1 /*******************************************************************************
2  * Filename:  target_core_transport.c
3  *
4  * This file contains the Generic Target Engine Core.
5  *
6  * (c) Copyright 2002-2013 Datera, Inc.
7  *
8  * Nicholas A. Bellinger <nab@kernel.org>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23  *
24  ******************************************************************************/
25 
26 #include <linux/net.h>
27 #include <linux/delay.h>
28 #include <linux/string.h>
29 #include <linux/timer.h>
30 #include <linux/slab.h>
31 #include <linux/spinlock.h>
32 #include <linux/kthread.h>
33 #include <linux/in.h>
34 #include <linux/cdrom.h>
35 #include <linux/module.h>
36 #include <linux/ratelimit.h>
37 #include <linux/vmalloc.h>
38 #include <asm/unaligned.h>
39 #include <net/sock.h>
40 #include <net/tcp.h>
41 #include <scsi/scsi_proto.h>
42 #include <scsi/scsi_common.h>
43 
44 #include <target/target_core_base.h>
45 #include <target/target_core_backend.h>
46 #include <target/target_core_fabric.h>
47 
48 #include "target_core_internal.h"
49 #include "target_core_alua.h"
50 #include "target_core_pr.h"
51 #include "target_core_ua.h"
52 
53 #define CREATE_TRACE_POINTS
54 #include <trace/events/target.h>
55 
56 static struct workqueue_struct *target_completion_wq;
57 static struct kmem_cache *se_sess_cache;
58 struct kmem_cache *se_ua_cache;
59 struct kmem_cache *t10_pr_reg_cache;
60 struct kmem_cache *t10_alua_lu_gp_cache;
61 struct kmem_cache *t10_alua_lu_gp_mem_cache;
62 struct kmem_cache *t10_alua_tg_pt_gp_cache;
63 struct kmem_cache *t10_alua_lba_map_cache;
64 struct kmem_cache *t10_alua_lba_map_mem_cache;
65 
66 static void transport_complete_task_attr(struct se_cmd *cmd);
67 static void transport_handle_queue_full(struct se_cmd *cmd,
68 		struct se_device *dev);
69 static int transport_put_cmd(struct se_cmd *cmd);
70 static void target_complete_ok_work(struct work_struct *work);
71 
72 int init_se_kmem_caches(void)
73 {
74 	se_sess_cache = kmem_cache_create("se_sess_cache",
75 			sizeof(struct se_session), __alignof__(struct se_session),
76 			0, NULL);
77 	if (!se_sess_cache) {
78 		pr_err("kmem_cache_create() for struct se_session"
79 				" failed\n");
80 		goto out;
81 	}
82 	se_ua_cache = kmem_cache_create("se_ua_cache",
83 			sizeof(struct se_ua), __alignof__(struct se_ua),
84 			0, NULL);
85 	if (!se_ua_cache) {
86 		pr_err("kmem_cache_create() for struct se_ua failed\n");
87 		goto out_free_sess_cache;
88 	}
89 	t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
90 			sizeof(struct t10_pr_registration),
91 			__alignof__(struct t10_pr_registration), 0, NULL);
92 	if (!t10_pr_reg_cache) {
93 		pr_err("kmem_cache_create() for struct t10_pr_registration"
94 				" failed\n");
95 		goto out_free_ua_cache;
96 	}
97 	t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
98 			sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
99 			0, NULL);
100 	if (!t10_alua_lu_gp_cache) {
101 		pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
102 				" failed\n");
103 		goto out_free_pr_reg_cache;
104 	}
105 	t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
106 			sizeof(struct t10_alua_lu_gp_member),
107 			__alignof__(struct t10_alua_lu_gp_member), 0, NULL);
108 	if (!t10_alua_lu_gp_mem_cache) {
109 		pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
110 				"cache failed\n");
111 		goto out_free_lu_gp_cache;
112 	}
113 	t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
114 			sizeof(struct t10_alua_tg_pt_gp),
115 			__alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
116 	if (!t10_alua_tg_pt_gp_cache) {
117 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
118 				"cache failed\n");
119 		goto out_free_lu_gp_mem_cache;
120 	}
121 	t10_alua_lba_map_cache = kmem_cache_create(
122 			"t10_alua_lba_map_cache",
123 			sizeof(struct t10_alua_lba_map),
124 			__alignof__(struct t10_alua_lba_map), 0, NULL);
125 	if (!t10_alua_lba_map_cache) {
126 		pr_err("kmem_cache_create() for t10_alua_lba_map_"
127 				"cache failed\n");
128 		goto out_free_tg_pt_gp_cache;
129 	}
130 	t10_alua_lba_map_mem_cache = kmem_cache_create(
131 			"t10_alua_lba_map_mem_cache",
132 			sizeof(struct t10_alua_lba_map_member),
133 			__alignof__(struct t10_alua_lba_map_member), 0, NULL);
134 	if (!t10_alua_lba_map_mem_cache) {
135 		pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
136 				"cache failed\n");
137 		goto out_free_lba_map_cache;
138 	}
139 
140 	target_completion_wq = alloc_workqueue("target_completion",
141 					       WQ_MEM_RECLAIM, 0);
142 	if (!target_completion_wq)
143 		goto out_free_lba_map_mem_cache;
144 
145 	return 0;
146 
147 out_free_lba_map_mem_cache:
148 	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
149 out_free_lba_map_cache:
150 	kmem_cache_destroy(t10_alua_lba_map_cache);
151 out_free_tg_pt_gp_cache:
152 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
153 out_free_lu_gp_mem_cache:
154 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
155 out_free_lu_gp_cache:
156 	kmem_cache_destroy(t10_alua_lu_gp_cache);
157 out_free_pr_reg_cache:
158 	kmem_cache_destroy(t10_pr_reg_cache);
159 out_free_ua_cache:
160 	kmem_cache_destroy(se_ua_cache);
161 out_free_sess_cache:
162 	kmem_cache_destroy(se_sess_cache);
163 out:
164 	return -ENOMEM;
165 }
166 
167 void release_se_kmem_caches(void)
168 {
169 	destroy_workqueue(target_completion_wq);
170 	kmem_cache_destroy(se_sess_cache);
171 	kmem_cache_destroy(se_ua_cache);
172 	kmem_cache_destroy(t10_pr_reg_cache);
173 	kmem_cache_destroy(t10_alua_lu_gp_cache);
174 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
175 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
176 	kmem_cache_destroy(t10_alua_lba_map_cache);
177 	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
178 }
179 
180 /* This code ensures unique mib indexes are handed out. */
181 static DEFINE_SPINLOCK(scsi_mib_index_lock);
182 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
183 
184 /*
185  * Allocate a new row index for the entry type specified
186  */
187 u32 scsi_get_new_index(scsi_index_t type)
188 {
189 	u32 new_index;
190 
191 	BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
192 
193 	spin_lock(&scsi_mib_index_lock);
194 	new_index = ++scsi_mib_index[type];
195 	spin_unlock(&scsi_mib_index_lock);
196 
197 	return new_index;
198 }
199 
200 void transport_subsystem_check_init(void)
201 {
202 	int ret;
203 	static int sub_api_initialized;
204 
205 	if (sub_api_initialized)
206 		return;
207 
208 	ret = request_module("target_core_iblock");
209 	if (ret != 0)
210 		pr_err("Unable to load target_core_iblock\n");
211 
212 	ret = request_module("target_core_file");
213 	if (ret != 0)
214 		pr_err("Unable to load target_core_file\n");
215 
216 	ret = request_module("target_core_pscsi");
217 	if (ret != 0)
218 		pr_err("Unable to load target_core_pscsi\n");
219 
220 	ret = request_module("target_core_user");
221 	if (ret != 0)
222 		pr_err("Unable to load target_core_user\n");
223 
224 	sub_api_initialized = 1;
225 }
226 
227 struct se_session *transport_init_session(enum target_prot_op sup_prot_ops)
228 {
229 	struct se_session *se_sess;
230 
231 	se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
232 	if (!se_sess) {
233 		pr_err("Unable to allocate struct se_session from"
234 				" se_sess_cache\n");
235 		return ERR_PTR(-ENOMEM);
236 	}
237 	INIT_LIST_HEAD(&se_sess->sess_list);
238 	INIT_LIST_HEAD(&se_sess->sess_acl_list);
239 	INIT_LIST_HEAD(&se_sess->sess_cmd_list);
240 	INIT_LIST_HEAD(&se_sess->sess_wait_list);
241 	spin_lock_init(&se_sess->sess_cmd_lock);
242 	se_sess->sup_prot_ops = sup_prot_ops;
243 
244 	return se_sess;
245 }
246 EXPORT_SYMBOL(transport_init_session);
247 
248 int transport_alloc_session_tags(struct se_session *se_sess,
249 			         unsigned int tag_num, unsigned int tag_size)
250 {
251 	int rc;
252 
253 	se_sess->sess_cmd_map = kzalloc(tag_num * tag_size,
254 					GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
255 	if (!se_sess->sess_cmd_map) {
256 		se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
257 		if (!se_sess->sess_cmd_map) {
258 			pr_err("Unable to allocate se_sess->sess_cmd_map\n");
259 			return -ENOMEM;
260 		}
261 	}
262 
263 	rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
264 	if (rc < 0) {
265 		pr_err("Unable to init se_sess->sess_tag_pool,"
266 			" tag_num: %u\n", tag_num);
267 		kvfree(se_sess->sess_cmd_map);
268 		se_sess->sess_cmd_map = NULL;
269 		return -ENOMEM;
270 	}
271 
272 	return 0;
273 }
274 EXPORT_SYMBOL(transport_alloc_session_tags);
275 
276 struct se_session *transport_init_session_tags(unsigned int tag_num,
277 					       unsigned int tag_size,
278 					       enum target_prot_op sup_prot_ops)
279 {
280 	struct se_session *se_sess;
281 	int rc;
282 
283 	if (tag_num != 0 && !tag_size) {
284 		pr_err("init_session_tags called with percpu-ida tag_num:"
285 		       " %u, but zero tag_size\n", tag_num);
286 		return ERR_PTR(-EINVAL);
287 	}
288 	if (!tag_num && tag_size) {
289 		pr_err("init_session_tags called with percpu-ida tag_size:"
290 		       " %u, but zero tag_num\n", tag_size);
291 		return ERR_PTR(-EINVAL);
292 	}
293 
294 	se_sess = transport_init_session(sup_prot_ops);
295 	if (IS_ERR(se_sess))
296 		return se_sess;
297 
298 	rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
299 	if (rc < 0) {
300 		transport_free_session(se_sess);
301 		return ERR_PTR(-ENOMEM);
302 	}
303 
304 	return se_sess;
305 }
306 EXPORT_SYMBOL(transport_init_session_tags);
307 
308 /*
309  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
310  */
311 void __transport_register_session(
312 	struct se_portal_group *se_tpg,
313 	struct se_node_acl *se_nacl,
314 	struct se_session *se_sess,
315 	void *fabric_sess_ptr)
316 {
317 	const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
318 	unsigned char buf[PR_REG_ISID_LEN];
319 
320 	se_sess->se_tpg = se_tpg;
321 	se_sess->fabric_sess_ptr = fabric_sess_ptr;
322 	/*
323 	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
324 	 *
325 	 * Only set for struct se_session's that will actually be moving I/O.
326 	 * eg: *NOT* discovery sessions.
327 	 */
328 	if (se_nacl) {
329 		/*
330 		 *
331 		 * Determine if fabric allows for T10-PI feature bits exposed to
332 		 * initiators for device backends with !dev->dev_attrib.pi_prot_type.
333 		 *
334 		 * If so, then always save prot_type on a per se_node_acl node
335 		 * basis and re-instate the previous sess_prot_type to avoid
336 		 * disabling PI from below any previously initiator side
337 		 * registered LUNs.
338 		 */
339 		if (se_nacl->saved_prot_type)
340 			se_sess->sess_prot_type = se_nacl->saved_prot_type;
341 		else if (tfo->tpg_check_prot_fabric_only)
342 			se_sess->sess_prot_type = se_nacl->saved_prot_type =
343 					tfo->tpg_check_prot_fabric_only(se_tpg);
344 		/*
345 		 * If the fabric module supports an ISID based TransportID,
346 		 * save this value in binary from the fabric I_T Nexus now.
347 		 */
348 		if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
349 			memset(&buf[0], 0, PR_REG_ISID_LEN);
350 			se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
351 					&buf[0], PR_REG_ISID_LEN);
352 			se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
353 		}
354 
355 		spin_lock_irq(&se_nacl->nacl_sess_lock);
356 		/*
357 		 * The se_nacl->nacl_sess pointer will be set to the
358 		 * last active I_T Nexus for each struct se_node_acl.
359 		 */
360 		se_nacl->nacl_sess = se_sess;
361 
362 		list_add_tail(&se_sess->sess_acl_list,
363 			      &se_nacl->acl_sess_list);
364 		spin_unlock_irq(&se_nacl->nacl_sess_lock);
365 	}
366 	list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
367 
368 	pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
369 		se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
370 }
371 EXPORT_SYMBOL(__transport_register_session);
372 
373 void transport_register_session(
374 	struct se_portal_group *se_tpg,
375 	struct se_node_acl *se_nacl,
376 	struct se_session *se_sess,
377 	void *fabric_sess_ptr)
378 {
379 	unsigned long flags;
380 
381 	spin_lock_irqsave(&se_tpg->session_lock, flags);
382 	__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
383 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
384 }
385 EXPORT_SYMBOL(transport_register_session);
386 
387 struct se_session *
388 target_alloc_session(struct se_portal_group *tpg,
389 		     unsigned int tag_num, unsigned int tag_size,
390 		     enum target_prot_op prot_op,
391 		     const char *initiatorname, void *private,
392 		     int (*callback)(struct se_portal_group *,
393 				     struct se_session *, void *))
394 {
395 	struct se_session *sess;
396 
397 	/*
398 	 * If the fabric driver is using percpu-ida based pre allocation
399 	 * of I/O descriptor tags, go ahead and perform that setup now..
400 	 */
401 	if (tag_num != 0)
402 		sess = transport_init_session_tags(tag_num, tag_size, prot_op);
403 	else
404 		sess = transport_init_session(prot_op);
405 
406 	if (IS_ERR(sess))
407 		return sess;
408 
409 	sess->se_node_acl = core_tpg_check_initiator_node_acl(tpg,
410 					(unsigned char *)initiatorname);
411 	if (!sess->se_node_acl) {
412 		transport_free_session(sess);
413 		return ERR_PTR(-EACCES);
414 	}
415 	/*
416 	 * Go ahead and perform any remaining fabric setup that is
417 	 * required before transport_register_session().
418 	 */
419 	if (callback != NULL) {
420 		int rc = callback(tpg, sess, private);
421 		if (rc) {
422 			transport_free_session(sess);
423 			return ERR_PTR(rc);
424 		}
425 	}
426 
427 	transport_register_session(tpg, sess->se_node_acl, sess, private);
428 	return sess;
429 }
430 EXPORT_SYMBOL(target_alloc_session);
431 
432 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
433 {
434 	struct se_session *se_sess;
435 	ssize_t len = 0;
436 
437 	spin_lock_bh(&se_tpg->session_lock);
438 	list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
439 		if (!se_sess->se_node_acl)
440 			continue;
441 		if (!se_sess->se_node_acl->dynamic_node_acl)
442 			continue;
443 		if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
444 			break;
445 
446 		len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
447 				se_sess->se_node_acl->initiatorname);
448 		len += 1; /* Include NULL terminator */
449 	}
450 	spin_unlock_bh(&se_tpg->session_lock);
451 
452 	return len;
453 }
454 EXPORT_SYMBOL(target_show_dynamic_sessions);
455 
456 static void target_complete_nacl(struct kref *kref)
457 {
458 	struct se_node_acl *nacl = container_of(kref,
459 				struct se_node_acl, acl_kref);
460 	struct se_portal_group *se_tpg = nacl->se_tpg;
461 
462 	if (!nacl->dynamic_stop) {
463 		complete(&nacl->acl_free_comp);
464 		return;
465 	}
466 
467 	mutex_lock(&se_tpg->acl_node_mutex);
468 	list_del(&nacl->acl_list);
469 	mutex_unlock(&se_tpg->acl_node_mutex);
470 
471 	core_tpg_wait_for_nacl_pr_ref(nacl);
472 	core_free_device_list_for_node(nacl, se_tpg);
473 	kfree(nacl);
474 }
475 
476 void target_put_nacl(struct se_node_acl *nacl)
477 {
478 	kref_put(&nacl->acl_kref, target_complete_nacl);
479 }
480 EXPORT_SYMBOL(target_put_nacl);
481 
482 void transport_deregister_session_configfs(struct se_session *se_sess)
483 {
484 	struct se_node_acl *se_nacl;
485 	unsigned long flags;
486 	/*
487 	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
488 	 */
489 	se_nacl = se_sess->se_node_acl;
490 	if (se_nacl) {
491 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
492 		if (!list_empty(&se_sess->sess_acl_list))
493 			list_del_init(&se_sess->sess_acl_list);
494 		/*
495 		 * If the session list is empty, then clear the pointer.
496 		 * Otherwise, set the struct se_session pointer from the tail
497 		 * element of the per struct se_node_acl active session list.
498 		 */
499 		if (list_empty(&se_nacl->acl_sess_list))
500 			se_nacl->nacl_sess = NULL;
501 		else {
502 			se_nacl->nacl_sess = container_of(
503 					se_nacl->acl_sess_list.prev,
504 					struct se_session, sess_acl_list);
505 		}
506 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
507 	}
508 }
509 EXPORT_SYMBOL(transport_deregister_session_configfs);
510 
511 void transport_free_session(struct se_session *se_sess)
512 {
513 	struct se_node_acl *se_nacl = se_sess->se_node_acl;
514 
515 	/*
516 	 * Drop the se_node_acl->nacl_kref obtained from within
517 	 * core_tpg_get_initiator_node_acl().
518 	 */
519 	if (se_nacl) {
520 		struct se_portal_group *se_tpg = se_nacl->se_tpg;
521 		const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo;
522 		unsigned long flags;
523 
524 		se_sess->se_node_acl = NULL;
525 
526 		/*
527 		 * Also determine if we need to drop the extra ->cmd_kref if
528 		 * it had been previously dynamically generated, and
529 		 * the endpoint is not caching dynamic ACLs.
530 		 */
531 		mutex_lock(&se_tpg->acl_node_mutex);
532 		if (se_nacl->dynamic_node_acl &&
533 		    !se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
534 			spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
535 			if (list_empty(&se_nacl->acl_sess_list))
536 				se_nacl->dynamic_stop = true;
537 			spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
538 
539 			if (se_nacl->dynamic_stop)
540 				list_del(&se_nacl->acl_list);
541 		}
542 		mutex_unlock(&se_tpg->acl_node_mutex);
543 
544 		if (se_nacl->dynamic_stop)
545 			target_put_nacl(se_nacl);
546 
547 		target_put_nacl(se_nacl);
548 	}
549 	if (se_sess->sess_cmd_map) {
550 		percpu_ida_destroy(&se_sess->sess_tag_pool);
551 		kvfree(se_sess->sess_cmd_map);
552 	}
553 	kmem_cache_free(se_sess_cache, se_sess);
554 }
555 EXPORT_SYMBOL(transport_free_session);
556 
557 void transport_deregister_session(struct se_session *se_sess)
558 {
559 	struct se_portal_group *se_tpg = se_sess->se_tpg;
560 	unsigned long flags;
561 
562 	if (!se_tpg) {
563 		transport_free_session(se_sess);
564 		return;
565 	}
566 
567 	spin_lock_irqsave(&se_tpg->session_lock, flags);
568 	list_del(&se_sess->sess_list);
569 	se_sess->se_tpg = NULL;
570 	se_sess->fabric_sess_ptr = NULL;
571 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
572 
573 	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
574 		se_tpg->se_tpg_tfo->get_fabric_name());
575 	/*
576 	 * If last kref is dropping now for an explicit NodeACL, awake sleeping
577 	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
578 	 * removal context from within transport_free_session() code.
579 	 *
580 	 * For dynamic ACL, target_put_nacl() uses target_complete_nacl()
581 	 * to release all remaining generate_node_acl=1 created ACL resources.
582 	 */
583 
584 	transport_free_session(se_sess);
585 }
586 EXPORT_SYMBOL(transport_deregister_session);
587 
588 static void target_remove_from_state_list(struct se_cmd *cmd)
589 {
590 	struct se_device *dev = cmd->se_dev;
591 	unsigned long flags;
592 
593 	if (!dev)
594 		return;
595 
596 	spin_lock_irqsave(&dev->execute_task_lock, flags);
597 	if (cmd->state_active) {
598 		list_del(&cmd->state_list);
599 		cmd->state_active = false;
600 	}
601 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
602 }
603 
604 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
605 {
606 	unsigned long flags;
607 
608 	target_remove_from_state_list(cmd);
609 
610 	/*
611 	 * Clear struct se_cmd->se_lun before the handoff to FE.
612 	 */
613 	cmd->se_lun = NULL;
614 
615 	spin_lock_irqsave(&cmd->t_state_lock, flags);
616 	/*
617 	 * Determine if frontend context caller is requesting the stopping of
618 	 * this command for frontend exceptions.
619 	 */
620 	if (cmd->transport_state & CMD_T_STOP) {
621 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
622 			__func__, __LINE__, cmd->tag);
623 
624 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
625 
626 		complete_all(&cmd->t_transport_stop_comp);
627 		return 1;
628 	}
629 	cmd->transport_state &= ~CMD_T_ACTIVE;
630 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
631 
632 	/*
633 	 * Some fabric modules like tcm_loop can release their internally
634 	 * allocated I/O reference and struct se_cmd now.
635 	 *
636 	 * Fabric modules are expected to return '1' here if the se_cmd being
637 	 * passed is released at this point, or zero if not being released.
638 	 */
639 	return cmd->se_tfo->check_stop_free(cmd);
640 }
641 
642 static void transport_lun_remove_cmd(struct se_cmd *cmd)
643 {
644 	struct se_lun *lun = cmd->se_lun;
645 
646 	if (!lun)
647 		return;
648 
649 	if (cmpxchg(&cmd->lun_ref_active, true, false))
650 		percpu_ref_put(&lun->lun_ref);
651 }
652 
653 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
654 {
655 	bool ack_kref = (cmd->se_cmd_flags & SCF_ACK_KREF);
656 
657 	if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
658 		transport_lun_remove_cmd(cmd);
659 	/*
660 	 * Allow the fabric driver to unmap any resources before
661 	 * releasing the descriptor via TFO->release_cmd()
662 	 */
663 	if (remove)
664 		cmd->se_tfo->aborted_task(cmd);
665 
666 	if (transport_cmd_check_stop_to_fabric(cmd))
667 		return;
668 	if (remove && ack_kref)
669 		transport_put_cmd(cmd);
670 }
671 
672 static void target_complete_failure_work(struct work_struct *work)
673 {
674 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
675 
676 	transport_generic_request_failure(cmd,
677 			TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
678 }
679 
680 /*
681  * Used when asking transport to copy Sense Data from the underlying
682  * Linux/SCSI struct scsi_cmnd
683  */
684 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
685 {
686 	struct se_device *dev = cmd->se_dev;
687 
688 	WARN_ON(!cmd->se_lun);
689 
690 	if (!dev)
691 		return NULL;
692 
693 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
694 		return NULL;
695 
696 	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
697 
698 	pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
699 		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
700 	return cmd->sense_buffer;
701 }
702 
703 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
704 {
705 	struct se_device *dev = cmd->se_dev;
706 	int success = scsi_status == GOOD;
707 	unsigned long flags;
708 
709 	cmd->scsi_status = scsi_status;
710 
711 
712 	spin_lock_irqsave(&cmd->t_state_lock, flags);
713 
714 	if (dev && dev->transport->transport_complete) {
715 		dev->transport->transport_complete(cmd,
716 				cmd->t_data_sg,
717 				transport_get_sense_buffer(cmd));
718 		if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
719 			success = 1;
720 	}
721 
722 	/*
723 	 * Check for case where an explicit ABORT_TASK has been received
724 	 * and transport_wait_for_tasks() will be waiting for completion..
725 	 */
726 	if (cmd->transport_state & CMD_T_ABORTED ||
727 	    cmd->transport_state & CMD_T_STOP) {
728 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
729 		complete_all(&cmd->t_transport_stop_comp);
730 		return;
731 	} else if (!success) {
732 		INIT_WORK(&cmd->work, target_complete_failure_work);
733 	} else {
734 		INIT_WORK(&cmd->work, target_complete_ok_work);
735 	}
736 
737 	cmd->t_state = TRANSPORT_COMPLETE;
738 	cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
739 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
740 
741 	if (cmd->se_cmd_flags & SCF_USE_CPUID)
742 		queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
743 	else
744 		queue_work(target_completion_wq, &cmd->work);
745 }
746 EXPORT_SYMBOL(target_complete_cmd);
747 
748 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
749 {
750 	if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
751 		if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
752 			cmd->residual_count += cmd->data_length - length;
753 		} else {
754 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
755 			cmd->residual_count = cmd->data_length - length;
756 		}
757 
758 		cmd->data_length = length;
759 	}
760 
761 	target_complete_cmd(cmd, scsi_status);
762 }
763 EXPORT_SYMBOL(target_complete_cmd_with_length);
764 
765 static void target_add_to_state_list(struct se_cmd *cmd)
766 {
767 	struct se_device *dev = cmd->se_dev;
768 	unsigned long flags;
769 
770 	spin_lock_irqsave(&dev->execute_task_lock, flags);
771 	if (!cmd->state_active) {
772 		list_add_tail(&cmd->state_list, &dev->state_list);
773 		cmd->state_active = true;
774 	}
775 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
776 }
777 
778 /*
779  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
780  */
781 static void transport_write_pending_qf(struct se_cmd *cmd);
782 static void transport_complete_qf(struct se_cmd *cmd);
783 
784 void target_qf_do_work(struct work_struct *work)
785 {
786 	struct se_device *dev = container_of(work, struct se_device,
787 					qf_work_queue);
788 	LIST_HEAD(qf_cmd_list);
789 	struct se_cmd *cmd, *cmd_tmp;
790 
791 	spin_lock_irq(&dev->qf_cmd_lock);
792 	list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
793 	spin_unlock_irq(&dev->qf_cmd_lock);
794 
795 	list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
796 		list_del(&cmd->se_qf_node);
797 		atomic_dec_mb(&dev->dev_qf_count);
798 
799 		pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
800 			" context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
801 			(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
802 			(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
803 			: "UNKNOWN");
804 
805 		if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
806 			transport_write_pending_qf(cmd);
807 		else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
808 			transport_complete_qf(cmd);
809 	}
810 }
811 
812 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
813 {
814 	switch (cmd->data_direction) {
815 	case DMA_NONE:
816 		return "NONE";
817 	case DMA_FROM_DEVICE:
818 		return "READ";
819 	case DMA_TO_DEVICE:
820 		return "WRITE";
821 	case DMA_BIDIRECTIONAL:
822 		return "BIDI";
823 	default:
824 		break;
825 	}
826 
827 	return "UNKNOWN";
828 }
829 
830 void transport_dump_dev_state(
831 	struct se_device *dev,
832 	char *b,
833 	int *bl)
834 {
835 	*bl += sprintf(b + *bl, "Status: ");
836 	if (dev->export_count)
837 		*bl += sprintf(b + *bl, "ACTIVATED");
838 	else
839 		*bl += sprintf(b + *bl, "DEACTIVATED");
840 
841 	*bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
842 	*bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
843 		dev->dev_attrib.block_size,
844 		dev->dev_attrib.hw_max_sectors);
845 	*bl += sprintf(b + *bl, "        ");
846 }
847 
848 void transport_dump_vpd_proto_id(
849 	struct t10_vpd *vpd,
850 	unsigned char *p_buf,
851 	int p_buf_len)
852 {
853 	unsigned char buf[VPD_TMP_BUF_SIZE];
854 	int len;
855 
856 	memset(buf, 0, VPD_TMP_BUF_SIZE);
857 	len = sprintf(buf, "T10 VPD Protocol Identifier: ");
858 
859 	switch (vpd->protocol_identifier) {
860 	case 0x00:
861 		sprintf(buf+len, "Fibre Channel\n");
862 		break;
863 	case 0x10:
864 		sprintf(buf+len, "Parallel SCSI\n");
865 		break;
866 	case 0x20:
867 		sprintf(buf+len, "SSA\n");
868 		break;
869 	case 0x30:
870 		sprintf(buf+len, "IEEE 1394\n");
871 		break;
872 	case 0x40:
873 		sprintf(buf+len, "SCSI Remote Direct Memory Access"
874 				" Protocol\n");
875 		break;
876 	case 0x50:
877 		sprintf(buf+len, "Internet SCSI (iSCSI)\n");
878 		break;
879 	case 0x60:
880 		sprintf(buf+len, "SAS Serial SCSI Protocol\n");
881 		break;
882 	case 0x70:
883 		sprintf(buf+len, "Automation/Drive Interface Transport"
884 				" Protocol\n");
885 		break;
886 	case 0x80:
887 		sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
888 		break;
889 	default:
890 		sprintf(buf+len, "Unknown 0x%02x\n",
891 				vpd->protocol_identifier);
892 		break;
893 	}
894 
895 	if (p_buf)
896 		strncpy(p_buf, buf, p_buf_len);
897 	else
898 		pr_debug("%s", buf);
899 }
900 
901 void
902 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
903 {
904 	/*
905 	 * Check if the Protocol Identifier Valid (PIV) bit is set..
906 	 *
907 	 * from spc3r23.pdf section 7.5.1
908 	 */
909 	 if (page_83[1] & 0x80) {
910 		vpd->protocol_identifier = (page_83[0] & 0xf0);
911 		vpd->protocol_identifier_set = 1;
912 		transport_dump_vpd_proto_id(vpd, NULL, 0);
913 	}
914 }
915 EXPORT_SYMBOL(transport_set_vpd_proto_id);
916 
917 int transport_dump_vpd_assoc(
918 	struct t10_vpd *vpd,
919 	unsigned char *p_buf,
920 	int p_buf_len)
921 {
922 	unsigned char buf[VPD_TMP_BUF_SIZE];
923 	int ret = 0;
924 	int len;
925 
926 	memset(buf, 0, VPD_TMP_BUF_SIZE);
927 	len = sprintf(buf, "T10 VPD Identifier Association: ");
928 
929 	switch (vpd->association) {
930 	case 0x00:
931 		sprintf(buf+len, "addressed logical unit\n");
932 		break;
933 	case 0x10:
934 		sprintf(buf+len, "target port\n");
935 		break;
936 	case 0x20:
937 		sprintf(buf+len, "SCSI target device\n");
938 		break;
939 	default:
940 		sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
941 		ret = -EINVAL;
942 		break;
943 	}
944 
945 	if (p_buf)
946 		strncpy(p_buf, buf, p_buf_len);
947 	else
948 		pr_debug("%s", buf);
949 
950 	return ret;
951 }
952 
953 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
954 {
955 	/*
956 	 * The VPD identification association..
957 	 *
958 	 * from spc3r23.pdf Section 7.6.3.1 Table 297
959 	 */
960 	vpd->association = (page_83[1] & 0x30);
961 	return transport_dump_vpd_assoc(vpd, NULL, 0);
962 }
963 EXPORT_SYMBOL(transport_set_vpd_assoc);
964 
965 int transport_dump_vpd_ident_type(
966 	struct t10_vpd *vpd,
967 	unsigned char *p_buf,
968 	int p_buf_len)
969 {
970 	unsigned char buf[VPD_TMP_BUF_SIZE];
971 	int ret = 0;
972 	int len;
973 
974 	memset(buf, 0, VPD_TMP_BUF_SIZE);
975 	len = sprintf(buf, "T10 VPD Identifier Type: ");
976 
977 	switch (vpd->device_identifier_type) {
978 	case 0x00:
979 		sprintf(buf+len, "Vendor specific\n");
980 		break;
981 	case 0x01:
982 		sprintf(buf+len, "T10 Vendor ID based\n");
983 		break;
984 	case 0x02:
985 		sprintf(buf+len, "EUI-64 based\n");
986 		break;
987 	case 0x03:
988 		sprintf(buf+len, "NAA\n");
989 		break;
990 	case 0x04:
991 		sprintf(buf+len, "Relative target port identifier\n");
992 		break;
993 	case 0x08:
994 		sprintf(buf+len, "SCSI name string\n");
995 		break;
996 	default:
997 		sprintf(buf+len, "Unsupported: 0x%02x\n",
998 				vpd->device_identifier_type);
999 		ret = -EINVAL;
1000 		break;
1001 	}
1002 
1003 	if (p_buf) {
1004 		if (p_buf_len < strlen(buf)+1)
1005 			return -EINVAL;
1006 		strncpy(p_buf, buf, p_buf_len);
1007 	} else {
1008 		pr_debug("%s", buf);
1009 	}
1010 
1011 	return ret;
1012 }
1013 
1014 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1015 {
1016 	/*
1017 	 * The VPD identifier type..
1018 	 *
1019 	 * from spc3r23.pdf Section 7.6.3.1 Table 298
1020 	 */
1021 	vpd->device_identifier_type = (page_83[1] & 0x0f);
1022 	return transport_dump_vpd_ident_type(vpd, NULL, 0);
1023 }
1024 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1025 
1026 int transport_dump_vpd_ident(
1027 	struct t10_vpd *vpd,
1028 	unsigned char *p_buf,
1029 	int p_buf_len)
1030 {
1031 	unsigned char buf[VPD_TMP_BUF_SIZE];
1032 	int ret = 0;
1033 
1034 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1035 
1036 	switch (vpd->device_identifier_code_set) {
1037 	case 0x01: /* Binary */
1038 		snprintf(buf, sizeof(buf),
1039 			"T10 VPD Binary Device Identifier: %s\n",
1040 			&vpd->device_identifier[0]);
1041 		break;
1042 	case 0x02: /* ASCII */
1043 		snprintf(buf, sizeof(buf),
1044 			"T10 VPD ASCII Device Identifier: %s\n",
1045 			&vpd->device_identifier[0]);
1046 		break;
1047 	case 0x03: /* UTF-8 */
1048 		snprintf(buf, sizeof(buf),
1049 			"T10 VPD UTF-8 Device Identifier: %s\n",
1050 			&vpd->device_identifier[0]);
1051 		break;
1052 	default:
1053 		sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1054 			" 0x%02x", vpd->device_identifier_code_set);
1055 		ret = -EINVAL;
1056 		break;
1057 	}
1058 
1059 	if (p_buf)
1060 		strncpy(p_buf, buf, p_buf_len);
1061 	else
1062 		pr_debug("%s", buf);
1063 
1064 	return ret;
1065 }
1066 
1067 int
1068 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1069 {
1070 	static const char hex_str[] = "0123456789abcdef";
1071 	int j = 0, i = 4; /* offset to start of the identifier */
1072 
1073 	/*
1074 	 * The VPD Code Set (encoding)
1075 	 *
1076 	 * from spc3r23.pdf Section 7.6.3.1 Table 296
1077 	 */
1078 	vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1079 	switch (vpd->device_identifier_code_set) {
1080 	case 0x01: /* Binary */
1081 		vpd->device_identifier[j++] =
1082 				hex_str[vpd->device_identifier_type];
1083 		while (i < (4 + page_83[3])) {
1084 			vpd->device_identifier[j++] =
1085 				hex_str[(page_83[i] & 0xf0) >> 4];
1086 			vpd->device_identifier[j++] =
1087 				hex_str[page_83[i] & 0x0f];
1088 			i++;
1089 		}
1090 		break;
1091 	case 0x02: /* ASCII */
1092 	case 0x03: /* UTF-8 */
1093 		while (i < (4 + page_83[3]))
1094 			vpd->device_identifier[j++] = page_83[i++];
1095 		break;
1096 	default:
1097 		break;
1098 	}
1099 
1100 	return transport_dump_vpd_ident(vpd, NULL, 0);
1101 }
1102 EXPORT_SYMBOL(transport_set_vpd_ident);
1103 
1104 static sense_reason_t
1105 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1106 			       unsigned int size)
1107 {
1108 	u32 mtl;
1109 
1110 	if (!cmd->se_tfo->max_data_sg_nents)
1111 		return TCM_NO_SENSE;
1112 	/*
1113 	 * Check if fabric enforced maximum SGL entries per I/O descriptor
1114 	 * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1115 	 * residual_count and reduce original cmd->data_length to maximum
1116 	 * length based on single PAGE_SIZE entry scatter-lists.
1117 	 */
1118 	mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1119 	if (cmd->data_length > mtl) {
1120 		/*
1121 		 * If an existing CDB overflow is present, calculate new residual
1122 		 * based on CDB size minus fabric maximum transfer length.
1123 		 *
1124 		 * If an existing CDB underflow is present, calculate new residual
1125 		 * based on original cmd->data_length minus fabric maximum transfer
1126 		 * length.
1127 		 *
1128 		 * Otherwise, set the underflow residual based on cmd->data_length
1129 		 * minus fabric maximum transfer length.
1130 		 */
1131 		if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1132 			cmd->residual_count = (size - mtl);
1133 		} else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1134 			u32 orig_dl = size + cmd->residual_count;
1135 			cmd->residual_count = (orig_dl - mtl);
1136 		} else {
1137 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1138 			cmd->residual_count = (cmd->data_length - mtl);
1139 		}
1140 		cmd->data_length = mtl;
1141 		/*
1142 		 * Reset sbc_check_prot() calculated protection payload
1143 		 * length based upon the new smaller MTL.
1144 		 */
1145 		if (cmd->prot_length) {
1146 			u32 sectors = (mtl / dev->dev_attrib.block_size);
1147 			cmd->prot_length = dev->prot_length * sectors;
1148 		}
1149 	}
1150 	return TCM_NO_SENSE;
1151 }
1152 
1153 sense_reason_t
1154 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1155 {
1156 	struct se_device *dev = cmd->se_dev;
1157 
1158 	if (cmd->unknown_data_length) {
1159 		cmd->data_length = size;
1160 	} else if (size != cmd->data_length) {
1161 		pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1162 			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
1163 			" 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1164 				cmd->data_length, size, cmd->t_task_cdb[0]);
1165 
1166 		if (cmd->data_direction == DMA_TO_DEVICE &&
1167 		    cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1168 			pr_err("Rejecting underflow/overflow WRITE data\n");
1169 			return TCM_INVALID_CDB_FIELD;
1170 		}
1171 		/*
1172 		 * Reject READ_* or WRITE_* with overflow/underflow for
1173 		 * type SCF_SCSI_DATA_CDB.
1174 		 */
1175 		if (dev->dev_attrib.block_size != 512)  {
1176 			pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1177 				" CDB on non 512-byte sector setup subsystem"
1178 				" plugin: %s\n", dev->transport->name);
1179 			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1180 			return TCM_INVALID_CDB_FIELD;
1181 		}
1182 		/*
1183 		 * For the overflow case keep the existing fabric provided
1184 		 * ->data_length.  Otherwise for the underflow case, reset
1185 		 * ->data_length to the smaller SCSI expected data transfer
1186 		 * length.
1187 		 */
1188 		if (size > cmd->data_length) {
1189 			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1190 			cmd->residual_count = (size - cmd->data_length);
1191 		} else {
1192 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1193 			cmd->residual_count = (cmd->data_length - size);
1194 			cmd->data_length = size;
1195 		}
1196 	}
1197 
1198 	return target_check_max_data_sg_nents(cmd, dev, size);
1199 
1200 }
1201 
1202 /*
1203  * Used by fabric modules containing a local struct se_cmd within their
1204  * fabric dependent per I/O descriptor.
1205  *
1206  * Preserves the value of @cmd->tag.
1207  */
1208 void transport_init_se_cmd(
1209 	struct se_cmd *cmd,
1210 	const struct target_core_fabric_ops *tfo,
1211 	struct se_session *se_sess,
1212 	u32 data_length,
1213 	int data_direction,
1214 	int task_attr,
1215 	unsigned char *sense_buffer)
1216 {
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->t_transport_stop_comp);
1222 	init_completion(&cmd->cmd_wait_comp);
1223 	spin_lock_init(&cmd->t_state_lock);
1224 	kref_init(&cmd->cmd_kref);
1225 
1226 	cmd->se_tfo = tfo;
1227 	cmd->se_sess = se_sess;
1228 	cmd->data_length = data_length;
1229 	cmd->data_direction = data_direction;
1230 	cmd->sam_task_attr = task_attr;
1231 	cmd->sense_buffer = sense_buffer;
1232 
1233 	cmd->state_active = false;
1234 }
1235 EXPORT_SYMBOL(transport_init_se_cmd);
1236 
1237 static sense_reason_t
1238 transport_check_alloc_task_attr(struct se_cmd *cmd)
1239 {
1240 	struct se_device *dev = cmd->se_dev;
1241 
1242 	/*
1243 	 * Check if SAM Task Attribute emulation is enabled for this
1244 	 * struct se_device storage object
1245 	 */
1246 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1247 		return 0;
1248 
1249 	if (cmd->sam_task_attr == TCM_ACA_TAG) {
1250 		pr_debug("SAM Task Attribute ACA"
1251 			" emulation is not supported\n");
1252 		return TCM_INVALID_CDB_FIELD;
1253 	}
1254 
1255 	return 0;
1256 }
1257 
1258 sense_reason_t
1259 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1260 {
1261 	struct se_device *dev = cmd->se_dev;
1262 	sense_reason_t ret;
1263 
1264 	/*
1265 	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1266 	 * for VARIABLE_LENGTH_CMD
1267 	 */
1268 	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1269 		pr_err("Received SCSI CDB with command_size: %d that"
1270 			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1271 			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1272 		return TCM_INVALID_CDB_FIELD;
1273 	}
1274 	/*
1275 	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1276 	 * allocate the additional extended CDB buffer now..  Otherwise
1277 	 * setup the pointer from __t_task_cdb to t_task_cdb.
1278 	 */
1279 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1280 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1281 						GFP_KERNEL);
1282 		if (!cmd->t_task_cdb) {
1283 			pr_err("Unable to allocate cmd->t_task_cdb"
1284 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1285 				scsi_command_size(cdb),
1286 				(unsigned long)sizeof(cmd->__t_task_cdb));
1287 			return TCM_OUT_OF_RESOURCES;
1288 		}
1289 	} else
1290 		cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1291 	/*
1292 	 * Copy the original CDB into cmd->
1293 	 */
1294 	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1295 
1296 	trace_target_sequencer_start(cmd);
1297 
1298 	ret = dev->transport->parse_cdb(cmd);
1299 	if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1300 		pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1301 				    cmd->se_tfo->get_fabric_name(),
1302 				    cmd->se_sess->se_node_acl->initiatorname,
1303 				    cmd->t_task_cdb[0]);
1304 	if (ret)
1305 		return ret;
1306 
1307 	ret = transport_check_alloc_task_attr(cmd);
1308 	if (ret)
1309 		return ret;
1310 
1311 	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1312 	atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1313 	return 0;
1314 }
1315 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1316 
1317 /*
1318  * Used by fabric module frontends to queue tasks directly.
1319  * May only be used from process context.
1320  */
1321 int transport_handle_cdb_direct(
1322 	struct se_cmd *cmd)
1323 {
1324 	sense_reason_t ret;
1325 
1326 	if (!cmd->se_lun) {
1327 		dump_stack();
1328 		pr_err("cmd->se_lun is NULL\n");
1329 		return -EINVAL;
1330 	}
1331 	if (in_interrupt()) {
1332 		dump_stack();
1333 		pr_err("transport_generic_handle_cdb cannot be called"
1334 				" from interrupt context\n");
1335 		return -EINVAL;
1336 	}
1337 	/*
1338 	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1339 	 * outstanding descriptors are handled correctly during shutdown via
1340 	 * transport_wait_for_tasks()
1341 	 *
1342 	 * Also, we don't take cmd->t_state_lock here as we only expect
1343 	 * this to be called for initial descriptor submission.
1344 	 */
1345 	cmd->t_state = TRANSPORT_NEW_CMD;
1346 	cmd->transport_state |= CMD_T_ACTIVE;
1347 
1348 	/*
1349 	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1350 	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1351 	 * and call transport_generic_request_failure() if necessary..
1352 	 */
1353 	ret = transport_generic_new_cmd(cmd);
1354 	if (ret)
1355 		transport_generic_request_failure(cmd, ret);
1356 	return 0;
1357 }
1358 EXPORT_SYMBOL(transport_handle_cdb_direct);
1359 
1360 sense_reason_t
1361 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1362 		u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1363 {
1364 	if (!sgl || !sgl_count)
1365 		return 0;
1366 
1367 	/*
1368 	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1369 	 * scatterlists already have been set to follow what the fabric
1370 	 * passes for the original expected data transfer length.
1371 	 */
1372 	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1373 		pr_warn("Rejecting SCSI DATA overflow for fabric using"
1374 			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1375 		return TCM_INVALID_CDB_FIELD;
1376 	}
1377 
1378 	cmd->t_data_sg = sgl;
1379 	cmd->t_data_nents = sgl_count;
1380 	cmd->t_bidi_data_sg = sgl_bidi;
1381 	cmd->t_bidi_data_nents = sgl_bidi_count;
1382 
1383 	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1384 	return 0;
1385 }
1386 
1387 /*
1388  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1389  * 			 se_cmd + use pre-allocated SGL memory.
1390  *
1391  * @se_cmd: command descriptor to submit
1392  * @se_sess: associated se_sess for endpoint
1393  * @cdb: pointer to SCSI CDB
1394  * @sense: pointer to SCSI sense buffer
1395  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1396  * @data_length: fabric expected data transfer length
1397  * @task_addr: SAM task attribute
1398  * @data_dir: DMA data direction
1399  * @flags: flags for command submission from target_sc_flags_tables
1400  * @sgl: struct scatterlist memory for unidirectional mapping
1401  * @sgl_count: scatterlist count for unidirectional mapping
1402  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1403  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1404  * @sgl_prot: struct scatterlist memory protection information
1405  * @sgl_prot_count: scatterlist count for protection information
1406  *
1407  * Task tags are supported if the caller has set @se_cmd->tag.
1408  *
1409  * Returns non zero to signal active I/O shutdown failure.  All other
1410  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1411  * but still return zero here.
1412  *
1413  * This may only be called from process context, and also currently
1414  * assumes internal allocation of fabric payload buffer by target-core.
1415  */
1416 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1417 		unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1418 		u32 data_length, int task_attr, int data_dir, int flags,
1419 		struct scatterlist *sgl, u32 sgl_count,
1420 		struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1421 		struct scatterlist *sgl_prot, u32 sgl_prot_count)
1422 {
1423 	struct se_portal_group *se_tpg;
1424 	sense_reason_t rc;
1425 	int ret;
1426 
1427 	se_tpg = se_sess->se_tpg;
1428 	BUG_ON(!se_tpg);
1429 	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1430 	BUG_ON(in_interrupt());
1431 	/*
1432 	 * Initialize se_cmd for target operation.  From this point
1433 	 * exceptions are handled by sending exception status via
1434 	 * target_core_fabric_ops->queue_status() callback
1435 	 */
1436 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1437 				data_length, data_dir, task_attr, sense);
1438 
1439 	if (flags & TARGET_SCF_USE_CPUID)
1440 		se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1441 	else
1442 		se_cmd->cpuid = WORK_CPU_UNBOUND;
1443 
1444 	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1445 		se_cmd->unknown_data_length = 1;
1446 	/*
1447 	 * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1448 	 * se_sess->sess_cmd_list.  A second kref_get here is necessary
1449 	 * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1450 	 * kref_put() to happen during fabric packet acknowledgement.
1451 	 */
1452 	ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1453 	if (ret)
1454 		return ret;
1455 	/*
1456 	 * Signal bidirectional data payloads to target-core
1457 	 */
1458 	if (flags & TARGET_SCF_BIDI_OP)
1459 		se_cmd->se_cmd_flags |= SCF_BIDI;
1460 	/*
1461 	 * Locate se_lun pointer and attach it to struct se_cmd
1462 	 */
1463 	rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1464 	if (rc) {
1465 		transport_send_check_condition_and_sense(se_cmd, rc, 0);
1466 		target_put_sess_cmd(se_cmd);
1467 		return 0;
1468 	}
1469 
1470 	rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1471 	if (rc != 0) {
1472 		transport_generic_request_failure(se_cmd, rc);
1473 		return 0;
1474 	}
1475 
1476 	/*
1477 	 * Save pointers for SGLs containing protection information,
1478 	 * if present.
1479 	 */
1480 	if (sgl_prot_count) {
1481 		se_cmd->t_prot_sg = sgl_prot;
1482 		se_cmd->t_prot_nents = sgl_prot_count;
1483 		se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1484 	}
1485 
1486 	/*
1487 	 * When a non zero sgl_count has been passed perform SGL passthrough
1488 	 * mapping for pre-allocated fabric memory instead of having target
1489 	 * core perform an internal SGL allocation..
1490 	 */
1491 	if (sgl_count != 0) {
1492 		BUG_ON(!sgl);
1493 
1494 		/*
1495 		 * A work-around for tcm_loop as some userspace code via
1496 		 * scsi-generic do not memset their associated read buffers,
1497 		 * so go ahead and do that here for type non-data CDBs.  Also
1498 		 * note that this is currently guaranteed to be a single SGL
1499 		 * for this case by target core in target_setup_cmd_from_cdb()
1500 		 * -> transport_generic_cmd_sequencer().
1501 		 */
1502 		if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1503 		     se_cmd->data_direction == DMA_FROM_DEVICE) {
1504 			unsigned char *buf = NULL;
1505 
1506 			if (sgl)
1507 				buf = kmap(sg_page(sgl)) + sgl->offset;
1508 
1509 			if (buf) {
1510 				memset(buf, 0, sgl->length);
1511 				kunmap(sg_page(sgl));
1512 			}
1513 		}
1514 
1515 		rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1516 				sgl_bidi, sgl_bidi_count);
1517 		if (rc != 0) {
1518 			transport_generic_request_failure(se_cmd, rc);
1519 			return 0;
1520 		}
1521 	}
1522 
1523 	/*
1524 	 * Check if we need to delay processing because of ALUA
1525 	 * Active/NonOptimized primary access state..
1526 	 */
1527 	core_alua_check_nonop_delay(se_cmd);
1528 
1529 	transport_handle_cdb_direct(se_cmd);
1530 	return 0;
1531 }
1532 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1533 
1534 /*
1535  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1536  *
1537  * @se_cmd: command descriptor to submit
1538  * @se_sess: associated se_sess for endpoint
1539  * @cdb: pointer to SCSI CDB
1540  * @sense: pointer to SCSI sense buffer
1541  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1542  * @data_length: fabric expected data transfer length
1543  * @task_addr: SAM task attribute
1544  * @data_dir: DMA data direction
1545  * @flags: flags for command submission from target_sc_flags_tables
1546  *
1547  * Task tags are supported if the caller has set @se_cmd->tag.
1548  *
1549  * Returns non zero to signal active I/O shutdown failure.  All other
1550  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1551  * but still return zero here.
1552  *
1553  * This may only be called from process context, and also currently
1554  * assumes internal allocation of fabric payload buffer by target-core.
1555  *
1556  * It also assumes interal target core SGL memory allocation.
1557  */
1558 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1559 		unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1560 		u32 data_length, int task_attr, int data_dir, int flags)
1561 {
1562 	return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1563 			unpacked_lun, data_length, task_attr, data_dir,
1564 			flags, NULL, 0, NULL, 0, NULL, 0);
1565 }
1566 EXPORT_SYMBOL(target_submit_cmd);
1567 
1568 static void target_complete_tmr_failure(struct work_struct *work)
1569 {
1570 	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1571 
1572 	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1573 	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1574 
1575 	transport_cmd_check_stop_to_fabric(se_cmd);
1576 }
1577 
1578 /**
1579  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1580  *                     for TMR CDBs
1581  *
1582  * @se_cmd: command descriptor to submit
1583  * @se_sess: associated se_sess for endpoint
1584  * @sense: pointer to SCSI sense buffer
1585  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1586  * @fabric_context: fabric context for TMR req
1587  * @tm_type: Type of TM request
1588  * @gfp: gfp type for caller
1589  * @tag: referenced task tag for TMR_ABORT_TASK
1590  * @flags: submit cmd flags
1591  *
1592  * Callable from all contexts.
1593  **/
1594 
1595 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1596 		unsigned char *sense, u64 unpacked_lun,
1597 		void *fabric_tmr_ptr, unsigned char tm_type,
1598 		gfp_t gfp, u64 tag, int flags)
1599 {
1600 	struct se_portal_group *se_tpg;
1601 	int ret;
1602 
1603 	se_tpg = se_sess->se_tpg;
1604 	BUG_ON(!se_tpg);
1605 
1606 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1607 			      0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1608 	/*
1609 	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1610 	 * allocation failure.
1611 	 */
1612 	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1613 	if (ret < 0)
1614 		return -ENOMEM;
1615 
1616 	if (tm_type == TMR_ABORT_TASK)
1617 		se_cmd->se_tmr_req->ref_task_tag = tag;
1618 
1619 	/* See target_submit_cmd for commentary */
1620 	ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1621 	if (ret) {
1622 		core_tmr_release_req(se_cmd->se_tmr_req);
1623 		return ret;
1624 	}
1625 
1626 	ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1627 	if (ret) {
1628 		/*
1629 		 * For callback during failure handling, push this work off
1630 		 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1631 		 */
1632 		INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1633 		schedule_work(&se_cmd->work);
1634 		return 0;
1635 	}
1636 	transport_generic_handle_tmr(se_cmd);
1637 	return 0;
1638 }
1639 EXPORT_SYMBOL(target_submit_tmr);
1640 
1641 /*
1642  * Handle SAM-esque emulation for generic transport request failures.
1643  */
1644 void transport_generic_request_failure(struct se_cmd *cmd,
1645 		sense_reason_t sense_reason)
1646 {
1647 	int ret = 0, post_ret = 0;
1648 
1649 	if (transport_check_aborted_status(cmd, 1))
1650 		return;
1651 
1652 	pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08llx"
1653 		" CDB: 0x%02x\n", cmd, cmd->tag, cmd->t_task_cdb[0]);
1654 	pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1655 		cmd->se_tfo->get_cmd_state(cmd),
1656 		cmd->t_state, sense_reason);
1657 	pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1658 		(cmd->transport_state & CMD_T_ACTIVE) != 0,
1659 		(cmd->transport_state & CMD_T_STOP) != 0,
1660 		(cmd->transport_state & CMD_T_SENT) != 0);
1661 
1662 	/*
1663 	 * For SAM Task Attribute emulation for failed struct se_cmd
1664 	 */
1665 	transport_complete_task_attr(cmd);
1666 	/*
1667 	 * Handle special case for COMPARE_AND_WRITE failure, where the
1668 	 * callback is expected to drop the per device ->caw_sem.
1669 	 */
1670 	if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1671 	     cmd->transport_complete_callback)
1672 		cmd->transport_complete_callback(cmd, false, &post_ret);
1673 
1674 	switch (sense_reason) {
1675 	case TCM_NON_EXISTENT_LUN:
1676 	case TCM_UNSUPPORTED_SCSI_OPCODE:
1677 	case TCM_INVALID_CDB_FIELD:
1678 	case TCM_INVALID_PARAMETER_LIST:
1679 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
1680 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1681 	case TCM_UNKNOWN_MODE_PAGE:
1682 	case TCM_WRITE_PROTECTED:
1683 	case TCM_ADDRESS_OUT_OF_RANGE:
1684 	case TCM_CHECK_CONDITION_ABORT_CMD:
1685 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1686 	case TCM_CHECK_CONDITION_NOT_READY:
1687 	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1688 	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1689 	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1690 	case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
1691 	case TCM_TOO_MANY_TARGET_DESCS:
1692 	case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
1693 	case TCM_TOO_MANY_SEGMENT_DESCS:
1694 	case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
1695 		break;
1696 	case TCM_OUT_OF_RESOURCES:
1697 		sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1698 		break;
1699 	case TCM_RESERVATION_CONFLICT:
1700 		/*
1701 		 * No SENSE Data payload for this case, set SCSI Status
1702 		 * and queue the response to $FABRIC_MOD.
1703 		 *
1704 		 * Uses linux/include/scsi/scsi.h SAM status codes defs
1705 		 */
1706 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1707 		/*
1708 		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1709 		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1710 		 * CONFLICT STATUS.
1711 		 *
1712 		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1713 		 */
1714 		if (cmd->se_sess &&
1715 		    cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1716 			target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1717 					       cmd->orig_fe_lun, 0x2C,
1718 					ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1719 		}
1720 		trace_target_cmd_complete(cmd);
1721 		ret = cmd->se_tfo->queue_status(cmd);
1722 		if (ret == -EAGAIN || ret == -ENOMEM)
1723 			goto queue_full;
1724 		goto check_stop;
1725 	default:
1726 		pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1727 			cmd->t_task_cdb[0], sense_reason);
1728 		sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1729 		break;
1730 	}
1731 
1732 	ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1733 	if (ret == -EAGAIN || ret == -ENOMEM)
1734 		goto queue_full;
1735 
1736 check_stop:
1737 	transport_lun_remove_cmd(cmd);
1738 	transport_cmd_check_stop_to_fabric(cmd);
1739 	return;
1740 
1741 queue_full:
1742 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1743 	transport_handle_queue_full(cmd, cmd->se_dev);
1744 }
1745 EXPORT_SYMBOL(transport_generic_request_failure);
1746 
1747 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
1748 {
1749 	sense_reason_t ret;
1750 
1751 	if (!cmd->execute_cmd) {
1752 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1753 		goto err;
1754 	}
1755 	if (do_checks) {
1756 		/*
1757 		 * Check for an existing UNIT ATTENTION condition after
1758 		 * target_handle_task_attr() has done SAM task attr
1759 		 * checking, and possibly have already defered execution
1760 		 * out to target_restart_delayed_cmds() context.
1761 		 */
1762 		ret = target_scsi3_ua_check(cmd);
1763 		if (ret)
1764 			goto err;
1765 
1766 		ret = target_alua_state_check(cmd);
1767 		if (ret)
1768 			goto err;
1769 
1770 		ret = target_check_reservation(cmd);
1771 		if (ret) {
1772 			cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1773 			goto err;
1774 		}
1775 	}
1776 
1777 	ret = cmd->execute_cmd(cmd);
1778 	if (!ret)
1779 		return;
1780 err:
1781 	spin_lock_irq(&cmd->t_state_lock);
1782 	cmd->transport_state &= ~CMD_T_SENT;
1783 	spin_unlock_irq(&cmd->t_state_lock);
1784 
1785 	transport_generic_request_failure(cmd, ret);
1786 }
1787 
1788 static int target_write_prot_action(struct se_cmd *cmd)
1789 {
1790 	u32 sectors;
1791 	/*
1792 	 * Perform WRITE_INSERT of PI using software emulation when backend
1793 	 * device has PI enabled, if the transport has not already generated
1794 	 * PI using hardware WRITE_INSERT offload.
1795 	 */
1796 	switch (cmd->prot_op) {
1797 	case TARGET_PROT_DOUT_INSERT:
1798 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1799 			sbc_dif_generate(cmd);
1800 		break;
1801 	case TARGET_PROT_DOUT_STRIP:
1802 		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1803 			break;
1804 
1805 		sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1806 		cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1807 					     sectors, 0, cmd->t_prot_sg, 0);
1808 		if (unlikely(cmd->pi_err)) {
1809 			spin_lock_irq(&cmd->t_state_lock);
1810 			cmd->transport_state &= ~CMD_T_SENT;
1811 			spin_unlock_irq(&cmd->t_state_lock);
1812 			transport_generic_request_failure(cmd, cmd->pi_err);
1813 			return -1;
1814 		}
1815 		break;
1816 	default:
1817 		break;
1818 	}
1819 
1820 	return 0;
1821 }
1822 
1823 static bool target_handle_task_attr(struct se_cmd *cmd)
1824 {
1825 	struct se_device *dev = cmd->se_dev;
1826 
1827 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1828 		return false;
1829 
1830 	cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
1831 
1832 	/*
1833 	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1834 	 * to allow the passed struct se_cmd list of tasks to the front of the list.
1835 	 */
1836 	switch (cmd->sam_task_attr) {
1837 	case TCM_HEAD_TAG:
1838 		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
1839 			 cmd->t_task_cdb[0]);
1840 		return false;
1841 	case TCM_ORDERED_TAG:
1842 		atomic_inc_mb(&dev->dev_ordered_sync);
1843 
1844 		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
1845 			 cmd->t_task_cdb[0]);
1846 
1847 		/*
1848 		 * Execute an ORDERED command if no other older commands
1849 		 * exist that need to be completed first.
1850 		 */
1851 		if (!atomic_read(&dev->simple_cmds))
1852 			return false;
1853 		break;
1854 	default:
1855 		/*
1856 		 * For SIMPLE and UNTAGGED Task Attribute commands
1857 		 */
1858 		atomic_inc_mb(&dev->simple_cmds);
1859 		break;
1860 	}
1861 
1862 	if (atomic_read(&dev->dev_ordered_sync) == 0)
1863 		return false;
1864 
1865 	spin_lock(&dev->delayed_cmd_lock);
1866 	list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1867 	spin_unlock(&dev->delayed_cmd_lock);
1868 
1869 	pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
1870 		cmd->t_task_cdb[0], cmd->sam_task_attr);
1871 	return true;
1872 }
1873 
1874 static int __transport_check_aborted_status(struct se_cmd *, int);
1875 
1876 void target_execute_cmd(struct se_cmd *cmd)
1877 {
1878 	/*
1879 	 * Determine if frontend context caller is requesting the stopping of
1880 	 * this command for frontend exceptions.
1881 	 *
1882 	 * If the received CDB has aleady been aborted stop processing it here.
1883 	 */
1884 	spin_lock_irq(&cmd->t_state_lock);
1885 	if (__transport_check_aborted_status(cmd, 1)) {
1886 		spin_unlock_irq(&cmd->t_state_lock);
1887 		return;
1888 	}
1889 	if (cmd->transport_state & CMD_T_STOP) {
1890 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
1891 			__func__, __LINE__, cmd->tag);
1892 
1893 		spin_unlock_irq(&cmd->t_state_lock);
1894 		complete_all(&cmd->t_transport_stop_comp);
1895 		return;
1896 	}
1897 
1898 	cmd->t_state = TRANSPORT_PROCESSING;
1899 	cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
1900 	spin_unlock_irq(&cmd->t_state_lock);
1901 
1902 	if (target_write_prot_action(cmd))
1903 		return;
1904 
1905 	if (target_handle_task_attr(cmd)) {
1906 		spin_lock_irq(&cmd->t_state_lock);
1907 		cmd->transport_state &= ~CMD_T_SENT;
1908 		spin_unlock_irq(&cmd->t_state_lock);
1909 		return;
1910 	}
1911 
1912 	__target_execute_cmd(cmd, true);
1913 }
1914 EXPORT_SYMBOL(target_execute_cmd);
1915 
1916 /*
1917  * Process all commands up to the last received ORDERED task attribute which
1918  * requires another blocking boundary
1919  */
1920 static void target_restart_delayed_cmds(struct se_device *dev)
1921 {
1922 	for (;;) {
1923 		struct se_cmd *cmd;
1924 
1925 		spin_lock(&dev->delayed_cmd_lock);
1926 		if (list_empty(&dev->delayed_cmd_list)) {
1927 			spin_unlock(&dev->delayed_cmd_lock);
1928 			break;
1929 		}
1930 
1931 		cmd = list_entry(dev->delayed_cmd_list.next,
1932 				 struct se_cmd, se_delayed_node);
1933 		list_del(&cmd->se_delayed_node);
1934 		spin_unlock(&dev->delayed_cmd_lock);
1935 
1936 		__target_execute_cmd(cmd, true);
1937 
1938 		if (cmd->sam_task_attr == TCM_ORDERED_TAG)
1939 			break;
1940 	}
1941 }
1942 
1943 /*
1944  * Called from I/O completion to determine which dormant/delayed
1945  * and ordered cmds need to have their tasks added to the execution queue.
1946  */
1947 static void transport_complete_task_attr(struct se_cmd *cmd)
1948 {
1949 	struct se_device *dev = cmd->se_dev;
1950 
1951 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1952 		return;
1953 
1954 	if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
1955 		goto restart;
1956 
1957 	if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
1958 		atomic_dec_mb(&dev->simple_cmds);
1959 		dev->dev_cur_ordered_id++;
1960 	} else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
1961 		dev->dev_cur_ordered_id++;
1962 		pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
1963 			 dev->dev_cur_ordered_id);
1964 	} else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
1965 		atomic_dec_mb(&dev->dev_ordered_sync);
1966 
1967 		dev->dev_cur_ordered_id++;
1968 		pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
1969 			 dev->dev_cur_ordered_id);
1970 	}
1971 restart:
1972 	target_restart_delayed_cmds(dev);
1973 }
1974 
1975 static void transport_complete_qf(struct se_cmd *cmd)
1976 {
1977 	int ret = 0;
1978 
1979 	transport_complete_task_attr(cmd);
1980 
1981 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1982 		trace_target_cmd_complete(cmd);
1983 		ret = cmd->se_tfo->queue_status(cmd);
1984 		goto out;
1985 	}
1986 
1987 	switch (cmd->data_direction) {
1988 	case DMA_FROM_DEVICE:
1989 		if (cmd->scsi_status)
1990 			goto queue_status;
1991 
1992 		trace_target_cmd_complete(cmd);
1993 		ret = cmd->se_tfo->queue_data_in(cmd);
1994 		break;
1995 	case DMA_TO_DEVICE:
1996 		if (cmd->se_cmd_flags & SCF_BIDI) {
1997 			ret = cmd->se_tfo->queue_data_in(cmd);
1998 			break;
1999 		}
2000 		/* Fall through for DMA_TO_DEVICE */
2001 	case DMA_NONE:
2002 queue_status:
2003 		trace_target_cmd_complete(cmd);
2004 		ret = cmd->se_tfo->queue_status(cmd);
2005 		break;
2006 	default:
2007 		break;
2008 	}
2009 
2010 out:
2011 	if (ret < 0) {
2012 		transport_handle_queue_full(cmd, cmd->se_dev);
2013 		return;
2014 	}
2015 	transport_lun_remove_cmd(cmd);
2016 	transport_cmd_check_stop_to_fabric(cmd);
2017 }
2018 
2019 static void transport_handle_queue_full(
2020 	struct se_cmd *cmd,
2021 	struct se_device *dev)
2022 {
2023 	spin_lock_irq(&dev->qf_cmd_lock);
2024 	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2025 	atomic_inc_mb(&dev->dev_qf_count);
2026 	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2027 
2028 	schedule_work(&cmd->se_dev->qf_work_queue);
2029 }
2030 
2031 static bool target_read_prot_action(struct se_cmd *cmd)
2032 {
2033 	switch (cmd->prot_op) {
2034 	case TARGET_PROT_DIN_STRIP:
2035 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2036 			u32 sectors = cmd->data_length >>
2037 				  ilog2(cmd->se_dev->dev_attrib.block_size);
2038 
2039 			cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2040 						     sectors, 0, cmd->t_prot_sg,
2041 						     0);
2042 			if (cmd->pi_err)
2043 				return true;
2044 		}
2045 		break;
2046 	case TARGET_PROT_DIN_INSERT:
2047 		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2048 			break;
2049 
2050 		sbc_dif_generate(cmd);
2051 		break;
2052 	default:
2053 		break;
2054 	}
2055 
2056 	return false;
2057 }
2058 
2059 static void target_complete_ok_work(struct work_struct *work)
2060 {
2061 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2062 	int ret;
2063 
2064 	/*
2065 	 * Check if we need to move delayed/dormant tasks from cmds on the
2066 	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2067 	 * Attribute.
2068 	 */
2069 	transport_complete_task_attr(cmd);
2070 
2071 	/*
2072 	 * Check to schedule QUEUE_FULL work, or execute an existing
2073 	 * cmd->transport_qf_callback()
2074 	 */
2075 	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2076 		schedule_work(&cmd->se_dev->qf_work_queue);
2077 
2078 	/*
2079 	 * Check if we need to send a sense buffer from
2080 	 * the struct se_cmd in question.
2081 	 */
2082 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2083 		WARN_ON(!cmd->scsi_status);
2084 		ret = transport_send_check_condition_and_sense(
2085 					cmd, 0, 1);
2086 		if (ret == -EAGAIN || ret == -ENOMEM)
2087 			goto queue_full;
2088 
2089 		transport_lun_remove_cmd(cmd);
2090 		transport_cmd_check_stop_to_fabric(cmd);
2091 		return;
2092 	}
2093 	/*
2094 	 * Check for a callback, used by amongst other things
2095 	 * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2096 	 */
2097 	if (cmd->transport_complete_callback) {
2098 		sense_reason_t rc;
2099 		bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2100 		bool zero_dl = !(cmd->data_length);
2101 		int post_ret = 0;
2102 
2103 		rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2104 		if (!rc && !post_ret) {
2105 			if (caw && zero_dl)
2106 				goto queue_rsp;
2107 
2108 			return;
2109 		} else if (rc) {
2110 			ret = transport_send_check_condition_and_sense(cmd,
2111 						rc, 0);
2112 			if (ret == -EAGAIN || ret == -ENOMEM)
2113 				goto queue_full;
2114 
2115 			transport_lun_remove_cmd(cmd);
2116 			transport_cmd_check_stop_to_fabric(cmd);
2117 			return;
2118 		}
2119 	}
2120 
2121 queue_rsp:
2122 	switch (cmd->data_direction) {
2123 	case DMA_FROM_DEVICE:
2124 		if (cmd->scsi_status)
2125 			goto queue_status;
2126 
2127 		atomic_long_add(cmd->data_length,
2128 				&cmd->se_lun->lun_stats.tx_data_octets);
2129 		/*
2130 		 * Perform READ_STRIP of PI using software emulation when
2131 		 * backend had PI enabled, if the transport will not be
2132 		 * performing hardware READ_STRIP offload.
2133 		 */
2134 		if (target_read_prot_action(cmd)) {
2135 			ret = transport_send_check_condition_and_sense(cmd,
2136 						cmd->pi_err, 0);
2137 			if (ret == -EAGAIN || ret == -ENOMEM)
2138 				goto queue_full;
2139 
2140 			transport_lun_remove_cmd(cmd);
2141 			transport_cmd_check_stop_to_fabric(cmd);
2142 			return;
2143 		}
2144 
2145 		trace_target_cmd_complete(cmd);
2146 		ret = cmd->se_tfo->queue_data_in(cmd);
2147 		if (ret == -EAGAIN || ret == -ENOMEM)
2148 			goto queue_full;
2149 		break;
2150 	case DMA_TO_DEVICE:
2151 		atomic_long_add(cmd->data_length,
2152 				&cmd->se_lun->lun_stats.rx_data_octets);
2153 		/*
2154 		 * Check if we need to send READ payload for BIDI-COMMAND
2155 		 */
2156 		if (cmd->se_cmd_flags & SCF_BIDI) {
2157 			atomic_long_add(cmd->data_length,
2158 					&cmd->se_lun->lun_stats.tx_data_octets);
2159 			ret = cmd->se_tfo->queue_data_in(cmd);
2160 			if (ret == -EAGAIN || ret == -ENOMEM)
2161 				goto queue_full;
2162 			break;
2163 		}
2164 		/* Fall through for DMA_TO_DEVICE */
2165 	case DMA_NONE:
2166 queue_status:
2167 		trace_target_cmd_complete(cmd);
2168 		ret = cmd->se_tfo->queue_status(cmd);
2169 		if (ret == -EAGAIN || ret == -ENOMEM)
2170 			goto queue_full;
2171 		break;
2172 	default:
2173 		break;
2174 	}
2175 
2176 	transport_lun_remove_cmd(cmd);
2177 	transport_cmd_check_stop_to_fabric(cmd);
2178 	return;
2179 
2180 queue_full:
2181 	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2182 		" data_direction: %d\n", cmd, cmd->data_direction);
2183 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2184 	transport_handle_queue_full(cmd, cmd->se_dev);
2185 }
2186 
2187 void target_free_sgl(struct scatterlist *sgl, int nents)
2188 {
2189 	struct scatterlist *sg;
2190 	int count;
2191 
2192 	for_each_sg(sgl, sg, nents, count)
2193 		__free_page(sg_page(sg));
2194 
2195 	kfree(sgl);
2196 }
2197 EXPORT_SYMBOL(target_free_sgl);
2198 
2199 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2200 {
2201 	/*
2202 	 * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2203 	 * emulation, and free + reset pointers if necessary..
2204 	 */
2205 	if (!cmd->t_data_sg_orig)
2206 		return;
2207 
2208 	kfree(cmd->t_data_sg);
2209 	cmd->t_data_sg = cmd->t_data_sg_orig;
2210 	cmd->t_data_sg_orig = NULL;
2211 	cmd->t_data_nents = cmd->t_data_nents_orig;
2212 	cmd->t_data_nents_orig = 0;
2213 }
2214 
2215 static inline void transport_free_pages(struct se_cmd *cmd)
2216 {
2217 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2218 		target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2219 		cmd->t_prot_sg = NULL;
2220 		cmd->t_prot_nents = 0;
2221 	}
2222 
2223 	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2224 		/*
2225 		 * Release special case READ buffer payload required for
2226 		 * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2227 		 */
2228 		if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2229 			target_free_sgl(cmd->t_bidi_data_sg,
2230 					   cmd->t_bidi_data_nents);
2231 			cmd->t_bidi_data_sg = NULL;
2232 			cmd->t_bidi_data_nents = 0;
2233 		}
2234 		transport_reset_sgl_orig(cmd);
2235 		return;
2236 	}
2237 	transport_reset_sgl_orig(cmd);
2238 
2239 	target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2240 	cmd->t_data_sg = NULL;
2241 	cmd->t_data_nents = 0;
2242 
2243 	target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2244 	cmd->t_bidi_data_sg = NULL;
2245 	cmd->t_bidi_data_nents = 0;
2246 }
2247 
2248 /**
2249  * transport_put_cmd - release a reference to a command
2250  * @cmd:       command to release
2251  *
2252  * This routine releases our reference to the command and frees it if possible.
2253  */
2254 static int transport_put_cmd(struct se_cmd *cmd)
2255 {
2256 	BUG_ON(!cmd->se_tfo);
2257 	/*
2258 	 * If this cmd has been setup with target_get_sess_cmd(), drop
2259 	 * the kref and call ->release_cmd() in kref callback.
2260 	 */
2261 	return target_put_sess_cmd(cmd);
2262 }
2263 
2264 void *transport_kmap_data_sg(struct se_cmd *cmd)
2265 {
2266 	struct scatterlist *sg = cmd->t_data_sg;
2267 	struct page **pages;
2268 	int i;
2269 
2270 	/*
2271 	 * We need to take into account a possible offset here for fabrics like
2272 	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2273 	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2274 	 */
2275 	if (!cmd->t_data_nents)
2276 		return NULL;
2277 
2278 	BUG_ON(!sg);
2279 	if (cmd->t_data_nents == 1)
2280 		return kmap(sg_page(sg)) + sg->offset;
2281 
2282 	/* >1 page. use vmap */
2283 	pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2284 	if (!pages)
2285 		return NULL;
2286 
2287 	/* convert sg[] to pages[] */
2288 	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2289 		pages[i] = sg_page(sg);
2290 	}
2291 
2292 	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2293 	kfree(pages);
2294 	if (!cmd->t_data_vmap)
2295 		return NULL;
2296 
2297 	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2298 }
2299 EXPORT_SYMBOL(transport_kmap_data_sg);
2300 
2301 void transport_kunmap_data_sg(struct se_cmd *cmd)
2302 {
2303 	if (!cmd->t_data_nents) {
2304 		return;
2305 	} else if (cmd->t_data_nents == 1) {
2306 		kunmap(sg_page(cmd->t_data_sg));
2307 		return;
2308 	}
2309 
2310 	vunmap(cmd->t_data_vmap);
2311 	cmd->t_data_vmap = NULL;
2312 }
2313 EXPORT_SYMBOL(transport_kunmap_data_sg);
2314 
2315 int
2316 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2317 		 bool zero_page, bool chainable)
2318 {
2319 	struct scatterlist *sg;
2320 	struct page *page;
2321 	gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2322 	unsigned int nalloc, nent;
2323 	int i = 0;
2324 
2325 	nalloc = nent = DIV_ROUND_UP(length, PAGE_SIZE);
2326 	if (chainable)
2327 		nalloc++;
2328 	sg = kmalloc_array(nalloc, sizeof(struct scatterlist), GFP_KERNEL);
2329 	if (!sg)
2330 		return -ENOMEM;
2331 
2332 	sg_init_table(sg, nalloc);
2333 
2334 	while (length) {
2335 		u32 page_len = min_t(u32, length, PAGE_SIZE);
2336 		page = alloc_page(GFP_KERNEL | zero_flag);
2337 		if (!page)
2338 			goto out;
2339 
2340 		sg_set_page(&sg[i], page, page_len, 0);
2341 		length -= page_len;
2342 		i++;
2343 	}
2344 	*sgl = sg;
2345 	*nents = nent;
2346 	return 0;
2347 
2348 out:
2349 	while (i > 0) {
2350 		i--;
2351 		__free_page(sg_page(&sg[i]));
2352 	}
2353 	kfree(sg);
2354 	return -ENOMEM;
2355 }
2356 EXPORT_SYMBOL(target_alloc_sgl);
2357 
2358 /*
2359  * Allocate any required resources to execute the command.  For writes we
2360  * might not have the payload yet, so notify the fabric via a call to
2361  * ->write_pending instead. Otherwise place it on the execution queue.
2362  */
2363 sense_reason_t
2364 transport_generic_new_cmd(struct se_cmd *cmd)
2365 {
2366 	unsigned long flags;
2367 	int ret = 0;
2368 	bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2369 
2370 	if (cmd->prot_op != TARGET_PROT_NORMAL &&
2371 	    !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2372 		ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2373 				       cmd->prot_length, true, false);
2374 		if (ret < 0)
2375 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2376 	}
2377 
2378 	/*
2379 	 * Determine is the TCM fabric module has already allocated physical
2380 	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2381 	 * beforehand.
2382 	 */
2383 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2384 	    cmd->data_length) {
2385 
2386 		if ((cmd->se_cmd_flags & SCF_BIDI) ||
2387 		    (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2388 			u32 bidi_length;
2389 
2390 			if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2391 				bidi_length = cmd->t_task_nolb *
2392 					      cmd->se_dev->dev_attrib.block_size;
2393 			else
2394 				bidi_length = cmd->data_length;
2395 
2396 			ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2397 					       &cmd->t_bidi_data_nents,
2398 					       bidi_length, zero_flag, false);
2399 			if (ret < 0)
2400 				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2401 		}
2402 
2403 		ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2404 				       cmd->data_length, zero_flag, false);
2405 		if (ret < 0)
2406 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2407 	} else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2408 		    cmd->data_length) {
2409 		/*
2410 		 * Special case for COMPARE_AND_WRITE with fabrics
2411 		 * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2412 		 */
2413 		u32 caw_length = cmd->t_task_nolb *
2414 				 cmd->se_dev->dev_attrib.block_size;
2415 
2416 		ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2417 				       &cmd->t_bidi_data_nents,
2418 				       caw_length, zero_flag, false);
2419 		if (ret < 0)
2420 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2421 	}
2422 	/*
2423 	 * If this command is not a write we can execute it right here,
2424 	 * for write buffers we need to notify the fabric driver first
2425 	 * and let it call back once the write buffers are ready.
2426 	 */
2427 	target_add_to_state_list(cmd);
2428 	if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2429 		target_execute_cmd(cmd);
2430 		return 0;
2431 	}
2432 
2433 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2434 	cmd->t_state = TRANSPORT_WRITE_PENDING;
2435 	/*
2436 	 * Determine if frontend context caller is requesting the stopping of
2437 	 * this command for frontend exceptions.
2438 	 */
2439 	if (cmd->transport_state & CMD_T_STOP) {
2440 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
2441 			 __func__, __LINE__, cmd->tag);
2442 
2443 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2444 
2445 		complete_all(&cmd->t_transport_stop_comp);
2446 		return 0;
2447 	}
2448 	cmd->transport_state &= ~CMD_T_ACTIVE;
2449 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2450 
2451 	ret = cmd->se_tfo->write_pending(cmd);
2452 	if (ret == -EAGAIN || ret == -ENOMEM)
2453 		goto queue_full;
2454 
2455 	/* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2456 	WARN_ON(ret);
2457 
2458 	return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2459 
2460 queue_full:
2461 	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2462 	cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2463 	transport_handle_queue_full(cmd, cmd->se_dev);
2464 	return 0;
2465 }
2466 EXPORT_SYMBOL(transport_generic_new_cmd);
2467 
2468 static void transport_write_pending_qf(struct se_cmd *cmd)
2469 {
2470 	int ret;
2471 
2472 	ret = cmd->se_tfo->write_pending(cmd);
2473 	if (ret == -EAGAIN || ret == -ENOMEM) {
2474 		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2475 			 cmd);
2476 		transport_handle_queue_full(cmd, cmd->se_dev);
2477 	}
2478 }
2479 
2480 static bool
2481 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2482 			   unsigned long *flags);
2483 
2484 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2485 {
2486 	unsigned long flags;
2487 
2488 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2489 	__transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2490 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2491 }
2492 
2493 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2494 {
2495 	int ret = 0;
2496 	bool aborted = false, tas = false;
2497 
2498 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2499 		if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2500 			target_wait_free_cmd(cmd, &aborted, &tas);
2501 
2502 		if (!aborted || tas)
2503 			ret = transport_put_cmd(cmd);
2504 	} else {
2505 		if (wait_for_tasks)
2506 			target_wait_free_cmd(cmd, &aborted, &tas);
2507 		/*
2508 		 * Handle WRITE failure case where transport_generic_new_cmd()
2509 		 * has already added se_cmd to state_list, but fabric has
2510 		 * failed command before I/O submission.
2511 		 */
2512 		if (cmd->state_active)
2513 			target_remove_from_state_list(cmd);
2514 
2515 		if (cmd->se_lun)
2516 			transport_lun_remove_cmd(cmd);
2517 
2518 		if (!aborted || tas)
2519 			ret = transport_put_cmd(cmd);
2520 	}
2521 	/*
2522 	 * If the task has been internally aborted due to TMR ABORT_TASK
2523 	 * or LUN_RESET, target_core_tmr.c is responsible for performing
2524 	 * the remaining calls to target_put_sess_cmd(), and not the
2525 	 * callers of this function.
2526 	 */
2527 	if (aborted) {
2528 		pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2529 		wait_for_completion(&cmd->cmd_wait_comp);
2530 		cmd->se_tfo->release_cmd(cmd);
2531 		ret = 1;
2532 	}
2533 	return ret;
2534 }
2535 EXPORT_SYMBOL(transport_generic_free_cmd);
2536 
2537 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2538  * @se_cmd:	command descriptor to add
2539  * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
2540  */
2541 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2542 {
2543 	struct se_session *se_sess = se_cmd->se_sess;
2544 	unsigned long flags;
2545 	int ret = 0;
2546 
2547 	/*
2548 	 * Add a second kref if the fabric caller is expecting to handle
2549 	 * fabric acknowledgement that requires two target_put_sess_cmd()
2550 	 * invocations before se_cmd descriptor release.
2551 	 */
2552 	if (ack_kref) {
2553 		if (!kref_get_unless_zero(&se_cmd->cmd_kref))
2554 			return -EINVAL;
2555 
2556 		se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2557 	}
2558 
2559 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2560 	if (se_sess->sess_tearing_down) {
2561 		ret = -ESHUTDOWN;
2562 		goto out;
2563 	}
2564 	list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2565 out:
2566 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2567 
2568 	if (ret && ack_kref)
2569 		target_put_sess_cmd(se_cmd);
2570 
2571 	return ret;
2572 }
2573 EXPORT_SYMBOL(target_get_sess_cmd);
2574 
2575 static void target_free_cmd_mem(struct se_cmd *cmd)
2576 {
2577 	transport_free_pages(cmd);
2578 
2579 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2580 		core_tmr_release_req(cmd->se_tmr_req);
2581 	if (cmd->t_task_cdb != cmd->__t_task_cdb)
2582 		kfree(cmd->t_task_cdb);
2583 }
2584 
2585 static void target_release_cmd_kref(struct kref *kref)
2586 {
2587 	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2588 	struct se_session *se_sess = se_cmd->se_sess;
2589 	unsigned long flags;
2590 	bool fabric_stop;
2591 
2592 	if (se_sess) {
2593 		spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2594 
2595 		spin_lock(&se_cmd->t_state_lock);
2596 		fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP) &&
2597 			      (se_cmd->transport_state & CMD_T_ABORTED);
2598 		spin_unlock(&se_cmd->t_state_lock);
2599 
2600 		if (se_cmd->cmd_wait_set || fabric_stop) {
2601 			list_del_init(&se_cmd->se_cmd_list);
2602 			spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2603 			target_free_cmd_mem(se_cmd);
2604 			complete(&se_cmd->cmd_wait_comp);
2605 			return;
2606 		}
2607 		list_del_init(&se_cmd->se_cmd_list);
2608 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2609 	}
2610 
2611 	target_free_cmd_mem(se_cmd);
2612 	se_cmd->se_tfo->release_cmd(se_cmd);
2613 }
2614 
2615 /**
2616  * target_put_sess_cmd - decrease the command reference count
2617  * @se_cmd:	command to drop a reference from
2618  *
2619  * Returns 1 if and only if this target_put_sess_cmd() call caused the
2620  * refcount to drop to zero. Returns zero otherwise.
2621  */
2622 int target_put_sess_cmd(struct se_cmd *se_cmd)
2623 {
2624 	return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2625 }
2626 EXPORT_SYMBOL(target_put_sess_cmd);
2627 
2628 /* target_sess_cmd_list_set_waiting - Flag all commands in
2629  *         sess_cmd_list to complete cmd_wait_comp.  Set
2630  *         sess_tearing_down so no more commands are queued.
2631  * @se_sess:	session to flag
2632  */
2633 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2634 {
2635 	struct se_cmd *se_cmd, *tmp_cmd;
2636 	unsigned long flags;
2637 	int rc;
2638 
2639 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2640 	if (se_sess->sess_tearing_down) {
2641 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2642 		return;
2643 	}
2644 	se_sess->sess_tearing_down = 1;
2645 	list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2646 
2647 	list_for_each_entry_safe(se_cmd, tmp_cmd,
2648 				 &se_sess->sess_wait_list, se_cmd_list) {
2649 		rc = kref_get_unless_zero(&se_cmd->cmd_kref);
2650 		if (rc) {
2651 			se_cmd->cmd_wait_set = 1;
2652 			spin_lock(&se_cmd->t_state_lock);
2653 			se_cmd->transport_state |= CMD_T_FABRIC_STOP;
2654 			spin_unlock(&se_cmd->t_state_lock);
2655 		} else
2656 			list_del_init(&se_cmd->se_cmd_list);
2657 	}
2658 
2659 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2660 }
2661 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2662 
2663 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2664  * @se_sess:    session to wait for active I/O
2665  */
2666 void target_wait_for_sess_cmds(struct se_session *se_sess)
2667 {
2668 	struct se_cmd *se_cmd, *tmp_cmd;
2669 	unsigned long flags;
2670 	bool tas;
2671 
2672 	list_for_each_entry_safe(se_cmd, tmp_cmd,
2673 				&se_sess->sess_wait_list, se_cmd_list) {
2674 		pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2675 			" %d\n", se_cmd, se_cmd->t_state,
2676 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2677 
2678 		spin_lock_irqsave(&se_cmd->t_state_lock, flags);
2679 		tas = (se_cmd->transport_state & CMD_T_TAS);
2680 		spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
2681 
2682 		if (!target_put_sess_cmd(se_cmd)) {
2683 			if (tas)
2684 				target_put_sess_cmd(se_cmd);
2685 		}
2686 
2687 		wait_for_completion(&se_cmd->cmd_wait_comp);
2688 		pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2689 			" fabric state: %d\n", se_cmd, se_cmd->t_state,
2690 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2691 
2692 		se_cmd->se_tfo->release_cmd(se_cmd);
2693 	}
2694 
2695 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2696 	WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2697 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2698 
2699 }
2700 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2701 
2702 static void target_lun_confirm(struct percpu_ref *ref)
2703 {
2704 	struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
2705 
2706 	complete(&lun->lun_ref_comp);
2707 }
2708 
2709 void transport_clear_lun_ref(struct se_lun *lun)
2710 {
2711 	/*
2712 	 * Mark the percpu-ref as DEAD, switch to atomic_t mode, drop
2713 	 * the initial reference and schedule confirm kill to be
2714 	 * executed after one full RCU grace period has completed.
2715 	 */
2716 	percpu_ref_kill_and_confirm(&lun->lun_ref, target_lun_confirm);
2717 	/*
2718 	 * The first completion waits for percpu_ref_switch_to_atomic_rcu()
2719 	 * to call target_lun_confirm after lun->lun_ref has been marked
2720 	 * as __PERCPU_REF_DEAD on all CPUs, and switches to atomic_t
2721 	 * mode so that percpu_ref_tryget_live() lookup of lun->lun_ref
2722 	 * fails for all new incoming I/O.
2723 	 */
2724 	wait_for_completion(&lun->lun_ref_comp);
2725 	/*
2726 	 * The second completion waits for percpu_ref_put_many() to
2727 	 * invoke ->release() after lun->lun_ref has switched to
2728 	 * atomic_t mode, and lun->lun_ref.count has reached zero.
2729 	 *
2730 	 * At this point all target-core lun->lun_ref references have
2731 	 * been dropped via transport_lun_remove_cmd(), and it's safe
2732 	 * to proceed with the remaining LUN shutdown.
2733 	 */
2734 	wait_for_completion(&lun->lun_shutdown_comp);
2735 }
2736 
2737 static bool
2738 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2739 			   bool *aborted, bool *tas, unsigned long *flags)
2740 	__releases(&cmd->t_state_lock)
2741 	__acquires(&cmd->t_state_lock)
2742 {
2743 
2744 	assert_spin_locked(&cmd->t_state_lock);
2745 	WARN_ON_ONCE(!irqs_disabled());
2746 
2747 	if (fabric_stop)
2748 		cmd->transport_state |= CMD_T_FABRIC_STOP;
2749 
2750 	if (cmd->transport_state & CMD_T_ABORTED)
2751 		*aborted = true;
2752 
2753 	if (cmd->transport_state & CMD_T_TAS)
2754 		*tas = true;
2755 
2756 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2757 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2758 		return false;
2759 
2760 	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2761 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2762 		return false;
2763 
2764 	if (!(cmd->transport_state & CMD_T_ACTIVE))
2765 		return false;
2766 
2767 	if (fabric_stop && *aborted)
2768 		return false;
2769 
2770 	cmd->transport_state |= CMD_T_STOP;
2771 
2772 	pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08llx i_state: %d,"
2773 		 " t_state: %d, CMD_T_STOP\n", cmd, cmd->tag,
2774 		 cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2775 
2776 	spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
2777 
2778 	wait_for_completion(&cmd->t_transport_stop_comp);
2779 
2780 	spin_lock_irqsave(&cmd->t_state_lock, *flags);
2781 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2782 
2783 	pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
2784 		 "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
2785 
2786 	return true;
2787 }
2788 
2789 /**
2790  * transport_wait_for_tasks - set CMD_T_STOP and wait for t_transport_stop_comp
2791  * @cmd: command to wait on
2792  */
2793 bool transport_wait_for_tasks(struct se_cmd *cmd)
2794 {
2795 	unsigned long flags;
2796 	bool ret, aborted = false, tas = false;
2797 
2798 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2799 	ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
2800 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2801 
2802 	return ret;
2803 }
2804 EXPORT_SYMBOL(transport_wait_for_tasks);
2805 
2806 struct sense_info {
2807 	u8 key;
2808 	u8 asc;
2809 	u8 ascq;
2810 	bool add_sector_info;
2811 };
2812 
2813 static const struct sense_info sense_info_table[] = {
2814 	[TCM_NO_SENSE] = {
2815 		.key = NOT_READY
2816 	},
2817 	[TCM_NON_EXISTENT_LUN] = {
2818 		.key = ILLEGAL_REQUEST,
2819 		.asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
2820 	},
2821 	[TCM_UNSUPPORTED_SCSI_OPCODE] = {
2822 		.key = ILLEGAL_REQUEST,
2823 		.asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2824 	},
2825 	[TCM_SECTOR_COUNT_TOO_MANY] = {
2826 		.key = ILLEGAL_REQUEST,
2827 		.asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2828 	},
2829 	[TCM_UNKNOWN_MODE_PAGE] = {
2830 		.key = ILLEGAL_REQUEST,
2831 		.asc = 0x24, /* INVALID FIELD IN CDB */
2832 	},
2833 	[TCM_CHECK_CONDITION_ABORT_CMD] = {
2834 		.key = ABORTED_COMMAND,
2835 		.asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
2836 		.ascq = 0x03,
2837 	},
2838 	[TCM_INCORRECT_AMOUNT_OF_DATA] = {
2839 		.key = ABORTED_COMMAND,
2840 		.asc = 0x0c, /* WRITE ERROR */
2841 		.ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
2842 	},
2843 	[TCM_INVALID_CDB_FIELD] = {
2844 		.key = ILLEGAL_REQUEST,
2845 		.asc = 0x24, /* INVALID FIELD IN CDB */
2846 	},
2847 	[TCM_INVALID_PARAMETER_LIST] = {
2848 		.key = ILLEGAL_REQUEST,
2849 		.asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
2850 	},
2851 	[TCM_TOO_MANY_TARGET_DESCS] = {
2852 		.key = ILLEGAL_REQUEST,
2853 		.asc = 0x26,
2854 		.ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
2855 	},
2856 	[TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
2857 		.key = ILLEGAL_REQUEST,
2858 		.asc = 0x26,
2859 		.ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
2860 	},
2861 	[TCM_TOO_MANY_SEGMENT_DESCS] = {
2862 		.key = ILLEGAL_REQUEST,
2863 		.asc = 0x26,
2864 		.ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
2865 	},
2866 	[TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
2867 		.key = ILLEGAL_REQUEST,
2868 		.asc = 0x26,
2869 		.ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
2870 	},
2871 	[TCM_PARAMETER_LIST_LENGTH_ERROR] = {
2872 		.key = ILLEGAL_REQUEST,
2873 		.asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
2874 	},
2875 	[TCM_UNEXPECTED_UNSOLICITED_DATA] = {
2876 		.key = ILLEGAL_REQUEST,
2877 		.asc = 0x0c, /* WRITE ERROR */
2878 		.ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
2879 	},
2880 	[TCM_SERVICE_CRC_ERROR] = {
2881 		.key = ABORTED_COMMAND,
2882 		.asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
2883 		.ascq = 0x05, /* N/A */
2884 	},
2885 	[TCM_SNACK_REJECTED] = {
2886 		.key = ABORTED_COMMAND,
2887 		.asc = 0x11, /* READ ERROR */
2888 		.ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
2889 	},
2890 	[TCM_WRITE_PROTECTED] = {
2891 		.key = DATA_PROTECT,
2892 		.asc = 0x27, /* WRITE PROTECTED */
2893 	},
2894 	[TCM_ADDRESS_OUT_OF_RANGE] = {
2895 		.key = ILLEGAL_REQUEST,
2896 		.asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2897 	},
2898 	[TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
2899 		.key = UNIT_ATTENTION,
2900 	},
2901 	[TCM_CHECK_CONDITION_NOT_READY] = {
2902 		.key = NOT_READY,
2903 	},
2904 	[TCM_MISCOMPARE_VERIFY] = {
2905 		.key = MISCOMPARE,
2906 		.asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
2907 		.ascq = 0x00,
2908 	},
2909 	[TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
2910 		.key = ABORTED_COMMAND,
2911 		.asc = 0x10,
2912 		.ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
2913 		.add_sector_info = true,
2914 	},
2915 	[TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
2916 		.key = ABORTED_COMMAND,
2917 		.asc = 0x10,
2918 		.ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2919 		.add_sector_info = true,
2920 	},
2921 	[TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
2922 		.key = ABORTED_COMMAND,
2923 		.asc = 0x10,
2924 		.ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2925 		.add_sector_info = true,
2926 	},
2927 	[TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
2928 		.key = COPY_ABORTED,
2929 		.asc = 0x0d,
2930 		.ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
2931 
2932 	},
2933 	[TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
2934 		/*
2935 		 * Returning ILLEGAL REQUEST would cause immediate IO errors on
2936 		 * Solaris initiators.  Returning NOT READY instead means the
2937 		 * operations will be retried a finite number of times and we
2938 		 * can survive intermittent errors.
2939 		 */
2940 		.key = NOT_READY,
2941 		.asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
2942 	},
2943 };
2944 
2945 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
2946 {
2947 	const struct sense_info *si;
2948 	u8 *buffer = cmd->sense_buffer;
2949 	int r = (__force int)reason;
2950 	u8 asc, ascq;
2951 	bool desc_format = target_sense_desc_format(cmd->se_dev);
2952 
2953 	if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
2954 		si = &sense_info_table[r];
2955 	else
2956 		si = &sense_info_table[(__force int)
2957 				       TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
2958 
2959 	if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
2960 		core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2961 		WARN_ON_ONCE(asc == 0);
2962 	} else if (si->asc == 0) {
2963 		WARN_ON_ONCE(cmd->scsi_asc == 0);
2964 		asc = cmd->scsi_asc;
2965 		ascq = cmd->scsi_ascq;
2966 	} else {
2967 		asc = si->asc;
2968 		ascq = si->ascq;
2969 	}
2970 
2971 	scsi_build_sense_buffer(desc_format, buffer, si->key, asc, ascq);
2972 	if (si->add_sector_info)
2973 		return scsi_set_sense_information(buffer,
2974 						  cmd->scsi_sense_length,
2975 						  cmd->bad_sector);
2976 
2977 	return 0;
2978 }
2979 
2980 int
2981 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2982 		sense_reason_t reason, int from_transport)
2983 {
2984 	unsigned long flags;
2985 
2986 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2987 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2988 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2989 		return 0;
2990 	}
2991 	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2992 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2993 
2994 	if (!from_transport) {
2995 		int rc;
2996 
2997 		cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2998 		cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2999 		cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
3000 		rc = translate_sense_reason(cmd, reason);
3001 		if (rc)
3002 			return rc;
3003 	}
3004 
3005 	trace_target_cmd_complete(cmd);
3006 	return cmd->se_tfo->queue_status(cmd);
3007 }
3008 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3009 
3010 static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3011 	__releases(&cmd->t_state_lock)
3012 	__acquires(&cmd->t_state_lock)
3013 {
3014 	assert_spin_locked(&cmd->t_state_lock);
3015 	WARN_ON_ONCE(!irqs_disabled());
3016 
3017 	if (!(cmd->transport_state & CMD_T_ABORTED))
3018 		return 0;
3019 	/*
3020 	 * If cmd has been aborted but either no status is to be sent or it has
3021 	 * already been sent, just return
3022 	 */
3023 	if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS)) {
3024 		if (send_status)
3025 			cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3026 		return 1;
3027 	}
3028 
3029 	pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB:"
3030 		" 0x%02x ITT: 0x%08llx\n", cmd->t_task_cdb[0], cmd->tag);
3031 
3032 	cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
3033 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3034 	trace_target_cmd_complete(cmd);
3035 
3036 	spin_unlock_irq(&cmd->t_state_lock);
3037 	cmd->se_tfo->queue_status(cmd);
3038 	spin_lock_irq(&cmd->t_state_lock);
3039 
3040 	return 1;
3041 }
3042 
3043 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3044 {
3045 	int ret;
3046 
3047 	spin_lock_irq(&cmd->t_state_lock);
3048 	ret = __transport_check_aborted_status(cmd, send_status);
3049 	spin_unlock_irq(&cmd->t_state_lock);
3050 
3051 	return ret;
3052 }
3053 EXPORT_SYMBOL(transport_check_aborted_status);
3054 
3055 void transport_send_task_abort(struct se_cmd *cmd)
3056 {
3057 	unsigned long flags;
3058 
3059 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3060 	if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
3061 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3062 		return;
3063 	}
3064 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3065 
3066 	/*
3067 	 * If there are still expected incoming fabric WRITEs, we wait
3068 	 * until until they have completed before sending a TASK_ABORTED
3069 	 * response.  This response with TASK_ABORTED status will be
3070 	 * queued back to fabric module by transport_check_aborted_status().
3071 	 */
3072 	if (cmd->data_direction == DMA_TO_DEVICE) {
3073 		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3074 			spin_lock_irqsave(&cmd->t_state_lock, flags);
3075 			if (cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS) {
3076 				spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3077 				goto send_abort;
3078 			}
3079 			cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3080 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3081 			return;
3082 		}
3083 	}
3084 send_abort:
3085 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3086 
3087 	transport_lun_remove_cmd(cmd);
3088 
3089 	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
3090 		 cmd->t_task_cdb[0], cmd->tag);
3091 
3092 	trace_target_cmd_complete(cmd);
3093 	cmd->se_tfo->queue_status(cmd);
3094 }
3095 
3096 static void target_tmr_work(struct work_struct *work)
3097 {
3098 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3099 	struct se_device *dev = cmd->se_dev;
3100 	struct se_tmr_req *tmr = cmd->se_tmr_req;
3101 	unsigned long flags;
3102 	int ret;
3103 
3104 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3105 	if (cmd->transport_state & CMD_T_ABORTED) {
3106 		tmr->response = TMR_FUNCTION_REJECTED;
3107 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3108 		goto check_stop;
3109 	}
3110 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3111 
3112 	switch (tmr->function) {
3113 	case TMR_ABORT_TASK:
3114 		core_tmr_abort_task(dev, tmr, cmd->se_sess);
3115 		break;
3116 	case TMR_ABORT_TASK_SET:
3117 	case TMR_CLEAR_ACA:
3118 	case TMR_CLEAR_TASK_SET:
3119 		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3120 		break;
3121 	case TMR_LUN_RESET:
3122 		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3123 		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3124 					 TMR_FUNCTION_REJECTED;
3125 		if (tmr->response == TMR_FUNCTION_COMPLETE) {
3126 			target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3127 					       cmd->orig_fe_lun, 0x29,
3128 					       ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3129 		}
3130 		break;
3131 	case TMR_TARGET_WARM_RESET:
3132 		tmr->response = TMR_FUNCTION_REJECTED;
3133 		break;
3134 	case TMR_TARGET_COLD_RESET:
3135 		tmr->response = TMR_FUNCTION_REJECTED;
3136 		break;
3137 	default:
3138 		pr_err("Uknown TMR function: 0x%02x.\n",
3139 				tmr->function);
3140 		tmr->response = TMR_FUNCTION_REJECTED;
3141 		break;
3142 	}
3143 
3144 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3145 	if (cmd->transport_state & CMD_T_ABORTED) {
3146 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3147 		goto check_stop;
3148 	}
3149 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3150 
3151 	cmd->se_tfo->queue_tm_rsp(cmd);
3152 
3153 check_stop:
3154 	transport_cmd_check_stop_to_fabric(cmd);
3155 }
3156 
3157 int transport_generic_handle_tmr(
3158 	struct se_cmd *cmd)
3159 {
3160 	unsigned long flags;
3161 	bool aborted = false;
3162 
3163 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3164 	if (cmd->transport_state & CMD_T_ABORTED) {
3165 		aborted = true;
3166 	} else {
3167 		cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3168 		cmd->transport_state |= CMD_T_ACTIVE;
3169 	}
3170 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3171 
3172 	if (aborted) {
3173 		pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d"
3174 			"ref_tag: %llu tag: %llu\n", cmd->se_tmr_req->function,
3175 			cmd->se_tmr_req->ref_task_tag, cmd->tag);
3176 		transport_cmd_check_stop_to_fabric(cmd);
3177 		return 0;
3178 	}
3179 
3180 	INIT_WORK(&cmd->work, target_tmr_work);
3181 	queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3182 	return 0;
3183 }
3184 EXPORT_SYMBOL(transport_generic_handle_tmr);
3185 
3186 bool
3187 target_check_wce(struct se_device *dev)
3188 {
3189 	bool wce = false;
3190 
3191 	if (dev->transport->get_write_cache)
3192 		wce = dev->transport->get_write_cache(dev);
3193 	else if (dev->dev_attrib.emulate_write_cache > 0)
3194 		wce = true;
3195 
3196 	return wce;
3197 }
3198 
3199 bool
3200 target_check_fua(struct se_device *dev)
3201 {
3202 	return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3203 }
3204