xref: /linux/drivers/target/tcm_fc/tfc_cmd.c (revision 068df0f34e81bc06c5eb5012ec2eda25624e87aa)
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 int ft_check_stop_free(struct se_cmd *se_cmd)
116 {
117 	transport_generic_free_cmd(se_cmd, 0);
118 	return 1;
119 }
120 
121 /*
122  * Send response.
123  */
124 int ft_queue_status(struct se_cmd *se_cmd)
125 {
126 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
127 	struct fc_frame *fp;
128 	struct fcp_resp_with_ext *fcp;
129 	struct fc_lport *lport;
130 	struct fc_exch *ep;
131 	size_t len;
132 
133 	ft_dump_cmd(cmd, __func__);
134 	ep = fc_seq_exch(cmd->seq);
135 	lport = ep->lp;
136 	len = sizeof(*fcp) + se_cmd->scsi_sense_length;
137 	fp = fc_frame_alloc(lport, len);
138 	if (!fp) {
139 		/* XXX shouldn't just drop it - requeue and retry? */
140 		return 0;
141 	}
142 	fcp = fc_frame_payload_get(fp, len);
143 	memset(fcp, 0, len);
144 	fcp->resp.fr_status = se_cmd->scsi_status;
145 
146 	len = se_cmd->scsi_sense_length;
147 	if (len) {
148 		fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
149 		fcp->ext.fr_sns_len = htonl(len);
150 		memcpy((fcp + 1), se_cmd->sense_buffer, len);
151 	}
152 
153 	/*
154 	 * Test underflow and overflow with one mask.  Usually both are off.
155 	 * Bidirectional commands are not handled yet.
156 	 */
157 	if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
158 		if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
159 			fcp->resp.fr_flags |= FCP_RESID_OVER;
160 		else
161 			fcp->resp.fr_flags |= FCP_RESID_UNDER;
162 		fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
163 	}
164 
165 	/*
166 	 * Send response.
167 	 */
168 	cmd->seq = lport->tt.seq_start_next(cmd->seq);
169 	fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
170 		       FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
171 
172 	lport->tt.seq_send(lport, cmd->seq, fp);
173 	lport->tt.exch_done(cmd->seq);
174 	return 0;
175 }
176 
177 int ft_write_pending_status(struct se_cmd *se_cmd)
178 {
179 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
180 
181 	return cmd->write_data_len != se_cmd->data_length;
182 }
183 
184 /*
185  * Send TX_RDY (transfer ready).
186  */
187 int ft_write_pending(struct se_cmd *se_cmd)
188 {
189 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
190 	struct fc_frame *fp;
191 	struct fcp_txrdy *txrdy;
192 	struct fc_lport *lport;
193 	struct fc_exch *ep;
194 	struct fc_frame_header *fh;
195 	u32 f_ctl;
196 
197 	ft_dump_cmd(cmd, __func__);
198 
199 	ep = fc_seq_exch(cmd->seq);
200 	lport = ep->lp;
201 	fp = fc_frame_alloc(lport, sizeof(*txrdy));
202 	if (!fp)
203 		return PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
204 
205 	txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
206 	memset(txrdy, 0, sizeof(*txrdy));
207 	txrdy->ft_burst_len = htonl(se_cmd->data_length);
208 
209 	cmd->seq = lport->tt.seq_start_next(cmd->seq);
210 	fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
211 		       FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
212 
213 	fh = fc_frame_header_get(fp);
214 	f_ctl = ntoh24(fh->fh_f_ctl);
215 
216 	/* Only if it is 'Exchange Responder' */
217 	if (f_ctl & FC_FC_EX_CTX) {
218 		/* Target is 'exchange responder' and sending XFER_READY
219 		 * to 'exchange initiator (initiator)'
220 		 */
221 		if ((ep->xid <= lport->lro_xid) &&
222 		    (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
223 			if (se_cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) {
224 				/*
225 				 * cmd may have been broken up into multiple
226 				 * tasks. Link their sgs together so we can
227 				 * operate on them all at once.
228 				 */
229 				transport_do_task_sg_chain(se_cmd);
230 				cmd->sg = se_cmd->t_tasks_sg_chained;
231 				cmd->sg_cnt =
232 					se_cmd->t_tasks_sg_chained_no;
233 			}
234 			if (cmd->sg && lport->tt.ddp_target(lport, ep->xid,
235 							    cmd->sg,
236 							    cmd->sg_cnt))
237 				cmd->was_ddp_setup = 1;
238 		}
239 	}
240 	lport->tt.seq_send(lport, cmd->seq, fp);
241 	return 0;
242 }
243 
244 u32 ft_get_task_tag(struct se_cmd *se_cmd)
245 {
246 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
247 
248 	return fc_seq_exch(cmd->seq)->rxid;
249 }
250 
251 int ft_get_cmd_state(struct se_cmd *se_cmd)
252 {
253 	return 0;
254 }
255 
256 int ft_is_state_remove(struct se_cmd *se_cmd)
257 {
258 	return 0;	/* XXX TBD */
259 }
260 
261 /*
262  * FC sequence response handler for follow-on sequences (data) and aborts.
263  */
264 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
265 {
266 	struct ft_cmd *cmd = arg;
267 	struct fc_frame_header *fh;
268 
269 	if (IS_ERR(fp)) {
270 		/* XXX need to find cmd if queued */
271 		cmd->seq = NULL;
272 		transport_generic_free_cmd(&cmd->se_cmd, 0);
273 		return;
274 	}
275 
276 	fh = fc_frame_header_get(fp);
277 
278 	switch (fh->fh_r_ctl) {
279 	case FC_RCTL_DD_SOL_DATA:	/* write data */
280 		ft_recv_write_data(cmd, fp);
281 		break;
282 	case FC_RCTL_DD_UNSOL_CTL:	/* command */
283 	case FC_RCTL_DD_SOL_CTL:	/* transfer ready */
284 	case FC_RCTL_DD_DATA_DESC:	/* transfer ready */
285 	default:
286 		pr_debug("%s: unhandled frame r_ctl %x\n",
287 		       __func__, fh->fh_r_ctl);
288 		ft_invl_hw_context(cmd);
289 		fc_frame_free(fp);
290 		transport_generic_free_cmd(&cmd->se_cmd, 0);
291 		break;
292 	}
293 }
294 
295 /*
296  * Send a FCP response including SCSI status and optional FCP rsp_code.
297  * status is SAM_STAT_GOOD (zero) iff code is valid.
298  * This is used in error cases, such as allocation failures.
299  */
300 static void ft_send_resp_status(struct fc_lport *lport,
301 				const struct fc_frame *rx_fp,
302 				u32 status, enum fcp_resp_rsp_codes code)
303 {
304 	struct fc_frame *fp;
305 	struct fc_seq *sp;
306 	const struct fc_frame_header *fh;
307 	size_t len;
308 	struct fcp_resp_with_ext *fcp;
309 	struct fcp_resp_rsp_info *info;
310 
311 	fh = fc_frame_header_get(rx_fp);
312 	pr_debug("FCP error response: did %x oxid %x status %x code %x\n",
313 		  ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
314 	len = sizeof(*fcp);
315 	if (status == SAM_STAT_GOOD)
316 		len += sizeof(*info);
317 	fp = fc_frame_alloc(lport, len);
318 	if (!fp)
319 		return;
320 	fcp = fc_frame_payload_get(fp, len);
321 	memset(fcp, 0, len);
322 	fcp->resp.fr_status = status;
323 	if (status == SAM_STAT_GOOD) {
324 		fcp->ext.fr_rsp_len = htonl(sizeof(*info));
325 		fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
326 		info = (struct fcp_resp_rsp_info *)(fcp + 1);
327 		info->rsp_code = code;
328 	}
329 
330 	fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
331 	sp = fr_seq(fp);
332 	if (sp)
333 		lport->tt.seq_send(lport, sp, fp);
334 	else
335 		lport->tt.frame_send(lport, fp);
336 }
337 
338 /*
339  * Send error or task management response.
340  */
341 static void ft_send_resp_code(struct ft_cmd *cmd,
342 			      enum fcp_resp_rsp_codes code)
343 {
344 	ft_send_resp_status(cmd->sess->tport->lport,
345 			    cmd->req_frame, SAM_STAT_GOOD, code);
346 }
347 
348 
349 /*
350  * Send error or task management response.
351  * Always frees the cmd and associated state.
352  */
353 static void ft_send_resp_code_and_free(struct ft_cmd *cmd,
354 				      enum fcp_resp_rsp_codes code)
355 {
356 	ft_send_resp_code(cmd, code);
357 	ft_free_cmd(cmd);
358 }
359 
360 /*
361  * Handle Task Management Request.
362  */
363 static void ft_send_tm(struct ft_cmd *cmd)
364 {
365 	struct se_tmr_req *tmr;
366 	struct fcp_cmnd *fcp;
367 	struct ft_sess *sess;
368 	u8 tm_func;
369 
370 	fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
371 
372 	switch (fcp->fc_tm_flags) {
373 	case FCP_TMF_LUN_RESET:
374 		tm_func = TMR_LUN_RESET;
375 		break;
376 	case FCP_TMF_TGT_RESET:
377 		tm_func = TMR_TARGET_WARM_RESET;
378 		break;
379 	case FCP_TMF_CLR_TASK_SET:
380 		tm_func = TMR_CLEAR_TASK_SET;
381 		break;
382 	case FCP_TMF_ABT_TASK_SET:
383 		tm_func = TMR_ABORT_TASK_SET;
384 		break;
385 	case FCP_TMF_CLR_ACA:
386 		tm_func = TMR_CLEAR_ACA;
387 		break;
388 	default:
389 		/*
390 		 * FCP4r01 indicates having a combination of
391 		 * tm_flags set is invalid.
392 		 */
393 		pr_debug("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
394 		ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
395 		return;
396 	}
397 
398 	pr_debug("alloc tm cmd fn %d\n", tm_func);
399 	tmr = core_tmr_alloc_req(&cmd->se_cmd, cmd, tm_func, GFP_KERNEL);
400 	if (!tmr) {
401 		pr_debug("alloc failed\n");
402 		ft_send_resp_code_and_free(cmd, FCP_TMF_FAILED);
403 		return;
404 	}
405 	cmd->se_cmd.se_tmr_req = tmr;
406 
407 	switch (fcp->fc_tm_flags) {
408 	case FCP_TMF_LUN_RESET:
409 		cmd->lun = scsilun_to_int((struct scsi_lun *)fcp->fc_lun);
410 		if (transport_lookup_tmr_lun(&cmd->se_cmd, cmd->lun) < 0) {
411 			/*
412 			 * Make sure to clean up newly allocated TMR request
413 			 * since "unable to  handle TMR request because failed
414 			 * to get to LUN"
415 			 */
416 			pr_debug("Failed to get LUN for TMR func %d, "
417 				  "se_cmd %p, unpacked_lun %d\n",
418 				  tm_func, &cmd->se_cmd, cmd->lun);
419 			ft_dump_cmd(cmd, __func__);
420 			sess = cmd->sess;
421 			transport_send_check_condition_and_sense(&cmd->se_cmd,
422 				cmd->se_cmd.scsi_sense_reason, 0);
423 			transport_generic_free_cmd(&cmd->se_cmd, 0);
424 			ft_sess_put(sess);
425 			return;
426 		}
427 		break;
428 	case FCP_TMF_TGT_RESET:
429 	case FCP_TMF_CLR_TASK_SET:
430 	case FCP_TMF_ABT_TASK_SET:
431 	case FCP_TMF_CLR_ACA:
432 		break;
433 	default:
434 		return;
435 	}
436 	transport_generic_handle_tmr(&cmd->se_cmd);
437 }
438 
439 /*
440  * Send status from completed task management request.
441  */
442 int ft_queue_tm_resp(struct se_cmd *se_cmd)
443 {
444 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
445 	struct se_tmr_req *tmr = se_cmd->se_tmr_req;
446 	enum fcp_resp_rsp_codes code;
447 
448 	switch (tmr->response) {
449 	case TMR_FUNCTION_COMPLETE:
450 		code = FCP_TMF_CMPL;
451 		break;
452 	case TMR_LUN_DOES_NOT_EXIST:
453 		code = FCP_TMF_INVALID_LUN;
454 		break;
455 	case TMR_FUNCTION_REJECTED:
456 		code = FCP_TMF_REJECTED;
457 		break;
458 	case TMR_TASK_DOES_NOT_EXIST:
459 	case TMR_TASK_STILL_ALLEGIANT:
460 	case TMR_TASK_FAILOVER_NOT_SUPPORTED:
461 	case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
462 	case TMR_FUNCTION_AUTHORIZATION_FAILED:
463 	default:
464 		code = FCP_TMF_FAILED;
465 		break;
466 	}
467 	pr_debug("tmr fn %d resp %d fcp code %d\n",
468 		  tmr->function, tmr->response, code);
469 	ft_send_resp_code(cmd, code);
470 	return 0;
471 }
472 
473 static void ft_send_work(struct work_struct *work);
474 
475 /*
476  * Handle incoming FCP command.
477  */
478 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
479 {
480 	struct ft_cmd *cmd;
481 	struct fc_lport *lport = sess->tport->lport;
482 
483 	cmd = kzalloc(sizeof(*cmd), GFP_ATOMIC);
484 	if (!cmd)
485 		goto busy;
486 	cmd->sess = sess;
487 	cmd->seq = lport->tt.seq_assign(lport, fp);
488 	if (!cmd->seq) {
489 		kfree(cmd);
490 		goto busy;
491 	}
492 	cmd->req_frame = fp;		/* hold frame during cmd */
493 
494 	INIT_WORK(&cmd->work, ft_send_work);
495 	queue_work(sess->tport->tpg->workqueue, &cmd->work);
496 	return;
497 
498 busy:
499 	pr_debug("cmd or seq allocation failure - sending BUSY\n");
500 	ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
501 	fc_frame_free(fp);
502 	ft_sess_put(sess);		/* undo get from lookup */
503 }
504 
505 
506 /*
507  * Handle incoming FCP frame.
508  * Caller has verified that the frame is type FCP.
509  */
510 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
511 {
512 	struct fc_frame_header *fh = fc_frame_header_get(fp);
513 
514 	switch (fh->fh_r_ctl) {
515 	case FC_RCTL_DD_UNSOL_CMD:	/* command */
516 		ft_recv_cmd(sess, fp);
517 		break;
518 	case FC_RCTL_DD_SOL_DATA:	/* write data */
519 	case FC_RCTL_DD_UNSOL_CTL:
520 	case FC_RCTL_DD_SOL_CTL:
521 	case FC_RCTL_DD_DATA_DESC:	/* transfer ready */
522 	case FC_RCTL_ELS4_REQ:		/* SRR, perhaps */
523 	default:
524 		pr_debug("%s: unhandled frame r_ctl %x\n",
525 		       __func__, fh->fh_r_ctl);
526 		fc_frame_free(fp);
527 		ft_sess_put(sess);	/* undo get from lookup */
528 		break;
529 	}
530 }
531 
532 /*
533  * Send new command to target.
534  */
535 static void ft_send_work(struct work_struct *work)
536 {
537 	struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
538 	struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
539 	struct se_cmd *se_cmd;
540 	struct fcp_cmnd *fcp;
541 	int data_dir = 0;
542 	u32 data_len;
543 	int task_attr;
544 	int ret;
545 
546 	fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
547 	if (!fcp)
548 		goto err;
549 
550 	if (fcp->fc_flags & FCP_CFL_LEN_MASK)
551 		goto err;		/* not handling longer CDBs yet */
552 
553 	if (fcp->fc_tm_flags) {
554 		task_attr = FCP_PTA_SIMPLE;
555 		data_dir = DMA_NONE;
556 		data_len = 0;
557 	} else {
558 		switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
559 		case 0:
560 			data_dir = DMA_NONE;
561 			break;
562 		case FCP_CFL_RDDATA:
563 			data_dir = DMA_FROM_DEVICE;
564 			break;
565 		case FCP_CFL_WRDATA:
566 			data_dir = DMA_TO_DEVICE;
567 			break;
568 		case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
569 			goto err;	/* TBD not supported by tcm_fc yet */
570 		}
571 		/*
572 		 * Locate the SAM Task Attr from fc_pri_ta
573 		 */
574 		switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
575 		case FCP_PTA_HEADQ:
576 			task_attr = MSG_HEAD_TAG;
577 			break;
578 		case FCP_PTA_ORDERED:
579 			task_attr = MSG_ORDERED_TAG;
580 			break;
581 		case FCP_PTA_ACA:
582 			task_attr = MSG_ACA_TAG;
583 			break;
584 		case FCP_PTA_SIMPLE: /* Fallthrough */
585 		default:
586 			task_attr = MSG_SIMPLE_TAG;
587 		}
588 
589 
590 		task_attr = fcp->fc_pri_ta & FCP_PTA_MASK;
591 		data_len = ntohl(fcp->fc_dl);
592 		cmd->cdb = fcp->fc_cdb;
593 	}
594 
595 	se_cmd = &cmd->se_cmd;
596 	/*
597 	 * Initialize struct se_cmd descriptor from target_core_mod
598 	 * infrastructure
599 	 */
600 	transport_init_se_cmd(se_cmd, &ft_configfs->tf_ops, cmd->sess->se_sess,
601 			      data_len, data_dir, task_attr,
602 			      &cmd->ft_sense_buffer[0]);
603 	/*
604 	 * Check for FCP task management flags
605 	 */
606 	if (fcp->fc_tm_flags) {
607 		ft_send_tm(cmd);
608 		return;
609 	}
610 
611 	fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
612 
613 	cmd->lun = scsilun_to_int((struct scsi_lun *)fcp->fc_lun);
614 	ret = transport_lookup_cmd_lun(&cmd->se_cmd, cmd->lun);
615 	if (ret < 0) {
616 		ft_dump_cmd(cmd, __func__);
617 		transport_send_check_condition_and_sense(&cmd->se_cmd,
618 			cmd->se_cmd.scsi_sense_reason, 0);
619 		return;
620 	}
621 
622 	ret = transport_generic_allocate_tasks(se_cmd, cmd->cdb);
623 
624 	pr_debug("r_ctl %x alloc task ret %d\n", fh->fh_r_ctl, ret);
625 	ft_dump_cmd(cmd, __func__);
626 
627 	if (ret == -ENOMEM) {
628 		transport_send_check_condition_and_sense(se_cmd,
629 				TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
630 		transport_generic_free_cmd(se_cmd, 0);
631 		return;
632 	}
633 	if (ret == -EINVAL) {
634 		if (se_cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
635 			ft_queue_status(se_cmd);
636 		else
637 			transport_send_check_condition_and_sense(se_cmd,
638 					se_cmd->scsi_sense_reason, 0);
639 		transport_generic_free_cmd(se_cmd, 0);
640 		return;
641 	}
642 	transport_handle_cdb_direct(se_cmd);
643 	return;
644 
645 err:
646 	ft_send_resp_code_and_free(cmd, FCP_CMND_FIELDS_INVALID);
647 }
648