LXR linux/drivers/target/iscsi/iscsi_target

   1/*******************************************************************************
   2 * This file contains the iSCSI Virtual Device and Disk Transport
   3 * agnostic related functions.
   4 *
   5 * (c) Copyright 2007-2013 Datera, Inc.
   6 *
   7 * Author: Nicholas A. Bellinger <nab@linux-iscsi.org>
   8 *
   9 * This program is free software; you can redistribute it and/or modify
  10 * it under the terms of the GNU General Public License as published by
  11 * the Free Software Foundation; either version 2 of the License, or
  12 * (at your option) any later version.
  13 *
  14 * This program is distributed in the hope that it will be useful,
  15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 * GNU General Public License for more details.
  18 ******************************************************************************/
  19
  20#include <scsi/scsi_device.h>
  21#include <target/target_core_base.h>
  22#include <target/target_core_fabric.h>
  23
  24#include <target/iscsi/iscsi_target_core.h>
  25#include "iscsi_target_device.h"
  26#include "iscsi_target_tpg.h"
  27#include "iscsi_target_util.h"
  28
  29void iscsit_determine_maxcmdsn(struct iscsi_session *sess)
  30{
  31        struct se_node_acl *se_nacl;
  32
  33        /*
  34         * This is a discovery session, the single queue slot was already
  35         * assigned in iscsi_login_zero_tsih().  Since only Logout and
  36         * Text Opcodes are allowed during discovery we do not have to worry
  37         * about the HBA's queue depth here.
  38         */
  39        if (sess->sess_ops->SessionType)
  40                return;
  41
  42        se_nacl = sess->se_sess->se_node_acl;
  43
  44        /*
  45         * This is a normal session, set the Session's CmdSN window to the
  46         * struct se_node_acl->queue_depth.  The value in struct se_node_acl->queue_depth
  47         * has already been validated as a legal value in
  48         * core_set_queue_depth_for_node().
  49         */
  50        sess->cmdsn_window = se_nacl->queue_depth;
  51        atomic_add(se_nacl->queue_depth - 1, &sess->max_cmd_sn);
  52}
  53
  54void iscsit_increment_maxcmdsn(struct iscsi_cmd *cmd, struct iscsi_session *sess)
  55{
  56        u32 max_cmd_sn;
  57
  58        if (cmd->immediate_cmd || cmd->maxcmdsn_inc)
  59                return;
  60
  61        cmd->maxcmdsn_inc = 1;
  62
  63        max_cmd_sn = atomic_inc_return(&sess->max_cmd_sn);
  64        pr_debug("Updated MaxCmdSN to 0x%08x\n", max_cmd_sn);
  65}
  66EXPORT_SYMBOL(iscsit_increment_maxcmdsn);
  67