xref: /linux/drivers/target/target_core_transport.c (revision e2f4ea40138e16d1dfd768f2dead8f3f75a85673)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*******************************************************************************
3  * Filename:  target_core_transport.c
4  *
5  * This file contains the Generic Target Engine Core.
6  *
7  * (c) Copyright 2002-2013 Datera, Inc.
8  *
9  * Nicholas A. Bellinger <nab@kernel.org>
10  *
11  ******************************************************************************/
12 
13 #include <linux/net.h>
14 #include <linux/delay.h>
15 #include <linux/string.h>
16 #include <linux/timer.h>
17 #include <linux/slab.h>
18 #include <linux/spinlock.h>
19 #include <linux/kthread.h>
20 #include <linux/in.h>
21 #include <linux/cdrom.h>
22 #include <linux/module.h>
23 #include <linux/ratelimit.h>
24 #include <linux/vmalloc.h>
25 #include <asm/unaligned.h>
26 #include <net/sock.h>
27 #include <net/tcp.h>
28 #include <scsi/scsi_proto.h>
29 #include <scsi/scsi_common.h>
30 
31 #include <target/target_core_base.h>
32 #include <target/target_core_backend.h>
33 #include <target/target_core_fabric.h>
34 
35 #include "target_core_internal.h"
36 #include "target_core_alua.h"
37 #include "target_core_pr.h"
38 #include "target_core_ua.h"
39 
40 #define CREATE_TRACE_POINTS
41 #include <trace/events/target.h>
42 
43 static struct workqueue_struct *target_completion_wq;
44 static struct workqueue_struct *target_submission_wq;
45 static struct kmem_cache *se_sess_cache;
46 struct kmem_cache *se_ua_cache;
47 struct kmem_cache *t10_pr_reg_cache;
48 struct kmem_cache *t10_alua_lu_gp_cache;
49 struct kmem_cache *t10_alua_lu_gp_mem_cache;
50 struct kmem_cache *t10_alua_tg_pt_gp_cache;
51 struct kmem_cache *t10_alua_lba_map_cache;
52 struct kmem_cache *t10_alua_lba_map_mem_cache;
53 
54 static void transport_complete_task_attr(struct se_cmd *cmd);
55 static void translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason);
56 static void transport_handle_queue_full(struct se_cmd *cmd,
57 		struct se_device *dev, int err, bool write_pending);
58 static void target_complete_ok_work(struct work_struct *work);
59 
60 int init_se_kmem_caches(void)
61 {
62 	se_sess_cache = kmem_cache_create("se_sess_cache",
63 			sizeof(struct se_session), __alignof__(struct se_session),
64 			0, NULL);
65 	if (!se_sess_cache) {
66 		pr_err("kmem_cache_create() for struct se_session"
67 				" failed\n");
68 		goto out;
69 	}
70 	se_ua_cache = kmem_cache_create("se_ua_cache",
71 			sizeof(struct se_ua), __alignof__(struct se_ua),
72 			0, NULL);
73 	if (!se_ua_cache) {
74 		pr_err("kmem_cache_create() for struct se_ua failed\n");
75 		goto out_free_sess_cache;
76 	}
77 	t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
78 			sizeof(struct t10_pr_registration),
79 			__alignof__(struct t10_pr_registration), 0, NULL);
80 	if (!t10_pr_reg_cache) {
81 		pr_err("kmem_cache_create() for struct t10_pr_registration"
82 				" failed\n");
83 		goto out_free_ua_cache;
84 	}
85 	t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
86 			sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
87 			0, NULL);
88 	if (!t10_alua_lu_gp_cache) {
89 		pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
90 				" failed\n");
91 		goto out_free_pr_reg_cache;
92 	}
93 	t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
94 			sizeof(struct t10_alua_lu_gp_member),
95 			__alignof__(struct t10_alua_lu_gp_member), 0, NULL);
96 	if (!t10_alua_lu_gp_mem_cache) {
97 		pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
98 				"cache failed\n");
99 		goto out_free_lu_gp_cache;
100 	}
101 	t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
102 			sizeof(struct t10_alua_tg_pt_gp),
103 			__alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
104 	if (!t10_alua_tg_pt_gp_cache) {
105 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
106 				"cache failed\n");
107 		goto out_free_lu_gp_mem_cache;
108 	}
109 	t10_alua_lba_map_cache = kmem_cache_create(
110 			"t10_alua_lba_map_cache",
111 			sizeof(struct t10_alua_lba_map),
112 			__alignof__(struct t10_alua_lba_map), 0, NULL);
113 	if (!t10_alua_lba_map_cache) {
114 		pr_err("kmem_cache_create() for t10_alua_lba_map_"
115 				"cache failed\n");
116 		goto out_free_tg_pt_gp_cache;
117 	}
118 	t10_alua_lba_map_mem_cache = kmem_cache_create(
119 			"t10_alua_lba_map_mem_cache",
120 			sizeof(struct t10_alua_lba_map_member),
121 			__alignof__(struct t10_alua_lba_map_member), 0, NULL);
122 	if (!t10_alua_lba_map_mem_cache) {
123 		pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
124 				"cache failed\n");
125 		goto out_free_lba_map_cache;
126 	}
127 
128 	target_completion_wq = alloc_workqueue("target_completion",
129 					       WQ_MEM_RECLAIM, 0);
130 	if (!target_completion_wq)
131 		goto out_free_lba_map_mem_cache;
132 
133 	target_submission_wq = alloc_workqueue("target_submission",
134 					       WQ_MEM_RECLAIM, 0);
135 	if (!target_submission_wq)
136 		goto out_free_completion_wq;
137 
138 	return 0;
139 
140 out_free_completion_wq:
141 	destroy_workqueue(target_completion_wq);
142 out_free_lba_map_mem_cache:
143 	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
144 out_free_lba_map_cache:
145 	kmem_cache_destroy(t10_alua_lba_map_cache);
146 out_free_tg_pt_gp_cache:
147 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
148 out_free_lu_gp_mem_cache:
149 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
150 out_free_lu_gp_cache:
151 	kmem_cache_destroy(t10_alua_lu_gp_cache);
152 out_free_pr_reg_cache:
153 	kmem_cache_destroy(t10_pr_reg_cache);
154 out_free_ua_cache:
155 	kmem_cache_destroy(se_ua_cache);
156 out_free_sess_cache:
157 	kmem_cache_destroy(se_sess_cache);
158 out:
159 	return -ENOMEM;
160 }
161 
162 void release_se_kmem_caches(void)
163 {
164 	destroy_workqueue(target_submission_wq);
165 	destroy_workqueue(target_completion_wq);
166 	kmem_cache_destroy(se_sess_cache);
167 	kmem_cache_destroy(se_ua_cache);
168 	kmem_cache_destroy(t10_pr_reg_cache);
169 	kmem_cache_destroy(t10_alua_lu_gp_cache);
170 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
171 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
172 	kmem_cache_destroy(t10_alua_lba_map_cache);
173 	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
174 }
175 
176 /* This code ensures unique mib indexes are handed out. */
177 static DEFINE_SPINLOCK(scsi_mib_index_lock);
178 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
179 
180 /*
181  * Allocate a new row index for the entry type specified
182  */
183 u32 scsi_get_new_index(scsi_index_t type)
184 {
185 	u32 new_index;
186 
187 	BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
188 
189 	spin_lock(&scsi_mib_index_lock);
190 	new_index = ++scsi_mib_index[type];
191 	spin_unlock(&scsi_mib_index_lock);
192 
193 	return new_index;
194 }
195 
196 void transport_subsystem_check_init(void)
197 {
198 	int ret;
199 	static int sub_api_initialized;
200 
201 	if (sub_api_initialized)
202 		return;
203 
204 	ret = IS_ENABLED(CONFIG_TCM_IBLOCK) && request_module("target_core_iblock");
205 	if (ret != 0)
206 		pr_err("Unable to load target_core_iblock\n");
207 
208 	ret = IS_ENABLED(CONFIG_TCM_FILEIO) && request_module("target_core_file");
209 	if (ret != 0)
210 		pr_err("Unable to load target_core_file\n");
211 
212 	ret = IS_ENABLED(CONFIG_TCM_PSCSI) && request_module("target_core_pscsi");
213 	if (ret != 0)
214 		pr_err("Unable to load target_core_pscsi\n");
215 
216 	ret = IS_ENABLED(CONFIG_TCM_USER2) && request_module("target_core_user");
217 	if (ret != 0)
218 		pr_err("Unable to load target_core_user\n");
219 
220 	sub_api_initialized = 1;
221 }
222 
223 static void target_release_cmd_refcnt(struct percpu_ref *ref)
224 {
225 	struct target_cmd_counter *cmd_cnt  = container_of(ref,
226 							   typeof(*cmd_cnt),
227 							   refcnt);
228 	wake_up(&cmd_cnt->refcnt_wq);
229 }
230 
231 struct target_cmd_counter *target_alloc_cmd_counter(void)
232 {
233 	struct target_cmd_counter *cmd_cnt;
234 	int rc;
235 
236 	cmd_cnt = kzalloc(sizeof(*cmd_cnt), GFP_KERNEL);
237 	if (!cmd_cnt)
238 		return NULL;
239 
240 	init_completion(&cmd_cnt->stop_done);
241 	init_waitqueue_head(&cmd_cnt->refcnt_wq);
242 	atomic_set(&cmd_cnt->stopped, 0);
243 
244 	rc = percpu_ref_init(&cmd_cnt->refcnt, target_release_cmd_refcnt, 0,
245 			     GFP_KERNEL);
246 	if (rc)
247 		goto free_cmd_cnt;
248 
249 	return cmd_cnt;
250 
251 free_cmd_cnt:
252 	kfree(cmd_cnt);
253 	return NULL;
254 }
255 EXPORT_SYMBOL_GPL(target_alloc_cmd_counter);
256 
257 void target_free_cmd_counter(struct target_cmd_counter *cmd_cnt)
258 {
259 	/*
260 	 * Drivers like loop do not call target_stop_session during session
261 	 * shutdown so we have to drop the ref taken at init time here.
262 	 */
263 	if (!atomic_read(&cmd_cnt->stopped))
264 		percpu_ref_put(&cmd_cnt->refcnt);
265 
266 	percpu_ref_exit(&cmd_cnt->refcnt);
267 }
268 EXPORT_SYMBOL_GPL(target_free_cmd_counter);
269 
270 /**
271  * transport_init_session - initialize a session object
272  * @se_sess: Session object pointer.
273  *
274  * The caller must have zero-initialized @se_sess before calling this function.
275  */
276 void transport_init_session(struct se_session *se_sess)
277 {
278 	INIT_LIST_HEAD(&se_sess->sess_list);
279 	INIT_LIST_HEAD(&se_sess->sess_acl_list);
280 	spin_lock_init(&se_sess->sess_cmd_lock);
281 }
282 EXPORT_SYMBOL(transport_init_session);
283 
284 /**
285  * transport_alloc_session - allocate a session object and initialize it
286  * @sup_prot_ops: bitmask that defines which T10-PI modes are supported.
287  */
288 struct se_session *transport_alloc_session(enum target_prot_op sup_prot_ops)
289 {
290 	struct se_session *se_sess;
291 
292 	se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
293 	if (!se_sess) {
294 		pr_err("Unable to allocate struct se_session from"
295 				" se_sess_cache\n");
296 		return ERR_PTR(-ENOMEM);
297 	}
298 	transport_init_session(se_sess);
299 	se_sess->sup_prot_ops = sup_prot_ops;
300 
301 	return se_sess;
302 }
303 EXPORT_SYMBOL(transport_alloc_session);
304 
305 /**
306  * transport_alloc_session_tags - allocate target driver private data
307  * @se_sess:  Session pointer.
308  * @tag_num:  Maximum number of in-flight commands between initiator and target.
309  * @tag_size: Size in bytes of the private data a target driver associates with
310  *	      each command.
311  */
312 int transport_alloc_session_tags(struct se_session *se_sess,
313 			         unsigned int tag_num, unsigned int tag_size)
314 {
315 	int rc;
316 
317 	se_sess->sess_cmd_map = kvcalloc(tag_size, tag_num,
318 					 GFP_KERNEL | __GFP_RETRY_MAYFAIL);
319 	if (!se_sess->sess_cmd_map) {
320 		pr_err("Unable to allocate se_sess->sess_cmd_map\n");
321 		return -ENOMEM;
322 	}
323 
324 	rc = sbitmap_queue_init_node(&se_sess->sess_tag_pool, tag_num, -1,
325 			false, GFP_KERNEL, NUMA_NO_NODE);
326 	if (rc < 0) {
327 		pr_err("Unable to init se_sess->sess_tag_pool,"
328 			" tag_num: %u\n", tag_num);
329 		kvfree(se_sess->sess_cmd_map);
330 		se_sess->sess_cmd_map = NULL;
331 		return -ENOMEM;
332 	}
333 
334 	return 0;
335 }
336 EXPORT_SYMBOL(transport_alloc_session_tags);
337 
338 /**
339  * transport_init_session_tags - allocate a session and target driver private data
340  * @tag_num:  Maximum number of in-flight commands between initiator and target.
341  * @tag_size: Size in bytes of the private data a target driver associates with
342  *	      each command.
343  * @sup_prot_ops: bitmask that defines which T10-PI modes are supported.
344  */
345 static struct se_session *
346 transport_init_session_tags(unsigned int tag_num, unsigned int tag_size,
347 			    enum target_prot_op sup_prot_ops)
348 {
349 	struct se_session *se_sess;
350 	int rc;
351 
352 	if (tag_num != 0 && !tag_size) {
353 		pr_err("init_session_tags called with percpu-ida tag_num:"
354 		       " %u, but zero tag_size\n", tag_num);
355 		return ERR_PTR(-EINVAL);
356 	}
357 	if (!tag_num && tag_size) {
358 		pr_err("init_session_tags called with percpu-ida tag_size:"
359 		       " %u, but zero tag_num\n", tag_size);
360 		return ERR_PTR(-EINVAL);
361 	}
362 
363 	se_sess = transport_alloc_session(sup_prot_ops);
364 	if (IS_ERR(se_sess))
365 		return se_sess;
366 
367 	rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
368 	if (rc < 0) {
369 		transport_free_session(se_sess);
370 		return ERR_PTR(-ENOMEM);
371 	}
372 
373 	return se_sess;
374 }
375 
376 /*
377  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
378  */
379 void __transport_register_session(
380 	struct se_portal_group *se_tpg,
381 	struct se_node_acl *se_nacl,
382 	struct se_session *se_sess,
383 	void *fabric_sess_ptr)
384 {
385 	const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
386 	unsigned char buf[PR_REG_ISID_LEN];
387 	unsigned long flags;
388 
389 	se_sess->se_tpg = se_tpg;
390 	se_sess->fabric_sess_ptr = fabric_sess_ptr;
391 	/*
392 	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
393 	 *
394 	 * Only set for struct se_session's that will actually be moving I/O.
395 	 * eg: *NOT* discovery sessions.
396 	 */
397 	if (se_nacl) {
398 		/*
399 		 *
400 		 * Determine if fabric allows for T10-PI feature bits exposed to
401 		 * initiators for device backends with !dev->dev_attrib.pi_prot_type.
402 		 *
403 		 * If so, then always save prot_type on a per se_node_acl node
404 		 * basis and re-instate the previous sess_prot_type to avoid
405 		 * disabling PI from below any previously initiator side
406 		 * registered LUNs.
407 		 */
408 		if (se_nacl->saved_prot_type)
409 			se_sess->sess_prot_type = se_nacl->saved_prot_type;
410 		else if (tfo->tpg_check_prot_fabric_only)
411 			se_sess->sess_prot_type = se_nacl->saved_prot_type =
412 					tfo->tpg_check_prot_fabric_only(se_tpg);
413 		/*
414 		 * If the fabric module supports an ISID based TransportID,
415 		 * save this value in binary from the fabric I_T Nexus now.
416 		 */
417 		if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
418 			memset(&buf[0], 0, PR_REG_ISID_LEN);
419 			se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
420 					&buf[0], PR_REG_ISID_LEN);
421 			se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
422 		}
423 
424 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
425 		/*
426 		 * The se_nacl->nacl_sess pointer will be set to the
427 		 * last active I_T Nexus for each struct se_node_acl.
428 		 */
429 		se_nacl->nacl_sess = se_sess;
430 
431 		list_add_tail(&se_sess->sess_acl_list,
432 			      &se_nacl->acl_sess_list);
433 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
434 	}
435 	list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
436 
437 	pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
438 		se_tpg->se_tpg_tfo->fabric_name, se_sess->fabric_sess_ptr);
439 }
440 EXPORT_SYMBOL(__transport_register_session);
441 
442 void transport_register_session(
443 	struct se_portal_group *se_tpg,
444 	struct se_node_acl *se_nacl,
445 	struct se_session *se_sess,
446 	void *fabric_sess_ptr)
447 {
448 	unsigned long flags;
449 
450 	spin_lock_irqsave(&se_tpg->session_lock, flags);
451 	__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
452 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
453 }
454 EXPORT_SYMBOL(transport_register_session);
455 
456 struct se_session *
457 target_setup_session(struct se_portal_group *tpg,
458 		     unsigned int tag_num, unsigned int tag_size,
459 		     enum target_prot_op prot_op,
460 		     const char *initiatorname, void *private,
461 		     int (*callback)(struct se_portal_group *,
462 				     struct se_session *, void *))
463 {
464 	struct target_cmd_counter *cmd_cnt;
465 	struct se_session *sess;
466 	int rc;
467 
468 	cmd_cnt = target_alloc_cmd_counter();
469 	if (!cmd_cnt)
470 		return ERR_PTR(-ENOMEM);
471 	/*
472 	 * If the fabric driver is using percpu-ida based pre allocation
473 	 * of I/O descriptor tags, go ahead and perform that setup now..
474 	 */
475 	if (tag_num != 0)
476 		sess = transport_init_session_tags(tag_num, tag_size, prot_op);
477 	else
478 		sess = transport_alloc_session(prot_op);
479 
480 	if (IS_ERR(sess)) {
481 		rc = PTR_ERR(sess);
482 		goto free_cnt;
483 	}
484 	sess->cmd_cnt = cmd_cnt;
485 
486 	sess->se_node_acl = core_tpg_check_initiator_node_acl(tpg,
487 					(unsigned char *)initiatorname);
488 	if (!sess->se_node_acl) {
489 		rc = -EACCES;
490 		goto free_sess;
491 	}
492 	/*
493 	 * Go ahead and perform any remaining fabric setup that is
494 	 * required before transport_register_session().
495 	 */
496 	if (callback != NULL) {
497 		rc = callback(tpg, sess, private);
498 		if (rc)
499 			goto free_sess;
500 	}
501 
502 	transport_register_session(tpg, sess->se_node_acl, sess, private);
503 	return sess;
504 
505 free_sess:
506 	transport_free_session(sess);
507 	return ERR_PTR(rc);
508 
509 free_cnt:
510 	target_free_cmd_counter(cmd_cnt);
511 	return ERR_PTR(rc);
512 }
513 EXPORT_SYMBOL(target_setup_session);
514 
515 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
516 {
517 	struct se_session *se_sess;
518 	ssize_t len = 0;
519 
520 	spin_lock_bh(&se_tpg->session_lock);
521 	list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
522 		if (!se_sess->se_node_acl)
523 			continue;
524 		if (!se_sess->se_node_acl->dynamic_node_acl)
525 			continue;
526 		if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
527 			break;
528 
529 		len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
530 				se_sess->se_node_acl->initiatorname);
531 		len += 1; /* Include NULL terminator */
532 	}
533 	spin_unlock_bh(&se_tpg->session_lock);
534 
535 	return len;
536 }
537 EXPORT_SYMBOL(target_show_dynamic_sessions);
538 
539 static void target_complete_nacl(struct kref *kref)
540 {
541 	struct se_node_acl *nacl = container_of(kref,
542 				struct se_node_acl, acl_kref);
543 	struct se_portal_group *se_tpg = nacl->se_tpg;
544 
545 	if (!nacl->dynamic_stop) {
546 		complete(&nacl->acl_free_comp);
547 		return;
548 	}
549 
550 	mutex_lock(&se_tpg->acl_node_mutex);
551 	list_del_init(&nacl->acl_list);
552 	mutex_unlock(&se_tpg->acl_node_mutex);
553 
554 	core_tpg_wait_for_nacl_pr_ref(nacl);
555 	core_free_device_list_for_node(nacl, se_tpg);
556 	kfree(nacl);
557 }
558 
559 void target_put_nacl(struct se_node_acl *nacl)
560 {
561 	kref_put(&nacl->acl_kref, target_complete_nacl);
562 }
563 EXPORT_SYMBOL(target_put_nacl);
564 
565 void transport_deregister_session_configfs(struct se_session *se_sess)
566 {
567 	struct se_node_acl *se_nacl;
568 	unsigned long flags;
569 	/*
570 	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
571 	 */
572 	se_nacl = se_sess->se_node_acl;
573 	if (se_nacl) {
574 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
575 		if (!list_empty(&se_sess->sess_acl_list))
576 			list_del_init(&se_sess->sess_acl_list);
577 		/*
578 		 * If the session list is empty, then clear the pointer.
579 		 * Otherwise, set the struct se_session pointer from the tail
580 		 * element of the per struct se_node_acl active session list.
581 		 */
582 		if (list_empty(&se_nacl->acl_sess_list))
583 			se_nacl->nacl_sess = NULL;
584 		else {
585 			se_nacl->nacl_sess = container_of(
586 					se_nacl->acl_sess_list.prev,
587 					struct se_session, sess_acl_list);
588 		}
589 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
590 	}
591 }
592 EXPORT_SYMBOL(transport_deregister_session_configfs);
593 
594 void transport_free_session(struct se_session *se_sess)
595 {
596 	struct se_node_acl *se_nacl = se_sess->se_node_acl;
597 
598 	/*
599 	 * Drop the se_node_acl->nacl_kref obtained from within
600 	 * core_tpg_get_initiator_node_acl().
601 	 */
602 	if (se_nacl) {
603 		struct se_portal_group *se_tpg = se_nacl->se_tpg;
604 		const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo;
605 		unsigned long flags;
606 
607 		se_sess->se_node_acl = NULL;
608 
609 		/*
610 		 * Also determine if we need to drop the extra ->cmd_kref if
611 		 * it had been previously dynamically generated, and
612 		 * the endpoint is not caching dynamic ACLs.
613 		 */
614 		mutex_lock(&se_tpg->acl_node_mutex);
615 		if (se_nacl->dynamic_node_acl &&
616 		    !se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
617 			spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
618 			if (list_empty(&se_nacl->acl_sess_list))
619 				se_nacl->dynamic_stop = true;
620 			spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
621 
622 			if (se_nacl->dynamic_stop)
623 				list_del_init(&se_nacl->acl_list);
624 		}
625 		mutex_unlock(&se_tpg->acl_node_mutex);
626 
627 		if (se_nacl->dynamic_stop)
628 			target_put_nacl(se_nacl);
629 
630 		target_put_nacl(se_nacl);
631 	}
632 	if (se_sess->sess_cmd_map) {
633 		sbitmap_queue_free(&se_sess->sess_tag_pool);
634 		kvfree(se_sess->sess_cmd_map);
635 	}
636 	if (se_sess->cmd_cnt)
637 		target_free_cmd_counter(se_sess->cmd_cnt);
638 	kmem_cache_free(se_sess_cache, se_sess);
639 }
640 EXPORT_SYMBOL(transport_free_session);
641 
642 static int target_release_res(struct se_device *dev, void *data)
643 {
644 	struct se_session *sess = data;
645 
646 	if (dev->reservation_holder == sess)
647 		target_release_reservation(dev);
648 	return 0;
649 }
650 
651 void transport_deregister_session(struct se_session *se_sess)
652 {
653 	struct se_portal_group *se_tpg = se_sess->se_tpg;
654 	unsigned long flags;
655 
656 	if (!se_tpg) {
657 		transport_free_session(se_sess);
658 		return;
659 	}
660 
661 	spin_lock_irqsave(&se_tpg->session_lock, flags);
662 	list_del(&se_sess->sess_list);
663 	se_sess->se_tpg = NULL;
664 	se_sess->fabric_sess_ptr = NULL;
665 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
666 
667 	/*
668 	 * Since the session is being removed, release SPC-2
669 	 * reservations held by the session that is disappearing.
670 	 */
671 	target_for_each_device(target_release_res, se_sess);
672 
673 	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
674 		se_tpg->se_tpg_tfo->fabric_name);
675 	/*
676 	 * If last kref is dropping now for an explicit NodeACL, awake sleeping
677 	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
678 	 * removal context from within transport_free_session() code.
679 	 *
680 	 * For dynamic ACL, target_put_nacl() uses target_complete_nacl()
681 	 * to release all remaining generate_node_acl=1 created ACL resources.
682 	 */
683 
684 	transport_free_session(se_sess);
685 }
686 EXPORT_SYMBOL(transport_deregister_session);
687 
688 void target_remove_session(struct se_session *se_sess)
689 {
690 	transport_deregister_session_configfs(se_sess);
691 	transport_deregister_session(se_sess);
692 }
693 EXPORT_SYMBOL(target_remove_session);
694 
695 static void target_remove_from_state_list(struct se_cmd *cmd)
696 {
697 	struct se_device *dev = cmd->se_dev;
698 	unsigned long flags;
699 
700 	if (!dev)
701 		return;
702 
703 	spin_lock_irqsave(&dev->queues[cmd->cpuid].lock, flags);
704 	if (cmd->state_active) {
705 		list_del(&cmd->state_list);
706 		cmd->state_active = false;
707 	}
708 	spin_unlock_irqrestore(&dev->queues[cmd->cpuid].lock, flags);
709 }
710 
711 static void target_remove_from_tmr_list(struct se_cmd *cmd)
712 {
713 	struct se_device *dev = NULL;
714 	unsigned long flags;
715 
716 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
717 		dev = cmd->se_tmr_req->tmr_dev;
718 
719 	if (dev) {
720 		spin_lock_irqsave(&dev->se_tmr_lock, flags);
721 		if (cmd->se_tmr_req->tmr_dev)
722 			list_del_init(&cmd->se_tmr_req->tmr_list);
723 		spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
724 	}
725 }
726 /*
727  * This function is called by the target core after the target core has
728  * finished processing a SCSI command or SCSI TMF. Both the regular command
729  * processing code and the code for aborting commands can call this
730  * function. CMD_T_STOP is set if and only if another thread is waiting
731  * inside transport_wait_for_tasks() for t_transport_stop_comp.
732  */
733 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
734 {
735 	unsigned long flags;
736 
737 	spin_lock_irqsave(&cmd->t_state_lock, flags);
738 	/*
739 	 * Determine if frontend context caller is requesting the stopping of
740 	 * this command for frontend exceptions.
741 	 */
742 	if (cmd->transport_state & CMD_T_STOP) {
743 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
744 			__func__, __LINE__, cmd->tag);
745 
746 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
747 
748 		complete_all(&cmd->t_transport_stop_comp);
749 		return 1;
750 	}
751 	cmd->transport_state &= ~CMD_T_ACTIVE;
752 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
753 
754 	/*
755 	 * Some fabric modules like tcm_loop can release their internally
756 	 * allocated I/O reference and struct se_cmd now.
757 	 *
758 	 * Fabric modules are expected to return '1' here if the se_cmd being
759 	 * passed is released at this point, or zero if not being released.
760 	 */
761 	return cmd->se_tfo->check_stop_free(cmd);
762 }
763 
764 static void transport_lun_remove_cmd(struct se_cmd *cmd)
765 {
766 	struct se_lun *lun = cmd->se_lun;
767 
768 	if (!lun)
769 		return;
770 
771 	target_remove_from_state_list(cmd);
772 	target_remove_from_tmr_list(cmd);
773 
774 	if (cmpxchg(&cmd->lun_ref_active, true, false))
775 		percpu_ref_put(&lun->lun_ref);
776 
777 	/*
778 	 * Clear struct se_cmd->se_lun before the handoff to FE.
779 	 */
780 	cmd->se_lun = NULL;
781 }
782 
783 static void target_complete_failure_work(struct work_struct *work)
784 {
785 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
786 
787 	transport_generic_request_failure(cmd, cmd->sense_reason);
788 }
789 
790 /*
791  * Used when asking transport to copy Sense Data from the underlying
792  * Linux/SCSI struct scsi_cmnd
793  */
794 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
795 {
796 	struct se_device *dev = cmd->se_dev;
797 
798 	WARN_ON(!cmd->se_lun);
799 
800 	if (!dev)
801 		return NULL;
802 
803 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
804 		return NULL;
805 
806 	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
807 
808 	pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
809 		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
810 	return cmd->sense_buffer;
811 }
812 
813 void transport_copy_sense_to_cmd(struct se_cmd *cmd, unsigned char *sense)
814 {
815 	unsigned char *cmd_sense_buf;
816 	unsigned long flags;
817 
818 	spin_lock_irqsave(&cmd->t_state_lock, flags);
819 	cmd_sense_buf = transport_get_sense_buffer(cmd);
820 	if (!cmd_sense_buf) {
821 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
822 		return;
823 	}
824 
825 	cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
826 	memcpy(cmd_sense_buf, sense, cmd->scsi_sense_length);
827 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
828 }
829 EXPORT_SYMBOL(transport_copy_sense_to_cmd);
830 
831 static void target_handle_abort(struct se_cmd *cmd)
832 {
833 	bool tas = cmd->transport_state & CMD_T_TAS;
834 	bool ack_kref = cmd->se_cmd_flags & SCF_ACK_KREF;
835 	int ret;
836 
837 	pr_debug("tag %#llx: send_abort_response = %d\n", cmd->tag, tas);
838 
839 	if (tas) {
840 		if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
841 			cmd->scsi_status = SAM_STAT_TASK_ABORTED;
842 			pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
843 				 cmd->t_task_cdb[0], cmd->tag);
844 			trace_target_cmd_complete(cmd);
845 			ret = cmd->se_tfo->queue_status(cmd);
846 			if (ret) {
847 				transport_handle_queue_full(cmd, cmd->se_dev,
848 							    ret, false);
849 				return;
850 			}
851 		} else {
852 			cmd->se_tmr_req->response = TMR_FUNCTION_REJECTED;
853 			cmd->se_tfo->queue_tm_rsp(cmd);
854 		}
855 	} else {
856 		/*
857 		 * Allow the fabric driver to unmap any resources before
858 		 * releasing the descriptor via TFO->release_cmd().
859 		 */
860 		cmd->se_tfo->aborted_task(cmd);
861 		if (ack_kref)
862 			WARN_ON_ONCE(target_put_sess_cmd(cmd) != 0);
863 		/*
864 		 * To do: establish a unit attention condition on the I_T
865 		 * nexus associated with cmd. See also the paragraph "Aborting
866 		 * commands" in SAM.
867 		 */
868 	}
869 
870 	WARN_ON_ONCE(kref_read(&cmd->cmd_kref) == 0);
871 
872 	transport_lun_remove_cmd(cmd);
873 
874 	transport_cmd_check_stop_to_fabric(cmd);
875 }
876 
877 static void target_abort_work(struct work_struct *work)
878 {
879 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
880 
881 	target_handle_abort(cmd);
882 }
883 
884 static bool target_cmd_interrupted(struct se_cmd *cmd)
885 {
886 	int post_ret;
887 
888 	if (cmd->transport_state & CMD_T_ABORTED) {
889 		if (cmd->transport_complete_callback)
890 			cmd->transport_complete_callback(cmd, false, &post_ret);
891 		INIT_WORK(&cmd->work, target_abort_work);
892 		queue_work(target_completion_wq, &cmd->work);
893 		return true;
894 	} else if (cmd->transport_state & CMD_T_STOP) {
895 		if (cmd->transport_complete_callback)
896 			cmd->transport_complete_callback(cmd, false, &post_ret);
897 		complete_all(&cmd->t_transport_stop_comp);
898 		return true;
899 	}
900 
901 	return false;
902 }
903 
904 /* May be called from interrupt context so must not sleep. */
905 void target_complete_cmd_with_sense(struct se_cmd *cmd, u8 scsi_status,
906 				    sense_reason_t sense_reason)
907 {
908 	struct se_wwn *wwn = cmd->se_sess->se_tpg->se_tpg_wwn;
909 	int success, cpu;
910 	unsigned long flags;
911 
912 	if (target_cmd_interrupted(cmd))
913 		return;
914 
915 	cmd->scsi_status = scsi_status;
916 	cmd->sense_reason = sense_reason;
917 
918 	spin_lock_irqsave(&cmd->t_state_lock, flags);
919 	switch (cmd->scsi_status) {
920 	case SAM_STAT_CHECK_CONDITION:
921 		if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
922 			success = 1;
923 		else
924 			success = 0;
925 		break;
926 	default:
927 		success = 1;
928 		break;
929 	}
930 
931 	cmd->t_state = TRANSPORT_COMPLETE;
932 	cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
933 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
934 
935 	INIT_WORK(&cmd->work, success ? target_complete_ok_work :
936 		  target_complete_failure_work);
937 
938 	if (!wwn || wwn->cmd_compl_affinity == SE_COMPL_AFFINITY_CPUID)
939 		cpu = cmd->cpuid;
940 	else
941 		cpu = wwn->cmd_compl_affinity;
942 
943 	queue_work_on(cpu, target_completion_wq, &cmd->work);
944 }
945 EXPORT_SYMBOL(target_complete_cmd_with_sense);
946 
947 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
948 {
949 	target_complete_cmd_with_sense(cmd, scsi_status, scsi_status ?
950 			      TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE :
951 			      TCM_NO_SENSE);
952 }
953 EXPORT_SYMBOL(target_complete_cmd);
954 
955 void target_set_cmd_data_length(struct se_cmd *cmd, int length)
956 {
957 	if (length < cmd->data_length) {
958 		if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
959 			cmd->residual_count += cmd->data_length - length;
960 		} else {
961 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
962 			cmd->residual_count = cmd->data_length - length;
963 		}
964 
965 		cmd->data_length = length;
966 	}
967 }
968 EXPORT_SYMBOL(target_set_cmd_data_length);
969 
970 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
971 {
972 	if (scsi_status == SAM_STAT_GOOD ||
973 	    cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) {
974 		target_set_cmd_data_length(cmd, length);
975 	}
976 
977 	target_complete_cmd(cmd, scsi_status);
978 }
979 EXPORT_SYMBOL(target_complete_cmd_with_length);
980 
981 static void target_add_to_state_list(struct se_cmd *cmd)
982 {
983 	struct se_device *dev = cmd->se_dev;
984 	unsigned long flags;
985 
986 	spin_lock_irqsave(&dev->queues[cmd->cpuid].lock, flags);
987 	if (!cmd->state_active) {
988 		list_add_tail(&cmd->state_list,
989 			      &dev->queues[cmd->cpuid].state_list);
990 		cmd->state_active = true;
991 	}
992 	spin_unlock_irqrestore(&dev->queues[cmd->cpuid].lock, flags);
993 }
994 
995 /*
996  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
997  */
998 static void transport_write_pending_qf(struct se_cmd *cmd);
999 static void transport_complete_qf(struct se_cmd *cmd);
1000 
1001 void target_qf_do_work(struct work_struct *work)
1002 {
1003 	struct se_device *dev = container_of(work, struct se_device,
1004 					qf_work_queue);
1005 	LIST_HEAD(qf_cmd_list);
1006 	struct se_cmd *cmd, *cmd_tmp;
1007 
1008 	spin_lock_irq(&dev->qf_cmd_lock);
1009 	list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
1010 	spin_unlock_irq(&dev->qf_cmd_lock);
1011 
1012 	list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
1013 		list_del(&cmd->se_qf_node);
1014 		atomic_dec_mb(&dev->dev_qf_count);
1015 
1016 		pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
1017 			" context: %s\n", cmd->se_tfo->fabric_name, cmd,
1018 			(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
1019 			(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
1020 			: "UNKNOWN");
1021 
1022 		if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
1023 			transport_write_pending_qf(cmd);
1024 		else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK ||
1025 			 cmd->t_state == TRANSPORT_COMPLETE_QF_ERR)
1026 			transport_complete_qf(cmd);
1027 	}
1028 }
1029 
1030 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
1031 {
1032 	switch (cmd->data_direction) {
1033 	case DMA_NONE:
1034 		return "NONE";
1035 	case DMA_FROM_DEVICE:
1036 		return "READ";
1037 	case DMA_TO_DEVICE:
1038 		return "WRITE";
1039 	case DMA_BIDIRECTIONAL:
1040 		return "BIDI";
1041 	default:
1042 		break;
1043 	}
1044 
1045 	return "UNKNOWN";
1046 }
1047 
1048 void transport_dump_dev_state(
1049 	struct se_device *dev,
1050 	char *b,
1051 	int *bl)
1052 {
1053 	*bl += sprintf(b + *bl, "Status: ");
1054 	if (dev->export_count)
1055 		*bl += sprintf(b + *bl, "ACTIVATED");
1056 	else
1057 		*bl += sprintf(b + *bl, "DEACTIVATED");
1058 
1059 	*bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
1060 	*bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
1061 		dev->dev_attrib.block_size,
1062 		dev->dev_attrib.hw_max_sectors);
1063 	*bl += sprintf(b + *bl, "        ");
1064 }
1065 
1066 void transport_dump_vpd_proto_id(
1067 	struct t10_vpd *vpd,
1068 	unsigned char *p_buf,
1069 	int p_buf_len)
1070 {
1071 	unsigned char buf[VPD_TMP_BUF_SIZE];
1072 	int len;
1073 
1074 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1075 	len = sprintf(buf, "T10 VPD Protocol Identifier: ");
1076 
1077 	switch (vpd->protocol_identifier) {
1078 	case 0x00:
1079 		sprintf(buf+len, "Fibre Channel\n");
1080 		break;
1081 	case 0x10:
1082 		sprintf(buf+len, "Parallel SCSI\n");
1083 		break;
1084 	case 0x20:
1085 		sprintf(buf+len, "SSA\n");
1086 		break;
1087 	case 0x30:
1088 		sprintf(buf+len, "IEEE 1394\n");
1089 		break;
1090 	case 0x40:
1091 		sprintf(buf+len, "SCSI Remote Direct Memory Access"
1092 				" Protocol\n");
1093 		break;
1094 	case 0x50:
1095 		sprintf(buf+len, "Internet SCSI (iSCSI)\n");
1096 		break;
1097 	case 0x60:
1098 		sprintf(buf+len, "SAS Serial SCSI Protocol\n");
1099 		break;
1100 	case 0x70:
1101 		sprintf(buf+len, "Automation/Drive Interface Transport"
1102 				" Protocol\n");
1103 		break;
1104 	case 0x80:
1105 		sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
1106 		break;
1107 	default:
1108 		sprintf(buf+len, "Unknown 0x%02x\n",
1109 				vpd->protocol_identifier);
1110 		break;
1111 	}
1112 
1113 	if (p_buf)
1114 		strncpy(p_buf, buf, p_buf_len);
1115 	else
1116 		pr_debug("%s", buf);
1117 }
1118 
1119 void
1120 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
1121 {
1122 	/*
1123 	 * Check if the Protocol Identifier Valid (PIV) bit is set..
1124 	 *
1125 	 * from spc3r23.pdf section 7.5.1
1126 	 */
1127 	 if (page_83[1] & 0x80) {
1128 		vpd->protocol_identifier = (page_83[0] & 0xf0);
1129 		vpd->protocol_identifier_set = 1;
1130 		transport_dump_vpd_proto_id(vpd, NULL, 0);
1131 	}
1132 }
1133 EXPORT_SYMBOL(transport_set_vpd_proto_id);
1134 
1135 int transport_dump_vpd_assoc(
1136 	struct t10_vpd *vpd,
1137 	unsigned char *p_buf,
1138 	int p_buf_len)
1139 {
1140 	unsigned char buf[VPD_TMP_BUF_SIZE];
1141 	int ret = 0;
1142 	int len;
1143 
1144 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1145 	len = sprintf(buf, "T10 VPD Identifier Association: ");
1146 
1147 	switch (vpd->association) {
1148 	case 0x00:
1149 		sprintf(buf+len, "addressed logical unit\n");
1150 		break;
1151 	case 0x10:
1152 		sprintf(buf+len, "target port\n");
1153 		break;
1154 	case 0x20:
1155 		sprintf(buf+len, "SCSI target device\n");
1156 		break;
1157 	default:
1158 		sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
1159 		ret = -EINVAL;
1160 		break;
1161 	}
1162 
1163 	if (p_buf)
1164 		strncpy(p_buf, buf, p_buf_len);
1165 	else
1166 		pr_debug("%s", buf);
1167 
1168 	return ret;
1169 }
1170 
1171 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
1172 {
1173 	/*
1174 	 * The VPD identification association..
1175 	 *
1176 	 * from spc3r23.pdf Section 7.6.3.1 Table 297
1177 	 */
1178 	vpd->association = (page_83[1] & 0x30);
1179 	return transport_dump_vpd_assoc(vpd, NULL, 0);
1180 }
1181 EXPORT_SYMBOL(transport_set_vpd_assoc);
1182 
1183 int transport_dump_vpd_ident_type(
1184 	struct t10_vpd *vpd,
1185 	unsigned char *p_buf,
1186 	int p_buf_len)
1187 {
1188 	unsigned char buf[VPD_TMP_BUF_SIZE];
1189 	int ret = 0;
1190 	int len;
1191 
1192 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1193 	len = sprintf(buf, "T10 VPD Identifier Type: ");
1194 
1195 	switch (vpd->device_identifier_type) {
1196 	case 0x00:
1197 		sprintf(buf+len, "Vendor specific\n");
1198 		break;
1199 	case 0x01:
1200 		sprintf(buf+len, "T10 Vendor ID based\n");
1201 		break;
1202 	case 0x02:
1203 		sprintf(buf+len, "EUI-64 based\n");
1204 		break;
1205 	case 0x03:
1206 		sprintf(buf+len, "NAA\n");
1207 		break;
1208 	case 0x04:
1209 		sprintf(buf+len, "Relative target port identifier\n");
1210 		break;
1211 	case 0x08:
1212 		sprintf(buf+len, "SCSI name string\n");
1213 		break;
1214 	default:
1215 		sprintf(buf+len, "Unsupported: 0x%02x\n",
1216 				vpd->device_identifier_type);
1217 		ret = -EINVAL;
1218 		break;
1219 	}
1220 
1221 	if (p_buf) {
1222 		if (p_buf_len < strlen(buf)+1)
1223 			return -EINVAL;
1224 		strncpy(p_buf, buf, p_buf_len);
1225 	} else {
1226 		pr_debug("%s", buf);
1227 	}
1228 
1229 	return ret;
1230 }
1231 
1232 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1233 {
1234 	/*
1235 	 * The VPD identifier type..
1236 	 *
1237 	 * from spc3r23.pdf Section 7.6.3.1 Table 298
1238 	 */
1239 	vpd->device_identifier_type = (page_83[1] & 0x0f);
1240 	return transport_dump_vpd_ident_type(vpd, NULL, 0);
1241 }
1242 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1243 
1244 int transport_dump_vpd_ident(
1245 	struct t10_vpd *vpd,
1246 	unsigned char *p_buf,
1247 	int p_buf_len)
1248 {
1249 	unsigned char buf[VPD_TMP_BUF_SIZE];
1250 	int ret = 0;
1251 
1252 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1253 
1254 	switch (vpd->device_identifier_code_set) {
1255 	case 0x01: /* Binary */
1256 		snprintf(buf, sizeof(buf),
1257 			"T10 VPD Binary Device Identifier: %s\n",
1258 			&vpd->device_identifier[0]);
1259 		break;
1260 	case 0x02: /* ASCII */
1261 		snprintf(buf, sizeof(buf),
1262 			"T10 VPD ASCII Device Identifier: %s\n",
1263 			&vpd->device_identifier[0]);
1264 		break;
1265 	case 0x03: /* UTF-8 */
1266 		snprintf(buf, sizeof(buf),
1267 			"T10 VPD UTF-8 Device Identifier: %s\n",
1268 			&vpd->device_identifier[0]);
1269 		break;
1270 	default:
1271 		sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1272 			" 0x%02x", vpd->device_identifier_code_set);
1273 		ret = -EINVAL;
1274 		break;
1275 	}
1276 
1277 	if (p_buf)
1278 		strncpy(p_buf, buf, p_buf_len);
1279 	else
1280 		pr_debug("%s", buf);
1281 
1282 	return ret;
1283 }
1284 
1285 int
1286 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1287 {
1288 	static const char hex_str[] = "0123456789abcdef";
1289 	int j = 0, i = 4; /* offset to start of the identifier */
1290 
1291 	/*
1292 	 * The VPD Code Set (encoding)
1293 	 *
1294 	 * from spc3r23.pdf Section 7.6.3.1 Table 296
1295 	 */
1296 	vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1297 	switch (vpd->device_identifier_code_set) {
1298 	case 0x01: /* Binary */
1299 		vpd->device_identifier[j++] =
1300 				hex_str[vpd->device_identifier_type];
1301 		while (i < (4 + page_83[3])) {
1302 			vpd->device_identifier[j++] =
1303 				hex_str[(page_83[i] & 0xf0) >> 4];
1304 			vpd->device_identifier[j++] =
1305 				hex_str[page_83[i] & 0x0f];
1306 			i++;
1307 		}
1308 		break;
1309 	case 0x02: /* ASCII */
1310 	case 0x03: /* UTF-8 */
1311 		while (i < (4 + page_83[3]))
1312 			vpd->device_identifier[j++] = page_83[i++];
1313 		break;
1314 	default:
1315 		break;
1316 	}
1317 
1318 	return transport_dump_vpd_ident(vpd, NULL, 0);
1319 }
1320 EXPORT_SYMBOL(transport_set_vpd_ident);
1321 
1322 static sense_reason_t
1323 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1324 			       unsigned int size)
1325 {
1326 	u32 mtl;
1327 
1328 	if (!cmd->se_tfo->max_data_sg_nents)
1329 		return TCM_NO_SENSE;
1330 	/*
1331 	 * Check if fabric enforced maximum SGL entries per I/O descriptor
1332 	 * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1333 	 * residual_count and reduce original cmd->data_length to maximum
1334 	 * length based on single PAGE_SIZE entry scatter-lists.
1335 	 */
1336 	mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1337 	if (cmd->data_length > mtl) {
1338 		/*
1339 		 * If an existing CDB overflow is present, calculate new residual
1340 		 * based on CDB size minus fabric maximum transfer length.
1341 		 *
1342 		 * If an existing CDB underflow is present, calculate new residual
1343 		 * based on original cmd->data_length minus fabric maximum transfer
1344 		 * length.
1345 		 *
1346 		 * Otherwise, set the underflow residual based on cmd->data_length
1347 		 * minus fabric maximum transfer length.
1348 		 */
1349 		if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1350 			cmd->residual_count = (size - mtl);
1351 		} else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1352 			u32 orig_dl = size + cmd->residual_count;
1353 			cmd->residual_count = (orig_dl - mtl);
1354 		} else {
1355 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1356 			cmd->residual_count = (cmd->data_length - mtl);
1357 		}
1358 		cmd->data_length = mtl;
1359 		/*
1360 		 * Reset sbc_check_prot() calculated protection payload
1361 		 * length based upon the new smaller MTL.
1362 		 */
1363 		if (cmd->prot_length) {
1364 			u32 sectors = (mtl / dev->dev_attrib.block_size);
1365 			cmd->prot_length = dev->prot_length * sectors;
1366 		}
1367 	}
1368 	return TCM_NO_SENSE;
1369 }
1370 
1371 /**
1372  * target_cmd_size_check - Check whether there will be a residual.
1373  * @cmd: SCSI command.
1374  * @size: Data buffer size derived from CDB. The data buffer size provided by
1375  *   the SCSI transport driver is available in @cmd->data_length.
1376  *
1377  * Compare the data buffer size from the CDB with the data buffer limit from the transport
1378  * header. Set @cmd->residual_count and SCF_OVERFLOW_BIT or SCF_UNDERFLOW_BIT if necessary.
1379  *
1380  * Note: target drivers set @cmd->data_length by calling __target_init_cmd().
1381  *
1382  * Return: TCM_NO_SENSE
1383  */
1384 sense_reason_t
1385 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1386 {
1387 	struct se_device *dev = cmd->se_dev;
1388 
1389 	if (cmd->unknown_data_length) {
1390 		cmd->data_length = size;
1391 	} else if (size != cmd->data_length) {
1392 		pr_warn_ratelimited("TARGET_CORE[%s]: Expected Transfer Length:"
1393 			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
1394 			" 0x%02x\n", cmd->se_tfo->fabric_name,
1395 				cmd->data_length, size, cmd->t_task_cdb[0]);
1396 		/*
1397 		 * For READ command for the overflow case keep the existing
1398 		 * fabric provided ->data_length. Otherwise for the underflow
1399 		 * case, reset ->data_length to the smaller SCSI expected data
1400 		 * transfer length.
1401 		 */
1402 		if (size > cmd->data_length) {
1403 			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1404 			cmd->residual_count = (size - cmd->data_length);
1405 		} else {
1406 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1407 			cmd->residual_count = (cmd->data_length - size);
1408 			/*
1409 			 * Do not truncate ->data_length for WRITE command to
1410 			 * dump all payload
1411 			 */
1412 			if (cmd->data_direction == DMA_FROM_DEVICE) {
1413 				cmd->data_length = size;
1414 			}
1415 		}
1416 
1417 		if (cmd->data_direction == DMA_TO_DEVICE) {
1418 			if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1419 				pr_err_ratelimited("Rejecting underflow/overflow"
1420 						   " for WRITE data CDB\n");
1421 				return TCM_INVALID_FIELD_IN_COMMAND_IU;
1422 			}
1423 			/*
1424 			 * Some fabric drivers like iscsi-target still expect to
1425 			 * always reject overflow writes.  Reject this case until
1426 			 * full fabric driver level support for overflow writes
1427 			 * is introduced tree-wide.
1428 			 */
1429 			if (size > cmd->data_length) {
1430 				pr_err_ratelimited("Rejecting overflow for"
1431 						   " WRITE control CDB\n");
1432 				return TCM_INVALID_CDB_FIELD;
1433 			}
1434 		}
1435 	}
1436 
1437 	return target_check_max_data_sg_nents(cmd, dev, size);
1438 
1439 }
1440 
1441 /*
1442  * Used by fabric modules containing a local struct se_cmd within their
1443  * fabric dependent per I/O descriptor.
1444  *
1445  * Preserves the value of @cmd->tag.
1446  */
1447 void __target_init_cmd(struct se_cmd *cmd,
1448 		       const struct target_core_fabric_ops *tfo,
1449 		       struct se_session *se_sess, u32 data_length,
1450 		       int data_direction, int task_attr,
1451 		       unsigned char *sense_buffer, u64 unpacked_lun,
1452 		       struct target_cmd_counter *cmd_cnt)
1453 {
1454 	INIT_LIST_HEAD(&cmd->se_delayed_node);
1455 	INIT_LIST_HEAD(&cmd->se_qf_node);
1456 	INIT_LIST_HEAD(&cmd->state_list);
1457 	init_completion(&cmd->t_transport_stop_comp);
1458 	cmd->free_compl = NULL;
1459 	cmd->abrt_compl = NULL;
1460 	spin_lock_init(&cmd->t_state_lock);
1461 	INIT_WORK(&cmd->work, NULL);
1462 	kref_init(&cmd->cmd_kref);
1463 
1464 	cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1465 	cmd->se_tfo = tfo;
1466 	cmd->se_sess = se_sess;
1467 	cmd->data_length = data_length;
1468 	cmd->data_direction = data_direction;
1469 	cmd->sam_task_attr = task_attr;
1470 	cmd->sense_buffer = sense_buffer;
1471 	cmd->orig_fe_lun = unpacked_lun;
1472 	cmd->cmd_cnt = cmd_cnt;
1473 
1474 	if (!(cmd->se_cmd_flags & SCF_USE_CPUID))
1475 		cmd->cpuid = raw_smp_processor_id();
1476 
1477 	cmd->state_active = false;
1478 }
1479 EXPORT_SYMBOL(__target_init_cmd);
1480 
1481 static sense_reason_t
1482 transport_check_alloc_task_attr(struct se_cmd *cmd)
1483 {
1484 	struct se_device *dev = cmd->se_dev;
1485 
1486 	/*
1487 	 * Check if SAM Task Attribute emulation is enabled for this
1488 	 * struct se_device storage object
1489 	 */
1490 	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1491 		return 0;
1492 
1493 	if (cmd->sam_task_attr == TCM_ACA_TAG) {
1494 		pr_debug("SAM Task Attribute ACA"
1495 			" emulation is not supported\n");
1496 		return TCM_INVALID_CDB_FIELD;
1497 	}
1498 
1499 	return 0;
1500 }
1501 
1502 sense_reason_t
1503 target_cmd_init_cdb(struct se_cmd *cmd, unsigned char *cdb, gfp_t gfp)
1504 {
1505 	sense_reason_t ret;
1506 
1507 	/*
1508 	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1509 	 * for VARIABLE_LENGTH_CMD
1510 	 */
1511 	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1512 		pr_err("Received SCSI CDB with command_size: %d that"
1513 			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1514 			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1515 		ret = TCM_INVALID_CDB_FIELD;
1516 		goto err;
1517 	}
1518 	/*
1519 	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1520 	 * allocate the additional extended CDB buffer now..  Otherwise
1521 	 * setup the pointer from __t_task_cdb to t_task_cdb.
1522 	 */
1523 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1524 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb), gfp);
1525 		if (!cmd->t_task_cdb) {
1526 			pr_err("Unable to allocate cmd->t_task_cdb"
1527 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1528 				scsi_command_size(cdb),
1529 				(unsigned long)sizeof(cmd->__t_task_cdb));
1530 			ret = TCM_OUT_OF_RESOURCES;
1531 			goto err;
1532 		}
1533 	}
1534 	/*
1535 	 * Copy the original CDB into cmd->
1536 	 */
1537 	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1538 
1539 	trace_target_sequencer_start(cmd);
1540 	return 0;
1541 
1542 err:
1543 	/*
1544 	 * Copy the CDB here to allow trace_target_cmd_complete() to
1545 	 * print the cdb to the trace buffers.
1546 	 */
1547 	memcpy(cmd->t_task_cdb, cdb, min(scsi_command_size(cdb),
1548 					 (unsigned int)TCM_MAX_COMMAND_SIZE));
1549 	return ret;
1550 }
1551 EXPORT_SYMBOL(target_cmd_init_cdb);
1552 
1553 sense_reason_t
1554 target_cmd_parse_cdb(struct se_cmd *cmd)
1555 {
1556 	struct se_device *dev = cmd->se_dev;
1557 	sense_reason_t ret;
1558 
1559 	ret = dev->transport->parse_cdb(cmd);
1560 	if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1561 		pr_debug_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1562 				     cmd->se_tfo->fabric_name,
1563 				     cmd->se_sess->se_node_acl->initiatorname,
1564 				     cmd->t_task_cdb[0]);
1565 	if (ret)
1566 		return ret;
1567 
1568 	ret = transport_check_alloc_task_attr(cmd);
1569 	if (ret)
1570 		return ret;
1571 
1572 	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1573 	atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1574 	return 0;
1575 }
1576 EXPORT_SYMBOL(target_cmd_parse_cdb);
1577 
1578 static int __target_submit(struct se_cmd *cmd)
1579 {
1580 	sense_reason_t ret;
1581 
1582 	might_sleep();
1583 
1584 	/*
1585 	 * Check if we need to delay processing because of ALUA
1586 	 * Active/NonOptimized primary access state..
1587 	 */
1588 	core_alua_check_nonop_delay(cmd);
1589 
1590 	if (cmd->t_data_nents != 0) {
1591 		/*
1592 		 * This is primarily a hack for udev and tcm loop which sends
1593 		 * INQUIRYs with a single page and expects the data to be
1594 		 * cleared.
1595 		 */
1596 		if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1597 		    cmd->data_direction == DMA_FROM_DEVICE) {
1598 			struct scatterlist *sgl = cmd->t_data_sg;
1599 			unsigned char *buf = NULL;
1600 
1601 			BUG_ON(!sgl);
1602 
1603 			buf = kmap_local_page(sg_page(sgl));
1604 			if (buf) {
1605 				memset(buf + sgl->offset, 0, sgl->length);
1606 				kunmap_local(buf);
1607 			}
1608 		}
1609 	}
1610 
1611 	if (!cmd->se_lun) {
1612 		dump_stack();
1613 		pr_err("cmd->se_lun is NULL\n");
1614 		return -EINVAL;
1615 	}
1616 
1617 	/*
1618 	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1619 	 * outstanding descriptors are handled correctly during shutdown via
1620 	 * transport_wait_for_tasks()
1621 	 *
1622 	 * Also, we don't take cmd->t_state_lock here as we only expect
1623 	 * this to be called for initial descriptor submission.
1624 	 */
1625 	cmd->t_state = TRANSPORT_NEW_CMD;
1626 	cmd->transport_state |= CMD_T_ACTIVE;
1627 
1628 	/*
1629 	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1630 	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1631 	 * and call transport_generic_request_failure() if necessary..
1632 	 */
1633 	ret = transport_generic_new_cmd(cmd);
1634 	if (ret)
1635 		transport_generic_request_failure(cmd, ret);
1636 	return 0;
1637 }
1638 
1639 sense_reason_t
1640 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1641 		u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1642 {
1643 	if (!sgl || !sgl_count)
1644 		return 0;
1645 
1646 	/*
1647 	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1648 	 * scatterlists already have been set to follow what the fabric
1649 	 * passes for the original expected data transfer length.
1650 	 */
1651 	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1652 		pr_warn("Rejecting SCSI DATA overflow for fabric using"
1653 			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1654 		return TCM_INVALID_CDB_FIELD;
1655 	}
1656 
1657 	cmd->t_data_sg = sgl;
1658 	cmd->t_data_nents = sgl_count;
1659 	cmd->t_bidi_data_sg = sgl_bidi;
1660 	cmd->t_bidi_data_nents = sgl_bidi_count;
1661 
1662 	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1663 	return 0;
1664 }
1665 
1666 /**
1667  * target_init_cmd - initialize se_cmd
1668  * @se_cmd: command descriptor to init
1669  * @se_sess: associated se_sess for endpoint
1670  * @sense: pointer to SCSI sense buffer
1671  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1672  * @data_length: fabric expected data transfer length
1673  * @task_attr: SAM task attribute
1674  * @data_dir: DMA data direction
1675  * @flags: flags for command submission from target_sc_flags_tables
1676  *
1677  * Task tags are supported if the caller has set @se_cmd->tag.
1678  *
1679  * Returns:
1680  *	- less than zero to signal active I/O shutdown failure.
1681  *	- zero on success.
1682  *
1683  * If the fabric driver calls target_stop_session, then it must check the
1684  * return code and handle failures. This will never fail for other drivers,
1685  * and the return code can be ignored.
1686  */
1687 int target_init_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1688 		    unsigned char *sense, u64 unpacked_lun,
1689 		    u32 data_length, int task_attr, int data_dir, int flags)
1690 {
1691 	struct se_portal_group *se_tpg;
1692 
1693 	se_tpg = se_sess->se_tpg;
1694 	BUG_ON(!se_tpg);
1695 	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1696 
1697 	if (flags & TARGET_SCF_USE_CPUID)
1698 		se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1699 	/*
1700 	 * Signal bidirectional data payloads to target-core
1701 	 */
1702 	if (flags & TARGET_SCF_BIDI_OP)
1703 		se_cmd->se_cmd_flags |= SCF_BIDI;
1704 
1705 	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1706 		se_cmd->unknown_data_length = 1;
1707 	/*
1708 	 * Initialize se_cmd for target operation.  From this point
1709 	 * exceptions are handled by sending exception status via
1710 	 * target_core_fabric_ops->queue_status() callback
1711 	 */
1712 	__target_init_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, data_length,
1713 			  data_dir, task_attr, sense, unpacked_lun,
1714 			  se_sess->cmd_cnt);
1715 
1716 	/*
1717 	 * Obtain struct se_cmd->cmd_kref reference. A second kref_get here is
1718 	 * necessary for fabrics using TARGET_SCF_ACK_KREF that expect a second
1719 	 * kref_put() to happen during fabric packet acknowledgement.
1720 	 */
1721 	return target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1722 }
1723 EXPORT_SYMBOL_GPL(target_init_cmd);
1724 
1725 /**
1726  * target_submit_prep - prepare cmd for submission
1727  * @se_cmd: command descriptor to prep
1728  * @cdb: pointer to SCSI CDB
1729  * @sgl: struct scatterlist memory for unidirectional mapping
1730  * @sgl_count: scatterlist count for unidirectional mapping
1731  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1732  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1733  * @sgl_prot: struct scatterlist memory protection information
1734  * @sgl_prot_count: scatterlist count for protection information
1735  * @gfp: gfp allocation type
1736  *
1737  * Returns:
1738  *	- less than zero to signal failure.
1739  *	- zero on success.
1740  *
1741  * If failure is returned, lio will the callers queue_status to complete
1742  * the cmd.
1743  */
1744 int target_submit_prep(struct se_cmd *se_cmd, unsigned char *cdb,
1745 		       struct scatterlist *sgl, u32 sgl_count,
1746 		       struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1747 		       struct scatterlist *sgl_prot, u32 sgl_prot_count,
1748 		       gfp_t gfp)
1749 {
1750 	sense_reason_t rc;
1751 
1752 	rc = target_cmd_init_cdb(se_cmd, cdb, gfp);
1753 	if (rc)
1754 		goto send_cc_direct;
1755 
1756 	/*
1757 	 * Locate se_lun pointer and attach it to struct se_cmd
1758 	 */
1759 	rc = transport_lookup_cmd_lun(se_cmd);
1760 	if (rc)
1761 		goto send_cc_direct;
1762 
1763 	rc = target_cmd_parse_cdb(se_cmd);
1764 	if (rc != 0)
1765 		goto generic_fail;
1766 
1767 	/*
1768 	 * Save pointers for SGLs containing protection information,
1769 	 * if present.
1770 	 */
1771 	if (sgl_prot_count) {
1772 		se_cmd->t_prot_sg = sgl_prot;
1773 		se_cmd->t_prot_nents = sgl_prot_count;
1774 		se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1775 	}
1776 
1777 	/*
1778 	 * When a non zero sgl_count has been passed perform SGL passthrough
1779 	 * mapping for pre-allocated fabric memory instead of having target
1780 	 * core perform an internal SGL allocation..
1781 	 */
1782 	if (sgl_count != 0) {
1783 		BUG_ON(!sgl);
1784 
1785 		rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1786 				sgl_bidi, sgl_bidi_count);
1787 		if (rc != 0)
1788 			goto generic_fail;
1789 	}
1790 
1791 	return 0;
1792 
1793 send_cc_direct:
1794 	transport_send_check_condition_and_sense(se_cmd, rc, 0);
1795 	target_put_sess_cmd(se_cmd);
1796 	return -EIO;
1797 
1798 generic_fail:
1799 	transport_generic_request_failure(se_cmd, rc);
1800 	return -EIO;
1801 }
1802 EXPORT_SYMBOL_GPL(target_submit_prep);
1803 
1804 /**
1805  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1806  *
1807  * @se_cmd: command descriptor to submit
1808  * @se_sess: associated se_sess for endpoint
1809  * @cdb: pointer to SCSI CDB
1810  * @sense: pointer to SCSI sense buffer
1811  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1812  * @data_length: fabric expected data transfer length
1813  * @task_attr: SAM task attribute
1814  * @data_dir: DMA data direction
1815  * @flags: flags for command submission from target_sc_flags_tables
1816  *
1817  * Task tags are supported if the caller has set @se_cmd->tag.
1818  *
1819  * This may only be called from process context, and also currently
1820  * assumes internal allocation of fabric payload buffer by target-core.
1821  *
1822  * It also assumes interal target core SGL memory allocation.
1823  *
1824  * This function must only be used by drivers that do their own
1825  * sync during shutdown and does not use target_stop_session. If there
1826  * is a failure this function will call into the fabric driver's
1827  * queue_status with a CHECK_CONDITION.
1828  */
1829 void target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1830 		unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1831 		u32 data_length, int task_attr, int data_dir, int flags)
1832 {
1833 	int rc;
1834 
1835 	rc = target_init_cmd(se_cmd, se_sess, sense, unpacked_lun, data_length,
1836 			     task_attr, data_dir, flags);
1837 	WARN(rc, "Invalid target_submit_cmd use. Driver must not use target_stop_session or call target_init_cmd directly.\n");
1838 	if (rc)
1839 		return;
1840 
1841 	if (target_submit_prep(se_cmd, cdb, NULL, 0, NULL, 0, NULL, 0,
1842 			       GFP_KERNEL))
1843 		return;
1844 
1845 	target_submit(se_cmd);
1846 }
1847 EXPORT_SYMBOL(target_submit_cmd);
1848 
1849 
1850 static struct se_dev_plug *target_plug_device(struct se_device *se_dev)
1851 {
1852 	struct se_dev_plug *se_plug;
1853 
1854 	if (!se_dev->transport->plug_device)
1855 		return NULL;
1856 
1857 	se_plug = se_dev->transport->plug_device(se_dev);
1858 	if (!se_plug)
1859 		return NULL;
1860 
1861 	se_plug->se_dev = se_dev;
1862 	/*
1863 	 * We have a ref to the lun at this point, but the cmds could
1864 	 * complete before we unplug, so grab a ref to the se_device so we
1865 	 * can call back into the backend.
1866 	 */
1867 	config_group_get(&se_dev->dev_group);
1868 	return se_plug;
1869 }
1870 
1871 static void target_unplug_device(struct se_dev_plug *se_plug)
1872 {
1873 	struct se_device *se_dev = se_plug->se_dev;
1874 
1875 	se_dev->transport->unplug_device(se_plug);
1876 	config_group_put(&se_dev->dev_group);
1877 }
1878 
1879 void target_queued_submit_work(struct work_struct *work)
1880 {
1881 	struct se_cmd_queue *sq = container_of(work, struct se_cmd_queue, work);
1882 	struct se_cmd *se_cmd, *next_cmd;
1883 	struct se_dev_plug *se_plug = NULL;
1884 	struct se_device *se_dev = NULL;
1885 	struct llist_node *cmd_list;
1886 
1887 	cmd_list = llist_del_all(&sq->cmd_list);
1888 	if (!cmd_list)
1889 		/* Previous call took what we were queued to submit */
1890 		return;
1891 
1892 	cmd_list = llist_reverse_order(cmd_list);
1893 	llist_for_each_entry_safe(se_cmd, next_cmd, cmd_list, se_cmd_list) {
1894 		if (!se_dev) {
1895 			se_dev = se_cmd->se_dev;
1896 			se_plug = target_plug_device(se_dev);
1897 		}
1898 
1899 		__target_submit(se_cmd);
1900 	}
1901 
1902 	if (se_plug)
1903 		target_unplug_device(se_plug);
1904 }
1905 
1906 /**
1907  * target_queue_submission - queue the cmd to run on the LIO workqueue
1908  * @se_cmd: command descriptor to submit
1909  */
1910 void target_queue_submission(struct se_cmd *se_cmd)
1911 {
1912 	struct se_device *se_dev = se_cmd->se_dev;
1913 	int cpu = se_cmd->cpuid;
1914 	struct se_cmd_queue *sq;
1915 
1916 	sq = &se_dev->queues[cpu].sq;
1917 	llist_add(&se_cmd->se_cmd_list, &sq->cmd_list);
1918 	queue_work_on(cpu, target_submission_wq, &sq->work);
1919 }
1920 EXPORT_SYMBOL_GPL(target_queue_submission);
1921 
1922 /**
1923  * target_submit - perform final initialization and submit cmd to LIO core
1924  * @cmd: command descriptor to submit
1925  *
1926  * target_submit_prep or something similar must have been called on the cmd,
1927  * and this must be called from process context.
1928  */
1929 int target_submit(struct se_cmd *se_cmd)
1930 {
1931 	const struct target_core_fabric_ops *tfo = se_cmd->se_sess->se_tpg->se_tpg_tfo;
1932 	struct se_dev_attrib *da = &se_cmd->se_dev->dev_attrib;
1933 	u8 submit_type;
1934 
1935 	if (da->submit_type == TARGET_FABRIC_DEFAULT_SUBMIT)
1936 		submit_type = tfo->default_submit_type;
1937 	else if (da->submit_type == TARGET_DIRECT_SUBMIT &&
1938 		 tfo->direct_submit_supp)
1939 		submit_type = TARGET_DIRECT_SUBMIT;
1940 	else
1941 		submit_type = TARGET_QUEUE_SUBMIT;
1942 
1943 	if (submit_type == TARGET_DIRECT_SUBMIT)
1944 		return __target_submit(se_cmd);
1945 
1946 	target_queue_submission(se_cmd);
1947 	return 0;
1948 }
1949 EXPORT_SYMBOL_GPL(target_submit);
1950 
1951 static void target_complete_tmr_failure(struct work_struct *work)
1952 {
1953 	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1954 
1955 	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1956 	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1957 
1958 	transport_lun_remove_cmd(se_cmd);
1959 	transport_cmd_check_stop_to_fabric(se_cmd);
1960 }
1961 
1962 /**
1963  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1964  *                     for TMR CDBs
1965  *
1966  * @se_cmd: command descriptor to submit
1967  * @se_sess: associated se_sess for endpoint
1968  * @sense: pointer to SCSI sense buffer
1969  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1970  * @fabric_tmr_ptr: fabric context for TMR req
1971  * @tm_type: Type of TM request
1972  * @gfp: gfp type for caller
1973  * @tag: referenced task tag for TMR_ABORT_TASK
1974  * @flags: submit cmd flags
1975  *
1976  * Callable from all contexts.
1977  **/
1978 
1979 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1980 		unsigned char *sense, u64 unpacked_lun,
1981 		void *fabric_tmr_ptr, unsigned char tm_type,
1982 		gfp_t gfp, u64 tag, int flags)
1983 {
1984 	struct se_portal_group *se_tpg;
1985 	int ret;
1986 
1987 	se_tpg = se_sess->se_tpg;
1988 	BUG_ON(!se_tpg);
1989 
1990 	__target_init_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1991 			  0, DMA_NONE, TCM_SIMPLE_TAG, sense, unpacked_lun,
1992 			  se_sess->cmd_cnt);
1993 	/*
1994 	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1995 	 * allocation failure.
1996 	 */
1997 	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1998 	if (ret < 0)
1999 		return -ENOMEM;
2000 
2001 	if (tm_type == TMR_ABORT_TASK)
2002 		se_cmd->se_tmr_req->ref_task_tag = tag;
2003 
2004 	/* See target_submit_cmd for commentary */
2005 	ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
2006 	if (ret) {
2007 		core_tmr_release_req(se_cmd->se_tmr_req);
2008 		return ret;
2009 	}
2010 
2011 	ret = transport_lookup_tmr_lun(se_cmd);
2012 	if (ret)
2013 		goto failure;
2014 
2015 	transport_generic_handle_tmr(se_cmd);
2016 	return 0;
2017 
2018 	/*
2019 	 * For callback during failure handling, push this work off
2020 	 * to process context with TMR_LUN_DOES_NOT_EXIST status.
2021 	 */
2022 failure:
2023 	INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
2024 	schedule_work(&se_cmd->work);
2025 	return 0;
2026 }
2027 EXPORT_SYMBOL(target_submit_tmr);
2028 
2029 /*
2030  * Handle SAM-esque emulation for generic transport request failures.
2031  */
2032 void transport_generic_request_failure(struct se_cmd *cmd,
2033 		sense_reason_t sense_reason)
2034 {
2035 	int ret = 0, post_ret;
2036 
2037 	pr_debug("-----[ Storage Engine Exception; sense_reason %d\n",
2038 		 sense_reason);
2039 	target_show_cmd("-----[ ", cmd);
2040 
2041 	/*
2042 	 * For SAM Task Attribute emulation for failed struct se_cmd
2043 	 */
2044 	transport_complete_task_attr(cmd);
2045 
2046 	if (cmd->transport_complete_callback)
2047 		cmd->transport_complete_callback(cmd, false, &post_ret);
2048 
2049 	if (cmd->transport_state & CMD_T_ABORTED) {
2050 		INIT_WORK(&cmd->work, target_abort_work);
2051 		queue_work(target_completion_wq, &cmd->work);
2052 		return;
2053 	}
2054 
2055 	switch (sense_reason) {
2056 	case TCM_NON_EXISTENT_LUN:
2057 	case TCM_UNSUPPORTED_SCSI_OPCODE:
2058 	case TCM_INVALID_CDB_FIELD:
2059 	case TCM_INVALID_PARAMETER_LIST:
2060 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
2061 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
2062 	case TCM_UNKNOWN_MODE_PAGE:
2063 	case TCM_WRITE_PROTECTED:
2064 	case TCM_ADDRESS_OUT_OF_RANGE:
2065 	case TCM_CHECK_CONDITION_ABORT_CMD:
2066 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2067 	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
2068 	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
2069 	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
2070 	case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
2071 	case TCM_TOO_MANY_TARGET_DESCS:
2072 	case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
2073 	case TCM_TOO_MANY_SEGMENT_DESCS:
2074 	case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
2075 	case TCM_INVALID_FIELD_IN_COMMAND_IU:
2076 	case TCM_ALUA_TG_PT_STANDBY:
2077 	case TCM_ALUA_TG_PT_UNAVAILABLE:
2078 	case TCM_ALUA_STATE_TRANSITION:
2079 	case TCM_ALUA_OFFLINE:
2080 		break;
2081 	case TCM_OUT_OF_RESOURCES:
2082 		cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
2083 		goto queue_status;
2084 	case TCM_LUN_BUSY:
2085 		cmd->scsi_status = SAM_STAT_BUSY;
2086 		goto queue_status;
2087 	case TCM_RESERVATION_CONFLICT:
2088 		/*
2089 		 * No SENSE Data payload for this case, set SCSI Status
2090 		 * and queue the response to $FABRIC_MOD.
2091 		 *
2092 		 * Uses linux/include/scsi/scsi.h SAM status codes defs
2093 		 */
2094 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
2095 		/*
2096 		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
2097 		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
2098 		 * CONFLICT STATUS.
2099 		 *
2100 		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
2101 		 */
2102 		if (cmd->se_sess &&
2103 		    cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl
2104 					== TARGET_UA_INTLCK_CTRL_ESTABLISH_UA) {
2105 			target_ua_allocate_lun(cmd->se_sess->se_node_acl,
2106 					       cmd->orig_fe_lun, 0x2C,
2107 					ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
2108 		}
2109 
2110 		goto queue_status;
2111 	default:
2112 		pr_err("Unknown transport error for CDB 0x%02x: %d\n",
2113 			cmd->t_task_cdb[0], sense_reason);
2114 		sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
2115 		break;
2116 	}
2117 
2118 	ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
2119 	if (ret)
2120 		goto queue_full;
2121 
2122 check_stop:
2123 	transport_lun_remove_cmd(cmd);
2124 	transport_cmd_check_stop_to_fabric(cmd);
2125 	return;
2126 
2127 queue_status:
2128 	trace_target_cmd_complete(cmd);
2129 	ret = cmd->se_tfo->queue_status(cmd);
2130 	if (!ret)
2131 		goto check_stop;
2132 queue_full:
2133 	transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2134 }
2135 EXPORT_SYMBOL(transport_generic_request_failure);
2136 
2137 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
2138 {
2139 	sense_reason_t ret;
2140 
2141 	if (!cmd->execute_cmd) {
2142 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2143 		goto err;
2144 	}
2145 	if (do_checks) {
2146 		/*
2147 		 * Check for an existing UNIT ATTENTION condition after
2148 		 * target_handle_task_attr() has done SAM task attr
2149 		 * checking, and possibly have already defered execution
2150 		 * out to target_restart_delayed_cmds() context.
2151 		 */
2152 		ret = target_scsi3_ua_check(cmd);
2153 		if (ret)
2154 			goto err;
2155 
2156 		ret = target_alua_state_check(cmd);
2157 		if (ret)
2158 			goto err;
2159 
2160 		ret = target_check_reservation(cmd);
2161 		if (ret) {
2162 			cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
2163 			goto err;
2164 		}
2165 	}
2166 
2167 	ret = cmd->execute_cmd(cmd);
2168 	if (!ret)
2169 		return;
2170 err:
2171 	spin_lock_irq(&cmd->t_state_lock);
2172 	cmd->transport_state &= ~CMD_T_SENT;
2173 	spin_unlock_irq(&cmd->t_state_lock);
2174 
2175 	transport_generic_request_failure(cmd, ret);
2176 }
2177 
2178 static int target_write_prot_action(struct se_cmd *cmd)
2179 {
2180 	u32 sectors;
2181 	/*
2182 	 * Perform WRITE_INSERT of PI using software emulation when backend
2183 	 * device has PI enabled, if the transport has not already generated
2184 	 * PI using hardware WRITE_INSERT offload.
2185 	 */
2186 	switch (cmd->prot_op) {
2187 	case TARGET_PROT_DOUT_INSERT:
2188 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
2189 			sbc_dif_generate(cmd);
2190 		break;
2191 	case TARGET_PROT_DOUT_STRIP:
2192 		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
2193 			break;
2194 
2195 		sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
2196 		cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2197 					     sectors, 0, cmd->t_prot_sg, 0);
2198 		if (unlikely(cmd->pi_err)) {
2199 			spin_lock_irq(&cmd->t_state_lock);
2200 			cmd->transport_state &= ~CMD_T_SENT;
2201 			spin_unlock_irq(&cmd->t_state_lock);
2202 			transport_generic_request_failure(cmd, cmd->pi_err);
2203 			return -1;
2204 		}
2205 		break;
2206 	default:
2207 		break;
2208 	}
2209 
2210 	return 0;
2211 }
2212 
2213 static bool target_handle_task_attr(struct se_cmd *cmd)
2214 {
2215 	struct se_device *dev = cmd->se_dev;
2216 
2217 	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
2218 		return false;
2219 
2220 	cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
2221 
2222 	/*
2223 	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
2224 	 * to allow the passed struct se_cmd list of tasks to the front of the list.
2225 	 */
2226 	switch (cmd->sam_task_attr) {
2227 	case TCM_HEAD_TAG:
2228 		atomic_inc_mb(&dev->non_ordered);
2229 		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
2230 			 cmd->t_task_cdb[0]);
2231 		return false;
2232 	case TCM_ORDERED_TAG:
2233 		atomic_inc_mb(&dev->delayed_cmd_count);
2234 
2235 		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
2236 			 cmd->t_task_cdb[0]);
2237 		break;
2238 	default:
2239 		/*
2240 		 * For SIMPLE and UNTAGGED Task Attribute commands
2241 		 */
2242 		atomic_inc_mb(&dev->non_ordered);
2243 
2244 		if (atomic_read(&dev->delayed_cmd_count) == 0)
2245 			return false;
2246 		break;
2247 	}
2248 
2249 	if (cmd->sam_task_attr != TCM_ORDERED_TAG) {
2250 		atomic_inc_mb(&dev->delayed_cmd_count);
2251 		/*
2252 		 * We will account for this when we dequeue from the delayed
2253 		 * list.
2254 		 */
2255 		atomic_dec_mb(&dev->non_ordered);
2256 	}
2257 
2258 	spin_lock_irq(&cmd->t_state_lock);
2259 	cmd->transport_state &= ~CMD_T_SENT;
2260 	spin_unlock_irq(&cmd->t_state_lock);
2261 
2262 	spin_lock(&dev->delayed_cmd_lock);
2263 	list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
2264 	spin_unlock(&dev->delayed_cmd_lock);
2265 
2266 	pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
2267 		cmd->t_task_cdb[0], cmd->sam_task_attr);
2268 	/*
2269 	 * We may have no non ordered cmds when this function started or we
2270 	 * could have raced with the last simple/head cmd completing, so kick
2271 	 * the delayed handler here.
2272 	 */
2273 	schedule_work(&dev->delayed_cmd_work);
2274 	return true;
2275 }
2276 
2277 void target_execute_cmd(struct se_cmd *cmd)
2278 {
2279 	/*
2280 	 * Determine if frontend context caller is requesting the stopping of
2281 	 * this command for frontend exceptions.
2282 	 *
2283 	 * If the received CDB has already been aborted stop processing it here.
2284 	 */
2285 	if (target_cmd_interrupted(cmd))
2286 		return;
2287 
2288 	spin_lock_irq(&cmd->t_state_lock);
2289 	cmd->t_state = TRANSPORT_PROCESSING;
2290 	cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
2291 	spin_unlock_irq(&cmd->t_state_lock);
2292 
2293 	if (target_write_prot_action(cmd))
2294 		return;
2295 
2296 	if (target_handle_task_attr(cmd))
2297 		return;
2298 
2299 	__target_execute_cmd(cmd, true);
2300 }
2301 EXPORT_SYMBOL(target_execute_cmd);
2302 
2303 /*
2304  * Process all commands up to the last received ORDERED task attribute which
2305  * requires another blocking boundary
2306  */
2307 void target_do_delayed_work(struct work_struct *work)
2308 {
2309 	struct se_device *dev = container_of(work, struct se_device,
2310 					     delayed_cmd_work);
2311 
2312 	spin_lock(&dev->delayed_cmd_lock);
2313 	while (!dev->ordered_sync_in_progress) {
2314 		struct se_cmd *cmd;
2315 
2316 		if (list_empty(&dev->delayed_cmd_list))
2317 			break;
2318 
2319 		cmd = list_entry(dev->delayed_cmd_list.next,
2320 				 struct se_cmd, se_delayed_node);
2321 
2322 		if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
2323 			/*
2324 			 * Check if we started with:
2325 			 * [ordered] [simple] [ordered]
2326 			 * and we are now at the last ordered so we have to wait
2327 			 * for the simple cmd.
2328 			 */
2329 			if (atomic_read(&dev->non_ordered) > 0)
2330 				break;
2331 
2332 			dev->ordered_sync_in_progress = true;
2333 		}
2334 
2335 		list_del(&cmd->se_delayed_node);
2336 		atomic_dec_mb(&dev->delayed_cmd_count);
2337 		spin_unlock(&dev->delayed_cmd_lock);
2338 
2339 		if (cmd->sam_task_attr != TCM_ORDERED_TAG)
2340 			atomic_inc_mb(&dev->non_ordered);
2341 
2342 		cmd->transport_state |= CMD_T_SENT;
2343 
2344 		__target_execute_cmd(cmd, true);
2345 
2346 		spin_lock(&dev->delayed_cmd_lock);
2347 	}
2348 	spin_unlock(&dev->delayed_cmd_lock);
2349 }
2350 
2351 /*
2352  * Called from I/O completion to determine which dormant/delayed
2353  * and ordered cmds need to have their tasks added to the execution queue.
2354  */
2355 static void transport_complete_task_attr(struct se_cmd *cmd)
2356 {
2357 	struct se_device *dev = cmd->se_dev;
2358 
2359 	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
2360 		return;
2361 
2362 	if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
2363 		goto restart;
2364 
2365 	if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
2366 		atomic_dec_mb(&dev->non_ordered);
2367 		dev->dev_cur_ordered_id++;
2368 	} else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
2369 		atomic_dec_mb(&dev->non_ordered);
2370 		dev->dev_cur_ordered_id++;
2371 		pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
2372 			 dev->dev_cur_ordered_id);
2373 	} else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
2374 		spin_lock(&dev->delayed_cmd_lock);
2375 		dev->ordered_sync_in_progress = false;
2376 		spin_unlock(&dev->delayed_cmd_lock);
2377 
2378 		dev->dev_cur_ordered_id++;
2379 		pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
2380 			 dev->dev_cur_ordered_id);
2381 	}
2382 	cmd->se_cmd_flags &= ~SCF_TASK_ATTR_SET;
2383 
2384 restart:
2385 	if (atomic_read(&dev->delayed_cmd_count) > 0)
2386 		schedule_work(&dev->delayed_cmd_work);
2387 }
2388 
2389 static void transport_complete_qf(struct se_cmd *cmd)
2390 {
2391 	int ret = 0;
2392 
2393 	transport_complete_task_attr(cmd);
2394 	/*
2395 	 * If a fabric driver ->write_pending() or ->queue_data_in() callback
2396 	 * has returned neither -ENOMEM or -EAGAIN, assume it's fatal and
2397 	 * the same callbacks should not be retried.  Return CHECK_CONDITION
2398 	 * if a scsi_status is not already set.
2399 	 *
2400 	 * If a fabric driver ->queue_status() has returned non zero, always
2401 	 * keep retrying no matter what..
2402 	 */
2403 	if (cmd->t_state == TRANSPORT_COMPLETE_QF_ERR) {
2404 		if (cmd->scsi_status)
2405 			goto queue_status;
2406 
2407 		translate_sense_reason(cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
2408 		goto queue_status;
2409 	}
2410 
2411 	/*
2412 	 * Check if we need to send a sense buffer from
2413 	 * the struct se_cmd in question. We do NOT want
2414 	 * to take this path of the IO has been marked as
2415 	 * needing to be treated like a "normal read". This
2416 	 * is the case if it's a tape read, and either the
2417 	 * FM, EOM, or ILI bits are set, but there is no
2418 	 * sense data.
2419 	 */
2420 	if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
2421 	    cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
2422 		goto queue_status;
2423 
2424 	switch (cmd->data_direction) {
2425 	case DMA_FROM_DEVICE:
2426 		/* queue status if not treating this as a normal read */
2427 		if (cmd->scsi_status &&
2428 		    !(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
2429 			goto queue_status;
2430 
2431 		trace_target_cmd_complete(cmd);
2432 		ret = cmd->se_tfo->queue_data_in(cmd);
2433 		break;
2434 	case DMA_TO_DEVICE:
2435 		if (cmd->se_cmd_flags & SCF_BIDI) {
2436 			ret = cmd->se_tfo->queue_data_in(cmd);
2437 			break;
2438 		}
2439 		fallthrough;
2440 	case DMA_NONE:
2441 queue_status:
2442 		trace_target_cmd_complete(cmd);
2443 		ret = cmd->se_tfo->queue_status(cmd);
2444 		break;
2445 	default:
2446 		break;
2447 	}
2448 
2449 	if (ret < 0) {
2450 		transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2451 		return;
2452 	}
2453 	transport_lun_remove_cmd(cmd);
2454 	transport_cmd_check_stop_to_fabric(cmd);
2455 }
2456 
2457 static void transport_handle_queue_full(struct se_cmd *cmd, struct se_device *dev,
2458 					int err, bool write_pending)
2459 {
2460 	/*
2461 	 * -EAGAIN or -ENOMEM signals retry of ->write_pending() and/or
2462 	 * ->queue_data_in() callbacks from new process context.
2463 	 *
2464 	 * Otherwise for other errors, transport_complete_qf() will send
2465 	 * CHECK_CONDITION via ->queue_status() instead of attempting to
2466 	 * retry associated fabric driver data-transfer callbacks.
2467 	 */
2468 	if (err == -EAGAIN || err == -ENOMEM) {
2469 		cmd->t_state = (write_pending) ? TRANSPORT_COMPLETE_QF_WP :
2470 						 TRANSPORT_COMPLETE_QF_OK;
2471 	} else {
2472 		pr_warn_ratelimited("Got unknown fabric queue status: %d\n", err);
2473 		cmd->t_state = TRANSPORT_COMPLETE_QF_ERR;
2474 	}
2475 
2476 	spin_lock_irq(&dev->qf_cmd_lock);
2477 	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2478 	atomic_inc_mb(&dev->dev_qf_count);
2479 	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2480 
2481 	schedule_work(&cmd->se_dev->qf_work_queue);
2482 }
2483 
2484 static bool target_read_prot_action(struct se_cmd *cmd)
2485 {
2486 	switch (cmd->prot_op) {
2487 	case TARGET_PROT_DIN_STRIP:
2488 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2489 			u32 sectors = cmd->data_length >>
2490 				  ilog2(cmd->se_dev->dev_attrib.block_size);
2491 
2492 			cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2493 						     sectors, 0, cmd->t_prot_sg,
2494 						     0);
2495 			if (cmd->pi_err)
2496 				return true;
2497 		}
2498 		break;
2499 	case TARGET_PROT_DIN_INSERT:
2500 		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2501 			break;
2502 
2503 		sbc_dif_generate(cmd);
2504 		break;
2505 	default:
2506 		break;
2507 	}
2508 
2509 	return false;
2510 }
2511 
2512 static void target_complete_ok_work(struct work_struct *work)
2513 {
2514 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2515 	int ret;
2516 
2517 	/*
2518 	 * Check if we need to move delayed/dormant tasks from cmds on the
2519 	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2520 	 * Attribute.
2521 	 */
2522 	transport_complete_task_attr(cmd);
2523 
2524 	/*
2525 	 * Check to schedule QUEUE_FULL work, or execute an existing
2526 	 * cmd->transport_qf_callback()
2527 	 */
2528 	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2529 		schedule_work(&cmd->se_dev->qf_work_queue);
2530 
2531 	/*
2532 	 * Check if we need to send a sense buffer from
2533 	 * the struct se_cmd in question. We do NOT want
2534 	 * to take this path of the IO has been marked as
2535 	 * needing to be treated like a "normal read". This
2536 	 * is the case if it's a tape read, and either the
2537 	 * FM, EOM, or ILI bits are set, but there is no
2538 	 * sense data.
2539 	 */
2540 	if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
2541 	    cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2542 		WARN_ON(!cmd->scsi_status);
2543 		ret = transport_send_check_condition_and_sense(
2544 					cmd, 0, 1);
2545 		if (ret)
2546 			goto queue_full;
2547 
2548 		transport_lun_remove_cmd(cmd);
2549 		transport_cmd_check_stop_to_fabric(cmd);
2550 		return;
2551 	}
2552 	/*
2553 	 * Check for a callback, used by amongst other things
2554 	 * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2555 	 */
2556 	if (cmd->transport_complete_callback) {
2557 		sense_reason_t rc;
2558 		bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2559 		bool zero_dl = !(cmd->data_length);
2560 		int post_ret = 0;
2561 
2562 		rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2563 		if (!rc && !post_ret) {
2564 			if (caw && zero_dl)
2565 				goto queue_rsp;
2566 
2567 			return;
2568 		} else if (rc) {
2569 			ret = transport_send_check_condition_and_sense(cmd,
2570 						rc, 0);
2571 			if (ret)
2572 				goto queue_full;
2573 
2574 			transport_lun_remove_cmd(cmd);
2575 			transport_cmd_check_stop_to_fabric(cmd);
2576 			return;
2577 		}
2578 	}
2579 
2580 queue_rsp:
2581 	switch (cmd->data_direction) {
2582 	case DMA_FROM_DEVICE:
2583 		/*
2584 		 * if this is a READ-type IO, but SCSI status
2585 		 * is set, then skip returning data and just
2586 		 * return the status -- unless this IO is marked
2587 		 * as needing to be treated as a normal read,
2588 		 * in which case we want to go ahead and return
2589 		 * the data. This happens, for example, for tape
2590 		 * reads with the FM, EOM, or ILI bits set, with
2591 		 * no sense data.
2592 		 */
2593 		if (cmd->scsi_status &&
2594 		    !(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
2595 			goto queue_status;
2596 
2597 		atomic_long_add(cmd->data_length,
2598 				&cmd->se_lun->lun_stats.tx_data_octets);
2599 		/*
2600 		 * Perform READ_STRIP of PI using software emulation when
2601 		 * backend had PI enabled, if the transport will not be
2602 		 * performing hardware READ_STRIP offload.
2603 		 */
2604 		if (target_read_prot_action(cmd)) {
2605 			ret = transport_send_check_condition_and_sense(cmd,
2606 						cmd->pi_err, 0);
2607 			if (ret)
2608 				goto queue_full;
2609 
2610 			transport_lun_remove_cmd(cmd);
2611 			transport_cmd_check_stop_to_fabric(cmd);
2612 			return;
2613 		}
2614 
2615 		trace_target_cmd_complete(cmd);
2616 		ret = cmd->se_tfo->queue_data_in(cmd);
2617 		if (ret)
2618 			goto queue_full;
2619 		break;
2620 	case DMA_TO_DEVICE:
2621 		atomic_long_add(cmd->data_length,
2622 				&cmd->se_lun->lun_stats.rx_data_octets);
2623 		/*
2624 		 * Check if we need to send READ payload for BIDI-COMMAND
2625 		 */
2626 		if (cmd->se_cmd_flags & SCF_BIDI) {
2627 			atomic_long_add(cmd->data_length,
2628 					&cmd->se_lun->lun_stats.tx_data_octets);
2629 			ret = cmd->se_tfo->queue_data_in(cmd);
2630 			if (ret)
2631 				goto queue_full;
2632 			break;
2633 		}
2634 		fallthrough;
2635 	case DMA_NONE:
2636 queue_status:
2637 		trace_target_cmd_complete(cmd);
2638 		ret = cmd->se_tfo->queue_status(cmd);
2639 		if (ret)
2640 			goto queue_full;
2641 		break;
2642 	default:
2643 		break;
2644 	}
2645 
2646 	transport_lun_remove_cmd(cmd);
2647 	transport_cmd_check_stop_to_fabric(cmd);
2648 	return;
2649 
2650 queue_full:
2651 	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2652 		" data_direction: %d\n", cmd, cmd->data_direction);
2653 
2654 	transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2655 }
2656 
2657 void target_free_sgl(struct scatterlist *sgl, int nents)
2658 {
2659 	sgl_free_n_order(sgl, nents, 0);
2660 }
2661 EXPORT_SYMBOL(target_free_sgl);
2662 
2663 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2664 {
2665 	/*
2666 	 * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2667 	 * emulation, and free + reset pointers if necessary..
2668 	 */
2669 	if (!cmd->t_data_sg_orig)
2670 		return;
2671 
2672 	kfree(cmd->t_data_sg);
2673 	cmd->t_data_sg = cmd->t_data_sg_orig;
2674 	cmd->t_data_sg_orig = NULL;
2675 	cmd->t_data_nents = cmd->t_data_nents_orig;
2676 	cmd->t_data_nents_orig = 0;
2677 }
2678 
2679 static inline void transport_free_pages(struct se_cmd *cmd)
2680 {
2681 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2682 		target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2683 		cmd->t_prot_sg = NULL;
2684 		cmd->t_prot_nents = 0;
2685 	}
2686 
2687 	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2688 		/*
2689 		 * Release special case READ buffer payload required for
2690 		 * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2691 		 */
2692 		if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2693 			target_free_sgl(cmd->t_bidi_data_sg,
2694 					   cmd->t_bidi_data_nents);
2695 			cmd->t_bidi_data_sg = NULL;
2696 			cmd->t_bidi_data_nents = 0;
2697 		}
2698 		transport_reset_sgl_orig(cmd);
2699 		return;
2700 	}
2701 	transport_reset_sgl_orig(cmd);
2702 
2703 	target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2704 	cmd->t_data_sg = NULL;
2705 	cmd->t_data_nents = 0;
2706 
2707 	target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2708 	cmd->t_bidi_data_sg = NULL;
2709 	cmd->t_bidi_data_nents = 0;
2710 }
2711 
2712 void *transport_kmap_data_sg(struct se_cmd *cmd)
2713 {
2714 	struct scatterlist *sg = cmd->t_data_sg;
2715 	struct page **pages;
2716 	int i;
2717 
2718 	/*
2719 	 * We need to take into account a possible offset here for fabrics like
2720 	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2721 	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2722 	 */
2723 	if (!cmd->t_data_nents)
2724 		return NULL;
2725 
2726 	BUG_ON(!sg);
2727 	if (cmd->t_data_nents == 1)
2728 		return kmap(sg_page(sg)) + sg->offset;
2729 
2730 	/* >1 page. use vmap */
2731 	pages = kmalloc_array(cmd->t_data_nents, sizeof(*pages), GFP_KERNEL);
2732 	if (!pages)
2733 		return NULL;
2734 
2735 	/* convert sg[] to pages[] */
2736 	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2737 		pages[i] = sg_page(sg);
2738 	}
2739 
2740 	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2741 	kfree(pages);
2742 	if (!cmd->t_data_vmap)
2743 		return NULL;
2744 
2745 	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2746 }
2747 EXPORT_SYMBOL(transport_kmap_data_sg);
2748 
2749 void transport_kunmap_data_sg(struct se_cmd *cmd)
2750 {
2751 	if (!cmd->t_data_nents) {
2752 		return;
2753 	} else if (cmd->t_data_nents == 1) {
2754 		kunmap(sg_page(cmd->t_data_sg));
2755 		return;
2756 	}
2757 
2758 	vunmap(cmd->t_data_vmap);
2759 	cmd->t_data_vmap = NULL;
2760 }
2761 EXPORT_SYMBOL(transport_kunmap_data_sg);
2762 
2763 int
2764 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2765 		 bool zero_page, bool chainable)
2766 {
2767 	gfp_t gfp = GFP_KERNEL | (zero_page ? __GFP_ZERO : 0);
2768 
2769 	*sgl = sgl_alloc_order(length, 0, chainable, gfp, nents);
2770 	return *sgl ? 0 : -ENOMEM;
2771 }
2772 EXPORT_SYMBOL(target_alloc_sgl);
2773 
2774 /*
2775  * Allocate any required resources to execute the command.  For writes we
2776  * might not have the payload yet, so notify the fabric via a call to
2777  * ->write_pending instead. Otherwise place it on the execution queue.
2778  */
2779 sense_reason_t
2780 transport_generic_new_cmd(struct se_cmd *cmd)
2781 {
2782 	unsigned long flags;
2783 	int ret = 0;
2784 	bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2785 
2786 	if (cmd->prot_op != TARGET_PROT_NORMAL &&
2787 	    !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2788 		ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2789 				       cmd->prot_length, true, false);
2790 		if (ret < 0)
2791 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2792 	}
2793 
2794 	/*
2795 	 * Determine if the TCM fabric module has already allocated physical
2796 	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2797 	 * beforehand.
2798 	 */
2799 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2800 	    cmd->data_length) {
2801 
2802 		if ((cmd->se_cmd_flags & SCF_BIDI) ||
2803 		    (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2804 			u32 bidi_length;
2805 
2806 			if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2807 				bidi_length = cmd->t_task_nolb *
2808 					      cmd->se_dev->dev_attrib.block_size;
2809 			else
2810 				bidi_length = cmd->data_length;
2811 
2812 			ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2813 					       &cmd->t_bidi_data_nents,
2814 					       bidi_length, zero_flag, false);
2815 			if (ret < 0)
2816 				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2817 		}
2818 
2819 		ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2820 				       cmd->data_length, zero_flag, false);
2821 		if (ret < 0)
2822 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2823 	} else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2824 		    cmd->data_length) {
2825 		/*
2826 		 * Special case for COMPARE_AND_WRITE with fabrics
2827 		 * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2828 		 */
2829 		u32 caw_length = cmd->t_task_nolb *
2830 				 cmd->se_dev->dev_attrib.block_size;
2831 
2832 		ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2833 				       &cmd->t_bidi_data_nents,
2834 				       caw_length, zero_flag, false);
2835 		if (ret < 0)
2836 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2837 	}
2838 	/*
2839 	 * If this command is not a write we can execute it right here,
2840 	 * for write buffers we need to notify the fabric driver first
2841 	 * and let it call back once the write buffers are ready.
2842 	 */
2843 	target_add_to_state_list(cmd);
2844 	if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2845 		target_execute_cmd(cmd);
2846 		return 0;
2847 	}
2848 
2849 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2850 	cmd->t_state = TRANSPORT_WRITE_PENDING;
2851 	/*
2852 	 * Determine if frontend context caller is requesting the stopping of
2853 	 * this command for frontend exceptions.
2854 	 */
2855 	if (cmd->transport_state & CMD_T_STOP &&
2856 	    !cmd->se_tfo->write_pending_must_be_called) {
2857 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
2858 			 __func__, __LINE__, cmd->tag);
2859 
2860 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2861 
2862 		complete_all(&cmd->t_transport_stop_comp);
2863 		return 0;
2864 	}
2865 	cmd->transport_state &= ~CMD_T_ACTIVE;
2866 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2867 
2868 	ret = cmd->se_tfo->write_pending(cmd);
2869 	if (ret)
2870 		goto queue_full;
2871 
2872 	return 0;
2873 
2874 queue_full:
2875 	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2876 	transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2877 	return 0;
2878 }
2879 EXPORT_SYMBOL(transport_generic_new_cmd);
2880 
2881 static void transport_write_pending_qf(struct se_cmd *cmd)
2882 {
2883 	unsigned long flags;
2884 	int ret;
2885 	bool stop;
2886 
2887 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2888 	stop = (cmd->transport_state & (CMD_T_STOP | CMD_T_ABORTED));
2889 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2890 
2891 	if (stop) {
2892 		pr_debug("%s:%d CMD_T_STOP|CMD_T_ABORTED for ITT: 0x%08llx\n",
2893 			__func__, __LINE__, cmd->tag);
2894 		complete_all(&cmd->t_transport_stop_comp);
2895 		return;
2896 	}
2897 
2898 	ret = cmd->se_tfo->write_pending(cmd);
2899 	if (ret) {
2900 		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2901 			 cmd);
2902 		transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2903 	}
2904 }
2905 
2906 static bool
2907 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2908 			   unsigned long *flags);
2909 
2910 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2911 {
2912 	unsigned long flags;
2913 
2914 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2915 	__transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2916 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2917 }
2918 
2919 /*
2920  * Call target_put_sess_cmd() and wait until target_release_cmd_kref(@cmd) has
2921  * finished.
2922  */
2923 void target_put_cmd_and_wait(struct se_cmd *cmd)
2924 {
2925 	DECLARE_COMPLETION_ONSTACK(compl);
2926 
2927 	WARN_ON_ONCE(cmd->abrt_compl);
2928 	cmd->abrt_compl = &compl;
2929 	target_put_sess_cmd(cmd);
2930 	wait_for_completion(&compl);
2931 }
2932 
2933 /*
2934  * This function is called by frontend drivers after processing of a command
2935  * has finished.
2936  *
2937  * The protocol for ensuring that either the regular frontend command
2938  * processing flow or target_handle_abort() code drops one reference is as
2939  * follows:
2940  * - Calling .queue_data_in(), .queue_status() or queue_tm_rsp() will cause
2941  *   the frontend driver to call this function synchronously or asynchronously.
2942  *   That will cause one reference to be dropped.
2943  * - During regular command processing the target core sets CMD_T_COMPLETE
2944  *   before invoking one of the .queue_*() functions.
2945  * - The code that aborts commands skips commands and TMFs for which
2946  *   CMD_T_COMPLETE has been set.
2947  * - CMD_T_ABORTED is set atomically after the CMD_T_COMPLETE check for
2948  *   commands that will be aborted.
2949  * - If the CMD_T_ABORTED flag is set but CMD_T_TAS has not been set
2950  *   transport_generic_free_cmd() skips its call to target_put_sess_cmd().
2951  * - For aborted commands for which CMD_T_TAS has been set .queue_status() will
2952  *   be called and will drop a reference.
2953  * - For aborted commands for which CMD_T_TAS has not been set .aborted_task()
2954  *   will be called. target_handle_abort() will drop the final reference.
2955  */
2956 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2957 {
2958 	DECLARE_COMPLETION_ONSTACK(compl);
2959 	int ret = 0;
2960 	bool aborted = false, tas = false;
2961 
2962 	if (wait_for_tasks)
2963 		target_wait_free_cmd(cmd, &aborted, &tas);
2964 
2965 	if (cmd->se_cmd_flags & SCF_SE_LUN_CMD) {
2966 		/*
2967 		 * Handle WRITE failure case where transport_generic_new_cmd()
2968 		 * has already added se_cmd to state_list, but fabric has
2969 		 * failed command before I/O submission.
2970 		 */
2971 		if (cmd->state_active)
2972 			target_remove_from_state_list(cmd);
2973 
2974 		if (cmd->se_lun)
2975 			transport_lun_remove_cmd(cmd);
2976 	}
2977 	if (aborted)
2978 		cmd->free_compl = &compl;
2979 	ret = target_put_sess_cmd(cmd);
2980 	if (aborted) {
2981 		pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2982 		wait_for_completion(&compl);
2983 		ret = 1;
2984 	}
2985 	return ret;
2986 }
2987 EXPORT_SYMBOL(transport_generic_free_cmd);
2988 
2989 /**
2990  * target_get_sess_cmd - Verify the session is accepting cmds and take ref
2991  * @se_cmd:	command descriptor to add
2992  * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
2993  */
2994 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2995 {
2996 	int ret = 0;
2997 
2998 	/*
2999 	 * Add a second kref if the fabric caller is expecting to handle
3000 	 * fabric acknowledgement that requires two target_put_sess_cmd()
3001 	 * invocations before se_cmd descriptor release.
3002 	 */
3003 	if (ack_kref) {
3004 		kref_get(&se_cmd->cmd_kref);
3005 		se_cmd->se_cmd_flags |= SCF_ACK_KREF;
3006 	}
3007 
3008 	/*
3009 	 * Users like xcopy do not use counters since they never do a stop
3010 	 * and wait.
3011 	 */
3012 	if (se_cmd->cmd_cnt) {
3013 		if (!percpu_ref_tryget_live(&se_cmd->cmd_cnt->refcnt))
3014 			ret = -ESHUTDOWN;
3015 	}
3016 	if (ret && ack_kref)
3017 		target_put_sess_cmd(se_cmd);
3018 
3019 	return ret;
3020 }
3021 EXPORT_SYMBOL(target_get_sess_cmd);
3022 
3023 static void target_free_cmd_mem(struct se_cmd *cmd)
3024 {
3025 	transport_free_pages(cmd);
3026 
3027 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
3028 		core_tmr_release_req(cmd->se_tmr_req);
3029 	if (cmd->t_task_cdb != cmd->__t_task_cdb)
3030 		kfree(cmd->t_task_cdb);
3031 }
3032 
3033 static void target_release_cmd_kref(struct kref *kref)
3034 {
3035 	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
3036 	struct target_cmd_counter *cmd_cnt = se_cmd->cmd_cnt;
3037 	struct completion *free_compl = se_cmd->free_compl;
3038 	struct completion *abrt_compl = se_cmd->abrt_compl;
3039 
3040 	target_free_cmd_mem(se_cmd);
3041 	se_cmd->se_tfo->release_cmd(se_cmd);
3042 	if (free_compl)
3043 		complete(free_compl);
3044 	if (abrt_compl)
3045 		complete(abrt_compl);
3046 
3047 	if (cmd_cnt)
3048 		percpu_ref_put(&cmd_cnt->refcnt);
3049 }
3050 
3051 /**
3052  * target_put_sess_cmd - decrease the command reference count
3053  * @se_cmd:	command to drop a reference from
3054  *
3055  * Returns 1 if and only if this target_put_sess_cmd() call caused the
3056  * refcount to drop to zero. Returns zero otherwise.
3057  */
3058 int target_put_sess_cmd(struct se_cmd *se_cmd)
3059 {
3060 	return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
3061 }
3062 EXPORT_SYMBOL(target_put_sess_cmd);
3063 
3064 static const char *data_dir_name(enum dma_data_direction d)
3065 {
3066 	switch (d) {
3067 	case DMA_BIDIRECTIONAL:	return "BIDI";
3068 	case DMA_TO_DEVICE:	return "WRITE";
3069 	case DMA_FROM_DEVICE:	return "READ";
3070 	case DMA_NONE:		return "NONE";
3071 	}
3072 
3073 	return "(?)";
3074 }
3075 
3076 static const char *cmd_state_name(enum transport_state_table t)
3077 {
3078 	switch (t) {
3079 	case TRANSPORT_NO_STATE:	return "NO_STATE";
3080 	case TRANSPORT_NEW_CMD:		return "NEW_CMD";
3081 	case TRANSPORT_WRITE_PENDING:	return "WRITE_PENDING";
3082 	case TRANSPORT_PROCESSING:	return "PROCESSING";
3083 	case TRANSPORT_COMPLETE:	return "COMPLETE";
3084 	case TRANSPORT_ISTATE_PROCESSING:
3085 					return "ISTATE_PROCESSING";
3086 	case TRANSPORT_COMPLETE_QF_WP:	return "COMPLETE_QF_WP";
3087 	case TRANSPORT_COMPLETE_QF_OK:	return "COMPLETE_QF_OK";
3088 	case TRANSPORT_COMPLETE_QF_ERR:	return "COMPLETE_QF_ERR";
3089 	}
3090 
3091 	return "(?)";
3092 }
3093 
3094 static void target_append_str(char **str, const char *txt)
3095 {
3096 	char *prev = *str;
3097 
3098 	*str = *str ? kasprintf(GFP_ATOMIC, "%s,%s", *str, txt) :
3099 		kstrdup(txt, GFP_ATOMIC);
3100 	kfree(prev);
3101 }
3102 
3103 /*
3104  * Convert a transport state bitmask into a string. The caller is
3105  * responsible for freeing the returned pointer.
3106  */
3107 static char *target_ts_to_str(u32 ts)
3108 {
3109 	char *str = NULL;
3110 
3111 	if (ts & CMD_T_ABORTED)
3112 		target_append_str(&str, "aborted");
3113 	if (ts & CMD_T_ACTIVE)
3114 		target_append_str(&str, "active");
3115 	if (ts & CMD_T_COMPLETE)
3116 		target_append_str(&str, "complete");
3117 	if (ts & CMD_T_SENT)
3118 		target_append_str(&str, "sent");
3119 	if (ts & CMD_T_STOP)
3120 		target_append_str(&str, "stop");
3121 	if (ts & CMD_T_FABRIC_STOP)
3122 		target_append_str(&str, "fabric_stop");
3123 
3124 	return str;
3125 }
3126 
3127 static const char *target_tmf_name(enum tcm_tmreq_table tmf)
3128 {
3129 	switch (tmf) {
3130 	case TMR_ABORT_TASK:		return "ABORT_TASK";
3131 	case TMR_ABORT_TASK_SET:	return "ABORT_TASK_SET";
3132 	case TMR_CLEAR_ACA:		return "CLEAR_ACA";
3133 	case TMR_CLEAR_TASK_SET:	return "CLEAR_TASK_SET";
3134 	case TMR_LUN_RESET:		return "LUN_RESET";
3135 	case TMR_TARGET_WARM_RESET:	return "TARGET_WARM_RESET";
3136 	case TMR_TARGET_COLD_RESET:	return "TARGET_COLD_RESET";
3137 	case TMR_LUN_RESET_PRO:		return "LUN_RESET_PRO";
3138 	case TMR_UNKNOWN:		break;
3139 	}
3140 	return "(?)";
3141 }
3142 
3143 void target_show_cmd(const char *pfx, struct se_cmd *cmd)
3144 {
3145 	char *ts_str = target_ts_to_str(cmd->transport_state);
3146 	const u8 *cdb = cmd->t_task_cdb;
3147 	struct se_tmr_req *tmf = cmd->se_tmr_req;
3148 
3149 	if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
3150 		pr_debug("%scmd %#02x:%#02x with tag %#llx dir %s i_state %d t_state %s len %d refcnt %d transport_state %s\n",
3151 			 pfx, cdb[0], cdb[1], cmd->tag,
3152 			 data_dir_name(cmd->data_direction),
3153 			 cmd->se_tfo->get_cmd_state(cmd),
3154 			 cmd_state_name(cmd->t_state), cmd->data_length,
3155 			 kref_read(&cmd->cmd_kref), ts_str);
3156 	} else {
3157 		pr_debug("%stmf %s with tag %#llx ref_task_tag %#llx i_state %d t_state %s refcnt %d transport_state %s\n",
3158 			 pfx, target_tmf_name(tmf->function), cmd->tag,
3159 			 tmf->ref_task_tag, cmd->se_tfo->get_cmd_state(cmd),
3160 			 cmd_state_name(cmd->t_state),
3161 			 kref_read(&cmd->cmd_kref), ts_str);
3162 	}
3163 	kfree(ts_str);
3164 }
3165 EXPORT_SYMBOL(target_show_cmd);
3166 
3167 static void target_stop_cmd_counter_confirm(struct percpu_ref *ref)
3168 {
3169 	struct target_cmd_counter *cmd_cnt = container_of(ref,
3170 						struct target_cmd_counter,
3171 						refcnt);
3172 	complete_all(&cmd_cnt->stop_done);
3173 }
3174 
3175 /**
3176  * target_stop_cmd_counter - Stop new IO from being added to the counter.
3177  * @cmd_cnt: counter to stop
3178  */
3179 void target_stop_cmd_counter(struct target_cmd_counter *cmd_cnt)
3180 {
3181 	pr_debug("Stopping command counter.\n");
3182 	if (!atomic_cmpxchg(&cmd_cnt->stopped, 0, 1))
3183 		percpu_ref_kill_and_confirm(&cmd_cnt->refcnt,
3184 					    target_stop_cmd_counter_confirm);
3185 }
3186 EXPORT_SYMBOL_GPL(target_stop_cmd_counter);
3187 
3188 /**
3189  * target_stop_session - Stop new IO from being queued on the session.
3190  * @se_sess: session to stop
3191  */
3192 void target_stop_session(struct se_session *se_sess)
3193 {
3194 	target_stop_cmd_counter(se_sess->cmd_cnt);
3195 }
3196 EXPORT_SYMBOL(target_stop_session);
3197 
3198 /**
3199  * target_wait_for_cmds - Wait for outstanding cmds.
3200  * @cmd_cnt: counter to wait for active I/O for.
3201  */
3202 void target_wait_for_cmds(struct target_cmd_counter *cmd_cnt)
3203 {
3204 	int ret;
3205 
3206 	WARN_ON_ONCE(!atomic_read(&cmd_cnt->stopped));
3207 
3208 	do {
3209 		pr_debug("Waiting for running cmds to complete.\n");
3210 		ret = wait_event_timeout(cmd_cnt->refcnt_wq,
3211 					 percpu_ref_is_zero(&cmd_cnt->refcnt),
3212 					 180 * HZ);
3213 	} while (ret <= 0);
3214 
3215 	wait_for_completion(&cmd_cnt->stop_done);
3216 	pr_debug("Waiting for cmds done.\n");
3217 }
3218 EXPORT_SYMBOL_GPL(target_wait_for_cmds);
3219 
3220 /**
3221  * target_wait_for_sess_cmds - Wait for outstanding commands
3222  * @se_sess: session to wait for active I/O
3223  */
3224 void target_wait_for_sess_cmds(struct se_session *se_sess)
3225 {
3226 	target_wait_for_cmds(se_sess->cmd_cnt);
3227 }
3228 EXPORT_SYMBOL(target_wait_for_sess_cmds);
3229 
3230 /*
3231  * Prevent that new percpu_ref_tryget_live() calls succeed and wait until
3232  * all references to the LUN have been released. Called during LUN shutdown.
3233  */
3234 void transport_clear_lun_ref(struct se_lun *lun)
3235 {
3236 	percpu_ref_kill(&lun->lun_ref);
3237 	wait_for_completion(&lun->lun_shutdown_comp);
3238 }
3239 
3240 static bool
3241 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
3242 			   bool *aborted, bool *tas, unsigned long *flags)
3243 	__releases(&cmd->t_state_lock)
3244 	__acquires(&cmd->t_state_lock)
3245 {
3246 	lockdep_assert_held(&cmd->t_state_lock);
3247 
3248 	if (fabric_stop)
3249 		cmd->transport_state |= CMD_T_FABRIC_STOP;
3250 
3251 	if (cmd->transport_state & CMD_T_ABORTED)
3252 		*aborted = true;
3253 
3254 	if (cmd->transport_state & CMD_T_TAS)
3255 		*tas = true;
3256 
3257 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
3258 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
3259 		return false;
3260 
3261 	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
3262 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
3263 		return false;
3264 
3265 	if (!(cmd->transport_state & CMD_T_ACTIVE))
3266 		return false;
3267 
3268 	if (fabric_stop && *aborted)
3269 		return false;
3270 
3271 	cmd->transport_state |= CMD_T_STOP;
3272 
3273 	target_show_cmd("wait_for_tasks: Stopping ", cmd);
3274 
3275 	spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
3276 
3277 	while (!wait_for_completion_timeout(&cmd->t_transport_stop_comp,
3278 					    180 * HZ))
3279 		target_show_cmd("wait for tasks: ", cmd);
3280 
3281 	spin_lock_irqsave(&cmd->t_state_lock, *flags);
3282 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
3283 
3284 	pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
3285 		 "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
3286 
3287 	return true;
3288 }
3289 
3290 /**
3291  * transport_wait_for_tasks - set CMD_T_STOP and wait for t_transport_stop_comp
3292  * @cmd: command to wait on
3293  */
3294 bool transport_wait_for_tasks(struct se_cmd *cmd)
3295 {
3296 	unsigned long flags;
3297 	bool ret, aborted = false, tas = false;
3298 
3299 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3300 	ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
3301 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3302 
3303 	return ret;
3304 }
3305 EXPORT_SYMBOL(transport_wait_for_tasks);
3306 
3307 struct sense_detail {
3308 	u8 key;
3309 	u8 asc;
3310 	u8 ascq;
3311 	bool add_sense_info;
3312 };
3313 
3314 static const struct sense_detail sense_detail_table[] = {
3315 	[TCM_NO_SENSE] = {
3316 		.key = NOT_READY
3317 	},
3318 	[TCM_NON_EXISTENT_LUN] = {
3319 		.key = ILLEGAL_REQUEST,
3320 		.asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
3321 	},
3322 	[TCM_UNSUPPORTED_SCSI_OPCODE] = {
3323 		.key = ILLEGAL_REQUEST,
3324 		.asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3325 	},
3326 	[TCM_SECTOR_COUNT_TOO_MANY] = {
3327 		.key = ILLEGAL_REQUEST,
3328 		.asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3329 	},
3330 	[TCM_UNKNOWN_MODE_PAGE] = {
3331 		.key = ILLEGAL_REQUEST,
3332 		.asc = 0x24, /* INVALID FIELD IN CDB */
3333 	},
3334 	[TCM_CHECK_CONDITION_ABORT_CMD] = {
3335 		.key = ABORTED_COMMAND,
3336 		.asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
3337 		.ascq = 0x03,
3338 	},
3339 	[TCM_INCORRECT_AMOUNT_OF_DATA] = {
3340 		.key = ABORTED_COMMAND,
3341 		.asc = 0x0c, /* WRITE ERROR */
3342 		.ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
3343 	},
3344 	[TCM_INVALID_CDB_FIELD] = {
3345 		.key = ILLEGAL_REQUEST,
3346 		.asc = 0x24, /* INVALID FIELD IN CDB */
3347 	},
3348 	[TCM_INVALID_PARAMETER_LIST] = {
3349 		.key = ILLEGAL_REQUEST,
3350 		.asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
3351 	},
3352 	[TCM_TOO_MANY_TARGET_DESCS] = {
3353 		.key = ILLEGAL_REQUEST,
3354 		.asc = 0x26,
3355 		.ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
3356 	},
3357 	[TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
3358 		.key = ILLEGAL_REQUEST,
3359 		.asc = 0x26,
3360 		.ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
3361 	},
3362 	[TCM_TOO_MANY_SEGMENT_DESCS] = {
3363 		.key = ILLEGAL_REQUEST,
3364 		.asc = 0x26,
3365 		.ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
3366 	},
3367 	[TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
3368 		.key = ILLEGAL_REQUEST,
3369 		.asc = 0x26,
3370 		.ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
3371 	},
3372 	[TCM_PARAMETER_LIST_LENGTH_ERROR] = {
3373 		.key = ILLEGAL_REQUEST,
3374 		.asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
3375 	},
3376 	[TCM_UNEXPECTED_UNSOLICITED_DATA] = {
3377 		.key = ILLEGAL_REQUEST,
3378 		.asc = 0x0c, /* WRITE ERROR */
3379 		.ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
3380 	},
3381 	[TCM_SERVICE_CRC_ERROR] = {
3382 		.key = ABORTED_COMMAND,
3383 		.asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
3384 		.ascq = 0x05, /* N/A */
3385 	},
3386 	[TCM_SNACK_REJECTED] = {
3387 		.key = ABORTED_COMMAND,
3388 		.asc = 0x11, /* READ ERROR */
3389 		.ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
3390 	},
3391 	[TCM_WRITE_PROTECTED] = {
3392 		.key = DATA_PROTECT,
3393 		.asc = 0x27, /* WRITE PROTECTED */
3394 	},
3395 	[TCM_ADDRESS_OUT_OF_RANGE] = {
3396 		.key = ILLEGAL_REQUEST,
3397 		.asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
3398 	},
3399 	[TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
3400 		.key = UNIT_ATTENTION,
3401 	},
3402 	[TCM_MISCOMPARE_VERIFY] = {
3403 		.key = MISCOMPARE,
3404 		.asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
3405 		.ascq = 0x00,
3406 		.add_sense_info = true,
3407 	},
3408 	[TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
3409 		.key = ABORTED_COMMAND,
3410 		.asc = 0x10,
3411 		.ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
3412 		.add_sense_info = true,
3413 	},
3414 	[TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
3415 		.key = ABORTED_COMMAND,
3416 		.asc = 0x10,
3417 		.ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
3418 		.add_sense_info = true,
3419 	},
3420 	[TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
3421 		.key = ABORTED_COMMAND,
3422 		.asc = 0x10,
3423 		.ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
3424 		.add_sense_info = true,
3425 	},
3426 	[TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
3427 		.key = COPY_ABORTED,
3428 		.asc = 0x0d,
3429 		.ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
3430 
3431 	},
3432 	[TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
3433 		/*
3434 		 * Returning ILLEGAL REQUEST would cause immediate IO errors on
3435 		 * Solaris initiators.  Returning NOT READY instead means the
3436 		 * operations will be retried a finite number of times and we
3437 		 * can survive intermittent errors.
3438 		 */
3439 		.key = NOT_READY,
3440 		.asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
3441 	},
3442 	[TCM_INSUFFICIENT_REGISTRATION_RESOURCES] = {
3443 		/*
3444 		 * From spc4r22 section5.7.7,5.7.8
3445 		 * If a PERSISTENT RESERVE OUT command with a REGISTER service action
3446 		 * or a REGISTER AND IGNORE EXISTING KEY service action or
3447 		 * REGISTER AND MOVE service actionis attempted,
3448 		 * but there are insufficient device server resources to complete the
3449 		 * operation, then the command shall be terminated with CHECK CONDITION
3450 		 * status, with the sense key set to ILLEGAL REQUEST,and the additonal
3451 		 * sense code set to INSUFFICIENT REGISTRATION RESOURCES.
3452 		 */
3453 		.key = ILLEGAL_REQUEST,
3454 		.asc = 0x55,
3455 		.ascq = 0x04, /* INSUFFICIENT REGISTRATION RESOURCES */
3456 	},
3457 	[TCM_INVALID_FIELD_IN_COMMAND_IU] = {
3458 		.key = ILLEGAL_REQUEST,
3459 		.asc = 0x0e,
3460 		.ascq = 0x03, /* INVALID FIELD IN COMMAND INFORMATION UNIT */
3461 	},
3462 	[TCM_ALUA_TG_PT_STANDBY] = {
3463 		.key = NOT_READY,
3464 		.asc = 0x04,
3465 		.ascq = ASCQ_04H_ALUA_TG_PT_STANDBY,
3466 	},
3467 	[TCM_ALUA_TG_PT_UNAVAILABLE] = {
3468 		.key = NOT_READY,
3469 		.asc = 0x04,
3470 		.ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE,
3471 	},
3472 	[TCM_ALUA_STATE_TRANSITION] = {
3473 		.key = NOT_READY,
3474 		.asc = 0x04,
3475 		.ascq = ASCQ_04H_ALUA_STATE_TRANSITION,
3476 	},
3477 	[TCM_ALUA_OFFLINE] = {
3478 		.key = NOT_READY,
3479 		.asc = 0x04,
3480 		.ascq = ASCQ_04H_ALUA_OFFLINE,
3481 	},
3482 };
3483 
3484 /**
3485  * translate_sense_reason - translate a sense reason into T10 key, asc and ascq
3486  * @cmd: SCSI command in which the resulting sense buffer or SCSI status will
3487  *   be stored.
3488  * @reason: LIO sense reason code. If this argument has the value
3489  *   TCM_CHECK_CONDITION_UNIT_ATTENTION, try to dequeue a unit attention. If
3490  *   dequeuing a unit attention fails due to multiple commands being processed
3491  *   concurrently, set the command status to BUSY.
3492  *
3493  * Return: 0 upon success or -EINVAL if the sense buffer is too small.
3494  */
3495 static void translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
3496 {
3497 	const struct sense_detail *sd;
3498 	u8 *buffer = cmd->sense_buffer;
3499 	int r = (__force int)reason;
3500 	u8 key, asc, ascq;
3501 	bool desc_format = target_sense_desc_format(cmd->se_dev);
3502 
3503 	if (r < ARRAY_SIZE(sense_detail_table) && sense_detail_table[r].key)
3504 		sd = &sense_detail_table[r];
3505 	else
3506 		sd = &sense_detail_table[(__force int)
3507 				       TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
3508 
3509 	key = sd->key;
3510 	if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
3511 		if (!core_scsi3_ua_for_check_condition(cmd, &key, &asc,
3512 						       &ascq)) {
3513 			cmd->scsi_status = SAM_STAT_BUSY;
3514 			return;
3515 		}
3516 	} else {
3517 		WARN_ON_ONCE(sd->asc == 0);
3518 		asc = sd->asc;
3519 		ascq = sd->ascq;
3520 	}
3521 
3522 	cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
3523 	cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
3524 	cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
3525 	scsi_build_sense_buffer(desc_format, buffer, key, asc, ascq);
3526 	if (sd->add_sense_info)
3527 		WARN_ON_ONCE(scsi_set_sense_information(buffer,
3528 							cmd->scsi_sense_length,
3529 							cmd->sense_info) < 0);
3530 }
3531 
3532 int
3533 transport_send_check_condition_and_sense(struct se_cmd *cmd,
3534 		sense_reason_t reason, int from_transport)
3535 {
3536 	unsigned long flags;
3537 
3538 	WARN_ON_ONCE(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB);
3539 
3540 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3541 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
3542 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3543 		return 0;
3544 	}
3545 	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
3546 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3547 
3548 	if (!from_transport)
3549 		translate_sense_reason(cmd, reason);
3550 
3551 	trace_target_cmd_complete(cmd);
3552 	return cmd->se_tfo->queue_status(cmd);
3553 }
3554 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3555 
3556 /**
3557  * target_send_busy - Send SCSI BUSY status back to the initiator
3558  * @cmd: SCSI command for which to send a BUSY reply.
3559  *
3560  * Note: Only call this function if target_submit_cmd*() failed.
3561  */
3562 int target_send_busy(struct se_cmd *cmd)
3563 {
3564 	WARN_ON_ONCE(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB);
3565 
3566 	cmd->scsi_status = SAM_STAT_BUSY;
3567 	trace_target_cmd_complete(cmd);
3568 	return cmd->se_tfo->queue_status(cmd);
3569 }
3570 EXPORT_SYMBOL(target_send_busy);
3571 
3572 static void target_tmr_work(struct work_struct *work)
3573 {
3574 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3575 	struct se_device *dev = cmd->se_dev;
3576 	struct se_tmr_req *tmr = cmd->se_tmr_req;
3577 	int ret;
3578 
3579 	if (cmd->transport_state & CMD_T_ABORTED)
3580 		goto aborted;
3581 
3582 	switch (tmr->function) {
3583 	case TMR_ABORT_TASK:
3584 		core_tmr_abort_task(dev, tmr, cmd->se_sess);
3585 		break;
3586 	case TMR_ABORT_TASK_SET:
3587 	case TMR_CLEAR_ACA:
3588 	case TMR_CLEAR_TASK_SET:
3589 		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3590 		break;
3591 	case TMR_LUN_RESET:
3592 		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3593 		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3594 					 TMR_FUNCTION_REJECTED;
3595 		if (tmr->response == TMR_FUNCTION_COMPLETE) {
3596 			target_dev_ua_allocate(dev, 0x29,
3597 					       ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3598 		}
3599 		break;
3600 	case TMR_TARGET_WARM_RESET:
3601 		tmr->response = TMR_FUNCTION_REJECTED;
3602 		break;
3603 	case TMR_TARGET_COLD_RESET:
3604 		tmr->response = TMR_FUNCTION_REJECTED;
3605 		break;
3606 	default:
3607 		pr_err("Unknown TMR function: 0x%02x.\n",
3608 				tmr->function);
3609 		tmr->response = TMR_FUNCTION_REJECTED;
3610 		break;
3611 	}
3612 
3613 	if (cmd->transport_state & CMD_T_ABORTED)
3614 		goto aborted;
3615 
3616 	cmd->se_tfo->queue_tm_rsp(cmd);
3617 
3618 	transport_lun_remove_cmd(cmd);
3619 	transport_cmd_check_stop_to_fabric(cmd);
3620 	return;
3621 
3622 aborted:
3623 	target_handle_abort(cmd);
3624 }
3625 
3626 int transport_generic_handle_tmr(
3627 	struct se_cmd *cmd)
3628 {
3629 	unsigned long flags;
3630 	bool aborted = false;
3631 
3632 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3633 	if (cmd->transport_state & CMD_T_ABORTED) {
3634 		aborted = true;
3635 	} else {
3636 		cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3637 		cmd->transport_state |= CMD_T_ACTIVE;
3638 	}
3639 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3640 
3641 	if (aborted) {
3642 		pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d ref_tag: %llu tag: %llu\n",
3643 				    cmd->se_tmr_req->function,
3644 				    cmd->se_tmr_req->ref_task_tag, cmd->tag);
3645 		target_handle_abort(cmd);
3646 		return 0;
3647 	}
3648 
3649 	INIT_WORK(&cmd->work, target_tmr_work);
3650 	schedule_work(&cmd->work);
3651 	return 0;
3652 }
3653 EXPORT_SYMBOL(transport_generic_handle_tmr);
3654 
3655 bool
3656 target_check_wce(struct se_device *dev)
3657 {
3658 	bool wce = false;
3659 
3660 	if (dev->transport->get_write_cache)
3661 		wce = dev->transport->get_write_cache(dev);
3662 	else if (dev->dev_attrib.emulate_write_cache > 0)
3663 		wce = true;
3664 
3665 	return wce;
3666 }
3667 
3668 bool
3669 target_check_fua(struct se_device *dev)
3670 {
3671 	return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3672 }
3673