drivers/target/tcm_fc/tfc_sess.c - kernel/msm-4.19 - Gitiles

 /*
  * Copyright (c) 2010 Cisco Systems, Inc.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
  * version 2, as published by the Free Software Foundation.
  *
  * This program is distributed in the hope 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.,
  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  */

 /* XXX TBD some includes may be extraneous */

 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/version.h>
 #include <generated/utsrelease.h>
 #include <linux/utsname.h>
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/kthread.h>
 #include <linux/types.h>
 #include <linux/string.h>
 #include <linux/configfs.h>
 #include <linux/ctype.h>
 #include <linux/hash.h>
 #include <linux/rcupdate.h>
 #include <linux/rculist.h>
 #include <linux/kref.h>
 #include <asm/unaligned.h>
 #include <scsi/scsi.h>
 #include <scsi/scsi_host.h>
 #include <scsi/scsi_device.h>
 #include <scsi/scsi_cmnd.h>
 #include <scsi/libfc.h>

 #include <target/target_core_base.h>
 #include <target/target_core_transport.h>
 #include <target/target_core_fabric_ops.h>
 #include <target/target_core_device.h>
 #include <target/target_core_tpg.h>
 #include <target/target_core_configfs.h>
 #include <target/target_core_base.h>
 #include <target/configfs_macros.h>

 #include <scsi/libfc.h>
 #include "tcm_fc.h"

 static void ft_sess_delete_all(struct ft_tport *);

 /*
  * Lookup or allocate target local port.
  * Caller holds ft_lport_lock.
  */
 static struct ft_tport *ft_tport_create(struct fc_lport *lport)
 {
 	struct ft_tpg *tpg;
 	struct ft_tport *tport;
 	int i;

 	tport = rcu_dereference(lport->prov[FC_TYPE_FCP]);
 	if (tport && tport->tpg)
 		return tport;

 	tpg = ft_lport_find_tpg(lport);
 	if (!tpg)
 		return NULL;

 	if (tport) {
 		tport->tpg = tpg;
 		return tport;
 	}

 	tport = kzalloc(sizeof(*tport), GFP_KERNEL);
 	if (!tport)
 		return NULL;

 	tport->lport = lport;
 	tport->tpg = tpg;
 	tpg->tport = tport;
 	for (i = 0; i < FT_SESS_HASH_SIZE; i++)
 		INIT_HLIST_HEAD(&tport->hash[i]);

 	rcu_assign_pointer(lport->prov[FC_TYPE_FCP], tport);
 	return tport;
 }

 /*
  * Free tport via RCU.
  */
 static void ft_tport_rcu_free(struct rcu_head *rcu)
 {
 	struct ft_tport *tport = container_of(rcu, struct ft_tport, rcu);

 	kfree(tport);
 }

 /*
  * Delete a target local port.
  * Caller holds ft_lport_lock.
  */
 static void ft_tport_delete(struct ft_tport *tport)
 {
 	struct fc_lport *lport;
 	struct ft_tpg *tpg;

 	ft_sess_delete_all(tport);
 	lport = tport->lport;
 	BUG_ON(tport != lport->prov[FC_TYPE_FCP]);
 	rcu_assign_pointer(lport->prov[FC_TYPE_FCP], NULL);

 	tpg = tport->tpg;
 	if (tpg) {
 		tpg->tport = NULL;
 		tport->tpg = NULL;
 	}
 	call_rcu(&tport->rcu, ft_tport_rcu_free);
 }

 /*
  * Add local port.
  * Called thru fc_lport_iterate().
  */
 void ft_lport_add(struct fc_lport *lport, void *arg)
 {
 	mutex_lock(&ft_lport_lock);
 	ft_tport_create(lport);
 	mutex_unlock(&ft_lport_lock);
 }

 /*
  * Delete local port.
  * Called thru fc_lport_iterate().
  */
 void ft_lport_del(struct fc_lport *lport, void *arg)
 {
 	struct ft_tport *tport;

 	mutex_lock(&ft_lport_lock);
 	tport = lport->prov[FC_TYPE_FCP];
 	if (tport)
 		ft_tport_delete(tport);
 	mutex_unlock(&ft_lport_lock);
 }

 /*
  * Notification of local port change from libfc.
  * Create or delete local port and associated tport.
  */
 int ft_lport_notify(struct notifier_block *nb, unsigned long event, void *arg)
 {
 	struct fc_lport *lport = arg;

 	switch (event) {
 	case FC_LPORT_EV_ADD:
 		ft_lport_add(lport, NULL);
 		break;
 	case FC_LPORT_EV_DEL:
 		ft_lport_del(lport, NULL);
 		break;
 	}
 	return NOTIFY_DONE;
 }

 /*
  * Hash function for FC_IDs.
  */
 static u32 ft_sess_hash(u32 port_id)
 {
 	return hash_32(port_id, FT_SESS_HASH_BITS);
 }

 /*
  * Find session in local port.
  * Sessions and hash lists are RCU-protected.
  * A reference is taken which must be eventually freed.
  */
 static struct ft_sess *ft_sess_get(struct fc_lport *lport, u32 port_id)
 {
 	struct ft_tport *tport;
 	struct hlist_head *head;
 	struct hlist_node *pos;
 	struct ft_sess *sess;

 	rcu_read_lock();
 	tport = rcu_dereference(lport->prov[FC_TYPE_FCP]);
 	if (!tport)
 		goto out;

 	head = &tport->hash[ft_sess_hash(port_id)];
 	hlist_for_each_entry_rcu(sess, pos, head, hash) {
 		if (sess->port_id == port_id) {
 			kref_get(&sess->kref);
 			rcu_read_unlock();
 			FT_SESS_DBG("port_id %x found %p\n", port_id, sess);
 			return sess;
 		}
 	}
 out:
 	rcu_read_unlock();
 	FT_SESS_DBG("port_id %x not found\n", port_id);
 	return NULL;
 }

 /*
  * Allocate session and enter it in the hash for the local port.
  * Caller holds ft_lport_lock.
  */
 static struct ft_sess *ft_sess_create(struct ft_tport *tport, u32 port_id,
 				      struct ft_node_acl *acl)
 {
 	struct ft_sess *sess;
 	struct hlist_head *head;
 	struct hlist_node *pos;

 	head = &tport->hash[ft_sess_hash(port_id)];
 	hlist_for_each_entry_rcu(sess, pos, head, hash)
 		if (sess->port_id == port_id)
 			return sess;

 	sess = kzalloc(sizeof(*sess), GFP_KERNEL);
 	if (!sess)
 		return NULL;

 	sess->se_sess = transport_init_session();
 	if (!sess->se_sess) {
 		kfree(sess);
 		return NULL;
 	}
 	sess->se_sess->se_node_acl = &acl->se_node_acl;
 	sess->tport = tport;
 	sess->port_id = port_id;
 	kref_init(&sess->kref);	/* ref for table entry */
 	hlist_add_head_rcu(&sess->hash, head);
 	tport->sess_count++;

 	FT_SESS_DBG("port_id %x sess %p\n", port_id, sess);

 	transport_register_session(&tport->tpg->se_tpg, &acl->se_node_acl,
 				   sess->se_sess, sess);
 	return sess;
 }

 /*
  * Unhash the session.
  * Caller holds ft_lport_lock.
  */
 static void ft_sess_unhash(struct ft_sess *sess)
 {
 	struct ft_tport *tport = sess->tport;

 	hlist_del_rcu(&sess->hash);
 	BUG_ON(!tport->sess_count);
 	tport->sess_count--;
 	sess->port_id = -1;
 	sess->params = 0;
 }

 /*
  * Delete session from hash.
  * Caller holds ft_lport_lock.
  */
 static struct ft_sess *ft_sess_delete(struct ft_tport *tport, u32 port_id)
 {
 	struct hlist_head *head;
 	struct hlist_node *pos;
 	struct ft_sess *sess;

 	head = &tport->hash[ft_sess_hash(port_id)];
 	hlist_for_each_entry_rcu(sess, pos, head, hash) {
 		if (sess->port_id == port_id) {
 			ft_sess_unhash(sess);
 			return sess;
 		}
 	}
 	return NULL;
 }

 /*
  * Delete all sessions from tport.
  * Caller holds ft_lport_lock.
  */
 static void ft_sess_delete_all(struct ft_tport *tport)
 {
 	struct hlist_head *head;
 	struct hlist_node *pos;
 	struct ft_sess *sess;

 	for (head = tport->hash;
 	     head < &tport->hash[FT_SESS_HASH_SIZE]; head++) {
 		hlist_for_each_entry_rcu(sess, pos, head, hash) {
 			ft_sess_unhash(sess);
 			transport_deregister_session_configfs(sess->se_sess);
 			ft_sess_put(sess);	/* release from table */
 		}
 	}
 }

 /*
  * TCM ops for sessions.
  */

 /*
  * Determine whether session is allowed to be shutdown in the current context.
  * Returns non-zero if the session should be shutdown.
  */
 int ft_sess_shutdown(struct se_session *se_sess)
 {
 	struct ft_sess *sess = se_sess->fabric_sess_ptr;

 	FT_SESS_DBG("port_id %x\n", sess->port_id);
 	return 1;
 }

 /*
  * Remove session and send PRLO.
  * This is called when the ACL is being deleted or queue depth is changing.
  */
 void ft_sess_close(struct se_session *se_sess)
 {
 	struct ft_sess *sess = se_sess->fabric_sess_ptr;
 	struct fc_lport *lport;
 	u32 port_id;

 	mutex_lock(&ft_lport_lock);
 	lport = sess->tport->lport;
 	port_id = sess->port_id;
 	if (port_id == -1) {
 		mutex_lock(&ft_lport_lock);
 		return;
 	}
 	FT_SESS_DBG("port_id %x\n", port_id);
 	ft_sess_unhash(sess);
 	mutex_unlock(&ft_lport_lock);
 	transport_deregister_session_configfs(se_sess);
 	ft_sess_put(sess);
 	/* XXX Send LOGO or PRLO */
 	synchronize_rcu();		/* let transport deregister happen */
 }

 void ft_sess_stop(struct se_session *se_sess, int sess_sleep, int conn_sleep)
 {
 	struct ft_sess *sess = se_sess->fabric_sess_ptr;

 	FT_SESS_DBG("port_id %x\n", sess->port_id);
 }

 int ft_sess_logged_in(struct se_session *se_sess)
 {
 	struct ft_sess *sess = se_sess->fabric_sess_ptr;

 	return sess->port_id != -1;
 }

 u32 ft_sess_get_index(struct se_session *se_sess)
 {
 	struct ft_sess *sess = se_sess->fabric_sess_ptr;

 	return sess->port_id;	/* XXX TBD probably not what is needed */
 }

 u32 ft_sess_get_port_name(struct se_session *se_sess,
 			  unsigned char *buf, u32 len)
 {
 	struct ft_sess *sess = se_sess->fabric_sess_ptr;

 	return ft_format_wwn(buf, len, sess->port_name);
 }

 void ft_sess_set_erl0(struct se_session *se_sess)
 {
 	/* XXX TBD called when out of memory */
 }

 /*
  * libfc ops involving sessions.
  */

 static int ft_prli_locked(struct fc_rport_priv *rdata, u32 spp_len,
 			  const struct fc_els_spp *rspp, struct fc_els_spp *spp)
 {
 	struct ft_tport *tport;
 	struct ft_sess *sess;
 	struct ft_node_acl *acl;
 	u32 fcp_parm;

 	tport = ft_tport_create(rdata->local_port);
 	if (!tport)
 		return 0;	/* not a target for this local port */

 	acl = ft_acl_get(tport->tpg, rdata);
 	if (!acl)
 		return 0;

 	if (!rspp)
 		goto fill;

 	if (rspp->spp_flags & (FC_SPP_OPA_VAL | FC_SPP_RPA_VAL))
 		return FC_SPP_RESP_NO_PA;

 	/*
 	 * If both target and initiator bits are off, the SPP is invalid.
 	 */
 	fcp_parm = ntohl(rspp->spp_params);
 	if (!(fcp_parm & (FCP_SPPF_INIT_FCN | FCP_SPPF_TARG_FCN)))
 		return FC_SPP_RESP_INVL;

 	/*
 	 * Create session (image pair) only if requested by
 	 * EST_IMG_PAIR flag and if the requestor is an initiator.
 	 */
 	if (rspp->spp_flags & FC_SPP_EST_IMG_PAIR) {
 		spp->spp_flags |= FC_SPP_EST_IMG_PAIR;
 		if (!(fcp_parm & FCP_SPPF_INIT_FCN))
 			return FC_SPP_RESP_CONF;
 		sess = ft_sess_create(tport, rdata->ids.port_id, acl);
 		if (!sess)
 			return FC_SPP_RESP_RES;
 		if (!sess->params)
 			rdata->prli_count++;
 		sess->params = fcp_parm;
 		sess->port_name = rdata->ids.port_name;
 		sess->max_frame = rdata->maxframe_size;

 		/* XXX TBD - clearing actions.  unit attn, see 4.10 */
 	}

 	/*
 	 * OR in our service parameters with other provider (initiator), if any.
 	 * TBD XXX - indicate RETRY capability?
 	 */
 fill:
 	fcp_parm = ntohl(spp->spp_params);
 	spp->spp_params = htonl(fcp_parm | FCP_SPPF_TARG_FCN);
 	return FC_SPP_RESP_ACK;
 }

 /**
  * tcm_fcp_prli() - Handle incoming or outgoing PRLI for the FCP target
  * @rdata: remote port private
  * @spp_len: service parameter page length
  * @rspp: received service parameter page (NULL for outgoing PRLI)
  * @spp: response service parameter page
  *
  * Returns spp response code.
  */
 static int ft_prli(struct fc_rport_priv *rdata, u32 spp_len,
 		   const struct fc_els_spp *rspp, struct fc_els_spp *spp)
 {
 	int ret;

 	mutex_lock(&ft_lport_lock);
 	ret = ft_prli_locked(rdata, spp_len, rspp, spp);
 	mutex_unlock(&ft_lport_lock);
 	FT_SESS_DBG("port_id %x flags %x ret %x\n",
 	       rdata->ids.port_id, rspp ? rspp->spp_flags : 0, ret);
 	return ret;
 }

 static void ft_sess_rcu_free(struct rcu_head *rcu)
 {
 	struct ft_sess *sess = container_of(rcu, struct ft_sess, rcu);

 	transport_deregister_session(sess->se_sess);
 	kfree(sess);
 }

 static void ft_sess_free(struct kref *kref)
 {
 	struct ft_sess *sess = container_of(kref, struct ft_sess, kref);

 	call_rcu(&sess->rcu, ft_sess_rcu_free);
 }

 void ft_sess_put(struct ft_sess *sess)
 {
 	int sess_held = atomic_read(&sess->kref.refcount);

 	BUG_ON(!sess_held);
 	kref_put(&sess->kref, ft_sess_free);
 }

 static void ft_prlo(struct fc_rport_priv *rdata)
 {
 	struct ft_sess *sess;
 	struct ft_tport *tport;

 	mutex_lock(&ft_lport_lock);
 	tport = rcu_dereference(rdata->local_port->prov[FC_TYPE_FCP]);
 	if (!tport) {
 		mutex_unlock(&ft_lport_lock);
 		return;
 	}
 	sess = ft_sess_delete(tport, rdata->ids.port_id);
 	if (!sess) {
 		mutex_unlock(&ft_lport_lock);
 		return;
 	}
 	mutex_unlock(&ft_lport_lock);
 	transport_deregister_session_configfs(sess->se_sess);
 	ft_sess_put(sess);		/* release from table */
 	rdata->prli_count--;
 	/* XXX TBD - clearing actions.  unit attn, see 4.10 */
 }

 /*
  * Handle incoming FCP request.
  * Caller has verified that the frame is type FCP.
  */
 static void ft_recv(struct fc_lport *lport, struct fc_frame *fp)
 {
 	struct ft_sess *sess;
 	u32 sid = fc_frame_sid(fp);

 	FT_SESS_DBG("sid %x\n", sid);

 	sess = ft_sess_get(lport, sid);
 	if (!sess) {
 		FT_SESS_DBG("sid %x sess lookup failed\n", sid);
 		/* TBD XXX - if FCP_CMND, send PRLO */
 		fc_frame_free(fp);
 		return;
 	}
 	ft_recv_req(sess, fp);	/* must do ft_sess_put() */
 }

 /*
  * Provider ops for libfc.
  */
 struct fc4_prov ft_prov = {
 	.prli = ft_prli,
 	.prlo = ft_prlo,
 	.recv = ft_recv,
 	.module = THIS_MODULE,
 };
	/*
	* Copyright (c) 2010 Cisco Systems, Inc.
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms and conditions of the GNU General Public License,
	* version 2, as published by the Free Software Foundation.
	*
	* This program is distributed in the hope 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.,
	* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
	*/

	/* XXX TBD some includes may be extraneous */

	#include <linux/module.h>
	#include <linux/moduleparam.h>
	#include <linux/version.h>
	#include <generated/utsrelease.h>
	#include <linux/utsname.h>
	#include <linux/init.h>
	#include <linux/slab.h>
	#include <linux/kthread.h>
	#include <linux/types.h>
	#include <linux/string.h>
	#include <linux/configfs.h>
	#include <linux/ctype.h>
	#include <linux/hash.h>
	#include <linux/rcupdate.h>
	#include <linux/rculist.h>
	#include <linux/kref.h>
	#include <asm/unaligned.h>
	#include <scsi/scsi.h>
	#include <scsi/scsi_host.h>
	#include <scsi/scsi_device.h>
	#include <scsi/scsi_cmnd.h>
	#include <scsi/libfc.h>

	#include <target/target_core_base.h>
	#include <target/target_core_transport.h>
	#include <target/target_core_fabric_ops.h>
	#include <target/target_core_device.h>
	#include <target/target_core_tpg.h>
	#include <target/target_core_configfs.h>
	#include <target/target_core_base.h>
	#include <target/configfs_macros.h>

	#include <scsi/libfc.h>
	#include "tcm_fc.h"

	static void ft_sess_delete_all(struct ft_tport *);

	/*
	* Lookup or allocate target local port.
	* Caller holds ft_lport_lock.
	*/
	static struct ft_tport ft_tport_create(struct fc_lport lport)
	{
	struct ft_tpg *tpg;
	struct ft_tport *tport;
	int i;

	tport = rcu_dereference(lport->prov[FC_TYPE_FCP]);
	if (tport && tport->tpg)
	return tport;

	tpg = ft_lport_find_tpg(lport);
	if (!tpg)
	return NULL;

	if (tport) {
	tport->tpg = tpg;
	return tport;
	}

	tport = kzalloc(sizeof(*tport), GFP_KERNEL);
	if (!tport)
	return NULL;

	tport->lport = lport;
	tport->tpg = tpg;
	tpg->tport = tport;
	for (i = 0; i < FT_SESS_HASH_SIZE; i++)
	INIT_HLIST_HEAD(&tport->hash[i]);

	rcu_assign_pointer(lport->prov[FC_TYPE_FCP], tport);
	return tport;
	}

	/*
	* Free tport via RCU.
	*/
	static void ft_tport_rcu_free(struct rcu_head *rcu)
	{
	struct ft_tport *tport = container_of(rcu, struct ft_tport, rcu);

	kfree(tport);
	}

	/*
	* Delete a target local port.
	* Caller holds ft_lport_lock.
	*/
	static void ft_tport_delete(struct ft_tport *tport)
	{
	struct fc_lport *lport;
	struct ft_tpg *tpg;

	ft_sess_delete_all(tport);
	lport = tport->lport;
	BUG_ON(tport != lport->prov[FC_TYPE_FCP]);
	rcu_assign_pointer(lport->prov[FC_TYPE_FCP], NULL);

	tpg = tport->tpg;
	if (tpg) {
	tpg->tport = NULL;
	tport->tpg = NULL;
	}
	call_rcu(&tport->rcu, ft_tport_rcu_free);
	}

	/*
	* Add local port.
	* Called thru fc_lport_iterate().
	*/
	void ft_lport_add(struct fc_lport lport, void arg)
	{
	mutex_lock(&ft_lport_lock);
	ft_tport_create(lport);
	mutex_unlock(&ft_lport_lock);
	}

	/*
	* Delete local port.
	* Called thru fc_lport_iterate().
	*/
	void ft_lport_del(struct fc_lport lport, void arg)
	{
	struct ft_tport *tport;

	mutex_lock(&ft_lport_lock);
	tport = lport->prov[FC_TYPE_FCP];
	if (tport)
	ft_tport_delete(tport);
	mutex_unlock(&ft_lport_lock);
	}

	/*
	* Notification of local port change from libfc.
	* Create or delete local port and associated tport.
	*/
	int ft_lport_notify(struct notifier_block nb, unsigned long event, void arg)
	{
	struct fc_lport *lport = arg;

	switch (event) {
	case FC_LPORT_EV_ADD:
	ft_lport_add(lport, NULL);
	break;
	case FC_LPORT_EV_DEL:
	ft_lport_del(lport, NULL);
	break;
	}
	return NOTIFY_DONE;
	}

	/*
	* Hash function for FC_IDs.
	*/
	static u32 ft_sess_hash(u32 port_id)
	{
	return hash_32(port_id, FT_SESS_HASH_BITS);
	}

	/*
	* Find session in local port.
	* Sessions and hash lists are RCU-protected.
	* A reference is taken which must be eventually freed.
	*/
	static struct ft_sess ft_sess_get(struct fc_lport lport, u32 port_id)
	{
	struct ft_tport *tport;
	struct hlist_head *head;
	struct hlist_node *pos;
	struct ft_sess *sess;

	rcu_read_lock();
	tport = rcu_dereference(lport->prov[FC_TYPE_FCP]);
	if (!tport)
	goto out;

	head = &tport->hash[ft_sess_hash(port_id)];
	hlist_for_each_entry_rcu(sess, pos, head, hash) {
	if (sess->port_id == port_id) {
	kref_get(&sess->kref);
	rcu_read_unlock();
	FT_SESS_DBG("port_id %x found %p\n", port_id, sess);
	return sess;
	}
	}
	out:
	rcu_read_unlock();
	FT_SESS_DBG("port_id %x not found\n", port_id);
	return NULL;
	}

	/*
	* Allocate session and enter it in the hash for the local port.
	* Caller holds ft_lport_lock.
	*/
	static struct ft_sess ft_sess_create(struct ft_tport tport, u32 port_id,
	struct ft_node_acl *acl)
	{
	struct ft_sess *sess;
	struct hlist_head *head;
	struct hlist_node *pos;

	head = &tport->hash[ft_sess_hash(port_id)];
	hlist_for_each_entry_rcu(sess, pos, head, hash)
	if (sess->port_id == port_id)
	return sess;

	sess = kzalloc(sizeof(*sess), GFP_KERNEL);
	if (!sess)
	return NULL;

	sess->se_sess = transport_init_session();
	if (!sess->se_sess) {
	kfree(sess);
	return NULL;
	}
	sess->se_sess->se_node_acl = &acl->se_node_acl;
	sess->tport = tport;
	sess->port_id = port_id;
	kref_init(&sess->kref); /* ref for table entry */
	hlist_add_head_rcu(&sess->hash, head);
	tport->sess_count++;

	FT_SESS_DBG("port_id %x sess %p\n", port_id, sess);

	transport_register_session(&tport->tpg->se_tpg, &acl->se_node_acl,
	sess->se_sess, sess);
	return sess;
	}

	/*
	* Unhash the session.
	* Caller holds ft_lport_lock.
	*/
	static void ft_sess_unhash(struct ft_sess *sess)
	{
	struct ft_tport *tport = sess->tport;

	hlist_del_rcu(&sess->hash);
	BUG_ON(!tport->sess_count);
	tport->sess_count--;
	sess->port_id = -1;
	sess->params = 0;
	}

	/*
	* Delete session from hash.
	* Caller holds ft_lport_lock.
	*/
	static struct ft_sess ft_sess_delete(struct ft_tport tport, u32 port_id)
	{
	struct hlist_head *head;
	struct hlist_node *pos;
	struct ft_sess *sess;

	head = &tport->hash[ft_sess_hash(port_id)];
	hlist_for_each_entry_rcu(sess, pos, head, hash) {
	if (sess->port_id == port_id) {
	ft_sess_unhash(sess);
	return sess;
	}
	}
	return NULL;
	}

	/*
	* Delete all sessions from tport.
	* Caller holds ft_lport_lock.
	*/
	static void ft_sess_delete_all(struct ft_tport *tport)
	{
	struct hlist_head *head;
	struct hlist_node *pos;
	struct ft_sess *sess;

	for (head = tport->hash;
	head < &tport->hash[FT_SESS_HASH_SIZE]; head++) {
	hlist_for_each_entry_rcu(sess, pos, head, hash) {
	ft_sess_unhash(sess);
	transport_deregister_session_configfs(sess->se_sess);
	ft_sess_put(sess); /* release from table */
	}
	}
	}

	/*
	* TCM ops for sessions.
	*/

	/*
	* Determine whether session is allowed to be shutdown in the current context.
	* Returns non-zero if the session should be shutdown.
	*/
	int ft_sess_shutdown(struct se_session *se_sess)
	{
	struct ft_sess *sess = se_sess->fabric_sess_ptr;

	FT_SESS_DBG("port_id %x\n", sess->port_id);
	return 1;
	}

	/*
	* Remove session and send PRLO.
	* This is called when the ACL is being deleted or queue depth is changing.
	*/
	void ft_sess_close(struct se_session *se_sess)
	{
	struct ft_sess *sess = se_sess->fabric_sess_ptr;
	struct fc_lport *lport;
	u32 port_id;

	mutex_lock(&ft_lport_lock);
	lport = sess->tport->lport;
	port_id = sess->port_id;
	if (port_id == -1) {
	mutex_lock(&ft_lport_lock);
	return;
	}
	FT_SESS_DBG("port_id %x\n", port_id);
	ft_sess_unhash(sess);
	mutex_unlock(&ft_lport_lock);
	transport_deregister_session_configfs(se_sess);
	ft_sess_put(sess);
	/* XXX Send LOGO or PRLO */
	synchronize_rcu(); /* let transport deregister happen */
	}

	void ft_sess_stop(struct se_session *se_sess, int sess_sleep, int conn_sleep)
	{
	struct ft_sess *sess = se_sess->fabric_sess_ptr;

	FT_SESS_DBG("port_id %x\n", sess->port_id);
	}

	int ft_sess_logged_in(struct se_session *se_sess)
	{
	struct ft_sess *sess = se_sess->fabric_sess_ptr;

	return sess->port_id != -1;
	}

	u32 ft_sess_get_index(struct se_session *se_sess)
	{
	struct ft_sess *sess = se_sess->fabric_sess_ptr;

	return sess->port_id; /* XXX TBD probably not what is needed */
	}

	u32 ft_sess_get_port_name(struct se_session *se_sess,
	unsigned char *buf, u32 len)
	{
	struct ft_sess *sess = se_sess->fabric_sess_ptr;

	return ft_format_wwn(buf, len, sess->port_name);
	}

	void ft_sess_set_erl0(struct se_session *se_sess)
	{
	/* XXX TBD called when out of memory */
	}

	/*
	* libfc ops involving sessions.
	*/

	static int ft_prli_locked(struct fc_rport_priv *rdata, u32 spp_len,
	const struct fc_els_spp rspp, struct fc_els_spp spp)
	{
	struct ft_tport *tport;
	struct ft_sess *sess;
	struct ft_node_acl *acl;
	u32 fcp_parm;

	tport = ft_tport_create(rdata->local_port);
	if (!tport)
	return 0; /* not a target for this local port */

	acl = ft_acl_get(tport->tpg, rdata);
	if (!acl)
	return 0;

	if (!rspp)
	goto fill;

	if (rspp->spp_flags & (FC_SPP_OPA_VAL \| FC_SPP_RPA_VAL))
	return FC_SPP_RESP_NO_PA;

	/*
	* If both target and initiator bits are off, the SPP is invalid.
	*/
	fcp_parm = ntohl(rspp->spp_params);
	if (!(fcp_parm & (FCP_SPPF_INIT_FCN \| FCP_SPPF_TARG_FCN)))
	return FC_SPP_RESP_INVL;

	/*
	* Create session (image pair) only if requested by
	* EST_IMG_PAIR flag and if the requestor is an initiator.
	*/
	if (rspp->spp_flags & FC_SPP_EST_IMG_PAIR) {
	spp->spp_flags \|= FC_SPP_EST_IMG_PAIR;
	if (!(fcp_parm & FCP_SPPF_INIT_FCN))
	return FC_SPP_RESP_CONF;
	sess = ft_sess_create(tport, rdata->ids.port_id, acl);
	if (!sess)
	return FC_SPP_RESP_RES;
	if (!sess->params)
	rdata->prli_count++;
	sess->params = fcp_parm;
	sess->port_name = rdata->ids.port_name;
	sess->max_frame = rdata->maxframe_size;

	/* XXX TBD - clearing actions. unit attn, see 4.10 */
	}

	/*
	* OR in our service parameters with other provider (initiator), if any.
	* TBD XXX - indicate RETRY capability?
	*/
	fill:
	fcp_parm = ntohl(spp->spp_params);
	spp->spp_params = htonl(fcp_parm \| FCP_SPPF_TARG_FCN);
	return FC_SPP_RESP_ACK;
	}

	/**
	* tcm_fcp_prli() - Handle incoming or outgoing PRLI for the FCP target
	* @rdata: remote port private
	* @spp_len: service parameter page length
	* @rspp: received service parameter page (NULL for outgoing PRLI)
	* @spp: response service parameter page
	*
	* Returns spp response code.
	*/
	static int ft_prli(struct fc_rport_priv *rdata, u32 spp_len,
	const struct fc_els_spp rspp, struct fc_els_spp spp)
	{
	int ret;

	mutex_lock(&ft_lport_lock);
	ret = ft_prli_locked(rdata, spp_len, rspp, spp);
	mutex_unlock(&ft_lport_lock);
	FT_SESS_DBG("port_id %x flags %x ret %x\n",
	rdata->ids.port_id, rspp ? rspp->spp_flags : 0, ret);
	return ret;
	}

	static void ft_sess_rcu_free(struct rcu_head *rcu)
	{
	struct ft_sess *sess = container_of(rcu, struct ft_sess, rcu);

	transport_deregister_session(sess->se_sess);
	kfree(sess);
	}

	static void ft_sess_free(struct kref *kref)
	{
	struct ft_sess *sess = container_of(kref, struct ft_sess, kref);

	call_rcu(&sess->rcu, ft_sess_rcu_free);
	}

	void ft_sess_put(struct ft_sess *sess)
	{
	int sess_held = atomic_read(&sess->kref.refcount);

	BUG_ON(!sess_held);
	kref_put(&sess->kref, ft_sess_free);
	}

	static void ft_prlo(struct fc_rport_priv *rdata)
	{
	struct ft_sess *sess;
	struct ft_tport *tport;

	mutex_lock(&ft_lport_lock);
	tport = rcu_dereference(rdata->local_port->prov[FC_TYPE_FCP]);
	if (!tport) {
	mutex_unlock(&ft_lport_lock);
	return;
	}
	sess = ft_sess_delete(tport, rdata->ids.port_id);
	if (!sess) {
	mutex_unlock(&ft_lport_lock);
	return;
	}
	mutex_unlock(&ft_lport_lock);
	transport_deregister_session_configfs(sess->se_sess);
	ft_sess_put(sess); /* release from table */
	rdata->prli_count--;
	/* XXX TBD - clearing actions. unit attn, see 4.10 */
	}

	/*
	* Handle incoming FCP request.
	* Caller has verified that the frame is type FCP.
	*/
	static void ft_recv(struct fc_lport lport, struct fc_frame fp)
	{
	struct ft_sess *sess;
	u32 sid = fc_frame_sid(fp);

	FT_SESS_DBG("sid %x\n", sid);

	sess = ft_sess_get(lport, sid);
	if (!sess) {
	FT_SESS_DBG("sid %x sess lookup failed\n", sid);
	/* TBD XXX - if FCP_CMND, send PRLO */
	fc_frame_free(fp);
	return;
	}
	ft_recv_req(sess, fp); /* must do ft_sess_put() */
	}

	/*
	* Provider ops for libfc.
	*/
	struct fc4_prov ft_prov = {
	.prli = ft_prli,
	.prlo = ft_prlo,
	.recv = ft_recv,
	.module = THIS_MODULE,
	};