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>
diff --git a/drivers/target/iscsi/iscsi_target_seq_pdu_list.c b/drivers/target/iscsi/iscsi_target_seq_pdu_list.c
new file mode 100644
index 0000000..fc69408
--- /dev/null
+++ b/drivers/target/iscsi/iscsi_target_seq_pdu_list.c
@@ -0,0 +1,664 @@
+/*******************************************************************************
+ * This file contains main functions related to iSCSI DataSequenceInOrder=No
+ * and DataPDUInOrder=No.
+ *
+ \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/slab.h>
+#include <linux/random.h>
+
+#include "iscsi_target_core.h"
+#include "iscsi_target_util.h"
+#include "iscsi_target_seq_pdu_list.h"
+
+#define OFFLOAD_BUF_SIZE 32768
+
+void iscsit_dump_seq_list(struct iscsi_cmd *cmd)
+{
+ int i;
+ struct iscsi_seq *seq;
+
+ pr_debug("Dumping Sequence List for ITT: 0x%08x:\n",
+ cmd->init_task_tag);
+
+ for (i = 0; i < cmd->seq_count; i++) {
+ seq = &cmd->seq_list[i];
+ pr_debug("i: %d, pdu_start: %d, pdu_count: %d,"
+ " offset: %d, xfer_len: %d, seq_send_order: %d,"
+ " seq_no: %d\n", i, seq->pdu_start, seq->pdu_count,
+ seq->offset, seq->xfer_len, seq->seq_send_order,
+ seq->seq_no);
+ }
+}
+
+void iscsit_dump_pdu_list(struct iscsi_cmd *cmd)
+{
+ int i;
+ struct iscsi_pdu *pdu;
+
+ pr_debug("Dumping PDU List for ITT: 0x%08x:\n",
+ cmd->init_task_tag);
+
+ for (i = 0; i < cmd->pdu_count; i++) {
+ pdu = &cmd->pdu_list[i];
+ pr_debug("i: %d, offset: %d, length: %d,"
+ " pdu_send_order: %d, seq_no: %d\n", i, pdu->offset,
+ pdu->length, pdu->pdu_send_order, pdu->seq_no);
+ }
+}
+
+static void iscsit_ordered_seq_lists(
+ struct iscsi_cmd *cmd,
+ u8 type)
+{
+ u32 i, seq_count = 0;
+
+ for (i = 0; i < cmd->seq_count; i++) {
+ if (cmd->seq_list[i].type != SEQTYPE_NORMAL)
+ continue;
+ cmd->seq_list[i].seq_send_order = seq_count++;
+ }
+}
+
+static void iscsit_ordered_pdu_lists(
+ struct iscsi_cmd *cmd,
+ u8 type)
+{
+ u32 i, pdu_send_order = 0, seq_no = 0;
+
+ for (i = 0; i < cmd->pdu_count; i++) {
+redo:
+ if (cmd->pdu_list[i].seq_no == seq_no) {
+ cmd->pdu_list[i].pdu_send_order = pdu_send_order++;
+ continue;
+ }
+ seq_no++;
+ pdu_send_order = 0;
+ goto redo;
+ }
+}
+
+/*
+ * Generate count random values into array.
+ * Use 0x80000000 to mark generates valued in array[].
+ */
+static void iscsit_create_random_array(u32 *array, u32 count)
+{
+ int i, j, k;
+
+ if (count == 1) {
+ array[0] = 0;
+ return;
+ }
+
+ for (i = 0; i < count; i++) {
+redo:
+ get_random_bytes(&j, sizeof(u32));
+ j = (1 + (int) (9999 + 1) - j) % count;
+ for (k = 0; k < i + 1; k++) {
+ j |= 0x80000000;
+ if ((array[k] & 0x80000000) && (array[k] == j))
+ goto redo;
+ }
+ array[i] = j;
+ }
+
+ for (i = 0; i < count; i++)
+ array[i] &= ~0x80000000;
+}
+
+static int iscsit_randomize_pdu_lists(
+ struct iscsi_cmd *cmd,
+ u8 type)
+{
+ int i = 0;
+ u32 *array, pdu_count, seq_count = 0, seq_no = 0, seq_offset = 0;
+
+ for (pdu_count = 0; pdu_count < cmd->pdu_count; pdu_count++) {
+redo:
+ if (cmd->pdu_list[pdu_count].seq_no == seq_no) {
+ seq_count++;
+ continue;
+ }
+ array = kzalloc(seq_count * sizeof(u32), GFP_KERNEL);
+ if (!array) {
+ pr_err("Unable to allocate memory"
+ " for random array.\n");
+ return -1;
+ }
+ iscsit_create_random_array(array, seq_count);
+
+ for (i = 0; i < seq_count; i++)
+ cmd->pdu_list[seq_offset+i].pdu_send_order = array[i];
+
+ kfree(array);
+
+ seq_offset += seq_count;
+ seq_count = 0;
+ seq_no++;
+ goto redo;
+ }
+
+ if (seq_count) {
+ array = kzalloc(seq_count * sizeof(u32), GFP_KERNEL);
+ if (!array) {
+ pr_err("Unable to allocate memory for"
+ " random array.\n");
+ return -1;
+ }
+ iscsit_create_random_array(array, seq_count);
+
+ for (i = 0; i < seq_count; i++)
+ cmd->pdu_list[seq_offset+i].pdu_send_order = array[i];
+
+ kfree(array);
+ }
+
+ return 0;
+}
+
+static int iscsit_randomize_seq_lists(
+ struct iscsi_cmd *cmd,
+ u8 type)
+{
+ int i, j = 0;
+ u32 *array, seq_count = cmd->seq_count;
+
+ if ((type == PDULIST_IMMEDIATE) || (type == PDULIST_UNSOLICITED))
+ seq_count--;
+ else if (type == PDULIST_IMMEDIATE_AND_UNSOLICITED)
+ seq_count -= 2;
+
+ if (!seq_count)
+ return 0;
+
+ array = kzalloc(seq_count * sizeof(u32), GFP_KERNEL);
+ if (!array) {
+ pr_err("Unable to allocate memory for random array.\n");
+ return -1;
+ }
+ iscsit_create_random_array(array, seq_count);
+
+ for (i = 0; i < cmd->seq_count; i++) {
+ if (cmd->seq_list[i].type != SEQTYPE_NORMAL)
+ continue;
+ cmd->seq_list[i].seq_send_order = array[j++];
+ }
+
+ kfree(array);
+ return 0;
+}
+
+static void iscsit_determine_counts_for_list(
+ struct iscsi_cmd *cmd,
+ struct iscsi_build_list *bl,
+ u32 *seq_count,
+ u32 *pdu_count)
+{
+ int check_immediate = 0;
+ u32 burstlength = 0, offset = 0;
+ u32 unsolicited_data_length = 0;
+ struct iscsi_conn *conn = cmd->conn;
+
+ if ((bl->type == PDULIST_IMMEDIATE) ||
+ (bl->type == PDULIST_IMMEDIATE_AND_UNSOLICITED))
+ check_immediate = 1;
+
+ if ((bl->type == PDULIST_UNSOLICITED) ||
+ (bl->type == PDULIST_IMMEDIATE_AND_UNSOLICITED))
+ unsolicited_data_length = (cmd->data_length >
+ conn->sess->sess_ops->FirstBurstLength) ?
+ conn->sess->sess_ops->FirstBurstLength : cmd->data_length;
+
+ while (offset < cmd->data_length) {
+ *pdu_count += 1;
+
+ if (check_immediate) {
+ check_immediate = 0;
+ offset += bl->immediate_data_length;
+ *seq_count += 1;
+ if (unsolicited_data_length)
+ unsolicited_data_length -=
+ bl->immediate_data_length;
+ continue;
+ }
+ if (unsolicited_data_length > 0) {
+ if ((offset + conn->conn_ops->MaxRecvDataSegmentLength)
+ >= cmd->data_length) {
+ unsolicited_data_length -=
+ (cmd->data_length - offset);
+ offset += (cmd->data_length - offset);
+ continue;
+ }
+ if ((offset + conn->conn_ops->MaxRecvDataSegmentLength)
+ >= conn->sess->sess_ops->FirstBurstLength) {
+ unsolicited_data_length -=
+ (conn->sess->sess_ops->FirstBurstLength -
+ offset);
+ offset += (conn->sess->sess_ops->FirstBurstLength -
+ offset);
+ burstlength = 0;
+ *seq_count += 1;
+ continue;
+ }
+
+ offset += conn->conn_ops->MaxRecvDataSegmentLength;
+ unsolicited_data_length -=
+ conn->conn_ops->MaxRecvDataSegmentLength;
+ continue;
+ }
+ if ((offset + conn->conn_ops->MaxRecvDataSegmentLength) >=
+ cmd->data_length) {
+ offset += (cmd->data_length - offset);
+ continue;
+ }
+ if ((burstlength + conn->conn_ops->MaxRecvDataSegmentLength) >=
+ conn->sess->sess_ops->MaxBurstLength) {
+ offset += (conn->sess->sess_ops->MaxBurstLength -
+ burstlength);
+ burstlength = 0;
+ *seq_count += 1;
+ continue;
+ }
+
+ burstlength += conn->conn_ops->MaxRecvDataSegmentLength;
+ offset += conn->conn_ops->MaxRecvDataSegmentLength;
+ }
+}
+
+
+/*
+ * Builds PDU and/or Sequence list, called while DataSequenceInOrder=No
+ * and DataPDUInOrder=No.
+ */
+static int iscsit_build_pdu_and_seq_list(
+ struct iscsi_cmd *cmd,
+ struct iscsi_build_list *bl)
+{
+ int check_immediate = 0, datapduinorder, datasequenceinorder;
+ u32 burstlength = 0, offset = 0, i = 0;
+ u32 pdu_count = 0, seq_no = 0, unsolicited_data_length = 0;
+ struct iscsi_conn *conn = cmd->conn;
+ struct iscsi_pdu *pdu = cmd->pdu_list;
+ struct iscsi_seq *seq = cmd->seq_list;
+
+ datapduinorder = conn->sess->sess_ops->DataPDUInOrder;
+ datasequenceinorder = conn->sess->sess_ops->DataSequenceInOrder;
+
+ if ((bl->type == PDULIST_IMMEDIATE) ||
+ (bl->type == PDULIST_IMMEDIATE_AND_UNSOLICITED))
+ check_immediate = 1;
+
+ if ((bl->type == PDULIST_UNSOLICITED) ||
+ (bl->type == PDULIST_IMMEDIATE_AND_UNSOLICITED))
+ unsolicited_data_length = (cmd->data_length >
+ conn->sess->sess_ops->FirstBurstLength) ?
+ conn->sess->sess_ops->FirstBurstLength : cmd->data_length;
+
+ while (offset < cmd->data_length) {
+ pdu_count++;
+ if (!datapduinorder) {
+ pdu[i].offset = offset;
+ pdu[i].seq_no = seq_no;
+ }
+ if (!datasequenceinorder && (pdu_count == 1)) {
+ seq[seq_no].pdu_start = i;
+ seq[seq_no].seq_no = seq_no;
+ seq[seq_no].offset = offset;
+ seq[seq_no].orig_offset = offset;
+ }
+
+ if (check_immediate) {
+ check_immediate = 0;
+ if (!datapduinorder) {
+ pdu[i].type = PDUTYPE_IMMEDIATE;
+ pdu[i++].length = bl->immediate_data_length;
+ }
+ if (!datasequenceinorder) {
+ seq[seq_no].type = SEQTYPE_IMMEDIATE;
+ seq[seq_no].pdu_count = 1;
+ seq[seq_no].xfer_len =
+ bl->immediate_data_length;
+ }
+ offset += bl->immediate_data_length;
+ pdu_count = 0;
+ seq_no++;
+ if (unsolicited_data_length)
+ unsolicited_data_length -=
+ bl->immediate_data_length;
+ continue;
+ }
+ if (unsolicited_data_length > 0) {
+ if ((offset +
+ conn->conn_ops->MaxRecvDataSegmentLength) >=
+ cmd->data_length) {
+ if (!datapduinorder) {
+ pdu[i].type = PDUTYPE_UNSOLICITED;
+ pdu[i].length =
+ (cmd->data_length - offset);
+ }
+ if (!datasequenceinorder) {
+ seq[seq_no].type = SEQTYPE_UNSOLICITED;
+ seq[seq_no].pdu_count = pdu_count;
+ seq[seq_no].xfer_len = (burstlength +
+ (cmd->data_length - offset));
+ }
+ unsolicited_data_length -=
+ (cmd->data_length - offset);
+ offset += (cmd->data_length - offset);
+ continue;
+ }
+ if ((offset +
+ conn->conn_ops->MaxRecvDataSegmentLength) >=
+ conn->sess->sess_ops->FirstBurstLength) {
+ if (!datapduinorder) {
+ pdu[i].type = PDUTYPE_UNSOLICITED;
+ pdu[i++].length =
+ (conn->sess->sess_ops->FirstBurstLength -
+ offset);
+ }
+ if (!datasequenceinorder) {
+ seq[seq_no].type = SEQTYPE_UNSOLICITED;
+ seq[seq_no].pdu_count = pdu_count;
+ seq[seq_no].xfer_len = (burstlength +
+ (conn->sess->sess_ops->FirstBurstLength -
+ offset));
+ }
+ unsolicited_data_length -=
+ (conn->sess->sess_ops->FirstBurstLength -
+ offset);
+ offset += (conn->sess->sess_ops->FirstBurstLength -
+ offset);
+ burstlength = 0;
+ pdu_count = 0;
+ seq_no++;
+ continue;
+ }
+
+ if (!datapduinorder) {
+ pdu[i].type = PDUTYPE_UNSOLICITED;
+ pdu[i++].length =
+ conn->conn_ops->MaxRecvDataSegmentLength;
+ }
+ burstlength += conn->conn_ops->MaxRecvDataSegmentLength;
+ offset += conn->conn_ops->MaxRecvDataSegmentLength;
+ unsolicited_data_length -=
+ conn->conn_ops->MaxRecvDataSegmentLength;
+ continue;
+ }
+ if ((offset + conn->conn_ops->MaxRecvDataSegmentLength) >=
+ cmd->data_length) {
+ if (!datapduinorder) {
+ pdu[i].type = PDUTYPE_NORMAL;
+ pdu[i].length = (cmd->data_length - offset);
+ }
+ if (!datasequenceinorder) {
+ seq[seq_no].type = SEQTYPE_NORMAL;
+ seq[seq_no].pdu_count = pdu_count;
+ seq[seq_no].xfer_len = (burstlength +
+ (cmd->data_length - offset));
+ }
+ offset += (cmd->data_length - offset);
+ continue;
+ }
+ if ((burstlength + conn->conn_ops->MaxRecvDataSegmentLength) >=
+ conn->sess->sess_ops->MaxBurstLength) {
+ if (!datapduinorder) {
+ pdu[i].type = PDUTYPE_NORMAL;
+ pdu[i++].length =
+ (conn->sess->sess_ops->MaxBurstLength -
+ burstlength);
+ }
+ if (!datasequenceinorder) {
+ seq[seq_no].type = SEQTYPE_NORMAL;
+ seq[seq_no].pdu_count = pdu_count;
+ seq[seq_no].xfer_len = (burstlength +
+ (conn->sess->sess_ops->MaxBurstLength -
+ burstlength));
+ }
+ offset += (conn->sess->sess_ops->MaxBurstLength -
+ burstlength);
+ burstlength = 0;
+ pdu_count = 0;
+ seq_no++;
+ continue;
+ }
+
+ if (!datapduinorder) {
+ pdu[i].type = PDUTYPE_NORMAL;
+ pdu[i++].length =
+ conn->conn_ops->MaxRecvDataSegmentLength;
+ }
+ burstlength += conn->conn_ops->MaxRecvDataSegmentLength;
+ offset += conn->conn_ops->MaxRecvDataSegmentLength;
+ }
+
+ if (!datasequenceinorder) {
+ if (bl->data_direction & ISCSI_PDU_WRITE) {
+ if (bl->randomize & RANDOM_R2T_OFFSETS) {
+ if (iscsit_randomize_seq_lists(cmd, bl->type)
+ < 0)
+ return -1;
+ } else
+ iscsit_ordered_seq_lists(cmd, bl->type);
+ } else if (bl->data_direction & ISCSI_PDU_READ) {
+ if (bl->randomize & RANDOM_DATAIN_SEQ_OFFSETS) {
+ if (iscsit_randomize_seq_lists(cmd, bl->type)
+ < 0)
+ return -1;
+ } else
+ iscsit_ordered_seq_lists(cmd, bl->type);
+ }
+#if 0
+ iscsit_dump_seq_list(cmd);
+#endif
+ }
+ if (!datapduinorder) {
+ if (bl->data_direction & ISCSI_PDU_WRITE) {
+ if (bl->randomize & RANDOM_DATAOUT_PDU_OFFSETS) {
+ if (iscsit_randomize_pdu_lists(cmd, bl->type)
+ < 0)
+ return -1;
+ } else
+ iscsit_ordered_pdu_lists(cmd, bl->type);
+ } else if (bl->data_direction & ISCSI_PDU_READ) {
+ if (bl->randomize & RANDOM_DATAIN_PDU_OFFSETS) {
+ if (iscsit_randomize_pdu_lists(cmd, bl->type)
+ < 0)
+ return -1;
+ } else
+ iscsit_ordered_pdu_lists(cmd, bl->type);
+ }
+#if 0
+ iscsit_dump_pdu_list(cmd);
+#endif
+ }
+
+ return 0;
+}
+
+/*
+ * Only called while DataSequenceInOrder=No or DataPDUInOrder=No.
+ */
+int iscsit_do_build_list(
+ struct iscsi_cmd *cmd,
+ struct iscsi_build_list *bl)
+{
+ u32 pdu_count = 0, seq_count = 1;
+ struct iscsi_conn *conn = cmd->conn;
+ struct iscsi_pdu *pdu = NULL;
+ struct iscsi_seq *seq = NULL;
+
+ iscsit_determine_counts_for_list(cmd, bl, &seq_count, &pdu_count);
+
+ if (!conn->sess->sess_ops->DataSequenceInOrder) {
+ seq = kzalloc(seq_count * sizeof(struct iscsi_seq), GFP_ATOMIC);
+ if (!seq) {
+ pr_err("Unable to allocate struct iscsi_seq list\n");
+ return -1;
+ }
+ cmd->seq_list = seq;
+ cmd->seq_count = seq_count;
+ }
+
+ if (!conn->sess->sess_ops->DataPDUInOrder) {
+ pdu = kzalloc(pdu_count * sizeof(struct iscsi_pdu), GFP_ATOMIC);
+ if (!pdu) {
+ pr_err("Unable to allocate struct iscsi_pdu list.\n");
+ kfree(seq);
+ return -1;
+ }
+ cmd->pdu_list = pdu;
+ cmd->pdu_count = pdu_count;
+ }
+
+ return iscsit_build_pdu_and_seq_list(cmd, bl);
+}
+
+struct iscsi_pdu *iscsit_get_pdu_holder(
+ struct iscsi_cmd *cmd,
+ u32 offset,
+ u32 length)
+{
+ u32 i;
+ struct iscsi_pdu *pdu = NULL;
+
+ if (!cmd->pdu_list) {
+ pr_err("struct iscsi_cmd->pdu_list is NULL!\n");
+ return NULL;
+ }
+
+ pdu = &cmd->pdu_list[0];
+
+ for (i = 0; i < cmd->pdu_count; i++)
+ if ((pdu[i].offset == offset) && (pdu[i].length == length))
+ return &pdu[i];
+
+ pr_err("Unable to locate PDU holder for ITT: 0x%08x, Offset:"
+ " %u, Length: %u\n", cmd->init_task_tag, offset, length);
+ return NULL;
+}
+
+struct iscsi_pdu *iscsit_get_pdu_holder_for_seq(
+ struct iscsi_cmd *cmd,
+ struct iscsi_seq *seq)
+{
+ u32 i;
+ struct iscsi_conn *conn = cmd->conn;
+ struct iscsi_pdu *pdu = NULL;
+
+ if (!cmd->pdu_list) {
+ pr_err("struct iscsi_cmd->pdu_list is NULL!\n");
+ return NULL;
+ }
+
+ if (conn->sess->sess_ops->DataSequenceInOrder) {
+redo:
+ pdu = &cmd->pdu_list[cmd->pdu_start];
+
+ for (i = 0; pdu[i].seq_no != cmd->seq_no; i++) {
+#if 0
+ pr_debug("pdu[i].seq_no: %d, pdu[i].pdu"
+ "_send_order: %d, pdu[i].offset: %d,"
+ " pdu[i].length: %d\n", pdu[i].seq_no,
+ pdu[i].pdu_send_order, pdu[i].offset,
+ pdu[i].length);
+#endif
+ if (pdu[i].pdu_send_order == cmd->pdu_send_order) {
+ cmd->pdu_send_order++;
+ return &pdu[i];
+ }
+ }
+
+ cmd->pdu_start += cmd->pdu_send_order;
+ cmd->pdu_send_order = 0;
+ cmd->seq_no++;
+
+ if (cmd->pdu_start < cmd->pdu_count)
+ goto redo;
+
+ pr_err("Command ITT: 0x%08x unable to locate"
+ " struct iscsi_pdu for cmd->pdu_send_order: %u.\n",
+ cmd->init_task_tag, cmd->pdu_send_order);
+ return NULL;
+ } else {
+ if (!seq) {
+ pr_err("struct iscsi_seq is NULL!\n");
+ return NULL;
+ }
+#if 0
+ pr_debug("seq->pdu_start: %d, seq->pdu_count: %d,"
+ " seq->seq_no: %d\n", seq->pdu_start, seq->pdu_count,
+ seq->seq_no);
+#endif
+ pdu = &cmd->pdu_list[seq->pdu_start];
+
+ if (seq->pdu_send_order == seq->pdu_count) {
+ pr_err("Command ITT: 0x%08x seq->pdu_send"
+ "_order: %u equals seq->pdu_count: %u\n",
+ cmd->init_task_tag, seq->pdu_send_order,
+ seq->pdu_count);
+ return NULL;
+ }
+
+ for (i = 0; i < seq->pdu_count; i++) {
+ if (pdu[i].pdu_send_order == seq->pdu_send_order) {
+ seq->pdu_send_order++;
+ return &pdu[i];
+ }
+ }
+
+ pr_err("Command ITT: 0x%08x unable to locate iscsi"
+ "_pdu_t for seq->pdu_send_order: %u.\n",
+ cmd->init_task_tag, seq->pdu_send_order);
+ return NULL;
+ }
+
+ return NULL;
+}
+
+struct iscsi_seq *iscsit_get_seq_holder(
+ struct iscsi_cmd *cmd,
+ u32 offset,
+ u32 length)
+{
+ 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 0
+ pr_debug("seq_list[i].orig_offset: %d, seq_list[i]."
+ "xfer_len: %d, seq_list[i].seq_no %u\n",
+ cmd->seq_list[i].orig_offset, cmd->seq_list[i].xfer_len,
+ cmd->seq_list[i].seq_no);
+#endif
+ if ((cmd->seq_list[i].orig_offset +
+ cmd->seq_list[i].xfer_len) >=
+ (offset + length))
+ return &cmd->seq_list[i];
+ }
+
+ pr_err("Unable to locate Sequence holder for ITT: 0x%08x,"
+ " Offset: %u, Length: %u\n", cmd->init_task_tag, offset,
+ length);
+ return NULL;
+}