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>

39 files changed, 22097 insertions, 0 deletions

diff --git a/drivers/target/iscsi/Kconfig b/drivers/target/iscsi/Kconfig
new file mode 100644
index 000000000000..564ff4e0dbc4
--- /dev/null
+++ b/drivers/target/iscsi/Kconfig
@@ -0,0 +1,8 @@
+config ISCSI_TARGET
+	tristate "Linux-iSCSI.org iSCSI Target Mode Stack"
+	select CRYPTO
+	select CRYPTO_CRC32C
+	select CRYPTO_CRC32C_INTEL if X86
+	help
+	Say M here to enable the ConfigFS enabled Linux-iSCSI.org iSCSI
+	Target Mode Stack.
diff --git a/drivers/target/iscsi/Makefile b/drivers/target/iscsi/Makefile
new file mode 100644
index 000000000000..5b9a2cf7f0a9
--- /dev/null
+++ b/drivers/target/iscsi/Makefile
@@ -0,0 +1,20 @@
+iscsi_target_mod-y +=		iscsi_target_parameters.o \
+				iscsi_target_seq_pdu_list.o \
+				iscsi_target_tq.o \
+				iscsi_target_auth.o \
+				iscsi_target_datain_values.o \
+				iscsi_target_device.o \
+				iscsi_target_erl0.o \
+				iscsi_target_erl1.o \
+				iscsi_target_erl2.o \
+				iscsi_target_login.o \
+				iscsi_target_nego.o \
+				iscsi_target_nodeattrib.o \
+				iscsi_target_tmr.o \
+				iscsi_target_tpg.o \
+				iscsi_target_util.o \
+				iscsi_target.o \
+				iscsi_target_configfs.o \
+				iscsi_target_stat.o
+
+obj-$(CONFIG_ISCSI_TARGET)	+= iscsi_target_mod.o
diff --git a/drivers/target/iscsi/iscsi_target.c b/drivers/target/iscsi/iscsi_target.c
new file mode 100644
index 000000000000..14c81c4265bd
--- /dev/null
+++ b/drivers/target/iscsi/iscsi_target.c
@@ -0,0 +1,4559 @@
+/*******************************************************************************
+ * This file contains main functions related to the iSCSI Target Core Driver.
+ *
+ * \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 <linux/string.h>
+#include <linux/kthread.h>
+#include <linux/crypto.h>
+#include <linux/completion.h>
+#include <asm/unaligned.h>
+#include <scsi/scsi_device.h>
+#include <scsi/iscsi_proto.h>
+#include <target/target_core_base.h>
+#include <target/target_core_tmr.h>
+#include <target/target_core_transport.h>
+
+#include "iscsi_target_core.h"
+#include "iscsi_target_parameters.h"
+#include "iscsi_target_seq_pdu_list.h"
+#include "iscsi_target_tq.h"
+#include "iscsi_target_configfs.h"
+#include "iscsi_target_datain_values.h"
+#include "iscsi_target_erl0.h"
+#include "iscsi_target_erl1.h"
+#include "iscsi_target_erl2.h"
+#include "iscsi_target_login.h"
+#include "iscsi_target_tmr.h"
+#include "iscsi_target_tpg.h"
+#include "iscsi_target_util.h"
+#include "iscsi_target.h"
+#include "iscsi_target_device.h"
+#include "iscsi_target_stat.h"
+
+static LIST_HEAD(g_tiqn_list);
+static LIST_HEAD(g_np_list);
+static DEFINE_SPINLOCK(tiqn_lock);
+static DEFINE_SPINLOCK(np_lock);
+
+static struct idr tiqn_idr;
+struct idr sess_idr;
+struct mutex auth_id_lock;
+spinlock_t sess_idr_lock;
+
+struct iscsit_global *iscsit_global;
+
+struct kmem_cache *lio_cmd_cache;
+struct kmem_cache *lio_qr_cache;
+struct kmem_cache *lio_dr_cache;
+struct kmem_cache *lio_ooo_cache;
+struct kmem_cache *lio_r2t_cache;
+
+static int iscsit_handle_immediate_data(struct iscsi_cmd *,
+			unsigned char *buf, u32);
+static int iscsit_logout_post_handler(struct iscsi_cmd *, struct iscsi_conn *);
+
+struct iscsi_tiqn *iscsit_get_tiqn_for_login(unsigned char *buf)
+{
+	struct iscsi_tiqn *tiqn = NULL;
+
+	spin_lock(&tiqn_lock);
+	list_for_each_entry(tiqn, &g_tiqn_list, tiqn_list) {
+		if (!strcmp(tiqn->tiqn, buf)) {
+
+			spin_lock(&tiqn->tiqn_state_lock);
+			if (tiqn->tiqn_state == TIQN_STATE_ACTIVE) {
+				tiqn->tiqn_access_count++;
+				spin_unlock(&tiqn->tiqn_state_lock);
+				spin_unlock(&tiqn_lock);
+				return tiqn;
+			}
+			spin_unlock(&tiqn->tiqn_state_lock);
+		}
+	}
+	spin_unlock(&tiqn_lock);
+
+	return NULL;
+}
+
+static int iscsit_set_tiqn_shutdown(struct iscsi_tiqn *tiqn)
+{
+	spin_lock(&tiqn->tiqn_state_lock);
+	if (tiqn->tiqn_state == TIQN_STATE_ACTIVE) {
+		tiqn->tiqn_state = TIQN_STATE_SHUTDOWN;
+		spin_unlock(&tiqn->tiqn_state_lock);
+		return 0;
+	}
+	spin_unlock(&tiqn->tiqn_state_lock);
+
+	return -1;
+}
+
+void iscsit_put_tiqn_for_login(struct iscsi_tiqn *tiqn)
+{
+	spin_lock(&tiqn->tiqn_state_lock);
+	tiqn->tiqn_access_count--;
+	spin_unlock(&tiqn->tiqn_state_lock);
+}
+
+/*
+ * Note that IQN formatting is expected to be done in userspace, and
+ * no explict IQN format checks are done here.
+ */
+struct iscsi_tiqn *iscsit_add_tiqn(unsigned char *buf)
+{
+	struct iscsi_tiqn *tiqn = NULL;
+	int ret;
+
+	if (strlen(buf) > ISCSI_IQN_LEN) {
+		pr_err("Target IQN exceeds %d bytes\n",
+				ISCSI_IQN_LEN);
+		return ERR_PTR(-EINVAL);
+	}
+
+	tiqn = kzalloc(sizeof(struct iscsi_tiqn), GFP_KERNEL);
+	if (!tiqn) {
+		pr_err("Unable to allocate struct iscsi_tiqn\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	sprintf(tiqn->tiqn, "%s", buf);
+	INIT_LIST_HEAD(&tiqn->tiqn_list);
+	INIT_LIST_HEAD(&tiqn->tiqn_tpg_list);
+	spin_lock_init(&tiqn->tiqn_state_lock);
+	spin_lock_init(&tiqn->tiqn_tpg_lock);
+	spin_lock_init(&tiqn->sess_err_stats.lock);
+	spin_lock_init(&tiqn->login_stats.lock);
+	spin_lock_init(&tiqn->logout_stats.lock);
+
+	if (!idr_pre_get(&tiqn_idr, GFP_KERNEL)) {
+		pr_err("idr_pre_get() for tiqn_idr failed\n");
+		kfree(tiqn);
+		return ERR_PTR(-ENOMEM);
+	}
+	tiqn->tiqn_state = TIQN_STATE_ACTIVE;
+
+	spin_lock(&tiqn_lock);
+	ret = idr_get_new(&tiqn_idr, NULL, &tiqn->tiqn_index);
+	if (ret < 0) {
+		pr_err("idr_get_new() failed for tiqn->tiqn_index\n");
+		spin_unlock(&tiqn_lock);
+		kfree(tiqn);
+		return ERR_PTR(ret);
+	}
+	list_add_tail(&tiqn->tiqn_list, &g_tiqn_list);
+	spin_unlock(&tiqn_lock);
+
+	pr_debug("CORE[0] - Added iSCSI Target IQN: %s\n", tiqn->tiqn);
+
+	return tiqn;
+
+}
+
+static void iscsit_wait_for_tiqn(struct iscsi_tiqn *tiqn)
+{
+	/*
+	 * Wait for accesses to said struct iscsi_tiqn to end.
+	 */
+	spin_lock(&tiqn->tiqn_state_lock);
+	while (tiqn->tiqn_access_count != 0) {
+		spin_unlock(&tiqn->tiqn_state_lock);
+		msleep(10);
+		spin_lock(&tiqn->tiqn_state_lock);
+	}
+	spin_unlock(&tiqn->tiqn_state_lock);
+}
+
+void iscsit_del_tiqn(struct iscsi_tiqn *tiqn)
+{
+	/*
+	 * iscsit_set_tiqn_shutdown sets tiqn->tiqn_state = TIQN_STATE_SHUTDOWN
+	 * while holding tiqn->tiqn_state_lock.  This means that all subsequent
+	 * attempts to access this struct iscsi_tiqn will fail from both transport
+	 * fabric and control code paths.
+	 */
+	if (iscsit_set_tiqn_shutdown(tiqn) < 0) {
+		pr_err("iscsit_set_tiqn_shutdown() failed\n");
+		return;
+	}
+
+	iscsit_wait_for_tiqn(tiqn);
+
+	spin_lock(&tiqn_lock);
+	list_del(&tiqn->tiqn_list);
+	idr_remove(&tiqn_idr, tiqn->tiqn_index);
+	spin_unlock(&tiqn_lock);
+
+	pr_debug("CORE[0] - Deleted iSCSI Target IQN: %s\n",
+			tiqn->tiqn);
+	kfree(tiqn);
+}
+
+int iscsit_access_np(struct iscsi_np *np, struct iscsi_portal_group *tpg)
+{
+	int ret;
+	/*
+	 * Determine if the network portal is accepting storage traffic.
+	 */
+	spin_lock_bh(&np->np_thread_lock);
+	if (np->np_thread_state != ISCSI_NP_THREAD_ACTIVE) {
+		spin_unlock_bh(&np->np_thread_lock);
+		return -1;
+	}
+	if (np->np_login_tpg) {
+		pr_err("np->np_login_tpg() is not NULL!\n");
+		spin_unlock_bh(&np->np_thread_lock);
+		return -1;
+	}
+	spin_unlock_bh(&np->np_thread_lock);
+	/*
+	 * Determine if the portal group is accepting storage traffic.
+	 */
+	spin_lock_bh(&tpg->tpg_state_lock);
+	if (tpg->tpg_state != TPG_STATE_ACTIVE) {
+		spin_unlock_bh(&tpg->tpg_state_lock);
+		return -1;
+	}
+	spin_unlock_bh(&tpg->tpg_state_lock);
+
+	/*
+	 * Here we serialize access across the TIQN+TPG Tuple.
+	 */
+	ret = mutex_lock_interruptible(&tpg->np_login_lock);
+	if ((ret != 0) || signal_pending(current))
+		return -1;
+
+	spin_lock_bh(&np->np_thread_lock);
+	np->np_login_tpg = tpg;
+	spin_unlock_bh(&np->np_thread_lock);
+
+	return 0;
+}
+
+int iscsit_deaccess_np(struct iscsi_np *np, struct iscsi_portal_group *tpg)
+{
+	struct iscsi_tiqn *tiqn = tpg->tpg_tiqn;
+
+	spin_lock_bh(&np->np_thread_lock);
+	np->np_login_tpg = NULL;
+	spin_unlock_bh(&np->np_thread_lock);
+
+	mutex_unlock(&tpg->np_login_lock);
+
+	if (tiqn)
+		iscsit_put_tiqn_for_login(tiqn);
+
+	return 0;
+}
+
+static struct iscsi_np *iscsit_get_np(
+	struct __kernel_sockaddr_storage *sockaddr,
+	int network_transport)
+{
+	struct sockaddr_in *sock_in, *sock_in_e;
+	struct sockaddr_in6 *sock_in6, *sock_in6_e;
+	struct iscsi_np *np;
+	int ip_match = 0;
+	u16 port;
+
+	spin_lock_bh(&np_lock);
+	list_for_each_entry(np, &g_np_list, np_list) {
+		spin_lock(&np->np_thread_lock);
+		if (np->np_thread_state != ISCSI_NP_THREAD_ACTIVE) {
+			spin_unlock(&np->np_thread_lock);
+			continue;
+		}
+
+		if (sockaddr->ss_family == AF_INET6) {
+			sock_in6 = (struct sockaddr_in6 *)sockaddr;
+			sock_in6_e = (struct sockaddr_in6 *)&np->np_sockaddr;
+
+			if (!memcmp((void *)&sock_in6->sin6_addr.in6_u,
+				    (void *)&sock_in6_e->sin6_addr.in6_u,
+				    sizeof(struct in6_addr)))
+				ip_match = 1;
+
+			port = ntohs(sock_in6->sin6_port);
+		} else {
+			sock_in = (struct sockaddr_in *)sockaddr;
+			sock_in_e = (struct sockaddr_in *)&np->np_sockaddr;
+
+			if (sock_in->sin_addr.s_addr ==
+			    sock_in_e->sin_addr.s_addr)
+				ip_match = 1;
+
+			port = ntohs(sock_in->sin_port);
+		}
+
+		if ((ip_match == 1) && (np->np_port == port) &&
+		    (np->np_network_transport == network_transport)) {
+			/*
+			 * Increment the np_exports reference count now to
+			 * prevent iscsit_del_np() below from being called
+			 * while iscsi_tpg_add_network_portal() is called.
+			 */
+			np->np_exports++;
+			spin_unlock(&np->np_thread_lock);
+			spin_unlock_bh(&np_lock);
+			return np;
+		}
+		spin_unlock(&np->np_thread_lock);
+	}
+	spin_unlock_bh(&np_lock);
+
+	return NULL;
+}
+
+struct iscsi_np *iscsit_add_np(
+	struct __kernel_sockaddr_storage *sockaddr,
+	char *ip_str,
+	int network_transport)
+{
+	struct sockaddr_in *sock_in;
+	struct sockaddr_in6 *sock_in6;
+	struct iscsi_np *np;
+	int ret;
+	/*
+	 * Locate the existing struct iscsi_np if already active..
+	 */
+	np = iscsit_get_np(sockaddr, network_transport);
+	if (np)
+		return np;
+
+	np = kzalloc(sizeof(struct iscsi_np), GFP_KERNEL);
+	if (!np) {
+		pr_err("Unable to allocate memory for struct iscsi_np\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	np->np_flags |= NPF_IP_NETWORK;
+	if (sockaddr->ss_family == AF_INET6) {
+		sock_in6 = (struct sockaddr_in6 *)sockaddr;
+		snprintf(np->np_ip, IPV6_ADDRESS_SPACE, "%s", ip_str);
+		np->np_port = ntohs(sock_in6->sin6_port);
+	} else {
+		sock_in = (struct sockaddr_in *)sockaddr;
+		sprintf(np->np_ip, "%s", ip_str);
+		np->np_port = ntohs(sock_in->sin_port);
+	}
+
+	np->np_network_transport = network_transport;
+	spin_lock_init(&np->np_thread_lock);
+	init_completion(&np->np_restart_comp);
+	INIT_LIST_HEAD(&np->np_list);
+
+	ret = iscsi_target_setup_login_socket(np, sockaddr);
+	if (ret != 0) {
+		kfree(np);
+		return ERR_PTR(ret);
+	}
+
+	np->np_thread = kthread_run(iscsi_target_login_thread, np, "iscsi_np");
+	if (IS_ERR(np->np_thread)) {
+		pr_err("Unable to create kthread: iscsi_np\n");
+		ret = PTR_ERR(np->np_thread);
+		kfree(np);
+		return ERR_PTR(ret);
+	}
+	/*
+	 * Increment the np_exports reference count now to prevent
+	 * iscsit_del_np() below from being run while a new call to
+	 * iscsi_tpg_add_network_portal() for a matching iscsi_np is
+	 * active.  We don't need to hold np->np_thread_lock at this
+	 * point because iscsi_np has not been added to g_np_list yet.
+	 */
+	np->np_exports = 1;
+
+	spin_lock_bh(&np_lock);
+	list_add_tail(&np->np_list, &g_np_list);
+	spin_unlock_bh(&np_lock);
+
+	pr_debug("CORE[0] - Added Network Portal: %s:%hu on %s\n",
+		np->np_ip, np->np_port, (np->np_network_transport == ISCSI_TCP) ?
+		"TCP" : "SCTP");
+
+	return np;
+}
+
+int iscsit_reset_np_thread(
+	struct iscsi_np *np,
+	struct iscsi_tpg_np *tpg_np,
+	struct iscsi_portal_group *tpg)
+{
+	spin_lock_bh(&np->np_thread_lock);
+	if (tpg && tpg_np) {
+		/*
+		 * The reset operation need only be performed when the
+		 * passed struct iscsi_portal_group has a login in progress
+		 * to one of the network portals.
+		 */
+		if (tpg_np->tpg_np->np_login_tpg != tpg) {
+			spin_unlock_bh(&np->np_thread_lock);
+			return 0;
+		}
+	}
+	if (np->np_thread_state == ISCSI_NP_THREAD_INACTIVE) {
+		spin_unlock_bh(&np->np_thread_lock);
+		return 0;
+	}
+	np->np_thread_state = ISCSI_NP_THREAD_RESET;
+
+	if (np->np_thread) {
+		spin_unlock_bh(&np->np_thread_lock);
+		send_sig(SIGINT, np->np_thread, 1);
+		wait_for_completion(&np->np_restart_comp);
+		spin_lock_bh(&np->np_thread_lock);
+	}
+	spin_unlock_bh(&np->np_thread_lock);
+
+	return 0;
+}
+
+int iscsit_del_np_comm(struct iscsi_np *np)
+{
+	if (!np->np_socket)
+		return 0;
+
+	/*
+	 * Some network transports allocate their own struct sock->file,
+	 * see  if we need to free any additional allocated resources.
+	 */
+	if (np->np_flags & NPF_SCTP_STRUCT_FILE) {
+		kfree(np->np_socket->file);
+		np->np_socket->file = NULL;
+	}
+
+	sock_release(np->np_socket);
+	return 0;
+}
+
+int iscsit_del_np(struct iscsi_np *np)
+{
+	spin_lock_bh(&np->np_thread_lock);
+	np->np_exports--;
+	if (np->np_exports) {
+		spin_unlock_bh(&np->np_thread_lock);
+		return 0;
+	}
+	np->np_thread_state = ISCSI_NP_THREAD_SHUTDOWN;
+	spin_unlock_bh(&np->np_thread_lock);
+
+	if (np->np_thread) {
+		/*
+		 * We need to send the signal to wakeup Linux/Net
+		 * which may be sleeping in sock_accept()..
+		 */
+		send_sig(SIGINT, np->np_thread, 1);
+		kthread_stop(np->np_thread);
+	}
+	iscsit_del_np_comm(np);
+
+	spin_lock_bh(&np_lock);
+	list_del(&np->np_list);
+	spin_unlock_bh(&np_lock);
+
+	pr_debug("CORE[0] - Removed Network Portal: %s:%hu on %s\n",
+		np->np_ip, np->np_port, (np->np_network_transport == ISCSI_TCP) ?
+		"TCP" : "SCTP");
+
+	kfree(np);
+	return 0;
+}
+
+static int __init iscsi_target_init_module(void)
+{
+	int ret = 0;
+
+	pr_debug("iSCSI-Target "ISCSIT_VERSION"\n");
+
+	iscsit_global = kzalloc(sizeof(struct iscsit_global), GFP_KERNEL);
+	if (!iscsit_global) {
+		pr_err("Unable to allocate memory for iscsit_global\n");
+		return -1;
+	}
+	mutex_init(&auth_id_lock);
+	spin_lock_init(&sess_idr_lock);
+	idr_init(&tiqn_idr);
+	idr_init(&sess_idr);
+
+	ret = iscsi_target_register_configfs();
+	if (ret < 0)
+		goto out;
+
+	ret = iscsi_thread_set_init();
+	if (ret < 0)
+		goto configfs_out;
+
+	if (iscsi_allocate_thread_sets(TARGET_THREAD_SET_COUNT) !=
+			TARGET_THREAD_SET_COUNT) {
+		pr_err("iscsi_allocate_thread_sets() returned"
+			" unexpected value!\n");
+		goto ts_out1;
+	}
+
+	lio_cmd_cache = kmem_cache_create("lio_cmd_cache",
+			sizeof(struct iscsi_cmd), __alignof__(struct iscsi_cmd),
+			0, NULL);
+	if (!lio_cmd_cache) {
+		pr_err("Unable to kmem_cache_create() for"
+				" lio_cmd_cache\n");
+		goto ts_out2;
+	}
+
+	lio_qr_cache = kmem_cache_create("lio_qr_cache",
+			sizeof(struct iscsi_queue_req),
+			__alignof__(struct iscsi_queue_req), 0, NULL);
+	if (!lio_qr_cache) {
+		pr_err("nable to kmem_cache_create() for"
+				" lio_qr_cache\n");
+		goto cmd_out;
+	}
+
+	lio_dr_cache = kmem_cache_create("lio_dr_cache",
+			sizeof(struct iscsi_datain_req),
+			__alignof__(struct iscsi_datain_req), 0, NULL);
+	if (!lio_dr_cache) {
+		pr_err("Unable to kmem_cache_create() for"
+				" lio_dr_cache\n");
+		goto qr_out;
+	}
+
+	lio_ooo_cache = kmem_cache_create("lio_ooo_cache",
+			sizeof(struct iscsi_ooo_cmdsn),
+			__alignof__(struct iscsi_ooo_cmdsn), 0, NULL);
+	if (!lio_ooo_cache) {
+		pr_err("Unable to kmem_cache_create() for"
+				" lio_ooo_cache\n");
+		goto dr_out;
+	}
+
+	lio_r2t_cache = kmem_cache_create("lio_r2t_cache",
+			sizeof(struct iscsi_r2t), __alignof__(struct iscsi_r2t),
+			0, NULL);
+	if (!lio_r2t_cache) {
+		pr_err("Unable to kmem_cache_create() for"
+				" lio_r2t_cache\n");
+		goto ooo_out;
+	}
+
+	if (iscsit_load_discovery_tpg() < 0)
+		goto r2t_out;
+
+	return ret;
+r2t_out:
+	kmem_cache_destroy(lio_r2t_cache);
+ooo_out:
+	kmem_cache_destroy(lio_ooo_cache);
+dr_out:
+	kmem_cache_destroy(lio_dr_cache);
+qr_out:
+	kmem_cache_destroy(lio_qr_cache);
+cmd_out:
+	kmem_cache_destroy(lio_cmd_cache);
+ts_out2:
+	iscsi_deallocate_thread_sets();
+ts_out1:
+	iscsi_thread_set_free();
+configfs_out:
+	iscsi_target_deregister_configfs();
+out:
+	kfree(iscsit_global);
+	return -ENOMEM;
+}
+
+static void __exit iscsi_target_cleanup_module(void)
+{
+	iscsi_deallocate_thread_sets();
+	iscsi_thread_set_free();
+	iscsit_release_discovery_tpg();
+	kmem_cache_destroy(lio_cmd_cache);
+	kmem_cache_destroy(lio_qr_cache);
+	kmem_cache_destroy(lio_dr_cache);
+	kmem_cache_destroy(lio_ooo_cache);
+	kmem_cache_destroy(lio_r2t_cache);
+
+	iscsi_target_deregister_configfs();
+
+	kfree(iscsit_global);
+}
+
+int iscsit_add_reject(
+	u8 reason,
+	int fail_conn,
+	unsigned char *buf,
+	struct iscsi_conn *conn)
+{
+	struct iscsi_cmd *cmd;
+	struct iscsi_reject *hdr;
+	int ret;
+
+	cmd = iscsit_allocate_cmd(conn, GFP_KERNEL);
+	if (!cmd)
+		return -1;
+
+	cmd->iscsi_opcode = ISCSI_OP_REJECT;
+	if (fail_conn)
+		cmd->cmd_flags |= ICF_REJECT_FAIL_CONN;
+
+	hdr	= (struct iscsi_reject *) cmd->pdu;
+	hdr->reason = reason;
+
+	cmd->buf_ptr = kzalloc(ISCSI_HDR_LEN, GFP_KERNEL);
+	if (!cmd->buf_ptr) {
+		pr_err("Unable to allocate memory for cmd->buf_ptr\n");
+		iscsit_release_cmd(cmd);
+		return -1;
+	}
+	memcpy(cmd->buf_ptr, buf, ISCSI_HDR_LEN);
+
+	spin_lock_bh(&conn->cmd_lock);
+	list_add_tail(&cmd->i_list, &conn->conn_cmd_list);
+	spin_unlock_bh(&conn->cmd_lock);
+
+	cmd->i_state = ISTATE_SEND_REJECT;
+	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
+
+	ret = wait_for_completion_interruptible(&cmd->reject_comp);
+	if (ret != 0)
+		return -1;
+
+	return (!fail_conn) ? 0 : -1;
+}
+
+int iscsit_add_reject_from_cmd(
+	u8 reason,
+	int fail_conn,
+	int add_to_conn,
+	unsigned char *buf,
+	struct iscsi_cmd *cmd)
+{
+	struct iscsi_conn *conn;
+	struct iscsi_reject *hdr;
+	int ret;
+
+	if (!cmd->conn) {
+		pr_err("cmd->conn is NULL for ITT: 0x%08x\n",
+				cmd->init_task_tag);
+		return -1;
+	}
+	conn = cmd->conn;
+
+	cmd->iscsi_opcode = ISCSI_OP_REJECT;
+	if (fail_conn)
+		cmd->cmd_flags |= ICF_REJECT_FAIL_CONN;
+
+	hdr	= (struct iscsi_reject *) cmd->pdu;
+	hdr->reason = reason;
+
+	cmd->buf_ptr = kzalloc(ISCSI_HDR_LEN, GFP_KERNEL);
+	if (!cmd->buf_ptr) {
+		pr_err("Unable to allocate memory for cmd->buf_ptr\n");
+		iscsit_release_cmd(cmd);
+		return -1;
+	}
+	memcpy(cmd->buf_ptr, buf, ISCSI_HDR_LEN);
+
+	if (add_to_conn) {
+		spin_lock_bh(&conn->cmd_lock);
+		list_add_tail(&cmd->i_list, &conn->conn_cmd_list);
+		spin_unlock_bh(&conn->cmd_lock);
+	}
+
+	cmd->i_state = ISTATE_SEND_REJECT;
+	iscsit_add_cmd_to_response_queue(cmd, conn, cmd->i_state);
+
+	ret = wait_for_completion_interruptible(&cmd->reject_comp);
+	if (ret != 0)
+		return -1;
+
+	return (!fail_conn) ? 0 : -1;
+}
+
+/*
+ * Map some portion of the allocated scatterlist to an iovec, suitable for
+ * kernel sockets to copy data in/out. This handles both pages and slab-allocated
+ * buffers, since we have been tricky and mapped t_mem_sg to the buffer in
+ * either case (see iscsit_alloc_buffs)
+ */
+static int iscsit_map_iovec(
+	struct iscsi_cmd *cmd,
+	struct kvec *iov,
+	u32 data_offset,
+	u32 data_length)
+{
+	u32 i = 0;
+	struct scatterlist *sg;
+	unsigned int page_off;
+
+	/*
+	 * We have a private mapping of the allocated pages in t_mem_sg.
+	 * At this point, we also know each contains a page.
+	 */
+	sg = &cmd->t_mem_sg[data_offset / PAGE_SIZE];
+	page_off = (data_offset % PAGE_SIZE);
+
+	cmd->first_data_sg = sg;
+	cmd->first_data_sg_off = page_off;
+
+	while (data_length) {
+		u32 cur_len = min_t(u32, data_length, sg->length - page_off);
+
+		iov[i].iov_base = kmap(sg_page(sg)) + sg->offset + page_off;
+		iov[i].iov_len = cur_len;
+
+		data_length -= cur_len;
+		page_off = 0;
+		sg = sg_next(sg);
+		i++;
+	}
+
+	cmd->kmapped_nents = i;
+
+	return i;
+}
+
+static void iscsit_unmap_iovec(struct iscsi_cmd *cmd)
+{
+	u32 i;
+	struct scatterlist *sg;
+
+	sg = cmd->first_data_sg;
+
+	for (i = 0; i < cmd->kmapped_nents; i++)
+		kunmap(sg_page(&sg[i]));
+}
+
+static void iscsit_ack_from_expstatsn(struct iscsi_conn *conn, u32 exp_statsn)
+{
+	struct iscsi_cmd *cmd;
+
+	conn->exp_statsn = exp_statsn;
+
+	spin_lock_bh(&conn->cmd_lock);
+	list_for_each_entry(cmd, &conn->conn_cmd_list, i_list) {
+		spin_lock(&cmd->istate_lock);
+		if ((cmd->i_state == ISTATE_SENT_STATUS) &&
+		    (cmd->stat_sn < exp_statsn)) {
+			cmd->i_state = ISTATE_REMOVE;
+			spin_unlock(&cmd->istate_lock);
+			iscsit_add_cmd_to_immediate_queue(cmd, conn,
+						cmd->i_state);
+			continue;
+		}
+		spin_unlock(&cmd->istate_lock);
+	}
+	spin_unlock_bh(&conn->cmd_lock);
+}
+
+static int iscsit_allocate_iovecs(struct iscsi_cmd *cmd)
+{
+	u32 iov_count = (cmd->se_cmd.t_data_nents == 0) ? 1 :
+				cmd->se_cmd.t_data_nents;
+
+	iov_count += TRANSPORT_IOV_DATA_BUFFER;
+
+	cmd->