xref: /linux/drivers/target/tcm_fc/tfc_cmd.c (revision 12871a0bd67dd4db4418e1daafcd46e9d329ef10)
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 <linux/version.h>
23 #include <generated/utsrelease.h>
24 #include <linux/utsname.h>
25 #include <linux/init.h>
26 #include <linux/slab.h>
27 #include <linux/kthread.h>
28 #include <linux/types.h>
29 #include <linux/string.h>
30 #include <linux/configfs.h>
31 #include <linux/ctype.h>
32 #include <linux/hash.h>
33 #include <asm/unaligned.h>
34 #include <scsi/scsi.h>
35 #include <scsi/scsi_host.h>
36 #include <scsi/scsi_device.h>
37 #include <scsi/scsi_cmnd.h>
38 #include <scsi/scsi_tcq.h>
39 #include <scsi/libfc.h>
40 #include <scsi/fc_encode.h>
41 
42 #include <target/target_core_base.h>
43 #include <target/target_core_transport.h>
44 #include <target/target_core_fabric_ops.h>
45 #include <target/target_core_device.h>
46 #include <target/target_core_tpg.h>
47 #include <target/target_core_configfs.h>
48 #include <target/target_core_base.h>
49 #include <target/target_core_tmr.h>
50 #include <target/configfs_macros.h>
51 
52 #include "tcm_fc.h"
53 
54 /*
55  * Dump cmd state for debugging.
56  */
57 void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
58 {
59 	struct fc_exch *ep;
60 	struct fc_seq *sp;
61 	struct se_cmd *se_cmd;
62 	struct se_mem *mem;
63 	struct se_transport_task *task;
64 
65 	if (!(ft_debug_logging & FT_DEBUG_IO))
66 		return;
67 
68 	se_cmd = &cmd->se_cmd;
69 	printk(KERN_INFO "%s: cmd %p state %d sess %p seq %p se_cmd %p\n",
70 		caller, cmd, cmd->state, cmd->sess, cmd->seq, se_cmd);
71 	printk(KERN_INFO "%s: cmd %p cdb %p\n",
72 		caller, cmd, cmd->cdb);
73 	printk(KERN_INFO "%s: cmd %p lun %d\n", caller, cmd, cmd->lun);
74 
75 	task = T_TASK(se_cmd);
76 	printk(KERN_INFO "%s: cmd %p task %p se_num %u buf %p len %u se_cmd_flags <0x%x>\n",
77 	       caller, cmd, task, task->t_tasks_se_num,
78 	       task->t_task_buf, se_cmd->data_length, se_cmd->se_cmd_flags);
79 	if (task->t_mem_list)
80 		list_for_each_entry(mem, task->t_mem_list, se_list)
81 			printk(KERN_INFO "%s: cmd %p mem %p page %p "
82 			       "len 0x%x off 0x%x\n",
83 			       caller, cmd, mem,
84 			       mem->se_page, mem->se_len, mem->se_off);
85 	sp = cmd->seq;
86 	if (sp) {
87 		ep = fc_seq_exch(sp);
88 		printk(KERN_INFO "%s: cmd %p sid %x did %x "
89 			"ox_id %x rx_id %x seq_id %x e_stat %x\n",
90 			caller, cmd, ep->sid, ep->did, ep->oxid, ep->rxid,
91 			sp->id, ep->esb_stat);
92 	}
93 	print_hex_dump(KERN_INFO, "ft_dump_cmd ", DUMP_PREFIX_NONE,
94 		16, 4, cmd->cdb, MAX_COMMAND_SIZE, 0);
95 }
96 
97 /*
98  * Get LUN from CDB.
99  */
100 static int ft_get_lun_for_cmd(struct ft_cmd *cmd, u8 *lunp)
101 {
102 	u64 lun;
103 
104 	lun = lunp[1];
105 	switch (lunp[0] >> 6) {
106 	case 0:
107 		break;
108 	case 1:
109 		lun |= (lunp[0] & 0x3f) << 8;
110 		break;
111 	default:
112 		return -1;
113 	}
114 	if (lun >= TRANSPORT_MAX_LUNS_PER_TPG)
115 		return -1;
116 	cmd->lun = lun;
117 	return transport_get_lun_for_cmd(&cmd->se_cmd, NULL, lun);
118 }
119 
120 static void ft_queue_cmd(struct ft_sess *sess, struct ft_cmd *cmd)
121 {
122 	struct se_queue_obj *qobj;
123 	unsigned long flags;
124 
125 	qobj = &sess->tport->tpg->qobj;
126 	spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
127 	list_add_tail(&cmd->se_req.qr_list, &qobj->qobj_list);
128 	spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
129 	atomic_inc(&qobj->queue_cnt);
130 	wake_up_interruptible(&qobj->thread_wq);
131 }
132 
133 static struct ft_cmd *ft_dequeue_cmd(struct se_queue_obj *qobj)
134 {
135 	unsigned long flags;
136 	struct se_queue_req *qr;
137 
138 	spin_lock_irqsave(&qobj->cmd_queue_lock, flags);
139 	if (list_empty(&qobj->qobj_list)) {
140 		spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
141 		return NULL;
142 	}
143 	qr = list_first_entry(&qobj->qobj_list, struct se_queue_req, qr_list);
144 	list_del(&qr->qr_list);
145 	atomic_dec(&qobj->queue_cnt);
146 	spin_unlock_irqrestore(&qobj->cmd_queue_lock, flags);
147 	return container_of(qr, struct ft_cmd, se_req);
148 }
149 
150 static void ft_free_cmd(struct ft_cmd *cmd)
151 {
152 	struct fc_frame *fp;
153 	struct fc_lport *lport;
154 
155 	if (!cmd)
156 		return;
157 	fp = cmd->req_frame;
158 	lport = fr_dev(fp);
159 	if (fr_seq(fp))
160 		lport->tt.seq_release(fr_seq(fp));
161 	fc_frame_free(fp);
162 	ft_sess_put(cmd->sess);	/* undo get from lookup at recv */
163 	kfree(cmd);
164 }
165 
166 void ft_release_cmd(struct se_cmd *se_cmd)
167 {
168 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
169 
170 	ft_free_cmd(cmd);
171 }
172 
173 void ft_check_stop_free(struct se_cmd *se_cmd)
174 {
175 	transport_generic_free_cmd(se_cmd, 0, 1, 0);
176 }
177 
178 /*
179  * Send response.
180  */
181 int ft_queue_status(struct se_cmd *se_cmd)
182 {
183 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
184 	struct fc_frame *fp;
185 	struct fcp_resp_with_ext *fcp;
186 	struct fc_lport *lport;
187 	struct fc_exch *ep;
188 	size_t len;
189 
190 	ft_dump_cmd(cmd, __func__);
191 	ep = fc_seq_exch(cmd->seq);
192 	lport = ep->lp;
193 	len = sizeof(*fcp) + se_cmd->scsi_sense_length;
194 	fp = fc_frame_alloc(lport, len);
195 	if (!fp) {
196 		/* XXX shouldn't just drop it - requeue and retry? */
197 		return 0;
198 	}
199 	fcp = fc_frame_payload_get(fp, len);
200 	memset(fcp, 0, len);
201 	fcp->resp.fr_status = se_cmd->scsi_status;
202 
203 	len = se_cmd->scsi_sense_length;
204 	if (len) {
205 		fcp->resp.fr_flags |= FCP_SNS_LEN_VAL;
206 		fcp->ext.fr_sns_len = htonl(len);
207 		memcpy((fcp + 1), se_cmd->sense_buffer, len);
208 	}
209 
210 	/*
211 	 * Test underflow and overflow with one mask.  Usually both are off.
212 	 * Bidirectional commands are not handled yet.
213 	 */
214 	if (se_cmd->se_cmd_flags & (SCF_OVERFLOW_BIT | SCF_UNDERFLOW_BIT)) {
215 		if (se_cmd->se_cmd_flags & SCF_OVERFLOW_BIT)
216 			fcp->resp.fr_flags |= FCP_RESID_OVER;
217 		else
218 			fcp->resp.fr_flags |= FCP_RESID_UNDER;
219 		fcp->ext.fr_resid = cpu_to_be32(se_cmd->residual_count);
220 	}
221 
222 	/*
223 	 * Send response.
224 	 */
225 	cmd->seq = lport->tt.seq_start_next(cmd->seq);
226 	fc_fill_fc_hdr(fp, FC_RCTL_DD_CMD_STATUS, ep->did, ep->sid, FC_TYPE_FCP,
227 		       FC_FC_EX_CTX | FC_FC_LAST_SEQ | FC_FC_END_SEQ, 0);
228 
229 	lport->tt.seq_send(lport, cmd->seq, fp);
230 	lport->tt.exch_done(cmd->seq);
231 	return 0;
232 }
233 
234 int ft_write_pending_status(struct se_cmd *se_cmd)
235 {
236 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
237 
238 	return cmd->write_data_len != se_cmd->data_length;
239 }
240 
241 /*
242  * Send TX_RDY (transfer ready).
243  */
244 int ft_write_pending(struct se_cmd *se_cmd)
245 {
246 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
247 	struct fc_frame *fp;
248 	struct fcp_txrdy *txrdy;
249 	struct fc_lport *lport;
250 	struct fc_exch *ep;
251 	struct fc_frame_header *fh;
252 	u32 f_ctl;
253 
254 	ft_dump_cmd(cmd, __func__);
255 
256 	ep = fc_seq_exch(cmd->seq);
257 	lport = ep->lp;
258 	fp = fc_frame_alloc(lport, sizeof(*txrdy));
259 	if (!fp)
260 		return PYX_TRANSPORT_OUT_OF_MEMORY_RESOURCES;
261 
262 	txrdy = fc_frame_payload_get(fp, sizeof(*txrdy));
263 	memset(txrdy, 0, sizeof(*txrdy));
264 	txrdy->ft_burst_len = htonl(se_cmd->data_length);
265 
266 	cmd->seq = lport->tt.seq_start_next(cmd->seq);
267 	fc_fill_fc_hdr(fp, FC_RCTL_DD_DATA_DESC, ep->did, ep->sid, FC_TYPE_FCP,
268 		       FC_FC_EX_CTX | FC_FC_END_SEQ | FC_FC_SEQ_INIT, 0);
269 
270 	fh = fc_frame_header_get(fp);
271 	f_ctl = ntoh24(fh->fh_f_ctl);
272 
273 	/* Only if it is 'Exchange Responder' */
274 	if (f_ctl & FC_FC_EX_CTX) {
275 		/* Target is 'exchange responder' and sending XFER_READY
276 		 * to 'exchange initiator (initiator)'
277 		 */
278 		if ((ep->xid <= lport->lro_xid) &&
279 		    (fh->fh_r_ctl == FC_RCTL_DD_DATA_DESC)) {
280 			if (se_cmd->se_cmd_flags & SCF_SCSI_DATA_SG_IO_CDB) {
281 				/*
282 				 * Map se_mem list to scatterlist, so that
283 				 * DDP can be setup. DDP setup function require
284 				 * scatterlist. se_mem_list is internal to
285 				 * TCM/LIO target
286 				 */
287 				transport_do_task_sg_chain(se_cmd);
288 				cmd->sg = T_TASK(se_cmd)->t_tasks_sg_chained;
289 				cmd->sg_cnt =
290 					T_TASK(se_cmd)->t_tasks_sg_chained_no;
291 			}
292 			if (cmd->sg && lport->tt.ddp_setup(lport, ep->xid,
293 						    cmd->sg, cmd->sg_cnt))
294 				cmd->was_ddp_setup = 1;
295 		}
296 	}
297 	lport->tt.seq_send(lport, cmd->seq, fp);
298 	return 0;
299 }
300 
301 u32 ft_get_task_tag(struct se_cmd *se_cmd)
302 {
303 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
304 
305 	return fc_seq_exch(cmd->seq)->rxid;
306 }
307 
308 int ft_get_cmd_state(struct se_cmd *se_cmd)
309 {
310 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
311 
312 	return cmd->state;
313 }
314 
315 int ft_is_state_remove(struct se_cmd *se_cmd)
316 {
317 	return 0;	/* XXX TBD */
318 }
319 
320 void ft_new_cmd_failure(struct se_cmd *se_cmd)
321 {
322 	/* XXX TBD */
323 	printk(KERN_INFO "%s: se_cmd %p\n", __func__, se_cmd);
324 }
325 
326 /*
327  * FC sequence response handler for follow-on sequences (data) and aborts.
328  */
329 static void ft_recv_seq(struct fc_seq *sp, struct fc_frame *fp, void *arg)
330 {
331 	struct ft_cmd *cmd = arg;
332 	struct fc_frame_header *fh;
333 
334 	if (IS_ERR(fp)) {
335 		/* XXX need to find cmd if queued */
336 		cmd->se_cmd.t_state = TRANSPORT_REMOVE;
337 		cmd->seq = NULL;
338 		transport_generic_free_cmd(&cmd->se_cmd, 0, 1, 0);
339 		return;
340 	}
341 
342 	fh = fc_frame_header_get(fp);
343 
344 	switch (fh->fh_r_ctl) {
345 	case FC_RCTL_DD_SOL_DATA:	/* write data */
346 		ft_recv_write_data(cmd, fp);
347 		break;
348 	case FC_RCTL_DD_UNSOL_CTL:	/* command */
349 	case FC_RCTL_DD_SOL_CTL:	/* transfer ready */
350 	case FC_RCTL_DD_DATA_DESC:	/* transfer ready */
351 	default:
352 		printk(KERN_INFO "%s: unhandled frame r_ctl %x\n",
353 		       __func__, fh->fh_r_ctl);
354 		fc_frame_free(fp);
355 		transport_generic_free_cmd(&cmd->se_cmd, 0, 1, 0);
356 		break;
357 	}
358 }
359 
360 /*
361  * Send a FCP response including SCSI status and optional FCP rsp_code.
362  * status is SAM_STAT_GOOD (zero) iff code is valid.
363  * This is used in error cases, such as allocation failures.
364  */
365 static void ft_send_resp_status(struct fc_lport *lport,
366 				const struct fc_frame *rx_fp,
367 				u32 status, enum fcp_resp_rsp_codes code)
368 {
369 	struct fc_frame *fp;
370 	struct fc_seq *sp;
371 	const struct fc_frame_header *fh;
372 	size_t len;
373 	struct fcp_resp_with_ext *fcp;
374 	struct fcp_resp_rsp_info *info;
375 
376 	fh = fc_frame_header_get(rx_fp);
377 	FT_IO_DBG("FCP error response: did %x oxid %x status %x code %x\n",
378 		  ntoh24(fh->fh_s_id), ntohs(fh->fh_ox_id), status, code);
379 	len = sizeof(*fcp);
380 	if (status == SAM_STAT_GOOD)
381 		len += sizeof(*info);
382 	fp = fc_frame_alloc(lport, len);
383 	if (!fp)
384 		return;
385 	fcp = fc_frame_payload_get(fp, len);
386 	memset(fcp, 0, len);
387 	fcp->resp.fr_status = status;
388 	if (status == SAM_STAT_GOOD) {
389 		fcp->ext.fr_rsp_len = htonl(sizeof(*info));
390 		fcp->resp.fr_flags |= FCP_RSP_LEN_VAL;
391 		info = (struct fcp_resp_rsp_info *)(fcp + 1);
392 		info->rsp_code = code;
393 	}
394 
395 	fc_fill_reply_hdr(fp, rx_fp, FC_RCTL_DD_CMD_STATUS, 0);
396 	sp = fr_seq(fp);
397 	if (sp)
398 		lport->tt.seq_send(lport, sp, fp);
399 	else
400 		lport->tt.frame_send(lport, fp);
401 }
402 
403 /*
404  * Send error or task management response.
405  * Always frees the cmd and associated state.
406  */
407 static void ft_send_resp_code(struct ft_cmd *cmd, enum fcp_resp_rsp_codes code)
408 {
409 	ft_send_resp_status(cmd->sess->tport->lport,
410 			    cmd->req_frame, SAM_STAT_GOOD, code);
411 	ft_free_cmd(cmd);
412 }
413 
414 /*
415  * Handle Task Management Request.
416  */
417 static void ft_send_tm(struct ft_cmd *cmd)
418 {
419 	struct se_tmr_req *tmr;
420 	struct fcp_cmnd *fcp;
421 	u8 tm_func;
422 
423 	fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
424 
425 	switch (fcp->fc_tm_flags) {
426 	case FCP_TMF_LUN_RESET:
427 		tm_func = TMR_LUN_RESET;
428 		if (ft_get_lun_for_cmd(cmd, fcp->fc_lun) < 0) {
429 			ft_dump_cmd(cmd, __func__);
430 			transport_send_check_condition_and_sense(&cmd->se_cmd,
431 				cmd->se_cmd.scsi_sense_reason, 0);
432 			ft_sess_put(cmd->sess);
433 			return;
434 		}
435 		break;
436 	case FCP_TMF_TGT_RESET:
437 		tm_func = TMR_TARGET_WARM_RESET;
438 		break;
439 	case FCP_TMF_CLR_TASK_SET:
440 		tm_func = TMR_CLEAR_TASK_SET;
441 		break;
442 	case FCP_TMF_ABT_TASK_SET:
443 		tm_func = TMR_ABORT_TASK_SET;
444 		break;
445 	case FCP_TMF_CLR_ACA:
446 		tm_func = TMR_CLEAR_ACA;
447 		break;
448 	default:
449 		/*
450 		 * FCP4r01 indicates having a combination of
451 		 * tm_flags set is invalid.
452 		 */
453 		FT_TM_DBG("invalid FCP tm_flags %x\n", fcp->fc_tm_flags);
454 		ft_send_resp_code(cmd, FCP_CMND_FIELDS_INVALID);
455 		return;
456 	}
457 
458 	FT_TM_DBG("alloc tm cmd fn %d\n", tm_func);
459 	tmr = core_tmr_alloc_req(&cmd->se_cmd, cmd, tm_func);
460 	if (!tmr) {
461 		FT_TM_DBG("alloc failed\n");
462 		ft_send_resp_code(cmd, FCP_TMF_FAILED);
463 		return;
464 	}
465 	cmd->se_cmd.se_tmr_req = tmr;
466 	transport_generic_handle_tmr(&cmd->se_cmd);
467 }
468 
469 /*
470  * Send status from completed task management request.
471  */
472 int ft_queue_tm_resp(struct se_cmd *se_cmd)
473 {
474 	struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
475 	struct se_tmr_req *tmr = se_cmd->se_tmr_req;
476 	enum fcp_resp_rsp_codes code;
477 
478 	switch (tmr->response) {
479 	case TMR_FUNCTION_COMPLETE:
480 		code = FCP_TMF_CMPL;
481 		break;
482 	case TMR_LUN_DOES_NOT_EXIST:
483 		code = FCP_TMF_INVALID_LUN;
484 		break;
485 	case TMR_FUNCTION_REJECTED:
486 		code = FCP_TMF_REJECTED;
487 		break;
488 	case TMR_TASK_DOES_NOT_EXIST:
489 	case TMR_TASK_STILL_ALLEGIANT:
490 	case TMR_TASK_FAILOVER_NOT_SUPPORTED:
491 	case TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED:
492 	case TMR_FUNCTION_AUTHORIZATION_FAILED:
493 	default:
494 		code = FCP_TMF_FAILED;
495 		break;
496 	}
497 	FT_TM_DBG("tmr fn %d resp %d fcp code %d\n",
498 		  tmr->function, tmr->response, code);
499 	ft_send_resp_code(cmd, code);
500 	return 0;
501 }
502 
503 /*
504  * Handle incoming FCP command.
505  */
506 static void ft_recv_cmd(struct ft_sess *sess, struct fc_frame *fp)
507 {
508 	struct ft_cmd *cmd;
509 	struct fc_lport *lport = sess->tport->lport;
510 
511 	cmd = kzalloc(sizeof(*cmd), GFP_ATOMIC);
512 	if (!cmd)
513 		goto busy;
514 	cmd->sess = sess;
515 	cmd->seq = lport->tt.seq_assign(lport, fp);
516 	if (!cmd->seq) {
517 		kfree(cmd);
518 		goto busy;
519 	}
520 	cmd->req_frame = fp;		/* hold frame during cmd */
521 	ft_queue_cmd(sess, cmd);
522 	return;
523 
524 busy:
525 	FT_IO_DBG("cmd or seq allocation failure - sending BUSY\n");
526 	ft_send_resp_status(lport, fp, SAM_STAT_BUSY, 0);
527 	fc_frame_free(fp);
528 	ft_sess_put(sess);		/* undo get from lookup */
529 }
530 
531 
532 /*
533  * Handle incoming FCP frame.
534  * Caller has verified that the frame is type FCP.
535  */
536 void ft_recv_req(struct ft_sess *sess, struct fc_frame *fp)
537 {
538 	struct fc_frame_header *fh = fc_frame_header_get(fp);
539 
540 	switch (fh->fh_r_ctl) {
541 	case FC_RCTL_DD_UNSOL_CMD:	/* command */
542 		ft_recv_cmd(sess, fp);
543 		break;
544 	case FC_RCTL_DD_SOL_DATA:	/* write data */
545 	case FC_RCTL_DD_UNSOL_CTL:
546 	case FC_RCTL_DD_SOL_CTL:
547 	case FC_RCTL_DD_DATA_DESC:	/* transfer ready */
548 	case FC_RCTL_ELS4_REQ:		/* SRR, perhaps */
549 	default:
550 		printk(KERN_INFO "%s: unhandled frame r_ctl %x\n",
551 		       __func__, fh->fh_r_ctl);
552 		fc_frame_free(fp);
553 		ft_sess_put(sess);	/* undo get from lookup */
554 		break;
555 	}
556 }
557 
558 /*
559  * Send new command to target.
560  */
561 static void ft_send_cmd(struct ft_cmd *cmd)
562 {
563 	struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
564 	struct se_cmd *se_cmd;
565 	struct fcp_cmnd *fcp;
566 	int data_dir;
567 	u32 data_len;
568 	int task_attr;
569 	int ret;
570 
571 	fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
572 	if (!fcp)
573 		goto err;
574 
575 	if (fcp->fc_flags & FCP_CFL_LEN_MASK)
576 		goto err;		/* not handling longer CDBs yet */
577 
578 	if (fcp->fc_tm_flags) {
579 		task_attr = FCP_PTA_SIMPLE;
580 		data_dir = DMA_NONE;
581 		data_len = 0;
582 	} else {
583 		switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
584 		case 0:
585 			data_dir = DMA_NONE;
586 			break;
587 		case FCP_CFL_RDDATA:
588 			data_dir = DMA_FROM_DEVICE;
589 			break;
590 		case FCP_CFL_WRDATA:
591 			data_dir = DMA_TO_DEVICE;
592 			break;
593 		case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
594 			goto err;	/* TBD not supported by tcm_fc yet */
595 		}
596 		/*
597 		 * Locate the SAM Task Attr from fc_pri_ta
598 		 */
599 		switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
600 		case FCP_PTA_HEADQ:
601 			task_attr = MSG_HEAD_TAG;
602 			break;
603 		case FCP_PTA_ORDERED:
604 			task_attr = MSG_ORDERED_TAG;
605 			break;
606 		case FCP_PTA_ACA:
607 			task_attr = MSG_ACA_TAG;
608 			break;
609 		case FCP_PTA_SIMPLE: /* Fallthrough */
610 		default:
611 			task_attr = MSG_SIMPLE_TAG;
612 		}
613 
614 
615 		task_attr = fcp->fc_pri_ta & FCP_PTA_MASK;
616 		data_len = ntohl(fcp->fc_dl);
617 		cmd->cdb = fcp->fc_cdb;
618 	}
619 
620 	se_cmd = &cmd->se_cmd;
621 	/*
622 	 * Initialize struct se_cmd descriptor from target_core_mod
623 	 * infrastructure
624 	 */
625 	transport_init_se_cmd(se_cmd, &ft_configfs->tf_ops, cmd->sess->se_sess,
626 			      data_len, data_dir, task_attr,
627 			      &cmd->ft_sense_buffer[0]);
628 	/*
629 	 * Check for FCP task management flags
630 	 */
631 	if (fcp->fc_tm_flags) {
632 		ft_send_tm(cmd);
633 		return;
634 	}
635 
636 	fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
637 
638 	ret = ft_get_lun_for_cmd(cmd, fcp->fc_lun);
639 	if (ret < 0) {
640 		ft_dump_cmd(cmd, __func__);
641 		transport_send_check_condition_and_sense(&cmd->se_cmd,
642 			cmd->se_cmd.scsi_sense_reason, 0);
643 		return;
644 	}
645 
646 	ret = transport_generic_allocate_tasks(se_cmd, cmd->cdb);
647 
648 	FT_IO_DBG("r_ctl %x alloc task ret %d\n", fh->fh_r_ctl, ret);
649 	ft_dump_cmd(cmd, __func__);
650 
651 	if (ret == -1) {
652 		transport_send_check_condition_and_sense(se_cmd,
653 				TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
654 		transport_generic_free_cmd(se_cmd, 0, 1, 0);
655 		return;
656 	}
657 	if (ret == -2) {
658 		if (se_cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
659 			ft_queue_status(se_cmd);
660 		else
661 			transport_send_check_condition_and_sense(se_cmd,
662 					se_cmd->scsi_sense_reason, 0);
663 		transport_generic_free_cmd(se_cmd, 0, 1, 0);
664 		return;
665 	}
666 	transport_generic_handle_cdb(se_cmd);
667 	return;
668 
669 err:
670 	ft_send_resp_code(cmd, FCP_CMND_FIELDS_INVALID);
671 	return;
672 }
673 
674 /*
675  * Handle request in the command thread.
676  */
677 static void ft_exec_req(struct ft_cmd *cmd)
678 {
679 	FT_IO_DBG("cmd state %x\n", cmd->state);
680 	switch (cmd->state) {
681 	case FC_CMD_ST_NEW:
682 		ft_send_cmd(cmd);
683 		break;
684 	default:
685 		break;
686 	}
687 }
688 
689 /*
690  * Processing thread.
691  * Currently one thread per tpg.
692  */
693 int ft_thread(void *arg)
694 {
695 	struct ft_tpg *tpg = arg;
696 	struct se_queue_obj *qobj = &tpg->qobj;
697 	struct ft_cmd *cmd;
698 	int ret;
699 
700 	set_user_nice(current, -20);
701 
702 	while (!kthread_should_stop()) {
703 		ret = wait_event_interruptible(qobj->thread_wq,
704 			atomic_read(&qobj->queue_cnt) || kthread_should_stop());
705 		if (ret < 0 || kthread_should_stop())
706 			goto out;
707 		cmd = ft_dequeue_cmd(qobj);
708 		if (cmd)
709 			ft_exec_req(cmd);
710 	}
711 
712 out:
713 	return 0;
714 }
715