[PATCH] Disable NOP-IN and adjust state for closed conn

[Anton Kovalenko <Anton.Kovalenko@acronis.com>]

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I'm attaching the patch fixing one more problem noticed with non-zero nop_interval:

There is a couple of problems when a connection is closed by
iscsi_tcp_nop_work_handler, and there are uncompleted scsi commands for
that connection:

1) usr/iscsi/iscsid.c:iscsi_scsi_cmd_done assumes that a closed connection
has .state == STATE_CLOSE. The assumption fails if the connection is
closed not as a reaction to STATE_CLOSE, but by a raw conn_close call
outside of rx/tx handlers (like it happens for unanswered NOP-INs).
This commit takes care to set .state = STATE_CLOSE in ep_close callback,
so incomplete scsi commands will be freed on completion.

2) the connection doesn't go away from iscsi_tcp_conn_list until its
refcount reaches zero (see iscsi_tcp_release). It makes
iscsi_tcp_nop_work_handler call conn_close for the same connection
repeatedly, as long as it has incomplete scsi commands (hence non-zero
refcount). This commit zeroes out nop_interval for closed connections,
so next iscsi_tcp_nop_work_handler calls won't try to close the
connection any more.

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From ac1b732b612fe2c188dcc2441e5dd247d3452836 Mon Sep 17 00:00:00 2001
From: Anton Kovalenko <anton.kovalenko@acronis.com>
Date: Tue, 30 Aug 2016 19:02:51 +0300
Subject: [PATCH] Disable NOP-IN and adjust state for closed conn

There is a couple of problems when a connection is closed by
iscsi_tcp_nop_work_handler, and there are uncompleted scsi commands for
that connection:

1) usr/iscsi/iscsid.c:iscsi_scsi_cmd_done assumes that a closed connection
has .state == STATE_CLOSE. The assumption fails if the connection is
closed not as a reaction to STATE_CLOSE, but by a raw conn_close call
outside of rx/tx handlers (like it happens for unanswered NOP-INs).
This commit takes care to set .state = STATE_CLOSE in ep_close callback,
so incomplete scsi commands will be freed on completion.

2) the connection doesn't go away from iscsi_tcp_conn_list until its
refcount reaches zero (see iscsi_tcp_release). It makes
iscsi_tcp_nop_work_handler call conn_close for the same connection
repeatedly, as long as it has incomplete scsi commands (hence non-zero
refcount). This commit zeroes out nop_interval for closed connections,
so next iscsi_tcp_nop_work_handler calls won't try to close the
connection any more.
---
 usr/iscsi/iscsi_tcp.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/usr/iscsi/iscsi_tcp.c b/usr/iscsi/iscsi_tcp.c
index 4cc2cf4..536f22e 100644
--- a/usr/iscsi/iscsi_tcp.c
+++ b/usr/iscsi/iscsi_tcp.c
@@ -508,6 +508,8 @@ static size_t iscsi_tcp_close(struct iscsi_connection *conn)
 	struct iscsi_tcp_connection *tcp_conn = TCP_CONN(conn);
 
 	tgt_event_del(tcp_conn->fd);
+	conn->state = STATE_CLOSE;
+	tcp_conn->nop_interval = 0;
 	return 0;
 }
 
-- 
2.9.3