iscsi-target: Add iSCSI fabric support for target v4.1

The Linux-iSCSI.org target module is a full featured in-kernel
software implementation of iSCSI target mode (RFC-3720) for the
current WIP mainline target v4.1 infrastructure code for the v3.1
kernel.  More information can be found here:

http://linux-iscsi.org/wiki/ISCSI

This includes support for:

   * RFC-3720 defined request / response state machines and support for
     all defined iSCSI operation codes from Section 10.2.1.2 using libiscsi
     include/scsi/iscsi_proto.h PDU definitions
   * Target v4.1 compatible control plane using the generic layout in
     target_core_fabric_configfs.c and fabric dependent attributes
     within /sys/kernel/config/target/iscsi/ subdirectories.
   * Target v4.1 compatible iSCSI statistics based on RFC-4544 (iSCSI MIBS)
   * Support for IPv6 and IPv4 network portals in M:N mapping to TPGs
   * iSCSI Error Recovery Hierarchy support
   * Per iSCSI connection RX/TX thread pair scheduling affinity
   * crc32c + crc32c_intel SSEv4 instruction offload support using libcrypto
   * CHAP Authentication support using libcrypto
   * Conversion to use internal SGl allocation with iscsit_alloc_buffs() ->
     transport_generic_map_mem_to_cmd()

(nab: Fix iscsi_proto.h struct scsi_lun usage from linux-next in commit:
      iscsi: Use struct scsi_lun in iscsi structs instead of u8[8])
(nab: Fix 32-bit compile warnings)

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andy Grover <agrover@redhat.com>
Acked-by: Roland Dreier <roland@kernel.org>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>

1 files changed, 1819 insertions, 0 deletions

diff --git a/drivers/target/iscsi/iscsi_target_util.c b/drivers/target/iscsi/iscsi_target_util.c
new file mode 100644
index 000000000000..a1acb0167902
--- /dev/null
+++ b/drivers/target/iscsi/iscsi_target_util.c
@@ -0,0 +1,1819 @@
+/*******************************************************************************
+ * This file contains the iSCSI Target specific utility functions.
+ *
+ * \u00a9 Copyright 2007-2011 RisingTide Systems LLC.
+ *
+ * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
+ *
+ * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ ******************************************************************************/
+
+#include <linux/list.h>
+#include <scsi/scsi_tcq.h>
+#include <scsi/iscsi_proto.h>
+#include <target/target_core_base.h>
+#include <target/target_core_transport.h>
+#include <target/target_core_tmr.h>
+#include <target/target_core_fabric_ops.h>
+#include <target/target_core_configfs.h>
+
+#include "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_tpg.h"
+#include "iscsi_target_tq.h"
+#include "iscsi_target_util.h"
+#include "iscsi_target.h"
+
+#define PRINT_BUFF(buff, len)					\
+{								\
+	int zzz;						\
+								\
+	pr_debug("%d:\n", __LINE__);				\
+	for (zzz = 0; zzz < len; zzz++) {			\
+		if (zzz % 16 == 0) {				\
+			if (zzz)				\
+				pr_debug("\n");			\
+			pr_debug("%4i: ", zzz);			\
+		}						\
+		pr_debug("%02x ", (unsigned char) (buff)[zzz]);	\
+	}							\
+	if ((len + 1) % 16)					\
+		pr_debug("\n");					\
+}
+
+extern struct list_head g_tiqn_list;
+extern spinlock_t tiqn_lock;
+
+/*
+ *	Called with cmd->r2t_lock held.
+ */
+int iscsit_add_r2t_to_list(
+	struct iscsi_cmd *cmd,
+	u32 offset,
+	u32 xfer_len,
+	int recovery,
+	u32 r2t_sn)
+{
+	struct iscsi_r2t *r2t;
+
+	r2t = kmem_cache_zalloc(lio_r2t_cache, GFP_ATOMIC);
+	if (!r2t) {
+		pr_err("Unable to allocate memory for struct iscsi_r2t.\n");
+		return -1;
+	}
+	INIT_LIST_HEAD(&r2t->r2t_list);
+
+	r2t->recovery_r2t = recovery;
+	r2t->r2t_sn = (!r2t_sn) ? cmd->r2t_sn++ : r2t_sn;
+	r2t->offset = offset;
+	r2t->xfer_len = xfer_len;
+	list_add_tail(&r2t->r2t_list, &cmd->cmd_r2t_list);
+	spin_unlock_bh(&cmd->r2t_lock);
+
+	iscsit_add_cmd_to_immediate_queue(cmd, cmd->conn, ISTATE_SEND_R2T);
+
+	spin_lock_bh(&cmd->r2t_lock);
+	return 0;
+}
+
+struct iscsi_r2t *iscsit_get_r2t_for_eos(
+	struct iscsi_cmd *cmd,
+	u32 offset,
+	u32 length)
+{
+	struct iscsi_r2t *r2t;
+
+	spin_lock_bh(&cmd->r2t_lock);
+	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
+		if ((r2t->offset <= offset) &&
+		    (r2t->offset + r2t->xfer_len) >= (offset + length)) {
+			spin_unlock_bh(&cmd->r2t_lock);
+			return r2t;
+		}
+	}
+	spin_unlock_bh(&cmd->r2t_lock);
+
+	pr_err("Unable to locate R2T for Offset: %u, Length:"
+			" %u\n", offset, length);
+	return NULL;
+}
+
+struct iscsi_r2t *iscsit_get_r2t_from_list(struct iscsi_cmd *cmd)
+{
+	struct iscsi_r2t *r2t;
+
+	spin_lock_bh(&cmd->r2t_lock);
+	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
+		if (!r2t->sent_r2t) {
+			spin_unlock_bh(&cmd->r2t_lock);
+			return r2t;
+		}
+	}
+	spin_unlock_bh(&cmd->r2t_lock);
+
+	pr_err("Unable to locate next R2T to send for ITT:"
+			" 0x%08x.\n", cmd->init_task_tag);
+	return NULL;
+}
+
+/*
+ *	Called with cmd->r2t_lock held.
+ */
+void iscsit_free_r2t(struct iscsi_r2t *r2t, struct iscsi_cmd *cmd)
+{
+	list_del(&r2t->r2t_list);
+	kmem_cache_free(lio_r2t_cache, r2t);
+}
+
+void iscsit_free_r2ts_from_list(struct iscsi_cmd *cmd)
+{
+	struct iscsi_r2t *r2t, *r2t_tmp;
+
+	spin_lock_bh(&cmd->r2t_lock);
+	list_for_each_entry_safe(r2t, r2t_tmp, &cmd->cmd_r2t_list, r2t_list)
+		iscsit_free_r2t(r2t, cmd);
+	spin_unlock_bh(&cmd->r2t_lock);
+}
+
+/*
+ * May be called from software interrupt (timer) context for allocating
+ * iSCSI NopINs.
+ */
+struct iscsi_cmd *iscsit_allocate_cmd(struct iscsi_conn *conn, gfp_t gfp_mask)
+{
+	struct iscsi_cmd *cmd;
+
+	cmd = kmem_cache_zalloc(lio_cmd_cache, gfp_mask);
+	if (!cmd) {
+		pr_err("Unable to allocate memory for struct iscsi_cmd.\n");
+		return NULL;
+	}
+
+	cmd->conn	= conn;
+	INIT_LIST_HEAD(&cmd->i_list);
+	INIT_LIST_HEAD(&cmd->datain_list);
+	INIT_LIST_HEAD(&cmd->cmd_r2t_list);
+	init_completion(&cmd->reject_comp);
+	spin_lock_init(&cmd->datain_lock);
+	spin_lock_init(&cmd->dataout_timeout_lock);
+	spin_lock_init(&cmd->istate_lock);
+	spin_lock_init(&cmd->error_lock);
+	spin_lock_init(&cmd->r2t_lock);
+
+	return cmd;
+}
+
+/*
+ * Called from iscsi_handle_scsi_cmd()
+ */
+struct iscsi_cmd *iscsit_allocate_se_cmd(
+	struct iscsi_conn *conn,
+	u32 data_length,
+	int data_direction,
+	int iscsi_task_attr)
+{
+	struct iscsi_cmd *cmd;
+	struct se_cmd *se_cmd;
+	int sam_task_attr;
+
+	cmd = iscsit_allocate_cmd(conn, GFP_KERNEL);
+	if (!cmd)
+		return NULL;
+
+	cmd->data_direction = data_direction;
+	cmd->data_length = data_length;
+	/*
+	 * 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 = MSG_SIMPLE_TAG;
+	else if (iscsi_task_attr == ISCSI_ATTR_ORDERED)
+		sam_task_attr = MSG_ORDERED_TAG;
+	else if (iscsi_task_attr == ISCSI_ATTR_HEAD_OF_QUEUE)
+		sam_task_attr = MSG_HEAD_TAG;
+	else if (iscsi_task_attr == ISCSI_ATTR_ACA)
+		sam_task_attr = MSG_ACA_TAG;
+	else {
+		pr_debug("Unknown iSCSI Task Attribute: 0x%02x, using"
+			" MSG_SIMPLE_TAG\n", iscsi_task_attr);
+		sam_task_attr = MSG_SIMPLE_TAG;
+	}
+
+	se_cmd = &cmd->se_cmd;
+	/*
+	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
+	 */
+	transport_init_se_cmd(se_cmd, &lio_target_fabric_configfs->tf_ops,
+			conn->sess->se_sess, data_length, data_direction,
+			sam_task_attr, &cmd->sense_buffer[0]);
+	return cmd;
+}
+
+struct iscsi_cmd *iscsit_allocate_se_cmd_for_tmr(
+	struct iscsi_conn *conn,
+	u8 function)
+{
+	struct iscsi_cmd *cmd;
+	struct se_cmd *se_cmd;
+	u8 tcm_function;
+
+	cmd = iscsit_allocate_cmd(conn, GFP_KERNEL);
+	if (!cmd)
+		return NULL;
+
+	cmd->data_direction = DMA_NONE;
+
+	cmd->tmr_req = kzalloc(sizeof(struct iscsi_tmr_req), GFP_KERNEL);
+	if (!cmd->tmr_req) {
+		pr_err("Unable to allocate memory for"
+			" Task Management command!\n");
+		return NULL;
+	}
+	/*
+	 * TASK_REASSIGN for ERL=2 / connection stays inside of
+	 * LIO-Target $FABRIC_MOD
+	 */
+	if (function == ISCSI_TM_FUNC_TASK_REASSIGN)
+		return cmd;
+
+	se_cmd = &cmd->se_cmd;
+	/*
+	 * Initialize struct se_cmd descriptor from target_core_mod infrastructure
+	 */
+	transport_init_se_cmd(se_cmd, &lio_target_fabric_configfs->tf_ops,
+				conn->sess->se_sess, 0, DMA_NONE,
+				MSG_SIMPLE_TAG, &cmd->sense_buffer[0]);
+
+	switch (function) {
+	case ISCSI_TM_FUNC_ABORT_TASK:
+		tcm_function = TMR_ABORT_TASK;
+		break;
+	case ISCSI_TM_FUNC_ABORT_TASK_SET:
+		tcm_function = TMR_ABORT_TASK_SET;
+		break;
+	case ISCSI_TM_FUNC_CLEAR_ACA:
+		tcm_function = TMR_CLEAR_ACA;
+		break;
+	case ISCSI_TM_FUNC_CLEAR_TASK_SET:
+		tcm_function = TMR_CLEAR_TASK_SET;
+		break;
+	case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
+		tcm_function = TMR_LUN_RESET;
+		break;
+	case ISCSI_TM_FUNC_TARGET_WARM_RESET:
+		tcm_function = TMR_TARGET_WARM_RESET;
+		break;
+	case ISCSI_TM_FUNC_TARGET_COLD_RESET:
+		tcm_function = TMR_TARGET_COLD_RESET;
+		break;
+	default:
+		pr_err("Unknown iSCSI TMR Function:"
+			" 0x%02x\n", function);
+		goto out;
+	}
+
+	se_cmd->se_tmr_req = core_tmr_alloc_req(se_cmd,
+				(void *)cmd->tmr_req, tcm_function);
+	if (!se_cmd->se_tmr_req)
+		goto out;
+
+	cmd->tmr_req->se_tmr_req = se_cmd->se_tmr_req;
+
+	return cmd;
+out:
+	iscsit_release_cmd(cmd);
+	if (se_cmd)
+		transport_free_se_cmd(se_cmd);
+	return NULL;
+}
+
+int iscsit_decide_list_to_build(
+	struct iscsi_cmd *cmd,
+	u32 immediate_data_length)
+{
+	struct iscsi_build_list bl;
+	struct iscsi_conn *conn = cmd->conn;
+	struct iscsi_session *sess = conn->sess;
+	struct iscsi_node_attrib *na;
+
+	if (sess->sess_ops->DataSequenceInOrder &&
+	    sess->sess_ops->DataPDUInOrder)
+		return 0;
+
+	if (cmd->data_direction == DMA_NONE)
+		return 0;
+
+	na = iscsit_tpg_get_node_attrib(sess);
+	memset(&bl, 0, sizeof(struct iscsi_build_list));
+
+	if (cmd->data_direction == DMA_FROM_DEVICE) {
+		bl.data_direction = ISCSI_PDU_READ;
+		bl.type = PDULIST_NORMAL;
+		if (na->random_datain_pdu_offsets)
+			bl.randomize |= RANDOM_DATAIN_PDU_OFFSETS;
+		if (na->random_datain_seq_offsets)
+			bl.randomize |= RANDOM_DATAIN_SEQ_OFFSETS;
+	} else {
+		bl.data_direction = ISCSI_PDU_WRITE;
+		bl.immediate_data_length = immediate_data_length;
+		if (na->random_r2t_offsets)
+			bl.randomize |= RANDOM_R2T_OFFSETS;
+
+		if (!cmd->immediate_data && !cmd->unsolicited_data)
+			bl.type = PDULIST_NORMAL;
+		else if (cmd->immediate_data && !cmd->unsolicited_data)
+			bl.type = PDULIST_IMMEDIATE;
+		else if (!cmd->immediate_data && cmd->unsolicited_data)
+			bl.type = PDULIST_UNSOLICITED;
+		else if (cmd->immediate_data && cmd->unsolicited_data)
+			bl.type = PDULIST_IMMEDIATE_AND_UNSOLICITED;
+	}
+
+	return iscsit_do_build_list(cmd, &bl);
+}
+
+struct iscsi_seq *iscsit_get_seq_holder_for_datain(
+	struct iscsi_cmd *cmd,
+	u32 seq_send_order)
+{
+	u32 i;
+
+	for (i = 0; i < cmd->seq_count; i++)
+		if (cmd->seq_list[i].seq_send_order == seq_send_order)
+			return &cmd->seq_list[i];
+
+	return NULL;
+}
+
+struct iscsi_seq *iscsit_get_seq_holder_for_r2t(struct iscsi_cmd *cmd)
+{
+	u32 i;
+
+	if (!cmd->seq_list) {
+		pr_err("struct iscsi_cmd->seq_list is NULL!\n");
+		return NULL;
+	}
+
+	for (i = 0; i < cmd->seq_count; i++) {
+		if (cmd->seq_list[i].type != SEQTYPE_NORMAL)
+			continue;
+		if (cmd->seq_list[i].seq_send_order == cmd->seq_send_order) {
+			cmd->seq_send_order++;
+			return &cmd->seq_list[i];
+		}
+	}
+
+	return NULL;
+}
+
+struct iscsi_r2t *iscsit_get_holder_for_r2tsn(
+	struct iscsi_cmd *cmd,
+	u32 r2t_sn)
+{
+	struct iscsi_r2t *r2t;
+
+	spin_lock_bh(&cmd->r2t_lock);
+	list_for_each_entry(r2t, &cmd->cmd_r2t_list, r2t_list) {
+		if (r2t->r2t_sn == r2t_sn) {
+			spin_unlock_bh(&cmd->r2t_lock);
+			return r2t;
+		}
+	}
+	spin_unlock_bh(&cmd->r2t_lock);
+
+	return NULL;
+}
+
+static inline int iscsit_check_received_cmdsn(struct iscsi_session *sess, u32 cmdsn)
+{
+	int ret;
+
+	/*
+	 * This is the proper method of checking received CmdSN against
+	 * ExpCmdSN and MaxCmdSN values, as well as accounting for out
+	 * or order CmdSNs due to multiple connection sessions and/or
+	 * CRC failures.
+	 */
+	if (iscsi_sna_gt(cmdsn, sess->max_cmd_sn)) {
+		pr_err("Received CmdSN: 0x%08x is greater than"
+		       " MaxCmdSN: 0x%08x, protocol error.\n", cmdsn,
+		       sess->max_cmd_sn);
+		ret = CMDSN_ERROR_CANNOT_RECOVER;
+
+	} else if (cmdsn == sess->exp_cmd_sn) {
+		sess->exp_cmd_sn++;
+		pr_debug("Received CmdSN matches ExpCmdSN,"
+		      " incremented ExpCmdSN to: 0x%08x\n",
+		      sess->exp_cmd_sn);
+		ret = CMDSN_NORMAL_OPERATION;
+
+	} else if (iscsi_sna_gt(cmdsn, sess->exp_cmd_sn)) {
+		pr_debug("Received CmdSN: 0x%08x is greater"
+		      " than ExpCmdSN: 0x%08x, not acknowledging.\n",
+		      cmdsn, sess->exp_cmd_sn);
+		ret = CMDSN_HIGHER_THAN_EXP;
+
+	} else {
+		pr_err("Received CmdSN: 0x%08x is less than"
+		       " ExpCmdSN: 0x%08x, ignoring.\n", cmdsn,
+		       sess->exp_cmd_sn);
+		ret = CMDSN_LOWER_THAN_EXP;
+	}
+
+	return ret;
+}
+
+/*
+ * Commands may be received out of order if MC/S is in use.
+ * Ensure they are executed in CmdSN order.
+ */
+int iscsit_sequence_cmd(
+	struct iscsi_conn *conn,
+	struct iscsi_cmd *cmd,
+	u32 cmdsn)
+{
+	int ret;
+	int cmdsn_ret;
+
+	mutex_lock(&conn->sess->cmdsn_mutex);
+
+	cmdsn_ret = iscsit_check_received_cmdsn(conn->sess, cmdsn);
+	switch (cmdsn_ret) {
+	case CMDSN_NORMAL_OPERATION:
+		ret = iscsit_execute_cmd(cmd, 0);
+		if ((ret >= 0) && !list_empty(&conn->sess->sess_ooo_cmdsn_list))
+			iscsit_execute_ooo_cmdsns(conn->sess);
+		break;
+	case CMDSN_HIGHER_THAN_EXP:
+		ret = iscsit_handle_ooo_cmdsn(conn->sess, cmd, cmdsn);
+		break;
+	case CMDSN_LOWER_THAN_EXP:
+		cmd->i_state = ISTATE_REMOVE;
+		iscsit_add_cmd_to_immediate_queue(cmd, conn, cmd->i_state);
+		ret = cmdsn_ret;
+		break;
+	default:
+		ret = cmdsn_ret;
+		break;
+	}
+	mutex_unlock(&conn->sess->cmdsn_mutex);
+
+	return ret;
+}
+
+int iscsit_check_unsolicited_dataout(struct iscsi_cmd *cmd, unsigned char *buf)
+{
+	struct iscsi_conn *conn = cmd->conn;
+	struct se_cmd *se_cmd = &cmd->se_cmd;
+	struct iscsi_data *hdr = (struct iscsi_data *) buf;
+	u32 payload_length = ntoh24(hdr->dlength);
+
+	if (conn->sess->sess_ops->InitialR2T) {
+		pr_err("Received unexpected unsolicited data"
+			" while InitialR2T=Yes, protocol error.\n");
+		transport_send_check_condition_and_sense(se_cmd,
+				TCM_UNEXPECTED_UNSOLICITED_DATA, 0);
+		return -1;
+	}
+
+	if ((cmd->first_burst_len + payload_length) >
+	     conn->sess->sess_ops->FirstBurstLength) {
+		pr_err("Total %u bytes exceeds FirstBurstLength: %u"
+			" for this Unsolicited DataOut Burst.\n",
+			(cmd->first_burst_len + payload_length),
+				conn->sess->sess_ops->FirstBurstLength);
+		transport_send_check_condition_and_sense(se_cmd,
+				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
+		return -1;
+	}
+
+	if (!(hdr->flags & ISCSI_FLAG_CMD_FINAL))
+		return 0;
+
+	if (((cmd->first_burst_len + payload_length) != cmd->data_length) &&
+	    ((cmd->first_burst_len + payload_length) !=
+	      conn->sess->sess_ops->FirstBurstLength)) {
+		pr_err("Unsolicited non-immediate data received %u"
+			" does not equal FirstBurstLength: %u, and does"
+			" not equal ExpXferLen %u.\n",
+			(cmd->first_burst_len + payload_length),
+			conn->sess->sess_ops->FirstBurstLength, cmd->data_length);
+		transport_send_check_condition_and_sense(se_cmd,
+				TCM_INCORRECT_AMOUNT_OF_DATA, 0);
+		return -1;
+	}
+	return 0;
+}
+
+struct iscsi_cmd *iscsit_find_cmd_from_itt(
+	struct iscsi_conn *conn,
+	u32 init_task_tag)
+{
+	struct iscsi_cmd *cmd;
+
+	spin_lock_bh(&conn->cmd_lock);
+	list_for_each_entry(cmd, &conn->conn_cmd_list, i_list) {
+		if (cmd->init_task_tag == init_task_tag) {
+			spin_unlock_bh(&conn->cmd_lock);
+			return cmd;
+		}
+	}
+	spin_unlock_bh(&conn->cmd_lock);
+
+	pr_err("Unable to locate ITT: 0x%08x on CID: %hu",
+			init_task_tag, conn->cid);
+	return NULL;
+}
+
+struct iscsi_cmd *iscsit_find_cmd_from_itt_or_dump(
+	struct iscsi_conn *conn,
+	u32 init_task_tag,
+	u32 length)
+{
+	struct iscsi_cmd *cmd;
+
+	spin_lock_bh(&conn->cmd_lock);
+	list_for_each_entry(cmd, &conn->conn_cmd_list, i_list) {
+		if (cmd->init_task_tag == init_task_tag) {
+			spin_unlock_bh(&conn->cmd_lock);
+			return cmd;
+		}
+	}
+	spin_unlock_bh(&conn->cmd_lock);
+
+	pr_err("Unable to locate ITT: 0x%08x on CID: %hu,"
+			" dumping payload\n", init_task_tag, conn->cid);
+	if (length)
+		iscsit_dump_data_payload(conn, length, 1);
+
+	return NULL;
+}
+
+struct iscsi_cmd *iscsit_find_cmd_from_ttt(
+	struct iscsi_conn *conn,
+	u32 targ_xfer_tag)
+{
+	struct iscsi_cmd *cmd = NULL;
+
+	spin_lock_bh(&conn->cmd_lock);
+	list_for_each_entry(cmd, &conn->conn_cmd_list, i_list) {
+		if (cmd->targ_xfer_tag == targ_xfer_tag) {
+			spin_unlock_bh(&conn->cmd_lock);
+			return cmd;
+		}
+	}
+	spin_unlock_bh(&conn->cmd_lock);
+
+	pr_err("Unable to locate TTT: 0x%08x on CID: %hu\n",
+			targ_xfer_tag, conn->cid);
+	return NULL;
+}
+
+int iscsit_find_cmd_for_recovery(
+	struct iscsi_session *sess,
+	struct iscsi_cmd **cmd_ptr,
+	struct iscsi_conn_recovery **cr_ptr,
+	u32 init_task_tag)
+{
+	struct iscsi_cmd *cmd = NULL;
+	struct iscsi_conn_recovery *cr;
+	/*
+	 * Scan through the inactive connection recovery list's command list.
+	 * If init_task_tag matches the command is still alligent.
+	 */
+	spin_lock(&sess->cr_i_lock);
+	list_for_each_entry(cr, &sess->cr_inactive_list, cr_list) {
+		spin_lock(&cr->conn_recovery_cmd_lock);
+		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_list) {
+			if (cmd->init_task_tag == init_task_tag) {
+				spin_unlock(&cr->conn_recovery_cmd_lock);
+				spin_unlock(&sess->cr_i_lock);
+
+				*cr_ptr = cr;
+				*cmd_ptr = cmd;
+				return -2;
+			}
+		}
+		spin_unlock(&cr->conn_recovery_cmd_lock);
+	}
+	spin_unlock(&sess->cr_i_lock);
+	/*
+	 * Scan through the active connection recovery list's command list.
+	 * If init_task_tag matches the command is ready to be reassigned.
+	 */
+	spin_lock(&sess->cr_a_lock);
+	list_for_each_entry(cr, &sess->cr_active_list, cr_list) {
+		spin_lock(&cr->conn_recovery_cmd_lock);
+		list_for_each_entry(cmd, &cr->conn_recovery_cmd_list, i_list) {
+			if (cmd->init_task_tag == init_task_tag) {
+				spin_unlock(&cr->conn_recovery_cmd_lock);
+				spin_unlock(&sess->cr_a_lock);
+
+				*cr_ptr = cr;
+				*cmd_ptr = cmd;
+				return 0;
+			}
+		}
+		spin_unlock(&cr->conn_recovery_cmd_lock);
+	}
+	spin_unlock(&sess->cr_a_lock);
+
+	return -1;
+}
+
+void iscsit_add_cmd_to_immediate_queue(
+	struct iscsi_cmd *cmd,
+	struct iscsi_conn *conn,
+	u8 state)
+{
+	struct iscsi_queue_req *qr;
+
+	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
+	if (!qr) {
+		pr_err("Unable to allocate memory for"
+				" struct iscsi_queue_req\n");
+		return;
+	}
+	INIT_LIST_HEAD(&qr->qr_list);
+	qr->cmd = cmd;
+	qr->state = state;
+
+	spin_lock_bh(&conn->immed_queue_lock);
+	list_add_tail(&qr->qr_list, &conn->immed_queue_list);
+	atomic_inc(&cmd->immed_queue_count);
+	atomic_set(&conn->check_immediate_queue, 1);
+	spin_unlock_bh(&conn->immed_queue_lock);
+
+	wake_up_process(conn->thread_set->tx_thread);
+}
+
+struct iscsi_queue_req *iscsit_get_cmd_from_immediate_queue(struct iscsi_conn *conn)
+{
+	struct iscsi_queue_req *qr;
+
+	spin_lock_bh(&conn->immed_queue_lock);
+	if (list_empty(&conn->immed_queue_list)) {
+		spin_unlock_bh(&conn->immed_queue_lock);
+		return NULL;
+	}
+	list_for_each_entry(qr, &conn->immed_queue_list, qr_list)
+		break;
+
+	list_del(&qr->qr_list);
+	if (qr->cmd)
+		atomic_dec(&qr->cmd->immed_queue_count);
+	spin_unlock_bh(&conn->immed_queue_lock);
+
+	return qr;
+}
+
+static void iscsit_remove_cmd_from_immediate_queue(
+	struct iscsi_cmd *cmd,
+	struct iscsi_conn *conn)
+{
+	struct iscsi_queue_req *qr, *qr_tmp;
+
+	spin_lock_bh(&conn->immed_queue_lock);
+	if (!atomic_read(&cmd->immed_queue_count)) {
+		spin_unlock_bh(&conn->immed_queue_lock);
+		return;
+	}
+
+	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
+		if (qr->cmd != cmd)
+			continue;
+
+		atomic_dec(&qr->cmd->immed_queue_count);
+		list_del(&qr->qr_list);
+		kmem_cache_free(lio_qr_cache, qr);
+	}
+	spin_unlock_bh(&conn->immed_queue_lock);
+
+	if (atomic_read(&cmd->immed_queue_count)) {
+		pr_err("ITT: 0x%08x immed_queue_count: %d\n",
+			cmd->init_task_tag,
+			atomic_read(&cmd->immed_queue_count));
+	}
+}
+
+void iscsit_add_cmd_to_response_queue(
+	struct iscsi_cmd *cmd,
+	struct iscsi_conn *conn,
+	u8 state)
+{
+	struct iscsi_queue_req *qr;
+
+	qr = kmem_cache_zalloc(lio_qr_cache, GFP_ATOMIC);
+	if (!qr) {
+		pr_err("Unable to allocate memory for"
+			" struct iscsi_queue_req\n");
+		return;
+	}
+	INIT_LIST_HEAD(&qr->qr_list);
+	qr->cmd = cmd;
+	qr->state = state;
+
+	spin_lock_bh(&conn->response_queue_lock);
+	list_add_tail(&qr->qr_list, &conn->response_queue_list);
+	atomic_inc(&cmd->response_queue_count);
+	spin_unlock_bh(&conn->response_queue_lock);
+
+	wake_up_process(conn->thread_set->tx_thread);
+}
+
+struct iscsi_queue_req *iscsit_get_cmd_from_response_queue(struct iscsi_conn *conn)
+{
+	struct iscsi_queue_req *qr;
+
+	spin_lock_bh(&conn->response_queue_lock);
+	if (list_empty(&conn->response_queue_list)) {
+		spin_unlock_bh(&conn->response_queue_lock);
+		return NULL;
+	}
+
+	list_for_each_entry(qr, &conn->response_queue_list, qr_list)
+		break;
+
+	list_del(&qr->qr_list);
+	if (qr->cmd)
+		atomic_dec(&qr->cmd->response_queue_count);
+	spin_unlock_bh(&conn->response_queue_lock);
+
+	return qr;
+}
+
+static void iscsit_remove_cmd_from_response_queue(
+	struct iscsi_cmd *cmd,
+	struct iscsi_conn *conn)
+{
+	struct iscsi_queue_req *qr, *qr_tmp;
+
+	spin_lock_bh(&conn->response_queue_lock);
+	if (!atomic_read(&cmd->response_queue_count)) {
+		spin_unlock_bh(&conn->response_queue_lock);
+		return;
+	}
+
+	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
+				qr_list) {
+		if (qr->cmd != cmd)
+			continue;
+
+		atomic_dec(&qr->cmd->response_queue_count);
+		list_del(&qr->qr_list);
+		kmem_cache_free(lio_qr_cache, qr);
+	}
+	spin_unlock_bh(&conn->response_queue_lock);
+
+	if (atomic_read(&cmd->response_queue_count)) {
+		pr_err("ITT: 0x%08x response_queue_count: %d\n",
+			cmd->init_task_tag,
+			atomic_read(&cmd->response_queue_count));
+	}
+}
+
+void iscsit_free_queue_reqs_for_conn(struct iscsi_conn *conn)
+{
+	struct iscsi_queue_req *qr, *qr_tmp;
+
+	spin_lock_bh(&conn->immed_queue_lock);
+	list_for_each_entry_safe(qr, qr_tmp, &conn->immed_queue_list, qr_list) {
+		list_del(&qr->qr_list);
+		if (qr->cmd)
+			atomic_dec(&qr->cmd->immed_queue_count);
+
+		kmem_cache_free(lio_qr_cache, qr);
+	}
+	spin_unlock_bh(&conn->immed_queue_lock);
+
+	spin_lock_bh(&conn->response_queue_lock);
+	list_for_each_entry_safe(qr, qr_tmp, &conn->response_queue_list,
+			qr_list) {
+		list_del(&qr->qr_list);
+		if (qr->cmd)
+			atomic_dec(&qr->cmd->response_queue_count);
+
+		kmem_cache_free(lio_qr_cache, qr);
+	}
+	spin_unlock_bh(&conn->response_queue_lock);
+}
+
+void iscsit_release_cmd(struct iscsi_cmd *cmd)
+{
+	struct iscsi_conn *conn = cmd->conn;
+	int i;
+
+	iscsit_free_r2ts_from_list(cmd);
+	iscsit_free_all_datain_reqs(cmd);
+
+	kfree(cmd->buf_ptr);
+	kfree(cmd->pdu_list);
+	kfree(cmd->seq_list);
+	kfree(cmd->tmr_req);
+	kfree(cmd->iov_data);
+
+	for (i = 0; i < cmd->t_mem_sg_nents; i++)
+		__free_page(sg_page(&cmd->t_mem_sg[i]));
+
+	kfree(cmd->t_mem_sg);
+
+	if (conn) {
+		iscsit_remove_cmd_from_immediate_queue(cmd, conn);
+		iscsit_remove_cmd_from_response_queue(cmd, conn);
+	}
+
+	kmem_cache_free(lio_cmd_cache, cmd);
+}
+
+int iscsit_check_session_usage_count(struct iscsi_session *sess)
+{
+	spin_lock_bh(&sess->session_usage_lock);
+	if (sess->session_usage_count != 0) {
+		sess->session_waiting_on_uc = 1;
+		spin_unlock_bh(&sess->session_usage_lock);
+		if (in_interrupt())
+			return 2;
+
+		wait_for_completion(&sess->session_waiting_on_uc_comp);
+		return 1;
+	}
+	spin_unlock_bh(&sess->session_usage_lock);
+
+	return 0;
+}
+
+void iscsit_dec_session_usage_count(struct iscsi_session *sess)
+{
+	spin_lock_bh(&sess->session_usage_lock);
+	sess->session_usage_count--;
+
+	if (!sess->session_usage_count && sess->session_waiting_on_uc)
+		complete(&sess->session_waiting_on_uc_comp);
+
+	spin_unlock_bh(&sess->session_usage_lock);
+}
+
+void iscsit_inc_session_usage_count(struct iscsi_session *sess)
+{
+	spin_lock_bh(&sess->session_usage_lock);
+	sess->session_usage_count++;
+	spin_unlock_bh(&sess->session_usage_lock);
+}
+
+/*
+ *	Used before iscsi_do[rx,tx]_data() to determine iov and [rx,tx]_marker
+ *	array counts needed for sync and steering.
+ */
+static int iscsit_determine_sync_and_steering_counts(
+	struct iscsi_conn *conn,
+	struct iscsi_data_count *count)
+{
+	u32 length = count->data_length;
+	u32 marker, markint;
+
+	count->sync_and_steering = 1;
+
+	marker = (count->type == ISCSI_RX_DATA) ?
+			conn->of_marker : conn->if_marker;
+	markint = (count->type == ISCSI_RX_DATA) ?
+			(conn->conn_ops->OFMarkInt * 4) :
+			(conn->conn_ops->IFMarkInt * 4);
+	count->ss_iov_count = count->iov_count;
+
+	while (length > 0) {
+		if (length >= marker) {
+			count->ss_iov_count += 3;
+			count->ss_marker_count += 2;
+
+			length -= marker;
+			marker = markint;
+		} else
+			length = 0;
+	}
+
+	return 0;
+}
+
+/*
+ *	Setup conn->if_marker and conn->of_marker values based upon
+ *	the initial marker-less interval. (see iSCSI v19 A.2)
+ */
+int iscsit_set_sync_and_steering_values(struct iscsi_conn *conn)
+{
+	int login_ifmarker_count = 0, login_ofmarker_count = 0, next_marker = 0;
+	/*
+	 * IFMarkInt and OFMarkInt are negotiated as 32-bit words.
+	 */
+	u32 IFMarkInt = (conn->conn_ops->IFMarkInt * 4);
+	u32 OFMarkInt = (conn->conn_ops->OFMarkInt * 4);
+
+	if (conn->conn_ops->OFMarker) {
+		/*
+		 * Account for the first Login Command received not
+		 * via iscsi_recv_msg().
+		 */
+		conn->of_marker += ISCSI_HDR_LEN;
+		if (conn->of_marker <= OFMarkInt) {
+			conn->of_marker = (OFMarkInt - conn->of_marker);
+		} else {
+			login_ofmarker_count = (conn->of_marker / OFMarkInt);
+			next_marker = (OFMarkInt * (login_ofmarker_count + 1)) +
+					(login_ofmarker_count * MARKER_SIZE);
+			conn->of_marker = (next_marker - conn->of_marker);
+		}
+		conn->of_marker_offset = 0;
+		pr_debug("Setting OFMarker value to %u based on Initial"
+			" Markerless Interval.\n", conn->of_marker);
+	}
+
+	if (conn->conn_ops->IFMarker) {
+		if (conn->if_marker <= IFMarkInt) {
+			conn->if_marker = (IFMarkInt - conn->if_marker);
+		} else {
+			login_ifmarker_count = (conn->if_marker / IFMarkInt);
+			next_marker = (IFMarkInt * (login_ifmarker_count + 1)) +
+					(login_ifmarker_count * MARKER_SIZE);
+			conn->if_marker = (next_marker - conn->if_marker);
+		}
+		pr_debug("Setting IFMarker value to %u based on Initial"
+			" Markerless Interval.\n", conn->if_marker);
+	}
+
+	return 0;
+}
+
+struct iscsi_conn *iscsit_get_conn_from_cid(struct iscsi_session *sess, u16 cid)
+{
+	struct iscsi_conn *conn;
+
+	spin_lock_bh(&sess->conn_lock);
+	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
+		if ((conn->cid == cid) &&
+		    (conn->conn_state == TARG_CONN_STATE_LOGGED_IN)) {
+			iscsit_inc_conn_usage_count(conn);
+			spin_unlock_bh(&sess->conn_lock);
+			return conn;
+		}
+	}
+	spin_unlock_bh(&sess->conn_lock);
+
+	return NULL;
+}
+
+struct iscsi_conn *iscsit_get_conn_from_cid_rcfr(struct iscsi_session *sess, u16 cid)
+{
+	struct iscsi_conn *conn;
+
+	spin_lock_bh(&sess->conn_lock);
+	list_for_each_entry(conn, &sess->sess_conn_list, conn_list) {
+		if (conn->cid == cid) {
+			iscsit_inc_conn_usage_count(conn);
+			spin_lock(&conn->state_lock);
+			atomic_set(&conn->connection_wait_rcfr, 1);
+			spin_unlock(&conn->state_lock);
+			spin_unlock_bh(&sess->conn_lock);
+			return conn;
+		}
+	}
+	spin_unlock_bh(&sess->conn_lock);
+
+	return NULL;
+}
+
+void iscsit_check_conn_usage_count(struct iscsi_conn *conn)
+{
+	spin_lock_bh(&conn->conn_usage_lock);
+	if (conn->conn_usage_count != 0) {
+		conn->conn_waiting_on_uc = 1;
+		spin_unlock_bh(&conn->conn_usage_lock);
+
+		wait_for_completion(&conn->conn_waiting_on_uc_comp);
+		return;
+	}
+	spin_unlock_bh(&conn->conn_usage_lock);
+}
+
+void iscsit_dec_conn_usage_count(struct iscsi_conn *conn)
+{
+	spin_lock_bh(&conn->conn_usage_lock);
+	conn->conn_usage_count--;
+
+	if (!conn->conn_usage_count && conn->conn_waiting_on_uc)
+		complete(&conn->conn_waiting_on_uc_comp);
+
+	spin_unlock_bh(&conn->conn_usage_lock);
+}
+
+void iscsit_inc_conn_usage_count(struct iscsi_conn *conn)
+{
+	spin_lock_bh(&conn->conn_usage_lock);
+	conn->conn_usage_count++;
+	spin_unlock_bh(&conn->conn_usage_lock);
+}
+
+static int iscsit_add_nopin(struct iscsi_conn *conn, int want_response)
+{
+	u8 state;
+	struct iscsi_cmd *cmd;
+
+	cmd = iscsit_allocate_cmd(conn, GFP_ATOMIC);
+	if (!cmd)
+		return -1;
+
+	cmd->iscsi_opcode = ISCSI_OP_NOOP_IN;
+	state = (want_response) ? ISTATE_SEND_NOPIN_WANT_RESPONSE :
+				ISTATE_SEND_NOPIN_NO_RESPONSE;
+	cmd->init_task_tag = 0xFFFFFFFF;
+	spin_lock_bh(&conn->sess->ttt_lock);
+	cmd->targ_xfer_tag = (want_response) ? conn->sess->targ_xfer_tag++ :
+			0xFFFFFFFF;
+	if (want_response && (cmd->targ_xfer_tag == 0xFFFFFFFF))
+		cmd->targ_xfer_tag = conn->sess->targ_xfer_tag++;
+	spin_unlock_bh(&conn->sess->ttt_lock);
+
+	spin_lock_bh(&conn->cmd_lock);
+	list_add_tail(&cmd->i_list, &conn->conn_cmd_list);
+	spin_unlock_bh(&conn->cmd_lock);
+
+	if (want_response)
+		iscsit_start_nopin_response_timer(conn);
+	iscsit_add_cmd_to_immediate_queue(cmd, conn, state);
+
+	return 0;
+}
+
+static void iscsit_handle_nopin_response_timeout(unsigned long data)
+{
+	struct iscsi_conn *conn = (struct iscsi_conn *) data;
+
+	iscsit_inc_conn_usage_count(conn);
+
+	spin_lock_bh(&conn->nopin_timer_lock);
+	if (conn->nopin_response_timer_flags & ISCSI_TF_STOP) {
+		spin_unlock_bh(&conn->nopin_timer_lock);
+		iscsit_dec_conn_usage_count(conn);
+		return;
+	}
+
+	pr_debug("Did not receive response to NOPIN on CID: %hu on"
+		" SID: %u, failing connection.\n", conn->cid,
+			conn->sess->sid);
+	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
+	spin_unlock_bh(&conn->nopin_timer_lock);
+
+	{
+	struct iscsi_portal_group *tpg = conn->sess->tpg;
+	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
+
+	if (tiqn) {
+		spin_lock_bh(&tiqn->sess_err_stats.lock);
+		strcpy(tiqn->sess_err_stats.last_sess_fail_rem_name,
+				(void *)conn->sess->sess_ops->InitiatorName);
+		tiqn->sess_err_stats.last_sess_failure_type =
+				ISCSI_SESS_ERR_CXN_TIMEOUT;
+		tiqn->sess_err_stats.cxn_timeout_errors++;
+		conn->sess->conn_timeout_errors++;
+		spin_unlock_bh(&tiqn->sess_err_stats.lock);
+	}
+	}
+
+	iscsit_cause_connection_reinstatement(conn, 0);
+	iscsit_dec_conn_usage_count(conn);
+}
+
+void iscsit_mod_nopin_response_timer(struct iscsi_conn *conn)
+{
+	struct iscsi_session *sess = conn->sess;
+	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
+
+	spin_lock_bh(&conn->nopin_timer_lock);
+	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
+		spin_unlock_bh(&conn->nopin_timer_lock);
+		return;
+	}
+
+	mod_timer(&conn->nopin_response_timer,
+		(get_jiffies_64() + na->nopin_response_timeout * HZ));
+	spin_unlock_bh(&conn->nopin_timer_lock);
+}
+
+/*
+ *	Called with conn->nopin_timer_lock held.
+ */
+void iscsit_start_nopin_response_timer(struct iscsi_conn *conn)
+{
+	struct iscsi_session *sess = conn->sess;
+	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
+
+	spin_lock_bh(&conn->nopin_timer_lock);
+	if (conn->nopin_response_timer_flags & ISCSI_TF_RUNNING) {
+		spin_unlock_bh(&conn->nopin_timer_lock);
+		return;
+	}
+
+	init_timer(&conn->nopin_response_timer);
+	conn->nopin_response_timer.expires =
+		(get_jiffies_64() + na->nopin_response_timeout * HZ);
+	conn->nopin_response_timer.data = (unsigned long)conn;
+	conn->nopin_response_timer.function = iscsit_handle_nopin_response_timeout;
+	conn->nopin_response_timer_flags &= ~ISCSI_TF_STOP;
+	conn->nopin_response_timer_flags |= ISCSI_TF_RUNNING;
+	add_timer(&conn->nopin_response_timer);
+
+	pr_debug("Started NOPIN Response Timer on CID: %d to %u"
+		" seconds\n", conn->cid, na->nopin_response_timeout);
+	spin_unlock_bh(&conn->nopin_timer_lock);
+}
+
+void iscsit_stop_nopin_response_timer(struct iscsi_conn *conn)
+{
+	spin_lock_bh(&conn->nopin_timer_lock);
+	if (!(conn->nopin_response_timer_flags & ISCSI_TF_RUNNING)) {
+		spin_unlock_bh(&conn->nopin_timer_lock);
+		return;
+	}
+	conn->nopin_response_timer_flags |= ISCSI_TF_STOP;
+	spin_unlock_bh(&conn->nopin_timer_lock);
+
+	del_timer_sync(&conn->nopin_response_timer);
+
+	spin_lock_bh(&conn->nopin_timer_lock);
+	conn->nopin_response_timer_flags &= ~ISCSI_TF_RUNNING;
+	spin_unlock_bh(&conn->nopin_timer_lock);
+}
+
+static void iscsit_handle_nopin_timeout(unsigned long data)
+{
+	struct iscsi_conn *conn = (struct iscsi_conn *) data;
+
+	iscsit_inc_conn_usage_count(conn);
+
+	spin_lock_bh(&conn->nopin_timer_lock);
+	if (conn->nopin_timer_flags & ISCSI_TF_STOP) {
+		spin_unlock_bh(&conn->nopin_timer_lock);
+		iscsit_dec_conn_usage_count(conn);
+		return;
+	}
+	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
+	spin_unlock_bh(&conn->nopin_timer_lock);
+
+	iscsit_add_nopin(conn, 1);
+	iscsit_dec_conn_usage_count(conn);
+}
+
+/*
+ * Called with conn->nopin_timer_lock held.
+ */
+void __iscsit_start_nopin_timer(struct iscsi_conn *conn)
+{
+	struct iscsi_session *sess = conn->sess;
+	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
+	/*
+	* NOPIN timeout is disabled.
+	 */
+	if (!na->nopin_timeout)
+		return;
+
+	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING)
+		return;
+
+	init_timer(&conn->nopin_timer);
+	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
+	conn->nopin_timer.data = (unsigned long)conn;
+	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
+	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
+	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
+	add_timer(&conn->nopin_timer);
+
+	pr_debug("Started NOPIN Timer on CID: %d at %u second"
+		" interval\n", conn->cid, na->nopin_timeout);
+}
+
+void iscsit_start_nopin_timer(struct iscsi_conn *conn)
+{
+	struct iscsi_session *sess = conn->sess;
+	struct iscsi_node_attrib *na = iscsit_tpg_get_node_attrib(sess);
+	/*
+	 * NOPIN timeout is disabled..
+	 */
+	if (!na->nopin_timeout)
+		return;
+
+	spin_lock_bh(&conn->nopin_timer_lock);
+	if (conn->nopin_timer_flags & ISCSI_TF_RUNNING) {
+		spin_unlock_bh(&conn->nopin_timer_lock);
+		return;
+	}
+
+	init_timer(&conn->nopin_timer);
+	conn->nopin_timer.expires = (get_jiffies_64() + na->nopin_timeout * HZ);
+	conn->nopin_timer.data = (unsigned long)conn;
+	conn->nopin_timer.function = iscsit_handle_nopin_timeout;
+	conn->nopin_timer_flags &= ~ISCSI_TF_STOP;
+	conn->nopin_timer_flags |= ISCSI_TF_RUNNING;
+	add_timer(&conn->nopin_timer);
+
+	pr_debug("Started NOPIN Timer on CID: %d at %u second"
+			" interval\n", conn->cid, na->nopin_timeout);
+	spin_unlock_bh(&conn->nopin_timer_lock);
+}
+
+void iscsit_stop_nopin_timer(struct iscsi_conn *conn)
+{
+	spin_lock_bh(&conn->nopin_timer_lock);
+	if (!(conn->nopin_timer_flags & ISCSI_TF_RUNNING)) {
+		spin_unlock_bh(&conn->nopin_timer_lock);
+		return;
+	}
+	conn->nopin_timer_flags |= ISCSI_TF_STOP;
+	spin_unlock_bh(&conn->nopin_timer_lock);
+
+	del_timer_sync(&conn->nopin_timer);
+
+	spin_lock_bh(&conn->nopin_timer_lock);
+	conn->nopin_timer_flags &= ~ISCSI_TF_RUNNING;
+	spin_unlock_bh(&conn->nopin_timer_lock);
+}
+
+int iscsit_send_tx_data(
+	struct iscsi_cmd *cmd,
+	struct iscsi_conn *conn,
+	int use_misc)
+{
+	int tx_sent, tx_size;
+	u32 iov_count;
+	struct kvec *iov;
+
+send_data:
+	tx_size = cmd->tx_size;
+
+	if (!use_misc) {
+		iov = &cmd->iov_data[0];
+		iov_count = cmd->iov_data_count;
+	} else {
+		iov = &cmd->iov_misc[0];
+		iov_count = cmd->iov_misc_count;
+	}
+
+	tx_sent = tx_data(conn, &iov[0], iov_count, tx_size);
+	if (tx_size != tx_sent) {
+		if (tx_sent == -EAGAIN) {
+			pr_err("tx_data() returned -EAGAIN\n");
+			goto send_data;
+		} else
+			return -1;
+	}
+	cmd->tx_size = 0;
+
+	return 0;
+}
+
+int iscsit_fe_sendpage_sg(
+	struct iscsi_cmd *cmd,
+	struct iscsi_conn *conn)
+{
+	struct scatterlist *sg = cmd->first_data_sg;
+	struct kvec iov;
+	u32 tx_hdr_size, data_len;
+	u32 offset = cmd->first_data_sg_off;
+	int tx_sent;
+
+send_hdr:
+	tx_hdr_size = ISCSI_HDR_LEN;
+	if (conn->conn_ops->HeaderDigest)
+		tx_hdr_size += ISCSI_CRC_LEN;
+
+	iov.iov_base = cmd->pdu;
+	iov.iov_len = tx_hdr_size;
+
+	tx_sent = tx_data(conn, &iov, 1, tx_hdr_size);
+	if (tx_hdr_size != tx_sent) {
+		if (tx_sent == -EAGAIN) {
+			pr_err("tx_data() returned -EAGAIN\n");
+			goto send_hdr;
+		}
+		return -1;
+	}
+
+	data_len = cmd->tx_size - tx_hdr_size - cmd->padding;
+	if (conn->conn_ops->DataDigest)
+		data_len -= ISCSI_CRC_LEN;
+
+	/*
+	 * Perform sendpage() for each page in the scatterlist
+	 */
+	while (data_len) {
+		u32 space = (sg->length - offset);
+		u32 sub_len = min_t(u32, data_len, space);
+send_pg:
+		tx_sent = conn->sock->ops->sendpage(conn->sock,
+					sg_page(sg), sg->offset + offset, sub_len, 0);
+		if (tx_sent != sub_len) {
+			if (tx_sent == -EAGAIN) {
+				pr_err("tcp_sendpage() returned"
+						" -EAGAIN\n");
+				goto send_pg;
+			}
+
+			pr_err("tcp_sendpage() failure: %d\n",
+					tx_sent);
+			return -1;
+		}
+
+		data_len -= sub_len;
+		offset = 0;
+		sg = sg_next(sg);
+	}
+
+send_padding:
+	if (cmd->padding) {
+		struct kvec *iov_p =
+			&cmd->iov_data[cmd->iov_data_count-1];
+
+		tx_sent = tx_data(conn, iov_p, 1, cmd->padding);
+		if (cmd->padding != tx_sent) {
+			if (tx_sent == -EAGAIN) {
+				pr_err("tx_data() returned -EAGAIN\n");
+				goto send_padding;
+			}
+			return -1;
+		}
+	}
+
+send_datacrc:
+	if (conn->conn_ops->DataDigest) {
+		struct kvec *iov_d =
+			&cmd->iov_data[cmd->iov_data_count];
+
+		tx_sent = tx_data(conn, iov_d, 1, ISCSI_CRC_LEN);
+		if (ISCSI_CRC_LEN != tx_sent) {
+			if (tx_sent == -EAGAIN) {
+				pr_err("tx_data() returned -EAGAIN\n");
+				goto send_datacrc;
+			}
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+/*
+ *      This function is used for mainly sending a ISCSI_TARG_LOGIN_RSP PDU
+ *      back to the Initiator when an expection condition occurs with the
+ *      errors set in status_class and status_detail.
+ *
+ *      Parameters:     iSCSI Connection, Status Class, Status Detail.
+ *      Returns:        0 on success, -1 on error.
+ */
+int iscsit_tx_login_rsp(struct iscsi_conn *conn, u8 status_class, u8 status_detail)
+{
+	u8 iscsi_hdr[ISCSI_HDR_LEN];
+	int err;
+	struct kvec iov;
+	struct iscsi_login_rsp *hdr;
+
+	iscsit_collect_login_stats(conn, status_class, status_detail);
+
+	memset(&iov, 0, sizeof(struct kvec));
+	memset(&iscsi_hdr, 0x0, ISCSI_HDR_LEN);
+
+	hdr	= (struct iscsi_login_rsp *)&iscsi_hdr;
+	hdr->opcode		= ISCSI_OP_LOGIN_RSP;
+	hdr->status_class	= status_class;
+	hdr->status_detail	= status_detail;
+	hdr->itt		= cpu_to_be32(conn->login_itt);
+
+	iov.iov_base		= &iscsi_hdr;
+	iov.iov_len		= ISCSI_HDR_LEN;
+
+	PRINT_BUFF(iscsi_hdr, ISCSI_HDR_LEN);
+
+	err = tx_data(conn, &iov, 1, ISCSI_HDR_LEN);
+	if (err != ISCSI_HDR_LEN) {
+		pr_err("tx_data returned less than expected\n");
+		return -1;
+	}
+
+	return 0;
+}
+
+void iscsit_print_session_params(struct iscsi_session *sess)
+{
+	struct iscsi_conn *conn;
+
+	pr_debug("-----------------------------[Session Params for"
+		" SID: %u]-----------------------------\n", sess->sid);
+	spin_lock_bh(&sess->conn_lock);
+	list_for_each_entry(conn, &sess->sess_conn_list, conn_list)
+		iscsi_dump_conn_ops(conn->conn_ops);
+	spin_unlock_bh(&sess->conn_lock);
+
+	iscsi_dump_sess_ops(sess->sess_ops);
+}
+
+static int iscsit_do_rx_data(
+	struct iscsi_conn *conn,
+	struct iscsi_data_count *count)
+{
+	int data = count->data_length, rx_loop = 0, total_rx = 0, iov_len;
+	u32 rx_marker_val[count->ss_marker_count], rx_marker_iov = 0;
+	struct kvec iov[count->ss_iov_count], *iov_p;
+	struct msghdr msg;
+
+	if (!conn || !conn->sock || !conn->conn_ops)
+		return -1;
+
+	memset(&msg, 0, sizeof(struct msghdr));
+
+	if (count->sync_and_steering) {
+		int size = 0;
+		u32 i, orig_iov_count = 0;
+		u32 orig_iov_len = 0, orig_iov_loc = 0;
+		u32 iov_count = 0, per_iov_bytes = 0;
+		u32 *rx_marker, old_rx_marker = 0;
+		struct kvec *iov_record;
+
+		memset(&rx_marker_val, 0,
+				count->ss_marker_count * sizeof(u32));
+		memset(&iov, 0, count->ss_iov_count * sizeof(struct kvec));
+
+		iov_record = count->iov;
+		orig_iov_count = count->iov_count;
+		rx_marker = &conn->of_marker;
+
+		i = 0;
+		size = data;
+		orig_iov_len = iov_record[orig_iov_loc].iov_len;
+		while (size > 0) {
+			pr_debug("rx_data: #1 orig_iov_len %u,"
+			" orig_iov_loc %u\n", orig_iov_len, orig_iov_loc);
+			pr_debug("rx_data: #2 rx_marker %u, size"
+				" %u\n", *rx_marker, size);
+
+			if (orig_iov_len >= *rx_marker) {
+				iov[iov_count].iov_len = *rx_marker;
+				iov[iov_count++].iov_base =
+					(iov_record[orig_iov_loc].iov_base +
+						per_iov_bytes);
+
+				iov[iov_count].iov_len = (MARKER_SIZE / 2);
+				iov[iov_count++].iov_base =
+					&rx_marker_val[rx_marker_iov++];
+				iov[iov_count].iov_len = (MARKER_SIZE / 2);
+				iov[iov_count++].iov_base =
+					&rx_marker_val[rx_marker_iov++];
+				old_rx_marker = *rx_marker;
+
+				/*
+				 * OFMarkInt is in 32-bit words.
+				 */
+				*rx_marker = (conn->conn_ops->OFMarkInt * 4);
+				size -= old_rx_marker;
+				orig_iov_len -= old_rx_marker;
+				per_iov_bytes += old_rx_marker;
+
+				pr_debug("rx_data: #3 new_rx_marker"
+					" %u, size %u\n", *rx_marker, size);
+			} else {
+				iov[iov_count].iov_len = orig_iov_len;
+				iov[iov_count++].iov_base =
+					(iov_record[orig_iov_loc].iov_base +
+						per_iov_bytes);
+
+				per_iov_bytes = 0;
+				*rx_marker -= orig_iov_len;
+				size -= orig_iov_len;
+
+				if (size)
+					orig_iov_len =
+					iov_record[++orig_iov_loc].iov_len;
+
+				pr_debug("rx_data: #4 new_rx_marker"
+					" %u, size %u\n", *rx_marker, size);
+			}
+		}
+		data += (rx_marker_iov * (MARKER_SIZE / 2));
+
+		iov_p	= &iov[0];
+		iov_len	= iov_count;
+
+		if (iov_count > count->ss_iov_count) {
+			pr_err("iov_count: %d, count->ss_iov_count:"
+				" %d\n", iov_count, count->ss_iov_count);
+			return -1;
+		}
+		if (rx_marker_iov > count->ss_marker_count) {
+			pr_err("rx_marker_iov: %d, count->ss_marker"
+				"_count: %d\n", rx_marker_iov,
+				count->ss_marker_count);
+			return -1;
+		}
+	} else {
+		iov_p = count->iov;
+		iov_len	= count->iov_count;
+	}
+
+	while (total_rx < data) {
+		rx_loop = kernel_recvmsg(conn->sock, &msg, iov_p, iov_len,
+					(data - total_rx), MSG_WAITALL);
+		if (rx_loop <= 0) {
+			pr_debug("rx_loop: %d total_rx: %d\n",
+				rx_loop, total_rx);
+			return rx_loop;
+		}
+		total_rx += rx_loop;
+		pr_debug("rx_loop: %d, total_rx: %d, data: %d\n",
+				rx_loop, total_rx, data);
+	}
+
+	if (count->sync_and_steering) {
+		int j;
+		for (j = 0; j < rx_marker_iov; j++) {
+			pr_debug("rx_data: #5 j: %d, offset: %d\n",
+				j, rx_marker_val[j]);
+			conn->of_marker_offset = rx_marker_val[j];
+		}
+		total_rx -= (rx_marker_iov * (MARKER_SIZE / 2));
+	}
+
+	return total_rx;
+}
+
+static int iscsit_do_tx_data(
+	struct iscsi_conn *conn,
+	struct iscsi_data_count *count)
+{
+	int data = count->data_length, total_tx = 0, tx_loop = 0, iov_len;
+	u32 tx_marker_val[count->ss_marker_count], tx_marker_iov = 0;
+	struct kvec iov[count->ss_iov_count], *iov_p;
+	struct msghdr msg;
+
+	if (!conn || !conn->sock || !conn->conn_ops)
+		return -1;
+
+	if (data <= 0) {
+		pr_err("Data length is: %d\n", data);
+		return -1;
+	}
+
+	memset(&msg, 0, sizeof(struct msghdr));
+
+	if (count->sync_and_steering) {
+		int size = 0;
+		u32 i, orig_iov_count = 0;
+		u32 orig_iov_len = 0, orig_iov_loc = 0;
+		u32 iov_count = 0, per_iov_bytes = 0;
+		u32 *tx_marker, old_tx_marker = 0;
+		struct kvec *iov_record;
+
+		memset(&tx_marker_val, 0,
+			count->ss_marker_count * sizeof(u32));
+		memset(&iov, 0, count->ss_iov_count * sizeof(struct kvec));
+
+		iov_record = count->iov;
+		orig_iov_count = count->iov_count;
+		tx_marker = &conn->if_marker;
+
+		i = 0;
+		size = data;
+		orig_iov_len = iov_record[orig_iov_loc].iov_len;
+		while (size > 0) {
+			pr_debug("tx_data: #1 orig_iov_len %u,"
+			" orig_iov_loc %u\n", orig_iov_len, orig_iov_loc);
+			pr_debug("tx_data: #2 tx_marker %u, size"
+				" %u\n", *tx_marker, size);
+
+			if (orig_iov_len >= *tx_marker) {
+				iov[iov_count].iov_len = *tx_marker;
+				iov[iov_count++].iov_base =
+					(iov_record[orig_iov_loc].iov_base +
+						per_iov_bytes);
+
+				tx_marker_val[tx_marker_iov] =
+						(size - *tx_marker);
+				iov[iov_count].iov_len = (MARKER_SIZE / 2);
+				iov[iov_count++].iov_base =
+					&tx_marker_val[tx_marker_iov++];
+				iov[iov_count].iov_len = (MARKER_SIZE / 2);
+				iov[iov_count++].iov_base =
+					&tx_marker_val[tx_marker_iov++];
+				old_tx_marker = *tx_marker;
+
+				/*
+				 * IFMarkInt is in 32-bit words.
+				 */
+				*tx_marker = (conn->conn_ops->IFMarkInt * 4);
+				size -= old_tx_marker;
+				orig_iov_len -= old_tx_marker;
+				per_iov_bytes += old_tx_marker;
+
+				pr_debug("tx_data: #3 new_tx_marker"
+					" %u, size %u\n", *tx_marker, size);
+				pr_debug("tx_data: #4 offset %u\n",
+					tx_marker_val[tx_marker_iov-1]);
+			} else {
+				iov[iov_count].iov_len = orig_iov_len;
+				iov[iov_count++].iov_base
+					= (iov_record[orig_iov_loc].iov_base +
+						per_iov_bytes);
+
+				per_iov_bytes = 0;
+				*tx_marker -= orig_iov_len;
+				size -= orig_iov_len;
+
+				if (size)
+					orig_iov_len =
+					iov_record[++orig_iov_loc].iov_len;
+
+				pr_debug("tx_data: #5 new_tx_marker"
+					" %u, size %u\n", *tx_marker, size);
+			}
+		}
+
+		data += (tx_marker_iov * (MARKER_SIZE / 2));
+
+		iov_p = &iov[0];
+		iov_len = iov_count;
+
+		if (iov_count > count->ss_iov_count) {
+			pr_err("iov_count: %d, count->ss_iov_count:"
+				" %d\n", iov_count, count->ss_iov_count);
+			return -1;
+		}
+		if (tx_marker_iov > count->ss_marker_count) {
+			pr_err("tx_marker_iov: %d, count->ss_marker"
+				"_count: %d\n", tx_marker_iov,
+				count->ss_marker_count);
+			return -1;
+		}
+	} else {
+		iov_p = count->iov;
+		iov_len = count->iov_count;
+	}
+
+	while (total_tx < data) {
+		tx_loop = kernel_sendmsg(conn->sock, &msg, iov_p, iov_len,
+					(data - total_tx));
+		if (tx_loop <= 0) {
+			pr_debug("tx_loop: %d total_tx %d\n",
+				tx_loop, total_tx);
+			return tx_loop;
+		}
+		total_tx += tx_loop;
+		pr_debug("tx_loop: %d, total_tx: %d, data: %d\n",
+					tx_loop, total_tx, data);
+	}
+
+	if (count->sync_and_steering)
+		total_tx -= (tx_marker_iov * (MARKER_SIZE / 2));
+
+	return total_tx;
+}
+
+int rx_data(
+	struct iscsi_conn *conn,
+	struct kvec *iov,
+	int iov_count,
+	int data)
+{
+	struct iscsi_data_count c;
+
+	if (!conn || !conn->sock || !conn->conn_ops)
+		return -1;
+
+	memset(&c, 0, sizeof(struct iscsi_data_count));
+	c.iov = iov;
+	c.iov_count = iov_count;
+	c.data_length = data;
+	c.type = ISCSI_RX_DATA;
+
+	if (conn->conn_ops->OFMarker &&
+	   (conn->conn_state >= TARG_CONN_STATE_LOGGED_IN)) {
+		if (iscsit_determine_sync_and_steering_counts(conn, &c) < 0)
+			return -1;
+	}
+
+	return iscsit_do_rx_data(conn, &c);
+}
+
+int tx_data(
+	struct iscsi_conn *conn,
+	struct kvec *iov,
+	int iov_count,
+	int data)
+{
+	struct iscsi_data_count c;
+
+	if (!conn || !conn->sock || !conn->conn_ops)
+		return -1;
+
+	memset(&c, 0, sizeof(struct iscsi_data_count));
+	c.iov = iov;
+	c.iov_count = iov_count;
+	c.data_length = data;
+	c.type = ISCSI_TX_DATA;
+
+	if (conn->conn_ops->IFMarker &&
+	   (conn->conn_state >= TARG_CONN_STATE_LOGGED_IN)) {
+		if (iscsit_determine_sync_and_steering_counts(conn, &c) < 0)
+			return -1;
+	}
+
+	return iscsit_do_tx_data(conn, &c);
+}
+
+void iscsit_collect_login_stats(
+	struct iscsi_conn *conn,
+	u8 status_class,
+	u8 status_detail)
+{
+	struct iscsi_param *intrname = NULL;
+	struct iscsi_tiqn *tiqn;
+	struct iscsi_login_stats *ls;
+
+	tiqn = iscsit_snmp_get_tiqn(conn);
+	if (!tiqn)
+		return;
+
+	ls = &tiqn->login_stats;
+
+	spin_lock(&ls->lock);
+	if (!strcmp(conn->login_ip, ls->last_intr_fail_ip_addr) &&
+	    ((get_jiffies_64() - ls->last_fail_time) < 10)) {
+		/* We already have the failure info for this login */
+		spin_unlock(&ls->lock);
+		return;
+	}
+
+	if (status_class == ISCSI_STATUS_CLS_SUCCESS)
+		ls->accepts++;
+	else if (status_class == ISCSI_STATUS_CLS_REDIRECT) {
+		ls->redirects++;
+		ls->last_fail_type = ISCSI_LOGIN_FAIL_REDIRECT;
+	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
+		 (status_detail == ISCSI_LOGIN_STATUS_AUTH_FAILED)) {
+		ls->authenticate_fails++;
+		ls->last_fail_type =  ISCSI_LOGIN_FAIL_AUTHENTICATE;
+	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR)  &&
+		 (status_detail == ISCSI_LOGIN_STATUS_TGT_FORBIDDEN)) {
+		ls->authorize_fails++;
+		ls->last_fail_type = ISCSI_LOGIN_FAIL_AUTHORIZE;
+	} else if ((status_class == ISCSI_STATUS_CLS_INITIATOR_ERR) &&
+		 (status_detail == ISCSI_LOGIN_STATUS_INIT_ERR)) {
+		ls->negotiate_fails++;
+		ls->last_fail_type = ISCSI_LOGIN_FAIL_NEGOTIATE;
+	} else {
+		ls->other_fails++;
+		ls->last_fail_type = ISCSI_LOGIN_FAIL_OTHER;
+	}
+
+	/* Save initiator name, ip address and time, if it is a failed login */
+	if (status_class != ISCSI_STATUS_CLS_SUCCESS) {
+		if (conn->param_list)
+			intrname = iscsi_find_param_from_key(INITIATORNAME,
+							     conn->param_list);
+		strcpy(ls->last_intr_fail_name,
+		       (intrname ? intrname->value : "Unknown"));
+
+		ls->last_intr_fail_ip_family = conn->sock->sk->sk_family;
+		snprintf(ls->last_intr_fail_ip_addr, IPV6_ADDRESS_SPACE,
+				"%s", conn->login_ip);
+		ls->last_fail_time = get_jiffies_64();
+	}
+
+	spin_unlock(&ls->lock);
+}
+
+struct iscsi_tiqn *iscsit_snmp_get_tiqn(struct iscsi_conn *conn)
+{
+	struct iscsi_portal_group *tpg;
+
+	if (!conn || !conn->sess)
+		return NULL;
+
+	tpg = conn->sess->tpg;
+	if (!tpg)
+		return NULL;
+
+	if (!tpg->tpg_tiqn)
+		return NULL;
+
+	return tpg->tpg_tiqn;
+}