xref: /openbmc/linux/drivers/target/target_core_transport.c (revision f677b30b487ca3763c3de3f1b4d8c976c2961cd1)
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 
66 static void transport_complete_task_attr(struct se_cmd *cmd);
67 static void transport_handle_queue_full(struct se_cmd *cmd,
68 		struct se_device *dev);
69 static int transport_put_cmd(struct se_cmd *cmd);
70 static void target_complete_ok_work(struct work_struct *work);
71 
72 int init_se_kmem_caches(void)
73 {
74 	se_sess_cache = kmem_cache_create("se_sess_cache",
75 			sizeof(struct se_session), __alignof__(struct se_session),
76 			0, NULL);
77 	if (!se_sess_cache) {
78 		pr_err("kmem_cache_create() for struct se_session"
79 				" failed\n");
80 		goto out;
81 	}
82 	se_ua_cache = kmem_cache_create("se_ua_cache",
83 			sizeof(struct se_ua), __alignof__(struct se_ua),
84 			0, NULL);
85 	if (!se_ua_cache) {
86 		pr_err("kmem_cache_create() for struct se_ua failed\n");
87 		goto out_free_sess_cache;
88 	}
89 	t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
90 			sizeof(struct t10_pr_registration),
91 			__alignof__(struct t10_pr_registration), 0, NULL);
92 	if (!t10_pr_reg_cache) {
93 		pr_err("kmem_cache_create() for struct t10_pr_registration"
94 				" failed\n");
95 		goto out_free_ua_cache;
96 	}
97 	t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
98 			sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
99 			0, NULL);
100 	if (!t10_alua_lu_gp_cache) {
101 		pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
102 				" failed\n");
103 		goto out_free_pr_reg_cache;
104 	}
105 	t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
106 			sizeof(struct t10_alua_lu_gp_member),
107 			__alignof__(struct t10_alua_lu_gp_member), 0, NULL);
108 	if (!t10_alua_lu_gp_mem_cache) {
109 		pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
110 				"cache failed\n");
111 		goto out_free_lu_gp_cache;
112 	}
113 	t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
114 			sizeof(struct t10_alua_tg_pt_gp),
115 			__alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
116 	if (!t10_alua_tg_pt_gp_cache) {
117 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
118 				"cache failed\n");
119 		goto out_free_lu_gp_mem_cache;
120 	}
121 	t10_alua_tg_pt_gp_mem_cache = kmem_cache_create(
122 			"t10_alua_tg_pt_gp_mem_cache",
123 			sizeof(struct t10_alua_tg_pt_gp_member),
124 			__alignof__(struct t10_alua_tg_pt_gp_member),
125 			0, NULL);
126 	if (!t10_alua_tg_pt_gp_mem_cache) {
127 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
128 				"mem_t failed\n");
129 		goto out_free_tg_pt_gp_cache;
130 	}
131 
132 	target_completion_wq = alloc_workqueue("target_completion",
133 					       WQ_MEM_RECLAIM, 0);
134 	if (!target_completion_wq)
135 		goto out_free_tg_pt_gp_mem_cache;
136 
137 	return 0;
138 
139 out_free_tg_pt_gp_mem_cache:
140 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
141 out_free_tg_pt_gp_cache:
142 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
143 out_free_lu_gp_mem_cache:
144 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
145 out_free_lu_gp_cache:
146 	kmem_cache_destroy(t10_alua_lu_gp_cache);
147 out_free_pr_reg_cache:
148 	kmem_cache_destroy(t10_pr_reg_cache);
149 out_free_ua_cache:
150 	kmem_cache_destroy(se_ua_cache);
151 out_free_sess_cache:
152 	kmem_cache_destroy(se_sess_cache);
153 out:
154 	return -ENOMEM;
155 }
156 
157 void release_se_kmem_caches(void)
158 {
159 	destroy_workqueue(target_completion_wq);
160 	kmem_cache_destroy(se_sess_cache);
161 	kmem_cache_destroy(se_ua_cache);
162 	kmem_cache_destroy(t10_pr_reg_cache);
163 	kmem_cache_destroy(t10_alua_lu_gp_cache);
164 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
165 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
166 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
167 }
168 
169 /* This code ensures unique mib indexes are handed out. */
170 static DEFINE_SPINLOCK(scsi_mib_index_lock);
171 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
172 
173 /*
174  * Allocate a new row index for the entry type specified
175  */
176 u32 scsi_get_new_index(scsi_index_t type)
177 {
178 	u32 new_index;
179 
180 	BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
181 
182 	spin_lock(&scsi_mib_index_lock);
183 	new_index = ++scsi_mib_index[type];
184 	spin_unlock(&scsi_mib_index_lock);
185 
186 	return new_index;
187 }
188 
189 void transport_subsystem_check_init(void)
190 {
191 	int ret;
192 	static int sub_api_initialized;
193 
194 	if (sub_api_initialized)
195 		return;
196 
197 	ret = request_module("target_core_iblock");
198 	if (ret != 0)
199 		pr_err("Unable to load target_core_iblock\n");
200 
201 	ret = request_module("target_core_file");
202 	if (ret != 0)
203 		pr_err("Unable to load target_core_file\n");
204 
205 	ret = request_module("target_core_pscsi");
206 	if (ret != 0)
207 		pr_err("Unable to load target_core_pscsi\n");
208 
209 	sub_api_initialized = 1;
210 }
211 
212 struct se_session *transport_init_session(void)
213 {
214 	struct se_session *se_sess;
215 
216 	se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
217 	if (!se_sess) {
218 		pr_err("Unable to allocate struct se_session from"
219 				" se_sess_cache\n");
220 		return ERR_PTR(-ENOMEM);
221 	}
222 	INIT_LIST_HEAD(&se_sess->sess_list);
223 	INIT_LIST_HEAD(&se_sess->sess_acl_list);
224 	INIT_LIST_HEAD(&se_sess->sess_cmd_list);
225 	INIT_LIST_HEAD(&se_sess->sess_wait_list);
226 	spin_lock_init(&se_sess->sess_cmd_lock);
227 	kref_init(&se_sess->sess_kref);
228 
229 	return se_sess;
230 }
231 EXPORT_SYMBOL(transport_init_session);
232 
233 int transport_alloc_session_tags(struct se_session *se_sess,
234 			         unsigned int tag_num, unsigned int tag_size)
235 {
236 	int rc;
237 
238 	se_sess->sess_cmd_map = kzalloc(tag_num * tag_size,
239 					GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
240 	if (!se_sess->sess_cmd_map) {
241 		se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
242 		if (!se_sess->sess_cmd_map) {
243 			pr_err("Unable to allocate se_sess->sess_cmd_map\n");
244 			return -ENOMEM;
245 		}
246 	}
247 
248 	rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
249 	if (rc < 0) {
250 		pr_err("Unable to init se_sess->sess_tag_pool,"
251 			" tag_num: %u\n", tag_num);
252 		if (is_vmalloc_addr(se_sess->sess_cmd_map))
253 			vfree(se_sess->sess_cmd_map);
254 		else
255 			kfree(se_sess->sess_cmd_map);
256 		se_sess->sess_cmd_map = NULL;
257 		return -ENOMEM;
258 	}
259 
260 	return 0;
261 }
262 EXPORT_SYMBOL(transport_alloc_session_tags);
263 
264 struct se_session *transport_init_session_tags(unsigned int tag_num,
265 					       unsigned int tag_size)
266 {
267 	struct se_session *se_sess;
268 	int rc;
269 
270 	se_sess = transport_init_session();
271 	if (IS_ERR(se_sess))
272 		return se_sess;
273 
274 	rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
275 	if (rc < 0) {
276 		transport_free_session(se_sess);
277 		return ERR_PTR(-ENOMEM);
278 	}
279 
280 	return se_sess;
281 }
282 EXPORT_SYMBOL(transport_init_session_tags);
283 
284 /*
285  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
286  */
287 void __transport_register_session(
288 	struct se_portal_group *se_tpg,
289 	struct se_node_acl *se_nacl,
290 	struct se_session *se_sess,
291 	void *fabric_sess_ptr)
292 {
293 	unsigned char buf[PR_REG_ISID_LEN];
294 
295 	se_sess->se_tpg = se_tpg;
296 	se_sess->fabric_sess_ptr = fabric_sess_ptr;
297 	/*
298 	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
299 	 *
300 	 * Only set for struct se_session's that will actually be moving I/O.
301 	 * eg: *NOT* discovery sessions.
302 	 */
303 	if (se_nacl) {
304 		/*
305 		 * If the fabric module supports an ISID based TransportID,
306 		 * save this value in binary from the fabric I_T Nexus now.
307 		 */
308 		if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
309 			memset(&buf[0], 0, PR_REG_ISID_LEN);
310 			se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
311 					&buf[0], PR_REG_ISID_LEN);
312 			se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
313 		}
314 		kref_get(&se_nacl->acl_kref);
315 
316 		spin_lock_irq(&se_nacl->nacl_sess_lock);
317 		/*
318 		 * The se_nacl->nacl_sess pointer will be set to the
319 		 * last active I_T Nexus for each struct se_node_acl.
320 		 */
321 		se_nacl->nacl_sess = se_sess;
322 
323 		list_add_tail(&se_sess->sess_acl_list,
324 			      &se_nacl->acl_sess_list);
325 		spin_unlock_irq(&se_nacl->nacl_sess_lock);
326 	}
327 	list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
328 
329 	pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
330 		se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
331 }
332 EXPORT_SYMBOL(__transport_register_session);
333 
334 void transport_register_session(
335 	struct se_portal_group *se_tpg,
336 	struct se_node_acl *se_nacl,
337 	struct se_session *se_sess,
338 	void *fabric_sess_ptr)
339 {
340 	unsigned long flags;
341 
342 	spin_lock_irqsave(&se_tpg->session_lock, flags);
343 	__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
344 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
345 }
346 EXPORT_SYMBOL(transport_register_session);
347 
348 static void target_release_session(struct kref *kref)
349 {
350 	struct se_session *se_sess = container_of(kref,
351 			struct se_session, sess_kref);
352 	struct se_portal_group *se_tpg = se_sess->se_tpg;
353 
354 	se_tpg->se_tpg_tfo->close_session(se_sess);
355 }
356 
357 void target_get_session(struct se_session *se_sess)
358 {
359 	kref_get(&se_sess->sess_kref);
360 }
361 EXPORT_SYMBOL(target_get_session);
362 
363 void target_put_session(struct se_session *se_sess)
364 {
365 	struct se_portal_group *tpg = se_sess->se_tpg;
366 
367 	if (tpg->se_tpg_tfo->put_session != NULL) {
368 		tpg->se_tpg_tfo->put_session(se_sess);
369 		return;
370 	}
371 	kref_put(&se_sess->sess_kref, target_release_session);
372 }
373 EXPORT_SYMBOL(target_put_session);
374 
375 static void target_complete_nacl(struct kref *kref)
376 {
377 	struct se_node_acl *nacl = container_of(kref,
378 				struct se_node_acl, acl_kref);
379 
380 	complete(&nacl->acl_free_comp);
381 }
382 
383 void target_put_nacl(struct se_node_acl *nacl)
384 {
385 	kref_put(&nacl->acl_kref, target_complete_nacl);
386 }
387 
388 void transport_deregister_session_configfs(struct se_session *se_sess)
389 {
390 	struct se_node_acl *se_nacl;
391 	unsigned long flags;
392 	/*
393 	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
394 	 */
395 	se_nacl = se_sess->se_node_acl;
396 	if (se_nacl) {
397 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
398 		if (se_nacl->acl_stop == 0)
399 			list_del(&se_sess->sess_acl_list);
400 		/*
401 		 * If the session list is empty, then clear the pointer.
402 		 * Otherwise, set the struct se_session pointer from the tail
403 		 * element of the per struct se_node_acl active session list.
404 		 */
405 		if (list_empty(&se_nacl->acl_sess_list))
406 			se_nacl->nacl_sess = NULL;
407 		else {
408 			se_nacl->nacl_sess = container_of(
409 					se_nacl->acl_sess_list.prev,
410 					struct se_session, sess_acl_list);
411 		}
412 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
413 	}
414 }
415 EXPORT_SYMBOL(transport_deregister_session_configfs);
416 
417 void transport_free_session(struct se_session *se_sess)
418 {
419 	if (se_sess->sess_cmd_map) {
420 		percpu_ida_destroy(&se_sess->sess_tag_pool);
421 		if (is_vmalloc_addr(se_sess->sess_cmd_map))
422 			vfree(se_sess->sess_cmd_map);
423 		else
424 			kfree(se_sess->sess_cmd_map);
425 	}
426 	kmem_cache_free(se_sess_cache, se_sess);
427 }
428 EXPORT_SYMBOL(transport_free_session);
429 
430 void transport_deregister_session(struct se_session *se_sess)
431 {
432 	struct se_portal_group *se_tpg = se_sess->se_tpg;
433 	struct target_core_fabric_ops *se_tfo;
434 	struct se_node_acl *se_nacl;
435 	unsigned long flags;
436 	bool comp_nacl = true;
437 
438 	if (!se_tpg) {
439 		transport_free_session(se_sess);
440 		return;
441 	}
442 	se_tfo = se_tpg->se_tpg_tfo;
443 
444 	spin_lock_irqsave(&se_tpg->session_lock, flags);
445 	list_del(&se_sess->sess_list);
446 	se_sess->se_tpg = NULL;
447 	se_sess->fabric_sess_ptr = NULL;
448 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
449 
450 	/*
451 	 * Determine if we need to do extra work for this initiator node's
452 	 * struct se_node_acl if it had been previously dynamically generated.
453 	 */
454 	se_nacl = se_sess->se_node_acl;
455 
456 	spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
457 	if (se_nacl && se_nacl->dynamic_node_acl) {
458 		if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
459 			list_del(&se_nacl->acl_list);
460 			se_tpg->num_node_acls--;
461 			spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
462 			core_tpg_wait_for_nacl_pr_ref(se_nacl);
463 			core_free_device_list_for_node(se_nacl, se_tpg);
464 			se_tfo->tpg_release_fabric_acl(se_tpg, se_nacl);
465 
466 			comp_nacl = false;
467 			spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
468 		}
469 	}
470 	spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
471 
472 	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
473 		se_tpg->se_tpg_tfo->get_fabric_name());
474 	/*
475 	 * If last kref is dropping now for an explicit NodeACL, awake sleeping
476 	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
477 	 * removal context.
478 	 */
479 	if (se_nacl && comp_nacl == true)
480 		target_put_nacl(se_nacl);
481 
482 	transport_free_session(se_sess);
483 }
484 EXPORT_SYMBOL(transport_deregister_session);
485 
486 /*
487  * Called with cmd->t_state_lock held.
488  */
489 static void target_remove_from_state_list(struct se_cmd *cmd)
490 {
491 	struct se_device *dev = cmd->se_dev;
492 	unsigned long flags;
493 
494 	if (!dev)
495 		return;
496 
497 	if (cmd->transport_state & CMD_T_BUSY)
498 		return;
499 
500 	spin_lock_irqsave(&dev->execute_task_lock, flags);
501 	if (cmd->state_active) {
502 		list_del(&cmd->state_list);
503 		cmd->state_active = false;
504 	}
505 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
506 }
507 
508 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
509 				    bool write_pending)
510 {
511 	unsigned long flags;
512 
513 	spin_lock_irqsave(&cmd->t_state_lock, flags);
514 	if (write_pending)
515 		cmd->t_state = TRANSPORT_WRITE_PENDING;
516 
517 	if (remove_from_lists) {
518 		target_remove_from_state_list(cmd);
519 
520 		/*
521 		 * Clear struct se_cmd->se_lun before the handoff to FE.
522 		 */
523 		cmd->se_lun = NULL;
524 	}
525 
526 	/*
527 	 * Determine if frontend context caller is requesting the stopping of
528 	 * this command for frontend exceptions.
529 	 */
530 	if (cmd->transport_state & CMD_T_STOP) {
531 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
532 			__func__, __LINE__,
533 			cmd->se_tfo->get_task_tag(cmd));
534 
535 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
536 
537 		complete(&cmd->t_transport_stop_comp);
538 		return 1;
539 	}
540 
541 	cmd->transport_state &= ~CMD_T_ACTIVE;
542 	if (remove_from_lists) {
543 		/*
544 		 * Some fabric modules like tcm_loop can release
545 		 * their internally allocated I/O reference now and
546 		 * struct se_cmd now.
547 		 *
548 		 * Fabric modules are expected to return '1' here if the
549 		 * se_cmd being passed is released at this point,
550 		 * or zero if not being released.
551 		 */
552 		if (cmd->se_tfo->check_stop_free != NULL) {
553 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
554 			return cmd->se_tfo->check_stop_free(cmd);
555 		}
556 	}
557 
558 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
559 	return 0;
560 }
561 
562 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
563 {
564 	return transport_cmd_check_stop(cmd, true, false);
565 }
566 
567 static void transport_lun_remove_cmd(struct se_cmd *cmd)
568 {
569 	struct se_lun *lun = cmd->se_lun;
570 
571 	if (!lun || !cmd->lun_ref_active)
572 		return;
573 
574 	percpu_ref_put(&lun->lun_ref);
575 }
576 
577 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
578 {
579 	if (transport_cmd_check_stop_to_fabric(cmd))
580 		return;
581 	if (remove)
582 		transport_put_cmd(cmd);
583 }
584 
585 static void target_complete_failure_work(struct work_struct *work)
586 {
587 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
588 
589 	transport_generic_request_failure(cmd,
590 			TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
591 }
592 
593 /*
594  * Used when asking transport to copy Sense Data from the underlying
595  * Linux/SCSI struct scsi_cmnd
596  */
597 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
598 {
599 	struct se_device *dev = cmd->se_dev;
600 
601 	WARN_ON(!cmd->se_lun);
602 
603 	if (!dev)
604 		return NULL;
605 
606 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
607 		return NULL;
608 
609 	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
610 
611 	pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
612 		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
613 	return cmd->sense_buffer;
614 }
615 
616 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
617 {
618 	struct se_device *dev = cmd->se_dev;
619 	int success = scsi_status == GOOD;
620 	unsigned long flags;
621 
622 	cmd->scsi_status = scsi_status;
623 
624 
625 	spin_lock_irqsave(&cmd->t_state_lock, flags);
626 	cmd->transport_state &= ~CMD_T_BUSY;
627 
628 	if (dev && dev->transport->transport_complete) {
629 		dev->transport->transport_complete(cmd,
630 				cmd->t_data_sg,
631 				transport_get_sense_buffer(cmd));
632 		if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
633 			success = 1;
634 	}
635 
636 	/*
637 	 * See if we are waiting to complete for an exception condition.
638 	 */
639 	if (cmd->transport_state & CMD_T_REQUEST_STOP) {
640 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
641 		complete(&cmd->task_stop_comp);
642 		return;
643 	}
644 
645 	if (!success)
646 		cmd->transport_state |= CMD_T_FAILED;
647 
648 	/*
649 	 * Check for case where an explicit ABORT_TASK has been received
650 	 * and transport_wait_for_tasks() will be waiting for completion..
651 	 */
652 	if (cmd->transport_state & CMD_T_ABORTED &&
653 	    cmd->transport_state & CMD_T_STOP) {
654 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
655 		complete(&cmd->t_transport_stop_comp);
656 		return;
657 	} else if (cmd->transport_state & CMD_T_FAILED) {
658 		INIT_WORK(&cmd->work, target_complete_failure_work);
659 	} else {
660 		INIT_WORK(&cmd->work, target_complete_ok_work);
661 	}
662 
663 	cmd->t_state = TRANSPORT_COMPLETE;
664 	cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
665 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
666 
667 	queue_work(target_completion_wq, &cmd->work);
668 }
669 EXPORT_SYMBOL(target_complete_cmd);
670 
671 static void target_add_to_state_list(struct se_cmd *cmd)
672 {
673 	struct se_device *dev = cmd->se_dev;
674 	unsigned long flags;
675 
676 	spin_lock_irqsave(&dev->execute_task_lock, flags);
677 	if (!cmd->state_active) {
678 		list_add_tail(&cmd->state_list, &dev->state_list);
679 		cmd->state_active = true;
680 	}
681 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
682 }
683 
684 /*
685  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
686  */
687 static void transport_write_pending_qf(struct se_cmd *cmd);
688 static void transport_complete_qf(struct se_cmd *cmd);
689 
690 void target_qf_do_work(struct work_struct *work)
691 {
692 	struct se_device *dev = container_of(work, struct se_device,
693 					qf_work_queue);
694 	LIST_HEAD(qf_cmd_list);
695 	struct se_cmd *cmd, *cmd_tmp;
696 
697 	spin_lock_irq(&dev->qf_cmd_lock);
698 	list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
699 	spin_unlock_irq(&dev->qf_cmd_lock);
700 
701 	list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
702 		list_del(&cmd->se_qf_node);
703 		atomic_dec(&dev->dev_qf_count);
704 		smp_mb__after_atomic_dec();
705 
706 		pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
707 			" context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
708 			(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
709 			(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
710 			: "UNKNOWN");
711 
712 		if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
713 			transport_write_pending_qf(cmd);
714 		else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK)
715 			transport_complete_qf(cmd);
716 	}
717 }
718 
719 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
720 {
721 	switch (cmd->data_direction) {
722 	case DMA_NONE:
723 		return "NONE";
724 	case DMA_FROM_DEVICE:
725 		return "READ";
726 	case DMA_TO_DEVICE:
727 		return "WRITE";
728 	case DMA_BIDIRECTIONAL:
729 		return "BIDI";
730 	default:
731 		break;
732 	}
733 
734 	return "UNKNOWN";
735 }
736 
737 void transport_dump_dev_state(
738 	struct se_device *dev,
739 	char *b,
740 	int *bl)
741 {
742 	*bl += sprintf(b + *bl, "Status: ");
743 	if (dev->export_count)
744 		*bl += sprintf(b + *bl, "ACTIVATED");
745 	else
746 		*bl += sprintf(b + *bl, "DEACTIVATED");
747 
748 	*bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
749 	*bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
750 		dev->dev_attrib.block_size,
751 		dev->dev_attrib.hw_max_sectors);
752 	*bl += sprintf(b + *bl, "        ");
753 }
754 
755 void transport_dump_vpd_proto_id(
756 	struct t10_vpd *vpd,
757 	unsigned char *p_buf,
758 	int p_buf_len)
759 {
760 	unsigned char buf[VPD_TMP_BUF_SIZE];
761 	int len;
762 
763 	memset(buf, 0, VPD_TMP_BUF_SIZE);
764 	len = sprintf(buf, "T10 VPD Protocol Identifier: ");
765 
766 	switch (vpd->protocol_identifier) {
767 	case 0x00:
768 		sprintf(buf+len, "Fibre Channel\n");
769 		break;
770 	case 0x10:
771 		sprintf(buf+len, "Parallel SCSI\n");
772 		break;
773 	case 0x20:
774 		sprintf(buf+len, "SSA\n");
775 		break;
776 	case 0x30:
777 		sprintf(buf+len, "IEEE 1394\n");
778 		break;
779 	case 0x40:
780 		sprintf(buf+len, "SCSI Remote Direct Memory Access"
781 				" Protocol\n");
782 		break;
783 	case 0x50:
784 		sprintf(buf+len, "Internet SCSI (iSCSI)\n");
785 		break;
786 	case 0x60:
787 		sprintf(buf+len, "SAS Serial SCSI Protocol\n");
788 		break;
789 	case 0x70:
790 		sprintf(buf+len, "Automation/Drive Interface Transport"
791 				" Protocol\n");
792 		break;
793 	case 0x80:
794 		sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
795 		break;
796 	default:
797 		sprintf(buf+len, "Unknown 0x%02x\n",
798 				vpd->protocol_identifier);
799 		break;
800 	}
801 
802 	if (p_buf)
803 		strncpy(p_buf, buf, p_buf_len);
804 	else
805 		pr_debug("%s", buf);
806 }
807 
808 void
809 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
810 {
811 	/*
812 	 * Check if the Protocol Identifier Valid (PIV) bit is set..
813 	 *
814 	 * from spc3r23.pdf section 7.5.1
815 	 */
816 	 if (page_83[1] & 0x80) {
817 		vpd->protocol_identifier = (page_83[0] & 0xf0);
818 		vpd->protocol_identifier_set = 1;
819 		transport_dump_vpd_proto_id(vpd, NULL, 0);
820 	}
821 }
822 EXPORT_SYMBOL(transport_set_vpd_proto_id);
823 
824 int transport_dump_vpd_assoc(
825 	struct t10_vpd *vpd,
826 	unsigned char *p_buf,
827 	int p_buf_len)
828 {
829 	unsigned char buf[VPD_TMP_BUF_SIZE];
830 	int ret = 0;
831 	int len;
832 
833 	memset(buf, 0, VPD_TMP_BUF_SIZE);
834 	len = sprintf(buf, "T10 VPD Identifier Association: ");
835 
836 	switch (vpd->association) {
837 	case 0x00:
838 		sprintf(buf+len, "addressed logical unit\n");
839 		break;
840 	case 0x10:
841 		sprintf(buf+len, "target port\n");
842 		break;
843 	case 0x20:
844 		sprintf(buf+len, "SCSI target device\n");
845 		break;
846 	default:
847 		sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
848 		ret = -EINVAL;
849 		break;
850 	}
851 
852 	if (p_buf)
853 		strncpy(p_buf, buf, p_buf_len);
854 	else
855 		pr_debug("%s", buf);
856 
857 	return ret;
858 }
859 
860 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
861 {
862 	/*
863 	 * The VPD identification association..
864 	 *
865 	 * from spc3r23.pdf Section 7.6.3.1 Table 297
866 	 */
867 	vpd->association = (page_83[1] & 0x30);
868 	return transport_dump_vpd_assoc(vpd, NULL, 0);
869 }
870 EXPORT_SYMBOL(transport_set_vpd_assoc);
871 
872 int transport_dump_vpd_ident_type(
873 	struct t10_vpd *vpd,
874 	unsigned char *p_buf,
875 	int p_buf_len)
876 {
877 	unsigned char buf[VPD_TMP_BUF_SIZE];
878 	int ret = 0;
879 	int len;
880 
881 	memset(buf, 0, VPD_TMP_BUF_SIZE);
882 	len = sprintf(buf, "T10 VPD Identifier Type: ");
883 
884 	switch (vpd->device_identifier_type) {
885 	case 0x00:
886 		sprintf(buf+len, "Vendor specific\n");
887 		break;
888 	case 0x01:
889 		sprintf(buf+len, "T10 Vendor ID based\n");
890 		break;
891 	case 0x02:
892 		sprintf(buf+len, "EUI-64 based\n");
893 		break;
894 	case 0x03:
895 		sprintf(buf+len, "NAA\n");
896 		break;
897 	case 0x04:
898 		sprintf(buf+len, "Relative target port identifier\n");
899 		break;
900 	case 0x08:
901 		sprintf(buf+len, "SCSI name string\n");
902 		break;
903 	default:
904 		sprintf(buf+len, "Unsupported: 0x%02x\n",
905 				vpd->device_identifier_type);
906 		ret = -EINVAL;
907 		break;
908 	}
909 
910 	if (p_buf) {
911 		if (p_buf_len < strlen(buf)+1)
912 			return -EINVAL;
913 		strncpy(p_buf, buf, p_buf_len);
914 	} else {
915 		pr_debug("%s", buf);
916 	}
917 
918 	return ret;
919 }
920 
921 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
922 {
923 	/*
924 	 * The VPD identifier type..
925 	 *
926 	 * from spc3r23.pdf Section 7.6.3.1 Table 298
927 	 */
928 	vpd->device_identifier_type = (page_83[1] & 0x0f);
929 	return transport_dump_vpd_ident_type(vpd, NULL, 0);
930 }
931 EXPORT_SYMBOL(transport_set_vpd_ident_type);
932 
933 int transport_dump_vpd_ident(
934 	struct t10_vpd *vpd,
935 	unsigned char *p_buf,
936 	int p_buf_len)
937 {
938 	unsigned char buf[VPD_TMP_BUF_SIZE];
939 	int ret = 0;
940 
941 	memset(buf, 0, VPD_TMP_BUF_SIZE);
942 
943 	switch (vpd->device_identifier_code_set) {
944 	case 0x01: /* Binary */
945 		snprintf(buf, sizeof(buf),
946 			"T10 VPD Binary Device Identifier: %s\n",
947 			&vpd->device_identifier[0]);
948 		break;
949 	case 0x02: /* ASCII */
950 		snprintf(buf, sizeof(buf),
951 			"T10 VPD ASCII Device Identifier: %s\n",
952 			&vpd->device_identifier[0]);
953 		break;
954 	case 0x03: /* UTF-8 */
955 		snprintf(buf, sizeof(buf),
956 			"T10 VPD UTF-8 Device Identifier: %s\n",
957 			&vpd->device_identifier[0]);
958 		break;
959 	default:
960 		sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
961 			" 0x%02x", vpd->device_identifier_code_set);
962 		ret = -EINVAL;
963 		break;
964 	}
965 
966 	if (p_buf)
967 		strncpy(p_buf, buf, p_buf_len);
968 	else
969 		pr_debug("%s", buf);
970 
971 	return ret;
972 }
973 
974 int
975 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
976 {
977 	static const char hex_str[] = "0123456789abcdef";
978 	int j = 0, i = 4; /* offset to start of the identifier */
979 
980 	/*
981 	 * The VPD Code Set (encoding)
982 	 *
983 	 * from spc3r23.pdf Section 7.6.3.1 Table 296
984 	 */
985 	vpd->device_identifier_code_set = (page_83[0] & 0x0f);
986 	switch (vpd->device_identifier_code_set) {
987 	case 0x01: /* Binary */
988 		vpd->device_identifier[j++] =
989 				hex_str[vpd->device_identifier_type];
990 		while (i < (4 + page_83[3])) {
991 			vpd->device_identifier[j++] =
992 				hex_str[(page_83[i] & 0xf0) >> 4];
993 			vpd->device_identifier[j++] =
994 				hex_str[page_83[i] & 0x0f];
995 			i++;
996 		}
997 		break;
998 	case 0x02: /* ASCII */
999 	case 0x03: /* UTF-8 */
1000 		while (i < (4 + page_83[3]))
1001 			vpd->device_identifier[j++] = page_83[i++];
1002 		break;
1003 	default:
1004 		break;
1005 	}
1006 
1007 	return transport_dump_vpd_ident(vpd, NULL, 0);
1008 }
1009 EXPORT_SYMBOL(transport_set_vpd_ident);
1010 
1011 sense_reason_t
1012 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1013 {
1014 	struct se_device *dev = cmd->se_dev;
1015 
1016 	if (cmd->unknown_data_length) {
1017 		cmd->data_length = size;
1018 	} else if (size != cmd->data_length) {
1019 		pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1020 			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
1021 			" 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1022 				cmd->data_length, size, cmd->t_task_cdb[0]);
1023 
1024 		if (cmd->data_direction == DMA_TO_DEVICE) {
1025 			pr_err("Rejecting underflow/overflow"
1026 					" WRITE data\n");
1027 			return TCM_INVALID_CDB_FIELD;
1028 		}
1029 		/*
1030 		 * Reject READ_* or WRITE_* with overflow/underflow for
1031 		 * type SCF_SCSI_DATA_CDB.
1032 		 */
1033 		if (dev->dev_attrib.block_size != 512)  {
1034 			pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1035 				" CDB on non 512-byte sector setup subsystem"
1036 				" plugin: %s\n", dev->transport->name);
1037 			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1038 			return TCM_INVALID_CDB_FIELD;
1039 		}
1040 		/*
1041 		 * For the overflow case keep the existing fabric provided
1042 		 * ->data_length.  Otherwise for the underflow case, reset
1043 		 * ->data_length to the smaller SCSI expected data transfer
1044 		 * length.
1045 		 */
1046 		if (size > cmd->data_length) {
1047 			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1048 			cmd->residual_count = (size - cmd->data_length);
1049 		} else {
1050 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1051 			cmd->residual_count = (cmd->data_length - size);
1052 			cmd->data_length = size;
1053 		}
1054 	}
1055 
1056 	return 0;
1057 
1058 }
1059 
1060 /*
1061  * Used by fabric modules containing a local struct se_cmd within their
1062  * fabric dependent per I/O descriptor.
1063  */
1064 void transport_init_se_cmd(
1065 	struct se_cmd *cmd,
1066 	struct target_core_fabric_ops *tfo,
1067 	struct se_session *se_sess,
1068 	u32 data_length,
1069 	int data_direction,
1070 	int task_attr,
1071 	unsigned char *sense_buffer)
1072 {
1073 	INIT_LIST_HEAD(&cmd->se_delayed_node);
1074 	INIT_LIST_HEAD(&cmd->se_qf_node);
1075 	INIT_LIST_HEAD(&cmd->se_cmd_list);
1076 	INIT_LIST_HEAD(&cmd->state_list);
1077 	init_completion(&cmd->t_transport_stop_comp);
1078 	init_completion(&cmd->cmd_wait_comp);
1079 	init_completion(&cmd->task_stop_comp);
1080 	spin_lock_init(&cmd->t_state_lock);
1081 	cmd->transport_state = CMD_T_DEV_ACTIVE;
1082 
1083 	cmd->se_tfo = tfo;
1084 	cmd->se_sess = se_sess;
1085 	cmd->data_length = data_length;
1086 	cmd->data_direction = data_direction;
1087 	cmd->sam_task_attr = task_attr;
1088 	cmd->sense_buffer = sense_buffer;
1089 
1090 	cmd->state_active = false;
1091 }
1092 EXPORT_SYMBOL(transport_init_se_cmd);
1093 
1094 static sense_reason_t
1095 transport_check_alloc_task_attr(struct se_cmd *cmd)
1096 {
1097 	struct se_device *dev = cmd->se_dev;
1098 
1099 	/*
1100 	 * Check if SAM Task Attribute emulation is enabled for this
1101 	 * struct se_device storage object
1102 	 */
1103 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1104 		return 0;
1105 
1106 	if (cmd->sam_task_attr == MSG_ACA_TAG) {
1107 		pr_debug("SAM Task Attribute ACA"
1108 			" emulation is not supported\n");
1109 		return TCM_INVALID_CDB_FIELD;
1110 	}
1111 	/*
1112 	 * Used to determine when ORDERED commands should go from
1113 	 * Dormant to Active status.
1114 	 */
1115 	cmd->se_ordered_id = atomic_inc_return(&dev->dev_ordered_id);
1116 	smp_mb__after_atomic_inc();
1117 	pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
1118 			cmd->se_ordered_id, cmd->sam_task_attr,
1119 			dev->transport->name);
1120 	return 0;
1121 }
1122 
1123 sense_reason_t
1124 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1125 {
1126 	struct se_device *dev = cmd->se_dev;
1127 	sense_reason_t ret;
1128 
1129 	/*
1130 	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1131 	 * for VARIABLE_LENGTH_CMD
1132 	 */
1133 	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1134 		pr_err("Received SCSI CDB with command_size: %d that"
1135 			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1136 			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1137 		return TCM_INVALID_CDB_FIELD;
1138 	}
1139 	/*
1140 	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1141 	 * allocate the additional extended CDB buffer now..  Otherwise
1142 	 * setup the pointer from __t_task_cdb to t_task_cdb.
1143 	 */
1144 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1145 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1146 						GFP_KERNEL);
1147 		if (!cmd->t_task_cdb) {
1148 			pr_err("Unable to allocate cmd->t_task_cdb"
1149 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1150 				scsi_command_size(cdb),
1151 				(unsigned long)sizeof(cmd->__t_task_cdb));
1152 			return TCM_OUT_OF_RESOURCES;
1153 		}
1154 	} else
1155 		cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1156 	/*
1157 	 * Copy the original CDB into cmd->
1158 	 */
1159 	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1160 
1161 	trace_target_sequencer_start(cmd);
1162 
1163 	/*
1164 	 * Check for an existing UNIT ATTENTION condition
1165 	 */
1166 	ret = target_scsi3_ua_check(cmd);
1167 	if (ret)
1168 		return ret;
1169 
1170 	ret = target_alua_state_check(cmd);
1171 	if (ret)
1172 		return ret;
1173 
1174 	ret = target_check_reservation(cmd);
1175 	if (ret) {
1176 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1177 		return ret;
1178 	}
1179 
1180 	ret = dev->transport->parse_cdb(cmd);
1181 	if (ret)
1182 		return ret;
1183 
1184 	ret = transport_check_alloc_task_attr(cmd);
1185 	if (ret)
1186 		return ret;
1187 
1188 	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1189 
1190 	spin_lock(&cmd->se_lun->lun_sep_lock);
1191 	if (cmd->se_lun->lun_sep)
1192 		cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
1193 	spin_unlock(&cmd->se_lun->lun_sep_lock);
1194 	return 0;
1195 }
1196 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1197 
1198 /*
1199  * Used by fabric module frontends to queue tasks directly.
1200  * Many only be used from process context only
1201  */
1202 int transport_handle_cdb_direct(
1203 	struct se_cmd *cmd)
1204 {
1205 	sense_reason_t ret;
1206 
1207 	if (!cmd->se_lun) {
1208 		dump_stack();
1209 		pr_err("cmd->se_lun is NULL\n");
1210 		return -EINVAL;
1211 	}
1212 	if (in_interrupt()) {
1213 		dump_stack();
1214 		pr_err("transport_generic_handle_cdb cannot be called"
1215 				" from interrupt context\n");
1216 		return -EINVAL;
1217 	}
1218 	/*
1219 	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1220 	 * outstanding descriptors are handled correctly during shutdown via
1221 	 * transport_wait_for_tasks()
1222 	 *
1223 	 * Also, we don't take cmd->t_state_lock here as we only expect
1224 	 * this to be called for initial descriptor submission.
1225 	 */
1226 	cmd->t_state = TRANSPORT_NEW_CMD;
1227 	cmd->transport_state |= CMD_T_ACTIVE;
1228 
1229 	/*
1230 	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1231 	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1232 	 * and call transport_generic_request_failure() if necessary..
1233 	 */
1234 	ret = transport_generic_new_cmd(cmd);
1235 	if (ret)
1236 		transport_generic_request_failure(cmd, ret);
1237 	return 0;
1238 }
1239 EXPORT_SYMBOL(transport_handle_cdb_direct);
1240 
1241 sense_reason_t
1242 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1243 		u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1244 {
1245 	if (!sgl || !sgl_count)
1246 		return 0;
1247 
1248 	/*
1249 	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1250 	 * scatterlists already have been set to follow what the fabric
1251 	 * passes for the original expected data transfer length.
1252 	 */
1253 	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1254 		pr_warn("Rejecting SCSI DATA overflow for fabric using"
1255 			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1256 		return TCM_INVALID_CDB_FIELD;
1257 	}
1258 
1259 	cmd->t_data_sg = sgl;
1260 	cmd->t_data_nents = sgl_count;
1261 
1262 	if (sgl_bidi && sgl_bidi_count) {
1263 		cmd->t_bidi_data_sg = sgl_bidi;
1264 		cmd->t_bidi_data_nents = sgl_bidi_count;
1265 	}
1266 	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1267 	return 0;
1268 }
1269 
1270 /*
1271  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1272  * 			 se_cmd + use pre-allocated SGL memory.
1273  *
1274  * @se_cmd: command descriptor to submit
1275  * @se_sess: associated se_sess for endpoint
1276  * @cdb: pointer to SCSI CDB
1277  * @sense: pointer to SCSI sense buffer
1278  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1279  * @data_length: fabric expected data transfer length
1280  * @task_addr: SAM task attribute
1281  * @data_dir: DMA data direction
1282  * @flags: flags for command submission from target_sc_flags_tables
1283  * @sgl: struct scatterlist memory for unidirectional mapping
1284  * @sgl_count: scatterlist count for unidirectional mapping
1285  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1286  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1287  *
1288  * Returns non zero to signal active I/O shutdown failure.  All other
1289  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1290  * but still return zero here.
1291  *
1292  * This may only be called from process context, and also currently
1293  * assumes internal allocation of fabric payload buffer by target-core.
1294  */
1295 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1296 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1297 		u32 data_length, int task_attr, int data_dir, int flags,
1298 		struct scatterlist *sgl, u32 sgl_count,
1299 		struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1300 {
1301 	struct se_portal_group *se_tpg;
1302 	sense_reason_t rc;
1303 	int ret;
1304 
1305 	se_tpg = se_sess->se_tpg;
1306 	BUG_ON(!se_tpg);
1307 	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1308 	BUG_ON(in_interrupt());
1309 	/*
1310 	 * Initialize se_cmd for target operation.  From this point
1311 	 * exceptions are handled by sending exception status via
1312 	 * target_core_fabric_ops->queue_status() callback
1313 	 */
1314 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1315 				data_length, data_dir, task_attr, sense);
1316 	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1317 		se_cmd->unknown_data_length = 1;
1318 	/*
1319 	 * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1320 	 * se_sess->sess_cmd_list.  A second kref_get here is necessary
1321 	 * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1322 	 * kref_put() to happen during fabric packet acknowledgement.
1323 	 */
1324 	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1325 	if (ret)
1326 		return ret;
1327 	/*
1328 	 * Signal bidirectional data payloads to target-core
1329 	 */
1330 	if (flags & TARGET_SCF_BIDI_OP)
1331 		se_cmd->se_cmd_flags |= SCF_BIDI;
1332 	/*
1333 	 * Locate se_lun pointer and attach it to struct se_cmd
1334 	 */
1335 	rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1336 	if (rc) {
1337 		transport_send_check_condition_and_sense(se_cmd, rc, 0);
1338 		target_put_sess_cmd(se_sess, se_cmd);
1339 		return 0;
1340 	}
1341 
1342 	rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1343 	if (rc != 0) {
1344 		transport_generic_request_failure(se_cmd, rc);
1345 		return 0;
1346 	}
1347 	/*
1348 	 * When a non zero sgl_count has been passed perform SGL passthrough
1349 	 * mapping for pre-allocated fabric memory instead of having target
1350 	 * core perform an internal SGL allocation..
1351 	 */
1352 	if (sgl_count != 0) {
1353 		BUG_ON(!sgl);
1354 
1355 		/*
1356 		 * A work-around for tcm_loop as some userspace code via
1357 		 * scsi-generic do not memset their associated read buffers,
1358 		 * so go ahead and do that here for type non-data CDBs.  Also
1359 		 * note that this is currently guaranteed to be a single SGL
1360 		 * for this case by target core in target_setup_cmd_from_cdb()
1361 		 * -> transport_generic_cmd_sequencer().
1362 		 */
1363 		if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1364 		     se_cmd->data_direction == DMA_FROM_DEVICE) {
1365 			unsigned char *buf = NULL;
1366 
1367 			if (sgl)
1368 				buf = kmap(sg_page(sgl)) + sgl->offset;
1369 
1370 			if (buf) {
1371 				memset(buf, 0, sgl->length);
1372 				kunmap(sg_page(sgl));
1373 			}
1374 		}
1375 
1376 		rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1377 				sgl_bidi, sgl_bidi_count);
1378 		if (rc != 0) {
1379 			transport_generic_request_failure(se_cmd, rc);
1380 			return 0;
1381 		}
1382 	}
1383 	/*
1384 	 * Check if we need to delay processing because of ALUA
1385 	 * Active/NonOptimized primary access state..
1386 	 */
1387 	core_alua_check_nonop_delay(se_cmd);
1388 
1389 	transport_handle_cdb_direct(se_cmd);
1390 	return 0;
1391 }
1392 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1393 
1394 /*
1395  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1396  *
1397  * @se_cmd: command descriptor to submit
1398  * @se_sess: associated se_sess for endpoint
1399  * @cdb: pointer to SCSI CDB
1400  * @sense: pointer to SCSI sense buffer
1401  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1402  * @data_length: fabric expected data transfer length
1403  * @task_addr: SAM task attribute
1404  * @data_dir: DMA data direction
1405  * @flags: flags for command submission from target_sc_flags_tables
1406  *
1407  * Returns non zero to signal active I/O shutdown failure.  All other
1408  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1409  * but still return zero here.
1410  *
1411  * This may only be called from process context, and also currently
1412  * assumes internal allocation of fabric payload buffer by target-core.
1413  *
1414  * It also assumes interal target core SGL memory allocation.
1415  */
1416 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1417 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1418 		u32 data_length, int task_attr, int data_dir, int flags)
1419 {
1420 	return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1421 			unpacked_lun, data_length, task_attr, data_dir,
1422 			flags, NULL, 0, NULL, 0);
1423 }
1424 EXPORT_SYMBOL(target_submit_cmd);
1425 
1426 static void target_complete_tmr_failure(struct work_struct *work)
1427 {
1428 	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1429 
1430 	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1431 	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1432 
1433 	transport_cmd_check_stop_to_fabric(se_cmd);
1434 }
1435 
1436 /**
1437  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1438  *                     for TMR CDBs
1439  *
1440  * @se_cmd: command descriptor to submit
1441  * @se_sess: associated se_sess for endpoint
1442  * @sense: pointer to SCSI sense buffer
1443  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1444  * @fabric_context: fabric context for TMR req
1445  * @tm_type: Type of TM request
1446  * @gfp: gfp type for caller
1447  * @tag: referenced task tag for TMR_ABORT_TASK
1448  * @flags: submit cmd flags
1449  *
1450  * Callable from all contexts.
1451  **/
1452 
1453 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1454 		unsigned char *sense, u32 unpacked_lun,
1455 		void *fabric_tmr_ptr, unsigned char tm_type,
1456 		gfp_t gfp, unsigned int tag, int flags)
1457 {
1458 	struct se_portal_group *se_tpg;
1459 	int ret;
1460 
1461 	se_tpg = se_sess->se_tpg;
1462 	BUG_ON(!se_tpg);
1463 
1464 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1465 			      0, DMA_NONE, MSG_SIMPLE_TAG, sense);
1466 	/*
1467 	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1468 	 * allocation failure.
1469 	 */
1470 	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1471 	if (ret < 0)
1472 		return -ENOMEM;
1473 
1474 	if (tm_type == TMR_ABORT_TASK)
1475 		se_cmd->se_tmr_req->ref_task_tag = tag;
1476 
1477 	/* See target_submit_cmd for commentary */
1478 	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1479 	if (ret) {
1480 		core_tmr_release_req(se_cmd->se_tmr_req);
1481 		return ret;
1482 	}
1483 
1484 	ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1485 	if (ret) {
1486 		/*
1487 		 * For callback during failure handling, push this work off
1488 		 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1489 		 */
1490 		INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1491 		schedule_work(&se_cmd->work);
1492 		return 0;
1493 	}
1494 	transport_generic_handle_tmr(se_cmd);
1495 	return 0;
1496 }
1497 EXPORT_SYMBOL(target_submit_tmr);
1498 
1499 /*
1500  * If the cmd is active, request it to be stopped and sleep until it
1501  * has completed.
1502  */
1503 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1504 {
1505 	bool was_active = false;
1506 
1507 	if (cmd->transport_state & CMD_T_BUSY) {
1508 		cmd->transport_state |= CMD_T_REQUEST_STOP;
1509 		spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1510 
1511 		pr_debug("cmd %p waiting to complete\n", cmd);
1512 		wait_for_completion(&cmd->task_stop_comp);
1513 		pr_debug("cmd %p stopped successfully\n", cmd);
1514 
1515 		spin_lock_irqsave(&cmd->t_state_lock, *flags);
1516 		cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1517 		cmd->transport_state &= ~CMD_T_BUSY;
1518 		was_active = true;
1519 	}
1520 
1521 	return was_active;
1522 }
1523 
1524 /*
1525  * Handle SAM-esque emulation for generic transport request failures.
1526  */
1527 void transport_generic_request_failure(struct se_cmd *cmd,
1528 		sense_reason_t sense_reason)
1529 {
1530 	int ret = 0;
1531 
1532 	pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
1533 		" CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
1534 		cmd->t_task_cdb[0]);
1535 	pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1536 		cmd->se_tfo->get_cmd_state(cmd),
1537 		cmd->t_state, sense_reason);
1538 	pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1539 		(cmd->transport_state & CMD_T_ACTIVE) != 0,
1540 		(cmd->transport_state & CMD_T_STOP) != 0,
1541 		(cmd->transport_state & CMD_T_SENT) != 0);
1542 
1543 	/*
1544 	 * For SAM Task Attribute emulation for failed struct se_cmd
1545 	 */
1546 	transport_complete_task_attr(cmd);
1547 	/*
1548 	 * Handle special case for COMPARE_AND_WRITE failure, where the
1549 	 * callback is expected to drop the per device ->caw_mutex.
1550 	 */
1551 	if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1552 	     cmd->transport_complete_callback)
1553 		cmd->transport_complete_callback(cmd);
1554 
1555 	switch (sense_reason) {
1556 	case TCM_NON_EXISTENT_LUN:
1557 	case TCM_UNSUPPORTED_SCSI_OPCODE:
1558 	case TCM_INVALID_CDB_FIELD:
1559 	case TCM_INVALID_PARAMETER_LIST:
1560 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
1561 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1562 	case TCM_UNKNOWN_MODE_PAGE:
1563 	case TCM_WRITE_PROTECTED:
1564 	case TCM_ADDRESS_OUT_OF_RANGE:
1565 	case TCM_CHECK_CONDITION_ABORT_CMD:
1566 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1567 	case TCM_CHECK_CONDITION_NOT_READY:
1568 		break;
1569 	case TCM_OUT_OF_RESOURCES:
1570 		sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1571 		break;
1572 	case TCM_RESERVATION_CONFLICT:
1573 		/*
1574 		 * No SENSE Data payload for this case, set SCSI Status
1575 		 * and queue the response to $FABRIC_MOD.
1576 		 *
1577 		 * Uses linux/include/scsi/scsi.h SAM status codes defs
1578 		 */
1579 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1580 		/*
1581 		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1582 		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1583 		 * CONFLICT STATUS.
1584 		 *
1585 		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1586 		 */
1587 		if (cmd->se_sess &&
1588 		    cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2)
1589 			core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
1590 				cmd->orig_fe_lun, 0x2C,
1591 				ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1592 
1593 		trace_target_cmd_complete(cmd);
1594 		ret = cmd->se_tfo-> queue_status(cmd);
1595 		if (ret == -EAGAIN || ret == -ENOMEM)
1596 			goto queue_full;
1597 		goto check_stop;
1598 	default:
1599 		pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1600 			cmd->t_task_cdb[0], sense_reason);
1601 		sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1602 		break;
1603 	}
1604 
1605 	ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1606 	if (ret == -EAGAIN || ret == -ENOMEM)
1607 		goto queue_full;
1608 
1609 check_stop:
1610 	transport_lun_remove_cmd(cmd);
1611 	if (!transport_cmd_check_stop_to_fabric(cmd))
1612 		;
1613 	return;
1614 
1615 queue_full:
1616 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1617 	transport_handle_queue_full(cmd, cmd->se_dev);
1618 }
1619 EXPORT_SYMBOL(transport_generic_request_failure);
1620 
1621 void __target_execute_cmd(struct se_cmd *cmd)
1622 {
1623 	sense_reason_t ret;
1624 
1625 	if (cmd->execute_cmd) {
1626 		ret = cmd->execute_cmd(cmd);
1627 		if (ret) {
1628 			spin_lock_irq(&cmd->t_state_lock);
1629 			cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1630 			spin_unlock_irq(&cmd->t_state_lock);
1631 
1632 			transport_generic_request_failure(cmd, ret);
1633 		}
1634 	}
1635 }
1636 
1637 static bool target_handle_task_attr(struct se_cmd *cmd)
1638 {
1639 	struct se_device *dev = cmd->se_dev;
1640 
1641 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1642 		return false;
1643 
1644 	/*
1645 	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1646 	 * to allow the passed struct se_cmd list of tasks to the front of the list.
1647 	 */
1648 	switch (cmd->sam_task_attr) {
1649 	case MSG_HEAD_TAG:
1650 		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
1651 			 "se_ordered_id: %u\n",
1652 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1653 		return false;
1654 	case MSG_ORDERED_TAG:
1655 		atomic_inc(&dev->dev_ordered_sync);
1656 		smp_mb__after_atomic_inc();
1657 
1658 		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
1659 			 " se_ordered_id: %u\n",
1660 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1661 
1662 		/*
1663 		 * Execute an ORDERED command if no other older commands
1664 		 * exist that need to be completed first.
1665 		 */
1666 		if (!atomic_read(&dev->simple_cmds))
1667 			return false;
1668 		break;
1669 	default:
1670 		/*
1671 		 * For SIMPLE and UNTAGGED Task Attribute commands
1672 		 */
1673 		atomic_inc(&dev->simple_cmds);
1674 		smp_mb__after_atomic_inc();
1675 		break;
1676 	}
1677 
1678 	if (atomic_read(&dev->dev_ordered_sync) == 0)
1679 		return false;
1680 
1681 	spin_lock(&dev->delayed_cmd_lock);
1682 	list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1683 	spin_unlock(&dev->delayed_cmd_lock);
1684 
1685 	pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
1686 		" delayed CMD list, se_ordered_id: %u\n",
1687 		cmd->t_task_cdb[0], cmd->sam_task_attr,
1688 		cmd->se_ordered_id);
1689 	return true;
1690 }
1691 
1692 void target_execute_cmd(struct se_cmd *cmd)
1693 {
1694 	/*
1695 	 * If the received CDB has aleady been aborted stop processing it here.
1696 	 */
1697 	if (transport_check_aborted_status(cmd, 1))
1698 		return;
1699 
1700 	/*
1701 	 * Determine if frontend context caller is requesting the stopping of
1702 	 * this command for frontend exceptions.
1703 	 */
1704 	spin_lock_irq(&cmd->t_state_lock);
1705 	if (cmd->transport_state & CMD_T_STOP) {
1706 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
1707 			__func__, __LINE__,
1708 			cmd->se_tfo->get_task_tag(cmd));
1709 
1710 		spin_unlock_irq(&cmd->t_state_lock);
1711 		complete(&cmd->t_transport_stop_comp);
1712 		return;
1713 	}
1714 
1715 	cmd->t_state = TRANSPORT_PROCESSING;
1716 	cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1717 	spin_unlock_irq(&cmd->t_state_lock);
1718 
1719 	if (target_handle_task_attr(cmd)) {
1720 		spin_lock_irq(&cmd->t_state_lock);
1721 		cmd->transport_state &= ~CMD_T_BUSY|CMD_T_SENT;
1722 		spin_unlock_irq(&cmd->t_state_lock);
1723 		return;
1724 	}
1725 
1726 	__target_execute_cmd(cmd);
1727 }
1728 EXPORT_SYMBOL(target_execute_cmd);
1729 
1730 /*
1731  * Process all commands up to the last received ORDERED task attribute which
1732  * requires another blocking boundary
1733  */
1734 static void target_restart_delayed_cmds(struct se_device *dev)
1735 {
1736 	for (;;) {
1737 		struct se_cmd *cmd;
1738 
1739 		spin_lock(&dev->delayed_cmd_lock);
1740 		if (list_empty(&dev->delayed_cmd_list)) {
1741 			spin_unlock(&dev->delayed_cmd_lock);
1742 			break;
1743 		}
1744 
1745 		cmd = list_entry(dev->delayed_cmd_list.next,
1746 				 struct se_cmd, se_delayed_node);
1747 		list_del(&cmd->se_delayed_node);
1748 		spin_unlock(&dev->delayed_cmd_lock);
1749 
1750 		__target_execute_cmd(cmd);
1751 
1752 		if (cmd->sam_task_attr == MSG_ORDERED_TAG)
1753 			break;
1754 	}
1755 }
1756 
1757 /*
1758  * Called from I/O completion to determine which dormant/delayed
1759  * and ordered cmds need to have their tasks added to the execution queue.
1760  */
1761 static void transport_complete_task_attr(struct se_cmd *cmd)
1762 {
1763 	struct se_device *dev = cmd->se_dev;
1764 
1765 	if (dev->transport->transport_type == TRANSPORT_PLUGIN_PHBA_PDEV)
1766 		return;
1767 
1768 	if (cmd->sam_task_attr == MSG_SIMPLE_TAG) {
1769 		atomic_dec(&dev->simple_cmds);
1770 		smp_mb__after_atomic_dec();
1771 		dev->dev_cur_ordered_id++;
1772 		pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
1773 			" SIMPLE: %u\n", dev->dev_cur_ordered_id,
1774 			cmd->se_ordered_id);
1775 	} else if (cmd->sam_task_attr == MSG_HEAD_TAG) {
1776 		dev->dev_cur_ordered_id++;
1777 		pr_debug("Incremented dev_cur_ordered_id: %u for"
1778 			" HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
1779 			cmd->se_ordered_id);
1780 	} else if (cmd->sam_task_attr == MSG_ORDERED_TAG) {
1781 		atomic_dec(&dev->dev_ordered_sync);
1782 		smp_mb__after_atomic_dec();
1783 
1784 		dev->dev_cur_ordered_id++;
1785 		pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
1786 			" %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
1787 	}
1788 
1789 	target_restart_delayed_cmds(dev);
1790 }
1791 
1792 static void transport_complete_qf(struct se_cmd *cmd)
1793 {
1794 	int ret = 0;
1795 
1796 	transport_complete_task_attr(cmd);
1797 
1798 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1799 		trace_target_cmd_complete(cmd);
1800 		ret = cmd->se_tfo->queue_status(cmd);
1801 		if (ret)
1802 			goto out;
1803 	}
1804 
1805 	switch (cmd->data_direction) {
1806 	case DMA_FROM_DEVICE:
1807 		trace_target_cmd_complete(cmd);
1808 		ret = cmd->se_tfo->queue_data_in(cmd);
1809 		break;
1810 	case DMA_TO_DEVICE:
1811 		if (cmd->se_cmd_flags & SCF_BIDI) {
1812 			ret = cmd->se_tfo->queue_data_in(cmd);
1813 			if (ret < 0)
1814 				break;
1815 		}
1816 		/* Fall through for DMA_TO_DEVICE */
1817 	case DMA_NONE:
1818 		trace_target_cmd_complete(cmd);
1819 		ret = cmd->se_tfo->queue_status(cmd);
1820 		break;
1821 	default:
1822 		break;
1823 	}
1824 
1825 out:
1826 	if (ret < 0) {
1827 		transport_handle_queue_full(cmd, cmd->se_dev);
1828 		return;
1829 	}
1830 	transport_lun_remove_cmd(cmd);
1831 	transport_cmd_check_stop_to_fabric(cmd);
1832 }
1833 
1834 static void transport_handle_queue_full(
1835 	struct se_cmd *cmd,
1836 	struct se_device *dev)
1837 {
1838 	spin_lock_irq(&dev->qf_cmd_lock);
1839 	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
1840 	atomic_inc(&dev->dev_qf_count);
1841 	smp_mb__after_atomic_inc();
1842 	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
1843 
1844 	schedule_work(&cmd->se_dev->qf_work_queue);
1845 }
1846 
1847 static void target_complete_ok_work(struct work_struct *work)
1848 {
1849 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
1850 	int ret;
1851 
1852 	/*
1853 	 * Check if we need to move delayed/dormant tasks from cmds on the
1854 	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
1855 	 * Attribute.
1856 	 */
1857 	transport_complete_task_attr(cmd);
1858 
1859 	/*
1860 	 * Check to schedule QUEUE_FULL work, or execute an existing
1861 	 * cmd->transport_qf_callback()
1862 	 */
1863 	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
1864 		schedule_work(&cmd->se_dev->qf_work_queue);
1865 
1866 	/*
1867 	 * Check if we need to send a sense buffer from
1868 	 * the struct se_cmd in question.
1869 	 */
1870 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1871 		WARN_ON(!cmd->scsi_status);
1872 		ret = transport_send_check_condition_and_sense(
1873 					cmd, 0, 1);
1874 		if (ret == -EAGAIN || ret == -ENOMEM)
1875 			goto queue_full;
1876 
1877 		transport_lun_remove_cmd(cmd);
1878 		transport_cmd_check_stop_to_fabric(cmd);
1879 		return;
1880 	}
1881 	/*
1882 	 * Check for a callback, used by amongst other things
1883 	 * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
1884 	 */
1885 	if (cmd->transport_complete_callback) {
1886 		sense_reason_t rc;
1887 
1888 		rc = cmd->transport_complete_callback(cmd);
1889 		if (!rc && !(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE_POST)) {
1890 			return;
1891 		} else if (rc) {
1892 			ret = transport_send_check_condition_and_sense(cmd,
1893 						rc, 0);
1894 			if (ret == -EAGAIN || ret == -ENOMEM)
1895 				goto queue_full;
1896 
1897 			transport_lun_remove_cmd(cmd);
1898 			transport_cmd_check_stop_to_fabric(cmd);
1899 			return;
1900 		}
1901 	}
1902 
1903 	switch (cmd->data_direction) {
1904 	case DMA_FROM_DEVICE:
1905 		spin_lock(&cmd->se_lun->lun_sep_lock);
1906 		if (cmd->se_lun->lun_sep) {
1907 			cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
1908 					cmd->data_length;
1909 		}
1910 		spin_unlock(&cmd->se_lun->lun_sep_lock);
1911 
1912 		trace_target_cmd_complete(cmd);
1913 		ret = cmd->se_tfo->queue_data_in(cmd);
1914 		if (ret == -EAGAIN || ret == -ENOMEM)
1915 			goto queue_full;
1916 		break;
1917 	case DMA_TO_DEVICE:
1918 		spin_lock(&cmd->se_lun->lun_sep_lock);
1919 		if (cmd->se_lun->lun_sep) {
1920 			cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
1921 				cmd->data_length;
1922 		}
1923 		spin_unlock(&cmd->se_lun->lun_sep_lock);
1924 		/*
1925 		 * Check if we need to send READ payload for BIDI-COMMAND
1926 		 */
1927 		if (cmd->se_cmd_flags & SCF_BIDI) {
1928 			spin_lock(&cmd->se_lun->lun_sep_lock);
1929 			if (cmd->se_lun->lun_sep) {
1930 				cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
1931 					cmd->data_length;
1932 			}
1933 			spin_unlock(&cmd->se_lun->lun_sep_lock);
1934 			ret = cmd->se_tfo->queue_data_in(cmd);
1935 			if (ret == -EAGAIN || ret == -ENOMEM)
1936 				goto queue_full;
1937 			break;
1938 		}
1939 		/* Fall through for DMA_TO_DEVICE */
1940 	case DMA_NONE:
1941 		trace_target_cmd_complete(cmd);
1942 		ret = cmd->se_tfo->queue_status(cmd);
1943 		if (ret == -EAGAIN || ret == -ENOMEM)
1944 			goto queue_full;
1945 		break;
1946 	default:
1947 		break;
1948 	}
1949 
1950 	transport_lun_remove_cmd(cmd);
1951 	transport_cmd_check_stop_to_fabric(cmd);
1952 	return;
1953 
1954 queue_full:
1955 	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
1956 		" data_direction: %d\n", cmd, cmd->data_direction);
1957 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1958 	transport_handle_queue_full(cmd, cmd->se_dev);
1959 }
1960 
1961 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
1962 {
1963 	struct scatterlist *sg;
1964 	int count;
1965 
1966 	for_each_sg(sgl, sg, nents, count)
1967 		__free_page(sg_page(sg));
1968 
1969 	kfree(sgl);
1970 }
1971 
1972 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
1973 {
1974 	/*
1975 	 * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
1976 	 * emulation, and free + reset pointers if necessary..
1977 	 */
1978 	if (!cmd->t_data_sg_orig)
1979 		return;
1980 
1981 	kfree(cmd->t_data_sg);
1982 	cmd->t_data_sg = cmd->t_data_sg_orig;
1983 	cmd->t_data_sg_orig = NULL;
1984 	cmd->t_data_nents = cmd->t_data_nents_orig;
1985 	cmd->t_data_nents_orig = 0;
1986 }
1987 
1988 static inline void transport_free_pages(struct se_cmd *cmd)
1989 {
1990 	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
1991 		transport_reset_sgl_orig(cmd);
1992 		return;
1993 	}
1994 	transport_reset_sgl_orig(cmd);
1995 
1996 	transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
1997 	cmd->t_data_sg = NULL;
1998 	cmd->t_data_nents = 0;
1999 
2000 	transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2001 	cmd->t_bidi_data_sg = NULL;
2002 	cmd->t_bidi_data_nents = 0;
2003 }
2004 
2005 /**
2006  * transport_release_cmd - free a command
2007  * @cmd:       command to free
2008  *
2009  * This routine unconditionally frees a command, and reference counting
2010  * or list removal must be done in the caller.
2011  */
2012 static int transport_release_cmd(struct se_cmd *cmd)
2013 {
2014 	BUG_ON(!cmd->se_tfo);
2015 
2016 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2017 		core_tmr_release_req(cmd->se_tmr_req);
2018 	if (cmd->t_task_cdb != cmd->__t_task_cdb)
2019 		kfree(cmd->t_task_cdb);
2020 	/*
2021 	 * If this cmd has been setup with target_get_sess_cmd(), drop
2022 	 * the kref and call ->release_cmd() in kref callback.
2023 	 */
2024 	return target_put_sess_cmd(cmd->se_sess, cmd);
2025 }
2026 
2027 /**
2028  * transport_put_cmd - release a reference to a command
2029  * @cmd:       command to release
2030  *
2031  * This routine releases our reference to the command and frees it if possible.
2032  */
2033 static int transport_put_cmd(struct se_cmd *cmd)
2034 {
2035 	transport_free_pages(cmd);
2036 	return transport_release_cmd(cmd);
2037 }
2038 
2039 void *transport_kmap_data_sg(struct se_cmd *cmd)
2040 {
2041 	struct scatterlist *sg = cmd->t_data_sg;
2042 	struct page **pages;
2043 	int i;
2044 
2045 	/*
2046 	 * We need to take into account a possible offset here for fabrics like
2047 	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2048 	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2049 	 */
2050 	if (!cmd->t_data_nents)
2051 		return NULL;
2052 
2053 	BUG_ON(!sg);
2054 	if (cmd->t_data_nents == 1)
2055 		return kmap(sg_page(sg)) + sg->offset;
2056 
2057 	/* >1 page. use vmap */
2058 	pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2059 	if (!pages)
2060 		return NULL;
2061 
2062 	/* convert sg[] to pages[] */
2063 	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2064 		pages[i] = sg_page(sg);
2065 	}
2066 
2067 	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2068 	kfree(pages);
2069 	if (!cmd->t_data_vmap)
2070 		return NULL;
2071 
2072 	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2073 }
2074 EXPORT_SYMBOL(transport_kmap_data_sg);
2075 
2076 void transport_kunmap_data_sg(struct se_cmd *cmd)
2077 {
2078 	if (!cmd->t_data_nents) {
2079 		return;
2080 	} else if (cmd->t_data_nents == 1) {
2081 		kunmap(sg_page(cmd->t_data_sg));
2082 		return;
2083 	}
2084 
2085 	vunmap(cmd->t_data_vmap);
2086 	cmd->t_data_vmap = NULL;
2087 }
2088 EXPORT_SYMBOL(transport_kunmap_data_sg);
2089 
2090 int
2091 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2092 		 bool zero_page)
2093 {
2094 	struct scatterlist *sg;
2095 	struct page *page;
2096 	gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2097 	unsigned int nent;
2098 	int i = 0;
2099 
2100 	nent = DIV_ROUND_UP(length, PAGE_SIZE);
2101 	sg = kmalloc(sizeof(struct scatterlist) * nent, GFP_KERNEL);
2102 	if (!sg)
2103 		return -ENOMEM;
2104 
2105 	sg_init_table(sg, nent);
2106 
2107 	while (length) {
2108 		u32 page_len = min_t(u32, length, PAGE_SIZE);
2109 		page = alloc_page(GFP_KERNEL | zero_flag);
2110 		if (!page)
2111 			goto out;
2112 
2113 		sg_set_page(&sg[i], page, page_len, 0);
2114 		length -= page_len;
2115 		i++;
2116 	}
2117 	*sgl = sg;
2118 	*nents = nent;
2119 	return 0;
2120 
2121 out:
2122 	while (i > 0) {
2123 		i--;
2124 		__free_page(sg_page(&sg[i]));
2125 	}
2126 	kfree(sg);
2127 	return -ENOMEM;
2128 }
2129 
2130 /*
2131  * Allocate any required resources to execute the command.  For writes we
2132  * might not have the payload yet, so notify the fabric via a call to
2133  * ->write_pending instead. Otherwise place it on the execution queue.
2134  */
2135 sense_reason_t
2136 transport_generic_new_cmd(struct se_cmd *cmd)
2137 {
2138 	int ret = 0;
2139 
2140 	/*
2141 	 * Determine is the TCM fabric module has already allocated physical
2142 	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2143 	 * beforehand.
2144 	 */
2145 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2146 	    cmd->data_length) {
2147 		bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2148 
2149 		if ((cmd->se_cmd_flags & SCF_BIDI) ||
2150 		    (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2151 			u32 bidi_length;
2152 
2153 			if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2154 				bidi_length = cmd->t_task_nolb *
2155 					      cmd->se_dev->dev_attrib.block_size;
2156 			else
2157 				bidi_length = cmd->data_length;
2158 
2159 			ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2160 					       &cmd->t_bidi_data_nents,
2161 					       bidi_length, zero_flag);
2162 			if (ret < 0)
2163 				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2164 		}
2165 
2166 		ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2167 				       cmd->data_length, zero_flag);
2168 		if (ret < 0)
2169 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2170 	}
2171 	/*
2172 	 * If this command is not a write we can execute it right here,
2173 	 * for write buffers we need to notify the fabric driver first
2174 	 * and let it call back once the write buffers are ready.
2175 	 */
2176 	target_add_to_state_list(cmd);
2177 	if (cmd->data_direction != DMA_TO_DEVICE) {
2178 		target_execute_cmd(cmd);
2179 		return 0;
2180 	}
2181 	transport_cmd_check_stop(cmd, false, true);
2182 
2183 	ret = cmd->se_tfo->write_pending(cmd);
2184 	if (ret == -EAGAIN || ret == -ENOMEM)
2185 		goto queue_full;
2186 
2187 	/* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2188 	WARN_ON(ret);
2189 
2190 	return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2191 
2192 queue_full:
2193 	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2194 	cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2195 	transport_handle_queue_full(cmd, cmd->se_dev);
2196 	return 0;
2197 }
2198 EXPORT_SYMBOL(transport_generic_new_cmd);
2199 
2200 static void transport_write_pending_qf(struct se_cmd *cmd)
2201 {
2202 	int ret;
2203 
2204 	ret = cmd->se_tfo->write_pending(cmd);
2205 	if (ret == -EAGAIN || ret == -ENOMEM) {
2206 		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2207 			 cmd);
2208 		transport_handle_queue_full(cmd, cmd->se_dev);
2209 	}
2210 }
2211 
2212 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2213 {
2214 	unsigned long flags;
2215 	int ret = 0;
2216 
2217 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2218 		if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2219 			 transport_wait_for_tasks(cmd);
2220 
2221 		ret = transport_release_cmd(cmd);
2222 	} else {
2223 		if (wait_for_tasks)
2224 			transport_wait_for_tasks(cmd);
2225 		/*
2226 		 * Handle WRITE failure case where transport_generic_new_cmd()
2227 		 * has already added se_cmd to state_list, but fabric has
2228 		 * failed command before I/O submission.
2229 		 */
2230 		if (cmd->state_active) {
2231 			spin_lock_irqsave(&cmd->t_state_lock, flags);
2232 			target_remove_from_state_list(cmd);
2233 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2234 		}
2235 
2236 		if (cmd->se_lun)
2237 			transport_lun_remove_cmd(cmd);
2238 
2239 		ret = transport_put_cmd(cmd);
2240 	}
2241 	return ret;
2242 }
2243 EXPORT_SYMBOL(transport_generic_free_cmd);
2244 
2245 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2246  * @se_sess:	session to reference
2247  * @se_cmd:	command descriptor to add
2248  * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
2249  */
2250 int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
2251 			       bool ack_kref)
2252 {
2253 	unsigned long flags;
2254 	int ret = 0;
2255 
2256 	kref_init(&se_cmd->cmd_kref);
2257 	/*
2258 	 * Add a second kref if the fabric caller is expecting to handle
2259 	 * fabric acknowledgement that requires two target_put_sess_cmd()
2260 	 * invocations before se_cmd descriptor release.
2261 	 */
2262 	if (ack_kref == true) {
2263 		kref_get(&se_cmd->cmd_kref);
2264 		se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2265 	}
2266 
2267 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2268 	if (se_sess->sess_tearing_down) {
2269 		ret = -ESHUTDOWN;
2270 		goto out;
2271 	}
2272 	list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2273 out:
2274 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2275 	return ret;
2276 }
2277 EXPORT_SYMBOL(target_get_sess_cmd);
2278 
2279 static void target_release_cmd_kref(struct kref *kref)
2280 {
2281 	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2282 	struct se_session *se_sess = se_cmd->se_sess;
2283 
2284 	if (list_empty(&se_cmd->se_cmd_list)) {
2285 		spin_unlock(&se_sess->sess_cmd_lock);
2286 		se_cmd->se_tfo->release_cmd(se_cmd);
2287 		return;
2288 	}
2289 	if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2290 		spin_unlock(&se_sess->sess_cmd_lock);
2291 		complete(&se_cmd->cmd_wait_comp);
2292 		return;
2293 	}
2294 	list_del(&se_cmd->se_cmd_list);
2295 	spin_unlock(&se_sess->sess_cmd_lock);
2296 
2297 	se_cmd->se_tfo->release_cmd(se_cmd);
2298 }
2299 
2300 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2301  * @se_sess:	session to reference
2302  * @se_cmd:	command descriptor to drop
2303  */
2304 int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd)
2305 {
2306 	return kref_put_spinlock_irqsave(&se_cmd->cmd_kref, target_release_cmd_kref,
2307 			&se_sess->sess_cmd_lock);
2308 }
2309 EXPORT_SYMBOL(target_put_sess_cmd);
2310 
2311 /* target_sess_cmd_list_set_waiting - Flag all commands in
2312  *         sess_cmd_list to complete cmd_wait_comp.  Set
2313  *         sess_tearing_down so no more commands are queued.
2314  * @se_sess:	session to flag
2315  */
2316 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2317 {
2318 	struct se_cmd *se_cmd;
2319 	unsigned long flags;
2320 
2321 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2322 	if (se_sess->sess_tearing_down) {
2323 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2324 		return;
2325 	}
2326 	se_sess->sess_tearing_down = 1;
2327 	list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2328 
2329 	list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list)
2330 		se_cmd->cmd_wait_set = 1;
2331 
2332 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2333 }
2334 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2335 
2336 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2337  * @se_sess:    session to wait for active I/O
2338  */
2339 void target_wait_for_sess_cmds(struct se_session *se_sess)
2340 {
2341 	struct se_cmd *se_cmd, *tmp_cmd;
2342 	unsigned long flags;
2343 
2344 	list_for_each_entry_safe(se_cmd, tmp_cmd,
2345 				&se_sess->sess_wait_list, se_cmd_list) {
2346 		list_del(&se_cmd->se_cmd_list);
2347 
2348 		pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2349 			" %d\n", se_cmd, se_cmd->t_state,
2350 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2351 
2352 		wait_for_completion(&se_cmd->cmd_wait_comp);
2353 		pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2354 			" fabric state: %d\n", se_cmd, se_cmd->t_state,
2355 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2356 
2357 		se_cmd->se_tfo->release_cmd(se_cmd);
2358 	}
2359 
2360 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2361 	WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2362 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2363 
2364 }
2365 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2366 
2367 static int transport_clear_lun_ref_thread(void *p)
2368 {
2369 	struct se_lun *lun = p;
2370 
2371 	percpu_ref_kill(&lun->lun_ref);
2372 
2373 	wait_for_completion(&lun->lun_ref_comp);
2374 	complete(&lun->lun_shutdown_comp);
2375 
2376 	return 0;
2377 }
2378 
2379 int transport_clear_lun_ref(struct se_lun *lun)
2380 {
2381 	struct task_struct *kt;
2382 
2383 	kt = kthread_run(transport_clear_lun_ref_thread, lun,
2384 			"tcm_cl_%u", lun->unpacked_lun);
2385 	if (IS_ERR(kt)) {
2386 		pr_err("Unable to start clear_lun thread\n");
2387 		return PTR_ERR(kt);
2388 	}
2389 	wait_for_completion(&lun->lun_shutdown_comp);
2390 
2391 	return 0;
2392 }
2393 
2394 /**
2395  * transport_wait_for_tasks - wait for completion to occur
2396  * @cmd:	command to wait
2397  *
2398  * Called from frontend fabric context to wait for storage engine
2399  * to pause and/or release frontend generated struct se_cmd.
2400  */
2401 bool transport_wait_for_tasks(struct se_cmd *cmd)
2402 {
2403 	unsigned long flags;
2404 
2405 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2406 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2407 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2408 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2409 		return false;
2410 	}
2411 
2412 	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2413 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2414 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2415 		return false;
2416 	}
2417 
2418 	if (!(cmd->transport_state & CMD_T_ACTIVE)) {
2419 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2420 		return false;
2421 	}
2422 
2423 	cmd->transport_state |= CMD_T_STOP;
2424 
2425 	pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
2426 		" i_state: %d, t_state: %d, CMD_T_STOP\n",
2427 		cmd, cmd->se_tfo->get_task_tag(cmd),
2428 		cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2429 
2430 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2431 
2432 	wait_for_completion(&cmd->t_transport_stop_comp);
2433 
2434 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2435 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2436 
2437 	pr_debug("wait_for_tasks: Stopped wait_for_completion("
2438 		"&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
2439 		cmd->se_tfo->get_task_tag(cmd));
2440 
2441 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2442 
2443 	return true;
2444 }
2445 EXPORT_SYMBOL(transport_wait_for_tasks);
2446 
2447 static int transport_get_sense_codes(
2448 	struct se_cmd *cmd,
2449 	u8 *asc,
2450 	u8 *ascq)
2451 {
2452 	*asc = cmd->scsi_asc;
2453 	*ascq = cmd->scsi_ascq;
2454 
2455 	return 0;
2456 }
2457 
2458 int
2459 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2460 		sense_reason_t reason, int from_transport)
2461 {
2462 	unsigned char *buffer = cmd->sense_buffer;
2463 	unsigned long flags;
2464 	u8 asc = 0, ascq = 0;
2465 
2466 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2467 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2468 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2469 		return 0;
2470 	}
2471 	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2472 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2473 
2474 	if (!reason && from_transport)
2475 		goto after_reason;
2476 
2477 	if (!from_transport)
2478 		cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2479 
2480 	/*
2481 	 * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
2482 	 * SENSE KEY values from include/scsi/scsi.h
2483 	 */
2484 	switch (reason) {
2485 	case TCM_NO_SENSE:
2486 		/* CURRENT ERROR */
2487 		buffer[0] = 0x70;
2488 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2489 		/* Not Ready */
2490 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2491 		/* NO ADDITIONAL SENSE INFORMATION */
2492 		buffer[SPC_ASC_KEY_OFFSET] = 0;
2493 		buffer[SPC_ASCQ_KEY_OFFSET] = 0;
2494 		break;
2495 	case TCM_NON_EXISTENT_LUN:
2496 		/* CURRENT ERROR */
2497 		buffer[0] = 0x70;
2498 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2499 		/* ILLEGAL REQUEST */
2500 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2501 		/* LOGICAL UNIT NOT SUPPORTED */
2502 		buffer[SPC_ASC_KEY_OFFSET] = 0x25;
2503 		break;
2504 	case TCM_UNSUPPORTED_SCSI_OPCODE:
2505 	case TCM_SECTOR_COUNT_TOO_MANY:
2506 		/* CURRENT ERROR */
2507 		buffer[0] = 0x70;
2508 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2509 		/* ILLEGAL REQUEST */
2510 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2511 		/* INVALID COMMAND OPERATION CODE */
2512 		buffer[SPC_ASC_KEY_OFFSET] = 0x20;
2513 		break;
2514 	case TCM_UNKNOWN_MODE_PAGE:
2515 		/* CURRENT ERROR */
2516 		buffer[0] = 0x70;
2517 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2518 		/* ILLEGAL REQUEST */
2519 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2520 		/* INVALID FIELD IN CDB */
2521 		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2522 		break;
2523 	case TCM_CHECK_CONDITION_ABORT_CMD:
2524 		/* CURRENT ERROR */
2525 		buffer[0] = 0x70;
2526 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2527 		/* ABORTED COMMAND */
2528 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2529 		/* BUS DEVICE RESET FUNCTION OCCURRED */
2530 		buffer[SPC_ASC_KEY_OFFSET] = 0x29;
2531 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2532 		break;
2533 	case TCM_INCORRECT_AMOUNT_OF_DATA:
2534 		/* CURRENT ERROR */
2535 		buffer[0] = 0x70;
2536 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2537 		/* ABORTED COMMAND */
2538 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2539 		/* WRITE ERROR */
2540 		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2541 		/* NOT ENOUGH UNSOLICITED DATA */
2542 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0d;
2543 		break;
2544 	case TCM_INVALID_CDB_FIELD:
2545 		/* CURRENT ERROR */
2546 		buffer[0] = 0x70;
2547 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2548 		/* ILLEGAL REQUEST */
2549 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2550 		/* INVALID FIELD IN CDB */
2551 		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2552 		break;
2553 	case TCM_INVALID_PARAMETER_LIST:
2554 		/* CURRENT ERROR */
2555 		buffer[0] = 0x70;
2556 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2557 		/* ILLEGAL REQUEST */
2558 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2559 		/* INVALID FIELD IN PARAMETER LIST */
2560 		buffer[SPC_ASC_KEY_OFFSET] = 0x26;
2561 		break;
2562 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
2563 		/* CURRENT ERROR */
2564 		buffer[0] = 0x70;
2565 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2566 		/* ILLEGAL REQUEST */
2567 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2568 		/* PARAMETER LIST LENGTH ERROR */
2569 		buffer[SPC_ASC_KEY_OFFSET] = 0x1a;
2570 		break;
2571 	case TCM_UNEXPECTED_UNSOLICITED_DATA:
2572 		/* CURRENT ERROR */
2573 		buffer[0] = 0x70;
2574 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2575 		/* ABORTED COMMAND */
2576 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2577 		/* WRITE ERROR */
2578 		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2579 		/* UNEXPECTED_UNSOLICITED_DATA */
2580 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0c;
2581 		break;
2582 	case TCM_SERVICE_CRC_ERROR:
2583 		/* CURRENT ERROR */
2584 		buffer[0] = 0x70;
2585 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2586 		/* ABORTED COMMAND */
2587 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2588 		/* PROTOCOL SERVICE CRC ERROR */
2589 		buffer[SPC_ASC_KEY_OFFSET] = 0x47;
2590 		/* N/A */
2591 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x05;
2592 		break;
2593 	case TCM_SNACK_REJECTED:
2594 		/* CURRENT ERROR */
2595 		buffer[0] = 0x70;
2596 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2597 		/* ABORTED COMMAND */
2598 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2599 		/* READ ERROR */
2600 		buffer[SPC_ASC_KEY_OFFSET] = 0x11;
2601 		/* FAILED RETRANSMISSION REQUEST */
2602 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x13;
2603 		break;
2604 	case TCM_WRITE_PROTECTED:
2605 		/* CURRENT ERROR */
2606 		buffer[0] = 0x70;
2607 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2608 		/* DATA PROTECT */
2609 		buffer[SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
2610 		/* WRITE PROTECTED */
2611 		buffer[SPC_ASC_KEY_OFFSET] = 0x27;
2612 		break;
2613 	case TCM_ADDRESS_OUT_OF_RANGE:
2614 		/* CURRENT ERROR */
2615 		buffer[0] = 0x70;
2616 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2617 		/* ILLEGAL REQUEST */
2618 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2619 		/* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2620 		buffer[SPC_ASC_KEY_OFFSET] = 0x21;
2621 		break;
2622 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2623 		/* CURRENT ERROR */
2624 		buffer[0] = 0x70;
2625 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2626 		/* UNIT ATTENTION */
2627 		buffer[SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
2628 		core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2629 		buffer[SPC_ASC_KEY_OFFSET] = asc;
2630 		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2631 		break;
2632 	case TCM_CHECK_CONDITION_NOT_READY:
2633 		/* CURRENT ERROR */
2634 		buffer[0] = 0x70;
2635 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2636 		/* Not Ready */
2637 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2638 		transport_get_sense_codes(cmd, &asc, &ascq);
2639 		buffer[SPC_ASC_KEY_OFFSET] = asc;
2640 		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2641 		break;
2642 	case TCM_MISCOMPARE_VERIFY:
2643 		/* CURRENT ERROR */
2644 		buffer[0] = 0x70;
2645 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2646 		buffer[SPC_SENSE_KEY_OFFSET] = MISCOMPARE;
2647 		/* MISCOMPARE DURING VERIFY OPERATION */
2648 		buffer[SPC_ASC_KEY_OFFSET] = 0x1d;
2649 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x00;
2650 		break;
2651 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
2652 	default:
2653 		/* CURRENT ERROR */
2654 		buffer[0] = 0x70;
2655 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2656 		/*
2657 		 * Returning ILLEGAL REQUEST would cause immediate IO errors on
2658 		 * Solaris initiators.  Returning NOT READY instead means the
2659 		 * operations will be retried a finite number of times and we
2660 		 * can survive intermittent errors.
2661 		 */
2662 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2663 		/* LOGICAL UNIT COMMUNICATION FAILURE */
2664 		buffer[SPC_ASC_KEY_OFFSET] = 0x08;
2665 		break;
2666 	}
2667 	/*
2668 	 * This code uses linux/include/scsi/scsi.h SAM status codes!
2669 	 */
2670 	cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2671 	/*
2672 	 * Automatically padded, this value is encoded in the fabric's
2673 	 * data_length response PDU containing the SCSI defined sense data.
2674 	 */
2675 	cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2676 
2677 after_reason:
2678 	trace_target_cmd_complete(cmd);
2679 	return cmd->se_tfo->queue_status(cmd);
2680 }
2681 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2682 
2683 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2684 {
2685 	if (!(cmd->transport_state & CMD_T_ABORTED))
2686 		return 0;
2687 
2688 	if (!send_status || (cmd->se_cmd_flags & SCF_SENT_DELAYED_TAS))
2689 		return 1;
2690 
2691 	pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08x\n",
2692 		 cmd->t_task_cdb[0], cmd->se_tfo->get_task_tag(cmd));
2693 
2694 	cmd->se_cmd_flags |= SCF_SENT_DELAYED_TAS;
2695 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2696 	trace_target_cmd_complete(cmd);
2697 	cmd->se_tfo->queue_status(cmd);
2698 
2699 	return 1;
2700 }
2701 EXPORT_SYMBOL(transport_check_aborted_status);
2702 
2703 void transport_send_task_abort(struct se_cmd *cmd)
2704 {
2705 	unsigned long flags;
2706 
2707 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2708 	if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION | SCF_SENT_DELAYED_TAS)) {
2709 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2710 		return;
2711 	}
2712 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2713 
2714 	/*
2715 	 * If there are still expected incoming fabric WRITEs, we wait
2716 	 * until until they have completed before sending a TASK_ABORTED
2717 	 * response.  This response with TASK_ABORTED status will be
2718 	 * queued back to fabric module by transport_check_aborted_status().
2719 	 */
2720 	if (cmd->data_direction == DMA_TO_DEVICE) {
2721 		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
2722 			cmd->transport_state |= CMD_T_ABORTED;
2723 			smp_mb__after_atomic_inc();
2724 			return;
2725 		}
2726 	}
2727 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2728 
2729 	transport_lun_remove_cmd(cmd);
2730 
2731 	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
2732 		" ITT: 0x%08x\n", cmd->t_task_cdb[0],
2733 		cmd->se_tfo->get_task_tag(cmd));
2734 
2735 	trace_target_cmd_complete(cmd);
2736 	cmd->se_tfo->queue_status(cmd);
2737 }
2738 
2739 static void target_tmr_work(struct work_struct *work)
2740 {
2741 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2742 	struct se_device *dev = cmd->se_dev;
2743 	struct se_tmr_req *tmr = cmd->se_tmr_req;
2744 	int ret;
2745 
2746 	switch (tmr->function) {
2747 	case TMR_ABORT_TASK:
2748 		core_tmr_abort_task(dev, tmr, cmd->se_sess);
2749 		break;
2750 	case TMR_ABORT_TASK_SET:
2751 	case TMR_CLEAR_ACA:
2752 	case TMR_CLEAR_TASK_SET:
2753 		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
2754 		break;
2755 	case TMR_LUN_RESET:
2756 		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
2757 		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
2758 					 TMR_FUNCTION_REJECTED;
2759 		break;
2760 	case TMR_TARGET_WARM_RESET:
2761 		tmr->response = TMR_FUNCTION_REJECTED;
2762 		break;
2763 	case TMR_TARGET_COLD_RESET:
2764 		tmr->response = TMR_FUNCTION_REJECTED;
2765 		break;
2766 	default:
2767 		pr_err("Uknown TMR function: 0x%02x.\n",
2768 				tmr->function);
2769 		tmr->response = TMR_FUNCTION_REJECTED;
2770 		break;
2771 	}
2772 
2773 	cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
2774 	cmd->se_tfo->queue_tm_rsp(cmd);
2775 
2776 	transport_cmd_check_stop_to_fabric(cmd);
2777 }
2778 
2779 int transport_generic_handle_tmr(
2780 	struct se_cmd *cmd)
2781 {
2782 	INIT_WORK(&cmd->work, target_tmr_work);
2783 	queue_work(cmd->se_dev->tmr_wq, &cmd->work);
2784 	return 0;
2785 }
2786 EXPORT_SYMBOL(transport_generic_handle_tmr);
2787