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