xref: /linux/drivers/target/tcm_fc/tfc_cmd.c (revision d229807f669ba3dea9f64467ee965051c4366aed)
1 /*
2  * Copyright (c) 2010 Cisco Systems, Inc.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms and conditions of the GNU General Public License,
6  * version 2, as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope it will be useful, but WITHOUT
9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11  * more details.
12  *
13  * You should have received a copy of the GNU General Public License along with
14  * this program; if not, write to the Free Software Foundation, Inc.,
15  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
16  */
17 
18 /* XXX TBD some includes may be extraneous */
19 
20 #include <linux/module.h>
21 #include <linux/moduleparam.h>
22 #include <generated/utsrelease.h>
23 #include <linux/utsname.h>
24 #include <linux/init.h>
25 #include <linux/slab.h>
26 #include <linux/kthread.h>
27 #include <linux/types.h>
28 #include <linux/string.h>
29 #include <linux/configfs.h>
30 #include <linux/ctype.h>
31 #include <linux/hash.h>
32 #include <asm/unaligned.h>
33 #include <scsi/scsi.h>
34 #include <scsi/scsi_host.h>
35 #include <scsi/scsi_device.h>
36 #include <scsi/scsi_cmnd.h>
37 #include <scsi/scsi_tcq.h>
38 #include <scsi/libfc.h>
39 #include <scsi/fc_encode.h>
40 
41 #include <target/target_core_base.h>
42 #include <target/target_core_transport.h>
43 #include <target/target_core_fabric_ops.h>
44 #include <target/target_core_device.h>
45 #include <target/target_core_tpg.h>
46 #include <target/target_core_configfs.h>
47 #include <target/target_core_tmr.h>
48 #include <target/configfs_macros.h>
49 
50 #include "tcm_fc.h"
51 
52 /*
53  * Dump cmd state for debugging.
54  */
55 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
56 {
57 	struct fc_exch *ep;
58 	struct fc_seq *sp;
59 	struct se_cmd *se_cmd;
60 	struct scatterlist *sg;
61 	int count;
62 
63 	se_cmd = &cmd->se_cmd;
64 	pr_debug("%s: cmd %p sess %p seq %p se_cmd %p\n",
65 		caller, cmd, cmd->sess, cmd->seq, se_cmd);
66 	pr_debug("%s: cmd %p cdb %p\n",
67 		caller, cmd, cmd->cdb);
68 	pr_debug("%s: cmd %p lun %d\n", caller, cmd, cmd->lun);
69 
70 	pr_debug("%s: cmd %p data_nents %u len %u se_cmd_flags <0x%x>\n",
71 		caller, cmd, se_cmd->t_data_nents,
72 	       se_cmd->data_length, se_cmd->se_cmd_flags);
73 
74 	for_each_sg(se_cmd->t_data_sg, sg, se_cmd->t_data_nents, count)
75 		pr_debug("%s: cmd %p sg %p page %p "
76 			"len 0x%x off 0x%x\n",
77 			caller, cmd, sg,
78 			sg_page(sg), sg->length, sg->offset);
79 
80 	sp = cmd->seq;
81 	if (sp) {
82 		ep = fc_seq_exch(sp);
83 		pr_debug("%s: cmd %p sid %x did %x "
84 			"ox_id %x rx_id %x seq_id %x e_stat %x\n",
85 			caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
86 			sp->id, ep->esb_stat);
87 	}
88 	print_hex_dump(KERN_INFO, "ft_dump_cmd ", DUMP_PREFIX_NONE,
89 		16, 4, cmd->cdb, MAX_COMMAND_SIZE, 0);
90 }
91 
92 static void ft_free_cmd(struct ft_cmd *cmd)
93 {
94 	struct fc_frame *fp;
95 	struct fc_lport *lport;
96 
97 	if (!cmd)
98 		return;
99 	fp = cmd->req_frame;
100 	lport = fr_dev(fp);
101 	if (fr_seq(fp))
102 		lport->tt.seq_release(fr_seq(fp));
103 	fc_frame_free(fp);
104 	ft_sess_put(cmd->sess);	/* undo get from lookup at recv */
105 	kfree(cmd);
106 }
107 
108 void ft_release_cmd(struct se_cmd *se_cmd)
109 {
110 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
111 
112 	ft_free_cmd(cmd);
113 }
114 
115 void ft_check_stop_free(struct se_cmd *se_cmd)
116 {
117 	transport_generic_free_cmd(se_cmd, 0);
118 }
119 
120 /*
121  * Send response.
122  */
123 int ft_queue_status(struct se_cmd *se_cmd)
124 {
125 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
126 	struct fc_frame *fp;
127 	struct fcp_resp_with_ext *fcp;
128 	struct fc_lport *lport;
129 	struct fc_exch *ep;
130 	size_t len;
131 
132 	ft_dump_cmd(cmd, __func__);
133 	ep = fc_seq_exch(cmd->seq);
134 	lport = ep->lp;
135 	len = sizeof(*fcp) + se_cmd->scsi_sense_length;
136 	fp = fc_frame_alloc(lport, len);
137 	if (!fp) {
138 		/* XXX shouldn't just drop it - requeue and retry? */
139 		return 0;
140 	}
141 	fcp = fc_frame_payload_get(fp, len);
142 	memset(fcp, 0, len);
143 	fcp->resp.fr_status = se_cmd->scsi_status;
144 
145 	len = se_cmd->scsi_sense_length;
146 	if (len) {
147 		fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
148 		fcp->ext.fr_sns_len = htonl(len);
149 		memcpy((fcp + 1), se_cmd->sense_buffer, len);
150 	}
151 
152 	/*
153 	 * Test underflow and overflow with one mask.  Usually both are off.
154 	 * Bidirectional commands are not handled yet.
155 	 */
156 	if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
157 		if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
158 			fcp->resp.fr_flags |= FCP_RESID_OVER;
159 		else
160 			fcp->resp.fr_flags |= FCP_RESID_UNDER;
161 		fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
162 	}
163 
164 	/*
165 	 * Send response.
166 	 */
167 	cmd->seq = lport->tt.seq_start_next(cmd->seq);
168 	fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
169 		       FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
170 
171 	lport->tt.seq_send(lport, cmd->seq, fp);
172 	lport->tt.exch_done(cmd->seq);
173 	return 0;
174 }
175 
176 int ft_write_pending_status(struct se_cmd *se_cmd)
177 {
178 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
179 
180 	return cmd->write_data_len != se_cmd->data_length;
181 }
182 
183 /*
184  * Send TX_RDY (transfer ready).
185  */
186 int ft_write_pending(struct se_cmd *se_cmd)
187 {
188 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
189 	struct fc_frame *fp;
190 	struct fcp_txrdy *txrdy;
191 	struct fc_lport *lport;
192 	struct fc_exch *ep;
193 	struct fc_frame_header *fh;
194 	u32 f_ctl;
195 
196 	ft_dump_cmd(cmd, __func__);
197 
198 	ep = fc_seq_exch(cmd->seq);
199 	lport = ep->lp;
200 	fp = fc_frame_alloc(lport, sizeof(*txrdy));
201 	if (!fp)
202 		return PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
203 
204 	txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
205 	memset(txrdy, 0, sizeof(*txrdy));
206 	txrdy->ft_burst_len = htonl(se_cmd->data_length);
207 
208 	cmd->seq = lport->tt.seq_start_next(cmd->seq);
209 	fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
210 		       FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
211 
212 	fh = fc_frame_header_get(fp);
213 	f_ctl = ntoh24(fh->fh_f_ctl);
214 
215 	/* Only if it is 'Exchange Responder' */
216 	if (f_ctl & FC_FC_EX_CTX) {
217 		/* Target is 'exchange responder' and sending XFER_READY
218 		 * to 'exchange initiator (initiator)'
219 		 */
220 		if ((ep->xid <= lport->lro_xid) &&
221 		    (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
222 			if (se_cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) {
223 				/*
224 				 * cmd may have been broken up into multiple
225 				 * tasks. Link their sgs together so we can
226 				 * operate on them all at once.
227 				 */
228 				transport_do_task_sg_chain(se_cmd);
229 				cmd->sg = se_cmd->t_tasks_sg_chained;
230 				cmd->sg_cnt =
231 					se_cmd->t_tasks_sg_chained_no;
232 			}
233 			if (cmd->sg && lport->tt.ddp_target(lport, ep->xid,
234 							    cmd->sg,
235 							    cmd->sg_cnt))
236 				cmd->was_ddp_setup = 1;
237 		}
238 	}
239 	lport->tt.seq_send(lport, cmd->seq, fp);
240 	return 0;
241 }
242 
243 u32 ft_get_task_tag(struct se_cmd *se_cmd)
244 {
245 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
246 
247 	return fc_seq_exch(cmd->seq)->rxid;
248 }
249 
250 int ft_get_cmd_state(struct se_cmd *se_cmd)
251 {
252 	return 0;
253 }
254 
255 int ft_is_state_remove(struct se_cmd *se_cmd)
256 {
257 	return 0;	/* XXX TBD */
258 }
259 
260 /*
261  * FC sequence response handler for follow-on sequences (data) and aborts.
262  */
263 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
264 {
265 	struct ft_cmd *cmd = arg;
266 	struct fc_frame_header *fh;
267 
268 	if (IS_ERR(fp)) {
269 		/* XXX need to find cmd if queued */
270 		cmd->seq = NULL;
271 		transport_generic_free_cmd(&cmd->se_cmd, 0);
272 		return;
273 	}
274 
275 	fh = fc_frame_header_get(fp);
276 
277 	switch (fh->fh_r_ctl) {
278 	case FC_RCTL_DD_SOL_DATA:	/* write data */
279 		ft_recv_write_data(cmd, fp);
280 		break;
281 	case FC_RCTL_DD_UNSOL_CTL:	/* command */
282 	case FC_RCTL_DD_SOL_CTL:	/* transfer ready */
283 	case FC_RCTL_DD_DATA_DESC:	/* transfer ready */
284 	default:
285 		pr_debug("%s: unhandled frame r_ctl %x\n",
286 		       __func__, fh->fh_r_ctl);
287 		ft_invl_hw_context(cmd);
288 		fc_frame_free(fp);
289 		transport_generic_free_cmd(&cmd->se_cmd, 0);
290 		break;
291 	}
292 }
293 
294 /*
295  * Send a FCP response including SCSI status and optional FCP rsp_code.
296  * status is SAM_STAT_GOOD (zero) iff code is valid.
297  * This is used in error cases, such as allocation failures.
298  */
299 static void ft_send_resp_status(struct fc_lport *lport,
300 				const struct fc_frame *rx_fp,
301 				u32 status, enum fcp_resp_rsp_codes code)
302 {
303 	struct fc_frame *fp;
304 	struct fc_seq *sp;
305 	const struct fc_frame_header *fh;
306 	size_t len;
307 	struct fcp_resp_with_ext *fcp;
308 	struct fcp_resp_rsp_info *info;
309 
310 	fh = fc_frame_header_get(rx_fp);
311 	pr_debug("FCP error response: did %x oxid %x status %x code %x\n",
312 		  ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
313 	len = sizeof(*fcp);
314 	if (status == SAM_STAT_GOOD)
315 		len += sizeof(*info);
316 	fp = fc_frame_alloc(lport, len);
317 	if (!fp)
318 		return;
319 	fcp = fc_frame_payload_get(fp, len);
320 	memset(fcp, 0, len);
321 	fcp->resp.fr_status = status;
322 	if (status == SAM_STAT_GOOD) {
323 		fcp->ext.fr_rsp_len = htonl(sizeof(*info));
324 		fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
325 		info = (struct fcp_resp_rsp_info *)(fcp + 1);
326 		info->rsp_code = code;
327 	}
328 
329 	fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
330 	sp = fr_seq(fp);
331 	if (sp)
332 		lport->tt.seq_send(lport, sp, fp);
333 	else
334 		lport->tt.frame_send(lport, fp);
335 }
336 
337 /*
338  * Send error or task management response.
339  */
340 static void ft_send_resp_code(struct ft_cmd *cmd,
341 			      enum fcp_resp_rsp_codes code)
342 {
343 	ft_send_resp_status(cmd->sess->tport->lport,
344 			    cmd->req_frame, SAM_STAT_GOOD, code);
345 }
346 
347 
348 /*
349  * Send error or task management response.
350  * Always frees the cmd and associated state.
351  */
352 static void ft_send_resp_code_and_free(struct ft_cmd *cmd,
353 				      enum fcp_resp_rsp_codes code)
354 {
355 	ft_send_resp_code(cmd, code);
356 	ft_free_cmd(cmd);
357 }
358 
359 /*
360  * Handle Task Management Request.
361  */
362 static void ft_send_tm(struct ft_cmd *cmd)
363 {
364 	struct se_tmr_req *tmr;
365 	struct fcp_cmnd *fcp;
366 	struct ft_sess *sess;
367 	u8 tm_func;
368 
369 	fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
370 
371 	switch (fcp->fc_tm_flags) {
372 	case FCP_TMF_LUN_RESET:
373 		tm_func = TMR_LUN_RESET;
374 		break;
375 	case FCP_TMF_TGT_RESET:
376 		tm_func = TMR_TARGET_WARM_RESET;
377 		break;
378 	case FCP_TMF_CLR_TASK_SET:
379 		tm_func = TMR_CLEAR_TASK_SET;
380 		break;
381 	case FCP_TMF_ABT_TASK_SET:
382 		tm_func = TMR_ABORT_TASK_SET;
383 		break;
384 	case FCP_TMF_CLR_ACA:
385 		tm_func = TMR_CLEAR_ACA;
386 		break;
387 	default:
388 		/*
389 		 * FCP4r01 indicates having a combination of
390 		 * tm_flags set is invalid.
391 		 */
392 		pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
393 		ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
394 		return;
395 	}
396 
397 	pr_debug("alloc tm cmd fn %d\n", tm_func);
398 	tmr = core_tmr_alloc_req(&cmd->se_cmd, cmd, tm_func, GFP_KERNEL);
399 	if (!tmr) {
400 		pr_debug("alloc failed\n");
401 		ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED);
402 		return;
403 	}
404 	cmd->se_cmd.se_tmr_req = tmr;
405 
406 	switch (fcp->fc_tm_flags) {
407 	case FCP_TMF_LUN_RESET:
408 		cmd->lun = scsilun_to_int((struct scsi_lun *)fcp->fc_lun);
409 		if (transport_lookup_tmr_lun(&cmd->se_cmd, cmd->lun) < 0) {
410 			/*
411 			 * Make sure to clean up newly allocated TMR request
412 			 * since "unable to  handle TMR request because failed
413 			 * to get to LUN"
414 			 */
415 			pr_debug("Failed to get LUN for TMR func %d, "
416 				  "se_cmd %p, unpacked_lun %d\n",
417 				  tm_func, &cmd->se_cmd, cmd->lun);
418 			ft_dump_cmd(cmd, __func__);
419 			sess = cmd->sess;
420 			transport_send_check_condition_and_sense(&cmd->se_cmd,
421 				cmd->se_cmd.scsi_sense_reason, 0);
422 			transport_generic_free_cmd(&cmd->se_cmd, 0);
423 			ft_sess_put(sess);
424 			return;
425 		}
426 		break;
427 	case FCP_TMF_TGT_RESET:
428 	case FCP_TMF_CLR_TASK_SET:
429 	case FCP_TMF_ABT_TASK_SET:
430 	case FCP_TMF_CLR_ACA:
431 		break;
432 	default:
433 		return;
434 	}
435 	transport_generic_handle_tmr(&cmd->se_cmd);
436 }
437 
438 /*
439  * Send status from completed task management request.
440  */
441 int ft_queue_tm_resp(struct se_cmd *se_cmd)
442 {
443 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
444 	struct se_tmr_req *tmr = se_cmd->se_tmr_req;
445 	enum fcp_resp_rsp_codes code;
446 
447 	switch (tmr->response) {
448 	case TMR_FUNCTION_COMPLETE:
449 		code = FCP_TMF_CMPL;
450 		break;
451 	case TMR_LUN_DOES_NOT_EXIST:
452 		code = FCP_TMF_INVALID_LUN;
453 		break;
454 	case TMR_FUNCTION_REJECTED:
455 		code = FCP_TMF_REJECTED;
456 		break;
457 	case TMR_TASK_DOES_NOT_EXIST:
458 	case TMR_TASK_STILL_ALLEGIANT:
459 	case TMR_TASK_FAILOVER_NOT_SUPPORTED:
460 	case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
461 	case TMR_FUNCTION_AUTHORIZATION_FAILED:
462 	default:
463 		code = FCP_TMF_FAILED;
464 		break;
465 	}
466 	pr_debug("tmr fn %d resp %d fcp code %d\n",
467 		  tmr->function, tmr->response, code);
468 	ft_send_resp_code(cmd, code);
469 	return 0;
470 }
471 
472 static void ft_send_work(struct work_struct *work);
473 
474 /*
475  * Handle incoming FCP command.
476  */
477 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
478 {
479 	struct ft_cmd *cmd;
480 	struct fc_lport *lport = sess->tport->lport;
481 
482 	cmd = kzalloc(sizeof(*cmd), GFP_ATOMIC);
483 	if (!cmd)
484 		goto busy;
485 	cmd->sess = sess;
486 	cmd->seq = lport->tt.seq_assign(lport, fp);
487 	if (!cmd->seq) {
488 		kfree(cmd);
489 		goto busy;
490 	}
491 	cmd->req_frame = fp;		/* hold frame during cmd */
492 
493 	INIT_WORK(&cmd->work, ft_send_work);
494 	queue_work(sess->tport->tpg->workqueue, &cmd->work);
495 	return;
496 
497 busy:
498 	pr_debug("cmd or seq allocation failure - sending BUSY\n");
499 	ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
500 	fc_frame_free(fp);
501 	ft_sess_put(sess);		/* undo get from lookup */
502 }
503 
504 
505 /*
506  * Handle incoming FCP frame.
507  * Caller has verified that the frame is type FCP.
508  */
509 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
510 {
511 	struct fc_frame_header *fh = fc_frame_header_get(fp);
512 
513 	switch (fh->fh_r_ctl) {
514 	case FC_RCTL_DD_UNSOL_CMD:	/* command */
515 		ft_recv_cmd(sess, fp);
516 		break;
517 	case FC_RCTL_DD_SOL_DATA:	/* write data */
518 	case FC_RCTL_DD_UNSOL_CTL:
519 	case FC_RCTL_DD_SOL_CTL:
520 	case FC_RCTL_DD_DATA_DESC:	/* transfer ready */
521 	case FC_RCTL_ELS4_REQ:		/* SRR, perhaps */
522 	default:
523 		pr_debug("%s: unhandled frame r_ctl %x\n",
524 		       __func__, fh->fh_r_ctl);
525 		fc_frame_free(fp);
526 		ft_sess_put(sess);	/* undo get from lookup */
527 		break;
528 	}
529 }
530 
531 /*
532  * Send new command to target.
533  */
534 static void ft_send_work(struct work_struct *work)
535 {
536 	struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
537 	struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
538 	struct se_cmd *se_cmd;
539 	struct fcp_cmnd *fcp;
540 	int data_dir = 0;
541 	u32 data_len;
542 	int task_attr;
543 	int ret;
544 
545 	fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
546 	if (!fcp)
547 		goto err;
548 
549 	if (fcp->fc_flags & FCP_CFL_LEN_MASK)
550 		goto err;		/* not handling longer CDBs yet */
551 
552 	if (fcp->fc_tm_flags) {
553 		task_attr = FCP_PTA_SIMPLE;
554 		data_dir = DMA_NONE;
555 		data_len = 0;
556 	} else {
557 		switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
558 		case 0:
559 			data_dir = DMA_NONE;
560 			break;
561 		case FCP_CFL_RDDATA:
562 			data_dir = DMA_FROM_DEVICE;
563 			break;
564 		case FCP_CFL_WRDATA:
565 			data_dir = DMA_TO_DEVICE;
566 			break;
567 		case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
568 			goto err;	/* TBD not supported by tcm_fc yet */
569 		}
570 		/*
571 		 * Locate the SAM Task Attr from fc_pri_ta
572 		 */
573 		switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
574 		case FCP_PTA_HEADQ:
575 			task_attr = MSG_HEAD_TAG;
576 			break;
577 		case FCP_PTA_ORDERED:
578 			task_attr = MSG_ORDERED_TAG;
579 			break;
580 		case FCP_PTA_ACA:
581 			task_attr = MSG_ACA_TAG;
582 			break;
583 		case FCP_PTA_SIMPLE: /* Fallthrough */
584 		default:
585 			task_attr = MSG_SIMPLE_TAG;
586 		}
587 
588 
589 		task_attr = fcp->fc_pri_ta & FCP_PTA_MASK;
590 		data_len = ntohl(fcp->fc_dl);
591 		cmd->cdb = fcp->fc_cdb;
592 	}
593 
594 	se_cmd = &cmd->se_cmd;
595 	/*
596 	 * Initialize struct se_cmd descriptor from target_core_mod
597 	 * infrastructure
598 	 */
599 	transport_init_se_cmd(se_cmd, &ft_configfs->tf_ops, cmd->sess->se_sess,
600 			      data_len, data_dir, task_attr,
601 			      &cmd->ft_sense_buffer[0]);
602 	/*
603 	 * Check for FCP task management flags
604 	 */
605 	if (fcp->fc_tm_flags) {
606 		ft_send_tm(cmd);
607 		return;
608 	}
609 
610 	fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
611 
612 	cmd->lun = scsilun_to_int((struct scsi_lun *)fcp->fc_lun);
613 	ret = transport_lookup_cmd_lun(&cmd->se_cmd, cmd->lun);
614 	if (ret < 0) {
615 		ft_dump_cmd(cmd, __func__);
616 		transport_send_check_condition_and_sense(&cmd->se_cmd,
617 			cmd->se_cmd.scsi_sense_reason, 0);
618 		return;
619 	}
620 
621 	ret = transport_generic_allocate_tasks(se_cmd, cmd->cdb);
622 
623 	pr_debug("r_ctl %x alloc task ret %d\n", fh->fh_r_ctl, ret);
624 	ft_dump_cmd(cmd, __func__);
625 
626 	if (ret == -ENOMEM) {
627 		transport_send_check_condition_and_sense(se_cmd,
628 				TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
629 		transport_generic_free_cmd(se_cmd, 0);
630 		return;
631 	}
632 	if (ret == -EINVAL) {
633 		if (se_cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
634 			ft_queue_status(se_cmd);
635 		else
636 			transport_send_check_condition_and_sense(se_cmd,
637 					se_cmd->scsi_sense_reason, 0);
638 		transport_generic_free_cmd(se_cmd, 0);
639 		return;
640 	}
641 	transport_handle_cdb_direct(se_cmd);
642 	return;
643 
644 err:
645 	ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
646 }
647