Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / scsi / libiscsi.c
diff --git a/kernel/drivers/scsi/libiscsi.c b/kernel/drivers/scsi/libiscsi.c
new file mode 100644 (file)
index 0000000..8053f24
--- /dev/null
@@ -0,0 +1,3649 @@
+/*
+ * iSCSI lib functions
+ *
+ * Copyright (C) 2006 Red Hat, Inc.  All rights reserved.
+ * Copyright (C) 2004 - 2006 Mike Christie
+ * Copyright (C) 2004 - 2005 Dmitry Yusupov
+ * Copyright (C) 2004 - 2005 Alex Aizman
+ * maintained by open-iscsi@googlegroups.com
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ */
+#include <linux/types.h>
+#include <linux/kfifo.h>
+#include <linux/delay.h>
+#include <linux/log2.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <asm/unaligned.h>
+#include <net/tcp.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+#include <scsi/scsi_eh.h>
+#include <scsi/scsi_tcq.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi.h>
+#include <scsi/iscsi_proto.h>
+#include <scsi/scsi_transport.h>
+#include <scsi/scsi_transport_iscsi.h>
+#include <scsi/libiscsi.h>
+
+static int iscsi_dbg_lib_conn;
+module_param_named(debug_libiscsi_conn, iscsi_dbg_lib_conn, int,
+                  S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug_libiscsi_conn,
+                "Turn on debugging for connections in libiscsi module. "
+                "Set to 1 to turn on, and zero to turn off. Default is off.");
+
+static int iscsi_dbg_lib_session;
+module_param_named(debug_libiscsi_session, iscsi_dbg_lib_session, int,
+                  S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug_libiscsi_session,
+                "Turn on debugging for sessions in libiscsi module. "
+                "Set to 1 to turn on, and zero to turn off. Default is off.");
+
+static int iscsi_dbg_lib_eh;
+module_param_named(debug_libiscsi_eh, iscsi_dbg_lib_eh, int,
+                  S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(debug_libiscsi_eh,
+                "Turn on debugging for error handling in libiscsi module. "
+                "Set to 1 to turn on, and zero to turn off. Default is off.");
+
+#define ISCSI_DBG_CONN(_conn, dbg_fmt, arg...)                 \
+       do {                                                    \
+               if (iscsi_dbg_lib_conn)                         \
+                       iscsi_conn_printk(KERN_INFO, _conn,     \
+                                            "%s " dbg_fmt,     \
+                                            __func__, ##arg);  \
+       } while (0);
+
+#define ISCSI_DBG_SESSION(_session, dbg_fmt, arg...)                   \
+       do {                                                            \
+               if (iscsi_dbg_lib_session)                              \
+                       iscsi_session_printk(KERN_INFO, _session,       \
+                                            "%s " dbg_fmt,             \
+                                            __func__, ##arg);          \
+       } while (0);
+
+#define ISCSI_DBG_EH(_session, dbg_fmt, arg...)                                \
+       do {                                                            \
+               if (iscsi_dbg_lib_eh)                                   \
+                       iscsi_session_printk(KERN_INFO, _session,       \
+                                            "%s " dbg_fmt,             \
+                                            __func__, ##arg);          \
+       } while (0);
+
+inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
+{
+       struct Scsi_Host *shost = conn->session->host;
+       struct iscsi_host *ihost = shost_priv(shost);
+
+       if (ihost->workq)
+               queue_work(ihost->workq, &conn->xmitwork);
+}
+EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
+
+static void __iscsi_update_cmdsn(struct iscsi_session *session,
+                                uint32_t exp_cmdsn, uint32_t max_cmdsn)
+{
+       /*
+        * standard specifies this check for when to update expected and
+        * max sequence numbers
+        */
+       if (iscsi_sna_lt(max_cmdsn, exp_cmdsn - 1))
+               return;
+
+       if (exp_cmdsn != session->exp_cmdsn &&
+           !iscsi_sna_lt(exp_cmdsn, session->exp_cmdsn))
+               session->exp_cmdsn = exp_cmdsn;
+
+       if (max_cmdsn != session->max_cmdsn &&
+           !iscsi_sna_lt(max_cmdsn, session->max_cmdsn))
+               session->max_cmdsn = max_cmdsn;
+}
+
+void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
+{
+       __iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
+                            be32_to_cpu(hdr->max_cmdsn));
+}
+EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
+
+/**
+ * iscsi_prep_data_out_pdu - initialize Data-Out
+ * @task: scsi command task
+ * @r2t: R2T info
+ * @hdr: iscsi data in pdu
+ *
+ * Notes:
+ *     Initialize Data-Out within this R2T sequence and finds
+ *     proper data_offset within this SCSI command.
+ *
+ *     This function is called with connection lock taken.
+ **/
+void iscsi_prep_data_out_pdu(struct iscsi_task *task, struct iscsi_r2t_info *r2t,
+                          struct iscsi_data *hdr)
+{
+       struct iscsi_conn *conn = task->conn;
+       unsigned int left = r2t->data_length - r2t->sent;
+
+       task->hdr_len = sizeof(struct iscsi_data);
+
+       memset(hdr, 0, sizeof(struct iscsi_data));
+       hdr->ttt = r2t->ttt;
+       hdr->datasn = cpu_to_be32(r2t->datasn);
+       r2t->datasn++;
+       hdr->opcode = ISCSI_OP_SCSI_DATA_OUT;
+       hdr->lun = task->lun;
+       hdr->itt = task->hdr_itt;
+       hdr->exp_statsn = r2t->exp_statsn;
+       hdr->offset = cpu_to_be32(r2t->data_offset + r2t->sent);
+       if (left > conn->max_xmit_dlength) {
+               hton24(hdr->dlength, conn->max_xmit_dlength);
+               r2t->data_count = conn->max_xmit_dlength;
+               hdr->flags = 0;
+       } else {
+               hton24(hdr->dlength, left);
+               r2t->data_count = left;
+               hdr->flags = ISCSI_FLAG_CMD_FINAL;
+       }
+       conn->dataout_pdus_cnt++;
+}
+EXPORT_SYMBOL_GPL(iscsi_prep_data_out_pdu);
+
+static int iscsi_add_hdr(struct iscsi_task *task, unsigned len)
+{
+       unsigned exp_len = task->hdr_len + len;
+
+       if (exp_len > task->hdr_max) {
+               WARN_ON(1);
+               return -EINVAL;
+       }
+
+       WARN_ON(len & (ISCSI_PAD_LEN - 1)); /* caller must pad the AHS */
+       task->hdr_len = exp_len;
+       return 0;
+}
+
+/*
+ * make an extended cdb AHS
+ */
+static int iscsi_prep_ecdb_ahs(struct iscsi_task *task)
+{
+       struct scsi_cmnd *cmd = task->sc;
+       unsigned rlen, pad_len;
+       unsigned short ahslength;
+       struct iscsi_ecdb_ahdr *ecdb_ahdr;
+       int rc;
+
+       ecdb_ahdr = iscsi_next_hdr(task);
+       rlen = cmd->cmd_len - ISCSI_CDB_SIZE;
+
+       BUG_ON(rlen > sizeof(ecdb_ahdr->ecdb));
+       ahslength = rlen + sizeof(ecdb_ahdr->reserved);
+
+       pad_len = iscsi_padding(rlen);
+
+       rc = iscsi_add_hdr(task, sizeof(ecdb_ahdr->ahslength) +
+                          sizeof(ecdb_ahdr->ahstype) + ahslength + pad_len);
+       if (rc)
+               return rc;
+
+       if (pad_len)
+               memset(&ecdb_ahdr->ecdb[rlen], 0, pad_len);
+
+       ecdb_ahdr->ahslength = cpu_to_be16(ahslength);
+       ecdb_ahdr->ahstype = ISCSI_AHSTYPE_CDB;
+       ecdb_ahdr->reserved = 0;
+       memcpy(ecdb_ahdr->ecdb, cmd->cmnd + ISCSI_CDB_SIZE, rlen);
+
+       ISCSI_DBG_SESSION(task->conn->session,
+                         "iscsi_prep_ecdb_ahs: varlen_cdb_len %d "
+                         "rlen %d pad_len %d ahs_length %d iscsi_headers_size "
+                         "%u\n", cmd->cmd_len, rlen, pad_len, ahslength,
+                         task->hdr_len);
+       return 0;
+}
+
+static int iscsi_prep_bidi_ahs(struct iscsi_task *task)
+{
+       struct scsi_cmnd *sc = task->sc;
+       struct iscsi_rlength_ahdr *rlen_ahdr;
+       int rc;
+
+       rlen_ahdr = iscsi_next_hdr(task);
+       rc = iscsi_add_hdr(task, sizeof(*rlen_ahdr));
+       if (rc)
+               return rc;
+
+       rlen_ahdr->ahslength =
+               cpu_to_be16(sizeof(rlen_ahdr->read_length) +
+                                                 sizeof(rlen_ahdr->reserved));
+       rlen_ahdr->ahstype = ISCSI_AHSTYPE_RLENGTH;
+       rlen_ahdr->reserved = 0;
+       rlen_ahdr->read_length = cpu_to_be32(scsi_in(sc)->length);
+
+       ISCSI_DBG_SESSION(task->conn->session,
+                         "bidi-in rlen_ahdr->read_length(%d) "
+                         "rlen_ahdr->ahslength(%d)\n",
+                         be32_to_cpu(rlen_ahdr->read_length),
+                         be16_to_cpu(rlen_ahdr->ahslength));
+       return 0;
+}
+
+/**
+ * iscsi_check_tmf_restrictions - check if a task is affected by TMF
+ * @task: iscsi task
+ * @opcode: opcode to check for
+ *
+ * During TMF a task has to be checked if it's affected.
+ * All unrelated I/O can be passed through, but I/O to the
+ * affected LUN should be restricted.
+ * If 'fast_abort' is set we won't be sending any I/O to the
+ * affected LUN.
+ * Otherwise the target is waiting for all TTTs to be completed,
+ * so we have to send all outstanding Data-Out PDUs to the target.
+ */
+static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode)
+{
+       struct iscsi_conn *conn = task->conn;
+       struct iscsi_tm *tmf = &conn->tmhdr;
+       u64 hdr_lun;
+
+       if (conn->tmf_state == TMF_INITIAL)
+               return 0;
+
+       if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC)
+               return 0;
+
+       switch (ISCSI_TM_FUNC_VALUE(tmf)) {
+       case ISCSI_TM_FUNC_LOGICAL_UNIT_RESET:
+               /*
+                * Allow PDUs for unrelated LUNs
+                */
+               hdr_lun = scsilun_to_int(&tmf->lun);
+               if (hdr_lun != task->sc->device->lun)
+                       return 0;
+               /* fall through */
+       case ISCSI_TM_FUNC_TARGET_WARM_RESET:
+               /*
+                * Fail all SCSI cmd PDUs
+                */
+               if (opcode != ISCSI_OP_SCSI_DATA_OUT) {
+                       iscsi_conn_printk(KERN_INFO, conn,
+                                         "task [op %x/%x itt "
+                                         "0x%x/0x%x] "
+                                         "rejected.\n",
+                                         task->hdr->opcode, opcode,
+                                         task->itt, task->hdr_itt);
+                       return -EACCES;
+               }
+               /*
+                * And also all data-out PDUs in response to R2T
+                * if fast_abort is set.
+                */
+               if (conn->session->fast_abort) {
+                       iscsi_conn_printk(KERN_INFO, conn,
+                                         "task [op %x/%x itt "
+                                         "0x%x/0x%x] fast abort.\n",
+                                         task->hdr->opcode, opcode,
+                                         task->itt, task->hdr_itt);
+                       return -EACCES;
+               }
+               break;
+       case ISCSI_TM_FUNC_ABORT_TASK:
+               /*
+                * the caller has already checked if the task
+                * they want to abort was in the pending queue so if
+                * we are here the cmd pdu has gone out already, and
+                * we will only hit this for data-outs
+                */
+               if (opcode == ISCSI_OP_SCSI_DATA_OUT &&
+                   task->hdr_itt == tmf->rtt) {
+                       ISCSI_DBG_SESSION(conn->session,
+                                         "Preventing task %x/%x from sending "
+                                         "data-out due to abort task in "
+                                         "progress\n", task->itt,
+                                         task->hdr_itt);
+                       return -EACCES;
+               }
+               break;
+       }
+
+       return 0;
+}
+
+/**
+ * iscsi_prep_scsi_cmd_pdu - prep iscsi scsi cmd pdu
+ * @task: iscsi task
+ *
+ * Prep basic iSCSI PDU fields for a scsi cmd pdu. The LLD should set
+ * fields like dlength or final based on how much data it sends
+ */
+static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
+{
+       struct iscsi_conn *conn = task->conn;
+       struct iscsi_session *session = conn->session;
+       struct scsi_cmnd *sc = task->sc;
+       struct iscsi_scsi_req *hdr;
+       unsigned hdrlength, cmd_len, transfer_length;
+       itt_t itt;
+       int rc;
+
+       rc = iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_CMD);
+       if (rc)
+               return rc;
+
+       if (conn->session->tt->alloc_pdu) {
+               rc = conn->session->tt->alloc_pdu(task, ISCSI_OP_SCSI_CMD);
+               if (rc)
+                       return rc;
+       }
+       hdr = (struct iscsi_scsi_req *)task->hdr;
+       itt = hdr->itt;
+       memset(hdr, 0, sizeof(*hdr));
+
+       if (session->tt->parse_pdu_itt)
+               hdr->itt = task->hdr_itt = itt;
+       else
+               hdr->itt = task->hdr_itt = build_itt(task->itt,
+                                                    task->conn->session->age);
+       task->hdr_len = 0;
+       rc = iscsi_add_hdr(task, sizeof(*hdr));
+       if (rc)
+               return rc;
+       hdr->opcode = ISCSI_OP_SCSI_CMD;
+       hdr->flags = ISCSI_ATTR_SIMPLE;
+       int_to_scsilun(sc->device->lun, &hdr->lun);
+       task->lun = hdr->lun;
+       hdr->exp_statsn = cpu_to_be32(conn->exp_statsn);
+       cmd_len = sc->cmd_len;
+       if (cmd_len < ISCSI_CDB_SIZE)
+               memset(&hdr->cdb[cmd_len], 0, ISCSI_CDB_SIZE - cmd_len);
+       else if (cmd_len > ISCSI_CDB_SIZE) {
+               rc = iscsi_prep_ecdb_ahs(task);
+               if (rc)
+                       return rc;
+               cmd_len = ISCSI_CDB_SIZE;
+       }
+       memcpy(hdr->cdb, sc->cmnd, cmd_len);
+
+       task->imm_count = 0;
+       if (scsi_bidi_cmnd(sc)) {
+               hdr->flags |= ISCSI_FLAG_CMD_READ;
+               rc = iscsi_prep_bidi_ahs(task);
+               if (rc)
+                       return rc;
+       }
+
+       if (scsi_get_prot_op(sc) != SCSI_PROT_NORMAL)
+               task->protected = true;
+
+       transfer_length = scsi_transfer_length(sc);
+       hdr->data_length = cpu_to_be32(transfer_length);
+       if (sc->sc_data_direction == DMA_TO_DEVICE) {
+               struct iscsi_r2t_info *r2t = &task->unsol_r2t;
+
+               hdr->flags |= ISCSI_FLAG_CMD_WRITE;
+               /*
+                * Write counters:
+                *
+                *      imm_count       bytes to be sent right after
+                *                      SCSI PDU Header
+                *
+                *      unsol_count     bytes(as Data-Out) to be sent
+                *                      without R2T ack right after
+                *                      immediate data
+                *
+                *      r2t data_length bytes to be sent via R2T ack's
+                *
+                *      pad_count       bytes to be sent as zero-padding
+                */
+               memset(r2t, 0, sizeof(*r2t));
+
+               if (session->imm_data_en) {
+                       if (transfer_length >= session->first_burst)
+                               task->imm_count = min(session->first_burst,
+                                                       conn->max_xmit_dlength);
+                       else
+                               task->imm_count = min(transfer_length,
+                                                     conn->max_xmit_dlength);
+                       hton24(hdr->dlength, task->imm_count);
+               } else
+                       zero_data(hdr->dlength);
+
+               if (!session->initial_r2t_en) {
+                       r2t->data_length = min(session->first_burst,
+                                              transfer_length) -
+                                              task->imm_count;
+                       r2t->data_offset = task->imm_count;
+                       r2t->ttt = cpu_to_be32(ISCSI_RESERVED_TAG);
+                       r2t->exp_statsn = cpu_to_be32(conn->exp_statsn);
+               }
+
+               if (!task->unsol_r2t.data_length)
+                       /* No unsolicit Data-Out's */
+                       hdr->flags |= ISCSI_FLAG_CMD_FINAL;
+       } else {
+               hdr->flags |= ISCSI_FLAG_CMD_FINAL;
+               zero_data(hdr->dlength);
+
+               if (sc->sc_data_direction == DMA_FROM_DEVICE)
+                       hdr->flags |= ISCSI_FLAG_CMD_READ;
+       }
+
+       /* calculate size of additional header segments (AHSs) */
+       hdrlength = task->hdr_len - sizeof(*hdr);
+
+       WARN_ON(hdrlength & (ISCSI_PAD_LEN-1));
+       hdrlength /= ISCSI_PAD_LEN;
+
+       WARN_ON(hdrlength >= 256);
+       hdr->hlength = hdrlength & 0xFF;
+       hdr->cmdsn = task->cmdsn = cpu_to_be32(session->cmdsn);
+
+       if (session->tt->init_task && session->tt->init_task(task))
+               return -EIO;
+
+       task->state = ISCSI_TASK_RUNNING;
+       session->cmdsn++;
+
+       conn->scsicmd_pdus_cnt++;
+       ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
+                         "itt 0x%x len %d bidi_len %d cmdsn %d win %d]\n",
+                         scsi_bidi_cmnd(sc) ? "bidirectional" :
+                         sc->sc_data_direction == DMA_TO_DEVICE ?
+                         "write" : "read", conn->id, sc, sc->cmnd[0],
+                         task->itt, transfer_length,
+                         scsi_bidi_cmnd(sc) ? scsi_in(sc)->length : 0,
+                         session->cmdsn,
+                         session->max_cmdsn - session->exp_cmdsn + 1);
+       return 0;
+}
+
+/**
+ * iscsi_free_task - free a task
+ * @task: iscsi cmd task
+ *
+ * Must be called with session back_lock.
+ * This function returns the scsi command to scsi-ml or cleans
+ * up mgmt tasks then returns the task to the pool.
+ */
+static void iscsi_free_task(struct iscsi_task *task)
+{
+       struct iscsi_conn *conn = task->conn;
+       struct iscsi_session *session = conn->session;
+       struct scsi_cmnd *sc = task->sc;
+       int oldstate = task->state;
+
+       ISCSI_DBG_SESSION(session, "freeing task itt 0x%x state %d sc %p\n",
+                         task->itt, task->state, task->sc);
+
+       session->tt->cleanup_task(task);
+       task->state = ISCSI_TASK_FREE;
+       task->sc = NULL;
+       /*
+        * login task is preallocated so do not free
+        */
+       if (conn->login_task == task)
+               return;
+
+       kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
+
+       if (sc) {
+               /* SCSI eh reuses commands to verify us */
+               sc->SCp.ptr = NULL;
+               /*
+                * queue command may call this to free the task, so
+                * it will decide how to return sc to scsi-ml.
+                */
+               if (oldstate != ISCSI_TASK_REQUEUE_SCSIQ)
+                       sc->scsi_done(sc);
+       }
+}
+
+void __iscsi_get_task(struct iscsi_task *task)
+{
+       atomic_inc(&task->refcount);
+}
+EXPORT_SYMBOL_GPL(__iscsi_get_task);
+
+void __iscsi_put_task(struct iscsi_task *task)
+{
+       if (atomic_dec_and_test(&task->refcount))
+               iscsi_free_task(task);
+}
+EXPORT_SYMBOL_GPL(__iscsi_put_task);
+
+void iscsi_put_task(struct iscsi_task *task)
+{
+       struct iscsi_session *session = task->conn->session;
+
+       /* regular RX path uses back_lock */
+       spin_lock_bh(&session->back_lock);
+       __iscsi_put_task(task);
+       spin_unlock_bh(&session->back_lock);
+}
+EXPORT_SYMBOL_GPL(iscsi_put_task);
+
+/**
+ * iscsi_complete_task - finish a task
+ * @task: iscsi cmd task
+ * @state: state to complete task with
+ *
+ * Must be called with session back_lock.
+ */
+static void iscsi_complete_task(struct iscsi_task *task, int state)
+{
+       struct iscsi_conn *conn = task->conn;
+
+       ISCSI_DBG_SESSION(conn->session,
+                         "complete task itt 0x%x state %d sc %p\n",
+                         task->itt, task->state, task->sc);
+       if (task->state == ISCSI_TASK_COMPLETED ||
+           task->state == ISCSI_TASK_ABRT_TMF ||
+           task->state == ISCSI_TASK_ABRT_SESS_RECOV ||
+           task->state == ISCSI_TASK_REQUEUE_SCSIQ)
+               return;
+       WARN_ON_ONCE(task->state == ISCSI_TASK_FREE);
+       task->state = state;
+
+       if (!list_empty(&task->running))
+               list_del_init(&task->running);
+
+       if (conn->task == task)
+               conn->task = NULL;
+
+       if (conn->ping_task == task)
+               conn->ping_task = NULL;
+
+       /* release get from queueing */
+       __iscsi_put_task(task);
+}
+
+/**
+ * iscsi_complete_scsi_task - finish scsi task normally
+ * @task: iscsi task for scsi cmd
+ * @exp_cmdsn: expected cmd sn in cpu format
+ * @max_cmdsn: max cmd sn in cpu format
+ *
+ * This is used when drivers do not need or cannot perform
+ * lower level pdu processing.
+ *
+ * Called with session back_lock
+ */
+void iscsi_complete_scsi_task(struct iscsi_task *task,
+                             uint32_t exp_cmdsn, uint32_t max_cmdsn)
+{
+       struct iscsi_conn *conn = task->conn;
+
+       ISCSI_DBG_SESSION(conn->session, "[itt 0x%x]\n", task->itt);
+
+       conn->last_recv = jiffies;
+       __iscsi_update_cmdsn(conn->session, exp_cmdsn, max_cmdsn);
+       iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
+}
+EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
+
+
+/*
+ * session back_lock must be held and if not called for a task that is
+ * still pending or from the xmit thread, then xmit thread must
+ * be suspended.
+ */
+static void fail_scsi_task(struct iscsi_task *task, int err)
+{
+       struct iscsi_conn *conn = task->conn;
+       struct scsi_cmnd *sc;
+       int state;
+
+       /*
+        * if a command completes and we get a successful tmf response
+        * we will hit this because the scsi eh abort code does not take
+        * a ref to the task.
+        */
+       sc = task->sc;
+       if (!sc)
+               return;
+
+       if (task->state == ISCSI_TASK_PENDING) {
+               /*
+                * cmd never made it to the xmit thread, so we should not count
+                * the cmd in the sequencing
+                */
+               conn->session->queued_cmdsn--;
+               /* it was never sent so just complete like normal */
+               state = ISCSI_TASK_COMPLETED;
+       } else if (err == DID_TRANSPORT_DISRUPTED)
+               state = ISCSI_TASK_ABRT_SESS_RECOV;
+       else
+               state = ISCSI_TASK_ABRT_TMF;
+
+       sc->result = err << 16;
+       if (!scsi_bidi_cmnd(sc))
+               scsi_set_resid(sc, scsi_bufflen(sc));
+       else {
+               scsi_out(sc)->resid = scsi_out(sc)->length;
+               scsi_in(sc)->resid = scsi_in(sc)->length;
+       }
+
+       /* regular RX path uses back_lock */
+       spin_lock_bh(&conn->session->back_lock);
+       iscsi_complete_task(task, state);
+       spin_unlock_bh(&conn->session->back_lock);
+}
+
+static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
+                               struct iscsi_task *task)
+{
+       struct iscsi_session *session = conn->session;
+       struct iscsi_hdr *hdr = task->hdr;
+       struct iscsi_nopout *nop = (struct iscsi_nopout *)hdr;
+       uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
+
+       if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
+               return -ENOTCONN;
+
+       if (opcode != ISCSI_OP_LOGIN && opcode != ISCSI_OP_TEXT)
+               nop->exp_statsn = cpu_to_be32(conn->exp_statsn);
+       /*
+        * pre-format CmdSN for outgoing PDU.
+        */
+       nop->cmdsn = cpu_to_be32(session->cmdsn);
+       if (hdr->itt != RESERVED_ITT) {
+               /*
+                * TODO: We always use immediate for normal session pdus.
+                * If we start to send tmfs or nops as non-immediate then
+                * we should start checking the cmdsn numbers for mgmt tasks.
+                *
+                * During discovery sessions iscsid sends TEXT as non immediate,
+                * but we always only send one PDU at a time.
+                */
+               if (conn->c_stage == ISCSI_CONN_STARTED &&
+                   !(hdr->opcode & ISCSI_OP_IMMEDIATE)) {
+                       session->queued_cmdsn++;
+                       session->cmdsn++;
+               }
+       }
+
+       if (session->tt->init_task && session->tt->init_task(task))
+               return -EIO;
+
+       if ((hdr->opcode & ISCSI_OPCODE_MASK) == ISCSI_OP_LOGOUT)
+               session->state = ISCSI_STATE_LOGGING_OUT;
+
+       task->state = ISCSI_TASK_RUNNING;
+       ISCSI_DBG_SESSION(session, "mgmtpdu [op 0x%x hdr->itt 0x%x "
+                         "datalen %d]\n", hdr->opcode & ISCSI_OPCODE_MASK,
+                         hdr->itt, task->data_count);
+       return 0;
+}
+
+static struct iscsi_task *
+__iscsi_conn_send_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
+                     char *data, uint32_t data_size)
+{
+       struct iscsi_session *session = conn->session;
+       struct iscsi_host *ihost = shost_priv(session->host);
+       uint8_t opcode = hdr->opcode & ISCSI_OPCODE_MASK;
+       struct iscsi_task *task;
+       itt_t itt;
+
+       if (session->state == ISCSI_STATE_TERMINATE)
+               return NULL;
+
+       if (opcode == ISCSI_OP_LOGIN || opcode == ISCSI_OP_TEXT) {
+               /*
+                * Login and Text are sent serially, in
+                * request-followed-by-response sequence.
+                * Same task can be used. Same ITT must be used.
+                * Note that login_task is preallocated at conn_create().
+                */
+               if (conn->login_task->state != ISCSI_TASK_FREE) {
+                       iscsi_conn_printk(KERN_ERR, conn, "Login/Text in "
+                                         "progress. Cannot start new task.\n");
+                       return NULL;
+               }
+
+               if (data_size > ISCSI_DEF_MAX_RECV_SEG_LEN) {
+                       iscsi_conn_printk(KERN_ERR, conn, "Invalid buffer len of %u for login task. Max len is %u\n", data_size, ISCSI_DEF_MAX_RECV_SEG_LEN);
+                       return NULL;
+               }
+
+               task = conn->login_task;
+       } else {
+               if (session->state != ISCSI_STATE_LOGGED_IN)
+                       return NULL;
+
+               if (data_size != 0) {
+                       iscsi_conn_printk(KERN_ERR, conn, "Can not send data buffer of len %u for op 0x%x\n", data_size, opcode);
+                       return NULL;
+               }
+
+               BUG_ON(conn->c_stage == ISCSI_CONN_INITIAL_STAGE);
+               BUG_ON(conn->c_stage == ISCSI_CONN_STOPPED);
+
+               if (!kfifo_out(&session->cmdpool.queue,
+                                (void*)&task, sizeof(void*)))
+                       return NULL;
+       }
+       /*
+        * released in complete pdu for task we expect a response for, and
+        * released by the lld when it has transmitted the task for
+        * pdus we do not expect a response for.
+        */
+       atomic_set(&task->refcount, 1);
+       task->conn = conn;
+       task->sc = NULL;
+       INIT_LIST_HEAD(&task->running);
+       task->state = ISCSI_TASK_PENDING;
+
+       if (data_size) {
+               memcpy(task->data, data, data_size);
+               task->data_count = data_size;
+       } else
+               task->data_count = 0;
+
+       if (conn->session->tt->alloc_pdu) {
+               if (conn->session->tt->alloc_pdu(task, hdr->opcode)) {
+                       iscsi_conn_printk(KERN_ERR, conn, "Could not allocate "
+                                        "pdu for mgmt task.\n");
+                       goto free_task;
+               }
+       }
+
+       itt = task->hdr->itt;
+       task->hdr_len = sizeof(struct iscsi_hdr);
+       memcpy(task->hdr, hdr, sizeof(struct iscsi_hdr));
+
+       if (hdr->itt != RESERVED_ITT) {
+               if (session->tt->parse_pdu_itt)
+                       task->hdr->itt = itt;
+               else
+                       task->hdr->itt = build_itt(task->itt,
+                                                  task->conn->session->age);
+       }
+
+       if (!ihost->workq) {
+               if (iscsi_prep_mgmt_task(conn, task))
+                       goto free_task;
+
+               if (session->tt->xmit_task(task))
+                       goto free_task;
+       } else {
+               list_add_tail(&task->running, &conn->mgmtqueue);
+               iscsi_conn_queue_work(conn);
+       }
+
+       return task;
+
+free_task:
+       /* regular RX path uses back_lock */
+       spin_lock_bh(&session->back_lock);
+       __iscsi_put_task(task);
+       spin_unlock_bh(&session->back_lock);
+       return NULL;
+}
+
+int iscsi_conn_send_pdu(struct iscsi_cls_conn *cls_conn, struct iscsi_hdr *hdr,
+                       char *data, uint32_t data_size)
+{
+       struct iscsi_conn *conn = cls_conn->dd_data;
+       struct iscsi_session *session = conn->session;
+       int err = 0;
+
+       spin_lock_bh(&session->frwd_lock);
+       if (!__iscsi_conn_send_pdu(conn, hdr, data, data_size))
+               err = -EPERM;
+       spin_unlock_bh(&session->frwd_lock);
+       return err;
+}
+EXPORT_SYMBOL_GPL(iscsi_conn_send_pdu);
+
+/**
+ * iscsi_cmd_rsp - SCSI Command Response processing
+ * @conn: iscsi connection
+ * @hdr: iscsi header
+ * @task: scsi command task
+ * @data: cmd data buffer
+ * @datalen: len of buffer
+ *
+ * iscsi_cmd_rsp sets up the scsi_cmnd fields based on the PDU and
+ * then completes the command and task.
+ **/
+static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
+                              struct iscsi_task *task, char *data,
+                              int datalen)
+{
+       struct iscsi_scsi_rsp *rhdr = (struct iscsi_scsi_rsp *)hdr;
+       struct iscsi_session *session = conn->session;
+       struct scsi_cmnd *sc = task->sc;
+
+       iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
+       conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
+
+       sc->result = (DID_OK << 16) | rhdr->cmd_status;
+
+       if (task->protected) {
+               sector_t sector;
+               u8 ascq;
+
+               /**
+                * Transports that didn't implement check_protection
+                * callback but still published T10-PI support to scsi-mid
+                * deserve this BUG_ON.
+                **/
+               BUG_ON(!session->tt->check_protection);
+
+               ascq = session->tt->check_protection(task, &sector);
+               if (ascq) {
+                       sc->result = DRIVER_SENSE << 24 |
+                                    SAM_STAT_CHECK_CONDITION;
+                       scsi_build_sense_buffer(1, sc->sense_buffer,
+                                               ILLEGAL_REQUEST, 0x10, ascq);
+                       sc->sense_buffer[7] = 0xc; /* Additional sense length */
+                       sc->sense_buffer[8] = 0;   /* Information desc type */
+                       sc->sense_buffer[9] = 0xa; /* Additional desc length */
+                       sc->sense_buffer[10] = 0x80; /* Validity bit */
+
+                       put_unaligned_be64(sector, &sc->sense_buffer[12]);
+                       goto out;
+               }
+       }
+
+       if (rhdr->response != ISCSI_STATUS_CMD_COMPLETED) {
+               sc->result = DID_ERROR << 16;
+               goto out;
+       }
+
+       if (rhdr->cmd_status == SAM_STAT_CHECK_CONDITION) {
+               uint16_t senselen;
+
+               if (datalen < 2) {
+invalid_datalen:
+                       iscsi_conn_printk(KERN_ERR,  conn,
+                                        "Got CHECK_CONDITION but invalid data "
+                                        "buffer size of %d\n", datalen);
+                       sc->result = DID_BAD_TARGET << 16;
+                       goto out;
+               }
+
+               senselen = get_unaligned_be16(data);
+               if (datalen < senselen)
+                       goto invalid_datalen;
+
+               memcpy(sc->sense_buffer, data + 2,
+                      min_t(uint16_t, senselen, SCSI_SENSE_BUFFERSIZE));
+               ISCSI_DBG_SESSION(session, "copied %d bytes of sense\n",
+                                 min_t(uint16_t, senselen,
+                                 SCSI_SENSE_BUFFERSIZE));
+       }
+
+       if (rhdr->flags & (ISCSI_FLAG_CMD_BIDI_UNDERFLOW |
+                          ISCSI_FLAG_CMD_BIDI_OVERFLOW)) {
+               int res_count = be32_to_cpu(rhdr->bi_residual_count);
+
+               if (scsi_bidi_cmnd(sc) && res_count > 0 &&
+                               (rhdr->flags & ISCSI_FLAG_CMD_BIDI_OVERFLOW ||
+                                res_count <= scsi_in(sc)->length))
+                       scsi_in(sc)->resid = res_count;
+               else
+                       sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
+       }
+
+       if (rhdr->flags & (ISCSI_FLAG_CMD_UNDERFLOW |
+                          ISCSI_FLAG_CMD_OVERFLOW)) {
+               int res_count = be32_to_cpu(rhdr->residual_count);
+
+               if (res_count > 0 &&
+                   (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
+                    res_count <= scsi_bufflen(sc)))
+                       /* write side for bidi or uni-io set_resid */
+                       scsi_set_resid(sc, res_count);
+               else
+                       sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
+       }
+out:
+       ISCSI_DBG_SESSION(session, "cmd rsp done [sc %p res %d itt 0x%x]\n",
+                         sc, sc->result, task->itt);
+       conn->scsirsp_pdus_cnt++;
+       iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
+}
+
+/**
+ * iscsi_data_in_rsp - SCSI Data-In Response processing
+ * @conn: iscsi connection
+ * @hdr:  iscsi pdu
+ * @task: scsi command task
+ **/
+static void
+iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
+                 struct iscsi_task *task)
+{
+       struct iscsi_data_rsp *rhdr = (struct iscsi_data_rsp *)hdr;
+       struct scsi_cmnd *sc = task->sc;
+
+       if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
+               return;
+
+       iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
+       sc->result = (DID_OK << 16) | rhdr->cmd_status;
+       conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
+       if (rhdr->flags & (ISCSI_FLAG_DATA_UNDERFLOW |
+                          ISCSI_FLAG_DATA_OVERFLOW)) {
+               int res_count = be32_to_cpu(rhdr->residual_count);
+
+               if (res_count > 0 &&
+                   (rhdr->flags & ISCSI_FLAG_CMD_OVERFLOW ||
+                    res_count <= scsi_in(sc)->length))
+                       scsi_in(sc)->resid = res_count;
+               else
+                       sc->result = (DID_BAD_TARGET << 16) | rhdr->cmd_status;
+       }
+
+       ISCSI_DBG_SESSION(conn->session, "data in with status done "
+                         "[sc %p res %d itt 0x%x]\n",
+                         sc, sc->result, task->itt);
+       conn->scsirsp_pdus_cnt++;
+       iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
+}
+
+static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
+{
+       struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr;
+
+       conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
+       conn->tmfrsp_pdus_cnt++;
+
+       if (conn->tmf_state != TMF_QUEUED)
+               return;
+
+       if (tmf->response == ISCSI_TMF_RSP_COMPLETE)
+               conn->tmf_state = TMF_SUCCESS;
+       else if (tmf->response == ISCSI_TMF_RSP_NO_TASK)
+               conn->tmf_state = TMF_NOT_FOUND;
+       else
+               conn->tmf_state = TMF_FAILED;
+       wake_up(&conn->ehwait);
+}
+
+static void iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr)
+{
+        struct iscsi_nopout hdr;
+       struct iscsi_task *task;
+
+       if (!rhdr && conn->ping_task)
+               return;
+
+       memset(&hdr, 0, sizeof(struct iscsi_nopout));
+       hdr.opcode = ISCSI_OP_NOOP_OUT | ISCSI_OP_IMMEDIATE;
+       hdr.flags = ISCSI_FLAG_CMD_FINAL;
+
+       if (rhdr) {
+               hdr.lun = rhdr->lun;
+               hdr.ttt = rhdr->ttt;
+               hdr.itt = RESERVED_ITT;
+       } else
+               hdr.ttt = RESERVED_ITT;
+
+       task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)&hdr, NULL, 0);
+       if (!task)
+               iscsi_conn_printk(KERN_ERR, conn, "Could not send nopout\n");
+       else if (!rhdr) {
+               /* only track our nops */
+               conn->ping_task = task;
+               conn->last_ping = jiffies;
+       }
+}
+
+static int iscsi_nop_out_rsp(struct iscsi_task *task,
+                            struct iscsi_nopin *nop, char *data, int datalen)
+{
+       struct iscsi_conn *conn = task->conn;
+       int rc = 0;
+
+       if (conn->ping_task != task) {
+               /*
+                * If this is not in response to one of our
+                * nops then it must be from userspace.
+                */
+               if (iscsi_recv_pdu(conn->cls_conn, (struct iscsi_hdr *)nop,
+                                  data, datalen))
+                       rc = ISCSI_ERR_CONN_FAILED;
+       } else
+               mod_timer(&conn->transport_timer, jiffies + conn->recv_timeout);
+       iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
+       return rc;
+}
+
+static int iscsi_handle_reject(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
+                              char *data, int datalen)
+{
+       struct iscsi_reject *reject = (struct iscsi_reject *)hdr;
+       struct iscsi_hdr rejected_pdu;
+       int opcode, rc = 0;
+
+       conn->exp_statsn = be32_to_cpu(reject->statsn) + 1;
+
+       if (ntoh24(reject->dlength) > datalen ||
+           ntoh24(reject->dlength) < sizeof(struct iscsi_hdr)) {
+               iscsi_conn_printk(KERN_ERR, conn, "Cannot handle rejected "
+                                 "pdu. Invalid data length (pdu dlength "
+                                 "%u, datalen %d\n", ntoh24(reject->dlength),
+                                 datalen);
+               return ISCSI_ERR_PROTO;
+       }
+       memcpy(&rejected_pdu, data, sizeof(struct iscsi_hdr));
+       opcode = rejected_pdu.opcode & ISCSI_OPCODE_MASK;
+
+       switch (reject->reason) {
+       case ISCSI_REASON_DATA_DIGEST_ERROR:
+               iscsi_conn_printk(KERN_ERR, conn,
+                                 "pdu (op 0x%x itt 0x%x) rejected "
+                                 "due to DataDigest error.\n",
+                                 opcode, rejected_pdu.itt);
+               break;
+       case ISCSI_REASON_IMM_CMD_REJECT:
+               iscsi_conn_printk(KERN_ERR, conn,
+                                 "pdu (op 0x%x itt 0x%x) rejected. Too many "
+                                 "immediate commands.\n",
+                                 opcode, rejected_pdu.itt);
+               /*
+                * We only send one TMF at a time so if the target could not
+                * handle it, then it should get fixed (RFC mandates that
+                * a target can handle one immediate TMF per conn).
+                *
+                * For nops-outs, we could have sent more than one if
+                * the target is sending us lots of nop-ins
+                */
+               if (opcode != ISCSI_OP_NOOP_OUT)
+                       return 0;
+
+                if (rejected_pdu.itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
+                       /*
+                        * nop-out in response to target's nop-out rejected.
+                        * Just resend.
+                        */
+                       /* In RX path we are under back lock */
+                       spin_unlock(&conn->session->back_lock);
+                       spin_lock(&conn->session->frwd_lock);
+                       iscsi_send_nopout(conn,
+                                         (struct iscsi_nopin*)&rejected_pdu);
+                       spin_unlock(&conn->session->frwd_lock);
+                       spin_lock(&conn->session->back_lock);
+               } else {
+                       struct iscsi_task *task;
+                       /*
+                        * Our nop as ping got dropped. We know the target
+                        * and transport are ok so just clean up
+                        */
+                       task = iscsi_itt_to_task(conn, rejected_pdu.itt);
+                       if (!task) {
+                               iscsi_conn_printk(KERN_ERR, conn,
+                                                "Invalid pdu reject. Could "
+                                                "not lookup rejected task.\n");
+                               rc = ISCSI_ERR_BAD_ITT;
+                       } else
+                               rc = iscsi_nop_out_rsp(task,
+                                       (struct iscsi_nopin*)&rejected_pdu,
+                                       NULL, 0);
+               }
+               break;
+       default:
+               iscsi_conn_printk(KERN_ERR, conn,
+                                 "pdu (op 0x%x itt 0x%x) rejected. Reason "
+                                 "code 0x%x\n", rejected_pdu.opcode,
+                                 rejected_pdu.itt, reject->reason);
+               break;
+       }
+       return rc;
+}
+
+/**
+ * iscsi_itt_to_task - look up task by itt
+ * @conn: iscsi connection
+ * @itt: itt
+ *
+ * This should be used for mgmt tasks like login and nops, or if
+ * the LDD's itt space does not include the session age.
+ *
+ * The session back_lock must be held.
+ */
+struct iscsi_task *iscsi_itt_to_task(struct iscsi_conn *conn, itt_t itt)
+{
+       struct iscsi_session *session = conn->session;
+       int i;
+
+       if (itt == RESERVED_ITT)
+               return NULL;
+
+       if (session->tt->parse_pdu_itt)
+               session->tt->parse_pdu_itt(conn, itt, &i, NULL);
+       else
+               i = get_itt(itt);
+       if (i >= session->cmds_max)
+               return NULL;
+
+       return session->cmds[i];
+}
+EXPORT_SYMBOL_GPL(iscsi_itt_to_task);
+
+/**
+ * __iscsi_complete_pdu - complete pdu
+ * @conn: iscsi conn
+ * @hdr: iscsi header
+ * @data: data buffer
+ * @datalen: len of data buffer
+ *
+ * Completes pdu processing by freeing any resources allocated at
+ * queuecommand or send generic. session back_lock must be held and verify
+ * itt must have been called.
+ */
+int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
+                        char *data, int datalen)
+{
+       struct iscsi_session *session = conn->session;
+       int opcode = hdr->opcode & ISCSI_OPCODE_MASK, rc = 0;
+       struct iscsi_task *task;
+       uint32_t itt;
+
+       conn->last_recv = jiffies;
+       rc = iscsi_verify_itt(conn, hdr->itt);
+       if (rc)
+               return rc;
+
+       if (hdr->itt != RESERVED_ITT)
+               itt = get_itt(hdr->itt);
+       else
+               itt = ~0U;
+
+       ISCSI_DBG_SESSION(session, "[op 0x%x cid %d itt 0x%x len %d]\n",
+                         opcode, conn->id, itt, datalen);
+
+       if (itt == ~0U) {
+               iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
+
+               switch(opcode) {
+               case ISCSI_OP_NOOP_IN:
+                       if (datalen) {
+                               rc = ISCSI_ERR_PROTO;
+                               break;
+                       }
+
+                       if (hdr->ttt == cpu_to_be32(ISCSI_RESERVED_TAG))
+                               break;
+
+                       /* In RX path we are under back lock */
+                       spin_unlock(&session->back_lock);
+                       spin_lock(&session->frwd_lock);
+                       iscsi_send_nopout(conn, (struct iscsi_nopin*)hdr);
+                       spin_unlock(&session->frwd_lock);
+                       spin_lock(&session->back_lock);
+                       break;
+               case ISCSI_OP_REJECT:
+                       rc = iscsi_handle_reject(conn, hdr, data, datalen);
+                       break;
+               case ISCSI_OP_ASYNC_EVENT:
+                       conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
+                       if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
+                               rc = ISCSI_ERR_CONN_FAILED;
+                       break;
+               default:
+                       rc = ISCSI_ERR_BAD_OPCODE;
+                       break;
+               }
+               goto out;
+       }
+
+       switch(opcode) {
+       case ISCSI_OP_SCSI_CMD_RSP:
+       case ISCSI_OP_SCSI_DATA_IN:
+               task = iscsi_itt_to_ctask(conn, hdr->itt);
+               if (!task)
+                       return ISCSI_ERR_BAD_ITT;
+               task->last_xfer = jiffies;
+               break;
+       case ISCSI_OP_R2T:
+               /*
+                * LLD handles R2Ts if they need to.
+                */
+               return 0;
+       case ISCSI_OP_LOGOUT_RSP:
+       case ISCSI_OP_LOGIN_RSP:
+       case ISCSI_OP_TEXT_RSP:
+       case ISCSI_OP_SCSI_TMFUNC_RSP:
+       case ISCSI_OP_NOOP_IN:
+               task = iscsi_itt_to_task(conn, hdr->itt);
+               if (!task)
+                       return ISCSI_ERR_BAD_ITT;
+               break;
+       default:
+               return ISCSI_ERR_BAD_OPCODE;
+       }
+
+       switch(opcode) {
+       case ISCSI_OP_SCSI_CMD_RSP:
+               iscsi_scsi_cmd_rsp(conn, hdr, task, data, datalen);
+               break;
+       case ISCSI_OP_SCSI_DATA_IN:
+               iscsi_data_in_rsp(conn, hdr, task);
+               break;
+       case ISCSI_OP_LOGOUT_RSP:
+               iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
+               if (datalen) {
+                       rc = ISCSI_ERR_PROTO;
+                       break;
+               }
+               conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
+               goto recv_pdu;
+       case ISCSI_OP_LOGIN_RSP:
+       case ISCSI_OP_TEXT_RSP:
+               iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
+               /*
+                * login related PDU's exp_statsn is handled in
+                * userspace
+                */
+               goto recv_pdu;
+       case ISCSI_OP_SCSI_TMFUNC_RSP:
+               iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
+               if (datalen) {
+                       rc = ISCSI_ERR_PROTO;
+                       break;
+               }
+
+               iscsi_tmf_rsp(conn, hdr);
+               iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
+               break;
+       case ISCSI_OP_NOOP_IN:
+               iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
+               if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
+                       rc = ISCSI_ERR_PROTO;
+                       break;
+               }
+               conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1;
+
+               rc = iscsi_nop_out_rsp(task, (struct iscsi_nopin*)hdr,
+                                      data, datalen);
+               break;
+       default:
+               rc = ISCSI_ERR_BAD_OPCODE;
+               break;
+       }
+
+out:
+       return rc;
+recv_pdu:
+       if (iscsi_recv_pdu(conn->cls_conn, hdr, data, datalen))
+               rc = ISCSI_ERR_CONN_FAILED;
+       iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
+       return rc;
+}
+EXPORT_SYMBOL_GPL(__iscsi_complete_pdu);
+
+int iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
+                      char *data, int datalen)
+{
+       int rc;
+
+       spin_lock(&conn->session->back_lock);
+       rc = __iscsi_complete_pdu(conn, hdr, data, datalen);
+       spin_unlock(&conn->session->back_lock);
+       return rc;
+}
+EXPORT_SYMBOL_GPL(iscsi_complete_pdu);
+
+int iscsi_verify_itt(struct iscsi_conn *conn, itt_t itt)
+{
+       struct iscsi_session *session = conn->session;
+       int age = 0, i = 0;
+
+       if (itt == RESERVED_ITT)
+               return 0;
+
+       if (session->tt->parse_pdu_itt)
+               session->tt->parse_pdu_itt(conn, itt, &i, &age);
+       else {
+               i = get_itt(itt);
+               age = ((__force u32)itt >> ISCSI_AGE_SHIFT) & ISCSI_AGE_MASK;
+       }
+
+       if (age != session->age) {
+               iscsi_conn_printk(KERN_ERR, conn,
+                                 "received itt %x expected session age (%x)\n",
+                                 (__force u32)itt, session->age);
+               return ISCSI_ERR_BAD_ITT;
+       }
+
+       if (i >= session->cmds_max) {
+               iscsi_conn_printk(KERN_ERR, conn,
+                                 "received invalid itt index %u (max cmds "
+                                  "%u.\n", i, session->cmds_max);
+               return ISCSI_ERR_BAD_ITT;
+       }
+       return 0;
+}
+EXPORT_SYMBOL_GPL(iscsi_verify_itt);
+
+/**
+ * iscsi_itt_to_ctask - look up ctask by itt
+ * @conn: iscsi connection
+ * @itt: itt
+ *
+ * This should be used for cmd tasks.
+ *
+ * The session back_lock must be held.
+ */
+struct iscsi_task *iscsi_itt_to_ctask(struct iscsi_conn *conn, itt_t itt)
+{
+       struct iscsi_task *task;
+
+       if (iscsi_verify_itt(conn, itt))
+               return NULL;
+
+       task = iscsi_itt_to_task(conn, itt);
+       if (!task || !task->sc)
+               return NULL;
+
+       if (task->sc->SCp.phase != conn->session->age) {
+               iscsi_session_printk(KERN_ERR, conn->session,
+                                 "task's session age %d, expected %d\n",
+                                 task->sc->SCp.phase, conn->session->age);
+               return NULL;
+       }
+
+       return task;
+}
+EXPORT_SYMBOL_GPL(iscsi_itt_to_ctask);
+
+void iscsi_session_failure(struct iscsi_session *session,
+                          enum iscsi_err err)
+{
+       struct iscsi_conn *conn;
+       struct device *dev;
+
+       spin_lock_bh(&session->frwd_lock);
+       conn = session->leadconn;
+       if (session->state == ISCSI_STATE_TERMINATE || !conn) {
+               spin_unlock_bh(&session->frwd_lock);
+               return;
+       }
+
+       dev = get_device(&conn->cls_conn->dev);
+       spin_unlock_bh(&session->frwd_lock);
+       if (!dev)
+               return;
+       /*
+        * if the host is being removed bypass the connection
+        * recovery initialization because we are going to kill
+        * the session.
+        */
+       if (err == ISCSI_ERR_INVALID_HOST)
+               iscsi_conn_error_event(conn->cls_conn, err);
+       else
+               iscsi_conn_failure(conn, err);
+       put_device(dev);
+}
+EXPORT_SYMBOL_GPL(iscsi_session_failure);
+
+void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err err)
+{
+       struct iscsi_session *session = conn->session;
+
+       spin_lock_bh(&session->frwd_lock);
+       if (session->state == ISCSI_STATE_FAILED) {
+               spin_unlock_bh(&session->frwd_lock);
+               return;
+       }
+
+       if (conn->stop_stage == 0)
+               session->state = ISCSI_STATE_FAILED;
+       spin_unlock_bh(&session->frwd_lock);
+
+       set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
+       set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
+       iscsi_conn_error_event(conn->cls_conn, err);
+}
+EXPORT_SYMBOL_GPL(iscsi_conn_failure);
+
+static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
+{
+       struct iscsi_session *session = conn->session;
+
+       /*
+        * Check for iSCSI window and take care of CmdSN wrap-around
+        */
+       if (!iscsi_sna_lte(session->queued_cmdsn, session->max_cmdsn)) {
+               ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
+                                 "%u MaxCmdSN %u CmdSN %u/%u\n",
+                                 session->exp_cmdsn, session->max_cmdsn,
+                                 session->cmdsn, session->queued_cmdsn);
+               return -ENOSPC;
+       }
+       return 0;
+}
+
+static int iscsi_xmit_task(struct iscsi_conn *conn)
+{
+       struct iscsi_task *task = conn->task;
+       int rc;
+
+       if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx))
+               return -ENODATA;
+
+       __iscsi_get_task(task);
+       spin_unlock_bh(&conn->session->frwd_lock);
+       rc = conn->session->tt->xmit_task(task);
+       spin_lock_bh(&conn->session->frwd_lock);
+       if (!rc) {
+               /* done with this task */
+               task->last_xfer = jiffies;
+               conn->task = NULL;
+       }
+       /* regular RX path uses back_lock */
+       spin_lock(&conn->session->back_lock);
+       __iscsi_put_task(task);
+       spin_unlock(&conn->session->back_lock);
+       return rc;
+}
+
+/**
+ * iscsi_requeue_task - requeue task to run from session workqueue
+ * @task: task to requeue
+ *
+ * LLDs that need to run a task from the session workqueue should call
+ * this. The session frwd_lock must be held. This should only be called
+ * by software drivers.
+ */
+void iscsi_requeue_task(struct iscsi_task *task)
+{
+       struct iscsi_conn *conn = task->conn;
+
+       /*
+        * this may be on the requeue list already if the xmit_task callout
+        * is handling the r2ts while we are adding new ones
+        */
+       if (list_empty(&task->running))
+               list_add_tail(&task->running, &conn->requeue);
+       iscsi_conn_queue_work(conn);
+}
+EXPORT_SYMBOL_GPL(iscsi_requeue_task);
+
+/**
+ * iscsi_data_xmit - xmit any command into the scheduled connection
+ * @conn: iscsi connection
+ *
+ * Notes:
+ *     The function can return -EAGAIN in which case the caller must
+ *     re-schedule it again later or recover. '0' return code means
+ *     successful xmit.
+ **/
+static int iscsi_data_xmit(struct iscsi_conn *conn)
+{
+       struct iscsi_task *task;
+       int rc = 0;
+
+       spin_lock_bh(&conn->session->frwd_lock);
+       if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
+               ISCSI_DBG_SESSION(conn->session, "Tx suspended!\n");
+               spin_unlock_bh(&conn->session->frwd_lock);
+               return -ENODATA;
+       }
+
+       if (conn->task) {
+               rc = iscsi_xmit_task(conn);
+               if (rc)
+                       goto done;
+       }
+
+       /*
+        * process mgmt pdus like nops before commands since we should
+        * only have one nop-out as a ping from us and targets should not
+        * overflow us with nop-ins
+        */
+check_mgmt:
+       while (!list_empty(&conn->mgmtqueue)) {
+               conn->task = list_entry(conn->mgmtqueue.next,
+                                        struct iscsi_task, running);
+               list_del_init(&conn->task->running);
+               if (iscsi_prep_mgmt_task(conn, conn->task)) {
+                       /* regular RX path uses back_lock */
+                       spin_lock_bh(&conn->session->back_lock);
+                       __iscsi_put_task(conn->task);
+                       spin_unlock_bh(&conn->session->back_lock);
+                       conn->task = NULL;
+                       continue;
+               }
+               rc = iscsi_xmit_task(conn);
+               if (rc)
+                       goto done;
+       }
+
+       /* process pending command queue */
+       while (!list_empty(&conn->cmdqueue)) {
+               conn->task = list_entry(conn->cmdqueue.next, struct iscsi_task,
+                                       running);
+               list_del_init(&conn->task->running);
+               if (conn->session->state == ISCSI_STATE_LOGGING_OUT) {
+                       fail_scsi_task(conn->task, DID_IMM_RETRY);
+                       continue;
+               }
+               rc = iscsi_prep_scsi_cmd_pdu(conn->task);
+               if (rc) {
+                       if (rc == -ENOMEM || rc == -EACCES) {
+                               list_add_tail(&conn->task->running,
+                                             &conn->cmdqueue);
+                               conn->task = NULL;
+                               goto done;
+                       } else
+                               fail_scsi_task(conn->task, DID_ABORT);
+                       continue;
+               }
+               rc = iscsi_xmit_task(conn);
+               if (rc)
+                       goto done;
+               /*
+                * we could continuously get new task requests so
+                * we need to check the mgmt queue for nops that need to
+                * be sent to aviod starvation
+                */
+               if (!list_empty(&conn->mgmtqueue))
+                       goto check_mgmt;
+       }
+
+       while (!list_empty(&conn->requeue)) {
+               /*
+                * we always do fastlogout - conn stop code will clean up.
+                */
+               if (conn->session->state == ISCSI_STATE_LOGGING_OUT)
+                       break;
+
+               task = list_entry(conn->requeue.next, struct iscsi_task,
+                                 running);
+               if (iscsi_check_tmf_restrictions(task, ISCSI_OP_SCSI_DATA_OUT))
+                       break;
+
+               conn->task = task;
+               list_del_init(&conn->task->running);
+               conn->task->state = ISCSI_TASK_RUNNING;
+               rc = iscsi_xmit_task(conn);
+               if (rc)
+                       goto done;
+               if (!list_empty(&conn->mgmtqueue))
+                       goto check_mgmt;
+       }
+       spin_unlock_bh(&conn->session->frwd_lock);
+       return -ENODATA;
+
+done:
+       spin_unlock_bh(&conn->session->frwd_lock);
+       return rc;
+}
+
+static void iscsi_xmitworker(struct work_struct *work)
+{
+       struct iscsi_conn *conn =
+               container_of(work, struct iscsi_conn, xmitwork);
+       int rc;
+       /*
+        * serialize Xmit worker on a per-connection basis.
+        */
+       do {
+               rc = iscsi_data_xmit(conn);
+       } while (rc >= 0 || rc == -EAGAIN);
+}
+
+static inline struct iscsi_task *iscsi_alloc_task(struct iscsi_conn *conn,
+                                                 struct scsi_cmnd *sc)
+{
+       struct iscsi_task *task;
+
+       if (!kfifo_out(&conn->session->cmdpool.queue,
+                        (void *) &task, sizeof(void *)))
+               return NULL;
+
+       sc->SCp.phase = conn->session->age;
+       sc->SCp.ptr = (char *) task;
+
+       atomic_set(&task->refcount, 1);
+       task->state = ISCSI_TASK_PENDING;
+       task->conn = conn;
+       task->sc = sc;
+       task->have_checked_conn = false;
+       task->last_timeout = jiffies;
+       task->last_xfer = jiffies;
+       task->protected = false;
+       INIT_LIST_HEAD(&task->running);
+       return task;
+}
+
+enum {
+       FAILURE_BAD_HOST = 1,
+       FAILURE_SESSION_FAILED,
+       FAILURE_SESSION_FREED,
+       FAILURE_WINDOW_CLOSED,
+       FAILURE_OOM,
+       FAILURE_SESSION_TERMINATE,
+       FAILURE_SESSION_IN_RECOVERY,
+       FAILURE_SESSION_RECOVERY_TIMEOUT,
+       FAILURE_SESSION_LOGGING_OUT,
+       FAILURE_SESSION_NOT_READY,
+};
+
+int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
+{
+       struct iscsi_cls_session *cls_session;
+       struct iscsi_host *ihost;
+       int reason = 0;
+       struct iscsi_session *session;
+       struct iscsi_conn *conn;
+       struct iscsi_task *task = NULL;
+
+       sc->result = 0;
+       sc->SCp.ptr = NULL;
+
+       ihost = shost_priv(host);
+
+       cls_session = starget_to_session(scsi_target(sc->device));
+       session = cls_session->dd_data;
+       spin_lock_bh(&session->frwd_lock);
+
+       reason = iscsi_session_chkready(cls_session);
+       if (reason) {
+               sc->result = reason;
+               goto fault;
+       }
+
+       if (session->state != ISCSI_STATE_LOGGED_IN) {
+               /*
+                * to handle the race between when we set the recovery state
+                * and block the session we requeue here (commands could
+                * be entering our queuecommand while a block is starting
+                * up because the block code is not locked)
+                */
+               switch (session->state) {
+               case ISCSI_STATE_FAILED:
+               case ISCSI_STATE_IN_RECOVERY:
+                       reason = FAILURE_SESSION_IN_RECOVERY;
+                       sc->result = DID_IMM_RETRY << 16;
+                       break;
+               case ISCSI_STATE_LOGGING_OUT:
+                       reason = FAILURE_SESSION_LOGGING_OUT;
+                       sc->result = DID_IMM_RETRY << 16;
+                       break;
+               case ISCSI_STATE_RECOVERY_FAILED:
+                       reason = FAILURE_SESSION_RECOVERY_TIMEOUT;
+                       sc->result = DID_TRANSPORT_FAILFAST << 16;
+                       break;
+               case ISCSI_STATE_TERMINATE:
+                       reason = FAILURE_SESSION_TERMINATE;
+                       sc->result = DID_NO_CONNECT << 16;
+                       break;
+               default:
+                       reason = FAILURE_SESSION_FREED;
+                       sc->result = DID_NO_CONNECT << 16;
+               }
+               goto fault;
+       }
+
+       conn = session->leadconn;
+       if (!conn) {
+               reason = FAILURE_SESSION_FREED;
+               sc->result = DID_NO_CONNECT << 16;
+               goto fault;
+       }
+
+       if (test_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx)) {
+               reason = FAILURE_SESSION_IN_RECOVERY;
+               sc->result = DID_REQUEUE;
+               goto fault;
+       }
+
+       if (iscsi_check_cmdsn_window_closed(conn)) {
+               reason = FAILURE_WINDOW_CLOSED;
+               goto reject;
+       }
+
+       task = iscsi_alloc_task(conn, sc);
+       if (!task) {
+               reason = FAILURE_OOM;
+               goto reject;
+       }
+
+       if (!ihost->workq) {
+               reason = iscsi_prep_scsi_cmd_pdu(task);
+               if (reason) {
+                       if (reason == -ENOMEM ||  reason == -EACCES) {
+                               reason = FAILURE_OOM;
+                               goto prepd_reject;
+                       } else {
+                               sc->result = DID_ABORT << 16;
+                               goto prepd_fault;
+                       }
+               }
+               if (session->tt->xmit_task(task)) {
+                       session->cmdsn--;
+                       reason = FAILURE_SESSION_NOT_READY;
+                       goto prepd_reject;
+               }
+       } else {
+               list_add_tail(&task->running, &conn->cmdqueue);
+               iscsi_conn_queue_work(conn);
+       }
+
+       session->queued_cmdsn++;
+       spin_unlock_bh(&session->frwd_lock);
+       return 0;
+
+prepd_reject:
+       iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
+reject:
+       spin_unlock_bh(&session->frwd_lock);
+       ISCSI_DBG_SESSION(session, "cmd 0x%x rejected (%d)\n",
+                         sc->cmnd[0], reason);
+       return SCSI_MLQUEUE_TARGET_BUSY;
+
+prepd_fault:
+       iscsi_complete_task(task, ISCSI_TASK_REQUEUE_SCSIQ);
+fault:
+       spin_unlock_bh(&session->frwd_lock);
+       ISCSI_DBG_SESSION(session, "iscsi: cmd 0x%x is not queued (%d)\n",
+                         sc->cmnd[0], reason);
+       if (!scsi_bidi_cmnd(sc))
+               scsi_set_resid(sc, scsi_bufflen(sc));
+       else {
+               scsi_out(sc)->resid = scsi_out(sc)->length;
+               scsi_in(sc)->resid = scsi_in(sc)->length;
+       }
+       sc->scsi_done(sc);
+       return 0;
+}
+EXPORT_SYMBOL_GPL(iscsi_queuecommand);
+
+int iscsi_target_alloc(struct scsi_target *starget)
+{
+       struct iscsi_cls_session *cls_session = starget_to_session(starget);
+       struct iscsi_session *session = cls_session->dd_data;
+
+       starget->can_queue = session->scsi_cmds_max;
+       return 0;
+}
+EXPORT_SYMBOL_GPL(iscsi_target_alloc);
+
+static void iscsi_tmf_timedout(unsigned long data)
+{
+       struct iscsi_conn *conn = (struct iscsi_conn *)data;
+       struct iscsi_session *session = conn->session;
+
+       spin_lock(&session->frwd_lock);
+       if (conn->tmf_state == TMF_QUEUED) {
+               conn->tmf_state = TMF_TIMEDOUT;
+               ISCSI_DBG_EH(session, "tmf timedout\n");
+               /* unblock eh_abort() */
+               wake_up(&conn->ehwait);
+       }
+       spin_unlock(&session->frwd_lock);
+}
+
+static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn,
+                                  struct iscsi_tm *hdr, int age,
+                                  int timeout)
+{
+       struct iscsi_session *session = conn->session;
+       struct iscsi_task *task;
+
+       task = __iscsi_conn_send_pdu(conn, (struct iscsi_hdr *)hdr,
+                                     NULL, 0);
+       if (!task) {
+               spin_unlock_bh(&session->frwd_lock);
+               iscsi_conn_printk(KERN_ERR, conn, "Could not send TMF.\n");
+               iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
+               spin_lock_bh(&session->frwd_lock);
+               return -EPERM;
+       }
+       conn->tmfcmd_pdus_cnt++;
+       conn->tmf_timer.expires = timeout * HZ + jiffies;
+       conn->tmf_timer.function = iscsi_tmf_timedout;
+       conn->tmf_timer.data = (unsigned long)conn;
+       add_timer(&conn->tmf_timer);
+       ISCSI_DBG_EH(session, "tmf set timeout\n");
+
+       spin_unlock_bh(&session->frwd_lock);
+       mutex_unlock(&session->eh_mutex);
+
+       /*
+        * block eh thread until:
+        *
+        * 1) tmf response
+        * 2) tmf timeout
+        * 3) session is terminated or restarted or userspace has
+        * given up on recovery
+        */
+       wait_event_interruptible(conn->ehwait, age != session->age ||
+                                session->state != ISCSI_STATE_LOGGED_IN ||
+                                conn->tmf_state != TMF_QUEUED);
+       if (signal_pending(current))
+               flush_signals(current);
+       del_timer_sync(&conn->tmf_timer);
+
+       mutex_lock(&session->eh_mutex);
+       spin_lock_bh(&session->frwd_lock);
+       /* if the session drops it will clean up the task */
+       if (age != session->age ||
+           session->state != ISCSI_STATE_LOGGED_IN)
+               return -ENOTCONN;
+       return 0;
+}
+
+/*
+ * Fail commands. session lock held and recv side suspended and xmit
+ * thread flushed
+ */
+static void fail_scsi_tasks(struct iscsi_conn *conn, u64 lun, int error)
+{
+       struct iscsi_task *task;
+       int i;
+
+       for (i = 0; i < conn->session->cmds_max; i++) {
+               task = conn->session->cmds[i];
+               if (!task->sc || task->state == ISCSI_TASK_FREE)
+                       continue;
+
+               if (lun != -1 && lun != task->sc->device->lun)
+                       continue;
+
+               ISCSI_DBG_SESSION(conn->session,
+                                 "failing sc %p itt 0x%x state %d\n",
+                                 task->sc, task->itt, task->state);
+               fail_scsi_task(task, error);
+       }
+}
+
+/**
+ * iscsi_suspend_queue - suspend iscsi_queuecommand
+ * @conn: iscsi conn to stop queueing IO on
+ *
+ * This grabs the session frwd_lock to make sure no one is in
+ * xmit_task/queuecommand, and then sets suspend to prevent
+ * new commands from being queued. This only needs to be called
+ * by offload drivers that need to sync a path like ep disconnect
+ * with the iscsi_queuecommand/xmit_task. To start IO again libiscsi
+ * will call iscsi_start_tx and iscsi_unblock_session when in FFP.
+ */
+void iscsi_suspend_queue(struct iscsi_conn *conn)
+{
+       spin_lock_bh(&conn->session->frwd_lock);
+       set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
+       spin_unlock_bh(&conn->session->frwd_lock);
+}
+EXPORT_SYMBOL_GPL(iscsi_suspend_queue);
+
+/**
+ * iscsi_suspend_tx - suspend iscsi_data_xmit
+ * @conn: iscsi conn tp stop processing IO on.
+ *
+ * This function sets the suspend bit to prevent iscsi_data_xmit
+ * from sending new IO, and if work is queued on the xmit thread
+ * it will wait for it to be completed.
+ */
+void iscsi_suspend_tx(struct iscsi_conn *conn)
+{
+       struct Scsi_Host *shost = conn->session->host;
+       struct iscsi_host *ihost = shost_priv(shost);
+
+       set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
+       if (ihost->workq)
+               flush_workqueue(ihost->workq);
+}
+EXPORT_SYMBOL_GPL(iscsi_suspend_tx);
+
+static void iscsi_start_tx(struct iscsi_conn *conn)
+{
+       clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
+       iscsi_conn_queue_work(conn);
+}
+
+/*
+ * We want to make sure a ping is in flight. It has timed out.
+ * And we are not busy processing a pdu that is making
+ * progress but got started before the ping and is taking a while
+ * to complete so the ping is just stuck behind it in a queue.
+ */
+static int iscsi_has_ping_timed_out(struct iscsi_conn *conn)
+{
+       if (conn->ping_task &&
+           time_before_eq(conn->last_recv + (conn->recv_timeout * HZ) +
+                          (conn->ping_timeout * HZ), jiffies))
+               return 1;
+       else
+               return 0;
+}
+
+static enum blk_eh_timer_return iscsi_eh_cmd_timed_out(struct scsi_cmnd *sc)
+{
+       enum blk_eh_timer_return rc = BLK_EH_NOT_HANDLED;
+       struct iscsi_task *task = NULL, *running_task;
+       struct iscsi_cls_session *cls_session;
+       struct iscsi_session *session;
+       struct iscsi_conn *conn;
+       int i;
+
+       cls_session = starget_to_session(scsi_target(sc->device));
+       session = cls_session->dd_data;
+
+       ISCSI_DBG_EH(session, "scsi cmd %p timedout\n", sc);
+
+       spin_lock(&session->frwd_lock);
+       task = (struct iscsi_task *)sc->SCp.ptr;
+       if (!task) {
+               /*
+                * Raced with completion. Blk layer has taken ownership
+                * so let timeout code complete it now.
+                */
+               rc = BLK_EH_HANDLED;
+               goto done;
+       }
+
+       if (session->state != ISCSI_STATE_LOGGED_IN) {
+               /*
+                * We are probably in the middle of iscsi recovery so let
+                * that complete and handle the error.
+                */
+               rc = BLK_EH_RESET_TIMER;
+               goto done;
+       }
+
+       conn = session->leadconn;
+       if (!conn) {
+               /* In the middle of shuting down */
+               rc = BLK_EH_RESET_TIMER;
+               goto done;
+       }
+
+       /*
+        * If we have sent (at least queued to the network layer) a pdu or
+        * recvd one for the task since the last timeout ask for
+        * more time. If on the next timeout we have not made progress
+        * we can check if it is the task or connection when we send the
+        * nop as a ping.
+        */
+       if (time_after(task->last_xfer, task->last_timeout)) {
+               ISCSI_DBG_EH(session, "Command making progress. Asking "
+                            "scsi-ml for more time to complete. "
+                            "Last data xfer at %lu. Last timeout was at "
+                            "%lu\n.", task->last_xfer, task->last_timeout);
+               task->have_checked_conn = false;
+               rc = BLK_EH_RESET_TIMER;
+               goto done;
+       }
+
+       if (!conn->recv_timeout && !conn->ping_timeout)
+               goto done;
+       /*
+        * if the ping timedout then we are in the middle of cleaning up
+        * and can let the iscsi eh handle it
+        */
+       if (iscsi_has_ping_timed_out(conn)) {
+               rc = BLK_EH_RESET_TIMER;
+               goto done;
+       }
+
+       for (i = 0; i < conn->session->cmds_max; i++) {
+               running_task = conn->session->cmds[i];
+               if (!running_task->sc || running_task == task ||
+                    running_task->state != ISCSI_TASK_RUNNING)
+                       continue;
+
+               /*
+                * Only check if cmds started before this one have made
+                * progress, or this could never fail
+                */
+               if (time_after(running_task->sc->jiffies_at_alloc,
+                              task->sc->jiffies_at_alloc))
+                       continue;
+
+               if (time_after(running_task->last_xfer, task->last_timeout)) {
+                       /*
+                        * This task has not made progress, but a task
+                        * started before us has transferred data since
+                        * we started/last-checked. We could be queueing
+                        * too many tasks or the LU is bad.
+                        *
+                        * If the device is bad the cmds ahead of us on
+                        * other devs will complete, and this loop will
+                        * eventually fail starting the scsi eh.
+                        */
+                       ISCSI_DBG_EH(session, "Command has not made progress "
+                                    "but commands ahead of it have. "
+                                    "Asking scsi-ml for more time to "
+                                    "complete. Our last xfer vs running task "
+                                    "last xfer %lu/%lu. Last check %lu.\n",
+                                    task->last_xfer, running_task->last_xfer,
+                                    task->last_timeout);
+                       rc = BLK_EH_RESET_TIMER;
+                       goto done;
+               }
+       }
+
+       /* Assumes nop timeout is shorter than scsi cmd timeout */
+       if (task->have_checked_conn)
+               goto done;
+
+       /*
+        * Checking the transport already or nop from a cmd timeout still
+        * running
+        */
+       if (conn->ping_task) {
+               task->have_checked_conn = true;
+               rc = BLK_EH_RESET_TIMER;
+               goto done;
+       }
+
+       /* Make sure there is a transport check done */
+       iscsi_send_nopout(conn, NULL);
+       task->have_checked_conn = true;
+       rc = BLK_EH_RESET_TIMER;
+
+done:
+       if (task)
+               task->last_timeout = jiffies;
+       spin_unlock(&session->frwd_lock);
+       ISCSI_DBG_EH(session, "return %s\n", rc == BLK_EH_RESET_TIMER ?
+                    "timer reset" : "nh");
+       return rc;
+}
+
+static void iscsi_check_transport_timeouts(unsigned long data)
+{
+       struct iscsi_conn *conn = (struct iscsi_conn *)data;
+       struct iscsi_session *session = conn->session;
+       unsigned long recv_timeout, next_timeout = 0, last_recv;
+
+       spin_lock(&session->frwd_lock);
+       if (session->state != ISCSI_STATE_LOGGED_IN)
+               goto done;
+
+       recv_timeout = conn->recv_timeout;
+       if (!recv_timeout)
+               goto done;
+
+       recv_timeout *= HZ;
+       last_recv = conn->last_recv;
+
+       if (iscsi_has_ping_timed_out(conn)) {
+               iscsi_conn_printk(KERN_ERR, conn, "ping timeout of %d secs "
+                                 "expired, recv timeout %d, last rx %lu, "
+                                 "last ping %lu, now %lu\n",
+                                 conn->ping_timeout, conn->recv_timeout,
+                                 last_recv, conn->last_ping, jiffies);
+               spin_unlock(&session->frwd_lock);
+               iscsi_conn_failure(conn, ISCSI_ERR_NOP_TIMEDOUT);
+               return;
+       }
+
+       if (time_before_eq(last_recv + recv_timeout, jiffies)) {
+               /* send a ping to try to provoke some traffic */
+               ISCSI_DBG_CONN(conn, "Sending nopout as ping\n");
+               iscsi_send_nopout(conn, NULL);
+               next_timeout = conn->last_ping + (conn->ping_timeout * HZ);
+       } else
+               next_timeout = last_recv + recv_timeout;
+
+       ISCSI_DBG_CONN(conn, "Setting next tmo %lu\n", next_timeout);
+       mod_timer(&conn->transport_timer, next_timeout);
+done:
+       spin_unlock(&session->frwd_lock);
+}
+
+static void iscsi_prep_abort_task_pdu(struct iscsi_task *task,
+                                     struct iscsi_tm *hdr)
+{
+       memset(hdr, 0, sizeof(*hdr));
+       hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
+       hdr->flags = ISCSI_TM_FUNC_ABORT_TASK & ISCSI_FLAG_TM_FUNC_MASK;
+       hdr->flags |= ISCSI_FLAG_CMD_FINAL;
+       hdr->lun = task->lun;
+       hdr->rtt = task->hdr_itt;
+       hdr->refcmdsn = task->cmdsn;
+}
+
+int iscsi_eh_abort(struct scsi_cmnd *sc)
+{
+       struct iscsi_cls_session *cls_session;
+       struct iscsi_session *session;
+       struct iscsi_conn *conn;
+       struct iscsi_task *task;
+       struct iscsi_tm *hdr;
+       int rc, age;
+
+       cls_session = starget_to_session(scsi_target(sc->device));
+       session = cls_session->dd_data;
+
+       ISCSI_DBG_EH(session, "aborting sc %p\n", sc);
+
+       mutex_lock(&session->eh_mutex);
+       spin_lock_bh(&session->frwd_lock);
+       /*
+        * if session was ISCSI_STATE_IN_RECOVERY then we may not have
+        * got the command.
+        */
+       if (!sc->SCp.ptr) {
+               ISCSI_DBG_EH(session, "sc never reached iscsi layer or "
+                                     "it completed.\n");
+               spin_unlock_bh(&session->frwd_lock);
+               mutex_unlock(&session->eh_mutex);
+               return SUCCESS;
+       }
+
+       /*
+        * If we are not logged in or we have started a new session
+        * then let the host reset code handle this
+        */
+       if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN ||
+           sc->SCp.phase != session->age) {
+               spin_unlock_bh(&session->frwd_lock);
+               mutex_unlock(&session->eh_mutex);
+               ISCSI_DBG_EH(session, "failing abort due to dropped "
+                                 "session.\n");
+               return FAILED;
+       }
+
+       conn = session->leadconn;
+       conn->eh_abort_cnt++;
+       age = session->age;
+
+       task = (struct iscsi_task *)sc->SCp.ptr;
+       ISCSI_DBG_EH(session, "aborting [sc %p itt 0x%x]\n",
+                    sc, task->itt);
+
+       /* task completed before time out */
+       if (!task->sc) {
+               ISCSI_DBG_EH(session, "sc completed while abort in progress\n");
+               goto success;
+       }
+
+       if (task->state == ISCSI_TASK_PENDING) {
+               fail_scsi_task(task, DID_ABORT);
+               goto success;
+       }
+
+       /* only have one tmf outstanding at a time */
+       if (conn->tmf_state != TMF_INITIAL)
+               goto failed;
+       conn->tmf_state = TMF_QUEUED;
+
+       hdr = &conn->tmhdr;
+       iscsi_prep_abort_task_pdu(task, hdr);
+
+       if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) {
+               rc = FAILED;
+               goto failed;
+       }
+
+       switch (conn->tmf_state) {
+       case TMF_SUCCESS:
+               spin_unlock_bh(&session->frwd_lock);
+               /*
+                * stop tx side incase the target had sent a abort rsp but
+                * the initiator was still writing out data.
+                */
+               iscsi_suspend_tx(conn);
+               /*
+                * we do not stop the recv side because targets have been
+                * good and have never sent us a successful tmf response
+                * then sent more data for the cmd.
+                */
+               spin_lock_bh(&session->frwd_lock);
+               fail_scsi_task(task, DID_ABORT);
+               conn->tmf_state = TMF_INITIAL;
+               memset(hdr, 0, sizeof(*hdr));
+               spin_unlock_bh(&session->frwd_lock);
+               iscsi_start_tx(conn);
+               goto success_unlocked;
+       case TMF_TIMEDOUT:
+               spin_unlock_bh(&session->frwd_lock);
+               iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
+               goto failed_unlocked;
+       case TMF_NOT_FOUND:
+               if (!sc->SCp.ptr) {
+                       conn->tmf_state = TMF_INITIAL;
+                       memset(hdr, 0, sizeof(*hdr));
+                       /* task completed before tmf abort response */
+                       ISCSI_DBG_EH(session, "sc completed while abort in "
+                                             "progress\n");
+                       goto success;
+               }
+               /* fall through */
+       default:
+               conn->tmf_state = TMF_INITIAL;
+               goto failed;
+       }
+
+success:
+       spin_unlock_bh(&session->frwd_lock);
+success_unlocked:
+       ISCSI_DBG_EH(session, "abort success [sc %p itt 0x%x]\n",
+                    sc, task->itt);
+       mutex_unlock(&session->eh_mutex);
+       return SUCCESS;
+
+failed:
+       spin_unlock_bh(&session->frwd_lock);
+failed_unlocked:
+       ISCSI_DBG_EH(session, "abort failed [sc %p itt 0x%x]\n", sc,
+                    task ? task->itt : 0);
+       mutex_unlock(&session->eh_mutex);
+       return FAILED;
+}
+EXPORT_SYMBOL_GPL(iscsi_eh_abort);
+
+static void iscsi_prep_lun_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
+{
+       memset(hdr, 0, sizeof(*hdr));
+       hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
+       hdr->flags = ISCSI_TM_FUNC_LOGICAL_UNIT_RESET & ISCSI_FLAG_TM_FUNC_MASK;
+       hdr->flags |= ISCSI_FLAG_CMD_FINAL;
+       int_to_scsilun(sc->device->lun, &hdr->lun);
+       hdr->rtt = RESERVED_ITT;
+}
+
+int iscsi_eh_device_reset(struct scsi_cmnd *sc)
+{
+       struct iscsi_cls_session *cls_session;
+       struct iscsi_session *session;
+       struct iscsi_conn *conn;
+       struct iscsi_tm *hdr;
+       int rc = FAILED;
+
+       cls_session = starget_to_session(scsi_target(sc->device));
+       session = cls_session->dd_data;
+
+       ISCSI_DBG_EH(session, "LU Reset [sc %p lun %llu]\n", sc,
+                    sc->device->lun);
+
+       mutex_lock(&session->eh_mutex);
+       spin_lock_bh(&session->frwd_lock);
+       /*
+        * Just check if we are not logged in. We cannot check for
+        * the phase because the reset could come from a ioctl.
+        */
+       if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
+               goto unlock;
+       conn = session->leadconn;
+
+       /* only have one tmf outstanding at a time */
+       if (conn->tmf_state != TMF_INITIAL)
+               goto unlock;
+       conn->tmf_state = TMF_QUEUED;
+
+       hdr = &conn->tmhdr;
+       iscsi_prep_lun_reset_pdu(sc, hdr);
+
+       if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
+                                   session->lu_reset_timeout)) {
+               rc = FAILED;
+               goto unlock;
+       }
+
+       switch (conn->tmf_state) {
+       case TMF_SUCCESS:
+               break;
+       case TMF_TIMEDOUT:
+               spin_unlock_bh(&session->frwd_lock);
+               iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
+               goto done;
+       default:
+               conn->tmf_state = TMF_INITIAL;
+               goto unlock;
+       }
+
+       rc = SUCCESS;
+       spin_unlock_bh(&session->frwd_lock);
+
+       iscsi_suspend_tx(conn);
+
+       spin_lock_bh(&session->frwd_lock);
+       memset(hdr, 0, sizeof(*hdr));
+       fail_scsi_tasks(conn, sc->device->lun, DID_ERROR);
+       conn->tmf_state = TMF_INITIAL;
+       spin_unlock_bh(&session->frwd_lock);
+
+       iscsi_start_tx(conn);
+       goto done;
+
+unlock:
+       spin_unlock_bh(&session->frwd_lock);
+done:
+       ISCSI_DBG_EH(session, "dev reset result = %s\n",
+                    rc == SUCCESS ? "SUCCESS" : "FAILED");
+       mutex_unlock(&session->eh_mutex);
+       return rc;
+}
+EXPORT_SYMBOL_GPL(iscsi_eh_device_reset);
+
+void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session)
+{
+       struct iscsi_session *session = cls_session->dd_data;
+
+       spin_lock_bh(&session->frwd_lock);
+       if (session->state != ISCSI_STATE_LOGGED_IN) {
+               session->state = ISCSI_STATE_RECOVERY_FAILED;
+               if (session->leadconn)
+                       wake_up(&session->leadconn->ehwait);
+       }
+       spin_unlock_bh(&session->frwd_lock);
+}
+EXPORT_SYMBOL_GPL(iscsi_session_recovery_timedout);
+
+/**
+ * iscsi_eh_session_reset - drop session and attempt relogin
+ * @sc: scsi command
+ *
+ * This function will wait for a relogin, session termination from
+ * userspace, or a recovery/replacement timeout.
+ */
+int iscsi_eh_session_reset(struct scsi_cmnd *sc)
+{
+       struct iscsi_cls_session *cls_session;
+       struct iscsi_session *session;
+       struct iscsi_conn *conn;
+
+       cls_session = starget_to_session(scsi_target(sc->device));
+       session = cls_session->dd_data;
+       conn = session->leadconn;
+
+       mutex_lock(&session->eh_mutex);
+       spin_lock_bh(&session->frwd_lock);
+       if (session->state == ISCSI_STATE_TERMINATE) {
+failed:
+               ISCSI_DBG_EH(session,
+                            "failing session reset: Could not log back into "
+                            "%s, %s [age %d]\n", session->targetname,
+                            conn->persistent_address, session->age);
+               spin_unlock_bh(&session->frwd_lock);
+               mutex_unlock(&session->eh_mutex);
+               return FAILED;
+       }
+
+       spin_unlock_bh(&session->frwd_lock);
+       mutex_unlock(&session->eh_mutex);
+       /*
+        * we drop the lock here but the leadconn cannot be destoyed while
+        * we are in the scsi eh
+        */
+       iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
+
+       ISCSI_DBG_EH(session, "wait for relogin\n");
+       wait_event_interruptible(conn->ehwait,
+                                session->state == ISCSI_STATE_TERMINATE ||
+                                session->state == ISCSI_STATE_LOGGED_IN ||
+                                session->state == ISCSI_STATE_RECOVERY_FAILED);
+       if (signal_pending(current))
+               flush_signals(current);
+
+       mutex_lock(&session->eh_mutex);
+       spin_lock_bh(&session->frwd_lock);
+       if (session->state == ISCSI_STATE_LOGGED_IN) {
+               ISCSI_DBG_EH(session,
+                            "session reset succeeded for %s,%s\n",
+                            session->targetname, conn->persistent_address);
+       } else
+               goto failed;
+       spin_unlock_bh(&session->frwd_lock);
+       mutex_unlock(&session->eh_mutex);
+       return SUCCESS;
+}
+EXPORT_SYMBOL_GPL(iscsi_eh_session_reset);
+
+static void iscsi_prep_tgt_reset_pdu(struct scsi_cmnd *sc, struct iscsi_tm *hdr)
+{
+       memset(hdr, 0, sizeof(*hdr));
+       hdr->opcode = ISCSI_OP_SCSI_TMFUNC | ISCSI_OP_IMMEDIATE;
+       hdr->flags = ISCSI_TM_FUNC_TARGET_WARM_RESET & ISCSI_FLAG_TM_FUNC_MASK;
+       hdr->flags |= ISCSI_FLAG_CMD_FINAL;
+       hdr->rtt = RESERVED_ITT;
+}
+
+/**
+ * iscsi_eh_target_reset - reset target
+ * @sc: scsi command
+ *
+ * This will attempt to send a warm target reset.
+ */
+int iscsi_eh_target_reset(struct scsi_cmnd *sc)
+{
+       struct iscsi_cls_session *cls_session;
+       struct iscsi_session *session;
+       struct iscsi_conn *conn;
+       struct iscsi_tm *hdr;
+       int rc = FAILED;
+
+       cls_session = starget_to_session(scsi_target(sc->device));
+       session = cls_session->dd_data;
+
+       ISCSI_DBG_EH(session, "tgt Reset [sc %p tgt %s]\n", sc,
+                    session->targetname);
+
+       mutex_lock(&session->eh_mutex);
+       spin_lock_bh(&session->frwd_lock);
+       /*
+        * Just check if we are not logged in. We cannot check for
+        * the phase because the reset could come from a ioctl.
+        */
+       if (!session->leadconn || session->state != ISCSI_STATE_LOGGED_IN)
+               goto unlock;
+       conn = session->leadconn;
+
+       /* only have one tmf outstanding at a time */
+       if (conn->tmf_state != TMF_INITIAL)
+               goto unlock;
+       conn->tmf_state = TMF_QUEUED;
+
+       hdr = &conn->tmhdr;
+       iscsi_prep_tgt_reset_pdu(sc, hdr);
+
+       if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age,
+                                   session->tgt_reset_timeout)) {
+               rc = FAILED;
+               goto unlock;
+       }
+
+       switch (conn->tmf_state) {
+       case TMF_SUCCESS:
+               break;
+       case TMF_TIMEDOUT:
+               spin_unlock_bh(&session->frwd_lock);
+               iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST);
+               goto done;
+       default:
+               conn->tmf_state = TMF_INITIAL;
+               goto unlock;
+       }
+
+       rc = SUCCESS;
+       spin_unlock_bh(&session->frwd_lock);
+
+       iscsi_suspend_tx(conn);
+
+       spin_lock_bh(&session->frwd_lock);
+       memset(hdr, 0, sizeof(*hdr));
+       fail_scsi_tasks(conn, -1, DID_ERROR);
+       conn->tmf_state = TMF_INITIAL;
+       spin_unlock_bh(&session->frwd_lock);
+
+       iscsi_start_tx(conn);
+       goto done;
+
+unlock:
+       spin_unlock_bh(&session->frwd_lock);
+done:
+       ISCSI_DBG_EH(session, "tgt %s reset result = %s\n", session->targetname,
+                    rc == SUCCESS ? "SUCCESS" : "FAILED");
+       mutex_unlock(&session->eh_mutex);
+       return rc;
+}
+EXPORT_SYMBOL_GPL(iscsi_eh_target_reset);
+
+/**
+ * iscsi_eh_recover_target - reset target and possibly the session
+ * @sc: scsi command
+ *
+ * This will attempt to send a warm target reset. If that fails,
+ * we will escalate to ERL0 session recovery.
+ */
+int iscsi_eh_recover_target(struct scsi_cmnd *sc)
+{
+       int rc;
+
+       rc = iscsi_eh_target_reset(sc);
+       if (rc == FAILED)
+               rc = iscsi_eh_session_reset(sc);
+       return rc;
+}
+EXPORT_SYMBOL_GPL(iscsi_eh_recover_target);
+
+/*
+ * Pre-allocate a pool of @max items of @item_size. By default, the pool
+ * should be accessed via kfifo_{get,put} on q->queue.
+ * Optionally, the caller can obtain the array of object pointers
+ * by passing in a non-NULL @items pointer
+ */
+int
+iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
+{
+       int i, num_arrays = 1;
+
+       memset(q, 0, sizeof(*q));
+
+       q->max = max;
+
+       /* If the user passed an items pointer, he wants a copy of
+        * the array. */
+       if (items)
+               num_arrays++;
+       q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
+       if (q->pool == NULL)
+               return -ENOMEM;
+
+       kfifo_init(&q->queue, (void*)q->pool, max * sizeof(void*));
+
+       for (i = 0; i < max; i++) {
+               q->pool[i] = kzalloc(item_size, GFP_KERNEL);
+               if (q->pool[i] == NULL) {
+                       q->max = i;
+                       goto enomem;
+               }
+               kfifo_in(&q->queue, (void*)&q->pool[i], sizeof(void*));
+       }
+
+       if (items) {
+               *items = q->pool + max;
+               memcpy(*items, q->pool, max * sizeof(void *));
+       }
+
+       return 0;
+
+enomem:
+       iscsi_pool_free(q);
+       return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(iscsi_pool_init);
+
+void iscsi_pool_free(struct iscsi_pool *q)
+{
+       int i;
+
+       for (i = 0; i < q->max; i++)
+               kfree(q->pool[i]);
+       kfree(q->pool);
+}
+EXPORT_SYMBOL_GPL(iscsi_pool_free);
+
+/**
+ * iscsi_host_add - add host to system
+ * @shost: scsi host
+ * @pdev: parent device
+ *
+ * This should be called by partial offload and software iscsi drivers
+ * to add a host to the system.
+ */
+int iscsi_host_add(struct Scsi_Host *shost, struct device *pdev)
+{
+       if (!shost->can_queue)
+               shost->can_queue = ISCSI_DEF_XMIT_CMDS_MAX;
+
+       if (!shost->cmd_per_lun)
+               shost->cmd_per_lun = ISCSI_DEF_CMD_PER_LUN;
+
+       if (!shost->transportt->eh_timed_out)
+               shost->transportt->eh_timed_out = iscsi_eh_cmd_timed_out;
+       return scsi_add_host(shost, pdev);
+}
+EXPORT_SYMBOL_GPL(iscsi_host_add);
+
+/**
+ * iscsi_host_alloc - allocate a host and driver data
+ * @sht: scsi host template
+ * @dd_data_size: driver host data size
+ * @xmit_can_sleep: bool indicating if LLD will queue IO from a work queue
+ *
+ * This should be called by partial offload and software iscsi drivers.
+ * To access the driver specific memory use the iscsi_host_priv() macro.
+ */
+struct Scsi_Host *iscsi_host_alloc(struct scsi_host_template *sht,
+                                  int dd_data_size, bool xmit_can_sleep)
+{
+       struct Scsi_Host *shost;
+       struct iscsi_host *ihost;
+
+       shost = scsi_host_alloc(sht, sizeof(struct iscsi_host) + dd_data_size);
+       if (!shost)
+               return NULL;
+       ihost = shost_priv(shost);
+
+       if (xmit_can_sleep) {
+               snprintf(ihost->workq_name, sizeof(ihost->workq_name),
+                       "iscsi_q_%d", shost->host_no);
+               ihost->workq = create_singlethread_workqueue(ihost->workq_name);
+               if (!ihost->workq)
+                       goto free_host;
+       }
+
+       spin_lock_init(&ihost->lock);
+       ihost->state = ISCSI_HOST_SETUP;
+       ihost->num_sessions = 0;
+       init_waitqueue_head(&ihost->session_removal_wq);
+       return shost;
+
+free_host:
+       scsi_host_put(shost);
+       return NULL;
+}
+EXPORT_SYMBOL_GPL(iscsi_host_alloc);
+
+static void iscsi_notify_host_removed(struct iscsi_cls_session *cls_session)
+{
+       iscsi_session_failure(cls_session->dd_data, ISCSI_ERR_INVALID_HOST);
+}
+
+/**
+ * iscsi_host_remove - remove host and sessions
+ * @shost: scsi host
+ *
+ * If there are any sessions left, this will initiate the removal and wait
+ * for the completion.
+ */
+void iscsi_host_remove(struct Scsi_Host *shost)
+{
+       struct iscsi_host *ihost = shost_priv(shost);
+       unsigned long flags;
+
+       spin_lock_irqsave(&ihost->lock, flags);
+       ihost->state = ISCSI_HOST_REMOVED;
+       spin_unlock_irqrestore(&ihost->lock, flags);
+
+       iscsi_host_for_each_session(shost, iscsi_notify_host_removed);
+       wait_event_interruptible(ihost->session_removal_wq,
+                                ihost->num_sessions == 0);
+       if (signal_pending(current))
+               flush_signals(current);
+
+       scsi_remove_host(shost);
+       if (ihost->workq)
+               destroy_workqueue(ihost->workq);
+}
+EXPORT_SYMBOL_GPL(iscsi_host_remove);
+
+void iscsi_host_free(struct Scsi_Host *shost)
+{
+       struct iscsi_host *ihost = shost_priv(shost);
+
+       kfree(ihost->netdev);
+       kfree(ihost->hwaddress);
+       kfree(ihost->initiatorname);
+       scsi_host_put(shost);
+}
+EXPORT_SYMBOL_GPL(iscsi_host_free);
+
+static void iscsi_host_dec_session_cnt(struct Scsi_Host *shost)
+{
+       struct iscsi_host *ihost = shost_priv(shost);
+       unsigned long flags;
+
+       shost = scsi_host_get(shost);
+       if (!shost) {
+               printk(KERN_ERR "Invalid state. Cannot notify host removal "
+                     "of session teardown event because host already "
+                     "removed.\n");
+               return;
+       }
+
+       spin_lock_irqsave(&ihost->lock, flags);
+       ihost->num_sessions--;
+       if (ihost->num_sessions == 0)
+               wake_up(&ihost->session_removal_wq);
+       spin_unlock_irqrestore(&ihost->lock, flags);
+       scsi_host_put(shost);
+}
+
+/**
+ * iscsi_session_setup - create iscsi cls session and host and session
+ * @iscsit: iscsi transport template
+ * @shost: scsi host
+ * @cmds_max: session can queue
+ * @cmd_task_size: LLD task private data size
+ * @initial_cmdsn: initial CmdSN
+ *
+ * This can be used by software iscsi_transports that allocate
+ * a session per scsi host.
+ *
+ * Callers should set cmds_max to the largest total numer (mgmt + scsi) of
+ * tasks they support. The iscsi layer reserves ISCSI_MGMT_CMDS_MAX tasks
+ * for nop handling and login/logout requests.
+ */
+struct iscsi_cls_session *
+iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
+                   uint16_t cmds_max, int dd_size, int cmd_task_size,
+                   uint32_t initial_cmdsn, unsigned int id)
+{
+       struct iscsi_host *ihost = shost_priv(shost);
+       struct iscsi_session *session;
+       struct iscsi_cls_session *cls_session;
+       int cmd_i, scsi_cmds, total_cmds = cmds_max;
+       unsigned long flags;
+
+       spin_lock_irqsave(&ihost->lock, flags);
+       if (ihost->state == ISCSI_HOST_REMOVED) {
+               spin_unlock_irqrestore(&ihost->lock, flags);
+               return NULL;
+       }
+       ihost->num_sessions++;
+       spin_unlock_irqrestore(&ihost->lock, flags);
+
+       if (!total_cmds)
+               total_cmds = ISCSI_DEF_XMIT_CMDS_MAX;
+       /*
+        * The iscsi layer needs some tasks for nop handling and tmfs,
+        * so the cmds_max must at least be greater than ISCSI_MGMT_CMDS_MAX
+        * + 1 command for scsi IO.
+        */
+       if (total_cmds < ISCSI_TOTAL_CMDS_MIN) {
+               printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
+                      "must be a power of two that is at least %d.\n",
+                      total_cmds, ISCSI_TOTAL_CMDS_MIN);
+               goto dec_session_count;
+       }
+
+       if (total_cmds > ISCSI_TOTAL_CMDS_MAX) {
+               printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
+                      "must be a power of 2 less than or equal to %d.\n",
+                      cmds_max, ISCSI_TOTAL_CMDS_MAX);
+               total_cmds = ISCSI_TOTAL_CMDS_MAX;
+       }
+
+       if (!is_power_of_2(total_cmds)) {
+               printk(KERN_ERR "iscsi: invalid can_queue of %d. can_queue "
+                      "must be a power of 2.\n", total_cmds);
+               total_cmds = rounddown_pow_of_two(total_cmds);
+               if (total_cmds < ISCSI_TOTAL_CMDS_MIN)
+                       return NULL;
+               printk(KERN_INFO "iscsi: Rounding can_queue to %d.\n",
+                      total_cmds);
+       }
+       scsi_cmds = total_cmds - ISCSI_MGMT_CMDS_MAX;
+
+       cls_session = iscsi_alloc_session(shost, iscsit,
+                                         sizeof(struct iscsi_session) +
+                                         dd_size);
+       if (!cls_session)
+               goto dec_session_count;
+       session = cls_session->dd_data;
+       session->cls_session = cls_session;
+       session->host = shost;
+       session->state = ISCSI_STATE_FREE;
+       session->fast_abort = 1;
+       session->tgt_reset_timeout = 30;
+       session->lu_reset_timeout = 15;
+       session->abort_timeout = 10;
+       session->scsi_cmds_max = scsi_cmds;
+       session->cmds_max = total_cmds;
+       session->queued_cmdsn = session->cmdsn = initial_cmdsn;
+       session->exp_cmdsn = initial_cmdsn + 1;
+       session->max_cmdsn = initial_cmdsn + 1;
+       session->max_r2t = 1;
+       session->tt = iscsit;
+       session->dd_data = cls_session->dd_data + sizeof(*session);
+
+       mutex_init(&session->eh_mutex);
+       spin_lock_init(&session->frwd_lock);
+       spin_lock_init(&session->back_lock);
+
+       /* initialize SCSI PDU commands pool */
+       if (iscsi_pool_init(&session->cmdpool, session->cmds_max,
+                           (void***)&session->cmds,
+                           cmd_task_size + sizeof(struct iscsi_task)))
+               goto cmdpool_alloc_fail;
+
+       /* pre-format cmds pool with ITT */
+       for (cmd_i = 0; cmd_i < session->cmds_max; cmd_i++) {
+               struct iscsi_task *task = session->cmds[cmd_i];
+
+               if (cmd_task_size)
+                       task->dd_data = &task[1];
+               task->itt = cmd_i;
+               task->state = ISCSI_TASK_FREE;
+               INIT_LIST_HEAD(&task->running);
+       }
+
+       if (!try_module_get(iscsit->owner))
+               goto module_get_fail;
+
+       if (iscsi_add_session(cls_session, id))
+               goto cls_session_fail;
+
+       return cls_session;
+
+cls_session_fail:
+       module_put(iscsit->owner);
+module_get_fail:
+       iscsi_pool_free(&session->cmdpool);
+cmdpool_alloc_fail:
+       iscsi_free_session(cls_session);
+dec_session_count:
+       iscsi_host_dec_session_cnt(shost);
+       return NULL;
+}
+EXPORT_SYMBOL_GPL(iscsi_session_setup);
+
+/**
+ * iscsi_session_teardown - destroy session, host, and cls_session
+ * @cls_session: iscsi session
+ *
+ * The driver must have called iscsi_remove_session before
+ * calling this.
+ */
+void iscsi_session_teardown(struct iscsi_cls_session *cls_session)
+{
+       struct iscsi_session *session = cls_session->dd_data;
+       struct module *owner = cls_session->transport->owner;
+       struct Scsi_Host *shost = session->host;
+
+       iscsi_pool_free(&session->cmdpool);
+
+       kfree(session->password);
+       kfree(session->password_in);
+       kfree(session->username);
+       kfree(session->username_in);
+       kfree(session->targetname);
+       kfree(session->targetalias);
+       kfree(session->initiatorname);
+       kfree(session->boot_root);
+       kfree(session->boot_nic);
+       kfree(session->boot_target);
+       kfree(session->ifacename);
+       kfree(session->portal_type);
+       kfree(session->discovery_parent_type);
+
+       iscsi_destroy_session(cls_session);
+       iscsi_host_dec_session_cnt(shost);
+       module_put(owner);
+}
+EXPORT_SYMBOL_GPL(iscsi_session_teardown);
+
+/**
+ * iscsi_conn_setup - create iscsi_cls_conn and iscsi_conn
+ * @cls_session: iscsi_cls_session
+ * @dd_size: private driver data size
+ * @conn_idx: cid
+ */
+struct iscsi_cls_conn *
+iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
+                uint32_t conn_idx)
+{
+       struct iscsi_session *session = cls_session->dd_data;
+       struct iscsi_conn *conn;
+       struct iscsi_cls_conn *cls_conn;
+       char *data;
+
+       cls_conn = iscsi_create_conn(cls_session, sizeof(*conn) + dd_size,
+                                    conn_idx);
+       if (!cls_conn)
+               return NULL;
+       conn = cls_conn->dd_data;
+       memset(conn, 0, sizeof(*conn) + dd_size);
+
+       conn->dd_data = cls_conn->dd_data + sizeof(*conn);
+       conn->session = session;
+       conn->cls_conn = cls_conn;
+       conn->c_stage = ISCSI_CONN_INITIAL_STAGE;
+       conn->id = conn_idx;
+       conn->exp_statsn = 0;
+       conn->tmf_state = TMF_INITIAL;
+
+       init_timer(&conn->transport_timer);
+       conn->transport_timer.data = (unsigned long)conn;
+       conn->transport_timer.function = iscsi_check_transport_timeouts;
+
+       INIT_LIST_HEAD(&conn->mgmtqueue);
+       INIT_LIST_HEAD(&conn->cmdqueue);
+       INIT_LIST_HEAD(&conn->requeue);
+       INIT_WORK(&conn->xmitwork, iscsi_xmitworker);
+
+       /* allocate login_task used for the login/text sequences */
+       spin_lock_bh(&session->frwd_lock);
+       if (!kfifo_out(&session->cmdpool.queue,
+                         (void*)&conn->login_task,
+                        sizeof(void*))) {
+               spin_unlock_bh(&session->frwd_lock);
+               goto login_task_alloc_fail;
+       }
+       spin_unlock_bh(&session->frwd_lock);
+
+       data = (char *) __get_free_pages(GFP_KERNEL,
+                                        get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
+       if (!data)
+               goto login_task_data_alloc_fail;
+       conn->login_task->data = conn->data = data;
+
+       init_timer(&conn->tmf_timer);
+       init_waitqueue_head(&conn->ehwait);
+
+       return cls_conn;
+
+login_task_data_alloc_fail:
+       kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
+                   sizeof(void*));
+login_task_alloc_fail:
+       iscsi_destroy_conn(cls_conn);
+       return NULL;
+}
+EXPORT_SYMBOL_GPL(iscsi_conn_setup);
+
+/**
+ * iscsi_conn_teardown - teardown iscsi connection
+ * cls_conn: iscsi class connection
+ *
+ * TODO: we may need to make this into a two step process
+ * like scsi-mls remove + put host
+ */
+void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn)
+{
+       struct iscsi_conn *conn = cls_conn->dd_data;
+       struct iscsi_session *session = conn->session;
+       unsigned long flags;
+
+       del_timer_sync(&conn->transport_timer);
+
+       spin_lock_bh(&session->frwd_lock);
+       conn->c_stage = ISCSI_CONN_CLEANUP_WAIT;
+       if (session->leadconn == conn) {
+               /*
+                * leading connection? then give up on recovery.
+                */
+               session->state = ISCSI_STATE_TERMINATE;
+               wake_up(&conn->ehwait);
+       }
+       spin_unlock_bh(&session->frwd_lock);
+
+       /*
+        * Block until all in-progress commands for this connection
+        * time out or fail.
+        */
+       for (;;) {
+               spin_lock_irqsave(session->host->host_lock, flags);
+               if (!atomic_read(&session->host->host_busy)) { /* OK for ERL == 0 */
+                       spin_unlock_irqrestore(session->host->host_lock, flags);
+                       break;
+               }
+               spin_unlock_irqrestore(session->host->host_lock, flags);
+               msleep_interruptible(500);
+               iscsi_conn_printk(KERN_INFO, conn, "iscsi conn_destroy(): "
+                                 "host_busy %d host_failed %d\n",
+                                 atomic_read(&session->host->host_busy),
+                                 session->host->host_failed);
+               /*
+                * force eh_abort() to unblock
+                */
+               wake_up(&conn->ehwait);
+       }
+
+       /* flush queued up work because we free the connection below */
+       iscsi_suspend_tx(conn);
+
+       spin_lock_bh(&session->frwd_lock);
+       free_pages((unsigned long) conn->data,
+                  get_order(ISCSI_DEF_MAX_RECV_SEG_LEN));
+       kfree(conn->persistent_address);
+       kfree(conn->local_ipaddr);
+       /* regular RX path uses back_lock */
+       spin_lock_bh(&session->back_lock);
+       kfifo_in(&session->cmdpool.queue, (void*)&conn->login_task,
+                   sizeof(void*));
+       spin_unlock_bh(&session->back_lock);
+       if (session->leadconn == conn)
+               session->leadconn = NULL;
+       spin_unlock_bh(&session->frwd_lock);
+
+       iscsi_destroy_conn(cls_conn);
+}
+EXPORT_SYMBOL_GPL(iscsi_conn_teardown);
+
+int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
+{
+       struct iscsi_conn *conn = cls_conn->dd_data;
+       struct iscsi_session *session = conn->session;
+
+       if (!session) {
+               iscsi_conn_printk(KERN_ERR, conn,
+                                 "can't start unbound connection\n");
+               return -EPERM;
+       }
+
+       if ((session->imm_data_en || !session->initial_r2t_en) &&
+            session->first_burst > session->max_burst) {
+               iscsi_conn_printk(KERN_INFO, conn, "invalid burst lengths: "
+                                 "first_burst %d max_burst %d\n",
+                                 session->first_burst, session->max_burst);
+               return -EINVAL;
+       }
+
+       if (conn->ping_timeout && !conn->recv_timeout) {
+               iscsi_conn_printk(KERN_ERR, conn, "invalid recv timeout of "
+                                 "zero. Using 5 seconds\n.");
+               conn->recv_timeout = 5;
+       }
+
+       if (conn->recv_timeout && !conn->ping_timeout) {
+               iscsi_conn_printk(KERN_ERR, conn, "invalid ping timeout of "
+                                 "zero. Using 5 seconds.\n");
+               conn->ping_timeout = 5;
+       }
+
+       spin_lock_bh(&session->frwd_lock);
+       conn->c_stage = ISCSI_CONN_STARTED;
+       session->state = ISCSI_STATE_LOGGED_IN;
+       session->queued_cmdsn = session->cmdsn;
+
+       conn->last_recv = jiffies;
+       conn->last_ping = jiffies;
+       if (conn->recv_timeout && conn->ping_timeout)
+               mod_timer(&conn->transport_timer,
+                         jiffies + (conn->recv_timeout * HZ));
+
+       switch(conn->stop_stage) {
+       case STOP_CONN_RECOVER:
+               /*
+                * unblock eh_abort() if it is blocked. re-try all
+                * commands after successful recovery
+                */
+               conn->stop_stage = 0;
+               conn->tmf_state = TMF_INITIAL;
+               session->age++;
+               if (session->age == 16)
+                       session->age = 0;
+               break;
+       case STOP_CONN_TERM:
+               conn->stop_stage = 0;
+               break;
+       default:
+               break;
+       }
+       spin_unlock_bh(&session->frwd_lock);
+
+       iscsi_unblock_session(session->cls_session);
+       wake_up(&conn->ehwait);
+       return 0;
+}
+EXPORT_SYMBOL_GPL(iscsi_conn_start);
+
+static void
+fail_mgmt_tasks(struct iscsi_session *session, struct iscsi_conn *conn)
+{
+       struct iscsi_task *task;
+       int i, state;
+
+       for (i = 0; i < conn->session->cmds_max; i++) {
+               task = conn->session->cmds[i];
+               if (task->sc)
+                       continue;
+
+               if (task->state == ISCSI_TASK_FREE)
+                       continue;
+
+               ISCSI_DBG_SESSION(conn->session,
+                                 "failing mgmt itt 0x%x state %d\n",
+                                 task->itt, task->state);
+               state = ISCSI_TASK_ABRT_SESS_RECOV;
+               if (task->state == ISCSI_TASK_PENDING)
+                       state = ISCSI_TASK_COMPLETED;
+               iscsi_complete_task(task, state);
+
+       }
+}
+
+static void iscsi_start_session_recovery(struct iscsi_session *session,
+                                        struct iscsi_conn *conn, int flag)
+{
+       int old_stop_stage;
+
+       mutex_lock(&session->eh_mutex);
+       spin_lock_bh(&session->frwd_lock);
+       if (conn->stop_stage == STOP_CONN_TERM) {
+               spin_unlock_bh(&session->frwd_lock);
+               mutex_unlock(&session->eh_mutex);
+               return;
+       }
+
+       /*
+        * When this is called for the in_login state, we only want to clean
+        * up the login task and connection. We do not need to block and set
+        * the recovery state again
+        */
+       if (flag == STOP_CONN_TERM)
+               session->state = ISCSI_STATE_TERMINATE;
+       else if (conn->stop_stage != STOP_CONN_RECOVER)
+               session->state = ISCSI_STATE_IN_RECOVERY;
+
+       old_stop_stage = conn->stop_stage;
+       conn->stop_stage = flag;
+       spin_unlock_bh(&session->frwd_lock);
+
+       del_timer_sync(&conn->transport_timer);
+       iscsi_suspend_tx(conn);
+
+       spin_lock_bh(&session->frwd_lock);
+       conn->c_stage = ISCSI_CONN_STOPPED;
+       spin_unlock_bh(&session->frwd_lock);
+
+       /*
+        * for connection level recovery we should not calculate
+        * header digest. conn->hdr_size used for optimization
+        * in hdr_extract() and will be re-negotiated at
+        * set_param() time.
+        */
+       if (flag == STOP_CONN_RECOVER) {
+               conn->hdrdgst_en = 0;
+               conn->datadgst_en = 0;
+               if (session->state == ISCSI_STATE_IN_RECOVERY &&
+                   old_stop_stage != STOP_CONN_RECOVER) {
+                       ISCSI_DBG_SESSION(session, "blocking session\n");
+                       iscsi_block_session(session->cls_session);
+               }
+       }
+
+       /*
+        * flush queues.
+        */
+       spin_lock_bh(&session->frwd_lock);
+       fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED);
+       fail_mgmt_tasks(session, conn);
+       memset(&conn->tmhdr, 0, sizeof(conn->tmhdr));
+       spin_unlock_bh(&session->frwd_lock);
+       mutex_unlock(&session->eh_mutex);
+}
+
+void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
+{
+       struct iscsi_conn *conn = cls_conn->dd_data;
+       struct iscsi_session *session = conn->session;
+
+       switch (flag) {
+       case STOP_CONN_RECOVER:
+       case STOP_CONN_TERM:
+               iscsi_start_session_recovery(session, conn, flag);
+               break;
+       default:
+               iscsi_conn_printk(KERN_ERR, conn,
+                                 "invalid stop flag %d\n", flag);
+       }
+}
+EXPORT_SYMBOL_GPL(iscsi_conn_stop);
+
+int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
+                   struct iscsi_cls_conn *cls_conn, int is_leading)
+{
+       struct iscsi_session *session = cls_session->dd_data;
+       struct iscsi_conn *conn = cls_conn->dd_data;
+
+       spin_lock_bh(&session->frwd_lock);
+       if (is_leading)
+               session->leadconn = conn;
+       spin_unlock_bh(&session->frwd_lock);
+
+       /*
+        * Unblock xmitworker(), Login Phase will pass through.
+        */
+       clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
+       clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
+       return 0;
+}
+EXPORT_SYMBOL_GPL(iscsi_conn_bind);
+
+int iscsi_switch_str_param(char **param, char *new_val_buf)
+{
+       char *new_val;
+
+       if (*param) {
+               if (!strcmp(*param, new_val_buf))
+                       return 0;
+       }
+
+       new_val = kstrdup(new_val_buf, GFP_NOIO);
+       if (!new_val)
+               return -ENOMEM;
+
+       kfree(*param);
+       *param = new_val;
+       return 0;
+}
+EXPORT_SYMBOL_GPL(iscsi_switch_str_param);
+
+int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
+                   enum iscsi_param param, char *buf, int buflen)
+{
+       struct iscsi_conn *conn = cls_conn->dd_data;
+       struct iscsi_session *session = conn->session;
+       int val;
+
+       switch(param) {
+       case ISCSI_PARAM_FAST_ABORT:
+               sscanf(buf, "%d", &session->fast_abort);
+               break;
+       case ISCSI_PARAM_ABORT_TMO:
+               sscanf(buf, "%d", &session->abort_timeout);
+               break;
+       case ISCSI_PARAM_LU_RESET_TMO:
+               sscanf(buf, "%d", &session->lu_reset_timeout);
+               break;
+       case ISCSI_PARAM_TGT_RESET_TMO:
+               sscanf(buf, "%d", &session->tgt_reset_timeout);
+               break;
+       case ISCSI_PARAM_PING_TMO:
+               sscanf(buf, "%d", &conn->ping_timeout);
+               break;
+       case ISCSI_PARAM_RECV_TMO:
+               sscanf(buf, "%d", &conn->recv_timeout);
+               break;
+       case ISCSI_PARAM_MAX_RECV_DLENGTH:
+               sscanf(buf, "%d", &conn->max_recv_dlength);
+               break;
+       case ISCSI_PARAM_MAX_XMIT_DLENGTH:
+               sscanf(buf, "%d", &conn->max_xmit_dlength);
+               break;
+       case ISCSI_PARAM_HDRDGST_EN:
+               sscanf(buf, "%d", &conn->hdrdgst_en);
+               break;
+       case ISCSI_PARAM_DATADGST_EN:
+               sscanf(buf, "%d", &conn->datadgst_en);
+               break;
+       case ISCSI_PARAM_INITIAL_R2T_EN:
+               sscanf(buf, "%d", &session->initial_r2t_en);
+               break;
+       case ISCSI_PARAM_MAX_R2T:
+               sscanf(buf, "%hu", &session->max_r2t);
+               break;
+       case ISCSI_PARAM_IMM_DATA_EN:
+               sscanf(buf, "%d", &session->imm_data_en);
+               break;
+       case ISCSI_PARAM_FIRST_BURST:
+               sscanf(buf, "%d", &session->first_burst);
+               break;
+       case ISCSI_PARAM_MAX_BURST:
+               sscanf(buf, "%d", &session->max_burst);
+               break;
+       case ISCSI_PARAM_PDU_INORDER_EN:
+               sscanf(buf, "%d", &session->pdu_inorder_en);
+               break;
+       case ISCSI_PARAM_DATASEQ_INORDER_EN:
+               sscanf(buf, "%d", &session->dataseq_inorder_en);
+               break;
+       case ISCSI_PARAM_ERL:
+               sscanf(buf, "%d", &session->erl);
+               break;
+       case ISCSI_PARAM_EXP_STATSN:
+               sscanf(buf, "%u", &conn->exp_statsn);
+               break;
+       case ISCSI_PARAM_USERNAME:
+               return iscsi_switch_str_param(&session->username, buf);
+       case ISCSI_PARAM_USERNAME_IN:
+               return iscsi_switch_str_param(&session->username_in, buf);
+       case ISCSI_PARAM_PASSWORD:
+               return iscsi_switch_str_param(&session->password, buf);
+       case ISCSI_PARAM_PASSWORD_IN:
+               return iscsi_switch_str_param(&session->password_in, buf);
+       case ISCSI_PARAM_TARGET_NAME:
+               return iscsi_switch_str_param(&session->targetname, buf);
+       case ISCSI_PARAM_TARGET_ALIAS:
+               return iscsi_switch_str_param(&session->targetalias, buf);
+       case ISCSI_PARAM_TPGT:
+               sscanf(buf, "%d", &session->tpgt);
+               break;
+       case ISCSI_PARAM_PERSISTENT_PORT:
+               sscanf(buf, "%d", &conn->persistent_port);
+               break;
+       case ISCSI_PARAM_PERSISTENT_ADDRESS:
+               return iscsi_switch_str_param(&conn->persistent_address, buf);
+       case ISCSI_PARAM_IFACE_NAME:
+               return iscsi_switch_str_param(&session->ifacename, buf);
+       case ISCSI_PARAM_INITIATOR_NAME:
+               return iscsi_switch_str_param(&session->initiatorname, buf);
+       case ISCSI_PARAM_BOOT_ROOT:
+               return iscsi_switch_str_param(&session->boot_root, buf);
+       case ISCSI_PARAM_BOOT_NIC:
+               return iscsi_switch_str_param(&session->boot_nic, buf);
+       case ISCSI_PARAM_BOOT_TARGET:
+               return iscsi_switch_str_param(&session->boot_target, buf);
+       case ISCSI_PARAM_PORTAL_TYPE:
+               return iscsi_switch_str_param(&session->portal_type, buf);
+       case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
+               return iscsi_switch_str_param(&session->discovery_parent_type,
+                                             buf);
+       case ISCSI_PARAM_DISCOVERY_SESS:
+               sscanf(buf, "%d", &val);
+               session->discovery_sess = !!val;
+               break;
+       case ISCSI_PARAM_LOCAL_IPADDR:
+               return iscsi_switch_str_param(&conn->local_ipaddr, buf);
+       default:
+               return -ENOSYS;
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(iscsi_set_param);
+
+int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
+                           enum iscsi_param param, char *buf)
+{
+       struct iscsi_session *session = cls_session->dd_data;
+       int len;
+
+       switch(param) {
+       case ISCSI_PARAM_FAST_ABORT:
+               len = sprintf(buf, "%d\n", session->fast_abort);
+               break;
+       case ISCSI_PARAM_ABORT_TMO:
+               len = sprintf(buf, "%d\n", session->abort_timeout);
+               break;
+       case ISCSI_PARAM_LU_RESET_TMO:
+               len = sprintf(buf, "%d\n", session->lu_reset_timeout);
+               break;
+       case ISCSI_PARAM_TGT_RESET_TMO:
+               len = sprintf(buf, "%d\n", session->tgt_reset_timeout);
+               break;
+       case ISCSI_PARAM_INITIAL_R2T_EN:
+               len = sprintf(buf, "%d\n", session->initial_r2t_en);
+               break;
+       case ISCSI_PARAM_MAX_R2T:
+               len = sprintf(buf, "%hu\n", session->max_r2t);
+               break;
+       case ISCSI_PARAM_IMM_DATA_EN:
+               len = sprintf(buf, "%d\n", session->imm_data_en);
+               break;
+       case ISCSI_PARAM_FIRST_BURST:
+               len = sprintf(buf, "%u\n", session->first_burst);
+               break;
+       case ISCSI_PARAM_MAX_BURST:
+               len = sprintf(buf, "%u\n", session->max_burst);
+               break;
+       case ISCSI_PARAM_PDU_INORDER_EN:
+               len = sprintf(buf, "%d\n", session->pdu_inorder_en);
+               break;
+       case ISCSI_PARAM_DATASEQ_INORDER_EN:
+               len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
+               break;
+       case ISCSI_PARAM_DEF_TASKMGMT_TMO:
+               len = sprintf(buf, "%d\n", session->def_taskmgmt_tmo);
+               break;
+       case ISCSI_PARAM_ERL:
+               len = sprintf(buf, "%d\n", session->erl);
+               break;
+       case ISCSI_PARAM_TARGET_NAME:
+               len = sprintf(buf, "%s\n", session->targetname);
+               break;
+       case ISCSI_PARAM_TARGET_ALIAS:
+               len = sprintf(buf, "%s\n", session->targetalias);
+               break;
+       case ISCSI_PARAM_TPGT:
+               len = sprintf(buf, "%d\n", session->tpgt);
+               break;
+       case ISCSI_PARAM_USERNAME:
+               len = sprintf(buf, "%s\n", session->username);
+               break;
+       case ISCSI_PARAM_USERNAME_IN:
+               len = sprintf(buf, "%s\n", session->username_in);
+               break;
+       case ISCSI_PARAM_PASSWORD:
+               len = sprintf(buf, "%s\n", session->password);
+               break;
+       case ISCSI_PARAM_PASSWORD_IN:
+               len = sprintf(buf, "%s\n", session->password_in);
+               break;
+       case ISCSI_PARAM_IFACE_NAME:
+               len = sprintf(buf, "%s\n", session->ifacename);
+               break;
+       case ISCSI_PARAM_INITIATOR_NAME:
+               len = sprintf(buf, "%s\n", session->initiatorname);
+               break;
+       case ISCSI_PARAM_BOOT_ROOT:
+               len = sprintf(buf, "%s\n", session->boot_root);
+               break;
+       case ISCSI_PARAM_BOOT_NIC:
+               len = sprintf(buf, "%s\n", session->boot_nic);
+               break;
+       case ISCSI_PARAM_BOOT_TARGET:
+               len = sprintf(buf, "%s\n", session->boot_target);
+               break;
+       case ISCSI_PARAM_AUTO_SND_TGT_DISABLE:
+               len = sprintf(buf, "%u\n", session->auto_snd_tgt_disable);
+               break;
+       case ISCSI_PARAM_DISCOVERY_SESS:
+               len = sprintf(buf, "%u\n", session->discovery_sess);
+               break;
+       case ISCSI_PARAM_PORTAL_TYPE:
+               len = sprintf(buf, "%s\n", session->portal_type);
+               break;
+       case ISCSI_PARAM_CHAP_AUTH_EN:
+               len = sprintf(buf, "%u\n", session->chap_auth_en);
+               break;
+       case ISCSI_PARAM_DISCOVERY_LOGOUT_EN:
+               len = sprintf(buf, "%u\n", session->discovery_logout_en);
+               break;
+       case ISCSI_PARAM_BIDI_CHAP_EN:
+               len = sprintf(buf, "%u\n", session->bidi_chap_en);
+               break;
+       case ISCSI_PARAM_DISCOVERY_AUTH_OPTIONAL:
+               len = sprintf(buf, "%u\n", session->discovery_auth_optional);
+               break;
+       case ISCSI_PARAM_DEF_TIME2WAIT:
+               len = sprintf(buf, "%d\n", session->time2wait);
+               break;
+       case ISCSI_PARAM_DEF_TIME2RETAIN:
+               len = sprintf(buf, "%d\n", session->time2retain);
+               break;
+       case ISCSI_PARAM_TSID:
+               len = sprintf(buf, "%u\n", session->tsid);
+               break;
+       case ISCSI_PARAM_ISID:
+               len = sprintf(buf, "%02x%02x%02x%02x%02x%02x\n",
+                             session->isid[0], session->isid[1],
+                             session->isid[2], session->isid[3],
+                             session->isid[4], session->isid[5]);
+               break;
+       case ISCSI_PARAM_DISCOVERY_PARENT_IDX:
+               len = sprintf(buf, "%u\n", session->discovery_parent_idx);
+               break;
+       case ISCSI_PARAM_DISCOVERY_PARENT_TYPE:
+               if (session->discovery_parent_type)
+                       len = sprintf(buf, "%s\n",
+                                     session->discovery_parent_type);
+               else
+                       len = sprintf(buf, "\n");
+               break;
+       default:
+               return -ENOSYS;
+       }
+
+       return len;
+}
+EXPORT_SYMBOL_GPL(iscsi_session_get_param);
+
+int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
+                             enum iscsi_param param, char *buf)
+{
+       struct sockaddr_in6 *sin6 = NULL;
+       struct sockaddr_in *sin = NULL;
+       int len;
+
+       switch (addr->ss_family) {
+       case AF_INET:
+               sin = (struct sockaddr_in *)addr;
+               break;
+       case AF_INET6:
+               sin6 = (struct sockaddr_in6 *)addr;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       switch (param) {
+       case ISCSI_PARAM_CONN_ADDRESS:
+       case ISCSI_HOST_PARAM_IPADDRESS:
+               if (sin)
+                       len = sprintf(buf, "%pI4\n", &sin->sin_addr.s_addr);
+               else
+                       len = sprintf(buf, "%pI6\n", &sin6->sin6_addr);
+               break;
+       case ISCSI_PARAM_CONN_PORT:
+       case ISCSI_PARAM_LOCAL_PORT:
+               if (sin)
+                       len = sprintf(buf, "%hu\n", be16_to_cpu(sin->sin_port));
+               else
+                       len = sprintf(buf, "%hu\n",
+                                     be16_to_cpu(sin6->sin6_port));
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       return len;
+}
+EXPORT_SYMBOL_GPL(iscsi_conn_get_addr_param);
+
+int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
+                        enum iscsi_param param, char *buf)
+{
+       struct iscsi_conn *conn = cls_conn->dd_data;
+       int len;
+
+       switch(param) {
+       case ISCSI_PARAM_PING_TMO:
+               len = sprintf(buf, "%u\n", conn->ping_timeout);
+               break;
+       case ISCSI_PARAM_RECV_TMO:
+               len = sprintf(buf, "%u\n", conn->recv_timeout);
+               break;
+       case ISCSI_PARAM_MAX_RECV_DLENGTH:
+               len = sprintf(buf, "%u\n", conn->max_recv_dlength);
+               break;
+       case ISCSI_PARAM_MAX_XMIT_DLENGTH:
+               len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
+               break;
+       case ISCSI_PARAM_HDRDGST_EN:
+               len = sprintf(buf, "%d\n", conn->hdrdgst_en);
+               break;
+       case ISCSI_PARAM_DATADGST_EN:
+               len = sprintf(buf, "%d\n", conn->datadgst_en);
+               break;
+       case ISCSI_PARAM_IFMARKER_EN:
+               len = sprintf(buf, "%d\n", conn->ifmarker_en);
+               break;
+       case ISCSI_PARAM_OFMARKER_EN:
+               len = sprintf(buf, "%d\n", conn->ofmarker_en);
+               break;
+       case ISCSI_PARAM_EXP_STATSN:
+               len = sprintf(buf, "%u\n", conn->exp_statsn);
+               break;
+       case ISCSI_PARAM_PERSISTENT_PORT:
+               len = sprintf(buf, "%d\n", conn->persistent_port);
+               break;
+       case ISCSI_PARAM_PERSISTENT_ADDRESS:
+               len = sprintf(buf, "%s\n", conn->persistent_address);
+               break;
+       case ISCSI_PARAM_STATSN:
+               len = sprintf(buf, "%u\n", conn->statsn);
+               break;
+       case ISCSI_PARAM_MAX_SEGMENT_SIZE:
+               len = sprintf(buf, "%u\n", conn->max_segment_size);
+               break;
+       case ISCSI_PARAM_KEEPALIVE_TMO:
+               len = sprintf(buf, "%u\n", conn->keepalive_tmo);
+               break;
+       case ISCSI_PARAM_LOCAL_PORT:
+               len = sprintf(buf, "%u\n", conn->local_port);
+               break;
+       case ISCSI_PARAM_TCP_TIMESTAMP_STAT:
+               len = sprintf(buf, "%u\n", conn->tcp_timestamp_stat);
+               break;
+       case ISCSI_PARAM_TCP_NAGLE_DISABLE:
+               len = sprintf(buf, "%u\n", conn->tcp_nagle_disable);
+               break;
+       case ISCSI_PARAM_TCP_WSF_DISABLE:
+               len = sprintf(buf, "%u\n", conn->tcp_wsf_disable);
+               break;
+       case ISCSI_PARAM_TCP_TIMER_SCALE:
+               len = sprintf(buf, "%u\n", conn->tcp_timer_scale);
+               break;
+       case ISCSI_PARAM_TCP_TIMESTAMP_EN:
+               len = sprintf(buf, "%u\n", conn->tcp_timestamp_en);
+               break;
+       case ISCSI_PARAM_IP_FRAGMENT_DISABLE:
+               len = sprintf(buf, "%u\n", conn->fragment_disable);
+               break;
+       case ISCSI_PARAM_IPV4_TOS:
+               len = sprintf(buf, "%u\n", conn->ipv4_tos);
+               break;
+       case ISCSI_PARAM_IPV6_TC:
+               len = sprintf(buf, "%u\n", conn->ipv6_traffic_class);
+               break;
+       case ISCSI_PARAM_IPV6_FLOW_LABEL:
+               len = sprintf(buf, "%u\n", conn->ipv6_flow_label);
+               break;
+       case ISCSI_PARAM_IS_FW_ASSIGNED_IPV6:
+               len = sprintf(buf, "%u\n", conn->is_fw_assigned_ipv6);
+               break;
+       case ISCSI_PARAM_TCP_XMIT_WSF:
+               len = sprintf(buf, "%u\n", conn->tcp_xmit_wsf);
+               break;
+       case ISCSI_PARAM_TCP_RECV_WSF:
+               len = sprintf(buf, "%u\n", conn->tcp_recv_wsf);
+               break;
+       case ISCSI_PARAM_LOCAL_IPADDR:
+               len = sprintf(buf, "%s\n", conn->local_ipaddr);
+               break;
+       default:
+               return -ENOSYS;
+       }
+
+       return len;
+}
+EXPORT_SYMBOL_GPL(iscsi_conn_get_param);
+
+int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
+                        char *buf)
+{
+       struct iscsi_host *ihost = shost_priv(shost);
+       int len;
+
+       switch (param) {
+       case ISCSI_HOST_PARAM_NETDEV_NAME:
+               len = sprintf(buf, "%s\n", ihost->netdev);
+               break;
+       case ISCSI_HOST_PARAM_HWADDRESS:
+               len = sprintf(buf, "%s\n", ihost->hwaddress);
+               break;
+       case ISCSI_HOST_PARAM_INITIATOR_NAME:
+               len = sprintf(buf, "%s\n", ihost->initiatorname);
+               break;
+       default:
+               return -ENOSYS;
+       }
+
+       return len;
+}
+EXPORT_SYMBOL_GPL(iscsi_host_get_param);
+
+int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
+                        char *buf, int buflen)
+{
+       struct iscsi_host *ihost = shost_priv(shost);
+
+       switch (param) {
+       case ISCSI_HOST_PARAM_NETDEV_NAME:
+               return iscsi_switch_str_param(&ihost->netdev, buf);
+       case ISCSI_HOST_PARAM_HWADDRESS:
+               return iscsi_switch_str_param(&ihost->hwaddress, buf);
+       case ISCSI_HOST_PARAM_INITIATOR_NAME:
+               return iscsi_switch_str_param(&ihost->initiatorname, buf);
+       default:
+               return -ENOSYS;
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(iscsi_host_set_param);
+
+MODULE_AUTHOR("Mike Christie");
+MODULE_DESCRIPTION("iSCSI library functions");
+MODULE_LICENSE("GPL");