xref: /linux/drivers/target/target_core_transport.c (revision 95e9fd10f06cb5642028b6b851e32b8c8afb4571)
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 		if (cmd->data_direction == DMA_TO_DEVICE) {
1169 			pr_err("Rejecting underflow/overflow"
1170 					" WRITE data\n");
1171 			goto out_invalid_cdb_field;
1172 		}
1173 		/*
1174 		 * Reject READ_* or WRITE_* with overflow/underflow for
1175 		 * type SCF_SCSI_DATA_CDB.
1176 		 */
1177 		if (dev->se_sub_dev->se_dev_attrib.block_size != 512)  {
1178 			pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1179 				" CDB on non 512-byte sector setup subsystem"
1180 				" plugin: %s\n", dev->transport->name);
1181 			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1182 			goto out_invalid_cdb_field;
1183 		}
1184 
1185 		if (size > cmd->data_length) {
1186 			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1187 			cmd->residual_count = (size - cmd->data_length);
1188 		} else {
1189 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1190 			cmd->residual_count = (cmd->data_length - size);
1191 		}
1192 		cmd->data_length = size;
1193 	}
1194 
1195 	return 0;
1196 
1197 out_invalid_cdb_field:
1198 	cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1199 	cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
1200 	return -EINVAL;
1201 }
1202 
1203 /*
1204  * Used by fabric modules containing a local struct se_cmd within their
1205  * fabric dependent per I/O descriptor.
1206  */
1207 void transport_init_se_cmd(
1208 	struct se_cmd *cmd,
1209 	struct target_core_fabric_ops *tfo,
1210 	struct se_session *se_sess,
1211 	u32 data_length,
1212 	int data_direction,
1213 	int task_attr,
1214 	unsigned char *sense_buffer)
1215 {
1216 	INIT_LIST_HEAD(&cmd->se_lun_node);
1217 	INIT_LIST_HEAD(&cmd->se_delayed_node);
1218 	INIT_LIST_HEAD(&cmd->se_qf_node);
1219 	INIT_LIST_HEAD(&cmd->se_cmd_list);
1220 	INIT_LIST_HEAD(&cmd->state_list);
1221 	init_completion(&cmd->transport_lun_fe_stop_comp);
1222 	init_completion(&cmd->transport_lun_stop_comp);
1223 	init_completion(&cmd->t_transport_stop_comp);
1224 	init_completion(&cmd->cmd_wait_comp);
1225 	init_completion(&cmd->task_stop_comp);
1226 	spin_lock_init(&cmd->t_state_lock);
1227 	cmd->transport_state = CMD_T_DEV_ACTIVE;
1228 
1229 	cmd->se_tfo = tfo;
1230 	cmd->se_sess = se_sess;
1231 	cmd->data_length = data_length;
1232 	cmd->data_direction = data_direction;
1233 	cmd->sam_task_attr = task_attr;
1234 	cmd->sense_buffer = sense_buffer;
1235 
1236 	cmd->state_active = false;
1237 }
1238 EXPORT_SYMBOL(transport_init_se_cmd);
1239 
1240 static int transport_check_alloc_task_attr(struct se_cmd *cmd)
1241 {
1242 	/*
1243 	 * Check if SAM Task Attribute emulation is enabled for this
1244 	 * struct se_device storage object
1245 	 */
1246 	if (cmd->se_dev->dev_task_attr_type != SAM_TASK_ATTR_EMULATED)
1247 		return 0;
1248 
1249 	if (cmd->sam_task_attr == MSG_ACA_TAG) {
1250 		pr_debug("SAM Task Attribute ACA"
1251 			" emulation is not supported\n");
1252 		return -EINVAL;
1253 	}
1254 	/*
1255 	 * Used to determine when ORDERED commands should go from
1256 	 * Dormant to Active status.
1257 	 */
1258 	cmd->se_ordered_id = atomic_inc_return(&cmd->se_dev->dev_ordered_id);
1259 	smp_mb__after_atomic_inc();
1260 	pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
1261 			cmd->se_ordered_id, cmd->sam_task_attr,
1262 			cmd->se_dev->transport->name);
1263 	return 0;
1264 }
1265 
1266 /*	target_setup_cmd_from_cdb():
1267  *
1268  *	Called from fabric RX Thread.
1269  */
1270 int target_setup_cmd_from_cdb(
1271 	struct se_cmd *cmd,
1272 	unsigned char *cdb)
1273 {
1274 	struct se_subsystem_dev *su_dev = cmd->se_dev->se_sub_dev;
1275 	u32 pr_reg_type = 0;
1276 	u8 alua_ascq = 0;
1277 	unsigned long flags;
1278 	int ret;
1279 
1280 	/*
1281 	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1282 	 * for VARIABLE_LENGTH_CMD
1283 	 */
1284 	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1285 		pr_err("Received SCSI CDB with command_size: %d that"
1286 			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1287 			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1288 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1289 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
1290 		return -EINVAL;
1291 	}
1292 	/*
1293 	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1294 	 * allocate the additional extended CDB buffer now..  Otherwise
1295 	 * setup the pointer from __t_task_cdb to t_task_cdb.
1296 	 */
1297 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1298 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1299 						GFP_KERNEL);
1300 		if (!cmd->t_task_cdb) {
1301 			pr_err("Unable to allocate cmd->t_task_cdb"
1302 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1303 				scsi_command_size(cdb),
1304 				(unsigned long)sizeof(cmd->__t_task_cdb));
1305 			cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1306 			cmd->scsi_sense_reason =
1307 					TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1308 			return -ENOMEM;
1309 		}
1310 	} else
1311 		cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1312 	/*
1313 	 * Copy the original CDB into cmd->
1314 	 */
1315 	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1316 
1317 	/*
1318 	 * Check for an existing UNIT ATTENTION condition
1319 	 */
1320 	if (core_scsi3_ua_check(cmd, cdb) < 0) {
1321 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1322 		cmd->scsi_sense_reason = TCM_CHECK_CONDITION_UNIT_ATTENTION;
1323 		return -EINVAL;
1324 	}
1325 
1326 	ret = su_dev->t10_alua.alua_state_check(cmd, cdb, &alua_ascq);
1327 	if (ret != 0) {
1328 		/*
1329 		 * Set SCSI additional sense code (ASC) to 'LUN Not Accessible';
1330 		 * The ALUA additional sense code qualifier (ASCQ) is determined
1331 		 * by the ALUA primary or secondary access state..
1332 		 */
1333 		if (ret > 0) {
1334 			pr_debug("[%s]: ALUA TG Port not available, "
1335 				"SenseKey: NOT_READY, ASC/ASCQ: "
1336 				"0x04/0x%02x\n",
1337 				cmd->se_tfo->get_fabric_name(), alua_ascq);
1338 
1339 			transport_set_sense_codes(cmd, 0x04, alua_ascq);
1340 			cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1341 			cmd->scsi_sense_reason = TCM_CHECK_CONDITION_NOT_READY;
1342 			return -EINVAL;
1343 		}
1344 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1345 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
1346 		return -EINVAL;
1347 	}
1348 
1349 	/*
1350 	 * Check status for SPC-3 Persistent Reservations
1351 	 */
1352 	if (su_dev->t10_pr.pr_ops.t10_reservation_check(cmd, &pr_reg_type)) {
1353 		if (su_dev->t10_pr.pr_ops.t10_seq_non_holder(
1354 					cmd, cdb, pr_reg_type) != 0) {
1355 			cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1356 			cmd->se_cmd_flags |= SCF_SCSI_RESERVATION_CONFLICT;
1357 			cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1358 			cmd->scsi_sense_reason = TCM_RESERVATION_CONFLICT;
1359 			return -EBUSY;
1360 		}
1361 		/*
1362 		 * This means the CDB is allowed for the SCSI Initiator port
1363 		 * when said port is *NOT* holding the legacy SPC-2 or
1364 		 * SPC-3 Persistent Reservation.
1365 		 */
1366 	}
1367 
1368 	ret = cmd->se_dev->transport->parse_cdb(cmd);
1369 	if (ret < 0)
1370 		return ret;
1371 
1372 	spin_lock_irqsave(&cmd->t_state_lock, flags);
1373 	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1374 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1375 
1376 	/*
1377 	 * Check for SAM Task Attribute Emulation
1378 	 */
1379 	if (transport_check_alloc_task_attr(cmd) < 0) {
1380 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
1381 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
1382 		return -EINVAL;
1383 	}
1384 	spin_lock(&cmd->se_lun->lun_sep_lock);
1385 	if (cmd->se_lun->lun_sep)
1386 		cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
1387 	spin_unlock(&cmd->se_lun->lun_sep_lock);
1388 	return 0;
1389 }
1390 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1391 
1392 /*
1393  * Used by fabric module frontends to queue tasks directly.
1394  * Many only be used from process context only
1395  */
1396 int transport_handle_cdb_direct(
1397 	struct se_cmd *cmd)
1398 {
1399 	int ret;
1400 
1401 	if (!cmd->se_lun) {
1402 		dump_stack();
1403 		pr_err("cmd->se_lun is NULL\n");
1404 		return -EINVAL;
1405 	}
1406 	if (in_interrupt()) {
1407 		dump_stack();
1408 		pr_err("transport_generic_handle_cdb cannot be called"
1409 				" from interrupt context\n");
1410 		return -EINVAL;
1411 	}
1412 	/*
1413 	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1414 	 * outstanding descriptors are handled correctly during shutdown via
1415 	 * transport_wait_for_tasks()
1416 	 *
1417 	 * Also, we don't take cmd->t_state_lock here as we only expect
1418 	 * this to be called for initial descriptor submission.
1419 	 */
1420 	cmd->t_state = TRANSPORT_NEW_CMD;
1421 	cmd->transport_state |= CMD_T_ACTIVE;
1422 
1423 	/*
1424 	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1425 	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1426 	 * and call transport_generic_request_failure() if necessary..
1427 	 */
1428 	ret = transport_generic_new_cmd(cmd);
1429 	if (ret < 0)
1430 		transport_generic_request_failure(cmd);
1431 
1432 	return 0;
1433 }
1434 EXPORT_SYMBOL(transport_handle_cdb_direct);
1435 
1436 /**
1437  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1438  *
1439  * @se_cmd: command descriptor to submit
1440  * @se_sess: associated se_sess for endpoint
1441  * @cdb: pointer to SCSI CDB
1442  * @sense: pointer to SCSI sense buffer
1443  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1444  * @data_length: fabric expected data transfer length
1445  * @task_addr: SAM task attribute
1446  * @data_dir: DMA data direction
1447  * @flags: flags for command submission from target_sc_flags_tables
1448  *
1449  * Returns non zero to signal active I/O shutdown failure.  All other
1450  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1451  * but still return zero here.
1452  *
1453  * This may only be called from process context, and also currently
1454  * assumes internal allocation of fabric payload buffer by target-core.
1455  **/
1456 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1457 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1458 		u32 data_length, int task_attr, int data_dir, int flags)
1459 {
1460 	struct se_portal_group *se_tpg;
1461 	int rc;
1462 
1463 	se_tpg = se_sess->se_tpg;
1464 	BUG_ON(!se_tpg);
1465 	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1466 	BUG_ON(in_interrupt());
1467 	/*
1468 	 * Initialize se_cmd for target operation.  From this point
1469 	 * exceptions are handled by sending exception status via
1470 	 * target_core_fabric_ops->queue_status() callback
1471 	 */
1472 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1473 				data_length, data_dir, task_attr, sense);
1474 	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1475 		se_cmd->unknown_data_length = 1;
1476 	/*
1477 	 * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1478 	 * se_sess->sess_cmd_list.  A second kref_get here is necessary
1479 	 * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1480 	 * kref_put() to happen during fabric packet acknowledgement.
1481 	 */
1482 	rc = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1483 	if (rc)
1484 		return rc;
1485 	/*
1486 	 * Signal bidirectional data payloads to target-core
1487 	 */
1488 	if (flags & TARGET_SCF_BIDI_OP)
1489 		se_cmd->se_cmd_flags |= SCF_BIDI;
1490 	/*
1491 	 * Locate se_lun pointer and attach it to struct se_cmd
1492 	 */
1493 	if (transport_lookup_cmd_lun(se_cmd, unpacked_lun) < 0) {
1494 		transport_send_check_condition_and_sense(se_cmd,
1495 				se_cmd->scsi_sense_reason, 0);
1496 		target_put_sess_cmd(se_sess, se_cmd);
1497 		return 0;
1498 	}
1499 
1500 	rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1501 	if (rc != 0) {
1502 		transport_generic_request_failure(se_cmd);
1503 		return 0;
1504 	}
1505 
1506 	/*
1507 	 * Check if we need to delay processing because of ALUA
1508 	 * Active/NonOptimized primary access state..
1509 	 */
1510 	core_alua_check_nonop_delay(se_cmd);
1511 
1512 	transport_handle_cdb_direct(se_cmd);
1513 	return 0;
1514 }
1515 EXPORT_SYMBOL(target_submit_cmd);
1516 
1517 static void target_complete_tmr_failure(struct work_struct *work)
1518 {
1519 	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1520 
1521 	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1522 	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1523 	transport_generic_free_cmd(se_cmd, 0);
1524 }
1525 
1526 /**
1527  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1528  *                     for TMR CDBs
1529  *
1530  * @se_cmd: command descriptor to submit
1531  * @se_sess: associated se_sess for endpoint
1532  * @sense: pointer to SCSI sense buffer
1533  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1534  * @fabric_context: fabric context for TMR req
1535  * @tm_type: Type of TM request
1536  * @gfp: gfp type for caller
1537  * @tag: referenced task tag for TMR_ABORT_TASK
1538  * @flags: submit cmd flags
1539  *
1540  * Callable from all contexts.
1541  **/
1542 
1543 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1544 		unsigned char *sense, u32 unpacked_lun,
1545 		void *fabric_tmr_ptr, unsigned char tm_type,
1546 		gfp_t gfp, unsigned int tag, int flags)
1547 {
1548 	struct se_portal_group *se_tpg;
1549 	int ret;
1550 
1551 	se_tpg = se_sess->se_tpg;
1552 	BUG_ON(!se_tpg);
1553 
1554 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1555 			      0, DMA_NONE, MSG_SIMPLE_TAG, sense);
1556 	/*
1557 	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1558 	 * allocation failure.
1559 	 */
1560 	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1561 	if (ret < 0)
1562 		return -ENOMEM;
1563 
1564 	if (tm_type == TMR_ABORT_TASK)
1565 		se_cmd->se_tmr_req->ref_task_tag = tag;
1566 
1567 	/* See target_submit_cmd for commentary */
1568 	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1569 	if (ret) {
1570 		core_tmr_release_req(se_cmd->se_tmr_req);
1571 		return ret;
1572 	}
1573 
1574 	ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1575 	if (ret) {
1576 		/*
1577 		 * For callback during failure handling, push this work off
1578 		 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1579 		 */
1580 		INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1581 		schedule_work(&se_cmd->work);
1582 		return 0;
1583 	}
1584 	transport_generic_handle_tmr(se_cmd);
1585 	return 0;
1586 }
1587 EXPORT_SYMBOL(target_submit_tmr);
1588 
1589 /*
1590  * If the cmd is active, request it to be stopped and sleep until it
1591  * has completed.
1592  */
1593 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1594 {
1595 	bool was_active = false;
1596 
1597 	if (cmd->transport_state & CMD_T_BUSY) {
1598 		cmd->transport_state |= CMD_T_REQUEST_STOP;
1599 		spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1600 
1601 		pr_debug("cmd %p waiting to complete\n", cmd);
1602 		wait_for_completion(&cmd->task_stop_comp);
1603 		pr_debug("cmd %p stopped successfully\n", cmd);
1604 
1605 		spin_lock_irqsave(&cmd->t_state_lock, *flags);
1606 		cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1607 		cmd->transport_state &= ~CMD_T_BUSY;
1608 		was_active = true;
1609 	}
1610 
1611 	return was_active;
1612 }
1613 
1614 /*
1615  * Handle SAM-esque emulation for generic transport request failures.
1616  */
1617 void transport_generic_request_failure(struct se_cmd *cmd)
1618 {
1619 	int ret = 0;
1620 
1621 	pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
1622 		" CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
1623 		cmd->t_task_cdb[0]);
1624 	pr_debug("-----[ i_state: %d t_state: %d scsi_sense_reason: %d\n",
1625 		cmd->se_tfo->get_cmd_state(cmd),
1626 		cmd->t_state, cmd->scsi_sense_reason);
1627 	pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1628 		(cmd->transport_state & CMD_T_ACTIVE) != 0,
1629 		(cmd->transport_state & CMD_T_STOP) != 0,
1630 		(cmd->transport_state & CMD_T_SENT) != 0);
1631 
1632 	/*
1633 	 * For SAM Task Attribute emulation for failed struct se_cmd
1634 	 */
1635 	if (cmd->se_dev->dev_task_attr_type == SAM_TASK_ATTR_EMULATED)
1636 		transport_complete_task_attr(cmd);
1637 
1638 	switch (cmd->scsi_sense_reason) {
1639 	case TCM_NON_EXISTENT_LUN:
1640 	case TCM_UNSUPPORTED_SCSI_OPCODE:
1641 	case TCM_INVALID_CDB_FIELD:
1642 	case TCM_INVALID_PARAMETER_LIST:
1643 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1644 	case TCM_UNKNOWN_MODE_PAGE:
1645 	case TCM_WRITE_PROTECTED:
1646 	case TCM_ADDRESS_OUT_OF_RANGE:
1647 	case TCM_CHECK_CONDITION_ABORT_CMD:
1648 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1649 	case TCM_CHECK_CONDITION_NOT_READY:
1650 		break;
1651 	case TCM_RESERVATION_CONFLICT:
1652 		/*
1653 		 * No SENSE Data payload for this case, set SCSI Status
1654 		 * and queue the response to $FABRIC_MOD.
1655 		 *
1656 		 * Uses linux/include/scsi/scsi.h SAM status codes defs
1657 		 */
1658 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1659 		/*
1660 		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1661 		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1662 		 * CONFLICT STATUS.
1663 		 *
1664 		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1665 		 */
1666 		if (cmd->se_sess &&
1667 		    cmd->se_dev->se_sub_dev->se_dev_attrib.emulate_ua_intlck_ctrl == 2)
1668 			core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
1669 				cmd->orig_fe_lun, 0x2C,
1670 				ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1671 
1672 		ret = cmd->se_tfo->queue_status(cmd);
1673 		if (ret == -EAGAIN || ret == -ENOMEM)
1674 			goto queue_full;
1675 		goto check_stop;
1676 	default:
1677 		pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1678 			cmd->t_task_cdb[0], cmd->scsi_sense_reason);
1679 		cmd->scsi_sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1680 		break;
1681 	}
1682 
1683 	ret = transport_send_check_condition_and_sense(cmd,
1684 			cmd->scsi_sense_reason, 0);
1685 	if (ret == -EAGAIN || ret == -ENOMEM)
1686 		goto queue_full;
1687 
1688 check_stop:
1689 	transport_lun_remove_cmd(cmd);
1690 	if (!transport_cmd_check_stop_to_fabric(cmd))
1691 		;
1692 	return;
1693 
1694 queue_full:
1695 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1696 	transport_handle_queue_full(cmd, cmd->se_dev);
1697 }
1698 EXPORT_SYMBOL(transport_generic_request_failure);
1699 
1700 static void __target_execute_cmd(struct se_cmd *cmd)
1701 {
1702 	int error = 0;
1703 
1704 	spin_lock_irq(&cmd->t_state_lock);
1705 	cmd->transport_state |= (CMD_T_BUSY|CMD_T_SENT);
1706 	spin_unlock_irq(&cmd->t_state_lock);
1707 
1708 	if (cmd->execute_cmd)
1709 		error = cmd->execute_cmd(cmd);
1710 
1711 	if (error) {
1712 		spin_lock_irq(&cmd->t_state_lock);
1713 		cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1714 		spin_unlock_irq(&cmd->t_state_lock);
1715 
1716 		transport_generic_request_failure(cmd);
1717 	}
1718 }
1719 
1720 void target_execute_cmd(struct se_cmd *cmd)
1721 {
1722 	struct se_device *dev = cmd->se_dev;
1723 
1724 	/*
1725 	 * If the received CDB has aleady been aborted stop processing it here.
1726 	 */
1727 	if (transport_check_aborted_status(cmd, 1))
1728 		return;
1729 
1730 	/*
1731 	 * Determine if IOCTL context caller in requesting the stopping of this
1732 	 * command for LUN shutdown purposes.
1733 	 */
1734 	spin_lock_irq(&cmd->t_state_lock);
1735 	if (cmd->transport_state & CMD_T_LUN_STOP) {
1736 		pr_debug("%s:%d CMD_T_LUN_STOP for ITT: 0x%08x\n",
1737 			__func__, __LINE__, cmd->se_tfo->get_task_tag(cmd));
1738 
1739 		cmd->transport_state &= ~CMD_T_ACTIVE;
1740 		spin_unlock_irq(&cmd->t_state_lock);
1741 		complete(&cmd->transport_lun_stop_comp);
1742 		return;
1743 	}
1744 	/*
1745 	 * Determine if frontend context caller is requesting the stopping of
1746 	 * this command for frontend exceptions.
1747 	 */
1748 	if (cmd->transport_state & CMD_T_STOP) {
1749 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
1750 			__func__, __LINE__,
1751 			cmd->se_tfo->get_task_tag(cmd));
1752 
1753 		spin_unlock_irq(&cmd->t_state_lock);
1754 		complete(&cmd->t_transport_stop_comp);
1755 		return;
1756 	}
1757 
1758 	cmd->t_state = TRANSPORT_PROCESSING;
1759 	spin_unlock_irq(&cmd->t_state_lock);
1760 
1761 	if (dev->dev_task_attr_type != SAM_TASK_ATTR_EMULATED)
1762 		goto execute;
1763 
1764 	/*
1765 	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1766 	 * to allow the passed struct se_cmd list of tasks to the front of the list.
1767 	 */
1768 	switch (cmd->sam_task_attr) {
1769 	case MSG_HEAD_TAG:
1770 		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
1771 			 "se_ordered_id: %u\n",
1772 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1773 		goto execute;
1774 	case MSG_ORDERED_TAG:
1775 		atomic_inc(&dev->dev_ordered_sync);
1776 		smp_mb__after_atomic_inc();
1777 
1778 		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
1779 			 " se_ordered_id: %u\n",
1780 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1781 
1782 		/*
1783 		 * Execute an ORDERED command if no other older commands
1784 		 * exist that need to be completed first.
1785 		 */
1786 		if (!atomic_read(&dev->simple_cmds))
1787 			goto execute;
1788 		break;
1789 	default:
1790 		/*
1791 		 * For SIMPLE and UNTAGGED Task Attribute commands
1792 		 */
1793 		atomic_inc(&dev->simple_cmds);
1794 		smp_mb__after_atomic_inc();
1795 		break;
1796 	}
1797 
1798 	if (atomic_read(&dev->dev_ordered_sync) != 0) {
1799 		spin_lock(&dev->delayed_cmd_lock);
1800 		list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1801 		spin_unlock(&dev->delayed_cmd_lock);
1802 
1803 		pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
1804 			" delayed CMD list, se_ordered_id: %u\n",
1805 			cmd->t_task_cdb[0], cmd->sam_task_attr,
1806 			cmd->se_ordered_id);
1807 		return;
1808 	}
1809 
1810 execute:
1811 	/*
1812 	 * Otherwise, no ORDERED task attributes exist..
1813 	 */
1814 	__target_execute_cmd(cmd);
1815 }
1816 EXPORT_SYMBOL(target_execute_cmd);
1817 
1818 /*
1819  * Used to obtain Sense Data from underlying Linux/SCSI struct scsi_cmnd
1820  */
1821 static int transport_get_sense_data(struct se_cmd *cmd)
1822 {
1823 	unsigned char *buffer = cmd->sense_buffer, *sense_buffer = NULL;
1824 	struct se_device *dev = cmd->se_dev;
1825 	unsigned long flags;
1826 	u32 offset = 0;
1827 
1828 	WARN_ON(!cmd->se_lun);
1829 
1830 	if (!dev)
1831 		return 0;
1832 
1833 	spin_lock_irqsave(&cmd->t_state_lock, flags);
1834 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
1835 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1836 		return 0;
1837 	}
1838 
1839 	if (!(cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE))
1840 		goto out;
1841 
1842 	if (!dev->transport->get_sense_buffer) {
1843 		pr_err("dev->transport->get_sense_buffer is NULL\n");
1844 		goto out;
1845 	}
1846 
1847 	sense_buffer = dev->transport->get_sense_buffer(cmd);
1848 	if (!sense_buffer) {
1849 		pr_err("ITT 0x%08x cmd %p: Unable to locate"
1850 			" sense buffer for task with sense\n",
1851 			cmd->se_tfo->get_task_tag(cmd), cmd);
1852 		goto out;
1853 	}
1854 
1855 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1856 
1857 	offset = cmd->se_tfo->set_fabric_sense_len(cmd, TRANSPORT_SENSE_BUFFER);
1858 
1859 	memcpy(&buffer[offset], sense_buffer, TRANSPORT_SENSE_BUFFER);
1860 
1861 	/* Automatically padded */
1862 	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER + offset;
1863 
1864 	pr_debug("HBA_[%u]_PLUG[%s]: Set SAM STATUS: 0x%02x and sense\n",
1865 		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
1866 	return 0;
1867 
1868 out:
1869 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
1870 	return -1;
1871 }
1872 
1873 /*
1874  * Process all commands up to the last received ORDERED task attribute which
1875  * requires another blocking boundary
1876  */
1877 static void target_restart_delayed_cmds(struct se_device *dev)
1878 {
1879 	for (;;) {
1880 		struct se_cmd *cmd;
1881 
1882 		spin_lock(&dev->delayed_cmd_lock);
1883 		if (list_empty(&dev->delayed_cmd_list)) {
1884 			spin_unlock(&dev->delayed_cmd_lock);
1885 			break;
1886 		}
1887 
1888 		cmd = list_entry(dev->delayed_cmd_list.next,
1889 				 struct se_cmd, se_delayed_node);
1890 		list_del(&cmd->se_delayed_node);
1891 		spin_unlock(&dev->delayed_cmd_lock);
1892 
1893 		__target_execute_cmd(cmd);
1894 
1895 		if (cmd->sam_task_attr == MSG_ORDERED_TAG)
1896 			break;
1897 	}
1898 }
1899 
1900 /*
1901  * Called from I/O completion to determine which dormant/delayed
1902  * and ordered cmds need to have their tasks added to the execution queue.
1903  */
1904 static void transport_complete_task_attr(struct se_cmd *cmd)
1905 {
1906 	struct se_device *dev = cmd->se_dev;
1907 
1908 	if (cmd->sam_task_attr == MSG_SIMPLE_TAG) {
1909 		atomic_dec(&dev->simple_cmds);
1910 		smp_mb__after_atomic_dec();
1911 		dev->dev_cur_ordered_id++;
1912 		pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
1913 			" SIMPLE: %u\n", dev->dev_cur_ordered_id,
1914 			cmd->se_ordered_id);
1915 	} else if (cmd->sam_task_attr == MSG_HEAD_TAG) {
1916 		dev->dev_cur_ordered_id++;
1917 		pr_debug("Incremented dev_cur_ordered_id: %u for"
1918 			" HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
1919 			cmd->se_ordered_id);
1920 	} else if (cmd->sam_task_attr == MSG_ORDERED_TAG) {
1921 		atomic_dec(&dev->dev_ordered_sync);
1922 		smp_mb__after_atomic_dec();
1923 
1924 		dev->dev_cur_ordered_id++;
1925 		pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
1926 			" %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
1927 	}
1928 
1929 	target_restart_delayed_cmds(dev);
1930 }
1931 
1932 static void transport_complete_qf(struct se_cmd *cmd)
1933 {
1934 	int ret = 0;
1935 
1936 	if (cmd->se_dev->dev_task_attr_type == SAM_TASK_ATTR_EMULATED)
1937 		transport_complete_task_attr(cmd);
1938 
1939 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1940 		ret = cmd->se_tfo->queue_status(cmd);
1941 		if (ret)
1942 			goto out;
1943 	}
1944 
1945 	switch (cmd->data_direction) {
1946 	case DMA_FROM_DEVICE:
1947 		ret = cmd->se_tfo->queue_data_in(cmd);
1948 		break;
1949 	case DMA_TO_DEVICE:
1950 		if (cmd->t_bidi_data_sg) {
1951 			ret = cmd->se_tfo->queue_data_in(cmd);
1952 			if (ret < 0)
1953 				break;
1954 		}
1955 		/* Fall through for DMA_TO_DEVICE */
1956 	case DMA_NONE:
1957 		ret = cmd->se_tfo->queue_status(cmd);
1958 		break;
1959 	default:
1960 		break;
1961 	}
1962 
1963 out:
1964 	if (ret < 0) {
1965 		transport_handle_queue_full(cmd, cmd->se_dev);
1966 		return;
1967 	}
1968 	transport_lun_remove_cmd(cmd);
1969 	transport_cmd_check_stop_to_fabric(cmd);
1970 }
1971 
1972 static void transport_handle_queue_full(
1973 	struct se_cmd *cmd,
1974 	struct se_device *dev)
1975 {
1976 	spin_lock_irq(&dev->qf_cmd_lock);
1977 	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
1978 	atomic_inc(&dev->dev_qf_count);
1979 	smp_mb__after_atomic_inc();
1980 	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
1981 
1982 	schedule_work(&cmd->se_dev->qf_work_queue);
1983 }
1984 
1985 static void target_complete_ok_work(struct work_struct *work)
1986 {
1987 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
1988 	int reason = 0, ret;
1989 
1990 	/*
1991 	 * Check if we need to move delayed/dormant tasks from cmds on the
1992 	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
1993 	 * Attribute.
1994 	 */
1995 	if (cmd->se_dev->dev_task_attr_type == SAM_TASK_ATTR_EMULATED)
1996 		transport_complete_task_attr(cmd);
1997 	/*
1998 	 * Check to schedule QUEUE_FULL work, or execute an existing
1999 	 * cmd->transport_qf_callback()
2000 	 */
2001 	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2002 		schedule_work(&cmd->se_dev->qf_work_queue);
2003 
2004 	/*
2005 	 * Check if we need to retrieve a sense buffer from
2006 	 * the struct se_cmd in question.
2007 	 */
2008 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2009 		if (transport_get_sense_data(cmd) < 0)
2010 			reason = TCM_NON_EXISTENT_LUN;
2011 
2012 		if (cmd->scsi_status) {
2013 			ret = transport_send_check_condition_and_sense(
2014 					cmd, reason, 1);
2015 			if (ret == -EAGAIN || ret == -ENOMEM)
2016 				goto queue_full;
2017 
2018 			transport_lun_remove_cmd(cmd);
2019 			transport_cmd_check_stop_to_fabric(cmd);
2020 			return;
2021 		}
2022 	}
2023 	/*
2024 	 * Check for a callback, used by amongst other things
2025 	 * XDWRITE_READ_10 emulation.
2026 	 */
2027 	if (cmd->transport_complete_callback)
2028 		cmd->transport_complete_callback(cmd);
2029 
2030 	switch (cmd->data_direction) {
2031 	case DMA_FROM_DEVICE:
2032 		spin_lock(&cmd->se_lun->lun_sep_lock);
2033 		if (cmd->se_lun->lun_sep) {
2034 			cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
2035 					cmd->data_length;
2036 		}
2037 		spin_unlock(&cmd->se_lun->lun_sep_lock);
2038 
2039 		ret = cmd->se_tfo->queue_data_in(cmd);
2040 		if (ret == -EAGAIN || ret == -ENOMEM)
2041 			goto queue_full;
2042 		break;
2043 	case DMA_TO_DEVICE:
2044 		spin_lock(&cmd->se_lun->lun_sep_lock);
2045 		if (cmd->se_lun->lun_sep) {
2046 			cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
2047 				cmd->data_length;
2048 		}
2049 		spin_unlock(&cmd->se_lun->lun_sep_lock);
2050 		/*
2051 		 * Check if we need to send READ payload for BIDI-COMMAND
2052 		 */
2053 		if (cmd->t_bidi_data_sg) {
2054 			spin_lock(&cmd->se_lun->lun_sep_lock);
2055 			if (cmd->se_lun->lun_sep) {
2056 				cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
2057 					cmd->data_length;
2058 			}
2059 			spin_unlock(&cmd->se_lun->lun_sep_lock);
2060 			ret = cmd->se_tfo->queue_data_in(cmd);
2061 			if (ret == -EAGAIN || ret == -ENOMEM)
2062 				goto queue_full;
2063 			break;
2064 		}
2065 		/* Fall through for DMA_TO_DEVICE */
2066 	case DMA_NONE:
2067 		ret = cmd->se_tfo->queue_status(cmd);
2068 		if (ret == -EAGAIN || ret == -ENOMEM)
2069 			goto queue_full;
2070 		break;
2071 	default:
2072 		break;
2073 	}
2074 
2075 	transport_lun_remove_cmd(cmd);
2076 	transport_cmd_check_stop_to_fabric(cmd);
2077 	return;
2078 
2079 queue_full:
2080 	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2081 		" data_direction: %d\n", cmd, cmd->data_direction);
2082 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2083 	transport_handle_queue_full(cmd, cmd->se_dev);
2084 }
2085 
2086 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
2087 {
2088 	struct scatterlist *sg;
2089 	int count;
2090 
2091 	for_each_sg(sgl, sg, nents, count)
2092 		__free_page(sg_page(sg));
2093 
2094 	kfree(sgl);
2095 }
2096 
2097 static inline void transport_free_pages(struct se_cmd *cmd)
2098 {
2099 	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC)
2100 		return;
2101 
2102 	transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2103 	cmd->t_data_sg = NULL;
2104 	cmd->t_data_nents = 0;
2105 
2106 	transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2107 	cmd->t_bidi_data_sg = NULL;
2108 	cmd->t_bidi_data_nents = 0;
2109 }
2110 
2111 /**
2112  * transport_release_cmd - free a command
2113  * @cmd:       command to free
2114  *
2115  * This routine unconditionally frees a command, and reference counting
2116  * or list removal must be done in the caller.
2117  */
2118 static void transport_release_cmd(struct se_cmd *cmd)
2119 {
2120 	BUG_ON(!cmd->se_tfo);
2121 
2122 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2123 		core_tmr_release_req(cmd->se_tmr_req);
2124 	if (cmd->t_task_cdb != cmd->__t_task_cdb)
2125 		kfree(cmd->t_task_cdb);
2126 	/*
2127 	 * If this cmd has been setup with target_get_sess_cmd(), drop
2128 	 * the kref and call ->release_cmd() in kref callback.
2129 	 */
2130 	 if (cmd->check_release != 0) {
2131 		target_put_sess_cmd(cmd->se_sess, cmd);
2132 		return;
2133 	}
2134 	cmd->se_tfo->release_cmd(cmd);
2135 }
2136 
2137 /**
2138  * transport_put_cmd - release a reference to a command
2139  * @cmd:       command to release
2140  *
2141  * This routine releases our reference to the command and frees it if possible.
2142  */
2143 static void transport_put_cmd(struct se_cmd *cmd)
2144 {
2145 	unsigned long flags;
2146 
2147 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2148 	if (atomic_read(&cmd->t_fe_count)) {
2149 		if (!atomic_dec_and_test(&cmd->t_fe_count))
2150 			goto out_busy;
2151 	}
2152 
2153 	if (cmd->transport_state & CMD_T_DEV_ACTIVE) {
2154 		cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
2155 		target_remove_from_state_list(cmd);
2156 	}
2157 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2158 
2159 	transport_free_pages(cmd);
2160 	transport_release_cmd(cmd);
2161 	return;
2162 out_busy:
2163 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2164 }
2165 
2166 /*
2167  * transport_generic_map_mem_to_cmd - Use fabric-alloced pages instead of
2168  * allocating in the core.
2169  * @cmd:  Associated se_cmd descriptor
2170  * @mem:  SGL style memory for TCM WRITE / READ
2171  * @sg_mem_num: Number of SGL elements
2172  * @mem_bidi_in: SGL style memory for TCM BIDI READ
2173  * @sg_mem_bidi_num: Number of BIDI READ SGL elements
2174  *
2175  * Return: nonzero return cmd was rejected for -ENOMEM or inproper usage
2176  * of parameters.
2177  */
2178 int transport_generic_map_mem_to_cmd(
2179 	struct se_cmd *cmd,
2180 	struct scatterlist *sgl,
2181 	u32 sgl_count,
2182 	struct scatterlist *sgl_bidi,
2183 	u32 sgl_bidi_count)
2184 {
2185 	if (!sgl || !sgl_count)
2186 		return 0;
2187 
2188 	/*
2189 	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
2190 	 * scatterlists already have been set to follow what the fabric
2191 	 * passes for the original expected data transfer length.
2192 	 */
2193 	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
2194 		pr_warn("Rejecting SCSI DATA overflow for fabric using"
2195 			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
2196 		cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
2197 		cmd->scsi_sense_reason = TCM_INVALID_CDB_FIELD;
2198 		return -EINVAL;
2199 	}
2200 
2201 	cmd->t_data_sg = sgl;
2202 	cmd->t_data_nents = sgl_count;
2203 
2204 	if (sgl_bidi && sgl_bidi_count) {
2205 		cmd->t_bidi_data_sg = sgl_bidi;
2206 		cmd->t_bidi_data_nents = sgl_bidi_count;
2207 	}
2208 	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
2209 	return 0;
2210 }
2211 EXPORT_SYMBOL(transport_generic_map_mem_to_cmd);
2212 
2213 void *transport_kmap_data_sg(struct se_cmd *cmd)
2214 {
2215 	struct scatterlist *sg = cmd->t_data_sg;
2216 	struct page **pages;
2217 	int i;
2218 
2219 	BUG_ON(!sg);
2220 	/*
2221 	 * We need to take into account a possible offset here for fabrics like
2222 	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2223 	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2224 	 */
2225 	if (!cmd->t_data_nents)
2226 		return NULL;
2227 	else if (cmd->t_data_nents == 1)
2228 		return kmap(sg_page(sg)) + sg->offset;
2229 
2230 	/* >1 page. use vmap */
2231 	pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2232 	if (!pages)
2233 		return NULL;
2234 
2235 	/* convert sg[] to pages[] */
2236 	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2237 		pages[i] = sg_page(sg);
2238 	}
2239 
2240 	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2241 	kfree(pages);
2242 	if (!cmd->t_data_vmap)
2243 		return NULL;
2244 
2245 	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2246 }
2247 EXPORT_SYMBOL(transport_kmap_data_sg);
2248 
2249 void transport_kunmap_data_sg(struct se_cmd *cmd)
2250 {
2251 	if (!cmd->t_data_nents) {
2252 		return;
2253 	} else if (cmd->t_data_nents == 1) {
2254 		kunmap(sg_page(cmd->t_data_sg));
2255 		return;
2256 	}
2257 
2258 	vunmap(cmd->t_data_vmap);
2259 	cmd->t_data_vmap = NULL;
2260 }
2261 EXPORT_SYMBOL(transport_kunmap_data_sg);
2262 
2263 static int
2264 transport_generic_get_mem(struct se_cmd *cmd)
2265 {
2266 	u32 length = cmd->data_length;
2267 	unsigned int nents;
2268 	struct page *page;
2269 	gfp_t zero_flag;
2270 	int i = 0;
2271 
2272 	nents = DIV_ROUND_UP(length, PAGE_SIZE);
2273 	cmd->t_data_sg = kmalloc(sizeof(struct scatterlist) * nents, GFP_KERNEL);
2274 	if (!cmd->t_data_sg)
2275 		return -ENOMEM;
2276 
2277 	cmd->t_data_nents = nents;
2278 	sg_init_table(cmd->t_data_sg, nents);
2279 
2280 	zero_flag = cmd->se_cmd_flags & SCF_SCSI_DATA_CDB ? 0 : __GFP_ZERO;
2281 
2282 	while (length) {
2283 		u32 page_len = min_t(u32, length, PAGE_SIZE);
2284 		page = alloc_page(GFP_KERNEL | zero_flag);
2285 		if (!page)
2286 			goto out;
2287 
2288 		sg_set_page(&cmd->t_data_sg[i], page, page_len, 0);
2289 		length -= page_len;
2290 		i++;
2291 	}
2292 	return 0;
2293 
2294 out:
2295 	while (i > 0) {
2296 		i--;
2297 		__free_page(sg_page(&cmd->t_data_sg[i]));
2298 	}
2299 	kfree(cmd->t_data_sg);
2300 	cmd->t_data_sg = NULL;
2301 	return -ENOMEM;
2302 }
2303 
2304 /*
2305  * Allocate any required resources to execute the command.  For writes we
2306  * might not have the payload yet, so notify the fabric via a call to
2307  * ->write_pending instead. Otherwise place it on the execution queue.
2308  */
2309 int transport_generic_new_cmd(struct se_cmd *cmd)
2310 {
2311 	int ret = 0;
2312 
2313 	/*
2314 	 * Determine is the TCM fabric module has already allocated physical
2315 	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2316 	 * beforehand.
2317 	 */
2318 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2319 	    cmd->data_length) {
2320 		ret = transport_generic_get_mem(cmd);
2321 		if (ret < 0)
2322 			goto out_fail;
2323 	}
2324 	/*
2325 	 * If this command doesn't have any payload and we don't have to call
2326 	 * into the fabric for data transfers, go ahead and complete it right
2327 	 * away.
2328 	 */
2329 	if (!cmd->data_length) {
2330 		spin_lock_irq(&cmd->t_state_lock);
2331 		cmd->t_state = TRANSPORT_COMPLETE;
2332 		cmd->transport_state |= CMD_T_ACTIVE;
2333 		spin_unlock_irq(&cmd->t_state_lock);
2334 
2335 		if (cmd->t_task_cdb[0] == REQUEST_SENSE) {
2336 			u8 ua_asc = 0, ua_ascq = 0;
2337 
2338 			core_scsi3_ua_clear_for_request_sense(cmd,
2339 					&ua_asc, &ua_ascq);
2340 		}
2341 
2342 		INIT_WORK(&cmd->work, target_complete_ok_work);
2343 		queue_work(target_completion_wq, &cmd->work);
2344 		return 0;
2345 	}
2346 
2347 	atomic_inc(&cmd->t_fe_count);
2348 
2349 	/*
2350 	 * If this command is not a write we can execute it right here,
2351 	 * for write buffers we need to notify the fabric driver first
2352 	 * and let it call back once the write buffers are ready.
2353 	 */
2354 	target_add_to_state_list(cmd);
2355 	if (cmd->data_direction != DMA_TO_DEVICE) {
2356 		target_execute_cmd(cmd);
2357 		return 0;
2358 	}
2359 
2360 	spin_lock_irq(&cmd->t_state_lock);
2361 	cmd->t_state = TRANSPORT_WRITE_PENDING;
2362 	spin_unlock_irq(&cmd->t_state_lock);
2363 
2364 	transport_cmd_check_stop(cmd, false);
2365 
2366 	ret = cmd->se_tfo->write_pending(cmd);
2367 	if (ret == -EAGAIN || ret == -ENOMEM)
2368 		goto queue_full;
2369 
2370 	if (ret < 0)
2371 		return ret;
2372 	return 1;
2373 
2374 out_fail:
2375 	cmd->se_cmd_flags |= SCF_SCSI_CDB_EXCEPTION;
2376 	cmd->scsi_sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2377 	return -EINVAL;
2378 queue_full:
2379 	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2380 	cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2381 	transport_handle_queue_full(cmd, cmd->se_dev);
2382 	return 0;
2383 }
2384 EXPORT_SYMBOL(transport_generic_new_cmd);
2385 
2386 static void transport_write_pending_qf(struct se_cmd *cmd)
2387 {
2388 	int ret;
2389 
2390 	ret = cmd->se_tfo->write_pending(cmd);
2391 	if (ret == -EAGAIN || ret == -ENOMEM) {
2392 		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2393 			 cmd);
2394 		transport_handle_queue_full(cmd, cmd->se_dev);
2395 	}
2396 }
2397 
2398 void transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2399 {
2400 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2401 		if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2402 			 transport_wait_for_tasks(cmd);
2403 
2404 		transport_release_cmd(cmd);
2405 	} else {
2406 		if (wait_for_tasks)
2407 			transport_wait_for_tasks(cmd);
2408 
2409 		core_dec_lacl_count(cmd->se_sess->se_node_acl, cmd);
2410 
2411 		if (cmd->se_lun)
2412 			transport_lun_remove_cmd(cmd);
2413 
2414 		transport_put_cmd(cmd);
2415 	}
2416 }
2417 EXPORT_SYMBOL(transport_generic_free_cmd);
2418 
2419 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2420  * @se_sess:	session to reference
2421  * @se_cmd:	command descriptor to add
2422  * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
2423  */
2424 static int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
2425 			       bool ack_kref)
2426 {
2427 	unsigned long flags;
2428 	int ret = 0;
2429 
2430 	kref_init(&se_cmd->cmd_kref);
2431 	/*
2432 	 * Add a second kref if the fabric caller is expecting to handle
2433 	 * fabric acknowledgement that requires two target_put_sess_cmd()
2434 	 * invocations before se_cmd descriptor release.
2435 	 */
2436 	if (ack_kref == true) {
2437 		kref_get(&se_cmd->cmd_kref);
2438 		se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2439 	}
2440 
2441 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2442 	if (se_sess->sess_tearing_down) {
2443 		ret = -ESHUTDOWN;
2444 		goto out;
2445 	}
2446 	list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2447 	se_cmd->check_release = 1;
2448 
2449 out:
2450 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2451 	return ret;
2452 }
2453 
2454 static void target_release_cmd_kref(struct kref *kref)
2455 {
2456 	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2457 	struct se_session *se_sess = se_cmd->se_sess;
2458 	unsigned long flags;
2459 
2460 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2461 	if (list_empty(&se_cmd->se_cmd_list)) {
2462 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2463 		se_cmd->se_tfo->release_cmd(se_cmd);
2464 		return;
2465 	}
2466 	if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2467 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2468 		complete(&se_cmd->cmd_wait_comp);
2469 		return;
2470 	}
2471 	list_del(&se_cmd->se_cmd_list);
2472 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2473 
2474 	se_cmd->se_tfo->release_cmd(se_cmd);
2475 }
2476 
2477 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2478  * @se_sess:	session to reference
2479  * @se_cmd:	command descriptor to drop
2480  */
2481 int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd)
2482 {
2483 	return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2484 }
2485 EXPORT_SYMBOL(target_put_sess_cmd);
2486 
2487 /* target_sess_cmd_list_set_waiting - Flag all commands in
2488  *         sess_cmd_list to complete cmd_wait_comp.  Set
2489  *         sess_tearing_down so no more commands are queued.
2490  * @se_sess:	session to flag
2491  */
2492 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2493 {
2494 	struct se_cmd *se_cmd;
2495 	unsigned long flags;
2496 
2497 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2498 
2499 	WARN_ON(se_sess->sess_tearing_down);
2500 	se_sess->sess_tearing_down = 1;
2501 
2502 	list_for_each_entry(se_cmd, &se_sess->sess_cmd_list, se_cmd_list)
2503 		se_cmd->cmd_wait_set = 1;
2504 
2505 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2506 }
2507 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2508 
2509 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2510  * @se_sess:    session to wait for active I/O
2511  * @wait_for_tasks:	Make extra transport_wait_for_tasks call
2512  */
2513 void target_wait_for_sess_cmds(
2514 	struct se_session *se_sess,
2515 	int wait_for_tasks)
2516 {
2517 	struct se_cmd *se_cmd, *tmp_cmd;
2518 	bool rc = false;
2519 
2520 	list_for_each_entry_safe(se_cmd, tmp_cmd,
2521 				&se_sess->sess_cmd_list, se_cmd_list) {
2522 		list_del(&se_cmd->se_cmd_list);
2523 
2524 		pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2525 			" %d\n", se_cmd, se_cmd->t_state,
2526 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2527 
2528 		if (wait_for_tasks) {
2529 			pr_debug("Calling transport_wait_for_tasks se_cmd: %p t_state: %d,"
2530 				" fabric state: %d\n", se_cmd, se_cmd->t_state,
2531 				se_cmd->se_tfo->get_cmd_state(se_cmd));
2532 
2533 			rc = transport_wait_for_tasks(se_cmd);
2534 
2535 			pr_debug("After transport_wait_for_tasks se_cmd: %p t_state: %d,"
2536 				" fabric state: %d\n", se_cmd, se_cmd->t_state,
2537 				se_cmd->se_tfo->get_cmd_state(se_cmd));
2538 		}
2539 
2540 		if (!rc) {
2541 			wait_for_completion(&se_cmd->cmd_wait_comp);
2542 			pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2543 				" fabric state: %d\n", se_cmd, se_cmd->t_state,
2544 				se_cmd->se_tfo->get_cmd_state(se_cmd));
2545 		}
2546 
2547 		se_cmd->se_tfo->release_cmd(se_cmd);
2548 	}
2549 }
2550 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2551 
2552 /*	transport_lun_wait_for_tasks():
2553  *
2554  *	Called from ConfigFS context to stop the passed struct se_cmd to allow
2555  *	an struct se_lun to be successfully shutdown.
2556  */
2557 static int transport_lun_wait_for_tasks(struct se_cmd *cmd, struct se_lun *lun)
2558 {
2559 	unsigned long flags;
2560 	int ret = 0;
2561 
2562 	/*
2563 	 * If the frontend has already requested this struct se_cmd to
2564 	 * be stopped, we can safely ignore this struct se_cmd.
2565 	 */
2566 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2567 	if (cmd->transport_state & CMD_T_STOP) {
2568 		cmd->transport_state &= ~CMD_T_LUN_STOP;
2569 
2570 		pr_debug("ConfigFS ITT[0x%08x] - CMD_T_STOP, skipping\n",
2571 			 cmd->se_tfo->get_task_tag(cmd));
2572 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2573 		transport_cmd_check_stop(cmd, false);
2574 		return -EPERM;
2575 	}
2576 	cmd->transport_state |= CMD_T_LUN_FE_STOP;
2577 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2578 
2579 	// XXX: audit task_flags checks.
2580 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2581 	if ((cmd->transport_state & CMD_T_BUSY) &&
2582 	    (cmd->transport_state & CMD_T_SENT)) {
2583 		if (!target_stop_cmd(cmd, &flags))
2584 			ret++;
2585 	}
2586 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2587 
2588 	pr_debug("ConfigFS: cmd: %p stop tasks ret:"
2589 			" %d\n", cmd, ret);
2590 	if (!ret) {
2591 		pr_debug("ConfigFS: ITT[0x%08x] - stopping cmd....\n",
2592 				cmd->se_tfo->get_task_tag(cmd));
2593 		wait_for_completion(&cmd->transport_lun_stop_comp);
2594 		pr_debug("ConfigFS: ITT[0x%08x] - stopped cmd....\n",
2595 				cmd->se_tfo->get_task_tag(cmd));
2596 	}
2597 
2598 	return 0;
2599 }
2600 
2601 static void __transport_clear_lun_from_sessions(struct se_lun *lun)
2602 {
2603 	struct se_cmd *cmd = NULL;
2604 	unsigned long lun_flags, cmd_flags;
2605 	/*
2606 	 * Do exception processing and return CHECK_CONDITION status to the
2607 	 * Initiator Port.
2608 	 */
2609 	spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2610 	while (!list_empty(&lun->lun_cmd_list)) {
2611 		cmd = list_first_entry(&lun->lun_cmd_list,
2612 		       struct se_cmd, se_lun_node);
2613 		list_del_init(&cmd->se_lun_node);
2614 
2615 		spin_lock(&cmd->t_state_lock);
2616 		pr_debug("SE_LUN[%d] - Setting cmd->transport"
2617 			"_lun_stop for  ITT: 0x%08x\n",
2618 			cmd->se_lun->unpacked_lun,
2619 			cmd->se_tfo->get_task_tag(cmd));
2620 		cmd->transport_state |= CMD_T_LUN_STOP;
2621 		spin_unlock(&cmd->t_state_lock);
2622 
2623 		spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
2624 
2625 		if (!cmd->se_lun) {
2626 			pr_err("ITT: 0x%08x, [i,t]_state: %u/%u\n",
2627 				cmd->se_tfo->get_task_tag(cmd),
2628 				cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2629 			BUG();
2630 		}
2631 		/*
2632 		 * If the Storage engine still owns the iscsi_cmd_t, determine
2633 		 * and/or stop its context.
2634 		 */
2635 		pr_debug("SE_LUN[%d] - ITT: 0x%08x before transport"
2636 			"_lun_wait_for_tasks()\n", cmd->se_lun->unpacked_lun,
2637 			cmd->se_tfo->get_task_tag(cmd));
2638 
2639 		if (transport_lun_wait_for_tasks(cmd, cmd->se_lun) < 0) {
2640 			spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2641 			continue;
2642 		}
2643 
2644 		pr_debug("SE_LUN[%d] - ITT: 0x%08x after transport_lun"
2645 			"_wait_for_tasks(): SUCCESS\n",
2646 			cmd->se_lun->unpacked_lun,
2647 			cmd->se_tfo->get_task_tag(cmd));
2648 
2649 		spin_lock_irqsave(&cmd->t_state_lock, cmd_flags);
2650 		if (!(cmd->transport_state & CMD_T_DEV_ACTIVE)) {
2651 			spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2652 			goto check_cond;
2653 		}
2654 		cmd->transport_state &= ~CMD_T_DEV_ACTIVE;
2655 		target_remove_from_state_list(cmd);
2656 		spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2657 
2658 		/*
2659 		 * The Storage engine stopped this struct se_cmd before it was
2660 		 * send to the fabric frontend for delivery back to the
2661 		 * Initiator Node.  Return this SCSI CDB back with an
2662 		 * CHECK_CONDITION status.
2663 		 */
2664 check_cond:
2665 		transport_send_check_condition_and_sense(cmd,
2666 				TCM_NON_EXISTENT_LUN, 0);
2667 		/*
2668 		 *  If the fabric frontend is waiting for this iscsi_cmd_t to
2669 		 * be released, notify the waiting thread now that LU has
2670 		 * finished accessing it.
2671 		 */
2672 		spin_lock_irqsave(&cmd->t_state_lock, cmd_flags);
2673 		if (cmd->transport_state & CMD_T_LUN_FE_STOP) {
2674 			pr_debug("SE_LUN[%d] - Detected FE stop for"
2675 				" struct se_cmd: %p ITT: 0x%08x\n",
2676 				lun->unpacked_lun,
2677 				cmd, cmd->se_tfo->get_task_tag(cmd));
2678 
2679 			spin_unlock_irqrestore(&cmd->t_state_lock,
2680 					cmd_flags);
2681 			transport_cmd_check_stop(cmd, false);
2682 			complete(&cmd->transport_lun_fe_stop_comp);
2683 			spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2684 			continue;
2685 		}
2686 		pr_debug("SE_LUN[%d] - ITT: 0x%08x finished processing\n",
2687 			lun->unpacked_lun, cmd->se_tfo->get_task_tag(cmd));
2688 
2689 		spin_unlock_irqrestore(&cmd->t_state_lock, cmd_flags);
2690 		spin_lock_irqsave(&lun->lun_cmd_lock, lun_flags);
2691 	}
2692 	spin_unlock_irqrestore(&lun->lun_cmd_lock, lun_flags);
2693 }
2694 
2695 static int transport_clear_lun_thread(void *p)
2696 {
2697 	struct se_lun *lun = p;
2698 
2699 	__transport_clear_lun_from_sessions(lun);
2700 	complete(&lun->lun_shutdown_comp);
2701 
2702 	return 0;
2703 }
2704 
2705 int transport_clear_lun_from_sessions(struct se_lun *lun)
2706 {
2707 	struct task_struct *kt;
2708 
2709 	kt = kthread_run(transport_clear_lun_thread, lun,
2710 			"tcm_cl_%u", lun->unpacked_lun);
2711 	if (IS_ERR(kt)) {
2712 		pr_err("Unable to start clear_lun thread\n");
2713 		return PTR_ERR(kt);
2714 	}
2715 	wait_for_completion(&lun->lun_shutdown_comp);
2716 
2717 	return 0;
2718 }
2719 
2720 /**
2721  * transport_wait_for_tasks - wait for completion to occur
2722  * @cmd:	command to wait
2723  *
2724  * Called from frontend fabric context to wait for storage engine
2725  * to pause and/or release frontend generated struct se_cmd.
2726  */
2727 bool transport_wait_for_tasks(struct se_cmd *cmd)
2728 {
2729 	unsigned long flags;
2730 
2731 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2732 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2733 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2734 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2735 		return false;
2736 	}
2737 
2738 	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2739 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2740 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2741 		return false;
2742 	}
2743 	/*
2744 	 * If we are already stopped due to an external event (ie: LUN shutdown)
2745 	 * sleep until the connection can have the passed struct se_cmd back.
2746 	 * The cmd->transport_lun_stopped_sem will be upped by
2747 	 * transport_clear_lun_from_sessions() once the ConfigFS context caller
2748 	 * has completed its operation on the struct se_cmd.
2749 	 */
2750 	if (cmd->transport_state & CMD_T_LUN_STOP) {
2751 		pr_debug("wait_for_tasks: Stopping"
2752 			" wait_for_completion(&cmd->t_tasktransport_lun_fe"
2753 			"_stop_comp); for ITT: 0x%08x\n",
2754 			cmd->se_tfo->get_task_tag(cmd));
2755 		/*
2756 		 * There is a special case for WRITES where a FE exception +
2757 		 * LUN shutdown means ConfigFS context is still sleeping on
2758 		 * transport_lun_stop_comp in transport_lun_wait_for_tasks().
2759 		 * We go ahead and up transport_lun_stop_comp just to be sure
2760 		 * here.
2761 		 */
2762 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2763 		complete(&cmd->transport_lun_stop_comp);
2764 		wait_for_completion(&cmd->transport_lun_fe_stop_comp);
2765 		spin_lock_irqsave(&cmd->t_state_lock, flags);
2766 
2767 		target_remove_from_state_list(cmd);
2768 		/*
2769 		 * At this point, the frontend who was the originator of this
2770 		 * struct se_cmd, now owns the structure and can be released through
2771 		 * normal means below.
2772 		 */
2773 		pr_debug("wait_for_tasks: Stopped"
2774 			" wait_for_completion(&cmd->t_tasktransport_lun_fe_"
2775 			"stop_comp); for ITT: 0x%08x\n",
2776 			cmd->se_tfo->get_task_tag(cmd));
2777 
2778 		cmd->transport_state &= ~CMD_T_LUN_STOP;
2779 	}
2780 
2781 	if (!(cmd->transport_state & CMD_T_ACTIVE)) {
2782 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2783 		return false;
2784 	}
2785 
2786 	cmd->transport_state |= CMD_T_STOP;
2787 
2788 	pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
2789 		" i_state: %d, t_state: %d, CMD_T_STOP\n",
2790 		cmd, cmd->se_tfo->get_task_tag(cmd),
2791 		cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2792 
2793 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2794 
2795 	wait_for_completion(&cmd->t_transport_stop_comp);
2796 
2797 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2798 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2799 
2800 	pr_debug("wait_for_tasks: Stopped wait_for_compltion("
2801 		"&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
2802 		cmd->se_tfo->get_task_tag(cmd));
2803 
2804 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2805 
2806 	return true;
2807 }
2808 EXPORT_SYMBOL(transport_wait_for_tasks);
2809 
2810 static int transport_get_sense_codes(
2811 	struct se_cmd *cmd,
2812 	u8 *asc,
2813 	u8 *ascq)
2814 {
2815 	*asc = cmd->scsi_asc;
2816 	*ascq = cmd->scsi_ascq;
2817 
2818 	return 0;
2819 }
2820 
2821 static int transport_set_sense_codes(
2822 	struct se_cmd *cmd,
2823 	u8 asc,
2824 	u8 ascq)
2825 {
2826 	cmd->scsi_asc = asc;
2827 	cmd->scsi_ascq = ascq;
2828 
2829 	return 0;
2830 }
2831 
2832 int transport_send_check_condition_and_sense(
2833 	struct se_cmd *cmd,
2834 	u8 reason,
2835 	int from_transport)
2836 {
2837 	unsigned char *buffer = cmd->sense_buffer;
2838 	unsigned long flags;
2839 	int offset;
2840 	u8 asc = 0, ascq = 0;
2841 
2842 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2843 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2844 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2845 		return 0;
2846 	}
2847 	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2848 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2849 
2850 	if (!reason && from_transport)
2851 		goto after_reason;
2852 
2853 	if (!from_transport)
2854 		cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2855 	/*
2856 	 * Data Segment and SenseLength of the fabric response PDU.
2857 	 *
2858 	 * TRANSPORT_SENSE_BUFFER is now set to SCSI_SENSE_BUFFERSIZE
2859 	 * from include/scsi/scsi_cmnd.h
2860 	 */
2861 	offset = cmd->se_tfo->set_fabric_sense_len(cmd,
2862 				TRANSPORT_SENSE_BUFFER);
2863 	/*
2864 	 * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
2865 	 * SENSE KEY values from include/scsi/scsi.h
2866 	 */
2867 	switch (reason) {
2868 	case TCM_NON_EXISTENT_LUN:
2869 		/* CURRENT ERROR */
2870 		buffer[offset] = 0x70;
2871 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2872 		/* ILLEGAL REQUEST */
2873 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2874 		/* LOGICAL UNIT NOT SUPPORTED */
2875 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x25;
2876 		break;
2877 	case TCM_UNSUPPORTED_SCSI_OPCODE:
2878 	case TCM_SECTOR_COUNT_TOO_MANY:
2879 		/* CURRENT ERROR */
2880 		buffer[offset] = 0x70;
2881 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2882 		/* ILLEGAL REQUEST */
2883 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2884 		/* INVALID COMMAND OPERATION CODE */
2885 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x20;
2886 		break;
2887 	case TCM_UNKNOWN_MODE_PAGE:
2888 		/* CURRENT ERROR */
2889 		buffer[offset] = 0x70;
2890 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2891 		/* ILLEGAL REQUEST */
2892 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2893 		/* INVALID FIELD IN CDB */
2894 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x24;
2895 		break;
2896 	case TCM_CHECK_CONDITION_ABORT_CMD:
2897 		/* CURRENT ERROR */
2898 		buffer[offset] = 0x70;
2899 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2900 		/* ABORTED COMMAND */
2901 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2902 		/* BUS DEVICE RESET FUNCTION OCCURRED */
2903 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x29;
2904 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = 0x03;
2905 		break;
2906 	case TCM_INCORRECT_AMOUNT_OF_DATA:
2907 		/* CURRENT ERROR */
2908 		buffer[offset] = 0x70;
2909 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2910 		/* ABORTED COMMAND */
2911 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2912 		/* WRITE ERROR */
2913 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x0c;
2914 		/* NOT ENOUGH UNSOLICITED DATA */
2915 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = 0x0d;
2916 		break;
2917 	case TCM_INVALID_CDB_FIELD:
2918 		/* CURRENT ERROR */
2919 		buffer[offset] = 0x70;
2920 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2921 		/* ILLEGAL REQUEST */
2922 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2923 		/* INVALID FIELD IN CDB */
2924 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x24;
2925 		break;
2926 	case TCM_INVALID_PARAMETER_LIST:
2927 		/* CURRENT ERROR */
2928 		buffer[offset] = 0x70;
2929 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2930 		/* ILLEGAL REQUEST */
2931 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2932 		/* INVALID FIELD IN PARAMETER LIST */
2933 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x26;
2934 		break;
2935 	case TCM_UNEXPECTED_UNSOLICITED_DATA:
2936 		/* CURRENT ERROR */
2937 		buffer[offset] = 0x70;
2938 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2939 		/* ABORTED COMMAND */
2940 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2941 		/* WRITE ERROR */
2942 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x0c;
2943 		/* UNEXPECTED_UNSOLICITED_DATA */
2944 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = 0x0c;
2945 		break;
2946 	case TCM_SERVICE_CRC_ERROR:
2947 		/* CURRENT ERROR */
2948 		buffer[offset] = 0x70;
2949 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2950 		/* ABORTED COMMAND */
2951 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2952 		/* PROTOCOL SERVICE CRC ERROR */
2953 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x47;
2954 		/* N/A */
2955 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = 0x05;
2956 		break;
2957 	case TCM_SNACK_REJECTED:
2958 		/* CURRENT ERROR */
2959 		buffer[offset] = 0x70;
2960 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2961 		/* ABORTED COMMAND */
2962 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2963 		/* READ ERROR */
2964 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x11;
2965 		/* FAILED RETRANSMISSION REQUEST */
2966 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = 0x13;
2967 		break;
2968 	case TCM_WRITE_PROTECTED:
2969 		/* CURRENT ERROR */
2970 		buffer[offset] = 0x70;
2971 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2972 		/* DATA PROTECT */
2973 		buffer[offset+SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
2974 		/* WRITE PROTECTED */
2975 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x27;
2976 		break;
2977 	case TCM_ADDRESS_OUT_OF_RANGE:
2978 		/* CURRENT ERROR */
2979 		buffer[offset] = 0x70;
2980 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2981 		/* ILLEGAL REQUEST */
2982 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2983 		/* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2984 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x21;
2985 		break;
2986 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2987 		/* CURRENT ERROR */
2988 		buffer[offset] = 0x70;
2989 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
2990 		/* UNIT ATTENTION */
2991 		buffer[offset+SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
2992 		core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2993 		buffer[offset+SPC_ASC_KEY_OFFSET] = asc;
2994 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = ascq;
2995 		break;
2996 	case TCM_CHECK_CONDITION_NOT_READY:
2997 		/* CURRENT ERROR */
2998 		buffer[offset] = 0x70;
2999 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
3000 		/* Not Ready */
3001 		buffer[offset+SPC_SENSE_KEY_OFFSET] = NOT_READY;
3002 		transport_get_sense_codes(cmd, &asc, &ascq);
3003 		buffer[offset+SPC_ASC_KEY_OFFSET] = asc;
3004 		buffer[offset+SPC_ASCQ_KEY_OFFSET] = ascq;
3005 		break;
3006 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
3007 	default:
3008 		/* CURRENT ERROR */
3009 		buffer[offset] = 0x70;
3010 		buffer[offset+SPC_ADD_SENSE_LEN_OFFSET] = 10;
3011 		/* ILLEGAL REQUEST */
3012 		buffer[offset+SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
3013 		/* LOGICAL UNIT COMMUNICATION FAILURE */
3014 		buffer[offset+SPC_ASC_KEY_OFFSET] = 0x80;
3015 		break;
3016 	}
3017 	/*
3018 	 * This code uses linux/include/scsi/scsi.h SAM status codes!
3019 	 */
3020 	cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
3021 	/*
3022 	 * Automatically padded, this value is encoded in the fabric's
3023 	 * data_length response PDU containing the SCSI defined sense data.
3024 	 */
3025 	cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER + offset;
3026 
3027 after_reason:
3028 	return cmd->se_tfo->queue_status(cmd);
3029 }
3030 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3031 
3032 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3033 {
3034 	int ret = 0;
3035 
3036 	if (cmd->transport_state & CMD_T_ABORTED) {
3037 		if (!send_status ||
3038 		     (cmd->se_cmd_flags & SCF_SENT_DELAYED_TAS))
3039 			return 1;
3040 
3041 		pr_debug("Sending delayed SAM_STAT_TASK_ABORTED"
3042 			" status for CDB: 0x%02x ITT: 0x%08x\n",
3043 			cmd->t_task_cdb[0],
3044 			cmd->se_tfo->get_task_tag(cmd));
3045 
3046 		cmd->se_cmd_flags |= SCF_SENT_DELAYED_TAS;
3047 		cmd->se_tfo->queue_status(cmd);
3048 		ret = 1;
3049 	}
3050 	return ret;
3051 }
3052 EXPORT_SYMBOL(transport_check_aborted_status);
3053 
3054 void transport_send_task_abort(struct se_cmd *cmd)
3055 {
3056 	unsigned long flags;
3057 
3058 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3059 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
3060 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3061 		return;
3062 	}
3063 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3064 
3065 	/*
3066 	 * If there are still expected incoming fabric WRITEs, we wait
3067 	 * until until they have completed before sending a TASK_ABORTED
3068 	 * response.  This response with TASK_ABORTED status will be
3069 	 * queued back to fabric module by transport_check_aborted_status().
3070 	 */
3071 	if (cmd->data_direction == DMA_TO_DEVICE) {
3072 		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3073 			cmd->transport_state |= CMD_T_ABORTED;
3074 			smp_mb__after_atomic_inc();
3075 		}
3076 	}
3077 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3078 
3079 	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
3080 		" ITT: 0x%08x\n", cmd->t_task_cdb[0],
3081 		cmd->se_tfo->get_task_tag(cmd));
3082 
3083 	cmd->se_tfo->queue_status(cmd);
3084 }
3085 
3086 static void target_tmr_work(struct work_struct *work)
3087 {
3088 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3089 	struct se_device *dev = cmd->se_dev;
3090 	struct se_tmr_req *tmr = cmd->se_tmr_req;
3091 	int ret;
3092 
3093 	switch (tmr->function) {
3094 	case TMR_ABORT_TASK:
3095 		core_tmr_abort_task(dev, tmr, cmd->se_sess);
3096 		break;
3097 	case TMR_ABORT_TASK_SET:
3098 	case TMR_CLEAR_ACA:
3099 	case TMR_CLEAR_TASK_SET:
3100 		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3101 		break;
3102 	case TMR_LUN_RESET:
3103 		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3104 		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3105 					 TMR_FUNCTION_REJECTED;
3106 		break;
3107 	case TMR_TARGET_WARM_RESET:
3108 		tmr->response = TMR_FUNCTION_REJECTED;
3109 		break;
3110 	case TMR_TARGET_COLD_RESET:
3111 		tmr->response = TMR_FUNCTION_REJECTED;
3112 		break;
3113 	default:
3114 		pr_err("Uknown TMR function: 0x%02x.\n",
3115 				tmr->function);
3116 		tmr->response = TMR_FUNCTION_REJECTED;
3117 		break;
3118 	}
3119 
3120 	cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3121 	cmd->se_tfo->queue_tm_rsp(cmd);
3122 
3123 	transport_cmd_check_stop_to_fabric(cmd);
3124 }
3125 
3126 int transport_generic_handle_tmr(
3127 	struct se_cmd *cmd)
3128 {
3129 	INIT_WORK(&cmd->work, target_tmr_work);
3130 	queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3131 	return 0;
3132 }
3133 EXPORT_SYMBOL(transport_generic_handle_tmr);
3134