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