_bh(&conn->cmd_lock);
  
  empty_sendtargets:
  	iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
  
  	if (!(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
  		cmdsn_ret = iscsit_sequence_cmd(conn, cmd,
  				(unsigned char *)hdr, hdr->cmdsn);
  		if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
  			return -1;
  
  		return 0;
  	}
  
  	return iscsit_execute_cmd(cmd, 0);
  
  reject:
  	return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR,
  				 (unsigned char *)hdr);
  }
  EXPORT_SYMBOL(iscsit_process_text_cmd);
  
  static int
  iscsit_handle_text_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
  		       unsigned char *buf)
  {
  	struct iscsi_text *hdr = (struct iscsi_text *)buf;
  	char *text_in = NULL;
  	u32 payload_length = ntoh24(hdr->dlength);
  	int rx_size, rc;
  
  	rc = iscsit_setup_text_cmd(conn, cmd, hdr);
  	if (rc < 0)
  		return 0;
  
  	rx_size = payload_length;
  	if (payload_length) {
  		u32 checksum = 0, data_crc = 0;
  		u32 padding = 0;
  		int niov = 0, rx_got;
  		struct kvec iov[2];
  
  		rx_size = ALIGN(payload_length, 4);
  		text_in = kzalloc(rx_size, GFP_KERNEL);
  		if (!text_in)
  			goto reject;
  
  		cmd->text_in_ptr = text_in;
  
  		memset(iov, 0, sizeof(iov));
  		iov[niov].iov_base	= text_in;
  		iov[niov++].iov_len	= rx_size;
  
  		padding = rx_size - payload_length;
  		if (padding)
  			pr_debug("Receiving %u additional bytes"
  					" for padding.\n", padding);
  		if (conn->conn_ops->DataDigest) {
  			iov[niov].iov_base	= &checksum;
  			iov[niov++].iov_len	= ISCSI_CRC_LEN;
  			rx_size += ISCSI_CRC_LEN;
  		}
  
  		WARN_ON_ONCE(niov > ARRAY_SIZE(iov));
  		rx_got = rx_data(conn, &iov[0], niov, rx_size);
  		if (rx_got != rx_size)
  			goto reject;
  
  		if (conn->conn_ops->DataDigest) {
  			iscsit_do_crypto_hash_buf(conn->conn_rx_hash,
  						  text_in, rx_size, 0, NULL,
  						  &data_crc);
  
  			if (checksum != data_crc) {
  				pr_err("Text data CRC32C DataDigest"
  					" 0x%08x does not match computed"
  					" 0x%08x\n", checksum, data_crc);
  				if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
  					pr_err("Unable to recover from"
  					" Text Data digest failure while in"
  						" ERL=0.\n");
  					goto reject;
  				} else {
  					/*
  					 * Silently drop this PDU and let the
  					 * initiator plug the CmdSN gap.
  					 */
  					pr_debug("Dropping Text"
  					" Command CmdSN: 0x%08x due to"
  					" DataCRC error.\n", hdr->cmdsn);
  					kfree(text_in);
  					return 0;
  				}
  			} else {
  				pr_debug("Got CRC32C DataDigest"
  					" 0x%08x for %u bytes of text data.\n",
  						checksum, payload_length);
  			}
  		}
  		text_in[payload_length - 1] = '\0';
  		pr_debug("Successfully read %d bytes of text"
  				" data.\n", payload_length);
  	}
  
  	return iscsit_process_text_cmd(conn, cmd, hdr);
  
  reject:
  	kfree(cmd->text_in_ptr);
  	cmd->text_in_ptr = NULL;
  	return iscsit_reject_cmd(cmd, ISCSI_REASON_PROTOCOL_ERROR, buf);
  }
  
  int iscsit_logout_closesession(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
  {
  	struct iscsi_conn *conn_p;
  	struct iscsi_session *sess = conn->sess;
  
  	pr_debug("Received logout request CLOSESESSION on CID: %hu"
  		" for SID: %u.\n", conn->cid, conn->sess->sid);
  
  	atomic_set(&sess->session_logout, 1);
  	atomic_set(&conn->conn_logout_remove, 1);
  	conn->conn_logout_reason = ISCSI_LOGOUT_REASON_CLOSE_SESSION;
  
  	iscsit_inc_conn_usage_count(conn);
  	iscsit_inc_session_usage_count(sess);
  
  	spin_lock_bh(&sess->conn_lock);
  	list_for_each_entry(conn_p, &sess->sess_conn_list, conn_list) {
  		if (conn_p->conn_state != TARG_CONN_STATE_LOGGED_IN)
  			continue;
  
  		pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
  		conn_p->conn_state = TARG_CONN_STATE_IN_LOGOUT;
  	}
  	spin_unlock_bh(&sess->conn_lock);
  
  	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
  
  	return 0;
  }
  
  int iscsit_logout_closeconnection(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
  {
  	struct iscsi_conn *l_conn;
  	struct iscsi_session *sess = conn->sess;
  
  	pr_debug("Received logout request CLOSECONNECTION for CID:"
  		" %hu on CID: %hu.\n", cmd->logout_cid, conn->cid);
  
  	/*
  	 * A Logout Request with a CLOSECONNECTION reason code for a CID
  	 * can arrive on a connection with a differing CID.
  	 */
  	if (conn->cid == cmd->logout_cid) {
  		spin_lock_bh(&conn->state_lock);
  		pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
  		conn->conn_state = TARG_CONN_STATE_IN_LOGOUT;
  
  		atomic_set(&conn->conn_logout_remove, 1);
  		conn->conn_logout_reason = ISCSI_LOGOUT_REASON_CLOSE_CONNECTION;
  		iscsit_inc_conn_usage_count(conn);
  
  		spin_unlock_bh(&conn->state_lock);
  	} else {
  		/*
  		 * Handle all different cid CLOSECONNECTION requests in
  		 * iscsit_logout_post_handler_diffcid() as to give enough
  		 * time for any non immediate command's CmdSN to be
  		 * acknowledged on the connection in question.
  		 *
  		 * Here we simply make sure the CID is still around.
  		 */
  		l_conn = iscsit_get_conn_from_cid(sess,
  				cmd->logout_cid);
  		if (!l_conn) {
  			cmd->logout_response = ISCSI_LOGOUT_CID_NOT_FOUND;
  			iscsit_add_cmd_to_response_queue(cmd, conn,
  					cmd->i_state);
  			return 0;
  		}
  
  		iscsit_dec_conn_usage_count(l_conn);
  	}
  
  	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
  
  	return 0;
  }
  
  int iscsit_logout_removeconnforrecovery(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
  {
  	struct iscsi_session *sess = conn->sess;
  
  	pr_debug("Received explicit REMOVECONNFORRECOVERY logout for"
  		" CID: %hu on CID: %hu.\n", cmd->logout_cid, conn->cid);
  
  	if (sess->sess_ops->ErrorRecoveryLevel != 2) {
  		pr_err("Received Logout Request REMOVECONNFORRECOVERY"
  			" while ERL!=2.\n");
  		cmd->logout_response = ISCSI_LOGOUT_RECOVERY_UNSUPPORTED;
  		iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
  		return 0;
  	}
  
  	if (conn->cid == cmd->logout_cid) {
  		pr_err("Received Logout Request REMOVECONNFORRECOVERY"
  			" with CID: %hu on CID: %hu, implementation error.\n",
  				cmd->logout_cid, conn->cid);
  		cmd->logout_response = ISCSI_LOGOUT_CLEANUP_FAILED;
  		iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
  		return 0;
  	}
  
  	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
  
  	return 0;
  }
  
  int
  iscsit_handle_logout_cmd(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
  			unsigned char *buf)
  {
  	int cmdsn_ret, logout_remove = 0;
  	u8 reason_code = 0;
  	struct iscsi_logout *hdr;
  	struct iscsi_tiqn *tiqn = iscsit_snmp_get_tiqn(conn);
  
  	hdr			= (struct iscsi_logout *) buf;
  	reason_code		= (hdr->flags & 0x7f);
  
  	if (tiqn) {
  		spin_lock(&tiqn->logout_stats.lock);
  		if (reason_code == ISCSI_LOGOUT_REASON_CLOSE_SESSION)
  			tiqn->logout_stats.normal_logouts++;
  		else
  			tiqn->logout_stats.abnormal_logouts++;
  		spin_unlock(&tiqn->logout_stats.lock);
  	}
  
  	pr_debug("Got Logout Request ITT: 0x%08x CmdSN: 0x%08x"
  		" ExpStatSN: 0x%08x Reason: 0x%02x CID: %hu on CID: %hu\n",
  		hdr->itt, hdr->cmdsn, hdr->exp_statsn, reason_code,
  		hdr->cid, conn->cid);
  
  	if (conn->conn_state != TARG_CONN_STATE_LOGGED_IN) {
  		pr_err("Received logout request on connection that"
  			" is not in logged in state, ignoring request.\n");
  		iscsit_free_cmd(cmd, false);
  		return 0;
  	}
  
  	cmd->iscsi_opcode       = ISCSI_OP_LOGOUT;
  	cmd->i_state            = ISTATE_SEND_LOGOUTRSP;
  	cmd->immediate_cmd      = ((hdr->opcode & ISCSI_OP_IMMEDIATE) ? 1 : 0);
  	conn->sess->init_task_tag = cmd->init_task_tag  = hdr->itt;
  	cmd->targ_xfer_tag      = 0xFFFFFFFF;
  	cmd->cmd_sn             = be32_to_cpu(hdr->cmdsn);
  	cmd->exp_stat_sn        = be32_to_cpu(hdr->exp_statsn);
  	cmd->logout_cid         = be16_to_cpu(hdr->cid);
  	cmd->logout_reason      = reason_code;
  	cmd->data_direction     = DMA_NONE;
  
  	/*
  	 * We need to sleep in these cases (by returning 1) until the Logout
  	 * Response gets sent in the tx thread.
  	 */
  	if ((reason_code == ISCSI_LOGOUT_REASON_CLOSE_SESSION) ||
  	   ((reason_code == ISCSI_LOGOUT_REASON_CLOSE_CONNECTION) &&
  	    be16_to_cpu(hdr->cid) == conn->cid))
  		logout_remove = 1;
  
  	spin_lock_bh(&conn->cmd_lock);
  	list_add_tail(&cmd->i_conn_node, &conn->conn_cmd_list);
  	spin_unlock_bh(&conn->cmd_lock);
  
  	if (reason_code != ISCSI_LOGOUT_REASON_RECOVERY)
  		iscsit_ack_from_expstatsn(conn, be32_to_cpu(hdr->exp_statsn));
  
  	/*
  	 * Immediate commands are executed, well, immediately.
  	 * Non-Immediate Logout Commands are executed in CmdSN order.
  	 */
  	if (cmd->immediate_cmd) {
  		int ret = iscsit_execute_cmd(cmd, 0);
  
  		if (ret < 0)
  			return ret;
  	} else {
  		cmdsn_ret = iscsit_sequence_cmd(conn, cmd, buf, hdr->cmdsn);
  		if (cmdsn_ret == CMDSN_LOWER_THAN_EXP)
  			logout_remove = 0;
  		else if (cmdsn_ret == CMDSN_ERROR_CANNOT_RECOVER)
  			return -1;
  	}
  
  	return logout_remove;
  }
  EXPORT_SYMBOL(iscsit_handle_logout_cmd);
  
  int iscsit_handle_snack(
  	struct iscsi_conn *conn,
  	unsigned char *buf)
  {
  	struct iscsi_snack *hdr;
  
  	hdr			= (struct iscsi_snack *) buf;
  	hdr->flags		&= ~ISCSI_FLAG_CMD_FINAL;
  
  	pr_debug("Got ISCSI_INIT_SNACK, ITT: 0x%08x, ExpStatSN:"
  		" 0x%08x, Type: 0x%02x, BegRun: 0x%08x, RunLength: 0x%08x,"
  		" CID: %hu\n", hdr->itt, hdr->exp_statsn, hdr->flags,
  			hdr->begrun, hdr->runlength, conn->cid);
  
  	if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
  		pr_err("Initiator sent SNACK request while in"
  			" ErrorRecoveryLevel=0.\n");
  		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
  					 buf);
  	}
  	/*
  	 * SNACK_DATA and SNACK_R2T are both 0,  so check which function to
  	 * call from inside iscsi_send_recovery_datain_or_r2t().
  	 */
  	switch (hdr->flags & ISCSI_FLAG_SNACK_TYPE_MASK) {
  	case 0:
  		return iscsit_handle_recovery_datain_or_r2t(conn, buf,
  			hdr->itt,
  			be32_to_cpu(hdr->ttt),
  			be32_to_cpu(hdr->begrun),
  			be32_to_cpu(hdr->runlength));
  	case ISCSI_FLAG_SNACK_TYPE_STATUS:
  		return iscsit_handle_status_snack(conn, hdr->itt,
  			be32_to_cpu(hdr->ttt),
  			be32_to_cpu(hdr->begrun), be32_to_cpu(hdr->runlength));
  	case ISCSI_FLAG_SNACK_TYPE_DATA_ACK:
  		return iscsit_handle_data_ack(conn, be32_to_cpu(hdr->ttt),
  			be32_to_cpu(hdr->begrun),
  			be32_to_cpu(hdr->runlength));
  	case ISCSI_FLAG_SNACK_TYPE_RDATA:
  		/* FIXME: Support R-Data SNACK */
  		pr_err("R-Data SNACK Not Supported.\n");
  		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
  					 buf);
  	default:
  		pr_err("Unknown SNACK type 0x%02x, protocol"
  			" error.\n", hdr->flags & 0x0f);
  		return iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
  					 buf);
  	}
  
  	return 0;
  }
  EXPORT_SYMBOL(iscsit_handle_snack);
  
  static void iscsit_rx_thread_wait_for_tcp(struct iscsi_conn *conn)
  {
  	if ((conn->sock->sk->sk_shutdown & SEND_SHUTDOWN) ||
  	    (conn->sock->sk->sk_shutdown & RCV_SHUTDOWN)) {
  		wait_for_completion_interruptible_timeout(
  					&conn->rx_half_close_comp,
  					ISCSI_RX_THREAD_TCP_TIMEOUT * HZ);
  	}
  }
  
  static int iscsit_handle_immediate_data(
  	struct iscsi_cmd *cmd,
  	struct iscsi_scsi_req *hdr,
  	u32 length)
  {
  	int iov_ret, rx_got = 0, rx_size = 0;
  	u32 checksum, iov_count = 0, padding = 0;
  	struct iscsi_conn *conn = cmd->conn;
  	struct kvec *iov;
  	void *overflow_buf = NULL;
  
  	BUG_ON(cmd->write_data_done > cmd->se_cmd.data_length);
  	rx_size = min(cmd->se_cmd.data_length - cmd->write_data_done, length);
  	iov_ret = iscsit_map_iovec(cmd, cmd->iov_data,
  				   cmd->orig_iov_data_count - 2,
  				   cmd->write_data_done, rx_size);
  	if (iov_ret < 0)
  		return IMMEDIATE_DATA_CANNOT_RECOVER;
  
  	iov_count = iov_ret;
  	iov = &cmd->iov_data[0];
  	if (rx_size < length) {
  		/*
  		 * Special case: length of immediate data exceeds the data
  		 * buffer size derived from the CDB.
  		 */
  		overflow_buf = kmalloc(length - rx_size, GFP_KERNEL);
  		if (!overflow_buf) {
  			iscsit_unmap_iovec(cmd);
  			return IMMEDIATE_DATA_CANNOT_RECOVER;
  		}
  		cmd->overflow_buf = overflow_buf;
  		iov[iov_count].iov_base = overflow_buf;
  		iov[iov_count].iov_len = length - rx_size;
  		iov_count++;
  		rx_size = length;
  	}
  
  	padding = ((-length) & 3);
  	if (padding != 0) {
  		iov[iov_count].iov_base	= cmd->pad_bytes;
  		iov[iov_count++].iov_len = padding;
  		rx_size += padding;
  	}
  
  	if (conn->conn_ops->DataDigest) {
  		iov[iov_count].iov_base		= &checksum;
  		iov[iov_count++].iov_len	= ISCSI_CRC_LEN;
  		rx_size += ISCSI_CRC_LEN;
  	}
  
  	WARN_ON_ONCE(iov_count > cmd->orig_iov_data_count);
  	rx_got = rx_data(conn, &cmd->iov_data[0], iov_count, rx_size);
  
  	iscsit_unmap_iovec(cmd);
  
  	if (rx_got != rx_size) {
  		iscsit_rx_thread_wait_for_tcp(conn);
  		return IMMEDIATE_DATA_CANNOT_RECOVER;
  	}
  
  	if (conn->conn_ops->DataDigest) {
  		u32 data_crc;
  
  		data_crc = iscsit_do_crypto_hash_sg(conn->conn_rx_hash, cmd,
  						    cmd->write_data_done, length, padding,
  						    cmd->pad_bytes);
  
  		if (checksum != data_crc) {
  			pr_err("ImmediateData CRC32C DataDigest 0x%08x"
  				" does not match computed 0x%08x\n", checksum,
  				data_crc);
  
  			if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
  				pr_err("Unable to recover from"
  					" Immediate Data digest failure while"
  					" in ERL=0.\n");
  				iscsit_reject_cmd(cmd,
  						ISCSI_REASON_DATA_DIGEST_ERROR,
  						(unsigned char *)hdr);
  				return IMMEDIATE_DATA_CANNOT_RECOVER;
  			} else {
  				iscsit_reject_cmd(cmd,
  						ISCSI_REASON_DATA_DIGEST_ERROR,
  						(unsigned char *)hdr);
  				return IMMEDIATE_DATA_ERL1_CRC_FAILURE;
  			}
  		} else {
  			pr_debug("Got CRC32C DataDigest 0x%08x for"
  				" %u bytes of Immediate Data\n", checksum,
  				length);
  		}
  	}
  
  	cmd->write_data_done += length;
  
  	if (cmd->write_data_done == cmd->se_cmd.data_length) {
  		spin_lock_bh(&cmd->istate_lock);
  		cmd->cmd_flags |= ICF_GOT_LAST_DATAOUT;
  		cmd->i_state = ISTATE_RECEIVED_LAST_DATAOUT;
  		spin_unlock_bh(&cmd->istate_lock);
  	}
  
  	return IMMEDIATE_DATA_NORMAL_OPERATION;
  }
  
  /* #warning iscsi_build_conn_drop_async_message() only sends out on connections
  	with active network interface */
  static void iscsit_build_conn_drop_async_message(struct iscsi_conn *conn)
  {
  	struct iscsi_cmd *cmd;
  	struct iscsi_conn *conn_p;
  	bool found = false;
  
  	lockdep_assert_held(&conn->sess->conn_lock);
  
  	/*
  	 * Only send a Asynchronous Message on connections whos network
  	 * interface is still functional.
  	 */
  	list_for_each_entry(conn_p, &conn->sess->sess_conn_list, conn_list) {
  		if (conn_p->conn_state == TARG_CONN_STATE_LOGGED_IN) {
  			iscsit_inc_conn_usage_count(conn_p);
  			found = true;
  			break;
  		}
  	}
  
  	if (!found)
  		return;
  
  	cmd = iscsit_allocate_cmd(conn_p, TASK_RUNNING);
  	if (!cmd) {
  		iscsit_dec_conn_usage_count(conn_p);
  		return;
  	}
  
  	cmd->logout_cid = conn->cid;
  	cmd->iscsi_opcode = ISCSI_OP_ASYNC_EVENT;
  	cmd->i_state = ISTATE_SEND_ASYNCMSG;
  
  	spin_lock_bh(&conn_p->cmd_lock);
  	list_add_tail(&cmd->i_conn_node, &conn_p->conn_cmd_list);
  	spin_unlock_bh(&conn_p->cmd_lock);
  
  	iscsit_add_cmd_to_response_queue(cmd, conn_p, cmd->i_state);
  	iscsit_dec_conn_usage_count(conn_p);
  }
  
  static int iscsit_send_conn_drop_async_message(
  	struct iscsi_cmd *cmd,
  	struct iscsi_conn *conn)
  {
  	struct iscsi_async *hdr;
  
  	cmd->iscsi_opcode = ISCSI_OP_ASYNC_EVENT;
  
  	hdr			= (struct iscsi_async *) cmd->pdu;
  	hdr->opcode		= ISCSI_OP_ASYNC_EVENT;
  	hdr->flags		= ISCSI_FLAG_CMD_FINAL;
  	cmd->init_task_tag	= RESERVED_ITT;
  	cmd->targ_xfer_tag	= 0xFFFFFFFF;
  	put_unaligned_be64(0xFFFFFFFFFFFFFFFFULL, &hdr->rsvd4[0]);
  	cmd->stat_sn		= conn->stat_sn++;
  	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
  	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
  	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
  	hdr->async_event	= ISCSI_ASYNC_MSG_DROPPING_CONNECTION;
  	hdr->param1		= cpu_to_be16(cmd->logout_cid);
  	hdr->param2		= cpu_to_be16(conn->sess->sess_ops->DefaultTime2Wait);
  	hdr->param3		= cpu_to_be16(conn->sess->sess_ops->DefaultTime2Retain);
  
  	pr_debug("Sending Connection Dropped Async Message StatSN:"
  		" 0x%08x, for CID: %hu on CID: %hu\n", cmd->stat_sn,
  			cmd->logout_cid, conn->cid);
  
  	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
  }
  
  static void iscsit_tx_thread_wait_for_tcp(struct iscsi_conn *conn)
  {
  	if ((conn->sock->sk->sk_shutdown & SEND_SHUTDOWN) ||
  	    (conn->sock->sk->sk_shutdown & RCV_SHUTDOWN)) {
  		wait_for_completion_interruptible_timeout(
  					&conn->tx_half_close_comp,
  					ISCSI_TX_THREAD_TCP_TIMEOUT * HZ);
  	}
  }
  
  void
  iscsit_build_datain_pdu(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
  			struct iscsi_datain *datain, struct iscsi_data_rsp *hdr,
  			bool set_statsn)
  {
  	hdr->opcode		= ISCSI_OP_SCSI_DATA_IN;
  	hdr->flags		= datain->flags;
  	if (hdr->flags & ISCSI_FLAG_DATA_STATUS) {
  		if (cmd->se_cmd.se_cmd_flags & SCF_OVERFLOW_BIT) {
  			hdr->flags |= ISCSI_FLAG_DATA_OVERFLOW;
  			hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
  		} else if (cmd->se_cmd.se_cmd_flags & SCF_UNDERFLOW_BIT) {
  			hdr->flags |= ISCSI_FLAG_DATA_UNDERFLOW;
  			hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
  		}
  	}
  	hton24(hdr->dlength, datain->length);
  	if (hdr->flags & ISCSI_FLAG_DATA_ACK)
  		int_to_scsilun(cmd->se_cmd.orig_fe_lun,
  				(struct scsi_lun *)&hdr->lun);
  	else
  		put_unaligned_le64(0xFFFFFFFFFFFFFFFFULL, &hdr->lun);
  
  	hdr->itt		= cmd->init_task_tag;
  
  	if (hdr->flags & ISCSI_FLAG_DATA_ACK)
  		hdr->ttt		= cpu_to_be32(cmd->targ_xfer_tag);
  	else
  		hdr->ttt		= cpu_to_be32(0xFFFFFFFF);
  	if (set_statsn)
  		hdr->statsn		= cpu_to_be32(cmd->stat_sn);
  	else
  		hdr->statsn		= cpu_to_be32(0xFFFFFFFF);
  
  	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
  	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
  	hdr->datasn		= cpu_to_be32(datain->data_sn);
  	hdr->offset		= cpu_to_be32(datain->offset);
  
  	pr_debug("Built DataIN ITT: 0x%08x, StatSN: 0x%08x,"
  		" DataSN: 0x%08x, Offset: %u, Length: %u, CID: %hu\n",
  		cmd->init_task_tag, ntohl(hdr->statsn), ntohl(hdr->datasn),
  		ntohl(hdr->offset), datain->length, conn->cid);
  }
  EXPORT_SYMBOL(iscsit_build_datain_pdu);
  
  static int iscsit_send_datain(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
  {
  	struct iscsi_data_rsp *hdr = (struct iscsi_data_rsp *)&cmd->pdu[0];
  	struct iscsi_datain datain;
  	struct iscsi_datain_req *dr;
  	int eodr = 0, ret;
  	bool set_statsn = false;
  
  	memset(&datain, 0, sizeof(struct iscsi_datain));
  	dr = iscsit_get_datain_values(cmd, &datain);
  	if (!dr) {
  		pr_err("iscsit_get_datain_values failed for ITT: 0x%08x\n",
  				cmd->init_task_tag);
  		return -1;
  	}
  	/*
  	 * Be paranoid and double check the logic for now.
  	 */
  	if ((datain.offset + datain.length) > cmd->se_cmd.data_length) {
  		pr_err("Command ITT: 0x%08x, datain.offset: %u and"
  			" datain.length: %u exceeds cmd->data_length: %u\n",
  			cmd->init_task_tag, datain.offset, datain.length,
  			cmd->se_cmd.data_length);
  		return -1;
  	}
  
  	atomic_long_add(datain.length, &conn->sess->tx_data_octets);
  	/*
  	 * Special case for successfully execution w/ both DATAIN
  	 * and Sense Data.
  	 */
  	if ((datain.flags & ISCSI_FLAG_DATA_STATUS) &&
  	    (cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE))
  		datain.flags &= ~ISCSI_FLAG_DATA_STATUS;
  	else {
  		if ((dr->dr_complete == DATAIN_COMPLETE_NORMAL) ||
  		    (dr->dr_complete == DATAIN_COMPLETE_CONNECTION_RECOVERY)) {
  			iscsit_increment_maxcmdsn(cmd, conn->sess);
  			cmd->stat_sn = conn->stat_sn++;
  			set_statsn = true;
  		} else if (dr->dr_complete ==
  			   DATAIN_COMPLETE_WITHIN_COMMAND_RECOVERY)
  			set_statsn = true;
  	}
  
  	iscsit_build_datain_pdu(cmd, conn, &datain, hdr, set_statsn);
  
  	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, dr, &datain, 0);
  	if (ret < 0)
  		return ret;
  
  	if (dr->dr_complete) {
  		eodr = (cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ?
  				2 : 1;
  		iscsit_free_datain_req(cmd, dr);
  	}
  
  	return eodr;
  }
  
  int
  iscsit_build_logout_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
  			struct iscsi_logout_rsp *hdr)
  {
  	struct iscsi_conn *logout_conn = NULL;
  	struct iscsi_conn_recovery *cr = NULL;
  	struct iscsi_session *sess = conn->sess;
  	/*
  	 * The actual shutting down of Sessions and/or Connections
  	 * for CLOSESESSION and CLOSECONNECTION Logout Requests
  	 * is done in scsi_logout_post_handler().
  	 */
  	switch (cmd->logout_reason) {
  	case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
  		pr_debug("iSCSI session logout successful, setting"
  			" logout response to ISCSI_LOGOUT_SUCCESS.\n");
  		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
  		break;
  	case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
  		if (cmd->logout_response == ISCSI_LOGOUT_CID_NOT_FOUND)
  			break;
  		/*
  		 * For CLOSECONNECTION logout requests carrying
  		 * a matching logout CID -> local CID, the reference
  		 * for the local CID will have been incremented in
  		 * iscsi_logout_closeconnection().
  		 *
  		 * For CLOSECONNECTION logout requests carrying
  		 * a different CID than the connection it arrived
  		 * on, the connection responding to cmd->logout_cid
  		 * is stopped in iscsit_logout_post_handler_diffcid().
  		 */
  
  		pr_debug("iSCSI CID: %hu logout on CID: %hu"
  			" successful.\n", cmd->logout_cid, conn->cid);
  		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
  		break;
  	case ISCSI_LOGOUT_REASON_RECOVERY:
  		if ((cmd->logout_response == ISCSI_LOGOUT_RECOVERY_UNSUPPORTED) ||
  		    (cmd->logout_response == ISCSI_LOGOUT_CLEANUP_FAILED))
  			break;
  		/*
  		 * If the connection is still active from our point of view
  		 * force connection recovery to occur.
  		 */
  		logout_conn = iscsit_get_conn_from_cid_rcfr(sess,
  				cmd->logout_cid);
  		if (logout_conn) {
  			iscsit_connection_reinstatement_rcfr(logout_conn);
  			iscsit_dec_conn_usage_count(logout_conn);
  		}
  
  		cr = iscsit_get_inactive_connection_recovery_entry(
  				conn->sess, cmd->logout_cid);
  		if (!cr) {
  			pr_err("Unable to locate CID: %hu for"
  			" REMOVECONNFORRECOVERY Logout Request.\n",
  				cmd->logout_cid);
  			cmd->logout_response = ISCSI_LOGOUT_CID_NOT_FOUND;
  			break;
  		}
  
  		iscsit_discard_cr_cmds_by_expstatsn(cr, cmd->exp_stat_sn);
  
  		pr_debug("iSCSI REMOVECONNFORRECOVERY logout"
  			" for recovery for CID: %hu on CID: %hu successful.\n",
  				cmd->logout_cid, conn->cid);
  		cmd->logout_response = ISCSI_LOGOUT_SUCCESS;
  		break;
  	default:
  		pr_err("Unknown cmd->logout_reason: 0x%02x\n",
  				cmd->logout_reason);
  		return -1;
  	}
  
  	hdr->opcode		= ISCSI_OP_LOGOUT_RSP;
  	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
  	hdr->response		= cmd->logout_response;
  	hdr->itt		= cmd->init_task_tag;
  	cmd->stat_sn		= conn->stat_sn++;
  	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
  
  	iscsit_increment_maxcmdsn(cmd, conn->sess);
  	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
  	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
  
  	pr_debug("Built Logout Response ITT: 0x%08x StatSN:"
  		" 0x%08x Response: 0x%02x CID: %hu on CID: %hu\n",
  		cmd->init_task_tag, cmd->stat_sn, hdr->response,
  		cmd->logout_cid, conn->cid);
  
  	return 0;
  }
  EXPORT_SYMBOL(iscsit_build_logout_rsp);
  
  static int
  iscsit_send_logout(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
  {
  	int rc;
  
  	rc = iscsit_build_logout_rsp(cmd, conn,
  			(struct iscsi_logout_rsp *)&cmd->pdu[0]);
  	if (rc < 0)
  		return rc;
  
  	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
  }
  
  void
  iscsit_build_nopin_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
  		       struct iscsi_nopin *hdr, bool nopout_response)
  {
  	hdr->opcode		= ISCSI_OP_NOOP_IN;
  	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
          hton24(hdr->dlength, cmd->buf_ptr_size);
  	if (nopout_response)
  		put_unaligned_le64(0xFFFFFFFFFFFFFFFFULL, &hdr->lun);
  	hdr->itt		= cmd->init_task_tag;
  	hdr->ttt		= cpu_to_be32(cmd->targ_xfer_tag);
  	cmd->stat_sn		= (nopout_response) ? conn->stat_sn++ :
  				  conn->stat_sn;
  	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
  
  	if (nopout_response)
  		iscsit_increment_maxcmdsn(cmd, conn->sess);
  
  	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
  	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
  
  	pr_debug("Built NOPIN %s Response ITT: 0x%08x, TTT: 0x%08x,"
  		" StatSN: 0x%08x, Length %u\n", (nopout_response) ?
  		"Solicited" : "Unsolicited", cmd->init_task_tag,
  		cmd->targ_xfer_tag, cmd->stat_sn, cmd->buf_ptr_size);
  }
  EXPORT_SYMBOL(iscsit_build_nopin_rsp);
  
  /*
   *	Unsolicited NOPIN, either requesting a response or not.
   */
  static int iscsit_send_unsolicited_nopin(
  	struct iscsi_cmd *cmd,
  	struct iscsi_conn *conn,
  	int want_response)
  {
  	struct iscsi_nopin *hdr = (struct iscsi_nopin *)&cmd->pdu[0];
  	int ret;
  
  	iscsit_build_nopin_rsp(cmd, conn, hdr, false);
  
  	pr_debug("Sending Unsolicited NOPIN TTT: 0x%08x StatSN:"
  		" 0x%08x CID: %hu\n", hdr->ttt, cmd->stat_sn, conn->cid);
  
  	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
  	if (ret < 0)
  		return ret;
  
  	spin_lock_bh(&cmd->istate_lock);
  	cmd->i_state = want_response ?
  		ISTATE_SENT_NOPIN_WANT_RESPONSE : ISTATE_SENT_STATUS;
  	spin_unlock_bh(&cmd->istate_lock);
  
  	return 0;
  }
  
  static int
  iscsit_send_nopin(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
  {
  	struct iscsi_nopin *hdr = (struct iscsi_nopin *)&cmd->pdu[0];
  
  	iscsit_build_nopin_rsp(cmd, conn, hdr, true);
  
  	/*
  	 * NOPOUT Ping Data is attached to struct iscsi_cmd->buf_ptr.
  	 * NOPOUT DataSegmentLength is at struct iscsi_cmd->buf_ptr_size.
  	 */
  	pr_debug("Echoing back %u bytes of ping data.\n", cmd->buf_ptr_size);
  
  	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
  						     cmd->buf_ptr,
  						     cmd->buf_ptr_size);
  }
  
  static int iscsit_send_r2t(
  	struct iscsi_cmd *cmd,
  	struct iscsi_conn *conn)
  {
  	struct iscsi_r2t *r2t;
  	struct iscsi_r2t_rsp *hdr;
  	int ret;
  
  	r2t = iscsit_get_r2t_from_list(cmd);
  	if (!r2t)
  		return -1;
  
  	hdr			= (struct iscsi_r2t_rsp *) cmd->pdu;
  	memset(hdr, 0, ISCSI_HDR_LEN);
  	hdr->opcode		= ISCSI_OP_R2T;
  	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
  	int_to_scsilun(cmd->se_cmd.orig_fe_lun,
  			(struct scsi_lun *)&hdr->lun);
  	hdr->itt		= cmd->init_task_tag;
  	if (conn->conn_transport->iscsit_get_r2t_ttt)
  		conn->conn_transport->iscsit_get_r2t_ttt(conn, cmd, r2t);
  	else
  		r2t->targ_xfer_tag = session_get_next_ttt(conn->sess);
  	hdr->ttt		= cpu_to_be32(r2t->targ_xfer_tag);
  	hdr->statsn		= cpu_to_be32(conn->stat_sn);
  	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
  	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
  	hdr->r2tsn		= cpu_to_be32(r2t->r2t_sn);
  	hdr->data_offset	= cpu_to_be32(r2t->offset);
  	hdr->data_length	= cpu_to_be32(r2t->xfer_len);
  
  	pr_debug("Built %sR2T, ITT: 0x%08x, TTT: 0x%08x, StatSN:"
  		" 0x%08x, R2TSN: 0x%08x, Offset: %u, DDTL: %u, CID: %hu\n",
  		(!r2t->recovery_r2t) ? "" : "Recovery ", cmd->init_task_tag,
  		r2t->targ_xfer_tag, ntohl(hdr->statsn), r2t->r2t_sn,
  			r2t->offset, r2t->xfer_len, conn->cid);
  
  	spin_lock_bh(&cmd->r2t_lock);
  	r2t->sent_r2t = 1;
  	spin_unlock_bh(&cmd->r2t_lock);
  
  	ret = conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
  	if (ret < 0) {
  		return ret;
  	}
  
  	spin_lock_bh(&cmd->dataout_timeout_lock);
  	iscsit_start_dataout_timer(cmd, conn);
  	spin_unlock_bh(&cmd->dataout_timeout_lock);
  
  	return 0;
  }
  
  /*
   *	@recovery: If called from iscsi_task_reassign_complete_write() for
   *		connection recovery.
   */
  int iscsit_build_r2ts_for_cmd(
  	struct iscsi_conn *conn,
  	struct iscsi_cmd *cmd,
  	bool recovery)
  {
  	int first_r2t = 1;
  	u32 offset = 0, xfer_len = 0;
  
  	spin_lock_bh(&cmd->r2t_lock);
  	if (cmd->cmd_flags & ICF_SENT_LAST_R2T) {
  		spin_unlock_bh(&cmd->r2t_lock);
  		return 0;
  	}
  
  	if (conn->sess->sess_ops->DataSequenceInOrder &&
  	    !recovery)
  		cmd->r2t_offset = max(cmd->r2t_offset, cmd->write_data_done);
  
  	while (cmd->outstanding_r2ts < conn->sess->sess_ops->MaxOutstandingR2T) {
  		if (conn->sess->sess_ops->DataSequenceInOrder) {
  			offset = cmd->r2t_offset;
  
  			if (first_r2t && recovery) {
  				int new_data_end = offset +
  					conn->sess->sess_ops->MaxBurstLength -
  					cmd->next_burst_len;
  
  				if (new_data_end > cmd->se_cmd.data_length)
  					xfer_len = cmd->se_cmd.data_length - offset;
  				else
  					xfer_len =
  						conn->sess->sess_ops->MaxBurstLength -
  						cmd->next_burst_len;
  			} else {
  				int new_data_end = offset +
  					conn->sess->sess_ops->MaxBurstLength;
  
  				if (new_data_end > cmd->se_cmd.data_length)
  					xfer_len = cmd->se_cmd.data_length - offset;
  				else
  					xfer_len = conn->sess->sess_ops->MaxBurstLength;
  			}
  
  			if ((s32)xfer_len < 0) {
  				cmd->cmd_flags |= ICF_SENT_LAST_R2T;
  				break;
  			}
  
  			cmd->r2t_offset += xfer_len;
  
  			if (cmd->r2t_offset == cmd->se_cmd.data_length)
  				cmd->cmd_flags |= ICF_SENT_LAST_R2T;
  		} else {
  			struct iscsi_seq *seq;
  
  			seq = iscsit_get_seq_holder_for_r2t(cmd);
  			if (!seq) {
  				spin_unlock_bh(&cmd->r2t_lock);
  				return -1;
  			}
  
  			offset = seq->offset;
  			xfer_len = seq->xfer_len;
  
  			if (cmd->seq_send_order == cmd->seq_count)
  				cmd->cmd_flags |= ICF_SENT_LAST_R2T;
  		}
  		cmd->outstanding_r2ts++;
  		first_r2t = 0;
  
  		if (iscsit_add_r2t_to_list(cmd, offset, xfer_len, 0, 0) < 0) {
  			spin_unlock_bh(&cmd->r2t_lock);
  			return -1;
  		}
  
  		if (cmd->cmd_flags & ICF_SENT_LAST_R2T)
  			break;
  	}
  	spin_unlock_bh(&cmd->r2t_lock);
  
  	return 0;
  }
  EXPORT_SYMBOL(iscsit_build_r2ts_for_cmd);
  
  void iscsit_build_rsp_pdu(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
  			bool inc_stat_sn, struct iscsi_scsi_rsp *hdr)
  {
  	if (inc_stat_sn)
  		cmd->stat_sn = conn->stat_sn++;
  
  	atomic_long_inc(&conn->sess->rsp_pdus);
  
  	memset(hdr, 0, ISCSI_HDR_LEN);
  	hdr->opcode		= ISCSI_OP_SCSI_CMD_RSP;
  	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
  	if (cmd->se_cmd.se_cmd_flags & SCF_OVERFLOW_BIT) {
  		hdr->flags |= ISCSI_FLAG_CMD_OVERFLOW;
  		hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
  	} else if (cmd->se_cmd.se_cmd_flags & SCF_UNDERFLOW_BIT) {
  		hdr->flags |= ISCSI_FLAG_CMD_UNDERFLOW;
  		hdr->residual_count = cpu_to_be32(cmd->se_cmd.residual_count);
  	}
  	hdr->response		= cmd->iscsi_response;
  	hdr->cmd_status		= cmd->se_cmd.scsi_status;
  	hdr->itt		= cmd->init_task_tag;
  	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
  
  	iscsit_increment_maxcmdsn(cmd, conn->sess);
  	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
  	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
  
  	pr_debug("Built SCSI Response, ITT: 0x%08x, StatSN: 0x%08x,"
  		" Response: 0x%02x, SAM Status: 0x%02x, CID: %hu\n",
  		cmd->init_task_tag, cmd->stat_sn, cmd->se_cmd.scsi_status,
  		cmd->se_cmd.scsi_status, conn->cid);
  }
  EXPORT_SYMBOL(iscsit_build_rsp_pdu);
  
  static int iscsit_send_response(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
  {
  	struct iscsi_scsi_rsp *hdr = (struct iscsi_scsi_rsp *)&cmd->pdu[0];
  	bool inc_stat_sn = (cmd->i_state == ISTATE_SEND_STATUS);
  	void *data_buf = NULL;
  	u32 padding = 0, data_buf_len = 0;
  
  	iscsit_build_rsp_pdu(cmd, conn, inc_stat_sn, hdr);
  
  	/*
  	 * Attach SENSE DATA payload to iSCSI Response PDU
  	 */
  	if (cmd->se_cmd.sense_buffer &&
  	   ((cmd->se_cmd.se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) ||
  	    (cmd->se_cmd.se_cmd_flags & SCF_EMULATED_TASK_SENSE))) {
  		put_unaligned_be16(cmd->se_cmd.scsi_sense_length, cmd->sense_buffer);
  		cmd->se_cmd.scsi_sense_length += sizeof (__be16);
  
  		padding		= -(cmd->se_cmd.scsi_sense_length) & 3;
  		hton24(hdr->dlength, (u32)cmd->se_cmd.scsi_sense_length);
  		data_buf = cmd->sense_buffer;
  		data_buf_len = cmd->se_cmd.scsi_sense_length + padding;
  
  		if (padding) {
  			memset(cmd->sense_buffer +
  				cmd->se_cmd.scsi_sense_length, 0, padding);
  			pr_debug("Adding %u bytes of padding to"
  				" SENSE.\n", padding);
  		}
  
  		pr_debug("Attaching SENSE DATA: %u bytes to iSCSI"
  				" Response PDU\n",
  				cmd->se_cmd.scsi_sense_length);
  	}
  
  	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, data_buf,
  						     data_buf_len);
  }
  
  static u8 iscsit_convert_tcm_tmr_rsp(struct se_tmr_req *se_tmr)
  {
  	switch (se_tmr->response) {
  	case TMR_FUNCTION_COMPLETE:
  		return ISCSI_TMF_RSP_COMPLETE;
  	case TMR_TASK_DOES_NOT_EXIST:
  		return ISCSI_TMF_RSP_NO_TASK;
  	case TMR_LUN_DOES_NOT_EXIST:
  		return ISCSI_TMF_RSP_NO_LUN;
  	case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
  		return ISCSI_TMF_RSP_NOT_SUPPORTED;
  	case TMR_FUNCTION_REJECTED:
  	default:
  		return ISCSI_TMF_RSP_REJECTED;
  	}
  }
  
  void
  iscsit_build_task_mgt_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
  			  struct iscsi_tm_rsp *hdr)
  {
  	struct se_tmr_req *se_tmr = cmd->se_cmd.se_tmr_req;
  
  	hdr->opcode		= ISCSI_OP_SCSI_TMFUNC_RSP;
  	hdr->flags		= ISCSI_FLAG_CMD_FINAL;
  	hdr->response		= iscsit_convert_tcm_tmr_rsp(se_tmr);
  	hdr->itt		= cmd->init_task_tag;
  	cmd->stat_sn		= conn->stat_sn++;
  	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
  
  	iscsit_increment_maxcmdsn(cmd, conn->sess);
  	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
  	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
  
  	pr_debug("Built Task Management Response ITT: 0x%08x,"
  		" StatSN: 0x%08x, Response: 0x%02x, CID: %hu\n",
  		cmd->init_task_tag, cmd->stat_sn, hdr->response, conn->cid);
  }
  EXPORT_SYMBOL(iscsit_build_task_mgt_rsp);
  
  static int
  iscsit_send_task_mgt_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
  {
  	struct iscsi_tm_rsp *hdr = (struct iscsi_tm_rsp *)&cmd->pdu[0];
  
  	iscsit_build_task_mgt_rsp(cmd, conn, hdr);
  
  	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL, NULL, 0);
  }
  
  #define SENDTARGETS_BUF_LIMIT 32768U
  
  static int
  iscsit_build_sendtargets_response(struct iscsi_cmd *cmd,
  				  enum iscsit_transport_type network_transport,
  				  int skip_bytes, bool *completed)
  {
  	char *payload = NULL;
  	struct iscsi_conn *conn = cmd->conn;
  	struct iscsi_portal_group *tpg;
  	struct iscsi_tiqn *tiqn;
  	struct iscsi_tpg_np *tpg_np;
  	int buffer_len, end_of_buf = 0, len = 0, payload_len = 0;
  	int target_name_printed;
  	unsigned char buf[ISCSI_IQN_LEN+12]; /* iqn + "TargetName=" + \0 */
  	unsigned char *text_in = cmd->text_in_ptr, *text_ptr = NULL;
  	bool active;
  
  	buffer_len = min(conn->conn_ops->MaxRecvDataSegmentLength,
  			 SENDTARGETS_BUF_LIMIT);
  
  	payload = kzalloc(buffer_len, GFP_KERNEL);
  	if (!payload)
  		return -ENOMEM;
  
  	/*
  	 * Locate pointer to iqn./eui. string for ICF_SENDTARGETS_SINGLE
  	 * explicit case..
  	 */
  	if (cmd->cmd_flags & ICF_SENDTARGETS_SINGLE) {
  		text_ptr = strchr(text_in, '=');
  		if (!text_ptr) {
  			pr_err("Unable to locate '=' string in text_in:"
  			       " %s\n", text_in);
  			kfree(payload);
  			return -EINVAL;
  		}
  		/*
  		 * Skip over '=' character..
  		 */
  		text_ptr += 1;
  	}
  
  	spin_lock(&tiqn_lock);
  	list_for_each_entry(tiqn, &g_tiqn_list, tiqn_list) {
  		if ((cmd->cmd_flags & ICF_SENDTARGETS_SINGLE) &&
  		     strcmp(tiqn->tiqn, text_ptr)) {
  			continue;
  		}
  
  		target_name_printed = 0;
  
  		spin_lock(&tiqn->tiqn_tpg_lock);
  		list_for_each_entry(tpg, &tiqn->tiqn_tpg_list, tpg_list) {
  
  			/* If demo_mode_discovery=0 and generate_node_acls=0
  			 * (demo mode dislabed) do not return
  			 * TargetName+TargetAddress unless a NodeACL exists.
  			 */
  
  			if ((tpg->tpg_attrib.generate_node_acls == 0) &&
  			    (tpg->tpg_attrib.demo_mode_discovery == 0) &&
  			    (!target_tpg_has_node_acl(&tpg->tpg_se_tpg,
  				cmd->conn->sess->sess_ops->InitiatorName))) {
  				continue;
  			}
  
  			spin_lock(&tpg->tpg_state_lock);
  			active = (tpg->tpg_state == TPG_STATE_ACTIVE);
  			spin_unlock(&tpg->tpg_state_lock);
  
  			if (!active && tpg->tpg_attrib.tpg_enabled_sendtargets)
  				continue;
  
  			spin_lock(&tpg->tpg_np_lock);
  			list_for_each_entry(tpg_np, &tpg->tpg_gnp_list,
  						tpg_np_list) {
  				struct iscsi_np *np = tpg_np->tpg_np;
  				struct sockaddr_storage *sockaddr;
  
  				if (np->np_network_transport != network_transport)
  					continue;
  
  				if (!target_name_printed) {
  					len = sprintf(buf, "TargetName=%s",
  						      tiqn->tiqn);
  					len += 1;
  
  					if ((len + payload_len) > buffer_len) {
  						spin_unlock(&tpg->tpg_np_lock);
  						spin_unlock(&tiqn->tiqn_tpg_lock);
  						end_of_buf = 1;
  						goto eob;
  					}
  
  					if (skip_bytes && len <= skip_bytes) {
  						skip_bytes -= len;
  					} else {
  						memcpy(payload + payload_len, buf, len);
  						payload_len += len;
  						target_name_printed = 1;
  						if (len > skip_bytes)
  							skip_bytes = 0;
  					}
  				}
  
  				if (inet_addr_is_any((struct sockaddr *)&np->np_sockaddr))
  					sockaddr = &conn->local_sockaddr;
  				else
  					sockaddr = &np->np_sockaddr;
  
  				len = sprintf(buf, "TargetAddress="
  					      "%pISpc,%hu",
  					      sockaddr,
  					      tpg->tpgt);
  				len += 1;
  
  				if ((len + payload_len) > buffer_len) {
  					spin_unlock(&tpg->tpg_np_lock);
  					spin_unlock(&tiqn->tiqn_tpg_lock);
  					end_of_buf = 1;
  					goto eob;
  				}
  
  				if (skip_bytes && len <= skip_bytes) {
  					skip_bytes -= len;
  				} else {
  					memcpy(payload + payload_len, buf, len);
  					payload_len += len;
  					if (len > skip_bytes)
  						skip_bytes = 0;
  				}
  			}
  			spin_unlock(&tpg->tpg_np_lock);
  		}
  		spin_unlock(&tiqn->tiqn_tpg_lock);
  eob:
  		if (end_of_buf) {
  			*completed = false;
  			break;
  		}
  
  		if (cmd->cmd_flags & ICF_SENDTARGETS_SINGLE)
  			break;
  	}
  	spin_unlock(&tiqn_lock);
  
  	cmd->buf_ptr = payload;
  
  	return payload_len;
  }
  
  int
  iscsit_build_text_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
  		      struct iscsi_text_rsp *hdr,
  		      enum iscsit_transport_type network_transport)
  {
  	int text_length, padding;
  	bool completed = true;
  
  	text_length = iscsit_build_sendtargets_response(cmd, network_transport,
  							cmd->read_data_done,
  							&completed);
  	if (text_length < 0)
  		return text_length;
  
  	if (completed) {
  		hdr->flags = ISCSI_FLAG_CMD_FINAL;
  	} else {
  		hdr->flags = ISCSI_FLAG_TEXT_CONTINUE;
  		cmd->read_data_done += text_length;
  		if (cmd->targ_xfer_tag == 0xFFFFFFFF)
  			cmd->targ_xfer_tag = session_get_next_ttt(conn->sess);
  	}
  	hdr->opcode = ISCSI_OP_TEXT_RSP;
  	padding = ((-text_length) & 3);
  	hton24(hdr->dlength, text_length);
  	hdr->itt = cmd->init_task_tag;
  	hdr->ttt = cpu_to_be32(cmd->targ_xfer_tag);
  	cmd->stat_sn = conn->stat_sn++;
  	hdr->statsn = cpu_to_be32(cmd->stat_sn);
  
  	iscsit_increment_maxcmdsn(cmd, conn->sess);
  	/*
  	 * Reset maxcmdsn_inc in multi-part text payload exchanges to
  	 * correctly increment MaxCmdSN for each response answering a
  	 * non immediate text request with a valid CmdSN.
  	 */
  	cmd->maxcmdsn_inc = 0;
  	hdr->exp_cmdsn = cpu_to_be32(conn->sess->exp_cmd_sn);
  	hdr->max_cmdsn = cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
  
  	pr_debug("Built Text Response: ITT: 0x%08x, TTT: 0x%08x, StatSN: 0x%08x,"
  		" Length: %u, CID: %hu F: %d C: %d\n", cmd->init_task_tag,
  		cmd->targ_xfer_tag, cmd->stat_sn, text_length, conn->cid,
  		!!(hdr->flags & ISCSI_FLAG_CMD_FINAL),
  		!!(hdr->flags & ISCSI_FLAG_TEXT_CONTINUE));
  
  	return text_length + padding;
  }
  EXPORT_SYMBOL(iscsit_build_text_rsp);
  
  static int iscsit_send_text_rsp(
  	struct iscsi_cmd *cmd,
  	struct iscsi_conn *conn)
  {
  	struct iscsi_text_rsp *hdr = (struct iscsi_text_rsp *)cmd->pdu;
  	int text_length;
  
  	text_length = iscsit_build_text_rsp(cmd, conn, hdr,
  				conn->conn_transport->transport_type);
  	if (text_length < 0)
  		return text_length;
  
  	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
  						     cmd->buf_ptr,
  						     text_length);
  }
  
  void
  iscsit_build_reject(struct iscsi_cmd *cmd, struct iscsi_conn *conn,
  		    struct iscsi_reject *hdr)
  {
  	hdr->opcode		= ISCSI_OP_REJECT;
  	hdr->reason		= cmd->reject_reason;
  	hdr->flags		|= ISCSI_FLAG_CMD_FINAL;
  	hton24(hdr->dlength, ISCSI_HDR_LEN);
  	hdr->ffffffff		= cpu_to_be32(0xffffffff);
  	cmd->stat_sn		= conn->stat_sn++;
  	hdr->statsn		= cpu_to_be32(cmd->stat_sn);
  	hdr->exp_cmdsn		= cpu_to_be32(conn->sess->exp_cmd_sn);
  	hdr->max_cmdsn		= cpu_to_be32((u32) atomic_read(&conn->sess->max_cmd_sn));
  
  }
  EXPORT_SYMBOL(iscsit_build_reject);
  
  static int iscsit_send_reject(
  	struct iscsi_cmd *cmd,
  	struct iscsi_conn *conn)
  {
  	struct iscsi_reject *hdr = (struct iscsi_reject *)&cmd->pdu[0];
  
  	iscsit_build_reject(cmd, conn, hdr);
  
  	pr_debug("Built Reject PDU StatSN: 0x%08x, Reason: 0x%02x,"
  		" CID: %hu\n", ntohl(hdr->statsn), hdr->reason, conn->cid);
  
  	return conn->conn_transport->iscsit_xmit_pdu(conn, cmd, NULL,
  						     cmd->buf_ptr,
  						     ISCSI_HDR_LEN);
  }
  
  void iscsit_thread_get_cpumask(struct iscsi_conn *conn)
  {
  	int ord, cpu;
  	/*
  	 * bitmap_id is assigned from iscsit_global->ts_bitmap from
  	 * within iscsit_start_kthreads()
  	 *
  	 * Here we use bitmap_id to determine which CPU that this
  	 * iSCSI connection's RX/TX threads will be scheduled to
  	 * execute upon.
  	 */
  	ord = conn->bitmap_id % cpumask_weight(cpu_online_mask);
  	for_each_online_cpu(cpu) {
  		if (ord-- == 0) {
  			cpumask_set_cpu(cpu, conn->conn_cpumask);
  			return;
  		}
  	}
  	/*
  	 * This should never be reached..
  	 */
  	dump_stack();
  	cpumask_setall(conn->conn_cpumask);
  }
  
  int
  iscsit_immediate_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state)
  {
  	int ret;
  
  	switch (state) {
  	case ISTATE_SEND_R2T:
  		ret = iscsit_send_r2t(cmd, conn);
  		if (ret < 0)
  			goto err;
  		break;
  	case ISTATE_REMOVE:
  		spin_lock_bh(&conn->cmd_lock);
  		list_del_init(&cmd->i_conn_node);
  		spin_unlock_bh(&conn->cmd_lock);
  
  		iscsit_free_cmd(cmd, false);
  		break;
  	case ISTATE_SEND_NOPIN_WANT_RESPONSE:
  		iscsit_mod_nopin_response_timer(conn);
  		ret = iscsit_send_unsolicited_nopin(cmd, conn, 1);
  		if (ret < 0)
  			goto err;
  		break;
  	case ISTATE_SEND_NOPIN_NO_RESPONSE:
  		ret = iscsit_send_unsolicited_nopin(cmd, conn, 0);
  		if (ret < 0)
  			goto err;
  		break;
  	default:
  		pr_err("Unknown Opcode: 0x%02x ITT:"
  		       " 0x%08x, i_state: %d on CID: %hu\n",
  		       cmd->iscsi_opcode, cmd->init_task_tag, state,
  		       conn->cid);
  		goto err;
  	}
  
  	return 0;
  
  err:
  	return -1;
  }
  EXPORT_SYMBOL(iscsit_immediate_queue);
  
  static int
  iscsit_handle_immediate_queue(struct iscsi_conn *conn)
  {
  	struct iscsit_transport *t = conn->conn_transport;
  	struct iscsi_queue_req *qr;
  	struct iscsi_cmd *cmd;
  	u8 state;
  	int ret;
  
  	while ((qr = iscsit_get_cmd_from_immediate_queue(conn))) {
  		atomic_set(&conn->check_immediate_queue, 0);
  		cmd = qr->cmd;
  		state = qr->state;
  		kmem_cache_free(lio_qr_cache, qr);
  
  		ret = t->iscsit_immediate_queue(conn, cmd, state);
  		if (ret < 0)
  			return ret;
  	}
  
  	return 0;
  }
  
  int
  iscsit_response_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state)
  {
  	int ret;
  
  check_rsp_state:
  	switch (state) {
  	case ISTATE_SEND_DATAIN:
  		ret = iscsit_send_datain(cmd, conn);
  		if (ret < 0)
  			goto err;
  		else if (!ret)
  			/* more drs */
  			goto check_rsp_state;
  		else if (ret == 1) {
  			/* all done */
  			spin_lock_bh(&cmd->istate_lock);
  			cmd->i_state = ISTATE_SENT_STATUS;
  			spin_unlock_bh(&cmd->istate_lock);
  
  			if (atomic_read(&conn->check_immediate_queue))
  				return 1;
  
  			return 0;
  		} else if (ret == 2) {
  			/* Still must send status,
  			   SCF_TRANSPORT_TASK_SENSE was set */
  			spin_lock_bh(&cmd->istate_lock);
  			cmd->i_state = ISTATE_SEND_STATUS;
  			spin_unlock_bh(&cmd->istate_lock);
  			state = ISTATE_SEND_STATUS;
  			goto check_rsp_state;
  		}
  
  		break;
  	case ISTATE_SEND_STATUS:
  	case ISTATE_SEND_STATUS_RECOVERY:
  		ret = iscsit_send_response(cmd, conn);
  		break;
  	case ISTATE_SEND_LOGOUTRSP:
  		ret = iscsit_send_logout(cmd, conn);
  		break;
  	case ISTATE_SEND_ASYNCMSG:
  		ret = iscsit_send_conn_drop_async_message(
  			cmd, conn);
  		break;
  	case ISTATE_SEND_NOPIN:
  		ret = iscsit_send_nopin(cmd, conn);
  		break;
  	case ISTATE_SEND_REJECT:
  		ret = iscsit_send_reject(cmd, conn);
  		break;
  	case ISTATE_SEND_TASKMGTRSP:
  		ret = iscsit_send_task_mgt_rsp(cmd, conn);
  		if (ret != 0)
  			break;
  		ret = iscsit_tmr_post_handler(cmd, conn);
  		if (ret != 0)
  			iscsit_fall_back_to_erl0(conn->sess);
  		break;
  	case ISTATE_SEND_TEXTRSP:
  		ret = iscsit_send_text_rsp(cmd, conn);
  		break;
  	default:
  		pr_err("Unknown Opcode: 0x%02x ITT:"
  		       " 0x%08x, i_state: %d on CID: %hu\n",
  		       cmd->iscsi_opcode, cmd->init_task_tag,
  		       state, conn->cid);
  		goto err;
  	}
  	if (ret < 0)
  		goto err;
  
  	switch (state) {
  	case ISTATE_SEND_LOGOUTRSP:
  		if (!iscsit_logout_post_handler(cmd, conn))
  			return -ECONNRESET;
  		/* fall through */
  	case ISTATE_SEND_STATUS:
  	case ISTATE_SEND_ASYNCMSG:
  	case ISTATE_SEND_NOPIN:
  	case ISTATE_SEND_STATUS_RECOVERY:
  	case ISTATE_SEND_TEXTRSP:
  	case ISTATE_SEND_TASKMGTRSP:
  	case ISTATE_SEND_REJECT:
  		spin_lock_bh(&cmd->istate_lock);
  		cmd->i_state = ISTATE_SENT_STATUS;
  		spin_unlock_bh(&cmd->istate_lock);
  		break;
  	default:
  		pr_err("Unknown Opcode: 0x%02x ITT:"
  		       " 0x%08x, i_state: %d on CID: %hu\n",
  		       cmd->iscsi_opcode, cmd->init_task_tag,
  		       cmd->i_state, conn->cid);
  		goto err;
  	}
  
  	if (atomic_read(&conn->check_immediate_queue))
  		return 1;
  
  	return 0;
  
  err:
  	return -1;
  }
  EXPORT_SYMBOL(iscsit_response_queue);
  
  static int iscsit_handle_response_queue(struct iscsi_conn *conn)
  {
  	struct iscsit_transport *t = conn->conn_transport;
  	struct iscsi_queue_req *qr;
  	struct iscsi_cmd *cmd;
  	u8 state;
  	int ret;
  
  	while ((qr = iscsit_get_cmd_from_response_queue(conn))) {
  		cmd = qr->cmd;
  		state = qr->state;
  		kmem_cache_free(lio_qr_cache, qr);
  
  		ret = t->iscsit_response_queue(conn, cmd, state);
  		if (ret == 1 || ret < 0)
  			return ret;
  	}
  
  	return 0;
  }
  
  int iscsi_target_tx_thread(void *arg)
  {
  	int ret = 0;
  	struct iscsi_conn *conn = arg;
  	bool conn_freed = false;
  
  	/*
  	 * Allow ourselves to be interrupted by SIGINT so that a
  	 * connection recovery / failure event can be triggered externally.
  	 */
  	allow_signal(SIGINT);
  
  	while (!kthread_should_stop()) {
  		/*
  		 * Ensure that both TX and RX per connection kthreads
  		 * are scheduled to run on the same CPU.
  		 */
  		iscsit_thread_check_cpumask(conn, current, 1);
  
  		wait_event_interruptible(conn->queues_wq,
  					 !iscsit_conn_all_queues_empty(conn));
  
  		if (signal_pending(current))
  			goto transport_err;
  
  get_immediate:
  		ret = iscsit_handle_immediate_queue(conn);
  		if (ret < 0)
  			goto transport_err;
  
  		ret = iscsit_handle_response_queue(conn);
  		if (ret == 1) {
  			goto get_immediate;
  		} else if (ret == -ECONNRESET) {
  			conn_freed = true;
  			goto out;
  		} else if (ret < 0) {
  			goto transport_err;
  		}
  	}
  
  transport_err:
  	/*
  	 * Avoid the normal connection failure code-path if this connection
  	 * is still within LOGIN mode, and iscsi_np process context is
  	 * responsible for cleaning up the early connection failure.
  	 */
  	if (conn->conn_state != TARG_CONN_STATE_IN_LOGIN)
  		iscsit_take_action_for_connection_exit(conn, &conn_freed);
  out:
  	if (!conn_freed) {
  		while (!kthread_should_stop()) {
  			msleep(100);
  		}
  	}
  	return 0;
  }
  
  static int iscsi_target_rx_opcode(struct iscsi_conn *conn, unsigned char *buf)
  {
  	struct iscsi_hdr *hdr = (struct iscsi_hdr *)buf;
  	struct iscsi_cmd *cmd;
  	int ret = 0;
  
  	switch (hdr->opcode & ISCSI_OPCODE_MASK) {
  	case ISCSI_OP_SCSI_CMD:
  		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
  		if (!cmd)
  			goto reject;
  
  		ret = iscsit_handle_scsi_cmd(conn, cmd, buf);
  		break;
  	case ISCSI_OP_SCSI_DATA_OUT:
  		ret = iscsit_handle_data_out(conn, buf);
  		break;
  	case ISCSI_OP_NOOP_OUT:
  		cmd = NULL;
  		if (hdr->ttt == cpu_to_be32(0xFFFFFFFF)) {
  			cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
  			if (!cmd)
  				goto reject;
  		}
  		ret = iscsit_handle_nop_out(conn, cmd, buf);
  		break;
  	case ISCSI_OP_SCSI_TMFUNC:
  		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
  		if (!cmd)
  			goto reject;
  
  		ret = iscsit_handle_task_mgt_cmd(conn, cmd, buf);
  		break;
  	case ISCSI_OP_TEXT:
  		if (hdr->ttt != cpu_to_be32(0xFFFFFFFF)) {
  			cmd = iscsit_find_cmd_from_itt(conn, hdr->itt);
  			if (!cmd)
  				goto reject;
  		} else {
  			cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
  			if (!cmd)
  				goto reject;
  		}
  
  		ret = iscsit_handle_text_cmd(conn, cmd, buf);
  		break;
  	case ISCSI_OP_LOGOUT:
  		cmd = iscsit_allocate_cmd(conn, TASK_INTERRUPTIBLE);
  		if (!cmd)
  			goto reject;
  
  		ret = iscsit_handle_logout_cmd(conn, cmd, buf);
  		if (ret > 0)
  			wait_for_completion_timeout(&conn->conn_logout_comp,
  					SECONDS_FOR_LOGOUT_COMP * HZ);
  		break;
  	case ISCSI_OP_SNACK:
  		ret = iscsit_handle_snack(conn, buf);
  		break;
  	default:
  		pr_err("Got unknown iSCSI OpCode: 0x%02x\n", hdr->opcode);
  		if (!conn->sess->sess_ops->ErrorRecoveryLevel) {
  			pr_err("Cannot recover from unknown"
  			" opcode while ERL=0, closing iSCSI connection.\n");
  			return -1;
  		}
  		pr_err("Unable to recover from unknown opcode while OFMarker=No,"
  		       " closing iSCSI connection.\n");
  		ret = -1;
  		break;
  	}
  
  	return ret;
  reject:
  	return iscsit_add_reject(conn, ISCSI_REASON_BOOKMARK_NO_RESOURCES, buf);
  }
  
  static bool iscsi_target_check_conn_state(struct iscsi_conn *conn)
  {
  	bool ret;
  
  	spin_lock_bh(&conn->state_lock);
  	ret = (conn->conn_state != TARG_CONN_STATE_LOGGED_IN);
  	spin_unlock_bh(&conn->state_lock);
  
  	return ret;
  }
  
  static void iscsit_get_rx_pdu(struct iscsi_conn *conn)
  {
  	int ret;
  	u8 *buffer, opcode;
  	u32 checksum = 0, digest = 0;
  	struct kvec iov;
  
  	buffer = kcalloc(ISCSI_HDR_LEN, sizeof(*buffer), GFP_KERNEL);
  	if (!buffer)
  		return;
  
  	while (!kthread_should_stop()) {
  		/*
  		 * Ensure that both TX and RX per connection kthreads
  		 * are scheduled to run on the same CPU.
  		 */
  		iscsit_thread_check_cpumask(conn, current, 0);
  
  		memset(&iov, 0, sizeof(struct kvec));
  
  		iov.iov_base	= buffer;
  		iov.iov_len	= ISCSI_HDR_LEN;
  
  		ret = rx_data(conn, &iov, 1, ISCSI_HDR_LEN);
  		if (ret != ISCSI_HDR_LEN) {
  			iscsit_rx_thread_wait_for_tcp(conn);
  			break;
  		}
  
  		if (conn->conn_ops->HeaderDigest) {
  			iov.iov_base	= &digest;
  			iov.iov_len	= ISCSI_CRC_LEN;
  
  			ret = rx_data(conn, &iov, 1, ISCSI_CRC_LEN);
  			if (ret != ISCSI_CRC_LEN) {
  				iscsit_rx_thread_wait_for_tcp(conn);
  				break;
  			}
  
  			iscsit_do_crypto_hash_buf(conn->conn_rx_hash, buffer,
  						  ISCSI_HDR_LEN, 0, NULL,
  						  &checksum);
  
  			if (digest != checksum) {
  				pr_err("HeaderDigest CRC32C failed,"
  					" received 0x%08x, computed 0x%08x\n",
  					digest, checksum);
  				/*
  				 * Set the PDU to 0xff so it will intentionally
  				 * hit default in the switch below.
  				 */
  				memset(buffer, 0xff, ISCSI_HDR_LEN);
  				atomic_long_inc(&conn->sess->conn_digest_errors);
  			} else {
  				pr_debug("Got HeaderDigest CRC32C"
  						" 0x%08x\n", checksum);
  			}
  		}
  
  		if (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT)
  			break;
  
  		opcode = buffer[0] & ISCSI_OPCODE_MASK;
  
  		if (conn->sess->sess_ops->SessionType &&
  		   ((!(opcode & ISCSI_OP_TEXT)) ||
  		    (!(opcode & ISCSI_OP_LOGOUT)))) {
  			pr_err("Received illegal iSCSI Opcode: 0x%02x"
  			" while in Discovery Session, rejecting.\n", opcode);
  			iscsit_add_reject(conn, ISCSI_REASON_PROTOCOL_ERROR,
  					  buffer);
  			break;
  		}
  
  		ret = iscsi_target_rx_opcode(conn, buffer);
  		if (ret < 0)
  			break;
  	}
  
  	kfree(buffer);
  }
  
  int iscsi_target_rx_thread(void *arg)
  {
  	int rc;
  	struct iscsi_conn *conn = arg;
  	bool conn_freed = false;
  
  	/*
  	 * Allow ourselves to be interrupted by SIGINT so that a
  	 * connection recovery / failure event can be triggered externally.
  	 */
  	allow_signal(SIGINT);
  	/*
  	 * Wait for iscsi_post_login_handler() to complete before allowing
  	 * incoming iscsi/tcp socket I/O, and/or failing the connection.
  	 */
  	rc = wait_for_completion_interruptible(&conn->rx_login_comp);
  	if (rc < 0 || iscsi_target_check_conn_state(conn))
  		goto out;
  
  	if (!conn->conn_transport->iscsit_get_rx_pdu)
  		return 0;
  
  	conn->conn_transport->iscsit_get_rx_pdu(conn);
  
  	if (!signal_pending(current))
  		atomic_set(&conn->transport_failed, 1);
  	iscsit_take_action_for_connection_exit(conn, &conn_freed);
  
  out:
  	if (!conn_freed) {
  		while (!kthread_should_stop()) {
  			msleep(100);
  		}
  	}
  
  	return 0;
  }
  
  static void iscsit_release_commands_from_conn(struct iscsi_conn *conn)
  {
  	LIST_HEAD(tmp_list);
  	struct iscsi_cmd *cmd = NULL, *cmd_tmp = NULL;
  	struct iscsi_session *sess = conn->sess;
  	/*
  	 * We expect this function to only ever be called from either RX or TX
  	 * thread context via iscsit_close_connection() once the other context
  	 * has been reset -> returned sleeping pre-handler state.
  	 */
  	spin_lock_bh(&conn->cmd_lock);
  	list_splice_init(&conn->conn_cmd_list, &tmp_list);
  
  	list_for_each_entry(cmd, &tmp_list, i_conn_node) {
  		struct se_cmd *se_cmd = &cmd->se_cmd;
  
  		if (se_cmd->se_tfo != NULL) {
  			spin_lock_irq(&se_cmd->t_state_lock);
  			se_cmd->transport_state |= CMD_T_FABRIC_STOP;
  			spin_unlock_irq(&se_cmd->t_state_lock);
  		}
  	}
  	spin_unlock_bh(&conn->cmd_lock);
  
  	list_for_each_entry_safe(cmd, cmd_tmp, &tmp_list, i_conn_node) {
  		list_del_init(&cmd->i_conn_node);
  
  		iscsit_increment_maxcmdsn(cmd, sess);
  		iscsit_free_cmd(cmd, true);
  
  	}
  }
  
  static void iscsit_stop_timers_for_cmds(
  	struct iscsi_conn *conn)
  {
  	struct iscsi_cmd *cmd;
  
  	spin_lock_bh(&conn->cmd_lock);
  	list_for_each_entry(cmd, &conn->conn_cmd_list, i_conn_node) {
  		if (cmd->data_direction == DMA_TO_DEVICE)
  			iscsit_stop_dataout_timer(cmd);
  	}
  	spin_unlock_bh(&conn->cmd_lock);
  }
  
  int iscsit_close_connection(
  	struct iscsi_conn *conn)
  {
  	int conn_logout = (conn->conn_state == TARG_CONN_STATE_IN_LOGOUT);
  	struct iscsi_session	*sess = conn->sess;
  
  	pr_debug("Closing iSCSI connection CID %hu on SID:"
  		" %u\n", conn->cid, sess->sid);
  	/*
  	 * Always up conn_logout_comp for the traditional TCP and HW_OFFLOAD
  	 * case just in case the RX Thread in iscsi_target_rx_opcode() is
  	 * sleeping and the logout response never got sent because the
  	 * connection failed.
  	 *
  	 * However for iser-target, isert_wait4logout() is using conn_logout_comp
  	 * to signal logout response TX interrupt completion.  Go ahead and skip
  	 * this for iser since isert_rx_opcode() does not wait on logout failure,
  	 * and to avoid iscsi_conn pointer dereference in iser-target code.
  	 */
  	if (!conn->conn_transport->rdma_shutdown)
  		complete(&conn->conn_logout_comp);
  
  	if (!strcmp(current->comm, ISCSI_RX_THREAD_NAME)) {
  		if (conn->tx_thread &&
  		    cmpxchg(&conn->tx_thread_active, true, false)) {
  			send_sig(SIGINT, conn->tx_thread, 1);
  			kthread_stop(conn->tx_thread);
  		}
  	} else if (!strcmp(current->comm, ISCSI_TX_THREAD_NAME)) {
  		if (conn->rx_thread &&
  		    cmpxchg(&conn->rx_thread_active, true, false)) {
  			send_sig(SIGINT, conn->rx_thread, 1);
  			kthread_stop(conn->rx_thread);
  		}
  	}
  
  	spin_lock(&iscsit_global->ts_bitmap_lock);
  	bitmap_release_region(iscsit_global->ts_bitmap, conn->bitmap_id,
  			      get_order(1));
  	spin_unlock(&iscsit_global->ts_bitmap_lock);
  
  	iscsit_stop_timers_for_cmds(conn);
  	iscsit_stop_nopin_response_timer(conn);
  	iscsit_stop_nopin_timer(conn);
  
  	if (conn->conn_transport->iscsit_wait_conn)
  		conn->conn_transport->iscsit_wait_conn(conn);
  
  	/*
  	 * During Connection recovery drop unacknowledged out of order
  	 * commands for this connection, and prepare the other commands
  	 * for reallegiance.
  	 *
  	 * During normal operation clear the out of order commands (but
  	 * do not free the struct iscsi_ooo_cmdsn's) and release all
  	 * struct iscsi_cmds.
  	 */
  	if (atomic_read(&conn->connection_recovery)) {
  		iscsit_discard_unacknowledged_ooo_cmdsns_for_conn(conn);
  		iscsit_prepare_cmds_for_reallegiance(conn);
  	} else {
  		iscsit_clear_ooo_cmdsns_for_conn(conn);
  		iscsit_release_commands_from_conn(conn);
  	}
  	iscsit_free_queue_reqs_for_conn(conn);
  
  	/*
  	 * Handle decrementing session or connection usage count if
  	 * a logout response was not able to be sent because the
  	 * connection failed.  Fall back to Session Recovery here.
  	 */
  	if (atomic_read(&conn->conn_logout_remove)) {
  		if (conn->conn_logout_reason == ISCSI_LOGOUT_REASON_CLOSE_SESSION) {
  			iscsit_dec_conn_usage_count(conn);
  			iscsit_dec_session_usage_count(sess);
  		}
  		if (conn->conn_logout_reason == ISCSI_LOGOUT_REASON_CLOSE_CONNECTION)
  			iscsit_dec_conn_usage_count(conn);
  
  		atomic_set(&conn->conn_logout_remove, 0);
  		atomic_set(&sess->session_reinstatement, 0);
  		atomic_set(&sess->session_fall_back_to_erl0, 1);
  	}
  
  	spin_lock_bh(&sess->conn_lock);
  	list_del(&conn->conn_list);
  
  	/*
  	 * Attempt to let the Initiator know this connection failed by
  	 * sending an Connection Dropped Async Message on another
  	 * active connection.
  	 */
  	if (atomic_read(&conn->connection_recovery))
  		iscsit_build_conn_drop_async_message(conn);
  
  	spin_unlock_bh(&sess->conn_lock);
  
  	/*
  	 * If connection reinstatement is being performed on this connection,
  	 * up the connection reinstatement semaphore that is being blocked on
  	 * in iscsit_cause_connection_reinstatement().
  	 */
  	spin_lock_bh(&conn->state_lock);
  	if (atomic_read(&conn->sleep_on_conn_wait_comp)) {
  		spin_unlock_bh(&conn->state_lock);
  		complete(&conn->conn_wait_comp);
  		wait_for_completion(&conn->conn_post_wait_comp);
  		spin_lock_bh(&conn->state_lock);
  	}
  
  	/*
  	 * If connection reinstatement is being performed on this connection
  	 * by receiving a REMOVECONNFORRECOVERY logout request, up the
  	 * connection wait rcfr semaphore that is being blocked on
  	 * an iscsit_connection_reinstatement_rcfr().
  	 */
  	if (atomic_read(&conn->connection_wait_rcfr)) {
  		spin_unlock_bh(&conn->state_lock);
  		complete(&conn->conn_wait_rcfr_comp);
  		wait_for_completion(&conn->conn_post_wait_comp);
  		spin_lock_bh(&conn->state_lock);
  	}
  	atomic_set(&conn->connection_reinstatement, 1);
  	spin_unlock_bh(&conn->state_lock);
  
  	/*
  	 * If any other processes are accessing this connection pointer we
  	 * must wait until they have completed.
  	 */
  	iscsit_check_conn_usage_count(conn);
  
  	ahash_request_free(conn->conn_tx_hash);
  	if (conn->conn_rx_hash) {
  		struct crypto_ahash *tfm;
  
  		tfm = crypto_ahash_reqtfm(conn->conn_rx_hash);
  		ahash_request_free(conn->conn_rx_hash);
  		crypto_free_ahash(tfm);
  	}
  
  	if (conn->sock)
  		sock_release(conn->sock);
  
  	if (conn->conn_transport->iscsit_free_conn)
  		conn->conn_transport->iscsit_free_conn(conn);
  
  	pr_debug("Moving to TARG_CONN_STATE_FREE.\n");
  	conn->conn_state = TARG_CONN_STATE_FREE;
  	iscsit_free_conn(conn);
  
  	spin_lock_bh(&sess->conn_lock);
  	atomic_dec(&sess->nconn);
  	pr_debug("Decremented iSCSI connection count to %hu from node:"
  		" %s\n", atomic_read(&sess->nconn),
  		sess->sess_ops->InitiatorName);
  	/*
  	 * Make sure that if one connection fails in an non ERL=2 iSCSI
  	 * Session that they all fail.
  	 */
  	if ((sess->sess_ops->ErrorRecoveryLevel != 2) && !conn_logout &&
  	     !atomic_read(&sess->session_logout))
  		atomic_set(&sess->session_fall_back_to_erl0, 1);
  
  	/*
  	 * If this was not the last connection in the session, and we are
  	 * performing session reinstatement or falling back to ERL=0, call
  	 * iscsit_stop_session() without sleeping to shutdown the other
  	 * active connections.
  	 */
  	if (atomic_read(&sess->nconn)) {
  		if (!atomic_read(&sess->session_reinstatement) &&
  		    !atomic_read(&sess->session_fall_back_to_erl0)) {
  			spin_unlock_bh(&sess->conn_lock);
  			return 0;
  		}
  		if (!atomic_read(&sess->session_stop_active)) {
  			atomic_set(&sess->session_stop_active, 1);
  			spin_unlock_bh(&sess->conn_lock);
  			iscsit_stop_session(sess, 0, 0);
  			return 0;
  		}
  		spin_unlock_bh(&sess->conn_lock);
  		return 0;
  	}
  
  	/*
  	 * If this was the last connection in the session and one of the
  	 * following is occurring:
  	 *
  	 * Session Reinstatement is not being performed, and are falling back
  	 * to ERL=0 call iscsit_close_session().
  	 *
  	 * Session Logout was requested.  iscsit_close_session() will be called
  	 * elsewhere.
  	 *
  	 * Session Continuation is not being performed, start the Time2Retain
  	 * handler and check if sleep_on_sess_wait_sem is active.
  	 */
  	if (!atomic_read(&sess->session_reinstatement) &&
  	     atomic_read(&sess->session_fall_back_to_erl0)) {
  		spin_unlock_bh(&sess->conn_lock);
  		iscsit_close_session(sess);
  
  		return 0;
  	} else if (atomic_read(&sess->session_logout)) {
  		pr_debug("Moving to TARG_SESS_STATE_FREE.\n");
  		sess->session_state = TARG_SESS_STATE_FREE;
  		spin_unlock_bh(&sess->conn_lock);
  
  		if (atomic_read(&sess->sleep_on_sess_wait_comp))
  			complete(&sess->session_wait_comp);
  
  		return 0;
  	} else {
  		pr_debug("Moving to TARG_SESS_STATE_FAILED.\n");
  		sess->session_state = TARG_SESS_STATE_FAILED;
  
  		if (!atomic_read(&sess->session_continuation)) {
  			spin_unlock_bh(&sess->conn_lock);
  			iscsit_start_time2retain_handler(sess);
  		} else
  			spin_unlock_bh(&sess->conn_lock);
  
  		if (atomic_read(&sess->sleep_on_sess_wait_comp))
  			complete(&sess->session_wait_comp);
  
  		return 0;
  	}
  }
  
  /*
   * If the iSCSI Session for the iSCSI Initiator Node exists,
   * forcefully shutdown the iSCSI NEXUS.
   */
  int iscsit_close_session(struct iscsi_session *sess)
  {
  	struct iscsi_portal_group *tpg = sess->tpg;
  	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
  
  	if (atomic_read(&sess->nconn)) {
  		pr_err("%d connection(s) still exist for iSCSI session"
  			" to %s\n", atomic_read(&sess->nconn),
  			sess->sess_ops->InitiatorName);
  		BUG();
  	}
  
  	spin_lock_bh(&se_tpg->session_lock);
  	atomic_set(&sess->session_logout, 1);
  	atomic_set(&sess->session_reinstatement, 1);
  	iscsit_stop_time2retain_timer(sess);
  	spin_unlock_bh(&se_tpg->session_lock);
  
  	/*
  	 * transport_deregister_session_configfs() will clear the
  	 * struct se_node_acl->nacl_sess pointer now as a iscsi_np process context
  	 * can be setting it again with __transport_register_session() in
  	 * iscsi_post_login_handler() again after the iscsit_stop_session()
  	 * completes in iscsi_np context.
  	 */
  	transport_deregister_session_configfs(sess->se_sess);
  
  	/*
  	 * If any other processes are accessing this session pointer we must
  	 * wait until they have completed.  If we are in an interrupt (the
  	 * time2retain handler) and contain and active session usage count we
  	 * restart the timer and exit.
  	 */
  	if (!in_interrupt()) {
  		if (iscsit_check_session_usage_count(sess) == 1)
  			iscsit_stop_session(sess, 1, 1);
  	} else {
  		if (iscsit_check_session_usage_count(sess) == 2) {
  			atomic_set(&sess->session_logout, 0);
  			iscsit_start_time2retain_handler(sess);
  			return 0;
  		}
  	}
  
  	transport_deregister_session(sess->se_sess);
  
  	if (sess->sess_ops->ErrorRecoveryLevel == 2)
  		iscsit_free_connection_recovery_entries(sess);
  
  	iscsit_free_all_ooo_cmdsns(sess);
  
  	spin_lock_bh(&se_tpg->session_lock);
  	pr_debug("Moving to TARG_SESS_STATE_FREE.\n");
  	sess->session_state = TARG_SESS_STATE_FREE;
  	pr_debug("Released iSCSI session from node: %s\n",
  			sess->sess_ops->InitiatorName);
  	tpg->nsessions--;
  	if (tpg->tpg_tiqn)
  		tpg->tpg_tiqn->tiqn_nsessions--;
  
  	pr_debug("Decremented number of active iSCSI Sessions on"
  		" iSCSI TPG: %hu to %u\n", tpg->tpgt, tpg->nsessions);
  
  	ida_free(&sess_ida, sess->session_index);
  	kfree(sess->sess_ops);
  	sess->sess_ops = NULL;
  	spin_unlock_bh(&se_tpg->session_lock);
  
  	kfree(sess);
  	return 0;
  }
  
  static void iscsit_logout_post_handler_closesession(
  	struct iscsi_conn *conn)
  {
  	struct iscsi_session *sess = conn->sess;
  	int sleep = 1;
  	/*
  	 * Traditional iscsi/tcp will invoke this logic from TX thread
  	 * context during session logout, so clear tx_thread_active and
  	 * sleep if iscsit_close_connection() has not already occured.
  	 *
  	 * Since iser-target invokes this logic from it's own workqueue,
  	 * always sleep waiting for RX/TX thread shutdown to complete
  	 * within iscsit_close_connection().
  	 */
  	if (!conn->conn_transport->rdma_shutdown) {
  		sleep = cmpxchg(&conn->tx_thread_active, true, false);
  		if (!sleep)
  			return;
  	}
  
  	atomic_set(&conn->conn_logout_remove, 0);
  	complete(&conn->conn_logout_comp);
  
  	iscsit_dec_conn_usage_count(conn);
  	iscsit_stop_session(sess, sleep, sleep);
  	iscsit_dec_session_usage_count(sess);
  	iscsit_close_session(sess);
  }
  
  static void iscsit_logout_post_handler_samecid(
  	struct iscsi_conn *conn)
  {
  	int sleep = 1;
  
  	if (!conn->conn_transport->rdma_shutdown) {
  		sleep = cmpxchg(&conn->tx_thread_active, true, false);
  		if (!sleep)
  			return;
  	}
  
  	atomic_set(&conn->conn_logout_remove, 0);
  	complete(&conn->conn_logout_comp);
  
  	iscsit_cause_connection_reinstatement(conn, sleep);
  	iscsit_dec_conn_usage_count(conn);
  }
  
  static void iscsit_logout_post_handler_diffcid(
  	struct iscsi_conn *conn,
  	u16 cid)
  {
  	struct iscsi_conn *l_conn;
  	struct iscsi_session *sess = conn->sess;
  	bool conn_found = false;
  
  	if (!sess)
  		return;
  
  	spin_lock_bh(&sess->conn_lock);
  	list_for_each_entry(l_conn, &sess->sess_conn_list, conn_list) {
  		if (l_conn->cid == cid) {
  			iscsit_inc_conn_usage_count(l_conn);
  			conn_found = true;
  			break;
  		}
  	}
  	spin_unlock_bh(&sess->conn_lock);
  
  	if (!conn_found)
  		return;
  
  	if (l_conn->sock)
  		l_conn->sock->ops->shutdown(l_conn->sock, RCV_SHUTDOWN);
  
  	spin_lock_bh(&l_conn->state_lock);
  	pr_debug("Moving to TARG_CONN_STATE_IN_LOGOUT.\n");
  	l_conn->conn_state = TARG_CONN_STATE_IN_LOGOUT;
  	spin_unlock_bh(&l_conn->state_lock);
  
  	iscsit_cause_connection_reinstatement(l_conn, 1);
  	iscsit_dec_conn_usage_count(l_conn);
  }
  
  /*
   *	Return of 0 causes the TX thread to restart.
   */
  int iscsit_logout_post_handler(
  	struct iscsi_cmd *cmd,
  	struct iscsi_conn *conn)
  {
  	int ret = 0;
  
  	switch (cmd->logout_reason) {
  	case ISCSI_LOGOUT_REASON_CLOSE_SESSION:
  		switch (cmd->logout_response) {
  		case ISCSI_LOGOUT_SUCCESS:
  		case ISCSI_LOGOUT_CLEANUP_FAILED:
  		default:
  			iscsit_logout_post_handler_closesession(conn);
  			break;
  		}
  		ret = 0;
  		break;
  	case ISCSI_LOGOUT_REASON_CLOSE_CONNECTION:
  		if (conn->cid == cmd->logout_cid) {
  			switch (cmd->logout_response) {
  			case ISCSI_LOGOUT_SUCCESS:
  			case ISCSI_LOGOUT_CLEANUP_FAILED:
  			default:
  				iscsit_logout_post_handler_samecid(conn);
  				break;
  			}
  			ret = 0;
  		} else {
  			switch (cmd->logout_response) {
  			case ISCSI_LOGOUT_SUCCESS:
  				iscsit_logout_post_handler_diffcid(conn,
  					cmd->logout_cid);
  				break;
  			case ISCSI_LOGOUT_CID_NOT_FOUND:
  			case ISCSI_LOGOUT_CLEANUP_FAILED:
  			default:
  				break;
  			}
  			ret = 1;
  		}
  		break;
  	case ISCSI_LOGOUT_REASON_RECOVERY:
  		switch (cmd->logout_response) {
  		case ISCSI_LOGOUT_SUCCESS:
  		case ISCSI_LOGOUT_CID_NOT_FOUND:
  		case ISCSI_LOGOUT_RECOVERY_UNSUPPORTED:
  		case ISCSI_LOGOUT_CLEANUP_FAILED:
  		default:
  			break;
  		}
  		ret = 1;
  		break;
  	default:
  		break;
  
  	}
  	return ret;
  }
  EXPORT_SYMBOL(iscsit_logout_post_handler);
  
  void iscsit_fail_session(struct iscsi_session *sess)
  {
  	struct iscsi_conn *conn;
  
  	spin_lock_bh(&sess->conn_lock);
  	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
  		pr_debug("Moving to TARG_CONN_STATE_CLEANUP_WAIT.\n");
  		conn->conn_state = TARG_CONN_STATE_CLEANUP_WAIT;
  	}
  	spin_unlock_bh(&sess->conn_lock);
  
  	pr_debug("Moving to TARG_SESS_STATE_FAILED.\n");
  	sess->session_state = TARG_SESS_STATE_FAILED;
  }
  
  int iscsit_free_session(struct iscsi_session *sess)
  {
  	u16 conn_count = atomic_read(&sess->nconn);
  	struct iscsi_conn *conn, *conn_tmp = NULL;
  	int is_last;
  
  	spin_lock_bh(&sess->conn_lock);
  	atomic_set(&sess->sleep_on_sess_wait_comp, 1);
  
  	list_for_each_entry_safe(conn, conn_tmp, &sess->sess_conn_list,
  			conn_list) {
  		if (conn_count == 0)
  			break;
  
  		if (list_is_last(&conn->conn_list, &sess->sess_conn_list)) {
  			is_last = 1;
  		} else {
  			iscsit_inc_conn_usage_count(conn_tmp);
  			is_last = 0;
  		}
  		iscsit_inc_conn_usage_count(conn);
  
  		spin_unlock_bh(&sess->conn_lock);
  		iscsit_cause_connection_reinstatement(conn, 1);
  		spin_lock_bh(&sess->conn_lock);
  
  		iscsit_dec_conn_usage_count(conn);
  		if (is_last == 0)
  			iscsit_dec_conn_usage_count(conn_tmp);
  
  		conn_count--;
  	}
  
  	if (atomic_read(&sess->nconn)) {
  		spin_unlock_bh(&sess->conn_lock);
  		wait_for_completion(&sess->session_wait_comp);
  	} else
  		spin_unlock_bh(&sess->conn_lock);
  
  	iscsit_close_session(sess);
  	return 0;
  }
  
  void iscsit_stop_session(
  	struct iscsi_session *sess,
  	int session_sleep,
  	int connection_sleep)
  {
  	u16 conn_count = atomic_read(&sess->nconn);
  	struct iscsi_conn *conn, *conn_tmp = NULL;
  	int is_last;
  
  	spin_lock_bh(&sess->conn_lock);
  	if (session_sleep)
  		atomic_set(&sess->sleep_on_sess_wait_comp, 1);
  
  	if (connection_sleep) {
  		list_for_each_entry_safe(conn, conn_tmp, &sess->sess_conn_list,
  				conn_list) {
  			if (conn_count == 0)
  				break;
  
  			if (list_is_last(&conn->conn_list, &sess->sess_conn_list)) {
  				is_last = 1;
  			} else {
  				iscsit_inc_conn_usage_count(conn_tmp);
  				is_last = 0;
  			}
  			iscsit_inc_conn_usage_count(conn);
  
  			spin_unlock_bh(&sess->conn_lock);
  			iscsit_cause_connection_reinstatement(conn, 1);
  			spin_lock_bh(&sess->conn_lock);
  
  			iscsit_dec_conn_usage_count(conn);
  			if (is_last == 0)
  				iscsit_dec_conn_usage_count(conn_tmp);
  			conn_count--;
  		}
  	} else {
  		list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
  			iscsit_cause_connection_reinstatement(conn, 0);
  	}
  
  	if (session_sleep && atomic_read(&sess->nconn)) {
  		spin_unlock_bh(&sess->conn_lock);
  		wait_for_completion(&sess->session_wait_comp);
  	} else
  		spin_unlock_bh(&sess->conn_lock);
  }
  
  int iscsit_release_sessions_for_tpg(struct iscsi_portal_group *tpg, int force)
  {
  	struct iscsi_session *sess;
  	struct se_portal_group *se_tpg = &tpg->tpg_se_tpg;
  	struct se_session *se_sess, *se_sess_tmp;
  	LIST_HEAD(free_list);
  	int session_count = 0;
  
  	spin_lock_bh(&se_tpg->session_lock);
  	if (tpg->nsessions && !force) {
  		spin_unlock_bh(&se_tpg->session_lock);
  		return -1;
  	}
  
  	list_for_each_entry_safe(se_sess, se_sess_tmp, &se_tpg->tpg_sess_list,
  			sess_list) {
  		sess = (struct iscsi_session *)se_sess->fabric_sess_ptr;
  
  		spin_lock(&sess->conn_lock);
  		if (atomic_read(&sess->session_fall_back_to_erl0) ||
  		    atomic_read(&sess->session_logout) ||
  		    (sess->time2retain_timer_flags & ISCSI_TF_EXPIRED)) {
  			spin_unlock(&sess->conn_lock);
  			continue;
  		}
  		atomic_set(&sess->session_reinstatement, 1);
  		atomic_set(&sess->session_fall_back_to_erl0, 1);
  		spin_unlock(&sess->conn_lock);
  
  		list_move_tail(&se_sess->sess_list, &free_list);
  	}
  	spin_unlock_bh(&se_tpg->session_lock);
  
  	list_for_each_entry_safe(se_sess, se_sess_tmp, &free_list, sess_list) {
  		sess = (struct iscsi_session *)se_sess->fabric_sess_ptr;
  
  		iscsit_free_session(sess);
  		session_count++;
  	}
  
  	pr_debug("Released %d iSCSI Session(s) from Target Portal"
  			" Group: %hu\n", session_count, tpg->tpgt);
  	return 0;
  }
  
  MODULE_DESCRIPTION("iSCSI-Target Driver for mainline target infrastructure");
  MODULE_VERSION("4.1.x");
  MODULE_AUTHOR("nab@Linux-iSCSI.org");
  MODULE_LICENSE("GPL");
  
  module_init(iscsi_target_init_module);
  module_exit(iscsi_target_cleanup_module);
  