xref: /linux/drivers/target/target_core_transport.c (revision 87e801e1678342fc23b1eb92c0eecedf5dca79cb)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*******************************************************************************
3  * Filename:  target_core_transport.c
4  *
5  * This file contains the Generic Target Engine Core.
6  *
7  * (c) Copyright 2002-2013 Datera, Inc.
8  *
9  * Nicholas A. Bellinger <nab@kernel.org>
10  *
11  ******************************************************************************/
12 
13 #include <linux/net.h>
14 #include <linux/delay.h>
15 #include <linux/string.h>
16 #include <linux/timer.h>
17 #include <linux/slab.h>
18 #include <linux/spinlock.h>
19 #include <linux/kthread.h>
20 #include <linux/in.h>
21 #include <linux/cdrom.h>
22 #include <linux/module.h>
23 #include <linux/ratelimit.h>
24 #include <linux/vmalloc.h>
25 #include <linux/unaligned.h>
26 #include <net/sock.h>
27 #include <net/tcp.h>
28 #include <scsi/scsi_proto.h>
29 #include <scsi/scsi_common.h>
30 
31 #include <target/target_core_base.h>
32 #include <target/target_core_backend.h>
33 #include <target/target_core_fabric.h>
34 
35 #include "target_core_internal.h"
36 #include "target_core_alua.h"
37 #include "target_core_pr.h"
38 #include "target_core_ua.h"
39 
40 #define CREATE_TRACE_POINTS
41 #include <trace/events/target.h>
42 
43 static struct workqueue_struct *target_completion_wq;
44 static struct workqueue_struct *target_submission_wq;
45 static struct kmem_cache *se_sess_cache;
46 struct kmem_cache *se_ua_cache;
47 struct kmem_cache *t10_pr_reg_cache;
48 struct kmem_cache *t10_alua_lu_gp_cache;
49 struct kmem_cache *t10_alua_lu_gp_mem_cache;
50 struct kmem_cache *t10_alua_tg_pt_gp_cache;
51 struct kmem_cache *t10_alua_lba_map_cache;
52 struct kmem_cache *t10_alua_lba_map_mem_cache;
53 
54 static void transport_complete_task_attr(struct se_cmd *cmd);
55 static void translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason);
56 static void transport_handle_queue_full(struct se_cmd *cmd,
57 		struct se_device *dev, int err, bool write_pending);
58 static void target_complete_ok_work(struct work_struct *work);
59 
60 int init_se_kmem_caches(void)
61 {
62 	se_sess_cache = kmem_cache_create("se_sess_cache",
63 			sizeof(struct se_session), __alignof__(struct se_session),
64 			0, NULL);
65 	if (!se_sess_cache) {
66 		pr_err("kmem_cache_create() for struct se_session"
67 				" failed\n");
68 		goto out;
69 	}
70 	se_ua_cache = kmem_cache_create("se_ua_cache",
71 			sizeof(struct se_ua), __alignof__(struct se_ua),
72 			0, NULL);
73 	if (!se_ua_cache) {
74 		pr_err("kmem_cache_create() for struct se_ua failed\n");
75 		goto out_free_sess_cache;
76 	}
77 	t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
78 			sizeof(struct t10_pr_registration),
79 			__alignof__(struct t10_pr_registration), 0, NULL);
80 	if (!t10_pr_reg_cache) {
81 		pr_err("kmem_cache_create() for struct t10_pr_registration"
82 				" failed\n");
83 		goto out_free_ua_cache;
84 	}
85 	t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
86 			sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
87 			0, NULL);
88 	if (!t10_alua_lu_gp_cache) {
89 		pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
90 				" failed\n");
91 		goto out_free_pr_reg_cache;
92 	}
93 	t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
94 			sizeof(struct t10_alua_lu_gp_member),
95 			__alignof__(struct t10_alua_lu_gp_member), 0, NULL);
96 	if (!t10_alua_lu_gp_mem_cache) {
97 		pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
98 				"cache failed\n");
99 		goto out_free_lu_gp_cache;
100 	}
101 	t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
102 			sizeof(struct t10_alua_tg_pt_gp),
103 			__alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
104 	if (!t10_alua_tg_pt_gp_cache) {
105 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
106 				"cache failed\n");
107 		goto out_free_lu_gp_mem_cache;
108 	}
109 	t10_alua_lba_map_cache = kmem_cache_create(
110 			"t10_alua_lba_map_cache",
111 			sizeof(struct t10_alua_lba_map),
112 			__alignof__(struct t10_alua_lba_map), 0, NULL);
113 	if (!t10_alua_lba_map_cache) {
114 		pr_err("kmem_cache_create() for t10_alua_lba_map_"
115 				"cache failed\n");
116 		goto out_free_tg_pt_gp_cache;
117 	}
118 	t10_alua_lba_map_mem_cache = kmem_cache_create(
119 			"t10_alua_lba_map_mem_cache",
120 			sizeof(struct t10_alua_lba_map_member),
121 			__alignof__(struct t10_alua_lba_map_member), 0, NULL);
122 	if (!t10_alua_lba_map_mem_cache) {
123 		pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
124 				"cache failed\n");
125 		goto out_free_lba_map_cache;
126 	}
127 
128 	target_completion_wq = alloc_workqueue("target_completion",
129 					       WQ_MEM_RECLAIM | WQ_PERCPU, 0);
130 	if (!target_completion_wq)
131 		goto out_free_lba_map_mem_cache;
132 
133 	target_submission_wq = alloc_workqueue("target_submission",
134 					       WQ_MEM_RECLAIM | WQ_PERCPU, 0);
135 	if (!target_submission_wq)
136 		goto out_free_completion_wq;
137 
138 	return 0;
139 
140 out_free_completion_wq:
141 	destroy_workqueue(target_completion_wq);
142 out_free_lba_map_mem_cache:
143 	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
144 out_free_lba_map_cache:
145 	kmem_cache_destroy(t10_alua_lba_map_cache);
146 out_free_tg_pt_gp_cache:
147 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
148 out_free_lu_gp_mem_cache:
149 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
150 out_free_lu_gp_cache:
151 	kmem_cache_destroy(t10_alua_lu_gp_cache);
152 out_free_pr_reg_cache:
153 	kmem_cache_destroy(t10_pr_reg_cache);
154 out_free_ua_cache:
155 	kmem_cache_destroy(se_ua_cache);
156 out_free_sess_cache:
157 	kmem_cache_destroy(se_sess_cache);
158 out:
159 	return -ENOMEM;
160 }
161 
162 void release_se_kmem_caches(void)
163 {
164 	destroy_workqueue(target_submission_wq);
165 	destroy_workqueue(target_completion_wq);
166 	kmem_cache_destroy(se_sess_cache);
167 	kmem_cache_destroy(se_ua_cache);
168 	kmem_cache_destroy(t10_pr_reg_cache);
169 	kmem_cache_destroy(t10_alua_lu_gp_cache);
170 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
171 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
172 	kmem_cache_destroy(t10_alua_lba_map_cache);
173 	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
174 }
175 
176 /* This code ensures unique mib indexes are handed out. */
177 static DEFINE_SPINLOCK(scsi_mib_index_lock);
178 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
179 
180 /*
181  * Allocate a new row index for the entry type specified
182  */
183 u32 scsi_get_new_index(scsi_index_t type)
184 {
185 	u32 new_index;
186 
187 	BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
188 
189 	spin_lock(&scsi_mib_index_lock);
190 	new_index = ++scsi_mib_index[type];
191 	spin_unlock(&scsi_mib_index_lock);
192 
193 	return new_index;
194 }
195 
196 void transport_subsystem_check_init(void)
197 {
198 	int ret;
199 	static int sub_api_initialized;
200 
201 	if (sub_api_initialized)
202 		return;
203 
204 	ret = IS_ENABLED(CONFIG_TCM_IBLOCK) && request_module("target_core_iblock");
205 	if (ret != 0)
206 		pr_err("Unable to load target_core_iblock\n");
207 
208 	ret = IS_ENABLED(CONFIG_TCM_FILEIO) && request_module("target_core_file");
209 	if (ret != 0)
210 		pr_err("Unable to load target_core_file\n");
211 
212 	ret = IS_ENABLED(CONFIG_TCM_PSCSI) && request_module("target_core_pscsi");
213 	if (ret != 0)
214 		pr_err("Unable to load target_core_pscsi\n");
215 
216 	ret = IS_ENABLED(CONFIG_TCM_USER2) && request_module("target_core_user");
217 	if (ret != 0)
218 		pr_err("Unable to load target_core_user\n");
219 
220 	sub_api_initialized = 1;
221 }
222 
223 static void target_release_cmd_refcnt(struct percpu_ref *ref)
224 {
225 	struct target_cmd_counter *cmd_cnt  = container_of(ref,
226 							   typeof(*cmd_cnt),
227 							   refcnt);
228 	wake_up(&cmd_cnt->refcnt_wq);
229 }
230 
231 struct target_cmd_counter *target_alloc_cmd_counter(void)
232 {
233 	struct target_cmd_counter *cmd_cnt;
234 	int rc;
235 
236 	cmd_cnt = kzalloc_obj(*cmd_cnt);
237 	if (!cmd_cnt)
238 		return NULL;
239 
240 	init_completion(&cmd_cnt->stop_done);
241 	init_waitqueue_head(&cmd_cnt->refcnt_wq);
242 	atomic_set(&cmd_cnt->stopped, 0);
243 
244 	rc = percpu_ref_init(&cmd_cnt->refcnt, target_release_cmd_refcnt, 0,
245 			     GFP_KERNEL);
246 	if (rc)
247 		goto free_cmd_cnt;
248 
249 	return cmd_cnt;
250 
251 free_cmd_cnt:
252 	kfree(cmd_cnt);
253 	return NULL;
254 }
255 EXPORT_SYMBOL_GPL(target_alloc_cmd_counter);
256 
257 void target_free_cmd_counter(struct target_cmd_counter *cmd_cnt)
258 {
259 	/*
260 	 * Drivers like loop do not call target_stop_session during session
261 	 * shutdown so we have to drop the ref taken at init time here.
262 	 */
263 	if (!atomic_read(&cmd_cnt->stopped))
264 		percpu_ref_put(&cmd_cnt->refcnt);
265 
266 	percpu_ref_exit(&cmd_cnt->refcnt);
267 	kfree(cmd_cnt);
268 }
269 EXPORT_SYMBOL_GPL(target_free_cmd_counter);
270 
271 /**
272  * transport_init_session - initialize a session object
273  * @se_sess: Session object pointer.
274  *
275  * The caller must have zero-initialized @se_sess before calling this function.
276  */
277 void transport_init_session(struct se_session *se_sess)
278 {
279 	INIT_LIST_HEAD(&se_sess->sess_list);
280 	INIT_LIST_HEAD(&se_sess->sess_acl_list);
281 	spin_lock_init(&se_sess->sess_cmd_lock);
282 }
283 EXPORT_SYMBOL(transport_init_session);
284 
285 /**
286  * transport_alloc_session - allocate a session object and initialize it
287  * @sup_prot_ops: bitmask that defines which T10-PI modes are supported.
288  */
289 struct se_session *transport_alloc_session(enum target_prot_op sup_prot_ops)
290 {
291 	struct se_session *se_sess;
292 
293 	se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
294 	if (!se_sess) {
295 		pr_err("Unable to allocate struct se_session from"
296 				" se_sess_cache\n");
297 		return ERR_PTR(-ENOMEM);
298 	}
299 	transport_init_session(se_sess);
300 	se_sess->sup_prot_ops = sup_prot_ops;
301 
302 	return se_sess;
303 }
304 EXPORT_SYMBOL(transport_alloc_session);
305 
306 /**
307  * transport_alloc_session_tags - allocate target driver private data
308  * @se_sess:  Session pointer.
309  * @tag_num:  Maximum number of in-flight commands between initiator and target.
310  * @tag_size: Size in bytes of the private data a target driver associates with
311  *	      each command.
312  */
313 int transport_alloc_session_tags(struct se_session *se_sess,
314 			         unsigned int tag_num, unsigned int tag_size)
315 {
316 	int rc;
317 
318 	se_sess->sess_cmd_map = kvcalloc(tag_size, tag_num,
319 					 GFP_KERNEL | __GFP_RETRY_MAYFAIL);
320 	if (!se_sess->sess_cmd_map) {
321 		pr_err("Unable to allocate se_sess->sess_cmd_map\n");
322 		return -ENOMEM;
323 	}
324 
325 	rc = sbitmap_queue_init_node(&se_sess->sess_tag_pool, tag_num, -1,
326 			false, GFP_KERNEL, NUMA_NO_NODE);
327 	if (rc < 0) {
328 		pr_err("Unable to init se_sess->sess_tag_pool,"
329 			" tag_num: %u\n", tag_num);
330 		kvfree(se_sess->sess_cmd_map);
331 		se_sess->sess_cmd_map = NULL;
332 		return -ENOMEM;
333 	}
334 
335 	return 0;
336 }
337 EXPORT_SYMBOL(transport_alloc_session_tags);
338 
339 /**
340  * transport_init_session_tags - allocate a session and target driver private data
341  * @tag_num:  Maximum number of in-flight commands between initiator and target.
342  * @tag_size: Size in bytes of the private data a target driver associates with
343  *	      each command.
344  * @sup_prot_ops: bitmask that defines which T10-PI modes are supported.
345  */
346 static struct se_session *
347 transport_init_session_tags(unsigned int tag_num, unsigned int tag_size,
348 			    enum target_prot_op sup_prot_ops)
349 {
350 	struct se_session *se_sess;
351 	int rc;
352 
353 	if (tag_num != 0 && !tag_size) {
354 		pr_err("init_session_tags called with percpu-ida tag_num:"
355 		       " %u, but zero tag_size\n", tag_num);
356 		return ERR_PTR(-EINVAL);
357 	}
358 	if (!tag_num && tag_size) {
359 		pr_err("init_session_tags called with percpu-ida tag_size:"
360 		       " %u, but zero tag_num\n", tag_size);
361 		return ERR_PTR(-EINVAL);
362 	}
363 
364 	se_sess = transport_alloc_session(sup_prot_ops);
365 	if (IS_ERR(se_sess))
366 		return se_sess;
367 
368 	rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
369 	if (rc < 0) {
370 		transport_free_session(se_sess);
371 		return ERR_PTR(-ENOMEM);
372 	}
373 
374 	return se_sess;
375 }
376 
377 /*
378  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
379  */
380 void __transport_register_session(
381 	struct se_portal_group *se_tpg,
382 	struct se_node_acl *se_nacl,
383 	struct se_session *se_sess,
384 	void *fabric_sess_ptr)
385 {
386 	const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
387 	unsigned char buf[PR_REG_ISID_LEN];
388 	unsigned long flags;
389 
390 	se_sess->se_tpg = se_tpg;
391 	se_sess->fabric_sess_ptr = fabric_sess_ptr;
392 	/*
393 	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
394 	 *
395 	 * Only set for struct se_session's that will actually be moving I/O.
396 	 * eg: *NOT* discovery sessions.
397 	 */
398 	if (se_nacl) {
399 		/*
400 		 *
401 		 * Determine if fabric allows for T10-PI feature bits exposed to
402 		 * initiators for device backends with !dev->dev_attrib.pi_prot_type.
403 		 *
404 		 * If so, then always save prot_type on a per se_node_acl node
405 		 * basis and re-instate the previous sess_prot_type to avoid
406 		 * disabling PI from below any previously initiator side
407 		 * registered LUNs.
408 		 */
409 		if (se_nacl->saved_prot_type)
410 			se_sess->sess_prot_type = se_nacl->saved_prot_type;
411 		else if (tfo->tpg_check_prot_fabric_only)
412 			se_sess->sess_prot_type = se_nacl->saved_prot_type =
413 					tfo->tpg_check_prot_fabric_only(se_tpg);
414 		/*
415 		 * If the fabric module supports an ISID based TransportID,
416 		 * save this value in binary from the fabric I_T Nexus now.
417 		 */
418 		if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
419 			memset(&buf[0], 0, PR_REG_ISID_LEN);
420 			se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
421 					&buf[0], PR_REG_ISID_LEN);
422 			se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
423 		}
424 
425 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
426 		/*
427 		 * The se_nacl->nacl_sess pointer will be set to the
428 		 * last active I_T Nexus for each struct se_node_acl.
429 		 */
430 		se_nacl->nacl_sess = se_sess;
431 
432 		list_add_tail(&se_sess->sess_acl_list,
433 			      &se_nacl->acl_sess_list);
434 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
435 	}
436 	list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
437 
438 	pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
439 		se_tpg->se_tpg_tfo->fabric_name, se_sess->fabric_sess_ptr);
440 }
441 EXPORT_SYMBOL(__transport_register_session);
442 
443 void transport_register_session(
444 	struct se_portal_group *se_tpg,
445 	struct se_node_acl *se_nacl,
446 	struct se_session *se_sess,
447 	void *fabric_sess_ptr)
448 {
449 	unsigned long flags;
450 
451 	spin_lock_irqsave(&se_tpg->session_lock, flags);
452 	__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
453 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
454 }
455 EXPORT_SYMBOL(transport_register_session);
456 
457 struct se_session *
458 target_setup_session(struct se_portal_group *tpg,
459 		     unsigned int tag_num, unsigned int tag_size,
460 		     enum target_prot_op prot_op,
461 		     const char *initiatorname, void *private,
462 		     int (*callback)(struct se_portal_group *,
463 				     struct se_session *, void *))
464 {
465 	struct target_cmd_counter *cmd_cnt;
466 	struct se_session *sess;
467 	int rc;
468 
469 	cmd_cnt = target_alloc_cmd_counter();
470 	if (!cmd_cnt)
471 		return ERR_PTR(-ENOMEM);
472 	/*
473 	 * If the fabric driver is using percpu-ida based pre allocation
474 	 * of I/O descriptor tags, go ahead and perform that setup now..
475 	 */
476 	if (tag_num != 0)
477 		sess = transport_init_session_tags(tag_num, tag_size, prot_op);
478 	else
479 		sess = transport_alloc_session(prot_op);
480 
481 	if (IS_ERR(sess)) {
482 		rc = PTR_ERR(sess);
483 		goto free_cnt;
484 	}
485 	sess->cmd_cnt = cmd_cnt;
486 
487 	sess->se_node_acl = core_tpg_check_initiator_node_acl(tpg,
488 					(unsigned char *)initiatorname);
489 	if (!sess->se_node_acl) {
490 		rc = -EACCES;
491 		goto free_sess;
492 	}
493 	/*
494 	 * Go ahead and perform any remaining fabric setup that is
495 	 * required before transport_register_session().
496 	 */
497 	if (callback != NULL) {
498 		rc = callback(tpg, sess, private);
499 		if (rc)
500 			goto free_sess;
501 	}
502 
503 	transport_register_session(tpg, sess->se_node_acl, sess, private);
504 	return sess;
505 
506 free_sess:
507 	transport_free_session(sess);
508 	return ERR_PTR(rc);
509 
510 free_cnt:
511 	target_free_cmd_counter(cmd_cnt);
512 	return ERR_PTR(rc);
513 }
514 EXPORT_SYMBOL(target_setup_session);
515 
516 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
517 {
518 	struct se_session *se_sess;
519 	ssize_t len = 0;
520 
521 	spin_lock_bh(&se_tpg->session_lock);
522 	list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
523 		if (!se_sess->se_node_acl)
524 			continue;
525 		if (!se_sess->se_node_acl->dynamic_node_acl)
526 			continue;
527 		if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
528 			break;
529 
530 		len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
531 				se_sess->se_node_acl->initiatorname);
532 		len += 1; /* Include NULL terminator */
533 	}
534 	spin_unlock_bh(&se_tpg->session_lock);
535 
536 	return len;
537 }
538 EXPORT_SYMBOL(target_show_dynamic_sessions);
539 
540 static void target_complete_nacl(struct kref *kref)
541 {
542 	struct se_node_acl *nacl = container_of(kref,
543 				struct se_node_acl, acl_kref);
544 	struct se_portal_group *se_tpg = nacl->se_tpg;
545 
546 	if (!nacl->dynamic_stop) {
547 		complete(&nacl->acl_free_comp);
548 		return;
549 	}
550 
551 	mutex_lock(&se_tpg->acl_node_mutex);
552 	list_del_init(&nacl->acl_list);
553 	mutex_unlock(&se_tpg->acl_node_mutex);
554 
555 	core_tpg_wait_for_nacl_pr_ref(nacl);
556 	core_free_device_list_for_node(nacl, se_tpg);
557 	kfree(nacl);
558 }
559 
560 void target_put_nacl(struct se_node_acl *nacl)
561 {
562 	kref_put(&nacl->acl_kref, target_complete_nacl);
563 }
564 EXPORT_SYMBOL(target_put_nacl);
565 
566 void transport_deregister_session_configfs(struct se_session *se_sess)
567 {
568 	struct se_node_acl *se_nacl;
569 	unsigned long flags;
570 	/*
571 	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
572 	 */
573 	se_nacl = se_sess->se_node_acl;
574 	if (se_nacl) {
575 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
576 		if (!list_empty(&se_sess->sess_acl_list))
577 			list_del_init(&se_sess->sess_acl_list);
578 		/*
579 		 * If the session list is empty, then clear the pointer.
580 		 * Otherwise, set the struct se_session pointer from the tail
581 		 * element of the per struct se_node_acl active session list.
582 		 */
583 		if (list_empty(&se_nacl->acl_sess_list))
584 			se_nacl->nacl_sess = NULL;
585 		else {
586 			se_nacl->nacl_sess = container_of(
587 					se_nacl->acl_sess_list.prev,
588 					struct se_session, sess_acl_list);
589 		}
590 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
591 	}
592 }
593 EXPORT_SYMBOL(transport_deregister_session_configfs);
594 
595 void transport_free_session(struct se_session *se_sess)
596 {
597 	struct se_node_acl *se_nacl = se_sess->se_node_acl;
598 
599 	/*
600 	 * Drop the se_node_acl->nacl_kref obtained from within
601 	 * core_tpg_get_initiator_node_acl().
602 	 */
603 	if (se_nacl) {
604 		struct se_portal_group *se_tpg = se_nacl->se_tpg;
605 		const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo;
606 		unsigned long flags;
607 
608 		se_sess->se_node_acl = NULL;
609 
610 		/*
611 		 * Also determine if we need to drop the extra ->cmd_kref if
612 		 * it had been previously dynamically generated, and
613 		 * the endpoint is not caching dynamic ACLs.
614 		 */
615 		mutex_lock(&se_tpg->acl_node_mutex);
616 		if (se_nacl->dynamic_node_acl &&
617 		    !se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
618 			spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
619 			if (list_empty(&se_nacl->acl_sess_list))
620 				se_nacl->dynamic_stop = true;
621 			spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
622 
623 			if (se_nacl->dynamic_stop)
624 				list_del_init(&se_nacl->acl_list);
625 		}
626 		mutex_unlock(&se_tpg->acl_node_mutex);
627 
628 		if (se_nacl->dynamic_stop)
629 			target_put_nacl(se_nacl);
630 
631 		target_put_nacl(se_nacl);
632 	}
633 	if (se_sess->sess_cmd_map) {
634 		sbitmap_queue_free(&se_sess->sess_tag_pool);
635 		kvfree(se_sess->sess_cmd_map);
636 	}
637 	if (se_sess->cmd_cnt)
638 		target_free_cmd_counter(se_sess->cmd_cnt);
639 	kmem_cache_free(se_sess_cache, se_sess);
640 }
641 EXPORT_SYMBOL(transport_free_session);
642 
643 static int target_release_res(struct se_device *dev, void *data)
644 {
645 	struct se_session *sess = data;
646 
647 	if (dev->reservation_holder == sess)
648 		target_release_reservation(dev);
649 	return 0;
650 }
651 
652 void transport_deregister_session(struct se_session *se_sess)
653 {
654 	struct se_portal_group *se_tpg = se_sess->se_tpg;
655 	unsigned long flags;
656 
657 	if (!se_tpg) {
658 		transport_free_session(se_sess);
659 		return;
660 	}
661 
662 	spin_lock_irqsave(&se_tpg->session_lock, flags);
663 	list_del(&se_sess->sess_list);
664 	se_sess->se_tpg = NULL;
665 	se_sess->fabric_sess_ptr = NULL;
666 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
667 
668 	/*
669 	 * Since the session is being removed, release SPC-2
670 	 * reservations held by the session that is disappearing.
671 	 */
672 	target_for_each_device(target_release_res, se_sess);
673 
674 	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
675 		se_tpg->se_tpg_tfo->fabric_name);
676 	/*
677 	 * If last kref is dropping now for an explicit NodeACL, awake sleeping
678 	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
679 	 * removal context from within transport_free_session() code.
680 	 *
681 	 * For dynamic ACL, target_put_nacl() uses target_complete_nacl()
682 	 * to release all remaining generate_node_acl=1 created ACL resources.
683 	 */
684 
685 	transport_free_session(se_sess);
686 }
687 EXPORT_SYMBOL(transport_deregister_session);
688 
689 void target_remove_session(struct se_session *se_sess)
690 {
691 	transport_deregister_session_configfs(se_sess);
692 	transport_deregister_session(se_sess);
693 }
694 EXPORT_SYMBOL(target_remove_session);
695 
696 static void target_remove_from_state_list(struct se_cmd *cmd)
697 {
698 	struct se_device *dev = cmd->se_dev;
699 	unsigned long flags;
700 
701 	if (!dev)
702 		return;
703 
704 	spin_lock_irqsave(&dev->queues[cmd->cpuid].lock, flags);
705 	if (cmd->state_active) {
706 		list_del(&cmd->state_list);
707 		cmd->state_active = false;
708 	}
709 	spin_unlock_irqrestore(&dev->queues[cmd->cpuid].lock, flags);
710 }
711 
712 static void target_remove_from_tmr_list(struct se_cmd *cmd)
713 {
714 	struct se_device *dev = NULL;
715 	unsigned long flags;
716 
717 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
718 		dev = cmd->se_tmr_req->tmr_dev;
719 
720 	if (dev) {
721 		spin_lock_irqsave(&dev->se_tmr_lock, flags);
722 		if (cmd->se_tmr_req->tmr_dev)
723 			list_del_init(&cmd->se_tmr_req->tmr_list);
724 		spin_unlock_irqrestore(&dev->se_tmr_lock, flags);
725 	}
726 }
727 /*
728  * This function is called by the target core after the target core has
729  * finished processing a SCSI command or SCSI TMF. Both the regular command
730  * processing code and the code for aborting commands can call this
731  * function. CMD_T_STOP is set if and only if another thread is waiting
732  * inside transport_wait_for_tasks() for t_transport_stop_comp.
733  */
734 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
735 {
736 	unsigned long flags;
737 
738 	spin_lock_irqsave(&cmd->t_state_lock, flags);
739 	/*
740 	 * Determine if frontend context caller is requesting the stopping of
741 	 * this command for frontend exceptions.
742 	 */
743 	if (cmd->transport_state & CMD_T_STOP) {
744 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
745 			__func__, __LINE__, cmd->tag);
746 
747 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
748 
749 		complete_all(&cmd->t_transport_stop_comp);
750 		return 1;
751 	}
752 	cmd->transport_state &= ~CMD_T_ACTIVE;
753 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
754 
755 	/*
756 	 * Some fabric modules like tcm_loop can release their internally
757 	 * allocated I/O reference and struct se_cmd now.
758 	 *
759 	 * Fabric modules are expected to return '1' here if the se_cmd being
760 	 * passed is released at this point, or zero if not being released.
761 	 */
762 	return cmd->se_tfo->check_stop_free(cmd);
763 }
764 
765 static void transport_lun_remove_cmd(struct se_cmd *cmd)
766 {
767 	struct se_lun *lun = cmd->se_lun;
768 
769 	if (!lun)
770 		return;
771 
772 	target_remove_from_state_list(cmd);
773 	target_remove_from_tmr_list(cmd);
774 
775 	if (cmpxchg(&cmd->lun_ref_active, true, false))
776 		percpu_ref_put(&lun->lun_ref);
777 
778 	/*
779 	 * Clear struct se_cmd->se_lun before the handoff to FE.
780 	 */
781 	cmd->se_lun = NULL;
782 }
783 
784 static void target_complete_failure_work(struct work_struct *work)
785 {
786 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
787 
788 	transport_generic_request_failure(cmd, cmd->sense_reason);
789 }
790 
791 /*
792  * Used when asking transport to copy Sense Data from the underlying
793  * Linux/SCSI struct scsi_cmnd
794  */
795 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
796 {
797 	struct se_device *dev = cmd->se_dev;
798 
799 	WARN_ON(!cmd->se_lun);
800 
801 	if (!dev)
802 		return NULL;
803 
804 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
805 		return NULL;
806 
807 	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
808 
809 	pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
810 		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
811 	return cmd->sense_buffer;
812 }
813 
814 void transport_copy_sense_to_cmd(struct se_cmd *cmd, unsigned char *sense)
815 {
816 	unsigned char *cmd_sense_buf;
817 	unsigned long flags;
818 
819 	spin_lock_irqsave(&cmd->t_state_lock, flags);
820 	cmd_sense_buf = transport_get_sense_buffer(cmd);
821 	if (!cmd_sense_buf) {
822 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
823 		return;
824 	}
825 
826 	cmd->se_cmd_flags |= SCF_TRANSPORT_TASK_SENSE;
827 	memcpy(cmd_sense_buf, sense, cmd->scsi_sense_length);
828 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
829 }
830 EXPORT_SYMBOL(transport_copy_sense_to_cmd);
831 
832 static void target_handle_abort(struct se_cmd *cmd)
833 {
834 	bool tas = cmd->transport_state & CMD_T_TAS;
835 	bool ack_kref = cmd->se_cmd_flags & SCF_ACK_KREF;
836 	int ret;
837 
838 	pr_debug("tag %#llx: send_abort_response = %d\n", cmd->tag, tas);
839 
840 	if (tas) {
841 		if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
842 			cmd->scsi_status = SAM_STAT_TASK_ABORTED;
843 			pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
844 				 cmd->t_task_cdb[0], cmd->tag);
845 			trace_target_cmd_complete(cmd);
846 			ret = cmd->se_tfo->queue_status(cmd);
847 			if (ret) {
848 				transport_handle_queue_full(cmd, cmd->se_dev,
849 							    ret, false);
850 				return;
851 			}
852 		} else {
853 			cmd->se_tmr_req->response = TMR_FUNCTION_REJECTED;
854 			cmd->se_tfo->queue_tm_rsp(cmd);
855 		}
856 	} else {
857 		/*
858 		 * Allow the fabric driver to unmap any resources before
859 		 * releasing the descriptor via TFO->release_cmd().
860 		 */
861 		cmd->se_tfo->aborted_task(cmd);
862 		if (ack_kref)
863 			WARN_ON_ONCE(target_put_sess_cmd(cmd) != 0);
864 		/*
865 		 * To do: establish a unit attention condition on the I_T
866 		 * nexus associated with cmd. See also the paragraph "Aborting
867 		 * commands" in SAM.
868 		 */
869 	}
870 
871 	WARN_ON_ONCE(kref_read(&cmd->cmd_kref) == 0);
872 
873 	transport_lun_remove_cmd(cmd);
874 
875 	transport_cmd_check_stop_to_fabric(cmd);
876 }
877 
878 static void target_abort_work(struct work_struct *work)
879 {
880 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
881 
882 	target_handle_abort(cmd);
883 }
884 
885 static bool target_cmd_interrupted(struct se_cmd *cmd)
886 {
887 	int post_ret;
888 
889 	if (cmd->transport_state & CMD_T_ABORTED) {
890 		if (cmd->transport_complete_callback)
891 			cmd->transport_complete_callback(cmd, false, &post_ret);
892 		INIT_WORK(&cmd->work, target_abort_work);
893 		queue_work(target_completion_wq, &cmd->work);
894 		return true;
895 	} else if (cmd->transport_state & CMD_T_STOP) {
896 		if (cmd->transport_complete_callback)
897 			cmd->transport_complete_callback(cmd, false, &post_ret);
898 		complete_all(&cmd->t_transport_stop_comp);
899 		return true;
900 	}
901 
902 	return false;
903 }
904 
905 static void target_complete(struct se_cmd *cmd, int success)
906 {
907 	struct se_wwn *wwn = cmd->se_sess->se_tpg->se_tpg_wwn;
908 	struct se_dev_attrib *da;
909 	u8 compl_type;
910 	int cpu;
911 
912 	if (!wwn) {
913 		cpu = cmd->cpuid;
914 		goto queue_work;
915 	}
916 
917 	da = &cmd->se_dev->dev_attrib;
918 	if (da->complete_type == TARGET_FABRIC_DEFAULT_COMPL)
919 		compl_type = wwn->wwn_tf->tf_ops->default_compl_type;
920 	else if (da->complete_type == TARGET_DIRECT_COMPL &&
921 		 wwn->wwn_tf->tf_ops->direct_compl_supp)
922 		compl_type = TARGET_DIRECT_COMPL;
923 	else
924 		compl_type = TARGET_QUEUE_COMPL;
925 
926 	if (compl_type == TARGET_DIRECT_COMPL) {
927 		/*
928 		 * Failure handling and processing secondary stages of
929 		 * complex commands can be too heavy to handle from the
930 		 * fabric driver so always defer.
931 		 */
932 		if (success && !cmd->transport_complete_callback) {
933 			target_complete_ok_work(&cmd->work);
934 			return;
935 		}
936 
937 		compl_type = TARGET_QUEUE_COMPL;
938 	}
939 
940 queue_work:
941 	INIT_WORK(&cmd->work, success ? target_complete_ok_work :
942 		  target_complete_failure_work);
943 
944 	if (!wwn || wwn->cmd_compl_affinity == SE_COMPL_AFFINITY_CPUID)
945 		cpu = cmd->cpuid;
946 	else
947 		cpu = wwn->cmd_compl_affinity;
948 
949 	queue_work_on(cpu, target_completion_wq, &cmd->work);
950 }
951 
952 /* May be called from interrupt context so must not sleep. */
953 void target_complete_cmd_with_sense(struct se_cmd *cmd, u8 scsi_status,
954 				    sense_reason_t sense_reason)
955 {
956 	unsigned long flags;
957 	int success;
958 
959 	if (target_cmd_interrupted(cmd))
960 		return;
961 
962 	cmd->scsi_status = scsi_status;
963 	cmd->sense_reason = sense_reason;
964 
965 	spin_lock_irqsave(&cmd->t_state_lock, flags);
966 	switch (cmd->scsi_status) {
967 	case SAM_STAT_CHECK_CONDITION:
968 		if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
969 			success = 1;
970 		else
971 			success = 0;
972 		break;
973 	default:
974 		success = 1;
975 		break;
976 	}
977 
978 	cmd->t_state = TRANSPORT_COMPLETE;
979 	cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
980 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
981 
982 	target_complete(cmd, success);
983 }
984 EXPORT_SYMBOL(target_complete_cmd_with_sense);
985 
986 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
987 {
988 	target_complete_cmd_with_sense(cmd, scsi_status, scsi_status ?
989 			      TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE :
990 			      TCM_NO_SENSE);
991 }
992 EXPORT_SYMBOL(target_complete_cmd);
993 
994 void target_set_cmd_data_length(struct se_cmd *cmd, int length)
995 {
996 	if (length < cmd->data_length) {
997 		if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
998 			cmd->residual_count += cmd->data_length - length;
999 		} else {
1000 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1001 			cmd->residual_count = cmd->data_length - length;
1002 		}
1003 
1004 		cmd->data_length = length;
1005 	}
1006 }
1007 EXPORT_SYMBOL(target_set_cmd_data_length);
1008 
1009 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
1010 {
1011 	if (scsi_status == SAM_STAT_GOOD ||
1012 	    cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) {
1013 		target_set_cmd_data_length(cmd, length);
1014 	}
1015 
1016 	target_complete_cmd(cmd, scsi_status);
1017 }
1018 EXPORT_SYMBOL(target_complete_cmd_with_length);
1019 
1020 static void target_add_to_state_list(struct se_cmd *cmd)
1021 {
1022 	struct se_device *dev = cmd->se_dev;
1023 	unsigned long flags;
1024 
1025 	spin_lock_irqsave(&dev->queues[cmd->cpuid].lock, flags);
1026 	if (!cmd->state_active) {
1027 		list_add_tail(&cmd->state_list,
1028 			      &dev->queues[cmd->cpuid].state_list);
1029 		cmd->state_active = true;
1030 	}
1031 	spin_unlock_irqrestore(&dev->queues[cmd->cpuid].lock, flags);
1032 }
1033 
1034 /*
1035  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
1036  */
1037 static void transport_write_pending_qf(struct se_cmd *cmd);
1038 static void transport_complete_qf(struct se_cmd *cmd);
1039 
1040 void target_qf_do_work(struct work_struct *work)
1041 {
1042 	struct se_device *dev = container_of(work, struct se_device,
1043 					qf_work_queue);
1044 	LIST_HEAD(qf_cmd_list);
1045 	struct se_cmd *cmd, *cmd_tmp;
1046 
1047 	spin_lock_irq(&dev->qf_cmd_lock);
1048 	list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
1049 	spin_unlock_irq(&dev->qf_cmd_lock);
1050 
1051 	list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
1052 		list_del(&cmd->se_qf_node);
1053 		atomic_dec_mb(&dev->dev_qf_count);
1054 
1055 		pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
1056 			" context: %s\n", cmd->se_tfo->fabric_name, cmd,
1057 			(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
1058 			(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
1059 			: "UNKNOWN");
1060 
1061 		if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
1062 			transport_write_pending_qf(cmd);
1063 		else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK ||
1064 			 cmd->t_state == TRANSPORT_COMPLETE_QF_ERR)
1065 			transport_complete_qf(cmd);
1066 	}
1067 }
1068 
1069 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
1070 {
1071 	switch (cmd->data_direction) {
1072 	case DMA_NONE:
1073 		return "NONE";
1074 	case DMA_FROM_DEVICE:
1075 		return "READ";
1076 	case DMA_TO_DEVICE:
1077 		return "WRITE";
1078 	case DMA_BIDIRECTIONAL:
1079 		return "BIDI";
1080 	default:
1081 		break;
1082 	}
1083 
1084 	return "UNKNOWN";
1085 }
1086 
1087 void transport_dump_dev_state(
1088 	struct se_device *dev,
1089 	char *b,
1090 	int *bl)
1091 {
1092 	*bl += sprintf(b + *bl, "Status: ");
1093 	if (dev->export_count)
1094 		*bl += sprintf(b + *bl, "ACTIVATED");
1095 	else
1096 		*bl += sprintf(b + *bl, "DEACTIVATED");
1097 
1098 	*bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
1099 	*bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
1100 		dev->dev_attrib.block_size,
1101 		dev->dev_attrib.hw_max_sectors);
1102 	*bl += sprintf(b + *bl, "        ");
1103 }
1104 
1105 void transport_dump_vpd_proto_id(
1106 	struct t10_vpd *vpd,
1107 	unsigned char *p_buf,
1108 	int p_buf_len)
1109 {
1110 	unsigned char buf[VPD_TMP_BUF_SIZE];
1111 	int len;
1112 
1113 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1114 	len = sprintf(buf, "T10 VPD Protocol Identifier: ");
1115 
1116 	switch (vpd->protocol_identifier) {
1117 	case 0x00:
1118 		sprintf(buf+len, "Fibre Channel\n");
1119 		break;
1120 	case 0x10:
1121 		sprintf(buf+len, "Parallel SCSI\n");
1122 		break;
1123 	case 0x20:
1124 		sprintf(buf+len, "SSA\n");
1125 		break;
1126 	case 0x30:
1127 		sprintf(buf+len, "IEEE 1394\n");
1128 		break;
1129 	case 0x40:
1130 		sprintf(buf+len, "SCSI Remote Direct Memory Access"
1131 				" Protocol\n");
1132 		break;
1133 	case 0x50:
1134 		sprintf(buf+len, "Internet SCSI (iSCSI)\n");
1135 		break;
1136 	case 0x60:
1137 		sprintf(buf+len, "SAS Serial SCSI Protocol\n");
1138 		break;
1139 	case 0x70:
1140 		sprintf(buf+len, "Automation/Drive Interface Transport"
1141 				" Protocol\n");
1142 		break;
1143 	case 0x80:
1144 		sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
1145 		break;
1146 	default:
1147 		sprintf(buf+len, "Unknown 0x%02x\n",
1148 				vpd->protocol_identifier);
1149 		break;
1150 	}
1151 
1152 	if (p_buf)
1153 		strscpy(p_buf, buf, p_buf_len);
1154 	else
1155 		pr_debug("%s", buf);
1156 }
1157 
1158 void
1159 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
1160 {
1161 	/*
1162 	 * Check if the Protocol Identifier Valid (PIV) bit is set..
1163 	 *
1164 	 * from spc3r23.pdf section 7.5.1
1165 	 */
1166 	 if (page_83[1] & 0x80) {
1167 		vpd->protocol_identifier = (page_83[0] & 0xf0);
1168 		vpd->protocol_identifier_set = 1;
1169 		transport_dump_vpd_proto_id(vpd, NULL, 0);
1170 	}
1171 }
1172 EXPORT_SYMBOL(transport_set_vpd_proto_id);
1173 
1174 int transport_dump_vpd_assoc(
1175 	struct t10_vpd *vpd,
1176 	unsigned char *p_buf,
1177 	int p_buf_len)
1178 {
1179 	unsigned char buf[VPD_TMP_BUF_SIZE];
1180 	int ret = 0;
1181 	int len;
1182 
1183 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1184 	len = sprintf(buf, "T10 VPD Identifier Association: ");
1185 
1186 	switch (vpd->association) {
1187 	case 0x00:
1188 		sprintf(buf+len, "addressed logical unit\n");
1189 		break;
1190 	case 0x10:
1191 		sprintf(buf+len, "target port\n");
1192 		break;
1193 	case 0x20:
1194 		sprintf(buf+len, "SCSI target device\n");
1195 		break;
1196 	default:
1197 		sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
1198 		ret = -EINVAL;
1199 		break;
1200 	}
1201 
1202 	if (p_buf)
1203 		strscpy(p_buf, buf, p_buf_len);
1204 	else
1205 		pr_debug("%s", buf);
1206 
1207 	return ret;
1208 }
1209 
1210 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
1211 {
1212 	/*
1213 	 * The VPD identification association..
1214 	 *
1215 	 * from spc3r23.pdf Section 7.6.3.1 Table 297
1216 	 */
1217 	vpd->association = (page_83[1] & 0x30);
1218 	return transport_dump_vpd_assoc(vpd, NULL, 0);
1219 }
1220 EXPORT_SYMBOL(transport_set_vpd_assoc);
1221 
1222 int transport_dump_vpd_ident_type(
1223 	struct t10_vpd *vpd,
1224 	unsigned char *p_buf,
1225 	int p_buf_len)
1226 {
1227 	unsigned char buf[VPD_TMP_BUF_SIZE];
1228 	int ret = 0;
1229 	int len;
1230 
1231 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1232 	len = sprintf(buf, "T10 VPD Identifier Type: ");
1233 
1234 	switch (vpd->device_identifier_type) {
1235 	case 0x00:
1236 		sprintf(buf+len, "Vendor specific\n");
1237 		break;
1238 	case 0x01:
1239 		sprintf(buf+len, "T10 Vendor ID based\n");
1240 		break;
1241 	case 0x02:
1242 		sprintf(buf+len, "EUI-64 based\n");
1243 		break;
1244 	case 0x03:
1245 		sprintf(buf+len, "NAA\n");
1246 		break;
1247 	case 0x04:
1248 		sprintf(buf+len, "Relative target port identifier\n");
1249 		break;
1250 	case 0x08:
1251 		sprintf(buf+len, "SCSI name string\n");
1252 		break;
1253 	default:
1254 		sprintf(buf+len, "Unsupported: 0x%02x\n",
1255 				vpd->device_identifier_type);
1256 		ret = -EINVAL;
1257 		break;
1258 	}
1259 
1260 	if (p_buf) {
1261 		if (p_buf_len < strlen(buf)+1)
1262 			return -EINVAL;
1263 		strscpy(p_buf, buf, p_buf_len);
1264 	} else {
1265 		pr_debug("%s", buf);
1266 	}
1267 
1268 	return ret;
1269 }
1270 
1271 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1272 {
1273 	/*
1274 	 * The VPD identifier type..
1275 	 *
1276 	 * from spc3r23.pdf Section 7.6.3.1 Table 298
1277 	 */
1278 	vpd->device_identifier_type = (page_83[1] & 0x0f);
1279 	return transport_dump_vpd_ident_type(vpd, NULL, 0);
1280 }
1281 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1282 
1283 int transport_dump_vpd_ident(
1284 	struct t10_vpd *vpd,
1285 	unsigned char *p_buf,
1286 	int p_buf_len)
1287 {
1288 	unsigned char buf[VPD_TMP_BUF_SIZE];
1289 	int ret = 0;
1290 
1291 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1292 
1293 	switch (vpd->device_identifier_code_set) {
1294 	case 0x01: /* Binary */
1295 		snprintf(buf, sizeof(buf),
1296 			"T10 VPD Binary Device Identifier: %s\n",
1297 			&vpd->device_identifier[0]);
1298 		break;
1299 	case 0x02: /* ASCII */
1300 		snprintf(buf, sizeof(buf),
1301 			"T10 VPD ASCII Device Identifier: %s\n",
1302 			&vpd->device_identifier[0]);
1303 		break;
1304 	case 0x03: /* UTF-8 */
1305 		snprintf(buf, sizeof(buf),
1306 			"T10 VPD UTF-8 Device Identifier: %s\n",
1307 			&vpd->device_identifier[0]);
1308 		break;
1309 	default:
1310 		sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1311 			" 0x%02x", vpd->device_identifier_code_set);
1312 		ret = -EINVAL;
1313 		break;
1314 	}
1315 
1316 	if (p_buf)
1317 		strscpy(p_buf, buf, p_buf_len);
1318 	else
1319 		pr_debug("%s", buf);
1320 
1321 	return ret;
1322 }
1323 
1324 int
1325 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1326 {
1327 	static const char hex_str[] = "0123456789abcdef";
1328 	int j = 0, i = 4; /* offset to start of the identifier */
1329 
1330 	/*
1331 	 * The VPD Code Set (encoding)
1332 	 *
1333 	 * from spc3r23.pdf Section 7.6.3.1 Table 296
1334 	 */
1335 	vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1336 	switch (vpd->device_identifier_code_set) {
1337 	case 0x01: /* Binary */
1338 		vpd->device_identifier[j++] =
1339 				hex_str[vpd->device_identifier_type];
1340 		while (i < (4 + page_83[3])) {
1341 			vpd->device_identifier[j++] =
1342 				hex_str[(page_83[i] & 0xf0) >> 4];
1343 			vpd->device_identifier[j++] =
1344 				hex_str[page_83[i] & 0x0f];
1345 			i++;
1346 		}
1347 		break;
1348 	case 0x02: /* ASCII */
1349 	case 0x03: /* UTF-8 */
1350 		while (i < (4 + page_83[3]))
1351 			vpd->device_identifier[j++] = page_83[i++];
1352 		break;
1353 	default:
1354 		break;
1355 	}
1356 
1357 	return transport_dump_vpd_ident(vpd, NULL, 0);
1358 }
1359 EXPORT_SYMBOL(transport_set_vpd_ident);
1360 
1361 static sense_reason_t
1362 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1363 			       unsigned int size)
1364 {
1365 	u32 mtl;
1366 
1367 	if (!cmd->se_tfo->max_data_sg_nents)
1368 		return TCM_NO_SENSE;
1369 	/*
1370 	 * Check if fabric enforced maximum SGL entries per I/O descriptor
1371 	 * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1372 	 * residual_count and reduce original cmd->data_length to maximum
1373 	 * length based on single PAGE_SIZE entry scatter-lists.
1374 	 */
1375 	mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1376 	if (cmd->data_length > mtl) {
1377 		/*
1378 		 * If an existing CDB overflow is present, calculate new residual
1379 		 * based on CDB size minus fabric maximum transfer length.
1380 		 *
1381 		 * If an existing CDB underflow is present, calculate new residual
1382 		 * based on original cmd->data_length minus fabric maximum transfer
1383 		 * length.
1384 		 *
1385 		 * Otherwise, set the underflow residual based on cmd->data_length
1386 		 * minus fabric maximum transfer length.
1387 		 */
1388 		if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1389 			cmd->residual_count = (size - mtl);
1390 		} else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1391 			u32 orig_dl = size + cmd->residual_count;
1392 			cmd->residual_count = (orig_dl - mtl);
1393 		} else {
1394 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1395 			cmd->residual_count = (cmd->data_length - mtl);
1396 		}
1397 		cmd->data_length = mtl;
1398 		/*
1399 		 * Reset sbc_check_prot() calculated protection payload
1400 		 * length based upon the new smaller MTL.
1401 		 */
1402 		if (cmd->prot_length) {
1403 			u32 sectors = (mtl / dev->dev_attrib.block_size);
1404 			cmd->prot_length = dev->prot_length * sectors;
1405 		}
1406 	}
1407 	return TCM_NO_SENSE;
1408 }
1409 
1410 /**
1411  * target_cmd_size_check - Check whether there will be a residual.
1412  * @cmd: SCSI command.
1413  * @size: Data buffer size derived from CDB. The data buffer size provided by
1414  *   the SCSI transport driver is available in @cmd->data_length.
1415  *
1416  * Compare the data buffer size from the CDB with the data buffer limit from the transport
1417  * header. Set @cmd->residual_count and SCF_OVERFLOW_BIT or SCF_UNDERFLOW_BIT if necessary.
1418  *
1419  * Note: target drivers set @cmd->data_length by calling __target_init_cmd().
1420  *
1421  * Return: TCM_NO_SENSE
1422  */
1423 sense_reason_t
1424 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1425 {
1426 	struct se_device *dev = cmd->se_dev;
1427 
1428 	if (cmd->unknown_data_length) {
1429 		cmd->data_length = size;
1430 	} else if (size != cmd->data_length) {
1431 		pr_warn_ratelimited("TARGET_CORE[%s]: Expected Transfer Length:"
1432 			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
1433 			" 0x%02x\n", cmd->se_tfo->fabric_name,
1434 				cmd->data_length, size, cmd->t_task_cdb[0]);
1435 		/*
1436 		 * For READ command for the overflow case keep the existing
1437 		 * fabric provided ->data_length. Otherwise for the underflow
1438 		 * case, reset ->data_length to the smaller SCSI expected data
1439 		 * transfer length.
1440 		 */
1441 		if (size > cmd->data_length) {
1442 			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1443 			cmd->residual_count = (size - cmd->data_length);
1444 		} else {
1445 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1446 			cmd->residual_count = (cmd->data_length - size);
1447 			/*
1448 			 * Do not truncate ->data_length for WRITE command to
1449 			 * dump all payload
1450 			 */
1451 			if (cmd->data_direction == DMA_FROM_DEVICE) {
1452 				cmd->data_length = size;
1453 			}
1454 		}
1455 
1456 		if (cmd->data_direction == DMA_TO_DEVICE) {
1457 			if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1458 				pr_err_ratelimited("Rejecting underflow/overflow"
1459 						   " for WRITE data CDB\n");
1460 				return TCM_INVALID_FIELD_IN_COMMAND_IU;
1461 			}
1462 			/*
1463 			 * Some fabric drivers like iscsi-target still expect to
1464 			 * always reject overflow writes.  Reject this case until
1465 			 * full fabric driver level support for overflow writes
1466 			 * is introduced tree-wide.
1467 			 */
1468 			if (size > cmd->data_length) {
1469 				pr_err_ratelimited("Rejecting overflow for"
1470 						   " WRITE control CDB\n");
1471 				return TCM_INVALID_CDB_FIELD;
1472 			}
1473 		}
1474 	}
1475 
1476 	return target_check_max_data_sg_nents(cmd, dev, size);
1477 
1478 }
1479 
1480 /*
1481  * Used by fabric modules containing a local struct se_cmd within their
1482  * fabric dependent per I/O descriptor.
1483  *
1484  * Preserves the value of @cmd->tag.
1485  */
1486 void __target_init_cmd(struct se_cmd *cmd,
1487 		       const struct target_core_fabric_ops *tfo,
1488 		       struct se_session *se_sess, u32 data_length,
1489 		       int data_direction, int task_attr,
1490 		       unsigned char *sense_buffer, u64 unpacked_lun,
1491 		       struct target_cmd_counter *cmd_cnt)
1492 {
1493 	INIT_LIST_HEAD(&cmd->se_delayed_node);
1494 	INIT_LIST_HEAD(&cmd->se_qf_node);
1495 	INIT_LIST_HEAD(&cmd->state_list);
1496 	init_completion(&cmd->t_transport_stop_comp);
1497 	cmd->free_compl = NULL;
1498 	cmd->abrt_compl = NULL;
1499 	spin_lock_init(&cmd->t_state_lock);
1500 	INIT_WORK(&cmd->work, NULL);
1501 	kref_init(&cmd->cmd_kref);
1502 
1503 	cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1504 	cmd->se_tfo = tfo;
1505 	cmd->se_sess = se_sess;
1506 	cmd->data_length = data_length;
1507 	cmd->data_direction = data_direction;
1508 	cmd->sam_task_attr = task_attr;
1509 	cmd->sense_buffer = sense_buffer;
1510 	cmd->orig_fe_lun = unpacked_lun;
1511 	cmd->cmd_cnt = cmd_cnt;
1512 
1513 	if (!(cmd->se_cmd_flags & SCF_USE_CPUID))
1514 		cmd->cpuid = raw_smp_processor_id();
1515 
1516 	cmd->state_active = false;
1517 }
1518 EXPORT_SYMBOL(__target_init_cmd);
1519 
1520 static sense_reason_t
1521 transport_check_alloc_task_attr(struct se_cmd *cmd)
1522 {
1523 	struct se_device *dev = cmd->se_dev;
1524 
1525 	/*
1526 	 * Check if SAM Task Attribute emulation is enabled for this
1527 	 * struct se_device storage object
1528 	 */
1529 	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1530 		return 0;
1531 
1532 	if (cmd->sam_task_attr == TCM_ACA_TAG) {
1533 		pr_debug("SAM Task Attribute ACA"
1534 			" emulation is not supported\n");
1535 		return TCM_INVALID_CDB_FIELD;
1536 	}
1537 
1538 	return 0;
1539 }
1540 
1541 sense_reason_t
1542 target_cmd_init_cdb(struct se_cmd *cmd, unsigned char *cdb, gfp_t gfp)
1543 {
1544 	sense_reason_t ret;
1545 
1546 	/*
1547 	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1548 	 * for VARIABLE_LENGTH_CMD
1549 	 */
1550 	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1551 		pr_err("Received SCSI CDB with command_size: %d that"
1552 			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1553 			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1554 		ret = TCM_INVALID_CDB_FIELD;
1555 		goto err;
1556 	}
1557 	/*
1558 	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1559 	 * allocate the additional extended CDB buffer now..  Otherwise
1560 	 * setup the pointer from __t_task_cdb to t_task_cdb.
1561 	 */
1562 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1563 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb), gfp);
1564 		if (!cmd->t_task_cdb) {
1565 			cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1566 			pr_err("Unable to allocate cmd->t_task_cdb"
1567 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1568 				scsi_command_size(cdb),
1569 				(unsigned long)sizeof(cmd->__t_task_cdb));
1570 			ret = TCM_OUT_OF_RESOURCES;
1571 			goto err;
1572 		}
1573 	}
1574 	/*
1575 	 * Copy the original CDB into cmd->
1576 	 */
1577 	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1578 
1579 	trace_target_sequencer_start(cmd);
1580 	return 0;
1581 
1582 err:
1583 	/*
1584 	 * Copy the CDB here to allow trace_target_cmd_complete() to
1585 	 * print the cdb to the trace buffers.
1586 	 */
1587 	memcpy(cmd->t_task_cdb, cdb, min(scsi_command_size(cdb),
1588 					 (unsigned int)TCM_MAX_COMMAND_SIZE));
1589 	return ret;
1590 }
1591 EXPORT_SYMBOL(target_cmd_init_cdb);
1592 
1593 sense_reason_t
1594 target_cmd_parse_cdb(struct se_cmd *cmd)
1595 {
1596 	struct se_device *dev = cmd->se_dev;
1597 	sense_reason_t ret;
1598 
1599 	ret = dev->transport->parse_cdb(cmd);
1600 	if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1601 		pr_debug_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1602 				     cmd->se_tfo->fabric_name,
1603 				     cmd->se_sess->se_node_acl->initiatorname,
1604 				     cmd->t_task_cdb[0]);
1605 	if (ret)
1606 		return ret;
1607 
1608 	ret = transport_check_alloc_task_attr(cmd);
1609 	if (ret)
1610 		return ret;
1611 
1612 	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1613 	/*
1614 	 * If this is the xcopy_lun then we won't have lun_stats since we
1615 	 * can't export them.
1616 	 */
1617 	if (cmd->se_lun->lun_stats)
1618 		this_cpu_inc(cmd->se_lun->lun_stats->cmd_pdus);
1619 	return 0;
1620 }
1621 EXPORT_SYMBOL(target_cmd_parse_cdb);
1622 
1623 static int __target_submit(struct se_cmd *cmd)
1624 {
1625 	sense_reason_t ret;
1626 
1627 	might_sleep();
1628 
1629 	/*
1630 	 * Check if we need to delay processing because of ALUA
1631 	 * Active/NonOptimized primary access state..
1632 	 */
1633 	core_alua_check_nonop_delay(cmd);
1634 
1635 	if (cmd->t_data_nents != 0) {
1636 		/*
1637 		 * This is primarily a hack for udev and tcm loop which sends
1638 		 * INQUIRYs with a single page and expects the data to be
1639 		 * cleared.
1640 		 */
1641 		if (!(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1642 		    cmd->data_direction == DMA_FROM_DEVICE) {
1643 			struct scatterlist *sgl = cmd->t_data_sg;
1644 			unsigned char *buf = NULL;
1645 
1646 			BUG_ON(!sgl);
1647 
1648 			buf = kmap_local_page(sg_page(sgl));
1649 			if (buf) {
1650 				memset(buf + sgl->offset, 0, sgl->length);
1651 				kunmap_local(buf);
1652 			}
1653 		}
1654 	}
1655 
1656 	if (!cmd->se_lun) {
1657 		dump_stack();
1658 		pr_err("cmd->se_lun is NULL\n");
1659 		return -EINVAL;
1660 	}
1661 
1662 	/*
1663 	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1664 	 * outstanding descriptors are handled correctly during shutdown via
1665 	 * transport_wait_for_tasks()
1666 	 *
1667 	 * Also, we don't take cmd->t_state_lock here as we only expect
1668 	 * this to be called for initial descriptor submission.
1669 	 */
1670 	cmd->t_state = TRANSPORT_NEW_CMD;
1671 	cmd->transport_state |= CMD_T_ACTIVE;
1672 
1673 	/*
1674 	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1675 	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1676 	 * and call transport_generic_request_failure() if necessary..
1677 	 */
1678 	ret = transport_generic_new_cmd(cmd);
1679 	if (ret)
1680 		transport_generic_request_failure(cmd, ret);
1681 	return 0;
1682 }
1683 
1684 sense_reason_t
1685 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1686 		u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1687 {
1688 	if (!sgl || !sgl_count)
1689 		return 0;
1690 
1691 	/*
1692 	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1693 	 * scatterlists already have been set to follow what the fabric
1694 	 * passes for the original expected data transfer length.
1695 	 */
1696 	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1697 		pr_warn("Rejecting SCSI DATA overflow for fabric using"
1698 			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1699 		return TCM_INVALID_CDB_FIELD;
1700 	}
1701 
1702 	cmd->t_data_sg = sgl;
1703 	cmd->t_data_nents = sgl_count;
1704 	cmd->t_bidi_data_sg = sgl_bidi;
1705 	cmd->t_bidi_data_nents = sgl_bidi_count;
1706 
1707 	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1708 	return 0;
1709 }
1710 
1711 /**
1712  * target_init_cmd - initialize se_cmd
1713  * @se_cmd: command descriptor to init
1714  * @se_sess: associated se_sess for endpoint
1715  * @sense: pointer to SCSI sense buffer
1716  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1717  * @data_length: fabric expected data transfer length
1718  * @task_attr: SAM task attribute
1719  * @data_dir: DMA data direction
1720  * @flags: flags for command submission from target_sc_flags_tables
1721  *
1722  * Task tags are supported if the caller has set @se_cmd->tag.
1723  *
1724  * Returns:
1725  *	- less than zero to signal active I/O shutdown failure.
1726  *	- zero on success.
1727  *
1728  * If the fabric driver calls target_stop_session, then it must check the
1729  * return code and handle failures. This will never fail for other drivers,
1730  * and the return code can be ignored.
1731  */
1732 int target_init_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1733 		    unsigned char *sense, u64 unpacked_lun,
1734 		    u32 data_length, int task_attr, int data_dir, int flags)
1735 {
1736 	struct se_portal_group *se_tpg;
1737 
1738 	se_tpg = se_sess->se_tpg;
1739 	BUG_ON(!se_tpg);
1740 	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1741 
1742 	if (flags & TARGET_SCF_USE_CPUID)
1743 		se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1744 	/*
1745 	 * Signal bidirectional data payloads to target-core
1746 	 */
1747 	if (flags & TARGET_SCF_BIDI_OP)
1748 		se_cmd->se_cmd_flags |= SCF_BIDI;
1749 
1750 	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1751 		se_cmd->unknown_data_length = 1;
1752 	/*
1753 	 * Initialize se_cmd for target operation.  From this point
1754 	 * exceptions are handled by sending exception status via
1755 	 * target_core_fabric_ops->queue_status() callback
1756 	 */
1757 	__target_init_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess, data_length,
1758 			  data_dir, task_attr, sense, unpacked_lun,
1759 			  se_sess->cmd_cnt);
1760 
1761 	/*
1762 	 * Obtain struct se_cmd->cmd_kref reference. A second kref_get here is
1763 	 * necessary for fabrics using TARGET_SCF_ACK_KREF that expect a second
1764 	 * kref_put() to happen during fabric packet acknowledgement.
1765 	 */
1766 	return target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1767 }
1768 EXPORT_SYMBOL_GPL(target_init_cmd);
1769 
1770 /**
1771  * target_submit_prep - prepare cmd for submission
1772  * @se_cmd: command descriptor to prep
1773  * @cdb: pointer to SCSI CDB
1774  * @sgl: struct scatterlist memory for unidirectional mapping
1775  * @sgl_count: scatterlist count for unidirectional mapping
1776  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1777  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1778  * @sgl_prot: struct scatterlist memory protection information
1779  * @sgl_prot_count: scatterlist count for protection information
1780  * @gfp: gfp allocation type
1781  *
1782  * Returns:
1783  *	- less than zero to signal failure.
1784  *	- zero on success.
1785  *
1786  * If failure is returned, lio will the callers queue_status to complete
1787  * the cmd.
1788  */
1789 int target_submit_prep(struct se_cmd *se_cmd, unsigned char *cdb,
1790 		       struct scatterlist *sgl, u32 sgl_count,
1791 		       struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1792 		       struct scatterlist *sgl_prot, u32 sgl_prot_count,
1793 		       gfp_t gfp)
1794 {
1795 	sense_reason_t rc;
1796 
1797 	rc = target_cmd_init_cdb(se_cmd, cdb, gfp);
1798 	if (rc)
1799 		goto send_cc_direct;
1800 
1801 	/*
1802 	 * Locate se_lun pointer and attach it to struct se_cmd
1803 	 */
1804 	rc = transport_lookup_cmd_lun(se_cmd);
1805 	if (rc)
1806 		goto send_cc_direct;
1807 
1808 	rc = target_cmd_parse_cdb(se_cmd);
1809 	if (rc != 0)
1810 		goto generic_fail;
1811 
1812 	/*
1813 	 * Save pointers for SGLs containing protection information,
1814 	 * if present.
1815 	 */
1816 	if (sgl_prot_count) {
1817 		se_cmd->t_prot_sg = sgl_prot;
1818 		se_cmd->t_prot_nents = sgl_prot_count;
1819 		se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1820 	}
1821 
1822 	/*
1823 	 * When a non zero sgl_count has been passed perform SGL passthrough
1824 	 * mapping for pre-allocated fabric memory instead of having target
1825 	 * core perform an internal SGL allocation..
1826 	 */
1827 	if (sgl_count != 0) {
1828 		BUG_ON(!sgl);
1829 
1830 		rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1831 				sgl_bidi, sgl_bidi_count);
1832 		if (rc != 0)
1833 			goto generic_fail;
1834 	}
1835 
1836 	return 0;
1837 
1838 send_cc_direct:
1839 	transport_send_check_condition_and_sense(se_cmd, rc, 0);
1840 	target_put_sess_cmd(se_cmd);
1841 	return -EIO;
1842 
1843 generic_fail:
1844 	transport_generic_request_failure(se_cmd, rc);
1845 	return -EIO;
1846 }
1847 EXPORT_SYMBOL_GPL(target_submit_prep);
1848 
1849 /**
1850  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1851  *
1852  * @se_cmd: command descriptor to submit
1853  * @se_sess: associated se_sess for endpoint
1854  * @cdb: pointer to SCSI CDB
1855  * @sense: pointer to SCSI sense buffer
1856  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1857  * @data_length: fabric expected data transfer length
1858  * @task_attr: SAM task attribute
1859  * @data_dir: DMA data direction
1860  * @flags: flags for command submission from target_sc_flags_tables
1861  *
1862  * Task tags are supported if the caller has set @se_cmd->tag.
1863  *
1864  * This may only be called from process context, and also currently
1865  * assumes internal allocation of fabric payload buffer by target-core.
1866  *
1867  * It also assumes interal target core SGL memory allocation.
1868  *
1869  * This function must only be used by drivers that do their own
1870  * sync during shutdown and does not use target_stop_session. If there
1871  * is a failure this function will call into the fabric driver's
1872  * queue_status with a CHECK_CONDITION.
1873  */
1874 void target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1875 		unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1876 		u32 data_length, int task_attr, int data_dir, int flags)
1877 {
1878 	int rc;
1879 
1880 	rc = target_init_cmd(se_cmd, se_sess, sense, unpacked_lun, data_length,
1881 			     task_attr, data_dir, flags);
1882 	WARN(rc, "Invalid target_submit_cmd use. Driver must not use target_stop_session or call target_init_cmd directly.\n");
1883 	if (rc)
1884 		return;
1885 
1886 	if (target_submit_prep(se_cmd, cdb, NULL, 0, NULL, 0, NULL, 0,
1887 			       GFP_KERNEL))
1888 		return;
1889 
1890 	target_submit(se_cmd);
1891 }
1892 EXPORT_SYMBOL(target_submit_cmd);
1893 
1894 
1895 static struct se_dev_plug *target_plug_device(struct se_device *se_dev)
1896 {
1897 	struct se_dev_plug *se_plug;
1898 
1899 	if (!se_dev->transport->plug_device)
1900 		return NULL;
1901 
1902 	se_plug = se_dev->transport->plug_device(se_dev);
1903 	if (!se_plug)
1904 		return NULL;
1905 
1906 	se_plug->se_dev = se_dev;
1907 	/*
1908 	 * We have a ref to the lun at this point, but the cmds could
1909 	 * complete before we unplug, so grab a ref to the se_device so we
1910 	 * can call back into the backend.
1911 	 */
1912 	config_group_get(&se_dev->dev_group);
1913 	return se_plug;
1914 }
1915 
1916 static void target_unplug_device(struct se_dev_plug *se_plug)
1917 {
1918 	struct se_device *se_dev = se_plug->se_dev;
1919 
1920 	se_dev->transport->unplug_device(se_plug);
1921 	config_group_put(&se_dev->dev_group);
1922 }
1923 
1924 void target_queued_submit_work(struct work_struct *work)
1925 {
1926 	struct se_cmd_queue *sq = container_of(work, struct se_cmd_queue, work);
1927 	struct se_cmd *se_cmd, *next_cmd;
1928 	struct se_dev_plug *se_plug = NULL;
1929 	struct se_device *se_dev = NULL;
1930 	struct llist_node *cmd_list;
1931 
1932 	cmd_list = llist_del_all(&sq->cmd_list);
1933 	if (!cmd_list)
1934 		/* Previous call took what we were queued to submit */
1935 		return;
1936 
1937 	cmd_list = llist_reverse_order(cmd_list);
1938 	llist_for_each_entry_safe(se_cmd, next_cmd, cmd_list, se_cmd_list) {
1939 		if (!se_dev) {
1940 			se_dev = se_cmd->se_dev;
1941 			se_plug = target_plug_device(se_dev);
1942 		}
1943 
1944 		__target_submit(se_cmd);
1945 	}
1946 
1947 	if (se_plug)
1948 		target_unplug_device(se_plug);
1949 }
1950 
1951 /**
1952  * target_queue_submission - queue the cmd to run on the LIO workqueue
1953  * @se_cmd: command descriptor to submit
1954  */
1955 static void target_queue_submission(struct se_cmd *se_cmd)
1956 {
1957 	struct se_device *se_dev = se_cmd->se_dev;
1958 	int cpu = se_cmd->cpuid;
1959 	struct se_cmd_queue *sq;
1960 
1961 	sq = &se_dev->queues[cpu].sq;
1962 	llist_add(&se_cmd->se_cmd_list, &sq->cmd_list);
1963 	queue_work_on(cpu, target_submission_wq, &sq->work);
1964 }
1965 
1966 /**
1967  * target_submit - perform final initialization and submit cmd to LIO core
1968  * @se_cmd: command descriptor to submit
1969  *
1970  * target_submit_prep or something similar must have been called on the cmd,
1971  * and this must be called from process context.
1972  */
1973 int target_submit(struct se_cmd *se_cmd)
1974 {
1975 	const struct target_core_fabric_ops *tfo = se_cmd->se_sess->se_tpg->se_tpg_tfo;
1976 	struct se_dev_attrib *da = &se_cmd->se_dev->dev_attrib;
1977 	u8 submit_type;
1978 
1979 	if (da->submit_type == TARGET_FABRIC_DEFAULT_SUBMIT)
1980 		submit_type = tfo->default_submit_type;
1981 	else if (da->submit_type == TARGET_DIRECT_SUBMIT &&
1982 		 tfo->direct_submit_supp)
1983 		submit_type = TARGET_DIRECT_SUBMIT;
1984 	else
1985 		submit_type = TARGET_QUEUE_SUBMIT;
1986 
1987 	if (submit_type == TARGET_DIRECT_SUBMIT)
1988 		return __target_submit(se_cmd);
1989 
1990 	target_queue_submission(se_cmd);
1991 	return 0;
1992 }
1993 EXPORT_SYMBOL_GPL(target_submit);
1994 
1995 static void target_complete_tmr_failure(struct work_struct *work)
1996 {
1997 	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1998 
1999 	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
2000 	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
2001 
2002 	transport_lun_remove_cmd(se_cmd);
2003 	transport_cmd_check_stop_to_fabric(se_cmd);
2004 }
2005 
2006 /**
2007  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
2008  *                     for TMR CDBs
2009  *
2010  * @se_cmd: command descriptor to submit
2011  * @se_sess: associated se_sess for endpoint
2012  * @sense: pointer to SCSI sense buffer
2013  * @unpacked_lun: unpacked LUN to reference for struct se_lun
2014  * @fabric_tmr_ptr: fabric context for TMR req
2015  * @tm_type: Type of TM request
2016  * @gfp: gfp type for caller
2017  * @tag: referenced task tag for TMR_ABORT_TASK
2018  * @flags: submit cmd flags
2019  *
2020  * Callable from all contexts.
2021  **/
2022 
2023 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
2024 		unsigned char *sense, u64 unpacked_lun,
2025 		void *fabric_tmr_ptr, unsigned char tm_type,
2026 		gfp_t gfp, u64 tag, int flags)
2027 {
2028 	struct se_portal_group *se_tpg;
2029 	int ret;
2030 
2031 	se_tpg = se_sess->se_tpg;
2032 	BUG_ON(!se_tpg);
2033 
2034 	__target_init_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
2035 			  0, DMA_NONE, TCM_SIMPLE_TAG, sense, unpacked_lun,
2036 			  se_sess->cmd_cnt);
2037 	/*
2038 	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
2039 	 * allocation failure.
2040 	 */
2041 	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
2042 	if (ret < 0)
2043 		return -ENOMEM;
2044 
2045 	if (tm_type == TMR_ABORT_TASK)
2046 		se_cmd->se_tmr_req->ref_task_tag = tag;
2047 
2048 	/* See target_submit_cmd for commentary */
2049 	ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
2050 	if (ret) {
2051 		core_tmr_release_req(se_cmd->se_tmr_req);
2052 		return ret;
2053 	}
2054 
2055 	ret = transport_lookup_tmr_lun(se_cmd);
2056 	if (ret)
2057 		goto failure;
2058 
2059 	transport_generic_handle_tmr(se_cmd);
2060 	return 0;
2061 
2062 	/*
2063 	 * For callback during failure handling, push this work off
2064 	 * to process context with TMR_LUN_DOES_NOT_EXIST status.
2065 	 */
2066 failure:
2067 	INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
2068 	schedule_work(&se_cmd->work);
2069 	return 0;
2070 }
2071 EXPORT_SYMBOL(target_submit_tmr);
2072 
2073 /*
2074  * Handle SAM-esque emulation for generic transport request failures.
2075  */
2076 void transport_generic_request_failure(struct se_cmd *cmd,
2077 		sense_reason_t sense_reason)
2078 {
2079 	int ret = 0, post_ret;
2080 
2081 	pr_debug("-----[ Storage Engine Exception; sense_reason %d\n",
2082 		 sense_reason);
2083 	target_show_cmd("-----[ ", cmd);
2084 
2085 	/*
2086 	 * For SAM Task Attribute emulation for failed struct se_cmd
2087 	 */
2088 	transport_complete_task_attr(cmd);
2089 
2090 	if (cmd->transport_complete_callback)
2091 		cmd->transport_complete_callback(cmd, false, &post_ret);
2092 
2093 	if (cmd->transport_state & CMD_T_ABORTED) {
2094 		INIT_WORK(&cmd->work, target_abort_work);
2095 		queue_work(target_completion_wq, &cmd->work);
2096 		return;
2097 	}
2098 
2099 	switch (sense_reason) {
2100 	case TCM_NON_EXISTENT_LUN:
2101 	case TCM_UNSUPPORTED_SCSI_OPCODE:
2102 	case TCM_INVALID_CDB_FIELD:
2103 	case TCM_INVALID_PARAMETER_LIST:
2104 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
2105 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
2106 	case TCM_UNKNOWN_MODE_PAGE:
2107 	case TCM_WRITE_PROTECTED:
2108 	case TCM_ADDRESS_OUT_OF_RANGE:
2109 	case TCM_CHECK_CONDITION_ABORT_CMD:
2110 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2111 	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
2112 	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
2113 	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
2114 	case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
2115 	case TCM_TOO_MANY_TARGET_DESCS:
2116 	case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
2117 	case TCM_TOO_MANY_SEGMENT_DESCS:
2118 	case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
2119 	case TCM_INVALID_FIELD_IN_COMMAND_IU:
2120 	case TCM_ALUA_TG_PT_STANDBY:
2121 	case TCM_ALUA_TG_PT_UNAVAILABLE:
2122 	case TCM_ALUA_STATE_TRANSITION:
2123 	case TCM_ALUA_OFFLINE:
2124 		break;
2125 	case TCM_OUT_OF_RESOURCES:
2126 		cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
2127 		goto queue_status;
2128 	case TCM_LUN_BUSY:
2129 		cmd->scsi_status = SAM_STAT_BUSY;
2130 		goto queue_status;
2131 	case TCM_RESERVATION_CONFLICT:
2132 		/*
2133 		 * No SENSE Data payload for this case, set SCSI Status
2134 		 * and queue the response to $FABRIC_MOD.
2135 		 *
2136 		 * Uses linux/include/scsi/scsi.h SAM status codes defs
2137 		 */
2138 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
2139 		/*
2140 		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
2141 		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
2142 		 * CONFLICT STATUS.
2143 		 *
2144 		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
2145 		 */
2146 		if (cmd->se_sess &&
2147 		    cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl
2148 					== TARGET_UA_INTLCK_CTRL_ESTABLISH_UA) {
2149 			target_ua_allocate_lun(cmd->se_sess->se_node_acl,
2150 					       cmd->orig_fe_lun, 0x2C,
2151 					ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
2152 		}
2153 
2154 		goto queue_status;
2155 	default:
2156 		pr_err("Unknown transport error for CDB 0x%02x: %d\n",
2157 			cmd->t_task_cdb[0], sense_reason);
2158 		sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
2159 		break;
2160 	}
2161 
2162 	ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
2163 	if (ret)
2164 		goto queue_full;
2165 
2166 check_stop:
2167 	transport_lun_remove_cmd(cmd);
2168 	transport_cmd_check_stop_to_fabric(cmd);
2169 	return;
2170 
2171 queue_status:
2172 	trace_target_cmd_complete(cmd);
2173 	ret = cmd->se_tfo->queue_status(cmd);
2174 	if (!ret)
2175 		goto check_stop;
2176 queue_full:
2177 	transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2178 }
2179 EXPORT_SYMBOL(transport_generic_request_failure);
2180 
2181 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
2182 {
2183 	sense_reason_t ret;
2184 
2185 	if (!cmd->execute_cmd) {
2186 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2187 		goto err;
2188 	}
2189 	if (do_checks) {
2190 		/*
2191 		 * Check for an existing UNIT ATTENTION condition after
2192 		 * target_handle_task_attr() has done SAM task attr
2193 		 * checking, and possibly have already defered execution
2194 		 * out to target_restart_delayed_cmds() context.
2195 		 */
2196 		ret = target_scsi3_ua_check(cmd);
2197 		if (ret)
2198 			goto err;
2199 
2200 		ret = target_alua_state_check(cmd);
2201 		if (ret)
2202 			goto err;
2203 
2204 		ret = target_check_reservation(cmd);
2205 		if (ret) {
2206 			cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
2207 			goto err;
2208 		}
2209 	}
2210 
2211 	ret = cmd->execute_cmd(cmd);
2212 	if (!ret)
2213 		return;
2214 err:
2215 	spin_lock_irq(&cmd->t_state_lock);
2216 	cmd->transport_state &= ~CMD_T_SENT;
2217 	spin_unlock_irq(&cmd->t_state_lock);
2218 
2219 	transport_generic_request_failure(cmd, ret);
2220 }
2221 
2222 static int target_write_prot_action(struct se_cmd *cmd)
2223 {
2224 	u32 sectors;
2225 	/*
2226 	 * Perform WRITE_INSERT of PI using software emulation when backend
2227 	 * device has PI enabled, if the transport has not already generated
2228 	 * PI using hardware WRITE_INSERT offload.
2229 	 */
2230 	switch (cmd->prot_op) {
2231 	case TARGET_PROT_DOUT_INSERT:
2232 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
2233 			sbc_dif_generate(cmd);
2234 		break;
2235 	case TARGET_PROT_DOUT_STRIP:
2236 		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
2237 			break;
2238 
2239 		sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
2240 		cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2241 					     sectors, 0, cmd->t_prot_sg, 0);
2242 		if (unlikely(cmd->pi_err)) {
2243 			spin_lock_irq(&cmd->t_state_lock);
2244 			cmd->transport_state &= ~CMD_T_SENT;
2245 			spin_unlock_irq(&cmd->t_state_lock);
2246 			transport_generic_request_failure(cmd, cmd->pi_err);
2247 			return -1;
2248 		}
2249 		break;
2250 	default:
2251 		break;
2252 	}
2253 
2254 	return 0;
2255 }
2256 
2257 static bool target_handle_task_attr(struct se_cmd *cmd)
2258 {
2259 	struct se_device *dev = cmd->se_dev;
2260 	unsigned long flags;
2261 
2262 	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
2263 		return false;
2264 
2265 	cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
2266 
2267 	/*
2268 	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
2269 	 * to allow the passed struct se_cmd list of tasks to the front of the list.
2270 	 */
2271 	switch (cmd->sam_task_attr) {
2272 	case TCM_HEAD_TAG:
2273 		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
2274 			 cmd->t_task_cdb[0]);
2275 		return false;
2276 	case TCM_ORDERED_TAG:
2277 		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
2278 			 cmd->t_task_cdb[0]);
2279 		break;
2280 	default:
2281 		/*
2282 		 * For SIMPLE and UNTAGGED Task Attribute commands
2283 		 */
2284 retry:
2285 		if (percpu_ref_tryget_live(&dev->non_ordered))
2286 			return false;
2287 
2288 		break;
2289 	}
2290 
2291 	spin_lock_irqsave(&dev->delayed_cmd_lock, flags);
2292 	if (cmd->sam_task_attr == TCM_SIMPLE_TAG &&
2293 	    !percpu_ref_is_dying(&dev->non_ordered)) {
2294 		spin_unlock_irqrestore(&dev->delayed_cmd_lock, flags);
2295 		/* We raced with the last ordered completion so retry. */
2296 		goto retry;
2297 	} else if (!percpu_ref_is_dying(&dev->non_ordered)) {
2298 		percpu_ref_kill(&dev->non_ordered);
2299 	}
2300 
2301 	spin_lock(&cmd->t_state_lock);
2302 	cmd->transport_state &= ~CMD_T_SENT;
2303 	spin_unlock(&cmd->t_state_lock);
2304 
2305 	list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
2306 	spin_unlock_irqrestore(&dev->delayed_cmd_lock, flags);
2307 
2308 	pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
2309 		cmd->t_task_cdb[0], cmd->sam_task_attr);
2310 	/*
2311 	 * We may have no non ordered cmds when this function started or we
2312 	 * could have raced with the last simple/head cmd completing, so kick
2313 	 * the delayed handler here.
2314 	 */
2315 	schedule_work(&dev->delayed_cmd_work);
2316 	return true;
2317 }
2318 
2319 void target_execute_cmd(struct se_cmd *cmd)
2320 {
2321 	/*
2322 	 * Determine if frontend context caller is requesting the stopping of
2323 	 * this command for frontend exceptions.
2324 	 *
2325 	 * If the received CDB has already been aborted stop processing it here.
2326 	 */
2327 	if (target_cmd_interrupted(cmd))
2328 		return;
2329 
2330 	spin_lock_irq(&cmd->t_state_lock);
2331 	cmd->t_state = TRANSPORT_PROCESSING;
2332 	cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
2333 	spin_unlock_irq(&cmd->t_state_lock);
2334 
2335 	if (target_write_prot_action(cmd))
2336 		return;
2337 
2338 	if (target_handle_task_attr(cmd))
2339 		return;
2340 
2341 	__target_execute_cmd(cmd, true);
2342 }
2343 EXPORT_SYMBOL(target_execute_cmd);
2344 
2345 /*
2346  * Process all commands up to the last received ORDERED task attribute which
2347  * requires another blocking boundary
2348  */
2349 void target_do_delayed_work(struct work_struct *work)
2350 {
2351 	struct se_device *dev = container_of(work, struct se_device,
2352 					     delayed_cmd_work);
2353 
2354 	spin_lock(&dev->delayed_cmd_lock);
2355 	while (!dev->ordered_sync_in_progress) {
2356 		struct se_cmd *cmd;
2357 
2358 		/*
2359 		 * We can be woken up early/late due to races or the
2360 		 * extra wake up we do when adding commands to the list.
2361 		 * We check for both cases here.
2362 		 */
2363 		if (list_empty(&dev->delayed_cmd_list) ||
2364 		    !percpu_ref_is_zero(&dev->non_ordered))
2365 			break;
2366 
2367 		cmd = list_entry(dev->delayed_cmd_list.next,
2368 				 struct se_cmd, se_delayed_node);
2369 		cmd->se_cmd_flags |= SCF_TASK_ORDERED_SYNC;
2370 		cmd->transport_state |= CMD_T_SENT;
2371 
2372 		dev->ordered_sync_in_progress = true;
2373 
2374 		list_del(&cmd->se_delayed_node);
2375 		spin_unlock(&dev->delayed_cmd_lock);
2376 
2377 		__target_execute_cmd(cmd, true);
2378 		spin_lock(&dev->delayed_cmd_lock);
2379 	}
2380 	spin_unlock(&dev->delayed_cmd_lock);
2381 }
2382 
2383 static void transport_complete_ordered_sync(struct se_cmd *cmd)
2384 {
2385 	struct se_device *dev = cmd->se_dev;
2386 	unsigned long flags;
2387 
2388 	spin_lock_irqsave(&dev->delayed_cmd_lock, flags);
2389 	dev->dev_cur_ordered_id++;
2390 
2391 	pr_debug("Incremented dev_cur_ordered_id: %u for type %d\n",
2392 		 dev->dev_cur_ordered_id, cmd->sam_task_attr);
2393 
2394 	dev->ordered_sync_in_progress = false;
2395 
2396 	if (list_empty(&dev->delayed_cmd_list))
2397 		percpu_ref_resurrect(&dev->non_ordered);
2398 	else
2399 		schedule_work(&dev->delayed_cmd_work);
2400 
2401 	spin_unlock_irqrestore(&dev->delayed_cmd_lock, flags);
2402 }
2403 
2404 /*
2405  * Called from I/O completion to determine which dormant/delayed
2406  * and ordered cmds need to have their tasks added to the execution queue.
2407  */
2408 static void transport_complete_task_attr(struct se_cmd *cmd)
2409 {
2410 	struct se_device *dev = cmd->se_dev;
2411 
2412 	if (dev->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
2413 		return;
2414 
2415 	if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
2416 		return;
2417 
2418 	cmd->se_cmd_flags &= ~SCF_TASK_ATTR_SET;
2419 
2420 	if (cmd->se_cmd_flags & SCF_TASK_ORDERED_SYNC) {
2421 		transport_complete_ordered_sync(cmd);
2422 		return;
2423 	}
2424 
2425 	switch (cmd->sam_task_attr) {
2426 	case TCM_SIMPLE_TAG:
2427 		percpu_ref_put(&dev->non_ordered);
2428 		break;
2429 	case TCM_ORDERED_TAG:
2430 		/* All ordered should have been executed as sync */
2431 		WARN_ON(1);
2432 		break;
2433 	}
2434 }
2435 
2436 static void transport_complete_qf(struct se_cmd *cmd)
2437 {
2438 	int ret = 0;
2439 
2440 	transport_complete_task_attr(cmd);
2441 	/*
2442 	 * If a fabric driver ->write_pending() or ->queue_data_in() callback
2443 	 * has returned neither -ENOMEM or -EAGAIN, assume it's fatal and
2444 	 * the same callbacks should not be retried.  Return CHECK_CONDITION
2445 	 * if a scsi_status is not already set.
2446 	 *
2447 	 * If a fabric driver ->queue_status() has returned non zero, always
2448 	 * keep retrying no matter what..
2449 	 */
2450 	if (cmd->t_state == TRANSPORT_COMPLETE_QF_ERR) {
2451 		if (cmd->scsi_status)
2452 			goto queue_status;
2453 
2454 		translate_sense_reason(cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
2455 		goto queue_status;
2456 	}
2457 
2458 	/*
2459 	 * Check if we need to send a sense buffer from
2460 	 * the struct se_cmd in question. We do NOT want
2461 	 * to take this path of the IO has been marked as
2462 	 * needing to be treated like a "normal read". This
2463 	 * is the case if it's a tape read, and either the
2464 	 * FM, EOM, or ILI bits are set, but there is no
2465 	 * sense data.
2466 	 */
2467 	if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
2468 	    cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
2469 		goto queue_status;
2470 
2471 	switch (cmd->data_direction) {
2472 	case DMA_FROM_DEVICE:
2473 		/* queue status if not treating this as a normal read */
2474 		if (cmd->scsi_status &&
2475 		    !(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
2476 			goto queue_status;
2477 
2478 		trace_target_cmd_complete(cmd);
2479 		ret = cmd->se_tfo->queue_data_in(cmd);
2480 		break;
2481 	case DMA_TO_DEVICE:
2482 		if (cmd->se_cmd_flags & SCF_BIDI) {
2483 			ret = cmd->se_tfo->queue_data_in(cmd);
2484 			break;
2485 		}
2486 		fallthrough;
2487 	case DMA_NONE:
2488 queue_status:
2489 		trace_target_cmd_complete(cmd);
2490 		ret = cmd->se_tfo->queue_status(cmd);
2491 		break;
2492 	default:
2493 		break;
2494 	}
2495 
2496 	if (ret < 0) {
2497 		transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2498 		return;
2499 	}
2500 	transport_lun_remove_cmd(cmd);
2501 	transport_cmd_check_stop_to_fabric(cmd);
2502 }
2503 
2504 static void transport_handle_queue_full(struct se_cmd *cmd, struct se_device *dev,
2505 					int err, bool write_pending)
2506 {
2507 	/*
2508 	 * -EAGAIN or -ENOMEM signals retry of ->write_pending() and/or
2509 	 * ->queue_data_in() callbacks from new process context.
2510 	 *
2511 	 * Otherwise for other errors, transport_complete_qf() will send
2512 	 * CHECK_CONDITION via ->queue_status() instead of attempting to
2513 	 * retry associated fabric driver data-transfer callbacks.
2514 	 */
2515 	if (err == -EAGAIN || err == -ENOMEM) {
2516 		cmd->t_state = (write_pending) ? TRANSPORT_COMPLETE_QF_WP :
2517 						 TRANSPORT_COMPLETE_QF_OK;
2518 	} else {
2519 		pr_warn_ratelimited("Got unknown fabric queue status: %d\n", err);
2520 		cmd->t_state = TRANSPORT_COMPLETE_QF_ERR;
2521 	}
2522 
2523 	spin_lock_irq(&dev->qf_cmd_lock);
2524 	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2525 	atomic_inc_mb(&dev->dev_qf_count);
2526 	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2527 
2528 	schedule_work(&cmd->se_dev->qf_work_queue);
2529 }
2530 
2531 static bool target_read_prot_action(struct se_cmd *cmd)
2532 {
2533 	switch (cmd->prot_op) {
2534 	case TARGET_PROT_DIN_STRIP:
2535 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2536 			u32 sectors = cmd->data_length >>
2537 				  ilog2(cmd->se_dev->dev_attrib.block_size);
2538 
2539 			cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2540 						     sectors, 0, cmd->t_prot_sg,
2541 						     0);
2542 			if (cmd->pi_err)
2543 				return true;
2544 		}
2545 		break;
2546 	case TARGET_PROT_DIN_INSERT:
2547 		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2548 			break;
2549 
2550 		sbc_dif_generate(cmd);
2551 		break;
2552 	default:
2553 		break;
2554 	}
2555 
2556 	return false;
2557 }
2558 
2559 static void target_complete_ok_work(struct work_struct *work)
2560 {
2561 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2562 	int ret;
2563 
2564 	/*
2565 	 * Check if we need to move delayed/dormant tasks from cmds on the
2566 	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2567 	 * Attribute.
2568 	 */
2569 	transport_complete_task_attr(cmd);
2570 
2571 	/*
2572 	 * Check to schedule QUEUE_FULL work, or execute an existing
2573 	 * cmd->transport_qf_callback()
2574 	 */
2575 	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2576 		schedule_work(&cmd->se_dev->qf_work_queue);
2577 
2578 	/*
2579 	 * Check if we need to send a sense buffer from
2580 	 * the struct se_cmd in question. We do NOT want
2581 	 * to take this path of the IO has been marked as
2582 	 * needing to be treated like a "normal read". This
2583 	 * is the case if it's a tape read, and either the
2584 	 * FM, EOM, or ILI bits are set, but there is no
2585 	 * sense data.
2586 	 */
2587 	if (!(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL) &&
2588 	    cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2589 		WARN_ON(!cmd->scsi_status);
2590 		ret = transport_send_check_condition_and_sense(
2591 					cmd, 0, 1);
2592 		if (ret)
2593 			goto queue_full;
2594 
2595 		transport_lun_remove_cmd(cmd);
2596 		transport_cmd_check_stop_to_fabric(cmd);
2597 		return;
2598 	}
2599 	/*
2600 	 * Check for a callback, used by amongst other things
2601 	 * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2602 	 */
2603 	if (cmd->transport_complete_callback) {
2604 		sense_reason_t rc;
2605 		bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2606 		bool zero_dl = !(cmd->data_length);
2607 		int post_ret = 0;
2608 
2609 		rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2610 		if (!rc && !post_ret) {
2611 			if (caw && zero_dl)
2612 				goto queue_rsp;
2613 
2614 			return;
2615 		} else if (rc) {
2616 			ret = transport_send_check_condition_and_sense(cmd,
2617 						rc, 0);
2618 			if (ret)
2619 				goto queue_full;
2620 
2621 			transport_lun_remove_cmd(cmd);
2622 			transport_cmd_check_stop_to_fabric(cmd);
2623 			return;
2624 		}
2625 	}
2626 
2627 queue_rsp:
2628 	switch (cmd->data_direction) {
2629 	case DMA_FROM_DEVICE:
2630 		/*
2631 		 * if this is a READ-type IO, but SCSI status
2632 		 * is set, then skip returning data and just
2633 		 * return the status -- unless this IO is marked
2634 		 * as needing to be treated as a normal read,
2635 		 * in which case we want to go ahead and return
2636 		 * the data. This happens, for example, for tape
2637 		 * reads with the FM, EOM, or ILI bits set, with
2638 		 * no sense data.
2639 		 */
2640 		if (cmd->scsi_status &&
2641 		    !(cmd->se_cmd_flags & SCF_TREAT_READ_AS_NORMAL))
2642 			goto queue_status;
2643 
2644 		if (cmd->se_lun->lun_stats)
2645 			this_cpu_add(cmd->se_lun->lun_stats->tx_data_octets,
2646 				     cmd->data_length);
2647 		/*
2648 		 * Perform READ_STRIP of PI using software emulation when
2649 		 * backend had PI enabled, if the transport will not be
2650 		 * performing hardware READ_STRIP offload.
2651 		 */
2652 		if (target_read_prot_action(cmd)) {
2653 			ret = transport_send_check_condition_and_sense(cmd,
2654 						cmd->pi_err, 0);
2655 			if (ret)
2656 				goto queue_full;
2657 
2658 			transport_lun_remove_cmd(cmd);
2659 			transport_cmd_check_stop_to_fabric(cmd);
2660 			return;
2661 		}
2662 
2663 		trace_target_cmd_complete(cmd);
2664 		ret = cmd->se_tfo->queue_data_in(cmd);
2665 		if (ret)
2666 			goto queue_full;
2667 		break;
2668 	case DMA_TO_DEVICE:
2669 		if (cmd->se_lun->lun_stats)
2670 			this_cpu_add(cmd->se_lun->lun_stats->rx_data_octets,
2671 				     cmd->data_length);
2672 		/*
2673 		 * Check if we need to send READ payload for BIDI-COMMAND
2674 		 */
2675 		if (cmd->se_cmd_flags & SCF_BIDI) {
2676 			if (cmd->se_lun->lun_stats)
2677 				this_cpu_add(cmd->se_lun->lun_stats->tx_data_octets,
2678 					     cmd->data_length);
2679 			ret = cmd->se_tfo->queue_data_in(cmd);
2680 			if (ret)
2681 				goto queue_full;
2682 			break;
2683 		}
2684 		fallthrough;
2685 	case DMA_NONE:
2686 queue_status:
2687 		trace_target_cmd_complete(cmd);
2688 		ret = cmd->se_tfo->queue_status(cmd);
2689 		if (ret)
2690 			goto queue_full;
2691 		break;
2692 	default:
2693 		break;
2694 	}
2695 
2696 	transport_lun_remove_cmd(cmd);
2697 	transport_cmd_check_stop_to_fabric(cmd);
2698 	return;
2699 
2700 queue_full:
2701 	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2702 		" data_direction: %d\n", cmd, cmd->data_direction);
2703 
2704 	transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2705 }
2706 
2707 void target_free_sgl(struct scatterlist *sgl, int nents)
2708 {
2709 	sgl_free_n_order(sgl, nents, 0);
2710 }
2711 EXPORT_SYMBOL(target_free_sgl);
2712 
2713 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2714 {
2715 	/*
2716 	 * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2717 	 * emulation, and free + reset pointers if necessary..
2718 	 */
2719 	if (!cmd->t_data_sg_orig)
2720 		return;
2721 
2722 	kfree(cmd->t_data_sg);
2723 	cmd->t_data_sg = cmd->t_data_sg_orig;
2724 	cmd->t_data_sg_orig = NULL;
2725 	cmd->t_data_nents = cmd->t_data_nents_orig;
2726 	cmd->t_data_nents_orig = 0;
2727 }
2728 
2729 static inline void transport_free_pages(struct se_cmd *cmd)
2730 {
2731 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2732 		target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2733 		cmd->t_prot_sg = NULL;
2734 		cmd->t_prot_nents = 0;
2735 	}
2736 
2737 	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2738 		/*
2739 		 * Release special case READ buffer payload required for
2740 		 * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2741 		 */
2742 		if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2743 			target_free_sgl(cmd->t_bidi_data_sg,
2744 					   cmd->t_bidi_data_nents);
2745 			cmd->t_bidi_data_sg = NULL;
2746 			cmd->t_bidi_data_nents = 0;
2747 		}
2748 		transport_reset_sgl_orig(cmd);
2749 		return;
2750 	}
2751 	transport_reset_sgl_orig(cmd);
2752 
2753 	target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2754 	cmd->t_data_sg = NULL;
2755 	cmd->t_data_nents = 0;
2756 
2757 	target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2758 	cmd->t_bidi_data_sg = NULL;
2759 	cmd->t_bidi_data_nents = 0;
2760 }
2761 
2762 void *transport_kmap_data_sg(struct se_cmd *cmd)
2763 {
2764 	struct scatterlist *sg = cmd->t_data_sg;
2765 	struct page **pages;
2766 	int i;
2767 
2768 	/*
2769 	 * We need to take into account a possible offset here for fabrics like
2770 	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2771 	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2772 	 */
2773 	if (!cmd->t_data_nents)
2774 		return NULL;
2775 
2776 	BUG_ON(!sg);
2777 	if (cmd->t_data_nents == 1)
2778 		return kmap(sg_page(sg)) + sg->offset;
2779 
2780 	/* >1 page. use vmap */
2781 	pages = kmalloc_objs(*pages, cmd->t_data_nents);
2782 	if (!pages)
2783 		return NULL;
2784 
2785 	/* convert sg[] to pages[] */
2786 	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2787 		pages[i] = sg_page(sg);
2788 	}
2789 
2790 	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2791 	kfree(pages);
2792 	if (!cmd->t_data_vmap)
2793 		return NULL;
2794 
2795 	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2796 }
2797 EXPORT_SYMBOL(transport_kmap_data_sg);
2798 
2799 void transport_kunmap_data_sg(struct se_cmd *cmd)
2800 {
2801 	if (!cmd->t_data_nents) {
2802 		return;
2803 	} else if (cmd->t_data_nents == 1) {
2804 		kunmap(sg_page(cmd->t_data_sg));
2805 		return;
2806 	}
2807 
2808 	vunmap(cmd->t_data_vmap);
2809 	cmd->t_data_vmap = NULL;
2810 }
2811 EXPORT_SYMBOL(transport_kunmap_data_sg);
2812 
2813 int
2814 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2815 		 bool zero_page, bool chainable)
2816 {
2817 	gfp_t gfp = GFP_KERNEL | (zero_page ? __GFP_ZERO : 0);
2818 
2819 	*sgl = sgl_alloc_order(length, 0, chainable, gfp, nents);
2820 	return *sgl ? 0 : -ENOMEM;
2821 }
2822 EXPORT_SYMBOL(target_alloc_sgl);
2823 
2824 /*
2825  * Allocate any required resources to execute the command.  For writes we
2826  * might not have the payload yet, so notify the fabric via a call to
2827  * ->write_pending instead. Otherwise place it on the execution queue.
2828  */
2829 sense_reason_t
2830 transport_generic_new_cmd(struct se_cmd *cmd)
2831 {
2832 	unsigned long flags;
2833 	int ret = 0;
2834 	bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2835 
2836 	if (cmd->prot_op != TARGET_PROT_NORMAL &&
2837 	    !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2838 		ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2839 				       cmd->prot_length, true, false);
2840 		if (ret < 0)
2841 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2842 	}
2843 
2844 	/*
2845 	 * Determine if the TCM fabric module has already allocated physical
2846 	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2847 	 * beforehand.
2848 	 */
2849 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2850 	    cmd->data_length) {
2851 
2852 		if ((cmd->se_cmd_flags & SCF_BIDI) ||
2853 		    (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2854 			u32 bidi_length;
2855 
2856 			if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2857 				bidi_length = cmd->t_task_nolb *
2858 					      cmd->se_dev->dev_attrib.block_size;
2859 			else
2860 				bidi_length = cmd->data_length;
2861 
2862 			ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2863 					       &cmd->t_bidi_data_nents,
2864 					       bidi_length, zero_flag, false);
2865 			if (ret < 0)
2866 				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2867 		}
2868 
2869 		ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2870 				       cmd->data_length, zero_flag, false);
2871 		if (ret < 0)
2872 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2873 	} else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2874 		    cmd->data_length) {
2875 		/*
2876 		 * Special case for COMPARE_AND_WRITE with fabrics
2877 		 * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2878 		 */
2879 		u32 caw_length = cmd->t_task_nolb *
2880 				 cmd->se_dev->dev_attrib.block_size;
2881 
2882 		ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2883 				       &cmd->t_bidi_data_nents,
2884 				       caw_length, zero_flag, false);
2885 		if (ret < 0)
2886 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2887 	}
2888 	/*
2889 	 * If this command is not a write we can execute it right here,
2890 	 * for write buffers we need to notify the fabric driver first
2891 	 * and let it call back once the write buffers are ready.
2892 	 */
2893 	target_add_to_state_list(cmd);
2894 	if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2895 		target_execute_cmd(cmd);
2896 		return 0;
2897 	}
2898 
2899 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2900 	cmd->t_state = TRANSPORT_WRITE_PENDING;
2901 	/*
2902 	 * Determine if frontend context caller is requesting the stopping of
2903 	 * this command for frontend exceptions.
2904 	 */
2905 	if (cmd->transport_state & CMD_T_STOP &&
2906 	    !cmd->se_tfo->write_pending_must_be_called) {
2907 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
2908 			 __func__, __LINE__, cmd->tag);
2909 
2910 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2911 
2912 		complete_all(&cmd->t_transport_stop_comp);
2913 		return 0;
2914 	}
2915 	cmd->transport_state &= ~CMD_T_ACTIVE;
2916 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2917 
2918 	ret = cmd->se_tfo->write_pending(cmd);
2919 	if (ret)
2920 		goto queue_full;
2921 
2922 	return 0;
2923 
2924 queue_full:
2925 	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2926 	transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2927 	return 0;
2928 }
2929 EXPORT_SYMBOL(transport_generic_new_cmd);
2930 
2931 static void transport_write_pending_qf(struct se_cmd *cmd)
2932 {
2933 	unsigned long flags;
2934 	int ret;
2935 	bool stop;
2936 
2937 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2938 	stop = (cmd->transport_state & (CMD_T_STOP | CMD_T_ABORTED));
2939 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2940 
2941 	if (stop) {
2942 		pr_debug("%s:%d CMD_T_STOP|CMD_T_ABORTED for ITT: 0x%08llx\n",
2943 			__func__, __LINE__, cmd->tag);
2944 		complete_all(&cmd->t_transport_stop_comp);
2945 		return;
2946 	}
2947 
2948 	ret = cmd->se_tfo->write_pending(cmd);
2949 	if (ret) {
2950 		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2951 			 cmd);
2952 		transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2953 	}
2954 }
2955 
2956 static bool
2957 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2958 			   unsigned long *flags);
2959 
2960 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2961 {
2962 	unsigned long flags;
2963 
2964 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2965 	__transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2966 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2967 }
2968 
2969 /*
2970  * Call target_put_sess_cmd() and wait until target_release_cmd_kref(@cmd) has
2971  * finished.
2972  */
2973 void target_put_cmd_and_wait(struct se_cmd *cmd)
2974 {
2975 	DECLARE_COMPLETION_ONSTACK(compl);
2976 
2977 	WARN_ON_ONCE(cmd->abrt_compl);
2978 	cmd->abrt_compl = &compl;
2979 	target_put_sess_cmd(cmd);
2980 	wait_for_completion(&compl);
2981 }
2982 
2983 /*
2984  * This function is called by frontend drivers after processing of a command
2985  * has finished.
2986  *
2987  * The protocol for ensuring that either the regular frontend command
2988  * processing flow or target_handle_abort() code drops one reference is as
2989  * follows:
2990  * - Calling .queue_data_in(), .queue_status() or queue_tm_rsp() will cause
2991  *   the frontend driver to call this function synchronously or asynchronously.
2992  *   That will cause one reference to be dropped.
2993  * - During regular command processing the target core sets CMD_T_COMPLETE
2994  *   before invoking one of the .queue_*() functions.
2995  * - The code that aborts commands skips commands and TMFs for which
2996  *   CMD_T_COMPLETE has been set.
2997  * - CMD_T_ABORTED is set atomically after the CMD_T_COMPLETE check for
2998  *   commands that will be aborted.
2999  * - If the CMD_T_ABORTED flag is set but CMD_T_TAS has not been set
3000  *   transport_generic_free_cmd() skips its call to target_put_sess_cmd().
3001  * - For aborted commands for which CMD_T_TAS has been set .queue_status() will
3002  *   be called and will drop a reference.
3003  * - For aborted commands for which CMD_T_TAS has not been set .aborted_task()
3004  *   will be called. target_handle_abort() will drop the final reference.
3005  */
3006 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
3007 {
3008 	DECLARE_COMPLETION_ONSTACK(compl);
3009 	int ret = 0;
3010 	bool aborted = false, tas = false;
3011 
3012 	if (wait_for_tasks)
3013 		target_wait_free_cmd(cmd, &aborted, &tas);
3014 
3015 	if (cmd->se_cmd_flags & SCF_SE_LUN_CMD) {
3016 		/*
3017 		 * Handle WRITE failure case where transport_generic_new_cmd()
3018 		 * has already added se_cmd to state_list, but fabric has
3019 		 * failed command before I/O submission.
3020 		 */
3021 		if (cmd->state_active)
3022 			target_remove_from_state_list(cmd);
3023 
3024 		if (cmd->se_lun)
3025 			transport_lun_remove_cmd(cmd);
3026 	}
3027 	if (aborted)
3028 		cmd->free_compl = &compl;
3029 	ret = target_put_sess_cmd(cmd);
3030 	if (aborted) {
3031 		pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
3032 		wait_for_completion(&compl);
3033 		ret = 1;
3034 	}
3035 	return ret;
3036 }
3037 EXPORT_SYMBOL(transport_generic_free_cmd);
3038 
3039 /**
3040  * target_get_sess_cmd - Verify the session is accepting cmds and take ref
3041  * @se_cmd:	command descriptor to add
3042  * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
3043  */
3044 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
3045 {
3046 	int ret = 0;
3047 
3048 	/*
3049 	 * Add a second kref if the fabric caller is expecting to handle
3050 	 * fabric acknowledgement that requires two target_put_sess_cmd()
3051 	 * invocations before se_cmd descriptor release.
3052 	 */
3053 	if (ack_kref) {
3054 		kref_get(&se_cmd->cmd_kref);
3055 		se_cmd->se_cmd_flags |= SCF_ACK_KREF;
3056 	}
3057 
3058 	/*
3059 	 * Users like xcopy do not use counters since they never do a stop
3060 	 * and wait.
3061 	 */
3062 	if (se_cmd->cmd_cnt) {
3063 		if (!percpu_ref_tryget_live(&se_cmd->cmd_cnt->refcnt))
3064 			ret = -ESHUTDOWN;
3065 	}
3066 	if (ret && ack_kref)
3067 		target_put_sess_cmd(se_cmd);
3068 
3069 	return ret;
3070 }
3071 EXPORT_SYMBOL(target_get_sess_cmd);
3072 
3073 static void target_free_cmd_mem(struct se_cmd *cmd)
3074 {
3075 	transport_free_pages(cmd);
3076 
3077 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
3078 		core_tmr_release_req(cmd->se_tmr_req);
3079 	if (cmd->t_task_cdb != cmd->__t_task_cdb)
3080 		kfree(cmd->t_task_cdb);
3081 }
3082 
3083 static void target_release_cmd_kref(struct kref *kref)
3084 {
3085 	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
3086 	struct target_cmd_counter *cmd_cnt = se_cmd->cmd_cnt;
3087 	struct completion *free_compl = se_cmd->free_compl;
3088 	struct completion *abrt_compl = se_cmd->abrt_compl;
3089 
3090 	target_free_cmd_mem(se_cmd);
3091 	se_cmd->se_tfo->release_cmd(se_cmd);
3092 	if (free_compl)
3093 		complete(free_compl);
3094 	if (abrt_compl)
3095 		complete(abrt_compl);
3096 
3097 	if (cmd_cnt)
3098 		percpu_ref_put(&cmd_cnt->refcnt);
3099 }
3100 
3101 /**
3102  * target_put_sess_cmd - decrease the command reference count
3103  * @se_cmd:	command to drop a reference from
3104  *
3105  * Returns 1 if and only if this target_put_sess_cmd() call caused the
3106  * refcount to drop to zero. Returns zero otherwise.
3107  */
3108 int target_put_sess_cmd(struct se_cmd *se_cmd)
3109 {
3110 	return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
3111 }
3112 EXPORT_SYMBOL(target_put_sess_cmd);
3113 
3114 static const char *data_dir_name(enum dma_data_direction d)
3115 {
3116 	switch (d) {
3117 	case DMA_BIDIRECTIONAL:	return "BIDI";
3118 	case DMA_TO_DEVICE:	return "WRITE";
3119 	case DMA_FROM_DEVICE:	return "READ";
3120 	case DMA_NONE:		return "NONE";
3121 	}
3122 
3123 	return "(?)";
3124 }
3125 
3126 static const char *cmd_state_name(enum transport_state_table t)
3127 {
3128 	switch (t) {
3129 	case TRANSPORT_NO_STATE:	return "NO_STATE";
3130 	case TRANSPORT_NEW_CMD:		return "NEW_CMD";
3131 	case TRANSPORT_WRITE_PENDING:	return "WRITE_PENDING";
3132 	case TRANSPORT_PROCESSING:	return "PROCESSING";
3133 	case TRANSPORT_COMPLETE:	return "COMPLETE";
3134 	case TRANSPORT_ISTATE_PROCESSING:
3135 					return "ISTATE_PROCESSING";
3136 	case TRANSPORT_COMPLETE_QF_WP:	return "COMPLETE_QF_WP";
3137 	case TRANSPORT_COMPLETE_QF_OK:	return "COMPLETE_QF_OK";
3138 	case TRANSPORT_COMPLETE_QF_ERR:	return "COMPLETE_QF_ERR";
3139 	}
3140 
3141 	return "(?)";
3142 }
3143 
3144 static void target_append_str(char **str, const char *txt)
3145 {
3146 	char *prev = *str;
3147 
3148 	*str = *str ? kasprintf(GFP_ATOMIC, "%s,%s", *str, txt) :
3149 		kstrdup(txt, GFP_ATOMIC);
3150 	kfree(prev);
3151 }
3152 
3153 /*
3154  * Convert a transport state bitmask into a string. The caller is
3155  * responsible for freeing the returned pointer.
3156  */
3157 static char *target_ts_to_str(u32 ts)
3158 {
3159 	char *str = NULL;
3160 
3161 	if (ts & CMD_T_ABORTED)
3162 		target_append_str(&str, "aborted");
3163 	if (ts & CMD_T_ACTIVE)
3164 		target_append_str(&str, "active");
3165 	if (ts & CMD_T_COMPLETE)
3166 		target_append_str(&str, "complete");
3167 	if (ts & CMD_T_SENT)
3168 		target_append_str(&str, "sent");
3169 	if (ts & CMD_T_STOP)
3170 		target_append_str(&str, "stop");
3171 	if (ts & CMD_T_FABRIC_STOP)
3172 		target_append_str(&str, "fabric_stop");
3173 
3174 	return str;
3175 }
3176 
3177 static const char *target_tmf_name(enum tcm_tmreq_table tmf)
3178 {
3179 	switch (tmf) {
3180 	case TMR_ABORT_TASK:		return "ABORT_TASK";
3181 	case TMR_ABORT_TASK_SET:	return "ABORT_TASK_SET";
3182 	case TMR_CLEAR_ACA:		return "CLEAR_ACA";
3183 	case TMR_CLEAR_TASK_SET:	return "CLEAR_TASK_SET";
3184 	case TMR_LUN_RESET:		return "LUN_RESET";
3185 	case TMR_TARGET_WARM_RESET:	return "TARGET_WARM_RESET";
3186 	case TMR_TARGET_COLD_RESET:	return "TARGET_COLD_RESET";
3187 	case TMR_LUN_RESET_PRO:		return "LUN_RESET_PRO";
3188 	case TMR_UNKNOWN:		break;
3189 	}
3190 	return "(?)";
3191 }
3192 
3193 void target_show_cmd(const char *pfx, struct se_cmd *cmd)
3194 {
3195 	char *ts_str = target_ts_to_str(cmd->transport_state);
3196 	const u8 *cdb = cmd->t_task_cdb;
3197 	struct se_tmr_req *tmf = cmd->se_tmr_req;
3198 
3199 	if (!(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
3200 		pr_debug("%scmd %#02x:%#02x with tag %#llx dir %s i_state %d t_state %s len %d refcnt %d transport_state %s\n",
3201 			 pfx, cdb[0], cdb[1], cmd->tag,
3202 			 data_dir_name(cmd->data_direction),
3203 			 cmd->se_tfo->get_cmd_state(cmd),
3204 			 cmd_state_name(cmd->t_state), cmd->data_length,
3205 			 kref_read(&cmd->cmd_kref), ts_str);
3206 	} else {
3207 		pr_debug("%stmf %s with tag %#llx ref_task_tag %#llx i_state %d t_state %s refcnt %d transport_state %s\n",
3208 			 pfx, target_tmf_name(tmf->function), cmd->tag,
3209 			 tmf->ref_task_tag, cmd->se_tfo->get_cmd_state(cmd),
3210 			 cmd_state_name(cmd->t_state),
3211 			 kref_read(&cmd->cmd_kref), ts_str);
3212 	}
3213 	kfree(ts_str);
3214 }
3215 EXPORT_SYMBOL(target_show_cmd);
3216 
3217 static void target_stop_cmd_counter_confirm(struct percpu_ref *ref)
3218 {
3219 	struct target_cmd_counter *cmd_cnt = container_of(ref,
3220 						struct target_cmd_counter,
3221 						refcnt);
3222 	complete_all(&cmd_cnt->stop_done);
3223 }
3224 
3225 /**
3226  * target_stop_cmd_counter - Stop new IO from being added to the counter.
3227  * @cmd_cnt: counter to stop
3228  */
3229 void target_stop_cmd_counter(struct target_cmd_counter *cmd_cnt)
3230 {
3231 	pr_debug("Stopping command counter.\n");
3232 	if (!atomic_cmpxchg(&cmd_cnt->stopped, 0, 1))
3233 		percpu_ref_kill_and_confirm(&cmd_cnt->refcnt,
3234 					    target_stop_cmd_counter_confirm);
3235 }
3236 EXPORT_SYMBOL_GPL(target_stop_cmd_counter);
3237 
3238 /**
3239  * target_stop_session - Stop new IO from being queued on the session.
3240  * @se_sess: session to stop
3241  */
3242 void target_stop_session(struct se_session *se_sess)
3243 {
3244 	target_stop_cmd_counter(se_sess->cmd_cnt);
3245 }
3246 EXPORT_SYMBOL(target_stop_session);
3247 
3248 /**
3249  * target_wait_for_cmds - Wait for outstanding cmds.
3250  * @cmd_cnt: counter to wait for active I/O for.
3251  */
3252 void target_wait_for_cmds(struct target_cmd_counter *cmd_cnt)
3253 {
3254 	int ret;
3255 
3256 	WARN_ON_ONCE(!atomic_read(&cmd_cnt->stopped));
3257 
3258 	do {
3259 		pr_debug("Waiting for running cmds to complete.\n");
3260 		ret = wait_event_timeout(cmd_cnt->refcnt_wq,
3261 					 percpu_ref_is_zero(&cmd_cnt->refcnt),
3262 					 180 * HZ);
3263 	} while (ret <= 0);
3264 
3265 	wait_for_completion(&cmd_cnt->stop_done);
3266 	pr_debug("Waiting for cmds done.\n");
3267 }
3268 EXPORT_SYMBOL_GPL(target_wait_for_cmds);
3269 
3270 /**
3271  * target_wait_for_sess_cmds - Wait for outstanding commands
3272  * @se_sess: session to wait for active I/O
3273  */
3274 void target_wait_for_sess_cmds(struct se_session *se_sess)
3275 {
3276 	target_wait_for_cmds(se_sess->cmd_cnt);
3277 }
3278 EXPORT_SYMBOL(target_wait_for_sess_cmds);
3279 
3280 /*
3281  * Prevent that new percpu_ref_tryget_live() calls succeed and wait until
3282  * all references to the LUN have been released. Called during LUN shutdown.
3283  */
3284 void transport_clear_lun_ref(struct se_lun *lun)
3285 {
3286 	percpu_ref_kill(&lun->lun_ref);
3287 	wait_for_completion(&lun->lun_shutdown_comp);
3288 }
3289 
3290 static bool
3291 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
3292 			   bool *aborted, bool *tas, unsigned long *flags)
3293 	__releases(&cmd->t_state_lock)
3294 	__acquires(&cmd->t_state_lock)
3295 {
3296 	lockdep_assert_held(&cmd->t_state_lock);
3297 
3298 	if (fabric_stop)
3299 		cmd->transport_state |= CMD_T_FABRIC_STOP;
3300 
3301 	if (cmd->transport_state & CMD_T_ABORTED)
3302 		*aborted = true;
3303 
3304 	if (cmd->transport_state & CMD_T_TAS)
3305 		*tas = true;
3306 
3307 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
3308 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
3309 		return false;
3310 
3311 	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
3312 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
3313 		return false;
3314 
3315 	if (!(cmd->transport_state & CMD_T_ACTIVE))
3316 		return false;
3317 
3318 	if (fabric_stop && *aborted)
3319 		return false;
3320 
3321 	cmd->transport_state |= CMD_T_STOP;
3322 
3323 	target_show_cmd("wait_for_tasks: Stopping ", cmd);
3324 
3325 	spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
3326 
3327 	while (!wait_for_completion_timeout(&cmd->t_transport_stop_comp,
3328 					    180 * HZ))
3329 		target_show_cmd("wait for tasks: ", cmd);
3330 
3331 	spin_lock_irqsave(&cmd->t_state_lock, *flags);
3332 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
3333 
3334 	pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
3335 		 "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
3336 
3337 	return true;
3338 }
3339 
3340 /**
3341  * transport_wait_for_tasks - set CMD_T_STOP and wait for t_transport_stop_comp
3342  * @cmd: command to wait on
3343  */
3344 bool transport_wait_for_tasks(struct se_cmd *cmd)
3345 {
3346 	unsigned long flags;
3347 	bool ret, aborted = false, tas = false;
3348 
3349 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3350 	ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
3351 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3352 
3353 	return ret;
3354 }
3355 EXPORT_SYMBOL(transport_wait_for_tasks);
3356 
3357 struct sense_detail {
3358 	u8 key;
3359 	u8 asc;
3360 	u8 ascq;
3361 	bool add_sense_info;
3362 };
3363 
3364 static const struct sense_detail sense_detail_table[] = {
3365 	[TCM_NO_SENSE] = {
3366 		.key = NOT_READY
3367 	},
3368 	[TCM_NON_EXISTENT_LUN] = {
3369 		.key = ILLEGAL_REQUEST,
3370 		.asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
3371 	},
3372 	[TCM_UNSUPPORTED_SCSI_OPCODE] = {
3373 		.key = ILLEGAL_REQUEST,
3374 		.asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3375 	},
3376 	[TCM_SECTOR_COUNT_TOO_MANY] = {
3377 		.key = ILLEGAL_REQUEST,
3378 		.asc = 0x20, /* INVALID COMMAND OPERATION CODE */
3379 	},
3380 	[TCM_UNKNOWN_MODE_PAGE] = {
3381 		.key = ILLEGAL_REQUEST,
3382 		.asc = 0x24, /* INVALID FIELD IN CDB */
3383 	},
3384 	[TCM_CHECK_CONDITION_ABORT_CMD] = {
3385 		.key = ABORTED_COMMAND,
3386 		.asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
3387 		.ascq = 0x03,
3388 	},
3389 	[TCM_INCORRECT_AMOUNT_OF_DATA] = {
3390 		.key = ABORTED_COMMAND,
3391 		.asc = 0x0c, /* WRITE ERROR */
3392 		.ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
3393 	},
3394 	[TCM_INVALID_CDB_FIELD] = {
3395 		.key = ILLEGAL_REQUEST,
3396 		.asc = 0x24, /* INVALID FIELD IN CDB */
3397 	},
3398 	[TCM_INVALID_PARAMETER_LIST] = {
3399 		.key = ILLEGAL_REQUEST,
3400 		.asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
3401 	},
3402 	[TCM_TOO_MANY_TARGET_DESCS] = {
3403 		.key = ILLEGAL_REQUEST,
3404 		.asc = 0x26,
3405 		.ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
3406 	},
3407 	[TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
3408 		.key = ILLEGAL_REQUEST,
3409 		.asc = 0x26,
3410 		.ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
3411 	},
3412 	[TCM_TOO_MANY_SEGMENT_DESCS] = {
3413 		.key = ILLEGAL_REQUEST,
3414 		.asc = 0x26,
3415 		.ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
3416 	},
3417 	[TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
3418 		.key = ILLEGAL_REQUEST,
3419 		.asc = 0x26,
3420 		.ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
3421 	},
3422 	[TCM_PARAMETER_LIST_LENGTH_ERROR] = {
3423 		.key = ILLEGAL_REQUEST,
3424 		.asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
3425 	},
3426 	[TCM_UNEXPECTED_UNSOLICITED_DATA] = {
3427 		.key = ILLEGAL_REQUEST,
3428 		.asc = 0x0c, /* WRITE ERROR */
3429 		.ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
3430 	},
3431 	[TCM_SERVICE_CRC_ERROR] = {
3432 		.key = ABORTED_COMMAND,
3433 		.asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
3434 		.ascq = 0x05, /* N/A */
3435 	},
3436 	[TCM_SNACK_REJECTED] = {
3437 		.key = ABORTED_COMMAND,
3438 		.asc = 0x11, /* READ ERROR */
3439 		.ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
3440 	},
3441 	[TCM_WRITE_PROTECTED] = {
3442 		.key = DATA_PROTECT,
3443 		.asc = 0x27, /* WRITE PROTECTED */
3444 	},
3445 	[TCM_ADDRESS_OUT_OF_RANGE] = {
3446 		.key = ILLEGAL_REQUEST,
3447 		.asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
3448 	},
3449 	[TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
3450 		.key = UNIT_ATTENTION,
3451 	},
3452 	[TCM_MISCOMPARE_VERIFY] = {
3453 		.key = MISCOMPARE,
3454 		.asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
3455 		.ascq = 0x00,
3456 		.add_sense_info = true,
3457 	},
3458 	[TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
3459 		.key = ABORTED_COMMAND,
3460 		.asc = 0x10,
3461 		.ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
3462 		.add_sense_info = true,
3463 	},
3464 	[TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
3465 		.key = ABORTED_COMMAND,
3466 		.asc = 0x10,
3467 		.ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
3468 		.add_sense_info = true,
3469 	},
3470 	[TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
3471 		.key = ABORTED_COMMAND,
3472 		.asc = 0x10,
3473 		.ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
3474 		.add_sense_info = true,
3475 	},
3476 	[TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
3477 		.key = COPY_ABORTED,
3478 		.asc = 0x0d,
3479 		.ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
3480 
3481 	},
3482 	[TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
3483 		/*
3484 		 * Returning ILLEGAL REQUEST would cause immediate IO errors on
3485 		 * Solaris initiators.  Returning NOT READY instead means the
3486 		 * operations will be retried a finite number of times and we
3487 		 * can survive intermittent errors.
3488 		 */
3489 		.key = NOT_READY,
3490 		.asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
3491 	},
3492 	[TCM_INSUFFICIENT_REGISTRATION_RESOURCES] = {
3493 		/*
3494 		 * From spc4r22 section5.7.7,5.7.8
3495 		 * If a PERSISTENT RESERVE OUT command with a REGISTER service action
3496 		 * or a REGISTER AND IGNORE EXISTING KEY service action or
3497 		 * REGISTER AND MOVE service actionis attempted,
3498 		 * but there are insufficient device server resources to complete the
3499 		 * operation, then the command shall be terminated with CHECK CONDITION
3500 		 * status, with the sense key set to ILLEGAL REQUEST,and the additonal
3501 		 * sense code set to INSUFFICIENT REGISTRATION RESOURCES.
3502 		 */
3503 		.key = ILLEGAL_REQUEST,
3504 		.asc = 0x55,
3505 		.ascq = 0x04, /* INSUFFICIENT REGISTRATION RESOURCES */
3506 	},
3507 	[TCM_INVALID_FIELD_IN_COMMAND_IU] = {
3508 		.key = ILLEGAL_REQUEST,
3509 		.asc = 0x0e,
3510 		.ascq = 0x03, /* INVALID FIELD IN COMMAND INFORMATION UNIT */
3511 	},
3512 	[TCM_ALUA_TG_PT_STANDBY] = {
3513 		.key = NOT_READY,
3514 		.asc = 0x04,
3515 		.ascq = ASCQ_04H_ALUA_TG_PT_STANDBY,
3516 	},
3517 	[TCM_ALUA_TG_PT_UNAVAILABLE] = {
3518 		.key = NOT_READY,
3519 		.asc = 0x04,
3520 		.ascq = ASCQ_04H_ALUA_TG_PT_UNAVAILABLE,
3521 	},
3522 	[TCM_ALUA_STATE_TRANSITION] = {
3523 		.key = NOT_READY,
3524 		.asc = 0x04,
3525 		.ascq = ASCQ_04H_ALUA_STATE_TRANSITION,
3526 	},
3527 	[TCM_ALUA_OFFLINE] = {
3528 		.key = NOT_READY,
3529 		.asc = 0x04,
3530 		.ascq = ASCQ_04H_ALUA_OFFLINE,
3531 	},
3532 };
3533 
3534 /**
3535  * translate_sense_reason - translate a sense reason into T10 key, asc and ascq
3536  * @cmd: SCSI command in which the resulting sense buffer or SCSI status will
3537  *   be stored.
3538  * @reason: LIO sense reason code. If this argument has the value
3539  *   TCM_CHECK_CONDITION_UNIT_ATTENTION, try to dequeue a unit attention. If
3540  *   dequeuing a unit attention fails due to multiple commands being processed
3541  *   concurrently, set the command status to BUSY.
3542  *
3543  * Return: 0 upon success or -EINVAL if the sense buffer is too small.
3544  */
3545 static void translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
3546 {
3547 	const struct sense_detail *sd;
3548 	u8 *buffer = cmd->sense_buffer;
3549 	int r = (__force int)reason;
3550 	u8 key, asc, ascq;
3551 	bool desc_format = target_sense_desc_format(cmd->se_dev);
3552 
3553 	if (r < ARRAY_SIZE(sense_detail_table) && sense_detail_table[r].key)
3554 		sd = &sense_detail_table[r];
3555 	else
3556 		sd = &sense_detail_table[(__force int)
3557 				       TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
3558 
3559 	key = sd->key;
3560 	if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
3561 		if (!core_scsi3_ua_for_check_condition(cmd, &key, &asc,
3562 						       &ascq)) {
3563 			cmd->scsi_status = SAM_STAT_BUSY;
3564 			return;
3565 		}
3566 	} else {
3567 		WARN_ON_ONCE(sd->asc == 0);
3568 		asc = sd->asc;
3569 		ascq = sd->ascq;
3570 	}
3571 
3572 	cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
3573 	cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
3574 	cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
3575 	scsi_build_sense_buffer(desc_format, buffer, key, asc, ascq);
3576 	if (sd->add_sense_info)
3577 		WARN_ON_ONCE(scsi_set_sense_information(buffer,
3578 							cmd->scsi_sense_length,
3579 							cmd->sense_info) < 0);
3580 }
3581 
3582 int
3583 transport_send_check_condition_and_sense(struct se_cmd *cmd,
3584 		sense_reason_t reason, int from_transport)
3585 {
3586 	unsigned long flags;
3587 
3588 	WARN_ON_ONCE(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB);
3589 
3590 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3591 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
3592 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3593 		return 0;
3594 	}
3595 	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
3596 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3597 
3598 	if (!from_transport)
3599 		translate_sense_reason(cmd, reason);
3600 
3601 	trace_target_cmd_complete(cmd);
3602 	return cmd->se_tfo->queue_status(cmd);
3603 }
3604 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3605 
3606 /**
3607  * target_send_busy - Send SCSI BUSY status back to the initiator
3608  * @cmd: SCSI command for which to send a BUSY reply.
3609  *
3610  * Note: Only call this function if target_submit_cmd*() failed.
3611  */
3612 int target_send_busy(struct se_cmd *cmd)
3613 {
3614 	WARN_ON_ONCE(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB);
3615 
3616 	cmd->scsi_status = SAM_STAT_BUSY;
3617 	trace_target_cmd_complete(cmd);
3618 	return cmd->se_tfo->queue_status(cmd);
3619 }
3620 EXPORT_SYMBOL(target_send_busy);
3621 
3622 static void target_tmr_work(struct work_struct *work)
3623 {
3624 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3625 	struct se_device *dev = cmd->se_dev;
3626 	struct se_tmr_req *tmr = cmd->se_tmr_req;
3627 	int ret;
3628 
3629 	if (cmd->transport_state & CMD_T_ABORTED)
3630 		goto aborted;
3631 
3632 	switch (tmr->function) {
3633 	case TMR_ABORT_TASK:
3634 		core_tmr_abort_task(dev, tmr, cmd->se_sess);
3635 		break;
3636 	case TMR_ABORT_TASK_SET:
3637 	case TMR_CLEAR_ACA:
3638 	case TMR_CLEAR_TASK_SET:
3639 		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3640 		break;
3641 	case TMR_LUN_RESET:
3642 		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3643 		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3644 					 TMR_FUNCTION_REJECTED;
3645 		if (tmr->response == TMR_FUNCTION_COMPLETE) {
3646 			target_dev_ua_allocate(dev, 0x29,
3647 					       ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3648 		}
3649 		break;
3650 	case TMR_TARGET_WARM_RESET:
3651 		tmr->response = TMR_FUNCTION_REJECTED;
3652 		break;
3653 	case TMR_TARGET_COLD_RESET:
3654 		tmr->response = TMR_FUNCTION_REJECTED;
3655 		break;
3656 	default:
3657 		pr_err("Unknown TMR function: 0x%02x.\n",
3658 				tmr->function);
3659 		tmr->response = TMR_FUNCTION_REJECTED;
3660 		break;
3661 	}
3662 
3663 	if (cmd->transport_state & CMD_T_ABORTED)
3664 		goto aborted;
3665 
3666 	cmd->se_tfo->queue_tm_rsp(cmd);
3667 
3668 	transport_lun_remove_cmd(cmd);
3669 	transport_cmd_check_stop_to_fabric(cmd);
3670 	return;
3671 
3672 aborted:
3673 	target_handle_abort(cmd);
3674 }
3675 
3676 int transport_generic_handle_tmr(
3677 	struct se_cmd *cmd)
3678 {
3679 	unsigned long flags;
3680 	bool aborted = false;
3681 
3682 	spin_lock_irqsave(&cmd->se_dev->se_tmr_lock, flags);
3683 	list_add_tail(&cmd->se_tmr_req->tmr_list, &cmd->se_dev->dev_tmr_list);
3684 	spin_unlock_irqrestore(&cmd->se_dev->se_tmr_lock, flags);
3685 
3686 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3687 	if (cmd->transport_state & CMD_T_ABORTED) {
3688 		aborted = true;
3689 	} else {
3690 		cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3691 		cmd->transport_state |= CMD_T_ACTIVE;
3692 	}
3693 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3694 
3695 	if (aborted) {
3696 		pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d ref_tag: %llu tag: %llu\n",
3697 				    cmd->se_tmr_req->function,
3698 				    cmd->se_tmr_req->ref_task_tag, cmd->tag);
3699 		target_handle_abort(cmd);
3700 		return 0;
3701 	}
3702 
3703 	INIT_WORK(&cmd->work, target_tmr_work);
3704 	schedule_work(&cmd->work);
3705 	return 0;
3706 }
3707 EXPORT_SYMBOL(transport_generic_handle_tmr);
3708 
3709 bool
3710 target_check_wce(struct se_device *dev)
3711 {
3712 	bool wce = false;
3713 
3714 	if (dev->transport->get_write_cache)
3715 		wce = dev->transport->get_write_cache(dev);
3716 	else if (dev->dev_attrib.emulate_write_cache > 0)
3717 		wce = true;
3718 
3719 	return wce;
3720 }
3721 
3722 bool
3723 target_check_fua(struct se_device *dev)
3724 {
3725 	return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3726 }
3727