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