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