xref: /linux/drivers/target/target_core_transport.c (revision 55d0969c451159cff86949b38c39171cab962069)
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 <linux/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 	kfree(cmd_cnt);
268 }
269 EXPORT_SYMBOL_GPL(target_free_cmd_counter);
270 
271 /**
272  * transport_init_session - initialize a session object
273  * @se_sess: Session object pointer.
274  *
275  * The caller must have zero-initialized @se_sess before calling this function.
276  */
277 void transport_init_session(struct se_session *se_sess)
278 {
279 	INIT_LIST_HEAD(&se_sess->sess_list);
280 	INIT_LIST_HEAD(&se_sess->sess_acl_list);
281 	spin_lock_init(&se_sess->sess_cmd_lock);
282 }
283 EXPORT_SYMBOL(transport_init_session);
284 
285 /**
286  * transport_alloc_session - allocate a session object and initialize it
287  * @sup_prot_ops: bitmask that defines which T10-PI modes are supported.
288  */
289 struct se_session *transport_alloc_session(enum target_prot_op sup_prot_ops)
290 {
291 	struct se_session *se_sess;
292 
293 	se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
294 	if (!se_sess) {
295 		pr_err("Unable to allocate struct se_session from"
296 				" se_sess_cache\n");
297 		return ERR_PTR(-ENOMEM);
298 	}
299 	transport_init_session(se_sess);
300 	se_sess->sup_prot_ops = sup_prot_ops;
301 
302 	return se_sess;
303 }
304 EXPORT_SYMBOL(transport_alloc_session);
305 
306 /**
307  * transport_alloc_session_tags - allocate target driver private data
308  * @se_sess:  Session pointer.
309  * @tag_num:  Maximum number of in-flight commands between initiator and target.
310  * @tag_size: Size in bytes of the private data a target driver associates with
311  *	      each command.
312  */
313 int transport_alloc_session_tags(struct se_session *se_sess,
314 			         unsigned int tag_num, unsigned int tag_size)
315 {
316 	int rc;
317 
318 	se_sess->sess_cmd_map = kvcalloc(tag_size, tag_num,
319 					 GFP_KERNEL | __GFP_RETRY_MAYFAIL);
320 	if (!se_sess->sess_cmd_map) {
321 		pr_err("Unable to allocate se_sess->sess_cmd_map\n");
322 		return -ENOMEM;
323 	}
324 
325 	rc = sbitmap_queue_init_node(&se_sess->sess_tag_pool, tag_num, -1,
326 			false, GFP_KERNEL, NUMA_NO_NODE);
327 	if (rc < 0) {
328 		pr_err("Unable to init se_sess->sess_tag_pool,"
329 			" tag_num: %u\n", tag_num);
330 		kvfree(se_sess->sess_cmd_map);
331 		se_sess->sess_cmd_map = NULL;
332 		return -ENOMEM;
333 	}
334 
335 	return 0;
336 }
337 EXPORT_SYMBOL(transport_alloc_session_tags);
338 
339 /**
340  * transport_init_session_tags - allocate a session and target driver private data
341  * @tag_num:  Maximum number of in-flight commands between initiator and target.
342  * @tag_size: Size in bytes of the private data a target driver associates with
343  *	      each command.
344  * @sup_prot_ops: bitmask that defines which T10-PI modes are supported.
345  */
346 static struct se_session *
347 transport_init_session_tags(unsigned int tag_num, unsigned int tag_size,
348 			    enum target_prot_op sup_prot_ops)
349 {
350 	struct se_session *se_sess;
351 	int rc;
352 
353 	if (tag_num != 0 && !tag_size) {
354 		pr_err("init_session_tags called with percpu-ida tag_num:"
355 		       " %u, but zero tag_size\n", tag_num);
356 		return ERR_PTR(-EINVAL);
357 	}
358 	if (!tag_num && tag_size) {
359 		pr_err("init_session_tags called with percpu-ida tag_size:"
360 		       " %u, but zero tag_num\n", tag_size);
361 		return ERR_PTR(-EINVAL);
362 	}
363 
364 	se_sess = transport_alloc_session(sup_prot_ops);
365 	if (IS_ERR(se_sess))
366 		return se_sess;
367 
368 	rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
369 	if (rc < 0) {
370 		transport_free_session(se_sess);
371 		return ERR_PTR(-ENOMEM);
372 	}
373 
374 	return se_sess;
375 }
376 
377 /*
378  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
379  */
380 void __transport_register_session(
381 	struct se_portal_group *se_tpg,
382 	struct se_node_acl *se_nacl,
383 	struct se_session *se_sess,
384 	void *fabric_sess_ptr)
385 {
386 	const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
387 	unsigned char buf[PR_REG_ISID_LEN];
388 	unsigned long flags;
389 
390 	se_sess->se_tpg = se_tpg;
391 	se_sess->fabric_sess_ptr = fabric_sess_ptr;
392 	/*
393 	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
394 	 *
395 	 * Only set for struct se_session's that will actually be moving I/O.
396 	 * eg: *NOT* discovery sessions.
397 	 */
398 	if (se_nacl) {
399 		/*
400 		 *
401 		 * Determine if fabric allows for T10-PI feature bits exposed to
402 		 * initiators for device backends with !dev->dev_attrib.pi_prot_type.
403 		 *
404 		 * If so, then always save prot_type on a per se_node_acl node
405 		 * basis and re-instate the previous sess_prot_type to avoid
406 		 * disabling PI from below any previously initiator side
407 		 * registered LUNs.
408 		 */
409 		if (se_nacl->saved_prot_type)
410 			se_sess->sess_prot_type = se_nacl->saved_prot_type;
411 		else if (tfo->tpg_check_prot_fabric_only)
412 			se_sess->sess_prot_type = se_nacl->saved_prot_type =
413 					tfo->tpg_check_prot_fabric_only(se_tpg);
414 		/*
415 		 * If the fabric module supports an ISID based TransportID,
416 		 * save this value in binary from the fabric I_T Nexus now.
417 		 */
418 		if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
419 			memset(&buf[0], 0, PR_REG_ISID_LEN);
420 			se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
421 					&buf[0], PR_REG_ISID_LEN);
422 			se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
423 		}
424 
425 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
426 		/*
427 		 * The se_nacl->nacl_sess pointer will be set to the
428 		 * last active I_T Nexus for each struct se_node_acl.
429 		 */
430 		se_nacl->nacl_sess = se_sess;
431 
432 		list_add_tail(&se_sess->sess_acl_list,
433 			      &se_nacl->acl_sess_list);
434 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
435 	}
436 	list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
437 
438 	pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
439 		se_tpg->se_tpg_tfo->fabric_name, se_sess->fabric_sess_ptr);
440 }
441 EXPORT_SYMBOL(__transport_register_session);
442 
443 void transport_register_session(
444 	struct se_portal_group *se_tpg,
445 	struct se_node_acl *se_nacl,
446 	struct se_session *se_sess,
447 	void *fabric_sess_ptr)
448 {
449 	unsigned long flags;
450 
451 	spin_lock_irqsave(&se_tpg->session_lock, flags);
452 	__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
453 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
454 }
455 EXPORT_SYMBOL(transport_register_session);
456 
457 struct se_session *
458 target_setup_session(struct se_portal_group *tpg,
459 		     unsigned int tag_num, unsigned int tag_size,
460 		     enum target_prot_op prot_op,
461 		     const char *initiatorname, void *private,
462 		     int (*callback)(struct se_portal_group *,
463 				     struct se_session *, void *))
464 {
465 	struct target_cmd_counter *cmd_cnt;
466 	struct se_session *sess;
467 	int rc;
468 
469 	cmd_cnt = target_alloc_cmd_counter();
470 	if (!cmd_cnt)
471 		return ERR_PTR(-ENOMEM);
472 	/*
473 	 * If the fabric driver is using percpu-ida based pre allocation
474 	 * of I/O descriptor tags, go ahead and perform that setup now..
475 	 */
476 	if (tag_num != 0)
477 		sess = transport_init_session_tags(tag_num, tag_size, prot_op);
478 	else
479 		sess = transport_alloc_session(prot_op);
480 
481 	if (IS_ERR(sess)) {
482 		rc = PTR_ERR(sess);
483 		goto free_cnt;
484 	}
485 	sess->cmd_cnt = cmd_cnt;
486 
487 	sess->se_node_acl = core_tpg_check_initiator_node_acl(tpg,
488 					(unsigned char *)initiatorname);
489 	if (!sess->se_node_acl) {
490 		rc = -EACCES;
491 		goto free_sess;
492 	}
493 	/*
494 	 * Go ahead and perform any remaining fabric setup that is
495 	 * required before transport_register_session().
496 	 */
497 	if (callback != NULL) {
498 		rc = callback(tpg, sess, private);
499 		if (rc)
500 			goto free_sess;
501 	}
502 
503 	transport_register_session(tpg, sess->se_node_acl, sess, private);
504 	return sess;
505 
506 free_sess:
507 	transport_free_session(sess);
508 	return ERR_PTR(rc);
509 
510 free_cnt:
511 	target_free_cmd_counter(cmd_cnt);
512 	return ERR_PTR(rc);
513 }
514 EXPORT_SYMBOL(target_setup_session);
515 
516 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
517 {
518 	struct se_session *se_sess;
519 	ssize_t len = 0;
520 
521 	spin_lock_bh(&se_tpg->session_lock);
522 	list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
523 		if (!se_sess->se_node_acl)
524 			continue;
525 		if (!se_sess->se_node_acl->dynamic_node_acl)
526 			continue;
527 		if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
528 			break;
529 
530 		len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
531 				se_sess->se_node_acl->initiatorname);
532 		len += 1; /* Include NULL terminator */
533 	}
534 	spin_unlock_bh(&se_tpg->session_lock);
535 
536 	return len;
537 }
538 EXPORT_SYMBOL(target_show_dynamic_sessions);
539 
540 static void target_complete_nacl(struct kref *kref)
541 {
542 	struct se_node_acl *nacl = container_of(kref,
543 				struct se_node_acl, acl_kref);
544 	struct se_portal_group *se_tpg = nacl->se_tpg;
545 
546 	if (!nacl->dynamic_stop) {
547 		complete(&nacl->acl_free_comp);
548 		return;
549 	}
550 
551 	mutex_lock(&se_tpg->acl_node_mutex);
552 	list_del_init(&nacl->acl_list);
553 	mutex_unlock(&se_tpg->acl_node_mutex);
554 
555 	core_tpg_wait_for_nacl_pr_ref(nacl);
556 	core_free_device_list_for_node(nacl, se_tpg);
557 	kfree(nacl);
558 }
559 
560 void target_put_nacl(struct se_node_acl *nacl)
561 {
562 	kref_put(&nacl->acl_kref, target_complete_nacl);
563 }
564 EXPORT_SYMBOL(target_put_nacl);
565 
566 void transport_deregister_session_configfs(struct se_session *se_sess)
567 {
568 	struct se_node_acl *se_nacl;
569 	unsigned long flags;
570 	/*
571 	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
572 	 */
573 	se_nacl = se_sess->se_node_acl;
574 	if (se_nacl) {
575 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
576 		if (!list_empty(&se_sess->sess_acl_list))
577 			list_del_init(&se_sess->sess_acl_list);
578 		/*
579 		 * If the session list is empty, then clear the pointer.
580 		 * Otherwise, set the struct se_session pointer from the tail
581 		 * element of the per struct se_node_acl active session list.
582 		 */
583 		if (list_empty(&se_nacl->acl_sess_list))
584 			se_nacl->nacl_sess = NULL;
585 		else {
586 			se_nacl->nacl_sess = container_of(
587 					se_nacl->acl_sess_list.prev,
588 					struct se_session, sess_acl_list);
589 		}
590 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
591 	}
592 }
593 EXPORT_SYMBOL(transport_deregister_session_configfs);
594 
595 void transport_free_session(struct se_session *se_sess)
596 {
597 	struct se_node_acl *se_nacl = se_sess->se_node_acl;
598 
599 	/*
600 	 * Drop the se_node_acl->nacl_kref obtained from within
601 	 * core_tpg_get_initiator_node_acl().
602 	 */
603 	if (se_nacl) {
604 		struct se_portal_group *se_tpg = se_nacl->se_tpg;
605 		const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo;
606 		unsigned long flags;
607 
608 		se_sess->se_node_acl = NULL;
609 
610 		/*
611 		 * Also determine if we need to drop the extra ->cmd_kref if
612 		 * it had been previously dynamically generated, and
613 		 * the endpoint is not caching dynamic ACLs.
614 		 */
615 		mutex_lock(&se_tpg->acl_node_mutex);
616 		if (se_nacl->dynamic_node_acl &&
617 		    !se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
618 			spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
619 			if (list_empty(&se_nacl->acl_sess_list))
620 				se_nacl->dynamic_stop = true;
621 			spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
622 
623 			if (se_nacl->dynamic_stop)
624 				list_del_init(&se_nacl->acl_list);
625 		}
626 		mutex_unlock(&se_tpg->acl_node_mutex);
627 
628 		if (se_nacl->dynamic_stop)
629 			target_put_nacl(se_nacl);
630 
631 		target_put_nacl(se_nacl);
632 	}
633 	if (se_sess->sess_cmd_map) {
634 		sbitmap_queue_free(&se_sess->sess_tag_pool);
635 		kvfree(se_sess->sess_cmd_map);
636 	}
637 	if (se_sess->cmd_cnt)
638 		target_free_cmd_counter(se_sess->cmd_cnt);
639 	kmem_cache_free(se_sess_cache, se_sess);
640 }
641 EXPORT_SYMBOL(transport_free_session);
642 
643 static int target_release_res(struct se_device *dev, void *data)
644 {
645 	struct se_session *sess = data;
646 
647 	if (dev->reservation_holder == sess)
648 		target_release_reservation(dev);
649 	return 0;
650 }
651 
652 void transport_deregister_session(struct se_session *se_sess)
653 {
654 	struct se_portal_group *se_tpg = se_sess->se_tpg;
655 	unsigned long flags;
656 
657 	if (!se_tpg) {
658 		transport_free_session(se_sess);
659 		return;
660 	}
661 
662 	spin_lock_irqsave(&se_tpg->session_lock, flags);
663 	list_del(&se_sess->sess_list);
664 	se_sess->se_tpg = NULL;
665 	se_sess->fabric_sess_ptr = NULL;
666 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
667 
668 	/*
669 	 * Since the session is being removed, release SPC-2
670 	 * reservations held by the session that is disappearing.
671 	 */
672 	target_for_each_device(target_release_res, se_sess);
673 
674 	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
675 		se_tpg->se_tpg_tfo->fabric_name);
676 	/*
677 	 * If last kref is dropping now for an explicit NodeACL, awake sleeping
678 	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
679 	 * removal context from within transport_free_session() code.
680 	 *
681 	 * For dynamic ACL, target_put_nacl() uses target_complete_nacl()
682 	 * to release all remaining generate_node_acl=1 created ACL resources.
683 	 */
684 
685 	transport_free_session(se_sess);
686 }
687 EXPORT_SYMBOL(transport_deregister_session);
688 
689 void target_remove_session(struct se_session *se_sess)
690 {
691 	transport_deregister_session_configfs(se_sess);
692 	transport_deregister_session(se_sess);
693 }
694 EXPORT_SYMBOL(target_remove_session);
695 
696 static void target_remove_from_state_list(struct se_cmd *cmd)
697 {
698 	struct se_device *dev = cmd->se_dev;
699 	unsigned long flags;
700 
701 	if (!dev)
702 		return;
703 
704 	spin_lock_irqsave(&dev->queues[cmd->cpuid].lock, flags);
705 	if (cmd->state_active) {
706 		list_del(&cmd->state_list);
707 		cmd->state_active = false;
708 	}
709 	spin_unlock_irqrestore(&dev->queues[cmd->cpuid].lock, flags);
710 }
711 
712 static void target_remove_from_tmr_list(struct se_cmd *cmd)
713 {
714 	struct se_device *dev = NULL;
715 	unsigned long flags;
716 
717 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
718 		dev = cmd->se_tmr_req->tmr_dev;
719 
720 	if (dev) {
721 		spin_lock_irqsave(&dev->se_tmr_lock, flags);
722 		if (cmd->se_tmr_req->tmr_dev)
723 			list_del_init(&cmd->se_tmr_req->tmr_list);
724 		spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
725 	}
726 }
727 /*
728  * This function is called by the target core after the target core has
729  * finished processing a SCSI command or SCSI TMF. Both the regular command
730  * processing code and the code for aborting commands can call this
731  * function. CMD_T_STOP is set if and only if another thread is waiting
732  * inside transport_wait_for_tasks() for t_transport_stop_comp.
733  */
734 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
735 {
736 	unsigned long flags;
737 
738 	spin_lock_irqsave(&cmd->t_state_lock, flags);
739 	/*
740 	 * Determine if frontend context caller is requesting the stopping of
741 	 * this command for frontend exceptions.
742 	 */
743 	if (cmd->transport_state & CMD_T_STOP) {
744 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
745 			__func__, __LINE__, cmd->tag);
746 
747 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
748 
749 		complete_all(&cmd->t_transport_stop_comp);
750 		return 1;
751 	}
752 	cmd->transport_state &= ~CMD_T_ACTIVE;
753 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
754 
755 	/*
756 	 * Some fabric modules like tcm_loop can release their internally
757 	 * allocated I/O reference and struct se_cmd now.
758 	 *
759 	 * Fabric modules are expected to return '1' here if the se_cmd being
760 	 * passed is released at this point, or zero if not being released.
761 	 */
762 	return cmd->se_tfo->check_stop_free(cmd);
763 }
764 
765 static void transport_lun_remove_cmd(struct se_cmd *cmd)
766 {
767 	struct se_lun *lun = cmd->se_lun;
768 
769 	if (!lun)
770 		return;
771 
772 	target_remove_from_state_list(cmd);
773 	target_remove_from_tmr_list(cmd);
774 
775 	if (cmpxchg(&cmd->lun_ref_active, true, false))
776 		percpu_ref_put(&lun->lun_ref);
777 
778 	/*
779 	 * Clear struct se_cmd->se_lun before the handoff to FE.
780 	 */
781 	cmd->se_lun = NULL;
782 }
783 
784 static void target_complete_failure_work(struct work_struct *work)
785 {
786 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
787 
788 	transport_generic_request_failure(cmd, cmd->sense_reason);
789 }
790 
791 /*
792  * Used when asking transport to copy Sense Data from the underlying
793  * Linux/SCSI struct scsi_cmnd
794  */
795 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
796 {
797 	struct se_device *dev = cmd->se_dev;
798 
799 	WARN_ON(!cmd->se_lun);
800 
801 	if (!dev)
802 		return NULL;
803 
804 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
805 		return NULL;
806 
807 	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
808 
809 	pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
810 		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
811 	return cmd->sense_buffer;
812 }
813 
814 void transport_copy_sense_to_cmd(struct se_cmd *cmd, unsigned char *sense)
815 {
816 	unsigned char *cmd_sense_buf;
817 	unsigned long flags;
818 
819 	spin_lock_irqsave(&cmd->t_state_lock, flags);
820 	cmd_sense_buf = transport_get_sense_buffer(cmd);
821 	if (!cmd_sense_buf) {
822 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
823 		return;
824 	}
825 
826 	cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
827 	memcpy(cmd_sense_buf, sense, cmd->scsi_sense_length);
828 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
829 }
830 EXPORT_SYMBOL(transport_copy_sense_to_cmd);
831 
832 static void target_handle_abort(struct se_cmd *cmd)
833 {
834 	bool tas = cmd->transport_state & CMD_T_TAS;
835 	bool ack_kref = cmd->se_cmd_flags & SCF_ACK_KREF;
836 	int ret;
837 
838 	pr_debug("tag %#llx: send_abort_response = %d\n", cmd->tag, tas);
839 
840 	if (tas) {
841 		if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
842 			cmd->scsi_status = SAM_STAT_TASK_ABORTED;
843 			pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
844 				 cmd->t_task_cdb[0], cmd->tag);
845 			trace_target_cmd_complete(cmd);
846 			ret = cmd->se_tfo->queue_status(cmd);
847 			if (ret) {
848 				transport_handle_queue_full(cmd, cmd->se_dev,
849 							    ret, false);
850 				return;
851 			}
852 		} else {
853 			cmd->se_tmr_req->response = TMR_FUNCTION_REJECTED;
854 			cmd->se_tfo->queue_tm_rsp(cmd);
855 		}
856 	} else {
857 		/*
858 		 * Allow the fabric driver to unmap any resources before
859 		 * releasing the descriptor via TFO->release_cmd().
860 		 */
861 		cmd->se_tfo->aborted_task(cmd);
862 		if (ack_kref)
863 			WARN_ON_ONCE(target_put_sess_cmd(cmd) != 0);
864 		/*
865 		 * To do: establish a unit attention condition on the I_T
866 		 * nexus associated with cmd. See also the paragraph "Aborting
867 		 * commands" in SAM.
868 		 */
869 	}
870 
871 	WARN_ON_ONCE(kref_read(&cmd->cmd_kref) == 0);
872 
873 	transport_lun_remove_cmd(cmd);
874 
875 	transport_cmd_check_stop_to_fabric(cmd);
876 }
877 
878 static void target_abort_work(struct work_struct *work)
879 {
880 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
881 
882 	target_handle_abort(cmd);
883 }
884 
885 static bool target_cmd_interrupted(struct se_cmd *cmd)
886 {
887 	int post_ret;
888 
889 	if (cmd->transport_state & CMD_T_ABORTED) {
890 		if (cmd->transport_complete_callback)
891 			cmd->transport_complete_callback(cmd, false, &post_ret);
892 		INIT_WORK(&cmd->work, target_abort_work);
893 		queue_work(target_completion_wq, &cmd->work);
894 		return true;
895 	} else if (cmd->transport_state & CMD_T_STOP) {
896 		if (cmd->transport_complete_callback)
897 			cmd->transport_complete_callback(cmd, false, &post_ret);
898 		complete_all(&cmd->t_transport_stop_comp);
899 		return true;
900 	}
901 
902 	return false;
903 }
904 
905 /* May be called from interrupt context so must not sleep. */
906 void target_complete_cmd_with_sense(struct se_cmd *cmd, u8 scsi_status,
907 				    sense_reason_t sense_reason)
908 {
909 	struct se_wwn *wwn = cmd->se_sess->se_tpg->se_tpg_wwn;
910 	int success, cpu;
911 	unsigned long flags;
912 
913 	if (target_cmd_interrupted(cmd))
914 		return;
915 
916 	cmd->scsi_status = scsi_status;
917 	cmd->sense_reason = sense_reason;
918 
919 	spin_lock_irqsave(&cmd->t_state_lock, flags);
920 	switch (cmd->scsi_status) {
921 	case SAM_STAT_CHECK_CONDITION:
922 		if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
923 			success = 1;
924 		else
925 			success = 0;
926 		break;
927 	default:
928 		success = 1;
929 		break;
930 	}
931 
932 	cmd->t_state = TRANSPORT_COMPLETE;
933 	cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
934 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
935 
936 	INIT_WORK(&cmd->work, success ? target_complete_ok_work :
937 		  target_complete_failure_work);
938 
939 	if (!wwn || wwn->cmd_compl_affinity == SE_COMPL_AFFINITY_CPUID)
940 		cpu = cmd->cpuid;
941 	else
942 		cpu = wwn->cmd_compl_affinity;
943 
944 	queue_work_on(cpu, target_completion_wq, &cmd->work);
945 }
946 EXPORT_SYMBOL(target_complete_cmd_with_sense);
947 
948 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
949 {
950 	target_complete_cmd_with_sense(cmd, scsi_status, scsi_status ?
951 			      TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE :
952 			      TCM_NO_SENSE);
953 }
954 EXPORT_SYMBOL(target_complete_cmd);
955 
956 void target_set_cmd_data_length(struct se_cmd *cmd, int length)
957 {
958 	if (length < cmd->data_length) {
959 		if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
960 			cmd->residual_count += cmd->data_length - length;
961 		} else {
962 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
963 			cmd->residual_count = cmd->data_length - length;
964 		}
965 
966 		cmd->data_length = length;
967 	}
968 }
969 EXPORT_SYMBOL(target_set_cmd_data_length);
970 
971 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
972 {
973 	if (scsi_status == SAM_STAT_GOOD ||
974 	    cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) {
975 		target_set_cmd_data_length(cmd, length);
976 	}
977 
978 	target_complete_cmd(cmd, scsi_status);
979 }
980 EXPORT_SYMBOL(target_complete_cmd_with_length);
981 
982 static void target_add_to_state_list(struct se_cmd *cmd)
983 {
984 	struct se_device *dev = cmd->se_dev;
985 	unsigned long flags;
986 
987 	spin_lock_irqsave(&dev->queues[cmd->cpuid].lock, flags);
988 	if (!cmd->state_active) {
989 		list_add_tail(&cmd->state_list,
990 			      &dev->queues[cmd->cpuid].state_list);
991 		cmd->state_active = true;
992 	}
993 	spin_unlock_irqrestore(&dev->queues[cmd->cpuid].lock, flags);
994 }
995 
996 /*
997  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
998  */
999 static void transport_write_pending_qf(struct se_cmd *cmd);
1000 static void transport_complete_qf(struct se_cmd *cmd);
1001 
1002 void target_qf_do_work(struct work_struct *work)
1003 {
1004 	struct se_device *dev = container_of(work, struct se_device,
1005 					qf_work_queue);
1006 	LIST_HEAD(qf_cmd_list);
1007 	struct se_cmd *cmd, *cmd_tmp;
1008 
1009 	spin_lock_irq(&dev->qf_cmd_lock);
1010 	list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
1011 	spin_unlock_irq(&dev->qf_cmd_lock);
1012 
1013 	list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
1014 		list_del(&cmd->se_qf_node);
1015 		atomic_dec_mb(&dev->dev_qf_count);
1016 
1017 		pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
1018 			" context: %s\n", cmd->se_tfo->fabric_name, cmd,
1019 			(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
1020 			(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
1021 			: "UNKNOWN");
1022 
1023 		if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
1024 			transport_write_pending_qf(cmd);
1025 		else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK ||
1026 			 cmd->t_state == TRANSPORT_COMPLETE_QF_ERR)
1027 			transport_complete_qf(cmd);
1028 	}
1029 }
1030 
1031 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
1032 {
1033 	switch (cmd->data_direction) {
1034 	case DMA_NONE:
1035 		return "NONE";
1036 	case DMA_FROM_DEVICE:
1037 		return "READ";
1038 	case DMA_TO_DEVICE:
1039 		return "WRITE";
1040 	case DMA_BIDIRECTIONAL:
1041 		return "BIDI";
1042 	default:
1043 		break;
1044 	}
1045 
1046 	return "UNKNOWN";
1047 }
1048 
1049 void transport_dump_dev_state(
1050 	struct se_device *dev,
1051 	char *b,
1052 	int *bl)
1053 {
1054 	*bl += sprintf(b + *bl, "Status: ");
1055 	if (dev->export_count)
1056 		*bl += sprintf(b + *bl, "ACTIVATED");
1057 	else
1058 		*bl += sprintf(b + *bl, "DEACTIVATED");
1059 
1060 	*bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
1061 	*bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
1062 		dev->dev_attrib.block_size,
1063 		dev->dev_attrib.hw_max_sectors);
1064 	*bl += sprintf(b + *bl, "        ");
1065 }
1066 
1067 void transport_dump_vpd_proto_id(
1068 	struct t10_vpd *vpd,
1069 	unsigned char *p_buf,
1070 	int p_buf_len)
1071 {
1072 	unsigned char buf[VPD_TMP_BUF_SIZE];
1073 	int len;
1074 
1075 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1076 	len = sprintf(buf, "T10 VPD Protocol Identifier: ");
1077 
1078 	switch (vpd->protocol_identifier) {
1079 	case 0x00:
1080 		sprintf(buf+len, "Fibre Channel\n");
1081 		break;
1082 	case 0x10:
1083 		sprintf(buf+len, "Parallel SCSI\n");
1084 		break;
1085 	case 0x20:
1086 		sprintf(buf+len, "SSA\n");
1087 		break;
1088 	case 0x30:
1089 		sprintf(buf+len, "IEEE 1394\n");
1090 		break;
1091 	case 0x40:
1092 		sprintf(buf+len, "SCSI Remote Direct Memory Access"
1093 				" Protocol\n");
1094 		break;
1095 	case 0x50:
1096 		sprintf(buf+len, "Internet SCSI (iSCSI)\n");
1097 		break;
1098 	case 0x60:
1099 		sprintf(buf+len, "SAS Serial SCSI Protocol\n");
1100 		break;
1101 	case 0x70:
1102 		sprintf(buf+len, "Automation/Drive Interface Transport"
1103 				" Protocol\n");
1104 		break;
1105 	case 0x80:
1106 		sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
1107 		break;
1108 	default:
1109 		sprintf(buf+len, "Unknown 0x%02x\n",
1110 				vpd->protocol_identifier);
1111 		break;
1112 	}
1113 
1114 	if (p_buf)
1115 		strncpy(p_buf, buf, p_buf_len);
1116 	else
1117 		pr_debug("%s", buf);
1118 }
1119 
1120 void
1121 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
1122 {
1123 	/*
1124 	 * Check if the Protocol Identifier Valid (PIV) bit is set..
1125 	 *
1126 	 * from spc3r23.pdf section 7.5.1
1127 	 */
1128 	 if (page_83[1] & 0x80) {
1129 		vpd->protocol_identifier = (page_83[0] & 0xf0);
1130 		vpd->protocol_identifier_set = 1;
1131 		transport_dump_vpd_proto_id(vpd, NULL, 0);
1132 	}
1133 }
1134 EXPORT_SYMBOL(transport_set_vpd_proto_id);
1135 
1136 int transport_dump_vpd_assoc(
1137 	struct t10_vpd *vpd,
1138 	unsigned char *p_buf,
1139 	int p_buf_len)
1140 {
1141 	unsigned char buf[VPD_TMP_BUF_SIZE];
1142 	int ret = 0;
1143 	int len;
1144 
1145 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1146 	len = sprintf(buf, "T10 VPD Identifier Association: ");
1147 
1148 	switch (vpd->association) {
1149 	case 0x00:
1150 		sprintf(buf+len, "addressed logical unit\n");
1151 		break;
1152 	case 0x10:
1153 		sprintf(buf+len, "target port\n");
1154 		break;
1155 	case 0x20:
1156 		sprintf(buf+len, "SCSI target device\n");
1157 		break;
1158 	default:
1159 		sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
1160 		ret = -EINVAL;
1161 		break;
1162 	}
1163 
1164 	if (p_buf)
1165 		strncpy(p_buf, buf, p_buf_len);
1166 	else
1167 		pr_debug("%s", buf);
1168 
1169 	return ret;
1170 }
1171 
1172 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
1173 {
1174 	/*
1175 	 * The VPD identification association..
1176 	 *
1177 	 * from spc3r23.pdf Section 7.6.3.1 Table 297
1178 	 */
1179 	vpd->association = (page_83[1] & 0x30);
1180 	return transport_dump_vpd_assoc(vpd, NULL, 0);
1181 }
1182 EXPORT_SYMBOL(transport_set_vpd_assoc);
1183 
1184 int transport_dump_vpd_ident_type(
1185 	struct t10_vpd *vpd,
1186 	unsigned char *p_buf,
1187 	int p_buf_len)
1188 {
1189 	unsigned char buf[VPD_TMP_BUF_SIZE];
1190 	int ret = 0;
1191 	int len;
1192 
1193 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1194 	len = sprintf(buf, "T10 VPD Identifier Type: ");
1195 
1196 	switch (vpd->device_identifier_type) {
1197 	case 0x00:
1198 		sprintf(buf+len, "Vendor specific\n");
1199 		break;
1200 	case 0x01:
1201 		sprintf(buf+len, "T10 Vendor ID based\n");
1202 		break;
1203 	case 0x02:
1204 		sprintf(buf+len, "EUI-64 based\n");
1205 		break;
1206 	case 0x03:
1207 		sprintf(buf+len, "NAA\n");
1208 		break;
1209 	case 0x04:
1210 		sprintf(buf+len, "Relative target port identifier\n");
1211 		break;
1212 	case 0x08:
1213 		sprintf(buf+len, "SCSI name string\n");
1214 		break;
1215 	default:
1216 		sprintf(buf+len, "Unsupported: 0x%02x\n",
1217 				vpd->device_identifier_type);
1218 		ret = -EINVAL;
1219 		break;
1220 	}
1221 
1222 	if (p_buf) {
1223 		if (p_buf_len < strlen(buf)+1)
1224 			return -EINVAL;
1225 		strncpy(p_buf, buf, p_buf_len);
1226 	} else {
1227 		pr_debug("%s", buf);
1228 	}
1229 
1230 	return ret;
1231 }
1232 
1233 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1234 {
1235 	/*
1236 	 * The VPD identifier type..
1237 	 *
1238 	 * from spc3r23.pdf Section 7.6.3.1 Table 298
1239 	 */
1240 	vpd->device_identifier_type = (page_83[1] & 0x0f);
1241 	return transport_dump_vpd_ident_type(vpd, NULL, 0);
1242 }
1243 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1244 
1245 int transport_dump_vpd_ident(
1246 	struct t10_vpd *vpd,
1247 	unsigned char *p_buf,
1248 	int p_buf_len)
1249 {
1250 	unsigned char buf[VPD_TMP_BUF_SIZE];
1251 	int ret = 0;
1252 
1253 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1254 
1255 	switch (vpd->device_identifier_code_set) {
1256 	case 0x01: /* Binary */
1257 		snprintf(buf, sizeof(buf),
1258 			"T10 VPD Binary Device Identifier: %s\n",
1259 			&vpd->device_identifier[0]);
1260 		break;
1261 	case 0x02: /* ASCII */
1262 		snprintf(buf, sizeof(buf),
1263 			"T10 VPD ASCII Device Identifier: %s\n",
1264 			&vpd->device_identifier[0]);
1265 		break;
1266 	case 0x03: /* UTF-8 */
1267 		snprintf(buf, sizeof(buf),
1268 			"T10 VPD UTF-8 Device Identifier: %s\n",
1269 			&vpd->device_identifier[0]);
1270 		break;
1271 	default:
1272 		sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1273 			" 0x%02x", vpd->device_identifier_code_set);
1274 		ret = -EINVAL;
1275 		break;
1276 	}
1277 
1278 	if (p_buf)
1279 		strncpy(p_buf, buf, p_buf_len);
1280 	else
1281 		pr_debug("%s", buf);
1282 
1283 	return ret;
1284 }
1285 
1286 int
1287 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1288 {
1289 	static const char hex_str[] = "0123456789abcdef";
1290 	int j = 0, i = 4; /* offset to start of the identifier */
1291 
1292 	/*
1293 	 * The VPD Code Set (encoding)
1294 	 *
1295 	 * from spc3r23.pdf Section 7.6.3.1 Table 296
1296 	 */
1297 	vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1298 	switch (vpd->device_identifier_code_set) {
1299 	case 0x01: /* Binary */
1300 		vpd->device_identifier[j++] =
1301 				hex_str[vpd->device_identifier_type];
1302 		while (i < (4 + page_83[3])) {
1303 			vpd->device_identifier[j++] =
1304 				hex_str[(page_83[i] & 0xf0) >> 4];
1305 			vpd->device_identifier[j++] =
1306 				hex_str[page_83[i] & 0x0f];
1307 			i++;
1308 		}
1309 		break;
1310 	case 0x02: /* ASCII */
1311 	case 0x03: /* UTF-8 */
1312 		while (i < (4 + page_83[3]))
1313 			vpd->device_identifier[j++] = page_83[i++];
1314 		break;
1315 	default:
1316 		break;
1317 	}
1318 
1319 	return transport_dump_vpd_ident(vpd, NULL, 0);
1320 }
1321 EXPORT_SYMBOL(transport_set_vpd_ident);
1322 
1323 static sense_reason_t
1324 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1325 			       unsigned int size)
1326 {
1327 	u32 mtl;
1328 
1329 	if (!cmd->se_tfo->max_data_sg_nents)
1330 		return TCM_NO_SENSE;
1331 	/*
1332 	 * Check if fabric enforced maximum SGL entries per I/O descriptor
1333 	 * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1334 	 * residual_count and reduce original cmd->data_length to maximum
1335 	 * length based on single PAGE_SIZE entry scatter-lists.
1336 	 */
1337 	mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1338 	if (cmd->data_length > mtl) {
1339 		/*
1340 		 * If an existing CDB overflow is present, calculate new residual
1341 		 * based on CDB size minus fabric maximum transfer length.
1342 		 *
1343 		 * If an existing CDB underflow is present, calculate new residual
1344 		 * based on original cmd->data_length minus fabric maximum transfer
1345 		 * length.
1346 		 *
1347 		 * Otherwise, set the underflow residual based on cmd->data_length
1348 		 * minus fabric maximum transfer length.
1349 		 */
1350 		if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1351 			cmd->residual_count = (size - mtl);
1352 		} else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1353 			u32 orig_dl = size + cmd->residual_count;
1354 			cmd->residual_count = (orig_dl - mtl);
1355 		} else {
1356 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1357 			cmd->residual_count = (cmd->data_length - mtl);
1358 		}
1359 		cmd->data_length = mtl;
1360 		/*
1361 		 * Reset sbc_check_prot() calculated protection payload
1362 		 * length based upon the new smaller MTL.
1363 		 */
1364 		if (cmd->prot_length) {
1365 			u32 sectors = (mtl / dev->dev_attrib.block_size);
1366 			cmd->prot_length = dev->prot_length * sectors;
1367 		}
1368 	}
1369 	return TCM_NO_SENSE;
1370 }
1371 
1372 /**
1373  * target_cmd_size_check - Check whether there will be a residual.
1374  * @cmd: SCSI command.
1375  * @size: Data buffer size derived from CDB. The data buffer size provided by
1376  *   the SCSI transport driver is available in @cmd->data_length.
1377  *
1378  * Compare the data buffer size from the CDB with the data buffer limit from the transport
1379  * header. Set @cmd->residual_count and SCF_OVERFLOW_BIT or SCF_UNDERFLOW_BIT if necessary.
1380  *
1381  * Note: target drivers set @cmd->data_length by calling __target_init_cmd().
1382  *
1383  * Return: TCM_NO_SENSE
1384  */
1385 sense_reason_t
1386 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1387 {
1388 	struct se_device *dev = cmd->se_dev;
1389 
1390 	if (cmd->unknown_data_length) {
1391 		cmd->data_length = size;
1392 	} else if (size != cmd->data_length) {
1393 		pr_warn_ratelimited("TARGET_CORE[%s]: Expected Transfer Length:"
1394 			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
1395 			" 0x%02x\n", cmd->se_tfo->fabric_name,
1396 				cmd->data_length, size, cmd->t_task_cdb[0]);
1397 		/*
1398 		 * For READ command for the overflow case keep the existing
1399 		 * fabric provided ->data_length. Otherwise for the underflow
1400 		 * case, reset ->data_length to the smaller SCSI expected data
1401 		 * transfer length.
1402 		 */
1403 		if (size > cmd->data_length) {
1404 			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1405 			cmd->residual_count = (size - cmd->data_length);
1406 		} else {
1407 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1408 			cmd->residual_count = (cmd->data_length - size);
1409 			/*
1410 			 * Do not truncate ->data_length for WRITE command to
1411 			 * dump all payload
1412 			 */
1413 			if (cmd->data_direction == DMA_FROM_DEVICE) {
1414 				cmd->data_length = size;
1415 			}
1416 		}
1417 
1418 		if (cmd->data_direction == DMA_TO_DEVICE) {
1419 			if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1420 				pr_err_ratelimited("Rejecting underflow/overflow"
1421 						   " for WRITE data CDB\n");
1422 				return TCM_INVALID_FIELD_IN_COMMAND_IU;
1423 			}
1424 			/*
1425 			 * Some fabric drivers like iscsi-target still expect to
1426 			 * always reject overflow writes.  Reject this case until
1427 			 * full fabric driver level support for overflow writes
1428 			 * is introduced tree-wide.
1429 			 */
1430 			if (size > cmd->data_length) {
1431 				pr_err_ratelimited("Rejecting overflow for"
1432 						   " WRITE control CDB\n");
1433 				return TCM_INVALID_CDB_FIELD;
1434 			}
1435 		}
1436 	}
1437 
1438 	return target_check_max_data_sg_nents(cmd, dev, size);
1439 
1440 }
1441 
1442 /*
1443  * Used by fabric modules containing a local struct se_cmd within their
1444  * fabric dependent per I/O descriptor.
1445  *
1446  * Preserves the value of @cmd->tag.
1447  */
1448 void __target_init_cmd(struct se_cmd *cmd,
1449 		       const struct target_core_fabric_ops *tfo,
1450 		       struct se_session *se_sess, u32 data_length,
1451 		       int data_direction, int task_attr,
1452 		       unsigned char *sense_buffer, u64 unpacked_lun,
1453 		       struct target_cmd_counter *cmd_cnt)
1454 {
1455 	INIT_LIST_HEAD(&cmd->se_delayed_node);
1456 	INIT_LIST_HEAD(&cmd->se_qf_node);
1457 	INIT_LIST_HEAD(&cmd->state_list);
1458 	init_completion(&cmd->t_transport_stop_comp);
1459 	cmd->free_compl = NULL;
1460 	cmd->abrt_compl = NULL;
1461 	spin_lock_init(&cmd->t_state_lock);
1462 	INIT_WORK(&cmd->work, NULL);
1463 	kref_init(&cmd->cmd_kref);
1464 
1465 	cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1466 	cmd->se_tfo = tfo;
1467 	cmd->se_sess = se_sess;
1468 	cmd->data_length = data_length;
1469 	cmd->data_direction = data_direction;
1470 	cmd->sam_task_attr = task_attr;
1471 	cmd->sense_buffer = sense_buffer;
1472 	cmd->orig_fe_lun = unpacked_lun;
1473 	cmd->cmd_cnt = cmd_cnt;
1474 
1475 	if (!(cmd->se_cmd_flags & SCF_USE_CPUID))
1476 		cmd->cpuid = raw_smp_processor_id();
1477 
1478 	cmd->state_active = false;
1479 }
1480 EXPORT_SYMBOL(__target_init_cmd);
1481 
1482 static sense_reason_t
1483 transport_check_alloc_task_attr(struct se_cmd *cmd)
1484 {
1485 	struct se_device *dev = cmd->se_dev;
1486 
1487 	/*
1488 	 * Check if SAM Task Attribute emulation is enabled for this
1489 	 * struct se_device storage object
1490 	 */
1491 	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1492 		return 0;
1493 
1494 	if (cmd->sam_task_attr == TCM_ACA_TAG) {
1495 		pr_debug("SAM Task Attribute ACA"
1496 			" emulation is not supported\n");
1497 		return TCM_INVALID_CDB_FIELD;
1498 	}
1499 
1500 	return 0;
1501 }
1502 
1503 sense_reason_t
1504 target_cmd_init_cdb(struct se_cmd *cmd, unsigned char *cdb, gfp_t gfp)
1505 {
1506 	sense_reason_t ret;
1507 
1508 	/*
1509 	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1510 	 * for VARIABLE_LENGTH_CMD
1511 	 */
1512 	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1513 		pr_err("Received SCSI CDB with command_size: %d that"
1514 			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1515 			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1516 		ret = TCM_INVALID_CDB_FIELD;
1517 		goto err;
1518 	}
1519 	/*
1520 	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1521 	 * allocate the additional extended CDB buffer now..  Otherwise
1522 	 * setup the pointer from __t_task_cdb to t_task_cdb.
1523 	 */
1524 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1525 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb), gfp);
1526 		if (!cmd->t_task_cdb) {
1527 			pr_err("Unable to allocate cmd->t_task_cdb"
1528 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1529 				scsi_command_size(cdb),
1530 				(unsigned long)sizeof(cmd->__t_task_cdb));
1531 			ret = TCM_OUT_OF_RESOURCES;
1532 			goto err;
1533 		}
1534 	}
1535 	/*
1536 	 * Copy the original CDB into cmd->
1537 	 */
1538 	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1539 
1540 	trace_target_sequencer_start(cmd);
1541 	return 0;
1542 
1543 err:
1544 	/*
1545 	 * Copy the CDB here to allow trace_target_cmd_complete() to
1546 	 * print the cdb to the trace buffers.
1547 	 */
1548 	memcpy(cmd->t_task_cdb, cdb, min(scsi_command_size(cdb),
1549 					 (unsigned int)TCM_MAX_COMMAND_SIZE));
1550 	return ret;
1551 }
1552 EXPORT_SYMBOL(target_cmd_init_cdb);
1553 
1554 sense_reason_t
1555 target_cmd_parse_cdb(struct se_cmd *cmd)
1556 {
1557 	struct se_device *dev = cmd->se_dev;
1558 	sense_reason_t ret;
1559 
1560 	ret = dev->transport->parse_cdb(cmd);
1561 	if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1562 		pr_debug_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1563 				     cmd->se_tfo->fabric_name,
1564 				     cmd->se_sess->se_node_acl->initiatorname,
1565 				     cmd->t_task_cdb[0]);
1566 	if (ret)
1567 		return ret;
1568 
1569 	ret = transport_check_alloc_task_attr(cmd);
1570 	if (ret)
1571 		return ret;
1572 
1573 	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1574 	atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1575 	return 0;
1576 }
1577 EXPORT_SYMBOL(target_cmd_parse_cdb);
1578 
1579 static int __target_submit(struct se_cmd *cmd)
1580 {
1581 	sense_reason_t ret;
1582 
1583 	might_sleep();
1584 
1585 	/*
1586 	 * Check if we need to delay processing because of ALUA
1587 	 * Active/NonOptimized primary access state..
1588 	 */
1589 	core_alua_check_nonop_delay(cmd);
1590 
1591 	if (cmd->t_data_nents != 0) {
1592 		/*
1593 		 * This is primarily a hack for udev and tcm loop which sends
1594 		 * INQUIRYs with a single page and expects the data to be
1595 		 * cleared.
1596 		 */
1597 		if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1598 		    cmd->data_direction == DMA_FROM_DEVICE) {
1599 			struct scatterlist *sgl = cmd->t_data_sg;
1600 			unsigned char *buf = NULL;
1601 
1602 			BUG_ON(!sgl);
1603 
1604 			buf = kmap_local_page(sg_page(sgl));
1605 			if (buf) {
1606 				memset(buf + sgl->offset, 0, sgl->length);
1607 				kunmap_local(buf);
1608 			}
1609 		}
1610 	}
1611 
1612 	if (!cmd->se_lun) {
1613 		dump_stack();
1614 		pr_err("cmd->se_lun is NULL\n");
1615 		return -EINVAL;
1616 	}
1617 
1618 	/*
1619 	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1620 	 * outstanding descriptors are handled correctly during shutdown via
1621 	 * transport_wait_for_tasks()
1622 	 *
1623 	 * Also, we don't take cmd->t_state_lock here as we only expect
1624 	 * this to be called for initial descriptor submission.
1625 	 */
1626 	cmd->t_state = TRANSPORT_NEW_CMD;
1627 	cmd->transport_state |= CMD_T_ACTIVE;
1628 
1629 	/*
1630 	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1631 	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1632 	 * and call transport_generic_request_failure() if necessary..
1633 	 */
1634 	ret = transport_generic_new_cmd(cmd);
1635 	if (ret)
1636 		transport_generic_request_failure(cmd, ret);
1637 	return 0;
1638 }
1639 
1640 sense_reason_t
1641 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1642 		u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1643 {
1644 	if (!sgl || !sgl_count)
1645 		return 0;
1646 
1647 	/*
1648 	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1649 	 * scatterlists already have been set to follow what the fabric
1650 	 * passes for the original expected data transfer length.
1651 	 */
1652 	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1653 		pr_warn("Rejecting SCSI DATA overflow for fabric using"
1654 			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1655 		return TCM_INVALID_CDB_FIELD;
1656 	}
1657 
1658 	cmd->t_data_sg = sgl;
1659 	cmd->t_data_nents = sgl_count;
1660 	cmd->t_bidi_data_sg = sgl_bidi;
1661 	cmd->t_bidi_data_nents = sgl_bidi_count;
1662 
1663 	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1664 	return 0;
1665 }
1666 
1667 /**
1668  * target_init_cmd - initialize se_cmd
1669  * @se_cmd: command descriptor to init
1670  * @se_sess: associated se_sess for endpoint
1671  * @sense: pointer to SCSI sense buffer
1672  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1673  * @data_length: fabric expected data transfer length
1674  * @task_attr: SAM task attribute
1675  * @data_dir: DMA data direction
1676  * @flags: flags for command submission from target_sc_flags_tables
1677  *
1678  * Task tags are supported if the caller has set @se_cmd->tag.
1679  *
1680  * Returns:
1681  *	- less than zero to signal active I/O shutdown failure.
1682  *	- zero on success.
1683  *
1684  * If the fabric driver calls target_stop_session, then it must check the
1685  * return code and handle failures. This will never fail for other drivers,
1686  * and the return code can be ignored.
1687  */
1688 int target_init_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1689 		    unsigned char *sense, u64 unpacked_lun,
1690 		    u32 data_length, int task_attr, int data_dir, int flags)
1691 {
1692 	struct se_portal_group *se_tpg;
1693 
1694 	se_tpg = se_sess->se_tpg;
1695 	BUG_ON(!se_tpg);
1696 	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1697 
1698 	if (flags & TARGET_SCF_USE_CPUID)
1699 		se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1700 	/*
1701 	 * Signal bidirectional data payloads to target-core
1702 	 */
1703 	if (flags & TARGET_SCF_BIDI_OP)
1704 		se_cmd->se_cmd_flags |= SCF_BIDI;
1705 
1706 	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1707 		se_cmd->unknown_data_length = 1;
1708 	/*
1709 	 * Initialize se_cmd for target operation.  From this point
1710 	 * exceptions are handled by sending exception status via
1711 	 * target_core_fabric_ops->queue_status() callback
1712 	 */
1713 	__target_init_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, data_length,
1714 			  data_dir, task_attr, sense, unpacked_lun,
1715 			  se_sess->cmd_cnt);
1716 
1717 	/*
1718 	 * Obtain struct se_cmd->cmd_kref reference. A second kref_get here is
1719 	 * necessary for fabrics using TARGET_SCF_ACK_KREF that expect a second
1720 	 * kref_put() to happen during fabric packet acknowledgement.
1721 	 */
1722 	return target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1723 }
1724 EXPORT_SYMBOL_GPL(target_init_cmd);
1725 
1726 /**
1727  * target_submit_prep - prepare cmd for submission
1728  * @se_cmd: command descriptor to prep
1729  * @cdb: pointer to SCSI CDB
1730  * @sgl: struct scatterlist memory for unidirectional mapping
1731  * @sgl_count: scatterlist count for unidirectional mapping
1732  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1733  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1734  * @sgl_prot: struct scatterlist memory protection information
1735  * @sgl_prot_count: scatterlist count for protection information
1736  * @gfp: gfp allocation type
1737  *
1738  * Returns:
1739  *	- less than zero to signal failure.
1740  *	- zero on success.
1741  *
1742  * If failure is returned, lio will the callers queue_status to complete
1743  * the cmd.
1744  */
1745 int target_submit_prep(struct se_cmd *se_cmd, unsigned char *cdb,
1746 		       struct scatterlist *sgl, u32 sgl_count,
1747 		       struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1748 		       struct scatterlist *sgl_prot, u32 sgl_prot_count,
1749 		       gfp_t gfp)
1750 {
1751 	sense_reason_t rc;
1752 
1753 	rc = target_cmd_init_cdb(se_cmd, cdb, gfp);
1754 	if (rc)
1755 		goto send_cc_direct;
1756 
1757 	/*
1758 	 * Locate se_lun pointer and attach it to struct se_cmd
1759 	 */
1760 	rc = transport_lookup_cmd_lun(se_cmd);
1761 	if (rc)
1762 		goto send_cc_direct;
1763 
1764 	rc = target_cmd_parse_cdb(se_cmd);
1765 	if (rc != 0)
1766 		goto generic_fail;
1767 
1768 	/*
1769 	 * Save pointers for SGLs containing protection information,
1770 	 * if present.
1771 	 */
1772 	if (sgl_prot_count) {
1773 		se_cmd->t_prot_sg = sgl_prot;
1774 		se_cmd->t_prot_nents = sgl_prot_count;
1775 		se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1776 	}
1777 
1778 	/*
1779 	 * When a non zero sgl_count has been passed perform SGL passthrough
1780 	 * mapping for pre-allocated fabric memory instead of having target
1781 	 * core perform an internal SGL allocation..
1782 	 */
1783 	if (sgl_count != 0) {
1784 		BUG_ON(!sgl);
1785 
1786 		rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1787 				sgl_bidi, sgl_bidi_count);
1788 		if (rc != 0)
1789 			goto generic_fail;
1790 	}
1791 
1792 	return 0;
1793 
1794 send_cc_direct:
1795 	transport_send_check_condition_and_sense(se_cmd, rc, 0);
1796 	target_put_sess_cmd(se_cmd);
1797 	return -EIO;
1798 
1799 generic_fail:
1800 	transport_generic_request_failure(se_cmd, rc);
1801 	return -EIO;
1802 }
1803 EXPORT_SYMBOL_GPL(target_submit_prep);
1804 
1805 /**
1806  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1807  *
1808  * @se_cmd: command descriptor to submit
1809  * @se_sess: associated se_sess for endpoint
1810  * @cdb: pointer to SCSI CDB
1811  * @sense: pointer to SCSI sense buffer
1812  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1813  * @data_length: fabric expected data transfer length
1814  * @task_attr: SAM task attribute
1815  * @data_dir: DMA data direction
1816  * @flags: flags for command submission from target_sc_flags_tables
1817  *
1818  * Task tags are supported if the caller has set @se_cmd->tag.
1819  *
1820  * This may only be called from process context, and also currently
1821  * assumes internal allocation of fabric payload buffer by target-core.
1822  *
1823  * It also assumes interal target core SGL memory allocation.
1824  *
1825  * This function must only be used by drivers that do their own
1826  * sync during shutdown and does not use target_stop_session. If there
1827  * is a failure this function will call into the fabric driver's
1828  * queue_status with a CHECK_CONDITION.
1829  */
1830 void target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1831 		unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1832 		u32 data_length, int task_attr, int data_dir, int flags)
1833 {
1834 	int rc;
1835 
1836 	rc = target_init_cmd(se_cmd, se_sess, sense, unpacked_lun, data_length,
1837 			     task_attr, data_dir, flags);
1838 	WARN(rc, "Invalid target_submit_cmd use. Driver must not use target_stop_session or call target_init_cmd directly.\n");
1839 	if (rc)
1840 		return;
1841 
1842 	if (target_submit_prep(se_cmd, cdb, NULL, 0, NULL, 0, NULL, 0,
1843 			       GFP_KERNEL))
1844 		return;
1845 
1846 	target_submit(se_cmd);
1847 }
1848 EXPORT_SYMBOL(target_submit_cmd);
1849 
1850 
1851 static struct se_dev_plug *target_plug_device(struct se_device *se_dev)
1852 {
1853 	struct se_dev_plug *se_plug;
1854 
1855 	if (!se_dev->transport->plug_device)
1856 		return NULL;
1857 
1858 	se_plug = se_dev->transport->plug_device(se_dev);
1859 	if (!se_plug)
1860 		return NULL;
1861 
1862 	se_plug->se_dev = se_dev;
1863 	/*
1864 	 * We have a ref to the lun at this point, but the cmds could
1865 	 * complete before we unplug, so grab a ref to the se_device so we
1866 	 * can call back into the backend.
1867 	 */
1868 	config_group_get(&se_dev->dev_group);
1869 	return se_plug;
1870 }
1871 
1872 static void target_unplug_device(struct se_dev_plug *se_plug)
1873 {
1874 	struct se_device *se_dev = se_plug->se_dev;
1875 
1876 	se_dev->transport->unplug_device(se_plug);
1877 	config_group_put(&se_dev->dev_group);
1878 }
1879 
1880 void target_queued_submit_work(struct work_struct *work)
1881 {
1882 	struct se_cmd_queue *sq = container_of(work, struct se_cmd_queue, work);
1883 	struct se_cmd *se_cmd, *next_cmd;
1884 	struct se_dev_plug *se_plug = NULL;
1885 	struct se_device *se_dev = NULL;
1886 	struct llist_node *cmd_list;
1887 
1888 	cmd_list = llist_del_all(&sq->cmd_list);
1889 	if (!cmd_list)
1890 		/* Previous call took what we were queued to submit */
1891 		return;
1892 
1893 	cmd_list = llist_reverse_order(cmd_list);
1894 	llist_for_each_entry_safe(se_cmd, next_cmd, cmd_list, se_cmd_list) {
1895 		if (!se_dev) {
1896 			se_dev = se_cmd->se_dev;
1897 			se_plug = target_plug_device(se_dev);
1898 		}
1899 
1900 		__target_submit(se_cmd);
1901 	}
1902 
1903 	if (se_plug)
1904 		target_unplug_device(se_plug);
1905 }
1906 
1907 /**
1908  * target_queue_submission - queue the cmd to run on the LIO workqueue
1909  * @se_cmd: command descriptor to submit
1910  */
1911 static void target_queue_submission(struct se_cmd *se_cmd)
1912 {
1913 	struct se_device *se_dev = se_cmd->se_dev;
1914 	int cpu = se_cmd->cpuid;
1915 	struct se_cmd_queue *sq;
1916 
1917 	sq = &se_dev->queues[cpu].sq;
1918 	llist_add(&se_cmd->se_cmd_list, &sq->cmd_list);
1919 	queue_work_on(cpu, target_submission_wq, &sq->work);
1920 }
1921 
1922 /**
1923  * target_submit - perform final initialization and submit cmd to LIO core
1924  * @se_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->se_dev->se_tmr_lock, flags);
3633 	list_add_tail(&cmd->se_tmr_req->tmr_list, &cmd->se_dev->dev_tmr_list);
3634 	spin_unlock_irqrestore(&cmd->se_dev->se_tmr_lock, flags);
3635 
3636 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3637 	if (cmd->transport_state & CMD_T_ABORTED) {
3638 		aborted = true;
3639 	} else {
3640 		cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3641 		cmd->transport_state |= CMD_T_ACTIVE;
3642 	}
3643 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3644 
3645 	if (aborted) {
3646 		pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d ref_tag: %llu tag: %llu\n",
3647 				    cmd->se_tmr_req->function,
3648 				    cmd->se_tmr_req->ref_task_tag, cmd->tag);
3649 		target_handle_abort(cmd);
3650 		return 0;
3651 	}
3652 
3653 	INIT_WORK(&cmd->work, target_tmr_work);
3654 	schedule_work(&cmd->work);
3655 	return 0;
3656 }
3657 EXPORT_SYMBOL(transport_generic_handle_tmr);
3658 
3659 bool
3660 target_check_wce(struct se_device *dev)
3661 {
3662 	bool wce = false;
3663 
3664 	if (dev->transport->get_write_cache)
3665 		wce = dev->transport->get_write_cache(dev);
3666 	else if (dev->dev_attrib.emulate_write_cache > 0)
3667 		wce = true;
3668 
3669 	return wce;
3670 }
3671 
3672 bool
3673 target_check_fua(struct se_device *dev)
3674 {
3675 	return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3676 }
3677