1 /*******************************************************************************
2  * Filename:  target_core_transport.c
3  *
4  * This file contains the Generic Target Engine Core.
5  *
6  * (c) Copyright 2002-2012 RisingTide Systems LLC.
7  *
8  * Nicholas A. Bellinger <nab@kernel.org>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23  *
24  ******************************************************************************/
25 
26 #include <linux/net.h>
27 #include <linux/delay.h>
28 #include <linux/string.h>
29 #include <linux/timer.h>
30 #include <linux/slab.h>
31 #include <linux/blkdev.h>
32 #include <linux/spinlock.h>
33 #include <linux/kthread.h>
34 #include <linux/in.h>
35 #include <linux/cdrom.h>
36 #include <linux/module.h>
37 #include <linux/ratelimit.h>
38 #include <asm/unaligned.h>
39 #include <net/sock.h>
40 #include <net/tcp.h>
41 #include <scsi/scsi.h>
42 #include <scsi/scsi_cmnd.h>
43 #include <scsi/scsi_tcq.h>
44 
45 #include <target/target_core_base.h>
46 #include <target/target_core_backend.h>
47 #include <target/target_core_fabric.h>
48 #include <target/target_core_configfs.h>
49 
50 #include "target_core_internal.h"
51 #include "target_core_alua.h"
52 #include "target_core_pr.h"
53 #include "target_core_ua.h"
54 
55 #define CREATE_TRACE_POINTS
56 #include <trace/events/target.h>
57 
58 static struct workqueue_struct *target_completion_wq;
59 static struct kmem_cache *se_sess_cache;
60 struct kmem_cache *se_ua_cache;
61 struct kmem_cache *t10_pr_reg_cache;
62 struct kmem_cache *t10_alua_lu_gp_cache;
63 struct kmem_cache *t10_alua_lu_gp_mem_cache;
64 struct kmem_cache *t10_alua_tg_pt_gp_cache;
65 struct kmem_cache *t10_alua_tg_pt_gp_mem_cache;
66 
67 static void transport_complete_task_attr(struct se_cmd *cmd);
68 static void transport_handle_queue_full(struct se_cmd *cmd,
69 		struct se_device *dev);
70 static int transport_generic_get_mem(struct se_cmd *cmd);
71 static int transport_put_cmd(struct se_cmd *cmd);
72 static void target_complete_ok_work(struct work_struct *work);
73 
74 int init_se_kmem_caches(void)
75 {
76 	se_sess_cache = kmem_cache_create("se_sess_cache",
77 			sizeof(struct se_session), __alignof__(struct se_session),
78 			0, NULL);
79 	if (!se_sess_cache) {
80 		pr_err("kmem_cache_create() for struct se_session"
81 				" failed\n");
82 		goto out;
83 	}
84 	se_ua_cache = kmem_cache_create("se_ua_cache",
85 			sizeof(struct se_ua), __alignof__(struct se_ua),
86 			0, NULL);
87 	if (!se_ua_cache) {
88 		pr_err("kmem_cache_create() for struct se_ua failed\n");
89 		goto out_free_sess_cache;
90 	}
91 	t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
92 			sizeof(struct t10_pr_registration),
93 			__alignof__(struct t10_pr_registration), 0, NULL);
94 	if (!t10_pr_reg_cache) {
95 		pr_err("kmem_cache_create() for struct t10_pr_registration"
96 				" failed\n");
97 		goto out_free_ua_cache;
98 	}
99 	t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
100 			sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
101 			0, NULL);
102 	if (!t10_alua_lu_gp_cache) {
103 		pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
104 				" failed\n");
105 		goto out_free_pr_reg_cache;
106 	}
107 	t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
108 			sizeof(struct t10_alua_lu_gp_member),
109 			__alignof__(struct t10_alua_lu_gp_member), 0, NULL);
110 	if (!t10_alua_lu_gp_mem_cache) {
111 		pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
112 				"cache failed\n");
113 		goto out_free_lu_gp_cache;
114 	}
115 	t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
116 			sizeof(struct t10_alua_tg_pt_gp),
117 			__alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
118 	if (!t10_alua_tg_pt_gp_cache) {
119 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
120 				"cache failed\n");
121 		goto out_free_lu_gp_mem_cache;
122 	}
123 	t10_alua_tg_pt_gp_mem_cache = kmem_cache_create(
124 			"t10_alua_tg_pt_gp_mem_cache",
125 			sizeof(struct t10_alua_tg_pt_gp_member),
126 			__alignof__(struct t10_alua_tg_pt_gp_member),
127 			0, NULL);
128 	if (!t10_alua_tg_pt_gp_mem_cache) {
129 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
130 				"mem_t failed\n");
131 		goto out_free_tg_pt_gp_cache;
132 	}
133 
134 	target_completion_wq = alloc_workqueue("target_completion",
135 					       WQ_MEM_RECLAIM, 0);
136 	if (!target_completion_wq)
137 		goto out_free_tg_pt_gp_mem_cache;
138 
139 	return 0;
140 
141 out_free_tg_pt_gp_mem_cache:
142 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
143 out_free_tg_pt_gp_cache:
144 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
145 out_free_lu_gp_mem_cache:
146 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
147 out_free_lu_gp_cache:
148 	kmem_cache_destroy(t10_alua_lu_gp_cache);
149 out_free_pr_reg_cache:
150 	kmem_cache_destroy(t10_pr_reg_cache);
151 out_free_ua_cache:
152 	kmem_cache_destroy(se_ua_cache);
153 out_free_sess_cache:
154 	kmem_cache_destroy(se_sess_cache);
155 out:
156 	return -ENOMEM;
157 }
158 
159 void release_se_kmem_caches(void)
160 {
161 	destroy_workqueue(target_completion_wq);
162 	kmem_cache_destroy(se_sess_cache);
163 	kmem_cache_destroy(se_ua_cache);
164 	kmem_cache_destroy(t10_pr_reg_cache);
165 	kmem_cache_destroy(t10_alua_lu_gp_cache);
166 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
167 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
168 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
169 }
170 
171 /* This code ensures unique mib indexes are handed out. */
172 static DEFINE_SPINLOCK(scsi_mib_index_lock);
173 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
174 
175 /*
176  * Allocate a new row index for the entry type specified
177  */
178 u32 scsi_get_new_index(scsi_index_t type)
179 {
180 	u32 new_index;
181 
182 	BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
183 
184 	spin_lock(&scsi_mib_index_lock);
185 	new_index = ++scsi_mib_index[type];
186 	spin_unlock(&scsi_mib_index_lock);
187 
188 	return new_index;
189 }
190 
191 void transport_subsystem_check_init(void)
192 {
193 	int ret;
194 	static int sub_api_initialized;
195 
196 	if (sub_api_initialized)
197 		return;
198 
199 	ret = request_module("target_core_iblock");
200 	if (ret != 0)
201 		pr_err("Unable to load target_core_iblock\n");
202 
203 	ret = request_module("target_core_file");
204 	if (ret != 0)
205 		pr_err("Unable to load target_core_file\n");
206 
207 	ret = request_module("target_core_pscsi");
208 	if (ret != 0)
209 		pr_err("Unable to load target_core_pscsi\n");
210 
211 	sub_api_initialized = 1;
212 }
213 
214 struct se_session *transport_init_session(void)
215 {
216 	struct se_session *se_sess;
217 
218 	se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
219 	if (!se_sess) {
220 		pr_err("Unable to allocate struct se_session from"
221 				" se_sess_cache\n");
222 		return ERR_PTR(-ENOMEM);
223 	}
224 	INIT_LIST_HEAD(&se_sess->sess_list);
225 	INIT_LIST_HEAD(&se_sess->sess_acl_list);
226 	INIT_LIST_HEAD(&se_sess->sess_cmd_list);
227 	INIT_LIST_HEAD(&se_sess->sess_wait_list);
228 	spin_lock_init(&se_sess->sess_cmd_lock);
229 	kref_init(&se_sess->sess_kref);
230 
231 	return se_sess;
232 }
233 EXPORT_SYMBOL(transport_init_session);
234 
235 /*
236  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
237  */
238 void __transport_register_session(
239 	struct se_portal_group *se_tpg,
240 	struct se_node_acl *se_nacl,
241 	struct se_session *se_sess,
242 	void *fabric_sess_ptr)
243 {
244 	unsigned char buf[PR_REG_ISID_LEN];
245 
246 	se_sess->se_tpg = se_tpg;
247 	se_sess->fabric_sess_ptr = fabric_sess_ptr;
248 	/*
249 	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
250 	 *
251 	 * Only set for struct se_session's that will actually be moving I/O.
252 	 * eg: *NOT* discovery sessions.
253 	 */
254 	if (se_nacl) {
255 		/*
256 		 * If the fabric module supports an ISID based TransportID,
257 		 * save this value in binary from the fabric I_T Nexus now.
258 		 */
259 		if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
260 			memset(&buf[0], 0, PR_REG_ISID_LEN);
261 			se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
262 					&buf[0], PR_REG_ISID_LEN);
263 			se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
264 		}
265 		kref_get(&se_nacl->acl_kref);
266 
267 		spin_lock_irq(&se_nacl->nacl_sess_lock);
268 		/*
269 		 * The se_nacl->nacl_sess pointer will be set to the
270 		 * last active I_T Nexus for each struct se_node_acl.
271 		 */
272 		se_nacl->nacl_sess = se_sess;
273 
274 		list_add_tail(&se_sess->sess_acl_list,
275 			      &se_nacl->acl_sess_list);
276 		spin_unlock_irq(&se_nacl->nacl_sess_lock);
277 	}
278 	list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
279 
280 	pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
281 		se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
282 }
283 EXPORT_SYMBOL(__transport_register_session);
284 
285 void transport_register_session(
286 	struct se_portal_group *se_tpg,
287 	struct se_node_acl *se_nacl,
288 	struct se_session *se_sess,
289 	void *fabric_sess_ptr)
290 {
291 	unsigned long flags;
292 
293 	spin_lock_irqsave(&se_tpg->session_lock, flags);
294 	__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
295 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
296 }
297 EXPORT_SYMBOL(transport_register_session);
298 
299 static void target_release_session(struct kref *kref)
300 {
301 	struct se_session *se_sess = container_of(kref,
302 			struct se_session, sess_kref);
303 	struct se_portal_group *se_tpg = se_sess->se_tpg;
304 
305 	se_tpg->se_tpg_tfo->close_session(se_sess);
306 }
307 
308 void target_get_session(struct se_session *se_sess)
309 {
310 	kref_get(&se_sess->sess_kref);
311 }
312 EXPORT_SYMBOL(target_get_session);
313 
314 void target_put_session(struct se_session *se_sess)
315 {
316 	struct se_portal_group *tpg = se_sess->se_tpg;
317 
318 	if (tpg->se_tpg_tfo->put_session != NULL) {
319 		tpg->se_tpg_tfo->put_session(se_sess);
320 		return;
321 	}
322 	kref_put(&se_sess->sess_kref, target_release_session);
323 }
324 EXPORT_SYMBOL(target_put_session);
325 
326 static void target_complete_nacl(struct kref *kref)
327 {
328 	struct se_node_acl *nacl = container_of(kref,
329 				struct se_node_acl, acl_kref);
330 
331 	complete(&nacl->acl_free_comp);
332 }
333 
334 void target_put_nacl(struct se_node_acl *nacl)
335 {
336 	kref_put(&nacl->acl_kref, target_complete_nacl);
337 }
338 
339 void transport_deregister_session_configfs(struct se_session *se_sess)
340 {
341 	struct se_node_acl *se_nacl;
342 	unsigned long flags;
343 	/*
344 	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
345 	 */
346 	se_nacl = se_sess->se_node_acl;
347 	if (se_nacl) {
348 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
349 		if (se_nacl->acl_stop == 0)
350 			list_del(&se_sess->sess_acl_list);
351 		/*
352 		 * If the session list is empty, then clear the pointer.
353 		 * Otherwise, set the struct se_session pointer from the tail
354 		 * element of the per struct se_node_acl active session list.
355 		 */
356 		if (list_empty(&se_nacl->acl_sess_list))
357 			se_nacl->nacl_sess = NULL;
358 		else {
359 			se_nacl->nacl_sess = container_of(
360 					se_nacl->acl_sess_list.prev,
361 					struct se_session, sess_acl_list);
362 		}
363 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
364 	}
365 }
366 EXPORT_SYMBOL(transport_deregister_session_configfs);
367 
368 void transport_free_session(struct se_session *se_sess)
369 {
370 	kmem_cache_free(se_sess_cache, se_sess);
371 }
372 EXPORT_SYMBOL(transport_free_session);
373 
374 void transport_deregister_session(struct se_session *se_sess)
375 {
376 	struct se_portal_group *se_tpg = se_sess->se_tpg;
377 	struct target_core_fabric_ops *se_tfo;
378 	struct se_node_acl *se_nacl;
379 	unsigned long flags;
380 	bool comp_nacl = true;
381 
382 	if (!se_tpg) {
383 		transport_free_session(se_sess);
384 		return;
385 	}
386 	se_tfo = se_tpg->se_tpg_tfo;
387 
388 	spin_lock_irqsave(&se_tpg->session_lock, flags);
389 	list_del(&se_sess->sess_list);
390 	se_sess->se_tpg = NULL;
391 	se_sess->fabric_sess_ptr = NULL;
392 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
393 
394 	/*
395 	 * Determine if we need to do extra work for this initiator node's
396 	 * struct se_node_acl if it had been previously dynamically generated.
397 	 */
398 	se_nacl = se_sess->se_node_acl;
399 
400 	spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
401 	if (se_nacl && se_nacl->dynamic_node_acl) {
402 		if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
403 			list_del(&se_nacl->acl_list);
404 			se_tpg->num_node_acls--;
405 			spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
406 			core_tpg_wait_for_nacl_pr_ref(se_nacl);
407 			core_free_device_list_for_node(se_nacl, se_tpg);
408 			se_tfo->tpg_release_fabric_acl(se_tpg, se_nacl);
409 
410 			comp_nacl = false;
411 			spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
412 		}
413 	}
414 	spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
415 
416 	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
417 		se_tpg->se_tpg_tfo->get_fabric_name());
418 	/*
419 	 * If last kref is dropping now for an explict NodeACL, awake sleeping
420 	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
421 	 * removal context.
422 	 */
423 	if (se_nacl && comp_nacl == true)
424 		target_put_nacl(se_nacl);
425 
426 	transport_free_session(se_sess);
427 }
428 EXPORT_SYMBOL(transport_deregister_session);
429 
430 /*
431  * Called with cmd->t_state_lock held.
432  */
433 static void target_remove_from_state_list(struct se_cmd *cmd)
434 {
435 	struct se_device *dev = cmd->se_dev;
436 	unsigned long flags;
437 
438 	if (!dev)
439 		return;
440 
441 	if (cmd->transport_state & CMD_T_BUSY)
442 		return;
443 
444 	spin_lock_irqsave(&dev->execute_task_lock, flags);
445 	if (cmd->state_active) {
446 		list_del(&cmd->state_list);
447 		cmd->state_active = false;
448 	}
449 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
450 }
451 
452 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
453 				    bool write_pending)
454 {
455 	unsigned long flags;
456 
457 	spin_lock_irqsave(&cmd->t_state_lock, flags);
458 	if (write_pending)
459 		cmd->t_state = TRANSPORT_WRITE_PENDING;
460 
461 	/*
462 	 * Determine if IOCTL context caller in requesting the stopping of this
463 	 * command for LUN shutdown purposes.
464 	 */
465 	if (cmd->transport_state & CMD_T_LUN_STOP) {
466 		pr_debug("%s:%d CMD_T_LUN_STOP for ITT: 0x%08x\n",
467 			__func__, __LINE__, cmd->se_tfo->get_task_tag(cmd));
468 
469 		cmd->transport_state &= ~CMD_T_ACTIVE;
470 		if (remove_from_lists)
471 			target_remove_from_state_list(cmd);
472 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
473 
474 		complete(&cmd->transport_lun_stop_comp);
475 		return 1;
476 	}
477 
478 	if (remove_from_lists) {
479 		target_remove_from_state_list(cmd);
480 
481 		/*
482 		 * Clear struct se_cmd->se_lun before the handoff to FE.
483 		 */
484 		cmd->se_lun = NULL;
485 	}
486 
487 	/*
488 	 * Determine if frontend context caller is requesting the stopping of
489 	 * this command for frontend exceptions.
490 	 */
491 	if (cmd->transport_state & CMD_T_STOP) {
492 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
493 			__func__, __LINE__,
494 			cmd->se_tfo->get_task_tag(cmd));
495 
496 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
497 
498 		complete(&cmd->t_transport_stop_comp);
499 		return 1;
500 	}
501 
502 	cmd->transport_state &= ~CMD_T_ACTIVE;
503 	if (remove_from_lists) {
504 		/*
505 		 * Some fabric modules like tcm_loop can release
506 		 * their internally allocated I/O reference now and
507 		 * struct se_cmd now.
508 		 *
509 		 * Fabric modules are expected to return '1' here if the
510 		 * se_cmd being passed is released at this point,
511 		 * or zero if not being released.
512 		 */
513 		if (cmd->se_tfo->check_stop_free != NULL) {
514 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
515 			return cmd->se_tfo->check_stop_free(cmd);
516 		}
517 	}
518 
519 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
520 	return 0;
521 }
522 
523 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
524 {
525 	return transport_cmd_check_stop(cmd, true, false);
526 }
527 
528 static void transport_lun_remove_cmd(struct se_cmd *cmd)
529 {
530 	struct se_lun *lun = cmd->se_lun;
531 	unsigned long flags;
532 
533 	if (!lun)
534 		return;
535 
536 	spin_lock_irqsave(&lun->lun_cmd_lock, flags);
537 	if (!list_empty(&cmd->se_lun_node))
538 		list_del_init(&cmd->se_lun_node);
539 	spin_unlock_irqrestore(&lun->lun_cmd_lock, flags);
540 }
541 
542 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
543 {
544 	if (transport_cmd_check_stop_to_fabric(cmd))
545 		return;
546 	if (remove)
547 		transport_put_cmd(cmd);
548 }
549 
550 static void target_complete_failure_work(struct work_struct *work)
551 {
552 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
553 
554 	transport_generic_request_failure(cmd,
555 			TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
556 }
557 
558 /*
559  * Used when asking transport to copy Sense Data from the underlying
560  * Linux/SCSI struct scsi_cmnd
561  */
562 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
563 {
564 	struct se_device *dev = cmd->se_dev;
565 
566 	WARN_ON(!cmd->se_lun);
567 
568 	if (!dev)
569 		return NULL;
570 
571 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
572 		return NULL;
573 
574 	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
575 
576 	pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
577 		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
578 	return cmd->sense_buffer;
579 }
580 
581 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
582 {
583 	struct se_device *dev = cmd->se_dev;
584 	int success = scsi_status == GOOD;
585 	unsigned long flags;
586 
587 	cmd->scsi_status = scsi_status;
588 
589 
590 	spin_lock_irqsave(&cmd->t_state_lock, flags);
591 	cmd->transport_state &= ~CMD_T_BUSY;
592 
593 	if (dev && dev->transport->transport_complete) {
594 		dev->transport->transport_complete(cmd,
595 				cmd->t_data_sg,
596 				transport_get_sense_buffer(cmd));
597 		if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
598 			success = 1;
599 	}
600 
601 	/*
602 	 * See if we are waiting to complete for an exception condition.
603 	 */
604 	if (cmd->transport_state & CMD_T_REQUEST_STOP) {
605 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
606 		complete(&cmd->task_stop_comp);
607 		return;
608 	}
609 
610 	if (!success)
611 		cmd->transport_state |= CMD_T_FAILED;
612 
613 	/*
614 	 * Check for case where an explict ABORT_TASK has been received
615 	 * and transport_wait_for_tasks() will be waiting for completion..
616 	 */
617 	if (cmd->transport_state & CMD_T_ABORTED &&
618 	    cmd->transport_state & CMD_T_STOP) {
619 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
620 		complete(&cmd->t_transport_stop_comp);
621 		return;
622 	} else if (cmd->transport_state & CMD_T_FAILED) {
623 		INIT_WORK(&cmd->work, target_complete_failure_work);
624 	} else {
625 		INIT_WORK(&cmd->work, target_complete_ok_work);
626 	}
627 
628 	cmd->t_state = TRANSPORT_COMPLETE;
629 	cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
630 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
631 
632 	queue_work(target_completion_wq, &cmd->work);
633 }
634 EXPORT_SYMBOL(target_complete_cmd);
635 
636 static void target_add_to_state_list(struct se_cmd *cmd)
637 {
638 	struct se_device *dev = cmd->se_dev;
639 	unsigned long flags;
640 
641 	spin_lock_irqsave(&dev->execute_task_lock, flags);
642 	if (!cmd->state_active) {
643 		list_add_tail(&cmd->state_list, &dev->state_list);
644 		cmd->state_active = true;
645 	}
646 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
647 }
648 
649 /*
650  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
651  */
652 static void transport_write_pending_qf(struct se_cmd *cmd);
653 static void transport_complete_qf(struct se_cmd *cmd);
654 
655 void target_qf_do_work(struct work_struct *work)
656 {
657 	struct se_device *dev = container_of(work, struct se_device,
658 					qf_work_queue);
659 	LIST_HEAD(qf_cmd_list);
660 	struct se_cmd *cmd, *cmd_tmp;
661 
662 	spin_lock_irq(&dev->qf_cmd_lock);
663 	list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
664 	spin_unlock_irq(&dev->qf_cmd_lock);
665 
666 	list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
667 		list_del(&cmd->se_qf_node);
668 		atomic_dec(&dev->dev_qf_count);
669 		smp_mb__after_atomic_dec();
670 
671 		pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
672 			" context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
673 			(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
674 			(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
675 			: "UNKNOWN");
676 
677 		if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
678 			transport_write_pending_qf(cmd);
679 		else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
680 			transport_complete_qf(cmd);
681 	}
682 }
683 
684 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
685 {
686 	switch (cmd->data_direction) {
687 	case DMA_NONE:
688 		return "NONE";
689 	case DMA_FROM_DEVICE:
690 		return "READ";
691 	case DMA_TO_DEVICE:
692 		return "WRITE";
693 	case DMA_BIDIRECTIONAL:
694 		return "BIDI";
695 	default:
696 		break;
697 	}
698 
699 	return "UNKNOWN";
700 }
701 
702 void transport_dump_dev_state(
703 	struct se_device *dev,
704 	char *b,
705 	int *bl)
706 {
707 	*bl += sprintf(b + *bl, "Status: ");
708 	if (dev->export_count)
709 		*bl += sprintf(b + *bl, "ACTIVATED");
710 	else
711 		*bl += sprintf(b + *bl, "DEACTIVATED");
712 
713 	*bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
714 	*bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
715 		dev->dev_attrib.block_size,
716 		dev->dev_attrib.hw_max_sectors);
717 	*bl += sprintf(b + *bl, "        ");
718 }
719 
720 void transport_dump_vpd_proto_id(
721 	struct t10_vpd *vpd,
722 	unsigned char *p_buf,
723 	int p_buf_len)
724 {
725 	unsigned char buf[VPD_TMP_BUF_SIZE];
726 	int len;
727 
728 	memset(buf, 0, VPD_TMP_BUF_SIZE);
729 	len = sprintf(buf, "T10 VPD Protocol Identifier: ");
730 
731 	switch (vpd->protocol_identifier) {
732 	case 0x00:
733 		sprintf(buf+len, "Fibre Channel\n");
734 		break;
735 	case 0x10:
736 		sprintf(buf+len, "Parallel SCSI\n");
737 		break;
738 	case 0x20:
739 		sprintf(buf+len, "SSA\n");
740 		break;
741 	case 0x30:
742 		sprintf(buf+len, "IEEE 1394\n");
743 		break;
744 	case 0x40:
745 		sprintf(buf+len, "SCSI Remote Direct Memory Access"
746 				" Protocol\n");
747 		break;
748 	case 0x50:
749 		sprintf(buf+len, "Internet SCSI (iSCSI)\n");
750 		break;
751 	case 0x60:
752 		sprintf(buf+len, "SAS Serial SCSI Protocol\n");
753 		break;
754 	case 0x70:
755 		sprintf(buf+len, "Automation/Drive Interface Transport"
756 				" Protocol\n");
757 		break;
758 	case 0x80:
759 		sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
760 		break;
761 	default:
762 		sprintf(buf+len, "Unknown 0x%02x\n",
763 				vpd->protocol_identifier);
764 		break;
765 	}
766 
767 	if (p_buf)
768 		strncpy(p_buf, buf, p_buf_len);
769 	else
770 		pr_debug("%s", buf);
771 }
772 
773 void
774 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
775 {
776 	/*
777 	 * Check if the Protocol Identifier Valid (PIV) bit is set..
778 	 *
779 	 * from spc3r23.pdf section 7.5.1
780 	 */
781 	 if (page_83[1] & 0x80) {
782 		vpd->protocol_identifier = (page_83[0] & 0xf0);
783 		vpd->protocol_identifier_set = 1;
784 		transport_dump_vpd_proto_id(vpd, NULL, 0);
785 	}
786 }
787 EXPORT_SYMBOL(transport_set_vpd_proto_id);
788 
789 int transport_dump_vpd_assoc(
790 	struct t10_vpd *vpd,
791 	unsigned char *p_buf,
792 	int p_buf_len)
793 {
794 	unsigned char buf[VPD_TMP_BUF_SIZE];
795 	int ret = 0;
796 	int len;
797 
798 	memset(buf, 0, VPD_TMP_BUF_SIZE);
799 	len = sprintf(buf, "T10 VPD Identifier Association: ");
800 
801 	switch (vpd->association) {
802 	case 0x00:
803 		sprintf(buf+len, "addressed logical unit\n");
804 		break;
805 	case 0x10:
806 		sprintf(buf+len, "target port\n");
807 		break;
808 	case 0x20:
809 		sprintf(buf+len, "SCSI target device\n");
810 		break;
811 	default:
812 		sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
813 		ret = -EINVAL;
814 		break;
815 	}
816 
817 	if (p_buf)
818 		strncpy(p_buf, buf, p_buf_len);
819 	else
820 		pr_debug("%s", buf);
821 
822 	return ret;
823 }
824 
825 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
826 {
827 	/*
828 	 * The VPD identification association..
829 	 *
830 	 * from spc3r23.pdf Section 7.6.3.1 Table 297
831 	 */
832 	vpd->association = (page_83[1] & 0x30);
833 	return transport_dump_vpd_assoc(vpd, NULL, 0);
834 }
835 EXPORT_SYMBOL(transport_set_vpd_assoc);
836 
837 int transport_dump_vpd_ident_type(
838 	struct t10_vpd *vpd,
839 	unsigned char *p_buf,
840 	int p_buf_len)
841 {
842 	unsigned char buf[VPD_TMP_BUF_SIZE];
843 	int ret = 0;
844 	int len;
845 
846 	memset(buf, 0, VPD_TMP_BUF_SIZE);
847 	len = sprintf(buf, "T10 VPD Identifier Type: ");
848 
849 	switch (vpd->device_identifier_type) {
850 	case 0x00:
851 		sprintf(buf+len, "Vendor specific\n");
852 		break;
853 	case 0x01:
854 		sprintf(buf+len, "T10 Vendor ID based\n");
855 		break;
856 	case 0x02:
857 		sprintf(buf+len, "EUI-64 based\n");
858 		break;
859 	case 0x03:
860 		sprintf(buf+len, "NAA\n");
861 		break;
862 	case 0x04:
863 		sprintf(buf+len, "Relative target port identifier\n");
864 		break;
865 	case 0x08:
866 		sprintf(buf+len, "SCSI name string\n");
867 		break;
868 	default:
869 		sprintf(buf+len, "Unsupported: 0x%02x\n",
870 				vpd->device_identifier_type);
871 		ret = -EINVAL;
872 		break;
873 	}
874 
875 	if (p_buf) {
876 		if (p_buf_len < strlen(buf)+1)
877 			return -EINVAL;
878 		strncpy(p_buf, buf, p_buf_len);
879 	} else {
880 		pr_debug("%s", buf);
881 	}
882 
883 	return ret;
884 }
885 
886 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
887 {
888 	/*
889 	 * The VPD identifier type..
890 	 *
891 	 * from spc3r23.pdf Section 7.6.3.1 Table 298
892 	 */
893 	vpd->device_identifier_type = (page_83[1] & 0x0f);
894 	return transport_dump_vpd_ident_type(vpd, NULL, 0);
895 }
896 EXPORT_SYMBOL(transport_set_vpd_ident_type);
897 
898 int transport_dump_vpd_ident(
899 	struct t10_vpd *vpd,
900 	unsigned char *p_buf,
901 	int p_buf_len)
902 {
903 	unsigned char buf[VPD_TMP_BUF_SIZE];
904 	int ret = 0;
905 
906 	memset(buf, 0, VPD_TMP_BUF_SIZE);
907 
908 	switch (vpd->device_identifier_code_set) {
909 	case 0x01: /* Binary */
910 		snprintf(buf, sizeof(buf),
911 			"T10 VPD Binary Device Identifier: %s\n",
912 			&vpd->device_identifier[0]);
913 		break;
914 	case 0x02: /* ASCII */
915 		snprintf(buf, sizeof(buf),
916 			"T10 VPD ASCII Device Identifier: %s\n",
917 			&vpd->device_identifier[0]);
918 		break;
919 	case 0x03: /* UTF-8 */
920 		snprintf(buf, sizeof(buf),
921 			"T10 VPD UTF-8 Device Identifier: %s\n",
922 			&vpd->device_identifier[0]);
923 		break;
924 	default:
925 		sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
926 			" 0x%02x", vpd->device_identifier_code_set);
927 		ret = -EINVAL;
928 		break;
929 	}
930 
931 	if (p_buf)
932 		strncpy(p_buf, buf, p_buf_len);
933 	else
934 		pr_debug("%s", buf);
935 
936 	return ret;
937 }
938 
939 int
940 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
941 {
942 	static const char hex_str[] = "0123456789abcdef";
943 	int j = 0, i = 4; /* offset to start of the identifier */
944 
945 	/*
946 	 * The VPD Code Set (encoding)
947 	 *
948 	 * from spc3r23.pdf Section 7.6.3.1 Table 296
949 	 */
950 	vpd->device_identifier_code_set = (page_83[0] & 0x0f);
951 	switch (vpd->device_identifier_code_set) {
952 	case 0x01: /* Binary */
953 		vpd->device_identifier[j++] =
954 				hex_str[vpd->device_identifier_type];
955 		while (i < (4 + page_83[3])) {
956 			vpd->device_identifier[j++] =
957 				hex_str[(page_83[i] & 0xf0) >> 4];
958 			vpd->device_identifier[j++] =
959 				hex_str[page_83[i] & 0x0f];
960 			i++;
961 		}
962 		break;
963 	case 0x02: /* ASCII */
964 	case 0x03: /* UTF-8 */
965 		while (i < (4 + page_83[3]))
966 			vpd->device_identifier[j++] = page_83[i++];
967 		break;
968 	default:
969 		break;
970 	}
971 
972 	return transport_dump_vpd_ident(vpd, NULL, 0);
973 }
974 EXPORT_SYMBOL(transport_set_vpd_ident);
975 
976 sense_reason_t
977 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
978 {
979 	struct se_device *dev = cmd->se_dev;
980 
981 	if (cmd->unknown_data_length) {
982 		cmd->data_length = size;
983 	} else if (size != cmd->data_length) {
984 		pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
985 			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
986 			" 0x%02x\n", cmd->se_tfo->get_fabric_name(),
987 				cmd->data_length, size, cmd->t_task_cdb[0]);
988 
989 		if (cmd->data_direction == DMA_TO_DEVICE) {
990 			pr_err("Rejecting underflow/overflow"
991 					" WRITE data\n");
992 			return TCM_INVALID_CDB_FIELD;
993 		}
994 		/*
995 		 * Reject READ_* or WRITE_* with overflow/underflow for
996 		 * type SCF_SCSI_DATA_CDB.
997 		 */
998 		if (dev->dev_attrib.block_size != 512)  {
999 			pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1000 				" CDB on non 512-byte sector setup subsystem"
1001 				" plugin: %s\n", dev->transport->name);
1002 			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1003 			return TCM_INVALID_CDB_FIELD;
1004 		}
1005 		/*
1006 		 * For the overflow case keep the existing fabric provided
1007 		 * ->data_length.  Otherwise for the underflow case, reset
1008 		 * ->data_length to the smaller SCSI expected data transfer
1009 		 * length.
1010 		 */
1011 		if (size > cmd->data_length) {
1012 			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1013 			cmd->residual_count = (size - cmd->data_length);
1014 		} else {
1015 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1016 			cmd->residual_count = (cmd->data_length - size);
1017 			cmd->data_length = size;
1018 		}
1019 	}
1020 
1021 	return 0;
1022 
1023 }
1024 
1025 /*
1026  * Used by fabric modules containing a local struct se_cmd within their
1027  * fabric dependent per I/O descriptor.
1028  */
1029 void transport_init_se_cmd(
1030 	struct se_cmd *cmd,
1031 	struct target_core_fabric_ops *tfo,
1032 	struct se_session *se_sess,
1033 	u32 data_length,
1034 	int data_direction,
1035 	int task_attr,
1036 	unsigned char *sense_buffer)
1037 {
1038 	INIT_LIST_HEAD(&cmd->se_lun_node);
1039 	INIT_LIST_HEAD(&cmd->se_delayed_node);
1040 	INIT_LIST_HEAD(&cmd->se_qf_node);
1041 	INIT_LIST_HEAD(&cmd->se_cmd_list);
1042 	INIT_LIST_HEAD(&cmd->state_list);
1043 	init_completion(&cmd->transport_lun_fe_stop_comp);
1044 	init_completion(&cmd->transport_lun_stop_comp);
1045 	init_completion(&cmd->t_transport_stop_comp);
1046 	init_completion(&cmd->cmd_wait_comp);
1047 	init_completion(&cmd->task_stop_comp);
1048 	spin_lock_init(&cmd->t_state_lock);
1049 	cmd->transport_state = CMD_T_DEV_ACTIVE;
1050 
1051 	cmd->se_tfo = tfo;
1052 	cmd->se_sess = se_sess;
1053 	cmd->data_length = data_length;
1054 	cmd->data_direction = data_direction;
1055 	cmd->sam_task_attr = task_attr;
1056 	cmd->sense_buffer = sense_buffer;
1057 
1058 	cmd->state_active = false;
1059 }
1060 EXPORT_SYMBOL(transport_init_se_cmd);
1061 
1062 static sense_reason_t
1063 transport_check_alloc_task_attr(struct se_cmd *cmd)
1064 {
1065 	struct se_device *dev = cmd->se_dev;
1066 
1067 	/*
1068 	 * Check if SAM Task Attribute emulation is enabled for this
1069 	 * struct se_device storage object
1070 	 */
1071 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1072 		return 0;
1073 
1074 	if (cmd->sam_task_attr == MSG_ACA_TAG) {
1075 		pr_debug("SAM Task Attribute ACA"
1076 			" emulation is not supported\n");
1077 		return TCM_INVALID_CDB_FIELD;
1078 	}
1079 	/*
1080 	 * Used to determine when ORDERED commands should go from
1081 	 * Dormant to Active status.
1082 	 */
1083 	cmd->se_ordered_id = atomic_inc_return(&dev->dev_ordered_id);
1084 	smp_mb__after_atomic_inc();
1085 	pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
1086 			cmd->se_ordered_id, cmd->sam_task_attr,
1087 			dev->transport->name);
1088 	return 0;
1089 }
1090 
1091 sense_reason_t
1092 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1093 {
1094 	struct se_device *dev = cmd->se_dev;
1095 	sense_reason_t ret;
1096 
1097 	/*
1098 	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1099 	 * for VARIABLE_LENGTH_CMD
1100 	 */
1101 	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1102 		pr_err("Received SCSI CDB with command_size: %d that"
1103 			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1104 			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1105 		return TCM_INVALID_CDB_FIELD;
1106 	}
1107 	/*
1108 	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1109 	 * allocate the additional extended CDB buffer now..  Otherwise
1110 	 * setup the pointer from __t_task_cdb to t_task_cdb.
1111 	 */
1112 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1113 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1114 						GFP_KERNEL);
1115 		if (!cmd->t_task_cdb) {
1116 			pr_err("Unable to allocate cmd->t_task_cdb"
1117 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1118 				scsi_command_size(cdb),
1119 				(unsigned long)sizeof(cmd->__t_task_cdb));
1120 			return TCM_OUT_OF_RESOURCES;
1121 		}
1122 	} else
1123 		cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1124 	/*
1125 	 * Copy the original CDB into cmd->
1126 	 */
1127 	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1128 
1129 	trace_target_sequencer_start(cmd);
1130 
1131 	/*
1132 	 * Check for an existing UNIT ATTENTION condition
1133 	 */
1134 	ret = target_scsi3_ua_check(cmd);
1135 	if (ret)
1136 		return ret;
1137 
1138 	ret = target_alua_state_check(cmd);
1139 	if (ret)
1140 		return ret;
1141 
1142 	ret = target_check_reservation(cmd);
1143 	if (ret) {
1144 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1145 		return ret;
1146 	}
1147 
1148 	ret = dev->transport->parse_cdb(cmd);
1149 	if (ret)
1150 		return ret;
1151 
1152 	ret = transport_check_alloc_task_attr(cmd);
1153 	if (ret)
1154 		return ret;
1155 
1156 	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1157 
1158 	spin_lock(&cmd->se_lun->lun_sep_lock);
1159 	if (cmd->se_lun->lun_sep)
1160 		cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
1161 	spin_unlock(&cmd->se_lun->lun_sep_lock);
1162 	return 0;
1163 }
1164 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1165 
1166 /*
1167  * Used by fabric module frontends to queue tasks directly.
1168  * Many only be used from process context only
1169  */
1170 int transport_handle_cdb_direct(
1171 	struct se_cmd *cmd)
1172 {
1173 	sense_reason_t ret;
1174 
1175 	if (!cmd->se_lun) {
1176 		dump_stack();
1177 		pr_err("cmd->se_lun is NULL\n");
1178 		return -EINVAL;
1179 	}
1180 	if (in_interrupt()) {
1181 		dump_stack();
1182 		pr_err("transport_generic_handle_cdb cannot be called"
1183 				" from interrupt context\n");
1184 		return -EINVAL;
1185 	}
1186 	/*
1187 	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1188 	 * outstanding descriptors are handled correctly during shutdown via
1189 	 * transport_wait_for_tasks()
1190 	 *
1191 	 * Also, we don't take cmd->t_state_lock here as we only expect
1192 	 * this to be called for initial descriptor submission.
1193 	 */
1194 	cmd->t_state = TRANSPORT_NEW_CMD;
1195 	cmd->transport_state |= CMD_T_ACTIVE;
1196 
1197 	/*
1198 	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1199 	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1200 	 * and call transport_generic_request_failure() if necessary..
1201 	 */
1202 	ret = transport_generic_new_cmd(cmd);
1203 	if (ret)
1204 		transport_generic_request_failure(cmd, ret);
1205 	return 0;
1206 }
1207 EXPORT_SYMBOL(transport_handle_cdb_direct);
1208 
1209 static sense_reason_t
1210 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1211 		u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1212 {
1213 	if (!sgl || !sgl_count)
1214 		return 0;
1215 
1216 	/*
1217 	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1218 	 * scatterlists already have been set to follow what the fabric
1219 	 * passes for the original expected data transfer length.
1220 	 */
1221 	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1222 		pr_warn("Rejecting SCSI DATA overflow for fabric using"
1223 			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1224 		return TCM_INVALID_CDB_FIELD;
1225 	}
1226 
1227 	cmd->t_data_sg = sgl;
1228 	cmd->t_data_nents = sgl_count;
1229 
1230 	if (sgl_bidi && sgl_bidi_count) {
1231 		cmd->t_bidi_data_sg = sgl_bidi;
1232 		cmd->t_bidi_data_nents = sgl_bidi_count;
1233 	}
1234 	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1235 	return 0;
1236 }
1237 
1238 /*
1239  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1240  * 			 se_cmd + use pre-allocated SGL memory.
1241  *
1242  * @se_cmd: command descriptor to submit
1243  * @se_sess: associated se_sess for endpoint
1244  * @cdb: pointer to SCSI CDB
1245  * @sense: pointer to SCSI sense buffer
1246  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1247  * @data_length: fabric expected data transfer length
1248  * @task_addr: SAM task attribute
1249  * @data_dir: DMA data direction
1250  * @flags: flags for command submission from target_sc_flags_tables
1251  * @sgl: struct scatterlist memory for unidirectional mapping
1252  * @sgl_count: scatterlist count for unidirectional mapping
1253  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1254  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1255  *
1256  * Returns non zero to signal active I/O shutdown failure.  All other
1257  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1258  * but still return zero here.
1259  *
1260  * This may only be called from process context, and also currently
1261  * assumes internal allocation of fabric payload buffer by target-core.
1262  */
1263 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1264 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1265 		u32 data_length, int task_attr, int data_dir, int flags,
1266 		struct scatterlist *sgl, u32 sgl_count,
1267 		struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1268 {
1269 	struct se_portal_group *se_tpg;
1270 	sense_reason_t rc;
1271 	int ret;
1272 
1273 	se_tpg = se_sess->se_tpg;
1274 	BUG_ON(!se_tpg);
1275 	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1276 	BUG_ON(in_interrupt());
1277 	/*
1278 	 * Initialize se_cmd for target operation.  From this point
1279 	 * exceptions are handled by sending exception status via
1280 	 * target_core_fabric_ops->queue_status() callback
1281 	 */
1282 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1283 				data_length, data_dir, task_attr, sense);
1284 	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1285 		se_cmd->unknown_data_length = 1;
1286 	/*
1287 	 * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1288 	 * se_sess->sess_cmd_list.  A second kref_get here is necessary
1289 	 * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1290 	 * kref_put() to happen during fabric packet acknowledgement.
1291 	 */
1292 	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1293 	if (ret)
1294 		return ret;
1295 	/*
1296 	 * Signal bidirectional data payloads to target-core
1297 	 */
1298 	if (flags & TARGET_SCF_BIDI_OP)
1299 		se_cmd->se_cmd_flags |= SCF_BIDI;
1300 	/*
1301 	 * Locate se_lun pointer and attach it to struct se_cmd
1302 	 */
1303 	rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1304 	if (rc) {
1305 		transport_send_check_condition_and_sense(se_cmd, rc, 0);
1306 		target_put_sess_cmd(se_sess, se_cmd);
1307 		return 0;
1308 	}
1309 
1310 	rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1311 	if (rc != 0) {
1312 		transport_generic_request_failure(se_cmd, rc);
1313 		return 0;
1314 	}
1315 	/*
1316 	 * When a non zero sgl_count has been passed perform SGL passthrough
1317 	 * mapping for pre-allocated fabric memory instead of having target
1318 	 * core perform an internal SGL allocation..
1319 	 */
1320 	if (sgl_count != 0) {
1321 		BUG_ON(!sgl);
1322 
1323 		/*
1324 		 * A work-around for tcm_loop as some userspace code via
1325 		 * scsi-generic do not memset their associated read buffers,
1326 		 * so go ahead and do that here for type non-data CDBs.  Also
1327 		 * note that this is currently guaranteed to be a single SGL
1328 		 * for this case by target core in target_setup_cmd_from_cdb()
1329 		 * -> transport_generic_cmd_sequencer().
1330 		 */
1331 		if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1332 		     se_cmd->data_direction == DMA_FROM_DEVICE) {
1333 			unsigned char *buf = NULL;
1334 
1335 			if (sgl)
1336 				buf = kmap(sg_page(sgl)) + sgl->offset;
1337 
1338 			if (buf) {
1339 				memset(buf, 0, sgl->length);
1340 				kunmap(sg_page(sgl));
1341 			}
1342 		}
1343 
1344 		rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1345 				sgl_bidi, sgl_bidi_count);
1346 		if (rc != 0) {
1347 			transport_generic_request_failure(se_cmd, rc);
1348 			return 0;
1349 		}
1350 	}
1351 	/*
1352 	 * Check if we need to delay processing because of ALUA
1353 	 * Active/NonOptimized primary access state..
1354 	 */
1355 	core_alua_check_nonop_delay(se_cmd);
1356 
1357 	transport_handle_cdb_direct(se_cmd);
1358 	return 0;
1359 }
1360 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1361 
1362 /*
1363  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1364  *
1365  * @se_cmd: command descriptor to submit
1366  * @se_sess: associated se_sess for endpoint
1367  * @cdb: pointer to SCSI CDB
1368  * @sense: pointer to SCSI sense buffer
1369  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1370  * @data_length: fabric expected data transfer length
1371  * @task_addr: SAM task attribute
1372  * @data_dir: DMA data direction
1373  * @flags: flags for command submission from target_sc_flags_tables
1374  *
1375  * Returns non zero to signal active I/O shutdown failure.  All other
1376  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1377  * but still return zero here.
1378  *
1379  * This may only be called from process context, and also currently
1380  * assumes internal allocation of fabric payload buffer by target-core.
1381  *
1382  * It also assumes interal target core SGL memory allocation.
1383  */
1384 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1385 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1386 		u32 data_length, int task_attr, int data_dir, int flags)
1387 {
1388 	return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1389 			unpacked_lun, data_length, task_attr, data_dir,
1390 			flags, NULL, 0, NULL, 0);
1391 }
1392 EXPORT_SYMBOL(target_submit_cmd);
1393 
1394 static void target_complete_tmr_failure(struct work_struct *work)
1395 {
1396 	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1397 
1398 	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1399 	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1400 
1401 	transport_cmd_check_stop_to_fabric(se_cmd);
1402 }
1403 
1404 /**
1405  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1406  *                     for TMR CDBs
1407  *
1408  * @se_cmd: command descriptor to submit
1409  * @se_sess: associated se_sess for endpoint
1410  * @sense: pointer to SCSI sense buffer
1411  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1412  * @fabric_context: fabric context for TMR req
1413  * @tm_type: Type of TM request
1414  * @gfp: gfp type for caller
1415  * @tag: referenced task tag for TMR_ABORT_TASK
1416  * @flags: submit cmd flags
1417  *
1418  * Callable from all contexts.
1419  **/
1420 
1421 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1422 		unsigned char *sense, u32 unpacked_lun,
1423 		void *fabric_tmr_ptr, unsigned char tm_type,
1424 		gfp_t gfp, unsigned int tag, int flags)
1425 {
1426 	struct se_portal_group *se_tpg;
1427 	int ret;
1428 
1429 	se_tpg = se_sess->se_tpg;
1430 	BUG_ON(!se_tpg);
1431 
1432 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1433 			      0, DMA_NONE, MSG_SIMPLE_TAG, sense);
1434 	/*
1435 	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1436 	 * allocation failure.
1437 	 */
1438 	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1439 	if (ret < 0)
1440 		return -ENOMEM;
1441 
1442 	if (tm_type == TMR_ABORT_TASK)
1443 		se_cmd->se_tmr_req->ref_task_tag = tag;
1444 
1445 	/* See target_submit_cmd for commentary */
1446 	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1447 	if (ret) {
1448 		core_tmr_release_req(se_cmd->se_tmr_req);
1449 		return ret;
1450 	}
1451 
1452 	ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1453 	if (ret) {
1454 		/*
1455 		 * For callback during failure handling, push this work off
1456 		 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1457 		 */
1458 		INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1459 		schedule_work(&se_cmd->work);
1460 		return 0;
1461 	}
1462 	transport_generic_handle_tmr(se_cmd);
1463 	return 0;
1464 }
1465 EXPORT_SYMBOL(target_submit_tmr);
1466 
1467 /*
1468  * If the cmd is active, request it to be stopped and sleep until it
1469  * has completed.
1470  */
1471 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1472 {
1473 	bool was_active = false;
1474 
1475 	if (cmd->transport_state & CMD_T_BUSY) {
1476 		cmd->transport_state |= CMD_T_REQUEST_STOP;
1477 		spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1478 
1479 		pr_debug("cmd %p waiting to complete\n", cmd);
1480 		wait_for_completion(&cmd->task_stop_comp);
1481 		pr_debug("cmd %p stopped successfully\n", cmd);
1482 
1483 		spin_lock_irqsave(&cmd->t_state_lock, *flags);
1484 		cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1485 		cmd->transport_state &= ~CMD_T_BUSY;
1486 		was_active = true;
1487 	}
1488 
1489 	return was_active;
1490 }
1491 
1492 /*
1493  * Handle SAM-esque emulation for generic transport request failures.
1494  */
1495 void transport_generic_request_failure(struct se_cmd *cmd,
1496 		sense_reason_t sense_reason)
1497 {
1498 	int ret = 0;
1499 
1500 	pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
1501 		" CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
1502 		cmd->t_task_cdb[0]);
1503 	pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1504 		cmd->se_tfo->get_cmd_state(cmd),
1505 		cmd->t_state, sense_reason);
1506 	pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1507 		(cmd->transport_state & CMD_T_ACTIVE) != 0,
1508 		(cmd->transport_state & CMD_T_STOP) != 0,
1509 		(cmd->transport_state & CMD_T_SENT) != 0);
1510 
1511 	/*
1512 	 * For SAM Task Attribute emulation for failed struct se_cmd
1513 	 */
1514 	transport_complete_task_attr(cmd);
1515 
1516 	switch (sense_reason) {
1517 	case TCM_NON_EXISTENT_LUN:
1518 	case TCM_UNSUPPORTED_SCSI_OPCODE:
1519 	case TCM_INVALID_CDB_FIELD:
1520 	case TCM_INVALID_PARAMETER_LIST:
1521 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
1522 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1523 	case TCM_UNKNOWN_MODE_PAGE:
1524 	case TCM_WRITE_PROTECTED:
1525 	case TCM_ADDRESS_OUT_OF_RANGE:
1526 	case TCM_CHECK_CONDITION_ABORT_CMD:
1527 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1528 	case TCM_CHECK_CONDITION_NOT_READY:
1529 		break;
1530 	case TCM_OUT_OF_RESOURCES:
1531 		sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1532 		break;
1533 	case TCM_RESERVATION_CONFLICT:
1534 		/*
1535 		 * No SENSE Data payload for this case, set SCSI Status
1536 		 * and queue the response to $FABRIC_MOD.
1537 		 *
1538 		 * Uses linux/include/scsi/scsi.h SAM status codes defs
1539 		 */
1540 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1541 		/*
1542 		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1543 		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1544 		 * CONFLICT STATUS.
1545 		 *
1546 		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1547 		 */
1548 		if (cmd->se_sess &&
1549 		    cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2)
1550 			core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
1551 				cmd->orig_fe_lun, 0x2C,
1552 				ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1553 
1554 		trace_target_cmd_complete(cmd);
1555 		ret = cmd->se_tfo-> queue_status(cmd);
1556 		if (ret == -EAGAIN || ret == -ENOMEM)
1557 			goto queue_full;
1558 		goto check_stop;
1559 	default:
1560 		pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1561 			cmd->t_task_cdb[0], sense_reason);
1562 		sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1563 		break;
1564 	}
1565 
1566 	ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1567 	if (ret == -EAGAIN || ret == -ENOMEM)
1568 		goto queue_full;
1569 
1570 check_stop:
1571 	transport_lun_remove_cmd(cmd);
1572 	if (!transport_cmd_check_stop_to_fabric(cmd))
1573 		;
1574 	return;
1575 
1576 queue_full:
1577 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1578 	transport_handle_queue_full(cmd, cmd->se_dev);
1579 }
1580 EXPORT_SYMBOL(transport_generic_request_failure);
1581 
1582 static void __target_execute_cmd(struct se_cmd *cmd)
1583 {
1584 	sense_reason_t ret;
1585 
1586 	if (cmd->execute_cmd) {
1587 		ret = cmd->execute_cmd(cmd);
1588 		if (ret) {
1589 			spin_lock_irq(&cmd->t_state_lock);
1590 			cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1591 			spin_unlock_irq(&cmd->t_state_lock);
1592 
1593 			transport_generic_request_failure(cmd, ret);
1594 		}
1595 	}
1596 }
1597 
1598 static bool target_handle_task_attr(struct se_cmd *cmd)
1599 {
1600 	struct se_device *dev = cmd->se_dev;
1601 
1602 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1603 		return false;
1604 
1605 	/*
1606 	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1607 	 * to allow the passed struct se_cmd list of tasks to the front of the list.
1608 	 */
1609 	switch (cmd->sam_task_attr) {
1610 	case MSG_HEAD_TAG:
1611 		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
1612 			 "se_ordered_id: %u\n",
1613 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1614 		return false;
1615 	case MSG_ORDERED_TAG:
1616 		atomic_inc(&dev->dev_ordered_sync);
1617 		smp_mb__after_atomic_inc();
1618 
1619 		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
1620 			 " se_ordered_id: %u\n",
1621 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1622 
1623 		/*
1624 		 * Execute an ORDERED command if no other older commands
1625 		 * exist that need to be completed first.
1626 		 */
1627 		if (!atomic_read(&dev->simple_cmds))
1628 			return false;
1629 		break;
1630 	default:
1631 		/*
1632 		 * For SIMPLE and UNTAGGED Task Attribute commands
1633 		 */
1634 		atomic_inc(&dev->simple_cmds);
1635 		smp_mb__after_atomic_inc();
1636 		break;
1637 	}
1638 
1639 	if (atomic_read(&dev->dev_ordered_sync) == 0)
1640 		return false;
1641 
1642 	spin_lock(&dev->delayed_cmd_lock);
1643 	list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1644 	spin_unlock(&dev->delayed_cmd_lock);
1645 
1646 	pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
1647 		" delayed CMD list, se_ordered_id: %u\n",
1648 		cmd->t_task_cdb[0], cmd->sam_task_attr,
1649 		cmd->se_ordered_id);
1650 	return true;
1651 }
1652 
1653 void target_execute_cmd(struct se_cmd *cmd)
1654 {
1655 	/*
1656 	 * If the received CDB has aleady been aborted stop processing it here.
1657 	 */
1658 	if (transport_check_aborted_status(cmd, 1)) {
1659 		complete(&cmd->transport_lun_stop_comp);
1660 		return;
1661 	}
1662 
1663 	/*
1664 	 * Determine if IOCTL context caller in requesting the stopping of this
1665 	 * command for LUN shutdown purposes.
1666 	 */
1667 	spin_lock_irq(&cmd->t_state_lock);
1668 	if (cmd->transport_state & CMD_T_LUN_STOP) {
1669 		pr_debug("%s:%d CMD_T_LUN_STOP for ITT: 0x%08x\n",
1670 			__func__, __LINE__, cmd->se_tfo->get_task_tag(cmd));
1671 
1672 		cmd->transport_state &= ~CMD_T_ACTIVE;
1673 		spin_unlock_irq(&cmd->t_state_lock);
1674 		complete(&cmd->transport_lun_stop_comp);
1675 		return;
1676 	}
1677 	/*
1678 	 * Determine if frontend context caller is requesting the stopping of
1679 	 * this command for frontend exceptions.
1680 	 */
1681 	if (cmd->transport_state & CMD_T_STOP) {
1682 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
1683 			__func__, __LINE__,
1684 			cmd->se_tfo->get_task_tag(cmd));
1685 
1686 		spin_unlock_irq(&cmd->t_state_lock);
1687 		complete(&cmd->t_transport_stop_comp);
1688 		return;
1689 	}
1690 
1691 	cmd->t_state = TRANSPORT_PROCESSING;
1692 	cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1693 	spin_unlock_irq(&cmd->t_state_lock);
1694 
1695 	if (target_handle_task_attr(cmd)) {
1696 		spin_lock_irq(&cmd->t_state_lock);
1697 		cmd->transport_state &= ~CMD_T_BUSY|CMD_T_SENT;
1698 		spin_unlock_irq(&cmd->t_state_lock);
1699 		return;
1700 	}
1701 
1702 	__target_execute_cmd(cmd);
1703 }
1704 EXPORT_SYMBOL(target_execute_cmd);
1705 
1706 /*
1707  * Process all commands up to the last received ORDERED task attribute which
1708  * requires another blocking boundary
1709  */
1710 static void target_restart_delayed_cmds(struct se_device *dev)
1711 {
1712 	for (;;) {
1713 		struct se_cmd *cmd;
1714 
1715 		spin_lock(&dev->delayed_cmd_lock);
1716 		if (list_empty(&dev->delayed_cmd_list)) {
1717 			spin_unlock(&dev->delayed_cmd_lock);
1718 			break;
1719 		}
1720 
1721 		cmd = list_entry(dev->delayed_cmd_list.next,
1722 				 struct se_cmd, se_delayed_node);
1723 		list_del(&cmd->se_delayed_node);
1724 		spin_unlock(&dev->delayed_cmd_lock);
1725 
1726 		__target_execute_cmd(cmd);
1727 
1728 		if (cmd->sam_task_attr == MSG_ORDERED_TAG)
1729 			break;
1730 	}
1731 }
1732 
1733 /*
1734  * Called from I/O completion to determine which dormant/delayed
1735  * and ordered cmds need to have their tasks added to the execution queue.
1736  */
1737 static void transport_complete_task_attr(struct se_cmd *cmd)
1738 {
1739 	struct se_device *dev = cmd->se_dev;
1740 
1741 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1742 		return;
1743 
1744 	if (cmd->sam_task_attr == MSG_SIMPLE_TAG) {
1745 		atomic_dec(&dev->simple_cmds);
1746 		smp_mb__after_atomic_dec();
1747 		dev->dev_cur_ordered_id++;
1748 		pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
1749 			" SIMPLE: %u\n", dev->dev_cur_ordered_id,
1750 			cmd->se_ordered_id);
1751 	} else if (cmd->sam_task_attr == MSG_HEAD_TAG) {
1752 		dev->dev_cur_ordered_id++;
1753 		pr_debug("Incremented dev_cur_ordered_id: %u for"
1754 			" HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
1755 			cmd->se_ordered_id);
1756 	} else if (cmd->sam_task_attr == MSG_ORDERED_TAG) {
1757 		atomic_dec(&dev->dev_ordered_sync);
1758 		smp_mb__after_atomic_dec();
1759 
1760 		dev->dev_cur_ordered_id++;
1761 		pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
1762 			" %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
1763 	}
1764 
1765 	target_restart_delayed_cmds(dev);
1766 }
1767 
1768 static void transport_complete_qf(struct se_cmd *cmd)
1769 {
1770 	int ret = 0;
1771 
1772 	transport_complete_task_attr(cmd);
1773 
1774 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1775 		trace_target_cmd_complete(cmd);
1776 		ret = cmd->se_tfo->queue_status(cmd);
1777 		if (ret)
1778 			goto out;
1779 	}
1780 
1781 	switch (cmd->data_direction) {
1782 	case DMA_FROM_DEVICE:
1783 		trace_target_cmd_complete(cmd);
1784 		ret = cmd->se_tfo->queue_data_in(cmd);
1785 		break;
1786 	case DMA_TO_DEVICE:
1787 		if (cmd->t_bidi_data_sg) {
1788 			ret = cmd->se_tfo->queue_data_in(cmd);
1789 			if (ret < 0)
1790 				break;
1791 		}
1792 		/* Fall through for DMA_TO_DEVICE */
1793 	case DMA_NONE:
1794 		trace_target_cmd_complete(cmd);
1795 		ret = cmd->se_tfo->queue_status(cmd);
1796 		break;
1797 	default:
1798 		break;
1799 	}
1800 
1801 out:
1802 	if (ret < 0) {
1803 		transport_handle_queue_full(cmd, cmd->se_dev);
1804 		return;
1805 	}
1806 	transport_lun_remove_cmd(cmd);
1807 	transport_cmd_check_stop_to_fabric(cmd);
1808 }
1809 
1810 static void transport_handle_queue_full(
1811 	struct se_cmd *cmd,
1812 	struct se_device *dev)
1813 {
1814 	spin_lock_irq(&dev->qf_cmd_lock);
1815 	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
1816 	atomic_inc(&dev->dev_qf_count);
1817 	smp_mb__after_atomic_inc();
1818 	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
1819 
1820 	schedule_work(&cmd->se_dev->qf_work_queue);
1821 }
1822 
1823 static void target_complete_ok_work(struct work_struct *work)
1824 {
1825 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
1826 	int ret;
1827 
1828 	/*
1829 	 * Check if we need to move delayed/dormant tasks from cmds on the
1830 	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
1831 	 * Attribute.
1832 	 */
1833 	transport_complete_task_attr(cmd);
1834 
1835 	/*
1836 	 * Check to schedule QUEUE_FULL work, or execute an existing
1837 	 * cmd->transport_qf_callback()
1838 	 */
1839 	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
1840 		schedule_work(&cmd->se_dev->qf_work_queue);
1841 
1842 	/*
1843 	 * Check if we need to send a sense buffer from
1844 	 * the struct se_cmd in question.
1845 	 */
1846 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1847 		WARN_ON(!cmd->scsi_status);
1848 		ret = transport_send_check_condition_and_sense(
1849 					cmd, 0, 1);
1850 		if (ret == -EAGAIN || ret == -ENOMEM)
1851 			goto queue_full;
1852 
1853 		transport_lun_remove_cmd(cmd);
1854 		transport_cmd_check_stop_to_fabric(cmd);
1855 		return;
1856 	}
1857 	/*
1858 	 * Check for a callback, used by amongst other things
1859 	 * XDWRITE_READ_10 emulation.
1860 	 */
1861 	if (cmd->transport_complete_callback)
1862 		cmd->transport_complete_callback(cmd);
1863 
1864 	switch (cmd->data_direction) {
1865 	case DMA_FROM_DEVICE:
1866 		spin_lock(&cmd->se_lun->lun_sep_lock);
1867 		if (cmd->se_lun->lun_sep) {
1868 			cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
1869 					cmd->data_length;
1870 		}
1871 		spin_unlock(&cmd->se_lun->lun_sep_lock);
1872 
1873 		trace_target_cmd_complete(cmd);
1874 		ret = cmd->se_tfo->queue_data_in(cmd);
1875 		if (ret == -EAGAIN || ret == -ENOMEM)
1876 			goto queue_full;
1877 		break;
1878 	case DMA_TO_DEVICE:
1879 		spin_lock(&cmd->se_lun->lun_sep_lock);
1880 		if (cmd->se_lun->lun_sep) {
1881 			cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
1882 				cmd->data_length;
1883 		}
1884 		spin_unlock(&cmd->se_lun->lun_sep_lock);
1885 		/*
1886 		 * Check if we need to send READ payload for BIDI-COMMAND
1887 		 */
1888 		if (cmd->t_bidi_data_sg) {
1889 			spin_lock(&cmd->se_lun->lun_sep_lock);
1890 			if (cmd->se_lun->lun_sep) {
1891 				cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
1892 					cmd->data_length;
1893 			}
1894 			spin_unlock(&cmd->se_lun->lun_sep_lock);
1895 			ret = cmd->se_tfo->queue_data_in(cmd);
1896 			if (ret == -EAGAIN || ret == -ENOMEM)
1897 				goto queue_full;
1898 			break;
1899 		}
1900 		/* Fall through for DMA_TO_DEVICE */
1901 	case DMA_NONE:
1902 		trace_target_cmd_complete(cmd);
1903 		ret = cmd->se_tfo->queue_status(cmd);
1904 		if (ret == -EAGAIN || ret == -ENOMEM)
1905 			goto queue_full;
1906 		break;
1907 	default:
1908 		break;
1909 	}
1910 
1911 	transport_lun_remove_cmd(cmd);
1912 	transport_cmd_check_stop_to_fabric(cmd);
1913 	return;
1914 
1915 queue_full:
1916 	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
1917 		" data_direction: %d\n", cmd, cmd->data_direction);
1918 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1919 	transport_handle_queue_full(cmd, cmd->se_dev);
1920 }
1921 
1922 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
1923 {
1924 	struct scatterlist *sg;
1925 	int count;
1926 
1927 	for_each_sg(sgl, sg, nents, count)
1928 		__free_page(sg_page(sg));
1929 
1930 	kfree(sgl);
1931 }
1932 
1933 static inline void transport_free_pages(struct se_cmd *cmd)
1934 {
1935 	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC)
1936 		return;
1937 
1938 	transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
1939 	cmd->t_data_sg = NULL;
1940 	cmd->t_data_nents = 0;
1941 
1942 	transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
1943 	cmd->t_bidi_data_sg = NULL;
1944 	cmd->t_bidi_data_nents = 0;
1945 }
1946 
1947 /**
1948  * transport_release_cmd - free a command
1949  * @cmd:       command to free
1950  *
1951  * This routine unconditionally frees a command, and reference counting
1952  * or list removal must be done in the caller.
1953  */
1954 static int transport_release_cmd(struct se_cmd *cmd)
1955 {
1956 	BUG_ON(!cmd->se_tfo);
1957 
1958 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
1959 		core_tmr_release_req(cmd->se_tmr_req);
1960 	if (cmd->t_task_cdb != cmd->__t_task_cdb)
1961 		kfree(cmd->t_task_cdb);
1962 	/*
1963 	 * If this cmd has been setup with target_get_sess_cmd(), drop
1964 	 * the kref and call ->release_cmd() in kref callback.
1965 	 */
1966 	return target_put_sess_cmd(cmd->se_sess, cmd);
1967 }
1968 
1969 /**
1970  * transport_put_cmd - release a reference to a command
1971  * @cmd:       command to release
1972  *
1973  * This routine releases our reference to the command and frees it if possible.
1974  */
1975 static int transport_put_cmd(struct se_cmd *cmd)
1976 {
1977 	transport_free_pages(cmd);
1978 	return transport_release_cmd(cmd);
1979 }
1980 
1981 void *transport_kmap_data_sg(struct se_cmd *cmd)
1982 {
1983 	struct scatterlist *sg = cmd->t_data_sg;
1984 	struct page **pages;
1985 	int i;
1986 
1987 	/*
1988 	 * We need to take into account a possible offset here for fabrics like
1989 	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
1990 	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
1991 	 */
1992 	if (!cmd->t_data_nents)
1993 		return NULL;
1994 
1995 	BUG_ON(!sg);
1996 	if (cmd->t_data_nents == 1)
1997 		return kmap(sg_page(sg)) + sg->offset;
1998 
1999 	/* >1 page. use vmap */
2000 	pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2001 	if (!pages)
2002 		return NULL;
2003 
2004 	/* convert sg[] to pages[] */
2005 	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2006 		pages[i] = sg_page(sg);
2007 	}
2008 
2009 	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2010 	kfree(pages);
2011 	if (!cmd->t_data_vmap)
2012 		return NULL;
2013 
2014 	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2015 }
2016 EXPORT_SYMBOL(transport_kmap_data_sg);
2017 
2018 void transport_kunmap_data_sg(struct se_cmd *cmd)
2019 {
2020 	if (!cmd->t_data_nents) {
2021 		return;
2022 	} else if (cmd->t_data_nents == 1) {
2023 		kunmap(sg_page(cmd->t_data_sg));
2024 		return;
2025 	}
2026 
2027 	vunmap(cmd->t_data_vmap);
2028 	cmd->t_data_vmap = NULL;
2029 }
2030 EXPORT_SYMBOL(transport_kunmap_data_sg);
2031 
2032 static int
2033 transport_generic_get_mem(struct se_cmd *cmd)
2034 {
2035 	u32 length = cmd->data_length;
2036 	unsigned int nents;
2037 	struct page *page;
2038 	gfp_t zero_flag;
2039 	int i = 0;
2040 
2041 	nents = DIV_ROUND_UP(length, PAGE_SIZE);
2042 	cmd->t_data_sg = kmalloc(sizeof(struct scatterlist) * nents, GFP_KERNEL);
2043 	if (!cmd->t_data_sg)
2044 		return -ENOMEM;
2045 
2046 	cmd->t_data_nents = nents;
2047 	sg_init_table(cmd->t_data_sg, nents);
2048 
2049 	zero_flag = cmd->se_cmd_flags & SCF_SCSI_DATA_CDB ? 0 : __GFP_ZERO;
2050 
2051 	while (length) {
2052 		u32 page_len = min_t(u32, length, PAGE_SIZE);
2053 		page = alloc_page(GFP_KERNEL | zero_flag);
2054 		if (!page)
2055 			goto out;
2056 
2057 		sg_set_page(&cmd->t_data_sg[i], page, page_len, 0);
2058 		length -= page_len;
2059 		i++;
2060 	}
2061 	return 0;
2062 
2063 out:
2064 	while (i > 0) {
2065 		i--;
2066 		__free_page(sg_page(&cmd->t_data_sg[i]));
2067 	}
2068 	kfree(cmd->t_data_sg);
2069 	cmd->t_data_sg = NULL;
2070 	return -ENOMEM;
2071 }
2072 
2073 /*
2074  * Allocate any required resources to execute the command.  For writes we
2075  * might not have the payload yet, so notify the fabric via a call to
2076  * ->write_pending instead. Otherwise place it on the execution queue.
2077  */
2078 sense_reason_t
2079 transport_generic_new_cmd(struct se_cmd *cmd)
2080 {
2081 	int ret = 0;
2082 
2083 	/*
2084 	 * Determine is the TCM fabric module has already allocated physical
2085 	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2086 	 * beforehand.
2087 	 */
2088 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2089 	    cmd->data_length) {
2090 		ret = transport_generic_get_mem(cmd);
2091 		if (ret < 0)
2092 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2093 	}
2094 	/*
2095 	 * If this command is not a write we can execute it right here,
2096 	 * for write buffers we need to notify the fabric driver first
2097 	 * and let it call back once the write buffers are ready.
2098 	 */
2099 	target_add_to_state_list(cmd);
2100 	if (cmd->data_direction != DMA_TO_DEVICE) {
2101 		target_execute_cmd(cmd);
2102 		return 0;
2103 	}
2104 	transport_cmd_check_stop(cmd, false, true);
2105 
2106 	ret = cmd->se_tfo->write_pending(cmd);
2107 	if (ret == -EAGAIN || ret == -ENOMEM)
2108 		goto queue_full;
2109 
2110 	/* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2111 	WARN_ON(ret);
2112 
2113 	return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2114 
2115 queue_full:
2116 	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2117 	cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2118 	transport_handle_queue_full(cmd, cmd->se_dev);
2119 	return 0;
2120 }
2121 EXPORT_SYMBOL(transport_generic_new_cmd);
2122 
2123 static void transport_write_pending_qf(struct se_cmd *cmd)
2124 {
2125 	int ret;
2126 
2127 	ret = cmd->se_tfo->write_pending(cmd);
2128 	if (ret == -EAGAIN || ret == -ENOMEM) {
2129 		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2130 			 cmd);
2131 		transport_handle_queue_full(cmd, cmd->se_dev);
2132 	}
2133 }
2134 
2135 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2136 {
2137 	int ret = 0;
2138 
2139 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2140 		if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2141 			 transport_wait_for_tasks(cmd);
2142 
2143 		ret = transport_release_cmd(cmd);
2144 	} else {
2145 		if (wait_for_tasks)
2146 			transport_wait_for_tasks(cmd);
2147 
2148 		if (cmd->se_lun)
2149 			transport_lun_remove_cmd(cmd);
2150 
2151 		ret = transport_put_cmd(cmd);
2152 	}
2153 	return ret;
2154 }
2155 EXPORT_SYMBOL(transport_generic_free_cmd);
2156 
2157 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2158  * @se_sess:	session to reference
2159  * @se_cmd:	command descriptor to add
2160  * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
2161  */
2162 int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
2163 			       bool ack_kref)
2164 {
2165 	unsigned long flags;
2166 	int ret = 0;
2167 
2168 	kref_init(&se_cmd->cmd_kref);
2169 	/*
2170 	 * Add a second kref if the fabric caller is expecting to handle
2171 	 * fabric acknowledgement that requires two target_put_sess_cmd()
2172 	 * invocations before se_cmd descriptor release.
2173 	 */
2174 	if (ack_kref == true) {
2175 		kref_get(&se_cmd->cmd_kref);
2176 		se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2177 	}
2178 
2179 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2180 	if (se_sess->sess_tearing_down) {
2181 		ret = -ESHUTDOWN;
2182 		goto out;
2183 	}
2184 	list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2185 out:
2186 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2187 	return ret;
2188 }
2189 EXPORT_SYMBOL(target_get_sess_cmd);
2190 
2191 static void target_release_cmd_kref(struct kref *kref)
2192 {
2193 	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2194 	struct se_session *se_sess = se_cmd->se_sess;
2195 
2196 	if (list_empty(&se_cmd->se_cmd_list)) {
2197 		spin_unlock(&se_sess->sess_cmd_lock);
2198 		se_cmd->se_tfo->release_cmd(se_cmd);
2199 		return;
2200 	}
2201 	if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2202 		spin_unlock(&se_sess->sess_cmd_lock);
2203 		complete(&se_cmd->cmd_wait_comp);
2204 		return;
2205 	}
2206 	list_del(&se_cmd->se_cmd_list);
2207 	spin_unlock(&se_sess->sess_cmd_lock);
2208 
2209 	se_cmd->se_tfo->release_cmd(se_cmd);
2210 }
2211 
2212 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2213  * @se_sess:	session to reference
2214  * @se_cmd:	command descriptor to drop
2215  */
2216 int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd)
2217 {
2218 	return kref_put_spinlock_irqsave(&se_cmd->cmd_kref, target_release_cmd_kref,
2219 			&se_sess->sess_cmd_lock);
2220 }
2221 EXPORT_SYMBOL(target_put_sess_cmd);
2222 
2223 /* target_sess_cmd_list_set_waiting - Flag all commands in
2224  *         sess_cmd_list to complete cmd_wait_comp.  Set
2225  *         sess_tearing_down so no more commands are queued.
2226  * @se_sess:	session to flag
2227  */
2228 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2229 {
2230 	struct se_cmd *se_cmd;
2231 	unsigned long flags;
2232 
2233 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2234 	if (se_sess->sess_tearing_down) {
2235 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2236 		return;
2237 	}
2238 	se_sess->sess_tearing_down = 1;
2239 	list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2240 
2241 	list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list)
2242 		se_cmd->cmd_wait_set = 1;
2243 
2244 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2245 }
2246 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2247 
2248 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2249  * @se_sess:    session to wait for active I/O
2250  */
2251 void target_wait_for_sess_cmds(struct se_session *se_sess)
2252 {
2253 	struct se_cmd *se_cmd, *tmp_cmd;
2254 	unsigned long flags;
2255 
2256 	list_for_each_entry_safe(se_cmd, tmp_cmd,
2257 				&se_sess->sess_wait_list, se_cmd_list) {
2258 		list_del(&se_cmd->se_cmd_list);
2259 
2260 		pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2261 			" %d\n", se_cmd, se_cmd->t_state,
2262 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2263 
2264 		wait_for_completion(&se_cmd->cmd_wait_comp);
2265 		pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2266 			" fabric state: %d\n", se_cmd, se_cmd->t_state,
2267 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2268 
2269 		se_cmd->se_tfo->release_cmd(se_cmd);
2270 	}
2271 
2272 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2273 	WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2274 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2275 
2276 }
2277 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2278 
2279 /*	transport_lun_wait_for_tasks():
2280  *
2281  *	Called from ConfigFS context to stop the passed struct se_cmd to allow
2282  *	an struct se_lun to be successfully shutdown.
2283  */
2284 static int transport_lun_wait_for_tasks(struct se_cmd *cmd, struct se_lun *lun)
2285 {
2286 	unsigned long flags;
2287 	int ret = 0;
2288 
2289 	/*
2290 	 * If the frontend has already requested this struct se_cmd to
2291 	 * be stopped, we can safely ignore this struct se_cmd.
2292 	 */
2293 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2294 	if (cmd->transport_state & CMD_T_STOP) {
2295 		cmd->transport_state &= ~CMD_T_LUN_STOP;
2296 
2297 		pr_debug("ConfigFS ITT[0x%08x] - CMD_T_STOP, skipping\n",
2298 			 cmd->se_tfo->get_task_tag(cmd));
2299 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2300 		transport_cmd_check_stop(cmd, false, false);
2301 		return -EPERM;
2302 	}
2303 	cmd->transport_state |= CMD_T_LUN_FE_STOP;
2304 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2305 
2306 	// XXX: audit task_flags checks.
2307 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2308 	if ((cmd->transport_state & CMD_T_BUSY) &&
2309 	    (cmd->transport_state & CMD_T_SENT)) {
2310 		if (!target_stop_cmd(cmd, &flags))
2311 			ret++;
2312 	}
2313 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2314 
2315 	pr_debug("ConfigFS: cmd: %p stop tasks ret:"
2316 			" %d\n", cmd, ret);
2317 	if (!ret) {
2318 		pr_debug("ConfigFS: ITT[0x%08x] - stopping cmd....\n",
2319 				cmd->se_tfo->get_task_tag(cmd));
2320 		wait_for_completion(&cmd->transport_lun_stop_comp);
2321 		pr_debug("ConfigFS: ITT[0x%08x] - stopped cmd....\n",
2322 				cmd->se_tfo->get_task_tag(cmd));
2323 	}
2324 
2325 	return 0;
2326 }
2327 
2328 static void __transport_clear_lun_from_sessions(struct se_lun *lun)
2329 {
2330 	struct se_cmd *cmd = NULL;
2331 	unsigned long lun_flags, cmd_flags;
2332 	/*
2333 	 * Do exception processing and return CHECK_CONDITION status to the
2334 	 * Initiator Port.
2335 	 */
2336 	spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2337 	while (!list_empty(&lun->lun_cmd_list)) {
2338 		cmd = list_first_entry(&lun->lun_cmd_list,
2339 		       struct se_cmd, se_lun_node);
2340 		list_del_init(&cmd->se_lun_node);
2341 
2342 		spin_lock(&cmd->t_state_lock);
2343 		pr_debug("SE_LUN[%d] - Setting cmd->transport"
2344 			"_lun_stop for  ITT: 0x%08x\n",
2345 			cmd->se_lun->unpacked_lun,
2346 			cmd->se_tfo->get_task_tag(cmd));
2347 		cmd->transport_state |= CMD_T_LUN_STOP;
2348 		spin_unlock(&cmd->t_state_lock);
2349 
2350 		spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
2351 
2352 		if (!cmd->se_lun) {
2353 			pr_err("ITT: 0x%08x, [i,t]_state: %u/%u\n",
2354 				cmd->se_tfo->get_task_tag(cmd),
2355 				cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2356 			BUG();
2357 		}
2358 		/*
2359 		 * If the Storage engine still owns the iscsi_cmd_t, determine
2360 		 * and/or stop its context.
2361 		 */
2362 		pr_debug("SE_LUN[%d] - ITT: 0x%08x before transport"
2363 			"_lun_wait_for_tasks()\n", cmd->se_lun->unpacked_lun,
2364 			cmd->se_tfo->get_task_tag(cmd));
2365 
2366 		if (transport_lun_wait_for_tasks(cmd, cmd->se_lun) < 0) {
2367 			spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2368 			continue;
2369 		}
2370 
2371 		pr_debug("SE_LUN[%d] - ITT: 0x%08x after transport_lun"
2372 			"_wait_for_tasks(): SUCCESS\n",
2373 			cmd->se_lun->unpacked_lun,
2374 			cmd->se_tfo->get_task_tag(cmd));
2375 
2376 		spin_lock_irqsave(&cmd->t_state_lock, cmd_flags);
2377 		if (!(cmd->transport_state & CMD_T_DEV_ACTIVE)) {
2378 			spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2379 			goto check_cond;
2380 		}
2381 		cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
2382 		target_remove_from_state_list(cmd);
2383 		spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2384 
2385 		/*
2386 		 * The Storage engine stopped this struct se_cmd before it was
2387 		 * send to the fabric frontend for delivery back to the
2388 		 * Initiator Node.  Return this SCSI CDB back with an
2389 		 * CHECK_CONDITION status.
2390 		 */
2391 check_cond:
2392 		transport_send_check_condition_and_sense(cmd,
2393 				TCM_NON_EXISTENT_LUN, 0);
2394 		/*
2395 		 *  If the fabric frontend is waiting for this iscsi_cmd_t to
2396 		 * be released, notify the waiting thread now that LU has
2397 		 * finished accessing it.
2398 		 */
2399 		spin_lock_irqsave(&cmd->t_state_lock, cmd_flags);
2400 		if (cmd->transport_state & CMD_T_LUN_FE_STOP) {
2401 			pr_debug("SE_LUN[%d] - Detected FE stop for"
2402 				" struct se_cmd: %p ITT: 0x%08x\n",
2403 				lun->unpacked_lun,
2404 				cmd, cmd->se_tfo->get_task_tag(cmd));
2405 
2406 			spin_unlock_irqrestore(&cmd->t_state_lock,
2407 					cmd_flags);
2408 			transport_cmd_check_stop(cmd, false, false);
2409 			complete(&cmd->transport_lun_fe_stop_comp);
2410 			spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2411 			continue;
2412 		}
2413 		pr_debug("SE_LUN[%d] - ITT: 0x%08x finished processing\n",
2414 			lun->unpacked_lun, cmd->se_tfo->get_task_tag(cmd));
2415 
2416 		spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2417 		spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2418 	}
2419 	spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
2420 }
2421 
2422 static int transport_clear_lun_thread(void *p)
2423 {
2424 	struct se_lun *lun = p;
2425 
2426 	__transport_clear_lun_from_sessions(lun);
2427 	complete(&lun->lun_shutdown_comp);
2428 
2429 	return 0;
2430 }
2431 
2432 int transport_clear_lun_from_sessions(struct se_lun *lun)
2433 {
2434 	struct task_struct *kt;
2435 
2436 	kt = kthread_run(transport_clear_lun_thread, lun,
2437 			"tcm_cl_%u", lun->unpacked_lun);
2438 	if (IS_ERR(kt)) {
2439 		pr_err("Unable to start clear_lun thread\n");
2440 		return PTR_ERR(kt);
2441 	}
2442 	wait_for_completion(&lun->lun_shutdown_comp);
2443 
2444 	return 0;
2445 }
2446 
2447 /**
2448  * transport_wait_for_tasks - wait for completion to occur
2449  * @cmd:	command to wait
2450  *
2451  * Called from frontend fabric context to wait for storage engine
2452  * to pause and/or release frontend generated struct se_cmd.
2453  */
2454 bool transport_wait_for_tasks(struct se_cmd *cmd)
2455 {
2456 	unsigned long flags;
2457 
2458 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2459 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2460 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2461 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2462 		return false;
2463 	}
2464 
2465 	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2466 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2467 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2468 		return false;
2469 	}
2470 	/*
2471 	 * If we are already stopped due to an external event (ie: LUN shutdown)
2472 	 * sleep until the connection can have the passed struct se_cmd back.
2473 	 * The cmd->transport_lun_stopped_sem will be upped by
2474 	 * transport_clear_lun_from_sessions() once the ConfigFS context caller
2475 	 * has completed its operation on the struct se_cmd.
2476 	 */
2477 	if (cmd->transport_state & CMD_T_LUN_STOP) {
2478 		pr_debug("wait_for_tasks: Stopping"
2479 			" wait_for_completion(&cmd->t_tasktransport_lun_fe"
2480 			"_stop_comp); for ITT: 0x%08x\n",
2481 			cmd->se_tfo->get_task_tag(cmd));
2482 		/*
2483 		 * There is a special case for WRITES where a FE exception +
2484 		 * LUN shutdown means ConfigFS context is still sleeping on
2485 		 * transport_lun_stop_comp in transport_lun_wait_for_tasks().
2486 		 * We go ahead and up transport_lun_stop_comp just to be sure
2487 		 * here.
2488 		 */
2489 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2490 		complete(&cmd->transport_lun_stop_comp);
2491 		wait_for_completion(&cmd->transport_lun_fe_stop_comp);
2492 		spin_lock_irqsave(&cmd->t_state_lock, flags);
2493 
2494 		target_remove_from_state_list(cmd);
2495 		/*
2496 		 * At this point, the frontend who was the originator of this
2497 		 * struct se_cmd, now owns the structure and can be released through
2498 		 * normal means below.
2499 		 */
2500 		pr_debug("wait_for_tasks: Stopped"
2501 			" wait_for_completion(&cmd->t_tasktransport_lun_fe_"
2502 			"stop_comp); for ITT: 0x%08x\n",
2503 			cmd->se_tfo->get_task_tag(cmd));
2504 
2505 		cmd->transport_state &= ~CMD_T_LUN_STOP;
2506 	}
2507 
2508 	if (!(cmd->transport_state & CMD_T_ACTIVE)) {
2509 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2510 		return false;
2511 	}
2512 
2513 	cmd->transport_state |= CMD_T_STOP;
2514 
2515 	pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
2516 		" i_state: %d, t_state: %d, CMD_T_STOP\n",
2517 		cmd, cmd->se_tfo->get_task_tag(cmd),
2518 		cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2519 
2520 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2521 
2522 	wait_for_completion(&cmd->t_transport_stop_comp);
2523 
2524 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2525 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2526 
2527 	pr_debug("wait_for_tasks: Stopped wait_for_completion("
2528 		"&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
2529 		cmd->se_tfo->get_task_tag(cmd));
2530 
2531 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2532 
2533 	return true;
2534 }
2535 EXPORT_SYMBOL(transport_wait_for_tasks);
2536 
2537 static int transport_get_sense_codes(
2538 	struct se_cmd *cmd,
2539 	u8 *asc,
2540 	u8 *ascq)
2541 {
2542 	*asc = cmd->scsi_asc;
2543 	*ascq = cmd->scsi_ascq;
2544 
2545 	return 0;
2546 }
2547 
2548 int
2549 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2550 		sense_reason_t reason, int from_transport)
2551 {
2552 	unsigned char *buffer = cmd->sense_buffer;
2553 	unsigned long flags;
2554 	u8 asc = 0, ascq = 0;
2555 
2556 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2557 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2558 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2559 		return 0;
2560 	}
2561 	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2562 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2563 
2564 	if (!reason && from_transport)
2565 		goto after_reason;
2566 
2567 	if (!from_transport)
2568 		cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2569 
2570 	/*
2571 	 * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
2572 	 * SENSE KEY values from include/scsi/scsi.h
2573 	 */
2574 	switch (reason) {
2575 	case TCM_NO_SENSE:
2576 		/* CURRENT ERROR */
2577 		buffer[0] = 0x70;
2578 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2579 		/* Not Ready */
2580 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2581 		/* NO ADDITIONAL SENSE INFORMATION */
2582 		buffer[SPC_ASC_KEY_OFFSET] = 0;
2583 		buffer[SPC_ASCQ_KEY_OFFSET] = 0;
2584 		break;
2585 	case TCM_NON_EXISTENT_LUN:
2586 		/* CURRENT ERROR */
2587 		buffer[0] = 0x70;
2588 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2589 		/* ILLEGAL REQUEST */
2590 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2591 		/* LOGICAL UNIT NOT SUPPORTED */
2592 		buffer[SPC_ASC_KEY_OFFSET] = 0x25;
2593 		break;
2594 	case TCM_UNSUPPORTED_SCSI_OPCODE:
2595 	case TCM_SECTOR_COUNT_TOO_MANY:
2596 		/* CURRENT ERROR */
2597 		buffer[0] = 0x70;
2598 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2599 		/* ILLEGAL REQUEST */
2600 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2601 		/* INVALID COMMAND OPERATION CODE */
2602 		buffer[SPC_ASC_KEY_OFFSET] = 0x20;
2603 		break;
2604 	case TCM_UNKNOWN_MODE_PAGE:
2605 		/* CURRENT ERROR */
2606 		buffer[0] = 0x70;
2607 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2608 		/* ILLEGAL REQUEST */
2609 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2610 		/* INVALID FIELD IN CDB */
2611 		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2612 		break;
2613 	case TCM_CHECK_CONDITION_ABORT_CMD:
2614 		/* CURRENT ERROR */
2615 		buffer[0] = 0x70;
2616 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2617 		/* ABORTED COMMAND */
2618 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2619 		/* BUS DEVICE RESET FUNCTION OCCURRED */
2620 		buffer[SPC_ASC_KEY_OFFSET] = 0x29;
2621 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2622 		break;
2623 	case TCM_INCORRECT_AMOUNT_OF_DATA:
2624 		/* CURRENT ERROR */
2625 		buffer[0] = 0x70;
2626 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2627 		/* ABORTED COMMAND */
2628 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2629 		/* WRITE ERROR */
2630 		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2631 		/* NOT ENOUGH UNSOLICITED DATA */
2632 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0d;
2633 		break;
2634 	case TCM_INVALID_CDB_FIELD:
2635 		/* CURRENT ERROR */
2636 		buffer[0] = 0x70;
2637 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2638 		/* ILLEGAL REQUEST */
2639 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2640 		/* INVALID FIELD IN CDB */
2641 		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2642 		break;
2643 	case TCM_INVALID_PARAMETER_LIST:
2644 		/* CURRENT ERROR */
2645 		buffer[0] = 0x70;
2646 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2647 		/* ILLEGAL REQUEST */
2648 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2649 		/* INVALID FIELD IN PARAMETER LIST */
2650 		buffer[SPC_ASC_KEY_OFFSET] = 0x26;
2651 		break;
2652 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
2653 		/* CURRENT ERROR */
2654 		buffer[0] = 0x70;
2655 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2656 		/* ILLEGAL REQUEST */
2657 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2658 		/* PARAMETER LIST LENGTH ERROR */
2659 		buffer[SPC_ASC_KEY_OFFSET] = 0x1a;
2660 		break;
2661 	case TCM_UNEXPECTED_UNSOLICITED_DATA:
2662 		/* CURRENT ERROR */
2663 		buffer[0] = 0x70;
2664 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2665 		/* ABORTED COMMAND */
2666 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2667 		/* WRITE ERROR */
2668 		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2669 		/* UNEXPECTED_UNSOLICITED_DATA */
2670 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0c;
2671 		break;
2672 	case TCM_SERVICE_CRC_ERROR:
2673 		/* CURRENT ERROR */
2674 		buffer[0] = 0x70;
2675 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2676 		/* ABORTED COMMAND */
2677 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2678 		/* PROTOCOL SERVICE CRC ERROR */
2679 		buffer[SPC_ASC_KEY_OFFSET] = 0x47;
2680 		/* N/A */
2681 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x05;
2682 		break;
2683 	case TCM_SNACK_REJECTED:
2684 		/* CURRENT ERROR */
2685 		buffer[0] = 0x70;
2686 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2687 		/* ABORTED COMMAND */
2688 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2689 		/* READ ERROR */
2690 		buffer[SPC_ASC_KEY_OFFSET] = 0x11;
2691 		/* FAILED RETRANSMISSION REQUEST */
2692 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x13;
2693 		break;
2694 	case TCM_WRITE_PROTECTED:
2695 		/* CURRENT ERROR */
2696 		buffer[0] = 0x70;
2697 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2698 		/* DATA PROTECT */
2699 		buffer[SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
2700 		/* WRITE PROTECTED */
2701 		buffer[SPC_ASC_KEY_OFFSET] = 0x27;
2702 		break;
2703 	case TCM_ADDRESS_OUT_OF_RANGE:
2704 		/* CURRENT ERROR */
2705 		buffer[0] = 0x70;
2706 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2707 		/* ILLEGAL REQUEST */
2708 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2709 		/* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2710 		buffer[SPC_ASC_KEY_OFFSET] = 0x21;
2711 		break;
2712 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2713 		/* CURRENT ERROR */
2714 		buffer[0] = 0x70;
2715 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2716 		/* UNIT ATTENTION */
2717 		buffer[SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
2718 		core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2719 		buffer[SPC_ASC_KEY_OFFSET] = asc;
2720 		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2721 		break;
2722 	case TCM_CHECK_CONDITION_NOT_READY:
2723 		/* CURRENT ERROR */
2724 		buffer[0] = 0x70;
2725 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2726 		/* Not Ready */
2727 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2728 		transport_get_sense_codes(cmd, &asc, &ascq);
2729 		buffer[SPC_ASC_KEY_OFFSET] = asc;
2730 		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2731 		break;
2732 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
2733 	default:
2734 		/* CURRENT ERROR */
2735 		buffer[0] = 0x70;
2736 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2737 		/*
2738 		 * Returning ILLEGAL REQUEST would cause immediate IO errors on
2739 		 * Solaris initiators.  Returning NOT READY instead means the
2740 		 * operations will be retried a finite number of times and we
2741 		 * can survive intermittent errors.
2742 		 */
2743 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2744 		/* LOGICAL UNIT COMMUNICATION FAILURE */
2745 		buffer[SPC_ASC_KEY_OFFSET] = 0x08;
2746 		break;
2747 	}
2748 	/*
2749 	 * This code uses linux/include/scsi/scsi.h SAM status codes!
2750 	 */
2751 	cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2752 	/*
2753 	 * Automatically padded, this value is encoded in the fabric's
2754 	 * data_length response PDU containing the SCSI defined sense data.
2755 	 */
2756 	cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2757 
2758 after_reason:
2759 	trace_target_cmd_complete(cmd);
2760 	return cmd->se_tfo->queue_status(cmd);
2761 }
2762 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2763 
2764 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2765 {
2766 	if (!(cmd->transport_state & CMD_T_ABORTED))
2767 		return 0;
2768 
2769 	if (!send_status || (cmd->se_cmd_flags & SCF_SENT_DELAYED_TAS))
2770 		return 1;
2771 
2772 	pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08x\n",
2773 		 cmd->t_task_cdb[0], cmd->se_tfo->get_task_tag(cmd));
2774 
2775 	cmd->se_cmd_flags |= SCF_SENT_DELAYED_TAS;
2776 	trace_target_cmd_complete(cmd);
2777 	cmd->se_tfo->queue_status(cmd);
2778 
2779 	return 1;
2780 }
2781 EXPORT_SYMBOL(transport_check_aborted_status);
2782 
2783 void transport_send_task_abort(struct se_cmd *cmd)
2784 {
2785 	unsigned long flags;
2786 
2787 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2788 	if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION | SCF_SENT_DELAYED_TAS)) {
2789 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2790 		return;
2791 	}
2792 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2793 
2794 	/*
2795 	 * If there are still expected incoming fabric WRITEs, we wait
2796 	 * until until they have completed before sending a TASK_ABORTED
2797 	 * response.  This response with TASK_ABORTED status will be
2798 	 * queued back to fabric module by transport_check_aborted_status().
2799 	 */
2800 	if (cmd->data_direction == DMA_TO_DEVICE) {
2801 		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
2802 			cmd->transport_state |= CMD_T_ABORTED;
2803 			smp_mb__after_atomic_inc();
2804 		}
2805 	}
2806 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2807 
2808 	transport_lun_remove_cmd(cmd);
2809 
2810 	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
2811 		" ITT: 0x%08x\n", cmd->t_task_cdb[0],
2812 		cmd->se_tfo->get_task_tag(cmd));
2813 
2814 	trace_target_cmd_complete(cmd);
2815 	cmd->se_tfo->queue_status(cmd);
2816 }
2817 
2818 static void target_tmr_work(struct work_struct *work)
2819 {
2820 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2821 	struct se_device *dev = cmd->se_dev;
2822 	struct se_tmr_req *tmr = cmd->se_tmr_req;
2823 	int ret;
2824 
2825 	switch (tmr->function) {
2826 	case TMR_ABORT_TASK:
2827 		core_tmr_abort_task(dev, tmr, cmd->se_sess);
2828 		break;
2829 	case TMR_ABORT_TASK_SET:
2830 	case TMR_CLEAR_ACA:
2831 	case TMR_CLEAR_TASK_SET:
2832 		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
2833 		break;
2834 	case TMR_LUN_RESET:
2835 		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
2836 		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
2837 					 TMR_FUNCTION_REJECTED;
2838 		break;
2839 	case TMR_TARGET_WARM_RESET:
2840 		tmr->response = TMR_FUNCTION_REJECTED;
2841 		break;
2842 	case TMR_TARGET_COLD_RESET:
2843 		tmr->response = TMR_FUNCTION_REJECTED;
2844 		break;
2845 	default:
2846 		pr_err("Uknown TMR function: 0x%02x.\n",
2847 				tmr->function);
2848 		tmr->response = TMR_FUNCTION_REJECTED;
2849 		break;
2850 	}
2851 
2852 	cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
2853 	cmd->se_tfo->queue_tm_rsp(cmd);
2854 
2855 	transport_cmd_check_stop_to_fabric(cmd);
2856 }
2857 
2858 int transport_generic_handle_tmr(
2859 	struct se_cmd *cmd)
2860 {
2861 	INIT_WORK(&cmd->work, target_tmr_work);
2862 	queue_work(cmd->se_dev->tmr_wq, &cmd->work);
2863 	return 0;
2864 }
2865 EXPORT_SYMBOL(transport_generic_handle_tmr);
2866