diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
index 7983281..1296a10 100644
--- a/drivers/scsi/libiscsi.c
+++ b/drivers/scsi/libiscsi.c
@@ -93,9 +93,31 @@ inline void iscsi_conn_queue_work(struct iscsi_conn *conn)
 }
 EXPORT_SYMBOL_GPL(iscsi_conn_queue_work);
 
-static void __iscsi_update_cmdsn(struct iscsi_session *session,
-				 uint32_t exp_cmdsn, uint32_t max_cmdsn)
+static int iscsi_check_cmdsn_window_closed(struct iscsi_conn *conn)
+{
+	struct iscsi_session *session = conn->session;
+
+	/* make sure we see the updated SNs */
+	smp_rmb();
+	/*
+	 * Check for iSCSI window and take care of CmdSN wrap-around
+	 */
+	if (!iscsi_sna_lte(session->cmdsn, session->max_cmdsn)) {
+		ISCSI_DBG_SESSION(session, "iSCSI CmdSN closed. ExpCmdSn "
+				  "%u MaxCmdSN %u CmdSN %u\n",
+				  session->exp_cmdsn, session->max_cmdsn,
+				  session->cmdsn);
+		return -ENOSPC;
+	}
+	return 0;
+}
+
+static void __iscsi_update_cmdsn(struct iscsi_conn *conn, uint32_t exp_cmdsn,
+				 uint32_t max_cmdsn)
 {
+	struct iscsi_session *session = conn->session;
+	bool win_closed = false;
+
 	/*
 	 * standard specifies this check for when to update expected and
 	 * max sequence numbers
@@ -108,13 +130,22 @@ static void __iscsi_update_cmdsn(struct iscsi_session *session,
 		session->exp_cmdsn = exp_cmdsn;
 
 	if (max_cmdsn != session->max_cmdsn &&
-	    !iscsi_sna_lt(max_cmdsn, session->max_cmdsn))
+	    !iscsi_sna_lt(max_cmdsn, session->max_cmdsn)) {
+
+		if (iscsi_check_cmdsn_window_closed(conn))
+			win_closed = true;
+
 		session->max_cmdsn = max_cmdsn;
+		/* make sure we see the open window from the xmit/queue path */
+		smp_wmb();
+		if (win_closed)
+			session->win_opened = true;
+	}
 }
 
-void iscsi_update_cmdsn(struct iscsi_session *session, struct iscsi_nopin *hdr)
+void iscsi_update_cmdsn(struct iscsi_conn *conn, struct iscsi_nopin *hdr)
 {
-	__iscsi_update_cmdsn(session, be32_to_cpu(hdr->exp_cmdsn),
+	__iscsi_update_cmdsn(conn, be32_to_cpu(hdr->exp_cmdsn),
 			     be32_to_cpu(hdr->max_cmdsn));
 }
 EXPORT_SYMBOL_GPL(iscsi_update_cmdsn);
@@ -424,14 +455,15 @@ static int iscsi_prep_scsi_cmd_pdu(struct iscsi_task *task)
 
 	task->state = ISCSI_TASK_RUNNING;
 	session->cmdsn++;
+	/* make sure window checkers see the update */
+	smp_wmb();
 
 	conn->scsicmd_pdus_cnt++;
 	ISCSI_DBG_SESSION(session, "iscsi prep [%s cid %d sc %p cdb 0x%x "
 			  "itt 0x%x len %d cmdsn %d win %d]\n",
 			  sc->sc_data_direction == DMA_TO_DEVICE ?
 			  "write" : "read", conn->id, sc, sc->cmnd[0],
-			  task->itt, transfer_length,
-			  session->cmdsn,
+			  task->itt, transfer_length, session->cmdsn,
 			  session->max_cmdsn - session->exp_cmdsn + 1);
 	return 0;
 }
@@ -465,6 +497,11 @@ static void iscsi_free_task(struct iscsi_task *task)
 
 	kfifo_in(&session->cmdpool.queue, (void*)&task, sizeof(void*));
 
+	if (session->win_opened && !work_pending(&conn->xmitwork)) {
+		session->win_opened = false;
+		iscsi_conn_queue_work(conn);
+	}
+
 	if (sc) {
 		/* SCSI eh reuses commands to verify us */
 		sc->SCp.ptr = NULL;
@@ -549,7 +586,7 @@ void iscsi_complete_scsi_task(struct iscsi_task *task,
 	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_update_cmdsn(conn, exp_cmdsn, max_cmdsn);
 	iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 }
 EXPORT_SYMBOL_GPL(iscsi_complete_scsi_task);
@@ -613,11 +650,6 @@ static void fail_scsi_task(struct iscsi_task *task, int err)
 	}
 
 	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)
@@ -658,10 +690,8 @@ static int iscsi_prep_mgmt_task(struct iscsi_conn *conn,
 		 * 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++;
+		    !(hdr->opcode & ISCSI_OP_IMMEDIATE))
 			session->cmdsn++;
-		}
 	}
 
 	if (session->tt->init_task && session->tt->init_task(task))
@@ -820,7 +850,7 @@ static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 	struct iscsi_session *session = conn->session;
 	struct scsi_cmnd *sc = task->sc;
 
-	iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
+	iscsi_update_cmdsn(conn, (struct iscsi_nopin*)rhdr);
 	conn->exp_statsn = be32_to_cpu(rhdr->statsn) + 1;
 
 	sc->result = (DID_OK << 16) | rhdr->cmd_status;
@@ -920,7 +950,7 @@ static void iscsi_scsi_cmd_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 	if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
 		return;
 
-	iscsi_update_cmdsn(conn->session, (struct iscsi_nopin *)hdr);
+	iscsi_update_cmdsn(conn, (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 |
@@ -1172,7 +1202,7 @@ int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 			  opcode, conn->id, itt, datalen);
 
 	if (itt == ~0U) {
-		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
+		iscsi_update_cmdsn(conn, (struct iscsi_nopin*)hdr);
 
 		switch(opcode) {
 		case ISCSI_OP_NOOP_IN:
@@ -1240,7 +1270,7 @@ int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 		iscsi_data_in_rsp(conn, hdr, task);
 		break;
 	case ISCSI_OP_LOGOUT_RSP:
-		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
+		iscsi_update_cmdsn(conn, (struct iscsi_nopin*)hdr);
 		if (datalen) {
 			rc = ISCSI_ERR_PROTO;
 			break;
@@ -1249,14 +1279,14 @@ int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 		goto recv_pdu;
 	case ISCSI_OP_LOGIN_RSP:
 	case ISCSI_OP_TEXT_RSP:
-		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
+		iscsi_update_cmdsn(conn, (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);
+		iscsi_update_cmdsn(conn, (struct iscsi_nopin*)hdr);
 		if (datalen) {
 			rc = ISCSI_ERR_PROTO;
 			break;
@@ -1266,7 +1296,7 @@ int __iscsi_complete_pdu(struct iscsi_conn *conn, struct iscsi_hdr *hdr,
 		iscsi_complete_task(task, ISCSI_TASK_COMPLETED);
 		break;
 	case ISCSI_OP_NOOP_IN:
-		iscsi_update_cmdsn(session, (struct iscsi_nopin*)hdr);
+		iscsi_update_cmdsn(conn, (struct iscsi_nopin*)hdr);
 		if (hdr->ttt != cpu_to_be32(ISCSI_RESERVED_TAG) || datalen) {
 			rc = ISCSI_ERR_PROTO;
 			break;
@@ -1416,23 +1446,6 @@ void iscsi_conn_failure(struct iscsi_conn *conn, enum iscsi_err 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, bool has_extra_ref)
 {
 	struct iscsi_task *task = conn->task;
@@ -1564,6 +1577,10 @@ static int iscsi_data_xmit(struct iscsi_conn *conn)
 
 	/* process pending command queue */
 	while (!list_empty(&conn->cmdqueue)) {
+		rc = iscsi_check_cmdsn_window_closed(conn);
+		if (rc)
+			goto done;
+
 		task = list_entry(conn->cmdqueue.next, struct iscsi_task,
 				  running);
 		list_del_init(&task->running);
@@ -1750,11 +1767,6 @@ int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
 		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;
@@ -1762,6 +1774,11 @@ int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
 	}
 
 	if (!ihost->workq) {
+		if (iscsi_check_cmdsn_window_closed(conn)) {
+			reason = FAILURE_WINDOW_CLOSED;
+			goto prepd_reject;
+		}
+
 		reason = iscsi_prep_scsi_cmd_pdu(task);
 		if (reason) {
 			if (reason == -ENOMEM ||  reason == -EACCES) {
@@ -1782,7 +1799,6 @@ int iscsi_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *sc)
 		iscsi_conn_queue_work(conn);
 	}
 
-	session->queued_cmdsn++;
 	spin_unlock_bh(&session->frwd_lock);
 	return 0;
 
@@ -2831,7 +2847,7 @@ struct iscsi_cls_session *
 	session->abort_timeout = 10;
 	session->scsi_cmds_max = scsi_cmds;
 	session->cmds_max = total_cmds;
-	session->queued_cmdsn = session->cmdsn = initial_cmdsn;
+	session->cmdsn = initial_cmdsn;
 	session->exp_cmdsn = initial_cmdsn + 1;
 	session->max_cmdsn = initial_cmdsn + 1;
 	session->max_r2t = 1;
@@ -3063,7 +3079,6 @@ int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
 	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;
diff --git a/drivers/scsi/libiscsi_tcp.c b/drivers/scsi/libiscsi_tcp.c
index 73b7556..916148c 100644
--- a/drivers/scsi/libiscsi_tcp.c
+++ b/drivers/scsi/libiscsi_tcp.c
@@ -496,7 +496,7 @@ static int iscsi_tcp_data_in(struct iscsi_conn *conn, struct iscsi_task *task)
 	 * is status.
 	 */
 	if (!(rhdr->flags & ISCSI_FLAG_DATA_STATUS))
-		iscsi_update_cmdsn(conn->session, (struct iscsi_nopin*)rhdr);
+		iscsi_update_cmdsn(conn, (struct iscsi_nopin*)rhdr);
 
 	if (tcp_conn->in.datalen == 0)
 		return 0;
@@ -563,7 +563,7 @@ static int iscsi_tcp_r2t_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr)
 	tcp_conn = conn->dd_data;
 	rhdr = (struct iscsi_r2t_rsp *)tcp_conn->in.hdr;
 	/* fill-in new R2T associated with the task */
-	iscsi_update_cmdsn(session, (struct iscsi_nopin*)rhdr);
+	iscsi_update_cmdsn(conn, (struct iscsi_nopin*)rhdr);
 	spin_unlock(&session->back_lock);
 
 	if (tcp_conn->in.datalen) {
diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h
index 44a9554..b649ec5 100644
--- a/include/scsi/libiscsi.h
+++ b/include/scsi/libiscsi.h
@@ -275,9 +275,7 @@ struct iscsi_session {
 	uint32_t		cmdsn;
 	uint32_t		exp_cmdsn;
 	uint32_t		max_cmdsn;
-
-	/* This tracks the reqs queued into the initiator */
-	uint32_t		queued_cmdsn;
+	bool			win_opened;
 
 	/* configuration */
 	int			abort_timeout;
@@ -329,8 +327,8 @@ struct iscsi_session {
 	 * but not vice versa.
 	 */
 	spinlock_t		frwd_lock;	/* protects session state, *
-						 * cmdsn, queued_cmdsn     *
-						 * session resources:      *
+						 * cmdsn and session       *
+						 * resources:              *
 						 * - cmdpool kfifo_out ,   *
 						 * - mgmtpool, queues	   */
 	spinlock_t		back_lock;	/* protects cmdsn_exp      *
@@ -440,7 +438,7 @@ extern int iscsi_conn_get_addr_param(struct sockaddr_storage *addr,
 /*
  * pdu and task processing
  */
-extern void iscsi_update_cmdsn(struct iscsi_session *, struct iscsi_nopin *);
+extern void iscsi_update_cmdsn(struct iscsi_conn *, struct iscsi_nopin *);
 extern void iscsi_prep_data_out_pdu(struct iscsi_task *task,
 				    struct iscsi_r2t_info *r2t,
 				    struct iscsi_data *hdr);
