text: /*
   * 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 <asm/unaligned.h>
  #include <scsi/scsi.h>
  #include <scsi/scsi_host.h>
  #include <scsi/scsi_device.h>
  #include <scsi/scsi_cmnd.h>
  #include <scsi/scsi_tcq.h>
  #include <scsi/libfc.h>
  #include <scsi/fc_encode.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/target_core_tmr.h>
  #include <target/configfs_macros.h>
  
  #include "tcm_fc.h"
  
  /*
   * Dump cmd state for debugging.
   */
  void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
  {
  	struct fc_exch *ep;
  	struct fc_seq *sp;
  	struct se_cmd *se_cmd;
  	struct se_mem *mem;
  	struct se_transport_task *task;
  
  	if (!(ft_debug_logging & FT_DEBUG_IO))
  		return;
  
  	se_cmd = &cmd->se_cmd;
  	printk(KERN_INFO "%s: cmd %p state %d sess %p seq %p se_cmd %p\n",
  		caller, cmd, cmd->state, cmd->sess, cmd->seq, se_cmd);
  	printk(KERN_INFO "%s: cmd %p cdb %p\n",
  		caller, cmd, cmd->cdb);
  	printk(KERN_INFO "%s: cmd %p lun %d\n", caller, cmd, cmd->lun);
  
  	task = T_TASK(se_cmd);
  	printk(KERN_INFO "%s: cmd %p task %p se_num %u buf %p len %u se_cmd_flags <0x%x>\n",
  	       caller, cmd, task, task->t_tasks_se_num,
  	       task->t_task_buf, se_cmd->data_length, se_cmd->se_cmd_flags);
  	if (task->t_mem_list)
  		list_for_each_entry(mem, task->t_mem_list, se_list)
  			printk(KERN_INFO "%s: cmd %p mem %p page %p "
  			       "len 0x%x off 0x%x\n",
  			       caller, cmd, mem,
  			       mem->se_page, mem->se_len, mem->se_off);
  	sp = cmd->seq;
  	if (sp) {
  		ep = fc_seq_exch(sp);
  		printk(KERN_INFO "%s: cmd %p sid %x did %x "
  			"ox_id %x rx_id %x seq_id %x e_stat %x\n",
  			caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
  			sp->id, ep->esb_stat);
  	}
  	print_hex_dump(KERN_INFO, "ft_dump_cmd ", DUMP_PREFIX_NONE,
  		16, 4, cmd->cdb, MAX_COMMAND_SIZE, 0);
  }
  
  static void ft_queue_cmd(struct ft_sess *sess, struct ft_cmd *cmd)
  {
  	struct se_queue_obj *qobj;
  	unsigned long flags;
  
  	qobj = &sess->tport->tpg->qobj;
  	spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
  	list_add_tail(&cmd->se_req.qr_list, &qobj->qobj_list);
  	spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
  	atomic_inc(&qobj->queue_cnt);
  	wake_up_interruptible(&qobj->thread_wq);
  }
  
  static struct ft_cmd *ft_dequeue_cmd(struct se_queue_obj *qobj)
  {
  	unsigned long flags;
  	struct se_queue_req *qr;
  
  	spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
  	if (list_empty(&qobj->qobj_list)) {
  		spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
  		return NULL;
  	}
  	qr = list_first_entry(&qobj->qobj_list, struct se_queue_req, qr_list);
  	list_del(&qr->qr_list);
  	atomic_dec(&qobj->queue_cnt);
  	spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
  	return container_of(qr, struct ft_cmd, se_req);
  }
  
  static void ft_free_cmd(struct ft_cmd *cmd)
  {
  	struct fc_frame *fp;
  	struct fc_lport *lport;
  
  	if (!cmd)
  		return;
  	fp = cmd->req_frame;
  	lport = fr_dev(fp);
  	if (fr_seq(fp))
  		lport->tt.seq_release(fr_seq(fp));
  	fc_frame_free(fp);
  	ft_sess_put(cmd->sess);	/* undo get from lookup at recv */
  	kfree(cmd);
  }
  
  void ft_release_cmd(struct se_cmd *se_cmd)
  {
  	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
  
  	ft_free_cmd(cmd);
  }
  
  void ft_check_stop_free(struct se_cmd *se_cmd)
  {
  	transport_generic_free_cmd(se_cmd, 0, 1, 0);
  }
  
  /*
   * Send response.
   */
  int ft_queue_status(struct se_cmd *se_cmd)
  {
  	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
  	struct fc_frame *fp;
  	struct fcp_resp_with_ext *fcp;
  	struct fc_lport *lport;
  	struct fc_exch *ep;
  	size_t len;
  
  	ft_dump_cmd(cmd, __func__);
  	ep = fc_seq_exch(cmd->seq);
  	lport = ep->lp;
  	len = sizeof(*fcp) + se_cmd->scsi_sense_length;
  	fp = fc_frame_alloc(lport, len);
  	if (!fp) {
  		/* XXX shouldn't just drop it - requeue and retry? */
  		return 0;
  	}
  	fcp = fc_frame_payload_get(fp, len);
  	memset(fcp, 0, len);
  	fcp->resp.fr_status = se_cmd->scsi_status;
  
  	len = se_cmd->scsi_sense_length;
  	if (len) {
  		fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
  		fcp->ext.fr_sns_len = htonl(len);
  		memcpy((fcp + 1), se_cmd->sense_buffer, len);
  	}
  
  	/*
  	 * Test underflow and overflow with one mask.  Usually both are off.
  	 * Bidirectional commands are not handled yet.
  	 */
  	if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
  		if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
  			fcp->resp.fr_flags |= FCP_RESID_OVER;
  		else
  			fcp->resp.fr_flags |= FCP_RESID_UNDER;
  		fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
  	}
  
  	/*
  	 * Send response.
  	 */
  	cmd->seq = lport->tt.seq_start_next(cmd->seq);
  	fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
  		       FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
  
  	lport->tt.seq_send(lport, cmd->seq, fp);
  	lport->tt.exch_done(cmd->seq);
  	return 0;
  }
  
  int ft_write_pending_status(struct se_cmd *se_cmd)
  {
  	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
  
  	return cmd->write_data_len != se_cmd->data_length;
  }
  
  /*
   * Send TX_RDY (transfer ready).
   */
  int ft_write_pending(struct se_cmd *se_cmd)
  {
  	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
  	struct fc_frame *fp;
  	struct fcp_txrdy *txrdy;
  	struct fc_lport *lport;
  	struct fc_exch *ep;
  	struct fc_frame_header *fh;
  	u32 f_ctl;
  
  	ft_dump_cmd(cmd, __func__);
  
  	ep = fc_seq_exch(cmd->seq);
  	lport = ep->lp;
  	fp = fc_frame_alloc(lport, sizeof(*txrdy));
  	if (!fp)
  		return PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
  
  	txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
  	memset(txrdy, 0, sizeof(*txrdy));
  	txrdy->ft_burst_len = htonl(se_cmd->data_length);
  
  	cmd->seq = lport->tt.seq_start_next(cmd->seq);
  	fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
  		       FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
  
  	fh = fc_frame_header_get(fp);
  	f_ctl = ntoh24(fh->fh_f_ctl);
  
  	/* Only if it is 'Exchange Responder' */
  	if (f_ctl & FC_FC_EX_CTX) {
  		/* Target is 'exchange responder' and sending XFER_READY
  		 * to 'exchange initiator (initiator)'
  		 */
  		if ((ep->xid <= lport->lro_xid) &&
  		    (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
  			if (se_cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) {
  				/*
  				 * Map se_mem list to scatterlist, so that
  				 * DDP can be setup. DDP setup function require
  				 * scatterlist. se_mem_list is internal to
  				 * TCM/LIO target
  				 */
  				transport_do_task_sg_chain(se_cmd);
  				cmd->sg = T_TASK(se_cmd)->t_tasks_sg_chained;
  				cmd->sg_cnt =
  					T_TASK(se_cmd)->t_tasks_sg_chained_no;
  			}
  			if (cmd->sg && lport->tt.ddp_setup(lport, ep->xid,
  						    cmd->sg, cmd->sg_cnt))
  				cmd->was_ddp_setup = 1;
  		}
  	}
  	lport->tt.seq_send(lport, cmd->seq, fp);
  	return 0;
  }
  
  u32 ft_get_task_tag(struct se_cmd *se_cmd)
  {
  	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
  
  	return fc_seq_exch(cmd->seq)->rxid;
  }
  
  int ft_get_cmd_state(struct se_cmd *se_cmd)
  {
  	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
  
  	return cmd->state;
  }
  
  int ft_is_state_remove(struct se_cmd *se_cmd)
  {
  	return 0;	/* XXX TBD */
  }
  
  void ft_new_cmd_failure(struct se_cmd *se_cmd)
  {
  	/* XXX TBD */
  	printk(KERN_INFO "%s: se_cmd %p\n", __func__, se_cmd);
  }
  
  /*
   * FC sequence response handler for follow-on sequences (data) and aborts.
   */
  static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
  {
  	struct ft_cmd *cmd = arg;
  	struct fc_frame_header *fh;
  
  	if (IS_ERR(fp)) {
  		/* XXX need to find cmd if queued */
  		cmd->se_cmd.t_state = TRANSPORT_REMOVE;
  		cmd->seq = NULL;
  		transport_generic_free_cmd(&cmd->se_cmd, 0, 1, 0);
  		return;
  	}
  
  	fh = fc_frame_header_get(fp);
  
  	switch (fh->fh_r_ctl) {
  	case FC_RCTL_DD_SOL_DATA:	/* write data */
  		ft_recv_write_data(cmd, fp);
  		break;
  	case FC_RCTL_DD_UNSOL_CTL:	/* command */
  	case FC_RCTL_DD_SOL_CTL:	/* transfer ready */
  	case FC_RCTL_DD_DATA_DESC:	/* transfer ready */
  	default:
  		printk(KERN_INFO "%s: unhandled frame r_ctl %x\n",
  		       __func__, fh->fh_r_ctl);
  		fc_frame_free(fp);
  		transport_generic_free_cmd(&cmd->se_cmd, 0, 1, 0);
  		break;
  	}
  }
  
  /*
   * Send a FCP response including SCSI status and optional FCP rsp_code.
   * status is SAM_STAT_GOOD (zero) iff code is valid.
   * This is used in error cases, such as allocation failures.
   */
  static void ft_send_resp_status(struct fc_lport *lport,
  				const struct fc_frame *rx_fp,
  				u32 status, enum fcp_resp_rsp_codes code)
  {
  	struct fc_frame *fp;
  	struct fc_seq *sp;
  	const struct fc_frame_header *fh;
  	size_t len;
  	struct fcp_resp_with_ext *fcp;
  	struct fcp_resp_rsp_info *info;
  
  	fh = fc_frame_header_get(rx_fp);
  	FT_IO_DBG("FCP error response: did %x oxid %x status %x code %x\n",
  		  ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
  	len = sizeof(*fcp);
  	if (status == SAM_STAT_GOOD)
  		len += sizeof(*info);
  	fp = fc_frame_alloc(lport, len);
  	if (!fp)
  		return;
  	fcp = fc_frame_payload_get(fp, len);
  	memset(fcp, 0, len);
  	fcp->resp.fr_status = status;
  	if (status == SAM_STAT_GOOD) {
  		fcp->ext.fr_rsp_len = htonl(sizeof(*info));
  		fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
  		info = (struct fcp_resp_rsp_info *)(fcp + 1);
  		info->rsp_code = code;
  	}
  
  	fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
  	sp = fr_seq(fp);
  	if (sp) {
  		lport->tt.seq_send(lport, sp, fp);
  		lport->tt.exch_done(sp);
  	} else {
  		lport->tt.frame_send(lport, fp);
  	}
  }
  
  /*
   * Send error or task management response.
   * Always frees the cmd and associated state.
   */
  static void ft_send_resp_code(struct ft_cmd *cmd, enum fcp_resp_rsp_codes code)
  {
  	ft_send_resp_status(cmd->sess->tport->lport,
  			    cmd->req_frame, SAM_STAT_GOOD, code);
  	ft_free_cmd(cmd);
  }
  
  /*
   * Handle Task Management Request.
   */
  static void ft_send_tm(struct ft_cmd *cmd)
  {
  	struct se_tmr_req *tmr;
  	struct fcp_cmnd *fcp;
  	struct ft_sess *sess;
  	u8 tm_func;
  
  	fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
  
  	switch (fcp->fc_tm_flags) {
  	case FCP_TMF_LUN_RESET:
  		tm_func = TMR_LUN_RESET;
  		break;
  	case FCP_TMF_TGT_RESET:
  		tm_func = TMR_TARGET_WARM_RESET;
  		break;
  	case FCP_TMF_CLR_TASK_SET:
  		tm_func = TMR_CLEAR_TASK_SET;
  		break;
  	case FCP_TMF_ABT_TASK_SET:
  		tm_func = TMR_ABORT_TASK_SET;
  		break;
  	case FCP_TMF_CLR_ACA:
  		tm_func = TMR_CLEAR_ACA;
  		break;
  	default:
  		/*
  		 * FCP4r01 indicates having a combination of
  		 * tm_flags set is invalid.
  		 */
  		FT_TM_DBG("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
  		ft_send_resp_code(cmd, FCP_CMND_FIELDS_INVALID);
  		return;
  	}
  
  	FT_TM_DBG("alloc tm cmd fn %d\n", tm_func);
  	tmr = core_tmr_alloc_req(&cmd->se_cmd, cmd, tm_func);
  	if (!tmr) {
  		FT_TM_DBG("alloc failed\n");
  		ft_send_resp_code(cmd, FCP_TMF_FAILED);
  		return;
  	}
  	cmd->se_cmd.se_tmr_req = tmr;
  
  	switch (fcp->fc_tm_flags) {
  	case FCP_TMF_LUN_RESET:
  		cmd->lun = scsilun_to_int((struct scsi_lun *)fcp->fc_lun);
  		if (transport_get_lun_for_tmr(&cmd->se_cmd, cmd->lun) < 0) {
  			/*
  			 * Make sure to clean up newly allocated TMR request
  			 * since "unable to  handle TMR request because failed
  			 * to get to LUN"
  			 */
  			FT_TM_DBG("Failed to get LUN for TMR func %d, "
  				  "se_cmd %p, unpacked_lun %d\n",
  				  tm_func, &cmd->se_cmd, cmd->lun);
  			ft_dump_cmd(cmd, __func__);
  			sess = cmd->sess;
  			transport_send_check_condition_and_sense(&cmd->se_cmd,
  				cmd->se_cmd.scsi_sense_reason, 0);
  			transport_generic_free_cmd(&cmd->se_cmd, 0, 1, 0);
  			ft_sess_put(sess);
  			return;
  		}
  		break;
  	case FCP_TMF_TGT_RESET:
  	case FCP_TMF_CLR_TASK_SET:
  	case FCP_TMF_ABT_TASK_SET:
  	case FCP_TMF_CLR_ACA:
  		break;
  	default:
  		return;
  	}
  	transport_generic_handle_tmr(&cmd->se_cmd);
  }
  
  /*
   * Send status from completed task management request.
   */
  int ft_queue_tm_resp(struct se_cmd *se_cmd)
  {
  	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
  	struct se_tmr_req *tmr = se_cmd->se_tmr_req;
  	enum fcp_resp_rsp_codes code;
  
  	switch (tmr->response) {
  	case TMR_FUNCTION_COMPLETE:
  		code = FCP_TMF_CMPL;
  		break;
  	case TMR_LUN_DOES_NOT_EXIST:
  		code = FCP_TMF_INVALID_LUN;
  		break;
  	case TMR_FUNCTION_REJECTED:
  		code = FCP_TMF_REJECTED;
  		break;
  	case TMR_TASK_DOES_NOT_EXIST:
  	case TMR_TASK_STILL_ALLEGIANT:
  	case TMR_TASK_FAILOVER_NOT_SUPPORTED:
  	case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
  	case TMR_FUNCTION_AUTHORIZATION_FAILED:
  	default:
  		code = FCP_TMF_FAILED;
  		break;
  	}
  	FT_TM_DBG("tmr fn %d resp %d fcp code %d\n",
  		  tmr->function, tmr->response, code);
  	ft_send_resp_code(cmd, code);
  	return 0;
  }
  
  /*
   * Handle incoming FCP command.
   */
  static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
  {
  	struct ft_cmd *cmd;
  	struct fc_lport *lport = sess->tport->lport;
  
  	cmd = kzalloc(sizeof(*cmd), GFP_ATOMIC);
  	if (!cmd)
  		goto busy;
  	cmd->sess = sess;
  	cmd->seq = lport->tt.seq_assign(lport, fp);
  	if (!cmd->seq) {
  		kfree(cmd);
  		goto busy;
  	}
  	cmd->req_frame = fp;		/* hold frame during cmd */
  	ft_queue_cmd(sess, cmd);
  	return;
  
  busy:
  	FT_IO_DBG("cmd or seq allocation failure - sending BUSY\n");
  	ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
  	fc_frame_free(fp);
  	ft_sess_put(sess);		/* undo get from lookup */
  }
  
  /*
   * Handle incoming FCP frame.
   * Caller has verified that the frame is type FCP.
   */
  void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
  {
  	struct fc_frame_header *fh = fc_frame_header_get(fp);
  
  	switch (fh->fh_r_ctl) {
  	case FC_RCTL_DD_UNSOL_CMD:	/* command */
  		ft_recv_cmd(sess, fp);
  		break;
  	case FC_RCTL_DD_SOL_DATA:	/* write data */
  	case FC_RCTL_DD_UNSOL_CTL:
  	case FC_RCTL_DD_SOL_CTL:
  	case FC_RCTL_DD_DATA_DESC:	/* transfer ready */
  	case FC_RCTL_ELS4_REQ:		/* SRR, perhaps */
  	default:
  		printk(KERN_INFO "%s: unhandled frame r_ctl %x\n",
  		       __func__, fh->fh_r_ctl);
  		fc_frame_free(fp);
  		ft_sess_put(sess);	/* undo get from lookup */
  		break;
  	}
  }
  
  /*
   * Send new command to target.
   */
  static void ft_send_cmd(struct ft_cmd *cmd)
  {
  	struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
  	struct se_cmd *se_cmd;
  	struct fcp_cmnd *fcp;
  	int data_dir;
  	u32 data_len;
  	int task_attr;
  	int ret;
  
  	fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
  	if (!fcp)
  		goto err;
  
  	if (fcp->fc_flags & FCP_CFL_LEN_MASK)
  		goto err;		/* not handling longer CDBs yet */
  
  	if (fcp->fc_tm_flags) {
  		task_attr = FCP_PTA_SIMPLE;
  		data_dir = DMA_NONE;
  		data_len = 0;
  	} else {
  		switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
  		case 0:
  			data_dir = DMA_NONE;
  			break;
  		case FCP_CFL_RDDATA:
  			data_dir = DMA_FROM_DEVICE;
  			break;
  		case FCP_CFL_WRDATA:
  			data_dir = DMA_TO_DEVICE;
  			break;
  		case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
  			goto err;	/* TBD not supported by tcm_fc yet */
  		}
  		/*
  		 * Locate the SAM Task Attr from fc_pri_ta
  		 */
  		switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
  		case FCP_PTA_HEADQ:
  			task_attr = MSG_HEAD_TAG;
  			break;
  		case FCP_PTA_ORDERED:
  			task_attr = MSG_ORDERED_TAG;
  			break;
  		case FCP_PTA_ACA:
  			task_attr = MSG_ACA_TAG;
  			break;
  		case FCP_PTA_SIMPLE: /* Fallthrough */
  		default:
  			task_attr = MSG_SIMPLE_TAG;
  		}
  
  		task_attr = fcp->fc_pri_ta & FCP_PTA_MASK;
  		data_len = ntohl(fcp->fc_dl);
  		cmd->cdb = fcp->fc_cdb;
  	}
  
  	se_cmd = &cmd->se_cmd;
  	/*
  	 * Initialize struct se_cmd descriptor from target_core_mod
  	 * infrastructure
  	 */
  	transport_init_se_cmd(se_cmd, &ft_configfs->tf_ops, cmd->sess->se_sess,
  			      data_len, data_dir, task_attr,
  			      &cmd->ft_sense_buffer[0]);
  	/*
  	 * Check for FCP task management flags
  	 */
  	if (fcp->fc_tm_flags) {
  		ft_send_tm(cmd);
  		return;
  	}
  
  	fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
  
  	cmd->lun = scsilun_to_int((struct scsi_lun *)fcp->fc_lun);
  	ret = transport_get_lun_for_cmd(&cmd->se_cmd, NULL, cmd->lun);
  	if (ret < 0) {
  		ft_dump_cmd(cmd, __func__);
  		transport_send_check_condition_and_sense(&cmd->se_cmd,
  			cmd->se_cmd.scsi_sense_reason, 0);
  		return;
  	}
  
  	ret = transport_generic_allocate_tasks(se_cmd, cmd->cdb);
  
  	FT_IO_DBG("r_ctl %x alloc task ret %d\n", fh->fh_r_ctl, ret);
  	ft_dump_cmd(cmd, __func__);
  
  	if (ret == -1) {
  		transport_send_check_condition_and_sense(se_cmd,
  				TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
  		transport_generic_free_cmd(se_cmd, 0, 1, 0);
  		return;
  	}
  	if (ret == -2) {
  		if (se_cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
  			ft_queue_status(se_cmd);
  		else
  			transport_send_check_condition_and_sense(se_cmd,
  					se_cmd->scsi_sense_reason, 0);
  		transport_generic_free_cmd(se_cmd, 0, 1, 0);
  		return;
  	}
  	transport_generic_handle_cdb(se_cmd);
  	return;
  
  err:
  	ft_send_resp_code(cmd, FCP_CMND_FIELDS_INVALID);
  	return;
  }
  
  /*
   * Handle request in the command thread.
   */
  static void ft_exec_req(struct ft_cmd *cmd)
  {
  	FT_IO_DBG("cmd state %x\n", cmd->state);
  	switch (cmd->state) {
  	case FC_CMD_ST_NEW:
  		ft_send_cmd(cmd);
  		break;
  	default:
  		break;
  	}
  }
  
  /*
   * Processing thread.
   * Currently one thread per tpg.
   */
  int ft_thread(void *arg)
  {
  	struct ft_tpg *tpg = arg;
  	struct se_queue_obj *qobj = &tpg->qobj;
  	struct ft_cmd *cmd;
  	int ret;
  
  	set_user_nice(current, -20);
  
  	while (!kthread_should_stop()) {
  		ret = wait_event_interruptible(qobj->thread_wq,
  			atomic_read(&qobj->queue_cnt) || kthread_should_stop());
  		if (ret < 0 || kthread_should_stop())
  			goto out;
  		cmd = ft_dequeue_cmd(qobj);
  		if (cmd)
  			ft_exec_req(cmd);
  	}
  
  out:
  	return 0;
  }
  