xref: /linux/drivers/target/target_core_transport.c (revision 3e44c471a2dab210f7e9b1e5f7d4d54d52df59eb)
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 
43 #include <target/target_core_base.h>
44 #include <target/target_core_backend.h>
45 #include <target/target_core_fabric.h>
46 #include <target/target_core_configfs.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_tg_pt_gp_mem_cache;
64 struct kmem_cache *t10_alua_lba_map_cache;
65 struct kmem_cache *t10_alua_lba_map_mem_cache;
66 
67 static void transport_complete_task_attr(struct se_cmd *cmd);
68 static void transport_handle_queue_full(struct se_cmd *cmd,
69 		struct se_device *dev);
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_tg_pt_gp_mem_cache = kmem_cache_create(
123 			"t10_alua_tg_pt_gp_mem_cache",
124 			sizeof(struct t10_alua_tg_pt_gp_member),
125 			__alignof__(struct t10_alua_tg_pt_gp_member),
126 			0, NULL);
127 	if (!t10_alua_tg_pt_gp_mem_cache) {
128 		pr_err("kmem_cache_create() for t10_alua_tg_pt_gp_"
129 				"mem_t failed\n");
130 		goto out_free_tg_pt_gp_cache;
131 	}
132 	t10_alua_lba_map_cache = kmem_cache_create(
133 			"t10_alua_lba_map_cache",
134 			sizeof(struct t10_alua_lba_map),
135 			__alignof__(struct t10_alua_lba_map), 0, NULL);
136 	if (!t10_alua_lba_map_cache) {
137 		pr_err("kmem_cache_create() for t10_alua_lba_map_"
138 				"cache failed\n");
139 		goto out_free_tg_pt_gp_mem_cache;
140 	}
141 	t10_alua_lba_map_mem_cache = kmem_cache_create(
142 			"t10_alua_lba_map_mem_cache",
143 			sizeof(struct t10_alua_lba_map_member),
144 			__alignof__(struct t10_alua_lba_map_member), 0, NULL);
145 	if (!t10_alua_lba_map_mem_cache) {
146 		pr_err("kmem_cache_create() for t10_alua_lba_map_mem_"
147 				"cache failed\n");
148 		goto out_free_lba_map_cache;
149 	}
150 
151 	target_completion_wq = alloc_workqueue("target_completion",
152 					       WQ_MEM_RECLAIM, 0);
153 	if (!target_completion_wq)
154 		goto out_free_lba_map_mem_cache;
155 
156 	return 0;
157 
158 out_free_lba_map_mem_cache:
159 	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
160 out_free_lba_map_cache:
161 	kmem_cache_destroy(t10_alua_lba_map_cache);
162 out_free_tg_pt_gp_mem_cache:
163 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
164 out_free_tg_pt_gp_cache:
165 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
166 out_free_lu_gp_mem_cache:
167 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
168 out_free_lu_gp_cache:
169 	kmem_cache_destroy(t10_alua_lu_gp_cache);
170 out_free_pr_reg_cache:
171 	kmem_cache_destroy(t10_pr_reg_cache);
172 out_free_ua_cache:
173 	kmem_cache_destroy(se_ua_cache);
174 out_free_sess_cache:
175 	kmem_cache_destroy(se_sess_cache);
176 out:
177 	return -ENOMEM;
178 }
179 
180 void release_se_kmem_caches(void)
181 {
182 	destroy_workqueue(target_completion_wq);
183 	kmem_cache_destroy(se_sess_cache);
184 	kmem_cache_destroy(se_ua_cache);
185 	kmem_cache_destroy(t10_pr_reg_cache);
186 	kmem_cache_destroy(t10_alua_lu_gp_cache);
187 	kmem_cache_destroy(t10_alua_lu_gp_mem_cache);
188 	kmem_cache_destroy(t10_alua_tg_pt_gp_cache);
189 	kmem_cache_destroy(t10_alua_tg_pt_gp_mem_cache);
190 	kmem_cache_destroy(t10_alua_lba_map_cache);
191 	kmem_cache_destroy(t10_alua_lba_map_mem_cache);
192 }
193 
194 /* This code ensures unique mib indexes are handed out. */
195 static DEFINE_SPINLOCK(scsi_mib_index_lock);
196 static u32 scsi_mib_index[SCSI_INDEX_TYPE_MAX];
197 
198 /*
199  * Allocate a new row index for the entry type specified
200  */
201 u32 scsi_get_new_index(scsi_index_t type)
202 {
203 	u32 new_index;
204 
205 	BUG_ON((type < 0) || (type >= SCSI_INDEX_TYPE_MAX));
206 
207 	spin_lock(&scsi_mib_index_lock);
208 	new_index = ++scsi_mib_index[type];
209 	spin_unlock(&scsi_mib_index_lock);
210 
211 	return new_index;
212 }
213 
214 void transport_subsystem_check_init(void)
215 {
216 	int ret;
217 	static int sub_api_initialized;
218 
219 	if (sub_api_initialized)
220 		return;
221 
222 	ret = request_module("target_core_iblock");
223 	if (ret != 0)
224 		pr_err("Unable to load target_core_iblock\n");
225 
226 	ret = request_module("target_core_file");
227 	if (ret != 0)
228 		pr_err("Unable to load target_core_file\n");
229 
230 	ret = request_module("target_core_pscsi");
231 	if (ret != 0)
232 		pr_err("Unable to load target_core_pscsi\n");
233 
234 	ret = request_module("target_core_user");
235 	if (ret != 0)
236 		pr_err("Unable to load target_core_user\n");
237 
238 	sub_api_initialized = 1;
239 }
240 
241 struct se_session *transport_init_session(enum target_prot_op sup_prot_ops)
242 {
243 	struct se_session *se_sess;
244 
245 	se_sess = kmem_cache_zalloc(se_sess_cache, GFP_KERNEL);
246 	if (!se_sess) {
247 		pr_err("Unable to allocate struct se_session from"
248 				" se_sess_cache\n");
249 		return ERR_PTR(-ENOMEM);
250 	}
251 	INIT_LIST_HEAD(&se_sess->sess_list);
252 	INIT_LIST_HEAD(&se_sess->sess_acl_list);
253 	INIT_LIST_HEAD(&se_sess->sess_cmd_list);
254 	INIT_LIST_HEAD(&se_sess->sess_wait_list);
255 	spin_lock_init(&se_sess->sess_cmd_lock);
256 	kref_init(&se_sess->sess_kref);
257 	se_sess->sup_prot_ops = sup_prot_ops;
258 
259 	return se_sess;
260 }
261 EXPORT_SYMBOL(transport_init_session);
262 
263 int transport_alloc_session_tags(struct se_session *se_sess,
264 			         unsigned int tag_num, unsigned int tag_size)
265 {
266 	int rc;
267 
268 	se_sess->sess_cmd_map = kzalloc(tag_num * tag_size,
269 					GFP_KERNEL | __GFP_NOWARN | __GFP_REPEAT);
270 	if (!se_sess->sess_cmd_map) {
271 		se_sess->sess_cmd_map = vzalloc(tag_num * tag_size);
272 		if (!se_sess->sess_cmd_map) {
273 			pr_err("Unable to allocate se_sess->sess_cmd_map\n");
274 			return -ENOMEM;
275 		}
276 	}
277 
278 	rc = percpu_ida_init(&se_sess->sess_tag_pool, tag_num);
279 	if (rc < 0) {
280 		pr_err("Unable to init se_sess->sess_tag_pool,"
281 			" tag_num: %u\n", tag_num);
282 		if (is_vmalloc_addr(se_sess->sess_cmd_map))
283 			vfree(se_sess->sess_cmd_map);
284 		else
285 			kfree(se_sess->sess_cmd_map);
286 		se_sess->sess_cmd_map = NULL;
287 		return -ENOMEM;
288 	}
289 
290 	return 0;
291 }
292 EXPORT_SYMBOL(transport_alloc_session_tags);
293 
294 struct se_session *transport_init_session_tags(unsigned int tag_num,
295 					       unsigned int tag_size,
296 					       enum target_prot_op sup_prot_ops)
297 {
298 	struct se_session *se_sess;
299 	int rc;
300 
301 	se_sess = transport_init_session(sup_prot_ops);
302 	if (IS_ERR(se_sess))
303 		return se_sess;
304 
305 	rc = transport_alloc_session_tags(se_sess, tag_num, tag_size);
306 	if (rc < 0) {
307 		transport_free_session(se_sess);
308 		return ERR_PTR(-ENOMEM);
309 	}
310 
311 	return se_sess;
312 }
313 EXPORT_SYMBOL(transport_init_session_tags);
314 
315 /*
316  * Called with spin_lock_irqsave(&struct se_portal_group->session_lock called.
317  */
318 void __transport_register_session(
319 	struct se_portal_group *se_tpg,
320 	struct se_node_acl *se_nacl,
321 	struct se_session *se_sess,
322 	void *fabric_sess_ptr)
323 {
324 	const struct target_core_fabric_ops *tfo = se_tpg->se_tpg_tfo;
325 	unsigned char buf[PR_REG_ISID_LEN];
326 
327 	se_sess->se_tpg = se_tpg;
328 	se_sess->fabric_sess_ptr = fabric_sess_ptr;
329 	/*
330 	 * Used by struct se_node_acl's under ConfigFS to locate active se_session-t
331 	 *
332 	 * Only set for struct se_session's that will actually be moving I/O.
333 	 * eg: *NOT* discovery sessions.
334 	 */
335 	if (se_nacl) {
336 		/*
337 		 *
338 		 * Determine if fabric allows for T10-PI feature bits exposed to
339 		 * initiators for device backends with !dev->dev_attrib.pi_prot_type.
340 		 *
341 		 * If so, then always save prot_type on a per se_node_acl node
342 		 * basis and re-instate the previous sess_prot_type to avoid
343 		 * disabling PI from below any previously initiator side
344 		 * registered LUNs.
345 		 */
346 		if (se_nacl->saved_prot_type)
347 			se_sess->sess_prot_type = se_nacl->saved_prot_type;
348 		else if (tfo->tpg_check_prot_fabric_only)
349 			se_sess->sess_prot_type = se_nacl->saved_prot_type =
350 					tfo->tpg_check_prot_fabric_only(se_tpg);
351 		/*
352 		 * If the fabric module supports an ISID based TransportID,
353 		 * save this value in binary from the fabric I_T Nexus now.
354 		 */
355 		if (se_tpg->se_tpg_tfo->sess_get_initiator_sid != NULL) {
356 			memset(&buf[0], 0, PR_REG_ISID_LEN);
357 			se_tpg->se_tpg_tfo->sess_get_initiator_sid(se_sess,
358 					&buf[0], PR_REG_ISID_LEN);
359 			se_sess->sess_bin_isid = get_unaligned_be64(&buf[0]);
360 		}
361 		kref_get(&se_nacl->acl_kref);
362 
363 		spin_lock_irq(&se_nacl->nacl_sess_lock);
364 		/*
365 		 * The se_nacl->nacl_sess pointer will be set to the
366 		 * last active I_T Nexus for each struct se_node_acl.
367 		 */
368 		se_nacl->nacl_sess = se_sess;
369 
370 		list_add_tail(&se_sess->sess_acl_list,
371 			      &se_nacl->acl_sess_list);
372 		spin_unlock_irq(&se_nacl->nacl_sess_lock);
373 	}
374 	list_add_tail(&se_sess->sess_list, &se_tpg->tpg_sess_list);
375 
376 	pr_debug("TARGET_CORE[%s]: Registered fabric_sess_ptr: %p\n",
377 		se_tpg->se_tpg_tfo->get_fabric_name(), se_sess->fabric_sess_ptr);
378 }
379 EXPORT_SYMBOL(__transport_register_session);
380 
381 void transport_register_session(
382 	struct se_portal_group *se_tpg,
383 	struct se_node_acl *se_nacl,
384 	struct se_session *se_sess,
385 	void *fabric_sess_ptr)
386 {
387 	unsigned long flags;
388 
389 	spin_lock_irqsave(&se_tpg->session_lock, flags);
390 	__transport_register_session(se_tpg, se_nacl, se_sess, fabric_sess_ptr);
391 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
392 }
393 EXPORT_SYMBOL(transport_register_session);
394 
395 static void target_release_session(struct kref *kref)
396 {
397 	struct se_session *se_sess = container_of(kref,
398 			struct se_session, sess_kref);
399 	struct se_portal_group *se_tpg = se_sess->se_tpg;
400 
401 	se_tpg->se_tpg_tfo->close_session(se_sess);
402 }
403 
404 void target_get_session(struct se_session *se_sess)
405 {
406 	kref_get(&se_sess->sess_kref);
407 }
408 EXPORT_SYMBOL(target_get_session);
409 
410 void target_put_session(struct se_session *se_sess)
411 {
412 	struct se_portal_group *tpg = se_sess->se_tpg;
413 
414 	if (tpg->se_tpg_tfo->put_session != NULL) {
415 		tpg->se_tpg_tfo->put_session(se_sess);
416 		return;
417 	}
418 	kref_put(&se_sess->sess_kref, target_release_session);
419 }
420 EXPORT_SYMBOL(target_put_session);
421 
422 ssize_t target_show_dynamic_sessions(struct se_portal_group *se_tpg, char *page)
423 {
424 	struct se_session *se_sess;
425 	ssize_t len = 0;
426 
427 	spin_lock_bh(&se_tpg->session_lock);
428 	list_for_each_entry(se_sess, &se_tpg->tpg_sess_list, sess_list) {
429 		if (!se_sess->se_node_acl)
430 			continue;
431 		if (!se_sess->se_node_acl->dynamic_node_acl)
432 			continue;
433 		if (strlen(se_sess->se_node_acl->initiatorname) + 1 + len > PAGE_SIZE)
434 			break;
435 
436 		len += snprintf(page + len, PAGE_SIZE - len, "%s\n",
437 				se_sess->se_node_acl->initiatorname);
438 		len += 1; /* Include NULL terminator */
439 	}
440 	spin_unlock_bh(&se_tpg->session_lock);
441 
442 	return len;
443 }
444 EXPORT_SYMBOL(target_show_dynamic_sessions);
445 
446 static void target_complete_nacl(struct kref *kref)
447 {
448 	struct se_node_acl *nacl = container_of(kref,
449 				struct se_node_acl, acl_kref);
450 
451 	complete(&nacl->acl_free_comp);
452 }
453 
454 void target_put_nacl(struct se_node_acl *nacl)
455 {
456 	kref_put(&nacl->acl_kref, target_complete_nacl);
457 }
458 
459 void transport_deregister_session_configfs(struct se_session *se_sess)
460 {
461 	struct se_node_acl *se_nacl;
462 	unsigned long flags;
463 	/*
464 	 * Used by struct se_node_acl's under ConfigFS to locate active struct se_session
465 	 */
466 	se_nacl = se_sess->se_node_acl;
467 	if (se_nacl) {
468 		spin_lock_irqsave(&se_nacl->nacl_sess_lock, flags);
469 		if (se_nacl->acl_stop == 0)
470 			list_del(&se_sess->sess_acl_list);
471 		/*
472 		 * If the session list is empty, then clear the pointer.
473 		 * Otherwise, set the struct se_session pointer from the tail
474 		 * element of the per struct se_node_acl active session list.
475 		 */
476 		if (list_empty(&se_nacl->acl_sess_list))
477 			se_nacl->nacl_sess = NULL;
478 		else {
479 			se_nacl->nacl_sess = container_of(
480 					se_nacl->acl_sess_list.prev,
481 					struct se_session, sess_acl_list);
482 		}
483 		spin_unlock_irqrestore(&se_nacl->nacl_sess_lock, flags);
484 	}
485 }
486 EXPORT_SYMBOL(transport_deregister_session_configfs);
487 
488 void transport_free_session(struct se_session *se_sess)
489 {
490 	if (se_sess->sess_cmd_map) {
491 		percpu_ida_destroy(&se_sess->sess_tag_pool);
492 		if (is_vmalloc_addr(se_sess->sess_cmd_map))
493 			vfree(se_sess->sess_cmd_map);
494 		else
495 			kfree(se_sess->sess_cmd_map);
496 	}
497 	kmem_cache_free(se_sess_cache, se_sess);
498 }
499 EXPORT_SYMBOL(transport_free_session);
500 
501 void transport_deregister_session(struct se_session *se_sess)
502 {
503 	struct se_portal_group *se_tpg = se_sess->se_tpg;
504 	const struct target_core_fabric_ops *se_tfo;
505 	struct se_node_acl *se_nacl;
506 	unsigned long flags;
507 	bool comp_nacl = true;
508 
509 	if (!se_tpg) {
510 		transport_free_session(se_sess);
511 		return;
512 	}
513 	se_tfo = se_tpg->se_tpg_tfo;
514 
515 	spin_lock_irqsave(&se_tpg->session_lock, flags);
516 	list_del(&se_sess->sess_list);
517 	se_sess->se_tpg = NULL;
518 	se_sess->fabric_sess_ptr = NULL;
519 	spin_unlock_irqrestore(&se_tpg->session_lock, flags);
520 
521 	/*
522 	 * Determine if we need to do extra work for this initiator node's
523 	 * struct se_node_acl if it had been previously dynamically generated.
524 	 */
525 	se_nacl = se_sess->se_node_acl;
526 
527 	spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
528 	if (se_nacl && se_nacl->dynamic_node_acl) {
529 		if (!se_tfo->tpg_check_demo_mode_cache(se_tpg)) {
530 			list_del(&se_nacl->acl_list);
531 			se_tpg->num_node_acls--;
532 			spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
533 			core_tpg_wait_for_nacl_pr_ref(se_nacl);
534 			core_free_device_list_for_node(se_nacl, se_tpg);
535 			se_tfo->tpg_release_fabric_acl(se_tpg, se_nacl);
536 
537 			comp_nacl = false;
538 			spin_lock_irqsave(&se_tpg->acl_node_lock, flags);
539 		}
540 	}
541 	spin_unlock_irqrestore(&se_tpg->acl_node_lock, flags);
542 
543 	pr_debug("TARGET_CORE[%s]: Deregistered fabric_sess\n",
544 		se_tpg->se_tpg_tfo->get_fabric_name());
545 	/*
546 	 * If last kref is dropping now for an explicit NodeACL, awake sleeping
547 	 * ->acl_free_comp caller to wakeup configfs se_node_acl->acl_group
548 	 * removal context.
549 	 */
550 	if (se_nacl && comp_nacl)
551 		target_put_nacl(se_nacl);
552 
553 	transport_free_session(se_sess);
554 }
555 EXPORT_SYMBOL(transport_deregister_session);
556 
557 /*
558  * Called with cmd->t_state_lock held.
559  */
560 static void target_remove_from_state_list(struct se_cmd *cmd)
561 {
562 	struct se_device *dev = cmd->se_dev;
563 	unsigned long flags;
564 
565 	if (!dev)
566 		return;
567 
568 	if (cmd->transport_state & CMD_T_BUSY)
569 		return;
570 
571 	spin_lock_irqsave(&dev->execute_task_lock, flags);
572 	if (cmd->state_active) {
573 		list_del(&cmd->state_list);
574 		cmd->state_active = false;
575 	}
576 	spin_unlock_irqrestore(&dev->execute_task_lock, flags);
577 }
578 
579 static int transport_cmd_check_stop(struct se_cmd *cmd, bool remove_from_lists,
580 				    bool write_pending)
581 {
582 	unsigned long flags;
583 
584 	spin_lock_irqsave(&cmd->t_state_lock, flags);
585 	if (write_pending)
586 		cmd->t_state = TRANSPORT_WRITE_PENDING;
587 
588 	if (remove_from_lists) {
589 		target_remove_from_state_list(cmd);
590 
591 		/*
592 		 * Clear struct se_cmd->se_lun before the handoff to FE.
593 		 */
594 		cmd->se_lun = NULL;
595 	}
596 
597 	/*
598 	 * Determine if frontend context caller is requesting the stopping of
599 	 * this command for frontend exceptions.
600 	 */
601 	if (cmd->transport_state & CMD_T_STOP) {
602 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
603 			__func__, __LINE__,
604 			cmd->se_tfo->get_task_tag(cmd));
605 
606 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
607 
608 		complete_all(&cmd->t_transport_stop_comp);
609 		return 1;
610 	}
611 
612 	cmd->transport_state &= ~CMD_T_ACTIVE;
613 	if (remove_from_lists) {
614 		/*
615 		 * Some fabric modules like tcm_loop can release
616 		 * their internally allocated I/O reference now and
617 		 * struct se_cmd now.
618 		 *
619 		 * Fabric modules are expected to return '1' here if the
620 		 * se_cmd being passed is released at this point,
621 		 * or zero if not being released.
622 		 */
623 		if (cmd->se_tfo->check_stop_free != NULL) {
624 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
625 			return cmd->se_tfo->check_stop_free(cmd);
626 		}
627 	}
628 
629 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
630 	return 0;
631 }
632 
633 static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
634 {
635 	return transport_cmd_check_stop(cmd, true, false);
636 }
637 
638 static void transport_lun_remove_cmd(struct se_cmd *cmd)
639 {
640 	struct se_lun *lun = cmd->se_lun;
641 
642 	if (!lun)
643 		return;
644 
645 	if (cmpxchg(&cmd->lun_ref_active, true, false))
646 		percpu_ref_put(&lun->lun_ref);
647 }
648 
649 void transport_cmd_finish_abort(struct se_cmd *cmd, int remove)
650 {
651 	if (cmd->se_cmd_flags & SCF_SE_LUN_CMD)
652 		transport_lun_remove_cmd(cmd);
653 	/*
654 	 * Allow the fabric driver to unmap any resources before
655 	 * releasing the descriptor via TFO->release_cmd()
656 	 */
657 	if (remove)
658 		cmd->se_tfo->aborted_task(cmd);
659 
660 	if (transport_cmd_check_stop_to_fabric(cmd))
661 		return;
662 	if (remove)
663 		transport_put_cmd(cmd);
664 }
665 
666 static void target_complete_failure_work(struct work_struct *work)
667 {
668 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
669 
670 	transport_generic_request_failure(cmd,
671 			TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE);
672 }
673 
674 /*
675  * Used when asking transport to copy Sense Data from the underlying
676  * Linux/SCSI struct scsi_cmnd
677  */
678 static unsigned char *transport_get_sense_buffer(struct se_cmd *cmd)
679 {
680 	struct se_device *dev = cmd->se_dev;
681 
682 	WARN_ON(!cmd->se_lun);
683 
684 	if (!dev)
685 		return NULL;
686 
687 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION)
688 		return NULL;
689 
690 	cmd->scsi_sense_length = TRANSPORT_SENSE_BUFFER;
691 
692 	pr_debug("HBA_[%u]_PLUG[%s]: Requesting sense for SAM STATUS: 0x%02x\n",
693 		dev->se_hba->hba_id, dev->transport->name, cmd->scsi_status);
694 	return cmd->sense_buffer;
695 }
696 
697 void target_complete_cmd(struct se_cmd *cmd, u8 scsi_status)
698 {
699 	struct se_device *dev = cmd->se_dev;
700 	int success = scsi_status == GOOD;
701 	unsigned long flags;
702 
703 	cmd->scsi_status = scsi_status;
704 
705 
706 	spin_lock_irqsave(&cmd->t_state_lock, flags);
707 	cmd->transport_state &= ~CMD_T_BUSY;
708 
709 	if (dev && dev->transport->transport_complete) {
710 		dev->transport->transport_complete(cmd,
711 				cmd->t_data_sg,
712 				transport_get_sense_buffer(cmd));
713 		if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE)
714 			success = 1;
715 	}
716 
717 	/*
718 	 * See if we are waiting to complete for an exception condition.
719 	 */
720 	if (cmd->transport_state & CMD_T_REQUEST_STOP) {
721 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
722 		complete(&cmd->task_stop_comp);
723 		return;
724 	}
725 
726 	/*
727 	 * Check for case where an explicit ABORT_TASK has been received
728 	 * and transport_wait_for_tasks() will be waiting for completion..
729 	 */
730 	if (cmd->transport_state & CMD_T_ABORTED &&
731 	    cmd->transport_state & CMD_T_STOP) {
732 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
733 		complete_all(&cmd->t_transport_stop_comp);
734 		return;
735 	} else if (!success) {
736 		INIT_WORK(&cmd->work, target_complete_failure_work);
737 	} else {
738 		INIT_WORK(&cmd->work, target_complete_ok_work);
739 	}
740 
741 	cmd->t_state = TRANSPORT_COMPLETE;
742 	cmd->transport_state |= (CMD_T_COMPLETE | CMD_T_ACTIVE);
743 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
744 
745 	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 			transport_complete_qf(cmd);
810 	}
811 }
812 
813 unsigned char *transport_dump_cmd_direction(struct se_cmd *cmd)
814 {
815 	switch (cmd->data_direction) {
816 	case DMA_NONE:
817 		return "NONE";
818 	case DMA_FROM_DEVICE:
819 		return "READ";
820 	case DMA_TO_DEVICE:
821 		return "WRITE";
822 	case DMA_BIDIRECTIONAL:
823 		return "BIDI";
824 	default:
825 		break;
826 	}
827 
828 	return "UNKNOWN";
829 }
830 
831 void transport_dump_dev_state(
832 	struct se_device *dev,
833 	char *b,
834 	int *bl)
835 {
836 	*bl += sprintf(b + *bl, "Status: ");
837 	if (dev->export_count)
838 		*bl += sprintf(b + *bl, "ACTIVATED");
839 	else
840 		*bl += sprintf(b + *bl, "DEACTIVATED");
841 
842 	*bl += sprintf(b + *bl, "  Max Queue Depth: %d", dev->queue_depth);
843 	*bl += sprintf(b + *bl, "  SectorSize: %u  HwMaxSectors: %u\n",
844 		dev->dev_attrib.block_size,
845 		dev->dev_attrib.hw_max_sectors);
846 	*bl += sprintf(b + *bl, "        ");
847 }
848 
849 void transport_dump_vpd_proto_id(
850 	struct t10_vpd *vpd,
851 	unsigned char *p_buf,
852 	int p_buf_len)
853 {
854 	unsigned char buf[VPD_TMP_BUF_SIZE];
855 	int len;
856 
857 	memset(buf, 0, VPD_TMP_BUF_SIZE);
858 	len = sprintf(buf, "T10 VPD Protocol Identifier: ");
859 
860 	switch (vpd->protocol_identifier) {
861 	case 0x00:
862 		sprintf(buf+len, "Fibre Channel\n");
863 		break;
864 	case 0x10:
865 		sprintf(buf+len, "Parallel SCSI\n");
866 		break;
867 	case 0x20:
868 		sprintf(buf+len, "SSA\n");
869 		break;
870 	case 0x30:
871 		sprintf(buf+len, "IEEE 1394\n");
872 		break;
873 	case 0x40:
874 		sprintf(buf+len, "SCSI Remote Direct Memory Access"
875 				" Protocol\n");
876 		break;
877 	case 0x50:
878 		sprintf(buf+len, "Internet SCSI (iSCSI)\n");
879 		break;
880 	case 0x60:
881 		sprintf(buf+len, "SAS Serial SCSI Protocol\n");
882 		break;
883 	case 0x70:
884 		sprintf(buf+len, "Automation/Drive Interface Transport"
885 				" Protocol\n");
886 		break;
887 	case 0x80:
888 		sprintf(buf+len, "AT Attachment Interface ATA/ATAPI\n");
889 		break;
890 	default:
891 		sprintf(buf+len, "Unknown 0x%02x\n",
892 				vpd->protocol_identifier);
893 		break;
894 	}
895 
896 	if (p_buf)
897 		strncpy(p_buf, buf, p_buf_len);
898 	else
899 		pr_debug("%s", buf);
900 }
901 
902 void
903 transport_set_vpd_proto_id(struct t10_vpd *vpd, unsigned char *page_83)
904 {
905 	/*
906 	 * Check if the Protocol Identifier Valid (PIV) bit is set..
907 	 *
908 	 * from spc3r23.pdf section 7.5.1
909 	 */
910 	 if (page_83[1] & 0x80) {
911 		vpd->protocol_identifier = (page_83[0] & 0xf0);
912 		vpd->protocol_identifier_set = 1;
913 		transport_dump_vpd_proto_id(vpd, NULL, 0);
914 	}
915 }
916 EXPORT_SYMBOL(transport_set_vpd_proto_id);
917 
918 int transport_dump_vpd_assoc(
919 	struct t10_vpd *vpd,
920 	unsigned char *p_buf,
921 	int p_buf_len)
922 {
923 	unsigned char buf[VPD_TMP_BUF_SIZE];
924 	int ret = 0;
925 	int len;
926 
927 	memset(buf, 0, VPD_TMP_BUF_SIZE);
928 	len = sprintf(buf, "T10 VPD Identifier Association: ");
929 
930 	switch (vpd->association) {
931 	case 0x00:
932 		sprintf(buf+len, "addressed logical unit\n");
933 		break;
934 	case 0x10:
935 		sprintf(buf+len, "target port\n");
936 		break;
937 	case 0x20:
938 		sprintf(buf+len, "SCSI target device\n");
939 		break;
940 	default:
941 		sprintf(buf+len, "Unknown 0x%02x\n", vpd->association);
942 		ret = -EINVAL;
943 		break;
944 	}
945 
946 	if (p_buf)
947 		strncpy(p_buf, buf, p_buf_len);
948 	else
949 		pr_debug("%s", buf);
950 
951 	return ret;
952 }
953 
954 int transport_set_vpd_assoc(struct t10_vpd *vpd, unsigned char *page_83)
955 {
956 	/*
957 	 * The VPD identification association..
958 	 *
959 	 * from spc3r23.pdf Section 7.6.3.1 Table 297
960 	 */
961 	vpd->association = (page_83[1] & 0x30);
962 	return transport_dump_vpd_assoc(vpd, NULL, 0);
963 }
964 EXPORT_SYMBOL(transport_set_vpd_assoc);
965 
966 int transport_dump_vpd_ident_type(
967 	struct t10_vpd *vpd,
968 	unsigned char *p_buf,
969 	int p_buf_len)
970 {
971 	unsigned char buf[VPD_TMP_BUF_SIZE];
972 	int ret = 0;
973 	int len;
974 
975 	memset(buf, 0, VPD_TMP_BUF_SIZE);
976 	len = sprintf(buf, "T10 VPD Identifier Type: ");
977 
978 	switch (vpd->device_identifier_type) {
979 	case 0x00:
980 		sprintf(buf+len, "Vendor specific\n");
981 		break;
982 	case 0x01:
983 		sprintf(buf+len, "T10 Vendor ID based\n");
984 		break;
985 	case 0x02:
986 		sprintf(buf+len, "EUI-64 based\n");
987 		break;
988 	case 0x03:
989 		sprintf(buf+len, "NAA\n");
990 		break;
991 	case 0x04:
992 		sprintf(buf+len, "Relative target port identifier\n");
993 		break;
994 	case 0x08:
995 		sprintf(buf+len, "SCSI name string\n");
996 		break;
997 	default:
998 		sprintf(buf+len, "Unsupported: 0x%02x\n",
999 				vpd->device_identifier_type);
1000 		ret = -EINVAL;
1001 		break;
1002 	}
1003 
1004 	if (p_buf) {
1005 		if (p_buf_len < strlen(buf)+1)
1006 			return -EINVAL;
1007 		strncpy(p_buf, buf, p_buf_len);
1008 	} else {
1009 		pr_debug("%s", buf);
1010 	}
1011 
1012 	return ret;
1013 }
1014 
1015 int transport_set_vpd_ident_type(struct t10_vpd *vpd, unsigned char *page_83)
1016 {
1017 	/*
1018 	 * The VPD identifier type..
1019 	 *
1020 	 * from spc3r23.pdf Section 7.6.3.1 Table 298
1021 	 */
1022 	vpd->device_identifier_type = (page_83[1] & 0x0f);
1023 	return transport_dump_vpd_ident_type(vpd, NULL, 0);
1024 }
1025 EXPORT_SYMBOL(transport_set_vpd_ident_type);
1026 
1027 int transport_dump_vpd_ident(
1028 	struct t10_vpd *vpd,
1029 	unsigned char *p_buf,
1030 	int p_buf_len)
1031 {
1032 	unsigned char buf[VPD_TMP_BUF_SIZE];
1033 	int ret = 0;
1034 
1035 	memset(buf, 0, VPD_TMP_BUF_SIZE);
1036 
1037 	switch (vpd->device_identifier_code_set) {
1038 	case 0x01: /* Binary */
1039 		snprintf(buf, sizeof(buf),
1040 			"T10 VPD Binary Device Identifier: %s\n",
1041 			&vpd->device_identifier[0]);
1042 		break;
1043 	case 0x02: /* ASCII */
1044 		snprintf(buf, sizeof(buf),
1045 			"T10 VPD ASCII Device Identifier: %s\n",
1046 			&vpd->device_identifier[0]);
1047 		break;
1048 	case 0x03: /* UTF-8 */
1049 		snprintf(buf, sizeof(buf),
1050 			"T10 VPD UTF-8 Device Identifier: %s\n",
1051 			&vpd->device_identifier[0]);
1052 		break;
1053 	default:
1054 		sprintf(buf, "T10 VPD Device Identifier encoding unsupported:"
1055 			" 0x%02x", vpd->device_identifier_code_set);
1056 		ret = -EINVAL;
1057 		break;
1058 	}
1059 
1060 	if (p_buf)
1061 		strncpy(p_buf, buf, p_buf_len);
1062 	else
1063 		pr_debug("%s", buf);
1064 
1065 	return ret;
1066 }
1067 
1068 int
1069 transport_set_vpd_ident(struct t10_vpd *vpd, unsigned char *page_83)
1070 {
1071 	static const char hex_str[] = "0123456789abcdef";
1072 	int j = 0, i = 4; /* offset to start of the identifier */
1073 
1074 	/*
1075 	 * The VPD Code Set (encoding)
1076 	 *
1077 	 * from spc3r23.pdf Section 7.6.3.1 Table 296
1078 	 */
1079 	vpd->device_identifier_code_set = (page_83[0] & 0x0f);
1080 	switch (vpd->device_identifier_code_set) {
1081 	case 0x01: /* Binary */
1082 		vpd->device_identifier[j++] =
1083 				hex_str[vpd->device_identifier_type];
1084 		while (i < (4 + page_83[3])) {
1085 			vpd->device_identifier[j++] =
1086 				hex_str[(page_83[i] & 0xf0) >> 4];
1087 			vpd->device_identifier[j++] =
1088 				hex_str[page_83[i] & 0x0f];
1089 			i++;
1090 		}
1091 		break;
1092 	case 0x02: /* ASCII */
1093 	case 0x03: /* UTF-8 */
1094 		while (i < (4 + page_83[3]))
1095 			vpd->device_identifier[j++] = page_83[i++];
1096 		break;
1097 	default:
1098 		break;
1099 	}
1100 
1101 	return transport_dump_vpd_ident(vpd, NULL, 0);
1102 }
1103 EXPORT_SYMBOL(transport_set_vpd_ident);
1104 
1105 sense_reason_t
1106 target_cmd_size_check(struct se_cmd *cmd, unsigned int size)
1107 {
1108 	struct se_device *dev = cmd->se_dev;
1109 
1110 	if (cmd->unknown_data_length) {
1111 		cmd->data_length = size;
1112 	} else if (size != cmd->data_length) {
1113 		pr_warn("TARGET_CORE[%s]: Expected Transfer Length:"
1114 			" %u does not match SCSI CDB Length: %u for SAM Opcode:"
1115 			" 0x%02x\n", cmd->se_tfo->get_fabric_name(),
1116 				cmd->data_length, size, cmd->t_task_cdb[0]);
1117 
1118 		if (cmd->data_direction == DMA_TO_DEVICE) {
1119 			pr_err("Rejecting underflow/overflow"
1120 					" WRITE data\n");
1121 			return TCM_INVALID_CDB_FIELD;
1122 		}
1123 		/*
1124 		 * Reject READ_* or WRITE_* with overflow/underflow for
1125 		 * type SCF_SCSI_DATA_CDB.
1126 		 */
1127 		if (dev->dev_attrib.block_size != 512)  {
1128 			pr_err("Failing OVERFLOW/UNDERFLOW for LBA op"
1129 				" CDB on non 512-byte sector setup subsystem"
1130 				" plugin: %s\n", dev->transport->name);
1131 			/* Returns CHECK_CONDITION + INVALID_CDB_FIELD */
1132 			return TCM_INVALID_CDB_FIELD;
1133 		}
1134 		/*
1135 		 * For the overflow case keep the existing fabric provided
1136 		 * ->data_length.  Otherwise for the underflow case, reset
1137 		 * ->data_length to the smaller SCSI expected data transfer
1138 		 * length.
1139 		 */
1140 		if (size > cmd->data_length) {
1141 			cmd->se_cmd_flags |= SCF_OVERFLOW_BIT;
1142 			cmd->residual_count = (size - cmd->data_length);
1143 		} else {
1144 			cmd->se_cmd_flags |= SCF_UNDERFLOW_BIT;
1145 			cmd->residual_count = (cmd->data_length - size);
1146 			cmd->data_length = size;
1147 		}
1148 	}
1149 
1150 	return 0;
1151 
1152 }
1153 
1154 /*
1155  * Used by fabric modules containing a local struct se_cmd within their
1156  * fabric dependent per I/O descriptor.
1157  */
1158 void transport_init_se_cmd(
1159 	struct se_cmd *cmd,
1160 	const struct target_core_fabric_ops *tfo,
1161 	struct se_session *se_sess,
1162 	u32 data_length,
1163 	int data_direction,
1164 	int task_attr,
1165 	unsigned char *sense_buffer)
1166 {
1167 	INIT_LIST_HEAD(&cmd->se_delayed_node);
1168 	INIT_LIST_HEAD(&cmd->se_qf_node);
1169 	INIT_LIST_HEAD(&cmd->se_cmd_list);
1170 	INIT_LIST_HEAD(&cmd->state_list);
1171 	init_completion(&cmd->t_transport_stop_comp);
1172 	init_completion(&cmd->cmd_wait_comp);
1173 	init_completion(&cmd->task_stop_comp);
1174 	spin_lock_init(&cmd->t_state_lock);
1175 	kref_init(&cmd->cmd_kref);
1176 	cmd->transport_state = CMD_T_DEV_ACTIVE;
1177 
1178 	cmd->se_tfo = tfo;
1179 	cmd->se_sess = se_sess;
1180 	cmd->data_length = data_length;
1181 	cmd->data_direction = data_direction;
1182 	cmd->sam_task_attr = task_attr;
1183 	cmd->sense_buffer = sense_buffer;
1184 
1185 	cmd->state_active = false;
1186 }
1187 EXPORT_SYMBOL(transport_init_se_cmd);
1188 
1189 static sense_reason_t
1190 transport_check_alloc_task_attr(struct se_cmd *cmd)
1191 {
1192 	struct se_device *dev = cmd->se_dev;
1193 
1194 	/*
1195 	 * Check if SAM Task Attribute emulation is enabled for this
1196 	 * struct se_device storage object
1197 	 */
1198 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1199 		return 0;
1200 
1201 	if (cmd->sam_task_attr == TCM_ACA_TAG) {
1202 		pr_debug("SAM Task Attribute ACA"
1203 			" emulation is not supported\n");
1204 		return TCM_INVALID_CDB_FIELD;
1205 	}
1206 	/*
1207 	 * Used to determine when ORDERED commands should go from
1208 	 * Dormant to Active status.
1209 	 */
1210 	cmd->se_ordered_id = atomic_inc_return(&dev->dev_ordered_id);
1211 	pr_debug("Allocated se_ordered_id: %u for Task Attr: 0x%02x on %s\n",
1212 			cmd->se_ordered_id, cmd->sam_task_attr,
1213 			dev->transport->name);
1214 	return 0;
1215 }
1216 
1217 sense_reason_t
1218 target_setup_cmd_from_cdb(struct se_cmd *cmd, unsigned char *cdb)
1219 {
1220 	struct se_device *dev = cmd->se_dev;
1221 	sense_reason_t ret;
1222 
1223 	/*
1224 	 * Ensure that the received CDB is less than the max (252 + 8) bytes
1225 	 * for VARIABLE_LENGTH_CMD
1226 	 */
1227 	if (scsi_command_size(cdb) > SCSI_MAX_VARLEN_CDB_SIZE) {
1228 		pr_err("Received SCSI CDB with command_size: %d that"
1229 			" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
1230 			scsi_command_size(cdb), SCSI_MAX_VARLEN_CDB_SIZE);
1231 		return TCM_INVALID_CDB_FIELD;
1232 	}
1233 	/*
1234 	 * If the received CDB is larger than TCM_MAX_COMMAND_SIZE,
1235 	 * allocate the additional extended CDB buffer now..  Otherwise
1236 	 * setup the pointer from __t_task_cdb to t_task_cdb.
1237 	 */
1238 	if (scsi_command_size(cdb) > sizeof(cmd->__t_task_cdb)) {
1239 		cmd->t_task_cdb = kzalloc(scsi_command_size(cdb),
1240 						GFP_KERNEL);
1241 		if (!cmd->t_task_cdb) {
1242 			pr_err("Unable to allocate cmd->t_task_cdb"
1243 				" %u > sizeof(cmd->__t_task_cdb): %lu ops\n",
1244 				scsi_command_size(cdb),
1245 				(unsigned long)sizeof(cmd->__t_task_cdb));
1246 			return TCM_OUT_OF_RESOURCES;
1247 		}
1248 	} else
1249 		cmd->t_task_cdb = &cmd->__t_task_cdb[0];
1250 	/*
1251 	 * Copy the original CDB into cmd->
1252 	 */
1253 	memcpy(cmd->t_task_cdb, cdb, scsi_command_size(cdb));
1254 
1255 	trace_target_sequencer_start(cmd);
1256 
1257 	/*
1258 	 * Check for an existing UNIT ATTENTION condition
1259 	 */
1260 	ret = target_scsi3_ua_check(cmd);
1261 	if (ret)
1262 		return ret;
1263 
1264 	ret = target_alua_state_check(cmd);
1265 	if (ret)
1266 		return ret;
1267 
1268 	ret = target_check_reservation(cmd);
1269 	if (ret) {
1270 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1271 		return ret;
1272 	}
1273 
1274 	ret = dev->transport->parse_cdb(cmd);
1275 	if (ret)
1276 		return ret;
1277 
1278 	ret = transport_check_alloc_task_attr(cmd);
1279 	if (ret)
1280 		return ret;
1281 
1282 	cmd->se_cmd_flags |= SCF_SUPPORTED_SAM_OPCODE;
1283 
1284 	spin_lock(&cmd->se_lun->lun_sep_lock);
1285 	if (cmd->se_lun->lun_sep)
1286 		cmd->se_lun->lun_sep->sep_stats.cmd_pdus++;
1287 	spin_unlock(&cmd->se_lun->lun_sep_lock);
1288 	return 0;
1289 }
1290 EXPORT_SYMBOL(target_setup_cmd_from_cdb);
1291 
1292 /*
1293  * Used by fabric module frontends to queue tasks directly.
1294  * Many only be used from process context only
1295  */
1296 int transport_handle_cdb_direct(
1297 	struct se_cmd *cmd)
1298 {
1299 	sense_reason_t ret;
1300 
1301 	if (!cmd->se_lun) {
1302 		dump_stack();
1303 		pr_err("cmd->se_lun is NULL\n");
1304 		return -EINVAL;
1305 	}
1306 	if (in_interrupt()) {
1307 		dump_stack();
1308 		pr_err("transport_generic_handle_cdb cannot be called"
1309 				" from interrupt context\n");
1310 		return -EINVAL;
1311 	}
1312 	/*
1313 	 * Set TRANSPORT_NEW_CMD state and CMD_T_ACTIVE to ensure that
1314 	 * outstanding descriptors are handled correctly during shutdown via
1315 	 * transport_wait_for_tasks()
1316 	 *
1317 	 * Also, we don't take cmd->t_state_lock here as we only expect
1318 	 * this to be called for initial descriptor submission.
1319 	 */
1320 	cmd->t_state = TRANSPORT_NEW_CMD;
1321 	cmd->transport_state |= CMD_T_ACTIVE;
1322 
1323 	/*
1324 	 * transport_generic_new_cmd() is already handling QUEUE_FULL,
1325 	 * so follow TRANSPORT_NEW_CMD processing thread context usage
1326 	 * and call transport_generic_request_failure() if necessary..
1327 	 */
1328 	ret = transport_generic_new_cmd(cmd);
1329 	if (ret)
1330 		transport_generic_request_failure(cmd, ret);
1331 	return 0;
1332 }
1333 EXPORT_SYMBOL(transport_handle_cdb_direct);
1334 
1335 sense_reason_t
1336 transport_generic_map_mem_to_cmd(struct se_cmd *cmd, struct scatterlist *sgl,
1337 		u32 sgl_count, struct scatterlist *sgl_bidi, u32 sgl_bidi_count)
1338 {
1339 	if (!sgl || !sgl_count)
1340 		return 0;
1341 
1342 	/*
1343 	 * Reject SCSI data overflow with map_mem_to_cmd() as incoming
1344 	 * scatterlists already have been set to follow what the fabric
1345 	 * passes for the original expected data transfer length.
1346 	 */
1347 	if (cmd->se_cmd_flags & SCF_OVERFLOW_BIT) {
1348 		pr_warn("Rejecting SCSI DATA overflow for fabric using"
1349 			" SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC\n");
1350 		return TCM_INVALID_CDB_FIELD;
1351 	}
1352 
1353 	cmd->t_data_sg = sgl;
1354 	cmd->t_data_nents = sgl_count;
1355 
1356 	if (sgl_bidi && sgl_bidi_count) {
1357 		cmd->t_bidi_data_sg = sgl_bidi;
1358 		cmd->t_bidi_data_nents = sgl_bidi_count;
1359 	}
1360 	cmd->se_cmd_flags |= SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC;
1361 	return 0;
1362 }
1363 
1364 /*
1365  * target_submit_cmd_map_sgls - lookup unpacked lun and submit uninitialized
1366  * 			 se_cmd + use pre-allocated SGL memory.
1367  *
1368  * @se_cmd: command descriptor to submit
1369  * @se_sess: associated se_sess for endpoint
1370  * @cdb: pointer to SCSI CDB
1371  * @sense: pointer to SCSI sense buffer
1372  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1373  * @data_length: fabric expected data transfer length
1374  * @task_addr: SAM task attribute
1375  * @data_dir: DMA data direction
1376  * @flags: flags for command submission from target_sc_flags_tables
1377  * @sgl: struct scatterlist memory for unidirectional mapping
1378  * @sgl_count: scatterlist count for unidirectional mapping
1379  * @sgl_bidi: struct scatterlist memory for bidirectional READ mapping
1380  * @sgl_bidi_count: scatterlist count for bidirectional READ mapping
1381  * @sgl_prot: struct scatterlist memory protection information
1382  * @sgl_prot_count: scatterlist count for protection information
1383  *
1384  * Returns non zero to signal active I/O shutdown failure.  All other
1385  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1386  * but still return zero here.
1387  *
1388  * This may only be called from process context, and also currently
1389  * assumes internal allocation of fabric payload buffer by target-core.
1390  */
1391 int target_submit_cmd_map_sgls(struct se_cmd *se_cmd, struct se_session *se_sess,
1392 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1393 		u32 data_length, int task_attr, int data_dir, int flags,
1394 		struct scatterlist *sgl, u32 sgl_count,
1395 		struct scatterlist *sgl_bidi, u32 sgl_bidi_count,
1396 		struct scatterlist *sgl_prot, u32 sgl_prot_count)
1397 {
1398 	struct se_portal_group *se_tpg;
1399 	sense_reason_t rc;
1400 	int ret;
1401 
1402 	se_tpg = se_sess->se_tpg;
1403 	BUG_ON(!se_tpg);
1404 	BUG_ON(se_cmd->se_tfo || se_cmd->se_sess);
1405 	BUG_ON(in_interrupt());
1406 	/*
1407 	 * Initialize se_cmd for target operation.  From this point
1408 	 * exceptions are handled by sending exception status via
1409 	 * target_core_fabric_ops->queue_status() callback
1410 	 */
1411 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1412 				data_length, data_dir, task_attr, sense);
1413 	if (flags & TARGET_SCF_UNKNOWN_SIZE)
1414 		se_cmd->unknown_data_length = 1;
1415 	/*
1416 	 * Obtain struct se_cmd->cmd_kref reference and add new cmd to
1417 	 * se_sess->sess_cmd_list.  A second kref_get here is necessary
1418 	 * for fabrics using TARGET_SCF_ACK_KREF that expect a second
1419 	 * kref_put() to happen during fabric packet acknowledgement.
1420 	 */
1421 	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1422 	if (ret)
1423 		return ret;
1424 	/*
1425 	 * Signal bidirectional data payloads to target-core
1426 	 */
1427 	if (flags & TARGET_SCF_BIDI_OP)
1428 		se_cmd->se_cmd_flags |= SCF_BIDI;
1429 	/*
1430 	 * Locate se_lun pointer and attach it to struct se_cmd
1431 	 */
1432 	rc = transport_lookup_cmd_lun(se_cmd, unpacked_lun);
1433 	if (rc) {
1434 		transport_send_check_condition_and_sense(se_cmd, rc, 0);
1435 		target_put_sess_cmd(se_sess, se_cmd);
1436 		return 0;
1437 	}
1438 
1439 	rc = target_setup_cmd_from_cdb(se_cmd, cdb);
1440 	if (rc != 0) {
1441 		transport_generic_request_failure(se_cmd, rc);
1442 		return 0;
1443 	}
1444 
1445 	/*
1446 	 * Save pointers for SGLs containing protection information,
1447 	 * if present.
1448 	 */
1449 	if (sgl_prot_count) {
1450 		se_cmd->t_prot_sg = sgl_prot;
1451 		se_cmd->t_prot_nents = sgl_prot_count;
1452 	}
1453 
1454 	/*
1455 	 * When a non zero sgl_count has been passed perform SGL passthrough
1456 	 * mapping for pre-allocated fabric memory instead of having target
1457 	 * core perform an internal SGL allocation..
1458 	 */
1459 	if (sgl_count != 0) {
1460 		BUG_ON(!sgl);
1461 
1462 		/*
1463 		 * A work-around for tcm_loop as some userspace code via
1464 		 * scsi-generic do not memset their associated read buffers,
1465 		 * so go ahead and do that here for type non-data CDBs.  Also
1466 		 * note that this is currently guaranteed to be a single SGL
1467 		 * for this case by target core in target_setup_cmd_from_cdb()
1468 		 * -> transport_generic_cmd_sequencer().
1469 		 */
1470 		if (!(se_cmd->se_cmd_flags & SCF_SCSI_DATA_CDB) &&
1471 		     se_cmd->data_direction == DMA_FROM_DEVICE) {
1472 			unsigned char *buf = NULL;
1473 
1474 			if (sgl)
1475 				buf = kmap(sg_page(sgl)) + sgl->offset;
1476 
1477 			if (buf) {
1478 				memset(buf, 0, sgl->length);
1479 				kunmap(sg_page(sgl));
1480 			}
1481 		}
1482 
1483 		rc = transport_generic_map_mem_to_cmd(se_cmd, sgl, sgl_count,
1484 				sgl_bidi, sgl_bidi_count);
1485 		if (rc != 0) {
1486 			transport_generic_request_failure(se_cmd, rc);
1487 			return 0;
1488 		}
1489 	}
1490 
1491 	/*
1492 	 * Check if we need to delay processing because of ALUA
1493 	 * Active/NonOptimized primary access state..
1494 	 */
1495 	core_alua_check_nonop_delay(se_cmd);
1496 
1497 	transport_handle_cdb_direct(se_cmd);
1498 	return 0;
1499 }
1500 EXPORT_SYMBOL(target_submit_cmd_map_sgls);
1501 
1502 /*
1503  * target_submit_cmd - lookup unpacked lun and submit uninitialized se_cmd
1504  *
1505  * @se_cmd: command descriptor to submit
1506  * @se_sess: associated se_sess for endpoint
1507  * @cdb: pointer to SCSI CDB
1508  * @sense: pointer to SCSI sense buffer
1509  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1510  * @data_length: fabric expected data transfer length
1511  * @task_addr: SAM task attribute
1512  * @data_dir: DMA data direction
1513  * @flags: flags for command submission from target_sc_flags_tables
1514  *
1515  * Returns non zero to signal active I/O shutdown failure.  All other
1516  * setup exceptions will be returned as a SCSI CHECK_CONDITION response,
1517  * but still return zero here.
1518  *
1519  * This may only be called from process context, and also currently
1520  * assumes internal allocation of fabric payload buffer by target-core.
1521  *
1522  * It also assumes interal target core SGL memory allocation.
1523  */
1524 int target_submit_cmd(struct se_cmd *se_cmd, struct se_session *se_sess,
1525 		unsigned char *cdb, unsigned char *sense, u32 unpacked_lun,
1526 		u32 data_length, int task_attr, int data_dir, int flags)
1527 {
1528 	return target_submit_cmd_map_sgls(se_cmd, se_sess, cdb, sense,
1529 			unpacked_lun, data_length, task_attr, data_dir,
1530 			flags, NULL, 0, NULL, 0, NULL, 0);
1531 }
1532 EXPORT_SYMBOL(target_submit_cmd);
1533 
1534 static void target_complete_tmr_failure(struct work_struct *work)
1535 {
1536 	struct se_cmd *se_cmd = container_of(work, struct se_cmd, work);
1537 
1538 	se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
1539 	se_cmd->se_tfo->queue_tm_rsp(se_cmd);
1540 
1541 	transport_cmd_check_stop_to_fabric(se_cmd);
1542 }
1543 
1544 /**
1545  * target_submit_tmr - lookup unpacked lun and submit uninitialized se_cmd
1546  *                     for TMR CDBs
1547  *
1548  * @se_cmd: command descriptor to submit
1549  * @se_sess: associated se_sess for endpoint
1550  * @sense: pointer to SCSI sense buffer
1551  * @unpacked_lun: unpacked LUN to reference for struct se_lun
1552  * @fabric_context: fabric context for TMR req
1553  * @tm_type: Type of TM request
1554  * @gfp: gfp type for caller
1555  * @tag: referenced task tag for TMR_ABORT_TASK
1556  * @flags: submit cmd flags
1557  *
1558  * Callable from all contexts.
1559  **/
1560 
1561 int target_submit_tmr(struct se_cmd *se_cmd, struct se_session *se_sess,
1562 		unsigned char *sense, u32 unpacked_lun,
1563 		void *fabric_tmr_ptr, unsigned char tm_type,
1564 		gfp_t gfp, unsigned int tag, int flags)
1565 {
1566 	struct se_portal_group *se_tpg;
1567 	int ret;
1568 
1569 	se_tpg = se_sess->se_tpg;
1570 	BUG_ON(!se_tpg);
1571 
1572 	transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
1573 			      0, DMA_NONE, TCM_SIMPLE_TAG, sense);
1574 	/*
1575 	 * FIXME: Currently expect caller to handle se_cmd->se_tmr_req
1576 	 * allocation failure.
1577 	 */
1578 	ret = core_tmr_alloc_req(se_cmd, fabric_tmr_ptr, tm_type, gfp);
1579 	if (ret < 0)
1580 		return -ENOMEM;
1581 
1582 	if (tm_type == TMR_ABORT_TASK)
1583 		se_cmd->se_tmr_req->ref_task_tag = tag;
1584 
1585 	/* See target_submit_cmd for commentary */
1586 	ret = target_get_sess_cmd(se_sess, se_cmd, (flags & TARGET_SCF_ACK_KREF));
1587 	if (ret) {
1588 		core_tmr_release_req(se_cmd->se_tmr_req);
1589 		return ret;
1590 	}
1591 
1592 	ret = transport_lookup_tmr_lun(se_cmd, unpacked_lun);
1593 	if (ret) {
1594 		/*
1595 		 * For callback during failure handling, push this work off
1596 		 * to process context with TMR_LUN_DOES_NOT_EXIST status.
1597 		 */
1598 		INIT_WORK(&se_cmd->work, target_complete_tmr_failure);
1599 		schedule_work(&se_cmd->work);
1600 		return 0;
1601 	}
1602 	transport_generic_handle_tmr(se_cmd);
1603 	return 0;
1604 }
1605 EXPORT_SYMBOL(target_submit_tmr);
1606 
1607 /*
1608  * If the cmd is active, request it to be stopped and sleep until it
1609  * has completed.
1610  */
1611 bool target_stop_cmd(struct se_cmd *cmd, unsigned long *flags)
1612 	__releases(&cmd->t_state_lock)
1613 	__acquires(&cmd->t_state_lock)
1614 {
1615 	bool was_active = false;
1616 
1617 	if (cmd->transport_state & CMD_T_BUSY) {
1618 		cmd->transport_state |= CMD_T_REQUEST_STOP;
1619 		spin_unlock_irqrestore(&cmd->t_state_lock, *flags);
1620 
1621 		pr_debug("cmd %p waiting to complete\n", cmd);
1622 		wait_for_completion(&cmd->task_stop_comp);
1623 		pr_debug("cmd %p stopped successfully\n", cmd);
1624 
1625 		spin_lock_irqsave(&cmd->t_state_lock, *flags);
1626 		cmd->transport_state &= ~CMD_T_REQUEST_STOP;
1627 		cmd->transport_state &= ~CMD_T_BUSY;
1628 		was_active = true;
1629 	}
1630 
1631 	return was_active;
1632 }
1633 
1634 /*
1635  * Handle SAM-esque emulation for generic transport request failures.
1636  */
1637 void transport_generic_request_failure(struct se_cmd *cmd,
1638 		sense_reason_t sense_reason)
1639 {
1640 	int ret = 0;
1641 
1642 	pr_debug("-----[ Storage Engine Exception for cmd: %p ITT: 0x%08x"
1643 		" CDB: 0x%02x\n", cmd, cmd->se_tfo->get_task_tag(cmd),
1644 		cmd->t_task_cdb[0]);
1645 	pr_debug("-----[ i_state: %d t_state: %d sense_reason: %d\n",
1646 		cmd->se_tfo->get_cmd_state(cmd),
1647 		cmd->t_state, sense_reason);
1648 	pr_debug("-----[ CMD_T_ACTIVE: %d CMD_T_STOP: %d CMD_T_SENT: %d\n",
1649 		(cmd->transport_state & CMD_T_ACTIVE) != 0,
1650 		(cmd->transport_state & CMD_T_STOP) != 0,
1651 		(cmd->transport_state & CMD_T_SENT) != 0);
1652 
1653 	/*
1654 	 * For SAM Task Attribute emulation for failed struct se_cmd
1655 	 */
1656 	transport_complete_task_attr(cmd);
1657 	/*
1658 	 * Handle special case for COMPARE_AND_WRITE failure, where the
1659 	 * callback is expected to drop the per device ->caw_sem.
1660 	 */
1661 	if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
1662 	     cmd->transport_complete_callback)
1663 		cmd->transport_complete_callback(cmd, false);
1664 
1665 	switch (sense_reason) {
1666 	case TCM_NON_EXISTENT_LUN:
1667 	case TCM_UNSUPPORTED_SCSI_OPCODE:
1668 	case TCM_INVALID_CDB_FIELD:
1669 	case TCM_INVALID_PARAMETER_LIST:
1670 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
1671 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
1672 	case TCM_UNKNOWN_MODE_PAGE:
1673 	case TCM_WRITE_PROTECTED:
1674 	case TCM_ADDRESS_OUT_OF_RANGE:
1675 	case TCM_CHECK_CONDITION_ABORT_CMD:
1676 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
1677 	case TCM_CHECK_CONDITION_NOT_READY:
1678 	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
1679 	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
1680 	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
1681 		break;
1682 	case TCM_OUT_OF_RESOURCES:
1683 		sense_reason = TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
1684 		break;
1685 	case TCM_RESERVATION_CONFLICT:
1686 		/*
1687 		 * No SENSE Data payload for this case, set SCSI Status
1688 		 * and queue the response to $FABRIC_MOD.
1689 		 *
1690 		 * Uses linux/include/scsi/scsi.h SAM status codes defs
1691 		 */
1692 		cmd->scsi_status = SAM_STAT_RESERVATION_CONFLICT;
1693 		/*
1694 		 * For UA Interlock Code 11b, a RESERVATION CONFLICT will
1695 		 * establish a UNIT ATTENTION with PREVIOUS RESERVATION
1696 		 * CONFLICT STATUS.
1697 		 *
1698 		 * See spc4r17, section 7.4.6 Control Mode Page, Table 349
1699 		 */
1700 		if (cmd->se_sess &&
1701 		    cmd->se_dev->dev_attrib.emulate_ua_intlck_ctrl == 2)
1702 			core_scsi3_ua_allocate(cmd->se_sess->se_node_acl,
1703 				cmd->orig_fe_lun, 0x2C,
1704 				ASCQ_2CH_PREVIOUS_RESERVATION_CONFLICT_STATUS);
1705 
1706 		trace_target_cmd_complete(cmd);
1707 		ret = cmd->se_tfo-> queue_status(cmd);
1708 		if (ret == -EAGAIN || ret == -ENOMEM)
1709 			goto queue_full;
1710 		goto check_stop;
1711 	default:
1712 		pr_err("Unknown transport error for CDB 0x%02x: %d\n",
1713 			cmd->t_task_cdb[0], sense_reason);
1714 		sense_reason = TCM_UNSUPPORTED_SCSI_OPCODE;
1715 		break;
1716 	}
1717 
1718 	ret = transport_send_check_condition_and_sense(cmd, sense_reason, 0);
1719 	if (ret == -EAGAIN || ret == -ENOMEM)
1720 		goto queue_full;
1721 
1722 check_stop:
1723 	transport_lun_remove_cmd(cmd);
1724 	if (!transport_cmd_check_stop_to_fabric(cmd))
1725 		;
1726 	return;
1727 
1728 queue_full:
1729 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
1730 	transport_handle_queue_full(cmd, cmd->se_dev);
1731 }
1732 EXPORT_SYMBOL(transport_generic_request_failure);
1733 
1734 void __target_execute_cmd(struct se_cmd *cmd)
1735 {
1736 	sense_reason_t ret;
1737 
1738 	if (cmd->execute_cmd) {
1739 		ret = cmd->execute_cmd(cmd);
1740 		if (ret) {
1741 			spin_lock_irq(&cmd->t_state_lock);
1742 			cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1743 			spin_unlock_irq(&cmd->t_state_lock);
1744 
1745 			transport_generic_request_failure(cmd, ret);
1746 		}
1747 	}
1748 }
1749 
1750 static int target_write_prot_action(struct se_cmd *cmd)
1751 {
1752 	u32 sectors;
1753 	/*
1754 	 * Perform WRITE_INSERT of PI using software emulation when backend
1755 	 * device has PI enabled, if the transport has not already generated
1756 	 * PI using hardware WRITE_INSERT offload.
1757 	 */
1758 	switch (cmd->prot_op) {
1759 	case TARGET_PROT_DOUT_INSERT:
1760 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_INSERT))
1761 			sbc_dif_generate(cmd);
1762 		break;
1763 	case TARGET_PROT_DOUT_STRIP:
1764 		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DOUT_STRIP)
1765 			break;
1766 
1767 		sectors = cmd->data_length >> ilog2(cmd->se_dev->dev_attrib.block_size);
1768 		cmd->pi_err = sbc_dif_verify_write(cmd, cmd->t_task_lba,
1769 						   sectors, 0, NULL, 0);
1770 		if (unlikely(cmd->pi_err)) {
1771 			spin_lock_irq(&cmd->t_state_lock);
1772 			cmd->transport_state &= ~(CMD_T_BUSY|CMD_T_SENT);
1773 			spin_unlock_irq(&cmd->t_state_lock);
1774 			transport_generic_request_failure(cmd, cmd->pi_err);
1775 			return -1;
1776 		}
1777 		break;
1778 	default:
1779 		break;
1780 	}
1781 
1782 	return 0;
1783 }
1784 
1785 static bool target_handle_task_attr(struct se_cmd *cmd)
1786 {
1787 	struct se_device *dev = cmd->se_dev;
1788 
1789 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1790 		return false;
1791 
1792 	/*
1793 	 * Check for the existence of HEAD_OF_QUEUE, and if true return 1
1794 	 * to allow the passed struct se_cmd list of tasks to the front of the list.
1795 	 */
1796 	switch (cmd->sam_task_attr) {
1797 	case TCM_HEAD_TAG:
1798 		pr_debug("Added HEAD_OF_QUEUE for CDB: 0x%02x, "
1799 			 "se_ordered_id: %u\n",
1800 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1801 		return false;
1802 	case TCM_ORDERED_TAG:
1803 		atomic_inc_mb(&dev->dev_ordered_sync);
1804 
1805 		pr_debug("Added ORDERED for CDB: 0x%02x to ordered list, "
1806 			 " se_ordered_id: %u\n",
1807 			 cmd->t_task_cdb[0], cmd->se_ordered_id);
1808 
1809 		/*
1810 		 * Execute an ORDERED command if no other older commands
1811 		 * exist that need to be completed first.
1812 		 */
1813 		if (!atomic_read(&dev->simple_cmds))
1814 			return false;
1815 		break;
1816 	default:
1817 		/*
1818 		 * For SIMPLE and UNTAGGED Task Attribute commands
1819 		 */
1820 		atomic_inc_mb(&dev->simple_cmds);
1821 		break;
1822 	}
1823 
1824 	if (atomic_read(&dev->dev_ordered_sync) == 0)
1825 		return false;
1826 
1827 	spin_lock(&dev->delayed_cmd_lock);
1828 	list_add_tail(&cmd->se_delayed_node, &dev->delayed_cmd_list);
1829 	spin_unlock(&dev->delayed_cmd_lock);
1830 
1831 	pr_debug("Added CDB: 0x%02x Task Attr: 0x%02x to"
1832 		" delayed CMD list, se_ordered_id: %u\n",
1833 		cmd->t_task_cdb[0], cmd->sam_task_attr,
1834 		cmd->se_ordered_id);
1835 	return true;
1836 }
1837 
1838 void target_execute_cmd(struct se_cmd *cmd)
1839 {
1840 	/*
1841 	 * If the received CDB has aleady been aborted stop processing it here.
1842 	 */
1843 	if (transport_check_aborted_status(cmd, 1))
1844 		return;
1845 
1846 	/*
1847 	 * Determine if frontend context caller is requesting the stopping of
1848 	 * this command for frontend exceptions.
1849 	 */
1850 	spin_lock_irq(&cmd->t_state_lock);
1851 	if (cmd->transport_state & CMD_T_STOP) {
1852 		pr_debug("%s:%d CMD_T_STOP for ITT: 0x%08x\n",
1853 			__func__, __LINE__,
1854 			cmd->se_tfo->get_task_tag(cmd));
1855 
1856 		spin_unlock_irq(&cmd->t_state_lock);
1857 		complete_all(&cmd->t_transport_stop_comp);
1858 		return;
1859 	}
1860 
1861 	cmd->t_state = TRANSPORT_PROCESSING;
1862 	cmd->transport_state |= CMD_T_ACTIVE|CMD_T_BUSY|CMD_T_SENT;
1863 	spin_unlock_irq(&cmd->t_state_lock);
1864 
1865 	if (target_write_prot_action(cmd))
1866 		return;
1867 
1868 	if (target_handle_task_attr(cmd)) {
1869 		spin_lock_irq(&cmd->t_state_lock);
1870 		cmd->transport_state &= ~(CMD_T_BUSY | CMD_T_SENT);
1871 		spin_unlock_irq(&cmd->t_state_lock);
1872 		return;
1873 	}
1874 
1875 	__target_execute_cmd(cmd);
1876 }
1877 EXPORT_SYMBOL(target_execute_cmd);
1878 
1879 /*
1880  * Process all commands up to the last received ORDERED task attribute which
1881  * requires another blocking boundary
1882  */
1883 static void target_restart_delayed_cmds(struct se_device *dev)
1884 {
1885 	for (;;) {
1886 		struct se_cmd *cmd;
1887 
1888 		spin_lock(&dev->delayed_cmd_lock);
1889 		if (list_empty(&dev->delayed_cmd_list)) {
1890 			spin_unlock(&dev->delayed_cmd_lock);
1891 			break;
1892 		}
1893 
1894 		cmd = list_entry(dev->delayed_cmd_list.next,
1895 				 struct se_cmd, se_delayed_node);
1896 		list_del(&cmd->se_delayed_node);
1897 		spin_unlock(&dev->delayed_cmd_lock);
1898 
1899 		__target_execute_cmd(cmd);
1900 
1901 		if (cmd->sam_task_attr == TCM_ORDERED_TAG)
1902 			break;
1903 	}
1904 }
1905 
1906 /*
1907  * Called from I/O completion to determine which dormant/delayed
1908  * and ordered cmds need to have their tasks added to the execution queue.
1909  */
1910 static void transport_complete_task_attr(struct se_cmd *cmd)
1911 {
1912 	struct se_device *dev = cmd->se_dev;
1913 
1914 	if (dev->transport->transport_flags & TRANSPORT_FLAG_PASSTHROUGH)
1915 		return;
1916 
1917 	if (cmd->sam_task_attr == TCM_SIMPLE_TAG) {
1918 		atomic_dec_mb(&dev->simple_cmds);
1919 		dev->dev_cur_ordered_id++;
1920 		pr_debug("Incremented dev->dev_cur_ordered_id: %u for"
1921 			" SIMPLE: %u\n", dev->dev_cur_ordered_id,
1922 			cmd->se_ordered_id);
1923 	} else if (cmd->sam_task_attr == TCM_HEAD_TAG) {
1924 		dev->dev_cur_ordered_id++;
1925 		pr_debug("Incremented dev_cur_ordered_id: %u for"
1926 			" HEAD_OF_QUEUE: %u\n", dev->dev_cur_ordered_id,
1927 			cmd->se_ordered_id);
1928 	} else if (cmd->sam_task_attr == TCM_ORDERED_TAG) {
1929 		atomic_dec_mb(&dev->dev_ordered_sync);
1930 
1931 		dev->dev_cur_ordered_id++;
1932 		pr_debug("Incremented dev_cur_ordered_id: %u for ORDERED:"
1933 			" %u\n", dev->dev_cur_ordered_id, cmd->se_ordered_id);
1934 	}
1935 
1936 	target_restart_delayed_cmds(dev);
1937 }
1938 
1939 static void transport_complete_qf(struct se_cmd *cmd)
1940 {
1941 	int ret = 0;
1942 
1943 	transport_complete_task_attr(cmd);
1944 
1945 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
1946 		trace_target_cmd_complete(cmd);
1947 		ret = cmd->se_tfo->queue_status(cmd);
1948 		goto out;
1949 	}
1950 
1951 	switch (cmd->data_direction) {
1952 	case DMA_FROM_DEVICE:
1953 		trace_target_cmd_complete(cmd);
1954 		ret = cmd->se_tfo->queue_data_in(cmd);
1955 		break;
1956 	case DMA_TO_DEVICE:
1957 		if (cmd->se_cmd_flags & SCF_BIDI) {
1958 			ret = cmd->se_tfo->queue_data_in(cmd);
1959 			break;
1960 		}
1961 		/* Fall through for DMA_TO_DEVICE */
1962 	case DMA_NONE:
1963 		trace_target_cmd_complete(cmd);
1964 		ret = cmd->se_tfo->queue_status(cmd);
1965 		break;
1966 	default:
1967 		break;
1968 	}
1969 
1970 out:
1971 	if (ret < 0) {
1972 		transport_handle_queue_full(cmd, cmd->se_dev);
1973 		return;
1974 	}
1975 	transport_lun_remove_cmd(cmd);
1976 	transport_cmd_check_stop_to_fabric(cmd);
1977 }
1978 
1979 static void transport_handle_queue_full(
1980 	struct se_cmd *cmd,
1981 	struct se_device *dev)
1982 {
1983 	spin_lock_irq(&dev->qf_cmd_lock);
1984 	list_add_tail(&cmd->se_qf_node, &cmd->se_dev->qf_cmd_list);
1985 	atomic_inc_mb(&dev->dev_qf_count);
1986 	spin_unlock_irq(&cmd->se_dev->qf_cmd_lock);
1987 
1988 	schedule_work(&cmd->se_dev->qf_work_queue);
1989 }
1990 
1991 static bool target_read_prot_action(struct se_cmd *cmd)
1992 {
1993 	sense_reason_t rc;
1994 
1995 	switch (cmd->prot_op) {
1996 	case TARGET_PROT_DIN_STRIP:
1997 		if (!(cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_STRIP)) {
1998 			rc = sbc_dif_read_strip(cmd);
1999 			if (rc) {
2000 				cmd->pi_err = rc;
2001 				return true;
2002 			}
2003 		}
2004 		break;
2005 	case TARGET_PROT_DIN_INSERT:
2006 		if (cmd->se_sess->sup_prot_ops & TARGET_PROT_DIN_INSERT)
2007 			break;
2008 
2009 		sbc_dif_generate(cmd);
2010 		break;
2011 	default:
2012 		break;
2013 	}
2014 
2015 	return false;
2016 }
2017 
2018 static void target_complete_ok_work(struct work_struct *work)
2019 {
2020 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
2021 	int ret;
2022 
2023 	/*
2024 	 * Check if we need to move delayed/dormant tasks from cmds on the
2025 	 * delayed execution list after a HEAD_OF_QUEUE or ORDERED Task
2026 	 * Attribute.
2027 	 */
2028 	transport_complete_task_attr(cmd);
2029 
2030 	/*
2031 	 * Check to schedule QUEUE_FULL work, or execute an existing
2032 	 * cmd->transport_qf_callback()
2033 	 */
2034 	if (atomic_read(&cmd->se_dev->dev_qf_count) != 0)
2035 		schedule_work(&cmd->se_dev->qf_work_queue);
2036 
2037 	/*
2038 	 * Check if we need to send a sense buffer from
2039 	 * the struct se_cmd in question.
2040 	 */
2041 	if (cmd->se_cmd_flags & SCF_TRANSPORT_TASK_SENSE) {
2042 		WARN_ON(!cmd->scsi_status);
2043 		ret = transport_send_check_condition_and_sense(
2044 					cmd, 0, 1);
2045 		if (ret == -EAGAIN || ret == -ENOMEM)
2046 			goto queue_full;
2047 
2048 		transport_lun_remove_cmd(cmd);
2049 		transport_cmd_check_stop_to_fabric(cmd);
2050 		return;
2051 	}
2052 	/*
2053 	 * Check for a callback, used by amongst other things
2054 	 * XDWRITE_READ_10 and COMPARE_AND_WRITE emulation.
2055 	 */
2056 	if (cmd->transport_complete_callback) {
2057 		sense_reason_t rc;
2058 
2059 		rc = cmd->transport_complete_callback(cmd, true);
2060 		if (!rc && !(cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE_POST)) {
2061 			if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2062 			    !cmd->data_length)
2063 				goto queue_rsp;
2064 
2065 			return;
2066 		} else if (rc) {
2067 			ret = transport_send_check_condition_and_sense(cmd,
2068 						rc, 0);
2069 			if (ret == -EAGAIN || ret == -ENOMEM)
2070 				goto queue_full;
2071 
2072 			transport_lun_remove_cmd(cmd);
2073 			transport_cmd_check_stop_to_fabric(cmd);
2074 			return;
2075 		}
2076 	}
2077 
2078 queue_rsp:
2079 	switch (cmd->data_direction) {
2080 	case DMA_FROM_DEVICE:
2081 		spin_lock(&cmd->se_lun->lun_sep_lock);
2082 		if (cmd->se_lun->lun_sep) {
2083 			cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
2084 					cmd->data_length;
2085 		}
2086 		spin_unlock(&cmd->se_lun->lun_sep_lock);
2087 		/*
2088 		 * Perform READ_STRIP of PI using software emulation when
2089 		 * backend had PI enabled, if the transport will not be
2090 		 * performing hardware READ_STRIP offload.
2091 		 */
2092 		if (target_read_prot_action(cmd)) {
2093 			ret = transport_send_check_condition_and_sense(cmd,
2094 						cmd->pi_err, 0);
2095 			if (ret == -EAGAIN || ret == -ENOMEM)
2096 				goto queue_full;
2097 
2098 			transport_lun_remove_cmd(cmd);
2099 			transport_cmd_check_stop_to_fabric(cmd);
2100 			return;
2101 		}
2102 
2103 		trace_target_cmd_complete(cmd);
2104 		ret = cmd->se_tfo->queue_data_in(cmd);
2105 		if (ret == -EAGAIN || ret == -ENOMEM)
2106 			goto queue_full;
2107 		break;
2108 	case DMA_TO_DEVICE:
2109 		spin_lock(&cmd->se_lun->lun_sep_lock);
2110 		if (cmd->se_lun->lun_sep) {
2111 			cmd->se_lun->lun_sep->sep_stats.rx_data_octets +=
2112 				cmd->data_length;
2113 		}
2114 		spin_unlock(&cmd->se_lun->lun_sep_lock);
2115 		/*
2116 		 * Check if we need to send READ payload for BIDI-COMMAND
2117 		 */
2118 		if (cmd->se_cmd_flags & SCF_BIDI) {
2119 			spin_lock(&cmd->se_lun->lun_sep_lock);
2120 			if (cmd->se_lun->lun_sep) {
2121 				cmd->se_lun->lun_sep->sep_stats.tx_data_octets +=
2122 					cmd->data_length;
2123 			}
2124 			spin_unlock(&cmd->se_lun->lun_sep_lock);
2125 			ret = cmd->se_tfo->queue_data_in(cmd);
2126 			if (ret == -EAGAIN || ret == -ENOMEM)
2127 				goto queue_full;
2128 			break;
2129 		}
2130 		/* Fall through for DMA_TO_DEVICE */
2131 	case DMA_NONE:
2132 		trace_target_cmd_complete(cmd);
2133 		ret = cmd->se_tfo->queue_status(cmd);
2134 		if (ret == -EAGAIN || ret == -ENOMEM)
2135 			goto queue_full;
2136 		break;
2137 	default:
2138 		break;
2139 	}
2140 
2141 	transport_lun_remove_cmd(cmd);
2142 	transport_cmd_check_stop_to_fabric(cmd);
2143 	return;
2144 
2145 queue_full:
2146 	pr_debug("Handling complete_ok QUEUE_FULL: se_cmd: %p,"
2147 		" data_direction: %d\n", cmd, cmd->data_direction);
2148 	cmd->t_state = TRANSPORT_COMPLETE_QF_OK;
2149 	transport_handle_queue_full(cmd, cmd->se_dev);
2150 }
2151 
2152 static inline void transport_free_sgl(struct scatterlist *sgl, int nents)
2153 {
2154 	struct scatterlist *sg;
2155 	int count;
2156 
2157 	for_each_sg(sgl, sg, nents, count)
2158 		__free_page(sg_page(sg));
2159 
2160 	kfree(sgl);
2161 }
2162 
2163 static inline void transport_reset_sgl_orig(struct se_cmd *cmd)
2164 {
2165 	/*
2166 	 * Check for saved t_data_sg that may be used for COMPARE_AND_WRITE
2167 	 * emulation, and free + reset pointers if necessary..
2168 	 */
2169 	if (!cmd->t_data_sg_orig)
2170 		return;
2171 
2172 	kfree(cmd->t_data_sg);
2173 	cmd->t_data_sg = cmd->t_data_sg_orig;
2174 	cmd->t_data_sg_orig = NULL;
2175 	cmd->t_data_nents = cmd->t_data_nents_orig;
2176 	cmd->t_data_nents_orig = 0;
2177 }
2178 
2179 static inline void transport_free_pages(struct se_cmd *cmd)
2180 {
2181 	if (cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) {
2182 		/*
2183 		 * Release special case READ buffer payload required for
2184 		 * SG_TO_MEM_NOALLOC to function with COMPARE_AND_WRITE
2185 		 */
2186 		if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) {
2187 			transport_free_sgl(cmd->t_bidi_data_sg,
2188 					   cmd->t_bidi_data_nents);
2189 			cmd->t_bidi_data_sg = NULL;
2190 			cmd->t_bidi_data_nents = 0;
2191 		}
2192 		transport_reset_sgl_orig(cmd);
2193 		return;
2194 	}
2195 	transport_reset_sgl_orig(cmd);
2196 
2197 	transport_free_sgl(cmd->t_data_sg, cmd->t_data_nents);
2198 	cmd->t_data_sg = NULL;
2199 	cmd->t_data_nents = 0;
2200 
2201 	transport_free_sgl(cmd->t_bidi_data_sg, cmd->t_bidi_data_nents);
2202 	cmd->t_bidi_data_sg = NULL;
2203 	cmd->t_bidi_data_nents = 0;
2204 
2205 	transport_free_sgl(cmd->t_prot_sg, cmd->t_prot_nents);
2206 	cmd->t_prot_sg = NULL;
2207 	cmd->t_prot_nents = 0;
2208 }
2209 
2210 /**
2211  * transport_release_cmd - free a command
2212  * @cmd:       command to free
2213  *
2214  * This routine unconditionally frees a command, and reference counting
2215  * or list removal must be done in the caller.
2216  */
2217 static int transport_release_cmd(struct se_cmd *cmd)
2218 {
2219 	BUG_ON(!cmd->se_tfo);
2220 
2221 	if (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)
2222 		core_tmr_release_req(cmd->se_tmr_req);
2223 	if (cmd->t_task_cdb != cmd->__t_task_cdb)
2224 		kfree(cmd->t_task_cdb);
2225 	/*
2226 	 * If this cmd has been setup with target_get_sess_cmd(), drop
2227 	 * the kref and call ->release_cmd() in kref callback.
2228 	 */
2229 	return target_put_sess_cmd(cmd->se_sess, cmd);
2230 }
2231 
2232 /**
2233  * transport_put_cmd - release a reference to a command
2234  * @cmd:       command to release
2235  *
2236  * This routine releases our reference to the command and frees it if possible.
2237  */
2238 static int transport_put_cmd(struct se_cmd *cmd)
2239 {
2240 	transport_free_pages(cmd);
2241 	return transport_release_cmd(cmd);
2242 }
2243 
2244 void *transport_kmap_data_sg(struct se_cmd *cmd)
2245 {
2246 	struct scatterlist *sg = cmd->t_data_sg;
2247 	struct page **pages;
2248 	int i;
2249 
2250 	/*
2251 	 * We need to take into account a possible offset here for fabrics like
2252 	 * tcm_loop who may be using a contig buffer from the SCSI midlayer for
2253 	 * control CDBs passed as SGLs via transport_generic_map_mem_to_cmd()
2254 	 */
2255 	if (!cmd->t_data_nents)
2256 		return NULL;
2257 
2258 	BUG_ON(!sg);
2259 	if (cmd->t_data_nents == 1)
2260 		return kmap(sg_page(sg)) + sg->offset;
2261 
2262 	/* >1 page. use vmap */
2263 	pages = kmalloc(sizeof(*pages) * cmd->t_data_nents, GFP_KERNEL);
2264 	if (!pages)
2265 		return NULL;
2266 
2267 	/* convert sg[] to pages[] */
2268 	for_each_sg(cmd->t_data_sg, sg, cmd->t_data_nents, i) {
2269 		pages[i] = sg_page(sg);
2270 	}
2271 
2272 	cmd->t_data_vmap = vmap(pages, cmd->t_data_nents,  VM_MAP, PAGE_KERNEL);
2273 	kfree(pages);
2274 	if (!cmd->t_data_vmap)
2275 		return NULL;
2276 
2277 	return cmd->t_data_vmap + cmd->t_data_sg[0].offset;
2278 }
2279 EXPORT_SYMBOL(transport_kmap_data_sg);
2280 
2281 void transport_kunmap_data_sg(struct se_cmd *cmd)
2282 {
2283 	if (!cmd->t_data_nents) {
2284 		return;
2285 	} else if (cmd->t_data_nents == 1) {
2286 		kunmap(sg_page(cmd->t_data_sg));
2287 		return;
2288 	}
2289 
2290 	vunmap(cmd->t_data_vmap);
2291 	cmd->t_data_vmap = NULL;
2292 }
2293 EXPORT_SYMBOL(transport_kunmap_data_sg);
2294 
2295 int
2296 target_alloc_sgl(struct scatterlist **sgl, unsigned int *nents, u32 length,
2297 		 bool zero_page)
2298 {
2299 	struct scatterlist *sg;
2300 	struct page *page;
2301 	gfp_t zero_flag = (zero_page) ? __GFP_ZERO : 0;
2302 	unsigned int nent;
2303 	int i = 0;
2304 
2305 	nent = DIV_ROUND_UP(length, PAGE_SIZE);
2306 	sg = kmalloc(sizeof(struct scatterlist) * nent, GFP_KERNEL);
2307 	if (!sg)
2308 		return -ENOMEM;
2309 
2310 	sg_init_table(sg, nent);
2311 
2312 	while (length) {
2313 		u32 page_len = min_t(u32, length, PAGE_SIZE);
2314 		page = alloc_page(GFP_KERNEL | zero_flag);
2315 		if (!page)
2316 			goto out;
2317 
2318 		sg_set_page(&sg[i], page, page_len, 0);
2319 		length -= page_len;
2320 		i++;
2321 	}
2322 	*sgl = sg;
2323 	*nents = nent;
2324 	return 0;
2325 
2326 out:
2327 	while (i > 0) {
2328 		i--;
2329 		__free_page(sg_page(&sg[i]));
2330 	}
2331 	kfree(sg);
2332 	return -ENOMEM;
2333 }
2334 
2335 /*
2336  * Allocate any required resources to execute the command.  For writes we
2337  * might not have the payload yet, so notify the fabric via a call to
2338  * ->write_pending instead. Otherwise place it on the execution queue.
2339  */
2340 sense_reason_t
2341 transport_generic_new_cmd(struct se_cmd *cmd)
2342 {
2343 	int ret = 0;
2344 	bool zero_flag = !(cmd->se_cmd_flags & SCF_SCSI_DATA_CDB);
2345 
2346 	/*
2347 	 * Determine is the TCM fabric module has already allocated physical
2348 	 * memory, and is directly calling transport_generic_map_mem_to_cmd()
2349 	 * beforehand.
2350 	 */
2351 	if (!(cmd->se_cmd_flags & SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC) &&
2352 	    cmd->data_length) {
2353 
2354 		if ((cmd->se_cmd_flags & SCF_BIDI) ||
2355 		    (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)) {
2356 			u32 bidi_length;
2357 
2358 			if (cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE)
2359 				bidi_length = cmd->t_task_nolb *
2360 					      cmd->se_dev->dev_attrib.block_size;
2361 			else
2362 				bidi_length = cmd->data_length;
2363 
2364 			ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2365 					       &cmd->t_bidi_data_nents,
2366 					       bidi_length, zero_flag);
2367 			if (ret < 0)
2368 				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2369 		}
2370 
2371 		if (cmd->prot_op != TARGET_PROT_NORMAL) {
2372 			ret = target_alloc_sgl(&cmd->t_prot_sg,
2373 					       &cmd->t_prot_nents,
2374 					       cmd->prot_length, true);
2375 			if (ret < 0)
2376 				return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2377 		}
2378 
2379 		ret = target_alloc_sgl(&cmd->t_data_sg, &cmd->t_data_nents,
2380 				       cmd->data_length, zero_flag);
2381 		if (ret < 0)
2382 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2383 	} else if ((cmd->se_cmd_flags & SCF_COMPARE_AND_WRITE) &&
2384 		    cmd->data_length) {
2385 		/*
2386 		 * Special case for COMPARE_AND_WRITE with fabrics
2387 		 * using SCF_PASSTHROUGH_SG_TO_MEM_NOALLOC.
2388 		 */
2389 		u32 caw_length = cmd->t_task_nolb *
2390 				 cmd->se_dev->dev_attrib.block_size;
2391 
2392 		ret = target_alloc_sgl(&cmd->t_bidi_data_sg,
2393 				       &cmd->t_bidi_data_nents,
2394 				       caw_length, zero_flag);
2395 		if (ret < 0)
2396 			return TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2397 	}
2398 	/*
2399 	 * If this command is not a write we can execute it right here,
2400 	 * for write buffers we need to notify the fabric driver first
2401 	 * and let it call back once the write buffers are ready.
2402 	 */
2403 	target_add_to_state_list(cmd);
2404 	if (cmd->data_direction != DMA_TO_DEVICE || cmd->data_length == 0) {
2405 		target_execute_cmd(cmd);
2406 		return 0;
2407 	}
2408 	transport_cmd_check_stop(cmd, false, true);
2409 
2410 	ret = cmd->se_tfo->write_pending(cmd);
2411 	if (ret == -EAGAIN || ret == -ENOMEM)
2412 		goto queue_full;
2413 
2414 	/* fabric drivers should only return -EAGAIN or -ENOMEM as error */
2415 	WARN_ON(ret);
2416 
2417 	return (!ret) ? 0 : TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE;
2418 
2419 queue_full:
2420 	pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n", cmd);
2421 	cmd->t_state = TRANSPORT_COMPLETE_QF_WP;
2422 	transport_handle_queue_full(cmd, cmd->se_dev);
2423 	return 0;
2424 }
2425 EXPORT_SYMBOL(transport_generic_new_cmd);
2426 
2427 static void transport_write_pending_qf(struct se_cmd *cmd)
2428 {
2429 	int ret;
2430 
2431 	ret = cmd->se_tfo->write_pending(cmd);
2432 	if (ret == -EAGAIN || ret == -ENOMEM) {
2433 		pr_debug("Handling write_pending QUEUE__FULL: se_cmd: %p\n",
2434 			 cmd);
2435 		transport_handle_queue_full(cmd, cmd->se_dev);
2436 	}
2437 }
2438 
2439 int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
2440 {
2441 	unsigned long flags;
2442 	int ret = 0;
2443 
2444 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD)) {
2445 		if (wait_for_tasks && (cmd->se_cmd_flags & SCF_SCSI_TMR_CDB))
2446 			 transport_wait_for_tasks(cmd);
2447 
2448 		ret = transport_release_cmd(cmd);
2449 	} else {
2450 		if (wait_for_tasks)
2451 			transport_wait_for_tasks(cmd);
2452 		/*
2453 		 * Handle WRITE failure case where transport_generic_new_cmd()
2454 		 * has already added se_cmd to state_list, but fabric has
2455 		 * failed command before I/O submission.
2456 		 */
2457 		if (cmd->state_active) {
2458 			spin_lock_irqsave(&cmd->t_state_lock, flags);
2459 			target_remove_from_state_list(cmd);
2460 			spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2461 		}
2462 
2463 		if (cmd->se_lun)
2464 			transport_lun_remove_cmd(cmd);
2465 
2466 		ret = transport_put_cmd(cmd);
2467 	}
2468 	return ret;
2469 }
2470 EXPORT_SYMBOL(transport_generic_free_cmd);
2471 
2472 /* target_get_sess_cmd - Add command to active ->sess_cmd_list
2473  * @se_sess:	session to reference
2474  * @se_cmd:	command descriptor to add
2475  * @ack_kref:	Signal that fabric will perform an ack target_put_sess_cmd()
2476  */
2477 int target_get_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd,
2478 			       bool ack_kref)
2479 {
2480 	unsigned long flags;
2481 	int ret = 0;
2482 
2483 	/*
2484 	 * Add a second kref if the fabric caller is expecting to handle
2485 	 * fabric acknowledgement that requires two target_put_sess_cmd()
2486 	 * invocations before se_cmd descriptor release.
2487 	 */
2488 	if (ack_kref)
2489 		kref_get(&se_cmd->cmd_kref);
2490 
2491 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2492 	if (se_sess->sess_tearing_down) {
2493 		ret = -ESHUTDOWN;
2494 		goto out;
2495 	}
2496 	list_add_tail(&se_cmd->se_cmd_list, &se_sess->sess_cmd_list);
2497 out:
2498 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2499 
2500 	if (ret && ack_kref)
2501 		target_put_sess_cmd(se_sess, se_cmd);
2502 
2503 	return ret;
2504 }
2505 EXPORT_SYMBOL(target_get_sess_cmd);
2506 
2507 static void target_release_cmd_kref(struct kref *kref)
2508 		__releases(&se_cmd->se_sess->sess_cmd_lock)
2509 {
2510 	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);
2511 	struct se_session *se_sess = se_cmd->se_sess;
2512 
2513 	if (list_empty(&se_cmd->se_cmd_list)) {
2514 		spin_unlock(&se_sess->sess_cmd_lock);
2515 		se_cmd->se_tfo->release_cmd(se_cmd);
2516 		return;
2517 	}
2518 	if (se_sess->sess_tearing_down && se_cmd->cmd_wait_set) {
2519 		spin_unlock(&se_sess->sess_cmd_lock);
2520 		complete(&se_cmd->cmd_wait_comp);
2521 		return;
2522 	}
2523 	list_del(&se_cmd->se_cmd_list);
2524 	spin_unlock(&se_sess->sess_cmd_lock);
2525 
2526 	se_cmd->se_tfo->release_cmd(se_cmd);
2527 }
2528 
2529 /* target_put_sess_cmd - Check for active I/O shutdown via kref_put
2530  * @se_sess:	session to reference
2531  * @se_cmd:	command descriptor to drop
2532  */
2533 int target_put_sess_cmd(struct se_session *se_sess, struct se_cmd *se_cmd)
2534 {
2535 	if (!se_sess) {
2536 		se_cmd->se_tfo->release_cmd(se_cmd);
2537 		return 1;
2538 	}
2539 	return kref_put_spinlock_irqsave(&se_cmd->cmd_kref, target_release_cmd_kref,
2540 			&se_sess->sess_cmd_lock);
2541 }
2542 EXPORT_SYMBOL(target_put_sess_cmd);
2543 
2544 /* target_sess_cmd_list_set_waiting - Flag all commands in
2545  *         sess_cmd_list to complete cmd_wait_comp.  Set
2546  *         sess_tearing_down so no more commands are queued.
2547  * @se_sess:	session to flag
2548  */
2549 void target_sess_cmd_list_set_waiting(struct se_session *se_sess)
2550 {
2551 	struct se_cmd *se_cmd;
2552 	unsigned long flags;
2553 
2554 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2555 	if (se_sess->sess_tearing_down) {
2556 		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2557 		return;
2558 	}
2559 	se_sess->sess_tearing_down = 1;
2560 	list_splice_init(&se_sess->sess_cmd_list, &se_sess->sess_wait_list);
2561 
2562 	list_for_each_entry(se_cmd, &se_sess->sess_wait_list, se_cmd_list)
2563 		se_cmd->cmd_wait_set = 1;
2564 
2565 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2566 }
2567 EXPORT_SYMBOL(target_sess_cmd_list_set_waiting);
2568 
2569 /* target_wait_for_sess_cmds - Wait for outstanding descriptors
2570  * @se_sess:    session to wait for active I/O
2571  */
2572 void target_wait_for_sess_cmds(struct se_session *se_sess)
2573 {
2574 	struct se_cmd *se_cmd, *tmp_cmd;
2575 	unsigned long flags;
2576 
2577 	list_for_each_entry_safe(se_cmd, tmp_cmd,
2578 				&se_sess->sess_wait_list, se_cmd_list) {
2579 		list_del(&se_cmd->se_cmd_list);
2580 
2581 		pr_debug("Waiting for se_cmd: %p t_state: %d, fabric state:"
2582 			" %d\n", se_cmd, se_cmd->t_state,
2583 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2584 
2585 		wait_for_completion(&se_cmd->cmd_wait_comp);
2586 		pr_debug("After cmd_wait_comp: se_cmd: %p t_state: %d"
2587 			" fabric state: %d\n", se_cmd, se_cmd->t_state,
2588 			se_cmd->se_tfo->get_cmd_state(se_cmd));
2589 
2590 		se_cmd->se_tfo->release_cmd(se_cmd);
2591 	}
2592 
2593 	spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
2594 	WARN_ON(!list_empty(&se_sess->sess_cmd_list));
2595 	spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);
2596 
2597 }
2598 EXPORT_SYMBOL(target_wait_for_sess_cmds);
2599 
2600 static int transport_clear_lun_ref_thread(void *p)
2601 {
2602 	struct se_lun *lun = p;
2603 
2604 	percpu_ref_kill(&lun->lun_ref);
2605 
2606 	wait_for_completion(&lun->lun_ref_comp);
2607 	complete(&lun->lun_shutdown_comp);
2608 
2609 	return 0;
2610 }
2611 
2612 int transport_clear_lun_ref(struct se_lun *lun)
2613 {
2614 	struct task_struct *kt;
2615 
2616 	kt = kthread_run(transport_clear_lun_ref_thread, lun,
2617 			"tcm_cl_%u", lun->unpacked_lun);
2618 	if (IS_ERR(kt)) {
2619 		pr_err("Unable to start clear_lun thread\n");
2620 		return PTR_ERR(kt);
2621 	}
2622 	wait_for_completion(&lun->lun_shutdown_comp);
2623 
2624 	return 0;
2625 }
2626 
2627 /**
2628  * transport_wait_for_tasks - wait for completion to occur
2629  * @cmd:	command to wait
2630  *
2631  * Called from frontend fabric context to wait for storage engine
2632  * to pause and/or release frontend generated struct se_cmd.
2633  */
2634 bool transport_wait_for_tasks(struct se_cmd *cmd)
2635 {
2636 	unsigned long flags;
2637 
2638 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2639 	if (!(cmd->se_cmd_flags & SCF_SE_LUN_CMD) &&
2640 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2641 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2642 		return false;
2643 	}
2644 
2645 	if (!(cmd->se_cmd_flags & SCF_SUPPORTED_SAM_OPCODE) &&
2646 	    !(cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
2647 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2648 		return false;
2649 	}
2650 
2651 	if (!(cmd->transport_state & CMD_T_ACTIVE)) {
2652 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2653 		return false;
2654 	}
2655 
2656 	cmd->transport_state |= CMD_T_STOP;
2657 
2658 	pr_debug("wait_for_tasks: Stopping %p ITT: 0x%08x"
2659 		" i_state: %d, t_state: %d, CMD_T_STOP\n",
2660 		cmd, cmd->se_tfo->get_task_tag(cmd),
2661 		cmd->se_tfo->get_cmd_state(cmd), cmd->t_state);
2662 
2663 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2664 
2665 	wait_for_completion(&cmd->t_transport_stop_comp);
2666 
2667 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2668 	cmd->transport_state &= ~(CMD_T_ACTIVE | CMD_T_STOP);
2669 
2670 	pr_debug("wait_for_tasks: Stopped wait_for_completion("
2671 		"&cmd->t_transport_stop_comp) for ITT: 0x%08x\n",
2672 		cmd->se_tfo->get_task_tag(cmd));
2673 
2674 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2675 
2676 	return true;
2677 }
2678 EXPORT_SYMBOL(transport_wait_for_tasks);
2679 
2680 static int transport_get_sense_codes(
2681 	struct se_cmd *cmd,
2682 	u8 *asc,
2683 	u8 *ascq)
2684 {
2685 	*asc = cmd->scsi_asc;
2686 	*ascq = cmd->scsi_ascq;
2687 
2688 	return 0;
2689 }
2690 
2691 static
2692 void transport_err_sector_info(unsigned char *buffer, sector_t bad_sector)
2693 {
2694 	/* Place failed LBA in sense data information descriptor 0. */
2695 	buffer[SPC_ADD_SENSE_LEN_OFFSET] = 0xc;
2696 	buffer[SPC_DESC_TYPE_OFFSET] = 0; /* Information */
2697 	buffer[SPC_ADDITIONAL_DESC_LEN_OFFSET] = 0xa;
2698 	buffer[SPC_VALIDITY_OFFSET] = 0x80;
2699 
2700 	/* Descriptor Information: failing sector */
2701 	put_unaligned_be64(bad_sector, &buffer[12]);
2702 }
2703 
2704 int
2705 transport_send_check_condition_and_sense(struct se_cmd *cmd,
2706 		sense_reason_t reason, int from_transport)
2707 {
2708 	unsigned char *buffer = cmd->sense_buffer;
2709 	unsigned long flags;
2710 	u8 asc = 0, ascq = 0;
2711 
2712 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2713 	if (cmd->se_cmd_flags & SCF_SENT_CHECK_CONDITION) {
2714 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2715 		return 0;
2716 	}
2717 	cmd->se_cmd_flags |= SCF_SENT_CHECK_CONDITION;
2718 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2719 
2720 	if (!reason && from_transport)
2721 		goto after_reason;
2722 
2723 	if (!from_transport)
2724 		cmd->se_cmd_flags |= SCF_EMULATED_TASK_SENSE;
2725 
2726 	/*
2727 	 * Actual SENSE DATA, see SPC-3 7.23.2  SPC_SENSE_KEY_OFFSET uses
2728 	 * SENSE KEY values from include/scsi/scsi.h
2729 	 */
2730 	switch (reason) {
2731 	case TCM_NO_SENSE:
2732 		/* CURRENT ERROR */
2733 		buffer[0] = 0x70;
2734 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2735 		/* Not Ready */
2736 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2737 		/* NO ADDITIONAL SENSE INFORMATION */
2738 		buffer[SPC_ASC_KEY_OFFSET] = 0;
2739 		buffer[SPC_ASCQ_KEY_OFFSET] = 0;
2740 		break;
2741 	case TCM_NON_EXISTENT_LUN:
2742 		/* CURRENT ERROR */
2743 		buffer[0] = 0x70;
2744 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2745 		/* ILLEGAL REQUEST */
2746 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2747 		/* LOGICAL UNIT NOT SUPPORTED */
2748 		buffer[SPC_ASC_KEY_OFFSET] = 0x25;
2749 		break;
2750 	case TCM_UNSUPPORTED_SCSI_OPCODE:
2751 	case TCM_SECTOR_COUNT_TOO_MANY:
2752 		/* CURRENT ERROR */
2753 		buffer[0] = 0x70;
2754 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2755 		/* ILLEGAL REQUEST */
2756 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2757 		/* INVALID COMMAND OPERATION CODE */
2758 		buffer[SPC_ASC_KEY_OFFSET] = 0x20;
2759 		break;
2760 	case TCM_UNKNOWN_MODE_PAGE:
2761 		/* CURRENT ERROR */
2762 		buffer[0] = 0x70;
2763 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2764 		/* ILLEGAL REQUEST */
2765 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2766 		/* INVALID FIELD IN CDB */
2767 		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2768 		break;
2769 	case TCM_CHECK_CONDITION_ABORT_CMD:
2770 		/* CURRENT ERROR */
2771 		buffer[0] = 0x70;
2772 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2773 		/* ABORTED COMMAND */
2774 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2775 		/* BUS DEVICE RESET FUNCTION OCCURRED */
2776 		buffer[SPC_ASC_KEY_OFFSET] = 0x29;
2777 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2778 		break;
2779 	case TCM_INCORRECT_AMOUNT_OF_DATA:
2780 		/* CURRENT ERROR */
2781 		buffer[0] = 0x70;
2782 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2783 		/* ABORTED COMMAND */
2784 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2785 		/* WRITE ERROR */
2786 		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2787 		/* NOT ENOUGH UNSOLICITED DATA */
2788 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0d;
2789 		break;
2790 	case TCM_INVALID_CDB_FIELD:
2791 		/* CURRENT ERROR */
2792 		buffer[0] = 0x70;
2793 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2794 		/* ILLEGAL REQUEST */
2795 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2796 		/* INVALID FIELD IN CDB */
2797 		buffer[SPC_ASC_KEY_OFFSET] = 0x24;
2798 		break;
2799 	case TCM_INVALID_PARAMETER_LIST:
2800 		/* CURRENT ERROR */
2801 		buffer[0] = 0x70;
2802 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2803 		/* ILLEGAL REQUEST */
2804 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2805 		/* INVALID FIELD IN PARAMETER LIST */
2806 		buffer[SPC_ASC_KEY_OFFSET] = 0x26;
2807 		break;
2808 	case TCM_PARAMETER_LIST_LENGTH_ERROR:
2809 		/* CURRENT ERROR */
2810 		buffer[0] = 0x70;
2811 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2812 		/* ILLEGAL REQUEST */
2813 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2814 		/* PARAMETER LIST LENGTH ERROR */
2815 		buffer[SPC_ASC_KEY_OFFSET] = 0x1a;
2816 		break;
2817 	case TCM_UNEXPECTED_UNSOLICITED_DATA:
2818 		/* CURRENT ERROR */
2819 		buffer[0] = 0x70;
2820 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2821 		/* ABORTED COMMAND */
2822 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2823 		/* WRITE ERROR */
2824 		buffer[SPC_ASC_KEY_OFFSET] = 0x0c;
2825 		/* UNEXPECTED_UNSOLICITED_DATA */
2826 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x0c;
2827 		break;
2828 	case TCM_SERVICE_CRC_ERROR:
2829 		/* CURRENT ERROR */
2830 		buffer[0] = 0x70;
2831 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2832 		/* ABORTED COMMAND */
2833 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2834 		/* PROTOCOL SERVICE CRC ERROR */
2835 		buffer[SPC_ASC_KEY_OFFSET] = 0x47;
2836 		/* N/A */
2837 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x05;
2838 		break;
2839 	case TCM_SNACK_REJECTED:
2840 		/* CURRENT ERROR */
2841 		buffer[0] = 0x70;
2842 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2843 		/* ABORTED COMMAND */
2844 		buffer[SPC_SENSE_KEY_OFFSET] = ABORTED_COMMAND;
2845 		/* READ ERROR */
2846 		buffer[SPC_ASC_KEY_OFFSET] = 0x11;
2847 		/* FAILED RETRANSMISSION REQUEST */
2848 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x13;
2849 		break;
2850 	case TCM_WRITE_PROTECTED:
2851 		/* CURRENT ERROR */
2852 		buffer[0] = 0x70;
2853 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2854 		/* DATA PROTECT */
2855 		buffer[SPC_SENSE_KEY_OFFSET] = DATA_PROTECT;
2856 		/* WRITE PROTECTED */
2857 		buffer[SPC_ASC_KEY_OFFSET] = 0x27;
2858 		break;
2859 	case TCM_ADDRESS_OUT_OF_RANGE:
2860 		/* CURRENT ERROR */
2861 		buffer[0] = 0x70;
2862 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2863 		/* ILLEGAL REQUEST */
2864 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2865 		/* LOGICAL BLOCK ADDRESS OUT OF RANGE */
2866 		buffer[SPC_ASC_KEY_OFFSET] = 0x21;
2867 		break;
2868 	case TCM_CHECK_CONDITION_UNIT_ATTENTION:
2869 		/* CURRENT ERROR */
2870 		buffer[0] = 0x70;
2871 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2872 		/* UNIT ATTENTION */
2873 		buffer[SPC_SENSE_KEY_OFFSET] = UNIT_ATTENTION;
2874 		core_scsi3_ua_for_check_condition(cmd, &asc, &ascq);
2875 		buffer[SPC_ASC_KEY_OFFSET] = asc;
2876 		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2877 		break;
2878 	case TCM_CHECK_CONDITION_NOT_READY:
2879 		/* CURRENT ERROR */
2880 		buffer[0] = 0x70;
2881 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2882 		/* Not Ready */
2883 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2884 		transport_get_sense_codes(cmd, &asc, &ascq);
2885 		buffer[SPC_ASC_KEY_OFFSET] = asc;
2886 		buffer[SPC_ASCQ_KEY_OFFSET] = ascq;
2887 		break;
2888 	case TCM_MISCOMPARE_VERIFY:
2889 		/* CURRENT ERROR */
2890 		buffer[0] = 0x70;
2891 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2892 		buffer[SPC_SENSE_KEY_OFFSET] = MISCOMPARE;
2893 		/* MISCOMPARE DURING VERIFY OPERATION */
2894 		buffer[SPC_ASC_KEY_OFFSET] = 0x1d;
2895 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x00;
2896 		break;
2897 	case TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED:
2898 		/* CURRENT ERROR */
2899 		buffer[0] = 0x70;
2900 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2901 		/* ILLEGAL REQUEST */
2902 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2903 		/* LOGICAL BLOCK GUARD CHECK FAILED */
2904 		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2905 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x01;
2906 		transport_err_sector_info(buffer, cmd->bad_sector);
2907 		break;
2908 	case TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED:
2909 		/* CURRENT ERROR */
2910 		buffer[0] = 0x70;
2911 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2912 		/* ILLEGAL REQUEST */
2913 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2914 		/* LOGICAL BLOCK APPLICATION TAG CHECK FAILED */
2915 		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2916 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x02;
2917 		transport_err_sector_info(buffer, cmd->bad_sector);
2918 		break;
2919 	case TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED:
2920 		/* CURRENT ERROR */
2921 		buffer[0] = 0x70;
2922 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2923 		/* ILLEGAL REQUEST */
2924 		buffer[SPC_SENSE_KEY_OFFSET] = ILLEGAL_REQUEST;
2925 		/* LOGICAL BLOCK REFERENCE TAG CHECK FAILED */
2926 		buffer[SPC_ASC_KEY_OFFSET] = 0x10;
2927 		buffer[SPC_ASCQ_KEY_OFFSET] = 0x03;
2928 		transport_err_sector_info(buffer, cmd->bad_sector);
2929 		break;
2930 	case TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE:
2931 	default:
2932 		/* CURRENT ERROR */
2933 		buffer[0] = 0x70;
2934 		buffer[SPC_ADD_SENSE_LEN_OFFSET] = 10;
2935 		/*
2936 		 * Returning ILLEGAL REQUEST would cause immediate IO errors on
2937 		 * Solaris initiators.  Returning NOT READY instead means the
2938 		 * operations will be retried a finite number of times and we
2939 		 * can survive intermittent errors.
2940 		 */
2941 		buffer[SPC_SENSE_KEY_OFFSET] = NOT_READY;
2942 		/* LOGICAL UNIT COMMUNICATION FAILURE */
2943 		buffer[SPC_ASC_KEY_OFFSET] = 0x08;
2944 		break;
2945 	}
2946 	/*
2947 	 * This code uses linux/include/scsi/scsi.h SAM status codes!
2948 	 */
2949 	cmd->scsi_status = SAM_STAT_CHECK_CONDITION;
2950 	/*
2951 	 * Automatically padded, this value is encoded in the fabric's
2952 	 * data_length response PDU containing the SCSI defined sense data.
2953 	 */
2954 	cmd->scsi_sense_length  = TRANSPORT_SENSE_BUFFER;
2955 
2956 after_reason:
2957 	trace_target_cmd_complete(cmd);
2958 	return cmd->se_tfo->queue_status(cmd);
2959 }
2960 EXPORT_SYMBOL(transport_send_check_condition_and_sense);
2961 
2962 int transport_check_aborted_status(struct se_cmd *cmd, int send_status)
2963 {
2964 	if (!(cmd->transport_state & CMD_T_ABORTED))
2965 		return 0;
2966 
2967 	/*
2968 	 * If cmd has been aborted but either no status is to be sent or it has
2969 	 * already been sent, just return
2970 	 */
2971 	if (!send_status || !(cmd->se_cmd_flags & SCF_SEND_DELAYED_TAS))
2972 		return 1;
2973 
2974 	pr_debug("Sending delayed SAM_STAT_TASK_ABORTED status for CDB: 0x%02x ITT: 0x%08x\n",
2975 		 cmd->t_task_cdb[0], cmd->se_tfo->get_task_tag(cmd));
2976 
2977 	cmd->se_cmd_flags &= ~SCF_SEND_DELAYED_TAS;
2978 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
2979 	trace_target_cmd_complete(cmd);
2980 	cmd->se_tfo->queue_status(cmd);
2981 
2982 	return 1;
2983 }
2984 EXPORT_SYMBOL(transport_check_aborted_status);
2985 
2986 void transport_send_task_abort(struct se_cmd *cmd)
2987 {
2988 	unsigned long flags;
2989 
2990 	spin_lock_irqsave(&cmd->t_state_lock, flags);
2991 	if (cmd->se_cmd_flags & (SCF_SENT_CHECK_CONDITION)) {
2992 		spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2993 		return;
2994 	}
2995 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
2996 
2997 	/*
2998 	 * If there are still expected incoming fabric WRITEs, we wait
2999 	 * until until they have completed before sending a TASK_ABORTED
3000 	 * response.  This response with TASK_ABORTED status will be
3001 	 * queued back to fabric module by transport_check_aborted_status().
3002 	 */
3003 	if (cmd->data_direction == DMA_TO_DEVICE) {
3004 		if (cmd->se_tfo->write_pending_status(cmd) != 0) {
3005 			cmd->transport_state |= CMD_T_ABORTED;
3006 			cmd->se_cmd_flags |= SCF_SEND_DELAYED_TAS;
3007 			return;
3008 		}
3009 	}
3010 	cmd->scsi_status = SAM_STAT_TASK_ABORTED;
3011 
3012 	transport_lun_remove_cmd(cmd);
3013 
3014 	pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x,"
3015 		" ITT: 0x%08x\n", cmd->t_task_cdb[0],
3016 		cmd->se_tfo->get_task_tag(cmd));
3017 
3018 	trace_target_cmd_complete(cmd);
3019 	cmd->se_tfo->queue_status(cmd);
3020 }
3021 
3022 static void target_tmr_work(struct work_struct *work)
3023 {
3024 	struct se_cmd *cmd = container_of(work, struct se_cmd, work);
3025 	struct se_device *dev = cmd->se_dev;
3026 	struct se_tmr_req *tmr = cmd->se_tmr_req;
3027 	int ret;
3028 
3029 	switch (tmr->function) {
3030 	case TMR_ABORT_TASK:
3031 		core_tmr_abort_task(dev, tmr, cmd->se_sess);
3032 		break;
3033 	case TMR_ABORT_TASK_SET:
3034 	case TMR_CLEAR_ACA:
3035 	case TMR_CLEAR_TASK_SET:
3036 		tmr->response = TMR_TASK_MGMT_FUNCTION_NOT_SUPPORTED;
3037 		break;
3038 	case TMR_LUN_RESET:
3039 		ret = core_tmr_lun_reset(dev, tmr, NULL, NULL);
3040 		tmr->response = (!ret) ? TMR_FUNCTION_COMPLETE :
3041 					 TMR_FUNCTION_REJECTED;
3042 		break;
3043 	case TMR_TARGET_WARM_RESET:
3044 		tmr->response = TMR_FUNCTION_REJECTED;
3045 		break;
3046 	case TMR_TARGET_COLD_RESET:
3047 		tmr->response = TMR_FUNCTION_REJECTED;
3048 		break;
3049 	default:
3050 		pr_err("Uknown TMR function: 0x%02x.\n",
3051 				tmr->function);
3052 		tmr->response = TMR_FUNCTION_REJECTED;
3053 		break;
3054 	}
3055 
3056 	cmd->t_state = TRANSPORT_ISTATE_PROCESSING;
3057 	cmd->se_tfo->queue_tm_rsp(cmd);
3058 
3059 	transport_cmd_check_stop_to_fabric(cmd);
3060 }
3061 
3062 int transport_generic_handle_tmr(
3063 	struct se_cmd *cmd)
3064 {
3065 	unsigned long flags;
3066 
3067 	spin_lock_irqsave(&cmd->t_state_lock, flags);
3068 	cmd->transport_state |= CMD_T_ACTIVE;
3069 	spin_unlock_irqrestore(&cmd->t_state_lock, flags);
3070 
3071 	INIT_WORK(&cmd->work, target_tmr_work);
3072 	queue_work(cmd->se_dev->tmr_wq, &cmd->work);
3073 	return 0;
3074 }
3075 EXPORT_SYMBOL(transport_generic_handle_tmr);
3076