iscsi_target_device.c

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/*******************************************************************************
 * This file contains the iSCSI Virtual Device and Disk Transport
 * agnostic related functions.
 *
 \u00a9 Copyright 2007-2011 RisingTide Systems LLC.
 *
 * Licensed to the Linux Foundation under the General Public License (GPL) version 2.
 *
 * Author: Nicholas A. Bellinger <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 ******************************************************************************/

#include <scsi/scsi_device.h>
#include <target/target_core_base.h>
#include <target/target_core_fabric.h>

#include "iscsi_target_core.h"
#include "iscsi_target_device.h"
#include "iscsi_target_tpg.h"
#include "iscsi_target_util.h"

void iscsit_determine_maxcmdsn(struct iscsi_session *sess)
{
    struct se_node_acl *se_nacl;

    /*
     * This is a discovery session, the single queue slot was already
     * assigned in iscsi_login_zero_tsih().  Since only Logout and
     * Text Opcodes are allowed during discovery we do not have to worry
     * about the HBA's queue depth here.
     */
    if (sess->sess_ops->SessionType)
        return;

    se_nacl = sess->se_sess->se_node_acl;

    /*
     * This is a normal session, set the Session's CmdSN window to the
     * struct se_node_acl->queue_depth.  The value in struct se_node_acl->queue_depth
     * has already been validated as a legal value in
     * core_set_queue_depth_for_node().
     */
    sess->cmdsn_window = se_nacl->queue_depth;
    sess->max_cmd_sn = (sess->max_cmd_sn + se_nacl->queue_depth) - 1;
}

void iscsit_increment_maxcmdsn(struct iscsi_cmd *cmd, struct iscsi_session *sess)
{
    if (cmd->immediate_cmd || cmd->maxcmdsn_inc)
        return;

    cmd->maxcmdsn_inc = 1;

    mutex_lock(&sess->cmdsn_mutex);
    sess->max_cmd_sn += 1;
    pr_debug("Updated MaxCmdSN to 0x%08x\n", sess->max_cmd_sn);
    mutex_unlock(&sess->cmdsn_mutex);
}