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 <asm/unaligned.h>
38 #include <net/sock.h>
39 #include <net/tcp.h>
40 #include <scsi/scsi.h>
41 #include <scsi/scsi_cmnd.h>
42 #include <scsi/scsi_tcq.h>
43 
44 #include <target/target_core_base.h>
45 #include <target/target_core_backend.h>
46 #include <target/target_core_fabric.h>
47 #include <target/target_core_configfs.h>
48 
49 #include "target_core_internal.h"
50 #include "target_core_alua.h"
51 #include "target_core_pr.h"
52 #include "target_core_ua.h"
53 
54 #define CREATE_TRACE_POINTS
55 #include <trace/events/target.h>
56 
57 static struct workqueue_struct *target_completion_wq;
58 static struct kmem_cache *se_sess_cache;
59 struct kmem_cache *se_ua_cache;
60 struct kmem_cache *t10_pr_reg_cache;
61 struct kmem_cache *t10_alua_lu_gp_cache;
62 struct kmem_cache *t10_alua_lu_gp_mem_cache;
63 struct kmem_cache *t10_alua_tg_pt_gp_cache;
64 struct kmem_cache *t10_alua_tg_pt_gp_mem_cache;
65 struct kmem_cache *t10_alua_lba_map_cache;
66 struct kmem_cache *t10_alua_lba_map_mem_cache;
67 
68 static void transport_complete_task_attr(struct se_cmd *cmd);
69 static void transport_handle_queue_full(struct se_cmd *cmd,
70 		struct se_device *dev);
71 static int transport_put_cmd(struct se_cmd *cmd);
72 static void target_complete_ok_work(struct work_struct *work);
73 
74 int init_se_kmem_caches(void)
75 {
76 	se_sess_cache = kmem_cache_create("se_sess_cache",
77 			sizeof(struct se_session), __alignof__(struct se_session),
78 			0, NULL);
79 	if (!se_sess_cache) {
80 		pr_err("kmem_cache_create() for struct se_session"
81 				" failed\n");
82 		goto out;
83 	}
84 	se_ua_cache = kmem_cache_create("se_ua_cache",
85 			sizeof(struct se_ua), __alignof__(struct se_ua),
86 			0, NULL);
87 	if (!se_ua_cache) {
88 		pr_err("kmem_cache_create() for struct se_ua failed\n");
89 		goto out_free_sess_cache;
90 	}
91 	t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
92 			sizeof(struct t10_pr_registration),
93 			__alignof__(struct t10_pr_registration), 0, NULL);
94 	if (!t10_pr_reg_cache) {
95 		pr_err("kmem_cache_create() for struct t10_pr_registration"
96 				" failed\n");
97 		goto out_free_ua_cache;
98 	}
99 	t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
100 			sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
101 			0, NULL);
102 	if (!t10_alua_lu_gp_cache) {
103 		pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
104 				" failed\n");
105 		goto out_free_pr_reg_cache;
106 	}
107 	t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
108 			sizeof(struct t10_alua_lu_gp_member),
109 			__alignof__(struct t10_alua_lu_gp_member), 0, NULL);
110 	if (!t10_alua_lu_gp_mem_cache) {
111 		pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
112 				"cache failed\n");
113 		goto out_free_lu_gp_cache;
114 	}
115 	t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
116 			sizeof(struct t10_alua_tg_pt_gp),
117 			__alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
118 	if (!t10_alua_tg_pt_gp_cache) {
119 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
120 				"cache failed\n");
121 		goto out_free_lu_gp_mem_cache;
122 	}
123 	t10_alua_tg_pt_gp_mem_cache = kmem_cache_create(
124 			"t10_alua_tg_pt_gp_mem_cache",
125 			sizeof(struct t10_alua_tg_pt_gp_member),
126 			__alignof__(struct t10_alua_tg_pt_gp_member),
127 			0, NULL);
128 	if (!t10_alua_tg_pt_gp_mem_cache) {
129 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
130 				"mem_t failed\n");
131 		goto out_free_tg_pt_gp_cache;
132 	}
133 	t10_alua_lba_map_cache = kmem_cache_create(
134 			"t10_alua_lba_map_cache",
135 			sizeof(struct t10_alua_lba_map),
136 			__alignof__(struct t10_alua_lba_map), 0, NULL);
137 	if (!t10_alua_lba_map_cache) {
138 		pr_err("kmem_cache_create() for t10_alua_lba_map_"
139 				"cache failed\n");
140 		goto out_free_tg_pt_gp_mem_cache;
141 	}
142 	t10_alua_lba_map_mem_cache = kmem_cache_create(
143 			"t10_alua_lba_map_mem_cache",
144 			sizeof(struct t10_alua_lba_map_member),
145 			__alignof__(struct t10_alua_lba_map_member), 0, NULL);
146 	if (!t10_alua_lba_map_mem_cache) {
147 		pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
148 				"cache failed\n");
149 		goto out_free_lba_map_cache;
150 	}
151 
152 	target_completion_wq = alloc_workqueue("target_completion",
153 					       WQ_MEM_RECLAIM, 0);
154 	if (!target_completion_wq)
155 		goto out_free_lba_map_mem_cache;
156 
157 	return 0;
158 
159 out_free_lba_map_mem_cache:
160 	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
161 out_free_lba_map_cache:
162 	kmem_cache_destroy(t10_alua_lba_map_cache);
163 out_free_tg_pt_gp_mem_cache:
164 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
165 out_free_tg_pt_gp_cache:
166 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
167 out_free_lu_gp_mem_cache:
168 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
169 out_free_lu_gp_cache:
170 	kmem_cache_destroy(t10_alua_lu_gp_cache);
171 out_free_pr_reg_cache:
172 	kmem_cache_destroy(t10_pr_reg_cache);
173 out_free_ua_cache:
174 	kmem_cache_destroy(se_ua_cache);
175 out_free_sess_cache:
176 	kmem_cache_destroy(se_sess_cache);
177 out:
178 	return -ENOMEM;
179 }
180 
181 void release_se_kmem_caches(void)
182 {
183 	destroy_workqueue(target_completion_wq);
184 	kmem_cache_destroy(se_sess_cache);
185 	kmem_cache_destroy(se_ua_cache);
186 	kmem_cache_destroy(t10_pr_reg_cache);
187 	kmem_cache_destroy(t10_alua_lu_gp_cache);
188 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
189 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
190 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
191 	kmem_cache_destroy(t10_alua_lba_map_cache);
192 	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
193 }
194 
195 /* This code ensures unique mib indexes are handed out. */
196 static DEFINE_SPINLOCK(scsi_mib_index_lock);
197 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
198 
199 /*
200  * Allocate a new row index for the entry type specified
201  */
202 u32 scsi_get_new_index(scsi_index_t type)
203 {
204 	u32 new_index;
205 
206 	BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
207 
208 	spin_lock(&scsi_mib_index_lock);
209 	new_index = ++scsi_mib_index[type];
210 	spin_unlock(&scsi_mib_index_lock);
211 
212 	return new_index;
213 }
214 
215 void transport_subsystem_check_init(void)
216 {
217 	int ret;
218 	static int sub_api_initialized;
219 
220 	if (sub_api_initialized)
221 		return;
222 
223 	ret = request_module("target_core_iblock");
224 	if (ret != 0)
225 		pr_err("Unable to load target_core_iblock\n");
226 
227 	ret = request_module("target_core_file");
228 	if (ret != 0)
229 		pr_err("Unable to load target_core_file\n");
230 
231 	ret = request_module("target_core_pscsi");
232 	if (ret != 0)
233 		pr_err("Unable to load target_core_pscsi\n");
234 
235 	sub_api_initialized = 1;
236 }
237 
238 struct se_session *transport_init_session(enum target_prot_op sup_prot_ops)
239 {
240 	struct se_session *se_sess;
241 
242 	se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
243 	if (!se_sess) {
244 		pr_err("Unable to allocate struct se_session from"
245 				" se_sess_cache\n");
246 		return ERR_PTR(-ENOMEM);
247 	}
248 	INIT_LIST_HEAD(&se_sess->sess_list);
249 	INIT_LIST_HEAD(&se_sess->sess_acl_list);
250 	INIT_LIST_HEAD(&se_sess->sess_cmd_list);
251 	INIT_LIST_HEAD(&se_sess->sess_wait_list);
252 	spin_lock_init(&se_sess->sess_cmd_lock);
253 	kref_init(&se_sess->sess_kref);
254 	se_sess->sup_prot_ops = sup_prot_ops;
255 
256 	return se_sess;
257 }
258 EXPORT_SYMBOL(transport_init_session);
259 
260 int transport_alloc_session_tags(struct se_session *se_sess,
261 			         unsigned int tag_num, unsigned int tag_size)
262 {
263 	int rc;
264 
265 	se_sess->sess_cmd_map = kzalloc(tag_num * tag_size,
266 					GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
267 	if (!se_sess->sess_cmd_map) {
268 		se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
269 		if (!se_sess->sess_cmd_map) {
270 			pr_err("Unable to allocate se_sess->sess_cmd_map\n");
271 			return -ENOMEM;
272 		}
273 	}
274 
275 	rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
276 	if (rc < 0) {
277 		pr_err("Unable to init se_sess->sess_tag_pool,"
278 			" tag_num: %u\n", tag_num);
279 		if (is_vmalloc_addr(se_sess->sess_cmd_map))
280 			vfree(se_sess->sess_cmd_map);
281 		else
282 			kfree(se_sess->sess_cmd_map);
283 		se_sess->sess_cmd_map = NULL;
284 		return -ENOMEM;
285 	}
286 
287 	return 0;
288 }
289 EXPORT_SYMBOL(transport_alloc_session_tags);
290 
291 struct se_session *transport_init_session_tags(unsigned int tag_num,
292 					       unsigned int tag_size,
293 					       enum target_prot_op sup_prot_ops)
294 {
295 	struct se_session *se_sess;
296 	int rc;
297 
298 	se_sess = transport_init_session(sup_prot_ops);
299 	if (IS_ERR(se_sess))
300 		return se_sess;
301 
302 	rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
303 	if (rc < 0) {
304 		transport_free_session(se_sess);
305 		return ERR_PTR(-ENOMEM);
306 	}
307 
308 	return se_sess;
309 }
310 EXPORT_SYMBOL(transport_init_session_tags);
311 
312 /*
313  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
314  */
315 void __transport_register_session(
316 	struct se_portal_group *se_tpg,
317 	struct se_node_acl *se_nacl,
318 	struct se_session *se_sess,
319 	void *fabric_sess_ptr)
320 {
321 	unsigned char buf[PR_REG_ISID_LEN];
322 
323 	se_sess->se_tpg = se_tpg;
324 	se_sess->fabric_sess_ptr = fabric_sess_ptr;
325 	/*
326 	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
327 	 *
328 	 * Only set for struct se_session's that will actually be moving I/O.
329 	 * eg: *NOT* discovery sessions.
330 	 */
331 	if (se_nacl) {
332 		/*
333 		 * If the fabric module supports an ISID based TransportID,
334 		 * save this value in binary from the fabric I_T Nexus now.
335 		 */
336 		if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
337 			memset(&buf[0], 0, PR_REG_ISID_LEN);
338 			se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
339 					&buf[0], PR_REG_ISID_LEN);
340 			se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
341 		}
342 		kref_get(&se_nacl->acl_kref);
343 
344 		spin_lock_irq(&se_nacl->nacl_sess_lock);
345 		/*
346 		 * The se_nacl->nacl_sess pointer will be set to the
347 		 * last active I_T Nexus for each struct se_node_acl.
348 		 */
349 		se_nacl->nacl_sess = se_sess;
350 
351 		list_add_tail(&se_sess->sess_acl_list,
352 			      &se_nacl->acl_sess_list);
353 		spin_unlock_irq(&se_nacl->nacl_sess_lock);
354 	}
355 	list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
356 
357 	pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
358 		se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
359 }
360 EXPORT_SYMBOL(__transport_register_session);
361 
362 void transport_register_session(
363 	struct se_portal_group *se_tpg,
364 	struct se_node_acl *se_nacl,
365 	struct se_session *se_sess,
366 	void *fabric_sess_ptr)
367 {
368 	unsigned long flags;
369 
370 	spin_lock_irqsave(&se_tpg->session_lock, flags);
371 	__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
372 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
373 }
374 EXPORT_SYMBOL(transport_register_session);
375 
376 static void target_release_session(struct kref *kref)
377 {
378 	struct se_session *se_sess = container_of(kref,
379 			struct se_session, sess_kref);
380 	struct se_portal_group *se_tpg = se_sess->se_tpg;
381 
382 	se_tpg->se_tpg_tfo->close_session(se_sess);
383 }
384 
385 void target_get_session(struct se_session *se_sess)
386 {
387 	kref_get(&se_sess->sess_kref);
388 }
389 EXPORT_SYMBOL(target_get_session);
390 
391 void target_put_session(struct se_session *se_sess)
392 {
393 	struct se_portal_group *tpg = se_sess->se_tpg;
394 
395 	if (tpg->se_tpg_tfo->put_session != NULL) {
396 		tpg->se_tpg_tfo->put_session(se_sess);
397 		return;
398 	}
399 	kref_put(&se_sess->sess_kref, target_release_session);
400 }
401 EXPORT_SYMBOL(target_put_session);
402 
403 static void target_complete_nacl(struct kref *kref)
404 {
405 	struct se_node_acl *nacl = container_of(kref,
406 				struct se_node_acl, acl_kref);
407 
408 	complete(&nacl->acl_free_comp);
409 }
410 
411 void target_put_nacl(struct se_node_acl *nacl)
412 {
413 	kref_put(&nacl->acl_kref, target_complete_nacl);
414 }
415 
416 void transport_deregister_session_configfs(struct se_session *se_sess)
417 {
418 	struct se_node_acl *se_nacl;
419 	unsigned long flags;
420 	/*
421 	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
422 	 */
423 	se_nacl = se_sess->se_node_acl;
424 	if (se_nacl) {
425 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
426 		if (se_nacl->acl_stop == 0)
427 			list_del(&se_sess->sess_acl_list);
428 		/*
429 		 * If the session list is empty, then clear the pointer.
430 		 * Otherwise, set the struct se_session pointer from the tail
431 		 * element of the per struct se_node_acl active session list.
432 		 */
433 		if (list_empty(&se_nacl->acl_sess_list))
434 			se_nacl->nacl_sess = NULL;
435 		else {
436 			se_nacl->nacl_sess = container_of(
437 					se_nacl->acl_sess_list.prev,
438 					struct se_session, sess_acl_list);
439 		}
440 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
441 	}
442 }
443 EXPORT_SYMBOL(transport_deregister_session_configfs);
444 
445 void transport_free_session(struct se_session *se_sess)
446 {
447 	if (se_sess->sess_cmd_map) {
448 		percpu_ida_destroy(&se_sess->sess_tag_pool);
449 		if (is_vmalloc_addr(se_sess->sess_cmd_map))
450 			vfree(se_sess->sess_cmd_map);
451 		else
452 			kfree(se_sess->sess_cmd_map);
453 	}
454 	kmem_cache_free(se_sess_cache, se_sess);
455 }
456 EXPORT_SYMBOL(transport_free_session);
457 
458 void transport_deregister_session(struct se_session *se_sess)
459 {
460 	struct se_portal_group *se_tpg = se_sess->se_tpg;
461 	struct target_core_fabric_ops *se_tfo;
462 	struct se_node_acl *se_nacl;
463 	unsigned long flags;
464 	bool comp_nacl = true;
465 
466 	if (!se_tpg) {
467 		transport_free_session(se_sess);
468 		return;
469 	}
470 	se_tfo = se_tpg->se_tpg_tfo;
471 
472 	spin_lock_irqsave(&se_tpg->session_lock, flags);
473 	list_del(&se_sess->sess_list);
474 	se_sess->se_tpg = NULL;
475 	se_sess->fabric_sess_ptr = NULL;
476 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
477 
478 	/*
479 	 * Determine if we need to do extra work for this initiator node's
480 	 * struct se_node_acl if it had been previously dynamically generated.
481 	 */
482 	se_nacl = se_sess->se_node_acl;
483 
484 	spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
485 	if (se_nacl && se_nacl->dynamic_node_acl) {
486 		if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
487 			list_del(&se_nacl->acl_list);
488 			se_tpg->num_node_acls--;
489 			spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
490 			core_tpg_wait_for_nacl_pr_ref(se_nacl);
491 			core_free_device_list_for_node(se_nacl, se_tpg);
492 			se_tfo->tpg_release_fabric_acl(se_tpg, se_nacl);
493 
494 			comp_nacl = false;
495 			spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
496 		}
497 	}
498 	spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
499 
500 	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
501 		se_tpg->se_tpg_tfo->get_fabric_name());
502 	/*
503 	 * If last kref is dropping now for an explicit NodeACL, awake sleeping
504 	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
505 	 * removal context.
506 	 */
507 	if (se_nacl && comp_nacl)
508 		target_put_nacl(se_nacl);
509 
510 	transport_free_session(se_sess);
511 }
512 EXPORT_SYMBOL(transport_deregister_session);
513 
514 /*
515  * Called with cmd->t_state_lock held.
516  */
517 static void target_remove_from_state_list(struct se_cmd *cmd)
518 {
519 	struct se_device *dev = cmd->se_dev;
520 	unsigned long flags;
521 
522 	if (!dev)
523 		return;
524 
525 	if (cmd->transport_state & CMD_T_BUSY)
526 		return;
527 
528 	spin_lock_irqsave(&dev->execute_task_lock, flags);
529 	if (cmd->state_active) {
530 		list_del(&cmd->state_list);
531 		cmd->state_active = false;
532 	}
533 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
534 }
535 
536 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
537 				    bool write_pending)
538 {
539 	unsigned long flags;
540 
541 	spin_lock_irqsave(&cmd->t_state_lock, flags);
542 	if (write_pending)
543 		cmd->t_state = TRANSPORT_WRITE_PENDING;
544 
545 	if (remove_from_lists) {
546 		target_remove_from_state_list(cmd);
547 
548 		/*
549 		 * Clear struct se_cmd->se_lun before the handoff to FE.
550 		 */
551 		cmd->se_lun = NULL;
552 	}
553 
554 	/*
555 	 * Determine if frontend context caller is requesting the stopping of
556 	 * this command for frontend exceptions.
557 	 */
558 	if (cmd->transport_state & CMD_T_STOP) {
559 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
560 			__func__, __LINE__,
561 			cmd->se_tfo->get_task_tag(cmd));
562 
563 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
564 
565 		complete_all(&cmd->t_transport_stop_comp);
566 		return 1;
567 	}
568 
569 	cmd->transport_state &= ~CMD_T_ACTIVE;
570 	if (remove_from_lists) {
571 		/*
572 		 * Some fabric modules like tcm_loop can release
573 		 * their internally allocated I/O reference now and
574 		 * struct se_cmd now.
575 		 *
576 		 * Fabric modules are expected to return '1' here if the
577 		 * se_cmd being passed is released at this point,
578 		 * or zero if not being released.
579 		 */
580 		if (cmd->se_tfo->check_stop_free != NULL) {
581 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
582 			return cmd->se_tfo->check_stop_free(cmd);
583 		}
584 	}
585 
586 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
587 	return 0;
588 }
589 
590 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
591 {
592 	return transport_cmd_check_stop(cmd, true, false);
593 }
594 
595 static void transport_lun_remove_cmd(struct se_cmd *cmd)
596 {
597 	struct se_lun *lun = cmd->se_lun;
598 
599 	if (!lun)
600 		return;
601 
602 	if (cmpxchg(&cmd->lun_ref_active, true, false))
603 		percpu_ref_put(&lun->lun_ref);
604 }
605 
606 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
607 {
608 	if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
609 		transport_lun_remove_cmd(cmd);
610 	/*
611 	 * Allow the fabric driver to unmap any resources before
612 	 * releasing the descriptor via TFO->release_cmd()
613 	 */
614 	if (remove)
615 		cmd->se_tfo->aborted_task(cmd);
616 
617 	if (transport_cmd_check_stop_to_fabric(cmd))
618 		return;
619 	if (remove)
620 		transport_put_cmd(cmd);
621 }
622 
623 static void target_complete_failure_work(struct work_struct *work)
624 {
625 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
626 
627 	transport_generic_request_failure(cmd,
628 			TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
629 }
630 
631 /*
632  * Used when asking transport to copy Sense Data from the underlying
633  * Linux/SCSI struct scsi_cmnd
634  */
635 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
636 {
637 	struct se_device *dev = cmd->se_dev;
638 
639 	WARN_ON(!cmd->se_lun);
640 
641 	if (!dev)
642 		return NULL;
643 
644 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
645 		return NULL;
646 
647 	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
648 
649 	pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
650 		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
651 	return cmd->sense_buffer;
652 }
653 
654 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
655 {
656 	struct se_device *dev = cmd->se_dev;
657 	int success = scsi_status == GOOD;
658 	unsigned long flags;
659 
660 	cmd->scsi_status = scsi_status;
661 
662 
663 	spin_lock_irqsave(&cmd->t_state_lock, flags);
664 	cmd->transport_state &= ~CMD_T_BUSY;
665 
666 	if (dev && dev->transport->transport_complete) {
667 		dev->transport->transport_complete(cmd,
668 				cmd->t_data_sg,
669 				transport_get_sense_buffer(cmd));
670 		if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
671 			success = 1;
672 	}
673 
674 	/*
675 	 * See if we are waiting to complete for an exception condition.
676 	 */
677 	if (cmd->transport_state & CMD_T_REQUEST_STOP) {
678 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
679 		complete(&cmd->task_stop_comp);
680 		return;
681 	}
682 
683 	/*
684 	 * Check for case where an explicit ABORT_TASK has been received
685 	 * and transport_wait_for_tasks() will be waiting for completion..
686 	 */
687 	if (cmd->transport_state & CMD_T_ABORTED &&
688 	    cmd->transport_state & CMD_T_STOP) {
689 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
690 		complete_all(&cmd->t_transport_stop_comp);
691 		return;
692 	} else if (!success) {
693 		INIT_WORK(&cmd->work, target_complete_failure_work);
694 	} else {
695 		INIT_WORK(&cmd->work, target_complete_ok_work);
696 	}
697 
698 	cmd->t_state = TRANSPORT_COMPLETE;
699 	cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
700 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
701 
702 	queue_work(target_completion_wq, &cmd->work);
703 }
704 EXPORT_SYMBOL(target_complete_cmd);
705 
706 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
707 {
708 	if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
709 		if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
710 			cmd->residual_count += cmd->data_length - length;
711 		} else {
712 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
713 			cmd->residual_count = cmd->data_length - length;
714 		}
715 
716 		cmd->data_length = length;
717 	}
718 
719 	target_complete_cmd(cmd, scsi_status);
720 }
721 EXPORT_SYMBOL(target_complete_cmd_with_length);
722 
723 static void target_add_to_state_list(struct se_cmd *cmd)
724 {
725 	struct se_device *dev = cmd->se_dev;
726 	unsigned long flags;
727 
728 	spin_lock_irqsave(&dev->execute_task_lock, flags);
729 	if (!cmd->state_active) {
730 		list_add_tail(&cmd->state_list, &dev->state_list);
731 		cmd->state_active = true;
732 	}
733 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
734 }
735 
736 /*
737  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
738  */
739 static void transport_write_pending_qf(struct se_cmd *cmd);
740 static void transport_complete_qf(struct se_cmd *cmd);
741 
742 void target_qf_do_work(struct work_struct *work)
743 {
744 	struct se_device *dev = container_of(work, struct se_device,
745 					qf_work_queue);
746 	LIST_HEAD(qf_cmd_list);
747 	struct se_cmd *cmd, *cmd_tmp;
748 
749 	spin_lock_irq(&dev->qf_cmd_lock);
750 	list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
751 	spin_unlock_irq(&dev->qf_cmd_lock);
752 
753 	list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
754 		list_del(&cmd->se_qf_node);
755 		atomic_dec(&dev->dev_qf_count);
756 		smp_mb__after_atomic();
757 
758 		pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
759 			" context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
760 			(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
761 			(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
762 			: "UNKNOWN");
763 
764 		if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
765 			transport_write_pending_qf(cmd);
766 		else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
767 			transport_complete_qf(cmd);
768 	}
769 }
770 
771 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
772 {
773 	switch (cmd->data_direction) {
774 	case DMA_NONE:
775 		return "NONE";
776 	case DMA_FROM_DEVICE:
777 		return "READ";
778 	case DMA_TO_DEVICE:
779 		return "WRITE";
780 	case DMA_BIDIRECTIONAL:
781 		return "BIDI";
782 	default:
783 		break;
784 	}
785 
786 	return "UNKNOWN";
787 }
788 
789 void transport_dump_dev_state(
790 	struct se_device *dev,
791 	char *b,
792 	int *bl)
793 {
794 	*bl += sprintf(b + *bl, "Status: ");
795 	if (dev->export_count)
796 		*bl += sprintf(b + *bl, "ACTIVATED");
797 	else
798 		*bl += sprintf(b + *bl, "DEACTIVATED");
799 
800 	*bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
801 	*bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
802 		dev->dev_attrib.block_size,
803 		dev->dev_attrib.hw_max_sectors);
804 	*bl += sprintf(b + *bl, "        ");
805 }
806 
807 void transport_dump_vpd_proto_id(
808 	struct t10_vpd *vpd,
809 	unsigned char *p_buf,
810 	int p_buf_len)
811 {
812 	unsigned char buf[VPD_TMP_BUF_SIZE];
813 	int len;
814 
815 	memset(buf, 0, VPD_TMP_BUF_SIZE);
816 	len = sprintf(buf, "T10 VPD Protocol Identifier: ");
817 
818 	switch (vpd->protocol_identifier) {
819 	case 0x00:
820 		sprintf(buf+len, "Fibre Channel\n");
821 		break;
822 	case 0x10:
823 		sprintf(buf+len, "Parallel SCSI\n");
824 		break;
825 	case 0x20:
826 		sprintf(buf+len, "SSA\n");
827 		break;
828 	case 0x30:
829 		sprintf(buf+len, "IEEE 1394\n");
830 		break;
831 	case 0x40:
832 		sprintf(buf+len, "SCSI Remote Direct Memory Access"
833 				" Protocol\n");
834 		break;
835 	case 0x50:
836 		sprintf(buf+len, "Internet SCSI (iSCSI)\n");
837 		break;
838 	case 0x60:
839 		sprintf(buf+len, "SAS Serial SCSI Protocol\n");
840 		break;
841 	case 0x70:
842 		sprintf(buf+len, "Automation/Drive Interface Transport"
843 				" Protocol\n");
844 		break;
845 	case 0x80:
846 		sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
847 		break;
848 	default:
849 		sprintf(buf+len, "Unknown 0x%02x\n",
850 				vpd->protocol_identifier);
851 		break;
852 	}
853 
854 	if (p_buf)
855 		strncpy(p_buf, buf, p_buf_len);
856 	else
857 		pr_debug("%s", buf);
858 }
859 
860 void
861 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
862 {
863 	/*
864 	 * Check if the Protocol Identifier Valid (PIV) bit is set..
865 	 *
866 	 * from spc3r23.pdf section 7.5.1
867 	 */
868 	 if (page_83[1] & 0x80) {
869 		vpd->protocol_identifier = (page_83[0] & 0xf0);
870 		vpd->protocol_identifier_set = 1;
871 		transport_dump_vpd_proto_id(vpd, NULL, 0);
872 	}
873 }
874 EXPORT_SYMBOL(transport_set_vpd_proto_id);
875 
876 int transport_dump_vpd_assoc(
877 	struct t10_vpd *vpd,
878 	unsigned char *p_buf,
879 	int p_buf_len)
880 {
881 	unsigned char buf[VPD_TMP_BUF_SIZE];
882 	int ret = 0;
883 	int len;
884 
885 	memset(buf, 0, VPD_TMP_BUF_SIZE);
886 	len = sprintf(buf, "T10 VPD Identifier Association: ");
887 
888 	switch (vpd->association) {
889 	case 0x00:
890 		sprintf(buf+len, "addressed logical unit\n");
891 		break;
892 	case 0x10:
893 		sprintf(buf+len, "target port\n");
894 		break;
895 	case 0x20:
896 		sprintf(buf+len, "SCSI target device\n");
897 		break;
898 	default:
899 		sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
900 		ret = -EINVAL;
901 		break;
902 	}
903 
904 	if (p_buf)
905 		strncpy(p_buf, buf, p_buf_len);
906 	else
907 		pr_debug("%s", buf);
908 
909 	return ret;
910 }
911 
912 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
913 {
914 	/*
915 	 * The VPD identification association..
916 	 *
917 	 * from spc3r23.pdf Section 7.6.3.1 Table 297
918 	 */
919 	vpd->association = (page_83[1] & 0x30);
920 	return transport_dump_vpd_assoc(vpd, NULL, 0);
921 }
922 EXPORT_SYMBOL(transport_set_vpd_assoc);
923 
924 int transport_dump_vpd_ident_type(
925 	struct t10_vpd *vpd,
926 	unsigned char *p_buf,
927 	int p_buf_len)
928 {
929 	unsigned char buf[VPD_TMP_BUF_SIZE];
930 	int ret = 0;
931 	int len;
932 
933 	memset(buf, 0, VPD_TMP_BUF_SIZE);
934 	len = sprintf(buf, "T10 VPD Identifier Type: ");
935 
936 	switch (vpd->device_identifier_type) {
937 	case 0x00:
938 		sprintf(buf+len, "Vendor specific\n");
939 		break;
940 	case 0x01:
941 		sprintf(buf+len, "T10 Vendor ID based\n");
942 		break;
943 	case 0x02:
944 		sprintf(buf+len, "EUI-64 based\n");
945 		break;
946 	case 0x03:
947 		sprintf(buf+len, "NAA\n");
948 		break;
949 	case 0x04:
950 		sprintf(buf+len, "Relative target port identifier\n");
951 		break;
952 	case 0x08:
953 		sprintf(buf+len, "SCSI name string\n");
954 		break;
955 	default:
956 		sprintf(buf+len, "Unsupported: 0x%02x\n",
957 				vpd->device_identifier_type);
958 		ret = -EINVAL;
959 		break;
960 	}
961 
962 	if (p_buf) {
963 		if (p_buf_len < strlen(buf)+1)
964 			return -EINVAL;
965 		strncpy(p_buf, buf, p_buf_len);
966 	} else {
967 		pr_debug("%s", buf);
968 	}
969 
970 	return ret;
971 }
972 
973 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
974 {
975 	/*
976 	 * The VPD identifier type..
977 	 *
978 	 * from spc3r23.pdf Section 7.6.3.1 Table 298
979 	 */
980 	vpd->device_identifier_type = (page_83[1] & 0x0f);
981 	return transport_dump_vpd_ident_type(vpd, NULL, 0);
982 }
983 EXPORT_SYMBOL(transport_set_vpd_ident_type);
984 
985 int transport_dump_vpd_ident(
986 	struct t10_vpd *vpd,
987 	unsigned char *p_buf,
988 	int p_buf_len)
989 {
990 	unsigned char buf[VPD_TMP_BUF_SIZE];
991 	int ret = 0;
992 
993 	memset(buf, 0, VPD_TMP_BUF_SIZE);
994 
995 	switch (vpd->device_identifier_code_set) {
996 	case 0x01: /* Binary */
997 		snprintf(buf, sizeof(buf),
998 			"T10 VPD Binary Device Identifier: %s\n",
999 			&vpd->device_identifier[0]);
1000 		break;
1001 	case 0x02: /* ASCII */
1002 		snprintf(buf, sizeof(buf),
1003 			"T10 VPD ASCII Device Identifier: %s\n",
1004 			&vpd->device_identifier[0]);
1005 		break;
1006 	case 0x03: /* UTF-8 */
1007 		snprintf(buf, sizeof(buf),
1008 			"T10 VPD UTF-8 Device Identifier: %s\n",
1009 			&vpd->device_identifier[0]);
1010 		break;
1011 	default:
1012 		sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1013 			" 0x%02x", vpd->device_identifier_code_set);
1014 		ret = -EINVAL;
1015 		break;
1016 	}
1017 
1018 	if (p_buf)
1019 		strncpy(p_buf, buf, p_buf_len);
1020 	else
1021 		pr_debug("%s", buf);
1022 
1023 	return ret;
1024 }
1025 
1026 int
1027 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1028 {
1029 	static const char hex_str[] = "0123456789abcdef";
1030 	int j = 0, i = 4; /* offset to start of the identifier */
1031 
1032 	/*
1033 	 * The VPD Code Set (encoding)
1034 	 *
1035 	 * from spc3r23.pdf Section 7.6.3.1 Table 296
1036 	 */
1037 	vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1038 	switch (vpd->device_identifier_code_set) {
1039 	case 0x01: /* Binary */
1040 		vpd->device_identifier[j++] =
1041 				hex_str[vpd->device_identifier_type];
1042 		while (i < (4 + page_83[3])) {
1043 			vpd->device_identifier[j++] =
1044 				hex_str[(page_83[i] & 0xf0) >> 4];
1045 			vpd->device_identifier[j++] =
1046 				hex_str[page_83[i] & 0x0f];
1047 			i++;
1048 		}
1049 		break;
1050 	case 0x02: /* ASCII */
1051 	case 0x03: /* UTF-8 */
1052 		while (i < (4 + page_83[3]))
1053 			vpd->device_identifier[j++] = page_83[i++];
1054 		break;
1055 	default:
1056 		break;
1057 	}
1058 
1059 	return transport_dump_vpd_ident(vpd, NULL, 0);
1060 }
1061 EXPORT_SYMBOL(transport_set_vpd_ident);
1062 
1063 sense_reason_t
1064 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1065 {
1066 	struct se_device *dev = cmd->se_dev;
1067 
1068 	if (cmd->unknown_data_length) {
1069 		cmd->data_length = size;
1070 	} else if (size != cmd->data_length) {
1071 		pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1072 			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
1073 			" 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1074 				cmd->data_length, size, cmd->t_task_cdb[0]);
1075 
1076 		if (cmd->data_direction == DMA_TO_DEVICE) {
1077 			pr_err("Rejecting underflow/overflow"
1078 					" WRITE data\n");
1079 			return TCM_INVALID_CDB_FIELD;
1080 		}
1081 		/*
1082 		 * Reject READ_* or WRITE_* with overflow/underflow for
1083 		 * type SCF_SCSI_DATA_CDB.
1084 		 */
1085 		if (dev->dev_attrib.block_size != 512)  {
1086 			pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1087 				" CDB on non 512-byte sector setup subsystem"
1088 				" plugin: %s\n", dev->transport->name);
1089 			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1090 			return TCM_INVALID_CDB_FIELD;
1091 		}
1092 		/*
1093 		 * For the overflow case keep the existing fabric provided
1094 		 * ->data_length.  Otherwise for the underflow case, reset
1095 		 * ->data_length to the smaller SCSI expected data transfer
1096 		 * length.
1097 		 */
1098 		if (size > cmd->data_length) {
1099 			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1100 			cmd->residual_count = (size - cmd->data_length);
1101 		} else {
1102 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1103 			cmd->residual_count = (cmd->data_length - size);
1104 			cmd->data_length = size;
1105 		}
1106 	}
1107 
1108 	return 0;
1109 
1110 }
1111 
1112 /*
1113  * Used by fabric modules containing a local struct se_cmd within their
1114  * fabric dependent per I/O descriptor.
1115  */
1116 void transport_init_se_cmd(
1117 	struct se_cmd *cmd,
1118 	struct target_core_fabric_ops *tfo,
1119 	struct se_session *se_sess,
1120 	u32 data_length,
1121 	int data_direction,
1122 	int task_attr,
1123 	unsigned char *sense_buffer)
1124 {
1125 	INIT_LIST_HEAD(&cmd->se_delayed_node);
1126 	INIT_LIST_HEAD(&cmd->se_qf_node);
1127 	INIT_LIST_HEAD(&cmd->se_cmd_list);
1128 	INIT_LIST_HEAD(&cmd->state_list);
1129 	init_completion(&cmd->t_transport_stop_comp);
1130 	init_completion(&cmd->cmd_wait_comp);
1131 	init_completion(&cmd->task_stop_comp);
1132 	spin_lock_init(&cmd->t_state_lock);
1133 	kref_init(&cmd->cmd_kref);
1134 	cmd->transport_state = CMD_T_DEV_ACTIVE;
1135 
1136 	cmd->se_tfo = tfo;
1137 	cmd->se_sess = se_sess;
1138 	cmd->data_length = data_length;
1139 	cmd->data_direction = data_direction;
1140 	cmd->sam_task_attr = task_attr;
1141 	cmd->sense_buffer = sense_buffer;
1142 
1143 	cmd->state_active = false;
1144 }
1145 EXPORT_SYMBOL(transport_init_se_cmd);
1146 
1147 static sense_reason_t
1148 transport_check_alloc_task_attr(struct se_cmd *cmd)
1149 {
1150 	struct se_device *dev = cmd->se_dev;
1151 
1152 	/*
1153 	 * Check if SAM Task Attribute emulation is enabled for this
1154 	 * struct se_device storage object
1155 	 */
1156 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1157 		return 0;
1158 
1159 	if (cmd->sam_task_attr == MSG_ACA_TAG) {
1160 		pr_debug("SAM Task Attribute ACA"
1161 			" emulation is not supported\n");
1162 		return TCM_INVALID_CDB_FIELD;
1163 	}
1164 	/*
1165 	 * Used to determine when ORDERED commands should go from
1166 	 * Dormant to Active status.
1167 	 */
1168 	cmd->se_ordered_id = atomic_inc_return(&dev->dev_ordered_id);
1169 	smp_mb__after_atomic();
1170 	pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
1171 			cmd->se_ordered_id, cmd->sam_task_attr,
1172 			dev->transport->name);
1173 	return 0;
1174 }
1175 
1176 sense_reason_t
1177 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1178 {
1179 	struct se_device *dev = cmd->se_dev;
1180 	sense_reason_t ret;
1181 
1182 	/*
1183 	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1184 	 * for VARIABLE_LENGTH_CMD
1185 	 */
1186 	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1187 		pr_err("Received SCSI CDB with command_size: %d that"
1188 			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1189 			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1190 		return TCM_INVALID_CDB_FIELD;
1191 	}
1192 	/*
1193 	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1194 	 * allocate the additional extended CDB buffer now..  Otherwise
1195 	 * setup the pointer from __t_task_cdb to t_task_cdb.
1196 	 */
1197 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1198 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1199 						GFP_KERNEL);
1200 		if (!cmd->t_task_cdb) {
1201 			pr_err("Unable to allocate cmd->t_task_cdb"
1202 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1203 				scsi_command_size(cdb),
1204 				(unsigned long)sizeof(cmd->__t_task_cdb));
1205 			return TCM_OUT_OF_RESOURCES;
1206 		}
1207 	} else
1208 		cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1209 	/*
1210 	 * Copy the original CDB into cmd->
1211 	 */
1212 	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1213 
1214 	trace_target_sequencer_start(cmd);
1215 
1216 	/*
1217 	 * Check for an existing UNIT ATTENTION condition
1218 	 */
1219 	ret = target_scsi3_ua_check(cmd);
1220 	if (ret)
1221 		return ret;
1222 
1223 	ret = target_alua_state_check(cmd);
1224 	if (ret)
1225 		return ret;
1226 
1227 	ret = target_check_reservation(cmd);
1228 	if (ret) {
1229 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1230 		return ret;
1231 	}
1232 
1233 	ret = dev->transport->parse_cdb(cmd);
1234 	if (ret)
1235 		return ret;
1236 
1237 	ret = transport_check_alloc_task_attr(cmd);
1238 	if (ret)
1239 		return ret;
1240 
1241 	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1242 
1243 	spin_lock(&cmd->se_lun->lun_sep_lock);
1244 	if (cmd->se_lun->lun_sep)
1245 		cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
1246 	spin_unlock(&cmd->se_lun->lun_sep_lock);
1247 	return 0;
1248 }
1249 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1250 
1251 /*
1252  * Used by fabric module frontends to queue tasks directly.
1253  * Many only be used from process context only
1254  */
1255 int transport_handle_cdb_direct(
1256 	struct se_cmd *cmd)
1257 {
1258 	sense_reason_t ret;
1259 
1260 	if (!cmd->se_lun) {
1261 		dump_stack();
1262 		pr_err("cmd->se_lun is NULL\n");
1263 		return -EINVAL;
1264 	}
1265 	if (in_interrupt()) {
1266 		dump_stack();
1267 		pr_err("transport_generic_handle_cdb cannot be called"
1268 				" from interrupt context\n");
1269 		return -EINVAL;
1270 	}
1271 	/*
1272 	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1273 	 * outstanding descriptors are handled correctly during shutdown via
1274 	 * transport_wait_for_tasks()
1275 	 *
1276 	 * Also, we don't take cmd->t_state_lock here as we only expect
1277 	 * this to be called for initial descriptor submission.
1278 	 */
1279 	cmd->t_state = TRANSPORT_NEW_CMD;
1280 	cmd->transport_state |= CMD_T_ACTIVE;
1281 
1282 	/*
1283 	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1284 	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1285 	 * and call transport_generic_request_failure() if necessary..
1286 	 */
1287 	ret = transport_generic_new_cmd(cmd);
1288 	if (ret)
1289 		transport_generic_request_failure(cmd, ret);
1290 	return 0;
1291 }
1292 EXPORT_SYMBOL(transport_handle_cdb_direct);
1293 
1294 sense_reason_t
1295 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1296 		u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1297 {
1298 	if (!sgl || !sgl_count)
1299 		return 0;
1300 
1301 	/*
1302 	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1303 	 * scatterlists already have been set to follow what the fabric
1304 	 * passes for the original expected data transfer length.
1305 	 */
1306 	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1307 		pr_warn("Rejecting SCSI DATA overflow for fabric using"
1308 			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1309 		return TCM_INVALID_CDB_FIELD;
1310 	}
1311 
1312 	cmd->t_data_sg = sgl;
1313 	cmd->t_data_nents = sgl_count;
1314 
1315 	if (sgl_bidi && sgl_bidi_count) {
1316 		cmd->t_bidi_data_sg = sgl_bidi;
1317 		cmd->t_bidi_data_nents = sgl_bidi_count;
1318 	}
1319 	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1320 	return 0;
1321 }
1322 
1323 /*
1324  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1325  * 			 se_cmd + use pre-allocated SGL memory.
1326  *
1327  * @se_cmd: command descriptor to submit
1328  * @se_sess: associated se_sess for endpoint
1329  * @cdb: pointer to SCSI CDB
1330  * @sense: pointer to SCSI sense buffer
1331  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1332  * @data_length: fabric expected data transfer length
1333  * @task_addr: SAM task attribute
1334  * @data_dir: DMA data direction
1335  * @flags: flags for command submission from target_sc_flags_tables
1336  * @sgl: struct scatterlist memory for unidirectional mapping
1337  * @sgl_count: scatterlist count for unidirectional mapping
1338  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1339  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1340  * @sgl_prot: struct scatterlist memory protection information
1341  * @sgl_prot_count: scatterlist count for protection information
1342  *
1343  * Returns non zero to signal active I/O shutdown failure.  All other
1344  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1345  * but still return zero here.
1346  *
1347  * This may only be called from process context, and also currently
1348  * assumes internal allocation of fabric payload buffer by target-core.
1349  */
1350 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1351 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1352 		u32 data_length, int task_attr, int data_dir, int flags,
1353 		struct scatterlist *sgl, u32 sgl_count,
1354 		struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1355 		struct scatterlist *sgl_prot, u32 sgl_prot_count)
1356 {
1357 	struct se_portal_group *se_tpg;
1358 	sense_reason_t rc;
1359 	int ret;
1360 
1361 	se_tpg = se_sess->se_tpg;
1362 	BUG_ON(!se_tpg);
1363 	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1364 	BUG_ON(in_interrupt());
1365 	/*
1366 	 * Initialize se_cmd for target operation.  From this point
1367 	 * exceptions are handled by sending exception status via
1368 	 * target_core_fabric_ops->queue_status() callback
1369 	 */
1370 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1371 				data_length, data_dir, task_attr, sense);
1372 	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1373 		se_cmd->unknown_data_length = 1;
1374 	/*
1375 	 * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1376 	 * se_sess->sess_cmd_list.  A second kref_get here is necessary
1377 	 * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1378 	 * kref_put() to happen during fabric packet acknowledgement.
1379 	 */
1380 	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1381 	if (ret)
1382 		return ret;
1383 	/*
1384 	 * Signal bidirectional data payloads to target-core
1385 	 */
1386 	if (flags & TARGET_SCF_BIDI_OP)
1387 		se_cmd->se_cmd_flags |= SCF_BIDI;
1388 	/*
1389 	 * Locate se_lun pointer and attach it to struct se_cmd
1390 	 */
1391 	rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1392 	if (rc) {
1393 		transport_send_check_condition_and_sense(se_cmd, rc, 0);
1394 		target_put_sess_cmd(se_sess, se_cmd);
1395 		return 0;
1396 	}
1397 
1398 	rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1399 	if (rc != 0) {
1400 		transport_generic_request_failure(se_cmd, rc);
1401 		return 0;
1402 	}
1403 
1404 	/*
1405 	 * Save pointers for SGLs containing protection information,
1406 	 * if present.
1407 	 */
1408 	if (sgl_prot_count) {
1409 		se_cmd->t_prot_sg = sgl_prot;
1410 		se_cmd->t_prot_nents = sgl_prot_count;
1411 	}
1412 
1413 	/*
1414 	 * When a non zero sgl_count has been passed perform SGL passthrough
1415 	 * mapping for pre-allocated fabric memory instead of having target
1416 	 * core perform an internal SGL allocation..
1417 	 */
1418 	if (sgl_count != 0) {
1419 		BUG_ON(!sgl);
1420 
1421 		/*
1422 		 * A work-around for tcm_loop as some userspace code via
1423 		 * scsi-generic do not memset their associated read buffers,
1424 		 * so go ahead and do that here for type non-data CDBs.  Also
1425 		 * note that this is currently guaranteed to be a single SGL
1426 		 * for this case by target core in target_setup_cmd_from_cdb()
1427 		 * -> transport_generic_cmd_sequencer().
1428 		 */
1429 		if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1430 		     se_cmd->data_direction == DMA_FROM_DEVICE) {
1431 			unsigned char *buf = NULL;
1432 
1433 			if (sgl)
1434 				buf = kmap(sg_page(sgl)) + sgl->offset;
1435 
1436 			if (buf) {
1437 				memset(buf, 0, sgl->length);
1438 				kunmap(sg_page(sgl));
1439 			}
1440 		}
1441 
1442 		rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1443 				sgl_bidi, sgl_bidi_count);
1444 		if (rc != 0) {
1445 			transport_generic_request_failure(se_cmd, rc);
1446 			return 0;
1447 		}
1448 	}
1449 
1450 	/*
1451 	 * Check if we need to delay processing because of ALUA
1452 	 * Active/NonOptimized primary access state..
1453 	 */
1454 	core_alua_check_nonop_delay(se_cmd);
1455 
1456 	transport_handle_cdb_direct(se_cmd);
1457 	return 0;
1458 }
1459 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1460 
1461 /*
1462  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1463  *
1464  * @se_cmd: command descriptor to submit
1465  * @se_sess: associated se_sess for endpoint
1466  * @cdb: pointer to SCSI CDB
1467  * @sense: pointer to SCSI sense buffer
1468  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1469  * @data_length: fabric expected data transfer length
1470  * @task_addr: SAM task attribute
1471  * @data_dir: DMA data direction
1472  * @flags: flags for command submission from target_sc_flags_tables
1473  *
1474  * Returns non zero to signal active I/O shutdown failure.  All other
1475  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1476  * but still return zero here.
1477  *
1478  * This may only be called from process context, and also currently
1479  * assumes internal allocation of fabric payload buffer by target-core.
1480  *
1481  * It also assumes interal target core SGL memory allocation.
1482  */
1483 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1484 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1485 		u32 data_length, int task_attr, int data_dir, int flags)
1486 {
1487 	return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1488 			unpacked_lun, data_length, task_attr, data_dir,
1489 			flags, NULL, 0, NULL, 0, NULL, 0);
1490 }
1491 EXPORT_SYMBOL(target_submit_cmd);
1492 
1493 static void target_complete_tmr_failure(struct work_struct *work)
1494 {
1495 	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1496 
1497 	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1498 	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1499 
1500 	transport_cmd_check_stop_to_fabric(se_cmd);
1501 }
1502 
1503 /**
1504  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1505  *                     for TMR CDBs
1506  *
1507  * @se_cmd: command descriptor to submit
1508  * @se_sess: associated se_sess for endpoint
1509  * @sense: pointer to SCSI sense buffer
1510  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1511  * @fabric_context: fabric context for TMR req
1512  * @tm_type: Type of TM request
1513  * @gfp: gfp type for caller
1514  * @tag: referenced task tag for TMR_ABORT_TASK
1515  * @flags: submit cmd flags
1516  *
1517  * Callable from all contexts.
1518  **/
1519 
1520 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1521 		unsigned char *sense, u32 unpacked_lun,
1522 		void *fabric_tmr_ptr, unsigned char tm_type,
1523 		gfp_t gfp, unsigned int tag, int flags)
1524 {
1525 	struct se_portal_group *se_tpg;
1526 	int ret;
1527 
1528 	se_tpg = se_sess->se_tpg;
1529 	BUG_ON(!se_tpg);
1530 
1531 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1532 			      0, DMA_NONE, MSG_SIMPLE_TAG, sense);
1533 	/*
1534 	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1535 	 * allocation failure.
1536 	 */
1537 	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1538 	if (ret < 0)
1539 		return -ENOMEM;
1540 
1541 	if (tm_type == TMR_ABORT_TASK)
1542 		se_cmd->se_tmr_req->ref_task_tag = tag;
1543 
1544 	/* See target_submit_cmd for commentary */
1545 	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1546 	if (ret) {
1547 		core_tmr_release_req(se_cmd->se_tmr_req);
1548 		return ret;
1549 	}
1550 
1551 	ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1552 	if (ret) {
1553 		/*
1554 		 * For callback during failure handling, push this work off
1555 		 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1556 		 */
1557 		INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1558 		schedule_work(&se_cmd->work);
1559 		return 0;
1560 	}
1561 	transport_generic_handle_tmr(se_cmd);
1562 	return 0;
1563 }
1564 EXPORT_SYMBOL(target_submit_tmr);
1565 
1566 /*
1567  * If the cmd is active, request it to be stopped and sleep until it
1568  * has completed.
1569  */
1570 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1571 {
1572 	bool was_active = false;
1573 
1574 	if (cmd->transport_state & CMD_T_BUSY) {
1575 		cmd->transport_state |= CMD_T_REQUEST_STOP;
1576 		spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1577 
1578 		pr_debug("cmd %p waiting to complete\n", cmd);
1579 		wait_for_completion(&cmd->task_stop_comp);
1580 		pr_debug("cmd %p stopped successfully\n", cmd);
1581 
1582 		spin_lock_irqsave(&cmd->t_state_lock, *flags);
1583 		cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1584 		cmd->transport_state &= ~CMD_T_BUSY;
1585 		was_active = true;
1586 	}
1587 
1588 	return was_active;
1589 }
1590 
1591 /*
1592  * Handle SAM-esque emulation for generic transport request failures.
1593  */
1594 void transport_generic_request_failure(struct se_cmd *cmd,
1595 		sense_reason_t sense_reason)
1596 {
1597 	int ret = 0;
1598 
1599 	pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
1600 		" CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
1601 		cmd->t_task_cdb[0]);
1602 	pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1603 		cmd->se_tfo->get_cmd_state(cmd),
1604 		cmd->t_state, sense_reason);
1605 	pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1606 		(cmd->transport_state & CMD_T_ACTIVE) != 0,
1607 		(cmd->transport_state & CMD_T_STOP) != 0,
1608 		(cmd->transport_state & CMD_T_SENT) != 0);
1609 
1610 	/*
1611 	 * For SAM Task Attribute emulation for failed struct se_cmd
1612 	 */
1613 	transport_complete_task_attr(cmd);
1614 	/*
1615 	 * Handle special case for COMPARE_AND_WRITE failure, where the
1616 	 * callback is expected to drop the per device ->caw_mutex.
1617 	 */
1618 	if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1619 	     cmd->transport_complete_callback)
1620 		cmd->transport_complete_callback(cmd);
1621 
1622 	switch (sense_reason) {
1623 	case TCM_NON_EXISTENT_LUN:
1624 	case TCM_UNSUPPORTED_SCSI_OPCODE:
1625 	case TCM_INVALID_CDB_FIELD:
1626 	case TCM_INVALID_PARAMETER_LIST:
1627 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
1628 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1629 	case TCM_UNKNOWN_MODE_PAGE:
1630 	case TCM_WRITE_PROTECTED:
1631 	case TCM_ADDRESS_OUT_OF_RANGE:
1632 	case TCM_CHECK_CONDITION_ABORT_CMD:
1633 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1634 	case TCM_CHECK_CONDITION_NOT_READY:
1635 	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1636 	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1637 	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1638 		break;
1639 	case TCM_OUT_OF_RESOURCES:
1640 		sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1641 		break;
1642 	case TCM_RESERVATION_CONFLICT:
1643 		/*
1644 		 * No SENSE Data payload for this case, set SCSI Status
1645 		 * and queue the response to $FABRIC_MOD.
1646 		 *
1647 		 * Uses linux/include/scsi/scsi.h SAM status codes defs
1648 		 */
1649 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1650 		/*
1651 		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1652 		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1653 		 * CONFLICT STATUS.
1654 		 *
1655 		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1656 		 */
1657 		if (cmd->se_sess &&
1658 		    cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2)
1659 			core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
1660 				cmd->orig_fe_lun, 0x2C,
1661 				ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1662 
1663 		trace_target_cmd_complete(cmd);
1664 		ret = cmd->se_tfo-> queue_status(cmd);
1665 		if (ret == -EAGAIN || ret == -ENOMEM)
1666 			goto queue_full;
1667 		goto check_stop;
1668 	default:
1669 		pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1670 			cmd->t_task_cdb[0], sense_reason);
1671 		sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1672 		break;
1673 	}
1674 
1675 	ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1676 	if (ret == -EAGAIN || ret == -ENOMEM)
1677 		goto queue_full;
1678 
1679 check_stop:
1680 	transport_lun_remove_cmd(cmd);
1681 	if (!transport_cmd_check_stop_to_fabric(cmd))
1682 		;
1683 	return;
1684 
1685 queue_full:
1686 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1687 	transport_handle_queue_full(cmd, cmd->se_dev);
1688 }
1689 EXPORT_SYMBOL(transport_generic_request_failure);
1690 
1691 void __target_execute_cmd(struct se_cmd *cmd)
1692 {
1693 	sense_reason_t ret;
1694 
1695 	if (cmd->execute_cmd) {
1696 		ret = cmd->execute_cmd(cmd);
1697 		if (ret) {
1698 			spin_lock_irq(&cmd->t_state_lock);
1699 			cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1700 			spin_unlock_irq(&cmd->t_state_lock);
1701 
1702 			transport_generic_request_failure(cmd, ret);
1703 		}
1704 	}
1705 }
1706 
1707 static bool target_handle_task_attr(struct se_cmd *cmd)
1708 {
1709 	struct se_device *dev = cmd->se_dev;
1710 
1711 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1712 		return false;
1713 
1714 	/*
1715 	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1716 	 * to allow the passed struct se_cmd list of tasks to the front of the list.
1717 	 */
1718 	switch (cmd->sam_task_attr) {
1719 	case MSG_HEAD_TAG:
1720 		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
1721 			 "se_ordered_id: %u\n",
1722 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1723 		return false;
1724 	case MSG_ORDERED_TAG:
1725 		atomic_inc(&dev->dev_ordered_sync);
1726 		smp_mb__after_atomic();
1727 
1728 		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
1729 			 " se_ordered_id: %u\n",
1730 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1731 
1732 		/*
1733 		 * Execute an ORDERED command if no other older commands
1734 		 * exist that need to be completed first.
1735 		 */
1736 		if (!atomic_read(&dev->simple_cmds))
1737 			return false;
1738 		break;
1739 	default:
1740 		/*
1741 		 * For SIMPLE and UNTAGGED Task Attribute commands
1742 		 */
1743 		atomic_inc(&dev->simple_cmds);
1744 		smp_mb__after_atomic();
1745 		break;
1746 	}
1747 
1748 	if (atomic_read(&dev->dev_ordered_sync) == 0)
1749 		return false;
1750 
1751 	spin_lock(&dev->delayed_cmd_lock);
1752 	list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1753 	spin_unlock(&dev->delayed_cmd_lock);
1754 
1755 	pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
1756 		" delayed CMD list, se_ordered_id: %u\n",
1757 		cmd->t_task_cdb[0], cmd->sam_task_attr,
1758 		cmd->se_ordered_id);
1759 	return true;
1760 }
1761 
1762 void target_execute_cmd(struct se_cmd *cmd)
1763 {
1764 	/*
1765 	 * If the received CDB has aleady been aborted stop processing it here.
1766 	 */
1767 	if (transport_check_aborted_status(cmd, 1))
1768 		return;
1769 
1770 	/*
1771 	 * Determine if frontend context caller is requesting the stopping of
1772 	 * this command for frontend exceptions.
1773 	 */
1774 	spin_lock_irq(&cmd->t_state_lock);
1775 	if (cmd->transport_state & CMD_T_STOP) {
1776 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
1777 			__func__, __LINE__,
1778 			cmd->se_tfo->get_task_tag(cmd));
1779 
1780 		spin_unlock_irq(&cmd->t_state_lock);
1781 		complete_all(&cmd->t_transport_stop_comp);
1782 		return;
1783 	}
1784 
1785 	cmd->t_state = TRANSPORT_PROCESSING;
1786 	cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1787 	spin_unlock_irq(&cmd->t_state_lock);
1788 	/*
1789 	 * Perform WRITE_INSERT of PI using software emulation when backend
1790 	 * device has PI enabled, if the transport has not already generated
1791 	 * PI using hardware WRITE_INSERT offload.
1792 	 */
1793 	if (cmd->prot_op == TARGET_PROT_DOUT_INSERT) {
1794 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1795 			sbc_dif_generate(cmd);
1796 	}
1797 
1798 	if (target_handle_task_attr(cmd)) {
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 		return;
1803 	}
1804 
1805 	__target_execute_cmd(cmd);
1806 }
1807 EXPORT_SYMBOL(target_execute_cmd);
1808 
1809 /*
1810  * Process all commands up to the last received ORDERED task attribute which
1811  * requires another blocking boundary
1812  */
1813 static void target_restart_delayed_cmds(struct se_device *dev)
1814 {
1815 	for (;;) {
1816 		struct se_cmd *cmd;
1817 
1818 		spin_lock(&dev->delayed_cmd_lock);
1819 		if (list_empty(&dev->delayed_cmd_list)) {
1820 			spin_unlock(&dev->delayed_cmd_lock);
1821 			break;
1822 		}
1823 
1824 		cmd = list_entry(dev->delayed_cmd_list.next,
1825 				 struct se_cmd, se_delayed_node);
1826 		list_del(&cmd->se_delayed_node);
1827 		spin_unlock(&dev->delayed_cmd_lock);
1828 
1829 		__target_execute_cmd(cmd);
1830 
1831 		if (cmd->sam_task_attr == MSG_ORDERED_TAG)
1832 			break;
1833 	}
1834 }
1835 
1836 /*
1837  * Called from I/O completion to determine which dormant/delayed
1838  * and ordered cmds need to have their tasks added to the execution queue.
1839  */
1840 static void transport_complete_task_attr(struct se_cmd *cmd)
1841 {
1842 	struct se_device *dev = cmd->se_dev;
1843 
1844 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1845 		return;
1846 
1847 	if (cmd->sam_task_attr == MSG_SIMPLE_TAG) {
1848 		atomic_dec(&dev->simple_cmds);
1849 		smp_mb__after_atomic();
1850 		dev->dev_cur_ordered_id++;
1851 		pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
1852 			" SIMPLE: %u\n", dev->dev_cur_ordered_id,
1853 			cmd->se_ordered_id);
1854 	} else if (cmd->sam_task_attr == MSG_HEAD_TAG) {
1855 		dev->dev_cur_ordered_id++;
1856 		pr_debug("Incremented dev_cur_ordered_id: %u for"
1857 			" HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
1858 			cmd->se_ordered_id);
1859 	} else if (cmd->sam_task_attr == MSG_ORDERED_TAG) {
1860 		atomic_dec(&dev->dev_ordered_sync);
1861 		smp_mb__after_atomic();
1862 
1863 		dev->dev_cur_ordered_id++;
1864 		pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
1865 			" %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
1866 	}
1867 
1868 	target_restart_delayed_cmds(dev);
1869 }
1870 
1871 static void transport_complete_qf(struct se_cmd *cmd)
1872 {
1873 	int ret = 0;
1874 
1875 	transport_complete_task_attr(cmd);
1876 
1877 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1878 		trace_target_cmd_complete(cmd);
1879 		ret = cmd->se_tfo->queue_status(cmd);
1880 		if (ret)
1881 			goto out;
1882 	}
1883 
1884 	switch (cmd->data_direction) {
1885 	case DMA_FROM_DEVICE:
1886 		trace_target_cmd_complete(cmd);
1887 		ret = cmd->se_tfo->queue_data_in(cmd);
1888 		break;
1889 	case DMA_TO_DEVICE:
1890 		if (cmd->se_cmd_flags & SCF_BIDI) {
1891 			ret = cmd->se_tfo->queue_data_in(cmd);
1892 			if (ret < 0)
1893 				break;
1894 		}
1895 		/* Fall through for DMA_TO_DEVICE */
1896 	case DMA_NONE:
1897 		trace_target_cmd_complete(cmd);
1898 		ret = cmd->se_tfo->queue_status(cmd);
1899 		break;
1900 	default:
1901 		break;
1902 	}
1903 
1904 out:
1905 	if (ret < 0) {
1906 		transport_handle_queue_full(cmd, cmd->se_dev);
1907 		return;
1908 	}
1909 	transport_lun_remove_cmd(cmd);
1910 	transport_cmd_check_stop_to_fabric(cmd);
1911 }
1912 
1913 static void transport_handle_queue_full(
1914 	struct se_cmd *cmd,
1915 	struct se_device *dev)
1916 {
1917 	spin_lock_irq(&dev->qf_cmd_lock);
1918 	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
1919 	atomic_inc(&dev->dev_qf_count);
1920 	smp_mb__after_atomic();
1921 	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
1922 
1923 	schedule_work(&cmd->se_dev->qf_work_queue);
1924 }
1925 
1926 static bool target_check_read_strip(struct se_cmd *cmd)
1927 {
1928 	sense_reason_t rc;
1929 
1930 	if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
1931 		rc = sbc_dif_read_strip(cmd);
1932 		if (rc) {
1933 			cmd->pi_err = rc;
1934 			return true;
1935 		}
1936 	}
1937 
1938 	return false;
1939 }
1940 
1941 static void target_complete_ok_work(struct work_struct *work)
1942 {
1943 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
1944 	int ret;
1945 
1946 	/*
1947 	 * Check if we need to move delayed/dormant tasks from cmds on the
1948 	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
1949 	 * Attribute.
1950 	 */
1951 	transport_complete_task_attr(cmd);
1952 
1953 	/*
1954 	 * Check to schedule QUEUE_FULL work, or execute an existing
1955 	 * cmd->transport_qf_callback()
1956 	 */
1957 	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
1958 		schedule_work(&cmd->se_dev->qf_work_queue);
1959 
1960 	/*
1961 	 * Check if we need to send a sense buffer from
1962 	 * the struct se_cmd in question.
1963 	 */
1964 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1965 		WARN_ON(!cmd->scsi_status);
1966 		ret = transport_send_check_condition_and_sense(
1967 					cmd, 0, 1);
1968 		if (ret == -EAGAIN || ret == -ENOMEM)
1969 			goto queue_full;
1970 
1971 		transport_lun_remove_cmd(cmd);
1972 		transport_cmd_check_stop_to_fabric(cmd);
1973 		return;
1974 	}
1975 	/*
1976 	 * Check for a callback, used by amongst other things
1977 	 * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
1978 	 */
1979 	if (cmd->transport_complete_callback) {
1980 		sense_reason_t rc;
1981 
1982 		rc = cmd->transport_complete_callback(cmd);
1983 		if (!rc && !(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE_POST)) {
1984 			return;
1985 		} else if (rc) {
1986 			ret = transport_send_check_condition_and_sense(cmd,
1987 						rc, 0);
1988 			if (ret == -EAGAIN || ret == -ENOMEM)
1989 				goto queue_full;
1990 
1991 			transport_lun_remove_cmd(cmd);
1992 			transport_cmd_check_stop_to_fabric(cmd);
1993 			return;
1994 		}
1995 	}
1996 
1997 	switch (cmd->data_direction) {
1998 	case DMA_FROM_DEVICE:
1999 		spin_lock(&cmd->se_lun->lun_sep_lock);
2000 		if (cmd->se_lun->lun_sep) {
2001 			cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
2002 					cmd->data_length;
2003 		}
2004 		spin_unlock(&cmd->se_lun->lun_sep_lock);
2005 		/*
2006 		 * Perform READ_STRIP of PI using software emulation when
2007 		 * backend had PI enabled, if the transport will not be
2008 		 * performing hardware READ_STRIP offload.
2009 		 */
2010 		if (cmd->prot_op == TARGET_PROT_DIN_STRIP &&
2011 		    target_check_read_strip(cmd)) {
2012 			ret = transport_send_check_condition_and_sense(cmd,
2013 						cmd->pi_err, 0);
2014 			if (ret == -EAGAIN || ret == -ENOMEM)
2015 				goto queue_full;
2016 
2017 			transport_lun_remove_cmd(cmd);
2018 			transport_cmd_check_stop_to_fabric(cmd);
2019 			return;
2020 		}
2021 
2022 		trace_target_cmd_complete(cmd);
2023 		ret = cmd->se_tfo->queue_data_in(cmd);
2024 		if (ret == -EAGAIN || ret == -ENOMEM)
2025 			goto queue_full;
2026 		break;
2027 	case DMA_TO_DEVICE:
2028 		spin_lock(&cmd->se_lun->lun_sep_lock);
2029 		if (cmd->se_lun->lun_sep) {
2030 			cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
2031 				cmd->data_length;
2032 		}
2033 		spin_unlock(&cmd->se_lun->lun_sep_lock);
2034 		/*
2035 		 * Check if we need to send READ payload for BIDI-COMMAND
2036 		 */
2037 		if (cmd->se_cmd_flags & SCF_BIDI) {
2038 			spin_lock(&cmd->se_lun->lun_sep_lock);
2039 			if (cmd->se_lun->lun_sep) {
2040 				cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
2041 					cmd->data_length;
2042 			}
2043 			spin_unlock(&cmd->se_lun->lun_sep_lock);
2044 			ret = cmd->se_tfo->queue_data_in(cmd);
2045 			if (ret == -EAGAIN || ret == -ENOMEM)
2046 				goto queue_full;
2047 			break;
2048 		}
2049 		/* Fall through for DMA_TO_DEVICE */
2050 	case DMA_NONE:
2051 		trace_target_cmd_complete(cmd);
2052 		ret = cmd->se_tfo->queue_status(cmd);
2053 		if (ret == -EAGAIN || ret == -ENOMEM)
2054 			goto queue_full;
2055 		break;
2056 	default:
2057 		break;
2058 	}
2059 
2060 	transport_lun_remove_cmd(cmd);
2061 	transport_cmd_check_stop_to_fabric(cmd);
2062 	return;
2063 
2064 queue_full:
2065 	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2066 		" data_direction: %d\n", cmd, cmd->data_direction);
2067 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2068 	transport_handle_queue_full(cmd, cmd->se_dev);
2069 }
2070 
2071 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
2072 {
2073 	struct scatterlist *sg;
2074 	int count;
2075 
2076 	for_each_sg(sgl, sg, nents, count)
2077 		__free_page(sg_page(sg));
2078 
2079 	kfree(sgl);
2080 }
2081 
2082 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2083 {
2084 	/*
2085 	 * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2086 	 * emulation, and free + reset pointers if necessary..
2087 	 */
2088 	if (!cmd->t_data_sg_orig)
2089 		return;
2090 
2091 	kfree(cmd->t_data_sg);
2092 	cmd->t_data_sg = cmd->t_data_sg_orig;
2093 	cmd->t_data_sg_orig = NULL;
2094 	cmd->t_data_nents = cmd->t_data_nents_orig;
2095 	cmd->t_data_nents_orig = 0;
2096 }
2097 
2098 static inline void transport_free_pages(struct se_cmd *cmd)
2099 {
2100 	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2101 		transport_reset_sgl_orig(cmd);
2102 		return;
2103 	}
2104 	transport_reset_sgl_orig(cmd);
2105 
2106 	transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2107 	cmd->t_data_sg = NULL;
2108 	cmd->t_data_nents = 0;
2109 
2110 	transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2111 	cmd->t_bidi_data_sg = NULL;
2112 	cmd->t_bidi_data_nents = 0;
2113 
2114 	transport_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2115 	cmd->t_prot_sg = NULL;
2116 	cmd->t_prot_nents = 0;
2117 }
2118 
2119 /**
2120  * transport_release_cmd - free a command
2121  * @cmd:       command to free
2122  *
2123  * This routine unconditionally frees a command, and reference counting
2124  * or list removal must be done in the caller.
2125  */
2126 static int transport_release_cmd(struct se_cmd *cmd)
2127 {
2128 	BUG_ON(!cmd->se_tfo);
2129 
2130 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2131 		core_tmr_release_req(cmd->se_tmr_req);
2132 	if (cmd->t_task_cdb != cmd->__t_task_cdb)
2133 		kfree(cmd->t_task_cdb);
2134 	/*
2135 	 * If this cmd has been setup with target_get_sess_cmd(), drop
2136 	 * the kref and call ->release_cmd() in kref callback.
2137 	 */
2138 	return target_put_sess_cmd(cmd->se_sess, cmd);
2139 }
2140 
2141 /**
2142  * transport_put_cmd - release a reference to a command
2143  * @cmd:       command to release
2144  *
2145  * This routine releases our reference to the command and frees it if possible.
2146  */
2147 static int transport_put_cmd(struct se_cmd *cmd)
2148 {
2149 	transport_free_pages(cmd);
2150 	return transport_release_cmd(cmd);
2151 }
2152 
2153 void *transport_kmap_data_sg(struct se_cmd *cmd)
2154 {
2155 	struct scatterlist *sg = cmd->t_data_sg;
2156 	struct page **pages;
2157 	int i;
2158 
2159 	/*
2160 	 * We need to take into account a possible offset here for fabrics like
2161 	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2162 	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2163 	 */
2164 	if (!cmd->t_data_nents)
2165 		return NULL;
2166 
2167 	BUG_ON(!sg);
2168 	if (cmd->t_data_nents == 1)
2169 		return kmap(sg_page(sg)) + sg->offset;
2170 
2171 	/* >1 page. use vmap */
2172 	pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2173 	if (!pages)
2174 		return NULL;
2175 
2176 	/* convert sg[] to pages[] */
2177 	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2178 		pages[i] = sg_page(sg);
2179 	}
2180 
2181 	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2182 	kfree(pages);
2183 	if (!cmd->t_data_vmap)
2184 		return NULL;
2185 
2186 	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2187 }
2188 EXPORT_SYMBOL(transport_kmap_data_sg);
2189 
2190 void transport_kunmap_data_sg(struct se_cmd *cmd)
2191 {
2192 	if (!cmd->t_data_nents) {
2193 		return;
2194 	} else if (cmd->t_data_nents == 1) {
2195 		kunmap(sg_page(cmd->t_data_sg));
2196 		return;
2197 	}
2198 
2199 	vunmap(cmd->t_data_vmap);
2200 	cmd->t_data_vmap = NULL;
2201 }
2202 EXPORT_SYMBOL(transport_kunmap_data_sg);
2203 
2204 int
2205 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2206 		 bool zero_page)
2207 {
2208 	struct scatterlist *sg;
2209 	struct page *page;
2210 	gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2211 	unsigned int nent;
2212 	int i = 0;
2213 
2214 	nent = DIV_ROUND_UP(length, PAGE_SIZE);
2215 	sg = kmalloc(sizeof(struct scatterlist) * nent, GFP_KERNEL);
2216 	if (!sg)
2217 		return -ENOMEM;
2218 
2219 	sg_init_table(sg, nent);
2220 
2221 	while (length) {
2222 		u32 page_len = min_t(u32, length, PAGE_SIZE);
2223 		page = alloc_page(GFP_KERNEL | zero_flag);
2224 		if (!page)
2225 			goto out;
2226 
2227 		sg_set_page(&sg[i], page, page_len, 0);
2228 		length -= page_len;
2229 		i++;
2230 	}
2231 	*sgl = sg;
2232 	*nents = nent;
2233 	return 0;
2234 
2235 out:
2236 	while (i > 0) {
2237 		i--;
2238 		__free_page(sg_page(&sg[i]));
2239 	}
2240 	kfree(sg);
2241 	return -ENOMEM;
2242 }
2243 
2244 /*
2245  * Allocate any required resources to execute the command.  For writes we
2246  * might not have the payload yet, so notify the fabric via a call to
2247  * ->write_pending instead. Otherwise place it on the execution queue.
2248  */
2249 sense_reason_t
2250 transport_generic_new_cmd(struct se_cmd *cmd)
2251 {
2252 	int ret = 0;
2253 
2254 	/*
2255 	 * Determine is the TCM fabric module has already allocated physical
2256 	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2257 	 * beforehand.
2258 	 */
2259 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2260 	    cmd->data_length) {
2261 		bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2262 
2263 		if ((cmd->se_cmd_flags & SCF_BIDI) ||
2264 		    (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2265 			u32 bidi_length;
2266 
2267 			if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2268 				bidi_length = cmd->t_task_nolb *
2269 					      cmd->se_dev->dev_attrib.block_size;
2270 			else
2271 				bidi_length = cmd->data_length;
2272 
2273 			ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2274 					       &cmd->t_bidi_data_nents,
2275 					       bidi_length, zero_flag);
2276 			if (ret < 0)
2277 				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2278 		}
2279 
2280 		if (cmd->prot_op != TARGET_PROT_NORMAL) {
2281 			ret = target_alloc_sgl(&cmd->t_prot_sg,
2282 					       &cmd->t_prot_nents,
2283 					       cmd->prot_length, true);
2284 			if (ret < 0)
2285 				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2286 		}
2287 
2288 		ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2289 				       cmd->data_length, zero_flag);
2290 		if (ret < 0)
2291 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2292 	}
2293 	/*
2294 	 * If this command is not a write we can execute it right here,
2295 	 * for write buffers we need to notify the fabric driver first
2296 	 * and let it call back once the write buffers are ready.
2297 	 */
2298 	target_add_to_state_list(cmd);
2299 	if (cmd->data_direction != DMA_TO_DEVICE) {
2300 		target_execute_cmd(cmd);
2301 		return 0;
2302 	}
2303 	transport_cmd_check_stop(cmd, false, true);
2304 
2305 	ret = cmd->se_tfo->write_pending(cmd);
2306 	if (ret == -EAGAIN || ret == -ENOMEM)
2307 		goto queue_full;
2308 
2309 	/* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2310 	WARN_ON(ret);
2311 
2312 	return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2313 
2314 queue_full:
2315 	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2316 	cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2317 	transport_handle_queue_full(cmd, cmd->se_dev);
2318 	return 0;
2319 }
2320 EXPORT_SYMBOL(transport_generic_new_cmd);
2321 
2322 static void transport_write_pending_qf(struct se_cmd *cmd)
2323 {
2324 	int ret;
2325 
2326 	ret = cmd->se_tfo->write_pending(cmd);
2327 	if (ret == -EAGAIN || ret == -ENOMEM) {
2328 		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2329 			 cmd);
2330 		transport_handle_queue_full(cmd, cmd->se_dev);
2331 	}
2332 }
2333 
2334 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2335 {
2336 	unsigned long flags;
2337 	int ret = 0;
2338 
2339 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2340 		if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2341 			 transport_wait_for_tasks(cmd);
2342 
2343 		ret = transport_release_cmd(cmd);
2344 	} else {
2345 		if (wait_for_tasks)
2346 			transport_wait_for_tasks(cmd);
2347 		/*
2348 		 * Handle WRITE failure case where transport_generic_new_cmd()
2349 		 * has already added se_cmd to state_list, but fabric has
2350 		 * failed command before I/O submission.
2351 		 */
2352 		if (cmd->state_active) {
2353 			spin_lock_irqsave(&cmd->t_state_lock, flags);
2354 			target_remove_from_state_list(cmd);
2355 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2356 		}
2357 
2358 		if (cmd->se_lun)
2359 			transport_lun_remove_cmd(cmd);
2360 
2361 		ret = transport_put_cmd(cmd);
2362 	}
2363 	return ret;
2364 }
2365 EXPORT_SYMBOL(transport_generic_free_cmd);
2366 
2367 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2368  * @se_sess:	session to reference
2369  * @se_cmd:	command descriptor to add
2370  * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
2371  */
2372 int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
2373 			       bool ack_kref)
2374 {
2375 	unsigned long flags;
2376 	int ret = 0;
2377 
2378 	/*
2379 	 * Add a second kref if the fabric caller is expecting to handle
2380 	 * fabric acknowledgement that requires two target_put_sess_cmd()
2381 	 * invocations before se_cmd descriptor release.
2382 	 */
2383 	if (ack_kref) {
2384 		kref_get(&se_cmd->cmd_kref);
2385 		se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2386 	}
2387 
2388 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2389 	if (se_sess->sess_tearing_down) {
2390 		ret = -ESHUTDOWN;
2391 		goto out;
2392 	}
2393 	list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2394 out:
2395 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2396 	return ret;
2397 }
2398 EXPORT_SYMBOL(target_get_sess_cmd);
2399 
2400 static void target_release_cmd_kref(struct kref *kref)
2401 {
2402 	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2403 	struct se_session *se_sess = se_cmd->se_sess;
2404 
2405 	if (list_empty(&se_cmd->se_cmd_list)) {
2406 		spin_unlock(&se_sess->sess_cmd_lock);
2407 		se_cmd->se_tfo->release_cmd(se_cmd);
2408 		return;
2409 	}
2410 	if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2411 		spin_unlock(&se_sess->sess_cmd_lock);
2412 		complete(&se_cmd->cmd_wait_comp);
2413 		return;
2414 	}
2415 	list_del(&se_cmd->se_cmd_list);
2416 	spin_unlock(&se_sess->sess_cmd_lock);
2417 
2418 	se_cmd->se_tfo->release_cmd(se_cmd);
2419 }
2420 
2421 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2422  * @se_sess:	session to reference
2423  * @se_cmd:	command descriptor to drop
2424  */
2425 int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd)
2426 {
2427 	if (!se_sess) {
2428 		se_cmd->se_tfo->release_cmd(se_cmd);
2429 		return 1;
2430 	}
2431 	return kref_put_spinlock_irqsave(&se_cmd->cmd_kref, target_release_cmd_kref,
2432 			&se_sess->sess_cmd_lock);
2433 }
2434 EXPORT_SYMBOL(target_put_sess_cmd);
2435 
2436 /* target_sess_cmd_list_set_waiting - Flag all commands in
2437  *         sess_cmd_list to complete cmd_wait_comp.  Set
2438  *         sess_tearing_down so no more commands are queued.
2439  * @se_sess:	session to flag
2440  */
2441 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2442 {
2443 	struct se_cmd *se_cmd;
2444 	unsigned long flags;
2445 
2446 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2447 	if (se_sess->sess_tearing_down) {
2448 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2449 		return;
2450 	}
2451 	se_sess->sess_tearing_down = 1;
2452 	list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2453 
2454 	list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list)
2455 		se_cmd->cmd_wait_set = 1;
2456 
2457 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2458 }
2459 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2460 
2461 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2462  * @se_sess:    session to wait for active I/O
2463  */
2464 void target_wait_for_sess_cmds(struct se_session *se_sess)
2465 {
2466 	struct se_cmd *se_cmd, *tmp_cmd;
2467 	unsigned long flags;
2468 
2469 	list_for_each_entry_safe(se_cmd, tmp_cmd,
2470 				&se_sess->sess_wait_list, se_cmd_list) {
2471 		list_del(&se_cmd->se_cmd_list);
2472 
2473 		pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2474 			" %d\n", se_cmd, se_cmd->t_state,
2475 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2476 
2477 		wait_for_completion(&se_cmd->cmd_wait_comp);
2478 		pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2479 			" fabric state: %d\n", se_cmd, se_cmd->t_state,
2480 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2481 
2482 		se_cmd->se_tfo->release_cmd(se_cmd);
2483 	}
2484 
2485 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2486 	WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2487 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2488 
2489 }
2490 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2491 
2492 static int transport_clear_lun_ref_thread(void *p)
2493 {
2494 	struct se_lun *lun = p;
2495 
2496 	percpu_ref_kill(&lun->lun_ref);
2497 
2498 	wait_for_completion(&lun->lun_ref_comp);
2499 	complete(&lun->lun_shutdown_comp);
2500 
2501 	return 0;
2502 }
2503 
2504 int transport_clear_lun_ref(struct se_lun *lun)
2505 {
2506 	struct task_struct *kt;
2507 
2508 	kt = kthread_run(transport_clear_lun_ref_thread, lun,
2509 			"tcm_cl_%u", lun->unpacked_lun);
2510 	if (IS_ERR(kt)) {
2511 		pr_err("Unable to start clear_lun thread\n");
2512 		return PTR_ERR(kt);
2513 	}
2514 	wait_for_completion(&lun->lun_shutdown_comp);
2515 
2516 	return 0;
2517 }
2518 
2519 /**
2520  * transport_wait_for_tasks - wait for completion to occur
2521  * @cmd:	command to wait
2522  *
2523  * Called from frontend fabric context to wait for storage engine
2524  * to pause and/or release frontend generated struct se_cmd.
2525  */
2526 bool transport_wait_for_tasks(struct se_cmd *cmd)
2527 {
2528 	unsigned long flags;
2529 
2530 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2531 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2532 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2533 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2534 		return false;
2535 	}
2536 
2537 	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2538 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2539 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2540 		return false;
2541 	}
2542 
2543 	if (!(cmd->transport_state & CMD_T_ACTIVE)) {
2544 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2545 		return false;
2546 	}
2547 
2548 	cmd->transport_state |= CMD_T_STOP;
2549 
2550 	pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
2551 		" i_state: %d, t_state: %d, CMD_T_STOP\n",
2552 		cmd, cmd->se_tfo->get_task_tag(cmd),
2553 		cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2554 
2555 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2556 
2557 	wait_for_completion(&cmd->t_transport_stop_comp);
2558 
2559 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2560 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2561 
2562 	pr_debug("wait_for_tasks: Stopped wait_for_completion("
2563 		"&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
2564 		cmd->se_tfo->get_task_tag(cmd));
2565 
2566 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2567 
2568 	return true;
2569 }
2570 EXPORT_SYMBOL(transport_wait_for_tasks);
2571 
2572 static int transport_get_sense_codes(
2573 	struct se_cmd *cmd,
2574 	u8 *asc,
2575 	u8 *ascq)
2576 {
2577 	*asc = cmd->scsi_asc;
2578 	*ascq = cmd->scsi_ascq;
2579 
2580 	return 0;
2581 }
2582 
2583 static
2584 void transport_err_sector_info(unsigned char *buffer, sector_t bad_sector)
2585 {
2586 	/* Place failed LBA in sense data information descriptor 0. */
2587 	buffer[SPC_ADD_SENSE_LEN_OFFSET] = 0xc;
2588 	buffer[SPC_DESC_TYPE_OFFSET] = 0; /* Information */
2589 	buffer[SPC_ADDITIONAL_DESC_LEN_OFFSET] = 0xa;
2590 	buffer[SPC_VALIDITY_OFFSET] = 0x80;
2591 
2592 	/* Descriptor Information: failing sector */
2593 	put_unaligned_be64(bad_sector, &buffer[12]);
2594 }
2595 
2596 int
2597 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2598 		sense_reason_t reason, int from_transport)
2599 {
2600 	unsigned char *buffer = cmd->sense_buffer;
2601 	unsigned long flags;
2602 	u8 asc = 0, ascq = 0;
2603 
2604 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2605 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2606 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2607 		return 0;
2608 	}
2609 	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2610 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2611 
2612 	if (!reason && from_transport)
2613 		goto after_reason;
2614 
2615 	if (!from_transport)
2616 		cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2617 
2618 	/*
2619 	 * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
2620 	 * SENSE KEY values from include/scsi/scsi.h
2621 	 */
2622 	switch (reason) {
2623 	case TCM_NO_SENSE:
2624 		/* CURRENT ERROR */
2625 		buffer[0] = 0x70;
2626 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2627 		/* Not Ready */
2628 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2629 		/* NO ADDITIONAL SENSE INFORMATION */
2630 		buffer[SPC_ASC_KEY_OFFSET] = 0;
2631 		buffer[SPC_ASCQ_KEY_OFFSET] = 0;
2632 		break;
2633 	case TCM_NON_EXISTENT_LUN:
2634 		/* CURRENT ERROR */
2635 		buffer[0] = 0x70;
2636 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2637 		/* ILLEGAL REQUEST */
2638 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2639 		/* LOGICAL UNIT NOT SUPPORTED */
2640 		buffer[SPC_ASC_KEY_OFFSET] = 0x25;
2641 		break;
2642 	case TCM_UNSUPPORTED_SCSI_OPCODE:
2643 	case TCM_SECTOR_COUNT_TOO_MANY:
2644 		/* CURRENT ERROR */
2645 		buffer[0] = 0x70;
2646 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2647 		/* ILLEGAL REQUEST */
2648 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2649 		/* INVALID COMMAND OPERATION CODE */
2650 		buffer[SPC_ASC_KEY_OFFSET] = 0x20;
2651 		break;
2652 	case TCM_UNKNOWN_MODE_PAGE:
2653 		/* CURRENT ERROR */
2654 		buffer[0] = 0x70;
2655 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2656 		/* ILLEGAL REQUEST */
2657 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2658 		/* INVALID FIELD IN CDB */
2659 		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2660 		break;
2661 	case TCM_CHECK_CONDITION_ABORT_CMD:
2662 		/* CURRENT ERROR */
2663 		buffer[0] = 0x70;
2664 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2665 		/* ABORTED COMMAND */
2666 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2667 		/* BUS DEVICE RESET FUNCTION OCCURRED */
2668 		buffer[SPC_ASC_KEY_OFFSET] = 0x29;
2669 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2670 		break;
2671 	case TCM_INCORRECT_AMOUNT_OF_DATA:
2672 		/* CURRENT ERROR */
2673 		buffer[0] = 0x70;
2674 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2675 		/* ABORTED COMMAND */
2676 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2677 		/* WRITE ERROR */
2678 		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2679 		/* NOT ENOUGH UNSOLICITED DATA */
2680 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0d;
2681 		break;
2682 	case TCM_INVALID_CDB_FIELD:
2683 		/* CURRENT ERROR */
2684 		buffer[0] = 0x70;
2685 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2686 		/* ILLEGAL REQUEST */
2687 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2688 		/* INVALID FIELD IN CDB */
2689 		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2690 		break;
2691 	case TCM_INVALID_PARAMETER_LIST:
2692 		/* CURRENT ERROR */
2693 		buffer[0] = 0x70;
2694 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2695 		/* ILLEGAL REQUEST */
2696 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2697 		/* INVALID FIELD IN PARAMETER LIST */
2698 		buffer[SPC_ASC_KEY_OFFSET] = 0x26;
2699 		break;
2700 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
2701 		/* CURRENT ERROR */
2702 		buffer[0] = 0x70;
2703 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2704 		/* ILLEGAL REQUEST */
2705 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2706 		/* PARAMETER LIST LENGTH ERROR */
2707 		buffer[SPC_ASC_KEY_OFFSET] = 0x1a;
2708 		break;
2709 	case TCM_UNEXPECTED_UNSOLICITED_DATA:
2710 		/* CURRENT ERROR */
2711 		buffer[0] = 0x70;
2712 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2713 		/* ABORTED COMMAND */
2714 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2715 		/* WRITE ERROR */
2716 		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2717 		/* UNEXPECTED_UNSOLICITED_DATA */
2718 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0c;
2719 		break;
2720 	case TCM_SERVICE_CRC_ERROR:
2721 		/* CURRENT ERROR */
2722 		buffer[0] = 0x70;
2723 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2724 		/* ABORTED COMMAND */
2725 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2726 		/* PROTOCOL SERVICE CRC ERROR */
2727 		buffer[SPC_ASC_KEY_OFFSET] = 0x47;
2728 		/* N/A */
2729 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x05;
2730 		break;
2731 	case TCM_SNACK_REJECTED:
2732 		/* CURRENT ERROR */
2733 		buffer[0] = 0x70;
2734 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2735 		/* ABORTED COMMAND */
2736 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2737 		/* READ ERROR */
2738 		buffer[SPC_ASC_KEY_OFFSET] = 0x11;
2739 		/* FAILED RETRANSMISSION REQUEST */
2740 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x13;
2741 		break;
2742 	case TCM_WRITE_PROTECTED:
2743 		/* CURRENT ERROR */
2744 		buffer[0] = 0x70;
2745 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2746 		/* DATA PROTECT */
2747 		buffer[SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
2748 		/* WRITE PROTECTED */
2749 		buffer[SPC_ASC_KEY_OFFSET] = 0x27;
2750 		break;
2751 	case TCM_ADDRESS_OUT_OF_RANGE:
2752 		/* CURRENT ERROR */
2753 		buffer[0] = 0x70;
2754 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2755 		/* ILLEGAL REQUEST */
2756 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2757 		/* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2758 		buffer[SPC_ASC_KEY_OFFSET] = 0x21;
2759 		break;
2760 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2761 		/* CURRENT ERROR */
2762 		buffer[0] = 0x70;
2763 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2764 		/* UNIT ATTENTION */
2765 		buffer[SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
2766 		core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2767 		buffer[SPC_ASC_KEY_OFFSET] = asc;
2768 		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2769 		break;
2770 	case TCM_CHECK_CONDITION_NOT_READY:
2771 		/* CURRENT ERROR */
2772 		buffer[0] = 0x70;
2773 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2774 		/* Not Ready */
2775 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2776 		transport_get_sense_codes(cmd, &asc, &ascq);
2777 		buffer[SPC_ASC_KEY_OFFSET] = asc;
2778 		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2779 		break;
2780 	case TCM_MISCOMPARE_VERIFY:
2781 		/* CURRENT ERROR */
2782 		buffer[0] = 0x70;
2783 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2784 		buffer[SPC_SENSE_KEY_OFFSET] = MISCOMPARE;
2785 		/* MISCOMPARE DURING VERIFY OPERATION */
2786 		buffer[SPC_ASC_KEY_OFFSET] = 0x1d;
2787 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x00;
2788 		break;
2789 	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
2790 		/* CURRENT ERROR */
2791 		buffer[0] = 0x70;
2792 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2793 		/* ILLEGAL REQUEST */
2794 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2795 		/* LOGICAL BLOCK GUARD CHECK FAILED */
2796 		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2797 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x01;
2798 		transport_err_sector_info(buffer, cmd->bad_sector);
2799 		break;
2800 	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
2801 		/* CURRENT ERROR */
2802 		buffer[0] = 0x70;
2803 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2804 		/* ILLEGAL REQUEST */
2805 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2806 		/* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2807 		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2808 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x02;
2809 		transport_err_sector_info(buffer, cmd->bad_sector);
2810 		break;
2811 	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
2812 		/* CURRENT ERROR */
2813 		buffer[0] = 0x70;
2814 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2815 		/* ILLEGAL REQUEST */
2816 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2817 		/* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2818 		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2819 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2820 		transport_err_sector_info(buffer, cmd->bad_sector);
2821 		break;
2822 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
2823 	default:
2824 		/* CURRENT ERROR */
2825 		buffer[0] = 0x70;
2826 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2827 		/*
2828 		 * Returning ILLEGAL REQUEST would cause immediate IO errors on
2829 		 * Solaris initiators.  Returning NOT READY instead means the
2830 		 * operations will be retried a finite number of times and we
2831 		 * can survive intermittent errors.
2832 		 */
2833 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2834 		/* LOGICAL UNIT COMMUNICATION FAILURE */
2835 		buffer[SPC_ASC_KEY_OFFSET] = 0x08;
2836 		break;
2837 	}
2838 	/*
2839 	 * This code uses linux/include/scsi/scsi.h SAM status codes!
2840 	 */
2841 	cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2842 	/*
2843 	 * Automatically padded, this value is encoded in the fabric's
2844 	 * data_length response PDU containing the SCSI defined sense data.
2845 	 */
2846 	cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2847 
2848 after_reason:
2849 	trace_target_cmd_complete(cmd);
2850 	return cmd->se_tfo->queue_status(cmd);
2851 }
2852 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2853 
2854 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2855 {
2856 	if (!(cmd->transport_state & CMD_T_ABORTED))
2857 		return 0;
2858 
2859 	/*
2860 	 * If cmd has been aborted but either no status is to be sent or it has
2861 	 * already been sent, just return
2862 	 */
2863 	if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS))
2864 		return 1;
2865 
2866 	pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08x\n",
2867 		 cmd->t_task_cdb[0], cmd->se_tfo->get_task_tag(cmd));
2868 
2869 	cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
2870 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2871 	trace_target_cmd_complete(cmd);
2872 	cmd->se_tfo->queue_status(cmd);
2873 
2874 	return 1;
2875 }
2876 EXPORT_SYMBOL(transport_check_aborted_status);
2877 
2878 void transport_send_task_abort(struct se_cmd *cmd)
2879 {
2880 	unsigned long flags;
2881 
2882 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2883 	if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
2884 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2885 		return;
2886 	}
2887 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2888 
2889 	/*
2890 	 * If there are still expected incoming fabric WRITEs, we wait
2891 	 * until until they have completed before sending a TASK_ABORTED
2892 	 * response.  This response with TASK_ABORTED status will be
2893 	 * queued back to fabric module by transport_check_aborted_status().
2894 	 */
2895 	if (cmd->data_direction == DMA_TO_DEVICE) {
2896 		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
2897 			cmd->transport_state |= CMD_T_ABORTED;
2898 			cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
2899 			smp_mb__after_atomic();
2900 			return;
2901 		}
2902 	}
2903 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2904 
2905 	transport_lun_remove_cmd(cmd);
2906 
2907 	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
2908 		" ITT: 0x%08x\n", cmd->t_task_cdb[0],
2909 		cmd->se_tfo->get_task_tag(cmd));
2910 
2911 	trace_target_cmd_complete(cmd);
2912 	cmd->se_tfo->queue_status(cmd);
2913 }
2914 
2915 static void target_tmr_work(struct work_struct *work)
2916 {
2917 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2918 	struct se_device *dev = cmd->se_dev;
2919 	struct se_tmr_req *tmr = cmd->se_tmr_req;
2920 	int ret;
2921 
2922 	switch (tmr->function) {
2923 	case TMR_ABORT_TASK:
2924 		core_tmr_abort_task(dev, tmr, cmd->se_sess);
2925 		break;
2926 	case TMR_ABORT_TASK_SET:
2927 	case TMR_CLEAR_ACA:
2928 	case TMR_CLEAR_TASK_SET:
2929 		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
2930 		break;
2931 	case TMR_LUN_RESET:
2932 		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
2933 		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
2934 					 TMR_FUNCTION_REJECTED;
2935 		break;
2936 	case TMR_TARGET_WARM_RESET:
2937 		tmr->response = TMR_FUNCTION_REJECTED;
2938 		break;
2939 	case TMR_TARGET_COLD_RESET:
2940 		tmr->response = TMR_FUNCTION_REJECTED;
2941 		break;
2942 	default:
2943 		pr_err("Uknown TMR function: 0x%02x.\n",
2944 				tmr->function);
2945 		tmr->response = TMR_FUNCTION_REJECTED;
2946 		break;
2947 	}
2948 
2949 	cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
2950 	cmd->se_tfo->queue_tm_rsp(cmd);
2951 
2952 	transport_cmd_check_stop_to_fabric(cmd);
2953 }
2954 
2955 int transport_generic_handle_tmr(
2956 	struct se_cmd *cmd)
2957 {
2958 	unsigned long flags;
2959 
2960 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2961 	cmd->transport_state |= CMD_T_ACTIVE;
2962 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2963 
2964 	INIT_WORK(&cmd->work, target_tmr_work);
2965 	queue_work(cmd->se_dev->tmr_wq, &cmd->work);
2966 	return 0;
2967 }
2968 EXPORT_SYMBOL(transport_generic_handle_tmr);
2969