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 static struct workqueue_struct *target_completion_wq;
56 static struct kmem_cache *se_sess_cache;
57 struct kmem_cache *se_ua_cache;
58 struct kmem_cache *t10_pr_reg_cache;
59 struct kmem_cache *t10_alua_lu_gp_cache;
60 struct kmem_cache *t10_alua_lu_gp_mem_cache;
61 struct kmem_cache *t10_alua_tg_pt_gp_cache;
62 struct kmem_cache *t10_alua_tg_pt_gp_mem_cache;
63 
64 static void transport_complete_task_attr(struct se_cmd *cmd);
65 static void transport_handle_queue_full(struct se_cmd *cmd,
66 		struct se_device *dev);
67 static int transport_generic_get_mem(struct se_cmd *cmd);
68 static int transport_put_cmd(struct se_cmd *cmd);
69 static void target_complete_ok_work(struct work_struct *work);
70 
71 int init_se_kmem_caches(void)
72 {
73 	se_sess_cache = kmem_cache_create("se_sess_cache",
74 			sizeof(struct se_session), __alignof__(struct se_session),
75 			0, NULL);
76 	if (!se_sess_cache) {
77 		pr_err("kmem_cache_create() for struct se_session"
78 				" failed\n");
79 		goto out;
80 	}
81 	se_ua_cache = kmem_cache_create("se_ua_cache",
82 			sizeof(struct se_ua), __alignof__(struct se_ua),
83 			0, NULL);
84 	if (!se_ua_cache) {
85 		pr_err("kmem_cache_create() for struct se_ua failed\n");
86 		goto out_free_sess_cache;
87 	}
88 	t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
89 			sizeof(struct t10_pr_registration),
90 			__alignof__(struct t10_pr_registration), 0, NULL);
91 	if (!t10_pr_reg_cache) {
92 		pr_err("kmem_cache_create() for struct t10_pr_registration"
93 				" failed\n");
94 		goto out_free_ua_cache;
95 	}
96 	t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
97 			sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
98 			0, NULL);
99 	if (!t10_alua_lu_gp_cache) {
100 		pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
101 				" failed\n");
102 		goto out_free_pr_reg_cache;
103 	}
104 	t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
105 			sizeof(struct t10_alua_lu_gp_member),
106 			__alignof__(struct t10_alua_lu_gp_member), 0, NULL);
107 	if (!t10_alua_lu_gp_mem_cache) {
108 		pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
109 				"cache failed\n");
110 		goto out_free_lu_gp_cache;
111 	}
112 	t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
113 			sizeof(struct t10_alua_tg_pt_gp),
114 			__alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
115 	if (!t10_alua_tg_pt_gp_cache) {
116 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
117 				"cache failed\n");
118 		goto out_free_lu_gp_mem_cache;
119 	}
120 	t10_alua_tg_pt_gp_mem_cache = kmem_cache_create(
121 			"t10_alua_tg_pt_gp_mem_cache",
122 			sizeof(struct t10_alua_tg_pt_gp_member),
123 			__alignof__(struct t10_alua_tg_pt_gp_member),
124 			0, NULL);
125 	if (!t10_alua_tg_pt_gp_mem_cache) {
126 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
127 				"mem_t failed\n");
128 		goto out_free_tg_pt_gp_cache;
129 	}
130 
131 	target_completion_wq = alloc_workqueue("target_completion",
132 					       WQ_MEM_RECLAIM, 0);
133 	if (!target_completion_wq)
134 		goto out_free_tg_pt_gp_mem_cache;
135 
136 	return 0;
137 
138 out_free_tg_pt_gp_mem_cache:
139 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
140 out_free_tg_pt_gp_cache:
141 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
142 out_free_lu_gp_mem_cache:
143 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
144 out_free_lu_gp_cache:
145 	kmem_cache_destroy(t10_alua_lu_gp_cache);
146 out_free_pr_reg_cache:
147 	kmem_cache_destroy(t10_pr_reg_cache);
148 out_free_ua_cache:
149 	kmem_cache_destroy(se_ua_cache);
150 out_free_sess_cache:
151 	kmem_cache_destroy(se_sess_cache);
152 out:
153 	return -ENOMEM;
154 }
155 
156 void release_se_kmem_caches(void)
157 {
158 	destroy_workqueue(target_completion_wq);
159 	kmem_cache_destroy(se_sess_cache);
160 	kmem_cache_destroy(se_ua_cache);
161 	kmem_cache_destroy(t10_pr_reg_cache);
162 	kmem_cache_destroy(t10_alua_lu_gp_cache);
163 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
164 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
165 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
166 }
167 
168 /* This code ensures unique mib indexes are handed out. */
169 static DEFINE_SPINLOCK(scsi_mib_index_lock);
170 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
171 
172 /*
173  * Allocate a new row index for the entry type specified
174  */
175 u32 scsi_get_new_index(scsi_index_t type)
176 {
177 	u32 new_index;
178 
179 	BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
180 
181 	spin_lock(&scsi_mib_index_lock);
182 	new_index = ++scsi_mib_index[type];
183 	spin_unlock(&scsi_mib_index_lock);
184 
185 	return new_index;
186 }
187 
188 void transport_subsystem_check_init(void)
189 {
190 	int ret;
191 	static int sub_api_initialized;
192 
193 	if (sub_api_initialized)
194 		return;
195 
196 	ret = request_module("target_core_iblock");
197 	if (ret != 0)
198 		pr_err("Unable to load target_core_iblock\n");
199 
200 	ret = request_module("target_core_file");
201 	if (ret != 0)
202 		pr_err("Unable to load target_core_file\n");
203 
204 	ret = request_module("target_core_pscsi");
205 	if (ret != 0)
206 		pr_err("Unable to load target_core_pscsi\n");
207 
208 	sub_api_initialized = 1;
209 }
210 
211 struct se_session *transport_init_session(void)
212 {
213 	struct se_session *se_sess;
214 
215 	se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
216 	if (!se_sess) {
217 		pr_err("Unable to allocate struct se_session from"
218 				" se_sess_cache\n");
219 		return ERR_PTR(-ENOMEM);
220 	}
221 	INIT_LIST_HEAD(&se_sess->sess_list);
222 	INIT_LIST_HEAD(&se_sess->sess_acl_list);
223 	INIT_LIST_HEAD(&se_sess->sess_cmd_list);
224 	INIT_LIST_HEAD(&se_sess->sess_wait_list);
225 	spin_lock_init(&se_sess->sess_cmd_lock);
226 	kref_init(&se_sess->sess_kref);
227 
228 	return se_sess;
229 }
230 EXPORT_SYMBOL(transport_init_session);
231 
232 /*
233  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
234  */
235 void __transport_register_session(
236 	struct se_portal_group *se_tpg,
237 	struct se_node_acl *se_nacl,
238 	struct se_session *se_sess,
239 	void *fabric_sess_ptr)
240 {
241 	unsigned char buf[PR_REG_ISID_LEN];
242 
243 	se_sess->se_tpg = se_tpg;
244 	se_sess->fabric_sess_ptr = fabric_sess_ptr;
245 	/*
246 	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
247 	 *
248 	 * Only set for struct se_session's that will actually be moving I/O.
249 	 * eg: *NOT* discovery sessions.
250 	 */
251 	if (se_nacl) {
252 		/*
253 		 * If the fabric module supports an ISID based TransportID,
254 		 * save this value in binary from the fabric I_T Nexus now.
255 		 */
256 		if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
257 			memset(&buf[0], 0, PR_REG_ISID_LEN);
258 			se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
259 					&buf[0], PR_REG_ISID_LEN);
260 			se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
261 		}
262 		kref_get(&se_nacl->acl_kref);
263 
264 		spin_lock_irq(&se_nacl->nacl_sess_lock);
265 		/*
266 		 * The se_nacl->nacl_sess pointer will be set to the
267 		 * last active I_T Nexus for each struct se_node_acl.
268 		 */
269 		se_nacl->nacl_sess = se_sess;
270 
271 		list_add_tail(&se_sess->sess_acl_list,
272 			      &se_nacl->acl_sess_list);
273 		spin_unlock_irq(&se_nacl->nacl_sess_lock);
274 	}
275 	list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
276 
277 	pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
278 		se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
279 }
280 EXPORT_SYMBOL(__transport_register_session);
281 
282 void transport_register_session(
283 	struct se_portal_group *se_tpg,
284 	struct se_node_acl *se_nacl,
285 	struct se_session *se_sess,
286 	void *fabric_sess_ptr)
287 {
288 	unsigned long flags;
289 
290 	spin_lock_irqsave(&se_tpg->session_lock, flags);
291 	__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
292 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
293 }
294 EXPORT_SYMBOL(transport_register_session);
295 
296 static void target_release_session(struct kref *kref)
297 {
298 	struct se_session *se_sess = container_of(kref,
299 			struct se_session, sess_kref);
300 	struct se_portal_group *se_tpg = se_sess->se_tpg;
301 
302 	se_tpg->se_tpg_tfo->close_session(se_sess);
303 }
304 
305 void target_get_session(struct se_session *se_sess)
306 {
307 	kref_get(&se_sess->sess_kref);
308 }
309 EXPORT_SYMBOL(target_get_session);
310 
311 void target_put_session(struct se_session *se_sess)
312 {
313 	struct se_portal_group *tpg = se_sess->se_tpg;
314 
315 	if (tpg->se_tpg_tfo->put_session != NULL) {
316 		tpg->se_tpg_tfo->put_session(se_sess);
317 		return;
318 	}
319 	kref_put(&se_sess->sess_kref, target_release_session);
320 }
321 EXPORT_SYMBOL(target_put_session);
322 
323 static void target_complete_nacl(struct kref *kref)
324 {
325 	struct se_node_acl *nacl = container_of(kref,
326 				struct se_node_acl, acl_kref);
327 
328 	complete(&nacl->acl_free_comp);
329 }
330 
331 void target_put_nacl(struct se_node_acl *nacl)
332 {
333 	kref_put(&nacl->acl_kref, target_complete_nacl);
334 }
335 
336 void transport_deregister_session_configfs(struct se_session *se_sess)
337 {
338 	struct se_node_acl *se_nacl;
339 	unsigned long flags;
340 	/*
341 	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
342 	 */
343 	se_nacl = se_sess->se_node_acl;
344 	if (se_nacl) {
345 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
346 		if (se_nacl->acl_stop == 0)
347 			list_del(&se_sess->sess_acl_list);
348 		/*
349 		 * If the session list is empty, then clear the pointer.
350 		 * Otherwise, set the struct se_session pointer from the tail
351 		 * element of the per struct se_node_acl active session list.
352 		 */
353 		if (list_empty(&se_nacl->acl_sess_list))
354 			se_nacl->nacl_sess = NULL;
355 		else {
356 			se_nacl->nacl_sess = container_of(
357 					se_nacl->acl_sess_list.prev,
358 					struct se_session, sess_acl_list);
359 		}
360 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
361 	}
362 }
363 EXPORT_SYMBOL(transport_deregister_session_configfs);
364 
365 void transport_free_session(struct se_session *se_sess)
366 {
367 	kmem_cache_free(se_sess_cache, se_sess);
368 }
369 EXPORT_SYMBOL(transport_free_session);
370 
371 void transport_deregister_session(struct se_session *se_sess)
372 {
373 	struct se_portal_group *se_tpg = se_sess->se_tpg;
374 	struct target_core_fabric_ops *se_tfo;
375 	struct se_node_acl *se_nacl;
376 	unsigned long flags;
377 	bool comp_nacl = true;
378 
379 	if (!se_tpg) {
380 		transport_free_session(se_sess);
381 		return;
382 	}
383 	se_tfo = se_tpg->se_tpg_tfo;
384 
385 	spin_lock_irqsave(&se_tpg->session_lock, flags);
386 	list_del(&se_sess->sess_list);
387 	se_sess->se_tpg = NULL;
388 	se_sess->fabric_sess_ptr = NULL;
389 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
390 
391 	/*
392 	 * Determine if we need to do extra work for this initiator node's
393 	 * struct se_node_acl if it had been previously dynamically generated.
394 	 */
395 	se_nacl = se_sess->se_node_acl;
396 
397 	spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
398 	if (se_nacl && se_nacl->dynamic_node_acl) {
399 		if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
400 			list_del(&se_nacl->acl_list);
401 			se_tpg->num_node_acls--;
402 			spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
403 			core_tpg_wait_for_nacl_pr_ref(se_nacl);
404 			core_free_device_list_for_node(se_nacl, se_tpg);
405 			se_tfo->tpg_release_fabric_acl(se_tpg, se_nacl);
406 
407 			comp_nacl = false;
408 			spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
409 		}
410 	}
411 	spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
412 
413 	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
414 		se_tpg->se_tpg_tfo->get_fabric_name());
415 	/*
416 	 * If last kref is dropping now for an explict NodeACL, awake sleeping
417 	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
418 	 * removal context.
419 	 */
420 	if (se_nacl && comp_nacl == true)
421 		target_put_nacl(se_nacl);
422 
423 	transport_free_session(se_sess);
424 }
425 EXPORT_SYMBOL(transport_deregister_session);
426 
427 /*
428  * Called with cmd->t_state_lock held.
429  */
430 static void target_remove_from_state_list(struct se_cmd *cmd)
431 {
432 	struct se_device *dev = cmd->se_dev;
433 	unsigned long flags;
434 
435 	if (!dev)
436 		return;
437 
438 	if (cmd->transport_state & CMD_T_BUSY)
439 		return;
440 
441 	spin_lock_irqsave(&dev->execute_task_lock, flags);
442 	if (cmd->state_active) {
443 		list_del(&cmd->state_list);
444 		cmd->state_active = false;
445 	}
446 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
447 }
448 
449 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists)
450 {
451 	unsigned long flags;
452 
453 	spin_lock_irqsave(&cmd->t_state_lock, flags);
454 	/*
455 	 * Determine if IOCTL context caller in requesting the stopping of this
456 	 * command for LUN shutdown purposes.
457 	 */
458 	if (cmd->transport_state & CMD_T_LUN_STOP) {
459 		pr_debug("%s:%d CMD_T_LUN_STOP for ITT: 0x%08x\n",
460 			__func__, __LINE__, cmd->se_tfo->get_task_tag(cmd));
461 
462 		cmd->transport_state &= ~CMD_T_ACTIVE;
463 		if (remove_from_lists)
464 			target_remove_from_state_list(cmd);
465 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
466 
467 		complete(&cmd->transport_lun_stop_comp);
468 		return 1;
469 	}
470 
471 	if (remove_from_lists) {
472 		target_remove_from_state_list(cmd);
473 
474 		/*
475 		 * Clear struct se_cmd->se_lun before the handoff to FE.
476 		 */
477 		cmd->se_lun = NULL;
478 	}
479 
480 	/*
481 	 * Determine if frontend context caller is requesting the stopping of
482 	 * this command for frontend exceptions.
483 	 */
484 	if (cmd->transport_state & CMD_T_STOP) {
485 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
486 			__func__, __LINE__,
487 			cmd->se_tfo->get_task_tag(cmd));
488 
489 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
490 
491 		complete(&cmd->t_transport_stop_comp);
492 		return 1;
493 	}
494 
495 	cmd->transport_state &= ~CMD_T_ACTIVE;
496 	if (remove_from_lists) {
497 		/*
498 		 * Some fabric modules like tcm_loop can release
499 		 * their internally allocated I/O reference now and
500 		 * struct se_cmd now.
501 		 *
502 		 * Fabric modules are expected to return '1' here if the
503 		 * se_cmd being passed is released at this point,
504 		 * or zero if not being released.
505 		 */
506 		if (cmd->se_tfo->check_stop_free != NULL) {
507 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
508 			return cmd->se_tfo->check_stop_free(cmd);
509 		}
510 	}
511 
512 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
513 	return 0;
514 }
515 
516 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
517 {
518 	return transport_cmd_check_stop(cmd, true);
519 }
520 
521 static void transport_lun_remove_cmd(struct se_cmd *cmd)
522 {
523 	struct se_lun *lun = cmd->se_lun;
524 	unsigned long flags;
525 
526 	if (!lun)
527 		return;
528 
529 	spin_lock_irqsave(&cmd->t_state_lock, flags);
530 	if (cmd->transport_state & CMD_T_DEV_ACTIVE) {
531 		cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
532 		target_remove_from_state_list(cmd);
533 	}
534 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
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 	unsigned long flags;
1096 	sense_reason_t ret;
1097 
1098 	/*
1099 	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1100 	 * for VARIABLE_LENGTH_CMD
1101 	 */
1102 	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1103 		pr_err("Received SCSI CDB with command_size: %d that"
1104 			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1105 			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1106 		return TCM_INVALID_CDB_FIELD;
1107 	}
1108 	/*
1109 	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1110 	 * allocate the additional extended CDB buffer now..  Otherwise
1111 	 * setup the pointer from __t_task_cdb to t_task_cdb.
1112 	 */
1113 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1114 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1115 						GFP_KERNEL);
1116 		if (!cmd->t_task_cdb) {
1117 			pr_err("Unable to allocate cmd->t_task_cdb"
1118 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1119 				scsi_command_size(cdb),
1120 				(unsigned long)sizeof(cmd->__t_task_cdb));
1121 			return TCM_OUT_OF_RESOURCES;
1122 		}
1123 	} else
1124 		cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1125 	/*
1126 	 * Copy the original CDB into cmd->
1127 	 */
1128 	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1129 
1130 	/*
1131 	 * Check for an existing UNIT ATTENTION condition
1132 	 */
1133 	ret = target_scsi3_ua_check(cmd);
1134 	if (ret)
1135 		return ret;
1136 
1137 	ret = target_alua_state_check(cmd);
1138 	if (ret)
1139 		return ret;
1140 
1141 	ret = target_check_reservation(cmd);
1142 	if (ret) {
1143 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1144 		return ret;
1145 	}
1146 
1147 	ret = dev->transport->parse_cdb(cmd);
1148 	if (ret)
1149 		return ret;
1150 
1151 	ret = transport_check_alloc_task_attr(cmd);
1152 	if (ret)
1153 		return ret;
1154 
1155 	spin_lock_irqsave(&cmd->t_state_lock, flags);
1156 	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1157 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1158 
1159 	spin_lock(&cmd->se_lun->lun_sep_lock);
1160 	if (cmd->se_lun->lun_sep)
1161 		cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
1162 	spin_unlock(&cmd->se_lun->lun_sep_lock);
1163 	return 0;
1164 }
1165 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1166 
1167 /*
1168  * Used by fabric module frontends to queue tasks directly.
1169  * Many only be used from process context only
1170  */
1171 int transport_handle_cdb_direct(
1172 	struct se_cmd *cmd)
1173 {
1174 	sense_reason_t ret;
1175 
1176 	if (!cmd->se_lun) {
1177 		dump_stack();
1178 		pr_err("cmd->se_lun is NULL\n");
1179 		return -EINVAL;
1180 	}
1181 	if (in_interrupt()) {
1182 		dump_stack();
1183 		pr_err("transport_generic_handle_cdb cannot be called"
1184 				" from interrupt context\n");
1185 		return -EINVAL;
1186 	}
1187 	/*
1188 	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1189 	 * outstanding descriptors are handled correctly during shutdown via
1190 	 * transport_wait_for_tasks()
1191 	 *
1192 	 * Also, we don't take cmd->t_state_lock here as we only expect
1193 	 * this to be called for initial descriptor submission.
1194 	 */
1195 	cmd->t_state = TRANSPORT_NEW_CMD;
1196 	cmd->transport_state |= CMD_T_ACTIVE;
1197 
1198 	/*
1199 	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1200 	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1201 	 * and call transport_generic_request_failure() if necessary..
1202 	 */
1203 	ret = transport_generic_new_cmd(cmd);
1204 	if (ret)
1205 		transport_generic_request_failure(cmd, ret);
1206 	return 0;
1207 }
1208 EXPORT_SYMBOL(transport_handle_cdb_direct);
1209 
1210 static sense_reason_t
1211 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1212 		u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1213 {
1214 	if (!sgl || !sgl_count)
1215 		return 0;
1216 
1217 	/*
1218 	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1219 	 * scatterlists already have been set to follow what the fabric
1220 	 * passes for the original expected data transfer length.
1221 	 */
1222 	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1223 		pr_warn("Rejecting SCSI DATA overflow for fabric using"
1224 			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1225 		return TCM_INVALID_CDB_FIELD;
1226 	}
1227 
1228 	cmd->t_data_sg = sgl;
1229 	cmd->t_data_nents = sgl_count;
1230 
1231 	if (sgl_bidi && sgl_bidi_count) {
1232 		cmd->t_bidi_data_sg = sgl_bidi;
1233 		cmd->t_bidi_data_nents = sgl_bidi_count;
1234 	}
1235 	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1236 	return 0;
1237 }
1238 
1239 /*
1240  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1241  * 			 se_cmd + use pre-allocated SGL memory.
1242  *
1243  * @se_cmd: command descriptor to submit
1244  * @se_sess: associated se_sess for endpoint
1245  * @cdb: pointer to SCSI CDB
1246  * @sense: pointer to SCSI sense buffer
1247  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1248  * @data_length: fabric expected data transfer length
1249  * @task_addr: SAM task attribute
1250  * @data_dir: DMA data direction
1251  * @flags: flags for command submission from target_sc_flags_tables
1252  * @sgl: struct scatterlist memory for unidirectional mapping
1253  * @sgl_count: scatterlist count for unidirectional mapping
1254  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1255  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1256  *
1257  * Returns non zero to signal active I/O shutdown failure.  All other
1258  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1259  * but still return zero here.
1260  *
1261  * This may only be called from process context, and also currently
1262  * assumes internal allocation of fabric payload buffer by target-core.
1263  */
1264 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1265 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1266 		u32 data_length, int task_attr, int data_dir, int flags,
1267 		struct scatterlist *sgl, u32 sgl_count,
1268 		struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1269 {
1270 	struct se_portal_group *se_tpg;
1271 	sense_reason_t rc;
1272 	int ret;
1273 
1274 	se_tpg = se_sess->se_tpg;
1275 	BUG_ON(!se_tpg);
1276 	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1277 	BUG_ON(in_interrupt());
1278 	/*
1279 	 * Initialize se_cmd for target operation.  From this point
1280 	 * exceptions are handled by sending exception status via
1281 	 * target_core_fabric_ops->queue_status() callback
1282 	 */
1283 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1284 				data_length, data_dir, task_attr, sense);
1285 	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1286 		se_cmd->unknown_data_length = 1;
1287 	/*
1288 	 * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1289 	 * se_sess->sess_cmd_list.  A second kref_get here is necessary
1290 	 * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1291 	 * kref_put() to happen during fabric packet acknowledgement.
1292 	 */
1293 	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1294 	if (ret)
1295 		return ret;
1296 	/*
1297 	 * Signal bidirectional data payloads to target-core
1298 	 */
1299 	if (flags & TARGET_SCF_BIDI_OP)
1300 		se_cmd->se_cmd_flags |= SCF_BIDI;
1301 	/*
1302 	 * Locate se_lun pointer and attach it to struct se_cmd
1303 	 */
1304 	rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1305 	if (rc) {
1306 		transport_send_check_condition_and_sense(se_cmd, rc, 0);
1307 		target_put_sess_cmd(se_sess, se_cmd);
1308 		return 0;
1309 	}
1310 
1311 	rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1312 	if (rc != 0) {
1313 		transport_generic_request_failure(se_cmd, rc);
1314 		return 0;
1315 	}
1316 	/*
1317 	 * When a non zero sgl_count has been passed perform SGL passthrough
1318 	 * mapping for pre-allocated fabric memory instead of having target
1319 	 * core perform an internal SGL allocation..
1320 	 */
1321 	if (sgl_count != 0) {
1322 		BUG_ON(!sgl);
1323 
1324 		/*
1325 		 * A work-around for tcm_loop as some userspace code via
1326 		 * scsi-generic do not memset their associated read buffers,
1327 		 * so go ahead and do that here for type non-data CDBs.  Also
1328 		 * note that this is currently guaranteed to be a single SGL
1329 		 * for this case by target core in target_setup_cmd_from_cdb()
1330 		 * -> transport_generic_cmd_sequencer().
1331 		 */
1332 		if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1333 		     se_cmd->data_direction == DMA_FROM_DEVICE) {
1334 			unsigned char *buf = NULL;
1335 
1336 			if (sgl)
1337 				buf = kmap(sg_page(sgl)) + sgl->offset;
1338 
1339 			if (buf) {
1340 				memset(buf, 0, sgl->length);
1341 				kunmap(sg_page(sgl));
1342 			}
1343 		}
1344 
1345 		rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1346 				sgl_bidi, sgl_bidi_count);
1347 		if (rc != 0) {
1348 			transport_generic_request_failure(se_cmd, rc);
1349 			return 0;
1350 		}
1351 	}
1352 	/*
1353 	 * Check if we need to delay processing because of ALUA
1354 	 * Active/NonOptimized primary access state..
1355 	 */
1356 	core_alua_check_nonop_delay(se_cmd);
1357 
1358 	transport_handle_cdb_direct(se_cmd);
1359 	return 0;
1360 }
1361 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1362 
1363 /*
1364  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1365  *
1366  * @se_cmd: command descriptor to submit
1367  * @se_sess: associated se_sess for endpoint
1368  * @cdb: pointer to SCSI CDB
1369  * @sense: pointer to SCSI sense buffer
1370  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1371  * @data_length: fabric expected data transfer length
1372  * @task_addr: SAM task attribute
1373  * @data_dir: DMA data direction
1374  * @flags: flags for command submission from target_sc_flags_tables
1375  *
1376  * Returns non zero to signal active I/O shutdown failure.  All other
1377  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1378  * but still return zero here.
1379  *
1380  * This may only be called from process context, and also currently
1381  * assumes internal allocation of fabric payload buffer by target-core.
1382  *
1383  * It also assumes interal target core SGL memory allocation.
1384  */
1385 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1386 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1387 		u32 data_length, int task_attr, int data_dir, int flags)
1388 {
1389 	return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1390 			unpacked_lun, data_length, task_attr, data_dir,
1391 			flags, NULL, 0, NULL, 0);
1392 }
1393 EXPORT_SYMBOL(target_submit_cmd);
1394 
1395 static void target_complete_tmr_failure(struct work_struct *work)
1396 {
1397 	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1398 
1399 	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1400 	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1401 
1402 	transport_cmd_check_stop_to_fabric(se_cmd);
1403 }
1404 
1405 /**
1406  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1407  *                     for TMR CDBs
1408  *
1409  * @se_cmd: command descriptor to submit
1410  * @se_sess: associated se_sess for endpoint
1411  * @sense: pointer to SCSI sense buffer
1412  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1413  * @fabric_context: fabric context for TMR req
1414  * @tm_type: Type of TM request
1415  * @gfp: gfp type for caller
1416  * @tag: referenced task tag for TMR_ABORT_TASK
1417  * @flags: submit cmd flags
1418  *
1419  * Callable from all contexts.
1420  **/
1421 
1422 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1423 		unsigned char *sense, u32 unpacked_lun,
1424 		void *fabric_tmr_ptr, unsigned char tm_type,
1425 		gfp_t gfp, unsigned int tag, int flags)
1426 {
1427 	struct se_portal_group *se_tpg;
1428 	int ret;
1429 
1430 	se_tpg = se_sess->se_tpg;
1431 	BUG_ON(!se_tpg);
1432 
1433 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1434 			      0, DMA_NONE, MSG_SIMPLE_TAG, sense);
1435 	/*
1436 	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1437 	 * allocation failure.
1438 	 */
1439 	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1440 	if (ret < 0)
1441 		return -ENOMEM;
1442 
1443 	if (tm_type == TMR_ABORT_TASK)
1444 		se_cmd->se_tmr_req->ref_task_tag = tag;
1445 
1446 	/* See target_submit_cmd for commentary */
1447 	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1448 	if (ret) {
1449 		core_tmr_release_req(se_cmd->se_tmr_req);
1450 		return ret;
1451 	}
1452 
1453 	ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1454 	if (ret) {
1455 		/*
1456 		 * For callback during failure handling, push this work off
1457 		 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1458 		 */
1459 		INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1460 		schedule_work(&se_cmd->work);
1461 		return 0;
1462 	}
1463 	transport_generic_handle_tmr(se_cmd);
1464 	return 0;
1465 }
1466 EXPORT_SYMBOL(target_submit_tmr);
1467 
1468 /*
1469  * If the cmd is active, request it to be stopped and sleep until it
1470  * has completed.
1471  */
1472 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1473 {
1474 	bool was_active = false;
1475 
1476 	if (cmd->transport_state & CMD_T_BUSY) {
1477 		cmd->transport_state |= CMD_T_REQUEST_STOP;
1478 		spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1479 
1480 		pr_debug("cmd %p waiting to complete\n", cmd);
1481 		wait_for_completion(&cmd->task_stop_comp);
1482 		pr_debug("cmd %p stopped successfully\n", cmd);
1483 
1484 		spin_lock_irqsave(&cmd->t_state_lock, *flags);
1485 		cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1486 		cmd->transport_state &= ~CMD_T_BUSY;
1487 		was_active = true;
1488 	}
1489 
1490 	return was_active;
1491 }
1492 
1493 /*
1494  * Handle SAM-esque emulation for generic transport request failures.
1495  */
1496 void transport_generic_request_failure(struct se_cmd *cmd,
1497 		sense_reason_t sense_reason)
1498 {
1499 	int ret = 0;
1500 
1501 	pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
1502 		" CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
1503 		cmd->t_task_cdb[0]);
1504 	pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1505 		cmd->se_tfo->get_cmd_state(cmd),
1506 		cmd->t_state, sense_reason);
1507 	pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1508 		(cmd->transport_state & CMD_T_ACTIVE) != 0,
1509 		(cmd->transport_state & CMD_T_STOP) != 0,
1510 		(cmd->transport_state & CMD_T_SENT) != 0);
1511 
1512 	/*
1513 	 * For SAM Task Attribute emulation for failed struct se_cmd
1514 	 */
1515 	transport_complete_task_attr(cmd);
1516 
1517 	switch (sense_reason) {
1518 	case TCM_NON_EXISTENT_LUN:
1519 	case TCM_UNSUPPORTED_SCSI_OPCODE:
1520 	case TCM_INVALID_CDB_FIELD:
1521 	case TCM_INVALID_PARAMETER_LIST:
1522 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
1523 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1524 	case TCM_UNKNOWN_MODE_PAGE:
1525 	case TCM_WRITE_PROTECTED:
1526 	case TCM_ADDRESS_OUT_OF_RANGE:
1527 	case TCM_CHECK_CONDITION_ABORT_CMD:
1528 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1529 	case TCM_CHECK_CONDITION_NOT_READY:
1530 		break;
1531 	case TCM_OUT_OF_RESOURCES:
1532 		sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1533 		break;
1534 	case TCM_RESERVATION_CONFLICT:
1535 		/*
1536 		 * No SENSE Data payload for this case, set SCSI Status
1537 		 * and queue the response to $FABRIC_MOD.
1538 		 *
1539 		 * Uses linux/include/scsi/scsi.h SAM status codes defs
1540 		 */
1541 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1542 		/*
1543 		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1544 		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1545 		 * CONFLICT STATUS.
1546 		 *
1547 		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1548 		 */
1549 		if (cmd->se_sess &&
1550 		    cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2)
1551 			core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
1552 				cmd->orig_fe_lun, 0x2C,
1553 				ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1554 
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 	spin_lock_irq(&cmd->t_state_lock);
1587 	cmd->transport_state |= (CMD_T_BUSY|CMD_T_SENT);
1588 	spin_unlock_irq(&cmd->t_state_lock);
1589 
1590 	if (cmd->execute_cmd) {
1591 		ret = cmd->execute_cmd(cmd);
1592 		if (ret) {
1593 			spin_lock_irq(&cmd->t_state_lock);
1594 			cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1595 			spin_unlock_irq(&cmd->t_state_lock);
1596 
1597 			transport_generic_request_failure(cmd, ret);
1598 		}
1599 	}
1600 }
1601 
1602 static bool target_handle_task_attr(struct se_cmd *cmd)
1603 {
1604 	struct se_device *dev = cmd->se_dev;
1605 
1606 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1607 		return false;
1608 
1609 	/*
1610 	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1611 	 * to allow the passed struct se_cmd list of tasks to the front of the list.
1612 	 */
1613 	switch (cmd->sam_task_attr) {
1614 	case MSG_HEAD_TAG:
1615 		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
1616 			 "se_ordered_id: %u\n",
1617 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1618 		return false;
1619 	case MSG_ORDERED_TAG:
1620 		atomic_inc(&dev->dev_ordered_sync);
1621 		smp_mb__after_atomic_inc();
1622 
1623 		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
1624 			 " se_ordered_id: %u\n",
1625 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1626 
1627 		/*
1628 		 * Execute an ORDERED command if no other older commands
1629 		 * exist that need to be completed first.
1630 		 */
1631 		if (!atomic_read(&dev->simple_cmds))
1632 			return false;
1633 		break;
1634 	default:
1635 		/*
1636 		 * For SIMPLE and UNTAGGED Task Attribute commands
1637 		 */
1638 		atomic_inc(&dev->simple_cmds);
1639 		smp_mb__after_atomic_inc();
1640 		break;
1641 	}
1642 
1643 	if (atomic_read(&dev->dev_ordered_sync) == 0)
1644 		return false;
1645 
1646 	spin_lock(&dev->delayed_cmd_lock);
1647 	list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1648 	spin_unlock(&dev->delayed_cmd_lock);
1649 
1650 	pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
1651 		" delayed CMD list, se_ordered_id: %u\n",
1652 		cmd->t_task_cdb[0], cmd->sam_task_attr,
1653 		cmd->se_ordered_id);
1654 	return true;
1655 }
1656 
1657 void target_execute_cmd(struct se_cmd *cmd)
1658 {
1659 	/*
1660 	 * If the received CDB has aleady been aborted stop processing it here.
1661 	 */
1662 	if (transport_check_aborted_status(cmd, 1)) {
1663 		complete(&cmd->transport_lun_stop_comp);
1664 		return;
1665 	}
1666 
1667 	/*
1668 	 * Determine if IOCTL context caller in requesting the stopping of this
1669 	 * command for LUN shutdown purposes.
1670 	 */
1671 	spin_lock_irq(&cmd->t_state_lock);
1672 	if (cmd->transport_state & CMD_T_LUN_STOP) {
1673 		pr_debug("%s:%d CMD_T_LUN_STOP for ITT: 0x%08x\n",
1674 			__func__, __LINE__, cmd->se_tfo->get_task_tag(cmd));
1675 
1676 		cmd->transport_state &= ~CMD_T_ACTIVE;
1677 		spin_unlock_irq(&cmd->t_state_lock);
1678 		complete(&cmd->transport_lun_stop_comp);
1679 		return;
1680 	}
1681 	/*
1682 	 * Determine if frontend context caller is requesting the stopping of
1683 	 * this command for frontend exceptions.
1684 	 */
1685 	if (cmd->transport_state & CMD_T_STOP) {
1686 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
1687 			__func__, __LINE__,
1688 			cmd->se_tfo->get_task_tag(cmd));
1689 
1690 		spin_unlock_irq(&cmd->t_state_lock);
1691 		complete(&cmd->t_transport_stop_comp);
1692 		return;
1693 	}
1694 
1695 	cmd->t_state = TRANSPORT_PROCESSING;
1696 	cmd->transport_state |= CMD_T_ACTIVE;
1697 	spin_unlock_irq(&cmd->t_state_lock);
1698 
1699 	if (!target_handle_task_attr(cmd))
1700 		__target_execute_cmd(cmd);
1701 }
1702 EXPORT_SYMBOL(target_execute_cmd);
1703 
1704 /*
1705  * Process all commands up to the last received ORDERED task attribute which
1706  * requires another blocking boundary
1707  */
1708 static void target_restart_delayed_cmds(struct se_device *dev)
1709 {
1710 	for (;;) {
1711 		struct se_cmd *cmd;
1712 
1713 		spin_lock(&dev->delayed_cmd_lock);
1714 		if (list_empty(&dev->delayed_cmd_list)) {
1715 			spin_unlock(&dev->delayed_cmd_lock);
1716 			break;
1717 		}
1718 
1719 		cmd = list_entry(dev->delayed_cmd_list.next,
1720 				 struct se_cmd, se_delayed_node);
1721 		list_del(&cmd->se_delayed_node);
1722 		spin_unlock(&dev->delayed_cmd_lock);
1723 
1724 		__target_execute_cmd(cmd);
1725 
1726 		if (cmd->sam_task_attr == MSG_ORDERED_TAG)
1727 			break;
1728 	}
1729 }
1730 
1731 /*
1732  * Called from I/O completion to determine which dormant/delayed
1733  * and ordered cmds need to have their tasks added to the execution queue.
1734  */
1735 static void transport_complete_task_attr(struct se_cmd *cmd)
1736 {
1737 	struct se_device *dev = cmd->se_dev;
1738 
1739 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1740 		return;
1741 
1742 	if (cmd->sam_task_attr == MSG_SIMPLE_TAG) {
1743 		atomic_dec(&dev->simple_cmds);
1744 		smp_mb__after_atomic_dec();
1745 		dev->dev_cur_ordered_id++;
1746 		pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
1747 			" SIMPLE: %u\n", dev->dev_cur_ordered_id,
1748 			cmd->se_ordered_id);
1749 	} else if (cmd->sam_task_attr == MSG_HEAD_TAG) {
1750 		dev->dev_cur_ordered_id++;
1751 		pr_debug("Incremented dev_cur_ordered_id: %u for"
1752 			" HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
1753 			cmd->se_ordered_id);
1754 	} else if (cmd->sam_task_attr == MSG_ORDERED_TAG) {
1755 		atomic_dec(&dev->dev_ordered_sync);
1756 		smp_mb__after_atomic_dec();
1757 
1758 		dev->dev_cur_ordered_id++;
1759 		pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
1760 			" %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
1761 	}
1762 
1763 	target_restart_delayed_cmds(dev);
1764 }
1765 
1766 static void transport_complete_qf(struct se_cmd *cmd)
1767 {
1768 	int ret = 0;
1769 
1770 	transport_complete_task_attr(cmd);
1771 
1772 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1773 		ret = cmd->se_tfo->queue_status(cmd);
1774 		if (ret)
1775 			goto out;
1776 	}
1777 
1778 	switch (cmd->data_direction) {
1779 	case DMA_FROM_DEVICE:
1780 		ret = cmd->se_tfo->queue_data_in(cmd);
1781 		break;
1782 	case DMA_TO_DEVICE:
1783 		if (cmd->t_bidi_data_sg) {
1784 			ret = cmd->se_tfo->queue_data_in(cmd);
1785 			if (ret < 0)
1786 				break;
1787 		}
1788 		/* Fall through for DMA_TO_DEVICE */
1789 	case DMA_NONE:
1790 		ret = cmd->se_tfo->queue_status(cmd);
1791 		break;
1792 	default:
1793 		break;
1794 	}
1795 
1796 out:
1797 	if (ret < 0) {
1798 		transport_handle_queue_full(cmd, cmd->se_dev);
1799 		return;
1800 	}
1801 	transport_lun_remove_cmd(cmd);
1802 	transport_cmd_check_stop_to_fabric(cmd);
1803 }
1804 
1805 static void transport_handle_queue_full(
1806 	struct se_cmd *cmd,
1807 	struct se_device *dev)
1808 {
1809 	spin_lock_irq(&dev->qf_cmd_lock);
1810 	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
1811 	atomic_inc(&dev->dev_qf_count);
1812 	smp_mb__after_atomic_inc();
1813 	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
1814 
1815 	schedule_work(&cmd->se_dev->qf_work_queue);
1816 }
1817 
1818 static void target_complete_ok_work(struct work_struct *work)
1819 {
1820 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
1821 	int ret;
1822 
1823 	/*
1824 	 * Check if we need to move delayed/dormant tasks from cmds on the
1825 	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
1826 	 * Attribute.
1827 	 */
1828 	transport_complete_task_attr(cmd);
1829 
1830 	/*
1831 	 * Check to schedule QUEUE_FULL work, or execute an existing
1832 	 * cmd->transport_qf_callback()
1833 	 */
1834 	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
1835 		schedule_work(&cmd->se_dev->qf_work_queue);
1836 
1837 	/*
1838 	 * Check if we need to send a sense buffer from
1839 	 * the struct se_cmd in question.
1840 	 */
1841 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1842 		WARN_ON(!cmd->scsi_status);
1843 		ret = transport_send_check_condition_and_sense(
1844 					cmd, 0, 1);
1845 		if (ret == -EAGAIN || ret == -ENOMEM)
1846 			goto queue_full;
1847 
1848 		transport_lun_remove_cmd(cmd);
1849 		transport_cmd_check_stop_to_fabric(cmd);
1850 		return;
1851 	}
1852 	/*
1853 	 * Check for a callback, used by amongst other things
1854 	 * XDWRITE_READ_10 emulation.
1855 	 */
1856 	if (cmd->transport_complete_callback)
1857 		cmd->transport_complete_callback(cmd);
1858 
1859 	switch (cmd->data_direction) {
1860 	case DMA_FROM_DEVICE:
1861 		spin_lock(&cmd->se_lun->lun_sep_lock);
1862 		if (cmd->se_lun->lun_sep) {
1863 			cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
1864 					cmd->data_length;
1865 		}
1866 		spin_unlock(&cmd->se_lun->lun_sep_lock);
1867 
1868 		ret = cmd->se_tfo->queue_data_in(cmd);
1869 		if (ret == -EAGAIN || ret == -ENOMEM)
1870 			goto queue_full;
1871 		break;
1872 	case DMA_TO_DEVICE:
1873 		spin_lock(&cmd->se_lun->lun_sep_lock);
1874 		if (cmd->se_lun->lun_sep) {
1875 			cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
1876 				cmd->data_length;
1877 		}
1878 		spin_unlock(&cmd->se_lun->lun_sep_lock);
1879 		/*
1880 		 * Check if we need to send READ payload for BIDI-COMMAND
1881 		 */
1882 		if (cmd->t_bidi_data_sg) {
1883 			spin_lock(&cmd->se_lun->lun_sep_lock);
1884 			if (cmd->se_lun->lun_sep) {
1885 				cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
1886 					cmd->data_length;
1887 			}
1888 			spin_unlock(&cmd->se_lun->lun_sep_lock);
1889 			ret = cmd->se_tfo->queue_data_in(cmd);
1890 			if (ret == -EAGAIN || ret == -ENOMEM)
1891 				goto queue_full;
1892 			break;
1893 		}
1894 		/* Fall through for DMA_TO_DEVICE */
1895 	case DMA_NONE:
1896 		ret = cmd->se_tfo->queue_status(cmd);
1897 		if (ret == -EAGAIN || ret == -ENOMEM)
1898 			goto queue_full;
1899 		break;
1900 	default:
1901 		break;
1902 	}
1903 
1904 	transport_lun_remove_cmd(cmd);
1905 	transport_cmd_check_stop_to_fabric(cmd);
1906 	return;
1907 
1908 queue_full:
1909 	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
1910 		" data_direction: %d\n", cmd, cmd->data_direction);
1911 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1912 	transport_handle_queue_full(cmd, cmd->se_dev);
1913 }
1914 
1915 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
1916 {
1917 	struct scatterlist *sg;
1918 	int count;
1919 
1920 	for_each_sg(sgl, sg, nents, count)
1921 		__free_page(sg_page(sg));
1922 
1923 	kfree(sgl);
1924 }
1925 
1926 static inline void transport_free_pages(struct se_cmd *cmd)
1927 {
1928 	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC)
1929 		return;
1930 
1931 	transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
1932 	cmd->t_data_sg = NULL;
1933 	cmd->t_data_nents = 0;
1934 
1935 	transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
1936 	cmd->t_bidi_data_sg = NULL;
1937 	cmd->t_bidi_data_nents = 0;
1938 }
1939 
1940 /**
1941  * transport_release_cmd - free a command
1942  * @cmd:       command to free
1943  *
1944  * This routine unconditionally frees a command, and reference counting
1945  * or list removal must be done in the caller.
1946  */
1947 static int transport_release_cmd(struct se_cmd *cmd)
1948 {
1949 	BUG_ON(!cmd->se_tfo);
1950 
1951 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
1952 		core_tmr_release_req(cmd->se_tmr_req);
1953 	if (cmd->t_task_cdb != cmd->__t_task_cdb)
1954 		kfree(cmd->t_task_cdb);
1955 	/*
1956 	 * If this cmd has been setup with target_get_sess_cmd(), drop
1957 	 * the kref and call ->release_cmd() in kref callback.
1958 	 */
1959 	 if (cmd->check_release != 0)
1960 		return target_put_sess_cmd(cmd->se_sess, cmd);
1961 
1962 	cmd->se_tfo->release_cmd(cmd);
1963 	return 1;
1964 }
1965 
1966 /**
1967  * transport_put_cmd - release a reference to a command
1968  * @cmd:       command to release
1969  *
1970  * This routine releases our reference to the command and frees it if possible.
1971  */
1972 static int transport_put_cmd(struct se_cmd *cmd)
1973 {
1974 	unsigned long flags;
1975 
1976 	spin_lock_irqsave(&cmd->t_state_lock, flags);
1977 	if (atomic_read(&cmd->t_fe_count) &&
1978 	    !atomic_dec_and_test(&cmd->t_fe_count)) {
1979 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1980 		return 0;
1981 	}
1982 
1983 	if (cmd->transport_state & CMD_T_DEV_ACTIVE) {
1984 		cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
1985 		target_remove_from_state_list(cmd);
1986 	}
1987 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1988 
1989 	transport_free_pages(cmd);
1990 	return transport_release_cmd(cmd);
1991 }
1992 
1993 void *transport_kmap_data_sg(struct se_cmd *cmd)
1994 {
1995 	struct scatterlist *sg = cmd->t_data_sg;
1996 	struct page **pages;
1997 	int i;
1998 
1999 	/*
2000 	 * We need to take into account a possible offset here for fabrics like
2001 	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2002 	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2003 	 */
2004 	if (!cmd->t_data_nents)
2005 		return NULL;
2006 
2007 	BUG_ON(!sg);
2008 	if (cmd->t_data_nents == 1)
2009 		return kmap(sg_page(sg)) + sg->offset;
2010 
2011 	/* >1 page. use vmap */
2012 	pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2013 	if (!pages)
2014 		return NULL;
2015 
2016 	/* convert sg[] to pages[] */
2017 	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2018 		pages[i] = sg_page(sg);
2019 	}
2020 
2021 	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2022 	kfree(pages);
2023 	if (!cmd->t_data_vmap)
2024 		return NULL;
2025 
2026 	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2027 }
2028 EXPORT_SYMBOL(transport_kmap_data_sg);
2029 
2030 void transport_kunmap_data_sg(struct se_cmd *cmd)
2031 {
2032 	if (!cmd->t_data_nents) {
2033 		return;
2034 	} else if (cmd->t_data_nents == 1) {
2035 		kunmap(sg_page(cmd->t_data_sg));
2036 		return;
2037 	}
2038 
2039 	vunmap(cmd->t_data_vmap);
2040 	cmd->t_data_vmap = NULL;
2041 }
2042 EXPORT_SYMBOL(transport_kunmap_data_sg);
2043 
2044 static int
2045 transport_generic_get_mem(struct se_cmd *cmd)
2046 {
2047 	u32 length = cmd->data_length;
2048 	unsigned int nents;
2049 	struct page *page;
2050 	gfp_t zero_flag;
2051 	int i = 0;
2052 
2053 	nents = DIV_ROUND_UP(length, PAGE_SIZE);
2054 	cmd->t_data_sg = kmalloc(sizeof(struct scatterlist) * nents, GFP_KERNEL);
2055 	if (!cmd->t_data_sg)
2056 		return -ENOMEM;
2057 
2058 	cmd->t_data_nents = nents;
2059 	sg_init_table(cmd->t_data_sg, nents);
2060 
2061 	zero_flag = cmd->se_cmd_flags & SCF_SCSI_DATA_CDB ? 0 : __GFP_ZERO;
2062 
2063 	while (length) {
2064 		u32 page_len = min_t(u32, length, PAGE_SIZE);
2065 		page = alloc_page(GFP_KERNEL | zero_flag);
2066 		if (!page)
2067 			goto out;
2068 
2069 		sg_set_page(&cmd->t_data_sg[i], page, page_len, 0);
2070 		length -= page_len;
2071 		i++;
2072 	}
2073 	return 0;
2074 
2075 out:
2076 	while (i > 0) {
2077 		i--;
2078 		__free_page(sg_page(&cmd->t_data_sg[i]));
2079 	}
2080 	kfree(cmd->t_data_sg);
2081 	cmd->t_data_sg = NULL;
2082 	return -ENOMEM;
2083 }
2084 
2085 /*
2086  * Allocate any required resources to execute the command.  For writes we
2087  * might not have the payload yet, so notify the fabric via a call to
2088  * ->write_pending instead. Otherwise place it on the execution queue.
2089  */
2090 sense_reason_t
2091 transport_generic_new_cmd(struct se_cmd *cmd)
2092 {
2093 	int ret = 0;
2094 
2095 	/*
2096 	 * Determine is the TCM fabric module has already allocated physical
2097 	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2098 	 * beforehand.
2099 	 */
2100 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2101 	    cmd->data_length) {
2102 		ret = transport_generic_get_mem(cmd);
2103 		if (ret < 0)
2104 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2105 	}
2106 
2107 	atomic_inc(&cmd->t_fe_count);
2108 
2109 	/*
2110 	 * If this command is not a write we can execute it right here,
2111 	 * for write buffers we need to notify the fabric driver first
2112 	 * and let it call back once the write buffers are ready.
2113 	 */
2114 	target_add_to_state_list(cmd);
2115 	if (cmd->data_direction != DMA_TO_DEVICE) {
2116 		target_execute_cmd(cmd);
2117 		return 0;
2118 	}
2119 
2120 	spin_lock_irq(&cmd->t_state_lock);
2121 	cmd->t_state = TRANSPORT_WRITE_PENDING;
2122 	spin_unlock_irq(&cmd->t_state_lock);
2123 
2124 	transport_cmd_check_stop(cmd, false);
2125 
2126 	ret = cmd->se_tfo->write_pending(cmd);
2127 	if (ret == -EAGAIN || ret == -ENOMEM)
2128 		goto queue_full;
2129 
2130 	/* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2131 	WARN_ON(ret);
2132 
2133 	return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2134 
2135 queue_full:
2136 	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2137 	cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2138 	transport_handle_queue_full(cmd, cmd->se_dev);
2139 	return 0;
2140 }
2141 EXPORT_SYMBOL(transport_generic_new_cmd);
2142 
2143 static void transport_write_pending_qf(struct se_cmd *cmd)
2144 {
2145 	int ret;
2146 
2147 	ret = cmd->se_tfo->write_pending(cmd);
2148 	if (ret == -EAGAIN || ret == -ENOMEM) {
2149 		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2150 			 cmd);
2151 		transport_handle_queue_full(cmd, cmd->se_dev);
2152 	}
2153 }
2154 
2155 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2156 {
2157 	int ret = 0;
2158 
2159 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2160 		if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2161 			 transport_wait_for_tasks(cmd);
2162 
2163 		ret = transport_release_cmd(cmd);
2164 	} else {
2165 		if (wait_for_tasks)
2166 			transport_wait_for_tasks(cmd);
2167 
2168 		if (cmd->se_lun)
2169 			transport_lun_remove_cmd(cmd);
2170 
2171 		ret = transport_put_cmd(cmd);
2172 	}
2173 	return ret;
2174 }
2175 EXPORT_SYMBOL(transport_generic_free_cmd);
2176 
2177 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2178  * @se_sess:	session to reference
2179  * @se_cmd:	command descriptor to add
2180  * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
2181  */
2182 int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
2183 			       bool ack_kref)
2184 {
2185 	unsigned long flags;
2186 	int ret = 0;
2187 
2188 	kref_init(&se_cmd->cmd_kref);
2189 	/*
2190 	 * Add a second kref if the fabric caller is expecting to handle
2191 	 * fabric acknowledgement that requires two target_put_sess_cmd()
2192 	 * invocations before se_cmd descriptor release.
2193 	 */
2194 	if (ack_kref == true) {
2195 		kref_get(&se_cmd->cmd_kref);
2196 		se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2197 	}
2198 
2199 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2200 	if (se_sess->sess_tearing_down) {
2201 		ret = -ESHUTDOWN;
2202 		goto out;
2203 	}
2204 	list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2205 	se_cmd->check_release = 1;
2206 
2207 out:
2208 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2209 	return ret;
2210 }
2211 EXPORT_SYMBOL(target_get_sess_cmd);
2212 
2213 static void target_release_cmd_kref(struct kref *kref)
2214 {
2215 	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2216 	struct se_session *se_sess = se_cmd->se_sess;
2217 
2218 	if (list_empty(&se_cmd->se_cmd_list)) {
2219 		spin_unlock(&se_sess->sess_cmd_lock);
2220 		se_cmd->se_tfo->release_cmd(se_cmd);
2221 		return;
2222 	}
2223 	if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2224 		spin_unlock(&se_sess->sess_cmd_lock);
2225 		complete(&se_cmd->cmd_wait_comp);
2226 		return;
2227 	}
2228 	list_del(&se_cmd->se_cmd_list);
2229 	spin_unlock(&se_sess->sess_cmd_lock);
2230 
2231 	se_cmd->se_tfo->release_cmd(se_cmd);
2232 }
2233 
2234 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2235  * @se_sess:	session to reference
2236  * @se_cmd:	command descriptor to drop
2237  */
2238 int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd)
2239 {
2240 	return kref_put_spinlock_irqsave(&se_cmd->cmd_kref, target_release_cmd_kref,
2241 			&se_sess->sess_cmd_lock);
2242 }
2243 EXPORT_SYMBOL(target_put_sess_cmd);
2244 
2245 /* target_sess_cmd_list_set_waiting - Flag all commands in
2246  *         sess_cmd_list to complete cmd_wait_comp.  Set
2247  *         sess_tearing_down so no more commands are queued.
2248  * @se_sess:	session to flag
2249  */
2250 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2251 {
2252 	struct se_cmd *se_cmd;
2253 	unsigned long flags;
2254 
2255 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2256 	if (se_sess->sess_tearing_down) {
2257 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2258 		return;
2259 	}
2260 	se_sess->sess_tearing_down = 1;
2261 	list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2262 
2263 	list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list)
2264 		se_cmd->cmd_wait_set = 1;
2265 
2266 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2267 }
2268 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2269 
2270 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2271  * @se_sess:    session to wait for active I/O
2272  */
2273 void target_wait_for_sess_cmds(struct se_session *se_sess)
2274 {
2275 	struct se_cmd *se_cmd, *tmp_cmd;
2276 	unsigned long flags;
2277 
2278 	list_for_each_entry_safe(se_cmd, tmp_cmd,
2279 				&se_sess->sess_wait_list, se_cmd_list) {
2280 		list_del(&se_cmd->se_cmd_list);
2281 
2282 		pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2283 			" %d\n", se_cmd, se_cmd->t_state,
2284 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2285 
2286 		wait_for_completion(&se_cmd->cmd_wait_comp);
2287 		pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2288 			" fabric state: %d\n", se_cmd, se_cmd->t_state,
2289 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2290 
2291 		se_cmd->se_tfo->release_cmd(se_cmd);
2292 	}
2293 
2294 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2295 	WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2296 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2297 
2298 }
2299 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2300 
2301 /*	transport_lun_wait_for_tasks():
2302  *
2303  *	Called from ConfigFS context to stop the passed struct se_cmd to allow
2304  *	an struct se_lun to be successfully shutdown.
2305  */
2306 static int transport_lun_wait_for_tasks(struct se_cmd *cmd, struct se_lun *lun)
2307 {
2308 	unsigned long flags;
2309 	int ret = 0;
2310 
2311 	/*
2312 	 * If the frontend has already requested this struct se_cmd to
2313 	 * be stopped, we can safely ignore this struct se_cmd.
2314 	 */
2315 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2316 	if (cmd->transport_state & CMD_T_STOP) {
2317 		cmd->transport_state &= ~CMD_T_LUN_STOP;
2318 
2319 		pr_debug("ConfigFS ITT[0x%08x] - CMD_T_STOP, skipping\n",
2320 			 cmd->se_tfo->get_task_tag(cmd));
2321 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2322 		transport_cmd_check_stop(cmd, false);
2323 		return -EPERM;
2324 	}
2325 	cmd->transport_state |= CMD_T_LUN_FE_STOP;
2326 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2327 
2328 	// XXX: audit task_flags checks.
2329 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2330 	if ((cmd->transport_state & CMD_T_BUSY) &&
2331 	    (cmd->transport_state & CMD_T_SENT)) {
2332 		if (!target_stop_cmd(cmd, &flags))
2333 			ret++;
2334 	}
2335 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2336 
2337 	pr_debug("ConfigFS: cmd: %p stop tasks ret:"
2338 			" %d\n", cmd, ret);
2339 	if (!ret) {
2340 		pr_debug("ConfigFS: ITT[0x%08x] - stopping cmd....\n",
2341 				cmd->se_tfo->get_task_tag(cmd));
2342 		wait_for_completion(&cmd->transport_lun_stop_comp);
2343 		pr_debug("ConfigFS: ITT[0x%08x] - stopped cmd....\n",
2344 				cmd->se_tfo->get_task_tag(cmd));
2345 	}
2346 
2347 	return 0;
2348 }
2349 
2350 static void __transport_clear_lun_from_sessions(struct se_lun *lun)
2351 {
2352 	struct se_cmd *cmd = NULL;
2353 	unsigned long lun_flags, cmd_flags;
2354 	/*
2355 	 * Do exception processing and return CHECK_CONDITION status to the
2356 	 * Initiator Port.
2357 	 */
2358 	spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2359 	while (!list_empty(&lun->lun_cmd_list)) {
2360 		cmd = list_first_entry(&lun->lun_cmd_list,
2361 		       struct se_cmd, se_lun_node);
2362 		list_del_init(&cmd->se_lun_node);
2363 
2364 		spin_lock(&cmd->t_state_lock);
2365 		pr_debug("SE_LUN[%d] - Setting cmd->transport"
2366 			"_lun_stop for  ITT: 0x%08x\n",
2367 			cmd->se_lun->unpacked_lun,
2368 			cmd->se_tfo->get_task_tag(cmd));
2369 		cmd->transport_state |= CMD_T_LUN_STOP;
2370 		spin_unlock(&cmd->t_state_lock);
2371 
2372 		spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
2373 
2374 		if (!cmd->se_lun) {
2375 			pr_err("ITT: 0x%08x, [i,t]_state: %u/%u\n",
2376 				cmd->se_tfo->get_task_tag(cmd),
2377 				cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2378 			BUG();
2379 		}
2380 		/*
2381 		 * If the Storage engine still owns the iscsi_cmd_t, determine
2382 		 * and/or stop its context.
2383 		 */
2384 		pr_debug("SE_LUN[%d] - ITT: 0x%08x before transport"
2385 			"_lun_wait_for_tasks()\n", cmd->se_lun->unpacked_lun,
2386 			cmd->se_tfo->get_task_tag(cmd));
2387 
2388 		if (transport_lun_wait_for_tasks(cmd, cmd->se_lun) < 0) {
2389 			spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2390 			continue;
2391 		}
2392 
2393 		pr_debug("SE_LUN[%d] - ITT: 0x%08x after transport_lun"
2394 			"_wait_for_tasks(): SUCCESS\n",
2395 			cmd->se_lun->unpacked_lun,
2396 			cmd->se_tfo->get_task_tag(cmd));
2397 
2398 		spin_lock_irqsave(&cmd->t_state_lock, cmd_flags);
2399 		if (!(cmd->transport_state & CMD_T_DEV_ACTIVE)) {
2400 			spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2401 			goto check_cond;
2402 		}
2403 		cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
2404 		target_remove_from_state_list(cmd);
2405 		spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2406 
2407 		/*
2408 		 * The Storage engine stopped this struct se_cmd before it was
2409 		 * send to the fabric frontend for delivery back to the
2410 		 * Initiator Node.  Return this SCSI CDB back with an
2411 		 * CHECK_CONDITION status.
2412 		 */
2413 check_cond:
2414 		transport_send_check_condition_and_sense(cmd,
2415 				TCM_NON_EXISTENT_LUN, 0);
2416 		/*
2417 		 *  If the fabric frontend is waiting for this iscsi_cmd_t to
2418 		 * be released, notify the waiting thread now that LU has
2419 		 * finished accessing it.
2420 		 */
2421 		spin_lock_irqsave(&cmd->t_state_lock, cmd_flags);
2422 		if (cmd->transport_state & CMD_T_LUN_FE_STOP) {
2423 			pr_debug("SE_LUN[%d] - Detected FE stop for"
2424 				" struct se_cmd: %p ITT: 0x%08x\n",
2425 				lun->unpacked_lun,
2426 				cmd, cmd->se_tfo->get_task_tag(cmd));
2427 
2428 			spin_unlock_irqrestore(&cmd->t_state_lock,
2429 					cmd_flags);
2430 			transport_cmd_check_stop(cmd, false);
2431 			complete(&cmd->transport_lun_fe_stop_comp);
2432 			spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2433 			continue;
2434 		}
2435 		pr_debug("SE_LUN[%d] - ITT: 0x%08x finished processing\n",
2436 			lun->unpacked_lun, cmd->se_tfo->get_task_tag(cmd));
2437 
2438 		spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2439 		spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2440 	}
2441 	spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
2442 }
2443 
2444 static int transport_clear_lun_thread(void *p)
2445 {
2446 	struct se_lun *lun = p;
2447 
2448 	__transport_clear_lun_from_sessions(lun);
2449 	complete(&lun->lun_shutdown_comp);
2450 
2451 	return 0;
2452 }
2453 
2454 int transport_clear_lun_from_sessions(struct se_lun *lun)
2455 {
2456 	struct task_struct *kt;
2457 
2458 	kt = kthread_run(transport_clear_lun_thread, lun,
2459 			"tcm_cl_%u", lun->unpacked_lun);
2460 	if (IS_ERR(kt)) {
2461 		pr_err("Unable to start clear_lun thread\n");
2462 		return PTR_ERR(kt);
2463 	}
2464 	wait_for_completion(&lun->lun_shutdown_comp);
2465 
2466 	return 0;
2467 }
2468 
2469 /**
2470  * transport_wait_for_tasks - wait for completion to occur
2471  * @cmd:	command to wait
2472  *
2473  * Called from frontend fabric context to wait for storage engine
2474  * to pause and/or release frontend generated struct se_cmd.
2475  */
2476 bool transport_wait_for_tasks(struct se_cmd *cmd)
2477 {
2478 	unsigned long flags;
2479 
2480 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2481 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2482 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2483 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2484 		return false;
2485 	}
2486 
2487 	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2488 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2489 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2490 		return false;
2491 	}
2492 	/*
2493 	 * If we are already stopped due to an external event (ie: LUN shutdown)
2494 	 * sleep until the connection can have the passed struct se_cmd back.
2495 	 * The cmd->transport_lun_stopped_sem will be upped by
2496 	 * transport_clear_lun_from_sessions() once the ConfigFS context caller
2497 	 * has completed its operation on the struct se_cmd.
2498 	 */
2499 	if (cmd->transport_state & CMD_T_LUN_STOP) {
2500 		pr_debug("wait_for_tasks: Stopping"
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 		 * There is a special case for WRITES where a FE exception +
2506 		 * LUN shutdown means ConfigFS context is still sleeping on
2507 		 * transport_lun_stop_comp in transport_lun_wait_for_tasks().
2508 		 * We go ahead and up transport_lun_stop_comp just to be sure
2509 		 * here.
2510 		 */
2511 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2512 		complete(&cmd->transport_lun_stop_comp);
2513 		wait_for_completion(&cmd->transport_lun_fe_stop_comp);
2514 		spin_lock_irqsave(&cmd->t_state_lock, flags);
2515 
2516 		target_remove_from_state_list(cmd);
2517 		/*
2518 		 * At this point, the frontend who was the originator of this
2519 		 * struct se_cmd, now owns the structure and can be released through
2520 		 * normal means below.
2521 		 */
2522 		pr_debug("wait_for_tasks: Stopped"
2523 			" wait_for_completion(&cmd->t_tasktransport_lun_fe_"
2524 			"stop_comp); for ITT: 0x%08x\n",
2525 			cmd->se_tfo->get_task_tag(cmd));
2526 
2527 		cmd->transport_state &= ~CMD_T_LUN_STOP;
2528 	}
2529 
2530 	if (!(cmd->transport_state & CMD_T_ACTIVE)) {
2531 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2532 		return false;
2533 	}
2534 
2535 	cmd->transport_state |= CMD_T_STOP;
2536 
2537 	pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
2538 		" i_state: %d, t_state: %d, CMD_T_STOP\n",
2539 		cmd, cmd->se_tfo->get_task_tag(cmd),
2540 		cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2541 
2542 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2543 
2544 	wait_for_completion(&cmd->t_transport_stop_comp);
2545 
2546 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2547 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2548 
2549 	pr_debug("wait_for_tasks: Stopped wait_for_completion("
2550 		"&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
2551 		cmd->se_tfo->get_task_tag(cmd));
2552 
2553 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2554 
2555 	return true;
2556 }
2557 EXPORT_SYMBOL(transport_wait_for_tasks);
2558 
2559 static int transport_get_sense_codes(
2560 	struct se_cmd *cmd,
2561 	u8 *asc,
2562 	u8 *ascq)
2563 {
2564 	*asc = cmd->scsi_asc;
2565 	*ascq = cmd->scsi_ascq;
2566 
2567 	return 0;
2568 }
2569 
2570 int
2571 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2572 		sense_reason_t reason, int from_transport)
2573 {
2574 	unsigned char *buffer = cmd->sense_buffer;
2575 	unsigned long flags;
2576 	u8 asc = 0, ascq = 0;
2577 
2578 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2579 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2580 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2581 		return 0;
2582 	}
2583 	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2584 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2585 
2586 	if (!reason && from_transport)
2587 		goto after_reason;
2588 
2589 	if (!from_transport)
2590 		cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2591 
2592 	/*
2593 	 * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
2594 	 * SENSE KEY values from include/scsi/scsi.h
2595 	 */
2596 	switch (reason) {
2597 	case TCM_NO_SENSE:
2598 		/* CURRENT ERROR */
2599 		buffer[0] = 0x70;
2600 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2601 		/* Not Ready */
2602 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2603 		/* NO ADDITIONAL SENSE INFORMATION */
2604 		buffer[SPC_ASC_KEY_OFFSET] = 0;
2605 		buffer[SPC_ASCQ_KEY_OFFSET] = 0;
2606 		break;
2607 	case TCM_NON_EXISTENT_LUN:
2608 		/* CURRENT ERROR */
2609 		buffer[0] = 0x70;
2610 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2611 		/* ILLEGAL REQUEST */
2612 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2613 		/* LOGICAL UNIT NOT SUPPORTED */
2614 		buffer[SPC_ASC_KEY_OFFSET] = 0x25;
2615 		break;
2616 	case TCM_UNSUPPORTED_SCSI_OPCODE:
2617 	case TCM_SECTOR_COUNT_TOO_MANY:
2618 		/* CURRENT ERROR */
2619 		buffer[0] = 0x70;
2620 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2621 		/* ILLEGAL REQUEST */
2622 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2623 		/* INVALID COMMAND OPERATION CODE */
2624 		buffer[SPC_ASC_KEY_OFFSET] = 0x20;
2625 		break;
2626 	case TCM_UNKNOWN_MODE_PAGE:
2627 		/* CURRENT ERROR */
2628 		buffer[0] = 0x70;
2629 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2630 		/* ILLEGAL REQUEST */
2631 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2632 		/* INVALID FIELD IN CDB */
2633 		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2634 		break;
2635 	case TCM_CHECK_CONDITION_ABORT_CMD:
2636 		/* CURRENT ERROR */
2637 		buffer[0] = 0x70;
2638 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2639 		/* ABORTED COMMAND */
2640 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2641 		/* BUS DEVICE RESET FUNCTION OCCURRED */
2642 		buffer[SPC_ASC_KEY_OFFSET] = 0x29;
2643 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2644 		break;
2645 	case TCM_INCORRECT_AMOUNT_OF_DATA:
2646 		/* CURRENT ERROR */
2647 		buffer[0] = 0x70;
2648 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2649 		/* ABORTED COMMAND */
2650 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2651 		/* WRITE ERROR */
2652 		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2653 		/* NOT ENOUGH UNSOLICITED DATA */
2654 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0d;
2655 		break;
2656 	case TCM_INVALID_CDB_FIELD:
2657 		/* CURRENT ERROR */
2658 		buffer[0] = 0x70;
2659 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2660 		/* ILLEGAL REQUEST */
2661 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2662 		/* INVALID FIELD IN CDB */
2663 		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2664 		break;
2665 	case TCM_INVALID_PARAMETER_LIST:
2666 		/* CURRENT ERROR */
2667 		buffer[0] = 0x70;
2668 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2669 		/* ILLEGAL REQUEST */
2670 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2671 		/* INVALID FIELD IN PARAMETER LIST */
2672 		buffer[SPC_ASC_KEY_OFFSET] = 0x26;
2673 		break;
2674 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
2675 		/* CURRENT ERROR */
2676 		buffer[0] = 0x70;
2677 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2678 		/* ILLEGAL REQUEST */
2679 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2680 		/* PARAMETER LIST LENGTH ERROR */
2681 		buffer[SPC_ASC_KEY_OFFSET] = 0x1a;
2682 		break;
2683 	case TCM_UNEXPECTED_UNSOLICITED_DATA:
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 		/* WRITE ERROR */
2690 		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2691 		/* UNEXPECTED_UNSOLICITED_DATA */
2692 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0c;
2693 		break;
2694 	case TCM_SERVICE_CRC_ERROR:
2695 		/* CURRENT ERROR */
2696 		buffer[0] = 0x70;
2697 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2698 		/* ABORTED COMMAND */
2699 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2700 		/* PROTOCOL SERVICE CRC ERROR */
2701 		buffer[SPC_ASC_KEY_OFFSET] = 0x47;
2702 		/* N/A */
2703 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x05;
2704 		break;
2705 	case TCM_SNACK_REJECTED:
2706 		/* CURRENT ERROR */
2707 		buffer[0] = 0x70;
2708 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2709 		/* ABORTED COMMAND */
2710 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2711 		/* READ ERROR */
2712 		buffer[SPC_ASC_KEY_OFFSET] = 0x11;
2713 		/* FAILED RETRANSMISSION REQUEST */
2714 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x13;
2715 		break;
2716 	case TCM_WRITE_PROTECTED:
2717 		/* CURRENT ERROR */
2718 		buffer[0] = 0x70;
2719 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2720 		/* DATA PROTECT */
2721 		buffer[SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
2722 		/* WRITE PROTECTED */
2723 		buffer[SPC_ASC_KEY_OFFSET] = 0x27;
2724 		break;
2725 	case TCM_ADDRESS_OUT_OF_RANGE:
2726 		/* CURRENT ERROR */
2727 		buffer[0] = 0x70;
2728 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2729 		/* ILLEGAL REQUEST */
2730 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2731 		/* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2732 		buffer[SPC_ASC_KEY_OFFSET] = 0x21;
2733 		break;
2734 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2735 		/* CURRENT ERROR */
2736 		buffer[0] = 0x70;
2737 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2738 		/* UNIT ATTENTION */
2739 		buffer[SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
2740 		core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2741 		buffer[SPC_ASC_KEY_OFFSET] = asc;
2742 		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2743 		break;
2744 	case TCM_CHECK_CONDITION_NOT_READY:
2745 		/* CURRENT ERROR */
2746 		buffer[0] = 0x70;
2747 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2748 		/* Not Ready */
2749 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2750 		transport_get_sense_codes(cmd, &asc, &ascq);
2751 		buffer[SPC_ASC_KEY_OFFSET] = asc;
2752 		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2753 		break;
2754 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
2755 	default:
2756 		/* CURRENT ERROR */
2757 		buffer[0] = 0x70;
2758 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2759 		/*
2760 		 * Returning ILLEGAL REQUEST would cause immediate IO errors on
2761 		 * Solaris initiators.  Returning NOT READY instead means the
2762 		 * operations will be retried a finite number of times and we
2763 		 * can survive intermittent errors.
2764 		 */
2765 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2766 		/* LOGICAL UNIT COMMUNICATION FAILURE */
2767 		buffer[SPC_ASC_KEY_OFFSET] = 0x08;
2768 		break;
2769 	}
2770 	/*
2771 	 * This code uses linux/include/scsi/scsi.h SAM status codes!
2772 	 */
2773 	cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2774 	/*
2775 	 * Automatically padded, this value is encoded in the fabric's
2776 	 * data_length response PDU containing the SCSI defined sense data.
2777 	 */
2778 	cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2779 
2780 after_reason:
2781 	return cmd->se_tfo->queue_status(cmd);
2782 }
2783 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2784 
2785 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2786 {
2787 	if (!(cmd->transport_state & CMD_T_ABORTED))
2788 		return 0;
2789 
2790 	if (!send_status || (cmd->se_cmd_flags & SCF_SENT_DELAYED_TAS))
2791 		return 1;
2792 
2793 	pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08x\n",
2794 		 cmd->t_task_cdb[0], cmd->se_tfo->get_task_tag(cmd));
2795 
2796 	cmd->se_cmd_flags |= SCF_SENT_DELAYED_TAS;
2797 	cmd->se_tfo->queue_status(cmd);
2798 
2799 	return 1;
2800 }
2801 EXPORT_SYMBOL(transport_check_aborted_status);
2802 
2803 void transport_send_task_abort(struct se_cmd *cmd)
2804 {
2805 	unsigned long flags;
2806 
2807 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2808 	if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION | SCF_SENT_DELAYED_TAS)) {
2809 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2810 		return;
2811 	}
2812 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2813 
2814 	/*
2815 	 * If there are still expected incoming fabric WRITEs, we wait
2816 	 * until until they have completed before sending a TASK_ABORTED
2817 	 * response.  This response with TASK_ABORTED status will be
2818 	 * queued back to fabric module by transport_check_aborted_status().
2819 	 */
2820 	if (cmd->data_direction == DMA_TO_DEVICE) {
2821 		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
2822 			cmd->transport_state |= CMD_T_ABORTED;
2823 			smp_mb__after_atomic_inc();
2824 		}
2825 	}
2826 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2827 
2828 	transport_lun_remove_cmd(cmd);
2829 
2830 	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
2831 		" ITT: 0x%08x\n", cmd->t_task_cdb[0],
2832 		cmd->se_tfo->get_task_tag(cmd));
2833 
2834 	cmd->se_tfo->queue_status(cmd);
2835 }
2836 
2837 static void target_tmr_work(struct work_struct *work)
2838 {
2839 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2840 	struct se_device *dev = cmd->se_dev;
2841 	struct se_tmr_req *tmr = cmd->se_tmr_req;
2842 	int ret;
2843 
2844 	switch (tmr->function) {
2845 	case TMR_ABORT_TASK:
2846 		core_tmr_abort_task(dev, tmr, cmd->se_sess);
2847 		break;
2848 	case TMR_ABORT_TASK_SET:
2849 	case TMR_CLEAR_ACA:
2850 	case TMR_CLEAR_TASK_SET:
2851 		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
2852 		break;
2853 	case TMR_LUN_RESET:
2854 		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
2855 		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
2856 					 TMR_FUNCTION_REJECTED;
2857 		break;
2858 	case TMR_TARGET_WARM_RESET:
2859 		tmr->response = TMR_FUNCTION_REJECTED;
2860 		break;
2861 	case TMR_TARGET_COLD_RESET:
2862 		tmr->response = TMR_FUNCTION_REJECTED;
2863 		break;
2864 	default:
2865 		pr_err("Uknown TMR function: 0x%02x.\n",
2866 				tmr->function);
2867 		tmr->response = TMR_FUNCTION_REJECTED;
2868 		break;
2869 	}
2870 
2871 	cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
2872 	cmd->se_tfo->queue_tm_rsp(cmd);
2873 
2874 	transport_cmd_check_stop_to_fabric(cmd);
2875 }
2876 
2877 int transport_generic_handle_tmr(
2878 	struct se_cmd *cmd)
2879 {
2880 	INIT_WORK(&cmd->work, target_tmr_work);
2881 	queue_work(cmd->se_dev->tmr_wq, &cmd->work);
2882 	return 0;
2883 }
2884 EXPORT_SYMBOL(transport_generic_handle_tmr);
2885