xref: /linux/drivers/target/target_core_transport.c (revision b9ccfda293ee6fca9a89a1584f0900e0627b975e)
1 /*******************************************************************************
2  * Filename:  target_core_transport.c
3  *
4  * This file contains the Generic Target Engine Core.
5  *
6  * Copyright (c) 2002, 2003, 2004, 2005 PyX Technologies, Inc.
7  * Copyright (c) 2005, 2006, 2007 SBE, Inc.
8  * Copyright (c) 2007-2010 Rising Tide Systems
9  * Copyright (c) 2008-2010 Linux-iSCSI.org
10  *
11  * Nicholas A. Bellinger <nab@kernel.org>
12  *
13  * This program is free software; you can redistribute it and/or modify
14  * it under the terms of the GNU General Public License as published by
15  * the Free Software Foundation; either version 2 of the License, or
16  * (at your option) any later version.
17  *
18  * This program is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
21  * GNU General Public License for more details.
22  *
23  * You should have received a copy of the GNU General Public License
24  * along with this program; if not, write to the Free Software
25  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
26  *
27  ******************************************************************************/
28 
29 #include <linux/net.h>
30 #include <linux/delay.h>
31 #include <linux/string.h>
32 #include <linux/timer.h>
33 #include <linux/slab.h>
34 #include <linux/blkdev.h>
35 #include <linux/spinlock.h>
36 #include <linux/kthread.h>
37 #include <linux/in.h>
38 #include <linux/cdrom.h>
39 #include <linux/module.h>
40 #include <linux/ratelimit.h>
41 #include <asm/unaligned.h>
42 #include <net/sock.h>
43 #include <net/tcp.h>
44 #include <scsi/scsi.h>
45 #include <scsi/scsi_cmnd.h>
46 #include <scsi/scsi_tcq.h>
47 
48 #include <target/target_core_base.h>
49 #include <target/target_core_backend.h>
50 #include <target/target_core_fabric.h>
51 #include <target/target_core_configfs.h>
52 
53 #include "target_core_internal.h"
54 #include "target_core_alua.h"
55 #include "target_core_pr.h"
56 #include "target_core_ua.h"
57 
58 static int sub_api_initialized;
59 
60 static struct workqueue_struct *target_completion_wq;
61 static struct kmem_cache *se_sess_cache;
62 struct kmem_cache *se_ua_cache;
63 struct kmem_cache *t10_pr_reg_cache;
64 struct kmem_cache *t10_alua_lu_gp_cache;
65 struct kmem_cache *t10_alua_lu_gp_mem_cache;
66 struct kmem_cache *t10_alua_tg_pt_gp_cache;
67 struct kmem_cache *t10_alua_tg_pt_gp_mem_cache;
68 
69 static void transport_complete_task_attr(struct se_cmd *cmd);
70 static void transport_handle_queue_full(struct se_cmd *cmd,
71 		struct se_device *dev);
72 static int transport_generic_get_mem(struct se_cmd *cmd);
73 static int target_get_sess_cmd(struct se_session *, struct se_cmd *, bool);
74 static void transport_put_cmd(struct se_cmd *cmd);
75 static int transport_set_sense_codes(struct se_cmd *cmd, u8 asc, u8 ascq);
76 static void target_complete_ok_work(struct work_struct *work);
77 
78 int init_se_kmem_caches(void)
79 {
80 	se_sess_cache = kmem_cache_create("se_sess_cache",
81 			sizeof(struct se_session), __alignof__(struct se_session),
82 			0, NULL);
83 	if (!se_sess_cache) {
84 		pr_err("kmem_cache_create() for struct se_session"
85 				" failed\n");
86 		goto out;
87 	}
88 	se_ua_cache = kmem_cache_create("se_ua_cache",
89 			sizeof(struct se_ua), __alignof__(struct se_ua),
90 			0, NULL);
91 	if (!se_ua_cache) {
92 		pr_err("kmem_cache_create() for struct se_ua failed\n");
93 		goto out_free_sess_cache;
94 	}
95 	t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
96 			sizeof(struct t10_pr_registration),
97 			__alignof__(struct t10_pr_registration), 0, NULL);
98 	if (!t10_pr_reg_cache) {
99 		pr_err("kmem_cache_create() for struct t10_pr_registration"
100 				" failed\n");
101 		goto out_free_ua_cache;
102 	}
103 	t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
104 			sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
105 			0, NULL);
106 	if (!t10_alua_lu_gp_cache) {
107 		pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
108 				" failed\n");
109 		goto out_free_pr_reg_cache;
110 	}
111 	t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
112 			sizeof(struct t10_alua_lu_gp_member),
113 			__alignof__(struct t10_alua_lu_gp_member), 0, NULL);
114 	if (!t10_alua_lu_gp_mem_cache) {
115 		pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
116 				"cache failed\n");
117 		goto out_free_lu_gp_cache;
118 	}
119 	t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
120 			sizeof(struct t10_alua_tg_pt_gp),
121 			__alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
122 	if (!t10_alua_tg_pt_gp_cache) {
123 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
124 				"cache failed\n");
125 		goto out_free_lu_gp_mem_cache;
126 	}
127 	t10_alua_tg_pt_gp_mem_cache = kmem_cache_create(
128 			"t10_alua_tg_pt_gp_mem_cache",
129 			sizeof(struct t10_alua_tg_pt_gp_member),
130 			__alignof__(struct t10_alua_tg_pt_gp_member),
131 			0, NULL);
132 	if (!t10_alua_tg_pt_gp_mem_cache) {
133 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
134 				"mem_t failed\n");
135 		goto out_free_tg_pt_gp_cache;
136 	}
137 
138 	target_completion_wq = alloc_workqueue("target_completion",
139 					       WQ_MEM_RECLAIM, 0);
140 	if (!target_completion_wq)
141 		goto out_free_tg_pt_gp_mem_cache;
142 
143 	return 0;
144 
145 out_free_tg_pt_gp_mem_cache:
146 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
147 out_free_tg_pt_gp_cache:
148 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
149 out_free_lu_gp_mem_cache:
150 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
151 out_free_lu_gp_cache:
152 	kmem_cache_destroy(t10_alua_lu_gp_cache);
153 out_free_pr_reg_cache:
154 	kmem_cache_destroy(t10_pr_reg_cache);
155 out_free_ua_cache:
156 	kmem_cache_destroy(se_ua_cache);
157 out_free_sess_cache:
158 	kmem_cache_destroy(se_sess_cache);
159 out:
160 	return -ENOMEM;
161 }
162 
163 void release_se_kmem_caches(void)
164 {
165 	destroy_workqueue(target_completion_wq);
166 	kmem_cache_destroy(se_sess_cache);
167 	kmem_cache_destroy(se_ua_cache);
168 	kmem_cache_destroy(t10_pr_reg_cache);
169 	kmem_cache_destroy(t10_alua_lu_gp_cache);
170 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
171 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
172 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
173 }
174 
175 /* This code ensures unique mib indexes are handed out. */
176 static DEFINE_SPINLOCK(scsi_mib_index_lock);
177 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
178 
179 /*
180  * Allocate a new row index for the entry type specified
181  */
182 u32 scsi_get_new_index(scsi_index_t type)
183 {
184 	u32 new_index;
185 
186 	BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
187 
188 	spin_lock(&scsi_mib_index_lock);
189 	new_index = ++scsi_mib_index[type];
190 	spin_unlock(&scsi_mib_index_lock);
191 
192 	return new_index;
193 }
194 
195 void transport_subsystem_check_init(void)
196 {
197 	int ret;
198 
199 	if (sub_api_initialized)
200 		return;
201 
202 	ret = request_module("target_core_iblock");
203 	if (ret != 0)
204 		pr_err("Unable to load target_core_iblock\n");
205 
206 	ret = request_module("target_core_file");
207 	if (ret != 0)
208 		pr_err("Unable to load target_core_file\n");
209 
210 	ret = request_module("target_core_pscsi");
211 	if (ret != 0)
212 		pr_err("Unable to load target_core_pscsi\n");
213 
214 	ret = request_module("target_core_stgt");
215 	if (ret != 0)
216 		pr_err("Unable to load target_core_stgt\n");
217 
218 	sub_api_initialized = 1;
219 	return;
220 }
221 
222 struct se_session *transport_init_session(void)
223 {
224 	struct se_session *se_sess;
225 
226 	se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
227 	if (!se_sess) {
228 		pr_err("Unable to allocate struct se_session from"
229 				" se_sess_cache\n");
230 		return ERR_PTR(-ENOMEM);
231 	}
232 	INIT_LIST_HEAD(&se_sess->sess_list);
233 	INIT_LIST_HEAD(&se_sess->sess_acl_list);
234 	INIT_LIST_HEAD(&se_sess->sess_cmd_list);
235 	spin_lock_init(&se_sess->sess_cmd_lock);
236 	kref_init(&se_sess->sess_kref);
237 
238 	return se_sess;
239 }
240 EXPORT_SYMBOL(transport_init_session);
241 
242 /*
243  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
244  */
245 void __transport_register_session(
246 	struct se_portal_group *se_tpg,
247 	struct se_node_acl *se_nacl,
248 	struct se_session *se_sess,
249 	void *fabric_sess_ptr)
250 {
251 	unsigned char buf[PR_REG_ISID_LEN];
252 
253 	se_sess->se_tpg = se_tpg;
254 	se_sess->fabric_sess_ptr = fabric_sess_ptr;
255 	/*
256 	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
257 	 *
258 	 * Only set for struct se_session's that will actually be moving I/O.
259 	 * eg: *NOT* discovery sessions.
260 	 */
261 	if (se_nacl) {
262 		/*
263 		 * If the fabric module supports an ISID based TransportID,
264 		 * save this value in binary from the fabric I_T Nexus now.
265 		 */
266 		if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
267 			memset(&buf[0], 0, PR_REG_ISID_LEN);
268 			se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
269 					&buf[0], PR_REG_ISID_LEN);
270 			se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
271 		}
272 		kref_get(&se_nacl->acl_kref);
273 
274 		spin_lock_irq(&se_nacl->nacl_sess_lock);
275 		/*
276 		 * The se_nacl->nacl_sess pointer will be set to the
277 		 * last active I_T Nexus for each struct se_node_acl.
278 		 */
279 		se_nacl->nacl_sess = se_sess;
280 
281 		list_add_tail(&se_sess->sess_acl_list,
282 			      &se_nacl->acl_sess_list);
283 		spin_unlock_irq(&se_nacl->nacl_sess_lock);
284 	}
285 	list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
286 
287 	pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
288 		se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
289 }
290 EXPORT_SYMBOL(__transport_register_session);
291 
292 void transport_register_session(
293 	struct se_portal_group *se_tpg,
294 	struct se_node_acl *se_nacl,
295 	struct se_session *se_sess,
296 	void *fabric_sess_ptr)
297 {
298 	unsigned long flags;
299 
300 	spin_lock_irqsave(&se_tpg->session_lock, flags);
301 	__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
302 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
303 }
304 EXPORT_SYMBOL(transport_register_session);
305 
306 void target_release_session(struct kref *kref)
307 {
308 	struct se_session *se_sess = container_of(kref,
309 			struct se_session, sess_kref);
310 	struct se_portal_group *se_tpg = se_sess->se_tpg;
311 
312 	se_tpg->se_tpg_tfo->close_session(se_sess);
313 }
314 
315 void target_get_session(struct se_session *se_sess)
316 {
317 	kref_get(&se_sess->sess_kref);
318 }
319 EXPORT_SYMBOL(target_get_session);
320 
321 void target_put_session(struct se_session *se_sess)
322 {
323 	struct se_portal_group *tpg = se_sess->se_tpg;
324 
325 	if (tpg->se_tpg_tfo->put_session != NULL) {
326 		tpg->se_tpg_tfo->put_session(se_sess);
327 		return;
328 	}
329 	kref_put(&se_sess->sess_kref, target_release_session);
330 }
331 EXPORT_SYMBOL(target_put_session);
332 
333 static void target_complete_nacl(struct kref *kref)
334 {
335 	struct se_node_acl *nacl = container_of(kref,
336 				struct se_node_acl, acl_kref);
337 
338 	complete(&nacl->acl_free_comp);
339 }
340 
341 void target_put_nacl(struct se_node_acl *nacl)
342 {
343 	kref_put(&nacl->acl_kref, target_complete_nacl);
344 }
345 
346 void transport_deregister_session_configfs(struct se_session *se_sess)
347 {
348 	struct se_node_acl *se_nacl;
349 	unsigned long flags;
350 	/*
351 	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
352 	 */
353 	se_nacl = se_sess->se_node_acl;
354 	if (se_nacl) {
355 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
356 		if (se_nacl->acl_stop == 0)
357 			list_del(&se_sess->sess_acl_list);
358 		/*
359 		 * If the session list is empty, then clear the pointer.
360 		 * Otherwise, set the struct se_session pointer from the tail
361 		 * element of the per struct se_node_acl active session list.
362 		 */
363 		if (list_empty(&se_nacl->acl_sess_list))
364 			se_nacl->nacl_sess = NULL;
365 		else {
366 			se_nacl->nacl_sess = container_of(
367 					se_nacl->acl_sess_list.prev,
368 					struct se_session, sess_acl_list);
369 		}
370 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
371 	}
372 }
373 EXPORT_SYMBOL(transport_deregister_session_configfs);
374 
375 void transport_free_session(struct se_session *se_sess)
376 {
377 	kmem_cache_free(se_sess_cache, se_sess);
378 }
379 EXPORT_SYMBOL(transport_free_session);
380 
381 void transport_deregister_session(struct se_session *se_sess)
382 {
383 	struct se_portal_group *se_tpg = se_sess->se_tpg;
384 	struct target_core_fabric_ops *se_tfo;
385 	struct se_node_acl *se_nacl;
386 	unsigned long flags;
387 	bool comp_nacl = true;
388 
389 	if (!se_tpg) {
390 		transport_free_session(se_sess);
391 		return;
392 	}
393 	se_tfo = se_tpg->se_tpg_tfo;
394 
395 	spin_lock_irqsave(&se_tpg->session_lock, flags);
396 	list_del(&se_sess->sess_list);
397 	se_sess->se_tpg = NULL;
398 	se_sess->fabric_sess_ptr = NULL;
399 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
400 
401 	/*
402 	 * Determine if we need to do extra work for this initiator node's
403 	 * struct se_node_acl if it had been previously dynamically generated.
404 	 */
405 	se_nacl = se_sess->se_node_acl;
406 
407 	spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
408 	if (se_nacl && se_nacl->dynamic_node_acl) {
409 		if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
410 			list_del(&se_nacl->acl_list);
411 			se_tpg->num_node_acls--;
412 			spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
413 			core_tpg_wait_for_nacl_pr_ref(se_nacl);
414 			core_free_device_list_for_node(se_nacl, se_tpg);
415 			se_tfo->tpg_release_fabric_acl(se_tpg, se_nacl);
416 
417 			comp_nacl = false;
418 			spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
419 		}
420 	}
421 	spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
422 
423 	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
424 		se_tpg->se_tpg_tfo->get_fabric_name());
425 	/*
426 	 * If last kref is dropping now for an explict NodeACL, awake sleeping
427 	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
428 	 * removal context.
429 	 */
430 	if (se_nacl && comp_nacl == true)
431 		target_put_nacl(se_nacl);
432 
433 	transport_free_session(se_sess);
434 }
435 EXPORT_SYMBOL(transport_deregister_session);
436 
437 /*
438  * Called with cmd->t_state_lock held.
439  */
440 static void target_remove_from_state_list(struct se_cmd *cmd)
441 {
442 	struct se_device *dev = cmd->se_dev;
443 	unsigned long flags;
444 
445 	if (!dev)
446 		return;
447 
448 	if (cmd->transport_state & CMD_T_BUSY)
449 		return;
450 
451 	spin_lock_irqsave(&dev->execute_task_lock, flags);
452 	if (cmd->state_active) {
453 		list_del(&cmd->state_list);
454 		cmd->state_active = false;
455 	}
456 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
457 }
458 
459 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists)
460 {
461 	unsigned long flags;
462 
463 	spin_lock_irqsave(&cmd->t_state_lock, flags);
464 	/*
465 	 * Determine if IOCTL context caller in requesting the stopping of this
466 	 * command for LUN shutdown purposes.
467 	 */
468 	if (cmd->transport_state & CMD_T_LUN_STOP) {
469 		pr_debug("%s:%d CMD_T_LUN_STOP for ITT: 0x%08x\n",
470 			__func__, __LINE__, cmd->se_tfo->get_task_tag(cmd));
471 
472 		cmd->transport_state &= ~CMD_T_ACTIVE;
473 		if (remove_from_lists)
474 			target_remove_from_state_list(cmd);
475 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
476 
477 		complete(&cmd->transport_lun_stop_comp);
478 		return 1;
479 	}
480 
481 	if (remove_from_lists) {
482 		target_remove_from_state_list(cmd);
483 
484 		/*
485 		 * Clear struct se_cmd->se_lun before the handoff to FE.
486 		 */
487 		cmd->se_lun = NULL;
488 	}
489 
490 	/*
491 	 * Determine if frontend context caller is requesting the stopping of
492 	 * this command for frontend exceptions.
493 	 */
494 	if (cmd->transport_state & CMD_T_STOP) {
495 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
496 			__func__, __LINE__,
497 			cmd->se_tfo->get_task_tag(cmd));
498 
499 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
500 
501 		complete(&cmd->t_transport_stop_comp);
502 		return 1;
503 	}
504 
505 	cmd->transport_state &= ~CMD_T_ACTIVE;
506 	if (remove_from_lists) {
507 		/*
508 		 * Some fabric modules like tcm_loop can release
509 		 * their internally allocated I/O reference now and
510 		 * struct se_cmd now.
511 		 *
512 		 * Fabric modules are expected to return '1' here if the
513 		 * se_cmd being passed is released at this point,
514 		 * or zero if not being released.
515 		 */
516 		if (cmd->se_tfo->check_stop_free != NULL) {
517 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
518 			return cmd->se_tfo->check_stop_free(cmd);
519 		}
520 	}
521 
522 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
523 	return 0;
524 }
525 
526 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
527 {
528 	return transport_cmd_check_stop(cmd, true);
529 }
530 
531 static void transport_lun_remove_cmd(struct se_cmd *cmd)
532 {
533 	struct se_lun *lun = cmd->se_lun;
534 	unsigned long flags;
535 
536 	if (!lun)
537 		return;
538 
539 	spin_lock_irqsave(&cmd->t_state_lock, flags);
540 	if (cmd->transport_state & CMD_T_DEV_ACTIVE) {
541 		cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
542 		target_remove_from_state_list(cmd);
543 	}
544 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
545 
546 	spin_lock_irqsave(&lun->lun_cmd_lock, flags);
547 	if (!list_empty(&cmd->se_lun_node))
548 		list_del_init(&cmd->se_lun_node);
549 	spin_unlock_irqrestore(&lun->lun_cmd_lock, flags);
550 }
551 
552 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
553 {
554 	if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
555 		transport_lun_remove_cmd(cmd);
556 
557 	if (transport_cmd_check_stop_to_fabric(cmd))
558 		return;
559 	if (remove)
560 		transport_put_cmd(cmd);
561 }
562 
563 static void target_complete_failure_work(struct work_struct *work)
564 {
565 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
566 
567 	transport_generic_request_failure(cmd);
568 }
569 
570 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
571 {
572 	struct se_device *dev = cmd->se_dev;
573 	int success = scsi_status == GOOD;
574 	unsigned long flags;
575 
576 	cmd->scsi_status = scsi_status;
577 
578 
579 	spin_lock_irqsave(&cmd->t_state_lock, flags);
580 	cmd->transport_state &= ~CMD_T_BUSY;
581 
582 	if (dev && dev->transport->transport_complete) {
583 		if (dev->transport->transport_complete(cmd,
584 				cmd->t_data_sg) != 0) {
585 			cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
586 			success = 1;
587 		}
588 	}
589 
590 	/*
591 	 * See if we are waiting to complete for an exception condition.
592 	 */
593 	if (cmd->transport_state & CMD_T_REQUEST_STOP) {
594 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
595 		complete(&cmd->task_stop_comp);
596 		return;
597 	}
598 
599 	if (!success)
600 		cmd->transport_state |= CMD_T_FAILED;
601 
602 	/*
603 	 * Check for case where an explict ABORT_TASK has been received
604 	 * and transport_wait_for_tasks() will be waiting for completion..
605 	 */
606 	if (cmd->transport_state & CMD_T_ABORTED &&
607 	    cmd->transport_state & CMD_T_STOP) {
608 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
609 		complete(&cmd->t_transport_stop_comp);
610 		return;
611 	} else if (cmd->transport_state & CMD_T_FAILED) {
612 		cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
613 		INIT_WORK(&cmd->work, target_complete_failure_work);
614 	} else {
615 		INIT_WORK(&cmd->work, target_complete_ok_work);
616 	}
617 
618 	cmd->t_state = TRANSPORT_COMPLETE;
619 	cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
620 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
621 
622 	queue_work(target_completion_wq, &cmd->work);
623 }
624 EXPORT_SYMBOL(target_complete_cmd);
625 
626 static void target_add_to_state_list(struct se_cmd *cmd)
627 {
628 	struct se_device *dev = cmd->se_dev;
629 	unsigned long flags;
630 
631 	spin_lock_irqsave(&dev->execute_task_lock, flags);
632 	if (!cmd->state_active) {
633 		list_add_tail(&cmd->state_list, &dev->state_list);
634 		cmd->state_active = true;
635 	}
636 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
637 }
638 
639 /*
640  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
641  */
642 static void transport_write_pending_qf(struct se_cmd *cmd);
643 static void transport_complete_qf(struct se_cmd *cmd);
644 
645 static void target_qf_do_work(struct work_struct *work)
646 {
647 	struct se_device *dev = container_of(work, struct se_device,
648 					qf_work_queue);
649 	LIST_HEAD(qf_cmd_list);
650 	struct se_cmd *cmd, *cmd_tmp;
651 
652 	spin_lock_irq(&dev->qf_cmd_lock);
653 	list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
654 	spin_unlock_irq(&dev->qf_cmd_lock);
655 
656 	list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
657 		list_del(&cmd->se_qf_node);
658 		atomic_dec(&dev->dev_qf_count);
659 		smp_mb__after_atomic_dec();
660 
661 		pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
662 			" context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
663 			(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
664 			(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
665 			: "UNKNOWN");
666 
667 		if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
668 			transport_write_pending_qf(cmd);
669 		else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
670 			transport_complete_qf(cmd);
671 	}
672 }
673 
674 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
675 {
676 	switch (cmd->data_direction) {
677 	case DMA_NONE:
678 		return "NONE";
679 	case DMA_FROM_DEVICE:
680 		return "READ";
681 	case DMA_TO_DEVICE:
682 		return "WRITE";
683 	case DMA_BIDIRECTIONAL:
684 		return "BIDI";
685 	default:
686 		break;
687 	}
688 
689 	return "UNKNOWN";
690 }
691 
692 void transport_dump_dev_state(
693 	struct se_device *dev,
694 	char *b,
695 	int *bl)
696 {
697 	*bl += sprintf(b + *bl, "Status: ");
698 	switch (dev->dev_status) {
699 	case TRANSPORT_DEVICE_ACTIVATED:
700 		*bl += sprintf(b + *bl, "ACTIVATED");
701 		break;
702 	case TRANSPORT_DEVICE_DEACTIVATED:
703 		*bl += sprintf(b + *bl, "DEACTIVATED");
704 		break;
705 	case TRANSPORT_DEVICE_SHUTDOWN:
706 		*bl += sprintf(b + *bl, "SHUTDOWN");
707 		break;
708 	case TRANSPORT_DEVICE_OFFLINE_ACTIVATED:
709 	case TRANSPORT_DEVICE_OFFLINE_DEACTIVATED:
710 		*bl += sprintf(b + *bl, "OFFLINE");
711 		break;
712 	default:
713 		*bl += sprintf(b + *bl, "UNKNOWN=%d", dev->dev_status);
714 		break;
715 	}
716 
717 	*bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
718 	*bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
719 		dev->se_sub_dev->se_dev_attrib.block_size,
720 		dev->se_sub_dev->se_dev_attrib.hw_max_sectors);
721 	*bl += sprintf(b + *bl, "        ");
722 }
723 
724 void transport_dump_vpd_proto_id(
725 	struct t10_vpd *vpd,
726 	unsigned char *p_buf,
727 	int p_buf_len)
728 {
729 	unsigned char buf[VPD_TMP_BUF_SIZE];
730 	int len;
731 
732 	memset(buf, 0, VPD_TMP_BUF_SIZE);
733 	len = sprintf(buf, "T10 VPD Protocol Identifier: ");
734 
735 	switch (vpd->protocol_identifier) {
736 	case 0x00:
737 		sprintf(buf+len, "Fibre Channel\n");
738 		break;
739 	case 0x10:
740 		sprintf(buf+len, "Parallel SCSI\n");
741 		break;
742 	case 0x20:
743 		sprintf(buf+len, "SSA\n");
744 		break;
745 	case 0x30:
746 		sprintf(buf+len, "IEEE 1394\n");
747 		break;
748 	case 0x40:
749 		sprintf(buf+len, "SCSI Remote Direct Memory Access"
750 				" Protocol\n");
751 		break;
752 	case 0x50:
753 		sprintf(buf+len, "Internet SCSI (iSCSI)\n");
754 		break;
755 	case 0x60:
756 		sprintf(buf+len, "SAS Serial SCSI Protocol\n");
757 		break;
758 	case 0x70:
759 		sprintf(buf+len, "Automation/Drive Interface Transport"
760 				" Protocol\n");
761 		break;
762 	case 0x80:
763 		sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
764 		break;
765 	default:
766 		sprintf(buf+len, "Unknown 0x%02x\n",
767 				vpd->protocol_identifier);
768 		break;
769 	}
770 
771 	if (p_buf)
772 		strncpy(p_buf, buf, p_buf_len);
773 	else
774 		pr_debug("%s", buf);
775 }
776 
777 void
778 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
779 {
780 	/*
781 	 * Check if the Protocol Identifier Valid (PIV) bit is set..
782 	 *
783 	 * from spc3r23.pdf section 7.5.1
784 	 */
785 	 if (page_83[1] & 0x80) {
786 		vpd->protocol_identifier = (page_83[0] & 0xf0);
787 		vpd->protocol_identifier_set = 1;
788 		transport_dump_vpd_proto_id(vpd, NULL, 0);
789 	}
790 }
791 EXPORT_SYMBOL(transport_set_vpd_proto_id);
792 
793 int transport_dump_vpd_assoc(
794 	struct t10_vpd *vpd,
795 	unsigned char *p_buf,
796 	int p_buf_len)
797 {
798 	unsigned char buf[VPD_TMP_BUF_SIZE];
799 	int ret = 0;
800 	int len;
801 
802 	memset(buf, 0, VPD_TMP_BUF_SIZE);
803 	len = sprintf(buf, "T10 VPD Identifier Association: ");
804 
805 	switch (vpd->association) {
806 	case 0x00:
807 		sprintf(buf+len, "addressed logical unit\n");
808 		break;
809 	case 0x10:
810 		sprintf(buf+len, "target port\n");
811 		break;
812 	case 0x20:
813 		sprintf(buf+len, "SCSI target device\n");
814 		break;
815 	default:
816 		sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
817 		ret = -EINVAL;
818 		break;
819 	}
820 
821 	if (p_buf)
822 		strncpy(p_buf, buf, p_buf_len);
823 	else
824 		pr_debug("%s", buf);
825 
826 	return ret;
827 }
828 
829 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
830 {
831 	/*
832 	 * The VPD identification association..
833 	 *
834 	 * from spc3r23.pdf Section 7.6.3.1 Table 297
835 	 */
836 	vpd->association = (page_83[1] & 0x30);
837 	return transport_dump_vpd_assoc(vpd, NULL, 0);
838 }
839 EXPORT_SYMBOL(transport_set_vpd_assoc);
840 
841 int transport_dump_vpd_ident_type(
842 	struct t10_vpd *vpd,
843 	unsigned char *p_buf,
844 	int p_buf_len)
845 {
846 	unsigned char buf[VPD_TMP_BUF_SIZE];
847 	int ret = 0;
848 	int len;
849 
850 	memset(buf, 0, VPD_TMP_BUF_SIZE);
851 	len = sprintf(buf, "T10 VPD Identifier Type: ");
852 
853 	switch (vpd->device_identifier_type) {
854 	case 0x00:
855 		sprintf(buf+len, "Vendor specific\n");
856 		break;
857 	case 0x01:
858 		sprintf(buf+len, "T10 Vendor ID based\n");
859 		break;
860 	case 0x02:
861 		sprintf(buf+len, "EUI-64 based\n");
862 		break;
863 	case 0x03:
864 		sprintf(buf+len, "NAA\n");
865 		break;
866 	case 0x04:
867 		sprintf(buf+len, "Relative target port identifier\n");
868 		break;
869 	case 0x08:
870 		sprintf(buf+len, "SCSI name string\n");
871 		break;
872 	default:
873 		sprintf(buf+len, "Unsupported: 0x%02x\n",
874 				vpd->device_identifier_type);
875 		ret = -EINVAL;
876 		break;
877 	}
878 
879 	if (p_buf) {
880 		if (p_buf_len < strlen(buf)+1)
881 			return -EINVAL;
882 		strncpy(p_buf, buf, p_buf_len);
883 	} else {
884 		pr_debug("%s", buf);
885 	}
886 
887 	return ret;
888 }
889 
890 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
891 {
892 	/*
893 	 * The VPD identifier type..
894 	 *
895 	 * from spc3r23.pdf Section 7.6.3.1 Table 298
896 	 */
897 	vpd->device_identifier_type = (page_83[1] & 0x0f);
898 	return transport_dump_vpd_ident_type(vpd, NULL, 0);
899 }
900 EXPORT_SYMBOL(transport_set_vpd_ident_type);
901 
902 int transport_dump_vpd_ident(
903 	struct t10_vpd *vpd,
904 	unsigned char *p_buf,
905 	int p_buf_len)
906 {
907 	unsigned char buf[VPD_TMP_BUF_SIZE];
908 	int ret = 0;
909 
910 	memset(buf, 0, VPD_TMP_BUF_SIZE);
911 
912 	switch (vpd->device_identifier_code_set) {
913 	case 0x01: /* Binary */
914 		sprintf(buf, "T10 VPD Binary Device Identifier: %s\n",
915 			&vpd->device_identifier[0]);
916 		break;
917 	case 0x02: /* ASCII */
918 		sprintf(buf, "T10 VPD ASCII Device Identifier: %s\n",
919 			&vpd->device_identifier[0]);
920 		break;
921 	case 0x03: /* UTF-8 */
922 		sprintf(buf, "T10 VPD UTF-8 Device Identifier: %s\n",
923 			&vpd->device_identifier[0]);
924 		break;
925 	default:
926 		sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
927 			" 0x%02x", vpd->device_identifier_code_set);
928 		ret = -EINVAL;
929 		break;
930 	}
931 
932 	if (p_buf)
933 		strncpy(p_buf, buf, p_buf_len);
934 	else
935 		pr_debug("%s", buf);
936 
937 	return ret;
938 }
939 
940 int
941 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
942 {
943 	static const char hex_str[] = "0123456789abcdef";
944 	int j = 0, i = 4; /* offset to start of the identifer */
945 
946 	/*
947 	 * The VPD Code Set (encoding)
948 	 *
949 	 * from spc3r23.pdf Section 7.6.3.1 Table 296
950 	 */
951 	vpd->device_identifier_code_set = (page_83[0] & 0x0f);
952 	switch (vpd->device_identifier_code_set) {
953 	case 0x01: /* Binary */
954 		vpd->device_identifier[j++] =
955 				hex_str[vpd->device_identifier_type];
956 		while (i < (4 + page_83[3])) {
957 			vpd->device_identifier[j++] =
958 				hex_str[(page_83[i] & 0xf0) >> 4];
959 			vpd->device_identifier[j++] =
960 				hex_str[page_83[i] & 0x0f];
961 			i++;
962 		}
963 		break;
964 	case 0x02: /* ASCII */
965 	case 0x03: /* UTF-8 */
966 		while (i < (4 + page_83[3]))
967 			vpd->device_identifier[j++] = page_83[i++];
968 		break;
969 	default:
970 		break;
971 	}
972 
973 	return transport_dump_vpd_ident(vpd, NULL, 0);
974 }
975 EXPORT_SYMBOL(transport_set_vpd_ident);
976 
977 static void core_setup_task_attr_emulation(struct se_device *dev)
978 {
979 	/*
980 	 * If this device is from Target_Core_Mod/pSCSI, disable the
981 	 * SAM Task Attribute emulation.
982 	 *
983 	 * This is currently not available in upsream Linux/SCSI Target
984 	 * mode code, and is assumed to be disabled while using TCM/pSCSI.
985 	 */
986 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV) {
987 		dev->dev_task_attr_type = SAM_TASK_ATTR_PASSTHROUGH;
988 		return;
989 	}
990 
991 	dev->dev_task_attr_type = SAM_TASK_ATTR_EMULATED;
992 	pr_debug("%s: Using SAM_TASK_ATTR_EMULATED for SPC: 0x%02x"
993 		" device\n", dev->transport->name,
994 		dev->transport->get_device_rev(dev));
995 }
996 
997 static void scsi_dump_inquiry(struct se_device *dev)
998 {
999 	struct t10_wwn *wwn = &dev->se_sub_dev->t10_wwn;
1000 	char buf[17];
1001 	int i, device_type;
1002 	/*
1003 	 * Print Linux/SCSI style INQUIRY formatting to the kernel ring buffer
1004 	 */
1005 	for (i = 0; i < 8; i++)
1006 		if (wwn->vendor[i] >= 0x20)
1007 			buf[i] = wwn->vendor[i];
1008 		else
1009 			buf[i] = ' ';
1010 	buf[i] = '\0';
1011 	pr_debug("  Vendor: %s\n", buf);
1012 
1013 	for (i = 0; i < 16; i++)
1014 		if (wwn->model[i] >= 0x20)
1015 			buf[i] = wwn->model[i];
1016 		else
1017 			buf[i] = ' ';
1018 	buf[i] = '\0';
1019 	pr_debug("  Model: %s\n", buf);
1020 
1021 	for (i = 0; i < 4; i++)
1022 		if (wwn->revision[i] >= 0x20)
1023 			buf[i] = wwn->revision[i];
1024 		else
1025 			buf[i] = ' ';
1026 	buf[i] = '\0';
1027 	pr_debug("  Revision: %s\n", buf);
1028 
1029 	device_type = dev->transport->get_device_type(dev);
1030 	pr_debug("  Type:   %s ", scsi_device_type(device_type));
1031 	pr_debug("                 ANSI SCSI revision: %02x\n",
1032 				dev->transport->get_device_rev(dev));
1033 }
1034 
1035 struct se_device *transport_add_device_to_core_hba(
1036 	struct se_hba *hba,
1037 	struct se_subsystem_api *transport,
1038 	struct se_subsystem_dev *se_dev,
1039 	u32 device_flags,
1040 	void *transport_dev,
1041 	struct se_dev_limits *dev_limits,
1042 	const char *inquiry_prod,
1043 	const char *inquiry_rev)
1044 {
1045 	int force_pt;
1046 	struct se_device  *dev;
1047 
1048 	dev = kzalloc(sizeof(struct se_device), GFP_KERNEL);
1049 	if (!dev) {
1050 		pr_err("Unable to allocate memory for se_dev_t\n");
1051 		return NULL;
1052 	}
1053 
1054 	dev->dev_flags		= device_flags;
1055 	dev->dev_status		|= TRANSPORT_DEVICE_DEACTIVATED;
1056 	dev->dev_ptr		= transport_dev;
1057 	dev->se_hba		= hba;
1058 	dev->se_sub_dev		= se_dev;
1059 	dev->transport		= transport;
1060 	INIT_LIST_HEAD(&dev->dev_list);
1061 	INIT_LIST_HEAD(&dev->dev_sep_list);
1062 	INIT_LIST_HEAD(&dev->dev_tmr_list);
1063 	INIT_LIST_HEAD(&dev->delayed_cmd_list);
1064 	INIT_LIST_HEAD(&dev->state_list);
1065 	INIT_LIST_HEAD(&dev->qf_cmd_list);
1066 	spin_lock_init(&dev->execute_task_lock);
1067 	spin_lock_init(&dev->delayed_cmd_lock);
1068 	spin_lock_init(&dev->dev_reservation_lock);
1069 	spin_lock_init(&dev->dev_status_lock);
1070 	spin_lock_init(&dev->se_port_lock);
1071 	spin_lock_init(&dev->se_tmr_lock);
1072 	spin_lock_init(&dev->qf_cmd_lock);
1073 	atomic_set(&dev->dev_ordered_id, 0);
1074 
1075 	se_dev_set_default_attribs(dev, dev_limits);
1076 
1077 	dev->dev_index = scsi_get_new_index(SCSI_DEVICE_INDEX);
1078 	dev->creation_time = get_jiffies_64();
1079 	spin_lock_init(&dev->stats_lock);
1080 
1081 	spin_lock(&hba->device_lock);
1082 	list_add_tail(&dev->dev_list, &hba->hba_dev_list);
1083 	hba->dev_count++;
1084 	spin_unlock(&hba->device_lock);
1085 	/*
1086 	 * Setup the SAM Task Attribute emulation for struct se_device
1087 	 */
1088 	core_setup_task_attr_emulation(dev);
1089 	/*
1090 	 * Force PR and ALUA passthrough emulation with internal object use.
1091 	 */
1092 	force_pt = (hba->hba_flags & HBA_FLAGS_INTERNAL_USE);
1093 	/*
1094 	 * Setup the Reservations infrastructure for struct se_device
1095 	 */
1096 	core_setup_reservations(dev, force_pt);
1097 	/*
1098 	 * Setup the Asymmetric Logical Unit Assignment for struct se_device
1099 	 */
1100 	if (core_setup_alua(dev, force_pt) < 0)
1101 		goto err_dev_list;
1102 
1103 	/*
1104 	 * Startup the struct se_device processing thread
1105 	 */
1106 	dev->tmr_wq = alloc_workqueue("tmr-%s", WQ_MEM_RECLAIM | WQ_UNBOUND, 1,
1107 				      dev->transport->name);
1108 	if (!dev->tmr_wq) {
1109 		pr_err("Unable to create tmr workqueue for %s\n",
1110 			dev->transport->name);
1111 		goto err_dev_list;
1112 	}
1113 	/*
1114 	 * Setup work_queue for QUEUE_FULL
1115 	 */
1116 	INIT_WORK(&dev->qf_work_queue, target_qf_do_work);
1117 	/*
1118 	 * Preload the initial INQUIRY const values if we are doing
1119 	 * anything virtual (IBLOCK, FILEIO, RAMDISK), but not for TCM/pSCSI
1120 	 * passthrough because this is being provided by the backend LLD.
1121 	 * This is required so that transport_get_inquiry() copies these
1122 	 * originals once back into DEV_T10_WWN(dev) for the virtual device
1123 	 * setup.
1124 	 */
1125 	if (dev->transport->transport_type != TRANSPORT_PLUGIN_PHBA_PDEV) {
1126 		if (!inquiry_prod || !inquiry_rev) {
1127 			pr_err("All non TCM/pSCSI plugins require"
1128 				" INQUIRY consts\n");
1129 			goto err_wq;
1130 		}
1131 
1132 		strncpy(&dev->se_sub_dev->t10_wwn.vendor[0], "LIO-ORG", 8);
1133 		strncpy(&dev->se_sub_dev->t10_wwn.model[0], inquiry_prod, 16);
1134 		strncpy(&dev->se_sub_dev->t10_wwn.revision[0], inquiry_rev, 4);
1135 	}
1136 	scsi_dump_inquiry(dev);
1137 
1138 	return dev;
1139 
1140 err_wq:
1141 	destroy_workqueue(dev->tmr_wq);
1142 err_dev_list:
1143 	spin_lock(&hba->device_lock);
1144 	list_del(&dev->dev_list);
1145 	hba->dev_count--;
1146 	spin_unlock(&hba->device_lock);
1147 
1148 	se_release_vpd_for_dev(dev);
1149 
1150 	kfree(dev);
1151 
1152 	return NULL;
1153 }
1154 EXPORT_SYMBOL(transport_add_device_to_core_hba);
1155 
1156 int target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1157 {
1158 	struct se_device *dev = cmd->se_dev;
1159 
1160 	if (cmd->unknown_data_length) {
1161 		cmd->data_length = size;
1162 	} else if (size != cmd->data_length) {
1163 		pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1164 			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
1165 			" 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1166 				cmd->data_length, size, cmd->t_task_cdb[0]);
1167 
1168 		cmd->cmd_spdtl = size;
1169 
1170 		if (cmd->data_direction == DMA_TO_DEVICE) {
1171 			pr_err("Rejecting underflow/overflow"
1172 					" WRITE data\n");
1173 			goto out_invalid_cdb_field;
1174 		}
1175 		/*
1176 		 * Reject READ_* or WRITE_* with overflow/underflow for
1177 		 * type SCF_SCSI_DATA_CDB.
1178 		 */
1179 		if (dev->se_sub_dev->se_dev_attrib.block_size != 512)  {
1180 			pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1181 				" CDB on non 512-byte sector setup subsystem"
1182 				" plugin: %s\n", dev->transport->name);
1183 			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1184 			goto out_invalid_cdb_field;
1185 		}
1186 
1187 		if (size > cmd->data_length) {
1188 			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1189 			cmd->residual_count = (size - cmd->data_length);
1190 		} else {
1191 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1192 			cmd->residual_count = (cmd->data_length - size);
1193 		}
1194 		cmd->data_length = size;
1195 	}
1196 
1197 	return 0;
1198 
1199 out_invalid_cdb_field:
1200 	cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1201 	cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
1202 	return -EINVAL;
1203 }
1204 
1205 /*
1206  * Used by fabric modules containing a local struct se_cmd within their
1207  * fabric dependent per I/O descriptor.
1208  */
1209 void transport_init_se_cmd(
1210 	struct se_cmd *cmd,
1211 	struct target_core_fabric_ops *tfo,
1212 	struct se_session *se_sess,
1213 	u32 data_length,
1214 	int data_direction,
1215 	int task_attr,
1216 	unsigned char *sense_buffer)
1217 {
1218 	INIT_LIST_HEAD(&cmd->se_lun_node);
1219 	INIT_LIST_HEAD(&cmd->se_delayed_node);
1220 	INIT_LIST_HEAD(&cmd->se_qf_node);
1221 	INIT_LIST_HEAD(&cmd->se_cmd_list);
1222 	INIT_LIST_HEAD(&cmd->state_list);
1223 	init_completion(&cmd->transport_lun_fe_stop_comp);
1224 	init_completion(&cmd->transport_lun_stop_comp);
1225 	init_completion(&cmd->t_transport_stop_comp);
1226 	init_completion(&cmd->cmd_wait_comp);
1227 	init_completion(&cmd->task_stop_comp);
1228 	spin_lock_init(&cmd->t_state_lock);
1229 	cmd->transport_state = CMD_T_DEV_ACTIVE;
1230 
1231 	cmd->se_tfo = tfo;
1232 	cmd->se_sess = se_sess;
1233 	cmd->data_length = data_length;
1234 	cmd->data_direction = data_direction;
1235 	cmd->sam_task_attr = task_attr;
1236 	cmd->sense_buffer = sense_buffer;
1237 
1238 	cmd->state_active = false;
1239 }
1240 EXPORT_SYMBOL(transport_init_se_cmd);
1241 
1242 static int transport_check_alloc_task_attr(struct se_cmd *cmd)
1243 {
1244 	/*
1245 	 * Check if SAM Task Attribute emulation is enabled for this
1246 	 * struct se_device storage object
1247 	 */
1248 	if (cmd->se_dev->dev_task_attr_type != SAM_TASK_ATTR_EMULATED)
1249 		return 0;
1250 
1251 	if (cmd->sam_task_attr == MSG_ACA_TAG) {
1252 		pr_debug("SAM Task Attribute ACA"
1253 			" emulation is not supported\n");
1254 		return -EINVAL;
1255 	}
1256 	/*
1257 	 * Used to determine when ORDERED commands should go from
1258 	 * Dormant to Active status.
1259 	 */
1260 	cmd->se_ordered_id = atomic_inc_return(&cmd->se_dev->dev_ordered_id);
1261 	smp_mb__after_atomic_inc();
1262 	pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
1263 			cmd->se_ordered_id, cmd->sam_task_attr,
1264 			cmd->se_dev->transport->name);
1265 	return 0;
1266 }
1267 
1268 /*	target_setup_cmd_from_cdb():
1269  *
1270  *	Called from fabric RX Thread.
1271  */
1272 int target_setup_cmd_from_cdb(
1273 	struct se_cmd *cmd,
1274 	unsigned char *cdb)
1275 {
1276 	struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
1277 	u32 pr_reg_type = 0;
1278 	u8 alua_ascq = 0;
1279 	unsigned long flags;
1280 	int ret;
1281 
1282 	/*
1283 	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1284 	 * for VARIABLE_LENGTH_CMD
1285 	 */
1286 	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1287 		pr_err("Received SCSI CDB with command_size: %d that"
1288 			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1289 			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1290 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1291 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
1292 		return -EINVAL;
1293 	}
1294 	/*
1295 	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1296 	 * allocate the additional extended CDB buffer now..  Otherwise
1297 	 * setup the pointer from __t_task_cdb to t_task_cdb.
1298 	 */
1299 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1300 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1301 						GFP_KERNEL);
1302 		if (!cmd->t_task_cdb) {
1303 			pr_err("Unable to allocate cmd->t_task_cdb"
1304 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1305 				scsi_command_size(cdb),
1306 				(unsigned long)sizeof(cmd->__t_task_cdb));
1307 			cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1308 			cmd->scsi_sense_reason =
1309 					TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1310 			return -ENOMEM;
1311 		}
1312 	} else
1313 		cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1314 	/*
1315 	 * Copy the original CDB into cmd->
1316 	 */
1317 	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1318 
1319 	/*
1320 	 * Check for an existing UNIT ATTENTION condition
1321 	 */
1322 	if (core_scsi3_ua_check(cmd, cdb) < 0) {
1323 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1324 		cmd->scsi_sense_reason = TCM_CHECK_CONDITION_UNIT_ATTENTION;
1325 		return -EINVAL;
1326 	}
1327 
1328 	ret = su_dev->t10_alua.alua_state_check(cmd, cdb, &alua_ascq);
1329 	if (ret != 0) {
1330 		/*
1331 		 * Set SCSI additional sense code (ASC) to 'LUN Not Accessible';
1332 		 * The ALUA additional sense code qualifier (ASCQ) is determined
1333 		 * by the ALUA primary or secondary access state..
1334 		 */
1335 		if (ret > 0) {
1336 			pr_debug("[%s]: ALUA TG Port not available, "
1337 				"SenseKey: NOT_READY, ASC/ASCQ: "
1338 				"0x04/0x%02x\n",
1339 				cmd->se_tfo->get_fabric_name(), alua_ascq);
1340 
1341 			transport_set_sense_codes(cmd, 0x04, alua_ascq);
1342 			cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1343 			cmd->scsi_sense_reason = TCM_CHECK_CONDITION_NOT_READY;
1344 			return -EINVAL;
1345 		}
1346 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1347 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
1348 		return -EINVAL;
1349 	}
1350 
1351 	/*
1352 	 * Check status for SPC-3 Persistent Reservations
1353 	 */
1354 	if (su_dev->t10_pr.pr_ops.t10_reservation_check(cmd, &pr_reg_type)) {
1355 		if (su_dev->t10_pr.pr_ops.t10_seq_non_holder(
1356 					cmd, cdb, pr_reg_type) != 0) {
1357 			cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1358 			cmd->se_cmd_flags |= SCF_SCSI_RESERVATION_CONFLICT;
1359 			cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1360 			cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
1361 			return -EBUSY;
1362 		}
1363 		/*
1364 		 * This means the CDB is allowed for the SCSI Initiator port
1365 		 * when said port is *NOT* holding the legacy SPC-2 or
1366 		 * SPC-3 Persistent Reservation.
1367 		 */
1368 	}
1369 
1370 	ret = cmd->se_dev->transport->parse_cdb(cmd);
1371 	if (ret < 0)
1372 		return ret;
1373 
1374 	spin_lock_irqsave(&cmd->t_state_lock, flags);
1375 	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1376 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1377 
1378 	/*
1379 	 * Check for SAM Task Attribute Emulation
1380 	 */
1381 	if (transport_check_alloc_task_attr(cmd) < 0) {
1382 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1383 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
1384 		return -EINVAL;
1385 	}
1386 	spin_lock(&cmd->se_lun->lun_sep_lock);
1387 	if (cmd->se_lun->lun_sep)
1388 		cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
1389 	spin_unlock(&cmd->se_lun->lun_sep_lock);
1390 	return 0;
1391 }
1392 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1393 
1394 /*
1395  * Used by fabric module frontends to queue tasks directly.
1396  * Many only be used from process context only
1397  */
1398 int transport_handle_cdb_direct(
1399 	struct se_cmd *cmd)
1400 {
1401 	int ret;
1402 
1403 	if (!cmd->se_lun) {
1404 		dump_stack();
1405 		pr_err("cmd->se_lun is NULL\n");
1406 		return -EINVAL;
1407 	}
1408 	if (in_interrupt()) {
1409 		dump_stack();
1410 		pr_err("transport_generic_handle_cdb cannot be called"
1411 				" from interrupt context\n");
1412 		return -EINVAL;
1413 	}
1414 	/*
1415 	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1416 	 * outstanding descriptors are handled correctly during shutdown via
1417 	 * transport_wait_for_tasks()
1418 	 *
1419 	 * Also, we don't take cmd->t_state_lock here as we only expect
1420 	 * this to be called for initial descriptor submission.
1421 	 */
1422 	cmd->t_state = TRANSPORT_NEW_CMD;
1423 	cmd->transport_state |= CMD_T_ACTIVE;
1424 
1425 	/*
1426 	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1427 	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1428 	 * and call transport_generic_request_failure() if necessary..
1429 	 */
1430 	ret = transport_generic_new_cmd(cmd);
1431 	if (ret < 0)
1432 		transport_generic_request_failure(cmd);
1433 
1434 	return 0;
1435 }
1436 EXPORT_SYMBOL(transport_handle_cdb_direct);
1437 
1438 /**
1439  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1440  *
1441  * @se_cmd: command descriptor to submit
1442  * @se_sess: associated se_sess for endpoint
1443  * @cdb: pointer to SCSI CDB
1444  * @sense: pointer to SCSI sense buffer
1445  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1446  * @data_length: fabric expected data transfer length
1447  * @task_addr: SAM task attribute
1448  * @data_dir: DMA data direction
1449  * @flags: flags for command submission from target_sc_flags_tables
1450  *
1451  * Returns non zero to signal active I/O shutdown failure.  All other
1452  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1453  * but still return zero here.
1454  *
1455  * This may only be called from process context, and also currently
1456  * assumes internal allocation of fabric payload buffer by target-core.
1457  **/
1458 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1459 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1460 		u32 data_length, int task_attr, int data_dir, int flags)
1461 {
1462 	struct se_portal_group *se_tpg;
1463 	int rc;
1464 
1465 	se_tpg = se_sess->se_tpg;
1466 	BUG_ON(!se_tpg);
1467 	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1468 	BUG_ON(in_interrupt());
1469 	/*
1470 	 * Initialize se_cmd for target operation.  From this point
1471 	 * exceptions are handled by sending exception status via
1472 	 * target_core_fabric_ops->queue_status() callback
1473 	 */
1474 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1475 				data_length, data_dir, task_attr, sense);
1476 	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1477 		se_cmd->unknown_data_length = 1;
1478 	/*
1479 	 * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1480 	 * se_sess->sess_cmd_list.  A second kref_get here is necessary
1481 	 * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1482 	 * kref_put() to happen during fabric packet acknowledgement.
1483 	 */
1484 	rc = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1485 	if (rc)
1486 		return rc;
1487 	/*
1488 	 * Signal bidirectional data payloads to target-core
1489 	 */
1490 	if (flags & TARGET_SCF_BIDI_OP)
1491 		se_cmd->se_cmd_flags |= SCF_BIDI;
1492 	/*
1493 	 * Locate se_lun pointer and attach it to struct se_cmd
1494 	 */
1495 	if (transport_lookup_cmd_lun(se_cmd, unpacked_lun) < 0) {
1496 		transport_send_check_condition_and_sense(se_cmd,
1497 				se_cmd->scsi_sense_reason, 0);
1498 		target_put_sess_cmd(se_sess, se_cmd);
1499 		return 0;
1500 	}
1501 
1502 	rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1503 	if (rc != 0) {
1504 		transport_generic_request_failure(se_cmd);
1505 		return 0;
1506 	}
1507 
1508 	/*
1509 	 * Check if we need to delay processing because of ALUA
1510 	 * Active/NonOptimized primary access state..
1511 	 */
1512 	core_alua_check_nonop_delay(se_cmd);
1513 
1514 	transport_handle_cdb_direct(se_cmd);
1515 	return 0;
1516 }
1517 EXPORT_SYMBOL(target_submit_cmd);
1518 
1519 static void target_complete_tmr_failure(struct work_struct *work)
1520 {
1521 	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1522 
1523 	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1524 	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1525 	transport_generic_free_cmd(se_cmd, 0);
1526 }
1527 
1528 /**
1529  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1530  *                     for TMR CDBs
1531  *
1532  * @se_cmd: command descriptor to submit
1533  * @se_sess: associated se_sess for endpoint
1534  * @sense: pointer to SCSI sense buffer
1535  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1536  * @fabric_context: fabric context for TMR req
1537  * @tm_type: Type of TM request
1538  * @gfp: gfp type for caller
1539  * @tag: referenced task tag for TMR_ABORT_TASK
1540  * @flags: submit cmd flags
1541  *
1542  * Callable from all contexts.
1543  **/
1544 
1545 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1546 		unsigned char *sense, u32 unpacked_lun,
1547 		void *fabric_tmr_ptr, unsigned char tm_type,
1548 		gfp_t gfp, unsigned int tag, int flags)
1549 {
1550 	struct se_portal_group *se_tpg;
1551 	int ret;
1552 
1553 	se_tpg = se_sess->se_tpg;
1554 	BUG_ON(!se_tpg);
1555 
1556 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1557 			      0, DMA_NONE, MSG_SIMPLE_TAG, sense);
1558 	/*
1559 	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1560 	 * allocation failure.
1561 	 */
1562 	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1563 	if (ret < 0)
1564 		return -ENOMEM;
1565 
1566 	if (tm_type == TMR_ABORT_TASK)
1567 		se_cmd->se_tmr_req->ref_task_tag = tag;
1568 
1569 	/* See target_submit_cmd for commentary */
1570 	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1571 	if (ret) {
1572 		core_tmr_release_req(se_cmd->se_tmr_req);
1573 		return ret;
1574 	}
1575 
1576 	ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1577 	if (ret) {
1578 		/*
1579 		 * For callback during failure handling, push this work off
1580 		 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1581 		 */
1582 		INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1583 		schedule_work(&se_cmd->work);
1584 		return 0;
1585 	}
1586 	transport_generic_handle_tmr(se_cmd);
1587 	return 0;
1588 }
1589 EXPORT_SYMBOL(target_submit_tmr);
1590 
1591 /*
1592  * If the cmd is active, request it to be stopped and sleep until it
1593  * has completed.
1594  */
1595 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1596 {
1597 	bool was_active = false;
1598 
1599 	if (cmd->transport_state & CMD_T_BUSY) {
1600 		cmd->transport_state |= CMD_T_REQUEST_STOP;
1601 		spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1602 
1603 		pr_debug("cmd %p waiting to complete\n", cmd);
1604 		wait_for_completion(&cmd->task_stop_comp);
1605 		pr_debug("cmd %p stopped successfully\n", cmd);
1606 
1607 		spin_lock_irqsave(&cmd->t_state_lock, *flags);
1608 		cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1609 		cmd->transport_state &= ~CMD_T_BUSY;
1610 		was_active = true;
1611 	}
1612 
1613 	return was_active;
1614 }
1615 
1616 /*
1617  * Handle SAM-esque emulation for generic transport request failures.
1618  */
1619 void transport_generic_request_failure(struct se_cmd *cmd)
1620 {
1621 	int ret = 0;
1622 
1623 	pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
1624 		" CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
1625 		cmd->t_task_cdb[0]);
1626 	pr_debug("-----[ i_state: %d t_state: %d scsi_sense_reason: %d\n",
1627 		cmd->se_tfo->get_cmd_state(cmd),
1628 		cmd->t_state, cmd->scsi_sense_reason);
1629 	pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1630 		(cmd->transport_state & CMD_T_ACTIVE) != 0,
1631 		(cmd->transport_state & CMD_T_STOP) != 0,
1632 		(cmd->transport_state & CMD_T_SENT) != 0);
1633 
1634 	/*
1635 	 * For SAM Task Attribute emulation for failed struct se_cmd
1636 	 */
1637 	if (cmd->se_dev->dev_task_attr_type == SAM_TASK_ATTR_EMULATED)
1638 		transport_complete_task_attr(cmd);
1639 
1640 	switch (cmd->scsi_sense_reason) {
1641 	case TCM_NON_EXISTENT_LUN:
1642 	case TCM_UNSUPPORTED_SCSI_OPCODE:
1643 	case TCM_INVALID_CDB_FIELD:
1644 	case TCM_INVALID_PARAMETER_LIST:
1645 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1646 	case TCM_UNKNOWN_MODE_PAGE:
1647 	case TCM_WRITE_PROTECTED:
1648 	case TCM_ADDRESS_OUT_OF_RANGE:
1649 	case TCM_CHECK_CONDITION_ABORT_CMD:
1650 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1651 	case TCM_CHECK_CONDITION_NOT_READY:
1652 		break;
1653 	case TCM_RESERVATION_CONFLICT:
1654 		/*
1655 		 * No SENSE Data payload for this case, set SCSI Status
1656 		 * and queue the response to $FABRIC_MOD.
1657 		 *
1658 		 * Uses linux/include/scsi/scsi.h SAM status codes defs
1659 		 */
1660 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1661 		/*
1662 		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1663 		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1664 		 * CONFLICT STATUS.
1665 		 *
1666 		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1667 		 */
1668 		if (cmd->se_sess &&
1669 		    cmd->se_dev->se_sub_dev->se_dev_attrib.emulate_ua_intlck_ctrl == 2)
1670 			core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
1671 				cmd->orig_fe_lun, 0x2C,
1672 				ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1673 
1674 		ret = cmd->se_tfo->queue_status(cmd);
1675 		if (ret == -EAGAIN || ret == -ENOMEM)
1676 			goto queue_full;
1677 		goto check_stop;
1678 	default:
1679 		pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1680 			cmd->t_task_cdb[0], cmd->scsi_sense_reason);
1681 		cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1682 		break;
1683 	}
1684 
1685 	ret = transport_send_check_condition_and_sense(cmd,
1686 			cmd->scsi_sense_reason, 0);
1687 	if (ret == -EAGAIN || ret == -ENOMEM)
1688 		goto queue_full;
1689 
1690 check_stop:
1691 	transport_lun_remove_cmd(cmd);
1692 	if (!transport_cmd_check_stop_to_fabric(cmd))
1693 		;
1694 	return;
1695 
1696 queue_full:
1697 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1698 	transport_handle_queue_full(cmd, cmd->se_dev);
1699 }
1700 EXPORT_SYMBOL(transport_generic_request_failure);
1701 
1702 static void __target_execute_cmd(struct se_cmd *cmd)
1703 {
1704 	int error = 0;
1705 
1706 	spin_lock_irq(&cmd->t_state_lock);
1707 	cmd->transport_state |= (CMD_T_BUSY|CMD_T_SENT);
1708 	spin_unlock_irq(&cmd->t_state_lock);
1709 
1710 	if (cmd->execute_cmd)
1711 		error = cmd->execute_cmd(cmd);
1712 
1713 	if (error) {
1714 		spin_lock_irq(&cmd->t_state_lock);
1715 		cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1716 		spin_unlock_irq(&cmd->t_state_lock);
1717 
1718 		transport_generic_request_failure(cmd);
1719 	}
1720 }
1721 
1722 void target_execute_cmd(struct se_cmd *cmd)
1723 {
1724 	struct se_device *dev = cmd->se_dev;
1725 
1726 	/*
1727 	 * If the received CDB has aleady been aborted stop processing it here.
1728 	 */
1729 	if (transport_check_aborted_status(cmd, 1))
1730 		return;
1731 
1732 	/*
1733 	 * Determine if IOCTL context caller in requesting the stopping of this
1734 	 * command for LUN shutdown purposes.
1735 	 */
1736 	spin_lock_irq(&cmd->t_state_lock);
1737 	if (cmd->transport_state & CMD_T_LUN_STOP) {
1738 		pr_debug("%s:%d CMD_T_LUN_STOP for ITT: 0x%08x\n",
1739 			__func__, __LINE__, cmd->se_tfo->get_task_tag(cmd));
1740 
1741 		cmd->transport_state &= ~CMD_T_ACTIVE;
1742 		spin_unlock_irq(&cmd->t_state_lock);
1743 		complete(&cmd->transport_lun_stop_comp);
1744 		return;
1745 	}
1746 	/*
1747 	 * Determine if frontend context caller is requesting the stopping of
1748 	 * this command for frontend exceptions.
1749 	 */
1750 	if (cmd->transport_state & CMD_T_STOP) {
1751 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
1752 			__func__, __LINE__,
1753 			cmd->se_tfo->get_task_tag(cmd));
1754 
1755 		spin_unlock_irq(&cmd->t_state_lock);
1756 		complete(&cmd->t_transport_stop_comp);
1757 		return;
1758 	}
1759 
1760 	cmd->t_state = TRANSPORT_PROCESSING;
1761 	spin_unlock_irq(&cmd->t_state_lock);
1762 
1763 	if (dev->dev_task_attr_type != SAM_TASK_ATTR_EMULATED)
1764 		goto execute;
1765 
1766 	/*
1767 	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1768 	 * to allow the passed struct se_cmd list of tasks to the front of the list.
1769 	 */
1770 	switch (cmd->sam_task_attr) {
1771 	case MSG_HEAD_TAG:
1772 		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
1773 			 "se_ordered_id: %u\n",
1774 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1775 		goto execute;
1776 	case MSG_ORDERED_TAG:
1777 		atomic_inc(&dev->dev_ordered_sync);
1778 		smp_mb__after_atomic_inc();
1779 
1780 		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
1781 			 " se_ordered_id: %u\n",
1782 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1783 
1784 		/*
1785 		 * Execute an ORDERED command if no other older commands
1786 		 * exist that need to be completed first.
1787 		 */
1788 		if (!atomic_read(&dev->simple_cmds))
1789 			goto execute;
1790 		break;
1791 	default:
1792 		/*
1793 		 * For SIMPLE and UNTAGGED Task Attribute commands
1794 		 */
1795 		atomic_inc(&dev->simple_cmds);
1796 		smp_mb__after_atomic_inc();
1797 		break;
1798 	}
1799 
1800 	if (atomic_read(&dev->dev_ordered_sync) != 0) {
1801 		spin_lock(&dev->delayed_cmd_lock);
1802 		list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1803 		spin_unlock(&dev->delayed_cmd_lock);
1804 
1805 		pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
1806 			" delayed CMD list, se_ordered_id: %u\n",
1807 			cmd->t_task_cdb[0], cmd->sam_task_attr,
1808 			cmd->se_ordered_id);
1809 		return;
1810 	}
1811 
1812 execute:
1813 	/*
1814 	 * Otherwise, no ORDERED task attributes exist..
1815 	 */
1816 	__target_execute_cmd(cmd);
1817 }
1818 EXPORT_SYMBOL(target_execute_cmd);
1819 
1820 /*
1821  * Used to obtain Sense Data from underlying Linux/SCSI struct scsi_cmnd
1822  */
1823 static int transport_get_sense_data(struct se_cmd *cmd)
1824 {
1825 	unsigned char *buffer = cmd->sense_buffer, *sense_buffer = NULL;
1826 	struct se_device *dev = cmd->se_dev;
1827 	unsigned long flags;
1828 	u32 offset = 0;
1829 
1830 	WARN_ON(!cmd->se_lun);
1831 
1832 	if (!dev)
1833 		return 0;
1834 
1835 	spin_lock_irqsave(&cmd->t_state_lock, flags);
1836 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
1837 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1838 		return 0;
1839 	}
1840 
1841 	if (!(cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE))
1842 		goto out;
1843 
1844 	if (!dev->transport->get_sense_buffer) {
1845 		pr_err("dev->transport->get_sense_buffer is NULL\n");
1846 		goto out;
1847 	}
1848 
1849 	sense_buffer = dev->transport->get_sense_buffer(cmd);
1850 	if (!sense_buffer) {
1851 		pr_err("ITT 0x%08x cmd %p: Unable to locate"
1852 			" sense buffer for task with sense\n",
1853 			cmd->se_tfo->get_task_tag(cmd), cmd);
1854 		goto out;
1855 	}
1856 
1857 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1858 
1859 	offset = cmd->se_tfo->set_fabric_sense_len(cmd, TRANSPORT_SENSE_BUFFER);
1860 
1861 	memcpy(&buffer[offset], sense_buffer, TRANSPORT_SENSE_BUFFER);
1862 
1863 	/* Automatically padded */
1864 	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER + offset;
1865 
1866 	pr_debug("HBA_[%u]_PLUG[%s]: Set SAM STATUS: 0x%02x and sense\n",
1867 		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
1868 	return 0;
1869 
1870 out:
1871 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1872 	return -1;
1873 }
1874 
1875 /*
1876  * Process all commands up to the last received ORDERED task attribute which
1877  * requires another blocking boundary
1878  */
1879 static void target_restart_delayed_cmds(struct se_device *dev)
1880 {
1881 	for (;;) {
1882 		struct se_cmd *cmd;
1883 
1884 		spin_lock(&dev->delayed_cmd_lock);
1885 		if (list_empty(&dev->delayed_cmd_list)) {
1886 			spin_unlock(&dev->delayed_cmd_lock);
1887 			break;
1888 		}
1889 
1890 		cmd = list_entry(dev->delayed_cmd_list.next,
1891 				 struct se_cmd, se_delayed_node);
1892 		list_del(&cmd->se_delayed_node);
1893 		spin_unlock(&dev->delayed_cmd_lock);
1894 
1895 		__target_execute_cmd(cmd);
1896 
1897 		if (cmd->sam_task_attr == MSG_ORDERED_TAG)
1898 			break;
1899 	}
1900 }
1901 
1902 /*
1903  * Called from I/O completion to determine which dormant/delayed
1904  * and ordered cmds need to have their tasks added to the execution queue.
1905  */
1906 static void transport_complete_task_attr(struct se_cmd *cmd)
1907 {
1908 	struct se_device *dev = cmd->se_dev;
1909 
1910 	if (cmd->sam_task_attr == MSG_SIMPLE_TAG) {
1911 		atomic_dec(&dev->simple_cmds);
1912 		smp_mb__after_atomic_dec();
1913 		dev->dev_cur_ordered_id++;
1914 		pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
1915 			" SIMPLE: %u\n", dev->dev_cur_ordered_id,
1916 			cmd->se_ordered_id);
1917 	} else if (cmd->sam_task_attr == MSG_HEAD_TAG) {
1918 		dev->dev_cur_ordered_id++;
1919 		pr_debug("Incremented dev_cur_ordered_id: %u for"
1920 			" HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
1921 			cmd->se_ordered_id);
1922 	} else if (cmd->sam_task_attr == MSG_ORDERED_TAG) {
1923 		atomic_dec(&dev->dev_ordered_sync);
1924 		smp_mb__after_atomic_dec();
1925 
1926 		dev->dev_cur_ordered_id++;
1927 		pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
1928 			" %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
1929 	}
1930 
1931 	target_restart_delayed_cmds(dev);
1932 }
1933 
1934 static void transport_complete_qf(struct se_cmd *cmd)
1935 {
1936 	int ret = 0;
1937 
1938 	if (cmd->se_dev->dev_task_attr_type == SAM_TASK_ATTR_EMULATED)
1939 		transport_complete_task_attr(cmd);
1940 
1941 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1942 		ret = cmd->se_tfo->queue_status(cmd);
1943 		if (ret)
1944 			goto out;
1945 	}
1946 
1947 	switch (cmd->data_direction) {
1948 	case DMA_FROM_DEVICE:
1949 		ret = cmd->se_tfo->queue_data_in(cmd);
1950 		break;
1951 	case DMA_TO_DEVICE:
1952 		if (cmd->t_bidi_data_sg) {
1953 			ret = cmd->se_tfo->queue_data_in(cmd);
1954 			if (ret < 0)
1955 				break;
1956 		}
1957 		/* Fall through for DMA_TO_DEVICE */
1958 	case DMA_NONE:
1959 		ret = cmd->se_tfo->queue_status(cmd);
1960 		break;
1961 	default:
1962 		break;
1963 	}
1964 
1965 out:
1966 	if (ret < 0) {
1967 		transport_handle_queue_full(cmd, cmd->se_dev);
1968 		return;
1969 	}
1970 	transport_lun_remove_cmd(cmd);
1971 	transport_cmd_check_stop_to_fabric(cmd);
1972 }
1973 
1974 static void transport_handle_queue_full(
1975 	struct se_cmd *cmd,
1976 	struct se_device *dev)
1977 {
1978 	spin_lock_irq(&dev->qf_cmd_lock);
1979 	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
1980 	atomic_inc(&dev->dev_qf_count);
1981 	smp_mb__after_atomic_inc();
1982 	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
1983 
1984 	schedule_work(&cmd->se_dev->qf_work_queue);
1985 }
1986 
1987 static void target_complete_ok_work(struct work_struct *work)
1988 {
1989 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
1990 	int reason = 0, ret;
1991 
1992 	/*
1993 	 * Check if we need to move delayed/dormant tasks from cmds on the
1994 	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
1995 	 * Attribute.
1996 	 */
1997 	if (cmd->se_dev->dev_task_attr_type == SAM_TASK_ATTR_EMULATED)
1998 		transport_complete_task_attr(cmd);
1999 	/*
2000 	 * Check to schedule QUEUE_FULL work, or execute an existing
2001 	 * cmd->transport_qf_callback()
2002 	 */
2003 	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2004 		schedule_work(&cmd->se_dev->qf_work_queue);
2005 
2006 	/*
2007 	 * Check if we need to retrieve a sense buffer from
2008 	 * the struct se_cmd in question.
2009 	 */
2010 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2011 		if (transport_get_sense_data(cmd) < 0)
2012 			reason = TCM_NON_EXISTENT_LUN;
2013 
2014 		if (cmd->scsi_status) {
2015 			ret = transport_send_check_condition_and_sense(
2016 					cmd, reason, 1);
2017 			if (ret == -EAGAIN || ret == -ENOMEM)
2018 				goto queue_full;
2019 
2020 			transport_lun_remove_cmd(cmd);
2021 			transport_cmd_check_stop_to_fabric(cmd);
2022 			return;
2023 		}
2024 	}
2025 	/*
2026 	 * Check for a callback, used by amongst other things
2027 	 * XDWRITE_READ_10 emulation.
2028 	 */
2029 	if (cmd->transport_complete_callback)
2030 		cmd->transport_complete_callback(cmd);
2031 
2032 	switch (cmd->data_direction) {
2033 	case DMA_FROM_DEVICE:
2034 		spin_lock(&cmd->se_lun->lun_sep_lock);
2035 		if (cmd->se_lun->lun_sep) {
2036 			cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
2037 					cmd->data_length;
2038 		}
2039 		spin_unlock(&cmd->se_lun->lun_sep_lock);
2040 
2041 		ret = cmd->se_tfo->queue_data_in(cmd);
2042 		if (ret == -EAGAIN || ret == -ENOMEM)
2043 			goto queue_full;
2044 		break;
2045 	case DMA_TO_DEVICE:
2046 		spin_lock(&cmd->se_lun->lun_sep_lock);
2047 		if (cmd->se_lun->lun_sep) {
2048 			cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
2049 				cmd->data_length;
2050 		}
2051 		spin_unlock(&cmd->se_lun->lun_sep_lock);
2052 		/*
2053 		 * Check if we need to send READ payload for BIDI-COMMAND
2054 		 */
2055 		if (cmd->t_bidi_data_sg) {
2056 			spin_lock(&cmd->se_lun->lun_sep_lock);
2057 			if (cmd->se_lun->lun_sep) {
2058 				cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
2059 					cmd->data_length;
2060 			}
2061 			spin_unlock(&cmd->se_lun->lun_sep_lock);
2062 			ret = cmd->se_tfo->queue_data_in(cmd);
2063 			if (ret == -EAGAIN || ret == -ENOMEM)
2064 				goto queue_full;
2065 			break;
2066 		}
2067 		/* Fall through for DMA_TO_DEVICE */
2068 	case DMA_NONE:
2069 		ret = cmd->se_tfo->queue_status(cmd);
2070 		if (ret == -EAGAIN || ret == -ENOMEM)
2071 			goto queue_full;
2072 		break;
2073 	default:
2074 		break;
2075 	}
2076 
2077 	transport_lun_remove_cmd(cmd);
2078 	transport_cmd_check_stop_to_fabric(cmd);
2079 	return;
2080 
2081 queue_full:
2082 	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2083 		" data_direction: %d\n", cmd, cmd->data_direction);
2084 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2085 	transport_handle_queue_full(cmd, cmd->se_dev);
2086 }
2087 
2088 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
2089 {
2090 	struct scatterlist *sg;
2091 	int count;
2092 
2093 	for_each_sg(sgl, sg, nents, count)
2094 		__free_page(sg_page(sg));
2095 
2096 	kfree(sgl);
2097 }
2098 
2099 static inline void transport_free_pages(struct se_cmd *cmd)
2100 {
2101 	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC)
2102 		return;
2103 
2104 	transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2105 	cmd->t_data_sg = NULL;
2106 	cmd->t_data_nents = 0;
2107 
2108 	transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2109 	cmd->t_bidi_data_sg = NULL;
2110 	cmd->t_bidi_data_nents = 0;
2111 }
2112 
2113 /**
2114  * transport_release_cmd - free a command
2115  * @cmd:       command to free
2116  *
2117  * This routine unconditionally frees a command, and reference counting
2118  * or list removal must be done in the caller.
2119  */
2120 static void transport_release_cmd(struct se_cmd *cmd)
2121 {
2122 	BUG_ON(!cmd->se_tfo);
2123 
2124 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2125 		core_tmr_release_req(cmd->se_tmr_req);
2126 	if (cmd->t_task_cdb != cmd->__t_task_cdb)
2127 		kfree(cmd->t_task_cdb);
2128 	/*
2129 	 * If this cmd has been setup with target_get_sess_cmd(), drop
2130 	 * the kref and call ->release_cmd() in kref callback.
2131 	 */
2132 	 if (cmd->check_release != 0) {
2133 		target_put_sess_cmd(cmd->se_sess, cmd);
2134 		return;
2135 	}
2136 	cmd->se_tfo->release_cmd(cmd);
2137 }
2138 
2139 /**
2140  * transport_put_cmd - release a reference to a command
2141  * @cmd:       command to release
2142  *
2143  * This routine releases our reference to the command and frees it if possible.
2144  */
2145 static void transport_put_cmd(struct se_cmd *cmd)
2146 {
2147 	unsigned long flags;
2148 
2149 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2150 	if (atomic_read(&cmd->t_fe_count)) {
2151 		if (!atomic_dec_and_test(&cmd->t_fe_count))
2152 			goto out_busy;
2153 	}
2154 
2155 	if (cmd->transport_state & CMD_T_DEV_ACTIVE) {
2156 		cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
2157 		target_remove_from_state_list(cmd);
2158 	}
2159 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2160 
2161 	transport_free_pages(cmd);
2162 	transport_release_cmd(cmd);
2163 	return;
2164 out_busy:
2165 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2166 }
2167 
2168 /*
2169  * transport_generic_map_mem_to_cmd - Use fabric-alloced pages instead of
2170  * allocating in the core.
2171  * @cmd:  Associated se_cmd descriptor
2172  * @mem:  SGL style memory for TCM WRITE / READ
2173  * @sg_mem_num: Number of SGL elements
2174  * @mem_bidi_in: SGL style memory for TCM BIDI READ
2175  * @sg_mem_bidi_num: Number of BIDI READ SGL elements
2176  *
2177  * Return: nonzero return cmd was rejected for -ENOMEM or inproper usage
2178  * of parameters.
2179  */
2180 int transport_generic_map_mem_to_cmd(
2181 	struct se_cmd *cmd,
2182 	struct scatterlist *sgl,
2183 	u32 sgl_count,
2184 	struct scatterlist *sgl_bidi,
2185 	u32 sgl_bidi_count)
2186 {
2187 	if (!sgl || !sgl_count)
2188 		return 0;
2189 
2190 	/*
2191 	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
2192 	 * scatterlists already have been set to follow what the fabric
2193 	 * passes for the original expected data transfer length.
2194 	 */
2195 	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
2196 		pr_warn("Rejecting SCSI DATA overflow for fabric using"
2197 			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
2198 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
2199 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
2200 		return -EINVAL;
2201 	}
2202 
2203 	cmd->t_data_sg = sgl;
2204 	cmd->t_data_nents = sgl_count;
2205 
2206 	if (sgl_bidi && sgl_bidi_count) {
2207 		cmd->t_bidi_data_sg = sgl_bidi;
2208 		cmd->t_bidi_data_nents = sgl_bidi_count;
2209 	}
2210 	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
2211 	return 0;
2212 }
2213 EXPORT_SYMBOL(transport_generic_map_mem_to_cmd);
2214 
2215 void *transport_kmap_data_sg(struct se_cmd *cmd)
2216 {
2217 	struct scatterlist *sg = cmd->t_data_sg;
2218 	struct page **pages;
2219 	int i;
2220 
2221 	BUG_ON(!sg);
2222 	/*
2223 	 * We need to take into account a possible offset here for fabrics like
2224 	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2225 	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2226 	 */
2227 	if (!cmd->t_data_nents)
2228 		return NULL;
2229 	else if (cmd->t_data_nents == 1)
2230 		return kmap(sg_page(sg)) + sg->offset;
2231 
2232 	/* >1 page. use vmap */
2233 	pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2234 	if (!pages)
2235 		return NULL;
2236 
2237 	/* convert sg[] to pages[] */
2238 	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2239 		pages[i] = sg_page(sg);
2240 	}
2241 
2242 	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2243 	kfree(pages);
2244 	if (!cmd->t_data_vmap)
2245 		return NULL;
2246 
2247 	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2248 }
2249 EXPORT_SYMBOL(transport_kmap_data_sg);
2250 
2251 void transport_kunmap_data_sg(struct se_cmd *cmd)
2252 {
2253 	if (!cmd->t_data_nents) {
2254 		return;
2255 	} else if (cmd->t_data_nents == 1) {
2256 		kunmap(sg_page(cmd->t_data_sg));
2257 		return;
2258 	}
2259 
2260 	vunmap(cmd->t_data_vmap);
2261 	cmd->t_data_vmap = NULL;
2262 }
2263 EXPORT_SYMBOL(transport_kunmap_data_sg);
2264 
2265 static int
2266 transport_generic_get_mem(struct se_cmd *cmd)
2267 {
2268 	u32 length = cmd->data_length;
2269 	unsigned int nents;
2270 	struct page *page;
2271 	gfp_t zero_flag;
2272 	int i = 0;
2273 
2274 	nents = DIV_ROUND_UP(length, PAGE_SIZE);
2275 	cmd->t_data_sg = kmalloc(sizeof(struct scatterlist) * nents, GFP_KERNEL);
2276 	if (!cmd->t_data_sg)
2277 		return -ENOMEM;
2278 
2279 	cmd->t_data_nents = nents;
2280 	sg_init_table(cmd->t_data_sg, nents);
2281 
2282 	zero_flag = cmd->se_cmd_flags & SCF_SCSI_DATA_CDB ? 0 : __GFP_ZERO;
2283 
2284 	while (length) {
2285 		u32 page_len = min_t(u32, length, PAGE_SIZE);
2286 		page = alloc_page(GFP_KERNEL | zero_flag);
2287 		if (!page)
2288 			goto out;
2289 
2290 		sg_set_page(&cmd->t_data_sg[i], page, page_len, 0);
2291 		length -= page_len;
2292 		i++;
2293 	}
2294 	return 0;
2295 
2296 out:
2297 	while (i >= 0) {
2298 		__free_page(sg_page(&cmd->t_data_sg[i]));
2299 		i--;
2300 	}
2301 	kfree(cmd->t_data_sg);
2302 	cmd->t_data_sg = NULL;
2303 	return -ENOMEM;
2304 }
2305 
2306 /*
2307  * Allocate any required resources to execute the command.  For writes we
2308  * might not have the payload yet, so notify the fabric via a call to
2309  * ->write_pending instead. Otherwise place it on the execution queue.
2310  */
2311 int transport_generic_new_cmd(struct se_cmd *cmd)
2312 {
2313 	int ret = 0;
2314 
2315 	/*
2316 	 * Determine is the TCM fabric module has already allocated physical
2317 	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2318 	 * beforehand.
2319 	 */
2320 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2321 	    cmd->data_length) {
2322 		ret = transport_generic_get_mem(cmd);
2323 		if (ret < 0)
2324 			goto out_fail;
2325 	}
2326 
2327 	/* Workaround for handling zero-length control CDBs */
2328 	if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) && !cmd->data_length) {
2329 		spin_lock_irq(&cmd->t_state_lock);
2330 		cmd->t_state = TRANSPORT_COMPLETE;
2331 		cmd->transport_state |= CMD_T_ACTIVE;
2332 		spin_unlock_irq(&cmd->t_state_lock);
2333 
2334 		if (cmd->t_task_cdb[0] == REQUEST_SENSE) {
2335 			u8 ua_asc = 0, ua_ascq = 0;
2336 
2337 			core_scsi3_ua_clear_for_request_sense(cmd,
2338 					&ua_asc, &ua_ascq);
2339 		}
2340 
2341 		INIT_WORK(&cmd->work, target_complete_ok_work);
2342 		queue_work(target_completion_wq, &cmd->work);
2343 		return 0;
2344 	}
2345 
2346 	atomic_inc(&cmd->t_fe_count);
2347 
2348 	/*
2349 	 * If this command is not a write we can execute it right here,
2350 	 * for write buffers we need to notify the fabric driver first
2351 	 * and let it call back once the write buffers are ready.
2352 	 */
2353 	target_add_to_state_list(cmd);
2354 	if (cmd->data_direction != DMA_TO_DEVICE) {
2355 		target_execute_cmd(cmd);
2356 		return 0;
2357 	}
2358 
2359 	spin_lock_irq(&cmd->t_state_lock);
2360 	cmd->t_state = TRANSPORT_WRITE_PENDING;
2361 	spin_unlock_irq(&cmd->t_state_lock);
2362 
2363 	transport_cmd_check_stop(cmd, false);
2364 
2365 	ret = cmd->se_tfo->write_pending(cmd);
2366 	if (ret == -EAGAIN || ret == -ENOMEM)
2367 		goto queue_full;
2368 
2369 	if (ret < 0)
2370 		return ret;
2371 	return 1;
2372 
2373 out_fail:
2374 	cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
2375 	cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2376 	return -EINVAL;
2377 queue_full:
2378 	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2379 	cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2380 	transport_handle_queue_full(cmd, cmd->se_dev);
2381 	return 0;
2382 }
2383 EXPORT_SYMBOL(transport_generic_new_cmd);
2384 
2385 static void transport_write_pending_qf(struct se_cmd *cmd)
2386 {
2387 	int ret;
2388 
2389 	ret = cmd->se_tfo->write_pending(cmd);
2390 	if (ret == -EAGAIN || ret == -ENOMEM) {
2391 		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2392 			 cmd);
2393 		transport_handle_queue_full(cmd, cmd->se_dev);
2394 	}
2395 }
2396 
2397 void transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2398 {
2399 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2400 		if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2401 			 transport_wait_for_tasks(cmd);
2402 
2403 		transport_release_cmd(cmd);
2404 	} else {
2405 		if (wait_for_tasks)
2406 			transport_wait_for_tasks(cmd);
2407 
2408 		core_dec_lacl_count(cmd->se_sess->se_node_acl, cmd);
2409 
2410 		if (cmd->se_lun)
2411 			transport_lun_remove_cmd(cmd);
2412 
2413 		transport_put_cmd(cmd);
2414 	}
2415 }
2416 EXPORT_SYMBOL(transport_generic_free_cmd);
2417 
2418 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2419  * @se_sess:	session to reference
2420  * @se_cmd:	command descriptor to add
2421  * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
2422  */
2423 static int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
2424 			       bool ack_kref)
2425 {
2426 	unsigned long flags;
2427 	int ret = 0;
2428 
2429 	kref_init(&se_cmd->cmd_kref);
2430 	/*
2431 	 * Add a second kref if the fabric caller is expecting to handle
2432 	 * fabric acknowledgement that requires two target_put_sess_cmd()
2433 	 * invocations before se_cmd descriptor release.
2434 	 */
2435 	if (ack_kref == true) {
2436 		kref_get(&se_cmd->cmd_kref);
2437 		se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2438 	}
2439 
2440 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2441 	if (se_sess->sess_tearing_down) {
2442 		ret = -ESHUTDOWN;
2443 		goto out;
2444 	}
2445 	list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2446 	se_cmd->check_release = 1;
2447 
2448 out:
2449 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2450 	return ret;
2451 }
2452 
2453 static void target_release_cmd_kref(struct kref *kref)
2454 {
2455 	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2456 	struct se_session *se_sess = se_cmd->se_sess;
2457 	unsigned long flags;
2458 
2459 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2460 	if (list_empty(&se_cmd->se_cmd_list)) {
2461 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2462 		se_cmd->se_tfo->release_cmd(se_cmd);
2463 		return;
2464 	}
2465 	if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2466 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2467 		complete(&se_cmd->cmd_wait_comp);
2468 		return;
2469 	}
2470 	list_del(&se_cmd->se_cmd_list);
2471 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2472 
2473 	se_cmd->se_tfo->release_cmd(se_cmd);
2474 }
2475 
2476 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2477  * @se_sess:	session to reference
2478  * @se_cmd:	command descriptor to drop
2479  */
2480 int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd)
2481 {
2482 	return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2483 }
2484 EXPORT_SYMBOL(target_put_sess_cmd);
2485 
2486 /* target_sess_cmd_list_set_waiting - Flag all commands in
2487  *         sess_cmd_list to complete cmd_wait_comp.  Set
2488  *         sess_tearing_down so no more commands are queued.
2489  * @se_sess:	session to flag
2490  */
2491 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2492 {
2493 	struct se_cmd *se_cmd;
2494 	unsigned long flags;
2495 
2496 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2497 
2498 	WARN_ON(se_sess->sess_tearing_down);
2499 	se_sess->sess_tearing_down = 1;
2500 
2501 	list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list)
2502 		se_cmd->cmd_wait_set = 1;
2503 
2504 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2505 }
2506 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2507 
2508 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2509  * @se_sess:    session to wait for active I/O
2510  * @wait_for_tasks:	Make extra transport_wait_for_tasks call
2511  */
2512 void target_wait_for_sess_cmds(
2513 	struct se_session *se_sess,
2514 	int wait_for_tasks)
2515 {
2516 	struct se_cmd *se_cmd, *tmp_cmd;
2517 	bool rc = false;
2518 
2519 	list_for_each_entry_safe(se_cmd, tmp_cmd,
2520 				&se_sess->sess_cmd_list, se_cmd_list) {
2521 		list_del(&se_cmd->se_cmd_list);
2522 
2523 		pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2524 			" %d\n", se_cmd, se_cmd->t_state,
2525 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2526 
2527 		if (wait_for_tasks) {
2528 			pr_debug("Calling transport_wait_for_tasks se_cmd: %p t_state: %d,"
2529 				" fabric state: %d\n", se_cmd, se_cmd->t_state,
2530 				se_cmd->se_tfo->get_cmd_state(se_cmd));
2531 
2532 			rc = transport_wait_for_tasks(se_cmd);
2533 
2534 			pr_debug("After transport_wait_for_tasks se_cmd: %p t_state: %d,"
2535 				" fabric state: %d\n", se_cmd, se_cmd->t_state,
2536 				se_cmd->se_tfo->get_cmd_state(se_cmd));
2537 		}
2538 
2539 		if (!rc) {
2540 			wait_for_completion(&se_cmd->cmd_wait_comp);
2541 			pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2542 				" fabric state: %d\n", se_cmd, se_cmd->t_state,
2543 				se_cmd->se_tfo->get_cmd_state(se_cmd));
2544 		}
2545 
2546 		se_cmd->se_tfo->release_cmd(se_cmd);
2547 	}
2548 }
2549 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2550 
2551 /*	transport_lun_wait_for_tasks():
2552  *
2553  *	Called from ConfigFS context to stop the passed struct se_cmd to allow
2554  *	an struct se_lun to be successfully shutdown.
2555  */
2556 static int transport_lun_wait_for_tasks(struct se_cmd *cmd, struct se_lun *lun)
2557 {
2558 	unsigned long flags;
2559 	int ret = 0;
2560 
2561 	/*
2562 	 * If the frontend has already requested this struct se_cmd to
2563 	 * be stopped, we can safely ignore this struct se_cmd.
2564 	 */
2565 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2566 	if (cmd->transport_state & CMD_T_STOP) {
2567 		cmd->transport_state &= ~CMD_T_LUN_STOP;
2568 
2569 		pr_debug("ConfigFS ITT[0x%08x] - CMD_T_STOP, skipping\n",
2570 			 cmd->se_tfo->get_task_tag(cmd));
2571 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2572 		transport_cmd_check_stop(cmd, false);
2573 		return -EPERM;
2574 	}
2575 	cmd->transport_state |= CMD_T_LUN_FE_STOP;
2576 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2577 
2578 	// XXX: audit task_flags checks.
2579 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2580 	if ((cmd->transport_state & CMD_T_BUSY) &&
2581 	    (cmd->transport_state & CMD_T_SENT)) {
2582 		if (!target_stop_cmd(cmd, &flags))
2583 			ret++;
2584 	}
2585 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2586 
2587 	pr_debug("ConfigFS: cmd: %p stop tasks ret:"
2588 			" %d\n", cmd, ret);
2589 	if (!ret) {
2590 		pr_debug("ConfigFS: ITT[0x%08x] - stopping cmd....\n",
2591 				cmd->se_tfo->get_task_tag(cmd));
2592 		wait_for_completion(&cmd->transport_lun_stop_comp);
2593 		pr_debug("ConfigFS: ITT[0x%08x] - stopped cmd....\n",
2594 				cmd->se_tfo->get_task_tag(cmd));
2595 	}
2596 
2597 	return 0;
2598 }
2599 
2600 static void __transport_clear_lun_from_sessions(struct se_lun *lun)
2601 {
2602 	struct se_cmd *cmd = NULL;
2603 	unsigned long lun_flags, cmd_flags;
2604 	/*
2605 	 * Do exception processing and return CHECK_CONDITION status to the
2606 	 * Initiator Port.
2607 	 */
2608 	spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2609 	while (!list_empty(&lun->lun_cmd_list)) {
2610 		cmd = list_first_entry(&lun->lun_cmd_list,
2611 		       struct se_cmd, se_lun_node);
2612 		list_del_init(&cmd->se_lun_node);
2613 
2614 		spin_lock(&cmd->t_state_lock);
2615 		pr_debug("SE_LUN[%d] - Setting cmd->transport"
2616 			"_lun_stop for  ITT: 0x%08x\n",
2617 			cmd->se_lun->unpacked_lun,
2618 			cmd->se_tfo->get_task_tag(cmd));
2619 		cmd->transport_state |= CMD_T_LUN_STOP;
2620 		spin_unlock(&cmd->t_state_lock);
2621 
2622 		spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
2623 
2624 		if (!cmd->se_lun) {
2625 			pr_err("ITT: 0x%08x, [i,t]_state: %u/%u\n",
2626 				cmd->se_tfo->get_task_tag(cmd),
2627 				cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2628 			BUG();
2629 		}
2630 		/*
2631 		 * If the Storage engine still owns the iscsi_cmd_t, determine
2632 		 * and/or stop its context.
2633 		 */
2634 		pr_debug("SE_LUN[%d] - ITT: 0x%08x before transport"
2635 			"_lun_wait_for_tasks()\n", cmd->se_lun->unpacked_lun,
2636 			cmd->se_tfo->get_task_tag(cmd));
2637 
2638 		if (transport_lun_wait_for_tasks(cmd, cmd->se_lun) < 0) {
2639 			spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2640 			continue;
2641 		}
2642 
2643 		pr_debug("SE_LUN[%d] - ITT: 0x%08x after transport_lun"
2644 			"_wait_for_tasks(): SUCCESS\n",
2645 			cmd->se_lun->unpacked_lun,
2646 			cmd->se_tfo->get_task_tag(cmd));
2647 
2648 		spin_lock_irqsave(&cmd->t_state_lock, cmd_flags);
2649 		if (!(cmd->transport_state & CMD_T_DEV_ACTIVE)) {
2650 			spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2651 			goto check_cond;
2652 		}
2653 		cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
2654 		target_remove_from_state_list(cmd);
2655 		spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2656 
2657 		/*
2658 		 * The Storage engine stopped this struct se_cmd before it was
2659 		 * send to the fabric frontend for delivery back to the
2660 		 * Initiator Node.  Return this SCSI CDB back with an
2661 		 * CHECK_CONDITION status.
2662 		 */
2663 check_cond:
2664 		transport_send_check_condition_and_sense(cmd,
2665 				TCM_NON_EXISTENT_LUN, 0);
2666 		/*
2667 		 *  If the fabric frontend is waiting for this iscsi_cmd_t to
2668 		 * be released, notify the waiting thread now that LU has
2669 		 * finished accessing it.
2670 		 */
2671 		spin_lock_irqsave(&cmd->t_state_lock, cmd_flags);
2672 		if (cmd->transport_state & CMD_T_LUN_FE_STOP) {
2673 			pr_debug("SE_LUN[%d] - Detected FE stop for"
2674 				" struct se_cmd: %p ITT: 0x%08x\n",
2675 				lun->unpacked_lun,
2676 				cmd, cmd->se_tfo->get_task_tag(cmd));
2677 
2678 			spin_unlock_irqrestore(&cmd->t_state_lock,
2679 					cmd_flags);
2680 			transport_cmd_check_stop(cmd, false);
2681 			complete(&cmd->transport_lun_fe_stop_comp);
2682 			spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2683 			continue;
2684 		}
2685 		pr_debug("SE_LUN[%d] - ITT: 0x%08x finished processing\n",
2686 			lun->unpacked_lun, cmd->se_tfo->get_task_tag(cmd));
2687 
2688 		spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2689 		spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2690 	}
2691 	spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
2692 }
2693 
2694 static int transport_clear_lun_thread(void *p)
2695 {
2696 	struct se_lun *lun = p;
2697 
2698 	__transport_clear_lun_from_sessions(lun);
2699 	complete(&lun->lun_shutdown_comp);
2700 
2701 	return 0;
2702 }
2703 
2704 int transport_clear_lun_from_sessions(struct se_lun *lun)
2705 {
2706 	struct task_struct *kt;
2707 
2708 	kt = kthread_run(transport_clear_lun_thread, lun,
2709 			"tcm_cl_%u", lun->unpacked_lun);
2710 	if (IS_ERR(kt)) {
2711 		pr_err("Unable to start clear_lun thread\n");
2712 		return PTR_ERR(kt);
2713 	}
2714 	wait_for_completion(&lun->lun_shutdown_comp);
2715 
2716 	return 0;
2717 }
2718 
2719 /**
2720  * transport_wait_for_tasks - wait for completion to occur
2721  * @cmd:	command to wait
2722  *
2723  * Called from frontend fabric context to wait for storage engine
2724  * to pause and/or release frontend generated struct se_cmd.
2725  */
2726 bool transport_wait_for_tasks(struct se_cmd *cmd)
2727 {
2728 	unsigned long flags;
2729 
2730 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2731 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2732 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2733 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2734 		return false;
2735 	}
2736 
2737 	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2738 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2739 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2740 		return false;
2741 	}
2742 	/*
2743 	 * If we are already stopped due to an external event (ie: LUN shutdown)
2744 	 * sleep until the connection can have the passed struct se_cmd back.
2745 	 * The cmd->transport_lun_stopped_sem will be upped by
2746 	 * transport_clear_lun_from_sessions() once the ConfigFS context caller
2747 	 * has completed its operation on the struct se_cmd.
2748 	 */
2749 	if (cmd->transport_state & CMD_T_LUN_STOP) {
2750 		pr_debug("wait_for_tasks: Stopping"
2751 			" wait_for_completion(&cmd->t_tasktransport_lun_fe"
2752 			"_stop_comp); for ITT: 0x%08x\n",
2753 			cmd->se_tfo->get_task_tag(cmd));
2754 		/*
2755 		 * There is a special case for WRITES where a FE exception +
2756 		 * LUN shutdown means ConfigFS context is still sleeping on
2757 		 * transport_lun_stop_comp in transport_lun_wait_for_tasks().
2758 		 * We go ahead and up transport_lun_stop_comp just to be sure
2759 		 * here.
2760 		 */
2761 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2762 		complete(&cmd->transport_lun_stop_comp);
2763 		wait_for_completion(&cmd->transport_lun_fe_stop_comp);
2764 		spin_lock_irqsave(&cmd->t_state_lock, flags);
2765 
2766 		target_remove_from_state_list(cmd);
2767 		/*
2768 		 * At this point, the frontend who was the originator of this
2769 		 * struct se_cmd, now owns the structure and can be released through
2770 		 * normal means below.
2771 		 */
2772 		pr_debug("wait_for_tasks: Stopped"
2773 			" wait_for_completion(&cmd->t_tasktransport_lun_fe_"
2774 			"stop_comp); for ITT: 0x%08x\n",
2775 			cmd->se_tfo->get_task_tag(cmd));
2776 
2777 		cmd->transport_state &= ~CMD_T_LUN_STOP;
2778 	}
2779 
2780 	if (!(cmd->transport_state & CMD_T_ACTIVE)) {
2781 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2782 		return false;
2783 	}
2784 
2785 	cmd->transport_state |= CMD_T_STOP;
2786 
2787 	pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
2788 		" i_state: %d, t_state: %d, CMD_T_STOP\n",
2789 		cmd, cmd->se_tfo->get_task_tag(cmd),
2790 		cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2791 
2792 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2793 
2794 	wait_for_completion(&cmd->t_transport_stop_comp);
2795 
2796 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2797 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2798 
2799 	pr_debug("wait_for_tasks: Stopped wait_for_compltion("
2800 		"&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
2801 		cmd->se_tfo->get_task_tag(cmd));
2802 
2803 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2804 
2805 	return true;
2806 }
2807 EXPORT_SYMBOL(transport_wait_for_tasks);
2808 
2809 static int transport_get_sense_codes(
2810 	struct se_cmd *cmd,
2811 	u8 *asc,
2812 	u8 *ascq)
2813 {
2814 	*asc = cmd->scsi_asc;
2815 	*ascq = cmd->scsi_ascq;
2816 
2817 	return 0;
2818 }
2819 
2820 static int transport_set_sense_codes(
2821 	struct se_cmd *cmd,
2822 	u8 asc,
2823 	u8 ascq)
2824 {
2825 	cmd->scsi_asc = asc;
2826 	cmd->scsi_ascq = ascq;
2827 
2828 	return 0;
2829 }
2830 
2831 int transport_send_check_condition_and_sense(
2832 	struct se_cmd *cmd,
2833 	u8 reason,
2834 	int from_transport)
2835 {
2836 	unsigned char *buffer = cmd->sense_buffer;
2837 	unsigned long flags;
2838 	int offset;
2839 	u8 asc = 0, ascq = 0;
2840 
2841 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2842 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2843 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2844 		return 0;
2845 	}
2846 	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2847 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2848 
2849 	if (!reason && from_transport)
2850 		goto after_reason;
2851 
2852 	if (!from_transport)
2853 		cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2854 	/*
2855 	 * Data Segment and SenseLength of the fabric response PDU.
2856 	 *
2857 	 * TRANSPORT_SENSE_BUFFER is now set to SCSI_SENSE_BUFFERSIZE
2858 	 * from include/scsi/scsi_cmnd.h
2859 	 */
2860 	offset = cmd->se_tfo->set_fabric_sense_len(cmd,
2861 				TRANSPORT_SENSE_BUFFER);
2862 	/*
2863 	 * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
2864 	 * SENSE KEY values from include/scsi/scsi.h
2865 	 */
2866 	switch (reason) {
2867 	case TCM_NON_EXISTENT_LUN:
2868 		/* CURRENT ERROR */
2869 		buffer[offset] = 0x70;
2870 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2871 		/* ILLEGAL REQUEST */
2872 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2873 		/* LOGICAL UNIT NOT SUPPORTED */
2874 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x25;
2875 		break;
2876 	case TCM_UNSUPPORTED_SCSI_OPCODE:
2877 	case TCM_SECTOR_COUNT_TOO_MANY:
2878 		/* CURRENT ERROR */
2879 		buffer[offset] = 0x70;
2880 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2881 		/* ILLEGAL REQUEST */
2882 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2883 		/* INVALID COMMAND OPERATION CODE */
2884 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x20;
2885 		break;
2886 	case TCM_UNKNOWN_MODE_PAGE:
2887 		/* CURRENT ERROR */
2888 		buffer[offset] = 0x70;
2889 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2890 		/* ILLEGAL REQUEST */
2891 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2892 		/* INVALID FIELD IN CDB */
2893 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x24;
2894 		break;
2895 	case TCM_CHECK_CONDITION_ABORT_CMD:
2896 		/* CURRENT ERROR */
2897 		buffer[offset] = 0x70;
2898 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2899 		/* ABORTED COMMAND */
2900 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2901 		/* BUS DEVICE RESET FUNCTION OCCURRED */
2902 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x29;
2903 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = 0x03;
2904 		break;
2905 	case TCM_INCORRECT_AMOUNT_OF_DATA:
2906 		/* CURRENT ERROR */
2907 		buffer[offset] = 0x70;
2908 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2909 		/* ABORTED COMMAND */
2910 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2911 		/* WRITE ERROR */
2912 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x0c;
2913 		/* NOT ENOUGH UNSOLICITED DATA */
2914 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = 0x0d;
2915 		break;
2916 	case TCM_INVALID_CDB_FIELD:
2917 		/* CURRENT ERROR */
2918 		buffer[offset] = 0x70;
2919 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2920 		/* ILLEGAL REQUEST */
2921 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2922 		/* INVALID FIELD IN CDB */
2923 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x24;
2924 		break;
2925 	case TCM_INVALID_PARAMETER_LIST:
2926 		/* CURRENT ERROR */
2927 		buffer[offset] = 0x70;
2928 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2929 		/* ILLEGAL REQUEST */
2930 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2931 		/* INVALID FIELD IN PARAMETER LIST */
2932 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x26;
2933 		break;
2934 	case TCM_UNEXPECTED_UNSOLICITED_DATA:
2935 		/* CURRENT ERROR */
2936 		buffer[offset] = 0x70;
2937 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2938 		/* ABORTED COMMAND */
2939 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2940 		/* WRITE ERROR */
2941 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x0c;
2942 		/* UNEXPECTED_UNSOLICITED_DATA */
2943 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = 0x0c;
2944 		break;
2945 	case TCM_SERVICE_CRC_ERROR:
2946 		/* CURRENT ERROR */
2947 		buffer[offset] = 0x70;
2948 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2949 		/* ABORTED COMMAND */
2950 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2951 		/* PROTOCOL SERVICE CRC ERROR */
2952 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x47;
2953 		/* N/A */
2954 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = 0x05;
2955 		break;
2956 	case TCM_SNACK_REJECTED:
2957 		/* CURRENT ERROR */
2958 		buffer[offset] = 0x70;
2959 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2960 		/* ABORTED COMMAND */
2961 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2962 		/* READ ERROR */
2963 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x11;
2964 		/* FAILED RETRANSMISSION REQUEST */
2965 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = 0x13;
2966 		break;
2967 	case TCM_WRITE_PROTECTED:
2968 		/* CURRENT ERROR */
2969 		buffer[offset] = 0x70;
2970 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2971 		/* DATA PROTECT */
2972 		buffer[offset+SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
2973 		/* WRITE PROTECTED */
2974 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x27;
2975 		break;
2976 	case TCM_ADDRESS_OUT_OF_RANGE:
2977 		/* CURRENT ERROR */
2978 		buffer[offset] = 0x70;
2979 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2980 		/* ILLEGAL REQUEST */
2981 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2982 		/* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2983 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x21;
2984 		break;
2985 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2986 		/* CURRENT ERROR */
2987 		buffer[offset] = 0x70;
2988 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2989 		/* UNIT ATTENTION */
2990 		buffer[offset+SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
2991 		core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2992 		buffer[offset+SPC_ASC_KEY_OFFSET] = asc;
2993 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = ascq;
2994 		break;
2995 	case TCM_CHECK_CONDITION_NOT_READY:
2996 		/* CURRENT ERROR */
2997 		buffer[offset] = 0x70;
2998 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2999 		/* Not Ready */
3000 		buffer[offset+SPC_SENSE_KEY_OFFSET] = NOT_READY;
3001 		transport_get_sense_codes(cmd, &asc, &ascq);
3002 		buffer[offset+SPC_ASC_KEY_OFFSET] = asc;
3003 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = ascq;
3004 		break;
3005 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
3006 	default:
3007 		/* CURRENT ERROR */
3008 		buffer[offset] = 0x70;
3009 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
3010 		/* ILLEGAL REQUEST */
3011 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
3012 		/* LOGICAL UNIT COMMUNICATION FAILURE */
3013 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x80;
3014 		break;
3015 	}
3016 	/*
3017 	 * This code uses linux/include/scsi/scsi.h SAM status codes!
3018 	 */
3019 	cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
3020 	/*
3021 	 * Automatically padded, this value is encoded in the fabric's
3022 	 * data_length response PDU containing the SCSI defined sense data.
3023 	 */
3024 	cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER + offset;
3025 
3026 after_reason:
3027 	return cmd->se_tfo->queue_status(cmd);
3028 }
3029 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3030 
3031 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3032 {
3033 	int ret = 0;
3034 
3035 	if (cmd->transport_state & CMD_T_ABORTED) {
3036 		if (!send_status ||
3037 		     (cmd->se_cmd_flags & SCF_SENT_DELAYED_TAS))
3038 			return 1;
3039 
3040 		pr_debug("Sending delayed SAM_STAT_TASK_ABORTED"
3041 			" status for CDB: 0x%02x ITT: 0x%08x\n",
3042 			cmd->t_task_cdb[0],
3043 			cmd->se_tfo->get_task_tag(cmd));
3044 
3045 		cmd->se_cmd_flags |= SCF_SENT_DELAYED_TAS;
3046 		cmd->se_tfo->queue_status(cmd);
3047 		ret = 1;
3048 	}
3049 	return ret;
3050 }
3051 EXPORT_SYMBOL(transport_check_aborted_status);
3052 
3053 void transport_send_task_abort(struct se_cmd *cmd)
3054 {
3055 	unsigned long flags;
3056 
3057 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3058 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
3059 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3060 		return;
3061 	}
3062 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3063 
3064 	/*
3065 	 * If there are still expected incoming fabric WRITEs, we wait
3066 	 * until until they have completed before sending a TASK_ABORTED
3067 	 * response.  This response with TASK_ABORTED status will be
3068 	 * queued back to fabric module by transport_check_aborted_status().
3069 	 */
3070 	if (cmd->data_direction == DMA_TO_DEVICE) {
3071 		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3072 			cmd->transport_state |= CMD_T_ABORTED;
3073 			smp_mb__after_atomic_inc();
3074 		}
3075 	}
3076 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3077 
3078 	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
3079 		" ITT: 0x%08x\n", cmd->t_task_cdb[0],
3080 		cmd->se_tfo->get_task_tag(cmd));
3081 
3082 	cmd->se_tfo->queue_status(cmd);
3083 }
3084 
3085 static void target_tmr_work(struct work_struct *work)
3086 {
3087 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3088 	struct se_device *dev = cmd->se_dev;
3089 	struct se_tmr_req *tmr = cmd->se_tmr_req;
3090 	int ret;
3091 
3092 	switch (tmr->function) {
3093 	case TMR_ABORT_TASK:
3094 		core_tmr_abort_task(dev, tmr, cmd->se_sess);
3095 		break;
3096 	case TMR_ABORT_TASK_SET:
3097 	case TMR_CLEAR_ACA:
3098 	case TMR_CLEAR_TASK_SET:
3099 		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3100 		break;
3101 	case TMR_LUN_RESET:
3102 		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3103 		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3104 					 TMR_FUNCTION_REJECTED;
3105 		break;
3106 	case TMR_TARGET_WARM_RESET:
3107 		tmr->response = TMR_FUNCTION_REJECTED;
3108 		break;
3109 	case TMR_TARGET_COLD_RESET:
3110 		tmr->response = TMR_FUNCTION_REJECTED;
3111 		break;
3112 	default:
3113 		pr_err("Uknown TMR function: 0x%02x.\n",
3114 				tmr->function);
3115 		tmr->response = TMR_FUNCTION_REJECTED;
3116 		break;
3117 	}
3118 
3119 	cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3120 	cmd->se_tfo->queue_tm_rsp(cmd);
3121 
3122 	transport_cmd_check_stop_to_fabric(cmd);
3123 }
3124 
3125 int transport_generic_handle_tmr(
3126 	struct se_cmd *cmd)
3127 {
3128 	INIT_WORK(&cmd->work, target_tmr_work);
3129 	queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3130 	return 0;
3131 }
3132 EXPORT_SYMBOL(transport_generic_handle_tmr);
3133