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 	kref_init(&se_sess->sess_kref);
243 	se_sess->sup_prot_ops = sup_prot_ops;
244 
245 	return se_sess;
246 }
247 EXPORT_SYMBOL(transport_init_session);
248 
249 int transport_alloc_session_tags(struct se_session *se_sess,
250 			         unsigned int tag_num, unsigned int tag_size)
251 {
252 	int rc;
253 
254 	se_sess->sess_cmd_map = kzalloc(tag_num * tag_size,
255 					GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
256 	if (!se_sess->sess_cmd_map) {
257 		se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
258 		if (!se_sess->sess_cmd_map) {
259 			pr_err("Unable to allocate se_sess->sess_cmd_map\n");
260 			return -ENOMEM;
261 		}
262 	}
263 
264 	rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
265 	if (rc < 0) {
266 		pr_err("Unable to init se_sess->sess_tag_pool,"
267 			" tag_num: %u\n", tag_num);
268 		kvfree(se_sess->sess_cmd_map);
269 		se_sess->sess_cmd_map = NULL;
270 		return -ENOMEM;
271 	}
272 
273 	return 0;
274 }
275 EXPORT_SYMBOL(transport_alloc_session_tags);
276 
277 struct se_session *transport_init_session_tags(unsigned int tag_num,
278 					       unsigned int tag_size,
279 					       enum target_prot_op sup_prot_ops)
280 {
281 	struct se_session *se_sess;
282 	int rc;
283 
284 	se_sess = transport_init_session(sup_prot_ops);
285 	if (IS_ERR(se_sess))
286 		return se_sess;
287 
288 	rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
289 	if (rc < 0) {
290 		transport_free_session(se_sess);
291 		return ERR_PTR(-ENOMEM);
292 	}
293 
294 	return se_sess;
295 }
296 EXPORT_SYMBOL(transport_init_session_tags);
297 
298 /*
299  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
300  */
301 void __transport_register_session(
302 	struct se_portal_group *se_tpg,
303 	struct se_node_acl *se_nacl,
304 	struct se_session *se_sess,
305 	void *fabric_sess_ptr)
306 {
307 	const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
308 	unsigned char buf[PR_REG_ISID_LEN];
309 
310 	se_sess->se_tpg = se_tpg;
311 	se_sess->fabric_sess_ptr = fabric_sess_ptr;
312 	/*
313 	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
314 	 *
315 	 * Only set for struct se_session's that will actually be moving I/O.
316 	 * eg: *NOT* discovery sessions.
317 	 */
318 	if (se_nacl) {
319 		/*
320 		 *
321 		 * Determine if fabric allows for T10-PI feature bits exposed to
322 		 * initiators for device backends with !dev->dev_attrib.pi_prot_type.
323 		 *
324 		 * If so, then always save prot_type on a per se_node_acl node
325 		 * basis and re-instate the previous sess_prot_type to avoid
326 		 * disabling PI from below any previously initiator side
327 		 * registered LUNs.
328 		 */
329 		if (se_nacl->saved_prot_type)
330 			se_sess->sess_prot_type = se_nacl->saved_prot_type;
331 		else if (tfo->tpg_check_prot_fabric_only)
332 			se_sess->sess_prot_type = se_nacl->saved_prot_type =
333 					tfo->tpg_check_prot_fabric_only(se_tpg);
334 		/*
335 		 * If the fabric module supports an ISID based TransportID,
336 		 * save this value in binary from the fabric I_T Nexus now.
337 		 */
338 		if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
339 			memset(&buf[0], 0, PR_REG_ISID_LEN);
340 			se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
341 					&buf[0], PR_REG_ISID_LEN);
342 			se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
343 		}
344 
345 		spin_lock_irq(&se_nacl->nacl_sess_lock);
346 		/*
347 		 * The se_nacl->nacl_sess pointer will be set to the
348 		 * last active I_T Nexus for each struct se_node_acl.
349 		 */
350 		se_nacl->nacl_sess = se_sess;
351 
352 		list_add_tail(&se_sess->sess_acl_list,
353 			      &se_nacl->acl_sess_list);
354 		spin_unlock_irq(&se_nacl->nacl_sess_lock);
355 	}
356 	list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
357 
358 	pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
359 		se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
360 }
361 EXPORT_SYMBOL(__transport_register_session);
362 
363 void transport_register_session(
364 	struct se_portal_group *se_tpg,
365 	struct se_node_acl *se_nacl,
366 	struct se_session *se_sess,
367 	void *fabric_sess_ptr)
368 {
369 	unsigned long flags;
370 
371 	spin_lock_irqsave(&se_tpg->session_lock, flags);
372 	__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
373 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
374 }
375 EXPORT_SYMBOL(transport_register_session);
376 
377 static void target_release_session(struct kref *kref)
378 {
379 	struct se_session *se_sess = container_of(kref,
380 			struct se_session, sess_kref);
381 	struct se_portal_group *se_tpg = se_sess->se_tpg;
382 
383 	se_tpg->se_tpg_tfo->close_session(se_sess);
384 }
385 
386 int target_get_session(struct se_session *se_sess)
387 {
388 	return kref_get_unless_zero(&se_sess->sess_kref);
389 }
390 EXPORT_SYMBOL(target_get_session);
391 
392 void target_put_session(struct se_session *se_sess)
393 {
394 	kref_put(&se_sess->sess_kref, target_release_session);
395 }
396 EXPORT_SYMBOL(target_put_session);
397 
398 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
399 {
400 	struct se_session *se_sess;
401 	ssize_t len = 0;
402 
403 	spin_lock_bh(&se_tpg->session_lock);
404 	list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
405 		if (!se_sess->se_node_acl)
406 			continue;
407 		if (!se_sess->se_node_acl->dynamic_node_acl)
408 			continue;
409 		if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
410 			break;
411 
412 		len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
413 				se_sess->se_node_acl->initiatorname);
414 		len += 1; /* Include NULL terminator */
415 	}
416 	spin_unlock_bh(&se_tpg->session_lock);
417 
418 	return len;
419 }
420 EXPORT_SYMBOL(target_show_dynamic_sessions);
421 
422 static void target_complete_nacl(struct kref *kref)
423 {
424 	struct se_node_acl *nacl = container_of(kref,
425 				struct se_node_acl, acl_kref);
426 
427 	complete(&nacl->acl_free_comp);
428 }
429 
430 void target_put_nacl(struct se_node_acl *nacl)
431 {
432 	kref_put(&nacl->acl_kref, target_complete_nacl);
433 }
434 EXPORT_SYMBOL(target_put_nacl);
435 
436 void transport_deregister_session_configfs(struct se_session *se_sess)
437 {
438 	struct se_node_acl *se_nacl;
439 	unsigned long flags;
440 	/*
441 	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
442 	 */
443 	se_nacl = se_sess->se_node_acl;
444 	if (se_nacl) {
445 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
446 		if (se_nacl->acl_stop == 0)
447 			list_del(&se_sess->sess_acl_list);
448 		/*
449 		 * If the session list is empty, then clear the pointer.
450 		 * Otherwise, set the struct se_session pointer from the tail
451 		 * element of the per struct se_node_acl active session list.
452 		 */
453 		if (list_empty(&se_nacl->acl_sess_list))
454 			se_nacl->nacl_sess = NULL;
455 		else {
456 			se_nacl->nacl_sess = container_of(
457 					se_nacl->acl_sess_list.prev,
458 					struct se_session, sess_acl_list);
459 		}
460 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
461 	}
462 }
463 EXPORT_SYMBOL(transport_deregister_session_configfs);
464 
465 void transport_free_session(struct se_session *se_sess)
466 {
467 	struct se_node_acl *se_nacl = se_sess->se_node_acl;
468 	/*
469 	 * Drop the se_node_acl->nacl_kref obtained from within
470 	 * core_tpg_get_initiator_node_acl().
471 	 */
472 	if (se_nacl) {
473 		se_sess->se_node_acl = NULL;
474 		target_put_nacl(se_nacl);
475 	}
476 	if (se_sess->sess_cmd_map) {
477 		percpu_ida_destroy(&se_sess->sess_tag_pool);
478 		kvfree(se_sess->sess_cmd_map);
479 	}
480 	kmem_cache_free(se_sess_cache, se_sess);
481 }
482 EXPORT_SYMBOL(transport_free_session);
483 
484 void transport_deregister_session(struct se_session *se_sess)
485 {
486 	struct se_portal_group *se_tpg = se_sess->se_tpg;
487 	const struct target_core_fabric_ops *se_tfo;
488 	struct se_node_acl *se_nacl;
489 	unsigned long flags;
490 	bool drop_nacl = false;
491 
492 	if (!se_tpg) {
493 		transport_free_session(se_sess);
494 		return;
495 	}
496 	se_tfo = se_tpg->se_tpg_tfo;
497 
498 	spin_lock_irqsave(&se_tpg->session_lock, flags);
499 	list_del(&se_sess->sess_list);
500 	se_sess->se_tpg = NULL;
501 	se_sess->fabric_sess_ptr = NULL;
502 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
503 
504 	/*
505 	 * Determine if we need to do extra work for this initiator node's
506 	 * struct se_node_acl if it had been previously dynamically generated.
507 	 */
508 	se_nacl = se_sess->se_node_acl;
509 
510 	mutex_lock(&se_tpg->acl_node_mutex);
511 	if (se_nacl && se_nacl->dynamic_node_acl) {
512 		if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
513 			list_del(&se_nacl->acl_list);
514 			drop_nacl = true;
515 		}
516 	}
517 	mutex_unlock(&se_tpg->acl_node_mutex);
518 
519 	if (drop_nacl) {
520 		core_tpg_wait_for_nacl_pr_ref(se_nacl);
521 		core_free_device_list_for_node(se_nacl, se_tpg);
522 		se_sess->se_node_acl = NULL;
523 		kfree(se_nacl);
524 	}
525 	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
526 		se_tpg->se_tpg_tfo->get_fabric_name());
527 	/*
528 	 * If last kref is dropping now for an explicit NodeACL, awake sleeping
529 	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
530 	 * removal context from within transport_free_session() code.
531 	 */
532 
533 	transport_free_session(se_sess);
534 }
535 EXPORT_SYMBOL(transport_deregister_session);
536 
537 static void target_remove_from_state_list(struct se_cmd *cmd)
538 {
539 	struct se_device *dev = cmd->se_dev;
540 	unsigned long flags;
541 
542 	if (!dev)
543 		return;
544 
545 	if (cmd->transport_state & CMD_T_BUSY)
546 		return;
547 
548 	spin_lock_irqsave(&dev->execute_task_lock, flags);
549 	if (cmd->state_active) {
550 		list_del(&cmd->state_list);
551 		cmd->state_active = false;
552 	}
553 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
554 }
555 
556 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
557 				    bool write_pending)
558 {
559 	unsigned long flags;
560 
561 	if (remove_from_lists) {
562 		target_remove_from_state_list(cmd);
563 
564 		/*
565 		 * Clear struct se_cmd->se_lun before the handoff to FE.
566 		 */
567 		cmd->se_lun = NULL;
568 	}
569 
570 	spin_lock_irqsave(&cmd->t_state_lock, flags);
571 	if (write_pending)
572 		cmd->t_state = TRANSPORT_WRITE_PENDING;
573 
574 	/*
575 	 * Determine if frontend context caller is requesting the stopping of
576 	 * this command for frontend exceptions.
577 	 */
578 	if (cmd->transport_state & CMD_T_STOP) {
579 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
580 			__func__, __LINE__, cmd->tag);
581 
582 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
583 
584 		complete_all(&cmd->t_transport_stop_comp);
585 		return 1;
586 	}
587 
588 	cmd->transport_state &= ~CMD_T_ACTIVE;
589 	if (remove_from_lists) {
590 		/*
591 		 * Some fabric modules like tcm_loop can release
592 		 * their internally allocated I/O reference now and
593 		 * struct se_cmd now.
594 		 *
595 		 * Fabric modules are expected to return '1' here if the
596 		 * se_cmd being passed is released at this point,
597 		 * or zero if not being released.
598 		 */
599 		if (cmd->se_tfo->check_stop_free != NULL) {
600 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
601 			return cmd->se_tfo->check_stop_free(cmd);
602 		}
603 	}
604 
605 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
606 	return 0;
607 }
608 
609 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
610 {
611 	return transport_cmd_check_stop(cmd, true, false);
612 }
613 
614 static void transport_lun_remove_cmd(struct se_cmd *cmd)
615 {
616 	struct se_lun *lun = cmd->se_lun;
617 
618 	if (!lun)
619 		return;
620 
621 	if (cmpxchg(&cmd->lun_ref_active, true, false))
622 		percpu_ref_put(&lun->lun_ref);
623 }
624 
625 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
626 {
627 	bool ack_kref = (cmd->se_cmd_flags & SCF_ACK_KREF);
628 
629 	if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
630 		transport_lun_remove_cmd(cmd);
631 	/*
632 	 * Allow the fabric driver to unmap any resources before
633 	 * releasing the descriptor via TFO->release_cmd()
634 	 */
635 	if (remove)
636 		cmd->se_tfo->aborted_task(cmd);
637 
638 	if (transport_cmd_check_stop_to_fabric(cmd))
639 		return;
640 	if (remove && ack_kref)
641 		transport_put_cmd(cmd);
642 }
643 
644 static void target_complete_failure_work(struct work_struct *work)
645 {
646 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
647 
648 	transport_generic_request_failure(cmd,
649 			TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
650 }
651 
652 /*
653  * Used when asking transport to copy Sense Data from the underlying
654  * Linux/SCSI struct scsi_cmnd
655  */
656 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
657 {
658 	struct se_device *dev = cmd->se_dev;
659 
660 	WARN_ON(!cmd->se_lun);
661 
662 	if (!dev)
663 		return NULL;
664 
665 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
666 		return NULL;
667 
668 	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
669 
670 	pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
671 		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
672 	return cmd->sense_buffer;
673 }
674 
675 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
676 {
677 	struct se_device *dev = cmd->se_dev;
678 	int success = scsi_status == GOOD;
679 	unsigned long flags;
680 
681 	cmd->scsi_status = scsi_status;
682 
683 
684 	spin_lock_irqsave(&cmd->t_state_lock, flags);
685 	cmd->transport_state &= ~CMD_T_BUSY;
686 
687 	if (dev && dev->transport->transport_complete) {
688 		dev->transport->transport_complete(cmd,
689 				cmd->t_data_sg,
690 				transport_get_sense_buffer(cmd));
691 		if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
692 			success = 1;
693 	}
694 
695 	/*
696 	 * See if we are waiting to complete for an exception condition.
697 	 */
698 	if (cmd->transport_state & CMD_T_REQUEST_STOP) {
699 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
700 		complete(&cmd->task_stop_comp);
701 		return;
702 	}
703 
704 	/*
705 	 * Check for case where an explicit ABORT_TASK has been received
706 	 * and transport_wait_for_tasks() will be waiting for completion..
707 	 */
708 	if (cmd->transport_state & CMD_T_ABORTED ||
709 	    cmd->transport_state & CMD_T_STOP) {
710 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
711 		complete_all(&cmd->t_transport_stop_comp);
712 		return;
713 	} else if (!success) {
714 		INIT_WORK(&cmd->work, target_complete_failure_work);
715 	} else {
716 		INIT_WORK(&cmd->work, target_complete_ok_work);
717 	}
718 
719 	cmd->t_state = TRANSPORT_COMPLETE;
720 	cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
721 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
722 
723 	if (cmd->cpuid == -1)
724 		queue_work(target_completion_wq, &cmd->work);
725 	else
726 		queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
727 }
728 EXPORT_SYMBOL(target_complete_cmd);
729 
730 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
731 {
732 	if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
733 		if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
734 			cmd->residual_count += cmd->data_length - length;
735 		} else {
736 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
737 			cmd->residual_count = cmd->data_length - length;
738 		}
739 
740 		cmd->data_length = length;
741 	}
742 
743 	target_complete_cmd(cmd, scsi_status);
744 }
745 EXPORT_SYMBOL(target_complete_cmd_with_length);
746 
747 static void target_add_to_state_list(struct se_cmd *cmd)
748 {
749 	struct se_device *dev = cmd->se_dev;
750 	unsigned long flags;
751 
752 	spin_lock_irqsave(&dev->execute_task_lock, flags);
753 	if (!cmd->state_active) {
754 		list_add_tail(&cmd->state_list, &dev->state_list);
755 		cmd->state_active = true;
756 	}
757 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
758 }
759 
760 /*
761  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
762  */
763 static void transport_write_pending_qf(struct se_cmd *cmd);
764 static void transport_complete_qf(struct se_cmd *cmd);
765 
766 void target_qf_do_work(struct work_struct *work)
767 {
768 	struct se_device *dev = container_of(work, struct se_device,
769 					qf_work_queue);
770 	LIST_HEAD(qf_cmd_list);
771 	struct se_cmd *cmd, *cmd_tmp;
772 
773 	spin_lock_irq(&dev->qf_cmd_lock);
774 	list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
775 	spin_unlock_irq(&dev->qf_cmd_lock);
776 
777 	list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
778 		list_del(&cmd->se_qf_node);
779 		atomic_dec_mb(&dev->dev_qf_count);
780 
781 		pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
782 			" context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
783 			(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
784 			(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
785 			: "UNKNOWN");
786 
787 		if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
788 			transport_write_pending_qf(cmd);
789 		else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
790 			transport_complete_qf(cmd);
791 	}
792 }
793 
794 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
795 {
796 	switch (cmd->data_direction) {
797 	case DMA_NONE:
798 		return "NONE";
799 	case DMA_FROM_DEVICE:
800 		return "READ";
801 	case DMA_TO_DEVICE:
802 		return "WRITE";
803 	case DMA_BIDIRECTIONAL:
804 		return "BIDI";
805 	default:
806 		break;
807 	}
808 
809 	return "UNKNOWN";
810 }
811 
812 void transport_dump_dev_state(
813 	struct se_device *dev,
814 	char *b,
815 	int *bl)
816 {
817 	*bl += sprintf(b + *bl, "Status: ");
818 	if (dev->export_count)
819 		*bl += sprintf(b + *bl, "ACTIVATED");
820 	else
821 		*bl += sprintf(b + *bl, "DEACTIVATED");
822 
823 	*bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
824 	*bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
825 		dev->dev_attrib.block_size,
826 		dev->dev_attrib.hw_max_sectors);
827 	*bl += sprintf(b + *bl, "        ");
828 }
829 
830 void transport_dump_vpd_proto_id(
831 	struct t10_vpd *vpd,
832 	unsigned char *p_buf,
833 	int p_buf_len)
834 {
835 	unsigned char buf[VPD_TMP_BUF_SIZE];
836 	int len;
837 
838 	memset(buf, 0, VPD_TMP_BUF_SIZE);
839 	len = sprintf(buf, "T10 VPD Protocol Identifier: ");
840 
841 	switch (vpd->protocol_identifier) {
842 	case 0x00:
843 		sprintf(buf+len, "Fibre Channel\n");
844 		break;
845 	case 0x10:
846 		sprintf(buf+len, "Parallel SCSI\n");
847 		break;
848 	case 0x20:
849 		sprintf(buf+len, "SSA\n");
850 		break;
851 	case 0x30:
852 		sprintf(buf+len, "IEEE 1394\n");
853 		break;
854 	case 0x40:
855 		sprintf(buf+len, "SCSI Remote Direct Memory Access"
856 				" Protocol\n");
857 		break;
858 	case 0x50:
859 		sprintf(buf+len, "Internet SCSI (iSCSI)\n");
860 		break;
861 	case 0x60:
862 		sprintf(buf+len, "SAS Serial SCSI Protocol\n");
863 		break;
864 	case 0x70:
865 		sprintf(buf+len, "Automation/Drive Interface Transport"
866 				" Protocol\n");
867 		break;
868 	case 0x80:
869 		sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
870 		break;
871 	default:
872 		sprintf(buf+len, "Unknown 0x%02x\n",
873 				vpd->protocol_identifier);
874 		break;
875 	}
876 
877 	if (p_buf)
878 		strncpy(p_buf, buf, p_buf_len);
879 	else
880 		pr_debug("%s", buf);
881 }
882 
883 void
884 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
885 {
886 	/*
887 	 * Check if the Protocol Identifier Valid (PIV) bit is set..
888 	 *
889 	 * from spc3r23.pdf section 7.5.1
890 	 */
891 	 if (page_83[1] & 0x80) {
892 		vpd->protocol_identifier = (page_83[0] & 0xf0);
893 		vpd->protocol_identifier_set = 1;
894 		transport_dump_vpd_proto_id(vpd, NULL, 0);
895 	}
896 }
897 EXPORT_SYMBOL(transport_set_vpd_proto_id);
898 
899 int transport_dump_vpd_assoc(
900 	struct t10_vpd *vpd,
901 	unsigned char *p_buf,
902 	int p_buf_len)
903 {
904 	unsigned char buf[VPD_TMP_BUF_SIZE];
905 	int ret = 0;
906 	int len;
907 
908 	memset(buf, 0, VPD_TMP_BUF_SIZE);
909 	len = sprintf(buf, "T10 VPD Identifier Association: ");
910 
911 	switch (vpd->association) {
912 	case 0x00:
913 		sprintf(buf+len, "addressed logical unit\n");
914 		break;
915 	case 0x10:
916 		sprintf(buf+len, "target port\n");
917 		break;
918 	case 0x20:
919 		sprintf(buf+len, "SCSI target device\n");
920 		break;
921 	default:
922 		sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
923 		ret = -EINVAL;
924 		break;
925 	}
926 
927 	if (p_buf)
928 		strncpy(p_buf, buf, p_buf_len);
929 	else
930 		pr_debug("%s", buf);
931 
932 	return ret;
933 }
934 
935 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
936 {
937 	/*
938 	 * The VPD identification association..
939 	 *
940 	 * from spc3r23.pdf Section 7.6.3.1 Table 297
941 	 */
942 	vpd->association = (page_83[1] & 0x30);
943 	return transport_dump_vpd_assoc(vpd, NULL, 0);
944 }
945 EXPORT_SYMBOL(transport_set_vpd_assoc);
946 
947 int transport_dump_vpd_ident_type(
948 	struct t10_vpd *vpd,
949 	unsigned char *p_buf,
950 	int p_buf_len)
951 {
952 	unsigned char buf[VPD_TMP_BUF_SIZE];
953 	int ret = 0;
954 	int len;
955 
956 	memset(buf, 0, VPD_TMP_BUF_SIZE);
957 	len = sprintf(buf, "T10 VPD Identifier Type: ");
958 
959 	switch (vpd->device_identifier_type) {
960 	case 0x00:
961 		sprintf(buf+len, "Vendor specific\n");
962 		break;
963 	case 0x01:
964 		sprintf(buf+len, "T10 Vendor ID based\n");
965 		break;
966 	case 0x02:
967 		sprintf(buf+len, "EUI-64 based\n");
968 		break;
969 	case 0x03:
970 		sprintf(buf+len, "NAA\n");
971 		break;
972 	case 0x04:
973 		sprintf(buf+len, "Relative target port identifier\n");
974 		break;
975 	case 0x08:
976 		sprintf(buf+len, "SCSI name string\n");
977 		break;
978 	default:
979 		sprintf(buf+len, "Unsupported: 0x%02x\n",
980 				vpd->device_identifier_type);
981 		ret = -EINVAL;
982 		break;
983 	}
984 
985 	if (p_buf) {
986 		if (p_buf_len < strlen(buf)+1)
987 			return -EINVAL;
988 		strncpy(p_buf, buf, p_buf_len);
989 	} else {
990 		pr_debug("%s", buf);
991 	}
992 
993 	return ret;
994 }
995 
996 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
997 {
998 	/*
999 	 * The VPD identifier type..
1000 	 *
1001 	 * from spc3r23.pdf Section 7.6.3.1 Table 298
1002 	 */
1003 	vpd->device_identifier_type = (page_83[1] & 0x0f);
1004 	return transport_dump_vpd_ident_type(vpd, NULL, 0);
1005 }
1006 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1007 
1008 int transport_dump_vpd_ident(
1009 	struct t10_vpd *vpd,
1010 	unsigned char *p_buf,
1011 	int p_buf_len)
1012 {
1013 	unsigned char buf[VPD_TMP_BUF_SIZE];
1014 	int ret = 0;
1015 
1016 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1017 
1018 	switch (vpd->device_identifier_code_set) {
1019 	case 0x01: /* Binary */
1020 		snprintf(buf, sizeof(buf),
1021 			"T10 VPD Binary Device Identifier: %s\n",
1022 			&vpd->device_identifier[0]);
1023 		break;
1024 	case 0x02: /* ASCII */
1025 		snprintf(buf, sizeof(buf),
1026 			"T10 VPD ASCII Device Identifier: %s\n",
1027 			&vpd->device_identifier[0]);
1028 		break;
1029 	case 0x03: /* UTF-8 */
1030 		snprintf(buf, sizeof(buf),
1031 			"T10 VPD UTF-8 Device Identifier: %s\n",
1032 			&vpd->device_identifier[0]);
1033 		break;
1034 	default:
1035 		sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1036 			" 0x%02x", vpd->device_identifier_code_set);
1037 		ret = -EINVAL;
1038 		break;
1039 	}
1040 
1041 	if (p_buf)
1042 		strncpy(p_buf, buf, p_buf_len);
1043 	else
1044 		pr_debug("%s", buf);
1045 
1046 	return ret;
1047 }
1048 
1049 int
1050 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1051 {
1052 	static const char hex_str[] = "0123456789abcdef";
1053 	int j = 0, i = 4; /* offset to start of the identifier */
1054 
1055 	/*
1056 	 * The VPD Code Set (encoding)
1057 	 *
1058 	 * from spc3r23.pdf Section 7.6.3.1 Table 296
1059 	 */
1060 	vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1061 	switch (vpd->device_identifier_code_set) {
1062 	case 0x01: /* Binary */
1063 		vpd->device_identifier[j++] =
1064 				hex_str[vpd->device_identifier_type];
1065 		while (i < (4 + page_83[3])) {
1066 			vpd->device_identifier[j++] =
1067 				hex_str[(page_83[i] & 0xf0) >> 4];
1068 			vpd->device_identifier[j++] =
1069 				hex_str[page_83[i] & 0x0f];
1070 			i++;
1071 		}
1072 		break;
1073 	case 0x02: /* ASCII */
1074 	case 0x03: /* UTF-8 */
1075 		while (i < (4 + page_83[3]))
1076 			vpd->device_identifier[j++] = page_83[i++];
1077 		break;
1078 	default:
1079 		break;
1080 	}
1081 
1082 	return transport_dump_vpd_ident(vpd, NULL, 0);
1083 }
1084 EXPORT_SYMBOL(transport_set_vpd_ident);
1085 
1086 static sense_reason_t
1087 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1088 			       unsigned int size)
1089 {
1090 	u32 mtl;
1091 
1092 	if (!cmd->se_tfo->max_data_sg_nents)
1093 		return TCM_NO_SENSE;
1094 	/*
1095 	 * Check if fabric enforced maximum SGL entries per I/O descriptor
1096 	 * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1097 	 * residual_count and reduce original cmd->data_length to maximum
1098 	 * length based on single PAGE_SIZE entry scatter-lists.
1099 	 */
1100 	mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1101 	if (cmd->data_length > mtl) {
1102 		/*
1103 		 * If an existing CDB overflow is present, calculate new residual
1104 		 * based on CDB size minus fabric maximum transfer length.
1105 		 *
1106 		 * If an existing CDB underflow is present, calculate new residual
1107 		 * based on original cmd->data_length minus fabric maximum transfer
1108 		 * length.
1109 		 *
1110 		 * Otherwise, set the underflow residual based on cmd->data_length
1111 		 * minus fabric maximum transfer length.
1112 		 */
1113 		if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1114 			cmd->residual_count = (size - mtl);
1115 		} else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1116 			u32 orig_dl = size + cmd->residual_count;
1117 			cmd->residual_count = (orig_dl - mtl);
1118 		} else {
1119 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1120 			cmd->residual_count = (cmd->data_length - mtl);
1121 		}
1122 		cmd->data_length = mtl;
1123 		/*
1124 		 * Reset sbc_check_prot() calculated protection payload
1125 		 * length based upon the new smaller MTL.
1126 		 */
1127 		if (cmd->prot_length) {
1128 			u32 sectors = (mtl / dev->dev_attrib.block_size);
1129 			cmd->prot_length = dev->prot_length * sectors;
1130 		}
1131 	}
1132 	return TCM_NO_SENSE;
1133 }
1134 
1135 sense_reason_t
1136 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1137 {
1138 	struct se_device *dev = cmd->se_dev;
1139 
1140 	if (cmd->unknown_data_length) {
1141 		cmd->data_length = size;
1142 	} else if (size != cmd->data_length) {
1143 		pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1144 			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
1145 			" 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1146 				cmd->data_length, size, cmd->t_task_cdb[0]);
1147 
1148 		if (cmd->data_direction == DMA_TO_DEVICE &&
1149 		    cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1150 			pr_err("Rejecting underflow/overflow WRITE data\n");
1151 			return TCM_INVALID_CDB_FIELD;
1152 		}
1153 		/*
1154 		 * Reject READ_* or WRITE_* with overflow/underflow for
1155 		 * type SCF_SCSI_DATA_CDB.
1156 		 */
1157 		if (dev->dev_attrib.block_size != 512)  {
1158 			pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1159 				" CDB on non 512-byte sector setup subsystem"
1160 				" plugin: %s\n", dev->transport->name);
1161 			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1162 			return TCM_INVALID_CDB_FIELD;
1163 		}
1164 		/*
1165 		 * For the overflow case keep the existing fabric provided
1166 		 * ->data_length.  Otherwise for the underflow case, reset
1167 		 * ->data_length to the smaller SCSI expected data transfer
1168 		 * length.
1169 		 */
1170 		if (size > cmd->data_length) {
1171 			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1172 			cmd->residual_count = (size - cmd->data_length);
1173 		} else {
1174 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1175 			cmd->residual_count = (cmd->data_length - size);
1176 			cmd->data_length = size;
1177 		}
1178 	}
1179 
1180 	return target_check_max_data_sg_nents(cmd, dev, size);
1181 
1182 }
1183 
1184 /*
1185  * Used by fabric modules containing a local struct se_cmd within their
1186  * fabric dependent per I/O descriptor.
1187  *
1188  * Preserves the value of @cmd->tag.
1189  */
1190 void transport_init_se_cmd(
1191 	struct se_cmd *cmd,
1192 	const struct target_core_fabric_ops *tfo,
1193 	struct se_session *se_sess,
1194 	u32 data_length,
1195 	int data_direction,
1196 	int task_attr,
1197 	unsigned char *sense_buffer)
1198 {
1199 	INIT_LIST_HEAD(&cmd->se_delayed_node);
1200 	INIT_LIST_HEAD(&cmd->se_qf_node);
1201 	INIT_LIST_HEAD(&cmd->se_cmd_list);
1202 	INIT_LIST_HEAD(&cmd->state_list);
1203 	init_completion(&cmd->t_transport_stop_comp);
1204 	init_completion(&cmd->cmd_wait_comp);
1205 	init_completion(&cmd->task_stop_comp);
1206 	spin_lock_init(&cmd->t_state_lock);
1207 	kref_init(&cmd->cmd_kref);
1208 	cmd->transport_state = CMD_T_DEV_ACTIVE;
1209 
1210 	cmd->se_tfo = tfo;
1211 	cmd->se_sess = se_sess;
1212 	cmd->data_length = data_length;
1213 	cmd->data_direction = data_direction;
1214 	cmd->sam_task_attr = task_attr;
1215 	cmd->sense_buffer = sense_buffer;
1216 
1217 	cmd->state_active = false;
1218 }
1219 EXPORT_SYMBOL(transport_init_se_cmd);
1220 
1221 static sense_reason_t
1222 transport_check_alloc_task_attr(struct se_cmd *cmd)
1223 {
1224 	struct se_device *dev = cmd->se_dev;
1225 
1226 	/*
1227 	 * Check if SAM Task Attribute emulation is enabled for this
1228 	 * struct se_device storage object
1229 	 */
1230 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1231 		return 0;
1232 
1233 	if (cmd->sam_task_attr == TCM_ACA_TAG) {
1234 		pr_debug("SAM Task Attribute ACA"
1235 			" emulation is not supported\n");
1236 		return TCM_INVALID_CDB_FIELD;
1237 	}
1238 
1239 	return 0;
1240 }
1241 
1242 sense_reason_t
1243 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1244 {
1245 	struct se_device *dev = cmd->se_dev;
1246 	sense_reason_t ret;
1247 
1248 	/*
1249 	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1250 	 * for VARIABLE_LENGTH_CMD
1251 	 */
1252 	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1253 		pr_err("Received SCSI CDB with command_size: %d that"
1254 			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1255 			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1256 		return TCM_INVALID_CDB_FIELD;
1257 	}
1258 	/*
1259 	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1260 	 * allocate the additional extended CDB buffer now..  Otherwise
1261 	 * setup the pointer from __t_task_cdb to t_task_cdb.
1262 	 */
1263 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1264 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1265 						GFP_KERNEL);
1266 		if (!cmd->t_task_cdb) {
1267 			pr_err("Unable to allocate cmd->t_task_cdb"
1268 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1269 				scsi_command_size(cdb),
1270 				(unsigned long)sizeof(cmd->__t_task_cdb));
1271 			return TCM_OUT_OF_RESOURCES;
1272 		}
1273 	} else
1274 		cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1275 	/*
1276 	 * Copy the original CDB into cmd->
1277 	 */
1278 	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1279 
1280 	trace_target_sequencer_start(cmd);
1281 
1282 	/*
1283 	 * Check for an existing UNIT ATTENTION condition
1284 	 */
1285 	ret = target_scsi3_ua_check(cmd);
1286 	if (ret)
1287 		return ret;
1288 
1289 	ret = target_alua_state_check(cmd);
1290 	if (ret)
1291 		return ret;
1292 
1293 	ret = target_check_reservation(cmd);
1294 	if (ret) {
1295 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1296 		return ret;
1297 	}
1298 
1299 	ret = dev->transport->parse_cdb(cmd);
1300 	if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1301 		pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1302 				    cmd->se_tfo->get_fabric_name(),
1303 				    cmd->se_sess->se_node_acl->initiatorname,
1304 				    cmd->t_task_cdb[0]);
1305 	if (ret)
1306 		return ret;
1307 
1308 	ret = transport_check_alloc_task_attr(cmd);
1309 	if (ret)
1310 		return ret;
1311 
1312 	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1313 	atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1314 	return 0;
1315 }
1316 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1317 
1318 /*
1319  * Used by fabric module frontends to queue tasks directly.
1320  * May only be used from process context.
1321  */
1322 int transport_handle_cdb_direct(
1323 	struct se_cmd *cmd)
1324 {
1325 	sense_reason_t ret;
1326 
1327 	if (!cmd->se_lun) {
1328 		dump_stack();
1329 		pr_err("cmd->se_lun is NULL\n");
1330 		return -EINVAL;
1331 	}
1332 	if (in_interrupt()) {
1333 		dump_stack();
1334 		pr_err("transport_generic_handle_cdb cannot be called"
1335 				" from interrupt context\n");
1336 		return -EINVAL;
1337 	}
1338 	/*
1339 	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1340 	 * outstanding descriptors are handled correctly during shutdown via
1341 	 * transport_wait_for_tasks()
1342 	 *
1343 	 * Also, we don't take cmd->t_state_lock here as we only expect
1344 	 * this to be called for initial descriptor submission.
1345 	 */
1346 	cmd->t_state = TRANSPORT_NEW_CMD;
1347 	cmd->transport_state |= CMD_T_ACTIVE;
1348 
1349 	/*
1350 	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1351 	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1352 	 * and call transport_generic_request_failure() if necessary..
1353 	 */
1354 	ret = transport_generic_new_cmd(cmd);
1355 	if (ret)
1356 		transport_generic_request_failure(cmd, ret);
1357 	return 0;
1358 }
1359 EXPORT_SYMBOL(transport_handle_cdb_direct);
1360 
1361 sense_reason_t
1362 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1363 		u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1364 {
1365 	if (!sgl || !sgl_count)
1366 		return 0;
1367 
1368 	/*
1369 	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1370 	 * scatterlists already have been set to follow what the fabric
1371 	 * passes for the original expected data transfer length.
1372 	 */
1373 	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1374 		pr_warn("Rejecting SCSI DATA overflow for fabric using"
1375 			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1376 		return TCM_INVALID_CDB_FIELD;
1377 	}
1378 
1379 	cmd->t_data_sg = sgl;
1380 	cmd->t_data_nents = sgl_count;
1381 	cmd->t_bidi_data_sg = sgl_bidi;
1382 	cmd->t_bidi_data_nents = sgl_bidi_count;
1383 
1384 	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1385 	return 0;
1386 }
1387 
1388 /*
1389  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1390  * 			 se_cmd + use pre-allocated SGL memory.
1391  *
1392  * @se_cmd: command descriptor to submit
1393  * @se_sess: associated se_sess for endpoint
1394  * @cdb: pointer to SCSI CDB
1395  * @sense: pointer to SCSI sense buffer
1396  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1397  * @data_length: fabric expected data transfer length
1398  * @task_addr: SAM task attribute
1399  * @data_dir: DMA data direction
1400  * @flags: flags for command submission from target_sc_flags_tables
1401  * @sgl: struct scatterlist memory for unidirectional mapping
1402  * @sgl_count: scatterlist count for unidirectional mapping
1403  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1404  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1405  * @sgl_prot: struct scatterlist memory protection information
1406  * @sgl_prot_count: scatterlist count for protection information
1407  *
1408  * Task tags are supported if the caller has set @se_cmd->tag.
1409  *
1410  * Returns non zero to signal active I/O shutdown failure.  All other
1411  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1412  * but still return zero here.
1413  *
1414  * This may only be called from process context, and also currently
1415  * assumes internal allocation of fabric payload buffer by target-core.
1416  */
1417 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1418 		unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1419 		u32 data_length, int task_attr, int data_dir, int flags,
1420 		struct scatterlist *sgl, u32 sgl_count,
1421 		struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1422 		struct scatterlist *sgl_prot, u32 sgl_prot_count)
1423 {
1424 	struct se_portal_group *se_tpg;
1425 	sense_reason_t rc;
1426 	int ret;
1427 
1428 	se_tpg = se_sess->se_tpg;
1429 	BUG_ON(!se_tpg);
1430 	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1431 	BUG_ON(in_interrupt());
1432 	/*
1433 	 * Initialize se_cmd for target operation.  From this point
1434 	 * exceptions are handled by sending exception status via
1435 	 * target_core_fabric_ops->queue_status() callback
1436 	 */
1437 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1438 				data_length, data_dir, task_attr, sense);
1439 	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1440 		se_cmd->unknown_data_length = 1;
1441 	/*
1442 	 * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1443 	 * se_sess->sess_cmd_list.  A second kref_get here is necessary
1444 	 * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1445 	 * kref_put() to happen during fabric packet acknowledgement.
1446 	 */
1447 	ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1448 	if (ret)
1449 		return ret;
1450 	/*
1451 	 * Signal bidirectional data payloads to target-core
1452 	 */
1453 	if (flags & TARGET_SCF_BIDI_OP)
1454 		se_cmd->se_cmd_flags |= SCF_BIDI;
1455 	/*
1456 	 * Locate se_lun pointer and attach it to struct se_cmd
1457 	 */
1458 	rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1459 	if (rc) {
1460 		transport_send_check_condition_and_sense(se_cmd, rc, 0);
1461 		target_put_sess_cmd(se_cmd);
1462 		return 0;
1463 	}
1464 
1465 	rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1466 	if (rc != 0) {
1467 		transport_generic_request_failure(se_cmd, rc);
1468 		return 0;
1469 	}
1470 
1471 	/*
1472 	 * Save pointers for SGLs containing protection information,
1473 	 * if present.
1474 	 */
1475 	if (sgl_prot_count) {
1476 		se_cmd->t_prot_sg = sgl_prot;
1477 		se_cmd->t_prot_nents = sgl_prot_count;
1478 		se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1479 	}
1480 
1481 	/*
1482 	 * When a non zero sgl_count has been passed perform SGL passthrough
1483 	 * mapping for pre-allocated fabric memory instead of having target
1484 	 * core perform an internal SGL allocation..
1485 	 */
1486 	if (sgl_count != 0) {
1487 		BUG_ON(!sgl);
1488 
1489 		/*
1490 		 * A work-around for tcm_loop as some userspace code via
1491 		 * scsi-generic do not memset their associated read buffers,
1492 		 * so go ahead and do that here for type non-data CDBs.  Also
1493 		 * note that this is currently guaranteed to be a single SGL
1494 		 * for this case by target core in target_setup_cmd_from_cdb()
1495 		 * -> transport_generic_cmd_sequencer().
1496 		 */
1497 		if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1498 		     se_cmd->data_direction == DMA_FROM_DEVICE) {
1499 			unsigned char *buf = NULL;
1500 
1501 			if (sgl)
1502 				buf = kmap(sg_page(sgl)) + sgl->offset;
1503 
1504 			if (buf) {
1505 				memset(buf, 0, sgl->length);
1506 				kunmap(sg_page(sgl));
1507 			}
1508 		}
1509 
1510 		rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1511 				sgl_bidi, sgl_bidi_count);
1512 		if (rc != 0) {
1513 			transport_generic_request_failure(se_cmd, rc);
1514 			return 0;
1515 		}
1516 	}
1517 
1518 	/*
1519 	 * Check if we need to delay processing because of ALUA
1520 	 * Active/NonOptimized primary access state..
1521 	 */
1522 	core_alua_check_nonop_delay(se_cmd);
1523 
1524 	transport_handle_cdb_direct(se_cmd);
1525 	return 0;
1526 }
1527 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1528 
1529 /*
1530  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1531  *
1532  * @se_cmd: command descriptor to submit
1533  * @se_sess: associated se_sess for endpoint
1534  * @cdb: pointer to SCSI CDB
1535  * @sense: pointer to SCSI sense buffer
1536  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1537  * @data_length: fabric expected data transfer length
1538  * @task_addr: SAM task attribute
1539  * @data_dir: DMA data direction
1540  * @flags: flags for command submission from target_sc_flags_tables
1541  *
1542  * Task tags are supported if the caller has set @se_cmd->tag.
1543  *
1544  * Returns non zero to signal active I/O shutdown failure.  All other
1545  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1546  * but still return zero here.
1547  *
1548  * This may only be called from process context, and also currently
1549  * assumes internal allocation of fabric payload buffer by target-core.
1550  *
1551  * It also assumes interal target core SGL memory allocation.
1552  */
1553 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1554 		unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1555 		u32 data_length, int task_attr, int data_dir, int flags)
1556 {
1557 	return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1558 			unpacked_lun, data_length, task_attr, data_dir,
1559 			flags, NULL, 0, NULL, 0, NULL, 0);
1560 }
1561 EXPORT_SYMBOL(target_submit_cmd);
1562 
1563 static void target_complete_tmr_failure(struct work_struct *work)
1564 {
1565 	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1566 
1567 	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1568 	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1569 
1570 	transport_cmd_check_stop_to_fabric(se_cmd);
1571 }
1572 
1573 /**
1574  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1575  *                     for TMR CDBs
1576  *
1577  * @se_cmd: command descriptor to submit
1578  * @se_sess: associated se_sess for endpoint
1579  * @sense: pointer to SCSI sense buffer
1580  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1581  * @fabric_context: fabric context for TMR req
1582  * @tm_type: Type of TM request
1583  * @gfp: gfp type for caller
1584  * @tag: referenced task tag for TMR_ABORT_TASK
1585  * @flags: submit cmd flags
1586  *
1587  * Callable from all contexts.
1588  **/
1589 
1590 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1591 		unsigned char *sense, u64 unpacked_lun,
1592 		void *fabric_tmr_ptr, unsigned char tm_type,
1593 		gfp_t gfp, u64 tag, int flags)
1594 {
1595 	struct se_portal_group *se_tpg;
1596 	int ret;
1597 
1598 	se_tpg = se_sess->se_tpg;
1599 	BUG_ON(!se_tpg);
1600 
1601 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1602 			      0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1603 	/*
1604 	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1605 	 * allocation failure.
1606 	 */
1607 	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1608 	if (ret < 0)
1609 		return -ENOMEM;
1610 
1611 	if (tm_type == TMR_ABORT_TASK)
1612 		se_cmd->se_tmr_req->ref_task_tag = tag;
1613 
1614 	/* See target_submit_cmd for commentary */
1615 	ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1616 	if (ret) {
1617 		core_tmr_release_req(se_cmd->se_tmr_req);
1618 		return ret;
1619 	}
1620 
1621 	ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1622 	if (ret) {
1623 		/*
1624 		 * For callback during failure handling, push this work off
1625 		 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1626 		 */
1627 		INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1628 		schedule_work(&se_cmd->work);
1629 		return 0;
1630 	}
1631 	transport_generic_handle_tmr(se_cmd);
1632 	return 0;
1633 }
1634 EXPORT_SYMBOL(target_submit_tmr);
1635 
1636 /*
1637  * If the cmd is active, request it to be stopped and sleep until it
1638  * has completed.
1639  */
1640 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1641 	__releases(&cmd->t_state_lock)
1642 	__acquires(&cmd->t_state_lock)
1643 {
1644 	bool was_active = false;
1645 
1646 	if (cmd->transport_state & CMD_T_BUSY) {
1647 		cmd->transport_state |= CMD_T_REQUEST_STOP;
1648 		spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1649 
1650 		pr_debug("cmd %p waiting to complete\n", cmd);
1651 		wait_for_completion(&cmd->task_stop_comp);
1652 		pr_debug("cmd %p stopped successfully\n", cmd);
1653 
1654 		spin_lock_irqsave(&cmd->t_state_lock, *flags);
1655 		cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1656 		cmd->transport_state &= ~CMD_T_BUSY;
1657 		was_active = true;
1658 	}
1659 
1660 	return was_active;
1661 }
1662 
1663 /*
1664  * Handle SAM-esque emulation for generic transport request failures.
1665  */
1666 void transport_generic_request_failure(struct se_cmd *cmd,
1667 		sense_reason_t sense_reason)
1668 {
1669 	int ret = 0, post_ret = 0;
1670 
1671 	pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08llx"
1672 		" CDB: 0x%02x\n", cmd, cmd->tag, cmd->t_task_cdb[0]);
1673 	pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1674 		cmd->se_tfo->get_cmd_state(cmd),
1675 		cmd->t_state, sense_reason);
1676 	pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1677 		(cmd->transport_state & CMD_T_ACTIVE) != 0,
1678 		(cmd->transport_state & CMD_T_STOP) != 0,
1679 		(cmd->transport_state & CMD_T_SENT) != 0);
1680 
1681 	/*
1682 	 * For SAM Task Attribute emulation for failed struct se_cmd
1683 	 */
1684 	transport_complete_task_attr(cmd);
1685 	/*
1686 	 * Handle special case for COMPARE_AND_WRITE failure, where the
1687 	 * callback is expected to drop the per device ->caw_sem.
1688 	 */
1689 	if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1690 	     cmd->transport_complete_callback)
1691 		cmd->transport_complete_callback(cmd, false, &post_ret);
1692 
1693 	switch (sense_reason) {
1694 	case TCM_NON_EXISTENT_LUN:
1695 	case TCM_UNSUPPORTED_SCSI_OPCODE:
1696 	case TCM_INVALID_CDB_FIELD:
1697 	case TCM_INVALID_PARAMETER_LIST:
1698 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
1699 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1700 	case TCM_UNKNOWN_MODE_PAGE:
1701 	case TCM_WRITE_PROTECTED:
1702 	case TCM_ADDRESS_OUT_OF_RANGE:
1703 	case TCM_CHECK_CONDITION_ABORT_CMD:
1704 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1705 	case TCM_CHECK_CONDITION_NOT_READY:
1706 	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1707 	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1708 	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1709 		break;
1710 	case TCM_OUT_OF_RESOURCES:
1711 		sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1712 		break;
1713 	case TCM_RESERVATION_CONFLICT:
1714 		/*
1715 		 * No SENSE Data payload for this case, set SCSI Status
1716 		 * and queue the response to $FABRIC_MOD.
1717 		 *
1718 		 * Uses linux/include/scsi/scsi.h SAM status codes defs
1719 		 */
1720 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1721 		/*
1722 		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1723 		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1724 		 * CONFLICT STATUS.
1725 		 *
1726 		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1727 		 */
1728 		if (cmd->se_sess &&
1729 		    cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1730 			target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1731 					       cmd->orig_fe_lun, 0x2C,
1732 					ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1733 		}
1734 		trace_target_cmd_complete(cmd);
1735 		ret = cmd->se_tfo->queue_status(cmd);
1736 		if (ret == -EAGAIN || ret == -ENOMEM)
1737 			goto queue_full;
1738 		goto check_stop;
1739 	default:
1740 		pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1741 			cmd->t_task_cdb[0], sense_reason);
1742 		sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1743 		break;
1744 	}
1745 
1746 	ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1747 	if (ret == -EAGAIN || ret == -ENOMEM)
1748 		goto queue_full;
1749 
1750 check_stop:
1751 	transport_lun_remove_cmd(cmd);
1752 	transport_cmd_check_stop_to_fabric(cmd);
1753 	return;
1754 
1755 queue_full:
1756 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1757 	transport_handle_queue_full(cmd, cmd->se_dev);
1758 }
1759 EXPORT_SYMBOL(transport_generic_request_failure);
1760 
1761 void __target_execute_cmd(struct se_cmd *cmd)
1762 {
1763 	sense_reason_t ret;
1764 
1765 	if (cmd->execute_cmd) {
1766 		ret = cmd->execute_cmd(cmd);
1767 		if (ret) {
1768 			spin_lock_irq(&cmd->t_state_lock);
1769 			cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1770 			spin_unlock_irq(&cmd->t_state_lock);
1771 
1772 			transport_generic_request_failure(cmd, ret);
1773 		}
1774 	}
1775 }
1776 
1777 static int target_write_prot_action(struct se_cmd *cmd)
1778 {
1779 	u32 sectors;
1780 	/*
1781 	 * Perform WRITE_INSERT of PI using software emulation when backend
1782 	 * device has PI enabled, if the transport has not already generated
1783 	 * PI using hardware WRITE_INSERT offload.
1784 	 */
1785 	switch (cmd->prot_op) {
1786 	case TARGET_PROT_DOUT_INSERT:
1787 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1788 			sbc_dif_generate(cmd);
1789 		break;
1790 	case TARGET_PROT_DOUT_STRIP:
1791 		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1792 			break;
1793 
1794 		sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1795 		cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1796 					     sectors, 0, cmd->t_prot_sg, 0);
1797 		if (unlikely(cmd->pi_err)) {
1798 			spin_lock_irq(&cmd->t_state_lock);
1799 			cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1800 			spin_unlock_irq(&cmd->t_state_lock);
1801 			transport_generic_request_failure(cmd, cmd->pi_err);
1802 			return -1;
1803 		}
1804 		break;
1805 	default:
1806 		break;
1807 	}
1808 
1809 	return 0;
1810 }
1811 
1812 static bool target_handle_task_attr(struct se_cmd *cmd)
1813 {
1814 	struct se_device *dev = cmd->se_dev;
1815 
1816 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1817 		return false;
1818 
1819 	/*
1820 	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1821 	 * to allow the passed struct se_cmd list of tasks to the front of the list.
1822 	 */
1823 	switch (cmd->sam_task_attr) {
1824 	case TCM_HEAD_TAG:
1825 		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
1826 			 cmd->t_task_cdb[0]);
1827 		return false;
1828 	case TCM_ORDERED_TAG:
1829 		atomic_inc_mb(&dev->dev_ordered_sync);
1830 
1831 		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
1832 			 cmd->t_task_cdb[0]);
1833 
1834 		/*
1835 		 * Execute an ORDERED command if no other older commands
1836 		 * exist that need to be completed first.
1837 		 */
1838 		if (!atomic_read(&dev->simple_cmds))
1839 			return false;
1840 		break;
1841 	default:
1842 		/*
1843 		 * For SIMPLE and UNTAGGED Task Attribute commands
1844 		 */
1845 		atomic_inc_mb(&dev->simple_cmds);
1846 		break;
1847 	}
1848 
1849 	if (atomic_read(&dev->dev_ordered_sync) == 0)
1850 		return false;
1851 
1852 	spin_lock(&dev->delayed_cmd_lock);
1853 	list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1854 	spin_unlock(&dev->delayed_cmd_lock);
1855 
1856 	pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
1857 		cmd->t_task_cdb[0], cmd->sam_task_attr);
1858 	return true;
1859 }
1860 
1861 void target_execute_cmd(struct se_cmd *cmd)
1862 {
1863 	/*
1864 	 * If the received CDB has aleady been aborted stop processing it here.
1865 	 */
1866 	if (transport_check_aborted_status(cmd, 1))
1867 		return;
1868 
1869 	/*
1870 	 * Determine if frontend context caller is requesting the stopping of
1871 	 * this command for frontend exceptions.
1872 	 */
1873 	spin_lock_irq(&cmd->t_state_lock);
1874 	if (cmd->transport_state & CMD_T_STOP) {
1875 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
1876 			__func__, __LINE__, cmd->tag);
1877 
1878 		spin_unlock_irq(&cmd->t_state_lock);
1879 		complete_all(&cmd->t_transport_stop_comp);
1880 		return;
1881 	}
1882 
1883 	cmd->t_state = TRANSPORT_PROCESSING;
1884 	cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1885 	spin_unlock_irq(&cmd->t_state_lock);
1886 
1887 	if (target_write_prot_action(cmd))
1888 		return;
1889 
1890 	if (target_handle_task_attr(cmd)) {
1891 		spin_lock_irq(&cmd->t_state_lock);
1892 		cmd->transport_state &= ~(CMD_T_BUSY | CMD_T_SENT);
1893 		spin_unlock_irq(&cmd->t_state_lock);
1894 		return;
1895 	}
1896 
1897 	__target_execute_cmd(cmd);
1898 }
1899 EXPORT_SYMBOL(target_execute_cmd);
1900 
1901 /*
1902  * Process all commands up to the last received ORDERED task attribute which
1903  * requires another blocking boundary
1904  */
1905 static void target_restart_delayed_cmds(struct se_device *dev)
1906 {
1907 	for (;;) {
1908 		struct se_cmd *cmd;
1909 
1910 		spin_lock(&dev->delayed_cmd_lock);
1911 		if (list_empty(&dev->delayed_cmd_list)) {
1912 			spin_unlock(&dev->delayed_cmd_lock);
1913 			break;
1914 		}
1915 
1916 		cmd = list_entry(dev->delayed_cmd_list.next,
1917 				 struct se_cmd, se_delayed_node);
1918 		list_del(&cmd->se_delayed_node);
1919 		spin_unlock(&dev->delayed_cmd_lock);
1920 
1921 		__target_execute_cmd(cmd);
1922 
1923 		if (cmd->sam_task_attr == TCM_ORDERED_TAG)
1924 			break;
1925 	}
1926 }
1927 
1928 /*
1929  * Called from I/O completion to determine which dormant/delayed
1930  * and ordered cmds need to have their tasks added to the execution queue.
1931  */
1932 static void transport_complete_task_attr(struct se_cmd *cmd)
1933 {
1934 	struct se_device *dev = cmd->se_dev;
1935 
1936 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1937 		return;
1938 
1939 	if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
1940 		atomic_dec_mb(&dev->simple_cmds);
1941 		dev->dev_cur_ordered_id++;
1942 		pr_debug("Incremented dev->dev_cur_ordered_id: %u for SIMPLE\n",
1943 			 dev->dev_cur_ordered_id);
1944 	} else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
1945 		dev->dev_cur_ordered_id++;
1946 		pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
1947 			 dev->dev_cur_ordered_id);
1948 	} else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
1949 		atomic_dec_mb(&dev->dev_ordered_sync);
1950 
1951 		dev->dev_cur_ordered_id++;
1952 		pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
1953 			 dev->dev_cur_ordered_id);
1954 	}
1955 
1956 	target_restart_delayed_cmds(dev);
1957 }
1958 
1959 static void transport_complete_qf(struct se_cmd *cmd)
1960 {
1961 	int ret = 0;
1962 
1963 	transport_complete_task_attr(cmd);
1964 
1965 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1966 		trace_target_cmd_complete(cmd);
1967 		ret = cmd->se_tfo->queue_status(cmd);
1968 		goto out;
1969 	}
1970 
1971 	switch (cmd->data_direction) {
1972 	case DMA_FROM_DEVICE:
1973 		trace_target_cmd_complete(cmd);
1974 		ret = cmd->se_tfo->queue_data_in(cmd);
1975 		break;
1976 	case DMA_TO_DEVICE:
1977 		if (cmd->se_cmd_flags & SCF_BIDI) {
1978 			ret = cmd->se_tfo->queue_data_in(cmd);
1979 			break;
1980 		}
1981 		/* Fall through for DMA_TO_DEVICE */
1982 	case DMA_NONE:
1983 		trace_target_cmd_complete(cmd);
1984 		ret = cmd->se_tfo->queue_status(cmd);
1985 		break;
1986 	default:
1987 		break;
1988 	}
1989 
1990 out:
1991 	if (ret < 0) {
1992 		transport_handle_queue_full(cmd, cmd->se_dev);
1993 		return;
1994 	}
1995 	transport_lun_remove_cmd(cmd);
1996 	transport_cmd_check_stop_to_fabric(cmd);
1997 }
1998 
1999 static void transport_handle_queue_full(
2000 	struct se_cmd *cmd,
2001 	struct se_device *dev)
2002 {
2003 	spin_lock_irq(&dev->qf_cmd_lock);
2004 	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2005 	atomic_inc_mb(&dev->dev_qf_count);
2006 	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2007 
2008 	schedule_work(&cmd->se_dev->qf_work_queue);
2009 }
2010 
2011 static bool target_read_prot_action(struct se_cmd *cmd)
2012 {
2013 	switch (cmd->prot_op) {
2014 	case TARGET_PROT_DIN_STRIP:
2015 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2016 			u32 sectors = cmd->data_length >>
2017 				  ilog2(cmd->se_dev->dev_attrib.block_size);
2018 
2019 			cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2020 						     sectors, 0, cmd->t_prot_sg,
2021 						     0);
2022 			if (cmd->pi_err)
2023 				return true;
2024 		}
2025 		break;
2026 	case TARGET_PROT_DIN_INSERT:
2027 		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2028 			break;
2029 
2030 		sbc_dif_generate(cmd);
2031 		break;
2032 	default:
2033 		break;
2034 	}
2035 
2036 	return false;
2037 }
2038 
2039 static void target_complete_ok_work(struct work_struct *work)
2040 {
2041 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2042 	int ret;
2043 
2044 	/*
2045 	 * Check if we need to move delayed/dormant tasks from cmds on the
2046 	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2047 	 * Attribute.
2048 	 */
2049 	transport_complete_task_attr(cmd);
2050 
2051 	/*
2052 	 * Check to schedule QUEUE_FULL work, or execute an existing
2053 	 * cmd->transport_qf_callback()
2054 	 */
2055 	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2056 		schedule_work(&cmd->se_dev->qf_work_queue);
2057 
2058 	/*
2059 	 * Check if we need to send a sense buffer from
2060 	 * the struct se_cmd in question.
2061 	 */
2062 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2063 		WARN_ON(!cmd->scsi_status);
2064 		ret = transport_send_check_condition_and_sense(
2065 					cmd, 0, 1);
2066 		if (ret == -EAGAIN || ret == -ENOMEM)
2067 			goto queue_full;
2068 
2069 		transport_lun_remove_cmd(cmd);
2070 		transport_cmd_check_stop_to_fabric(cmd);
2071 		return;
2072 	}
2073 	/*
2074 	 * Check for a callback, used by amongst other things
2075 	 * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2076 	 */
2077 	if (cmd->transport_complete_callback) {
2078 		sense_reason_t rc;
2079 		bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2080 		bool zero_dl = !(cmd->data_length);
2081 		int post_ret = 0;
2082 
2083 		rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2084 		if (!rc && !post_ret) {
2085 			if (caw && zero_dl)
2086 				goto queue_rsp;
2087 
2088 			return;
2089 		} else if (rc) {
2090 			ret = transport_send_check_condition_and_sense(cmd,
2091 						rc, 0);
2092 			if (ret == -EAGAIN || ret == -ENOMEM)
2093 				goto queue_full;
2094 
2095 			transport_lun_remove_cmd(cmd);
2096 			transport_cmd_check_stop_to_fabric(cmd);
2097 			return;
2098 		}
2099 	}
2100 
2101 queue_rsp:
2102 	switch (cmd->data_direction) {
2103 	case DMA_FROM_DEVICE:
2104 		atomic_long_add(cmd->data_length,
2105 				&cmd->se_lun->lun_stats.tx_data_octets);
2106 		/*
2107 		 * Perform READ_STRIP of PI using software emulation when
2108 		 * backend had PI enabled, if the transport will not be
2109 		 * performing hardware READ_STRIP offload.
2110 		 */
2111 		if (target_read_prot_action(cmd)) {
2112 			ret = transport_send_check_condition_and_sense(cmd,
2113 						cmd->pi_err, 0);
2114 			if (ret == -EAGAIN || ret == -ENOMEM)
2115 				goto queue_full;
2116 
2117 			transport_lun_remove_cmd(cmd);
2118 			transport_cmd_check_stop_to_fabric(cmd);
2119 			return;
2120 		}
2121 
2122 		trace_target_cmd_complete(cmd);
2123 		ret = cmd->se_tfo->queue_data_in(cmd);
2124 		if (ret == -EAGAIN || ret == -ENOMEM)
2125 			goto queue_full;
2126 		break;
2127 	case DMA_TO_DEVICE:
2128 		atomic_long_add(cmd->data_length,
2129 				&cmd->se_lun->lun_stats.rx_data_octets);
2130 		/*
2131 		 * Check if we need to send READ payload for BIDI-COMMAND
2132 		 */
2133 		if (cmd->se_cmd_flags & SCF_BIDI) {
2134 			atomic_long_add(cmd->data_length,
2135 					&cmd->se_lun->lun_stats.tx_data_octets);
2136 			ret = cmd->se_tfo->queue_data_in(cmd);
2137 			if (ret == -EAGAIN || ret == -ENOMEM)
2138 				goto queue_full;
2139 			break;
2140 		}
2141 		/* Fall through for DMA_TO_DEVICE */
2142 	case DMA_NONE:
2143 		trace_target_cmd_complete(cmd);
2144 		ret = cmd->se_tfo->queue_status(cmd);
2145 		if (ret == -EAGAIN || ret == -ENOMEM)
2146 			goto queue_full;
2147 		break;
2148 	default:
2149 		break;
2150 	}
2151 
2152 	transport_lun_remove_cmd(cmd);
2153 	transport_cmd_check_stop_to_fabric(cmd);
2154 	return;
2155 
2156 queue_full:
2157 	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2158 		" data_direction: %d\n", cmd, cmd->data_direction);
2159 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2160 	transport_handle_queue_full(cmd, cmd->se_dev);
2161 }
2162 
2163 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
2164 {
2165 	struct scatterlist *sg;
2166 	int count;
2167 
2168 	for_each_sg(sgl, sg, nents, count)
2169 		__free_page(sg_page(sg));
2170 
2171 	kfree(sgl);
2172 }
2173 
2174 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2175 {
2176 	/*
2177 	 * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2178 	 * emulation, and free + reset pointers if necessary..
2179 	 */
2180 	if (!cmd->t_data_sg_orig)
2181 		return;
2182 
2183 	kfree(cmd->t_data_sg);
2184 	cmd->t_data_sg = cmd->t_data_sg_orig;
2185 	cmd->t_data_sg_orig = NULL;
2186 	cmd->t_data_nents = cmd->t_data_nents_orig;
2187 	cmd->t_data_nents_orig = 0;
2188 }
2189 
2190 static inline void transport_free_pages(struct se_cmd *cmd)
2191 {
2192 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2193 		transport_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2194 		cmd->t_prot_sg = NULL;
2195 		cmd->t_prot_nents = 0;
2196 	}
2197 
2198 	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2199 		/*
2200 		 * Release special case READ buffer payload required for
2201 		 * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2202 		 */
2203 		if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2204 			transport_free_sgl(cmd->t_bidi_data_sg,
2205 					   cmd->t_bidi_data_nents);
2206 			cmd->t_bidi_data_sg = NULL;
2207 			cmd->t_bidi_data_nents = 0;
2208 		}
2209 		transport_reset_sgl_orig(cmd);
2210 		return;
2211 	}
2212 	transport_reset_sgl_orig(cmd);
2213 
2214 	transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2215 	cmd->t_data_sg = NULL;
2216 	cmd->t_data_nents = 0;
2217 
2218 	transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2219 	cmd->t_bidi_data_sg = NULL;
2220 	cmd->t_bidi_data_nents = 0;
2221 }
2222 
2223 /**
2224  * transport_put_cmd - release a reference to a command
2225  * @cmd:       command to release
2226  *
2227  * This routine releases our reference to the command and frees it if possible.
2228  */
2229 static int transport_put_cmd(struct se_cmd *cmd)
2230 {
2231 	BUG_ON(!cmd->se_tfo);
2232 	/*
2233 	 * If this cmd has been setup with target_get_sess_cmd(), drop
2234 	 * the kref and call ->release_cmd() in kref callback.
2235 	 */
2236 	return target_put_sess_cmd(cmd);
2237 }
2238 
2239 void *transport_kmap_data_sg(struct se_cmd *cmd)
2240 {
2241 	struct scatterlist *sg = cmd->t_data_sg;
2242 	struct page **pages;
2243 	int i;
2244 
2245 	/*
2246 	 * We need to take into account a possible offset here for fabrics like
2247 	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2248 	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2249 	 */
2250 	if (!cmd->t_data_nents)
2251 		return NULL;
2252 
2253 	BUG_ON(!sg);
2254 	if (cmd->t_data_nents == 1)
2255 		return kmap(sg_page(sg)) + sg->offset;
2256 
2257 	/* >1 page. use vmap */
2258 	pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2259 	if (!pages)
2260 		return NULL;
2261 
2262 	/* convert sg[] to pages[] */
2263 	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2264 		pages[i] = sg_page(sg);
2265 	}
2266 
2267 	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2268 	kfree(pages);
2269 	if (!cmd->t_data_vmap)
2270 		return NULL;
2271 
2272 	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2273 }
2274 EXPORT_SYMBOL(transport_kmap_data_sg);
2275 
2276 void transport_kunmap_data_sg(struct se_cmd *cmd)
2277 {
2278 	if (!cmd->t_data_nents) {
2279 		return;
2280 	} else if (cmd->t_data_nents == 1) {
2281 		kunmap(sg_page(cmd->t_data_sg));
2282 		return;
2283 	}
2284 
2285 	vunmap(cmd->t_data_vmap);
2286 	cmd->t_data_vmap = NULL;
2287 }
2288 EXPORT_SYMBOL(transport_kunmap_data_sg);
2289 
2290 int
2291 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2292 		 bool zero_page)
2293 {
2294 	struct scatterlist *sg;
2295 	struct page *page;
2296 	gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2297 	unsigned int nent;
2298 	int i = 0;
2299 
2300 	nent = DIV_ROUND_UP(length, PAGE_SIZE);
2301 	sg = kmalloc(sizeof(struct scatterlist) * nent, GFP_KERNEL);
2302 	if (!sg)
2303 		return -ENOMEM;
2304 
2305 	sg_init_table(sg, nent);
2306 
2307 	while (length) {
2308 		u32 page_len = min_t(u32, length, PAGE_SIZE);
2309 		page = alloc_page(GFP_KERNEL | zero_flag);
2310 		if (!page)
2311 			goto out;
2312 
2313 		sg_set_page(&sg[i], page, page_len, 0);
2314 		length -= page_len;
2315 		i++;
2316 	}
2317 	*sgl = sg;
2318 	*nents = nent;
2319 	return 0;
2320 
2321 out:
2322 	while (i > 0) {
2323 		i--;
2324 		__free_page(sg_page(&sg[i]));
2325 	}
2326 	kfree(sg);
2327 	return -ENOMEM;
2328 }
2329 
2330 /*
2331  * Allocate any required resources to execute the command.  For writes we
2332  * might not have the payload yet, so notify the fabric via a call to
2333  * ->write_pending instead. Otherwise place it on the execution queue.
2334  */
2335 sense_reason_t
2336 transport_generic_new_cmd(struct se_cmd *cmd)
2337 {
2338 	int ret = 0;
2339 	bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2340 
2341 	if (cmd->prot_op != TARGET_PROT_NORMAL &&
2342 	    !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2343 		ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2344 				       cmd->prot_length, true);
2345 		if (ret < 0)
2346 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2347 	}
2348 
2349 	/*
2350 	 * Determine is the TCM fabric module has already allocated physical
2351 	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2352 	 * beforehand.
2353 	 */
2354 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2355 	    cmd->data_length) {
2356 
2357 		if ((cmd->se_cmd_flags & SCF_BIDI) ||
2358 		    (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2359 			u32 bidi_length;
2360 
2361 			if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2362 				bidi_length = cmd->t_task_nolb *
2363 					      cmd->se_dev->dev_attrib.block_size;
2364 			else
2365 				bidi_length = cmd->data_length;
2366 
2367 			ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2368 					       &cmd->t_bidi_data_nents,
2369 					       bidi_length, zero_flag);
2370 			if (ret < 0)
2371 				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2372 		}
2373 
2374 		ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2375 				       cmd->data_length, zero_flag);
2376 		if (ret < 0)
2377 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2378 	} else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2379 		    cmd->data_length) {
2380 		/*
2381 		 * Special case for COMPARE_AND_WRITE with fabrics
2382 		 * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2383 		 */
2384 		u32 caw_length = cmd->t_task_nolb *
2385 				 cmd->se_dev->dev_attrib.block_size;
2386 
2387 		ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2388 				       &cmd->t_bidi_data_nents,
2389 				       caw_length, zero_flag);
2390 		if (ret < 0)
2391 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2392 	}
2393 	/*
2394 	 * If this command is not a write we can execute it right here,
2395 	 * for write buffers we need to notify the fabric driver first
2396 	 * and let it call back once the write buffers are ready.
2397 	 */
2398 	target_add_to_state_list(cmd);
2399 	if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2400 		target_execute_cmd(cmd);
2401 		return 0;
2402 	}
2403 	transport_cmd_check_stop(cmd, false, true);
2404 
2405 	ret = cmd->se_tfo->write_pending(cmd);
2406 	if (ret == -EAGAIN || ret == -ENOMEM)
2407 		goto queue_full;
2408 
2409 	/* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2410 	WARN_ON(ret);
2411 
2412 	return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2413 
2414 queue_full:
2415 	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2416 	cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2417 	transport_handle_queue_full(cmd, cmd->se_dev);
2418 	return 0;
2419 }
2420 EXPORT_SYMBOL(transport_generic_new_cmd);
2421 
2422 static void transport_write_pending_qf(struct se_cmd *cmd)
2423 {
2424 	int ret;
2425 
2426 	ret = cmd->se_tfo->write_pending(cmd);
2427 	if (ret == -EAGAIN || ret == -ENOMEM) {
2428 		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2429 			 cmd);
2430 		transport_handle_queue_full(cmd, cmd->se_dev);
2431 	}
2432 }
2433 
2434 static bool
2435 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2436 			   unsigned long *flags);
2437 
2438 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2439 {
2440 	unsigned long flags;
2441 
2442 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2443 	__transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2444 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2445 }
2446 
2447 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2448 {
2449 	int ret = 0;
2450 	bool aborted = false, tas = false;
2451 
2452 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2453 		if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2454 			target_wait_free_cmd(cmd, &aborted, &tas);
2455 
2456 		if (!aborted || tas)
2457 			ret = transport_put_cmd(cmd);
2458 	} else {
2459 		if (wait_for_tasks)
2460 			target_wait_free_cmd(cmd, &aborted, &tas);
2461 		/*
2462 		 * Handle WRITE failure case where transport_generic_new_cmd()
2463 		 * has already added se_cmd to state_list, but fabric has
2464 		 * failed command before I/O submission.
2465 		 */
2466 		if (cmd->state_active)
2467 			target_remove_from_state_list(cmd);
2468 
2469 		if (cmd->se_lun)
2470 			transport_lun_remove_cmd(cmd);
2471 
2472 		if (!aborted || tas)
2473 			ret = transport_put_cmd(cmd);
2474 	}
2475 	/*
2476 	 * If the task has been internally aborted due to TMR ABORT_TASK
2477 	 * or LUN_RESET, target_core_tmr.c is responsible for performing
2478 	 * the remaining calls to target_put_sess_cmd(), and not the
2479 	 * callers of this function.
2480 	 */
2481 	if (aborted) {
2482 		pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2483 		wait_for_completion(&cmd->cmd_wait_comp);
2484 		cmd->se_tfo->release_cmd(cmd);
2485 		ret = 1;
2486 	}
2487 	return ret;
2488 }
2489 EXPORT_SYMBOL(transport_generic_free_cmd);
2490 
2491 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2492  * @se_cmd:	command descriptor to add
2493  * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
2494  */
2495 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2496 {
2497 	struct se_session *se_sess = se_cmd->se_sess;
2498 	unsigned long flags;
2499 	int ret = 0;
2500 
2501 	/*
2502 	 * Add a second kref if the fabric caller is expecting to handle
2503 	 * fabric acknowledgement that requires two target_put_sess_cmd()
2504 	 * invocations before se_cmd descriptor release.
2505 	 */
2506 	if (ack_kref)
2507 		kref_get(&se_cmd->cmd_kref);
2508 
2509 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2510 	if (se_sess->sess_tearing_down) {
2511 		ret = -ESHUTDOWN;
2512 		goto out;
2513 	}
2514 	list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2515 out:
2516 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2517 
2518 	if (ret && ack_kref)
2519 		target_put_sess_cmd(se_cmd);
2520 
2521 	return ret;
2522 }
2523 EXPORT_SYMBOL(target_get_sess_cmd);
2524 
2525 static void target_free_cmd_mem(struct se_cmd *cmd)
2526 {
2527 	transport_free_pages(cmd);
2528 
2529 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2530 		core_tmr_release_req(cmd->se_tmr_req);
2531 	if (cmd->t_task_cdb != cmd->__t_task_cdb)
2532 		kfree(cmd->t_task_cdb);
2533 }
2534 
2535 static void target_release_cmd_kref(struct kref *kref)
2536 {
2537 	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2538 	struct se_session *se_sess = se_cmd->se_sess;
2539 	unsigned long flags;
2540 	bool fabric_stop;
2541 
2542 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2543 	if (list_empty(&se_cmd->se_cmd_list)) {
2544 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2545 		target_free_cmd_mem(se_cmd);
2546 		se_cmd->se_tfo->release_cmd(se_cmd);
2547 		return;
2548 	}
2549 
2550 	spin_lock(&se_cmd->t_state_lock);
2551 	fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP);
2552 	spin_unlock(&se_cmd->t_state_lock);
2553 
2554 	if (se_cmd->cmd_wait_set || fabric_stop) {
2555 		list_del_init(&se_cmd->se_cmd_list);
2556 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2557 		target_free_cmd_mem(se_cmd);
2558 		complete(&se_cmd->cmd_wait_comp);
2559 		return;
2560 	}
2561 	list_del_init(&se_cmd->se_cmd_list);
2562 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2563 
2564 	target_free_cmd_mem(se_cmd);
2565 	se_cmd->se_tfo->release_cmd(se_cmd);
2566 }
2567 
2568 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2569  * @se_cmd:	command descriptor to drop
2570  */
2571 int target_put_sess_cmd(struct se_cmd *se_cmd)
2572 {
2573 	struct se_session *se_sess = se_cmd->se_sess;
2574 
2575 	if (!se_sess) {
2576 		target_free_cmd_mem(se_cmd);
2577 		se_cmd->se_tfo->release_cmd(se_cmd);
2578 		return 1;
2579 	}
2580 	return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2581 }
2582 EXPORT_SYMBOL(target_put_sess_cmd);
2583 
2584 /* target_sess_cmd_list_set_waiting - Flag all commands in
2585  *         sess_cmd_list to complete cmd_wait_comp.  Set
2586  *         sess_tearing_down so no more commands are queued.
2587  * @se_sess:	session to flag
2588  */
2589 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2590 {
2591 	struct se_cmd *se_cmd;
2592 	unsigned long flags;
2593 	int rc;
2594 
2595 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2596 	if (se_sess->sess_tearing_down) {
2597 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2598 		return;
2599 	}
2600 	se_sess->sess_tearing_down = 1;
2601 	list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2602 
2603 	list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list) {
2604 		rc = kref_get_unless_zero(&se_cmd->cmd_kref);
2605 		if (rc) {
2606 			se_cmd->cmd_wait_set = 1;
2607 			spin_lock(&se_cmd->t_state_lock);
2608 			se_cmd->transport_state |= CMD_T_FABRIC_STOP;
2609 			spin_unlock(&se_cmd->t_state_lock);
2610 		}
2611 	}
2612 
2613 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2614 }
2615 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2616 
2617 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2618  * @se_sess:    session to wait for active I/O
2619  */
2620 void target_wait_for_sess_cmds(struct se_session *se_sess)
2621 {
2622 	struct se_cmd *se_cmd, *tmp_cmd;
2623 	unsigned long flags;
2624 	bool tas;
2625 
2626 	list_for_each_entry_safe(se_cmd, tmp_cmd,
2627 				&se_sess->sess_wait_list, se_cmd_list) {
2628 		list_del_init(&se_cmd->se_cmd_list);
2629 
2630 		pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2631 			" %d\n", se_cmd, se_cmd->t_state,
2632 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2633 
2634 		spin_lock_irqsave(&se_cmd->t_state_lock, flags);
2635 		tas = (se_cmd->transport_state & CMD_T_TAS);
2636 		spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
2637 
2638 		if (!target_put_sess_cmd(se_cmd)) {
2639 			if (tas)
2640 				target_put_sess_cmd(se_cmd);
2641 		}
2642 
2643 		wait_for_completion(&se_cmd->cmd_wait_comp);
2644 		pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2645 			" fabric state: %d\n", se_cmd, se_cmd->t_state,
2646 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2647 
2648 		se_cmd->se_tfo->release_cmd(se_cmd);
2649 	}
2650 
2651 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2652 	WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2653 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2654 
2655 }
2656 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2657 
2658 void transport_clear_lun_ref(struct se_lun *lun)
2659 {
2660 	percpu_ref_kill(&lun->lun_ref);
2661 	wait_for_completion(&lun->lun_ref_comp);
2662 }
2663 
2664 static bool
2665 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2666 			   bool *aborted, bool *tas, unsigned long *flags)
2667 	__releases(&cmd->t_state_lock)
2668 	__acquires(&cmd->t_state_lock)
2669 {
2670 
2671 	assert_spin_locked(&cmd->t_state_lock);
2672 	WARN_ON_ONCE(!irqs_disabled());
2673 
2674 	if (fabric_stop)
2675 		cmd->transport_state |= CMD_T_FABRIC_STOP;
2676 
2677 	if (cmd->transport_state & CMD_T_ABORTED)
2678 		*aborted = true;
2679 
2680 	if (cmd->transport_state & CMD_T_TAS)
2681 		*tas = true;
2682 
2683 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2684 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2685 		return false;
2686 
2687 	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2688 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2689 		return false;
2690 
2691 	if (!(cmd->transport_state & CMD_T_ACTIVE))
2692 		return false;
2693 
2694 	if (fabric_stop && *aborted)
2695 		return false;
2696 
2697 	cmd->transport_state |= CMD_T_STOP;
2698 
2699 	pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08llx i_state: %d,"
2700 		 " t_state: %d, CMD_T_STOP\n", cmd, cmd->tag,
2701 		 cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2702 
2703 	spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
2704 
2705 	wait_for_completion(&cmd->t_transport_stop_comp);
2706 
2707 	spin_lock_irqsave(&cmd->t_state_lock, *flags);
2708 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2709 
2710 	pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
2711 		 "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
2712 
2713 	return true;
2714 }
2715 
2716 /**
2717  * transport_wait_for_tasks - wait for completion to occur
2718  * @cmd:	command to wait
2719  *
2720  * Called from frontend fabric context to wait for storage engine
2721  * to pause and/or release frontend generated struct se_cmd.
2722  */
2723 bool transport_wait_for_tasks(struct se_cmd *cmd)
2724 {
2725 	unsigned long flags;
2726 	bool ret, aborted = false, tas = false;
2727 
2728 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2729 	ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
2730 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2731 
2732 	return ret;
2733 }
2734 EXPORT_SYMBOL(transport_wait_for_tasks);
2735 
2736 struct sense_info {
2737 	u8 key;
2738 	u8 asc;
2739 	u8 ascq;
2740 	bool add_sector_info;
2741 };
2742 
2743 static const struct sense_info sense_info_table[] = {
2744 	[TCM_NO_SENSE] = {
2745 		.key = NOT_READY
2746 	},
2747 	[TCM_NON_EXISTENT_LUN] = {
2748 		.key = ILLEGAL_REQUEST,
2749 		.asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
2750 	},
2751 	[TCM_UNSUPPORTED_SCSI_OPCODE] = {
2752 		.key = ILLEGAL_REQUEST,
2753 		.asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2754 	},
2755 	[TCM_SECTOR_COUNT_TOO_MANY] = {
2756 		.key = ILLEGAL_REQUEST,
2757 		.asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2758 	},
2759 	[TCM_UNKNOWN_MODE_PAGE] = {
2760 		.key = ILLEGAL_REQUEST,
2761 		.asc = 0x24, /* INVALID FIELD IN CDB */
2762 	},
2763 	[TCM_CHECK_CONDITION_ABORT_CMD] = {
2764 		.key = ABORTED_COMMAND,
2765 		.asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
2766 		.ascq = 0x03,
2767 	},
2768 	[TCM_INCORRECT_AMOUNT_OF_DATA] = {
2769 		.key = ABORTED_COMMAND,
2770 		.asc = 0x0c, /* WRITE ERROR */
2771 		.ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
2772 	},
2773 	[TCM_INVALID_CDB_FIELD] = {
2774 		.key = ILLEGAL_REQUEST,
2775 		.asc = 0x24, /* INVALID FIELD IN CDB */
2776 	},
2777 	[TCM_INVALID_PARAMETER_LIST] = {
2778 		.key = ILLEGAL_REQUEST,
2779 		.asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
2780 	},
2781 	[TCM_PARAMETER_LIST_LENGTH_ERROR] = {
2782 		.key = ILLEGAL_REQUEST,
2783 		.asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
2784 	},
2785 	[TCM_UNEXPECTED_UNSOLICITED_DATA] = {
2786 		.key = ILLEGAL_REQUEST,
2787 		.asc = 0x0c, /* WRITE ERROR */
2788 		.ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
2789 	},
2790 	[TCM_SERVICE_CRC_ERROR] = {
2791 		.key = ABORTED_COMMAND,
2792 		.asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
2793 		.ascq = 0x05, /* N/A */
2794 	},
2795 	[TCM_SNACK_REJECTED] = {
2796 		.key = ABORTED_COMMAND,
2797 		.asc = 0x11, /* READ ERROR */
2798 		.ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
2799 	},
2800 	[TCM_WRITE_PROTECTED] = {
2801 		.key = DATA_PROTECT,
2802 		.asc = 0x27, /* WRITE PROTECTED */
2803 	},
2804 	[TCM_ADDRESS_OUT_OF_RANGE] = {
2805 		.key = ILLEGAL_REQUEST,
2806 		.asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2807 	},
2808 	[TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
2809 		.key = UNIT_ATTENTION,
2810 	},
2811 	[TCM_CHECK_CONDITION_NOT_READY] = {
2812 		.key = NOT_READY,
2813 	},
2814 	[TCM_MISCOMPARE_VERIFY] = {
2815 		.key = MISCOMPARE,
2816 		.asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
2817 		.ascq = 0x00,
2818 	},
2819 	[TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
2820 		.key = ABORTED_COMMAND,
2821 		.asc = 0x10,
2822 		.ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
2823 		.add_sector_info = true,
2824 	},
2825 	[TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
2826 		.key = ABORTED_COMMAND,
2827 		.asc = 0x10,
2828 		.ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2829 		.add_sector_info = true,
2830 	},
2831 	[TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
2832 		.key = ABORTED_COMMAND,
2833 		.asc = 0x10,
2834 		.ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2835 		.add_sector_info = true,
2836 	},
2837 	[TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
2838 		/*
2839 		 * Returning ILLEGAL REQUEST would cause immediate IO errors on
2840 		 * Solaris initiators.  Returning NOT READY instead means the
2841 		 * operations will be retried a finite number of times and we
2842 		 * can survive intermittent errors.
2843 		 */
2844 		.key = NOT_READY,
2845 		.asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
2846 	},
2847 };
2848 
2849 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
2850 {
2851 	const struct sense_info *si;
2852 	u8 *buffer = cmd->sense_buffer;
2853 	int r = (__force int)reason;
2854 	u8 asc, ascq;
2855 	bool desc_format = target_sense_desc_format(cmd->se_dev);
2856 
2857 	if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
2858 		si = &sense_info_table[r];
2859 	else
2860 		si = &sense_info_table[(__force int)
2861 				       TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
2862 
2863 	if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
2864 		core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2865 		WARN_ON_ONCE(asc == 0);
2866 	} else if (si->asc == 0) {
2867 		WARN_ON_ONCE(cmd->scsi_asc == 0);
2868 		asc = cmd->scsi_asc;
2869 		ascq = cmd->scsi_ascq;
2870 	} else {
2871 		asc = si->asc;
2872 		ascq = si->ascq;
2873 	}
2874 
2875 	scsi_build_sense_buffer(desc_format, buffer, si->key, asc, ascq);
2876 	if (si->add_sector_info)
2877 		return scsi_set_sense_information(buffer,
2878 						  cmd->scsi_sense_length,
2879 						  cmd->bad_sector);
2880 
2881 	return 0;
2882 }
2883 
2884 int
2885 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2886 		sense_reason_t reason, int from_transport)
2887 {
2888 	unsigned long flags;
2889 
2890 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2891 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2892 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2893 		return 0;
2894 	}
2895 	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2896 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2897 
2898 	if (!from_transport) {
2899 		int rc;
2900 
2901 		cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2902 		cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2903 		cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2904 		rc = translate_sense_reason(cmd, reason);
2905 		if (rc)
2906 			return rc;
2907 	}
2908 
2909 	trace_target_cmd_complete(cmd);
2910 	return cmd->se_tfo->queue_status(cmd);
2911 }
2912 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2913 
2914 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2915 {
2916 	if (!(cmd->transport_state & CMD_T_ABORTED))
2917 		return 0;
2918 
2919 	/*
2920 	 * If cmd has been aborted but either no status is to be sent or it has
2921 	 * already been sent, just return
2922 	 */
2923 	if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS))
2924 		return 1;
2925 
2926 	pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08llx\n",
2927 		 cmd->t_task_cdb[0], cmd->tag);
2928 
2929 	cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
2930 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2931 	trace_target_cmd_complete(cmd);
2932 	cmd->se_tfo->queue_status(cmd);
2933 
2934 	return 1;
2935 }
2936 EXPORT_SYMBOL(transport_check_aborted_status);
2937 
2938 void transport_send_task_abort(struct se_cmd *cmd)
2939 {
2940 	unsigned long flags;
2941 
2942 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2943 	if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
2944 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2945 		return;
2946 	}
2947 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2948 
2949 	/*
2950 	 * If there are still expected incoming fabric WRITEs, we wait
2951 	 * until until they have completed before sending a TASK_ABORTED
2952 	 * response.  This response with TASK_ABORTED status will be
2953 	 * queued back to fabric module by transport_check_aborted_status().
2954 	 */
2955 	if (cmd->data_direction == DMA_TO_DEVICE) {
2956 		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
2957 			cmd->transport_state |= CMD_T_ABORTED;
2958 			cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
2959 			return;
2960 		}
2961 	}
2962 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2963 
2964 	transport_lun_remove_cmd(cmd);
2965 
2966 	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
2967 		 cmd->t_task_cdb[0], cmd->tag);
2968 
2969 	trace_target_cmd_complete(cmd);
2970 	cmd->se_tfo->queue_status(cmd);
2971 }
2972 
2973 static void target_tmr_work(struct work_struct *work)
2974 {
2975 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2976 	struct se_device *dev = cmd->se_dev;
2977 	struct se_tmr_req *tmr = cmd->se_tmr_req;
2978 	unsigned long flags;
2979 	int ret;
2980 
2981 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2982 	if (cmd->transport_state & CMD_T_ABORTED) {
2983 		tmr->response = TMR_FUNCTION_REJECTED;
2984 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2985 		goto check_stop;
2986 	}
2987 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2988 
2989 	switch (tmr->function) {
2990 	case TMR_ABORT_TASK:
2991 		core_tmr_abort_task(dev, tmr, cmd->se_sess);
2992 		break;
2993 	case TMR_ABORT_TASK_SET:
2994 	case TMR_CLEAR_ACA:
2995 	case TMR_CLEAR_TASK_SET:
2996 		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
2997 		break;
2998 	case TMR_LUN_RESET:
2999 		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3000 		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3001 					 TMR_FUNCTION_REJECTED;
3002 		if (tmr->response == TMR_FUNCTION_COMPLETE) {
3003 			target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3004 					       cmd->orig_fe_lun, 0x29,
3005 					       ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3006 		}
3007 		break;
3008 	case TMR_TARGET_WARM_RESET:
3009 		tmr->response = TMR_FUNCTION_REJECTED;
3010 		break;
3011 	case TMR_TARGET_COLD_RESET:
3012 		tmr->response = TMR_FUNCTION_REJECTED;
3013 		break;
3014 	default:
3015 		pr_err("Uknown TMR function: 0x%02x.\n",
3016 				tmr->function);
3017 		tmr->response = TMR_FUNCTION_REJECTED;
3018 		break;
3019 	}
3020 
3021 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3022 	if (cmd->transport_state & CMD_T_ABORTED) {
3023 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3024 		goto check_stop;
3025 	}
3026 	cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3027 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3028 
3029 	cmd->se_tfo->queue_tm_rsp(cmd);
3030 
3031 check_stop:
3032 	transport_cmd_check_stop_to_fabric(cmd);
3033 }
3034 
3035 int transport_generic_handle_tmr(
3036 	struct se_cmd *cmd)
3037 {
3038 	unsigned long flags;
3039 
3040 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3041 	cmd->transport_state |= CMD_T_ACTIVE;
3042 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3043 
3044 	INIT_WORK(&cmd->work, target_tmr_work);
3045 	queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3046 	return 0;
3047 }
3048 EXPORT_SYMBOL(transport_generic_handle_tmr);
3049 
3050 bool
3051 target_check_wce(struct se_device *dev)
3052 {
3053 	bool wce = false;
3054 
3055 	if (dev->transport->get_write_cache)
3056 		wce = dev->transport->get_write_cache(dev);
3057 	else if (dev->dev_attrib.emulate_write_cache > 0)
3058 		wce = true;
3059 
3060 	return wce;
3061 }
3062 
3063 bool
3064 target_check_fua(struct se_device *dev)
3065 {
3066 	return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3067 }
3068