Message-Id: <1232612686.1274.534.camel@haakon2.linux-iscsi.org>
Date:	Thu, 22 Jan 2009 00:24:46 -0800
From:	"Nicholas A. Bellinger" <nab@...ux-iscsi.org>
To:	"Linux-iSCSI.org Target Dev" 
	<linux-iscsi-target-dev@...glegroups.com>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	linux-scsi <linux-scsi@...r.kernel.org>
Subject: [PATCH 3/4] [Target_Core_Mod] Add generic >= SPC-3 and legacy
	SPC-2 infrastructure

>>From ed2ddd0dac75734bb48c9429ec7d6c75d1d1d93a Mon Sep 17 00:00:00 2001
From: Nicholas Bellinger <nab@...ux-iscsi.org>
Date: Wed, 21 Jan 2009 22:20:20 -0800
Subject: [PATCH 3/4] [Target_Core_Mod] Add generic >= SPC-3 and legacy SPC-2 infrastructure

This patch adds target_core_pr.[c,h] and core_setup_reservations() for an
associated se_device_t / se_subsystem_dev_t and se_cmd_t via $FABRIC_MOD
and Target_Core_Mod/Passthrough ops.

It currently forces Target_Core_Mod/PSCSI to SPC_PASSTHROUGH (no emulation) and
SPC2_RESERVATIONS based on se_subsystem_api_t->get_device_rev() return values
using linux/include/scsi/scsi.h:SCSI_[1,2,3] defines.

The logic for core_scsi3_pr_seq_non_holder() is based on spc4r17 for
controlling access of CDB execution for SCSI Initiator Ports not holding
the SPC-3 compliant reservation.

This code is a WIP for >= SPC-3 Persistent Rervations across
Target_Core_Mod/ConfigFS

Signed-off-by: Nicholas A. Bellinger <nab@...ux-iscsi.org>
---
 drivers/lio-core/Makefile         |    1 +
 drivers/lio-core/target_core_pr.c |  427 +++++++++++++++++++++++++++++++++++++
 drivers/lio-core/target_core_pr.h |   25 +++
 3 files changed, 453 insertions(+), 0 deletions(-)
 create mode 100644 drivers/lio-core/target_core_pr.c
 create mode 100644 drivers/lio-core/target_core_pr.h

diff --git a/drivers/lio-core/Makefile b/drivers/lio-core/Makefile
index 7605add..98a5ef3 100644
--- a/drivers/lio-core/Makefile
+++ b/drivers/lio-core/Makefile
@@ -33,6 +33,7 @@ target_core_mod-objs			:=	target_core_configfs.o \
 						target_core_device.o \
 						target_core_hba.o \
 						target_core_plugin.o \
+						target_core_pr.o \
 						target_core_scdb.o \
 						target_core_seobj.o \
 						target_core_tpg.o \
diff --git a/drivers/lio-core/target_core_pr.c b/drivers/lio-core/target_core_pr.c
new file mode 100644
index 0000000..a81ceaf
--- /dev/null
+++ b/drivers/lio-core/target_core_pr.c
@@ -0,0 +1,427 @@
+/*********************************************************************************
+ * Filename:  target_core_pr.c
+ *
+ * This file contains SPC-3 compliant persistent reservations and
+ * legacy SPC-2 reservations.
+ *
+ * Copyright (c) 2009 Rising Tide, Inc.
+ * Copyright (c) 2009 Linux-iSCSI.org
+ *
+ * Nicholas A. Bellinger <nab@...nel.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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ *********************************************************************************/
+
+#define TARGET_CORE_PR_C
+
+#include <linux/version.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_cmnd.h>
+
+#include <target_core_base.h>
+#include <target_core_device.h>
+#include <target_core_hba.h>
+#include <target_core_transport.h>
+#include <target_core_pr.h>
+#include <target_core_transport_plugin.h>
+#include <target_core_fabric_ops.h>
+#include <target_core_configfs.h>
+
+#undef TARGET_CORE_PR_C
+
+extern int core_scsi2_reservation_seq_non_holder (
+	se_cmd_t *cmd,
+	unsigned char *cdb)
+{
+	switch (cdb[0]) {
+	case INQUIRY:
+	case RELEASE:
+	case RELEASE_10:
+		return(0);
+	default:
+		return(1);
+	}
+
+	return(1);
+}
+
+extern int core_scsi2_reservation_check (se_cmd_t *cmd)
+{
+	se_device_t *dev = cmd->se_dev;
+	se_session_t *sess = cmd->se_sess;
+        int ret;
+
+	if (!(sess))
+		return(0);
+
+        spin_lock(&dev->dev_reservation_lock);
+        if (!dev->dev_reserved_node_acl || !sess) {
+                spin_unlock(&dev->dev_reservation_lock);
+                return(0);
+        }
+        ret = (dev->dev_reserved_node_acl != sess->se_node_acl) ? -1 : 0;
+        spin_unlock(&dev->dev_reservation_lock);
+
+        return(ret);
+}
+
+EXPORT_SYMBOL(core_scsi2_reservation_check);
+
+extern int core_scsi2_reservation_release (se_cmd_t *cmd)
+{
+	se_device_t *dev = cmd->se_dev;
+	se_session_t *sess = cmd->se_sess;
+	se_portal_group_t *tpg = sess->se_tpg;
+
+	if (!(sess) || !(tpg))
+		return(0);
+
+        spin_lock(&dev->dev_reservation_lock);
+        if (!dev->dev_reserved_node_acl || !sess) {
+                spin_unlock(&dev->dev_reservation_lock);
+                return(0);
+        }
+
+        if (dev->dev_reserved_node_acl != sess->se_node_acl) {
+                spin_unlock(&dev->dev_reservation_lock);
+                return(0);
+        }
+        dev->dev_reserved_node_acl = NULL;
+        printk("SCSI-2 Released reservation for %s LUN: %u -> MAPPED LUN:"
+		" %u for %s\n", TPG_TFO(tpg)->get_fabric_name(),
+		SE_LUN(cmd)->unpacked_lun, cmd->se_deve->mapped_lun,
+		sess->se_node_acl->initiatorname);
+        spin_unlock(&dev->dev_reservation_lock);
+
+        return(0);
+}
+
+EXPORT_SYMBOL(core_scsi2_reservation_release);
+
+extern int core_scsi2_reservation_reserve (se_cmd_t *cmd)
+{
+	se_device_t *dev = cmd->se_dev;
+	se_session_t *sess = cmd->se_sess;
+	se_portal_group_t *tpg = sess->se_tpg;
+
+	if ((T_TASK(cmd)->t_task_cdb[1] & 0x01) &&
+	    (T_TASK(cmd)->t_task_cdb[1] & 0x02)) {
+		printk(KERN_ERR "LongIO and Obselete Bits set, returning"
+				" ILLEGAL_REQUEST\n");
+		return(-1);
+	}
+
+	/*
+	 * This is currently the case for target_core_mod passthrough se_cmd_t ops
+	 */
+	if (!(sess) || !(tpg))
+		return(0);
+
+	spin_lock(&dev->dev_reservation_lock);
+	if (dev->dev_reserved_node_acl &&
+	   (dev->dev_reserved_node_acl != sess->se_node_acl)) {
+		printk(KERN_ERR "SCSI-2 RESERVATION CONFLIFT for %s fabric\n",
+			TPG_TFO(tpg)->get_fabric_name());
+		printk(KERN_ERR "Original reserver LUN: %u %s\n",
+			SE_LUN(cmd)->unpacked_lun,
+			dev->dev_reserved_node_acl->initiatorname);
+		printk(KERN_ERR "Current attempt - LUN: %u -> MAPPED LUN: %u"
+			" from %s \n", SE_LUN(cmd)->unpacked_lun,
+			cmd->se_deve->mapped_lun,
+			sess->se_node_acl->initiatorname);
+		spin_unlock(&dev->dev_reservation_lock);
+		return(1);
+        }
+
+	dev->dev_reserved_node_acl = sess->se_node_acl;
+	printk("SCSI-2 Reserved %s LUN: %u -> MAPPED LUN: %u for %s\n",
+		TPG_TFO(tpg)->get_fabric_name(),
+		SE_LUN(cmd)->unpacked_lun, cmd->se_deve->mapped_lun,
+		sess->se_node_acl->initiatorname);
+	spin_unlock(&dev->dev_reservation_lock);
+
+        return(0);
+}
+
+EXPORT_SYMBOL(core_scsi2_reservation_reserve);
+
+/*
+ * Begin SPC-3/SPC-4 Persistent Reservations emulation support
+ */
+static int core_scsi3_pr_seq_non_holder (
+	se_cmd_t *cmd,
+	unsigned char *cdb)
+{
+	int registered_nexus = 0; // FIXME: Table 46
+	int we = 0; // Write Exclusive
+	int legacy = 0; // Act like a legacy device and return RESERVATION CONFLICT on some CDBs
+	/*
+	 * Referenced from spc4r17 table 45 for *NON* PR holder access
+	 */
+	switch (cdb[0]) {
+	case SECURITY_PROTOCOL_IN:
+		return((we) ? 0 : 1);
+	case MODE_SENSE:
+	case MODE_SENSE_10:
+	case READ_ATTRIBUTE:
+	case READ_BUFFER:
+	case RECEIVE_DIAGNOSTIC:
+		if (legacy)
+			return(1);
+		return((we) ? 0 : 1); // Allowed Write Exclusive
+	case PERSISTENT_RESERVE_OUT:
+		/*
+		 * This follows PERSISTENT_RESERVE_OUT service actions that are allows
+		 * in the presence of various reservations.  See spc4r17, table 46
+		 */
+		switch (cdb[1] & 0x1f) {
+		case PRO_CLEAR:
+		case PRO_PREEMPT:
+		case PRO_PREEMPT_AND_ABORT:
+			return((registered_nexus) ? 0 : 1);
+		case PRO_REGISTER:
+		case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
+			return(0);
+		case PRO_REGISTER_AND_MOVE:
+		case PRO_RESERVE:
+			return(1);
+		case PRO_RELEASE:
+			return((registered_nexus) ? 0 : 1);
+		default:
+			printk(KERN_ERR "Unknown PERSISTENT_RESERVE_OUT service"
+				" action: 0x%02x\n", cdb[1] & 0x1f);
+			return(-1);
+		}
+//FIXME PR + legacy RELEASE + RESERVE
+	case RELEASE:
+	case RELEASE_10:
+		return(1); // Conflict
+	case RESERVE:
+	case RESERVE_10:
+		return(1); // Conflict
+	case TEST_UNIT_READY:
+		return((legacy) ? 1 : 0); // Conflict for legacy
+	case MAINTENANCE_IN:
+		switch (cdb[1] & 0x1f) {
+		case MI_MANAGEMENT_PROTOCOL_IN:	
+			return((we) ? 0 : 1); // Allowed Write Exclusive
+		case MI_REPORT_SUPPORTED_OPERATION_CODES:
+		case MI_REPORT_SUPPORTED_TASK_MANAGEMENT_FUNCTIONS:
+			if (legacy)
+				return(1);
+			return((we) ? 0 : 1); // Allowed Write Exclusive
+		case MI_REPORT_ALIASES:
+		case MI_REPORT_IDENTIFYING_INFORMATION:
+		case MI_REPORT_PRIORITY:
+		case MI_REPORT_TARGET_PGS:
+		case MI_REPORT_TIMESTAMP:
+			return(0); // Allowed
+		default:
+			printk(KERN_ERR "Unknown MI Service Action: 0x%02x\n",
+				(cdb[1] & 0x1f));
+			return(-1);
+		}
+	case ACCESS_CONTROL_IN:
+	case ACCESS_CONTROL_OUT:
+	case INQUIRY:
+	case LOG_SENSE:
+	case READ_MEDIA_SERIAL_NUMBER:
+	case REPORT_LUNS:
+	case REQUEST_SENSE:
+		return(0); // Allowed CDBs
+	default:
+		return(1); // Conflift by default
+        }
+
+	return(1);
+}
+
+static int core_scsi3_pr_reservation_check (se_cmd_t *cmd)
+{
+	return(0);
+}
+
+static int core_scsi3_legacy_reserve (se_cmd_t *cmd)
+{
+	return(0);
+}
+
+static int core_scsi3_legacy_release (se_cmd_t *cmd)
+{
+	return(0);
+}
+
+static int core_scsi3_emulate_pro_register (se_cmd_t *cmd)
+{
+	return(0);
+}
+
+static int core_scsi3_emulate_pro_reserve (se_cmd_t *cmd)
+{
+	return(0);
+}
+
+static int core_scsi3_emulate_pro_release (se_cmd_t *cmd)
+{
+	return(0);
+}
+
+static int core_scsi3_emulate_pro_clear (se_cmd_t *cmd)
+{
+	return(0);
+}
+
+static int core_scsi3_emulate_pr_out (se_cmd_t *cmd, unsigned char *cdb)
+{
+	switch (cdb[1] & 0x1f) {
+	case PRO_REGISTER:
+		return(core_scsi3_emulate_pro_register(cmd));
+	case PRO_RESERVE:
+		return(core_scsi3_emulate_pro_reserve(cmd));
+	case PRO_RELEASE:
+		return(core_scsi3_emulate_pro_release(cmd));
+	case PRO_CLEAR:
+		return(core_scsi3_emulate_pro_clear(cmd));
+	case PRO_PREEMPT:
+	case PRO_PREEMPT_AND_ABORT:
+	case PRO_REGISTER_AND_IGNORE_EXISTING_KEY:
+	case PRO_REGISTER_AND_MOVE:
+		printk(KERN_ERR "Unsupported PERSISTENT_RESERVE_OUT service"
+			" action: 0x%02x\n", cdb[1] & 0x1f);
+		return(-1);
+	default:
+		printk(KERN_ERR "Unknown PERSISTENT_RESERVE_OUT service"
+			" action: 0x%02x\n", cdb[1] & 0x1f);
+		return(-1);
+	}
+
+}
+
+static int core_scsi3_pri_read_keys (se_cmd_t *cmd)
+{
+	return(0);
+}
+
+static int core_scsi3_pri_read_reservation (se_cmd_t *cmd)
+{
+	return(0);
+}
+
+static int core_scsi3_pri_report_capabilities (se_cmd_t *cmd)
+{
+	return(0);
+}
+
+static int core_scsi3_pri_read_full_status (se_cmd_t *cmd)
+{
+	return(0);
+}
+
+static int core_scsi3_emulate_pr_in (se_cmd_t *cmd, unsigned char *cdb)
+{
+	switch (cdb[1] & 0x1f) {
+	case PRI_READ_KEYS:
+		return(core_scsi3_pri_read_keys(cmd));
+	case PRI_READ_RESERVATION:
+		return(core_scsi3_pri_read_reservation(cmd));
+	case PRI_REPORT_CAPABILITIES:
+		return(core_scsi3_pri_report_capabilities(cmd));
+	case PRI_READ_FULL_STATUS:
+		return(core_scsi3_pri_read_full_status(cmd));
+	default:
+		printk(KERN_ERR "Unknown PERSISTENT_RESERVE_IN service"
+			" action: 0x%02x\n", cdb[1] & 0x1f);
+		return(-1);
+	}
+
+}
+
+extern int core_scsi3_emulate_pr (se_cmd_t *cmd)
+{
+	unsigned char *cdb = &T_TASK(cmd)->t_task_cdb[0];
+
+	return((cdb[0] == PERSISTENT_RESERVE_OUT) ?
+	       core_scsi3_emulate_pr_out(cmd, cdb) :
+	       core_scsi3_emulate_pr_in(cmd, cdb));
+}
+
+static int core_pt_reservation_check (se_cmd_t *cmd)
+{
+	return(0);
+}
+
+static int core_pt_reserve (se_cmd_t *cmd)
+{
+	return(0);
+}
+
+static int core_pt_release (se_cmd_t *cmd)
+{
+	return(0);
+}
+
+static int core_pt_seq_non_holder (se_cmd_t *cmd, unsigned char *cdb)
+{
+	return(0);
+}
+
+extern int core_setup_reservations (se_device_t *dev)
+{
+	se_subsystem_dev_t *su_dev = dev->se_sub_dev;
+	t10_reservation_template_t *rest = &su_dev->t10_reservation;
+	/*
+	 * If this device is from Target_Core_Mod/pSCSI, use the reservations
+	 * of the Underlying SCSI hardware.  In Linux/SCSI terms, this can
+	 * cause a problem because libata and some SATA RAID HBAs appear
+	 * under Linux/SCSI, but to emulate reservations themselves.
+	 */ 
+	if ((TRANSPORT(dev)->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) &&
+	    !(DEV_ATTRIB(dev)->emulate_reservations)) {
+		rest->res_type = SPC_PASSTHROUGH;
+		rest->t10_reservation_check = &core_pt_reservation_check;
+		rest->t10_reserve = &core_pt_reserve;
+		rest->t10_release = &core_pt_release;
+		rest->t10_seq_non_holder = &core_pt_seq_non_holder;
+		printk("%s: Using SPC_PASSTHROUGH, no reservation emulation\n",
+			TRANSPORT(dev)->name);
+		return(0);
+	}
+	/*
+	 * If SPC-3 or above is reported by real or emulated se_device_t,
+	 * use emulated Persistent Reservations.
+	 */
+	if (TRANSPORT(dev)->get_device_rev(dev) >= SCSI_3) {
+		rest->res_type = SPC3_PERSISTENT_RESERVATIONS;
+		rest->t10_reservation_check = &core_scsi3_pr_reservation_check;
+		rest->t10_reserve = &core_scsi3_legacy_reserve;
+		rest->t10_release = &core_scsi3_legacy_release;
+		rest->t10_seq_non_holder = &core_scsi3_pr_seq_non_holder;
+		printk("%s: Using SPC3_PERSISTENT_RESERVATIONS emulation\n",
+			TRANSPORT(dev)->name);
+	} else {
+		rest->res_type = SPC2_RESERVATIONS;
+		rest->t10_reservation_check = &core_scsi2_reservation_check;
+		rest->t10_reserve = &core_scsi2_reservation_reserve;
+		rest->t10_release = &core_scsi2_reservation_release;
+		rest->t10_seq_non_holder = &core_scsi2_reservation_seq_non_holder;
+		printk("%s: Using SPC2_RESERVATIONS emulation\n",
+			TRANSPORT(dev)->name);
+	}
+
+	return(0);
+}
diff --git a/drivers/lio-core/target_core_pr.h b/drivers/lio-core/target_core_pr.h
new file mode 100644
index 0000000..d32bbdd
--- /dev/null
+++ b/drivers/lio-core/target_core_pr.h
@@ -0,0 +1,25 @@
+/*
+ * PERSISTENT_RESERVE_OUT service action codes
+ *
+ * spc4r17 section 6.14.2 Table 171
+ */
+#define PRO_REGISTER				0x00
+#define PRO_RESERVE				0x01
+#define PRO_RELEASE				0x02
+#define PRO_CLEAR				0x03
+#define PRO_PREEMPT				0x04
+#define PRO_PREEMPT_AND_ABORT			0x05
+#define PRO_REGISTER_AND_IGNORE_EXISTING_KEY	0x06
+#define PRO_REGISTER_AND_MOVE			0x07
+/*
+ * PERSISTENT_RESERVE_IN service action codes
+ *
+ * spc4r17 section 6.13.1 Table 159
+ */
+#define PRI_READ_KEYS				0x00
+#define PRI_READ_RESERVATION			0x01
+#define PRI_REPORT_CAPABILITIES			0x02
+#define PRI_READ_FULL_STATUS			0x03
+
+extern int core_scsi3_emulate_pr (struct se_cmd_s *);
+extern int core_setup_reservations (struct se_device_s *);
-- 
1.5.4.1



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