drivers/target/iscsi/iscsi_target_device.c

   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 "iscsi_target_core.h"
  25 #include "iscsi_target_device.h"
  26 #include "iscsi_target_tpg.h"
  27 #include "iscsi_target_util.h"
  28
  29 void 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         sess->max_cmd_sn = (sess->max_cmd_sn + se_nacl->queue_depth) - 1;
  52 }
  53
  54 void iscsit_increment_maxcmdsn(struct iscsi_cmd *cmd, struct iscsi_session *sess)
  55 {
  56         if (cmd->immediate_cmd || cmd->maxcmdsn_inc)
  57                 return;
  58
  59         cmd->maxcmdsn_inc = 1;
  60
  61         mutex_lock(&sess->cmdsn_mutex);
  62         sess->max_cmd_sn += 1;
  63         pr_debug("Updated MaxCmdSN to 0x%08x\n", sess->max_cmd_sn);
  64         mutex_unlock(&sess->cmdsn_mutex);
  65 }
  66 EXPORT_SYMBOL(iscsit_increment_maxcmdsn);