IB/iser: Use libiscsi passthrough mode

libiscsi passthrough mode invokes the transport xmit calls directly
without first going through an internal queue, unlike the other mode,
which uses a queue and a xmitworker thread.  Now that the "cant_sleep"
prerequisite of iscsi_host_alloc is met, move to use it.  Handling
xmit errors is now done by the passthrough flow of libiscsi.  Since
the queue/worker aren't used in this mode, the code that schedules the
xmitworker is removed.

Signed-off-by: Or Gerlitz <ogerlitz@voltaire.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/ulp/iser/iscsi_iser.c b/drivers/infiniband/ulp/iser/iscsi_iser.c
index 331147b..71237f8f 100644
--- a/drivers/infiniband/ulp/iser/iscsi_iser.c
+++ b/drivers/infiniband/ulp/iser/iscsi_iser.c
@@ -190,7 +190,7 @@
 {
 	int error = 0;
 
-	iser_dbg("task deq [cid %d itt 0x%x]\n", conn->id, task->itt);
+	iser_dbg("mtask xmit [cid %d itt 0x%x]\n", conn->id, task->itt);
 
 	error = iser_send_control(conn, task);
 
@@ -200,9 +200,6 @@
 	 * - if yes, the task is recycled at iscsi_complete_pdu
 	 * - if no,  the task is recycled at iser_snd_completion
 	 */
-	if (error && error != -ENOBUFS)
-		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
-
 	return error;
 }
 
@@ -254,7 +251,7 @@
 			   task->imm_count, task->unsol_r2t.data_length);
 	}
 
-	iser_dbg("task deq [cid %d itt 0x%x]\n",
+	iser_dbg("ctask xmit [cid %d itt 0x%x]\n",
 		   conn->id, task->itt);
 
 	/* Send the cmd PDU */
@@ -270,8 +267,6 @@
 		error = iscsi_iser_task_xmit_unsol_data(conn, task);
 
  iscsi_iser_task_xmit_exit:
-	if (error && error != -ENOBUFS)
-		iscsi_conn_failure(conn, ISCSI_ERR_CONN_FAILED);
 	return error;
 }
 
@@ -423,7 +418,7 @@
 	struct Scsi_Host *shost;
 	struct iser_conn *ib_conn;
 
-	shost = iscsi_host_alloc(&iscsi_iser_sht, 0, 1);
+	shost = iscsi_host_alloc(&iscsi_iser_sht, 0, 0);
 	if (!shost)
 		return NULL;
 	shost->transportt = iscsi_iser_scsi_transport;