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 
461 	complete(&nacl->acl_free_comp);
462 }
463 
464 void target_put_nacl(struct se_node_acl *nacl)
465 {
466 	kref_put(&nacl->acl_kref, target_complete_nacl);
467 }
468 EXPORT_SYMBOL(target_put_nacl);
469 
470 void transport_deregister_session_configfs(struct se_session *se_sess)
471 {
472 	struct se_node_acl *se_nacl;
473 	unsigned long flags;
474 	/*
475 	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
476 	 */
477 	se_nacl = se_sess->se_node_acl;
478 	if (se_nacl) {
479 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
480 		if (!list_empty(&se_sess->sess_acl_list))
481 			list_del_init(&se_sess->sess_acl_list);
482 		/*
483 		 * If the session list is empty, then clear the pointer.
484 		 * Otherwise, set the struct se_session pointer from the tail
485 		 * element of the per struct se_node_acl active session list.
486 		 */
487 		if (list_empty(&se_nacl->acl_sess_list))
488 			se_nacl->nacl_sess = NULL;
489 		else {
490 			se_nacl->nacl_sess = container_of(
491 					se_nacl->acl_sess_list.prev,
492 					struct se_session, sess_acl_list);
493 		}
494 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
495 	}
496 }
497 EXPORT_SYMBOL(transport_deregister_session_configfs);
498 
499 void transport_free_session(struct se_session *se_sess)
500 {
501 	struct se_node_acl *se_nacl = se_sess->se_node_acl;
502 	/*
503 	 * Drop the se_node_acl->nacl_kref obtained from within
504 	 * core_tpg_get_initiator_node_acl().
505 	 */
506 	if (se_nacl) {
507 		se_sess->se_node_acl = NULL;
508 		target_put_nacl(se_nacl);
509 	}
510 	if (se_sess->sess_cmd_map) {
511 		percpu_ida_destroy(&se_sess->sess_tag_pool);
512 		kvfree(se_sess->sess_cmd_map);
513 	}
514 	kmem_cache_free(se_sess_cache, se_sess);
515 }
516 EXPORT_SYMBOL(transport_free_session);
517 
518 void transport_deregister_session(struct se_session *se_sess)
519 {
520 	struct se_portal_group *se_tpg = se_sess->se_tpg;
521 	const struct target_core_fabric_ops *se_tfo;
522 	struct se_node_acl *se_nacl;
523 	unsigned long flags;
524 	bool drop_nacl = false;
525 
526 	if (!se_tpg) {
527 		transport_free_session(se_sess);
528 		return;
529 	}
530 	se_tfo = se_tpg->se_tpg_tfo;
531 
532 	spin_lock_irqsave(&se_tpg->session_lock, flags);
533 	list_del(&se_sess->sess_list);
534 	se_sess->se_tpg = NULL;
535 	se_sess->fabric_sess_ptr = NULL;
536 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
537 
538 	/*
539 	 * Determine if we need to do extra work for this initiator node's
540 	 * struct se_node_acl if it had been previously dynamically generated.
541 	 */
542 	se_nacl = se_sess->se_node_acl;
543 
544 	mutex_lock(&se_tpg->acl_node_mutex);
545 	if (se_nacl && se_nacl->dynamic_node_acl) {
546 		if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
547 			list_del(&se_nacl->acl_list);
548 			drop_nacl = true;
549 		}
550 	}
551 	mutex_unlock(&se_tpg->acl_node_mutex);
552 
553 	if (drop_nacl) {
554 		core_tpg_wait_for_nacl_pr_ref(se_nacl);
555 		core_free_device_list_for_node(se_nacl, se_tpg);
556 		se_sess->se_node_acl = NULL;
557 		kfree(se_nacl);
558 	}
559 	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
560 		se_tpg->se_tpg_tfo->get_fabric_name());
561 	/*
562 	 * If last kref is dropping now for an explicit NodeACL, awake sleeping
563 	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
564 	 * removal context from within transport_free_session() code.
565 	 */
566 
567 	transport_free_session(se_sess);
568 }
569 EXPORT_SYMBOL(transport_deregister_session);
570 
571 static void target_remove_from_state_list(struct se_cmd *cmd)
572 {
573 	struct se_device *dev = cmd->se_dev;
574 	unsigned long flags;
575 
576 	if (!dev)
577 		return;
578 
579 	if (cmd->transport_state & CMD_T_BUSY)
580 		return;
581 
582 	spin_lock_irqsave(&dev->execute_task_lock, flags);
583 	if (cmd->state_active) {
584 		list_del(&cmd->state_list);
585 		cmd->state_active = false;
586 	}
587 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
588 }
589 
590 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
591 				    bool write_pending)
592 {
593 	unsigned long flags;
594 
595 	if (remove_from_lists) {
596 		target_remove_from_state_list(cmd);
597 
598 		/*
599 		 * Clear struct se_cmd->se_lun before the handoff to FE.
600 		 */
601 		cmd->se_lun = NULL;
602 	}
603 
604 	spin_lock_irqsave(&cmd->t_state_lock, flags);
605 	if (write_pending)
606 		cmd->t_state = TRANSPORT_WRITE_PENDING;
607 
608 	/*
609 	 * Determine if frontend context caller is requesting the stopping of
610 	 * this command for frontend exceptions.
611 	 */
612 	if (cmd->transport_state & CMD_T_STOP) {
613 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
614 			__func__, __LINE__, cmd->tag);
615 
616 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
617 
618 		complete_all(&cmd->t_transport_stop_comp);
619 		return 1;
620 	}
621 
622 	cmd->transport_state &= ~CMD_T_ACTIVE;
623 	if (remove_from_lists) {
624 		/*
625 		 * Some fabric modules like tcm_loop can release
626 		 * their internally allocated I/O reference now and
627 		 * struct se_cmd now.
628 		 *
629 		 * Fabric modules are expected to return '1' here if the
630 		 * se_cmd being passed is released at this point,
631 		 * or zero if not being released.
632 		 */
633 		if (cmd->se_tfo->check_stop_free != NULL) {
634 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
635 			return cmd->se_tfo->check_stop_free(cmd);
636 		}
637 	}
638 
639 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
640 	return 0;
641 }
642 
643 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
644 {
645 	return transport_cmd_check_stop(cmd, true, false);
646 }
647 
648 static void transport_lun_remove_cmd(struct se_cmd *cmd)
649 {
650 	struct se_lun *lun = cmd->se_lun;
651 
652 	if (!lun)
653 		return;
654 
655 	if (cmpxchg(&cmd->lun_ref_active, true, false))
656 		percpu_ref_put(&lun->lun_ref);
657 }
658 
659 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
660 {
661 	bool ack_kref = (cmd->se_cmd_flags & SCF_ACK_KREF);
662 
663 	if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
664 		transport_lun_remove_cmd(cmd);
665 	/*
666 	 * Allow the fabric driver to unmap any resources before
667 	 * releasing the descriptor via TFO->release_cmd()
668 	 */
669 	if (remove)
670 		cmd->se_tfo->aborted_task(cmd);
671 
672 	if (transport_cmd_check_stop_to_fabric(cmd))
673 		return;
674 	if (remove && ack_kref)
675 		transport_put_cmd(cmd);
676 }
677 
678 static void target_complete_failure_work(struct work_struct *work)
679 {
680 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
681 
682 	transport_generic_request_failure(cmd,
683 			TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
684 }
685 
686 /*
687  * Used when asking transport to copy Sense Data from the underlying
688  * Linux/SCSI struct scsi_cmnd
689  */
690 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
691 {
692 	struct se_device *dev = cmd->se_dev;
693 
694 	WARN_ON(!cmd->se_lun);
695 
696 	if (!dev)
697 		return NULL;
698 
699 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
700 		return NULL;
701 
702 	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
703 
704 	pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
705 		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
706 	return cmd->sense_buffer;
707 }
708 
709 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
710 {
711 	struct se_device *dev = cmd->se_dev;
712 	int success = scsi_status == GOOD;
713 	unsigned long flags;
714 
715 	cmd->scsi_status = scsi_status;
716 
717 
718 	spin_lock_irqsave(&cmd->t_state_lock, flags);
719 	cmd->transport_state &= ~CMD_T_BUSY;
720 
721 	if (dev && dev->transport->transport_complete) {
722 		dev->transport->transport_complete(cmd,
723 				cmd->t_data_sg,
724 				transport_get_sense_buffer(cmd));
725 		if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
726 			success = 1;
727 	}
728 
729 	/*
730 	 * Check for case where an explicit ABORT_TASK has been received
731 	 * and transport_wait_for_tasks() will be waiting for completion..
732 	 */
733 	if (cmd->transport_state & CMD_T_ABORTED ||
734 	    cmd->transport_state & CMD_T_STOP) {
735 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
736 		complete_all(&cmd->t_transport_stop_comp);
737 		return;
738 	} else if (!success) {
739 		INIT_WORK(&cmd->work, target_complete_failure_work);
740 	} else {
741 		INIT_WORK(&cmd->work, target_complete_ok_work);
742 	}
743 
744 	cmd->t_state = TRANSPORT_COMPLETE;
745 	cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
746 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
747 
748 	if (cmd->se_cmd_flags & SCF_USE_CPUID)
749 		queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
750 	else
751 		queue_work(target_completion_wq, &cmd->work);
752 }
753 EXPORT_SYMBOL(target_complete_cmd);
754 
755 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
756 {
757 	if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
758 		if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
759 			cmd->residual_count += cmd->data_length - length;
760 		} else {
761 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
762 			cmd->residual_count = cmd->data_length - length;
763 		}
764 
765 		cmd->data_length = length;
766 	}
767 
768 	target_complete_cmd(cmd, scsi_status);
769 }
770 EXPORT_SYMBOL(target_complete_cmd_with_length);
771 
772 static void target_add_to_state_list(struct se_cmd *cmd)
773 {
774 	struct se_device *dev = cmd->se_dev;
775 	unsigned long flags;
776 
777 	spin_lock_irqsave(&dev->execute_task_lock, flags);
778 	if (!cmd->state_active) {
779 		list_add_tail(&cmd->state_list, &dev->state_list);
780 		cmd->state_active = true;
781 	}
782 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
783 }
784 
785 /*
786  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
787  */
788 static void transport_write_pending_qf(struct se_cmd *cmd);
789 static void transport_complete_qf(struct se_cmd *cmd);
790 
791 void target_qf_do_work(struct work_struct *work)
792 {
793 	struct se_device *dev = container_of(work, struct se_device,
794 					qf_work_queue);
795 	LIST_HEAD(qf_cmd_list);
796 	struct se_cmd *cmd, *cmd_tmp;
797 
798 	spin_lock_irq(&dev->qf_cmd_lock);
799 	list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
800 	spin_unlock_irq(&dev->qf_cmd_lock);
801 
802 	list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
803 		list_del(&cmd->se_qf_node);
804 		atomic_dec_mb(&dev->dev_qf_count);
805 
806 		pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
807 			" context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
808 			(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
809 			(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
810 			: "UNKNOWN");
811 
812 		if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
813 			transport_write_pending_qf(cmd);
814 		else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
815 			transport_complete_qf(cmd);
816 	}
817 }
818 
819 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
820 {
821 	switch (cmd->data_direction) {
822 	case DMA_NONE:
823 		return "NONE";
824 	case DMA_FROM_DEVICE:
825 		return "READ";
826 	case DMA_TO_DEVICE:
827 		return "WRITE";
828 	case DMA_BIDIRECTIONAL:
829 		return "BIDI";
830 	default:
831 		break;
832 	}
833 
834 	return "UNKNOWN";
835 }
836 
837 void transport_dump_dev_state(
838 	struct se_device *dev,
839 	char *b,
840 	int *bl)
841 {
842 	*bl += sprintf(b + *bl, "Status: ");
843 	if (dev->export_count)
844 		*bl += sprintf(b + *bl, "ACTIVATED");
845 	else
846 		*bl += sprintf(b + *bl, "DEACTIVATED");
847 
848 	*bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
849 	*bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
850 		dev->dev_attrib.block_size,
851 		dev->dev_attrib.hw_max_sectors);
852 	*bl += sprintf(b + *bl, "        ");
853 }
854 
855 void transport_dump_vpd_proto_id(
856 	struct t10_vpd *vpd,
857 	unsigned char *p_buf,
858 	int p_buf_len)
859 {
860 	unsigned char buf[VPD_TMP_BUF_SIZE];
861 	int len;
862 
863 	memset(buf, 0, VPD_TMP_BUF_SIZE);
864 	len = sprintf(buf, "T10 VPD Protocol Identifier: ");
865 
866 	switch (vpd->protocol_identifier) {
867 	case 0x00:
868 		sprintf(buf+len, "Fibre Channel\n");
869 		break;
870 	case 0x10:
871 		sprintf(buf+len, "Parallel SCSI\n");
872 		break;
873 	case 0x20:
874 		sprintf(buf+len, "SSA\n");
875 		break;
876 	case 0x30:
877 		sprintf(buf+len, "IEEE 1394\n");
878 		break;
879 	case 0x40:
880 		sprintf(buf+len, "SCSI Remote Direct Memory Access"
881 				" Protocol\n");
882 		break;
883 	case 0x50:
884 		sprintf(buf+len, "Internet SCSI (iSCSI)\n");
885 		break;
886 	case 0x60:
887 		sprintf(buf+len, "SAS Serial SCSI Protocol\n");
888 		break;
889 	case 0x70:
890 		sprintf(buf+len, "Automation/Drive Interface Transport"
891 				" Protocol\n");
892 		break;
893 	case 0x80:
894 		sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
895 		break;
896 	default:
897 		sprintf(buf+len, "Unknown 0x%02x\n",
898 				vpd->protocol_identifier);
899 		break;
900 	}
901 
902 	if (p_buf)
903 		strncpy(p_buf, buf, p_buf_len);
904 	else
905 		pr_debug("%s", buf);
906 }
907 
908 void
909 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
910 {
911 	/*
912 	 * Check if the Protocol Identifier Valid (PIV) bit is set..
913 	 *
914 	 * from spc3r23.pdf section 7.5.1
915 	 */
916 	 if (page_83[1] & 0x80) {
917 		vpd->protocol_identifier = (page_83[0] & 0xf0);
918 		vpd->protocol_identifier_set = 1;
919 		transport_dump_vpd_proto_id(vpd, NULL, 0);
920 	}
921 }
922 EXPORT_SYMBOL(transport_set_vpd_proto_id);
923 
924 int transport_dump_vpd_assoc(
925 	struct t10_vpd *vpd,
926 	unsigned char *p_buf,
927 	int p_buf_len)
928 {
929 	unsigned char buf[VPD_TMP_BUF_SIZE];
930 	int ret = 0;
931 	int len;
932 
933 	memset(buf, 0, VPD_TMP_BUF_SIZE);
934 	len = sprintf(buf, "T10 VPD Identifier Association: ");
935 
936 	switch (vpd->association) {
937 	case 0x00:
938 		sprintf(buf+len, "addressed logical unit\n");
939 		break;
940 	case 0x10:
941 		sprintf(buf+len, "target port\n");
942 		break;
943 	case 0x20:
944 		sprintf(buf+len, "SCSI target device\n");
945 		break;
946 	default:
947 		sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
948 		ret = -EINVAL;
949 		break;
950 	}
951 
952 	if (p_buf)
953 		strncpy(p_buf, buf, p_buf_len);
954 	else
955 		pr_debug("%s", buf);
956 
957 	return ret;
958 }
959 
960 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
961 {
962 	/*
963 	 * The VPD identification association..
964 	 *
965 	 * from spc3r23.pdf Section 7.6.3.1 Table 297
966 	 */
967 	vpd->association = (page_83[1] & 0x30);
968 	return transport_dump_vpd_assoc(vpd, NULL, 0);
969 }
970 EXPORT_SYMBOL(transport_set_vpd_assoc);
971 
972 int transport_dump_vpd_ident_type(
973 	struct t10_vpd *vpd,
974 	unsigned char *p_buf,
975 	int p_buf_len)
976 {
977 	unsigned char buf[VPD_TMP_BUF_SIZE];
978 	int ret = 0;
979 	int len;
980 
981 	memset(buf, 0, VPD_TMP_BUF_SIZE);
982 	len = sprintf(buf, "T10 VPD Identifier Type: ");
983 
984 	switch (vpd->device_identifier_type) {
985 	case 0x00:
986 		sprintf(buf+len, "Vendor specific\n");
987 		break;
988 	case 0x01:
989 		sprintf(buf+len, "T10 Vendor ID based\n");
990 		break;
991 	case 0x02:
992 		sprintf(buf+len, "EUI-64 based\n");
993 		break;
994 	case 0x03:
995 		sprintf(buf+len, "NAA\n");
996 		break;
997 	case 0x04:
998 		sprintf(buf+len, "Relative target port identifier\n");
999 		break;
1000 	case 0x08:
1001 		sprintf(buf+len, "SCSI name string\n");
1002 		break;
1003 	default:
1004 		sprintf(buf+len, "Unsupported: 0x%02x\n",
1005 				vpd->device_identifier_type);
1006 		ret = -EINVAL;
1007 		break;
1008 	}
1009 
1010 	if (p_buf) {
1011 		if (p_buf_len < strlen(buf)+1)
1012 			return -EINVAL;
1013 		strncpy(p_buf, buf, p_buf_len);
1014 	} else {
1015 		pr_debug("%s", buf);
1016 	}
1017 
1018 	return ret;
1019 }
1020 
1021 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1022 {
1023 	/*
1024 	 * The VPD identifier type..
1025 	 *
1026 	 * from spc3r23.pdf Section 7.6.3.1 Table 298
1027 	 */
1028 	vpd->device_identifier_type = (page_83[1] & 0x0f);
1029 	return transport_dump_vpd_ident_type(vpd, NULL, 0);
1030 }
1031 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1032 
1033 int transport_dump_vpd_ident(
1034 	struct t10_vpd *vpd,
1035 	unsigned char *p_buf,
1036 	int p_buf_len)
1037 {
1038 	unsigned char buf[VPD_TMP_BUF_SIZE];
1039 	int ret = 0;
1040 
1041 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1042 
1043 	switch (vpd->device_identifier_code_set) {
1044 	case 0x01: /* Binary */
1045 		snprintf(buf, sizeof(buf),
1046 			"T10 VPD Binary Device Identifier: %s\n",
1047 			&vpd->device_identifier[0]);
1048 		break;
1049 	case 0x02: /* ASCII */
1050 		snprintf(buf, sizeof(buf),
1051 			"T10 VPD ASCII Device Identifier: %s\n",
1052 			&vpd->device_identifier[0]);
1053 		break;
1054 	case 0x03: /* UTF-8 */
1055 		snprintf(buf, sizeof(buf),
1056 			"T10 VPD UTF-8 Device Identifier: %s\n",
1057 			&vpd->device_identifier[0]);
1058 		break;
1059 	default:
1060 		sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1061 			" 0x%02x", vpd->device_identifier_code_set);
1062 		ret = -EINVAL;
1063 		break;
1064 	}
1065 
1066 	if (p_buf)
1067 		strncpy(p_buf, buf, p_buf_len);
1068 	else
1069 		pr_debug("%s", buf);
1070 
1071 	return ret;
1072 }
1073 
1074 int
1075 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1076 {
1077 	static const char hex_str[] = "0123456789abcdef";
1078 	int j = 0, i = 4; /* offset to start of the identifier */
1079 
1080 	/*
1081 	 * The VPD Code Set (encoding)
1082 	 *
1083 	 * from spc3r23.pdf Section 7.6.3.1 Table 296
1084 	 */
1085 	vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1086 	switch (vpd->device_identifier_code_set) {
1087 	case 0x01: /* Binary */
1088 		vpd->device_identifier[j++] =
1089 				hex_str[vpd->device_identifier_type];
1090 		while (i < (4 + page_83[3])) {
1091 			vpd->device_identifier[j++] =
1092 				hex_str[(page_83[i] & 0xf0) >> 4];
1093 			vpd->device_identifier[j++] =
1094 				hex_str[page_83[i] & 0x0f];
1095 			i++;
1096 		}
1097 		break;
1098 	case 0x02: /* ASCII */
1099 	case 0x03: /* UTF-8 */
1100 		while (i < (4 + page_83[3]))
1101 			vpd->device_identifier[j++] = page_83[i++];
1102 		break;
1103 	default:
1104 		break;
1105 	}
1106 
1107 	return transport_dump_vpd_ident(vpd, NULL, 0);
1108 }
1109 EXPORT_SYMBOL(transport_set_vpd_ident);
1110 
1111 static sense_reason_t
1112 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1113 			       unsigned int size)
1114 {
1115 	u32 mtl;
1116 
1117 	if (!cmd->se_tfo->max_data_sg_nents)
1118 		return TCM_NO_SENSE;
1119 	/*
1120 	 * Check if fabric enforced maximum SGL entries per I/O descriptor
1121 	 * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1122 	 * residual_count and reduce original cmd->data_length to maximum
1123 	 * length based on single PAGE_SIZE entry scatter-lists.
1124 	 */
1125 	mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1126 	if (cmd->data_length > mtl) {
1127 		/*
1128 		 * If an existing CDB overflow is present, calculate new residual
1129 		 * based on CDB size minus fabric maximum transfer length.
1130 		 *
1131 		 * If an existing CDB underflow is present, calculate new residual
1132 		 * based on original cmd->data_length minus fabric maximum transfer
1133 		 * length.
1134 		 *
1135 		 * Otherwise, set the underflow residual based on cmd->data_length
1136 		 * minus fabric maximum transfer length.
1137 		 */
1138 		if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1139 			cmd->residual_count = (size - mtl);
1140 		} else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1141 			u32 orig_dl = size + cmd->residual_count;
1142 			cmd->residual_count = (orig_dl - mtl);
1143 		} else {
1144 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1145 			cmd->residual_count = (cmd->data_length - mtl);
1146 		}
1147 		cmd->data_length = mtl;
1148 		/*
1149 		 * Reset sbc_check_prot() calculated protection payload
1150 		 * length based upon the new smaller MTL.
1151 		 */
1152 		if (cmd->prot_length) {
1153 			u32 sectors = (mtl / dev->dev_attrib.block_size);
1154 			cmd->prot_length = dev->prot_length * sectors;
1155 		}
1156 	}
1157 	return TCM_NO_SENSE;
1158 }
1159 
1160 sense_reason_t
1161 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1162 {
1163 	struct se_device *dev = cmd->se_dev;
1164 
1165 	if (cmd->unknown_data_length) {
1166 		cmd->data_length = size;
1167 	} else if (size != cmd->data_length) {
1168 		pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1169 			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
1170 			" 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1171 				cmd->data_length, size, cmd->t_task_cdb[0]);
1172 
1173 		if (cmd->data_direction == DMA_TO_DEVICE &&
1174 		    cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1175 			pr_err("Rejecting underflow/overflow WRITE data\n");
1176 			return TCM_INVALID_CDB_FIELD;
1177 		}
1178 		/*
1179 		 * Reject READ_* or WRITE_* with overflow/underflow for
1180 		 * type SCF_SCSI_DATA_CDB.
1181 		 */
1182 		if (dev->dev_attrib.block_size != 512)  {
1183 			pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1184 				" CDB on non 512-byte sector setup subsystem"
1185 				" plugin: %s\n", dev->transport->name);
1186 			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1187 			return TCM_INVALID_CDB_FIELD;
1188 		}
1189 		/*
1190 		 * For the overflow case keep the existing fabric provided
1191 		 * ->data_length.  Otherwise for the underflow case, reset
1192 		 * ->data_length to the smaller SCSI expected data transfer
1193 		 * length.
1194 		 */
1195 		if (size > cmd->data_length) {
1196 			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1197 			cmd->residual_count = (size - cmd->data_length);
1198 		} else {
1199 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1200 			cmd->residual_count = (cmd->data_length - size);
1201 			cmd->data_length = size;
1202 		}
1203 	}
1204 
1205 	return target_check_max_data_sg_nents(cmd, dev, size);
1206 
1207 }
1208 
1209 /*
1210  * Used by fabric modules containing a local struct se_cmd within their
1211  * fabric dependent per I/O descriptor.
1212  *
1213  * Preserves the value of @cmd->tag.
1214  */
1215 void transport_init_se_cmd(
1216 	struct se_cmd *cmd,
1217 	const struct target_core_fabric_ops *tfo,
1218 	struct se_session *se_sess,
1219 	u32 data_length,
1220 	int data_direction,
1221 	int task_attr,
1222 	unsigned char *sense_buffer)
1223 {
1224 	INIT_LIST_HEAD(&cmd->se_delayed_node);
1225 	INIT_LIST_HEAD(&cmd->se_qf_node);
1226 	INIT_LIST_HEAD(&cmd->se_cmd_list);
1227 	INIT_LIST_HEAD(&cmd->state_list);
1228 	init_completion(&cmd->t_transport_stop_comp);
1229 	init_completion(&cmd->cmd_wait_comp);
1230 	spin_lock_init(&cmd->t_state_lock);
1231 	kref_init(&cmd->cmd_kref);
1232 	cmd->transport_state = CMD_T_DEV_ACTIVE;
1233 
1234 	cmd->se_tfo = tfo;
1235 	cmd->se_sess = se_sess;
1236 	cmd->data_length = data_length;
1237 	cmd->data_direction = data_direction;
1238 	cmd->sam_task_attr = task_attr;
1239 	cmd->sense_buffer = sense_buffer;
1240 
1241 	cmd->state_active = false;
1242 }
1243 EXPORT_SYMBOL(transport_init_se_cmd);
1244 
1245 static sense_reason_t
1246 transport_check_alloc_task_attr(struct se_cmd *cmd)
1247 {
1248 	struct se_device *dev = cmd->se_dev;
1249 
1250 	/*
1251 	 * Check if SAM Task Attribute emulation is enabled for this
1252 	 * struct se_device storage object
1253 	 */
1254 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1255 		return 0;
1256 
1257 	if (cmd->sam_task_attr == TCM_ACA_TAG) {
1258 		pr_debug("SAM Task Attribute ACA"
1259 			" emulation is not supported\n");
1260 		return TCM_INVALID_CDB_FIELD;
1261 	}
1262 
1263 	return 0;
1264 }
1265 
1266 sense_reason_t
1267 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1268 {
1269 	struct se_device *dev = cmd->se_dev;
1270 	sense_reason_t ret;
1271 
1272 	/*
1273 	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1274 	 * for VARIABLE_LENGTH_CMD
1275 	 */
1276 	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1277 		pr_err("Received SCSI CDB with command_size: %d that"
1278 			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1279 			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1280 		return TCM_INVALID_CDB_FIELD;
1281 	}
1282 	/*
1283 	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1284 	 * allocate the additional extended CDB buffer now..  Otherwise
1285 	 * setup the pointer from __t_task_cdb to t_task_cdb.
1286 	 */
1287 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1288 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1289 						GFP_KERNEL);
1290 		if (!cmd->t_task_cdb) {
1291 			pr_err("Unable to allocate cmd->t_task_cdb"
1292 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1293 				scsi_command_size(cdb),
1294 				(unsigned long)sizeof(cmd->__t_task_cdb));
1295 			return TCM_OUT_OF_RESOURCES;
1296 		}
1297 	} else
1298 		cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1299 	/*
1300 	 * Copy the original CDB into cmd->
1301 	 */
1302 	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1303 
1304 	trace_target_sequencer_start(cmd);
1305 
1306 	ret = dev->transport->parse_cdb(cmd);
1307 	if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1308 		pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1309 				    cmd->se_tfo->get_fabric_name(),
1310 				    cmd->se_sess->se_node_acl->initiatorname,
1311 				    cmd->t_task_cdb[0]);
1312 	if (ret)
1313 		return ret;
1314 
1315 	ret = transport_check_alloc_task_attr(cmd);
1316 	if (ret)
1317 		return ret;
1318 
1319 	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1320 	atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1321 	return 0;
1322 }
1323 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1324 
1325 /*
1326  * Used by fabric module frontends to queue tasks directly.
1327  * May only be used from process context.
1328  */
1329 int transport_handle_cdb_direct(
1330 	struct se_cmd *cmd)
1331 {
1332 	sense_reason_t ret;
1333 
1334 	if (!cmd->se_lun) {
1335 		dump_stack();
1336 		pr_err("cmd->se_lun is NULL\n");
1337 		return -EINVAL;
1338 	}
1339 	if (in_interrupt()) {
1340 		dump_stack();
1341 		pr_err("transport_generic_handle_cdb cannot be called"
1342 				" from interrupt context\n");
1343 		return -EINVAL;
1344 	}
1345 	/*
1346 	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1347 	 * outstanding descriptors are handled correctly during shutdown via
1348 	 * transport_wait_for_tasks()
1349 	 *
1350 	 * Also, we don't take cmd->t_state_lock here as we only expect
1351 	 * this to be called for initial descriptor submission.
1352 	 */
1353 	cmd->t_state = TRANSPORT_NEW_CMD;
1354 	cmd->transport_state |= CMD_T_ACTIVE;
1355 
1356 	/*
1357 	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1358 	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1359 	 * and call transport_generic_request_failure() if necessary..
1360 	 */
1361 	ret = transport_generic_new_cmd(cmd);
1362 	if (ret)
1363 		transport_generic_request_failure(cmd, ret);
1364 	return 0;
1365 }
1366 EXPORT_SYMBOL(transport_handle_cdb_direct);
1367 
1368 sense_reason_t
1369 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1370 		u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1371 {
1372 	if (!sgl || !sgl_count)
1373 		return 0;
1374 
1375 	/*
1376 	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1377 	 * scatterlists already have been set to follow what the fabric
1378 	 * passes for the original expected data transfer length.
1379 	 */
1380 	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1381 		pr_warn("Rejecting SCSI DATA overflow for fabric using"
1382 			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1383 		return TCM_INVALID_CDB_FIELD;
1384 	}
1385 
1386 	cmd->t_data_sg = sgl;
1387 	cmd->t_data_nents = sgl_count;
1388 	cmd->t_bidi_data_sg = sgl_bidi;
1389 	cmd->t_bidi_data_nents = sgl_bidi_count;
1390 
1391 	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1392 	return 0;
1393 }
1394 
1395 /*
1396  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1397  * 			 se_cmd + use pre-allocated SGL memory.
1398  *
1399  * @se_cmd: command descriptor to submit
1400  * @se_sess: associated se_sess for endpoint
1401  * @cdb: pointer to SCSI CDB
1402  * @sense: pointer to SCSI sense buffer
1403  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1404  * @data_length: fabric expected data transfer length
1405  * @task_addr: SAM task attribute
1406  * @data_dir: DMA data direction
1407  * @flags: flags for command submission from target_sc_flags_tables
1408  * @sgl: struct scatterlist memory for unidirectional mapping
1409  * @sgl_count: scatterlist count for unidirectional mapping
1410  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1411  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1412  * @sgl_prot: struct scatterlist memory protection information
1413  * @sgl_prot_count: scatterlist count for protection information
1414  *
1415  * Task tags are supported if the caller has set @se_cmd->tag.
1416  *
1417  * Returns non zero to signal active I/O shutdown failure.  All other
1418  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1419  * but still return zero here.
1420  *
1421  * This may only be called from process context, and also currently
1422  * assumes internal allocation of fabric payload buffer by target-core.
1423  */
1424 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1425 		unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1426 		u32 data_length, int task_attr, int data_dir, int flags,
1427 		struct scatterlist *sgl, u32 sgl_count,
1428 		struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1429 		struct scatterlist *sgl_prot, u32 sgl_prot_count)
1430 {
1431 	struct se_portal_group *se_tpg;
1432 	sense_reason_t rc;
1433 	int ret;
1434 
1435 	se_tpg = se_sess->se_tpg;
1436 	BUG_ON(!se_tpg);
1437 	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1438 	BUG_ON(in_interrupt());
1439 	/*
1440 	 * Initialize se_cmd for target operation.  From this point
1441 	 * exceptions are handled by sending exception status via
1442 	 * target_core_fabric_ops->queue_status() callback
1443 	 */
1444 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1445 				data_length, data_dir, task_attr, sense);
1446 
1447 	if (flags & TARGET_SCF_USE_CPUID)
1448 		se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1449 	else
1450 		se_cmd->cpuid = WORK_CPU_UNBOUND;
1451 
1452 	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1453 		se_cmd->unknown_data_length = 1;
1454 	/*
1455 	 * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1456 	 * se_sess->sess_cmd_list.  A second kref_get here is necessary
1457 	 * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1458 	 * kref_put() to happen during fabric packet acknowledgement.
1459 	 */
1460 	ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1461 	if (ret)
1462 		return ret;
1463 	/*
1464 	 * Signal bidirectional data payloads to target-core
1465 	 */
1466 	if (flags & TARGET_SCF_BIDI_OP)
1467 		se_cmd->se_cmd_flags |= SCF_BIDI;
1468 	/*
1469 	 * Locate se_lun pointer and attach it to struct se_cmd
1470 	 */
1471 	rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1472 	if (rc) {
1473 		transport_send_check_condition_and_sense(se_cmd, rc, 0);
1474 		target_put_sess_cmd(se_cmd);
1475 		return 0;
1476 	}
1477 
1478 	rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1479 	if (rc != 0) {
1480 		transport_generic_request_failure(se_cmd, rc);
1481 		return 0;
1482 	}
1483 
1484 	/*
1485 	 * Save pointers for SGLs containing protection information,
1486 	 * if present.
1487 	 */
1488 	if (sgl_prot_count) {
1489 		se_cmd->t_prot_sg = sgl_prot;
1490 		se_cmd->t_prot_nents = sgl_prot_count;
1491 		se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1492 	}
1493 
1494 	/*
1495 	 * When a non zero sgl_count has been passed perform SGL passthrough
1496 	 * mapping for pre-allocated fabric memory instead of having target
1497 	 * core perform an internal SGL allocation..
1498 	 */
1499 	if (sgl_count != 0) {
1500 		BUG_ON(!sgl);
1501 
1502 		/*
1503 		 * A work-around for tcm_loop as some userspace code via
1504 		 * scsi-generic do not memset their associated read buffers,
1505 		 * so go ahead and do that here for type non-data CDBs.  Also
1506 		 * note that this is currently guaranteed to be a single SGL
1507 		 * for this case by target core in target_setup_cmd_from_cdb()
1508 		 * -> transport_generic_cmd_sequencer().
1509 		 */
1510 		if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1511 		     se_cmd->data_direction == DMA_FROM_DEVICE) {
1512 			unsigned char *buf = NULL;
1513 
1514 			if (sgl)
1515 				buf = kmap(sg_page(sgl)) + sgl->offset;
1516 
1517 			if (buf) {
1518 				memset(buf, 0, sgl->length);
1519 				kunmap(sg_page(sgl));
1520 			}
1521 		}
1522 
1523 		rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1524 				sgl_bidi, sgl_bidi_count);
1525 		if (rc != 0) {
1526 			transport_generic_request_failure(se_cmd, rc);
1527 			return 0;
1528 		}
1529 	}
1530 
1531 	/*
1532 	 * Check if we need to delay processing because of ALUA
1533 	 * Active/NonOptimized primary access state..
1534 	 */
1535 	core_alua_check_nonop_delay(se_cmd);
1536 
1537 	transport_handle_cdb_direct(se_cmd);
1538 	return 0;
1539 }
1540 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1541 
1542 /*
1543  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1544  *
1545  * @se_cmd: command descriptor to submit
1546  * @se_sess: associated se_sess for endpoint
1547  * @cdb: pointer to SCSI CDB
1548  * @sense: pointer to SCSI sense buffer
1549  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1550  * @data_length: fabric expected data transfer length
1551  * @task_addr: SAM task attribute
1552  * @data_dir: DMA data direction
1553  * @flags: flags for command submission from target_sc_flags_tables
1554  *
1555  * Task tags are supported if the caller has set @se_cmd->tag.
1556  *
1557  * Returns non zero to signal active I/O shutdown failure.  All other
1558  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1559  * but still return zero here.
1560  *
1561  * This may only be called from process context, and also currently
1562  * assumes internal allocation of fabric payload buffer by target-core.
1563  *
1564  * It also assumes interal target core SGL memory allocation.
1565  */
1566 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1567 		unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1568 		u32 data_length, int task_attr, int data_dir, int flags)
1569 {
1570 	return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1571 			unpacked_lun, data_length, task_attr, data_dir,
1572 			flags, NULL, 0, NULL, 0, NULL, 0);
1573 }
1574 EXPORT_SYMBOL(target_submit_cmd);
1575 
1576 static void target_complete_tmr_failure(struct work_struct *work)
1577 {
1578 	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1579 
1580 	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1581 	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1582 
1583 	transport_cmd_check_stop_to_fabric(se_cmd);
1584 }
1585 
1586 /**
1587  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1588  *                     for TMR CDBs
1589  *
1590  * @se_cmd: command descriptor to submit
1591  * @se_sess: associated se_sess for endpoint
1592  * @sense: pointer to SCSI sense buffer
1593  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1594  * @fabric_context: fabric context for TMR req
1595  * @tm_type: Type of TM request
1596  * @gfp: gfp type for caller
1597  * @tag: referenced task tag for TMR_ABORT_TASK
1598  * @flags: submit cmd flags
1599  *
1600  * Callable from all contexts.
1601  **/
1602 
1603 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1604 		unsigned char *sense, u64 unpacked_lun,
1605 		void *fabric_tmr_ptr, unsigned char tm_type,
1606 		gfp_t gfp, u64 tag, int flags)
1607 {
1608 	struct se_portal_group *se_tpg;
1609 	int ret;
1610 
1611 	se_tpg = se_sess->se_tpg;
1612 	BUG_ON(!se_tpg);
1613 
1614 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1615 			      0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1616 	/*
1617 	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1618 	 * allocation failure.
1619 	 */
1620 	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1621 	if (ret < 0)
1622 		return -ENOMEM;
1623 
1624 	if (tm_type == TMR_ABORT_TASK)
1625 		se_cmd->se_tmr_req->ref_task_tag = tag;
1626 
1627 	/* See target_submit_cmd for commentary */
1628 	ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1629 	if (ret) {
1630 		core_tmr_release_req(se_cmd->se_tmr_req);
1631 		return ret;
1632 	}
1633 
1634 	ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1635 	if (ret) {
1636 		/*
1637 		 * For callback during failure handling, push this work off
1638 		 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1639 		 */
1640 		INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1641 		schedule_work(&se_cmd->work);
1642 		return 0;
1643 	}
1644 	transport_generic_handle_tmr(se_cmd);
1645 	return 0;
1646 }
1647 EXPORT_SYMBOL(target_submit_tmr);
1648 
1649 /*
1650  * Handle SAM-esque emulation for generic transport request failures.
1651  */
1652 void transport_generic_request_failure(struct se_cmd *cmd,
1653 		sense_reason_t sense_reason)
1654 {
1655 	int ret = 0, post_ret = 0;
1656 
1657 	pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08llx"
1658 		" CDB: 0x%02x\n", cmd, cmd->tag, cmd->t_task_cdb[0]);
1659 	pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1660 		cmd->se_tfo->get_cmd_state(cmd),
1661 		cmd->t_state, sense_reason);
1662 	pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1663 		(cmd->transport_state & CMD_T_ACTIVE) != 0,
1664 		(cmd->transport_state & CMD_T_STOP) != 0,
1665 		(cmd->transport_state & CMD_T_SENT) != 0);
1666 
1667 	/*
1668 	 * For SAM Task Attribute emulation for failed struct se_cmd
1669 	 */
1670 	transport_complete_task_attr(cmd);
1671 	/*
1672 	 * Handle special case for COMPARE_AND_WRITE failure, where the
1673 	 * callback is expected to drop the per device ->caw_sem.
1674 	 */
1675 	if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1676 	     cmd->transport_complete_callback)
1677 		cmd->transport_complete_callback(cmd, false, &post_ret);
1678 
1679 	switch (sense_reason) {
1680 	case TCM_NON_EXISTENT_LUN:
1681 	case TCM_UNSUPPORTED_SCSI_OPCODE:
1682 	case TCM_INVALID_CDB_FIELD:
1683 	case TCM_INVALID_PARAMETER_LIST:
1684 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
1685 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1686 	case TCM_UNKNOWN_MODE_PAGE:
1687 	case TCM_WRITE_PROTECTED:
1688 	case TCM_ADDRESS_OUT_OF_RANGE:
1689 	case TCM_CHECK_CONDITION_ABORT_CMD:
1690 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1691 	case TCM_CHECK_CONDITION_NOT_READY:
1692 	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1693 	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1694 	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1695 	case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
1696 	case TCM_TOO_MANY_TARGET_DESCS:
1697 	case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
1698 	case TCM_TOO_MANY_SEGMENT_DESCS:
1699 	case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
1700 		break;
1701 	case TCM_OUT_OF_RESOURCES:
1702 		sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1703 		break;
1704 	case TCM_RESERVATION_CONFLICT:
1705 		/*
1706 		 * No SENSE Data payload for this case, set SCSI Status
1707 		 * and queue the response to $FABRIC_MOD.
1708 		 *
1709 		 * Uses linux/include/scsi/scsi.h SAM status codes defs
1710 		 */
1711 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1712 		/*
1713 		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1714 		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1715 		 * CONFLICT STATUS.
1716 		 *
1717 		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1718 		 */
1719 		if (cmd->se_sess &&
1720 		    cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1721 			target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1722 					       cmd->orig_fe_lun, 0x2C,
1723 					ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1724 		}
1725 		trace_target_cmd_complete(cmd);
1726 		ret = cmd->se_tfo->queue_status(cmd);
1727 		if (ret == -EAGAIN || ret == -ENOMEM)
1728 			goto queue_full;
1729 		goto check_stop;
1730 	default:
1731 		pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1732 			cmd->t_task_cdb[0], sense_reason);
1733 		sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1734 		break;
1735 	}
1736 
1737 	ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1738 	if (ret == -EAGAIN || ret == -ENOMEM)
1739 		goto queue_full;
1740 
1741 check_stop:
1742 	transport_lun_remove_cmd(cmd);
1743 	transport_cmd_check_stop_to_fabric(cmd);
1744 	return;
1745 
1746 queue_full:
1747 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1748 	transport_handle_queue_full(cmd, cmd->se_dev);
1749 }
1750 EXPORT_SYMBOL(transport_generic_request_failure);
1751 
1752 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
1753 {
1754 	sense_reason_t ret;
1755 
1756 	if (!cmd->execute_cmd) {
1757 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1758 		goto err;
1759 	}
1760 	if (do_checks) {
1761 		/*
1762 		 * Check for an existing UNIT ATTENTION condition after
1763 		 * target_handle_task_attr() has done SAM task attr
1764 		 * checking, and possibly have already defered execution
1765 		 * out to target_restart_delayed_cmds() context.
1766 		 */
1767 		ret = target_scsi3_ua_check(cmd);
1768 		if (ret)
1769 			goto err;
1770 
1771 		ret = target_alua_state_check(cmd);
1772 		if (ret)
1773 			goto err;
1774 
1775 		ret = target_check_reservation(cmd);
1776 		if (ret) {
1777 			cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1778 			goto err;
1779 		}
1780 	}
1781 
1782 	ret = cmd->execute_cmd(cmd);
1783 	if (!ret)
1784 		return;
1785 err:
1786 	spin_lock_irq(&cmd->t_state_lock);
1787 	cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1788 	spin_unlock_irq(&cmd->t_state_lock);
1789 
1790 	transport_generic_request_failure(cmd, ret);
1791 }
1792 
1793 static int target_write_prot_action(struct se_cmd *cmd)
1794 {
1795 	u32 sectors;
1796 	/*
1797 	 * Perform WRITE_INSERT of PI using software emulation when backend
1798 	 * device has PI enabled, if the transport has not already generated
1799 	 * PI using hardware WRITE_INSERT offload.
1800 	 */
1801 	switch (cmd->prot_op) {
1802 	case TARGET_PROT_DOUT_INSERT:
1803 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1804 			sbc_dif_generate(cmd);
1805 		break;
1806 	case TARGET_PROT_DOUT_STRIP:
1807 		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1808 			break;
1809 
1810 		sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1811 		cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1812 					     sectors, 0, cmd->t_prot_sg, 0);
1813 		if (unlikely(cmd->pi_err)) {
1814 			spin_lock_irq(&cmd->t_state_lock);
1815 			cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1816 			spin_unlock_irq(&cmd->t_state_lock);
1817 			transport_generic_request_failure(cmd, cmd->pi_err);
1818 			return -1;
1819 		}
1820 		break;
1821 	default:
1822 		break;
1823 	}
1824 
1825 	return 0;
1826 }
1827 
1828 static bool target_handle_task_attr(struct se_cmd *cmd)
1829 {
1830 	struct se_device *dev = cmd->se_dev;
1831 
1832 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1833 		return false;
1834 
1835 	cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
1836 
1837 	/*
1838 	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1839 	 * to allow the passed struct se_cmd list of tasks to the front of the list.
1840 	 */
1841 	switch (cmd->sam_task_attr) {
1842 	case TCM_HEAD_TAG:
1843 		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
1844 			 cmd->t_task_cdb[0]);
1845 		return false;
1846 	case TCM_ORDERED_TAG:
1847 		atomic_inc_mb(&dev->dev_ordered_sync);
1848 
1849 		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
1850 			 cmd->t_task_cdb[0]);
1851 
1852 		/*
1853 		 * Execute an ORDERED command if no other older commands
1854 		 * exist that need to be completed first.
1855 		 */
1856 		if (!atomic_read(&dev->simple_cmds))
1857 			return false;
1858 		break;
1859 	default:
1860 		/*
1861 		 * For SIMPLE and UNTAGGED Task Attribute commands
1862 		 */
1863 		atomic_inc_mb(&dev->simple_cmds);
1864 		break;
1865 	}
1866 
1867 	if (atomic_read(&dev->dev_ordered_sync) == 0)
1868 		return false;
1869 
1870 	spin_lock(&dev->delayed_cmd_lock);
1871 	list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1872 	spin_unlock(&dev->delayed_cmd_lock);
1873 
1874 	pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
1875 		cmd->t_task_cdb[0], cmd->sam_task_attr);
1876 	return true;
1877 }
1878 
1879 static int __transport_check_aborted_status(struct se_cmd *, int);
1880 
1881 void target_execute_cmd(struct se_cmd *cmd)
1882 {
1883 	/*
1884 	 * Determine if frontend context caller is requesting the stopping of
1885 	 * this command for frontend exceptions.
1886 	 *
1887 	 * If the received CDB has aleady been aborted stop processing it here.
1888 	 */
1889 	spin_lock_irq(&cmd->t_state_lock);
1890 	if (__transport_check_aborted_status(cmd, 1)) {
1891 		spin_unlock_irq(&cmd->t_state_lock);
1892 		return;
1893 	}
1894 	if (cmd->transport_state & CMD_T_STOP) {
1895 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
1896 			__func__, __LINE__, cmd->tag);
1897 
1898 		spin_unlock_irq(&cmd->t_state_lock);
1899 		complete_all(&cmd->t_transport_stop_comp);
1900 		return;
1901 	}
1902 
1903 	cmd->t_state = TRANSPORT_PROCESSING;
1904 	cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1905 	spin_unlock_irq(&cmd->t_state_lock);
1906 
1907 	if (target_write_prot_action(cmd))
1908 		return;
1909 
1910 	if (target_handle_task_attr(cmd)) {
1911 		spin_lock_irq(&cmd->t_state_lock);
1912 		cmd->transport_state &= ~(CMD_T_BUSY | CMD_T_SENT);
1913 		spin_unlock_irq(&cmd->t_state_lock);
1914 		return;
1915 	}
1916 
1917 	__target_execute_cmd(cmd, true);
1918 }
1919 EXPORT_SYMBOL(target_execute_cmd);
1920 
1921 /*
1922  * Process all commands up to the last received ORDERED task attribute which
1923  * requires another blocking boundary
1924  */
1925 static void target_restart_delayed_cmds(struct se_device *dev)
1926 {
1927 	for (;;) {
1928 		struct se_cmd *cmd;
1929 
1930 		spin_lock(&dev->delayed_cmd_lock);
1931 		if (list_empty(&dev->delayed_cmd_list)) {
1932 			spin_unlock(&dev->delayed_cmd_lock);
1933 			break;
1934 		}
1935 
1936 		cmd = list_entry(dev->delayed_cmd_list.next,
1937 				 struct se_cmd, se_delayed_node);
1938 		list_del(&cmd->se_delayed_node);
1939 		spin_unlock(&dev->delayed_cmd_lock);
1940 
1941 		__target_execute_cmd(cmd, true);
1942 
1943 		if (cmd->sam_task_attr == TCM_ORDERED_TAG)
1944 			break;
1945 	}
1946 }
1947 
1948 /*
1949  * Called from I/O completion to determine which dormant/delayed
1950  * and ordered cmds need to have their tasks added to the execution queue.
1951  */
1952 static void transport_complete_task_attr(struct se_cmd *cmd)
1953 {
1954 	struct se_device *dev = cmd->se_dev;
1955 
1956 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1957 		return;
1958 
1959 	if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
1960 		goto restart;
1961 
1962 	if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
1963 		atomic_dec_mb(&dev->simple_cmds);
1964 		dev->dev_cur_ordered_id++;
1965 		pr_debug("Incremented dev->dev_cur_ordered_id: %u for SIMPLE\n",
1966 			 dev->dev_cur_ordered_id);
1967 	} else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
1968 		dev->dev_cur_ordered_id++;
1969 		pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
1970 			 dev->dev_cur_ordered_id);
1971 	} else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
1972 		atomic_dec_mb(&dev->dev_ordered_sync);
1973 
1974 		dev->dev_cur_ordered_id++;
1975 		pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
1976 			 dev->dev_cur_ordered_id);
1977 	}
1978 restart:
1979 	target_restart_delayed_cmds(dev);
1980 }
1981 
1982 static void transport_complete_qf(struct se_cmd *cmd)
1983 {
1984 	int ret = 0;
1985 
1986 	transport_complete_task_attr(cmd);
1987 
1988 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1989 		trace_target_cmd_complete(cmd);
1990 		ret = cmd->se_tfo->queue_status(cmd);
1991 		goto out;
1992 	}
1993 
1994 	switch (cmd->data_direction) {
1995 	case DMA_FROM_DEVICE:
1996 		if (cmd->scsi_status)
1997 			goto queue_status;
1998 
1999 		trace_target_cmd_complete(cmd);
2000 		ret = cmd->se_tfo->queue_data_in(cmd);
2001 		break;
2002 	case DMA_TO_DEVICE:
2003 		if (cmd->se_cmd_flags & SCF_BIDI) {
2004 			ret = cmd->se_tfo->queue_data_in(cmd);
2005 			break;
2006 		}
2007 		/* Fall through for DMA_TO_DEVICE */
2008 	case DMA_NONE:
2009 queue_status:
2010 		trace_target_cmd_complete(cmd);
2011 		ret = cmd->se_tfo->queue_status(cmd);
2012 		break;
2013 	default:
2014 		break;
2015 	}
2016 
2017 out:
2018 	if (ret < 0) {
2019 		transport_handle_queue_full(cmd, cmd->se_dev);
2020 		return;
2021 	}
2022 	transport_lun_remove_cmd(cmd);
2023 	transport_cmd_check_stop_to_fabric(cmd);
2024 }
2025 
2026 static void transport_handle_queue_full(
2027 	struct se_cmd *cmd,
2028 	struct se_device *dev)
2029 {
2030 	spin_lock_irq(&dev->qf_cmd_lock);
2031 	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2032 	atomic_inc_mb(&dev->dev_qf_count);
2033 	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2034 
2035 	schedule_work(&cmd->se_dev->qf_work_queue);
2036 }
2037 
2038 static bool target_read_prot_action(struct se_cmd *cmd)
2039 {
2040 	switch (cmd->prot_op) {
2041 	case TARGET_PROT_DIN_STRIP:
2042 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2043 			u32 sectors = cmd->data_length >>
2044 				  ilog2(cmd->se_dev->dev_attrib.block_size);
2045 
2046 			cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2047 						     sectors, 0, cmd->t_prot_sg,
2048 						     0);
2049 			if (cmd->pi_err)
2050 				return true;
2051 		}
2052 		break;
2053 	case TARGET_PROT_DIN_INSERT:
2054 		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2055 			break;
2056 
2057 		sbc_dif_generate(cmd);
2058 		break;
2059 	default:
2060 		break;
2061 	}
2062 
2063 	return false;
2064 }
2065 
2066 static void target_complete_ok_work(struct work_struct *work)
2067 {
2068 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2069 	int ret;
2070 
2071 	/*
2072 	 * Check if we need to move delayed/dormant tasks from cmds on the
2073 	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2074 	 * Attribute.
2075 	 */
2076 	transport_complete_task_attr(cmd);
2077 
2078 	/*
2079 	 * Check to schedule QUEUE_FULL work, or execute an existing
2080 	 * cmd->transport_qf_callback()
2081 	 */
2082 	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2083 		schedule_work(&cmd->se_dev->qf_work_queue);
2084 
2085 	/*
2086 	 * Check if we need to send a sense buffer from
2087 	 * the struct se_cmd in question.
2088 	 */
2089 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2090 		WARN_ON(!cmd->scsi_status);
2091 		ret = transport_send_check_condition_and_sense(
2092 					cmd, 0, 1);
2093 		if (ret == -EAGAIN || ret == -ENOMEM)
2094 			goto queue_full;
2095 
2096 		transport_lun_remove_cmd(cmd);
2097 		transport_cmd_check_stop_to_fabric(cmd);
2098 		return;
2099 	}
2100 	/*
2101 	 * Check for a callback, used by amongst other things
2102 	 * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2103 	 */
2104 	if (cmd->transport_complete_callback) {
2105 		sense_reason_t rc;
2106 		bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2107 		bool zero_dl = !(cmd->data_length);
2108 		int post_ret = 0;
2109 
2110 		rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2111 		if (!rc && !post_ret) {
2112 			if (caw && zero_dl)
2113 				goto queue_rsp;
2114 
2115 			return;
2116 		} else if (rc) {
2117 			ret = transport_send_check_condition_and_sense(cmd,
2118 						rc, 0);
2119 			if (ret == -EAGAIN || ret == -ENOMEM)
2120 				goto queue_full;
2121 
2122 			transport_lun_remove_cmd(cmd);
2123 			transport_cmd_check_stop_to_fabric(cmd);
2124 			return;
2125 		}
2126 	}
2127 
2128 queue_rsp:
2129 	switch (cmd->data_direction) {
2130 	case DMA_FROM_DEVICE:
2131 		if (cmd->scsi_status)
2132 			goto queue_status;
2133 
2134 		atomic_long_add(cmd->data_length,
2135 				&cmd->se_lun->lun_stats.tx_data_octets);
2136 		/*
2137 		 * Perform READ_STRIP of PI using software emulation when
2138 		 * backend had PI enabled, if the transport will not be
2139 		 * performing hardware READ_STRIP offload.
2140 		 */
2141 		if (target_read_prot_action(cmd)) {
2142 			ret = transport_send_check_condition_and_sense(cmd,
2143 						cmd->pi_err, 0);
2144 			if (ret == -EAGAIN || ret == -ENOMEM)
2145 				goto queue_full;
2146 
2147 			transport_lun_remove_cmd(cmd);
2148 			transport_cmd_check_stop_to_fabric(cmd);
2149 			return;
2150 		}
2151 
2152 		trace_target_cmd_complete(cmd);
2153 		ret = cmd->se_tfo->queue_data_in(cmd);
2154 		if (ret == -EAGAIN || ret == -ENOMEM)
2155 			goto queue_full;
2156 		break;
2157 	case DMA_TO_DEVICE:
2158 		atomic_long_add(cmd->data_length,
2159 				&cmd->se_lun->lun_stats.rx_data_octets);
2160 		/*
2161 		 * Check if we need to send READ payload for BIDI-COMMAND
2162 		 */
2163 		if (cmd->se_cmd_flags & SCF_BIDI) {
2164 			atomic_long_add(cmd->data_length,
2165 					&cmd->se_lun->lun_stats.tx_data_octets);
2166 			ret = cmd->se_tfo->queue_data_in(cmd);
2167 			if (ret == -EAGAIN || ret == -ENOMEM)
2168 				goto queue_full;
2169 			break;
2170 		}
2171 		/* Fall through for DMA_TO_DEVICE */
2172 	case DMA_NONE:
2173 queue_status:
2174 		trace_target_cmd_complete(cmd);
2175 		ret = cmd->se_tfo->queue_status(cmd);
2176 		if (ret == -EAGAIN || ret == -ENOMEM)
2177 			goto queue_full;
2178 		break;
2179 	default:
2180 		break;
2181 	}
2182 
2183 	transport_lun_remove_cmd(cmd);
2184 	transport_cmd_check_stop_to_fabric(cmd);
2185 	return;
2186 
2187 queue_full:
2188 	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2189 		" data_direction: %d\n", cmd, cmd->data_direction);
2190 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2191 	transport_handle_queue_full(cmd, cmd->se_dev);
2192 }
2193 
2194 void target_free_sgl(struct scatterlist *sgl, int nents)
2195 {
2196 	struct scatterlist *sg;
2197 	int count;
2198 
2199 	for_each_sg(sgl, sg, nents, count)
2200 		__free_page(sg_page(sg));
2201 
2202 	kfree(sgl);
2203 }
2204 EXPORT_SYMBOL(target_free_sgl);
2205 
2206 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2207 {
2208 	/*
2209 	 * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2210 	 * emulation, and free + reset pointers if necessary..
2211 	 */
2212 	if (!cmd->t_data_sg_orig)
2213 		return;
2214 
2215 	kfree(cmd->t_data_sg);
2216 	cmd->t_data_sg = cmd->t_data_sg_orig;
2217 	cmd->t_data_sg_orig = NULL;
2218 	cmd->t_data_nents = cmd->t_data_nents_orig;
2219 	cmd->t_data_nents_orig = 0;
2220 }
2221 
2222 static inline void transport_free_pages(struct se_cmd *cmd)
2223 {
2224 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2225 		target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2226 		cmd->t_prot_sg = NULL;
2227 		cmd->t_prot_nents = 0;
2228 	}
2229 
2230 	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2231 		/*
2232 		 * Release special case READ buffer payload required for
2233 		 * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2234 		 */
2235 		if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2236 			target_free_sgl(cmd->t_bidi_data_sg,
2237 					   cmd->t_bidi_data_nents);
2238 			cmd->t_bidi_data_sg = NULL;
2239 			cmd->t_bidi_data_nents = 0;
2240 		}
2241 		transport_reset_sgl_orig(cmd);
2242 		return;
2243 	}
2244 	transport_reset_sgl_orig(cmd);
2245 
2246 	target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2247 	cmd->t_data_sg = NULL;
2248 	cmd->t_data_nents = 0;
2249 
2250 	target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2251 	cmd->t_bidi_data_sg = NULL;
2252 	cmd->t_bidi_data_nents = 0;
2253 }
2254 
2255 /**
2256  * transport_put_cmd - release a reference to a command
2257  * @cmd:       command to release
2258  *
2259  * This routine releases our reference to the command and frees it if possible.
2260  */
2261 static int transport_put_cmd(struct se_cmd *cmd)
2262 {
2263 	BUG_ON(!cmd->se_tfo);
2264 	/*
2265 	 * If this cmd has been setup with target_get_sess_cmd(), drop
2266 	 * the kref and call ->release_cmd() in kref callback.
2267 	 */
2268 	return target_put_sess_cmd(cmd);
2269 }
2270 
2271 void *transport_kmap_data_sg(struct se_cmd *cmd)
2272 {
2273 	struct scatterlist *sg = cmd->t_data_sg;
2274 	struct page **pages;
2275 	int i;
2276 
2277 	/*
2278 	 * We need to take into account a possible offset here for fabrics like
2279 	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2280 	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2281 	 */
2282 	if (!cmd->t_data_nents)
2283 		return NULL;
2284 
2285 	BUG_ON(!sg);
2286 	if (cmd->t_data_nents == 1)
2287 		return kmap(sg_page(sg)) + sg->offset;
2288 
2289 	/* >1 page. use vmap */
2290 	pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2291 	if (!pages)
2292 		return NULL;
2293 
2294 	/* convert sg[] to pages[] */
2295 	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2296 		pages[i] = sg_page(sg);
2297 	}
2298 
2299 	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2300 	kfree(pages);
2301 	if (!cmd->t_data_vmap)
2302 		return NULL;
2303 
2304 	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2305 }
2306 EXPORT_SYMBOL(transport_kmap_data_sg);
2307 
2308 void transport_kunmap_data_sg(struct se_cmd *cmd)
2309 {
2310 	if (!cmd->t_data_nents) {
2311 		return;
2312 	} else if (cmd->t_data_nents == 1) {
2313 		kunmap(sg_page(cmd->t_data_sg));
2314 		return;
2315 	}
2316 
2317 	vunmap(cmd->t_data_vmap);
2318 	cmd->t_data_vmap = NULL;
2319 }
2320 EXPORT_SYMBOL(transport_kunmap_data_sg);
2321 
2322 int
2323 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2324 		 bool zero_page, bool chainable)
2325 {
2326 	struct scatterlist *sg;
2327 	struct page *page;
2328 	gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2329 	unsigned int nalloc, nent;
2330 	int i = 0;
2331 
2332 	nalloc = nent = DIV_ROUND_UP(length, PAGE_SIZE);
2333 	if (chainable)
2334 		nalloc++;
2335 	sg = kmalloc_array(nalloc, sizeof(struct scatterlist), GFP_KERNEL);
2336 	if (!sg)
2337 		return -ENOMEM;
2338 
2339 	sg_init_table(sg, nalloc);
2340 
2341 	while (length) {
2342 		u32 page_len = min_t(u32, length, PAGE_SIZE);
2343 		page = alloc_page(GFP_KERNEL | zero_flag);
2344 		if (!page)
2345 			goto out;
2346 
2347 		sg_set_page(&sg[i], page, page_len, 0);
2348 		length -= page_len;
2349 		i++;
2350 	}
2351 	*sgl = sg;
2352 	*nents = nent;
2353 	return 0;
2354 
2355 out:
2356 	while (i > 0) {
2357 		i--;
2358 		__free_page(sg_page(&sg[i]));
2359 	}
2360 	kfree(sg);
2361 	return -ENOMEM;
2362 }
2363 EXPORT_SYMBOL(target_alloc_sgl);
2364 
2365 /*
2366  * Allocate any required resources to execute the command.  For writes we
2367  * might not have the payload yet, so notify the fabric via a call to
2368  * ->write_pending instead. Otherwise place it on the execution queue.
2369  */
2370 sense_reason_t
2371 transport_generic_new_cmd(struct se_cmd *cmd)
2372 {
2373 	int ret = 0;
2374 	bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2375 
2376 	if (cmd->prot_op != TARGET_PROT_NORMAL &&
2377 	    !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2378 		ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2379 				       cmd->prot_length, true, false);
2380 		if (ret < 0)
2381 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2382 	}
2383 
2384 	/*
2385 	 * Determine is the TCM fabric module has already allocated physical
2386 	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2387 	 * beforehand.
2388 	 */
2389 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2390 	    cmd->data_length) {
2391 
2392 		if ((cmd->se_cmd_flags & SCF_BIDI) ||
2393 		    (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2394 			u32 bidi_length;
2395 
2396 			if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2397 				bidi_length = cmd->t_task_nolb *
2398 					      cmd->se_dev->dev_attrib.block_size;
2399 			else
2400 				bidi_length = cmd->data_length;
2401 
2402 			ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2403 					       &cmd->t_bidi_data_nents,
2404 					       bidi_length, zero_flag, false);
2405 			if (ret < 0)
2406 				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2407 		}
2408 
2409 		ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2410 				       cmd->data_length, zero_flag, false);
2411 		if (ret < 0)
2412 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2413 	} else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2414 		    cmd->data_length) {
2415 		/*
2416 		 * Special case for COMPARE_AND_WRITE with fabrics
2417 		 * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2418 		 */
2419 		u32 caw_length = cmd->t_task_nolb *
2420 				 cmd->se_dev->dev_attrib.block_size;
2421 
2422 		ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2423 				       &cmd->t_bidi_data_nents,
2424 				       caw_length, zero_flag, false);
2425 		if (ret < 0)
2426 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2427 	}
2428 	/*
2429 	 * If this command is not a write we can execute it right here,
2430 	 * for write buffers we need to notify the fabric driver first
2431 	 * and let it call back once the write buffers are ready.
2432 	 */
2433 	target_add_to_state_list(cmd);
2434 	if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2435 		target_execute_cmd(cmd);
2436 		return 0;
2437 	}
2438 	transport_cmd_check_stop(cmd, false, true);
2439 
2440 	ret = cmd->se_tfo->write_pending(cmd);
2441 	if (ret == -EAGAIN || ret == -ENOMEM)
2442 		goto queue_full;
2443 
2444 	/* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2445 	WARN_ON(ret);
2446 
2447 	return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2448 
2449 queue_full:
2450 	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2451 	cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2452 	transport_handle_queue_full(cmd, cmd->se_dev);
2453 	return 0;
2454 }
2455 EXPORT_SYMBOL(transport_generic_new_cmd);
2456 
2457 static void transport_write_pending_qf(struct se_cmd *cmd)
2458 {
2459 	int ret;
2460 
2461 	ret = cmd->se_tfo->write_pending(cmd);
2462 	if (ret == -EAGAIN || ret == -ENOMEM) {
2463 		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2464 			 cmd);
2465 		transport_handle_queue_full(cmd, cmd->se_dev);
2466 	}
2467 }
2468 
2469 static bool
2470 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2471 			   unsigned long *flags);
2472 
2473 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2474 {
2475 	unsigned long flags;
2476 
2477 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2478 	__transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2479 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2480 }
2481 
2482 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2483 {
2484 	int ret = 0;
2485 	bool aborted = false, tas = false;
2486 
2487 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2488 		if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2489 			target_wait_free_cmd(cmd, &aborted, &tas);
2490 
2491 		if (!aborted || tas)
2492 			ret = transport_put_cmd(cmd);
2493 	} else {
2494 		if (wait_for_tasks)
2495 			target_wait_free_cmd(cmd, &aborted, &tas);
2496 		/*
2497 		 * Handle WRITE failure case where transport_generic_new_cmd()
2498 		 * has already added se_cmd to state_list, but fabric has
2499 		 * failed command before I/O submission.
2500 		 */
2501 		if (cmd->state_active)
2502 			target_remove_from_state_list(cmd);
2503 
2504 		if (cmd->se_lun)
2505 			transport_lun_remove_cmd(cmd);
2506 
2507 		if (!aborted || tas)
2508 			ret = transport_put_cmd(cmd);
2509 	}
2510 	/*
2511 	 * If the task has been internally aborted due to TMR ABORT_TASK
2512 	 * or LUN_RESET, target_core_tmr.c is responsible for performing
2513 	 * the remaining calls to target_put_sess_cmd(), and not the
2514 	 * callers of this function.
2515 	 */
2516 	if (aborted) {
2517 		pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2518 		wait_for_completion(&cmd->cmd_wait_comp);
2519 		cmd->se_tfo->release_cmd(cmd);
2520 		ret = 1;
2521 	}
2522 	return ret;
2523 }
2524 EXPORT_SYMBOL(transport_generic_free_cmd);
2525 
2526 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2527  * @se_cmd:	command descriptor to add
2528  * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
2529  */
2530 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2531 {
2532 	struct se_session *se_sess = se_cmd->se_sess;
2533 	unsigned long flags;
2534 	int ret = 0;
2535 
2536 	/*
2537 	 * Add a second kref if the fabric caller is expecting to handle
2538 	 * fabric acknowledgement that requires two target_put_sess_cmd()
2539 	 * invocations before se_cmd descriptor release.
2540 	 */
2541 	if (ack_kref) {
2542 		if (!kref_get_unless_zero(&se_cmd->cmd_kref))
2543 			return -EINVAL;
2544 
2545 		se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2546 	}
2547 
2548 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2549 	if (se_sess->sess_tearing_down) {
2550 		ret = -ESHUTDOWN;
2551 		goto out;
2552 	}
2553 	list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2554 out:
2555 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2556 
2557 	if (ret && ack_kref)
2558 		target_put_sess_cmd(se_cmd);
2559 
2560 	return ret;
2561 }
2562 EXPORT_SYMBOL(target_get_sess_cmd);
2563 
2564 static void target_free_cmd_mem(struct se_cmd *cmd)
2565 {
2566 	transport_free_pages(cmd);
2567 
2568 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2569 		core_tmr_release_req(cmd->se_tmr_req);
2570 	if (cmd->t_task_cdb != cmd->__t_task_cdb)
2571 		kfree(cmd->t_task_cdb);
2572 }
2573 
2574 static void target_release_cmd_kref(struct kref *kref)
2575 {
2576 	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2577 	struct se_session *se_sess = se_cmd->se_sess;
2578 	unsigned long flags;
2579 	bool fabric_stop;
2580 
2581 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2582 
2583 	spin_lock(&se_cmd->t_state_lock);
2584 	fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP) &&
2585 		      (se_cmd->transport_state & CMD_T_ABORTED);
2586 	spin_unlock(&se_cmd->t_state_lock);
2587 
2588 	if (se_cmd->cmd_wait_set || fabric_stop) {
2589 		list_del_init(&se_cmd->se_cmd_list);
2590 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2591 		target_free_cmd_mem(se_cmd);
2592 		complete(&se_cmd->cmd_wait_comp);
2593 		return;
2594 	}
2595 	list_del_init(&se_cmd->se_cmd_list);
2596 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2597 
2598 	target_free_cmd_mem(se_cmd);
2599 	se_cmd->se_tfo->release_cmd(se_cmd);
2600 }
2601 
2602 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2603  * @se_cmd:	command descriptor to drop
2604  */
2605 int target_put_sess_cmd(struct se_cmd *se_cmd)
2606 {
2607 	struct se_session *se_sess = se_cmd->se_sess;
2608 
2609 	if (!se_sess) {
2610 		target_free_cmd_mem(se_cmd);
2611 		se_cmd->se_tfo->release_cmd(se_cmd);
2612 		return 1;
2613 	}
2614 	return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2615 }
2616 EXPORT_SYMBOL(target_put_sess_cmd);
2617 
2618 /* target_sess_cmd_list_set_waiting - Flag all commands in
2619  *         sess_cmd_list to complete cmd_wait_comp.  Set
2620  *         sess_tearing_down so no more commands are queued.
2621  * @se_sess:	session to flag
2622  */
2623 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2624 {
2625 	struct se_cmd *se_cmd, *tmp_cmd;
2626 	unsigned long flags;
2627 	int rc;
2628 
2629 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2630 	if (se_sess->sess_tearing_down) {
2631 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2632 		return;
2633 	}
2634 	se_sess->sess_tearing_down = 1;
2635 	list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2636 
2637 	list_for_each_entry_safe(se_cmd, tmp_cmd,
2638 				 &se_sess->sess_wait_list, se_cmd_list) {
2639 		rc = kref_get_unless_zero(&se_cmd->cmd_kref);
2640 		if (rc) {
2641 			se_cmd->cmd_wait_set = 1;
2642 			spin_lock(&se_cmd->t_state_lock);
2643 			se_cmd->transport_state |= CMD_T_FABRIC_STOP;
2644 			spin_unlock(&se_cmd->t_state_lock);
2645 		} else
2646 			list_del_init(&se_cmd->se_cmd_list);
2647 	}
2648 
2649 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2650 }
2651 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2652 
2653 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2654  * @se_sess:    session to wait for active I/O
2655  */
2656 void target_wait_for_sess_cmds(struct se_session *se_sess)
2657 {
2658 	struct se_cmd *se_cmd, *tmp_cmd;
2659 	unsigned long flags;
2660 	bool tas;
2661 
2662 	list_for_each_entry_safe(se_cmd, tmp_cmd,
2663 				&se_sess->sess_wait_list, se_cmd_list) {
2664 		pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2665 			" %d\n", se_cmd, se_cmd->t_state,
2666 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2667 
2668 		spin_lock_irqsave(&se_cmd->t_state_lock, flags);
2669 		tas = (se_cmd->transport_state & CMD_T_TAS);
2670 		spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
2671 
2672 		if (!target_put_sess_cmd(se_cmd)) {
2673 			if (tas)
2674 				target_put_sess_cmd(se_cmd);
2675 		}
2676 
2677 		wait_for_completion(&se_cmd->cmd_wait_comp);
2678 		pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2679 			" fabric state: %d\n", se_cmd, se_cmd->t_state,
2680 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2681 
2682 		se_cmd->se_tfo->release_cmd(se_cmd);
2683 	}
2684 
2685 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2686 	WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2687 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2688 
2689 }
2690 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2691 
2692 void transport_clear_lun_ref(struct se_lun *lun)
2693 {
2694 	percpu_ref_kill(&lun->lun_ref);
2695 	wait_for_completion(&lun->lun_ref_comp);
2696 }
2697 
2698 static bool
2699 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2700 			   bool *aborted, bool *tas, unsigned long *flags)
2701 	__releases(&cmd->t_state_lock)
2702 	__acquires(&cmd->t_state_lock)
2703 {
2704 
2705 	assert_spin_locked(&cmd->t_state_lock);
2706 	WARN_ON_ONCE(!irqs_disabled());
2707 
2708 	if (fabric_stop)
2709 		cmd->transport_state |= CMD_T_FABRIC_STOP;
2710 
2711 	if (cmd->transport_state & CMD_T_ABORTED)
2712 		*aborted = true;
2713 
2714 	if (cmd->transport_state & CMD_T_TAS)
2715 		*tas = true;
2716 
2717 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2718 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2719 		return false;
2720 
2721 	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2722 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2723 		return false;
2724 
2725 	if (!(cmd->transport_state & CMD_T_ACTIVE))
2726 		return false;
2727 
2728 	if (fabric_stop && *aborted)
2729 		return false;
2730 
2731 	cmd->transport_state |= CMD_T_STOP;
2732 
2733 	pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08llx i_state: %d,"
2734 		 " t_state: %d, CMD_T_STOP\n", cmd, cmd->tag,
2735 		 cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2736 
2737 	spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
2738 
2739 	wait_for_completion(&cmd->t_transport_stop_comp);
2740 
2741 	spin_lock_irqsave(&cmd->t_state_lock, *flags);
2742 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2743 
2744 	pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
2745 		 "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
2746 
2747 	return true;
2748 }
2749 
2750 /**
2751  * transport_wait_for_tasks - wait for completion to occur
2752  * @cmd:	command to wait
2753  *
2754  * Called from frontend fabric context to wait for storage engine
2755  * to pause and/or release frontend generated struct se_cmd.
2756  */
2757 bool transport_wait_for_tasks(struct se_cmd *cmd)
2758 {
2759 	unsigned long flags;
2760 	bool ret, aborted = false, tas = false;
2761 
2762 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2763 	ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
2764 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2765 
2766 	return ret;
2767 }
2768 EXPORT_SYMBOL(transport_wait_for_tasks);
2769 
2770 struct sense_info {
2771 	u8 key;
2772 	u8 asc;
2773 	u8 ascq;
2774 	bool add_sector_info;
2775 };
2776 
2777 static const struct sense_info sense_info_table[] = {
2778 	[TCM_NO_SENSE] = {
2779 		.key = NOT_READY
2780 	},
2781 	[TCM_NON_EXISTENT_LUN] = {
2782 		.key = ILLEGAL_REQUEST,
2783 		.asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
2784 	},
2785 	[TCM_UNSUPPORTED_SCSI_OPCODE] = {
2786 		.key = ILLEGAL_REQUEST,
2787 		.asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2788 	},
2789 	[TCM_SECTOR_COUNT_TOO_MANY] = {
2790 		.key = ILLEGAL_REQUEST,
2791 		.asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2792 	},
2793 	[TCM_UNKNOWN_MODE_PAGE] = {
2794 		.key = ILLEGAL_REQUEST,
2795 		.asc = 0x24, /* INVALID FIELD IN CDB */
2796 	},
2797 	[TCM_CHECK_CONDITION_ABORT_CMD] = {
2798 		.key = ABORTED_COMMAND,
2799 		.asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
2800 		.ascq = 0x03,
2801 	},
2802 	[TCM_INCORRECT_AMOUNT_OF_DATA] = {
2803 		.key = ABORTED_COMMAND,
2804 		.asc = 0x0c, /* WRITE ERROR */
2805 		.ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
2806 	},
2807 	[TCM_INVALID_CDB_FIELD] = {
2808 		.key = ILLEGAL_REQUEST,
2809 		.asc = 0x24, /* INVALID FIELD IN CDB */
2810 	},
2811 	[TCM_INVALID_PARAMETER_LIST] = {
2812 		.key = ILLEGAL_REQUEST,
2813 		.asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
2814 	},
2815 	[TCM_TOO_MANY_TARGET_DESCS] = {
2816 		.key = ILLEGAL_REQUEST,
2817 		.asc = 0x26,
2818 		.ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
2819 	},
2820 	[TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
2821 		.key = ILLEGAL_REQUEST,
2822 		.asc = 0x26,
2823 		.ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
2824 	},
2825 	[TCM_TOO_MANY_SEGMENT_DESCS] = {
2826 		.key = ILLEGAL_REQUEST,
2827 		.asc = 0x26,
2828 		.ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
2829 	},
2830 	[TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
2831 		.key = ILLEGAL_REQUEST,
2832 		.asc = 0x26,
2833 		.ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
2834 	},
2835 	[TCM_PARAMETER_LIST_LENGTH_ERROR] = {
2836 		.key = ILLEGAL_REQUEST,
2837 		.asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
2838 	},
2839 	[TCM_UNEXPECTED_UNSOLICITED_DATA] = {
2840 		.key = ILLEGAL_REQUEST,
2841 		.asc = 0x0c, /* WRITE ERROR */
2842 		.ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
2843 	},
2844 	[TCM_SERVICE_CRC_ERROR] = {
2845 		.key = ABORTED_COMMAND,
2846 		.asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
2847 		.ascq = 0x05, /* N/A */
2848 	},
2849 	[TCM_SNACK_REJECTED] = {
2850 		.key = ABORTED_COMMAND,
2851 		.asc = 0x11, /* READ ERROR */
2852 		.ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
2853 	},
2854 	[TCM_WRITE_PROTECTED] = {
2855 		.key = DATA_PROTECT,
2856 		.asc = 0x27, /* WRITE PROTECTED */
2857 	},
2858 	[TCM_ADDRESS_OUT_OF_RANGE] = {
2859 		.key = ILLEGAL_REQUEST,
2860 		.asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2861 	},
2862 	[TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
2863 		.key = UNIT_ATTENTION,
2864 	},
2865 	[TCM_CHECK_CONDITION_NOT_READY] = {
2866 		.key = NOT_READY,
2867 	},
2868 	[TCM_MISCOMPARE_VERIFY] = {
2869 		.key = MISCOMPARE,
2870 		.asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
2871 		.ascq = 0x00,
2872 	},
2873 	[TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
2874 		.key = ABORTED_COMMAND,
2875 		.asc = 0x10,
2876 		.ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
2877 		.add_sector_info = true,
2878 	},
2879 	[TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
2880 		.key = ABORTED_COMMAND,
2881 		.asc = 0x10,
2882 		.ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2883 		.add_sector_info = true,
2884 	},
2885 	[TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
2886 		.key = ABORTED_COMMAND,
2887 		.asc = 0x10,
2888 		.ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2889 		.add_sector_info = true,
2890 	},
2891 	[TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
2892 		.key = COPY_ABORTED,
2893 		.asc = 0x0d,
2894 		.ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
2895 
2896 	},
2897 	[TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
2898 		/*
2899 		 * Returning ILLEGAL REQUEST would cause immediate IO errors on
2900 		 * Solaris initiators.  Returning NOT READY instead means the
2901 		 * operations will be retried a finite number of times and we
2902 		 * can survive intermittent errors.
2903 		 */
2904 		.key = NOT_READY,
2905 		.asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
2906 	},
2907 };
2908 
2909 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
2910 {
2911 	const struct sense_info *si;
2912 	u8 *buffer = cmd->sense_buffer;
2913 	int r = (__force int)reason;
2914 	u8 asc, ascq;
2915 	bool desc_format = target_sense_desc_format(cmd->se_dev);
2916 
2917 	if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
2918 		si = &sense_info_table[r];
2919 	else
2920 		si = &sense_info_table[(__force int)
2921 				       TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
2922 
2923 	if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
2924 		core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2925 		WARN_ON_ONCE(asc == 0);
2926 	} else if (si->asc == 0) {
2927 		WARN_ON_ONCE(cmd->scsi_asc == 0);
2928 		asc = cmd->scsi_asc;
2929 		ascq = cmd->scsi_ascq;
2930 	} else {
2931 		asc = si->asc;
2932 		ascq = si->ascq;
2933 	}
2934 
2935 	scsi_build_sense_buffer(desc_format, buffer, si->key, asc, ascq);
2936 	if (si->add_sector_info)
2937 		return scsi_set_sense_information(buffer,
2938 						  cmd->scsi_sense_length,
2939 						  cmd->bad_sector);
2940 
2941 	return 0;
2942 }
2943 
2944 int
2945 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2946 		sense_reason_t reason, int from_transport)
2947 {
2948 	unsigned long flags;
2949 
2950 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2951 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2952 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2953 		return 0;
2954 	}
2955 	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2956 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2957 
2958 	if (!from_transport) {
2959 		int rc;
2960 
2961 		cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2962 		cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2963 		cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2964 		rc = translate_sense_reason(cmd, reason);
2965 		if (rc)
2966 			return rc;
2967 	}
2968 
2969 	trace_target_cmd_complete(cmd);
2970 	return cmd->se_tfo->queue_status(cmd);
2971 }
2972 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2973 
2974 static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2975 	__releases(&cmd->t_state_lock)
2976 	__acquires(&cmd->t_state_lock)
2977 {
2978 	assert_spin_locked(&cmd->t_state_lock);
2979 	WARN_ON_ONCE(!irqs_disabled());
2980 
2981 	if (!(cmd->transport_state & CMD_T_ABORTED))
2982 		return 0;
2983 	/*
2984 	 * If cmd has been aborted but either no status is to be sent or it has
2985 	 * already been sent, just return
2986 	 */
2987 	if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS)) {
2988 		if (send_status)
2989 			cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
2990 		return 1;
2991 	}
2992 
2993 	pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB:"
2994 		" 0x%02x ITT: 0x%08llx\n", cmd->t_task_cdb[0], cmd->tag);
2995 
2996 	cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
2997 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2998 	trace_target_cmd_complete(cmd);
2999 
3000 	spin_unlock_irq(&cmd->t_state_lock);
3001 	cmd->se_tfo->queue_status(cmd);
3002 	spin_lock_irq(&cmd->t_state_lock);
3003 
3004 	return 1;
3005 }
3006 
3007 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3008 {
3009 	int ret;
3010 
3011 	spin_lock_irq(&cmd->t_state_lock);
3012 	ret = __transport_check_aborted_status(cmd, send_status);
3013 	spin_unlock_irq(&cmd->t_state_lock);
3014 
3015 	return ret;
3016 }
3017 EXPORT_SYMBOL(transport_check_aborted_status);
3018 
3019 void transport_send_task_abort(struct se_cmd *cmd)
3020 {
3021 	unsigned long flags;
3022 
3023 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3024 	if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
3025 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3026 		return;
3027 	}
3028 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3029 
3030 	/*
3031 	 * If there are still expected incoming fabric WRITEs, we wait
3032 	 * until until they have completed before sending a TASK_ABORTED
3033 	 * response.  This response with TASK_ABORTED status will be
3034 	 * queued back to fabric module by transport_check_aborted_status().
3035 	 */
3036 	if (cmd->data_direction == DMA_TO_DEVICE) {
3037 		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3038 			spin_lock_irqsave(&cmd->t_state_lock, flags);
3039 			if (cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS) {
3040 				spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3041 				goto send_abort;
3042 			}
3043 			cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3044 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3045 			return;
3046 		}
3047 	}
3048 send_abort:
3049 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3050 
3051 	transport_lun_remove_cmd(cmd);
3052 
3053 	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
3054 		 cmd->t_task_cdb[0], cmd->tag);
3055 
3056 	trace_target_cmd_complete(cmd);
3057 	cmd->se_tfo->queue_status(cmd);
3058 }
3059 
3060 static void target_tmr_work(struct work_struct *work)
3061 {
3062 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3063 	struct se_device *dev = cmd->se_dev;
3064 	struct se_tmr_req *tmr = cmd->se_tmr_req;
3065 	unsigned long flags;
3066 	int ret;
3067 
3068 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3069 	if (cmd->transport_state & CMD_T_ABORTED) {
3070 		tmr->response = TMR_FUNCTION_REJECTED;
3071 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3072 		goto check_stop;
3073 	}
3074 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3075 
3076 	switch (tmr->function) {
3077 	case TMR_ABORT_TASK:
3078 		core_tmr_abort_task(dev, tmr, cmd->se_sess);
3079 		break;
3080 	case TMR_ABORT_TASK_SET:
3081 	case TMR_CLEAR_ACA:
3082 	case TMR_CLEAR_TASK_SET:
3083 		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3084 		break;
3085 	case TMR_LUN_RESET:
3086 		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3087 		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3088 					 TMR_FUNCTION_REJECTED;
3089 		if (tmr->response == TMR_FUNCTION_COMPLETE) {
3090 			target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3091 					       cmd->orig_fe_lun, 0x29,
3092 					       ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3093 		}
3094 		break;
3095 	case TMR_TARGET_WARM_RESET:
3096 		tmr->response = TMR_FUNCTION_REJECTED;
3097 		break;
3098 	case TMR_TARGET_COLD_RESET:
3099 		tmr->response = TMR_FUNCTION_REJECTED;
3100 		break;
3101 	default:
3102 		pr_err("Uknown TMR function: 0x%02x.\n",
3103 				tmr->function);
3104 		tmr->response = TMR_FUNCTION_REJECTED;
3105 		break;
3106 	}
3107 
3108 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3109 	if (cmd->transport_state & CMD_T_ABORTED) {
3110 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3111 		goto check_stop;
3112 	}
3113 	cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3114 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3115 
3116 	cmd->se_tfo->queue_tm_rsp(cmd);
3117 
3118 check_stop:
3119 	transport_cmd_check_stop_to_fabric(cmd);
3120 }
3121 
3122 int transport_generic_handle_tmr(
3123 	struct se_cmd *cmd)
3124 {
3125 	unsigned long flags;
3126 
3127 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3128 	cmd->transport_state |= CMD_T_ACTIVE;
3129 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3130 
3131 	INIT_WORK(&cmd->work, target_tmr_work);
3132 	queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3133 	return 0;
3134 }
3135 EXPORT_SYMBOL(transport_generic_handle_tmr);
3136 
3137 bool
3138 target_check_wce(struct se_device *dev)
3139 {
3140 	bool wce = false;
3141 
3142 	if (dev->transport->get_write_cache)
3143 		wce = dev->transport->get_write_cache(dev);
3144 	else if (dev->dev_attrib.emulate_write_cache > 0)
3145 		wce = true;
3146 
3147 	return wce;
3148 }
3149 
3150 bool
3151 target_check_fua(struct se_device *dev)
3152 {
3153 	return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3154 }
3155