xref: /linux/drivers/target/target_core_transport.c (revision 0408c58be5a475c99b271f08d85859f7b59ec767)
1 /*******************************************************************************
2  * Filename:  target_core_transport.c
3  *
4  * This file contains the Generic Target Engine Core.
5  *
6  * (c) Copyright 2002-2013 Datera, Inc.
7  *
8  * Nicholas A. Bellinger <nab@kernel.org>
9  *
10  * This program is free software; you can redistribute it and/or modify
11  * it under the terms of the GNU General Public License as published by
12  * the Free Software Foundation; either version 2 of the License, or
13  * (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
23  *
24  ******************************************************************************/
25 
26 #include <linux/net.h>
27 #include <linux/delay.h>
28 #include <linux/string.h>
29 #include <linux/timer.h>
30 #include <linux/slab.h>
31 #include <linux/spinlock.h>
32 #include <linux/kthread.h>
33 #include <linux/in.h>
34 #include <linux/cdrom.h>
35 #include <linux/module.h>
36 #include <linux/ratelimit.h>
37 #include <linux/vmalloc.h>
38 #include <asm/unaligned.h>
39 #include <net/sock.h>
40 #include <net/tcp.h>
41 #include <scsi/scsi_proto.h>
42 #include <scsi/scsi_common.h>
43 
44 #include <target/target_core_base.h>
45 #include <target/target_core_backend.h>
46 #include <target/target_core_fabric.h>
47 
48 #include "target_core_internal.h"
49 #include "target_core_alua.h"
50 #include "target_core_pr.h"
51 #include "target_core_ua.h"
52 
53 #define CREATE_TRACE_POINTS
54 #include <trace/events/target.h>
55 
56 static struct workqueue_struct *target_completion_wq;
57 static struct kmem_cache *se_sess_cache;
58 struct kmem_cache *se_ua_cache;
59 struct kmem_cache *t10_pr_reg_cache;
60 struct kmem_cache *t10_alua_lu_gp_cache;
61 struct kmem_cache *t10_alua_lu_gp_mem_cache;
62 struct kmem_cache *t10_alua_tg_pt_gp_cache;
63 struct kmem_cache *t10_alua_lba_map_cache;
64 struct kmem_cache *t10_alua_lba_map_mem_cache;
65 
66 static void transport_complete_task_attr(struct se_cmd *cmd);
67 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason);
68 static void transport_handle_queue_full(struct se_cmd *cmd,
69 		struct se_device *dev, int err, bool write_pending);
70 static int transport_put_cmd(struct se_cmd *cmd);
71 static void target_complete_ok_work(struct work_struct *work);
72 
73 int init_se_kmem_caches(void)
74 {
75 	se_sess_cache = kmem_cache_create("se_sess_cache",
76 			sizeof(struct se_session), __alignof__(struct se_session),
77 			0, NULL);
78 	if (!se_sess_cache) {
79 		pr_err("kmem_cache_create() for struct se_session"
80 				" failed\n");
81 		goto out;
82 	}
83 	se_ua_cache = kmem_cache_create("se_ua_cache",
84 			sizeof(struct se_ua), __alignof__(struct se_ua),
85 			0, NULL);
86 	if (!se_ua_cache) {
87 		pr_err("kmem_cache_create() for struct se_ua failed\n");
88 		goto out_free_sess_cache;
89 	}
90 	t10_pr_reg_cache = kmem_cache_create("t10_pr_reg_cache",
91 			sizeof(struct t10_pr_registration),
92 			__alignof__(struct t10_pr_registration), 0, NULL);
93 	if (!t10_pr_reg_cache) {
94 		pr_err("kmem_cache_create() for struct t10_pr_registration"
95 				" failed\n");
96 		goto out_free_ua_cache;
97 	}
98 	t10_alua_lu_gp_cache = kmem_cache_create("t10_alua_lu_gp_cache",
99 			sizeof(struct t10_alua_lu_gp), __alignof__(struct t10_alua_lu_gp),
100 			0, NULL);
101 	if (!t10_alua_lu_gp_cache) {
102 		pr_err("kmem_cache_create() for t10_alua_lu_gp_cache"
103 				" failed\n");
104 		goto out_free_pr_reg_cache;
105 	}
106 	t10_alua_lu_gp_mem_cache = kmem_cache_create("t10_alua_lu_gp_mem_cache",
107 			sizeof(struct t10_alua_lu_gp_member),
108 			__alignof__(struct t10_alua_lu_gp_member), 0, NULL);
109 	if (!t10_alua_lu_gp_mem_cache) {
110 		pr_err("kmem_cache_create() for t10_alua_lu_gp_mem_"
111 				"cache failed\n");
112 		goto out_free_lu_gp_cache;
113 	}
114 	t10_alua_tg_pt_gp_cache = kmem_cache_create("t10_alua_tg_pt_gp_cache",
115 			sizeof(struct t10_alua_tg_pt_gp),
116 			__alignof__(struct t10_alua_tg_pt_gp), 0, NULL);
117 	if (!t10_alua_tg_pt_gp_cache) {
118 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
119 				"cache failed\n");
120 		goto out_free_lu_gp_mem_cache;
121 	}
122 	t10_alua_lba_map_cache = kmem_cache_create(
123 			"t10_alua_lba_map_cache",
124 			sizeof(struct t10_alua_lba_map),
125 			__alignof__(struct t10_alua_lba_map), 0, NULL);
126 	if (!t10_alua_lba_map_cache) {
127 		pr_err("kmem_cache_create() for t10_alua_lba_map_"
128 				"cache failed\n");
129 		goto out_free_tg_pt_gp_cache;
130 	}
131 	t10_alua_lba_map_mem_cache = kmem_cache_create(
132 			"t10_alua_lba_map_mem_cache",
133 			sizeof(struct t10_alua_lba_map_member),
134 			__alignof__(struct t10_alua_lba_map_member), 0, NULL);
135 	if (!t10_alua_lba_map_mem_cache) {
136 		pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
137 				"cache failed\n");
138 		goto out_free_lba_map_cache;
139 	}
140 
141 	target_completion_wq = alloc_workqueue("target_completion",
142 					       WQ_MEM_RECLAIM, 0);
143 	if (!target_completion_wq)
144 		goto out_free_lba_map_mem_cache;
145 
146 	return 0;
147 
148 out_free_lba_map_mem_cache:
149 	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
150 out_free_lba_map_cache:
151 	kmem_cache_destroy(t10_alua_lba_map_cache);
152 out_free_tg_pt_gp_cache:
153 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
154 out_free_lu_gp_mem_cache:
155 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
156 out_free_lu_gp_cache:
157 	kmem_cache_destroy(t10_alua_lu_gp_cache);
158 out_free_pr_reg_cache:
159 	kmem_cache_destroy(t10_pr_reg_cache);
160 out_free_ua_cache:
161 	kmem_cache_destroy(se_ua_cache);
162 out_free_sess_cache:
163 	kmem_cache_destroy(se_sess_cache);
164 out:
165 	return -ENOMEM;
166 }
167 
168 void release_se_kmem_caches(void)
169 {
170 	destroy_workqueue(target_completion_wq);
171 	kmem_cache_destroy(se_sess_cache);
172 	kmem_cache_destroy(se_ua_cache);
173 	kmem_cache_destroy(t10_pr_reg_cache);
174 	kmem_cache_destroy(t10_alua_lu_gp_cache);
175 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
176 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
177 	kmem_cache_destroy(t10_alua_lba_map_cache);
178 	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
179 }
180 
181 /* This code ensures unique mib indexes are handed out. */
182 static DEFINE_SPINLOCK(scsi_mib_index_lock);
183 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
184 
185 /*
186  * Allocate a new row index for the entry type specified
187  */
188 u32 scsi_get_new_index(scsi_index_t type)
189 {
190 	u32 new_index;
191 
192 	BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
193 
194 	spin_lock(&scsi_mib_index_lock);
195 	new_index = ++scsi_mib_index[type];
196 	spin_unlock(&scsi_mib_index_lock);
197 
198 	return new_index;
199 }
200 
201 void transport_subsystem_check_init(void)
202 {
203 	int ret;
204 	static int sub_api_initialized;
205 
206 	if (sub_api_initialized)
207 		return;
208 
209 	ret = request_module("target_core_iblock");
210 	if (ret != 0)
211 		pr_err("Unable to load target_core_iblock\n");
212 
213 	ret = request_module("target_core_file");
214 	if (ret != 0)
215 		pr_err("Unable to load target_core_file\n");
216 
217 	ret = request_module("target_core_pscsi");
218 	if (ret != 0)
219 		pr_err("Unable to load target_core_pscsi\n");
220 
221 	ret = request_module("target_core_user");
222 	if (ret != 0)
223 		pr_err("Unable to load target_core_user\n");
224 
225 	sub_api_initialized = 1;
226 }
227 
228 struct se_session *transport_init_session(enum target_prot_op sup_prot_ops)
229 {
230 	struct se_session *se_sess;
231 
232 	se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
233 	if (!se_sess) {
234 		pr_err("Unable to allocate struct se_session from"
235 				" se_sess_cache\n");
236 		return ERR_PTR(-ENOMEM);
237 	}
238 	INIT_LIST_HEAD(&se_sess->sess_list);
239 	INIT_LIST_HEAD(&se_sess->sess_acl_list);
240 	INIT_LIST_HEAD(&se_sess->sess_cmd_list);
241 	INIT_LIST_HEAD(&se_sess->sess_wait_list);
242 	spin_lock_init(&se_sess->sess_cmd_lock);
243 	se_sess->sup_prot_ops = sup_prot_ops;
244 
245 	return se_sess;
246 }
247 EXPORT_SYMBOL(transport_init_session);
248 
249 int transport_alloc_session_tags(struct se_session *se_sess,
250 			         unsigned int tag_num, unsigned int tag_size)
251 {
252 	int rc;
253 
254 	se_sess->sess_cmd_map = kzalloc(tag_num * tag_size,
255 					GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
256 	if (!se_sess->sess_cmd_map) {
257 		se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
258 		if (!se_sess->sess_cmd_map) {
259 			pr_err("Unable to allocate se_sess->sess_cmd_map\n");
260 			return -ENOMEM;
261 		}
262 	}
263 
264 	rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
265 	if (rc < 0) {
266 		pr_err("Unable to init se_sess->sess_tag_pool,"
267 			" tag_num: %u\n", tag_num);
268 		kvfree(se_sess->sess_cmd_map);
269 		se_sess->sess_cmd_map = NULL;
270 		return -ENOMEM;
271 	}
272 
273 	return 0;
274 }
275 EXPORT_SYMBOL(transport_alloc_session_tags);
276 
277 struct se_session *transport_init_session_tags(unsigned int tag_num,
278 					       unsigned int tag_size,
279 					       enum target_prot_op sup_prot_ops)
280 {
281 	struct se_session *se_sess;
282 	int rc;
283 
284 	if (tag_num != 0 && !tag_size) {
285 		pr_err("init_session_tags called with percpu-ida tag_num:"
286 		       " %u, but zero tag_size\n", tag_num);
287 		return ERR_PTR(-EINVAL);
288 	}
289 	if (!tag_num && tag_size) {
290 		pr_err("init_session_tags called with percpu-ida tag_size:"
291 		       " %u, but zero tag_num\n", tag_size);
292 		return ERR_PTR(-EINVAL);
293 	}
294 
295 	se_sess = transport_init_session(sup_prot_ops);
296 	if (IS_ERR(se_sess))
297 		return se_sess;
298 
299 	rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
300 	if (rc < 0) {
301 		transport_free_session(se_sess);
302 		return ERR_PTR(-ENOMEM);
303 	}
304 
305 	return se_sess;
306 }
307 EXPORT_SYMBOL(transport_init_session_tags);
308 
309 /*
310  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
311  */
312 void __transport_register_session(
313 	struct se_portal_group *se_tpg,
314 	struct se_node_acl *se_nacl,
315 	struct se_session *se_sess,
316 	void *fabric_sess_ptr)
317 {
318 	const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
319 	unsigned char buf[PR_REG_ISID_LEN];
320 
321 	se_sess->se_tpg = se_tpg;
322 	se_sess->fabric_sess_ptr = fabric_sess_ptr;
323 	/*
324 	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
325 	 *
326 	 * Only set for struct se_session's that will actually be moving I/O.
327 	 * eg: *NOT* discovery sessions.
328 	 */
329 	if (se_nacl) {
330 		/*
331 		 *
332 		 * Determine if fabric allows for T10-PI feature bits exposed to
333 		 * initiators for device backends with !dev->dev_attrib.pi_prot_type.
334 		 *
335 		 * If so, then always save prot_type on a per se_node_acl node
336 		 * basis and re-instate the previous sess_prot_type to avoid
337 		 * disabling PI from below any previously initiator side
338 		 * registered LUNs.
339 		 */
340 		if (se_nacl->saved_prot_type)
341 			se_sess->sess_prot_type = se_nacl->saved_prot_type;
342 		else if (tfo->tpg_check_prot_fabric_only)
343 			se_sess->sess_prot_type = se_nacl->saved_prot_type =
344 					tfo->tpg_check_prot_fabric_only(se_tpg);
345 		/*
346 		 * If the fabric module supports an ISID based TransportID,
347 		 * save this value in binary from the fabric I_T Nexus now.
348 		 */
349 		if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
350 			memset(&buf[0], 0, PR_REG_ISID_LEN);
351 			se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
352 					&buf[0], PR_REG_ISID_LEN);
353 			se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
354 		}
355 
356 		spin_lock_irq(&se_nacl->nacl_sess_lock);
357 		/*
358 		 * The se_nacl->nacl_sess pointer will be set to the
359 		 * last active I_T Nexus for each struct se_node_acl.
360 		 */
361 		se_nacl->nacl_sess = se_sess;
362 
363 		list_add_tail(&se_sess->sess_acl_list,
364 			      &se_nacl->acl_sess_list);
365 		spin_unlock_irq(&se_nacl->nacl_sess_lock);
366 	}
367 	list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
368 
369 	pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
370 		se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
371 }
372 EXPORT_SYMBOL(__transport_register_session);
373 
374 void transport_register_session(
375 	struct se_portal_group *se_tpg,
376 	struct se_node_acl *se_nacl,
377 	struct se_session *se_sess,
378 	void *fabric_sess_ptr)
379 {
380 	unsigned long flags;
381 
382 	spin_lock_irqsave(&se_tpg->session_lock, flags);
383 	__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
384 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
385 }
386 EXPORT_SYMBOL(transport_register_session);
387 
388 struct se_session *
389 target_alloc_session(struct se_portal_group *tpg,
390 		     unsigned int tag_num, unsigned int tag_size,
391 		     enum target_prot_op prot_op,
392 		     const char *initiatorname, void *private,
393 		     int (*callback)(struct se_portal_group *,
394 				     struct se_session *, void *))
395 {
396 	struct se_session *sess;
397 
398 	/*
399 	 * If the fabric driver is using percpu-ida based pre allocation
400 	 * of I/O descriptor tags, go ahead and perform that setup now..
401 	 */
402 	if (tag_num != 0)
403 		sess = transport_init_session_tags(tag_num, tag_size, prot_op);
404 	else
405 		sess = transport_init_session(prot_op);
406 
407 	if (IS_ERR(sess))
408 		return sess;
409 
410 	sess->se_node_acl = core_tpg_check_initiator_node_acl(tpg,
411 					(unsigned char *)initiatorname);
412 	if (!sess->se_node_acl) {
413 		transport_free_session(sess);
414 		return ERR_PTR(-EACCES);
415 	}
416 	/*
417 	 * Go ahead and perform any remaining fabric setup that is
418 	 * required before transport_register_session().
419 	 */
420 	if (callback != NULL) {
421 		int rc = callback(tpg, sess, private);
422 		if (rc) {
423 			transport_free_session(sess);
424 			return ERR_PTR(rc);
425 		}
426 	}
427 
428 	transport_register_session(tpg, sess->se_node_acl, sess, private);
429 	return sess;
430 }
431 EXPORT_SYMBOL(target_alloc_session);
432 
433 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
434 {
435 	struct se_session *se_sess;
436 	ssize_t len = 0;
437 
438 	spin_lock_bh(&se_tpg->session_lock);
439 	list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
440 		if (!se_sess->se_node_acl)
441 			continue;
442 		if (!se_sess->se_node_acl->dynamic_node_acl)
443 			continue;
444 		if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
445 			break;
446 
447 		len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
448 				se_sess->se_node_acl->initiatorname);
449 		len += 1; /* Include NULL terminator */
450 	}
451 	spin_unlock_bh(&se_tpg->session_lock);
452 
453 	return len;
454 }
455 EXPORT_SYMBOL(target_show_dynamic_sessions);
456 
457 static void target_complete_nacl(struct kref *kref)
458 {
459 	struct se_node_acl *nacl = container_of(kref,
460 				struct se_node_acl, acl_kref);
461 	struct se_portal_group *se_tpg = nacl->se_tpg;
462 
463 	if (!nacl->dynamic_stop) {
464 		complete(&nacl->acl_free_comp);
465 		return;
466 	}
467 
468 	mutex_lock(&se_tpg->acl_node_mutex);
469 	list_del(&nacl->acl_list);
470 	mutex_unlock(&se_tpg->acl_node_mutex);
471 
472 	core_tpg_wait_for_nacl_pr_ref(nacl);
473 	core_free_device_list_for_node(nacl, se_tpg);
474 	kfree(nacl);
475 }
476 
477 void target_put_nacl(struct se_node_acl *nacl)
478 {
479 	kref_put(&nacl->acl_kref, target_complete_nacl);
480 }
481 EXPORT_SYMBOL(target_put_nacl);
482 
483 void transport_deregister_session_configfs(struct se_session *se_sess)
484 {
485 	struct se_node_acl *se_nacl;
486 	unsigned long flags;
487 	/*
488 	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
489 	 */
490 	se_nacl = se_sess->se_node_acl;
491 	if (se_nacl) {
492 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
493 		if (!list_empty(&se_sess->sess_acl_list))
494 			list_del_init(&se_sess->sess_acl_list);
495 		/*
496 		 * If the session list is empty, then clear the pointer.
497 		 * Otherwise, set the struct se_session pointer from the tail
498 		 * element of the per struct se_node_acl active session list.
499 		 */
500 		if (list_empty(&se_nacl->acl_sess_list))
501 			se_nacl->nacl_sess = NULL;
502 		else {
503 			se_nacl->nacl_sess = container_of(
504 					se_nacl->acl_sess_list.prev,
505 					struct se_session, sess_acl_list);
506 		}
507 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
508 	}
509 }
510 EXPORT_SYMBOL(transport_deregister_session_configfs);
511 
512 void transport_free_session(struct se_session *se_sess)
513 {
514 	struct se_node_acl *se_nacl = se_sess->se_node_acl;
515 
516 	/*
517 	 * Drop the se_node_acl->nacl_kref obtained from within
518 	 * core_tpg_get_initiator_node_acl().
519 	 */
520 	if (se_nacl) {
521 		struct se_portal_group *se_tpg = se_nacl->se_tpg;
522 		const struct target_core_fabric_ops *se_tfo = se_tpg->se_tpg_tfo;
523 		unsigned long flags;
524 
525 		se_sess->se_node_acl = NULL;
526 
527 		/*
528 		 * Also determine if we need to drop the extra ->cmd_kref if
529 		 * it had been previously dynamically generated, and
530 		 * the endpoint is not caching dynamic ACLs.
531 		 */
532 		mutex_lock(&se_tpg->acl_node_mutex);
533 		if (se_nacl->dynamic_node_acl &&
534 		    !se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
535 			spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
536 			if (list_empty(&se_nacl->acl_sess_list))
537 				se_nacl->dynamic_stop = true;
538 			spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
539 
540 			if (se_nacl->dynamic_stop)
541 				list_del(&se_nacl->acl_list);
542 		}
543 		mutex_unlock(&se_tpg->acl_node_mutex);
544 
545 		if (se_nacl->dynamic_stop)
546 			target_put_nacl(se_nacl);
547 
548 		target_put_nacl(se_nacl);
549 	}
550 	if (se_sess->sess_cmd_map) {
551 		percpu_ida_destroy(&se_sess->sess_tag_pool);
552 		kvfree(se_sess->sess_cmd_map);
553 	}
554 	kmem_cache_free(se_sess_cache, se_sess);
555 }
556 EXPORT_SYMBOL(transport_free_session);
557 
558 void transport_deregister_session(struct se_session *se_sess)
559 {
560 	struct se_portal_group *se_tpg = se_sess->se_tpg;
561 	unsigned long flags;
562 
563 	if (!se_tpg) {
564 		transport_free_session(se_sess);
565 		return;
566 	}
567 
568 	spin_lock_irqsave(&se_tpg->session_lock, flags);
569 	list_del(&se_sess->sess_list);
570 	se_sess->se_tpg = NULL;
571 	se_sess->fabric_sess_ptr = NULL;
572 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
573 
574 	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
575 		se_tpg->se_tpg_tfo->get_fabric_name());
576 	/*
577 	 * If last kref is dropping now for an explicit NodeACL, awake sleeping
578 	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
579 	 * removal context from within transport_free_session() code.
580 	 *
581 	 * For dynamic ACL, target_put_nacl() uses target_complete_nacl()
582 	 * to release all remaining generate_node_acl=1 created ACL resources.
583 	 */
584 
585 	transport_free_session(se_sess);
586 }
587 EXPORT_SYMBOL(transport_deregister_session);
588 
589 static void target_remove_from_state_list(struct se_cmd *cmd)
590 {
591 	struct se_device *dev = cmd->se_dev;
592 	unsigned long flags;
593 
594 	if (!dev)
595 		return;
596 
597 	spin_lock_irqsave(&dev->execute_task_lock, flags);
598 	if (cmd->state_active) {
599 		list_del(&cmd->state_list);
600 		cmd->state_active = false;
601 	}
602 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
603 }
604 
605 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
606 {
607 	unsigned long flags;
608 
609 	target_remove_from_state_list(cmd);
610 
611 	/*
612 	 * Clear struct se_cmd->se_lun before the handoff to FE.
613 	 */
614 	cmd->se_lun = NULL;
615 
616 	spin_lock_irqsave(&cmd->t_state_lock, flags);
617 	/*
618 	 * Determine if frontend context caller is requesting the stopping of
619 	 * this command for frontend exceptions.
620 	 */
621 	if (cmd->transport_state & CMD_T_STOP) {
622 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
623 			__func__, __LINE__, cmd->tag);
624 
625 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
626 
627 		complete_all(&cmd->t_transport_stop_comp);
628 		return 1;
629 	}
630 	cmd->transport_state &= ~CMD_T_ACTIVE;
631 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
632 
633 	/*
634 	 * Some fabric modules like tcm_loop can release their internally
635 	 * allocated I/O reference and struct se_cmd now.
636 	 *
637 	 * Fabric modules are expected to return '1' here if the se_cmd being
638 	 * passed is released at this point, or zero if not being released.
639 	 */
640 	return cmd->se_tfo->check_stop_free(cmd);
641 }
642 
643 static void transport_lun_remove_cmd(struct se_cmd *cmd)
644 {
645 	struct se_lun *lun = cmd->se_lun;
646 
647 	if (!lun)
648 		return;
649 
650 	if (cmpxchg(&cmd->lun_ref_active, true, false))
651 		percpu_ref_put(&lun->lun_ref);
652 }
653 
654 int transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
655 {
656 	bool ack_kref = (cmd->se_cmd_flags & SCF_ACK_KREF);
657 	int ret = 0;
658 
659 	if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
660 		transport_lun_remove_cmd(cmd);
661 	/*
662 	 * Allow the fabric driver to unmap any resources before
663 	 * releasing the descriptor via TFO->release_cmd()
664 	 */
665 	if (remove)
666 		cmd->se_tfo->aborted_task(cmd);
667 
668 	if (transport_cmd_check_stop_to_fabric(cmd))
669 		return 1;
670 	if (remove && ack_kref)
671 		ret = transport_put_cmd(cmd);
672 
673 	return ret;
674 }
675 
676 static void target_complete_failure_work(struct work_struct *work)
677 {
678 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
679 
680 	transport_generic_request_failure(cmd,
681 			TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
682 }
683 
684 /*
685  * Used when asking transport to copy Sense Data from the underlying
686  * Linux/SCSI struct scsi_cmnd
687  */
688 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
689 {
690 	struct se_device *dev = cmd->se_dev;
691 
692 	WARN_ON(!cmd->se_lun);
693 
694 	if (!dev)
695 		return NULL;
696 
697 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
698 		return NULL;
699 
700 	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
701 
702 	pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
703 		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
704 	return cmd->sense_buffer;
705 }
706 
707 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
708 {
709 	struct se_device *dev = cmd->se_dev;
710 	int success = scsi_status == GOOD;
711 	unsigned long flags;
712 
713 	cmd->scsi_status = scsi_status;
714 
715 
716 	spin_lock_irqsave(&cmd->t_state_lock, flags);
717 
718 	if (dev && dev->transport->transport_complete) {
719 		dev->transport->transport_complete(cmd,
720 				cmd->t_data_sg,
721 				transport_get_sense_buffer(cmd));
722 		if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
723 			success = 1;
724 	}
725 
726 	/*
727 	 * Check for case where an explicit ABORT_TASK has been received
728 	 * and transport_wait_for_tasks() will be waiting for completion..
729 	 */
730 	if (cmd->transport_state & CMD_T_ABORTED ||
731 	    cmd->transport_state & CMD_T_STOP) {
732 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
733 		complete_all(&cmd->t_transport_stop_comp);
734 		return;
735 	} else if (!success) {
736 		INIT_WORK(&cmd->work, target_complete_failure_work);
737 	} else {
738 		INIT_WORK(&cmd->work, target_complete_ok_work);
739 	}
740 
741 	cmd->t_state = TRANSPORT_COMPLETE;
742 	cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
743 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
744 
745 	if (cmd->se_cmd_flags & SCF_USE_CPUID)
746 		queue_work_on(cmd->cpuid, target_completion_wq, &cmd->work);
747 	else
748 		queue_work(target_completion_wq, &cmd->work);
749 }
750 EXPORT_SYMBOL(target_complete_cmd);
751 
752 void target_complete_cmd_with_length(struct se_cmd *cmd, u8 scsi_status, int length)
753 {
754 	if (scsi_status == SAM_STAT_GOOD && length < cmd->data_length) {
755 		if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
756 			cmd->residual_count += cmd->data_length - length;
757 		} else {
758 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
759 			cmd->residual_count = cmd->data_length - length;
760 		}
761 
762 		cmd->data_length = length;
763 	}
764 
765 	target_complete_cmd(cmd, scsi_status);
766 }
767 EXPORT_SYMBOL(target_complete_cmd_with_length);
768 
769 static void target_add_to_state_list(struct se_cmd *cmd)
770 {
771 	struct se_device *dev = cmd->se_dev;
772 	unsigned long flags;
773 
774 	spin_lock_irqsave(&dev->execute_task_lock, flags);
775 	if (!cmd->state_active) {
776 		list_add_tail(&cmd->state_list, &dev->state_list);
777 		cmd->state_active = true;
778 	}
779 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
780 }
781 
782 /*
783  * Handle QUEUE_FULL / -EAGAIN and -ENOMEM status
784  */
785 static void transport_write_pending_qf(struct se_cmd *cmd);
786 static void transport_complete_qf(struct se_cmd *cmd);
787 
788 void target_qf_do_work(struct work_struct *work)
789 {
790 	struct se_device *dev = container_of(work, struct se_device,
791 					qf_work_queue);
792 	LIST_HEAD(qf_cmd_list);
793 	struct se_cmd *cmd, *cmd_tmp;
794 
795 	spin_lock_irq(&dev->qf_cmd_lock);
796 	list_splice_init(&dev->qf_cmd_list, &qf_cmd_list);
797 	spin_unlock_irq(&dev->qf_cmd_lock);
798 
799 	list_for_each_entry_safe(cmd, cmd_tmp, &qf_cmd_list, se_qf_node) {
800 		list_del(&cmd->se_qf_node);
801 		atomic_dec_mb(&dev->dev_qf_count);
802 
803 		pr_debug("Processing %s cmd: %p QUEUE_FULL in work queue"
804 			" context: %s\n", cmd->se_tfo->get_fabric_name(), cmd,
805 			(cmd->t_state == TRANSPORT_COMPLETE_QF_OK) ? "COMPLETE_OK" :
806 			(cmd->t_state == TRANSPORT_COMPLETE_QF_WP) ? "WRITE_PENDING"
807 			: "UNKNOWN");
808 
809 		if (cmd->t_state == TRANSPORT_COMPLETE_QF_WP)
810 			transport_write_pending_qf(cmd);
811 		else if (cmd->t_state == TRANSPORT_COMPLETE_QF_OK ||
812 			 cmd->t_state == TRANSPORT_COMPLETE_QF_ERR)
813 			transport_complete_qf(cmd);
814 	}
815 }
816 
817 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
818 {
819 	switch (cmd->data_direction) {
820 	case DMA_NONE:
821 		return "NONE";
822 	case DMA_FROM_DEVICE:
823 		return "READ";
824 	case DMA_TO_DEVICE:
825 		return "WRITE";
826 	case DMA_BIDIRECTIONAL:
827 		return "BIDI";
828 	default:
829 		break;
830 	}
831 
832 	return "UNKNOWN";
833 }
834 
835 void transport_dump_dev_state(
836 	struct se_device *dev,
837 	char *b,
838 	int *bl)
839 {
840 	*bl += sprintf(b + *bl, "Status: ");
841 	if (dev->export_count)
842 		*bl += sprintf(b + *bl, "ACTIVATED");
843 	else
844 		*bl += sprintf(b + *bl, "DEACTIVATED");
845 
846 	*bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
847 	*bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
848 		dev->dev_attrib.block_size,
849 		dev->dev_attrib.hw_max_sectors);
850 	*bl += sprintf(b + *bl, "        ");
851 }
852 
853 void transport_dump_vpd_proto_id(
854 	struct t10_vpd *vpd,
855 	unsigned char *p_buf,
856 	int p_buf_len)
857 {
858 	unsigned char buf[VPD_TMP_BUF_SIZE];
859 	int len;
860 
861 	memset(buf, 0, VPD_TMP_BUF_SIZE);
862 	len = sprintf(buf, "T10 VPD Protocol Identifier: ");
863 
864 	switch (vpd->protocol_identifier) {
865 	case 0x00:
866 		sprintf(buf+len, "Fibre Channel\n");
867 		break;
868 	case 0x10:
869 		sprintf(buf+len, "Parallel SCSI\n");
870 		break;
871 	case 0x20:
872 		sprintf(buf+len, "SSA\n");
873 		break;
874 	case 0x30:
875 		sprintf(buf+len, "IEEE 1394\n");
876 		break;
877 	case 0x40:
878 		sprintf(buf+len, "SCSI Remote Direct Memory Access"
879 				" Protocol\n");
880 		break;
881 	case 0x50:
882 		sprintf(buf+len, "Internet SCSI (iSCSI)\n");
883 		break;
884 	case 0x60:
885 		sprintf(buf+len, "SAS Serial SCSI Protocol\n");
886 		break;
887 	case 0x70:
888 		sprintf(buf+len, "Automation/Drive Interface Transport"
889 				" Protocol\n");
890 		break;
891 	case 0x80:
892 		sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
893 		break;
894 	default:
895 		sprintf(buf+len, "Unknown 0x%02x\n",
896 				vpd->protocol_identifier);
897 		break;
898 	}
899 
900 	if (p_buf)
901 		strncpy(p_buf, buf, p_buf_len);
902 	else
903 		pr_debug("%s", buf);
904 }
905 
906 void
907 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
908 {
909 	/*
910 	 * Check if the Protocol Identifier Valid (PIV) bit is set..
911 	 *
912 	 * from spc3r23.pdf section 7.5.1
913 	 */
914 	 if (page_83[1] & 0x80) {
915 		vpd->protocol_identifier = (page_83[0] & 0xf0);
916 		vpd->protocol_identifier_set = 1;
917 		transport_dump_vpd_proto_id(vpd, NULL, 0);
918 	}
919 }
920 EXPORT_SYMBOL(transport_set_vpd_proto_id);
921 
922 int transport_dump_vpd_assoc(
923 	struct t10_vpd *vpd,
924 	unsigned char *p_buf,
925 	int p_buf_len)
926 {
927 	unsigned char buf[VPD_TMP_BUF_SIZE];
928 	int ret = 0;
929 	int len;
930 
931 	memset(buf, 0, VPD_TMP_BUF_SIZE);
932 	len = sprintf(buf, "T10 VPD Identifier Association: ");
933 
934 	switch (vpd->association) {
935 	case 0x00:
936 		sprintf(buf+len, "addressed logical unit\n");
937 		break;
938 	case 0x10:
939 		sprintf(buf+len, "target port\n");
940 		break;
941 	case 0x20:
942 		sprintf(buf+len, "SCSI target device\n");
943 		break;
944 	default:
945 		sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
946 		ret = -EINVAL;
947 		break;
948 	}
949 
950 	if (p_buf)
951 		strncpy(p_buf, buf, p_buf_len);
952 	else
953 		pr_debug("%s", buf);
954 
955 	return ret;
956 }
957 
958 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
959 {
960 	/*
961 	 * The VPD identification association..
962 	 *
963 	 * from spc3r23.pdf Section 7.6.3.1 Table 297
964 	 */
965 	vpd->association = (page_83[1] & 0x30);
966 	return transport_dump_vpd_assoc(vpd, NULL, 0);
967 }
968 EXPORT_SYMBOL(transport_set_vpd_assoc);
969 
970 int transport_dump_vpd_ident_type(
971 	struct t10_vpd *vpd,
972 	unsigned char *p_buf,
973 	int p_buf_len)
974 {
975 	unsigned char buf[VPD_TMP_BUF_SIZE];
976 	int ret = 0;
977 	int len;
978 
979 	memset(buf, 0, VPD_TMP_BUF_SIZE);
980 	len = sprintf(buf, "T10 VPD Identifier Type: ");
981 
982 	switch (vpd->device_identifier_type) {
983 	case 0x00:
984 		sprintf(buf+len, "Vendor specific\n");
985 		break;
986 	case 0x01:
987 		sprintf(buf+len, "T10 Vendor ID based\n");
988 		break;
989 	case 0x02:
990 		sprintf(buf+len, "EUI-64 based\n");
991 		break;
992 	case 0x03:
993 		sprintf(buf+len, "NAA\n");
994 		break;
995 	case 0x04:
996 		sprintf(buf+len, "Relative target port identifier\n");
997 		break;
998 	case 0x08:
999 		sprintf(buf+len, "SCSI name string\n");
1000 		break;
1001 	default:
1002 		sprintf(buf+len, "Unsupported: 0x%02x\n",
1003 				vpd->device_identifier_type);
1004 		ret = -EINVAL;
1005 		break;
1006 	}
1007 
1008 	if (p_buf) {
1009 		if (p_buf_len < strlen(buf)+1)
1010 			return -EINVAL;
1011 		strncpy(p_buf, buf, p_buf_len);
1012 	} else {
1013 		pr_debug("%s", buf);
1014 	}
1015 
1016 	return ret;
1017 }
1018 
1019 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1020 {
1021 	/*
1022 	 * The VPD identifier type..
1023 	 *
1024 	 * from spc3r23.pdf Section 7.6.3.1 Table 298
1025 	 */
1026 	vpd->device_identifier_type = (page_83[1] & 0x0f);
1027 	return transport_dump_vpd_ident_type(vpd, NULL, 0);
1028 }
1029 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1030 
1031 int transport_dump_vpd_ident(
1032 	struct t10_vpd *vpd,
1033 	unsigned char *p_buf,
1034 	int p_buf_len)
1035 {
1036 	unsigned char buf[VPD_TMP_BUF_SIZE];
1037 	int ret = 0;
1038 
1039 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1040 
1041 	switch (vpd->device_identifier_code_set) {
1042 	case 0x01: /* Binary */
1043 		snprintf(buf, sizeof(buf),
1044 			"T10 VPD Binary Device Identifier: %s\n",
1045 			&vpd->device_identifier[0]);
1046 		break;
1047 	case 0x02: /* ASCII */
1048 		snprintf(buf, sizeof(buf),
1049 			"T10 VPD ASCII Device Identifier: %s\n",
1050 			&vpd->device_identifier[0]);
1051 		break;
1052 	case 0x03: /* UTF-8 */
1053 		snprintf(buf, sizeof(buf),
1054 			"T10 VPD UTF-8 Device Identifier: %s\n",
1055 			&vpd->device_identifier[0]);
1056 		break;
1057 	default:
1058 		sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1059 			" 0x%02x", vpd->device_identifier_code_set);
1060 		ret = -EINVAL;
1061 		break;
1062 	}
1063 
1064 	if (p_buf)
1065 		strncpy(p_buf, buf, p_buf_len);
1066 	else
1067 		pr_debug("%s", buf);
1068 
1069 	return ret;
1070 }
1071 
1072 int
1073 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1074 {
1075 	static const char hex_str[] = "0123456789abcdef";
1076 	int j = 0, i = 4; /* offset to start of the identifier */
1077 
1078 	/*
1079 	 * The VPD Code Set (encoding)
1080 	 *
1081 	 * from spc3r23.pdf Section 7.6.3.1 Table 296
1082 	 */
1083 	vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1084 	switch (vpd->device_identifier_code_set) {
1085 	case 0x01: /* Binary */
1086 		vpd->device_identifier[j++] =
1087 				hex_str[vpd->device_identifier_type];
1088 		while (i < (4 + page_83[3])) {
1089 			vpd->device_identifier[j++] =
1090 				hex_str[(page_83[i] & 0xf0) >> 4];
1091 			vpd->device_identifier[j++] =
1092 				hex_str[page_83[i] & 0x0f];
1093 			i++;
1094 		}
1095 		break;
1096 	case 0x02: /* ASCII */
1097 	case 0x03: /* UTF-8 */
1098 		while (i < (4 + page_83[3]))
1099 			vpd->device_identifier[j++] = page_83[i++];
1100 		break;
1101 	default:
1102 		break;
1103 	}
1104 
1105 	return transport_dump_vpd_ident(vpd, NULL, 0);
1106 }
1107 EXPORT_SYMBOL(transport_set_vpd_ident);
1108 
1109 static sense_reason_t
1110 target_check_max_data_sg_nents(struct se_cmd *cmd, struct se_device *dev,
1111 			       unsigned int size)
1112 {
1113 	u32 mtl;
1114 
1115 	if (!cmd->se_tfo->max_data_sg_nents)
1116 		return TCM_NO_SENSE;
1117 	/*
1118 	 * Check if fabric enforced maximum SGL entries per I/O descriptor
1119 	 * exceeds se_cmd->data_length.  If true, set SCF_UNDERFLOW_BIT +
1120 	 * residual_count and reduce original cmd->data_length to maximum
1121 	 * length based on single PAGE_SIZE entry scatter-lists.
1122 	 */
1123 	mtl = (cmd->se_tfo->max_data_sg_nents * PAGE_SIZE);
1124 	if (cmd->data_length > mtl) {
1125 		/*
1126 		 * If an existing CDB overflow is present, calculate new residual
1127 		 * based on CDB size minus fabric maximum transfer length.
1128 		 *
1129 		 * If an existing CDB underflow is present, calculate new residual
1130 		 * based on original cmd->data_length minus fabric maximum transfer
1131 		 * length.
1132 		 *
1133 		 * Otherwise, set the underflow residual based on cmd->data_length
1134 		 * minus fabric maximum transfer length.
1135 		 */
1136 		if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1137 			cmd->residual_count = (size - mtl);
1138 		} else if (cmd->se_cmd_flags & SCF_UNDERFLOW_BIT) {
1139 			u32 orig_dl = size + cmd->residual_count;
1140 			cmd->residual_count = (orig_dl - mtl);
1141 		} else {
1142 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1143 			cmd->residual_count = (cmd->data_length - mtl);
1144 		}
1145 		cmd->data_length = mtl;
1146 		/*
1147 		 * Reset sbc_check_prot() calculated protection payload
1148 		 * length based upon the new smaller MTL.
1149 		 */
1150 		if (cmd->prot_length) {
1151 			u32 sectors = (mtl / dev->dev_attrib.block_size);
1152 			cmd->prot_length = dev->prot_length * sectors;
1153 		}
1154 	}
1155 	return TCM_NO_SENSE;
1156 }
1157 
1158 sense_reason_t
1159 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1160 {
1161 	struct se_device *dev = cmd->se_dev;
1162 
1163 	if (cmd->unknown_data_length) {
1164 		cmd->data_length = size;
1165 	} else if (size != cmd->data_length) {
1166 		pr_warn_ratelimited("TARGET_CORE[%s]: Expected Transfer Length:"
1167 			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
1168 			" 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1169 				cmd->data_length, size, cmd->t_task_cdb[0]);
1170 
1171 		if (cmd->data_direction == DMA_TO_DEVICE) {
1172 			if (cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) {
1173 				pr_err_ratelimited("Rejecting underflow/overflow"
1174 						   " for WRITE data CDB\n");
1175 				return TCM_INVALID_CDB_FIELD;
1176 			}
1177 			/*
1178 			 * Some fabric drivers like iscsi-target still expect to
1179 			 * always reject overflow writes.  Reject this case until
1180 			 * full fabric driver level support for overflow writes
1181 			 * is introduced tree-wide.
1182 			 */
1183 			if (size > cmd->data_length) {
1184 				pr_err_ratelimited("Rejecting overflow for"
1185 						   " WRITE control CDB\n");
1186 				return TCM_INVALID_CDB_FIELD;
1187 			}
1188 		}
1189 		/*
1190 		 * Reject READ_* or WRITE_* with overflow/underflow for
1191 		 * type SCF_SCSI_DATA_CDB.
1192 		 */
1193 		if (dev->dev_attrib.block_size != 512)  {
1194 			pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1195 				" CDB on non 512-byte sector setup subsystem"
1196 				" plugin: %s\n", dev->transport->name);
1197 			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1198 			return TCM_INVALID_CDB_FIELD;
1199 		}
1200 		/*
1201 		 * For the overflow case keep the existing fabric provided
1202 		 * ->data_length.  Otherwise for the underflow case, reset
1203 		 * ->data_length to the smaller SCSI expected data transfer
1204 		 * length.
1205 		 */
1206 		if (size > cmd->data_length) {
1207 			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1208 			cmd->residual_count = (size - cmd->data_length);
1209 		} else {
1210 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1211 			cmd->residual_count = (cmd->data_length - size);
1212 			cmd->data_length = size;
1213 		}
1214 	}
1215 
1216 	return target_check_max_data_sg_nents(cmd, dev, size);
1217 
1218 }
1219 
1220 /*
1221  * Used by fabric modules containing a local struct se_cmd within their
1222  * fabric dependent per I/O descriptor.
1223  *
1224  * Preserves the value of @cmd->tag.
1225  */
1226 void transport_init_se_cmd(
1227 	struct se_cmd *cmd,
1228 	const struct target_core_fabric_ops *tfo,
1229 	struct se_session *se_sess,
1230 	u32 data_length,
1231 	int data_direction,
1232 	int task_attr,
1233 	unsigned char *sense_buffer)
1234 {
1235 	INIT_LIST_HEAD(&cmd->se_delayed_node);
1236 	INIT_LIST_HEAD(&cmd->se_qf_node);
1237 	INIT_LIST_HEAD(&cmd->se_cmd_list);
1238 	INIT_LIST_HEAD(&cmd->state_list);
1239 	init_completion(&cmd->t_transport_stop_comp);
1240 	init_completion(&cmd->cmd_wait_comp);
1241 	spin_lock_init(&cmd->t_state_lock);
1242 	kref_init(&cmd->cmd_kref);
1243 
1244 	cmd->se_tfo = tfo;
1245 	cmd->se_sess = se_sess;
1246 	cmd->data_length = data_length;
1247 	cmd->data_direction = data_direction;
1248 	cmd->sam_task_attr = task_attr;
1249 	cmd->sense_buffer = sense_buffer;
1250 
1251 	cmd->state_active = false;
1252 }
1253 EXPORT_SYMBOL(transport_init_se_cmd);
1254 
1255 static sense_reason_t
1256 transport_check_alloc_task_attr(struct se_cmd *cmd)
1257 {
1258 	struct se_device *dev = cmd->se_dev;
1259 
1260 	/*
1261 	 * Check if SAM Task Attribute emulation is enabled for this
1262 	 * struct se_device storage object
1263 	 */
1264 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1265 		return 0;
1266 
1267 	if (cmd->sam_task_attr == TCM_ACA_TAG) {
1268 		pr_debug("SAM Task Attribute ACA"
1269 			" emulation is not supported\n");
1270 		return TCM_INVALID_CDB_FIELD;
1271 	}
1272 
1273 	return 0;
1274 }
1275 
1276 sense_reason_t
1277 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1278 {
1279 	struct se_device *dev = cmd->se_dev;
1280 	sense_reason_t ret;
1281 
1282 	/*
1283 	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1284 	 * for VARIABLE_LENGTH_CMD
1285 	 */
1286 	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1287 		pr_err("Received SCSI CDB with command_size: %d that"
1288 			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1289 			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1290 		return TCM_INVALID_CDB_FIELD;
1291 	}
1292 	/*
1293 	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1294 	 * allocate the additional extended CDB buffer now..  Otherwise
1295 	 * setup the pointer from __t_task_cdb to t_task_cdb.
1296 	 */
1297 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1298 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1299 						GFP_KERNEL);
1300 		if (!cmd->t_task_cdb) {
1301 			pr_err("Unable to allocate cmd->t_task_cdb"
1302 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1303 				scsi_command_size(cdb),
1304 				(unsigned long)sizeof(cmd->__t_task_cdb));
1305 			return TCM_OUT_OF_RESOURCES;
1306 		}
1307 	} else
1308 		cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1309 	/*
1310 	 * Copy the original CDB into cmd->
1311 	 */
1312 	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1313 
1314 	trace_target_sequencer_start(cmd);
1315 
1316 	ret = dev->transport->parse_cdb(cmd);
1317 	if (ret == TCM_UNSUPPORTED_SCSI_OPCODE)
1318 		pr_warn_ratelimited("%s/%s: Unsupported SCSI Opcode 0x%02x, sending CHECK_CONDITION.\n",
1319 				    cmd->se_tfo->get_fabric_name(),
1320 				    cmd->se_sess->se_node_acl->initiatorname,
1321 				    cmd->t_task_cdb[0]);
1322 	if (ret)
1323 		return ret;
1324 
1325 	ret = transport_check_alloc_task_attr(cmd);
1326 	if (ret)
1327 		return ret;
1328 
1329 	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1330 	atomic_long_inc(&cmd->se_lun->lun_stats.cmd_pdus);
1331 	return 0;
1332 }
1333 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1334 
1335 /*
1336  * Used by fabric module frontends to queue tasks directly.
1337  * May only be used from process context.
1338  */
1339 int transport_handle_cdb_direct(
1340 	struct se_cmd *cmd)
1341 {
1342 	sense_reason_t ret;
1343 
1344 	if (!cmd->se_lun) {
1345 		dump_stack();
1346 		pr_err("cmd->se_lun is NULL\n");
1347 		return -EINVAL;
1348 	}
1349 	if (in_interrupt()) {
1350 		dump_stack();
1351 		pr_err("transport_generic_handle_cdb cannot be called"
1352 				" from interrupt context\n");
1353 		return -EINVAL;
1354 	}
1355 	/*
1356 	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1357 	 * outstanding descriptors are handled correctly during shutdown via
1358 	 * transport_wait_for_tasks()
1359 	 *
1360 	 * Also, we don't take cmd->t_state_lock here as we only expect
1361 	 * this to be called for initial descriptor submission.
1362 	 */
1363 	cmd->t_state = TRANSPORT_NEW_CMD;
1364 	cmd->transport_state |= CMD_T_ACTIVE;
1365 
1366 	/*
1367 	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1368 	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1369 	 * and call transport_generic_request_failure() if necessary..
1370 	 */
1371 	ret = transport_generic_new_cmd(cmd);
1372 	if (ret)
1373 		transport_generic_request_failure(cmd, ret);
1374 	return 0;
1375 }
1376 EXPORT_SYMBOL(transport_handle_cdb_direct);
1377 
1378 sense_reason_t
1379 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1380 		u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1381 {
1382 	if (!sgl || !sgl_count)
1383 		return 0;
1384 
1385 	/*
1386 	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1387 	 * scatterlists already have been set to follow what the fabric
1388 	 * passes for the original expected data transfer length.
1389 	 */
1390 	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1391 		pr_warn("Rejecting SCSI DATA overflow for fabric using"
1392 			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1393 		return TCM_INVALID_CDB_FIELD;
1394 	}
1395 
1396 	cmd->t_data_sg = sgl;
1397 	cmd->t_data_nents = sgl_count;
1398 	cmd->t_bidi_data_sg = sgl_bidi;
1399 	cmd->t_bidi_data_nents = sgl_bidi_count;
1400 
1401 	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1402 	return 0;
1403 }
1404 
1405 /*
1406  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1407  * 			 se_cmd + use pre-allocated SGL memory.
1408  *
1409  * @se_cmd: command descriptor to submit
1410  * @se_sess: associated se_sess for endpoint
1411  * @cdb: pointer to SCSI CDB
1412  * @sense: pointer to SCSI sense buffer
1413  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1414  * @data_length: fabric expected data transfer length
1415  * @task_addr: SAM task attribute
1416  * @data_dir: DMA data direction
1417  * @flags: flags for command submission from target_sc_flags_tables
1418  * @sgl: struct scatterlist memory for unidirectional mapping
1419  * @sgl_count: scatterlist count for unidirectional mapping
1420  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1421  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1422  * @sgl_prot: struct scatterlist memory protection information
1423  * @sgl_prot_count: scatterlist count for protection information
1424  *
1425  * Task tags are supported if the caller has set @se_cmd->tag.
1426  *
1427  * Returns non zero to signal active I/O shutdown failure.  All other
1428  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1429  * but still return zero here.
1430  *
1431  * This may only be called from process context, and also currently
1432  * assumes internal allocation of fabric payload buffer by target-core.
1433  */
1434 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1435 		unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1436 		u32 data_length, int task_attr, int data_dir, int flags,
1437 		struct scatterlist *sgl, u32 sgl_count,
1438 		struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1439 		struct scatterlist *sgl_prot, u32 sgl_prot_count)
1440 {
1441 	struct se_portal_group *se_tpg;
1442 	sense_reason_t rc;
1443 	int ret;
1444 
1445 	se_tpg = se_sess->se_tpg;
1446 	BUG_ON(!se_tpg);
1447 	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1448 	BUG_ON(in_interrupt());
1449 	/*
1450 	 * Initialize se_cmd for target operation.  From this point
1451 	 * exceptions are handled by sending exception status via
1452 	 * target_core_fabric_ops->queue_status() callback
1453 	 */
1454 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1455 				data_length, data_dir, task_attr, sense);
1456 
1457 	if (flags & TARGET_SCF_USE_CPUID)
1458 		se_cmd->se_cmd_flags |= SCF_USE_CPUID;
1459 	else
1460 		se_cmd->cpuid = WORK_CPU_UNBOUND;
1461 
1462 	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1463 		se_cmd->unknown_data_length = 1;
1464 	/*
1465 	 * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1466 	 * se_sess->sess_cmd_list.  A second kref_get here is necessary
1467 	 * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1468 	 * kref_put() to happen during fabric packet acknowledgement.
1469 	 */
1470 	ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1471 	if (ret)
1472 		return ret;
1473 	/*
1474 	 * Signal bidirectional data payloads to target-core
1475 	 */
1476 	if (flags & TARGET_SCF_BIDI_OP)
1477 		se_cmd->se_cmd_flags |= SCF_BIDI;
1478 	/*
1479 	 * Locate se_lun pointer and attach it to struct se_cmd
1480 	 */
1481 	rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1482 	if (rc) {
1483 		transport_send_check_condition_and_sense(se_cmd, rc, 0);
1484 		target_put_sess_cmd(se_cmd);
1485 		return 0;
1486 	}
1487 
1488 	rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1489 	if (rc != 0) {
1490 		transport_generic_request_failure(se_cmd, rc);
1491 		return 0;
1492 	}
1493 
1494 	/*
1495 	 * Save pointers for SGLs containing protection information,
1496 	 * if present.
1497 	 */
1498 	if (sgl_prot_count) {
1499 		se_cmd->t_prot_sg = sgl_prot;
1500 		se_cmd->t_prot_nents = sgl_prot_count;
1501 		se_cmd->se_cmd_flags |= SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC;
1502 	}
1503 
1504 	/*
1505 	 * When a non zero sgl_count has been passed perform SGL passthrough
1506 	 * mapping for pre-allocated fabric memory instead of having target
1507 	 * core perform an internal SGL allocation..
1508 	 */
1509 	if (sgl_count != 0) {
1510 		BUG_ON(!sgl);
1511 
1512 		/*
1513 		 * A work-around for tcm_loop as some userspace code via
1514 		 * scsi-generic do not memset their associated read buffers,
1515 		 * so go ahead and do that here for type non-data CDBs.  Also
1516 		 * note that this is currently guaranteed to be a single SGL
1517 		 * for this case by target core in target_setup_cmd_from_cdb()
1518 		 * -> transport_generic_cmd_sequencer().
1519 		 */
1520 		if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1521 		     se_cmd->data_direction == DMA_FROM_DEVICE) {
1522 			unsigned char *buf = NULL;
1523 
1524 			if (sgl)
1525 				buf = kmap(sg_page(sgl)) + sgl->offset;
1526 
1527 			if (buf) {
1528 				memset(buf, 0, sgl->length);
1529 				kunmap(sg_page(sgl));
1530 			}
1531 		}
1532 
1533 		rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1534 				sgl_bidi, sgl_bidi_count);
1535 		if (rc != 0) {
1536 			transport_generic_request_failure(se_cmd, rc);
1537 			return 0;
1538 		}
1539 	}
1540 
1541 	/*
1542 	 * Check if we need to delay processing because of ALUA
1543 	 * Active/NonOptimized primary access state..
1544 	 */
1545 	core_alua_check_nonop_delay(se_cmd);
1546 
1547 	transport_handle_cdb_direct(se_cmd);
1548 	return 0;
1549 }
1550 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1551 
1552 /*
1553  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1554  *
1555  * @se_cmd: command descriptor to submit
1556  * @se_sess: associated se_sess for endpoint
1557  * @cdb: pointer to SCSI CDB
1558  * @sense: pointer to SCSI sense buffer
1559  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1560  * @data_length: fabric expected data transfer length
1561  * @task_addr: SAM task attribute
1562  * @data_dir: DMA data direction
1563  * @flags: flags for command submission from target_sc_flags_tables
1564  *
1565  * Task tags are supported if the caller has set @se_cmd->tag.
1566  *
1567  * Returns non zero to signal active I/O shutdown failure.  All other
1568  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1569  * but still return zero here.
1570  *
1571  * This may only be called from process context, and also currently
1572  * assumes internal allocation of fabric payload buffer by target-core.
1573  *
1574  * It also assumes interal target core SGL memory allocation.
1575  */
1576 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1577 		unsigned char *cdb, unsigned char *sense, u64 unpacked_lun,
1578 		u32 data_length, int task_attr, int data_dir, int flags)
1579 {
1580 	return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1581 			unpacked_lun, data_length, task_attr, data_dir,
1582 			flags, NULL, 0, NULL, 0, NULL, 0);
1583 }
1584 EXPORT_SYMBOL(target_submit_cmd);
1585 
1586 static void target_complete_tmr_failure(struct work_struct *work)
1587 {
1588 	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1589 
1590 	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1591 	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1592 
1593 	transport_cmd_check_stop_to_fabric(se_cmd);
1594 }
1595 
1596 /**
1597  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1598  *                     for TMR CDBs
1599  *
1600  * @se_cmd: command descriptor to submit
1601  * @se_sess: associated se_sess for endpoint
1602  * @sense: pointer to SCSI sense buffer
1603  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1604  * @fabric_context: fabric context for TMR req
1605  * @tm_type: Type of TM request
1606  * @gfp: gfp type for caller
1607  * @tag: referenced task tag for TMR_ABORT_TASK
1608  * @flags: submit cmd flags
1609  *
1610  * Callable from all contexts.
1611  **/
1612 
1613 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1614 		unsigned char *sense, u64 unpacked_lun,
1615 		void *fabric_tmr_ptr, unsigned char tm_type,
1616 		gfp_t gfp, u64 tag, int flags)
1617 {
1618 	struct se_portal_group *se_tpg;
1619 	int ret;
1620 
1621 	se_tpg = se_sess->se_tpg;
1622 	BUG_ON(!se_tpg);
1623 
1624 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1625 			      0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1626 	/*
1627 	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1628 	 * allocation failure.
1629 	 */
1630 	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1631 	if (ret < 0)
1632 		return -ENOMEM;
1633 
1634 	if (tm_type == TMR_ABORT_TASK)
1635 		se_cmd->se_tmr_req->ref_task_tag = tag;
1636 
1637 	/* See target_submit_cmd for commentary */
1638 	ret = target_get_sess_cmd(se_cmd, flags & TARGET_SCF_ACK_KREF);
1639 	if (ret) {
1640 		core_tmr_release_req(se_cmd->se_tmr_req);
1641 		return ret;
1642 	}
1643 
1644 	ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1645 	if (ret) {
1646 		/*
1647 		 * For callback during failure handling, push this work off
1648 		 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1649 		 */
1650 		INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1651 		schedule_work(&se_cmd->work);
1652 		return 0;
1653 	}
1654 	transport_generic_handle_tmr(se_cmd);
1655 	return 0;
1656 }
1657 EXPORT_SYMBOL(target_submit_tmr);
1658 
1659 /*
1660  * Handle SAM-esque emulation for generic transport request failures.
1661  */
1662 void transport_generic_request_failure(struct se_cmd *cmd,
1663 		sense_reason_t sense_reason)
1664 {
1665 	int ret = 0, post_ret = 0;
1666 
1667 	if (transport_check_aborted_status(cmd, 1))
1668 		return;
1669 
1670 	pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08llx"
1671 		" CDB: 0x%02x\n", cmd, cmd->tag, cmd->t_task_cdb[0]);
1672 	pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1673 		cmd->se_tfo->get_cmd_state(cmd),
1674 		cmd->t_state, sense_reason);
1675 	pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1676 		(cmd->transport_state & CMD_T_ACTIVE) != 0,
1677 		(cmd->transport_state & CMD_T_STOP) != 0,
1678 		(cmd->transport_state & CMD_T_SENT) != 0);
1679 
1680 	/*
1681 	 * For SAM Task Attribute emulation for failed struct se_cmd
1682 	 */
1683 	transport_complete_task_attr(cmd);
1684 	/*
1685 	 * Handle special case for COMPARE_AND_WRITE failure, where the
1686 	 * callback is expected to drop the per device ->caw_sem.
1687 	 */
1688 	if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1689 	     cmd->transport_complete_callback)
1690 		cmd->transport_complete_callback(cmd, false, &post_ret);
1691 
1692 	switch (sense_reason) {
1693 	case TCM_NON_EXISTENT_LUN:
1694 	case TCM_UNSUPPORTED_SCSI_OPCODE:
1695 	case TCM_INVALID_CDB_FIELD:
1696 	case TCM_INVALID_PARAMETER_LIST:
1697 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
1698 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1699 	case TCM_UNKNOWN_MODE_PAGE:
1700 	case TCM_WRITE_PROTECTED:
1701 	case TCM_ADDRESS_OUT_OF_RANGE:
1702 	case TCM_CHECK_CONDITION_ABORT_CMD:
1703 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1704 	case TCM_CHECK_CONDITION_NOT_READY:
1705 	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1706 	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1707 	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1708 	case TCM_COPY_TARGET_DEVICE_NOT_REACHABLE:
1709 	case TCM_TOO_MANY_TARGET_DESCS:
1710 	case TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE:
1711 	case TCM_TOO_MANY_SEGMENT_DESCS:
1712 	case TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE:
1713 		break;
1714 	case TCM_OUT_OF_RESOURCES:
1715 		sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1716 		break;
1717 	case TCM_RESERVATION_CONFLICT:
1718 		/*
1719 		 * No SENSE Data payload for this case, set SCSI Status
1720 		 * and queue the response to $FABRIC_MOD.
1721 		 *
1722 		 * Uses linux/include/scsi/scsi.h SAM status codes defs
1723 		 */
1724 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1725 		/*
1726 		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1727 		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1728 		 * CONFLICT STATUS.
1729 		 *
1730 		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1731 		 */
1732 		if (cmd->se_sess &&
1733 		    cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2) {
1734 			target_ua_allocate_lun(cmd->se_sess->se_node_acl,
1735 					       cmd->orig_fe_lun, 0x2C,
1736 					ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1737 		}
1738 		trace_target_cmd_complete(cmd);
1739 		ret = cmd->se_tfo->queue_status(cmd);
1740 		if (ret)
1741 			goto queue_full;
1742 		goto check_stop;
1743 	default:
1744 		pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1745 			cmd->t_task_cdb[0], sense_reason);
1746 		sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1747 		break;
1748 	}
1749 
1750 	ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1751 	if (ret)
1752 		goto queue_full;
1753 
1754 check_stop:
1755 	transport_lun_remove_cmd(cmd);
1756 	transport_cmd_check_stop_to_fabric(cmd);
1757 	return;
1758 
1759 queue_full:
1760 	transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
1761 }
1762 EXPORT_SYMBOL(transport_generic_request_failure);
1763 
1764 void __target_execute_cmd(struct se_cmd *cmd, bool do_checks)
1765 {
1766 	sense_reason_t ret;
1767 
1768 	if (!cmd->execute_cmd) {
1769 		ret = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1770 		goto err;
1771 	}
1772 	if (do_checks) {
1773 		/*
1774 		 * Check for an existing UNIT ATTENTION condition after
1775 		 * target_handle_task_attr() has done SAM task attr
1776 		 * checking, and possibly have already defered execution
1777 		 * out to target_restart_delayed_cmds() context.
1778 		 */
1779 		ret = target_scsi3_ua_check(cmd);
1780 		if (ret)
1781 			goto err;
1782 
1783 		ret = target_alua_state_check(cmd);
1784 		if (ret)
1785 			goto err;
1786 
1787 		ret = target_check_reservation(cmd);
1788 		if (ret) {
1789 			cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1790 			goto err;
1791 		}
1792 	}
1793 
1794 	ret = cmd->execute_cmd(cmd);
1795 	if (!ret)
1796 		return;
1797 err:
1798 	spin_lock_irq(&cmd->t_state_lock);
1799 	cmd->transport_state &= ~CMD_T_SENT;
1800 	spin_unlock_irq(&cmd->t_state_lock);
1801 
1802 	transport_generic_request_failure(cmd, ret);
1803 }
1804 
1805 static int target_write_prot_action(struct se_cmd *cmd)
1806 {
1807 	u32 sectors;
1808 	/*
1809 	 * Perform WRITE_INSERT of PI using software emulation when backend
1810 	 * device has PI enabled, if the transport has not already generated
1811 	 * PI using hardware WRITE_INSERT offload.
1812 	 */
1813 	switch (cmd->prot_op) {
1814 	case TARGET_PROT_DOUT_INSERT:
1815 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1816 			sbc_dif_generate(cmd);
1817 		break;
1818 	case TARGET_PROT_DOUT_STRIP:
1819 		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1820 			break;
1821 
1822 		sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1823 		cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
1824 					     sectors, 0, cmd->t_prot_sg, 0);
1825 		if (unlikely(cmd->pi_err)) {
1826 			spin_lock_irq(&cmd->t_state_lock);
1827 			cmd->transport_state &= ~CMD_T_SENT;
1828 			spin_unlock_irq(&cmd->t_state_lock);
1829 			transport_generic_request_failure(cmd, cmd->pi_err);
1830 			return -1;
1831 		}
1832 		break;
1833 	default:
1834 		break;
1835 	}
1836 
1837 	return 0;
1838 }
1839 
1840 static bool target_handle_task_attr(struct se_cmd *cmd)
1841 {
1842 	struct se_device *dev = cmd->se_dev;
1843 
1844 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1845 		return false;
1846 
1847 	cmd->se_cmd_flags |= SCF_TASK_ATTR_SET;
1848 
1849 	/*
1850 	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1851 	 * to allow the passed struct se_cmd list of tasks to the front of the list.
1852 	 */
1853 	switch (cmd->sam_task_attr) {
1854 	case TCM_HEAD_TAG:
1855 		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x\n",
1856 			 cmd->t_task_cdb[0]);
1857 		return false;
1858 	case TCM_ORDERED_TAG:
1859 		atomic_inc_mb(&dev->dev_ordered_sync);
1860 
1861 		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list\n",
1862 			 cmd->t_task_cdb[0]);
1863 
1864 		/*
1865 		 * Execute an ORDERED command if no other older commands
1866 		 * exist that need to be completed first.
1867 		 */
1868 		if (!atomic_read(&dev->simple_cmds))
1869 			return false;
1870 		break;
1871 	default:
1872 		/*
1873 		 * For SIMPLE and UNTAGGED Task Attribute commands
1874 		 */
1875 		atomic_inc_mb(&dev->simple_cmds);
1876 		break;
1877 	}
1878 
1879 	if (atomic_read(&dev->dev_ordered_sync) == 0)
1880 		return false;
1881 
1882 	spin_lock(&dev->delayed_cmd_lock);
1883 	list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1884 	spin_unlock(&dev->delayed_cmd_lock);
1885 
1886 	pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to delayed CMD listn",
1887 		cmd->t_task_cdb[0], cmd->sam_task_attr);
1888 	return true;
1889 }
1890 
1891 static int __transport_check_aborted_status(struct se_cmd *, int);
1892 
1893 void target_execute_cmd(struct se_cmd *cmd)
1894 {
1895 	/*
1896 	 * Determine if frontend context caller is requesting the stopping of
1897 	 * this command for frontend exceptions.
1898 	 *
1899 	 * If the received CDB has aleady been aborted stop processing it here.
1900 	 */
1901 	spin_lock_irq(&cmd->t_state_lock);
1902 	if (__transport_check_aborted_status(cmd, 1)) {
1903 		spin_unlock_irq(&cmd->t_state_lock);
1904 		return;
1905 	}
1906 	if (cmd->transport_state & CMD_T_STOP) {
1907 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
1908 			__func__, __LINE__, cmd->tag);
1909 
1910 		spin_unlock_irq(&cmd->t_state_lock);
1911 		complete_all(&cmd->t_transport_stop_comp);
1912 		return;
1913 	}
1914 
1915 	cmd->t_state = TRANSPORT_PROCESSING;
1916 	cmd->transport_state |= CMD_T_ACTIVE | CMD_T_SENT;
1917 	spin_unlock_irq(&cmd->t_state_lock);
1918 
1919 	if (target_write_prot_action(cmd))
1920 		return;
1921 
1922 	if (target_handle_task_attr(cmd)) {
1923 		spin_lock_irq(&cmd->t_state_lock);
1924 		cmd->transport_state &= ~CMD_T_SENT;
1925 		spin_unlock_irq(&cmd->t_state_lock);
1926 		return;
1927 	}
1928 
1929 	__target_execute_cmd(cmd, true);
1930 }
1931 EXPORT_SYMBOL(target_execute_cmd);
1932 
1933 /*
1934  * Process all commands up to the last received ORDERED task attribute which
1935  * requires another blocking boundary
1936  */
1937 static void target_restart_delayed_cmds(struct se_device *dev)
1938 {
1939 	for (;;) {
1940 		struct se_cmd *cmd;
1941 
1942 		spin_lock(&dev->delayed_cmd_lock);
1943 		if (list_empty(&dev->delayed_cmd_list)) {
1944 			spin_unlock(&dev->delayed_cmd_lock);
1945 			break;
1946 		}
1947 
1948 		cmd = list_entry(dev->delayed_cmd_list.next,
1949 				 struct se_cmd, se_delayed_node);
1950 		list_del(&cmd->se_delayed_node);
1951 		spin_unlock(&dev->delayed_cmd_lock);
1952 
1953 		__target_execute_cmd(cmd, true);
1954 
1955 		if (cmd->sam_task_attr == TCM_ORDERED_TAG)
1956 			break;
1957 	}
1958 }
1959 
1960 /*
1961  * Called from I/O completion to determine which dormant/delayed
1962  * and ordered cmds need to have their tasks added to the execution queue.
1963  */
1964 static void transport_complete_task_attr(struct se_cmd *cmd)
1965 {
1966 	struct se_device *dev = cmd->se_dev;
1967 
1968 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1969 		return;
1970 
1971 	if (!(cmd->se_cmd_flags & SCF_TASK_ATTR_SET))
1972 		goto restart;
1973 
1974 	if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
1975 		atomic_dec_mb(&dev->simple_cmds);
1976 		dev->dev_cur_ordered_id++;
1977 	} else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
1978 		dev->dev_cur_ordered_id++;
1979 		pr_debug("Incremented dev_cur_ordered_id: %u for HEAD_OF_QUEUE\n",
1980 			 dev->dev_cur_ordered_id);
1981 	} else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
1982 		atomic_dec_mb(&dev->dev_ordered_sync);
1983 
1984 		dev->dev_cur_ordered_id++;
1985 		pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED\n",
1986 			 dev->dev_cur_ordered_id);
1987 	}
1988 restart:
1989 	target_restart_delayed_cmds(dev);
1990 }
1991 
1992 static void transport_complete_qf(struct se_cmd *cmd)
1993 {
1994 	int ret = 0;
1995 
1996 	transport_complete_task_attr(cmd);
1997 	/*
1998 	 * If a fabric driver ->write_pending() or ->queue_data_in() callback
1999 	 * has returned neither -ENOMEM or -EAGAIN, assume it's fatal and
2000 	 * the same callbacks should not be retried.  Return CHECK_CONDITION
2001 	 * if a scsi_status is not already set.
2002 	 *
2003 	 * If a fabric driver ->queue_status() has returned non zero, always
2004 	 * keep retrying no matter what..
2005 	 */
2006 	if (cmd->t_state == TRANSPORT_COMPLETE_QF_ERR) {
2007 		if (cmd->scsi_status)
2008 			goto queue_status;
2009 
2010 		cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2011 		cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2012 		cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2013 		translate_sense_reason(cmd, TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
2014 		goto queue_status;
2015 	}
2016 
2017 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
2018 		goto queue_status;
2019 
2020 	switch (cmd->data_direction) {
2021 	case DMA_FROM_DEVICE:
2022 		if (cmd->scsi_status)
2023 			goto queue_status;
2024 
2025 		trace_target_cmd_complete(cmd);
2026 		ret = cmd->se_tfo->queue_data_in(cmd);
2027 		break;
2028 	case DMA_TO_DEVICE:
2029 		if (cmd->se_cmd_flags & SCF_BIDI) {
2030 			ret = cmd->se_tfo->queue_data_in(cmd);
2031 			break;
2032 		}
2033 		/* Fall through for DMA_TO_DEVICE */
2034 	case DMA_NONE:
2035 queue_status:
2036 		trace_target_cmd_complete(cmd);
2037 		ret = cmd->se_tfo->queue_status(cmd);
2038 		break;
2039 	default:
2040 		break;
2041 	}
2042 
2043 	if (ret < 0) {
2044 		transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2045 		return;
2046 	}
2047 	transport_lun_remove_cmd(cmd);
2048 	transport_cmd_check_stop_to_fabric(cmd);
2049 }
2050 
2051 static void transport_handle_queue_full(struct se_cmd *cmd, struct se_device *dev,
2052 					int err, bool write_pending)
2053 {
2054 	/*
2055 	 * -EAGAIN or -ENOMEM signals retry of ->write_pending() and/or
2056 	 * ->queue_data_in() callbacks from new process context.
2057 	 *
2058 	 * Otherwise for other errors, transport_complete_qf() will send
2059 	 * CHECK_CONDITION via ->queue_status() instead of attempting to
2060 	 * retry associated fabric driver data-transfer callbacks.
2061 	 */
2062 	if (err == -EAGAIN || err == -ENOMEM) {
2063 		cmd->t_state = (write_pending) ? TRANSPORT_COMPLETE_QF_WP :
2064 						 TRANSPORT_COMPLETE_QF_OK;
2065 	} else {
2066 		pr_warn_ratelimited("Got unknown fabric queue status: %d\n", err);
2067 		cmd->t_state = TRANSPORT_COMPLETE_QF_ERR;
2068 	}
2069 
2070 	spin_lock_irq(&dev->qf_cmd_lock);
2071 	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
2072 	atomic_inc_mb(&dev->dev_qf_count);
2073 	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
2074 
2075 	schedule_work(&cmd->se_dev->qf_work_queue);
2076 }
2077 
2078 static bool target_read_prot_action(struct se_cmd *cmd)
2079 {
2080 	switch (cmd->prot_op) {
2081 	case TARGET_PROT_DIN_STRIP:
2082 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
2083 			u32 sectors = cmd->data_length >>
2084 				  ilog2(cmd->se_dev->dev_attrib.block_size);
2085 
2086 			cmd->pi_err = sbc_dif_verify(cmd, cmd->t_task_lba,
2087 						     sectors, 0, cmd->t_prot_sg,
2088 						     0);
2089 			if (cmd->pi_err)
2090 				return true;
2091 		}
2092 		break;
2093 	case TARGET_PROT_DIN_INSERT:
2094 		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2095 			break;
2096 
2097 		sbc_dif_generate(cmd);
2098 		break;
2099 	default:
2100 		break;
2101 	}
2102 
2103 	return false;
2104 }
2105 
2106 static void target_complete_ok_work(struct work_struct *work)
2107 {
2108 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2109 	int ret;
2110 
2111 	/*
2112 	 * Check if we need to move delayed/dormant tasks from cmds on the
2113 	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2114 	 * Attribute.
2115 	 */
2116 	transport_complete_task_attr(cmd);
2117 
2118 	/*
2119 	 * Check to schedule QUEUE_FULL work, or execute an existing
2120 	 * cmd->transport_qf_callback()
2121 	 */
2122 	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2123 		schedule_work(&cmd->se_dev->qf_work_queue);
2124 
2125 	/*
2126 	 * Check if we need to send a sense buffer from
2127 	 * the struct se_cmd in question.
2128 	 */
2129 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2130 		WARN_ON(!cmd->scsi_status);
2131 		ret = transport_send_check_condition_and_sense(
2132 					cmd, 0, 1);
2133 		if (ret)
2134 			goto queue_full;
2135 
2136 		transport_lun_remove_cmd(cmd);
2137 		transport_cmd_check_stop_to_fabric(cmd);
2138 		return;
2139 	}
2140 	/*
2141 	 * Check for a callback, used by amongst other things
2142 	 * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2143 	 */
2144 	if (cmd->transport_complete_callback) {
2145 		sense_reason_t rc;
2146 		bool caw = (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE);
2147 		bool zero_dl = !(cmd->data_length);
2148 		int post_ret = 0;
2149 
2150 		rc = cmd->transport_complete_callback(cmd, true, &post_ret);
2151 		if (!rc && !post_ret) {
2152 			if (caw && zero_dl)
2153 				goto queue_rsp;
2154 
2155 			return;
2156 		} else if (rc) {
2157 			ret = transport_send_check_condition_and_sense(cmd,
2158 						rc, 0);
2159 			if (ret)
2160 				goto queue_full;
2161 
2162 			transport_lun_remove_cmd(cmd);
2163 			transport_cmd_check_stop_to_fabric(cmd);
2164 			return;
2165 		}
2166 	}
2167 
2168 queue_rsp:
2169 	switch (cmd->data_direction) {
2170 	case DMA_FROM_DEVICE:
2171 		if (cmd->scsi_status)
2172 			goto queue_status;
2173 
2174 		atomic_long_add(cmd->data_length,
2175 				&cmd->se_lun->lun_stats.tx_data_octets);
2176 		/*
2177 		 * Perform READ_STRIP of PI using software emulation when
2178 		 * backend had PI enabled, if the transport will not be
2179 		 * performing hardware READ_STRIP offload.
2180 		 */
2181 		if (target_read_prot_action(cmd)) {
2182 			ret = transport_send_check_condition_and_sense(cmd,
2183 						cmd->pi_err, 0);
2184 			if (ret)
2185 				goto queue_full;
2186 
2187 			transport_lun_remove_cmd(cmd);
2188 			transport_cmd_check_stop_to_fabric(cmd);
2189 			return;
2190 		}
2191 
2192 		trace_target_cmd_complete(cmd);
2193 		ret = cmd->se_tfo->queue_data_in(cmd);
2194 		if (ret)
2195 			goto queue_full;
2196 		break;
2197 	case DMA_TO_DEVICE:
2198 		atomic_long_add(cmd->data_length,
2199 				&cmd->se_lun->lun_stats.rx_data_octets);
2200 		/*
2201 		 * Check if we need to send READ payload for BIDI-COMMAND
2202 		 */
2203 		if (cmd->se_cmd_flags & SCF_BIDI) {
2204 			atomic_long_add(cmd->data_length,
2205 					&cmd->se_lun->lun_stats.tx_data_octets);
2206 			ret = cmd->se_tfo->queue_data_in(cmd);
2207 			if (ret)
2208 				goto queue_full;
2209 			break;
2210 		}
2211 		/* Fall through for DMA_TO_DEVICE */
2212 	case DMA_NONE:
2213 queue_status:
2214 		trace_target_cmd_complete(cmd);
2215 		ret = cmd->se_tfo->queue_status(cmd);
2216 		if (ret)
2217 			goto queue_full;
2218 		break;
2219 	default:
2220 		break;
2221 	}
2222 
2223 	transport_lun_remove_cmd(cmd);
2224 	transport_cmd_check_stop_to_fabric(cmd);
2225 	return;
2226 
2227 queue_full:
2228 	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2229 		" data_direction: %d\n", cmd, cmd->data_direction);
2230 
2231 	transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
2232 }
2233 
2234 void target_free_sgl(struct scatterlist *sgl, int nents)
2235 {
2236 	struct scatterlist *sg;
2237 	int count;
2238 
2239 	for_each_sg(sgl, sg, nents, count)
2240 		__free_page(sg_page(sg));
2241 
2242 	kfree(sgl);
2243 }
2244 EXPORT_SYMBOL(target_free_sgl);
2245 
2246 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2247 {
2248 	/*
2249 	 * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2250 	 * emulation, and free + reset pointers if necessary..
2251 	 */
2252 	if (!cmd->t_data_sg_orig)
2253 		return;
2254 
2255 	kfree(cmd->t_data_sg);
2256 	cmd->t_data_sg = cmd->t_data_sg_orig;
2257 	cmd->t_data_sg_orig = NULL;
2258 	cmd->t_data_nents = cmd->t_data_nents_orig;
2259 	cmd->t_data_nents_orig = 0;
2260 }
2261 
2262 static inline void transport_free_pages(struct se_cmd *cmd)
2263 {
2264 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2265 		target_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2266 		cmd->t_prot_sg = NULL;
2267 		cmd->t_prot_nents = 0;
2268 	}
2269 
2270 	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2271 		/*
2272 		 * Release special case READ buffer payload required for
2273 		 * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2274 		 */
2275 		if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2276 			target_free_sgl(cmd->t_bidi_data_sg,
2277 					   cmd->t_bidi_data_nents);
2278 			cmd->t_bidi_data_sg = NULL;
2279 			cmd->t_bidi_data_nents = 0;
2280 		}
2281 		transport_reset_sgl_orig(cmd);
2282 		return;
2283 	}
2284 	transport_reset_sgl_orig(cmd);
2285 
2286 	target_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2287 	cmd->t_data_sg = NULL;
2288 	cmd->t_data_nents = 0;
2289 
2290 	target_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2291 	cmd->t_bidi_data_sg = NULL;
2292 	cmd->t_bidi_data_nents = 0;
2293 }
2294 
2295 /**
2296  * transport_put_cmd - release a reference to a command
2297  * @cmd:       command to release
2298  *
2299  * This routine releases our reference to the command and frees it if possible.
2300  */
2301 static int transport_put_cmd(struct se_cmd *cmd)
2302 {
2303 	BUG_ON(!cmd->se_tfo);
2304 	/*
2305 	 * If this cmd has been setup with target_get_sess_cmd(), drop
2306 	 * the kref and call ->release_cmd() in kref callback.
2307 	 */
2308 	return target_put_sess_cmd(cmd);
2309 }
2310 
2311 void *transport_kmap_data_sg(struct se_cmd *cmd)
2312 {
2313 	struct scatterlist *sg = cmd->t_data_sg;
2314 	struct page **pages;
2315 	int i;
2316 
2317 	/*
2318 	 * We need to take into account a possible offset here for fabrics like
2319 	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2320 	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2321 	 */
2322 	if (!cmd->t_data_nents)
2323 		return NULL;
2324 
2325 	BUG_ON(!sg);
2326 	if (cmd->t_data_nents == 1)
2327 		return kmap(sg_page(sg)) + sg->offset;
2328 
2329 	/* >1 page. use vmap */
2330 	pages = kmalloc_array(cmd->t_data_nents, sizeof(*pages), GFP_KERNEL);
2331 	if (!pages)
2332 		return NULL;
2333 
2334 	/* convert sg[] to pages[] */
2335 	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2336 		pages[i] = sg_page(sg);
2337 	}
2338 
2339 	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2340 	kfree(pages);
2341 	if (!cmd->t_data_vmap)
2342 		return NULL;
2343 
2344 	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2345 }
2346 EXPORT_SYMBOL(transport_kmap_data_sg);
2347 
2348 void transport_kunmap_data_sg(struct se_cmd *cmd)
2349 {
2350 	if (!cmd->t_data_nents) {
2351 		return;
2352 	} else if (cmd->t_data_nents == 1) {
2353 		kunmap(sg_page(cmd->t_data_sg));
2354 		return;
2355 	}
2356 
2357 	vunmap(cmd->t_data_vmap);
2358 	cmd->t_data_vmap = NULL;
2359 }
2360 EXPORT_SYMBOL(transport_kunmap_data_sg);
2361 
2362 int
2363 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2364 		 bool zero_page, bool chainable)
2365 {
2366 	struct scatterlist *sg;
2367 	struct page *page;
2368 	gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2369 	unsigned int nalloc, nent;
2370 	int i = 0;
2371 
2372 	nalloc = nent = DIV_ROUND_UP(length, PAGE_SIZE);
2373 	if (chainable)
2374 		nalloc++;
2375 	sg = kmalloc_array(nalloc, sizeof(struct scatterlist), GFP_KERNEL);
2376 	if (!sg)
2377 		return -ENOMEM;
2378 
2379 	sg_init_table(sg, nalloc);
2380 
2381 	while (length) {
2382 		u32 page_len = min_t(u32, length, PAGE_SIZE);
2383 		page = alloc_page(GFP_KERNEL | zero_flag);
2384 		if (!page)
2385 			goto out;
2386 
2387 		sg_set_page(&sg[i], page, page_len, 0);
2388 		length -= page_len;
2389 		i++;
2390 	}
2391 	*sgl = sg;
2392 	*nents = nent;
2393 	return 0;
2394 
2395 out:
2396 	while (i > 0) {
2397 		i--;
2398 		__free_page(sg_page(&sg[i]));
2399 	}
2400 	kfree(sg);
2401 	return -ENOMEM;
2402 }
2403 EXPORT_SYMBOL(target_alloc_sgl);
2404 
2405 /*
2406  * Allocate any required resources to execute the command.  For writes we
2407  * might not have the payload yet, so notify the fabric via a call to
2408  * ->write_pending instead. Otherwise place it on the execution queue.
2409  */
2410 sense_reason_t
2411 transport_generic_new_cmd(struct se_cmd *cmd)
2412 {
2413 	unsigned long flags;
2414 	int ret = 0;
2415 	bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2416 
2417 	if (cmd->prot_op != TARGET_PROT_NORMAL &&
2418 	    !(cmd->se_cmd_flags & SCF_PASSTHROUGH_PROT_SG_TO_MEM_NOALLOC)) {
2419 		ret = target_alloc_sgl(&cmd->t_prot_sg, &cmd->t_prot_nents,
2420 				       cmd->prot_length, true, false);
2421 		if (ret < 0)
2422 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2423 	}
2424 
2425 	/*
2426 	 * Determine is the TCM fabric module has already allocated physical
2427 	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2428 	 * beforehand.
2429 	 */
2430 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2431 	    cmd->data_length) {
2432 
2433 		if ((cmd->se_cmd_flags & SCF_BIDI) ||
2434 		    (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2435 			u32 bidi_length;
2436 
2437 			if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2438 				bidi_length = cmd->t_task_nolb *
2439 					      cmd->se_dev->dev_attrib.block_size;
2440 			else
2441 				bidi_length = cmd->data_length;
2442 
2443 			ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2444 					       &cmd->t_bidi_data_nents,
2445 					       bidi_length, zero_flag, false);
2446 			if (ret < 0)
2447 				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2448 		}
2449 
2450 		ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2451 				       cmd->data_length, zero_flag, false);
2452 		if (ret < 0)
2453 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2454 	} else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2455 		    cmd->data_length) {
2456 		/*
2457 		 * Special case for COMPARE_AND_WRITE with fabrics
2458 		 * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2459 		 */
2460 		u32 caw_length = cmd->t_task_nolb *
2461 				 cmd->se_dev->dev_attrib.block_size;
2462 
2463 		ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2464 				       &cmd->t_bidi_data_nents,
2465 				       caw_length, zero_flag, false);
2466 		if (ret < 0)
2467 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2468 	}
2469 	/*
2470 	 * If this command is not a write we can execute it right here,
2471 	 * for write buffers we need to notify the fabric driver first
2472 	 * and let it call back once the write buffers are ready.
2473 	 */
2474 	target_add_to_state_list(cmd);
2475 	if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2476 		target_execute_cmd(cmd);
2477 		return 0;
2478 	}
2479 
2480 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2481 	cmd->t_state = TRANSPORT_WRITE_PENDING;
2482 	/*
2483 	 * Determine if frontend context caller is requesting the stopping of
2484 	 * this command for frontend exceptions.
2485 	 */
2486 	if (cmd->transport_state & CMD_T_STOP) {
2487 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08llx\n",
2488 			 __func__, __LINE__, cmd->tag);
2489 
2490 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2491 
2492 		complete_all(&cmd->t_transport_stop_comp);
2493 		return 0;
2494 	}
2495 	cmd->transport_state &= ~CMD_T_ACTIVE;
2496 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2497 
2498 	ret = cmd->se_tfo->write_pending(cmd);
2499 	if (ret)
2500 		goto queue_full;
2501 
2502 	return 0;
2503 
2504 queue_full:
2505 	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2506 	transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2507 	return 0;
2508 }
2509 EXPORT_SYMBOL(transport_generic_new_cmd);
2510 
2511 static void transport_write_pending_qf(struct se_cmd *cmd)
2512 {
2513 	int ret;
2514 
2515 	ret = cmd->se_tfo->write_pending(cmd);
2516 	if (ret) {
2517 		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2518 			 cmd);
2519 		transport_handle_queue_full(cmd, cmd->se_dev, ret, true);
2520 	}
2521 }
2522 
2523 static bool
2524 __transport_wait_for_tasks(struct se_cmd *, bool, bool *, bool *,
2525 			   unsigned long *flags);
2526 
2527 static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas)
2528 {
2529 	unsigned long flags;
2530 
2531 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2532 	__transport_wait_for_tasks(cmd, true, aborted, tas, &flags);
2533 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2534 }
2535 
2536 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2537 {
2538 	int ret = 0;
2539 	bool aborted = false, tas = false;
2540 
2541 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2542 		if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2543 			target_wait_free_cmd(cmd, &aborted, &tas);
2544 
2545 		if (!aborted || tas)
2546 			ret = transport_put_cmd(cmd);
2547 	} else {
2548 		if (wait_for_tasks)
2549 			target_wait_free_cmd(cmd, &aborted, &tas);
2550 		/*
2551 		 * Handle WRITE failure case where transport_generic_new_cmd()
2552 		 * has already added se_cmd to state_list, but fabric has
2553 		 * failed command before I/O submission.
2554 		 */
2555 		if (cmd->state_active)
2556 			target_remove_from_state_list(cmd);
2557 
2558 		if (cmd->se_lun)
2559 			transport_lun_remove_cmd(cmd);
2560 
2561 		if (!aborted || tas)
2562 			ret = transport_put_cmd(cmd);
2563 	}
2564 	/*
2565 	 * If the task has been internally aborted due to TMR ABORT_TASK
2566 	 * or LUN_RESET, target_core_tmr.c is responsible for performing
2567 	 * the remaining calls to target_put_sess_cmd(), and not the
2568 	 * callers of this function.
2569 	 */
2570 	if (aborted) {
2571 		pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);
2572 		wait_for_completion(&cmd->cmd_wait_comp);
2573 		cmd->se_tfo->release_cmd(cmd);
2574 		ret = 1;
2575 	}
2576 	return ret;
2577 }
2578 EXPORT_SYMBOL(transport_generic_free_cmd);
2579 
2580 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2581  * @se_cmd:	command descriptor to add
2582  * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
2583  */
2584 int target_get_sess_cmd(struct se_cmd *se_cmd, bool ack_kref)
2585 {
2586 	struct se_session *se_sess = se_cmd->se_sess;
2587 	unsigned long flags;
2588 	int ret = 0;
2589 
2590 	/*
2591 	 * Add a second kref if the fabric caller is expecting to handle
2592 	 * fabric acknowledgement that requires two target_put_sess_cmd()
2593 	 * invocations before se_cmd descriptor release.
2594 	 */
2595 	if (ack_kref) {
2596 		if (!kref_get_unless_zero(&se_cmd->cmd_kref))
2597 			return -EINVAL;
2598 
2599 		se_cmd->se_cmd_flags |= SCF_ACK_KREF;
2600 	}
2601 
2602 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2603 	if (se_sess->sess_tearing_down) {
2604 		ret = -ESHUTDOWN;
2605 		goto out;
2606 	}
2607 	list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2608 out:
2609 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2610 
2611 	if (ret && ack_kref)
2612 		target_put_sess_cmd(se_cmd);
2613 
2614 	return ret;
2615 }
2616 EXPORT_SYMBOL(target_get_sess_cmd);
2617 
2618 static void target_free_cmd_mem(struct se_cmd *cmd)
2619 {
2620 	transport_free_pages(cmd);
2621 
2622 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2623 		core_tmr_release_req(cmd->se_tmr_req);
2624 	if (cmd->t_task_cdb != cmd->__t_task_cdb)
2625 		kfree(cmd->t_task_cdb);
2626 }
2627 
2628 static void target_release_cmd_kref(struct kref *kref)
2629 {
2630 	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2631 	struct se_session *se_sess = se_cmd->se_sess;
2632 	unsigned long flags;
2633 	bool fabric_stop;
2634 
2635 	if (se_sess) {
2636 		spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2637 
2638 		spin_lock(&se_cmd->t_state_lock);
2639 		fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP) &&
2640 			      (se_cmd->transport_state & CMD_T_ABORTED);
2641 		spin_unlock(&se_cmd->t_state_lock);
2642 
2643 		if (se_cmd->cmd_wait_set || fabric_stop) {
2644 			list_del_init(&se_cmd->se_cmd_list);
2645 			spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2646 			target_free_cmd_mem(se_cmd);
2647 			complete(&se_cmd->cmd_wait_comp);
2648 			return;
2649 		}
2650 		list_del_init(&se_cmd->se_cmd_list);
2651 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2652 	}
2653 
2654 	target_free_cmd_mem(se_cmd);
2655 	se_cmd->se_tfo->release_cmd(se_cmd);
2656 }
2657 
2658 /**
2659  * target_put_sess_cmd - decrease the command reference count
2660  * @se_cmd:	command to drop a reference from
2661  *
2662  * Returns 1 if and only if this target_put_sess_cmd() call caused the
2663  * refcount to drop to zero. Returns zero otherwise.
2664  */
2665 int target_put_sess_cmd(struct se_cmd *se_cmd)
2666 {
2667 	return kref_put(&se_cmd->cmd_kref, target_release_cmd_kref);
2668 }
2669 EXPORT_SYMBOL(target_put_sess_cmd);
2670 
2671 /* target_sess_cmd_list_set_waiting - Flag all commands in
2672  *         sess_cmd_list to complete cmd_wait_comp.  Set
2673  *         sess_tearing_down so no more commands are queued.
2674  * @se_sess:	session to flag
2675  */
2676 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2677 {
2678 	struct se_cmd *se_cmd, *tmp_cmd;
2679 	unsigned long flags;
2680 	int rc;
2681 
2682 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2683 	if (se_sess->sess_tearing_down) {
2684 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2685 		return;
2686 	}
2687 	se_sess->sess_tearing_down = 1;
2688 	list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2689 
2690 	list_for_each_entry_safe(se_cmd, tmp_cmd,
2691 				 &se_sess->sess_wait_list, se_cmd_list) {
2692 		rc = kref_get_unless_zero(&se_cmd->cmd_kref);
2693 		if (rc) {
2694 			se_cmd->cmd_wait_set = 1;
2695 			spin_lock(&se_cmd->t_state_lock);
2696 			se_cmd->transport_state |= CMD_T_FABRIC_STOP;
2697 			spin_unlock(&se_cmd->t_state_lock);
2698 		} else
2699 			list_del_init(&se_cmd->se_cmd_list);
2700 	}
2701 
2702 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2703 }
2704 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2705 
2706 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2707  * @se_sess:    session to wait for active I/O
2708  */
2709 void target_wait_for_sess_cmds(struct se_session *se_sess)
2710 {
2711 	struct se_cmd *se_cmd, *tmp_cmd;
2712 	unsigned long flags;
2713 	bool tas;
2714 
2715 	list_for_each_entry_safe(se_cmd, tmp_cmd,
2716 				&se_sess->sess_wait_list, se_cmd_list) {
2717 		pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2718 			" %d\n", se_cmd, se_cmd->t_state,
2719 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2720 
2721 		spin_lock_irqsave(&se_cmd->t_state_lock, flags);
2722 		tas = (se_cmd->transport_state & CMD_T_TAS);
2723 		spin_unlock_irqrestore(&se_cmd->t_state_lock, flags);
2724 
2725 		if (!target_put_sess_cmd(se_cmd)) {
2726 			if (tas)
2727 				target_put_sess_cmd(se_cmd);
2728 		}
2729 
2730 		wait_for_completion(&se_cmd->cmd_wait_comp);
2731 		pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2732 			" fabric state: %d\n", se_cmd, se_cmd->t_state,
2733 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2734 
2735 		se_cmd->se_tfo->release_cmd(se_cmd);
2736 	}
2737 
2738 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2739 	WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2740 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2741 
2742 }
2743 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2744 
2745 static void target_lun_confirm(struct percpu_ref *ref)
2746 {
2747 	struct se_lun *lun = container_of(ref, struct se_lun, lun_ref);
2748 
2749 	complete(&lun->lun_ref_comp);
2750 }
2751 
2752 void transport_clear_lun_ref(struct se_lun *lun)
2753 {
2754 	/*
2755 	 * Mark the percpu-ref as DEAD, switch to atomic_t mode, drop
2756 	 * the initial reference and schedule confirm kill to be
2757 	 * executed after one full RCU grace period has completed.
2758 	 */
2759 	percpu_ref_kill_and_confirm(&lun->lun_ref, target_lun_confirm);
2760 	/*
2761 	 * The first completion waits for percpu_ref_switch_to_atomic_rcu()
2762 	 * to call target_lun_confirm after lun->lun_ref has been marked
2763 	 * as __PERCPU_REF_DEAD on all CPUs, and switches to atomic_t
2764 	 * mode so that percpu_ref_tryget_live() lookup of lun->lun_ref
2765 	 * fails for all new incoming I/O.
2766 	 */
2767 	wait_for_completion(&lun->lun_ref_comp);
2768 	/*
2769 	 * The second completion waits for percpu_ref_put_many() to
2770 	 * invoke ->release() after lun->lun_ref has switched to
2771 	 * atomic_t mode, and lun->lun_ref.count has reached zero.
2772 	 *
2773 	 * At this point all target-core lun->lun_ref references have
2774 	 * been dropped via transport_lun_remove_cmd(), and it's safe
2775 	 * to proceed with the remaining LUN shutdown.
2776 	 */
2777 	wait_for_completion(&lun->lun_shutdown_comp);
2778 }
2779 
2780 static bool
2781 __transport_wait_for_tasks(struct se_cmd *cmd, bool fabric_stop,
2782 			   bool *aborted, bool *tas, unsigned long *flags)
2783 	__releases(&cmd->t_state_lock)
2784 	__acquires(&cmd->t_state_lock)
2785 {
2786 
2787 	assert_spin_locked(&cmd->t_state_lock);
2788 	WARN_ON_ONCE(!irqs_disabled());
2789 
2790 	if (fabric_stop)
2791 		cmd->transport_state |= CMD_T_FABRIC_STOP;
2792 
2793 	if (cmd->transport_state & CMD_T_ABORTED)
2794 		*aborted = true;
2795 
2796 	if (cmd->transport_state & CMD_T_TAS)
2797 		*tas = true;
2798 
2799 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2800 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2801 		return false;
2802 
2803 	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2804 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2805 		return false;
2806 
2807 	if (!(cmd->transport_state & CMD_T_ACTIVE))
2808 		return false;
2809 
2810 	if (fabric_stop && *aborted)
2811 		return false;
2812 
2813 	cmd->transport_state |= CMD_T_STOP;
2814 
2815 	pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08llx i_state: %d,"
2816 		 " t_state: %d, CMD_T_STOP\n", cmd, cmd->tag,
2817 		 cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2818 
2819 	spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
2820 
2821 	wait_for_completion(&cmd->t_transport_stop_comp);
2822 
2823 	spin_lock_irqsave(&cmd->t_state_lock, *flags);
2824 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2825 
2826 	pr_debug("wait_for_tasks: Stopped wait_for_completion(&cmd->"
2827 		 "t_transport_stop_comp) for ITT: 0x%08llx\n", cmd->tag);
2828 
2829 	return true;
2830 }
2831 
2832 /**
2833  * transport_wait_for_tasks - set CMD_T_STOP and wait for t_transport_stop_comp
2834  * @cmd: command to wait on
2835  */
2836 bool transport_wait_for_tasks(struct se_cmd *cmd)
2837 {
2838 	unsigned long flags;
2839 	bool ret, aborted = false, tas = false;
2840 
2841 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2842 	ret = __transport_wait_for_tasks(cmd, false, &aborted, &tas, &flags);
2843 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2844 
2845 	return ret;
2846 }
2847 EXPORT_SYMBOL(transport_wait_for_tasks);
2848 
2849 struct sense_info {
2850 	u8 key;
2851 	u8 asc;
2852 	u8 ascq;
2853 	bool add_sector_info;
2854 };
2855 
2856 static const struct sense_info sense_info_table[] = {
2857 	[TCM_NO_SENSE] = {
2858 		.key = NOT_READY
2859 	},
2860 	[TCM_NON_EXISTENT_LUN] = {
2861 		.key = ILLEGAL_REQUEST,
2862 		.asc = 0x25 /* LOGICAL UNIT NOT SUPPORTED */
2863 	},
2864 	[TCM_UNSUPPORTED_SCSI_OPCODE] = {
2865 		.key = ILLEGAL_REQUEST,
2866 		.asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2867 	},
2868 	[TCM_SECTOR_COUNT_TOO_MANY] = {
2869 		.key = ILLEGAL_REQUEST,
2870 		.asc = 0x20, /* INVALID COMMAND OPERATION CODE */
2871 	},
2872 	[TCM_UNKNOWN_MODE_PAGE] = {
2873 		.key = ILLEGAL_REQUEST,
2874 		.asc = 0x24, /* INVALID FIELD IN CDB */
2875 	},
2876 	[TCM_CHECK_CONDITION_ABORT_CMD] = {
2877 		.key = ABORTED_COMMAND,
2878 		.asc = 0x29, /* BUS DEVICE RESET FUNCTION OCCURRED */
2879 		.ascq = 0x03,
2880 	},
2881 	[TCM_INCORRECT_AMOUNT_OF_DATA] = {
2882 		.key = ABORTED_COMMAND,
2883 		.asc = 0x0c, /* WRITE ERROR */
2884 		.ascq = 0x0d, /* NOT ENOUGH UNSOLICITED DATA */
2885 	},
2886 	[TCM_INVALID_CDB_FIELD] = {
2887 		.key = ILLEGAL_REQUEST,
2888 		.asc = 0x24, /* INVALID FIELD IN CDB */
2889 	},
2890 	[TCM_INVALID_PARAMETER_LIST] = {
2891 		.key = ILLEGAL_REQUEST,
2892 		.asc = 0x26, /* INVALID FIELD IN PARAMETER LIST */
2893 	},
2894 	[TCM_TOO_MANY_TARGET_DESCS] = {
2895 		.key = ILLEGAL_REQUEST,
2896 		.asc = 0x26,
2897 		.ascq = 0x06, /* TOO MANY TARGET DESCRIPTORS */
2898 	},
2899 	[TCM_UNSUPPORTED_TARGET_DESC_TYPE_CODE] = {
2900 		.key = ILLEGAL_REQUEST,
2901 		.asc = 0x26,
2902 		.ascq = 0x07, /* UNSUPPORTED TARGET DESCRIPTOR TYPE CODE */
2903 	},
2904 	[TCM_TOO_MANY_SEGMENT_DESCS] = {
2905 		.key = ILLEGAL_REQUEST,
2906 		.asc = 0x26,
2907 		.ascq = 0x08, /* TOO MANY SEGMENT DESCRIPTORS */
2908 	},
2909 	[TCM_UNSUPPORTED_SEGMENT_DESC_TYPE_CODE] = {
2910 		.key = ILLEGAL_REQUEST,
2911 		.asc = 0x26,
2912 		.ascq = 0x09, /* UNSUPPORTED SEGMENT DESCRIPTOR TYPE CODE */
2913 	},
2914 	[TCM_PARAMETER_LIST_LENGTH_ERROR] = {
2915 		.key = ILLEGAL_REQUEST,
2916 		.asc = 0x1a, /* PARAMETER LIST LENGTH ERROR */
2917 	},
2918 	[TCM_UNEXPECTED_UNSOLICITED_DATA] = {
2919 		.key = ILLEGAL_REQUEST,
2920 		.asc = 0x0c, /* WRITE ERROR */
2921 		.ascq = 0x0c, /* UNEXPECTED_UNSOLICITED_DATA */
2922 	},
2923 	[TCM_SERVICE_CRC_ERROR] = {
2924 		.key = ABORTED_COMMAND,
2925 		.asc = 0x47, /* PROTOCOL SERVICE CRC ERROR */
2926 		.ascq = 0x05, /* N/A */
2927 	},
2928 	[TCM_SNACK_REJECTED] = {
2929 		.key = ABORTED_COMMAND,
2930 		.asc = 0x11, /* READ ERROR */
2931 		.ascq = 0x13, /* FAILED RETRANSMISSION REQUEST */
2932 	},
2933 	[TCM_WRITE_PROTECTED] = {
2934 		.key = DATA_PROTECT,
2935 		.asc = 0x27, /* WRITE PROTECTED */
2936 	},
2937 	[TCM_ADDRESS_OUT_OF_RANGE] = {
2938 		.key = ILLEGAL_REQUEST,
2939 		.asc = 0x21, /* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2940 	},
2941 	[TCM_CHECK_CONDITION_UNIT_ATTENTION] = {
2942 		.key = UNIT_ATTENTION,
2943 	},
2944 	[TCM_CHECK_CONDITION_NOT_READY] = {
2945 		.key = NOT_READY,
2946 	},
2947 	[TCM_MISCOMPARE_VERIFY] = {
2948 		.key = MISCOMPARE,
2949 		.asc = 0x1d, /* MISCOMPARE DURING VERIFY OPERATION */
2950 		.ascq = 0x00,
2951 	},
2952 	[TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED] = {
2953 		.key = ABORTED_COMMAND,
2954 		.asc = 0x10,
2955 		.ascq = 0x01, /* LOGICAL BLOCK GUARD CHECK FAILED */
2956 		.add_sector_info = true,
2957 	},
2958 	[TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED] = {
2959 		.key = ABORTED_COMMAND,
2960 		.asc = 0x10,
2961 		.ascq = 0x02, /* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2962 		.add_sector_info = true,
2963 	},
2964 	[TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED] = {
2965 		.key = ABORTED_COMMAND,
2966 		.asc = 0x10,
2967 		.ascq = 0x03, /* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2968 		.add_sector_info = true,
2969 	},
2970 	[TCM_COPY_TARGET_DEVICE_NOT_REACHABLE] = {
2971 		.key = COPY_ABORTED,
2972 		.asc = 0x0d,
2973 		.ascq = 0x02, /* COPY TARGET DEVICE NOT REACHABLE */
2974 
2975 	},
2976 	[TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE] = {
2977 		/*
2978 		 * Returning ILLEGAL REQUEST would cause immediate IO errors on
2979 		 * Solaris initiators.  Returning NOT READY instead means the
2980 		 * operations will be retried a finite number of times and we
2981 		 * can survive intermittent errors.
2982 		 */
2983 		.key = NOT_READY,
2984 		.asc = 0x08, /* LOGICAL UNIT COMMUNICATION FAILURE */
2985 	},
2986 };
2987 
2988 static int translate_sense_reason(struct se_cmd *cmd, sense_reason_t reason)
2989 {
2990 	const struct sense_info *si;
2991 	u8 *buffer = cmd->sense_buffer;
2992 	int r = (__force int)reason;
2993 	u8 asc, ascq;
2994 	bool desc_format = target_sense_desc_format(cmd->se_dev);
2995 
2996 	if (r < ARRAY_SIZE(sense_info_table) && sense_info_table[r].key)
2997 		si = &sense_info_table[r];
2998 	else
2999 		si = &sense_info_table[(__force int)
3000 				       TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE];
3001 
3002 	if (reason == TCM_CHECK_CONDITION_UNIT_ATTENTION) {
3003 		core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
3004 		WARN_ON_ONCE(asc == 0);
3005 	} else if (si->asc == 0) {
3006 		WARN_ON_ONCE(cmd->scsi_asc == 0);
3007 		asc = cmd->scsi_asc;
3008 		ascq = cmd->scsi_ascq;
3009 	} else {
3010 		asc = si->asc;
3011 		ascq = si->ascq;
3012 	}
3013 
3014 	scsi_build_sense_buffer(desc_format, buffer, si->key, asc, ascq);
3015 	if (si->add_sector_info)
3016 		return scsi_set_sense_information(buffer,
3017 						  cmd->scsi_sense_length,
3018 						  cmd->bad_sector);
3019 
3020 	return 0;
3021 }
3022 
3023 int
3024 transport_send_check_condition_and_sense(struct se_cmd *cmd,
3025 		sense_reason_t reason, int from_transport)
3026 {
3027 	unsigned long flags;
3028 
3029 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3030 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
3031 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3032 		return 0;
3033 	}
3034 	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
3035 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3036 
3037 	if (!from_transport) {
3038 		int rc;
3039 
3040 		cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
3041 		cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
3042 		cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
3043 		rc = translate_sense_reason(cmd, reason);
3044 		if (rc)
3045 			return rc;
3046 	}
3047 
3048 	trace_target_cmd_complete(cmd);
3049 	return cmd->se_tfo->queue_status(cmd);
3050 }
3051 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
3052 
3053 static int __transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3054 	__releases(&cmd->t_state_lock)
3055 	__acquires(&cmd->t_state_lock)
3056 {
3057 	int ret;
3058 
3059 	assert_spin_locked(&cmd->t_state_lock);
3060 	WARN_ON_ONCE(!irqs_disabled());
3061 
3062 	if (!(cmd->transport_state & CMD_T_ABORTED))
3063 		return 0;
3064 	/*
3065 	 * If cmd has been aborted but either no status is to be sent or it has
3066 	 * already been sent, just return
3067 	 */
3068 	if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS)) {
3069 		if (send_status)
3070 			cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3071 		return 1;
3072 	}
3073 
3074 	pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB:"
3075 		" 0x%02x ITT: 0x%08llx\n", cmd->t_task_cdb[0], cmd->tag);
3076 
3077 	cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
3078 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3079 	trace_target_cmd_complete(cmd);
3080 
3081 	spin_unlock_irq(&cmd->t_state_lock);
3082 	ret = cmd->se_tfo->queue_status(cmd);
3083 	if (ret)
3084 		transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
3085 	spin_lock_irq(&cmd->t_state_lock);
3086 
3087 	return 1;
3088 }
3089 
3090 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
3091 {
3092 	int ret;
3093 
3094 	spin_lock_irq(&cmd->t_state_lock);
3095 	ret = __transport_check_aborted_status(cmd, send_status);
3096 	spin_unlock_irq(&cmd->t_state_lock);
3097 
3098 	return ret;
3099 }
3100 EXPORT_SYMBOL(transport_check_aborted_status);
3101 
3102 void transport_send_task_abort(struct se_cmd *cmd)
3103 {
3104 	unsigned long flags;
3105 	int ret;
3106 
3107 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3108 	if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
3109 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3110 		return;
3111 	}
3112 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3113 
3114 	/*
3115 	 * If there are still expected incoming fabric WRITEs, we wait
3116 	 * until until they have completed before sending a TASK_ABORTED
3117 	 * response.  This response with TASK_ABORTED status will be
3118 	 * queued back to fabric module by transport_check_aborted_status().
3119 	 */
3120 	if (cmd->data_direction == DMA_TO_DEVICE) {
3121 		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3122 			spin_lock_irqsave(&cmd->t_state_lock, flags);
3123 			if (cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS) {
3124 				spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3125 				goto send_abort;
3126 			}
3127 			cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3128 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3129 			return;
3130 		}
3131 	}
3132 send_abort:
3133 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3134 
3135 	transport_lun_remove_cmd(cmd);
3136 
3137 	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
3138 		 cmd->t_task_cdb[0], cmd->tag);
3139 
3140 	trace_target_cmd_complete(cmd);
3141 	ret = cmd->se_tfo->queue_status(cmd);
3142 	if (ret)
3143 		transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
3144 }
3145 
3146 static void target_tmr_work(struct work_struct *work)
3147 {
3148 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3149 	struct se_device *dev = cmd->se_dev;
3150 	struct se_tmr_req *tmr = cmd->se_tmr_req;
3151 	unsigned long flags;
3152 	int ret;
3153 
3154 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3155 	if (cmd->transport_state & CMD_T_ABORTED) {
3156 		tmr->response = TMR_FUNCTION_REJECTED;
3157 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3158 		goto check_stop;
3159 	}
3160 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3161 
3162 	switch (tmr->function) {
3163 	case TMR_ABORT_TASK:
3164 		core_tmr_abort_task(dev, tmr, cmd->se_sess);
3165 		break;
3166 	case TMR_ABORT_TASK_SET:
3167 	case TMR_CLEAR_ACA:
3168 	case TMR_CLEAR_TASK_SET:
3169 		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3170 		break;
3171 	case TMR_LUN_RESET:
3172 		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3173 		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3174 					 TMR_FUNCTION_REJECTED;
3175 		if (tmr->response == TMR_FUNCTION_COMPLETE) {
3176 			target_ua_allocate_lun(cmd->se_sess->se_node_acl,
3177 					       cmd->orig_fe_lun, 0x29,
3178 					       ASCQ_29H_BUS_DEVICE_RESET_FUNCTION_OCCURRED);
3179 		}
3180 		break;
3181 	case TMR_TARGET_WARM_RESET:
3182 		tmr->response = TMR_FUNCTION_REJECTED;
3183 		break;
3184 	case TMR_TARGET_COLD_RESET:
3185 		tmr->response = TMR_FUNCTION_REJECTED;
3186 		break;
3187 	default:
3188 		pr_err("Uknown TMR function: 0x%02x.\n",
3189 				tmr->function);
3190 		tmr->response = TMR_FUNCTION_REJECTED;
3191 		break;
3192 	}
3193 
3194 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3195 	if (cmd->transport_state & CMD_T_ABORTED) {
3196 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3197 		goto check_stop;
3198 	}
3199 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3200 
3201 	cmd->se_tfo->queue_tm_rsp(cmd);
3202 
3203 check_stop:
3204 	transport_cmd_check_stop_to_fabric(cmd);
3205 }
3206 
3207 int transport_generic_handle_tmr(
3208 	struct se_cmd *cmd)
3209 {
3210 	unsigned long flags;
3211 	bool aborted = false;
3212 
3213 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3214 	if (cmd->transport_state & CMD_T_ABORTED) {
3215 		aborted = true;
3216 	} else {
3217 		cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3218 		cmd->transport_state |= CMD_T_ACTIVE;
3219 	}
3220 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3221 
3222 	if (aborted) {
3223 		pr_warn_ratelimited("handle_tmr caught CMD_T_ABORTED TMR %d"
3224 			"ref_tag: %llu tag: %llu\n", cmd->se_tmr_req->function,
3225 			cmd->se_tmr_req->ref_task_tag, cmd->tag);
3226 		transport_cmd_check_stop_to_fabric(cmd);
3227 		return 0;
3228 	}
3229 
3230 	INIT_WORK(&cmd->work, target_tmr_work);
3231 	queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3232 	return 0;
3233 }
3234 EXPORT_SYMBOL(transport_generic_handle_tmr);
3235 
3236 bool
3237 target_check_wce(struct se_device *dev)
3238 {
3239 	bool wce = false;
3240 
3241 	if (dev->transport->get_write_cache)
3242 		wce = dev->transport->get_write_cache(dev);
3243 	else if (dev->dev_attrib.emulate_write_cache > 0)
3244 		wce = true;
3245 
3246 	return wce;
3247 }
3248 
3249 bool
3250 target_check_fua(struct se_device *dev)
3251 {
3252 	return target_check_wce(dev) && dev->dev_attrib.emulate_fua_write > 0;
3253 }
3254