iscsi-target: Add iSCSI fabric support for target v4.1

The Linux-iSCSI.org target module is a full featured in-kernel
software implementation of iSCSI target mode (RFC-3720) for the
current WIP mainline target v4.1 infrastructure code for the v3.1
kernel.  More information can be found here:

http://linux-iscsi.org/wiki/ISCSI

This includes support for:

   * RFC-3720 defined request / response state machines and support for
     all defined iSCSI operation codes from Section 10.2.1.2 using libiscsi
     include/scsi/iscsi_proto.h PDU definitions
   * Target v4.1 compatible control plane using the generic layout in
     target_core_fabric_configfs.c and fabric dependent attributes
     within /sys/kernel/config/target/iscsi/ subdirectories.
   * Target v4.1 compatible iSCSI statistics based on RFC-4544 (iSCSI MIBS)
   * Support for IPv6 and IPv4 network portals in M:N mapping to TPGs
   * iSCSI Error Recovery Hierarchy support
   * Per iSCSI connection RX/TX thread pair scheduling affinity
   * crc32c + crc32c_intel SSEv4 instruction offload support using libcrypto
   * CHAP Authentication support using libcrypto
   * Conversion to use internal SGl allocation with iscsit_alloc_buffs() ->
     transport_generic_map_mem_to_cmd()

(nab: Fix iscsi_proto.h struct scsi_lun usage from linux-next in commit:
      iscsi: Use struct scsi_lun in iscsi structs instead of u8[8])
(nab: Fix 32-bit compile warnings)

Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andy Grover <agrover@redhat.com>
Acked-by: Roland Dreier <roland@kernel.org>
Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org>

1 files changed, 87 insertions, 0 deletions

diff --git a/drivers/target/iscsi/iscsi_target_device.c b/drivers/target/iscsi/iscsi_target_device.c
new file mode 100644
index 000000000000..a19fa5eea88e
--- /dev/null
+++ b/drivers/target/iscsi/iscsi_target_device.c
@@ -0,0 +1,87 @@
+/*******************************************************************************
+ * 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 <nab@linux-iscsi.org>
+ *
+ * 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_device.h>
+#include <target/target_core_transport.h>
+
+#include "iscsi_target_core.h"
+#include "iscsi_target_device.h"
+#include "iscsi_target_tpg.h"
+#include "iscsi_target_util.h"
+
+int iscsit_get_lun_for_tmr(
+	struct iscsi_cmd *cmd,
+	u64 lun)
+{
+	u32 unpacked_lun = scsilun_to_int((struct scsi_lun *)&lun);
+
+	return transport_lookup_tmr_lun(&cmd->se_cmd, unpacked_lun);
+}
+
+int iscsit_get_lun_for_cmd(
+	struct iscsi_cmd *cmd,
+	unsigned char *cdb,
+	u64 lun)
+{
+	u32 unpacked_lun = scsilun_to_int((struct scsi_lun *)&lun);
+
+	return transport_lookup_cmd_lun(&cmd->se_cmd, unpacked_lun);
+}
+
+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);
+}