From c29b9a2aae92c0843e7e23171c81eb0d3e740788 Mon Sep 17 00:00:00 2001
From: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Date: Thu, 3 Feb 2011 19:08:16 +1100
Subject: [PATCH] Add a new "iscsi_queue_length()" which will tell us how many
 commands are in flight at the moment. Aside from commands, we also consider
 the "has not yet connected completely" as being an i/o.

When this command returns 0 it means we are connected ant the iscsi connection is idle, with no commands in flight.

KVM needs a function to detect idleness like this for its block layer io_flush
function.
---
 include/iscsi.h |  4 ++++
 lib/socket.c    | 19 +++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/include/iscsi.h b/include/iscsi.h
index a3cbf54..11e014c 100644
--- a/include/iscsi.h
+++ b/include/iscsi.h
@@ -47,6 +47,10 @@ int iscsi_which_events(struct iscsi_context *iscsi);
  * file descriptor.
  */
 int iscsi_service(struct iscsi_context *iscsi, int revents);
+/*
+ * How many commands are in flight.
+ */
+int iscsi_queue_length(struct iscsi_context *iscsi);
 
 
 
diff --git a/lib/socket.c b/lib/socket.c
index e6df382..4ed6e97 100644
--- a/lib/socket.c
+++ b/lib/socket.c
@@ -188,6 +188,25 @@ iscsi_which_events(struct iscsi_context *iscsi)
 	return events;
 }
 
+int
+iscsi_queue_length(struct iscsi_context *iscsi)
+{
+	int i = 0;
+	struct iscsi_pdu *pdu;
+
+	for (pdu = iscsi->outqueue; pdu; pdu = pdu->next) {
+		i++;
+	}
+	for (pdu = iscsi->waitpdu; pdu; pdu = pdu->next) {
+		i++;
+	}
+	if (iscsi->is_connected == 0) {
+		i++;
+	}
+
+	return i;
+}
+
 static int
 iscsi_read_from_socket(struct iscsi_context *iscsi)
 {