1 /*******************************************************************************
2  * This file contains the iSCSI Virtual Device and Disk Transport
3  * agnostic related functions.
4  *
5  \u00a9 Copyright 2007-2011 RisingTide Systems LLC.
6  *
7  * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
8  *
9  * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
19  * GNU General Public License for more details.
20  ******************************************************************************/
21 
22 #include <scsi/scsi_device.h>
23 #include <target/target_core_base.h>
24 #include <target/target_core_fabric.h>
25 
26 #include "iscsi_target_core.h"
27 #include "iscsi_target_device.h"
28 #include "iscsi_target_tpg.h"
29 #include "iscsi_target_util.h"
30 
31 void iscsit_determine_maxcmdsn(struct iscsi_session *sess)
32 {
33 	struct se_node_acl *se_nacl;
34 
35 	/*
36 	 * This is a discovery session, the single queue slot was already
37 	 * assigned in iscsi_login_zero_tsih().  Since only Logout and
38 	 * Text Opcodes are allowed during discovery we do not have to worry
39 	 * about the HBA's queue depth here.
40 	 */
41 	if (sess->sess_ops->SessionType)
42 		return;
43 
44 	se_nacl = sess->se_sess->se_node_acl;
45 
46 	/*
47 	 * This is a normal session, set the Session's CmdSN window to the
48 	 * struct se_node_acl->queue_depth.  The value in struct se_node_acl->queue_depth
49 	 * has already been validated as a legal value in
50 	 * core_set_queue_depth_for_node().
51 	 */
52 	sess->cmdsn_window = se_nacl->queue_depth;
53 	sess->max_cmd_sn = (sess->max_cmd_sn + se_nacl->queue_depth) - 1;
54 }
55 
56 void iscsit_increment_maxcmdsn(struct iscsi_cmd *cmd, struct iscsi_session *sess)
57 {
58 	if (cmd->immediate_cmd || cmd->maxcmdsn_inc)
59 		return;
60 
61 	cmd->maxcmdsn_inc = 1;
62 
63 	mutex_lock(&sess->cmdsn_mutex);
64 	sess->max_cmd_sn += 1;
65 	pr_debug("Updated MaxCmdSN to 0x%08x\n", sess->max_cmd_sn);
66 	mutex_unlock(&sess->cmdsn_mutex);
67 }
68